Context stringlengths 57 92.3k | file_name stringlengths 21 79 | start int64 14 3.67k | end int64 18 3.69k | theorem stringlengths 25 2.71k | proof stringlengths 5 10.6k |
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import Mathlib.Init.Function
#align_import data.option.n_ary from "leanprover-community/mathlib"@"995b47e555f1b6297c7cf16855f1023e355219fb"
universe u
open Function
namespace Option
variable {α β γ δ : Type*} {f : α → β → γ} {a : Option α} {b : Option β} {c : Option γ}
def map₂ (f : α → β → γ) (a : Option α) (b : Option β) : Option γ :=
a.bind fun a => b.map <| f a
#align option.map₂ Option.map₂
theorem map₂_def {α β γ : Type u} (f : α → β → γ) (a : Option α) (b : Option β) :
map₂ f a b = f <$> a <*> b := by
cases a <;> rfl
#align option.map₂_def Option.map₂_def
-- Porting note (#10618): In Lean3, was `@[simp]` but now `simp` can prove it
theorem map₂_some_some (f : α → β → γ) (a : α) (b : β) : map₂ f (some a) (some b) = f a b := rfl
#align option.map₂_some_some Option.map₂_some_some
theorem map₂_coe_coe (f : α → β → γ) (a : α) (b : β) : map₂ f a b = f a b := rfl
#align option.map₂_coe_coe Option.map₂_coe_coe
@[simp]
theorem map₂_none_left (f : α → β → γ) (b : Option β) : map₂ f none b = none := rfl
#align option.map₂_none_left Option.map₂_none_left
@[simp]
theorem map₂_none_right (f : α → β → γ) (a : Option α) : map₂ f a none = none := by cases a <;> rfl
#align option.map₂_none_right Option.map₂_none_right
@[simp]
theorem map₂_coe_left (f : α → β → γ) (a : α) (b : Option β) : map₂ f a b = b.map fun b => f a b :=
rfl
#align option.map₂_coe_left Option.map₂_coe_left
-- Porting note: This proof was `rfl` in Lean3, but now is not.
@[simp]
theorem map₂_coe_right (f : α → β → γ) (a : Option α) (b : β) :
map₂ f a b = a.map fun a => f a b := by cases a <;> rfl
#align option.map₂_coe_right Option.map₂_coe_right
-- Porting note: Removed the `@[simp]` tag as membership of an `Option` is no-longer simp-normal.
| Mathlib/Data/Option/NAry.lean | 78 | 79 | theorem mem_map₂_iff {c : γ} : c ∈ map₂ f a b ↔ ∃ a' b', a' ∈ a ∧ b' ∈ b ∧ f a' b' = c := by |
simp [map₂, bind_eq_some]
|
import Mathlib.Combinatorics.SimpleGraph.Coloring
#align_import combinatorics.simple_graph.partition from "leanprover-community/mathlib"@"2303b3e299f1c75b07bceaaac130ce23044d1386"
universe u v
namespace SimpleGraph
variable {V : Type u} (G : SimpleGraph V)
structure Partition where
parts : Set (Set V)
isPartition : Setoid.IsPartition parts
independent : ∀ s ∈ parts, IsAntichain G.Adj s
#align simple_graph.partition SimpleGraph.Partition
def Partition.PartsCardLe {G : SimpleGraph V} (P : G.Partition) (n : ℕ) : Prop :=
∃ h : P.parts.Finite, h.toFinset.card ≤ n
#align simple_graph.partition.parts_card_le SimpleGraph.Partition.PartsCardLe
def Partitionable (n : ℕ) : Prop := ∃ P : G.Partition, P.PartsCardLe n
#align simple_graph.partitionable SimpleGraph.Partitionable
variable {G}
@[simps]
def Coloring.toPartition {α : Type v} (C : G.Coloring α) : G.Partition where
parts := C.colorClasses
isPartition := C.colorClasses_isPartition
independent := by
rintro s ⟨c, rfl⟩
apply C.color_classes_independent
#align simple_graph.coloring.to_partition SimpleGraph.Coloring.toPartition
@[simps]
instance : Inhabited (Partition G) := ⟨G.selfColoring.toPartition⟩
| Mathlib/Combinatorics/SimpleGraph/Partition.lean | 140 | 152 | theorem partitionable_iff_colorable {n : ℕ} : G.Partitionable n ↔ G.Colorable n := by |
constructor
· rintro ⟨P, hf, hc⟩
have : Fintype P.parts := hf.fintype
rw [Set.Finite.card_toFinset hf] at hc
apply P.colorable.mono hc
· rintro ⟨C⟩
refine ⟨C.toPartition, C.colorClasses_finite, le_trans ?_ (Fintype.card_fin n).le⟩
generalize_proofs h
change Set.Finite (Coloring.colorClasses C) at h
have : Fintype C.colorClasses := C.colorClasses_finite.fintype
rw [h.card_toFinset]
exact C.card_colorClasses_le
|
import Mathlib.Algebra.Algebra.Pi
import Mathlib.Algebra.Polynomial.Eval
import Mathlib.RingTheory.Adjoin.Basic
#align_import data.polynomial.algebra_map from "leanprover-community/mathlib"@"e064a7bf82ad94c3c17b5128bbd860d1ec34874e"
noncomputable section
open Finset
open Polynomial
namespace Polynomial
universe u v w z
variable {R : Type u} {S : Type v} {T : Type w} {A : Type z} {A' B : Type*} {a b : R} {n : ℕ}
section CommSemiring
variable [CommSemiring R] [Semiring A] [Semiring B] [Algebra R A] [Algebra R B]
variable {p q r : R[X]}
instance algebraOfAlgebra : Algebra R A[X] where
smul_def' r p :=
toFinsupp_injective <| by
dsimp only [RingHom.toFun_eq_coe, RingHom.comp_apply]
rw [toFinsupp_smul, toFinsupp_mul, toFinsupp_C]
exact Algebra.smul_def' _ _
commutes' r p :=
toFinsupp_injective <| by
dsimp only [RingHom.toFun_eq_coe, RingHom.comp_apply]
simp_rw [toFinsupp_mul, toFinsupp_C]
convert Algebra.commutes' r p.toFinsupp
toRingHom := C.comp (algebraMap R A)
#align polynomial.algebra_of_algebra Polynomial.algebraOfAlgebra
@[simp]
theorem algebraMap_apply (r : R) : algebraMap R A[X] r = C (algebraMap R A r) :=
rfl
#align polynomial.algebra_map_apply Polynomial.algebraMap_apply
@[simp]
theorem toFinsupp_algebraMap (r : R) : (algebraMap R A[X] r).toFinsupp = algebraMap R _ r :=
show toFinsupp (C (algebraMap _ _ r)) = _ by
rw [toFinsupp_C]
rfl
#align polynomial.to_finsupp_algebra_map Polynomial.toFinsupp_algebraMap
theorem ofFinsupp_algebraMap (r : R) : (⟨algebraMap R _ r⟩ : A[X]) = algebraMap R A[X] r :=
toFinsupp_injective (toFinsupp_algebraMap _).symm
#align polynomial.of_finsupp_algebra_map Polynomial.ofFinsupp_algebraMap
theorem C_eq_algebraMap (r : R) : C r = algebraMap R R[X] r :=
rfl
set_option linter.uppercaseLean3 false in
#align polynomial.C_eq_algebra_map Polynomial.C_eq_algebraMap
@[simp]
theorem algebraMap_eq : algebraMap R R[X] = C :=
rfl
@[simps! apply]
def CAlgHom : A →ₐ[R] A[X] where
toRingHom := C
commutes' _ := rfl
@[ext 1100]
theorem algHom_ext' {f g : A[X] →ₐ[R] B}
(hC : f.comp CAlgHom = g.comp CAlgHom)
(hX : f X = g X) : f = g :=
AlgHom.coe_ringHom_injective (ringHom_ext' (congr_arg AlgHom.toRingHom hC) hX)
#align polynomial.alg_hom_ext' Polynomial.algHom_ext'
variable (R)
open AddMonoidAlgebra in
@[simps!]
def toFinsuppIsoAlg : R[X] ≃ₐ[R] R[ℕ] :=
{ toFinsuppIso R with
commutes' := fun r => by
dsimp }
#align polynomial.to_finsupp_iso_alg Polynomial.toFinsuppIsoAlg
variable {R}
instance subalgebraNontrivial [Nontrivial A] : Nontrivial (Subalgebra R A[X]) :=
⟨⟨⊥, ⊤, by
rw [Ne, SetLike.ext_iff, not_forall]
refine ⟨X, ?_⟩
simp only [Algebra.mem_bot, not_exists, Set.mem_range, iff_true_iff, Algebra.mem_top,
algebraMap_apply, not_forall]
intro x
rw [ext_iff, not_forall]
refine ⟨1, ?_⟩
simp [coeff_C]⟩⟩
@[simp]
| Mathlib/Algebra/Polynomial/AlgebraMap.lean | 123 | 127 | theorem algHom_eval₂_algebraMap {R A B : Type*} [CommSemiring R] [Semiring A] [Semiring B]
[Algebra R A] [Algebra R B] (p : R[X]) (f : A →ₐ[R] B) (a : A) :
f (eval₂ (algebraMap R A) a p) = eval₂ (algebraMap R B) (f a) p := by |
simp only [eval₂_eq_sum, sum_def]
simp only [f.map_sum, f.map_mul, f.map_pow, eq_intCast, map_intCast, AlgHom.commutes]
|
import Mathlib.MeasureTheory.Integral.IntegralEqImproper
#align_import measure_theory.integral.peak_function from "leanprover-community/mathlib"@"13b0d72fd8533ba459ac66e9a885e35ffabb32b2"
open Set Filter MeasureTheory MeasureTheory.Measure TopologicalSpace Metric
open scoped Topology ENNReal
open Set
variable {α E ι : Type*} {hm : MeasurableSpace α} {μ : Measure α} [TopologicalSpace α]
[BorelSpace α] [NormedAddCommGroup E] [NormedSpace ℝ E] {g : α → E} {l : Filter ι} {x₀ : α}
{s t : Set α} {φ : ι → α → ℝ} {a : E}
theorem integrableOn_peak_smul_of_integrableOn_of_tendsto
(hs : MeasurableSet s) (h'st : t ∈ 𝓝[s] x₀)
(hlφ : ∀ u : Set α, IsOpen u → x₀ ∈ u → TendstoUniformlyOn φ 0 l (s \ u))
(hiφ : Tendsto (fun i ↦ ∫ x in t, φ i x ∂μ) l (𝓝 1))
(h'iφ : ∀ᶠ i in l, AEStronglyMeasurable (φ i) (μ.restrict s))
(hmg : IntegrableOn g s μ) (hcg : Tendsto g (𝓝[s] x₀) (𝓝 a)) :
∀ᶠ i in l, IntegrableOn (fun x => φ i x • g x) s μ := by
obtain ⟨u, u_open, x₀u, ut, hu⟩ :
∃ u, IsOpen u ∧ x₀ ∈ u ∧ s ∩ u ⊆ t ∧ ∀ x ∈ u ∩ s, g x ∈ ball a 1 := by
rcases mem_nhdsWithin.1 (Filter.inter_mem h'st (hcg (ball_mem_nhds _ zero_lt_one)))
with ⟨u, u_open, x₀u, hu⟩
refine ⟨u, u_open, x₀u, ?_, hu.trans inter_subset_right⟩
rw [inter_comm]
exact hu.trans inter_subset_left
rw [tendsto_iff_norm_sub_tendsto_zero] at hiφ
filter_upwards [tendstoUniformlyOn_iff.1 (hlφ u u_open x₀u) 1 zero_lt_one,
(tendsto_order.1 hiφ).2 1 zero_lt_one, h'iφ] with i hi h'i h''i
have I : IntegrableOn (φ i) t μ := .of_integral_ne_zero (fun h ↦ by simp [h] at h'i)
have A : IntegrableOn (fun x => φ i x • g x) (s \ u) μ := by
refine Integrable.smul_of_top_right (hmg.mono diff_subset le_rfl) ?_
apply memℒp_top_of_bound (h''i.mono_set diff_subset) 1
filter_upwards [self_mem_ae_restrict (hs.diff u_open.measurableSet)] with x hx
simpa only [Pi.zero_apply, dist_zero_left] using (hi x hx).le
have B : IntegrableOn (fun x => φ i x • g x) (s ∩ u) μ := by
apply Integrable.smul_of_top_left
· exact IntegrableOn.mono_set I ut
· apply
memℒp_top_of_bound (hmg.mono_set inter_subset_left).aestronglyMeasurable (‖a‖ + 1)
filter_upwards [self_mem_ae_restrict (hs.inter u_open.measurableSet)] with x hx
rw [inter_comm] at hx
exact (norm_lt_of_mem_ball (hu x hx)).le
convert A.union B
simp only [diff_union_inter]
#align integrable_on_peak_smul_of_integrable_on_of_continuous_within_at integrableOn_peak_smul_of_integrableOn_of_tendsto
@[deprecated (since := "2024-02-20")]
alias integrableOn_peak_smul_of_integrableOn_of_continuousWithinAt :=
integrableOn_peak_smul_of_integrableOn_of_tendsto
variable [CompleteSpace E]
theorem tendsto_setIntegral_peak_smul_of_integrableOn_of_tendsto_aux
(hs : MeasurableSet s) (ht : MeasurableSet t) (hts : t ⊆ s) (h'ts : t ∈ 𝓝[s] x₀)
(hnφ : ∀ᶠ i in l, ∀ x ∈ s, 0 ≤ φ i x)
(hlφ : ∀ u : Set α, IsOpen u → x₀ ∈ u → TendstoUniformlyOn φ 0 l (s \ u))
(hiφ : Tendsto (fun i ↦ ∫ x in t, φ i x ∂μ) l (𝓝 1))
(h'iφ : ∀ᶠ i in l, AEStronglyMeasurable (φ i) (μ.restrict s))
(hmg : IntegrableOn g s μ) (hcg : Tendsto g (𝓝[s] x₀) (𝓝 0)) :
Tendsto (fun i : ι => ∫ x in s, φ i x • g x ∂μ) l (𝓝 0) := by
refine Metric.tendsto_nhds.2 fun ε εpos => ?_
obtain ⟨δ, hδ, δpos, δone⟩ : ∃ δ, (δ * ∫ x in s, ‖g x‖ ∂μ) + 2 * δ < ε ∧ 0 < δ ∧ δ < 1:= by
have A :
Tendsto (fun δ => (δ * ∫ x in s, ‖g x‖ ∂μ) + 2 * δ) (𝓝[>] 0)
(𝓝 ((0 * ∫ x in s, ‖g x‖ ∂μ) + 2 * 0)) := by
apply Tendsto.mono_left _ nhdsWithin_le_nhds
exact (tendsto_id.mul tendsto_const_nhds).add (tendsto_id.const_mul _)
rw [zero_mul, zero_add, mul_zero] at A
have : Ioo (0 : ℝ) 1 ∈ 𝓝[>] 0 := Ioo_mem_nhdsWithin_Ioi ⟨le_rfl, zero_lt_one⟩
rcases (((tendsto_order.1 A).2 ε εpos).and this).exists with ⟨δ, hδ, h'δ⟩
exact ⟨δ, hδ, h'δ.1, h'δ.2⟩
suffices ∀ᶠ i in l, ‖∫ x in s, φ i x • g x ∂μ‖ ≤ (δ * ∫ x in s, ‖g x‖ ∂μ) + 2 * δ by
filter_upwards [this] with i hi
simp only [dist_zero_right]
exact hi.trans_lt hδ
obtain ⟨u, u_open, x₀u, ut, hu⟩ :
∃ u, IsOpen u ∧ x₀ ∈ u ∧ s ∩ u ⊆ t ∧ ∀ x ∈ u ∩ s, g x ∈ ball 0 δ := by
rcases mem_nhdsWithin.1 (Filter.inter_mem h'ts (hcg (ball_mem_nhds _ δpos)))
with ⟨u, u_open, x₀u, hu⟩
refine ⟨u, u_open, x₀u, ?_, hu.trans inter_subset_right⟩
rw [inter_comm]
exact hu.trans inter_subset_left
filter_upwards [tendstoUniformlyOn_iff.1 (hlφ u u_open x₀u) δ δpos,
(tendsto_order.1 (tendsto_iff_norm_sub_tendsto_zero.1 hiφ)).2 δ δpos, hnφ,
integrableOn_peak_smul_of_integrableOn_of_tendsto hs h'ts hlφ hiφ h'iφ hmg hcg]
with i hi h'i hφpos h''i
have I : IntegrableOn (φ i) t μ := by
apply Integrable.of_integral_ne_zero (fun h ↦ ?_)
simp [h] at h'i
linarith
have B : ‖∫ x in s ∩ u, φ i x • g x ∂μ‖ ≤ 2 * δ :=
calc
‖∫ x in s ∩ u, φ i x • g x ∂μ‖ ≤ ∫ x in s ∩ u, ‖φ i x • g x‖ ∂μ :=
norm_integral_le_integral_norm _
_ ≤ ∫ x in s ∩ u, ‖φ i x‖ * δ ∂μ := by
refine setIntegral_mono_on ?_ ?_ (hs.inter u_open.measurableSet) fun x hx => ?_
· exact IntegrableOn.mono_set h''i.norm inter_subset_left
· exact IntegrableOn.mono_set (I.norm.mul_const _) ut
rw [norm_smul]
apply mul_le_mul_of_nonneg_left _ (norm_nonneg _)
rw [inter_comm] at hu
exact (mem_ball_zero_iff.1 (hu x hx)).le
_ ≤ ∫ x in t, ‖φ i x‖ * δ ∂μ := by
apply setIntegral_mono_set
· exact I.norm.mul_const _
· exact eventually_of_forall fun x => mul_nonneg (norm_nonneg _) δpos.le
· exact eventually_of_forall ut
_ = ∫ x in t, φ i x * δ ∂μ := by
apply setIntegral_congr ht fun x hx => ?_
rw [Real.norm_of_nonneg (hφpos _ (hts hx))]
_ = (∫ x in t, φ i x ∂μ) * δ := by rw [integral_mul_right]
_ ≤ 2 * δ := by gcongr; linarith [(le_abs_self _).trans h'i.le]
have C : ‖∫ x in s \ u, φ i x • g x ∂μ‖ ≤ δ * ∫ x in s, ‖g x‖ ∂μ :=
calc
‖∫ x in s \ u, φ i x • g x ∂μ‖ ≤ ∫ x in s \ u, ‖φ i x • g x‖ ∂μ :=
norm_integral_le_integral_norm _
_ ≤ ∫ x in s \ u, δ * ‖g x‖ ∂μ := by
refine setIntegral_mono_on ?_ ?_ (hs.diff u_open.measurableSet) fun x hx => ?_
· exact IntegrableOn.mono_set h''i.norm diff_subset
· exact IntegrableOn.mono_set (hmg.norm.const_mul _) diff_subset
rw [norm_smul]
apply mul_le_mul_of_nonneg_right _ (norm_nonneg _)
simpa only [Pi.zero_apply, dist_zero_left] using (hi x hx).le
_ ≤ δ * ∫ x in s, ‖g x‖ ∂μ := by
rw [integral_mul_left]
apply mul_le_mul_of_nonneg_left (setIntegral_mono_set hmg.norm _ _) δpos.le
· filter_upwards with x using norm_nonneg _
· filter_upwards using diff_subset (s := s) (t := u)
calc
‖∫ x in s, φ i x • g x ∂μ‖ =
‖(∫ x in s \ u, φ i x • g x ∂μ) + ∫ x in s ∩ u, φ i x • g x ∂μ‖ := by
conv_lhs => rw [← diff_union_inter s u]
rw [integral_union disjoint_sdiff_inter (hs.inter u_open.measurableSet)
(h''i.mono_set diff_subset) (h''i.mono_set inter_subset_left)]
_ ≤ ‖∫ x in s \ u, φ i x • g x ∂μ‖ + ‖∫ x in s ∩ u, φ i x • g x ∂μ‖ := norm_add_le _ _
_ ≤ (δ * ∫ x in s, ‖g x‖ ∂μ) + 2 * δ := add_le_add C B
#align tendsto_set_integral_peak_smul_of_integrable_on_of_continuous_within_at_aux tendsto_setIntegral_peak_smul_of_integrableOn_of_tendsto_aux
@[deprecated (since := "2024-02-20")]
alias tendsto_setIntegral_peak_smul_of_integrableOn_of_continuousWithinAt_aux :=
tendsto_setIntegral_peak_smul_of_integrableOn_of_tendsto_aux
theorem tendsto_setIntegral_peak_smul_of_integrableOn_of_tendsto
(hs : MeasurableSet s) {t : Set α} (ht : MeasurableSet t) (hts : t ⊆ s) (h'ts : t ∈ 𝓝[s] x₀)
(h't : μ t ≠ ∞) (hnφ : ∀ᶠ i in l, ∀ x ∈ s, 0 ≤ φ i x)
(hlφ : ∀ u : Set α, IsOpen u → x₀ ∈ u → TendstoUniformlyOn φ 0 l (s \ u))
(hiφ : Tendsto (fun i ↦ ∫ x in t, φ i x ∂μ) l (𝓝 1))
(h'iφ : ∀ᶠ i in l, AEStronglyMeasurable (φ i) (μ.restrict s))
(hmg : IntegrableOn g s μ) (hcg : Tendsto g (𝓝[s] x₀) (𝓝 a)) :
Tendsto (fun i : ι ↦ ∫ x in s, φ i x • g x ∂μ) l (𝓝 a) := by
let h := g - t.indicator (fun _ ↦ a)
have A : Tendsto (fun i : ι => (∫ x in s, φ i x • h x ∂μ) + (∫ x in t, φ i x ∂μ) • a) l
(𝓝 (0 + (1 : ℝ) • a)) := by
refine Tendsto.add ?_ (Tendsto.smul hiφ tendsto_const_nhds)
apply tendsto_setIntegral_peak_smul_of_integrableOn_of_tendsto_aux hs ht hts h'ts
hnφ hlφ hiφ h'iφ
· apply hmg.sub
simp only [integrable_indicator_iff ht, integrableOn_const, ht, Measure.restrict_apply]
right
exact lt_of_le_of_lt (measure_mono inter_subset_left) (h't.lt_top)
· rw [← sub_self a]
apply Tendsto.sub hcg
apply tendsto_const_nhds.congr'
filter_upwards [h'ts] with x hx using by simp [hx]
simp only [one_smul, zero_add] at A
refine Tendsto.congr' ?_ A
filter_upwards [integrableOn_peak_smul_of_integrableOn_of_tendsto hs h'ts
hlφ hiφ h'iφ hmg hcg,
(tendsto_order.1 (tendsto_iff_norm_sub_tendsto_zero.1 hiφ)).2 1 zero_lt_one] with i hi h'i
simp only [h, Pi.sub_apply, smul_sub, ← indicator_smul_apply]
rw [integral_sub hi, setIntegral_indicator ht, inter_eq_right.mpr hts,
integral_smul_const, sub_add_cancel]
rw [integrable_indicator_iff ht]
apply Integrable.smul_const
rw [restrict_restrict ht, inter_eq_left.mpr hts]
exact .of_integral_ne_zero (fun h ↦ by simp [h] at h'i)
#align tendsto_set_integral_peak_smul_of_integrable_on_of_continuous_within_at tendsto_setIntegral_peak_smul_of_integrableOn_of_tendsto
@[deprecated (since := "2024-02-20")]
alias tendsto_setIntegral_peak_smul_of_integrableOn_of_continuousWithinAt :=
tendsto_setIntegral_peak_smul_of_integrableOn_of_tendsto
theorem tendsto_integral_peak_smul_of_integrable_of_tendsto
{t : Set α} (ht : MeasurableSet t) (h'ts : t ∈ 𝓝 x₀)
(h't : μ t ≠ ∞) (hnφ : ∀ᶠ i in l, ∀ x, 0 ≤ φ i x)
(hlφ : ∀ u : Set α, IsOpen u → x₀ ∈ u → TendstoUniformlyOn φ 0 l uᶜ)
(hiφ : Tendsto (fun i ↦ ∫ x in t, φ i x ∂μ) l (𝓝 1))
(h'iφ : ∀ᶠ i in l, AEStronglyMeasurable (φ i) μ)
(hmg : Integrable g μ) (hcg : Tendsto g (𝓝 x₀) (𝓝 a)) :
Tendsto (fun i : ι ↦ ∫ x, φ i x • g x ∂μ) l (𝓝 a) := by
suffices Tendsto (fun i : ι ↦ ∫ x in univ, φ i x • g x ∂μ) l (𝓝 a) by simpa
exact tendsto_setIntegral_peak_smul_of_integrableOn_of_tendsto MeasurableSet.univ ht (x₀ := x₀)
(subset_univ _) (by simpa [nhdsWithin_univ]) h't (by simpa)
(by simpa [← compl_eq_univ_diff] using hlφ) hiφ
(by simpa) (by simpa) (by simpa [nhdsWithin_univ])
theorem tendsto_setIntegral_pow_smul_of_unique_maximum_of_isCompact_of_measure_nhdsWithin_pos
[MetrizableSpace α] [IsLocallyFiniteMeasure μ] (hs : IsCompact s)
(hμ : ∀ u, IsOpen u → x₀ ∈ u → 0 < μ (u ∩ s)) {c : α → ℝ} (hc : ContinuousOn c s)
(h'c : ∀ y ∈ s, y ≠ x₀ → c y < c x₀) (hnc : ∀ x ∈ s, 0 ≤ c x) (hnc₀ : 0 < c x₀) (h₀ : x₀ ∈ s)
(hmg : IntegrableOn g s μ) (hcg : ContinuousWithinAt g s x₀) :
Tendsto (fun n : ℕ => (∫ x in s, c x ^ n ∂μ)⁻¹ • ∫ x in s, c x ^ n • g x ∂μ)
atTop (𝓝 (g x₀)) := by
let φ : ℕ → α → ℝ := fun n x => (∫ x in s, c x ^ n ∂μ)⁻¹ * c x ^ n
have hnφ : ∀ n, ∀ x ∈ s, 0 ≤ φ n x := by
intro n x hx
apply mul_nonneg (inv_nonneg.2 _) (pow_nonneg (hnc x hx) _)
exact setIntegral_nonneg hs.measurableSet fun x hx => pow_nonneg (hnc x hx) _
have I : ∀ n, IntegrableOn (fun x => c x ^ n) s μ := fun n =>
ContinuousOn.integrableOn_compact hs (hc.pow n)
have J : ∀ n, 0 ≤ᵐ[μ.restrict s] fun x : α => c x ^ n := by
intro n
filter_upwards [ae_restrict_mem hs.measurableSet] with x hx
exact pow_nonneg (hnc x hx) n
have P : ∀ n, (0 : ℝ) < ∫ x in s, c x ^ n ∂μ := by
intro n
refine (setIntegral_pos_iff_support_of_nonneg_ae (J n) (I n)).2 ?_
obtain ⟨u, u_open, x₀_u, hu⟩ : ∃ u : Set α, IsOpen u ∧ x₀ ∈ u ∧ u ∩ s ⊆ c ⁻¹' Ioi 0 :=
_root_.continuousOn_iff.1 hc x₀ h₀ (Ioi (0 : ℝ)) isOpen_Ioi hnc₀
apply (hμ u u_open x₀_u).trans_le
exact measure_mono fun x hx => ⟨ne_of_gt (pow_pos (a := c x) (hu hx) _), hx.2⟩
have hiφ : ∀ n, ∫ x in s, φ n x ∂μ = 1 := fun n => by
rw [integral_mul_left, inv_mul_cancel (P n).ne']
have A : ∀ u : Set α, IsOpen u → x₀ ∈ u → TendstoUniformlyOn φ 0 atTop (s \ u) := by
intro u u_open x₀u
obtain ⟨t, t_pos, tx₀, ht⟩ : ∃ t, 0 ≤ t ∧ t < c x₀ ∧ ∀ x ∈ s \ u, c x ≤ t := by
rcases eq_empty_or_nonempty (s \ u) with (h | h)
· exact
⟨0, le_rfl, hnc₀, by simp only [h, mem_empty_iff_false, IsEmpty.forall_iff, imp_true_iff]⟩
obtain ⟨x, hx, h'x⟩ : ∃ x ∈ s \ u, ∀ y ∈ s \ u, c y ≤ c x :=
IsCompact.exists_isMaxOn (hs.diff u_open) h (hc.mono diff_subset)
refine ⟨c x, hnc x hx.1, h'c x hx.1 ?_, h'x⟩
rintro rfl
exact hx.2 x₀u
obtain ⟨t', tt', t'x₀⟩ : ∃ t', t < t' ∧ t' < c x₀ := exists_between tx₀
have t'_pos : 0 < t' := t_pos.trans_lt tt'
obtain ⟨v, v_open, x₀_v, hv⟩ : ∃ v : Set α, IsOpen v ∧ x₀ ∈ v ∧ v ∩ s ⊆ c ⁻¹' Ioi t' :=
_root_.continuousOn_iff.1 hc x₀ h₀ (Ioi t') isOpen_Ioi t'x₀
have M : ∀ n, ∀ x ∈ s \ u, φ n x ≤ (μ (v ∩ s)).toReal⁻¹ * (t / t') ^ n := by
intro n x hx
have B : t' ^ n * (μ (v ∩ s)).toReal ≤ ∫ y in s, c y ^ n ∂μ :=
calc
t' ^ n * (μ (v ∩ s)).toReal = ∫ _ in v ∩ s, t' ^ n ∂μ := by
simp only [integral_const, Measure.restrict_apply, MeasurableSet.univ, univ_inter,
Algebra.id.smul_eq_mul, mul_comm]
_ ≤ ∫ y in v ∩ s, c y ^ n ∂μ := by
apply setIntegral_mono_on _ _ (v_open.measurableSet.inter hs.measurableSet) _
· apply integrableOn_const.2 (Or.inr _)
exact lt_of_le_of_lt (measure_mono inter_subset_right) hs.measure_lt_top
· exact (I n).mono inter_subset_right le_rfl
· intro x hx
exact pow_le_pow_left t'_pos.le (le_of_lt (hv hx)) _
_ ≤ ∫ y in s, c y ^ n ∂μ :=
setIntegral_mono_set (I n) (J n) (eventually_of_forall inter_subset_right)
simp_rw [φ, ← div_eq_inv_mul, div_pow, div_div]
apply div_le_div (pow_nonneg t_pos n) _ _ B
· exact pow_le_pow_left (hnc _ hx.1) (ht x hx) _
· apply mul_pos (pow_pos (t_pos.trans_lt tt') _) (ENNReal.toReal_pos (hμ v v_open x₀_v).ne' _)
have : μ (v ∩ s) ≤ μ s := measure_mono inter_subset_right
exact ne_of_lt (lt_of_le_of_lt this hs.measure_lt_top)
have N :
Tendsto (fun n => (μ (v ∩ s)).toReal⁻¹ * (t / t') ^ n) atTop
(𝓝 ((μ (v ∩ s)).toReal⁻¹ * 0)) := by
apply Tendsto.mul tendsto_const_nhds _
apply tendsto_pow_atTop_nhds_zero_of_lt_one (div_nonneg t_pos t'_pos.le)
exact (div_lt_one t'_pos).2 tt'
rw [mul_zero] at N
refine tendstoUniformlyOn_iff.2 fun ε εpos => ?_
filter_upwards [(tendsto_order.1 N).2 ε εpos] with n hn x hx
simp only [Pi.zero_apply, dist_zero_left, Real.norm_of_nonneg (hnφ n x hx.1)]
exact (M n x hx).trans_lt hn
have : Tendsto (fun i : ℕ => ∫ x : α in s, φ i x • g x ∂μ) atTop (𝓝 (g x₀)) := by
have B : Tendsto (fun i ↦ ∫ (x : α) in s, φ i x ∂μ) atTop (𝓝 1) :=
tendsto_const_nhds.congr (fun n ↦ (hiφ n).symm)
have C : ∀ᶠ (i : ℕ) in atTop, AEStronglyMeasurable (fun x ↦ φ i x) (μ.restrict s) := by
apply eventually_of_forall (fun n ↦ ((I n).const_mul _).aestronglyMeasurable)
exact tendsto_setIntegral_peak_smul_of_integrableOn_of_tendsto hs.measurableSet
hs.measurableSet (Subset.rfl) (self_mem_nhdsWithin)
hs.measure_lt_top.ne (eventually_of_forall hnφ) A B C hmg hcg
convert this
simp_rw [φ, ← smul_smul, integral_smul]
#align tendsto_set_integral_pow_smul_of_unique_maximum_of_is_compact_of_measure_nhds_within_pos tendsto_setIntegral_pow_smul_of_unique_maximum_of_isCompact_of_measure_nhdsWithin_pos
theorem tendsto_setIntegral_pow_smul_of_unique_maximum_of_isCompact_of_integrableOn
[MetrizableSpace α] [IsLocallyFiniteMeasure μ] [IsOpenPosMeasure μ] (hs : IsCompact s)
{c : α → ℝ} (hc : ContinuousOn c s) (h'c : ∀ y ∈ s, y ≠ x₀ → c y < c x₀)
(hnc : ∀ x ∈ s, 0 ≤ c x) (hnc₀ : 0 < c x₀) (h₀ : x₀ ∈ closure (interior s))
(hmg : IntegrableOn g s μ) (hcg : ContinuousWithinAt g s x₀) :
Tendsto (fun n : ℕ => (∫ x in s, c x ^ n ∂μ)⁻¹ • ∫ x in s, c x ^ n • g x ∂μ) atTop
(𝓝 (g x₀)) := by
have : x₀ ∈ s := by rw [← hs.isClosed.closure_eq]; exact closure_mono interior_subset h₀
apply
tendsto_setIntegral_pow_smul_of_unique_maximum_of_isCompact_of_measure_nhdsWithin_pos hs _ hc
h'c hnc hnc₀ this hmg hcg
intro u u_open x₀_u
calc
0 < μ (u ∩ interior s) :=
(u_open.inter isOpen_interior).measure_pos μ (_root_.mem_closure_iff.1 h₀ u u_open x₀_u)
_ ≤ μ (u ∩ s) := by gcongr; apply interior_subset
#align tendsto_set_integral_pow_smul_of_unique_maximum_of_is_compact_of_integrable_on tendsto_setIntegral_pow_smul_of_unique_maximum_of_isCompact_of_integrableOn
| Mathlib/MeasureTheory/Integral/PeakFunction.lean | 388 | 396 | theorem tendsto_setIntegral_pow_smul_of_unique_maximum_of_isCompact_of_continuousOn
[MetrizableSpace α] [IsLocallyFiniteMeasure μ] [IsOpenPosMeasure μ] (hs : IsCompact s)
{c : α → ℝ} (hc : ContinuousOn c s) (h'c : ∀ y ∈ s, y ≠ x₀ → c y < c x₀)
(hnc : ∀ x ∈ s, 0 ≤ c x) (hnc₀ : 0 < c x₀) (h₀ : x₀ ∈ closure (interior s))
(hmg : ContinuousOn g s) :
Tendsto (fun n : ℕ => (∫ x in s, c x ^ n ∂μ)⁻¹ • ∫ x in s, c x ^ n • g x ∂μ) atTop (𝓝 (g x₀)) :=
haveI : x₀ ∈ s := by | rw [← hs.isClosed.closure_eq]; exact closure_mono interior_subset h₀
tendsto_setIntegral_pow_smul_of_unique_maximum_of_isCompact_of_integrableOn hs hc h'c hnc hnc₀ h₀
(hmg.integrableOn_compact hs) (hmg x₀ this)
|
import Mathlib.Data.Set.Function
import Mathlib.Order.Interval.Set.OrdConnected
#align_import data.set.intervals.proj_Icc from "leanprover-community/mathlib"@"4e24c4bfcff371c71f7ba22050308aa17815626c"
variable {α β : Type*} [LinearOrder α]
open Function
namespace Set
def projIci (a x : α) : Ici a := ⟨max a x, le_max_left _ _⟩
#align set.proj_Ici Set.projIci
def projIic (b x : α) : Iic b := ⟨min b x, min_le_left _ _⟩
#align set.proj_Iic Set.projIic
def projIcc (a b : α) (h : a ≤ b) (x : α) : Icc a b :=
⟨max a (min b x), le_max_left _ _, max_le h (min_le_left _ _)⟩
#align set.proj_Icc Set.projIcc
variable {a b : α} (h : a ≤ b) {x : α}
@[norm_cast]
theorem coe_projIci (a x : α) : (projIci a x : α) = max a x := rfl
#align set.coe_proj_Ici Set.coe_projIci
@[norm_cast]
theorem coe_projIic (b x : α) : (projIic b x : α) = min b x := rfl
#align set.coe_proj_Iic Set.coe_projIic
@[norm_cast]
theorem coe_projIcc (a b : α) (h : a ≤ b) (x : α) : (projIcc a b h x : α) = max a (min b x) := rfl
#align set.coe_proj_Icc Set.coe_projIcc
theorem projIci_of_le (hx : x ≤ a) : projIci a x = ⟨a, le_rfl⟩ := Subtype.ext <| max_eq_left hx
#align set.proj_Ici_of_le Set.projIci_of_le
theorem projIic_of_le (hx : b ≤ x) : projIic b x = ⟨b, le_rfl⟩ := Subtype.ext <| min_eq_left hx
#align set.proj_Iic_of_le Set.projIic_of_le
theorem projIcc_of_le_left (hx : x ≤ a) : projIcc a b h x = ⟨a, left_mem_Icc.2 h⟩ := by
simp [projIcc, hx, hx.trans h]
#align set.proj_Icc_of_le_left Set.projIcc_of_le_left
theorem projIcc_of_right_le (hx : b ≤ x) : projIcc a b h x = ⟨b, right_mem_Icc.2 h⟩ := by
simp [projIcc, hx, h]
#align set.proj_Icc_of_right_le Set.projIcc_of_right_le
@[simp]
theorem projIci_self (a : α) : projIci a a = ⟨a, le_rfl⟩ := projIci_of_le le_rfl
#align set.proj_Ici_self Set.projIci_self
@[simp]
theorem projIic_self (b : α) : projIic b b = ⟨b, le_rfl⟩ := projIic_of_le le_rfl
#align set.proj_Iic_self Set.projIic_self
@[simp]
theorem projIcc_left : projIcc a b h a = ⟨a, left_mem_Icc.2 h⟩ :=
projIcc_of_le_left h le_rfl
#align set.proj_Icc_left Set.projIcc_left
@[simp]
theorem projIcc_right : projIcc a b h b = ⟨b, right_mem_Icc.2 h⟩ :=
projIcc_of_right_le h le_rfl
#align set.proj_Icc_right Set.projIcc_right
theorem projIci_eq_self : projIci a x = ⟨a, le_rfl⟩ ↔ x ≤ a := by simp [projIci, Subtype.ext_iff]
#align set.proj_Ici_eq_self Set.projIci_eq_self
theorem projIic_eq_self : projIic b x = ⟨b, le_rfl⟩ ↔ b ≤ x := by simp [projIic, Subtype.ext_iff]
#align set.proj_Iic_eq_self Set.projIic_eq_self
theorem projIcc_eq_left (h : a < b) : projIcc a b h.le x = ⟨a, left_mem_Icc.mpr h.le⟩ ↔ x ≤ a := by
simp [projIcc, Subtype.ext_iff, h.not_le]
#align set.proj_Icc_eq_left Set.projIcc_eq_left
theorem projIcc_eq_right (h : a < b) : projIcc a b h.le x = ⟨b, right_mem_Icc.2 h.le⟩ ↔ b ≤ x := by
simp [projIcc, Subtype.ext_iff, max_min_distrib_left, h.le, h.not_le]
#align set.proj_Icc_eq_right Set.projIcc_eq_right
theorem projIci_of_mem (hx : x ∈ Ici a) : projIci a x = ⟨x, hx⟩ := by simpa [projIci]
#align set.proj_Ici_of_mem Set.projIci_of_mem
theorem projIic_of_mem (hx : x ∈ Iic b) : projIic b x = ⟨x, hx⟩ := by simpa [projIic]
#align set.proj_Iic_of_mem Set.projIic_of_mem
| Mathlib/Order/Interval/Set/ProjIcc.lean | 119 | 120 | theorem projIcc_of_mem (hx : x ∈ Icc a b) : projIcc a b h x = ⟨x, hx⟩ := by |
simp [projIcc, hx.1, hx.2]
|
import Mathlib.Algebra.Ring.InjSurj
import Mathlib.Algebra.Group.Units.Hom
import Mathlib.Algebra.Ring.Hom.Defs
#align_import algebra.ring.units from "leanprover-community/mathlib"@"2ed7e4aec72395b6a7c3ac4ac7873a7a43ead17c"
universe u v w x
variable {α : Type u} {β : Type v} {γ : Type w} {R : Type x}
open Function
namespace Units
section Ring
variable [Ring α] {a b : α}
-- Needs to have higher simp priority than divp_add_divp. 1000 is the default priority.
@[field_simps 1010]
theorem divp_add_divp_same (a b : α) (u : αˣ) : a /ₚ u + b /ₚ u = (a + b) /ₚ u := by
simp only [divp, add_mul]
#align units.divp_add_divp_same Units.divp_add_divp_same
-- Needs to have higher simp priority than divp_sub_divp. 1000 is the default priority.
@[field_simps 1010]
theorem divp_sub_divp_same (a b : α) (u : αˣ) : a /ₚ u - b /ₚ u = (a - b) /ₚ u := by
rw [sub_eq_add_neg, sub_eq_add_neg, neg_divp, divp_add_divp_same]
#align units.divp_sub_divp_same Units.divp_sub_divp_same
@[field_simps]
theorem add_divp (a b : α) (u : αˣ) : a + b /ₚ u = (a * u + b) /ₚ u := by
simp only [divp, add_mul, Units.mul_inv_cancel_right]
#align units.add_divp Units.add_divp
@[field_simps]
theorem sub_divp (a b : α) (u : αˣ) : a - b /ₚ u = (a * u - b) /ₚ u := by
simp only [divp, sub_mul, Units.mul_inv_cancel_right]
#align units.sub_divp Units.sub_divp
@[field_simps]
| Mathlib/Algebra/Ring/Units.lean | 82 | 83 | theorem divp_add (a b : α) (u : αˣ) : a /ₚ u + b = (a + b * u) /ₚ u := by |
simp only [divp, add_mul, Units.mul_inv_cancel_right]
|
import Mathlib.Geometry.Euclidean.Sphere.Basic
import Mathlib.LinearAlgebra.AffineSpace.FiniteDimensional
import Mathlib.Tactic.DeriveFintype
#align_import geometry.euclidean.circumcenter from "leanprover-community/mathlib"@"2de9c37fa71dde2f1c6feff19876dd6a7b1519f0"
noncomputable section
open scoped Classical
open RealInnerProductSpace
namespace EuclideanGeometry
variable {V : Type*} {P : Type*} [NormedAddCommGroup V] [InnerProductSpace ℝ V] [MetricSpace P]
[NormedAddTorsor V P]
open AffineSubspace
theorem dist_eq_iff_dist_orthogonalProjection_eq {s : AffineSubspace ℝ P} [Nonempty s]
[HasOrthogonalProjection s.direction] {p1 p2 : P} (p3 : P) (hp1 : p1 ∈ s) (hp2 : p2 ∈ s) :
dist p1 p3 = dist p2 p3 ↔
dist p1 (orthogonalProjection s p3) = dist p2 (orthogonalProjection s p3) := by
rw [← mul_self_inj_of_nonneg dist_nonneg dist_nonneg, ←
mul_self_inj_of_nonneg dist_nonneg dist_nonneg,
dist_sq_eq_dist_orthogonalProjection_sq_add_dist_orthogonalProjection_sq p3 hp1,
dist_sq_eq_dist_orthogonalProjection_sq_add_dist_orthogonalProjection_sq p3 hp2]
simp
#align euclidean_geometry.dist_eq_iff_dist_orthogonal_projection_eq EuclideanGeometry.dist_eq_iff_dist_orthogonalProjection_eq
theorem dist_set_eq_iff_dist_orthogonalProjection_eq {s : AffineSubspace ℝ P} [Nonempty s]
[HasOrthogonalProjection s.direction] {ps : Set P} (hps : ps ⊆ s) (p : P) :
(Set.Pairwise ps fun p1 p2 => dist p1 p = dist p2 p) ↔
Set.Pairwise ps fun p1 p2 =>
dist p1 (orthogonalProjection s p) = dist p2 (orthogonalProjection s p) :=
⟨fun h _ hp1 _ hp2 hne =>
(dist_eq_iff_dist_orthogonalProjection_eq p (hps hp1) (hps hp2)).1 (h hp1 hp2 hne),
fun h _ hp1 _ hp2 hne =>
(dist_eq_iff_dist_orthogonalProjection_eq p (hps hp1) (hps hp2)).2 (h hp1 hp2 hne)⟩
#align euclidean_geometry.dist_set_eq_iff_dist_orthogonal_projection_eq EuclideanGeometry.dist_set_eq_iff_dist_orthogonalProjection_eq
theorem exists_dist_eq_iff_exists_dist_orthogonalProjection_eq {s : AffineSubspace ℝ P} [Nonempty s]
[HasOrthogonalProjection s.direction] {ps : Set P} (hps : ps ⊆ s) (p : P) :
(∃ r, ∀ p1 ∈ ps, dist p1 p = r) ↔ ∃ r, ∀ p1 ∈ ps, dist p1 ↑(orthogonalProjection s p) = r := by
have h := dist_set_eq_iff_dist_orthogonalProjection_eq hps p
simp_rw [Set.pairwise_eq_iff_exists_eq] at h
exact h
#align euclidean_geometry.exists_dist_eq_iff_exists_dist_orthogonal_projection_eq EuclideanGeometry.exists_dist_eq_iff_exists_dist_orthogonalProjection_eq
| Mathlib/Geometry/Euclidean/Circumcenter.lean | 91 | 179 | theorem existsUnique_dist_eq_of_insert {s : AffineSubspace ℝ P}
[HasOrthogonalProjection s.direction] {ps : Set P} (hnps : ps.Nonempty) {p : P} (hps : ps ⊆ s)
(hp : p ∉ s) (hu : ∃! cs : Sphere P, cs.center ∈ s ∧ ps ⊆ (cs : Set P)) :
∃! cs₂ : Sphere P,
cs₂.center ∈ affineSpan ℝ (insert p (s : Set P)) ∧ insert p ps ⊆ (cs₂ : Set P) := by |
haveI : Nonempty s := Set.Nonempty.to_subtype (hnps.mono hps)
rcases hu with ⟨⟨cc, cr⟩, ⟨hcc, hcr⟩, hcccru⟩
simp only at hcc hcr hcccru
let x := dist cc (orthogonalProjection s p)
let y := dist p (orthogonalProjection s p)
have hy0 : y ≠ 0 := dist_orthogonalProjection_ne_zero_of_not_mem hp
let ycc₂ := (x * x + y * y - cr * cr) / (2 * y)
let cc₂ := (ycc₂ / y) • (p -ᵥ orthogonalProjection s p : V) +ᵥ cc
let cr₂ := √(cr * cr + ycc₂ * ycc₂)
use ⟨cc₂, cr₂⟩
simp (config := { zeta := false, proj := false }) only
have hpo : p = (1 : ℝ) • (p -ᵥ orthogonalProjection s p : V) +ᵥ (orthogonalProjection s p : P) :=
by simp
constructor
· constructor
· refine vadd_mem_of_mem_direction ?_ (mem_affineSpan ℝ (Set.mem_insert_of_mem _ hcc))
rw [direction_affineSpan]
exact
Submodule.smul_mem _ _
(vsub_mem_vectorSpan ℝ (Set.mem_insert _ _)
(Set.mem_insert_of_mem _ (orthogonalProjection_mem _)))
· intro p1 hp1
rw [Sphere.mem_coe, mem_sphere, ← mul_self_inj_of_nonneg dist_nonneg (Real.sqrt_nonneg _),
Real.mul_self_sqrt (add_nonneg (mul_self_nonneg _) (mul_self_nonneg _))]
cases' hp1 with hp1 hp1
· rw [hp1]
rw [hpo,
dist_sq_smul_orthogonal_vadd_smul_orthogonal_vadd (orthogonalProjection_mem p) hcc _ _
(vsub_orthogonalProjection_mem_direction_orthogonal s p),
← dist_eq_norm_vsub V p, dist_comm _ cc]
field_simp [ycc₂, hy0]
ring
· rw [dist_sq_eq_dist_orthogonalProjection_sq_add_dist_orthogonalProjection_sq _ (hps hp1),
orthogonalProjection_vadd_smul_vsub_orthogonalProjection _ _ hcc, Subtype.coe_mk,
dist_of_mem_subset_mk_sphere hp1 hcr, dist_eq_norm_vsub V cc₂ cc, vadd_vsub, norm_smul, ←
dist_eq_norm_vsub V, Real.norm_eq_abs, abs_div, abs_of_nonneg dist_nonneg,
div_mul_cancel₀ _ hy0, abs_mul_abs_self]
· rintro ⟨cc₃, cr₃⟩ ⟨hcc₃, hcr₃⟩
simp only at hcc₃ hcr₃
obtain ⟨t₃, cc₃', hcc₃', hcc₃''⟩ :
∃ r : ℝ, ∃ p0 ∈ s, cc₃ = r • (p -ᵥ ↑((orthogonalProjection s) p)) +ᵥ p0 := by
rwa [mem_affineSpan_insert_iff (orthogonalProjection_mem p)] at hcc₃
have hcr₃' : ∃ r, ∀ p1 ∈ ps, dist p1 cc₃ = r :=
⟨cr₃, fun p1 hp1 => dist_of_mem_subset_mk_sphere (Set.mem_insert_of_mem _ hp1) hcr₃⟩
rw [exists_dist_eq_iff_exists_dist_orthogonalProjection_eq hps cc₃, hcc₃'',
orthogonalProjection_vadd_smul_vsub_orthogonalProjection _ _ hcc₃'] at hcr₃'
cases' hcr₃' with cr₃' hcr₃'
have hu := hcccru ⟨cc₃', cr₃'⟩
simp only at hu
replace hu := hu ⟨hcc₃', hcr₃'⟩
-- Porting note: was
-- cases' hu with hucc hucr
-- substs hucc hucr
cases' hu
have hcr₃val : cr₃ = √(cr * cr + t₃ * y * (t₃ * y)) := by
cases' hnps with p0 hp0
have h' : ↑(⟨cc, hcc₃'⟩ : s) = cc := rfl
rw [← dist_of_mem_subset_mk_sphere (Set.mem_insert_of_mem _ hp0) hcr₃, hcc₃'', ←
mul_self_inj_of_nonneg dist_nonneg (Real.sqrt_nonneg _),
Real.mul_self_sqrt (add_nonneg (mul_self_nonneg _) (mul_self_nonneg _)),
dist_sq_eq_dist_orthogonalProjection_sq_add_dist_orthogonalProjection_sq _ (hps hp0),
orthogonalProjection_vadd_smul_vsub_orthogonalProjection _ _ hcc₃', h',
dist_of_mem_subset_mk_sphere hp0 hcr, dist_eq_norm_vsub V _ cc, vadd_vsub, norm_smul, ←
dist_eq_norm_vsub V p, Real.norm_eq_abs, ← mul_assoc, mul_comm _ |t₃|, ← mul_assoc,
abs_mul_abs_self]
ring
replace hcr₃ := dist_of_mem_subset_mk_sphere (Set.mem_insert _ _) hcr₃
rw [hpo, hcc₃'', hcr₃val, ← mul_self_inj_of_nonneg dist_nonneg (Real.sqrt_nonneg _),
dist_sq_smul_orthogonal_vadd_smul_orthogonal_vadd (orthogonalProjection_mem p) hcc₃' _ _
(vsub_orthogonalProjection_mem_direction_orthogonal s p),
dist_comm, ← dist_eq_norm_vsub V p,
Real.mul_self_sqrt (add_nonneg (mul_self_nonneg _) (mul_self_nonneg _))] at hcr₃
change x * x + _ * (y * y) = _ at hcr₃
rw [show
x * x + (1 - t₃) * (1 - t₃) * (y * y) = x * x + y * y - 2 * y * (t₃ * y) + t₃ * y * (t₃ * y)
by ring,
add_left_inj] at hcr₃
have ht₃ : t₃ = ycc₂ / y := by field_simp [ycc₂, ← hcr₃, hy0]
subst ht₃
change cc₃ = cc₂ at hcc₃''
congr
rw [hcr₃val]
congr 2
field_simp [hy0]
|
import Mathlib.Topology.CompactOpen
import Mathlib.Topology.Sets.Closeds
open Function Set Filter TopologicalSpace
open scoped Topology
variable {X Y : Type*} [TopologicalSpace X] [TopologicalSpace Y] [CompactSpace Y]
| Mathlib/Topology/ClopenBox.lean | 36 | 44 | theorem TopologicalSpace.Clopens.exists_prod_subset (W : Clopens (X × Y)) {a : X × Y} (h : a ∈ W) :
∃ U : Clopens X, a.1 ∈ U ∧ ∃ V : Clopens Y, a.2 ∈ V ∧ U ×ˢ V ≤ W := by |
have hp : Continuous (fun y : Y ↦ (a.1, y)) := Continuous.Prod.mk _
let V : Set Y := {y | (a.1, y) ∈ W}
have hV : IsCompact V := (W.2.1.preimage hp).isCompact
let U : Set X := {x | MapsTo (Prod.mk x) V W}
have hUV : U ×ˢ V ⊆ W := fun ⟨_, _⟩ hw ↦ hw.1 hw.2
exact ⟨⟨U, (ContinuousMap.isClopen_setOf_mapsTo hV W.2).preimage
(ContinuousMap.id (X × Y)).curry.2⟩, by simp [U, V, MapsTo], ⟨V, W.2.preimage hp⟩, h, hUV⟩
|
import Mathlib.Combinatorics.SimpleGraph.Init
import Mathlib.Data.Rel
import Mathlib.Data.Set.Finite
import Mathlib.Data.Sym.Sym2
#align_import combinatorics.simple_graph.basic from "leanprover-community/mathlib"@"3365b20c2ffa7c35e47e5209b89ba9abdddf3ffe"
-- Porting note: using `aesop` for automation
-- Porting note: These attributes are needed to use `aesop` as a replacement for `obviously`
attribute [aesop norm unfold (rule_sets := [SimpleGraph])] Symmetric
attribute [aesop norm unfold (rule_sets := [SimpleGraph])] Irreflexive
-- Porting note: a thin wrapper around `aesop` for graph lemmas, modelled on `aesop_cat`
macro (name := aesop_graph) "aesop_graph" c:Aesop.tactic_clause* : tactic =>
`(tactic|
aesop $c*
(config := { introsTransparency? := some .default, terminal := true })
(rule_sets := [$(Lean.mkIdent `SimpleGraph):ident]))
macro (name := aesop_graph?) "aesop_graph?" c:Aesop.tactic_clause* : tactic =>
`(tactic|
aesop $c*
(config := { introsTransparency? := some .default, terminal := true })
(rule_sets := [$(Lean.mkIdent `SimpleGraph):ident]))
macro (name := aesop_graph_nonterminal) "aesop_graph_nonterminal" c:Aesop.tactic_clause* : tactic =>
`(tactic|
aesop $c*
(config := { introsTransparency? := some .default, warnOnNonterminal := false })
(rule_sets := [$(Lean.mkIdent `SimpleGraph):ident]))
open Finset Function
universe u v w
@[ext, aesop safe constructors (rule_sets := [SimpleGraph])]
structure SimpleGraph (V : Type u) where
Adj : V → V → Prop
symm : Symmetric Adj := by aesop_graph
loopless : Irreflexive Adj := by aesop_graph
#align simple_graph SimpleGraph
-- Porting note: changed `obviously` to `aesop` in the `structure`
initialize_simps_projections SimpleGraph (Adj → adj)
@[simps]
def SimpleGraph.mk' {V : Type u} :
{adj : V → V → Bool // (∀ x y, adj x y = adj y x) ∧ (∀ x, ¬ adj x x)} ↪ SimpleGraph V where
toFun x := ⟨fun v w ↦ x.1 v w, fun v w ↦ by simp [x.2.1], fun v ↦ by simp [x.2.2]⟩
inj' := by
rintro ⟨adj, _⟩ ⟨adj', _⟩
simp only [mk.injEq, Subtype.mk.injEq]
intro h
funext v w
simpa [Bool.coe_iff_coe] using congr_fun₂ h v w
instance {V : Type u} [Fintype V] [DecidableEq V] : Fintype (SimpleGraph V) where
elems := Finset.univ.map SimpleGraph.mk'
complete := by
classical
rintro ⟨Adj, hs, hi⟩
simp only [mem_map, mem_univ, true_and, Subtype.exists, Bool.not_eq_true]
refine ⟨fun v w ↦ Adj v w, ⟨?_, ?_⟩, ?_⟩
· simp [hs.iff]
· intro v; simp [hi v]
· ext
simp
def SimpleGraph.fromRel {V : Type u} (r : V → V → Prop) : SimpleGraph V where
Adj a b := a ≠ b ∧ (r a b ∨ r b a)
symm := fun _ _ ⟨hn, hr⟩ => ⟨hn.symm, hr.symm⟩
loopless := fun _ ⟨hn, _⟩ => hn rfl
#align simple_graph.from_rel SimpleGraph.fromRel
@[simp]
theorem SimpleGraph.fromRel_adj {V : Type u} (r : V → V → Prop) (v w : V) :
(SimpleGraph.fromRel r).Adj v w ↔ v ≠ w ∧ (r v w ∨ r w v) :=
Iff.rfl
#align simple_graph.from_rel_adj SimpleGraph.fromRel_adj
-- Porting note: attributes needed for `completeGraph`
attribute [aesop safe (rule_sets := [SimpleGraph])] Ne.symm
attribute [aesop safe (rule_sets := [SimpleGraph])] Ne.irrefl
def completeGraph (V : Type u) : SimpleGraph V where Adj := Ne
#align complete_graph completeGraph
def emptyGraph (V : Type u) : SimpleGraph V where Adj _ _ := False
#align empty_graph emptyGraph
@[simps]
def completeBipartiteGraph (V W : Type*) : SimpleGraph (Sum V W) where
Adj v w := v.isLeft ∧ w.isRight ∨ v.isRight ∧ w.isLeft
symm v w := by cases v <;> cases w <;> simp
loopless v := by cases v <;> simp
#align complete_bipartite_graph completeBipartiteGraph
namespace SimpleGraph
variable {ι : Sort*} {V : Type u} (G : SimpleGraph V) {a b c u v w : V} {e : Sym2 V}
@[simp]
protected theorem irrefl {v : V} : ¬G.Adj v v :=
G.loopless v
#align simple_graph.irrefl SimpleGraph.irrefl
theorem adj_comm (u v : V) : G.Adj u v ↔ G.Adj v u :=
⟨fun x => G.symm x, fun x => G.symm x⟩
#align simple_graph.adj_comm SimpleGraph.adj_comm
@[symm]
theorem adj_symm (h : G.Adj u v) : G.Adj v u :=
G.symm h
#align simple_graph.adj_symm SimpleGraph.adj_symm
theorem Adj.symm {G : SimpleGraph V} {u v : V} (h : G.Adj u v) : G.Adj v u :=
G.symm h
#align simple_graph.adj.symm SimpleGraph.Adj.symm
theorem ne_of_adj (h : G.Adj a b) : a ≠ b := by
rintro rfl
exact G.irrefl h
#align simple_graph.ne_of_adj SimpleGraph.ne_of_adj
protected theorem Adj.ne {G : SimpleGraph V} {a b : V} (h : G.Adj a b) : a ≠ b :=
G.ne_of_adj h
#align simple_graph.adj.ne SimpleGraph.Adj.ne
protected theorem Adj.ne' {G : SimpleGraph V} {a b : V} (h : G.Adj a b) : b ≠ a :=
h.ne.symm
#align simple_graph.adj.ne' SimpleGraph.Adj.ne'
theorem ne_of_adj_of_not_adj {v w x : V} (h : G.Adj v x) (hn : ¬G.Adj w x) : v ≠ w := fun h' =>
hn (h' ▸ h)
#align simple_graph.ne_of_adj_of_not_adj SimpleGraph.ne_of_adj_of_not_adj
theorem adj_injective : Injective (Adj : SimpleGraph V → V → V → Prop) :=
SimpleGraph.ext
#align simple_graph.adj_injective SimpleGraph.adj_injective
@[simp]
theorem adj_inj {G H : SimpleGraph V} : G.Adj = H.Adj ↔ G = H :=
adj_injective.eq_iff
#align simple_graph.adj_inj SimpleGraph.adj_inj
section Order
def IsSubgraph (x y : SimpleGraph V) : Prop :=
∀ ⦃v w : V⦄, x.Adj v w → y.Adj v w
#align simple_graph.is_subgraph SimpleGraph.IsSubgraph
instance : LE (SimpleGraph V) :=
⟨IsSubgraph⟩
@[simp]
theorem isSubgraph_eq_le : (IsSubgraph : SimpleGraph V → SimpleGraph V → Prop) = (· ≤ ·) :=
rfl
#align simple_graph.is_subgraph_eq_le SimpleGraph.isSubgraph_eq_le
instance : Sup (SimpleGraph V) where
sup x y :=
{ Adj := x.Adj ⊔ y.Adj
symm := fun v w h => by rwa [Pi.sup_apply, Pi.sup_apply, x.adj_comm, y.adj_comm] }
@[simp]
theorem sup_adj (x y : SimpleGraph V) (v w : V) : (x ⊔ y).Adj v w ↔ x.Adj v w ∨ y.Adj v w :=
Iff.rfl
#align simple_graph.sup_adj SimpleGraph.sup_adj
instance : Inf (SimpleGraph V) where
inf x y :=
{ Adj := x.Adj ⊓ y.Adj
symm := fun v w h => by rwa [Pi.inf_apply, Pi.inf_apply, x.adj_comm, y.adj_comm] }
@[simp]
theorem inf_adj (x y : SimpleGraph V) (v w : V) : (x ⊓ y).Adj v w ↔ x.Adj v w ∧ y.Adj v w :=
Iff.rfl
#align simple_graph.inf_adj SimpleGraph.inf_adj
instance hasCompl : HasCompl (SimpleGraph V) where
compl G :=
{ Adj := fun v w => v ≠ w ∧ ¬G.Adj v w
symm := fun v w ⟨hne, _⟩ => ⟨hne.symm, by rwa [adj_comm]⟩
loopless := fun v ⟨hne, _⟩ => (hne rfl).elim }
@[simp]
theorem compl_adj (G : SimpleGraph V) (v w : V) : Gᶜ.Adj v w ↔ v ≠ w ∧ ¬G.Adj v w :=
Iff.rfl
#align simple_graph.compl_adj SimpleGraph.compl_adj
instance sdiff : SDiff (SimpleGraph V) where
sdiff x y :=
{ Adj := x.Adj \ y.Adj
symm := fun v w h => by change x.Adj w v ∧ ¬y.Adj w v; rwa [x.adj_comm, y.adj_comm] }
@[simp]
theorem sdiff_adj (x y : SimpleGraph V) (v w : V) : (x \ y).Adj v w ↔ x.Adj v w ∧ ¬y.Adj v w :=
Iff.rfl
#align simple_graph.sdiff_adj SimpleGraph.sdiff_adj
instance supSet : SupSet (SimpleGraph V) where
sSup s :=
{ Adj := fun a b => ∃ G ∈ s, Adj G a b
symm := fun a b => Exists.imp fun _ => And.imp_right Adj.symm
loopless := by
rintro a ⟨G, _, ha⟩
exact ha.ne rfl }
instance infSet : InfSet (SimpleGraph V) where
sInf s :=
{ Adj := fun a b => (∀ ⦃G⦄, G ∈ s → Adj G a b) ∧ a ≠ b
symm := fun _ _ => And.imp (forall₂_imp fun _ _ => Adj.symm) Ne.symm
loopless := fun _ h => h.2 rfl }
@[simp]
theorem sSup_adj {s : Set (SimpleGraph V)} {a b : V} : (sSup s).Adj a b ↔ ∃ G ∈ s, Adj G a b :=
Iff.rfl
#align simple_graph.Sup_adj SimpleGraph.sSup_adj
@[simp]
theorem sInf_adj {s : Set (SimpleGraph V)} : (sInf s).Adj a b ↔ (∀ G ∈ s, Adj G a b) ∧ a ≠ b :=
Iff.rfl
#align simple_graph.Inf_adj SimpleGraph.sInf_adj
@[simp]
theorem iSup_adj {f : ι → SimpleGraph V} : (⨆ i, f i).Adj a b ↔ ∃ i, (f i).Adj a b := by simp [iSup]
#align simple_graph.supr_adj SimpleGraph.iSup_adj
@[simp]
theorem iInf_adj {f : ι → SimpleGraph V} : (⨅ i, f i).Adj a b ↔ (∀ i, (f i).Adj a b) ∧ a ≠ b := by
simp [iInf]
#align simple_graph.infi_adj SimpleGraph.iInf_adj
theorem sInf_adj_of_nonempty {s : Set (SimpleGraph V)} (hs : s.Nonempty) :
(sInf s).Adj a b ↔ ∀ G ∈ s, Adj G a b :=
sInf_adj.trans <|
and_iff_left_of_imp <| by
obtain ⟨G, hG⟩ := hs
exact fun h => (h _ hG).ne
#align simple_graph.Inf_adj_of_nonempty SimpleGraph.sInf_adj_of_nonempty
theorem iInf_adj_of_nonempty [Nonempty ι] {f : ι → SimpleGraph V} :
(⨅ i, f i).Adj a b ↔ ∀ i, (f i).Adj a b := by
rw [iInf, sInf_adj_of_nonempty (Set.range_nonempty _), Set.forall_mem_range]
#align simple_graph.infi_adj_of_nonempty SimpleGraph.iInf_adj_of_nonempty
instance distribLattice : DistribLattice (SimpleGraph V) :=
{ show DistribLattice (SimpleGraph V) from
adj_injective.distribLattice _ (fun _ _ => rfl) fun _ _ => rfl with
le := fun G H => ∀ ⦃a b⦄, G.Adj a b → H.Adj a b }
instance completeAtomicBooleanAlgebra : CompleteAtomicBooleanAlgebra (SimpleGraph V) :=
{ SimpleGraph.distribLattice with
le := (· ≤ ·)
sup := (· ⊔ ·)
inf := (· ⊓ ·)
compl := HasCompl.compl
sdiff := (· \ ·)
top := completeGraph V
bot := emptyGraph V
le_top := fun x v w h => x.ne_of_adj h
bot_le := fun x v w h => h.elim
sdiff_eq := fun x y => by
ext v w
refine ⟨fun h => ⟨h.1, ⟨?_, h.2⟩⟩, fun h => ⟨h.1, h.2.2⟩⟩
rintro rfl
exact x.irrefl h.1
inf_compl_le_bot := fun G v w h => False.elim <| h.2.2 h.1
top_le_sup_compl := fun G v w hvw => by
by_cases h : G.Adj v w
· exact Or.inl h
· exact Or.inr ⟨hvw, h⟩
sSup := sSup
le_sSup := fun s G hG a b hab => ⟨G, hG, hab⟩
sSup_le := fun s G hG a b => by
rintro ⟨H, hH, hab⟩
exact hG _ hH hab
sInf := sInf
sInf_le := fun s G hG a b hab => hab.1 hG
le_sInf := fun s G hG a b hab => ⟨fun H hH => hG _ hH hab, hab.ne⟩
iInf_iSup_eq := fun f => by ext; simp [Classical.skolem] }
@[simp]
theorem top_adj (v w : V) : (⊤ : SimpleGraph V).Adj v w ↔ v ≠ w :=
Iff.rfl
#align simple_graph.top_adj SimpleGraph.top_adj
@[simp]
theorem bot_adj (v w : V) : (⊥ : SimpleGraph V).Adj v w ↔ False :=
Iff.rfl
#align simple_graph.bot_adj SimpleGraph.bot_adj
@[simp]
theorem completeGraph_eq_top (V : Type u) : completeGraph V = ⊤ :=
rfl
#align simple_graph.complete_graph_eq_top SimpleGraph.completeGraph_eq_top
@[simp]
theorem emptyGraph_eq_bot (V : Type u) : emptyGraph V = ⊥ :=
rfl
#align simple_graph.empty_graph_eq_bot SimpleGraph.emptyGraph_eq_bot
@[simps]
instance (V : Type u) : Inhabited (SimpleGraph V) :=
⟨⊥⟩
instance [Subsingleton V] : Unique (SimpleGraph V) where
default := ⊥
uniq G := by ext a b; have := Subsingleton.elim a b; simp [this]
instance [Nontrivial V] : Nontrivial (SimpleGraph V) :=
⟨⟨⊥, ⊤, fun h ↦ not_subsingleton V ⟨by simpa only [← adj_inj, Function.funext_iff, bot_adj,
top_adj, ne_eq, eq_iff_iff, false_iff, not_not] using h⟩⟩⟩
def support : Set V :=
Rel.dom G.Adj
#align simple_graph.support SimpleGraph.support
theorem mem_support {v : V} : v ∈ G.support ↔ ∃ w, G.Adj v w :=
Iff.rfl
#align simple_graph.mem_support SimpleGraph.mem_support
theorem support_mono {G G' : SimpleGraph V} (h : G ≤ G') : G.support ⊆ G'.support :=
Rel.dom_mono h
#align simple_graph.support_mono SimpleGraph.support_mono
def neighborSet (v : V) : Set V := {w | G.Adj v w}
#align simple_graph.neighbor_set SimpleGraph.neighborSet
instance neighborSet.memDecidable (v : V) [DecidableRel G.Adj] :
DecidablePred (· ∈ G.neighborSet v) :=
inferInstanceAs <| DecidablePred (Adj G v)
#align simple_graph.neighbor_set.mem_decidable SimpleGraph.neighborSet.memDecidable
def incidenceSet (v : V) : Set (Sym2 V) :=
{ e ∈ G.edgeSet | v ∈ e }
#align simple_graph.incidence_set SimpleGraph.incidenceSet
theorem incidenceSet_subset (v : V) : G.incidenceSet v ⊆ G.edgeSet := fun _ h => h.1
#align simple_graph.incidence_set_subset SimpleGraph.incidenceSet_subset
theorem mk'_mem_incidenceSet_iff : s(b, c) ∈ G.incidenceSet a ↔ G.Adj b c ∧ (a = b ∨ a = c) :=
and_congr_right' Sym2.mem_iff
#align simple_graph.mk_mem_incidence_set_iff SimpleGraph.mk'_mem_incidenceSet_iff
theorem mk'_mem_incidenceSet_left_iff : s(a, b) ∈ G.incidenceSet a ↔ G.Adj a b :=
and_iff_left <| Sym2.mem_mk_left _ _
#align simple_graph.mk_mem_incidence_set_left_iff SimpleGraph.mk'_mem_incidenceSet_left_iff
theorem mk'_mem_incidenceSet_right_iff : s(a, b) ∈ G.incidenceSet b ↔ G.Adj a b :=
and_iff_left <| Sym2.mem_mk_right _ _
#align simple_graph.mk_mem_incidence_set_right_iff SimpleGraph.mk'_mem_incidenceSet_right_iff
theorem edge_mem_incidenceSet_iff {e : G.edgeSet} : ↑e ∈ G.incidenceSet a ↔ a ∈ (e : Sym2 V) :=
and_iff_right e.2
#align simple_graph.edge_mem_incidence_set_iff SimpleGraph.edge_mem_incidenceSet_iff
theorem incidenceSet_inter_incidenceSet_subset (h : a ≠ b) :
G.incidenceSet a ∩ G.incidenceSet b ⊆ {s(a, b)} := fun _e he =>
(Sym2.mem_and_mem_iff h).1 ⟨he.1.2, he.2.2⟩
#align simple_graph.incidence_set_inter_incidence_set_subset SimpleGraph.incidenceSet_inter_incidenceSet_subset
theorem incidenceSet_inter_incidenceSet_of_adj (h : G.Adj a b) :
G.incidenceSet a ∩ G.incidenceSet b = {s(a, b)} := by
refine (G.incidenceSet_inter_incidenceSet_subset <| h.ne).antisymm ?_
rintro _ (rfl : _ = s(a, b))
exact ⟨G.mk'_mem_incidenceSet_left_iff.2 h, G.mk'_mem_incidenceSet_right_iff.2 h⟩
#align simple_graph.incidence_set_inter_incidence_set_of_adj SimpleGraph.incidenceSet_inter_incidenceSet_of_adj
theorem adj_of_mem_incidenceSet (h : a ≠ b) (ha : e ∈ G.incidenceSet a)
(hb : e ∈ G.incidenceSet b) : G.Adj a b := by
rwa [← mk'_mem_incidenceSet_left_iff, ←
Set.mem_singleton_iff.1 <| G.incidenceSet_inter_incidenceSet_subset h ⟨ha, hb⟩]
#align simple_graph.adj_of_mem_incidence_set SimpleGraph.adj_of_mem_incidenceSet
theorem incidenceSet_inter_incidenceSet_of_not_adj (h : ¬G.Adj a b) (hn : a ≠ b) :
G.incidenceSet a ∩ G.incidenceSet b = ∅ := by
simp_rw [Set.eq_empty_iff_forall_not_mem, Set.mem_inter_iff, not_and]
intro u ha hb
exact h (G.adj_of_mem_incidenceSet hn ha hb)
#align simple_graph.incidence_set_inter_incidence_set_of_not_adj SimpleGraph.incidenceSet_inter_incidenceSet_of_not_adj
instance decidableMemIncidenceSet [DecidableEq V] [DecidableRel G.Adj] (v : V) :
DecidablePred (· ∈ G.incidenceSet v) :=
inferInstanceAs <| DecidablePred fun e => e ∈ G.edgeSet ∧ v ∈ e
#align simple_graph.decidable_mem_incidence_set SimpleGraph.decidableMemIncidenceSet
@[simp]
theorem mem_neighborSet (v w : V) : w ∈ G.neighborSet v ↔ G.Adj v w :=
Iff.rfl
#align simple_graph.mem_neighbor_set SimpleGraph.mem_neighborSet
lemma not_mem_neighborSet_self : a ∉ G.neighborSet a := by simp
#align simple_graph.not_mem_neighbor_set_self SimpleGraph.not_mem_neighborSet_self
@[simp]
theorem mem_incidenceSet (v w : V) : s(v, w) ∈ G.incidenceSet v ↔ G.Adj v w := by
simp [incidenceSet]
#align simple_graph.mem_incidence_set SimpleGraph.mem_incidenceSet
theorem mem_incidence_iff_neighbor {v w : V} :
s(v, w) ∈ G.incidenceSet v ↔ w ∈ G.neighborSet v := by
simp only [mem_incidenceSet, mem_neighborSet]
#align simple_graph.mem_incidence_iff_neighbor SimpleGraph.mem_incidence_iff_neighbor
| Mathlib/Combinatorics/SimpleGraph/Basic.lean | 782 | 790 | theorem adj_incidenceSet_inter {v : V} {e : Sym2 V} (he : e ∈ G.edgeSet) (h : v ∈ e) :
G.incidenceSet v ∩ G.incidenceSet (Sym2.Mem.other h) = {e} := by |
ext e'
simp only [incidenceSet, Set.mem_sep_iff, Set.mem_inter_iff, Set.mem_singleton_iff]
refine ⟨fun h' => ?_, ?_⟩
· rw [← Sym2.other_spec h]
exact (Sym2.mem_and_mem_iff (edge_other_ne G he h).symm).mp ⟨h'.1.2, h'.2.2⟩
· rintro rfl
exact ⟨⟨he, h⟩, he, Sym2.other_mem _⟩
|
import Mathlib.Analysis.Calculus.ContDiff.Basic
import Mathlib.Analysis.Calculus.Deriv.Mul
import Mathlib.Analysis.Calculus.Deriv.Shift
import Mathlib.Analysis.Calculus.IteratedDeriv.Defs
variable
{𝕜 : Type*} [NontriviallyNormedField 𝕜]
{F : Type*} [NormedAddCommGroup F] [NormedSpace 𝕜 F]
{R : Type*} [Semiring R] [Module R F] [SMulCommClass 𝕜 R F] [ContinuousConstSMul R F]
{n : ℕ} {x : 𝕜} {s : Set 𝕜} (hx : x ∈ s) (h : UniqueDiffOn 𝕜 s) {f g : 𝕜 → F}
theorem iteratedDerivWithin_add (hf : ContDiffOn 𝕜 n f s) (hg : ContDiffOn 𝕜 n g s) :
iteratedDerivWithin n (f + g) s x =
iteratedDerivWithin n f s x + iteratedDerivWithin n g s x := by
simp_rw [iteratedDerivWithin, iteratedFDerivWithin_add_apply hf hg h hx,
ContinuousMultilinearMap.add_apply]
theorem iteratedDerivWithin_congr (hfg : Set.EqOn f g s) :
Set.EqOn (iteratedDerivWithin n f s) (iteratedDerivWithin n g s) s := by
induction n generalizing f g with
| zero => rwa [iteratedDerivWithin_zero]
| succ n IH =>
intro y hy
have : UniqueDiffWithinAt 𝕜 s y := h.uniqueDiffWithinAt hy
rw [iteratedDerivWithin_succ this, iteratedDerivWithin_succ this]
exact derivWithin_congr (IH hfg) (IH hfg hy)
theorem iteratedDerivWithin_const_add (hn : 0 < n) (c : F) :
iteratedDerivWithin n (fun z => c + f z) s x = iteratedDerivWithin n f s x := by
obtain ⟨n, rfl⟩ := n.exists_eq_succ_of_ne_zero hn.ne'
rw [iteratedDerivWithin_succ' h hx, iteratedDerivWithin_succ' h hx]
refine iteratedDerivWithin_congr h ?_ hx
intro y hy
exact derivWithin_const_add (h.uniqueDiffWithinAt hy) _
theorem iteratedDerivWithin_const_neg (hn : 0 < n) (c : F) :
iteratedDerivWithin n (fun z => c - f z) s x = iteratedDerivWithin n (fun z => -f z) s x := by
obtain ⟨n, rfl⟩ := n.exists_eq_succ_of_ne_zero hn.ne'
rw [iteratedDerivWithin_succ' h hx, iteratedDerivWithin_succ' h hx]
refine iteratedDerivWithin_congr h ?_ hx
intro y hy
have : UniqueDiffWithinAt 𝕜 s y := h.uniqueDiffWithinAt hy
rw [derivWithin.neg this]
exact derivWithin_const_sub this _
theorem iteratedDerivWithin_const_smul (c : R) (hf : ContDiffOn 𝕜 n f s) :
iteratedDerivWithin n (c • f) s x = c • iteratedDerivWithin n f s x := by
simp_rw [iteratedDerivWithin]
rw [iteratedFDerivWithin_const_smul_apply hf h hx]
simp only [ContinuousMultilinearMap.smul_apply]
theorem iteratedDerivWithin_const_mul (c : 𝕜) {f : 𝕜 → 𝕜} (hf : ContDiffOn 𝕜 n f s) :
iteratedDerivWithin n (fun z => c * f z) s x = c * iteratedDerivWithin n f s x := by
simpa using iteratedDerivWithin_const_smul (F := 𝕜) hx h c hf
variable (f) in
theorem iteratedDerivWithin_neg :
iteratedDerivWithin n (-f) s x = -iteratedDerivWithin n f s x := by
rw [iteratedDerivWithin, iteratedDerivWithin, iteratedFDerivWithin_neg_apply h hx,
ContinuousMultilinearMap.neg_apply]
variable (f) in
theorem iteratedDerivWithin_neg' :
iteratedDerivWithin n (fun z => -f z) s x = -iteratedDerivWithin n f s x :=
iteratedDerivWithin_neg hx h f
| Mathlib/Analysis/Calculus/IteratedDeriv/Lemmas.lean | 79 | 83 | theorem iteratedDerivWithin_sub (hf : ContDiffOn 𝕜 n f s) (hg : ContDiffOn 𝕜 n g s) :
iteratedDerivWithin n (f - g) s x =
iteratedDerivWithin n f s x - iteratedDerivWithin n g s x := by |
rw [sub_eq_add_neg, sub_eq_add_neg, Pi.neg_def, iteratedDerivWithin_add hx h hf hg.neg,
iteratedDerivWithin_neg' hx h]
|
import Mathlib.Algebra.Polynomial.AlgebraMap
import Mathlib.Algebra.Polynomial.Monic
#align_import data.polynomial.lifts from "leanprover-community/mathlib"@"63417e01fbc711beaf25fa73b6edb395c0cfddd0"
open Polynomial
noncomputable section
namespace Polynomial
universe u v w
section Semiring
variable {R : Type u} [Semiring R] {S : Type v} [Semiring S] {f : R →+* S}
def lifts (f : R →+* S) : Subsemiring S[X] :=
RingHom.rangeS (mapRingHom f)
#align polynomial.lifts Polynomial.lifts
theorem mem_lifts (p : S[X]) : p ∈ lifts f ↔ ∃ q : R[X], map f q = p := by
simp only [coe_mapRingHom, lifts, RingHom.mem_rangeS]
#align polynomial.mem_lifts Polynomial.mem_lifts
theorem lifts_iff_set_range (p : S[X]) : p ∈ lifts f ↔ p ∈ Set.range (map f) := by
simp only [coe_mapRingHom, lifts, Set.mem_range, RingHom.mem_rangeS]
#align polynomial.lifts_iff_set_range Polynomial.lifts_iff_set_range
theorem lifts_iff_ringHom_rangeS (p : S[X]) : p ∈ lifts f ↔ p ∈ (mapRingHom f).rangeS := by
simp only [coe_mapRingHom, lifts, Set.mem_range, RingHom.mem_rangeS]
#align polynomial.lifts_iff_ring_hom_srange Polynomial.lifts_iff_ringHom_rangeS
theorem lifts_iff_coeff_lifts (p : S[X]) : p ∈ lifts f ↔ ∀ n : ℕ, p.coeff n ∈ Set.range f := by
rw [lifts_iff_ringHom_rangeS, mem_map_rangeS f]
rfl
#align polynomial.lifts_iff_coeff_lifts Polynomial.lifts_iff_coeff_lifts
theorem C_mem_lifts (f : R →+* S) (r : R) : C (f r) ∈ lifts f :=
⟨C r, by
simp only [coe_mapRingHom, map_C, Set.mem_univ, Subsemiring.coe_top, eq_self_iff_true,
and_self_iff]⟩
set_option linter.uppercaseLean3 false in
#align polynomial.C_mem_lifts Polynomial.C_mem_lifts
theorem C'_mem_lifts {f : R →+* S} {s : S} (h : s ∈ Set.range f) : C s ∈ lifts f := by
obtain ⟨r, rfl⟩ := Set.mem_range.1 h
use C r
simp only [coe_mapRingHom, map_C, Set.mem_univ, Subsemiring.coe_top, eq_self_iff_true,
and_self_iff]
set_option linter.uppercaseLean3 false in
#align polynomial.C'_mem_lifts Polynomial.C'_mem_lifts
theorem X_mem_lifts (f : R →+* S) : (X : S[X]) ∈ lifts f :=
⟨X, by
simp only [coe_mapRingHom, Set.mem_univ, Subsemiring.coe_top, eq_self_iff_true, map_X,
and_self_iff]⟩
set_option linter.uppercaseLean3 false in
#align polynomial.X_mem_lifts Polynomial.X_mem_lifts
theorem X_pow_mem_lifts (f : R →+* S) (n : ℕ) : (X ^ n : S[X]) ∈ lifts f :=
⟨X ^ n, by
simp only [coe_mapRingHom, map_pow, Set.mem_univ, Subsemiring.coe_top, eq_self_iff_true,
map_X, and_self_iff]⟩
set_option linter.uppercaseLean3 false in
#align polynomial.X_pow_mem_lifts Polynomial.X_pow_mem_lifts
| Mathlib/Algebra/Polynomial/Lifts.lean | 112 | 116 | theorem base_mul_mem_lifts {p : S[X]} (r : R) (hp : p ∈ lifts f) : C (f r) * p ∈ lifts f := by |
simp only [lifts, RingHom.mem_rangeS] at hp ⊢
obtain ⟨p₁, rfl⟩ := hp
use C r * p₁
simp only [coe_mapRingHom, map_C, map_mul]
|
import Mathlib.Algebra.MvPolynomial.PDeriv
import Mathlib.Algebra.Polynomial.AlgebraMap
import Mathlib.Algebra.Polynomial.Derivative
import Mathlib.Data.Nat.Choose.Sum
import Mathlib.LinearAlgebra.LinearIndependent
import Mathlib.RingTheory.Polynomial.Pochhammer
#align_import ring_theory.polynomial.bernstein from "leanprover-community/mathlib"@"bbeb185db4ccee8ed07dc48449414ebfa39cb821"
noncomputable section
open Nat (choose)
open Polynomial (X)
open scoped Polynomial
variable (R : Type*) [CommRing R]
def bernsteinPolynomial (n ν : ℕ) : R[X] :=
(choose n ν : R[X]) * X ^ ν * (1 - X) ^ (n - ν)
#align bernstein_polynomial bernsteinPolynomial
example : bernsteinPolynomial ℤ 3 2 = 3 * X ^ 2 - 3 * X ^ 3 := by
norm_num [bernsteinPolynomial, choose]
ring
namespace bernsteinPolynomial
theorem eq_zero_of_lt {n ν : ℕ} (h : n < ν) : bernsteinPolynomial R n ν = 0 := by
simp [bernsteinPolynomial, Nat.choose_eq_zero_of_lt h]
#align bernstein_polynomial.eq_zero_of_lt bernsteinPolynomial.eq_zero_of_lt
section
variable {R} {S : Type*} [CommRing S]
@[simp]
theorem map (f : R →+* S) (n ν : ℕ) :
(bernsteinPolynomial R n ν).map f = bernsteinPolynomial S n ν := by simp [bernsteinPolynomial]
#align bernstein_polynomial.map bernsteinPolynomial.map
end
theorem flip (n ν : ℕ) (h : ν ≤ n) :
(bernsteinPolynomial R n ν).comp (1 - X) = bernsteinPolynomial R n (n - ν) := by
simp [bernsteinPolynomial, h, tsub_tsub_assoc, mul_right_comm]
#align bernstein_polynomial.flip bernsteinPolynomial.flip
theorem flip' (n ν : ℕ) (h : ν ≤ n) :
bernsteinPolynomial R n ν = (bernsteinPolynomial R n (n - ν)).comp (1 - X) := by
simp [← flip _ _ _ h, Polynomial.comp_assoc]
#align bernstein_polynomial.flip' bernsteinPolynomial.flip'
theorem eval_at_0 (n ν : ℕ) : (bernsteinPolynomial R n ν).eval 0 = if ν = 0 then 1 else 0 := by
rw [bernsteinPolynomial]
split_ifs with h
· subst h; simp
· simp [zero_pow h]
#align bernstein_polynomial.eval_at_0 bernsteinPolynomial.eval_at_0
theorem eval_at_1 (n ν : ℕ) : (bernsteinPolynomial R n ν).eval 1 = if ν = n then 1 else 0 := by
rw [bernsteinPolynomial]
split_ifs with h
· subst h; simp
· obtain hνn | hnν := Ne.lt_or_lt h
· simp [zero_pow $ Nat.sub_ne_zero_of_lt hνn]
· simp [Nat.choose_eq_zero_of_lt hnν]
#align bernstein_polynomial.eval_at_1 bernsteinPolynomial.eval_at_1
theorem derivative_succ_aux (n ν : ℕ) :
Polynomial.derivative (bernsteinPolynomial R (n + 1) (ν + 1)) =
(n + 1) * (bernsteinPolynomial R n ν - bernsteinPolynomial R n (ν + 1)) := by
rw [bernsteinPolynomial]
suffices ((n + 1).choose (ν + 1) : R[X]) * ((↑(ν + 1 : ℕ) : R[X]) * X ^ ν) * (1 - X) ^ (n - ν) -
((n + 1).choose (ν + 1) : R[X]) * X ^ (ν + 1) * ((↑(n - ν) : R[X]) * (1 - X) ^ (n - ν - 1)) =
(↑(n + 1) : R[X]) * ((n.choose ν : R[X]) * X ^ ν * (1 - X) ^ (n - ν) -
(n.choose (ν + 1) : R[X]) * X ^ (ν + 1) * (1 - X) ^ (n - (ν + 1))) by
simpa [Polynomial.derivative_pow, ← sub_eq_add_neg, Nat.succ_sub_succ_eq_sub,
Polynomial.derivative_mul, Polynomial.derivative_natCast, zero_mul,
Nat.cast_add, algebraMap.coe_one, Polynomial.derivative_X, mul_one, zero_add,
Polynomial.derivative_sub, Polynomial.derivative_one, zero_sub, mul_neg, Nat.sub_zero,
bernsteinPolynomial, map_add, map_natCast, Nat.cast_one]
conv_rhs => rw [mul_sub]
-- We'll prove the two terms match up separately.
refine congr (congr_arg Sub.sub ?_) ?_
· simp only [← mul_assoc]
apply congr (congr_arg (· * ·) (congr (congr_arg (· * ·) _) rfl)) rfl
-- Now it's just about binomial coefficients
exact mod_cast congr_arg (fun m : ℕ => (m : R[X])) (Nat.succ_mul_choose_eq n ν).symm
· rw [← tsub_add_eq_tsub_tsub, ← mul_assoc, ← mul_assoc]; congr 1
rw [mul_comm, ← mul_assoc, ← mul_assoc]; congr 1
norm_cast
congr 1
convert (Nat.choose_mul_succ_eq n (ν + 1)).symm using 1
· -- Porting note: was
-- convert mul_comm _ _ using 2
-- simp
rw [mul_comm, Nat.succ_sub_succ_eq_sub]
· apply mul_comm
#align bernstein_polynomial.derivative_succ_aux bernsteinPolynomial.derivative_succ_aux
| Mathlib/RingTheory/Polynomial/Bernstein.lean | 134 | 138 | theorem derivative_succ (n ν : ℕ) : Polynomial.derivative (bernsteinPolynomial R n (ν + 1)) =
n * (bernsteinPolynomial R (n - 1) ν - bernsteinPolynomial R (n - 1) (ν + 1)) := by |
cases n
· simp [bernsteinPolynomial]
· rw [Nat.cast_succ]; apply derivative_succ_aux
|
import Mathlib.Data.Finset.Fin
import Mathlib.Data.Int.Order.Units
import Mathlib.GroupTheory.OrderOfElement
import Mathlib.GroupTheory.Perm.Support
import Mathlib.Logic.Equiv.Fintype
#align_import group_theory.perm.sign from "leanprover-community/mathlib"@"f694c7dead66f5d4c80f446c796a5aad14707f0e"
universe u v
open Equiv Function Fintype Finset
variable {α : Type u} {β : Type v}
-- An example on how to determine the order of an element of a finite group.
example : orderOf (-1 : ℤˣ) = 2 :=
orderOf_eq_prime (Int.units_sq _) (by decide)
namespace Equiv.Perm
theorem perm_inv_on_of_perm_on_finset {s : Finset α} {f : Perm α} (h : ∀ x ∈ s, f x ∈ s) {y : α}
(hy : y ∈ s) : f⁻¹ y ∈ s := by
have h0 : ∀ y ∈ s, ∃ (x : _) (hx : x ∈ s), y = (fun i (_ : i ∈ s) => f i) x hx :=
Finset.surj_on_of_inj_on_of_card_le (fun x hx => (fun i _ => f i) x hx) (fun a ha => h a ha)
(fun a₁ a₂ ha₁ ha₂ heq => (Equiv.apply_eq_iff_eq f).mp heq) rfl.ge
obtain ⟨y2, hy2, heq⟩ := h0 y hy
convert hy2
rw [heq]
simp only [inv_apply_self]
#align equiv.perm.perm_inv_on_of_perm_on_finset Equiv.Perm.perm_inv_on_of_perm_on_finset
theorem perm_inv_mapsTo_of_mapsTo (f : Perm α) {s : Set α} [Finite s] (h : Set.MapsTo f s s) :
Set.MapsTo (f⁻¹ : _) s s := by
cases nonempty_fintype s
exact fun x hx =>
Set.mem_toFinset.mp <|
perm_inv_on_of_perm_on_finset
(fun a ha => Set.mem_toFinset.mpr (h (Set.mem_toFinset.mp ha)))
(Set.mem_toFinset.mpr hx)
#align equiv.perm.perm_inv_maps_to_of_maps_to Equiv.Perm.perm_inv_mapsTo_of_mapsTo
@[simp]
theorem perm_inv_mapsTo_iff_mapsTo {f : Perm α} {s : Set α} [Finite s] :
Set.MapsTo (f⁻¹ : _) s s ↔ Set.MapsTo f s s :=
⟨perm_inv_mapsTo_of_mapsTo f⁻¹, perm_inv_mapsTo_of_mapsTo f⟩
#align equiv.perm.perm_inv_maps_to_iff_maps_to Equiv.Perm.perm_inv_mapsTo_iff_mapsTo
theorem perm_inv_on_of_perm_on_finite {f : Perm α} {p : α → Prop} [Finite { x // p x }]
(h : ∀ x, p x → p (f x)) {x : α} (hx : p x) : p (f⁻¹ x) :=
-- Porting note: relies heavily on the definitions of `Subtype` and `setOf` unfolding to their
-- underlying predicate.
have : Finite { x | p x } := ‹_›
perm_inv_mapsTo_of_mapsTo (s := {x | p x}) f h hx
#align equiv.perm.perm_inv_on_of_perm_on_finite Equiv.Perm.perm_inv_on_of_perm_on_finite
abbrev subtypePermOfFintype (f : Perm α) {p : α → Prop} [Finite { x // p x }]
(h : ∀ x, p x → p (f x)) : Perm { x // p x } :=
f.subtypePerm fun x => ⟨h x, fun h₂ => f.inv_apply_self x ▸ perm_inv_on_of_perm_on_finite h h₂⟩
#align equiv.perm.subtype_perm_of_fintype Equiv.Perm.subtypePermOfFintype
@[simp]
theorem subtypePermOfFintype_apply (f : Perm α) {p : α → Prop} [Finite { x // p x }]
(h : ∀ x, p x → p (f x)) (x : { x // p x }) : subtypePermOfFintype f h x = ⟨f x, h x x.2⟩ :=
rfl
#align equiv.perm.subtype_perm_of_fintype_apply Equiv.Perm.subtypePermOfFintype_apply
theorem subtypePermOfFintype_one (p : α → Prop) [Finite { x // p x }]
(h : ∀ x, p x → p ((1 : Perm α) x)) : @subtypePermOfFintype α 1 p _ h = 1 :=
rfl
#align equiv.perm.subtype_perm_of_fintype_one Equiv.Perm.subtypePermOfFintype_one
theorem perm_mapsTo_inl_iff_mapsTo_inr {m n : Type*} [Finite m] [Finite n] (σ : Perm (Sum m n)) :
Set.MapsTo σ (Set.range Sum.inl) (Set.range Sum.inl) ↔
Set.MapsTo σ (Set.range Sum.inr) (Set.range Sum.inr) := by
constructor <;>
( intro h
classical
rw [← perm_inv_mapsTo_iff_mapsTo] at h
intro x
cases' hx : σ x with l r)
· rintro ⟨a, rfl⟩
obtain ⟨y, hy⟩ := h ⟨l, rfl⟩
rw [← hx, σ.inv_apply_self] at hy
exact absurd hy Sum.inl_ne_inr
· rintro _; exact ⟨r, rfl⟩
· rintro _; exact ⟨l, rfl⟩
· rintro ⟨a, rfl⟩
obtain ⟨y, hy⟩ := h ⟨r, rfl⟩
rw [← hx, σ.inv_apply_self] at hy
exact absurd hy Sum.inr_ne_inl
#align equiv.perm.perm_maps_to_inl_iff_maps_to_inr Equiv.Perm.perm_mapsTo_inl_iff_mapsTo_inr
theorem mem_sumCongrHom_range_of_perm_mapsTo_inl {m n : Type*} [Finite m] [Finite n]
{σ : Perm (Sum m n)} (h : Set.MapsTo σ (Set.range Sum.inl) (Set.range Sum.inl)) :
σ ∈ (sumCongrHom m n).range := by
classical
have h1 : ∀ x : Sum m n, (∃ a : m, Sum.inl a = x) → ∃ a : m, Sum.inl a = σ x := by
rintro x ⟨a, ha⟩
apply h
rw [← ha]
exact ⟨a, rfl⟩
have h3 : ∀ x : Sum m n, (∃ b : n, Sum.inr b = x) → ∃ b : n, Sum.inr b = σ x := by
rintro x ⟨b, hb⟩
apply (perm_mapsTo_inl_iff_mapsTo_inr σ).mp h
rw [← hb]
exact ⟨b, rfl⟩
let σ₁' := subtypePermOfFintype σ h1
let σ₂' := subtypePermOfFintype σ h3
let σ₁ := permCongr (Equiv.ofInjective _ Sum.inl_injective).symm σ₁'
let σ₂ := permCongr (Equiv.ofInjective _ Sum.inr_injective).symm σ₂'
rw [MonoidHom.mem_range, Prod.exists]
use σ₁, σ₂
rw [Perm.sumCongrHom_apply]
ext x
cases' x with a b
· rw [Equiv.sumCongr_apply, Sum.map_inl, permCongr_apply, Equiv.symm_symm,
apply_ofInjective_symm Sum.inl_injective]
rw [ofInjective_apply, Subtype.coe_mk, Subtype.coe_mk]
-- This used to be `rw`, but we need `erw` after leanprover/lean4#2644
erw [subtypePerm_apply]
· rw [Equiv.sumCongr_apply, Sum.map_inr, permCongr_apply, Equiv.symm_symm,
apply_ofInjective_symm Sum.inr_injective]
erw [subtypePerm_apply]
rw [ofInjective_apply, Subtype.coe_mk, Subtype.coe_mk]
#align equiv.perm.mem_sum_congr_hom_range_of_perm_maps_to_inl Equiv.Perm.mem_sumCongrHom_range_of_perm_mapsTo_inl
nonrec theorem Disjoint.orderOf {σ τ : Perm α} (hστ : Disjoint σ τ) :
orderOf (σ * τ) = Nat.lcm (orderOf σ) (orderOf τ) :=
haveI h : ∀ n : ℕ, (σ * τ) ^ n = 1 ↔ σ ^ n = 1 ∧ τ ^ n = 1 := fun n => by
rw [hστ.commute.mul_pow, Disjoint.mul_eq_one_iff (hστ.pow_disjoint_pow n n)]
Nat.dvd_antisymm hστ.commute.orderOf_mul_dvd_lcm
(Nat.lcm_dvd
(orderOf_dvd_of_pow_eq_one ((h (orderOf (σ * τ))).mp (pow_orderOf_eq_one (σ * τ))).1)
(orderOf_dvd_of_pow_eq_one ((h (orderOf (σ * τ))).mp (pow_orderOf_eq_one (σ * τ))).2))
#align equiv.perm.disjoint.order_of Equiv.Perm.Disjoint.orderOf
theorem Disjoint.extendDomain {p : β → Prop} [DecidablePred p] (f : α ≃ Subtype p)
{σ τ : Perm α} (h : Disjoint σ τ) : Disjoint (σ.extendDomain f) (τ.extendDomain f) := by
intro b
by_cases pb : p b
· refine (h (f.symm ⟨b, pb⟩)).imp ?_ ?_ <;>
· intro h
rw [extendDomain_apply_subtype _ _ pb, h, apply_symm_apply, Subtype.coe_mk]
· left
rw [extendDomain_apply_not_subtype _ _ pb]
#align equiv.perm.disjoint.extend_domain Equiv.Perm.Disjoint.extendDomain
theorem Disjoint.isConj_mul [Finite α] {σ τ π ρ : Perm α} (hc1 : IsConj σ π)
(hc2 : IsConj τ ρ) (hd1 : Disjoint σ τ) (hd2 : Disjoint π ρ) : IsConj (σ * τ) (π * ρ) := by
classical
cases nonempty_fintype α
obtain ⟨f, rfl⟩ := isConj_iff.1 hc1
obtain ⟨g, rfl⟩ := isConj_iff.1 hc2
have hd1' := coe_inj.2 hd1.support_mul
have hd2' := coe_inj.2 hd2.support_mul
rw [coe_union] at *
have hd1'' := disjoint_coe.2 (disjoint_iff_disjoint_support.1 hd1)
have hd2'' := disjoint_coe.2 (disjoint_iff_disjoint_support.1 hd2)
refine isConj_of_support_equiv ?_ ?_
· refine
((Equiv.Set.ofEq hd1').trans (Equiv.Set.union hd1''.le_bot)).trans
((Equiv.sumCongr (subtypeEquiv f fun a => ?_) (subtypeEquiv g fun a => ?_)).trans
((Equiv.Set.ofEq hd2').trans (Equiv.Set.union hd2''.le_bot)).symm) <;>
· simp only [Set.mem_image, toEmbedding_apply, exists_eq_right, support_conj, coe_map,
apply_eq_iff_eq]
· intro x hx
simp only [trans_apply, symm_trans_apply, Equiv.Set.ofEq_apply, Equiv.Set.ofEq_symm_apply,
Equiv.sumCongr_apply]
rw [hd1', Set.mem_union] at hx
cases' hx with hxσ hxτ
· rw [mem_coe, mem_support] at hxσ
rw [Set.union_apply_left hd1''.le_bot _, Set.union_apply_left hd1''.le_bot _]
· simp only [subtypeEquiv_apply, Perm.coe_mul, Sum.map_inl, comp_apply,
Set.union_symm_apply_left, Subtype.coe_mk, apply_eq_iff_eq]
have h := (hd2 (f x)).resolve_left ?_
· rw [mul_apply, mul_apply] at h
rw [h, inv_apply_self, (hd1 x).resolve_left hxσ]
· rwa [mul_apply, mul_apply, inv_apply_self, apply_eq_iff_eq]
· rwa [Subtype.coe_mk, mem_coe, mem_support]
· rwa [Subtype.coe_mk, Perm.mul_apply, (hd1 x).resolve_left hxσ, mem_coe,
apply_mem_support, mem_support]
· rw [mem_coe, ← apply_mem_support, mem_support] at hxτ
rw [Set.union_apply_right hd1''.le_bot _, Set.union_apply_right hd1''.le_bot _]
· simp only [subtypeEquiv_apply, Perm.coe_mul, Sum.map_inr, comp_apply,
Set.union_symm_apply_right, Subtype.coe_mk, apply_eq_iff_eq]
have h := (hd2 (g (τ x))).resolve_right ?_
· rw [mul_apply, mul_apply] at h
rw [inv_apply_self, h, (hd1 (τ x)).resolve_right hxτ]
· rwa [mul_apply, mul_apply, inv_apply_self, apply_eq_iff_eq]
· rwa [Subtype.coe_mk, mem_coe, ← apply_mem_support, mem_support]
· rwa [Subtype.coe_mk, Perm.mul_apply, (hd1 (τ x)).resolve_right hxτ,
mem_coe, mem_support]
#align equiv.perm.disjoint.is_conj_mul Equiv.Perm.Disjoint.isConj_mul
variable [DecidableEq α]
section Fintype
variable [Fintype α]
| Mathlib/GroupTheory/Perm/Finite.lean | 241 | 246 | theorem support_pow_coprime {σ : Perm α} {n : ℕ} (h : Nat.Coprime n (orderOf σ)) :
(σ ^ n).support = σ.support := by |
obtain ⟨m, hm⟩ := exists_pow_eq_self_of_coprime h
exact
le_antisymm (support_pow_le σ n)
(le_trans (ge_of_eq (congr_arg support hm)) (support_pow_le (σ ^ n) m))
|
import Mathlib.Algebra.Group.Indicator
import Mathlib.Algebra.Group.Submonoid.Basic
import Mathlib.Data.Set.Finite
#align_import data.finsupp.defs from "leanprover-community/mathlib"@"842328d9df7e96fd90fc424e115679c15fb23a71"
noncomputable section
open Finset Function
variable {α β γ ι M M' N P G H R S : Type*}
structure Finsupp (α : Type*) (M : Type*) [Zero M] where
support : Finset α
toFun : α → M
mem_support_toFun : ∀ a, a ∈ support ↔ toFun a ≠ 0
#align finsupp Finsupp
#align finsupp.support Finsupp.support
#align finsupp.to_fun Finsupp.toFun
#align finsupp.mem_support_to_fun Finsupp.mem_support_toFun
@[inherit_doc]
infixr:25 " →₀ " => Finsupp
namespace Finsupp
instance instAddCommMonoid [AddCommMonoid M] : AddCommMonoid (α →₀ M) :=
--TODO: add reference to library note in PR #7432
{ DFunLike.coe_injective.addCommMonoid (↑) coe_zero coe_add (fun _ _ => rfl) with
toAddMonoid := Finsupp.instAddMonoid }
#align finsupp.add_comm_monoid Finsupp.instAddCommMonoid
instance instNeg [NegZeroClass G] : Neg (α →₀ G) :=
⟨mapRange Neg.neg neg_zero⟩
#align finsupp.has_neg Finsupp.instNeg
@[simp, norm_cast] lemma coe_neg [NegZeroClass G] (g : α →₀ G) : ⇑(-g) = -g := rfl
#align finsupp.coe_neg Finsupp.coe_neg
theorem neg_apply [NegZeroClass G] (g : α →₀ G) (a : α) : (-g) a = -g a :=
rfl
#align finsupp.neg_apply Finsupp.neg_apply
theorem mapRange_neg [NegZeroClass G] [NegZeroClass H] {f : G → H} {hf : f 0 = 0}
(hf' : ∀ x, f (-x) = -f x) (v : α →₀ G) : mapRange f hf (-v) = -mapRange f hf v :=
ext fun _ => by simp only [hf', neg_apply, mapRange_apply]
#align finsupp.map_range_neg Finsupp.mapRange_neg
theorem mapRange_neg' [AddGroup G] [SubtractionMonoid H] [FunLike β G H] [AddMonoidHomClass β G H]
{f : β} (v : α →₀ G) :
mapRange f (map_zero f) (-v) = -mapRange f (map_zero f) v :=
mapRange_neg (map_neg f) v
#align finsupp.map_range_neg' Finsupp.mapRange_neg'
instance instSub [SubNegZeroMonoid G] : Sub (α →₀ G) :=
⟨zipWith Sub.sub (sub_zero _)⟩
#align finsupp.has_sub Finsupp.instSub
@[simp, norm_cast] lemma coe_sub [SubNegZeroMonoid G] (g₁ g₂ : α →₀ G) : ⇑(g₁ - g₂) = g₁ - g₂ := rfl
#align finsupp.coe_sub Finsupp.coe_sub
theorem sub_apply [SubNegZeroMonoid G] (g₁ g₂ : α →₀ G) (a : α) : (g₁ - g₂) a = g₁ a - g₂ a :=
rfl
#align finsupp.sub_apply Finsupp.sub_apply
theorem mapRange_sub [SubNegZeroMonoid G] [SubNegZeroMonoid H] {f : G → H} {hf : f 0 = 0}
(hf' : ∀ x y, f (x - y) = f x - f y) (v₁ v₂ : α →₀ G) :
mapRange f hf (v₁ - v₂) = mapRange f hf v₁ - mapRange f hf v₂ :=
ext fun _ => by simp only [hf', sub_apply, mapRange_apply]
#align finsupp.map_range_sub Finsupp.mapRange_sub
theorem mapRange_sub' [AddGroup G] [SubtractionMonoid H] [FunLike β G H] [AddMonoidHomClass β G H]
{f : β} (v₁ v₂ : α →₀ G) :
mapRange f (map_zero f) (v₁ - v₂) = mapRange f (map_zero f) v₁ - mapRange f (map_zero f) v₂ :=
mapRange_sub (map_sub f) v₁ v₂
#align finsupp.map_range_sub' Finsupp.mapRange_sub'
instance instIntSMul [AddGroup G] : SMul ℤ (α →₀ G) :=
⟨fun n v => v.mapRange (n • ·) (zsmul_zero _)⟩
#align finsupp.has_int_scalar Finsupp.instIntSMul
instance instAddGroup [AddGroup G] : AddGroup (α →₀ G) :=
--TODO: add reference to library note in PR #7432
{ DFunLike.coe_injective.addGroup (↑) coe_zero coe_add coe_neg coe_sub (fun _ _ => rfl)
fun _ _ => rfl with
toAddMonoid := Finsupp.instAddMonoid }
#align finsupp.add_group Finsupp.instAddGroup
instance instAddCommGroup [AddCommGroup G] : AddCommGroup (α →₀ G) :=
--TODO: add reference to library note in PR #7432
{ DFunLike.coe_injective.addCommGroup (↑) coe_zero coe_add coe_neg coe_sub (fun _ _ => rfl)
fun _ _ => rfl with
toAddGroup := Finsupp.instAddGroup }
#align finsupp.add_comm_group Finsupp.instAddCommGroup
| Mathlib/Data/Finsupp/Defs.lean | 1,349 | 1,355 | theorem single_add_single_eq_single_add_single [AddCommMonoid M] {k l m n : α} {u v : M}
(hu : u ≠ 0) (hv : v ≠ 0) :
single k u + single l v = single m u + single n v ↔
(k = m ∧ l = n) ∨ (u = v ∧ k = n ∧ l = m) ∨ (u + v = 0 ∧ k = l ∧ m = n) := by |
classical
simp_rw [DFunLike.ext_iff, coe_add, single_eq_pi_single, ← funext_iff]
exact Pi.single_add_single_eq_single_add_single hu hv
|
import Mathlib.Init.ZeroOne
import Mathlib.Data.Set.Defs
import Mathlib.Order.Basic
import Mathlib.Order.SymmDiff
import Mathlib.Tactic.Tauto
import Mathlib.Tactic.ByContra
import Mathlib.Util.Delaborators
#align_import data.set.basic from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29"
open Function
universe u v w x
namespace Set
variable {α : Type u} {s t : Set α}
instance instBooleanAlgebraSet : BooleanAlgebra (Set α) :=
{ (inferInstance : BooleanAlgebra (α → Prop)) with
sup := (· ∪ ·),
le := (· ≤ ·),
lt := fun s t => s ⊆ t ∧ ¬t ⊆ s,
inf := (· ∩ ·),
bot := ∅,
compl := (·ᶜ),
top := univ,
sdiff := (· \ ·) }
instance : HasSSubset (Set α) :=
⟨(· < ·)⟩
@[simp]
theorem top_eq_univ : (⊤ : Set α) = univ :=
rfl
#align set.top_eq_univ Set.top_eq_univ
@[simp]
theorem bot_eq_empty : (⊥ : Set α) = ∅ :=
rfl
#align set.bot_eq_empty Set.bot_eq_empty
@[simp]
theorem sup_eq_union : ((· ⊔ ·) : Set α → Set α → Set α) = (· ∪ ·) :=
rfl
#align set.sup_eq_union Set.sup_eq_union
@[simp]
theorem inf_eq_inter : ((· ⊓ ·) : Set α → Set α → Set α) = (· ∩ ·) :=
rfl
#align set.inf_eq_inter Set.inf_eq_inter
@[simp]
theorem le_eq_subset : ((· ≤ ·) : Set α → Set α → Prop) = (· ⊆ ·) :=
rfl
#align set.le_eq_subset Set.le_eq_subset
@[simp]
theorem lt_eq_ssubset : ((· < ·) : Set α → Set α → Prop) = (· ⊂ ·) :=
rfl
#align set.lt_eq_ssubset Set.lt_eq_ssubset
theorem le_iff_subset : s ≤ t ↔ s ⊆ t :=
Iff.rfl
#align set.le_iff_subset Set.le_iff_subset
theorem lt_iff_ssubset : s < t ↔ s ⊂ t :=
Iff.rfl
#align set.lt_iff_ssubset Set.lt_iff_ssubset
alias ⟨_root_.LE.le.subset, _root_.HasSubset.Subset.le⟩ := le_iff_subset
#align has_subset.subset.le HasSubset.Subset.le
alias ⟨_root_.LT.lt.ssubset, _root_.HasSSubset.SSubset.lt⟩ := lt_iff_ssubset
#align has_ssubset.ssubset.lt HasSSubset.SSubset.lt
instance PiSetCoe.canLift (ι : Type u) (α : ι → Type v) [∀ i, Nonempty (α i)] (s : Set ι) :
CanLift (∀ i : s, α i) (∀ i, α i) (fun f i => f i) fun _ => True :=
PiSubtype.canLift ι α s
#align set.pi_set_coe.can_lift Set.PiSetCoe.canLift
instance PiSetCoe.canLift' (ι : Type u) (α : Type v) [Nonempty α] (s : Set ι) :
CanLift (s → α) (ι → α) (fun f i => f i) fun _ => True :=
PiSetCoe.canLift ι (fun _ => α) s
#align set.pi_set_coe.can_lift' Set.PiSetCoe.canLift'
end Set
theorem Subtype.mem {α : Type*} {s : Set α} (p : s) : (p : α) ∈ s :=
p.prop
#align subtype.mem Subtype.mem
theorem Eq.subset {α} {s t : Set α} : s = t → s ⊆ t :=
fun h₁ _ h₂ => by rw [← h₁]; exact h₂
#align eq.subset Eq.subset
namespace Set
variable {α : Type u} {β : Type v} {γ : Type w} {ι : Sort x} {a b : α} {s s₁ s₂ t t₁ t₂ u : Set α}
instance : Inhabited (Set α) :=
⟨∅⟩
theorem ext_iff {s t : Set α} : s = t ↔ ∀ x, x ∈ s ↔ x ∈ t :=
⟨fun h x => by rw [h], ext⟩
#align set.ext_iff Set.ext_iff
@[trans]
theorem mem_of_mem_of_subset {x : α} {s t : Set α} (hx : x ∈ s) (h : s ⊆ t) : x ∈ t :=
h hx
#align set.mem_of_mem_of_subset Set.mem_of_mem_of_subset
theorem forall_in_swap {p : α → β → Prop} : (∀ a ∈ s, ∀ (b), p a b) ↔ ∀ (b), ∀ a ∈ s, p a b := by
tauto
#align set.forall_in_swap Set.forall_in_swap
theorem mem_setOf {a : α} {p : α → Prop} : a ∈ { x | p x } ↔ p a :=
Iff.rfl
#align set.mem_set_of Set.mem_setOf
theorem _root_.Membership.mem.out {p : α → Prop} {a : α} (h : a ∈ { x | p x }) : p a :=
h
#align has_mem.mem.out Membership.mem.out
theorem nmem_setOf_iff {a : α} {p : α → Prop} : a ∉ { x | p x } ↔ ¬p a :=
Iff.rfl
#align set.nmem_set_of_iff Set.nmem_setOf_iff
@[simp]
theorem setOf_mem_eq {s : Set α} : { x | x ∈ s } = s :=
rfl
#align set.set_of_mem_eq Set.setOf_mem_eq
theorem setOf_set {s : Set α} : setOf s = s :=
rfl
#align set.set_of_set Set.setOf_set
theorem setOf_app_iff {p : α → Prop} {x : α} : { x | p x } x ↔ p x :=
Iff.rfl
#align set.set_of_app_iff Set.setOf_app_iff
theorem mem_def {a : α} {s : Set α} : a ∈ s ↔ s a :=
Iff.rfl
#align set.mem_def Set.mem_def
theorem setOf_bijective : Bijective (setOf : (α → Prop) → Set α) :=
bijective_id
#align set.set_of_bijective Set.setOf_bijective
theorem subset_setOf {p : α → Prop} {s : Set α} : s ⊆ setOf p ↔ ∀ x, x ∈ s → p x :=
Iff.rfl
theorem setOf_subset {p : α → Prop} {s : Set α} : setOf p ⊆ s ↔ ∀ x, p x → x ∈ s :=
Iff.rfl
@[simp]
theorem setOf_subset_setOf {p q : α → Prop} : { a | p a } ⊆ { a | q a } ↔ ∀ a, p a → q a :=
Iff.rfl
#align set.set_of_subset_set_of Set.setOf_subset_setOf
theorem setOf_and {p q : α → Prop} : { a | p a ∧ q a } = { a | p a } ∩ { a | q a } :=
rfl
#align set.set_of_and Set.setOf_and
theorem setOf_or {p q : α → Prop} : { a | p a ∨ q a } = { a | p a } ∪ { a | q a } :=
rfl
#align set.set_of_or Set.setOf_or
instance : IsRefl (Set α) (· ⊆ ·) :=
show IsRefl (Set α) (· ≤ ·) by infer_instance
instance : IsTrans (Set α) (· ⊆ ·) :=
show IsTrans (Set α) (· ≤ ·) by infer_instance
instance : Trans ((· ⊆ ·) : Set α → Set α → Prop) (· ⊆ ·) (· ⊆ ·) :=
show Trans (· ≤ ·) (· ≤ ·) (· ≤ ·) by infer_instance
instance : IsAntisymm (Set α) (· ⊆ ·) :=
show IsAntisymm (Set α) (· ≤ ·) by infer_instance
instance : IsIrrefl (Set α) (· ⊂ ·) :=
show IsIrrefl (Set α) (· < ·) by infer_instance
instance : IsTrans (Set α) (· ⊂ ·) :=
show IsTrans (Set α) (· < ·) by infer_instance
instance : Trans ((· ⊂ ·) : Set α → Set α → Prop) (· ⊂ ·) (· ⊂ ·) :=
show Trans (· < ·) (· < ·) (· < ·) by infer_instance
instance : Trans ((· ⊂ ·) : Set α → Set α → Prop) (· ⊆ ·) (· ⊂ ·) :=
show Trans (· < ·) (· ≤ ·) (· < ·) by infer_instance
instance : Trans ((· ⊆ ·) : Set α → Set α → Prop) (· ⊂ ·) (· ⊂ ·) :=
show Trans (· ≤ ·) (· < ·) (· < ·) by infer_instance
instance : IsAsymm (Set α) (· ⊂ ·) :=
show IsAsymm (Set α) (· < ·) by infer_instance
instance : IsNonstrictStrictOrder (Set α) (· ⊆ ·) (· ⊂ ·) :=
⟨fun _ _ => Iff.rfl⟩
-- TODO(Jeremy): write a tactic to unfold specific instances of generic notation?
theorem subset_def : (s ⊆ t) = ∀ x, x ∈ s → x ∈ t :=
rfl
#align set.subset_def Set.subset_def
theorem ssubset_def : (s ⊂ t) = (s ⊆ t ∧ ¬t ⊆ s) :=
rfl
#align set.ssubset_def Set.ssubset_def
@[refl]
theorem Subset.refl (a : Set α) : a ⊆ a := fun _ => id
#align set.subset.refl Set.Subset.refl
theorem Subset.rfl {s : Set α} : s ⊆ s :=
Subset.refl s
#align set.subset.rfl Set.Subset.rfl
@[trans]
theorem Subset.trans {a b c : Set α} (ab : a ⊆ b) (bc : b ⊆ c) : a ⊆ c := fun _ h => bc <| ab h
#align set.subset.trans Set.Subset.trans
@[trans]
theorem mem_of_eq_of_mem {x y : α} {s : Set α} (hx : x = y) (h : y ∈ s) : x ∈ s :=
hx.symm ▸ h
#align set.mem_of_eq_of_mem Set.mem_of_eq_of_mem
theorem Subset.antisymm {a b : Set α} (h₁ : a ⊆ b) (h₂ : b ⊆ a) : a = b :=
Set.ext fun _ => ⟨@h₁ _, @h₂ _⟩
#align set.subset.antisymm Set.Subset.antisymm
theorem Subset.antisymm_iff {a b : Set α} : a = b ↔ a ⊆ b ∧ b ⊆ a :=
⟨fun e => ⟨e.subset, e.symm.subset⟩, fun ⟨h₁, h₂⟩ => Subset.antisymm h₁ h₂⟩
#align set.subset.antisymm_iff Set.Subset.antisymm_iff
-- an alternative name
theorem eq_of_subset_of_subset {a b : Set α} : a ⊆ b → b ⊆ a → a = b :=
Subset.antisymm
#align set.eq_of_subset_of_subset Set.eq_of_subset_of_subset
theorem mem_of_subset_of_mem {s₁ s₂ : Set α} {a : α} (h : s₁ ⊆ s₂) : a ∈ s₁ → a ∈ s₂ :=
@h _
#align set.mem_of_subset_of_mem Set.mem_of_subset_of_mem
theorem not_mem_subset (h : s ⊆ t) : a ∉ t → a ∉ s :=
mt <| mem_of_subset_of_mem h
#align set.not_mem_subset Set.not_mem_subset
theorem not_subset : ¬s ⊆ t ↔ ∃ a ∈ s, a ∉ t := by
simp only [subset_def, not_forall, exists_prop]
#align set.not_subset Set.not_subset
lemma eq_of_forall_subset_iff (h : ∀ u, s ⊆ u ↔ t ⊆ u) : s = t := eq_of_forall_ge_iff h
protected theorem eq_or_ssubset_of_subset (h : s ⊆ t) : s = t ∨ s ⊂ t :=
eq_or_lt_of_le h
#align set.eq_or_ssubset_of_subset Set.eq_or_ssubset_of_subset
theorem exists_of_ssubset {s t : Set α} (h : s ⊂ t) : ∃ x ∈ t, x ∉ s :=
not_subset.1 h.2
#align set.exists_of_ssubset Set.exists_of_ssubset
protected theorem ssubset_iff_subset_ne {s t : Set α} : s ⊂ t ↔ s ⊆ t ∧ s ≠ t :=
@lt_iff_le_and_ne (Set α) _ s t
#align set.ssubset_iff_subset_ne Set.ssubset_iff_subset_ne
theorem ssubset_iff_of_subset {s t : Set α} (h : s ⊆ t) : s ⊂ t ↔ ∃ x ∈ t, x ∉ s :=
⟨exists_of_ssubset, fun ⟨_, hxt, hxs⟩ => ⟨h, fun h => hxs <| h hxt⟩⟩
#align set.ssubset_iff_of_subset Set.ssubset_iff_of_subset
protected theorem ssubset_of_ssubset_of_subset {s₁ s₂ s₃ : Set α} (hs₁s₂ : s₁ ⊂ s₂)
(hs₂s₃ : s₂ ⊆ s₃) : s₁ ⊂ s₃ :=
⟨Subset.trans hs₁s₂.1 hs₂s₃, fun hs₃s₁ => hs₁s₂.2 (Subset.trans hs₂s₃ hs₃s₁)⟩
#align set.ssubset_of_ssubset_of_subset Set.ssubset_of_ssubset_of_subset
protected theorem ssubset_of_subset_of_ssubset {s₁ s₂ s₃ : Set α} (hs₁s₂ : s₁ ⊆ s₂)
(hs₂s₃ : s₂ ⊂ s₃) : s₁ ⊂ s₃ :=
⟨Subset.trans hs₁s₂ hs₂s₃.1, fun hs₃s₁ => hs₂s₃.2 (Subset.trans hs₃s₁ hs₁s₂)⟩
#align set.ssubset_of_subset_of_ssubset Set.ssubset_of_subset_of_ssubset
theorem not_mem_empty (x : α) : ¬x ∈ (∅ : Set α) :=
id
#align set.not_mem_empty Set.not_mem_empty
-- Porting note (#10618): removed `simp` because `simp` can prove it
theorem not_not_mem : ¬a ∉ s ↔ a ∈ s :=
not_not
#align set.not_not_mem Set.not_not_mem
-- Porting note: we seem to need parentheses at `(↥s)`,
-- even if we increase the right precedence of `↥` in `Mathlib.Tactic.Coe`.
-- Porting note: removed `simp` as it is competing with `nonempty_subtype`.
-- @[simp]
theorem nonempty_coe_sort {s : Set α} : Nonempty (↥s) ↔ s.Nonempty :=
nonempty_subtype
#align set.nonempty_coe_sort Set.nonempty_coe_sort
alias ⟨_, Nonempty.coe_sort⟩ := nonempty_coe_sort
#align set.nonempty.coe_sort Set.Nonempty.coe_sort
theorem nonempty_def : s.Nonempty ↔ ∃ x, x ∈ s :=
Iff.rfl
#align set.nonempty_def Set.nonempty_def
theorem nonempty_of_mem {x} (h : x ∈ s) : s.Nonempty :=
⟨x, h⟩
#align set.nonempty_of_mem Set.nonempty_of_mem
theorem Nonempty.not_subset_empty : s.Nonempty → ¬s ⊆ ∅
| ⟨_, hx⟩, hs => hs hx
#align set.nonempty.not_subset_empty Set.Nonempty.not_subset_empty
protected noncomputable def Nonempty.some (h : s.Nonempty) : α :=
Classical.choose h
#align set.nonempty.some Set.Nonempty.some
protected theorem Nonempty.some_mem (h : s.Nonempty) : h.some ∈ s :=
Classical.choose_spec h
#align set.nonempty.some_mem Set.Nonempty.some_mem
theorem Nonempty.mono (ht : s ⊆ t) (hs : s.Nonempty) : t.Nonempty :=
hs.imp ht
#align set.nonempty.mono Set.Nonempty.mono
theorem nonempty_of_not_subset (h : ¬s ⊆ t) : (s \ t).Nonempty :=
let ⟨x, xs, xt⟩ := not_subset.1 h
⟨x, xs, xt⟩
#align set.nonempty_of_not_subset Set.nonempty_of_not_subset
theorem nonempty_of_ssubset (ht : s ⊂ t) : (t \ s).Nonempty :=
nonempty_of_not_subset ht.2
#align set.nonempty_of_ssubset Set.nonempty_of_ssubset
theorem Nonempty.of_diff (h : (s \ t).Nonempty) : s.Nonempty :=
h.imp fun _ => And.left
#align set.nonempty.of_diff Set.Nonempty.of_diff
theorem nonempty_of_ssubset' (ht : s ⊂ t) : t.Nonempty :=
(nonempty_of_ssubset ht).of_diff
#align set.nonempty_of_ssubset' Set.nonempty_of_ssubset'
theorem Nonempty.inl (hs : s.Nonempty) : (s ∪ t).Nonempty :=
hs.imp fun _ => Or.inl
#align set.nonempty.inl Set.Nonempty.inl
theorem Nonempty.inr (ht : t.Nonempty) : (s ∪ t).Nonempty :=
ht.imp fun _ => Or.inr
#align set.nonempty.inr Set.Nonempty.inr
@[simp]
theorem union_nonempty : (s ∪ t).Nonempty ↔ s.Nonempty ∨ t.Nonempty :=
exists_or
#align set.union_nonempty Set.union_nonempty
theorem Nonempty.left (h : (s ∩ t).Nonempty) : s.Nonempty :=
h.imp fun _ => And.left
#align set.nonempty.left Set.Nonempty.left
theorem Nonempty.right (h : (s ∩ t).Nonempty) : t.Nonempty :=
h.imp fun _ => And.right
#align set.nonempty.right Set.Nonempty.right
theorem inter_nonempty : (s ∩ t).Nonempty ↔ ∃ x, x ∈ s ∧ x ∈ t :=
Iff.rfl
#align set.inter_nonempty Set.inter_nonempty
theorem inter_nonempty_iff_exists_left : (s ∩ t).Nonempty ↔ ∃ x ∈ s, x ∈ t := by
simp_rw [inter_nonempty]
#align set.inter_nonempty_iff_exists_left Set.inter_nonempty_iff_exists_left
theorem inter_nonempty_iff_exists_right : (s ∩ t).Nonempty ↔ ∃ x ∈ t, x ∈ s := by
simp_rw [inter_nonempty, and_comm]
#align set.inter_nonempty_iff_exists_right Set.inter_nonempty_iff_exists_right
theorem nonempty_iff_univ_nonempty : Nonempty α ↔ (univ : Set α).Nonempty :=
⟨fun ⟨x⟩ => ⟨x, trivial⟩, fun ⟨x, _⟩ => ⟨x⟩⟩
#align set.nonempty_iff_univ_nonempty Set.nonempty_iff_univ_nonempty
@[simp]
theorem univ_nonempty : ∀ [Nonempty α], (univ : Set α).Nonempty
| ⟨x⟩ => ⟨x, trivial⟩
#align set.univ_nonempty Set.univ_nonempty
theorem Nonempty.to_subtype : s.Nonempty → Nonempty (↥s) :=
nonempty_subtype.2
#align set.nonempty.to_subtype Set.Nonempty.to_subtype
theorem Nonempty.to_type : s.Nonempty → Nonempty α := fun ⟨x, _⟩ => ⟨x⟩
#align set.nonempty.to_type Set.Nonempty.to_type
instance univ.nonempty [Nonempty α] : Nonempty (↥(Set.univ : Set α)) :=
Set.univ_nonempty.to_subtype
#align set.univ.nonempty Set.univ.nonempty
theorem nonempty_of_nonempty_subtype [Nonempty (↥s)] : s.Nonempty :=
nonempty_subtype.mp ‹_›
#align set.nonempty_of_nonempty_subtype Set.nonempty_of_nonempty_subtype
theorem empty_def : (∅ : Set α) = { _x : α | False } :=
rfl
#align set.empty_def Set.empty_def
@[simp]
theorem mem_empty_iff_false (x : α) : x ∈ (∅ : Set α) ↔ False :=
Iff.rfl
#align set.mem_empty_iff_false Set.mem_empty_iff_false
@[simp]
theorem setOf_false : { _a : α | False } = ∅ :=
rfl
#align set.set_of_false Set.setOf_false
@[simp] theorem setOf_bot : { _x : α | ⊥ } = ∅ := rfl
@[simp]
theorem empty_subset (s : Set α) : ∅ ⊆ s :=
nofun
#align set.empty_subset Set.empty_subset
theorem subset_empty_iff {s : Set α} : s ⊆ ∅ ↔ s = ∅ :=
(Subset.antisymm_iff.trans <| and_iff_left (empty_subset _)).symm
#align set.subset_empty_iff Set.subset_empty_iff
theorem eq_empty_iff_forall_not_mem {s : Set α} : s = ∅ ↔ ∀ x, x ∉ s :=
subset_empty_iff.symm
#align set.eq_empty_iff_forall_not_mem Set.eq_empty_iff_forall_not_mem
theorem eq_empty_of_forall_not_mem (h : ∀ x, x ∉ s) : s = ∅ :=
subset_empty_iff.1 h
#align set.eq_empty_of_forall_not_mem Set.eq_empty_of_forall_not_mem
theorem eq_empty_of_subset_empty {s : Set α} : s ⊆ ∅ → s = ∅ :=
subset_empty_iff.1
#align set.eq_empty_of_subset_empty Set.eq_empty_of_subset_empty
theorem eq_empty_of_isEmpty [IsEmpty α] (s : Set α) : s = ∅ :=
eq_empty_of_subset_empty fun x _ => isEmptyElim x
#align set.eq_empty_of_is_empty Set.eq_empty_of_isEmpty
instance uniqueEmpty [IsEmpty α] : Unique (Set α) where
default := ∅
uniq := eq_empty_of_isEmpty
#align set.unique_empty Set.uniqueEmpty
theorem not_nonempty_iff_eq_empty {s : Set α} : ¬s.Nonempty ↔ s = ∅ := by
simp only [Set.Nonempty, not_exists, eq_empty_iff_forall_not_mem]
#align set.not_nonempty_iff_eq_empty Set.not_nonempty_iff_eq_empty
theorem nonempty_iff_ne_empty : s.Nonempty ↔ s ≠ ∅ :=
not_nonempty_iff_eq_empty.not_right
#align set.nonempty_iff_ne_empty Set.nonempty_iff_ne_empty
theorem not_nonempty_iff_eq_empty' : ¬Nonempty s ↔ s = ∅ := by
rw [nonempty_subtype, not_exists, eq_empty_iff_forall_not_mem]
theorem nonempty_iff_ne_empty' : Nonempty s ↔ s ≠ ∅ :=
not_nonempty_iff_eq_empty'.not_right
alias ⟨Nonempty.ne_empty, _⟩ := nonempty_iff_ne_empty
#align set.nonempty.ne_empty Set.Nonempty.ne_empty
@[simp]
theorem not_nonempty_empty : ¬(∅ : Set α).Nonempty := fun ⟨_, hx⟩ => hx
#align set.not_nonempty_empty Set.not_nonempty_empty
-- Porting note: removing `@[simp]` as it is competing with `isEmpty_subtype`.
-- @[simp]
theorem isEmpty_coe_sort {s : Set α} : IsEmpty (↥s) ↔ s = ∅ :=
not_iff_not.1 <| by simpa using nonempty_iff_ne_empty
#align set.is_empty_coe_sort Set.isEmpty_coe_sort
theorem eq_empty_or_nonempty (s : Set α) : s = ∅ ∨ s.Nonempty :=
or_iff_not_imp_left.2 nonempty_iff_ne_empty.2
#align set.eq_empty_or_nonempty Set.eq_empty_or_nonempty
theorem subset_eq_empty {s t : Set α} (h : t ⊆ s) (e : s = ∅) : t = ∅ :=
subset_empty_iff.1 <| e ▸ h
#align set.subset_eq_empty Set.subset_eq_empty
theorem forall_mem_empty {p : α → Prop} : (∀ x ∈ (∅ : Set α), p x) ↔ True :=
iff_true_intro fun _ => False.elim
#align set.ball_empty_iff Set.forall_mem_empty
@[deprecated (since := "2024-03-23")] alias ball_empty_iff := forall_mem_empty
instance (α : Type u) : IsEmpty.{u + 1} (↥(∅ : Set α)) :=
⟨fun x => x.2⟩
@[simp]
theorem empty_ssubset : ∅ ⊂ s ↔ s.Nonempty :=
(@bot_lt_iff_ne_bot (Set α) _ _ _).trans nonempty_iff_ne_empty.symm
#align set.empty_ssubset Set.empty_ssubset
alias ⟨_, Nonempty.empty_ssubset⟩ := empty_ssubset
#align set.nonempty.empty_ssubset Set.Nonempty.empty_ssubset
@[simp]
theorem setOf_true : { _x : α | True } = univ :=
rfl
#align set.set_of_true Set.setOf_true
@[simp] theorem setOf_top : { _x : α | ⊤ } = univ := rfl
@[simp]
theorem univ_eq_empty_iff : (univ : Set α) = ∅ ↔ IsEmpty α :=
eq_empty_iff_forall_not_mem.trans
⟨fun H => ⟨fun x => H x trivial⟩, fun H x _ => @IsEmpty.false α H x⟩
#align set.univ_eq_empty_iff Set.univ_eq_empty_iff
theorem empty_ne_univ [Nonempty α] : (∅ : Set α) ≠ univ := fun e =>
not_isEmpty_of_nonempty α <| univ_eq_empty_iff.1 e.symm
#align set.empty_ne_univ Set.empty_ne_univ
@[simp]
theorem subset_univ (s : Set α) : s ⊆ univ := fun _ _ => trivial
#align set.subset_univ Set.subset_univ
@[simp]
theorem univ_subset_iff {s : Set α} : univ ⊆ s ↔ s = univ :=
@top_le_iff _ _ _ s
#align set.univ_subset_iff Set.univ_subset_iff
alias ⟨eq_univ_of_univ_subset, _⟩ := univ_subset_iff
#align set.eq_univ_of_univ_subset Set.eq_univ_of_univ_subset
theorem eq_univ_iff_forall {s : Set α} : s = univ ↔ ∀ x, x ∈ s :=
univ_subset_iff.symm.trans <| forall_congr' fun _ => imp_iff_right trivial
#align set.eq_univ_iff_forall Set.eq_univ_iff_forall
theorem eq_univ_of_forall {s : Set α} : (∀ x, x ∈ s) → s = univ :=
eq_univ_iff_forall.2
#align set.eq_univ_of_forall Set.eq_univ_of_forall
theorem Nonempty.eq_univ [Subsingleton α] : s.Nonempty → s = univ := by
rintro ⟨x, hx⟩
exact eq_univ_of_forall fun y => by rwa [Subsingleton.elim y x]
#align set.nonempty.eq_univ Set.Nonempty.eq_univ
theorem eq_univ_of_subset {s t : Set α} (h : s ⊆ t) (hs : s = univ) : t = univ :=
eq_univ_of_univ_subset <| (hs ▸ h : univ ⊆ t)
#align set.eq_univ_of_subset Set.eq_univ_of_subset
theorem exists_mem_of_nonempty (α) : ∀ [Nonempty α], ∃ x : α, x ∈ (univ : Set α)
| ⟨x⟩ => ⟨x, trivial⟩
#align set.exists_mem_of_nonempty Set.exists_mem_of_nonempty
theorem ne_univ_iff_exists_not_mem {α : Type*} (s : Set α) : s ≠ univ ↔ ∃ a, a ∉ s := by
rw [← not_forall, ← eq_univ_iff_forall]
#align set.ne_univ_iff_exists_not_mem Set.ne_univ_iff_exists_not_mem
theorem not_subset_iff_exists_mem_not_mem {α : Type*} {s t : Set α} :
¬s ⊆ t ↔ ∃ x, x ∈ s ∧ x ∉ t := by simp [subset_def]
#align set.not_subset_iff_exists_mem_not_mem Set.not_subset_iff_exists_mem_not_mem
theorem univ_unique [Unique α] : @Set.univ α = {default} :=
Set.ext fun x => iff_of_true trivial <| Subsingleton.elim x default
#align set.univ_unique Set.univ_unique
theorem ssubset_univ_iff : s ⊂ univ ↔ s ≠ univ :=
lt_top_iff_ne_top
#align set.ssubset_univ_iff Set.ssubset_univ_iff
instance nontrivial_of_nonempty [Nonempty α] : Nontrivial (Set α) :=
⟨⟨∅, univ, empty_ne_univ⟩⟩
#align set.nontrivial_of_nonempty Set.nontrivial_of_nonempty
theorem union_def {s₁ s₂ : Set α} : s₁ ∪ s₂ = { a | a ∈ s₁ ∨ a ∈ s₂ } :=
rfl
#align set.union_def Set.union_def
theorem mem_union_left {x : α} {a : Set α} (b : Set α) : x ∈ a → x ∈ a ∪ b :=
Or.inl
#align set.mem_union_left Set.mem_union_left
theorem mem_union_right {x : α} {b : Set α} (a : Set α) : x ∈ b → x ∈ a ∪ b :=
Or.inr
#align set.mem_union_right Set.mem_union_right
theorem mem_or_mem_of_mem_union {x : α} {a b : Set α} (H : x ∈ a ∪ b) : x ∈ a ∨ x ∈ b :=
H
#align set.mem_or_mem_of_mem_union Set.mem_or_mem_of_mem_union
theorem MemUnion.elim {x : α} {a b : Set α} {P : Prop} (H₁ : x ∈ a ∪ b) (H₂ : x ∈ a → P)
(H₃ : x ∈ b → P) : P :=
Or.elim H₁ H₂ H₃
#align set.mem_union.elim Set.MemUnion.elim
@[simp]
theorem mem_union (x : α) (a b : Set α) : x ∈ a ∪ b ↔ x ∈ a ∨ x ∈ b :=
Iff.rfl
#align set.mem_union Set.mem_union
@[simp]
theorem union_self (a : Set α) : a ∪ a = a :=
ext fun _ => or_self_iff
#align set.union_self Set.union_self
@[simp]
theorem union_empty (a : Set α) : a ∪ ∅ = a :=
ext fun _ => or_false_iff _
#align set.union_empty Set.union_empty
@[simp]
theorem empty_union (a : Set α) : ∅ ∪ a = a :=
ext fun _ => false_or_iff _
#align set.empty_union Set.empty_union
theorem union_comm (a b : Set α) : a ∪ b = b ∪ a :=
ext fun _ => or_comm
#align set.union_comm Set.union_comm
theorem union_assoc (a b c : Set α) : a ∪ b ∪ c = a ∪ (b ∪ c) :=
ext fun _ => or_assoc
#align set.union_assoc Set.union_assoc
instance union_isAssoc : Std.Associative (α := Set α) (· ∪ ·) :=
⟨union_assoc⟩
#align set.union_is_assoc Set.union_isAssoc
instance union_isComm : Std.Commutative (α := Set α) (· ∪ ·) :=
⟨union_comm⟩
#align set.union_is_comm Set.union_isComm
theorem union_left_comm (s₁ s₂ s₃ : Set α) : s₁ ∪ (s₂ ∪ s₃) = s₂ ∪ (s₁ ∪ s₃) :=
ext fun _ => or_left_comm
#align set.union_left_comm Set.union_left_comm
theorem union_right_comm (s₁ s₂ s₃ : Set α) : s₁ ∪ s₂ ∪ s₃ = s₁ ∪ s₃ ∪ s₂ :=
ext fun _ => or_right_comm
#align set.union_right_comm Set.union_right_comm
@[simp]
theorem union_eq_left {s t : Set α} : s ∪ t = s ↔ t ⊆ s :=
sup_eq_left
#align set.union_eq_left_iff_subset Set.union_eq_left
@[simp]
theorem union_eq_right {s t : Set α} : s ∪ t = t ↔ s ⊆ t :=
sup_eq_right
#align set.union_eq_right_iff_subset Set.union_eq_right
theorem union_eq_self_of_subset_left {s t : Set α} (h : s ⊆ t) : s ∪ t = t :=
union_eq_right.mpr h
#align set.union_eq_self_of_subset_left Set.union_eq_self_of_subset_left
theorem union_eq_self_of_subset_right {s t : Set α} (h : t ⊆ s) : s ∪ t = s :=
union_eq_left.mpr h
#align set.union_eq_self_of_subset_right Set.union_eq_self_of_subset_right
@[simp]
theorem subset_union_left {s t : Set α} : s ⊆ s ∪ t := fun _ => Or.inl
#align set.subset_union_left Set.subset_union_left
@[simp]
theorem subset_union_right {s t : Set α} : t ⊆ s ∪ t := fun _ => Or.inr
#align set.subset_union_right Set.subset_union_right
theorem union_subset {s t r : Set α} (sr : s ⊆ r) (tr : t ⊆ r) : s ∪ t ⊆ r := fun _ =>
Or.rec (@sr _) (@tr _)
#align set.union_subset Set.union_subset
@[simp]
theorem union_subset_iff {s t u : Set α} : s ∪ t ⊆ u ↔ s ⊆ u ∧ t ⊆ u :=
(forall_congr' fun _ => or_imp).trans forall_and
#align set.union_subset_iff Set.union_subset_iff
@[gcongr]
theorem union_subset_union {s₁ s₂ t₁ t₂ : Set α} (h₁ : s₁ ⊆ s₂) (h₂ : t₁ ⊆ t₂) :
s₁ ∪ t₁ ⊆ s₂ ∪ t₂ := fun _ => Or.imp (@h₁ _) (@h₂ _)
#align set.union_subset_union Set.union_subset_union
@[gcongr]
theorem union_subset_union_left {s₁ s₂ : Set α} (t) (h : s₁ ⊆ s₂) : s₁ ∪ t ⊆ s₂ ∪ t :=
union_subset_union h Subset.rfl
#align set.union_subset_union_left Set.union_subset_union_left
@[gcongr]
theorem union_subset_union_right (s) {t₁ t₂ : Set α} (h : t₁ ⊆ t₂) : s ∪ t₁ ⊆ s ∪ t₂ :=
union_subset_union Subset.rfl h
#align set.union_subset_union_right Set.union_subset_union_right
theorem subset_union_of_subset_left {s t : Set α} (h : s ⊆ t) (u : Set α) : s ⊆ t ∪ u :=
h.trans subset_union_left
#align set.subset_union_of_subset_left Set.subset_union_of_subset_left
theorem subset_union_of_subset_right {s u : Set α} (h : s ⊆ u) (t : Set α) : s ⊆ t ∪ u :=
h.trans subset_union_right
#align set.subset_union_of_subset_right Set.subset_union_of_subset_right
-- Porting note: replaced `⊔` in RHS
theorem union_congr_left (ht : t ⊆ s ∪ u) (hu : u ⊆ s ∪ t) : s ∪ t = s ∪ u :=
sup_congr_left ht hu
#align set.union_congr_left Set.union_congr_left
theorem union_congr_right (hs : s ⊆ t ∪ u) (ht : t ⊆ s ∪ u) : s ∪ u = t ∪ u :=
sup_congr_right hs ht
#align set.union_congr_right Set.union_congr_right
theorem union_eq_union_iff_left : s ∪ t = s ∪ u ↔ t ⊆ s ∪ u ∧ u ⊆ s ∪ t :=
sup_eq_sup_iff_left
#align set.union_eq_union_iff_left Set.union_eq_union_iff_left
theorem union_eq_union_iff_right : s ∪ u = t ∪ u ↔ s ⊆ t ∪ u ∧ t ⊆ s ∪ u :=
sup_eq_sup_iff_right
#align set.union_eq_union_iff_right Set.union_eq_union_iff_right
@[simp]
theorem union_empty_iff {s t : Set α} : s ∪ t = ∅ ↔ s = ∅ ∧ t = ∅ := by
simp only [← subset_empty_iff]
exact union_subset_iff
#align set.union_empty_iff Set.union_empty_iff
@[simp]
theorem union_univ (s : Set α) : s ∪ univ = univ := sup_top_eq _
#align set.union_univ Set.union_univ
@[simp]
theorem univ_union (s : Set α) : univ ∪ s = univ := top_sup_eq _
#align set.univ_union Set.univ_union
theorem inter_def {s₁ s₂ : Set α} : s₁ ∩ s₂ = { a | a ∈ s₁ ∧ a ∈ s₂ } :=
rfl
#align set.inter_def Set.inter_def
@[simp, mfld_simps]
theorem mem_inter_iff (x : α) (a b : Set α) : x ∈ a ∩ b ↔ x ∈ a ∧ x ∈ b :=
Iff.rfl
#align set.mem_inter_iff Set.mem_inter_iff
theorem mem_inter {x : α} {a b : Set α} (ha : x ∈ a) (hb : x ∈ b) : x ∈ a ∩ b :=
⟨ha, hb⟩
#align set.mem_inter Set.mem_inter
theorem mem_of_mem_inter_left {x : α} {a b : Set α} (h : x ∈ a ∩ b) : x ∈ a :=
h.left
#align set.mem_of_mem_inter_left Set.mem_of_mem_inter_left
theorem mem_of_mem_inter_right {x : α} {a b : Set α} (h : x ∈ a ∩ b) : x ∈ b :=
h.right
#align set.mem_of_mem_inter_right Set.mem_of_mem_inter_right
@[simp]
theorem inter_self (a : Set α) : a ∩ a = a :=
ext fun _ => and_self_iff
#align set.inter_self Set.inter_self
@[simp]
theorem inter_empty (a : Set α) : a ∩ ∅ = ∅ :=
ext fun _ => and_false_iff _
#align set.inter_empty Set.inter_empty
@[simp]
theorem empty_inter (a : Set α) : ∅ ∩ a = ∅ :=
ext fun _ => false_and_iff _
#align set.empty_inter Set.empty_inter
theorem inter_comm (a b : Set α) : a ∩ b = b ∩ a :=
ext fun _ => and_comm
#align set.inter_comm Set.inter_comm
theorem inter_assoc (a b c : Set α) : a ∩ b ∩ c = a ∩ (b ∩ c) :=
ext fun _ => and_assoc
#align set.inter_assoc Set.inter_assoc
instance inter_isAssoc : Std.Associative (α := Set α) (· ∩ ·) :=
⟨inter_assoc⟩
#align set.inter_is_assoc Set.inter_isAssoc
instance inter_isComm : Std.Commutative (α := Set α) (· ∩ ·) :=
⟨inter_comm⟩
#align set.inter_is_comm Set.inter_isComm
theorem inter_left_comm (s₁ s₂ s₃ : Set α) : s₁ ∩ (s₂ ∩ s₃) = s₂ ∩ (s₁ ∩ s₃) :=
ext fun _ => and_left_comm
#align set.inter_left_comm Set.inter_left_comm
theorem inter_right_comm (s₁ s₂ s₃ : Set α) : s₁ ∩ s₂ ∩ s₃ = s₁ ∩ s₃ ∩ s₂ :=
ext fun _ => and_right_comm
#align set.inter_right_comm Set.inter_right_comm
@[simp, mfld_simps]
theorem inter_subset_left {s t : Set α} : s ∩ t ⊆ s := fun _ => And.left
#align set.inter_subset_left Set.inter_subset_left
@[simp]
theorem inter_subset_right {s t : Set α} : s ∩ t ⊆ t := fun _ => And.right
#align set.inter_subset_right Set.inter_subset_right
theorem subset_inter {s t r : Set α} (rs : r ⊆ s) (rt : r ⊆ t) : r ⊆ s ∩ t := fun _ h =>
⟨rs h, rt h⟩
#align set.subset_inter Set.subset_inter
@[simp]
theorem subset_inter_iff {s t r : Set α} : r ⊆ s ∩ t ↔ r ⊆ s ∧ r ⊆ t :=
(forall_congr' fun _ => imp_and).trans forall_and
#align set.subset_inter_iff Set.subset_inter_iff
@[simp] lemma inter_eq_left : s ∩ t = s ↔ s ⊆ t := inf_eq_left
#align set.inter_eq_left_iff_subset Set.inter_eq_left
@[simp] lemma inter_eq_right : s ∩ t = t ↔ t ⊆ s := inf_eq_right
#align set.inter_eq_right_iff_subset Set.inter_eq_right
@[simp] lemma left_eq_inter : s = s ∩ t ↔ s ⊆ t := left_eq_inf
@[simp] lemma right_eq_inter : t = s ∩ t ↔ t ⊆ s := right_eq_inf
theorem inter_eq_self_of_subset_left {s t : Set α} : s ⊆ t → s ∩ t = s :=
inter_eq_left.mpr
#align set.inter_eq_self_of_subset_left Set.inter_eq_self_of_subset_left
theorem inter_eq_self_of_subset_right {s t : Set α} : t ⊆ s → s ∩ t = t :=
inter_eq_right.mpr
#align set.inter_eq_self_of_subset_right Set.inter_eq_self_of_subset_right
theorem inter_congr_left (ht : s ∩ u ⊆ t) (hu : s ∩ t ⊆ u) : s ∩ t = s ∩ u :=
inf_congr_left ht hu
#align set.inter_congr_left Set.inter_congr_left
theorem inter_congr_right (hs : t ∩ u ⊆ s) (ht : s ∩ u ⊆ t) : s ∩ u = t ∩ u :=
inf_congr_right hs ht
#align set.inter_congr_right Set.inter_congr_right
theorem inter_eq_inter_iff_left : s ∩ t = s ∩ u ↔ s ∩ u ⊆ t ∧ s ∩ t ⊆ u :=
inf_eq_inf_iff_left
#align set.inter_eq_inter_iff_left Set.inter_eq_inter_iff_left
theorem inter_eq_inter_iff_right : s ∩ u = t ∩ u ↔ t ∩ u ⊆ s ∧ s ∩ u ⊆ t :=
inf_eq_inf_iff_right
#align set.inter_eq_inter_iff_right Set.inter_eq_inter_iff_right
@[simp, mfld_simps]
theorem inter_univ (a : Set α) : a ∩ univ = a := inf_top_eq _
#align set.inter_univ Set.inter_univ
@[simp, mfld_simps]
theorem univ_inter (a : Set α) : univ ∩ a = a := top_inf_eq _
#align set.univ_inter Set.univ_inter
@[gcongr]
theorem inter_subset_inter {s₁ s₂ t₁ t₂ : Set α} (h₁ : s₁ ⊆ t₁) (h₂ : s₂ ⊆ t₂) :
s₁ ∩ s₂ ⊆ t₁ ∩ t₂ := fun _ => And.imp (@h₁ _) (@h₂ _)
#align set.inter_subset_inter Set.inter_subset_inter
@[gcongr]
theorem inter_subset_inter_left {s t : Set α} (u : Set α) (H : s ⊆ t) : s ∩ u ⊆ t ∩ u :=
inter_subset_inter H Subset.rfl
#align set.inter_subset_inter_left Set.inter_subset_inter_left
@[gcongr]
theorem inter_subset_inter_right {s t : Set α} (u : Set α) (H : s ⊆ t) : u ∩ s ⊆ u ∩ t :=
inter_subset_inter Subset.rfl H
#align set.inter_subset_inter_right Set.inter_subset_inter_right
theorem union_inter_cancel_left {s t : Set α} : (s ∪ t) ∩ s = s :=
inter_eq_self_of_subset_right subset_union_left
#align set.union_inter_cancel_left Set.union_inter_cancel_left
theorem union_inter_cancel_right {s t : Set α} : (s ∪ t) ∩ t = t :=
inter_eq_self_of_subset_right subset_union_right
#align set.union_inter_cancel_right Set.union_inter_cancel_right
theorem inter_setOf_eq_sep (s : Set α) (p : α → Prop) : s ∩ {a | p a} = {a ∈ s | p a} :=
rfl
#align set.inter_set_of_eq_sep Set.inter_setOf_eq_sep
theorem setOf_inter_eq_sep (p : α → Prop) (s : Set α) : {a | p a} ∩ s = {a ∈ s | p a} :=
inter_comm _ _
#align set.set_of_inter_eq_sep Set.setOf_inter_eq_sep
theorem inter_union_distrib_left (s t u : Set α) : s ∩ (t ∪ u) = s ∩ t ∪ s ∩ u :=
inf_sup_left _ _ _
#align set.inter_distrib_left Set.inter_union_distrib_left
theorem union_inter_distrib_right (s t u : Set α) : (s ∪ t) ∩ u = s ∩ u ∪ t ∩ u :=
inf_sup_right _ _ _
#align set.inter_distrib_right Set.union_inter_distrib_right
theorem union_inter_distrib_left (s t u : Set α) : s ∪ t ∩ u = (s ∪ t) ∩ (s ∪ u) :=
sup_inf_left _ _ _
#align set.union_distrib_left Set.union_inter_distrib_left
theorem inter_union_distrib_right (s t u : Set α) : s ∩ t ∪ u = (s ∪ u) ∩ (t ∪ u) :=
sup_inf_right _ _ _
#align set.union_distrib_right Set.inter_union_distrib_right
-- 2024-03-22
@[deprecated] alias inter_distrib_left := inter_union_distrib_left
@[deprecated] alias inter_distrib_right := union_inter_distrib_right
@[deprecated] alias union_distrib_left := union_inter_distrib_left
@[deprecated] alias union_distrib_right := inter_union_distrib_right
theorem union_union_distrib_left (s t u : Set α) : s ∪ (t ∪ u) = s ∪ t ∪ (s ∪ u) :=
sup_sup_distrib_left _ _ _
#align set.union_union_distrib_left Set.union_union_distrib_left
theorem union_union_distrib_right (s t u : Set α) : s ∪ t ∪ u = s ∪ u ∪ (t ∪ u) :=
sup_sup_distrib_right _ _ _
#align set.union_union_distrib_right Set.union_union_distrib_right
theorem inter_inter_distrib_left (s t u : Set α) : s ∩ (t ∩ u) = s ∩ t ∩ (s ∩ u) :=
inf_inf_distrib_left _ _ _
#align set.inter_inter_distrib_left Set.inter_inter_distrib_left
theorem inter_inter_distrib_right (s t u : Set α) : s ∩ t ∩ u = s ∩ u ∩ (t ∩ u) :=
inf_inf_distrib_right _ _ _
#align set.inter_inter_distrib_right Set.inter_inter_distrib_right
theorem union_union_union_comm (s t u v : Set α) : s ∪ t ∪ (u ∪ v) = s ∪ u ∪ (t ∪ v) :=
sup_sup_sup_comm _ _ _ _
#align set.union_union_union_comm Set.union_union_union_comm
theorem inter_inter_inter_comm (s t u v : Set α) : s ∩ t ∩ (u ∩ v) = s ∩ u ∩ (t ∩ v) :=
inf_inf_inf_comm _ _ _ _
#align set.inter_inter_inter_comm Set.inter_inter_inter_comm
theorem insert_def (x : α) (s : Set α) : insert x s = { y | y = x ∨ y ∈ s } :=
rfl
#align set.insert_def Set.insert_def
@[simp]
theorem subset_insert (x : α) (s : Set α) : s ⊆ insert x s := fun _ => Or.inr
#align set.subset_insert Set.subset_insert
theorem mem_insert (x : α) (s : Set α) : x ∈ insert x s :=
Or.inl rfl
#align set.mem_insert Set.mem_insert
theorem mem_insert_of_mem {x : α} {s : Set α} (y : α) : x ∈ s → x ∈ insert y s :=
Or.inr
#align set.mem_insert_of_mem Set.mem_insert_of_mem
theorem eq_or_mem_of_mem_insert {x a : α} {s : Set α} : x ∈ insert a s → x = a ∨ x ∈ s :=
id
#align set.eq_or_mem_of_mem_insert Set.eq_or_mem_of_mem_insert
theorem mem_of_mem_insert_of_ne : b ∈ insert a s → b ≠ a → b ∈ s :=
Or.resolve_left
#align set.mem_of_mem_insert_of_ne Set.mem_of_mem_insert_of_ne
theorem eq_of_not_mem_of_mem_insert : b ∈ insert a s → b ∉ s → b = a :=
Or.resolve_right
#align set.eq_of_not_mem_of_mem_insert Set.eq_of_not_mem_of_mem_insert
@[simp]
theorem mem_insert_iff {x a : α} {s : Set α} : x ∈ insert a s ↔ x = a ∨ x ∈ s :=
Iff.rfl
#align set.mem_insert_iff Set.mem_insert_iff
@[simp]
theorem insert_eq_of_mem {a : α} {s : Set α} (h : a ∈ s) : insert a s = s :=
ext fun _ => or_iff_right_of_imp fun e => e.symm ▸ h
#align set.insert_eq_of_mem Set.insert_eq_of_mem
theorem ne_insert_of_not_mem {s : Set α} (t : Set α) {a : α} : a ∉ s → s ≠ insert a t :=
mt fun e => e.symm ▸ mem_insert _ _
#align set.ne_insert_of_not_mem Set.ne_insert_of_not_mem
@[simp]
theorem insert_eq_self : insert a s = s ↔ a ∈ s :=
⟨fun h => h ▸ mem_insert _ _, insert_eq_of_mem⟩
#align set.insert_eq_self Set.insert_eq_self
theorem insert_ne_self : insert a s ≠ s ↔ a ∉ s :=
insert_eq_self.not
#align set.insert_ne_self Set.insert_ne_self
theorem insert_subset_iff : insert a s ⊆ t ↔ a ∈ t ∧ s ⊆ t := by
simp only [subset_def, mem_insert_iff, or_imp, forall_and, forall_eq]
#align set.insert_subset Set.insert_subset_iff
theorem insert_subset (ha : a ∈ t) (hs : s ⊆ t) : insert a s ⊆ t :=
insert_subset_iff.mpr ⟨ha, hs⟩
theorem insert_subset_insert (h : s ⊆ t) : insert a s ⊆ insert a t := fun _ => Or.imp_right (@h _)
#align set.insert_subset_insert Set.insert_subset_insert
@[simp] theorem insert_subset_insert_iff (ha : a ∉ s) : insert a s ⊆ insert a t ↔ s ⊆ t := by
refine ⟨fun h x hx => ?_, insert_subset_insert⟩
rcases h (subset_insert _ _ hx) with (rfl | hxt)
exacts [(ha hx).elim, hxt]
#align set.insert_subset_insert_iff Set.insert_subset_insert_iff
theorem subset_insert_iff_of_not_mem (ha : a ∉ s) : s ⊆ insert a t ↔ s ⊆ t :=
forall₂_congr fun _ hb => or_iff_right <| ne_of_mem_of_not_mem hb ha
#align set.subset_insert_iff_of_not_mem Set.subset_insert_iff_of_not_mem
theorem ssubset_iff_insert {s t : Set α} : s ⊂ t ↔ ∃ a ∉ s, insert a s ⊆ t := by
simp only [insert_subset_iff, exists_and_right, ssubset_def, not_subset]
aesop
#align set.ssubset_iff_insert Set.ssubset_iff_insert
theorem ssubset_insert {s : Set α} {a : α} (h : a ∉ s) : s ⊂ insert a s :=
ssubset_iff_insert.2 ⟨a, h, Subset.rfl⟩
#align set.ssubset_insert Set.ssubset_insert
theorem insert_comm (a b : α) (s : Set α) : insert a (insert b s) = insert b (insert a s) :=
ext fun _ => or_left_comm
#align set.insert_comm Set.insert_comm
-- Porting note (#10618): removing `simp` attribute because `simp` can prove it
theorem insert_idem (a : α) (s : Set α) : insert a (insert a s) = insert a s :=
insert_eq_of_mem <| mem_insert _ _
#align set.insert_idem Set.insert_idem
theorem insert_union : insert a s ∪ t = insert a (s ∪ t) :=
ext fun _ => or_assoc
#align set.insert_union Set.insert_union
@[simp]
theorem union_insert : s ∪ insert a t = insert a (s ∪ t) :=
ext fun _ => or_left_comm
#align set.union_insert Set.union_insert
@[simp]
theorem insert_nonempty (a : α) (s : Set α) : (insert a s).Nonempty :=
⟨a, mem_insert a s⟩
#align set.insert_nonempty Set.insert_nonempty
instance (a : α) (s : Set α) : Nonempty (insert a s : Set α) :=
(insert_nonempty a s).to_subtype
theorem insert_inter_distrib (a : α) (s t : Set α) : insert a (s ∩ t) = insert a s ∩ insert a t :=
ext fun _ => or_and_left
#align set.insert_inter_distrib Set.insert_inter_distrib
theorem insert_union_distrib (a : α) (s t : Set α) : insert a (s ∪ t) = insert a s ∪ insert a t :=
ext fun _ => or_or_distrib_left
#align set.insert_union_distrib Set.insert_union_distrib
theorem insert_inj (ha : a ∉ s) : insert a s = insert b s ↔ a = b :=
⟨fun h => eq_of_not_mem_of_mem_insert (h.subst <| mem_insert a s) ha,
congr_arg (fun x => insert x s)⟩
#align set.insert_inj Set.insert_inj
-- useful in proofs by induction
theorem forall_of_forall_insert {P : α → Prop} {a : α} {s : Set α} (H : ∀ x, x ∈ insert a s → P x)
(x) (h : x ∈ s) : P x :=
H _ (Or.inr h)
#align set.forall_of_forall_insert Set.forall_of_forall_insert
theorem forall_insert_of_forall {P : α → Prop} {a : α} {s : Set α} (H : ∀ x, x ∈ s → P x) (ha : P a)
(x) (h : x ∈ insert a s) : P x :=
h.elim (fun e => e.symm ▸ ha) (H _)
#align set.forall_insert_of_forall Set.forall_insert_of_forall
theorem exists_mem_insert {P : α → Prop} {a : α} {s : Set α} :
(∃ x ∈ insert a s, P x) ↔ (P a ∨ ∃ x ∈ s, P x) := by
simp [mem_insert_iff, or_and_right, exists_and_left, exists_or]
#align set.bex_insert_iff Set.exists_mem_insert
@[deprecated (since := "2024-03-23")] alias bex_insert_iff := exists_mem_insert
theorem forall_mem_insert {P : α → Prop} {a : α} {s : Set α} :
(∀ x ∈ insert a s, P x) ↔ P a ∧ ∀ x ∈ s, P x :=
forall₂_or_left.trans <| and_congr_left' forall_eq
#align set.ball_insert_iff Set.forall_mem_insert
@[deprecated (since := "2024-03-23")] alias ball_insert_iff := forall_mem_insert
instance : LawfulSingleton α (Set α) :=
⟨fun x => Set.ext fun a => by
simp only [mem_empty_iff_false, mem_insert_iff, or_false]
exact Iff.rfl⟩
theorem singleton_def (a : α) : ({a} : Set α) = insert a ∅ :=
(insert_emptyc_eq a).symm
#align set.singleton_def Set.singleton_def
@[simp]
theorem mem_singleton_iff {a b : α} : a ∈ ({b} : Set α) ↔ a = b :=
Iff.rfl
#align set.mem_singleton_iff Set.mem_singleton_iff
@[simp]
theorem setOf_eq_eq_singleton {a : α} : { n | n = a } = {a} :=
rfl
#align set.set_of_eq_eq_singleton Set.setOf_eq_eq_singleton
@[simp]
theorem setOf_eq_eq_singleton' {a : α} : { x | a = x } = {a} :=
ext fun _ => eq_comm
#align set.set_of_eq_eq_singleton' Set.setOf_eq_eq_singleton'
-- TODO: again, annotation needed
--Porting note (#11119): removed `simp` attribute
theorem mem_singleton (a : α) : a ∈ ({a} : Set α) :=
@rfl _ _
#align set.mem_singleton Set.mem_singleton
theorem eq_of_mem_singleton {x y : α} (h : x ∈ ({y} : Set α)) : x = y :=
h
#align set.eq_of_mem_singleton Set.eq_of_mem_singleton
@[simp]
theorem singleton_eq_singleton_iff {x y : α} : {x} = ({y} : Set α) ↔ x = y :=
ext_iff.trans eq_iff_eq_cancel_left
#align set.singleton_eq_singleton_iff Set.singleton_eq_singleton_iff
theorem singleton_injective : Injective (singleton : α → Set α) := fun _ _ =>
singleton_eq_singleton_iff.mp
#align set.singleton_injective Set.singleton_injective
theorem mem_singleton_of_eq {x y : α} (H : x = y) : x ∈ ({y} : Set α) :=
H
#align set.mem_singleton_of_eq Set.mem_singleton_of_eq
theorem insert_eq (x : α) (s : Set α) : insert x s = ({x} : Set α) ∪ s :=
rfl
#align set.insert_eq Set.insert_eq
@[simp]
theorem singleton_nonempty (a : α) : ({a} : Set α).Nonempty :=
⟨a, rfl⟩
#align set.singleton_nonempty Set.singleton_nonempty
@[simp]
theorem singleton_ne_empty (a : α) : ({a} : Set α) ≠ ∅ :=
(singleton_nonempty _).ne_empty
#align set.singleton_ne_empty Set.singleton_ne_empty
--Porting note (#10618): removed `simp` attribute because `simp` can prove it
theorem empty_ssubset_singleton : (∅ : Set α) ⊂ {a} :=
(singleton_nonempty _).empty_ssubset
#align set.empty_ssubset_singleton Set.empty_ssubset_singleton
@[simp]
theorem singleton_subset_iff {a : α} {s : Set α} : {a} ⊆ s ↔ a ∈ s :=
forall_eq
#align set.singleton_subset_iff Set.singleton_subset_iff
theorem singleton_subset_singleton : ({a} : Set α) ⊆ {b} ↔ a = b := by simp
#align set.singleton_subset_singleton Set.singleton_subset_singleton
theorem set_compr_eq_eq_singleton {a : α} : { b | b = a } = {a} :=
rfl
#align set.set_compr_eq_eq_singleton Set.set_compr_eq_eq_singleton
@[simp]
theorem singleton_union : {a} ∪ s = insert a s :=
rfl
#align set.singleton_union Set.singleton_union
@[simp]
theorem union_singleton : s ∪ {a} = insert a s :=
union_comm _ _
#align set.union_singleton Set.union_singleton
@[simp]
theorem singleton_inter_nonempty : ({a} ∩ s).Nonempty ↔ a ∈ s := by
simp only [Set.Nonempty, mem_inter_iff, mem_singleton_iff, exists_eq_left]
#align set.singleton_inter_nonempty Set.singleton_inter_nonempty
@[simp]
theorem inter_singleton_nonempty : (s ∩ {a}).Nonempty ↔ a ∈ s := by
rw [inter_comm, singleton_inter_nonempty]
#align set.inter_singleton_nonempty Set.inter_singleton_nonempty
@[simp]
theorem singleton_inter_eq_empty : {a} ∩ s = ∅ ↔ a ∉ s :=
not_nonempty_iff_eq_empty.symm.trans singleton_inter_nonempty.not
#align set.singleton_inter_eq_empty Set.singleton_inter_eq_empty
@[simp]
theorem inter_singleton_eq_empty : s ∩ {a} = ∅ ↔ a ∉ s := by
rw [inter_comm, singleton_inter_eq_empty]
#align set.inter_singleton_eq_empty Set.inter_singleton_eq_empty
theorem nmem_singleton_empty {s : Set α} : s ∉ ({∅} : Set (Set α)) ↔ s.Nonempty :=
nonempty_iff_ne_empty.symm
#align set.nmem_singleton_empty Set.nmem_singleton_empty
instance uniqueSingleton (a : α) : Unique (↥({a} : Set α)) :=
⟨⟨⟨a, mem_singleton a⟩⟩, fun ⟨_, h⟩ => Subtype.eq h⟩
#align set.unique_singleton Set.uniqueSingleton
theorem eq_singleton_iff_unique_mem : s = {a} ↔ a ∈ s ∧ ∀ x ∈ s, x = a :=
Subset.antisymm_iff.trans <| and_comm.trans <| and_congr_left' singleton_subset_iff
#align set.eq_singleton_iff_unique_mem Set.eq_singleton_iff_unique_mem
theorem eq_singleton_iff_nonempty_unique_mem : s = {a} ↔ s.Nonempty ∧ ∀ x ∈ s, x = a :=
eq_singleton_iff_unique_mem.trans <|
and_congr_left fun H => ⟨fun h' => ⟨_, h'⟩, fun ⟨x, h⟩ => H x h ▸ h⟩
#align set.eq_singleton_iff_nonempty_unique_mem Set.eq_singleton_iff_nonempty_unique_mem
set_option backward.synthInstance.canonInstances false in -- See https://github.com/leanprover-community/mathlib4/issues/12532
-- while `simp` is capable of proving this, it is not capable of turning the LHS into the RHS.
@[simp]
theorem default_coe_singleton (x : α) : (default : ({x} : Set α)) = ⟨x, rfl⟩ :=
rfl
#align set.default_coe_singleton Set.default_coe_singleton
@[simp]
theorem subset_singleton_iff {α : Type*} {s : Set α} {x : α} : s ⊆ {x} ↔ ∀ y ∈ s, y = x :=
Iff.rfl
#align set.subset_singleton_iff Set.subset_singleton_iff
theorem subset_singleton_iff_eq {s : Set α} {x : α} : s ⊆ {x} ↔ s = ∅ ∨ s = {x} := by
obtain rfl | hs := s.eq_empty_or_nonempty
· exact ⟨fun _ => Or.inl rfl, fun _ => empty_subset _⟩
· simp [eq_singleton_iff_nonempty_unique_mem, hs, hs.ne_empty]
#align set.subset_singleton_iff_eq Set.subset_singleton_iff_eq
theorem Nonempty.subset_singleton_iff (h : s.Nonempty) : s ⊆ {a} ↔ s = {a} :=
subset_singleton_iff_eq.trans <| or_iff_right h.ne_empty
#align set.nonempty.subset_singleton_iff Set.Nonempty.subset_singleton_iff
theorem ssubset_singleton_iff {s : Set α} {x : α} : s ⊂ {x} ↔ s = ∅ := by
rw [ssubset_iff_subset_ne, subset_singleton_iff_eq, or_and_right, and_not_self_iff, or_false_iff,
and_iff_left_iff_imp]
exact fun h => h ▸ (singleton_ne_empty _).symm
#align set.ssubset_singleton_iff Set.ssubset_singleton_iff
theorem eq_empty_of_ssubset_singleton {s : Set α} {x : α} (hs : s ⊂ {x}) : s = ∅ :=
ssubset_singleton_iff.1 hs
#align set.eq_empty_of_ssubset_singleton Set.eq_empty_of_ssubset_singleton
theorem eq_of_nonempty_of_subsingleton {α} [Subsingleton α] (s t : Set α) [Nonempty s]
[Nonempty t] : s = t :=
nonempty_of_nonempty_subtype.eq_univ.trans nonempty_of_nonempty_subtype.eq_univ.symm
theorem eq_of_nonempty_of_subsingleton' {α} [Subsingleton α] {s : Set α} (t : Set α)
(hs : s.Nonempty) [Nonempty t] : s = t :=
have := hs.to_subtype; eq_of_nonempty_of_subsingleton s t
set_option backward.synthInstance.canonInstances false in -- See https://github.com/leanprover-community/mathlib4/issues/12532
theorem Nonempty.eq_zero [Subsingleton α] [Zero α] {s : Set α} (h : s.Nonempty) :
s = {0} := eq_of_nonempty_of_subsingleton' {0} h
set_option backward.synthInstance.canonInstances false in -- See https://github.com/leanprover-community/mathlib4/issues/12532
theorem Nonempty.eq_one [Subsingleton α] [One α] {s : Set α} (h : s.Nonempty) :
s = {1} := eq_of_nonempty_of_subsingleton' {1} h
protected theorem disjoint_iff : Disjoint s t ↔ s ∩ t ⊆ ∅ :=
disjoint_iff_inf_le
#align set.disjoint_iff Set.disjoint_iff
theorem disjoint_iff_inter_eq_empty : Disjoint s t ↔ s ∩ t = ∅ :=
disjoint_iff
#align set.disjoint_iff_inter_eq_empty Set.disjoint_iff_inter_eq_empty
theorem _root_.Disjoint.inter_eq : Disjoint s t → s ∩ t = ∅ :=
Disjoint.eq_bot
#align disjoint.inter_eq Disjoint.inter_eq
theorem disjoint_left : Disjoint s t ↔ ∀ ⦃a⦄, a ∈ s → a ∉ t :=
disjoint_iff_inf_le.trans <| forall_congr' fun _ => not_and
#align set.disjoint_left Set.disjoint_left
theorem disjoint_right : Disjoint s t ↔ ∀ ⦃a⦄, a ∈ t → a ∉ s := by rw [disjoint_comm, disjoint_left]
#align set.disjoint_right Set.disjoint_right
lemma not_disjoint_iff : ¬Disjoint s t ↔ ∃ x, x ∈ s ∧ x ∈ t :=
Set.disjoint_iff.not.trans <| not_forall.trans <| exists_congr fun _ ↦ not_not
#align set.not_disjoint_iff Set.not_disjoint_iff
lemma not_disjoint_iff_nonempty_inter : ¬ Disjoint s t ↔ (s ∩ t).Nonempty := not_disjoint_iff
#align set.not_disjoint_iff_nonempty_inter Set.not_disjoint_iff_nonempty_inter
alias ⟨_, Nonempty.not_disjoint⟩ := not_disjoint_iff_nonempty_inter
#align set.nonempty.not_disjoint Set.Nonempty.not_disjoint
lemma disjoint_or_nonempty_inter (s t : Set α) : Disjoint s t ∨ (s ∩ t).Nonempty :=
(em _).imp_right not_disjoint_iff_nonempty_inter.1
#align set.disjoint_or_nonempty_inter Set.disjoint_or_nonempty_inter
lemma disjoint_iff_forall_ne : Disjoint s t ↔ ∀ ⦃a⦄, a ∈ s → ∀ ⦃b⦄, b ∈ t → a ≠ b := by
simp only [Ne, disjoint_left, @imp_not_comm _ (_ = _), forall_eq']
#align set.disjoint_iff_forall_ne Set.disjoint_iff_forall_ne
alias ⟨_root_.Disjoint.ne_of_mem, _⟩ := disjoint_iff_forall_ne
#align disjoint.ne_of_mem Disjoint.ne_of_mem
lemma disjoint_of_subset_left (h : s ⊆ u) (d : Disjoint u t) : Disjoint s t := d.mono_left h
#align set.disjoint_of_subset_left Set.disjoint_of_subset_left
lemma disjoint_of_subset_right (h : t ⊆ u) (d : Disjoint s u) : Disjoint s t := d.mono_right h
#align set.disjoint_of_subset_right Set.disjoint_of_subset_right
lemma disjoint_of_subset (hs : s₁ ⊆ s₂) (ht : t₁ ⊆ t₂) (h : Disjoint s₂ t₂) : Disjoint s₁ t₁ :=
h.mono hs ht
#align set.disjoint_of_subset Set.disjoint_of_subset
@[simp]
lemma disjoint_union_left : Disjoint (s ∪ t) u ↔ Disjoint s u ∧ Disjoint t u := disjoint_sup_left
#align set.disjoint_union_left Set.disjoint_union_left
@[simp]
lemma disjoint_union_right : Disjoint s (t ∪ u) ↔ Disjoint s t ∧ Disjoint s u := disjoint_sup_right
#align set.disjoint_union_right Set.disjoint_union_right
@[simp] lemma disjoint_empty (s : Set α) : Disjoint s ∅ := disjoint_bot_right
#align set.disjoint_empty Set.disjoint_empty
@[simp] lemma empty_disjoint (s : Set α) : Disjoint ∅ s := disjoint_bot_left
#align set.empty_disjoint Set.empty_disjoint
@[simp] lemma univ_disjoint : Disjoint univ s ↔ s = ∅ := top_disjoint
#align set.univ_disjoint Set.univ_disjoint
@[simp] lemma disjoint_univ : Disjoint s univ ↔ s = ∅ := disjoint_top
#align set.disjoint_univ Set.disjoint_univ
lemma disjoint_sdiff_left : Disjoint (t \ s) s := disjoint_sdiff_self_left
#align set.disjoint_sdiff_left Set.disjoint_sdiff_left
lemma disjoint_sdiff_right : Disjoint s (t \ s) := disjoint_sdiff_self_right
#align set.disjoint_sdiff_right Set.disjoint_sdiff_right
-- TODO: prove this in terms of a lattice lemma
theorem disjoint_sdiff_inter : Disjoint (s \ t) (s ∩ t) :=
disjoint_of_subset_right inter_subset_right disjoint_sdiff_left
#align set.disjoint_sdiff_inter Set.disjoint_sdiff_inter
theorem diff_union_diff_cancel (hts : t ⊆ s) (hut : u ⊆ t) : s \ t ∪ t \ u = s \ u :=
sdiff_sup_sdiff_cancel hts hut
#align set.diff_union_diff_cancel Set.diff_union_diff_cancel
theorem diff_diff_eq_sdiff_union (h : u ⊆ s) : s \ (t \ u) = s \ t ∪ u := sdiff_sdiff_eq_sdiff_sup h
#align set.diff_diff_eq_sdiff_union Set.diff_diff_eq_sdiff_union
@[simp default+1]
lemma disjoint_singleton_left : Disjoint {a} s ↔ a ∉ s := by simp [Set.disjoint_iff, subset_def]
#align set.disjoint_singleton_left Set.disjoint_singleton_left
@[simp]
lemma disjoint_singleton_right : Disjoint s {a} ↔ a ∉ s :=
disjoint_comm.trans disjoint_singleton_left
#align set.disjoint_singleton_right Set.disjoint_singleton_right
lemma disjoint_singleton : Disjoint ({a} : Set α) {b} ↔ a ≠ b := by
simp
#align set.disjoint_singleton Set.disjoint_singleton
lemma subset_diff : s ⊆ t \ u ↔ s ⊆ t ∧ Disjoint s u := le_iff_subset.symm.trans le_sdiff
#align set.subset_diff Set.subset_diff
lemma ssubset_iff_sdiff_singleton : s ⊂ t ↔ ∃ a ∈ t, s ⊆ t \ {a} := by
simp [ssubset_iff_insert, subset_diff, insert_subset_iff]; aesop
theorem inter_diff_distrib_left (s t u : Set α) : s ∩ (t \ u) = (s ∩ t) \ (s ∩ u) :=
inf_sdiff_distrib_left _ _ _
#align set.inter_diff_distrib_left Set.inter_diff_distrib_left
theorem inter_diff_distrib_right (s t u : Set α) : s \ t ∩ u = (s ∩ u) \ (t ∩ u) :=
inf_sdiff_distrib_right _ _ _
#align set.inter_diff_distrib_right Set.inter_diff_distrib_right
theorem compl_def (s : Set α) : sᶜ = { x | x ∉ s } :=
rfl
#align set.compl_def Set.compl_def
theorem mem_compl {s : Set α} {x : α} (h : x ∉ s) : x ∈ sᶜ :=
h
#align set.mem_compl Set.mem_compl
theorem compl_setOf {α} (p : α → Prop) : { a | p a }ᶜ = { a | ¬p a } :=
rfl
#align set.compl_set_of Set.compl_setOf
theorem not_mem_of_mem_compl {s : Set α} {x : α} (h : x ∈ sᶜ) : x ∉ s :=
h
#align set.not_mem_of_mem_compl Set.not_mem_of_mem_compl
theorem not_mem_compl_iff {x : α} : x ∉ sᶜ ↔ x ∈ s :=
not_not
#align set.not_mem_compl_iff Set.not_mem_compl_iff
@[simp]
theorem inter_compl_self (s : Set α) : s ∩ sᶜ = ∅ :=
inf_compl_eq_bot
#align set.inter_compl_self Set.inter_compl_self
@[simp]
theorem compl_inter_self (s : Set α) : sᶜ ∩ s = ∅ :=
compl_inf_eq_bot
#align set.compl_inter_self Set.compl_inter_self
@[simp]
theorem compl_empty : (∅ : Set α)ᶜ = univ :=
compl_bot
#align set.compl_empty Set.compl_empty
@[simp]
theorem compl_union (s t : Set α) : (s ∪ t)ᶜ = sᶜ ∩ tᶜ :=
compl_sup
#align set.compl_union Set.compl_union
theorem compl_inter (s t : Set α) : (s ∩ t)ᶜ = sᶜ ∪ tᶜ :=
compl_inf
#align set.compl_inter Set.compl_inter
@[simp]
theorem compl_univ : (univ : Set α)ᶜ = ∅ :=
compl_top
#align set.compl_univ Set.compl_univ
@[simp]
theorem compl_empty_iff {s : Set α} : sᶜ = ∅ ↔ s = univ :=
compl_eq_bot
#align set.compl_empty_iff Set.compl_empty_iff
@[simp]
theorem compl_univ_iff {s : Set α} : sᶜ = univ ↔ s = ∅ :=
compl_eq_top
#align set.compl_univ_iff Set.compl_univ_iff
theorem compl_ne_univ : sᶜ ≠ univ ↔ s.Nonempty :=
compl_univ_iff.not.trans nonempty_iff_ne_empty.symm
#align set.compl_ne_univ Set.compl_ne_univ
theorem nonempty_compl : sᶜ.Nonempty ↔ s ≠ univ :=
(ne_univ_iff_exists_not_mem s).symm
#align set.nonempty_compl Set.nonempty_compl
@[simp] lemma nonempty_compl_of_nontrivial [Nontrivial α] (x : α) : Set.Nonempty {x}ᶜ := by
obtain ⟨y, hy⟩ := exists_ne x
exact ⟨y, by simp [hy]⟩
theorem mem_compl_singleton_iff {a x : α} : x ∈ ({a} : Set α)ᶜ ↔ x ≠ a :=
Iff.rfl
#align set.mem_compl_singleton_iff Set.mem_compl_singleton_iff
theorem compl_singleton_eq (a : α) : ({a} : Set α)ᶜ = { x | x ≠ a } :=
rfl
#align set.compl_singleton_eq Set.compl_singleton_eq
@[simp]
theorem compl_ne_eq_singleton (a : α) : ({ x | x ≠ a } : Set α)ᶜ = {a} :=
compl_compl _
#align set.compl_ne_eq_singleton Set.compl_ne_eq_singleton
theorem union_eq_compl_compl_inter_compl (s t : Set α) : s ∪ t = (sᶜ ∩ tᶜ)ᶜ :=
ext fun _ => or_iff_not_and_not
#align set.union_eq_compl_compl_inter_compl Set.union_eq_compl_compl_inter_compl
theorem inter_eq_compl_compl_union_compl (s t : Set α) : s ∩ t = (sᶜ ∪ tᶜ)ᶜ :=
ext fun _ => and_iff_not_or_not
#align set.inter_eq_compl_compl_union_compl Set.inter_eq_compl_compl_union_compl
@[simp]
theorem union_compl_self (s : Set α) : s ∪ sᶜ = univ :=
eq_univ_iff_forall.2 fun _ => em _
#align set.union_compl_self Set.union_compl_self
@[simp]
theorem compl_union_self (s : Set α) : sᶜ ∪ s = univ := by rw [union_comm, union_compl_self]
#align set.compl_union_self Set.compl_union_self
theorem compl_subset_comm : sᶜ ⊆ t ↔ tᶜ ⊆ s :=
@compl_le_iff_compl_le _ s _ _
#align set.compl_subset_comm Set.compl_subset_comm
theorem subset_compl_comm : s ⊆ tᶜ ↔ t ⊆ sᶜ :=
@le_compl_iff_le_compl _ _ _ t
#align set.subset_compl_comm Set.subset_compl_comm
@[simp]
theorem compl_subset_compl : sᶜ ⊆ tᶜ ↔ t ⊆ s :=
@compl_le_compl_iff_le (Set α) _ _ _
#align set.compl_subset_compl Set.compl_subset_compl
@[gcongr] theorem compl_subset_compl_of_subset (h : t ⊆ s) : sᶜ ⊆ tᶜ := compl_subset_compl.2 h
theorem subset_compl_iff_disjoint_left : s ⊆ tᶜ ↔ Disjoint t s :=
@le_compl_iff_disjoint_left (Set α) _ _ _
#align set.subset_compl_iff_disjoint_left Set.subset_compl_iff_disjoint_left
theorem subset_compl_iff_disjoint_right : s ⊆ tᶜ ↔ Disjoint s t :=
@le_compl_iff_disjoint_right (Set α) _ _ _
#align set.subset_compl_iff_disjoint_right Set.subset_compl_iff_disjoint_right
theorem disjoint_compl_left_iff_subset : Disjoint sᶜ t ↔ t ⊆ s :=
disjoint_compl_left_iff
#align set.disjoint_compl_left_iff_subset Set.disjoint_compl_left_iff_subset
theorem disjoint_compl_right_iff_subset : Disjoint s tᶜ ↔ s ⊆ t :=
disjoint_compl_right_iff
#align set.disjoint_compl_right_iff_subset Set.disjoint_compl_right_iff_subset
alias ⟨_, _root_.Disjoint.subset_compl_right⟩ := subset_compl_iff_disjoint_right
#align disjoint.subset_compl_right Disjoint.subset_compl_right
alias ⟨_, _root_.Disjoint.subset_compl_left⟩ := subset_compl_iff_disjoint_left
#align disjoint.subset_compl_left Disjoint.subset_compl_left
alias ⟨_, _root_.HasSubset.Subset.disjoint_compl_left⟩ := disjoint_compl_left_iff_subset
#align has_subset.subset.disjoint_compl_left HasSubset.Subset.disjoint_compl_left
alias ⟨_, _root_.HasSubset.Subset.disjoint_compl_right⟩ := disjoint_compl_right_iff_subset
#align has_subset.subset.disjoint_compl_right HasSubset.Subset.disjoint_compl_right
theorem subset_union_compl_iff_inter_subset {s t u : Set α} : s ⊆ t ∪ uᶜ ↔ s ∩ u ⊆ t :=
(@isCompl_compl _ u _).le_sup_right_iff_inf_left_le
#align set.subset_union_compl_iff_inter_subset Set.subset_union_compl_iff_inter_subset
theorem compl_subset_iff_union {s t : Set α} : sᶜ ⊆ t ↔ s ∪ t = univ :=
Iff.symm <| eq_univ_iff_forall.trans <| forall_congr' fun _ => or_iff_not_imp_left
#align set.compl_subset_iff_union Set.compl_subset_iff_union
@[simp]
theorem subset_compl_singleton_iff {a : α} {s : Set α} : s ⊆ {a}ᶜ ↔ a ∉ s :=
subset_compl_comm.trans singleton_subset_iff
#align set.subset_compl_singleton_iff Set.subset_compl_singleton_iff
theorem inter_subset (a b c : Set α) : a ∩ b ⊆ c ↔ a ⊆ bᶜ ∪ c :=
forall_congr' fun _ => and_imp.trans <| imp_congr_right fun _ => imp_iff_not_or
#align set.inter_subset Set.inter_subset
theorem inter_compl_nonempty_iff {s t : Set α} : (s ∩ tᶜ).Nonempty ↔ ¬s ⊆ t :=
(not_subset.trans <| exists_congr fun x => by simp [mem_compl]).symm
#align set.inter_compl_nonempty_iff Set.inter_compl_nonempty_iff
theorem not_mem_diff_of_mem {s t : Set α} {x : α} (hx : x ∈ t) : x ∉ s \ t := fun h => h.2 hx
#align set.not_mem_diff_of_mem Set.not_mem_diff_of_mem
theorem mem_of_mem_diff {s t : Set α} {x : α} (h : x ∈ s \ t) : x ∈ s :=
h.left
#align set.mem_of_mem_diff Set.mem_of_mem_diff
theorem not_mem_of_mem_diff {s t : Set α} {x : α} (h : x ∈ s \ t) : x ∉ t :=
h.right
#align set.not_mem_of_mem_diff Set.not_mem_of_mem_diff
theorem diff_eq_compl_inter {s t : Set α} : s \ t = tᶜ ∩ s := by rw [diff_eq, inter_comm]
#align set.diff_eq_compl_inter Set.diff_eq_compl_inter
theorem nonempty_diff {s t : Set α} : (s \ t).Nonempty ↔ ¬s ⊆ t :=
inter_compl_nonempty_iff
#align set.nonempty_diff Set.nonempty_diff
theorem diff_subset {s t : Set α} : s \ t ⊆ s := show s \ t ≤ s from sdiff_le
#align set.diff_subset Set.diff_subset
theorem diff_subset_compl (s t : Set α) : s \ t ⊆ tᶜ :=
diff_eq_compl_inter ▸ inter_subset_left
theorem union_diff_cancel' {s t u : Set α} (h₁ : s ⊆ t) (h₂ : t ⊆ u) : t ∪ u \ s = u :=
sup_sdiff_cancel' h₁ h₂
#align set.union_diff_cancel' Set.union_diff_cancel'
theorem union_diff_cancel {s t : Set α} (h : s ⊆ t) : s ∪ t \ s = t :=
sup_sdiff_cancel_right h
#align set.union_diff_cancel Set.union_diff_cancel
theorem union_diff_cancel_left {s t : Set α} (h : s ∩ t ⊆ ∅) : (s ∪ t) \ s = t :=
Disjoint.sup_sdiff_cancel_left <| disjoint_iff_inf_le.2 h
#align set.union_diff_cancel_left Set.union_diff_cancel_left
theorem union_diff_cancel_right {s t : Set α} (h : s ∩ t ⊆ ∅) : (s ∪ t) \ t = s :=
Disjoint.sup_sdiff_cancel_right <| disjoint_iff_inf_le.2 h
#align set.union_diff_cancel_right Set.union_diff_cancel_right
@[simp]
theorem union_diff_left {s t : Set α} : (s ∪ t) \ s = t \ s :=
sup_sdiff_left_self
#align set.union_diff_left Set.union_diff_left
@[simp]
theorem union_diff_right {s t : Set α} : (s ∪ t) \ t = s \ t :=
sup_sdiff_right_self
#align set.union_diff_right Set.union_diff_right
theorem union_diff_distrib {s t u : Set α} : (s ∪ t) \ u = s \ u ∪ t \ u :=
sup_sdiff
#align set.union_diff_distrib Set.union_diff_distrib
theorem inter_diff_assoc (a b c : Set α) : (a ∩ b) \ c = a ∩ (b \ c) :=
inf_sdiff_assoc
#align set.inter_diff_assoc Set.inter_diff_assoc
@[simp]
theorem inter_diff_self (a b : Set α) : a ∩ (b \ a) = ∅ :=
inf_sdiff_self_right
#align set.inter_diff_self Set.inter_diff_self
@[simp]
theorem inter_union_diff (s t : Set α) : s ∩ t ∪ s \ t = s :=
sup_inf_sdiff s t
#align set.inter_union_diff Set.inter_union_diff
@[simp]
theorem diff_union_inter (s t : Set α) : s \ t ∪ s ∩ t = s := by
rw [union_comm]
exact sup_inf_sdiff _ _
#align set.diff_union_inter Set.diff_union_inter
@[simp]
theorem inter_union_compl (s t : Set α) : s ∩ t ∪ s ∩ tᶜ = s :=
inter_union_diff _ _
#align set.inter_union_compl Set.inter_union_compl
@[gcongr]
theorem diff_subset_diff {s₁ s₂ t₁ t₂ : Set α} : s₁ ⊆ s₂ → t₂ ⊆ t₁ → s₁ \ t₁ ⊆ s₂ \ t₂ :=
show s₁ ≤ s₂ → t₂ ≤ t₁ → s₁ \ t₁ ≤ s₂ \ t₂ from sdiff_le_sdiff
#align set.diff_subset_diff Set.diff_subset_diff
@[gcongr]
theorem diff_subset_diff_left {s₁ s₂ t : Set α} (h : s₁ ⊆ s₂) : s₁ \ t ⊆ s₂ \ t :=
sdiff_le_sdiff_right ‹s₁ ≤ s₂›
#align set.diff_subset_diff_left Set.diff_subset_diff_left
@[gcongr]
theorem diff_subset_diff_right {s t u : Set α} (h : t ⊆ u) : s \ u ⊆ s \ t :=
sdiff_le_sdiff_left ‹t ≤ u›
#align set.diff_subset_diff_right Set.diff_subset_diff_right
theorem compl_eq_univ_diff (s : Set α) : sᶜ = univ \ s :=
top_sdiff.symm
#align set.compl_eq_univ_diff Set.compl_eq_univ_diff
@[simp]
theorem empty_diff (s : Set α) : (∅ \ s : Set α) = ∅ :=
bot_sdiff
#align set.empty_diff Set.empty_diff
theorem diff_eq_empty {s t : Set α} : s \ t = ∅ ↔ s ⊆ t :=
sdiff_eq_bot_iff
#align set.diff_eq_empty Set.diff_eq_empty
@[simp]
theorem diff_empty {s : Set α} : s \ ∅ = s :=
sdiff_bot
#align set.diff_empty Set.diff_empty
@[simp]
theorem diff_univ (s : Set α) : s \ univ = ∅ :=
diff_eq_empty.2 (subset_univ s)
#align set.diff_univ Set.diff_univ
theorem diff_diff {u : Set α} : (s \ t) \ u = s \ (t ∪ u) :=
sdiff_sdiff_left
#align set.diff_diff Set.diff_diff
-- the following statement contains parentheses to help the reader
theorem diff_diff_comm {s t u : Set α} : (s \ t) \ u = (s \ u) \ t :=
sdiff_sdiff_comm
#align set.diff_diff_comm Set.diff_diff_comm
theorem diff_subset_iff {s t u : Set α} : s \ t ⊆ u ↔ s ⊆ t ∪ u :=
show s \ t ≤ u ↔ s ≤ t ∪ u from sdiff_le_iff
#align set.diff_subset_iff Set.diff_subset_iff
theorem subset_diff_union (s t : Set α) : s ⊆ s \ t ∪ t :=
show s ≤ s \ t ∪ t from le_sdiff_sup
#align set.subset_diff_union Set.subset_diff_union
theorem diff_union_of_subset {s t : Set α} (h : t ⊆ s) : s \ t ∪ t = s :=
Subset.antisymm (union_subset diff_subset h) (subset_diff_union _ _)
#align set.diff_union_of_subset Set.diff_union_of_subset
@[simp]
theorem diff_singleton_subset_iff {x : α} {s t : Set α} : s \ {x} ⊆ t ↔ s ⊆ insert x t := by
rw [← union_singleton, union_comm]
apply diff_subset_iff
#align set.diff_singleton_subset_iff Set.diff_singleton_subset_iff
theorem subset_diff_singleton {x : α} {s t : Set α} (h : s ⊆ t) (hx : x ∉ s) : s ⊆ t \ {x} :=
subset_inter h <| subset_compl_comm.1 <| singleton_subset_iff.2 hx
#align set.subset_diff_singleton Set.subset_diff_singleton
theorem subset_insert_diff_singleton (x : α) (s : Set α) : s ⊆ insert x (s \ {x}) := by
rw [← diff_singleton_subset_iff]
#align set.subset_insert_diff_singleton Set.subset_insert_diff_singleton
theorem diff_subset_comm {s t u : Set α} : s \ t ⊆ u ↔ s \ u ⊆ t :=
show s \ t ≤ u ↔ s \ u ≤ t from sdiff_le_comm
#align set.diff_subset_comm Set.diff_subset_comm
theorem diff_inter {s t u : Set α} : s \ (t ∩ u) = s \ t ∪ s \ u :=
sdiff_inf
#align set.diff_inter Set.diff_inter
theorem diff_inter_diff {s t u : Set α} : s \ t ∩ (s \ u) = s \ (t ∪ u) :=
sdiff_sup.symm
#align set.diff_inter_diff Set.diff_inter_diff
theorem diff_compl : s \ tᶜ = s ∩ t :=
sdiff_compl
#align set.diff_compl Set.diff_compl
theorem diff_diff_right {s t u : Set α} : s \ (t \ u) = s \ t ∪ s ∩ u :=
sdiff_sdiff_right'
#align set.diff_diff_right Set.diff_diff_right
@[simp]
theorem insert_diff_of_mem (s) (h : a ∈ t) : insert a s \ t = s \ t := by
ext
constructor <;> simp (config := { contextual := true }) [or_imp, h]
#align set.insert_diff_of_mem Set.insert_diff_of_mem
theorem insert_diff_of_not_mem (s) (h : a ∉ t) : insert a s \ t = insert a (s \ t) := by
classical
ext x
by_cases h' : x ∈ t
· have : x ≠ a := by
intro H
rw [H] at h'
exact h h'
simp [h, h', this]
· simp [h, h']
#align set.insert_diff_of_not_mem Set.insert_diff_of_not_mem
theorem insert_diff_self_of_not_mem {a : α} {s : Set α} (h : a ∉ s) : insert a s \ {a} = s := by
ext x
simp [and_iff_left_of_imp fun hx : x ∈ s => show x ≠ a from fun hxa => h <| hxa ▸ hx]
#align set.insert_diff_self_of_not_mem Set.insert_diff_self_of_not_mem
@[simp]
theorem insert_diff_eq_singleton {a : α} {s : Set α} (h : a ∉ s) : insert a s \ s = {a} := by
ext
rw [Set.mem_diff, Set.mem_insert_iff, Set.mem_singleton_iff, or_and_right, and_not_self_iff,
or_false_iff, and_iff_left_iff_imp]
rintro rfl
exact h
#align set.insert_diff_eq_singleton Set.insert_diff_eq_singleton
theorem inter_insert_of_mem (h : a ∈ s) : s ∩ insert a t = insert a (s ∩ t) := by
rw [insert_inter_distrib, insert_eq_of_mem h]
#align set.inter_insert_of_mem Set.inter_insert_of_mem
theorem insert_inter_of_mem (h : a ∈ t) : insert a s ∩ t = insert a (s ∩ t) := by
rw [insert_inter_distrib, insert_eq_of_mem h]
#align set.insert_inter_of_mem Set.insert_inter_of_mem
theorem inter_insert_of_not_mem (h : a ∉ s) : s ∩ insert a t = s ∩ t :=
ext fun _ => and_congr_right fun hx => or_iff_right <| ne_of_mem_of_not_mem hx h
#align set.inter_insert_of_not_mem Set.inter_insert_of_not_mem
theorem insert_inter_of_not_mem (h : a ∉ t) : insert a s ∩ t = s ∩ t :=
ext fun _ => and_congr_left fun hx => or_iff_right <| ne_of_mem_of_not_mem hx h
#align set.insert_inter_of_not_mem Set.insert_inter_of_not_mem
@[simp]
theorem union_diff_self {s t : Set α} : s ∪ t \ s = s ∪ t :=
sup_sdiff_self _ _
#align set.union_diff_self Set.union_diff_self
@[simp]
theorem diff_union_self {s t : Set α} : s \ t ∪ t = s ∪ t :=
sdiff_sup_self _ _
#align set.diff_union_self Set.diff_union_self
@[simp]
theorem diff_inter_self {a b : Set α} : b \ a ∩ a = ∅ :=
inf_sdiff_self_left
#align set.diff_inter_self Set.diff_inter_self
@[simp]
theorem diff_inter_self_eq_diff {s t : Set α} : s \ (t ∩ s) = s \ t :=
sdiff_inf_self_right _ _
#align set.diff_inter_self_eq_diff Set.diff_inter_self_eq_diff
@[simp]
theorem diff_self_inter {s t : Set α} : s \ (s ∩ t) = s \ t :=
sdiff_inf_self_left _ _
#align set.diff_self_inter Set.diff_self_inter
@[simp]
theorem diff_singleton_eq_self {a : α} {s : Set α} (h : a ∉ s) : s \ {a} = s :=
sdiff_eq_self_iff_disjoint.2 <| by simp [h]
#align set.diff_singleton_eq_self Set.diff_singleton_eq_self
@[simp]
theorem diff_singleton_sSubset {s : Set α} {a : α} : s \ {a} ⊂ s ↔ a ∈ s :=
sdiff_le.lt_iff_ne.trans <| sdiff_eq_left.not.trans <| by simp
#align set.diff_singleton_ssubset Set.diff_singleton_sSubset
@[simp]
theorem insert_diff_singleton {a : α} {s : Set α} : insert a (s \ {a}) = insert a s := by
simp [insert_eq, union_diff_self, -union_singleton, -singleton_union]
#align set.insert_diff_singleton Set.insert_diff_singleton
theorem insert_diff_singleton_comm (hab : a ≠ b) (s : Set α) :
insert a (s \ {b}) = insert a s \ {b} := by
simp_rw [← union_singleton, union_diff_distrib,
diff_singleton_eq_self (mem_singleton_iff.not.2 hab.symm)]
#align set.insert_diff_singleton_comm Set.insert_diff_singleton_comm
--Porting note (#10618): removed `simp` attribute because `simp` can prove it
theorem diff_self {s : Set α} : s \ s = ∅ :=
sdiff_self
#align set.diff_self Set.diff_self
theorem diff_diff_right_self (s t : Set α) : s \ (s \ t) = s ∩ t :=
sdiff_sdiff_right_self
#align set.diff_diff_right_self Set.diff_diff_right_self
theorem diff_diff_cancel_left {s t : Set α} (h : s ⊆ t) : t \ (t \ s) = s :=
sdiff_sdiff_eq_self h
#align set.diff_diff_cancel_left Set.diff_diff_cancel_left
theorem mem_diff_singleton {x y : α} {s : Set α} : x ∈ s \ {y} ↔ x ∈ s ∧ x ≠ y :=
Iff.rfl
#align set.mem_diff_singleton Set.mem_diff_singleton
theorem mem_diff_singleton_empty {t : Set (Set α)} : s ∈ t \ {∅} ↔ s ∈ t ∧ s.Nonempty :=
mem_diff_singleton.trans <| and_congr_right' nonempty_iff_ne_empty.symm
#align set.mem_diff_singleton_empty Set.mem_diff_singleton_empty
theorem subset_insert_iff {s t : Set α} {x : α} :
s ⊆ insert x t ↔ s ⊆ t ∨ (x ∈ s ∧ s \ {x} ⊆ t) := by
rw [← diff_singleton_subset_iff]
by_cases hx : x ∈ s
· rw [and_iff_right hx, or_iff_right_of_imp diff_subset.trans]
rw [diff_singleton_eq_self hx, or_iff_left_of_imp And.right]
theorem union_eq_diff_union_diff_union_inter (s t : Set α) : s ∪ t = s \ t ∪ t \ s ∪ s ∩ t :=
sup_eq_sdiff_sup_sdiff_sup_inf
#align set.union_eq_diff_union_diff_union_inter Set.union_eq_diff_union_diff_union_inter
--Porting note (#10618): removed `simp` attribute because `simp` can prove it
theorem pair_eq_singleton (a : α) : ({a, a} : Set α) = {a} :=
union_self _
#align set.pair_eq_singleton Set.pair_eq_singleton
theorem pair_comm (a b : α) : ({a, b} : Set α) = {b, a} :=
union_comm _ _
#align set.pair_comm Set.pair_comm
theorem pair_eq_pair_iff {x y z w : α} :
({x, y} : Set α) = {z, w} ↔ x = z ∧ y = w ∨ x = w ∧ y = z := by
simp [subset_antisymm_iff, insert_subset_iff]; aesop
#align set.pair_eq_pair_iff Set.pair_eq_pair_iff
theorem pair_diff_left (hne : a ≠ b) : ({a, b} : Set α) \ {a} = {b} := by
rw [insert_diff_of_mem _ (mem_singleton a), diff_singleton_eq_self (by simpa)]
theorem pair_diff_right (hne : a ≠ b) : ({a, b} : Set α) \ {b} = {a} := by
rw [pair_comm, pair_diff_left hne.symm]
theorem pair_subset_iff : {a, b} ⊆ s ↔ a ∈ s ∧ b ∈ s := by
rw [insert_subset_iff, singleton_subset_iff]
theorem pair_subset (ha : a ∈ s) (hb : b ∈ s) : {a, b} ⊆ s :=
pair_subset_iff.2 ⟨ha,hb⟩
theorem subset_pair_iff : s ⊆ {a, b} ↔ ∀ x ∈ s, x = a ∨ x = b := by
simp [subset_def]
theorem subset_pair_iff_eq {x y : α} : s ⊆ {x, y} ↔ s = ∅ ∨ s = {x} ∨ s = {y} ∨ s = {x, y} := by
refine ⟨?_, by rintro (rfl | rfl | rfl | rfl) <;> simp [pair_subset_iff]⟩
rw [subset_insert_iff, subset_singleton_iff_eq, subset_singleton_iff_eq,
← subset_empty_iff (s := s \ {x}), diff_subset_iff, union_empty, subset_singleton_iff_eq]
have h : x ∈ s → {y} = s \ {x} → s = {x,y} := fun h₁ h₂ ↦ by simp [h₁, h₂]
tauto
theorem Nonempty.subset_pair_iff_eq (hs : s.Nonempty) :
s ⊆ {a, b} ↔ s = {a} ∨ s = {b} ∨ s = {a, b} := by
rw [Set.subset_pair_iff_eq, or_iff_right]; exact hs.ne_empty
section
open scoped symmDiff
theorem mem_symmDiff : a ∈ s ∆ t ↔ a ∈ s ∧ a ∉ t ∨ a ∈ t ∧ a ∉ s :=
Iff.rfl
#align set.mem_symm_diff Set.mem_symmDiff
protected theorem symmDiff_def (s t : Set α) : s ∆ t = s \ t ∪ t \ s :=
rfl
#align set.symm_diff_def Set.symmDiff_def
theorem symmDiff_subset_union : s ∆ t ⊆ s ∪ t :=
@symmDiff_le_sup (Set α) _ _ _
#align set.symm_diff_subset_union Set.symmDiff_subset_union
@[simp]
theorem symmDiff_eq_empty : s ∆ t = ∅ ↔ s = t :=
symmDiff_eq_bot
#align set.symm_diff_eq_empty Set.symmDiff_eq_empty
@[simp]
theorem symmDiff_nonempty : (s ∆ t).Nonempty ↔ s ≠ t :=
nonempty_iff_ne_empty.trans symmDiff_eq_empty.not
#align set.symm_diff_nonempty Set.symmDiff_nonempty
theorem inter_symmDiff_distrib_left (s t u : Set α) : s ∩ t ∆ u = (s ∩ t) ∆ (s ∩ u) :=
inf_symmDiff_distrib_left _ _ _
#align set.inter_symm_diff_distrib_left Set.inter_symmDiff_distrib_left
theorem inter_symmDiff_distrib_right (s t u : Set α) : s ∆ t ∩ u = (s ∩ u) ∆ (t ∩ u) :=
inf_symmDiff_distrib_right _ _ _
#align set.inter_symm_diff_distrib_right Set.inter_symmDiff_distrib_right
theorem subset_symmDiff_union_symmDiff_left (h : Disjoint s t) : u ⊆ s ∆ u ∪ t ∆ u :=
h.le_symmDiff_sup_symmDiff_left
#align set.subset_symm_diff_union_symm_diff_left Set.subset_symmDiff_union_symmDiff_left
theorem subset_symmDiff_union_symmDiff_right (h : Disjoint t u) : s ⊆ s ∆ t ∪ s ∆ u :=
h.le_symmDiff_sup_symmDiff_right
#align set.subset_symm_diff_union_symm_diff_right Set.subset_symmDiff_union_symmDiff_right
end
#align set.powerset Set.powerset
theorem mem_powerset {x s : Set α} (h : x ⊆ s) : x ∈ 𝒫 s := @h
#align set.mem_powerset Set.mem_powerset
theorem subset_of_mem_powerset {x s : Set α} (h : x ∈ 𝒫 s) : x ⊆ s := @h
#align set.subset_of_mem_powerset Set.subset_of_mem_powerset
@[simp]
theorem mem_powerset_iff (x s : Set α) : x ∈ 𝒫 s ↔ x ⊆ s :=
Iff.rfl
#align set.mem_powerset_iff Set.mem_powerset_iff
theorem powerset_inter (s t : Set α) : 𝒫(s ∩ t) = 𝒫 s ∩ 𝒫 t :=
ext fun _ => subset_inter_iff
#align set.powerset_inter Set.powerset_inter
@[simp]
theorem powerset_mono : 𝒫 s ⊆ 𝒫 t ↔ s ⊆ t :=
⟨fun h => @h _ (fun _ h => h), fun h _ hu _ ha => h (hu ha)⟩
#align set.powerset_mono Set.powerset_mono
theorem monotone_powerset : Monotone (powerset : Set α → Set (Set α)) := fun _ _ => powerset_mono.2
#align set.monotone_powerset Set.monotone_powerset
@[simp]
theorem powerset_nonempty : (𝒫 s).Nonempty :=
⟨∅, fun _ h => empty_subset s h⟩
#align set.powerset_nonempty Set.powerset_nonempty
@[simp]
theorem powerset_empty : 𝒫(∅ : Set α) = {∅} :=
ext fun _ => subset_empty_iff
#align set.powerset_empty Set.powerset_empty
@[simp]
theorem powerset_univ : 𝒫(univ : Set α) = univ :=
eq_univ_of_forall subset_univ
#align set.powerset_univ Set.powerset_univ
theorem powerset_singleton (x : α) : 𝒫({x} : Set α) = {∅, {x}} := by
ext y
rw [mem_powerset_iff, subset_singleton_iff_eq, mem_insert_iff, mem_singleton_iff]
#align set.powerset_singleton Set.powerset_singleton
theorem mem_dite (p : Prop) [Decidable p] (s : p → Set α) (t : ¬ p → Set α) (x : α) :
(x ∈ if h : p then s h else t h) ↔ (∀ h : p, x ∈ s h) ∧ ∀ h : ¬p, x ∈ t h := by
split_ifs with hp
· exact ⟨fun hx => ⟨fun _ => hx, fun hnp => (hnp hp).elim⟩, fun hx => hx.1 hp⟩
· exact ⟨fun hx => ⟨fun h => (hp h).elim, fun _ => hx⟩, fun hx => hx.2 hp⟩
theorem mem_dite_univ_right (p : Prop) [Decidable p] (t : p → Set α) (x : α) :
(x ∈ if h : p then t h else univ) ↔ ∀ h : p, x ∈ t h := by
split_ifs <;> simp_all
#align set.mem_dite_univ_right Set.mem_dite_univ_right
@[simp]
theorem mem_ite_univ_right (p : Prop) [Decidable p] (t : Set α) (x : α) :
x ∈ ite p t Set.univ ↔ p → x ∈ t :=
mem_dite_univ_right p (fun _ => t) x
#align set.mem_ite_univ_right Set.mem_ite_univ_right
theorem mem_dite_univ_left (p : Prop) [Decidable p] (t : ¬p → Set α) (x : α) :
(x ∈ if h : p then univ else t h) ↔ ∀ h : ¬p, x ∈ t h := by
split_ifs <;> simp_all
#align set.mem_dite_univ_left Set.mem_dite_univ_left
@[simp]
theorem mem_ite_univ_left (p : Prop) [Decidable p] (t : Set α) (x : α) :
x ∈ ite p Set.univ t ↔ ¬p → x ∈ t :=
mem_dite_univ_left p (fun _ => t) x
#align set.mem_ite_univ_left Set.mem_ite_univ_left
theorem mem_dite_empty_right (p : Prop) [Decidable p] (t : p → Set α) (x : α) :
(x ∈ if h : p then t h else ∅) ↔ ∃ h : p, x ∈ t h := by
simp only [mem_dite, mem_empty_iff_false, imp_false, not_not]
exact ⟨fun h => ⟨h.2, h.1 h.2⟩, fun ⟨h₁, h₂⟩ => ⟨fun _ => h₂, h₁⟩⟩
#align set.mem_dite_empty_right Set.mem_dite_empty_right
@[simp]
theorem mem_ite_empty_right (p : Prop) [Decidable p] (t : Set α) (x : α) :
x ∈ ite p t ∅ ↔ p ∧ x ∈ t :=
(mem_dite_empty_right p (fun _ => t) x).trans (by simp)
#align set.mem_ite_empty_right Set.mem_ite_empty_right
| Mathlib/Data/Set/Basic.lean | 2,244 | 2,247 | theorem mem_dite_empty_left (p : Prop) [Decidable p] (t : ¬p → Set α) (x : α) :
(x ∈ if h : p then ∅ else t h) ↔ ∃ h : ¬p, x ∈ t h := by |
simp only [mem_dite, mem_empty_iff_false, imp_false]
exact ⟨fun h => ⟨h.1, h.2 h.1⟩, fun ⟨h₁, h₂⟩ => ⟨fun h => h₁ h, fun _ => h₂⟩⟩
|
import Mathlib.Algebra.Polynomial.RingDivision
import Mathlib.RingTheory.Localization.FractionRing
#align_import data.polynomial.ring_division from "leanprover-community/mathlib"@"8efcf8022aac8e01df8d302dcebdbc25d6a886c8"
noncomputable section
namespace Polynomial
universe u v w z
variable {R : Type u} {S : Type v} {T : Type w} {a b : R} {n : ℕ}
section CommRing
variable [CommRing R] [IsDomain R] {p q : R[X]}
section Roots
open Multiset Finset
noncomputable def roots (p : R[X]) : Multiset R :=
haveI := Classical.decEq R
haveI := Classical.dec (p = 0)
if h : p = 0 then ∅ else Classical.choose (exists_multiset_roots h)
#align polynomial.roots Polynomial.roots
theorem roots_def [DecidableEq R] (p : R[X]) [Decidable (p = 0)] :
p.roots = if h : p = 0 then ∅ else Classical.choose (exists_multiset_roots h) := by
-- porting noteL `‹_›` doesn't work for instance arguments
rename_i iR ip0
obtain rfl := Subsingleton.elim iR (Classical.decEq R)
obtain rfl := Subsingleton.elim ip0 (Classical.dec (p = 0))
rfl
#align polynomial.roots_def Polynomial.roots_def
@[simp]
theorem roots_zero : (0 : R[X]).roots = 0 :=
dif_pos rfl
#align polynomial.roots_zero Polynomial.roots_zero
theorem card_roots (hp0 : p ≠ 0) : (Multiset.card (roots p) : WithBot ℕ) ≤ degree p := by
classical
unfold roots
rw [dif_neg hp0]
exact (Classical.choose_spec (exists_multiset_roots hp0)).1
#align polynomial.card_roots Polynomial.card_roots
theorem card_roots' (p : R[X]) : Multiset.card p.roots ≤ natDegree p := by
by_cases hp0 : p = 0
· simp [hp0]
exact WithBot.coe_le_coe.1 (le_trans (card_roots hp0) (le_of_eq <| degree_eq_natDegree hp0))
#align polynomial.card_roots' Polynomial.card_roots'
theorem card_roots_sub_C {p : R[X]} {a : R} (hp0 : 0 < degree p) :
(Multiset.card (p - C a).roots : WithBot ℕ) ≤ degree p :=
calc
(Multiset.card (p - C a).roots : WithBot ℕ) ≤ degree (p - C a) :=
card_roots <| mt sub_eq_zero.1 fun h => not_le_of_gt hp0 <| h.symm ▸ degree_C_le
_ = degree p := by rw [sub_eq_add_neg, ← C_neg]; exact degree_add_C hp0
set_option linter.uppercaseLean3 false in
#align polynomial.card_roots_sub_C Polynomial.card_roots_sub_C
theorem card_roots_sub_C' {p : R[X]} {a : R} (hp0 : 0 < degree p) :
Multiset.card (p - C a).roots ≤ natDegree p :=
WithBot.coe_le_coe.1
(le_trans (card_roots_sub_C hp0)
(le_of_eq <| degree_eq_natDegree fun h => by simp_all [lt_irrefl]))
set_option linter.uppercaseLean3 false in
#align polynomial.card_roots_sub_C' Polynomial.card_roots_sub_C'
@[simp]
theorem count_roots [DecidableEq R] (p : R[X]) : p.roots.count a = rootMultiplicity a p := by
classical
by_cases hp : p = 0
· simp [hp]
rw [roots_def, dif_neg hp]
exact (Classical.choose_spec (exists_multiset_roots hp)).2 a
#align polynomial.count_roots Polynomial.count_roots
@[simp]
theorem mem_roots' : a ∈ p.roots ↔ p ≠ 0 ∧ IsRoot p a := by
classical
rw [← count_pos, count_roots p, rootMultiplicity_pos']
#align polynomial.mem_roots' Polynomial.mem_roots'
theorem mem_roots (hp : p ≠ 0) : a ∈ p.roots ↔ IsRoot p a :=
mem_roots'.trans <| and_iff_right hp
#align polynomial.mem_roots Polynomial.mem_roots
theorem ne_zero_of_mem_roots (h : a ∈ p.roots) : p ≠ 0 :=
(mem_roots'.1 h).1
#align polynomial.ne_zero_of_mem_roots Polynomial.ne_zero_of_mem_roots
theorem isRoot_of_mem_roots (h : a ∈ p.roots) : IsRoot p a :=
(mem_roots'.1 h).2
#align polynomial.is_root_of_mem_roots Polynomial.isRoot_of_mem_roots
-- Porting note: added during port.
lemma mem_roots_iff_aeval_eq_zero {x : R} (w : p ≠ 0) : x ∈ roots p ↔ aeval x p = 0 := by
rw [mem_roots w, IsRoot.def, aeval_def, eval₂_eq_eval_map]
simp
theorem card_le_degree_of_subset_roots {p : R[X]} {Z : Finset R} (h : Z.val ⊆ p.roots) :
Z.card ≤ p.natDegree :=
(Multiset.card_le_card (Finset.val_le_iff_val_subset.2 h)).trans (Polynomial.card_roots' p)
#align polynomial.card_le_degree_of_subset_roots Polynomial.card_le_degree_of_subset_roots
theorem finite_setOf_isRoot {p : R[X]} (hp : p ≠ 0) : Set.Finite { x | IsRoot p x } := by
classical
simpa only [← Finset.setOf_mem, Multiset.mem_toFinset, mem_roots hp]
using p.roots.toFinset.finite_toSet
#align polynomial.finite_set_of_is_root Polynomial.finite_setOf_isRoot
theorem eq_zero_of_infinite_isRoot (p : R[X]) (h : Set.Infinite { x | IsRoot p x }) : p = 0 :=
not_imp_comm.mp finite_setOf_isRoot h
#align polynomial.eq_zero_of_infinite_is_root Polynomial.eq_zero_of_infinite_isRoot
theorem exists_max_root [LinearOrder R] (p : R[X]) (hp : p ≠ 0) : ∃ x₀, ∀ x, p.IsRoot x → x ≤ x₀ :=
Set.exists_upper_bound_image _ _ <| finite_setOf_isRoot hp
#align polynomial.exists_max_root Polynomial.exists_max_root
theorem exists_min_root [LinearOrder R] (p : R[X]) (hp : p ≠ 0) : ∃ x₀, ∀ x, p.IsRoot x → x₀ ≤ x :=
Set.exists_lower_bound_image _ _ <| finite_setOf_isRoot hp
#align polynomial.exists_min_root Polynomial.exists_min_root
theorem eq_of_infinite_eval_eq (p q : R[X]) (h : Set.Infinite { x | eval x p = eval x q }) :
p = q := by
rw [← sub_eq_zero]
apply eq_zero_of_infinite_isRoot
simpa only [IsRoot, eval_sub, sub_eq_zero]
#align polynomial.eq_of_infinite_eval_eq Polynomial.eq_of_infinite_eval_eq
theorem roots_mul {p q : R[X]} (hpq : p * q ≠ 0) : (p * q).roots = p.roots + q.roots := by
classical
exact Multiset.ext.mpr fun r => by
rw [count_add, count_roots, count_roots, count_roots, rootMultiplicity_mul hpq]
#align polynomial.roots_mul Polynomial.roots_mul
theorem roots.le_of_dvd (h : q ≠ 0) : p ∣ q → roots p ≤ roots q := by
rintro ⟨k, rfl⟩
exact Multiset.le_iff_exists_add.mpr ⟨k.roots, roots_mul h⟩
#align polynomial.roots.le_of_dvd Polynomial.roots.le_of_dvd
theorem mem_roots_sub_C' {p : R[X]} {a x : R} : x ∈ (p - C a).roots ↔ p ≠ C a ∧ p.eval x = a := by
rw [mem_roots', IsRoot.def, sub_ne_zero, eval_sub, sub_eq_zero, eval_C]
set_option linter.uppercaseLean3 false in
#align polynomial.mem_roots_sub_C' Polynomial.mem_roots_sub_C'
theorem mem_roots_sub_C {p : R[X]} {a x : R} (hp0 : 0 < degree p) :
x ∈ (p - C a).roots ↔ p.eval x = a :=
mem_roots_sub_C'.trans <| and_iff_right fun hp => hp0.not_le <| hp.symm ▸ degree_C_le
set_option linter.uppercaseLean3 false in
#align polynomial.mem_roots_sub_C Polynomial.mem_roots_sub_C
@[simp]
| Mathlib/Algebra/Polynomial/Roots.lean | 184 | 187 | theorem roots_X_sub_C (r : R) : roots (X - C r) = {r} := by |
classical
ext s
rw [count_roots, rootMultiplicity_X_sub_C, count_singleton]
|
import Mathlib.Algebra.Group.Support
import Mathlib.Data.Set.Pointwise.SMul
#align_import data.set.pointwise.support from "leanprover-community/mathlib"@"f7fc89d5d5ff1db2d1242c7bb0e9062ce47ef47c"
open Pointwise
open Function Set
section Group
variable {α β γ : Type*} [Group α] [MulAction α β]
theorem mulSupport_comp_inv_smul [One γ] (c : α) (f : β → γ) :
(mulSupport fun x ↦ f (c⁻¹ • x)) = c • mulSupport f := by
ext x
simp only [mem_smul_set_iff_inv_smul_mem, mem_mulSupport]
#align mul_support_comp_inv_smul mulSupport_comp_inv_smul
| Mathlib/Data/Set/Pointwise/Support.lean | 34 | 37 | theorem support_comp_inv_smul [Zero γ] (c : α) (f : β → γ) :
(support fun x ↦ f (c⁻¹ • x)) = c • support f := by |
ext x
simp only [mem_smul_set_iff_inv_smul_mem, mem_support]
|
import Mathlib.Algebra.Polynomial.Smeval
import Mathlib.GroupTheory.GroupAction.Ring
import Mathlib.RingTheory.Polynomial.Pochhammer
section Multichoose
open Function Polynomial
class BinomialRing (R : Type*) [AddCommMonoid R] [Pow R ℕ] where
nsmul_right_injective (n : ℕ) (h : n ≠ 0) : Injective (n • · : R → R)
multichoose : R → ℕ → R
factorial_nsmul_multichoose (r : R) (n : ℕ) :
n.factorial • multichoose r n = (ascPochhammer ℕ n).smeval r
section Pochhammer
section Choose
namespace Ring
open Polynomial
variable {R : Type*}
def choose [AddCommGroupWithOne R] [Pow R ℕ] [BinomialRing R] (r : R) (n : ℕ): R :=
multichoose (r - n + 1) n
variable [NonAssocRing R] [Pow R ℕ] [BinomialRing R]
theorem descPochhammer_eq_factorial_smul_choose [NatPowAssoc R] (r : R) (n : ℕ) :
(descPochhammer ℤ n).smeval r = n.factorial • choose r n := by
rw [choose, factorial_nsmul_multichoose_eq_ascPochhammer, descPochhammer_eq_ascPochhammer,
smeval_comp, add_comm_sub, smeval_add, smeval_X, npow_one]
have h : smeval (1 - n : Polynomial ℤ) r = 1 - n := by
rw [← C_eq_natCast, ← C_1, ← C_sub, smeval_C]
simp only [npow_zero, zsmul_one, Int.cast_sub, Int.cast_one, Int.cast_natCast]
rw [h, ascPochhammer_smeval_cast, add_comm_sub]
| Mathlib/RingTheory/Binomial.lean | 203 | 207 | theorem choose_natCast [NatPowAssoc R] (n k : ℕ) : choose (n : R) k = Nat.choose n k := by |
refine nsmul_right_injective (Nat.factorial k) (Nat.factorial_ne_zero k) ?_
simp only
rw [← descPochhammer_eq_factorial_smul_choose, nsmul_eq_mul, ← Nat.cast_mul,
← Nat.descFactorial_eq_factorial_mul_choose, ← descPochhammer_smeval_eq_descFactorial]
|
import Mathlib.Algebra.BigOperators.Group.Finset
import Mathlib.Order.SupIndep
import Mathlib.Order.Atoms
#align_import order.partition.finpartition from "leanprover-community/mathlib"@"d6fad0e5bf2d6f48da9175d25c3dc5706b3834ce"
open Finset Function
variable {α : Type*}
@[ext]
structure Finpartition [Lattice α] [OrderBot α] (a : α) where
-- Porting note: Docstrings added
parts : Finset α
supIndep : parts.SupIndep id
sup_parts : parts.sup id = a
not_bot_mem : ⊥ ∉ parts
deriving DecidableEq
#align finpartition Finpartition
#align finpartition.parts Finpartition.parts
#align finpartition.sup_indep Finpartition.supIndep
#align finpartition.sup_parts Finpartition.sup_parts
#align finpartition.not_bot_mem Finpartition.not_bot_mem
-- Porting note: attribute [protected] doesn't work
-- attribute [protected] Finpartition.supIndep
namespace Finpartition
section Lattice
variable [Lattice α] [OrderBot α]
@[simps]
def ofErase [DecidableEq α] {a : α} (parts : Finset α) (sup_indep : parts.SupIndep id)
(sup_parts : parts.sup id = a) : Finpartition a where
parts := parts.erase ⊥
supIndep := sup_indep.subset (erase_subset _ _)
sup_parts := (sup_erase_bot _).trans sup_parts
not_bot_mem := not_mem_erase _ _
#align finpartition.of_erase Finpartition.ofErase
@[simps]
def ofSubset {a b : α} (P : Finpartition a) {parts : Finset α} (subset : parts ⊆ P.parts)
(sup_parts : parts.sup id = b) : Finpartition b :=
{ parts := parts
supIndep := P.supIndep.subset subset
sup_parts := sup_parts
not_bot_mem := fun h ↦ P.not_bot_mem (subset h) }
#align finpartition.of_subset Finpartition.ofSubset
@[simps]
def copy {a b : α} (P : Finpartition a) (h : a = b) : Finpartition b where
parts := P.parts
supIndep := P.supIndep
sup_parts := h ▸ P.sup_parts
not_bot_mem := P.not_bot_mem
#align finpartition.copy Finpartition.copy
def map {β : Type*} [Lattice β] [OrderBot β] {a : α} (e : α ≃o β) (P : Finpartition a) :
Finpartition (e a) where
parts := P.parts.map e
supIndep u hu _ hb hbu _ hx hxu := by
rw [← map_symm_subset] at hu
simp only [mem_map_equiv] at hb
have := P.supIndep hu hb (by simp [hbu]) (map_rel e.symm hx) ?_
· rw [← e.symm.map_bot] at this
exact e.symm.map_rel_iff.mp this
· convert e.symm.map_rel_iff.mpr hxu
rw [map_finset_sup, sup_map]
rfl
sup_parts := by simp [← P.sup_parts]
not_bot_mem := by
rw [mem_map_equiv]
convert P.not_bot_mem
exact e.symm.map_bot
@[simp]
theorem parts_map {β : Type*} [Lattice β] [OrderBot β] {a : α} {e : α ≃o β} {P : Finpartition a} :
(P.map e).parts = P.parts.map e := rfl
variable (α)
@[simps]
protected def empty : Finpartition (⊥ : α) where
parts := ∅
supIndep := supIndep_empty _
sup_parts := Finset.sup_empty
not_bot_mem := not_mem_empty ⊥
#align finpartition.empty Finpartition.empty
instance : Inhabited (Finpartition (⊥ : α)) :=
⟨Finpartition.empty α⟩
@[simp]
theorem default_eq_empty : (default : Finpartition (⊥ : α)) = Finpartition.empty α :=
rfl
#align finpartition.default_eq_empty Finpartition.default_eq_empty
variable {α} {a : α}
@[simps]
def indiscrete (ha : a ≠ ⊥) : Finpartition a where
parts := {a}
supIndep := supIndep_singleton _ _
sup_parts := Finset.sup_singleton
not_bot_mem h := ha (mem_singleton.1 h).symm
#align finpartition.indiscrete Finpartition.indiscrete
variable (P : Finpartition a)
protected theorem le {b : α} (hb : b ∈ P.parts) : b ≤ a :=
(le_sup hb).trans P.sup_parts.le
#align finpartition.le Finpartition.le
theorem ne_bot {b : α} (hb : b ∈ P.parts) : b ≠ ⊥ := by
intro h
refine P.not_bot_mem (?_)
rw [h] at hb
exact hb
#align finpartition.ne_bot Finpartition.ne_bot
protected theorem disjoint : (P.parts : Set α).PairwiseDisjoint id :=
P.supIndep.pairwiseDisjoint
#align finpartition.disjoint Finpartition.disjoint
variable {P}
theorem parts_eq_empty_iff : P.parts = ∅ ↔ a = ⊥ := by
simp_rw [← P.sup_parts]
refine ⟨fun h ↦ ?_, fun h ↦ eq_empty_iff_forall_not_mem.2 fun b hb ↦ P.not_bot_mem ?_⟩
· rw [h]
exact Finset.sup_empty
· rwa [← le_bot_iff.1 ((le_sup hb).trans h.le)]
#align finpartition.parts_eq_empty_iff Finpartition.parts_eq_empty_iff
| Mathlib/Order/Partition/Finpartition.lean | 199 | 200 | theorem parts_nonempty_iff : P.parts.Nonempty ↔ a ≠ ⊥ := by |
rw [nonempty_iff_ne_empty, not_iff_not, parts_eq_empty_iff]
|
import Mathlib.Algebra.MvPolynomial.Monad
#align_import data.mv_polynomial.expand from "leanprover-community/mathlib"@"5da451b4c96b4c2e122c0325a7fce17d62ee46c6"
namespace MvPolynomial
variable {σ τ R S : Type*} [CommSemiring R] [CommSemiring S]
noncomputable def expand (p : ℕ) : MvPolynomial σ R →ₐ[R] MvPolynomial σ R :=
{ (eval₂Hom C fun i ↦ X i ^ p : MvPolynomial σ R →+* MvPolynomial σ R) with
commutes' := fun _ ↦ eval₂Hom_C _ _ _ }
#align mv_polynomial.expand MvPolynomial.expand
-- @[simp] -- Porting note (#10618): simp can prove this
theorem expand_C (p : ℕ) (r : R) : expand p (C r : MvPolynomial σ R) = C r :=
eval₂Hom_C _ _ _
set_option linter.uppercaseLean3 false in
#align mv_polynomial.expand_C MvPolynomial.expand_C
@[simp]
theorem expand_X (p : ℕ) (i : σ) : expand p (X i : MvPolynomial σ R) = X i ^ p :=
eval₂Hom_X' _ _ _
set_option linter.uppercaseLean3 false in
#align mv_polynomial.expand_X MvPolynomial.expand_X
@[simp]
theorem expand_monomial (p : ℕ) (d : σ →₀ ℕ) (r : R) :
expand p (monomial d r) = C r * ∏ i ∈ d.support, (X i ^ p) ^ d i :=
bind₁_monomial _ _ _
#align mv_polynomial.expand_monomial MvPolynomial.expand_monomial
theorem expand_one_apply (f : MvPolynomial σ R) : expand 1 f = f := by
simp only [expand, pow_one, eval₂Hom_eq_bind₂, bind₂_C_left, RingHom.toMonoidHom_eq_coe,
RingHom.coe_monoidHom_id, AlgHom.coe_mk, RingHom.coe_mk, MonoidHom.id_apply, RingHom.id_apply]
#align mv_polynomial.expand_one_apply MvPolynomial.expand_one_apply
@[simp]
theorem expand_one : expand 1 = AlgHom.id R (MvPolynomial σ R) := by
ext1 f
rw [expand_one_apply, AlgHom.id_apply]
#align mv_polynomial.expand_one MvPolynomial.expand_one
theorem expand_comp_bind₁ (p : ℕ) (f : σ → MvPolynomial τ R) :
(expand p).comp (bind₁ f) = bind₁ fun i ↦ expand p (f i) := by
apply algHom_ext
intro i
simp only [AlgHom.comp_apply, bind₁_X_right]
#align mv_polynomial.expand_comp_bind₁ MvPolynomial.expand_comp_bind₁
theorem expand_bind₁ (p : ℕ) (f : σ → MvPolynomial τ R) (φ : MvPolynomial σ R) :
expand p (bind₁ f φ) = bind₁ (fun i ↦ expand p (f i)) φ := by
rw [← AlgHom.comp_apply, expand_comp_bind₁]
#align mv_polynomial.expand_bind₁ MvPolynomial.expand_bind₁
@[simp]
| Mathlib/Algebra/MvPolynomial/Expand.lean | 77 | 78 | theorem map_expand (f : R →+* S) (p : ℕ) (φ : MvPolynomial σ R) :
map f (expand p φ) = expand p (map f φ) := by | simp [expand, map_bind₁]
|
import Mathlib.Topology.Order.Basic
import Mathlib.Data.Set.Pointwise.Basic
open Set Filter TopologicalSpace Topology Function
open OrderDual (toDual ofDual)
variable {α β γ : Type*}
section LinearOrder
variable [TopologicalSpace α] [LinearOrder α]
section LinearOrderedAddCommGroup
variable [TopologicalSpace α] [LinearOrderedAddCommGroup α] [OrderTopology α]
variable {l : Filter β} {f g : β → α}
theorem nhds_eq_iInf_abs_sub (a : α) : 𝓝 a = ⨅ r > 0, 𝓟 { b | |a - b| < r } := by
simp only [nhds_eq_order, abs_lt, setOf_and, ← inf_principal, iInf_inf_eq]
refine (congr_arg₂ _ ?_ ?_).trans (inf_comm ..)
· refine (Equiv.subLeft a).iInf_congr fun x => ?_; simp [Ioi]
· refine (Equiv.subRight a).iInf_congr fun x => ?_; simp [Iio]
#align nhds_eq_infi_abs_sub nhds_eq_iInf_abs_sub
theorem orderTopology_of_nhds_abs {α : Type*} [TopologicalSpace α] [LinearOrderedAddCommGroup α]
(h_nhds : ∀ a : α, 𝓝 a = ⨅ r > 0, 𝓟 { b | |a - b| < r }) : OrderTopology α := by
refine ⟨TopologicalSpace.ext_nhds fun a => ?_⟩
rw [h_nhds]
letI := Preorder.topology α; letI : OrderTopology α := ⟨rfl⟩
exact (nhds_eq_iInf_abs_sub a).symm
#align order_topology_of_nhds_abs orderTopology_of_nhds_abs
theorem LinearOrderedAddCommGroup.tendsto_nhds {x : Filter β} {a : α} :
Tendsto f x (𝓝 a) ↔ ∀ ε > (0 : α), ∀ᶠ b in x, |f b - a| < ε := by
simp [nhds_eq_iInf_abs_sub, abs_sub_comm a]
#align linear_ordered_add_comm_group.tendsto_nhds LinearOrderedAddCommGroup.tendsto_nhds
theorem eventually_abs_sub_lt (a : α) {ε : α} (hε : 0 < ε) : ∀ᶠ x in 𝓝 a, |x - a| < ε :=
(nhds_eq_iInf_abs_sub a).symm ▸
mem_iInf_of_mem ε (mem_iInf_of_mem hε <| by simp only [abs_sub_comm, mem_principal_self])
#align eventually_abs_sub_lt eventually_abs_sub_lt
theorem Filter.Tendsto.add_atTop {C : α} (hf : Tendsto f l (𝓝 C)) (hg : Tendsto g l atTop) :
Tendsto (fun x => f x + g x) l atTop := by
nontriviality α
obtain ⟨C', hC'⟩ : ∃ C', C' < C := exists_lt C
refine tendsto_atTop_add_left_of_le' _ C' ?_ hg
exact (hf.eventually (lt_mem_nhds hC')).mono fun x => le_of_lt
#align filter.tendsto.add_at_top Filter.Tendsto.add_atTop
theorem Filter.Tendsto.add_atBot {C : α} (hf : Tendsto f l (𝓝 C)) (hg : Tendsto g l atBot) :
Tendsto (fun x => f x + g x) l atBot :=
Filter.Tendsto.add_atTop (α := αᵒᵈ) hf hg
#align filter.tendsto.add_at_bot Filter.Tendsto.add_atBot
theorem Filter.Tendsto.atTop_add {C : α} (hf : Tendsto f l atTop) (hg : Tendsto g l (𝓝 C)) :
Tendsto (fun x => f x + g x) l atTop := by
conv in _ + _ => rw [add_comm]
exact hg.add_atTop hf
#align filter.tendsto.at_top_add Filter.Tendsto.atTop_add
| Mathlib/Topology/Order/LeftRightNhds.lean | 362 | 365 | theorem Filter.Tendsto.atBot_add {C : α} (hf : Tendsto f l atBot) (hg : Tendsto g l (𝓝 C)) :
Tendsto (fun x => f x + g x) l atBot := by |
conv in _ + _ => rw [add_comm]
exact hg.add_atBot hf
|
import Mathlib.Algebra.ContinuedFractions.Basic
import Mathlib.Algebra.GroupWithZero.Basic
#align_import algebra.continued_fractions.translations from "leanprover-community/mathlib"@"a7e36e48519ab281320c4d192da6a7b348ce40ad"
namespace GeneralizedContinuedFraction
section WithDivisionRing
variable {K : Type*} {g : GeneralizedContinuedFraction K} {n : ℕ} [DivisionRing K]
theorem nth_cont_eq_succ_nth_cont_aux : g.continuants n = g.continuantsAux (n + 1) :=
rfl
#align generalized_continued_fraction.nth_cont_eq_succ_nth_cont_aux GeneralizedContinuedFraction.nth_cont_eq_succ_nth_cont_aux
theorem num_eq_conts_a : g.numerators n = (g.continuants n).a :=
rfl
#align generalized_continued_fraction.num_eq_conts_a GeneralizedContinuedFraction.num_eq_conts_a
theorem denom_eq_conts_b : g.denominators n = (g.continuants n).b :=
rfl
#align generalized_continued_fraction.denom_eq_conts_b GeneralizedContinuedFraction.denom_eq_conts_b
theorem convergent_eq_num_div_denom : g.convergents n = g.numerators n / g.denominators n :=
rfl
#align generalized_continued_fraction.convergent_eq_num_div_denom GeneralizedContinuedFraction.convergent_eq_num_div_denom
theorem convergent_eq_conts_a_div_conts_b :
g.convergents n = (g.continuants n).a / (g.continuants n).b :=
rfl
#align generalized_continued_fraction.convergent_eq_conts_a_div_conts_b GeneralizedContinuedFraction.convergent_eq_conts_a_div_conts_b
theorem exists_conts_a_of_num {A : K} (nth_num_eq : g.numerators n = A) :
∃ conts, g.continuants n = conts ∧ conts.a = A := by simpa
#align generalized_continued_fraction.exists_conts_a_of_num GeneralizedContinuedFraction.exists_conts_a_of_num
theorem exists_conts_b_of_denom {B : K} (nth_denom_eq : g.denominators n = B) :
∃ conts, g.continuants n = conts ∧ conts.b = B := by simpa
#align generalized_continued_fraction.exists_conts_b_of_denom GeneralizedContinuedFraction.exists_conts_b_of_denom
@[simp]
theorem zeroth_continuant_aux_eq_one_zero : g.continuantsAux 0 = ⟨1, 0⟩ :=
rfl
#align generalized_continued_fraction.zeroth_continuant_aux_eq_one_zero GeneralizedContinuedFraction.zeroth_continuant_aux_eq_one_zero
@[simp]
theorem first_continuant_aux_eq_h_one : g.continuantsAux 1 = ⟨g.h, 1⟩ :=
rfl
#align generalized_continued_fraction.first_continuant_aux_eq_h_one GeneralizedContinuedFraction.first_continuant_aux_eq_h_one
@[simp]
theorem zeroth_continuant_eq_h_one : g.continuants 0 = ⟨g.h, 1⟩ :=
rfl
#align generalized_continued_fraction.zeroth_continuant_eq_h_one GeneralizedContinuedFraction.zeroth_continuant_eq_h_one
@[simp]
theorem zeroth_numerator_eq_h : g.numerators 0 = g.h :=
rfl
#align generalized_continued_fraction.zeroth_numerator_eq_h GeneralizedContinuedFraction.zeroth_numerator_eq_h
@[simp]
theorem zeroth_denominator_eq_one : g.denominators 0 = 1 :=
rfl
#align generalized_continued_fraction.zeroth_denominator_eq_one GeneralizedContinuedFraction.zeroth_denominator_eq_one
@[simp]
theorem zeroth_convergent_eq_h : g.convergents 0 = g.h := by
simp [convergent_eq_num_div_denom, num_eq_conts_a, denom_eq_conts_b, div_one]
#align generalized_continued_fraction.zeroth_convergent_eq_h GeneralizedContinuedFraction.zeroth_convergent_eq_h
theorem second_continuant_aux_eq {gp : Pair K} (zeroth_s_eq : g.s.get? 0 = some gp) :
g.continuantsAux 2 = ⟨gp.b * g.h + gp.a, gp.b⟩ := by
simp [zeroth_s_eq, continuantsAux, nextContinuants, nextDenominator, nextNumerator]
#align generalized_continued_fraction.second_continuant_aux_eq GeneralizedContinuedFraction.second_continuant_aux_eq
| Mathlib/Algebra/ContinuedFractions/Translations.lean | 155 | 159 | theorem first_continuant_eq {gp : Pair K} (zeroth_s_eq : g.s.get? 0 = some gp) :
g.continuants 1 = ⟨gp.b * g.h + gp.a, gp.b⟩ := by |
simp [nth_cont_eq_succ_nth_cont_aux]
-- Porting note (#10959): simp used to work here, but now it can't figure out that 1 + 1 = 2
convert second_continuant_aux_eq zeroth_s_eq
|
import Mathlib.Algebra.Order.Ring.Rat
import Mathlib.Tactic.NormNum.Inv
import Mathlib.Tactic.NormNum.Pow
import Mathlib.Util.AtomM
set_option autoImplicit true
namespace Mathlib.Tactic
namespace Ring
open Mathlib.Meta Qq NormNum Lean.Meta AtomM
open Lean (MetaM Expr mkRawNatLit)
def instCommSemiringNat : CommSemiring ℕ := inferInstance
def sℕ : Q(CommSemiring ℕ) := q(instCommSemiringNat)
-- In this file, we would like to use multi-character auto-implicits.
set_option relaxedAutoImplicit true
mutual
inductive ExBase : ∀ {α : Q(Type u)}, Q(CommSemiring $α) → (e : Q($α)) → Type
| atom (id : ℕ) : ExBase sα e
| sum (_ : ExSum sα e) : ExBase sα e
inductive ExProd : ∀ {α : Q(Type u)}, Q(CommSemiring $α) → (e : Q($α)) → Type
| const (value : ℚ) (hyp : Option Expr := none) : ExProd sα e
| mul {α : Q(Type u)} {sα : Q(CommSemiring $α)} {x : Q($α)} {e : Q(ℕ)} {b : Q($α)} :
ExBase sα x → ExProd sℕ e → ExProd sα b → ExProd sα q($x ^ $e * $b)
inductive ExSum : ∀ {α : Q(Type u)}, Q(CommSemiring $α) → (e : Q($α)) → Type
| zero {α : Q(Type u)} {sα : Q(CommSemiring $α)} : ExSum sα q(0 : $α)
| add {α : Q(Type u)} {sα : Q(CommSemiring $α)} {a b : Q($α)} :
ExProd sα a → ExSum sα b → ExSum sα q($a + $b)
end
mutual -- partial only to speed up compilation
partial def ExBase.eq : ExBase sα a → ExBase sα b → Bool
| .atom i, .atom j => i == j
| .sum a, .sum b => a.eq b
| _, _ => false
@[inherit_doc ExBase.eq]
partial def ExProd.eq : ExProd sα a → ExProd sα b → Bool
| .const i _, .const j _ => i == j
| .mul a₁ a₂ a₃, .mul b₁ b₂ b₃ => a₁.eq b₁ && a₂.eq b₂ && a₃.eq b₃
| _, _ => false
@[inherit_doc ExBase.eq]
partial def ExSum.eq : ExSum sα a → ExSum sα b → Bool
| .zero, .zero => true
| .add a₁ a₂, .add b₁ b₂ => a₁.eq b₁ && a₂.eq b₂
| _, _ => false
end
mutual -- partial only to speed up compilation
partial def ExBase.cmp : ExBase sα a → ExBase sα b → Ordering
| .atom i, .atom j => compare i j
| .sum a, .sum b => a.cmp b
| .atom .., .sum .. => .lt
| .sum .., .atom .. => .gt
@[inherit_doc ExBase.cmp]
partial def ExProd.cmp : ExProd sα a → ExProd sα b → Ordering
| .const i _, .const j _ => compare i j
| .mul a₁ a₂ a₃, .mul b₁ b₂ b₃ => (a₁.cmp b₁).then (a₂.cmp b₂) |>.then (a₃.cmp b₃)
| .const _ _, .mul .. => .lt
| .mul .., .const _ _ => .gt
@[inherit_doc ExBase.cmp]
partial def ExSum.cmp : ExSum sα a → ExSum sα b → Ordering
| .zero, .zero => .eq
| .add a₁ a₂, .add b₁ b₂ => (a₁.cmp b₁).then (a₂.cmp b₂)
| .zero, .add .. => .lt
| .add .., .zero => .gt
end
instance : Inhabited (Σ e, (ExBase sα) e) := ⟨default, .atom 0⟩
instance : Inhabited (Σ e, (ExSum sα) e) := ⟨_, .zero⟩
instance : Inhabited (Σ e, (ExProd sα) e) := ⟨default, .const 0 none⟩
mutual
partial def ExBase.cast : ExBase sα a → Σ a, ExBase sβ a
| .atom i => ⟨a, .atom i⟩
| .sum a => let ⟨_, vb⟩ := a.cast; ⟨_, .sum vb⟩
partial def ExProd.cast : ExProd sα a → Σ a, ExProd sβ a
| .const i h => ⟨a, .const i h⟩
| .mul a₁ a₂ a₃ => ⟨_, .mul a₁.cast.2 a₂ a₃.cast.2⟩
partial def ExSum.cast : ExSum sα a → Σ a, ExSum sβ a
| .zero => ⟨_, .zero⟩
| .add a₁ a₂ => ⟨_, .add a₁.cast.2 a₂.cast.2⟩
end
structure Result {α : Q(Type u)} (E : Q($α) → Type) (e : Q($α)) where
expr : Q($α)
val : E expr
proof : Q($e = $expr)
instance [Inhabited (Σ e, E e)] : Inhabited (Result E e) :=
let ⟨e', v⟩ : Σ e, E e := default; ⟨e', v, default⟩
variable {α : Q(Type u)} (sα : Q(CommSemiring $α)) [CommSemiring R]
def ExProd.mkNat (n : ℕ) : (e : Q($α)) × ExProd sα e :=
let lit : Q(ℕ) := mkRawNatLit n
⟨q(($lit).rawCast : $α), .const n none⟩
def ExProd.mkNegNat (_ : Q(Ring $α)) (n : ℕ) : (e : Q($α)) × ExProd sα e :=
let lit : Q(ℕ) := mkRawNatLit n
⟨q((Int.negOfNat $lit).rawCast : $α), .const (-n) none⟩
def ExProd.mkRat (_ : Q(DivisionRing $α)) (q : ℚ) (n : Q(ℤ)) (d : Q(ℕ)) (h : Expr) :
(e : Q($α)) × ExProd sα e :=
⟨q(Rat.rawCast $n $d : $α), .const q h⟩
section
variable {sα}
def ExBase.toProd (va : ExBase sα a) (vb : ExProd sℕ b) :
ExProd sα q($a ^ $b * (nat_lit 1).rawCast) := .mul va vb (.const 1 none)
def ExProd.toSum (v : ExProd sα e) : ExSum sα q($e + 0) := .add v .zero
def ExProd.coeff : ExProd sα e → ℚ
| .const q _ => q
| .mul _ _ v => v.coeff
end
inductive Overlap (e : Q($α)) where
| zero (_ : Q(IsNat $e (nat_lit 0)))
| nonzero (_ : Result (ExProd sα) e)
theorem add_overlap_pf (x : R) (e) (pq_pf : a + b = c) :
x ^ e * a + x ^ e * b = x ^ e * c := by subst_vars; simp [mul_add]
theorem add_overlap_pf_zero (x : R) (e) :
IsNat (a + b) (nat_lit 0) → IsNat (x ^ e * a + x ^ e * b) (nat_lit 0)
| ⟨h⟩ => ⟨by simp [h, ← mul_add]⟩
def evalAddOverlap (va : ExProd sα a) (vb : ExProd sα b) : Option (Overlap sα q($a + $b)) :=
match va, vb with
| .const za ha, .const zb hb => do
let ra := Result.ofRawRat za a ha; let rb := Result.ofRawRat zb b hb
let res ← NormNum.evalAdd.core q($a + $b) q(HAdd.hAdd) a b ra rb
match res with
| .isNat _ (.lit (.natVal 0)) p => pure <| .zero p
| rc =>
let ⟨zc, hc⟩ ← rc.toRatNZ
let ⟨c, pc⟩ := rc.toRawEq
pure <| .nonzero ⟨c, .const zc hc, pc⟩
| .mul (x := a₁) (e := a₂) va₁ va₂ va₃, .mul vb₁ vb₂ vb₃ => do
guard (va₁.eq vb₁ && va₂.eq vb₂)
match ← evalAddOverlap va₃ vb₃ with
| .zero p => pure <| .zero (q(add_overlap_pf_zero $a₁ $a₂ $p) : Expr)
| .nonzero ⟨_, vc, p⟩ =>
pure <| .nonzero ⟨_, .mul va₁ va₂ vc, (q(add_overlap_pf $a₁ $a₂ $p) : Expr)⟩
| _, _ => none
theorem add_pf_zero_add (b : R) : 0 + b = b := by simp
theorem add_pf_add_zero (a : R) : a + 0 = a := by simp
theorem add_pf_add_overlap
(_ : a₁ + b₁ = c₁) (_ : a₂ + b₂ = c₂) : (a₁ + a₂ : R) + (b₁ + b₂) = c₁ + c₂ := by
subst_vars; simp [add_assoc, add_left_comm]
theorem add_pf_add_overlap_zero
(h : IsNat (a₁ + b₁) (nat_lit 0)) (h₄ : a₂ + b₂ = c) : (a₁ + a₂ : R) + (b₁ + b₂) = c := by
subst_vars; rw [add_add_add_comm, h.1, Nat.cast_zero, add_pf_zero_add]
theorem add_pf_add_lt (a₁ : R) (_ : a₂ + b = c) : (a₁ + a₂) + b = a₁ + c := by simp [*, add_assoc]
theorem add_pf_add_gt (b₁ : R) (_ : a + b₂ = c) : a + (b₁ + b₂) = b₁ + c := by
subst_vars; simp [add_left_comm]
partial def evalAdd (va : ExSum sα a) (vb : ExSum sα b) : Result (ExSum sα) q($a + $b) :=
match va, vb with
| .zero, vb => ⟨b, vb, q(add_pf_zero_add $b)⟩
| va, .zero => ⟨a, va, q(add_pf_add_zero $a)⟩
| .add (a := a₁) (b := _a₂) va₁ va₂, .add (a := b₁) (b := _b₂) vb₁ vb₂ =>
match evalAddOverlap sα va₁ vb₁ with
| some (.nonzero ⟨_, vc₁, pc₁⟩) =>
let ⟨_, vc₂, pc₂⟩ := evalAdd va₂ vb₂
⟨_, .add vc₁ vc₂, q(add_pf_add_overlap $pc₁ $pc₂)⟩
| some (.zero pc₁) =>
let ⟨c₂, vc₂, pc₂⟩ := evalAdd va₂ vb₂
⟨c₂, vc₂, q(add_pf_add_overlap_zero $pc₁ $pc₂)⟩
| none =>
if let .lt := va₁.cmp vb₁ then
let ⟨_c, vc, (pc : Q($_a₂ + ($b₁ + $_b₂) = $_c))⟩ := evalAdd va₂ vb
⟨_, .add va₁ vc, q(add_pf_add_lt $a₁ $pc)⟩
else
let ⟨_c, vc, (pc : Q($a₁ + $_a₂ + $_b₂ = $_c))⟩ := evalAdd va vb₂
⟨_, .add vb₁ vc, q(add_pf_add_gt $b₁ $pc)⟩
theorem one_mul (a : R) : (nat_lit 1).rawCast * a = a := by simp [Nat.rawCast]
theorem mul_one (a : R) : a * (nat_lit 1).rawCast = a := by simp [Nat.rawCast]
theorem mul_pf_left (a₁ : R) (a₂) (_ : a₃ * b = c) : (a₁ ^ a₂ * a₃ : R) * b = a₁ ^ a₂ * c := by
subst_vars; rw [mul_assoc]
theorem mul_pf_right (b₁ : R) (b₂) (_ : a * b₃ = c) : a * (b₁ ^ b₂ * b₃) = b₁ ^ b₂ * c := by
subst_vars; rw [mul_left_comm]
theorem mul_pp_pf_overlap (x : R) (_ : ea + eb = e) (_ : a₂ * b₂ = c) :
(x ^ ea * a₂ : R) * (x ^ eb * b₂) = x ^ e * c := by
subst_vars; simp [pow_add, mul_mul_mul_comm]
partial def evalMulProd (va : ExProd sα a) (vb : ExProd sα b) : Result (ExProd sα) q($a * $b) :=
match va, vb with
| .const za ha, .const zb hb =>
if za = 1 then
⟨b, .const zb hb, (q(one_mul $b) : Expr)⟩
else if zb = 1 then
⟨a, .const za ha, (q(mul_one $a) : Expr)⟩
else
let ra := Result.ofRawRat za a ha; let rb := Result.ofRawRat zb b hb
let rc := (NormNum.evalMul.core q($a * $b) q(HMul.hMul) _ _
q(CommSemiring.toSemiring) ra rb).get!
let ⟨zc, hc⟩ := rc.toRatNZ.get!
let ⟨c, pc⟩ := rc.toRawEq
⟨c, .const zc hc, pc⟩
| .mul (x := a₁) (e := a₂) va₁ va₂ va₃, .const _ _ =>
let ⟨_, vc, pc⟩ := evalMulProd va₃ vb
⟨_, .mul va₁ va₂ vc, (q(mul_pf_left $a₁ $a₂ $pc) : Expr)⟩
| .const _ _, .mul (x := b₁) (e := b₂) vb₁ vb₂ vb₃ =>
let ⟨_, vc, pc⟩ := evalMulProd va vb₃
⟨_, .mul vb₁ vb₂ vc, (q(mul_pf_right $b₁ $b₂ $pc) : Expr)⟩
| .mul (x := xa) (e := ea) vxa vea va₂, .mul (x := xb) (e := eb) vxb veb vb₂ => Id.run do
if vxa.eq vxb then
if let some (.nonzero ⟨_, ve, pe⟩) := evalAddOverlap sℕ vea veb then
let ⟨_, vc, pc⟩ := evalMulProd va₂ vb₂
return ⟨_, .mul vxa ve vc, (q(mul_pp_pf_overlap $xa $pe $pc) : Expr)⟩
if let .lt := (vxa.cmp vxb).then (vea.cmp veb) then
let ⟨_, vc, pc⟩ := evalMulProd va₂ vb
⟨_, .mul vxa vea vc, (q(mul_pf_left $xa $ea $pc) : Expr)⟩
else
let ⟨_, vc, pc⟩ := evalMulProd va vb₂
⟨_, .mul vxb veb vc, (q(mul_pf_right $xb $eb $pc) : Expr)⟩
theorem mul_zero (a : R) : a * 0 = 0 := by simp
theorem mul_add (_ : (a : R) * b₁ = c₁) (_ : a * b₂ = c₂) (_ : c₁ + 0 + c₂ = d) :
a * (b₁ + b₂) = d := by subst_vars; simp [_root_.mul_add]
def evalMul₁ (va : ExProd sα a) (vb : ExSum sα b) : Result (ExSum sα) q($a * $b) :=
match vb with
| .zero => ⟨_, .zero, q(mul_zero $a)⟩
| .add vb₁ vb₂ =>
let ⟨_, vc₁, pc₁⟩ := evalMulProd sα va vb₁
let ⟨_, vc₂, pc₂⟩ := evalMul₁ va vb₂
let ⟨_, vd, pd⟩ := evalAdd sα vc₁.toSum vc₂
⟨_, vd, q(mul_add $pc₁ $pc₂ $pd)⟩
theorem zero_mul (b : R) : 0 * b = 0 := by simp
theorem add_mul (_ : (a₁ : R) * b = c₁) (_ : a₂ * b = c₂) (_ : c₁ + c₂ = d) :
(a₁ + a₂) * b = d := by subst_vars; simp [_root_.add_mul]
def evalMul (va : ExSum sα a) (vb : ExSum sα b) : Result (ExSum sα) q($a * $b) :=
match va with
| .zero => ⟨_, .zero, q(zero_mul $b)⟩
| .add va₁ va₂ =>
let ⟨_, vc₁, pc₁⟩ := evalMul₁ sα va₁ vb
let ⟨_, vc₂, pc₂⟩ := evalMul va₂ vb
let ⟨_, vd, pd⟩ := evalAdd sα vc₁ vc₂
⟨_, vd, q(add_mul $pc₁ $pc₂ $pd)⟩
theorem natCast_nat (n) : ((Nat.rawCast n : ℕ) : R) = Nat.rawCast n := by simp
theorem natCast_mul (a₂) (_ : ((a₁ : ℕ) : R) = b₁) (_ : ((a₃ : ℕ) : R) = b₃) :
((a₁ ^ a₂ * a₃ : ℕ) : R) = b₁ ^ a₂ * b₃ := by subst_vars; simp
theorem natCast_zero : ((0 : ℕ) : R) = 0 := Nat.cast_zero
theorem natCast_add (_ : ((a₁ : ℕ) : R) = b₁) (_ : ((a₂ : ℕ) : R) = b₂) :
((a₁ + a₂ : ℕ) : R) = b₁ + b₂ := by subst_vars; simp
mutual
partial def ExBase.evalNatCast (va : ExBase sℕ a) : AtomM (Result (ExBase sα) q($a)) :=
match va with
| .atom _ => do
let a' : Q($α) := q($a)
let i ← addAtom a'
pure ⟨a', ExBase.atom i, (q(Eq.refl $a') : Expr)⟩
| .sum va => do
let ⟨_, vc, p⟩ ← va.evalNatCast
pure ⟨_, .sum vc, p⟩
partial def ExProd.evalNatCast (va : ExProd sℕ a) : AtomM (Result (ExProd sα) q($a)) :=
match va with
| .const c hc =>
have n : Q(ℕ) := a.appArg!
pure ⟨q(Nat.rawCast $n), .const c hc, (q(natCast_nat (R := $α) $n) : Expr)⟩
| .mul (e := a₂) va₁ va₂ va₃ => do
let ⟨_, vb₁, pb₁⟩ ← va₁.evalNatCast
let ⟨_, vb₃, pb₃⟩ ← va₃.evalNatCast
pure ⟨_, .mul vb₁ va₂ vb₃, q(natCast_mul $a₂ $pb₁ $pb₃)⟩
partial def ExSum.evalNatCast (va : ExSum sℕ a) : AtomM (Result (ExSum sα) q($a)) :=
match va with
| .zero => pure ⟨_, .zero, q(natCast_zero (R := $α))⟩
| .add va₁ va₂ => do
let ⟨_, vb₁, pb₁⟩ ← va₁.evalNatCast
let ⟨_, vb₂, pb₂⟩ ← va₂.evalNatCast
pure ⟨_, .add vb₁ vb₂, q(natCast_add $pb₁ $pb₂)⟩
end
theorem smul_nat (_ : (a * b : ℕ) = c) : a • b = c := by subst_vars; simp
theorem smul_eq_cast (_ : ((a : ℕ) : R) = a') (_ : a' * b = c) : a • b = c := by subst_vars; simp
def evalNSMul (va : ExSum sℕ a) (vb : ExSum sα b) : AtomM (Result (ExSum sα) q($a • $b)) := do
if ← isDefEq sα sℕ then
let ⟨_, va'⟩ := va.cast
have _b : Q(ℕ) := b
let ⟨(_c : Q(ℕ)), vc, (pc : Q($a * $_b = $_c))⟩ := evalMul sα va' vb
pure ⟨_, vc, (q(smul_nat $pc) : Expr)⟩
else
let ⟨_, va', pa'⟩ ← va.evalNatCast sα
let ⟨_, vc, pc⟩ := evalMul sα va' vb
pure ⟨_, vc, (q(smul_eq_cast $pa' $pc) : Expr)⟩
theorem neg_one_mul {R} [Ring R] {a b : R} (_ : (Int.negOfNat (nat_lit 1)).rawCast * a = b) :
-a = b := by subst_vars; simp [Int.negOfNat]
theorem neg_mul {R} [Ring R] (a₁ : R) (a₂) {a₃ b : R}
(_ : -a₃ = b) : -(a₁ ^ a₂ * a₃) = a₁ ^ a₂ * b := by subst_vars; simp
def evalNegProd (rα : Q(Ring $α)) (va : ExProd sα a) : Result (ExProd sα) q(-$a) :=
match va with
| .const za ha =>
let lit : Q(ℕ) := mkRawNatLit 1
let ⟨m1, _⟩ := ExProd.mkNegNat sα rα 1
let rm := Result.isNegNat rα lit (q(IsInt.of_raw $α (.negOfNat $lit)) : Expr)
let ra := Result.ofRawRat za a ha
let rb := (NormNum.evalMul.core q($m1 * $a) q(HMul.hMul) _ _
q(CommSemiring.toSemiring) rm ra).get!
let ⟨zb, hb⟩ := rb.toRatNZ.get!
let ⟨b, (pb : Q((Int.negOfNat (nat_lit 1)).rawCast * $a = $b))⟩ := rb.toRawEq
⟨b, .const zb hb, (q(neg_one_mul (R := $α) $pb) : Expr)⟩
| .mul (x := a₁) (e := a₂) va₁ va₂ va₃ =>
let ⟨_, vb, pb⟩ := evalNegProd rα va₃
⟨_, .mul va₁ va₂ vb, (q(neg_mul $a₁ $a₂ $pb) : Expr)⟩
theorem neg_zero {R} [Ring R] : -(0 : R) = 0 := by simp
theorem neg_add {R} [Ring R] {a₁ a₂ b₁ b₂ : R}
(_ : -a₁ = b₁) (_ : -a₂ = b₂) : -(a₁ + a₂) = b₁ + b₂ := by subst_vars; simp [add_comm]
def evalNeg (rα : Q(Ring $α)) (va : ExSum sα a) : Result (ExSum sα) q(-$a) :=
match va with
| .zero => ⟨_, .zero, (q(neg_zero (R := $α)) : Expr)⟩
| .add va₁ va₂ =>
let ⟨_, vb₁, pb₁⟩ := evalNegProd sα rα va₁
let ⟨_, vb₂, pb₂⟩ := evalNeg rα va₂
⟨_, .add vb₁ vb₂, (q(neg_add $pb₁ $pb₂) : Expr)⟩
| Mathlib/Tactic/Ring/Basic.lean | 574 | 575 | theorem sub_pf {R} [Ring R] {a b c d : R}
(_ : -b = c) (_ : a + c = d) : a - b = d := by | subst_vars; simp [sub_eq_add_neg]
|
import Batteries.Control.ForInStep.Lemmas
import Batteries.Data.List.Basic
import Batteries.Tactic.Init
import Batteries.Tactic.Alias
namespace List
open Nat
@[simp] theorem mem_toArray {a : α} {l : List α} : a ∈ l.toArray ↔ a ∈ l := by
simp [Array.mem_def]
@[simp]
theorem drop_one : ∀ l : List α, drop 1 l = tail l
| [] | _ :: _ => rfl
theorem zipWith_distrib_tail : (zipWith f l l').tail = zipWith f l.tail l'.tail := by
rw [← drop_one]; simp [zipWith_distrib_drop]
theorem subset_def {l₁ l₂ : List α} : l₁ ⊆ l₂ ↔ ∀ {a : α}, a ∈ l₁ → a ∈ l₂ := .rfl
@[simp] theorem nil_subset (l : List α) : [] ⊆ l := nofun
@[simp] theorem Subset.refl (l : List α) : l ⊆ l := fun _ i => i
theorem Subset.trans {l₁ l₂ l₃ : List α} (h₁ : l₁ ⊆ l₂) (h₂ : l₂ ⊆ l₃) : l₁ ⊆ l₃ :=
fun _ i => h₂ (h₁ i)
instance : Trans (Membership.mem : α → List α → Prop) Subset Membership.mem :=
⟨fun h₁ h₂ => h₂ h₁⟩
instance : Trans (Subset : List α → List α → Prop) Subset Subset :=
⟨Subset.trans⟩
@[simp] theorem subset_cons (a : α) (l : List α) : l ⊆ a :: l := fun _ => Mem.tail _
theorem subset_of_cons_subset {a : α} {l₁ l₂ : List α} : a :: l₁ ⊆ l₂ → l₁ ⊆ l₂ :=
fun s _ i => s (mem_cons_of_mem _ i)
theorem subset_cons_of_subset (a : α) {l₁ l₂ : List α} : l₁ ⊆ l₂ → l₁ ⊆ a :: l₂ :=
fun s _ i => .tail _ (s i)
theorem cons_subset_cons {l₁ l₂ : List α} (a : α) (s : l₁ ⊆ l₂) : a :: l₁ ⊆ a :: l₂ :=
fun _ => by simp only [mem_cons]; exact Or.imp_right (@s _)
@[simp] theorem subset_append_left (l₁ l₂ : List α) : l₁ ⊆ l₁ ++ l₂ := fun _ => mem_append_left _
@[simp] theorem subset_append_right (l₁ l₂ : List α) : l₂ ⊆ l₁ ++ l₂ := fun _ => mem_append_right _
theorem subset_append_of_subset_left (l₂ : List α) : l ⊆ l₁ → l ⊆ l₁ ++ l₂ :=
fun s => Subset.trans s <| subset_append_left _ _
theorem subset_append_of_subset_right (l₁ : List α) : l ⊆ l₂ → l ⊆ l₁ ++ l₂ :=
fun s => Subset.trans s <| subset_append_right _ _
@[simp] theorem cons_subset : a :: l ⊆ m ↔ a ∈ m ∧ l ⊆ m := by
simp only [subset_def, mem_cons, or_imp, forall_and, forall_eq]
@[simp] theorem append_subset {l₁ l₂ l : List α} :
l₁ ++ l₂ ⊆ l ↔ l₁ ⊆ l ∧ l₂ ⊆ l := by simp [subset_def, or_imp, forall_and]
theorem subset_nil {l : List α} : l ⊆ [] ↔ l = [] :=
⟨fun h => match l with | [] => rfl | _::_ => (nomatch h (.head ..)), fun | rfl => Subset.refl _⟩
theorem map_subset {l₁ l₂ : List α} (f : α → β) (H : l₁ ⊆ l₂) : map f l₁ ⊆ map f l₂ :=
fun x => by simp only [mem_map]; exact .imp fun a => .imp_left (@H _)
@[simp] theorem nil_sublist : ∀ l : List α, [] <+ l
| [] => .slnil
| a :: l => (nil_sublist l).cons a
@[simp] theorem Sublist.refl : ∀ l : List α, l <+ l
| [] => .slnil
| a :: l => (Sublist.refl l).cons₂ a
theorem Sublist.trans {l₁ l₂ l₃ : List α} (h₁ : l₁ <+ l₂) (h₂ : l₂ <+ l₃) : l₁ <+ l₃ := by
induction h₂ generalizing l₁ with
| slnil => exact h₁
| cons _ _ IH => exact (IH h₁).cons _
| @cons₂ l₂ _ a _ IH =>
generalize e : a :: l₂ = l₂'
match e ▸ h₁ with
| .slnil => apply nil_sublist
| .cons a' h₁' => cases e; apply (IH h₁').cons
| .cons₂ a' h₁' => cases e; apply (IH h₁').cons₂
instance : Trans (@Sublist α) Sublist Sublist := ⟨Sublist.trans⟩
@[simp] theorem sublist_cons (a : α) (l : List α) : l <+ a :: l := (Sublist.refl l).cons _
theorem sublist_of_cons_sublist : a :: l₁ <+ l₂ → l₁ <+ l₂ :=
(sublist_cons a l₁).trans
@[simp] theorem sublist_append_left : ∀ l₁ l₂ : List α, l₁ <+ l₁ ++ l₂
| [], _ => nil_sublist _
| _ :: l₁, l₂ => (sublist_append_left l₁ l₂).cons₂ _
@[simp] theorem sublist_append_right : ∀ l₁ l₂ : List α, l₂ <+ l₁ ++ l₂
| [], _ => Sublist.refl _
| _ :: l₁, l₂ => (sublist_append_right l₁ l₂).cons _
theorem sublist_append_of_sublist_left (s : l <+ l₁) : l <+ l₁ ++ l₂ :=
s.trans <| sublist_append_left ..
theorem sublist_append_of_sublist_right (s : l <+ l₂) : l <+ l₁ ++ l₂ :=
s.trans <| sublist_append_right ..
@[simp]
theorem cons_sublist_cons : a :: l₁ <+ a :: l₂ ↔ l₁ <+ l₂ :=
⟨fun | .cons _ s => sublist_of_cons_sublist s | .cons₂ _ s => s, .cons₂ _⟩
@[simp] theorem append_sublist_append_left : ∀ l, l ++ l₁ <+ l ++ l₂ ↔ l₁ <+ l₂
| [] => Iff.rfl
| _ :: l => cons_sublist_cons.trans (append_sublist_append_left l)
theorem Sublist.append_left : l₁ <+ l₂ → ∀ l, l ++ l₁ <+ l ++ l₂ :=
fun h l => (append_sublist_append_left l).mpr h
theorem Sublist.append_right : l₁ <+ l₂ → ∀ l, l₁ ++ l <+ l₂ ++ l
| .slnil, _ => Sublist.refl _
| .cons _ h, _ => (h.append_right _).cons _
| .cons₂ _ h, _ => (h.append_right _).cons₂ _
theorem sublist_or_mem_of_sublist (h : l <+ l₁ ++ a :: l₂) : l <+ l₁ ++ l₂ ∨ a ∈ l := by
induction l₁ generalizing l with
| nil => match h with
| .cons _ h => exact .inl h
| .cons₂ _ h => exact .inr (.head ..)
| cons b l₁ IH =>
match h with
| .cons _ h => exact (IH h).imp_left (Sublist.cons _)
| .cons₂ _ h => exact (IH h).imp (Sublist.cons₂ _) (.tail _)
theorem Sublist.reverse : l₁ <+ l₂ → l₁.reverse <+ l₂.reverse
| .slnil => Sublist.refl _
| .cons _ h => by rw [reverse_cons]; exact sublist_append_of_sublist_left h.reverse
| .cons₂ _ h => by rw [reverse_cons, reverse_cons]; exact h.reverse.append_right _
@[simp] theorem reverse_sublist : l₁.reverse <+ l₂.reverse ↔ l₁ <+ l₂ :=
⟨fun h => l₁.reverse_reverse ▸ l₂.reverse_reverse ▸ h.reverse, Sublist.reverse⟩
@[simp] theorem append_sublist_append_right (l) : l₁ ++ l <+ l₂ ++ l ↔ l₁ <+ l₂ :=
⟨fun h => by
have := h.reverse
simp only [reverse_append, append_sublist_append_left, reverse_sublist] at this
exact this,
fun h => h.append_right l⟩
theorem Sublist.append (hl : l₁ <+ l₂) (hr : r₁ <+ r₂) : l₁ ++ r₁ <+ l₂ ++ r₂ :=
(hl.append_right _).trans ((append_sublist_append_left _).2 hr)
theorem Sublist.subset : l₁ <+ l₂ → l₁ ⊆ l₂
| .slnil, _, h => h
| .cons _ s, _, h => .tail _ (s.subset h)
| .cons₂ .., _, .head .. => .head ..
| .cons₂ _ s, _, .tail _ h => .tail _ (s.subset h)
instance : Trans (@Sublist α) Subset Subset :=
⟨fun h₁ h₂ => trans h₁.subset h₂⟩
instance : Trans Subset (@Sublist α) Subset :=
⟨fun h₁ h₂ => trans h₁ h₂.subset⟩
instance : Trans (Membership.mem : α → List α → Prop) Sublist Membership.mem :=
⟨fun h₁ h₂ => h₂.subset h₁⟩
theorem Sublist.length_le : l₁ <+ l₂ → length l₁ ≤ length l₂
| .slnil => Nat.le_refl 0
| .cons _l s => le_succ_of_le (length_le s)
| .cons₂ _ s => succ_le_succ (length_le s)
@[simp] theorem sublist_nil {l : List α} : l <+ [] ↔ l = [] :=
⟨fun s => subset_nil.1 s.subset, fun H => H ▸ Sublist.refl _⟩
theorem Sublist.eq_of_length : l₁ <+ l₂ → length l₁ = length l₂ → l₁ = l₂
| .slnil, _ => rfl
| .cons a s, h => nomatch Nat.not_lt.2 s.length_le (h ▸ lt_succ_self _)
| .cons₂ a s, h => by rw [s.eq_of_length (succ.inj h)]
theorem Sublist.eq_of_length_le (s : l₁ <+ l₂) (h : length l₂ ≤ length l₁) : l₁ = l₂ :=
s.eq_of_length <| Nat.le_antisymm s.length_le h
@[simp] theorem singleton_sublist {a : α} {l} : [a] <+ l ↔ a ∈ l := by
refine ⟨fun h => h.subset (mem_singleton_self _), fun h => ?_⟩
obtain ⟨_, _, rfl⟩ := append_of_mem h
exact ((nil_sublist _).cons₂ _).trans (sublist_append_right ..)
@[simp] theorem replicate_sublist_replicate {m n} (a : α) :
replicate m a <+ replicate n a ↔ m ≤ n := by
refine ⟨fun h => ?_, fun h => ?_⟩
· have := h.length_le; simp only [length_replicate] at this ⊢; exact this
· induction h with
| refl => apply Sublist.refl
| step => simp [*, replicate, Sublist.cons]
theorem isSublist_iff_sublist [BEq α] [LawfulBEq α] {l₁ l₂ : List α} :
l₁.isSublist l₂ ↔ l₁ <+ l₂ := by
cases l₁ <;> cases l₂ <;> simp [isSublist]
case cons.cons hd₁ tl₁ hd₂ tl₂ =>
if h_eq : hd₁ = hd₂ then
simp [h_eq, cons_sublist_cons, isSublist_iff_sublist]
else
simp only [beq_iff_eq, h_eq]
constructor
· intro h_sub
apply Sublist.cons
exact isSublist_iff_sublist.mp h_sub
· intro h_sub
cases h_sub
case cons h_sub =>
exact isSublist_iff_sublist.mpr h_sub
case cons₂ =>
contradiction
instance [DecidableEq α] (l₁ l₂ : List α) : Decidable (l₁ <+ l₂) :=
decidable_of_iff (l₁.isSublist l₂) isSublist_iff_sublist
theorem tail_eq_tailD (l) : @tail α l = tailD l [] := by cases l <;> rfl
theorem tail_eq_tail? (l) : @tail α l = (tail? l).getD [] := by simp [tail_eq_tailD]
@[simp] theorem next?_nil : @next? α [] = none := rfl
@[simp] theorem next?_cons (a l) : @next? α (a :: l) = some (a, l) := rfl
theorem get_eq_iff : List.get l n = x ↔ l.get? n.1 = some x := by simp [get?_eq_some]
theorem get?_inj
(h₀ : i < xs.length) (h₁ : Nodup xs) (h₂ : xs.get? i = xs.get? j) : i = j := by
induction xs generalizing i j with
| nil => cases h₀
| cons x xs ih =>
match i, j with
| 0, 0 => rfl
| i+1, j+1 => simp; cases h₁ with
| cons ha h₁ => exact ih (Nat.lt_of_succ_lt_succ h₀) h₁ h₂
| i+1, 0 => ?_ | 0, j+1 => ?_
all_goals
simp at h₂
cases h₁; rename_i h' h
have := h x ?_ rfl; cases this
rw [mem_iff_get?]
exact ⟨_, h₂⟩; exact ⟨_ , h₂.symm⟩
theorem tail_drop (l : List α) (n : Nat) : (l.drop n).tail = l.drop (n + 1) := by
induction l generalizing n with
| nil => simp
| cons hd tl hl =>
cases n
· simp
· simp [hl]
@[simp] theorem modifyNth_nil (f : α → α) (n) : [].modifyNth f n = [] := by cases n <;> rfl
@[simp] theorem modifyNth_zero_cons (f : α → α) (a : α) (l : List α) :
(a :: l).modifyNth f 0 = f a :: l := rfl
@[simp] theorem modifyNth_succ_cons (f : α → α) (a : α) (l : List α) (n) :
(a :: l).modifyNth f (n + 1) = a :: l.modifyNth f n := by rfl
theorem modifyNthTail_id : ∀ n (l : List α), l.modifyNthTail id n = l
| 0, _ => rfl
| _+1, [] => rfl
| n+1, a :: l => congrArg (cons a) (modifyNthTail_id n l)
theorem eraseIdx_eq_modifyNthTail : ∀ n (l : List α), eraseIdx l n = modifyNthTail tail n l
| 0, l => by cases l <;> rfl
| n+1, [] => rfl
| n+1, a :: l => congrArg (cons _) (eraseIdx_eq_modifyNthTail _ _)
@[deprecated] alias removeNth_eq_nth_tail := eraseIdx_eq_modifyNthTail
theorem get?_modifyNth (f : α → α) :
∀ n (l : List α) m, (modifyNth f n l).get? m = (fun a => if n = m then f a else a) <$> l.get? m
| n, l, 0 => by cases l <;> cases n <;> rfl
| n, [], _+1 => by cases n <;> rfl
| 0, _ :: l, m+1 => by cases h : l.get? m <;> simp [h, modifyNth, m.succ_ne_zero.symm]
| n+1, a :: l, m+1 =>
(get?_modifyNth f n l m).trans <| by
cases h' : l.get? m <;> by_cases h : n = m <;>
simp [h, if_pos, if_neg, Option.map, mt Nat.succ.inj, not_false_iff, h']
theorem modifyNthTail_length (f : List α → List α) (H : ∀ l, length (f l) = length l) :
∀ n l, length (modifyNthTail f n l) = length l
| 0, _ => H _
| _+1, [] => rfl
| _+1, _ :: _ => congrArg (·+1) (modifyNthTail_length _ H _ _)
theorem modifyNthTail_add (f : List α → List α) (n) (l₁ l₂ : List α) :
modifyNthTail f (l₁.length + n) (l₁ ++ l₂) = l₁ ++ modifyNthTail f n l₂ := by
induction l₁ <;> simp [*, Nat.succ_add]
theorem exists_of_modifyNthTail (f : List α → List α) {n} {l : List α} (h : n ≤ l.length) :
∃ l₁ l₂, l = l₁ ++ l₂ ∧ l₁.length = n ∧ modifyNthTail f n l = l₁ ++ f l₂ :=
have ⟨_, _, eq, hl⟩ : ∃ l₁ l₂, l = l₁ ++ l₂ ∧ l₁.length = n :=
⟨_, _, (take_append_drop n l).symm, length_take_of_le h⟩
⟨_, _, eq, hl, hl ▸ eq ▸ modifyNthTail_add (n := 0) ..⟩
@[simp] theorem modify_get?_length (f : α → α) : ∀ n l, length (modifyNth f n l) = length l :=
modifyNthTail_length _ fun l => by cases l <;> rfl
@[simp] theorem get?_modifyNth_eq (f : α → α) (n) (l : List α) :
(modifyNth f n l).get? n = f <$> l.get? n := by
simp only [get?_modifyNth, if_pos]
@[simp] theorem get?_modifyNth_ne (f : α → α) {m n} (l : List α) (h : m ≠ n) :
(modifyNth f m l).get? n = l.get? n := by
simp only [get?_modifyNth, if_neg h, id_map']
theorem exists_of_modifyNth (f : α → α) {n} {l : List α} (h : n < l.length) :
∃ l₁ a l₂, l = l₁ ++ a :: l₂ ∧ l₁.length = n ∧ modifyNth f n l = l₁ ++ f a :: l₂ :=
match exists_of_modifyNthTail _ (Nat.le_of_lt h) with
| ⟨_, _::_, eq, hl, H⟩ => ⟨_, _, _, eq, hl, H⟩
| ⟨_, [], eq, hl, _⟩ => nomatch Nat.ne_of_gt h (eq ▸ append_nil _ ▸ hl)
theorem modifyNthTail_eq_take_drop (f : List α → List α) (H : f [] = []) :
∀ n l, modifyNthTail f n l = take n l ++ f (drop n l)
| 0, _ => rfl
| _ + 1, [] => H.symm
| n + 1, b :: l => congrArg (cons b) (modifyNthTail_eq_take_drop f H n l)
theorem modifyNth_eq_take_drop (f : α → α) :
∀ n l, modifyNth f n l = take n l ++ modifyHead f (drop n l) :=
modifyNthTail_eq_take_drop _ rfl
theorem modifyNth_eq_take_cons_drop (f : α → α) {n l} (h) :
modifyNth f n l = take n l ++ f (get l ⟨n, h⟩) :: drop (n + 1) l := by
rw [modifyNth_eq_take_drop, drop_eq_get_cons h]; rfl
theorem set_eq_modifyNth (a : α) : ∀ n (l : List α), set l n a = modifyNth (fun _ => a) n l
| 0, l => by cases l <;> rfl
| n+1, [] => rfl
| n+1, b :: l => congrArg (cons _) (set_eq_modifyNth _ _ _)
theorem set_eq_take_cons_drop (a : α) {n l} (h : n < length l) :
set l n a = take n l ++ a :: drop (n + 1) l := by
rw [set_eq_modifyNth, modifyNth_eq_take_cons_drop _ h]
theorem modifyNth_eq_set_get? (f : α → α) :
∀ n (l : List α), l.modifyNth f n = ((fun a => l.set n (f a)) <$> l.get? n).getD l
| 0, l => by cases l <;> rfl
| n+1, [] => rfl
| n+1, b :: l =>
(congrArg (cons _) (modifyNth_eq_set_get? ..)).trans <| by cases h : l.get? n <;> simp [h]
theorem modifyNth_eq_set_get (f : α → α) {n} {l : List α} (h) :
l.modifyNth f n = l.set n (f (l.get ⟨n, h⟩)) := by
rw [modifyNth_eq_set_get?, get?_eq_get h]; rfl
theorem exists_of_set {l : List α} (h : n < l.length) :
∃ l₁ a l₂, l = l₁ ++ a :: l₂ ∧ l₁.length = n ∧ l.set n a' = l₁ ++ a' :: l₂ := by
rw [set_eq_modifyNth]; exact exists_of_modifyNth _ h
theorem exists_of_set' {l : List α} (h : n < l.length) :
∃ l₁ l₂, l = l₁ ++ l.get ⟨n, h⟩ :: l₂ ∧ l₁.length = n ∧ l.set n a' = l₁ ++ a' :: l₂ :=
have ⟨_, _, _, h₁, h₂, h₃⟩ := exists_of_set h; ⟨_, _, get_of_append h₁ h₂ ▸ h₁, h₂, h₃⟩
@[simp]
theorem get?_set_eq (a : α) (n) (l : List α) : (set l n a).get? n = (fun _ => a) <$> l.get? n := by
simp only [set_eq_modifyNth, get?_modifyNth_eq]
theorem get?_set_eq_of_lt (a : α) {n} {l : List α} (h : n < length l) :
(set l n a).get? n = some a := by rw [get?_set_eq, get?_eq_get h]; rfl
@[simp]
theorem get?_set_ne (a : α) {m n} (l : List α) (h : m ≠ n) : (set l m a).get? n = l.get? n := by
simp only [set_eq_modifyNth, get?_modifyNth_ne _ _ h]
theorem get?_set (a : α) {m n} (l : List α) :
(set l m a).get? n = if m = n then (fun _ => a) <$> l.get? n else l.get? n := by
by_cases m = n <;> simp [*, get?_set_eq, get?_set_ne]
theorem get?_set_of_lt (a : α) {m n} (l : List α) (h : n < length l) :
(set l m a).get? n = if m = n then some a else l.get? n := by
simp [get?_set, get?_eq_get h]
theorem get?_set_of_lt' (a : α) {m n} (l : List α) (h : m < length l) :
(set l m a).get? n = if m = n then some a else l.get? n := by
simp [get?_set]; split <;> subst_vars <;> simp [*, get?_eq_get h]
theorem drop_set_of_lt (a : α) {n m : Nat} (l : List α) (h : n < m) :
(l.set n a).drop m = l.drop m :=
List.ext fun i => by rw [get?_drop, get?_drop, get?_set_ne _ _ (by omega)]
theorem take_set_of_lt (a : α) {n m : Nat} (l : List α) (h : m < n) :
(l.set n a).take m = l.take m :=
List.ext fun i => by
rw [get?_take_eq_if, get?_take_eq_if]
split
· next h' => rw [get?_set_ne _ _ (by omega)]
· rfl
theorem length_eraseIdx : ∀ {l i}, i < length l → length (@eraseIdx α l i) = length l - 1
| [], _, _ => rfl
| _::_, 0, _ => by simp [eraseIdx]
| x::xs, i+1, h => by
have : i < length xs := Nat.lt_of_succ_lt_succ h
simp [eraseIdx, ← Nat.add_one]
rw [length_eraseIdx this, Nat.sub_add_cancel (Nat.lt_of_le_of_lt (Nat.zero_le _) this)]
@[deprecated] alias length_removeNth := length_eraseIdx
@[simp] theorem length_tail (l : List α) : length (tail l) = length l - 1 := by cases l <;> rfl
@[simp] theorem eraseP_nil : [].eraseP p = [] := rfl
theorem eraseP_cons (a : α) (l : List α) :
(a :: l).eraseP p = bif p a then l else a :: l.eraseP p := rfl
@[simp] theorem eraseP_cons_of_pos {l : List α} (p) (h : p a) : (a :: l).eraseP p = l := by
simp [eraseP_cons, h]
@[simp] theorem eraseP_cons_of_neg {l : List α} (p) (h : ¬p a) :
(a :: l).eraseP p = a :: l.eraseP p := by simp [eraseP_cons, h]
theorem eraseP_of_forall_not {l : List α} (h : ∀ a, a ∈ l → ¬p a) : l.eraseP p = l := by
induction l with
| nil => rfl
| cons _ _ ih => simp [h _ (.head ..), ih (forall_mem_cons.1 h).2]
theorem exists_of_eraseP : ∀ {l : List α} {a} (al : a ∈ l) (pa : p a),
∃ a l₁ l₂, (∀ b ∈ l₁, ¬p b) ∧ p a ∧ l = l₁ ++ a :: l₂ ∧ l.eraseP p = l₁ ++ l₂
| b :: l, a, al, pa =>
if pb : p b then
⟨b, [], l, forall_mem_nil _, pb, by simp [pb]⟩
else
match al with
| .head .. => nomatch pb pa
| .tail _ al =>
let ⟨c, l₁, l₂, h₁, h₂, h₃, h₄⟩ := exists_of_eraseP al pa
⟨c, b::l₁, l₂, (forall_mem_cons ..).2 ⟨pb, h₁⟩,
h₂, by rw [h₃, cons_append], by simp [pb, h₄]⟩
theorem exists_or_eq_self_of_eraseP (p) (l : List α) :
l.eraseP p = l ∨
∃ a l₁ l₂, (∀ b ∈ l₁, ¬p b) ∧ p a ∧ l = l₁ ++ a :: l₂ ∧ l.eraseP p = l₁ ++ l₂ :=
if h : ∃ a ∈ l, p a then
let ⟨_, ha, pa⟩ := h
.inr (exists_of_eraseP ha pa)
else
.inl (eraseP_of_forall_not (h ⟨·, ·, ·⟩))
@[simp] theorem length_eraseP_of_mem (al : a ∈ l) (pa : p a) :
length (l.eraseP p) = Nat.pred (length l) := by
let ⟨_, l₁, l₂, _, _, e₁, e₂⟩ := exists_of_eraseP al pa
rw [e₂]; simp [length_append, e₁]; rfl
theorem eraseP_append_left {a : α} (pa : p a) :
∀ {l₁ : List α} l₂, a ∈ l₁ → (l₁++l₂).eraseP p = l₁.eraseP p ++ l₂
| x :: xs, l₂, h => by
by_cases h' : p x <;> simp [h']
rw [eraseP_append_left pa l₂ ((mem_cons.1 h).resolve_left (mt _ h'))]
intro | rfl => exact pa
theorem eraseP_append_right :
∀ {l₁ : List α} l₂, (∀ b ∈ l₁, ¬p b) → eraseP p (l₁++l₂) = l₁ ++ l₂.eraseP p
| [], l₂, _ => rfl
| x :: xs, l₂, h => by
simp [(forall_mem_cons.1 h).1, eraseP_append_right _ (forall_mem_cons.1 h).2]
theorem eraseP_sublist (l : List α) : l.eraseP p <+ l := by
match exists_or_eq_self_of_eraseP p l with
| .inl h => rw [h]; apply Sublist.refl
| .inr ⟨c, l₁, l₂, _, _, h₃, h₄⟩ => rw [h₄, h₃]; simp
theorem eraseP_subset (l : List α) : l.eraseP p ⊆ l := (eraseP_sublist l).subset
protected theorem Sublist.eraseP : l₁ <+ l₂ → l₁.eraseP p <+ l₂.eraseP p
| .slnil => Sublist.refl _
| .cons a s => by
by_cases h : p a <;> simp [h]
exacts [s.eraseP.trans (eraseP_sublist _), s.eraseP.cons _]
| .cons₂ a s => by
by_cases h : p a <;> simp [h]
exacts [s, s.eraseP]
theorem mem_of_mem_eraseP {l : List α} : a ∈ l.eraseP p → a ∈ l := (eraseP_subset _ ·)
@[simp] theorem mem_eraseP_of_neg {l : List α} (pa : ¬p a) : a ∈ l.eraseP p ↔ a ∈ l := by
refine ⟨mem_of_mem_eraseP, fun al => ?_⟩
match exists_or_eq_self_of_eraseP p l with
| .inl h => rw [h]; assumption
| .inr ⟨c, l₁, l₂, h₁, h₂, h₃, h₄⟩ =>
rw [h₄]; rw [h₃] at al
have : a ≠ c := fun h => (h ▸ pa).elim h₂
simp [this] at al; simp [al]
theorem eraseP_map (f : β → α) : ∀ (l : List β), (map f l).eraseP p = map f (l.eraseP (p ∘ f))
| [] => rfl
| b::l => by by_cases h : p (f b) <;> simp [h, eraseP_map f l, eraseP_cons_of_pos]
@[simp] theorem extractP_eq_find?_eraseP
(l : List α) : extractP p l = (find? p l, eraseP p l) := by
let rec go (acc) : ∀ xs, l = acc.data ++ xs →
extractP.go p l xs acc = (xs.find? p, acc.data ++ xs.eraseP p)
| [] => fun h => by simp [extractP.go, find?, eraseP, h]
| x::xs => by
simp [extractP.go, find?, eraseP]; cases p x <;> simp
· intro h; rw [go _ xs]; {simp}; simp [h]
exact go #[] _ rfl
@[simp] theorem filter_sublist {p : α → Bool} : ∀ (l : List α), filter p l <+ l
| [] => .slnil
| a :: l => by rw [filter]; split <;> simp [Sublist.cons, Sublist.cons₂, filter_sublist l]
theorem length_filter_le (p : α → Bool) (l : List α) :
(l.filter p).length ≤ l.length := (filter_sublist _).length_le
theorem length_filterMap_le (f : α → Option β) (l : List α) :
(filterMap f l).length ≤ l.length := by
rw [← length_map _ some, map_filterMap_some_eq_filter_map_is_some, ← length_map _ f]
apply length_filter_le
protected theorem Sublist.filterMap (f : α → Option β) (s : l₁ <+ l₂) :
filterMap f l₁ <+ filterMap f l₂ := by
induction s <;> simp <;> split <;> simp [*, cons, cons₂]
theorem Sublist.filter (p : α → Bool) {l₁ l₂} (s : l₁ <+ l₂) : filter p l₁ <+ filter p l₂ := by
rw [← filterMap_eq_filter]; apply s.filterMap
@[simp]
theorem filter_eq_self {l} : filter p l = l ↔ ∀ a ∈ l, p a := by
induction l with simp
| cons a l ih =>
cases h : p a <;> simp [*]
intro h; exact Nat.lt_irrefl _ (h ▸ length_filter_le p l)
@[simp]
theorem filter_length_eq_length {l} : (filter p l).length = l.length ↔ ∀ a ∈ l, p a :=
Iff.trans ⟨l.filter_sublist.eq_of_length, congrArg length⟩ filter_eq_self
@[simp] theorem findIdx_nil {α : Type _} (p : α → Bool) : [].findIdx p = 0 := rfl
theorem findIdx_cons (p : α → Bool) (b : α) (l : List α) :
(b :: l).findIdx p = bif p b then 0 else (l.findIdx p) + 1 := by
cases H : p b with
| true => simp [H, findIdx, findIdx.go]
| false => simp [H, findIdx, findIdx.go, findIdx_go_succ]
where
findIdx_go_succ (p : α → Bool) (l : List α) (n : Nat) :
List.findIdx.go p l (n + 1) = (findIdx.go p l n) + 1 := by
cases l with
| nil => unfold findIdx.go; exact Nat.succ_eq_add_one n
| cons head tail =>
unfold findIdx.go
cases p head <;> simp only [cond_false, cond_true]
exact findIdx_go_succ p tail (n + 1)
theorem findIdx_of_get?_eq_some {xs : List α} (w : xs.get? (xs.findIdx p) = some y) : p y := by
induction xs with
| nil => simp_all
| cons x xs ih => by_cases h : p x <;> simp_all [findIdx_cons]
theorem findIdx_get {xs : List α} {w : xs.findIdx p < xs.length} :
p (xs.get ⟨xs.findIdx p, w⟩) :=
xs.findIdx_of_get?_eq_some (get?_eq_get w)
theorem findIdx_lt_length_of_exists {xs : List α} (h : ∃ x ∈ xs, p x) :
xs.findIdx p < xs.length := by
induction xs with
| nil => simp_all
| cons x xs ih =>
by_cases p x
· simp_all only [forall_exists_index, and_imp, mem_cons, exists_eq_or_imp, true_or,
findIdx_cons, cond_true, length_cons]
apply Nat.succ_pos
· simp_all [findIdx_cons]
refine Nat.succ_lt_succ ?_
obtain ⟨x', m', h'⟩ := h
exact ih x' m' h'
theorem findIdx_get?_eq_get_of_exists {xs : List α} (h : ∃ x ∈ xs, p x) :
xs.get? (xs.findIdx p) = some (xs.get ⟨xs.findIdx p, xs.findIdx_lt_length_of_exists h⟩) :=
get?_eq_get (findIdx_lt_length_of_exists h)
@[simp] theorem findIdx?_nil : ([] : List α).findIdx? p i = none := rfl
@[simp] theorem findIdx?_cons :
(x :: xs).findIdx? p i = if p x then some i else findIdx? p xs (i + 1) := rfl
@[simp] theorem findIdx?_succ :
(xs : List α).findIdx? p (i+1) = (xs.findIdx? p i).map fun i => i + 1 := by
induction xs generalizing i with simp
| cons _ _ _ => split <;> simp_all
theorem findIdx?_eq_some_iff (xs : List α) (p : α → Bool) :
xs.findIdx? p = some i ↔ (xs.take (i + 1)).map p = replicate i false ++ [true] := by
induction xs generalizing i with
| nil => simp
| cons x xs ih =>
simp only [findIdx?_cons, Nat.zero_add, findIdx?_succ, take_succ_cons, map_cons]
split <;> cases i <;> simp_all
theorem findIdx?_of_eq_some {xs : List α} {p : α → Bool} (w : xs.findIdx? p = some i) :
match xs.get? i with | some a => p a | none => false := by
induction xs generalizing i with
| nil => simp_all
| cons x xs ih =>
simp_all only [findIdx?_cons, Nat.zero_add, findIdx?_succ]
split at w <;> cases i <;> simp_all
theorem findIdx?_of_eq_none {xs : List α} {p : α → Bool} (w : xs.findIdx? p = none) :
∀ i, match xs.get? i with | some a => ¬ p a | none => true := by
intro i
induction xs generalizing i with
| nil => simp_all
| cons x xs ih =>
simp_all only [Bool.not_eq_true, findIdx?_cons, Nat.zero_add, findIdx?_succ]
cases i with
| zero =>
split at w <;> simp_all
| succ i =>
simp only [get?_cons_succ]
apply ih
split at w <;> simp_all
@[simp] theorem findIdx?_append :
(xs ++ ys : List α).findIdx? p =
(xs.findIdx? p <|> (ys.findIdx? p).map fun i => i + xs.length) := by
induction xs with simp
| cons _ _ _ => split <;> simp_all [Option.map_orElse, Option.map_map]; rfl
@[simp] theorem findIdx?_replicate :
(replicate n a).findIdx? p = if 0 < n ∧ p a then some 0 else none := by
induction n with
| zero => simp
| succ n ih =>
simp only [replicate, findIdx?_cons, Nat.zero_add, findIdx?_succ, Nat.zero_lt_succ, true_and]
split <;> simp_all
theorem Pairwise.sublist : l₁ <+ l₂ → l₂.Pairwise R → l₁.Pairwise R
| .slnil, h => h
| .cons _ s, .cons _ h₂ => h₂.sublist s
| .cons₂ _ s, .cons h₁ h₂ => (h₂.sublist s).cons fun _ h => h₁ _ (s.subset h)
theorem pairwise_map {l : List α} :
(l.map f).Pairwise R ↔ l.Pairwise fun a b => R (f a) (f b) := by
induction l
· simp
· simp only [map, pairwise_cons, forall_mem_map_iff, *]
theorem pairwise_append {l₁ l₂ : List α} :
(l₁ ++ l₂).Pairwise R ↔ l₁.Pairwise R ∧ l₂.Pairwise R ∧ ∀ a ∈ l₁, ∀ b ∈ l₂, R a b := by
induction l₁ <;> simp [*, or_imp, forall_and, and_assoc, and_left_comm]
theorem pairwise_reverse {l : List α} :
l.reverse.Pairwise R ↔ l.Pairwise (fun a b => R b a) := by
induction l <;> simp [*, pairwise_append, and_comm]
theorem Pairwise.imp {α R S} (H : ∀ {a b}, R a b → S a b) :
∀ {l : List α}, l.Pairwise R → l.Pairwise S
| _, .nil => .nil
| _, .cons h₁ h₂ => .cons (H ∘ h₁ ·) (h₂.imp H)
theorem replaceF_nil : [].replaceF p = [] := rfl
theorem replaceF_cons (a : α) (l : List α) :
(a :: l).replaceF p = match p a with
| none => a :: replaceF p l
| some a' => a' :: l := rfl
theorem replaceF_cons_of_some {l : List α} (p) (h : p a = some a') :
(a :: l).replaceF p = a' :: l := by
simp [replaceF_cons, h]
theorem replaceF_cons_of_none {l : List α} (p) (h : p a = none) :
(a :: l).replaceF p = a :: l.replaceF p := by simp [replaceF_cons, h]
theorem replaceF_of_forall_none {l : List α} (h : ∀ a, a ∈ l → p a = none) : l.replaceF p = l := by
induction l with
| nil => rfl
| cons _ _ ih => simp [h _ (.head ..), ih (forall_mem_cons.1 h).2]
theorem exists_of_replaceF : ∀ {l : List α} {a a'} (al : a ∈ l) (pa : p a = some a'),
∃ a a' l₁ l₂,
(∀ b ∈ l₁, p b = none) ∧ p a = some a' ∧ l = l₁ ++ a :: l₂ ∧ l.replaceF p = l₁ ++ a' :: l₂
| b :: l, a, a', al, pa =>
match pb : p b with
| some b' => ⟨b, b', [], l, forall_mem_nil _, pb, by simp [pb]⟩
| none =>
match al with
| .head .. => nomatch pb.symm.trans pa
| .tail _ al =>
let ⟨c, c', l₁, l₂, h₁, h₂, h₃, h₄⟩ := exists_of_replaceF al pa
⟨c, c', b::l₁, l₂, (forall_mem_cons ..).2 ⟨pb, h₁⟩,
h₂, by rw [h₃, cons_append], by simp [pb, h₄]⟩
theorem exists_or_eq_self_of_replaceF (p) (l : List α) :
l.replaceF p = l ∨ ∃ a a' l₁ l₂,
(∀ b ∈ l₁, p b = none) ∧ p a = some a' ∧ l = l₁ ++ a :: l₂ ∧ l.replaceF p = l₁ ++ a' :: l₂ :=
if h : ∃ a ∈ l, (p a).isSome then
let ⟨_, ha, pa⟩ := h
.inr (exists_of_replaceF ha (Option.get_mem pa))
else
.inl <| replaceF_of_forall_none fun a ha =>
Option.not_isSome_iff_eq_none.1 fun h' => h ⟨a, ha, h'⟩
@[simp] theorem length_replaceF : length (replaceF f l) = length l := by
induction l <;> simp [replaceF]; split <;> simp [*]
theorem disjoint_symm (d : Disjoint l₁ l₂) : Disjoint l₂ l₁ := fun _ i₂ i₁ => d i₁ i₂
theorem disjoint_comm : Disjoint l₁ l₂ ↔ Disjoint l₂ l₁ := ⟨disjoint_symm, disjoint_symm⟩
theorem disjoint_left : Disjoint l₁ l₂ ↔ ∀ ⦃a⦄, a ∈ l₁ → a ∉ l₂ := by simp [Disjoint]
theorem disjoint_right : Disjoint l₁ l₂ ↔ ∀ ⦃a⦄, a ∈ l₂ → a ∉ l₁ := disjoint_comm
theorem disjoint_iff_ne : Disjoint l₁ l₂ ↔ ∀ a ∈ l₁, ∀ b ∈ l₂, a ≠ b :=
⟨fun h _ al1 _ bl2 ab => h al1 (ab ▸ bl2), fun h _ al1 al2 => h _ al1 _ al2 rfl⟩
theorem disjoint_of_subset_left (ss : l₁ ⊆ l) (d : Disjoint l l₂) : Disjoint l₁ l₂ :=
fun _ m => d (ss m)
theorem disjoint_of_subset_right (ss : l₂ ⊆ l) (d : Disjoint l₁ l) : Disjoint l₁ l₂ :=
fun _ m m₁ => d m (ss m₁)
theorem disjoint_of_disjoint_cons_left {l₁ l₂} : Disjoint (a :: l₁) l₂ → Disjoint l₁ l₂ :=
disjoint_of_subset_left (subset_cons _ _)
theorem disjoint_of_disjoint_cons_right {l₁ l₂} : Disjoint l₁ (a :: l₂) → Disjoint l₁ l₂ :=
disjoint_of_subset_right (subset_cons _ _)
@[simp] theorem disjoint_nil_left (l : List α) : Disjoint [] l := fun a => (not_mem_nil a).elim
@[simp] theorem disjoint_nil_right (l : List α) : Disjoint l [] := by
rw [disjoint_comm]; exact disjoint_nil_left _
@[simp 1100] theorem singleton_disjoint : Disjoint [a] l ↔ a ∉ l := by simp [Disjoint]
@[simp 1100] theorem disjoint_singleton : Disjoint l [a] ↔ a ∉ l := by
rw [disjoint_comm, singleton_disjoint]
@[simp] theorem disjoint_append_left : Disjoint (l₁ ++ l₂) l ↔ Disjoint l₁ l ∧ Disjoint l₂ l := by
simp [Disjoint, or_imp, forall_and]
@[simp] theorem disjoint_append_right : Disjoint l (l₁ ++ l₂) ↔ Disjoint l l₁ ∧ Disjoint l l₂ :=
disjoint_comm.trans <| by rw [disjoint_append_left]; simp [disjoint_comm]
@[simp] theorem disjoint_cons_left : Disjoint (a::l₁) l₂ ↔ (a ∉ l₂) ∧ Disjoint l₁ l₂ :=
(disjoint_append_left (l₁ := [a])).trans <| by simp [singleton_disjoint]
@[simp] theorem disjoint_cons_right : Disjoint l₁ (a :: l₂) ↔ (a ∉ l₁) ∧ Disjoint l₁ l₂ :=
disjoint_comm.trans <| by rw [disjoint_cons_left]; simp [disjoint_comm]
theorem disjoint_of_disjoint_append_left_left (d : Disjoint (l₁ ++ l₂) l) : Disjoint l₁ l :=
(disjoint_append_left.1 d).1
theorem disjoint_of_disjoint_append_left_right (d : Disjoint (l₁ ++ l₂) l) : Disjoint l₂ l :=
(disjoint_append_left.1 d).2
theorem disjoint_of_disjoint_append_right_left (d : Disjoint l (l₁ ++ l₂)) : Disjoint l l₁ :=
(disjoint_append_right.1 d).1
theorem disjoint_of_disjoint_append_right_right (d : Disjoint l (l₁ ++ l₂)) : Disjoint l l₂ :=
(disjoint_append_right.1 d).2
theorem foldl_hom (f : α₁ → α₂) (g₁ : α₁ → β → α₁) (g₂ : α₂ → β → α₂) (l : List β) (init : α₁)
(H : ∀ x y, g₂ (f x) y = f (g₁ x y)) : l.foldl g₂ (f init) = f (l.foldl g₁ init) := by
induction l generalizing init <;> simp [*, H]
theorem foldr_hom (f : β₁ → β₂) (g₁ : α → β₁ → β₁) (g₂ : α → β₂ → β₂) (l : List α) (init : β₁)
(H : ∀ x y, g₂ x (f y) = f (g₁ x y)) : l.foldr g₂ (f init) = f (l.foldr g₁ init) := by
induction l <;> simp [*, H]
theorem inter_def [BEq α] (l₁ l₂ : List α) : l₁ ∩ l₂ = filter (elem · l₂) l₁ := rfl
@[simp] theorem mem_inter_iff [BEq α] [LawfulBEq α] {x : α} {l₁ l₂ : List α} :
x ∈ l₁ ∩ l₂ ↔ x ∈ l₁ ∧ x ∈ l₂ := by
cases l₁ <;> simp [List.inter_def, mem_filter]
@[simp]
theorem pair_mem_product {xs : List α} {ys : List β} {x : α} {y : β} :
(x, y) ∈ product xs ys ↔ x ∈ xs ∧ y ∈ ys := by
simp only [product, and_imp, mem_map, Prod.mk.injEq,
exists_eq_right_right, mem_bind, iff_self]
@[simp]
theorem leftpad_length (n : Nat) (a : α) (l : List α) :
(leftpad n a l).length = max n l.length := by
simp only [leftpad, length_append, length_replicate, Nat.sub_add_eq_max]
theorem leftpad_prefix (n : Nat) (a : α) (l : List α) :
replicate (n - length l) a <+: leftpad n a l := by
simp only [IsPrefix, leftpad]
exact Exists.intro l rfl
theorem leftpad_suffix (n : Nat) (a : α) (l : List α) : l <:+ (leftpad n a l) := by
simp only [IsSuffix, leftpad]
exact Exists.intro (replicate (n - length l) a) rfl
-- we use ForIn.forIn as the simp normal form
@[simp] theorem forIn_eq_forIn [Monad m] : @List.forIn α β m _ = forIn := rfl
theorem forIn_eq_bindList [Monad m] [LawfulMonad m]
(f : α → β → m (ForInStep β)) (l : List α) (init : β) :
forIn l init f = ForInStep.run <$> (ForInStep.yield init).bindList f l := by
induction l generalizing init <;> simp [*, map_eq_pure_bind]
congr; ext (b | b) <;> simp
@[simp] theorem forM_append [Monad m] [LawfulMonad m] (l₁ l₂ : List α) (f : α → m PUnit) :
(l₁ ++ l₂).forM f = (do l₁.forM f; l₂.forM f) := by induction l₁ <;> simp [*]
@[simp] theorem prefix_append (l₁ l₂ : List α) : l₁ <+: l₁ ++ l₂ := ⟨l₂, rfl⟩
@[simp] theorem suffix_append (l₁ l₂ : List α) : l₂ <:+ l₁ ++ l₂ := ⟨l₁, rfl⟩
theorem infix_append (l₁ l₂ l₃ : List α) : l₂ <:+: l₁ ++ l₂ ++ l₃ := ⟨l₁, l₃, rfl⟩
@[simp] theorem infix_append' (l₁ l₂ l₃ : List α) : l₂ <:+: l₁ ++ (l₂ ++ l₃) := by
rw [← List.append_assoc]; apply infix_append
theorem IsPrefix.isInfix : l₁ <+: l₂ → l₁ <:+: l₂ := fun ⟨t, h⟩ => ⟨[], t, h⟩
theorem IsSuffix.isInfix : l₁ <:+ l₂ → l₁ <:+: l₂ := fun ⟨t, h⟩ => ⟨t, [], by rw [h, append_nil]⟩
theorem nil_prefix (l : List α) : [] <+: l := ⟨l, rfl⟩
theorem nil_suffix (l : List α) : [] <:+ l := ⟨l, append_nil _⟩
theorem nil_infix (l : List α) : [] <:+: l := (nil_prefix _).isInfix
theorem prefix_refl (l : List α) : l <+: l := ⟨[], append_nil _⟩
theorem suffix_refl (l : List α) : l <:+ l := ⟨[], rfl⟩
theorem infix_refl (l : List α) : l <:+: l := (prefix_refl l).isInfix
@[simp] theorem suffix_cons (a : α) : ∀ l, l <:+ a :: l := suffix_append [a]
theorem infix_cons : l₁ <:+: l₂ → l₁ <:+: a :: l₂ := fun ⟨L₁, L₂, h⟩ => ⟨a :: L₁, L₂, h ▸ rfl⟩
theorem infix_concat : l₁ <:+: l₂ → l₁ <:+: concat l₂ a := fun ⟨L₁, L₂, h⟩ =>
⟨L₁, concat L₂ a, by simp [← h, concat_eq_append, append_assoc]⟩
theorem IsPrefix.trans : ∀ {l₁ l₂ l₃ : List α}, l₁ <+: l₂ → l₂ <+: l₃ → l₁ <+: l₃
| _, _, _, ⟨r₁, rfl⟩, ⟨r₂, rfl⟩ => ⟨r₁ ++ r₂, (append_assoc _ _ _).symm⟩
theorem IsSuffix.trans : ∀ {l₁ l₂ l₃ : List α}, l₁ <:+ l₂ → l₂ <:+ l₃ → l₁ <:+ l₃
| _, _, _, ⟨l₁, rfl⟩, ⟨l₂, rfl⟩ => ⟨l₂ ++ l₁, append_assoc _ _ _⟩
theorem IsInfix.trans : ∀ {l₁ l₂ l₃ : List α}, l₁ <:+: l₂ → l₂ <:+: l₃ → l₁ <:+: l₃
| l, _, _, ⟨l₁, r₁, rfl⟩, ⟨l₂, r₂, rfl⟩ => ⟨l₂ ++ l₁, r₁ ++ r₂, by simp only [append_assoc]⟩
protected theorem IsInfix.sublist : l₁ <:+: l₂ → l₁ <+ l₂
| ⟨_, _, h⟩ => h ▸ (sublist_append_right ..).trans (sublist_append_left ..)
protected theorem IsInfix.subset (hl : l₁ <:+: l₂) : l₁ ⊆ l₂ :=
hl.sublist.subset
protected theorem IsPrefix.sublist (h : l₁ <+: l₂) : l₁ <+ l₂ :=
h.isInfix.sublist
protected theorem IsPrefix.subset (hl : l₁ <+: l₂) : l₁ ⊆ l₂ :=
hl.sublist.subset
protected theorem IsSuffix.sublist (h : l₁ <:+ l₂) : l₁ <+ l₂ :=
h.isInfix.sublist
protected theorem IsSuffix.subset (hl : l₁ <:+ l₂) : l₁ ⊆ l₂ :=
hl.sublist.subset
@[simp] theorem reverse_suffix : reverse l₁ <:+ reverse l₂ ↔ l₁ <+: l₂ :=
⟨fun ⟨r, e⟩ => ⟨reverse r, by rw [← reverse_reverse l₁, ← reverse_append, e, reverse_reverse]⟩,
fun ⟨r, e⟩ => ⟨reverse r, by rw [← reverse_append, e]⟩⟩
@[simp] theorem reverse_prefix : reverse l₁ <+: reverse l₂ ↔ l₁ <:+ l₂ := by
rw [← reverse_suffix]; simp only [reverse_reverse]
@[simp] theorem reverse_infix : reverse l₁ <:+: reverse l₂ ↔ l₁ <:+: l₂ := by
refine ⟨fun ⟨s, t, e⟩ => ⟨reverse t, reverse s, ?_⟩, fun ⟨s, t, e⟩ => ⟨reverse t, reverse s, ?_⟩⟩
· rw [← reverse_reverse l₁, append_assoc, ← reverse_append, ← reverse_append, e,
reverse_reverse]
· rw [append_assoc, ← reverse_append, ← reverse_append, e]
theorem IsInfix.length_le (h : l₁ <:+: l₂) : l₁.length ≤ l₂.length :=
h.sublist.length_le
theorem IsPrefix.length_le (h : l₁ <+: l₂) : l₁.length ≤ l₂.length :=
h.sublist.length_le
theorem IsSuffix.length_le (h : l₁ <:+ l₂) : l₁.length ≤ l₂.length :=
h.sublist.length_le
@[simp] theorem infix_nil : l <:+: [] ↔ l = [] := ⟨(sublist_nil.1 ·.sublist), (· ▸ infix_refl _)⟩
@[simp] theorem prefix_nil : l <+: [] ↔ l = [] := ⟨(sublist_nil.1 ·.sublist), (· ▸ prefix_refl _)⟩
@[simp] theorem suffix_nil : l <:+ [] ↔ l = [] := ⟨(sublist_nil.1 ·.sublist), (· ▸ suffix_refl _)⟩
theorem infix_iff_prefix_suffix (l₁ l₂ : List α) : l₁ <:+: l₂ ↔ ∃ t, l₁ <+: t ∧ t <:+ l₂ :=
⟨fun ⟨_, t, e⟩ => ⟨l₁ ++ t, ⟨_, rfl⟩, e ▸ append_assoc .. ▸ ⟨_, rfl⟩⟩,
fun ⟨_, ⟨t, rfl⟩, s, e⟩ => ⟨s, t, append_assoc .. ▸ e⟩⟩
theorem IsInfix.eq_of_length (h : l₁ <:+: l₂) : l₁.length = l₂.length → l₁ = l₂ :=
h.sublist.eq_of_length
theorem IsPrefix.eq_of_length (h : l₁ <+: l₂) : l₁.length = l₂.length → l₁ = l₂ :=
h.sublist.eq_of_length
theorem IsSuffix.eq_of_length (h : l₁ <:+ l₂) : l₁.length = l₂.length → l₁ = l₂ :=
h.sublist.eq_of_length
theorem prefix_of_prefix_length_le :
∀ {l₁ l₂ l₃ : List α}, l₁ <+: l₃ → l₂ <+: l₃ → length l₁ ≤ length l₂ → l₁ <+: l₂
| [], l₂, _, _, _, _ => nil_prefix _
| a :: l₁, b :: l₂, _, ⟨r₁, rfl⟩, ⟨r₂, e⟩, ll => by
injection e with _ e'; subst b
rcases prefix_of_prefix_length_le ⟨_, rfl⟩ ⟨_, e'⟩ (le_of_succ_le_succ ll) with ⟨r₃, rfl⟩
exact ⟨r₃, rfl⟩
theorem prefix_or_prefix_of_prefix (h₁ : l₁ <+: l₃) (h₂ : l₂ <+: l₃) : l₁ <+: l₂ ∨ l₂ <+: l₁ :=
(Nat.le_total (length l₁) (length l₂)).imp (prefix_of_prefix_length_le h₁ h₂)
(prefix_of_prefix_length_le h₂ h₁)
theorem suffix_of_suffix_length_le
(h₁ : l₁ <:+ l₃) (h₂ : l₂ <:+ l₃) (ll : length l₁ ≤ length l₂) : l₁ <:+ l₂ :=
reverse_prefix.1 <|
prefix_of_prefix_length_le (reverse_prefix.2 h₁) (reverse_prefix.2 h₂) (by simp [ll])
theorem suffix_or_suffix_of_suffix (h₁ : l₁ <:+ l₃) (h₂ : l₂ <:+ l₃) : l₁ <:+ l₂ ∨ l₂ <:+ l₁ :=
(prefix_or_prefix_of_prefix (reverse_prefix.2 h₁) (reverse_prefix.2 h₂)).imp reverse_prefix.1
reverse_prefix.1
theorem suffix_cons_iff : l₁ <:+ a :: l₂ ↔ l₁ = a :: l₂ ∨ l₁ <:+ l₂ := by
constructor
· rintro ⟨⟨hd, tl⟩, hl₃⟩
· exact Or.inl hl₃
· simp only [cons_append] at hl₃
injection hl₃ with _ hl₄
exact Or.inr ⟨_, hl₄⟩
· rintro (rfl | hl₁)
· exact (a :: l₂).suffix_refl
· exact hl₁.trans (l₂.suffix_cons _)
theorem infix_cons_iff : l₁ <:+: a :: l₂ ↔ l₁ <+: a :: l₂ ∨ l₁ <:+: l₂ := by
constructor
· rintro ⟨⟨hd, tl⟩, t, hl₃⟩
· exact Or.inl ⟨t, hl₃⟩
· simp only [cons_append] at hl₃
injection hl₃ with _ hl₄
exact Or.inr ⟨_, t, hl₄⟩
· rintro (h | hl₁)
· exact h.isInfix
· exact infix_cons hl₁
theorem infix_of_mem_join : ∀ {L : List (List α)}, l ∈ L → l <:+: join L
| l' :: _, h =>
match h with
| List.Mem.head .. => infix_append [] _ _
| List.Mem.tail _ hlMemL =>
IsInfix.trans (infix_of_mem_join hlMemL) <| (suffix_append _ _).isInfix
theorem prefix_append_right_inj (l) : l ++ l₁ <+: l ++ l₂ ↔ l₁ <+: l₂ :=
exists_congr fun r => by rw [append_assoc, append_right_inj]
@[simp]
theorem prefix_cons_inj (a) : a :: l₁ <+: a :: l₂ ↔ l₁ <+: l₂ :=
prefix_append_right_inj [a]
theorem take_prefix (n) (l : List α) : take n l <+: l :=
⟨_, take_append_drop _ _⟩
theorem drop_suffix (n) (l : List α) : drop n l <:+ l :=
⟨_, take_append_drop _ _⟩
theorem take_sublist (n) (l : List α) : take n l <+ l :=
(take_prefix n l).sublist
theorem drop_sublist (n) (l : List α) : drop n l <+ l :=
(drop_suffix n l).sublist
theorem take_subset (n) (l : List α) : take n l ⊆ l :=
(take_sublist n l).subset
theorem drop_subset (n) (l : List α) : drop n l ⊆ l :=
(drop_sublist n l).subset
theorem mem_of_mem_take {l : List α} (h : a ∈ l.take n) : a ∈ l :=
take_subset n l h
theorem IsPrefix.filter (p : α → Bool) ⦃l₁ l₂ : List α⦄ (h : l₁ <+: l₂) :
l₁.filter p <+: l₂.filter p := by
obtain ⟨xs, rfl⟩ := h
rw [filter_append]; apply prefix_append
theorem IsSuffix.filter (p : α → Bool) ⦃l₁ l₂ : List α⦄ (h : l₁ <:+ l₂) :
l₁.filter p <:+ l₂.filter p := by
obtain ⟨xs, rfl⟩ := h
rw [filter_append]; apply suffix_append
theorem IsInfix.filter (p : α → Bool) ⦃l₁ l₂ : List α⦄ (h : l₁ <:+: l₂) :
l₁.filter p <:+: l₂.filter p := by
obtain ⟨xs, ys, rfl⟩ := h
rw [filter_append, filter_append]; apply infix_append _
theorem mem_of_mem_drop {n} {l : List α} (h : a ∈ l.drop n) : a ∈ l := drop_subset _ _ h
theorem disjoint_take_drop : ∀ {l : List α}, l.Nodup → m ≤ n → Disjoint (l.take m) (l.drop n)
| [], _, _ => by simp
| x :: xs, hl, h => by
cases m <;> cases n <;> simp only [disjoint_cons_left, drop, not_mem_nil, disjoint_nil_left,
take, not_false_eq_true, and_self]
· case succ.zero => cases h
· cases hl with | cons h₀ h₁ =>
refine ⟨fun h => h₀ _ (mem_of_mem_drop h) rfl, ?_⟩
exact disjoint_take_drop h₁ (Nat.le_of_succ_le_succ h)
attribute [simp] Chain.nil
@[simp]
theorem chain_cons {a b : α} {l : List α} : Chain R a (b :: l) ↔ R a b ∧ Chain R b l :=
⟨fun p => by cases p with | cons n p => exact ⟨n, p⟩,
fun ⟨n, p⟩ => p.cons n⟩
theorem rel_of_chain_cons {a b : α} {l : List α} (p : Chain R a (b :: l)) : R a b :=
(chain_cons.1 p).1
theorem chain_of_chain_cons {a b : α} {l : List α} (p : Chain R a (b :: l)) : Chain R b l :=
(chain_cons.1 p).2
theorem Chain.imp' {R S : α → α → Prop} (HRS : ∀ ⦃a b⦄, R a b → S a b) {a b : α}
(Hab : ∀ ⦃c⦄, R a c → S b c) {l : List α} (p : Chain R a l) : Chain S b l := by
induction p generalizing b with
| nil => constructor
| cons r _ ih =>
constructor
· exact Hab r
· exact ih (@HRS _)
theorem Chain.imp {R S : α → α → Prop} (H : ∀ a b, R a b → S a b) {a : α} {l : List α}
(p : Chain R a l) : Chain S a l :=
p.imp' H (H a)
protected theorem Pairwise.chain (p : Pairwise R (a :: l)) : Chain R a l := by
let ⟨r, p'⟩ := pairwise_cons.1 p; clear p
induction p' generalizing a with
| nil => exact Chain.nil
| @cons b l r' _ IH =>
simp only [chain_cons, forall_mem_cons] at r
exact chain_cons.2 ⟨r.1, IH r'⟩
@[simp] theorem length_range' (s step) : ∀ n : Nat, length (range' s n step) = n
| 0 => rfl
| _ + 1 => congrArg succ (length_range' _ _ _)
@[simp] theorem range'_eq_nil : range' s n step = [] ↔ n = 0 := by
rw [← length_eq_zero, length_range']
theorem mem_range' : ∀{n}, m ∈ range' s n step ↔ ∃ i < n, m = s + step * i
| 0 => by simp [range', Nat.not_lt_zero]
| n + 1 => by
have h (i) : i ≤ n ↔ i = 0 ∨ ∃ j, i = succ j ∧ j < n := by cases i <;> simp [Nat.succ_le]
simp [range', mem_range', Nat.lt_succ, h]; simp only [← exists_and_right, and_assoc]
rw [exists_comm]; simp [Nat.mul_succ, Nat.add_assoc, Nat.add_comm]
@[simp] theorem mem_range'_1 : m ∈ range' s n ↔ s ≤ m ∧ m < s + n := by
simp [mem_range']; exact ⟨
fun ⟨i, h, e⟩ => e ▸ ⟨Nat.le_add_right .., Nat.add_lt_add_left h _⟩,
fun ⟨h₁, h₂⟩ => ⟨m - s, Nat.sub_lt_left_of_lt_add h₁ h₂, (Nat.add_sub_cancel' h₁).symm⟩⟩
@[simp]
theorem map_add_range' (a) : ∀ s n step, map (a + ·) (range' s n step) = range' (a + s) n step
| _, 0, _ => rfl
| s, n + 1, step => by simp [range', map_add_range' _ (s + step) n step, Nat.add_assoc]
theorem map_sub_range' (a s n : Nat) (h : a ≤ s) :
map (· - a) (range' s n step) = range' (s - a) n step := by
conv => lhs; rw [← Nat.add_sub_cancel' h]
rw [← map_add_range', map_map, (?_ : _∘_ = _), map_id]
funext x; apply Nat.add_sub_cancel_left
theorem chain_succ_range' : ∀ s n step : Nat,
Chain (fun a b => b = a + step) s (range' (s + step) n step)
| _, 0, _ => Chain.nil
| s, n + 1, step => (chain_succ_range' (s + step) n step).cons rfl
theorem chain_lt_range' (s n : Nat) {step} (h : 0 < step) :
Chain (· < ·) s (range' (s + step) n step) :=
(chain_succ_range' s n step).imp fun _ _ e => e.symm ▸ Nat.lt_add_of_pos_right h
theorem range'_append : ∀ s m n step : Nat,
range' s m step ++ range' (s + step * m) n step = range' s (n + m) step
| s, 0, n, step => rfl
| s, m + 1, n, step => by
simpa [range', Nat.mul_succ, Nat.add_assoc, Nat.add_comm]
using range'_append (s + step) m n step
@[simp] theorem range'_append_1 (s m n : Nat) :
range' s m ++ range' (s + m) n = range' s (n + m) := by simpa using range'_append s m n 1
theorem range'_sublist_right {s m n : Nat} : range' s m step <+ range' s n step ↔ m ≤ n :=
⟨fun h => by simpa only [length_range'] using h.length_le,
fun h => by rw [← Nat.sub_add_cancel h, ← range'_append]; apply sublist_append_left⟩
theorem range'_subset_right {s m n : Nat} (step0 : 0 < step) :
range' s m step ⊆ range' s n step ↔ m ≤ n := by
refine ⟨fun h => Nat.le_of_not_lt fun hn => ?_, fun h => (range'_sublist_right.2 h).subset⟩
have ⟨i, h', e⟩ := mem_range'.1 <| h <| mem_range'.2 ⟨_, hn, rfl⟩
exact Nat.ne_of_gt h' (Nat.eq_of_mul_eq_mul_left step0 (Nat.add_left_cancel e))
theorem range'_subset_right_1 {s m n : Nat} : range' s m ⊆ range' s n ↔ m ≤ n :=
range'_subset_right (by decide)
theorem get?_range' (s step) : ∀ {m n : Nat}, m < n → get? (range' s n step) m = some (s + step * m)
| 0, n + 1, _ => rfl
| m + 1, n + 1, h =>
(get?_range' (s + step) step (Nat.lt_of_add_lt_add_right h)).trans <| by
simp [Nat.mul_succ, Nat.add_assoc, Nat.add_comm]
@[simp] theorem get_range' {n m step} (i) (H : i < (range' n m step).length) :
get (range' n m step) ⟨i, H⟩ = n + step * i :=
(get?_eq_some.1 <| get?_range' n step (by simpa using H)).2
theorem range'_concat (s n : Nat) : range' s (n + 1) step = range' s n step ++ [s + step * n] := by
rw [Nat.add_comm n 1]; exact (range'_append s n 1 step).symm
theorem range'_1_concat (s n : Nat) : range' s (n + 1) = range' s n ++ [s + n] := by
simp [range'_concat]
theorem range_loop_range' : ∀ s n : Nat, range.loop s (range' s n) = range' 0 (n + s)
| 0, n => rfl
| s + 1, n => by rw [← Nat.add_assoc, Nat.add_right_comm n s 1]; exact range_loop_range' s (n + 1)
theorem range_eq_range' (n : Nat) : range n = range' 0 n :=
(range_loop_range' n 0).trans <| by rw [Nat.zero_add]
theorem range_succ_eq_map (n : Nat) : range (n + 1) = 0 :: map succ (range n) := by
rw [range_eq_range', range_eq_range', range', Nat.add_comm, ← map_add_range']
congr; exact funext one_add
theorem range'_eq_map_range (s n : Nat) : range' s n = map (s + ·) (range n) := by
rw [range_eq_range', map_add_range']; rfl
@[simp] theorem length_range (n : Nat) : length (range n) = n := by
simp only [range_eq_range', length_range']
@[simp] theorem range_eq_nil {n : Nat} : range n = [] ↔ n = 0 := by
rw [← length_eq_zero, length_range]
@[simp]
theorem range_sublist {m n : Nat} : range m <+ range n ↔ m ≤ n := by
simp only [range_eq_range', range'_sublist_right]
@[simp]
theorem range_subset {m n : Nat} : range m ⊆ range n ↔ m ≤ n := by
simp only [range_eq_range', range'_subset_right, lt_succ_self]
@[simp]
theorem mem_range {m n : Nat} : m ∈ range n ↔ m < n := by
simp only [range_eq_range', mem_range'_1, Nat.zero_le, true_and, Nat.zero_add]
theorem not_mem_range_self {n : Nat} : n ∉ range n := by simp
theorem self_mem_range_succ (n : Nat) : n ∈ range (n + 1) := by simp
| .lake/packages/batteries/Batteries/Data/List/Lemmas.lean | 1,386 | 1,387 | theorem get?_range {m n : Nat} (h : m < n) : get? (range n) m = some m := by |
simp [range_eq_range', get?_range' _ _ h]
|
import Mathlib.Algebra.BigOperators.Group.Finset
import Mathlib.Algebra.Group.Commute.Hom
import Mathlib.Data.Fintype.Card
#align_import data.finset.noncomm_prod from "leanprover-community/mathlib"@"509de852e1de55e1efa8eacfa11df0823f26f226"
variable {F ι α β γ : Type*} (f : α → β → β) (op : α → α → α)
namespace Multiset
def noncommFoldr (s : Multiset α)
(comm : { x | x ∈ s }.Pairwise fun x y => ∀ b, f x (f y b) = f y (f x b)) (b : β) : β :=
s.attach.foldr (f ∘ Subtype.val)
(fun ⟨_, hx⟩ ⟨_, hy⟩ =>
haveI : IsRefl α fun x y => ∀ b, f x (f y b) = f y (f x b) := ⟨fun _ _ => rfl⟩
comm.of_refl hx hy)
b
#align multiset.noncomm_foldr Multiset.noncommFoldr
@[simp]
theorem noncommFoldr_coe (l : List α) (comm) (b : β) :
noncommFoldr f (l : Multiset α) comm b = l.foldr f b := by
simp only [noncommFoldr, coe_foldr, coe_attach, List.attach, List.attachWith, Function.comp]
rw [← List.foldr_map]
simp [List.map_pmap]
#align multiset.noncomm_foldr_coe Multiset.noncommFoldr_coe
@[simp]
theorem noncommFoldr_empty (h) (b : β) : noncommFoldr f (0 : Multiset α) h b = b :=
rfl
#align multiset.noncomm_foldr_empty Multiset.noncommFoldr_empty
theorem noncommFoldr_cons (s : Multiset α) (a : α) (h h') (b : β) :
noncommFoldr f (a ::ₘ s) h b = f a (noncommFoldr f s h' b) := by
induction s using Quotient.inductionOn
simp
#align multiset.noncomm_foldr_cons Multiset.noncommFoldr_cons
theorem noncommFoldr_eq_foldr (s : Multiset α) (h : LeftCommutative f) (b : β) :
noncommFoldr f s (fun x _ y _ _ => h x y) b = foldr f h b s := by
induction s using Quotient.inductionOn
simp
#align multiset.noncomm_foldr_eq_foldr Multiset.noncommFoldr_eq_foldr
namespace Finset
variable [Monoid β] [Monoid γ]
@[to_additive]
theorem noncommProd_lemma (s : Finset α) (f : α → β)
(comm : (s : Set α).Pairwise fun a b => Commute (f a) (f b)) :
Set.Pairwise { x | x ∈ Multiset.map f s.val } Commute := by
simp_rw [Multiset.mem_map]
rintro _ ⟨a, ha, rfl⟩ _ ⟨b, hb, rfl⟩ _
exact comm.of_refl ha hb
@[to_additive
"Sum of a `s : Finset α` mapped with `f : α → β` with `[AddMonoid β]`,
given a proof that `+` commutes on all elements `f x` for `x ∈ s`."]
def noncommProd (s : Finset α) (f : α → β)
(comm : (s : Set α).Pairwise fun a b => Commute (f a) (f b)) : β :=
(s.1.map f).noncommProd <| noncommProd_lemma s f comm
#align finset.noncomm_prod Finset.noncommProd
#align finset.noncomm_sum Finset.noncommSum
@[to_additive]
lemma noncommProd_induction (s : Finset α) (f : α → β) (comm)
(p : β → Prop) (hom : ∀ a b, p a → p b → p (a * b)) (unit : p 1) (base : ∀ x ∈ s, p (f x)) :
p (s.noncommProd f comm) := by
refine Multiset.noncommProd_induction _ _ _ hom unit fun b hb ↦ ?_
obtain (⟨a, ha : a ∈ s, rfl : f a = b⟩) := by simpa using hb
exact base a ha
@[to_additive (attr := congr)]
theorem noncommProd_congr {s₁ s₂ : Finset α} {f g : α → β} (h₁ : s₁ = s₂)
(h₂ : ∀ x ∈ s₂, f x = g x) (comm) :
noncommProd s₁ f comm =
noncommProd s₂ g fun x hx y hy h => by
dsimp only
rw [← h₂ _ hx, ← h₂ _ hy]
subst h₁
exact comm hx hy h := by
simp_rw [noncommProd, Multiset.map_congr (congr_arg _ h₁) h₂]
#align finset.noncomm_prod_congr Finset.noncommProd_congr
#align finset.noncomm_sum_congr Finset.noncommSum_congr
@[to_additive (attr := simp)]
theorem noncommProd_toFinset [DecidableEq α] (l : List α) (f : α → β) (comm) (hl : l.Nodup) :
noncommProd l.toFinset f comm = (l.map f).prod := by
rw [← List.dedup_eq_self] at hl
simp [noncommProd, hl]
#align finset.noncomm_prod_to_finset Finset.noncommProd_toFinset
#align finset.noncomm_sum_to_finset Finset.noncommSum_toFinset
@[to_additive (attr := simp)]
theorem noncommProd_empty (f : α → β) (h) : noncommProd (∅ : Finset α) f h = 1 :=
rfl
#align finset.noncomm_prod_empty Finset.noncommProd_empty
#align finset.noncomm_sum_empty Finset.noncommSum_empty
@[to_additive (attr := simp)]
theorem noncommProd_cons (s : Finset α) (a : α) (f : α → β)
(ha : a ∉ s) (comm) :
noncommProd (cons a s ha) f comm =
f a * noncommProd s f (comm.mono fun _ => Finset.mem_cons.2 ∘ .inr) := by
simp_rw [noncommProd, Finset.cons_val, Multiset.map_cons, Multiset.noncommProd_cons]
@[to_additive]
theorem noncommProd_cons' (s : Finset α) (a : α) (f : α → β)
(ha : a ∉ s) (comm) :
noncommProd (cons a s ha) f comm =
noncommProd s f (comm.mono fun _ => Finset.mem_cons.2 ∘ .inr) * f a := by
simp_rw [noncommProd, Finset.cons_val, Multiset.map_cons, Multiset.noncommProd_cons']
@[to_additive (attr := simp)]
theorem noncommProd_insert_of_not_mem [DecidableEq α] (s : Finset α) (a : α) (f : α → β) (comm)
(ha : a ∉ s) :
noncommProd (insert a s) f comm =
f a * noncommProd s f (comm.mono fun _ => mem_insert_of_mem) := by
simp only [← cons_eq_insert _ _ ha, noncommProd_cons]
#align finset.noncomm_prod_insert_of_not_mem Finset.noncommProd_insert_of_not_mem
#align finset.noncomm_sum_insert_of_not_mem Finset.noncommSum_insert_of_not_mem
@[to_additive]
theorem noncommProd_insert_of_not_mem' [DecidableEq α] (s : Finset α) (a : α) (f : α → β) (comm)
(ha : a ∉ s) :
noncommProd (insert a s) f comm =
noncommProd s f (comm.mono fun _ => mem_insert_of_mem) * f a := by
simp only [← cons_eq_insert _ _ ha, noncommProd_cons']
#align finset.noncomm_prod_insert_of_not_mem' Finset.noncommProd_insert_of_not_mem'
#align finset.noncomm_sum_insert_of_not_mem' Finset.noncommSum_insert_of_not_mem'
@[to_additive (attr := simp)]
theorem noncommProd_singleton (a : α) (f : α → β) :
noncommProd ({a} : Finset α) f
(by
norm_cast
exact Set.pairwise_singleton _ _) =
f a := mul_one _
#align finset.noncomm_prod_singleton Finset.noncommProd_singleton
#align finset.noncomm_sum_singleton Finset.noncommSum_singleton
variable [FunLike F β γ]
@[to_additive]
theorem noncommProd_map [MonoidHomClass F β γ] (s : Finset α) (f : α → β) (comm) (g : F) :
g (s.noncommProd f comm) =
s.noncommProd (fun i => g (f i)) fun x hx y hy _ => (comm.of_refl hx hy).map g := by
simp [noncommProd, Multiset.noncommProd_map]
#align finset.noncomm_prod_map Finset.noncommProd_map
#align finset.noncomm_sum_map Finset.noncommSum_map
@[to_additive noncommSum_eq_card_nsmul]
theorem noncommProd_eq_pow_card (s : Finset α) (f : α → β) (comm) (m : β) (h : ∀ x ∈ s, f x = m) :
s.noncommProd f comm = m ^ s.card := by
rw [noncommProd, Multiset.noncommProd_eq_pow_card _ _ m]
· simp only [Finset.card_def, Multiset.card_map]
· simpa using h
#align finset.noncomm_prod_eq_pow_card Finset.noncommProd_eq_pow_card
#align finset.noncomm_sum_eq_card_nsmul Finset.noncommSum_eq_card_nsmul
@[to_additive]
theorem noncommProd_commute (s : Finset α) (f : α → β) (comm) (y : β)
(h : ∀ x ∈ s, Commute y (f x)) : Commute y (s.noncommProd f comm) := by
apply Multiset.noncommProd_commute
intro y
rw [Multiset.mem_map]
rintro ⟨x, ⟨hx, rfl⟩⟩
exact h x hx
#align finset.noncomm_prod_commute Finset.noncommProd_commute
#align finset.noncomm_sum_add_commute Finset.noncommSum_addCommute
| Mathlib/Data/Finset/NoncommProd.lean | 386 | 391 | theorem mul_noncommProd_erase [DecidableEq α] (s : Finset α) {a : α} (h : a ∈ s) (f : α → β) (comm)
(comm' := fun x hx y hy hxy ↦ comm (s.mem_of_mem_erase hx) (s.mem_of_mem_erase hy) hxy) :
f a * (s.erase a).noncommProd f comm' = s.noncommProd f comm := by |
classical
simpa only [← Multiset.map_erase_of_mem _ _ h] using
Multiset.mul_noncommProd_erase (s.1.map f) (Multiset.mem_map_of_mem f h) _
|
import Mathlib.Order.Heyting.Basic
#align_import order.boolean_algebra from "leanprover-community/mathlib"@"9ac7c0c8c4d7a535ec3e5b34b8859aab9233b2f4"
open Function OrderDual
universe u v
variable {α : Type u} {β : Type*} {w x y z : α}
class GeneralizedBooleanAlgebra (α : Type u) extends DistribLattice α, SDiff α, Bot α where
sup_inf_sdiff : ∀ a b : α, a ⊓ b ⊔ a \ b = a
inf_inf_sdiff : ∀ a b : α, a ⊓ b ⊓ a \ b = ⊥
#align generalized_boolean_algebra GeneralizedBooleanAlgebra
-- We might want an `IsCompl_of` predicate (for relative complements) generalizing `IsCompl`,
-- however we'd need another type class for lattices with bot, and all the API for that.
section GeneralizedBooleanAlgebra
variable [GeneralizedBooleanAlgebra α]
@[simp]
theorem sup_inf_sdiff (x y : α) : x ⊓ y ⊔ x \ y = x :=
GeneralizedBooleanAlgebra.sup_inf_sdiff _ _
#align sup_inf_sdiff sup_inf_sdiff
@[simp]
theorem inf_inf_sdiff (x y : α) : x ⊓ y ⊓ x \ y = ⊥ :=
GeneralizedBooleanAlgebra.inf_inf_sdiff _ _
#align inf_inf_sdiff inf_inf_sdiff
@[simp]
theorem sup_sdiff_inf (x y : α) : x \ y ⊔ x ⊓ y = x := by rw [sup_comm, sup_inf_sdiff]
#align sup_sdiff_inf sup_sdiff_inf
@[simp]
theorem inf_sdiff_inf (x y : α) : x \ y ⊓ (x ⊓ y) = ⊥ := by rw [inf_comm, inf_inf_sdiff]
#align inf_sdiff_inf inf_sdiff_inf
-- see Note [lower instance priority]
instance (priority := 100) GeneralizedBooleanAlgebra.toOrderBot : OrderBot α where
__ := GeneralizedBooleanAlgebra.toBot
bot_le a := by
rw [← inf_inf_sdiff a a, inf_assoc]
exact inf_le_left
#align generalized_boolean_algebra.to_order_bot GeneralizedBooleanAlgebra.toOrderBot
theorem disjoint_inf_sdiff : Disjoint (x ⊓ y) (x \ y) :=
disjoint_iff_inf_le.mpr (inf_inf_sdiff x y).le
#align disjoint_inf_sdiff disjoint_inf_sdiff
-- TODO: in distributive lattices, relative complements are unique when they exist
theorem sdiff_unique (s : x ⊓ y ⊔ z = x) (i : x ⊓ y ⊓ z = ⊥) : x \ y = z := by
conv_rhs at s => rw [← sup_inf_sdiff x y, sup_comm]
rw [sup_comm] at s
conv_rhs at i => rw [← inf_inf_sdiff x y, inf_comm]
rw [inf_comm] at i
exact (eq_of_inf_eq_sup_eq i s).symm
#align sdiff_unique sdiff_unique
-- Use `sdiff_le`
private theorem sdiff_le' : x \ y ≤ x :=
calc
x \ y ≤ x ⊓ y ⊔ x \ y := le_sup_right
_ = x := sup_inf_sdiff x y
-- Use `sdiff_sup_self`
private theorem sdiff_sup_self' : y \ x ⊔ x = y ⊔ x :=
calc
y \ x ⊔ x = y \ x ⊔ (x ⊔ x ⊓ y) := by rw [sup_inf_self]
_ = y ⊓ x ⊔ y \ x ⊔ x := by ac_rfl
_ = y ⊔ x := by rw [sup_inf_sdiff]
@[simp]
theorem sdiff_inf_sdiff : x \ y ⊓ y \ x = ⊥ :=
Eq.symm <|
calc
⊥ = x ⊓ y ⊓ x \ y := by rw [inf_inf_sdiff]
_ = x ⊓ (y ⊓ x ⊔ y \ x) ⊓ x \ y := by rw [sup_inf_sdiff]
_ = (x ⊓ (y ⊓ x) ⊔ x ⊓ y \ x) ⊓ x \ y := by rw [inf_sup_left]
_ = (y ⊓ (x ⊓ x) ⊔ x ⊓ y \ x) ⊓ x \ y := by ac_rfl
_ = (y ⊓ x ⊔ x ⊓ y \ x) ⊓ x \ y := by rw [inf_idem]
_ = x ⊓ y ⊓ x \ y ⊔ x ⊓ y \ x ⊓ x \ y := by rw [inf_sup_right, inf_comm x y]
_ = x ⊓ y \ x ⊓ x \ y := by rw [inf_inf_sdiff, bot_sup_eq]
_ = x ⊓ x \ y ⊓ y \ x := by ac_rfl
_ = x \ y ⊓ y \ x := by rw [inf_of_le_right sdiff_le']
#align sdiff_inf_sdiff sdiff_inf_sdiff
theorem disjoint_sdiff_sdiff : Disjoint (x \ y) (y \ x) :=
disjoint_iff_inf_le.mpr sdiff_inf_sdiff.le
#align disjoint_sdiff_sdiff disjoint_sdiff_sdiff
@[simp]
theorem inf_sdiff_self_right : x ⊓ y \ x = ⊥ :=
calc
x ⊓ y \ x = (x ⊓ y ⊔ x \ y) ⊓ y \ x := by rw [sup_inf_sdiff]
_ = x ⊓ y ⊓ y \ x ⊔ x \ y ⊓ y \ x := by rw [inf_sup_right]
_ = ⊥ := by rw [inf_comm x y, inf_inf_sdiff, sdiff_inf_sdiff, bot_sup_eq]
#align inf_sdiff_self_right inf_sdiff_self_right
@[simp]
theorem inf_sdiff_self_left : y \ x ⊓ x = ⊥ := by rw [inf_comm, inf_sdiff_self_right]
#align inf_sdiff_self_left inf_sdiff_self_left
-- see Note [lower instance priority]
instance (priority := 100) GeneralizedBooleanAlgebra.toGeneralizedCoheytingAlgebra :
GeneralizedCoheytingAlgebra α where
__ := ‹GeneralizedBooleanAlgebra α›
__ := GeneralizedBooleanAlgebra.toOrderBot
sdiff := (· \ ·)
sdiff_le_iff y x z :=
⟨fun h =>
le_of_inf_le_sup_le
(le_of_eq
(calc
y ⊓ y \ x = y \ x := inf_of_le_right sdiff_le'
_ = x ⊓ y \ x ⊔ z ⊓ y \ x := by
rw [inf_eq_right.2 h, inf_sdiff_self_right, bot_sup_eq]
_ = (x ⊔ z) ⊓ y \ x := by rw [← inf_sup_right]))
(calc
y ⊔ y \ x = y := sup_of_le_left sdiff_le'
_ ≤ y ⊔ (x ⊔ z) := le_sup_left
_ = y \ x ⊔ x ⊔ z := by rw [← sup_assoc, ← @sdiff_sup_self' _ x y]
_ = x ⊔ z ⊔ y \ x := by ac_rfl),
fun h =>
le_of_inf_le_sup_le
(calc
y \ x ⊓ x = ⊥ := inf_sdiff_self_left
_ ≤ z ⊓ x := bot_le)
(calc
y \ x ⊔ x = y ⊔ x := sdiff_sup_self'
_ ≤ x ⊔ z ⊔ x := sup_le_sup_right h x
_ ≤ z ⊔ x := by rw [sup_assoc, sup_comm, sup_assoc, sup_idem])⟩
#align generalized_boolean_algebra.to_generalized_coheyting_algebra GeneralizedBooleanAlgebra.toGeneralizedCoheytingAlgebra
theorem disjoint_sdiff_self_left : Disjoint (y \ x) x :=
disjoint_iff_inf_le.mpr inf_sdiff_self_left.le
#align disjoint_sdiff_self_left disjoint_sdiff_self_left
theorem disjoint_sdiff_self_right : Disjoint x (y \ x) :=
disjoint_iff_inf_le.mpr inf_sdiff_self_right.le
#align disjoint_sdiff_self_right disjoint_sdiff_self_right
lemma le_sdiff : x ≤ y \ z ↔ x ≤ y ∧ Disjoint x z :=
⟨fun h ↦ ⟨h.trans sdiff_le, disjoint_sdiff_self_left.mono_left h⟩, fun h ↦
by rw [← h.2.sdiff_eq_left]; exact sdiff_le_sdiff_right h.1⟩
#align le_sdiff le_sdiff
@[simp] lemma sdiff_eq_left : x \ y = x ↔ Disjoint x y :=
⟨fun h ↦ disjoint_sdiff_self_left.mono_left h.ge, Disjoint.sdiff_eq_left⟩
#align sdiff_eq_left sdiff_eq_left
theorem Disjoint.sdiff_eq_of_sup_eq (hi : Disjoint x z) (hs : x ⊔ z = y) : y \ x = z :=
have h : y ⊓ x = x := inf_eq_right.2 <| le_sup_left.trans hs.le
sdiff_unique (by rw [h, hs]) (by rw [h, hi.eq_bot])
#align disjoint.sdiff_eq_of_sup_eq Disjoint.sdiff_eq_of_sup_eq
protected theorem Disjoint.sdiff_unique (hd : Disjoint x z) (hz : z ≤ y) (hs : y ≤ x ⊔ z) :
y \ x = z :=
sdiff_unique
(by
rw [← inf_eq_right] at hs
rwa [sup_inf_right, inf_sup_right, sup_comm x, inf_sup_self, inf_comm, sup_comm z,
hs, sup_eq_left])
(by rw [inf_assoc, hd.eq_bot, inf_bot_eq])
#align disjoint.sdiff_unique Disjoint.sdiff_unique
-- cf. `IsCompl.disjoint_left_iff` and `IsCompl.disjoint_right_iff`
theorem disjoint_sdiff_iff_le (hz : z ≤ y) (hx : x ≤ y) : Disjoint z (y \ x) ↔ z ≤ x :=
⟨fun H =>
le_of_inf_le_sup_le (le_trans H.le_bot bot_le)
(by
rw [sup_sdiff_cancel_right hx]
refine le_trans (sup_le_sup_left sdiff_le z) ?_
rw [sup_eq_right.2 hz]),
fun H => disjoint_sdiff_self_right.mono_left H⟩
#align disjoint_sdiff_iff_le disjoint_sdiff_iff_le
-- cf. `IsCompl.le_left_iff` and `IsCompl.le_right_iff`
theorem le_iff_disjoint_sdiff (hz : z ≤ y) (hx : x ≤ y) : z ≤ x ↔ Disjoint z (y \ x) :=
(disjoint_sdiff_iff_le hz hx).symm
#align le_iff_disjoint_sdiff le_iff_disjoint_sdiff
-- cf. `IsCompl.inf_left_eq_bot_iff` and `IsCompl.inf_right_eq_bot_iff`
| Mathlib/Order/BooleanAlgebra.lean | 261 | 263 | theorem inf_sdiff_eq_bot_iff (hz : z ≤ y) (hx : x ≤ y) : z ⊓ y \ x = ⊥ ↔ z ≤ x := by |
rw [← disjoint_iff]
exact disjoint_sdiff_iff_le hz hx
|
import Mathlib.Algebra.MvPolynomial.Expand
import Mathlib.FieldTheory.Finite.Basic
import Mathlib.RingTheory.MvPolynomial.Basic
#align_import field_theory.finite.polynomial from "leanprover-community/mathlib"@"5aa3c1de9f3c642eac76e11071c852766f220fd0"
namespace MvPolynomial
variable {σ : Type*}
theorem C_dvd_iff_zmod (n : ℕ) (φ : MvPolynomial σ ℤ) :
C (n : ℤ) ∣ φ ↔ map (Int.castRingHom (ZMod n)) φ = 0 :=
C_dvd_iff_map_hom_eq_zero _ _ (CharP.intCast_eq_zero_iff (ZMod n) n) _
set_option linter.uppercaseLean3 false in
#align mv_polynomial.C_dvd_iff_zmod MvPolynomial.C_dvd_iff_zmod
namespace MvPolynomial
noncomputable section
open scoped Classical
open Set LinearMap Submodule
variable {K : Type*} {σ : Type*}
section Indicator
variable [Fintype K] [Fintype σ]
def indicator [CommRing K] (a : σ → K) : MvPolynomial σ K :=
∏ n, (1 - (X n - C (a n)) ^ (Fintype.card K - 1))
#align mv_polynomial.indicator MvPolynomial.indicator
section CommRing
variable [CommRing K]
| Mathlib/FieldTheory/Finite/Polynomial.lean | 72 | 76 | theorem eval_indicator_apply_eq_one (a : σ → K) : eval a (indicator a) = 1 := by |
nontriviality
have : 0 < Fintype.card K - 1 := tsub_pos_of_lt Fintype.one_lt_card
simp only [indicator, map_prod, map_sub, map_one, map_pow, eval_X, eval_C, sub_self,
zero_pow this.ne', sub_zero, Finset.prod_const_one]
|
import Mathlib.Algebra.Algebra.Equiv
import Mathlib.Algebra.Algebra.NonUnitalHom
import Mathlib.Algebra.BigOperators.Finsupp
import Mathlib.Algebra.Module.BigOperators
import Mathlib.Data.Finsupp.Basic
import Mathlib.LinearAlgebra.Finsupp
#align_import algebra.monoid_algebra.basic from "leanprover-community/mathlib"@"949dc57e616a621462062668c9f39e4e17b64b69"
noncomputable section
open Finset
open Finsupp hiding single mapDomain
universe u₁ u₂ u₃ u₄
variable (k : Type u₁) (G : Type u₂) (H : Type*) {R : Type*}
section
variable [Semiring k]
def MonoidAlgebra : Type max u₁ u₂ :=
G →₀ k
#align monoid_algebra MonoidAlgebra
-- Porting note: The compiler couldn't derive this.
instance MonoidAlgebra.inhabited : Inhabited (MonoidAlgebra k G) :=
inferInstanceAs (Inhabited (G →₀ k))
#align monoid_algebra.inhabited MonoidAlgebra.inhabited
-- Porting note: The compiler couldn't derive this.
instance MonoidAlgebra.addCommMonoid : AddCommMonoid (MonoidAlgebra k G) :=
inferInstanceAs (AddCommMonoid (G →₀ k))
#align monoid_algebra.add_comm_monoid MonoidAlgebra.addCommMonoid
instance MonoidAlgebra.instIsCancelAdd [IsCancelAdd k] : IsCancelAdd (MonoidAlgebra k G) :=
inferInstanceAs (IsCancelAdd (G →₀ k))
instance MonoidAlgebra.coeFun : CoeFun (MonoidAlgebra k G) fun _ => G → k :=
Finsupp.instCoeFun
#align monoid_algebra.has_coe_to_fun MonoidAlgebra.coeFun
end
namespace MonoidAlgebra
variable {k G}
section
variable [Semiring k] [NonUnitalNonAssocSemiring R]
-- Porting note: `reducible` cannot be `local`, so we replace some definitions and theorems with
-- new ones which have new types.
abbrev single (a : G) (b : k) : MonoidAlgebra k G := Finsupp.single a b
theorem single_zero (a : G) : (single a 0 : MonoidAlgebra k G) = 0 := Finsupp.single_zero a
theorem single_add (a : G) (b₁ b₂ : k) : single a (b₁ + b₂) = single a b₁ + single a b₂ :=
Finsupp.single_add a b₁ b₂
@[simp]
theorem sum_single_index {N} [AddCommMonoid N] {a : G} {b : k} {h : G → k → N}
(h_zero : h a 0 = 0) :
(single a b).sum h = h a b := Finsupp.sum_single_index h_zero
@[simp]
theorem sum_single (f : MonoidAlgebra k G) : f.sum single = f :=
Finsupp.sum_single f
theorem single_apply {a a' : G} {b : k} [Decidable (a = a')] :
single a b a' = if a = a' then b else 0 :=
Finsupp.single_apply
@[simp]
theorem single_eq_zero {a : G} {b : k} : single a b = 0 ↔ b = 0 := Finsupp.single_eq_zero
abbrev mapDomain {G' : Type*} (f : G → G') (v : MonoidAlgebra k G) : MonoidAlgebra k G' :=
Finsupp.mapDomain f v
theorem mapDomain_sum {k' G' : Type*} [Semiring k'] {f : G → G'} {s : MonoidAlgebra k' G}
{v : G → k' → MonoidAlgebra k G} :
mapDomain f (s.sum v) = s.sum fun a b => mapDomain f (v a b) :=
Finsupp.mapDomain_sum
def liftNC (f : k →+ R) (g : G → R) : MonoidAlgebra k G →+ R :=
liftAddHom fun x : G => (AddMonoidHom.mulRight (g x)).comp f
#align monoid_algebra.lift_nc MonoidAlgebra.liftNC
@[simp]
theorem liftNC_single (f : k →+ R) (g : G → R) (a : G) (b : k) :
liftNC f g (single a b) = f b * g a :=
liftAddHom_apply_single _ _ _
#align monoid_algebra.lift_nc_single MonoidAlgebra.liftNC_single
end
instance nonUnitalCommSemiring [CommSemiring k] [CommSemigroup G] :
NonUnitalCommSemiring (MonoidAlgebra k G) :=
{ MonoidAlgebra.nonUnitalSemiring with
mul_comm := fun f g => by
simp only [mul_def, Finsupp.sum, mul_comm]
rw [Finset.sum_comm]
simp only [mul_comm] }
#align monoid_algebra.non_unital_comm_semiring MonoidAlgebra.nonUnitalCommSemiring
instance nontrivial [Semiring k] [Nontrivial k] [Nonempty G] : Nontrivial (MonoidAlgebra k G) :=
Finsupp.instNontrivial
#align monoid_algebra.nontrivial MonoidAlgebra.nontrivial
section
-- attribute [local reducible] MonoidAlgebra -- Porting note: `reducible` cannot be `local`.
variable (k)
def GroupSMul.linearMap [Monoid G] [CommSemiring k] (V : Type u₃) [AddCommMonoid V] [Module k V]
[Module (MonoidAlgebra k G) V] [IsScalarTower k (MonoidAlgebra k G) V] (g : G) : V →ₗ[k] V where
toFun v := single g (1 : k) • v
map_add' x y := smul_add (single g (1 : k)) x y
map_smul' _c _x := smul_algebra_smul_comm _ _ _
#align monoid_algebra.group_smul.linear_map MonoidAlgebra.GroupSMul.linearMap
@[simp]
theorem GroupSMul.linearMap_apply [Monoid G] [CommSemiring k] (V : Type u₃) [AddCommMonoid V]
[Module k V] [Module (MonoidAlgebra k G) V] [IsScalarTower k (MonoidAlgebra k G) V] (g : G)
(v : V) : (GroupSMul.linearMap k V g) v = single g (1 : k) • v :=
rfl
#align monoid_algebra.group_smul.linear_map_apply MonoidAlgebra.GroupSMul.linearMap_apply
section
variable {k}
variable [Monoid G] [CommSemiring k] {V : Type u₃} {W : Type u₄} [AddCommMonoid V] [Module k V]
[Module (MonoidAlgebra k G) V] [IsScalarTower k (MonoidAlgebra k G) V] [AddCommMonoid W]
[Module k W] [Module (MonoidAlgebra k G) W] [IsScalarTower k (MonoidAlgebra k G) W]
(f : V →ₗ[k] W)
(h : ∀ (g : G) (v : V), f (single g (1 : k) • v) = single g (1 : k) • f v)
def equivariantOfLinearOfComm : V →ₗ[MonoidAlgebra k G] W where
toFun := f
map_add' v v' := by simp
map_smul' c v := by
-- Porting note: Was `apply`.
refine Finsupp.induction c ?_ ?_
· simp
· intro g r c' _nm _nz w
dsimp at *
simp only [add_smul, f.map_add, w, add_left_inj, single_eq_algebraMap_mul_of, ← smul_smul]
erw [algebraMap_smul (MonoidAlgebra k G) r, algebraMap_smul (MonoidAlgebra k G) r, f.map_smul,
h g v, of_apply]
#align monoid_algebra.equivariant_of_linear_of_comm MonoidAlgebra.equivariantOfLinearOfComm
@[simp]
theorem equivariantOfLinearOfComm_apply (v : V) : (equivariantOfLinearOfComm f h) v = f v :=
rfl
#align monoid_algebra.equivariant_of_linear_of_comm_apply MonoidAlgebra.equivariantOfLinearOfComm_apply
end
end
section
universe ui
variable {ι : Type ui}
-- attribute [local reducible] MonoidAlgebra -- Porting note: `reducible` cannot be `local`.
theorem prod_single [CommSemiring k] [CommMonoid G] {s : Finset ι} {a : ι → G} {b : ι → k} :
(∏ i ∈ s, single (a i) (b i)) = single (∏ i ∈ s, a i) (∏ i ∈ s, b i) :=
Finset.cons_induction_on s rfl fun a s has ih => by
rw [prod_cons has, ih, single_mul_single, prod_cons has, prod_cons has]
#align monoid_algebra.prod_single MonoidAlgebra.prod_single
end
section
-- We now prove some additional statements that hold for group algebras.
variable [Semiring k] [Group G]
-- attribute [local reducible] MonoidAlgebra -- Porting note: `reducible` cannot be `local`.
@[simp]
theorem mul_single_apply (f : MonoidAlgebra k G) (r : k) (x y : G) :
(f * single x r) y = f (y * x⁻¹) * r :=
f.mul_single_apply_aux fun _a => eq_mul_inv_iff_mul_eq.symm
#align monoid_algebra.mul_single_apply MonoidAlgebra.mul_single_apply
@[simp]
theorem single_mul_apply (r : k) (x : G) (f : MonoidAlgebra k G) (y : G) :
(single x r * f) y = r * f (x⁻¹ * y) :=
f.single_mul_apply_aux fun _z => eq_inv_mul_iff_mul_eq.symm
#align monoid_algebra.single_mul_apply MonoidAlgebra.single_mul_apply
theorem mul_apply_left (f g : MonoidAlgebra k G) (x : G) :
(f * g) x = f.sum fun a b => b * g (a⁻¹ * x) :=
calc
(f * g) x = sum f fun a b => (single a b * g) x := by
rw [← Finsupp.sum_apply, ← Finsupp.sum_mul g f, f.sum_single]
_ = _ := by simp only [single_mul_apply, Finsupp.sum]
#align monoid_algebra.mul_apply_left MonoidAlgebra.mul_apply_left
-- If we'd assumed `CommSemiring`, we could deduce this from `mul_apply_left`.
theorem mul_apply_right (f g : MonoidAlgebra k G) (x : G) :
(f * g) x = g.sum fun a b => f (x * a⁻¹) * b :=
calc
(f * g) x = sum g fun a b => (f * single a b) x := by
rw [← Finsupp.sum_apply, ← Finsupp.mul_sum f g, g.sum_single]
_ = _ := by simp only [mul_single_apply, Finsupp.sum]
#align monoid_algebra.mul_apply_right MonoidAlgebra.mul_apply_right
end
section
variable [Semiring k]
def AddMonoidAlgebra :=
G →₀ k
#align add_monoid_algebra AddMonoidAlgebra
@[inherit_doc]
scoped[AddMonoidAlgebra] notation:9000 R:max "[" A "]" => AddMonoidAlgebra R A
section MiscTheorems
variable [Semiring k]
theorem mul_apply [DecidableEq G] [Add G] (f g : k[G]) (x : G) :
(f * g) x = f.sum fun a₁ b₁ => g.sum fun a₂ b₂ => if a₁ + a₂ = x then b₁ * b₂ else 0 :=
@MonoidAlgebra.mul_apply k (Multiplicative G) _ _ _ _ _ _
#align add_monoid_algebra.mul_apply AddMonoidAlgebra.mul_apply
theorem mul_apply_antidiagonal [Add G] (f g : k[G]) (x : G) (s : Finset (G × G))
(hs : ∀ {p : G × G}, p ∈ s ↔ p.1 + p.2 = x) : (f * g) x = ∑ p ∈ s, f p.1 * g p.2 :=
@MonoidAlgebra.mul_apply_antidiagonal k (Multiplicative G) _ _ _ _ _ s @hs
#align add_monoid_algebra.mul_apply_antidiagonal AddMonoidAlgebra.mul_apply_antidiagonal
theorem single_mul_single [Add G] {a₁ a₂ : G} {b₁ b₂ : k} :
single a₁ b₁ * single a₂ b₂ = single (a₁ + a₂) (b₁ * b₂) :=
@MonoidAlgebra.single_mul_single k (Multiplicative G) _ _ _ _ _ _
#align add_monoid_algebra.single_mul_single AddMonoidAlgebra.single_mul_single
theorem single_commute_single [Add G] {a₁ a₂ : G} {b₁ b₂ : k}
(ha : AddCommute a₁ a₂) (hb : Commute b₁ b₂) :
Commute (single a₁ b₁) (single a₂ b₂) :=
@MonoidAlgebra.single_commute_single k (Multiplicative G) _ _ _ _ _ _ ha hb
-- This should be a `@[simp]` lemma, but the simp_nf linter times out if we add this.
-- Probably the correct fix is to make a `[Add]MonoidAlgebra.single` with the correct type,
-- instead of relying on `Finsupp.single`.
theorem single_pow [AddMonoid G] {a : G} {b : k} : ∀ n : ℕ, single a b ^ n = single (n • a) (b ^ n)
| 0 => by
simp only [pow_zero, zero_nsmul]
rfl
| n + 1 => by
rw [pow_succ, pow_succ, single_pow n, single_mul_single, add_nsmul, one_nsmul]
#align add_monoid_algebra.single_pow AddMonoidAlgebra.single_pow
@[simp]
| Mathlib/Algebra/MonoidAlgebra/Basic.lean | 1,610 | 1,614 | theorem mapDomain_one {α : Type*} {β : Type*} {α₂ : Type*} [Semiring β] [Zero α] [Zero α₂]
{F : Type*} [FunLike F α α₂] [ZeroHomClass F α α₂] (f : F) :
(mapDomain f (1 : AddMonoidAlgebra β α) : AddMonoidAlgebra β α₂) =
(1 : AddMonoidAlgebra β α₂) := by |
simp_rw [one_def, mapDomain_single, map_zero]
|
import Mathlib.Data.Setoid.Partition
import Mathlib.GroupTheory.GroupAction.Basic
import Mathlib.GroupTheory.GroupAction.Pointwise
import Mathlib.GroupTheory.GroupAction.SubMulAction
open scoped BigOperators Pointwise
namespace MulAction
section orbits
variable {G : Type*} [Group G] {X : Type*} [MulAction G X]
theorem orbit.eq_or_disjoint (a b : X) :
orbit G a = orbit G b ∨ Disjoint (orbit G a) (orbit G b) := by
apply (em (Disjoint (orbit G a) (orbit G b))).symm.imp _ id
simp (config := { contextual := true })
only [Set.not_disjoint_iff, ← orbit_eq_iff, forall_exists_index, and_imp, eq_comm, implies_true]
theorem orbit.pairwiseDisjoint :
(Set.range fun x : X => orbit G x).PairwiseDisjoint id := by
rintro s ⟨x, rfl⟩ t ⟨y, rfl⟩ h
contrapose! h
exact (orbit.eq_or_disjoint x y).resolve_right h
| Mathlib/GroupTheory/GroupAction/Blocks.lean | 51 | 57 | theorem IsPartition.of_orbits :
Setoid.IsPartition (Set.range fun a : X => orbit G a) := by |
apply orbit.pairwiseDisjoint.isPartition_of_exists_of_ne_empty
· intro x
exact ⟨_, ⟨x, rfl⟩, mem_orbit_self x⟩
· rintro ⟨a, ha : orbit G a = ∅⟩
exact (MulAction.orbit_nonempty a).ne_empty ha
|
import Mathlib.RingTheory.DedekindDomain.Ideal
import Mathlib.RingTheory.IsAdjoinRoot
#align_import number_theory.kummer_dedekind from "leanprover-community/mathlib"@"65a1391a0106c9204fe45bc73a039f056558cb83"
variable (R : Type*) {S : Type*} [CommRing R] [CommRing S] [Algebra R S]
open Ideal Polynomial DoubleQuot UniqueFactorizationMonoid Algebra RingHom
local notation:max R "<" x:max ">" => adjoin R ({x} : Set S)
def conductor (x : S) : Ideal S where
carrier := {a | ∀ b : S, a * b ∈ R<x>}
zero_mem' b := by simpa only [zero_mul] using Subalgebra.zero_mem _
add_mem' ha hb c := by simpa only [add_mul] using Subalgebra.add_mem _ (ha c) (hb c)
smul_mem' c a ha b := by simpa only [smul_eq_mul, mul_left_comm, mul_assoc] using ha (c * b)
#align conductor conductor
variable {R} {x : S}
theorem conductor_eq_of_eq {y : S} (h : (R<x> : Set S) = R<y>) : conductor R x = conductor R y :=
Ideal.ext fun _ => forall_congr' fun _ => Set.ext_iff.mp h _
#align conductor_eq_of_eq conductor_eq_of_eq
theorem conductor_subset_adjoin : (conductor R x : Set S) ⊆ R<x> := fun y hy => by
simpa only [mul_one] using hy 1
#align conductor_subset_adjoin conductor_subset_adjoin
theorem mem_conductor_iff {y : S} : y ∈ conductor R x ↔ ∀ b : S, y * b ∈ R<x> :=
⟨fun h => h, fun h => h⟩
#align mem_conductor_iff mem_conductor_iff
theorem conductor_eq_top_of_adjoin_eq_top (h : R<x> = ⊤) : conductor R x = ⊤ := by
simp only [Ideal.eq_top_iff_one, mem_conductor_iff, h, mem_top, forall_const]
#align conductor_eq_top_of_adjoin_eq_top conductor_eq_top_of_adjoin_eq_top
theorem conductor_eq_top_of_powerBasis (pb : PowerBasis R S) : conductor R pb.gen = ⊤ :=
conductor_eq_top_of_adjoin_eq_top pb.adjoin_gen_eq_top
#align conductor_eq_top_of_power_basis conductor_eq_top_of_powerBasis
open IsLocalization in
lemma mem_coeSubmodule_conductor {L} [CommRing L] [Algebra S L] [Algebra R L]
[IsScalarTower R S L] [NoZeroSMulDivisors S L] {x : S} {y : L} :
y ∈ coeSubmodule L (conductor R x) ↔ ∀ z : S,
y * (algebraMap S L) z ∈ Algebra.adjoin R {algebraMap S L x} := by
cases subsingleton_or_nontrivial L
· rw [Subsingleton.elim (coeSubmodule L _) ⊤, Subsingleton.elim (Algebra.adjoin R _) ⊤]; simp
trans ∀ z, y * (algebraMap S L) z ∈ (Algebra.adjoin R {x}).map (IsScalarTower.toAlgHom R S L)
· simp only [coeSubmodule, Submodule.mem_map, Algebra.linearMap_apply, Subalgebra.mem_map,
IsScalarTower.coe_toAlgHom']
constructor
· rintro ⟨y, hy, rfl⟩ z
exact ⟨_, hy z, map_mul _ _ _⟩
· intro H
obtain ⟨y, _, e⟩ := H 1
rw [_root_.map_one, mul_one] at e
subst e
simp only [← _root_.map_mul, (NoZeroSMulDivisors.algebraMap_injective S L).eq_iff,
exists_eq_right] at H
exact ⟨_, H, rfl⟩
· rw [AlgHom.map_adjoin, Set.image_singleton]; rfl
variable {I : Ideal R}
| Mathlib/NumberTheory/KummerDedekind.lean | 119 | 148 | theorem prod_mem_ideal_map_of_mem_conductor {p : R} {z : S}
(hp : p ∈ Ideal.comap (algebraMap R S) (conductor R x)) (hz' : z ∈ I.map (algebraMap R S)) :
algebraMap R S p * z ∈ algebraMap R<x> S '' ↑(I.map (algebraMap R R<x>)) := by |
rw [Ideal.map, Ideal.span, Finsupp.mem_span_image_iff_total] at hz'
obtain ⟨l, H, H'⟩ := hz'
rw [Finsupp.total_apply] at H'
rw [← H', mul_comm, Finsupp.sum_mul]
have lem : ∀ {a : R}, a ∈ I → l a • algebraMap R S a * algebraMap R S p ∈
algebraMap R<x> S '' I.map (algebraMap R R<x>) := by
intro a ha
rw [Algebra.id.smul_eq_mul, mul_assoc, mul_comm, mul_assoc, Set.mem_image]
refine Exists.intro
(algebraMap R R<x> a * ⟨l a * algebraMap R S p,
show l a * algebraMap R S p ∈ R<x> from ?h⟩) ?_
case h =>
rw [mul_comm]
exact mem_conductor_iff.mp (Ideal.mem_comap.mp hp) _
· refine ⟨?_, ?_⟩
· rw [mul_comm]
apply Ideal.mul_mem_left (I.map (algebraMap R R<x>)) _ (Ideal.mem_map_of_mem _ ha)
· simp only [RingHom.map_mul, mul_comm (algebraMap R S p) (l a)]
rfl
refine Finset.sum_induction _ (fun u => u ∈ algebraMap R<x> S '' I.map (algebraMap R R<x>))
(fun a b => ?_) ?_ ?_
· rintro ⟨z, hz, rfl⟩ ⟨y, hy, rfl⟩
rw [← RingHom.map_add]
exact ⟨z + y, Ideal.add_mem _ (SetLike.mem_coe.mp hz) hy, rfl⟩
· exact ⟨0, SetLike.mem_coe.mpr <| Ideal.zero_mem _, RingHom.map_zero _⟩
· intro y hy
exact lem ((Finsupp.mem_supported _ l).mp H hy)
|
import Mathlib.Data.Fintype.BigOperators
import Mathlib.Data.Finsupp.Defs
import Mathlib.Data.Nat.Cast.Order
import Mathlib.Data.Set.Countable
import Mathlib.Logic.Small.Set
import Mathlib.Order.SuccPred.CompleteLinearOrder
import Mathlib.SetTheory.Cardinal.SchroederBernstein
#align_import set_theory.cardinal.basic from "leanprover-community/mathlib"@"3ff3f2d6a3118b8711063de7111a0d77a53219a8"
assert_not_exists Field
assert_not_exists Module
open scoped Classical
open Function Set Order
noncomputable section
universe u v w
variable {α β : Type u}
instance Cardinal.isEquivalent : Setoid (Type u) where
r α β := Nonempty (α ≃ β)
iseqv := ⟨
fun α => ⟨Equiv.refl α⟩,
fun ⟨e⟩ => ⟨e.symm⟩,
fun ⟨e₁⟩ ⟨e₂⟩ => ⟨e₁.trans e₂⟩⟩
#align cardinal.is_equivalent Cardinal.isEquivalent
@[pp_with_univ]
def Cardinal : Type (u + 1) :=
Quotient Cardinal.isEquivalent
#align cardinal Cardinal
namespace Cardinal
def mk : Type u → Cardinal :=
Quotient.mk'
#align cardinal.mk Cardinal.mk
@[inherit_doc]
scoped prefix:max "#" => Cardinal.mk
instance canLiftCardinalType : CanLift Cardinal.{u} (Type u) mk fun _ => True :=
⟨fun c _ => Quot.inductionOn c fun α => ⟨α, rfl⟩⟩
#align cardinal.can_lift_cardinal_Type Cardinal.canLiftCardinalType
@[elab_as_elim]
theorem inductionOn {p : Cardinal → Prop} (c : Cardinal) (h : ∀ α, p #α) : p c :=
Quotient.inductionOn c h
#align cardinal.induction_on Cardinal.inductionOn
@[elab_as_elim]
theorem inductionOn₂ {p : Cardinal → Cardinal → Prop} (c₁ : Cardinal) (c₂ : Cardinal)
(h : ∀ α β, p #α #β) : p c₁ c₂ :=
Quotient.inductionOn₂ c₁ c₂ h
#align cardinal.induction_on₂ Cardinal.inductionOn₂
@[elab_as_elim]
theorem inductionOn₃ {p : Cardinal → Cardinal → Cardinal → Prop} (c₁ : Cardinal) (c₂ : Cardinal)
(c₃ : Cardinal) (h : ∀ α β γ, p #α #β #γ) : p c₁ c₂ c₃ :=
Quotient.inductionOn₃ c₁ c₂ c₃ h
#align cardinal.induction_on₃ Cardinal.inductionOn₃
protected theorem eq : #α = #β ↔ Nonempty (α ≃ β) :=
Quotient.eq'
#align cardinal.eq Cardinal.eq
@[simp]
theorem mk'_def (α : Type u) : @Eq Cardinal ⟦α⟧ #α :=
rfl
#align cardinal.mk_def Cardinal.mk'_def
@[simp]
theorem mk_out (c : Cardinal) : #c.out = c :=
Quotient.out_eq _
#align cardinal.mk_out Cardinal.mk_out
def outMkEquiv {α : Type v} : (#α).out ≃ α :=
Nonempty.some <| Cardinal.eq.mp (by simp)
#align cardinal.out_mk_equiv Cardinal.outMkEquiv
theorem mk_congr (e : α ≃ β) : #α = #β :=
Quot.sound ⟨e⟩
#align cardinal.mk_congr Cardinal.mk_congr
alias _root_.Equiv.cardinal_eq := mk_congr
#align equiv.cardinal_eq Equiv.cardinal_eq
def map (f : Type u → Type v) (hf : ∀ α β, α ≃ β → f α ≃ f β) : Cardinal.{u} → Cardinal.{v} :=
Quotient.map f fun α β ⟨e⟩ => ⟨hf α β e⟩
#align cardinal.map Cardinal.map
@[simp]
theorem map_mk (f : Type u → Type v) (hf : ∀ α β, α ≃ β → f α ≃ f β) (α : Type u) :
map f hf #α = #(f α) :=
rfl
#align cardinal.map_mk Cardinal.map_mk
def map₂ (f : Type u → Type v → Type w) (hf : ∀ α β γ δ, α ≃ β → γ ≃ δ → f α γ ≃ f β δ) :
Cardinal.{u} → Cardinal.{v} → Cardinal.{w} :=
Quotient.map₂ f fun α β ⟨e₁⟩ γ δ ⟨e₂⟩ => ⟨hf α β γ δ e₁ e₂⟩
#align cardinal.map₂ Cardinal.map₂
@[pp_with_univ]
def lift (c : Cardinal.{v}) : Cardinal.{max v u} :=
map ULift.{u, v} (fun _ _ e => Equiv.ulift.trans <| e.trans Equiv.ulift.symm) c
#align cardinal.lift Cardinal.lift
@[simp]
theorem mk_uLift (α) : #(ULift.{v, u} α) = lift.{v} #α :=
rfl
#align cardinal.mk_ulift Cardinal.mk_uLift
-- Porting note: simpNF is not happy with universe levels, but this is needed as simp lemma
-- further down in this file
@[simp, nolint simpNF]
theorem lift_umax : lift.{max u v, u} = lift.{v, u} :=
funext fun a => inductionOn a fun _ => (Equiv.ulift.trans Equiv.ulift.symm).cardinal_eq
#align cardinal.lift_umax Cardinal.lift_umax
-- Porting note: simpNF is not happy with universe levels, but this is needed as simp lemma
-- further down in this file
@[simp, nolint simpNF]
theorem lift_umax' : lift.{max v u, u} = lift.{v, u} :=
lift_umax
#align cardinal.lift_umax' Cardinal.lift_umax'
-- Porting note: simpNF is not happy with universe levels, but this is needed as simp lemma
-- further down in this file
@[simp, nolint simpNF]
theorem lift_id' (a : Cardinal.{max u v}) : lift.{u} a = a :=
inductionOn a fun _ => mk_congr Equiv.ulift
#align cardinal.lift_id' Cardinal.lift_id'
@[simp]
theorem lift_id (a : Cardinal) : lift.{u, u} a = a :=
lift_id'.{u, u} a
#align cardinal.lift_id Cardinal.lift_id
-- porting note (#10618): simp can prove this
-- @[simp]
theorem lift_uzero (a : Cardinal.{u}) : lift.{0} a = a :=
lift_id'.{0, u} a
#align cardinal.lift_uzero Cardinal.lift_uzero
@[simp]
theorem lift_lift.{u_1} (a : Cardinal.{u_1}) : lift.{w} (lift.{v} a) = lift.{max v w} a :=
inductionOn a fun _ => (Equiv.ulift.trans <| Equiv.ulift.trans Equiv.ulift.symm).cardinal_eq
#align cardinal.lift_lift Cardinal.lift_lift
instance : LE Cardinal.{u} :=
⟨fun q₁ q₂ =>
Quotient.liftOn₂ q₁ q₂ (fun α β => Nonempty <| α ↪ β) fun _ _ _ _ ⟨e₁⟩ ⟨e₂⟩ =>
propext ⟨fun ⟨e⟩ => ⟨e.congr e₁ e₂⟩, fun ⟨e⟩ => ⟨e.congr e₁.symm e₂.symm⟩⟩⟩
instance partialOrder : PartialOrder Cardinal.{u} where
le := (· ≤ ·)
le_refl := by
rintro ⟨α⟩
exact ⟨Embedding.refl _⟩
le_trans := by
rintro ⟨α⟩ ⟨β⟩ ⟨γ⟩ ⟨e₁⟩ ⟨e₂⟩
exact ⟨e₁.trans e₂⟩
le_antisymm := by
rintro ⟨α⟩ ⟨β⟩ ⟨e₁⟩ ⟨e₂⟩
exact Quotient.sound (e₁.antisymm e₂)
instance linearOrder : LinearOrder Cardinal.{u} :=
{ Cardinal.partialOrder with
le_total := by
rintro ⟨α⟩ ⟨β⟩
apply Embedding.total
decidableLE := Classical.decRel _ }
theorem le_def (α β : Type u) : #α ≤ #β ↔ Nonempty (α ↪ β) :=
Iff.rfl
#align cardinal.le_def Cardinal.le_def
theorem mk_le_of_injective {α β : Type u} {f : α → β} (hf : Injective f) : #α ≤ #β :=
⟨⟨f, hf⟩⟩
#align cardinal.mk_le_of_injective Cardinal.mk_le_of_injective
theorem _root_.Function.Embedding.cardinal_le {α β : Type u} (f : α ↪ β) : #α ≤ #β :=
⟨f⟩
#align function.embedding.cardinal_le Function.Embedding.cardinal_le
theorem mk_le_of_surjective {α β : Type u} {f : α → β} (hf : Surjective f) : #β ≤ #α :=
⟨Embedding.ofSurjective f hf⟩
#align cardinal.mk_le_of_surjective Cardinal.mk_le_of_surjective
theorem le_mk_iff_exists_set {c : Cardinal} {α : Type u} : c ≤ #α ↔ ∃ p : Set α, #p = c :=
⟨inductionOn c fun _ ⟨⟨f, hf⟩⟩ => ⟨Set.range f, (Equiv.ofInjective f hf).cardinal_eq.symm⟩,
fun ⟨_, e⟩ => e ▸ ⟨⟨Subtype.val, fun _ _ => Subtype.eq⟩⟩⟩
#align cardinal.le_mk_iff_exists_set Cardinal.le_mk_iff_exists_set
theorem mk_subtype_le {α : Type u} (p : α → Prop) : #(Subtype p) ≤ #α :=
⟨Embedding.subtype p⟩
#align cardinal.mk_subtype_le Cardinal.mk_subtype_le
theorem mk_set_le (s : Set α) : #s ≤ #α :=
mk_subtype_le s
#align cardinal.mk_set_le Cardinal.mk_set_le
@[simp]
lemma mk_preimage_down {s : Set α} : #(ULift.down.{v} ⁻¹' s) = lift.{v} (#s) := by
rw [← mk_uLift, Cardinal.eq]
constructor
let f : ULift.down ⁻¹' s → ULift s := fun x ↦ ULift.up (restrictPreimage s ULift.down x)
have : Function.Bijective f :=
ULift.up_bijective.comp (restrictPreimage_bijective _ (ULift.down_bijective))
exact Equiv.ofBijective f this
theorem out_embedding {c c' : Cardinal} : c ≤ c' ↔ Nonempty (c.out ↪ c'.out) := by
trans
· rw [← Quotient.out_eq c, ← Quotient.out_eq c']
· rw [mk'_def, mk'_def, le_def]
#align cardinal.out_embedding Cardinal.out_embedding
theorem lift_mk_le {α : Type v} {β : Type w} :
lift.{max u w} #α ≤ lift.{max u v} #β ↔ Nonempty (α ↪ β) :=
⟨fun ⟨f⟩ => ⟨Embedding.congr Equiv.ulift Equiv.ulift f⟩, fun ⟨f⟩ =>
⟨Embedding.congr Equiv.ulift.symm Equiv.ulift.symm f⟩⟩
#align cardinal.lift_mk_le Cardinal.lift_mk_le
theorem lift_mk_le' {α : Type u} {β : Type v} : lift.{v} #α ≤ lift.{u} #β ↔ Nonempty (α ↪ β) :=
lift_mk_le.{0}
#align cardinal.lift_mk_le' Cardinal.lift_mk_le'
theorem lift_mk_eq {α : Type u} {β : Type v} :
lift.{max v w} #α = lift.{max u w} #β ↔ Nonempty (α ≃ β) :=
Quotient.eq'.trans
⟨fun ⟨f⟩ => ⟨Equiv.ulift.symm.trans <| f.trans Equiv.ulift⟩, fun ⟨f⟩ =>
⟨Equiv.ulift.trans <| f.trans Equiv.ulift.symm⟩⟩
#align cardinal.lift_mk_eq Cardinal.lift_mk_eq
theorem lift_mk_eq' {α : Type u} {β : Type v} : lift.{v} #α = lift.{u} #β ↔ Nonempty (α ≃ β) :=
lift_mk_eq.{u, v, 0}
#align cardinal.lift_mk_eq' Cardinal.lift_mk_eq'
@[simp]
theorem lift_le {a b : Cardinal.{v}} : lift.{u, v} a ≤ lift.{u, v} b ↔ a ≤ b :=
inductionOn₂ a b fun α β => by
rw [← lift_umax]
exact lift_mk_le.{u}
#align cardinal.lift_le Cardinal.lift_le
-- Porting note: changed `simps` to `simps!` because the linter told to do so.
@[simps! (config := .asFn)]
def liftOrderEmbedding : Cardinal.{v} ↪o Cardinal.{max v u} :=
OrderEmbedding.ofMapLEIff lift.{u, v} fun _ _ => lift_le
#align cardinal.lift_order_embedding Cardinal.liftOrderEmbedding
theorem lift_injective : Injective lift.{u, v} :=
liftOrderEmbedding.injective
#align cardinal.lift_injective Cardinal.lift_injective
@[simp]
theorem lift_inj {a b : Cardinal.{u}} : lift.{v, u} a = lift.{v, u} b ↔ a = b :=
lift_injective.eq_iff
#align cardinal.lift_inj Cardinal.lift_inj
@[simp]
theorem lift_lt {a b : Cardinal.{u}} : lift.{v, u} a < lift.{v, u} b ↔ a < b :=
liftOrderEmbedding.lt_iff_lt
#align cardinal.lift_lt Cardinal.lift_lt
theorem lift_strictMono : StrictMono lift := fun _ _ => lift_lt.2
#align cardinal.lift_strict_mono Cardinal.lift_strictMono
theorem lift_monotone : Monotone lift :=
lift_strictMono.monotone
#align cardinal.lift_monotone Cardinal.lift_monotone
instance : Zero Cardinal.{u} :=
-- `PEmpty` might be more canonical, but this is convenient for defeq with natCast
⟨lift #(Fin 0)⟩
instance : Inhabited Cardinal.{u} :=
⟨0⟩
@[simp]
theorem mk_eq_zero (α : Type u) [IsEmpty α] : #α = 0 :=
(Equiv.equivOfIsEmpty α (ULift (Fin 0))).cardinal_eq
#align cardinal.mk_eq_zero Cardinal.mk_eq_zero
@[simp]
theorem lift_zero : lift 0 = 0 := mk_eq_zero _
#align cardinal.lift_zero Cardinal.lift_zero
@[simp]
theorem lift_eq_zero {a : Cardinal.{v}} : lift.{u} a = 0 ↔ a = 0 :=
lift_injective.eq_iff' lift_zero
#align cardinal.lift_eq_zero Cardinal.lift_eq_zero
theorem mk_eq_zero_iff {α : Type u} : #α = 0 ↔ IsEmpty α :=
⟨fun e =>
let ⟨h⟩ := Quotient.exact e
h.isEmpty,
@mk_eq_zero α⟩
#align cardinal.mk_eq_zero_iff Cardinal.mk_eq_zero_iff
theorem mk_ne_zero_iff {α : Type u} : #α ≠ 0 ↔ Nonempty α :=
(not_iff_not.2 mk_eq_zero_iff).trans not_isEmpty_iff
#align cardinal.mk_ne_zero_iff Cardinal.mk_ne_zero_iff
@[simp]
theorem mk_ne_zero (α : Type u) [Nonempty α] : #α ≠ 0 :=
mk_ne_zero_iff.2 ‹_›
#align cardinal.mk_ne_zero Cardinal.mk_ne_zero
instance : One Cardinal.{u} :=
-- `PUnit` might be more canonical, but this is convenient for defeq with natCast
⟨lift #(Fin 1)⟩
instance : Nontrivial Cardinal.{u} :=
⟨⟨1, 0, mk_ne_zero _⟩⟩
theorem mk_eq_one (α : Type u) [Unique α] : #α = 1 :=
(Equiv.equivOfUnique α (ULift (Fin 1))).cardinal_eq
#align cardinal.mk_eq_one Cardinal.mk_eq_one
theorem le_one_iff_subsingleton {α : Type u} : #α ≤ 1 ↔ Subsingleton α :=
⟨fun ⟨f⟩ => ⟨fun _ _ => f.injective (Subsingleton.elim _ _)⟩, fun ⟨h⟩ =>
⟨fun _ => ULift.up 0, fun _ _ _ => h _ _⟩⟩
#align cardinal.le_one_iff_subsingleton Cardinal.le_one_iff_subsingleton
@[simp]
theorem mk_le_one_iff_set_subsingleton {s : Set α} : #s ≤ 1 ↔ s.Subsingleton :=
le_one_iff_subsingleton.trans s.subsingleton_coe
#align cardinal.mk_le_one_iff_set_subsingleton Cardinal.mk_le_one_iff_set_subsingleton
alias ⟨_, _root_.Set.Subsingleton.cardinal_mk_le_one⟩ := mk_le_one_iff_set_subsingleton
#align set.subsingleton.cardinal_mk_le_one Set.Subsingleton.cardinal_mk_le_one
instance : Add Cardinal.{u} :=
⟨map₂ Sum fun _ _ _ _ => Equiv.sumCongr⟩
theorem add_def (α β : Type u) : #α + #β = #(Sum α β) :=
rfl
#align cardinal.add_def Cardinal.add_def
instance : NatCast Cardinal.{u} :=
⟨fun n => lift #(Fin n)⟩
@[simp]
theorem mk_sum (α : Type u) (β : Type v) : #(α ⊕ β) = lift.{v, u} #α + lift.{u, v} #β :=
mk_congr (Equiv.ulift.symm.sumCongr Equiv.ulift.symm)
#align cardinal.mk_sum Cardinal.mk_sum
@[simp]
theorem mk_option {α : Type u} : #(Option α) = #α + 1 := by
rw [(Equiv.optionEquivSumPUnit.{u, u} α).cardinal_eq, mk_sum, mk_eq_one PUnit, lift_id, lift_id]
#align cardinal.mk_option Cardinal.mk_option
@[simp]
theorem mk_psum (α : Type u) (β : Type v) : #(PSum α β) = lift.{v} #α + lift.{u} #β :=
(mk_congr (Equiv.psumEquivSum α β)).trans (mk_sum α β)
#align cardinal.mk_psum Cardinal.mk_psum
@[simp]
theorem mk_fintype (α : Type u) [h : Fintype α] : #α = Fintype.card α :=
mk_congr (Fintype.equivOfCardEq (by simp))
protected theorem cast_succ (n : ℕ) : ((n + 1 : ℕ) : Cardinal.{u}) = n + 1 := by
change #(ULift.{u} (Fin (n+1))) = # (ULift.{u} (Fin n)) + 1
rw [← mk_option, mk_fintype, mk_fintype]
simp only [Fintype.card_ulift, Fintype.card_fin, Fintype.card_option]
instance : Mul Cardinal.{u} :=
⟨map₂ Prod fun _ _ _ _ => Equiv.prodCongr⟩
theorem mul_def (α β : Type u) : #α * #β = #(α × β) :=
rfl
#align cardinal.mul_def Cardinal.mul_def
@[simp]
theorem mk_prod (α : Type u) (β : Type v) : #(α × β) = lift.{v, u} #α * lift.{u, v} #β :=
mk_congr (Equiv.ulift.symm.prodCongr Equiv.ulift.symm)
#align cardinal.mk_prod Cardinal.mk_prod
private theorem mul_comm' (a b : Cardinal.{u}) : a * b = b * a :=
inductionOn₂ a b fun α β => mk_congr <| Equiv.prodComm α β
instance instPowCardinal : Pow Cardinal.{u} Cardinal.{u} :=
⟨map₂ (fun α β => β → α) fun _ _ _ _ e₁ e₂ => e₂.arrowCongr e₁⟩
theorem power_def (α β : Type u) : #α ^ #β = #(β → α) :=
rfl
#align cardinal.power_def Cardinal.power_def
theorem mk_arrow (α : Type u) (β : Type v) : #(α → β) = (lift.{u} #β^lift.{v} #α) :=
mk_congr (Equiv.ulift.symm.arrowCongr Equiv.ulift.symm)
#align cardinal.mk_arrow Cardinal.mk_arrow
@[simp]
theorem lift_power (a b : Cardinal.{u}) : lift.{v} (a ^ b) = lift.{v} a ^ lift.{v} b :=
inductionOn₂ a b fun _ _ =>
mk_congr <| Equiv.ulift.trans (Equiv.ulift.arrowCongr Equiv.ulift).symm
#align cardinal.lift_power Cardinal.lift_power
@[simp]
theorem power_zero {a : Cardinal} : a ^ (0 : Cardinal) = 1 :=
inductionOn a fun _ => mk_eq_one _
#align cardinal.power_zero Cardinal.power_zero
@[simp]
theorem power_one {a : Cardinal.{u}} : a ^ (1 : Cardinal) = a :=
inductionOn a fun α => mk_congr (Equiv.funUnique (ULift.{u} (Fin 1)) α)
#align cardinal.power_one Cardinal.power_one
theorem power_add {a b c : Cardinal} : a ^ (b + c) = a ^ b * a ^ c :=
inductionOn₃ a b c fun α β γ => mk_congr <| Equiv.sumArrowEquivProdArrow β γ α
#align cardinal.power_add Cardinal.power_add
instance commSemiring : CommSemiring Cardinal.{u} where
zero := 0
one := 1
add := (· + ·)
mul := (· * ·)
zero_add a := inductionOn a fun α => mk_congr <| Equiv.emptySum (ULift (Fin 0)) α
add_zero a := inductionOn a fun α => mk_congr <| Equiv.sumEmpty α (ULift (Fin 0))
add_assoc a b c := inductionOn₃ a b c fun α β γ => mk_congr <| Equiv.sumAssoc α β γ
add_comm a b := inductionOn₂ a b fun α β => mk_congr <| Equiv.sumComm α β
zero_mul a := inductionOn a fun α => mk_eq_zero _
mul_zero a := inductionOn a fun α => mk_eq_zero _
one_mul a := inductionOn a fun α => mk_congr <| Equiv.uniqueProd α (ULift (Fin 1))
mul_one a := inductionOn a fun α => mk_congr <| Equiv.prodUnique α (ULift (Fin 1))
mul_assoc a b c := inductionOn₃ a b c fun α β γ => mk_congr <| Equiv.prodAssoc α β γ
mul_comm := mul_comm'
left_distrib a b c := inductionOn₃ a b c fun α β γ => mk_congr <| Equiv.prodSumDistrib α β γ
right_distrib a b c := inductionOn₃ a b c fun α β γ => mk_congr <| Equiv.sumProdDistrib α β γ
nsmul := nsmulRec
npow n c := c ^ (n : Cardinal)
npow_zero := @power_zero
npow_succ n c := show c ^ (↑(n + 1) : Cardinal) = c ^ (↑n : Cardinal) * c
by rw [Cardinal.cast_succ, power_add, power_one, mul_comm']
natCast := (fun n => lift.{u} #(Fin n) : ℕ → Cardinal.{u})
natCast_zero := rfl
natCast_succ := Cardinal.cast_succ
@[simp]
theorem one_power {a : Cardinal} : (1 : Cardinal) ^ a = 1 :=
inductionOn a fun _ => mk_eq_one _
#align cardinal.one_power Cardinal.one_power
-- porting note (#10618): simp can prove this
-- @[simp]
theorem mk_bool : #Bool = 2 := by simp
#align cardinal.mk_bool Cardinal.mk_bool
-- porting note (#10618): simp can prove this
-- @[simp]
theorem mk_Prop : #Prop = 2 := by simp
#align cardinal.mk_Prop Cardinal.mk_Prop
@[simp]
theorem zero_power {a : Cardinal} : a ≠ 0 → (0 : Cardinal) ^ a = 0 :=
inductionOn a fun _ heq =>
mk_eq_zero_iff.2 <|
isEmpty_pi.2 <|
let ⟨a⟩ := mk_ne_zero_iff.1 heq
⟨a, inferInstance⟩
#align cardinal.zero_power Cardinal.zero_power
theorem power_ne_zero {a : Cardinal} (b : Cardinal) : a ≠ 0 → a ^ b ≠ 0 :=
inductionOn₂ a b fun _ _ h =>
let ⟨a⟩ := mk_ne_zero_iff.1 h
mk_ne_zero_iff.2 ⟨fun _ => a⟩
#align cardinal.power_ne_zero Cardinal.power_ne_zero
theorem mul_power {a b c : Cardinal} : (a * b) ^ c = a ^ c * b ^ c :=
inductionOn₃ a b c fun α β γ => mk_congr <| Equiv.arrowProdEquivProdArrow α β γ
#align cardinal.mul_power Cardinal.mul_power
| Mathlib/SetTheory/Cardinal/Basic.lean | 592 | 594 | theorem power_mul {a b c : Cardinal} : a ^ (b * c) = (a ^ b) ^ c := by |
rw [mul_comm b c]
exact inductionOn₃ a b c fun α β γ => mk_congr <| Equiv.curry γ β α
|
import Mathlib.MeasureTheory.Integral.Bochner
import Mathlib.MeasureTheory.Measure.GiryMonad
#align_import probability.kernel.basic from "leanprover-community/mathlib"@"fd5edc43dc4f10b85abfe544b88f82cf13c5f844"
open MeasureTheory
open scoped MeasureTheory ENNReal NNReal
namespace ProbabilityTheory
noncomputable def kernel (α β : Type*) [MeasurableSpace α] [MeasurableSpace β] :
AddSubmonoid (α → Measure β) where
carrier := Measurable
zero_mem' := measurable_zero
add_mem' hf hg := Measurable.add hf hg
#align probability_theory.kernel ProbabilityTheory.kernel
-- Porting note: using `FunLike` instead of `CoeFun` to use `DFunLike.coe`
instance {α β : Type*} [MeasurableSpace α] [MeasurableSpace β] :
FunLike (kernel α β) α (Measure β) where
coe := Subtype.val
coe_injective' := Subtype.val_injective
instance kernel.instCovariantAddLE {α β : Type*} [MeasurableSpace α] [MeasurableSpace β] :
CovariantClass (kernel α β) (kernel α β) (· + ·) (· ≤ ·) :=
⟨fun _ _ _ hμ a ↦ add_le_add_left (hμ a) _⟩
noncomputable
instance kernel.instOrderBot {α β : Type*} [MeasurableSpace α] [MeasurableSpace β] :
OrderBot (kernel α β) where
bot := 0
bot_le κ a := by simp only [ZeroMemClass.coe_zero, Pi.zero_apply, Measure.zero_le]
variable {α β ι : Type*} {mα : MeasurableSpace α} {mβ : MeasurableSpace β}
class IsMarkovKernel (κ : kernel α β) : Prop where
isProbabilityMeasure : ∀ a, IsProbabilityMeasure (κ a)
#align probability_theory.is_markov_kernel ProbabilityTheory.IsMarkovKernel
class IsFiniteKernel (κ : kernel α β) : Prop where
exists_univ_le : ∃ C : ℝ≥0∞, C < ∞ ∧ ∀ a, κ a Set.univ ≤ C
#align probability_theory.is_finite_kernel ProbabilityTheory.IsFiniteKernel
noncomputable def IsFiniteKernel.bound (κ : kernel α β) [h : IsFiniteKernel κ] : ℝ≥0∞ :=
h.exists_univ_le.choose
#align probability_theory.is_finite_kernel.bound ProbabilityTheory.IsFiniteKernel.bound
theorem IsFiniteKernel.bound_lt_top (κ : kernel α β) [h : IsFiniteKernel κ] :
IsFiniteKernel.bound κ < ∞ :=
h.exists_univ_le.choose_spec.1
#align probability_theory.is_finite_kernel.bound_lt_top ProbabilityTheory.IsFiniteKernel.bound_lt_top
theorem IsFiniteKernel.bound_ne_top (κ : kernel α β) [IsFiniteKernel κ] :
IsFiniteKernel.bound κ ≠ ∞ :=
(IsFiniteKernel.bound_lt_top κ).ne
#align probability_theory.is_finite_kernel.bound_ne_top ProbabilityTheory.IsFiniteKernel.bound_ne_top
theorem kernel.measure_le_bound (κ : kernel α β) [h : IsFiniteKernel κ] (a : α) (s : Set β) :
κ a s ≤ IsFiniteKernel.bound κ :=
(measure_mono (Set.subset_univ s)).trans (h.exists_univ_le.choose_spec.2 a)
#align probability_theory.kernel.measure_le_bound ProbabilityTheory.kernel.measure_le_bound
instance isFiniteKernel_zero (α β : Type*) {mα : MeasurableSpace α} {mβ : MeasurableSpace β} :
IsFiniteKernel (0 : kernel α β) :=
⟨⟨0, ENNReal.coe_lt_top, fun _ => by
simp only [kernel.zero_apply, Measure.coe_zero, Pi.zero_apply, le_zero_iff]⟩⟩
#align probability_theory.is_finite_kernel_zero ProbabilityTheory.isFiniteKernel_zero
instance IsFiniteKernel.add (κ η : kernel α β) [IsFiniteKernel κ] [IsFiniteKernel η] :
IsFiniteKernel (κ + η) := by
refine ⟨⟨IsFiniteKernel.bound κ + IsFiniteKernel.bound η,
ENNReal.add_lt_top.mpr ⟨IsFiniteKernel.bound_lt_top κ, IsFiniteKernel.bound_lt_top η⟩,
fun a => ?_⟩⟩
exact add_le_add (kernel.measure_le_bound _ _ _) (kernel.measure_le_bound _ _ _)
#align probability_theory.is_finite_kernel.add ProbabilityTheory.IsFiniteKernel.add
lemma isFiniteKernel_of_le {κ ν : kernel α β} [hν : IsFiniteKernel ν] (hκν : κ ≤ ν) :
IsFiniteKernel κ := by
refine ⟨hν.bound, hν.bound_lt_top, fun a ↦ (hκν _ _).trans (kernel.measure_le_bound ν a Set.univ)⟩
variable {κ : kernel α β}
instance IsMarkovKernel.is_probability_measure' [IsMarkovKernel κ] (a : α) :
IsProbabilityMeasure (κ a) :=
IsMarkovKernel.isProbabilityMeasure a
#align probability_theory.is_markov_kernel.is_probability_measure' ProbabilityTheory.IsMarkovKernel.is_probability_measure'
instance IsFiniteKernel.isFiniteMeasure [IsFiniteKernel κ] (a : α) : IsFiniteMeasure (κ a) :=
⟨(kernel.measure_le_bound κ a Set.univ).trans_lt (IsFiniteKernel.bound_lt_top κ)⟩
#align probability_theory.is_finite_kernel.is_finite_measure ProbabilityTheory.IsFiniteKernel.isFiniteMeasure
instance (priority := 100) IsMarkovKernel.isFiniteKernel [IsMarkovKernel κ] :
IsFiniteKernel κ :=
⟨⟨1, ENNReal.one_lt_top, fun _ => prob_le_one⟩⟩
#align probability_theory.is_markov_kernel.is_finite_kernel ProbabilityTheory.IsMarkovKernel.isFiniteKernel
namespace kernel
@[ext]
theorem ext {η : kernel α β} (h : ∀ a, κ a = η a) : κ = η := DFunLike.ext _ _ h
#align probability_theory.kernel.ext ProbabilityTheory.kernel.ext
theorem ext_iff {η : kernel α β} : κ = η ↔ ∀ a, κ a = η a := DFunLike.ext_iff
#align probability_theory.kernel.ext_iff ProbabilityTheory.kernel.ext_iff
theorem ext_iff' {η : kernel α β} :
κ = η ↔ ∀ a s, MeasurableSet s → κ a s = η a s := by
simp_rw [ext_iff, Measure.ext_iff]
#align probability_theory.kernel.ext_iff' ProbabilityTheory.kernel.ext_iff'
theorem ext_fun {η : kernel α β} (h : ∀ a f, Measurable f → ∫⁻ b, f b ∂κ a = ∫⁻ b, f b ∂η a) :
κ = η := by
ext a s hs
specialize h a (s.indicator fun _ => 1) (Measurable.indicator measurable_const hs)
simp_rw [lintegral_indicator_const hs, one_mul] at h
rw [h]
#align probability_theory.kernel.ext_fun ProbabilityTheory.kernel.ext_fun
theorem ext_fun_iff {η : kernel α β} :
κ = η ↔ ∀ a f, Measurable f → ∫⁻ b, f b ∂κ a = ∫⁻ b, f b ∂η a :=
⟨fun h a f _ => by rw [h], ext_fun⟩
#align probability_theory.kernel.ext_fun_iff ProbabilityTheory.kernel.ext_fun_iff
protected theorem measurable (κ : kernel α β) : Measurable κ :=
κ.prop
#align probability_theory.kernel.measurable ProbabilityTheory.kernel.measurable
protected theorem measurable_coe (κ : kernel α β) {s : Set β} (hs : MeasurableSet s) :
Measurable fun a => κ a s :=
(Measure.measurable_coe hs).comp (kernel.measurable κ)
#align probability_theory.kernel.measurable_coe ProbabilityTheory.kernel.measurable_coe
lemma IsFiniteKernel.integrable (μ : Measure α) [IsFiniteMeasure μ]
(κ : kernel α β) [IsFiniteKernel κ] {s : Set β} (hs : MeasurableSet s) :
Integrable (fun x => (κ x s).toReal) μ := by
refine Integrable.mono' (integrable_const (IsFiniteKernel.bound κ).toReal)
((kernel.measurable_coe κ hs).ennreal_toReal.aestronglyMeasurable)
(ae_of_all μ fun x => ?_)
rw [Real.norm_eq_abs, abs_of_nonneg ENNReal.toReal_nonneg,
ENNReal.toReal_le_toReal (measure_ne_top _ _) (IsFiniteKernel.bound_ne_top _)]
exact kernel.measure_le_bound _ _ _
lemma IsMarkovKernel.integrable (μ : Measure α) [IsFiniteMeasure μ]
(κ : kernel α β) [IsMarkovKernel κ] {s : Set β} (hs : MeasurableSet s) :
Integrable (fun x => (κ x s).toReal) μ :=
IsFiniteKernel.integrable μ κ hs
section SFinite
class _root_.ProbabilityTheory.IsSFiniteKernel (κ : kernel α β) : Prop where
tsum_finite : ∃ κs : ℕ → kernel α β, (∀ n, IsFiniteKernel (κs n)) ∧ κ = kernel.sum κs
#align probability_theory.is_s_finite_kernel ProbabilityTheory.IsSFiniteKernel
instance (priority := 100) IsFiniteKernel.isSFiniteKernel [h : IsFiniteKernel κ] :
IsSFiniteKernel κ :=
⟨⟨fun n => if n = 0 then κ else 0, fun n => by
simp only; split_ifs
· exact h
· infer_instance, by
ext a s hs
rw [kernel.sum_apply' _ _ hs]
have : (fun i => ((ite (i = 0) κ 0) a) s) = fun i => ite (i = 0) (κ a s) 0 := by
ext1 i; split_ifs <;> rfl
rw [this, tsum_ite_eq]⟩⟩
#align probability_theory.kernel.is_finite_kernel.is_s_finite_kernel ProbabilityTheory.kernel.IsFiniteKernel.isSFiniteKernel
noncomputable def seq (κ : kernel α β) [h : IsSFiniteKernel κ] : ℕ → kernel α β :=
h.tsum_finite.choose
#align probability_theory.kernel.seq ProbabilityTheory.kernel.seq
theorem kernel_sum_seq (κ : kernel α β) [h : IsSFiniteKernel κ] : kernel.sum (seq κ) = κ :=
h.tsum_finite.choose_spec.2.symm
#align probability_theory.kernel.kernel_sum_seq ProbabilityTheory.kernel.kernel_sum_seq
theorem measure_sum_seq (κ : kernel α β) [h : IsSFiniteKernel κ] (a : α) :
(Measure.sum fun n => seq κ n a) = κ a := by rw [← kernel.sum_apply, kernel_sum_seq κ]
#align probability_theory.kernel.measure_sum_seq ProbabilityTheory.kernel.measure_sum_seq
instance isFiniteKernel_seq (κ : kernel α β) [h : IsSFiniteKernel κ] (n : ℕ) :
IsFiniteKernel (kernel.seq κ n) :=
h.tsum_finite.choose_spec.1 n
#align probability_theory.kernel.is_finite_kernel_seq ProbabilityTheory.kernel.isFiniteKernel_seq
instance IsSFiniteKernel.sFinite [IsSFiniteKernel κ] (a : α) : SFinite (κ a) :=
⟨⟨fun n ↦ seq κ n a, inferInstance, (measure_sum_seq κ a).symm⟩⟩
instance IsSFiniteKernel.add (κ η : kernel α β) [IsSFiniteKernel κ] [IsSFiniteKernel η] :
IsSFiniteKernel (κ + η) := by
refine ⟨⟨fun n => seq κ n + seq η n, fun n => inferInstance, ?_⟩⟩
rw [sum_add, kernel_sum_seq κ, kernel_sum_seq η]
#align probability_theory.kernel.is_s_finite_kernel.add ProbabilityTheory.kernel.IsSFiniteKernel.add
theorem IsSFiniteKernel.finset_sum {κs : ι → kernel α β} (I : Finset ι)
(h : ∀ i ∈ I, IsSFiniteKernel (κs i)) : IsSFiniteKernel (∑ i ∈ I, κs i) := by
classical
induction' I using Finset.induction with i I hi_nmem_I h_ind h
· rw [Finset.sum_empty]; infer_instance
· rw [Finset.sum_insert hi_nmem_I]
haveI : IsSFiniteKernel (κs i) := h i (Finset.mem_insert_self _ _)
have : IsSFiniteKernel (∑ x ∈ I, κs x) :=
h_ind fun i hiI => h i (Finset.mem_insert_of_mem hiI)
exact IsSFiniteKernel.add _ _
#align probability_theory.kernel.is_s_finite_kernel.finset_sum ProbabilityTheory.kernel.IsSFiniteKernel.finset_sum
| Mathlib/Probability/Kernel/Basic.lean | 350 | 361 | theorem isSFiniteKernel_sum_of_denumerable [Denumerable ι] {κs : ι → kernel α β}
(hκs : ∀ n, IsSFiniteKernel (κs n)) : IsSFiniteKernel (kernel.sum κs) := by |
let e : ℕ ≃ ι × ℕ := (Denumerable.eqv (ι × ℕ)).symm
refine ⟨⟨fun n => seq (κs (e n).1) (e n).2, inferInstance, ?_⟩⟩
have hκ_eq : kernel.sum κs = kernel.sum fun n => kernel.sum (seq (κs n)) := by
simp_rw [kernel_sum_seq]
ext a s hs
rw [hκ_eq]
simp_rw [kernel.sum_apply' _ _ hs]
change (∑' i, ∑' m, seq (κs i) m a s) = ∑' n, (fun im : ι × ℕ => seq (κs im.fst) im.snd a s) (e n)
rw [e.tsum_eq (fun im : ι × ℕ => seq (κs im.fst) im.snd a s),
tsum_prod' ENNReal.summable fun _ => ENNReal.summable]
|
import Mathlib.Mathport.Rename
import Mathlib.Init.Algebra.Classes
import Mathlib.Init.Data.Ordering.Basic
import Mathlib.Tactic.SplitIfs
import Mathlib.Tactic.TypeStar
import Batteries.Classes.Order
#align_import init.algebra.order from "leanprover-community/lean"@"c2bcdbcbe741ed37c361a30d38e179182b989f76"
universe u
variable {α : Type u}
section PartialOrder
class PartialOrder (α : Type u) extends Preorder α where
le_antisymm : ∀ a b : α, a ≤ b → b ≤ a → a = b
#align partial_order PartialOrder
variable [PartialOrder α]
theorem le_antisymm : ∀ {a b : α}, a ≤ b → b ≤ a → a = b :=
PartialOrder.le_antisymm _ _
#align le_antisymm le_antisymm
alias eq_of_le_of_le := le_antisymm
theorem le_antisymm_iff {a b : α} : a = b ↔ a ≤ b ∧ b ≤ a :=
⟨fun e => ⟨le_of_eq e, le_of_eq e.symm⟩, fun ⟨h1, h2⟩ => le_antisymm h1 h2⟩
#align le_antisymm_iff le_antisymm_iff
theorem lt_of_le_of_ne {a b : α} : a ≤ b → a ≠ b → a < b := fun h₁ h₂ =>
lt_of_le_not_le h₁ <| mt (le_antisymm h₁) h₂
#align lt_of_le_of_ne lt_of_le_of_ne
def decidableEqOfDecidableLE [@DecidableRel α (· ≤ ·)] : DecidableEq α
| a, b =>
if hab : a ≤ b then
if hba : b ≤ a then isTrue (le_antisymm hab hba) else isFalse fun heq => hba (heq ▸ le_refl _)
else isFalse fun heq => hab (heq ▸ le_refl _)
#align decidable_eq_of_decidable_le decidableEqOfDecidableLE
section LinearOrder
def maxDefault {α : Type u} [LE α] [DecidableRel ((· ≤ ·) : α → α → Prop)] (a b : α) :=
if a ≤ b then b else a
#align max_default maxDefault
def minDefault {α : Type u} [LE α] [DecidableRel ((· ≤ ·) : α → α → Prop)] (a b : α) :=
if a ≤ b then a else b
macro "compareOfLessAndEq_rfl" : tactic =>
`(tactic| (intros a b; first | rfl |
(simp only [compare, compareOfLessAndEq]; split_ifs <;> rfl) |
(induction a <;> induction b <;> simp (config := {decide := true}) only [])))
class LinearOrder (α : Type u) extends PartialOrder α, Min α, Max α, Ord α :=
le_total (a b : α) : a ≤ b ∨ b ≤ a
decidableLE : DecidableRel (· ≤ · : α → α → Prop)
decidableEq : DecidableEq α := @decidableEqOfDecidableLE _ _ decidableLE
decidableLT : DecidableRel (· < · : α → α → Prop) :=
@decidableLTOfDecidableLE _ _ decidableLE
min := fun a b => if a ≤ b then a else b
max := fun a b => if a ≤ b then b else a
min_def : ∀ a b, min a b = if a ≤ b then a else b := by intros; rfl
max_def : ∀ a b, max a b = if a ≤ b then b else a := by intros; rfl
compare a b := compareOfLessAndEq a b
compare_eq_compareOfLessAndEq : ∀ a b, compare a b = compareOfLessAndEq a b := by
compareOfLessAndEq_rfl
#align linear_order LinearOrder
variable [LinearOrder α]
attribute [local instance] LinearOrder.decidableLE
theorem le_total : ∀ a b : α, a ≤ b ∨ b ≤ a :=
LinearOrder.le_total
#align le_total le_total
theorem le_of_not_ge {a b : α} : ¬a ≥ b → a ≤ b :=
Or.resolve_left (le_total b a)
#align le_of_not_ge le_of_not_ge
theorem le_of_not_le {a b : α} : ¬a ≤ b → b ≤ a :=
Or.resolve_left (le_total a b)
#align le_of_not_le le_of_not_le
theorem not_lt_of_gt {a b : α} (h : a > b) : ¬a < b :=
lt_asymm h
#align not_lt_of_gt not_lt_of_gt
theorem lt_trichotomy (a b : α) : a < b ∨ a = b ∨ b < a :=
Or.elim (le_total a b)
(fun h : a ≤ b =>
Or.elim (Decidable.lt_or_eq_of_le h) (fun h : a < b => Or.inl h) fun h : a = b =>
Or.inr (Or.inl h))
fun h : b ≤ a =>
Or.elim (Decidable.lt_or_eq_of_le h) (fun h : b < a => Or.inr (Or.inr h)) fun h : b = a =>
Or.inr (Or.inl h.symm)
#align lt_trichotomy lt_trichotomy
theorem le_of_not_lt {a b : α} (h : ¬b < a) : a ≤ b :=
match lt_trichotomy a b with
| Or.inl hlt => le_of_lt hlt
| Or.inr (Or.inl HEq) => HEq ▸ le_refl a
| Or.inr (Or.inr hgt) => absurd hgt h
#align le_of_not_lt le_of_not_lt
theorem le_of_not_gt {a b : α} : ¬a > b → a ≤ b :=
le_of_not_lt
#align le_of_not_gt le_of_not_gt
theorem lt_of_not_ge {a b : α} (h : ¬a ≥ b) : a < b :=
lt_of_le_not_le ((le_total _ _).resolve_right h) h
#align lt_of_not_ge lt_of_not_ge
theorem lt_or_le (a b : α) : a < b ∨ b ≤ a :=
if hba : b ≤ a then Or.inr hba else Or.inl <| lt_of_not_ge hba
#align lt_or_le lt_or_le
theorem le_or_lt (a b : α) : a ≤ b ∨ b < a :=
(lt_or_le b a).symm
#align le_or_lt le_or_lt
theorem lt_or_ge : ∀ a b : α, a < b ∨ a ≥ b :=
lt_or_le
#align lt_or_ge lt_or_ge
theorem le_or_gt : ∀ a b : α, a ≤ b ∨ a > b :=
le_or_lt
#align le_or_gt le_or_gt
theorem lt_or_gt_of_ne {a b : α} (h : a ≠ b) : a < b ∨ a > b :=
match lt_trichotomy a b with
| Or.inl hlt => Or.inl hlt
| Or.inr (Or.inl HEq) => absurd HEq h
| Or.inr (Or.inr hgt) => Or.inr hgt
#align lt_or_gt_of_ne lt_or_gt_of_ne
theorem ne_iff_lt_or_gt {a b : α} : a ≠ b ↔ a < b ∨ a > b :=
⟨lt_or_gt_of_ne, fun o => Or.elim o ne_of_lt ne_of_gt⟩
#align ne_iff_lt_or_gt ne_iff_lt_or_gt
theorem lt_iff_not_ge (x y : α) : x < y ↔ ¬x ≥ y :=
⟨not_le_of_gt, lt_of_not_ge⟩
#align lt_iff_not_ge lt_iff_not_ge
@[simp]
theorem not_lt {a b : α} : ¬a < b ↔ b ≤ a :=
⟨le_of_not_gt, not_lt_of_ge⟩
#align not_lt not_lt
@[simp]
theorem not_le {a b : α} : ¬a ≤ b ↔ b < a :=
(lt_iff_not_ge _ _).symm
#align not_le not_le
instance (priority := 900) (a b : α) : Decidable (a < b) :=
LinearOrder.decidableLT a b
instance (priority := 900) (a b : α) : Decidable (a ≤ b) :=
LinearOrder.decidableLE a b
instance (priority := 900) (a b : α) : Decidable (a = b) :=
LinearOrder.decidableEq a b
theorem eq_or_lt_of_not_lt {a b : α} (h : ¬a < b) : a = b ∨ b < a :=
if h₁ : a = b then Or.inl h₁ else Or.inr (lt_of_not_ge fun hge => h (lt_of_le_of_ne hge h₁))
#align eq_or_lt_of_not_lt eq_or_lt_of_not_lt
instance : IsTotalPreorder α (· ≤ ·) where
trans := @le_trans _ _
total := le_total
-- TODO(Leo): decide whether we should keep this instance or not
instance isStrictWeakOrder_of_linearOrder : IsStrictWeakOrder α (· < ·) :=
have : IsTotalPreorder α (· ≤ ·) := by infer_instance -- Porting note: added
isStrictWeakOrder_of_isTotalPreorder lt_iff_not_ge
#align is_strict_weak_order_of_linear_order isStrictWeakOrder_of_linearOrder
-- TODO(Leo): decide whether we should keep this instance or not
instance isStrictTotalOrder_of_linearOrder : IsStrictTotalOrder α (· < ·) where
trichotomous := lt_trichotomy
#align is_strict_total_order_of_linear_order isStrictTotalOrder_of_linearOrder
def ltByCases (x y : α) {P : Sort*} (h₁ : x < y → P) (h₂ : x = y → P) (h₃ : y < x → P) : P :=
if h : x < y then h₁ h
else if h' : y < x then h₃ h' else h₂ (le_antisymm (le_of_not_gt h') (le_of_not_gt h))
#align lt_by_cases ltByCases
theorem le_imp_le_of_lt_imp_lt {β} [Preorder α] [LinearOrder β] {a b : α} {c d : β}
(H : d < c → b < a) (h : a ≤ b) : c ≤ d :=
le_of_not_lt fun h' => not_le_of_gt (H h') h
#align le_imp_le_of_lt_imp_lt le_imp_le_of_lt_imp_lt
-- Porting note: new
section Ord
theorem compare_lt_iff_lt {a b : α} : (compare a b = .lt) ↔ a < b := by
rw [LinearOrder.compare_eq_compareOfLessAndEq, compareOfLessAndEq]
split_ifs <;> simp only [*, lt_irrefl]
theorem compare_gt_iff_gt {a b : α} : (compare a b = .gt) ↔ a > b := by
rw [LinearOrder.compare_eq_compareOfLessAndEq, compareOfLessAndEq]
split_ifs <;> simp only [*, lt_irrefl, not_lt_of_gt]
case _ h₁ h₂ =>
have h : b < a := lt_trichotomy a b |>.resolve_left h₁ |>.resolve_left h₂
exact true_iff_iff.2 h
theorem compare_eq_iff_eq {a b : α} : (compare a b = .eq) ↔ a = b := by
rw [LinearOrder.compare_eq_compareOfLessAndEq, compareOfLessAndEq]
split_ifs <;> try simp only
case _ h => exact false_iff_iff.2 <| ne_iff_lt_or_gt.2 <| .inl h
case _ _ h => exact true_iff_iff.2 h
case _ _ h => exact false_iff_iff.2 h
| Mathlib/Init/Order/Defs.lean | 439 | 443 | theorem compare_le_iff_le {a b : α} : (compare a b ≠ .gt) ↔ a ≤ b := by |
cases h : compare a b <;> simp
· exact le_of_lt <| compare_lt_iff_lt.1 h
· exact le_of_eq <| compare_eq_iff_eq.1 h
· exact compare_gt_iff_gt.1 h
|
import Mathlib.Analysis.SpecialFunctions.Pow.Asymptotics
#align_import analysis.special_functions.pow.continuity from "leanprover-community/mathlib"@"0b9eaaa7686280fad8cce467f5c3c57ee6ce77f8"
noncomputable section
open scoped Classical
open Real Topology NNReal ENNReal Filter ComplexConjugate
open Filter Finset Set
section CpowLimits
open Complex
variable {α : Type*}
theorem zero_cpow_eq_nhds {b : ℂ} (hb : b ≠ 0) : (fun x : ℂ => (0 : ℂ) ^ x) =ᶠ[𝓝 b] 0 := by
suffices ∀ᶠ x : ℂ in 𝓝 b, x ≠ 0 from
this.mono fun x hx ↦ by
dsimp only
rw [zero_cpow hx, Pi.zero_apply]
exact IsOpen.eventually_mem isOpen_ne hb
#align zero_cpow_eq_nhds zero_cpow_eq_nhds
theorem cpow_eq_nhds {a b : ℂ} (ha : a ≠ 0) :
(fun x => x ^ b) =ᶠ[𝓝 a] fun x => exp (log x * b) := by
suffices ∀ᶠ x : ℂ in 𝓝 a, x ≠ 0 from
this.mono fun x hx ↦ by
dsimp only
rw [cpow_def_of_ne_zero hx]
exact IsOpen.eventually_mem isOpen_ne ha
#align cpow_eq_nhds cpow_eq_nhds
theorem cpow_eq_nhds' {p : ℂ × ℂ} (hp_fst : p.fst ≠ 0) :
(fun x => x.1 ^ x.2) =ᶠ[𝓝 p] fun x => exp (log x.1 * x.2) := by
suffices ∀ᶠ x : ℂ × ℂ in 𝓝 p, x.1 ≠ 0 from
this.mono fun x hx ↦ by
dsimp only
rw [cpow_def_of_ne_zero hx]
refine IsOpen.eventually_mem ?_ hp_fst
change IsOpen { x : ℂ × ℂ | x.1 = 0 }ᶜ
rw [isOpen_compl_iff]
exact isClosed_eq continuous_fst continuous_const
#align cpow_eq_nhds' cpow_eq_nhds'
-- Continuity of `fun x => a ^ x`: union of these two lemmas is optimal.
| Mathlib/Analysis/SpecialFunctions/Pow/Continuity.lean | 66 | 71 | theorem continuousAt_const_cpow {a b : ℂ} (ha : a ≠ 0) : ContinuousAt (fun x : ℂ => a ^ x) b := by |
have cpow_eq : (fun x : ℂ => a ^ x) = fun x => exp (log a * x) := by
ext1 b
rw [cpow_def_of_ne_zero ha]
rw [cpow_eq]
exact continuous_exp.continuousAt.comp (ContinuousAt.mul continuousAt_const continuousAt_id)
|
import Mathlib.Analysis.SpecialFunctions.Trigonometric.Basic
import Mathlib.Analysis.Normed.Group.AddCircle
import Mathlib.Algebra.CharZero.Quotient
import Mathlib.Topology.Instances.Sign
#align_import analysis.special_functions.trigonometric.angle from "leanprover-community/mathlib"@"213b0cff7bc5ab6696ee07cceec80829ce42efec"
open Real
noncomputable section
namespace Real
-- Porting note: can't derive `NormedAddCommGroup, Inhabited`
def Angle : Type :=
AddCircle (2 * π)
#align real.angle Real.Angle
namespace Angle
-- Porting note (#10754): added due to missing instances due to no deriving
instance : NormedAddCommGroup Angle :=
inferInstanceAs (NormedAddCommGroup (AddCircle (2 * π)))
-- Porting note (#10754): added due to missing instances due to no deriving
instance : Inhabited Angle :=
inferInstanceAs (Inhabited (AddCircle (2 * π)))
-- Porting note (#10754): added due to missing instances due to no deriving
-- also, without this, a plain `QuotientAddGroup.mk`
-- causes coerced terms to be of type `ℝ ⧸ AddSubgroup.zmultiples (2 * π)`
@[coe]
protected def coe (r : ℝ) : Angle := QuotientAddGroup.mk r
instance : Coe ℝ Angle := ⟨Angle.coe⟩
instance : CircularOrder Real.Angle :=
QuotientAddGroup.circularOrder (hp' := ⟨by norm_num [pi_pos]⟩)
@[continuity]
theorem continuous_coe : Continuous ((↑) : ℝ → Angle) :=
continuous_quotient_mk'
#align real.angle.continuous_coe Real.Angle.continuous_coe
def coeHom : ℝ →+ Angle :=
QuotientAddGroup.mk' _
#align real.angle.coe_hom Real.Angle.coeHom
@[simp]
theorem coe_coeHom : (coeHom : ℝ → Angle) = ((↑) : ℝ → Angle) :=
rfl
#align real.angle.coe_coe_hom Real.Angle.coe_coeHom
@[elab_as_elim]
protected theorem induction_on {p : Angle → Prop} (θ : Angle) (h : ∀ x : ℝ, p x) : p θ :=
Quotient.inductionOn' θ h
#align real.angle.induction_on Real.Angle.induction_on
@[simp]
theorem coe_zero : ↑(0 : ℝ) = (0 : Angle) :=
rfl
#align real.angle.coe_zero Real.Angle.coe_zero
@[simp]
theorem coe_add (x y : ℝ) : ↑(x + y : ℝ) = (↑x + ↑y : Angle) :=
rfl
#align real.angle.coe_add Real.Angle.coe_add
@[simp]
theorem coe_neg (x : ℝ) : ↑(-x : ℝ) = -(↑x : Angle) :=
rfl
#align real.angle.coe_neg Real.Angle.coe_neg
@[simp]
theorem coe_sub (x y : ℝ) : ↑(x - y : ℝ) = (↑x - ↑y : Angle) :=
rfl
#align real.angle.coe_sub Real.Angle.coe_sub
theorem coe_nsmul (n : ℕ) (x : ℝ) : ↑(n • x : ℝ) = n • (↑x : Angle) :=
rfl
#align real.angle.coe_nsmul Real.Angle.coe_nsmul
theorem coe_zsmul (z : ℤ) (x : ℝ) : ↑(z • x : ℝ) = z • (↑x : Angle) :=
rfl
#align real.angle.coe_zsmul Real.Angle.coe_zsmul
@[simp, norm_cast]
theorem natCast_mul_eq_nsmul (x : ℝ) (n : ℕ) : ↑((n : ℝ) * x) = n • (↑x : Angle) := by
simpa only [nsmul_eq_mul] using coeHom.map_nsmul x n
#align real.angle.coe_nat_mul_eq_nsmul Real.Angle.natCast_mul_eq_nsmul
@[simp, norm_cast]
theorem intCast_mul_eq_zsmul (x : ℝ) (n : ℤ) : ↑((n : ℝ) * x : ℝ) = n • (↑x : Angle) := by
simpa only [zsmul_eq_mul] using coeHom.map_zsmul x n
#align real.angle.coe_int_mul_eq_zsmul Real.Angle.intCast_mul_eq_zsmul
@[deprecated (since := "2024-05-25")] alias coe_nat_mul_eq_nsmul := natCast_mul_eq_nsmul
@[deprecated (since := "2024-05-25")] alias coe_int_mul_eq_zsmul := intCast_mul_eq_zsmul
theorem angle_eq_iff_two_pi_dvd_sub {ψ θ : ℝ} : (θ : Angle) = ψ ↔ ∃ k : ℤ, θ - ψ = 2 * π * k := by
simp only [QuotientAddGroup.eq, AddSubgroup.zmultiples_eq_closure,
AddSubgroup.mem_closure_singleton, zsmul_eq_mul', (sub_eq_neg_add _ _).symm, eq_comm]
-- Porting note: added `rw`, `simp [Angle.coe, QuotientAddGroup.eq]` doesn't fire otherwise
rw [Angle.coe, Angle.coe, QuotientAddGroup.eq]
simp only [AddSubgroup.zmultiples_eq_closure,
AddSubgroup.mem_closure_singleton, zsmul_eq_mul', (sub_eq_neg_add _ _).symm, eq_comm]
#align real.angle.angle_eq_iff_two_pi_dvd_sub Real.Angle.angle_eq_iff_two_pi_dvd_sub
@[simp]
theorem coe_two_pi : ↑(2 * π : ℝ) = (0 : Angle) :=
angle_eq_iff_two_pi_dvd_sub.2 ⟨1, by rw [sub_zero, Int.cast_one, mul_one]⟩
#align real.angle.coe_two_pi Real.Angle.coe_two_pi
@[simp]
theorem neg_coe_pi : -(π : Angle) = π := by
rw [← coe_neg, angle_eq_iff_two_pi_dvd_sub]
use -1
simp [two_mul, sub_eq_add_neg]
#align real.angle.neg_coe_pi Real.Angle.neg_coe_pi
@[simp]
theorem two_nsmul_coe_div_two (θ : ℝ) : (2 : ℕ) • (↑(θ / 2) : Angle) = θ := by
rw [← coe_nsmul, two_nsmul, add_halves]
#align real.angle.two_nsmul_coe_div_two Real.Angle.two_nsmul_coe_div_two
@[simp]
theorem two_zsmul_coe_div_two (θ : ℝ) : (2 : ℤ) • (↑(θ / 2) : Angle) = θ := by
rw [← coe_zsmul, two_zsmul, add_halves]
#align real.angle.two_zsmul_coe_div_two Real.Angle.two_zsmul_coe_div_two
-- Porting note (#10618): @[simp] can prove it
theorem two_nsmul_neg_pi_div_two : (2 : ℕ) • (↑(-π / 2) : Angle) = π := by
rw [two_nsmul_coe_div_two, coe_neg, neg_coe_pi]
#align real.angle.two_nsmul_neg_pi_div_two Real.Angle.two_nsmul_neg_pi_div_two
-- Porting note (#10618): @[simp] can prove it
theorem two_zsmul_neg_pi_div_two : (2 : ℤ) • (↑(-π / 2) : Angle) = π := by
rw [two_zsmul, ← two_nsmul, two_nsmul_neg_pi_div_two]
#align real.angle.two_zsmul_neg_pi_div_two Real.Angle.two_zsmul_neg_pi_div_two
theorem sub_coe_pi_eq_add_coe_pi (θ : Angle) : θ - π = θ + π := by
rw [sub_eq_add_neg, neg_coe_pi]
#align real.angle.sub_coe_pi_eq_add_coe_pi Real.Angle.sub_coe_pi_eq_add_coe_pi
@[simp]
theorem two_nsmul_coe_pi : (2 : ℕ) • (π : Angle) = 0 := by simp [← natCast_mul_eq_nsmul]
#align real.angle.two_nsmul_coe_pi Real.Angle.two_nsmul_coe_pi
@[simp]
theorem two_zsmul_coe_pi : (2 : ℤ) • (π : Angle) = 0 := by simp [← intCast_mul_eq_zsmul]
#align real.angle.two_zsmul_coe_pi Real.Angle.two_zsmul_coe_pi
@[simp]
theorem coe_pi_add_coe_pi : (π : Real.Angle) + π = 0 := by rw [← two_nsmul, two_nsmul_coe_pi]
#align real.angle.coe_pi_add_coe_pi Real.Angle.coe_pi_add_coe_pi
theorem zsmul_eq_iff {ψ θ : Angle} {z : ℤ} (hz : z ≠ 0) :
z • ψ = z • θ ↔ ∃ k : Fin z.natAbs, ψ = θ + (k : ℕ) • (2 * π / z : ℝ) :=
QuotientAddGroup.zmultiples_zsmul_eq_zsmul_iff hz
#align real.angle.zsmul_eq_iff Real.Angle.zsmul_eq_iff
theorem nsmul_eq_iff {ψ θ : Angle} {n : ℕ} (hz : n ≠ 0) :
n • ψ = n • θ ↔ ∃ k : Fin n, ψ = θ + (k : ℕ) • (2 * π / n : ℝ) :=
QuotientAddGroup.zmultiples_nsmul_eq_nsmul_iff hz
#align real.angle.nsmul_eq_iff Real.Angle.nsmul_eq_iff
theorem two_zsmul_eq_iff {ψ θ : Angle} : (2 : ℤ) • ψ = (2 : ℤ) • θ ↔ ψ = θ ∨ ψ = θ + ↑π := by
-- Porting note: no `Int.natAbs_bit0` anymore
have : Int.natAbs 2 = 2 := rfl
rw [zsmul_eq_iff two_ne_zero, this, Fin.exists_fin_two, Fin.val_zero,
Fin.val_one, zero_smul, add_zero, one_smul, Int.cast_two,
mul_div_cancel_left₀ (_ : ℝ) two_ne_zero]
#align real.angle.two_zsmul_eq_iff Real.Angle.two_zsmul_eq_iff
theorem two_nsmul_eq_iff {ψ θ : Angle} : (2 : ℕ) • ψ = (2 : ℕ) • θ ↔ ψ = θ ∨ ψ = θ + ↑π := by
simp_rw [← natCast_zsmul, Nat.cast_ofNat, two_zsmul_eq_iff]
#align real.angle.two_nsmul_eq_iff Real.Angle.two_nsmul_eq_iff
theorem two_nsmul_eq_zero_iff {θ : Angle} : (2 : ℕ) • θ = 0 ↔ θ = 0 ∨ θ = π := by
convert two_nsmul_eq_iff <;> simp
#align real.angle.two_nsmul_eq_zero_iff Real.Angle.two_nsmul_eq_zero_iff
theorem two_nsmul_ne_zero_iff {θ : Angle} : (2 : ℕ) • θ ≠ 0 ↔ θ ≠ 0 ∧ θ ≠ π := by
rw [← not_or, ← two_nsmul_eq_zero_iff]
#align real.angle.two_nsmul_ne_zero_iff Real.Angle.two_nsmul_ne_zero_iff
theorem two_zsmul_eq_zero_iff {θ : Angle} : (2 : ℤ) • θ = 0 ↔ θ = 0 ∨ θ = π := by
simp_rw [two_zsmul, ← two_nsmul, two_nsmul_eq_zero_iff]
#align real.angle.two_zsmul_eq_zero_iff Real.Angle.two_zsmul_eq_zero_iff
theorem two_zsmul_ne_zero_iff {θ : Angle} : (2 : ℤ) • θ ≠ 0 ↔ θ ≠ 0 ∧ θ ≠ π := by
rw [← not_or, ← two_zsmul_eq_zero_iff]
#align real.angle.two_zsmul_ne_zero_iff Real.Angle.two_zsmul_ne_zero_iff
theorem eq_neg_self_iff {θ : Angle} : θ = -θ ↔ θ = 0 ∨ θ = π := by
rw [← add_eq_zero_iff_eq_neg, ← two_nsmul, two_nsmul_eq_zero_iff]
#align real.angle.eq_neg_self_iff Real.Angle.eq_neg_self_iff
theorem ne_neg_self_iff {θ : Angle} : θ ≠ -θ ↔ θ ≠ 0 ∧ θ ≠ π := by
rw [← not_or, ← eq_neg_self_iff.not]
#align real.angle.ne_neg_self_iff Real.Angle.ne_neg_self_iff
theorem neg_eq_self_iff {θ : Angle} : -θ = θ ↔ θ = 0 ∨ θ = π := by rw [eq_comm, eq_neg_self_iff]
#align real.angle.neg_eq_self_iff Real.Angle.neg_eq_self_iff
theorem neg_ne_self_iff {θ : Angle} : -θ ≠ θ ↔ θ ≠ 0 ∧ θ ≠ π := by
rw [← not_or, ← neg_eq_self_iff.not]
#align real.angle.neg_ne_self_iff Real.Angle.neg_ne_self_iff
theorem two_nsmul_eq_pi_iff {θ : Angle} : (2 : ℕ) • θ = π ↔ θ = (π / 2 : ℝ) ∨ θ = (-π / 2 : ℝ) := by
have h : (π : Angle) = ((2 : ℕ) • (π / 2 : ℝ) :) := by rw [two_nsmul, add_halves]
nth_rw 1 [h]
rw [coe_nsmul, two_nsmul_eq_iff]
-- Porting note: `congr` didn't simplify the goal of iff of `Or`s
convert Iff.rfl
rw [add_comm, ← coe_add, ← sub_eq_zero, ← coe_sub, neg_div, ← neg_sub, sub_neg_eq_add, add_assoc,
add_halves, ← two_mul, coe_neg, coe_two_pi, neg_zero]
#align real.angle.two_nsmul_eq_pi_iff Real.Angle.two_nsmul_eq_pi_iff
theorem two_zsmul_eq_pi_iff {θ : Angle} : (2 : ℤ) • θ = π ↔ θ = (π / 2 : ℝ) ∨ θ = (-π / 2 : ℝ) := by
rw [two_zsmul, ← two_nsmul, two_nsmul_eq_pi_iff]
#align real.angle.two_zsmul_eq_pi_iff Real.Angle.two_zsmul_eq_pi_iff
theorem cos_eq_iff_coe_eq_or_eq_neg {θ ψ : ℝ} :
cos θ = cos ψ ↔ (θ : Angle) = ψ ∨ (θ : Angle) = -ψ := by
constructor
· intro Hcos
rw [← sub_eq_zero, cos_sub_cos, mul_eq_zero, mul_eq_zero, neg_eq_zero,
eq_false (two_ne_zero' ℝ), false_or_iff, sin_eq_zero_iff, sin_eq_zero_iff] at Hcos
rcases Hcos with (⟨n, hn⟩ | ⟨n, hn⟩)
· right
rw [eq_div_iff_mul_eq (two_ne_zero' ℝ), ← sub_eq_iff_eq_add] at hn
rw [← hn, coe_sub, eq_neg_iff_add_eq_zero, sub_add_cancel, mul_assoc, intCast_mul_eq_zsmul,
mul_comm, coe_two_pi, zsmul_zero]
· left
rw [eq_div_iff_mul_eq (two_ne_zero' ℝ), eq_sub_iff_add_eq] at hn
rw [← hn, coe_add, mul_assoc, intCast_mul_eq_zsmul, mul_comm, coe_two_pi, zsmul_zero,
zero_add]
· rw [angle_eq_iff_two_pi_dvd_sub, ← coe_neg, angle_eq_iff_two_pi_dvd_sub]
rintro (⟨k, H⟩ | ⟨k, H⟩)
· rw [← sub_eq_zero, cos_sub_cos, H, mul_assoc 2 π k, mul_div_cancel_left₀ _ (two_ne_zero' ℝ),
mul_comm π _, sin_int_mul_pi, mul_zero]
rw [← sub_eq_zero, cos_sub_cos, ← sub_neg_eq_add, H, mul_assoc 2 π k,
mul_div_cancel_left₀ _ (two_ne_zero' ℝ), mul_comm π _, sin_int_mul_pi, mul_zero,
zero_mul]
#align real.angle.cos_eq_iff_coe_eq_or_eq_neg Real.Angle.cos_eq_iff_coe_eq_or_eq_neg
theorem sin_eq_iff_coe_eq_or_add_eq_pi {θ ψ : ℝ} :
sin θ = sin ψ ↔ (θ : Angle) = ψ ∨ (θ : Angle) + ψ = π := by
constructor
· intro Hsin
rw [← cos_pi_div_two_sub, ← cos_pi_div_two_sub] at Hsin
cases' cos_eq_iff_coe_eq_or_eq_neg.mp Hsin with h h
· left
rw [coe_sub, coe_sub] at h
exact sub_right_inj.1 h
right
rw [coe_sub, coe_sub, eq_neg_iff_add_eq_zero, add_sub, sub_add_eq_add_sub, ← coe_add,
add_halves, sub_sub, sub_eq_zero] at h
exact h.symm
· rw [angle_eq_iff_two_pi_dvd_sub, ← eq_sub_iff_add_eq, ← coe_sub, angle_eq_iff_two_pi_dvd_sub]
rintro (⟨k, H⟩ | ⟨k, H⟩)
· rw [← sub_eq_zero, sin_sub_sin, H, mul_assoc 2 π k, mul_div_cancel_left₀ _ (two_ne_zero' ℝ),
mul_comm π _, sin_int_mul_pi, mul_zero, zero_mul]
have H' : θ + ψ = 2 * k * π + π := by
rwa [← sub_add, sub_add_eq_add_sub, sub_eq_iff_eq_add, mul_assoc, mul_comm π _, ←
mul_assoc] at H
rw [← sub_eq_zero, sin_sub_sin, H', add_div, mul_assoc 2 _ π,
mul_div_cancel_left₀ _ (two_ne_zero' ℝ), cos_add_pi_div_two, sin_int_mul_pi, neg_zero,
mul_zero]
#align real.angle.sin_eq_iff_coe_eq_or_add_eq_pi Real.Angle.sin_eq_iff_coe_eq_or_add_eq_pi
theorem cos_sin_inj {θ ψ : ℝ} (Hcos : cos θ = cos ψ) (Hsin : sin θ = sin ψ) : (θ : Angle) = ψ := by
cases' cos_eq_iff_coe_eq_or_eq_neg.mp Hcos with hc hc; · exact hc
cases' sin_eq_iff_coe_eq_or_add_eq_pi.mp Hsin with hs hs; · exact hs
rw [eq_neg_iff_add_eq_zero, hs] at hc
obtain ⟨n, hn⟩ : ∃ n, n • _ = _ := QuotientAddGroup.leftRel_apply.mp (Quotient.exact' hc)
rw [← neg_one_mul, add_zero, ← sub_eq_zero, zsmul_eq_mul, ← mul_assoc, ← sub_mul, mul_eq_zero,
eq_false (ne_of_gt pi_pos), or_false_iff, sub_neg_eq_add, ← Int.cast_zero, ← Int.cast_one,
← Int.cast_ofNat, ← Int.cast_mul, ← Int.cast_add, Int.cast_inj] at hn
have : (n * 2 + 1) % (2 : ℤ) = 0 % (2 : ℤ) := congr_arg (· % (2 : ℤ)) hn
rw [add_comm, Int.add_mul_emod_self] at this
exact absurd this one_ne_zero
#align real.angle.cos_sin_inj Real.Angle.cos_sin_inj
def sin (θ : Angle) : ℝ :=
sin_periodic.lift θ
#align real.angle.sin Real.Angle.sin
@[simp]
theorem sin_coe (x : ℝ) : sin (x : Angle) = Real.sin x :=
rfl
#align real.angle.sin_coe Real.Angle.sin_coe
@[continuity]
theorem continuous_sin : Continuous sin :=
Real.continuous_sin.quotient_liftOn' _
#align real.angle.continuous_sin Real.Angle.continuous_sin
def cos (θ : Angle) : ℝ :=
cos_periodic.lift θ
#align real.angle.cos Real.Angle.cos
@[simp]
theorem cos_coe (x : ℝ) : cos (x : Angle) = Real.cos x :=
rfl
#align real.angle.cos_coe Real.Angle.cos_coe
@[continuity]
theorem continuous_cos : Continuous cos :=
Real.continuous_cos.quotient_liftOn' _
#align real.angle.continuous_cos Real.Angle.continuous_cos
theorem cos_eq_real_cos_iff_eq_or_eq_neg {θ : Angle} {ψ : ℝ} :
cos θ = Real.cos ψ ↔ θ = ψ ∨ θ = -ψ := by
induction θ using Real.Angle.induction_on
exact cos_eq_iff_coe_eq_or_eq_neg
#align real.angle.cos_eq_real_cos_iff_eq_or_eq_neg Real.Angle.cos_eq_real_cos_iff_eq_or_eq_neg
theorem cos_eq_iff_eq_or_eq_neg {θ ψ : Angle} : cos θ = cos ψ ↔ θ = ψ ∨ θ = -ψ := by
induction ψ using Real.Angle.induction_on
exact cos_eq_real_cos_iff_eq_or_eq_neg
#align real.angle.cos_eq_iff_eq_or_eq_neg Real.Angle.cos_eq_iff_eq_or_eq_neg
theorem sin_eq_real_sin_iff_eq_or_add_eq_pi {θ : Angle} {ψ : ℝ} :
sin θ = Real.sin ψ ↔ θ = ψ ∨ θ + ψ = π := by
induction θ using Real.Angle.induction_on
exact sin_eq_iff_coe_eq_or_add_eq_pi
#align real.angle.sin_eq_real_sin_iff_eq_or_add_eq_pi Real.Angle.sin_eq_real_sin_iff_eq_or_add_eq_pi
theorem sin_eq_iff_eq_or_add_eq_pi {θ ψ : Angle} : sin θ = sin ψ ↔ θ = ψ ∨ θ + ψ = π := by
induction ψ using Real.Angle.induction_on
exact sin_eq_real_sin_iff_eq_or_add_eq_pi
#align real.angle.sin_eq_iff_eq_or_add_eq_pi Real.Angle.sin_eq_iff_eq_or_add_eq_pi
@[simp]
theorem sin_zero : sin (0 : Angle) = 0 := by rw [← coe_zero, sin_coe, Real.sin_zero]
#align real.angle.sin_zero Real.Angle.sin_zero
-- Porting note (#10618): @[simp] can prove it
theorem sin_coe_pi : sin (π : Angle) = 0 := by rw [sin_coe, Real.sin_pi]
#align real.angle.sin_coe_pi Real.Angle.sin_coe_pi
theorem sin_eq_zero_iff {θ : Angle} : sin θ = 0 ↔ θ = 0 ∨ θ = π := by
nth_rw 1 [← sin_zero]
rw [sin_eq_iff_eq_or_add_eq_pi]
simp
#align real.angle.sin_eq_zero_iff Real.Angle.sin_eq_zero_iff
theorem sin_ne_zero_iff {θ : Angle} : sin θ ≠ 0 ↔ θ ≠ 0 ∧ θ ≠ π := by
rw [← not_or, ← sin_eq_zero_iff]
#align real.angle.sin_ne_zero_iff Real.Angle.sin_ne_zero_iff
@[simp]
theorem sin_neg (θ : Angle) : sin (-θ) = -sin θ := by
induction θ using Real.Angle.induction_on
exact Real.sin_neg _
#align real.angle.sin_neg Real.Angle.sin_neg
theorem sin_antiperiodic : Function.Antiperiodic sin (π : Angle) := by
intro θ
induction θ using Real.Angle.induction_on
exact Real.sin_antiperiodic _
#align real.angle.sin_antiperiodic Real.Angle.sin_antiperiodic
@[simp]
theorem sin_add_pi (θ : Angle) : sin (θ + π) = -sin θ :=
sin_antiperiodic θ
#align real.angle.sin_add_pi Real.Angle.sin_add_pi
@[simp]
theorem sin_sub_pi (θ : Angle) : sin (θ - π) = -sin θ :=
sin_antiperiodic.sub_eq θ
#align real.angle.sin_sub_pi Real.Angle.sin_sub_pi
@[simp]
theorem cos_zero : cos (0 : Angle) = 1 := by rw [← coe_zero, cos_coe, Real.cos_zero]
#align real.angle.cos_zero Real.Angle.cos_zero
-- Porting note (#10618): @[simp] can prove it
theorem cos_coe_pi : cos (π : Angle) = -1 := by rw [cos_coe, Real.cos_pi]
#align real.angle.cos_coe_pi Real.Angle.cos_coe_pi
@[simp]
theorem cos_neg (θ : Angle) : cos (-θ) = cos θ := by
induction θ using Real.Angle.induction_on
exact Real.cos_neg _
#align real.angle.cos_neg Real.Angle.cos_neg
theorem cos_antiperiodic : Function.Antiperiodic cos (π : Angle) := by
intro θ
induction θ using Real.Angle.induction_on
exact Real.cos_antiperiodic _
#align real.angle.cos_antiperiodic Real.Angle.cos_antiperiodic
@[simp]
theorem cos_add_pi (θ : Angle) : cos (θ + π) = -cos θ :=
cos_antiperiodic θ
#align real.angle.cos_add_pi Real.Angle.cos_add_pi
@[simp]
theorem cos_sub_pi (θ : Angle) : cos (θ - π) = -cos θ :=
cos_antiperiodic.sub_eq θ
#align real.angle.cos_sub_pi Real.Angle.cos_sub_pi
theorem cos_eq_zero_iff {θ : Angle} : cos θ = 0 ↔ θ = (π / 2 : ℝ) ∨ θ = (-π / 2 : ℝ) := by
rw [← cos_pi_div_two, ← cos_coe, cos_eq_iff_eq_or_eq_neg, ← coe_neg, ← neg_div]
#align real.angle.cos_eq_zero_iff Real.Angle.cos_eq_zero_iff
theorem sin_add (θ₁ θ₂ : Real.Angle) : sin (θ₁ + θ₂) = sin θ₁ * cos θ₂ + cos θ₁ * sin θ₂ := by
induction θ₁ using Real.Angle.induction_on
induction θ₂ using Real.Angle.induction_on
exact Real.sin_add _ _
#align real.angle.sin_add Real.Angle.sin_add
theorem cos_add (θ₁ θ₂ : Real.Angle) : cos (θ₁ + θ₂) = cos θ₁ * cos θ₂ - sin θ₁ * sin θ₂ := by
induction θ₂ using Real.Angle.induction_on
induction θ₁ using Real.Angle.induction_on
exact Real.cos_add _ _
#align real.angle.cos_add Real.Angle.cos_add
@[simp]
theorem cos_sq_add_sin_sq (θ : Real.Angle) : cos θ ^ 2 + sin θ ^ 2 = 1 := by
induction θ using Real.Angle.induction_on
exact Real.cos_sq_add_sin_sq _
#align real.angle.cos_sq_add_sin_sq Real.Angle.cos_sq_add_sin_sq
theorem sin_add_pi_div_two (θ : Angle) : sin (θ + ↑(π / 2)) = cos θ := by
induction θ using Real.Angle.induction_on
exact Real.sin_add_pi_div_two _
#align real.angle.sin_add_pi_div_two Real.Angle.sin_add_pi_div_two
theorem sin_sub_pi_div_two (θ : Angle) : sin (θ - ↑(π / 2)) = -cos θ := by
induction θ using Real.Angle.induction_on
exact Real.sin_sub_pi_div_two _
#align real.angle.sin_sub_pi_div_two Real.Angle.sin_sub_pi_div_two
theorem sin_pi_div_two_sub (θ : Angle) : sin (↑(π / 2) - θ) = cos θ := by
induction θ using Real.Angle.induction_on
exact Real.sin_pi_div_two_sub _
#align real.angle.sin_pi_div_two_sub Real.Angle.sin_pi_div_two_sub
theorem cos_add_pi_div_two (θ : Angle) : cos (θ + ↑(π / 2)) = -sin θ := by
induction θ using Real.Angle.induction_on
exact Real.cos_add_pi_div_two _
#align real.angle.cos_add_pi_div_two Real.Angle.cos_add_pi_div_two
theorem cos_sub_pi_div_two (θ : Angle) : cos (θ - ↑(π / 2)) = sin θ := by
induction θ using Real.Angle.induction_on
exact Real.cos_sub_pi_div_two _
#align real.angle.cos_sub_pi_div_two Real.Angle.cos_sub_pi_div_two
theorem cos_pi_div_two_sub (θ : Angle) : cos (↑(π / 2) - θ) = sin θ := by
induction θ using Real.Angle.induction_on
exact Real.cos_pi_div_two_sub _
#align real.angle.cos_pi_div_two_sub Real.Angle.cos_pi_div_two_sub
theorem abs_sin_eq_of_two_nsmul_eq {θ ψ : Angle} (h : (2 : ℕ) • θ = (2 : ℕ) • ψ) :
|sin θ| = |sin ψ| := by
rw [two_nsmul_eq_iff] at h
rcases h with (rfl | rfl)
· rfl
· rw [sin_add_pi, abs_neg]
#align real.angle.abs_sin_eq_of_two_nsmul_eq Real.Angle.abs_sin_eq_of_two_nsmul_eq
theorem abs_sin_eq_of_two_zsmul_eq {θ ψ : Angle} (h : (2 : ℤ) • θ = (2 : ℤ) • ψ) :
|sin θ| = |sin ψ| := by
simp_rw [two_zsmul, ← two_nsmul] at h
exact abs_sin_eq_of_two_nsmul_eq h
#align real.angle.abs_sin_eq_of_two_zsmul_eq Real.Angle.abs_sin_eq_of_two_zsmul_eq
theorem abs_cos_eq_of_two_nsmul_eq {θ ψ : Angle} (h : (2 : ℕ) • θ = (2 : ℕ) • ψ) :
|cos θ| = |cos ψ| := by
rw [two_nsmul_eq_iff] at h
rcases h with (rfl | rfl)
· rfl
· rw [cos_add_pi, abs_neg]
#align real.angle.abs_cos_eq_of_two_nsmul_eq Real.Angle.abs_cos_eq_of_two_nsmul_eq
theorem abs_cos_eq_of_two_zsmul_eq {θ ψ : Angle} (h : (2 : ℤ) • θ = (2 : ℤ) • ψ) :
|cos θ| = |cos ψ| := by
simp_rw [two_zsmul, ← two_nsmul] at h
exact abs_cos_eq_of_two_nsmul_eq h
#align real.angle.abs_cos_eq_of_two_zsmul_eq Real.Angle.abs_cos_eq_of_two_zsmul_eq
@[simp]
theorem coe_toIcoMod (θ ψ : ℝ) : ↑(toIcoMod two_pi_pos ψ θ) = (θ : Angle) := by
rw [angle_eq_iff_two_pi_dvd_sub]
refine ⟨-toIcoDiv two_pi_pos ψ θ, ?_⟩
rw [toIcoMod_sub_self, zsmul_eq_mul, mul_comm]
#align real.angle.coe_to_Ico_mod Real.Angle.coe_toIcoMod
@[simp]
theorem coe_toIocMod (θ ψ : ℝ) : ↑(toIocMod two_pi_pos ψ θ) = (θ : Angle) := by
rw [angle_eq_iff_two_pi_dvd_sub]
refine ⟨-toIocDiv two_pi_pos ψ θ, ?_⟩
rw [toIocMod_sub_self, zsmul_eq_mul, mul_comm]
#align real.angle.coe_to_Ioc_mod Real.Angle.coe_toIocMod
def toReal (θ : Angle) : ℝ :=
(toIocMod_periodic two_pi_pos (-π)).lift θ
#align real.angle.to_real Real.Angle.toReal
theorem toReal_coe (θ : ℝ) : (θ : Angle).toReal = toIocMod two_pi_pos (-π) θ :=
rfl
#align real.angle.to_real_coe Real.Angle.toReal_coe
theorem toReal_coe_eq_self_iff {θ : ℝ} : (θ : Angle).toReal = θ ↔ -π < θ ∧ θ ≤ π := by
rw [toReal_coe, toIocMod_eq_self two_pi_pos]
ring_nf
rfl
#align real.angle.to_real_coe_eq_self_iff Real.Angle.toReal_coe_eq_self_iff
theorem toReal_coe_eq_self_iff_mem_Ioc {θ : ℝ} : (θ : Angle).toReal = θ ↔ θ ∈ Set.Ioc (-π) π := by
rw [toReal_coe_eq_self_iff, ← Set.mem_Ioc]
#align real.angle.to_real_coe_eq_self_iff_mem_Ioc Real.Angle.toReal_coe_eq_self_iff_mem_Ioc
theorem toReal_injective : Function.Injective toReal := by
intro θ ψ h
induction θ using Real.Angle.induction_on
induction ψ using Real.Angle.induction_on
simpa [toReal_coe, toIocMod_eq_toIocMod, zsmul_eq_mul, mul_comm _ (2 * π), ←
angle_eq_iff_two_pi_dvd_sub, eq_comm] using h
#align real.angle.to_real_injective Real.Angle.toReal_injective
@[simp]
theorem toReal_inj {θ ψ : Angle} : θ.toReal = ψ.toReal ↔ θ = ψ :=
toReal_injective.eq_iff
#align real.angle.to_real_inj Real.Angle.toReal_inj
@[simp]
theorem coe_toReal (θ : Angle) : (θ.toReal : Angle) = θ := by
induction θ using Real.Angle.induction_on
exact coe_toIocMod _ _
#align real.angle.coe_to_real Real.Angle.coe_toReal
theorem neg_pi_lt_toReal (θ : Angle) : -π < θ.toReal := by
induction θ using Real.Angle.induction_on
exact left_lt_toIocMod _ _ _
#align real.angle.neg_pi_lt_to_real Real.Angle.neg_pi_lt_toReal
theorem toReal_le_pi (θ : Angle) : θ.toReal ≤ π := by
induction θ using Real.Angle.induction_on
convert toIocMod_le_right two_pi_pos _ _
ring
#align real.angle.to_real_le_pi Real.Angle.toReal_le_pi
theorem abs_toReal_le_pi (θ : Angle) : |θ.toReal| ≤ π :=
abs_le.2 ⟨(neg_pi_lt_toReal _).le, toReal_le_pi _⟩
#align real.angle.abs_to_real_le_pi Real.Angle.abs_toReal_le_pi
theorem toReal_mem_Ioc (θ : Angle) : θ.toReal ∈ Set.Ioc (-π) π :=
⟨neg_pi_lt_toReal _, toReal_le_pi _⟩
#align real.angle.to_real_mem_Ioc Real.Angle.toReal_mem_Ioc
@[simp]
theorem toIocMod_toReal (θ : Angle) : toIocMod two_pi_pos (-π) θ.toReal = θ.toReal := by
induction θ using Real.Angle.induction_on
rw [toReal_coe]
exact toIocMod_toIocMod _ _ _ _
#align real.angle.to_Ioc_mod_to_real Real.Angle.toIocMod_toReal
@[simp]
theorem toReal_zero : (0 : Angle).toReal = 0 := by
rw [← coe_zero, toReal_coe_eq_self_iff]
exact ⟨Left.neg_neg_iff.2 Real.pi_pos, Real.pi_pos.le⟩
#align real.angle.to_real_zero Real.Angle.toReal_zero
@[simp]
theorem toReal_eq_zero_iff {θ : Angle} : θ.toReal = 0 ↔ θ = 0 := by
nth_rw 1 [← toReal_zero]
exact toReal_inj
#align real.angle.to_real_eq_zero_iff Real.Angle.toReal_eq_zero_iff
@[simp]
theorem toReal_pi : (π : Angle).toReal = π := by
rw [toReal_coe_eq_self_iff]
exact ⟨Left.neg_lt_self Real.pi_pos, le_refl _⟩
#align real.angle.to_real_pi Real.Angle.toReal_pi
@[simp]
theorem toReal_eq_pi_iff {θ : Angle} : θ.toReal = π ↔ θ = π := by rw [← toReal_inj, toReal_pi]
#align real.angle.to_real_eq_pi_iff Real.Angle.toReal_eq_pi_iff
theorem pi_ne_zero : (π : Angle) ≠ 0 := by
rw [← toReal_injective.ne_iff, toReal_pi, toReal_zero]
exact Real.pi_ne_zero
#align real.angle.pi_ne_zero Real.Angle.pi_ne_zero
@[simp]
theorem toReal_pi_div_two : ((π / 2 : ℝ) : Angle).toReal = π / 2 :=
toReal_coe_eq_self_iff.2 <| by constructor <;> linarith [pi_pos]
#align real.angle.to_real_pi_div_two Real.Angle.toReal_pi_div_two
@[simp]
theorem toReal_eq_pi_div_two_iff {θ : Angle} : θ.toReal = π / 2 ↔ θ = (π / 2 : ℝ) := by
rw [← toReal_inj, toReal_pi_div_two]
#align real.angle.to_real_eq_pi_div_two_iff Real.Angle.toReal_eq_pi_div_two_iff
@[simp]
theorem toReal_neg_pi_div_two : ((-π / 2 : ℝ) : Angle).toReal = -π / 2 :=
toReal_coe_eq_self_iff.2 <| by constructor <;> linarith [pi_pos]
#align real.angle.to_real_neg_pi_div_two Real.Angle.toReal_neg_pi_div_two
@[simp]
theorem toReal_eq_neg_pi_div_two_iff {θ : Angle} : θ.toReal = -π / 2 ↔ θ = (-π / 2 : ℝ) := by
rw [← toReal_inj, toReal_neg_pi_div_two]
#align real.angle.to_real_eq_neg_pi_div_two_iff Real.Angle.toReal_eq_neg_pi_div_two_iff
theorem pi_div_two_ne_zero : ((π / 2 : ℝ) : Angle) ≠ 0 := by
rw [← toReal_injective.ne_iff, toReal_pi_div_two, toReal_zero]
exact div_ne_zero Real.pi_ne_zero two_ne_zero
#align real.angle.pi_div_two_ne_zero Real.Angle.pi_div_two_ne_zero
theorem neg_pi_div_two_ne_zero : ((-π / 2 : ℝ) : Angle) ≠ 0 := by
rw [← toReal_injective.ne_iff, toReal_neg_pi_div_two, toReal_zero]
exact div_ne_zero (neg_ne_zero.2 Real.pi_ne_zero) two_ne_zero
#align real.angle.neg_pi_div_two_ne_zero Real.Angle.neg_pi_div_two_ne_zero
theorem abs_toReal_coe_eq_self_iff {θ : ℝ} : |(θ : Angle).toReal| = θ ↔ 0 ≤ θ ∧ θ ≤ π :=
⟨fun h => h ▸ ⟨abs_nonneg _, abs_toReal_le_pi _⟩, fun h =>
(toReal_coe_eq_self_iff.2 ⟨(Left.neg_neg_iff.2 Real.pi_pos).trans_le h.1, h.2⟩).symm ▸
abs_eq_self.2 h.1⟩
#align real.angle.abs_to_real_coe_eq_self_iff Real.Angle.abs_toReal_coe_eq_self_iff
theorem abs_toReal_neg_coe_eq_self_iff {θ : ℝ} : |(-θ : Angle).toReal| = θ ↔ 0 ≤ θ ∧ θ ≤ π := by
refine ⟨fun h => h ▸ ⟨abs_nonneg _, abs_toReal_le_pi _⟩, fun h => ?_⟩
by_cases hnegpi : θ = π; · simp [hnegpi, Real.pi_pos.le]
rw [← coe_neg,
toReal_coe_eq_self_iff.2
⟨neg_lt_neg (lt_of_le_of_ne h.2 hnegpi), (neg_nonpos.2 h.1).trans Real.pi_pos.le⟩,
abs_neg, abs_eq_self.2 h.1]
#align real.angle.abs_to_real_neg_coe_eq_self_iff Real.Angle.abs_toReal_neg_coe_eq_self_iff
theorem abs_toReal_eq_pi_div_two_iff {θ : Angle} :
|θ.toReal| = π / 2 ↔ θ = (π / 2 : ℝ) ∨ θ = (-π / 2 : ℝ) := by
rw [abs_eq (div_nonneg Real.pi_pos.le two_pos.le), ← neg_div, toReal_eq_pi_div_two_iff,
toReal_eq_neg_pi_div_two_iff]
#align real.angle.abs_to_real_eq_pi_div_two_iff Real.Angle.abs_toReal_eq_pi_div_two_iff
theorem nsmul_toReal_eq_mul {n : ℕ} (h : n ≠ 0) {θ : Angle} :
(n • θ).toReal = n * θ.toReal ↔ θ.toReal ∈ Set.Ioc (-π / n) (π / n) := by
nth_rw 1 [← coe_toReal θ]
have h' : 0 < (n : ℝ) := mod_cast Nat.pos_of_ne_zero h
rw [← coe_nsmul, nsmul_eq_mul, toReal_coe_eq_self_iff, Set.mem_Ioc, div_lt_iff' h',
le_div_iff' h']
#align real.angle.nsmul_to_real_eq_mul Real.Angle.nsmul_toReal_eq_mul
theorem two_nsmul_toReal_eq_two_mul {θ : Angle} :
((2 : ℕ) • θ).toReal = 2 * θ.toReal ↔ θ.toReal ∈ Set.Ioc (-π / 2) (π / 2) :=
mod_cast nsmul_toReal_eq_mul two_ne_zero
#align real.angle.two_nsmul_to_real_eq_two_mul Real.Angle.two_nsmul_toReal_eq_two_mul
theorem two_zsmul_toReal_eq_two_mul {θ : Angle} :
((2 : ℤ) • θ).toReal = 2 * θ.toReal ↔ θ.toReal ∈ Set.Ioc (-π / 2) (π / 2) := by
rw [two_zsmul, ← two_nsmul, two_nsmul_toReal_eq_two_mul]
#align real.angle.two_zsmul_to_real_eq_two_mul Real.Angle.two_zsmul_toReal_eq_two_mul
theorem toReal_coe_eq_self_sub_two_mul_int_mul_pi_iff {θ : ℝ} {k : ℤ} :
(θ : Angle).toReal = θ - 2 * k * π ↔ θ ∈ Set.Ioc ((2 * k - 1 : ℝ) * π) ((2 * k + 1) * π) := by
rw [← sub_zero (θ : Angle), ← zsmul_zero k, ← coe_two_pi, ← coe_zsmul, ← coe_sub, zsmul_eq_mul, ←
mul_assoc, mul_comm (k : ℝ), toReal_coe_eq_self_iff, Set.mem_Ioc]
exact ⟨fun h => ⟨by linarith, by linarith⟩, fun h => ⟨by linarith, by linarith⟩⟩
#align real.angle.to_real_coe_eq_self_sub_two_mul_int_mul_pi_iff Real.Angle.toReal_coe_eq_self_sub_two_mul_int_mul_pi_iff
theorem toReal_coe_eq_self_sub_two_pi_iff {θ : ℝ} :
(θ : Angle).toReal = θ - 2 * π ↔ θ ∈ Set.Ioc π (3 * π) := by
convert @toReal_coe_eq_self_sub_two_mul_int_mul_pi_iff θ 1 <;> norm_num
#align real.angle.to_real_coe_eq_self_sub_two_pi_iff Real.Angle.toReal_coe_eq_self_sub_two_pi_iff
theorem toReal_coe_eq_self_add_two_pi_iff {θ : ℝ} :
(θ : Angle).toReal = θ + 2 * π ↔ θ ∈ Set.Ioc (-3 * π) (-π) := by
convert @toReal_coe_eq_self_sub_two_mul_int_mul_pi_iff θ (-1) using 2 <;>
set_option tactic.skipAssignedInstances false in norm_num
#align real.angle.to_real_coe_eq_self_add_two_pi_iff Real.Angle.toReal_coe_eq_self_add_two_pi_iff
theorem two_nsmul_toReal_eq_two_mul_sub_two_pi {θ : Angle} :
((2 : ℕ) • θ).toReal = 2 * θ.toReal - 2 * π ↔ π / 2 < θ.toReal := by
nth_rw 1 [← coe_toReal θ]
rw [← coe_nsmul, two_nsmul, ← two_mul, toReal_coe_eq_self_sub_two_pi_iff, Set.mem_Ioc]
exact
⟨fun h => by linarith, fun h =>
⟨(div_lt_iff' (zero_lt_two' ℝ)).1 h, by linarith [pi_pos, toReal_le_pi θ]⟩⟩
#align real.angle.two_nsmul_to_real_eq_two_mul_sub_two_pi Real.Angle.two_nsmul_toReal_eq_two_mul_sub_two_pi
theorem two_zsmul_toReal_eq_two_mul_sub_two_pi {θ : Angle} :
((2 : ℤ) • θ).toReal = 2 * θ.toReal - 2 * π ↔ π / 2 < θ.toReal := by
rw [two_zsmul, ← two_nsmul, two_nsmul_toReal_eq_two_mul_sub_two_pi]
#align real.angle.two_zsmul_to_real_eq_two_mul_sub_two_pi Real.Angle.two_zsmul_toReal_eq_two_mul_sub_two_pi
theorem two_nsmul_toReal_eq_two_mul_add_two_pi {θ : Angle} :
((2 : ℕ) • θ).toReal = 2 * θ.toReal + 2 * π ↔ θ.toReal ≤ -π / 2 := by
nth_rw 1 [← coe_toReal θ]
rw [← coe_nsmul, two_nsmul, ← two_mul, toReal_coe_eq_self_add_two_pi_iff, Set.mem_Ioc]
refine
⟨fun h => by linarith, fun h =>
⟨by linarith [pi_pos, neg_pi_lt_toReal θ], (le_div_iff' (zero_lt_two' ℝ)).1 h⟩⟩
#align real.angle.two_nsmul_to_real_eq_two_mul_add_two_pi Real.Angle.two_nsmul_toReal_eq_two_mul_add_two_pi
theorem two_zsmul_toReal_eq_two_mul_add_two_pi {θ : Angle} :
((2 : ℤ) • θ).toReal = 2 * θ.toReal + 2 * π ↔ θ.toReal ≤ -π / 2 := by
rw [two_zsmul, ← two_nsmul, two_nsmul_toReal_eq_two_mul_add_two_pi]
#align real.angle.two_zsmul_to_real_eq_two_mul_add_two_pi Real.Angle.two_zsmul_toReal_eq_two_mul_add_two_pi
@[simp]
theorem sin_toReal (θ : Angle) : Real.sin θ.toReal = sin θ := by
conv_rhs => rw [← coe_toReal θ, sin_coe]
#align real.angle.sin_to_real Real.Angle.sin_toReal
@[simp]
theorem cos_toReal (θ : Angle) : Real.cos θ.toReal = cos θ := by
conv_rhs => rw [← coe_toReal θ, cos_coe]
#align real.angle.cos_to_real Real.Angle.cos_toReal
theorem cos_nonneg_iff_abs_toReal_le_pi_div_two {θ : Angle} : 0 ≤ cos θ ↔ |θ.toReal| ≤ π / 2 := by
nth_rw 1 [← coe_toReal θ]
rw [abs_le, cos_coe]
refine ⟨fun h => ?_, cos_nonneg_of_mem_Icc⟩
by_contra hn
rw [not_and_or, not_le, not_le] at hn
refine (not_lt.2 h) ?_
rcases hn with (hn | hn)
· rw [← Real.cos_neg]
refine cos_neg_of_pi_div_two_lt_of_lt (by linarith) ?_
linarith [neg_pi_lt_toReal θ]
· refine cos_neg_of_pi_div_two_lt_of_lt hn ?_
linarith [toReal_le_pi θ]
#align real.angle.cos_nonneg_iff_abs_to_real_le_pi_div_two Real.Angle.cos_nonneg_iff_abs_toReal_le_pi_div_two
theorem cos_pos_iff_abs_toReal_lt_pi_div_two {θ : Angle} : 0 < cos θ ↔ |θ.toReal| < π / 2 := by
rw [lt_iff_le_and_ne, lt_iff_le_and_ne, cos_nonneg_iff_abs_toReal_le_pi_div_two, ←
and_congr_right]
rintro -
rw [Ne, Ne, not_iff_not, @eq_comm ℝ 0, abs_toReal_eq_pi_div_two_iff, cos_eq_zero_iff]
#align real.angle.cos_pos_iff_abs_to_real_lt_pi_div_two Real.Angle.cos_pos_iff_abs_toReal_lt_pi_div_two
theorem cos_neg_iff_pi_div_two_lt_abs_toReal {θ : Angle} : cos θ < 0 ↔ π / 2 < |θ.toReal| := by
rw [← not_le, ← not_le, not_iff_not, cos_nonneg_iff_abs_toReal_le_pi_div_two]
#align real.angle.cos_neg_iff_pi_div_two_lt_abs_to_real Real.Angle.cos_neg_iff_pi_div_two_lt_abs_toReal
| Mathlib/Analysis/SpecialFunctions/Trigonometric/Angle.lean | 763 | 766 | theorem abs_cos_eq_abs_sin_of_two_nsmul_add_two_nsmul_eq_pi {θ ψ : Angle}
(h : (2 : ℕ) • θ + (2 : ℕ) • ψ = π) : |cos θ| = |sin ψ| := by |
rw [← eq_sub_iff_add_eq, ← two_nsmul_coe_div_two, ← nsmul_sub, two_nsmul_eq_iff] at h
rcases h with (rfl | rfl) <;> simp [cos_pi_div_two_sub]
|
import Mathlib.Analysis.Calculus.Deriv.Support
import Mathlib.Analysis.SpecialFunctions.Pow.Deriv
import Mathlib.MeasureTheory.Integral.FundThmCalculus
import Mathlib.Order.Filter.AtTopBot
import Mathlib.MeasureTheory.Function.Jacobian
import Mathlib.MeasureTheory.Measure.Haar.NormedSpace
import Mathlib.MeasureTheory.Measure.Haar.Unique
#align_import measure_theory.integral.integral_eq_improper from "leanprover-community/mathlib"@"b84aee748341da06a6d78491367e2c0e9f15e8a5"
open MeasureTheory Filter Set TopologicalSpace
open scoped ENNReal NNReal Topology
namespace MeasureTheory
protected theorem AECover.restrict {φ : ι → Set α} (hφ : AECover μ l φ) {s : Set α} :
AECover (μ.restrict s) l φ :=
hφ.mono Measure.restrict_le_self
#align measure_theory.ae_cover.restrict MeasureTheory.AECover.restrict
theorem aecover_restrict_of_ae_imp {s : Set α} {φ : ι → Set α} (hs : MeasurableSet s)
(ae_eventually_mem : ∀ᵐ x ∂μ, x ∈ s → ∀ᶠ n in l, x ∈ φ n)
(measurable : ∀ n, MeasurableSet <| φ n) : AECover (μ.restrict s) l φ where
ae_eventually_mem := by rwa [ae_restrict_iff' hs]
measurableSet := measurable
#align measure_theory.ae_cover_restrict_of_ae_imp MeasureTheory.aecover_restrict_of_ae_imp
theorem AECover.inter_restrict {φ : ι → Set α} (hφ : AECover μ l φ) {s : Set α}
(hs : MeasurableSet s) : AECover (μ.restrict s) l fun i => φ i ∩ s :=
aecover_restrict_of_ae_imp hs
(hφ.ae_eventually_mem.mono fun _x hx hxs => hx.mono fun _i hi => ⟨hi, hxs⟩) fun i =>
(hφ.measurableSet i).inter hs
#align measure_theory.ae_cover.inter_restrict MeasureTheory.AECover.inter_restrict
theorem AECover.ae_tendsto_indicator {β : Type*} [Zero β] [TopologicalSpace β] (f : α → β)
{φ : ι → Set α} (hφ : AECover μ l φ) :
∀ᵐ x ∂μ, Tendsto (fun i => (φ i).indicator f x) l (𝓝 <| f x) :=
hφ.ae_eventually_mem.mono fun _x hx =>
tendsto_const_nhds.congr' <| hx.mono fun _n hn => (indicator_of_mem hn _).symm
#align measure_theory.ae_cover.ae_tendsto_indicator MeasureTheory.AECover.ae_tendsto_indicator
| Mathlib/MeasureTheory/Integral/IntegralEqImproper.lean | 331 | 338 | theorem AECover.aemeasurable {β : Type*} [MeasurableSpace β] [l.IsCountablyGenerated] [l.NeBot]
{f : α → β} {φ : ι → Set α} (hφ : AECover μ l φ)
(hfm : ∀ i, AEMeasurable f (μ.restrict <| φ i)) : AEMeasurable f μ := by |
obtain ⟨u, hu⟩ := l.exists_seq_tendsto
have := aemeasurable_iUnion_iff.mpr fun n : ℕ => hfm (u n)
rwa [Measure.restrict_eq_self_of_ae_mem] at this
filter_upwards [hφ.ae_eventually_mem] with x hx using
mem_iUnion.mpr (hu.eventually hx).exists
|
import Mathlib.Algebra.MonoidAlgebra.Degree
import Mathlib.Algebra.Polynomial.Coeff
import Mathlib.Algebra.Polynomial.Monomial
import Mathlib.Data.Fintype.BigOperators
import Mathlib.Data.Nat.WithBot
import Mathlib.Data.Nat.Cast.WithTop
import Mathlib.Data.Nat.SuccPred
#align_import data.polynomial.degree.definitions from "leanprover-community/mathlib"@"808ea4ebfabeb599f21ec4ae87d6dc969597887f"
-- Porting note: `Mathlib.Data.Nat.Cast.WithTop` should be imported for `Nat.cast_withBot`.
set_option linter.uppercaseLean3 false
noncomputable section
open Finsupp Finset
open Polynomial
namespace Polynomial
universe u v
variable {R : Type u} {S : Type v} {a b c d : R} {n m : ℕ}
section Semiring
variable [Semiring R] {p q r : R[X]}
def degree (p : R[X]) : WithBot ℕ :=
p.support.max
#align polynomial.degree Polynomial.degree
theorem supDegree_eq_degree (p : R[X]) : p.toFinsupp.supDegree WithBot.some = p.degree :=
max_eq_sup_coe
theorem degree_lt_wf : WellFounded fun p q : R[X] => degree p < degree q :=
InvImage.wf degree wellFounded_lt
#align polynomial.degree_lt_wf Polynomial.degree_lt_wf
instance : WellFoundedRelation R[X] :=
⟨_, degree_lt_wf⟩
def natDegree (p : R[X]) : ℕ :=
(degree p).unbot' 0
#align polynomial.nat_degree Polynomial.natDegree
def leadingCoeff (p : R[X]) : R :=
coeff p (natDegree p)
#align polynomial.leading_coeff Polynomial.leadingCoeff
def Monic (p : R[X]) :=
leadingCoeff p = (1 : R)
#align polynomial.monic Polynomial.Monic
@[nontriviality]
theorem monic_of_subsingleton [Subsingleton R] (p : R[X]) : Monic p :=
Subsingleton.elim _ _
#align polynomial.monic_of_subsingleton Polynomial.monic_of_subsingleton
theorem Monic.def : Monic p ↔ leadingCoeff p = 1 :=
Iff.rfl
#align polynomial.monic.def Polynomial.Monic.def
instance Monic.decidable [DecidableEq R] : Decidable (Monic p) := by unfold Monic; infer_instance
#align polynomial.monic.decidable Polynomial.Monic.decidable
@[simp]
theorem Monic.leadingCoeff {p : R[X]} (hp : p.Monic) : leadingCoeff p = 1 :=
hp
#align polynomial.monic.leading_coeff Polynomial.Monic.leadingCoeff
theorem Monic.coeff_natDegree {p : R[X]} (hp : p.Monic) : p.coeff p.natDegree = 1 :=
hp
#align polynomial.monic.coeff_nat_degree Polynomial.Monic.coeff_natDegree
@[simp]
theorem degree_zero : degree (0 : R[X]) = ⊥ :=
rfl
#align polynomial.degree_zero Polynomial.degree_zero
@[simp]
theorem natDegree_zero : natDegree (0 : R[X]) = 0 :=
rfl
#align polynomial.nat_degree_zero Polynomial.natDegree_zero
@[simp]
theorem coeff_natDegree : coeff p (natDegree p) = leadingCoeff p :=
rfl
#align polynomial.coeff_nat_degree Polynomial.coeff_natDegree
@[simp]
theorem degree_eq_bot : degree p = ⊥ ↔ p = 0 :=
⟨fun h => support_eq_empty.1 (Finset.max_eq_bot.1 h), fun h => h.symm ▸ rfl⟩
#align polynomial.degree_eq_bot Polynomial.degree_eq_bot
@[nontriviality]
theorem degree_of_subsingleton [Subsingleton R] : degree p = ⊥ := by
rw [Subsingleton.elim p 0, degree_zero]
#align polynomial.degree_of_subsingleton Polynomial.degree_of_subsingleton
@[nontriviality]
theorem natDegree_of_subsingleton [Subsingleton R] : natDegree p = 0 := by
rw [Subsingleton.elim p 0, natDegree_zero]
#align polynomial.nat_degree_of_subsingleton Polynomial.natDegree_of_subsingleton
theorem degree_eq_natDegree (hp : p ≠ 0) : degree p = (natDegree p : WithBot ℕ) := by
let ⟨n, hn⟩ := not_forall.1 (mt Option.eq_none_iff_forall_not_mem.2 (mt degree_eq_bot.1 hp))
have hn : degree p = some n := Classical.not_not.1 hn
rw [natDegree, hn]; rfl
#align polynomial.degree_eq_nat_degree Polynomial.degree_eq_natDegree
theorem supDegree_eq_natDegree (p : R[X]) : p.toFinsupp.supDegree id = p.natDegree := by
obtain rfl|h := eq_or_ne p 0
· simp
apply WithBot.coe_injective
rw [← AddMonoidAlgebra.supDegree_withBot_some_comp, Function.comp_id, supDegree_eq_degree,
degree_eq_natDegree h, Nat.cast_withBot]
rwa [support_toFinsupp, nonempty_iff_ne_empty, Ne, support_eq_empty]
theorem degree_eq_iff_natDegree_eq {p : R[X]} {n : ℕ} (hp : p ≠ 0) :
p.degree = n ↔ p.natDegree = n := by rw [degree_eq_natDegree hp]; exact WithBot.coe_eq_coe
#align polynomial.degree_eq_iff_nat_degree_eq Polynomial.degree_eq_iff_natDegree_eq
theorem degree_eq_iff_natDegree_eq_of_pos {p : R[X]} {n : ℕ} (hn : 0 < n) :
p.degree = n ↔ p.natDegree = n := by
obtain rfl|h := eq_or_ne p 0
· simp [hn.ne]
· exact degree_eq_iff_natDegree_eq h
#align polynomial.degree_eq_iff_nat_degree_eq_of_pos Polynomial.degree_eq_iff_natDegree_eq_of_pos
theorem natDegree_eq_of_degree_eq_some {p : R[X]} {n : ℕ} (h : degree p = n) : natDegree p = n := by
-- Porting note: `Nat.cast_withBot` is required.
rw [natDegree, h, Nat.cast_withBot, WithBot.unbot'_coe]
#align polynomial.nat_degree_eq_of_degree_eq_some Polynomial.natDegree_eq_of_degree_eq_some
theorem degree_ne_of_natDegree_ne {n : ℕ} : p.natDegree ≠ n → degree p ≠ n :=
mt natDegree_eq_of_degree_eq_some
#align polynomial.degree_ne_of_nat_degree_ne Polynomial.degree_ne_of_natDegree_ne
@[simp]
theorem degree_le_natDegree : degree p ≤ natDegree p :=
WithBot.giUnbot'Bot.gc.le_u_l _
#align polynomial.degree_le_nat_degree Polynomial.degree_le_natDegree
theorem natDegree_eq_of_degree_eq [Semiring S] {q : S[X]} (h : degree p = degree q) :
natDegree p = natDegree q := by unfold natDegree; rw [h]
#align polynomial.nat_degree_eq_of_degree_eq Polynomial.natDegree_eq_of_degree_eq
theorem le_degree_of_ne_zero (h : coeff p n ≠ 0) : (n : WithBot ℕ) ≤ degree p := by
rw [Nat.cast_withBot]
exact Finset.le_sup (mem_support_iff.2 h)
#align polynomial.le_degree_of_ne_zero Polynomial.le_degree_of_ne_zero
theorem le_natDegree_of_ne_zero (h : coeff p n ≠ 0) : n ≤ natDegree p := by
rw [← Nat.cast_le (α := WithBot ℕ), ← degree_eq_natDegree]
· exact le_degree_of_ne_zero h
· rintro rfl
exact h rfl
#align polynomial.le_nat_degree_of_ne_zero Polynomial.le_natDegree_of_ne_zero
theorem le_natDegree_of_mem_supp (a : ℕ) : a ∈ p.support → a ≤ natDegree p :=
le_natDegree_of_ne_zero ∘ mem_support_iff.mp
#align polynomial.le_nat_degree_of_mem_supp Polynomial.le_natDegree_of_mem_supp
theorem degree_eq_of_le_of_coeff_ne_zero (pn : p.degree ≤ n) (p1 : p.coeff n ≠ 0) : p.degree = n :=
pn.antisymm (le_degree_of_ne_zero p1)
#align polynomial.degree_eq_of_le_of_coeff_ne_zero Polynomial.degree_eq_of_le_of_coeff_ne_zero
theorem natDegree_eq_of_le_of_coeff_ne_zero (pn : p.natDegree ≤ n) (p1 : p.coeff n ≠ 0) :
p.natDegree = n :=
pn.antisymm (le_natDegree_of_ne_zero p1)
#align polynomial.nat_degree_eq_of_le_of_coeff_ne_zero Polynomial.natDegree_eq_of_le_of_coeff_ne_zero
theorem degree_mono [Semiring S] {f : R[X]} {g : S[X]} (h : f.support ⊆ g.support) :
f.degree ≤ g.degree :=
Finset.sup_mono h
#align polynomial.degree_mono Polynomial.degree_mono
theorem supp_subset_range (h : natDegree p < m) : p.support ⊆ Finset.range m := fun _n hn =>
mem_range.2 <| (le_natDegree_of_mem_supp _ hn).trans_lt h
#align polynomial.supp_subset_range Polynomial.supp_subset_range
theorem supp_subset_range_natDegree_succ : p.support ⊆ Finset.range (natDegree p + 1) :=
supp_subset_range (Nat.lt_succ_self _)
#align polynomial.supp_subset_range_nat_degree_succ Polynomial.supp_subset_range_natDegree_succ
theorem degree_le_degree (h : coeff q (natDegree p) ≠ 0) : degree p ≤ degree q := by
by_cases hp : p = 0
· rw [hp, degree_zero]
exact bot_le
· rw [degree_eq_natDegree hp]
exact le_degree_of_ne_zero h
#align polynomial.degree_le_degree Polynomial.degree_le_degree
theorem natDegree_le_iff_degree_le {n : ℕ} : natDegree p ≤ n ↔ degree p ≤ n :=
WithBot.unbot'_le_iff (fun _ ↦ bot_le)
#align polynomial.nat_degree_le_iff_degree_le Polynomial.natDegree_le_iff_degree_le
theorem natDegree_lt_iff_degree_lt (hp : p ≠ 0) : p.natDegree < n ↔ p.degree < ↑n :=
WithBot.unbot'_lt_iff (absurd · (degree_eq_bot.not.mpr hp))
#align polynomial.nat_degree_lt_iff_degree_lt Polynomial.natDegree_lt_iff_degree_lt
alias ⟨degree_le_of_natDegree_le, natDegree_le_of_degree_le⟩ := natDegree_le_iff_degree_le
#align polynomial.degree_le_of_nat_degree_le Polynomial.degree_le_of_natDegree_le
#align polynomial.nat_degree_le_of_degree_le Polynomial.natDegree_le_of_degree_le
theorem natDegree_le_natDegree [Semiring S] {q : S[X]} (hpq : p.degree ≤ q.degree) :
p.natDegree ≤ q.natDegree :=
WithBot.giUnbot'Bot.gc.monotone_l hpq
#align polynomial.nat_degree_le_nat_degree Polynomial.natDegree_le_natDegree
theorem natDegree_lt_natDegree {p q : R[X]} (hp : p ≠ 0) (hpq : p.degree < q.degree) :
p.natDegree < q.natDegree := by
by_cases hq : q = 0
· exact (not_lt_bot <| hq ▸ hpq).elim
rwa [degree_eq_natDegree hp, degree_eq_natDegree hq, Nat.cast_lt] at hpq
#align polynomial.nat_degree_lt_nat_degree Polynomial.natDegree_lt_natDegree
@[simp]
theorem degree_C (ha : a ≠ 0) : degree (C a) = (0 : WithBot ℕ) := by
rw [degree, ← monomial_zero_left, support_monomial 0 ha, max_eq_sup_coe, sup_singleton,
WithBot.coe_zero]
#align polynomial.degree_C Polynomial.degree_C
theorem degree_C_le : degree (C a) ≤ 0 := by
by_cases h : a = 0
· rw [h, C_0]
exact bot_le
· rw [degree_C h]
#align polynomial.degree_C_le Polynomial.degree_C_le
theorem degree_C_lt : degree (C a) < 1 :=
degree_C_le.trans_lt <| WithBot.coe_lt_coe.mpr zero_lt_one
#align polynomial.degree_C_lt Polynomial.degree_C_lt
theorem degree_one_le : degree (1 : R[X]) ≤ (0 : WithBot ℕ) := by rw [← C_1]; exact degree_C_le
#align polynomial.degree_one_le Polynomial.degree_one_le
@[simp]
theorem natDegree_C (a : R) : natDegree (C a) = 0 := by
by_cases ha : a = 0
· have : C a = 0 := by rw [ha, C_0]
rw [natDegree, degree_eq_bot.2 this, WithBot.unbot'_bot]
· rw [natDegree, degree_C ha, WithBot.unbot_zero']
#align polynomial.nat_degree_C Polynomial.natDegree_C
@[simp]
theorem natDegree_one : natDegree (1 : R[X]) = 0 :=
natDegree_C 1
#align polynomial.nat_degree_one Polynomial.natDegree_one
@[simp]
theorem natDegree_natCast (n : ℕ) : natDegree (n : R[X]) = 0 := by
simp only [← C_eq_natCast, natDegree_C]
#align polynomial.nat_degree_nat_cast Polynomial.natDegree_natCast
@[deprecated (since := "2024-04-17")]
alias natDegree_nat_cast := natDegree_natCast
theorem degree_natCast_le (n : ℕ) : degree (n : R[X]) ≤ 0 := degree_le_of_natDegree_le (by simp)
@[deprecated (since := "2024-04-17")]
alias degree_nat_cast_le := degree_natCast_le
@[simp]
theorem degree_monomial (n : ℕ) (ha : a ≠ 0) : degree (monomial n a) = n := by
rw [degree, support_monomial n ha, max_singleton, Nat.cast_withBot]
#align polynomial.degree_monomial Polynomial.degree_monomial
@[simp]
theorem degree_C_mul_X_pow (n : ℕ) (ha : a ≠ 0) : degree (C a * X ^ n) = n := by
rw [C_mul_X_pow_eq_monomial, degree_monomial n ha]
#align polynomial.degree_C_mul_X_pow Polynomial.degree_C_mul_X_pow
theorem degree_C_mul_X (ha : a ≠ 0) : degree (C a * X) = 1 := by
simpa only [pow_one] using degree_C_mul_X_pow 1 ha
#align polynomial.degree_C_mul_X Polynomial.degree_C_mul_X
theorem degree_monomial_le (n : ℕ) (a : R) : degree (monomial n a) ≤ n :=
letI := Classical.decEq R
if h : a = 0 then by rw [h, (monomial n).map_zero, degree_zero]; exact bot_le
else le_of_eq (degree_monomial n h)
#align polynomial.degree_monomial_le Polynomial.degree_monomial_le
theorem degree_C_mul_X_pow_le (n : ℕ) (a : R) : degree (C a * X ^ n) ≤ n := by
rw [C_mul_X_pow_eq_monomial]
apply degree_monomial_le
#align polynomial.degree_C_mul_X_pow_le Polynomial.degree_C_mul_X_pow_le
theorem degree_C_mul_X_le (a : R) : degree (C a * X) ≤ 1 := by
simpa only [pow_one] using degree_C_mul_X_pow_le 1 a
#align polynomial.degree_C_mul_X_le Polynomial.degree_C_mul_X_le
@[simp]
theorem natDegree_C_mul_X_pow (n : ℕ) (a : R) (ha : a ≠ 0) : natDegree (C a * X ^ n) = n :=
natDegree_eq_of_degree_eq_some (degree_C_mul_X_pow n ha)
#align polynomial.nat_degree_C_mul_X_pow Polynomial.natDegree_C_mul_X_pow
@[simp]
theorem natDegree_C_mul_X (a : R) (ha : a ≠ 0) : natDegree (C a * X) = 1 := by
simpa only [pow_one] using natDegree_C_mul_X_pow 1 a ha
#align polynomial.nat_degree_C_mul_X Polynomial.natDegree_C_mul_X
@[simp]
theorem natDegree_monomial [DecidableEq R] (i : ℕ) (r : R) :
natDegree (monomial i r) = if r = 0 then 0 else i := by
split_ifs with hr
· simp [hr]
· rw [← C_mul_X_pow_eq_monomial, natDegree_C_mul_X_pow i r hr]
#align polynomial.nat_degree_monomial Polynomial.natDegree_monomial
| Mathlib/Algebra/Polynomial/Degree/Definitions.lean | 338 | 342 | theorem natDegree_monomial_le (a : R) {m : ℕ} : (monomial m a).natDegree ≤ m := by |
classical
rw [Polynomial.natDegree_monomial]
split_ifs
exacts [Nat.zero_le _, le_rfl]
|
import Mathlib.NumberTheory.LegendreSymbol.QuadraticChar.Basic
import Mathlib.NumberTheory.GaussSum
#align_import number_theory.legendre_symbol.quadratic_char.gauss_sum from "leanprover-community/mathlib"@"5b2fe80501ff327b9109fb09b7cc8c325cd0d7d9"
section SpecialValues
open ZMod MulChar
variable {F : Type*} [Field F] [Fintype F]
theorem quadraticChar_two [DecidableEq F] (hF : ringChar F ≠ 2) :
quadraticChar F 2 = χ₈ (Fintype.card F) :=
IsQuadratic.eq_of_eq_coe (quadraticChar_isQuadratic F) isQuadratic_χ₈ hF
((quadraticChar_eq_pow_of_char_ne_two' hF 2).trans (FiniteField.two_pow_card hF))
#align quadratic_char_two quadraticChar_two
theorem FiniteField.isSquare_two_iff :
IsSquare (2 : F) ↔ Fintype.card F % 8 ≠ 3 ∧ Fintype.card F % 8 ≠ 5 := by
classical
by_cases hF : ringChar F = 2
focus
have h := FiniteField.even_card_of_char_two hF
simp only [FiniteField.isSquare_of_char_two hF, true_iff_iff]
rotate_left
focus
have h := FiniteField.odd_card_of_char_ne_two hF
rw [← quadraticChar_one_iff_isSquare (Ring.two_ne_zero hF), quadraticChar_two hF,
χ₈_nat_eq_if_mod_eight]
simp only [h, Nat.one_ne_zero, if_false, ite_eq_left_iff, Ne, (by decide : (-1 : ℤ) ≠ 1),
imp_false, Classical.not_not]
all_goals
rw [← Nat.mod_mod_of_dvd _ (by decide : 2 ∣ 8)] at h
have h₁ := Nat.mod_lt (Fintype.card F) (by decide : 0 < 8)
revert h₁ h
generalize Fintype.card F % 8 = n
intros; interval_cases n <;> simp_all -- Porting note (#11043): was `decide!`
#align finite_field.is_square_two_iff FiniteField.isSquare_two_iff
theorem quadraticChar_neg_two [DecidableEq F] (hF : ringChar F ≠ 2) :
quadraticChar F (-2) = χ₈' (Fintype.card F) := by
rw [(by norm_num : (-2 : F) = -1 * 2), map_mul, χ₈'_eq_χ₄_mul_χ₈, quadraticChar_neg_one hF,
quadraticChar_two hF, @cast_natCast _ (ZMod 4) _ _ _ (by decide : 4 ∣ 8)]
#align quadratic_char_neg_two quadraticChar_neg_two
| Mathlib/NumberTheory/LegendreSymbol/QuadraticChar/GaussSum.lean | 72 | 91 | theorem FiniteField.isSquare_neg_two_iff :
IsSquare (-2 : F) ↔ Fintype.card F % 8 ≠ 5 ∧ Fintype.card F % 8 ≠ 7 := by |
classical
by_cases hF : ringChar F = 2
focus
have h := FiniteField.even_card_of_char_two hF
simp only [FiniteField.isSquare_of_char_two hF, true_iff_iff]
rotate_left
focus
have h := FiniteField.odd_card_of_char_ne_two hF
rw [← quadraticChar_one_iff_isSquare (neg_ne_zero.mpr (Ring.two_ne_zero hF)),
quadraticChar_neg_two hF, χ₈'_nat_eq_if_mod_eight]
simp only [h, Nat.one_ne_zero, if_false, ite_eq_left_iff, Ne, (by decide : (-1 : ℤ) ≠ 1),
imp_false, Classical.not_not]
all_goals
rw [← Nat.mod_mod_of_dvd _ (by decide : 2 ∣ 8)] at h
have h₁ := Nat.mod_lt (Fintype.card F) (by decide : 0 < 8)
revert h₁ h
generalize Fintype.card F % 8 = n
intros; interval_cases n <;> simp_all -- Porting note (#11043): was `decide!`
|
import Mathlib.Algebra.Order.BigOperators.Group.Finset
import Mathlib.Data.Nat.Factors
import Mathlib.Order.Interval.Finset.Nat
#align_import number_theory.divisors from "leanprover-community/mathlib"@"e8638a0fcaf73e4500469f368ef9494e495099b3"
open scoped Classical
open Finset
namespace Nat
variable (n : ℕ)
def divisors : Finset ℕ :=
Finset.filter (fun x : ℕ => x ∣ n) (Finset.Ico 1 (n + 1))
#align nat.divisors Nat.divisors
def properDivisors : Finset ℕ :=
Finset.filter (fun x : ℕ => x ∣ n) (Finset.Ico 1 n)
#align nat.proper_divisors Nat.properDivisors
def divisorsAntidiagonal : Finset (ℕ × ℕ) :=
Finset.filter (fun x => x.fst * x.snd = n) (Ico 1 (n + 1) ×ˢ Ico 1 (n + 1))
#align nat.divisors_antidiagonal Nat.divisorsAntidiagonal
variable {n}
@[simp]
theorem filter_dvd_eq_divisors (h : n ≠ 0) : (Finset.range n.succ).filter (· ∣ n) = n.divisors := by
ext
simp only [divisors, mem_filter, mem_range, mem_Ico, and_congr_left_iff, iff_and_self]
exact fun ha _ => succ_le_iff.mpr (pos_of_dvd_of_pos ha h.bot_lt)
#align nat.filter_dvd_eq_divisors Nat.filter_dvd_eq_divisors
@[simp]
theorem filter_dvd_eq_properDivisors (h : n ≠ 0) :
(Finset.range n).filter (· ∣ n) = n.properDivisors := by
ext
simp only [properDivisors, mem_filter, mem_range, mem_Ico, and_congr_left_iff, iff_and_self]
exact fun ha _ => succ_le_iff.mpr (pos_of_dvd_of_pos ha h.bot_lt)
#align nat.filter_dvd_eq_proper_divisors Nat.filter_dvd_eq_properDivisors
theorem properDivisors.not_self_mem : ¬n ∈ properDivisors n := by simp [properDivisors]
#align nat.proper_divisors.not_self_mem Nat.properDivisors.not_self_mem
@[simp]
theorem mem_properDivisors {m : ℕ} : n ∈ properDivisors m ↔ n ∣ m ∧ n < m := by
rcases eq_or_ne m 0 with (rfl | hm); · simp [properDivisors]
simp only [and_comm, ← filter_dvd_eq_properDivisors hm, mem_filter, mem_range]
#align nat.mem_proper_divisors Nat.mem_properDivisors
theorem insert_self_properDivisors (h : n ≠ 0) : insert n (properDivisors n) = divisors n := by
rw [divisors, properDivisors, Ico_succ_right_eq_insert_Ico (one_le_iff_ne_zero.2 h),
Finset.filter_insert, if_pos (dvd_refl n)]
#align nat.insert_self_proper_divisors Nat.insert_self_properDivisors
theorem cons_self_properDivisors (h : n ≠ 0) :
cons n (properDivisors n) properDivisors.not_self_mem = divisors n := by
rw [cons_eq_insert, insert_self_properDivisors h]
#align nat.cons_self_proper_divisors Nat.cons_self_properDivisors
@[simp]
theorem mem_divisors {m : ℕ} : n ∈ divisors m ↔ n ∣ m ∧ m ≠ 0 := by
rcases eq_or_ne m 0 with (rfl | hm); · simp [divisors]
simp only [hm, Ne, not_false_iff, and_true_iff, ← filter_dvd_eq_divisors hm, mem_filter,
mem_range, and_iff_right_iff_imp, Nat.lt_succ_iff]
exact le_of_dvd hm.bot_lt
#align nat.mem_divisors Nat.mem_divisors
theorem one_mem_divisors : 1 ∈ divisors n ↔ n ≠ 0 := by simp
#align nat.one_mem_divisors Nat.one_mem_divisors
theorem mem_divisors_self (n : ℕ) (h : n ≠ 0) : n ∈ n.divisors :=
mem_divisors.2 ⟨dvd_rfl, h⟩
#align nat.mem_divisors_self Nat.mem_divisors_self
theorem dvd_of_mem_divisors {m : ℕ} (h : n ∈ divisors m) : n ∣ m := by
cases m
· apply dvd_zero
· simp [mem_divisors.1 h]
#align nat.dvd_of_mem_divisors Nat.dvd_of_mem_divisors
@[simp]
theorem mem_divisorsAntidiagonal {x : ℕ × ℕ} :
x ∈ divisorsAntidiagonal n ↔ x.fst * x.snd = n ∧ n ≠ 0 := by
simp only [divisorsAntidiagonal, Finset.mem_Ico, Ne, Finset.mem_filter, Finset.mem_product]
rw [and_comm]
apply and_congr_right
rintro rfl
constructor <;> intro h
· contrapose! h
simp [h]
· rw [Nat.lt_add_one_iff, Nat.lt_add_one_iff]
rw [mul_eq_zero, not_or] at h
simp only [succ_le_of_lt (Nat.pos_of_ne_zero h.1), succ_le_of_lt (Nat.pos_of_ne_zero h.2),
true_and_iff]
exact
⟨Nat.le_mul_of_pos_right _ (Nat.pos_of_ne_zero h.2),
Nat.le_mul_of_pos_left _ (Nat.pos_of_ne_zero h.1)⟩
#align nat.mem_divisors_antidiagonal Nat.mem_divisorsAntidiagonal
lemma ne_zero_of_mem_divisorsAntidiagonal {p : ℕ × ℕ} (hp : p ∈ n.divisorsAntidiagonal) :
p.1 ≠ 0 ∧ p.2 ≠ 0 := by
obtain ⟨hp₁, hp₂⟩ := Nat.mem_divisorsAntidiagonal.mp hp
exact mul_ne_zero_iff.mp (hp₁.symm ▸ hp₂)
lemma left_ne_zero_of_mem_divisorsAntidiagonal {p : ℕ × ℕ} (hp : p ∈ n.divisorsAntidiagonal) :
p.1 ≠ 0 :=
(ne_zero_of_mem_divisorsAntidiagonal hp).1
lemma right_ne_zero_of_mem_divisorsAntidiagonal {p : ℕ × ℕ} (hp : p ∈ n.divisorsAntidiagonal) :
p.2 ≠ 0 :=
(ne_zero_of_mem_divisorsAntidiagonal hp).2
theorem divisor_le {m : ℕ} : n ∈ divisors m → n ≤ m := by
cases' m with m
· simp
· simp only [mem_divisors, Nat.succ_ne_zero m, and_true_iff, Ne, not_false_iff]
exact Nat.le_of_dvd (Nat.succ_pos m)
#align nat.divisor_le Nat.divisor_le
theorem divisors_subset_of_dvd {m : ℕ} (hzero : n ≠ 0) (h : m ∣ n) : divisors m ⊆ divisors n :=
Finset.subset_iff.2 fun _x hx => Nat.mem_divisors.mpr ⟨(Nat.mem_divisors.mp hx).1.trans h, hzero⟩
#align nat.divisors_subset_of_dvd Nat.divisors_subset_of_dvd
theorem divisors_subset_properDivisors {m : ℕ} (hzero : n ≠ 0) (h : m ∣ n) (hdiff : m ≠ n) :
divisors m ⊆ properDivisors n := by
apply Finset.subset_iff.2
intro x hx
exact
Nat.mem_properDivisors.2
⟨(Nat.mem_divisors.1 hx).1.trans h,
lt_of_le_of_lt (divisor_le hx)
(lt_of_le_of_ne (divisor_le (Nat.mem_divisors.2 ⟨h, hzero⟩)) hdiff)⟩
#align nat.divisors_subset_proper_divisors Nat.divisors_subset_properDivisors
lemma divisors_filter_dvd_of_dvd {n m : ℕ} (hn : n ≠ 0) (hm : m ∣ n) :
(n.divisors.filter (· ∣ m)) = m.divisors := by
ext k
simp_rw [mem_filter, mem_divisors]
exact ⟨fun ⟨_, hkm⟩ ↦ ⟨hkm, ne_zero_of_dvd_ne_zero hn hm⟩, fun ⟨hk, _⟩ ↦ ⟨⟨hk.trans hm, hn⟩, hk⟩⟩
@[simp]
theorem divisors_zero : divisors 0 = ∅ := by
ext
simp
#align nat.divisors_zero Nat.divisors_zero
@[simp]
theorem properDivisors_zero : properDivisors 0 = ∅ := by
ext
simp
#align nat.proper_divisors_zero Nat.properDivisors_zero
@[simp]
lemma nonempty_divisors : (divisors n).Nonempty ↔ n ≠ 0 :=
⟨fun ⟨m, hm⟩ hn ↦ by simp [hn] at hm, fun hn ↦ ⟨1, one_mem_divisors.2 hn⟩⟩
@[simp]
lemma divisors_eq_empty : divisors n = ∅ ↔ n = 0 :=
not_nonempty_iff_eq_empty.symm.trans nonempty_divisors.not_left
theorem properDivisors_subset_divisors : properDivisors n ⊆ divisors n :=
filter_subset_filter _ <| Ico_subset_Ico_right n.le_succ
#align nat.proper_divisors_subset_divisors Nat.properDivisors_subset_divisors
@[simp]
theorem divisors_one : divisors 1 = {1} := by
ext
simp
#align nat.divisors_one Nat.divisors_one
@[simp]
theorem properDivisors_one : properDivisors 1 = ∅ := by rw [properDivisors, Ico_self, filter_empty]
#align nat.proper_divisors_one Nat.properDivisors_one
theorem pos_of_mem_divisors {m : ℕ} (h : m ∈ n.divisors) : 0 < m := by
cases m
· rw [mem_divisors, zero_dvd_iff (a := n)] at h
cases h.2 h.1
apply Nat.succ_pos
#align nat.pos_of_mem_divisors Nat.pos_of_mem_divisors
theorem pos_of_mem_properDivisors {m : ℕ} (h : m ∈ n.properDivisors) : 0 < m :=
pos_of_mem_divisors (properDivisors_subset_divisors h)
#align nat.pos_of_mem_proper_divisors Nat.pos_of_mem_properDivisors
theorem one_mem_properDivisors_iff_one_lt : 1 ∈ n.properDivisors ↔ 1 < n := by
rw [mem_properDivisors, and_iff_right (one_dvd _)]
#align nat.one_mem_proper_divisors_iff_one_lt Nat.one_mem_properDivisors_iff_one_lt
@[simp]
lemma sup_divisors_id (n : ℕ) : n.divisors.sup id = n := by
refine le_antisymm (Finset.sup_le fun _ ↦ divisor_le) ?_
rcases Decidable.eq_or_ne n 0 with rfl | hn
· apply zero_le
· exact Finset.le_sup (f := id) <| mem_divisors_self n hn
lemma one_lt_of_mem_properDivisors {m n : ℕ} (h : m ∈ n.properDivisors) : 1 < n :=
lt_of_le_of_lt (pos_of_mem_properDivisors h) (mem_properDivisors.1 h).2
lemma one_lt_div_of_mem_properDivisors {m n : ℕ} (h : m ∈ n.properDivisors) :
1 < n / m := by
obtain ⟨h_dvd, h_lt⟩ := mem_properDivisors.mp h
rwa [Nat.lt_div_iff_mul_lt h_dvd, mul_one]
lemma mem_properDivisors_iff_exists {m n : ℕ} (hn : n ≠ 0) :
m ∈ n.properDivisors ↔ ∃ k > 1, n = m * k := by
refine ⟨fun h ↦ ⟨n / m, one_lt_div_of_mem_properDivisors h, ?_⟩, ?_⟩
· exact (Nat.mul_div_cancel' (mem_properDivisors.mp h).1).symm
· rintro ⟨k, hk, rfl⟩
rw [mul_ne_zero_iff] at hn
exact mem_properDivisors.mpr ⟨⟨k, rfl⟩, lt_mul_of_one_lt_right (Nat.pos_of_ne_zero hn.1) hk⟩
@[simp]
lemma nonempty_properDivisors : n.properDivisors.Nonempty ↔ 1 < n :=
⟨fun ⟨_m, hm⟩ ↦ one_lt_of_mem_properDivisors hm, fun hn ↦
⟨1, one_mem_properDivisors_iff_one_lt.2 hn⟩⟩
@[simp]
lemma properDivisors_eq_empty : n.properDivisors = ∅ ↔ n ≤ 1 := by
rw [← not_nonempty_iff_eq_empty, nonempty_properDivisors, not_lt]
@[simp]
theorem divisorsAntidiagonal_zero : divisorsAntidiagonal 0 = ∅ := by
ext
simp
#align nat.divisors_antidiagonal_zero Nat.divisorsAntidiagonal_zero
@[simp]
theorem divisorsAntidiagonal_one : divisorsAntidiagonal 1 = {(1, 1)} := by
ext
simp [mul_eq_one, Prod.ext_iff]
#align nat.divisors_antidiagonal_one Nat.divisorsAntidiagonal_one
-- @[simp]
theorem swap_mem_divisorsAntidiagonal {x : ℕ × ℕ} :
x.swap ∈ divisorsAntidiagonal n ↔ x ∈ divisorsAntidiagonal n := by
rw [mem_divisorsAntidiagonal, mem_divisorsAntidiagonal, mul_comm, Prod.swap]
#align nat.swap_mem_divisors_antidiagonal Nat.swap_mem_divisorsAntidiagonal
-- Porting note: added below thm to replace the simp from the previous thm
@[simp]
theorem swap_mem_divisorsAntidiagonal_aux {x : ℕ × ℕ} :
x.snd * x.fst = n ∧ ¬n = 0 ↔ x ∈ divisorsAntidiagonal n := by
rw [mem_divisorsAntidiagonal, mul_comm]
theorem fst_mem_divisors_of_mem_antidiagonal {x : ℕ × ℕ} (h : x ∈ divisorsAntidiagonal n) :
x.fst ∈ divisors n := by
rw [mem_divisorsAntidiagonal] at h
simp [Dvd.intro _ h.1, h.2]
#align nat.fst_mem_divisors_of_mem_antidiagonal Nat.fst_mem_divisors_of_mem_antidiagonal
theorem snd_mem_divisors_of_mem_antidiagonal {x : ℕ × ℕ} (h : x ∈ divisorsAntidiagonal n) :
x.snd ∈ divisors n := by
rw [mem_divisorsAntidiagonal] at h
simp [Dvd.intro_left _ h.1, h.2]
#align nat.snd_mem_divisors_of_mem_antidiagonal Nat.snd_mem_divisors_of_mem_antidiagonal
@[simp]
theorem map_swap_divisorsAntidiagonal :
(divisorsAntidiagonal n).map (Equiv.prodComm _ _).toEmbedding = divisorsAntidiagonal n := by
rw [← coe_inj, coe_map, Equiv.coe_toEmbedding, Equiv.coe_prodComm,
Set.image_swap_eq_preimage_swap]
ext
exact swap_mem_divisorsAntidiagonal
#align nat.map_swap_divisors_antidiagonal Nat.map_swap_divisorsAntidiagonal
@[simp]
theorem image_fst_divisorsAntidiagonal : (divisorsAntidiagonal n).image Prod.fst = divisors n := by
ext
simp [Dvd.dvd, @eq_comm _ n (_ * _)]
#align nat.image_fst_divisors_antidiagonal Nat.image_fst_divisorsAntidiagonal
@[simp]
theorem image_snd_divisorsAntidiagonal : (divisorsAntidiagonal n).image Prod.snd = divisors n := by
rw [← map_swap_divisorsAntidiagonal, map_eq_image, image_image]
exact image_fst_divisorsAntidiagonal
#align nat.image_snd_divisors_antidiagonal Nat.image_snd_divisorsAntidiagonal
theorem map_div_right_divisors :
n.divisors.map ⟨fun d => (d, n / d), fun p₁ p₂ => congr_arg Prod.fst⟩ =
n.divisorsAntidiagonal := by
ext ⟨d, nd⟩
simp only [mem_map, mem_divisorsAntidiagonal, Function.Embedding.coeFn_mk, mem_divisors,
Prod.ext_iff, exists_prop, and_left_comm, exists_eq_left]
constructor
· rintro ⟨⟨⟨k, rfl⟩, hn⟩, rfl⟩
rw [Nat.mul_div_cancel_left _ (left_ne_zero_of_mul hn).bot_lt]
exact ⟨rfl, hn⟩
· rintro ⟨rfl, hn⟩
exact ⟨⟨dvd_mul_right _ _, hn⟩, Nat.mul_div_cancel_left _ (left_ne_zero_of_mul hn).bot_lt⟩
#align nat.map_div_right_divisors Nat.map_div_right_divisors
| Mathlib/NumberTheory/Divisors.lean | 333 | 339 | theorem map_div_left_divisors :
n.divisors.map ⟨fun d => (n / d, d), fun p₁ p₂ => congr_arg Prod.snd⟩ =
n.divisorsAntidiagonal := by |
apply Finset.map_injective (Equiv.prodComm _ _).toEmbedding
ext
rw [map_swap_divisorsAntidiagonal, ← map_div_right_divisors, Finset.map_map]
simp
|
import Mathlib.Analysis.SpecialFunctions.Pow.NNReal
#align_import analysis.special_functions.pow.asymptotics from "leanprover-community/mathlib"@"0b9eaaa7686280fad8cce467f5c3c57ee6ce77f8"
set_option linter.uppercaseLean3 false
noncomputable section
open scoped Classical
open Real Topology NNReal ENNReal Filter ComplexConjugate Finset Set
section Limits
open Real Filter
theorem tendsto_rpow_atTop {y : ℝ} (hy : 0 < y) : Tendsto (fun x : ℝ => x ^ y) atTop atTop := by
rw [tendsto_atTop_atTop]
intro b
use max b 0 ^ (1 / y)
intro x hx
exact
le_of_max_le_left
(by
convert rpow_le_rpow (rpow_nonneg (le_max_right b 0) (1 / y)) hx (le_of_lt hy)
using 1
rw [← rpow_mul (le_max_right b 0), (eq_div_iff (ne_of_gt hy)).mp rfl, Real.rpow_one])
#align tendsto_rpow_at_top tendsto_rpow_atTop
theorem tendsto_rpow_neg_atTop {y : ℝ} (hy : 0 < y) : Tendsto (fun x : ℝ => x ^ (-y)) atTop (𝓝 0) :=
Tendsto.congr' (eventuallyEq_of_mem (Ioi_mem_atTop 0) fun _ hx => (rpow_neg (le_of_lt hx) y).symm)
(tendsto_rpow_atTop hy).inv_tendsto_atTop
#align tendsto_rpow_neg_at_top tendsto_rpow_neg_atTop
open Asymptotics in
lemma tendsto_rpow_atTop_of_base_lt_one (b : ℝ) (hb₀ : -1 < b) (hb₁ : b < 1) :
Tendsto (b ^ · : ℝ → ℝ) atTop (𝓝 (0:ℝ)) := by
rcases lt_trichotomy b 0 with hb|rfl|hb
case inl => -- b < 0
simp_rw [Real.rpow_def_of_nonpos hb.le, hb.ne, ite_false]
rw [← isLittleO_const_iff (c := (1:ℝ)) one_ne_zero, (one_mul (1 : ℝ)).symm]
refine IsLittleO.mul_isBigO ?exp ?cos
case exp =>
rw [isLittleO_const_iff one_ne_zero]
refine tendsto_exp_atBot.comp <| (tendsto_const_mul_atBot_of_neg ?_).mpr tendsto_id
rw [← log_neg_eq_log, log_neg_iff (by linarith)]
linarith
case cos =>
rw [isBigO_iff]
exact ⟨1, eventually_of_forall fun x => by simp [Real.abs_cos_le_one]⟩
case inr.inl => -- b = 0
refine Tendsto.mono_right ?_ (Iff.mpr pure_le_nhds_iff rfl)
rw [tendsto_pure]
filter_upwards [eventually_ne_atTop 0] with _ hx
simp [hx]
case inr.inr => -- b > 0
simp_rw [Real.rpow_def_of_pos hb]
refine tendsto_exp_atBot.comp <| (tendsto_const_mul_atBot_of_neg ?_).mpr tendsto_id
exact (log_neg_iff hb).mpr hb₁
lemma tendsto_rpow_atTop_of_base_gt_one (b : ℝ) (hb : 1 < b) :
Tendsto (b ^ · : ℝ → ℝ) atBot (𝓝 (0:ℝ)) := by
simp_rw [Real.rpow_def_of_pos (by positivity : 0 < b)]
refine tendsto_exp_atBot.comp <| (tendsto_const_mul_atBot_of_pos ?_).mpr tendsto_id
exact (log_pos_iff (by positivity)).mpr <| by aesop
lemma tendsto_rpow_atBot_of_base_lt_one (b : ℝ) (hb₀ : 0 < b) (hb₁ : b < 1) :
Tendsto (b ^ · : ℝ → ℝ) atBot atTop := by
simp_rw [Real.rpow_def_of_pos (by positivity : 0 < b)]
refine tendsto_exp_atTop.comp <| (tendsto_const_mul_atTop_iff_neg <| tendsto_id (α := ℝ)).mpr ?_
exact (log_neg_iff hb₀).mpr hb₁
lemma tendsto_rpow_atBot_of_base_gt_one (b : ℝ) (hb : 1 < b) :
Tendsto (b ^ · : ℝ → ℝ) atBot (𝓝 0) := by
simp_rw [Real.rpow_def_of_pos (by positivity : 0 < b)]
refine tendsto_exp_atBot.comp <| (tendsto_const_mul_atBot_iff_pos <| tendsto_id (α := ℝ)).mpr ?_
exact (log_pos_iff (by positivity)).mpr <| by aesop
theorem tendsto_rpow_div_mul_add (a b c : ℝ) (hb : 0 ≠ b) :
Tendsto (fun x => x ^ (a / (b * x + c))) atTop (𝓝 1) := by
refine
Tendsto.congr' ?_
((tendsto_exp_nhds_zero_nhds_one.comp
(by
simpa only [mul_zero, pow_one] using
(tendsto_const_nhds (x := a)).mul
(tendsto_div_pow_mul_exp_add_atTop b c 1 hb))).comp
tendsto_log_atTop)
apply eventuallyEq_of_mem (Ioi_mem_atTop (0 : ℝ))
intro x hx
simp only [Set.mem_Ioi, Function.comp_apply] at hx ⊢
rw [exp_log hx, ← exp_log (rpow_pos_of_pos hx (a / (b * x + c))), log_rpow hx (a / (b * x + c))]
field_simp
#align tendsto_rpow_div_mul_add tendsto_rpow_div_mul_add
theorem tendsto_rpow_div : Tendsto (fun x => x ^ ((1 : ℝ) / x)) atTop (𝓝 1) := by
convert tendsto_rpow_div_mul_add (1 : ℝ) _ (0 : ℝ) zero_ne_one
ring
#align tendsto_rpow_div tendsto_rpow_div
| Mathlib/Analysis/SpecialFunctions/Pow/Asymptotics.lean | 126 | 128 | theorem tendsto_rpow_neg_div : Tendsto (fun x => x ^ (-(1 : ℝ) / x)) atTop (𝓝 1) := by |
convert tendsto_rpow_div_mul_add (-(1 : ℝ)) _ (0 : ℝ) zero_ne_one
ring
|
import Mathlib.Algebra.Field.Defs
import Mathlib.Algebra.GroupWithZero.Units.Lemmas
import Mathlib.Algebra.Ring.Commute
import Mathlib.Algebra.Ring.Invertible
import Mathlib.Order.Synonym
#align_import algebra.field.basic from "leanprover-community/mathlib"@"05101c3df9d9cfe9430edc205860c79b6d660102"
open Function OrderDual Set
universe u
variable {α β K : Type*}
section Field
variable [Field K]
attribute [local simp] mul_assoc mul_comm mul_left_comm
@[field_simps]
theorem div_sub_div (a : K) {b : K} (c : K) {d : K} (hb : b ≠ 0) (hd : d ≠ 0) :
a / b - c / d = (a * d - b * c) / (b * d) :=
(Commute.all b _).div_sub_div (Commute.all _ _) hb hd
#align div_sub_div div_sub_div
theorem inv_sub_inv {a b : K} (ha : a ≠ 0) (hb : b ≠ 0) : a⁻¹ - b⁻¹ = (b - a) / (a * b) := by
rw [inv_eq_one_div, inv_eq_one_div, div_sub_div _ _ ha hb, one_mul, mul_one]
#align inv_sub_inv inv_sub_inv
@[field_simps]
theorem sub_div' (a b c : K) (hc : c ≠ 0) : b - a / c = (b * c - a) / c := by
simpa using div_sub_div b a one_ne_zero hc
#align sub_div' sub_div'
@[field_simps]
| Mathlib/Algebra/Field/Basic.lean | 246 | 247 | theorem div_sub' (a b c : K) (hc : c ≠ 0) : a / c - b = (a - c * b) / c := by |
simpa using div_sub_div a b hc one_ne_zero
|
import Mathlib.Algebra.Group.Int
import Mathlib.Algebra.Order.Group.Abs
#align_import data.int.order.basic from "leanprover-community/mathlib"@"e8638a0fcaf73e4500469f368ef9494e495099b3"
-- We should need only a minimal development of sets in order to get here.
assert_not_exists Set.Subsingleton
assert_not_exists Ring
open Function Nat
namespace Int
theorem natCast_strictMono : StrictMono (· : ℕ → ℤ) := fun _ _ ↦ Int.ofNat_lt.2
#align int.coe_nat_strict_mono Int.natCast_strictMono
@[deprecated (since := "2024-05-25")] alias coe_nat_strictMono := natCast_strictMono
instance linearOrderedAddCommGroup : LinearOrderedAddCommGroup ℤ where
__ := instLinearOrder
__ := instAddCommGroup
add_le_add_left _ _ := Int.add_le_add_left
theorem abs_eq_natAbs : ∀ a : ℤ, |a| = natAbs a
| (n : ℕ) => abs_of_nonneg <| ofNat_zero_le _
| -[_+1] => abs_of_nonpos <| le_of_lt <| negSucc_lt_zero _
#align int.abs_eq_nat_abs Int.abs_eq_natAbs
@[simp, norm_cast] lemma natCast_natAbs (n : ℤ) : (n.natAbs : ℤ) = |n| := n.abs_eq_natAbs.symm
#align int.coe_nat_abs Int.natCast_natAbs
theorem natAbs_abs (a : ℤ) : natAbs |a| = natAbs a := by rw [abs_eq_natAbs]; rfl
#align int.nat_abs_abs Int.natAbs_abs
theorem sign_mul_abs (a : ℤ) : sign a * |a| = a := by
rw [abs_eq_natAbs, sign_mul_natAbs a]
#align int.sign_mul_abs Int.sign_mul_abs
lemma natAbs_le_self_sq (a : ℤ) : (Int.natAbs a : ℤ) ≤ a ^ 2 := by
rw [← Int.natAbs_sq a, sq]
norm_cast
apply Nat.le_mul_self
#align int.abs_le_self_sq Int.natAbs_le_self_sq
alias natAbs_le_self_pow_two := natAbs_le_self_sq
lemma le_self_sq (b : ℤ) : b ≤ b ^ 2 := le_trans le_natAbs (natAbs_le_self_sq _)
#align int.le_self_sq Int.le_self_sq
alias le_self_pow_two := le_self_sq
#align int.le_self_pow_two Int.le_self_pow_two
@[norm_cast] lemma abs_natCast (n : ℕ) : |(n : ℤ)| = n := abs_of_nonneg (natCast_nonneg n)
#align int.abs_coe_nat Int.abs_natCast
theorem natAbs_sub_pos_iff {i j : ℤ} : 0 < natAbs (i - j) ↔ i ≠ j := by
rw [natAbs_pos, ne_eq, sub_eq_zero]
theorem natAbs_sub_ne_zero_iff {i j : ℤ} : natAbs (i - j) ≠ 0 ↔ i ≠ j :=
Nat.ne_zero_iff_zero_lt.trans natAbs_sub_pos_iff
@[simp]
theorem abs_lt_one_iff {a : ℤ} : |a| < 1 ↔ a = 0 := by
rw [← zero_add 1, lt_add_one_iff, abs_nonpos_iff]
#align int.abs_lt_one_iff Int.abs_lt_one_iff
| Mathlib/Algebra/Order/Group/Int.lean | 92 | 93 | theorem abs_le_one_iff {a : ℤ} : |a| ≤ 1 ↔ a = 0 ∨ a = 1 ∨ a = -1 := by |
rw [le_iff_lt_or_eq, abs_lt_one_iff, abs_eq Int.one_nonneg]
|
import Mathlib.Analysis.Calculus.ContDiff.Basic
import Mathlib.Analysis.NormedSpace.FiniteDimension
#align_import analysis.calculus.bump_function_inner from "leanprover-community/mathlib"@"3bce8d800a6f2b8f63fe1e588fd76a9ff4adcebe"
noncomputable section
open Function Set Filter
open scoped Topology Filter
variable {E X : Type*}
structure ContDiffBump (c : E) where
(rIn rOut : ℝ)
rIn_pos : 0 < rIn
rIn_lt_rOut : rIn < rOut
#align cont_diff_bump ContDiffBump
#align cont_diff_bump.r ContDiffBump.rIn
set_option linter.uppercaseLean3 false in
#align cont_diff_bump.R ContDiffBump.rOut
#align cont_diff_bump.r_pos ContDiffBump.rIn_pos
set_option linter.uppercaseLean3 false in
#align cont_diff_bump.r_lt_R ContDiffBump.rIn_lt_rOut
-- Porting note(#5171): linter not yet ported; was @[nolint has_nonempty_instance]
structure ContDiffBumpBase (E : Type*) [NormedAddCommGroup E] [NormedSpace ℝ E] where
toFun : ℝ → E → ℝ
mem_Icc : ∀ (R : ℝ) (x : E), toFun R x ∈ Icc (0 : ℝ) 1
symmetric : ∀ (R : ℝ) (x : E), toFun R (-x) = toFun R x
smooth : ContDiffOn ℝ ⊤ (uncurry toFun) (Ioi (1 : ℝ) ×ˢ (univ : Set E))
eq_one : ∀ R : ℝ, 1 < R → ∀ x : E, ‖x‖ ≤ 1 → toFun R x = 1
support : ∀ R : ℝ, 1 < R → Function.support (toFun R) = Metric.ball (0 : E) R
#align cont_diff_bump_base ContDiffBumpBase
class HasContDiffBump (E : Type*) [NormedAddCommGroup E] [NormedSpace ℝ E] : Prop where
out : Nonempty (ContDiffBumpBase E)
#align has_cont_diff_bump HasContDiffBump
def someContDiffBumpBase (E : Type*) [NormedAddCommGroup E] [NormedSpace ℝ E]
[hb : HasContDiffBump E] : ContDiffBumpBase E :=
Nonempty.some hb.out
#align some_cont_diff_bump_base someContDiffBumpBase
namespace ContDiffBump
theorem rOut_pos {c : E} (f : ContDiffBump c) : 0 < f.rOut :=
f.rIn_pos.trans f.rIn_lt_rOut
set_option linter.uppercaseLean3 false in
#align cont_diff_bump.R_pos ContDiffBump.rOut_pos
theorem one_lt_rOut_div_rIn {c : E} (f : ContDiffBump c) : 1 < f.rOut / f.rIn := by
rw [one_lt_div f.rIn_pos]
exact f.rIn_lt_rOut
set_option linter.uppercaseLean3 false in
#align cont_diff_bump.one_lt_R_div_r ContDiffBump.one_lt_rOut_div_rIn
instance (c : E) : Inhabited (ContDiffBump c) :=
⟨⟨1, 2, zero_lt_one, one_lt_two⟩⟩
variable [NormedAddCommGroup E] [NormedSpace ℝ E] [NormedAddCommGroup X] [NormedSpace ℝ X]
[HasContDiffBump E] {c : E} (f : ContDiffBump c) {x : E} {n : ℕ∞}
@[coe] def toFun {c : E} (f : ContDiffBump c) : E → ℝ :=
(someContDiffBumpBase E).toFun (f.rOut / f.rIn) ∘ fun x ↦ (f.rIn⁻¹ • (x - c))
#align cont_diff_bump.to_fun ContDiffBump.toFun
instance : CoeFun (ContDiffBump c) fun _ => E → ℝ :=
⟨toFun⟩
protected theorem apply (x : E) :
f x = (someContDiffBumpBase E).toFun (f.rOut / f.rIn) (f.rIn⁻¹ • (x - c)) :=
rfl
#align cont_diff_bump.def ContDiffBump.apply
protected theorem sub (x : E) : f (c - x) = f (c + x) := by
simp [f.apply, ContDiffBumpBase.symmetric]
#align cont_diff_bump.sub ContDiffBump.sub
protected theorem neg (f : ContDiffBump (0 : E)) (x : E) : f (-x) = f x := by
simp_rw [← zero_sub, f.sub, zero_add]
#align cont_diff_bump.neg ContDiffBump.neg
open Metric
theorem one_of_mem_closedBall (hx : x ∈ closedBall c f.rIn) : f x = 1 := by
apply ContDiffBumpBase.eq_one _ _ f.one_lt_rOut_div_rIn
simpa only [norm_smul, Real.norm_eq_abs, abs_inv, abs_of_nonneg f.rIn_pos.le, ← div_eq_inv_mul,
div_le_one f.rIn_pos] using mem_closedBall_iff_norm.1 hx
#align cont_diff_bump.one_of_mem_closed_ball ContDiffBump.one_of_mem_closedBall
theorem nonneg : 0 ≤ f x :=
(ContDiffBumpBase.mem_Icc (someContDiffBumpBase E) _ _).1
#align cont_diff_bump.nonneg ContDiffBump.nonneg
theorem nonneg' (x : E) : 0 ≤ f x := f.nonneg
#align cont_diff_bump.nonneg' ContDiffBump.nonneg'
theorem le_one : f x ≤ 1 :=
(ContDiffBumpBase.mem_Icc (someContDiffBumpBase E) _ _).2
#align cont_diff_bump.le_one ContDiffBump.le_one
theorem support_eq : Function.support f = Metric.ball c f.rOut := by
simp only [toFun, support_comp_eq_preimage, ContDiffBumpBase.support _ _ f.one_lt_rOut_div_rIn]
ext x
simp only [mem_ball_iff_norm, sub_zero, norm_smul, mem_preimage, Real.norm_eq_abs, abs_inv,
abs_of_pos f.rIn_pos, ← div_eq_inv_mul, div_lt_div_right f.rIn_pos]
#align cont_diff_bump.support_eq ContDiffBump.support_eq
theorem tsupport_eq : tsupport f = closedBall c f.rOut := by
simp_rw [tsupport, f.support_eq, closure_ball _ f.rOut_pos.ne']
#align cont_diff_bump.tsupport_eq ContDiffBump.tsupport_eq
theorem pos_of_mem_ball (hx : x ∈ ball c f.rOut) : 0 < f x :=
f.nonneg.lt_of_ne' <| by rwa [← support_eq, mem_support] at hx
#align cont_diff_bump.pos_of_mem_ball ContDiffBump.pos_of_mem_ball
theorem zero_of_le_dist (hx : f.rOut ≤ dist x c) : f x = 0 := by
rwa [← nmem_support, support_eq, mem_ball, not_lt]
#align cont_diff_bump.zero_of_le_dist ContDiffBump.zero_of_le_dist
protected theorem hasCompactSupport [FiniteDimensional ℝ E] : HasCompactSupport f := by
simp_rw [HasCompactSupport, f.tsupport_eq, isCompact_closedBall]
#align cont_diff_bump.has_compact_support ContDiffBump.hasCompactSupport
theorem eventuallyEq_one_of_mem_ball (h : x ∈ ball c f.rIn) : f =ᶠ[𝓝 x] 1 :=
mem_of_superset (closedBall_mem_nhds_of_mem h) fun _ ↦ f.one_of_mem_closedBall
#align cont_diff_bump.eventually_eq_one_of_mem_ball ContDiffBump.eventuallyEq_one_of_mem_ball
theorem eventuallyEq_one : f =ᶠ[𝓝 c] 1 :=
f.eventuallyEq_one_of_mem_ball (mem_ball_self f.rIn_pos)
#align cont_diff_bump.eventually_eq_one ContDiffBump.eventuallyEq_one
-- Porting note (#10756): new lemma
protected theorem _root_.ContDiffWithinAt.contDiffBump {c g : X → E} {s : Set X}
{f : ∀ x, ContDiffBump (c x)} {x : X} (hc : ContDiffWithinAt ℝ n c s x)
(hr : ContDiffWithinAt ℝ n (fun x => (f x).rIn) s x)
(hR : ContDiffWithinAt ℝ n (fun x => (f x).rOut) s x)
(hg : ContDiffWithinAt ℝ n g s x) :
ContDiffWithinAt ℝ n (fun x => f x (g x)) s x := by
change ContDiffWithinAt ℝ n (uncurry (someContDiffBumpBase E).toFun ∘ fun x : X =>
((f x).rOut / (f x).rIn, (f x).rIn⁻¹ • (g x - c x))) s x
refine (((someContDiffBumpBase E).smooth.contDiffAt ?_).of_le le_top).comp_contDiffWithinAt x ?_
· exact prod_mem_nhds (Ioi_mem_nhds (f x).one_lt_rOut_div_rIn) univ_mem
· exact (hR.div hr (f x).rIn_pos.ne').prod ((hr.inv (f x).rIn_pos.ne').smul (hg.sub hc))
protected nonrec theorem _root_.ContDiffAt.contDiffBump {c g : X → E} {f : ∀ x, ContDiffBump (c x)}
{x : X} (hc : ContDiffAt ℝ n c x) (hr : ContDiffAt ℝ n (fun x => (f x).rIn) x)
(hR : ContDiffAt ℝ n (fun x => (f x).rOut) x) (hg : ContDiffAt ℝ n g x) :
ContDiffAt ℝ n (fun x => f x (g x)) x :=
hc.contDiffBump hr hR hg
#align cont_diff_at.cont_diff_bump ContDiffAt.contDiffBump
| Mathlib/Analysis/Calculus/BumpFunction/Basic.lean | 225 | 230 | theorem _root_.ContDiff.contDiffBump {c g : X → E} {f : ∀ x, ContDiffBump (c x)}
(hc : ContDiff ℝ n c) (hr : ContDiff ℝ n fun x => (f x).rIn)
(hR : ContDiff ℝ n fun x => (f x).rOut) (hg : ContDiff ℝ n g) :
ContDiff ℝ n fun x => f x (g x) := by |
rw [contDiff_iff_contDiffAt] at *
exact fun x => (hc x).contDiffBump (hr x) (hR x) (hg x)
|
import Mathlib.Algebra.CharZero.Defs
import Mathlib.Algebra.Group.Pi.Basic
import Mathlib.Algebra.Group.Units
import Mathlib.Algebra.GroupWithZero.NeZero
import Mathlib.Algebra.Order.Group.Defs
import Mathlib.Algebra.Order.GroupWithZero.Unbundled
import Mathlib.Algebra.Order.Monoid.Canonical.Defs
import Mathlib.Algebra.Order.Monoid.NatCast
import Mathlib.Algebra.Order.Monoid.Unbundled.MinMax
import Mathlib.Algebra.Ring.Defs
import Mathlib.Tactic.Tauto
#align_import algebra.order.ring.char_zero from "leanprover-community/mathlib"@"655994e298904d7e5bbd1e18c95defd7b543eb94"
#align_import algebra.order.ring.defs from "leanprover-community/mathlib"@"44e29dbcff83ba7114a464d592b8c3743987c1e5"
open Function
universe u
variable {α : Type u} {β : Type*}
theorem add_one_le_two_mul [LE α] [Semiring α] [CovariantClass α α (· + ·) (· ≤ ·)] {a : α}
(a1 : 1 ≤ a) : a + 1 ≤ 2 * a :=
calc
a + 1 ≤ a + a := add_le_add_left a1 a
_ = 2 * a := (two_mul _).symm
#align add_one_le_two_mul add_one_le_two_mul
class OrderedSemiring (α : Type u) extends Semiring α, OrderedAddCommMonoid α where
protected zero_le_one : (0 : α) ≤ 1
protected mul_le_mul_of_nonneg_left : ∀ a b c : α, a ≤ b → 0 ≤ c → c * a ≤ c * b
protected mul_le_mul_of_nonneg_right : ∀ a b c : α, a ≤ b → 0 ≤ c → a * c ≤ b * c
#align ordered_semiring OrderedSemiring
class OrderedCommSemiring (α : Type u) extends OrderedSemiring α, CommSemiring α where
mul_le_mul_of_nonneg_right a b c ha hc :=
-- parentheses ensure this generates an `optParam` rather than an `autoParam`
(by simpa only [mul_comm] using mul_le_mul_of_nonneg_left a b c ha hc)
#align ordered_comm_semiring OrderedCommSemiring
class OrderedRing (α : Type u) extends Ring α, OrderedAddCommGroup α where
protected zero_le_one : 0 ≤ (1 : α)
protected mul_nonneg : ∀ a b : α, 0 ≤ a → 0 ≤ b → 0 ≤ a * b
#align ordered_ring OrderedRing
class OrderedCommRing (α : Type u) extends OrderedRing α, CommRing α
#align ordered_comm_ring OrderedCommRing
class StrictOrderedSemiring (α : Type u) extends Semiring α, OrderedCancelAddCommMonoid α,
Nontrivial α where
protected zero_le_one : (0 : α) ≤ 1
protected mul_lt_mul_of_pos_left : ∀ a b c : α, a < b → 0 < c → c * a < c * b
protected mul_lt_mul_of_pos_right : ∀ a b c : α, a < b → 0 < c → a * c < b * c
#align strict_ordered_semiring StrictOrderedSemiring
class StrictOrderedCommSemiring (α : Type u) extends StrictOrderedSemiring α, CommSemiring α
#align strict_ordered_comm_semiring StrictOrderedCommSemiring
class StrictOrderedRing (α : Type u) extends Ring α, OrderedAddCommGroup α, Nontrivial α where
protected zero_le_one : 0 ≤ (1 : α)
protected mul_pos : ∀ a b : α, 0 < a → 0 < b → 0 < a * b
#align strict_ordered_ring StrictOrderedRing
class StrictOrderedCommRing (α : Type*) extends StrictOrderedRing α, CommRing α
#align strict_ordered_comm_ring StrictOrderedCommRing
class LinearOrderedSemiring (α : Type u) extends StrictOrderedSemiring α,
LinearOrderedAddCommMonoid α
#align linear_ordered_semiring LinearOrderedSemiring
class LinearOrderedCommSemiring (α : Type*) extends StrictOrderedCommSemiring α,
LinearOrderedSemiring α
#align linear_ordered_comm_semiring LinearOrderedCommSemiring
class LinearOrderedRing (α : Type u) extends StrictOrderedRing α, LinearOrder α
#align linear_ordered_ring LinearOrderedRing
class LinearOrderedCommRing (α : Type u) extends LinearOrderedRing α, CommMonoid α
#align linear_ordered_comm_ring LinearOrderedCommRing
section OrderedSemiring
variable [OrderedSemiring α] {a b c d : α}
-- see Note [lower instance priority]
instance (priority := 100) OrderedSemiring.zeroLEOneClass : ZeroLEOneClass α :=
{ ‹OrderedSemiring α› with }
#align ordered_semiring.zero_le_one_class OrderedSemiring.zeroLEOneClass
-- see Note [lower instance priority]
instance (priority := 200) OrderedSemiring.toPosMulMono : PosMulMono α :=
⟨fun x _ _ h => OrderedSemiring.mul_le_mul_of_nonneg_left _ _ _ h x.2⟩
#align ordered_semiring.to_pos_mul_mono OrderedSemiring.toPosMulMono
-- see Note [lower instance priority]
instance (priority := 200) OrderedSemiring.toMulPosMono : MulPosMono α :=
⟨fun x _ _ h => OrderedSemiring.mul_le_mul_of_nonneg_right _ _ _ h x.2⟩
#align ordered_semiring.to_mul_pos_mono OrderedSemiring.toMulPosMono
set_option linter.deprecated false in
theorem bit1_mono : Monotone (bit1 : α → α) := fun _ _ h => add_le_add_right (bit0_mono h) _
#align bit1_mono bit1_mono
@[simp]
theorem pow_nonneg (H : 0 ≤ a) : ∀ n : ℕ, 0 ≤ a ^ n
| 0 => by
rw [pow_zero]
exact zero_le_one
| n + 1 => by
rw [pow_succ]
exact mul_nonneg (pow_nonneg H _) H
#align pow_nonneg pow_nonneg
lemma pow_le_pow_of_le_one (ha₀ : 0 ≤ a) (ha₁ : a ≤ 1) : ∀ {m n : ℕ}, m ≤ n → a ^ n ≤ a ^ m
| _, _, Nat.le.refl => le_rfl
| _, _, Nat.le.step h => by
rw [pow_succ']
exact (mul_le_of_le_one_left (pow_nonneg ha₀ _) ha₁).trans $ pow_le_pow_of_le_one ha₀ ha₁ h
#align pow_le_pow_of_le_one pow_le_pow_of_le_one
lemma pow_le_of_le_one (h₀ : 0 ≤ a) (h₁ : a ≤ 1) {n : ℕ} (hn : n ≠ 0) : a ^ n ≤ a :=
(pow_one a).subst (pow_le_pow_of_le_one h₀ h₁ (Nat.pos_of_ne_zero hn))
#align pow_le_of_le_one pow_le_of_le_one
lemma sq_le (h₀ : 0 ≤ a) (h₁ : a ≤ 1) : a ^ 2 ≤ a := pow_le_of_le_one h₀ h₁ two_ne_zero
#align sq_le sq_le
-- Porting note: it's unfortunate we need to write `(@one_le_two α)` here.
theorem add_le_mul_two_add (a2 : 2 ≤ a) (b0 : 0 ≤ b) : a + (2 + b) ≤ a * (2 + b) :=
calc
a + (2 + b) ≤ a + (a + a * b) :=
add_le_add_left (add_le_add a2 <| le_mul_of_one_le_left b0 <| (@one_le_two α).trans a2) a
_ ≤ a * (2 + b) := by rw [mul_add, mul_two, add_assoc]
#align add_le_mul_two_add add_le_mul_two_add
theorem one_le_mul_of_one_le_of_one_le (ha : 1 ≤ a) (hb : 1 ≤ b) : (1 : α) ≤ a * b :=
Left.one_le_mul_of_le_of_le ha hb <| zero_le_one.trans ha
#align one_le_mul_of_one_le_of_one_le one_le_mul_of_one_le_of_one_le
section
set_option linter.deprecated false
theorem bit1_pos [Nontrivial α] (h : 0 ≤ a) : 0 < bit1 a :=
zero_lt_one.trans_le <| bit1_zero.symm.trans_le <| bit1_mono h
#align bit1_pos bit1_pos
theorem bit1_pos' (h : 0 < a) : 0 < bit1 a := by
nontriviality
exact bit1_pos h.le
#align bit1_pos' bit1_pos'
end
theorem mul_le_one (ha : a ≤ 1) (hb' : 0 ≤ b) (hb : b ≤ 1) : a * b ≤ 1 :=
one_mul (1 : α) ▸ mul_le_mul ha hb hb' zero_le_one
#align mul_le_one mul_le_one
theorem one_lt_mul_of_le_of_lt (ha : 1 ≤ a) (hb : 1 < b) : 1 < a * b :=
hb.trans_le <| le_mul_of_one_le_left (zero_le_one.trans hb.le) ha
#align one_lt_mul_of_le_of_lt one_lt_mul_of_le_of_lt
theorem one_lt_mul_of_lt_of_le (ha : 1 < a) (hb : 1 ≤ b) : 1 < a * b :=
ha.trans_le <| le_mul_of_one_le_right (zero_le_one.trans ha.le) hb
#align one_lt_mul_of_lt_of_le one_lt_mul_of_lt_of_le
alias one_lt_mul := one_lt_mul_of_le_of_lt
#align one_lt_mul one_lt_mul
theorem mul_lt_one_of_nonneg_of_lt_one_left (ha₀ : 0 ≤ a) (ha : a < 1) (hb : b ≤ 1) : a * b < 1 :=
(mul_le_of_le_one_right ha₀ hb).trans_lt ha
#align mul_lt_one_of_nonneg_of_lt_one_left mul_lt_one_of_nonneg_of_lt_one_left
theorem mul_lt_one_of_nonneg_of_lt_one_right (ha : a ≤ 1) (hb₀ : 0 ≤ b) (hb : b < 1) : a * b < 1 :=
(mul_le_of_le_one_left hb₀ ha).trans_lt hb
#align mul_lt_one_of_nonneg_of_lt_one_right mul_lt_one_of_nonneg_of_lt_one_right
variable [ExistsAddOfLE α] [ContravariantClass α α (swap (· + ·)) (· ≤ ·)]
theorem mul_le_mul_of_nonpos_left (h : b ≤ a) (hc : c ≤ 0) : c * a ≤ c * b := by
obtain ⟨d, hcd⟩ := exists_add_of_le hc
refine le_of_add_le_add_right (a := d * b + d * a) ?_
calc
_ = d * b := by rw [add_left_comm, ← add_mul, ← hcd, zero_mul, add_zero]
_ ≤ d * a := mul_le_mul_of_nonneg_left h <| hcd.trans_le <| add_le_of_nonpos_left hc
_ = _ := by rw [← add_assoc, ← add_mul, ← hcd, zero_mul, zero_add]
#align mul_le_mul_of_nonpos_left mul_le_mul_of_nonpos_left
theorem mul_le_mul_of_nonpos_right (h : b ≤ a) (hc : c ≤ 0) : a * c ≤ b * c := by
obtain ⟨d, hcd⟩ := exists_add_of_le hc
refine le_of_add_le_add_right (a := b * d + a * d) ?_
calc
_ = b * d := by rw [add_left_comm, ← mul_add, ← hcd, mul_zero, add_zero]
_ ≤ a * d := mul_le_mul_of_nonneg_right h <| hcd.trans_le <| add_le_of_nonpos_left hc
_ = _ := by rw [← add_assoc, ← mul_add, ← hcd, mul_zero, zero_add]
#align mul_le_mul_of_nonpos_right mul_le_mul_of_nonpos_right
theorem mul_nonneg_of_nonpos_of_nonpos (ha : a ≤ 0) (hb : b ≤ 0) : 0 ≤ a * b := by
simpa only [zero_mul] using mul_le_mul_of_nonpos_right ha hb
#align mul_nonneg_of_nonpos_of_nonpos mul_nonneg_of_nonpos_of_nonpos
theorem mul_le_mul_of_nonneg_of_nonpos (hca : c ≤ a) (hbd : b ≤ d) (hc : 0 ≤ c) (hb : b ≤ 0) :
a * b ≤ c * d :=
(mul_le_mul_of_nonpos_right hca hb).trans <| mul_le_mul_of_nonneg_left hbd hc
#align mul_le_mul_of_nonneg_of_nonpos mul_le_mul_of_nonneg_of_nonpos
theorem mul_le_mul_of_nonneg_of_nonpos' (hca : c ≤ a) (hbd : b ≤ d) (ha : 0 ≤ a) (hd : d ≤ 0) :
a * b ≤ c * d :=
(mul_le_mul_of_nonneg_left hbd ha).trans <| mul_le_mul_of_nonpos_right hca hd
#align mul_le_mul_of_nonneg_of_nonpos' mul_le_mul_of_nonneg_of_nonpos'
theorem mul_le_mul_of_nonpos_of_nonneg (hac : a ≤ c) (hdb : d ≤ b) (hc : c ≤ 0) (hb : 0 ≤ b) :
a * b ≤ c * d :=
(mul_le_mul_of_nonneg_right hac hb).trans <| mul_le_mul_of_nonpos_left hdb hc
#align mul_le_mul_of_nonpos_of_nonneg mul_le_mul_of_nonpos_of_nonneg
theorem mul_le_mul_of_nonpos_of_nonneg' (hca : c ≤ a) (hbd : b ≤ d) (ha : 0 ≤ a) (hd : d ≤ 0) :
a * b ≤ c * d :=
(mul_le_mul_of_nonneg_left hbd ha).trans <| mul_le_mul_of_nonpos_right hca hd
#align mul_le_mul_of_nonpos_of_nonneg' mul_le_mul_of_nonpos_of_nonneg'
theorem mul_le_mul_of_nonpos_of_nonpos (hca : c ≤ a) (hdb : d ≤ b) (hc : c ≤ 0) (hb : b ≤ 0) :
a * b ≤ c * d :=
(mul_le_mul_of_nonpos_right hca hb).trans <| mul_le_mul_of_nonpos_left hdb hc
#align mul_le_mul_of_nonpos_of_nonpos mul_le_mul_of_nonpos_of_nonpos
theorem mul_le_mul_of_nonpos_of_nonpos' (hca : c ≤ a) (hdb : d ≤ b) (ha : a ≤ 0) (hd : d ≤ 0) :
a * b ≤ c * d :=
(mul_le_mul_of_nonpos_left hdb ha).trans <| mul_le_mul_of_nonpos_right hca hd
#align mul_le_mul_of_nonpos_of_nonpos' mul_le_mul_of_nonpos_of_nonpos'
theorem le_mul_of_le_one_left (hb : b ≤ 0) (h : a ≤ 1) : b ≤ a * b := by
simpa only [one_mul] using mul_le_mul_of_nonpos_right h hb
#align le_mul_of_le_one_left le_mul_of_le_one_left
theorem mul_le_of_one_le_left (hb : b ≤ 0) (h : 1 ≤ a) : a * b ≤ b := by
simpa only [one_mul] using mul_le_mul_of_nonpos_right h hb
#align mul_le_of_one_le_left mul_le_of_one_le_left
| Mathlib/Algebra/Order/Ring/Defs.lean | 414 | 415 | theorem le_mul_of_le_one_right (ha : a ≤ 0) (h : b ≤ 1) : a ≤ a * b := by |
simpa only [mul_one] using mul_le_mul_of_nonpos_left h ha
|
import Mathlib.Topology.Gluing
import Mathlib.Geometry.RingedSpace.OpenImmersion
import Mathlib.Geometry.RingedSpace.LocallyRingedSpace.HasColimits
#align_import algebraic_geometry.presheafed_space.gluing from "leanprover-community/mathlib"@"533f62f4dd62a5aad24a04326e6e787c8f7e98b1"
set_option linter.uppercaseLean3 false
noncomputable section
open TopologicalSpace CategoryTheory Opposite
open CategoryTheory.Limits AlgebraicGeometry.PresheafedSpace
open CategoryTheory.GlueData
namespace AlgebraicGeometry
universe v u
variable (C : Type u) [Category.{v} C]
namespace PresheafedSpace
-- Porting note(#5171): this linter isn't ported yet.
-- @[nolint has_nonempty_instance]
structure GlueData extends GlueData (PresheafedSpace.{u, v, v} C) where
f_open : ∀ i j, IsOpenImmersion (f i j)
#align algebraic_geometry.PresheafedSpace.glue_data AlgebraicGeometry.PresheafedSpace.GlueData
attribute [instance] GlueData.f_open
namespace GlueData
variable {C}
variable (D : GlueData.{v, u} C)
local notation "𝖣" => D.toGlueData
local notation "π₁ " i ", " j ", " k => @pullback.fst _ _ _ _ _ (D.f i j) (D.f i k) _
local notation "π₂ " i ", " j ", " k => @pullback.snd _ _ _ _ _ (D.f i j) (D.f i k) _
set_option quotPrecheck false
local notation "π₁⁻¹ " i ", " j ", " k =>
(PresheafedSpace.IsOpenImmersion.pullbackFstOfRight (D.f i j) (D.f i k)).invApp
set_option quotPrecheck false
local notation "π₂⁻¹ " i ", " j ", " k =>
(PresheafedSpace.IsOpenImmersion.pullbackSndOfLeft (D.f i j) (D.f i k)).invApp
abbrev toTopGlueData : TopCat.GlueData :=
{ f_open := fun i j => (D.f_open i j).base_open
toGlueData := 𝖣.mapGlueData (forget C) }
#align algebraic_geometry.PresheafedSpace.glue_data.to_Top_glue_data AlgebraicGeometry.PresheafedSpace.GlueData.toTopGlueData
theorem ι_openEmbedding [HasLimits C] (i : D.J) : OpenEmbedding (𝖣.ι i).base := by
rw [← show _ = (𝖣.ι i).base from 𝖣.ι_gluedIso_inv (PresheafedSpace.forget _) _]
-- Porting note: added this erewrite
erw [coe_comp]
refine
OpenEmbedding.comp
(TopCat.homeoOfIso (𝖣.gluedIso (PresheafedSpace.forget _)).symm).openEmbedding
(D.toTopGlueData.ι_openEmbedding i)
#align algebraic_geometry.PresheafedSpace.glue_data.ι_open_embedding AlgebraicGeometry.PresheafedSpace.GlueData.ι_openEmbedding
theorem pullback_base (i j k : D.J) (S : Set (D.V (i, j)).carrier) :
(π₂ i, j, k) '' ((π₁ i, j, k) ⁻¹' S) = D.f i k ⁻¹' (D.f i j '' S) := by
have eq₁ : _ = (π₁ i, j, k).base := PreservesPullback.iso_hom_fst (forget C) _ _
have eq₂ : _ = (π₂ i, j, k).base := PreservesPullback.iso_hom_snd (forget C) _ _
rw [← eq₁, ← eq₂]
-- Porting note: `rw` to `erw` on `coe_comp`
erw [coe_comp]
rw [Set.image_comp]
-- Porting note: `rw` to `erw` on `coe_comp`
erw [coe_comp]
erw [Set.preimage_comp, Set.image_preimage_eq, TopCat.pullback_snd_image_fst_preimage]
-- now `erw` after #13170
· rfl
erw [← TopCat.epi_iff_surjective] -- now `erw` after #13170
infer_instance
#align algebraic_geometry.PresheafedSpace.glue_data.pullback_base AlgebraicGeometry.PresheafedSpace.GlueData.pullback_base
@[simp, reassoc]
theorem f_invApp_f_app (i j k : D.J) (U : Opens (D.V (i, j)).carrier) :
(D.f_open i j).invApp U ≫ (D.f i k).c.app _ =
(π₁ i, j, k).c.app (op U) ≫
(π₂⁻¹ i, j, k) (unop _) ≫
(D.V _).presheaf.map
(eqToHom
(by
delta IsOpenImmersion.openFunctor
dsimp only [Functor.op, IsOpenMap.functor, Opens.map, unop_op]
congr
apply pullback_base)) := by
have := PresheafedSpace.congr_app (@pullback.condition _ _ _ _ _ (D.f i j) (D.f i k) _)
dsimp only [comp_c_app] at this
rw [← cancel_epi (inv ((D.f_open i j).invApp U)), IsIso.inv_hom_id_assoc,
IsOpenImmersion.inv_invApp]
simp_rw [Category.assoc]
erw [(π₁ i, j, k).c.naturality_assoc, reassoc_of% this, ← Functor.map_comp_assoc,
IsOpenImmersion.inv_naturality_assoc, IsOpenImmersion.app_invApp_assoc, ←
(D.V (i, k)).presheaf.map_comp, ← (D.V (i, k)).presheaf.map_comp]
-- Porting note: need to provide an explicit argument, otherwise Lean does not know which
-- category we are talking about
convert (Category.comp_id ((f D.toGlueData i k).c.app _)).symm
erw [(D.V (i, k)).presheaf.map_id]
rfl
#align algebraic_geometry.PresheafedSpace.glue_data.f_inv_app_f_app AlgebraicGeometry.PresheafedSpace.GlueData.f_invApp_f_app
set_option backward.isDefEq.lazyWhnfCore false in -- See https://github.com/leanprover-community/mathlib4/issues/12534
theorem snd_invApp_t_app' (i j k : D.J) (U : Opens (pullback (D.f i j) (D.f i k)).carrier) :
∃ eq,
(π₂⁻¹ i, j, k) U ≫ (D.t k i).c.app _ ≫ (D.V (k, i)).presheaf.map (eqToHom eq) =
(D.t' k i j).c.app _ ≫ (π₁⁻¹ k, j, i) (unop _) := by
fconstructor
-- Porting note: I don't know what the magic was in Lean3 proof, it just skipped the proof of `eq`
· delta IsOpenImmersion.openFunctor
dsimp only [Functor.op, Opens.map, IsOpenMap.functor, unop_op, Opens.coe_mk]
congr
have := (𝖣.t_fac k i j).symm
rw [← IsIso.inv_comp_eq] at this
replace this := (congr_arg ((PresheafedSpace.Hom.base ·)) this).symm
replace this := congr_arg (ContinuousMap.toFun ·) this
dsimp at this
-- This used to be `rw`, but we need `erw` after leanprover/lean4#2644
erw [coe_comp, coe_comp] at this
-- This used to be `rw`, but we need `erw` after leanprover/lean4#2644
erw [this, Set.image_comp, Set.image_comp, Set.preimage_image_eq]
swap
· refine Function.HasLeftInverse.injective ⟨(D.t i k).base, fun x => ?_⟩
erw [← comp_apply, ← comp_base, D.t_inv, id_base, id_apply] -- now `erw` after #13170
refine congr_arg (_ '' ·) ?_
refine congr_fun ?_ _
refine Set.image_eq_preimage_of_inverse ?_ ?_
· intro x
erw [← comp_apply, ← comp_base, IsIso.inv_hom_id, id_base, id_apply] -- now `erw` after #13170
· intro x
erw [← comp_apply, ← comp_base, IsIso.hom_inv_id, id_base, id_apply] -- now `erw` after #13170
· rw [← IsIso.eq_inv_comp, IsOpenImmersion.inv_invApp, Category.assoc,
(D.t' k i j).c.naturality_assoc]
simp_rw [← Category.assoc]
erw [← comp_c_app]
rw [congr_app (D.t_fac k i j), comp_c_app]
simp_rw [Category.assoc]
erw [IsOpenImmersion.inv_naturality, IsOpenImmersion.inv_naturality_assoc,
IsOpenImmersion.app_inv_app'_assoc]
· simp_rw [← (𝖣.V (k, i)).presheaf.map_comp, eqToHom_map (Functor.op _), eqToHom_op,
eqToHom_trans]
rintro x ⟨y, -, eq⟩
replace eq := ConcreteCategory.congr_arg (𝖣.t i k).base eq
change ((π₂ i, j, k) ≫ D.t i k).base y = (D.t k i ≫ D.t i k).base x at eq
rw [𝖣.t_inv, id_base, TopCat.id_app] at eq
subst eq
use (inv (D.t' k i j)).base y
change (inv (D.t' k i j) ≫ π₁ k, i, j).base y = _
congr 2
rw [IsIso.inv_comp_eq, 𝖣.t_fac_assoc, 𝖣.t_inv, Category.comp_id]
#align algebraic_geometry.PresheafedSpace.glue_data.snd_inv_app_t_app' AlgebraicGeometry.PresheafedSpace.GlueData.snd_invApp_t_app'
set_option backward.isDefEq.lazyWhnfCore false in -- See https://github.com/leanprover-community/mathlib4/issues/12534
@[simp, reassoc]
theorem snd_invApp_t_app (i j k : D.J) (U : Opens (pullback (D.f i j) (D.f i k)).carrier) :
(π₂⁻¹ i, j, k) U ≫ (D.t k i).c.app _ =
(D.t' k i j).c.app _ ≫
(π₁⁻¹ k, j, i) (unop _) ≫
(D.V (k, i)).presheaf.map (eqToHom (D.snd_invApp_t_app' i j k U).choose.symm) := by
have e := (D.snd_invApp_t_app' i j k U).choose_spec
replace e := reassoc_of% e
rw [← e]
simp [eqToHom_map]
#align algebraic_geometry.PresheafedSpace.glue_data.snd_inv_app_t_app AlgebraicGeometry.PresheafedSpace.GlueData.snd_invApp_t_app
variable [HasLimits C]
theorem ι_image_preimage_eq (i j : D.J) (U : Opens (D.U i).carrier) :
(Opens.map (𝖣.ι j).base).obj ((D.ι_openEmbedding i).isOpenMap.functor.obj U) =
(D.f_open j i).openFunctor.obj
((Opens.map (𝖣.t j i).base).obj ((Opens.map (𝖣.f i j).base).obj U)) := by
ext1
dsimp only [Opens.map_coe, IsOpenMap.functor_obj_coe]
rw [← show _ = (𝖣.ι i).base from 𝖣.ι_gluedIso_inv (PresheafedSpace.forget _) i, ←
show _ = (𝖣.ι j).base from 𝖣.ι_gluedIso_inv (PresheafedSpace.forget _) j]
-- Porting note (#11224): change `rw` to `erw` on `coe_comp`
erw [coe_comp, coe_comp, coe_comp]
rw [Set.image_comp, Set.preimage_comp]
erw [Set.preimage_image_eq]
· refine Eq.trans (D.toTopGlueData.preimage_image_eq_image' _ _ _) ?_
dsimp
rw [Set.image_comp]
refine congr_arg (_ '' ·) ?_
rw [Set.eq_preimage_iff_image_eq, ← Set.image_comp]
swap
· exact CategoryTheory.ConcreteCategory.bijective_of_isIso (C := TopCat) _
change (D.t i j ≫ D.t j i).base '' _ = _
rw [𝖣.t_inv]
simp
· erw [← coe_comp, ← TopCat.mono_iff_injective] -- now `erw` after #13170
infer_instance
#align algebraic_geometry.PresheafedSpace.glue_data.ι_image_preimage_eq AlgebraicGeometry.PresheafedSpace.GlueData.ι_image_preimage_eq
def opensImagePreimageMap (i j : D.J) (U : Opens (D.U i).carrier) :
(D.U i).presheaf.obj (op U) ⟶
(D.U j).presheaf.obj (op <|
(Opens.map (𝖣.ι j).base).obj ((D.ι_openEmbedding i).isOpenMap.functor.obj U)) :=
(D.f i j).c.app (op U) ≫
(D.t j i).c.app _ ≫
(D.f_open j i).invApp (unop _) ≫
(𝖣.U j).presheaf.map (eqToHom (D.ι_image_preimage_eq i j U)).op
#align algebraic_geometry.PresheafedSpace.glue_data.opens_image_preimage_map AlgebraicGeometry.PresheafedSpace.GlueData.opensImagePreimageMap
| Mathlib/Geometry/RingedSpace/PresheafedSpace/Gluing.lean | 288 | 303 | theorem opensImagePreimageMap_app' (i j k : D.J) (U : Opens (D.U i).carrier) :
∃ eq,
D.opensImagePreimageMap i j U ≫ (D.f j k).c.app _ =
((π₁ j, i, k) ≫ D.t j i ≫ D.f i j).c.app (op U) ≫
(π₂⁻¹ j, i, k) (unop _) ≫ (D.V (j, k)).presheaf.map (eqToHom eq) := by |
constructor
· delta opensImagePreimageMap
simp_rw [Category.assoc]
rw [(D.f j k).c.naturality, f_invApp_f_app_assoc]
· erw [← (D.V (j, k)).presheaf.map_comp]
· simp_rw [← Category.assoc]
erw [← comp_c_app, ← comp_c_app]
· simp_rw [Category.assoc]
dsimp only [Functor.op, unop_op, Quiver.Hom.unop_op]
rw [eqToHom_map (Opens.map _), eqToHom_op, eqToHom_trans]
congr
|
import Mathlib.FieldTheory.Finiteness
import Mathlib.LinearAlgebra.Dimension.FreeAndStrongRankCondition
import Mathlib.LinearAlgebra.Dimension.DivisionRing
#align_import linear_algebra.finite_dimensional from "leanprover-community/mathlib"@"e95e4f92c8f8da3c7f693c3ec948bcf9b6683f51"
universe u v v' w
open Cardinal Submodule Module Function
abbrev FiniteDimensional (K V : Type*) [DivisionRing K] [AddCommGroup V] [Module K V] :=
Module.Finite K V
#align finite_dimensional FiniteDimensional
variable {K : Type u} {V : Type v}
namespace FiniteDimensional
open IsNoetherian
section
variable [DivisionRing K] [AddCommGroup V] [Module K V]
instance finiteDimensional_finsupp {ι : Type*} [Finite ι] [FiniteDimensional K V] :
FiniteDimensional K (ι →₀ V) :=
Module.Finite.finsupp
#align finite_dimensional_finsupp finiteDimensional_finsupp
end
namespace FiniteDimensional
section DivisionRing
variable [DivisionRing K] [AddCommGroup V] [Module K V] {V₂ : Type v'} [AddCommGroup V₂]
[Module K V₂]
theorem eq_of_le_of_finrank_le {S₁ S₂ : Submodule K V} [FiniteDimensional K S₂] (hle : S₁ ≤ S₂)
(hd : finrank K S₂ ≤ finrank K S₁) : S₁ = S₂ := by
rw [← LinearEquiv.finrank_eq (Submodule.comapSubtypeEquivOfLe hle)] at hd
exact le_antisymm hle (Submodule.comap_subtype_eq_top.1
(eq_top_of_finrank_eq (le_antisymm (comap (Submodule.subtype S₂) S₁).finrank_le hd)))
#align finite_dimensional.eq_of_le_of_finrank_le FiniteDimensional.eq_of_le_of_finrank_le
theorem eq_of_le_of_finrank_eq {S₁ S₂ : Submodule K V} [FiniteDimensional K S₂] (hle : S₁ ≤ S₂)
(hd : finrank K S₁ = finrank K S₂) : S₁ = S₂ :=
eq_of_le_of_finrank_le hle hd.ge
#align finite_dimensional.eq_of_le_of_finrank_eq FiniteDimensional.eq_of_le_of_finrank_eq
section DivisionRing
variable [DivisionRing K] [AddCommGroup V] [Module K V]
section Basis
theorem LinearIndependent.span_eq_top_of_card_eq_finrank' {ι : Type*}
[Fintype ι] [FiniteDimensional K V] {b : ι → V} (lin_ind : LinearIndependent K b)
(card_eq : Fintype.card ι = finrank K V) : span K (Set.range b) = ⊤ := by
by_contra ne_top
rw [← finrank_span_eq_card lin_ind] at card_eq
exact ne_of_lt (Submodule.finrank_lt <| lt_top_iff_ne_top.2 ne_top) card_eq
theorem LinearIndependent.span_eq_top_of_card_eq_finrank {ι : Type*} [Nonempty ι]
[Fintype ι] {b : ι → V} (lin_ind : LinearIndependent K b)
(card_eq : Fintype.card ι = finrank K V) : span K (Set.range b) = ⊤ :=
have : FiniteDimensional K V := .of_finrank_pos <| card_eq ▸ Fintype.card_pos
lin_ind.span_eq_top_of_card_eq_finrank' card_eq
#align span_eq_top_of_linear_independent_of_card_eq_finrank LinearIndependent.span_eq_top_of_card_eq_finrank
@[deprecated (since := "2024-02-14")]
alias span_eq_top_of_linearIndependent_of_card_eq_finrank :=
LinearIndependent.span_eq_top_of_card_eq_finrank
@[simps! repr_apply]
noncomputable def basisOfLinearIndependentOfCardEqFinrank {ι : Type*} [Nonempty ι] [Fintype ι]
{b : ι → V} (lin_ind : LinearIndependent K b) (card_eq : Fintype.card ι = finrank K V) :
Basis ι K V :=
Basis.mk lin_ind <| (lin_ind.span_eq_top_of_card_eq_finrank card_eq).ge
#align basis_of_linear_independent_of_card_eq_finrank basisOfLinearIndependentOfCardEqFinrank
@[simp]
theorem coe_basisOfLinearIndependentOfCardEqFinrank {ι : Type*} [Nonempty ι] [Fintype ι]
{b : ι → V} (lin_ind : LinearIndependent K b) (card_eq : Fintype.card ι = finrank K V) :
⇑(basisOfLinearIndependentOfCardEqFinrank lin_ind card_eq) = b :=
Basis.coe_mk _ _
#align coe_basis_of_linear_independent_of_card_eq_finrank coe_basisOfLinearIndependentOfCardEqFinrank
@[simps! repr_apply]
noncomputable def finsetBasisOfLinearIndependentOfCardEqFinrank {s : Finset V} (hs : s.Nonempty)
(lin_ind : LinearIndependent K ((↑) : s → V)) (card_eq : s.card = finrank K V) : Basis s K V :=
@basisOfLinearIndependentOfCardEqFinrank _ _ _ _ _ _
⟨(⟨hs.choose, hs.choose_spec⟩ : s)⟩ _ _ lin_ind (_root_.trans (Fintype.card_coe _) card_eq)
#align finset_basis_of_linear_independent_of_card_eq_finrank finsetBasisOfLinearIndependentOfCardEqFinrank
@[simp]
| Mathlib/LinearAlgebra/FiniteDimensional.lean | 1,001 | 1,006 | theorem coe_finsetBasisOfLinearIndependentOfCardEqFinrank {s : Finset V} (hs : s.Nonempty)
(lin_ind : LinearIndependent K ((↑) : s → V)) (card_eq : s.card = finrank K V) :
⇑(finsetBasisOfLinearIndependentOfCardEqFinrank hs lin_ind card_eq) = ((↑) : s → V) := by |
-- Porting note: added to make the next line unify the `_`s
rw [finsetBasisOfLinearIndependentOfCardEqFinrank]
exact Basis.coe_mk _ _
|
import Mathlib.Algebra.GroupWithZero.Divisibility
import Mathlib.Algebra.MonoidAlgebra.Basic
import Mathlib.Data.Finset.Sort
#align_import data.polynomial.basic from "leanprover-community/mathlib"@"949dc57e616a621462062668c9f39e4e17b64b69"
set_option linter.uppercaseLean3 false
noncomputable section
structure Polynomial (R : Type*) [Semiring R] where ofFinsupp ::
toFinsupp : AddMonoidAlgebra R ℕ
#align polynomial Polynomial
#align polynomial.of_finsupp Polynomial.ofFinsupp
#align polynomial.to_finsupp Polynomial.toFinsupp
@[inherit_doc] scoped[Polynomial] notation:9000 R "[X]" => Polynomial R
open AddMonoidAlgebra
open Finsupp hiding single
open Function hiding Commute
open Polynomial
namespace Polynomial
universe u
variable {R : Type u} {a b : R} {m n : ℕ}
section Semiring
variable [Semiring R] {p q : R[X]}
theorem forall_iff_forall_finsupp (P : R[X] → Prop) :
(∀ p, P p) ↔ ∀ q : R[ℕ], P ⟨q⟩ :=
⟨fun h q => h ⟨q⟩, fun h ⟨p⟩ => h p⟩
#align polynomial.forall_iff_forall_finsupp Polynomial.forall_iff_forall_finsupp
theorem exists_iff_exists_finsupp (P : R[X] → Prop) :
(∃ p, P p) ↔ ∃ q : R[ℕ], P ⟨q⟩ :=
⟨fun ⟨⟨p⟩, hp⟩ => ⟨p, hp⟩, fun ⟨q, hq⟩ => ⟨⟨q⟩, hq⟩⟩
#align polynomial.exists_iff_exists_finsupp Polynomial.exists_iff_exists_finsupp
@[simp]
theorem eta (f : R[X]) : Polynomial.ofFinsupp f.toFinsupp = f := by cases f; rfl
#align polynomial.eta Polynomial.eta
theorem ofFinsupp_sum {ι : Type*} (s : Finset ι) (f : ι → R[ℕ]) :
(⟨∑ i ∈ s, f i⟩ : R[X]) = ∑ i ∈ s, ⟨f i⟩ :=
map_sum (toFinsuppIso R).symm f s
#align polynomial.of_finsupp_sum Polynomial.ofFinsupp_sum
theorem toFinsupp_sum {ι : Type*} (s : Finset ι) (f : ι → R[X]) :
(∑ i ∈ s, f i : R[X]).toFinsupp = ∑ i ∈ s, (f i).toFinsupp :=
map_sum (toFinsuppIso R) f s
#align polynomial.to_finsupp_sum Polynomial.toFinsupp_sum
-- @[simp] -- Porting note: The original generated theorem is same to `support_ofFinsupp` and
-- the new generated theorem is different, so this attribute should be
-- removed.
def support : R[X] → Finset ℕ
| ⟨p⟩ => p.support
#align polynomial.support Polynomial.support
@[simp]
theorem support_ofFinsupp (p) : support (⟨p⟩ : R[X]) = p.support := by rw [support]
#align polynomial.support_of_finsupp Polynomial.support_ofFinsupp
theorem support_toFinsupp (p : R[X]) : p.toFinsupp.support = p.support := by rw [support]
@[simp]
theorem support_zero : (0 : R[X]).support = ∅ :=
rfl
#align polynomial.support_zero Polynomial.support_zero
@[simp]
theorem support_eq_empty : p.support = ∅ ↔ p = 0 := by
rcases p with ⟨⟩
simp [support]
#align polynomial.support_eq_empty Polynomial.support_eq_empty
@[simp] lemma support_nonempty : p.support.Nonempty ↔ p ≠ 0 :=
Finset.nonempty_iff_ne_empty.trans support_eq_empty.not
theorem card_support_eq_zero : p.support.card = 0 ↔ p = 0 := by simp
#align polynomial.card_support_eq_zero Polynomial.card_support_eq_zero
def monomial (n : ℕ) : R →ₗ[R] R[X] where
toFun t := ⟨Finsupp.single n t⟩
-- porting note (#10745): was `simp`.
map_add' x y := by simp; rw [ofFinsupp_add]
-- porting note (#10745): was `simp [← ofFinsupp_smul]`.
map_smul' r x := by simp; rw [← ofFinsupp_smul, smul_single']
#align polynomial.monomial Polynomial.monomial
@[simp]
theorem toFinsupp_monomial (n : ℕ) (r : R) : (monomial n r).toFinsupp = Finsupp.single n r := by
simp [monomial]
#align polynomial.to_finsupp_monomial Polynomial.toFinsupp_monomial
@[simp]
theorem ofFinsupp_single (n : ℕ) (r : R) : (⟨Finsupp.single n r⟩ : R[X]) = monomial n r := by
simp [monomial]
#align polynomial.of_finsupp_single Polynomial.ofFinsupp_single
-- @[simp] -- Porting note (#10618): simp can prove this
theorem monomial_zero_right (n : ℕ) : monomial n (0 : R) = 0 :=
(monomial n).map_zero
#align polynomial.monomial_zero_right Polynomial.monomial_zero_right
-- This is not a `simp` lemma as `monomial_zero_left` is more general.
theorem monomial_zero_one : monomial 0 (1 : R) = 1 :=
rfl
#align polynomial.monomial_zero_one Polynomial.monomial_zero_one
-- TODO: can't we just delete this one?
theorem monomial_add (n : ℕ) (r s : R) : monomial n (r + s) = monomial n r + monomial n s :=
(monomial n).map_add _ _
#align polynomial.monomial_add Polynomial.monomial_add
theorem monomial_mul_monomial (n m : ℕ) (r s : R) :
monomial n r * monomial m s = monomial (n + m) (r * s) :=
toFinsupp_injective <| by
simp only [toFinsupp_monomial, toFinsupp_mul, AddMonoidAlgebra.single_mul_single]
#align polynomial.monomial_mul_monomial Polynomial.monomial_mul_monomial
@[simp]
theorem monomial_pow (n : ℕ) (r : R) (k : ℕ) : monomial n r ^ k = monomial (n * k) (r ^ k) := by
induction' k with k ih
· simp [pow_zero, monomial_zero_one]
· simp [pow_succ, ih, monomial_mul_monomial, Nat.succ_eq_add_one, mul_add, add_comm]
#align polynomial.monomial_pow Polynomial.monomial_pow
theorem smul_monomial {S} [SMulZeroClass S R] (a : S) (n : ℕ) (b : R) :
a • monomial n b = monomial n (a • b) :=
toFinsupp_injective <| by simp; rw [smul_single]
#align polynomial.smul_monomial Polynomial.smul_monomial
theorem monomial_injective (n : ℕ) : Function.Injective (monomial n : R → R[X]) :=
(toFinsuppIso R).symm.injective.comp (single_injective n)
#align polynomial.monomial_injective Polynomial.monomial_injective
@[simp]
theorem monomial_eq_zero_iff (t : R) (n : ℕ) : monomial n t = 0 ↔ t = 0 :=
LinearMap.map_eq_zero_iff _ (Polynomial.monomial_injective n)
#align polynomial.monomial_eq_zero_iff Polynomial.monomial_eq_zero_iff
theorem support_add : (p + q).support ⊆ p.support ∪ q.support := by
simpa [support] using Finsupp.support_add
#align polynomial.support_add Polynomial.support_add
def C : R →+* R[X] :=
{ monomial 0 with
map_one' := by simp [monomial_zero_one]
map_mul' := by simp [monomial_mul_monomial]
map_zero' := by simp }
#align polynomial.C Polynomial.C
@[simp]
theorem monomial_zero_left (a : R) : monomial 0 a = C a :=
rfl
#align polynomial.monomial_zero_left Polynomial.monomial_zero_left
@[simp]
theorem toFinsupp_C (a : R) : (C a).toFinsupp = single 0 a :=
rfl
#align polynomial.to_finsupp_C Polynomial.toFinsupp_C
theorem C_0 : C (0 : R) = 0 := by simp
#align polynomial.C_0 Polynomial.C_0
theorem C_1 : C (1 : R) = 1 :=
rfl
#align polynomial.C_1 Polynomial.C_1
theorem C_mul : C (a * b) = C a * C b :=
C.map_mul a b
#align polynomial.C_mul Polynomial.C_mul
theorem C_add : C (a + b) = C a + C b :=
C.map_add a b
#align polynomial.C_add Polynomial.C_add
@[simp]
theorem smul_C {S} [SMulZeroClass S R] (s : S) (r : R) : s • C r = C (s • r) :=
smul_monomial _ _ r
#align polynomial.smul_C Polynomial.smul_C
set_option linter.deprecated false in
-- @[simp] -- Porting note (#10618): simp can prove this
theorem C_bit0 : C (bit0 a) = bit0 (C a) :=
C_add
#align polynomial.C_bit0 Polynomial.C_bit0
set_option linter.deprecated false in
-- @[simp] -- Porting note (#10618): simp can prove this
theorem C_bit1 : C (bit1 a) = bit1 (C a) := by simp [bit1, C_bit0]
#align polynomial.C_bit1 Polynomial.C_bit1
theorem C_pow : C (a ^ n) = C a ^ n :=
C.map_pow a n
#align polynomial.C_pow Polynomial.C_pow
-- @[simp] -- Porting note (#10618): simp can prove this
theorem C_eq_natCast (n : ℕ) : C (n : R) = (n : R[X]) :=
map_natCast C n
#align polynomial.C_eq_nat_cast Polynomial.C_eq_natCast
@[deprecated (since := "2024-04-17")]
alias C_eq_nat_cast := C_eq_natCast
@[simp]
theorem C_mul_monomial : C a * monomial n b = monomial n (a * b) := by
simp only [← monomial_zero_left, monomial_mul_monomial, zero_add]
#align polynomial.C_mul_monomial Polynomial.C_mul_monomial
@[simp]
theorem monomial_mul_C : monomial n a * C b = monomial n (a * b) := by
simp only [← monomial_zero_left, monomial_mul_monomial, add_zero]
#align polynomial.monomial_mul_C Polynomial.monomial_mul_C
def X : R[X] :=
monomial 1 1
#align polynomial.X Polynomial.X
theorem monomial_one_one_eq_X : monomial 1 (1 : R) = X :=
rfl
#align polynomial.monomial_one_one_eq_X Polynomial.monomial_one_one_eq_X
theorem monomial_one_right_eq_X_pow (n : ℕ) : monomial n (1 : R) = X ^ n := by
induction' n with n ih
· simp [monomial_zero_one]
· rw [pow_succ, ← ih, ← monomial_one_one_eq_X, monomial_mul_monomial, mul_one]
#align polynomial.monomial_one_right_eq_X_pow Polynomial.monomial_one_right_eq_X_pow
@[simp]
theorem toFinsupp_X : X.toFinsupp = Finsupp.single 1 (1 : R) :=
rfl
#align polynomial.to_finsupp_X Polynomial.toFinsupp_X
theorem X_mul : X * p = p * X := by
rcases p with ⟨⟩
-- Porting note: `ofFinsupp.injEq` is required.
simp only [X, ← ofFinsupp_single, ← ofFinsupp_mul, LinearMap.coe_mk, ofFinsupp.injEq]
-- Porting note: Was `ext`.
refine Finsupp.ext fun _ => ?_
simp [AddMonoidAlgebra.mul_apply, AddMonoidAlgebra.sum_single_index, add_comm]
#align polynomial.X_mul Polynomial.X_mul
theorem X_pow_mul {n : ℕ} : X ^ n * p = p * X ^ n := by
induction' n with n ih
· simp
· conv_lhs => rw [pow_succ]
rw [mul_assoc, X_mul, ← mul_assoc, ih, mul_assoc, ← pow_succ]
#align polynomial.X_pow_mul Polynomial.X_pow_mul
@[simp]
theorem X_mul_C (r : R) : X * C r = C r * X :=
X_mul
#align polynomial.X_mul_C Polynomial.X_mul_C
@[simp]
theorem X_pow_mul_C (r : R) (n : ℕ) : X ^ n * C r = C r * X ^ n :=
X_pow_mul
#align polynomial.X_pow_mul_C Polynomial.X_pow_mul_C
theorem X_pow_mul_assoc {n : ℕ} : p * X ^ n * q = p * q * X ^ n := by
rw [mul_assoc, X_pow_mul, ← mul_assoc]
#align polynomial.X_pow_mul_assoc Polynomial.X_pow_mul_assoc
@[simp]
theorem X_pow_mul_assoc_C {n : ℕ} (r : R) : p * X ^ n * C r = p * C r * X ^ n :=
X_pow_mul_assoc
#align polynomial.X_pow_mul_assoc_C Polynomial.X_pow_mul_assoc_C
theorem commute_X (p : R[X]) : Commute X p :=
X_mul
#align polynomial.commute_X Polynomial.commute_X
theorem commute_X_pow (p : R[X]) (n : ℕ) : Commute (X ^ n) p :=
X_pow_mul
#align polynomial.commute_X_pow Polynomial.commute_X_pow
@[simp]
theorem monomial_mul_X (n : ℕ) (r : R) : monomial n r * X = monomial (n + 1) r := by
erw [monomial_mul_monomial, mul_one]
#align polynomial.monomial_mul_X Polynomial.monomial_mul_X
@[simp]
theorem monomial_mul_X_pow (n : ℕ) (r : R) (k : ℕ) :
monomial n r * X ^ k = monomial (n + k) r := by
induction' k with k ih
· simp
· simp [ih, pow_succ, ← mul_assoc, add_assoc, Nat.succ_eq_add_one]
#align polynomial.monomial_mul_X_pow Polynomial.monomial_mul_X_pow
@[simp]
theorem X_mul_monomial (n : ℕ) (r : R) : X * monomial n r = monomial (n + 1) r := by
rw [X_mul, monomial_mul_X]
#align polynomial.X_mul_monomial Polynomial.X_mul_monomial
@[simp]
theorem X_pow_mul_monomial (k n : ℕ) (r : R) : X ^ k * monomial n r = monomial (n + k) r := by
rw [X_pow_mul, monomial_mul_X_pow]
#align polynomial.X_pow_mul_monomial Polynomial.X_pow_mul_monomial
-- @[simp] -- Porting note: The original generated theorem is same to `coeff_ofFinsupp` and
-- the new generated theorem is different, so this attribute should be
-- removed.
def coeff : R[X] → ℕ → R
| ⟨p⟩ => p
#align polynomial.coeff Polynomial.coeff
-- Porting note (#10756): new theorem
@[simp]
theorem coeff_ofFinsupp (p) : coeff (⟨p⟩ : R[X]) = p := by rw [coeff]
theorem coeff_injective : Injective (coeff : R[X] → ℕ → R) := by
rintro ⟨p⟩ ⟨q⟩
-- Porting note: `ofFinsupp.injEq` is required.
simp only [coeff, DFunLike.coe_fn_eq, imp_self, ofFinsupp.injEq]
#align polynomial.coeff_injective Polynomial.coeff_injective
@[simp]
theorem coeff_inj : p.coeff = q.coeff ↔ p = q :=
coeff_injective.eq_iff
#align polynomial.coeff_inj Polynomial.coeff_inj
theorem toFinsupp_apply (f : R[X]) (i) : f.toFinsupp i = f.coeff i := by cases f; rfl
#align polynomial.to_finsupp_apply Polynomial.toFinsupp_apply
theorem coeff_monomial : coeff (monomial n a) m = if n = m then a else 0 := by
simp [coeff, Finsupp.single_apply]
#align polynomial.coeff_monomial Polynomial.coeff_monomial
@[simp]
theorem coeff_zero (n : ℕ) : coeff (0 : R[X]) n = 0 :=
rfl
#align polynomial.coeff_zero Polynomial.coeff_zero
theorem coeff_one {n : ℕ} : coeff (1 : R[X]) n = if n = 0 then 1 else 0 := by
simp_rw [eq_comm (a := n) (b := 0)]
exact coeff_monomial
#align polynomial.coeff_one Polynomial.coeff_one
@[simp]
theorem coeff_one_zero : coeff (1 : R[X]) 0 = 1 := by
simp [coeff_one]
#align polynomial.coeff_one_zero Polynomial.coeff_one_zero
@[simp]
theorem coeff_X_one : coeff (X : R[X]) 1 = 1 :=
coeff_monomial
#align polynomial.coeff_X_one Polynomial.coeff_X_one
@[simp]
theorem coeff_X_zero : coeff (X : R[X]) 0 = 0 :=
coeff_monomial
#align polynomial.coeff_X_zero Polynomial.coeff_X_zero
@[simp]
theorem coeff_monomial_succ : coeff (monomial (n + 1) a) 0 = 0 := by simp [coeff_monomial]
#align polynomial.coeff_monomial_succ Polynomial.coeff_monomial_succ
theorem coeff_X : coeff (X : R[X]) n = if 1 = n then 1 else 0 :=
coeff_monomial
#align polynomial.coeff_X Polynomial.coeff_X
theorem coeff_X_of_ne_one {n : ℕ} (hn : n ≠ 1) : coeff (X : R[X]) n = 0 := by
rw [coeff_X, if_neg hn.symm]
#align polynomial.coeff_X_of_ne_one Polynomial.coeff_X_of_ne_one
@[simp]
theorem mem_support_iff : n ∈ p.support ↔ p.coeff n ≠ 0 := by
rcases p with ⟨⟩
simp
#align polynomial.mem_support_iff Polynomial.mem_support_iff
theorem not_mem_support_iff : n ∉ p.support ↔ p.coeff n = 0 := by simp
#align polynomial.not_mem_support_iff Polynomial.not_mem_support_iff
theorem coeff_C : coeff (C a) n = ite (n = 0) a 0 := by
convert coeff_monomial (a := a) (m := n) (n := 0) using 2
simp [eq_comm]
#align polynomial.coeff_C Polynomial.coeff_C
@[simp]
theorem coeff_C_zero : coeff (C a) 0 = a :=
coeff_monomial
#align polynomial.coeff_C_zero Polynomial.coeff_C_zero
theorem coeff_C_ne_zero (h : n ≠ 0) : (C a).coeff n = 0 := by rw [coeff_C, if_neg h]
#align polynomial.coeff_C_ne_zero Polynomial.coeff_C_ne_zero
@[simp]
lemma coeff_C_succ {r : R} {n : ℕ} : coeff (C r) (n + 1) = 0 := by simp [coeff_C]
@[simp]
theorem coeff_natCast_ite : (Nat.cast m : R[X]).coeff n = ite (n = 0) m 0 := by
simp only [← C_eq_natCast, coeff_C, Nat.cast_ite, Nat.cast_zero]
@[deprecated (since := "2024-04-17")]
alias coeff_nat_cast_ite := coeff_natCast_ite
-- See note [no_index around OfNat.ofNat]
@[simp]
theorem coeff_ofNat_zero (a : ℕ) [a.AtLeastTwo] :
coeff (no_index (OfNat.ofNat a : R[X])) 0 = OfNat.ofNat a :=
coeff_monomial
-- See note [no_index around OfNat.ofNat]
@[simp]
theorem coeff_ofNat_succ (a n : ℕ) [h : a.AtLeastTwo] :
coeff (no_index (OfNat.ofNat a : R[X])) (n + 1) = 0 := by
rw [← Nat.cast_eq_ofNat]
simp
theorem C_mul_X_pow_eq_monomial : ∀ {n : ℕ}, C a * X ^ n = monomial n a
| 0 => mul_one _
| n + 1 => by
rw [pow_succ, ← mul_assoc, C_mul_X_pow_eq_monomial, X, monomial_mul_monomial, mul_one]
#align polynomial.C_mul_X_pow_eq_monomial Polynomial.C_mul_X_pow_eq_monomial
@[simp high]
theorem toFinsupp_C_mul_X_pow (a : R) (n : ℕ) :
Polynomial.toFinsupp (C a * X ^ n) = Finsupp.single n a := by
rw [C_mul_X_pow_eq_monomial, toFinsupp_monomial]
#align polynomial.to_finsupp_C_mul_X_pow Polynomial.toFinsupp_C_mul_X_pow
theorem C_mul_X_eq_monomial : C a * X = monomial 1 a := by rw [← C_mul_X_pow_eq_monomial, pow_one]
#align polynomial.C_mul_X_eq_monomial Polynomial.C_mul_X_eq_monomial
@[simp high]
theorem toFinsupp_C_mul_X (a : R) : Polynomial.toFinsupp (C a * X) = Finsupp.single 1 a := by
rw [C_mul_X_eq_monomial, toFinsupp_monomial]
#align polynomial.to_finsupp_C_mul_X Polynomial.toFinsupp_C_mul_X
theorem C_injective : Injective (C : R → R[X]) :=
monomial_injective 0
#align polynomial.C_injective Polynomial.C_injective
@[simp]
theorem C_inj : C a = C b ↔ a = b :=
C_injective.eq_iff
#align polynomial.C_inj Polynomial.C_inj
@[simp]
theorem C_eq_zero : C a = 0 ↔ a = 0 :=
C_injective.eq_iff' (map_zero C)
#align polynomial.C_eq_zero Polynomial.C_eq_zero
theorem C_ne_zero : C a ≠ 0 ↔ a ≠ 0 :=
C_eq_zero.not
#align polynomial.C_ne_zero Polynomial.C_ne_zero
theorem subsingleton_iff_subsingleton : Subsingleton R[X] ↔ Subsingleton R :=
⟨@Injective.subsingleton _ _ _ C_injective, by
intro
infer_instance⟩
#align polynomial.subsingleton_iff_subsingleton Polynomial.subsingleton_iff_subsingleton
theorem Nontrivial.of_polynomial_ne (h : p ≠ q) : Nontrivial R :=
(subsingleton_or_nontrivial R).resolve_left fun _hI => h <| Subsingleton.elim _ _
#align polynomial.nontrivial.of_polynomial_ne Polynomial.Nontrivial.of_polynomial_ne
theorem forall_eq_iff_forall_eq : (∀ f g : R[X], f = g) ↔ ∀ a b : R, a = b := by
simpa only [← subsingleton_iff] using subsingleton_iff_subsingleton
#align polynomial.forall_eq_iff_forall_eq Polynomial.forall_eq_iff_forall_eq
theorem ext_iff {p q : R[X]} : p = q ↔ ∀ n, coeff p n = coeff q n := by
rcases p with ⟨f : ℕ →₀ R⟩
rcases q with ⟨g : ℕ →₀ R⟩
-- porting note (#10745): was `simp [coeff, DFunLike.ext_iff]`
simpa [coeff] using DFunLike.ext_iff (f := f) (g := g)
#align polynomial.ext_iff Polynomial.ext_iff
@[ext]
theorem ext {p q : R[X]} : (∀ n, coeff p n = coeff q n) → p = q :=
ext_iff.2
#align polynomial.ext Polynomial.ext
theorem addSubmonoid_closure_setOf_eq_monomial :
AddSubmonoid.closure { p : R[X] | ∃ n a, p = monomial n a } = ⊤ := by
apply top_unique
rw [← AddSubmonoid.map_equiv_top (toFinsuppIso R).symm.toAddEquiv, ←
Finsupp.add_closure_setOf_eq_single, AddMonoidHom.map_mclosure]
refine AddSubmonoid.closure_mono (Set.image_subset_iff.2 ?_)
rintro _ ⟨n, a, rfl⟩
exact ⟨n, a, Polynomial.ofFinsupp_single _ _⟩
#align polynomial.add_submonoid_closure_set_of_eq_monomial Polynomial.addSubmonoid_closure_setOf_eq_monomial
theorem addHom_ext {M : Type*} [AddMonoid M] {f g : R[X] →+ M}
(h : ∀ n a, f (monomial n a) = g (monomial n a)) : f = g :=
AddMonoidHom.eq_of_eqOn_denseM addSubmonoid_closure_setOf_eq_monomial <| by
rintro p ⟨n, a, rfl⟩
exact h n a
#align polynomial.add_hom_ext Polynomial.addHom_ext
@[ext high]
theorem addHom_ext' {M : Type*} [AddMonoid M] {f g : R[X] →+ M}
(h : ∀ n, f.comp (monomial n).toAddMonoidHom = g.comp (monomial n).toAddMonoidHom) : f = g :=
addHom_ext fun n => DFunLike.congr_fun (h n)
#align polynomial.add_hom_ext' Polynomial.addHom_ext'
@[ext high]
theorem lhom_ext' {M : Type*} [AddCommMonoid M] [Module R M] {f g : R[X] →ₗ[R] M}
(h : ∀ n, f.comp (monomial n) = g.comp (monomial n)) : f = g :=
LinearMap.toAddMonoidHom_injective <| addHom_ext fun n => LinearMap.congr_fun (h n)
#align polynomial.lhom_ext' Polynomial.lhom_ext'
-- this has the same content as the subsingleton
theorem eq_zero_of_eq_zero (h : (0 : R) = (1 : R)) (p : R[X]) : p = 0 := by
rw [← one_smul R p, ← h, zero_smul]
#align polynomial.eq_zero_of_eq_zero Polynomial.eq_zero_of_eq_zero
theorem X_pow_eq_monomial (n) : X ^ n = monomial n (1 : R) := by
induction' n with n hn
· rw [pow_zero, monomial_zero_one]
· rw [pow_succ, hn, X, monomial_mul_monomial, one_mul]
#align polynomial.X_pow_eq_monomial Polynomial.X_pow_eq_monomial
@[simp high]
theorem toFinsupp_X_pow (n : ℕ) : (X ^ n).toFinsupp = Finsupp.single n (1 : R) := by
rw [X_pow_eq_monomial, toFinsupp_monomial]
#align polynomial.to_finsupp_X_pow Polynomial.toFinsupp_X_pow
theorem smul_X_eq_monomial {n} : a • X ^ n = monomial n (a : R) := by
rw [X_pow_eq_monomial, smul_monomial, smul_eq_mul, mul_one]
#align polynomial.smul_X_eq_monomial Polynomial.smul_X_eq_monomial
theorem support_X_pow (H : ¬(1 : R) = 0) (n : ℕ) : (X ^ n : R[X]).support = singleton n := by
convert support_monomial n H
exact X_pow_eq_monomial n
#align polynomial.support_X_pow Polynomial.support_X_pow
theorem support_X_empty (H : (1 : R) = 0) : (X : R[X]).support = ∅ := by
rw [X, H, monomial_zero_right, support_zero]
#align polynomial.support_X_empty Polynomial.support_X_empty
theorem support_X (H : ¬(1 : R) = 0) : (X : R[X]).support = singleton 1 := by
rw [← pow_one X, support_X_pow H 1]
#align polynomial.support_X Polynomial.support_X
theorem monomial_left_inj {a : R} (ha : a ≠ 0) {i j : ℕ} :
monomial i a = monomial j a ↔ i = j := by
simp only [← ofFinsupp_single, ofFinsupp.injEq, Finsupp.single_left_inj ha]
#align polynomial.monomial_left_inj Polynomial.monomial_left_inj
theorem binomial_eq_binomial {k l m n : ℕ} {u v : R} (hu : u ≠ 0) (hv : v ≠ 0) :
C u * X ^ k + C v * X ^ l = C u * X ^ m + C v * X ^ n ↔
k = m ∧ l = n ∨ u = v ∧ k = n ∧ l = m ∨ u + v = 0 ∧ k = l ∧ m = n := by
simp_rw [C_mul_X_pow_eq_monomial, ← toFinsupp_inj, toFinsupp_add, toFinsupp_monomial]
exact Finsupp.single_add_single_eq_single_add_single hu hv
#align polynomial.binomial_eq_binomial Polynomial.binomial_eq_binomial
theorem natCast_mul (n : ℕ) (p : R[X]) : (n : R[X]) * p = n • p :=
(nsmul_eq_mul _ _).symm
#align polynomial.nat_cast_mul Polynomial.natCast_mul
@[deprecated (since := "2024-04-17")]
alias nat_cast_mul := natCast_mul
def sum {S : Type*} [AddCommMonoid S] (p : R[X]) (f : ℕ → R → S) : S :=
∑ n ∈ p.support, f n (p.coeff n)
#align polynomial.sum Polynomial.sum
theorem sum_def {S : Type*} [AddCommMonoid S] (p : R[X]) (f : ℕ → R → S) :
p.sum f = ∑ n ∈ p.support, f n (p.coeff n) :=
rfl
#align polynomial.sum_def Polynomial.sum_def
theorem sum_eq_of_subset {S : Type*} [AddCommMonoid S] {p : R[X]} (f : ℕ → R → S)
(hf : ∀ i, f i 0 = 0) {s : Finset ℕ} (hs : p.support ⊆ s) :
p.sum f = ∑ n ∈ s, f n (p.coeff n) :=
Finsupp.sum_of_support_subset _ hs f (fun i _ ↦ hf i)
#align polynomial.sum_eq_of_subset Polynomial.sum_eq_of_subset
theorem mul_eq_sum_sum :
p * q = ∑ i ∈ p.support, q.sum fun j a => (monomial (i + j)) (p.coeff i * a) := by
apply toFinsupp_injective
rcases p with ⟨⟩; rcases q with ⟨⟩
simp_rw [sum, coeff, toFinsupp_sum, support, toFinsupp_mul, toFinsupp_monomial,
AddMonoidAlgebra.mul_def, Finsupp.sum]
#align polynomial.mul_eq_sum_sum Polynomial.mul_eq_sum_sum
@[simp]
theorem sum_zero_index {S : Type*} [AddCommMonoid S] (f : ℕ → R → S) : (0 : R[X]).sum f = 0 := by
simp [sum]
#align polynomial.sum_zero_index Polynomial.sum_zero_index
@[simp]
theorem sum_monomial_index {S : Type*} [AddCommMonoid S] {n : ℕ} (a : R) (f : ℕ → R → S)
(hf : f n 0 = 0) : (monomial n a : R[X]).sum f = f n a :=
Finsupp.sum_single_index hf
#align polynomial.sum_monomial_index Polynomial.sum_monomial_index
@[simp]
theorem sum_C_index {a} {β} [AddCommMonoid β] {f : ℕ → R → β} (h : f 0 0 = 0) :
(C a).sum f = f 0 a :=
sum_monomial_index a f h
#align polynomial.sum_C_index Polynomial.sum_C_index
-- the assumption `hf` is only necessary when the ring is trivial
@[simp]
theorem sum_X_index {S : Type*} [AddCommMonoid S] {f : ℕ → R → S} (hf : f 1 0 = 0) :
(X : R[X]).sum f = f 1 1 :=
sum_monomial_index 1 f hf
#align polynomial.sum_X_index Polynomial.sum_X_index
theorem sum_add_index {S : Type*} [AddCommMonoid S] (p q : R[X]) (f : ℕ → R → S)
(hf : ∀ i, f i 0 = 0) (h_add : ∀ a b₁ b₂, f a (b₁ + b₂) = f a b₁ + f a b₂) :
(p + q).sum f = p.sum f + q.sum f := by
rw [show p + q = ⟨p.toFinsupp + q.toFinsupp⟩ from add_def p q]
exact Finsupp.sum_add_index (fun i _ ↦ hf i) (fun a _ b₁ b₂ ↦ h_add a b₁ b₂)
#align polynomial.sum_add_index Polynomial.sum_add_index
theorem sum_add' {S : Type*} [AddCommMonoid S] (p : R[X]) (f g : ℕ → R → S) :
p.sum (f + g) = p.sum f + p.sum g := by simp [sum_def, Finset.sum_add_distrib]
#align polynomial.sum_add' Polynomial.sum_add'
theorem sum_add {S : Type*} [AddCommMonoid S] (p : R[X]) (f g : ℕ → R → S) :
(p.sum fun n x => f n x + g n x) = p.sum f + p.sum g :=
sum_add' _ _ _
#align polynomial.sum_add Polynomial.sum_add
theorem sum_smul_index {S : Type*} [AddCommMonoid S] (p : R[X]) (b : R) (f : ℕ → R → S)
(hf : ∀ i, f i 0 = 0) : (b • p).sum f = p.sum fun n a => f n (b * a) :=
Finsupp.sum_smul_index hf
#align polynomial.sum_smul_index Polynomial.sum_smul_index
@[simp]
theorem sum_monomial_eq : ∀ p : R[X], (p.sum fun n a => monomial n a) = p
| ⟨_p⟩ => (ofFinsupp_sum _ _).symm.trans (congr_arg _ <| Finsupp.sum_single _)
#align polynomial.sum_monomial_eq Polynomial.sum_monomial_eq
theorem sum_C_mul_X_pow_eq (p : R[X]) : (p.sum fun n a => C a * X ^ n) = p := by
simp_rw [C_mul_X_pow_eq_monomial, sum_monomial_eq]
#align polynomial.sum_C_mul_X_pow_eq Polynomial.sum_C_mul_X_pow_eq
irreducible_def erase (n : ℕ) : R[X] → R[X]
| ⟨p⟩ => ⟨p.erase n⟩
#align polynomial.erase Polynomial.erase
@[simp]
theorem toFinsupp_erase (p : R[X]) (n : ℕ) : toFinsupp (p.erase n) = p.toFinsupp.erase n := by
rcases p with ⟨⟩
simp only [erase_def]
#align polynomial.to_finsupp_erase Polynomial.toFinsupp_erase
@[simp]
theorem ofFinsupp_erase (p : R[ℕ]) (n : ℕ) :
(⟨p.erase n⟩ : R[X]) = (⟨p⟩ : R[X]).erase n := by
rcases p with ⟨⟩
simp only [erase_def]
#align polynomial.of_finsupp_erase Polynomial.ofFinsupp_erase
@[simp]
theorem support_erase (p : R[X]) (n : ℕ) : support (p.erase n) = (support p).erase n := by
rcases p with ⟨⟩
simp only [support, erase_def, Finsupp.support_erase]
#align polynomial.support_erase Polynomial.support_erase
theorem monomial_add_erase (p : R[X]) (n : ℕ) : monomial n (coeff p n) + p.erase n = p :=
toFinsupp_injective <| by
rcases p with ⟨⟩
rw [toFinsupp_add, toFinsupp_monomial, toFinsupp_erase, coeff]
exact Finsupp.single_add_erase _ _
#align polynomial.monomial_add_erase Polynomial.monomial_add_erase
theorem coeff_erase (p : R[X]) (n i : ℕ) :
(p.erase n).coeff i = if i = n then 0 else p.coeff i := by
rcases p with ⟨⟩
simp only [erase_def, coeff]
-- Porting note: Was `convert rfl`.
exact ite_congr rfl (fun _ => rfl) (fun _ => rfl)
#align polynomial.coeff_erase Polynomial.coeff_erase
@[simp]
theorem erase_zero (n : ℕ) : (0 : R[X]).erase n = 0 :=
toFinsupp_injective <| by simp
#align polynomial.erase_zero Polynomial.erase_zero
@[simp]
theorem erase_monomial {n : ℕ} {a : R} : erase n (monomial n a) = 0 :=
toFinsupp_injective <| by simp
#align polynomial.erase_monomial Polynomial.erase_monomial
@[simp]
theorem erase_same (p : R[X]) (n : ℕ) : coeff (p.erase n) n = 0 := by simp [coeff_erase]
#align polynomial.erase_same Polynomial.erase_same
@[simp]
theorem erase_ne (p : R[X]) (n i : ℕ) (h : i ≠ n) : coeff (p.erase n) i = coeff p i := by
simp [coeff_erase, h]
#align polynomial.erase_ne Polynomial.erase_ne
section Update
def update (p : R[X]) (n : ℕ) (a : R) : R[X] :=
Polynomial.ofFinsupp (p.toFinsupp.update n a)
#align polynomial.update Polynomial.update
| Mathlib/Algebra/Polynomial/Basic.lean | 1,125 | 1,129 | theorem coeff_update (p : R[X]) (n : ℕ) (a : R) :
(p.update n a).coeff = Function.update p.coeff n a := by |
ext
cases p
simp only [coeff, update, Function.update_apply, coe_update]
|
import Mathlib.Analysis.Normed.Group.Pointwise
import Mathlib.Analysis.NormedSpace.Real
#align_import analysis.normed_space.pointwise from "leanprover-community/mathlib"@"bc91ed7093bf098d253401e69df601fc33dde156"
open Metric Set
open Pointwise Topology
variable {𝕜 E : Type*}
variable [NormedField 𝕜]
section NormedAddCommGroup
variable [NormedAddCommGroup E] [NormedSpace 𝕜 E]
theorem smul_closedBall (c : 𝕜) (x : E) {r : ℝ} (hr : 0 ≤ r) :
c • closedBall x r = closedBall (c • x) (‖c‖ * r) := by
rcases eq_or_ne c 0 with (rfl | hc)
· simp [hr, zero_smul_set, Set.singleton_zero, nonempty_closedBall]
· exact smul_closedBall' hc x r
#align smul_closed_ball smul_closedBall
theorem smul_closedUnitBall (c : 𝕜) : c • closedBall (0 : E) (1 : ℝ) = closedBall (0 : E) ‖c‖ := by
rw [smul_closedBall _ _ zero_le_one, smul_zero, mul_one]
#align smul_closed_unit_ball smul_closedUnitBall
variable [NormedSpace ℝ E]
theorem smul_closedUnitBall_of_nonneg {r : ℝ} (hr : 0 ≤ r) :
r • closedBall (0 : E) 1 = closedBall (0 : E) r := by
rw [smul_closedUnitBall, Real.norm_of_nonneg hr]
#align smul_closed_unit_ball_of_nonneg smul_closedUnitBall_of_nonneg
@[simp]
| Mathlib/Analysis/NormedSpace/Pointwise.lean | 423 | 432 | theorem NormedSpace.sphere_nonempty [Nontrivial E] {x : E} {r : ℝ} :
(sphere x r).Nonempty ↔ 0 ≤ r := by |
obtain ⟨y, hy⟩ := exists_ne x
refine ⟨fun h => nonempty_closedBall.1 (h.mono sphere_subset_closedBall), fun hr =>
⟨r • ‖y - x‖⁻¹ • (y - x) + x, ?_⟩⟩
have : ‖y - x‖ ≠ 0 := by simpa [sub_eq_zero]
simp only [mem_sphere_iff_norm, add_sub_cancel_right, norm_smul, Real.norm_eq_abs, norm_inv,
norm_norm, ne_eq, norm_eq_zero]
simp only [abs_norm, ne_eq, norm_eq_zero]
rw [inv_mul_cancel this, mul_one, abs_eq_self.mpr hr]
|
import Mathlib.Dynamics.Ergodic.MeasurePreserving
import Mathlib.MeasureTheory.Function.SimpleFunc
import Mathlib.MeasureTheory.Measure.MutuallySingular
import Mathlib.MeasureTheory.Measure.Count
import Mathlib.Topology.IndicatorConstPointwise
import Mathlib.MeasureTheory.Constructions.BorelSpace.Real
#align_import measure_theory.integral.lebesgue from "leanprover-community/mathlib"@"c14c8fcde993801fca8946b0d80131a1a81d1520"
assert_not_exists NormedSpace
set_option autoImplicit true
noncomputable section
open Set hiding restrict restrict_apply
open Filter ENNReal
open Function (support)
open scoped Classical
open Topology NNReal ENNReal MeasureTheory
namespace MeasureTheory
local infixr:25 " →ₛ " => SimpleFunc
variable {α β γ δ : Type*}
section Lintegral
open SimpleFunc
variable {m : MeasurableSpace α} {μ ν : Measure α}
irreducible_def lintegral {_ : MeasurableSpace α} (μ : Measure α) (f : α → ℝ≥0∞) : ℝ≥0∞ :=
⨆ (g : α →ₛ ℝ≥0∞) (_ : ⇑g ≤ f), g.lintegral μ
#align measure_theory.lintegral MeasureTheory.lintegral
@[inherit_doc MeasureTheory.lintegral]
notation3 "∫⁻ "(...)", "r:60:(scoped f => f)" ∂"μ:70 => lintegral μ r
@[inherit_doc MeasureTheory.lintegral]
notation3 "∫⁻ "(...)", "r:60:(scoped f => lintegral volume f) => r
@[inherit_doc MeasureTheory.lintegral]
notation3"∫⁻ "(...)" in "s", "r:60:(scoped f => f)" ∂"μ:70 => lintegral (Measure.restrict μ s) r
@[inherit_doc MeasureTheory.lintegral]
notation3"∫⁻ "(...)" in "s", "r:60:(scoped f => lintegral (Measure.restrict volume s) f) => r
theorem SimpleFunc.lintegral_eq_lintegral {m : MeasurableSpace α} (f : α →ₛ ℝ≥0∞) (μ : Measure α) :
∫⁻ a, f a ∂μ = f.lintegral μ := by
rw [MeasureTheory.lintegral]
exact le_antisymm (iSup₂_le fun g hg => lintegral_mono hg <| le_rfl)
(le_iSup₂_of_le f le_rfl le_rfl)
#align measure_theory.simple_func.lintegral_eq_lintegral MeasureTheory.SimpleFunc.lintegral_eq_lintegral
@[mono]
theorem lintegral_mono' {m : MeasurableSpace α} ⦃μ ν : Measure α⦄ (hμν : μ ≤ ν) ⦃f g : α → ℝ≥0∞⦄
(hfg : f ≤ g) : ∫⁻ a, f a ∂μ ≤ ∫⁻ a, g a ∂ν := by
rw [lintegral, lintegral]
exact iSup_mono fun φ => iSup_mono' fun hφ => ⟨le_trans hφ hfg, lintegral_mono (le_refl φ) hμν⟩
#align measure_theory.lintegral_mono' MeasureTheory.lintegral_mono'
-- workaround for the known eta-reduction issue with `@[gcongr]`
@[gcongr] theorem lintegral_mono_fn' ⦃f g : α → ℝ≥0∞⦄ (hfg : ∀ x, f x ≤ g x) (h2 : μ ≤ ν) :
lintegral μ f ≤ lintegral ν g :=
lintegral_mono' h2 hfg
theorem lintegral_mono ⦃f g : α → ℝ≥0∞⦄ (hfg : f ≤ g) : ∫⁻ a, f a ∂μ ≤ ∫⁻ a, g a ∂μ :=
lintegral_mono' (le_refl μ) hfg
#align measure_theory.lintegral_mono MeasureTheory.lintegral_mono
-- workaround for the known eta-reduction issue with `@[gcongr]`
@[gcongr] theorem lintegral_mono_fn ⦃f g : α → ℝ≥0∞⦄ (hfg : ∀ x, f x ≤ g x) :
lintegral μ f ≤ lintegral μ g :=
lintegral_mono hfg
theorem lintegral_mono_nnreal {f g : α → ℝ≥0} (h : f ≤ g) : ∫⁻ a, f a ∂μ ≤ ∫⁻ a, g a ∂μ :=
lintegral_mono fun a => ENNReal.coe_le_coe.2 (h a)
#align measure_theory.lintegral_mono_nnreal MeasureTheory.lintegral_mono_nnreal
theorem iSup_lintegral_measurable_le_eq_lintegral (f : α → ℝ≥0∞) :
⨆ (g : α → ℝ≥0∞) (_ : Measurable g) (_ : g ≤ f), ∫⁻ a, g a ∂μ = ∫⁻ a, f a ∂μ := by
apply le_antisymm
· exact iSup_le fun i => iSup_le fun _ => iSup_le fun h'i => lintegral_mono h'i
· rw [lintegral]
refine iSup₂_le fun i hi => le_iSup₂_of_le i i.measurable <| le_iSup_of_le hi ?_
exact le_of_eq (i.lintegral_eq_lintegral _).symm
#align measure_theory.supr_lintegral_measurable_le_eq_lintegral MeasureTheory.iSup_lintegral_measurable_le_eq_lintegral
theorem lintegral_mono_set {_ : MeasurableSpace α} ⦃μ : Measure α⦄ {s t : Set α} {f : α → ℝ≥0∞}
(hst : s ⊆ t) : ∫⁻ x in s, f x ∂μ ≤ ∫⁻ x in t, f x ∂μ :=
lintegral_mono' (Measure.restrict_mono hst (le_refl μ)) (le_refl f)
#align measure_theory.lintegral_mono_set MeasureTheory.lintegral_mono_set
theorem lintegral_mono_set' {_ : MeasurableSpace α} ⦃μ : Measure α⦄ {s t : Set α} {f : α → ℝ≥0∞}
(hst : s ≤ᵐ[μ] t) : ∫⁻ x in s, f x ∂μ ≤ ∫⁻ x in t, f x ∂μ :=
lintegral_mono' (Measure.restrict_mono' hst (le_refl μ)) (le_refl f)
#align measure_theory.lintegral_mono_set' MeasureTheory.lintegral_mono_set'
theorem monotone_lintegral {_ : MeasurableSpace α} (μ : Measure α) : Monotone (lintegral μ) :=
lintegral_mono
#align measure_theory.monotone_lintegral MeasureTheory.monotone_lintegral
@[simp]
theorem lintegral_const (c : ℝ≥0∞) : ∫⁻ _, c ∂μ = c * μ univ := by
rw [← SimpleFunc.const_lintegral, ← SimpleFunc.lintegral_eq_lintegral, SimpleFunc.coe_const]
rfl
#align measure_theory.lintegral_const MeasureTheory.lintegral_const
theorem lintegral_zero : ∫⁻ _ : α, 0 ∂μ = 0 := by simp
#align measure_theory.lintegral_zero MeasureTheory.lintegral_zero
theorem lintegral_zero_fun : lintegral μ (0 : α → ℝ≥0∞) = 0 :=
lintegral_zero
#align measure_theory.lintegral_zero_fun MeasureTheory.lintegral_zero_fun
-- @[simp] -- Porting note (#10618): simp can prove this
theorem lintegral_one : ∫⁻ _, (1 : ℝ≥0∞) ∂μ = μ univ := by rw [lintegral_const, one_mul]
#align measure_theory.lintegral_one MeasureTheory.lintegral_one
theorem set_lintegral_const (s : Set α) (c : ℝ≥0∞) : ∫⁻ _ in s, c ∂μ = c * μ s := by
rw [lintegral_const, Measure.restrict_apply_univ]
#align measure_theory.set_lintegral_const MeasureTheory.set_lintegral_const
theorem set_lintegral_one (s) : ∫⁻ _ in s, 1 ∂μ = μ s := by rw [set_lintegral_const, one_mul]
#align measure_theory.set_lintegral_one MeasureTheory.set_lintegral_one
theorem set_lintegral_const_lt_top [IsFiniteMeasure μ] (s : Set α) {c : ℝ≥0∞} (hc : c ≠ ∞) :
∫⁻ _ in s, c ∂μ < ∞ := by
rw [lintegral_const]
exact ENNReal.mul_lt_top hc (measure_ne_top (μ.restrict s) univ)
#align measure_theory.set_lintegral_const_lt_top MeasureTheory.set_lintegral_const_lt_top
theorem lintegral_const_lt_top [IsFiniteMeasure μ] {c : ℝ≥0∞} (hc : c ≠ ∞) : ∫⁻ _, c ∂μ < ∞ := by
simpa only [Measure.restrict_univ] using set_lintegral_const_lt_top (univ : Set α) hc
#align measure_theory.lintegral_const_lt_top MeasureTheory.lintegral_const_lt_top
section
variable (μ)
theorem exists_measurable_le_lintegral_eq (f : α → ℝ≥0∞) :
∃ g : α → ℝ≥0∞, Measurable g ∧ g ≤ f ∧ ∫⁻ a, f a ∂μ = ∫⁻ a, g a ∂μ := by
rcases eq_or_ne (∫⁻ a, f a ∂μ) 0 with h₀ | h₀
· exact ⟨0, measurable_zero, zero_le f, h₀.trans lintegral_zero.symm⟩
rcases exists_seq_strictMono_tendsto' h₀.bot_lt with ⟨L, _, hLf, hL_tendsto⟩
have : ∀ n, ∃ g : α → ℝ≥0∞, Measurable g ∧ g ≤ f ∧ L n < ∫⁻ a, g a ∂μ := by
intro n
simpa only [← iSup_lintegral_measurable_le_eq_lintegral f, lt_iSup_iff, exists_prop] using
(hLf n).2
choose g hgm hgf hLg using this
refine
⟨fun x => ⨆ n, g n x, measurable_iSup hgm, fun x => iSup_le fun n => hgf n x, le_antisymm ?_ ?_⟩
· refine le_of_tendsto' hL_tendsto fun n => (hLg n).le.trans <| lintegral_mono fun x => ?_
exact le_iSup (fun n => g n x) n
· exact lintegral_mono fun x => iSup_le fun n => hgf n x
#align measure_theory.exists_measurable_le_lintegral_eq MeasureTheory.exists_measurable_le_lintegral_eq
end
theorem lintegral_eq_nnreal {m : MeasurableSpace α} (f : α → ℝ≥0∞) (μ : Measure α) :
∫⁻ a, f a ∂μ =
⨆ (φ : α →ₛ ℝ≥0) (_ : ∀ x, ↑(φ x) ≤ f x), (φ.map ((↑) : ℝ≥0 → ℝ≥0∞)).lintegral μ := by
rw [lintegral]
refine
le_antisymm (iSup₂_le fun φ hφ => ?_) (iSup_mono' fun φ => ⟨φ.map ((↑) : ℝ≥0 → ℝ≥0∞), le_rfl⟩)
by_cases h : ∀ᵐ a ∂μ, φ a ≠ ∞
· let ψ := φ.map ENNReal.toNNReal
replace h : ψ.map ((↑) : ℝ≥0 → ℝ≥0∞) =ᵐ[μ] φ := h.mono fun a => ENNReal.coe_toNNReal
have : ∀ x, ↑(ψ x) ≤ f x := fun x => le_trans ENNReal.coe_toNNReal_le_self (hφ x)
exact
le_iSup_of_le (φ.map ENNReal.toNNReal) (le_iSup_of_le this (ge_of_eq <| lintegral_congr h))
· have h_meas : μ (φ ⁻¹' {∞}) ≠ 0 := mt measure_zero_iff_ae_nmem.1 h
refine le_trans le_top (ge_of_eq <| (iSup_eq_top _).2 fun b hb => ?_)
obtain ⟨n, hn⟩ : ∃ n : ℕ, b < n * μ (φ ⁻¹' {∞}) := exists_nat_mul_gt h_meas (ne_of_lt hb)
use (const α (n : ℝ≥0)).restrict (φ ⁻¹' {∞})
simp only [lt_iSup_iff, exists_prop, coe_restrict, φ.measurableSet_preimage, coe_const,
ENNReal.coe_indicator, map_coe_ennreal_restrict, SimpleFunc.map_const, ENNReal.coe_natCast,
restrict_const_lintegral]
refine ⟨indicator_le fun x hx => le_trans ?_ (hφ _), hn⟩
simp only [mem_preimage, mem_singleton_iff] at hx
simp only [hx, le_top]
#align measure_theory.lintegral_eq_nnreal MeasureTheory.lintegral_eq_nnreal
theorem exists_simpleFunc_forall_lintegral_sub_lt_of_pos {f : α → ℝ≥0∞} (h : ∫⁻ x, f x ∂μ ≠ ∞)
{ε : ℝ≥0∞} (hε : ε ≠ 0) :
∃ φ : α →ₛ ℝ≥0,
(∀ x, ↑(φ x) ≤ f x) ∧
∀ ψ : α →ₛ ℝ≥0, (∀ x, ↑(ψ x) ≤ f x) → (map (↑) (ψ - φ)).lintegral μ < ε := by
rw [lintegral_eq_nnreal] at h
have := ENNReal.lt_add_right h hε
erw [ENNReal.biSup_add] at this <;> [skip; exact ⟨0, fun x => zero_le _⟩]
simp_rw [lt_iSup_iff, iSup_lt_iff, iSup_le_iff] at this
rcases this with ⟨φ, hle : ∀ x, ↑(φ x) ≤ f x, b, hbφ, hb⟩
refine ⟨φ, hle, fun ψ hψ => ?_⟩
have : (map (↑) φ).lintegral μ ≠ ∞ := ne_top_of_le_ne_top h (by exact le_iSup₂ (α := ℝ≥0∞) φ hle)
rw [← ENNReal.add_lt_add_iff_left this, ← add_lintegral, ← SimpleFunc.map_add @ENNReal.coe_add]
refine (hb _ fun x => le_trans ?_ (max_le (hle x) (hψ x))).trans_lt hbφ
norm_cast
simp only [add_apply, sub_apply, add_tsub_eq_max]
rfl
#align measure_theory.exists_simple_func_forall_lintegral_sub_lt_of_pos MeasureTheory.exists_simpleFunc_forall_lintegral_sub_lt_of_pos
theorem iSup_lintegral_le {ι : Sort*} (f : ι → α → ℝ≥0∞) :
⨆ i, ∫⁻ a, f i a ∂μ ≤ ∫⁻ a, ⨆ i, f i a ∂μ := by
simp only [← iSup_apply]
exact (monotone_lintegral μ).le_map_iSup
#align measure_theory.supr_lintegral_le MeasureTheory.iSup_lintegral_le
theorem iSup₂_lintegral_le {ι : Sort*} {ι' : ι → Sort*} (f : ∀ i, ι' i → α → ℝ≥0∞) :
⨆ (i) (j), ∫⁻ a, f i j a ∂μ ≤ ∫⁻ a, ⨆ (i) (j), f i j a ∂μ := by
convert (monotone_lintegral μ).le_map_iSup₂ f with a
simp only [iSup_apply]
#align measure_theory.supr₂_lintegral_le MeasureTheory.iSup₂_lintegral_le
theorem le_iInf_lintegral {ι : Sort*} (f : ι → α → ℝ≥0∞) :
∫⁻ a, ⨅ i, f i a ∂μ ≤ ⨅ i, ∫⁻ a, f i a ∂μ := by
simp only [← iInf_apply]
exact (monotone_lintegral μ).map_iInf_le
#align measure_theory.le_infi_lintegral MeasureTheory.le_iInf_lintegral
theorem le_iInf₂_lintegral {ι : Sort*} {ι' : ι → Sort*} (f : ∀ i, ι' i → α → ℝ≥0∞) :
∫⁻ a, ⨅ (i) (h : ι' i), f i h a ∂μ ≤ ⨅ (i) (h : ι' i), ∫⁻ a, f i h a ∂μ := by
convert (monotone_lintegral μ).map_iInf₂_le f with a
simp only [iInf_apply]
#align measure_theory.le_infi₂_lintegral MeasureTheory.le_iInf₂_lintegral
theorem lintegral_mono_ae {f g : α → ℝ≥0∞} (h : ∀ᵐ a ∂μ, f a ≤ g a) :
∫⁻ a, f a ∂μ ≤ ∫⁻ a, g a ∂μ := by
rcases exists_measurable_superset_of_null h with ⟨t, hts, ht, ht0⟩
have : ∀ᵐ x ∂μ, x ∉ t := measure_zero_iff_ae_nmem.1 ht0
rw [lintegral, lintegral]
refine iSup_le fun s => iSup_le fun hfs => le_iSup_of_le (s.restrict tᶜ) <| le_iSup_of_le ?_ ?_
· intro a
by_cases h : a ∈ t <;>
simp only [restrict_apply s ht.compl, mem_compl_iff, h, not_true, not_false_eq_true,
indicator_of_not_mem, zero_le, not_false_eq_true, indicator_of_mem]
exact le_trans (hfs a) (_root_.by_contradiction fun hnfg => h (hts hnfg))
· refine le_of_eq (SimpleFunc.lintegral_congr <| this.mono fun a hnt => ?_)
by_cases hat : a ∈ t <;> simp only [restrict_apply s ht.compl, mem_compl_iff, hat, not_true,
not_false_eq_true, indicator_of_not_mem, not_false_eq_true, indicator_of_mem]
exact (hnt hat).elim
#align measure_theory.lintegral_mono_ae MeasureTheory.lintegral_mono_ae
theorem set_lintegral_mono_ae {s : Set α} {f g : α → ℝ≥0∞} (hf : Measurable f) (hg : Measurable g)
(hfg : ∀ᵐ x ∂μ, x ∈ s → f x ≤ g x) : ∫⁻ x in s, f x ∂μ ≤ ∫⁻ x in s, g x ∂μ :=
lintegral_mono_ae <| (ae_restrict_iff <| measurableSet_le hf hg).2 hfg
#align measure_theory.set_lintegral_mono_ae MeasureTheory.set_lintegral_mono_ae
theorem set_lintegral_mono {s : Set α} {f g : α → ℝ≥0∞} (hf : Measurable f) (hg : Measurable g)
(hfg : ∀ x ∈ s, f x ≤ g x) : ∫⁻ x in s, f x ∂μ ≤ ∫⁻ x in s, g x ∂μ :=
set_lintegral_mono_ae hf hg (ae_of_all _ hfg)
#align measure_theory.set_lintegral_mono MeasureTheory.set_lintegral_mono
theorem set_lintegral_mono_ae' {s : Set α} {f g : α → ℝ≥0∞} (hs : MeasurableSet s)
(hfg : ∀ᵐ x ∂μ, x ∈ s → f x ≤ g x) : ∫⁻ x in s, f x ∂μ ≤ ∫⁻ x in s, g x ∂μ :=
lintegral_mono_ae <| (ae_restrict_iff' hs).2 hfg
theorem set_lintegral_mono' {s : Set α} {f g : α → ℝ≥0∞} (hs : MeasurableSet s)
(hfg : ∀ x ∈ s, f x ≤ g x) : ∫⁻ x in s, f x ∂μ ≤ ∫⁻ x in s, g x ∂μ :=
set_lintegral_mono_ae' hs (ae_of_all _ hfg)
theorem set_lintegral_le_lintegral (s : Set α) (f : α → ℝ≥0∞) :
∫⁻ x in s, f x ∂μ ≤ ∫⁻ x, f x ∂μ :=
lintegral_mono' Measure.restrict_le_self le_rfl
theorem lintegral_congr_ae {f g : α → ℝ≥0∞} (h : f =ᵐ[μ] g) : ∫⁻ a, f a ∂μ = ∫⁻ a, g a ∂μ :=
le_antisymm (lintegral_mono_ae <| h.le) (lintegral_mono_ae <| h.symm.le)
#align measure_theory.lintegral_congr_ae MeasureTheory.lintegral_congr_ae
theorem lintegral_congr {f g : α → ℝ≥0∞} (h : ∀ a, f a = g a) : ∫⁻ a, f a ∂μ = ∫⁻ a, g a ∂μ := by
simp only [h]
#align measure_theory.lintegral_congr MeasureTheory.lintegral_congr
theorem set_lintegral_congr {f : α → ℝ≥0∞} {s t : Set α} (h : s =ᵐ[μ] t) :
∫⁻ x in s, f x ∂μ = ∫⁻ x in t, f x ∂μ := by rw [Measure.restrict_congr_set h]
#align measure_theory.set_lintegral_congr MeasureTheory.set_lintegral_congr
theorem set_lintegral_congr_fun {f g : α → ℝ≥0∞} {s : Set α} (hs : MeasurableSet s)
(hfg : ∀ᵐ x ∂μ, x ∈ s → f x = g x) : ∫⁻ x in s, f x ∂μ = ∫⁻ x in s, g x ∂μ := by
rw [lintegral_congr_ae]
rw [EventuallyEq]
rwa [ae_restrict_iff' hs]
#align measure_theory.set_lintegral_congr_fun MeasureTheory.set_lintegral_congr_fun
theorem lintegral_ofReal_le_lintegral_nnnorm (f : α → ℝ) :
∫⁻ x, ENNReal.ofReal (f x) ∂μ ≤ ∫⁻ x, ‖f x‖₊ ∂μ := by
simp_rw [← ofReal_norm_eq_coe_nnnorm]
refine lintegral_mono fun x => ENNReal.ofReal_le_ofReal ?_
rw [Real.norm_eq_abs]
exact le_abs_self (f x)
#align measure_theory.lintegral_of_real_le_lintegral_nnnorm MeasureTheory.lintegral_ofReal_le_lintegral_nnnorm
theorem lintegral_nnnorm_eq_of_ae_nonneg {f : α → ℝ} (h_nonneg : 0 ≤ᵐ[μ] f) :
∫⁻ x, ‖f x‖₊ ∂μ = ∫⁻ x, ENNReal.ofReal (f x) ∂μ := by
apply lintegral_congr_ae
filter_upwards [h_nonneg] with x hx
rw [Real.nnnorm_of_nonneg hx, ENNReal.ofReal_eq_coe_nnreal hx]
#align measure_theory.lintegral_nnnorm_eq_of_ae_nonneg MeasureTheory.lintegral_nnnorm_eq_of_ae_nonneg
theorem lintegral_nnnorm_eq_of_nonneg {f : α → ℝ} (h_nonneg : 0 ≤ f) :
∫⁻ x, ‖f x‖₊ ∂μ = ∫⁻ x, ENNReal.ofReal (f x) ∂μ :=
lintegral_nnnorm_eq_of_ae_nonneg (Filter.eventually_of_forall h_nonneg)
#align measure_theory.lintegral_nnnorm_eq_of_nonneg MeasureTheory.lintegral_nnnorm_eq_of_nonneg
theorem lintegral_iSup {f : ℕ → α → ℝ≥0∞} (hf : ∀ n, Measurable (f n)) (h_mono : Monotone f) :
∫⁻ a, ⨆ n, f n a ∂μ = ⨆ n, ∫⁻ a, f n a ∂μ := by
set c : ℝ≥0 → ℝ≥0∞ := (↑)
set F := fun a : α => ⨆ n, f n a
refine le_antisymm ?_ (iSup_lintegral_le _)
rw [lintegral_eq_nnreal]
refine iSup_le fun s => iSup_le fun hsf => ?_
refine ENNReal.le_of_forall_lt_one_mul_le fun a ha => ?_
rcases ENNReal.lt_iff_exists_coe.1 ha with ⟨r, rfl, _⟩
have ha : r < 1 := ENNReal.coe_lt_coe.1 ha
let rs := s.map fun a => r * a
have eq_rs : rs.map c = (const α r : α →ₛ ℝ≥0∞) * map c s := rfl
have eq : ∀ p, rs.map c ⁻¹' {p} = ⋃ n, rs.map c ⁻¹' {p} ∩ { a | p ≤ f n a } := by
intro p
rw [← inter_iUnion]; nth_rw 1 [← inter_univ (map c rs ⁻¹' {p})]
refine Set.ext fun x => and_congr_right fun hx => true_iff_iff.2 ?_
by_cases p_eq : p = 0
· simp [p_eq]
simp only [coe_map, mem_preimage, Function.comp_apply, mem_singleton_iff] at hx
subst hx
have : r * s x ≠ 0 := by rwa [Ne, ← ENNReal.coe_eq_zero]
have : s x ≠ 0 := right_ne_zero_of_mul this
have : (rs.map c) x < ⨆ n : ℕ, f n x := by
refine lt_of_lt_of_le (ENNReal.coe_lt_coe.2 ?_) (hsf x)
suffices r * s x < 1 * s x by simpa
exact mul_lt_mul_of_pos_right ha (pos_iff_ne_zero.2 this)
rcases lt_iSup_iff.1 this with ⟨i, hi⟩
exact mem_iUnion.2 ⟨i, le_of_lt hi⟩
have mono : ∀ r : ℝ≥0∞, Monotone fun n => rs.map c ⁻¹' {r} ∩ { a | r ≤ f n a } := by
intro r i j h
refine inter_subset_inter_right _ ?_
simp_rw [subset_def, mem_setOf]
intro x hx
exact le_trans hx (h_mono h x)
have h_meas : ∀ n, MeasurableSet {a : α | map c rs a ≤ f n a} := fun n =>
measurableSet_le (SimpleFunc.measurable _) (hf n)
calc
(r : ℝ≥0∞) * (s.map c).lintegral μ = ∑ r ∈ (rs.map c).range, r * μ (rs.map c ⁻¹' {r}) := by
rw [← const_mul_lintegral, eq_rs, SimpleFunc.lintegral]
_ = ∑ r ∈ (rs.map c).range, r * μ (⋃ n, rs.map c ⁻¹' {r} ∩ { a | r ≤ f n a }) := by
simp only [(eq _).symm]
_ = ∑ r ∈ (rs.map c).range, ⨆ n, r * μ (rs.map c ⁻¹' {r} ∩ { a | r ≤ f n a }) :=
(Finset.sum_congr rfl fun x _ => by
rw [measure_iUnion_eq_iSup (mono x).directed_le, ENNReal.mul_iSup])
_ = ⨆ n, ∑ r ∈ (rs.map c).range, r * μ (rs.map c ⁻¹' {r} ∩ { a | r ≤ f n a }) := by
refine ENNReal.finset_sum_iSup_nat fun p i j h ↦ ?_
gcongr _ * μ ?_
exact mono p h
_ ≤ ⨆ n : ℕ, ((rs.map c).restrict { a | (rs.map c) a ≤ f n a }).lintegral μ := by
gcongr with n
rw [restrict_lintegral _ (h_meas n)]
refine le_of_eq (Finset.sum_congr rfl fun r _ => ?_)
congr 2 with a
refine and_congr_right ?_
simp (config := { contextual := true })
_ ≤ ⨆ n, ∫⁻ a, f n a ∂μ := by
simp only [← SimpleFunc.lintegral_eq_lintegral]
gcongr with n a
simp only [map_apply] at h_meas
simp only [coe_map, restrict_apply _ (h_meas _), (· ∘ ·)]
exact indicator_apply_le id
#align measure_theory.lintegral_supr MeasureTheory.lintegral_iSup
theorem lintegral_iSup' {f : ℕ → α → ℝ≥0∞} (hf : ∀ n, AEMeasurable (f n) μ)
(h_mono : ∀ᵐ x ∂μ, Monotone fun n => f n x) : ∫⁻ a, ⨆ n, f n a ∂μ = ⨆ n, ∫⁻ a, f n a ∂μ := by
simp_rw [← iSup_apply]
let p : α → (ℕ → ℝ≥0∞) → Prop := fun _ f' => Monotone f'
have hp : ∀ᵐ x ∂μ, p x fun i => f i x := h_mono
have h_ae_seq_mono : Monotone (aeSeq hf p) := by
intro n m hnm x
by_cases hx : x ∈ aeSeqSet hf p
· exact aeSeq.prop_of_mem_aeSeqSet hf hx hnm
· simp only [aeSeq, hx, if_false, le_rfl]
rw [lintegral_congr_ae (aeSeq.iSup hf hp).symm]
simp_rw [iSup_apply]
rw [lintegral_iSup (aeSeq.measurable hf p) h_ae_seq_mono]
congr with n
exact lintegral_congr_ae (aeSeq.aeSeq_n_eq_fun_n_ae hf hp n)
#align measure_theory.lintegral_supr' MeasureTheory.lintegral_iSup'
theorem lintegral_tendsto_of_tendsto_of_monotone {f : ℕ → α → ℝ≥0∞} {F : α → ℝ≥0∞}
(hf : ∀ n, AEMeasurable (f n) μ) (h_mono : ∀ᵐ x ∂μ, Monotone fun n => f n x)
(h_tendsto : ∀ᵐ x ∂μ, Tendsto (fun n => f n x) atTop (𝓝 <| F x)) :
Tendsto (fun n => ∫⁻ x, f n x ∂μ) atTop (𝓝 <| ∫⁻ x, F x ∂μ) := by
have : Monotone fun n => ∫⁻ x, f n x ∂μ := fun i j hij =>
lintegral_mono_ae (h_mono.mono fun x hx => hx hij)
suffices key : ∫⁻ x, F x ∂μ = ⨆ n, ∫⁻ x, f n x ∂μ by
rw [key]
exact tendsto_atTop_iSup this
rw [← lintegral_iSup' hf h_mono]
refine lintegral_congr_ae ?_
filter_upwards [h_mono, h_tendsto] with _ hx_mono hx_tendsto using
tendsto_nhds_unique hx_tendsto (tendsto_atTop_iSup hx_mono)
#align measure_theory.lintegral_tendsto_of_tendsto_of_monotone MeasureTheory.lintegral_tendsto_of_tendsto_of_monotone
theorem lintegral_eq_iSup_eapprox_lintegral {f : α → ℝ≥0∞} (hf : Measurable f) :
∫⁻ a, f a ∂μ = ⨆ n, (eapprox f n).lintegral μ :=
calc
∫⁻ a, f a ∂μ = ∫⁻ a, ⨆ n, (eapprox f n : α → ℝ≥0∞) a ∂μ := by
congr; ext a; rw [iSup_eapprox_apply f hf]
_ = ⨆ n, ∫⁻ a, (eapprox f n : α → ℝ≥0∞) a ∂μ := by
apply lintegral_iSup
· measurability
· intro i j h
exact monotone_eapprox f h
_ = ⨆ n, (eapprox f n).lintegral μ := by
congr; ext n; rw [(eapprox f n).lintegral_eq_lintegral]
#align measure_theory.lintegral_eq_supr_eapprox_lintegral MeasureTheory.lintegral_eq_iSup_eapprox_lintegral
theorem exists_pos_set_lintegral_lt_of_measure_lt {f : α → ℝ≥0∞} (h : ∫⁻ x, f x ∂μ ≠ ∞) {ε : ℝ≥0∞}
(hε : ε ≠ 0) : ∃ δ > 0, ∀ s, μ s < δ → ∫⁻ x in s, f x ∂μ < ε := by
rcases exists_between (pos_iff_ne_zero.mpr hε) with ⟨ε₂, hε₂0, hε₂ε⟩
rcases exists_between hε₂0 with ⟨ε₁, hε₁0, hε₁₂⟩
rcases exists_simpleFunc_forall_lintegral_sub_lt_of_pos h hε₁0.ne' with ⟨φ, _, hφ⟩
rcases φ.exists_forall_le with ⟨C, hC⟩
use (ε₂ - ε₁) / C, ENNReal.div_pos_iff.2 ⟨(tsub_pos_iff_lt.2 hε₁₂).ne', ENNReal.coe_ne_top⟩
refine fun s hs => lt_of_le_of_lt ?_ hε₂ε
simp only [lintegral_eq_nnreal, iSup_le_iff]
intro ψ hψ
calc
(map (↑) ψ).lintegral (μ.restrict s) ≤
(map (↑) φ).lintegral (μ.restrict s) + (map (↑) (ψ - φ)).lintegral (μ.restrict s) := by
rw [← SimpleFunc.add_lintegral, ← SimpleFunc.map_add @ENNReal.coe_add]
refine SimpleFunc.lintegral_mono (fun x => ?_) le_rfl
simp only [add_tsub_eq_max, le_max_right, coe_map, Function.comp_apply, SimpleFunc.coe_add,
SimpleFunc.coe_sub, Pi.add_apply, Pi.sub_apply, ENNReal.coe_max (φ x) (ψ x)]
_ ≤ (map (↑) φ).lintegral (μ.restrict s) + ε₁ := by
gcongr
refine le_trans ?_ (hφ _ hψ).le
exact SimpleFunc.lintegral_mono le_rfl Measure.restrict_le_self
_ ≤ (SimpleFunc.const α (C : ℝ≥0∞)).lintegral (μ.restrict s) + ε₁ := by
gcongr
exact SimpleFunc.lintegral_mono (fun x ↦ ENNReal.coe_le_coe.2 (hC x)) le_rfl
_ = C * μ s + ε₁ := by
simp only [← SimpleFunc.lintegral_eq_lintegral, coe_const, lintegral_const,
Measure.restrict_apply, MeasurableSet.univ, univ_inter, Function.const]
_ ≤ C * ((ε₂ - ε₁) / C) + ε₁ := by gcongr
_ ≤ ε₂ - ε₁ + ε₁ := by gcongr; apply mul_div_le
_ = ε₂ := tsub_add_cancel_of_le hε₁₂.le
#align measure_theory.exists_pos_set_lintegral_lt_of_measure_lt MeasureTheory.exists_pos_set_lintegral_lt_of_measure_lt
theorem tendsto_set_lintegral_zero {ι} {f : α → ℝ≥0∞} (h : ∫⁻ x, f x ∂μ ≠ ∞) {l : Filter ι}
{s : ι → Set α} (hl : Tendsto (μ ∘ s) l (𝓝 0)) :
Tendsto (fun i => ∫⁻ x in s i, f x ∂μ) l (𝓝 0) := by
simp only [ENNReal.nhds_zero, tendsto_iInf, tendsto_principal, mem_Iio,
← pos_iff_ne_zero] at hl ⊢
intro ε ε0
rcases exists_pos_set_lintegral_lt_of_measure_lt h ε0.ne' with ⟨δ, δ0, hδ⟩
exact (hl δ δ0).mono fun i => hδ _
#align measure_theory.tendsto_set_lintegral_zero MeasureTheory.tendsto_set_lintegral_zero
theorem le_lintegral_add (f g : α → ℝ≥0∞) :
∫⁻ a, f a ∂μ + ∫⁻ a, g a ∂μ ≤ ∫⁻ a, f a + g a ∂μ := by
simp only [lintegral]
refine ENNReal.biSup_add_biSup_le' (p := fun h : α →ₛ ℝ≥0∞ => h ≤ f)
(q := fun h : α →ₛ ℝ≥0∞ => h ≤ g) ⟨0, zero_le f⟩ ⟨0, zero_le g⟩ fun f' hf' g' hg' => ?_
exact le_iSup₂_of_le (f' + g') (add_le_add hf' hg') (add_lintegral _ _).ge
#align measure_theory.le_lintegral_add MeasureTheory.le_lintegral_add
-- Use stronger lemmas `lintegral_add_left`/`lintegral_add_right` instead
theorem lintegral_add_aux {f g : α → ℝ≥0∞} (hf : Measurable f) (hg : Measurable g) :
∫⁻ a, f a + g a ∂μ = ∫⁻ a, f a ∂μ + ∫⁻ a, g a ∂μ :=
calc
∫⁻ a, f a + g a ∂μ =
∫⁻ a, (⨆ n, (eapprox f n : α → ℝ≥0∞) a) + ⨆ n, (eapprox g n : α → ℝ≥0∞) a ∂μ := by
simp only [iSup_eapprox_apply, hf, hg]
_ = ∫⁻ a, ⨆ n, (eapprox f n + eapprox g n : α → ℝ≥0∞) a ∂μ := by
congr; funext a
rw [ENNReal.iSup_add_iSup_of_monotone]
· simp only [Pi.add_apply]
· intro i j h
exact monotone_eapprox _ h a
· intro i j h
exact monotone_eapprox _ h a
_ = ⨆ n, (eapprox f n).lintegral μ + (eapprox g n).lintegral μ := by
rw [lintegral_iSup]
· congr
funext n
rw [← SimpleFunc.add_lintegral, ← SimpleFunc.lintegral_eq_lintegral]
simp only [Pi.add_apply, SimpleFunc.coe_add]
· measurability
· intro i j h a
dsimp
gcongr <;> exact monotone_eapprox _ h _
_ = (⨆ n, (eapprox f n).lintegral μ) + ⨆ n, (eapprox g n).lintegral μ := by
refine (ENNReal.iSup_add_iSup_of_monotone ?_ ?_).symm <;>
· intro i j h
exact SimpleFunc.lintegral_mono (monotone_eapprox _ h) le_rfl
_ = ∫⁻ a, f a ∂μ + ∫⁻ a, g a ∂μ := by
rw [lintegral_eq_iSup_eapprox_lintegral hf, lintegral_eq_iSup_eapprox_lintegral hg]
#align measure_theory.lintegral_add_aux MeasureTheory.lintegral_add_aux
@[simp]
theorem lintegral_add_left {f : α → ℝ≥0∞} (hf : Measurable f) (g : α → ℝ≥0∞) :
∫⁻ a, f a + g a ∂μ = ∫⁻ a, f a ∂μ + ∫⁻ a, g a ∂μ := by
refine le_antisymm ?_ (le_lintegral_add _ _)
rcases exists_measurable_le_lintegral_eq μ fun a => f a + g a with ⟨φ, hφm, hφ_le, hφ_eq⟩
calc
∫⁻ a, f a + g a ∂μ = ∫⁻ a, φ a ∂μ := hφ_eq
_ ≤ ∫⁻ a, f a + (φ a - f a) ∂μ := lintegral_mono fun a => le_add_tsub
_ = ∫⁻ a, f a ∂μ + ∫⁻ a, φ a - f a ∂μ := lintegral_add_aux hf (hφm.sub hf)
_ ≤ ∫⁻ a, f a ∂μ + ∫⁻ a, g a ∂μ :=
add_le_add_left (lintegral_mono fun a => tsub_le_iff_left.2 <| hφ_le a) _
#align measure_theory.lintegral_add_left MeasureTheory.lintegral_add_left
theorem lintegral_add_left' {f : α → ℝ≥0∞} (hf : AEMeasurable f μ) (g : α → ℝ≥0∞) :
∫⁻ a, f a + g a ∂μ = ∫⁻ a, f a ∂μ + ∫⁻ a, g a ∂μ := by
rw [lintegral_congr_ae hf.ae_eq_mk, ← lintegral_add_left hf.measurable_mk,
lintegral_congr_ae (hf.ae_eq_mk.add (ae_eq_refl g))]
#align measure_theory.lintegral_add_left' MeasureTheory.lintegral_add_left'
theorem lintegral_add_right' (f : α → ℝ≥0∞) {g : α → ℝ≥0∞} (hg : AEMeasurable g μ) :
∫⁻ a, f a + g a ∂μ = ∫⁻ a, f a ∂μ + ∫⁻ a, g a ∂μ := by
simpa only [add_comm] using lintegral_add_left' hg f
#align measure_theory.lintegral_add_right' MeasureTheory.lintegral_add_right'
@[simp]
theorem lintegral_add_right (f : α → ℝ≥0∞) {g : α → ℝ≥0∞} (hg : Measurable g) :
∫⁻ a, f a + g a ∂μ = ∫⁻ a, f a ∂μ + ∫⁻ a, g a ∂μ :=
lintegral_add_right' f hg.aemeasurable
#align measure_theory.lintegral_add_right MeasureTheory.lintegral_add_right
@[simp]
theorem lintegral_smul_measure (c : ℝ≥0∞) (f : α → ℝ≥0∞) : ∫⁻ a, f a ∂c • μ = c * ∫⁻ a, f a ∂μ := by
simp only [lintegral, iSup_subtype', SimpleFunc.lintegral_smul, ENNReal.mul_iSup, smul_eq_mul]
#align measure_theory.lintegral_smul_measure MeasureTheory.lintegral_smul_measure
lemma set_lintegral_smul_measure (c : ℝ≥0∞) (f : α → ℝ≥0∞) (s : Set α) :
∫⁻ a in s, f a ∂(c • μ) = c * ∫⁻ a in s, f a ∂μ := by
rw [Measure.restrict_smul, lintegral_smul_measure]
@[simp]
theorem lintegral_sum_measure {m : MeasurableSpace α} {ι} (f : α → ℝ≥0∞) (μ : ι → Measure α) :
∫⁻ a, f a ∂Measure.sum μ = ∑' i, ∫⁻ a, f a ∂μ i := by
simp only [lintegral, iSup_subtype', SimpleFunc.lintegral_sum, ENNReal.tsum_eq_iSup_sum]
rw [iSup_comm]
congr; funext s
induction' s using Finset.induction_on with i s hi hs
· simp
simp only [Finset.sum_insert hi, ← hs]
refine (ENNReal.iSup_add_iSup ?_).symm
intro φ ψ
exact
⟨⟨φ ⊔ ψ, fun x => sup_le (φ.2 x) (ψ.2 x)⟩,
add_le_add (SimpleFunc.lintegral_mono le_sup_left le_rfl)
(Finset.sum_le_sum fun j _ => SimpleFunc.lintegral_mono le_sup_right le_rfl)⟩
#align measure_theory.lintegral_sum_measure MeasureTheory.lintegral_sum_measure
theorem hasSum_lintegral_measure {ι} {_ : MeasurableSpace α} (f : α → ℝ≥0∞) (μ : ι → Measure α) :
HasSum (fun i => ∫⁻ a, f a ∂μ i) (∫⁻ a, f a ∂Measure.sum μ) :=
(lintegral_sum_measure f μ).symm ▸ ENNReal.summable.hasSum
#align measure_theory.has_sum_lintegral_measure MeasureTheory.hasSum_lintegral_measure
@[simp]
theorem lintegral_add_measure {m : MeasurableSpace α} (f : α → ℝ≥0∞) (μ ν : Measure α) :
∫⁻ a, f a ∂(μ + ν) = ∫⁻ a, f a ∂μ + ∫⁻ a, f a ∂ν := by
simpa [tsum_fintype] using lintegral_sum_measure f fun b => cond b μ ν
#align measure_theory.lintegral_add_measure MeasureTheory.lintegral_add_measure
@[simp]
theorem lintegral_finset_sum_measure {ι} {m : MeasurableSpace α} (s : Finset ι) (f : α → ℝ≥0∞)
(μ : ι → Measure α) : ∫⁻ a, f a ∂(∑ i ∈ s, μ i) = ∑ i ∈ s, ∫⁻ a, f a ∂μ i := by
rw [← Measure.sum_coe_finset, lintegral_sum_measure, ← Finset.tsum_subtype']
simp only [Finset.coe_sort_coe]
#align measure_theory.lintegral_finset_sum_measure MeasureTheory.lintegral_finset_sum_measure
@[simp]
theorem lintegral_zero_measure {m : MeasurableSpace α} (f : α → ℝ≥0∞) :
∫⁻ a, f a ∂(0 : Measure α) = 0 := by
simp [lintegral]
#align measure_theory.lintegral_zero_measure MeasureTheory.lintegral_zero_measure
@[simp]
theorem lintegral_of_isEmpty {α} [MeasurableSpace α] [IsEmpty α] (μ : Measure α) (f : α → ℝ≥0∞) :
∫⁻ x, f x ∂μ = 0 := by
have : Subsingleton (Measure α) := inferInstance
convert lintegral_zero_measure f
theorem set_lintegral_empty (f : α → ℝ≥0∞) : ∫⁻ x in ∅, f x ∂μ = 0 := by
rw [Measure.restrict_empty, lintegral_zero_measure]
#align measure_theory.set_lintegral_empty MeasureTheory.set_lintegral_empty
theorem set_lintegral_univ (f : α → ℝ≥0∞) : ∫⁻ x in univ, f x ∂μ = ∫⁻ x, f x ∂μ := by
rw [Measure.restrict_univ]
#align measure_theory.set_lintegral_univ MeasureTheory.set_lintegral_univ
theorem set_lintegral_measure_zero (s : Set α) (f : α → ℝ≥0∞) (hs' : μ s = 0) :
∫⁻ x in s, f x ∂μ = 0 := by
convert lintegral_zero_measure _
exact Measure.restrict_eq_zero.2 hs'
#align measure_theory.set_lintegral_measure_zero MeasureTheory.set_lintegral_measure_zero
theorem lintegral_finset_sum' (s : Finset β) {f : β → α → ℝ≥0∞}
(hf : ∀ b ∈ s, AEMeasurable (f b) μ) :
∫⁻ a, ∑ b ∈ s, f b a ∂μ = ∑ b ∈ s, ∫⁻ a, f b a ∂μ := by
induction' s using Finset.induction_on with a s has ih
· simp
· simp only [Finset.sum_insert has]
rw [Finset.forall_mem_insert] at hf
rw [lintegral_add_left' hf.1, ih hf.2]
#align measure_theory.lintegral_finset_sum' MeasureTheory.lintegral_finset_sum'
theorem lintegral_finset_sum (s : Finset β) {f : β → α → ℝ≥0∞} (hf : ∀ b ∈ s, Measurable (f b)) :
∫⁻ a, ∑ b ∈ s, f b a ∂μ = ∑ b ∈ s, ∫⁻ a, f b a ∂μ :=
lintegral_finset_sum' s fun b hb => (hf b hb).aemeasurable
#align measure_theory.lintegral_finset_sum MeasureTheory.lintegral_finset_sum
@[simp]
theorem lintegral_const_mul (r : ℝ≥0∞) {f : α → ℝ≥0∞} (hf : Measurable f) :
∫⁻ a, r * f a ∂μ = r * ∫⁻ a, f a ∂μ :=
calc
∫⁻ a, r * f a ∂μ = ∫⁻ a, ⨆ n, (const α r * eapprox f n) a ∂μ := by
congr
funext a
rw [← iSup_eapprox_apply f hf, ENNReal.mul_iSup]
simp
_ = ⨆ n, r * (eapprox f n).lintegral μ := by
rw [lintegral_iSup]
· congr
funext n
rw [← SimpleFunc.const_mul_lintegral, ← SimpleFunc.lintegral_eq_lintegral]
· intro n
exact SimpleFunc.measurable _
· intro i j h a
exact mul_le_mul_left' (monotone_eapprox _ h _) _
_ = r * ∫⁻ a, f a ∂μ := by rw [← ENNReal.mul_iSup, lintegral_eq_iSup_eapprox_lintegral hf]
#align measure_theory.lintegral_const_mul MeasureTheory.lintegral_const_mul
theorem lintegral_const_mul'' (r : ℝ≥0∞) {f : α → ℝ≥0∞} (hf : AEMeasurable f μ) :
∫⁻ a, r * f a ∂μ = r * ∫⁻ a, f a ∂μ := by
have A : ∫⁻ a, f a ∂μ = ∫⁻ a, hf.mk f a ∂μ := lintegral_congr_ae hf.ae_eq_mk
have B : ∫⁻ a, r * f a ∂μ = ∫⁻ a, r * hf.mk f a ∂μ :=
lintegral_congr_ae (EventuallyEq.fun_comp hf.ae_eq_mk _)
rw [A, B, lintegral_const_mul _ hf.measurable_mk]
#align measure_theory.lintegral_const_mul'' MeasureTheory.lintegral_const_mul''
theorem lintegral_const_mul_le (r : ℝ≥0∞) (f : α → ℝ≥0∞) :
r * ∫⁻ a, f a ∂μ ≤ ∫⁻ a, r * f a ∂μ := by
rw [lintegral, ENNReal.mul_iSup]
refine iSup_le fun s => ?_
rw [ENNReal.mul_iSup, iSup_le_iff]
intro hs
rw [← SimpleFunc.const_mul_lintegral, lintegral]
refine le_iSup_of_le (const α r * s) (le_iSup_of_le (fun x => ?_) le_rfl)
exact mul_le_mul_left' (hs x) _
#align measure_theory.lintegral_const_mul_le MeasureTheory.lintegral_const_mul_le
theorem lintegral_const_mul' (r : ℝ≥0∞) (f : α → ℝ≥0∞) (hr : r ≠ ∞) :
∫⁻ a, r * f a ∂μ = r * ∫⁻ a, f a ∂μ := by
by_cases h : r = 0
· simp [h]
apply le_antisymm _ (lintegral_const_mul_le r f)
have rinv : r * r⁻¹ = 1 := ENNReal.mul_inv_cancel h hr
have rinv' : r⁻¹ * r = 1 := by
rw [mul_comm]
exact rinv
have := lintegral_const_mul_le (μ := μ) r⁻¹ fun x => r * f x
simp? [(mul_assoc _ _ _).symm, rinv'] at this says
simp only [(mul_assoc _ _ _).symm, rinv', one_mul] at this
simpa [(mul_assoc _ _ _).symm, rinv] using mul_le_mul_left' this r
#align measure_theory.lintegral_const_mul' MeasureTheory.lintegral_const_mul'
theorem lintegral_mul_const (r : ℝ≥0∞) {f : α → ℝ≥0∞} (hf : Measurable f) :
∫⁻ a, f a * r ∂μ = (∫⁻ a, f a ∂μ) * r := by simp_rw [mul_comm, lintegral_const_mul r hf]
#align measure_theory.lintegral_mul_const MeasureTheory.lintegral_mul_const
theorem lintegral_mul_const'' (r : ℝ≥0∞) {f : α → ℝ≥0∞} (hf : AEMeasurable f μ) :
∫⁻ a, f a * r ∂μ = (∫⁻ a, f a ∂μ) * r := by simp_rw [mul_comm, lintegral_const_mul'' r hf]
#align measure_theory.lintegral_mul_const'' MeasureTheory.lintegral_mul_const''
theorem lintegral_mul_const_le (r : ℝ≥0∞) (f : α → ℝ≥0∞) :
(∫⁻ a, f a ∂μ) * r ≤ ∫⁻ a, f a * r ∂μ := by
simp_rw [mul_comm, lintegral_const_mul_le r f]
#align measure_theory.lintegral_mul_const_le MeasureTheory.lintegral_mul_const_le
theorem lintegral_mul_const' (r : ℝ≥0∞) (f : α → ℝ≥0∞) (hr : r ≠ ∞) :
∫⁻ a, f a * r ∂μ = (∫⁻ a, f a ∂μ) * r := by simp_rw [mul_comm, lintegral_const_mul' r f hr]
#align measure_theory.lintegral_mul_const' MeasureTheory.lintegral_mul_const'
theorem lintegral_lintegral_mul {β} [MeasurableSpace β] {ν : Measure β} {f : α → ℝ≥0∞}
{g : β → ℝ≥0∞} (hf : AEMeasurable f μ) (hg : AEMeasurable g ν) :
∫⁻ x, ∫⁻ y, f x * g y ∂ν ∂μ = (∫⁻ x, f x ∂μ) * ∫⁻ y, g y ∂ν := by
simp [lintegral_const_mul'' _ hg, lintegral_mul_const'' _ hf]
#align measure_theory.lintegral_lintegral_mul MeasureTheory.lintegral_lintegral_mul
-- TODO: Need a better way of rewriting inside of an integral
theorem lintegral_rw₁ {f f' : α → β} (h : f =ᵐ[μ] f') (g : β → ℝ≥0∞) :
∫⁻ a, g (f a) ∂μ = ∫⁻ a, g (f' a) ∂μ :=
lintegral_congr_ae <| h.mono fun a h => by dsimp only; rw [h]
#align measure_theory.lintegral_rw₁ MeasureTheory.lintegral_rw₁
-- TODO: Need a better way of rewriting inside of an integral
theorem lintegral_rw₂ {f₁ f₁' : α → β} {f₂ f₂' : α → γ} (h₁ : f₁ =ᵐ[μ] f₁') (h₂ : f₂ =ᵐ[μ] f₂')
(g : β → γ → ℝ≥0∞) : ∫⁻ a, g (f₁ a) (f₂ a) ∂μ = ∫⁻ a, g (f₁' a) (f₂' a) ∂μ :=
lintegral_congr_ae <| h₁.mp <| h₂.mono fun _ h₂ h₁ => by dsimp only; rw [h₁, h₂]
#align measure_theory.lintegral_rw₂ MeasureTheory.lintegral_rw₂
theorem lintegral_indicator_le (f : α → ℝ≥0∞) (s : Set α) :
∫⁻ a, s.indicator f a ∂μ ≤ ∫⁻ a in s, f a ∂μ := by
simp only [lintegral]
apply iSup_le (fun g ↦ (iSup_le (fun hg ↦ ?_)))
have : g ≤ f := hg.trans (indicator_le_self s f)
refine le_iSup_of_le g (le_iSup_of_le this (le_of_eq ?_))
rw [lintegral_restrict, SimpleFunc.lintegral]
congr with t
by_cases H : t = 0
· simp [H]
congr with x
simp only [mem_preimage, mem_singleton_iff, mem_inter_iff, iff_self_and]
rintro rfl
contrapose! H
simpa [H] using hg x
@[simp]
theorem lintegral_indicator (f : α → ℝ≥0∞) {s : Set α} (hs : MeasurableSet s) :
∫⁻ a, s.indicator f a ∂μ = ∫⁻ a in s, f a ∂μ := by
apply le_antisymm (lintegral_indicator_le f s)
simp only [lintegral, ← restrict_lintegral_eq_lintegral_restrict _ hs, iSup_subtype']
refine iSup_mono' (Subtype.forall.2 fun φ hφ => ?_)
refine ⟨⟨φ.restrict s, fun x => ?_⟩, le_rfl⟩
simp [hφ x, hs, indicator_le_indicator]
#align measure_theory.lintegral_indicator MeasureTheory.lintegral_indicator
theorem lintegral_indicator₀ (f : α → ℝ≥0∞) {s : Set α} (hs : NullMeasurableSet s μ) :
∫⁻ a, s.indicator f a ∂μ = ∫⁻ a in s, f a ∂μ := by
rw [← lintegral_congr_ae (indicator_ae_eq_of_ae_eq_set hs.toMeasurable_ae_eq),
lintegral_indicator _ (measurableSet_toMeasurable _ _),
Measure.restrict_congr_set hs.toMeasurable_ae_eq]
#align measure_theory.lintegral_indicator₀ MeasureTheory.lintegral_indicator₀
theorem lintegral_indicator_const_le (s : Set α) (c : ℝ≥0∞) :
∫⁻ a, s.indicator (fun _ => c) a ∂μ ≤ c * μ s :=
(lintegral_indicator_le _ _).trans (set_lintegral_const s c).le
theorem lintegral_indicator_const₀ {s : Set α} (hs : NullMeasurableSet s μ) (c : ℝ≥0∞) :
∫⁻ a, s.indicator (fun _ => c) a ∂μ = c * μ s := by
rw [lintegral_indicator₀ _ hs, set_lintegral_const]
theorem lintegral_indicator_const {s : Set α} (hs : MeasurableSet s) (c : ℝ≥0∞) :
∫⁻ a, s.indicator (fun _ => c) a ∂μ = c * μ s :=
lintegral_indicator_const₀ hs.nullMeasurableSet c
#align measure_theory.lintegral_indicator_const MeasureTheory.lintegral_indicator_const
theorem set_lintegral_eq_const {f : α → ℝ≥0∞} (hf : Measurable f) (r : ℝ≥0∞) :
∫⁻ x in { x | f x = r }, f x ∂μ = r * μ { x | f x = r } := by
have : ∀ᵐ x ∂μ, x ∈ { x | f x = r } → f x = r := ae_of_all μ fun _ hx => hx
rw [set_lintegral_congr_fun _ this]
· rw [lintegral_const, Measure.restrict_apply MeasurableSet.univ, Set.univ_inter]
· exact hf (measurableSet_singleton r)
#align measure_theory.set_lintegral_eq_const MeasureTheory.set_lintegral_eq_const
theorem lintegral_indicator_one_le (s : Set α) : ∫⁻ a, s.indicator 1 a ∂μ ≤ μ s :=
(lintegral_indicator_const_le _ _).trans <| (one_mul _).le
@[simp]
theorem lintegral_indicator_one₀ (hs : NullMeasurableSet s μ) : ∫⁻ a, s.indicator 1 a ∂μ = μ s :=
(lintegral_indicator_const₀ hs _).trans <| one_mul _
@[simp]
theorem lintegral_indicator_one (hs : MeasurableSet s) : ∫⁻ a, s.indicator 1 a ∂μ = μ s :=
(lintegral_indicator_const hs _).trans <| one_mul _
#align measure_theory.lintegral_indicator_one MeasureTheory.lintegral_indicator_one
theorem lintegral_add_mul_meas_add_le_le_lintegral {f g : α → ℝ≥0∞} (hle : f ≤ᵐ[μ] g)
(hg : AEMeasurable g μ) (ε : ℝ≥0∞) :
∫⁻ a, f a ∂μ + ε * μ { x | f x + ε ≤ g x } ≤ ∫⁻ a, g a ∂μ := by
rcases exists_measurable_le_lintegral_eq μ f with ⟨φ, hφm, hφ_le, hφ_eq⟩
calc
∫⁻ x, f x ∂μ + ε * μ { x | f x + ε ≤ g x } = ∫⁻ x, φ x ∂μ + ε * μ { x | f x + ε ≤ g x } := by
rw [hφ_eq]
_ ≤ ∫⁻ x, φ x ∂μ + ε * μ { x | φ x + ε ≤ g x } := by
gcongr
exact fun x => (add_le_add_right (hφ_le _) _).trans
_ = ∫⁻ x, φ x + indicator { x | φ x + ε ≤ g x } (fun _ => ε) x ∂μ := by
rw [lintegral_add_left hφm, lintegral_indicator₀, set_lintegral_const]
exact measurableSet_le (hφm.nullMeasurable.measurable'.add_const _) hg.nullMeasurable
_ ≤ ∫⁻ x, g x ∂μ := lintegral_mono_ae (hle.mono fun x hx₁ => ?_)
simp only [indicator_apply]; split_ifs with hx₂
exacts [hx₂, (add_zero _).trans_le <| (hφ_le x).trans hx₁]
#align measure_theory.lintegral_add_mul_meas_add_le_le_lintegral MeasureTheory.lintegral_add_mul_meas_add_le_le_lintegral
theorem mul_meas_ge_le_lintegral₀ {f : α → ℝ≥0∞} (hf : AEMeasurable f μ) (ε : ℝ≥0∞) :
ε * μ { x | ε ≤ f x } ≤ ∫⁻ a, f a ∂μ := by
simpa only [lintegral_zero, zero_add] using
lintegral_add_mul_meas_add_le_le_lintegral (ae_of_all _ fun x => zero_le (f x)) hf ε
#align measure_theory.mul_meas_ge_le_lintegral₀ MeasureTheory.mul_meas_ge_le_lintegral₀
theorem mul_meas_ge_le_lintegral {f : α → ℝ≥0∞} (hf : Measurable f) (ε : ℝ≥0∞) :
ε * μ { x | ε ≤ f x } ≤ ∫⁻ a, f a ∂μ :=
mul_meas_ge_le_lintegral₀ hf.aemeasurable ε
#align measure_theory.mul_meas_ge_le_lintegral MeasureTheory.mul_meas_ge_le_lintegral
lemma meas_le_lintegral₀ {f : α → ℝ≥0∞} (hf : AEMeasurable f μ)
{s : Set α} (hs : ∀ x ∈ s, 1 ≤ f x) : μ s ≤ ∫⁻ a, f a ∂μ := by
apply le_trans _ (mul_meas_ge_le_lintegral₀ hf 1)
rw [one_mul]
exact measure_mono hs
lemma lintegral_le_meas {s : Set α} {f : α → ℝ≥0∞} (hf : ∀ a, f a ≤ 1) (h'f : ∀ a ∈ sᶜ, f a = 0) :
∫⁻ a, f a ∂μ ≤ μ s := by
apply (lintegral_mono (fun x ↦ ?_)).trans (lintegral_indicator_one_le s)
by_cases hx : x ∈ s
· simpa [hx] using hf x
· simpa [hx] using h'f x hx
theorem lintegral_eq_top_of_measure_eq_top_ne_zero {f : α → ℝ≥0∞} (hf : AEMeasurable f μ)
(hμf : μ {x | f x = ∞} ≠ 0) : ∫⁻ x, f x ∂μ = ∞ :=
eq_top_iff.mpr <|
calc
∞ = ∞ * μ { x | ∞ ≤ f x } := by simp [mul_eq_top, hμf]
_ ≤ ∫⁻ x, f x ∂μ := mul_meas_ge_le_lintegral₀ hf ∞
#align measure_theory.lintegral_eq_top_of_measure_eq_top_ne_zero MeasureTheory.lintegral_eq_top_of_measure_eq_top_ne_zero
theorem setLintegral_eq_top_of_measure_eq_top_ne_zero (hf : AEMeasurable f (μ.restrict s))
(hμf : μ ({x ∈ s | f x = ∞}) ≠ 0) : ∫⁻ x in s, f x ∂μ = ∞ :=
lintegral_eq_top_of_measure_eq_top_ne_zero hf <|
mt (eq_bot_mono <| by rw [← setOf_inter_eq_sep]; exact Measure.le_restrict_apply _ _) hμf
#align measure_theory.set_lintegral_eq_top_of_measure_eq_top_ne_zero MeasureTheory.setLintegral_eq_top_of_measure_eq_top_ne_zero
theorem measure_eq_top_of_lintegral_ne_top (hf : AEMeasurable f μ) (hμf : ∫⁻ x, f x ∂μ ≠ ∞) :
μ {x | f x = ∞} = 0 :=
of_not_not fun h => hμf <| lintegral_eq_top_of_measure_eq_top_ne_zero hf h
#align measure_theory.measure_eq_top_of_lintegral_ne_top MeasureTheory.measure_eq_top_of_lintegral_ne_top
theorem measure_eq_top_of_setLintegral_ne_top (hf : AEMeasurable f (μ.restrict s))
(hμf : ∫⁻ x in s, f x ∂μ ≠ ∞) : μ ({x ∈ s | f x = ∞}) = 0 :=
of_not_not fun h => hμf <| setLintegral_eq_top_of_measure_eq_top_ne_zero hf h
#align measure_theory.measure_eq_top_of_set_lintegral_ne_top MeasureTheory.measure_eq_top_of_setLintegral_ne_top
theorem meas_ge_le_lintegral_div {f : α → ℝ≥0∞} (hf : AEMeasurable f μ) {ε : ℝ≥0∞} (hε : ε ≠ 0)
(hε' : ε ≠ ∞) : μ { x | ε ≤ f x } ≤ (∫⁻ a, f a ∂μ) / ε :=
(ENNReal.le_div_iff_mul_le (Or.inl hε) (Or.inl hε')).2 <| by
rw [mul_comm]
exact mul_meas_ge_le_lintegral₀ hf ε
#align measure_theory.meas_ge_le_lintegral_div MeasureTheory.meas_ge_le_lintegral_div
theorem ae_eq_of_ae_le_of_lintegral_le {f g : α → ℝ≥0∞} (hfg : f ≤ᵐ[μ] g) (hf : ∫⁻ x, f x ∂μ ≠ ∞)
(hg : AEMeasurable g μ) (hgf : ∫⁻ x, g x ∂μ ≤ ∫⁻ x, f x ∂μ) : f =ᵐ[μ] g := by
have : ∀ n : ℕ, ∀ᵐ x ∂μ, g x < f x + (n : ℝ≥0∞)⁻¹ := by
intro n
simp only [ae_iff, not_lt]
have : ∫⁻ x, f x ∂μ + (↑n)⁻¹ * μ { x : α | f x + (n : ℝ≥0∞)⁻¹ ≤ g x } ≤ ∫⁻ x, f x ∂μ :=
(lintegral_add_mul_meas_add_le_le_lintegral hfg hg n⁻¹).trans hgf
rw [(ENNReal.cancel_of_ne hf).add_le_iff_nonpos_right, nonpos_iff_eq_zero, mul_eq_zero] at this
exact this.resolve_left (ENNReal.inv_ne_zero.2 (ENNReal.natCast_ne_top _))
refine hfg.mp ((ae_all_iff.2 this).mono fun x hlt hle => hle.antisymm ?_)
suffices Tendsto (fun n : ℕ => f x + (n : ℝ≥0∞)⁻¹) atTop (𝓝 (f x)) from
ge_of_tendsto' this fun i => (hlt i).le
simpa only [inv_top, add_zero] using
tendsto_const_nhds.add (ENNReal.tendsto_inv_iff.2 ENNReal.tendsto_nat_nhds_top)
#align measure_theory.ae_eq_of_ae_le_of_lintegral_le MeasureTheory.ae_eq_of_ae_le_of_lintegral_le
@[simp]
theorem lintegral_eq_zero_iff' {f : α → ℝ≥0∞} (hf : AEMeasurable f μ) :
∫⁻ a, f a ∂μ = 0 ↔ f =ᵐ[μ] 0 :=
have : ∫⁻ _ : α, 0 ∂μ ≠ ∞ := by simp [lintegral_zero, zero_ne_top]
⟨fun h =>
(ae_eq_of_ae_le_of_lintegral_le (ae_of_all _ <| zero_le f) this hf
(h.trans lintegral_zero.symm).le).symm,
fun h => (lintegral_congr_ae h).trans lintegral_zero⟩
#align measure_theory.lintegral_eq_zero_iff' MeasureTheory.lintegral_eq_zero_iff'
@[simp]
theorem lintegral_eq_zero_iff {f : α → ℝ≥0∞} (hf : Measurable f) : ∫⁻ a, f a ∂μ = 0 ↔ f =ᵐ[μ] 0 :=
lintegral_eq_zero_iff' hf.aemeasurable
#align measure_theory.lintegral_eq_zero_iff MeasureTheory.lintegral_eq_zero_iff
theorem lintegral_pos_iff_support {f : α → ℝ≥0∞} (hf : Measurable f) :
(0 < ∫⁻ a, f a ∂μ) ↔ 0 < μ (Function.support f) := by
simp [pos_iff_ne_zero, hf, Filter.EventuallyEq, ae_iff, Function.support]
#align measure_theory.lintegral_pos_iff_support MeasureTheory.lintegral_pos_iff_support
theorem setLintegral_pos_iff {f : α → ℝ≥0∞} (hf : Measurable f) {s : Set α} :
0 < ∫⁻ a in s, f a ∂μ ↔ 0 < μ (Function.support f ∩ s) := by
rw [lintegral_pos_iff_support hf, Measure.restrict_apply (measurableSet_support hf)]
theorem lintegral_iSup_ae {f : ℕ → α → ℝ≥0∞} (hf : ∀ n, Measurable (f n))
(h_mono : ∀ n, ∀ᵐ a ∂μ, f n a ≤ f n.succ a) : ∫⁻ a, ⨆ n, f n a ∂μ = ⨆ n, ∫⁻ a, f n a ∂μ := by
let ⟨s, hs⟩ := exists_measurable_superset_of_null (ae_iff.1 (ae_all_iff.2 h_mono))
let g n a := if a ∈ s then 0 else f n a
have g_eq_f : ∀ᵐ a ∂μ, ∀ n, g n a = f n a :=
(measure_zero_iff_ae_nmem.1 hs.2.2).mono fun a ha n => if_neg ha
calc
∫⁻ a, ⨆ n, f n a ∂μ = ∫⁻ a, ⨆ n, g n a ∂μ :=
lintegral_congr_ae <| g_eq_f.mono fun a ha => by simp only [ha]
_ = ⨆ n, ∫⁻ a, g n a ∂μ :=
(lintegral_iSup (fun n => measurable_const.piecewise hs.2.1 (hf n))
(monotone_nat_of_le_succ fun n a => ?_))
_ = ⨆ n, ∫⁻ a, f n a ∂μ := by simp only [lintegral_congr_ae (g_eq_f.mono fun _a ha => ha _)]
simp only [g]
split_ifs with h
· rfl
· have := Set.not_mem_subset hs.1 h
simp only [not_forall, not_le, mem_setOf_eq, not_exists, not_lt] at this
exact this n
#align measure_theory.lintegral_supr_ae MeasureTheory.lintegral_iSup_ae
theorem lintegral_sub' {f g : α → ℝ≥0∞} (hg : AEMeasurable g μ) (hg_fin : ∫⁻ a, g a ∂μ ≠ ∞)
(h_le : g ≤ᵐ[μ] f) : ∫⁻ a, f a - g a ∂μ = ∫⁻ a, f a ∂μ - ∫⁻ a, g a ∂μ := by
refine ENNReal.eq_sub_of_add_eq hg_fin ?_
rw [← lintegral_add_right' _ hg]
exact lintegral_congr_ae (h_le.mono fun x hx => tsub_add_cancel_of_le hx)
#align measure_theory.lintegral_sub' MeasureTheory.lintegral_sub'
theorem lintegral_sub {f g : α → ℝ≥0∞} (hg : Measurable g) (hg_fin : ∫⁻ a, g a ∂μ ≠ ∞)
(h_le : g ≤ᵐ[μ] f) : ∫⁻ a, f a - g a ∂μ = ∫⁻ a, f a ∂μ - ∫⁻ a, g a ∂μ :=
lintegral_sub' hg.aemeasurable hg_fin h_le
#align measure_theory.lintegral_sub MeasureTheory.lintegral_sub
theorem lintegral_sub_le' (f g : α → ℝ≥0∞) (hf : AEMeasurable f μ) :
∫⁻ x, g x ∂μ - ∫⁻ x, f x ∂μ ≤ ∫⁻ x, g x - f x ∂μ := by
rw [tsub_le_iff_right]
by_cases hfi : ∫⁻ x, f x ∂μ = ∞
· rw [hfi, add_top]
exact le_top
· rw [← lintegral_add_right' _ hf]
gcongr
exact le_tsub_add
#align measure_theory.lintegral_sub_le' MeasureTheory.lintegral_sub_le'
theorem lintegral_sub_le (f g : α → ℝ≥0∞) (hf : Measurable f) :
∫⁻ x, g x ∂μ - ∫⁻ x, f x ∂μ ≤ ∫⁻ x, g x - f x ∂μ :=
lintegral_sub_le' f g hf.aemeasurable
#align measure_theory.lintegral_sub_le MeasureTheory.lintegral_sub_le
theorem lintegral_strict_mono_of_ae_le_of_frequently_ae_lt {f g : α → ℝ≥0∞} (hg : AEMeasurable g μ)
(hfi : ∫⁻ x, f x ∂μ ≠ ∞) (h_le : f ≤ᵐ[μ] g) (h : ∃ᵐ x ∂μ, f x ≠ g x) :
∫⁻ x, f x ∂μ < ∫⁻ x, g x ∂μ := by
contrapose! h
simp only [not_frequently, Ne, Classical.not_not]
exact ae_eq_of_ae_le_of_lintegral_le h_le hfi hg h
#align measure_theory.lintegral_strict_mono_of_ae_le_of_frequently_ae_lt MeasureTheory.lintegral_strict_mono_of_ae_le_of_frequently_ae_lt
theorem lintegral_strict_mono_of_ae_le_of_ae_lt_on {f g : α → ℝ≥0∞} (hg : AEMeasurable g μ)
(hfi : ∫⁻ x, f x ∂μ ≠ ∞) (h_le : f ≤ᵐ[μ] g) {s : Set α} (hμs : μ s ≠ 0)
(h : ∀ᵐ x ∂μ, x ∈ s → f x < g x) : ∫⁻ x, f x ∂μ < ∫⁻ x, g x ∂μ :=
lintegral_strict_mono_of_ae_le_of_frequently_ae_lt hg hfi h_le <|
((frequently_ae_mem_iff.2 hμs).and_eventually h).mono fun _x hx => (hx.2 hx.1).ne
#align measure_theory.lintegral_strict_mono_of_ae_le_of_ae_lt_on MeasureTheory.lintegral_strict_mono_of_ae_le_of_ae_lt_on
theorem lintegral_strict_mono {f g : α → ℝ≥0∞} (hμ : μ ≠ 0) (hg : AEMeasurable g μ)
(hfi : ∫⁻ x, f x ∂μ ≠ ∞) (h : ∀ᵐ x ∂μ, f x < g x) : ∫⁻ x, f x ∂μ < ∫⁻ x, g x ∂μ := by
rw [Ne, ← Measure.measure_univ_eq_zero] at hμ
refine lintegral_strict_mono_of_ae_le_of_ae_lt_on hg hfi (ae_le_of_ae_lt h) hμ ?_
simpa using h
#align measure_theory.lintegral_strict_mono MeasureTheory.lintegral_strict_mono
theorem set_lintegral_strict_mono {f g : α → ℝ≥0∞} {s : Set α} (hsm : MeasurableSet s)
(hs : μ s ≠ 0) (hg : Measurable g) (hfi : ∫⁻ x in s, f x ∂μ ≠ ∞)
(h : ∀ᵐ x ∂μ, x ∈ s → f x < g x) : ∫⁻ x in s, f x ∂μ < ∫⁻ x in s, g x ∂μ :=
lintegral_strict_mono (by simp [hs]) hg.aemeasurable hfi ((ae_restrict_iff' hsm).mpr h)
#align measure_theory.set_lintegral_strict_mono MeasureTheory.set_lintegral_strict_mono
theorem lintegral_iInf_ae {f : ℕ → α → ℝ≥0∞} (h_meas : ∀ n, Measurable (f n))
(h_mono : ∀ n : ℕ, f n.succ ≤ᵐ[μ] f n) (h_fin : ∫⁻ a, f 0 a ∂μ ≠ ∞) :
∫⁻ a, ⨅ n, f n a ∂μ = ⨅ n, ∫⁻ a, f n a ∂μ :=
have fn_le_f0 : ∫⁻ a, ⨅ n, f n a ∂μ ≤ ∫⁻ a, f 0 a ∂μ :=
lintegral_mono fun a => iInf_le_of_le 0 le_rfl
have fn_le_f0' : ⨅ n, ∫⁻ a, f n a ∂μ ≤ ∫⁻ a, f 0 a ∂μ := iInf_le_of_le 0 le_rfl
(ENNReal.sub_right_inj h_fin fn_le_f0 fn_le_f0').1 <|
show ∫⁻ a, f 0 a ∂μ - ∫⁻ a, ⨅ n, f n a ∂μ = ∫⁻ a, f 0 a ∂μ - ⨅ n, ∫⁻ a, f n a ∂μ from
calc
∫⁻ a, f 0 a ∂μ - ∫⁻ a, ⨅ n, f n a ∂μ = ∫⁻ a, f 0 a - ⨅ n, f n a ∂μ :=
(lintegral_sub (measurable_iInf h_meas)
(ne_top_of_le_ne_top h_fin <| lintegral_mono fun a => iInf_le _ _)
(ae_of_all _ fun a => iInf_le _ _)).symm
_ = ∫⁻ a, ⨆ n, f 0 a - f n a ∂μ := congr rfl (funext fun a => ENNReal.sub_iInf)
_ = ⨆ n, ∫⁻ a, f 0 a - f n a ∂μ :=
(lintegral_iSup_ae (fun n => (h_meas 0).sub (h_meas n)) fun n =>
(h_mono n).mono fun a ha => tsub_le_tsub le_rfl ha)
_ = ⨆ n, ∫⁻ a, f 0 a ∂μ - ∫⁻ a, f n a ∂μ :=
(have h_mono : ∀ᵐ a ∂μ, ∀ n : ℕ, f n.succ a ≤ f n a := ae_all_iff.2 h_mono
have h_mono : ∀ n, ∀ᵐ a ∂μ, f n a ≤ f 0 a := fun n =>
h_mono.mono fun a h => by
induction' n with n ih
· exact le_rfl
· exact le_trans (h n) ih
congr_arg iSup <|
funext fun n =>
lintegral_sub (h_meas _) (ne_top_of_le_ne_top h_fin <| lintegral_mono_ae <| h_mono n)
(h_mono n))
_ = ∫⁻ a, f 0 a ∂μ - ⨅ n, ∫⁻ a, f n a ∂μ := ENNReal.sub_iInf.symm
#align measure_theory.lintegral_infi_ae MeasureTheory.lintegral_iInf_ae
theorem lintegral_iInf {f : ℕ → α → ℝ≥0∞} (h_meas : ∀ n, Measurable (f n)) (h_anti : Antitone f)
(h_fin : ∫⁻ a, f 0 a ∂μ ≠ ∞) : ∫⁻ a, ⨅ n, f n a ∂μ = ⨅ n, ∫⁻ a, f n a ∂μ :=
lintegral_iInf_ae h_meas (fun n => ae_of_all _ <| h_anti n.le_succ) h_fin
#align measure_theory.lintegral_infi MeasureTheory.lintegral_iInf
theorem lintegral_iInf' {f : ℕ → α → ℝ≥0∞} (h_meas : ∀ n, AEMeasurable (f n) μ)
(h_anti : ∀ᵐ a ∂μ, Antitone (fun i ↦ f i a)) (h_fin : ∫⁻ a, f 0 a ∂μ ≠ ∞) :
∫⁻ a, ⨅ n, f n a ∂μ = ⨅ n, ∫⁻ a, f n a ∂μ := by
simp_rw [← iInf_apply]
let p : α → (ℕ → ℝ≥0∞) → Prop := fun _ f' => Antitone f'
have hp : ∀ᵐ x ∂μ, p x fun i => f i x := h_anti
have h_ae_seq_mono : Antitone (aeSeq h_meas p) := by
intro n m hnm x
by_cases hx : x ∈ aeSeqSet h_meas p
· exact aeSeq.prop_of_mem_aeSeqSet h_meas hx hnm
· simp only [aeSeq, hx, if_false]
exact le_rfl
rw [lintegral_congr_ae (aeSeq.iInf h_meas hp).symm]
simp_rw [iInf_apply]
rw [lintegral_iInf (aeSeq.measurable h_meas p) h_ae_seq_mono]
· congr
exact funext fun n ↦ lintegral_congr_ae (aeSeq.aeSeq_n_eq_fun_n_ae h_meas hp n)
· rwa [lintegral_congr_ae (aeSeq.aeSeq_n_eq_fun_n_ae h_meas hp 0)]
theorem lintegral_iInf_directed_of_measurable {mα : MeasurableSpace α} [Countable β]
{f : β → α → ℝ≥0∞} {μ : Measure α} (hμ : μ ≠ 0) (hf : ∀ b, Measurable (f b))
(hf_int : ∀ b, ∫⁻ a, f b a ∂μ ≠ ∞) (h_directed : Directed (· ≥ ·) f) :
∫⁻ a, ⨅ b, f b a ∂μ = ⨅ b, ∫⁻ a, f b a ∂μ := by
cases nonempty_encodable β
cases isEmpty_or_nonempty β
· simp only [iInf_of_empty, lintegral_const,
ENNReal.top_mul (Measure.measure_univ_ne_zero.mpr hμ)]
inhabit β
have : ∀ a, ⨅ b, f b a = ⨅ n, f (h_directed.sequence f n) a := by
refine fun a =>
le_antisymm (le_iInf fun n => iInf_le _ _)
(le_iInf fun b => iInf_le_of_le (Encodable.encode b + 1) ?_)
exact h_directed.sequence_le b a
-- Porting note: used `∘` below to deal with its reduced reducibility
calc
∫⁻ a, ⨅ b, f b a ∂μ
_ = ∫⁻ a, ⨅ n, (f ∘ h_directed.sequence f) n a ∂μ := by simp only [this, Function.comp_apply]
_ = ⨅ n, ∫⁻ a, (f ∘ h_directed.sequence f) n a ∂μ := by
rw [lintegral_iInf ?_ h_directed.sequence_anti]
· exact hf_int _
· exact fun n => hf _
_ = ⨅ b, ∫⁻ a, f b a ∂μ := by
refine le_antisymm (le_iInf fun b => ?_) (le_iInf fun n => ?_)
· exact iInf_le_of_le (Encodable.encode b + 1) (lintegral_mono <| h_directed.sequence_le b)
· exact iInf_le (fun b => ∫⁻ a, f b a ∂μ) _
#align lintegral_infi_directed_of_measurable MeasureTheory.lintegral_iInf_directed_of_measurable
theorem lintegral_liminf_le' {f : ℕ → α → ℝ≥0∞} (h_meas : ∀ n, AEMeasurable (f n) μ) :
∫⁻ a, liminf (fun n => f n a) atTop ∂μ ≤ liminf (fun n => ∫⁻ a, f n a ∂μ) atTop :=
calc
∫⁻ a, liminf (fun n => f n a) atTop ∂μ = ∫⁻ a, ⨆ n : ℕ, ⨅ i ≥ n, f i a ∂μ := by
simp only [liminf_eq_iSup_iInf_of_nat]
_ = ⨆ n : ℕ, ∫⁻ a, ⨅ i ≥ n, f i a ∂μ :=
(lintegral_iSup' (fun n => aemeasurable_biInf _ (to_countable _) (fun i _ ↦ h_meas i))
(ae_of_all μ fun a n m hnm => iInf_le_iInf_of_subset fun i hi => le_trans hnm hi))
_ ≤ ⨆ n : ℕ, ⨅ i ≥ n, ∫⁻ a, f i a ∂μ := iSup_mono fun n => le_iInf₂_lintegral _
_ = atTop.liminf fun n => ∫⁻ a, f n a ∂μ := Filter.liminf_eq_iSup_iInf_of_nat.symm
#align measure_theory.lintegral_liminf_le' MeasureTheory.lintegral_liminf_le'
theorem lintegral_liminf_le {f : ℕ → α → ℝ≥0∞} (h_meas : ∀ n, Measurable (f n)) :
∫⁻ a, liminf (fun n => f n a) atTop ∂μ ≤ liminf (fun n => ∫⁻ a, f n a ∂μ) atTop :=
lintegral_liminf_le' fun n => (h_meas n).aemeasurable
#align measure_theory.lintegral_liminf_le MeasureTheory.lintegral_liminf_le
theorem limsup_lintegral_le {f : ℕ → α → ℝ≥0∞} {g : α → ℝ≥0∞} (hf_meas : ∀ n, Measurable (f n))
(h_bound : ∀ n, f n ≤ᵐ[μ] g) (h_fin : ∫⁻ a, g a ∂μ ≠ ∞) :
limsup (fun n => ∫⁻ a, f n a ∂μ) atTop ≤ ∫⁻ a, limsup (fun n => f n a) atTop ∂μ :=
calc
limsup (fun n => ∫⁻ a, f n a ∂μ) atTop = ⨅ n : ℕ, ⨆ i ≥ n, ∫⁻ a, f i a ∂μ :=
limsup_eq_iInf_iSup_of_nat
_ ≤ ⨅ n : ℕ, ∫⁻ a, ⨆ i ≥ n, f i a ∂μ := iInf_mono fun n => iSup₂_lintegral_le _
_ = ∫⁻ a, ⨅ n : ℕ, ⨆ i ≥ n, f i a ∂μ := by
refine (lintegral_iInf ?_ ?_ ?_).symm
· intro n
exact measurable_biSup _ (to_countable _) (fun i _ ↦ hf_meas i)
· intro n m hnm a
exact iSup_le_iSup_of_subset fun i hi => le_trans hnm hi
· refine ne_top_of_le_ne_top h_fin (lintegral_mono_ae ?_)
refine (ae_all_iff.2 h_bound).mono fun n hn => ?_
exact iSup_le fun i => iSup_le fun _ => hn i
_ = ∫⁻ a, limsup (fun n => f n a) atTop ∂μ := by simp only [limsup_eq_iInf_iSup_of_nat]
#align measure_theory.limsup_lintegral_le MeasureTheory.limsup_lintegral_le
theorem tendsto_lintegral_of_dominated_convergence {F : ℕ → α → ℝ≥0∞} {f : α → ℝ≥0∞}
(bound : α → ℝ≥0∞) (hF_meas : ∀ n, Measurable (F n)) (h_bound : ∀ n, F n ≤ᵐ[μ] bound)
(h_fin : ∫⁻ a, bound a ∂μ ≠ ∞) (h_lim : ∀ᵐ a ∂μ, Tendsto (fun n => F n a) atTop (𝓝 (f a))) :
Tendsto (fun n => ∫⁻ a, F n a ∂μ) atTop (𝓝 (∫⁻ a, f a ∂μ)) :=
tendsto_of_le_liminf_of_limsup_le
(calc
∫⁻ a, f a ∂μ = ∫⁻ a, liminf (fun n : ℕ => F n a) atTop ∂μ :=
lintegral_congr_ae <| h_lim.mono fun a h => h.liminf_eq.symm
_ ≤ liminf (fun n => ∫⁻ a, F n a ∂μ) atTop := lintegral_liminf_le hF_meas
)
(calc
limsup (fun n : ℕ => ∫⁻ a, F n a ∂μ) atTop ≤ ∫⁻ a, limsup (fun n => F n a) atTop ∂μ :=
limsup_lintegral_le hF_meas h_bound h_fin
_ = ∫⁻ a, f a ∂μ := lintegral_congr_ae <| h_lim.mono fun a h => h.limsup_eq
)
#align measure_theory.tendsto_lintegral_of_dominated_convergence MeasureTheory.tendsto_lintegral_of_dominated_convergence
theorem tendsto_lintegral_of_dominated_convergence' {F : ℕ → α → ℝ≥0∞} {f : α → ℝ≥0∞}
(bound : α → ℝ≥0∞) (hF_meas : ∀ n, AEMeasurable (F n) μ) (h_bound : ∀ n, F n ≤ᵐ[μ] bound)
(h_fin : ∫⁻ a, bound a ∂μ ≠ ∞) (h_lim : ∀ᵐ a ∂μ, Tendsto (fun n => F n a) atTop (𝓝 (f a))) :
Tendsto (fun n => ∫⁻ a, F n a ∂μ) atTop (𝓝 (∫⁻ a, f a ∂μ)) := by
have : ∀ n, ∫⁻ a, F n a ∂μ = ∫⁻ a, (hF_meas n).mk (F n) a ∂μ := fun n =>
lintegral_congr_ae (hF_meas n).ae_eq_mk
simp_rw [this]
apply
tendsto_lintegral_of_dominated_convergence bound (fun n => (hF_meas n).measurable_mk) _ h_fin
· have : ∀ n, ∀ᵐ a ∂μ, (hF_meas n).mk (F n) a = F n a := fun n => (hF_meas n).ae_eq_mk.symm
have : ∀ᵐ a ∂μ, ∀ n, (hF_meas n).mk (F n) a = F n a := ae_all_iff.mpr this
filter_upwards [this, h_lim] with a H H'
simp_rw [H]
exact H'
· intro n
filter_upwards [h_bound n, (hF_meas n).ae_eq_mk] with a H H'
rwa [H'] at H
#align measure_theory.tendsto_lintegral_of_dominated_convergence' MeasureTheory.tendsto_lintegral_of_dominated_convergence'
theorem tendsto_lintegral_filter_of_dominated_convergence {ι} {l : Filter ι}
[l.IsCountablyGenerated] {F : ι → α → ℝ≥0∞} {f : α → ℝ≥0∞} (bound : α → ℝ≥0∞)
(hF_meas : ∀ᶠ n in l, Measurable (F n)) (h_bound : ∀ᶠ n in l, ∀ᵐ a ∂μ, F n a ≤ bound a)
(h_fin : ∫⁻ a, bound a ∂μ ≠ ∞) (h_lim : ∀ᵐ a ∂μ, Tendsto (fun n => F n a) l (𝓝 (f a))) :
Tendsto (fun n => ∫⁻ a, F n a ∂μ) l (𝓝 <| ∫⁻ a, f a ∂μ) := by
rw [tendsto_iff_seq_tendsto]
intro x xl
have hxl := by
rw [tendsto_atTop'] at xl
exact xl
have h := inter_mem hF_meas h_bound
replace h := hxl _ h
rcases h with ⟨k, h⟩
rw [← tendsto_add_atTop_iff_nat k]
refine tendsto_lintegral_of_dominated_convergence ?_ ?_ ?_ ?_ ?_
· exact bound
· intro
refine (h _ ?_).1
exact Nat.le_add_left _ _
· intro
refine (h _ ?_).2
exact Nat.le_add_left _ _
· assumption
· refine h_lim.mono fun a h_lim => ?_
apply @Tendsto.comp _ _ _ (fun n => x (n + k)) fun n => F n a
· assumption
rw [tendsto_add_atTop_iff_nat]
assumption
#align measure_theory.tendsto_lintegral_filter_of_dominated_convergence MeasureTheory.tendsto_lintegral_filter_of_dominated_convergence
theorem lintegral_tendsto_of_tendsto_of_antitone {f : ℕ → α → ℝ≥0∞} {F : α → ℝ≥0∞}
(hf : ∀ n, AEMeasurable (f n) μ) (h_anti : ∀ᵐ x ∂μ, Antitone fun n ↦ f n x)
(h0 : ∫⁻ a, f 0 a ∂μ ≠ ∞)
(h_tendsto : ∀ᵐ x ∂μ, Tendsto (fun n ↦ f n x) atTop (𝓝 (F x))) :
Tendsto (fun n ↦ ∫⁻ x, f n x ∂μ) atTop (𝓝 (∫⁻ x, F x ∂μ)) := by
have : Antitone fun n ↦ ∫⁻ x, f n x ∂μ := fun i j hij ↦
lintegral_mono_ae (h_anti.mono fun x hx ↦ hx hij)
suffices key : ∫⁻ x, F x ∂μ = ⨅ n, ∫⁻ x, f n x ∂μ by
rw [key]
exact tendsto_atTop_iInf this
rw [← lintegral_iInf' hf h_anti h0]
refine lintegral_congr_ae ?_
filter_upwards [h_anti, h_tendsto] with _ hx_anti hx_tendsto
using tendsto_nhds_unique hx_tendsto (tendsto_atTop_iInf hx_anti)
section
open Encodable
theorem lintegral_iSup_directed_of_measurable [Countable β] {f : β → α → ℝ≥0∞}
(hf : ∀ b, Measurable (f b)) (h_directed : Directed (· ≤ ·) f) :
∫⁻ a, ⨆ b, f b a ∂μ = ⨆ b, ∫⁻ a, f b a ∂μ := by
cases nonempty_encodable β
cases isEmpty_or_nonempty β
· simp [iSup_of_empty]
inhabit β
have : ∀ a, ⨆ b, f b a = ⨆ n, f (h_directed.sequence f n) a := by
intro a
refine le_antisymm (iSup_le fun b => ?_) (iSup_le fun n => le_iSup (fun n => f n a) _)
exact le_iSup_of_le (encode b + 1) (h_directed.le_sequence b a)
calc
∫⁻ a, ⨆ b, f b a ∂μ = ∫⁻ a, ⨆ n, f (h_directed.sequence f n) a ∂μ := by simp only [this]
_ = ⨆ n, ∫⁻ a, f (h_directed.sequence f n) a ∂μ :=
(lintegral_iSup (fun n => hf _) h_directed.sequence_mono)
_ = ⨆ b, ∫⁻ a, f b a ∂μ := by
refine le_antisymm (iSup_le fun n => ?_) (iSup_le fun b => ?_)
· exact le_iSup (fun b => ∫⁻ a, f b a ∂μ) _
· exact le_iSup_of_le (encode b + 1) (lintegral_mono <| h_directed.le_sequence b)
#align measure_theory.lintegral_supr_directed_of_measurable MeasureTheory.lintegral_iSup_directed_of_measurable
theorem lintegral_iSup_directed [Countable β] {f : β → α → ℝ≥0∞} (hf : ∀ b, AEMeasurable (f b) μ)
(h_directed : Directed (· ≤ ·) f) : ∫⁻ a, ⨆ b, f b a ∂μ = ⨆ b, ∫⁻ a, f b a ∂μ := by
simp_rw [← iSup_apply]
let p : α → (β → ENNReal) → Prop := fun x f' => Directed LE.le f'
have hp : ∀ᵐ x ∂μ, p x fun i => f i x := by
filter_upwards [] with x i j
obtain ⟨z, hz₁, hz₂⟩ := h_directed i j
exact ⟨z, hz₁ x, hz₂ x⟩
have h_ae_seq_directed : Directed LE.le (aeSeq hf p) := by
intro b₁ b₂
obtain ⟨z, hz₁, hz₂⟩ := h_directed b₁ b₂
refine ⟨z, ?_, ?_⟩ <;>
· intro x
by_cases hx : x ∈ aeSeqSet hf p
· repeat rw [aeSeq.aeSeq_eq_fun_of_mem_aeSeqSet hf hx]
apply_rules [hz₁, hz₂]
· simp only [aeSeq, hx, if_false]
exact le_rfl
convert lintegral_iSup_directed_of_measurable (aeSeq.measurable hf p) h_ae_seq_directed using 1
· simp_rw [← iSup_apply]
rw [lintegral_congr_ae (aeSeq.iSup hf hp).symm]
· congr 1
ext1 b
rw [lintegral_congr_ae]
apply EventuallyEq.symm
exact aeSeq.aeSeq_n_eq_fun_n_ae hf hp _
#align measure_theory.lintegral_supr_directed MeasureTheory.lintegral_iSup_directed
end
theorem lintegral_tsum [Countable β] {f : β → α → ℝ≥0∞} (hf : ∀ i, AEMeasurable (f i) μ) :
∫⁻ a, ∑' i, f i a ∂μ = ∑' i, ∫⁻ a, f i a ∂μ := by
simp only [ENNReal.tsum_eq_iSup_sum]
rw [lintegral_iSup_directed]
· simp [lintegral_finset_sum' _ fun i _ => hf i]
· intro b
exact Finset.aemeasurable_sum _ fun i _ => hf i
· intro s t
use s ∪ t
constructor
· exact fun a => Finset.sum_le_sum_of_subset Finset.subset_union_left
· exact fun a => Finset.sum_le_sum_of_subset Finset.subset_union_right
#align measure_theory.lintegral_tsum MeasureTheory.lintegral_tsum
open Measure
theorem lintegral_iUnion₀ [Countable β] {s : β → Set α} (hm : ∀ i, NullMeasurableSet (s i) μ)
(hd : Pairwise (AEDisjoint μ on s)) (f : α → ℝ≥0∞) :
∫⁻ a in ⋃ i, s i, f a ∂μ = ∑' i, ∫⁻ a in s i, f a ∂μ := by
simp only [Measure.restrict_iUnion_ae hd hm, lintegral_sum_measure]
#align measure_theory.lintegral_Union₀ MeasureTheory.lintegral_iUnion₀
theorem lintegral_iUnion [Countable β] {s : β → Set α} (hm : ∀ i, MeasurableSet (s i))
(hd : Pairwise (Disjoint on s)) (f : α → ℝ≥0∞) :
∫⁻ a in ⋃ i, s i, f a ∂μ = ∑' i, ∫⁻ a in s i, f a ∂μ :=
lintegral_iUnion₀ (fun i => (hm i).nullMeasurableSet) hd.aedisjoint f
#align measure_theory.lintegral_Union MeasureTheory.lintegral_iUnion
theorem lintegral_biUnion₀ {t : Set β} {s : β → Set α} (ht : t.Countable)
(hm : ∀ i ∈ t, NullMeasurableSet (s i) μ) (hd : t.Pairwise (AEDisjoint μ on s)) (f : α → ℝ≥0∞) :
∫⁻ a in ⋃ i ∈ t, s i, f a ∂μ = ∑' i : t, ∫⁻ a in s i, f a ∂μ := by
haveI := ht.toEncodable
rw [biUnion_eq_iUnion, lintegral_iUnion₀ (SetCoe.forall'.1 hm) (hd.subtype _ _)]
#align measure_theory.lintegral_bUnion₀ MeasureTheory.lintegral_biUnion₀
theorem lintegral_biUnion {t : Set β} {s : β → Set α} (ht : t.Countable)
(hm : ∀ i ∈ t, MeasurableSet (s i)) (hd : t.PairwiseDisjoint s) (f : α → ℝ≥0∞) :
∫⁻ a in ⋃ i ∈ t, s i, f a ∂μ = ∑' i : t, ∫⁻ a in s i, f a ∂μ :=
lintegral_biUnion₀ ht (fun i hi => (hm i hi).nullMeasurableSet) hd.aedisjoint f
#align measure_theory.lintegral_bUnion MeasureTheory.lintegral_biUnion
theorem lintegral_biUnion_finset₀ {s : Finset β} {t : β → Set α}
(hd : Set.Pairwise (↑s) (AEDisjoint μ on t)) (hm : ∀ b ∈ s, NullMeasurableSet (t b) μ)
(f : α → ℝ≥0∞) : ∫⁻ a in ⋃ b ∈ s, t b, f a ∂μ = ∑ b ∈ s, ∫⁻ a in t b, f a ∂μ := by
simp only [← Finset.mem_coe, lintegral_biUnion₀ s.countable_toSet hm hd, ← Finset.tsum_subtype']
#align measure_theory.lintegral_bUnion_finset₀ MeasureTheory.lintegral_biUnion_finset₀
theorem lintegral_biUnion_finset {s : Finset β} {t : β → Set α} (hd : Set.PairwiseDisjoint (↑s) t)
(hm : ∀ b ∈ s, MeasurableSet (t b)) (f : α → ℝ≥0∞) :
∫⁻ a in ⋃ b ∈ s, t b, f a ∂μ = ∑ b ∈ s, ∫⁻ a in t b, f a ∂μ :=
lintegral_biUnion_finset₀ hd.aedisjoint (fun b hb => (hm b hb).nullMeasurableSet) f
#align measure_theory.lintegral_bUnion_finset MeasureTheory.lintegral_biUnion_finset
theorem lintegral_iUnion_le [Countable β] (s : β → Set α) (f : α → ℝ≥0∞) :
∫⁻ a in ⋃ i, s i, f a ∂μ ≤ ∑' i, ∫⁻ a in s i, f a ∂μ := by
rw [← lintegral_sum_measure]
exact lintegral_mono' restrict_iUnion_le le_rfl
#align measure_theory.lintegral_Union_le MeasureTheory.lintegral_iUnion_le
theorem lintegral_union {f : α → ℝ≥0∞} {A B : Set α} (hB : MeasurableSet B) (hAB : Disjoint A B) :
∫⁻ a in A ∪ B, f a ∂μ = ∫⁻ a in A, f a ∂μ + ∫⁻ a in B, f a ∂μ := by
rw [restrict_union hAB hB, lintegral_add_measure]
#align measure_theory.lintegral_union MeasureTheory.lintegral_union
theorem lintegral_union_le (f : α → ℝ≥0∞) (s t : Set α) :
∫⁻ a in s ∪ t, f a ∂μ ≤ ∫⁻ a in s, f a ∂μ + ∫⁻ a in t, f a ∂μ := by
rw [← lintegral_add_measure]
exact lintegral_mono' (restrict_union_le _ _) le_rfl
theorem lintegral_inter_add_diff {B : Set α} (f : α → ℝ≥0∞) (A : Set α) (hB : MeasurableSet B) :
∫⁻ x in A ∩ B, f x ∂μ + ∫⁻ x in A \ B, f x ∂μ = ∫⁻ x in A, f x ∂μ := by
rw [← lintegral_add_measure, restrict_inter_add_diff _ hB]
#align measure_theory.lintegral_inter_add_diff MeasureTheory.lintegral_inter_add_diff
theorem lintegral_add_compl (f : α → ℝ≥0∞) {A : Set α} (hA : MeasurableSet A) :
∫⁻ x in A, f x ∂μ + ∫⁻ x in Aᶜ, f x ∂μ = ∫⁻ x, f x ∂μ := by
rw [← lintegral_add_measure, Measure.restrict_add_restrict_compl hA]
#align measure_theory.lintegral_add_compl MeasureTheory.lintegral_add_compl
theorem lintegral_max {f g : α → ℝ≥0∞} (hf : Measurable f) (hg : Measurable g) :
∫⁻ x, max (f x) (g x) ∂μ =
∫⁻ x in { x | f x ≤ g x }, g x ∂μ + ∫⁻ x in { x | g x < f x }, f x ∂μ := by
have hm : MeasurableSet { x | f x ≤ g x } := measurableSet_le hf hg
rw [← lintegral_add_compl (fun x => max (f x) (g x)) hm]
simp only [← compl_setOf, ← not_le]
refine congr_arg₂ (· + ·) (set_lintegral_congr_fun hm ?_) (set_lintegral_congr_fun hm.compl ?_)
exacts [ae_of_all _ fun x => max_eq_right (a := f x) (b := g x),
ae_of_all _ fun x (hx : ¬ f x ≤ g x) => max_eq_left (not_le.1 hx).le]
#align measure_theory.lintegral_max MeasureTheory.lintegral_max
theorem set_lintegral_max {f g : α → ℝ≥0∞} (hf : Measurable f) (hg : Measurable g) (s : Set α) :
∫⁻ x in s, max (f x) (g x) ∂μ =
∫⁻ x in s ∩ { x | f x ≤ g x }, g x ∂μ + ∫⁻ x in s ∩ { x | g x < f x }, f x ∂μ := by
rw [lintegral_max hf hg, restrict_restrict, restrict_restrict, inter_comm s, inter_comm s]
exacts [measurableSet_lt hg hf, measurableSet_le hf hg]
#align measure_theory.set_lintegral_max MeasureTheory.set_lintegral_max
theorem lintegral_map {mβ : MeasurableSpace β} {f : β → ℝ≥0∞} {g : α → β} (hf : Measurable f)
(hg : Measurable g) : ∫⁻ a, f a ∂map g μ = ∫⁻ a, f (g a) ∂μ := by
erw [lintegral_eq_iSup_eapprox_lintegral hf, lintegral_eq_iSup_eapprox_lintegral (hf.comp hg)]
congr with n : 1
convert SimpleFunc.lintegral_map _ hg
ext1 x; simp only [eapprox_comp hf hg, coe_comp]
#align measure_theory.lintegral_map MeasureTheory.lintegral_map
theorem lintegral_map' {mβ : MeasurableSpace β} {f : β → ℝ≥0∞} {g : α → β}
(hf : AEMeasurable f (Measure.map g μ)) (hg : AEMeasurable g μ) :
∫⁻ a, f a ∂Measure.map g μ = ∫⁻ a, f (g a) ∂μ :=
calc
∫⁻ a, f a ∂Measure.map g μ = ∫⁻ a, hf.mk f a ∂Measure.map g μ :=
lintegral_congr_ae hf.ae_eq_mk
_ = ∫⁻ a, hf.mk f a ∂Measure.map (hg.mk g) μ := by
congr 1
exact Measure.map_congr hg.ae_eq_mk
_ = ∫⁻ a, hf.mk f (hg.mk g a) ∂μ := lintegral_map hf.measurable_mk hg.measurable_mk
_ = ∫⁻ a, hf.mk f (g a) ∂μ := lintegral_congr_ae <| hg.ae_eq_mk.symm.fun_comp _
_ = ∫⁻ a, f (g a) ∂μ := lintegral_congr_ae (ae_eq_comp hg hf.ae_eq_mk.symm)
#align measure_theory.lintegral_map' MeasureTheory.lintegral_map'
theorem lintegral_map_le {mβ : MeasurableSpace β} (f : β → ℝ≥0∞) {g : α → β} (hg : Measurable g) :
∫⁻ a, f a ∂Measure.map g μ ≤ ∫⁻ a, f (g a) ∂μ := by
rw [← iSup_lintegral_measurable_le_eq_lintegral, ← iSup_lintegral_measurable_le_eq_lintegral]
refine iSup₂_le fun i hi => iSup_le fun h'i => ?_
refine le_iSup₂_of_le (i ∘ g) (hi.comp hg) ?_
exact le_iSup_of_le (fun x => h'i (g x)) (le_of_eq (lintegral_map hi hg))
#align measure_theory.lintegral_map_le MeasureTheory.lintegral_map_le
theorem lintegral_comp [MeasurableSpace β] {f : β → ℝ≥0∞} {g : α → β} (hf : Measurable f)
(hg : Measurable g) : lintegral μ (f ∘ g) = ∫⁻ a, f a ∂map g μ :=
(lintegral_map hf hg).symm
#align measure_theory.lintegral_comp MeasureTheory.lintegral_comp
theorem set_lintegral_map [MeasurableSpace β] {f : β → ℝ≥0∞} {g : α → β} {s : Set β}
(hs : MeasurableSet s) (hf : Measurable f) (hg : Measurable g) :
∫⁻ y in s, f y ∂map g μ = ∫⁻ x in g ⁻¹' s, f (g x) ∂μ := by
rw [restrict_map hg hs, lintegral_map hf hg]
#align measure_theory.set_lintegral_map MeasureTheory.set_lintegral_map
theorem lintegral_indicator_const_comp {mβ : MeasurableSpace β} {f : α → β} {s : Set β}
(hf : Measurable f) (hs : MeasurableSet s) (c : ℝ≥0∞) :
∫⁻ a, s.indicator (fun _ => c) (f a) ∂μ = c * μ (f ⁻¹' s) := by
erw [lintegral_comp (measurable_const.indicator hs) hf, lintegral_indicator_const hs,
Measure.map_apply hf hs]
#align measure_theory.lintegral_indicator_const_comp MeasureTheory.lintegral_indicator_const_comp
theorem _root_.MeasurableEmbedding.lintegral_map [MeasurableSpace β] {g : α → β}
(hg : MeasurableEmbedding g) (f : β → ℝ≥0∞) : ∫⁻ a, f a ∂map g μ = ∫⁻ a, f (g a) ∂μ := by
rw [lintegral, lintegral]
refine le_antisymm (iSup₂_le fun f₀ hf₀ => ?_) (iSup₂_le fun f₀ hf₀ => ?_)
· rw [SimpleFunc.lintegral_map _ hg.measurable]
have : (f₀.comp g hg.measurable : α → ℝ≥0∞) ≤ f ∘ g := fun x => hf₀ (g x)
exact le_iSup_of_le (comp f₀ g hg.measurable) (by exact le_iSup (α := ℝ≥0∞) _ this)
· rw [← f₀.extend_comp_eq hg (const _ 0), ← SimpleFunc.lintegral_map, ←
SimpleFunc.lintegral_eq_lintegral, ← lintegral]
refine lintegral_mono_ae (hg.ae_map_iff.2 <| eventually_of_forall fun x => ?_)
exact (extend_apply _ _ _ _).trans_le (hf₀ _)
#align measurable_embedding.lintegral_map MeasurableEmbedding.lintegral_map
theorem lintegral_map_equiv [MeasurableSpace β] (f : β → ℝ≥0∞) (g : α ≃ᵐ β) :
∫⁻ a, f a ∂map g μ = ∫⁻ a, f (g a) ∂μ :=
g.measurableEmbedding.lintegral_map f
#align measure_theory.lintegral_map_equiv MeasureTheory.lintegral_map_equiv
protected theorem MeasurePreserving.lintegral_map_equiv [MeasurableSpace β] {ν : Measure β}
(f : β → ℝ≥0∞) (g : α ≃ᵐ β) (hg : MeasurePreserving g μ ν) :
∫⁻ a, f a ∂ν = ∫⁻ a, f (g a) ∂μ := by
rw [← MeasureTheory.lintegral_map_equiv f g, hg.map_eq]
theorem MeasurePreserving.lintegral_comp {mb : MeasurableSpace β} {ν : Measure β} {g : α → β}
(hg : MeasurePreserving g μ ν) {f : β → ℝ≥0∞} (hf : Measurable f) :
∫⁻ a, f (g a) ∂μ = ∫⁻ b, f b ∂ν := by rw [← hg.map_eq, lintegral_map hf hg.measurable]
#align measure_theory.measure_preserving.lintegral_comp MeasureTheory.MeasurePreserving.lintegral_comp
theorem MeasurePreserving.lintegral_comp_emb {mb : MeasurableSpace β} {ν : Measure β} {g : α → β}
(hg : MeasurePreserving g μ ν) (hge : MeasurableEmbedding g) (f : β → ℝ≥0∞) :
∫⁻ a, f (g a) ∂μ = ∫⁻ b, f b ∂ν := by rw [← hg.map_eq, hge.lintegral_map]
#align measure_theory.measure_preserving.lintegral_comp_emb MeasureTheory.MeasurePreserving.lintegral_comp_emb
theorem MeasurePreserving.set_lintegral_comp_preimage {mb : MeasurableSpace β} {ν : Measure β}
{g : α → β} (hg : MeasurePreserving g μ ν) {s : Set β} (hs : MeasurableSet s) {f : β → ℝ≥0∞}
(hf : Measurable f) : ∫⁻ a in g ⁻¹' s, f (g a) ∂μ = ∫⁻ b in s, f b ∂ν := by
rw [← hg.map_eq, set_lintegral_map hs hf hg.measurable]
#align measure_theory.measure_preserving.set_lintegral_comp_preimage MeasureTheory.MeasurePreserving.set_lintegral_comp_preimage
theorem MeasurePreserving.set_lintegral_comp_preimage_emb {mb : MeasurableSpace β} {ν : Measure β}
{g : α → β} (hg : MeasurePreserving g μ ν) (hge : MeasurableEmbedding g) (f : β → ℝ≥0∞)
(s : Set β) : ∫⁻ a in g ⁻¹' s, f (g a) ∂μ = ∫⁻ b in s, f b ∂ν := by
rw [← hg.map_eq, hge.restrict_map, hge.lintegral_map]
#align measure_theory.measure_preserving.set_lintegral_comp_preimage_emb MeasureTheory.MeasurePreserving.set_lintegral_comp_preimage_emb
theorem MeasurePreserving.set_lintegral_comp_emb {mb : MeasurableSpace β} {ν : Measure β}
{g : α → β} (hg : MeasurePreserving g μ ν) (hge : MeasurableEmbedding g) (f : β → ℝ≥0∞)
(s : Set α) : ∫⁻ a in s, f (g a) ∂μ = ∫⁻ b in g '' s, f b ∂ν := by
rw [← hg.set_lintegral_comp_preimage_emb hge, preimage_image_eq _ hge.injective]
#align measure_theory.measure_preserving.set_lintegral_comp_emb MeasureTheory.MeasurePreserving.set_lintegral_comp_emb
theorem lintegral_subtype_comap {s : Set α} (hs : MeasurableSet s) (f : α → ℝ≥0∞) :
∫⁻ x : s, f x ∂(μ.comap (↑)) = ∫⁻ x in s, f x ∂μ := by
rw [← (MeasurableEmbedding.subtype_coe hs).lintegral_map, map_comap_subtype_coe hs]
theorem set_lintegral_subtype {s : Set α} (hs : MeasurableSet s) (t : Set s) (f : α → ℝ≥0∞) :
∫⁻ x in t, f x ∂(μ.comap (↑)) = ∫⁻ x in (↑) '' t, f x ∂μ := by
rw [(MeasurableEmbedding.subtype_coe hs).restrict_comap, lintegral_subtype_comap hs,
restrict_restrict hs, inter_eq_right.2 (Subtype.coe_image_subset _ _)]
section Countable
theorem lintegral_countable' [Countable α] [MeasurableSingletonClass α] (f : α → ℝ≥0∞) :
∫⁻ a, f a ∂μ = ∑' a, f a * μ {a} := by
conv_lhs => rw [← sum_smul_dirac μ, lintegral_sum_measure]
congr 1 with a : 1
rw [lintegral_smul_measure, lintegral_dirac, mul_comm]
#align measure_theory.lintegral_countable' MeasureTheory.lintegral_countable'
theorem lintegral_singleton' {f : α → ℝ≥0∞} (hf : Measurable f) (a : α) :
∫⁻ x in {a}, f x ∂μ = f a * μ {a} := by
simp only [restrict_singleton, lintegral_smul_measure, lintegral_dirac' _ hf, mul_comm]
#align measure_theory.lintegral_singleton' MeasureTheory.lintegral_singleton'
theorem lintegral_singleton [MeasurableSingletonClass α] (f : α → ℝ≥0∞) (a : α) :
∫⁻ x in {a}, f x ∂μ = f a * μ {a} := by
simp only [restrict_singleton, lintegral_smul_measure, lintegral_dirac, mul_comm]
#align measure_theory.lintegral_singleton MeasureTheory.lintegral_singleton
theorem lintegral_countable [MeasurableSingletonClass α] (f : α → ℝ≥0∞) {s : Set α}
(hs : s.Countable) : ∫⁻ a in s, f a ∂μ = ∑' a : s, f a * μ {(a : α)} :=
calc
∫⁻ a in s, f a ∂μ = ∫⁻ a in ⋃ x ∈ s, {x}, f a ∂μ := by rw [biUnion_of_singleton]
_ = ∑' a : s, ∫⁻ x in {(a : α)}, f x ∂μ :=
(lintegral_biUnion hs (fun _ _ => measurableSet_singleton _) (pairwiseDisjoint_fiber id s) _)
_ = ∑' a : s, f a * μ {(a : α)} := by simp only [lintegral_singleton]
#align measure_theory.lintegral_countable MeasureTheory.lintegral_countable
theorem lintegral_insert [MeasurableSingletonClass α] {a : α} {s : Set α} (h : a ∉ s)
(f : α → ℝ≥0∞) : ∫⁻ x in insert a s, f x ∂μ = f a * μ {a} + ∫⁻ x in s, f x ∂μ := by
rw [← union_singleton, lintegral_union (measurableSet_singleton a), lintegral_singleton,
add_comm]
rwa [disjoint_singleton_right]
#align measure_theory.lintegral_insert MeasureTheory.lintegral_insert
theorem lintegral_finset [MeasurableSingletonClass α] (s : Finset α) (f : α → ℝ≥0∞) :
∫⁻ x in s, f x ∂μ = ∑ x ∈ s, f x * μ {x} := by
simp only [lintegral_countable _ s.countable_toSet, ← Finset.tsum_subtype']
#align measure_theory.lintegral_finset MeasureTheory.lintegral_finset
| Mathlib/MeasureTheory/Integral/Lebesgue.lean | 1,616 | 1,618 | theorem lintegral_fintype [MeasurableSingletonClass α] [Fintype α] (f : α → ℝ≥0∞) :
∫⁻ x, f x ∂μ = ∑ x, f x * μ {x} := by |
rw [← lintegral_finset, Finset.coe_univ, Measure.restrict_univ]
|
import Mathlib.MeasureTheory.Measure.Lebesgue.Complex
import Mathlib.MeasureTheory.Integral.DivergenceTheorem
import Mathlib.MeasureTheory.Integral.CircleIntegral
import Mathlib.Analysis.Calculus.Dslope
import Mathlib.Analysis.Analytic.Basic
import Mathlib.Analysis.Complex.ReImTopology
import Mathlib.Analysis.Calculus.DiffContOnCl
import Mathlib.Analysis.Calculus.FDeriv.Analytic
import Mathlib.Data.Real.Cardinality
#align_import analysis.complex.cauchy_integral from "leanprover-community/mathlib"@"fd5edc43dc4f10b85abfe544b88f82cf13c5f844"
open TopologicalSpace Set MeasureTheory intervalIntegral Metric Filter Function
open scoped Interval Real NNReal ENNReal Topology
noncomputable section
universe u
variable {E : Type u} [NormedAddCommGroup E] [NormedSpace ℂ E] [CompleteSpace E]
namespace Complex
theorem integral_boundary_rect_of_hasFDerivAt_real_off_countable (f : ℂ → E) (f' : ℂ → ℂ →L[ℝ] E)
(z w : ℂ) (s : Set ℂ) (hs : s.Countable)
(Hc : ContinuousOn f ([[z.re, w.re]] ×ℂ [[z.im, w.im]]))
(Hd : ∀ x ∈ Ioo (min z.re w.re) (max z.re w.re) ×ℂ Ioo (min z.im w.im) (max z.im w.im) \ s,
HasFDerivAt f (f' x) x)
(Hi : IntegrableOn (fun z => I • f' z 1 - f' z I) ([[z.re, w.re]] ×ℂ [[z.im, w.im]])) :
(∫ x : ℝ in z.re..w.re, f (x + z.im * I)) - (∫ x : ℝ in z.re..w.re, f (x + w.im * I)) +
I • (∫ y : ℝ in z.im..w.im, f (re w + y * I)) -
I • ∫ y : ℝ in z.im..w.im, f (re z + y * I) =
∫ x : ℝ in z.re..w.re, ∫ y : ℝ in z.im..w.im, I • f' (x + y * I) 1 - f' (x + y * I) I := by
set e : (ℝ × ℝ) ≃L[ℝ] ℂ := equivRealProdCLM.symm
have he : ∀ x y : ℝ, ↑x + ↑y * I = e (x, y) := fun x y => (mk_eq_add_mul_I x y).symm
have he₁ : e (1, 0) = 1 := rfl; have he₂ : e (0, 1) = I := rfl
simp only [he] at *
set F : ℝ × ℝ → E := f ∘ e
set F' : ℝ × ℝ → ℝ × ℝ →L[ℝ] E := fun p => (f' (e p)).comp (e : ℝ × ℝ →L[ℝ] ℂ)
have hF' : ∀ p : ℝ × ℝ, (-(I • F' p)) (1, 0) + F' p (0, 1) = -(I • f' (e p) 1 - f' (e p) I) := by
rintro ⟨x, y⟩
simp only [F', ContinuousLinearMap.neg_apply, ContinuousLinearMap.smul_apply,
ContinuousLinearMap.comp_apply, ContinuousLinearEquiv.coe_coe, he₁, he₂, neg_add_eq_sub,
neg_sub]
set R : Set (ℝ × ℝ) := [[z.re, w.re]] ×ˢ [[w.im, z.im]]
set t : Set (ℝ × ℝ) := e ⁻¹' s
rw [uIcc_comm z.im] at Hc Hi; rw [min_comm z.im, max_comm z.im] at Hd
have hR : e ⁻¹' ([[z.re, w.re]] ×ℂ [[w.im, z.im]]) = R := rfl
have htc : ContinuousOn F R := Hc.comp e.continuousOn hR.ge
have htd :
∀ p ∈ Ioo (min z.re w.re) (max z.re w.re) ×ˢ Ioo (min w.im z.im) (max w.im z.im) \ t,
HasFDerivAt F (F' p) p :=
fun p hp => (Hd (e p) hp).comp p e.hasFDerivAt
simp_rw [← intervalIntegral.integral_smul, intervalIntegral.integral_symm w.im z.im, ←
intervalIntegral.integral_neg, ← hF']
refine (integral2_divergence_prod_of_hasFDerivWithinAt_off_countable (fun p => -(I • F p)) F
(fun p => -(I • F' p)) F' z.re w.im w.re z.im t (hs.preimage e.injective)
(htc.const_smul _).neg htc (fun p hp => ((htd p hp).const_smul I).neg) htd ?_).symm
rw [← (volume_preserving_equiv_real_prod.symm _).integrableOn_comp_preimage
(MeasurableEquiv.measurableEmbedding _)] at Hi
simpa only [hF'] using Hi.neg
#align complex.integral_boundary_rect_of_has_fderiv_at_real_off_countable Complex.integral_boundary_rect_of_hasFDerivAt_real_off_countable
theorem integral_boundary_rect_of_continuousOn_of_hasFDerivAt_real (f : ℂ → E) (f' : ℂ → ℂ →L[ℝ] E)
(z w : ℂ) (Hc : ContinuousOn f ([[z.re, w.re]] ×ℂ [[z.im, w.im]]))
(Hd : ∀ x ∈ Ioo (min z.re w.re) (max z.re w.re) ×ℂ Ioo (min z.im w.im) (max z.im w.im),
HasFDerivAt f (f' x) x)
(Hi : IntegrableOn (fun z => I • f' z 1 - f' z I) ([[z.re, w.re]] ×ℂ [[z.im, w.im]])) :
(∫ x : ℝ in z.re..w.re, f (x + z.im * I)) - (∫ x : ℝ in z.re..w.re, f (x + w.im * I)) +
I • (∫ y : ℝ in z.im..w.im, f (re w + y * I)) -
I • (∫ y : ℝ in z.im..w.im, f (re z + y * I)) =
∫ x : ℝ in z.re..w.re, ∫ y : ℝ in z.im..w.im, I • f' (x + y * I) 1 - f' (x + y * I) I :=
integral_boundary_rect_of_hasFDerivAt_real_off_countable f f' z w ∅ countable_empty Hc
(fun x hx => Hd x hx.1) Hi
#align complex.integral_boundary_rect_of_continuous_on_of_has_fderiv_at_real Complex.integral_boundary_rect_of_continuousOn_of_hasFDerivAt_real
theorem integral_boundary_rect_of_differentiableOn_real (f : ℂ → E) (z w : ℂ)
(Hd : DifferentiableOn ℝ f ([[z.re, w.re]] ×ℂ [[z.im, w.im]]))
(Hi : IntegrableOn (fun z => I • fderiv ℝ f z 1 - fderiv ℝ f z I)
([[z.re, w.re]] ×ℂ [[z.im, w.im]])) :
(∫ x : ℝ in z.re..w.re, f (x + z.im * I)) - (∫ x : ℝ in z.re..w.re, f (x + w.im * I)) +
I • (∫ y : ℝ in z.im..w.im, f (re w + y * I)) -
I • (∫ y : ℝ in z.im..w.im, f (re z + y * I)) =
∫ x : ℝ in z.re..w.re, ∫ y : ℝ in z.im..w.im,
I • fderiv ℝ f (x + y * I) 1 - fderiv ℝ f (x + y * I) I :=
integral_boundary_rect_of_hasFDerivAt_real_off_countable f (fderiv ℝ f) z w ∅ countable_empty
Hd.continuousOn
(fun x hx => Hd.hasFDerivAt <| by
simpa only [← mem_interior_iff_mem_nhds, interior_reProdIm, uIcc, interior_Icc] using hx.1)
Hi
#align complex.integral_boundary_rect_of_differentiable_on_real Complex.integral_boundary_rect_of_differentiableOn_real
theorem integral_boundary_rect_eq_zero_of_differentiable_on_off_countable (f : ℂ → E) (z w : ℂ)
(s : Set ℂ) (hs : s.Countable) (Hc : ContinuousOn f ([[z.re, w.re]] ×ℂ [[z.im, w.im]]))
(Hd : ∀ x ∈ Ioo (min z.re w.re) (max z.re w.re) ×ℂ Ioo (min z.im w.im) (max z.im w.im) \ s,
DifferentiableAt ℂ f x) :
(∫ x : ℝ in z.re..w.re, f (x + z.im * I)) - (∫ x : ℝ in z.re..w.re, f (x + w.im * I)) +
I • (∫ y : ℝ in z.im..w.im, f (re w + y * I)) -
I • (∫ y : ℝ in z.im..w.im, f (re z + y * I)) = 0 := by
refine (integral_boundary_rect_of_hasFDerivAt_real_off_countable f
(fun z => (fderiv ℂ f z).restrictScalars ℝ) z w s hs Hc
(fun x hx => (Hd x hx).hasFDerivAt.restrictScalars ℝ) ?_).trans ?_ <;>
simp [← ContinuousLinearMap.map_smul]
#align complex.integral_boundary_rect_eq_zero_of_differentiable_on_off_countable Complex.integral_boundary_rect_eq_zero_of_differentiable_on_off_countable
theorem integral_boundary_rect_eq_zero_of_continuousOn_of_differentiableOn (f : ℂ → E) (z w : ℂ)
(Hc : ContinuousOn f ([[z.re, w.re]] ×ℂ [[z.im, w.im]]))
(Hd : DifferentiableOn ℂ f
(Ioo (min z.re w.re) (max z.re w.re) ×ℂ Ioo (min z.im w.im) (max z.im w.im))) :
(∫ x : ℝ in z.re..w.re, f (x + z.im * I)) - (∫ x : ℝ in z.re..w.re, f (x + w.im * I)) +
I • (∫ y : ℝ in z.im..w.im, f (re w + y * I)) -
I • (∫ y : ℝ in z.im..w.im, f (re z + y * I)) = 0 :=
integral_boundary_rect_eq_zero_of_differentiable_on_off_countable f z w ∅ countable_empty Hc
fun _x hx => Hd.differentiableAt <| (isOpen_Ioo.reProdIm isOpen_Ioo).mem_nhds hx.1
#align complex.integral_boundary_rect_eq_zero_of_continuous_on_of_differentiable_on Complex.integral_boundary_rect_eq_zero_of_continuousOn_of_differentiableOn
theorem integral_boundary_rect_eq_zero_of_differentiableOn (f : ℂ → E) (z w : ℂ)
(H : DifferentiableOn ℂ f ([[z.re, w.re]] ×ℂ [[z.im, w.im]])) :
(∫ x : ℝ in z.re..w.re, f (x + z.im * I)) - (∫ x : ℝ in z.re..w.re, f (x + w.im * I)) +
I • (∫ y : ℝ in z.im..w.im, f (re w + y * I)) -
I • (∫ y : ℝ in z.im..w.im, f (re z + y * I)) = 0 :=
integral_boundary_rect_eq_zero_of_continuousOn_of_differentiableOn f z w H.continuousOn <|
H.mono <|
inter_subset_inter (preimage_mono Ioo_subset_Icc_self) (preimage_mono Ioo_subset_Icc_self)
#align complex.integral_boundary_rect_eq_zero_of_differentiable_on Complex.integral_boundary_rect_eq_zero_of_differentiableOn
theorem circleIntegral_sub_center_inv_smul_eq_of_differentiable_on_annulus_off_countable {c : ℂ}
{r R : ℝ} (h0 : 0 < r) (hle : r ≤ R) {f : ℂ → E} {s : Set ℂ} (hs : s.Countable)
(hc : ContinuousOn f (closedBall c R \ ball c r))
(hd : ∀ z ∈ (ball c R \ closedBall c r) \ s, DifferentiableAt ℂ f z) :
(∮ z in C(c, R), (z - c)⁻¹ • f z) = ∮ z in C(c, r), (z - c)⁻¹ • f z := by
set A := closedBall c R \ ball c r
obtain ⟨a, rfl⟩ : ∃ a, Real.exp a = r := ⟨Real.log r, Real.exp_log h0⟩
obtain ⟨b, rfl⟩ : ∃ b, Real.exp b = R := ⟨Real.log R, Real.exp_log (h0.trans_le hle)⟩
rw [Real.exp_le_exp] at hle
-- Unfold definition of `circleIntegral` and cancel some terms.
suffices
(∫ θ in (0)..2 * π, I • f (circleMap c (Real.exp b) θ)) =
∫ θ in (0)..2 * π, I • f (circleMap c (Real.exp a) θ) by
simpa only [circleIntegral, add_sub_cancel_left, ofReal_exp, ← exp_add, smul_smul, ←
div_eq_mul_inv, mul_div_cancel_left₀ _ (circleMap_ne_center (Real.exp_pos _).ne'),
circleMap_sub_center, deriv_circleMap]
set R := [[a, b]] ×ℂ [[0, 2 * π]]
set g : ℂ → ℂ := (c + exp ·)
have hdg : Differentiable ℂ g := differentiable_exp.const_add _
replace hs : (g ⁻¹' s).Countable := (hs.preimage (add_right_injective c)).preimage_cexp
have h_maps : MapsTo g R A := by rintro z ⟨h, -⟩; simpa [g, A, dist_eq, abs_exp, hle] using h.symm
replace hc : ContinuousOn (f ∘ g) R := hc.comp hdg.continuous.continuousOn h_maps
replace hd : ∀ z ∈ Ioo (min a b) (max a b) ×ℂ Ioo (min 0 (2 * π)) (max 0 (2 * π)) \ g ⁻¹' s,
DifferentiableAt ℂ (f ∘ g) z := by
refine fun z hz => (hd (g z) ⟨?_, hz.2⟩).comp z (hdg _)
simpa [g, dist_eq, abs_exp, hle, and_comm] using hz.1.1
simpa [g, circleMap, exp_periodic _, sub_eq_zero, ← exp_add] using
integral_boundary_rect_eq_zero_of_differentiable_on_off_countable _ ⟨a, 0⟩ ⟨b, 2 * π⟩ _ hs hc hd
#align complex.circle_integral_sub_center_inv_smul_eq_of_differentiable_on_annulus_off_countable Complex.circleIntegral_sub_center_inv_smul_eq_of_differentiable_on_annulus_off_countable
theorem circleIntegral_eq_of_differentiable_on_annulus_off_countable {c : ℂ} {r R : ℝ} (h0 : 0 < r)
(hle : r ≤ R) {f : ℂ → E} {s : Set ℂ} (hs : s.Countable)
(hc : ContinuousOn f (closedBall c R \ ball c r))
(hd : ∀ z ∈ (ball c R \ closedBall c r) \ s, DifferentiableAt ℂ f z) :
(∮ z in C(c, R), f z) = ∮ z in C(c, r), f z :=
calc
(∮ z in C(c, R), f z) = ∮ z in C(c, R), (z - c)⁻¹ • (z - c) • f z :=
(circleIntegral.integral_sub_inv_smul_sub_smul _ _ _ _).symm
_ = ∮ z in C(c, r), (z - c)⁻¹ • (z - c) • f z :=
(circleIntegral_sub_center_inv_smul_eq_of_differentiable_on_annulus_off_countable h0 hle hs
((continuousOn_id.sub continuousOn_const).smul hc) fun z hz =>
(differentiableAt_id.sub_const _).smul (hd z hz))
_ = ∮ z in C(c, r), f z := circleIntegral.integral_sub_inv_smul_sub_smul _ _ _ _
#align complex.circle_integral_eq_of_differentiable_on_annulus_off_countable Complex.circleIntegral_eq_of_differentiable_on_annulus_off_countable
theorem circleIntegral_sub_center_inv_smul_of_differentiable_on_off_countable_of_tendsto {c : ℂ}
{R : ℝ} (h0 : 0 < R) {f : ℂ → E} {y : E} {s : Set ℂ} (hs : s.Countable)
(hc : ContinuousOn f (closedBall c R \ {c}))
(hd : ∀ z ∈ (ball c R \ {c}) \ s, DifferentiableAt ℂ f z) (hy : Tendsto f (𝓝[{c}ᶜ] c) (𝓝 y)) :
(∮ z in C(c, R), (z - c)⁻¹ • f z) = (2 * π * I : ℂ) • y := by
rw [← sub_eq_zero, ← norm_le_zero_iff]
refine le_of_forall_le_of_dense fun ε ε0 => ?_
obtain ⟨δ, δ0, hδ⟩ : ∃ δ > (0 : ℝ), ∀ z ∈ closedBall c δ \ {c}, dist (f z) y < ε / (2 * π) :=
((nhdsWithin_hasBasis nhds_basis_closedBall _).tendsto_iff nhds_basis_ball).1 hy _
(div_pos ε0 Real.two_pi_pos)
obtain ⟨r, hr0, hrδ, hrR⟩ : ∃ r, 0 < r ∧ r ≤ δ ∧ r ≤ R :=
⟨min δ R, lt_min δ0 h0, min_le_left _ _, min_le_right _ _⟩
have hsub : closedBall c R \ ball c r ⊆ closedBall c R \ {c} :=
diff_subset_diff_right (singleton_subset_iff.2 <| mem_ball_self hr0)
have hsub' : ball c R \ closedBall c r ⊆ ball c R \ {c} :=
diff_subset_diff_right (singleton_subset_iff.2 <| mem_closedBall_self hr0.le)
have hzne : ∀ z ∈ sphere c r, z ≠ c := fun z hz =>
ne_of_mem_of_not_mem hz fun h => hr0.ne' <| dist_self c ▸ Eq.symm h
calc
‖(∮ z in C(c, R), (z - c)⁻¹ • f z) - (2 * ↑π * I) • y‖ =
‖(∮ z in C(c, r), (z - c)⁻¹ • f z) - ∮ z in C(c, r), (z - c)⁻¹ • y‖ := by
congr 2
· exact circleIntegral_sub_center_inv_smul_eq_of_differentiable_on_annulus_off_countable hr0
hrR hs (hc.mono hsub) fun z hz => hd z ⟨hsub' hz.1, hz.2⟩
· simp [hr0.ne']
_ = ‖∮ z in C(c, r), (z - c)⁻¹ • (f z - y)‖ := by
simp only [smul_sub]
have hc' : ContinuousOn (fun z => (z - c)⁻¹) (sphere c r) :=
(continuousOn_id.sub continuousOn_const).inv₀ fun z hz => sub_ne_zero.2 <| hzne _ hz
rw [circleIntegral.integral_sub] <;> refine (hc'.smul ?_).circleIntegrable hr0.le
· exact hc.mono <| subset_inter
(sphere_subset_closedBall.trans <| closedBall_subset_closedBall hrR) hzne
· exact continuousOn_const
_ ≤ 2 * π * r * (r⁻¹ * (ε / (2 * π))) := by
refine circleIntegral.norm_integral_le_of_norm_le_const hr0.le fun z hz => ?_
specialize hzne z hz
rw [mem_sphere, dist_eq_norm] at hz
rw [norm_smul, norm_inv, hz, ← dist_eq_norm]
refine mul_le_mul_of_nonneg_left (hδ _ ⟨?_, hzne⟩).le (inv_nonneg.2 hr0.le)
rwa [mem_closedBall_iff_norm, hz]
_ = ε := by field_simp [hr0.ne', Real.two_pi_pos.ne']; ac_rfl
#align complex.circle_integral_sub_center_inv_smul_of_differentiable_on_off_countable_of_tendsto Complex.circleIntegral_sub_center_inv_smul_of_differentiable_on_off_countable_of_tendsto
theorem circleIntegral_sub_center_inv_smul_of_differentiable_on_off_countable {R : ℝ} (h0 : 0 < R)
{f : ℂ → E} {c : ℂ} {s : Set ℂ} (hs : s.Countable) (hc : ContinuousOn f (closedBall c R))
(hd : ∀ z ∈ ball c R \ s, DifferentiableAt ℂ f z) :
(∮ z in C(c, R), (z - c)⁻¹ • f z) = (2 * π * I : ℂ) • f c :=
circleIntegral_sub_center_inv_smul_of_differentiable_on_off_countable_of_tendsto h0 hs
(hc.mono diff_subset) (fun z hz => hd z ⟨hz.1.1, hz.2⟩)
(hc.continuousAt <| closedBall_mem_nhds _ h0).continuousWithinAt
#align complex.circle_integral_sub_center_inv_smul_of_differentiable_on_off_countable Complex.circleIntegral_sub_center_inv_smul_of_differentiable_on_off_countable
theorem circleIntegral_eq_zero_of_differentiable_on_off_countable {R : ℝ} (h0 : 0 ≤ R) {f : ℂ → E}
{c : ℂ} {s : Set ℂ} (hs : s.Countable) (hc : ContinuousOn f (closedBall c R))
(hd : ∀ z ∈ ball c R \ s, DifferentiableAt ℂ f z) : (∮ z in C(c, R), f z) = 0 := by
rcases h0.eq_or_lt with (rfl | h0); · apply circleIntegral.integral_radius_zero
calc
(∮ z in C(c, R), f z) = ∮ z in C(c, R), (z - c)⁻¹ • (z - c) • f z :=
(circleIntegral.integral_sub_inv_smul_sub_smul _ _ _ _).symm
_ = (2 * ↑π * I : ℂ) • (c - c) • f c :=
(circleIntegral_sub_center_inv_smul_of_differentiable_on_off_countable h0 hs
((continuousOn_id.sub continuousOn_const).smul hc) fun z hz =>
(differentiableAt_id.sub_const _).smul (hd z hz))
_ = 0 := by rw [sub_self, zero_smul, smul_zero]
#align complex.circle_integral_eq_zero_of_differentiable_on_off_countable Complex.circleIntegral_eq_zero_of_differentiable_on_off_countable
theorem circleIntegral_sub_inv_smul_of_differentiable_on_off_countable_aux {R : ℝ} {c w : ℂ}
{f : ℂ → E} {s : Set ℂ} (hs : s.Countable) (hw : w ∈ ball c R \ s)
(hc : ContinuousOn f (closedBall c R)) (hd : ∀ x ∈ ball c R \ s, DifferentiableAt ℂ f x) :
(∮ z in C(c, R), (z - w)⁻¹ • f z) = (2 * π * I : ℂ) • f w := by
have hR : 0 < R := dist_nonneg.trans_lt hw.1
set F : ℂ → E := dslope f w
have hws : (insert w s).Countable := hs.insert w
have hcF : ContinuousOn F (closedBall c R) :=
(continuousOn_dslope <| closedBall_mem_nhds_of_mem hw.1).2 ⟨hc, hd _ hw⟩
have hdF : ∀ z ∈ ball (c : ℂ) R \ insert w s, DifferentiableAt ℂ F z := fun z hz =>
(differentiableAt_dslope_of_ne (ne_of_mem_of_not_mem (mem_insert _ _) hz.2).symm).2
(hd _ (diff_subset_diff_right (subset_insert _ _) hz))
have HI := circleIntegral_eq_zero_of_differentiable_on_off_countable hR.le hws hcF hdF
have hne : ∀ z ∈ sphere c R, z ≠ w := fun z hz => ne_of_mem_of_not_mem hz (ne_of_lt hw.1)
have hFeq : EqOn F (fun z => (z - w)⁻¹ • f z - (z - w)⁻¹ • f w) (sphere c R) := fun z hz ↦
calc
F z = (z - w)⁻¹ • (f z - f w) := update_noteq (hne z hz) _ _
_ = (z - w)⁻¹ • f z - (z - w)⁻¹ • f w := smul_sub _ _ _
have hc' : ContinuousOn (fun z => (z - w)⁻¹) (sphere c R) :=
(continuousOn_id.sub continuousOn_const).inv₀ fun z hz => sub_ne_zero.2 <| hne z hz
rw [← circleIntegral.integral_sub_inv_of_mem_ball hw.1, ← circleIntegral.integral_smul_const, ←
sub_eq_zero, ← circleIntegral.integral_sub, ← circleIntegral.integral_congr hR.le hFeq, HI]
exacts [(hc'.smul (hc.mono sphere_subset_closedBall)).circleIntegrable hR.le,
(hc'.smul continuousOn_const).circleIntegrable hR.le]
#align complex.circle_integral_sub_inv_smul_of_differentiable_on_off_countable_aux Complex.circleIntegral_sub_inv_smul_of_differentiable_on_off_countable_aux
| Mathlib/Analysis/Complex/CauchyIntegral.lean | 457 | 488 | theorem two_pi_I_inv_smul_circleIntegral_sub_inv_smul_of_differentiable_on_off_countable {R : ℝ}
{c w : ℂ} {f : ℂ → E} {s : Set ℂ} (hs : s.Countable) (hw : w ∈ ball c R)
(hc : ContinuousOn f (closedBall c R)) (hd : ∀ x ∈ ball c R \ s, DifferentiableAt ℂ f x) :
((2 * π * I : ℂ)⁻¹ • ∮ z in C(c, R), (z - w)⁻¹ • f z) = f w := by |
have hR : 0 < R := dist_nonneg.trans_lt hw
suffices w ∈ closure (ball c R \ s) by
lift R to ℝ≥0 using hR.le
have A : ContinuousAt (fun w => (2 * π * I : ℂ)⁻¹ • ∮ z in C(c, R), (z - w)⁻¹ • f z) w := by
have := hasFPowerSeriesOn_cauchy_integral
((hc.mono sphere_subset_closedBall).circleIntegrable R.coe_nonneg) hR
refine this.continuousOn.continuousAt (EMetric.isOpen_ball.mem_nhds ?_)
rwa [Metric.emetric_ball_nnreal]
have B : ContinuousAt f w := hc.continuousAt (closedBall_mem_nhds_of_mem hw)
refine tendsto_nhds_unique_of_frequently_eq A B ((mem_closure_iff_frequently.1 this).mono ?_)
intro z hz
rw [circleIntegral_sub_inv_smul_of_differentiable_on_off_countable_aux hs hz hc hd,
inv_smul_smul₀]
simp [Real.pi_ne_zero, I_ne_zero]
refine mem_closure_iff_nhds.2 fun t ht => ?_
-- TODO: generalize to any vector space over `ℝ`
set g : ℝ → ℂ := fun x => w + ofReal x
have : Tendsto g (𝓝 0) (𝓝 w) :=
(continuous_const.add continuous_ofReal).tendsto' 0 w (add_zero _)
rcases mem_nhds_iff_exists_Ioo_subset.1 (this <| inter_mem ht <| isOpen_ball.mem_nhds hw) with
⟨l, u, hlu₀, hlu_sub⟩
obtain ⟨x, hx⟩ : (Ioo l u \ g ⁻¹' s).Nonempty := by
refine nonempty_diff.2 fun hsub => ?_
have : (Ioo l u).Countable :=
(hs.preimage ((add_right_injective w).comp ofReal_injective)).mono hsub
rw [← Cardinal.le_aleph0_iff_set_countable, Cardinal.mk_Ioo_real (hlu₀.1.trans hlu₀.2)] at this
exact this.not_lt Cardinal.aleph0_lt_continuum
exact ⟨g x, (hlu_sub hx.1).1, (hlu_sub hx.1).2, hx.2⟩
|
import Mathlib.Data.Finset.Card
#align_import data.finset.option from "leanprover-community/mathlib"@"c227d107bbada5d0d9d20287e3282c0a7f1651a0"
variable {α β : Type*}
open Function
namespace Option
def toFinset (o : Option α) : Finset α :=
o.elim ∅ singleton
#align option.to_finset Option.toFinset
@[simp]
theorem toFinset_none : none.toFinset = (∅ : Finset α) :=
rfl
#align option.to_finset_none Option.toFinset_none
@[simp]
theorem toFinset_some {a : α} : (some a).toFinset = {a} :=
rfl
#align option.to_finset_some Option.toFinset_some
@[simp]
| Mathlib/Data/Finset/Option.lean | 51 | 52 | theorem mem_toFinset {a : α} {o : Option α} : a ∈ o.toFinset ↔ a ∈ o := by |
cases o <;> simp [eq_comm]
|
import Mathlib.Combinatorics.SimpleGraph.Subgraph
import Mathlib.Data.List.Rotate
#align_import combinatorics.simple_graph.connectivity from "leanprover-community/mathlib"@"b99e2d58a5e6861833fa8de11e51a81144258db4"
open Function
universe u v w
namespace SimpleGraph
variable {V : Type u} {V' : Type v} {V'' : Type w}
variable (G : SimpleGraph V) (G' : SimpleGraph V') (G'' : SimpleGraph V'')
inductive Walk : V → V → Type u
| nil {u : V} : Walk u u
| cons {u v w : V} (h : G.Adj u v) (p : Walk v w) : Walk u w
deriving DecidableEq
#align simple_graph.walk SimpleGraph.Walk
attribute [refl] Walk.nil
@[simps]
instance Walk.instInhabited (v : V) : Inhabited (G.Walk v v) := ⟨Walk.nil⟩
#align simple_graph.walk.inhabited SimpleGraph.Walk.instInhabited
@[match_pattern, reducible]
def Adj.toWalk {G : SimpleGraph V} {u v : V} (h : G.Adj u v) : G.Walk u v :=
Walk.cons h Walk.nil
#align simple_graph.adj.to_walk SimpleGraph.Adj.toWalk
namespace Walk
variable {G}
@[match_pattern]
abbrev nil' (u : V) : G.Walk u u := Walk.nil
#align simple_graph.walk.nil' SimpleGraph.Walk.nil'
@[match_pattern]
abbrev cons' (u v w : V) (h : G.Adj u v) (p : G.Walk v w) : G.Walk u w := Walk.cons h p
#align simple_graph.walk.cons' SimpleGraph.Walk.cons'
protected def copy {u v u' v'} (p : G.Walk u v) (hu : u = u') (hv : v = v') : G.Walk u' v' :=
hu ▸ hv ▸ p
#align simple_graph.walk.copy SimpleGraph.Walk.copy
@[simp]
theorem copy_rfl_rfl {u v} (p : G.Walk u v) : p.copy rfl rfl = p := rfl
#align simple_graph.walk.copy_rfl_rfl SimpleGraph.Walk.copy_rfl_rfl
@[simp]
theorem copy_copy {u v u' v' u'' v''} (p : G.Walk u v)
(hu : u = u') (hv : v = v') (hu' : u' = u'') (hv' : v' = v'') :
(p.copy hu hv).copy hu' hv' = p.copy (hu.trans hu') (hv.trans hv') := by
subst_vars
rfl
#align simple_graph.walk.copy_copy SimpleGraph.Walk.copy_copy
@[simp]
theorem copy_nil {u u'} (hu : u = u') : (Walk.nil : G.Walk u u).copy hu hu = Walk.nil := by
subst_vars
rfl
#align simple_graph.walk.copy_nil SimpleGraph.Walk.copy_nil
theorem copy_cons {u v w u' w'} (h : G.Adj u v) (p : G.Walk v w) (hu : u = u') (hw : w = w') :
(Walk.cons h p).copy hu hw = Walk.cons (hu ▸ h) (p.copy rfl hw) := by
subst_vars
rfl
#align simple_graph.walk.copy_cons SimpleGraph.Walk.copy_cons
@[simp]
theorem cons_copy {u v w v' w'} (h : G.Adj u v) (p : G.Walk v' w') (hv : v' = v) (hw : w' = w) :
Walk.cons h (p.copy hv hw) = (Walk.cons (hv ▸ h) p).copy rfl hw := by
subst_vars
rfl
#align simple_graph.walk.cons_copy SimpleGraph.Walk.cons_copy
theorem exists_eq_cons_of_ne {u v : V} (hne : u ≠ v) :
∀ (p : G.Walk u v), ∃ (w : V) (h : G.Adj u w) (p' : G.Walk w v), p = cons h p'
| nil => (hne rfl).elim
| cons h p' => ⟨_, h, p', rfl⟩
#align simple_graph.walk.exists_eq_cons_of_ne SimpleGraph.Walk.exists_eq_cons_of_ne
def length {u v : V} : G.Walk u v → ℕ
| nil => 0
| cons _ q => q.length.succ
#align simple_graph.walk.length SimpleGraph.Walk.length
@[trans]
def append {u v w : V} : G.Walk u v → G.Walk v w → G.Walk u w
| nil, q => q
| cons h p, q => cons h (p.append q)
#align simple_graph.walk.append SimpleGraph.Walk.append
def concat {u v w : V} (p : G.Walk u v) (h : G.Adj v w) : G.Walk u w := p.append (cons h nil)
#align simple_graph.walk.concat SimpleGraph.Walk.concat
theorem concat_eq_append {u v w : V} (p : G.Walk u v) (h : G.Adj v w) :
p.concat h = p.append (cons h nil) := rfl
#align simple_graph.walk.concat_eq_append SimpleGraph.Walk.concat_eq_append
protected def reverseAux {u v w : V} : G.Walk u v → G.Walk u w → G.Walk v w
| nil, q => q
| cons h p, q => Walk.reverseAux p (cons (G.symm h) q)
#align simple_graph.walk.reverse_aux SimpleGraph.Walk.reverseAux
@[symm]
def reverse {u v : V} (w : G.Walk u v) : G.Walk v u := w.reverseAux nil
#align simple_graph.walk.reverse SimpleGraph.Walk.reverse
def getVert {u v : V} : G.Walk u v → ℕ → V
| nil, _ => u
| cons _ _, 0 => u
| cons _ q, n + 1 => q.getVert n
#align simple_graph.walk.get_vert SimpleGraph.Walk.getVert
@[simp]
theorem getVert_zero {u v} (w : G.Walk u v) : w.getVert 0 = u := by cases w <;> rfl
#align simple_graph.walk.get_vert_zero SimpleGraph.Walk.getVert_zero
theorem getVert_of_length_le {u v} (w : G.Walk u v) {i : ℕ} (hi : w.length ≤ i) :
w.getVert i = v := by
induction w generalizing i with
| nil => rfl
| cons _ _ ih =>
cases i
· cases hi
· exact ih (Nat.succ_le_succ_iff.1 hi)
#align simple_graph.walk.get_vert_of_length_le SimpleGraph.Walk.getVert_of_length_le
@[simp]
theorem getVert_length {u v} (w : G.Walk u v) : w.getVert w.length = v :=
w.getVert_of_length_le rfl.le
#align simple_graph.walk.get_vert_length SimpleGraph.Walk.getVert_length
theorem adj_getVert_succ {u v} (w : G.Walk u v) {i : ℕ} (hi : i < w.length) :
G.Adj (w.getVert i) (w.getVert (i + 1)) := by
induction w generalizing i with
| nil => cases hi
| cons hxy _ ih =>
cases i
· simp [getVert, hxy]
· exact ih (Nat.succ_lt_succ_iff.1 hi)
#align simple_graph.walk.adj_get_vert_succ SimpleGraph.Walk.adj_getVert_succ
@[simp]
theorem cons_append {u v w x : V} (h : G.Adj u v) (p : G.Walk v w) (q : G.Walk w x) :
(cons h p).append q = cons h (p.append q) := rfl
#align simple_graph.walk.cons_append SimpleGraph.Walk.cons_append
@[simp]
theorem cons_nil_append {u v w : V} (h : G.Adj u v) (p : G.Walk v w) :
(cons h nil).append p = cons h p := rfl
#align simple_graph.walk.cons_nil_append SimpleGraph.Walk.cons_nil_append
@[simp]
theorem append_nil {u v : V} (p : G.Walk u v) : p.append nil = p := by
induction p with
| nil => rfl
| cons _ _ ih => rw [cons_append, ih]
#align simple_graph.walk.append_nil SimpleGraph.Walk.append_nil
@[simp]
theorem nil_append {u v : V} (p : G.Walk u v) : nil.append p = p :=
rfl
#align simple_graph.walk.nil_append SimpleGraph.Walk.nil_append
theorem append_assoc {u v w x : V} (p : G.Walk u v) (q : G.Walk v w) (r : G.Walk w x) :
p.append (q.append r) = (p.append q).append r := by
induction p with
| nil => rfl
| cons h p' ih =>
dsimp only [append]
rw [ih]
#align simple_graph.walk.append_assoc SimpleGraph.Walk.append_assoc
@[simp]
theorem append_copy_copy {u v w u' v' w'} (p : G.Walk u v) (q : G.Walk v w)
(hu : u = u') (hv : v = v') (hw : w = w') :
(p.copy hu hv).append (q.copy hv hw) = (p.append q).copy hu hw := by
subst_vars
rfl
#align simple_graph.walk.append_copy_copy SimpleGraph.Walk.append_copy_copy
theorem concat_nil {u v : V} (h : G.Adj u v) : nil.concat h = cons h nil := rfl
#align simple_graph.walk.concat_nil SimpleGraph.Walk.concat_nil
@[simp]
theorem concat_cons {u v w x : V} (h : G.Adj u v) (p : G.Walk v w) (h' : G.Adj w x) :
(cons h p).concat h' = cons h (p.concat h') := rfl
#align simple_graph.walk.concat_cons SimpleGraph.Walk.concat_cons
theorem append_concat {u v w x : V} (p : G.Walk u v) (q : G.Walk v w) (h : G.Adj w x) :
p.append (q.concat h) = (p.append q).concat h := append_assoc _ _ _
#align simple_graph.walk.append_concat SimpleGraph.Walk.append_concat
theorem concat_append {u v w x : V} (p : G.Walk u v) (h : G.Adj v w) (q : G.Walk w x) :
(p.concat h).append q = p.append (cons h q) := by
rw [concat_eq_append, ← append_assoc, cons_nil_append]
#align simple_graph.walk.concat_append SimpleGraph.Walk.concat_append
theorem exists_cons_eq_concat {u v w : V} (h : G.Adj u v) (p : G.Walk v w) :
∃ (x : V) (q : G.Walk u x) (h' : G.Adj x w), cons h p = q.concat h' := by
induction p generalizing u with
| nil => exact ⟨_, nil, h, rfl⟩
| cons h' p ih =>
obtain ⟨y, q, h'', hc⟩ := ih h'
refine ⟨y, cons h q, h'', ?_⟩
rw [concat_cons, hc]
#align simple_graph.walk.exists_cons_eq_concat SimpleGraph.Walk.exists_cons_eq_concat
theorem exists_concat_eq_cons {u v w : V} :
∀ (p : G.Walk u v) (h : G.Adj v w),
∃ (x : V) (h' : G.Adj u x) (q : G.Walk x w), p.concat h = cons h' q
| nil, h => ⟨_, h, nil, rfl⟩
| cons h' p, h => ⟨_, h', Walk.concat p h, concat_cons _ _ _⟩
#align simple_graph.walk.exists_concat_eq_cons SimpleGraph.Walk.exists_concat_eq_cons
@[simp]
theorem reverse_nil {u : V} : (nil : G.Walk u u).reverse = nil := rfl
#align simple_graph.walk.reverse_nil SimpleGraph.Walk.reverse_nil
theorem reverse_singleton {u v : V} (h : G.Adj u v) : (cons h nil).reverse = cons (G.symm h) nil :=
rfl
#align simple_graph.walk.reverse_singleton SimpleGraph.Walk.reverse_singleton
@[simp]
theorem cons_reverseAux {u v w x : V} (p : G.Walk u v) (q : G.Walk w x) (h : G.Adj w u) :
(cons h p).reverseAux q = p.reverseAux (cons (G.symm h) q) := rfl
#align simple_graph.walk.cons_reverse_aux SimpleGraph.Walk.cons_reverseAux
@[simp]
protected theorem append_reverseAux {u v w x : V}
(p : G.Walk u v) (q : G.Walk v w) (r : G.Walk u x) :
(p.append q).reverseAux r = q.reverseAux (p.reverseAux r) := by
induction p with
| nil => rfl
| cons h _ ih => exact ih q (cons (G.symm h) r)
#align simple_graph.walk.append_reverse_aux SimpleGraph.Walk.append_reverseAux
@[simp]
protected theorem reverseAux_append {u v w x : V}
(p : G.Walk u v) (q : G.Walk u w) (r : G.Walk w x) :
(p.reverseAux q).append r = p.reverseAux (q.append r) := by
induction p with
| nil => rfl
| cons h _ ih => simp [ih (cons (G.symm h) q)]
#align simple_graph.walk.reverse_aux_append SimpleGraph.Walk.reverseAux_append
protected theorem reverseAux_eq_reverse_append {u v w : V} (p : G.Walk u v) (q : G.Walk u w) :
p.reverseAux q = p.reverse.append q := by simp [reverse]
#align simple_graph.walk.reverse_aux_eq_reverse_append SimpleGraph.Walk.reverseAux_eq_reverse_append
@[simp]
theorem reverse_cons {u v w : V} (h : G.Adj u v) (p : G.Walk v w) :
(cons h p).reverse = p.reverse.append (cons (G.symm h) nil) := by simp [reverse]
#align simple_graph.walk.reverse_cons SimpleGraph.Walk.reverse_cons
@[simp]
theorem reverse_copy {u v u' v'} (p : G.Walk u v) (hu : u = u') (hv : v = v') :
(p.copy hu hv).reverse = p.reverse.copy hv hu := by
subst_vars
rfl
#align simple_graph.walk.reverse_copy SimpleGraph.Walk.reverse_copy
@[simp]
theorem reverse_append {u v w : V} (p : G.Walk u v) (q : G.Walk v w) :
(p.append q).reverse = q.reverse.append p.reverse := by simp [reverse]
#align simple_graph.walk.reverse_append SimpleGraph.Walk.reverse_append
@[simp]
theorem reverse_concat {u v w : V} (p : G.Walk u v) (h : G.Adj v w) :
(p.concat h).reverse = cons (G.symm h) p.reverse := by simp [concat_eq_append]
#align simple_graph.walk.reverse_concat SimpleGraph.Walk.reverse_concat
@[simp]
theorem reverse_reverse {u v : V} (p : G.Walk u v) : p.reverse.reverse = p := by
induction p with
| nil => rfl
| cons _ _ ih => simp [ih]
#align simple_graph.walk.reverse_reverse SimpleGraph.Walk.reverse_reverse
@[simp]
theorem length_nil {u : V} : (nil : G.Walk u u).length = 0 := rfl
#align simple_graph.walk.length_nil SimpleGraph.Walk.length_nil
@[simp]
theorem length_cons {u v w : V} (h : G.Adj u v) (p : G.Walk v w) :
(cons h p).length = p.length + 1 := rfl
#align simple_graph.walk.length_cons SimpleGraph.Walk.length_cons
@[simp]
theorem length_copy {u v u' v'} (p : G.Walk u v) (hu : u = u') (hv : v = v') :
(p.copy hu hv).length = p.length := by
subst_vars
rfl
#align simple_graph.walk.length_copy SimpleGraph.Walk.length_copy
@[simp]
theorem length_append {u v w : V} (p : G.Walk u v) (q : G.Walk v w) :
(p.append q).length = p.length + q.length := by
induction p with
| nil => simp
| cons _ _ ih => simp [ih, add_comm, add_left_comm, add_assoc]
#align simple_graph.walk.length_append SimpleGraph.Walk.length_append
@[simp]
theorem length_concat {u v w : V} (p : G.Walk u v) (h : G.Adj v w) :
(p.concat h).length = p.length + 1 := length_append _ _
#align simple_graph.walk.length_concat SimpleGraph.Walk.length_concat
@[simp]
protected theorem length_reverseAux {u v w : V} (p : G.Walk u v) (q : G.Walk u w) :
(p.reverseAux q).length = p.length + q.length := by
induction p with
| nil => simp!
| cons _ _ ih => simp [ih, Nat.succ_add, Nat.add_assoc]
#align simple_graph.walk.length_reverse_aux SimpleGraph.Walk.length_reverseAux
@[simp]
theorem length_reverse {u v : V} (p : G.Walk u v) : p.reverse.length = p.length := by simp [reverse]
#align simple_graph.walk.length_reverse SimpleGraph.Walk.length_reverse
theorem eq_of_length_eq_zero {u v : V} : ∀ {p : G.Walk u v}, p.length = 0 → u = v
| nil, _ => rfl
#align simple_graph.walk.eq_of_length_eq_zero SimpleGraph.Walk.eq_of_length_eq_zero
theorem adj_of_length_eq_one {u v : V} : ∀ {p : G.Walk u v}, p.length = 1 → G.Adj u v
| cons h nil, _ => h
@[simp]
theorem exists_length_eq_zero_iff {u v : V} : (∃ p : G.Walk u v, p.length = 0) ↔ u = v := by
constructor
· rintro ⟨p, hp⟩
exact eq_of_length_eq_zero hp
· rintro rfl
exact ⟨nil, rfl⟩
#align simple_graph.walk.exists_length_eq_zero_iff SimpleGraph.Walk.exists_length_eq_zero_iff
@[simp]
theorem length_eq_zero_iff {u : V} {p : G.Walk u u} : p.length = 0 ↔ p = nil := by cases p <;> simp
#align simple_graph.walk.length_eq_zero_iff SimpleGraph.Walk.length_eq_zero_iff
theorem getVert_append {u v w : V} (p : G.Walk u v) (q : G.Walk v w) (i : ℕ) :
(p.append q).getVert i = if i < p.length then p.getVert i else q.getVert (i - p.length) := by
induction p generalizing i with
| nil => simp
| cons h p ih => cases i <;> simp [getVert, ih, Nat.succ_lt_succ_iff]
theorem getVert_reverse {u v : V} (p : G.Walk u v) (i : ℕ) :
p.reverse.getVert i = p.getVert (p.length - i) := by
induction p with
| nil => rfl
| cons h p ih =>
simp only [reverse_cons, getVert_append, length_reverse, ih, length_cons]
split_ifs
next hi =>
rw [Nat.succ_sub hi.le]
simp [getVert]
next hi =>
obtain rfl | hi' := Nat.eq_or_lt_of_not_lt hi
· simp [getVert]
· rw [Nat.eq_add_of_sub_eq (Nat.sub_pos_of_lt hi') rfl, Nat.sub_eq_zero_of_le hi']
simp [getVert]
theorem concat_ne_nil {u v : V} (p : G.Walk u v) (h : G.Adj v u) : p.concat h ≠ nil := by
cases p <;> simp [concat]
#align simple_graph.walk.concat_ne_nil SimpleGraph.Walk.concat_ne_nil
theorem concat_inj {u v v' w : V} {p : G.Walk u v} {h : G.Adj v w} {p' : G.Walk u v'}
{h' : G.Adj v' w} (he : p.concat h = p'.concat h') : ∃ hv : v = v', p.copy rfl hv = p' := by
induction p with
| nil =>
cases p'
· exact ⟨rfl, rfl⟩
· exfalso
simp only [concat_nil, concat_cons, cons.injEq] at he
obtain ⟨rfl, he⟩ := he
simp only [heq_iff_eq] at he
exact concat_ne_nil _ _ he.symm
| cons _ _ ih =>
rw [concat_cons] at he
cases p'
· exfalso
simp only [concat_nil, cons.injEq] at he
obtain ⟨rfl, he⟩ := he
rw [heq_iff_eq] at he
exact concat_ne_nil _ _ he
· rw [concat_cons, cons.injEq] at he
obtain ⟨rfl, he⟩ := he
rw [heq_iff_eq] at he
obtain ⟨rfl, rfl⟩ := ih he
exact ⟨rfl, rfl⟩
#align simple_graph.walk.concat_inj SimpleGraph.Walk.concat_inj
def support {u v : V} : G.Walk u v → List V
| nil => [u]
| cons _ p => u :: p.support
#align simple_graph.walk.support SimpleGraph.Walk.support
def darts {u v : V} : G.Walk u v → List G.Dart
| nil => []
| cons h p => ⟨(u, _), h⟩ :: p.darts
#align simple_graph.walk.darts SimpleGraph.Walk.darts
def edges {u v : V} (p : G.Walk u v) : List (Sym2 V) := p.darts.map Dart.edge
#align simple_graph.walk.edges SimpleGraph.Walk.edges
@[simp]
theorem support_nil {u : V} : (nil : G.Walk u u).support = [u] := rfl
#align simple_graph.walk.support_nil SimpleGraph.Walk.support_nil
@[simp]
theorem support_cons {u v w : V} (h : G.Adj u v) (p : G.Walk v w) :
(cons h p).support = u :: p.support := rfl
#align simple_graph.walk.support_cons SimpleGraph.Walk.support_cons
@[simp]
theorem support_concat {u v w : V} (p : G.Walk u v) (h : G.Adj v w) :
(p.concat h).support = p.support.concat w := by
induction p <;> simp [*, concat_nil]
#align simple_graph.walk.support_concat SimpleGraph.Walk.support_concat
@[simp]
theorem support_copy {u v u' v'} (p : G.Walk u v) (hu : u = u') (hv : v = v') :
(p.copy hu hv).support = p.support := by
subst_vars
rfl
#align simple_graph.walk.support_copy SimpleGraph.Walk.support_copy
theorem support_append {u v w : V} (p : G.Walk u v) (p' : G.Walk v w) :
(p.append p').support = p.support ++ p'.support.tail := by
induction p <;> cases p' <;> simp [*]
#align simple_graph.walk.support_append SimpleGraph.Walk.support_append
@[simp]
theorem support_reverse {u v : V} (p : G.Walk u v) : p.reverse.support = p.support.reverse := by
induction p <;> simp [support_append, *]
#align simple_graph.walk.support_reverse SimpleGraph.Walk.support_reverse
@[simp]
theorem support_ne_nil {u v : V} (p : G.Walk u v) : p.support ≠ [] := by cases p <;> simp
#align simple_graph.walk.support_ne_nil SimpleGraph.Walk.support_ne_nil
theorem tail_support_append {u v w : V} (p : G.Walk u v) (p' : G.Walk v w) :
(p.append p').support.tail = p.support.tail ++ p'.support.tail := by
rw [support_append, List.tail_append_of_ne_nil _ _ (support_ne_nil _)]
#align simple_graph.walk.tail_support_append SimpleGraph.Walk.tail_support_append
theorem support_eq_cons {u v : V} (p : G.Walk u v) : p.support = u :: p.support.tail := by
cases p <;> simp
#align simple_graph.walk.support_eq_cons SimpleGraph.Walk.support_eq_cons
@[simp]
theorem start_mem_support {u v : V} (p : G.Walk u v) : u ∈ p.support := by cases p <;> simp
#align simple_graph.walk.start_mem_support SimpleGraph.Walk.start_mem_support
@[simp]
theorem end_mem_support {u v : V} (p : G.Walk u v) : v ∈ p.support := by induction p <;> simp [*]
#align simple_graph.walk.end_mem_support SimpleGraph.Walk.end_mem_support
@[simp]
theorem support_nonempty {u v : V} (p : G.Walk u v) : { w | w ∈ p.support }.Nonempty :=
⟨u, by simp⟩
#align simple_graph.walk.support_nonempty SimpleGraph.Walk.support_nonempty
theorem mem_support_iff {u v w : V} (p : G.Walk u v) :
w ∈ p.support ↔ w = u ∨ w ∈ p.support.tail := by cases p <;> simp
#align simple_graph.walk.mem_support_iff SimpleGraph.Walk.mem_support_iff
theorem mem_support_nil_iff {u v : V} : u ∈ (nil : G.Walk v v).support ↔ u = v := by simp
#align simple_graph.walk.mem_support_nil_iff SimpleGraph.Walk.mem_support_nil_iff
@[simp]
theorem mem_tail_support_append_iff {t u v w : V} (p : G.Walk u v) (p' : G.Walk v w) :
t ∈ (p.append p').support.tail ↔ t ∈ p.support.tail ∨ t ∈ p'.support.tail := by
rw [tail_support_append, List.mem_append]
#align simple_graph.walk.mem_tail_support_append_iff SimpleGraph.Walk.mem_tail_support_append_iff
@[simp]
theorem end_mem_tail_support_of_ne {u v : V} (h : u ≠ v) (p : G.Walk u v) : v ∈ p.support.tail := by
obtain ⟨_, _, _, rfl⟩ := exists_eq_cons_of_ne h p
simp
#align simple_graph.walk.end_mem_tail_support_of_ne SimpleGraph.Walk.end_mem_tail_support_of_ne
@[simp, nolint unusedHavesSuffices]
theorem mem_support_append_iff {t u v w : V} (p : G.Walk u v) (p' : G.Walk v w) :
t ∈ (p.append p').support ↔ t ∈ p.support ∨ t ∈ p'.support := by
simp only [mem_support_iff, mem_tail_support_append_iff]
obtain rfl | h := eq_or_ne t v <;> obtain rfl | h' := eq_or_ne t u <;>
-- this `have` triggers the unusedHavesSuffices linter:
(try have := h'.symm) <;> simp [*]
#align simple_graph.walk.mem_support_append_iff SimpleGraph.Walk.mem_support_append_iff
@[simp]
theorem subset_support_append_left {V : Type u} {G : SimpleGraph V} {u v w : V}
(p : G.Walk u v) (q : G.Walk v w) : p.support ⊆ (p.append q).support := by
simp only [Walk.support_append, List.subset_append_left]
#align simple_graph.walk.subset_support_append_left SimpleGraph.Walk.subset_support_append_left
@[simp]
theorem subset_support_append_right {V : Type u} {G : SimpleGraph V} {u v w : V}
(p : G.Walk u v) (q : G.Walk v w) : q.support ⊆ (p.append q).support := by
intro h
simp (config := { contextual := true }) only [mem_support_append_iff, or_true_iff, imp_true_iff]
#align simple_graph.walk.subset_support_append_right SimpleGraph.Walk.subset_support_append_right
theorem coe_support {u v : V} (p : G.Walk u v) :
(p.support : Multiset V) = {u} + p.support.tail := by cases p <;> rfl
#align simple_graph.walk.coe_support SimpleGraph.Walk.coe_support
theorem coe_support_append {u v w : V} (p : G.Walk u v) (p' : G.Walk v w) :
((p.append p').support : Multiset V) = {u} + p.support.tail + p'.support.tail := by
rw [support_append, ← Multiset.coe_add, coe_support]
#align simple_graph.walk.coe_support_append SimpleGraph.Walk.coe_support_append
theorem coe_support_append' [DecidableEq V] {u v w : V} (p : G.Walk u v) (p' : G.Walk v w) :
((p.append p').support : Multiset V) = p.support + p'.support - {v} := by
rw [support_append, ← Multiset.coe_add]
simp only [coe_support]
rw [add_comm ({v} : Multiset V)]
simp only [← add_assoc, add_tsub_cancel_right]
#align simple_graph.walk.coe_support_append' SimpleGraph.Walk.coe_support_append'
theorem chain_adj_support {u v w : V} (h : G.Adj u v) :
∀ (p : G.Walk v w), List.Chain G.Adj u p.support
| nil => List.Chain.cons h List.Chain.nil
| cons h' p => List.Chain.cons h (chain_adj_support h' p)
#align simple_graph.walk.chain_adj_support SimpleGraph.Walk.chain_adj_support
theorem chain'_adj_support {u v : V} : ∀ (p : G.Walk u v), List.Chain' G.Adj p.support
| nil => List.Chain.nil
| cons h p => chain_adj_support h p
#align simple_graph.walk.chain'_adj_support SimpleGraph.Walk.chain'_adj_support
theorem chain_dartAdj_darts {d : G.Dart} {v w : V} (h : d.snd = v) (p : G.Walk v w) :
List.Chain G.DartAdj d p.darts := by
induction p generalizing d with
| nil => exact List.Chain.nil
-- Porting note: needed to defer `h` and `rfl` to help elaboration
| cons h' p ih => exact List.Chain.cons (by exact h) (ih (by rfl))
#align simple_graph.walk.chain_dart_adj_darts SimpleGraph.Walk.chain_dartAdj_darts
theorem chain'_dartAdj_darts {u v : V} : ∀ (p : G.Walk u v), List.Chain' G.DartAdj p.darts
| nil => trivial
-- Porting note: needed to defer `rfl` to help elaboration
| cons h p => chain_dartAdj_darts (by rfl) p
#align simple_graph.walk.chain'_dart_adj_darts SimpleGraph.Walk.chain'_dartAdj_darts
theorem edges_subset_edgeSet {u v : V} :
∀ (p : G.Walk u v) ⦃e : Sym2 V⦄, e ∈ p.edges → e ∈ G.edgeSet
| cons h' p', e, h => by
cases h
· exact h'
next h' => exact edges_subset_edgeSet p' h'
#align simple_graph.walk.edges_subset_edge_set SimpleGraph.Walk.edges_subset_edgeSet
theorem adj_of_mem_edges {u v x y : V} (p : G.Walk u v) (h : s(x, y) ∈ p.edges) : G.Adj x y :=
edges_subset_edgeSet p h
#align simple_graph.walk.adj_of_mem_edges SimpleGraph.Walk.adj_of_mem_edges
@[simp]
theorem darts_nil {u : V} : (nil : G.Walk u u).darts = [] := rfl
#align simple_graph.walk.darts_nil SimpleGraph.Walk.darts_nil
@[simp]
theorem darts_cons {u v w : V} (h : G.Adj u v) (p : G.Walk v w) :
(cons h p).darts = ⟨(u, v), h⟩ :: p.darts := rfl
#align simple_graph.walk.darts_cons SimpleGraph.Walk.darts_cons
@[simp]
theorem darts_concat {u v w : V} (p : G.Walk u v) (h : G.Adj v w) :
(p.concat h).darts = p.darts.concat ⟨(v, w), h⟩ := by
induction p <;> simp [*, concat_nil]
#align simple_graph.walk.darts_concat SimpleGraph.Walk.darts_concat
@[simp]
theorem darts_copy {u v u' v'} (p : G.Walk u v) (hu : u = u') (hv : v = v') :
(p.copy hu hv).darts = p.darts := by
subst_vars
rfl
#align simple_graph.walk.darts_copy SimpleGraph.Walk.darts_copy
@[simp]
theorem darts_append {u v w : V} (p : G.Walk u v) (p' : G.Walk v w) :
(p.append p').darts = p.darts ++ p'.darts := by
induction p <;> simp [*]
#align simple_graph.walk.darts_append SimpleGraph.Walk.darts_append
@[simp]
theorem darts_reverse {u v : V} (p : G.Walk u v) :
p.reverse.darts = (p.darts.map Dart.symm).reverse := by
induction p <;> simp [*, Sym2.eq_swap]
#align simple_graph.walk.darts_reverse SimpleGraph.Walk.darts_reverse
theorem mem_darts_reverse {u v : V} {d : G.Dart} {p : G.Walk u v} :
d ∈ p.reverse.darts ↔ d.symm ∈ p.darts := by simp
#align simple_graph.walk.mem_darts_reverse SimpleGraph.Walk.mem_darts_reverse
theorem cons_map_snd_darts {u v : V} (p : G.Walk u v) : (u :: p.darts.map (·.snd)) = p.support := by
induction p <;> simp! [*]
#align simple_graph.walk.cons_map_snd_darts SimpleGraph.Walk.cons_map_snd_darts
theorem map_snd_darts {u v : V} (p : G.Walk u v) : p.darts.map (·.snd) = p.support.tail := by
simpa using congr_arg List.tail (cons_map_snd_darts p)
#align simple_graph.walk.map_snd_darts SimpleGraph.Walk.map_snd_darts
theorem map_fst_darts_append {u v : V} (p : G.Walk u v) :
p.darts.map (·.fst) ++ [v] = p.support := by
induction p <;> simp! [*]
#align simple_graph.walk.map_fst_darts_append SimpleGraph.Walk.map_fst_darts_append
theorem map_fst_darts {u v : V} (p : G.Walk u v) : p.darts.map (·.fst) = p.support.dropLast := by
simpa! using congr_arg List.dropLast (map_fst_darts_append p)
#align simple_graph.walk.map_fst_darts SimpleGraph.Walk.map_fst_darts
@[simp]
theorem edges_nil {u : V} : (nil : G.Walk u u).edges = [] := rfl
#align simple_graph.walk.edges_nil SimpleGraph.Walk.edges_nil
@[simp]
theorem edges_cons {u v w : V} (h : G.Adj u v) (p : G.Walk v w) :
(cons h p).edges = s(u, v) :: p.edges := rfl
#align simple_graph.walk.edges_cons SimpleGraph.Walk.edges_cons
@[simp]
theorem edges_concat {u v w : V} (p : G.Walk u v) (h : G.Adj v w) :
(p.concat h).edges = p.edges.concat s(v, w) := by simp [edges]
#align simple_graph.walk.edges_concat SimpleGraph.Walk.edges_concat
@[simp]
theorem edges_copy {u v u' v'} (p : G.Walk u v) (hu : u = u') (hv : v = v') :
(p.copy hu hv).edges = p.edges := by
subst_vars
rfl
#align simple_graph.walk.edges_copy SimpleGraph.Walk.edges_copy
@[simp]
theorem edges_append {u v w : V} (p : G.Walk u v) (p' : G.Walk v w) :
(p.append p').edges = p.edges ++ p'.edges := by simp [edges]
#align simple_graph.walk.edges_append SimpleGraph.Walk.edges_append
@[simp]
theorem edges_reverse {u v : V} (p : G.Walk u v) : p.reverse.edges = p.edges.reverse := by
simp [edges, List.map_reverse]
#align simple_graph.walk.edges_reverse SimpleGraph.Walk.edges_reverse
@[simp]
theorem length_support {u v : V} (p : G.Walk u v) : p.support.length = p.length + 1 := by
induction p <;> simp [*]
#align simple_graph.walk.length_support SimpleGraph.Walk.length_support
@[simp]
theorem length_darts {u v : V} (p : G.Walk u v) : p.darts.length = p.length := by
induction p <;> simp [*]
#align simple_graph.walk.length_darts SimpleGraph.Walk.length_darts
@[simp]
| Mathlib/Combinatorics/SimpleGraph/Connectivity.lean | 798 | 798 | theorem length_edges {u v : V} (p : G.Walk u v) : p.edges.length = p.length := by | simp [edges]
|
import Mathlib.Algebra.Order.Ring.WithTop
import Mathlib.Algebra.Order.Sub.WithTop
import Mathlib.Data.Real.NNReal
import Mathlib.Order.Interval.Set.WithBotTop
#align_import data.real.ennreal from "leanprover-community/mathlib"@"c14c8fcde993801fca8946b0d80131a1a81d1520"
open Function Set NNReal
variable {α : Type*}
def ENNReal := WithTop ℝ≥0
deriving Zero, AddCommMonoidWithOne, SemilatticeSup, DistribLattice, Nontrivial
#align ennreal ENNReal
@[inherit_doc]
scoped[ENNReal] notation "ℝ≥0∞" => ENNReal
scoped[ENNReal] notation "∞" => (⊤ : ENNReal)
namespace ENNReal
instance : OrderBot ℝ≥0∞ := inferInstanceAs (OrderBot (WithTop ℝ≥0))
instance : BoundedOrder ℝ≥0∞ := inferInstanceAs (BoundedOrder (WithTop ℝ≥0))
instance : CharZero ℝ≥0∞ := inferInstanceAs (CharZero (WithTop ℝ≥0))
noncomputable instance : CanonicallyOrderedCommSemiring ℝ≥0∞ :=
inferInstanceAs (CanonicallyOrderedCommSemiring (WithTop ℝ≥0))
noncomputable instance : CompleteLinearOrder ℝ≥0∞ :=
inferInstanceAs (CompleteLinearOrder (WithTop ℝ≥0))
instance : DenselyOrdered ℝ≥0∞ := inferInstanceAs (DenselyOrdered (WithTop ℝ≥0))
noncomputable instance : CanonicallyLinearOrderedAddCommMonoid ℝ≥0∞ :=
inferInstanceAs (CanonicallyLinearOrderedAddCommMonoid (WithTop ℝ≥0))
noncomputable instance instSub : Sub ℝ≥0∞ := inferInstanceAs (Sub (WithTop ℝ≥0))
noncomputable instance : OrderedSub ℝ≥0∞ := inferInstanceAs (OrderedSub (WithTop ℝ≥0))
noncomputable instance : LinearOrderedAddCommMonoidWithTop ℝ≥0∞ :=
inferInstanceAs (LinearOrderedAddCommMonoidWithTop (WithTop ℝ≥0))
-- Porting note: rfc: redefine using pattern matching?
noncomputable instance : Inv ℝ≥0∞ := ⟨fun a => sInf { b | 1 ≤ a * b }⟩
noncomputable instance : DivInvMonoid ℝ≥0∞ where
variable {a b c d : ℝ≥0∞} {r p q : ℝ≥0}
-- Porting note: are these 2 instances still required in Lean 4?
instance covariantClass_mul_le : CovariantClass ℝ≥0∞ ℝ≥0∞ (· * ·) (· ≤ ·) := inferInstance
#align ennreal.covariant_class_mul_le ENNReal.covariantClass_mul_le
instance covariantClass_add_le : CovariantClass ℝ≥0∞ ℝ≥0∞ (· + ·) (· ≤ ·) := inferInstance
#align ennreal.covariant_class_add_le ENNReal.covariantClass_add_le
-- Porting note (#11215): TODO: add a `WithTop` instance and use it here
noncomputable instance : LinearOrderedCommMonoidWithZero ℝ≥0∞ :=
{ inferInstanceAs (LinearOrderedAddCommMonoidWithTop ℝ≥0∞),
inferInstanceAs (CommSemiring ℝ≥0∞) with
mul_le_mul_left := fun _ _ => mul_le_mul_left'
zero_le_one := zero_le 1 }
noncomputable instance : Unique (AddUnits ℝ≥0∞) where
default := 0
uniq a := AddUnits.ext <| le_zero_iff.1 <| by rw [← a.add_neg]; exact le_self_add
instance : Inhabited ℝ≥0∞ := ⟨0⟩
@[coe, match_pattern] def ofNNReal : ℝ≥0 → ℝ≥0∞ := WithTop.some
instance : Coe ℝ≥0 ℝ≥0∞ := ⟨ofNNReal⟩
@[elab_as_elim, induction_eliminator, cases_eliminator]
def recTopCoe {C : ℝ≥0∞ → Sort*} (top : C ∞) (coe : ∀ x : ℝ≥0, C x) (x : ℝ≥0∞) : C x :=
WithTop.recTopCoe top coe x
instance canLift : CanLift ℝ≥0∞ ℝ≥0 ofNNReal (· ≠ ∞) := WithTop.canLift
#align ennreal.can_lift ENNReal.canLift
@[simp] theorem none_eq_top : (none : ℝ≥0∞) = ∞ := rfl
#align ennreal.none_eq_top ENNReal.none_eq_top
@[simp] theorem some_eq_coe (a : ℝ≥0) : (Option.some a : ℝ≥0∞) = (↑a : ℝ≥0∞) := rfl
#align ennreal.some_eq_coe ENNReal.some_eq_coe
@[simp] theorem some_eq_coe' (a : ℝ≥0) : (WithTop.some a : ℝ≥0∞) = (↑a : ℝ≥0∞) := rfl
lemma coe_injective : Injective ((↑) : ℝ≥0 → ℝ≥0∞) := WithTop.coe_injective
@[simp, norm_cast] lemma coe_inj : (p : ℝ≥0∞) = q ↔ p = q := coe_injective.eq_iff
#align ennreal.coe_eq_coe ENNReal.coe_inj
lemma coe_ne_coe : (p : ℝ≥0∞) ≠ q ↔ p ≠ q := coe_inj.not
theorem range_coe' : range ofNNReal = Iio ∞ := WithTop.range_coe
theorem range_coe : range ofNNReal = {∞}ᶜ := (isCompl_range_some_none ℝ≥0).symm.compl_eq.symm
protected def toNNReal : ℝ≥0∞ → ℝ≥0 := WithTop.untop' 0
#align ennreal.to_nnreal ENNReal.toNNReal
protected def toReal (a : ℝ≥0∞) : Real := a.toNNReal
#align ennreal.to_real ENNReal.toReal
protected noncomputable def ofReal (r : Real) : ℝ≥0∞ := r.toNNReal
#align ennreal.of_real ENNReal.ofReal
@[simp, norm_cast]
theorem toNNReal_coe : (r : ℝ≥0∞).toNNReal = r := rfl
#align ennreal.to_nnreal_coe ENNReal.toNNReal_coe
@[simp]
theorem coe_toNNReal : ∀ {a : ℝ≥0∞}, a ≠ ∞ → ↑a.toNNReal = a
| ofNNReal _, _ => rfl
| ⊤, h => (h rfl).elim
#align ennreal.coe_to_nnreal ENNReal.coe_toNNReal
@[simp]
theorem ofReal_toReal {a : ℝ≥0∞} (h : a ≠ ∞) : ENNReal.ofReal a.toReal = a := by
simp [ENNReal.toReal, ENNReal.ofReal, h]
#align ennreal.of_real_to_real ENNReal.ofReal_toReal
@[simp]
theorem toReal_ofReal {r : ℝ} (h : 0 ≤ r) : (ENNReal.ofReal r).toReal = r :=
max_eq_left h
#align ennreal.to_real_of_real ENNReal.toReal_ofReal
theorem toReal_ofReal' {r : ℝ} : (ENNReal.ofReal r).toReal = max r 0 := rfl
#align ennreal.to_real_of_real' ENNReal.toReal_ofReal'
theorem coe_toNNReal_le_self : ∀ {a : ℝ≥0∞}, ↑a.toNNReal ≤ a
| ofNNReal r => by rw [toNNReal_coe]
| ⊤ => le_top
#align ennreal.coe_to_nnreal_le_self ENNReal.coe_toNNReal_le_self
theorem coe_nnreal_eq (r : ℝ≥0) : (r : ℝ≥0∞) = ENNReal.ofReal r := by
rw [ENNReal.ofReal, Real.toNNReal_coe]
#align ennreal.coe_nnreal_eq ENNReal.coe_nnreal_eq
theorem ofReal_eq_coe_nnreal {x : ℝ} (h : 0 ≤ x) :
ENNReal.ofReal x = ofNNReal ⟨x, h⟩ :=
(coe_nnreal_eq ⟨x, h⟩).symm
#align ennreal.of_real_eq_coe_nnreal ENNReal.ofReal_eq_coe_nnreal
@[simp] theorem ofReal_coe_nnreal : ENNReal.ofReal p = p := (coe_nnreal_eq p).symm
#align ennreal.of_real_coe_nnreal ENNReal.ofReal_coe_nnreal
@[simp, norm_cast] theorem coe_zero : ↑(0 : ℝ≥0) = (0 : ℝ≥0∞) := rfl
#align ennreal.coe_zero ENNReal.coe_zero
@[simp, norm_cast] theorem coe_one : ↑(1 : ℝ≥0) = (1 : ℝ≥0∞) := rfl
#align ennreal.coe_one ENNReal.coe_one
@[simp] theorem toReal_nonneg {a : ℝ≥0∞} : 0 ≤ a.toReal := a.toNNReal.2
#align ennreal.to_real_nonneg ENNReal.toReal_nonneg
@[simp] theorem top_toNNReal : ∞.toNNReal = 0 := rfl
#align ennreal.top_to_nnreal ENNReal.top_toNNReal
@[simp] theorem top_toReal : ∞.toReal = 0 := rfl
#align ennreal.top_to_real ENNReal.top_toReal
@[simp] theorem one_toReal : (1 : ℝ≥0∞).toReal = 1 := rfl
#align ennreal.one_to_real ENNReal.one_toReal
@[simp] theorem one_toNNReal : (1 : ℝ≥0∞).toNNReal = 1 := rfl
#align ennreal.one_to_nnreal ENNReal.one_toNNReal
@[simp] theorem coe_toReal (r : ℝ≥0) : (r : ℝ≥0∞).toReal = r := rfl
#align ennreal.coe_to_real ENNReal.coe_toReal
@[simp] theorem zero_toNNReal : (0 : ℝ≥0∞).toNNReal = 0 := rfl
#align ennreal.zero_to_nnreal ENNReal.zero_toNNReal
@[simp] theorem zero_toReal : (0 : ℝ≥0∞).toReal = 0 := rfl
#align ennreal.zero_to_real ENNReal.zero_toReal
@[simp] theorem ofReal_zero : ENNReal.ofReal (0 : ℝ) = 0 := by simp [ENNReal.ofReal]
#align ennreal.of_real_zero ENNReal.ofReal_zero
@[simp] theorem ofReal_one : ENNReal.ofReal (1 : ℝ) = (1 : ℝ≥0∞) := by simp [ENNReal.ofReal]
#align ennreal.of_real_one ENNReal.ofReal_one
theorem ofReal_toReal_le {a : ℝ≥0∞} : ENNReal.ofReal a.toReal ≤ a :=
if ha : a = ∞ then ha.symm ▸ le_top else le_of_eq (ofReal_toReal ha)
#align ennreal.of_real_to_real_le ENNReal.ofReal_toReal_le
theorem forall_ennreal {p : ℝ≥0∞ → Prop} : (∀ a, p a) ↔ (∀ r : ℝ≥0, p r) ∧ p ∞ :=
Option.forall.trans and_comm
#align ennreal.forall_ennreal ENNReal.forall_ennreal
theorem forall_ne_top {p : ℝ≥0∞ → Prop} : (∀ a, a ≠ ∞ → p a) ↔ ∀ r : ℝ≥0, p r :=
Option.ball_ne_none
#align ennreal.forall_ne_top ENNReal.forall_ne_top
theorem exists_ne_top {p : ℝ≥0∞ → Prop} : (∃ a ≠ ∞, p a) ↔ ∃ r : ℝ≥0, p r :=
Option.exists_ne_none
#align ennreal.exists_ne_top ENNReal.exists_ne_top
theorem toNNReal_eq_zero_iff (x : ℝ≥0∞) : x.toNNReal = 0 ↔ x = 0 ∨ x = ∞ :=
WithTop.untop'_eq_self_iff
#align ennreal.to_nnreal_eq_zero_iff ENNReal.toNNReal_eq_zero_iff
theorem toReal_eq_zero_iff (x : ℝ≥0∞) : x.toReal = 0 ↔ x = 0 ∨ x = ∞ := by
simp [ENNReal.toReal, toNNReal_eq_zero_iff]
#align ennreal.to_real_eq_zero_iff ENNReal.toReal_eq_zero_iff
theorem toNNReal_ne_zero : a.toNNReal ≠ 0 ↔ a ≠ 0 ∧ a ≠ ∞ :=
a.toNNReal_eq_zero_iff.not.trans not_or
#align ennreal.to_nnreal_ne_zero ENNReal.toNNReal_ne_zero
theorem toReal_ne_zero : a.toReal ≠ 0 ↔ a ≠ 0 ∧ a ≠ ∞ :=
a.toReal_eq_zero_iff.not.trans not_or
#align ennreal.to_real_ne_zero ENNReal.toReal_ne_zero
theorem toNNReal_eq_one_iff (x : ℝ≥0∞) : x.toNNReal = 1 ↔ x = 1 :=
WithTop.untop'_eq_iff.trans <| by simp
#align ennreal.to_nnreal_eq_one_iff ENNReal.toNNReal_eq_one_iff
theorem toReal_eq_one_iff (x : ℝ≥0∞) : x.toReal = 1 ↔ x = 1 := by
rw [ENNReal.toReal, NNReal.coe_eq_one, ENNReal.toNNReal_eq_one_iff]
#align ennreal.to_real_eq_one_iff ENNReal.toReal_eq_one_iff
theorem toNNReal_ne_one : a.toNNReal ≠ 1 ↔ a ≠ 1 :=
a.toNNReal_eq_one_iff.not
#align ennreal.to_nnreal_ne_one ENNReal.toNNReal_ne_one
theorem toReal_ne_one : a.toReal ≠ 1 ↔ a ≠ 1 :=
a.toReal_eq_one_iff.not
#align ennreal.to_real_ne_one ENNReal.toReal_ne_one
@[simp] theorem coe_ne_top : (r : ℝ≥0∞) ≠ ∞ := WithTop.coe_ne_top
#align ennreal.coe_ne_top ENNReal.coe_ne_top
@[simp] theorem top_ne_coe : ∞ ≠ (r : ℝ≥0∞) := WithTop.top_ne_coe
#align ennreal.top_ne_coe ENNReal.top_ne_coe
@[simp] theorem coe_lt_top : (r : ℝ≥0∞) < ∞ := WithTop.coe_lt_top r
#align ennreal.coe_lt_top ENNReal.coe_lt_top
@[simp] theorem ofReal_ne_top {r : ℝ} : ENNReal.ofReal r ≠ ∞ := coe_ne_top
#align ennreal.of_real_ne_top ENNReal.ofReal_ne_top
@[simp] theorem ofReal_lt_top {r : ℝ} : ENNReal.ofReal r < ∞ := coe_lt_top
#align ennreal.of_real_lt_top ENNReal.ofReal_lt_top
@[simp] theorem top_ne_ofReal {r : ℝ} : ∞ ≠ ENNReal.ofReal r := top_ne_coe
#align ennreal.top_ne_of_real ENNReal.top_ne_ofReal
@[simp]
theorem ofReal_toReal_eq_iff : ENNReal.ofReal a.toReal = a ↔ a ≠ ⊤ :=
⟨fun h => by
rw [← h]
exact ofReal_ne_top, ofReal_toReal⟩
#align ennreal.of_real_to_real_eq_iff ENNReal.ofReal_toReal_eq_iff
@[simp]
theorem toReal_ofReal_eq_iff {a : ℝ} : (ENNReal.ofReal a).toReal = a ↔ 0 ≤ a :=
⟨fun h => by
rw [← h]
exact toReal_nonneg, toReal_ofReal⟩
#align ennreal.to_real_of_real_eq_iff ENNReal.toReal_ofReal_eq_iff
@[simp] theorem zero_ne_top : 0 ≠ ∞ := coe_ne_top
#align ennreal.zero_ne_top ENNReal.zero_ne_top
@[simp] theorem top_ne_zero : ∞ ≠ 0 := top_ne_coe
#align ennreal.top_ne_zero ENNReal.top_ne_zero
@[simp] theorem one_ne_top : 1 ≠ ∞ := coe_ne_top
#align ennreal.one_ne_top ENNReal.one_ne_top
@[simp] theorem top_ne_one : ∞ ≠ 1 := top_ne_coe
#align ennreal.top_ne_one ENNReal.top_ne_one
@[simp] theorem zero_lt_top : 0 < ∞ := coe_lt_top
@[simp, norm_cast] theorem coe_le_coe : (↑r : ℝ≥0∞) ≤ ↑q ↔ r ≤ q := WithTop.coe_le_coe
#align ennreal.coe_le_coe ENNReal.coe_le_coe
@[simp, norm_cast] theorem coe_lt_coe : (↑r : ℝ≥0∞) < ↑q ↔ r < q := WithTop.coe_lt_coe
#align ennreal.coe_lt_coe ENNReal.coe_lt_coe
-- Needed until `@[gcongr]` accepts iff statements
alias ⟨_, coe_le_coe_of_le⟩ := coe_le_coe
attribute [gcongr] ENNReal.coe_le_coe_of_le
-- Needed until `@[gcongr]` accepts iff statements
alias ⟨_, coe_lt_coe_of_lt⟩ := coe_lt_coe
attribute [gcongr] ENNReal.coe_lt_coe_of_lt
theorem coe_mono : Monotone ofNNReal := fun _ _ => coe_le_coe.2
#align ennreal.coe_mono ENNReal.coe_mono
theorem coe_strictMono : StrictMono ofNNReal := fun _ _ => coe_lt_coe.2
@[simp, norm_cast] theorem coe_eq_zero : (↑r : ℝ≥0∞) = 0 ↔ r = 0 := coe_inj
#align ennreal.coe_eq_zero ENNReal.coe_eq_zero
@[simp, norm_cast] theorem zero_eq_coe : 0 = (↑r : ℝ≥0∞) ↔ 0 = r := coe_inj
#align ennreal.zero_eq_coe ENNReal.zero_eq_coe
@[simp, norm_cast] theorem coe_eq_one : (↑r : ℝ≥0∞) = 1 ↔ r = 1 := coe_inj
#align ennreal.coe_eq_one ENNReal.coe_eq_one
@[simp, norm_cast] theorem one_eq_coe : 1 = (↑r : ℝ≥0∞) ↔ 1 = r := coe_inj
#align ennreal.one_eq_coe ENNReal.one_eq_coe
@[simp, norm_cast] theorem coe_pos : 0 < (r : ℝ≥0∞) ↔ 0 < r := coe_lt_coe
#align ennreal.coe_pos ENNReal.coe_pos
theorem coe_ne_zero : (r : ℝ≥0∞) ≠ 0 ↔ r ≠ 0 := coe_eq_zero.not
#align ennreal.coe_ne_zero ENNReal.coe_ne_zero
lemma coe_ne_one : (r : ℝ≥0∞) ≠ 1 ↔ r ≠ 1 := coe_eq_one.not
@[simp, norm_cast] lemma coe_add (x y : ℝ≥0) : (↑(x + y) : ℝ≥0∞) = x + y := rfl
#align ennreal.coe_add ENNReal.coe_add
@[simp, norm_cast] lemma coe_mul (x y : ℝ≥0) : (↑(x * y) : ℝ≥0∞) = x * y := rfl
#align ennreal.coe_mul ENNReal.coe_mul
@[norm_cast] lemma coe_nsmul (n : ℕ) (x : ℝ≥0) : (↑(n • x) : ℝ≥0∞) = n • x := rfl
@[simp, norm_cast] lemma coe_pow (x : ℝ≥0) (n : ℕ) : (↑(x ^ n) : ℝ≥0∞) = x ^ n := rfl
#noalign ennreal.coe_bit0
#noalign ennreal.coe_bit1
-- See note [no_index around OfNat.ofNat]
@[simp, norm_cast] -- Porting note (#10756): new theorem
theorem coe_ofNat (n : ℕ) [n.AtLeastTwo] :
((no_index (OfNat.ofNat n) : ℝ≥0) : ℝ≥0∞) = OfNat.ofNat n := rfl
-- Porting note (#11215): TODO: add lemmas about `OfNat.ofNat` and `<`/`≤`
theorem coe_two : ((2 : ℝ≥0) : ℝ≥0∞) = 2 := rfl
#align ennreal.coe_two ENNReal.coe_two
theorem toNNReal_eq_toNNReal_iff (x y : ℝ≥0∞) :
x.toNNReal = y.toNNReal ↔ x = y ∨ x = 0 ∧ y = ⊤ ∨ x = ⊤ ∧ y = 0 :=
WithTop.untop'_eq_untop'_iff
#align ennreal.to_nnreal_eq_to_nnreal_iff ENNReal.toNNReal_eq_toNNReal_iff
theorem toReal_eq_toReal_iff (x y : ℝ≥0∞) :
x.toReal = y.toReal ↔ x = y ∨ x = 0 ∧ y = ⊤ ∨ x = ⊤ ∧ y = 0 := by
simp only [ENNReal.toReal, NNReal.coe_inj, toNNReal_eq_toNNReal_iff]
#align ennreal.to_real_eq_to_real_iff ENNReal.toReal_eq_toReal_iff
theorem toNNReal_eq_toNNReal_iff' {x y : ℝ≥0∞} (hx : x ≠ ⊤) (hy : y ≠ ⊤) :
x.toNNReal = y.toNNReal ↔ x = y := by
simp only [ENNReal.toNNReal_eq_toNNReal_iff x y, hx, hy, and_false, false_and, or_false]
#align ennreal.to_nnreal_eq_to_nnreal_iff' ENNReal.toNNReal_eq_toNNReal_iff'
theorem toReal_eq_toReal_iff' {x y : ℝ≥0∞} (hx : x ≠ ⊤) (hy : y ≠ ⊤) :
x.toReal = y.toReal ↔ x = y := by
simp only [ENNReal.toReal, NNReal.coe_inj, toNNReal_eq_toNNReal_iff' hx hy]
#align ennreal.to_real_eq_to_real_iff' ENNReal.toReal_eq_toReal_iff'
theorem one_lt_two : (1 : ℝ≥0∞) < 2 := Nat.one_lt_ofNat
#align ennreal.one_lt_two ENNReal.one_lt_two
@[simp] theorem two_ne_top : (2 : ℝ≥0∞) ≠ ∞ := coe_ne_top
#align ennreal.two_ne_top ENNReal.two_ne_top
@[simp] theorem two_lt_top : (2 : ℝ≥0∞) < ∞ := coe_lt_top
instance _root_.fact_one_le_one_ennreal : Fact ((1 : ℝ≥0∞) ≤ 1) :=
⟨le_rfl⟩
#align fact_one_le_one_ennreal fact_one_le_one_ennreal
instance _root_.fact_one_le_two_ennreal : Fact ((1 : ℝ≥0∞) ≤ 2) :=
⟨one_le_two⟩
#align fact_one_le_two_ennreal fact_one_le_two_ennreal
instance _root_.fact_one_le_top_ennreal : Fact ((1 : ℝ≥0∞) ≤ ∞) :=
⟨le_top⟩
#align fact_one_le_top_ennreal fact_one_le_top_ennreal
def neTopEquivNNReal : { a | a ≠ ∞ } ≃ ℝ≥0 where
toFun x := ENNReal.toNNReal x
invFun x := ⟨x, coe_ne_top⟩
left_inv := fun x => Subtype.eq <| coe_toNNReal x.2
right_inv _ := toNNReal_coe
#align ennreal.ne_top_equiv_nnreal ENNReal.neTopEquivNNReal
theorem cinfi_ne_top [InfSet α] (f : ℝ≥0∞ → α) : ⨅ x : { x // x ≠ ∞ }, f x = ⨅ x : ℝ≥0, f x :=
Eq.symm <| neTopEquivNNReal.symm.surjective.iInf_congr _ fun _ => rfl
#align ennreal.cinfi_ne_top ENNReal.cinfi_ne_top
| Mathlib/Data/ENNReal/Basic.lean | 488 | 489 | theorem iInf_ne_top [CompleteLattice α] (f : ℝ≥0∞ → α) :
⨅ (x) (_ : x ≠ ∞), f x = ⨅ x : ℝ≥0, f x := by | rw [iInf_subtype', cinfi_ne_top]
|
import Mathlib.Data.Fin.VecNotation
import Mathlib.SetTheory.Cardinal.Basic
#align_import model_theory.basic from "leanprover-community/mathlib"@"369525b73f229ccd76a6ec0e0e0bf2be57599768"
set_option autoImplicit true
universe u v u' v' w w'
open Cardinal
open Cardinal
namespace FirstOrder
-- intended to be used with explicit universe parameters
@[nolint checkUnivs]
structure Language where
Functions : ℕ → Type u
Relations : ℕ → Type v
#align first_order.language FirstOrder.Language
--@[simp]
def Sequence₂ (a₀ a₁ a₂ : Type u) : ℕ → Type u
| 0 => a₀
| 1 => a₁
| 2 => a₂
| _ => PEmpty
#align first_order.sequence₂ FirstOrder.Sequence₂
namespace Language
@[simps]
protected def mk₂ (c f₁ f₂ : Type u) (r₁ r₂ : Type v) : Language :=
⟨Sequence₂ c f₁ f₂, Sequence₂ PEmpty r₁ r₂⟩
#align first_order.language.mk₂ FirstOrder.Language.mk₂
protected def empty : Language :=
⟨fun _ => Empty, fun _ => Empty⟩
#align first_order.language.empty FirstOrder.Language.empty
instance : Inhabited Language :=
⟨Language.empty⟩
protected def sum (L : Language.{u, v}) (L' : Language.{u', v'}) : Language :=
⟨fun n => Sum (L.Functions n) (L'.Functions n), fun n => Sum (L.Relations n) (L'.Relations n)⟩
#align first_order.language.sum FirstOrder.Language.sum
variable (L : Language.{u, v})
-- Porting note(#5171): this linter isn't ported yet.
-- @[nolint has_nonempty_instance]
protected def Constants :=
L.Functions 0
#align first_order.language.constants FirstOrder.Language.Constants
@[simp]
theorem constants_mk₂ (c f₁ f₂ : Type u) (r₁ r₂ : Type v) :
(Language.mk₂ c f₁ f₂ r₁ r₂).Constants = c :=
rfl
#align first_order.language.constants_mk₂ FirstOrder.Language.constants_mk₂
-- Porting note(#5171): this linter isn't ported yet.
-- @[nolint has_nonempty_instance]
def Symbols :=
Sum (Σl, L.Functions l) (Σl, L.Relations l)
#align first_order.language.symbols FirstOrder.Language.Symbols
def card : Cardinal :=
#L.Symbols
#align first_order.language.card FirstOrder.Language.card
class IsRelational : Prop where
empty_functions : ∀ n, IsEmpty (L.Functions n)
#align first_order.language.is_relational FirstOrder.Language.IsRelational
class IsAlgebraic : Prop where
empty_relations : ∀ n, IsEmpty (L.Relations n)
#align first_order.language.is_algebraic FirstOrder.Language.IsAlgebraic
variable {L} {L' : Language.{u', v'}}
theorem card_eq_card_functions_add_card_relations :
L.card =
(Cardinal.sum fun l => Cardinal.lift.{v} #(L.Functions l)) +
Cardinal.sum fun l => Cardinal.lift.{u} #(L.Relations l) := by
simp [card, Symbols]
#align first_order.language.card_eq_card_functions_add_card_relations FirstOrder.Language.card_eq_card_functions_add_card_relations
instance [L.IsRelational] {n : ℕ} : IsEmpty (L.Functions n) :=
IsRelational.empty_functions n
instance [L.IsAlgebraic] {n : ℕ} : IsEmpty (L.Relations n) :=
IsAlgebraic.empty_relations n
instance isRelational_of_empty_functions {symb : ℕ → Type*} :
IsRelational ⟨fun _ => Empty, symb⟩ :=
⟨fun _ => instIsEmptyEmpty⟩
#align first_order.language.is_relational_of_empty_functions FirstOrder.Language.isRelational_of_empty_functions
instance isAlgebraic_of_empty_relations {symb : ℕ → Type*} : IsAlgebraic ⟨symb, fun _ => Empty⟩ :=
⟨fun _ => instIsEmptyEmpty⟩
#align first_order.language.is_algebraic_of_empty_relations FirstOrder.Language.isAlgebraic_of_empty_relations
instance isRelational_empty : IsRelational Language.empty :=
Language.isRelational_of_empty_functions
#align first_order.language.is_relational_empty FirstOrder.Language.isRelational_empty
instance isAlgebraic_empty : IsAlgebraic Language.empty :=
Language.isAlgebraic_of_empty_relations
#align first_order.language.is_algebraic_empty FirstOrder.Language.isAlgebraic_empty
instance isRelational_sum [L.IsRelational] [L'.IsRelational] : IsRelational (L.sum L') :=
⟨fun _ => instIsEmptySum⟩
#align first_order.language.is_relational_sum FirstOrder.Language.isRelational_sum
instance isAlgebraic_sum [L.IsAlgebraic] [L'.IsAlgebraic] : IsAlgebraic (L.sum L') :=
⟨fun _ => instIsEmptySum⟩
#align first_order.language.is_algebraic_sum FirstOrder.Language.isAlgebraic_sum
instance isRelational_mk₂ {c f₁ f₂ : Type u} {r₁ r₂ : Type v} [h0 : IsEmpty c] [h1 : IsEmpty f₁]
[h2 : IsEmpty f₂] : IsRelational (Language.mk₂ c f₁ f₂ r₁ r₂) :=
⟨fun n =>
Nat.casesOn n h0 fun n => Nat.casesOn n h1 fun n => Nat.casesOn n h2 fun _ =>
inferInstanceAs (IsEmpty PEmpty)⟩
#align first_order.language.is_relational_mk₂ FirstOrder.Language.isRelational_mk₂
instance isAlgebraic_mk₂ {c f₁ f₂ : Type u} {r₁ r₂ : Type v} [h1 : IsEmpty r₁] [h2 : IsEmpty r₂] :
IsAlgebraic (Language.mk₂ c f₁ f₂ r₁ r₂) :=
⟨fun n =>
Nat.casesOn n (inferInstanceAs (IsEmpty PEmpty)) fun n =>
Nat.casesOn n h1 fun n => Nat.casesOn n h2 fun _ => inferInstanceAs (IsEmpty PEmpty)⟩
#align first_order.language.is_algebraic_mk₂ FirstOrder.Language.isAlgebraic_mk₂
instance subsingleton_mk₂_functions {c f₁ f₂ : Type u} {r₁ r₂ : Type v} [h0 : Subsingleton c]
[h1 : Subsingleton f₁] [h2 : Subsingleton f₂] {n : ℕ} :
Subsingleton ((Language.mk₂ c f₁ f₂ r₁ r₂).Functions n) :=
Nat.casesOn n h0 fun n =>
Nat.casesOn n h1 fun n => Nat.casesOn n h2 fun _ => ⟨fun x => PEmpty.elim x⟩
#align first_order.language.subsingleton_mk₂_functions FirstOrder.Language.subsingleton_mk₂_functions
instance subsingleton_mk₂_relations {c f₁ f₂ : Type u} {r₁ r₂ : Type v} [h1 : Subsingleton r₁]
[h2 : Subsingleton r₂] {n : ℕ} : Subsingleton ((Language.mk₂ c f₁ f₂ r₁ r₂).Relations n) :=
Nat.casesOn n ⟨fun x => PEmpty.elim x⟩ fun n =>
Nat.casesOn n h1 fun n => Nat.casesOn n h2 fun _ => ⟨fun x => PEmpty.elim x⟩
#align first_order.language.subsingleton_mk₂_relations FirstOrder.Language.subsingleton_mk₂_relations
@[simp]
theorem empty_card : Language.empty.card = 0 := by simp [card_eq_card_functions_add_card_relations]
#align first_order.language.empty_card FirstOrder.Language.empty_card
instance isEmpty_empty : IsEmpty Language.empty.Symbols := by
simp only [Language.Symbols, isEmpty_sum, isEmpty_sigma]
exact ⟨fun _ => inferInstance, fun _ => inferInstance⟩
#align first_order.language.is_empty_empty FirstOrder.Language.isEmpty_empty
instance Countable.countable_functions [h : Countable L.Symbols] : Countable (Σl, L.Functions l) :=
@Function.Injective.countable _ _ h _ Sum.inl_injective
#align first_order.language.countable.countable_functions FirstOrder.Language.Countable.countable_functions
@[simp]
theorem card_functions_sum (i : ℕ) :
#((L.sum L').Functions i)
= (Cardinal.lift.{u'} #(L.Functions i) + Cardinal.lift.{u} #(L'.Functions i) : Cardinal) := by
simp [Language.sum]
#align first_order.language.card_functions_sum FirstOrder.Language.card_functions_sum
@[simp]
theorem card_relations_sum (i : ℕ) :
#((L.sum L').Relations i) =
Cardinal.lift.{v'} #(L.Relations i) + Cardinal.lift.{v} #(L'.Relations i) := by
simp [Language.sum]
#align first_order.language.card_relations_sum FirstOrder.Language.card_relations_sum
@[simp]
theorem card_sum :
(L.sum L').card = Cardinal.lift.{max u' v'} L.card + Cardinal.lift.{max u v} L'.card := by
simp only [card_eq_card_functions_add_card_relations, card_functions_sum, card_relations_sum,
sum_add_distrib', lift_add, lift_sum, lift_lift]
simp only [add_assoc, add_comm (Cardinal.sum fun i => (#(L'.Functions i)).lift)]
#align first_order.language.card_sum FirstOrder.Language.card_sum
@[simp]
theorem card_mk₂ (c f₁ f₂ : Type u) (r₁ r₂ : Type v) :
(Language.mk₂ c f₁ f₂ r₁ r₂).card =
Cardinal.lift.{v} #c + Cardinal.lift.{v} #f₁ + Cardinal.lift.{v} #f₂ +
Cardinal.lift.{u} #r₁ + Cardinal.lift.{u} #r₂ := by
simp [card_eq_card_functions_add_card_relations, add_assoc]
#align first_order.language.card_mk₂ FirstOrder.Language.card_mk₂
variable (L) (M : Type w)
@[ext]
class Structure where
funMap : ∀ {n}, L.Functions n → (Fin n → M) → M
RelMap : ∀ {n}, L.Relations n → (Fin n → M) → Prop
set_option linter.uppercaseLean3 false in
#align first_order.language.Structure FirstOrder.Language.Structure
set_option linter.uppercaseLean3 false in
#align first_order.language.Structure.fun_map FirstOrder.Language.Structure.funMap
set_option linter.uppercaseLean3 false in
#align first_order.language.Structure.rel_map FirstOrder.Language.Structure.RelMap
variable (N : Type w') [L.Structure M] [L.Structure N]
open Structure
def Inhabited.trivialStructure {α : Type*} [Inhabited α] : L.Structure α :=
⟨default, default⟩
#align first_order.language.inhabited.trivial_structure FirstOrder.Language.Inhabited.trivialStructure
structure Hom where
toFun : M → N
-- Porting note:
-- The autoparam here used to be `obviously`. We would like to replace it with `aesop`
-- but that isn't currently sufficient.
-- See https://leanprover.zulipchat.com/#narrow/stream/287929-mathlib4/topic/Aesop.20and.20cases
-- If that can be improved, we should change this to `by aesop` and remove the proofs below.
map_fun' : ∀ {n} (f : L.Functions n) (x), toFun (funMap f x) = funMap f (toFun ∘ x) := by
intros; trivial
map_rel' : ∀ {n} (r : L.Relations n) (x), RelMap r x → RelMap r (toFun ∘ x) := by
-- Porting note: see porting note on `Hom.map_fun'`
intros; trivial
#align first_order.language.hom FirstOrder.Language.Hom
@[inherit_doc]
scoped[FirstOrder] notation:25 A " →[" L "] " B => FirstOrder.Language.Hom L A B
structure Embedding extends M ↪ N where
map_fun' : ∀ {n} (f : L.Functions n) (x), toFun (funMap f x) = funMap f (toFun ∘ x) := by
-- Porting note: see porting note on `Hom.map_fun'`
intros; trivial
map_rel' : ∀ {n} (r : L.Relations n) (x), RelMap r (toFun ∘ x) ↔ RelMap r x := by
-- Porting note: see porting note on `Hom.map_fun'`
intros; trivial
#align first_order.language.embedding FirstOrder.Language.Embedding
@[inherit_doc]
scoped[FirstOrder] notation:25 A " ↪[" L "] " B => FirstOrder.Language.Embedding L A B
structure Equiv extends M ≃ N where
map_fun' : ∀ {n} (f : L.Functions n) (x), toFun (funMap f x) = funMap f (toFun ∘ x) := by
-- Porting note: see porting note on `Hom.map_fun'`
intros; trivial
map_rel' : ∀ {n} (r : L.Relations n) (x), RelMap r (toFun ∘ x) ↔ RelMap r x := by
-- Porting note: see porting note on `Hom.map_fun'`
intros; trivial
#align first_order.language.equiv FirstOrder.Language.Equiv
@[inherit_doc]
scoped[FirstOrder] notation:25 A " ≃[" L "] " B => FirstOrder.Language.Equiv L A B
-- Porting note: was [L.Structure P] and [L.Structure Q]
-- The former reported an error.
variable {L M N} {P : Type*} [Structure L P] {Q : Type*} [Structure L Q]
-- Porting note (#11445): new definition
@[coe]
def constantMap (c : L.Constants) : M := funMap c default
instance : CoeTC L.Constants M :=
⟨constantMap⟩
theorem funMap_eq_coe_constants {c : L.Constants} {x : Fin 0 → M} : funMap c x = c :=
congr rfl (funext finZeroElim)
#align first_order.language.fun_map_eq_coe_constants FirstOrder.Language.funMap_eq_coe_constants
theorem nonempty_of_nonempty_constants [h : Nonempty L.Constants] : Nonempty M :=
h.map (↑)
#align first_order.language.nonempty_of_nonempty_constants FirstOrder.Language.nonempty_of_nonempty_constants
def funMap₂ {c f₁ f₂ : Type u} {r₁ r₂ : Type v} (c' : c → M) (f₁' : f₁ → M → M)
(f₂' : f₂ → M → M → M) : ∀ {n}, (Language.mk₂ c f₁ f₂ r₁ r₂).Functions n → (Fin n → M) → M
| 0, f, _ => c' f
| 1, f, x => f₁' f (x 0)
| 2, f, x => f₂' f (x 0) (x 1)
| _ + 3, f, _ => PEmpty.elim f
#align first_order.language.fun_map₂ FirstOrder.Language.funMap₂
def RelMap₂ {c f₁ f₂ : Type u} {r₁ r₂ : Type v} (r₁' : r₁ → Set M) (r₂' : r₂ → M → M → Prop) :
∀ {n}, (Language.mk₂ c f₁ f₂ r₁ r₂).Relations n → (Fin n → M) → Prop
| 0, r, _ => PEmpty.elim r
| 1, r, x => x 0 ∈ r₁' r
| 2, r, x => r₂' r (x 0) (x 1)
| _ + 3, r, _ => PEmpty.elim r
#align first_order.language.rel_map₂ FirstOrder.Language.RelMap₂
protected def Structure.mk₂ {c f₁ f₂ : Type u} {r₁ r₂ : Type v} (c' : c → M) (f₁' : f₁ → M → M)
(f₂' : f₂ → M → M → M) (r₁' : r₁ → Set M) (r₂' : r₂ → M → M → Prop) :
(Language.mk₂ c f₁ f₂ r₁ r₂).Structure M :=
⟨funMap₂ c' f₁' f₂', RelMap₂ r₁' r₂'⟩
set_option linter.uppercaseLean3 false in
#align first_order.language.Structure.mk₂ FirstOrder.Language.Structure.mk₂
class HomClass (L : outParam Language) (F M N : Type*)
[FunLike F M N] [L.Structure M] [L.Structure N] : Prop where
map_fun : ∀ (φ : F) {n} (f : L.Functions n) (x), φ (funMap f x) = funMap f (φ ∘ x)
map_rel : ∀ (φ : F) {n} (r : L.Relations n) (x), RelMap r x → RelMap r (φ ∘ x)
#align first_order.language.hom_class FirstOrder.Language.HomClass
class StrongHomClass (L : outParam Language) (F M N : Type*)
[FunLike F M N] [L.Structure M] [L.Structure N] : Prop where
map_fun : ∀ (φ : F) {n} (f : L.Functions n) (x), φ (funMap f x) = funMap f (φ ∘ x)
map_rel : ∀ (φ : F) {n} (r : L.Relations n) (x), RelMap r (φ ∘ x) ↔ RelMap r x
#align first_order.language.strong_hom_class FirstOrder.Language.StrongHomClass
-- Porting note: using implicit brackets for `Structure` arguments
instance (priority := 100) StrongHomClass.homClass [L.Structure M]
[L.Structure N] [FunLike F M N] [StrongHomClass L F M N] : HomClass L F M N where
map_fun := StrongHomClass.map_fun
map_rel φ _ R x := (StrongHomClass.map_rel φ R x).2
#align first_order.language.strong_hom_class.hom_class FirstOrder.Language.StrongHomClass.homClass
theorem HomClass.strongHomClassOfIsAlgebraic [L.IsAlgebraic] {F M N} [L.Structure M] [L.Structure N]
[FunLike F M N] [HomClass L F M N] : StrongHomClass L F M N where
map_fun := HomClass.map_fun
map_rel _ n R _ := (IsAlgebraic.empty_relations n).elim R
#align first_order.language.hom_class.strong_hom_class_of_is_algebraic FirstOrder.Language.HomClass.strongHomClassOfIsAlgebraic
theorem HomClass.map_constants {F M N} [L.Structure M] [L.Structure N] [FunLike F M N]
[HomClass L F M N] (φ : F) (c : L.Constants) : φ c = c :=
(HomClass.map_fun φ c default).trans (congr rfl (funext default))
#align first_order.language.hom_class.map_constants FirstOrder.Language.HomClass.map_constants
attribute [inherit_doc FirstOrder.Language.Hom.map_fun'] FirstOrder.Language.Embedding.map_fun'
FirstOrder.Language.HomClass.map_fun FirstOrder.Language.StrongHomClass.map_fun
FirstOrder.Language.Equiv.map_fun'
attribute [inherit_doc FirstOrder.Language.Hom.map_rel'] FirstOrder.Language.Embedding.map_rel'
FirstOrder.Language.HomClass.map_rel FirstOrder.Language.StrongHomClass.map_rel
FirstOrder.Language.Equiv.map_rel'
def HomClass.toHom {F M N} [L.Structure M] [L.Structure N] [FunLike F M N]
[HomClass L F M N] : F → M →[L] N := fun φ =>
⟨φ, HomClass.map_fun φ, HomClass.map_rel φ⟩
#align first_order.language.hom_class.to_hom FirstOrder.Language.HomClass.toHom
def StrongHomClass.toEmbedding {F M N} [L.Structure M] [L.Structure N] [FunLike F M N]
[EmbeddingLike F M N] [StrongHomClass L F M N] : F → M ↪[L] N := fun φ =>
⟨⟨φ, EmbeddingLike.injective φ⟩, StrongHomClass.map_fun φ, StrongHomClass.map_rel φ⟩
#align first_order.language.strong_hom_class.to_embedding FirstOrder.Language.StrongHomClass.toEmbedding
namespace Equiv
instance : EquivLike (M ≃[L] N) M N where
coe f := f.toFun
inv f := f.invFun
left_inv f := f.left_inv
right_inv f := f.right_inv
coe_injective' f g h₁ h₂ := by
cases f
cases g
simp only [mk.injEq]
ext x
exact Function.funext_iff.1 h₁ x
instance : StrongHomClass L (M ≃[L] N) M N where
map_fun := map_fun'
map_rel := map_rel'
@[symm]
def symm (f : M ≃[L] N) : N ≃[L] M :=
{ f.toEquiv.symm with
map_fun' := fun n f' {x} => by
simp only [Equiv.toFun_as_coe]
rw [Equiv.symm_apply_eq]
refine Eq.trans ?_ (f.map_fun' f' (f.toEquiv.symm ∘ x)).symm
rw [← Function.comp.assoc, Equiv.toFun_as_coe, Equiv.self_comp_symm, Function.id_comp]
map_rel' := fun n r {x} => by
simp only [Equiv.toFun_as_coe]
refine (f.map_rel' r (f.toEquiv.symm ∘ x)).symm.trans ?_
rw [← Function.comp.assoc, Equiv.toFun_as_coe, Equiv.self_comp_symm, Function.id_comp] }
#align first_order.language.equiv.symm FirstOrder.Language.Equiv.symm
instance hasCoeToFun : CoeFun (M ≃[L] N) fun _ => M → N :=
DFunLike.hasCoeToFun
#align first_order.language.equiv.has_coe_to_fun FirstOrder.Language.Equiv.hasCoeToFun
@[simp]
theorem symm_symm (f : M ≃[L] N) :
f.symm.symm = f :=
rfl
@[simp]
theorem apply_symm_apply (f : M ≃[L] N) (a : N) : f (f.symm a) = a :=
f.toEquiv.apply_symm_apply a
#align first_order.language.equiv.apply_symm_apply FirstOrder.Language.Equiv.apply_symm_apply
@[simp]
theorem symm_apply_apply (f : M ≃[L] N) (a : M) : f.symm (f a) = a :=
f.toEquiv.symm_apply_apply a
#align first_order.language.equiv.symm_apply_apply FirstOrder.Language.Equiv.symm_apply_apply
@[simp]
theorem map_fun (φ : M ≃[L] N) {n : ℕ} (f : L.Functions n) (x : Fin n → M) :
φ (funMap f x) = funMap f (φ ∘ x) :=
HomClass.map_fun φ f x
#align first_order.language.equiv.map_fun FirstOrder.Language.Equiv.map_fun
@[simp]
theorem map_constants (φ : M ≃[L] N) (c : L.Constants) : φ c = c :=
HomClass.map_constants φ c
#align first_order.language.equiv.map_constants FirstOrder.Language.Equiv.map_constants
@[simp]
theorem map_rel (φ : M ≃[L] N) {n : ℕ} (r : L.Relations n) (x : Fin n → M) :
RelMap r (φ ∘ x) ↔ RelMap r x :=
StrongHomClass.map_rel φ r x
#align first_order.language.equiv.map_rel FirstOrder.Language.Equiv.map_rel
def toEmbedding : (M ≃[L] N) → M ↪[L] N :=
StrongHomClass.toEmbedding
#align first_order.language.equiv.to_embedding FirstOrder.Language.Equiv.toEmbedding
def toHom : (M ≃[L] N) → M →[L] N :=
HomClass.toHom
#align first_order.language.equiv.to_hom FirstOrder.Language.Equiv.toHom
@[simp]
theorem toEmbedding_toHom (f : M ≃[L] N) : f.toEmbedding.toHom = f.toHom :=
rfl
#align first_order.language.equiv.to_embedding_to_hom FirstOrder.Language.Equiv.toEmbedding_toHom
@[simp]
theorem coe_toHom {f : M ≃[L] N} : (f.toHom : M → N) = (f : M → N) :=
rfl
#align first_order.language.equiv.coe_to_hom FirstOrder.Language.Equiv.coe_toHom
@[simp]
theorem coe_toEmbedding (f : M ≃[L] N) : (f.toEmbedding : M → N) = (f : M → N) :=
rfl
#align first_order.language.equiv.coe_to_embedding FirstOrder.Language.Equiv.coe_toEmbedding
theorem injective_toEmbedding : Function.Injective (toEmbedding : (M ≃[L] N) → M ↪[L] N) := by
intro _ _ h; apply DFunLike.coe_injective; exact congr_arg (DFunLike.coe ∘ Embedding.toHom) h
theorem coe_injective : @Function.Injective (M ≃[L] N) (M → N) (↑) :=
DFunLike.coe_injective
#align first_order.language.equiv.coe_injective FirstOrder.Language.Equiv.coe_injective
@[ext]
theorem ext ⦃f g : M ≃[L] N⦄ (h : ∀ x, f x = g x) : f = g :=
coe_injective (funext h)
#align first_order.language.equiv.ext FirstOrder.Language.Equiv.ext
theorem ext_iff {f g : M ≃[L] N} : f = g ↔ ∀ x, f x = g x :=
⟨fun h _ => h ▸ rfl, fun h => ext h⟩
#align first_order.language.equiv.ext_iff FirstOrder.Language.Equiv.ext_iff
theorem bijective (f : M ≃[L] N) : Function.Bijective f :=
EquivLike.bijective f
#align first_order.language.equiv.bijective FirstOrder.Language.Equiv.bijective
theorem injective (f : M ≃[L] N) : Function.Injective f :=
EquivLike.injective f
#align first_order.language.equiv.injective FirstOrder.Language.Equiv.injective
theorem surjective (f : M ≃[L] N) : Function.Surjective f :=
EquivLike.surjective f
#align first_order.language.equiv.surjective FirstOrder.Language.Equiv.surjective
variable (L) (M)
@[refl]
def refl : M ≃[L] M where toEquiv := _root_.Equiv.refl M
#align first_order.language.equiv.refl FirstOrder.Language.Equiv.refl
variable {L} {M}
instance : Inhabited (M ≃[L] M) :=
⟨refl L M⟩
@[simp]
theorem refl_apply (x : M) : refl L M x = x := by simp [refl]; rfl
#align first_order.language.equiv.refl_apply FirstOrder.Language.Equiv.refl_apply
@[trans]
def comp (hnp : N ≃[L] P) (hmn : M ≃[L] N) : M ≃[L] P :=
{ hmn.toEquiv.trans hnp.toEquiv with
toFun := hnp ∘ hmn
-- Porting note: should be done by autoparam?
map_fun' := by intros; simp only [Function.comp_apply, map_fun]; trivial
-- Porting note: should be done by autoparam?
map_rel' := by intros; rw [Function.comp.assoc, map_rel, map_rel] }
#align first_order.language.equiv.comp FirstOrder.Language.Equiv.comp
@[simp]
theorem comp_apply (g : N ≃[L] P) (f : M ≃[L] N) (x : M) : g.comp f x = g (f x) :=
rfl
#align first_order.language.equiv.comp_apply FirstOrder.Language.Equiv.comp_apply
@[simp]
theorem comp_refl (g : M ≃[L] N) : g.comp (refl L M) = g :=
rfl
@[simp]
theorem refl_comp (g : M ≃[L] N) : (refl L N).comp g = g :=
rfl
@[simp]
theorem refl_toEmbedding : (refl L M).toEmbedding = Embedding.refl L M :=
rfl
@[simp]
theorem refl_toHom : (refl L M).toHom = Hom.id L M :=
rfl
theorem comp_assoc (f : M ≃[L] N) (g : N ≃[L] P) (h : P ≃[L] Q) :
(h.comp g).comp f = h.comp (g.comp f) :=
rfl
#align first_order.language.equiv.comp_assoc FirstOrder.Language.Equiv.comp_assoc
theorem injective_comp (h : N ≃[L] P) :
Function.Injective (h.comp : (M ≃[L] N) → (M ≃[L] P)) := by
intro f g hfg
ext x; exact h.injective (congr_fun (congr_arg DFunLike.coe hfg) x)
@[simp]
theorem comp_toHom (hnp : N ≃[L] P) (hmn : M ≃[L] N) :
(hnp.comp hmn).toHom = hnp.toHom.comp hmn.toHom :=
rfl
@[simp]
theorem comp_toEmbedding (hnp : N ≃[L] P) (hmn : M ≃[L] N) :
(hnp.comp hmn).toEmbedding = hnp.toEmbedding.comp hmn.toEmbedding :=
rfl
@[simp]
theorem self_comp_symm (f : M ≃[L] N) : f.comp f.symm = refl L N := by
ext; rw [comp_apply, apply_symm_apply, refl_apply]
@[simp]
theorem symm_comp_self (f : M ≃[L] N) : f.symm.comp f = refl L M := by
ext; rw [comp_apply, symm_apply_apply, refl_apply]
@[simp]
theorem symm_comp_self_toEmbedding (f : M ≃[L] N) :
f.symm.toEmbedding.comp f.toEmbedding = Embedding.refl L M := by
rw [← comp_toEmbedding, symm_comp_self, refl_toEmbedding]
@[simp]
| Mathlib/ModelTheory/Basic.lean | 989 | 991 | theorem self_comp_symm_toEmbedding (f : M ≃[L] N) :
f.toEmbedding.comp f.symm.toEmbedding = Embedding.refl L N := by |
rw [← comp_toEmbedding, self_comp_symm, refl_toEmbedding]
|
import Mathlib.Algebra.Algebra.Subalgebra.Basic
import Mathlib.Topology.Algebra.Module.Basic
import Mathlib.RingTheory.Adjoin.Basic
#align_import topology.algebra.algebra from "leanprover-community/mathlib"@"43afc5ad87891456c57b5a183e3e617d67c2b1db"
open scoped Classical
open Set TopologicalSpace Algebra
open scoped Classical
universe u v w
section TopologicalAlgebra
variable (R : Type*) (A : Type u)
variable [CommSemiring R] [Semiring A] [Algebra R A]
variable [TopologicalSpace R] [TopologicalSpace A]
@[continuity, fun_prop]
| Mathlib/Topology/Algebra/Algebra.lean | 42 | 44 | theorem continuous_algebraMap [ContinuousSMul R A] : Continuous (algebraMap R A) := by |
rw [algebraMap_eq_smul_one']
exact continuous_id.smul continuous_const
|
import Mathlib.Algebra.Polynomial.AlgebraMap
import Mathlib.Algebra.Polynomial.Degree.Lemmas
import Mathlib.Algebra.Polynomial.HasseDeriv
#align_import data.polynomial.taylor from "leanprover-community/mathlib"@"70fd9563a21e7b963887c9360bd29b2393e6225a"
noncomputable section
namespace Polynomial
open Polynomial
variable {R : Type*} [Semiring R] (r : R) (f : R[X])
def taylor (r : R) : R[X] →ₗ[R] R[X] where
toFun f := f.comp (X + C r)
map_add' f g := add_comp
map_smul' c f := by simp only [smul_eq_C_mul, C_mul_comp, RingHom.id_apply]
#align polynomial.taylor Polynomial.taylor
theorem taylor_apply : taylor r f = f.comp (X + C r) :=
rfl
#align polynomial.taylor_apply Polynomial.taylor_apply
@[simp]
theorem taylor_X : taylor r X = X + C r := by simp only [taylor_apply, X_comp]
set_option linter.uppercaseLean3 false in
#align polynomial.taylor_X Polynomial.taylor_X
@[simp]
theorem taylor_C (x : R) : taylor r (C x) = C x := by simp only [taylor_apply, C_comp]
set_option linter.uppercaseLean3 false in
#align polynomial.taylor_C Polynomial.taylor_C
@[simp]
theorem taylor_zero' : taylor (0 : R) = LinearMap.id := by
ext
simp only [taylor_apply, add_zero, comp_X, _root_.map_zero, LinearMap.id_comp,
Function.comp_apply, LinearMap.coe_comp]
#align polynomial.taylor_zero' Polynomial.taylor_zero'
theorem taylor_zero (f : R[X]) : taylor 0 f = f := by rw [taylor_zero', LinearMap.id_apply]
#align polynomial.taylor_zero Polynomial.taylor_zero
@[simp]
theorem taylor_one : taylor r (1 : R[X]) = C 1 := by rw [← C_1, taylor_C]
#align polynomial.taylor_one Polynomial.taylor_one
@[simp]
theorem taylor_monomial (i : ℕ) (k : R) : taylor r (monomial i k) = C k * (X + C r) ^ i := by
simp [taylor_apply]
#align polynomial.taylor_monomial Polynomial.taylor_monomial
theorem taylor_coeff (n : ℕ) : (taylor r f).coeff n = (hasseDeriv n f).eval r :=
show (lcoeff R n).comp (taylor r) f = (leval r).comp (hasseDeriv n) f by
congr 1; clear! f; ext i
simp only [leval_apply, mul_one, one_mul, eval_monomial, LinearMap.comp_apply, coeff_C_mul,
hasseDeriv_monomial, taylor_apply, monomial_comp, C_1, (commute_X (C r)).add_pow i,
map_sum]
simp only [lcoeff_apply, ← C_eq_natCast, mul_assoc, ← C_pow, ← C_mul, coeff_mul_C,
(Nat.cast_commute _ _).eq, coeff_X_pow, boole_mul, Finset.sum_ite_eq, Finset.mem_range]
split_ifs with h; · rfl
push_neg at h; rw [Nat.choose_eq_zero_of_lt h, Nat.cast_zero, mul_zero]
#align polynomial.taylor_coeff Polynomial.taylor_coeff
@[simp]
theorem taylor_coeff_zero : (taylor r f).coeff 0 = f.eval r := by
rw [taylor_coeff, hasseDeriv_zero, LinearMap.id_apply]
#align polynomial.taylor_coeff_zero Polynomial.taylor_coeff_zero
@[simp]
theorem taylor_coeff_one : (taylor r f).coeff 1 = f.derivative.eval r := by
rw [taylor_coeff, hasseDeriv_one]
#align polynomial.taylor_coeff_one Polynomial.taylor_coeff_one
@[simp]
theorem natDegree_taylor (p : R[X]) (r : R) : natDegree (taylor r p) = natDegree p := by
refine map_natDegree_eq_natDegree _ ?_
nontriviality R
intro n c c0
simp [taylor_monomial, natDegree_C_mul_eq_of_mul_ne_zero, natDegree_pow_X_add_C, c0]
#align polynomial.nat_degree_taylor Polynomial.natDegree_taylor
@[simp]
theorem taylor_mul {R} [CommSemiring R] (r : R) (p q : R[X]) :
taylor r (p * q) = taylor r p * taylor r q := by simp only [taylor_apply, mul_comp]
#align polynomial.taylor_mul Polynomial.taylor_mul
@[simps!]
def taylorAlgHom {R} [CommSemiring R] (r : R) : R[X] →ₐ[R] R[X] :=
AlgHom.ofLinearMap (taylor r) (taylor_one r) (taylor_mul r)
#align polynomial.taylor_alg_hom Polynomial.taylorAlgHom
| Mathlib/Algebra/Polynomial/Taylor.lean | 116 | 118 | theorem taylor_taylor {R} [CommSemiring R] (f : R[X]) (r s : R) :
taylor r (taylor s f) = taylor (r + s) f := by |
simp only [taylor_apply, comp_assoc, map_add, add_comp, X_comp, C_comp, C_add, add_assoc]
|
import Mathlib.Algebra.Order.Group.Basic
import Mathlib.Algebra.Order.Ring.Basic
import Mathlib.RingTheory.Ideal.Maps
import Mathlib.Tactic.TFAE
#align_import ring_theory.valuation.basic from "leanprover-community/mathlib"@"2196ab363eb097c008d4497125e0dde23fb36db2"
open scoped Classical
open Function Ideal
noncomputable section
variable {K F R : Type*} [DivisionRing K]
section
variable (F R) (Γ₀ : Type*) [LinearOrderedCommMonoidWithZero Γ₀] [Ring R]
--porting note (#5171): removed @[nolint has_nonempty_instance]
structure Valuation extends R →*₀ Γ₀ where
map_add_le_max' : ∀ x y, toFun (x + y) ≤ max (toFun x) (toFun y)
#align valuation Valuation
class ValuationClass (F) (R Γ₀ : outParam Type*) [LinearOrderedCommMonoidWithZero Γ₀] [Ring R]
[FunLike F R Γ₀]
extends MonoidWithZeroHomClass F R Γ₀ : Prop where
map_add_le_max (f : F) (x y : R) : f (x + y) ≤ max (f x) (f y)
#align valuation_class ValuationClass
export ValuationClass (map_add_le_max)
instance [FunLike F R Γ₀] [ValuationClass F R Γ₀] : CoeTC F (Valuation R Γ₀) :=
⟨fun f =>
{ toFun := f
map_one' := map_one f
map_zero' := map_zero f
map_mul' := map_mul f
map_add_le_max' := map_add_le_max f }⟩
end
namespace Valuation
variable {Γ₀ : Type*}
variable {Γ'₀ : Type*}
variable {Γ''₀ : Type*} [LinearOrderedCommMonoidWithZero Γ''₀]
section Basic
variable [Ring R]
section Monoid
variable [LinearOrderedCommMonoidWithZero Γ₀] [LinearOrderedCommMonoidWithZero Γ'₀]
instance : FunLike (Valuation R Γ₀) R Γ₀ where
coe f := f.toFun
coe_injective' f g h := by
obtain ⟨⟨⟨_,_⟩, _⟩, _⟩ := f
congr
instance : ValuationClass (Valuation R Γ₀) R Γ₀ where
map_mul f := f.map_mul'
map_one f := f.map_one'
map_zero f := f.map_zero'
map_add_le_max f := f.map_add_le_max'
@[simp]
theorem coe_mk (f : R →*₀ Γ₀) (h) : ⇑(Valuation.mk f h) = f := rfl
theorem toFun_eq_coe (v : Valuation R Γ₀) : v.toFun = v := rfl
#align valuation.to_fun_eq_coe Valuation.toFun_eq_coe
@[simp] -- Porting note: requested by simpNF as toFun_eq_coe LHS simplifies
theorem toMonoidWithZeroHom_coe_eq_coe (v : Valuation R Γ₀) :
(v.toMonoidWithZeroHom : R → Γ₀) = v := rfl
@[ext]
theorem ext {v₁ v₂ : Valuation R Γ₀} (h : ∀ r, v₁ r = v₂ r) : v₁ = v₂ :=
DFunLike.ext _ _ h
#align valuation.ext Valuation.ext
variable (v : Valuation R Γ₀) {x y z : R}
@[simp, norm_cast]
theorem coe_coe : ⇑(v : R →*₀ Γ₀) = v := rfl
#align valuation.coe_coe Valuation.coe_coe
-- @[simp] Porting note (#10618): simp can prove this
theorem map_zero : v 0 = 0 :=
v.map_zero'
#align valuation.map_zero Valuation.map_zero
-- @[simp] Porting note (#10618): simp can prove this
theorem map_one : v 1 = 1 :=
v.map_one'
#align valuation.map_one Valuation.map_one
-- @[simp] Porting note (#10618): simp can prove this
theorem map_mul : ∀ x y, v (x * y) = v x * v y :=
v.map_mul'
#align valuation.map_mul Valuation.map_mul
-- Porting note: LHS side simplified so created map_add'
theorem map_add : ∀ x y, v (x + y) ≤ max (v x) (v y) :=
v.map_add_le_max'
#align valuation.map_add Valuation.map_add
@[simp]
| Mathlib/RingTheory/Valuation/Basic.lean | 174 | 177 | theorem map_add' : ∀ x y, v (x + y) ≤ v x ∨ v (x + y) ≤ v y := by |
intro x y
rw [← le_max_iff, ← ge_iff_le]
apply map_add
|
import Mathlib.Algebra.BigOperators.Group.Finset
import Mathlib.Algebra.Order.Field.Defs
import Mathlib.Algebra.Order.Group.Instances
import Mathlib.Algebra.Order.Group.MinMax
import Mathlib.Algebra.Order.Ring.Basic
import Mathlib.Data.Finset.Preimage
import Mathlib.Order.Interval.Set.Disjoint
import Mathlib.Order.Interval.Set.OrderIso
import Mathlib.Order.ConditionallyCompleteLattice.Basic
import Mathlib.Order.Filter.Bases
#align_import order.filter.at_top_bot from "leanprover-community/mathlib"@"1f0096e6caa61e9c849ec2adbd227e960e9dff58"
set_option autoImplicit true
variable {ι ι' α β γ : Type*}
open Set
namespace Filter
theorem inf_map_atTop_neBot_iff [SemilatticeSup α] [Nonempty α] {F : Filter β} {u : α → β} :
NeBot (F ⊓ map u atTop) ↔ ∀ U ∈ F, ∀ N, ∃ n ≥ N, u n ∈ U := by
simp_rw [inf_neBot_iff_frequently_left, frequently_map, frequently_atTop]; rfl
#align filter.inf_map_at_top_ne_bot_iff Filter.inf_map_atTop_neBot_iff
theorem inf_map_atBot_neBot_iff [SemilatticeInf α] [Nonempty α] {F : Filter β} {u : α → β} :
NeBot (F ⊓ map u atBot) ↔ ∀ U ∈ F, ∀ N, ∃ n ≤ N, u n ∈ U :=
@inf_map_atTop_neBot_iff αᵒᵈ _ _ _ _ _
#align filter.inf_map_at_bot_ne_bot_iff Filter.inf_map_atBot_neBot_iff
theorem extraction_of_frequently_atTop' {P : ℕ → Prop} (h : ∀ N, ∃ n > N, P n) :
∃ φ : ℕ → ℕ, StrictMono φ ∧ ∀ n, P (φ n) := by
choose u hu hu' using h
refine ⟨fun n => u^[n + 1] 0, strictMono_nat_of_lt_succ fun n => ?_, fun n => ?_⟩
· exact Trans.trans (hu _) (Function.iterate_succ_apply' _ _ _).symm
· simpa only [Function.iterate_succ_apply'] using hu' _
#align filter.extraction_of_frequently_at_top' Filter.extraction_of_frequently_atTop'
theorem extraction_of_frequently_atTop {P : ℕ → Prop} (h : ∃ᶠ n in atTop, P n) :
∃ φ : ℕ → ℕ, StrictMono φ ∧ ∀ n, P (φ n) := by
rw [frequently_atTop'] at h
exact extraction_of_frequently_atTop' h
#align filter.extraction_of_frequently_at_top Filter.extraction_of_frequently_atTop
theorem extraction_of_eventually_atTop {P : ℕ → Prop} (h : ∀ᶠ n in atTop, P n) :
∃ φ : ℕ → ℕ, StrictMono φ ∧ ∀ n, P (φ n) :=
extraction_of_frequently_atTop h.frequently
#align filter.extraction_of_eventually_at_top Filter.extraction_of_eventually_atTop
theorem extraction_forall_of_frequently {P : ℕ → ℕ → Prop} (h : ∀ n, ∃ᶠ k in atTop, P n k) :
∃ φ : ℕ → ℕ, StrictMono φ ∧ ∀ n, P n (φ n) := by
simp only [frequently_atTop'] at h
choose u hu hu' using h
use (fun n => Nat.recOn n (u 0 0) fun n v => u (n + 1) v : ℕ → ℕ)
constructor
· apply strictMono_nat_of_lt_succ
intro n
apply hu
· intro n
cases n <;> simp [hu']
#align filter.extraction_forall_of_frequently Filter.extraction_forall_of_frequently
theorem extraction_forall_of_eventually {P : ℕ → ℕ → Prop} (h : ∀ n, ∀ᶠ k in atTop, P n k) :
∃ φ : ℕ → ℕ, StrictMono φ ∧ ∀ n, P n (φ n) :=
extraction_forall_of_frequently fun n => (h n).frequently
#align filter.extraction_forall_of_eventually Filter.extraction_forall_of_eventually
theorem extraction_forall_of_eventually' {P : ℕ → ℕ → Prop} (h : ∀ n, ∃ N, ∀ k ≥ N, P n k) :
∃ φ : ℕ → ℕ, StrictMono φ ∧ ∀ n, P n (φ n) :=
extraction_forall_of_eventually (by simp [eventually_atTop, h])
#align filter.extraction_forall_of_eventually' Filter.extraction_forall_of_eventually'
theorem Eventually.atTop_of_arithmetic {p : ℕ → Prop} {n : ℕ} (hn : n ≠ 0)
(hp : ∀ k < n, ∀ᶠ a in atTop, p (n * a + k)) : ∀ᶠ a in atTop, p a := by
simp only [eventually_atTop] at hp ⊢
choose! N hN using hp
refine ⟨(Finset.range n).sup (n * N ·), fun b hb => ?_⟩
rw [← Nat.div_add_mod b n]
have hlt := Nat.mod_lt b hn.bot_lt
refine hN _ hlt _ ?_
rw [ge_iff_le, Nat.le_div_iff_mul_le hn.bot_lt, mul_comm]
exact (Finset.le_sup (f := (n * N ·)) (Finset.mem_range.2 hlt)).trans hb
theorem exists_le_of_tendsto_atTop [SemilatticeSup α] [Preorder β] {u : α → β}
(h : Tendsto u atTop atTop) (a : α) (b : β) : ∃ a' ≥ a, b ≤ u a' := by
have : Nonempty α := ⟨a⟩
have : ∀ᶠ x in atTop, a ≤ x ∧ b ≤ u x :=
(eventually_ge_atTop a).and (h.eventually <| eventually_ge_atTop b)
exact this.exists
#align filter.exists_le_of_tendsto_at_top Filter.exists_le_of_tendsto_atTop
-- @[nolint ge_or_gt] -- Porting note: restore attribute
theorem exists_le_of_tendsto_atBot [SemilatticeSup α] [Preorder β] {u : α → β}
(h : Tendsto u atTop atBot) : ∀ a b, ∃ a' ≥ a, u a' ≤ b :=
@exists_le_of_tendsto_atTop _ βᵒᵈ _ _ _ h
#align filter.exists_le_of_tendsto_at_bot Filter.exists_le_of_tendsto_atBot
theorem exists_lt_of_tendsto_atTop [SemilatticeSup α] [Preorder β] [NoMaxOrder β] {u : α → β}
(h : Tendsto u atTop atTop) (a : α) (b : β) : ∃ a' ≥ a, b < u a' := by
cases' exists_gt b with b' hb'
rcases exists_le_of_tendsto_atTop h a b' with ⟨a', ha', ha''⟩
exact ⟨a', ha', lt_of_lt_of_le hb' ha''⟩
#align filter.exists_lt_of_tendsto_at_top Filter.exists_lt_of_tendsto_atTop
-- @[nolint ge_or_gt] -- Porting note: restore attribute
theorem exists_lt_of_tendsto_atBot [SemilatticeSup α] [Preorder β] [NoMinOrder β] {u : α → β}
(h : Tendsto u atTop atBot) : ∀ a b, ∃ a' ≥ a, u a' < b :=
@exists_lt_of_tendsto_atTop _ βᵒᵈ _ _ _ _ h
#align filter.exists_lt_of_tendsto_at_bot Filter.exists_lt_of_tendsto_atBot
theorem high_scores [LinearOrder β] [NoMaxOrder β] {u : ℕ → β} (hu : Tendsto u atTop atTop) :
∀ N, ∃ n ≥ N, ∀ k < n, u k < u n := by
intro N
obtain ⟨k : ℕ, - : k ≤ N, hku : ∀ l ≤ N, u l ≤ u k⟩ : ∃ k ≤ N, ∀ l ≤ N, u l ≤ u k :=
exists_max_image _ u (finite_le_nat N) ⟨N, le_refl N⟩
have ex : ∃ n ≥ N, u k < u n := exists_lt_of_tendsto_atTop hu _ _
obtain ⟨n : ℕ, hnN : n ≥ N, hnk : u k < u n, hn_min : ∀ m, m < n → N ≤ m → u m ≤ u k⟩ :
∃ n ≥ N, u k < u n ∧ ∀ m, m < n → N ≤ m → u m ≤ u k := by
rcases Nat.findX ex with ⟨n, ⟨hnN, hnk⟩, hn_min⟩
push_neg at hn_min
exact ⟨n, hnN, hnk, hn_min⟩
use n, hnN
rintro (l : ℕ) (hl : l < n)
have hlk : u l ≤ u k := by
cases' (le_total l N : l ≤ N ∨ N ≤ l) with H H
· exact hku l H
· exact hn_min l hl H
calc
u l ≤ u k := hlk
_ < u n := hnk
#align filter.high_scores Filter.high_scores
-- see Note [nolint_ge]
-- @[nolint ge_or_gt] Porting note: restore attribute
theorem low_scores [LinearOrder β] [NoMinOrder β] {u : ℕ → β} (hu : Tendsto u atTop atBot) :
∀ N, ∃ n ≥ N, ∀ k < n, u n < u k :=
@high_scores βᵒᵈ _ _ _ hu
#align filter.low_scores Filter.low_scores
theorem frequently_high_scores [LinearOrder β] [NoMaxOrder β] {u : ℕ → β}
(hu : Tendsto u atTop atTop) : ∃ᶠ n in atTop, ∀ k < n, u k < u n := by
simpa [frequently_atTop] using high_scores hu
#align filter.frequently_high_scores Filter.frequently_high_scores
theorem frequently_low_scores [LinearOrder β] [NoMinOrder β] {u : ℕ → β}
(hu : Tendsto u atTop atBot) : ∃ᶠ n in atTop, ∀ k < n, u n < u k :=
@frequently_high_scores βᵒᵈ _ _ _ hu
#align filter.frequently_low_scores Filter.frequently_low_scores
theorem strictMono_subseq_of_tendsto_atTop {β : Type*} [LinearOrder β] [NoMaxOrder β] {u : ℕ → β}
(hu : Tendsto u atTop atTop) : ∃ φ : ℕ → ℕ, StrictMono φ ∧ StrictMono (u ∘ φ) :=
let ⟨φ, h, h'⟩ := extraction_of_frequently_atTop (frequently_high_scores hu)
⟨φ, h, fun _ m hnm => h' m _ (h hnm)⟩
#align filter.strict_mono_subseq_of_tendsto_at_top Filter.strictMono_subseq_of_tendsto_atTop
theorem strictMono_subseq_of_id_le {u : ℕ → ℕ} (hu : ∀ n, n ≤ u n) :
∃ φ : ℕ → ℕ, StrictMono φ ∧ StrictMono (u ∘ φ) :=
strictMono_subseq_of_tendsto_atTop (tendsto_atTop_mono hu tendsto_id)
#align filter.strict_mono_subseq_of_id_le Filter.strictMono_subseq_of_id_le
theorem _root_.StrictMono.tendsto_atTop {φ : ℕ → ℕ} (h : StrictMono φ) : Tendsto φ atTop atTop :=
tendsto_atTop_mono h.id_le tendsto_id
#align strict_mono.tendsto_at_top StrictMono.tendsto_atTop
theorem zero_pow_eventuallyEq [MonoidWithZero α] :
(fun n : ℕ => (0 : α) ^ n) =ᶠ[atTop] fun _ => 0 :=
eventually_atTop.2 ⟨1, fun _n hn ↦ zero_pow $ Nat.one_le_iff_ne_zero.1 hn⟩
#align filter.zero_pow_eventually_eq Filter.zero_pow_eventuallyEq
theorem not_tendsto_pow_atTop_atBot [LinearOrderedRing α] :
∀ {n : ℕ}, ¬Tendsto (fun x : α => x ^ n) atTop atBot
| 0 => by simp [not_tendsto_const_atBot]
| n + 1 => (tendsto_pow_atTop n.succ_ne_zero).not_tendsto disjoint_atTop_atBot
#align filter.not_tendsto_pow_at_top_at_bot Filter.not_tendsto_pow_atTop_atBot
open Filter
theorem tendsto_atTop' [Nonempty α] [SemilatticeSup α] {f : α → β} {l : Filter β} :
Tendsto f atTop l ↔ ∀ s ∈ l, ∃ a, ∀ b ≥ a, f b ∈ s := by
simp only [tendsto_def, mem_atTop_sets, mem_preimage]
#align filter.tendsto_at_top' Filter.tendsto_atTop'
theorem tendsto_atBot' [Nonempty α] [SemilatticeInf α] {f : α → β} {l : Filter β} :
Tendsto f atBot l ↔ ∀ s ∈ l, ∃ a, ∀ b ≤ a, f b ∈ s :=
@tendsto_atTop' αᵒᵈ _ _ _ _ _
#align filter.tendsto_at_bot' Filter.tendsto_atBot'
theorem tendsto_atTop_principal [Nonempty β] [SemilatticeSup β] {f : β → α} {s : Set α} :
Tendsto f atTop (𝓟 s) ↔ ∃ N, ∀ n ≥ N, f n ∈ s := by
simp_rw [tendsto_iff_comap, comap_principal, le_principal_iff, mem_atTop_sets, mem_preimage]
#align filter.tendsto_at_top_principal Filter.tendsto_atTop_principal
theorem tendsto_atBot_principal [Nonempty β] [SemilatticeInf β] {f : β → α} {s : Set α} :
Tendsto f atBot (𝓟 s) ↔ ∃ N, ∀ n ≤ N, f n ∈ s :=
@tendsto_atTop_principal _ βᵒᵈ _ _ _ _
#align filter.tendsto_at_bot_principal Filter.tendsto_atBot_principal
theorem tendsto_atTop_atTop [Nonempty α] [SemilatticeSup α] [Preorder β] {f : α → β} :
Tendsto f atTop atTop ↔ ∀ b : β, ∃ i : α, ∀ a : α, i ≤ a → b ≤ f a :=
Iff.trans tendsto_iInf <| forall_congr' fun _ => tendsto_atTop_principal
#align filter.tendsto_at_top_at_top Filter.tendsto_atTop_atTop
theorem tendsto_atTop_atBot [Nonempty α] [SemilatticeSup α] [Preorder β] {f : α → β} :
Tendsto f atTop atBot ↔ ∀ b : β, ∃ i : α, ∀ a : α, i ≤ a → f a ≤ b :=
@tendsto_atTop_atTop α βᵒᵈ _ _ _ f
#align filter.tendsto_at_top_at_bot Filter.tendsto_atTop_atBot
theorem tendsto_atBot_atTop [Nonempty α] [SemilatticeInf α] [Preorder β] {f : α → β} :
Tendsto f atBot atTop ↔ ∀ b : β, ∃ i : α, ∀ a : α, a ≤ i → b ≤ f a :=
@tendsto_atTop_atTop αᵒᵈ β _ _ _ f
#align filter.tendsto_at_bot_at_top Filter.tendsto_atBot_atTop
theorem tendsto_atBot_atBot [Nonempty α] [SemilatticeInf α] [Preorder β] {f : α → β} :
Tendsto f atBot atBot ↔ ∀ b : β, ∃ i : α, ∀ a : α, a ≤ i → f a ≤ b :=
@tendsto_atTop_atTop αᵒᵈ βᵒᵈ _ _ _ f
#align filter.tendsto_at_bot_at_bot Filter.tendsto_atBot_atBot
theorem tendsto_atTop_atTop_of_monotone [Preorder α] [Preorder β] {f : α → β} (hf : Monotone f)
(h : ∀ b, ∃ a, b ≤ f a) : Tendsto f atTop atTop :=
tendsto_iInf.2 fun b =>
tendsto_principal.2 <|
let ⟨a, ha⟩ := h b
mem_of_superset (mem_atTop a) fun _a' ha' => le_trans ha (hf ha')
#align filter.tendsto_at_top_at_top_of_monotone Filter.tendsto_atTop_atTop_of_monotone
theorem tendsto_atTop_atBot_of_antitone [Preorder α] [Preorder β] {f : α → β} (hf : Antitone f)
(h : ∀ b, ∃ a, f a ≤ b) : Tendsto f atTop atBot :=
@tendsto_atTop_atTop_of_monotone _ βᵒᵈ _ _ _ hf h
theorem tendsto_atBot_atBot_of_monotone [Preorder α] [Preorder β] {f : α → β} (hf : Monotone f)
(h : ∀ b, ∃ a, f a ≤ b) : Tendsto f atBot atBot :=
tendsto_iInf.2 fun b => tendsto_principal.2 <|
let ⟨a, ha⟩ := h b; mem_of_superset (mem_atBot a) fun _a' ha' => le_trans (hf ha') ha
#align filter.tendsto_at_bot_at_bot_of_monotone Filter.tendsto_atBot_atBot_of_monotone
theorem tendsto_atBot_atTop_of_antitone [Preorder α] [Preorder β] {f : α → β} (hf : Antitone f)
(h : ∀ b, ∃ a, b ≤ f a) : Tendsto f atBot atTop :=
@tendsto_atBot_atBot_of_monotone _ βᵒᵈ _ _ _ hf h
theorem tendsto_atTop_atTop_iff_of_monotone [Nonempty α] [SemilatticeSup α] [Preorder β] {f : α → β}
(hf : Monotone f) : Tendsto f atTop atTop ↔ ∀ b : β, ∃ a : α, b ≤ f a :=
tendsto_atTop_atTop.trans <| forall_congr' fun _ => exists_congr fun a =>
⟨fun h => h a (le_refl a), fun h _a' ha' => le_trans h <| hf ha'⟩
#align filter.tendsto_at_top_at_top_iff_of_monotone Filter.tendsto_atTop_atTop_iff_of_monotone
theorem tendsto_atTop_atBot_iff_of_antitone [Nonempty α] [SemilatticeSup α] [Preorder β] {f : α → β}
(hf : Antitone f) : Tendsto f atTop atBot ↔ ∀ b : β, ∃ a : α, f a ≤ b :=
@tendsto_atTop_atTop_iff_of_monotone _ βᵒᵈ _ _ _ _ hf
theorem tendsto_atBot_atBot_iff_of_monotone [Nonempty α] [SemilatticeInf α] [Preorder β] {f : α → β}
(hf : Monotone f) : Tendsto f atBot atBot ↔ ∀ b : β, ∃ a : α, f a ≤ b :=
tendsto_atBot_atBot.trans <| forall_congr' fun _ => exists_congr fun a =>
⟨fun h => h a (le_refl a), fun h _a' ha' => le_trans (hf ha') h⟩
#align filter.tendsto_at_bot_at_bot_iff_of_monotone Filter.tendsto_atBot_atBot_iff_of_monotone
theorem tendsto_atBot_atTop_iff_of_antitone [Nonempty α] [SemilatticeInf α] [Preorder β] {f : α → β}
(hf : Antitone f) : Tendsto f atBot atTop ↔ ∀ b : β, ∃ a : α, b ≤ f a :=
@tendsto_atBot_atBot_iff_of_monotone _ βᵒᵈ _ _ _ _ hf
alias _root_.Monotone.tendsto_atTop_atTop := tendsto_atTop_atTop_of_monotone
#align monotone.tendsto_at_top_at_top Monotone.tendsto_atTop_atTop
alias _root_.Monotone.tendsto_atBot_atBot := tendsto_atBot_atBot_of_monotone
#align monotone.tendsto_at_bot_at_bot Monotone.tendsto_atBot_atBot
alias _root_.Monotone.tendsto_atTop_atTop_iff := tendsto_atTop_atTop_iff_of_monotone
#align monotone.tendsto_at_top_at_top_iff Monotone.tendsto_atTop_atTop_iff
alias _root_.Monotone.tendsto_atBot_atBot_iff := tendsto_atBot_atBot_iff_of_monotone
#align monotone.tendsto_at_bot_at_bot_iff Monotone.tendsto_atBot_atBot_iff
theorem comap_embedding_atTop [Preorder β] [Preorder γ] {e : β → γ}
(hm : ∀ b₁ b₂, e b₁ ≤ e b₂ ↔ b₁ ≤ b₂) (hu : ∀ c, ∃ b, c ≤ e b) : comap e atTop = atTop :=
le_antisymm
(le_iInf fun b =>
le_principal_iff.2 <| mem_comap.2 ⟨Ici (e b), mem_atTop _, fun _ => (hm _ _).1⟩)
(tendsto_atTop_atTop_of_monotone (fun _ _ => (hm _ _).2) hu).le_comap
#align filter.comap_embedding_at_top Filter.comap_embedding_atTop
theorem comap_embedding_atBot [Preorder β] [Preorder γ] {e : β → γ}
(hm : ∀ b₁ b₂, e b₁ ≤ e b₂ ↔ b₁ ≤ b₂) (hu : ∀ c, ∃ b, e b ≤ c) : comap e atBot = atBot :=
@comap_embedding_atTop βᵒᵈ γᵒᵈ _ _ e (Function.swap hm) hu
#align filter.comap_embedding_at_bot Filter.comap_embedding_atBot
theorem tendsto_atTop_embedding [Preorder β] [Preorder γ] {f : α → β} {e : β → γ} {l : Filter α}
(hm : ∀ b₁ b₂, e b₁ ≤ e b₂ ↔ b₁ ≤ b₂) (hu : ∀ c, ∃ b, c ≤ e b) :
Tendsto (e ∘ f) l atTop ↔ Tendsto f l atTop := by
rw [← comap_embedding_atTop hm hu, tendsto_comap_iff]
#align filter.tendsto_at_top_embedding Filter.tendsto_atTop_embedding
theorem tendsto_atBot_embedding [Preorder β] [Preorder γ] {f : α → β} {e : β → γ} {l : Filter α}
(hm : ∀ b₁ b₂, e b₁ ≤ e b₂ ↔ b₁ ≤ b₂) (hu : ∀ c, ∃ b, e b ≤ c) :
Tendsto (e ∘ f) l atBot ↔ Tendsto f l atBot :=
@tendsto_atTop_embedding α βᵒᵈ γᵒᵈ _ _ f e l (Function.swap hm) hu
#align filter.tendsto_at_bot_embedding Filter.tendsto_atBot_embedding
theorem tendsto_finset_range : Tendsto Finset.range atTop atTop :=
Finset.range_mono.tendsto_atTop_atTop Finset.exists_nat_subset_range
#align filter.tendsto_finset_range Filter.tendsto_finset_range
theorem atTop_finset_eq_iInf : (atTop : Filter (Finset α)) = ⨅ x : α, 𝓟 (Ici {x}) := by
refine le_antisymm (le_iInf fun i => le_principal_iff.2 <| mem_atTop ({i} : Finset α)) ?_
refine
le_iInf fun s =>
le_principal_iff.2 <| mem_iInf_of_iInter s.finite_toSet (fun i => mem_principal_self _) ?_
simp only [subset_def, mem_iInter, SetCoe.forall, mem_Ici, Finset.le_iff_subset,
Finset.mem_singleton, Finset.subset_iff, forall_eq]
exact fun t => id
#align filter.at_top_finset_eq_infi Filter.atTop_finset_eq_iInf
| Mathlib/Order/Filter/AtTopBot.lean | 1,512 | 1,517 | theorem tendsto_atTop_finset_of_monotone [Preorder β] {f : β → Finset α} (h : Monotone f)
(h' : ∀ x : α, ∃ n, x ∈ f n) : Tendsto f atTop atTop := by |
simp only [atTop_finset_eq_iInf, tendsto_iInf, tendsto_principal]
intro a
rcases h' a with ⟨b, hb⟩
exact (eventually_ge_atTop b).mono fun b' hb' => (Finset.singleton_subset_iff.2 hb).trans (h hb')
|
import Mathlib.Data.List.Forall2
#align_import data.list.zip from "leanprover-community/mathlib"@"134625f523e737f650a6ea7f0c82a6177e45e622"
-- Make sure we don't import algebra
assert_not_exists Monoid
universe u
open Nat
namespace List
variable {α : Type u} {β γ δ ε : Type*}
#align list.zip_with_cons_cons List.zipWith_cons_cons
#align list.zip_cons_cons List.zip_cons_cons
#align list.zip_with_nil_left List.zipWith_nil_left
#align list.zip_with_nil_right List.zipWith_nil_right
#align list.zip_with_eq_nil_iff List.zipWith_eq_nil_iff
#align list.zip_nil_left List.zip_nil_left
#align list.zip_nil_right List.zip_nil_right
@[simp]
theorem zip_swap : ∀ (l₁ : List α) (l₂ : List β), (zip l₁ l₂).map Prod.swap = zip l₂ l₁
| [], l₂ => zip_nil_right.symm
| l₁, [] => by rw [zip_nil_right]; rfl
| a :: l₁, b :: l₂ => by
simp only [zip_cons_cons, map_cons, zip_swap l₁ l₂, Prod.swap_prod_mk]
#align list.zip_swap List.zip_swap
#align list.length_zip_with List.length_zipWith
#align list.length_zip List.length_zip
theorem forall_zipWith {f : α → β → γ} {p : γ → Prop} :
∀ {l₁ : List α} {l₂ : List β}, length l₁ = length l₂ →
(Forall p (zipWith f l₁ l₂) ↔ Forall₂ (fun x y => p (f x y)) l₁ l₂)
| [], [], _ => by simp
| a :: l₁, b :: l₂, h => by
simp only [length_cons, succ_inj'] at h
simp [forall_zipWith h]
#align list.all₂_zip_with List.forall_zipWith
theorem lt_length_left_of_zipWith {f : α → β → γ} {i : ℕ} {l : List α} {l' : List β}
(h : i < (zipWith f l l').length) : i < l.length := by rw [length_zipWith] at h; omega
#align list.lt_length_left_of_zip_with List.lt_length_left_of_zipWith
theorem lt_length_right_of_zipWith {f : α → β → γ} {i : ℕ} {l : List α} {l' : List β}
(h : i < (zipWith f l l').length) : i < l'.length := by rw [length_zipWith] at h; omega
#align list.lt_length_right_of_zip_with List.lt_length_right_of_zipWith
theorem lt_length_left_of_zip {i : ℕ} {l : List α} {l' : List β} (h : i < (zip l l').length) :
i < l.length :=
lt_length_left_of_zipWith h
#align list.lt_length_left_of_zip List.lt_length_left_of_zip
theorem lt_length_right_of_zip {i : ℕ} {l : List α} {l' : List β} (h : i < (zip l l').length) :
i < l'.length :=
lt_length_right_of_zipWith h
#align list.lt_length_right_of_zip List.lt_length_right_of_zip
#align list.zip_append List.zip_append
#align list.zip_map List.zip_map
#align list.zip_map_left List.zip_map_left
#align list.zip_map_right List.zip_map_right
#align list.zip_with_map List.zipWith_map
#align list.zip_with_map_left List.zipWith_map_left
#align list.zip_with_map_right List.zipWith_map_right
#align list.zip_map' List.zip_map'
#align list.map_zip_with List.map_zipWith
theorem mem_zip {a b} : ∀ {l₁ : List α} {l₂ : List β}, (a, b) ∈ zip l₁ l₂ → a ∈ l₁ ∧ b ∈ l₂
| _ :: l₁, _ :: l₂, h => by
cases' h with _ _ _ h
· simp
· have := mem_zip h
exact ⟨Mem.tail _ this.1, Mem.tail _ this.2⟩
#align list.mem_zip List.mem_zip
#align list.map_fst_zip List.map_fst_zip
#align list.map_snd_zip List.map_snd_zip
#align list.unzip_nil List.unzip_nil
#align list.unzip_cons List.unzip_cons
theorem unzip_eq_map : ∀ l : List (α × β), unzip l = (l.map Prod.fst, l.map Prod.snd)
| [] => rfl
| (a, b) :: l => by simp only [unzip_cons, map_cons, unzip_eq_map l]
#align list.unzip_eq_map List.unzip_eq_map
theorem unzip_left (l : List (α × β)) : (unzip l).1 = l.map Prod.fst := by simp only [unzip_eq_map]
#align list.unzip_left List.unzip_left
theorem unzip_right (l : List (α × β)) : (unzip l).2 = l.map Prod.snd := by simp only [unzip_eq_map]
#align list.unzip_right List.unzip_right
theorem unzip_swap (l : List (α × β)) : unzip (l.map Prod.swap) = (unzip l).swap := by
simp only [unzip_eq_map, map_map]
rfl
#align list.unzip_swap List.unzip_swap
theorem zip_unzip : ∀ l : List (α × β), zip (unzip l).1 (unzip l).2 = l
| [] => rfl
| (a, b) :: l => by simp only [unzip_cons, zip_cons_cons, zip_unzip l]
#align list.zip_unzip List.zip_unzip
theorem unzip_zip_left :
∀ {l₁ : List α} {l₂ : List β}, length l₁ ≤ length l₂ → (unzip (zip l₁ l₂)).1 = l₁
| [], l₂, _ => rfl
| l₁, [], h => by rw [eq_nil_of_length_eq_zero (Nat.eq_zero_of_le_zero h)]; rfl
| a :: l₁, b :: l₂, h => by
simp only [zip_cons_cons, unzip_cons, unzip_zip_left (le_of_succ_le_succ h)]
#align list.unzip_zip_left List.unzip_zip_left
theorem unzip_zip_right {l₁ : List α} {l₂ : List β} (h : length l₂ ≤ length l₁) :
(unzip (zip l₁ l₂)).2 = l₂ := by rw [← zip_swap, unzip_swap]; exact unzip_zip_left h
#align list.unzip_zip_right List.unzip_zip_right
theorem unzip_zip {l₁ : List α} {l₂ : List β} (h : length l₁ = length l₂) :
unzip (zip l₁ l₂) = (l₁, l₂) := by
rw [← Prod.mk.eta (p := unzip (zip l₁ l₂)),
unzip_zip_left (le_of_eq h), unzip_zip_right (ge_of_eq h)]
#align list.unzip_zip List.unzip_zip
theorem zip_of_prod {l : List α} {l' : List β} {lp : List (α × β)} (hl : lp.map Prod.fst = l)
(hr : lp.map Prod.snd = l') : lp = l.zip l' := by
rw [← hl, ← hr, ← zip_unzip lp, ← unzip_left, ← unzip_right, zip_unzip, zip_unzip]
#align list.zip_of_prod List.zip_of_prod
theorem map_prod_left_eq_zip {l : List α} (f : α → β) :
(l.map fun x => (x, f x)) = l.zip (l.map f) := by
rw [← zip_map']
congr
exact map_id _
#align list.map_prod_left_eq_zip List.map_prod_left_eq_zip
theorem map_prod_right_eq_zip {l : List α} (f : α → β) :
(l.map fun x => (f x, x)) = (l.map f).zip l := by
rw [← zip_map']
congr
exact map_id _
#align list.map_prod_right_eq_zip List.map_prod_right_eq_zip
theorem zipWith_comm (f : α → β → γ) :
∀ (la : List α) (lb : List β), zipWith f la lb = zipWith (fun b a => f a b) lb la
| [], _ => List.zipWith_nil_right.symm
| _ :: _, [] => rfl
| _ :: as, _ :: bs => congr_arg _ (zipWith_comm f as bs)
#align list.zip_with_comm List.zipWith_comm
@[congr]
| Mathlib/Data/List/Zip.lean | 170 | 174 | theorem zipWith_congr (f g : α → β → γ) (la : List α) (lb : List β)
(h : List.Forall₂ (fun a b => f a b = g a b) la lb) : zipWith f la lb = zipWith g la lb := by |
induction' h with a b as bs hfg _ ih
· rfl
· exact congr_arg₂ _ hfg ih
|
import Mathlib.Algebra.Group.WithOne.Defs
import Mathlib.Algebra.GroupWithZero.InjSurj
import Mathlib.Algebra.GroupWithZero.Units.Equiv
import Mathlib.Algebra.GroupWithZero.WithZero
import Mathlib.Algebra.Order.Group.Units
import Mathlib.Algebra.Order.GroupWithZero.Synonym
import Mathlib.Algebra.Order.Monoid.Basic
import Mathlib.Algebra.Order.Monoid.OrderDual
import Mathlib.Algebra.Order.Monoid.TypeTags
import Mathlib.Algebra.Order.ZeroLEOne
#align_import algebra.order.monoid.with_zero.defs from "leanprover-community/mathlib"@"4dc134b97a3de65ef2ed881f3513d56260971562"
#align_import algebra.order.monoid.with_zero.basic from "leanprover-community/mathlib"@"dad7ecf9a1feae63e6e49f07619b7087403fb8d4"
#align_import algebra.order.with_zero from "leanprover-community/mathlib"@"655994e298904d7e5bbd1e18c95defd7b543eb94"
variable {α : Type*}
class LinearOrderedCommMonoidWithZero (α : Type*) extends LinearOrderedCommMonoid α,
CommMonoidWithZero α where
zero_le_one : (0 : α) ≤ 1
#align linear_ordered_comm_monoid_with_zero LinearOrderedCommMonoidWithZero
class LinearOrderedCommGroupWithZero (α : Type*) extends LinearOrderedCommMonoidWithZero α,
CommGroupWithZero α
#align linear_ordered_comm_group_with_zero LinearOrderedCommGroupWithZero
instance (priority := 100) LinearOrderedCommMonoidWithZero.toZeroLeOneClass
[LinearOrderedCommMonoidWithZero α] : ZeroLEOneClass α :=
{ ‹LinearOrderedCommMonoidWithZero α› with }
#align linear_ordered_comm_monoid_with_zero.to_zero_le_one_class LinearOrderedCommMonoidWithZero.toZeroLeOneClass
instance (priority := 100) canonicallyOrderedAddCommMonoid.toZeroLeOneClass
[CanonicallyOrderedAddCommMonoid α] [One α] : ZeroLEOneClass α :=
⟨zero_le 1⟩
#align canonically_ordered_add_monoid.to_zero_le_one_class canonicallyOrderedAddCommMonoid.toZeroLeOneClass
section LinearOrderedCommGroupWithZero
variable [LinearOrderedCommGroupWithZero α] {a b c d : α} {m n : ℕ}
-- TODO: Do we really need the following two?
theorem mul_le_one₀ (ha : a ≤ 1) (hb : b ≤ 1) : a * b ≤ 1 :=
mul_le_one' ha hb
#align mul_le_one₀ mul_le_one₀
theorem one_le_mul₀ (ha : 1 ≤ a) (hb : 1 ≤ b) : 1 ≤ a * b :=
one_le_mul ha hb
#align one_le_mul₀ one_le_mul₀
theorem le_of_le_mul_right (h : c ≠ 0) (hab : a * c ≤ b * c) : a ≤ b := by
simpa only [mul_inv_cancel_right₀ h] using mul_le_mul_right' hab c⁻¹
#align le_of_le_mul_right le_of_le_mul_right
theorem le_mul_inv_of_mul_le (h : c ≠ 0) (hab : a * c ≤ b) : a ≤ b * c⁻¹ :=
le_of_le_mul_right h (by simpa [h] using hab)
#align le_mul_inv_of_mul_le le_mul_inv_of_mul_le
theorem mul_inv_le_of_le_mul (hab : a ≤ b * c) : a * c⁻¹ ≤ b := by
by_cases h : c = 0
· simp [h]
· exact le_of_le_mul_right h (by simpa [h] using hab)
#align mul_inv_le_of_le_mul mul_inv_le_of_le_mul
theorem inv_le_one₀ (ha : a ≠ 0) : a⁻¹ ≤ 1 ↔ 1 ≤ a :=
@inv_le_one' _ _ _ _ <| Units.mk0 a ha
#align inv_le_one₀ inv_le_one₀
theorem one_le_inv₀ (ha : a ≠ 0) : 1 ≤ a⁻¹ ↔ a ≤ 1 :=
@one_le_inv' _ _ _ _ <| Units.mk0 a ha
#align one_le_inv₀ one_le_inv₀
theorem le_mul_inv_iff₀ (hc : c ≠ 0) : a ≤ b * c⁻¹ ↔ a * c ≤ b :=
⟨fun h ↦ inv_inv c ▸ mul_inv_le_of_le_mul h, le_mul_inv_of_mul_le hc⟩
#align le_mul_inv_iff₀ le_mul_inv_iff₀
theorem mul_inv_le_iff₀ (hc : c ≠ 0) : a * c⁻¹ ≤ b ↔ a ≤ b * c :=
⟨fun h ↦ inv_inv c ▸ le_mul_inv_of_mul_le (inv_ne_zero hc) h, mul_inv_le_of_le_mul⟩
#align mul_inv_le_iff₀ mul_inv_le_iff₀
theorem div_le_div₀ (a b c d : α) (hb : b ≠ 0) (hd : d ≠ 0) :
a * b⁻¹ ≤ c * d⁻¹ ↔ a * d ≤ c * b := by
rw [mul_inv_le_iff₀ hb, mul_right_comm, le_mul_inv_iff₀ hd]
#align div_le_div₀ div_le_div₀
@[simp]
theorem Units.zero_lt (u : αˣ) : (0 : α) < u :=
zero_lt_iff.2 <| u.ne_zero
#align units.zero_lt Units.zero_lt
theorem mul_lt_mul_of_lt_of_le₀ (hab : a ≤ b) (hb : b ≠ 0) (hcd : c < d) : a * c < b * d :=
have hd : d ≠ 0 := ne_zero_of_lt hcd
if ha : a = 0 then by
rw [ha, zero_mul, zero_lt_iff]
exact mul_ne_zero hb hd
else
if hc : c = 0 then by
rw [hc, mul_zero, zero_lt_iff]
exact mul_ne_zero hb hd
else
show Units.mk0 a ha * Units.mk0 c hc < Units.mk0 b hb * Units.mk0 d hd from
mul_lt_mul_of_le_of_lt hab hcd
#align mul_lt_mul_of_lt_of_le₀ mul_lt_mul_of_lt_of_le₀
theorem mul_lt_mul₀ (hab : a < b) (hcd : c < d) : a * c < b * d :=
mul_lt_mul_of_lt_of_le₀ hab.le (ne_zero_of_lt hab) hcd
#align mul_lt_mul₀ mul_lt_mul₀
theorem mul_inv_lt_of_lt_mul₀ (h : a < b * c) : a * c⁻¹ < b := by
contrapose! h
simpa only [inv_inv] using mul_inv_le_of_le_mul h
#align mul_inv_lt_of_lt_mul₀ mul_inv_lt_of_lt_mul₀
theorem inv_mul_lt_of_lt_mul₀ (h : a < b * c) : b⁻¹ * a < c := by
rw [mul_comm] at *
exact mul_inv_lt_of_lt_mul₀ h
#align inv_mul_lt_of_lt_mul₀ inv_mul_lt_of_lt_mul₀
| Mathlib/Algebra/Order/GroupWithZero/Canonical.lean | 196 | 198 | theorem mul_lt_right₀ (c : α) (h : a < b) (hc : c ≠ 0) : a * c < b * c := by |
contrapose! h
exact le_of_le_mul_right hc h
|
import Mathlib.Data.List.Basic
#align_import data.list.lattice from "leanprover-community/mathlib"@"dd71334db81d0bd444af1ee339a29298bef40734"
open Nat
namespace List
variable {α : Type*} {l l₁ l₂ : List α} {p : α → Prop} {a : α}
variable [DecidableEq α]
section BagInter
@[simp]
theorem nil_bagInter (l : List α) : [].bagInter l = [] := by cases l <;> rfl
#align list.nil_bag_inter List.nil_bagInter
@[simp]
theorem bagInter_nil (l : List α) : l.bagInter [] = [] := by cases l <;> rfl
#align list.bag_inter_nil List.bagInter_nil
@[simp]
| Mathlib/Data/List/Lattice.lean | 203 | 207 | theorem cons_bagInter_of_pos (l₁ : List α) (h : a ∈ l₂) :
(a :: l₁).bagInter l₂ = a :: l₁.bagInter (l₂.erase a) := by |
cases l₂
· exact if_pos h
· simp only [List.bagInter, if_pos (elem_eq_true_of_mem h)]
|
import Mathlib.Algebra.GeomSum
import Mathlib.RingTheory.Ideal.Quotient
#align_import number_theory.basic from "leanprover-community/mathlib"@"168ad7fc5d8173ad38be9767a22d50b8ecf1cd00"
section
open Ideal Ideal.Quotient
| Mathlib/NumberTheory/Basic.lean | 29 | 39 | theorem dvd_sub_pow_of_dvd_sub {R : Type*} [CommRing R] {p : ℕ} {a b : R} (h : (p : R) ∣ a - b)
(k : ℕ) : (p ^ (k + 1) : R) ∣ a ^ p ^ k - b ^ p ^ k := by |
induction' k with k ih
· rwa [pow_one, pow_zero, pow_one, pow_one]
rw [pow_succ p k, pow_mul, pow_mul, ← geom_sum₂_mul, pow_succ']
refine mul_dvd_mul ?_ ih
let f : R →+* R ⧸ span {(p : R)} := mk (span {(p : R)})
have hf : ∀ r : R, (p : R) ∣ r ↔ f r = 0 := fun r ↦ by rw [eq_zero_iff_mem, mem_span_singleton]
rw [hf, map_sub, sub_eq_zero] at h
rw [hf, RingHom.map_geom_sum₂, map_pow, map_pow, h, geom_sum₂_self, mul_eq_zero_of_left]
rw [← map_natCast f, eq_zero_iff_mem, mem_span_singleton]
|
import Mathlib.Data.Prod.PProd
import Mathlib.Data.Set.Countable
import Mathlib.Order.Filter.Prod
import Mathlib.Order.Filter.Ker
#align_import order.filter.bases from "leanprover-community/mathlib"@"996b0ff959da753a555053a480f36e5f264d4207"
set_option autoImplicit true
open Set Filter
open scoped Classical
open Filter
section sort
variable {α β γ : Type*} {ι ι' : Sort*}
structure FilterBasis (α : Type*) where
sets : Set (Set α)
nonempty : sets.Nonempty
inter_sets {x y} : x ∈ sets → y ∈ sets → ∃ z ∈ sets, z ⊆ x ∩ y
#align filter_basis FilterBasis
instance FilterBasis.nonempty_sets (B : FilterBasis α) : Nonempty B.sets :=
B.nonempty.to_subtype
#align filter_basis.nonempty_sets FilterBasis.nonempty_sets
-- Porting note: this instance was reducible but it doesn't work the same way in Lean 4
instance {α : Type*} : Membership (Set α) (FilterBasis α) :=
⟨fun U B => U ∈ B.sets⟩
@[simp] theorem FilterBasis.mem_sets {s : Set α} {B : FilterBasis α} : s ∈ B.sets ↔ s ∈ B := Iff.rfl
-- For illustration purposes, the filter basis defining `(atTop : Filter ℕ)`
instance : Inhabited (FilterBasis ℕ) :=
⟨{ sets := range Ici
nonempty := ⟨Ici 0, mem_range_self 0⟩
inter_sets := by
rintro _ _ ⟨n, rfl⟩ ⟨m, rfl⟩
exact ⟨Ici (max n m), mem_range_self _, Ici_inter_Ici.symm.subset⟩ }⟩
def Filter.asBasis (f : Filter α) : FilterBasis α :=
⟨f.sets, ⟨univ, univ_mem⟩, fun {x y} hx hy => ⟨x ∩ y, inter_mem hx hy, subset_rfl⟩⟩
#align filter.as_basis Filter.asBasis
-- Porting note: was `protected` in Lean 3 but `protected` didn't work; removed
structure Filter.IsBasis (p : ι → Prop) (s : ι → Set α) : Prop where
nonempty : ∃ i, p i
inter : ∀ {i j}, p i → p j → ∃ k, p k ∧ s k ⊆ s i ∩ s j
#align filter.is_basis Filter.IsBasis
namespace Filter
-- Porting note: was `protected` in Lean 3 but `protected` didn't work; removed
structure HasBasis (l : Filter α) (p : ι → Prop) (s : ι → Set α) : Prop where
mem_iff' : ∀ t : Set α, t ∈ l ↔ ∃ i, p i ∧ s i ⊆ t
#align filter.has_basis Filter.HasBasis
section SameType
variable {l l' : Filter α} {p : ι → Prop} {s : ι → Set α} {t : Set α} {i : ι} {p' : ι' → Prop}
{s' : ι' → Set α} {i' : ι'}
theorem hasBasis_generate (s : Set (Set α)) :
(generate s).HasBasis (fun t => Set.Finite t ∧ t ⊆ s) fun t => ⋂₀ t :=
⟨fun U => by simp only [mem_generate_iff, exists_prop, and_assoc, and_left_comm]⟩
#align filter.has_basis_generate Filter.hasBasis_generate
def FilterBasis.ofSets (s : Set (Set α)) : FilterBasis α where
sets := sInter '' { t | Set.Finite t ∧ t ⊆ s }
nonempty := ⟨univ, ∅, ⟨⟨finite_empty, empty_subset s⟩, sInter_empty⟩⟩
inter_sets := by
rintro _ _ ⟨a, ⟨fina, suba⟩, rfl⟩ ⟨b, ⟨finb, subb⟩, rfl⟩
exact ⟨⋂₀ (a ∪ b), mem_image_of_mem _ ⟨fina.union finb, union_subset suba subb⟩,
(sInter_union _ _).subset⟩
#align filter.filter_basis.of_sets Filter.FilterBasis.ofSets
lemma FilterBasis.ofSets_sets (s : Set (Set α)) :
(FilterBasis.ofSets s).sets = sInter '' { t | Set.Finite t ∧ t ⊆ s } :=
rfl
-- Porting note: use `∃ i, p i ∧ _` instead of `∃ i (hi : p i), _`.
theorem HasBasis.mem_iff (hl : l.HasBasis p s) : t ∈ l ↔ ∃ i, p i ∧ s i ⊆ t :=
hl.mem_iff' t
#align filter.has_basis.mem_iff Filter.HasBasis.mem_iffₓ
theorem HasBasis.eq_of_same_basis (hl : l.HasBasis p s) (hl' : l'.HasBasis p s) : l = l' := by
ext t
rw [hl.mem_iff, hl'.mem_iff]
#align filter.has_basis.eq_of_same_basis Filter.HasBasis.eq_of_same_basis
-- Porting note: use `∃ i, p i ∧ _` instead of `∃ i (hi : p i), _`.
theorem hasBasis_iff : l.HasBasis p s ↔ ∀ t, t ∈ l ↔ ∃ i, p i ∧ s i ⊆ t :=
⟨fun ⟨h⟩ => h, fun h => ⟨h⟩⟩
#align filter.has_basis_iff Filter.hasBasis_iffₓ
theorem HasBasis.ex_mem (h : l.HasBasis p s) : ∃ i, p i :=
(h.mem_iff.mp univ_mem).imp fun _ => And.left
#align filter.has_basis.ex_mem Filter.HasBasis.ex_mem
protected theorem HasBasis.nonempty (h : l.HasBasis p s) : Nonempty ι :=
nonempty_of_exists h.ex_mem
#align filter.has_basis.nonempty Filter.HasBasis.nonempty
protected theorem IsBasis.hasBasis (h : IsBasis p s) : HasBasis h.filter p s :=
⟨fun t => by simp only [h.mem_filter_iff, exists_prop]⟩
#align filter.is_basis.has_basis Filter.IsBasis.hasBasis
protected theorem HasBasis.mem_of_superset (hl : l.HasBasis p s) (hi : p i) (ht : s i ⊆ t) :
t ∈ l :=
hl.mem_iff.2 ⟨i, hi, ht⟩
#align filter.has_basis.mem_of_superset Filter.HasBasis.mem_of_superset
theorem HasBasis.mem_of_mem (hl : l.HasBasis p s) (hi : p i) : s i ∈ l :=
hl.mem_of_superset hi Subset.rfl
#align filter.has_basis.mem_of_mem Filter.HasBasis.mem_of_mem
noncomputable def HasBasis.index (h : l.HasBasis p s) (t : Set α) (ht : t ∈ l) : { i : ι // p i } :=
⟨(h.mem_iff.1 ht).choose, (h.mem_iff.1 ht).choose_spec.1⟩
#align filter.has_basis.index Filter.HasBasis.index
theorem HasBasis.property_index (h : l.HasBasis p s) (ht : t ∈ l) : p (h.index t ht) :=
(h.index t ht).2
#align filter.has_basis.property_index Filter.HasBasis.property_index
theorem HasBasis.set_index_mem (h : l.HasBasis p s) (ht : t ∈ l) : s (h.index t ht) ∈ l :=
h.mem_of_mem <| h.property_index _
#align filter.has_basis.set_index_mem Filter.HasBasis.set_index_mem
theorem HasBasis.set_index_subset (h : l.HasBasis p s) (ht : t ∈ l) : s (h.index t ht) ⊆ t :=
(h.mem_iff.1 ht).choose_spec.2
#align filter.has_basis.set_index_subset Filter.HasBasis.set_index_subset
theorem HasBasis.isBasis (h : l.HasBasis p s) : IsBasis p s where
nonempty := h.ex_mem
inter hi hj := by
simpa only [h.mem_iff] using inter_mem (h.mem_of_mem hi) (h.mem_of_mem hj)
#align filter.has_basis.is_basis Filter.HasBasis.isBasis
theorem HasBasis.filter_eq (h : l.HasBasis p s) : h.isBasis.filter = l := by
ext U
simp [h.mem_iff, IsBasis.mem_filter_iff]
#align filter.has_basis.filter_eq Filter.HasBasis.filter_eq
theorem HasBasis.eq_generate (h : l.HasBasis p s) : l = generate { U | ∃ i, p i ∧ s i = U } := by
rw [← h.isBasis.filter_eq_generate, h.filter_eq]
#align filter.has_basis.eq_generate Filter.HasBasis.eq_generate
theorem generate_eq_generate_inter (s : Set (Set α)) :
generate s = generate (sInter '' { t | Set.Finite t ∧ t ⊆ s }) := by
rw [← FilterBasis.ofSets_sets, FilterBasis.generate, ← (hasBasis_generate s).filter_eq]; rfl
#align filter.generate_eq_generate_inter Filter.generate_eq_generate_inter
theorem ofSets_filter_eq_generate (s : Set (Set α)) :
(FilterBasis.ofSets s).filter = generate s := by
rw [← (FilterBasis.ofSets s).generate, FilterBasis.ofSets_sets, ← generate_eq_generate_inter]
#align filter.of_sets_filter_eq_generate Filter.ofSets_filter_eq_generate
protected theorem _root_.FilterBasis.hasBasis (B : FilterBasis α) :
HasBasis B.filter (fun s : Set α => s ∈ B) id :=
⟨fun _ => B.mem_filter_iff⟩
#align filter_basis.has_basis FilterBasis.hasBasis
theorem HasBasis.to_hasBasis' (hl : l.HasBasis p s) (h : ∀ i, p i → ∃ i', p' i' ∧ s' i' ⊆ s i)
(h' : ∀ i', p' i' → s' i' ∈ l) : l.HasBasis p' s' := by
refine ⟨fun t => ⟨fun ht => ?_, fun ⟨i', hi', ht⟩ => mem_of_superset (h' i' hi') ht⟩⟩
rcases hl.mem_iff.1 ht with ⟨i, hi, ht⟩
rcases h i hi with ⟨i', hi', hs's⟩
exact ⟨i', hi', hs's.trans ht⟩
#align filter.has_basis.to_has_basis' Filter.HasBasis.to_hasBasis'
theorem HasBasis.to_hasBasis (hl : l.HasBasis p s) (h : ∀ i, p i → ∃ i', p' i' ∧ s' i' ⊆ s i)
(h' : ∀ i', p' i' → ∃ i, p i ∧ s i ⊆ s' i') : l.HasBasis p' s' :=
hl.to_hasBasis' h fun i' hi' =>
let ⟨i, hi, hss'⟩ := h' i' hi'
hl.mem_iff.2 ⟨i, hi, hss'⟩
#align filter.has_basis.to_has_basis Filter.HasBasis.to_hasBasis
protected lemma HasBasis.congr (hl : l.HasBasis p s) {p' s'} (hp : ∀ i, p i ↔ p' i)
(hs : ∀ i, p i → s i = s' i) : l.HasBasis p' s' :=
⟨fun t ↦ by simp only [hl.mem_iff, ← hp]; exact exists_congr fun i ↦
and_congr_right fun hi ↦ hs i hi ▸ Iff.rfl⟩
theorem HasBasis.to_subset (hl : l.HasBasis p s) {t : ι → Set α} (h : ∀ i, p i → t i ⊆ s i)
(ht : ∀ i, p i → t i ∈ l) : l.HasBasis p t :=
hl.to_hasBasis' (fun i hi => ⟨i, hi, h i hi⟩) ht
#align filter.has_basis.to_subset Filter.HasBasis.to_subset
theorem HasBasis.eventually_iff (hl : l.HasBasis p s) {q : α → Prop} :
(∀ᶠ x in l, q x) ↔ ∃ i, p i ∧ ∀ ⦃x⦄, x ∈ s i → q x := by simpa using hl.mem_iff
#align filter.has_basis.eventually_iff Filter.HasBasis.eventually_iff
theorem HasBasis.frequently_iff (hl : l.HasBasis p s) {q : α → Prop} :
(∃ᶠ x in l, q x) ↔ ∀ i, p i → ∃ x ∈ s i, q x := by
simp only [Filter.Frequently, hl.eventually_iff]; push_neg; rfl
#align filter.has_basis.frequently_iff Filter.HasBasis.frequently_iff
-- Porting note: use `∃ i, p i ∧ _` instead of `∃ i (hi : p i), _`.
theorem HasBasis.exists_iff (hl : l.HasBasis p s) {P : Set α → Prop}
(mono : ∀ ⦃s t⦄, s ⊆ t → P t → P s) : (∃ s ∈ l, P s) ↔ ∃ i, p i ∧ P (s i) :=
⟨fun ⟨_s, hs, hP⟩ =>
let ⟨i, hi, his⟩ := hl.mem_iff.1 hs
⟨i, hi, mono his hP⟩,
fun ⟨i, hi, hP⟩ => ⟨s i, hl.mem_of_mem hi, hP⟩⟩
#align filter.has_basis.exists_iff Filter.HasBasis.exists_iffₓ
theorem HasBasis.forall_iff (hl : l.HasBasis p s) {P : Set α → Prop}
(mono : ∀ ⦃s t⦄, s ⊆ t → P s → P t) : (∀ s ∈ l, P s) ↔ ∀ i, p i → P (s i) :=
⟨fun H i hi => H (s i) <| hl.mem_of_mem hi, fun H _s hs =>
let ⟨i, hi, his⟩ := hl.mem_iff.1 hs
mono his (H i hi)⟩
#align filter.has_basis.forall_iff Filter.HasBasis.forall_iff
protected theorem HasBasis.neBot_iff (hl : l.HasBasis p s) :
NeBot l ↔ ∀ {i}, p i → (s i).Nonempty :=
forall_mem_nonempty_iff_neBot.symm.trans <| hl.forall_iff fun _ _ => Nonempty.mono
#align filter.has_basis.ne_bot_iff Filter.HasBasis.neBot_iff
theorem HasBasis.eq_bot_iff (hl : l.HasBasis p s) : l = ⊥ ↔ ∃ i, p i ∧ s i = ∅ :=
not_iff_not.1 <| neBot_iff.symm.trans <|
hl.neBot_iff.trans <| by simp only [not_exists, not_and, nonempty_iff_ne_empty]
#align filter.has_basis.eq_bot_iff Filter.HasBasis.eq_bot_iff
theorem generate_neBot_iff {s : Set (Set α)} :
NeBot (generate s) ↔ ∀ t, t ⊆ s → t.Finite → (⋂₀ t).Nonempty :=
(hasBasis_generate s).neBot_iff.trans <| by simp only [← and_imp, and_comm]
#align filter.generate_ne_bot_iff Filter.generate_neBot_iff
theorem basis_sets (l : Filter α) : l.HasBasis (fun s : Set α => s ∈ l) id :=
⟨fun _ => exists_mem_subset_iff.symm⟩
#align filter.basis_sets Filter.basis_sets
theorem asBasis_filter (f : Filter α) : f.asBasis.filter = f :=
Filter.ext fun _ => exists_mem_subset_iff
#align filter.as_basis_filter Filter.asBasis_filter
theorem hasBasis_self {l : Filter α} {P : Set α → Prop} :
HasBasis l (fun s => s ∈ l ∧ P s) id ↔ ∀ t ∈ l, ∃ r ∈ l, P r ∧ r ⊆ t := by
simp only [hasBasis_iff, id, and_assoc]
exact forall_congr' fun s =>
⟨fun h => h.1, fun h => ⟨h, fun ⟨t, hl, _, hts⟩ => mem_of_superset hl hts⟩⟩
#align filter.has_basis_self Filter.hasBasis_self
theorem HasBasis.comp_surjective (h : l.HasBasis p s) {g : ι' → ι} (hg : Function.Surjective g) :
l.HasBasis (p ∘ g) (s ∘ g) :=
⟨fun _ => h.mem_iff.trans hg.exists⟩
#align filter.has_basis.comp_surjective Filter.HasBasis.comp_surjective
theorem HasBasis.comp_equiv (h : l.HasBasis p s) (e : ι' ≃ ι) : l.HasBasis (p ∘ e) (s ∘ e) :=
h.comp_surjective e.surjective
#align filter.has_basis.comp_equiv Filter.HasBasis.comp_equiv
theorem HasBasis.to_image_id' (h : l.HasBasis p s) : l.HasBasis (fun t ↦ ∃ i, p i ∧ s i = t) id :=
⟨fun _ ↦ by simp [h.mem_iff]⟩
theorem HasBasis.to_image_id {ι : Type*} {p : ι → Prop} {s : ι → Set α} (h : l.HasBasis p s) :
l.HasBasis (· ∈ s '' {i | p i}) id :=
h.to_image_id'
theorem HasBasis.restrict (h : l.HasBasis p s) {q : ι → Prop}
(hq : ∀ i, p i → ∃ j, p j ∧ q j ∧ s j ⊆ s i) : l.HasBasis (fun i => p i ∧ q i) s := by
refine ⟨fun t => ⟨fun ht => ?_, fun ⟨i, hpi, hti⟩ => h.mem_iff.2 ⟨i, hpi.1, hti⟩⟩⟩
rcases h.mem_iff.1 ht with ⟨i, hpi, hti⟩
rcases hq i hpi with ⟨j, hpj, hqj, hji⟩
exact ⟨j, ⟨hpj, hqj⟩, hji.trans hti⟩
#align filter.has_basis.restrict Filter.HasBasis.restrict
theorem HasBasis.restrict_subset (h : l.HasBasis p s) {V : Set α} (hV : V ∈ l) :
l.HasBasis (fun i => p i ∧ s i ⊆ V) s :=
h.restrict fun _i hi => (h.mem_iff.1 (inter_mem hV (h.mem_of_mem hi))).imp fun _j hj =>
⟨hj.1, subset_inter_iff.1 hj.2⟩
#align filter.has_basis.restrict_subset Filter.HasBasis.restrict_subset
theorem HasBasis.hasBasis_self_subset {p : Set α → Prop} (h : l.HasBasis (fun s => s ∈ l ∧ p s) id)
{V : Set α} (hV : V ∈ l) : l.HasBasis (fun s => s ∈ l ∧ p s ∧ s ⊆ V) id := by
simpa only [and_assoc] using h.restrict_subset hV
#align filter.has_basis.has_basis_self_subset Filter.HasBasis.hasBasis_self_subset
theorem HasBasis.ge_iff (hl' : l'.HasBasis p' s') : l ≤ l' ↔ ∀ i', p' i' → s' i' ∈ l :=
⟨fun h _i' hi' => h <| hl'.mem_of_mem hi', fun h _s hs =>
let ⟨_i', hi', hs⟩ := hl'.mem_iff.1 hs
mem_of_superset (h _ hi') hs⟩
#align filter.has_basis.ge_iff Filter.HasBasis.ge_iff
-- Porting note: use `∃ i, p i ∧ _` instead of `∃ i (hi : p i), _`.
theorem HasBasis.le_iff (hl : l.HasBasis p s) : l ≤ l' ↔ ∀ t ∈ l', ∃ i, p i ∧ s i ⊆ t := by
simp only [le_def, hl.mem_iff]
#align filter.has_basis.le_iff Filter.HasBasis.le_iffₓ
-- Porting note: use `∃ i, p i ∧ _` instead of `∃ i (hi : p i), _`.
theorem HasBasis.le_basis_iff (hl : l.HasBasis p s) (hl' : l'.HasBasis p' s') :
l ≤ l' ↔ ∀ i', p' i' → ∃ i, p i ∧ s i ⊆ s' i' := by
simp only [hl'.ge_iff, hl.mem_iff]
#align filter.has_basis.le_basis_iff Filter.HasBasis.le_basis_iffₓ
-- Porting note: use `∃ i, p i ∧ _` instead of `∃ i (hi : p i), _`.
theorem HasBasis.ext (hl : l.HasBasis p s) (hl' : l'.HasBasis p' s')
(h : ∀ i, p i → ∃ i', p' i' ∧ s' i' ⊆ s i) (h' : ∀ i', p' i' → ∃ i, p i ∧ s i ⊆ s' i') :
l = l' := by
apply le_antisymm
· rw [hl.le_basis_iff hl']
simpa using h'
· rw [hl'.le_basis_iff hl]
simpa using h
#align filter.has_basis.ext Filter.HasBasis.extₓ
theorem HasBasis.inf' (hl : l.HasBasis p s) (hl' : l'.HasBasis p' s') :
(l ⊓ l').HasBasis (fun i : PProd ι ι' => p i.1 ∧ p' i.2) fun i => s i.1 ∩ s' i.2 :=
⟨by
intro t
constructor
· simp only [mem_inf_iff, hl.mem_iff, hl'.mem_iff]
rintro ⟨t, ⟨i, hi, ht⟩, t', ⟨i', hi', ht'⟩, rfl⟩
exact ⟨⟨i, i'⟩, ⟨hi, hi'⟩, inter_subset_inter ht ht'⟩
· rintro ⟨⟨i, i'⟩, ⟨hi, hi'⟩, H⟩
exact mem_inf_of_inter (hl.mem_of_mem hi) (hl'.mem_of_mem hi') H⟩
#align filter.has_basis.inf' Filter.HasBasis.inf'
theorem HasBasis.inf {ι ι' : Type*} {p : ι → Prop} {s : ι → Set α} {p' : ι' → Prop}
{s' : ι' → Set α} (hl : l.HasBasis p s) (hl' : l'.HasBasis p' s') :
(l ⊓ l').HasBasis (fun i : ι × ι' => p i.1 ∧ p' i.2) fun i => s i.1 ∩ s' i.2 :=
(hl.inf' hl').comp_equiv Equiv.pprodEquivProd.symm
#align filter.has_basis.inf Filter.HasBasis.inf
theorem hasBasis_iInf' {ι : Type*} {ι' : ι → Type*} {l : ι → Filter α} {p : ∀ i, ι' i → Prop}
{s : ∀ i, ι' i → Set α} (hl : ∀ i, (l i).HasBasis (p i) (s i)) :
(⨅ i, l i).HasBasis (fun If : Set ι × ∀ i, ι' i => If.1.Finite ∧ ∀ i ∈ If.1, p i (If.2 i))
fun If : Set ι × ∀ i, ι' i => ⋂ i ∈ If.1, s i (If.2 i) :=
⟨by
intro t
constructor
· simp only [mem_iInf', (hl _).mem_iff]
rintro ⟨I, hI, V, hV, -, rfl, -⟩
choose u hu using hV
exact ⟨⟨I, u⟩, ⟨hI, fun i _ => (hu i).1⟩, iInter₂_mono fun i _ => (hu i).2⟩
· rintro ⟨⟨I, f⟩, ⟨hI₁, hI₂⟩, hsub⟩
refine mem_of_superset ?_ hsub
exact (biInter_mem hI₁).mpr fun i hi => mem_iInf_of_mem i <| (hl i).mem_of_mem <| hI₂ _ hi⟩
#align filter.has_basis_infi' Filter.hasBasis_iInf'
theorem hasBasis_iInf {ι : Type*} {ι' : ι → Type*} {l : ι → Filter α} {p : ∀ i, ι' i → Prop}
{s : ∀ i, ι' i → Set α} (hl : ∀ i, (l i).HasBasis (p i) (s i)) :
(⨅ i, l i).HasBasis
(fun If : Σ I : Set ι, ∀ i : I, ι' i => If.1.Finite ∧ ∀ i : If.1, p i (If.2 i)) fun If =>
⋂ i : If.1, s i (If.2 i) := by
refine ⟨fun t => ⟨fun ht => ?_, ?_⟩⟩
· rcases (hasBasis_iInf' hl).mem_iff.mp ht with ⟨⟨I, f⟩, ⟨hI, hf⟩, hsub⟩
exact ⟨⟨I, fun i => f i⟩, ⟨hI, Subtype.forall.mpr hf⟩, trans (iInter_subtype _ _) hsub⟩
· rintro ⟨⟨I, f⟩, ⟨hI, hf⟩, hsub⟩
refine mem_of_superset ?_ hsub
cases hI.nonempty_fintype
exact iInter_mem.2 fun i => mem_iInf_of_mem ↑i <| (hl i).mem_of_mem <| hf _
#align filter.has_basis_infi Filter.hasBasis_iInf
theorem hasBasis_iInf_of_directed' {ι : Type*} {ι' : ι → Sort _} [Nonempty ι] {l : ι → Filter α}
(s : ∀ i, ι' i → Set α) (p : ∀ i, ι' i → Prop) (hl : ∀ i, (l i).HasBasis (p i) (s i))
(h : Directed (· ≥ ·) l) :
(⨅ i, l i).HasBasis (fun ii' : Σi, ι' i => p ii'.1 ii'.2) fun ii' => s ii'.1 ii'.2 := by
refine ⟨fun t => ?_⟩
rw [mem_iInf_of_directed h, Sigma.exists]
exact exists_congr fun i => (hl i).mem_iff
#align filter.has_basis_infi_of_directed' Filter.hasBasis_iInf_of_directed'
theorem hasBasis_iInf_of_directed {ι : Type*} {ι' : Sort _} [Nonempty ι] {l : ι → Filter α}
(s : ι → ι' → Set α) (p : ι → ι' → Prop) (hl : ∀ i, (l i).HasBasis (p i) (s i))
(h : Directed (· ≥ ·) l) :
(⨅ i, l i).HasBasis (fun ii' : ι × ι' => p ii'.1 ii'.2) fun ii' => s ii'.1 ii'.2 := by
refine ⟨fun t => ?_⟩
rw [mem_iInf_of_directed h, Prod.exists]
exact exists_congr fun i => (hl i).mem_iff
#align filter.has_basis_infi_of_directed Filter.hasBasis_iInf_of_directed
theorem hasBasis_biInf_of_directed' {ι : Type*} {ι' : ι → Sort _} {dom : Set ι}
(hdom : dom.Nonempty) {l : ι → Filter α} (s : ∀ i, ι' i → Set α) (p : ∀ i, ι' i → Prop)
(hl : ∀ i ∈ dom, (l i).HasBasis (p i) (s i)) (h : DirectedOn (l ⁻¹'o GE.ge) dom) :
(⨅ i ∈ dom, l i).HasBasis (fun ii' : Σi, ι' i => ii'.1 ∈ dom ∧ p ii'.1 ii'.2) fun ii' =>
s ii'.1 ii'.2 := by
refine ⟨fun t => ?_⟩
rw [mem_biInf_of_directed h hdom, Sigma.exists]
refine exists_congr fun i => ⟨?_, ?_⟩
· rintro ⟨hi, hti⟩
rcases (hl i hi).mem_iff.mp hti with ⟨b, hb, hbt⟩
exact ⟨b, ⟨hi, hb⟩, hbt⟩
· rintro ⟨b, ⟨hi, hb⟩, hibt⟩
exact ⟨hi, (hl i hi).mem_iff.mpr ⟨b, hb, hibt⟩⟩
#align filter.has_basis_binfi_of_directed' Filter.hasBasis_biInf_of_directed'
theorem hasBasis_biInf_of_directed {ι : Type*} {ι' : Sort _} {dom : Set ι} (hdom : dom.Nonempty)
{l : ι → Filter α} (s : ι → ι' → Set α) (p : ι → ι' → Prop)
(hl : ∀ i ∈ dom, (l i).HasBasis (p i) (s i)) (h : DirectedOn (l ⁻¹'o GE.ge) dom) :
(⨅ i ∈ dom, l i).HasBasis (fun ii' : ι × ι' => ii'.1 ∈ dom ∧ p ii'.1 ii'.2) fun ii' =>
s ii'.1 ii'.2 := by
refine ⟨fun t => ?_⟩
rw [mem_biInf_of_directed h hdom, Prod.exists]
refine exists_congr fun i => ⟨?_, ?_⟩
· rintro ⟨hi, hti⟩
rcases (hl i hi).mem_iff.mp hti with ⟨b, hb, hbt⟩
exact ⟨b, ⟨hi, hb⟩, hbt⟩
· rintro ⟨b, ⟨hi, hb⟩, hibt⟩
exact ⟨hi, (hl i hi).mem_iff.mpr ⟨b, hb, hibt⟩⟩
#align filter.has_basis_binfi_of_directed Filter.hasBasis_biInf_of_directed
theorem hasBasis_principal (t : Set α) : (𝓟 t).HasBasis (fun _ : Unit => True) fun _ => t :=
⟨fun U => by simp⟩
#align filter.has_basis_principal Filter.hasBasis_principal
theorem hasBasis_pure (x : α) :
(pure x : Filter α).HasBasis (fun _ : Unit => True) fun _ => {x} := by
simp only [← principal_singleton, hasBasis_principal]
#align filter.has_basis_pure Filter.hasBasis_pure
theorem HasBasis.sup' (hl : l.HasBasis p s) (hl' : l'.HasBasis p' s') :
(l ⊔ l').HasBasis (fun i : PProd ι ι' => p i.1 ∧ p' i.2) fun i => s i.1 ∪ s' i.2 :=
⟨by
intro t
simp_rw [mem_sup, hl.mem_iff, hl'.mem_iff, PProd.exists, union_subset_iff,
← exists_and_right, ← exists_and_left]
simp only [and_assoc, and_left_comm]⟩
#align filter.has_basis.sup' Filter.HasBasis.sup'
theorem HasBasis.sup {ι ι' : Type*} {p : ι → Prop} {s : ι → Set α} {p' : ι' → Prop}
{s' : ι' → Set α} (hl : l.HasBasis p s) (hl' : l'.HasBasis p' s') :
(l ⊔ l').HasBasis (fun i : ι × ι' => p i.1 ∧ p' i.2) fun i => s i.1 ∪ s' i.2 :=
(hl.sup' hl').comp_equiv Equiv.pprodEquivProd.symm
#align filter.has_basis.sup Filter.HasBasis.sup
theorem hasBasis_iSup {ι : Sort*} {ι' : ι → Type*} {l : ι → Filter α} {p : ∀ i, ι' i → Prop}
{s : ∀ i, ι' i → Set α} (hl : ∀ i, (l i).HasBasis (p i) (s i)) :
(⨆ i, l i).HasBasis (fun f : ∀ i, ι' i => ∀ i, p i (f i)) fun f : ∀ i, ι' i => ⋃ i, s i (f i) :=
hasBasis_iff.mpr fun t => by
simp only [hasBasis_iff, (hl _).mem_iff, Classical.skolem, forall_and, iUnion_subset_iff,
mem_iSup]
#align filter.has_basis_supr Filter.hasBasis_iSup
theorem HasBasis.sup_principal (hl : l.HasBasis p s) (t : Set α) :
(l ⊔ 𝓟 t).HasBasis p fun i => s i ∪ t :=
⟨fun u => by
simp only [(hl.sup' (hasBasis_principal t)).mem_iff, PProd.exists, exists_prop, and_true_iff,
Unique.exists_iff]⟩
#align filter.has_basis.sup_principal Filter.HasBasis.sup_principal
theorem HasBasis.sup_pure (hl : l.HasBasis p s) (x : α) :
(l ⊔ pure x).HasBasis p fun i => s i ∪ {x} := by
simp only [← principal_singleton, hl.sup_principal]
#align filter.has_basis.sup_pure Filter.HasBasis.sup_pure
theorem HasBasis.inf_principal (hl : l.HasBasis p s) (s' : Set α) :
(l ⊓ 𝓟 s').HasBasis p fun i => s i ∩ s' :=
⟨fun t => by
simp only [mem_inf_principal, hl.mem_iff, subset_def, mem_setOf_eq, mem_inter_iff, and_imp]⟩
#align filter.has_basis.inf_principal Filter.HasBasis.inf_principal
theorem HasBasis.principal_inf (hl : l.HasBasis p s) (s' : Set α) :
(𝓟 s' ⊓ l).HasBasis p fun i => s' ∩ s i := by
simpa only [inf_comm, inter_comm] using hl.inf_principal s'
#align filter.has_basis.principal_inf Filter.HasBasis.principal_inf
theorem HasBasis.inf_basis_neBot_iff (hl : l.HasBasis p s) (hl' : l'.HasBasis p' s') :
NeBot (l ⊓ l') ↔ ∀ ⦃i⦄, p i → ∀ ⦃i'⦄, p' i' → (s i ∩ s' i').Nonempty :=
(hl.inf' hl').neBot_iff.trans <| by simp [@forall_swap _ ι']
#align filter.has_basis.inf_basis_ne_bot_iff Filter.HasBasis.inf_basis_neBot_iff
theorem HasBasis.inf_neBot_iff (hl : l.HasBasis p s) :
NeBot (l ⊓ l') ↔ ∀ ⦃i⦄, p i → ∀ ⦃s'⦄, s' ∈ l' → (s i ∩ s').Nonempty :=
hl.inf_basis_neBot_iff l'.basis_sets
#align filter.has_basis.inf_ne_bot_iff Filter.HasBasis.inf_neBot_iff
theorem HasBasis.inf_principal_neBot_iff (hl : l.HasBasis p s) {t : Set α} :
NeBot (l ⊓ 𝓟 t) ↔ ∀ ⦃i⦄, p i → (s i ∩ t).Nonempty :=
(hl.inf_principal t).neBot_iff
#align filter.has_basis.inf_principal_ne_bot_iff Filter.HasBasis.inf_principal_neBot_iff
-- Porting note: use `∃ i, p i ∧ _` instead of `∃ i (hi : p i), _`.
theorem HasBasis.disjoint_iff (hl : l.HasBasis p s) (hl' : l'.HasBasis p' s') :
Disjoint l l' ↔ ∃ i, p i ∧ ∃ i', p' i' ∧ Disjoint (s i) (s' i') :=
not_iff_not.mp <| by simp only [_root_.disjoint_iff, ← Ne.eq_def, ← neBot_iff, inf_eq_inter,
hl.inf_basis_neBot_iff hl', not_exists, not_and, bot_eq_empty, ← nonempty_iff_ne_empty]
#align filter.has_basis.disjoint_iff Filter.HasBasis.disjoint_iffₓ
-- Porting note: use `∃ i, p i ∧ _` instead of `∃ i (hi : p i), _`.
theorem _root_.Disjoint.exists_mem_filter_basis (h : Disjoint l l') (hl : l.HasBasis p s)
(hl' : l'.HasBasis p' s') : ∃ i, p i ∧ ∃ i', p' i' ∧ Disjoint (s i) (s' i') :=
(hl.disjoint_iff hl').1 h
#align disjoint.exists_mem_filter_basis Disjoint.exists_mem_filter_basisₓ
theorem _root_.Pairwise.exists_mem_filter_basis_of_disjoint {I} [Finite I] {l : I → Filter α}
{ι : I → Sort*} {p : ∀ i, ι i → Prop} {s : ∀ i, ι i → Set α} (hd : Pairwise (Disjoint on l))
(h : ∀ i, (l i).HasBasis (p i) (s i)) :
∃ ind : ∀ i, ι i, (∀ i, p i (ind i)) ∧ Pairwise (Disjoint on fun i => s i (ind i)) := by
rcases hd.exists_mem_filter_of_disjoint with ⟨t, htl, hd⟩
choose ind hp ht using fun i => (h i).mem_iff.1 (htl i)
exact ⟨ind, hp, hd.mono fun i j hij => hij.mono (ht _) (ht _)⟩
#align pairwise.exists_mem_filter_basis_of_disjoint Pairwise.exists_mem_filter_basis_of_disjoint
theorem _root_.Set.PairwiseDisjoint.exists_mem_filter_basis {I : Type*} {l : I → Filter α}
{ι : I → Sort*} {p : ∀ i, ι i → Prop} {s : ∀ i, ι i → Set α} {S : Set I}
(hd : S.PairwiseDisjoint l) (hS : S.Finite) (h : ∀ i, (l i).HasBasis (p i) (s i)) :
∃ ind : ∀ i, ι i, (∀ i, p i (ind i)) ∧ S.PairwiseDisjoint fun i => s i (ind i) := by
rcases hd.exists_mem_filter hS with ⟨t, htl, hd⟩
choose ind hp ht using fun i => (h i).mem_iff.1 (htl i)
exact ⟨ind, hp, hd.mono ht⟩
#align set.pairwise_disjoint.exists_mem_filter_basis Set.PairwiseDisjoint.exists_mem_filter_basis
theorem inf_neBot_iff :
NeBot (l ⊓ l') ↔ ∀ ⦃s : Set α⦄, s ∈ l → ∀ ⦃s'⦄, s' ∈ l' → (s ∩ s').Nonempty :=
l.basis_sets.inf_neBot_iff
#align filter.inf_ne_bot_iff Filter.inf_neBot_iff
theorem inf_principal_neBot_iff {s : Set α} : NeBot (l ⊓ 𝓟 s) ↔ ∀ U ∈ l, (U ∩ s).Nonempty :=
l.basis_sets.inf_principal_neBot_iff
#align filter.inf_principal_ne_bot_iff Filter.inf_principal_neBot_iff
theorem mem_iff_inf_principal_compl {f : Filter α} {s : Set α} : s ∈ f ↔ f ⊓ 𝓟 sᶜ = ⊥ := by
refine not_iff_not.1 ((inf_principal_neBot_iff.trans ?_).symm.trans neBot_iff)
exact
⟨fun h hs => by simpa [Set.not_nonempty_empty] using h s hs, fun hs t ht =>
inter_compl_nonempty_iff.2 fun hts => hs <| mem_of_superset ht hts⟩
#align filter.mem_iff_inf_principal_compl Filter.mem_iff_inf_principal_compl
theorem not_mem_iff_inf_principal_compl {f : Filter α} {s : Set α} : s ∉ f ↔ NeBot (f ⊓ 𝓟 sᶜ) :=
(not_congr mem_iff_inf_principal_compl).trans neBot_iff.symm
#align filter.not_mem_iff_inf_principal_compl Filter.not_mem_iff_inf_principal_compl
@[simp]
theorem disjoint_principal_right {f : Filter α} {s : Set α} : Disjoint f (𝓟 s) ↔ sᶜ ∈ f := by
rw [mem_iff_inf_principal_compl, compl_compl, disjoint_iff]
#align filter.disjoint_principal_right Filter.disjoint_principal_right
@[simp]
theorem disjoint_principal_left {f : Filter α} {s : Set α} : Disjoint (𝓟 s) f ↔ sᶜ ∈ f := by
rw [disjoint_comm, disjoint_principal_right]
#align filter.disjoint_principal_left Filter.disjoint_principal_left
@[simp 1100] -- Porting note: higher priority for linter
theorem disjoint_principal_principal {s t : Set α} : Disjoint (𝓟 s) (𝓟 t) ↔ Disjoint s t := by
rw [← subset_compl_iff_disjoint_left, disjoint_principal_left, mem_principal]
#align filter.disjoint_principal_principal Filter.disjoint_principal_principal
alias ⟨_, _root_.Disjoint.filter_principal⟩ := disjoint_principal_principal
#align disjoint.filter_principal Disjoint.filter_principal
@[simp]
theorem disjoint_pure_pure {x y : α} : Disjoint (pure x : Filter α) (pure y) ↔ x ≠ y := by
simp only [← principal_singleton, disjoint_principal_principal, disjoint_singleton]
#align filter.disjoint_pure_pure Filter.disjoint_pure_pure
@[simp]
theorem compl_diagonal_mem_prod {l₁ l₂ : Filter α} : (diagonal α)ᶜ ∈ l₁ ×ˢ l₂ ↔ Disjoint l₁ l₂ := by
simp only [mem_prod_iff, Filter.disjoint_iff, prod_subset_compl_diagonal_iff_disjoint]
#align filter.compl_diagonal_mem_prod Filter.compl_diagonal_mem_prod
-- Porting note: use `∃ i, p i ∧ _` instead of `∃ i (hi : p i), _`.
theorem HasBasis.disjoint_iff_left (h : l.HasBasis p s) :
Disjoint l l' ↔ ∃ i, p i ∧ (s i)ᶜ ∈ l' := by
simp only [h.disjoint_iff l'.basis_sets, id, ← disjoint_principal_left,
(hasBasis_principal _).disjoint_iff l'.basis_sets, true_and, Unique.exists_iff]
#align filter.has_basis.disjoint_iff_left Filter.HasBasis.disjoint_iff_leftₓ
-- Porting note: use `∃ i, p i ∧ _` instead of `∃ i (hi : p i), _`.
theorem HasBasis.disjoint_iff_right (h : l.HasBasis p s) :
Disjoint l' l ↔ ∃ i, p i ∧ (s i)ᶜ ∈ l' :=
disjoint_comm.trans h.disjoint_iff_left
#align filter.has_basis.disjoint_iff_right Filter.HasBasis.disjoint_iff_rightₓ
theorem le_iff_forall_inf_principal_compl {f g : Filter α} : f ≤ g ↔ ∀ V ∈ g, f ⊓ 𝓟 Vᶜ = ⊥ :=
forall₂_congr fun _ _ => mem_iff_inf_principal_compl
#align filter.le_iff_forall_inf_principal_compl Filter.le_iff_forall_inf_principal_compl
| Mathlib/Order/Filter/Bases.lean | 755 | 757 | theorem inf_neBot_iff_frequently_left {f g : Filter α} :
NeBot (f ⊓ g) ↔ ∀ {p : α → Prop}, (∀ᶠ x in f, p x) → ∃ᶠ x in g, p x := by |
simp only [inf_neBot_iff, frequently_iff, and_comm]; rfl
|
import Mathlib.Combinatorics.SimpleGraph.Subgraph
import Mathlib.Data.List.Rotate
#align_import combinatorics.simple_graph.connectivity from "leanprover-community/mathlib"@"b99e2d58a5e6861833fa8de11e51a81144258db4"
open Function
universe u v w
namespace SimpleGraph
variable {V : Type u} {V' : Type v} {V'' : Type w}
variable (G : SimpleGraph V) (G' : SimpleGraph V') (G'' : SimpleGraph V'')
inductive Walk : V → V → Type u
| nil {u : V} : Walk u u
| cons {u v w : V} (h : G.Adj u v) (p : Walk v w) : Walk u w
deriving DecidableEq
#align simple_graph.walk SimpleGraph.Walk
attribute [refl] Walk.nil
@[simps]
instance Walk.instInhabited (v : V) : Inhabited (G.Walk v v) := ⟨Walk.nil⟩
#align simple_graph.walk.inhabited SimpleGraph.Walk.instInhabited
@[match_pattern, reducible]
def Adj.toWalk {G : SimpleGraph V} {u v : V} (h : G.Adj u v) : G.Walk u v :=
Walk.cons h Walk.nil
#align simple_graph.adj.to_walk SimpleGraph.Adj.toWalk
namespace Walk
variable {G}
@[match_pattern]
abbrev nil' (u : V) : G.Walk u u := Walk.nil
#align simple_graph.walk.nil' SimpleGraph.Walk.nil'
@[match_pattern]
abbrev cons' (u v w : V) (h : G.Adj u v) (p : G.Walk v w) : G.Walk u w := Walk.cons h p
#align simple_graph.walk.cons' SimpleGraph.Walk.cons'
protected def copy {u v u' v'} (p : G.Walk u v) (hu : u = u') (hv : v = v') : G.Walk u' v' :=
hu ▸ hv ▸ p
#align simple_graph.walk.copy SimpleGraph.Walk.copy
@[simp]
theorem copy_rfl_rfl {u v} (p : G.Walk u v) : p.copy rfl rfl = p := rfl
#align simple_graph.walk.copy_rfl_rfl SimpleGraph.Walk.copy_rfl_rfl
@[simp]
theorem copy_copy {u v u' v' u'' v''} (p : G.Walk u v)
(hu : u = u') (hv : v = v') (hu' : u' = u'') (hv' : v' = v'') :
(p.copy hu hv).copy hu' hv' = p.copy (hu.trans hu') (hv.trans hv') := by
subst_vars
rfl
#align simple_graph.walk.copy_copy SimpleGraph.Walk.copy_copy
@[simp]
theorem copy_nil {u u'} (hu : u = u') : (Walk.nil : G.Walk u u).copy hu hu = Walk.nil := by
subst_vars
rfl
#align simple_graph.walk.copy_nil SimpleGraph.Walk.copy_nil
theorem copy_cons {u v w u' w'} (h : G.Adj u v) (p : G.Walk v w) (hu : u = u') (hw : w = w') :
(Walk.cons h p).copy hu hw = Walk.cons (hu ▸ h) (p.copy rfl hw) := by
subst_vars
rfl
#align simple_graph.walk.copy_cons SimpleGraph.Walk.copy_cons
@[simp]
theorem cons_copy {u v w v' w'} (h : G.Adj u v) (p : G.Walk v' w') (hv : v' = v) (hw : w' = w) :
Walk.cons h (p.copy hv hw) = (Walk.cons (hv ▸ h) p).copy rfl hw := by
subst_vars
rfl
#align simple_graph.walk.cons_copy SimpleGraph.Walk.cons_copy
theorem exists_eq_cons_of_ne {u v : V} (hne : u ≠ v) :
∀ (p : G.Walk u v), ∃ (w : V) (h : G.Adj u w) (p' : G.Walk w v), p = cons h p'
| nil => (hne rfl).elim
| cons h p' => ⟨_, h, p', rfl⟩
#align simple_graph.walk.exists_eq_cons_of_ne SimpleGraph.Walk.exists_eq_cons_of_ne
def length {u v : V} : G.Walk u v → ℕ
| nil => 0
| cons _ q => q.length.succ
#align simple_graph.walk.length SimpleGraph.Walk.length
@[trans]
def append {u v w : V} : G.Walk u v → G.Walk v w → G.Walk u w
| nil, q => q
| cons h p, q => cons h (p.append q)
#align simple_graph.walk.append SimpleGraph.Walk.append
def concat {u v w : V} (p : G.Walk u v) (h : G.Adj v w) : G.Walk u w := p.append (cons h nil)
#align simple_graph.walk.concat SimpleGraph.Walk.concat
theorem concat_eq_append {u v w : V} (p : G.Walk u v) (h : G.Adj v w) :
p.concat h = p.append (cons h nil) := rfl
#align simple_graph.walk.concat_eq_append SimpleGraph.Walk.concat_eq_append
protected def reverseAux {u v w : V} : G.Walk u v → G.Walk u w → G.Walk v w
| nil, q => q
| cons h p, q => Walk.reverseAux p (cons (G.symm h) q)
#align simple_graph.walk.reverse_aux SimpleGraph.Walk.reverseAux
@[symm]
def reverse {u v : V} (w : G.Walk u v) : G.Walk v u := w.reverseAux nil
#align simple_graph.walk.reverse SimpleGraph.Walk.reverse
def getVert {u v : V} : G.Walk u v → ℕ → V
| nil, _ => u
| cons _ _, 0 => u
| cons _ q, n + 1 => q.getVert n
#align simple_graph.walk.get_vert SimpleGraph.Walk.getVert
@[simp]
theorem getVert_zero {u v} (w : G.Walk u v) : w.getVert 0 = u := by cases w <;> rfl
#align simple_graph.walk.get_vert_zero SimpleGraph.Walk.getVert_zero
theorem getVert_of_length_le {u v} (w : G.Walk u v) {i : ℕ} (hi : w.length ≤ i) :
w.getVert i = v := by
induction w generalizing i with
| nil => rfl
| cons _ _ ih =>
cases i
· cases hi
· exact ih (Nat.succ_le_succ_iff.1 hi)
#align simple_graph.walk.get_vert_of_length_le SimpleGraph.Walk.getVert_of_length_le
@[simp]
theorem getVert_length {u v} (w : G.Walk u v) : w.getVert w.length = v :=
w.getVert_of_length_le rfl.le
#align simple_graph.walk.get_vert_length SimpleGraph.Walk.getVert_length
theorem adj_getVert_succ {u v} (w : G.Walk u v) {i : ℕ} (hi : i < w.length) :
G.Adj (w.getVert i) (w.getVert (i + 1)) := by
induction w generalizing i with
| nil => cases hi
| cons hxy _ ih =>
cases i
· simp [getVert, hxy]
· exact ih (Nat.succ_lt_succ_iff.1 hi)
#align simple_graph.walk.adj_get_vert_succ SimpleGraph.Walk.adj_getVert_succ
@[simp]
theorem cons_append {u v w x : V} (h : G.Adj u v) (p : G.Walk v w) (q : G.Walk w x) :
(cons h p).append q = cons h (p.append q) := rfl
#align simple_graph.walk.cons_append SimpleGraph.Walk.cons_append
@[simp]
theorem cons_nil_append {u v w : V} (h : G.Adj u v) (p : G.Walk v w) :
(cons h nil).append p = cons h p := rfl
#align simple_graph.walk.cons_nil_append SimpleGraph.Walk.cons_nil_append
@[simp]
theorem append_nil {u v : V} (p : G.Walk u v) : p.append nil = p := by
induction p with
| nil => rfl
| cons _ _ ih => rw [cons_append, ih]
#align simple_graph.walk.append_nil SimpleGraph.Walk.append_nil
@[simp]
theorem nil_append {u v : V} (p : G.Walk u v) : nil.append p = p :=
rfl
#align simple_graph.walk.nil_append SimpleGraph.Walk.nil_append
theorem append_assoc {u v w x : V} (p : G.Walk u v) (q : G.Walk v w) (r : G.Walk w x) :
p.append (q.append r) = (p.append q).append r := by
induction p with
| nil => rfl
| cons h p' ih =>
dsimp only [append]
rw [ih]
#align simple_graph.walk.append_assoc SimpleGraph.Walk.append_assoc
@[simp]
theorem append_copy_copy {u v w u' v' w'} (p : G.Walk u v) (q : G.Walk v w)
(hu : u = u') (hv : v = v') (hw : w = w') :
(p.copy hu hv).append (q.copy hv hw) = (p.append q).copy hu hw := by
subst_vars
rfl
#align simple_graph.walk.append_copy_copy SimpleGraph.Walk.append_copy_copy
theorem concat_nil {u v : V} (h : G.Adj u v) : nil.concat h = cons h nil := rfl
#align simple_graph.walk.concat_nil SimpleGraph.Walk.concat_nil
@[simp]
theorem concat_cons {u v w x : V} (h : G.Adj u v) (p : G.Walk v w) (h' : G.Adj w x) :
(cons h p).concat h' = cons h (p.concat h') := rfl
#align simple_graph.walk.concat_cons SimpleGraph.Walk.concat_cons
theorem append_concat {u v w x : V} (p : G.Walk u v) (q : G.Walk v w) (h : G.Adj w x) :
p.append (q.concat h) = (p.append q).concat h := append_assoc _ _ _
#align simple_graph.walk.append_concat SimpleGraph.Walk.append_concat
theorem concat_append {u v w x : V} (p : G.Walk u v) (h : G.Adj v w) (q : G.Walk w x) :
(p.concat h).append q = p.append (cons h q) := by
rw [concat_eq_append, ← append_assoc, cons_nil_append]
#align simple_graph.walk.concat_append SimpleGraph.Walk.concat_append
theorem exists_cons_eq_concat {u v w : V} (h : G.Adj u v) (p : G.Walk v w) :
∃ (x : V) (q : G.Walk u x) (h' : G.Adj x w), cons h p = q.concat h' := by
induction p generalizing u with
| nil => exact ⟨_, nil, h, rfl⟩
| cons h' p ih =>
obtain ⟨y, q, h'', hc⟩ := ih h'
refine ⟨y, cons h q, h'', ?_⟩
rw [concat_cons, hc]
#align simple_graph.walk.exists_cons_eq_concat SimpleGraph.Walk.exists_cons_eq_concat
theorem exists_concat_eq_cons {u v w : V} :
∀ (p : G.Walk u v) (h : G.Adj v w),
∃ (x : V) (h' : G.Adj u x) (q : G.Walk x w), p.concat h = cons h' q
| nil, h => ⟨_, h, nil, rfl⟩
| cons h' p, h => ⟨_, h', Walk.concat p h, concat_cons _ _ _⟩
#align simple_graph.walk.exists_concat_eq_cons SimpleGraph.Walk.exists_concat_eq_cons
@[simp]
theorem reverse_nil {u : V} : (nil : G.Walk u u).reverse = nil := rfl
#align simple_graph.walk.reverse_nil SimpleGraph.Walk.reverse_nil
theorem reverse_singleton {u v : V} (h : G.Adj u v) : (cons h nil).reverse = cons (G.symm h) nil :=
rfl
#align simple_graph.walk.reverse_singleton SimpleGraph.Walk.reverse_singleton
@[simp]
theorem cons_reverseAux {u v w x : V} (p : G.Walk u v) (q : G.Walk w x) (h : G.Adj w u) :
(cons h p).reverseAux q = p.reverseAux (cons (G.symm h) q) := rfl
#align simple_graph.walk.cons_reverse_aux SimpleGraph.Walk.cons_reverseAux
@[simp]
protected theorem append_reverseAux {u v w x : V}
(p : G.Walk u v) (q : G.Walk v w) (r : G.Walk u x) :
(p.append q).reverseAux r = q.reverseAux (p.reverseAux r) := by
induction p with
| nil => rfl
| cons h _ ih => exact ih q (cons (G.symm h) r)
#align simple_graph.walk.append_reverse_aux SimpleGraph.Walk.append_reverseAux
@[simp]
protected theorem reverseAux_append {u v w x : V}
(p : G.Walk u v) (q : G.Walk u w) (r : G.Walk w x) :
(p.reverseAux q).append r = p.reverseAux (q.append r) := by
induction p with
| nil => rfl
| cons h _ ih => simp [ih (cons (G.symm h) q)]
#align simple_graph.walk.reverse_aux_append SimpleGraph.Walk.reverseAux_append
protected theorem reverseAux_eq_reverse_append {u v w : V} (p : G.Walk u v) (q : G.Walk u w) :
p.reverseAux q = p.reverse.append q := by simp [reverse]
#align simple_graph.walk.reverse_aux_eq_reverse_append SimpleGraph.Walk.reverseAux_eq_reverse_append
@[simp]
theorem reverse_cons {u v w : V} (h : G.Adj u v) (p : G.Walk v w) :
(cons h p).reverse = p.reverse.append (cons (G.symm h) nil) := by simp [reverse]
#align simple_graph.walk.reverse_cons SimpleGraph.Walk.reverse_cons
@[simp]
theorem reverse_copy {u v u' v'} (p : G.Walk u v) (hu : u = u') (hv : v = v') :
(p.copy hu hv).reverse = p.reverse.copy hv hu := by
subst_vars
rfl
#align simple_graph.walk.reverse_copy SimpleGraph.Walk.reverse_copy
@[simp]
theorem reverse_append {u v w : V} (p : G.Walk u v) (q : G.Walk v w) :
(p.append q).reverse = q.reverse.append p.reverse := by simp [reverse]
#align simple_graph.walk.reverse_append SimpleGraph.Walk.reverse_append
@[simp]
theorem reverse_concat {u v w : V} (p : G.Walk u v) (h : G.Adj v w) :
(p.concat h).reverse = cons (G.symm h) p.reverse := by simp [concat_eq_append]
#align simple_graph.walk.reverse_concat SimpleGraph.Walk.reverse_concat
@[simp]
theorem reverse_reverse {u v : V} (p : G.Walk u v) : p.reverse.reverse = p := by
induction p with
| nil => rfl
| cons _ _ ih => simp [ih]
#align simple_graph.walk.reverse_reverse SimpleGraph.Walk.reverse_reverse
@[simp]
theorem length_nil {u : V} : (nil : G.Walk u u).length = 0 := rfl
#align simple_graph.walk.length_nil SimpleGraph.Walk.length_nil
@[simp]
theorem length_cons {u v w : V} (h : G.Adj u v) (p : G.Walk v w) :
(cons h p).length = p.length + 1 := rfl
#align simple_graph.walk.length_cons SimpleGraph.Walk.length_cons
@[simp]
theorem length_copy {u v u' v'} (p : G.Walk u v) (hu : u = u') (hv : v = v') :
(p.copy hu hv).length = p.length := by
subst_vars
rfl
#align simple_graph.walk.length_copy SimpleGraph.Walk.length_copy
@[simp]
theorem length_append {u v w : V} (p : G.Walk u v) (q : G.Walk v w) :
(p.append q).length = p.length + q.length := by
induction p with
| nil => simp
| cons _ _ ih => simp [ih, add_comm, add_left_comm, add_assoc]
#align simple_graph.walk.length_append SimpleGraph.Walk.length_append
@[simp]
theorem length_concat {u v w : V} (p : G.Walk u v) (h : G.Adj v w) :
(p.concat h).length = p.length + 1 := length_append _ _
#align simple_graph.walk.length_concat SimpleGraph.Walk.length_concat
@[simp]
protected theorem length_reverseAux {u v w : V} (p : G.Walk u v) (q : G.Walk u w) :
(p.reverseAux q).length = p.length + q.length := by
induction p with
| nil => simp!
| cons _ _ ih => simp [ih, Nat.succ_add, Nat.add_assoc]
#align simple_graph.walk.length_reverse_aux SimpleGraph.Walk.length_reverseAux
@[simp]
theorem length_reverse {u v : V} (p : G.Walk u v) : p.reverse.length = p.length := by simp [reverse]
#align simple_graph.walk.length_reverse SimpleGraph.Walk.length_reverse
theorem eq_of_length_eq_zero {u v : V} : ∀ {p : G.Walk u v}, p.length = 0 → u = v
| nil, _ => rfl
#align simple_graph.walk.eq_of_length_eq_zero SimpleGraph.Walk.eq_of_length_eq_zero
theorem adj_of_length_eq_one {u v : V} : ∀ {p : G.Walk u v}, p.length = 1 → G.Adj u v
| cons h nil, _ => h
@[simp]
theorem exists_length_eq_zero_iff {u v : V} : (∃ p : G.Walk u v, p.length = 0) ↔ u = v := by
constructor
· rintro ⟨p, hp⟩
exact eq_of_length_eq_zero hp
· rintro rfl
exact ⟨nil, rfl⟩
#align simple_graph.walk.exists_length_eq_zero_iff SimpleGraph.Walk.exists_length_eq_zero_iff
@[simp]
theorem length_eq_zero_iff {u : V} {p : G.Walk u u} : p.length = 0 ↔ p = nil := by cases p <;> simp
#align simple_graph.walk.length_eq_zero_iff SimpleGraph.Walk.length_eq_zero_iff
theorem getVert_append {u v w : V} (p : G.Walk u v) (q : G.Walk v w) (i : ℕ) :
(p.append q).getVert i = if i < p.length then p.getVert i else q.getVert (i - p.length) := by
induction p generalizing i with
| nil => simp
| cons h p ih => cases i <;> simp [getVert, ih, Nat.succ_lt_succ_iff]
theorem getVert_reverse {u v : V} (p : G.Walk u v) (i : ℕ) :
p.reverse.getVert i = p.getVert (p.length - i) := by
induction p with
| nil => rfl
| cons h p ih =>
simp only [reverse_cons, getVert_append, length_reverse, ih, length_cons]
split_ifs
next hi =>
rw [Nat.succ_sub hi.le]
simp [getVert]
next hi =>
obtain rfl | hi' := Nat.eq_or_lt_of_not_lt hi
· simp [getVert]
· rw [Nat.eq_add_of_sub_eq (Nat.sub_pos_of_lt hi') rfl, Nat.sub_eq_zero_of_le hi']
simp [getVert]
theorem concat_ne_nil {u v : V} (p : G.Walk u v) (h : G.Adj v u) : p.concat h ≠ nil := by
cases p <;> simp [concat]
#align simple_graph.walk.concat_ne_nil SimpleGraph.Walk.concat_ne_nil
theorem concat_inj {u v v' w : V} {p : G.Walk u v} {h : G.Adj v w} {p' : G.Walk u v'}
{h' : G.Adj v' w} (he : p.concat h = p'.concat h') : ∃ hv : v = v', p.copy rfl hv = p' := by
induction p with
| nil =>
cases p'
· exact ⟨rfl, rfl⟩
· exfalso
simp only [concat_nil, concat_cons, cons.injEq] at he
obtain ⟨rfl, he⟩ := he
simp only [heq_iff_eq] at he
exact concat_ne_nil _ _ he.symm
| cons _ _ ih =>
rw [concat_cons] at he
cases p'
· exfalso
simp only [concat_nil, cons.injEq] at he
obtain ⟨rfl, he⟩ := he
rw [heq_iff_eq] at he
exact concat_ne_nil _ _ he
· rw [concat_cons, cons.injEq] at he
obtain ⟨rfl, he⟩ := he
rw [heq_iff_eq] at he
obtain ⟨rfl, rfl⟩ := ih he
exact ⟨rfl, rfl⟩
#align simple_graph.walk.concat_inj SimpleGraph.Walk.concat_inj
def support {u v : V} : G.Walk u v → List V
| nil => [u]
| cons _ p => u :: p.support
#align simple_graph.walk.support SimpleGraph.Walk.support
def darts {u v : V} : G.Walk u v → List G.Dart
| nil => []
| cons h p => ⟨(u, _), h⟩ :: p.darts
#align simple_graph.walk.darts SimpleGraph.Walk.darts
def edges {u v : V} (p : G.Walk u v) : List (Sym2 V) := p.darts.map Dart.edge
#align simple_graph.walk.edges SimpleGraph.Walk.edges
@[simp]
theorem support_nil {u : V} : (nil : G.Walk u u).support = [u] := rfl
#align simple_graph.walk.support_nil SimpleGraph.Walk.support_nil
@[simp]
theorem support_cons {u v w : V} (h : G.Adj u v) (p : G.Walk v w) :
(cons h p).support = u :: p.support := rfl
#align simple_graph.walk.support_cons SimpleGraph.Walk.support_cons
@[simp]
theorem support_concat {u v w : V} (p : G.Walk u v) (h : G.Adj v w) :
(p.concat h).support = p.support.concat w := by
induction p <;> simp [*, concat_nil]
#align simple_graph.walk.support_concat SimpleGraph.Walk.support_concat
@[simp]
theorem support_copy {u v u' v'} (p : G.Walk u v) (hu : u = u') (hv : v = v') :
(p.copy hu hv).support = p.support := by
subst_vars
rfl
#align simple_graph.walk.support_copy SimpleGraph.Walk.support_copy
theorem support_append {u v w : V} (p : G.Walk u v) (p' : G.Walk v w) :
(p.append p').support = p.support ++ p'.support.tail := by
induction p <;> cases p' <;> simp [*]
#align simple_graph.walk.support_append SimpleGraph.Walk.support_append
@[simp]
theorem support_reverse {u v : V} (p : G.Walk u v) : p.reverse.support = p.support.reverse := by
induction p <;> simp [support_append, *]
#align simple_graph.walk.support_reverse SimpleGraph.Walk.support_reverse
@[simp]
theorem support_ne_nil {u v : V} (p : G.Walk u v) : p.support ≠ [] := by cases p <;> simp
#align simple_graph.walk.support_ne_nil SimpleGraph.Walk.support_ne_nil
theorem tail_support_append {u v w : V} (p : G.Walk u v) (p' : G.Walk v w) :
(p.append p').support.tail = p.support.tail ++ p'.support.tail := by
rw [support_append, List.tail_append_of_ne_nil _ _ (support_ne_nil _)]
#align simple_graph.walk.tail_support_append SimpleGraph.Walk.tail_support_append
theorem support_eq_cons {u v : V} (p : G.Walk u v) : p.support = u :: p.support.tail := by
cases p <;> simp
#align simple_graph.walk.support_eq_cons SimpleGraph.Walk.support_eq_cons
@[simp]
theorem start_mem_support {u v : V} (p : G.Walk u v) : u ∈ p.support := by cases p <;> simp
#align simple_graph.walk.start_mem_support SimpleGraph.Walk.start_mem_support
@[simp]
theorem end_mem_support {u v : V} (p : G.Walk u v) : v ∈ p.support := by induction p <;> simp [*]
#align simple_graph.walk.end_mem_support SimpleGraph.Walk.end_mem_support
@[simp]
theorem support_nonempty {u v : V} (p : G.Walk u v) : { w | w ∈ p.support }.Nonempty :=
⟨u, by simp⟩
#align simple_graph.walk.support_nonempty SimpleGraph.Walk.support_nonempty
theorem mem_support_iff {u v w : V} (p : G.Walk u v) :
w ∈ p.support ↔ w = u ∨ w ∈ p.support.tail := by cases p <;> simp
#align simple_graph.walk.mem_support_iff SimpleGraph.Walk.mem_support_iff
theorem mem_support_nil_iff {u v : V} : u ∈ (nil : G.Walk v v).support ↔ u = v := by simp
#align simple_graph.walk.mem_support_nil_iff SimpleGraph.Walk.mem_support_nil_iff
@[simp]
theorem mem_tail_support_append_iff {t u v w : V} (p : G.Walk u v) (p' : G.Walk v w) :
t ∈ (p.append p').support.tail ↔ t ∈ p.support.tail ∨ t ∈ p'.support.tail := by
rw [tail_support_append, List.mem_append]
#align simple_graph.walk.mem_tail_support_append_iff SimpleGraph.Walk.mem_tail_support_append_iff
@[simp]
theorem end_mem_tail_support_of_ne {u v : V} (h : u ≠ v) (p : G.Walk u v) : v ∈ p.support.tail := by
obtain ⟨_, _, _, rfl⟩ := exists_eq_cons_of_ne h p
simp
#align simple_graph.walk.end_mem_tail_support_of_ne SimpleGraph.Walk.end_mem_tail_support_of_ne
@[simp, nolint unusedHavesSuffices]
theorem mem_support_append_iff {t u v w : V} (p : G.Walk u v) (p' : G.Walk v w) :
t ∈ (p.append p').support ↔ t ∈ p.support ∨ t ∈ p'.support := by
simp only [mem_support_iff, mem_tail_support_append_iff]
obtain rfl | h := eq_or_ne t v <;> obtain rfl | h' := eq_or_ne t u <;>
-- this `have` triggers the unusedHavesSuffices linter:
(try have := h'.symm) <;> simp [*]
#align simple_graph.walk.mem_support_append_iff SimpleGraph.Walk.mem_support_append_iff
@[simp]
theorem subset_support_append_left {V : Type u} {G : SimpleGraph V} {u v w : V}
(p : G.Walk u v) (q : G.Walk v w) : p.support ⊆ (p.append q).support := by
simp only [Walk.support_append, List.subset_append_left]
#align simple_graph.walk.subset_support_append_left SimpleGraph.Walk.subset_support_append_left
@[simp]
theorem subset_support_append_right {V : Type u} {G : SimpleGraph V} {u v w : V}
(p : G.Walk u v) (q : G.Walk v w) : q.support ⊆ (p.append q).support := by
intro h
simp (config := { contextual := true }) only [mem_support_append_iff, or_true_iff, imp_true_iff]
#align simple_graph.walk.subset_support_append_right SimpleGraph.Walk.subset_support_append_right
theorem coe_support {u v : V} (p : G.Walk u v) :
(p.support : Multiset V) = {u} + p.support.tail := by cases p <;> rfl
#align simple_graph.walk.coe_support SimpleGraph.Walk.coe_support
theorem coe_support_append {u v w : V} (p : G.Walk u v) (p' : G.Walk v w) :
((p.append p').support : Multiset V) = {u} + p.support.tail + p'.support.tail := by
rw [support_append, ← Multiset.coe_add, coe_support]
#align simple_graph.walk.coe_support_append SimpleGraph.Walk.coe_support_append
| Mathlib/Combinatorics/SimpleGraph/Connectivity.lean | 654 | 659 | theorem coe_support_append' [DecidableEq V] {u v w : V} (p : G.Walk u v) (p' : G.Walk v w) :
((p.append p').support : Multiset V) = p.support + p'.support - {v} := by |
rw [support_append, ← Multiset.coe_add]
simp only [coe_support]
rw [add_comm ({v} : Multiset V)]
simp only [← add_assoc, add_tsub_cancel_right]
|
import Mathlib.Algebra.Star.Center
import Mathlib.Algebra.Star.StarAlgHom
import Mathlib.Algebra.Algebra.Subalgebra.Basic
import Mathlib.Algebra.Star.Pointwise
import Mathlib.Algebra.Star.Module
import Mathlib.RingTheory.Adjoin.Basic
#align_import algebra.star.subalgebra from "leanprover-community/mathlib"@"160ef3e338a2a4f21a280e4c152d4016156e516d"
universe u v
structure StarSubalgebra (R : Type u) (A : Type v) [CommSemiring R] [StarRing R] [Semiring A]
[StarRing A] [Algebra R A] [StarModule R A] extends Subalgebra R A : Type v where
star_mem' {a} : a ∈ carrier → star a ∈ carrier
#align star_subalgebra StarSubalgebra
namespace StarSubalgebra
add_decl_doc StarSubalgebra.toSubalgebra
variable {F R A B C : Type*} [CommSemiring R] [StarRing R]
variable [Semiring A] [StarRing A] [Algebra R A] [StarModule R A]
variable [Semiring B] [StarRing B] [Algebra R B] [StarModule R B]
variable [Semiring C] [StarRing C] [Algebra R C] [StarModule R C]
instance setLike : SetLike (StarSubalgebra R A) A where
coe S := S.carrier
coe_injective' p q h := by obtain ⟨⟨⟨⟨⟨_, _⟩, _⟩, _⟩, _⟩, _⟩ := p; cases q; congr
instance starMemClass : StarMemClass (StarSubalgebra R A) A where
star_mem {s} := s.star_mem'
instance subsemiringClass : SubsemiringClass (StarSubalgebra R A) A where
add_mem {s} := s.add_mem'
mul_mem {s} := s.mul_mem'
one_mem {s} := s.one_mem'
zero_mem {s} := s.zero_mem'
instance smulMemClass : SMulMemClass (StarSubalgebra R A) R A where
smul_mem {s} r a (ha : a ∈ s.toSubalgebra) :=
(SMulMemClass.smul_mem r ha : r • a ∈ s.toSubalgebra)
instance subringClass {R A} [CommRing R] [StarRing R] [Ring A] [StarRing A] [Algebra R A]
[StarModule R A] : SubringClass (StarSubalgebra R A) A where
neg_mem {s a} ha := show -a ∈ s.toSubalgebra from neg_mem ha
-- this uses the `Star` instance `s` inherits from `StarMemClass (StarSubalgebra R A) A`
instance starRing (s : StarSubalgebra R A) : StarRing s :=
{ StarMemClass.instStar s with
star_involutive := fun r => Subtype.ext (star_star (r : A))
star_mul := fun r₁ r₂ => Subtype.ext (star_mul (r₁ : A) (r₂ : A))
star_add := fun r₁ r₂ => Subtype.ext (star_add (r₁ : A) (r₂ : A)) }
instance algebra (s : StarSubalgebra R A) : Algebra R s :=
s.toSubalgebra.algebra'
instance starModule (s : StarSubalgebra R A) : StarModule R s where
star_smul r a := Subtype.ext (star_smul r (a : A))
@[simp, nolint simpNF] -- porting note (#10618): `simpNF` says `simp` can prove this, but it can't
theorem mem_carrier {s : StarSubalgebra R A} {x : A} : x ∈ s.carrier ↔ x ∈ s :=
Iff.rfl
#align star_subalgebra.mem_carrier StarSubalgebra.mem_carrier
@[ext]
theorem ext {S T : StarSubalgebra R A} (h : ∀ x : A, x ∈ S ↔ x ∈ T) : S = T :=
SetLike.ext h
#align star_subalgebra.ext StarSubalgebra.ext
@[simp]
lemma coe_mk (S : Subalgebra R A) (h) : ((⟨S, h⟩ : StarSubalgebra R A) : Set A) = S := rfl
@[simp]
theorem mem_toSubalgebra {S : StarSubalgebra R A} {x} : x ∈ S.toSubalgebra ↔ x ∈ S :=
Iff.rfl
#align star_subalgebra.mem_to_subalgebra StarSubalgebra.mem_toSubalgebra
@[simp]
theorem coe_toSubalgebra (S : StarSubalgebra R A) : (S.toSubalgebra : Set A) = S :=
rfl
#align star_subalgebra.coe_to_subalgebra StarSubalgebra.coe_toSubalgebra
theorem toSubalgebra_injective :
Function.Injective (toSubalgebra : StarSubalgebra R A → Subalgebra R A) := fun S T h =>
ext fun x => by rw [← mem_toSubalgebra, ← mem_toSubalgebra, h]
#align star_subalgebra.to_subalgebra_injective StarSubalgebra.toSubalgebra_injective
theorem toSubalgebra_inj {S U : StarSubalgebra R A} : S.toSubalgebra = U.toSubalgebra ↔ S = U :=
toSubalgebra_injective.eq_iff
#align star_subalgebra.to_subalgebra_inj StarSubalgebra.toSubalgebra_inj
theorem toSubalgebra_le_iff {S₁ S₂ : StarSubalgebra R A} :
S₁.toSubalgebra ≤ S₂.toSubalgebra ↔ S₁ ≤ S₂ :=
Iff.rfl
#align star_subalgebra.to_subalgebra_le_iff StarSubalgebra.toSubalgebra_le_iff
protected def copy (S : StarSubalgebra R A) (s : Set A) (hs : s = ↑S) : StarSubalgebra R A where
toSubalgebra := Subalgebra.copy S.toSubalgebra s hs
star_mem' := @fun a ha => hs ▸ (S.star_mem' (by simpa [hs] using ha) : star a ∈ (S : Set A))
-- Porting note: the old proof kept crashing Lean
#align star_subalgebra.copy StarSubalgebra.copy
@[simp]
theorem coe_copy (S : StarSubalgebra R A) (s : Set A) (hs : s = ↑S) : (S.copy s hs : Set A) = s :=
rfl
#align star_subalgebra.coe_copy StarSubalgebra.coe_copy
theorem copy_eq (S : StarSubalgebra R A) (s : Set A) (hs : s = ↑S) : S.copy s hs = S :=
SetLike.coe_injective hs
#align star_subalgebra.copy_eq StarSubalgebra.copy_eq
variable (S : StarSubalgebra R A)
theorem algebraMap_mem (r : R) : algebraMap R A r ∈ S :=
S.algebraMap_mem' r
#align star_subalgebra.algebra_map_mem StarSubalgebra.algebraMap_mem
theorem rangeS_le : (algebraMap R A).rangeS ≤ S.toSubalgebra.toSubsemiring := fun _x ⟨r, hr⟩ =>
hr ▸ S.algebraMap_mem r
#align star_subalgebra.srange_le StarSubalgebra.rangeS_le
theorem range_subset : Set.range (algebraMap R A) ⊆ S := fun _x ⟨r, hr⟩ => hr ▸ S.algebraMap_mem r
#align star_subalgebra.range_subset StarSubalgebra.range_subset
theorem range_le : Set.range (algebraMap R A) ≤ S :=
S.range_subset
#align star_subalgebra.range_le StarSubalgebra.range_le
protected theorem smul_mem {x : A} (hx : x ∈ S) (r : R) : r • x ∈ S :=
(Algebra.smul_def r x).symm ▸ mul_mem (S.algebraMap_mem r) hx
#align star_subalgebra.smul_mem StarSubalgebra.smul_mem
def subtype : S →⋆ₐ[R] A where
toFun := ((↑) : S → A)
map_one' := rfl
map_mul' _ _ := rfl
map_zero' := rfl
map_add' _ _ := rfl
commutes' _ := rfl
map_star' _ := rfl
#align star_subalgebra.subtype StarSubalgebra.subtype
@[simp]
theorem coe_subtype : (S.subtype : S → A) = Subtype.val :=
rfl
#align star_subalgebra.coe_subtype StarSubalgebra.coe_subtype
theorem subtype_apply (x : S) : S.subtype x = (x : A) :=
rfl
#align star_subalgebra.subtype_apply StarSubalgebra.subtype_apply
@[simp]
theorem toSubalgebra_subtype : S.toSubalgebra.val = S.subtype.toAlgHom :=
rfl
#align star_subalgebra.to_subalgebra_subtype StarSubalgebra.toSubalgebra_subtype
@[simps]
def inclusion {S₁ S₂ : StarSubalgebra R A} (h : S₁ ≤ S₂) : S₁ →⋆ₐ[R] S₂ where
toFun := Subtype.map id h
map_one' := rfl
map_mul' _ _ := rfl
map_zero' := rfl
map_add' _ _ := rfl
commutes' _ := rfl
map_star' _ := rfl
#align star_subalgebra.inclusion StarSubalgebra.inclusion
theorem inclusion_injective {S₁ S₂ : StarSubalgebra R A} (h : S₁ ≤ S₂) :
Function.Injective <| inclusion h :=
Set.inclusion_injective h
#align star_subalgebra.inclusion_injective StarSubalgebra.inclusion_injective
@[simp]
theorem subtype_comp_inclusion {S₁ S₂ : StarSubalgebra R A} (h : S₁ ≤ S₂) :
S₂.subtype.comp (inclusion h) = S₁.subtype :=
rfl
#align star_subalgebra.subtype_comp_inclusion StarSubalgebra.subtype_comp_inclusion
namespace StarAlgebra
open StarSubalgebra
variable {F R A B : Type*} [CommSemiring R] [StarRing R]
variable [Semiring A] [Algebra R A] [StarRing A] [StarModule R A]
variable [Semiring B] [Algebra R B] [StarRing B] [StarModule R B]
variable (R)
@[simps!]
def adjoin (s : Set A) : StarSubalgebra R A :=
{ Algebra.adjoin R (s ∪ star s) with
star_mem' := fun hx => by
rwa [Subalgebra.mem_carrier, ← Subalgebra.mem_star_iff, Subalgebra.star_adjoin_comm,
Set.union_star, star_star, Set.union_comm] }
#align star_subalgebra.adjoin StarAlgebra.adjoin
theorem adjoin_eq_starClosure_adjoin (s : Set A) : adjoin R s = (Algebra.adjoin R s).starClosure :=
toSubalgebra_injective <|
show Algebra.adjoin R (s ∪ star s) = Algebra.adjoin R s ⊔ star (Algebra.adjoin R s) from
(Subalgebra.star_adjoin_comm R s).symm ▸ Algebra.adjoin_union s (star s)
#align star_subalgebra.adjoin_eq_star_closure_adjoin StarAlgebra.adjoin_eq_starClosure_adjoin
theorem adjoin_toSubalgebra (s : Set A) :
(adjoin R s).toSubalgebra = Algebra.adjoin R (s ∪ star s) :=
rfl
#align star_subalgebra.adjoin_to_subalgebra StarAlgebra.adjoin_toSubalgebra
@[aesop safe 20 apply (rule_sets := [SetLike])]
theorem subset_adjoin (s : Set A) : s ⊆ adjoin R s :=
Set.subset_union_left.trans Algebra.subset_adjoin
#align star_subalgebra.subset_adjoin StarAlgebra.subset_adjoin
theorem star_subset_adjoin (s : Set A) : star s ⊆ adjoin R s :=
Set.subset_union_right.trans Algebra.subset_adjoin
#align star_subalgebra.star_subset_adjoin StarAlgebra.star_subset_adjoin
theorem self_mem_adjoin_singleton (x : A) : x ∈ adjoin R ({x} : Set A) :=
Algebra.subset_adjoin <| Set.mem_union_left _ (Set.mem_singleton x)
#align star_subalgebra.self_mem_adjoin_singleton StarAlgebra.self_mem_adjoin_singleton
theorem star_self_mem_adjoin_singleton (x : A) : star x ∈ adjoin R ({x} : Set A) :=
star_mem <| self_mem_adjoin_singleton R x
#align star_subalgebra.star_self_mem_adjoin_singleton StarAlgebra.star_self_mem_adjoin_singleton
variable {R}
protected theorem gc : GaloisConnection (adjoin R : Set A → StarSubalgebra R A) (↑) := by
intro s S
rw [← toSubalgebra_le_iff, adjoin_toSubalgebra, Algebra.adjoin_le_iff, coe_toSubalgebra]
exact
⟨fun h => Set.subset_union_left.trans h, fun h =>
Set.union_subset h fun x hx => star_star x ▸ star_mem (show star x ∈ S from h hx)⟩
#align star_subalgebra.gc StarAlgebra.gc
protected def gi : GaloisInsertion (adjoin R : Set A → StarSubalgebra R A) (↑) where
choice s hs := (adjoin R s).copy s <| le_antisymm (StarAlgebra.gc.le_u_l s) hs
gc := StarAlgebra.gc
le_l_u S := (StarAlgebra.gc (S : Set A) (adjoin R S)).1 <| le_rfl
choice_eq _ _ := StarSubalgebra.copy_eq _ _ _
#align star_subalgebra.gi StarAlgebra.gi
theorem adjoin_le {S : StarSubalgebra R A} {s : Set A} (hs : s ⊆ S) : adjoin R s ≤ S :=
StarAlgebra.gc.l_le hs
#align star_subalgebra.adjoin_le StarAlgebra.adjoin_le
theorem adjoin_le_iff {S : StarSubalgebra R A} {s : Set A} : adjoin R s ≤ S ↔ s ⊆ S :=
StarAlgebra.gc _ _
#align star_subalgebra.adjoin_le_iff StarAlgebra.adjoin_le_iff
lemma adjoin_eq (S : StarSubalgebra R A) : adjoin R (S : Set A) = S :=
le_antisymm (adjoin_le le_rfl) (subset_adjoin R (S : Set A))
open Submodule in
lemma adjoin_eq_span (s : Set A) :
Subalgebra.toSubmodule (adjoin R s).toSubalgebra = span R (Submonoid.closure (s ∪ star s)) := by
rw [adjoin_toSubalgebra, Algebra.adjoin_eq_span]
theorem _root_.Subalgebra.starClosure_eq_adjoin (S : Subalgebra R A) :
S.starClosure = adjoin R (S : Set A) :=
le_antisymm (Subalgebra.starClosure_le_iff.2 <| subset_adjoin R (S : Set A))
(adjoin_le (le_sup_left : S ≤ S ⊔ star S))
#align subalgebra.star_closure_eq_adjoin Subalgebra.starClosure_eq_adjoin
@[elab_as_elim]
theorem adjoin_induction {s : Set A} {p : A → Prop} {a : A} (h : a ∈ adjoin R s)
(mem : ∀ x : A, x ∈ s → p x) (algebraMap : ∀ r : R, p (algebraMap R A r))
(add : ∀ x y : A, p x → p y → p (x + y)) (mul : ∀ x y : A, p x → p y → p (x * y))
(star : ∀ x : A, p x → p (star x)) : p a :=
Algebra.adjoin_induction h
(fun x hx => hx.elim (fun hx => mem x hx) fun hx => star_star x ▸ star _ (mem _ hx))
algebraMap add mul
#align star_subalgebra.adjoin_induction StarAlgebra.adjoin_induction
@[elab_as_elim]
| Mathlib/Algebra/Star/Subalgebra.lean | 519 | 543 | theorem adjoin_induction₂ {s : Set A} {p : A → A → Prop} {a b : A} (ha : a ∈ adjoin R s)
(hb : b ∈ adjoin R s) (Hs : ∀ x : A, x ∈ s → ∀ y : A, y ∈ s → p x y)
(Halg : ∀ r₁ r₂ : R, p (algebraMap R A r₁) (algebraMap R A r₂))
(Halg_left : ∀ (r : R) (x : A), x ∈ s → p (algebraMap R A r) x)
(Halg_right : ∀ (r : R) (x : A), x ∈ s → p x (algebraMap R A r))
(Hadd_left : ∀ x₁ x₂ y : A, p x₁ y → p x₂ y → p (x₁ + x₂) y)
(Hadd_right : ∀ x y₁ y₂ : A, p x y₁ → p x y₂ → p x (y₁ + y₂))
(Hmul_left : ∀ x₁ x₂ y : A, p x₁ y → p x₂ y → p (x₁ * x₂) y)
(Hmul_right : ∀ x y₁ y₂ : A, p x y₁ → p x y₂ → p x (y₁ * y₂))
(Hstar : ∀ x y : A, p x y → p (star x) (star y)) (Hstar_left : ∀ x y : A, p x y → p (star x) y)
(Hstar_right : ∀ x y : A, p x y → p x (star y)) : p a b := by |
refine
Algebra.adjoin_induction₂ ha hb (fun x hx y hy => ?_) Halg (fun r x hx => ?_) (fun r x hx => ?_)
Hadd_left Hadd_right Hmul_left Hmul_right
· cases' hx with hx hx <;> cases' hy with hy hy
· exact Hs x hx y hy
· exact star_star y ▸ Hstar_right _ _ (Hs _ hx _ hy)
· exact star_star x ▸ Hstar_left _ _ (Hs _ hx _ hy)
· exact star_star x ▸ star_star y ▸ Hstar _ _ (Hs _ hx _ hy)
· cases' hx with hx hx
· exact Halg_left _ _ hx
· exact star_star x ▸ Hstar_right _ _ (Halg_left r _ hx)
· cases' hx with hx hx
· exact Halg_right _ _ hx
· exact star_star x ▸ Hstar_left _ _ (Halg_right r _ hx)
|
import Mathlib.Init.ZeroOne
import Mathlib.Data.Set.Defs
import Mathlib.Order.Basic
import Mathlib.Order.SymmDiff
import Mathlib.Tactic.Tauto
import Mathlib.Tactic.ByContra
import Mathlib.Util.Delaborators
#align_import data.set.basic from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29"
open Function
universe u v w x
namespace Set
variable {α : Type u} {s t : Set α}
instance instBooleanAlgebraSet : BooleanAlgebra (Set α) :=
{ (inferInstance : BooleanAlgebra (α → Prop)) with
sup := (· ∪ ·),
le := (· ≤ ·),
lt := fun s t => s ⊆ t ∧ ¬t ⊆ s,
inf := (· ∩ ·),
bot := ∅,
compl := (·ᶜ),
top := univ,
sdiff := (· \ ·) }
instance : HasSSubset (Set α) :=
⟨(· < ·)⟩
@[simp]
theorem top_eq_univ : (⊤ : Set α) = univ :=
rfl
#align set.top_eq_univ Set.top_eq_univ
@[simp]
theorem bot_eq_empty : (⊥ : Set α) = ∅ :=
rfl
#align set.bot_eq_empty Set.bot_eq_empty
@[simp]
theorem sup_eq_union : ((· ⊔ ·) : Set α → Set α → Set α) = (· ∪ ·) :=
rfl
#align set.sup_eq_union Set.sup_eq_union
@[simp]
theorem inf_eq_inter : ((· ⊓ ·) : Set α → Set α → Set α) = (· ∩ ·) :=
rfl
#align set.inf_eq_inter Set.inf_eq_inter
@[simp]
theorem le_eq_subset : ((· ≤ ·) : Set α → Set α → Prop) = (· ⊆ ·) :=
rfl
#align set.le_eq_subset Set.le_eq_subset
@[simp]
theorem lt_eq_ssubset : ((· < ·) : Set α → Set α → Prop) = (· ⊂ ·) :=
rfl
#align set.lt_eq_ssubset Set.lt_eq_ssubset
theorem le_iff_subset : s ≤ t ↔ s ⊆ t :=
Iff.rfl
#align set.le_iff_subset Set.le_iff_subset
theorem lt_iff_ssubset : s < t ↔ s ⊂ t :=
Iff.rfl
#align set.lt_iff_ssubset Set.lt_iff_ssubset
alias ⟨_root_.LE.le.subset, _root_.HasSubset.Subset.le⟩ := le_iff_subset
#align has_subset.subset.le HasSubset.Subset.le
alias ⟨_root_.LT.lt.ssubset, _root_.HasSSubset.SSubset.lt⟩ := lt_iff_ssubset
#align has_ssubset.ssubset.lt HasSSubset.SSubset.lt
instance PiSetCoe.canLift (ι : Type u) (α : ι → Type v) [∀ i, Nonempty (α i)] (s : Set ι) :
CanLift (∀ i : s, α i) (∀ i, α i) (fun f i => f i) fun _ => True :=
PiSubtype.canLift ι α s
#align set.pi_set_coe.can_lift Set.PiSetCoe.canLift
instance PiSetCoe.canLift' (ι : Type u) (α : Type v) [Nonempty α] (s : Set ι) :
CanLift (s → α) (ι → α) (fun f i => f i) fun _ => True :=
PiSetCoe.canLift ι (fun _ => α) s
#align set.pi_set_coe.can_lift' Set.PiSetCoe.canLift'
end Set
theorem Subtype.mem {α : Type*} {s : Set α} (p : s) : (p : α) ∈ s :=
p.prop
#align subtype.mem Subtype.mem
theorem Eq.subset {α} {s t : Set α} : s = t → s ⊆ t :=
fun h₁ _ h₂ => by rw [← h₁]; exact h₂
#align eq.subset Eq.subset
namespace Set
variable {α : Type u} {β : Type v} {γ : Type w} {ι : Sort x} {a b : α} {s s₁ s₂ t t₁ t₂ u : Set α}
instance : Inhabited (Set α) :=
⟨∅⟩
theorem ext_iff {s t : Set α} : s = t ↔ ∀ x, x ∈ s ↔ x ∈ t :=
⟨fun h x => by rw [h], ext⟩
#align set.ext_iff Set.ext_iff
@[trans]
theorem mem_of_mem_of_subset {x : α} {s t : Set α} (hx : x ∈ s) (h : s ⊆ t) : x ∈ t :=
h hx
#align set.mem_of_mem_of_subset Set.mem_of_mem_of_subset
theorem forall_in_swap {p : α → β → Prop} : (∀ a ∈ s, ∀ (b), p a b) ↔ ∀ (b), ∀ a ∈ s, p a b := by
tauto
#align set.forall_in_swap Set.forall_in_swap
theorem mem_setOf {a : α} {p : α → Prop} : a ∈ { x | p x } ↔ p a :=
Iff.rfl
#align set.mem_set_of Set.mem_setOf
theorem _root_.Membership.mem.out {p : α → Prop} {a : α} (h : a ∈ { x | p x }) : p a :=
h
#align has_mem.mem.out Membership.mem.out
theorem nmem_setOf_iff {a : α} {p : α → Prop} : a ∉ { x | p x } ↔ ¬p a :=
Iff.rfl
#align set.nmem_set_of_iff Set.nmem_setOf_iff
@[simp]
theorem setOf_mem_eq {s : Set α} : { x | x ∈ s } = s :=
rfl
#align set.set_of_mem_eq Set.setOf_mem_eq
theorem setOf_set {s : Set α} : setOf s = s :=
rfl
#align set.set_of_set Set.setOf_set
theorem setOf_app_iff {p : α → Prop} {x : α} : { x | p x } x ↔ p x :=
Iff.rfl
#align set.set_of_app_iff Set.setOf_app_iff
theorem mem_def {a : α} {s : Set α} : a ∈ s ↔ s a :=
Iff.rfl
#align set.mem_def Set.mem_def
theorem setOf_bijective : Bijective (setOf : (α → Prop) → Set α) :=
bijective_id
#align set.set_of_bijective Set.setOf_bijective
theorem subset_setOf {p : α → Prop} {s : Set α} : s ⊆ setOf p ↔ ∀ x, x ∈ s → p x :=
Iff.rfl
theorem setOf_subset {p : α → Prop} {s : Set α} : setOf p ⊆ s ↔ ∀ x, p x → x ∈ s :=
Iff.rfl
@[simp]
theorem setOf_subset_setOf {p q : α → Prop} : { a | p a } ⊆ { a | q a } ↔ ∀ a, p a → q a :=
Iff.rfl
#align set.set_of_subset_set_of Set.setOf_subset_setOf
theorem setOf_and {p q : α → Prop} : { a | p a ∧ q a } = { a | p a } ∩ { a | q a } :=
rfl
#align set.set_of_and Set.setOf_and
theorem setOf_or {p q : α → Prop} : { a | p a ∨ q a } = { a | p a } ∪ { a | q a } :=
rfl
#align set.set_of_or Set.setOf_or
instance : IsRefl (Set α) (· ⊆ ·) :=
show IsRefl (Set α) (· ≤ ·) by infer_instance
instance : IsTrans (Set α) (· ⊆ ·) :=
show IsTrans (Set α) (· ≤ ·) by infer_instance
instance : Trans ((· ⊆ ·) : Set α → Set α → Prop) (· ⊆ ·) (· ⊆ ·) :=
show Trans (· ≤ ·) (· ≤ ·) (· ≤ ·) by infer_instance
instance : IsAntisymm (Set α) (· ⊆ ·) :=
show IsAntisymm (Set α) (· ≤ ·) by infer_instance
instance : IsIrrefl (Set α) (· ⊂ ·) :=
show IsIrrefl (Set α) (· < ·) by infer_instance
instance : IsTrans (Set α) (· ⊂ ·) :=
show IsTrans (Set α) (· < ·) by infer_instance
instance : Trans ((· ⊂ ·) : Set α → Set α → Prop) (· ⊂ ·) (· ⊂ ·) :=
show Trans (· < ·) (· < ·) (· < ·) by infer_instance
instance : Trans ((· ⊂ ·) : Set α → Set α → Prop) (· ⊆ ·) (· ⊂ ·) :=
show Trans (· < ·) (· ≤ ·) (· < ·) by infer_instance
instance : Trans ((· ⊆ ·) : Set α → Set α → Prop) (· ⊂ ·) (· ⊂ ·) :=
show Trans (· ≤ ·) (· < ·) (· < ·) by infer_instance
instance : IsAsymm (Set α) (· ⊂ ·) :=
show IsAsymm (Set α) (· < ·) by infer_instance
instance : IsNonstrictStrictOrder (Set α) (· ⊆ ·) (· ⊂ ·) :=
⟨fun _ _ => Iff.rfl⟩
-- TODO(Jeremy): write a tactic to unfold specific instances of generic notation?
theorem subset_def : (s ⊆ t) = ∀ x, x ∈ s → x ∈ t :=
rfl
#align set.subset_def Set.subset_def
theorem ssubset_def : (s ⊂ t) = (s ⊆ t ∧ ¬t ⊆ s) :=
rfl
#align set.ssubset_def Set.ssubset_def
@[refl]
theorem Subset.refl (a : Set α) : a ⊆ a := fun _ => id
#align set.subset.refl Set.Subset.refl
theorem Subset.rfl {s : Set α} : s ⊆ s :=
Subset.refl s
#align set.subset.rfl Set.Subset.rfl
@[trans]
theorem Subset.trans {a b c : Set α} (ab : a ⊆ b) (bc : b ⊆ c) : a ⊆ c := fun _ h => bc <| ab h
#align set.subset.trans Set.Subset.trans
@[trans]
theorem mem_of_eq_of_mem {x y : α} {s : Set α} (hx : x = y) (h : y ∈ s) : x ∈ s :=
hx.symm ▸ h
#align set.mem_of_eq_of_mem Set.mem_of_eq_of_mem
theorem Subset.antisymm {a b : Set α} (h₁ : a ⊆ b) (h₂ : b ⊆ a) : a = b :=
Set.ext fun _ => ⟨@h₁ _, @h₂ _⟩
#align set.subset.antisymm Set.Subset.antisymm
theorem Subset.antisymm_iff {a b : Set α} : a = b ↔ a ⊆ b ∧ b ⊆ a :=
⟨fun e => ⟨e.subset, e.symm.subset⟩, fun ⟨h₁, h₂⟩ => Subset.antisymm h₁ h₂⟩
#align set.subset.antisymm_iff Set.Subset.antisymm_iff
-- an alternative name
theorem eq_of_subset_of_subset {a b : Set α} : a ⊆ b → b ⊆ a → a = b :=
Subset.antisymm
#align set.eq_of_subset_of_subset Set.eq_of_subset_of_subset
theorem mem_of_subset_of_mem {s₁ s₂ : Set α} {a : α} (h : s₁ ⊆ s₂) : a ∈ s₁ → a ∈ s₂ :=
@h _
#align set.mem_of_subset_of_mem Set.mem_of_subset_of_mem
theorem not_mem_subset (h : s ⊆ t) : a ∉ t → a ∉ s :=
mt <| mem_of_subset_of_mem h
#align set.not_mem_subset Set.not_mem_subset
theorem not_subset : ¬s ⊆ t ↔ ∃ a ∈ s, a ∉ t := by
simp only [subset_def, not_forall, exists_prop]
#align set.not_subset Set.not_subset
lemma eq_of_forall_subset_iff (h : ∀ u, s ⊆ u ↔ t ⊆ u) : s = t := eq_of_forall_ge_iff h
protected theorem eq_or_ssubset_of_subset (h : s ⊆ t) : s = t ∨ s ⊂ t :=
eq_or_lt_of_le h
#align set.eq_or_ssubset_of_subset Set.eq_or_ssubset_of_subset
theorem exists_of_ssubset {s t : Set α} (h : s ⊂ t) : ∃ x ∈ t, x ∉ s :=
not_subset.1 h.2
#align set.exists_of_ssubset Set.exists_of_ssubset
protected theorem ssubset_iff_subset_ne {s t : Set α} : s ⊂ t ↔ s ⊆ t ∧ s ≠ t :=
@lt_iff_le_and_ne (Set α) _ s t
#align set.ssubset_iff_subset_ne Set.ssubset_iff_subset_ne
theorem ssubset_iff_of_subset {s t : Set α} (h : s ⊆ t) : s ⊂ t ↔ ∃ x ∈ t, x ∉ s :=
⟨exists_of_ssubset, fun ⟨_, hxt, hxs⟩ => ⟨h, fun h => hxs <| h hxt⟩⟩
#align set.ssubset_iff_of_subset Set.ssubset_iff_of_subset
protected theorem ssubset_of_ssubset_of_subset {s₁ s₂ s₃ : Set α} (hs₁s₂ : s₁ ⊂ s₂)
(hs₂s₃ : s₂ ⊆ s₃) : s₁ ⊂ s₃ :=
⟨Subset.trans hs₁s₂.1 hs₂s₃, fun hs₃s₁ => hs₁s₂.2 (Subset.trans hs₂s₃ hs₃s₁)⟩
#align set.ssubset_of_ssubset_of_subset Set.ssubset_of_ssubset_of_subset
protected theorem ssubset_of_subset_of_ssubset {s₁ s₂ s₃ : Set α} (hs₁s₂ : s₁ ⊆ s₂)
(hs₂s₃ : s₂ ⊂ s₃) : s₁ ⊂ s₃ :=
⟨Subset.trans hs₁s₂ hs₂s₃.1, fun hs₃s₁ => hs₂s₃.2 (Subset.trans hs₃s₁ hs₁s₂)⟩
#align set.ssubset_of_subset_of_ssubset Set.ssubset_of_subset_of_ssubset
theorem not_mem_empty (x : α) : ¬x ∈ (∅ : Set α) :=
id
#align set.not_mem_empty Set.not_mem_empty
-- Porting note (#10618): removed `simp` because `simp` can prove it
theorem not_not_mem : ¬a ∉ s ↔ a ∈ s :=
not_not
#align set.not_not_mem Set.not_not_mem
-- Porting note: we seem to need parentheses at `(↥s)`,
-- even if we increase the right precedence of `↥` in `Mathlib.Tactic.Coe`.
-- Porting note: removed `simp` as it is competing with `nonempty_subtype`.
-- @[simp]
theorem nonempty_coe_sort {s : Set α} : Nonempty (↥s) ↔ s.Nonempty :=
nonempty_subtype
#align set.nonempty_coe_sort Set.nonempty_coe_sort
alias ⟨_, Nonempty.coe_sort⟩ := nonempty_coe_sort
#align set.nonempty.coe_sort Set.Nonempty.coe_sort
theorem nonempty_def : s.Nonempty ↔ ∃ x, x ∈ s :=
Iff.rfl
#align set.nonempty_def Set.nonempty_def
theorem nonempty_of_mem {x} (h : x ∈ s) : s.Nonempty :=
⟨x, h⟩
#align set.nonempty_of_mem Set.nonempty_of_mem
theorem Nonempty.not_subset_empty : s.Nonempty → ¬s ⊆ ∅
| ⟨_, hx⟩, hs => hs hx
#align set.nonempty.not_subset_empty Set.Nonempty.not_subset_empty
protected noncomputable def Nonempty.some (h : s.Nonempty) : α :=
Classical.choose h
#align set.nonempty.some Set.Nonempty.some
protected theorem Nonempty.some_mem (h : s.Nonempty) : h.some ∈ s :=
Classical.choose_spec h
#align set.nonempty.some_mem Set.Nonempty.some_mem
theorem Nonempty.mono (ht : s ⊆ t) (hs : s.Nonempty) : t.Nonempty :=
hs.imp ht
#align set.nonempty.mono Set.Nonempty.mono
theorem nonempty_of_not_subset (h : ¬s ⊆ t) : (s \ t).Nonempty :=
let ⟨x, xs, xt⟩ := not_subset.1 h
⟨x, xs, xt⟩
#align set.nonempty_of_not_subset Set.nonempty_of_not_subset
theorem nonempty_of_ssubset (ht : s ⊂ t) : (t \ s).Nonempty :=
nonempty_of_not_subset ht.2
#align set.nonempty_of_ssubset Set.nonempty_of_ssubset
theorem Nonempty.of_diff (h : (s \ t).Nonempty) : s.Nonempty :=
h.imp fun _ => And.left
#align set.nonempty.of_diff Set.Nonempty.of_diff
theorem nonempty_of_ssubset' (ht : s ⊂ t) : t.Nonempty :=
(nonempty_of_ssubset ht).of_diff
#align set.nonempty_of_ssubset' Set.nonempty_of_ssubset'
theorem Nonempty.inl (hs : s.Nonempty) : (s ∪ t).Nonempty :=
hs.imp fun _ => Or.inl
#align set.nonempty.inl Set.Nonempty.inl
theorem Nonempty.inr (ht : t.Nonempty) : (s ∪ t).Nonempty :=
ht.imp fun _ => Or.inr
#align set.nonempty.inr Set.Nonempty.inr
@[simp]
theorem union_nonempty : (s ∪ t).Nonempty ↔ s.Nonempty ∨ t.Nonempty :=
exists_or
#align set.union_nonempty Set.union_nonempty
theorem Nonempty.left (h : (s ∩ t).Nonempty) : s.Nonempty :=
h.imp fun _ => And.left
#align set.nonempty.left Set.Nonempty.left
theorem Nonempty.right (h : (s ∩ t).Nonempty) : t.Nonempty :=
h.imp fun _ => And.right
#align set.nonempty.right Set.Nonempty.right
theorem inter_nonempty : (s ∩ t).Nonempty ↔ ∃ x, x ∈ s ∧ x ∈ t :=
Iff.rfl
#align set.inter_nonempty Set.inter_nonempty
theorem inter_nonempty_iff_exists_left : (s ∩ t).Nonempty ↔ ∃ x ∈ s, x ∈ t := by
simp_rw [inter_nonempty]
#align set.inter_nonempty_iff_exists_left Set.inter_nonempty_iff_exists_left
theorem inter_nonempty_iff_exists_right : (s ∩ t).Nonempty ↔ ∃ x ∈ t, x ∈ s := by
simp_rw [inter_nonempty, and_comm]
#align set.inter_nonempty_iff_exists_right Set.inter_nonempty_iff_exists_right
theorem nonempty_iff_univ_nonempty : Nonempty α ↔ (univ : Set α).Nonempty :=
⟨fun ⟨x⟩ => ⟨x, trivial⟩, fun ⟨x, _⟩ => ⟨x⟩⟩
#align set.nonempty_iff_univ_nonempty Set.nonempty_iff_univ_nonempty
@[simp]
theorem univ_nonempty : ∀ [Nonempty α], (univ : Set α).Nonempty
| ⟨x⟩ => ⟨x, trivial⟩
#align set.univ_nonempty Set.univ_nonempty
theorem Nonempty.to_subtype : s.Nonempty → Nonempty (↥s) :=
nonempty_subtype.2
#align set.nonempty.to_subtype Set.Nonempty.to_subtype
theorem Nonempty.to_type : s.Nonempty → Nonempty α := fun ⟨x, _⟩ => ⟨x⟩
#align set.nonempty.to_type Set.Nonempty.to_type
instance univ.nonempty [Nonempty α] : Nonempty (↥(Set.univ : Set α)) :=
Set.univ_nonempty.to_subtype
#align set.univ.nonempty Set.univ.nonempty
theorem nonempty_of_nonempty_subtype [Nonempty (↥s)] : s.Nonempty :=
nonempty_subtype.mp ‹_›
#align set.nonempty_of_nonempty_subtype Set.nonempty_of_nonempty_subtype
theorem empty_def : (∅ : Set α) = { _x : α | False } :=
rfl
#align set.empty_def Set.empty_def
@[simp]
theorem mem_empty_iff_false (x : α) : x ∈ (∅ : Set α) ↔ False :=
Iff.rfl
#align set.mem_empty_iff_false Set.mem_empty_iff_false
@[simp]
theorem setOf_false : { _a : α | False } = ∅ :=
rfl
#align set.set_of_false Set.setOf_false
@[simp] theorem setOf_bot : { _x : α | ⊥ } = ∅ := rfl
@[simp]
theorem empty_subset (s : Set α) : ∅ ⊆ s :=
nofun
#align set.empty_subset Set.empty_subset
theorem subset_empty_iff {s : Set α} : s ⊆ ∅ ↔ s = ∅ :=
(Subset.antisymm_iff.trans <| and_iff_left (empty_subset _)).symm
#align set.subset_empty_iff Set.subset_empty_iff
theorem eq_empty_iff_forall_not_mem {s : Set α} : s = ∅ ↔ ∀ x, x ∉ s :=
subset_empty_iff.symm
#align set.eq_empty_iff_forall_not_mem Set.eq_empty_iff_forall_not_mem
theorem eq_empty_of_forall_not_mem (h : ∀ x, x ∉ s) : s = ∅ :=
subset_empty_iff.1 h
#align set.eq_empty_of_forall_not_mem Set.eq_empty_of_forall_not_mem
theorem eq_empty_of_subset_empty {s : Set α} : s ⊆ ∅ → s = ∅ :=
subset_empty_iff.1
#align set.eq_empty_of_subset_empty Set.eq_empty_of_subset_empty
theorem eq_empty_of_isEmpty [IsEmpty α] (s : Set α) : s = ∅ :=
eq_empty_of_subset_empty fun x _ => isEmptyElim x
#align set.eq_empty_of_is_empty Set.eq_empty_of_isEmpty
instance uniqueEmpty [IsEmpty α] : Unique (Set α) where
default := ∅
uniq := eq_empty_of_isEmpty
#align set.unique_empty Set.uniqueEmpty
theorem not_nonempty_iff_eq_empty {s : Set α} : ¬s.Nonempty ↔ s = ∅ := by
simp only [Set.Nonempty, not_exists, eq_empty_iff_forall_not_mem]
#align set.not_nonempty_iff_eq_empty Set.not_nonempty_iff_eq_empty
theorem nonempty_iff_ne_empty : s.Nonempty ↔ s ≠ ∅ :=
not_nonempty_iff_eq_empty.not_right
#align set.nonempty_iff_ne_empty Set.nonempty_iff_ne_empty
theorem not_nonempty_iff_eq_empty' : ¬Nonempty s ↔ s = ∅ := by
rw [nonempty_subtype, not_exists, eq_empty_iff_forall_not_mem]
theorem nonempty_iff_ne_empty' : Nonempty s ↔ s ≠ ∅ :=
not_nonempty_iff_eq_empty'.not_right
alias ⟨Nonempty.ne_empty, _⟩ := nonempty_iff_ne_empty
#align set.nonempty.ne_empty Set.Nonempty.ne_empty
@[simp]
theorem not_nonempty_empty : ¬(∅ : Set α).Nonempty := fun ⟨_, hx⟩ => hx
#align set.not_nonempty_empty Set.not_nonempty_empty
-- Porting note: removing `@[simp]` as it is competing with `isEmpty_subtype`.
-- @[simp]
theorem isEmpty_coe_sort {s : Set α} : IsEmpty (↥s) ↔ s = ∅ :=
not_iff_not.1 <| by simpa using nonempty_iff_ne_empty
#align set.is_empty_coe_sort Set.isEmpty_coe_sort
theorem eq_empty_or_nonempty (s : Set α) : s = ∅ ∨ s.Nonempty :=
or_iff_not_imp_left.2 nonempty_iff_ne_empty.2
#align set.eq_empty_or_nonempty Set.eq_empty_or_nonempty
theorem subset_eq_empty {s t : Set α} (h : t ⊆ s) (e : s = ∅) : t = ∅ :=
subset_empty_iff.1 <| e ▸ h
#align set.subset_eq_empty Set.subset_eq_empty
theorem forall_mem_empty {p : α → Prop} : (∀ x ∈ (∅ : Set α), p x) ↔ True :=
iff_true_intro fun _ => False.elim
#align set.ball_empty_iff Set.forall_mem_empty
@[deprecated (since := "2024-03-23")] alias ball_empty_iff := forall_mem_empty
instance (α : Type u) : IsEmpty.{u + 1} (↥(∅ : Set α)) :=
⟨fun x => x.2⟩
@[simp]
theorem empty_ssubset : ∅ ⊂ s ↔ s.Nonempty :=
(@bot_lt_iff_ne_bot (Set α) _ _ _).trans nonempty_iff_ne_empty.symm
#align set.empty_ssubset Set.empty_ssubset
alias ⟨_, Nonempty.empty_ssubset⟩ := empty_ssubset
#align set.nonempty.empty_ssubset Set.Nonempty.empty_ssubset
@[simp]
theorem setOf_true : { _x : α | True } = univ :=
rfl
#align set.set_of_true Set.setOf_true
@[simp] theorem setOf_top : { _x : α | ⊤ } = univ := rfl
@[simp]
theorem univ_eq_empty_iff : (univ : Set α) = ∅ ↔ IsEmpty α :=
eq_empty_iff_forall_not_mem.trans
⟨fun H => ⟨fun x => H x trivial⟩, fun H x _ => @IsEmpty.false α H x⟩
#align set.univ_eq_empty_iff Set.univ_eq_empty_iff
theorem empty_ne_univ [Nonempty α] : (∅ : Set α) ≠ univ := fun e =>
not_isEmpty_of_nonempty α <| univ_eq_empty_iff.1 e.symm
#align set.empty_ne_univ Set.empty_ne_univ
@[simp]
theorem subset_univ (s : Set α) : s ⊆ univ := fun _ _ => trivial
#align set.subset_univ Set.subset_univ
@[simp]
theorem univ_subset_iff {s : Set α} : univ ⊆ s ↔ s = univ :=
@top_le_iff _ _ _ s
#align set.univ_subset_iff Set.univ_subset_iff
alias ⟨eq_univ_of_univ_subset, _⟩ := univ_subset_iff
#align set.eq_univ_of_univ_subset Set.eq_univ_of_univ_subset
theorem eq_univ_iff_forall {s : Set α} : s = univ ↔ ∀ x, x ∈ s :=
univ_subset_iff.symm.trans <| forall_congr' fun _ => imp_iff_right trivial
#align set.eq_univ_iff_forall Set.eq_univ_iff_forall
theorem eq_univ_of_forall {s : Set α} : (∀ x, x ∈ s) → s = univ :=
eq_univ_iff_forall.2
#align set.eq_univ_of_forall Set.eq_univ_of_forall
theorem Nonempty.eq_univ [Subsingleton α] : s.Nonempty → s = univ := by
rintro ⟨x, hx⟩
exact eq_univ_of_forall fun y => by rwa [Subsingleton.elim y x]
#align set.nonempty.eq_univ Set.Nonempty.eq_univ
theorem eq_univ_of_subset {s t : Set α} (h : s ⊆ t) (hs : s = univ) : t = univ :=
eq_univ_of_univ_subset <| (hs ▸ h : univ ⊆ t)
#align set.eq_univ_of_subset Set.eq_univ_of_subset
theorem exists_mem_of_nonempty (α) : ∀ [Nonempty α], ∃ x : α, x ∈ (univ : Set α)
| ⟨x⟩ => ⟨x, trivial⟩
#align set.exists_mem_of_nonempty Set.exists_mem_of_nonempty
theorem ne_univ_iff_exists_not_mem {α : Type*} (s : Set α) : s ≠ univ ↔ ∃ a, a ∉ s := by
rw [← not_forall, ← eq_univ_iff_forall]
#align set.ne_univ_iff_exists_not_mem Set.ne_univ_iff_exists_not_mem
| Mathlib/Data/Set/Basic.lean | 693 | 694 | theorem not_subset_iff_exists_mem_not_mem {α : Type*} {s t : Set α} :
¬s ⊆ t ↔ ∃ x, x ∈ s ∧ x ∉ t := by | simp [subset_def]
|
import Mathlib.Algebra.Polynomial.AlgebraMap
import Mathlib.Algebra.Polynomial.Basic
import Mathlib.RingTheory.Ideal.Maps
import Mathlib.RingTheory.MvPowerSeries.Basic
#align_import ring_theory.power_series.basic from "leanprover-community/mathlib"@"2d5739b61641ee4e7e53eca5688a08f66f2e6a60"
noncomputable section
open Finset (antidiagonal mem_antidiagonal)
def PowerSeries (R : Type*) :=
MvPowerSeries Unit R
#align power_series PowerSeries
namespace PowerSeries
open Finsupp (single)
variable {R : Type*}
section
-- Porting note: not available in Lean 4
-- local reducible PowerSeries
scoped notation:9000 R "⟦X⟧" => PowerSeries R
instance [Inhabited R] : Inhabited R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [Zero R] : Zero R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [AddMonoid R] : AddMonoid R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [AddGroup R] : AddGroup R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [AddCommMonoid R] : AddCommMonoid R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [AddCommGroup R] : AddCommGroup R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [Semiring R] : Semiring R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [CommSemiring R] : CommSemiring R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [Ring R] : Ring R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [CommRing R] : CommRing R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [Nontrivial R] : Nontrivial R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance {A} [Semiring R] [AddCommMonoid A] [Module R A] : Module R A⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance {A S} [Semiring R] [Semiring S] [AddCommMonoid A] [Module R A] [Module S A] [SMul R S]
[IsScalarTower R S A] : IsScalarTower R S A⟦X⟧ :=
Pi.isScalarTower
instance {A} [Semiring A] [CommSemiring R] [Algebra R A] : Algebra R A⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
end
section Semiring
variable (R) [Semiring R]
def coeff (n : ℕ) : R⟦X⟧ →ₗ[R] R :=
MvPowerSeries.coeff R (single () n)
#align power_series.coeff PowerSeries.coeff
def monomial (n : ℕ) : R →ₗ[R] R⟦X⟧ :=
MvPowerSeries.monomial R (single () n)
#align power_series.monomial PowerSeries.monomial
variable {R}
theorem coeff_def {s : Unit →₀ ℕ} {n : ℕ} (h : s () = n) : coeff R n = MvPowerSeries.coeff R s := by
erw [coeff, ← h, ← Finsupp.unique_single s]
#align power_series.coeff_def PowerSeries.coeff_def
@[ext]
theorem ext {φ ψ : R⟦X⟧} (h : ∀ n, coeff R n φ = coeff R n ψ) : φ = ψ :=
MvPowerSeries.ext fun n => by
rw [← coeff_def]
· apply h
rfl
#align power_series.ext PowerSeries.ext
theorem ext_iff {φ ψ : R⟦X⟧} : φ = ψ ↔ ∀ n, coeff R n φ = coeff R n ψ :=
⟨fun h n => congr_arg (coeff R n) h, ext⟩
#align power_series.ext_iff PowerSeries.ext_iff
instance [Subsingleton R] : Subsingleton R⟦X⟧ := by
simp only [subsingleton_iff, ext_iff]
exact fun _ _ _ ↦ (subsingleton_iff).mp (by infer_instance) _ _
def mk {R} (f : ℕ → R) : R⟦X⟧ := fun s => f (s ())
#align power_series.mk PowerSeries.mk
@[simp]
theorem coeff_mk (n : ℕ) (f : ℕ → R) : coeff R n (mk f) = f n :=
congr_arg f Finsupp.single_eq_same
#align power_series.coeff_mk PowerSeries.coeff_mk
theorem coeff_monomial (m n : ℕ) (a : R) : coeff R m (monomial R n a) = if m = n then a else 0 :=
calc
coeff R m (monomial R n a) = _ := MvPowerSeries.coeff_monomial _ _ _
_ = if m = n then a else 0 := by simp only [Finsupp.unique_single_eq_iff]
#align power_series.coeff_monomial PowerSeries.coeff_monomial
theorem monomial_eq_mk (n : ℕ) (a : R) : monomial R n a = mk fun m => if m = n then a else 0 :=
ext fun m => by rw [coeff_monomial, coeff_mk]
#align power_series.monomial_eq_mk PowerSeries.monomial_eq_mk
@[simp]
theorem coeff_monomial_same (n : ℕ) (a : R) : coeff R n (monomial R n a) = a :=
MvPowerSeries.coeff_monomial_same _ _
#align power_series.coeff_monomial_same PowerSeries.coeff_monomial_same
@[simp]
theorem coeff_comp_monomial (n : ℕ) : (coeff R n).comp (monomial R n) = LinearMap.id :=
LinearMap.ext <| coeff_monomial_same n
#align power_series.coeff_comp_monomial PowerSeries.coeff_comp_monomial
variable (R)
def constantCoeff : R⟦X⟧ →+* R :=
MvPowerSeries.constantCoeff Unit R
#align power_series.constant_coeff PowerSeries.constantCoeff
def C : R →+* R⟦X⟧ :=
MvPowerSeries.C Unit R
set_option linter.uppercaseLean3 false in
#align power_series.C PowerSeries.C
variable {R}
def X : R⟦X⟧ :=
MvPowerSeries.X ()
set_option linter.uppercaseLean3 false in
#align power_series.X PowerSeries.X
theorem commute_X (φ : R⟦X⟧) : Commute φ X :=
MvPowerSeries.commute_X _ _
set_option linter.uppercaseLean3 false in
#align power_series.commute_X PowerSeries.commute_X
@[simp]
theorem coeff_zero_eq_constantCoeff : ⇑(coeff R 0) = constantCoeff R := by
rw [coeff, Finsupp.single_zero]
rfl
#align power_series.coeff_zero_eq_constant_coeff PowerSeries.coeff_zero_eq_constantCoeff
theorem coeff_zero_eq_constantCoeff_apply (φ : R⟦X⟧) : coeff R 0 φ = constantCoeff R φ := by
rw [coeff_zero_eq_constantCoeff]
#align power_series.coeff_zero_eq_constant_coeff_apply PowerSeries.coeff_zero_eq_constantCoeff_apply
@[simp]
theorem monomial_zero_eq_C : ⇑(monomial R 0) = C R := by
-- This used to be `rw`, but we need `erw` after leanprover/lean4#2644
erw [monomial, Finsupp.single_zero, MvPowerSeries.monomial_zero_eq_C]
set_option linter.uppercaseLean3 false in
#align power_series.monomial_zero_eq_C PowerSeries.monomial_zero_eq_C
theorem monomial_zero_eq_C_apply (a : R) : monomial R 0 a = C R a := by simp
set_option linter.uppercaseLean3 false in
#align power_series.monomial_zero_eq_C_apply PowerSeries.monomial_zero_eq_C_apply
theorem coeff_C (n : ℕ) (a : R) : coeff R n (C R a : R⟦X⟧) = if n = 0 then a else 0 := by
rw [← monomial_zero_eq_C_apply, coeff_monomial]
set_option linter.uppercaseLean3 false in
#align power_series.coeff_C PowerSeries.coeff_C
@[simp]
theorem coeff_zero_C (a : R) : coeff R 0 (C R a) = a := by
rw [coeff_C, if_pos rfl]
set_option linter.uppercaseLean3 false in
#align power_series.coeff_zero_C PowerSeries.coeff_zero_C
theorem coeff_ne_zero_C {a : R} {n : ℕ} (h : n ≠ 0) : coeff R n (C R a) = 0 := by
rw [coeff_C, if_neg h]
@[simp]
theorem coeff_succ_C {a : R} {n : ℕ} : coeff R (n + 1) (C R a) = 0 :=
coeff_ne_zero_C n.succ_ne_zero
| Mathlib/RingTheory/PowerSeries/Basic.lean | 267 | 270 | theorem C_injective : Function.Injective (C R) := by |
intro a b H
have := (ext_iff (φ := C R a) (ψ := C R b)).mp H 0
rwa [coeff_zero_C, coeff_zero_C] at this
|
import Mathlib.AlgebraicGeometry.Gluing
import Mathlib.CategoryTheory.Limits.Opposites
import Mathlib.AlgebraicGeometry.AffineScheme
import Mathlib.CategoryTheory.Limits.Shapes.Diagonal
#align_import algebraic_geometry.pullbacks from "leanprover-community/mathlib"@"7316286ff2942aa14e540add9058c6b0aa1c8070"
set_option linter.uppercaseLean3 false
universe v u
noncomputable section
open CategoryTheory CategoryTheory.Limits AlgebraicGeometry
namespace AlgebraicGeometry.Scheme
namespace Pullback
variable {C : Type u} [Category.{v} C]
variable {X Y Z : Scheme.{u}} (𝒰 : OpenCover.{u} X) (f : X ⟶ Z) (g : Y ⟶ Z)
variable [∀ i, HasPullback (𝒰.map i ≫ f) g]
def v (i j : 𝒰.J) : Scheme :=
pullback ((pullback.fst : pullback (𝒰.map i ≫ f) g ⟶ _) ≫ 𝒰.map i) (𝒰.map j)
#align algebraic_geometry.Scheme.pullback.V AlgebraicGeometry.Scheme.Pullback.v
def t (i j : 𝒰.J) : v 𝒰 f g i j ⟶ v 𝒰 f g j i := by
have : HasPullback (pullback.snd ≫ 𝒰.map i ≫ f) g :=
hasPullback_assoc_symm (𝒰.map j) (𝒰.map i) (𝒰.map i ≫ f) g
have : HasPullback (pullback.snd ≫ 𝒰.map j ≫ f) g :=
hasPullback_assoc_symm (𝒰.map i) (𝒰.map j) (𝒰.map j ≫ f) g
refine (pullbackSymmetry ..).hom ≫ (pullbackAssoc ..).inv ≫ ?_
refine ?_ ≫ (pullbackAssoc ..).hom ≫ (pullbackSymmetry ..).hom
refine pullback.map _ _ _ _ (pullbackSymmetry _ _).hom (𝟙 _) (𝟙 _) ?_ ?_
· rw [pullbackSymmetry_hom_comp_snd_assoc, pullback.condition_assoc, Category.comp_id]
· rw [Category.comp_id, Category.id_comp]
#align algebraic_geometry.Scheme.pullback.t AlgebraicGeometry.Scheme.Pullback.t
@[simp, reassoc]
theorem t_fst_fst (i j : 𝒰.J) : t 𝒰 f g i j ≫ pullback.fst ≫ pullback.fst = pullback.snd := by
simp only [t, Category.assoc, pullbackSymmetry_hom_comp_fst_assoc, pullbackAssoc_hom_snd_fst,
pullback.lift_fst_assoc, pullbackSymmetry_hom_comp_snd, pullbackAssoc_inv_fst_fst,
pullbackSymmetry_hom_comp_fst]
#align algebraic_geometry.Scheme.pullback.t_fst_fst AlgebraicGeometry.Scheme.Pullback.t_fst_fst
@[simp, reassoc]
theorem t_fst_snd (i j : 𝒰.J) :
t 𝒰 f g i j ≫ pullback.fst ≫ pullback.snd = pullback.fst ≫ pullback.snd := by
simp only [t, Category.assoc, pullbackSymmetry_hom_comp_fst_assoc, pullbackAssoc_hom_snd_snd,
pullback.lift_snd, Category.comp_id, pullbackAssoc_inv_snd, pullbackSymmetry_hom_comp_snd_assoc]
#align algebraic_geometry.Scheme.pullback.t_fst_snd AlgebraicGeometry.Scheme.Pullback.t_fst_snd
@[simp, reassoc]
theorem t_snd (i j : 𝒰.J) : t 𝒰 f g i j ≫ pullback.snd = pullback.fst ≫ pullback.fst := by
simp only [t, Category.assoc, pullbackSymmetry_hom_comp_snd, pullbackAssoc_hom_fst,
pullback.lift_fst_assoc, pullbackSymmetry_hom_comp_fst, pullbackAssoc_inv_fst_snd,
pullbackSymmetry_hom_comp_snd_assoc]
#align algebraic_geometry.Scheme.pullback.t_snd AlgebraicGeometry.Scheme.Pullback.t_snd
theorem t_id (i : 𝒰.J) : t 𝒰 f g i i = 𝟙 _ := by
apply pullback.hom_ext <;> rw [Category.id_comp]
· apply pullback.hom_ext
· rw [← cancel_mono (𝒰.map i)]; simp only [pullback.condition, Category.assoc, t_fst_fst]
· simp only [Category.assoc, t_fst_snd]
· rw [← cancel_mono (𝒰.map i)]; simp only [pullback.condition, t_snd, Category.assoc]
#align algebraic_geometry.Scheme.pullback.t_id AlgebraicGeometry.Scheme.Pullback.t_id
abbrev fV (i j : 𝒰.J) : v 𝒰 f g i j ⟶ pullback (𝒰.map i ≫ f) g :=
pullback.fst
#align algebraic_geometry.Scheme.pullback.fV AlgebraicGeometry.Scheme.Pullback.fV
def t' (i j k : 𝒰.J) :
pullback (fV 𝒰 f g i j) (fV 𝒰 f g i k) ⟶ pullback (fV 𝒰 f g j k) (fV 𝒰 f g j i) := by
refine (pullbackRightPullbackFstIso ..).hom ≫ ?_
refine ?_ ≫ (pullbackSymmetry _ _).hom
refine ?_ ≫ (pullbackRightPullbackFstIso ..).inv
refine pullback.map _ _ _ _ (t 𝒰 f g i j) (𝟙 _) (𝟙 _) ?_ ?_
· simp_rw [Category.comp_id, t_fst_fst_assoc, ← pullback.condition]
· rw [Category.comp_id, Category.id_comp]
#align algebraic_geometry.Scheme.pullback.t' AlgebraicGeometry.Scheme.Pullback.t'
@[simp, reassoc]
theorem t'_fst_fst_fst (i j k : 𝒰.J) :
t' 𝒰 f g i j k ≫ pullback.fst ≫ pullback.fst ≫ pullback.fst = pullback.fst ≫ pullback.snd := by
simp only [t', Category.assoc, pullbackSymmetry_hom_comp_fst_assoc,
pullbackRightPullbackFstIso_inv_snd_fst_assoc, pullback.lift_fst_assoc, t_fst_fst,
pullbackRightPullbackFstIso_hom_fst_assoc]
#align algebraic_geometry.Scheme.pullback.t'_fst_fst_fst AlgebraicGeometry.Scheme.Pullback.t'_fst_fst_fst
@[simp, reassoc]
theorem t'_fst_fst_snd (i j k : 𝒰.J) :
t' 𝒰 f g i j k ≫ pullback.fst ≫ pullback.fst ≫ pullback.snd =
pullback.fst ≫ pullback.fst ≫ pullback.snd := by
simp only [t', Category.assoc, pullbackSymmetry_hom_comp_fst_assoc,
pullbackRightPullbackFstIso_inv_snd_fst_assoc, pullback.lift_fst_assoc, t_fst_snd,
pullbackRightPullbackFstIso_hom_fst_assoc]
#align algebraic_geometry.Scheme.pullback.t'_fst_fst_snd AlgebraicGeometry.Scheme.Pullback.t'_fst_fst_snd
@[simp, reassoc]
theorem t'_fst_snd (i j k : 𝒰.J) :
t' 𝒰 f g i j k ≫ pullback.fst ≫ pullback.snd = pullback.snd ≫ pullback.snd := by
simp only [t', Category.assoc, pullbackSymmetry_hom_comp_fst_assoc,
pullbackRightPullbackFstIso_inv_snd_snd, pullback.lift_snd, Category.comp_id,
pullbackRightPullbackFstIso_hom_snd]
#align algebraic_geometry.Scheme.pullback.t'_fst_snd AlgebraicGeometry.Scheme.Pullback.t'_fst_snd
@[simp, reassoc]
theorem t'_snd_fst_fst (i j k : 𝒰.J) :
t' 𝒰 f g i j k ≫ pullback.snd ≫ pullback.fst ≫ pullback.fst = pullback.fst ≫ pullback.snd := by
simp only [t', Category.assoc, pullbackSymmetry_hom_comp_snd_assoc,
pullbackRightPullbackFstIso_inv_fst_assoc, pullback.lift_fst_assoc, t_fst_fst,
pullbackRightPullbackFstIso_hom_fst_assoc]
#align algebraic_geometry.Scheme.pullback.t'_snd_fst_fst AlgebraicGeometry.Scheme.Pullback.t'_snd_fst_fst
@[simp, reassoc]
theorem t'_snd_fst_snd (i j k : 𝒰.J) :
t' 𝒰 f g i j k ≫ pullback.snd ≫ pullback.fst ≫ pullback.snd =
pullback.fst ≫ pullback.fst ≫ pullback.snd := by
simp only [t', Category.assoc, pullbackSymmetry_hom_comp_snd_assoc,
pullbackRightPullbackFstIso_inv_fst_assoc, pullback.lift_fst_assoc, t_fst_snd,
pullbackRightPullbackFstIso_hom_fst_assoc]
#align algebraic_geometry.Scheme.pullback.t'_snd_fst_snd AlgebraicGeometry.Scheme.Pullback.t'_snd_fst_snd
@[simp, reassoc]
theorem t'_snd_snd (i j k : 𝒰.J) :
t' 𝒰 f g i j k ≫ pullback.snd ≫ pullback.snd = pullback.fst ≫ pullback.fst ≫ pullback.fst := by
simp only [t', Category.assoc, pullbackSymmetry_hom_comp_snd_assoc,
pullbackRightPullbackFstIso_inv_fst_assoc, pullback.lift_fst_assoc, t_snd,
pullbackRightPullbackFstIso_hom_fst_assoc]
#align algebraic_geometry.Scheme.pullback.t'_snd_snd AlgebraicGeometry.Scheme.Pullback.t'_snd_snd
theorem cocycle_fst_fst_fst (i j k : 𝒰.J) :
t' 𝒰 f g i j k ≫ t' 𝒰 f g j k i ≫ t' 𝒰 f g k i j ≫ pullback.fst ≫ pullback.fst ≫ pullback.fst =
pullback.fst ≫ pullback.fst ≫ pullback.fst := by
simp only [t'_fst_fst_fst, t'_fst_snd, t'_snd_snd]
#align algebraic_geometry.Scheme.pullback.cocycle_fst_fst_fst AlgebraicGeometry.Scheme.Pullback.cocycle_fst_fst_fst
theorem cocycle_fst_fst_snd (i j k : 𝒰.J) :
t' 𝒰 f g i j k ≫ t' 𝒰 f g j k i ≫ t' 𝒰 f g k i j ≫ pullback.fst ≫ pullback.fst ≫ pullback.snd =
pullback.fst ≫ pullback.fst ≫ pullback.snd := by
simp only [t'_fst_fst_snd]
#align algebraic_geometry.Scheme.pullback.cocycle_fst_fst_snd AlgebraicGeometry.Scheme.Pullback.cocycle_fst_fst_snd
theorem cocycle_fst_snd (i j k : 𝒰.J) :
t' 𝒰 f g i j k ≫ t' 𝒰 f g j k i ≫ t' 𝒰 f g k i j ≫ pullback.fst ≫ pullback.snd =
pullback.fst ≫ pullback.snd := by
simp only [t'_fst_snd, t'_snd_snd, t'_fst_fst_fst]
#align algebraic_geometry.Scheme.pullback.cocycle_fst_snd AlgebraicGeometry.Scheme.Pullback.cocycle_fst_snd
theorem cocycle_snd_fst_fst (i j k : 𝒰.J) :
t' 𝒰 f g i j k ≫ t' 𝒰 f g j k i ≫ t' 𝒰 f g k i j ≫ pullback.snd ≫ pullback.fst ≫ pullback.fst =
pullback.snd ≫ pullback.fst ≫ pullback.fst := by
rw [← cancel_mono (𝒰.map i)]
simp only [pullback.condition_assoc, t'_snd_fst_fst, t'_fst_snd, t'_snd_snd]
#align algebraic_geometry.Scheme.pullback.cocycle_snd_fst_fst AlgebraicGeometry.Scheme.Pullback.cocycle_snd_fst_fst
theorem cocycle_snd_fst_snd (i j k : 𝒰.J) :
t' 𝒰 f g i j k ≫ t' 𝒰 f g j k i ≫ t' 𝒰 f g k i j ≫ pullback.snd ≫ pullback.fst ≫ pullback.snd =
pullback.snd ≫ pullback.fst ≫ pullback.snd := by
simp only [pullback.condition_assoc, t'_snd_fst_snd]
#align algebraic_geometry.Scheme.pullback.cocycle_snd_fst_snd AlgebraicGeometry.Scheme.Pullback.cocycle_snd_fst_snd
| Mathlib/AlgebraicGeometry/Pullbacks.lean | 190 | 193 | theorem cocycle_snd_snd (i j k : 𝒰.J) :
t' 𝒰 f g i j k ≫ t' 𝒰 f g j k i ≫ t' 𝒰 f g k i j ≫ pullback.snd ≫ pullback.snd =
pullback.snd ≫ pullback.snd := by |
simp only [t'_snd_snd, t'_fst_fst_fst, t'_fst_snd]
|
import Mathlib.Algebra.Module.Torsion
import Mathlib.SetTheory.Cardinal.Cofinality
import Mathlib.LinearAlgebra.FreeModule.Finite.Basic
import Mathlib.LinearAlgebra.Dimension.StrongRankCondition
#align_import linear_algebra.dimension from "leanprover-community/mathlib"@"47a5f8186becdbc826190ced4312f8199f9db6a5"
noncomputable section
universe u v v' w
variable {R : Type u} {M M₁ : Type v} {M' : Type v'} {ι : Type w}
variable [Ring R] [AddCommGroup M] [AddCommGroup M'] [AddCommGroup M₁]
variable [Module R M] [Module R M'] [Module R M₁]
attribute [local instance] nontrivial_of_invariantBasisNumber
open Cardinal Basis Submodule Function Set FiniteDimensional
theorem rank_le {n : ℕ}
(H : ∀ s : Finset M, (LinearIndependent R fun i : s => (i : M)) → s.card ≤ n) :
Module.rank R M ≤ n := by
rw [Module.rank_def]
apply ciSup_le'
rintro ⟨s, li⟩
exact linearIndependent_bounded_of_finset_linearIndependent_bounded H _ li
#align rank_le rank_le
section Finite
theorem Module.finite_of_rank_eq_nat [Module.Free R M] {n : ℕ} (h : Module.rank R M = n) :
Module.Finite R M := by
nontriviality R
obtain ⟨⟨ι, b⟩⟩ := Module.Free.exists_basis (R := R) (M := M)
have := mk_lt_aleph0_iff.mp <|
b.linearIndependent.cardinal_le_rank |>.trans_eq h |>.trans_lt <| nat_lt_aleph0 n
exact Module.Finite.of_basis b
theorem Module.finite_of_rank_eq_zero [NoZeroSMulDivisors R M]
(h : Module.rank R M = 0) :
Module.Finite R M := by
nontriviality R
rw [rank_zero_iff] at h
infer_instance
theorem Module.finite_of_rank_eq_one [Module.Free R M] (h : Module.rank R M = 1) :
Module.Finite R M :=
Module.finite_of_rank_eq_nat <| h.trans Nat.cast_one.symm
variable [StrongRankCondition R]
theorem Basis.nonempty_fintype_index_of_rank_lt_aleph0 {ι : Type*} (b : Basis ι R M)
(h : Module.rank R M < ℵ₀) : Nonempty (Fintype ι) := by
rwa [← Cardinal.lift_lt, ← b.mk_eq_rank, Cardinal.lift_aleph0, Cardinal.lift_lt_aleph0,
Cardinal.lt_aleph0_iff_fintype] at h
#align basis.nonempty_fintype_index_of_rank_lt_aleph_0 Basis.nonempty_fintype_index_of_rank_lt_aleph0
noncomputable def Basis.fintypeIndexOfRankLtAleph0 {ι : Type*} (b : Basis ι R M)
(h : Module.rank R M < ℵ₀) : Fintype ι :=
Classical.choice (b.nonempty_fintype_index_of_rank_lt_aleph0 h)
#align basis.fintype_index_of_rank_lt_aleph_0 Basis.fintypeIndexOfRankLtAleph0
theorem Basis.finite_index_of_rank_lt_aleph0 {ι : Type*} {s : Set ι} (b : Basis s R M)
(h : Module.rank R M < ℵ₀) : s.Finite :=
finite_def.2 (b.nonempty_fintype_index_of_rank_lt_aleph0 h)
#align basis.finite_index_of_rank_lt_aleph_0 Basis.finite_index_of_rank_lt_aleph0
@[deprecated (since := "2023-12-27")]
alias cardinal_mk_le_finrank_of_linearIndependent := LinearIndependent.cardinal_mk_le_finrank
@[deprecated (since := "2023-12-27")]
alias fintype_card_le_finrank_of_linearIndependent := LinearIndependent.fintype_card_le_finrank
@[deprecated (since := "2023-12-27")]
alias finset_card_le_finrank_of_linearIndependent := LinearIndependent.finset_card_le_finrank
@[deprecated (since := "2023-12-27")]
alias Module.Finite.lt_aleph0_of_linearIndependent := LinearIndependent.lt_aleph0_of_finite
lemma exists_set_linearIndependent_of_lt_rank {n : Cardinal} (hn : n < Module.rank R M) :
∃ s : Set M, #s = n ∧ LinearIndependent R ((↑) : s → M) := by
obtain ⟨⟨s, hs⟩, hs'⟩ := exists_lt_of_lt_ciSup' (hn.trans_eq (Module.rank_def R M))
obtain ⟨t, ht, ht'⟩ := le_mk_iff_exists_subset.mp hs'.le
exact ⟨t, ht', .mono ht hs⟩
lemma exists_finset_linearIndependent_of_le_rank {n : ℕ} (hn : n ≤ Module.rank R M) :
∃ s : Finset M, s.card = n ∧ LinearIndependent R ((↑) : s → M) := by
have := nonempty_linearIndependent_set
cases' hn.eq_or_lt with h h
· obtain ⟨⟨s, hs⟩, hs'⟩ := Cardinal.exists_eq_natCast_of_iSup_eq _
(Cardinal.bddAbove_range.{v, v} _) _ (h.trans (Module.rank_def R M)).symm
have : Finite s := lt_aleph0_iff_finite.mp (hs' ▸ nat_lt_aleph0 n)
cases nonempty_fintype s
exact ⟨s.toFinset, by simpa using hs', by convert hs <;> exact Set.mem_toFinset⟩
· obtain ⟨s, hs, hs'⟩ := exists_set_linearIndependent_of_lt_rank h
have : Finite s := lt_aleph0_iff_finite.mp (hs ▸ nat_lt_aleph0 n)
cases nonempty_fintype s
exact ⟨s.toFinset, by simpa using hs, by convert hs' <;> exact Set.mem_toFinset⟩
lemma exists_linearIndependent_of_le_rank {n : ℕ} (hn : n ≤ Module.rank R M) :
∃ f : Fin n → M, LinearIndependent R f :=
have ⟨_, hs, hs'⟩ := exists_finset_linearIndependent_of_le_rank hn
⟨_, (linearIndependent_equiv (Finset.equivFinOfCardEq hs).symm).mpr hs'⟩
lemma natCast_le_rank_iff {n : ℕ} :
n ≤ Module.rank R M ↔ ∃ f : Fin n → M, LinearIndependent R f :=
⟨exists_linearIndependent_of_le_rank,
fun H ↦ by simpa using H.choose_spec.cardinal_lift_le_rank⟩
lemma natCast_le_rank_iff_finset {n : ℕ} :
n ≤ Module.rank R M ↔ ∃ s : Finset M, s.card = n ∧ LinearIndependent R ((↑) : s → M) :=
⟨exists_finset_linearIndependent_of_le_rank,
fun ⟨s, h₁, h₂⟩ ↦ by simpa [h₁] using h₂.cardinal_le_rank⟩
lemma exists_finset_linearIndependent_of_le_finrank {n : ℕ} (hn : n ≤ finrank R M) :
∃ s : Finset M, s.card = n ∧ LinearIndependent R ((↑) : s → M) := by
by_cases h : finrank R M = 0
· rw [le_zero_iff.mp (hn.trans_eq h)]
exact ⟨∅, rfl, by convert linearIndependent_empty R M using 2 <;> aesop⟩
exact exists_finset_linearIndependent_of_le_rank
((natCast_le.mpr hn).trans_eq (cast_toNat_of_lt_aleph0 (toNat_ne_zero.mp h).2))
lemma exists_linearIndependent_of_le_finrank {n : ℕ} (hn : n ≤ finrank R M) :
∃ f : Fin n → M, LinearIndependent R f :=
have ⟨_, hs, hs'⟩ := exists_finset_linearIndependent_of_le_finrank hn
⟨_, (linearIndependent_equiv (Finset.equivFinOfCardEq hs).symm).mpr hs'⟩
variable [Module.Finite R M]
theorem Module.Finite.not_linearIndependent_of_infinite {ι : Type*} [Infinite ι]
(v : ι → M) : ¬LinearIndependent R v := mt LinearIndependent.finite <| @not_finite _ _
#align finite_dimensional.not_linear_independent_of_infinite Module.Finite.not_linearIndependent_of_infinite
variable [NoZeroSMulDivisors R M]
theorem CompleteLattice.Independent.subtype_ne_bot_le_rank [Nontrivial R]
{V : ι → Submodule R M} (hV : CompleteLattice.Independent V) :
Cardinal.lift.{v} #{ i : ι // V i ≠ ⊥ } ≤ Cardinal.lift.{w} (Module.rank R M) := by
set I := { i : ι // V i ≠ ⊥ }
have hI : ∀ i : I, ∃ v ∈ V i, v ≠ (0 : M) := by
intro i
rw [← Submodule.ne_bot_iff]
exact i.prop
choose v hvV hv using hI
have : LinearIndependent R v := (hV.comp Subtype.coe_injective).linearIndependent _ hvV hv
exact this.cardinal_lift_le_rank
#align complete_lattice.independent.subtype_ne_bot_le_rank CompleteLattice.Independent.subtype_ne_bot_le_rank
theorem CompleteLattice.Independent.subtype_ne_bot_le_finrank_aux
{p : ι → Submodule R M} (hp : CompleteLattice.Independent p) :
#{ i // p i ≠ ⊥ } ≤ (finrank R M : Cardinal.{w}) := by
suffices Cardinal.lift.{v} #{ i // p i ≠ ⊥ } ≤ Cardinal.lift.{v} (finrank R M : Cardinal.{w}) by
rwa [Cardinal.lift_le] at this
calc
Cardinal.lift.{v} #{ i // p i ≠ ⊥ } ≤ Cardinal.lift.{w} (Module.rank R M) :=
hp.subtype_ne_bot_le_rank
_ = Cardinal.lift.{w} (finrank R M : Cardinal.{v}) := by rw [finrank_eq_rank]
_ = Cardinal.lift.{v} (finrank R M : Cardinal.{w}) := by simp
#align complete_lattice.independent.subtype_ne_bot_le_finrank_aux CompleteLattice.Independent.subtype_ne_bot_le_finrank_aux
noncomputable def CompleteLattice.Independent.fintypeNeBotOfFiniteDimensional
{p : ι → Submodule R M} (hp : CompleteLattice.Independent p) :
Fintype { i : ι // p i ≠ ⊥ } := by
suffices #{ i // p i ≠ ⊥ } < (ℵ₀ : Cardinal.{w}) by
rw [Cardinal.lt_aleph0_iff_fintype] at this
exact this.some
refine lt_of_le_of_lt hp.subtype_ne_bot_le_finrank_aux ?_
simp [Cardinal.nat_lt_aleph0]
#align complete_lattice.independent.fintype_ne_bot_of_finite_dimensional CompleteLattice.Independent.fintypeNeBotOfFiniteDimensional
theorem CompleteLattice.Independent.subtype_ne_bot_le_finrank
{p : ι → Submodule R M} (hp : CompleteLattice.Independent p) [Fintype { i // p i ≠ ⊥ }] :
Fintype.card { i // p i ≠ ⊥ } ≤ finrank R M := by simpa using hp.subtype_ne_bot_le_finrank_aux
#align complete_lattice.independent.subtype_ne_bot_le_finrank CompleteLattice.Independent.subtype_ne_bot_le_finrank
section
open Finset
| Mathlib/LinearAlgebra/Dimension/Finite.lean | 323 | 328 | theorem Module.exists_nontrivial_relation_of_finrank_lt_card {t : Finset M}
(h : finrank R M < t.card) : ∃ f : M → R, ∑ e ∈ t, f e • e = 0 ∧ ∃ x ∈ t, f x ≠ 0 := by |
obtain ⟨g, sum, z, nonzero⟩ := Fintype.not_linearIndependent_iff.mp
(mt LinearIndependent.finset_card_le_finrank h.not_le)
refine ⟨Subtype.val.extend g 0, ?_, z, z.2, by rwa [Subtype.val_injective.extend_apply]⟩
rw [← Finset.sum_finset_coe]; convert sum; apply Subtype.val_injective.extend_apply
|
import Mathlib.Computability.Halting
import Mathlib.Computability.TuringMachine
import Mathlib.Data.Num.Lemmas
import Mathlib.Tactic.DeriveFintype
#align_import computability.tm_to_partrec from "leanprover-community/mathlib"@"6155d4351090a6fad236e3d2e4e0e4e7342668e8"
open Function (update)
open Relation
namespace Turing
namespace ToPartrec
inductive Code
| zero'
| succ
| tail
| cons : Code → Code → Code
| comp : Code → Code → Code
| case : Code → Code → Code
| fix : Code → Code
deriving DecidableEq, Inhabited
#align turing.to_partrec.code Turing.ToPartrec.Code
#align turing.to_partrec.code.zero' Turing.ToPartrec.Code.zero'
#align turing.to_partrec.code.succ Turing.ToPartrec.Code.succ
#align turing.to_partrec.code.tail Turing.ToPartrec.Code.tail
#align turing.to_partrec.code.cons Turing.ToPartrec.Code.cons
#align turing.to_partrec.code.comp Turing.ToPartrec.Code.comp
#align turing.to_partrec.code.case Turing.ToPartrec.Code.case
#align turing.to_partrec.code.fix Turing.ToPartrec.Code.fix
def Code.eval : Code → List ℕ →. List ℕ
| Code.zero' => fun v => pure (0 :: v)
| Code.succ => fun v => pure [v.headI.succ]
| Code.tail => fun v => pure v.tail
| Code.cons f fs => fun v => do
let n ← Code.eval f v
let ns ← Code.eval fs v
pure (n.headI :: ns)
| Code.comp f g => fun v => g.eval v >>= f.eval
| Code.case f g => fun v => v.headI.rec (f.eval v.tail) fun y _ => g.eval (y::v.tail)
| Code.fix f =>
PFun.fix fun v => (f.eval v).map fun v => if v.headI = 0 then Sum.inl v.tail else Sum.inr v.tail
#align turing.to_partrec.code.eval Turing.ToPartrec.Code.eval
set_option linter.uppercaseLean3 false
namespace PartrecToTM2
section
open ToPartrec
inductive Γ'
| consₗ
| cons
| bit0
| bit1
deriving DecidableEq, Inhabited, Fintype
#align turing.partrec_to_TM2.Γ' Turing.PartrecToTM2.Γ'
#align turing.partrec_to_TM2.Γ'.Cons Turing.PartrecToTM2.Γ'.consₗ
#align turing.partrec_to_TM2.Γ'.cons Turing.PartrecToTM2.Γ'.cons
#align turing.partrec_to_TM2.Γ'.bit0 Turing.PartrecToTM2.Γ'.bit0
#align turing.partrec_to_TM2.Γ'.bit1 Turing.PartrecToTM2.Γ'.bit1
inductive K'
| main
| rev
| aux
| stack
deriving DecidableEq, Inhabited
#align turing.partrec_to_TM2.K' Turing.PartrecToTM2.K'
#align turing.partrec_to_TM2.K'.main Turing.PartrecToTM2.K'.main
#align turing.partrec_to_TM2.K'.rev Turing.PartrecToTM2.K'.rev
#align turing.partrec_to_TM2.K'.aux Turing.PartrecToTM2.K'.aux
#align turing.partrec_to_TM2.K'.stack Turing.PartrecToTM2.K'.stack
open K'
inductive Cont'
| halt
| cons₁ : Code → Cont' → Cont'
| cons₂ : Cont' → Cont'
| comp : Code → Cont' → Cont'
| fix : Code → Cont' → Cont'
deriving DecidableEq, Inhabited
#align turing.partrec_to_TM2.cont' Turing.PartrecToTM2.Cont'
#align turing.partrec_to_TM2.cont'.halt Turing.PartrecToTM2.Cont'.halt
#align turing.partrec_to_TM2.cont'.cons₁ Turing.PartrecToTM2.Cont'.cons₁
#align turing.partrec_to_TM2.cont'.cons₂ Turing.PartrecToTM2.Cont'.cons₂
#align turing.partrec_to_TM2.cont'.comp Turing.PartrecToTM2.Cont'.comp
#align turing.partrec_to_TM2.cont'.fix Turing.PartrecToTM2.Cont'.fix
inductive Λ'
| move (p : Γ' → Bool) (k₁ k₂ : K') (q : Λ')
| clear (p : Γ' → Bool) (k : K') (q : Λ')
| copy (q : Λ')
| push (k : K') (s : Option Γ' → Option Γ') (q : Λ')
| read (f : Option Γ' → Λ')
| succ (q : Λ')
| pred (q₁ q₂ : Λ')
| ret (k : Cont')
#align turing.partrec_to_TM2.Λ' Turing.PartrecToTM2.Λ'
#align turing.partrec_to_TM2.Λ'.move Turing.PartrecToTM2.Λ'.move
#align turing.partrec_to_TM2.Λ'.clear Turing.PartrecToTM2.Λ'.clear
#align turing.partrec_to_TM2.Λ'.copy Turing.PartrecToTM2.Λ'.copy
#align turing.partrec_to_TM2.Λ'.push Turing.PartrecToTM2.Λ'.push
#align turing.partrec_to_TM2.Λ'.read Turing.PartrecToTM2.Λ'.read
#align turing.partrec_to_TM2.Λ'.succ Turing.PartrecToTM2.Λ'.succ
#align turing.partrec_to_TM2.Λ'.pred Turing.PartrecToTM2.Λ'.pred
#align turing.partrec_to_TM2.Λ'.ret Turing.PartrecToTM2.Λ'.ret
-- Porting note: `Turing.PartrecToTM2.Λ'.rec` is noncomputable in Lean4, so we make it computable.
compile_inductive% Code
compile_inductive% Cont'
compile_inductive% K'
compile_inductive% Λ'
instance Λ'.instInhabited : Inhabited Λ' :=
⟨Λ'.ret Cont'.halt⟩
#align turing.partrec_to_TM2.Λ'.inhabited Turing.PartrecToTM2.Λ'.instInhabited
instance Λ'.instDecidableEq : DecidableEq Λ' := fun a b => by
induction a generalizing b <;> cases b <;> first
| apply Decidable.isFalse; rintro ⟨⟨⟩⟩; done
| exact decidable_of_iff' _ (by simp [Function.funext_iff]; rfl)
#align turing.partrec_to_TM2.Λ'.decidable_eq Turing.PartrecToTM2.Λ'.instDecidableEq
def Stmt' :=
TM2.Stmt (fun _ : K' => Γ') Λ' (Option Γ') deriving Inhabited
#align turing.partrec_to_TM2.stmt' Turing.PartrecToTM2.Stmt'
def Cfg' :=
TM2.Cfg (fun _ : K' => Γ') Λ' (Option Γ') deriving Inhabited
#align turing.partrec_to_TM2.cfg' Turing.PartrecToTM2.Cfg'
open TM2.Stmt
@[simp]
def natEnd : Γ' → Bool
| Γ'.consₗ => true
| Γ'.cons => true
| _ => false
#align turing.partrec_to_TM2.nat_end Turing.PartrecToTM2.natEnd
@[simp]
def pop' (k : K') : Stmt' → Stmt' :=
pop k fun _ v => v
#align turing.partrec_to_TM2.pop' Turing.PartrecToTM2.pop'
@[simp]
def peek' (k : K') : Stmt' → Stmt' :=
peek k fun _ v => v
#align turing.partrec_to_TM2.peek' Turing.PartrecToTM2.peek'
@[simp]
def push' (k : K') : Stmt' → Stmt' :=
push k fun x => x.iget
#align turing.partrec_to_TM2.push' Turing.PartrecToTM2.push'
def unrev :=
Λ'.move (fun _ => false) rev main
#align turing.partrec_to_TM2.unrev Turing.PartrecToTM2.unrev
def moveExcl (p k₁ k₂ q) :=
Λ'.move p k₁ k₂ <| Λ'.push k₁ id q
#align turing.partrec_to_TM2.move_excl Turing.PartrecToTM2.moveExcl
def move₂ (p k₁ k₂ q) :=
moveExcl p k₁ rev <| Λ'.move (fun _ => false) rev k₂ q
#align turing.partrec_to_TM2.move₂ Turing.PartrecToTM2.move₂
def head (k : K') (q : Λ') : Λ' :=
Λ'.move natEnd k rev <|
(Λ'.push rev fun _ => some Γ'.cons) <|
Λ'.read fun s =>
(if s = some Γ'.consₗ then id else Λ'.clear (fun x => x = Γ'.consₗ) k) <| unrev q
#align turing.partrec_to_TM2.head Turing.PartrecToTM2.head
@[simp]
def trNormal : Code → Cont' → Λ'
| Code.zero', k => (Λ'.push main fun _ => some Γ'.cons) <| Λ'.ret k
| Code.succ, k => head main <| Λ'.succ <| Λ'.ret k
| Code.tail, k => Λ'.clear natEnd main <| Λ'.ret k
| Code.cons f fs, k =>
(Λ'.push stack fun _ => some Γ'.consₗ) <|
Λ'.move (fun _ => false) main rev <| Λ'.copy <| trNormal f (Cont'.cons₁ fs k)
| Code.comp f g, k => trNormal g (Cont'.comp f k)
| Code.case f g, k => Λ'.pred (trNormal f k) (trNormal g k)
| Code.fix f, k => trNormal f (Cont'.fix f k)
#align turing.partrec_to_TM2.tr_normal Turing.PartrecToTM2.trNormal
def tr : Λ' → Stmt'
| Λ'.move p k₁ k₂ q =>
pop' k₁ <|
branch (fun s => s.elim true p) (goto fun _ => q)
(push' k₂ <| goto fun _ => Λ'.move p k₁ k₂ q)
| Λ'.push k f q =>
branch (fun s => (f s).isSome) ((push k fun s => (f s).iget) <| goto fun _ => q)
(goto fun _ => q)
| Λ'.read q => goto q
| Λ'.clear p k q =>
pop' k <| branch (fun s => s.elim true p) (goto fun _ => q) (goto fun _ => Λ'.clear p k q)
| Λ'.copy q =>
pop' rev <|
branch Option.isSome (push' main <| push' stack <| goto fun _ => Λ'.copy q) (goto fun _ => q)
| Λ'.succ q =>
pop' main <|
branch (fun s => s = some Γ'.bit1) ((push rev fun _ => Γ'.bit0) <| goto fun _ => Λ'.succ q) <|
branch (fun s => s = some Γ'.cons)
((push main fun _ => Γ'.cons) <| (push main fun _ => Γ'.bit1) <| goto fun _ => unrev q)
((push main fun _ => Γ'.bit1) <| goto fun _ => unrev q)
| Λ'.pred q₁ q₂ =>
pop' main <|
branch (fun s => s = some Γ'.bit0)
((push rev fun _ => Γ'.bit1) <| goto fun _ => Λ'.pred q₁ q₂) <|
branch (fun s => natEnd s.iget) (goto fun _ => q₁)
(peek' main <|
branch (fun s => natEnd s.iget) (goto fun _ => unrev q₂)
((push rev fun _ => Γ'.bit0) <| goto fun _ => unrev q₂))
| Λ'.ret (Cont'.cons₁ fs k) =>
goto fun _ =>
move₂ (fun _ => false) main aux <|
move₂ (fun s => s = Γ'.consₗ) stack main <|
move₂ (fun _ => false) aux stack <| trNormal fs (Cont'.cons₂ k)
| Λ'.ret (Cont'.cons₂ k) => goto fun _ => head stack <| Λ'.ret k
| Λ'.ret (Cont'.comp f k) => goto fun _ => trNormal f k
| Λ'.ret (Cont'.fix f k) =>
pop' main <|
goto fun s =>
cond (natEnd s.iget) (Λ'.ret k) <| Λ'.clear natEnd main <| trNormal f (Cont'.fix f k)
| Λ'.ret Cont'.halt => (load fun _ => none) <| halt
#align turing.partrec_to_TM2.tr Turing.PartrecToTM2.tr
theorem tr_move (p k₁ k₂ q) : tr (Λ'.move p k₁ k₂ q) =
pop' k₁ (branch (fun s => s.elim true p) (goto fun _ => q)
(push' k₂ <| goto fun _ => Λ'.move p k₁ k₂ q)) := rfl
theorem tr_push (k f q) : tr (Λ'.push k f q) = branch (fun s => (f s).isSome)
((push k fun s => (f s).iget) <| goto fun _ => q) (goto fun _ => q) := rfl
theorem tr_read (q) : tr (Λ'.read q) = goto q := rfl
theorem tr_clear (p k q) : tr (Λ'.clear p k q) = pop' k (branch
(fun s => s.elim true p) (goto fun _ => q) (goto fun _ => Λ'.clear p k q)) := rfl
theorem tr_copy (q) : tr (Λ'.copy q) = pop' rev (branch Option.isSome
(push' main <| push' stack <| goto fun _ => Λ'.copy q) (goto fun _ => q)) := rfl
theorem tr_succ (q) : tr (Λ'.succ q) = pop' main (branch (fun s => s = some Γ'.bit1)
((push rev fun _ => Γ'.bit0) <| goto fun _ => Λ'.succ q) <|
branch (fun s => s = some Γ'.cons)
((push main fun _ => Γ'.cons) <| (push main fun _ => Γ'.bit1) <| goto fun _ => unrev q)
((push main fun _ => Γ'.bit1) <| goto fun _ => unrev q)) := rfl
theorem tr_pred (q₁ q₂) : tr (Λ'.pred q₁ q₂) = pop' main (branch (fun s => s = some Γ'.bit0)
((push rev fun _ => Γ'.bit1) <| goto fun _ => Λ'.pred q₁ q₂) <|
branch (fun s => natEnd s.iget) (goto fun _ => q₁)
(peek' main <|
branch (fun s => natEnd s.iget) (goto fun _ => unrev q₂)
((push rev fun _ => Γ'.bit0) <| goto fun _ => unrev q₂))) := rfl
theorem tr_ret_cons₁ (fs k) : tr (Λ'.ret (Cont'.cons₁ fs k)) = goto fun _ =>
move₂ (fun _ => false) main aux <|
move₂ (fun s => s = Γ'.consₗ) stack main <|
move₂ (fun _ => false) aux stack <| trNormal fs (Cont'.cons₂ k) := rfl
theorem tr_ret_cons₂ (k) : tr (Λ'.ret (Cont'.cons₂ k)) =
goto fun _ => head stack <| Λ'.ret k := rfl
theorem tr_ret_comp (f k) : tr (Λ'.ret (Cont'.comp f k)) = goto fun _ => trNormal f k := rfl
theorem tr_ret_fix (f k) : tr (Λ'.ret (Cont'.fix f k)) = pop' main (goto fun s =>
cond (natEnd s.iget) (Λ'.ret k) <| Λ'.clear natEnd main <| trNormal f (Cont'.fix f k)) := rfl
theorem tr_ret_halt : tr (Λ'.ret Cont'.halt) = (load fun _ => none) halt := rfl
attribute
[eqns tr_move tr_push tr_read tr_clear tr_copy tr_succ tr_pred tr_ret_cons₁
tr_ret_cons₂ tr_ret_comp tr_ret_fix tr_ret_halt] tr
attribute [simp] tr
def trCont : Cont → Cont'
| Cont.halt => Cont'.halt
| Cont.cons₁ c _ k => Cont'.cons₁ c (trCont k)
| Cont.cons₂ _ k => Cont'.cons₂ (trCont k)
| Cont.comp c k => Cont'.comp c (trCont k)
| Cont.fix c k => Cont'.fix c (trCont k)
#align turing.partrec_to_TM2.tr_cont Turing.PartrecToTM2.trCont
def trPosNum : PosNum → List Γ'
| PosNum.one => [Γ'.bit1]
| PosNum.bit0 n => Γ'.bit0 :: trPosNum n
| PosNum.bit1 n => Γ'.bit1 :: trPosNum n
#align turing.partrec_to_TM2.tr_pos_num Turing.PartrecToTM2.trPosNum
def trNum : Num → List Γ'
| Num.zero => []
| Num.pos n => trPosNum n
#align turing.partrec_to_TM2.tr_num Turing.PartrecToTM2.trNum
def trNat (n : ℕ) : List Γ' :=
trNum n
#align turing.partrec_to_TM2.tr_nat Turing.PartrecToTM2.trNat
@[simp]
theorem trNat_zero : trNat 0 = [] := by rw [trNat, Nat.cast_zero]; rfl
#align turing.partrec_to_TM2.tr_nat_zero Turing.PartrecToTM2.trNat_zero
theorem trNat_default : trNat default = [] :=
trNat_zero
#align turing.partrec_to_TM2.tr_nat_default Turing.PartrecToTM2.trNat_default
@[simp]
def trList : List ℕ → List Γ'
| [] => []
| n::ns => trNat n ++ Γ'.cons :: trList ns
#align turing.partrec_to_TM2.tr_list Turing.PartrecToTM2.trList
@[simp]
def trLList : List (List ℕ) → List Γ'
| [] => []
| l::ls => trList l ++ Γ'.consₗ :: trLList ls
#align turing.partrec_to_TM2.tr_llist Turing.PartrecToTM2.trLList
@[simp]
def contStack : Cont → List (List ℕ)
| Cont.halt => []
| Cont.cons₁ _ ns k => ns :: contStack k
| Cont.cons₂ ns k => ns :: contStack k
| Cont.comp _ k => contStack k
| Cont.fix _ k => contStack k
#align turing.partrec_to_TM2.cont_stack Turing.PartrecToTM2.contStack
def trContStack (k : Cont) :=
trLList (contStack k)
#align turing.partrec_to_TM2.tr_cont_stack Turing.PartrecToTM2.trContStack
def K'.elim (a b c d : List Γ') : K' → List Γ'
| K'.main => a
| K'.rev => b
| K'.aux => c
| K'.stack => d
#align turing.partrec_to_TM2.K'.elim Turing.PartrecToTM2.K'.elim
-- The equation lemma of `elim` simplifies to `match` structures.
theorem K'.elim_main (a b c d) : K'.elim a b c d K'.main = a := rfl
theorem K'.elim_rev (a b c d) : K'.elim a b c d K'.rev = b := rfl
theorem K'.elim_aux (a b c d) : K'.elim a b c d K'.aux = c := rfl
theorem K'.elim_stack (a b c d) : K'.elim a b c d K'.stack = d := rfl
attribute [simp] K'.elim
@[simp]
theorem K'.elim_update_main {a b c d a'} : update (K'.elim a b c d) main a' = K'.elim a' b c d := by
funext x; cases x <;> rfl
#align turing.partrec_to_TM2.K'.elim_update_main Turing.PartrecToTM2.K'.elim_update_main
@[simp]
theorem K'.elim_update_rev {a b c d b'} : update (K'.elim a b c d) rev b' = K'.elim a b' c d := by
funext x; cases x <;> rfl
#align turing.partrec_to_TM2.K'.elim_update_rev Turing.PartrecToTM2.K'.elim_update_rev
@[simp]
theorem K'.elim_update_aux {a b c d c'} : update (K'.elim a b c d) aux c' = K'.elim a b c' d := by
funext x; cases x <;> rfl
#align turing.partrec_to_TM2.K'.elim_update_aux Turing.PartrecToTM2.K'.elim_update_aux
@[simp]
theorem K'.elim_update_stack {a b c d d'} :
update (K'.elim a b c d) stack d' = K'.elim a b c d' := by funext x; cases x <;> rfl
#align turing.partrec_to_TM2.K'.elim_update_stack Turing.PartrecToTM2.K'.elim_update_stack
def halt (v : List ℕ) : Cfg' :=
⟨none, none, K'.elim (trList v) [] [] []⟩
#align turing.partrec_to_TM2.halt Turing.PartrecToTM2.halt
def TrCfg : Cfg → Cfg' → Prop
| Cfg.ret k v, c' =>
∃ s, c' = ⟨some (Λ'.ret (trCont k)), s, K'.elim (trList v) [] [] (trContStack k)⟩
| Cfg.halt v, c' => c' = halt v
#align turing.partrec_to_TM2.tr_cfg Turing.PartrecToTM2.TrCfg
def splitAtPred {α} (p : α → Bool) : List α → List α × Option α × List α
| [] => ([], none, [])
| a :: as =>
cond (p a) ([], some a, as) <|
let ⟨l₁, o, l₂⟩ := splitAtPred p as
⟨a::l₁, o, l₂⟩
#align turing.partrec_to_TM2.split_at_pred Turing.PartrecToTM2.splitAtPred
theorem splitAtPred_eq {α} (p : α → Bool) :
∀ L l₁ o l₂,
(∀ x ∈ l₁, p x = false) →
Option.elim' (L = l₁ ∧ l₂ = []) (fun a => p a = true ∧ L = l₁ ++ a::l₂) o →
splitAtPred p L = (l₁, o, l₂)
| [], _, none, _, _, ⟨rfl, rfl⟩ => rfl
| [], l₁, some o, l₂, _, ⟨_, h₃⟩ => by simp at h₃
| a :: L, l₁, o, l₂, h₁, h₂ => by
rw [splitAtPred]
have IH := splitAtPred_eq p L
cases' o with o
· cases' l₁ with a' l₁ <;> rcases h₂ with ⟨⟨⟩, rfl⟩
rw [h₁ a (List.Mem.head _), cond, IH L none [] _ ⟨rfl, rfl⟩]
exact fun x h => h₁ x (List.Mem.tail _ h)
· cases' l₁ with a' l₁ <;> rcases h₂ with ⟨h₂, ⟨⟩⟩
· rw [h₂, cond]
rw [h₁ a (List.Mem.head _), cond, IH l₁ (some o) l₂ _ ⟨h₂, _⟩] <;> try rfl
exact fun x h => h₁ x (List.Mem.tail _ h)
#align turing.partrec_to_TM2.split_at_pred_eq Turing.PartrecToTM2.splitAtPred_eq
theorem splitAtPred_false {α} (L : List α) : splitAtPred (fun _ => false) L = (L, none, []) :=
splitAtPred_eq _ _ _ _ _ (fun _ _ => rfl) ⟨rfl, rfl⟩
#align turing.partrec_to_TM2.split_at_pred_ff Turing.PartrecToTM2.splitAtPred_false
theorem move_ok {p k₁ k₂ q s L₁ o L₂} {S : K' → List Γ'} (h₁ : k₁ ≠ k₂)
(e : splitAtPred p (S k₁) = (L₁, o, L₂)) :
Reaches₁ (TM2.step tr) ⟨some (Λ'.move p k₁ k₂ q), s, S⟩
⟨some q, o, update (update S k₁ L₂) k₂ (L₁.reverseAux (S k₂))⟩ := by
induction' L₁ with a L₁ IH generalizing S s
· rw [(_ : [].reverseAux _ = _), Function.update_eq_self]
swap
· rw [Function.update_noteq h₁.symm, List.reverseAux_nil]
refine TransGen.head' rfl ?_
simp only [TM2.step, Option.mem_def, TM2.stepAux, Option.elim, ne_eq]
revert e; cases' S k₁ with a Sk <;> intro e
· cases e
rfl
simp only [splitAtPred, Option.elim, List.head?, List.tail_cons, Option.iget_some] at e ⊢
revert e; cases p a <;> intro e <;>
simp only [cond_false, cond_true, Prod.mk.injEq, true_and, false_and] at e ⊢
simp only [e]
rfl
· refine TransGen.head rfl ?_
simp only [TM2.step, Option.mem_def, TM2.stepAux, Option.elim, ne_eq, List.reverseAux_cons]
cases' e₁ : S k₁ with a' Sk <;> rw [e₁, splitAtPred] at e
· cases e
cases e₂ : p a' <;> simp only [e₂, cond] at e
swap
· cases e
rcases e₃ : splitAtPred p Sk with ⟨_, _, _⟩
rw [e₃] at e
cases e
simp only [List.head?_cons, e₂, List.tail_cons, ne_eq, cond_false]
convert @IH _ (update (update S k₁ Sk) k₂ (a :: S k₂)) _ using 2 <;>
simp [Function.update_noteq, h₁, h₁.symm, e₃, List.reverseAux]
simp [Function.update_comm h₁.symm]
#align turing.partrec_to_TM2.move_ok Turing.PartrecToTM2.move_ok
theorem unrev_ok {q s} {S : K' → List Γ'} :
Reaches₁ (TM2.step tr) ⟨some (unrev q), s, S⟩
⟨some q, none, update (update S rev []) main (List.reverseAux (S rev) (S main))⟩ :=
move_ok (by decide) <| splitAtPred_false _
#align turing.partrec_to_TM2.unrev_ok Turing.PartrecToTM2.unrev_ok
theorem move₂_ok {p k₁ k₂ q s L₁ o L₂} {S : K' → List Γ'} (h₁ : k₁ ≠ rev ∧ k₂ ≠ rev ∧ k₁ ≠ k₂)
(h₂ : S rev = []) (e : splitAtPred p (S k₁) = (L₁, o, L₂)) :
Reaches₁ (TM2.step tr) ⟨some (move₂ p k₁ k₂ q), s, S⟩
⟨some q, none, update (update S k₁ (o.elim id List.cons L₂)) k₂ (L₁ ++ S k₂)⟩ := by
refine (move_ok h₁.1 e).trans (TransGen.head rfl ?_)
simp only [TM2.step, Option.mem_def, TM2.stepAux, id_eq, ne_eq, Option.elim]
cases o <;> simp only [Option.elim, id]
· simp only [TM2.stepAux, Option.isSome, cond_false]
convert move_ok h₁.2.1.symm (splitAtPred_false _) using 2
simp only [Function.update_comm h₁.1, Function.update_idem]
rw [show update S rev [] = S by rw [← h₂, Function.update_eq_self]]
simp only [Function.update_noteq h₁.2.2.symm, Function.update_noteq h₁.2.1,
Function.update_noteq h₁.1.symm, List.reverseAux_eq, h₂, Function.update_same,
List.append_nil, List.reverse_reverse]
· simp only [TM2.stepAux, Option.isSome, cond_true]
convert move_ok h₁.2.1.symm (splitAtPred_false _) using 2
simp only [h₂, Function.update_comm h₁.1, List.reverseAux_eq, Function.update_same,
List.append_nil, Function.update_idem]
rw [show update S rev [] = S by rw [← h₂, Function.update_eq_self]]
simp only [Function.update_noteq h₁.1.symm, Function.update_noteq h₁.2.2.symm,
Function.update_noteq h₁.2.1, Function.update_same, List.reverse_reverse]
#align turing.partrec_to_TM2.move₂_ok Turing.PartrecToTM2.move₂_ok
theorem clear_ok {p k q s L₁ o L₂} {S : K' → List Γ'} (e : splitAtPred p (S k) = (L₁, o, L₂)) :
Reaches₁ (TM2.step tr) ⟨some (Λ'.clear p k q), s, S⟩ ⟨some q, o, update S k L₂⟩ := by
induction' L₁ with a L₁ IH generalizing S s
· refine TransGen.head' rfl ?_
simp only [TM2.step, Option.mem_def, TM2.stepAux, Option.elim]
revert e; cases' S k with a Sk <;> intro e
· cases e
rfl
simp only [splitAtPred, Option.elim, List.head?, List.tail_cons] at e ⊢
revert e; cases p a <;> intro e <;>
simp only [cond_false, cond_true, Prod.mk.injEq, true_and, false_and] at e ⊢
rcases e with ⟨e₁, e₂⟩
rw [e₁, e₂]
· refine TransGen.head rfl ?_
simp only [TM2.step, Option.mem_def, TM2.stepAux, Option.elim]
cases' e₁ : S k with a' Sk <;> rw [e₁, splitAtPred] at e
· cases e
cases e₂ : p a' <;> simp only [e₂, cond] at e
swap
· cases e
rcases e₃ : splitAtPred p Sk with ⟨_, _, _⟩
rw [e₃] at e
cases e
simp only [List.head?_cons, e₂, List.tail_cons, cond_false]
convert @IH _ (update S k Sk) _ using 2 <;> simp [e₃]
#align turing.partrec_to_TM2.clear_ok Turing.PartrecToTM2.clear_ok
theorem copy_ok (q s a b c d) :
Reaches₁ (TM2.step tr) ⟨some (Λ'.copy q), s, K'.elim a b c d⟩
⟨some q, none, K'.elim (List.reverseAux b a) [] c (List.reverseAux b d)⟩ := by
induction' b with x b IH generalizing a d s
· refine TransGen.single ?_
simp
refine TransGen.head rfl ?_
simp only [TM2.step, Option.mem_def, TM2.stepAux, elim_rev, List.head?_cons, Option.isSome_some,
List.tail_cons, elim_update_rev, ne_eq, Function.update_noteq, elim_main, elim_update_main,
elim_stack, elim_update_stack, cond_true, List.reverseAux_cons]
exact IH _ _ _
#align turing.partrec_to_TM2.copy_ok Turing.PartrecToTM2.copy_ok
theorem trPosNum_natEnd : ∀ (n), ∀ x ∈ trPosNum n, natEnd x = false
| PosNum.one, _, List.Mem.head _ => rfl
| PosNum.bit0 _, _, List.Mem.head _ => rfl
| PosNum.bit0 n, _, List.Mem.tail _ h => trPosNum_natEnd n _ h
| PosNum.bit1 _, _, List.Mem.head _ => rfl
| PosNum.bit1 n, _, List.Mem.tail _ h => trPosNum_natEnd n _ h
#align turing.partrec_to_TM2.tr_pos_num_nat_end Turing.PartrecToTM2.trPosNum_natEnd
theorem trNum_natEnd : ∀ (n), ∀ x ∈ trNum n, natEnd x = false
| Num.pos n, x, h => trPosNum_natEnd n x h
#align turing.partrec_to_TM2.tr_num_nat_end Turing.PartrecToTM2.trNum_natEnd
theorem trNat_natEnd (n) : ∀ x ∈ trNat n, natEnd x = false :=
trNum_natEnd _
#align turing.partrec_to_TM2.tr_nat_nat_end Turing.PartrecToTM2.trNat_natEnd
theorem trList_ne_consₗ : ∀ (l), ∀ x ∈ trList l, x ≠ Γ'.consₗ
| a :: l, x, h => by
simp [trList] at h
obtain h | rfl | h := h
· rintro rfl
cases trNat_natEnd _ _ h
· rintro ⟨⟩
· exact trList_ne_consₗ l _ h
#align turing.partrec_to_TM2.tr_list_ne_Cons Turing.PartrecToTM2.trList_ne_consₗ
theorem head_main_ok {q s L} {c d : List Γ'} :
Reaches₁ (TM2.step tr) ⟨some (head main q), s, K'.elim (trList L) [] c d⟩
⟨some q, none, K'.elim (trList [L.headI]) [] c d⟩ := by
let o : Option Γ' := List.casesOn L none fun _ _ => some Γ'.cons
refine
(move_ok (by decide)
(splitAtPred_eq _ _ (trNat L.headI) o (trList L.tail) (trNat_natEnd _) ?_)).trans
(TransGen.head rfl (TransGen.head rfl ?_))
· cases L <;> simp [o]
simp only [TM2.step, Option.mem_def, TM2.stepAux, elim_update_main, elim_rev, elim_update_rev,
Function.update_same, trList]
rw [if_neg (show o ≠ some Γ'.consₗ by cases L <;> simp [o])]
refine (clear_ok (splitAtPred_eq _ _ _ none [] ?_ ⟨rfl, rfl⟩)).trans ?_
· exact fun x h => Bool.decide_false (trList_ne_consₗ _ _ h)
convert unrev_ok using 2; simp [List.reverseAux_eq]
#align turing.partrec_to_TM2.head_main_ok Turing.PartrecToTM2.head_main_ok
theorem head_stack_ok {q s L₁ L₂ L₃} :
Reaches₁ (TM2.step tr)
⟨some (head stack q), s, K'.elim (trList L₁) [] [] (trList L₂ ++ Γ'.consₗ :: L₃)⟩
⟨some q, none, K'.elim (trList (L₂.headI :: L₁)) [] [] L₃⟩ := by
cases' L₂ with a L₂
· refine
TransGen.trans
(move_ok (by decide)
(splitAtPred_eq _ _ [] (some Γ'.consₗ) L₃ (by rintro _ ⟨⟩) ⟨rfl, rfl⟩))
(TransGen.head rfl (TransGen.head rfl ?_))
simp only [TM2.step, Option.mem_def, TM2.stepAux, ite_true, id_eq, trList, List.nil_append,
elim_update_stack, elim_rev, List.reverseAux_nil, elim_update_rev, Function.update_same,
List.headI_nil, trNat_default]
convert unrev_ok using 2
simp
· refine
TransGen.trans
(move_ok (by decide)
(splitAtPred_eq _ _ (trNat a) (some Γ'.cons) (trList L₂ ++ Γ'.consₗ :: L₃)
(trNat_natEnd _) ⟨rfl, by simp⟩))
(TransGen.head rfl (TransGen.head rfl ?_))
simp only [TM2.step, Option.mem_def, TM2.stepAux, ite_false, trList, List.append_assoc,
List.cons_append, elim_update_stack, elim_rev, elim_update_rev, Function.update_same,
List.headI_cons]
refine
TransGen.trans
(clear_ok
(splitAtPred_eq _ _ (trList L₂) (some Γ'.consₗ) L₃
(fun x h => Bool.decide_false (trList_ne_consₗ _ _ h)) ⟨rfl, by simp⟩))
?_
convert unrev_ok using 2
simp [List.reverseAux_eq]
#align turing.partrec_to_TM2.head_stack_ok Turing.PartrecToTM2.head_stack_ok
theorem succ_ok {q s n} {c d : List Γ'} :
Reaches₁ (TM2.step tr) ⟨some (Λ'.succ q), s, K'.elim (trList [n]) [] c d⟩
⟨some q, none, K'.elim (trList [n.succ]) [] c d⟩ := by
simp only [TM2.step, trList, trNat.eq_1, Nat.cast_succ, Num.add_one]
cases' (n : Num) with a
· refine TransGen.head rfl ?_
simp only [Option.mem_def, TM2.stepAux, elim_main, decide_False, elim_update_main, ne_eq,
Function.update_noteq, elim_rev, elim_update_rev, decide_True, Function.update_same,
cond_true, cond_false]
convert unrev_ok using 1
simp only [elim_update_rev, elim_rev, elim_main, List.reverseAux_nil, elim_update_main]
rfl
simp only [trNum, Num.succ, Num.succ']
suffices ∀ l₁, ∃ l₁' l₂' s',
List.reverseAux l₁ (trPosNum a.succ) = List.reverseAux l₁' l₂' ∧
Reaches₁ (TM2.step tr) ⟨some q.succ, s, K'.elim (trPosNum a ++ [Γ'.cons]) l₁ c d⟩
⟨some (unrev q), s', K'.elim (l₂' ++ [Γ'.cons]) l₁' c d⟩ by
obtain ⟨l₁', l₂', s', e, h⟩ := this []
simp? [List.reverseAux] at e says simp only [List.reverseAux] at e
refine h.trans ?_
convert unrev_ok using 2
simp [e, List.reverseAux_eq]
induction' a with m IH m _ generalizing s <;> intro l₁
· refine ⟨Γ'.bit0 :: l₁, [Γ'.bit1], some Γ'.cons, rfl, TransGen.head rfl (TransGen.single ?_)⟩
simp [trPosNum]
· obtain ⟨l₁', l₂', s', e, h⟩ := IH (Γ'.bit0 :: l₁)
refine ⟨l₁', l₂', s', e, TransGen.head ?_ h⟩
simp [PosNum.succ, trPosNum]
rfl
· refine ⟨l₁, _, some Γ'.bit0, rfl, TransGen.single ?_⟩
simp only [TM2.step, TM2.stepAux, elim_main, elim_update_main, ne_eq, Function.update_noteq,
elim_rev, elim_update_rev, Function.update_same, Option.mem_def, Option.some.injEq]
rfl
#align turing.partrec_to_TM2.succ_ok Turing.PartrecToTM2.succ_ok
theorem pred_ok (q₁ q₂ s v) (c d : List Γ') : ∃ s',
Reaches₁ (TM2.step tr) ⟨some (Λ'.pred q₁ q₂), s, K'.elim (trList v) [] c d⟩
(v.headI.rec ⟨some q₁, s', K'.elim (trList v.tail) [] c d⟩ fun n _ =>
⟨some q₂, s', K'.elim (trList (n::v.tail)) [] c d⟩) := by
rcases v with (_ | ⟨_ | n, v⟩)
· refine ⟨none, TransGen.single ?_⟩
simp
· refine ⟨some Γ'.cons, TransGen.single ?_⟩
simp
refine ⟨none, ?_⟩
simp only [TM2.step, trList, trNat.eq_1, trNum, Nat.cast_succ, Num.add_one, Num.succ,
List.tail_cons, List.headI_cons]
cases' (n : Num) with a
· simp [trPosNum, trNum, show Num.zero.succ' = PosNum.one from rfl]
refine TransGen.head rfl ?_
simp only [Option.mem_def, TM2.stepAux, elim_main, List.head?_cons, Option.some.injEq,
decide_False, List.tail_cons, elim_update_main, ne_eq, Function.update_noteq, elim_rev,
elim_update_rev, natEnd, Function.update_same, cond_true, cond_false]
convert unrev_ok using 2
simp
simp only [Num.succ']
suffices ∀ l₁, ∃ l₁' l₂' s',
List.reverseAux l₁ (trPosNum a) = List.reverseAux l₁' l₂' ∧
Reaches₁ (TM2.step tr)
⟨some (q₁.pred q₂), s, K'.elim (trPosNum a.succ ++ Γ'.cons :: trList v) l₁ c d⟩
⟨some (unrev q₂), s', K'.elim (l₂' ++ Γ'.cons :: trList v) l₁' c d⟩ by
obtain ⟨l₁', l₂', s', e, h⟩ := this []
simp only [List.reverseAux] at e
refine h.trans ?_
convert unrev_ok using 2
simp [e, List.reverseAux_eq]
induction' a with m IH m IH generalizing s <;> intro l₁
· refine ⟨Γ'.bit1::l₁, [], some Γ'.cons, rfl, TransGen.head rfl (TransGen.single ?_)⟩
simp [trPosNum, show PosNum.one.succ = PosNum.one.bit0 from rfl]
· obtain ⟨l₁', l₂', s', e, h⟩ := IH (some Γ'.bit0) (Γ'.bit1 :: l₁)
refine ⟨l₁', l₂', s', e, TransGen.head ?_ h⟩
simp
rfl
· obtain ⟨a, l, e, h⟩ : ∃ a l, (trPosNum m = a::l) ∧ natEnd a = false := by
cases m <;> refine ⟨_, _, rfl, rfl⟩
refine ⟨Γ'.bit0 :: l₁, _, some a, rfl, TransGen.single ?_⟩
simp [trPosNum, PosNum.succ, e, h, show some Γ'.bit1 ≠ some Γ'.bit0 by decide,
Option.iget, -natEnd]
rfl
#align turing.partrec_to_TM2.pred_ok Turing.PartrecToTM2.pred_ok
theorem trNormal_respects (c k v s) :
∃ b₂,
TrCfg (stepNormal c k v) b₂ ∧
Reaches₁ (TM2.step tr)
⟨some (trNormal c (trCont k)), s, K'.elim (trList v) [] [] (trContStack k)⟩ b₂ := by
induction c generalizing k v s with
| zero' => refine ⟨_, ⟨s, rfl⟩, TransGen.single ?_⟩; simp
| succ => refine ⟨_, ⟨none, rfl⟩, head_main_ok.trans succ_ok⟩
| tail =>
let o : Option Γ' := List.casesOn v none fun _ _ => some Γ'.cons
refine ⟨_, ⟨o, rfl⟩, ?_⟩; convert clear_ok _ using 2
· simp; rfl
swap
refine splitAtPred_eq _ _ (trNat v.headI) _ _ (trNat_natEnd _) ?_
cases v <;> simp [o]
| cons f fs IHf _ =>
obtain ⟨c, h₁, h₂⟩ := IHf (Cont.cons₁ fs v k) v none
refine ⟨c, h₁, TransGen.head rfl <| (move_ok (by decide) (splitAtPred_false _)).trans ?_⟩
simp only [TM2.step, Option.mem_def, elim_stack, elim_update_stack, elim_update_main, ne_eq,
Function.update_noteq, elim_main, elim_rev, elim_update_rev]
refine (copy_ok _ none [] (trList v).reverse _ _).trans ?_
convert h₂ using 2
simp [List.reverseAux_eq, trContStack]
| comp f _ _ IHg => exact IHg (Cont.comp f k) v s
| case f g IHf IHg =>
rw [stepNormal]
simp only
obtain ⟨s', h⟩ := pred_ok _ _ s v _ _
revert h; cases' v.headI with n <;> intro h
· obtain ⟨c, h₁, h₂⟩ := IHf k _ s'
exact ⟨_, h₁, h.trans h₂⟩
· obtain ⟨c, h₁, h₂⟩ := IHg k _ s'
exact ⟨_, h₁, h.trans h₂⟩
| fix f IH => apply IH
#align turing.partrec_to_TM2.tr_normal_respects Turing.PartrecToTM2.trNormal_respects
theorem tr_ret_respects (k v s) : ∃ b₂,
TrCfg (stepRet k v) b₂ ∧
Reaches₁ (TM2.step tr)
⟨some (Λ'.ret (trCont k)), s, K'.elim (trList v) [] [] (trContStack k)⟩ b₂ := by
induction k generalizing v s with
| halt => exact ⟨_, rfl, TransGen.single rfl⟩
| cons₁ fs as k _ =>
obtain ⟨s', h₁, h₂⟩ := trNormal_respects fs (Cont.cons₂ v k) as none
refine ⟨s', h₁, TransGen.head rfl ?_⟩; simp
refine (move₂_ok (by decide) ?_ (splitAtPred_false _)).trans ?_; · rfl
simp only [TM2.step, Option.mem_def, Option.elim, id_eq, elim_update_main, elim_main, elim_aux,
List.append_nil, elim_update_aux]
refine (move₂_ok (L₁ := ?_) (o := ?_) (L₂ := ?_) (by decide) rfl ?_).trans ?_
pick_goal 4
· exact splitAtPred_eq _ _ _ (some Γ'.consₗ) _
(fun x h => Bool.decide_false (trList_ne_consₗ _ _ h)) ⟨rfl, rfl⟩
refine (move₂_ok (by decide) ?_ (splitAtPred_false _)).trans ?_; · rfl
simp only [TM2.step, Option.mem_def, Option.elim, elim_update_stack, elim_main,
List.append_nil, elim_update_main, id_eq, elim_update_aux, ne_eq, Function.update_noteq,
elim_aux, elim_stack]
exact h₂
| cons₂ ns k IH =>
obtain ⟨c, h₁, h₂⟩ := IH (ns.headI :: v) none
exact ⟨c, h₁, TransGen.head rfl <| head_stack_ok.trans h₂⟩
| comp f k _ =>
obtain ⟨s', h₁, h₂⟩ := trNormal_respects f k v s
exact ⟨_, h₁, TransGen.head rfl h₂⟩
| fix f k IH =>
rw [stepRet]
have :
if v.headI = 0 then natEnd (trList v).head?.iget = true ∧ (trList v).tail = trList v.tail
else
natEnd (trList v).head?.iget = false ∧
(trList v).tail = (trNat v.headI).tail ++ Γ'.cons :: trList v.tail := by
cases' v with n
· exact ⟨rfl, rfl⟩
cases' n with n
· simp
rw [trList, List.headI, trNat, Nat.cast_succ, Num.add_one, Num.succ, List.tail]
cases (n : Num).succ' <;> exact ⟨rfl, rfl⟩
by_cases h : v.headI = 0 <;> simp only [h, ite_true, ite_false] at this ⊢
· obtain ⟨c, h₁, h₂⟩ := IH v.tail (trList v).head?
refine ⟨c, h₁, TransGen.head rfl ?_⟩
simp only [Option.mem_def, TM2.stepAux, trContStack, contStack, elim_main, this, cond_true,
elim_update_main]
exact h₂
· obtain ⟨s', h₁, h₂⟩ := trNormal_respects f (Cont.fix f k) v.tail (some Γ'.cons)
refine ⟨_, h₁, TransGen.head rfl <| TransGen.trans ?_ h₂⟩
simp only [Option.mem_def, TM2.stepAux, elim_main, this.1, cond_false, elim_update_main,
trCont]
convert clear_ok (splitAtPred_eq _ _ (trNat v.headI).tail (some Γ'.cons) _ _ _) using 2
· simp
convert rfl
· exact fun x h => trNat_natEnd _ _ (List.tail_subset _ h)
· exact ⟨rfl, this.2⟩
#align turing.partrec_to_TM2.tr_ret_respects Turing.PartrecToTM2.tr_ret_respects
theorem tr_respects : Respects step (TM2.step tr) TrCfg
| Cfg.ret _ _, _, ⟨_, rfl⟩ => tr_ret_respects _ _ _
| Cfg.halt _, _, rfl => rfl
#align turing.partrec_to_TM2.tr_respects Turing.PartrecToTM2.tr_respects
def init (c : Code) (v : List ℕ) : Cfg' :=
⟨some (trNormal c Cont'.halt), none, K'.elim (trList v) [] [] []⟩
#align turing.partrec_to_TM2.init Turing.PartrecToTM2.init
theorem tr_init (c v) :
∃ b, TrCfg (stepNormal c Cont.halt v) b ∧ Reaches₁ (TM2.step tr) (init c v) b :=
trNormal_respects _ _ _ _
#align turing.partrec_to_TM2.tr_init Turing.PartrecToTM2.tr_init
theorem tr_eval (c v) : eval (TM2.step tr) (init c v) = halt <$> Code.eval c v := by
obtain ⟨i, h₁, h₂⟩ := tr_init c v
refine Part.ext fun x => ?_
rw [reaches_eval h₂.to_reflTransGen]; simp [-TM2.step]
refine ⟨fun h => ?_, ?_⟩
· obtain ⟨c, hc₁, hc₂⟩ := tr_eval_rev tr_respects h₁ h
simp [stepNormal_eval] at hc₂
obtain ⟨v', hv, rfl⟩ := hc₂
exact ⟨_, hv, hc₁.symm⟩
· rintro ⟨v', hv, rfl⟩
have := Turing.tr_eval (b₁ := Cfg.halt v') tr_respects h₁
simp only [stepNormal_eval, Part.map_eq_map, Part.mem_map_iff, Cfg.halt.injEq,
exists_eq_right] at this
obtain ⟨_, ⟨⟩, h⟩ := this hv
exact h
#align turing.partrec_to_TM2.tr_eval Turing.PartrecToTM2.tr_eval
def trStmts₁ : Λ' → Finset Λ'
| Q@(Λ'.move _ _ _ q) => insert Q <| trStmts₁ q
| Q@(Λ'.push _ _ q) => insert Q <| trStmts₁ q
| Q@(Λ'.read q) => insert Q <| Finset.univ.biUnion fun s => trStmts₁ (q s)
| Q@(Λ'.clear _ _ q) => insert Q <| trStmts₁ q
| Q@(Λ'.copy q) => insert Q <| trStmts₁ q
| Q@(Λ'.succ q) => insert Q <| insert (unrev q) <| trStmts₁ q
| Q@(Λ'.pred q₁ q₂) => insert Q <| trStmts₁ q₁ ∪ insert (unrev q₂) (trStmts₁ q₂)
| Q@(Λ'.ret _) => {Q}
#align turing.partrec_to_TM2.tr_stmts₁ Turing.PartrecToTM2.trStmts₁
theorem trStmts₁_trans {q q'} : q' ∈ trStmts₁ q → trStmts₁ q' ⊆ trStmts₁ q := by
induction' q with _ _ _ q q_ih _ _ q q_ih q q_ih _ _ q q_ih q q_ih q q_ih q₁ q₂ q₁_ih q₂_ih _ <;>
simp (config := { contextual := true }) only [trStmts₁, Finset.mem_insert, Finset.mem_union,
or_imp, Finset.mem_singleton, Finset.Subset.refl, imp_true_iff, true_and_iff]
repeat exact fun h => Finset.Subset.trans (q_ih h) (Finset.subset_insert _ _)
· simp
intro s h x h'
simp only [Finset.mem_biUnion, Finset.mem_univ, true_and, Finset.mem_insert]
exact Or.inr ⟨_, q_ih s h h'⟩
· constructor
· rintro rfl
apply Finset.subset_insert
· intro h x h'
simp only [Finset.mem_insert]
exact Or.inr (Or.inr <| q_ih h h')
· refine ⟨fun h x h' => ?_, fun _ x h' => ?_, fun h x h' => ?_⟩ <;> simp
· exact Or.inr (Or.inr <| Or.inl <| q₁_ih h h')
· cases' Finset.mem_insert.1 h' with h' h' <;> simp [h', unrev]
· exact Or.inr (Or.inr <| Or.inr <| q₂_ih h h')
#align turing.partrec_to_TM2.tr_stmts₁_trans Turing.PartrecToTM2.trStmts₁_trans
theorem trStmts₁_self (q) : q ∈ trStmts₁ q := by
induction q <;> · first |apply Finset.mem_singleton_self|apply Finset.mem_insert_self
#align turing.partrec_to_TM2.tr_stmts₁_self Turing.PartrecToTM2.trStmts₁_self
def codeSupp' : Code → Cont' → Finset Λ'
| c@Code.zero', k => trStmts₁ (trNormal c k)
| c@Code.succ, k => trStmts₁ (trNormal c k)
| c@Code.tail, k => trStmts₁ (trNormal c k)
| c@(Code.cons f fs), k =>
trStmts₁ (trNormal c k) ∪
(codeSupp' f (Cont'.cons₁ fs k) ∪
(trStmts₁
(move₂ (fun _ => false) main aux <|
move₂ (fun s => s = Γ'.consₗ) stack main <|
move₂ (fun _ => false) aux stack <| trNormal fs (Cont'.cons₂ k)) ∪
(codeSupp' fs (Cont'.cons₂ k) ∪ trStmts₁ (head stack <| Λ'.ret k))))
| c@(Code.comp f g), k =>
trStmts₁ (trNormal c k) ∪
(codeSupp' g (Cont'.comp f k) ∪ (trStmts₁ (trNormal f k) ∪ codeSupp' f k))
| c@(Code.case f g), k => trStmts₁ (trNormal c k) ∪ (codeSupp' f k ∪ codeSupp' g k)
| c@(Code.fix f), k =>
trStmts₁ (trNormal c k) ∪
(codeSupp' f (Cont'.fix f k) ∪
(trStmts₁ (Λ'.clear natEnd main <| trNormal f (Cont'.fix f k)) ∪ {Λ'.ret k}))
#align turing.partrec_to_TM2.code_supp' Turing.PartrecToTM2.codeSupp'
@[simp]
theorem codeSupp'_self (c k) : trStmts₁ (trNormal c k) ⊆ codeSupp' c k := by
cases c <;> first | rfl | exact Finset.union_subset_left (fun _ a ↦ a)
#align turing.partrec_to_TM2.code_supp'_self Turing.PartrecToTM2.codeSupp'_self
def contSupp : Cont' → Finset Λ'
| Cont'.cons₁ fs k =>
trStmts₁
(move₂ (fun _ => false) main aux <|
move₂ (fun s => s = Γ'.consₗ) stack main <|
move₂ (fun _ => false) aux stack <| trNormal fs (Cont'.cons₂ k)) ∪
(codeSupp' fs (Cont'.cons₂ k) ∪ (trStmts₁ (head stack <| Λ'.ret k) ∪ contSupp k))
| Cont'.cons₂ k => trStmts₁ (head stack <| Λ'.ret k) ∪ contSupp k
| Cont'.comp f k => codeSupp' f k ∪ contSupp k
| Cont'.fix f k => codeSupp' (Code.fix f) k ∪ contSupp k
| Cont'.halt => ∅
#align turing.partrec_to_TM2.cont_supp Turing.PartrecToTM2.contSupp
def codeSupp (c : Code) (k : Cont') : Finset Λ' :=
codeSupp' c k ∪ contSupp k
#align turing.partrec_to_TM2.code_supp Turing.PartrecToTM2.codeSupp
@[simp]
theorem codeSupp_self (c k) : trStmts₁ (trNormal c k) ⊆ codeSupp c k :=
Finset.Subset.trans (codeSupp'_self _ _) (Finset.union_subset_left fun _ a ↦ a)
#align turing.partrec_to_TM2.code_supp_self Turing.PartrecToTM2.codeSupp_self
@[simp]
theorem codeSupp_zero (k) : codeSupp Code.zero' k = trStmts₁ (trNormal Code.zero' k) ∪ contSupp k :=
rfl
#align turing.partrec_to_TM2.code_supp_zero Turing.PartrecToTM2.codeSupp_zero
@[simp]
theorem codeSupp_succ (k) : codeSupp Code.succ k = trStmts₁ (trNormal Code.succ k) ∪ contSupp k :=
rfl
#align turing.partrec_to_TM2.code_supp_succ Turing.PartrecToTM2.codeSupp_succ
@[simp]
theorem codeSupp_tail (k) : codeSupp Code.tail k = trStmts₁ (trNormal Code.tail k) ∪ contSupp k :=
rfl
#align turing.partrec_to_TM2.code_supp_tail Turing.PartrecToTM2.codeSupp_tail
@[simp]
theorem codeSupp_cons (f fs k) :
codeSupp (Code.cons f fs) k =
trStmts₁ (trNormal (Code.cons f fs) k) ∪ codeSupp f (Cont'.cons₁ fs k) := by
simp [codeSupp, codeSupp', contSupp, Finset.union_assoc]
#align turing.partrec_to_TM2.code_supp_cons Turing.PartrecToTM2.codeSupp_cons
@[simp]
| Mathlib/Computability/TMToPartrec.lean | 1,834 | 1,839 | theorem codeSupp_comp (f g k) :
codeSupp (Code.comp f g) k =
trStmts₁ (trNormal (Code.comp f g) k) ∪ codeSupp g (Cont'.comp f k) := by |
simp only [codeSupp, codeSupp', trNormal, Finset.union_assoc, contSupp]
rw [← Finset.union_assoc _ _ (contSupp k),
Finset.union_eq_right.2 (codeSupp'_self _ _)]
|
import Mathlib.Logic.Function.Iterate
import Mathlib.Topology.EMetricSpace.Basic
import Mathlib.Tactic.GCongr
#align_import topology.metric_space.lipschitz from "leanprover-community/mathlib"@"f2ce6086713c78a7f880485f7917ea547a215982"
universe u v w x
open Filter Function Set Topology NNReal ENNReal Bornology
variable {α : Type u} {β : Type v} {γ : Type w} {ι : Type x}
def LipschitzWith [PseudoEMetricSpace α] [PseudoEMetricSpace β] (K : ℝ≥0) (f : α → β) :=
∀ x y, edist (f x) (f y) ≤ K * edist x y
#align lipschitz_with LipschitzWith
def LipschitzOnWith [PseudoEMetricSpace α] [PseudoEMetricSpace β] (K : ℝ≥0) (f : α → β)
(s : Set α) :=
∀ ⦃x⦄, x ∈ s → ∀ ⦃y⦄, y ∈ s → edist (f x) (f y) ≤ K * edist x y
#align lipschitz_on_with LipschitzOnWith
def LocallyLipschitz [PseudoEMetricSpace α] [PseudoEMetricSpace β] (f : α → β) : Prop :=
∀ x : α, ∃ K, ∃ t ∈ 𝓝 x, LipschitzOnWith K f t
@[simp]
theorem lipschitzOnWith_empty [PseudoEMetricSpace α] [PseudoEMetricSpace β] (K : ℝ≥0) (f : α → β) :
LipschitzOnWith K f ∅ := fun _ => False.elim
#align lipschitz_on_with_empty lipschitzOnWith_empty
theorem LipschitzOnWith.mono [PseudoEMetricSpace α] [PseudoEMetricSpace β] {K : ℝ≥0} {s t : Set α}
{f : α → β} (hf : LipschitzOnWith K f t) (h : s ⊆ t) : LipschitzOnWith K f s :=
fun _x x_in _y y_in => hf (h x_in) (h y_in)
#align lipschitz_on_with.mono LipschitzOnWith.mono
@[simp]
theorem lipschitzOn_univ [PseudoEMetricSpace α] [PseudoEMetricSpace β] {K : ℝ≥0} {f : α → β} :
LipschitzOnWith K f univ ↔ LipschitzWith K f := by simp [LipschitzOnWith, LipschitzWith]
#align lipschitz_on_univ lipschitzOn_univ
theorem lipschitzOnWith_iff_restrict [PseudoEMetricSpace α] [PseudoEMetricSpace β] {K : ℝ≥0}
{f : α → β} {s : Set α} : LipschitzOnWith K f s ↔ LipschitzWith K (s.restrict f) := by
simp only [LipschitzOnWith, LipschitzWith, SetCoe.forall', restrict, Subtype.edist_eq]
#align lipschitz_on_with_iff_restrict lipschitzOnWith_iff_restrict
alias ⟨LipschitzOnWith.to_restrict, _⟩ := lipschitzOnWith_iff_restrict
#align lipschitz_on_with.to_restrict LipschitzOnWith.to_restrict
theorem MapsTo.lipschitzOnWith_iff_restrict [PseudoEMetricSpace α] [PseudoEMetricSpace β] {K : ℝ≥0}
{f : α → β} {s : Set α} {t : Set β} (h : MapsTo f s t) :
LipschitzOnWith K f s ↔ LipschitzWith K (h.restrict f s t) :=
_root_.lipschitzOnWith_iff_restrict
#align maps_to.lipschitz_on_with_iff_restrict MapsTo.lipschitzOnWith_iff_restrict
alias ⟨LipschitzOnWith.to_restrict_mapsTo, _⟩ := MapsTo.lipschitzOnWith_iff_restrict
#align lipschitz_on_with.to_restrict_maps_to LipschitzOnWith.to_restrict_mapsTo
namespace LipschitzWith
open EMetric
variable [PseudoEMetricSpace α] [PseudoEMetricSpace β] [PseudoEMetricSpace γ]
variable {K : ℝ≥0} {f : α → β} {x y : α} {r : ℝ≥0∞}
protected theorem lipschitzOnWith (h : LipschitzWith K f) (s : Set α) : LipschitzOnWith K f s :=
fun x _ y _ => h x y
#align lipschitz_with.lipschitz_on_with LipschitzWith.lipschitzOnWith
theorem edist_le_mul (h : LipschitzWith K f) (x y : α) : edist (f x) (f y) ≤ K * edist x y :=
h x y
#align lipschitz_with.edist_le_mul LipschitzWith.edist_le_mul
theorem edist_le_mul_of_le (h : LipschitzWith K f) (hr : edist x y ≤ r) :
edist (f x) (f y) ≤ K * r :=
(h x y).trans <| ENNReal.mul_left_mono hr
#align lipschitz_with.edist_le_mul_of_le LipschitzWith.edist_le_mul_of_le
theorem edist_lt_mul_of_lt (h : LipschitzWith K f) (hK : K ≠ 0) (hr : edist x y < r) :
edist (f x) (f y) < K * r :=
(h x y).trans_lt <| (ENNReal.mul_lt_mul_left (ENNReal.coe_ne_zero.2 hK) ENNReal.coe_ne_top).2 hr
#align lipschitz_with.edist_lt_mul_of_lt LipschitzWith.edist_lt_mul_of_lt
theorem mapsTo_emetric_closedBall (h : LipschitzWith K f) (x : α) (r : ℝ≥0∞) :
MapsTo f (closedBall x r) (closedBall (f x) (K * r)) := fun _y hy => h.edist_le_mul_of_le hy
#align lipschitz_with.maps_to_emetric_closed_ball LipschitzWith.mapsTo_emetric_closedBall
theorem mapsTo_emetric_ball (h : LipschitzWith K f) (hK : K ≠ 0) (x : α) (r : ℝ≥0∞) :
MapsTo f (ball x r) (ball (f x) (K * r)) := fun _y hy => h.edist_lt_mul_of_lt hK hy
#align lipschitz_with.maps_to_emetric_ball LipschitzWith.mapsTo_emetric_ball
theorem edist_lt_top (hf : LipschitzWith K f) {x y : α} (h : edist x y ≠ ⊤) :
edist (f x) (f y) < ⊤ :=
(hf x y).trans_lt <| ENNReal.mul_lt_top ENNReal.coe_ne_top h
#align lipschitz_with.edist_lt_top LipschitzWith.edist_lt_top
theorem mul_edist_le (h : LipschitzWith K f) (x y : α) :
(K⁻¹ : ℝ≥0∞) * edist (f x) (f y) ≤ edist x y := by
rw [mul_comm, ← div_eq_mul_inv]
exact ENNReal.div_le_of_le_mul' (h x y)
#align lipschitz_with.mul_edist_le LipschitzWith.mul_edist_le
protected theorem of_edist_le (h : ∀ x y, edist (f x) (f y) ≤ edist x y) : LipschitzWith 1 f :=
fun x y => by simp only [ENNReal.coe_one, one_mul, h]
#align lipschitz_with.of_edist_le LipschitzWith.of_edist_le
protected theorem weaken (hf : LipschitzWith K f) {K' : ℝ≥0} (h : K ≤ K') : LipschitzWith K' f :=
fun x y => le_trans (hf x y) <| ENNReal.mul_right_mono (ENNReal.coe_le_coe.2 h)
#align lipschitz_with.weaken LipschitzWith.weaken
theorem ediam_image_le (hf : LipschitzWith K f) (s : Set α) :
EMetric.diam (f '' s) ≤ K * EMetric.diam s := by
apply EMetric.diam_le
rintro _ ⟨x, hx, rfl⟩ _ ⟨y, hy, rfl⟩
exact hf.edist_le_mul_of_le (EMetric.edist_le_diam_of_mem hx hy)
#align lipschitz_with.ediam_image_le LipschitzWith.ediam_image_le
theorem edist_lt_of_edist_lt_div (hf : LipschitzWith K f) {x y : α} {d : ℝ≥0∞}
(h : edist x y < d / K) : edist (f x) (f y) < d :=
calc
edist (f x) (f y) ≤ K * edist x y := hf x y
_ < d := ENNReal.mul_lt_of_lt_div' h
#align lipschitz_with.edist_lt_of_edist_lt_div LipschitzWith.edist_lt_of_edist_lt_div
protected theorem uniformContinuous (hf : LipschitzWith K f) : UniformContinuous f :=
EMetric.uniformContinuous_iff.2 fun ε εpos =>
⟨ε / K, ENNReal.div_pos_iff.2 ⟨ne_of_gt εpos, ENNReal.coe_ne_top⟩, hf.edist_lt_of_edist_lt_div⟩
#align lipschitz_with.uniform_continuous LipschitzWith.uniformContinuous
protected theorem continuous (hf : LipschitzWith K f) : Continuous f :=
hf.uniformContinuous.continuous
#align lipschitz_with.continuous LipschitzWith.continuous
protected theorem const (b : β) : LipschitzWith 0 fun _ : α => b := fun x y => by
simp only [edist_self, zero_le]
#align lipschitz_with.const LipschitzWith.const
protected theorem const' (b : β) {K : ℝ≥0} : LipschitzWith K fun _ : α => b := fun x y => by
simp only [edist_self, zero_le]
protected theorem id : LipschitzWith 1 (@id α) :=
LipschitzWith.of_edist_le fun _ _ => le_rfl
#align lipschitz_with.id LipschitzWith.id
protected theorem subtype_val (s : Set α) : LipschitzWith 1 (Subtype.val : s → α) :=
LipschitzWith.of_edist_le fun _ _ => le_rfl
#align lipschitz_with.subtype_val LipschitzWith.subtype_val
#align lipschitz_with.subtype_coe LipschitzWith.subtype_val
theorem subtype_mk (hf : LipschitzWith K f) {p : β → Prop} (hp : ∀ x, p (f x)) :
LipschitzWith K (fun x => ⟨f x, hp x⟩ : α → { y // p y }) :=
hf
#align lipschitz_with.subtype_mk LipschitzWith.subtype_mk
protected theorem eval {α : ι → Type u} [∀ i, PseudoEMetricSpace (α i)] [Fintype ι] (i : ι) :
LipschitzWith 1 (Function.eval i : (∀ i, α i) → α i) :=
LipschitzWith.of_edist_le fun f g => by convert edist_le_pi_edist f g i
#align lipschitz_with.eval LipschitzWith.eval
protected theorem restrict (hf : LipschitzWith K f) (s : Set α) : LipschitzWith K (s.restrict f) :=
fun x y => hf x y
#align lipschitz_with.restrict LipschitzWith.restrict
protected theorem comp {Kf Kg : ℝ≥0} {f : β → γ} {g : α → β} (hf : LipschitzWith Kf f)
(hg : LipschitzWith Kg g) : LipschitzWith (Kf * Kg) (f ∘ g) := fun x y =>
calc
edist (f (g x)) (f (g y)) ≤ Kf * edist (g x) (g y) := hf _ _
_ ≤ Kf * (Kg * edist x y) := ENNReal.mul_left_mono (hg _ _)
_ = (Kf * Kg : ℝ≥0) * edist x y := by rw [← mul_assoc, ENNReal.coe_mul]
#align lipschitz_with.comp LipschitzWith.comp
theorem comp_lipschitzOnWith {Kf Kg : ℝ≥0} {f : β → γ} {g : α → β} {s : Set α}
(hf : LipschitzWith Kf f) (hg : LipschitzOnWith Kg g s) : LipschitzOnWith (Kf * Kg) (f ∘ g) s :=
lipschitzOnWith_iff_restrict.mpr <| hf.comp hg.to_restrict
#align lipschitz_with.comp_lipschitz_on_with LipschitzWith.comp_lipschitzOnWith
protected theorem prod_fst : LipschitzWith 1 (@Prod.fst α β) :=
LipschitzWith.of_edist_le fun _ _ => le_max_left _ _
#align lipschitz_with.prod_fst LipschitzWith.prod_fst
protected theorem prod_snd : LipschitzWith 1 (@Prod.snd α β) :=
LipschitzWith.of_edist_le fun _ _ => le_max_right _ _
#align lipschitz_with.prod_snd LipschitzWith.prod_snd
protected theorem prod {f : α → β} {Kf : ℝ≥0} (hf : LipschitzWith Kf f) {g : α → γ} {Kg : ℝ≥0}
(hg : LipschitzWith Kg g) : LipschitzWith (max Kf Kg) fun x => (f x, g x) := by
intro x y
rw [ENNReal.coe_mono.map_max, Prod.edist_eq, ENNReal.max_mul]
exact max_le_max (hf x y) (hg x y)
#align lipschitz_with.prod LipschitzWith.prod
protected theorem prod_mk_left (a : α) : LipschitzWith 1 (Prod.mk a : β → α × β) := by
simpa only [max_eq_right zero_le_one] using (LipschitzWith.const a).prod LipschitzWith.id
#align lipschitz_with.prod_mk_left LipschitzWith.prod_mk_left
protected theorem prod_mk_right (b : β) : LipschitzWith 1 fun a : α => (a, b) := by
simpa only [max_eq_left zero_le_one] using LipschitzWith.id.prod (LipschitzWith.const b)
#align lipschitz_with.prod_mk_right LipschitzWith.prod_mk_right
protected theorem uncurry {f : α → β → γ} {Kα Kβ : ℝ≥0} (hα : ∀ b, LipschitzWith Kα fun a => f a b)
(hβ : ∀ a, LipschitzWith Kβ (f a)) : LipschitzWith (Kα + Kβ) (Function.uncurry f) := by
rintro ⟨a₁, b₁⟩ ⟨a₂, b₂⟩
simp only [Function.uncurry, ENNReal.coe_add, add_mul]
apply le_trans (edist_triangle _ (f a₂ b₁) _)
exact
add_le_add (le_trans (hα _ _ _) <| ENNReal.mul_left_mono <| le_max_left _ _)
(le_trans (hβ _ _ _) <| ENNReal.mul_left_mono <| le_max_right _ _)
#align lipschitz_with.uncurry LipschitzWith.uncurry
protected theorem iterate {f : α → α} (hf : LipschitzWith K f) : ∀ n, LipschitzWith (K ^ n) f^[n]
| 0 => by simpa only [pow_zero] using LipschitzWith.id
| n + 1 => by rw [pow_succ]; exact (LipschitzWith.iterate hf n).comp hf
#align lipschitz_with.iterate LipschitzWith.iterate
| Mathlib/Topology/EMetricSpace/Lipschitz.lean | 268 | 271 | theorem edist_iterate_succ_le_geometric {f : α → α} (hf : LipschitzWith K f) (x n) :
edist (f^[n] x) (f^[n + 1] x) ≤ edist x (f x) * (K : ℝ≥0∞) ^ n := by |
rw [iterate_succ, mul_comm]
simpa only [ENNReal.coe_pow] using (hf.iterate n) x (f x)
|
import Mathlib.SetTheory.Ordinal.Arithmetic
import Mathlib.SetTheory.Ordinal.Exponential
#align_import set_theory.ordinal.fixed_point from "leanprover-community/mathlib"@"0dd4319a17376eda5763cd0a7e0d35bbaaa50e83"
noncomputable section
universe u v
open Function Order
namespace Ordinal
section
variable {ι : Type u} {f : ι → Ordinal.{max u v} → Ordinal.{max u v}}
def nfpFamily (f : ι → Ordinal → Ordinal) (a : Ordinal) : Ordinal :=
sup (List.foldr f a)
#align ordinal.nfp_family Ordinal.nfpFamily
theorem nfpFamily_eq_sup (f : ι → Ordinal.{max u v} → Ordinal.{max u v}) (a : Ordinal.{max u v}) :
nfpFamily.{u, v} f a = sup.{u, v} (List.foldr f a) :=
rfl
#align ordinal.nfp_family_eq_sup Ordinal.nfpFamily_eq_sup
theorem foldr_le_nfpFamily (f : ι → Ordinal → Ordinal)
(a l) : List.foldr f a l ≤ nfpFamily.{u, v} f a :=
le_sup.{u, v} _ _
#align ordinal.foldr_le_nfp_family Ordinal.foldr_le_nfpFamily
theorem le_nfpFamily (f : ι → Ordinal → Ordinal) (a) : a ≤ nfpFamily f a :=
le_sup _ []
#align ordinal.le_nfp_family Ordinal.le_nfpFamily
theorem lt_nfpFamily {a b} : a < nfpFamily.{u, v} f b ↔ ∃ l, a < List.foldr f b l :=
lt_sup.{u, v}
#align ordinal.lt_nfp_family Ordinal.lt_nfpFamily
theorem nfpFamily_le_iff {a b} : nfpFamily.{u, v} f a ≤ b ↔ ∀ l, List.foldr f a l ≤ b :=
sup_le_iff
#align ordinal.nfp_family_le_iff Ordinal.nfpFamily_le_iff
theorem nfpFamily_le {a b} : (∀ l, List.foldr f a l ≤ b) → nfpFamily.{u, v} f a ≤ b :=
sup_le.{u, v}
#align ordinal.nfp_family_le Ordinal.nfpFamily_le
theorem nfpFamily_monotone (hf : ∀ i, Monotone (f i)) : Monotone (nfpFamily.{u, v} f) :=
fun _ _ h => sup_le.{u, v} fun l => (List.foldr_monotone hf l h).trans (le_sup.{u, v} _ l)
#align ordinal.nfp_family_monotone Ordinal.nfpFamily_monotone
theorem apply_lt_nfpFamily (H : ∀ i, IsNormal (f i)) {a b} (hb : b < nfpFamily.{u, v} f a) (i) :
f i b < nfpFamily.{u, v} f a :=
let ⟨l, hl⟩ := lt_nfpFamily.1 hb
lt_sup.2 ⟨i::l, (H i).strictMono hl⟩
#align ordinal.apply_lt_nfp_family Ordinal.apply_lt_nfpFamily
theorem apply_lt_nfpFamily_iff [Nonempty ι] (H : ∀ i, IsNormal (f i)) {a b} :
(∀ i, f i b < nfpFamily.{u, v} f a) ↔ b < nfpFamily.{u, v} f a :=
⟨fun h =>
lt_nfpFamily.2 <|
let ⟨l, hl⟩ := lt_sup.1 <| h <| Classical.arbitrary ι
⟨l, ((H _).self_le b).trans_lt hl⟩,
apply_lt_nfpFamily H⟩
#align ordinal.apply_lt_nfp_family_iff Ordinal.apply_lt_nfpFamily_iff
theorem nfpFamily_le_apply [Nonempty ι] (H : ∀ i, IsNormal (f i)) {a b} :
(∃ i, nfpFamily.{u, v} f a ≤ f i b) ↔ nfpFamily.{u, v} f a ≤ b := by
rw [← not_iff_not]
push_neg
exact apply_lt_nfpFamily_iff H
#align ordinal.nfp_family_le_apply Ordinal.nfpFamily_le_apply
theorem nfpFamily_le_fp (H : ∀ i, Monotone (f i)) {a b} (ab : a ≤ b) (h : ∀ i, f i b ≤ b) :
nfpFamily.{u, v} f a ≤ b :=
sup_le fun l => by
by_cases hι : IsEmpty ι
· rwa [Unique.eq_default l]
· induction' l with i l IH generalizing a
· exact ab
exact (H i (IH ab)).trans (h i)
#align ordinal.nfp_family_le_fp Ordinal.nfpFamily_le_fp
theorem nfpFamily_fp {i} (H : IsNormal (f i)) (a) :
f i (nfpFamily.{u, v} f a) = nfpFamily.{u, v} f a := by
unfold nfpFamily
rw [@IsNormal.sup.{u, v, v} _ H _ _ ⟨[]⟩]
apply le_antisymm <;> refine Ordinal.sup_le fun l => ?_
· exact le_sup _ (i::l)
· exact (H.self_le _).trans (le_sup _ _)
#align ordinal.nfp_family_fp Ordinal.nfpFamily_fp
theorem apply_le_nfpFamily [hι : Nonempty ι] {f : ι → Ordinal → Ordinal} (H : ∀ i, IsNormal (f i))
{a b} : (∀ i, f i b ≤ nfpFamily.{u, v} f a) ↔ b ≤ nfpFamily.{u, v} f a := by
refine ⟨fun h => ?_, fun h i => ?_⟩
· cases' hι with i
exact ((H i).self_le b).trans (h i)
rw [← nfpFamily_fp (H i)]
exact (H i).monotone h
#align ordinal.apply_le_nfp_family Ordinal.apply_le_nfpFamily
theorem nfpFamily_eq_self {f : ι → Ordinal → Ordinal} {a} (h : ∀ i, f i a = a) :
nfpFamily f a = a :=
le_antisymm (sup_le fun l => by rw [List.foldr_fixed' h l]) <| le_nfpFamily f a
#align ordinal.nfp_family_eq_self Ordinal.nfpFamily_eq_self
-- Todo: This is actually a special case of the fact the intersection of club sets is a club set.
theorem fp_family_unbounded (H : ∀ i, IsNormal (f i)) :
(⋂ i, Function.fixedPoints (f i)).Unbounded (· < ·) := fun a =>
⟨nfpFamily.{u, v} f a, fun s ⟨i, hi⟩ => by
rw [← hi, mem_fixedPoints_iff]
exact nfpFamily_fp.{u, v} (H i) a, (le_nfpFamily f a).not_lt⟩
#align ordinal.fp_family_unbounded Ordinal.fp_family_unbounded
def derivFamily (f : ι → Ordinal → Ordinal) (o : Ordinal) : Ordinal :=
limitRecOn o (nfpFamily.{u, v} f 0) (fun _ IH => nfpFamily.{u, v} f (succ IH))
fun a _ => bsup.{max u v, u} a
#align ordinal.deriv_family Ordinal.derivFamily
@[simp]
theorem derivFamily_zero (f : ι → Ordinal → Ordinal) :
derivFamily.{u, v} f 0 = nfpFamily.{u, v} f 0 :=
limitRecOn_zero _ _ _
#align ordinal.deriv_family_zero Ordinal.derivFamily_zero
@[simp]
theorem derivFamily_succ (f : ι → Ordinal → Ordinal) (o) :
derivFamily.{u, v} f (succ o) = nfpFamily.{u, v} f (succ (derivFamily.{u, v} f o)) :=
limitRecOn_succ _ _ _ _
#align ordinal.deriv_family_succ Ordinal.derivFamily_succ
theorem derivFamily_limit (f : ι → Ordinal → Ordinal) {o} :
IsLimit o → derivFamily.{u, v} f o = bsup.{max u v, u} o fun a _ => derivFamily.{u, v} f a :=
limitRecOn_limit _ _ _ _
#align ordinal.deriv_family_limit Ordinal.derivFamily_limit
theorem derivFamily_isNormal (f : ι → Ordinal → Ordinal) : IsNormal (derivFamily f) :=
⟨fun o => by rw [derivFamily_succ, ← succ_le_iff]; apply le_nfpFamily, fun o l a => by
rw [derivFamily_limit _ l, bsup_le_iff]⟩
#align ordinal.deriv_family_is_normal Ordinal.derivFamily_isNormal
theorem derivFamily_fp {i} (H : IsNormal (f i)) (o : Ordinal.{max u v}) :
f i (derivFamily.{u, v} f o) = derivFamily.{u, v} f o := by
induction' o using limitRecOn with o _ o l IH
· rw [derivFamily_zero]
exact nfpFamily_fp H 0
· rw [derivFamily_succ]
exact nfpFamily_fp H _
· rw [derivFamily_limit _ l,
IsNormal.bsup.{max u v, u, max u v} H (fun a _ => derivFamily f a) l.1]
refine eq_of_forall_ge_iff fun c => ?_
simp (config := { contextual := true }) only [bsup_le_iff, IH]
#align ordinal.deriv_family_fp Ordinal.derivFamily_fp
theorem le_iff_derivFamily (H : ∀ i, IsNormal (f i)) {a} :
(∀ i, f i a ≤ a) ↔ ∃ o, derivFamily.{u, v} f o = a :=
⟨fun ha => by
suffices ∀ (o) (_ : a ≤ derivFamily.{u, v} f o), ∃ o, derivFamily.{u, v} f o = a from
this a ((derivFamily_isNormal _).self_le _)
intro o
induction' o using limitRecOn with o IH o l IH
· intro h₁
refine ⟨0, le_antisymm ?_ h₁⟩
rw [derivFamily_zero]
exact nfpFamily_le_fp (fun i => (H i).monotone) (Ordinal.zero_le _) ha
· intro h₁
rcases le_or_lt a (derivFamily.{u, v} f o) with h | h
· exact IH h
refine ⟨succ o, le_antisymm ?_ h₁⟩
rw [derivFamily_succ]
exact nfpFamily_le_fp (fun i => (H i).monotone) (succ_le_of_lt h) ha
· intro h₁
cases' eq_or_lt_of_le h₁ with h h
· exact ⟨_, h.symm⟩
rw [derivFamily_limit _ l, ← not_le, bsup_le_iff, not_forall₂] at h
exact
let ⟨o', h, hl⟩ := h
IH o' h (le_of_not_le hl),
fun ⟨o, e⟩ i => e ▸ (derivFamily_fp (H i) _).le⟩
#align ordinal.le_iff_deriv_family Ordinal.le_iff_derivFamily
theorem fp_iff_derivFamily (H : ∀ i, IsNormal (f i)) {a} :
(∀ i, f i a = a) ↔ ∃ o, derivFamily.{u, v} f o = a :=
Iff.trans ⟨fun h i => le_of_eq (h i), fun h i => (H i).le_iff_eq.1 (h i)⟩ (le_iff_derivFamily H)
#align ordinal.fp_iff_deriv_family Ordinal.fp_iff_derivFamily
theorem derivFamily_eq_enumOrd (H : ∀ i, IsNormal (f i)) :
derivFamily.{u, v} f = enumOrd (⋂ i, Function.fixedPoints (f i)) := by
rw [← eq_enumOrd _ (fp_family_unbounded.{u, v} H)]
use (derivFamily_isNormal f).strictMono
rw [Set.range_eq_iff]
refine ⟨?_, fun a ha => ?_⟩
· rintro a S ⟨i, hi⟩
rw [← hi]
exact derivFamily_fp (H i) a
rw [Set.mem_iInter] at ha
rwa [← fp_iff_derivFamily H]
#align ordinal.deriv_family_eq_enum_ord Ordinal.derivFamily_eq_enumOrd
end
section
variable {o : Ordinal.{u}} {f : ∀ b < o, Ordinal.{max u v} → Ordinal.{max u v}}
def nfpBFamily (o : Ordinal) (f : ∀ b < o, Ordinal → Ordinal) : Ordinal → Ordinal :=
nfpFamily (familyOfBFamily o f)
#align ordinal.nfp_bfamily Ordinal.nfpBFamily
theorem nfpBFamily_eq_nfpFamily {o : Ordinal} (f : ∀ b < o, Ordinal → Ordinal) :
nfpBFamily.{u, v} o f = nfpFamily.{u, v} (familyOfBFamily o f) :=
rfl
#align ordinal.nfp_bfamily_eq_nfp_family Ordinal.nfpBFamily_eq_nfpFamily
theorem foldr_le_nfpBFamily {o : Ordinal}
(f : ∀ b < o, Ordinal → Ordinal) (a l) :
List.foldr (familyOfBFamily o f) a l ≤ nfpBFamily.{u, v} o f a :=
le_sup.{u, v} _ _
#align ordinal.foldr_le_nfp_bfamily Ordinal.foldr_le_nfpBFamily
theorem le_nfpBFamily {o : Ordinal} (f : ∀ b < o, Ordinal → Ordinal) (a) :
a ≤ nfpBFamily.{u, v} o f a :=
le_sup.{u, v} _ []
#align ordinal.le_nfp_bfamily Ordinal.le_nfpBFamily
theorem lt_nfpBFamily {a b} :
a < nfpBFamily.{u, v} o f b ↔ ∃ l, a < List.foldr (familyOfBFamily o f) b l :=
lt_sup.{u, v}
#align ordinal.lt_nfp_bfamily Ordinal.lt_nfpBFamily
theorem nfpBFamily_le_iff {o : Ordinal} {f : ∀ b < o, Ordinal → Ordinal} {a b} :
nfpBFamily.{u, v} o f a ≤ b ↔ ∀ l, List.foldr (familyOfBFamily o f) a l ≤ b :=
sup_le_iff.{u, v}
#align ordinal.nfp_bfamily_le_iff Ordinal.nfpBFamily_le_iff
theorem nfpBFamily_le {o : Ordinal} {f : ∀ b < o, Ordinal → Ordinal} {a b} :
(∀ l, List.foldr (familyOfBFamily o f) a l ≤ b) → nfpBFamily.{u, v} o f a ≤ b :=
sup_le.{u, v}
#align ordinal.nfp_bfamily_le Ordinal.nfpBFamily_le
theorem nfpBFamily_monotone (hf : ∀ i hi, Monotone (f i hi)) : Monotone (nfpBFamily.{u, v} o f) :=
nfpFamily_monotone fun _ => hf _ _
#align ordinal.nfp_bfamily_monotone Ordinal.nfpBFamily_monotone
theorem apply_lt_nfpBFamily (H : ∀ i hi, IsNormal (f i hi)) {a b} (hb : b < nfpBFamily.{u, v} o f a)
(i hi) : f i hi b < nfpBFamily.{u, v} o f a := by
rw [← familyOfBFamily_enum o f]
apply apply_lt_nfpFamily (fun _ => H _ _) hb
#align ordinal.apply_lt_nfp_bfamily Ordinal.apply_lt_nfpBFamily
theorem apply_lt_nfpBFamily_iff (ho : o ≠ 0) (H : ∀ i hi, IsNormal (f i hi)) {a b} :
(∀ i hi, f i hi b < nfpBFamily.{u, v} o f a) ↔ b < nfpBFamily.{u, v} o f a :=
⟨fun h => by
haveI := out_nonempty_iff_ne_zero.2 ho
refine (apply_lt_nfpFamily_iff.{u, v} ?_).1 fun _ => h _ _
exact fun _ => H _ _, apply_lt_nfpBFamily H⟩
#align ordinal.apply_lt_nfp_bfamily_iff Ordinal.apply_lt_nfpBFamily_iff
theorem nfpBFamily_le_apply (ho : o ≠ 0) (H : ∀ i hi, IsNormal (f i hi)) {a b} :
(∃ i hi, nfpBFamily.{u, v} o f a ≤ f i hi b) ↔ nfpBFamily.{u, v} o f a ≤ b := by
rw [← not_iff_not]
push_neg
exact apply_lt_nfpBFamily_iff.{u, v} ho H
#align ordinal.nfp_bfamily_le_apply Ordinal.nfpBFamily_le_apply
theorem nfpBFamily_le_fp (H : ∀ i hi, Monotone (f i hi)) {a b} (ab : a ≤ b)
(h : ∀ i hi, f i hi b ≤ b) : nfpBFamily.{u, v} o f a ≤ b :=
nfpFamily_le_fp (fun _ => H _ _) ab fun _ => h _ _
#align ordinal.nfp_bfamily_le_fp Ordinal.nfpBFamily_le_fp
theorem nfpBFamily_fp {i hi} (H : IsNormal (f i hi)) (a) :
f i hi (nfpBFamily.{u, v} o f a) = nfpBFamily.{u, v} o f a := by
rw [← familyOfBFamily_enum o f]
apply nfpFamily_fp
rw [familyOfBFamily_enum]
exact H
#align ordinal.nfp_bfamily_fp Ordinal.nfpBFamily_fp
theorem apply_le_nfpBFamily (ho : o ≠ 0) (H : ∀ i hi, IsNormal (f i hi)) {a b} :
(∀ i hi, f i hi b ≤ nfpBFamily.{u, v} o f a) ↔ b ≤ nfpBFamily.{u, v} o f a := by
refine ⟨fun h => ?_, fun h i hi => ?_⟩
· have ho' : 0 < o := Ordinal.pos_iff_ne_zero.2 ho
exact ((H 0 ho').self_le b).trans (h 0 ho')
· rw [← nfpBFamily_fp (H i hi)]
exact (H i hi).monotone h
#align ordinal.apply_le_nfp_bfamily Ordinal.apply_le_nfpBFamily
theorem nfpBFamily_eq_self {a} (h : ∀ i hi, f i hi a = a) : nfpBFamily.{u, v} o f a = a :=
nfpFamily_eq_self fun _ => h _ _
#align ordinal.nfp_bfamily_eq_self Ordinal.nfpBFamily_eq_self
theorem fp_bfamily_unbounded (H : ∀ i hi, IsNormal (f i hi)) :
(⋂ (i) (hi), Function.fixedPoints (f i hi)).Unbounded (· < ·) := fun a =>
⟨nfpBFamily.{u, v} _ f a, by
rw [Set.mem_iInter₂]
exact fun i hi => nfpBFamily_fp (H i hi) _, (le_nfpBFamily f a).not_lt⟩
#align ordinal.fp_bfamily_unbounded Ordinal.fp_bfamily_unbounded
def derivBFamily (o : Ordinal) (f : ∀ b < o, Ordinal → Ordinal) : Ordinal → Ordinal :=
derivFamily (familyOfBFamily o f)
#align ordinal.deriv_bfamily Ordinal.derivBFamily
theorem derivBFamily_eq_derivFamily {o : Ordinal} (f : ∀ b < o, Ordinal → Ordinal) :
derivBFamily.{u, v} o f = derivFamily.{u, v} (familyOfBFamily o f) :=
rfl
#align ordinal.deriv_bfamily_eq_deriv_family Ordinal.derivBFamily_eq_derivFamily
theorem derivBFamily_isNormal {o : Ordinal} (f : ∀ b < o, Ordinal → Ordinal) :
IsNormal (derivBFamily o f) :=
derivFamily_isNormal _
#align ordinal.deriv_bfamily_is_normal Ordinal.derivBFamily_isNormal
theorem derivBFamily_fp {i hi} (H : IsNormal (f i hi)) (a : Ordinal) :
f i hi (derivBFamily.{u, v} o f a) = derivBFamily.{u, v} o f a := by
rw [← familyOfBFamily_enum o f]
apply derivFamily_fp
rw [familyOfBFamily_enum]
exact H
#align ordinal.deriv_bfamily_fp Ordinal.derivBFamily_fp
theorem le_iff_derivBFamily (H : ∀ i hi, IsNormal (f i hi)) {a} :
(∀ i hi, f i hi a ≤ a) ↔ ∃ b, derivBFamily.{u, v} o f b = a := by
unfold derivBFamily
rw [← le_iff_derivFamily]
· refine ⟨fun h i => h _ _, fun h i hi => ?_⟩
rw [← familyOfBFamily_enum o f]
apply h
· exact fun _ => H _ _
#align ordinal.le_iff_deriv_bfamily Ordinal.le_iff_derivBFamily
theorem fp_iff_derivBFamily (H : ∀ i hi, IsNormal (f i hi)) {a} :
(∀ i hi, f i hi a = a) ↔ ∃ b, derivBFamily.{u, v} o f b = a := by
rw [← le_iff_derivBFamily H]
refine ⟨fun h i hi => le_of_eq (h i hi), fun h i hi => ?_⟩
rw [← (H i hi).le_iff_eq]
exact h i hi
#align ordinal.fp_iff_deriv_bfamily Ordinal.fp_iff_derivBFamily
theorem derivBFamily_eq_enumOrd (H : ∀ i hi, IsNormal (f i hi)) :
derivBFamily.{u, v} o f = enumOrd (⋂ (i) (hi), Function.fixedPoints (f i hi)) := by
rw [← eq_enumOrd _ (fp_bfamily_unbounded.{u, v} H)]
use (derivBFamily_isNormal f).strictMono
rw [Set.range_eq_iff]
refine ⟨fun a => Set.mem_iInter₂.2 fun i hi => derivBFamily_fp (H i hi) a, fun a ha => ?_⟩
rw [Set.mem_iInter₂] at ha
rwa [← fp_iff_derivBFamily H]
#align ordinal.deriv_bfamily_eq_enum_ord Ordinal.derivBFamily_eq_enumOrd
end
section
variable {f : Ordinal.{u} → Ordinal.{u}}
def nfp (f : Ordinal → Ordinal) : Ordinal → Ordinal :=
nfpFamily fun _ : Unit => f
#align ordinal.nfp Ordinal.nfp
theorem nfp_eq_nfpFamily (f : Ordinal → Ordinal) : nfp f = nfpFamily fun _ : Unit => f :=
rfl
#align ordinal.nfp_eq_nfp_family Ordinal.nfp_eq_nfpFamily
@[simp]
theorem sup_iterate_eq_nfp (f : Ordinal.{u} → Ordinal.{u}) :
(fun a => sup fun n : ℕ => f^[n] a) = nfp f := by
refine funext fun a => le_antisymm ?_ (sup_le fun l => ?_)
· rw [sup_le_iff]
intro n
rw [← List.length_replicate n Unit.unit, ← List.foldr_const f a]
apply le_sup
· rw [List.foldr_const f a l]
exact le_sup _ _
#align ordinal.sup_iterate_eq_nfp Ordinal.sup_iterate_eq_nfp
theorem iterate_le_nfp (f a n) : f^[n] a ≤ nfp f a := by
rw [← sup_iterate_eq_nfp]
exact le_sup _ n
#align ordinal.iterate_le_nfp Ordinal.iterate_le_nfp
theorem le_nfp (f a) : a ≤ nfp f a :=
iterate_le_nfp f a 0
#align ordinal.le_nfp Ordinal.le_nfp
theorem lt_nfp {a b} : a < nfp f b ↔ ∃ n, a < f^[n] b := by
rw [← sup_iterate_eq_nfp]
exact lt_sup
#align ordinal.lt_nfp Ordinal.lt_nfp
theorem nfp_le_iff {a b} : nfp f a ≤ b ↔ ∀ n, f^[n] a ≤ b := by
rw [← sup_iterate_eq_nfp]
exact sup_le_iff
#align ordinal.nfp_le_iff Ordinal.nfp_le_iff
theorem nfp_le {a b} : (∀ n, f^[n] a ≤ b) → nfp f a ≤ b :=
nfp_le_iff.2
#align ordinal.nfp_le Ordinal.nfp_le
@[simp]
theorem nfp_id : nfp id = id :=
funext fun a => by
simp_rw [← sup_iterate_eq_nfp, iterate_id]
exact sup_const a
#align ordinal.nfp_id Ordinal.nfp_id
theorem nfp_monotone (hf : Monotone f) : Monotone (nfp f) :=
nfpFamily_monotone fun _ => hf
#align ordinal.nfp_monotone Ordinal.nfp_monotone
theorem IsNormal.apply_lt_nfp {f} (H : IsNormal f) {a b} : f b < nfp f a ↔ b < nfp f a := by
unfold nfp
rw [← @apply_lt_nfpFamily_iff Unit (fun _ => f) _ (fun _ => H) a b]
exact ⟨fun h _ => h, fun h => h Unit.unit⟩
#align ordinal.is_normal.apply_lt_nfp Ordinal.IsNormal.apply_lt_nfp
theorem IsNormal.nfp_le_apply {f} (H : IsNormal f) {a b} : nfp f a ≤ f b ↔ nfp f a ≤ b :=
le_iff_le_iff_lt_iff_lt.2 H.apply_lt_nfp
#align ordinal.is_normal.nfp_le_apply Ordinal.IsNormal.nfp_le_apply
theorem nfp_le_fp {f} (H : Monotone f) {a b} (ab : a ≤ b) (h : f b ≤ b) : nfp f a ≤ b :=
nfpFamily_le_fp (fun _ => H) ab fun _ => h
#align ordinal.nfp_le_fp Ordinal.nfp_le_fp
theorem IsNormal.nfp_fp {f} (H : IsNormal f) : ∀ a, f (nfp f a) = nfp f a :=
@nfpFamily_fp Unit (fun _ => f) Unit.unit H
#align ordinal.is_normal.nfp_fp Ordinal.IsNormal.nfp_fp
theorem IsNormal.apply_le_nfp {f} (H : IsNormal f) {a b} : f b ≤ nfp f a ↔ b ≤ nfp f a :=
⟨le_trans (H.self_le _), fun h => by simpa only [H.nfp_fp] using H.le_iff.2 h⟩
#align ordinal.is_normal.apply_le_nfp Ordinal.IsNormal.apply_le_nfp
theorem nfp_eq_self {f : Ordinal → Ordinal} {a} (h : f a = a) : nfp f a = a :=
nfpFamily_eq_self fun _ => h
#align ordinal.nfp_eq_self Ordinal.nfp_eq_self
theorem fp_unbounded (H : IsNormal f) : (Function.fixedPoints f).Unbounded (· < ·) := by
convert fp_family_unbounded fun _ : Unit => H
exact (Set.iInter_const _).symm
#align ordinal.fp_unbounded Ordinal.fp_unbounded
def deriv (f : Ordinal → Ordinal) : Ordinal → Ordinal :=
derivFamily fun _ : Unit => f
#align ordinal.deriv Ordinal.deriv
theorem deriv_eq_derivFamily (f : Ordinal → Ordinal) : deriv f = derivFamily fun _ : Unit => f :=
rfl
#align ordinal.deriv_eq_deriv_family Ordinal.deriv_eq_derivFamily
@[simp]
theorem deriv_zero (f) : deriv f 0 = nfp f 0 :=
derivFamily_zero _
#align ordinal.deriv_zero Ordinal.deriv_zero
@[simp]
theorem deriv_succ (f o) : deriv f (succ o) = nfp f (succ (deriv f o)) :=
derivFamily_succ _ _
#align ordinal.deriv_succ Ordinal.deriv_succ
theorem deriv_limit (f) {o} : IsLimit o → deriv f o = bsup.{u, 0} o fun a _ => deriv f a :=
derivFamily_limit _
#align ordinal.deriv_limit Ordinal.deriv_limit
theorem deriv_isNormal (f) : IsNormal (deriv f) :=
derivFamily_isNormal _
#align ordinal.deriv_is_normal Ordinal.deriv_isNormal
theorem deriv_id_of_nfp_id {f : Ordinal → Ordinal} (h : nfp f = id) : deriv f = id :=
((deriv_isNormal _).eq_iff_zero_and_succ IsNormal.refl).2 (by simp [h])
#align ordinal.deriv_id_of_nfp_id Ordinal.deriv_id_of_nfp_id
theorem IsNormal.deriv_fp {f} (H : IsNormal f) : ∀ o, f (deriv f o) = deriv f o :=
@derivFamily_fp Unit (fun _ => f) Unit.unit H
#align ordinal.is_normal.deriv_fp Ordinal.IsNormal.deriv_fp
theorem IsNormal.le_iff_deriv {f} (H : IsNormal f) {a} : f a ≤ a ↔ ∃ o, deriv f o = a := by
unfold deriv
rw [← le_iff_derivFamily fun _ : Unit => H]
exact ⟨fun h _ => h, fun h => h Unit.unit⟩
#align ordinal.is_normal.le_iff_deriv Ordinal.IsNormal.le_iff_deriv
theorem IsNormal.fp_iff_deriv {f} (H : IsNormal f) {a} : f a = a ↔ ∃ o, deriv f o = a := by
rw [← H.le_iff_eq, H.le_iff_deriv]
#align ordinal.is_normal.fp_iff_deriv Ordinal.IsNormal.fp_iff_deriv
theorem deriv_eq_enumOrd (H : IsNormal f) : deriv f = enumOrd (Function.fixedPoints f) := by
convert derivFamily_eq_enumOrd fun _ : Unit => H
exact (Set.iInter_const _).symm
#align ordinal.deriv_eq_enum_ord Ordinal.deriv_eq_enumOrd
theorem deriv_eq_id_of_nfp_eq_id {f : Ordinal → Ordinal} (h : nfp f = id) : deriv f = id :=
(IsNormal.eq_iff_zero_and_succ (deriv_isNormal _) IsNormal.refl).2 <| by simp [h]
#align ordinal.deriv_eq_id_of_nfp_eq_id Ordinal.deriv_eq_id_of_nfp_eq_id
end
@[simp]
theorem nfp_add_zero (a) : nfp (a + ·) 0 = a * omega := by
simp_rw [← sup_iterate_eq_nfp, ← sup_mul_nat]
congr; funext n
induction' n with n hn
· rw [Nat.cast_zero, mul_zero, iterate_zero_apply]
· rw [iterate_succ_apply', Nat.add_comm, Nat.cast_add, Nat.cast_one, mul_one_add, hn]
#align ordinal.nfp_add_zero Ordinal.nfp_add_zero
theorem nfp_add_eq_mul_omega {a b} (hba : b ≤ a * omega) : nfp (a + ·) b = a * omega := by
apply le_antisymm (nfp_le_fp (add_isNormal a).monotone hba _)
· rw [← nfp_add_zero]
exact nfp_monotone (add_isNormal a).monotone (Ordinal.zero_le b)
· dsimp; rw [← mul_one_add, one_add_omega]
#align ordinal.nfp_add_eq_mul_omega Ordinal.nfp_add_eq_mul_omega
theorem add_eq_right_iff_mul_omega_le {a b : Ordinal} : a + b = b ↔ a * omega ≤ b := by
refine ⟨fun h => ?_, fun h => ?_⟩
· rw [← nfp_add_zero a, ← deriv_zero]
cases' (add_isNormal a).fp_iff_deriv.1 h with c hc
rw [← hc]
exact (deriv_isNormal _).monotone (Ordinal.zero_le _)
· have := Ordinal.add_sub_cancel_of_le h
nth_rw 1 [← this]
rwa [← add_assoc, ← mul_one_add, one_add_omega]
#align ordinal.add_eq_right_iff_mul_omega_le Ordinal.add_eq_right_iff_mul_omega_le
theorem add_le_right_iff_mul_omega_le {a b : Ordinal} : a + b ≤ b ↔ a * omega ≤ b := by
rw [← add_eq_right_iff_mul_omega_le]
exact (add_isNormal a).le_iff_eq
#align ordinal.add_le_right_iff_mul_omega_le Ordinal.add_le_right_iff_mul_omega_le
theorem deriv_add_eq_mul_omega_add (a b : Ordinal.{u}) : deriv (a + ·) b = a * omega + b := by
revert b
rw [← funext_iff, IsNormal.eq_iff_zero_and_succ (deriv_isNormal _) (add_isNormal _)]
refine ⟨?_, fun a h => ?_⟩
· rw [deriv_zero, add_zero]
exact nfp_add_zero a
· rw [deriv_succ, h, add_succ]
exact nfp_eq_self (add_eq_right_iff_mul_omega_le.2 ((le_add_right _ _).trans (le_succ _)))
#align ordinal.deriv_add_eq_mul_omega_add Ordinal.deriv_add_eq_mul_omega_add
-- Porting note: commented out, doesn't seem necessary
-- local infixr:0 "^" => @Pow.pow Ordinal Ordinal Ordinal.hasPow
@[simp]
theorem nfp_mul_one {a : Ordinal} (ha : 0 < a) : nfp (a * ·) 1 = (a^omega) := by
rw [← sup_iterate_eq_nfp, ← sup_opow_nat]
· dsimp
congr
funext n
induction' n with n hn
· rw [Nat.cast_zero, opow_zero, iterate_zero_apply]
rw [iterate_succ_apply', Nat.add_comm, Nat.cast_add, Nat.cast_one, opow_add, opow_one, hn]
· exact ha
#align ordinal.nfp_mul_one Ordinal.nfp_mul_one
@[simp]
| Mathlib/SetTheory/Ordinal/FixedPoint.lean | 624 | 628 | theorem nfp_mul_zero (a : Ordinal) : nfp (a * ·) 0 = 0 := by |
rw [← Ordinal.le_zero, nfp_le_iff]
intro n
induction' n with n hn; · rfl
dsimp only; rwa [iterate_succ_apply, mul_zero]
|
import Mathlib.MeasureTheory.Measure.ProbabilityMeasure
import Mathlib.MeasureTheory.Measure.Lebesgue.Basic
import Mathlib.MeasureTheory.Integral.Layercake
import Mathlib.MeasureTheory.Integral.BoundedContinuousFunction
#align_import measure_theory.measure.portmanteau from "leanprover-community/mathlib"@"fd5edc43dc4f10b85abfe544b88f82cf13c5f844"
noncomputable section
open MeasureTheory Set Filter BoundedContinuousFunction
open scoped Topology ENNReal NNReal BoundedContinuousFunction
namespace MeasureTheory
section LimsupClosedLEAndLELiminfOpen
variable {Ω : Type*} [MeasurableSpace Ω]
theorem le_measure_compl_liminf_of_limsup_measure_le {ι : Type*} {L : Filter ι} {μ : Measure Ω}
{μs : ι → Measure Ω} [IsProbabilityMeasure μ] [∀ i, IsProbabilityMeasure (μs i)] {E : Set Ω}
(E_mble : MeasurableSet E) (h : (L.limsup fun i => μs i E) ≤ μ E) :
μ Eᶜ ≤ L.liminf fun i => μs i Eᶜ := by
rcases L.eq_or_neBot with rfl | hne
· simp only [liminf_bot, le_top]
have meas_Ec : μ Eᶜ = 1 - μ E := by
simpa only [measure_univ] using measure_compl E_mble (measure_lt_top μ E).ne
have meas_i_Ec : ∀ i, μs i Eᶜ = 1 - μs i E := by
intro i
simpa only [measure_univ] using measure_compl E_mble (measure_lt_top (μs i) E).ne
simp_rw [meas_Ec, meas_i_Ec]
have obs :
(L.liminf fun i : ι => 1 - μs i E) = L.liminf ((fun x => 1 - x) ∘ fun i : ι => μs i E) := rfl
rw [obs]
have := antitone_const_tsub.map_limsup_of_continuousAt (F := L)
(fun i => μs i E) (ENNReal.continuous_sub_left ENNReal.one_ne_top).continuousAt
simp_rw [← this]
exact antitone_const_tsub h
#align measure_theory.le_measure_compl_liminf_of_limsup_measure_le MeasureTheory.le_measure_compl_liminf_of_limsup_measure_le
theorem le_measure_liminf_of_limsup_measure_compl_le {ι : Type*} {L : Filter ι} {μ : Measure Ω}
{μs : ι → Measure Ω} [IsProbabilityMeasure μ] [∀ i, IsProbabilityMeasure (μs i)] {E : Set Ω}
(E_mble : MeasurableSet E) (h : (L.limsup fun i => μs i Eᶜ) ≤ μ Eᶜ) :
μ E ≤ L.liminf fun i => μs i E :=
compl_compl E ▸ le_measure_compl_liminf_of_limsup_measure_le (MeasurableSet.compl E_mble) h
#align measure_theory.le_measure_liminf_of_limsup_measure_compl_le MeasureTheory.le_measure_liminf_of_limsup_measure_compl_le
theorem limsup_measure_compl_le_of_le_liminf_measure {ι : Type*} {L : Filter ι} {μ : Measure Ω}
{μs : ι → Measure Ω} [IsProbabilityMeasure μ] [∀ i, IsProbabilityMeasure (μs i)] {E : Set Ω}
(E_mble : MeasurableSet E) (h : μ E ≤ L.liminf fun i => μs i E) :
(L.limsup fun i => μs i Eᶜ) ≤ μ Eᶜ := by
rcases L.eq_or_neBot with rfl | hne
· simp only [limsup_bot, bot_le]
have meas_Ec : μ Eᶜ = 1 - μ E := by
simpa only [measure_univ] using measure_compl E_mble (measure_lt_top μ E).ne
have meas_i_Ec : ∀ i, μs i Eᶜ = 1 - μs i E := by
intro i
simpa only [measure_univ] using measure_compl E_mble (measure_lt_top (μs i) E).ne
simp_rw [meas_Ec, meas_i_Ec]
have obs :
(L.limsup fun i : ι => 1 - μs i E) = L.limsup ((fun x => 1 - x) ∘ fun i : ι => μs i E) := rfl
rw [obs]
have := antitone_const_tsub.map_liminf_of_continuousAt (F := L)
(fun i => μs i E) (ENNReal.continuous_sub_left ENNReal.one_ne_top).continuousAt
simp_rw [← this]
exact antitone_const_tsub h
#align measure_theory.limsup_measure_compl_le_of_le_liminf_measure MeasureTheory.limsup_measure_compl_le_of_le_liminf_measure
theorem limsup_measure_le_of_le_liminf_measure_compl {ι : Type*} {L : Filter ι} {μ : Measure Ω}
{μs : ι → Measure Ω} [IsProbabilityMeasure μ] [∀ i, IsProbabilityMeasure (μs i)] {E : Set Ω}
(E_mble : MeasurableSet E) (h : μ Eᶜ ≤ L.liminf fun i => μs i Eᶜ) :
(L.limsup fun i => μs i E) ≤ μ E :=
compl_compl E ▸ limsup_measure_compl_le_of_le_liminf_measure (MeasurableSet.compl E_mble) h
#align measure_theory.limsup_measure_le_of_le_liminf_measure_compl MeasureTheory.limsup_measure_le_of_le_liminf_measure_compl
variable [TopologicalSpace Ω] [OpensMeasurableSpace Ω]
theorem limsup_measure_closed_le_iff_liminf_measure_open_ge {ι : Type*} {L : Filter ι}
{μ : Measure Ω} {μs : ι → Measure Ω} [IsProbabilityMeasure μ]
[∀ i, IsProbabilityMeasure (μs i)] :
(∀ F, IsClosed F → (L.limsup fun i => μs i F) ≤ μ F) ↔
∀ G, IsOpen G → μ G ≤ L.liminf fun i => μs i G := by
constructor
· intro h G G_open
exact le_measure_liminf_of_limsup_measure_compl_le
G_open.measurableSet (h Gᶜ (isClosed_compl_iff.mpr G_open))
· intro h F F_closed
exact limsup_measure_le_of_le_liminf_measure_compl
F_closed.measurableSet (h Fᶜ (isOpen_compl_iff.mpr F_closed))
#align measure_theory.limsup_measure_closed_le_iff_liminf_measure_open_ge MeasureTheory.limsup_measure_closed_le_iff_liminf_measure_open_ge
end LimsupClosedLEAndLELiminfOpen -- section
section TendstoOfNullFrontier
variable {Ω : Type*} [MeasurableSpace Ω]
| Mathlib/MeasureTheory/Measure/Portmanteau.lean | 209 | 231 | theorem tendsto_measure_of_le_liminf_measure_of_limsup_measure_le {ι : Type*} {L : Filter ι}
{μ : Measure Ω} {μs : ι → Measure Ω} {E₀ E E₁ : Set Ω} (E₀_subset : E₀ ⊆ E) (subset_E₁ : E ⊆ E₁)
(nulldiff : μ (E₁ \ E₀) = 0) (h_E₀ : μ E₀ ≤ L.liminf fun i => μs i E₀)
(h_E₁ : (L.limsup fun i => μs i E₁) ≤ μ E₁) : L.Tendsto (fun i => μs i E) (𝓝 (μ E)) := by |
apply tendsto_of_le_liminf_of_limsup_le
· have E₀_ae_eq_E : E₀ =ᵐ[μ] E :=
EventuallyLE.antisymm E₀_subset.eventuallyLE
(subset_E₁.eventuallyLE.trans (ae_le_set.mpr nulldiff))
calc
μ E = μ E₀ := measure_congr E₀_ae_eq_E.symm
_ ≤ L.liminf fun i => μs i E₀ := h_E₀
_ ≤ L.liminf fun i => μs i E :=
liminf_le_liminf (eventually_of_forall fun _ => measure_mono E₀_subset)
· have E_ae_eq_E₁ : E =ᵐ[μ] E₁ :=
EventuallyLE.antisymm subset_E₁.eventuallyLE
((ae_le_set.mpr nulldiff).trans E₀_subset.eventuallyLE)
calc
(L.limsup fun i => μs i E) ≤ L.limsup fun i => μs i E₁ :=
limsup_le_limsup (eventually_of_forall fun _ => measure_mono subset_E₁)
_ ≤ μ E₁ := h_E₁
_ = μ E := measure_congr E_ae_eq_E₁.symm
· infer_param
· infer_param
|
import Mathlib.Tactic.Linarith
import Mathlib.CategoryTheory.Skeletal
import Mathlib.Data.Fintype.Sort
import Mathlib.Order.Category.NonemptyFinLinOrd
import Mathlib.CategoryTheory.Functor.ReflectsIso
#align_import algebraic_topology.simplex_category from "leanprover-community/mathlib"@"e8ac6315bcfcbaf2d19a046719c3b553206dac75"
universe v
open CategoryTheory CategoryTheory.Limits
def SimplexCategory :=
ℕ
#align simplex_category SimplexCategory
namespace SimplexCategory
section
-- Porting note: the definition of `SimplexCategory` is made irreducible below
def mk (n : ℕ) : SimplexCategory :=
n
#align simplex_category.mk SimplexCategory.mk
scoped[Simplicial] notation "[" n "]" => SimplexCategory.mk n
-- TODO: Make `len` irreducible.
def len (n : SimplexCategory) : ℕ :=
n
#align simplex_category.len SimplexCategory.len
@[ext]
theorem ext (a b : SimplexCategory) : a.len = b.len → a = b :=
id
#align simplex_category.ext SimplexCategory.ext
attribute [irreducible] SimplexCategory
open Simplicial
@[simp]
theorem len_mk (n : ℕ) : [n].len = n :=
rfl
#align simplex_category.len_mk SimplexCategory.len_mk
@[simp]
theorem mk_len (n : SimplexCategory) : ([n.len] : SimplexCategory) = n :=
rfl
#align simplex_category.mk_len SimplexCategory.mk_len
protected def rec {F : SimplexCategory → Sort*} (h : ∀ n : ℕ, F [n]) : ∀ X, F X := fun n =>
h n.len
#align simplex_category.rec SimplexCategory.rec
-- porting note (#5171): removed @[nolint has_nonempty_instance]
protected def Hom (a b : SimplexCategory) :=
Fin (a.len + 1) →o Fin (b.len + 1)
#align simplex_category.hom SimplexCategory.Hom
instance smallCategory : SmallCategory.{0} SimplexCategory where
Hom n m := SimplexCategory.Hom n m
id m := SimplexCategory.Hom.id _
comp f g := SimplexCategory.Hom.comp g f
#align simplex_category.small_category SimplexCategory.smallCategory
@[simp]
lemma id_toOrderHom (a : SimplexCategory) :
Hom.toOrderHom (𝟙 a) = OrderHom.id := rfl
@[simp]
lemma comp_toOrderHom {a b c: SimplexCategory} (f : a ⟶ b) (g : b ⟶ c) :
(f ≫ g).toOrderHom = g.toOrderHom.comp f.toOrderHom := rfl
-- Porting note: added because `Hom.ext'` is not triggered automatically
@[ext]
theorem Hom.ext {a b : SimplexCategory} (f g : a ⟶ b) :
f.toOrderHom = g.toOrderHom → f = g :=
Hom.ext' _ _
def const (x y : SimplexCategory) (i : Fin (y.len + 1)) : x ⟶ y :=
Hom.mk <| ⟨fun _ => i, by tauto⟩
#align simplex_category.const SimplexCategory.const
@[simp]
lemma const_eq_id : const [0] [0] 0 = 𝟙 _ := by aesop
@[simp]
lemma const_apply (x y : SimplexCategory) (i : Fin (y.len + 1)) (a : Fin (x.len + 1)) :
(const x y i).toOrderHom a = i := rfl
@[simp]
theorem const_comp (x : SimplexCategory) {y z : SimplexCategory}
(f : y ⟶ z) (i : Fin (y.len + 1)) :
const x y i ≫ f = const x z (f.toOrderHom i) :=
rfl
#align simplex_category.const_comp SimplexCategory.const_comp
@[simp]
def mkHom {n m : ℕ} (f : Fin (n + 1) →o Fin (m + 1)) : ([n] : SimplexCategory) ⟶ [m] :=
SimplexCategory.Hom.mk f
#align simplex_category.mk_hom SimplexCategory.mkHom
theorem hom_zero_zero (f : ([0] : SimplexCategory) ⟶ [0]) : f = 𝟙 _ := by
ext : 3
apply @Subsingleton.elim (Fin 1)
#align simplex_category.hom_zero_zero SimplexCategory.hom_zero_zero
end
open Simplicial
section Skeleton
@[simps obj map]
def skeletalFunctor : SimplexCategory ⥤ NonemptyFinLinOrd where
obj a := NonemptyFinLinOrd.of (Fin (a.len + 1))
map f := f.toOrderHom
#align simplex_category.skeletal_functor SimplexCategory.skeletalFunctor
theorem skeletalFunctor.coe_map {Δ₁ Δ₂ : SimplexCategory} (f : Δ₁ ⟶ Δ₂) :
↑(skeletalFunctor.map f) = f.toOrderHom :=
rfl
#align simplex_category.skeletal_functor.coe_map SimplexCategory.skeletalFunctor.coe_map
theorem skeletal : Skeletal SimplexCategory := fun X Y ⟨I⟩ => by
suffices Fintype.card (Fin (X.len + 1)) = Fintype.card (Fin (Y.len + 1)) by
ext
simpa
apply Fintype.card_congr
exact ((skeletalFunctor ⋙ forget NonemptyFinLinOrd).mapIso I).toEquiv
#align simplex_category.skeletal SimplexCategory.skeletal
lemma isSkeletonOf :
IsSkeletonOf NonemptyFinLinOrd SimplexCategory skeletalFunctor where
skel := skeletal
eqv := SkeletalFunctor.isEquivalence
#align simplex_category.is_skeleton_of SimplexCategory.isSkeletonOf
def Truncated (n : ℕ) :=
FullSubcategory fun a : SimplexCategory => a.len ≤ n
#align simplex_category.truncated SimplexCategory.Truncated
instance (n : ℕ) : SmallCategory.{0} (Truncated n) :=
FullSubcategory.category _
section EpiMono
theorem mono_iff_injective {n m : SimplexCategory} {f : n ⟶ m} :
Mono f ↔ Function.Injective f.toOrderHom := by
rw [← Functor.mono_map_iff_mono skeletalEquivalence.functor]
dsimp only [skeletalEquivalence, Functor.asEquivalence_functor]
simp only [skeletalFunctor_obj, skeletalFunctor_map,
NonemptyFinLinOrd.mono_iff_injective, NonemptyFinLinOrd.coe_of]
#align simplex_category.mono_iff_injective SimplexCategory.mono_iff_injective
theorem epi_iff_surjective {n m : SimplexCategory} {f : n ⟶ m} :
Epi f ↔ Function.Surjective f.toOrderHom := by
rw [← Functor.epi_map_iff_epi skeletalEquivalence.functor]
dsimp only [skeletalEquivalence, Functor.asEquivalence_functor]
simp only [skeletalFunctor_obj, skeletalFunctor_map,
NonemptyFinLinOrd.epi_iff_surjective, NonemptyFinLinOrd.coe_of]
#align simplex_category.epi_iff_surjective SimplexCategory.epi_iff_surjective
theorem len_le_of_mono {x y : SimplexCategory} {f : x ⟶ y} : Mono f → x.len ≤ y.len := by
intro hyp_f_mono
have f_inj : Function.Injective f.toOrderHom.toFun := mono_iff_injective.1 hyp_f_mono
simpa using Fintype.card_le_of_injective f.toOrderHom.toFun f_inj
#align simplex_category.len_le_of_mono SimplexCategory.len_le_of_mono
theorem le_of_mono {n m : ℕ} {f : ([n] : SimplexCategory) ⟶ [m]} : CategoryTheory.Mono f → n ≤ m :=
len_le_of_mono
#align simplex_category.le_of_mono SimplexCategory.le_of_mono
theorem len_le_of_epi {x y : SimplexCategory} {f : x ⟶ y} : Epi f → y.len ≤ x.len := by
intro hyp_f_epi
have f_surj : Function.Surjective f.toOrderHom.toFun := epi_iff_surjective.1 hyp_f_epi
simpa using Fintype.card_le_of_surjective f.toOrderHom.toFun f_surj
#align simplex_category.len_le_of_epi SimplexCategory.len_le_of_epi
theorem le_of_epi {n m : ℕ} {f : ([n] : SimplexCategory) ⟶ [m]} : Epi f → m ≤ n :=
len_le_of_epi
#align simplex_category.le_of_epi SimplexCategory.le_of_epi
instance {n : ℕ} {i : Fin (n + 2)} : Mono (δ i) := by
rw [mono_iff_injective]
exact Fin.succAbove_right_injective
instance {n : ℕ} {i : Fin (n + 1)} : Epi (σ i) := by
rw [epi_iff_surjective]
intro b
simp only [σ, mkHom, Hom.toOrderHom_mk, OrderHom.coe_mk]
by_cases h : b ≤ i
· use b
-- This was not needed before leanprover/lean4#2644
dsimp
rw [Fin.predAbove_of_le_castSucc i b (by simpa only [Fin.coe_eq_castSucc] using h)]
simp only [len_mk, Fin.coe_eq_castSucc, Fin.castPred_castSucc]
· use b.succ
-- This was not needed before leanprover/lean4#2644
dsimp
rw [Fin.predAbove_of_castSucc_lt i b.succ _, Fin.pred_succ]
rw [not_le] at h
rw [Fin.lt_iff_val_lt_val] at h ⊢
simpa only [Fin.val_succ, Fin.coe_castSucc] using Nat.lt.step h
instance : (forget SimplexCategory).ReflectsIsomorphisms :=
⟨fun f hf =>
Iso.isIso_hom
{ hom := f
inv := Hom.mk
{ toFun := inv ((forget SimplexCategory).map f)
monotone' := fun y₁ y₂ h => by
by_cases h' : y₁ < y₂
· by_contra h''
apply not_le.mpr h'
convert f.toOrderHom.monotone (le_of_not_ge h'')
all_goals
exact (congr_hom (Iso.inv_hom_id
(asIso ((forget SimplexCategory).map f))) _).symm
· rw [eq_of_le_of_not_lt h h'] }
hom_inv_id := by
ext1
ext1
exact Iso.hom_inv_id (asIso ((forget _).map f))
inv_hom_id := by
ext1
ext1
exact Iso.inv_hom_id (asIso ((forget _).map f)) }⟩
theorem isIso_of_bijective {x y : SimplexCategory} {f : x ⟶ y}
(hf : Function.Bijective f.toOrderHom.toFun) : IsIso f :=
haveI : IsIso ((forget SimplexCategory).map f) := (isIso_iff_bijective _).mpr hf
isIso_of_reflects_iso f (forget SimplexCategory)
#align simplex_category.is_iso_of_bijective SimplexCategory.isIso_of_bijective
@[simp]
def orderIsoOfIso {x y : SimplexCategory} (e : x ≅ y) : Fin (x.len + 1) ≃o Fin (y.len + 1) :=
Equiv.toOrderIso
{ toFun := e.hom.toOrderHom
invFun := e.inv.toOrderHom
left_inv := fun i => by
simpa only using congr_arg (fun φ => (Hom.toOrderHom φ) i) e.hom_inv_id
right_inv := fun i => by
simpa only using congr_arg (fun φ => (Hom.toOrderHom φ) i) e.inv_hom_id }
e.hom.toOrderHom.monotone e.inv.toOrderHom.monotone
#align simplex_category.order_iso_of_iso SimplexCategory.orderIsoOfIso
theorem iso_eq_iso_refl {x : SimplexCategory} (e : x ≅ x) : e = Iso.refl x := by
have h : (Finset.univ : Finset (Fin (x.len + 1))).card = x.len + 1 := Finset.card_fin (x.len + 1)
have eq₁ := Finset.orderEmbOfFin_unique' h fun i => Finset.mem_univ ((orderIsoOfIso e) i)
have eq₂ :=
Finset.orderEmbOfFin_unique' h fun i => Finset.mem_univ ((orderIsoOfIso (Iso.refl x)) i)
-- Porting note: the proof was rewritten from this point in #3414 (reenableeta)
-- It could be investigated again to see if the original can be restored.
ext x
replace eq₁ := congr_arg (· x) eq₁
replace eq₂ := congr_arg (· x) eq₂.symm
simp_all
#align simplex_category.iso_eq_iso_refl SimplexCategory.iso_eq_iso_refl
theorem eq_id_of_isIso {x : SimplexCategory} (f : x ⟶ x) [IsIso f] : f = 𝟙 _ :=
congr_arg (fun φ : _ ≅ _ => φ.hom) (iso_eq_iso_refl (asIso f))
#align simplex_category.eq_id_of_is_iso SimplexCategory.eq_id_of_isIso
theorem eq_σ_comp_of_not_injective' {n : ℕ} {Δ' : SimplexCategory} (θ : mk (n + 1) ⟶ Δ')
(i : Fin (n + 1)) (hi : θ.toOrderHom (Fin.castSucc i) = θ.toOrderHom i.succ) :
∃ θ' : mk n ⟶ Δ', θ = σ i ≫ θ' := by
use δ i.succ ≫ θ
ext1; ext1; ext1 x
simp only [len_mk, σ, mkHom, comp_toOrderHom, Hom.toOrderHom_mk, OrderHom.comp_coe,
OrderHom.coe_mk, Function.comp_apply]
by_cases h' : x ≤ Fin.castSucc i
· -- This was not needed before leanprover/lean4#2644
dsimp
rw [Fin.predAbove_of_le_castSucc i x h']
dsimp [δ]
erw [Fin.succAbove_of_castSucc_lt _ _ _]
· rw [Fin.castSucc_castPred]
· exact (Fin.castSucc_lt_succ_iff.mpr h')
· simp only [not_le] at h'
let y := x.pred <| by rintro (rfl : x = 0); simp at h'
have hy : x = y.succ := (Fin.succ_pred x _).symm
rw [hy] at h' ⊢
-- This was not needed before leanprover/lean4#2644
conv_rhs => dsimp
rw [Fin.predAbove_of_castSucc_lt i y.succ h', Fin.pred_succ]
by_cases h'' : y = i
· rw [h'']
refine hi.symm.trans ?_
congr 1
dsimp [δ]
erw [Fin.succAbove_of_castSucc_lt i.succ]
exact Fin.lt_succ
· dsimp [δ]
erw [Fin.succAbove_of_le_castSucc i.succ _]
simp only [Fin.lt_iff_val_lt_val, Fin.le_iff_val_le_val, Fin.val_succ, Fin.coe_castSucc,
Nat.lt_succ_iff, Fin.ext_iff] at h' h'' ⊢
cases' Nat.le.dest h' with c hc
cases c
· exfalso
simp only [Nat.zero_eq, add_zero, len_mk, Fin.coe_pred, ge_iff_le] at hc
rw [hc] at h''
exact h'' rfl
· rw [← hc]
simp only [add_le_add_iff_left, Nat.succ_eq_add_one, le_add_iff_nonneg_left, zero_le]
#align simplex_category.eq_σ_comp_of_not_injective' SimplexCategory.eq_σ_comp_of_not_injective'
theorem eq_σ_comp_of_not_injective {n : ℕ} {Δ' : SimplexCategory} (θ : mk (n + 1) ⟶ Δ')
(hθ : ¬Function.Injective θ.toOrderHom) :
∃ (i : Fin (n + 1)) (θ' : mk n ⟶ Δ'), θ = σ i ≫ θ' := by
simp only [Function.Injective, exists_prop, not_forall] at hθ
-- as θ is not injective, there exists `x<y` such that `θ x = θ y`
-- and then, `θ x = θ (x+1)`
have hθ₂ : ∃ x y : Fin (n + 2), (Hom.toOrderHom θ) x = (Hom.toOrderHom θ) y ∧ x < y := by
rcases hθ with ⟨x, y, ⟨h₁, h₂⟩⟩
by_cases h : x < y
· exact ⟨x, y, ⟨h₁, h⟩⟩
· refine ⟨y, x, ⟨h₁.symm, ?_⟩⟩
rcases lt_or_eq_of_le (not_lt.mp h) with h' | h'
· exact h'
· exfalso
exact h₂ h'.symm
rcases hθ₂ with ⟨x, y, ⟨h₁, h₂⟩⟩
use x.castPred ((Fin.le_last _).trans_lt' h₂).ne
apply eq_σ_comp_of_not_injective'
apply le_antisymm
· exact θ.toOrderHom.monotone (le_of_lt (Fin.castSucc_lt_succ _))
· rw [Fin.castSucc_castPred, h₁]
exact θ.toOrderHom.monotone ((Fin.succ_castPred_le_iff _).mpr h₂)
#align simplex_category.eq_σ_comp_of_not_injective SimplexCategory.eq_σ_comp_of_not_injective
theorem eq_comp_δ_of_not_surjective' {n : ℕ} {Δ : SimplexCategory} (θ : Δ ⟶ mk (n + 1))
(i : Fin (n + 2)) (hi : ∀ x, θ.toOrderHom x ≠ i) : ∃ θ' : Δ ⟶ mk n, θ = θ' ≫ δ i := by
by_cases h : i < Fin.last (n + 1)
· use θ ≫ σ (Fin.castPred i h.ne)
ext1
ext1
ext1 x
simp only [len_mk, Category.assoc, comp_toOrderHom, OrderHom.comp_coe, Function.comp_apply]
by_cases h' : θ.toOrderHom x ≤ i
· simp only [σ, mkHom, Hom.toOrderHom_mk, OrderHom.coe_mk]
-- This used to be `rw`, but we need `erw` after leanprover/lean4#2644
erw [Fin.predAbove_of_le_castSucc _ _ (by rwa [Fin.castSucc_castPred])]
dsimp [δ]
erw [Fin.succAbove_of_castSucc_lt i]
· rw [Fin.castSucc_castPred]
· rw [(hi x).le_iff_lt] at h'
exact h'
· simp only [not_le] at h'
dsimp [σ, δ]
erw [Fin.predAbove_of_castSucc_lt _ _ (by rwa [Fin.castSucc_castPred])]
rw [Fin.succAbove_of_le_castSucc i _]
· erw [Fin.succ_pred]
· exact Nat.le_sub_one_of_lt (Fin.lt_iff_val_lt_val.mp h')
· obtain rfl := le_antisymm (Fin.le_last i) (not_lt.mp h)
use θ ≫ σ (Fin.last _)
ext x : 3
dsimp [δ, σ]
simp_rw [Fin.succAbove_last, Fin.predAbove_last_apply]
erw [dif_neg (hi x)]
rw [Fin.castSucc_castPred]
#align simplex_category.eq_comp_δ_of_not_surjective' SimplexCategory.eq_comp_δ_of_not_surjective'
theorem eq_comp_δ_of_not_surjective {n : ℕ} {Δ : SimplexCategory} (θ : Δ ⟶ mk (n + 1))
(hθ : ¬Function.Surjective θ.toOrderHom) :
∃ (i : Fin (n + 2)) (θ' : Δ ⟶ mk n), θ = θ' ≫ δ i := by
cases' not_forall.mp hθ with i hi
use i
exact eq_comp_δ_of_not_surjective' θ i (not_exists.mp hi)
#align simplex_category.eq_comp_δ_of_not_surjective SimplexCategory.eq_comp_δ_of_not_surjective
theorem eq_id_of_mono {x : SimplexCategory} (i : x ⟶ x) [Mono i] : i = 𝟙 _ := by
suffices IsIso i by
apply eq_id_of_isIso
apply isIso_of_bijective
dsimp
rw [Fintype.bijective_iff_injective_and_card i.toOrderHom, ← mono_iff_injective,
eq_self_iff_true, and_true_iff]
infer_instance
#align simplex_category.eq_id_of_mono SimplexCategory.eq_id_of_mono
theorem eq_id_of_epi {x : SimplexCategory} (i : x ⟶ x) [Epi i] : i = 𝟙 _ := by
suffices IsIso i by
haveI := this
apply eq_id_of_isIso
apply isIso_of_bijective
dsimp
rw [Fintype.bijective_iff_surjective_and_card i.toOrderHom, ← epi_iff_surjective,
eq_self_iff_true, and_true_iff]
infer_instance
#align simplex_category.eq_id_of_epi SimplexCategory.eq_id_of_epi
theorem eq_σ_of_epi {n : ℕ} (θ : mk (n + 1) ⟶ mk n) [Epi θ] : ∃ i : Fin (n + 1), θ = σ i := by
rcases eq_σ_comp_of_not_injective θ (by
by_contra h
simpa using le_of_mono (mono_iff_injective.mpr h)) with ⟨i, θ', h⟩
use i
haveI : Epi (σ i ≫ θ') := by
rw [← h]
infer_instance
haveI := CategoryTheory.epi_of_epi (σ i) θ'
rw [h, eq_id_of_epi θ', Category.comp_id]
#align simplex_category.eq_σ_of_epi SimplexCategory.eq_σ_of_epi
theorem eq_δ_of_mono {n : ℕ} (θ : mk n ⟶ mk (n + 1)) [Mono θ] : ∃ i : Fin (n + 2), θ = δ i := by
rcases eq_comp_δ_of_not_surjective θ (by
by_contra h
simpa using le_of_epi (epi_iff_surjective.mpr h)) with ⟨i, θ', h⟩
use i
haveI : Mono (θ' ≫ δ i) := by
rw [← h]
infer_instance
haveI := CategoryTheory.mono_of_mono θ' (δ i)
rw [h, eq_id_of_mono θ', Category.id_comp]
#align simplex_category.eq_δ_of_mono SimplexCategory.eq_δ_of_mono
theorem len_lt_of_mono {Δ' Δ : SimplexCategory} (i : Δ' ⟶ Δ) [hi : Mono i] (hi' : Δ ≠ Δ') :
Δ'.len < Δ.len := by
rcases lt_or_eq_of_le (len_le_of_mono hi) with (h | h)
· exact h
· exfalso
exact hi' (by ext; exact h.symm)
#align simplex_category.len_lt_of_mono SimplexCategory.len_lt_of_mono
noncomputable instance : SplitEpiCategory SimplexCategory :=
skeletalEquivalence.inverse.splitEpiCategoryImpOfIsEquivalence
instance : HasStrongEpiMonoFactorisations SimplexCategory :=
Functor.hasStrongEpiMonoFactorisations_imp_of_isEquivalence
SimplexCategory.skeletalEquivalence.inverse
instance : HasStrongEpiImages SimplexCategory :=
Limits.hasStrongEpiImages_of_hasStrongEpiMonoFactorisations
instance (Δ Δ' : SimplexCategory) (θ : Δ ⟶ Δ') : Epi (factorThruImage θ) :=
StrongEpi.epi
theorem image_eq {Δ Δ' Δ'' : SimplexCategory} {φ : Δ ⟶ Δ''} {e : Δ ⟶ Δ'} [Epi e] {i : Δ' ⟶ Δ''}
[Mono i] (fac : e ≫ i = φ) : image φ = Δ' := by
haveI := strongEpi_of_epi e
let e := image.isoStrongEpiMono e i fac
ext
exact
le_antisymm (len_le_of_epi (inferInstance : Epi e.hom))
(len_le_of_mono (inferInstance : Mono e.hom))
#align simplex_category.image_eq SimplexCategory.image_eq
theorem image_ι_eq {Δ Δ'' : SimplexCategory} {φ : Δ ⟶ Δ''} {e : Δ ⟶ image φ} [Epi e]
{i : image φ ⟶ Δ''} [Mono i] (fac : e ≫ i = φ) : image.ι φ = i := by
haveI := strongEpi_of_epi e
rw [← image.isoStrongEpiMono_hom_comp_ι e i fac,
SimplexCategory.eq_id_of_isIso (image.isoStrongEpiMono e i fac).hom, Category.id_comp]
#align simplex_category.image_ι_eq SimplexCategory.image_ι_eq
| Mathlib/AlgebraicTopology/SimplexCategory.lean | 865 | 867 | theorem factorThruImage_eq {Δ Δ'' : SimplexCategory} {φ : Δ ⟶ Δ''} {e : Δ ⟶ image φ} [Epi e]
{i : image φ ⟶ Δ''} [Mono i] (fac : e ≫ i = φ) : factorThruImage φ = e := by |
rw [← cancel_mono i, fac, ← image_ι_eq fac, image.fac]
|
import Mathlib.Data.Finset.Lattice
#align_import order.irreducible from "leanprover-community/mathlib"@"bf2428c9486c407ca38b5b3fb10b87dad0bc99fa"
open Finset OrderDual
variable {ι α : Type*}
section SemilatticeSup
variable [SemilatticeSup α] {a b c : α}
def SupIrred (a : α) : Prop :=
¬IsMin a ∧ ∀ ⦃b c⦄, b ⊔ c = a → b = a ∨ c = a
#align sup_irred SupIrred
def SupPrime (a : α) : Prop :=
¬IsMin a ∧ ∀ ⦃b c⦄, a ≤ b ⊔ c → a ≤ b ∨ a ≤ c
#align sup_prime SupPrime
theorem SupIrred.not_isMin (ha : SupIrred a) : ¬IsMin a :=
ha.1
#align sup_irred.not_is_min SupIrred.not_isMin
theorem SupPrime.not_isMin (ha : SupPrime a) : ¬IsMin a :=
ha.1
#align sup_prime.not_is_min SupPrime.not_isMin
theorem IsMin.not_supIrred (ha : IsMin a) : ¬SupIrred a := fun h => h.1 ha
#align is_min.not_sup_irred IsMin.not_supIrred
theorem IsMin.not_supPrime (ha : IsMin a) : ¬SupPrime a := fun h => h.1 ha
#align is_min.not_sup_prime IsMin.not_supPrime
@[simp]
theorem not_supIrred : ¬SupIrred a ↔ IsMin a ∨ ∃ b c, b ⊔ c = a ∧ b < a ∧ c < a := by
rw [SupIrred, not_and_or]
push_neg
rw [exists₂_congr]
simp (config := { contextual := true }) [@eq_comm _ _ a]
#align not_sup_irred not_supIrred
@[simp]
theorem not_supPrime : ¬SupPrime a ↔ IsMin a ∨ ∃ b c, a ≤ b ⊔ c ∧ ¬a ≤ b ∧ ¬a ≤ c := by
rw [SupPrime, not_and_or]; push_neg; rfl
#align not_sup_prime not_supPrime
protected theorem SupPrime.supIrred : SupPrime a → SupIrred a :=
And.imp_right fun h b c ha => by simpa [← ha] using h ha.ge
#align sup_prime.sup_irred SupPrime.supIrred
theorem SupPrime.le_sup (ha : SupPrime a) : a ≤ b ⊔ c ↔ a ≤ b ∨ a ≤ c :=
⟨fun h => ha.2 h, fun h => h.elim le_sup_of_le_left le_sup_of_le_right⟩
#align sup_prime.le_sup SupPrime.le_sup
variable [OrderBot α] {s : Finset ι} {f : ι → α}
@[simp]
theorem not_supIrred_bot : ¬SupIrred (⊥ : α) :=
isMin_bot.not_supIrred
#align not_sup_irred_bot not_supIrred_bot
@[simp]
theorem not_supPrime_bot : ¬SupPrime (⊥ : α) :=
isMin_bot.not_supPrime
#align not_sup_prime_bot not_supPrime_bot
theorem SupIrred.ne_bot (ha : SupIrred a) : a ≠ ⊥ := by rintro rfl; exact not_supIrred_bot ha
#align sup_irred.ne_bot SupIrred.ne_bot
theorem SupPrime.ne_bot (ha : SupPrime a) : a ≠ ⊥ := by rintro rfl; exact not_supPrime_bot ha
#align sup_prime.ne_bot SupPrime.ne_bot
| Mathlib/Order/Irreducible.lean | 110 | 116 | theorem SupIrred.finset_sup_eq (ha : SupIrred a) (h : s.sup f = a) : ∃ i ∈ s, f i = a := by |
classical
induction' s using Finset.induction with i s _ ih
· simpa [ha.ne_bot] using h.symm
simp only [exists_prop, exists_mem_insert] at ih ⊢
rw [sup_insert] at h
exact (ha.2 h).imp_right ih
|
import Mathlib.Data.Finset.Image
#align_import data.finset.card from "leanprover-community/mathlib"@"65a1391a0106c9204fe45bc73a039f056558cb83"
assert_not_exists MonoidWithZero
-- TODO: After a lot more work,
-- assert_not_exists OrderedCommMonoid
open Function Multiset Nat
variable {α β R : Type*}
namespace Finset
variable {s t : Finset α} {a b : α}
def card (s : Finset α) : ℕ :=
Multiset.card s.1
#align finset.card Finset.card
theorem card_def (s : Finset α) : s.card = Multiset.card s.1 :=
rfl
#align finset.card_def Finset.card_def
@[simp] lemma card_val (s : Finset α) : Multiset.card s.1 = s.card := rfl
#align finset.card_val Finset.card_val
@[simp]
theorem card_mk {m nodup} : (⟨m, nodup⟩ : Finset α).card = Multiset.card m :=
rfl
#align finset.card_mk Finset.card_mk
@[simp]
theorem card_empty : card (∅ : Finset α) = 0 :=
rfl
#align finset.card_empty Finset.card_empty
@[gcongr]
theorem card_le_card : s ⊆ t → s.card ≤ t.card :=
Multiset.card_le_card ∘ val_le_iff.mpr
#align finset.card_le_of_subset Finset.card_le_card
@[mono]
theorem card_mono : Monotone (@card α) := by apply card_le_card
#align finset.card_mono Finset.card_mono
@[simp] lemma card_eq_zero : s.card = 0 ↔ s = ∅ := card_eq_zero.trans val_eq_zero
lemma card_ne_zero : s.card ≠ 0 ↔ s.Nonempty := card_eq_zero.ne.trans nonempty_iff_ne_empty.symm
lemma card_pos : 0 < s.card ↔ s.Nonempty := Nat.pos_iff_ne_zero.trans card_ne_zero
#align finset.card_eq_zero Finset.card_eq_zero
#align finset.card_pos Finset.card_pos
alias ⟨_, Nonempty.card_pos⟩ := card_pos
alias ⟨_, Nonempty.card_ne_zero⟩ := card_ne_zero
#align finset.nonempty.card_pos Finset.Nonempty.card_pos
theorem card_ne_zero_of_mem (h : a ∈ s) : s.card ≠ 0 :=
(not_congr card_eq_zero).2 <| ne_empty_of_mem h
#align finset.card_ne_zero_of_mem Finset.card_ne_zero_of_mem
@[simp]
theorem card_singleton (a : α) : card ({a} : Finset α) = 1 :=
Multiset.card_singleton _
#align finset.card_singleton Finset.card_singleton
theorem card_singleton_inter [DecidableEq α] : ({a} ∩ s).card ≤ 1 := by
cases' Finset.decidableMem a s with h h
· simp [Finset.singleton_inter_of_not_mem h]
· simp [Finset.singleton_inter_of_mem h]
#align finset.card_singleton_inter Finset.card_singleton_inter
@[simp]
theorem card_cons (h : a ∉ s) : (s.cons a h).card = s.card + 1 :=
Multiset.card_cons _ _
#align finset.card_cons Finset.card_cons
namespace Finset
variable {s t : Finset α} {f : α → β} {n : ℕ}
@[simp]
theorem length_toList (s : Finset α) : s.toList.length = s.card := by
rw [toList, ← Multiset.coe_card, Multiset.coe_toList, card_def]
#align finset.length_to_list Finset.length_toList
theorem card_image_le [DecidableEq β] : (s.image f).card ≤ s.card := by
simpa only [card_map] using (s.1.map f).toFinset_card_le
#align finset.card_image_le Finset.card_image_le
theorem card_image_of_injOn [DecidableEq β] (H : Set.InjOn f s) : (s.image f).card = s.card := by
simp only [card, image_val_of_injOn H, card_map]
#align finset.card_image_of_inj_on Finset.card_image_of_injOn
theorem injOn_of_card_image_eq [DecidableEq β] (H : (s.image f).card = s.card) : Set.InjOn f s := by
rw [card_def, card_def, image, toFinset] at H
dsimp only at H
have : (s.1.map f).dedup = s.1.map f := by
refine Multiset.eq_of_le_of_card_le (Multiset.dedup_le _) ?_
simp only [H, Multiset.card_map, le_rfl]
rw [Multiset.dedup_eq_self] at this
exact inj_on_of_nodup_map this
#align finset.inj_on_of_card_image_eq Finset.injOn_of_card_image_eq
theorem card_image_iff [DecidableEq β] : (s.image f).card = s.card ↔ Set.InjOn f s :=
⟨injOn_of_card_image_eq, card_image_of_injOn⟩
#align finset.card_image_iff Finset.card_image_iff
theorem card_image_of_injective [DecidableEq β] (s : Finset α) (H : Injective f) :
(s.image f).card = s.card :=
card_image_of_injOn fun _ _ _ _ h => H h
#align finset.card_image_of_injective Finset.card_image_of_injective
theorem fiber_card_ne_zero_iff_mem_image (s : Finset α) (f : α → β) [DecidableEq β] (y : β) :
(s.filter fun x => f x = y).card ≠ 0 ↔ y ∈ s.image f := by
rw [← Nat.pos_iff_ne_zero, card_pos, fiber_nonempty_iff_mem_image]
#align finset.fiber_card_ne_zero_iff_mem_image Finset.fiber_card_ne_zero_iff_mem_image
lemma card_filter_le_iff (s : Finset α) (P : α → Prop) [DecidablePred P] (n : ℕ) :
(s.filter P).card ≤ n ↔ ∀ s' ⊆ s, n < s'.card → ∃ a ∈ s', ¬ P a :=
(s.1.card_filter_le_iff P n).trans ⟨fun H s' hs' h ↦ H s'.1 (by aesop) h,
fun H s' hs' h ↦ H ⟨s', nodup_of_le hs' s.2⟩ (fun x hx ↦ subset_of_le hs' hx) h⟩
@[simp]
theorem card_map (f : α ↪ β) : (s.map f).card = s.card :=
Multiset.card_map _ _
#align finset.card_map Finset.card_map
@[simp]
theorem card_subtype (p : α → Prop) [DecidablePred p] (s : Finset α) :
(s.subtype p).card = (s.filter p).card := by simp [Finset.subtype]
#align finset.card_subtype Finset.card_subtype
theorem card_filter_le (s : Finset α) (p : α → Prop) [DecidablePred p] :
(s.filter p).card ≤ s.card :=
card_le_card <| filter_subset _ _
#align finset.card_filter_le Finset.card_filter_le
theorem eq_of_subset_of_card_le {s t : Finset α} (h : s ⊆ t) (h₂ : t.card ≤ s.card) : s = t :=
eq_of_veq <| Multiset.eq_of_le_of_card_le (val_le_iff.mpr h) h₂
#align finset.eq_of_subset_of_card_le Finset.eq_of_subset_of_card_le
theorem eq_of_superset_of_card_ge (hst : s ⊆ t) (hts : t.card ≤ s.card) : t = s :=
(eq_of_subset_of_card_le hst hts).symm
#align finset.eq_of_superset_of_card_ge Finset.eq_of_superset_of_card_ge
theorem subset_iff_eq_of_card_le (h : t.card ≤ s.card) : s ⊆ t ↔ s = t :=
⟨fun hst => eq_of_subset_of_card_le hst h, Eq.subset'⟩
#align finset.subset_iff_eq_of_card_le Finset.subset_iff_eq_of_card_le
theorem map_eq_of_subset {f : α ↪ α} (hs : s.map f ⊆ s) : s.map f = s :=
eq_of_subset_of_card_le hs (card_map _).ge
#align finset.map_eq_of_subset Finset.map_eq_of_subset
theorem filter_card_eq {p : α → Prop} [DecidablePred p] (h : (s.filter p).card = s.card) (x : α)
(hx : x ∈ s) : p x := by
rw [← eq_of_subset_of_card_le (s.filter_subset p) h.ge, mem_filter] at hx
exact hx.2
#align finset.filter_card_eq Finset.filter_card_eq
nonrec lemma card_lt_card (h : s ⊂ t) : s.card < t.card := card_lt_card <| val_lt_iff.2 h
#align finset.card_lt_card Finset.card_lt_card
lemma card_strictMono : StrictMono (card : Finset α → ℕ) := fun _ _ ↦ card_lt_card
theorem card_eq_of_bijective (f : ∀ i, i < n → α) (hf : ∀ a ∈ s, ∃ i, ∃ h : i < n, f i h = a)
(hf' : ∀ i (h : i < n), f i h ∈ s)
(f_inj : ∀ i j (hi : i < n) (hj : j < n), f i hi = f j hj → i = j) : s.card = n := by
classical
have : s = (range n).attach.image fun i => f i.1 (mem_range.1 i.2) := by
ext a
suffices _ : a ∈ s ↔ ∃ (i : _) (hi : i ∈ range n), f i (mem_range.1 hi) = a by
simpa only [mem_image, mem_attach, true_and_iff, Subtype.exists]
constructor
· intro ha; obtain ⟨i, hi, rfl⟩ := hf a ha; use i, mem_range.2 hi
· rintro ⟨i, hi, rfl⟩; apply hf'
calc
s.card = ((range n).attach.image fun i => f i.1 (mem_range.1 i.2)).card := by rw [this]
_ = (range n).attach.card := ?_
_ = (range n).card := card_attach
_ = n := card_range n
apply card_image_of_injective
intro ⟨i, hi⟩ ⟨j, hj⟩ eq
exact Subtype.eq <| f_inj i j (mem_range.1 hi) (mem_range.1 hj) eq
#align finset.card_eq_of_bijective Finset.card_eq_of_bijective
theorem card_le_card_of_inj_on {t : Finset β} (f : α → β) (hf : ∀ a ∈ s, f a ∈ t)
(f_inj : ∀ a₁ ∈ s, ∀ a₂ ∈ s, f a₁ = f a₂ → a₁ = a₂) : s.card ≤ t.card := by
classical
calc
s.card = (s.image f).card := (card_image_of_injOn f_inj).symm
_ ≤ t.card := card_le_card <| image_subset_iff.2 hf
#align finset.card_le_card_of_inj_on Finset.card_le_card_of_inj_on
theorem exists_ne_map_eq_of_card_lt_of_maps_to {t : Finset β} (hc : t.card < s.card) {f : α → β}
(hf : ∀ a ∈ s, f a ∈ t) : ∃ x ∈ s, ∃ y ∈ s, x ≠ y ∧ f x = f y := by
classical
by_contra! hz
refine hc.not_le (card_le_card_of_inj_on f hf ?_)
intro x hx y hy
contrapose
exact hz x hx y hy
#align finset.exists_ne_map_eq_of_card_lt_of_maps_to Finset.exists_ne_map_eq_of_card_lt_of_maps_to
theorem le_card_of_inj_on_range (f : ℕ → α) (hf : ∀ i < n, f i ∈ s)
(f_inj : ∀ i < n, ∀ j < n, f i = f j → i = j) : n ≤ s.card :=
calc
n = card (range n) := (card_range n).symm
_ ≤ s.card := card_le_card_of_inj_on f (by simpa only [mem_range]) (by simpa only [mem_range])
#align finset.le_card_of_inj_on_range Finset.le_card_of_inj_on_range
theorem surj_on_of_inj_on_of_card_le {t : Finset β} (f : ∀ a ∈ s, β) (hf : ∀ a ha, f a ha ∈ t)
(hinj : ∀ a₁ a₂ ha₁ ha₂, f a₁ ha₁ = f a₂ ha₂ → a₁ = a₂) (hst : t.card ≤ s.card) :
∀ b ∈ t, ∃ a ha, b = f a ha := by
classical
intro b hb
have h : (s.attach.image fun a : { a // a ∈ s } => f a a.prop).card = s.card := by
rw [← @card_attach _ s]
apply card_image_of_injective
intro ⟨_, _⟩ ⟨_, _⟩ h
exact Subtype.eq <| hinj _ _ _ _ h
have h' : image (fun a : { a // a ∈ s } => f a a.prop) s.attach = t := by
apply eq_of_subset_of_card_le
· intro b h
obtain ⟨_, _, rfl⟩ := mem_image.1 h
apply hf
· simp [hst, h]
rw [← h'] at hb
obtain ⟨a, _, rfl⟩ := mem_image.1 hb
use a, a.2
#align finset.surj_on_of_inj_on_of_card_le Finset.surj_on_of_inj_on_of_card_le
theorem inj_on_of_surj_on_of_card_le {t : Finset β} (f : ∀ a ∈ s, β) (hf : ∀ a ha, f a ha ∈ t)
(hsurj : ∀ b ∈ t, ∃ a ha, f a ha = b) (hst : s.card ≤ t.card) ⦃a₁⦄ (ha₁ : a₁ ∈ s) ⦃a₂⦄
(ha₂ : a₂ ∈ s) (ha₁a₂ : f a₁ ha₁ = f a₂ ha₂) : a₁ = a₂ :=
haveI : Inhabited { x // x ∈ s } := ⟨⟨a₁, ha₁⟩⟩
let f' : { x // x ∈ s } → { x // x ∈ t } := fun x => ⟨f x.1 x.2, hf x.1 x.2⟩
let g : { x // x ∈ t } → { x // x ∈ s } :=
@surjInv _ _ f' fun x =>
let ⟨y, hy₁, hy₂⟩ := hsurj x.1 x.2
⟨⟨y, hy₁⟩, Subtype.eq hy₂⟩
have hg : Injective g := injective_surjInv _
have hsg : Surjective g := fun x =>
let ⟨y, hy⟩ :=
surj_on_of_inj_on_of_card_le (fun (x : { x // x ∈ t }) (_ : x ∈ t.attach) => g x)
(fun x _ => show g x ∈ s.attach from mem_attach _ _) (fun x y _ _ hxy => hg hxy) (by simpa)
x (mem_attach _ _)
⟨y, hy.snd.symm⟩
have hif : Injective f' :=
(leftInverse_of_surjective_of_rightInverse hsg (rightInverse_surjInv _)).injective
Subtype.ext_iff_val.1 (@hif ⟨a₁, ha₁⟩ ⟨a₂, ha₂⟩ (Subtype.eq ha₁a₂))
#align finset.inj_on_of_surj_on_of_card_le Finset.inj_on_of_surj_on_of_card_le
@[simp]
theorem card_disjUnion (s t : Finset α) (h) : (s.disjUnion t h).card = s.card + t.card :=
Multiset.card_add _ _
#align finset.card_disj_union Finset.card_disjUnion
section Lattice
variable [DecidableEq α]
theorem card_union_add_card_inter (s t : Finset α) :
(s ∪ t).card + (s ∩ t).card = s.card + t.card :=
Finset.induction_on t (by simp) fun a r har h => by by_cases a ∈ s <;>
simp [*, ← add_assoc, add_right_comm _ 1]
#align finset.card_union_add_card_inter Finset.card_union_add_card_inter
theorem card_inter_add_card_union (s t : Finset α) :
(s ∩ t).card + (s ∪ t).card = s.card + t.card := by rw [add_comm, card_union_add_card_inter]
#align finset.card_inter_add_card_union Finset.card_inter_add_card_union
lemma card_union (s t : Finset α) : (s ∪ t).card = s.card + t.card - (s ∩ t).card := by
rw [← card_union_add_card_inter, Nat.add_sub_cancel]
lemma card_inter (s t : Finset α) : (s ∩ t).card = s.card + t.card - (s ∪ t).card := by
rw [← card_inter_add_card_union, Nat.add_sub_cancel]
theorem card_union_le (s t : Finset α) : (s ∪ t).card ≤ s.card + t.card :=
card_union_add_card_inter s t ▸ Nat.le_add_right _ _
#align finset.card_union_le Finset.card_union_le
lemma card_union_eq_card_add_card : (s ∪ t).card = s.card + t.card ↔ Disjoint s t := by
rw [← card_union_add_card_inter]; simp [disjoint_iff_inter_eq_empty]
@[simp] alias ⟨_, card_union_of_disjoint⟩ := card_union_eq_card_add_card
#align finset.card_union_eq Finset.card_union_of_disjoint
#align finset.card_disjoint_union Finset.card_union_of_disjoint
@[deprecated (since := "2024-02-09")] alias card_union_eq := card_union_of_disjoint
@[deprecated (since := "2024-02-09")] alias card_disjoint_union := card_union_of_disjoint
lemma cast_card_inter [AddGroupWithOne R] :
((s ∩ t).card : R) = s.card + t.card - (s ∪ t).card := by
rw [eq_sub_iff_add_eq, ← cast_add, card_inter_add_card_union, cast_add]
lemma cast_card_union [AddGroupWithOne R] :
((s ∪ t).card : R) = s.card + t.card - (s ∩ t).card := by
rw [eq_sub_iff_add_eq, ← cast_add, card_union_add_card_inter, cast_add]
| Mathlib/Data/Finset/Card.lean | 565 | 567 | theorem card_sdiff (h : s ⊆ t) : card (t \ s) = t.card - s.card := by |
suffices card (t \ s) = card (t \ s ∪ s) - s.card by rwa [sdiff_union_of_subset h] at this
rw [card_union_of_disjoint sdiff_disjoint, Nat.add_sub_cancel_right]
|
import Mathlib.Order.PropInstances
#align_import order.heyting.basic from "leanprover-community/mathlib"@"9ac7c0c8c4d7a535ec3e5b34b8859aab9233b2f4"
open Function OrderDual
universe u
variable {ι α β : Type*}
section
variable (α β)
instance Prod.instHImp [HImp α] [HImp β] : HImp (α × β) :=
⟨fun a b => (a.1 ⇨ b.1, a.2 ⇨ b.2)⟩
instance Prod.instHNot [HNot α] [HNot β] : HNot (α × β) :=
⟨fun a => (￢a.1, ￢a.2)⟩
instance Prod.instSDiff [SDiff α] [SDiff β] : SDiff (α × β) :=
⟨fun a b => (a.1 \ b.1, a.2 \ b.2)⟩
instance Prod.instHasCompl [HasCompl α] [HasCompl β] : HasCompl (α × β) :=
⟨fun a => (a.1ᶜ, a.2ᶜ)⟩
end
@[simp]
theorem fst_himp [HImp α] [HImp β] (a b : α × β) : (a ⇨ b).1 = a.1 ⇨ b.1 :=
rfl
#align fst_himp fst_himp
@[simp]
theorem snd_himp [HImp α] [HImp β] (a b : α × β) : (a ⇨ b).2 = a.2 ⇨ b.2 :=
rfl
#align snd_himp snd_himp
@[simp]
theorem fst_hnot [HNot α] [HNot β] (a : α × β) : (￢a).1 = ￢a.1 :=
rfl
#align fst_hnot fst_hnot
@[simp]
theorem snd_hnot [HNot α] [HNot β] (a : α × β) : (￢a).2 = ￢a.2 :=
rfl
#align snd_hnot snd_hnot
@[simp]
theorem fst_sdiff [SDiff α] [SDiff β] (a b : α × β) : (a \ b).1 = a.1 \ b.1 :=
rfl
#align fst_sdiff fst_sdiff
@[simp]
theorem snd_sdiff [SDiff α] [SDiff β] (a b : α × β) : (a \ b).2 = a.2 \ b.2 :=
rfl
#align snd_sdiff snd_sdiff
@[simp]
theorem fst_compl [HasCompl α] [HasCompl β] (a : α × β) : aᶜ.1 = a.1ᶜ :=
rfl
#align fst_compl fst_compl
@[simp]
theorem snd_compl [HasCompl α] [HasCompl β] (a : α × β) : aᶜ.2 = a.2ᶜ :=
rfl
#align snd_compl snd_compl
class GeneralizedHeytingAlgebra (α : Type*) extends Lattice α, OrderTop α, HImp α where
le_himp_iff (a b c : α) : a ≤ b ⇨ c ↔ a ⊓ b ≤ c
#align generalized_heyting_algebra GeneralizedHeytingAlgebra
#align generalized_heyting_algebra.to_order_top GeneralizedHeytingAlgebra.toOrderTop
class GeneralizedCoheytingAlgebra (α : Type*) extends Lattice α, OrderBot α, SDiff α where
sdiff_le_iff (a b c : α) : a \ b ≤ c ↔ a ≤ b ⊔ c
#align generalized_coheyting_algebra GeneralizedCoheytingAlgebra
#align generalized_coheyting_algebra.to_order_bot GeneralizedCoheytingAlgebra.toOrderBot
class HeytingAlgebra (α : Type*) extends GeneralizedHeytingAlgebra α, OrderBot α, HasCompl α where
himp_bot (a : α) : a ⇨ ⊥ = aᶜ
#align heyting_algebra HeytingAlgebra
class CoheytingAlgebra (α : Type*) extends GeneralizedCoheytingAlgebra α, OrderTop α, HNot α where
top_sdiff (a : α) : ⊤ \ a = ￢a
#align coheyting_algebra CoheytingAlgebra
class BiheytingAlgebra (α : Type*) extends HeytingAlgebra α, SDiff α, HNot α where
sdiff_le_iff (a b c : α) : a \ b ≤ c ↔ a ≤ b ⊔ c
top_sdiff (a : α) : ⊤ \ a = ￢a
#align biheyting_algebra BiheytingAlgebra
-- See note [lower instance priority]
attribute [instance 100] GeneralizedHeytingAlgebra.toOrderTop
attribute [instance 100] GeneralizedCoheytingAlgebra.toOrderBot
-- See note [lower instance priority]
instance (priority := 100) HeytingAlgebra.toBoundedOrder [HeytingAlgebra α] : BoundedOrder α :=
{ bot_le := ‹HeytingAlgebra α›.bot_le }
--#align heyting_algebra.to_bounded_order HeytingAlgebra.toBoundedOrder
-- See note [lower instance priority]
instance (priority := 100) CoheytingAlgebra.toBoundedOrder [CoheytingAlgebra α] : BoundedOrder α :=
{ ‹CoheytingAlgebra α› with }
#align coheyting_algebra.to_bounded_order CoheytingAlgebra.toBoundedOrder
-- See note [lower instance priority]
instance (priority := 100) BiheytingAlgebra.toCoheytingAlgebra [BiheytingAlgebra α] :
CoheytingAlgebra α :=
{ ‹BiheytingAlgebra α› with }
#align biheyting_algebra.to_coheyting_algebra BiheytingAlgebra.toCoheytingAlgebra
-- See note [reducible non-instances]
abbrev HeytingAlgebra.ofHImp [DistribLattice α] [BoundedOrder α] (himp : α → α → α)
(le_himp_iff : ∀ a b c, a ≤ himp b c ↔ a ⊓ b ≤ c) : HeytingAlgebra α :=
{ ‹DistribLattice α›, ‹BoundedOrder α› with
himp,
compl := fun a => himp a ⊥,
le_himp_iff,
himp_bot := fun a => rfl }
#align heyting_algebra.of_himp HeytingAlgebra.ofHImp
-- See note [reducible non-instances]
abbrev HeytingAlgebra.ofCompl [DistribLattice α] [BoundedOrder α] (compl : α → α)
(le_himp_iff : ∀ a b c, a ≤ compl b ⊔ c ↔ a ⊓ b ≤ c) : HeytingAlgebra α where
himp := (compl · ⊔ ·)
compl := compl
le_himp_iff := le_himp_iff
himp_bot _ := sup_bot_eq _
#align heyting_algebra.of_compl HeytingAlgebra.ofCompl
-- See note [reducible non-instances]
abbrev CoheytingAlgebra.ofSDiff [DistribLattice α] [BoundedOrder α] (sdiff : α → α → α)
(sdiff_le_iff : ∀ a b c, sdiff a b ≤ c ↔ a ≤ b ⊔ c) : CoheytingAlgebra α :=
{ ‹DistribLattice α›, ‹BoundedOrder α› with
sdiff,
hnot := fun a => sdiff ⊤ a,
sdiff_le_iff,
top_sdiff := fun a => rfl }
#align coheyting_algebra.of_sdiff CoheytingAlgebra.ofSDiff
-- See note [reducible non-instances]
abbrev CoheytingAlgebra.ofHNot [DistribLattice α] [BoundedOrder α] (hnot : α → α)
(sdiff_le_iff : ∀ a b c, a ⊓ hnot b ≤ c ↔ a ≤ b ⊔ c) : CoheytingAlgebra α where
sdiff a b := a ⊓ hnot b
hnot := hnot
sdiff_le_iff := sdiff_le_iff
top_sdiff _ := top_inf_eq _
#align coheyting_algebra.of_hnot CoheytingAlgebra.ofHNot
section GeneralizedCoheytingAlgebra
variable [GeneralizedCoheytingAlgebra α] {a b c d : α}
@[simp]
theorem sdiff_le_iff : a \ b ≤ c ↔ a ≤ b ⊔ c :=
GeneralizedCoheytingAlgebra.sdiff_le_iff _ _ _
#align sdiff_le_iff sdiff_le_iff
theorem sdiff_le_iff' : a \ b ≤ c ↔ a ≤ c ⊔ b := by rw [sdiff_le_iff, sup_comm]
#align sdiff_le_iff' sdiff_le_iff'
theorem sdiff_le_comm : a \ b ≤ c ↔ a \ c ≤ b := by rw [sdiff_le_iff, sdiff_le_iff']
#align sdiff_le_comm sdiff_le_comm
theorem sdiff_le : a \ b ≤ a :=
sdiff_le_iff.2 le_sup_right
#align sdiff_le sdiff_le
theorem Disjoint.disjoint_sdiff_left (h : Disjoint a b) : Disjoint (a \ c) b :=
h.mono_left sdiff_le
#align disjoint.disjoint_sdiff_left Disjoint.disjoint_sdiff_left
theorem Disjoint.disjoint_sdiff_right (h : Disjoint a b) : Disjoint a (b \ c) :=
h.mono_right sdiff_le
#align disjoint.disjoint_sdiff_right Disjoint.disjoint_sdiff_right
theorem sdiff_le_iff_left : a \ b ≤ b ↔ a ≤ b := by rw [sdiff_le_iff, sup_idem]
#align sdiff_le_iff_left sdiff_le_iff_left
@[simp]
theorem sdiff_self : a \ a = ⊥ :=
le_bot_iff.1 <| sdiff_le_iff.2 le_sup_left
#align sdiff_self sdiff_self
theorem le_sup_sdiff : a ≤ b ⊔ a \ b :=
sdiff_le_iff.1 le_rfl
#align le_sup_sdiff le_sup_sdiff
theorem le_sdiff_sup : a ≤ a \ b ⊔ b := by rw [sup_comm, ← sdiff_le_iff]
#align le_sdiff_sup le_sdiff_sup
theorem sup_sdiff_left : a ⊔ a \ b = a :=
sup_of_le_left sdiff_le
#align sup_sdiff_left sup_sdiff_left
theorem sup_sdiff_right : a \ b ⊔ a = a :=
sup_of_le_right sdiff_le
#align sup_sdiff_right sup_sdiff_right
theorem inf_sdiff_left : a \ b ⊓ a = a \ b :=
inf_of_le_left sdiff_le
#align inf_sdiff_left inf_sdiff_left
theorem inf_sdiff_right : a ⊓ a \ b = a \ b :=
inf_of_le_right sdiff_le
#align inf_sdiff_right inf_sdiff_right
@[simp]
theorem sup_sdiff_self (a b : α) : a ⊔ b \ a = a ⊔ b :=
le_antisymm (sup_le_sup_left sdiff_le _) (sup_le le_sup_left le_sup_sdiff)
#align sup_sdiff_self sup_sdiff_self
@[simp]
theorem sdiff_sup_self (a b : α) : b \ a ⊔ a = b ⊔ a := by rw [sup_comm, sup_sdiff_self, sup_comm]
#align sdiff_sup_self sdiff_sup_self
alias sup_sdiff_self_left := sdiff_sup_self
#align sup_sdiff_self_left sup_sdiff_self_left
alias sup_sdiff_self_right := sup_sdiff_self
#align sup_sdiff_self_right sup_sdiff_self_right
theorem sup_sdiff_eq_sup (h : c ≤ a) : a ⊔ b \ c = a ⊔ b :=
sup_congr_left (sdiff_le.trans le_sup_right) <| le_sup_sdiff.trans <| sup_le_sup_right h _
#align sup_sdiff_eq_sup sup_sdiff_eq_sup
-- cf. `Set.union_diff_cancel'`
theorem sup_sdiff_cancel' (hab : a ≤ b) (hbc : b ≤ c) : b ⊔ c \ a = c := by
rw [sup_sdiff_eq_sup hab, sup_of_le_right hbc]
#align sup_sdiff_cancel' sup_sdiff_cancel'
theorem sup_sdiff_cancel_right (h : a ≤ b) : a ⊔ b \ a = b :=
sup_sdiff_cancel' le_rfl h
#align sup_sdiff_cancel_right sup_sdiff_cancel_right
theorem sdiff_sup_cancel (h : b ≤ a) : a \ b ⊔ b = a := by rw [sup_comm, sup_sdiff_cancel_right h]
#align sdiff_sup_cancel sdiff_sup_cancel
theorem sup_le_of_le_sdiff_left (h : b ≤ c \ a) (hac : a ≤ c) : a ⊔ b ≤ c :=
sup_le hac <| h.trans sdiff_le
#align sup_le_of_le_sdiff_left sup_le_of_le_sdiff_left
theorem sup_le_of_le_sdiff_right (h : a ≤ c \ b) (hbc : b ≤ c) : a ⊔ b ≤ c :=
sup_le (h.trans sdiff_le) hbc
#align sup_le_of_le_sdiff_right sup_le_of_le_sdiff_right
@[simp]
theorem sdiff_eq_bot_iff : a \ b = ⊥ ↔ a ≤ b := by rw [← le_bot_iff, sdiff_le_iff, sup_bot_eq]
#align sdiff_eq_bot_iff sdiff_eq_bot_iff
@[simp]
theorem sdiff_bot : a \ ⊥ = a :=
eq_of_forall_ge_iff fun b => by rw [sdiff_le_iff, bot_sup_eq]
#align sdiff_bot sdiff_bot
@[simp]
theorem bot_sdiff : ⊥ \ a = ⊥ :=
sdiff_eq_bot_iff.2 bot_le
#align bot_sdiff bot_sdiff
theorem sdiff_sdiff_sdiff_le_sdiff : (a \ b) \ (a \ c) ≤ c \ b := by
rw [sdiff_le_iff, sdiff_le_iff, sup_left_comm, sup_sdiff_self, sup_left_comm, sdiff_sup_self,
sup_left_comm]
exact le_sup_left
#align sdiff_sdiff_sdiff_le_sdiff sdiff_sdiff_sdiff_le_sdiff
@[simp]
theorem le_sup_sdiff_sup_sdiff : a ≤ b ⊔ (a \ c ⊔ c \ b) := by
simpa using @sdiff_sdiff_sdiff_le_sdiff
theorem sdiff_sdiff (a b c : α) : (a \ b) \ c = a \ (b ⊔ c) :=
eq_of_forall_ge_iff fun d => by simp_rw [sdiff_le_iff, sup_assoc]
#align sdiff_sdiff sdiff_sdiff
theorem sdiff_sdiff_left : (a \ b) \ c = a \ (b ⊔ c) :=
sdiff_sdiff _ _ _
#align sdiff_sdiff_left sdiff_sdiff_left
theorem sdiff_right_comm (a b c : α) : (a \ b) \ c = (a \ c) \ b := by
simp_rw [sdiff_sdiff, sup_comm]
#align sdiff_right_comm sdiff_right_comm
theorem sdiff_sdiff_comm : (a \ b) \ c = (a \ c) \ b :=
sdiff_right_comm _ _ _
#align sdiff_sdiff_comm sdiff_sdiff_comm
@[simp]
theorem sdiff_idem : (a \ b) \ b = a \ b := by rw [sdiff_sdiff_left, sup_idem]
#align sdiff_idem sdiff_idem
@[simp]
theorem sdiff_sdiff_self : (a \ b) \ a = ⊥ := by rw [sdiff_sdiff_comm, sdiff_self, bot_sdiff]
#align sdiff_sdiff_self sdiff_sdiff_self
theorem sup_sdiff_distrib (a b c : α) : (a ⊔ b) \ c = a \ c ⊔ b \ c :=
eq_of_forall_ge_iff fun d => by simp_rw [sdiff_le_iff, sup_le_iff, sdiff_le_iff]
#align sup_sdiff_distrib sup_sdiff_distrib
theorem sdiff_inf_distrib (a b c : α) : a \ (b ⊓ c) = a \ b ⊔ a \ c :=
eq_of_forall_ge_iff fun d => by
rw [sup_le_iff, sdiff_le_comm, le_inf_iff]
simp_rw [sdiff_le_comm]
#align sdiff_inf_distrib sdiff_inf_distrib
theorem sup_sdiff : (a ⊔ b) \ c = a \ c ⊔ b \ c :=
sup_sdiff_distrib _ _ _
#align sup_sdiff sup_sdiff
@[simp]
theorem sup_sdiff_right_self : (a ⊔ b) \ b = a \ b := by rw [sup_sdiff, sdiff_self, sup_bot_eq]
#align sup_sdiff_right_self sup_sdiff_right_self
@[simp]
theorem sup_sdiff_left_self : (a ⊔ b) \ a = b \ a := by rw [sup_comm, sup_sdiff_right_self]
#align sup_sdiff_left_self sup_sdiff_left_self
@[gcongr]
theorem sdiff_le_sdiff_right (h : a ≤ b) : a \ c ≤ b \ c :=
sdiff_le_iff.2 <| h.trans <| le_sup_sdiff
#align sdiff_le_sdiff_right sdiff_le_sdiff_right
@[gcongr]
theorem sdiff_le_sdiff_left (h : a ≤ b) : c \ b ≤ c \ a :=
sdiff_le_iff.2 <| le_sup_sdiff.trans <| sup_le_sup_right h _
#align sdiff_le_sdiff_left sdiff_le_sdiff_left
@[gcongr]
theorem sdiff_le_sdiff (hab : a ≤ b) (hcd : c ≤ d) : a \ d ≤ b \ c :=
(sdiff_le_sdiff_right hab).trans <| sdiff_le_sdiff_left hcd
#align sdiff_le_sdiff sdiff_le_sdiff
-- cf. `IsCompl.inf_sup`
theorem sdiff_inf : a \ (b ⊓ c) = a \ b ⊔ a \ c :=
sdiff_inf_distrib _ _ _
#align sdiff_inf sdiff_inf
@[simp]
theorem sdiff_inf_self_left (a b : α) : a \ (a ⊓ b) = a \ b := by
rw [sdiff_inf, sdiff_self, bot_sup_eq]
#align sdiff_inf_self_left sdiff_inf_self_left
@[simp]
| Mathlib/Order/Heyting/Basic.lean | 628 | 629 | theorem sdiff_inf_self_right (a b : α) : b \ (a ⊓ b) = b \ a := by |
rw [sdiff_inf, sdiff_self, sup_bot_eq]
|
import Mathlib.Algebra.BigOperators.GroupWithZero.Finset
import Mathlib.Data.Finite.Card
import Mathlib.GroupTheory.Finiteness
import Mathlib.GroupTheory.GroupAction.Quotient
#align_import group_theory.index from "leanprover-community/mathlib"@"dc6c365e751e34d100e80fe6e314c3c3e0fd2988"
namespace Subgroup
open Cardinal
variable {G : Type*} [Group G] (H K L : Subgroup G)
@[to_additive "The index of a subgroup as a natural number,
and returns 0 if the index is infinite."]
noncomputable def index : ℕ :=
Nat.card (G ⧸ H)
#align subgroup.index Subgroup.index
#align add_subgroup.index AddSubgroup.index
@[to_additive "The relative index of a subgroup as a natural number,
and returns 0 if the relative index is infinite."]
noncomputable def relindex : ℕ :=
(H.subgroupOf K).index
#align subgroup.relindex Subgroup.relindex
#align add_subgroup.relindex AddSubgroup.relindex
@[to_additive]
theorem index_comap_of_surjective {G' : Type*} [Group G'] {f : G' →* G}
(hf : Function.Surjective f) : (H.comap f).index = H.index := by
letI := QuotientGroup.leftRel H
letI := QuotientGroup.leftRel (H.comap f)
have key : ∀ x y : G', Setoid.r x y ↔ Setoid.r (f x) (f y) := by
simp only [QuotientGroup.leftRel_apply]
exact fun x y => iff_of_eq (congr_arg (· ∈ H) (by rw [f.map_mul, f.map_inv]))
refine Cardinal.toNat_congr (Equiv.ofBijective (Quotient.map' f fun x y => (key x y).mp) ⟨?_, ?_⟩)
· simp_rw [← Quotient.eq''] at key
refine Quotient.ind' fun x => ?_
refine Quotient.ind' fun y => ?_
exact (key x y).mpr
· refine Quotient.ind' fun x => ?_
obtain ⟨y, hy⟩ := hf x
exact ⟨y, (Quotient.map'_mk'' f _ y).trans (congr_arg Quotient.mk'' hy)⟩
#align subgroup.index_comap_of_surjective Subgroup.index_comap_of_surjective
#align add_subgroup.index_comap_of_surjective AddSubgroup.index_comap_of_surjective
@[to_additive]
theorem index_comap {G' : Type*} [Group G'] (f : G' →* G) :
(H.comap f).index = H.relindex f.range :=
Eq.trans (congr_arg index (by rfl))
((H.subgroupOf f.range).index_comap_of_surjective f.rangeRestrict_surjective)
#align subgroup.index_comap Subgroup.index_comap
#align add_subgroup.index_comap AddSubgroup.index_comap
@[to_additive]
theorem relindex_comap {G' : Type*} [Group G'] (f : G' →* G) (K : Subgroup G') :
relindex (comap f H) K = relindex H (map f K) := by
rw [relindex, subgroupOf, comap_comap, index_comap, ← f.map_range, K.subtype_range]
#align subgroup.relindex_comap Subgroup.relindex_comap
#align add_subgroup.relindex_comap AddSubgroup.relindex_comap
variable {H K L}
@[to_additive relindex_mul_index]
theorem relindex_mul_index (h : H ≤ K) : H.relindex K * K.index = H.index :=
((mul_comm _ _).trans (Cardinal.toNat_mul _ _).symm).trans
(congr_arg Cardinal.toNat (Equiv.cardinal_eq (quotientEquivProdOfLE h))).symm
#align subgroup.relindex_mul_index Subgroup.relindex_mul_index
#align add_subgroup.relindex_mul_index AddSubgroup.relindex_mul_index
@[to_additive]
theorem index_dvd_of_le (h : H ≤ K) : K.index ∣ H.index :=
dvd_of_mul_left_eq (H.relindex K) (relindex_mul_index h)
#align subgroup.index_dvd_of_le Subgroup.index_dvd_of_le
#align add_subgroup.index_dvd_of_le AddSubgroup.index_dvd_of_le
@[to_additive]
theorem relindex_dvd_index_of_le (h : H ≤ K) : H.relindex K ∣ H.index :=
dvd_of_mul_right_eq K.index (relindex_mul_index h)
#align subgroup.relindex_dvd_index_of_le Subgroup.relindex_dvd_index_of_le
#align add_subgroup.relindex_dvd_index_of_le AddSubgroup.relindex_dvd_index_of_le
@[to_additive]
theorem relindex_subgroupOf (hKL : K ≤ L) :
(H.subgroupOf L).relindex (K.subgroupOf L) = H.relindex K :=
((index_comap (H.subgroupOf L) (inclusion hKL)).trans (congr_arg _ (inclusion_range hKL))).symm
#align subgroup.relindex_subgroup_of Subgroup.relindex_subgroupOf
#align add_subgroup.relindex_add_subgroup_of AddSubgroup.relindex_addSubgroupOf
variable (H K L)
@[to_additive relindex_mul_relindex]
theorem relindex_mul_relindex (hHK : H ≤ K) (hKL : K ≤ L) :
H.relindex K * K.relindex L = H.relindex L := by
rw [← relindex_subgroupOf hKL]
exact relindex_mul_index fun x hx => hHK hx
#align subgroup.relindex_mul_relindex Subgroup.relindex_mul_relindex
#align add_subgroup.relindex_mul_relindex AddSubgroup.relindex_mul_relindex
@[to_additive]
theorem inf_relindex_right : (H ⊓ K).relindex K = H.relindex K := by
rw [relindex, relindex, inf_subgroupOf_right]
#align subgroup.inf_relindex_right Subgroup.inf_relindex_right
#align add_subgroup.inf_relindex_right AddSubgroup.inf_relindex_right
@[to_additive]
theorem inf_relindex_left : (H ⊓ K).relindex H = K.relindex H := by
rw [inf_comm, inf_relindex_right]
#align subgroup.inf_relindex_left Subgroup.inf_relindex_left
#align add_subgroup.inf_relindex_left AddSubgroup.inf_relindex_left
@[to_additive relindex_inf_mul_relindex]
theorem relindex_inf_mul_relindex : H.relindex (K ⊓ L) * K.relindex L = (H ⊓ K).relindex L := by
rw [← inf_relindex_right H (K ⊓ L), ← inf_relindex_right K L, ← inf_relindex_right (H ⊓ K) L,
inf_assoc, relindex_mul_relindex (H ⊓ (K ⊓ L)) (K ⊓ L) L inf_le_right inf_le_right]
#align subgroup.relindex_inf_mul_relindex Subgroup.relindex_inf_mul_relindex
#align add_subgroup.relindex_inf_mul_relindex AddSubgroup.relindex_inf_mul_relindex
@[to_additive (attr := simp)]
theorem relindex_sup_right [K.Normal] : K.relindex (H ⊔ K) = K.relindex H :=
Nat.card_congr (QuotientGroup.quotientInfEquivProdNormalQuotient H K).toEquiv.symm
#align subgroup.relindex_sup_right Subgroup.relindex_sup_right
#align add_subgroup.relindex_sup_right AddSubgroup.relindex_sup_right
@[to_additive (attr := simp)]
| Mathlib/GroupTheory/Index.lean | 159 | 160 | theorem relindex_sup_left [K.Normal] : K.relindex (K ⊔ H) = K.relindex H := by |
rw [sup_comm, relindex_sup_right]
|
import Mathlib.FieldTheory.Tower
import Mathlib.RingTheory.Algebraic
import Mathlib.FieldTheory.Minpoly.Basic
#align_import field_theory.intermediate_field from "leanprover-community/mathlib"@"c596622fccd6e0321979d94931c964054dea2d26"
open FiniteDimensional Polynomial
open Polynomial
variable (K L L' : Type*) [Field K] [Field L] [Field L'] [Algebra K L] [Algebra K L']
structure IntermediateField extends Subalgebra K L where
inv_mem' : ∀ x ∈ carrier, x⁻¹ ∈ carrier
#align intermediate_field IntermediateField
add_decl_doc IntermediateField.toSubalgebra
variable {K L L'}
variable (S : IntermediateField K L)
namespace IntermediateField
instance : SetLike (IntermediateField K L) L :=
⟨fun S => S.toSubalgebra.carrier, by
rintro ⟨⟨⟩⟩ ⟨⟨⟩⟩
simp ⟩
protected theorem neg_mem {x : L} (hx : x ∈ S) : -x ∈ S := by
show -x ∈S.toSubalgebra; simpa
#align intermediate_field.neg_mem IntermediateField.neg_mem
def toSubfield : Subfield L :=
{ S.toSubalgebra with
neg_mem' := S.neg_mem,
inv_mem' := S.inv_mem' }
#align intermediate_field.to_subfield IntermediateField.toSubfield
instance : SubfieldClass (IntermediateField K L) L where
add_mem {s} := s.add_mem'
zero_mem {s} := s.zero_mem'
neg_mem {s} := s.neg_mem
mul_mem {s} := s.mul_mem'
one_mem {s} := s.one_mem'
inv_mem {s} := s.inv_mem' _
--@[simp] Porting note (#10618): simp can prove it
theorem mem_carrier {s : IntermediateField K L} {x : L} : x ∈ s.carrier ↔ x ∈ s :=
Iff.rfl
#align intermediate_field.mem_carrier IntermediateField.mem_carrier
@[ext]
theorem ext {S T : IntermediateField K L} (h : ∀ x, x ∈ S ↔ x ∈ T) : S = T :=
SetLike.ext h
#align intermediate_field.ext IntermediateField.ext
@[simp]
theorem coe_toSubalgebra : (S.toSubalgebra : Set L) = S :=
rfl
#align intermediate_field.coe_to_subalgebra IntermediateField.coe_toSubalgebra
@[simp]
theorem coe_toSubfield : (S.toSubfield : Set L) = S :=
rfl
#align intermediate_field.coe_to_subfield IntermediateField.coe_toSubfield
@[simp]
theorem mem_mk (s : Subsemiring L) (hK : ∀ x, algebraMap K L x ∈ s) (hi) (x : L) :
x ∈ IntermediateField.mk (Subalgebra.mk s hK) hi ↔ x ∈ s :=
Iff.rfl
#align intermediate_field.mem_mk IntermediateField.mem_mkₓ
@[simp]
theorem mem_toSubalgebra (s : IntermediateField K L) (x : L) : x ∈ s.toSubalgebra ↔ x ∈ s :=
Iff.rfl
#align intermediate_field.mem_to_subalgebra IntermediateField.mem_toSubalgebra
@[simp]
theorem mem_toSubfield (s : IntermediateField K L) (x : L) : x ∈ s.toSubfield ↔ x ∈ s :=
Iff.rfl
#align intermediate_field.mem_to_subfield IntermediateField.mem_toSubfield
protected def copy (S : IntermediateField K L) (s : Set L) (hs : s = ↑S) :
IntermediateField K L where
toSubalgebra := S.toSubalgebra.copy s (hs : s = S.toSubalgebra.carrier)
inv_mem' :=
have hs' : (S.toSubalgebra.copy s hs).carrier = S.toSubalgebra.carrier := hs
hs'.symm ▸ S.inv_mem'
#align intermediate_field.copy IntermediateField.copy
@[simp]
theorem coe_copy (S : IntermediateField K L) (s : Set L) (hs : s = ↑S) :
(S.copy s hs : Set L) = s :=
rfl
#align intermediate_field.coe_copy IntermediateField.coe_copy
theorem copy_eq (S : IntermediateField K L) (s : Set L) (hs : s = ↑S) : S.copy s hs = S :=
SetLike.coe_injective hs
#align intermediate_field.copy_eq IntermediateField.copy_eq
| Mathlib/FieldTheory/IntermediateField.lean | 273 | 273 | theorem natCast_mem (n : ℕ) : (n : L) ∈ S := by | simpa using intCast_mem S n
|
import Mathlib.Analysis.NormedSpace.IndicatorFunction
import Mathlib.MeasureTheory.Function.EssSup
import Mathlib.MeasureTheory.Function.AEEqFun
import Mathlib.MeasureTheory.Function.SpecialFunctions.Basic
#align_import measure_theory.function.lp_seminorm from "leanprover-community/mathlib"@"c4015acc0a223449d44061e27ddac1835a3852b9"
noncomputable section
set_option linter.uppercaseLean3 false
open TopologicalSpace MeasureTheory Filter
open scoped NNReal ENNReal Topology
variable {α E F G : Type*} {m m0 : MeasurableSpace α} {p : ℝ≥0∞} {q : ℝ} {μ ν : Measure α}
[NormedAddCommGroup E] [NormedAddCommGroup F] [NormedAddCommGroup G]
namespace MeasureTheory
section ℒp
theorem snorm'_mono_nnnorm_ae {f : α → F} {g : α → G} (hq : 0 ≤ q) (h : ∀ᵐ x ∂μ, ‖f x‖₊ ≤ ‖g x‖₊) :
snorm' f q μ ≤ snorm' g q μ := by
simp only [snorm']
gcongr ?_ ^ (1/q)
refine lintegral_mono_ae (h.mono fun x hx => ?_)
gcongr
#align measure_theory.snorm'_mono_nnnorm_ae MeasureTheory.snorm'_mono_nnnorm_ae
theorem snorm'_mono_ae {f : α → F} {g : α → G} (hq : 0 ≤ q) (h : ∀ᵐ x ∂μ, ‖f x‖ ≤ ‖g x‖) :
snorm' f q μ ≤ snorm' g q μ :=
snorm'_mono_nnnorm_ae hq h
#align measure_theory.snorm'_mono_ae MeasureTheory.snorm'_mono_ae
theorem snorm'_congr_nnnorm_ae {f g : α → F} (hfg : ∀ᵐ x ∂μ, ‖f x‖₊ = ‖g x‖₊) :
snorm' f q μ = snorm' g q μ := by
have : (fun x => (‖f x‖₊ : ℝ≥0∞) ^ q) =ᵐ[μ] fun x => (‖g x‖₊ : ℝ≥0∞) ^ q :=
hfg.mono fun x hx => by simp_rw [hx]
simp only [snorm', lintegral_congr_ae this]
#align measure_theory.snorm'_congr_nnnorm_ae MeasureTheory.snorm'_congr_nnnorm_ae
theorem snorm'_congr_norm_ae {f g : α → F} (hfg : ∀ᵐ x ∂μ, ‖f x‖ = ‖g x‖) :
snorm' f q μ = snorm' g q μ :=
snorm'_congr_nnnorm_ae <| hfg.mono fun _x hx => NNReal.eq hx
#align measure_theory.snorm'_congr_norm_ae MeasureTheory.snorm'_congr_norm_ae
theorem snorm'_congr_ae {f g : α → F} (hfg : f =ᵐ[μ] g) : snorm' f q μ = snorm' g q μ :=
snorm'_congr_nnnorm_ae (hfg.fun_comp _)
#align measure_theory.snorm'_congr_ae MeasureTheory.snorm'_congr_ae
theorem snormEssSup_congr_ae {f g : α → F} (hfg : f =ᵐ[μ] g) : snormEssSup f μ = snormEssSup g μ :=
essSup_congr_ae (hfg.fun_comp (((↑) : ℝ≥0 → ℝ≥0∞) ∘ nnnorm))
#align measure_theory.snorm_ess_sup_congr_ae MeasureTheory.snormEssSup_congr_ae
theorem snormEssSup_mono_nnnorm_ae {f g : α → F} (hfg : ∀ᵐ x ∂μ, ‖f x‖₊ ≤ ‖g x‖₊) :
snormEssSup f μ ≤ snormEssSup g μ :=
essSup_mono_ae <| hfg.mono fun _x hx => ENNReal.coe_le_coe.mpr hx
#align measure_theory.snorm_ess_sup_mono_nnnorm_ae MeasureTheory.snormEssSup_mono_nnnorm_ae
theorem snorm_mono_nnnorm_ae {f : α → F} {g : α → G} (h : ∀ᵐ x ∂μ, ‖f x‖₊ ≤ ‖g x‖₊) :
snorm f p μ ≤ snorm g p μ := by
simp only [snorm]
split_ifs
· exact le_rfl
· exact essSup_mono_ae (h.mono fun x hx => ENNReal.coe_le_coe.mpr hx)
· exact snorm'_mono_nnnorm_ae ENNReal.toReal_nonneg h
#align measure_theory.snorm_mono_nnnorm_ae MeasureTheory.snorm_mono_nnnorm_ae
theorem snorm_mono_ae {f : α → F} {g : α → G} (h : ∀ᵐ x ∂μ, ‖f x‖ ≤ ‖g x‖) :
snorm f p μ ≤ snorm g p μ :=
snorm_mono_nnnorm_ae h
#align measure_theory.snorm_mono_ae MeasureTheory.snorm_mono_ae
theorem snorm_mono_ae_real {f : α → F} {g : α → ℝ} (h : ∀ᵐ x ∂μ, ‖f x‖ ≤ g x) :
snorm f p μ ≤ snorm g p μ :=
snorm_mono_ae <| h.mono fun _x hx => hx.trans ((le_abs_self _).trans (Real.norm_eq_abs _).symm.le)
#align measure_theory.snorm_mono_ae_real MeasureTheory.snorm_mono_ae_real
theorem snorm_mono_nnnorm {f : α → F} {g : α → G} (h : ∀ x, ‖f x‖₊ ≤ ‖g x‖₊) :
snorm f p μ ≤ snorm g p μ :=
snorm_mono_nnnorm_ae (eventually_of_forall fun x => h x)
#align measure_theory.snorm_mono_nnnorm MeasureTheory.snorm_mono_nnnorm
theorem snorm_mono {f : α → F} {g : α → G} (h : ∀ x, ‖f x‖ ≤ ‖g x‖) : snorm f p μ ≤ snorm g p μ :=
snorm_mono_ae (eventually_of_forall fun x => h x)
#align measure_theory.snorm_mono MeasureTheory.snorm_mono
theorem snorm_mono_real {f : α → F} {g : α → ℝ} (h : ∀ x, ‖f x‖ ≤ g x) :
snorm f p μ ≤ snorm g p μ :=
snorm_mono_ae_real (eventually_of_forall fun x => h x)
#align measure_theory.snorm_mono_real MeasureTheory.snorm_mono_real
theorem snormEssSup_le_of_ae_nnnorm_bound {f : α → F} {C : ℝ≥0} (hfC : ∀ᵐ x ∂μ, ‖f x‖₊ ≤ C) :
snormEssSup f μ ≤ C :=
essSup_le_of_ae_le (C : ℝ≥0∞) <| hfC.mono fun _x hx => ENNReal.coe_le_coe.mpr hx
#align measure_theory.snorm_ess_sup_le_of_ae_nnnorm_bound MeasureTheory.snormEssSup_le_of_ae_nnnorm_bound
theorem snormEssSup_le_of_ae_bound {f : α → F} {C : ℝ} (hfC : ∀ᵐ x ∂μ, ‖f x‖ ≤ C) :
snormEssSup f μ ≤ ENNReal.ofReal C :=
snormEssSup_le_of_ae_nnnorm_bound <| hfC.mono fun _x hx => hx.trans C.le_coe_toNNReal
#align measure_theory.snorm_ess_sup_le_of_ae_bound MeasureTheory.snormEssSup_le_of_ae_bound
theorem snormEssSup_lt_top_of_ae_nnnorm_bound {f : α → F} {C : ℝ≥0} (hfC : ∀ᵐ x ∂μ, ‖f x‖₊ ≤ C) :
snormEssSup f μ < ∞ :=
(snormEssSup_le_of_ae_nnnorm_bound hfC).trans_lt ENNReal.coe_lt_top
#align measure_theory.snorm_ess_sup_lt_top_of_ae_nnnorm_bound MeasureTheory.snormEssSup_lt_top_of_ae_nnnorm_bound
theorem snormEssSup_lt_top_of_ae_bound {f : α → F} {C : ℝ} (hfC : ∀ᵐ x ∂μ, ‖f x‖ ≤ C) :
snormEssSup f μ < ∞ :=
(snormEssSup_le_of_ae_bound hfC).trans_lt ENNReal.ofReal_lt_top
#align measure_theory.snorm_ess_sup_lt_top_of_ae_bound MeasureTheory.snormEssSup_lt_top_of_ae_bound
theorem snorm_le_of_ae_nnnorm_bound {f : α → F} {C : ℝ≥0} (hfC : ∀ᵐ x ∂μ, ‖f x‖₊ ≤ C) :
snorm f p μ ≤ C • μ Set.univ ^ p.toReal⁻¹ := by
rcases eq_zero_or_neZero μ with rfl | hμ
· simp
by_cases hp : p = 0
· simp [hp]
have : ∀ᵐ x ∂μ, ‖f x‖₊ ≤ ‖(C : ℝ)‖₊ := hfC.mono fun x hx => hx.trans_eq C.nnnorm_eq.symm
refine (snorm_mono_ae this).trans_eq ?_
rw [snorm_const _ hp (NeZero.ne μ), C.nnnorm_eq, one_div, ENNReal.smul_def, smul_eq_mul]
#align measure_theory.snorm_le_of_ae_nnnorm_bound MeasureTheory.snorm_le_of_ae_nnnorm_bound
theorem snorm_le_of_ae_bound {f : α → F} {C : ℝ} (hfC : ∀ᵐ x ∂μ, ‖f x‖ ≤ C) :
snorm f p μ ≤ μ Set.univ ^ p.toReal⁻¹ * ENNReal.ofReal C := by
rw [← mul_comm]
exact snorm_le_of_ae_nnnorm_bound (hfC.mono fun x hx => hx.trans C.le_coe_toNNReal)
#align measure_theory.snorm_le_of_ae_bound MeasureTheory.snorm_le_of_ae_bound
theorem snorm_congr_nnnorm_ae {f : α → F} {g : α → G} (hfg : ∀ᵐ x ∂μ, ‖f x‖₊ = ‖g x‖₊) :
snorm f p μ = snorm g p μ :=
le_antisymm (snorm_mono_nnnorm_ae <| EventuallyEq.le hfg)
(snorm_mono_nnnorm_ae <| (EventuallyEq.symm hfg).le)
#align measure_theory.snorm_congr_nnnorm_ae MeasureTheory.snorm_congr_nnnorm_ae
theorem snorm_congr_norm_ae {f : α → F} {g : α → G} (hfg : ∀ᵐ x ∂μ, ‖f x‖ = ‖g x‖) :
snorm f p μ = snorm g p μ :=
snorm_congr_nnnorm_ae <| hfg.mono fun _x hx => NNReal.eq hx
#align measure_theory.snorm_congr_norm_ae MeasureTheory.snorm_congr_norm_ae
open scoped symmDiff in
theorem snorm_indicator_sub_indicator (s t : Set α) (f : α → E) :
snorm (s.indicator f - t.indicator f) p μ = snorm ((s ∆ t).indicator f) p μ :=
snorm_congr_norm_ae <| ae_of_all _ fun x ↦ by
simp only [Pi.sub_apply, Set.apply_indicator_symmDiff norm_neg]
@[simp]
theorem snorm'_norm {f : α → F} : snorm' (fun a => ‖f a‖) q μ = snorm' f q μ := by simp [snorm']
#align measure_theory.snorm'_norm MeasureTheory.snorm'_norm
@[simp]
theorem snorm_norm (f : α → F) : snorm (fun x => ‖f x‖) p μ = snorm f p μ :=
snorm_congr_norm_ae <| eventually_of_forall fun _ => norm_norm _
#align measure_theory.snorm_norm MeasureTheory.snorm_norm
theorem snorm'_norm_rpow (f : α → F) (p q : ℝ) (hq_pos : 0 < q) :
snorm' (fun x => ‖f x‖ ^ q) p μ = snorm' f (p * q) μ ^ q := by
simp_rw [snorm']
rw [← ENNReal.rpow_mul, ← one_div_mul_one_div]
simp_rw [one_div]
rw [mul_assoc, inv_mul_cancel hq_pos.ne.symm, mul_one]
congr
ext1 x
simp_rw [← ofReal_norm_eq_coe_nnnorm]
rw [Real.norm_eq_abs, abs_eq_self.mpr (Real.rpow_nonneg (norm_nonneg _) _), mul_comm, ←
ENNReal.ofReal_rpow_of_nonneg (norm_nonneg _) hq_pos.le, ENNReal.rpow_mul]
#align measure_theory.snorm'_norm_rpow MeasureTheory.snorm'_norm_rpow
theorem snorm_norm_rpow (f : α → F) (hq_pos : 0 < q) :
snorm (fun x => ‖f x‖ ^ q) p μ = snorm f (p * ENNReal.ofReal q) μ ^ q := by
by_cases h0 : p = 0
· simp [h0, ENNReal.zero_rpow_of_pos hq_pos]
by_cases hp_top : p = ∞
· simp only [hp_top, snorm_exponent_top, ENNReal.top_mul', hq_pos.not_le, ENNReal.ofReal_eq_zero,
if_false, snorm_exponent_top, snormEssSup]
have h_rpow :
essSup (fun x : α => (‖‖f x‖ ^ q‖₊ : ℝ≥0∞)) μ =
essSup (fun x : α => (‖f x‖₊ : ℝ≥0∞) ^ q) μ := by
congr
ext1 x
conv_rhs => rw [← nnnorm_norm]
rw [ENNReal.coe_rpow_of_nonneg _ hq_pos.le, ENNReal.coe_inj]
ext
push_cast
rw [Real.norm_rpow_of_nonneg (norm_nonneg _)]
rw [h_rpow]
have h_rpow_mono := ENNReal.strictMono_rpow_of_pos hq_pos
have h_rpow_surj := (ENNReal.rpow_left_bijective hq_pos.ne.symm).2
let iso := h_rpow_mono.orderIsoOfSurjective _ h_rpow_surj
exact (iso.essSup_apply (fun x => (‖f x‖₊ : ℝ≥0∞)) μ).symm
rw [snorm_eq_snorm' h0 hp_top, snorm_eq_snorm' _ _]
swap;
· refine mul_ne_zero h0 ?_
rwa [Ne, ENNReal.ofReal_eq_zero, not_le]
swap; · exact ENNReal.mul_ne_top hp_top ENNReal.ofReal_ne_top
rw [ENNReal.toReal_mul, ENNReal.toReal_ofReal hq_pos.le]
exact snorm'_norm_rpow f p.toReal q hq_pos
#align measure_theory.snorm_norm_rpow MeasureTheory.snorm_norm_rpow
theorem snorm_congr_ae {f g : α → F} (hfg : f =ᵐ[μ] g) : snorm f p μ = snorm g p μ :=
snorm_congr_norm_ae <| hfg.mono fun _x hx => hx ▸ rfl
#align measure_theory.snorm_congr_ae MeasureTheory.snorm_congr_ae
theorem memℒp_congr_ae {f g : α → E} (hfg : f =ᵐ[μ] g) : Memℒp f p μ ↔ Memℒp g p μ := by
simp only [Memℒp, snorm_congr_ae hfg, aestronglyMeasurable_congr hfg]
#align measure_theory.mem_ℒp_congr_ae MeasureTheory.memℒp_congr_ae
theorem Memℒp.ae_eq {f g : α → E} (hfg : f =ᵐ[μ] g) (hf_Lp : Memℒp f p μ) : Memℒp g p μ :=
(memℒp_congr_ae hfg).1 hf_Lp
#align measure_theory.mem_ℒp.ae_eq MeasureTheory.Memℒp.ae_eq
theorem Memℒp.of_le {f : α → E} {g : α → F} (hg : Memℒp g p μ) (hf : AEStronglyMeasurable f μ)
(hfg : ∀ᵐ x ∂μ, ‖f x‖ ≤ ‖g x‖) : Memℒp f p μ :=
⟨hf, (snorm_mono_ae hfg).trans_lt hg.snorm_lt_top⟩
#align measure_theory.mem_ℒp.of_le MeasureTheory.Memℒp.of_le
alias Memℒp.mono := Memℒp.of_le
#align measure_theory.mem_ℒp.mono MeasureTheory.Memℒp.mono
theorem Memℒp.mono' {f : α → E} {g : α → ℝ} (hg : Memℒp g p μ) (hf : AEStronglyMeasurable f μ)
(h : ∀ᵐ a ∂μ, ‖f a‖ ≤ g a) : Memℒp f p μ :=
hg.mono hf <| h.mono fun _x hx => le_trans hx (le_abs_self _)
#align measure_theory.mem_ℒp.mono' MeasureTheory.Memℒp.mono'
theorem Memℒp.congr_norm {f : α → E} {g : α → F} (hf : Memℒp f p μ) (hg : AEStronglyMeasurable g μ)
(h : ∀ᵐ a ∂μ, ‖f a‖ = ‖g a‖) : Memℒp g p μ :=
hf.mono hg <| EventuallyEq.le <| EventuallyEq.symm h
#align measure_theory.mem_ℒp.congr_norm MeasureTheory.Memℒp.congr_norm
theorem memℒp_congr_norm {f : α → E} {g : α → F} (hf : AEStronglyMeasurable f μ)
(hg : AEStronglyMeasurable g μ) (h : ∀ᵐ a ∂μ, ‖f a‖ = ‖g a‖) : Memℒp f p μ ↔ Memℒp g p μ :=
⟨fun h2f => h2f.congr_norm hg h, fun h2g => h2g.congr_norm hf <| EventuallyEq.symm h⟩
#align measure_theory.mem_ℒp_congr_norm MeasureTheory.memℒp_congr_norm
theorem memℒp_top_of_bound {f : α → E} (hf : AEStronglyMeasurable f μ) (C : ℝ)
(hfC : ∀ᵐ x ∂μ, ‖f x‖ ≤ C) : Memℒp f ∞ μ :=
⟨hf, by
rw [snorm_exponent_top]
exact snormEssSup_lt_top_of_ae_bound hfC⟩
#align measure_theory.mem_ℒp_top_of_bound MeasureTheory.memℒp_top_of_bound
theorem Memℒp.of_bound [IsFiniteMeasure μ] {f : α → E} (hf : AEStronglyMeasurable f μ) (C : ℝ)
(hfC : ∀ᵐ x ∂μ, ‖f x‖ ≤ C) : Memℒp f p μ :=
(memℒp_const C).of_le hf (hfC.mono fun _x hx => le_trans hx (le_abs_self _))
#align measure_theory.mem_ℒp.of_bound MeasureTheory.Memℒp.of_bound
@[mono]
theorem snorm'_mono_measure (f : α → F) (hμν : ν ≤ μ) (hq : 0 ≤ q) :
snorm' f q ν ≤ snorm' f q μ := by
simp_rw [snorm']
gcongr
exact lintegral_mono' hμν le_rfl
#align measure_theory.snorm'_mono_measure MeasureTheory.snorm'_mono_measure
@[mono]
theorem snormEssSup_mono_measure (f : α → F) (hμν : ν ≪ μ) : snormEssSup f ν ≤ snormEssSup f μ := by
simp_rw [snormEssSup]
exact essSup_mono_measure hμν
#align measure_theory.snorm_ess_sup_mono_measure MeasureTheory.snormEssSup_mono_measure
@[mono]
theorem snorm_mono_measure (f : α → F) (hμν : ν ≤ μ) : snorm f p ν ≤ snorm f p μ := by
by_cases hp0 : p = 0
· simp [hp0]
by_cases hp_top : p = ∞
· simp [hp_top, snormEssSup_mono_measure f (Measure.absolutelyContinuous_of_le hμν)]
simp_rw [snorm_eq_snorm' hp0 hp_top]
exact snorm'_mono_measure f hμν ENNReal.toReal_nonneg
#align measure_theory.snorm_mono_measure MeasureTheory.snorm_mono_measure
theorem Memℒp.mono_measure {f : α → E} (hμν : ν ≤ μ) (hf : Memℒp f p μ) : Memℒp f p ν :=
⟨hf.1.mono_measure hμν, (snorm_mono_measure f hμν).trans_lt hf.2⟩
#align measure_theory.mem_ℒp.mono_measure MeasureTheory.Memℒp.mono_measure
lemma snorm_restrict_le (f : α → F) (p : ℝ≥0∞) (μ : Measure α) (s : Set α) :
snorm f p (μ.restrict s) ≤ snorm f p μ :=
snorm_mono_measure f Measure.restrict_le_self
theorem Memℒp.restrict (s : Set α) {f : α → E} (hf : Memℒp f p μ) : Memℒp f p (μ.restrict s) :=
hf.mono_measure Measure.restrict_le_self
#align measure_theory.mem_ℒp.restrict MeasureTheory.Memℒp.restrict
theorem snorm'_smul_measure {p : ℝ} (hp : 0 ≤ p) {f : α → F} (c : ℝ≥0∞) :
snorm' f p (c • μ) = c ^ (1 / p) * snorm' f p μ := by
rw [snorm', lintegral_smul_measure, ENNReal.mul_rpow_of_nonneg, snorm']
simp [hp]
#align measure_theory.snorm'_smul_measure MeasureTheory.snorm'_smul_measure
theorem snormEssSup_smul_measure {f : α → F} {c : ℝ≥0∞} (hc : c ≠ 0) :
snormEssSup f (c • μ) = snormEssSup f μ := by
simp_rw [snormEssSup]
exact essSup_smul_measure hc
#align measure_theory.snorm_ess_sup_smul_measure MeasureTheory.snormEssSup_smul_measure
private theorem snorm_smul_measure_of_ne_zero_of_ne_top {p : ℝ≥0∞} (hp_ne_zero : p ≠ 0)
(hp_ne_top : p ≠ ∞) {f : α → F} (c : ℝ≥0∞) :
snorm f p (c • μ) = c ^ (1 / p).toReal • snorm f p μ := by
simp_rw [snorm_eq_snorm' hp_ne_zero hp_ne_top]
rw [snorm'_smul_measure ENNReal.toReal_nonneg]
congr
simp_rw [one_div]
rw [ENNReal.toReal_inv]
theorem snorm_smul_measure_of_ne_zero {p : ℝ≥0∞} {f : α → F} {c : ℝ≥0∞} (hc : c ≠ 0) :
snorm f p (c • μ) = c ^ (1 / p).toReal • snorm f p μ := by
by_cases hp0 : p = 0
· simp [hp0]
by_cases hp_top : p = ∞
· simp [hp_top, snormEssSup_smul_measure hc]
exact snorm_smul_measure_of_ne_zero_of_ne_top hp0 hp_top c
#align measure_theory.snorm_smul_measure_of_ne_zero MeasureTheory.snorm_smul_measure_of_ne_zero
theorem snorm_smul_measure_of_ne_top {p : ℝ≥0∞} (hp_ne_top : p ≠ ∞) {f : α → F} (c : ℝ≥0∞) :
snorm f p (c • μ) = c ^ (1 / p).toReal • snorm f p μ := by
by_cases hp0 : p = 0
· simp [hp0]
· exact snorm_smul_measure_of_ne_zero_of_ne_top hp0 hp_ne_top c
#align measure_theory.snorm_smul_measure_of_ne_top MeasureTheory.snorm_smul_measure_of_ne_top
theorem snorm_one_smul_measure {f : α → F} (c : ℝ≥0∞) : snorm f 1 (c • μ) = c * snorm f 1 μ := by
rw [@snorm_smul_measure_of_ne_top _ _ _ μ _ 1 (@ENNReal.coe_ne_top 1) f c]
simp
#align measure_theory.snorm_one_smul_measure MeasureTheory.snorm_one_smul_measure
theorem Memℒp.of_measure_le_smul {μ' : Measure α} (c : ℝ≥0∞) (hc : c ≠ ∞) (hμ'_le : μ' ≤ c • μ)
{f : α → E} (hf : Memℒp f p μ) : Memℒp f p μ' := by
refine ⟨hf.1.mono_ac (Measure.absolutelyContinuous_of_le_smul hμ'_le), ?_⟩
refine (snorm_mono_measure f hμ'_le).trans_lt ?_
by_cases hc0 : c = 0
· simp [hc0]
rw [snorm_smul_measure_of_ne_zero hc0, smul_eq_mul]
refine ENNReal.mul_lt_top ?_ hf.2.ne
simp [hc, hc0]
#align measure_theory.mem_ℒp.of_measure_le_smul MeasureTheory.Memℒp.of_measure_le_smul
theorem Memℒp.smul_measure {f : α → E} {c : ℝ≥0∞} (hf : Memℒp f p μ) (hc : c ≠ ∞) :
Memℒp f p (c • μ) :=
hf.of_measure_le_smul c hc le_rfl
#align measure_theory.mem_ℒp.smul_measure MeasureTheory.Memℒp.smul_measure
theorem snorm_one_add_measure (f : α → F) (μ ν : Measure α) :
snorm f 1 (μ + ν) = snorm f 1 μ + snorm f 1 ν := by
simp_rw [snorm_one_eq_lintegral_nnnorm]
rw [lintegral_add_measure _ μ ν]
#align measure_theory.snorm_one_add_measure MeasureTheory.snorm_one_add_measure
theorem snorm_le_add_measure_right (f : α → F) (μ ν : Measure α) {p : ℝ≥0∞} :
snorm f p μ ≤ snorm f p (μ + ν) :=
snorm_mono_measure f <| Measure.le_add_right <| le_refl _
#align measure_theory.snorm_le_add_measure_right MeasureTheory.snorm_le_add_measure_right
theorem snorm_le_add_measure_left (f : α → F) (μ ν : Measure α) {p : ℝ≥0∞} :
snorm f p ν ≤ snorm f p (μ + ν) :=
snorm_mono_measure f <| Measure.le_add_left <| le_refl _
#align measure_theory.snorm_le_add_measure_left MeasureTheory.snorm_le_add_measure_left
theorem Memℒp.left_of_add_measure {f : α → E} (h : Memℒp f p (μ + ν)) : Memℒp f p μ :=
h.mono_measure <| Measure.le_add_right <| le_refl _
#align measure_theory.mem_ℒp.left_of_add_measure MeasureTheory.Memℒp.left_of_add_measure
theorem Memℒp.right_of_add_measure {f : α → E} (h : Memℒp f p (μ + ν)) : Memℒp f p ν :=
h.mono_measure <| Measure.le_add_left <| le_refl _
#align measure_theory.mem_ℒp.right_of_add_measure MeasureTheory.Memℒp.right_of_add_measure
theorem Memℒp.norm {f : α → E} (h : Memℒp f p μ) : Memℒp (fun x => ‖f x‖) p μ :=
h.of_le h.aestronglyMeasurable.norm (eventually_of_forall fun x => by simp)
#align measure_theory.mem_ℒp.norm MeasureTheory.Memℒp.norm
theorem memℒp_norm_iff {f : α → E} (hf : AEStronglyMeasurable f μ) :
Memℒp (fun x => ‖f x‖) p μ ↔ Memℒp f p μ :=
⟨fun h => ⟨hf, by rw [← snorm_norm]; exact h.2⟩, fun h => h.norm⟩
#align measure_theory.mem_ℒp_norm_iff MeasureTheory.memℒp_norm_iff
theorem snorm'_eq_zero_of_ae_zero {f : α → F} (hq0_lt : 0 < q) (hf_zero : f =ᵐ[μ] 0) :
snorm' f q μ = 0 := by rw [snorm'_congr_ae hf_zero, snorm'_zero hq0_lt]
#align measure_theory.snorm'_eq_zero_of_ae_zero MeasureTheory.snorm'_eq_zero_of_ae_zero
| Mathlib/MeasureTheory/Function/LpSeminorm/Basic.lean | 721 | 722 | theorem snorm'_eq_zero_of_ae_zero' (hq0_ne : q ≠ 0) (hμ : μ ≠ 0) {f : α → F} (hf_zero : f =ᵐ[μ] 0) :
snorm' f q μ = 0 := by | rw [snorm'_congr_ae hf_zero, snorm'_zero' hq0_ne hμ]
|
import Mathlib.Algebra.Group.Indicator
import Mathlib.Algebra.Group.Submonoid.Basic
import Mathlib.Data.Set.Finite
#align_import data.finsupp.defs from "leanprover-community/mathlib"@"842328d9df7e96fd90fc424e115679c15fb23a71"
noncomputable section
open Finset Function
variable {α β γ ι M M' N P G H R S : Type*}
structure Finsupp (α : Type*) (M : Type*) [Zero M] where
support : Finset α
toFun : α → M
mem_support_toFun : ∀ a, a ∈ support ↔ toFun a ≠ 0
#align finsupp Finsupp
#align finsupp.support Finsupp.support
#align finsupp.to_fun Finsupp.toFun
#align finsupp.mem_support_to_fun Finsupp.mem_support_toFun
@[inherit_doc]
infixr:25 " →₀ " => Finsupp
namespace Finsupp
section Single
variable [Zero M] {a a' : α} {b : M}
def single (a : α) (b : M) : α →₀ M where
support :=
haveI := Classical.decEq M
if b = 0 then ∅ else {a}
toFun :=
haveI := Classical.decEq α
Pi.single a b
mem_support_toFun a' := by
classical
obtain rfl | hb := eq_or_ne b 0
· simp [Pi.single, update]
rw [if_neg hb, mem_singleton]
obtain rfl | ha := eq_or_ne a' a
· simp [hb, Pi.single, update]
simp [Pi.single_eq_of_ne' ha.symm, ha]
#align finsupp.single Finsupp.single
theorem single_apply [Decidable (a = a')] : single a b a' = if a = a' then b else 0 := by
classical
simp_rw [@eq_comm _ a a']
convert Pi.single_apply a b a'
#align finsupp.single_apply Finsupp.single_apply
theorem single_apply_left {f : α → β} (hf : Function.Injective f) (x z : α) (y : M) :
single (f x) y (f z) = single x y z := by classical simp only [single_apply, hf.eq_iff]
#align finsupp.single_apply_left Finsupp.single_apply_left
theorem single_eq_set_indicator : ⇑(single a b) = Set.indicator {a} fun _ => b := by
classical
ext
simp [single_apply, Set.indicator, @eq_comm _ a]
#align finsupp.single_eq_set_indicator Finsupp.single_eq_set_indicator
@[simp]
theorem single_eq_same : (single a b : α →₀ M) a = b := by
classical exact Pi.single_eq_same (f := fun _ ↦ M) a b
#align finsupp.single_eq_same Finsupp.single_eq_same
@[simp]
theorem single_eq_of_ne (h : a ≠ a') : (single a b : α →₀ M) a' = 0 := by
classical exact Pi.single_eq_of_ne' h _
#align finsupp.single_eq_of_ne Finsupp.single_eq_of_ne
theorem single_eq_update [DecidableEq α] (a : α) (b : M) :
⇑(single a b) = Function.update (0 : _) a b := by
classical rw [single_eq_set_indicator, ← Set.piecewise_eq_indicator, Set.piecewise_singleton]
#align finsupp.single_eq_update Finsupp.single_eq_update
theorem single_eq_pi_single [DecidableEq α] (a : α) (b : M) : ⇑(single a b) = Pi.single a b :=
single_eq_update a b
#align finsupp.single_eq_pi_single Finsupp.single_eq_pi_single
@[simp]
theorem single_zero (a : α) : (single a 0 : α →₀ M) = 0 :=
DFunLike.coe_injective <| by
classical simpa only [single_eq_update, coe_zero] using Function.update_eq_self a (0 : α → M)
#align finsupp.single_zero Finsupp.single_zero
theorem single_of_single_apply (a a' : α) (b : M) :
single a ((single a' b) a) = single a' (single a' b) a := by
classical
rw [single_apply, single_apply]
ext
split_ifs with h
· rw [h]
· rw [zero_apply, single_apply, ite_self]
#align finsupp.single_of_single_apply Finsupp.single_of_single_apply
theorem support_single_ne_zero (a : α) (hb : b ≠ 0) : (single a b).support = {a} :=
if_neg hb
#align finsupp.support_single_ne_zero Finsupp.support_single_ne_zero
theorem support_single_subset : (single a b).support ⊆ {a} := by
classical show ite _ _ _ ⊆ _; split_ifs <;> [exact empty_subset _; exact Subset.refl _]
#align finsupp.support_single_subset Finsupp.support_single_subset
| Mathlib/Data/Finsupp/Defs.lean | 346 | 347 | theorem single_apply_mem (x) : single a b x ∈ ({0, b} : Set M) := by |
rcases em (a = x) with (rfl | hx) <;> [simp; simp [single_eq_of_ne hx]]
|
import Mathlib.Data.DFinsupp.Lex
import Mathlib.Order.GameAdd
import Mathlib.Order.Antisymmetrization
import Mathlib.SetTheory.Ordinal.Basic
import Mathlib.Tactic.AdaptationNote
#align_import data.dfinsupp.well_founded from "leanprover-community/mathlib"@"e9b8651eb1ad354f4de6be35a38ef31efcd2cfaa"
variable {ι : Type*} {α : ι → Type*}
namespace DFinsupp
open Relation Prod
section Zero
variable [∀ i, Zero (α i)] (r : ι → ι → Prop) (s : ∀ i, α i → α i → Prop)
theorem lex_fibration [∀ (i) (s : Set ι), Decidable (i ∈ s)] :
Fibration (InvImage (GameAdd (DFinsupp.Lex r s) (DFinsupp.Lex r s)) snd) (DFinsupp.Lex r s)
fun x => piecewise x.2.1 x.2.2 x.1 := by
rintro ⟨p, x₁, x₂⟩ x ⟨i, hr, hs⟩
simp_rw [piecewise_apply] at hs hr
split_ifs at hs with hp
· refine ⟨⟨{ j | r j i → j ∈ p }, piecewise x₁ x { j | r j i }, x₂⟩,
.fst ⟨i, fun j hj ↦ ?_, ?_⟩, ?_⟩ <;> simp only [piecewise_apply, Set.mem_setOf_eq]
· simp only [if_pos hj]
· split_ifs with hi
· rwa [hr i hi, if_pos hp] at hs
· assumption
· ext1 j
simp only [piecewise_apply, Set.mem_setOf_eq]
split_ifs with h₁ h₂ <;> try rfl
· rw [hr j h₂, if_pos (h₁ h₂)]
· rw [Classical.not_imp] at h₁
rw [hr j h₁.1, if_neg h₁.2]
· refine ⟨⟨{ j | r j i ∧ j ∈ p }, x₁, piecewise x₂ x { j | r j i }⟩,
.snd ⟨i, fun j hj ↦ ?_, ?_⟩, ?_⟩ <;> simp only [piecewise_apply, Set.mem_setOf_eq]
· exact if_pos hj
· split_ifs with hi
· rwa [hr i hi, if_neg hp] at hs
· assumption
· ext1 j
simp only [piecewise_apply, Set.mem_setOf_eq]
split_ifs with h₁ h₂ <;> try rfl
· rw [hr j h₁.1, if_pos h₁.2]
· rw [hr j h₂, if_neg]
simpa [h₂] using h₁
#align dfinsupp.lex_fibration DFinsupp.lex_fibration
variable {r s}
| Mathlib/Data/DFinsupp/WellFounded.lean | 103 | 109 | theorem Lex.acc_of_single_erase [DecidableEq ι] {x : Π₀ i, α i} (i : ι)
(hs : Acc (DFinsupp.Lex r s) <| single i (x i)) (hu : Acc (DFinsupp.Lex r s) <| x.erase i) :
Acc (DFinsupp.Lex r s) x := by |
classical
convert ← @Acc.of_fibration _ _ _ _ _ (lex_fibration r s) ⟨{i}, _⟩
(InvImage.accessible snd <| hs.prod_gameAdd hu)
convert piecewise_single_erase x i
|
import Mathlib.CategoryTheory.Sites.Canonical
#align_import category_theory.sites.types from "leanprover-community/mathlib"@"9f9015c645d85695581237cc761981036be8bd37"
universe u
namespace CategoryTheory
--open scoped CategoryTheory.Type -- Porting note: unknown namespace
def typesGrothendieckTopology : GrothendieckTopology (Type u) where
sieves α S := ∀ x : α, S fun _ : PUnit => x
top_mem' _ _ := trivial
pullback_stable' _ _ _ f hs x := hs (f x)
transitive' _ _ hs _ hr x := hr (hs x) PUnit.unit
#align category_theory.types_grothendieck_topology CategoryTheory.typesGrothendieckTopology
@[simps]
def discreteSieve (α : Type u) : Sieve α where
arrows _ f := ∃ x, ∀ y, f y = x
downward_closed := fun ⟨x, hx⟩ g => ⟨x, fun y => hx <| g y⟩
#align category_theory.discrete_sieve CategoryTheory.discreteSieve
theorem discreteSieve_mem (α : Type u) : discreteSieve α ∈ typesGrothendieckTopology α :=
fun x => ⟨x, fun _ => rfl⟩
#align category_theory.discrete_sieve_mem CategoryTheory.discreteSieve_mem
def discretePresieve (α : Type u) : Presieve α :=
fun β _ => ∃ x : β, ∀ y : β, y = x
#align category_theory.discrete_presieve CategoryTheory.discretePresieve
theorem generate_discretePresieve_mem (α : Type u) :
Sieve.generate (discretePresieve α) ∈ typesGrothendieckTopology α :=
fun x => ⟨PUnit, id, fun _ => x, ⟨PUnit.unit, fun _ => Subsingleton.elim _ _⟩, rfl⟩
#align category_theory.generate_discrete_presieve_mem CategoryTheory.generate_discretePresieve_mem
open Presieve
theorem isSheaf_yoneda' {α : Type u} : IsSheaf typesGrothendieckTopology (yoneda.obj α) :=
fun β S hs x hx =>
⟨fun y => x _ (hs y) PUnit.unit, fun γ f h =>
funext fun z => by
convert congr_fun (hx (𝟙 _) (fun _ => z) (hs <| f z) h rfl) PUnit.unit using 1,
fun f hf => funext fun y => by convert congr_fun (hf _ (hs y)) PUnit.unit⟩
#align category_theory.is_sheaf_yoneda' CategoryTheory.isSheaf_yoneda'
@[simps]
def yoneda' : Type u ⥤ SheafOfTypes typesGrothendieckTopology where
obj α := ⟨yoneda.obj α, isSheaf_yoneda'⟩
map f := ⟨yoneda.map f⟩
#align category_theory.yoneda' CategoryTheory.yoneda'
@[simp]
theorem yoneda'_comp : yoneda'.{u} ⋙ sheafOfTypesToPresheaf _ = yoneda :=
rfl
#align category_theory.yoneda'_comp CategoryTheory.yoneda'_comp
open Opposite
def eval (P : Type uᵒᵖ ⥤ Type u) (α : Type u) (s : P.obj (op α)) (x : α) : P.obj (op PUnit) :=
P.map (↾fun _ => x).op s
#align category_theory.eval CategoryTheory.eval
noncomputable def typesGlue (S : Type uᵒᵖ ⥤ Type u) (hs : IsSheaf typesGrothendieckTopology S)
(α : Type u) (f : α → S.obj (op PUnit)) : S.obj (op α) :=
(hs.isSheafFor _ _ (generate_discretePresieve_mem α)).amalgamate
(fun β g hg => S.map (↾fun _ => PUnit.unit).op <| f <| g <| Classical.choose hg)
fun β γ δ g₁ g₂ f₁ f₂ hf₁ hf₂ h =>
(hs.isSheafFor _ _ (generate_discretePresieve_mem δ)).isSeparatedFor.ext fun ε g ⟨x, _⟩ => by
have : f₁ (Classical.choose hf₁) = f₂ (Classical.choose hf₂) :=
Classical.choose_spec hf₁ (g₁ <| g x) ▸
Classical.choose_spec hf₂ (g₂ <| g x) ▸ congr_fun h _
simp_rw [← FunctorToTypes.map_comp_apply, this, ← op_comp]
rfl
#align category_theory.types_glue CategoryTheory.typesGlue
theorem eval_typesGlue {S hs α} (f) : eval.{u} S α (typesGlue S hs α f) = f := by
funext x
apply (IsSheafFor.valid_glue _ _ _ <| ⟨PUnit.unit, fun _ => Subsingleton.elim _ _⟩).trans
convert FunctorToTypes.map_id_apply S _
#align category_theory.eval_types_glue CategoryTheory.eval_typesGlue
theorem typesGlue_eval {S hs α} (s) : typesGlue.{u} S hs α (eval S α s) = s := by
apply (hs.isSheafFor _ _ (generate_discretePresieve_mem α)).isSeparatedFor.ext
intro β f hf
apply (IsSheafFor.valid_glue _ _ _ hf).trans
apply (FunctorToTypes.map_comp_apply _ _ _ _).symm.trans
rw [← op_comp]
--congr 2 -- Porting note: This tactic didn't work. Find an alternative.
suffices ((↾fun _ ↦ PUnit.unit) ≫ ↾fun _ ↦ f (Classical.choose hf)) = f by rw [this]
funext x
exact congr_arg f (Classical.choose_spec hf x).symm
#align category_theory.types_glue_eval CategoryTheory.typesGlue_eval
@[simps]
noncomputable def evalEquiv (S : Type uᵒᵖ ⥤ Type u) (hs : IsSheaf typesGrothendieckTopology S)
(α : Type u) : S.obj (op α) ≃ (α → S.obj (op PUnit)) where
toFun := eval S α
invFun := typesGlue S hs α
left_inv := typesGlue_eval
right_inv := eval_typesGlue
#align category_theory.eval_equiv CategoryTheory.evalEquiv
theorem eval_map (S : Type uᵒᵖ ⥤ Type u) (α β) (f : β ⟶ α) (s x) :
eval S β (S.map f.op s) x = eval S α s (f x) := by
simp_rw [eval, ← FunctorToTypes.map_comp_apply, ← op_comp]; rfl
#align category_theory.eval_map CategoryTheory.eval_map
@[simps!]
noncomputable def equivYoneda (S : Type uᵒᵖ ⥤ Type u) (hs : IsSheaf typesGrothendieckTopology S) :
S ≅ yoneda.obj (S.obj (op PUnit)) :=
NatIso.ofComponents (fun α => Equiv.toIso <| evalEquiv S hs <| unop α) fun {α β} f =>
funext fun _ => funext fun _ => eval_map S (unop α) (unop β) f.unop _ _
#align category_theory.equiv_yoneda CategoryTheory.equivYoneda
@[simps]
noncomputable def equivYoneda' (S : SheafOfTypes typesGrothendieckTopology) :
S ≅ yoneda'.obj (S.1.obj (op PUnit)) where
hom := ⟨(equivYoneda S.1 S.2).hom⟩
inv := ⟨(equivYoneda S.1 S.2).inv⟩
hom_inv_id := by ext1; apply (equivYoneda S.1 S.2).hom_inv_id
inv_hom_id := by ext1; apply (equivYoneda S.1 S.2).inv_hom_id
#align category_theory.equiv_yoneda' CategoryTheory.equivYoneda'
theorem eval_app (S₁ S₂ : SheafOfTypes.{u} typesGrothendieckTopology) (f : S₁ ⟶ S₂) (α : Type u)
(s : S₁.1.obj (op α)) (x : α) :
eval S₂.1 α (f.val.app (op α) s) x = f.val.app (op PUnit) (eval S₁.1 α s x) :=
(congr_fun (f.val.naturality (↾fun _ : PUnit => x).op) s).symm
#align category_theory.eval_app CategoryTheory.eval_app
@[simps!]
noncomputable def typeEquiv : Type u ≌ SheafOfTypes typesGrothendieckTopology :=
Equivalence.mk yoneda' (sheafOfTypesToPresheaf _ ⋙ (evaluation _ _).obj (op PUnit))
(NatIso.ofComponents
(fun _α => -- α ≅ PUnit ⟶ α
{ hom := fun x _ => x
inv := fun f => f PUnit.unit
hom_inv_id := funext fun _ => rfl
inv_hom_id := funext fun _ => funext fun y => PUnit.casesOn y rfl })
fun _ => rfl)
(Iso.symm <|
NatIso.ofComponents (fun S => equivYoneda' S) fun {S₁ S₂} f =>
SheafOfTypes.Hom.ext _ _ <|
NatTrans.ext _ _ <|
funext fun α => funext fun s => funext fun x => eval_app S₁ S₂ f (unop α) s x)
#align category_theory.type_equiv CategoryTheory.typeEquiv
theorem subcanonical_typesGrothendieckTopology : Sheaf.Subcanonical typesGrothendieckTopology.{u} :=
Sheaf.Subcanonical.of_yoneda_isSheaf _ fun _ => isSheaf_yoneda'
#align category_theory.subcanonical_types_grothendieck_topology CategoryTheory.subcanonical_typesGrothendieckTopology
| Mathlib/CategoryTheory/Sites/Types.lean | 182 | 193 | theorem typesGrothendieckTopology_eq_canonical :
typesGrothendieckTopology.{u} = Sheaf.canonicalTopology (Type u) := by |
refine le_antisymm subcanonical_typesGrothendieckTopology (sInf_le ?_)
refine ⟨yoneda.obj (ULift Bool), ⟨_, rfl⟩, GrothendieckTopology.ext ?_⟩
funext α
ext S
refine ⟨fun hs x => ?_, fun hs β f => isSheaf_yoneda' _ fun y => hs _⟩
by_contra hsx
have : (fun _ => ULift.up true) = fun _ => ULift.up false :=
(hs PUnit fun _ => x).isSeparatedFor.ext
fun β f hf => funext fun y => hsx.elim <| S.2 hf fun _ => y
simp [Function.funext_iff] at this
|
import Mathlib.RingTheory.Algebraic
import Mathlib.RingTheory.Localization.AtPrime
import Mathlib.RingTheory.Localization.Integral
#align_import ring_theory.ideal.over from "leanprover-community/mathlib"@"198cb64d5c961e1a8d0d3e219feb7058d5353861"
variable {R : Type*} [CommRing R]
namespace Ideal
open Polynomial
open Polynomial
open Submodule
section IsDomain
variable {S : Type*} [CommRing S] {f : R →+* S} {I J : Ideal S}
theorem exists_coeff_ne_zero_mem_comap_of_root_mem [IsDomain S] {r : S} (r_ne_zero : r ≠ 0)
(hr : r ∈ I) {p : R[X]} :
p ≠ 0 → p.eval₂ f r = 0 → ∃ i, p.coeff i ≠ 0 ∧ p.coeff i ∈ I.comap f :=
exists_coeff_ne_zero_mem_comap_of_non_zero_divisor_root_mem
(fun {_} h => Or.resolve_right (mul_eq_zero.mp h) r_ne_zero) hr
#align ideal.exists_coeff_ne_zero_mem_comap_of_root_mem Ideal.exists_coeff_ne_zero_mem_comap_of_root_mem
theorem exists_coeff_mem_comap_sdiff_comap_of_root_mem_sdiff [IsPrime I] (hIJ : I ≤ J) {r : S}
(hr : r ∈ (J : Set S) \ I) {p : R[X]} (p_ne_zero : p.map (Quotient.mk (I.comap f)) ≠ 0)
(hpI : p.eval₂ f r ∈ I) : ∃ i, p.coeff i ∈ (J.comap f : Set R) \ I.comap f := by
obtain ⟨hrJ, hrI⟩ := hr
have rbar_ne_zero : Ideal.Quotient.mk I r ≠ 0 := mt (Quotient.mk_eq_zero I).mp hrI
have rbar_mem_J : Ideal.Quotient.mk I r ∈ J.map (Ideal.Quotient.mk I) := mem_map_of_mem _ hrJ
have quotient_f : ∀ x ∈ I.comap f, (Ideal.Quotient.mk I).comp f x = 0 := by
simp [Quotient.eq_zero_iff_mem]
have rbar_root :
(p.map (Ideal.Quotient.mk (I.comap f))).eval₂ (Quotient.lift (I.comap f) _ quotient_f)
(Ideal.Quotient.mk I r) =
0 := by
convert Quotient.eq_zero_iff_mem.mpr hpI
exact _root_.trans (eval₂_map _ _ _) (hom_eval₂ p f (Ideal.Quotient.mk I) r).symm
obtain ⟨i, ne_zero, mem⟩ :=
exists_coeff_ne_zero_mem_comap_of_root_mem rbar_ne_zero rbar_mem_J p_ne_zero rbar_root
rw [coeff_map] at ne_zero mem
refine ⟨i, (mem_quotient_iff_mem hIJ).mp ?_, mt ?_ ne_zero⟩
· simpa using mem
simp [Quotient.eq_zero_iff_mem]
#align ideal.exists_coeff_mem_comap_sdiff_comap_of_root_mem_sdiff Ideal.exists_coeff_mem_comap_sdiff_comap_of_root_mem_sdiff
theorem comap_lt_comap_of_root_mem_sdiff [I.IsPrime] (hIJ : I ≤ J) {r : S}
(hr : r ∈ (J : Set S) \ I) {p : R[X]} (p_ne_zero : p.map (Quotient.mk (I.comap f)) ≠ 0)
(hp : p.eval₂ f r ∈ I) : I.comap f < J.comap f :=
let ⟨i, hJ, hI⟩ := exists_coeff_mem_comap_sdiff_comap_of_root_mem_sdiff hIJ hr p_ne_zero hp
SetLike.lt_iff_le_and_exists.mpr ⟨comap_mono hIJ, p.coeff i, hJ, hI⟩
#align ideal.comap_lt_comap_of_root_mem_sdiff Ideal.comap_lt_comap_of_root_mem_sdiff
theorem mem_of_one_mem (h : (1 : S) ∈ I) (x) : x ∈ I :=
(I.eq_top_iff_one.mpr h).symm ▸ mem_top
#align ideal.mem_of_one_mem Ideal.mem_of_one_mem
| Mathlib/RingTheory/Ideal/Over.lean | 235 | 240 | theorem comap_lt_comap_of_integral_mem_sdiff [Algebra R S] [hI : I.IsPrime] (hIJ : I ≤ J) {x : S}
(mem : x ∈ (J : Set S) \ I) (integral : IsIntegral R x) :
I.comap (algebraMap R S) < J.comap (algebraMap R S) := by |
obtain ⟨p, p_monic, hpx⟩ := integral
refine comap_lt_comap_of_root_mem_sdiff hIJ mem (map_monic_ne_zero p_monic) ?_
convert I.zero_mem
|
import Mathlib.Algebra.Group.Indicator
import Mathlib.Algebra.Group.Submonoid.Basic
import Mathlib.Data.Set.Finite
#align_import data.finsupp.defs from "leanprover-community/mathlib"@"842328d9df7e96fd90fc424e115679c15fb23a71"
noncomputable section
open Finset Function
variable {α β γ ι M M' N P G H R S : Type*}
structure Finsupp (α : Type*) (M : Type*) [Zero M] where
support : Finset α
toFun : α → M
mem_support_toFun : ∀ a, a ∈ support ↔ toFun a ≠ 0
#align finsupp Finsupp
#align finsupp.support Finsupp.support
#align finsupp.to_fun Finsupp.toFun
#align finsupp.mem_support_to_fun Finsupp.mem_support_toFun
@[inherit_doc]
infixr:25 " →₀ " => Finsupp
namespace Finsupp
section Update
variable [Zero M] (f : α →₀ M) (a : α) (b : M) (i : α)
def update (f : α →₀ M) (a : α) (b : M) : α →₀ M where
support := by
haveI := Classical.decEq α; haveI := Classical.decEq M
exact if b = 0 then f.support.erase a else insert a f.support
toFun :=
haveI := Classical.decEq α
Function.update f a b
mem_support_toFun i := by
classical
rw [Function.update]
simp only [eq_rec_constant, dite_eq_ite, ne_eq]
split_ifs with hb ha ha <;>
try simp only [*, not_false_iff, iff_true, not_true, iff_false]
· rw [Finset.mem_erase]
simp
· rw [Finset.mem_erase]
simp [ha]
· rw [Finset.mem_insert]
simp [ha]
· rw [Finset.mem_insert]
simp [ha]
#align finsupp.update Finsupp.update
@[simp, norm_cast]
theorem coe_update [DecidableEq α] : (f.update a b : α → M) = Function.update f a b := by
delta update Function.update
ext
dsimp
split_ifs <;> simp
#align finsupp.coe_update Finsupp.coe_update
@[simp]
| Mathlib/Data/Finsupp/Defs.lean | 555 | 558 | theorem update_self : f.update a (f a) = f := by |
classical
ext
simp
|
import Aesop
import Mathlib.Algebra.Group.Defs
import Mathlib.Data.Nat.Defs
import Mathlib.Data.Int.Defs
import Mathlib.Logic.Function.Basic
import Mathlib.Tactic.Cases
import Mathlib.Tactic.SimpRw
import Mathlib.Tactic.SplitIfs
#align_import algebra.group.basic from "leanprover-community/mathlib"@"a07d750983b94c530ab69a726862c2ab6802b38c"
assert_not_exists MonoidWithZero
assert_not_exists DenselyOrdered
open Function
universe u
variable {α β G M : Type*}
@[to_additive]
instance CommMagma.to_isCommutative [CommMagma G] : Std.Commutative (α := G) (· * ·) := ⟨mul_comm⟩
#align comm_semigroup.to_is_commutative CommMagma.to_isCommutative
#align add_comm_semigroup.to_is_commutative AddCommMagma.to_isCommutative
attribute [local simp] mul_assoc sub_eq_add_neg
section DivisionMonoid
variable [DivisionMonoid α] {a b c d : α}
attribute [local simp] mul_assoc div_eq_mul_inv
@[to_additive]
theorem eq_inv_of_mul_eq_one_right (h : a * b = 1) : b = a⁻¹ :=
(inv_eq_of_mul_eq_one_right h).symm
#align eq_inv_of_mul_eq_one_right eq_inv_of_mul_eq_one_right
#align eq_neg_of_add_eq_zero_right eq_neg_of_add_eq_zero_right
@[to_additive]
theorem eq_one_div_of_mul_eq_one_left (h : b * a = 1) : b = 1 / a := by
rw [eq_inv_of_mul_eq_one_left h, one_div]
#align eq_one_div_of_mul_eq_one_left eq_one_div_of_mul_eq_one_left
#align eq_zero_sub_of_add_eq_zero_left eq_zero_sub_of_add_eq_zero_left
@[to_additive]
theorem eq_one_div_of_mul_eq_one_right (h : a * b = 1) : b = 1 / a := by
rw [eq_inv_of_mul_eq_one_right h, one_div]
#align eq_one_div_of_mul_eq_one_right eq_one_div_of_mul_eq_one_right
#align eq_zero_sub_of_add_eq_zero_right eq_zero_sub_of_add_eq_zero_right
@[to_additive]
theorem eq_of_div_eq_one (h : a / b = 1) : a = b :=
inv_injective <| inv_eq_of_mul_eq_one_right <| by rwa [← div_eq_mul_inv]
#align eq_of_div_eq_one eq_of_div_eq_one
#align eq_of_sub_eq_zero eq_of_sub_eq_zero
lemma eq_of_inv_mul_eq_one (h : a⁻¹ * b = 1) : a = b := by simpa using eq_inv_of_mul_eq_one_left h
lemma eq_of_mul_inv_eq_one (h : a * b⁻¹ = 1) : a = b := by simpa using eq_inv_of_mul_eq_one_left h
@[to_additive]
theorem div_ne_one_of_ne : a ≠ b → a / b ≠ 1 :=
mt eq_of_div_eq_one
#align div_ne_one_of_ne div_ne_one_of_ne
#align sub_ne_zero_of_ne sub_ne_zero_of_ne
variable (a b c)
@[to_additive]
| Mathlib/Algebra/Group/Basic.lean | 544 | 544 | theorem one_div_mul_one_div_rev : 1 / a * (1 / b) = 1 / (b * a) := by | simp
|
import Mathlib.Order.MinMax
import Mathlib.Data.Set.Subsingleton
import Mathlib.Tactic.Says
#align_import data.set.intervals.basic from "leanprover-community/mathlib"@"3ba15165bd6927679be7c22d6091a87337e3cd0c"
open Function
open OrderDual (toDual ofDual)
variable {α β : Type*}
namespace Set
theorem Icc_bot_top [PartialOrder α] [BoundedOrder α] : Icc (⊥ : α) ⊤ = univ := by simp
#align set.Icc_bot_top Set.Icc_bot_top
section Lattice
section LinearOrder
variable [LinearOrder α] [LinearOrder β] {f : α → β} {a a₁ a₂ b b₁ b₂ c d : α}
@[simp]
theorem Ioi_inter_Ioi : Ioi a ∩ Ioi b = Ioi (a ⊔ b) :=
ext fun _ => sup_lt_iff.symm
#align set.Ioi_inter_Ioi Set.Ioi_inter_Ioi
@[simp]
theorem Iio_inter_Iio : Iio a ∩ Iio b = Iio (a ⊓ b) :=
ext fun _ => lt_inf_iff.symm
#align set.Iio_inter_Iio Set.Iio_inter_Iio
theorem Ico_inter_Ico : Ico a₁ b₁ ∩ Ico a₂ b₂ = Ico (a₁ ⊔ a₂) (b₁ ⊓ b₂) := by
simp only [Ici_inter_Iio.symm, Ici_inter_Ici.symm, Iio_inter_Iio.symm]; ac_rfl
#align set.Ico_inter_Ico Set.Ico_inter_Ico
theorem Ioc_inter_Ioc : Ioc a₁ b₁ ∩ Ioc a₂ b₂ = Ioc (a₁ ⊔ a₂) (b₁ ⊓ b₂) := by
simp only [Ioi_inter_Iic.symm, Ioi_inter_Ioi.symm, Iic_inter_Iic.symm]; ac_rfl
#align set.Ioc_inter_Ioc Set.Ioc_inter_Ioc
| Mathlib/Order/Interval/Set/Basic.lean | 1,834 | 1,835 | theorem Ioo_inter_Ioo : Ioo a₁ b₁ ∩ Ioo a₂ b₂ = Ioo (a₁ ⊔ a₂) (b₁ ⊓ b₂) := by |
simp only [Ioi_inter_Iio.symm, Ioi_inter_Ioi.symm, Iio_inter_Iio.symm]; ac_rfl
|
import Mathlib.Algebra.Group.Opposite
import Mathlib.Algebra.FreeMonoid.Basic
import Mathlib.Control.Traversable.Instances
import Mathlib.Control.Traversable.Lemmas
import Mathlib.CategoryTheory.Endomorphism
import Mathlib.CategoryTheory.Types
import Mathlib.CategoryTheory.Category.KleisliCat
import Mathlib.Tactic.AdaptationNote
#align_import control.fold from "leanprover-community/mathlib"@"740acc0e6f9adf4423f92a485d0456fc271482da"
universe u v
open ULift CategoryTheory MulOpposite
namespace Traversable
open Monoid Functor
section Equalities
open LawfulTraversable
open List (cons)
variable {α β γ : Type u}
variable {t : Type u → Type u} [Traversable t] [LawfulTraversable t]
@[simp]
theorem foldl.ofFreeMonoid_comp_of (f : α → β → α) :
Foldl.ofFreeMonoid f ∘ FreeMonoid.of = Foldl.mk ∘ flip f :=
rfl
#align traversable.foldl.of_free_monoid_comp_of Traversable.foldl.ofFreeMonoid_comp_of
@[simp]
theorem foldr.ofFreeMonoid_comp_of (f : β → α → α) :
Foldr.ofFreeMonoid f ∘ FreeMonoid.of = Foldr.mk ∘ f :=
rfl
#align traversable.foldr.of_free_monoid_comp_of Traversable.foldr.ofFreeMonoid_comp_of
@[simp]
| Mathlib/Control/Fold.lean | 313 | 322 | theorem foldlm.ofFreeMonoid_comp_of {m} [Monad m] [LawfulMonad m] (f : α → β → m α) :
foldlM.ofFreeMonoid f ∘ FreeMonoid.of = foldlM.mk ∘ flip f := by |
ext1 x
#adaptation_note /-- nightly-2024-03-16: simp was
simp only [foldlM.ofFreeMonoid, flip, MonoidHom.coe_mk, OneHom.coe_mk, Function.comp_apply,
FreeMonoid.toList_of, List.foldlM_cons, List.foldlM_nil, bind_pure, foldlM.mk, op_inj] -/
simp only [foldlM.ofFreeMonoid, Function.flip_def, MonoidHom.coe_mk, OneHom.coe_mk,
Function.comp_apply, FreeMonoid.toList_of, List.foldlM_cons, List.foldlM_nil, bind_pure,
foldlM.mk, op_inj]
rfl
|
import Mathlib.Data.Set.Image
import Mathlib.Order.SuccPred.Relation
import Mathlib.Topology.Clopen
import Mathlib.Topology.Irreducible
#align_import topology.connected from "leanprover-community/mathlib"@"d101e93197bb5f6ea89bd7ba386b7f7dff1f3903"
open Set Function Topology TopologicalSpace Relation
open scoped Classical
universe u v
variable {α : Type u} {β : Type v} {ι : Type*} {π : ι → Type*} [TopologicalSpace α]
{s t u v : Set α}
section Preconnected
def IsPreconnected (s : Set α) : Prop :=
∀ u v : Set α, IsOpen u → IsOpen v → s ⊆ u ∪ v → (s ∩ u).Nonempty → (s ∩ v).Nonempty →
(s ∩ (u ∩ v)).Nonempty
#align is_preconnected IsPreconnected
def IsConnected (s : Set α) : Prop :=
s.Nonempty ∧ IsPreconnected s
#align is_connected IsConnected
theorem IsConnected.nonempty {s : Set α} (h : IsConnected s) : s.Nonempty :=
h.1
#align is_connected.nonempty IsConnected.nonempty
theorem IsConnected.isPreconnected {s : Set α} (h : IsConnected s) : IsPreconnected s :=
h.2
#align is_connected.is_preconnected IsConnected.isPreconnected
theorem IsPreirreducible.isPreconnected {s : Set α} (H : IsPreirreducible s) : IsPreconnected s :=
fun _ _ hu hv _ => H _ _ hu hv
#align is_preirreducible.is_preconnected IsPreirreducible.isPreconnected
theorem IsIrreducible.isConnected {s : Set α} (H : IsIrreducible s) : IsConnected s :=
⟨H.nonempty, H.isPreirreducible.isPreconnected⟩
#align is_irreducible.is_connected IsIrreducible.isConnected
theorem isPreconnected_empty : IsPreconnected (∅ : Set α) :=
isPreirreducible_empty.isPreconnected
#align is_preconnected_empty isPreconnected_empty
theorem isConnected_singleton {x} : IsConnected ({x} : Set α) :=
isIrreducible_singleton.isConnected
#align is_connected_singleton isConnected_singleton
theorem isPreconnected_singleton {x} : IsPreconnected ({x} : Set α) :=
isConnected_singleton.isPreconnected
#align is_preconnected_singleton isPreconnected_singleton
theorem Set.Subsingleton.isPreconnected {s : Set α} (hs : s.Subsingleton) : IsPreconnected s :=
hs.induction_on isPreconnected_empty fun _ => isPreconnected_singleton
#align set.subsingleton.is_preconnected Set.Subsingleton.isPreconnected
theorem isPreconnected_of_forall {s : Set α} (x : α)
(H : ∀ y ∈ s, ∃ t, t ⊆ s ∧ x ∈ t ∧ y ∈ t ∧ IsPreconnected t) : IsPreconnected s := by
rintro u v hu hv hs ⟨z, zs, zu⟩ ⟨y, ys, yv⟩
have xs : x ∈ s := by
rcases H y ys with ⟨t, ts, xt, -, -⟩
exact ts xt
-- Porting note (#11215): TODO: use `wlog xu : x ∈ u := hs xs using u v y z, v u z y`
cases hs xs with
| inl xu =>
rcases H y ys with ⟨t, ts, xt, yt, ht⟩
have := ht u v hu hv (ts.trans hs) ⟨x, xt, xu⟩ ⟨y, yt, yv⟩
exact this.imp fun z hz => ⟨ts hz.1, hz.2⟩
| inr xv =>
rcases H z zs with ⟨t, ts, xt, zt, ht⟩
have := ht v u hv hu (ts.trans <| by rwa [union_comm]) ⟨x, xt, xv⟩ ⟨z, zt, zu⟩
exact this.imp fun _ h => ⟨ts h.1, h.2.2, h.2.1⟩
#align is_preconnected_of_forall isPreconnected_of_forall
theorem isPreconnected_of_forall_pair {s : Set α}
(H : ∀ x ∈ s, ∀ y ∈ s, ∃ t, t ⊆ s ∧ x ∈ t ∧ y ∈ t ∧ IsPreconnected t) :
IsPreconnected s := by
rcases eq_empty_or_nonempty s with (rfl | ⟨x, hx⟩)
exacts [isPreconnected_empty, isPreconnected_of_forall x fun y => H x hx y]
#align is_preconnected_of_forall_pair isPreconnected_of_forall_pair
theorem isPreconnected_sUnion (x : α) (c : Set (Set α)) (H1 : ∀ s ∈ c, x ∈ s)
(H2 : ∀ s ∈ c, IsPreconnected s) : IsPreconnected (⋃₀ c) := by
apply isPreconnected_of_forall x
rintro y ⟨s, sc, ys⟩
exact ⟨s, subset_sUnion_of_mem sc, H1 s sc, ys, H2 s sc⟩
#align is_preconnected_sUnion isPreconnected_sUnion
theorem isPreconnected_iUnion {ι : Sort*} {s : ι → Set α} (h₁ : (⋂ i, s i).Nonempty)
(h₂ : ∀ i, IsPreconnected (s i)) : IsPreconnected (⋃ i, s i) :=
Exists.elim h₁ fun f hf => isPreconnected_sUnion f _ hf (forall_mem_range.2 h₂)
#align is_preconnected_Union isPreconnected_iUnion
theorem IsPreconnected.union (x : α) {s t : Set α} (H1 : x ∈ s) (H2 : x ∈ t) (H3 : IsPreconnected s)
(H4 : IsPreconnected t) : IsPreconnected (s ∪ t) :=
sUnion_pair s t ▸ isPreconnected_sUnion x {s, t} (by rintro r (rfl | rfl | h) <;> assumption)
(by rintro r (rfl | rfl | h) <;> assumption)
#align is_preconnected.union IsPreconnected.union
theorem IsPreconnected.union' {s t : Set α} (H : (s ∩ t).Nonempty) (hs : IsPreconnected s)
(ht : IsPreconnected t) : IsPreconnected (s ∪ t) := by
rcases H with ⟨x, hxs, hxt⟩
exact hs.union x hxs hxt ht
#align is_preconnected.union' IsPreconnected.union'
theorem IsConnected.union {s t : Set α} (H : (s ∩ t).Nonempty) (Hs : IsConnected s)
(Ht : IsConnected t) : IsConnected (s ∪ t) := by
rcases H with ⟨x, hx⟩
refine ⟨⟨x, mem_union_left t (mem_of_mem_inter_left hx)⟩, ?_⟩
exact Hs.isPreconnected.union x (mem_of_mem_inter_left hx) (mem_of_mem_inter_right hx)
Ht.isPreconnected
#align is_connected.union IsConnected.union
theorem IsPreconnected.sUnion_directed {S : Set (Set α)} (K : DirectedOn (· ⊆ ·) S)
(H : ∀ s ∈ S, IsPreconnected s) : IsPreconnected (⋃₀ S) := by
rintro u v hu hv Huv ⟨a, ⟨s, hsS, has⟩, hau⟩ ⟨b, ⟨t, htS, hbt⟩, hbv⟩
obtain ⟨r, hrS, hsr, htr⟩ : ∃ r ∈ S, s ⊆ r ∧ t ⊆ r := K s hsS t htS
have Hnuv : (r ∩ (u ∩ v)).Nonempty :=
H _ hrS u v hu hv ((subset_sUnion_of_mem hrS).trans Huv) ⟨a, hsr has, hau⟩ ⟨b, htr hbt, hbv⟩
have Kruv : r ∩ (u ∩ v) ⊆ ⋃₀ S ∩ (u ∩ v) := inter_subset_inter_left _ (subset_sUnion_of_mem hrS)
exact Hnuv.mono Kruv
#align is_preconnected.sUnion_directed IsPreconnected.sUnion_directed
theorem IsPreconnected.biUnion_of_reflTransGen {ι : Type*} {t : Set ι} {s : ι → Set α}
(H : ∀ i ∈ t, IsPreconnected (s i))
(K : ∀ i, i ∈ t → ∀ j, j ∈ t → ReflTransGen (fun i j => (s i ∩ s j).Nonempty ∧ i ∈ t) i j) :
IsPreconnected (⋃ n ∈ t, s n) := by
let R := fun i j : ι => (s i ∩ s j).Nonempty ∧ i ∈ t
have P : ∀ i, i ∈ t → ∀ j, j ∈ t → ReflTransGen R i j →
∃ p, p ⊆ t ∧ i ∈ p ∧ j ∈ p ∧ IsPreconnected (⋃ j ∈ p, s j) := fun i hi j hj h => by
induction h with
| refl =>
refine ⟨{i}, singleton_subset_iff.mpr hi, mem_singleton i, mem_singleton i, ?_⟩
rw [biUnion_singleton]
exact H i hi
| @tail j k _ hjk ih =>
obtain ⟨p, hpt, hip, hjp, hp⟩ := ih hjk.2
refine ⟨insert k p, insert_subset_iff.mpr ⟨hj, hpt⟩, mem_insert_of_mem k hip,
mem_insert k p, ?_⟩
rw [biUnion_insert]
refine (H k hj).union' (hjk.1.mono ?_) hp
rw [inter_comm]
exact inter_subset_inter_right _ (subset_biUnion_of_mem hjp)
refine isPreconnected_of_forall_pair ?_
intro x hx y hy
obtain ⟨i : ι, hi : i ∈ t, hxi : x ∈ s i⟩ := mem_iUnion₂.1 hx
obtain ⟨j : ι, hj : j ∈ t, hyj : y ∈ s j⟩ := mem_iUnion₂.1 hy
obtain ⟨p, hpt, hip, hjp, hp⟩ := P i hi j hj (K i hi j hj)
exact ⟨⋃ j ∈ p, s j, biUnion_subset_biUnion_left hpt, mem_biUnion hip hxi,
mem_biUnion hjp hyj, hp⟩
#align is_preconnected.bUnion_of_refl_trans_gen IsPreconnected.biUnion_of_reflTransGen
theorem IsConnected.biUnion_of_reflTransGen {ι : Type*} {t : Set ι} {s : ι → Set α}
(ht : t.Nonempty) (H : ∀ i ∈ t, IsConnected (s i))
(K : ∀ i, i ∈ t → ∀ j, j ∈ t → ReflTransGen (fun i j : ι => (s i ∩ s j).Nonempty ∧ i ∈ t) i j) :
IsConnected (⋃ n ∈ t, s n) :=
⟨nonempty_biUnion.2 <| ⟨ht.some, ht.some_mem, (H _ ht.some_mem).nonempty⟩,
IsPreconnected.biUnion_of_reflTransGen (fun i hi => (H i hi).isPreconnected) K⟩
#align is_connected.bUnion_of_refl_trans_gen IsConnected.biUnion_of_reflTransGen
theorem IsPreconnected.iUnion_of_reflTransGen {ι : Type*} {s : ι → Set α}
(H : ∀ i, IsPreconnected (s i))
(K : ∀ i j, ReflTransGen (fun i j : ι => (s i ∩ s j).Nonempty) i j) :
IsPreconnected (⋃ n, s n) := by
rw [← biUnion_univ]
exact IsPreconnected.biUnion_of_reflTransGen (fun i _ => H i) fun i _ j _ => by
simpa [mem_univ] using K i j
#align is_preconnected.Union_of_refl_trans_gen IsPreconnected.iUnion_of_reflTransGen
theorem IsConnected.iUnion_of_reflTransGen {ι : Type*} [Nonempty ι] {s : ι → Set α}
(H : ∀ i, IsConnected (s i))
(K : ∀ i j, ReflTransGen (fun i j : ι => (s i ∩ s j).Nonempty) i j) : IsConnected (⋃ n, s n) :=
⟨nonempty_iUnion.2 <| Nonempty.elim ‹_› fun i : ι => ⟨i, (H _).nonempty⟩,
IsPreconnected.iUnion_of_reflTransGen (fun i => (H i).isPreconnected) K⟩
#align is_connected.Union_of_refl_trans_gen IsConnected.iUnion_of_reflTransGen
protected theorem IsPreconnected.subset_closure {s : Set α} {t : Set α} (H : IsPreconnected s)
(Kst : s ⊆ t) (Ktcs : t ⊆ closure s) : IsPreconnected t :=
fun u v hu hv htuv ⟨_y, hyt, hyu⟩ ⟨_z, hzt, hzv⟩ =>
let ⟨p, hpu, hps⟩ := mem_closure_iff.1 (Ktcs hyt) u hu hyu
let ⟨q, hqv, hqs⟩ := mem_closure_iff.1 (Ktcs hzt) v hv hzv
let ⟨r, hrs, hruv⟩ := H u v hu hv (Subset.trans Kst htuv) ⟨p, hps, hpu⟩ ⟨q, hqs, hqv⟩
⟨r, Kst hrs, hruv⟩
#align is_preconnected.subset_closure IsPreconnected.subset_closure
protected theorem IsConnected.subset_closure {s : Set α} {t : Set α} (H : IsConnected s)
(Kst : s ⊆ t) (Ktcs : t ⊆ closure s) : IsConnected t :=
⟨Nonempty.mono Kst H.left, IsPreconnected.subset_closure H.right Kst Ktcs⟩
#align is_connected.subset_closure IsConnected.subset_closure
protected theorem IsPreconnected.closure {s : Set α} (H : IsPreconnected s) :
IsPreconnected (closure s) :=
IsPreconnected.subset_closure H subset_closure Subset.rfl
#align is_preconnected.closure IsPreconnected.closure
protected theorem IsConnected.closure {s : Set α} (H : IsConnected s) : IsConnected (closure s) :=
IsConnected.subset_closure H subset_closure <| Subset.rfl
#align is_connected.closure IsConnected.closure
protected theorem IsPreconnected.image [TopologicalSpace β] {s : Set α} (H : IsPreconnected s)
(f : α → β) (hf : ContinuousOn f s) : IsPreconnected (f '' s) := by
-- Unfold/destruct definitions in hypotheses
rintro u v hu hv huv ⟨_, ⟨x, xs, rfl⟩, xu⟩ ⟨_, ⟨y, ys, rfl⟩, yv⟩
rcases continuousOn_iff'.1 hf u hu with ⟨u', hu', u'_eq⟩
rcases continuousOn_iff'.1 hf v hv with ⟨v', hv', v'_eq⟩
-- Reformulate `huv : f '' s ⊆ u ∪ v` in terms of `u'` and `v'`
replace huv : s ⊆ u' ∪ v' := by
rw [image_subset_iff, preimage_union] at huv
replace huv := subset_inter huv Subset.rfl
rw [union_inter_distrib_right, u'_eq, v'_eq, ← union_inter_distrib_right] at huv
exact (subset_inter_iff.1 huv).1
-- Now `s ⊆ u' ∪ v'`, so we can apply `‹IsPreconnected s›`
obtain ⟨z, hz⟩ : (s ∩ (u' ∩ v')).Nonempty := by
refine H u' v' hu' hv' huv ⟨x, ?_⟩ ⟨y, ?_⟩ <;> rw [inter_comm]
exacts [u'_eq ▸ ⟨xu, xs⟩, v'_eq ▸ ⟨yv, ys⟩]
rw [← inter_self s, inter_assoc, inter_left_comm s u', ← inter_assoc, inter_comm s, inter_comm s,
← u'_eq, ← v'_eq] at hz
exact ⟨f z, ⟨z, hz.1.2, rfl⟩, hz.1.1, hz.2.1⟩
#align is_preconnected.image IsPreconnected.image
protected theorem IsConnected.image [TopologicalSpace β] {s : Set α} (H : IsConnected s) (f : α → β)
(hf : ContinuousOn f s) : IsConnected (f '' s) :=
⟨image_nonempty.mpr H.nonempty, H.isPreconnected.image f hf⟩
#align is_connected.image IsConnected.image
theorem isPreconnected_closed_iff {s : Set α} :
IsPreconnected s ↔ ∀ t t', IsClosed t → IsClosed t' →
s ⊆ t ∪ t' → (s ∩ t).Nonempty → (s ∩ t').Nonempty → (s ∩ (t ∩ t')).Nonempty :=
⟨by
rintro h t t' ht ht' htt' ⟨x, xs, xt⟩ ⟨y, ys, yt'⟩
rw [← not_disjoint_iff_nonempty_inter, ← subset_compl_iff_disjoint_right, compl_inter]
intro h'
have xt' : x ∉ t' := (h' xs).resolve_left (absurd xt)
have yt : y ∉ t := (h' ys).resolve_right (absurd yt')
have := h _ _ ht.isOpen_compl ht'.isOpen_compl h' ⟨y, ys, yt⟩ ⟨x, xs, xt'⟩
rw [← compl_union] at this
exact this.ne_empty htt'.disjoint_compl_right.inter_eq,
by
rintro h u v hu hv huv ⟨x, xs, xu⟩ ⟨y, ys, yv⟩
rw [← not_disjoint_iff_nonempty_inter, ← subset_compl_iff_disjoint_right, compl_inter]
intro h'
have xv : x ∉ v := (h' xs).elim (absurd xu) id
have yu : y ∉ u := (h' ys).elim id (absurd yv)
have := h _ _ hu.isClosed_compl hv.isClosed_compl h' ⟨y, ys, yu⟩ ⟨x, xs, xv⟩
rw [← compl_union] at this
exact this.ne_empty huv.disjoint_compl_right.inter_eq⟩
#align is_preconnected_closed_iff isPreconnected_closed_iff
theorem Inducing.isPreconnected_image [TopologicalSpace β] {s : Set α} {f : α → β}
(hf : Inducing f) : IsPreconnected (f '' s) ↔ IsPreconnected s := by
refine ⟨fun h => ?_, fun h => h.image _ hf.continuous.continuousOn⟩
rintro u v hu' hv' huv ⟨x, hxs, hxu⟩ ⟨y, hys, hyv⟩
rcases hf.isOpen_iff.1 hu' with ⟨u, hu, rfl⟩
rcases hf.isOpen_iff.1 hv' with ⟨v, hv, rfl⟩
replace huv : f '' s ⊆ u ∪ v := by rwa [image_subset_iff]
rcases h u v hu hv huv ⟨f x, mem_image_of_mem _ hxs, hxu⟩ ⟨f y, mem_image_of_mem _ hys, hyv⟩ with
⟨_, ⟨z, hzs, rfl⟩, hzuv⟩
exact ⟨z, hzs, hzuv⟩
#align inducing.is_preconnected_image Inducing.isPreconnected_image
theorem IsPreconnected.preimage_of_isOpenMap [TopologicalSpace β] {f : α → β} {s : Set β}
(hs : IsPreconnected s) (hinj : Function.Injective f) (hf : IsOpenMap f) (hsf : s ⊆ range f) :
IsPreconnected (f ⁻¹' s) := fun u v hu hv hsuv hsu hsv => by
replace hsf : f '' (f ⁻¹' s) = s := image_preimage_eq_of_subset hsf
obtain ⟨_, has, ⟨a, hau, rfl⟩, hav⟩ : (s ∩ (f '' u ∩ f '' v)).Nonempty := by
refine hs (f '' u) (f '' v) (hf u hu) (hf v hv) ?_ ?_ ?_
· simpa only [hsf, image_union] using image_subset f hsuv
· simpa only [image_preimage_inter] using hsu.image f
· simpa only [image_preimage_inter] using hsv.image f
· exact ⟨a, has, hau, hinj.mem_set_image.1 hav⟩
#align is_preconnected.preimage_of_open_map IsPreconnected.preimage_of_isOpenMap
theorem IsPreconnected.preimage_of_isClosedMap [TopologicalSpace β] {s : Set β}
(hs : IsPreconnected s) {f : α → β} (hinj : Function.Injective f) (hf : IsClosedMap f)
(hsf : s ⊆ range f) : IsPreconnected (f ⁻¹' s) :=
isPreconnected_closed_iff.2 fun u v hu hv hsuv hsu hsv => by
replace hsf : f '' (f ⁻¹' s) = s := image_preimage_eq_of_subset hsf
obtain ⟨_, has, ⟨a, hau, rfl⟩, hav⟩ : (s ∩ (f '' u ∩ f '' v)).Nonempty := by
refine isPreconnected_closed_iff.1 hs (f '' u) (f '' v) (hf u hu) (hf v hv) ?_ ?_ ?_
· simpa only [hsf, image_union] using image_subset f hsuv
· simpa only [image_preimage_inter] using hsu.image f
· simpa only [image_preimage_inter] using hsv.image f
· exact ⟨a, has, hau, hinj.mem_set_image.1 hav⟩
#align is_preconnected.preimage_of_closed_map IsPreconnected.preimage_of_isClosedMap
theorem IsConnected.preimage_of_isOpenMap [TopologicalSpace β] {s : Set β} (hs : IsConnected s)
{f : α → β} (hinj : Function.Injective f) (hf : IsOpenMap f) (hsf : s ⊆ range f) :
IsConnected (f ⁻¹' s) :=
⟨hs.nonempty.preimage' hsf, hs.isPreconnected.preimage_of_isOpenMap hinj hf hsf⟩
#align is_connected.preimage_of_open_map IsConnected.preimage_of_isOpenMap
theorem IsConnected.preimage_of_isClosedMap [TopologicalSpace β] {s : Set β} (hs : IsConnected s)
{f : α → β} (hinj : Function.Injective f) (hf : IsClosedMap f) (hsf : s ⊆ range f) :
IsConnected (f ⁻¹' s) :=
⟨hs.nonempty.preimage' hsf, hs.isPreconnected.preimage_of_isClosedMap hinj hf hsf⟩
#align is_connected.preimage_of_closed_map IsConnected.preimage_of_isClosedMap
theorem IsPreconnected.subset_or_subset (hu : IsOpen u) (hv : IsOpen v) (huv : Disjoint u v)
(hsuv : s ⊆ u ∪ v) (hs : IsPreconnected s) : s ⊆ u ∨ s ⊆ v := by
specialize hs u v hu hv hsuv
obtain hsu | hsu := (s ∩ u).eq_empty_or_nonempty
· exact Or.inr ((Set.disjoint_iff_inter_eq_empty.2 hsu).subset_right_of_subset_union hsuv)
· replace hs := mt (hs hsu)
simp_rw [Set.not_nonempty_iff_eq_empty, ← Set.disjoint_iff_inter_eq_empty,
disjoint_iff_inter_eq_empty.1 huv] at hs
exact Or.inl ((hs s.disjoint_empty).subset_left_of_subset_union hsuv)
#align is_preconnected.subset_or_subset IsPreconnected.subset_or_subset
theorem IsPreconnected.subset_left_of_subset_union (hu : IsOpen u) (hv : IsOpen v)
(huv : Disjoint u v) (hsuv : s ⊆ u ∪ v) (hsu : (s ∩ u).Nonempty) (hs : IsPreconnected s) :
s ⊆ u :=
Disjoint.subset_left_of_subset_union hsuv
(by
by_contra hsv
rw [not_disjoint_iff_nonempty_inter] at hsv
obtain ⟨x, _, hx⟩ := hs u v hu hv hsuv hsu hsv
exact Set.disjoint_iff.1 huv hx)
#align is_preconnected.subset_left_of_subset_union IsPreconnected.subset_left_of_subset_union
theorem IsPreconnected.subset_right_of_subset_union (hu : IsOpen u) (hv : IsOpen v)
(huv : Disjoint u v) (hsuv : s ⊆ u ∪ v) (hsv : (s ∩ v).Nonempty) (hs : IsPreconnected s) :
s ⊆ v :=
hs.subset_left_of_subset_union hv hu huv.symm (union_comm u v ▸ hsuv) hsv
#align is_preconnected.subset_right_of_subset_union IsPreconnected.subset_right_of_subset_union
-- Porting note: moved up
theorem IsPreconnected.subset_isClopen {s t : Set α} (hs : IsPreconnected s) (ht : IsClopen t)
(hne : (s ∩ t).Nonempty) : s ⊆ t :=
hs.subset_left_of_subset_union ht.isOpen ht.compl.isOpen disjoint_compl_right (by simp) hne
#align is_preconnected.subset_clopen IsPreconnected.subset_isClopen
theorem IsPreconnected.subset_of_closure_inter_subset (hs : IsPreconnected s) (hu : IsOpen u)
(h'u : (s ∩ u).Nonempty) (h : closure u ∩ s ⊆ u) : s ⊆ u := by
have A : s ⊆ u ∪ (closure u)ᶜ := by
intro x hx
by_cases xu : x ∈ u
· exact Or.inl xu
· right
intro h'x
exact xu (h (mem_inter h'x hx))
apply hs.subset_left_of_subset_union hu isClosed_closure.isOpen_compl _ A h'u
exact disjoint_compl_right.mono_right (compl_subset_compl.2 subset_closure)
#align is_preconnected.subset_of_closure_inter_subset IsPreconnected.subset_of_closure_inter_subset
theorem IsPreconnected.prod [TopologicalSpace β] {s : Set α} {t : Set β} (hs : IsPreconnected s)
(ht : IsPreconnected t) : IsPreconnected (s ×ˢ t) := by
apply isPreconnected_of_forall_pair
rintro ⟨a₁, b₁⟩ ⟨ha₁, hb₁⟩ ⟨a₂, b₂⟩ ⟨ha₂, hb₂⟩
refine ⟨Prod.mk a₁ '' t ∪ flip Prod.mk b₂ '' s, ?_, .inl ⟨b₁, hb₁, rfl⟩, .inr ⟨a₂, ha₂, rfl⟩, ?_⟩
· rintro _ (⟨y, hy, rfl⟩ | ⟨x, hx, rfl⟩)
exacts [⟨ha₁, hy⟩, ⟨hx, hb₂⟩]
· exact (ht.image _ (Continuous.Prod.mk _).continuousOn).union (a₁, b₂) ⟨b₂, hb₂, rfl⟩
⟨a₁, ha₁, rfl⟩ (hs.image _ (continuous_id.prod_mk continuous_const).continuousOn)
#align is_preconnected.prod IsPreconnected.prod
theorem IsConnected.prod [TopologicalSpace β] {s : Set α} {t : Set β} (hs : IsConnected s)
(ht : IsConnected t) : IsConnected (s ×ˢ t) :=
⟨hs.1.prod ht.1, hs.2.prod ht.2⟩
#align is_connected.prod IsConnected.prod
theorem isPreconnected_univ_pi [∀ i, TopologicalSpace (π i)] {s : ∀ i, Set (π i)}
(hs : ∀ i, IsPreconnected (s i)) : IsPreconnected (pi univ s) := by
rintro u v uo vo hsuv ⟨f, hfs, hfu⟩ ⟨g, hgs, hgv⟩
rcases exists_finset_piecewise_mem_of_mem_nhds (uo.mem_nhds hfu) g with ⟨I, hI⟩
induction' I using Finset.induction_on with i I _ ihI
· refine ⟨g, hgs, ⟨?_, hgv⟩⟩
simpa using hI
· rw [Finset.piecewise_insert] at hI
have := I.piecewise_mem_set_pi hfs hgs
refine (hsuv this).elim ihI fun h => ?_
set S := update (I.piecewise f g) i '' s i
have hsub : S ⊆ pi univ s := by
refine image_subset_iff.2 fun z hz => ?_
rwa [update_preimage_univ_pi]
exact fun j _ => this j trivial
have hconn : IsPreconnected S :=
(hs i).image _ (continuous_const.update i continuous_id).continuousOn
have hSu : (S ∩ u).Nonempty := ⟨_, mem_image_of_mem _ (hfs _ trivial), hI⟩
have hSv : (S ∩ v).Nonempty := ⟨_, ⟨_, this _ trivial, update_eq_self _ _⟩, h⟩
refine (hconn u v uo vo (hsub.trans hsuv) hSu hSv).mono ?_
exact inter_subset_inter_left _ hsub
#align is_preconnected_univ_pi isPreconnected_univ_pi
@[simp]
theorem isConnected_univ_pi [∀ i, TopologicalSpace (π i)] {s : ∀ i, Set (π i)} :
IsConnected (pi univ s) ↔ ∀ i, IsConnected (s i) := by
simp only [IsConnected, ← univ_pi_nonempty_iff, forall_and, and_congr_right_iff]
refine fun hne => ⟨fun hc i => ?_, isPreconnected_univ_pi⟩
rw [← eval_image_univ_pi hne]
exact hc.image _ (continuous_apply _).continuousOn
#align is_connected_univ_pi isConnected_univ_pi
theorem Sigma.isConnected_iff [∀ i, TopologicalSpace (π i)] {s : Set (Σi, π i)} :
IsConnected s ↔ ∃ i t, IsConnected t ∧ s = Sigma.mk i '' t := by
refine ⟨fun hs => ?_, ?_⟩
· obtain ⟨⟨i, x⟩, hx⟩ := hs.nonempty
have : s ⊆ range (Sigma.mk i) :=
hs.isPreconnected.subset_isClopen isClopen_range_sigmaMk ⟨⟨i, x⟩, hx, x, rfl⟩
exact ⟨i, Sigma.mk i ⁻¹' s, hs.preimage_of_isOpenMap sigma_mk_injective isOpenMap_sigmaMk this,
(Set.image_preimage_eq_of_subset this).symm⟩
· rintro ⟨i, t, ht, rfl⟩
exact ht.image _ continuous_sigmaMk.continuousOn
#align sigma.is_connected_iff Sigma.isConnected_iff
theorem Sigma.isPreconnected_iff [hι : Nonempty ι] [∀ i, TopologicalSpace (π i)]
{s : Set (Σi, π i)} : IsPreconnected s ↔ ∃ i t, IsPreconnected t ∧ s = Sigma.mk i '' t := by
refine ⟨fun hs => ?_, ?_⟩
· obtain rfl | h := s.eq_empty_or_nonempty
· exact ⟨Classical.choice hι, ∅, isPreconnected_empty, (Set.image_empty _).symm⟩
· obtain ⟨a, t, ht, rfl⟩ := Sigma.isConnected_iff.1 ⟨h, hs⟩
exact ⟨a, t, ht.isPreconnected, rfl⟩
· rintro ⟨a, t, ht, rfl⟩
exact ht.image _ continuous_sigmaMk.continuousOn
#align sigma.is_preconnected_iff Sigma.isPreconnected_iff
theorem Sum.isConnected_iff [TopologicalSpace β] {s : Set (Sum α β)} :
IsConnected s ↔
(∃ t, IsConnected t ∧ s = Sum.inl '' t) ∨ ∃ t, IsConnected t ∧ s = Sum.inr '' t := by
refine ⟨fun hs => ?_, ?_⟩
· obtain ⟨x | x, hx⟩ := hs.nonempty
· have h : s ⊆ range Sum.inl :=
hs.isPreconnected.subset_isClopen isClopen_range_inl ⟨.inl x, hx, x, rfl⟩
refine Or.inl ⟨Sum.inl ⁻¹' s, ?_, ?_⟩
· exact hs.preimage_of_isOpenMap Sum.inl_injective isOpenMap_inl h
· exact (image_preimage_eq_of_subset h).symm
· have h : s ⊆ range Sum.inr :=
hs.isPreconnected.subset_isClopen isClopen_range_inr ⟨.inr x, hx, x, rfl⟩
refine Or.inr ⟨Sum.inr ⁻¹' s, ?_, ?_⟩
· exact hs.preimage_of_isOpenMap Sum.inr_injective isOpenMap_inr h
· exact (image_preimage_eq_of_subset h).symm
· rintro (⟨t, ht, rfl⟩ | ⟨t, ht, rfl⟩)
· exact ht.image _ continuous_inl.continuousOn
· exact ht.image _ continuous_inr.continuousOn
#align sum.is_connected_iff Sum.isConnected_iff
theorem Sum.isPreconnected_iff [TopologicalSpace β] {s : Set (Sum α β)} :
IsPreconnected s ↔
(∃ t, IsPreconnected t ∧ s = Sum.inl '' t) ∨ ∃ t, IsPreconnected t ∧ s = Sum.inr '' t := by
refine ⟨fun hs => ?_, ?_⟩
· obtain rfl | h := s.eq_empty_or_nonempty
· exact Or.inl ⟨∅, isPreconnected_empty, (Set.image_empty _).symm⟩
obtain ⟨t, ht, rfl⟩ | ⟨t, ht, rfl⟩ := Sum.isConnected_iff.1 ⟨h, hs⟩
· exact Or.inl ⟨t, ht.isPreconnected, rfl⟩
· exact Or.inr ⟨t, ht.isPreconnected, rfl⟩
· rintro (⟨t, ht, rfl⟩ | ⟨t, ht, rfl⟩)
· exact ht.image _ continuous_inl.continuousOn
· exact ht.image _ continuous_inr.continuousOn
#align sum.is_preconnected_iff Sum.isPreconnected_iff
def connectedComponent (x : α) : Set α :=
⋃₀ { s : Set α | IsPreconnected s ∧ x ∈ s }
#align connected_component connectedComponent
def connectedComponentIn (F : Set α) (x : α) : Set α :=
if h : x ∈ F then (↑) '' connectedComponent (⟨x, h⟩ : F) else ∅
#align connected_component_in connectedComponentIn
theorem connectedComponentIn_eq_image {F : Set α} {x : α} (h : x ∈ F) :
connectedComponentIn F x = (↑) '' connectedComponent (⟨x, h⟩ : F) :=
dif_pos h
#align connected_component_in_eq_image connectedComponentIn_eq_image
theorem connectedComponentIn_eq_empty {F : Set α} {x : α} (h : x ∉ F) :
connectedComponentIn F x = ∅ :=
dif_neg h
#align connected_component_in_eq_empty connectedComponentIn_eq_empty
theorem mem_connectedComponent {x : α} : x ∈ connectedComponent x :=
mem_sUnion_of_mem (mem_singleton x) ⟨isPreconnected_singleton, mem_singleton x⟩
#align mem_connected_component mem_connectedComponent
theorem mem_connectedComponentIn {x : α} {F : Set α} (hx : x ∈ F) :
x ∈ connectedComponentIn F x := by
simp [connectedComponentIn_eq_image hx, mem_connectedComponent, hx]
#align mem_connected_component_in mem_connectedComponentIn
theorem connectedComponent_nonempty {x : α} : (connectedComponent x).Nonempty :=
⟨x, mem_connectedComponent⟩
#align connected_component_nonempty connectedComponent_nonempty
theorem connectedComponentIn_nonempty_iff {x : α} {F : Set α} :
(connectedComponentIn F x).Nonempty ↔ x ∈ F := by
rw [connectedComponentIn]
split_ifs <;> simp [connectedComponent_nonempty, *]
#align connected_component_in_nonempty_iff connectedComponentIn_nonempty_iff
theorem connectedComponentIn_subset (F : Set α) (x : α) : connectedComponentIn F x ⊆ F := by
rw [connectedComponentIn]
split_ifs <;> simp
#align connected_component_in_subset connectedComponentIn_subset
theorem isPreconnected_connectedComponent {x : α} : IsPreconnected (connectedComponent x) :=
isPreconnected_sUnion x _ (fun _ => And.right) fun _ => And.left
#align is_preconnected_connected_component isPreconnected_connectedComponent
theorem isPreconnected_connectedComponentIn {x : α} {F : Set α} :
IsPreconnected (connectedComponentIn F x) := by
rw [connectedComponentIn]; split_ifs
· exact inducing_subtype_val.isPreconnected_image.mpr isPreconnected_connectedComponent
· exact isPreconnected_empty
#align is_preconnected_connected_component_in isPreconnected_connectedComponentIn
theorem isConnected_connectedComponent {x : α} : IsConnected (connectedComponent x) :=
⟨⟨x, mem_connectedComponent⟩, isPreconnected_connectedComponent⟩
#align is_connected_connected_component isConnected_connectedComponent
theorem isConnected_connectedComponentIn_iff {x : α} {F : Set α} :
IsConnected (connectedComponentIn F x) ↔ x ∈ F := by
simp_rw [← connectedComponentIn_nonempty_iff, IsConnected, isPreconnected_connectedComponentIn,
and_true_iff]
#align is_connected_connected_component_in_iff isConnected_connectedComponentIn_iff
theorem IsPreconnected.subset_connectedComponent {x : α} {s : Set α} (H1 : IsPreconnected s)
(H2 : x ∈ s) : s ⊆ connectedComponent x := fun _z hz => mem_sUnion_of_mem hz ⟨H1, H2⟩
#align is_preconnected.subset_connected_component IsPreconnected.subset_connectedComponent
theorem IsPreconnected.subset_connectedComponentIn {x : α} {F : Set α} (hs : IsPreconnected s)
(hxs : x ∈ s) (hsF : s ⊆ F) : s ⊆ connectedComponentIn F x := by
have : IsPreconnected (((↑) : F → α) ⁻¹' s) := by
refine inducing_subtype_val.isPreconnected_image.mp ?_
rwa [Subtype.image_preimage_coe, inter_eq_right.mpr hsF]
have h2xs : (⟨x, hsF hxs⟩ : F) ∈ (↑) ⁻¹' s := by
rw [mem_preimage]
exact hxs
have := this.subset_connectedComponent h2xs
rw [connectedComponentIn_eq_image (hsF hxs)]
refine Subset.trans ?_ (image_subset _ this)
rw [Subtype.image_preimage_coe, inter_eq_right.mpr hsF]
#align is_preconnected.subset_connected_component_in IsPreconnected.subset_connectedComponentIn
theorem IsConnected.subset_connectedComponent {x : α} {s : Set α} (H1 : IsConnected s)
(H2 : x ∈ s) : s ⊆ connectedComponent x :=
H1.2.subset_connectedComponent H2
#align is_connected.subset_connected_component IsConnected.subset_connectedComponent
theorem IsPreconnected.connectedComponentIn {x : α} {F : Set α} (h : IsPreconnected F)
(hx : x ∈ F) : connectedComponentIn F x = F :=
(connectedComponentIn_subset F x).antisymm (h.subset_connectedComponentIn hx subset_rfl)
#align is_preconnected.connected_component_in IsPreconnected.connectedComponentIn
theorem connectedComponent_eq {x y : α} (h : y ∈ connectedComponent x) :
connectedComponent x = connectedComponent y :=
eq_of_subset_of_subset (isConnected_connectedComponent.subset_connectedComponent h)
(isConnected_connectedComponent.subset_connectedComponent
(Set.mem_of_mem_of_subset mem_connectedComponent
(isConnected_connectedComponent.subset_connectedComponent h)))
#align connected_component_eq connectedComponent_eq
theorem connectedComponent_eq_iff_mem {x y : α} :
connectedComponent x = connectedComponent y ↔ x ∈ connectedComponent y :=
⟨fun h => h ▸ mem_connectedComponent, fun h => (connectedComponent_eq h).symm⟩
#align connected_component_eq_iff_mem connectedComponent_eq_iff_mem
theorem connectedComponentIn_eq {x y : α} {F : Set α} (h : y ∈ connectedComponentIn F x) :
connectedComponentIn F x = connectedComponentIn F y := by
have hx : x ∈ F := connectedComponentIn_nonempty_iff.mp ⟨y, h⟩
simp_rw [connectedComponentIn_eq_image hx] at h ⊢
obtain ⟨⟨y, hy⟩, h2y, rfl⟩ := h
simp_rw [connectedComponentIn_eq_image hy, connectedComponent_eq h2y]
#align connected_component_in_eq connectedComponentIn_eq
theorem connectedComponentIn_univ (x : α) : connectedComponentIn univ x = connectedComponent x :=
subset_antisymm
(isPreconnected_connectedComponentIn.subset_connectedComponent <|
mem_connectedComponentIn trivial)
(isPreconnected_connectedComponent.subset_connectedComponentIn mem_connectedComponent <|
subset_univ _)
#align connected_component_in_univ connectedComponentIn_univ
theorem connectedComponent_disjoint {x y : α} (h : connectedComponent x ≠ connectedComponent y) :
Disjoint (connectedComponent x) (connectedComponent y) :=
Set.disjoint_left.2 fun _ h1 h2 =>
h ((connectedComponent_eq h1).trans (connectedComponent_eq h2).symm)
#align connected_component_disjoint connectedComponent_disjoint
theorem isClosed_connectedComponent {x : α} : IsClosed (connectedComponent x) :=
closure_subset_iff_isClosed.1 <|
isConnected_connectedComponent.closure.subset_connectedComponent <|
subset_closure mem_connectedComponent
#align is_closed_connected_component isClosed_connectedComponent
theorem Continuous.image_connectedComponent_subset [TopologicalSpace β] {f : α → β}
(h : Continuous f) (a : α) : f '' connectedComponent a ⊆ connectedComponent (f a) :=
(isConnected_connectedComponent.image f h.continuousOn).subset_connectedComponent
((mem_image f (connectedComponent a) (f a)).2 ⟨a, mem_connectedComponent, rfl⟩)
#align continuous.image_connected_component_subset Continuous.image_connectedComponent_subset
theorem Continuous.image_connectedComponentIn_subset [TopologicalSpace β] {f : α → β} {s : Set α}
{a : α} (hf : Continuous f) (hx : a ∈ s) :
f '' connectedComponentIn s a ⊆ connectedComponentIn (f '' s) (f a) :=
(isPreconnected_connectedComponentIn.image _ hf.continuousOn).subset_connectedComponentIn
(mem_image_of_mem _ <| mem_connectedComponentIn hx)
(image_subset _ <| connectedComponentIn_subset _ _)
theorem Continuous.mapsTo_connectedComponent [TopologicalSpace β] {f : α → β} (h : Continuous f)
(a : α) : MapsTo f (connectedComponent a) (connectedComponent (f a)) :=
mapsTo'.2 <| h.image_connectedComponent_subset a
#align continuous.maps_to_connected_component Continuous.mapsTo_connectedComponent
theorem Continuous.mapsTo_connectedComponentIn [TopologicalSpace β] {f : α → β} {s : Set α}
(h : Continuous f) {a : α} (hx : a ∈ s) :
MapsTo f (connectedComponentIn s a) (connectedComponentIn (f '' s) (f a)) :=
mapsTo'.2 <| image_connectedComponentIn_subset h hx
theorem irreducibleComponent_subset_connectedComponent {x : α} :
irreducibleComponent x ⊆ connectedComponent x :=
isIrreducible_irreducibleComponent.isConnected.subset_connectedComponent mem_irreducibleComponent
#align irreducible_component_subset_connected_component irreducibleComponent_subset_connectedComponent
@[mono]
| Mathlib/Topology/Connected/Basic.lean | 735 | 742 | theorem connectedComponentIn_mono (x : α) {F G : Set α} (h : F ⊆ G) :
connectedComponentIn F x ⊆ connectedComponentIn G x := by |
by_cases hx : x ∈ F
· rw [connectedComponentIn_eq_image hx, connectedComponentIn_eq_image (h hx), ←
show ((↑) : G → α) ∘ inclusion h = (↑) from rfl, image_comp]
exact image_subset _ ((continuous_inclusion h).image_connectedComponent_subset ⟨x, hx⟩)
· rw [connectedComponentIn_eq_empty hx]
exact Set.empty_subset _
|
import Mathlib.CategoryTheory.Comma.Over
import Mathlib.CategoryTheory.DiscreteCategory
import Mathlib.CategoryTheory.EpiMono
import Mathlib.CategoryTheory.Limits.Shapes.Terminal
#align_import category_theory.limits.shapes.binary_products from "leanprover-community/mathlib"@"fec1d95fc61c750c1ddbb5b1f7f48b8e811a80d7"
noncomputable section
universe v u u₂
open CategoryTheory
namespace CategoryTheory.Limits
inductive WalkingPair : Type
| left
| right
deriving DecidableEq, Inhabited
#align category_theory.limits.walking_pair CategoryTheory.Limits.WalkingPair
open WalkingPair
def WalkingPair.swap : WalkingPair ≃ WalkingPair where
toFun j := WalkingPair.recOn j right left
invFun j := WalkingPair.recOn j right left
left_inv j := by cases j; repeat rfl
right_inv j := by cases j; repeat rfl
#align category_theory.limits.walking_pair.swap CategoryTheory.Limits.WalkingPair.swap
@[simp]
theorem WalkingPair.swap_apply_left : WalkingPair.swap left = right :=
rfl
#align category_theory.limits.walking_pair.swap_apply_left CategoryTheory.Limits.WalkingPair.swap_apply_left
@[simp]
theorem WalkingPair.swap_apply_right : WalkingPair.swap right = left :=
rfl
#align category_theory.limits.walking_pair.swap_apply_right CategoryTheory.Limits.WalkingPair.swap_apply_right
@[simp]
theorem WalkingPair.swap_symm_apply_tt : WalkingPair.swap.symm left = right :=
rfl
#align category_theory.limits.walking_pair.swap_symm_apply_tt CategoryTheory.Limits.WalkingPair.swap_symm_apply_tt
@[simp]
theorem WalkingPair.swap_symm_apply_ff : WalkingPair.swap.symm right = left :=
rfl
#align category_theory.limits.walking_pair.swap_symm_apply_ff CategoryTheory.Limits.WalkingPair.swap_symm_apply_ff
def WalkingPair.equivBool : WalkingPair ≃ Bool where
toFun j := WalkingPair.recOn j true false
-- to match equiv.sum_equiv_sigma_bool
invFun b := Bool.recOn b right left
left_inv j := by cases j; repeat rfl
right_inv b := by cases b; repeat rfl
#align category_theory.limits.walking_pair.equiv_bool CategoryTheory.Limits.WalkingPair.equivBool
@[simp]
theorem WalkingPair.equivBool_apply_left : WalkingPair.equivBool left = true :=
rfl
#align category_theory.limits.walking_pair.equiv_bool_apply_left CategoryTheory.Limits.WalkingPair.equivBool_apply_left
@[simp]
theorem WalkingPair.equivBool_apply_right : WalkingPair.equivBool right = false :=
rfl
#align category_theory.limits.walking_pair.equiv_bool_apply_right CategoryTheory.Limits.WalkingPair.equivBool_apply_right
@[simp]
theorem WalkingPair.equivBool_symm_apply_true : WalkingPair.equivBool.symm true = left :=
rfl
#align category_theory.limits.walking_pair.equiv_bool_symm_apply_tt CategoryTheory.Limits.WalkingPair.equivBool_symm_apply_true
@[simp]
theorem WalkingPair.equivBool_symm_apply_false : WalkingPair.equivBool.symm false = right :=
rfl
#align category_theory.limits.walking_pair.equiv_bool_symm_apply_ff CategoryTheory.Limits.WalkingPair.equivBool_symm_apply_false
variable {C : Type u}
def pairFunction (X Y : C) : WalkingPair → C := fun j => WalkingPair.casesOn j X Y
#align category_theory.limits.pair_function CategoryTheory.Limits.pairFunction
@[simp]
theorem pairFunction_left (X Y : C) : pairFunction X Y left = X :=
rfl
#align category_theory.limits.pair_function_left CategoryTheory.Limits.pairFunction_left
@[simp]
theorem pairFunction_right (X Y : C) : pairFunction X Y right = Y :=
rfl
#align category_theory.limits.pair_function_right CategoryTheory.Limits.pairFunction_right
variable [Category.{v} C]
def pair (X Y : C) : Discrete WalkingPair ⥤ C :=
Discrete.functor fun j => WalkingPair.casesOn j X Y
#align category_theory.limits.pair CategoryTheory.Limits.pair
@[simp]
theorem pair_obj_left (X Y : C) : (pair X Y).obj ⟨left⟩ = X :=
rfl
#align category_theory.limits.pair_obj_left CategoryTheory.Limits.pair_obj_left
@[simp]
theorem pair_obj_right (X Y : C) : (pair X Y).obj ⟨right⟩ = Y :=
rfl
#align category_theory.limits.pair_obj_right CategoryTheory.Limits.pair_obj_right
section
variable {F G : Discrete WalkingPair ⥤ C} (f : F.obj ⟨left⟩ ⟶ G.obj ⟨left⟩)
(g : F.obj ⟨right⟩ ⟶ G.obj ⟨right⟩)
attribute [local aesop safe tactic (rule_sets := [CategoryTheory])]
CategoryTheory.Discrete.discreteCases
def mapPair : F ⟶ G where
app j := Discrete.recOn j fun j => WalkingPair.casesOn j f g
naturality := fun ⟨X⟩ ⟨Y⟩ ⟨⟨u⟩⟩ => by aesop_cat
#align category_theory.limits.map_pair CategoryTheory.Limits.mapPair
@[simp]
theorem mapPair_left : (mapPair f g).app ⟨left⟩ = f :=
rfl
#align category_theory.limits.map_pair_left CategoryTheory.Limits.mapPair_left
@[simp]
theorem mapPair_right : (mapPair f g).app ⟨right⟩ = g :=
rfl
#align category_theory.limits.map_pair_right CategoryTheory.Limits.mapPair_right
@[simps!]
def mapPairIso (f : F.obj ⟨left⟩ ≅ G.obj ⟨left⟩) (g : F.obj ⟨right⟩ ≅ G.obj ⟨right⟩) : F ≅ G :=
NatIso.ofComponents (fun j => Discrete.recOn j fun j => WalkingPair.casesOn j f g)
(fun ⟨⟨u⟩⟩ => by aesop_cat)
#align category_theory.limits.map_pair_iso CategoryTheory.Limits.mapPairIso
end
@[simps!]
def diagramIsoPair (F : Discrete WalkingPair ⥤ C) :
F ≅ pair (F.obj ⟨WalkingPair.left⟩) (F.obj ⟨WalkingPair.right⟩) :=
mapPairIso (Iso.refl _) (Iso.refl _)
#align category_theory.limits.diagram_iso_pair CategoryTheory.Limits.diagramIsoPair
section
variable {D : Type u} [Category.{v} D]
def pairComp (X Y : C) (F : C ⥤ D) : pair X Y ⋙ F ≅ pair (F.obj X) (F.obj Y) :=
diagramIsoPair _
#align category_theory.limits.pair_comp CategoryTheory.Limits.pairComp
end
abbrev BinaryFan (X Y : C) :=
Cone (pair X Y)
#align category_theory.limits.binary_fan CategoryTheory.Limits.BinaryFan
abbrev BinaryFan.fst {X Y : C} (s : BinaryFan X Y) :=
s.π.app ⟨WalkingPair.left⟩
#align category_theory.limits.binary_fan.fst CategoryTheory.Limits.BinaryFan.fst
abbrev BinaryFan.snd {X Y : C} (s : BinaryFan X Y) :=
s.π.app ⟨WalkingPair.right⟩
#align category_theory.limits.binary_fan.snd CategoryTheory.Limits.BinaryFan.snd
@[simp]
theorem BinaryFan.π_app_left {X Y : C} (s : BinaryFan X Y) : s.π.app ⟨WalkingPair.left⟩ = s.fst :=
rfl
#align category_theory.limits.binary_fan.π_app_left CategoryTheory.Limits.BinaryFan.π_app_left
@[simp]
theorem BinaryFan.π_app_right {X Y : C} (s : BinaryFan X Y) : s.π.app ⟨WalkingPair.right⟩ = s.snd :=
rfl
#align category_theory.limits.binary_fan.π_app_right CategoryTheory.Limits.BinaryFan.π_app_right
def BinaryFan.IsLimit.mk {X Y : C} (s : BinaryFan X Y)
(lift : ∀ {T : C} (_ : T ⟶ X) (_ : T ⟶ Y), T ⟶ s.pt)
(hl₁ : ∀ {T : C} (f : T ⟶ X) (g : T ⟶ Y), lift f g ≫ s.fst = f)
(hl₂ : ∀ {T : C} (f : T ⟶ X) (g : T ⟶ Y), lift f g ≫ s.snd = g)
(uniq :
∀ {T : C} (f : T ⟶ X) (g : T ⟶ Y) (m : T ⟶ s.pt) (_ : m ≫ s.fst = f) (_ : m ≫ s.snd = g),
m = lift f g) :
IsLimit s :=
Limits.IsLimit.mk (fun t => lift (BinaryFan.fst t) (BinaryFan.snd t))
(by
rintro t (rfl | rfl)
· exact hl₁ _ _
· exact hl₂ _ _)
fun t m h => uniq _ _ _ (h ⟨WalkingPair.left⟩) (h ⟨WalkingPair.right⟩)
#align category_theory.limits.binary_fan.is_limit.mk CategoryTheory.Limits.BinaryFan.IsLimit.mk
theorem BinaryFan.IsLimit.hom_ext {W X Y : C} {s : BinaryFan X Y} (h : IsLimit s) {f g : W ⟶ s.pt}
(h₁ : f ≫ s.fst = g ≫ s.fst) (h₂ : f ≫ s.snd = g ≫ s.snd) : f = g :=
h.hom_ext fun j => Discrete.recOn j fun j => WalkingPair.casesOn j h₁ h₂
#align category_theory.limits.binary_fan.is_limit.hom_ext CategoryTheory.Limits.BinaryFan.IsLimit.hom_ext
abbrev BinaryCofan (X Y : C) := Cocone (pair X Y)
#align category_theory.limits.binary_cofan CategoryTheory.Limits.BinaryCofan
abbrev BinaryCofan.inl {X Y : C} (s : BinaryCofan X Y) := s.ι.app ⟨WalkingPair.left⟩
#align category_theory.limits.binary_cofan.inl CategoryTheory.Limits.BinaryCofan.inl
abbrev BinaryCofan.inr {X Y : C} (s : BinaryCofan X Y) := s.ι.app ⟨WalkingPair.right⟩
#align category_theory.limits.binary_cofan.inr CategoryTheory.Limits.BinaryCofan.inr
@[simp]
theorem BinaryCofan.ι_app_left {X Y : C} (s : BinaryCofan X Y) :
s.ι.app ⟨WalkingPair.left⟩ = s.inl := rfl
#align category_theory.limits.binary_cofan.ι_app_left CategoryTheory.Limits.BinaryCofan.ι_app_left
@[simp]
theorem BinaryCofan.ι_app_right {X Y : C} (s : BinaryCofan X Y) :
s.ι.app ⟨WalkingPair.right⟩ = s.inr := rfl
#align category_theory.limits.binary_cofan.ι_app_right CategoryTheory.Limits.BinaryCofan.ι_app_right
def BinaryCofan.IsColimit.mk {X Y : C} (s : BinaryCofan X Y)
(desc : ∀ {T : C} (_ : X ⟶ T) (_ : Y ⟶ T), s.pt ⟶ T)
(hd₁ : ∀ {T : C} (f : X ⟶ T) (g : Y ⟶ T), s.inl ≫ desc f g = f)
(hd₂ : ∀ {T : C} (f : X ⟶ T) (g : Y ⟶ T), s.inr ≫ desc f g = g)
(uniq :
∀ {T : C} (f : X ⟶ T) (g : Y ⟶ T) (m : s.pt ⟶ T) (_ : s.inl ≫ m = f) (_ : s.inr ≫ m = g),
m = desc f g) :
IsColimit s :=
Limits.IsColimit.mk (fun t => desc (BinaryCofan.inl t) (BinaryCofan.inr t))
(by
rintro t (rfl | rfl)
· exact hd₁ _ _
· exact hd₂ _ _)
fun t m h => uniq _ _ _ (h ⟨WalkingPair.left⟩) (h ⟨WalkingPair.right⟩)
#align category_theory.limits.binary_cofan.is_colimit.mk CategoryTheory.Limits.BinaryCofan.IsColimit.mk
theorem BinaryCofan.IsColimit.hom_ext {W X Y : C} {s : BinaryCofan X Y} (h : IsColimit s)
{f g : s.pt ⟶ W} (h₁ : s.inl ≫ f = s.inl ≫ g) (h₂ : s.inr ≫ f = s.inr ≫ g) : f = g :=
h.hom_ext fun j => Discrete.recOn j fun j => WalkingPair.casesOn j h₁ h₂
#align category_theory.limits.binary_cofan.is_colimit.hom_ext CategoryTheory.Limits.BinaryCofan.IsColimit.hom_ext
variable {X Y : C}
section
attribute [local aesop safe tactic (rule_sets := [CategoryTheory])]
CategoryTheory.Discrete.discreteCases
-- Porting note: would it be okay to use this more generally?
attribute [local aesop safe cases (rule_sets := [CategoryTheory])] Eq
@[simps pt]
def BinaryFan.mk {P : C} (π₁ : P ⟶ X) (π₂ : P ⟶ Y) : BinaryFan X Y where
pt := P
π :=
{ app := fun ⟨j⟩ => by cases j <;> simpa }
#align category_theory.limits.binary_fan.mk CategoryTheory.Limits.BinaryFan.mk
@[simps pt]
def BinaryCofan.mk {P : C} (ι₁ : X ⟶ P) (ι₂ : Y ⟶ P) : BinaryCofan X Y where
pt := P
ι :=
{ app := fun ⟨j⟩ => by cases j <;> simpa }
#align category_theory.limits.binary_cofan.mk CategoryTheory.Limits.BinaryCofan.mk
end
@[simp]
theorem BinaryFan.mk_fst {P : C} (π₁ : P ⟶ X) (π₂ : P ⟶ Y) : (BinaryFan.mk π₁ π₂).fst = π₁ :=
rfl
#align category_theory.limits.binary_fan.mk_fst CategoryTheory.Limits.BinaryFan.mk_fst
@[simp]
theorem BinaryFan.mk_snd {P : C} (π₁ : P ⟶ X) (π₂ : P ⟶ Y) : (BinaryFan.mk π₁ π₂).snd = π₂ :=
rfl
#align category_theory.limits.binary_fan.mk_snd CategoryTheory.Limits.BinaryFan.mk_snd
@[simp]
theorem BinaryCofan.mk_inl {P : C} (ι₁ : X ⟶ P) (ι₂ : Y ⟶ P) : (BinaryCofan.mk ι₁ ι₂).inl = ι₁ :=
rfl
#align category_theory.limits.binary_cofan.mk_inl CategoryTheory.Limits.BinaryCofan.mk_inl
@[simp]
theorem BinaryCofan.mk_inr {P : C} (ι₁ : X ⟶ P) (ι₂ : Y ⟶ P) : (BinaryCofan.mk ι₁ ι₂).inr = ι₂ :=
rfl
#align category_theory.limits.binary_cofan.mk_inr CategoryTheory.Limits.BinaryCofan.mk_inr
def isoBinaryFanMk {X Y : C} (c : BinaryFan X Y) : c ≅ BinaryFan.mk c.fst c.snd :=
Cones.ext (Iso.refl _) fun j => by cases' j with l; cases l; repeat simp
#align category_theory.limits.iso_binary_fan_mk CategoryTheory.Limits.isoBinaryFanMk
def isoBinaryCofanMk {X Y : C} (c : BinaryCofan X Y) : c ≅ BinaryCofan.mk c.inl c.inr :=
Cocones.ext (Iso.refl _) fun j => by cases' j with l; cases l; repeat simp
#align category_theory.limits.iso_binary_cofan_mk CategoryTheory.Limits.isoBinaryCofanMk
def BinaryFan.isLimitMk {W : C} {fst : W ⟶ X} {snd : W ⟶ Y} (lift : ∀ s : BinaryFan X Y, s.pt ⟶ W)
(fac_left : ∀ s : BinaryFan X Y, lift s ≫ fst = s.fst)
(fac_right : ∀ s : BinaryFan X Y, lift s ≫ snd = s.snd)
(uniq :
∀ (s : BinaryFan X Y) (m : s.pt ⟶ W) (_ : m ≫ fst = s.fst) (_ : m ≫ snd = s.snd),
m = lift s) :
IsLimit (BinaryFan.mk fst snd) :=
{ lift := lift
fac := fun s j => by
rcases j with ⟨⟨⟩⟩
exacts [fac_left s, fac_right s]
uniq := fun s m w => uniq s m (w ⟨WalkingPair.left⟩) (w ⟨WalkingPair.right⟩) }
#align category_theory.limits.binary_fan.is_limit_mk CategoryTheory.Limits.BinaryFan.isLimitMk
def BinaryCofan.isColimitMk {W : C} {inl : X ⟶ W} {inr : Y ⟶ W}
(desc : ∀ s : BinaryCofan X Y, W ⟶ s.pt)
(fac_left : ∀ s : BinaryCofan X Y, inl ≫ desc s = s.inl)
(fac_right : ∀ s : BinaryCofan X Y, inr ≫ desc s = s.inr)
(uniq :
∀ (s : BinaryCofan X Y) (m : W ⟶ s.pt) (_ : inl ≫ m = s.inl) (_ : inr ≫ m = s.inr),
m = desc s) :
IsColimit (BinaryCofan.mk inl inr) :=
{ desc := desc
fac := fun s j => by
rcases j with ⟨⟨⟩⟩
exacts [fac_left s, fac_right s]
uniq := fun s m w => uniq s m (w ⟨WalkingPair.left⟩) (w ⟨WalkingPair.right⟩) }
#align category_theory.limits.binary_cofan.is_colimit_mk CategoryTheory.Limits.BinaryCofan.isColimitMk
@[simps]
def BinaryFan.IsLimit.lift' {W X Y : C} {s : BinaryFan X Y} (h : IsLimit s) (f : W ⟶ X)
(g : W ⟶ Y) : { l : W ⟶ s.pt // l ≫ s.fst = f ∧ l ≫ s.snd = g } :=
⟨h.lift <| BinaryFan.mk f g, h.fac _ _, h.fac _ _⟩
#align category_theory.limits.binary_fan.is_limit.lift' CategoryTheory.Limits.BinaryFan.IsLimit.lift'
@[simps]
def BinaryCofan.IsColimit.desc' {W X Y : C} {s : BinaryCofan X Y} (h : IsColimit s) (f : X ⟶ W)
(g : Y ⟶ W) : { l : s.pt ⟶ W // s.inl ≫ l = f ∧ s.inr ≫ l = g } :=
⟨h.desc <| BinaryCofan.mk f g, h.fac _ _, h.fac _ _⟩
#align category_theory.limits.binary_cofan.is_colimit.desc' CategoryTheory.Limits.BinaryCofan.IsColimit.desc'
def BinaryFan.isLimitFlip {X Y : C} {c : BinaryFan X Y} (hc : IsLimit c) :
IsLimit (BinaryFan.mk c.snd c.fst) :=
BinaryFan.isLimitMk (fun s => hc.lift (BinaryFan.mk s.snd s.fst)) (fun _ => hc.fac _ _)
(fun _ => hc.fac _ _) fun s _ e₁ e₂ =>
BinaryFan.IsLimit.hom_ext hc
(e₂.trans (hc.fac (BinaryFan.mk s.snd s.fst) ⟨WalkingPair.left⟩).symm)
(e₁.trans (hc.fac (BinaryFan.mk s.snd s.fst) ⟨WalkingPair.right⟩).symm)
#align category_theory.limits.binary_fan.is_limit_flip CategoryTheory.Limits.BinaryFan.isLimitFlip
theorem BinaryFan.isLimit_iff_isIso_fst {X Y : C} (h : IsTerminal Y) (c : BinaryFan X Y) :
Nonempty (IsLimit c) ↔ IsIso c.fst := by
constructor
· rintro ⟨H⟩
obtain ⟨l, hl, -⟩ := BinaryFan.IsLimit.lift' H (𝟙 X) (h.from X)
exact
⟨⟨l,
BinaryFan.IsLimit.hom_ext H (by simpa [hl, -Category.comp_id] using Category.comp_id _)
(h.hom_ext _ _),
hl⟩⟩
· intro
exact
⟨BinaryFan.IsLimit.mk _ (fun f _ => f ≫ inv c.fst) (fun _ _ => by simp)
(fun _ _ => h.hom_ext _ _) fun _ _ _ e _ => by simp [← e]⟩
#align category_theory.limits.binary_fan.is_limit_iff_is_iso_fst CategoryTheory.Limits.BinaryFan.isLimit_iff_isIso_fst
theorem BinaryFan.isLimit_iff_isIso_snd {X Y : C} (h : IsTerminal X) (c : BinaryFan X Y) :
Nonempty (IsLimit c) ↔ IsIso c.snd := by
refine Iff.trans ?_ (BinaryFan.isLimit_iff_isIso_fst h (BinaryFan.mk c.snd c.fst))
exact
⟨fun h => ⟨BinaryFan.isLimitFlip h.some⟩, fun h =>
⟨(BinaryFan.isLimitFlip h.some).ofIsoLimit (isoBinaryFanMk c).symm⟩⟩
#align category_theory.limits.binary_fan.is_limit_iff_is_iso_snd CategoryTheory.Limits.BinaryFan.isLimit_iff_isIso_snd
noncomputable def BinaryFan.isLimitCompLeftIso {X Y X' : C} (c : BinaryFan X Y) (f : X ⟶ X')
[IsIso f] (h : IsLimit c) : IsLimit (BinaryFan.mk (c.fst ≫ f) c.snd) := by
fapply BinaryFan.isLimitMk
· exact fun s => h.lift (BinaryFan.mk (s.fst ≫ inv f) s.snd)
· intro s -- Porting note: simp timed out here
simp only [Category.comp_id,BinaryFan.π_app_left,IsIso.inv_hom_id,
BinaryFan.mk_fst,IsLimit.fac_assoc,eq_self_iff_true,Category.assoc]
· intro s -- Porting note: simp timed out here
simp only [BinaryFan.π_app_right,BinaryFan.mk_snd,eq_self_iff_true,IsLimit.fac]
· intro s m e₁ e₂
-- Porting note: simpa timed out here also
apply BinaryFan.IsLimit.hom_ext h
· simpa only
[BinaryFan.π_app_left,BinaryFan.mk_fst,Category.assoc,IsLimit.fac,IsIso.eq_comp_inv]
· simpa only [BinaryFan.π_app_right,BinaryFan.mk_snd,IsLimit.fac]
#align category_theory.limits.binary_fan.is_limit_comp_left_iso CategoryTheory.Limits.BinaryFan.isLimitCompLeftIso
noncomputable def BinaryFan.isLimitCompRightIso {X Y Y' : C} (c : BinaryFan X Y) (f : Y ⟶ Y')
[IsIso f] (h : IsLimit c) : IsLimit (BinaryFan.mk c.fst (c.snd ≫ f)) :=
BinaryFan.isLimitFlip <| BinaryFan.isLimitCompLeftIso _ f (BinaryFan.isLimitFlip h)
#align category_theory.limits.binary_fan.is_limit_comp_right_iso CategoryTheory.Limits.BinaryFan.isLimitCompRightIso
def BinaryCofan.isColimitFlip {X Y : C} {c : BinaryCofan X Y} (hc : IsColimit c) :
IsColimit (BinaryCofan.mk c.inr c.inl) :=
BinaryCofan.isColimitMk (fun s => hc.desc (BinaryCofan.mk s.inr s.inl)) (fun _ => hc.fac _ _)
(fun _ => hc.fac _ _) fun s _ e₁ e₂ =>
BinaryCofan.IsColimit.hom_ext hc
(e₂.trans (hc.fac (BinaryCofan.mk s.inr s.inl) ⟨WalkingPair.left⟩).symm)
(e₁.trans (hc.fac (BinaryCofan.mk s.inr s.inl) ⟨WalkingPair.right⟩).symm)
#align category_theory.limits.binary_cofan.is_colimit_flip CategoryTheory.Limits.BinaryCofan.isColimitFlip
theorem BinaryCofan.isColimit_iff_isIso_inl {X Y : C} (h : IsInitial Y) (c : BinaryCofan X Y) :
Nonempty (IsColimit c) ↔ IsIso c.inl := by
constructor
· rintro ⟨H⟩
obtain ⟨l, hl, -⟩ := BinaryCofan.IsColimit.desc' H (𝟙 X) (h.to X)
refine ⟨⟨l, hl, BinaryCofan.IsColimit.hom_ext H (?_) (h.hom_ext _ _)⟩⟩
rw [Category.comp_id]
have e : (inl c ≫ l) ≫ inl c = 𝟙 X ≫ inl c := congrArg (·≫inl c) hl
rwa [Category.assoc,Category.id_comp] at e
· intro
exact
⟨BinaryCofan.IsColimit.mk _ (fun f _ => inv c.inl ≫ f)
(fun _ _ => IsIso.hom_inv_id_assoc _ _) (fun _ _ => h.hom_ext _ _) fun _ _ _ e _ =>
(IsIso.eq_inv_comp _).mpr e⟩
#align category_theory.limits.binary_cofan.is_colimit_iff_is_iso_inl CategoryTheory.Limits.BinaryCofan.isColimit_iff_isIso_inl
theorem BinaryCofan.isColimit_iff_isIso_inr {X Y : C} (h : IsInitial X) (c : BinaryCofan X Y) :
Nonempty (IsColimit c) ↔ IsIso c.inr := by
refine Iff.trans ?_ (BinaryCofan.isColimit_iff_isIso_inl h (BinaryCofan.mk c.inr c.inl))
exact
⟨fun h => ⟨BinaryCofan.isColimitFlip h.some⟩, fun h =>
⟨(BinaryCofan.isColimitFlip h.some).ofIsoColimit (isoBinaryCofanMk c).symm⟩⟩
#align category_theory.limits.binary_cofan.is_colimit_iff_is_iso_inr CategoryTheory.Limits.BinaryCofan.isColimit_iff_isIso_inr
noncomputable def BinaryCofan.isColimitCompLeftIso {X Y X' : C} (c : BinaryCofan X Y) (f : X' ⟶ X)
[IsIso f] (h : IsColimit c) : IsColimit (BinaryCofan.mk (f ≫ c.inl) c.inr) := by
fapply BinaryCofan.isColimitMk
· exact fun s => h.desc (BinaryCofan.mk (inv f ≫ s.inl) s.inr)
· intro s
-- Porting note: simp timed out here too
simp only [IsColimit.fac,BinaryCofan.ι_app_left,eq_self_iff_true,
Category.assoc,BinaryCofan.mk_inl,IsIso.hom_inv_id_assoc]
· intro s
-- Porting note: simp timed out here too
simp only [IsColimit.fac,BinaryCofan.ι_app_right,eq_self_iff_true,BinaryCofan.mk_inr]
· intro s m e₁ e₂
apply BinaryCofan.IsColimit.hom_ext h
· rw [← cancel_epi f]
-- Porting note: simp timed out here too
simpa only [IsColimit.fac,BinaryCofan.ι_app_left,eq_self_iff_true,
Category.assoc,BinaryCofan.mk_inl,IsIso.hom_inv_id_assoc] using e₁
-- Porting note: simp timed out here too
· simpa only [IsColimit.fac,BinaryCofan.ι_app_right,eq_self_iff_true,BinaryCofan.mk_inr]
#align category_theory.limits.binary_cofan.is_colimit_comp_left_iso CategoryTheory.Limits.BinaryCofan.isColimitCompLeftIso
noncomputable def BinaryCofan.isColimitCompRightIso {X Y Y' : C} (c : BinaryCofan X Y) (f : Y' ⟶ Y)
[IsIso f] (h : IsColimit c) : IsColimit (BinaryCofan.mk c.inl (f ≫ c.inr)) :=
BinaryCofan.isColimitFlip <| BinaryCofan.isColimitCompLeftIso _ f (BinaryCofan.isColimitFlip h)
#align category_theory.limits.binary_cofan.is_colimit_comp_right_iso CategoryTheory.Limits.BinaryCofan.isColimitCompRightIso
abbrev HasBinaryProduct (X Y : C) :=
HasLimit (pair X Y)
#align category_theory.limits.has_binary_product CategoryTheory.Limits.HasBinaryProduct
abbrev HasBinaryCoproduct (X Y : C) :=
HasColimit (pair X Y)
#align category_theory.limits.has_binary_coproduct CategoryTheory.Limits.HasBinaryCoproduct
abbrev prod (X Y : C) [HasBinaryProduct X Y] :=
limit (pair X Y)
#align category_theory.limits.prod CategoryTheory.Limits.prod
abbrev coprod (X Y : C) [HasBinaryCoproduct X Y] :=
colimit (pair X Y)
#align category_theory.limits.coprod CategoryTheory.Limits.coprod
notation:20 X " ⨯ " Y:20 => prod X Y
notation:20 X " ⨿ " Y:20 => coprod X Y
abbrev prod.fst {X Y : C} [HasBinaryProduct X Y] : X ⨯ Y ⟶ X :=
limit.π (pair X Y) ⟨WalkingPair.left⟩
#align category_theory.limits.prod.fst CategoryTheory.Limits.prod.fst
abbrev prod.snd {X Y : C} [HasBinaryProduct X Y] : X ⨯ Y ⟶ Y :=
limit.π (pair X Y) ⟨WalkingPair.right⟩
#align category_theory.limits.prod.snd CategoryTheory.Limits.prod.snd
abbrev coprod.inl {X Y : C} [HasBinaryCoproduct X Y] : X ⟶ X ⨿ Y :=
colimit.ι (pair X Y) ⟨WalkingPair.left⟩
#align category_theory.limits.coprod.inl CategoryTheory.Limits.coprod.inl
abbrev coprod.inr {X Y : C} [HasBinaryCoproduct X Y] : Y ⟶ X ⨿ Y :=
colimit.ι (pair X Y) ⟨WalkingPair.right⟩
#align category_theory.limits.coprod.inr CategoryTheory.Limits.coprod.inr
def prodIsProd (X Y : C) [HasBinaryProduct X Y] :
IsLimit (BinaryFan.mk (prod.fst : X ⨯ Y ⟶ X) prod.snd) :=
(limit.isLimit _).ofIsoLimit (Cones.ext (Iso.refl _) (fun ⟨u⟩ => by
cases u
· dsimp; simp only [Category.id_comp]; rfl
· dsimp; simp only [Category.id_comp]; rfl
))
#align category_theory.limits.prod_is_prod CategoryTheory.Limits.prodIsProd
def coprodIsCoprod (X Y : C) [HasBinaryCoproduct X Y] :
IsColimit (BinaryCofan.mk (coprod.inl : X ⟶ X ⨿ Y) coprod.inr) :=
(colimit.isColimit _).ofIsoColimit (Cocones.ext (Iso.refl _) (fun ⟨u⟩ => by
cases u
· dsimp; simp only [Category.comp_id]
· dsimp; simp only [Category.comp_id]
))
#align category_theory.limits.coprod_is_coprod CategoryTheory.Limits.coprodIsCoprod
@[ext 1100]
theorem prod.hom_ext {W X Y : C} [HasBinaryProduct X Y] {f g : W ⟶ X ⨯ Y}
(h₁ : f ≫ prod.fst = g ≫ prod.fst) (h₂ : f ≫ prod.snd = g ≫ prod.snd) : f = g :=
BinaryFan.IsLimit.hom_ext (limit.isLimit _) h₁ h₂
#align category_theory.limits.prod.hom_ext CategoryTheory.Limits.prod.hom_ext
@[ext 1100]
theorem coprod.hom_ext {W X Y : C} [HasBinaryCoproduct X Y] {f g : X ⨿ Y ⟶ W}
(h₁ : coprod.inl ≫ f = coprod.inl ≫ g) (h₂ : coprod.inr ≫ f = coprod.inr ≫ g) : f = g :=
BinaryCofan.IsColimit.hom_ext (colimit.isColimit _) h₁ h₂
#align category_theory.limits.coprod.hom_ext CategoryTheory.Limits.coprod.hom_ext
abbrev prod.lift {W X Y : C} [HasBinaryProduct X Y] (f : W ⟶ X) (g : W ⟶ Y) : W ⟶ X ⨯ Y :=
limit.lift _ (BinaryFan.mk f g)
#align category_theory.limits.prod.lift CategoryTheory.Limits.prod.lift
abbrev diag (X : C) [HasBinaryProduct X X] : X ⟶ X ⨯ X :=
prod.lift (𝟙 _) (𝟙 _)
#align category_theory.limits.diag CategoryTheory.Limits.diag
abbrev coprod.desc {W X Y : C} [HasBinaryCoproduct X Y] (f : X ⟶ W) (g : Y ⟶ W) : X ⨿ Y ⟶ W :=
colimit.desc _ (BinaryCofan.mk f g)
#align category_theory.limits.coprod.desc CategoryTheory.Limits.coprod.desc
abbrev codiag (X : C) [HasBinaryCoproduct X X] : X ⨿ X ⟶ X :=
coprod.desc (𝟙 _) (𝟙 _)
#align category_theory.limits.codiag CategoryTheory.Limits.codiag
-- Porting note (#10618): simp removes as simp can prove this
@[reassoc]
theorem prod.lift_fst {W X Y : C} [HasBinaryProduct X Y] (f : W ⟶ X) (g : W ⟶ Y) :
prod.lift f g ≫ prod.fst = f :=
limit.lift_π _ _
#align category_theory.limits.prod.lift_fst CategoryTheory.Limits.prod.lift_fst
#align category_theory.limits.prod.lift_fst_assoc CategoryTheory.Limits.prod.lift_fst_assoc
-- Porting note (#10618): simp removes as simp can prove this
@[reassoc]
theorem prod.lift_snd {W X Y : C} [HasBinaryProduct X Y] (f : W ⟶ X) (g : W ⟶ Y) :
prod.lift f g ≫ prod.snd = g :=
limit.lift_π _ _
#align category_theory.limits.prod.lift_snd CategoryTheory.Limits.prod.lift_snd
#align category_theory.limits.prod.lift_snd_assoc CategoryTheory.Limits.prod.lift_snd_assoc
-- The simp linter says simp can prove the reassoc version of this lemma.
-- Porting note: it can also prove the og version
@[reassoc]
theorem coprod.inl_desc {W X Y : C} [HasBinaryCoproduct X Y] (f : X ⟶ W) (g : Y ⟶ W) :
coprod.inl ≫ coprod.desc f g = f :=
colimit.ι_desc _ _
#align category_theory.limits.coprod.inl_desc CategoryTheory.Limits.coprod.inl_desc
#align category_theory.limits.coprod.inl_desc_assoc CategoryTheory.Limits.coprod.inl_desc_assoc
-- The simp linter says simp can prove the reassoc version of this lemma.
-- Porting note: it can also prove the og version
@[reassoc]
theorem coprod.inr_desc {W X Y : C} [HasBinaryCoproduct X Y] (f : X ⟶ W) (g : Y ⟶ W) :
coprod.inr ≫ coprod.desc f g = g :=
colimit.ι_desc _ _
#align category_theory.limits.coprod.inr_desc CategoryTheory.Limits.coprod.inr_desc
#align category_theory.limits.coprod.inr_desc_assoc CategoryTheory.Limits.coprod.inr_desc_assoc
instance prod.mono_lift_of_mono_left {W X Y : C} [HasBinaryProduct X Y] (f : W ⟶ X) (g : W ⟶ Y)
[Mono f] : Mono (prod.lift f g) :=
mono_of_mono_fac <| prod.lift_fst _ _
#align category_theory.limits.prod.mono_lift_of_mono_left CategoryTheory.Limits.prod.mono_lift_of_mono_left
instance prod.mono_lift_of_mono_right {W X Y : C} [HasBinaryProduct X Y] (f : W ⟶ X) (g : W ⟶ Y)
[Mono g] : Mono (prod.lift f g) :=
mono_of_mono_fac <| prod.lift_snd _ _
#align category_theory.limits.prod.mono_lift_of_mono_right CategoryTheory.Limits.prod.mono_lift_of_mono_right
instance coprod.epi_desc_of_epi_left {W X Y : C} [HasBinaryCoproduct X Y] (f : X ⟶ W) (g : Y ⟶ W)
[Epi f] : Epi (coprod.desc f g) :=
epi_of_epi_fac <| coprod.inl_desc _ _
#align category_theory.limits.coprod.epi_desc_of_epi_left CategoryTheory.Limits.coprod.epi_desc_of_epi_left
instance coprod.epi_desc_of_epi_right {W X Y : C} [HasBinaryCoproduct X Y] (f : X ⟶ W) (g : Y ⟶ W)
[Epi g] : Epi (coprod.desc f g) :=
epi_of_epi_fac <| coprod.inr_desc _ _
#align category_theory.limits.coprod.epi_desc_of_epi_right CategoryTheory.Limits.coprod.epi_desc_of_epi_right
def prod.lift' {W X Y : C} [HasBinaryProduct X Y] (f : W ⟶ X) (g : W ⟶ Y) :
{ l : W ⟶ X ⨯ Y // l ≫ prod.fst = f ∧ l ≫ prod.snd = g } :=
⟨prod.lift f g, prod.lift_fst _ _, prod.lift_snd _ _⟩
#align category_theory.limits.prod.lift' CategoryTheory.Limits.prod.lift'
def coprod.desc' {W X Y : C} [HasBinaryCoproduct X Y] (f : X ⟶ W) (g : Y ⟶ W) :
{ l : X ⨿ Y ⟶ W // coprod.inl ≫ l = f ∧ coprod.inr ≫ l = g } :=
⟨coprod.desc f g, coprod.inl_desc _ _, coprod.inr_desc _ _⟩
#align category_theory.limits.coprod.desc' CategoryTheory.Limits.coprod.desc'
def prod.map {W X Y Z : C} [HasBinaryProduct W X] [HasBinaryProduct Y Z] (f : W ⟶ Y) (g : X ⟶ Z) :
W ⨯ X ⟶ Y ⨯ Z :=
limMap (mapPair f g)
#align category_theory.limits.prod.map CategoryTheory.Limits.prod.map
def coprod.map {W X Y Z : C} [HasBinaryCoproduct W X] [HasBinaryCoproduct Y Z] (f : W ⟶ Y)
(g : X ⟶ Z) : W ⨿ X ⟶ Y ⨿ Z :=
colimMap (mapPair f g)
#align category_theory.limits.coprod.map CategoryTheory.Limits.coprod.map
section CoprodLemmas
-- @[reassoc (attr := simp)]
@[simp] -- Porting note: removing reassoc tag since result is not hygienic (two h's)
theorem coprod.desc_comp {V W X Y : C} [HasBinaryCoproduct X Y] (f : V ⟶ W) (g : X ⟶ V)
(h : Y ⟶ V) : coprod.desc g h ≫ f = coprod.desc (g ≫ f) (h ≫ f) := by
ext <;> simp
#align category_theory.limits.coprod.desc_comp CategoryTheory.Limits.coprod.desc_comp
-- Porting note: hand generated reassoc here. Simp can prove it
theorem coprod.desc_comp_assoc {C : Type u} [Category C] {V W X Y : C}
[HasBinaryCoproduct X Y] (f : V ⟶ W) (g : X ⟶ V) (h : Y ⟶ V) {Z : C} (l : W ⟶ Z) :
coprod.desc g h ≫ f ≫ l = coprod.desc (g ≫ f) (h ≫ f) ≫ l := by simp
#align category_theory.limits.coprod.desc_comp_assoc CategoryTheory.Limits.coprod.desc_comp
theorem coprod.diag_comp {X Y : C} [HasBinaryCoproduct X X] (f : X ⟶ Y) :
codiag X ≫ f = coprod.desc f f := by simp
#align category_theory.limits.coprod.diag_comp CategoryTheory.Limits.coprod.diag_comp
@[reassoc (attr := simp)]
theorem coprod.inl_map {W X Y Z : C} [HasBinaryCoproduct W X] [HasBinaryCoproduct Y Z] (f : W ⟶ Y)
(g : X ⟶ Z) : coprod.inl ≫ coprod.map f g = f ≫ coprod.inl :=
ι_colimMap _ _
#align category_theory.limits.coprod.inl_map CategoryTheory.Limits.coprod.inl_map
#align category_theory.limits.coprod.inl_map_assoc CategoryTheory.Limits.coprod.inl_map_assoc
@[reassoc (attr := simp)]
theorem coprod.inr_map {W X Y Z : C} [HasBinaryCoproduct W X] [HasBinaryCoproduct Y Z] (f : W ⟶ Y)
(g : X ⟶ Z) : coprod.inr ≫ coprod.map f g = g ≫ coprod.inr :=
ι_colimMap _ _
#align category_theory.limits.coprod.inr_map CategoryTheory.Limits.coprod.inr_map
#align category_theory.limits.coprod.inr_map_assoc CategoryTheory.Limits.coprod.inr_map_assoc
@[simp]
theorem coprod.map_id_id {X Y : C} [HasBinaryCoproduct X Y] : coprod.map (𝟙 X) (𝟙 Y) = 𝟙 _ := by
ext <;> simp
#align category_theory.limits.coprod.map_id_id CategoryTheory.Limits.coprod.map_id_id
@[simp]
theorem coprod.desc_inl_inr {X Y : C} [HasBinaryCoproduct X Y] :
coprod.desc coprod.inl coprod.inr = 𝟙 (X ⨿ Y) := by ext <;> simp
#align category_theory.limits.coprod.desc_inl_inr CategoryTheory.Limits.coprod.desc_inl_inr
-- The simp linter says simp can prove the reassoc version of this lemma.
@[reassoc, simp]
theorem coprod.map_desc {S T U V W : C} [HasBinaryCoproduct U W] [HasBinaryCoproduct T V]
(f : U ⟶ S) (g : W ⟶ S) (h : T ⟶ U) (k : V ⟶ W) :
coprod.map h k ≫ coprod.desc f g = coprod.desc (h ≫ f) (k ≫ g) := by
ext <;> simp
#align category_theory.limits.coprod.map_desc CategoryTheory.Limits.coprod.map_desc
#align category_theory.limits.coprod.map_desc_assoc CategoryTheory.Limits.coprod.map_desc_assoc
@[simp]
theorem coprod.desc_comp_inl_comp_inr {W X Y Z : C} [HasBinaryCoproduct W Y]
[HasBinaryCoproduct X Z] (g : W ⟶ X) (g' : Y ⟶ Z) :
coprod.desc (g ≫ coprod.inl) (g' ≫ coprod.inr) = coprod.map g g' := by
rw [← coprod.map_desc]; simp
#align category_theory.limits.coprod.desc_comp_inl_comp_inr CategoryTheory.Limits.coprod.desc_comp_inl_comp_inr
-- We take the right hand side here to be simp normal form, as this way composition lemmas for
-- `f ≫ h` and `g ≫ k` can fire (eg `id_comp`) , while `inl_map` and `inr_map` can still work just
-- as well.
@[reassoc (attr := simp)]
theorem coprod.map_map {A₁ A₂ A₃ B₁ B₂ B₃ : C} [HasBinaryCoproduct A₁ B₁] [HasBinaryCoproduct A₂ B₂]
[HasBinaryCoproduct A₃ B₃] (f : A₁ ⟶ A₂) (g : B₁ ⟶ B₂) (h : A₂ ⟶ A₃) (k : B₂ ⟶ B₃) :
coprod.map f g ≫ coprod.map h k = coprod.map (f ≫ h) (g ≫ k) := by
ext <;> simp
#align category_theory.limits.coprod.map_map CategoryTheory.Limits.coprod.map_map
#align category_theory.limits.coprod.map_map_assoc CategoryTheory.Limits.coprod.map_map_assoc
-- I don't think it's a good idea to make any of the following three simp lemmas.
@[reassoc]
theorem coprod.map_swap {A B X Y : C} (f : A ⟶ B) (g : X ⟶ Y)
[HasColimitsOfShape (Discrete WalkingPair) C] :
coprod.map (𝟙 X) f ≫ coprod.map g (𝟙 B) = coprod.map g (𝟙 A) ≫ coprod.map (𝟙 Y) f := by simp
#align category_theory.limits.coprod.map_swap CategoryTheory.Limits.coprod.map_swap
#align category_theory.limits.coprod.map_swap_assoc CategoryTheory.Limits.coprod.map_swap_assoc
@[reassoc]
theorem coprod.map_comp_id {X Y Z W : C} (f : X ⟶ Y) (g : Y ⟶ Z) [HasBinaryCoproduct Z W]
[HasBinaryCoproduct Y W] [HasBinaryCoproduct X W] :
coprod.map (f ≫ g) (𝟙 W) = coprod.map f (𝟙 W) ≫ coprod.map g (𝟙 W) := by simp
#align category_theory.limits.coprod.map_comp_id CategoryTheory.Limits.coprod.map_comp_id
#align category_theory.limits.coprod.map_comp_id_assoc CategoryTheory.Limits.coprod.map_comp_id_assoc
@[reassoc]
theorem coprod.map_id_comp {X Y Z W : C} (f : X ⟶ Y) (g : Y ⟶ Z) [HasBinaryCoproduct W X]
[HasBinaryCoproduct W Y] [HasBinaryCoproduct W Z] :
coprod.map (𝟙 W) (f ≫ g) = coprod.map (𝟙 W) f ≫ coprod.map (𝟙 W) g := by simp
#align category_theory.limits.coprod.map_id_comp CategoryTheory.Limits.coprod.map_id_comp
#align category_theory.limits.coprod.map_id_comp_assoc CategoryTheory.Limits.coprod.map_id_comp_assoc
@[simps]
def coprod.mapIso {W X Y Z : C} [HasBinaryCoproduct W X] [HasBinaryCoproduct Y Z] (f : W ≅ Y)
(g : X ≅ Z) : W ⨿ X ≅ Y ⨿ Z where
hom := coprod.map f.hom g.hom
inv := coprod.map f.inv g.inv
#align category_theory.limits.coprod.map_iso CategoryTheory.Limits.coprod.mapIso
instance isIso_coprod {W X Y Z : C} [HasBinaryCoproduct W X] [HasBinaryCoproduct Y Z] (f : W ⟶ Y)
(g : X ⟶ Z) [IsIso f] [IsIso g] : IsIso (coprod.map f g) :=
(coprod.mapIso (asIso f) (asIso g)).isIso_hom
#align category_theory.limits.is_iso_coprod CategoryTheory.Limits.isIso_coprod
instance coprod.map_epi {C : Type*} [Category C] {W X Y Z : C} (f : W ⟶ Y) (g : X ⟶ Z) [Epi f]
[Epi g] [HasBinaryCoproduct W X] [HasBinaryCoproduct Y Z] : Epi (coprod.map f g) :=
⟨fun i₁ i₂ h => by
ext
· rw [← cancel_epi f]
simpa using congr_arg (fun f => coprod.inl ≫ f) h
· rw [← cancel_epi g]
simpa using congr_arg (fun f => coprod.inr ≫ f) h⟩
#align category_theory.limits.coprod.map_epi CategoryTheory.Limits.coprod.map_epi
-- The simp linter says simp can prove the reassoc version of this lemma.
-- Porting note: and the og version too
@[reassoc]
| Mathlib/CategoryTheory/Limits/Shapes/BinaryProducts.lean | 952 | 953 | theorem coprod.map_codiag {X Y : C} (f : X ⟶ Y) [HasBinaryCoproduct X X] [HasBinaryCoproduct Y Y] :
coprod.map f f ≫ codiag Y = codiag X ≫ f := by | simp
|
import Mathlib.Topology.CompactOpen
import Mathlib.Topology.Sets.Closeds
open Function Set Filter TopologicalSpace
open scoped Topology
variable {X Y : Type*} [TopologicalSpace X] [TopologicalSpace Y] [CompactSpace Y]
theorem TopologicalSpace.Clopens.exists_prod_subset (W : Clopens (X × Y)) {a : X × Y} (h : a ∈ W) :
∃ U : Clopens X, a.1 ∈ U ∧ ∃ V : Clopens Y, a.2 ∈ V ∧ U ×ˢ V ≤ W := by
have hp : Continuous (fun y : Y ↦ (a.1, y)) := Continuous.Prod.mk _
let V : Set Y := {y | (a.1, y) ∈ W}
have hV : IsCompact V := (W.2.1.preimage hp).isCompact
let U : Set X := {x | MapsTo (Prod.mk x) V W}
have hUV : U ×ˢ V ⊆ W := fun ⟨_, _⟩ hw ↦ hw.1 hw.2
exact ⟨⟨U, (ContinuousMap.isClopen_setOf_mapsTo hV W.2).preimage
(ContinuousMap.id (X × Y)).curry.2⟩, by simp [U, V, MapsTo], ⟨V, W.2.preimage hp⟩, h, hUV⟩
variable [CompactSpace X]
| Mathlib/Topology/ClopenBox.lean | 50 | 61 | theorem TopologicalSpace.Clopens.exists_finset_eq_sup_prod (W : Clopens (X × Y)) :
∃ (I : Finset (Clopens X × Clopens Y)), W = I.sup fun i ↦ i.1 ×ˢ i.2 := by |
choose! U hxU V hxV hUV using fun x ↦ W.exists_prod_subset (a := x)
rcases W.2.1.isCompact.elim_nhds_subcover (fun x ↦ U x ×ˢ V x) (fun x hx ↦
(U x ×ˢ V x).2.isOpen.mem_nhds ⟨hxU x hx, hxV x hx⟩) with ⟨I, hIW, hWI⟩
classical
use I.image fun x ↦ (U x, V x)
rw [Finset.sup_image]
refine le_antisymm (fun x hx ↦ ?_) (Finset.sup_le fun x hx ↦ ?_)
· rcases Set.mem_iUnion₂.1 (hWI hx) with ⟨i, hi, hxi⟩
exact SetLike.le_def.1 (Finset.le_sup hi) hxi
· exact hUV _ <| hIW _ hx
|
import Mathlib.Algebra.Order.Field.Power
import Mathlib.NumberTheory.Padics.PadicVal
#align_import number_theory.padics.padic_norm from "leanprover-community/mathlib"@"92ca63f0fb391a9ca5f22d2409a6080e786d99f7"
def padicNorm (p : ℕ) (q : ℚ) : ℚ :=
if q = 0 then 0 else (p : ℚ) ^ (-padicValRat p q)
#align padic_norm padicNorm
namespace padicNorm
open padicValRat
variable {p : ℕ}
@[simp]
protected theorem eq_zpow_of_nonzero {q : ℚ} (hq : q ≠ 0) :
padicNorm p q = (p : ℚ) ^ (-padicValRat p q) := by simp [hq, padicNorm]
#align padic_norm.eq_zpow_of_nonzero padicNorm.eq_zpow_of_nonzero
protected theorem nonneg (q : ℚ) : 0 ≤ padicNorm p q :=
if hq : q = 0 then by simp [hq, padicNorm]
else by
unfold padicNorm
split_ifs
apply zpow_nonneg
exact mod_cast Nat.zero_le _
#align padic_norm.nonneg padicNorm.nonneg
@[simp]
protected theorem zero : padicNorm p 0 = 0 := by simp [padicNorm]
#align padic_norm.zero padicNorm.zero
-- @[simp] -- Porting note (#10618): simp can prove this
protected theorem one : padicNorm p 1 = 1 := by simp [padicNorm]
#align padic_norm.one padicNorm.one
theorem padicNorm_p (hp : 1 < p) : padicNorm p p = (p : ℚ)⁻¹ := by
simp [padicNorm, (pos_of_gt hp).ne', padicValNat.self hp]
#align padic_norm.padic_norm_p padicNorm.padicNorm_p
@[simp]
theorem padicNorm_p_of_prime [Fact p.Prime] : padicNorm p p = (p : ℚ)⁻¹ :=
padicNorm_p <| Nat.Prime.one_lt Fact.out
#align padic_norm.padic_norm_p_of_prime padicNorm.padicNorm_p_of_prime
theorem padicNorm_of_prime_of_ne {q : ℕ} [p_prime : Fact p.Prime] [q_prime : Fact q.Prime]
(neq : p ≠ q) : padicNorm p q = 1 := by
have p : padicValRat p q = 0 := mod_cast padicValNat_primes neq
rw [padicNorm, p]
simp [q_prime.1.ne_zero]
#align padic_norm.padic_norm_of_prime_of_ne padicNorm.padicNorm_of_prime_of_ne
theorem padicNorm_p_lt_one (hp : 1 < p) : padicNorm p p < 1 := by
rw [padicNorm_p hp, inv_lt_one_iff]
exact mod_cast Or.inr hp
#align padic_norm.padic_norm_p_lt_one padicNorm.padicNorm_p_lt_one
theorem padicNorm_p_lt_one_of_prime [Fact p.Prime] : padicNorm p p < 1 :=
padicNorm_p_lt_one <| Nat.Prime.one_lt Fact.out
#align padic_norm.padic_norm_p_lt_one_of_prime padicNorm.padicNorm_p_lt_one_of_prime
protected theorem values_discrete {q : ℚ} (hq : q ≠ 0) : ∃ z : ℤ, padicNorm p q = (p : ℚ) ^ (-z) :=
⟨padicValRat p q, by simp [padicNorm, hq]⟩
#align padic_norm.values_discrete padicNorm.values_discrete
@[simp]
protected theorem neg (q : ℚ) : padicNorm p (-q) = padicNorm p q :=
if hq : q = 0 then by simp [hq] else by simp [padicNorm, hq]
#align padic_norm.neg padicNorm.neg
variable [hp : Fact p.Prime]
protected theorem nonzero {q : ℚ} (hq : q ≠ 0) : padicNorm p q ≠ 0 := by
rw [padicNorm.eq_zpow_of_nonzero hq]
apply zpow_ne_zero
exact mod_cast ne_of_gt hp.1.pos
#align padic_norm.nonzero padicNorm.nonzero
theorem zero_of_padicNorm_eq_zero {q : ℚ} (h : padicNorm p q = 0) : q = 0 := by
apply by_contradiction; intro hq
unfold padicNorm at h; rw [if_neg hq] at h
apply absurd h
apply zpow_ne_zero
exact mod_cast hp.1.ne_zero
#align padic_norm.zero_of_padic_norm_eq_zero padicNorm.zero_of_padicNorm_eq_zero
@[simp]
protected theorem mul (q r : ℚ) : padicNorm p (q * r) = padicNorm p q * padicNorm p r :=
if hq : q = 0 then by simp [hq]
else
if hr : r = 0 then by simp [hr]
else by
have : (p : ℚ) ≠ 0 := by simp [hp.1.ne_zero]
simp [padicNorm, *, padicValRat.mul, zpow_add₀ this, mul_comm]
#align padic_norm.mul padicNorm.mul
@[simp]
protected theorem div (q r : ℚ) : padicNorm p (q / r) = padicNorm p q / padicNorm p r :=
if hr : r = 0 then by simp [hr]
else eq_div_of_mul_eq (padicNorm.nonzero hr) (by rw [← padicNorm.mul, div_mul_cancel₀ _ hr])
#align padic_norm.div padicNorm.div
protected theorem of_int (z : ℤ) : padicNorm p z ≤ 1 :=
if hz : z = 0 then by simp [hz, zero_le_one]
else by
unfold padicNorm
rw [if_neg _]
· refine zpow_le_one_of_nonpos ?_ ?_
· exact mod_cast le_of_lt hp.1.one_lt
· rw [padicValRat.of_int, neg_nonpos]
norm_cast
simp
exact mod_cast hz
#align padic_norm.of_int padicNorm.of_int
private theorem nonarchimedean_aux {q r : ℚ} (h : padicValRat p q ≤ padicValRat p r) :
padicNorm p (q + r) ≤ max (padicNorm p q) (padicNorm p r) :=
have hnqp : padicNorm p q ≥ 0 := padicNorm.nonneg _
have hnrp : padicNorm p r ≥ 0 := padicNorm.nonneg _
if hq : q = 0 then by simp [hq, max_eq_right hnrp, le_max_right]
else
if hr : r = 0 then by simp [hr, max_eq_left hnqp, le_max_left]
else
if hqr : q + r = 0 then le_trans (by simpa [hqr] using hnqp) (le_max_left _ _)
else by
unfold padicNorm; split_ifs
apply le_max_iff.2
left
apply zpow_le_of_le
· exact mod_cast le_of_lt hp.1.one_lt
· apply neg_le_neg
have : padicValRat p q = min (padicValRat p q) (padicValRat p r) := (min_eq_left h).symm
rw [this]
exact min_le_padicValRat_add hqr
protected theorem nonarchimedean {q r : ℚ} :
padicNorm p (q + r) ≤ max (padicNorm p q) (padicNorm p r) := by
wlog hle : padicValRat p q ≤ padicValRat p r generalizing q r
· rw [add_comm, max_comm]
exact this (le_of_not_le hle)
exact nonarchimedean_aux hle
#align padic_norm.nonarchimedean padicNorm.nonarchimedean
theorem triangle_ineq (q r : ℚ) : padicNorm p (q + r) ≤ padicNorm p q + padicNorm p r :=
calc
padicNorm p (q + r) ≤ max (padicNorm p q) (padicNorm p r) := padicNorm.nonarchimedean
_ ≤ padicNorm p q + padicNorm p r :=
max_le_add_of_nonneg (padicNorm.nonneg _) (padicNorm.nonneg _)
#align padic_norm.triangle_ineq padicNorm.triangle_ineq
protected theorem sub {q r : ℚ} : padicNorm p (q - r) ≤ max (padicNorm p q) (padicNorm p r) := by
rw [sub_eq_add_neg, ← padicNorm.neg r]
exact padicNorm.nonarchimedean
#align padic_norm.sub padicNorm.sub
theorem add_eq_max_of_ne {q r : ℚ} (hne : padicNorm p q ≠ padicNorm p r) :
padicNorm p (q + r) = max (padicNorm p q) (padicNorm p r) := by
wlog hlt : padicNorm p r < padicNorm p q
· rw [add_comm, max_comm]
exact this hne.symm (hne.lt_or_lt.resolve_right hlt)
have : padicNorm p q ≤ max (padicNorm p (q + r)) (padicNorm p r) :=
calc
padicNorm p q = padicNorm p (q + r + (-r)) := by ring_nf
_ ≤ max (padicNorm p (q + r)) (padicNorm p (-r)) := padicNorm.nonarchimedean
_ = max (padicNorm p (q + r)) (padicNorm p r) := by simp
have hnge : padicNorm p r ≤ padicNorm p (q + r) := by
apply le_of_not_gt
intro hgt
rw [max_eq_right_of_lt hgt] at this
exact not_lt_of_ge this hlt
have : padicNorm p q ≤ padicNorm p (q + r) := by rwa [max_eq_left hnge] at this
apply _root_.le_antisymm
· apply padicNorm.nonarchimedean
· rwa [max_eq_left_of_lt hlt]
#align padic_norm.add_eq_max_of_ne padicNorm.add_eq_max_of_ne
instance : IsAbsoluteValue (padicNorm p) where
abv_nonneg' := padicNorm.nonneg
abv_eq_zero' := ⟨zero_of_padicNorm_eq_zero, fun hx ↦ by simp [hx]⟩
abv_add' := padicNorm.triangle_ineq
abv_mul' := padicNorm.mul
theorem dvd_iff_norm_le {n : ℕ} {z : ℤ} : ↑(p ^ n) ∣ z ↔ padicNorm p z ≤ (p : ℚ) ^ (-n : ℤ) := by
unfold padicNorm; split_ifs with hz
· norm_cast at hz
simp [hz]
· rw [zpow_le_iff_le, neg_le_neg_iff, padicValRat.of_int,
padicValInt.of_ne_one_ne_zero hp.1.ne_one _]
· norm_cast
rw [← PartENat.coe_le_coe, PartENat.natCast_get, ← multiplicity.pow_dvd_iff_le_multiplicity,
Nat.cast_pow]
exact mod_cast hz
· exact mod_cast hp.1.one_lt
#align padic_norm.dvd_iff_norm_le padicNorm.dvd_iff_norm_le
| Mathlib/NumberTheory/Padics/PadicNorm.lean | 268 | 285 | theorem int_eq_one_iff (m : ℤ) : padicNorm p m = 1 ↔ ¬(p : ℤ) ∣ m := by |
nth_rw 2 [← pow_one p]
simp only [dvd_iff_norm_le, Int.cast_natCast, Nat.cast_one, zpow_neg, zpow_one, not_le]
constructor
· intro h
rw [h, inv_lt_one_iff_of_pos] <;> norm_cast
· exact Nat.Prime.one_lt Fact.out
· exact Nat.Prime.pos Fact.out
· simp only [padicNorm]
split_ifs
· rw [inv_lt_zero, ← Nat.cast_zero, Nat.cast_lt]
intro h
exact (Nat.not_lt_zero p h).elim
· have : 1 < (p : ℚ) := by norm_cast; exact Nat.Prime.one_lt (Fact.out : Nat.Prime p)
rw [← zpow_neg_one, zpow_lt_iff_lt this]
have : 0 ≤ padicValRat p m := by simp only [of_int, Nat.cast_nonneg]
intro h
rw [← zpow_zero (p : ℚ), zpow_inj] <;> linarith
|
import Mathlib.Data.W.Basic
#align_import data.pfunctor.univariate.basic from "leanprover-community/mathlib"@"8631e2d5ea77f6c13054d9151d82b83069680cb1"
-- "W", "Idx"
set_option linter.uppercaseLean3 false
universe u v v₁ v₂ v₃
@[pp_with_univ]
structure PFunctor where
A : Type u
B : A → Type u
#align pfunctor PFunctor
namespace PFunctor
instance : Inhabited PFunctor :=
⟨⟨default, default⟩⟩
variable (P : PFunctor.{u}) {α : Type v₁} {β : Type v₂} {γ : Type v₃}
@[coe]
def Obj (α : Type v) :=
Σ x : P.A, P.B x → α
#align pfunctor.obj PFunctor.Obj
instance : CoeFun PFunctor.{u} (fun _ => Type v → Type (max u v)) where
coe := Obj
def map (f : α → β) : P α → P β :=
fun ⟨a, g⟩ => ⟨a, f ∘ g⟩
#align pfunctor.map PFunctor.map
instance Obj.inhabited [Inhabited P.A] [Inhabited α] : Inhabited (P α) :=
⟨⟨default, default⟩⟩
#align pfunctor.obj.inhabited PFunctor.Obj.inhabited
instance : Functor.{v, max u v} P.Obj where map := @map P
@[simp]
theorem map_eq_map {α β : Type v} (f : α → β) (x : P α) : f <$> x = P.map f x :=
rfl
@[simp]
protected theorem map_eq (f : α → β) (a : P.A) (g : P.B a → α) :
P.map f ⟨a, g⟩ = ⟨a, f ∘ g⟩ :=
rfl
#align pfunctor.map_eq PFunctor.map_eq
@[simp]
protected theorem id_map : ∀ x : P α, P.map id x = x := fun ⟨_, _⟩ => rfl
#align pfunctor.id_map PFunctor.id_map
@[simp]
protected theorem map_map (f : α → β) (g : β → γ) :
∀ x : P α, P.map g (P.map f x) = P.map (g ∘ f) x := fun ⟨_, _⟩ => rfl
#align pfunctor.comp_map PFunctor.map_map
instance : LawfulFunctor.{v, max u v} P.Obj where
map_const := rfl
id_map x := P.id_map x
comp_map f g x := P.map_map f g x |>.symm
def W :=
WType P.B
#align pfunctor.W PFunctor.W
-- Porting note(#5171): this linter isn't ported yet.
-- attribute [nolint has_nonempty_instance] W
variable {P}
def W.head : W P → P.A
| ⟨a, _f⟩ => a
#align pfunctor.W.head PFunctor.W.head
def W.children : ∀ x : W P, P.B (W.head x) → W P
| ⟨_a, f⟩ => f
#align pfunctor.W.children PFunctor.W.children
def W.dest : W P → P (W P)
| ⟨a, f⟩ => ⟨a, f⟩
#align pfunctor.W.dest PFunctor.W.dest
def W.mk : P (W P) → W P
| ⟨a, f⟩ => ⟨a, f⟩
#align pfunctor.W.mk PFunctor.W.mk
@[simp]
| Mathlib/Data/PFunctor/Univariate/Basic.lean | 125 | 125 | theorem W.dest_mk (p : P (W P)) : W.dest (W.mk p) = p := by | cases p; rfl
|
import Mathlib.CategoryTheory.Monoidal.Category
import Mathlib.CategoryTheory.Adjunction.FullyFaithful
import Mathlib.CategoryTheory.Products.Basic
#align_import category_theory.monoidal.functor from "leanprover-community/mathlib"@"3d7987cda72abc473c7cdbbb075170e9ac620042"
open CategoryTheory
universe v₁ v₂ v₃ u₁ u₂ u₃
open CategoryTheory.Category
open CategoryTheory.Functor
namespace CategoryTheory
section
open MonoidalCategory
variable (C : Type u₁) [Category.{v₁} C] [MonoidalCategory.{v₁} C] (D : Type u₂) [Category.{v₂} D]
[MonoidalCategory.{v₂} D]
-- The direction of `left_unitality` and `right_unitality` as simp lemmas may look strange:
-- remember the rule of thumb that component indices of natural transformations
-- "weigh more" than structural maps.
-- (However by this argument `associativity` is currently stated backwards!)
structure LaxMonoidalFunctor extends C ⥤ D where
ε : 𝟙_ D ⟶ obj (𝟙_ C)
μ : ∀ X Y : C, obj X ⊗ obj Y ⟶ obj (X ⊗ Y)
μ_natural_left :
∀ {X Y : C} (f : X ⟶ Y) (X' : C),
map f ▷ obj X' ≫ μ Y X' = μ X X' ≫ map (f ▷ X') := by
aesop_cat
μ_natural_right :
∀ {X Y : C} (X' : C) (f : X ⟶ Y) ,
obj X' ◁ map f ≫ μ X' Y = μ X' X ≫ map (X' ◁ f) := by
aesop_cat
associativity :
∀ X Y Z : C,
μ X Y ▷ obj Z ≫ μ (X ⊗ Y) Z ≫ map (α_ X Y Z).hom =
(α_ (obj X) (obj Y) (obj Z)).hom ≫ obj X ◁ μ Y Z ≫ μ X (Y ⊗ Z) := by
aesop_cat
-- unitality
left_unitality : ∀ X : C, (λ_ (obj X)).hom = ε ▷ obj X ≫ μ (𝟙_ C) X ≫ map (λ_ X).hom := by
aesop_cat
right_unitality : ∀ X : C, (ρ_ (obj X)).hom = obj X ◁ ε ≫ μ X (𝟙_ C) ≫ map (ρ_ X).hom := by
aesop_cat
#align category_theory.lax_monoidal_functor CategoryTheory.LaxMonoidalFunctor
-- Porting note (#11215): TODO: remove this configuration and use the default configuration.
-- We keep this to be consistent with Lean 3.
-- See also `initialize_simps_projections MonoidalFunctor` below.
-- This may require waiting on https://github.com/leanprover-community/mathlib4/pull/2936
initialize_simps_projections LaxMonoidalFunctor (+toFunctor, -obj, -map)
attribute [reassoc (attr := simp)] LaxMonoidalFunctor.μ_natural_left
attribute [reassoc (attr := simp)] LaxMonoidalFunctor.μ_natural_right
attribute [simp] LaxMonoidalFunctor.left_unitality
attribute [simp] LaxMonoidalFunctor.right_unitality
attribute [reassoc (attr := simp)] LaxMonoidalFunctor.associativity
-- When `rewrite_search` lands, add @[search] attributes to
-- LaxMonoidalFunctor.μ_natural LaxMonoidalFunctor.left_unitality
-- LaxMonoidalFunctor.right_unitality LaxMonoidalFunctor.associativity
section
variable {C D}
@[reassoc (attr := simp)]
theorem LaxMonoidalFunctor.μ_natural (F : LaxMonoidalFunctor C D) {X Y X' Y' : C}
(f : X ⟶ Y) (g : X' ⟶ Y') :
(F.map f ⊗ F.map g) ≫ F.μ Y Y' = F.μ X X' ≫ F.map (f ⊗ g) := by
simp [tensorHom_def]
@[simps]
def LaxMonoidalFunctor.ofTensorHom (F : C ⥤ D)
(ε : 𝟙_ D ⟶ F.obj (𝟙_ C))
(μ : ∀ X Y : C, F.obj X ⊗ F.obj Y ⟶ F.obj (X ⊗ Y))
(μ_natural :
∀ {X Y X' Y' : C} (f : X ⟶ Y) (g : X' ⟶ Y'),
(F.map f ⊗ F.map g) ≫ μ Y Y' = μ X X' ≫ F.map (f ⊗ g) := by
aesop_cat)
(associativity :
∀ X Y Z : C,
(μ X Y ⊗ 𝟙 (F.obj Z)) ≫ μ (X ⊗ Y) Z ≫ F.map (α_ X Y Z).hom =
(α_ (F.obj X) (F.obj Y) (F.obj Z)).hom ≫ (𝟙 (F.obj X) ⊗ μ Y Z) ≫ μ X (Y ⊗ Z) := by
aesop_cat)
(left_unitality :
∀ X : C, (λ_ (F.obj X)).hom = (ε ⊗ 𝟙 (F.obj X)) ≫ μ (𝟙_ C) X ≫ F.map (λ_ X).hom := by
aesop_cat)
(right_unitality :
∀ X : C, (ρ_ (F.obj X)).hom = (𝟙 (F.obj X) ⊗ ε) ≫ μ X (𝟙_ C) ≫ F.map (ρ_ X).hom := by
aesop_cat) :
LaxMonoidalFunctor C D where
obj := F.obj
map := F.map
map_id := F.map_id
map_comp := F.map_comp
ε := ε
μ := μ
μ_natural_left := fun f X' => by
simp_rw [← tensorHom_id, ← F.map_id, μ_natural]
μ_natural_right := fun X' f => by
simp_rw [← id_tensorHom, ← F.map_id, μ_natural]
associativity := fun X Y Z => by
simp_rw [← tensorHom_id, ← id_tensorHom, associativity]
left_unitality := fun X => by
simp_rw [← tensorHom_id, left_unitality]
right_unitality := fun X => by
simp_rw [← id_tensorHom, right_unitality]
@[reassoc (attr := simp)]
theorem LaxMonoidalFunctor.left_unitality_inv (F : LaxMonoidalFunctor C D) (X : C) :
(λ_ (F.obj X)).inv ≫ F.ε ▷ F.obj X ≫ F.μ (𝟙_ C) X = F.map (λ_ X).inv := by
rw [Iso.inv_comp_eq, F.left_unitality, Category.assoc, Category.assoc, ← F.toFunctor.map_comp,
Iso.hom_inv_id, F.toFunctor.map_id, comp_id]
#align category_theory.lax_monoidal_functor.left_unitality_inv CategoryTheory.LaxMonoidalFunctor.left_unitality_inv
@[reassoc (attr := simp)]
theorem LaxMonoidalFunctor.right_unitality_inv (F : LaxMonoidalFunctor C D) (X : C) :
(ρ_ (F.obj X)).inv ≫ F.obj X ◁ F.ε ≫ F.μ X (𝟙_ C) = F.map (ρ_ X).inv := by
rw [Iso.inv_comp_eq, F.right_unitality, Category.assoc, Category.assoc, ← F.toFunctor.map_comp,
Iso.hom_inv_id, F.toFunctor.map_id, comp_id]
#align category_theory.lax_monoidal_functor.right_unitality_inv CategoryTheory.LaxMonoidalFunctor.right_unitality_inv
@[reassoc (attr := simp)]
theorem LaxMonoidalFunctor.associativity_inv (F : LaxMonoidalFunctor C D) (X Y Z : C) :
F.obj X ◁ F.μ Y Z ≫ F.μ X (Y ⊗ Z) ≫ F.map (α_ X Y Z).inv =
(α_ (F.obj X) (F.obj Y) (F.obj Z)).inv ≫ F.μ X Y ▷ F.obj Z ≫ F.μ (X ⊗ Y) Z := by
rw [Iso.eq_inv_comp, ← F.associativity_assoc, ← F.toFunctor.map_comp, Iso.hom_inv_id,
F.toFunctor.map_id, comp_id]
#align category_theory.lax_monoidal_functor.associativity_inv CategoryTheory.LaxMonoidalFunctor.associativity_inv
end
structure OplaxMonoidalFunctor extends C ⥤ D where
η : obj (𝟙_ C) ⟶ 𝟙_ D
δ : ∀ X Y : C, obj (X ⊗ Y) ⟶ obj X ⊗ obj Y
δ_natural_left :
∀ {X Y : C} (f : X ⟶ Y) (X' : C),
δ X X' ≫ map f ▷ obj X' = map (f ▷ X') ≫ δ Y X' := by
aesop_cat
δ_natural_right :
∀ {X Y : C} (X' : C) (f : X ⟶ Y) ,
δ X' X ≫ obj X' ◁ map f = map (X' ◁ f) ≫ δ X' Y := by
aesop_cat
associativity :
∀ X Y Z : C,
δ (X ⊗ Y) Z ≫ δ X Y ▷ obj Z ≫ (α_ (obj X) (obj Y) (obj Z)).hom =
map (α_ X Y Z).hom ≫ δ X (Y ⊗ Z) ≫ obj X ◁ δ Y Z := by
aesop_cat
-- unitality
left_unitality : ∀ X : C, (λ_ (obj X)).inv = map (λ_ X).inv ≫ δ (𝟙_ C) X ≫ η ▷ obj X := by
aesop_cat
right_unitality : ∀ X : C, (ρ_ (obj X)).inv = map (ρ_ X).inv ≫ δ X (𝟙_ C) ≫ obj X ◁ η := by
aesop_cat
initialize_simps_projections OplaxMonoidalFunctor (+toFunctor, -obj, -map)
attribute [reassoc (attr := simp)] OplaxMonoidalFunctor.δ_natural_left
attribute [reassoc (attr := simp)] OplaxMonoidalFunctor.δ_natural_right
attribute [simp] OplaxMonoidalFunctor.left_unitality
attribute [simp] OplaxMonoidalFunctor.right_unitality
attribute [reassoc (attr := simp)] OplaxMonoidalFunctor.associativity
section
variable {C D}
@[reassoc (attr := simp)]
theorem OplaxMonoidalFunctor.δ_natural (F : OplaxMonoidalFunctor C D) {X Y X' Y' : C}
(f : X ⟶ Y) (g : X' ⟶ Y') :
F.δ X X' ≫ (F.map f ⊗ F.map g) = F.map (f ⊗ g) ≫ F.δ Y Y' := by
simp [tensorHom_def]
@[reassoc (attr := simp)]
theorem OplaxMonoidalFunctor.left_unitality_hom (F : OplaxMonoidalFunctor C D) (X : C) :
F.δ (𝟙_ C) X ≫ F.η ▷ F.obj X ≫ (λ_ (F.obj X)).hom = F.map (λ_ X).hom := by
rw [← Category.assoc, ← Iso.eq_comp_inv, F.left_unitality, ← Category.assoc,
← F.toFunctor.map_comp, Iso.hom_inv_id, F.toFunctor.map_id, id_comp]
@[reassoc (attr := simp)]
theorem OplaxMonoidalFunctor.right_unitality_hom (F : OplaxMonoidalFunctor C D) (X : C) :
F.δ X (𝟙_ C) ≫ F.obj X ◁ F.η ≫ (ρ_ (F.obj X)).hom = F.map (ρ_ X).hom := by
rw [← Category.assoc, ← Iso.eq_comp_inv, F.right_unitality, ← Category.assoc,
← F.toFunctor.map_comp, Iso.hom_inv_id, F.toFunctor.map_id, id_comp]
@[reassoc (attr := simp)]
theorem OplaxMonoidalFunctor.associativity_inv (F : OplaxMonoidalFunctor C D) (X Y Z : C) :
F.δ X (Y ⊗ Z) ≫ F.obj X ◁ F.δ Y Z ≫ (α_ (F.obj X) (F.obj Y) (F.obj Z)).inv =
F.map (α_ X Y Z).inv ≫ F.δ (X ⊗ Y) Z ≫ F.δ X Y ▷ F.obj Z := by
rw [← Category.assoc, Iso.comp_inv_eq, Category.assoc, Category.assoc, F.associativity,
← Category.assoc, ← F.toFunctor.map_comp, Iso.inv_hom_id, F.toFunctor.map_id, id_comp]
end
structure MonoidalFunctor extends LaxMonoidalFunctor.{v₁, v₂} C D where
ε_isIso : IsIso ε := by infer_instance
μ_isIso : ∀ X Y : C, IsIso (μ X Y) := by infer_instance
#align category_theory.monoidal_functor CategoryTheory.MonoidalFunctor
-- See porting note on `initialize_simps_projections LaxMonoidalFunctor`
initialize_simps_projections MonoidalFunctor (+toLaxMonoidalFunctor, -obj, -map, -ε, -μ)
attribute [instance] MonoidalFunctor.ε_isIso MonoidalFunctor.μ_isIso
variable {C D}
noncomputable def MonoidalFunctor.εIso (F : MonoidalFunctor.{v₁, v₂} C D) :
𝟙_ D ≅ F.obj (𝟙_ C) :=
asIso F.ε
#align category_theory.monoidal_functor.ε_iso CategoryTheory.MonoidalFunctor.εIso
noncomputable def MonoidalFunctor.μIso (F : MonoidalFunctor.{v₁, v₂} C D) (X Y : C) :
F.obj X ⊗ F.obj Y ≅ F.obj (X ⊗ Y) :=
asIso (F.μ X Y)
#align category_theory.monoidal_functor.μ_iso CategoryTheory.MonoidalFunctor.μIso
@[simps]
noncomputable def MonoidalFunctor.toOplaxMonoidalFunctor (F : MonoidalFunctor C D) :
OplaxMonoidalFunctor C D :=
{ F with
η := inv F.ε,
δ := fun X Y => inv (F.μ X Y),
δ_natural_left := by aesop_cat
δ_natural_right := by aesop_cat
associativity := by
intros X Y Z
dsimp
rw [IsIso.inv_comp_eq, ← inv_whiskerRight, IsIso.inv_comp_eq]
slice_rhs 1 3 =>
rw [F.associativity]
simp
left_unitality := by
intros X
dsimp
apply Iso.inv_ext
rw [F.left_unitality]
slice_lhs 3 4 =>
rw [← F.map_comp, Iso.hom_inv_id, F.map_id]
simp [inv_whiskerRight]
right_unitality := by
intros X
dsimp
apply Iso.inv_ext
rw [F.right_unitality]
slice_lhs 3 4 =>
rw [← F.map_comp, Iso.hom_inv_id, F.map_id]
simp }
end
open MonoidalCategory
namespace LaxMonoidalFunctor
variable (F : LaxMonoidalFunctor.{v₁, v₂} C D) (G : LaxMonoidalFunctor.{v₁, v₃} C E)
def prod' : LaxMonoidalFunctor C (D × E) :=
(MonoidalFunctor.diag C).toLaxMonoidalFunctor ⊗⋙ F.prod G
#align category_theory.lax_monoidal_functor.prod' CategoryTheory.LaxMonoidalFunctor.prod'
@[simp]
theorem prod'_toFunctor : (F.prod' G).toFunctor = F.toFunctor.prod' G.toFunctor :=
rfl
#align category_theory.lax_monoidal_functor.prod'_to_functor CategoryTheory.LaxMonoidalFunctor.prod'_toFunctor
@[simp]
| Mathlib/CategoryTheory/Monoidal/Functor.lean | 591 | 593 | theorem prod'_ε : (F.prod' G).ε = (F.ε, G.ε) := by |
dsimp [prod']
simp
|
import Mathlib.Data.Bool.Basic
import Mathlib.Data.Option.Defs
import Mathlib.Data.Prod.Basic
import Mathlib.Data.Sigma.Basic
import Mathlib.Data.Subtype
import Mathlib.Data.Sum.Basic
import Mathlib.Init.Data.Sigma.Basic
import Mathlib.Logic.Equiv.Defs
import Mathlib.Logic.Function.Conjugate
import Mathlib.Tactic.Lift
import Mathlib.Tactic.Convert
import Mathlib.Tactic.Contrapose
import Mathlib.Tactic.GeneralizeProofs
import Mathlib.Tactic.SimpRw
#align_import logic.equiv.basic from "leanprover-community/mathlib"@"cd391184c85986113f8c00844cfe6dda1d34be3d"
set_option autoImplicit true
universe u
open Function
namespace Equiv
@[simps apply symm_apply]
def pprodEquivProd : PProd α β ≃ α × β where
toFun x := (x.1, x.2)
invFun x := ⟨x.1, x.2⟩
left_inv := fun _ => rfl
right_inv := fun _ => rfl
#align equiv.pprod_equiv_prod Equiv.pprodEquivProd
#align equiv.pprod_equiv_prod_apply Equiv.pprodEquivProd_apply
#align equiv.pprod_equiv_prod_symm_apply Equiv.pprodEquivProd_symm_apply
-- Porting note: in Lean 3 this had `@[congr]`
@[simps apply]
def pprodCongr (e₁ : α ≃ β) (e₂ : γ ≃ δ) : PProd α γ ≃ PProd β δ where
toFun x := ⟨e₁ x.1, e₂ x.2⟩
invFun x := ⟨e₁.symm x.1, e₂.symm x.2⟩
left_inv := fun ⟨x, y⟩ => by simp
right_inv := fun ⟨x, y⟩ => by simp
#align equiv.pprod_congr Equiv.pprodCongr
#align equiv.pprod_congr_apply Equiv.pprodCongr_apply
@[simps! apply symm_apply]
def pprodProd (ea : α₁ ≃ α₂) (eb : β₁ ≃ β₂) :
PProd α₁ β₁ ≃ α₂ × β₂ :=
(ea.pprodCongr eb).trans pprodEquivProd
#align equiv.pprod_prod Equiv.pprodProd
#align equiv.pprod_prod_apply Equiv.pprodProd_apply
#align equiv.pprod_prod_symm_apply Equiv.pprodProd_symm_apply
@[simps! apply symm_apply]
def prodPProd (ea : α₁ ≃ α₂) (eb : β₁ ≃ β₂) :
α₁ × β₁ ≃ PProd α₂ β₂ :=
(ea.symm.pprodProd eb.symm).symm
#align equiv.prod_pprod Equiv.prodPProd
#align equiv.prod_pprod_symm_apply Equiv.prodPProd_symm_apply
#align equiv.prod_pprod_apply Equiv.prodPProd_apply
@[simps! apply symm_apply]
def pprodEquivProdPLift : PProd α β ≃ PLift α × PLift β :=
Equiv.plift.symm.pprodProd Equiv.plift.symm
#align equiv.pprod_equiv_prod_plift Equiv.pprodEquivProdPLift
#align equiv.pprod_equiv_prod_plift_symm_apply Equiv.pprodEquivProdPLift_symm_apply
#align equiv.pprod_equiv_prod_plift_apply Equiv.pprodEquivProdPLift_apply
-- Porting note: in Lean 3 there was also a @[congr] tag
@[simps (config := .asFn) apply]
def prodCongr (e₁ : α₁ ≃ α₂) (e₂ : β₁ ≃ β₂) : α₁ × β₁ ≃ α₂ × β₂ :=
⟨Prod.map e₁ e₂, Prod.map e₁.symm e₂.symm, fun ⟨a, b⟩ => by simp, fun ⟨a, b⟩ => by simp⟩
#align equiv.prod_congr Equiv.prodCongr
#align equiv.prod_congr_apply Equiv.prodCongr_apply
@[simp]
theorem prodCongr_symm (e₁ : α₁ ≃ α₂) (e₂ : β₁ ≃ β₂) :
(prodCongr e₁ e₂).symm = prodCongr e₁.symm e₂.symm :=
rfl
#align equiv.prod_congr_symm Equiv.prodCongr_symm
def prodComm (α β) : α × β ≃ β × α :=
⟨Prod.swap, Prod.swap, Prod.swap_swap, Prod.swap_swap⟩
#align equiv.prod_comm Equiv.prodComm
@[simp]
theorem coe_prodComm (α β) : (⇑(prodComm α β) : α × β → β × α) = Prod.swap :=
rfl
#align equiv.coe_prod_comm Equiv.coe_prodComm
@[simp]
theorem prodComm_apply (x : α × β) : prodComm α β x = x.swap :=
rfl
#align equiv.prod_comm_apply Equiv.prodComm_apply
@[simp]
theorem prodComm_symm (α β) : (prodComm α β).symm = prodComm β α :=
rfl
#align equiv.prod_comm_symm Equiv.prodComm_symm
@[simps]
def prodAssoc (α β γ) : (α × β) × γ ≃ α × β × γ :=
⟨fun p => (p.1.1, p.1.2, p.2), fun p => ((p.1, p.2.1), p.2.2), fun ⟨⟨_, _⟩, _⟩ => rfl,
fun ⟨_, ⟨_, _⟩⟩ => rfl⟩
#align equiv.prod_assoc Equiv.prodAssoc
#align equiv.prod_assoc_symm_apply Equiv.prodAssoc_symm_apply
#align equiv.prod_assoc_apply Equiv.prodAssoc_apply
@[simps apply]
def prodProdProdComm (α β γ δ : Type*) : (α × β) × γ × δ ≃ (α × γ) × β × δ where
toFun abcd := ((abcd.1.1, abcd.2.1), (abcd.1.2, abcd.2.2))
invFun acbd := ((acbd.1.1, acbd.2.1), (acbd.1.2, acbd.2.2))
left_inv := fun ⟨⟨_a, _b⟩, ⟨_c, _d⟩⟩ => rfl
right_inv := fun ⟨⟨_a, _c⟩, ⟨_b, _d⟩⟩ => rfl
#align equiv.prod_prod_prod_comm Equiv.prodProdProdComm
@[simp]
theorem prodProdProdComm_symm (α β γ δ : Type*) :
(prodProdProdComm α β γ δ).symm = prodProdProdComm α γ β δ :=
rfl
#align equiv.prod_prod_prod_comm_symm Equiv.prodProdProdComm_symm
@[simps (config := .asFn)]
def curry (α β γ) : (α × β → γ) ≃ (α → β → γ) where
toFun := Function.curry
invFun := uncurry
left_inv := uncurry_curry
right_inv := curry_uncurry
#align equiv.curry Equiv.curry
#align equiv.curry_symm_apply Equiv.curry_symm_apply
#align equiv.curry_apply Equiv.curry_apply
section
@[simps]
def prodPUnit (α) : α × PUnit ≃ α :=
⟨fun p => p.1, fun a => (a, PUnit.unit), fun ⟨_, PUnit.unit⟩ => rfl, fun _ => rfl⟩
#align equiv.prod_punit Equiv.prodPUnit
#align equiv.prod_punit_apply Equiv.prodPUnit_apply
#align equiv.prod_punit_symm_apply Equiv.prodPUnit_symm_apply
@[simps!]
def punitProd (α) : PUnit × α ≃ α :=
calc
PUnit × α ≃ α × PUnit := prodComm _ _
_ ≃ α := prodPUnit _
#align equiv.punit_prod Equiv.punitProd
#align equiv.punit_prod_symm_apply Equiv.punitProd_symm_apply
#align equiv.punit_prod_apply Equiv.punitProd_apply
@[simps]
def sigmaPUnit (α) : (_ : α) × PUnit ≃ α :=
⟨fun p => p.1, fun a => ⟨a, PUnit.unit⟩, fun ⟨_, PUnit.unit⟩ => rfl, fun _ => rfl⟩
def prodUnique (α β) [Unique β] : α × β ≃ α :=
((Equiv.refl α).prodCongr <| equivPUnit.{_,1} β).trans <| prodPUnit α
#align equiv.prod_unique Equiv.prodUnique
@[simp]
theorem coe_prodUnique [Unique β] : (⇑(prodUnique α β) : α × β → α) = Prod.fst :=
rfl
#align equiv.coe_prod_unique Equiv.coe_prodUnique
theorem prodUnique_apply [Unique β] (x : α × β) : prodUnique α β x = x.1 :=
rfl
#align equiv.prod_unique_apply Equiv.prodUnique_apply
@[simp]
theorem prodUnique_symm_apply [Unique β] (x : α) :
(prodUnique α β).symm x = (x, default) :=
rfl
#align equiv.prod_unique_symm_apply Equiv.prodUnique_symm_apply
def uniqueProd (α β) [Unique β] : β × α ≃ α :=
((equivPUnit.{_,1} β).prodCongr <| Equiv.refl α).trans <| punitProd α
#align equiv.unique_prod Equiv.uniqueProd
@[simp]
theorem coe_uniqueProd [Unique β] : (⇑(uniqueProd α β) : β × α → α) = Prod.snd :=
rfl
#align equiv.coe_unique_prod Equiv.coe_uniqueProd
theorem uniqueProd_apply [Unique β] (x : β × α) : uniqueProd α β x = x.2 :=
rfl
#align equiv.unique_prod_apply Equiv.uniqueProd_apply
@[simp]
theorem uniqueProd_symm_apply [Unique β] (x : α) :
(uniqueProd α β).symm x = (default, x) :=
rfl
#align equiv.unique_prod_symm_apply Equiv.uniqueProd_symm_apply
def sigmaUnique (α) (β : α → Type*) [∀ a, Unique (β a)] : (a : α) × (β a) ≃ α :=
(Equiv.sigmaCongrRight fun a ↦ equivPUnit.{_,1} (β a)).trans <| sigmaPUnit α
@[simp]
theorem coe_sigmaUnique {β : α → Type*} [∀ a, Unique (β a)] :
(⇑(sigmaUnique α β) : (a : α) × (β a) → α) = Sigma.fst :=
rfl
theorem sigmaUnique_apply {β : α → Type*} [∀ a, Unique (β a)] (x : (a : α) × β a) :
sigmaUnique α β x = x.1 :=
rfl
@[simp]
theorem sigmaUnique_symm_apply {β : α → Type*} [∀ a, Unique (β a)] (x : α) :
(sigmaUnique α β).symm x = ⟨x, default⟩ :=
rfl
def prodEmpty (α) : α × Empty ≃ Empty :=
equivEmpty _
#align equiv.prod_empty Equiv.prodEmpty
def emptyProd (α) : Empty × α ≃ Empty :=
equivEmpty _
#align equiv.empty_prod Equiv.emptyProd
def prodPEmpty (α) : α × PEmpty ≃ PEmpty :=
equivPEmpty _
#align equiv.prod_pempty Equiv.prodPEmpty
def pemptyProd (α) : PEmpty × α ≃ PEmpty :=
equivPEmpty _
#align equiv.pempty_prod Equiv.pemptyProd
end
section
open Sum
def psumEquivSum (α β) : PSum α β ≃ Sum α β where
toFun s := PSum.casesOn s inl inr
invFun := Sum.elim PSum.inl PSum.inr
left_inv s := by cases s <;> rfl
right_inv s := by cases s <;> rfl
#align equiv.psum_equiv_sum Equiv.psumEquivSum
@[simps apply]
def sumCongr (ea : α₁ ≃ α₂) (eb : β₁ ≃ β₂) : Sum α₁ β₁ ≃ Sum α₂ β₂ :=
⟨Sum.map ea eb, Sum.map ea.symm eb.symm, fun x => by simp, fun x => by simp⟩
#align equiv.sum_congr Equiv.sumCongr
#align equiv.sum_congr_apply Equiv.sumCongr_apply
def psumCongr (e₁ : α ≃ β) (e₂ : γ ≃ δ) : PSum α γ ≃ PSum β δ where
toFun x := PSum.casesOn x (PSum.inl ∘ e₁) (PSum.inr ∘ e₂)
invFun x := PSum.casesOn x (PSum.inl ∘ e₁.symm) (PSum.inr ∘ e₂.symm)
left_inv := by rintro (x | x) <;> simp
right_inv := by rintro (x | x) <;> simp
#align equiv.psum_congr Equiv.psumCongr
def psumSum (ea : α₁ ≃ α₂) (eb : β₁ ≃ β₂) :
PSum α₁ β₁ ≃ Sum α₂ β₂ :=
(ea.psumCongr eb).trans (psumEquivSum _ _)
#align equiv.psum_sum Equiv.psumSum
def sumPSum (ea : α₁ ≃ α₂) (eb : β₁ ≃ β₂) :
Sum α₁ β₁ ≃ PSum α₂ β₂ :=
(ea.symm.psumSum eb.symm).symm
#align equiv.sum_psum Equiv.sumPSum
@[simp]
theorem sumCongr_trans (e : α₁ ≃ β₁) (f : α₂ ≃ β₂) (g : β₁ ≃ γ₁) (h : β₂ ≃ γ₂) :
(Equiv.sumCongr e f).trans (Equiv.sumCongr g h) = Equiv.sumCongr (e.trans g) (f.trans h) := by
ext i
cases i <;> rfl
#align equiv.sum_congr_trans Equiv.sumCongr_trans
@[simp]
theorem sumCongr_symm (e : α ≃ β) (f : γ ≃ δ) :
(Equiv.sumCongr e f).symm = Equiv.sumCongr e.symm f.symm :=
rfl
#align equiv.sum_congr_symm Equiv.sumCongr_symm
@[simp]
theorem sumCongr_refl : Equiv.sumCongr (Equiv.refl α) (Equiv.refl β) = Equiv.refl (Sum α β) := by
ext i
cases i <;> rfl
#align equiv.sum_congr_refl Equiv.sumCongr_refl
def subtypeSum {p : α ⊕ β → Prop} : {c // p c} ≃ {a // p (Sum.inl a)} ⊕ {b // p (Sum.inr b)} where
toFun c := match h : c.1 with
| Sum.inl a => Sum.inl ⟨a, h ▸ c.2⟩
| Sum.inr b => Sum.inr ⟨b, h ▸ c.2⟩
invFun c := match c with
| Sum.inl a => ⟨Sum.inl a, a.2⟩
| Sum.inr b => ⟨Sum.inr b, b.2⟩
left_inv := by rintro ⟨a | b, h⟩ <;> rfl
right_inv := by rintro (a | b) <;> rfl
def boolEquivPUnitSumPUnit : Bool ≃ Sum PUnit.{u + 1} PUnit.{v + 1} :=
⟨fun b => b.casesOn (inl PUnit.unit) (inr PUnit.unit) , Sum.elim (fun _ => false) fun _ => true,
fun b => by cases b <;> rfl, fun s => by rcases s with (⟨⟨⟩⟩ | ⟨⟨⟩⟩) <;> rfl⟩
#align equiv.bool_equiv_punit_sum_punit Equiv.boolEquivPUnitSumPUnit
@[simps (config := .asFn) apply]
def sumComm (α β) : Sum α β ≃ Sum β α :=
⟨Sum.swap, Sum.swap, Sum.swap_swap, Sum.swap_swap⟩
#align equiv.sum_comm Equiv.sumComm
#align equiv.sum_comm_apply Equiv.sumComm_apply
@[simp]
theorem sumComm_symm (α β) : (sumComm α β).symm = sumComm β α :=
rfl
#align equiv.sum_comm_symm Equiv.sumComm_symm
def sumAssoc (α β γ) : Sum (Sum α β) γ ≃ Sum α (Sum β γ) :=
⟨Sum.elim (Sum.elim Sum.inl (Sum.inr ∘ Sum.inl)) (Sum.inr ∘ Sum.inr),
Sum.elim (Sum.inl ∘ Sum.inl) <| Sum.elim (Sum.inl ∘ Sum.inr) Sum.inr,
by rintro (⟨_ | _⟩ | _) <;> rfl, by
rintro (_ | ⟨_ | _⟩) <;> rfl⟩
#align equiv.sum_assoc Equiv.sumAssoc
@[simp]
theorem sumAssoc_apply_inl_inl (a) : sumAssoc α β γ (inl (inl a)) = inl a :=
rfl
#align equiv.sum_assoc_apply_inl_inl Equiv.sumAssoc_apply_inl_inl
@[simp]
theorem sumAssoc_apply_inl_inr (b) : sumAssoc α β γ (inl (inr b)) = inr (inl b) :=
rfl
#align equiv.sum_assoc_apply_inl_inr Equiv.sumAssoc_apply_inl_inr
@[simp]
theorem sumAssoc_apply_inr (c) : sumAssoc α β γ (inr c) = inr (inr c) :=
rfl
#align equiv.sum_assoc_apply_inr Equiv.sumAssoc_apply_inr
@[simp]
theorem sumAssoc_symm_apply_inl {α β γ} (a) : (sumAssoc α β γ).symm (inl a) = inl (inl a) :=
rfl
#align equiv.sum_assoc_symm_apply_inl Equiv.sumAssoc_symm_apply_inl
@[simp]
theorem sumAssoc_symm_apply_inr_inl {α β γ} (b) :
(sumAssoc α β γ).symm (inr (inl b)) = inl (inr b) :=
rfl
#align equiv.sum_assoc_symm_apply_inr_inl Equiv.sumAssoc_symm_apply_inr_inl
@[simp]
theorem sumAssoc_symm_apply_inr_inr {α β γ} (c) : (sumAssoc α β γ).symm (inr (inr c)) = inr c :=
rfl
#align equiv.sum_assoc_symm_apply_inr_inr Equiv.sumAssoc_symm_apply_inr_inr
@[simps symm_apply]
def sumEmpty (α β) [IsEmpty β] : Sum α β ≃ α where
toFun := Sum.elim id isEmptyElim
invFun := inl
left_inv s := by
rcases s with (_ | x)
· rfl
· exact isEmptyElim x
right_inv _ := rfl
#align equiv.sum_empty Equiv.sumEmpty
#align equiv.sum_empty_symm_apply Equiv.sumEmpty_symm_apply
@[simp]
theorem sumEmpty_apply_inl [IsEmpty β] (a : α) : sumEmpty α β (Sum.inl a) = a :=
rfl
#align equiv.sum_empty_apply_inl Equiv.sumEmpty_apply_inl
@[simps! symm_apply]
def emptySum (α β) [IsEmpty α] : Sum α β ≃ β :=
(sumComm _ _).trans <| sumEmpty _ _
#align equiv.empty_sum Equiv.emptySum
#align equiv.empty_sum_symm_apply Equiv.emptySum_symm_apply
@[simp]
theorem emptySum_apply_inr [IsEmpty α] (b : β) : emptySum α β (Sum.inr b) = b :=
rfl
#align equiv.empty_sum_apply_inr Equiv.emptySum_apply_inr
def optionEquivSumPUnit (α) : Option α ≃ Sum α PUnit :=
⟨fun o => o.elim (inr PUnit.unit) inl, fun s => s.elim some fun _ => none,
fun o => by cases o <;> rfl,
fun s => by rcases s with (_ | ⟨⟨⟩⟩) <;> rfl⟩
#align equiv.option_equiv_sum_punit Equiv.optionEquivSumPUnit
@[simp]
theorem optionEquivSumPUnit_none : optionEquivSumPUnit α none = Sum.inr PUnit.unit :=
rfl
#align equiv.option_equiv_sum_punit_none Equiv.optionEquivSumPUnit_none
@[simp]
theorem optionEquivSumPUnit_some (a) : optionEquivSumPUnit α (some a) = Sum.inl a :=
rfl
#align equiv.option_equiv_sum_punit_some Equiv.optionEquivSumPUnit_some
@[simp]
theorem optionEquivSumPUnit_coe (a : α) : optionEquivSumPUnit α a = Sum.inl a :=
rfl
#align equiv.option_equiv_sum_punit_coe Equiv.optionEquivSumPUnit_coe
@[simp]
theorem optionEquivSumPUnit_symm_inl (a) : (optionEquivSumPUnit α).symm (Sum.inl a) = a :=
rfl
#align equiv.option_equiv_sum_punit_symm_inl Equiv.optionEquivSumPUnit_symm_inl
@[simp]
theorem optionEquivSumPUnit_symm_inr (a) : (optionEquivSumPUnit α).symm (Sum.inr a) = none :=
rfl
#align equiv.option_equiv_sum_punit_symm_inr Equiv.optionEquivSumPUnit_symm_inr
@[simps]
def optionIsSomeEquiv (α) : { x : Option α // x.isSome } ≃ α where
toFun o := Option.get _ o.2
invFun x := ⟨some x, rfl⟩
left_inv _ := Subtype.eq <| Option.some_get _
right_inv _ := Option.get_some _ _
#align equiv.option_is_some_equiv Equiv.optionIsSomeEquiv
#align equiv.option_is_some_equiv_apply Equiv.optionIsSomeEquiv_apply
#align equiv.option_is_some_equiv_symm_apply_coe Equiv.optionIsSomeEquiv_symm_apply_coe
@[simps]
def piOptionEquivProd {β : Option α → Type*} :
(∀ a : Option α, β a) ≃ β none × ∀ a : α, β (some a) where
toFun f := (f none, fun a => f (some a))
invFun x a := Option.casesOn a x.fst x.snd
left_inv f := funext fun a => by cases a <;> rfl
right_inv x := by simp
#align equiv.pi_option_equiv_prod Equiv.piOptionEquivProd
#align equiv.pi_option_equiv_prod_symm_apply Equiv.piOptionEquivProd_symm_apply
#align equiv.pi_option_equiv_prod_apply Equiv.piOptionEquivProd_apply
def sumEquivSigmaBool (α β : Type u) : Sum α β ≃ Σ b : Bool, b.casesOn α β :=
⟨fun s => s.elim (fun x => ⟨false, x⟩) fun x => ⟨true, x⟩, fun s =>
match s with
| ⟨false, a⟩ => inl a
| ⟨true, b⟩ => inr b,
fun s => by cases s <;> rfl, fun s => by rcases s with ⟨_ | _, _⟩ <;> rfl⟩
#align equiv.sum_equiv_sigma_bool Equiv.sumEquivSigmaBool
-- See also `Equiv.sigmaPreimageEquiv`.
@[simps]
def sigmaFiberEquiv {α β : Type*} (f : α → β) : (Σ y : β, { x // f x = y }) ≃ α :=
⟨fun x => ↑x.2, fun x => ⟨f x, x, rfl⟩, fun ⟨_, _, rfl⟩ => rfl, fun _ => rfl⟩
#align equiv.sigma_fiber_equiv Equiv.sigmaFiberEquiv
#align equiv.sigma_fiber_equiv_apply Equiv.sigmaFiberEquiv_apply
#align equiv.sigma_fiber_equiv_symm_apply_fst Equiv.sigmaFiberEquiv_symm_apply_fst
#align equiv.sigma_fiber_equiv_symm_apply_snd_coe Equiv.sigmaFiberEquiv_symm_apply_snd_coe
def sigmaEquivOptionOfInhabited (α : Type u) [Inhabited α] [DecidableEq α] :
Σ β : Type u, α ≃ Option β where
fst := {a // a ≠ default}
snd.toFun a := if h : a = default then none else some ⟨a, h⟩
snd.invFun := Option.elim' default (↑)
snd.left_inv a := by dsimp only; split_ifs <;> simp [*]
snd.right_inv
| none => by simp
| some ⟨a, ha⟩ => dif_neg ha
#align equiv.sigma_equiv_option_of_inhabited Equiv.sigmaEquivOptionOfInhabited
end
section
def piCongrRight {β₁ β₂ : α → Sort*} (F : ∀ a, β₁ a ≃ β₂ a) : (∀ a, β₁ a) ≃ (∀ a, β₂ a) :=
⟨fun H a => F a (H a), fun H a => (F a).symm (H a), fun H => funext <| by simp,
fun H => funext <| by simp⟩
#align equiv.Pi_congr_right Equiv.piCongrRight
@[simps apply]
def piComm (φ : α → β → Sort*) : (∀ a b, φ a b) ≃ ∀ b a, φ a b :=
⟨swap, swap, fun _ => rfl, fun _ => rfl⟩
#align equiv.Pi_comm Equiv.piComm
#align equiv.Pi_comm_apply Equiv.piComm_apply
@[simp]
theorem piComm_symm {φ : α → β → Sort*} : (piComm φ).symm = (piComm <| swap φ) :=
rfl
#align equiv.Pi_comm_symm Equiv.piComm_symm
def piCurry {β : α → Type*} (γ : ∀ a, β a → Type*) :
(∀ x : Σ i, β i, γ x.1 x.2) ≃ ∀ a b, γ a b where
toFun := Sigma.curry
invFun := Sigma.uncurry
left_inv := Sigma.uncurry_curry
right_inv := Sigma.curry_uncurry
#align equiv.Pi_curry Equiv.piCurry
-- `simps` overapplies these but `simps (config := .asFn)` under-applies them
@[simp] theorem piCurry_apply {β : α → Type*} (γ : ∀ a, β a → Type*)
(f : ∀ x : Σ i, β i, γ x.1 x.2) :
piCurry γ f = Sigma.curry f :=
rfl
@[simp] theorem piCurry_symm_apply {β : α → Type*} (γ : ∀ a, β a → Type*) (f : ∀ a b, γ a b) :
(piCurry γ).symm f = Sigma.uncurry f :=
rfl
end
namespace Perm
variable [DecidableEq α₁] (a : α₁) (e : Perm β₁)
def prodExtendRight : Perm (α₁ × β₁) where
toFun ab := if ab.fst = a then (a, e ab.snd) else ab
invFun ab := if ab.fst = a then (a, e.symm ab.snd) else ab
left_inv := by
rintro ⟨k', x⟩
dsimp only
split_ifs with h₁ h₂
· simp [h₁]
· simp at h₂
· simp
right_inv := by
rintro ⟨k', x⟩
dsimp only
split_ifs with h₁ h₂
· simp [h₁]
· simp at h₂
· simp
#align equiv.perm.prod_extend_right Equiv.Perm.prodExtendRight
@[simp]
theorem prodExtendRight_apply_eq (b : β₁) : prodExtendRight a e (a, b) = (a, e b) :=
if_pos rfl
#align equiv.perm.prod_extend_right_apply_eq Equiv.Perm.prodExtendRight_apply_eq
theorem prodExtendRight_apply_ne {a a' : α₁} (h : a' ≠ a) (b : β₁) :
prodExtendRight a e (a', b) = (a', b) :=
if_neg h
#align equiv.perm.prod_extend_right_apply_ne Equiv.Perm.prodExtendRight_apply_ne
| Mathlib/Logic/Equiv/Basic.lean | 916 | 919 | theorem eq_of_prodExtendRight_ne {e : Perm β₁} {a a' : α₁} {b : β₁}
(h : prodExtendRight a e (a', b) ≠ (a', b)) : a' = a := by |
contrapose! h
exact prodExtendRight_apply_ne _ h _
|
import Mathlib.Data.Part
import Mathlib.Data.Nat.Upto
import Mathlib.Data.Stream.Defs
import Mathlib.Tactic.Common
#align_import control.fix from "leanprover-community/mathlib"@"207cfac9fcd06138865b5d04f7091e46d9320432"
universe u v
open scoped Classical
variable {α : Type*} {β : α → Type*}
class Fix (α : Type*) where
fix : (α → α) → α
#align has_fix Fix
namespace Part
open Part Nat Nat.Upto
section Basic
variable (f : (∀ a, Part (β a)) → (∀ a, Part (β a)))
def Fix.approx : Stream' (∀ a, Part (β a))
| 0 => ⊥
| Nat.succ i => f (Fix.approx i)
#align part.fix.approx Part.Fix.approx
def fixAux {p : ℕ → Prop} (i : Nat.Upto p) (g : ∀ j : Nat.Upto p, i < j → ∀ a, Part (β a)) :
∀ a, Part (β a) :=
f fun x : α => (assert ¬p i.val) fun h : ¬p i.val => g (i.succ h) (Nat.lt_succ_self _) x
#align part.fix_aux Part.fixAux
protected def fix (x : α) : Part (β x) :=
(Part.assert (∃ i, (Fix.approx f i x).Dom)) fun h =>
WellFounded.fix.{1} (Nat.Upto.wf h) (fixAux f) Nat.Upto.zero x
#align part.fix Part.fix
protected theorem fix_def {x : α} (h' : ∃ i, (Fix.approx f i x).Dom) :
Part.fix f x = Fix.approx f (Nat.succ (Nat.find h')) x := by
let p := fun i : ℕ => (Fix.approx f i x).Dom
have : p (Nat.find h') := Nat.find_spec h'
generalize hk : Nat.find h' = k
replace hk : Nat.find h' = k + (@Upto.zero p).val := hk
rw [hk] at this
revert hk
dsimp [Part.fix]; rw [assert_pos h']; revert this
generalize Upto.zero = z; intro _this hk
suffices ∀ x',
WellFounded.fix (Part.fix.proof_1 f x h') (fixAux f) z x' = Fix.approx f (succ k) x'
from this _
induction k generalizing z with
| zero =>
intro x'
rw [Fix.approx, WellFounded.fix_eq, fixAux]
congr
ext x: 1
rw [assert_neg]
· rfl
· rw [Nat.zero_add] at _this
simpa only [not_not, Coe]
| succ n n_ih =>
intro x'
rw [Fix.approx, WellFounded.fix_eq, fixAux]
congr
ext : 1
have hh : ¬(Fix.approx f z.val x).Dom := by
apply Nat.find_min h'
rw [hk, Nat.succ_add_eq_add_succ]
apply Nat.lt_of_succ_le
apply Nat.le_add_left
rw [succ_add_eq_add_succ] at _this hk
rw [assert_pos hh, n_ih (Upto.succ z hh) _this hk]
#align part.fix_def Part.fix_def
| Mathlib/Control/Fix.lean | 111 | 113 | theorem fix_def' {x : α} (h' : ¬∃ i, (Fix.approx f i x).Dom) : Part.fix f x = none := by |
dsimp [Part.fix]
rw [assert_neg h']
|
import Mathlib.Order.Synonym
#align_import order.max from "leanprover-community/mathlib"@"6623e6af705e97002a9054c1c05a980180276fc1"
open OrderDual
universe u v
variable {α β : Type*}
class NoBotOrder (α : Type*) [LE α] : Prop where
exists_not_ge (a : α) : ∃ b, ¬a ≤ b
#align no_bot_order NoBotOrder
class NoTopOrder (α : Type*) [LE α] : Prop where
exists_not_le (a : α) : ∃ b, ¬b ≤ a
#align no_top_order NoTopOrder
class NoMinOrder (α : Type*) [LT α] : Prop where
exists_lt (a : α) : ∃ b, b < a
#align no_min_order NoMinOrder
class NoMaxOrder (α : Type*) [LT α] : Prop where
exists_gt (a : α) : ∃ b, a < b
#align no_max_order NoMaxOrder
export NoBotOrder (exists_not_ge)
export NoTopOrder (exists_not_le)
export NoMinOrder (exists_lt)
export NoMaxOrder (exists_gt)
instance nonempty_lt [LT α] [NoMinOrder α] (a : α) : Nonempty { x // x < a } :=
nonempty_subtype.2 (exists_lt a)
instance nonempty_gt [LT α] [NoMaxOrder α] (a : α) : Nonempty { x // a < x } :=
nonempty_subtype.2 (exists_gt a)
instance IsEmpty.toNoMaxOrder [LT α] [IsEmpty α] : NoMaxOrder α := ⟨isEmptyElim⟩
instance IsEmpty.toNoMinOrder [LT α] [IsEmpty α] : NoMinOrder α := ⟨isEmptyElim⟩
instance OrderDual.noBotOrder [LE α] [NoTopOrder α] : NoBotOrder αᵒᵈ :=
⟨fun a => exists_not_le (α := α) a⟩
#align order_dual.no_bot_order OrderDual.noBotOrder
instance OrderDual.noTopOrder [LE α] [NoBotOrder α] : NoTopOrder αᵒᵈ :=
⟨fun a => exists_not_ge (α := α) a⟩
#align order_dual.no_top_order OrderDual.noTopOrder
instance OrderDual.noMinOrder [LT α] [NoMaxOrder α] : NoMinOrder αᵒᵈ :=
⟨fun a => exists_gt (α := α) a⟩
#align order_dual.no_min_order OrderDual.noMinOrder
instance OrderDual.noMaxOrder [LT α] [NoMinOrder α] : NoMaxOrder αᵒᵈ :=
⟨fun a => exists_lt (α := α) a⟩
#align order_dual.no_max_order OrderDual.noMaxOrder
-- See note [lower instance priority]
instance (priority := 100) [Preorder α] [NoMinOrder α] : NoBotOrder α :=
⟨fun a => (exists_lt a).imp fun _ => not_le_of_lt⟩
-- See note [lower instance priority]
instance (priority := 100) [Preorder α] [NoMaxOrder α] : NoTopOrder α :=
⟨fun a => (exists_gt a).imp fun _ => not_le_of_lt⟩
instance noMaxOrder_of_left [Preorder α] [Preorder β] [NoMaxOrder α] : NoMaxOrder (α × β) :=
⟨fun ⟨a, b⟩ => by
obtain ⟨c, h⟩ := exists_gt a
exact ⟨(c, b), Prod.mk_lt_mk_iff_left.2 h⟩⟩
#align no_max_order_of_left noMaxOrder_of_left
instance noMaxOrder_of_right [Preorder α] [Preorder β] [NoMaxOrder β] : NoMaxOrder (α × β) :=
⟨fun ⟨a, b⟩ => by
obtain ⟨c, h⟩ := exists_gt b
exact ⟨(a, c), Prod.mk_lt_mk_iff_right.2 h⟩⟩
#align no_max_order_of_right noMaxOrder_of_right
instance noMinOrder_of_left [Preorder α] [Preorder β] [NoMinOrder α] : NoMinOrder (α × β) :=
⟨fun ⟨a, b⟩ => by
obtain ⟨c, h⟩ := exists_lt a
exact ⟨(c, b), Prod.mk_lt_mk_iff_left.2 h⟩⟩
#align no_min_order_of_left noMinOrder_of_left
instance noMinOrder_of_right [Preorder α] [Preorder β] [NoMinOrder β] : NoMinOrder (α × β) :=
⟨fun ⟨a, b⟩ => by
obtain ⟨c, h⟩ := exists_lt b
exact ⟨(a, c), Prod.mk_lt_mk_iff_right.2 h⟩⟩
#align no_min_order_of_right noMinOrder_of_right
instance {ι : Type u} {π : ι → Type*} [Nonempty ι] [∀ i, Preorder (π i)] [∀ i, NoMaxOrder (π i)] :
NoMaxOrder (∀ i, π i) :=
⟨fun a => by
classical
obtain ⟨b, hb⟩ := exists_gt (a <| Classical.arbitrary _)
exact ⟨_, lt_update_self_iff.2 hb⟩⟩
instance {ι : Type u} {π : ι → Type*} [Nonempty ι] [∀ i, Preorder (π i)] [∀ i, NoMinOrder (π i)] :
NoMinOrder (∀ i, π i) :=
⟨fun a => by
classical
obtain ⟨b, hb⟩ := exists_lt (a <| Classical.arbitrary _)
exact ⟨_, update_lt_self_iff.2 hb⟩⟩
-- Porting note: mathlib3 proof uses `convert`
theorem NoBotOrder.to_noMinOrder (α : Type*) [LinearOrder α] [NoBotOrder α] : NoMinOrder α :=
{ exists_lt := fun a => by simpa [not_le] using exists_not_ge a }
#align no_bot_order.to_no_min_order NoBotOrder.to_noMinOrder
-- Porting note: mathlib3 proof uses `convert`
theorem NoTopOrder.to_noMaxOrder (α : Type*) [LinearOrder α] [NoTopOrder α] : NoMaxOrder α :=
{ exists_gt := fun a => by simpa [not_le] using exists_not_le a }
#align no_top_order.to_no_max_order NoTopOrder.to_noMaxOrder
theorem noBotOrder_iff_noMinOrder (α : Type*) [LinearOrder α] : NoBotOrder α ↔ NoMinOrder α :=
⟨fun h =>
haveI := h
NoBotOrder.to_noMinOrder α,
fun h =>
haveI := h
inferInstance⟩
#align no_bot_order_iff_no_min_order noBotOrder_iff_noMinOrder
theorem noTopOrder_iff_noMaxOrder (α : Type*) [LinearOrder α] : NoTopOrder α ↔ NoMaxOrder α :=
⟨fun h =>
haveI := h
NoTopOrder.to_noMaxOrder α,
fun h =>
haveI := h
inferInstance⟩
#align no_top_order_iff_no_max_order noTopOrder_iff_noMaxOrder
theorem NoMinOrder.not_acc [LT α] [NoMinOrder α] (a : α) : ¬Acc (· < ·) a := fun h =>
Acc.recOn h fun x _ => (exists_lt x).recOn
#align no_min_order.not_acc NoMinOrder.not_acc
theorem NoMaxOrder.not_acc [LT α] [NoMaxOrder α] (a : α) : ¬Acc (· > ·) a := fun h =>
Acc.recOn h fun x _ => (exists_gt x).recOn
#align no_max_order.not_acc NoMaxOrder.not_acc
section Preorder
variable [Preorder α] {a b : α}
theorem IsBot.mono (ha : IsBot a) (h : b ≤ a) : IsBot b := fun _ => h.trans <| ha _
#align is_bot.mono IsBot.mono
theorem IsTop.mono (ha : IsTop a) (h : a ≤ b) : IsTop b := fun _ => (ha _).trans h
#align is_top.mono IsTop.mono
theorem IsMin.mono (ha : IsMin a) (h : b ≤ a) : IsMin b := fun _ hc => h.trans <| ha <| hc.trans h
#align is_min.mono IsMin.mono
theorem IsMax.mono (ha : IsMax a) (h : a ≤ b) : IsMax b := fun _ hc => (ha <| h.trans hc).trans h
#align is_max.mono IsMax.mono
theorem IsMin.not_lt (h : IsMin a) : ¬b < a := fun hb => hb.not_le <| h hb.le
#align is_min.not_lt IsMin.not_lt
theorem IsMax.not_lt (h : IsMax a) : ¬a < b := fun hb => hb.not_le <| h hb.le
#align is_max.not_lt IsMax.not_lt
@[simp]
theorem not_isMin_of_lt (h : b < a) : ¬IsMin a := fun ha => ha.not_lt h
#align not_is_min_of_lt not_isMin_of_lt
@[simp]
theorem not_isMax_of_lt (h : a < b) : ¬IsMax a := fun ha => ha.not_lt h
#align not_is_max_of_lt not_isMax_of_lt
alias LT.lt.not_isMin := not_isMin_of_lt
alias LT.lt.not_isMax := not_isMax_of_lt
theorem isMin_iff_forall_not_lt : IsMin a ↔ ∀ b, ¬b < a :=
⟨fun h _ => h.not_lt, fun h _ hba => of_not_not fun hab => h _ <| hba.lt_of_not_le hab⟩
#align is_min_iff_forall_not_lt isMin_iff_forall_not_lt
theorem isMax_iff_forall_not_lt : IsMax a ↔ ∀ b, ¬a < b :=
⟨fun h _ => h.not_lt, fun h _ hba => of_not_not fun hab => h _ <| hba.lt_of_not_le hab⟩
#align is_max_iff_forall_not_lt isMax_iff_forall_not_lt
@[simp]
theorem not_isMin_iff : ¬IsMin a ↔ ∃ b, b < a := by
simp [lt_iff_le_not_le, IsMin, not_forall, exists_prop]
#align not_is_min_iff not_isMin_iff
@[simp]
| Mathlib/Order/Max.lean | 345 | 346 | theorem not_isMax_iff : ¬IsMax a ↔ ∃ b, a < b := by |
simp [lt_iff_le_not_le, IsMax, not_forall, exists_prop]
|
import Mathlib.Algebra.Group.Nat
set_option autoImplicit true
open Lean hiding Literal HashMap
open Batteries
namespace Sat
inductive Literal
| pos : Nat → Literal
| neg : Nat → Literal
def Literal.ofInt (i : Int) : Literal :=
if i < 0 then Literal.neg (-i-1).toNat else Literal.pos (i-1).toNat
def Literal.negate : Literal → Literal
| pos i => neg i
| neg i => pos i
instance : ToExpr Literal where
toTypeExpr := mkConst ``Literal
toExpr
| Literal.pos i => mkApp (mkConst ``Literal.pos) (mkRawNatLit i)
| Literal.neg i => mkApp (mkConst ``Literal.neg) (mkRawNatLit i)
def Clause := List Literal
def Clause.nil : Clause := []
def Clause.cons : Literal → Clause → Clause := List.cons
abbrev Fmla := List Clause
def Fmla.one (c : Clause) : Fmla := [c]
def Fmla.and (a b : Fmla) : Fmla := a ++ b
structure Fmla.subsumes (f f' : Fmla) : Prop where
prop : ∀ x, x ∈ f' → x ∈ f
theorem Fmla.subsumes_self (f : Fmla) : f.subsumes f := ⟨fun _ h ↦ h⟩
theorem Fmla.subsumes_left (f f₁ f₂ : Fmla) (H : f.subsumes (f₁.and f₂)) : f.subsumes f₁ :=
⟨fun _ h ↦ H.1 _ <| List.mem_append.2 <| Or.inl h⟩
theorem Fmla.subsumes_right (f f₁ f₂ : Fmla) (H : f.subsumes (f₁.and f₂)) : f.subsumes f₂ :=
⟨fun _ h ↦ H.1 _ <| List.mem_append.2 <| Or.inr h⟩
def Valuation := Nat → Prop
def Valuation.neg (v : Valuation) : Literal → Prop
| Literal.pos i => ¬ v i
| Literal.neg i => v i
def Valuation.satisfies (v : Valuation) : Clause → Prop
| [] => False
| l::c => v.neg l → v.satisfies c
structure Valuation.satisfies_fmla (v : Valuation) (f : Fmla) : Prop where
prop : ∀ c, c ∈ f → v.satisfies c
def Fmla.proof (f : Fmla) (c : Clause) : Prop :=
∀ v : Valuation, v.satisfies_fmla f → v.satisfies c
theorem Fmla.proof_of_subsumes (H : Fmla.subsumes f (Fmla.one c)) : f.proof c :=
fun _ h ↦ h.1 _ <| H.1 _ <| List.Mem.head ..
theorem Valuation.by_cases {v : Valuation} {l}
(h₁ : v.neg l.negate → False) (h₂ : v.neg l → False) : False :=
match l with
| Literal.pos _ => h₂ h₁
| Literal.neg _ => h₁ h₂
def Valuation.implies (v : Valuation) (p : Prop) : List Prop → Nat → Prop
| [], _ => p
| a::as, n => (v n ↔ a) → v.implies p as (n+1)
def Valuation.mk : List Prop → Valuation
| [], _ => False
| a::_, 0 => a
| _::as, n+1 => mk as n
theorem Valuation.mk_implies {as ps} (as₁) : as = List.reverseAux as₁ ps →
(Valuation.mk as).implies p ps as₁.length → p := by
induction ps generalizing as₁ with
| nil => exact fun _ ↦ id
| cons a as ih =>
refine fun e H ↦ @ih (a::as₁) e (H ?_)
subst e; clear ih H
suffices ∀ n n', n' = List.length as₁ + n →
∀ bs, mk (as₁.reverseAux bs) n' ↔ mk bs n from this 0 _ rfl (a::as)
induction as₁ with simp
| cons b as₁ ih => exact fun n bs ↦ ih (n+1) _ (Nat.succ_add ..) _
structure Fmla.reify (v : Valuation) (f : Fmla) (p : Prop) : Prop where
prop : ¬ v.satisfies_fmla f → p
theorem Fmla.refute {ps} (f : Fmla) (hf : f.proof [])
(hv : ∀ v, Valuation.implies v (Fmla.reify v f p) ps 0) : p :=
(Valuation.mk_implies [] rfl (hv _)).1 (hf _)
| Mathlib/Tactic/Sat/FromLRAT.lean | 180 | 185 | theorem Fmla.reify_or (h₁ : Fmla.reify v f₁ a) (h₂ : Fmla.reify v f₂ b) :
Fmla.reify v (f₁.and f₂) (a ∨ b) := by |
refine ⟨fun H ↦ by_contra fun hn ↦ H ⟨fun c h ↦ by_contra fun hn' ↦ ?_⟩⟩
rcases List.mem_append.1 h with h | h
· exact hn <| Or.inl <| h₁.1 fun Hc ↦ hn' <| Hc.1 _ h
· exact hn <| Or.inr <| h₂.1 fun Hc ↦ hn' <| Hc.1 _ h
|
import Mathlib.LinearAlgebra.Dimension.Constructions
import Mathlib.LinearAlgebra.Dimension.Finite
universe u v
open Function Set Cardinal
variable {R} {M M₁ M₂ M₃ : Type u} {M' : Type v} [Ring R]
variable [AddCommGroup M] [AddCommGroup M₁] [AddCommGroup M₂] [AddCommGroup M₃] [AddCommGroup M']
variable [Module R M] [Module R M₁] [Module R M₂] [Module R M₃] [Module R M']
@[pp_with_univ]
class HasRankNullity (R : Type v) [inst : Ring R] : Prop where
exists_set_linearIndependent : ∀ (M : Type u) [AddCommGroup M] [Module R M],
∃ s : Set M, #s = Module.rank R M ∧ LinearIndependent (ι := s) R Subtype.val
rank_quotient_add_rank : ∀ {M : Type u} [AddCommGroup M] [Module R M] (N : Submodule R M),
Module.rank R (M ⧸ N) + Module.rank R N = Module.rank R M
variable [HasRankNullity.{u} R]
lemma rank_quotient_add_rank (N : Submodule R M) :
Module.rank R (M ⧸ N) + Module.rank R N = Module.rank R M :=
HasRankNullity.rank_quotient_add_rank N
#align rank_quotient_add_rank rank_quotient_add_rank
variable (R M) in
lemma exists_set_linearIndependent :
∃ s : Set M, #s = Module.rank R M ∧ LinearIndependent (ι := s) R Subtype.val :=
HasRankNullity.exists_set_linearIndependent M
variable (R) in
instance (priority := 100) : Nontrivial R := by
refine (subsingleton_or_nontrivial R).resolve_left fun H ↦ ?_
have := rank_quotient_add_rank (R := R) (M := PUnit) ⊥
simp [one_add_one_eq_two] at this
| Mathlib/LinearAlgebra/Dimension/RankNullity.lean | 68 | 72 | theorem lift_rank_range_add_rank_ker (f : M →ₗ[R] M') :
lift.{u} (Module.rank R (LinearMap.range f)) + lift.{v} (Module.rank R (LinearMap.ker f)) =
lift.{v} (Module.rank R M) := by |
haveI := fun p : Submodule R M => Classical.decEq (M ⧸ p)
rw [← f.quotKerEquivRange.lift_rank_eq, ← lift_add, rank_quotient_add_rank]
|
import Mathlib.Analysis.Calculus.FDeriv.Equiv
import Mathlib.Analysis.Calculus.FormalMultilinearSeries
#align_import analysis.calculus.cont_diff_def from "leanprover-community/mathlib"@"3a69562db5a458db8322b190ec8d9a8bbd8a5b14"
noncomputable section
open scoped Classical
open NNReal Topology Filter
local notation "∞" => (⊤ : ℕ∞)
open Set Fin Filter Function
universe u uE uF uG uX
variable {𝕜 : Type u} [NontriviallyNormedField 𝕜] {E : Type uE} [NormedAddCommGroup E]
[NormedSpace 𝕜 E] {F : Type uF} [NormedAddCommGroup F] [NormedSpace 𝕜 F] {G : Type uG}
[NormedAddCommGroup G] [NormedSpace 𝕜 G] {X : Type uX} [NormedAddCommGroup X] [NormedSpace 𝕜 X]
{s s₁ t u : Set E} {f f₁ : E → F} {g : F → G} {x x₀ : E} {c : F} {m n : ℕ∞}
{p : E → FormalMultilinearSeries 𝕜 E F}
structure HasFTaylorSeriesUpToOn (n : ℕ∞) (f : E → F) (p : E → FormalMultilinearSeries 𝕜 E F)
(s : Set E) : Prop where
zero_eq : ∀ x ∈ s, (p x 0).uncurry0 = f x
protected fderivWithin : ∀ m : ℕ, (m : ℕ∞) < n → ∀ x ∈ s,
HasFDerivWithinAt (p · m) (p x m.succ).curryLeft s x
cont : ∀ m : ℕ, (m : ℕ∞) ≤ n → ContinuousOn (p · m) s
#align has_ftaylor_series_up_to_on HasFTaylorSeriesUpToOn
theorem HasFTaylorSeriesUpToOn.zero_eq' (h : HasFTaylorSeriesUpToOn n f p s) {x : E} (hx : x ∈ s) :
p x 0 = (continuousMultilinearCurryFin0 𝕜 E F).symm (f x) := by
rw [← h.zero_eq x hx]
exact (p x 0).uncurry0_curry0.symm
#align has_ftaylor_series_up_to_on.zero_eq' HasFTaylorSeriesUpToOn.zero_eq'
theorem HasFTaylorSeriesUpToOn.congr (h : HasFTaylorSeriesUpToOn n f p s)
(h₁ : ∀ x ∈ s, f₁ x = f x) : HasFTaylorSeriesUpToOn n f₁ p s := by
refine ⟨fun x hx => ?_, h.fderivWithin, h.cont⟩
rw [h₁ x hx]
exact h.zero_eq x hx
#align has_ftaylor_series_up_to_on.congr HasFTaylorSeriesUpToOn.congr
theorem HasFTaylorSeriesUpToOn.mono (h : HasFTaylorSeriesUpToOn n f p s) {t : Set E} (hst : t ⊆ s) :
HasFTaylorSeriesUpToOn n f p t :=
⟨fun x hx => h.zero_eq x (hst hx), fun m hm x hx => (h.fderivWithin m hm x (hst hx)).mono hst,
fun m hm => (h.cont m hm).mono hst⟩
#align has_ftaylor_series_up_to_on.mono HasFTaylorSeriesUpToOn.mono
theorem HasFTaylorSeriesUpToOn.of_le (h : HasFTaylorSeriesUpToOn n f p s) (hmn : m ≤ n) :
HasFTaylorSeriesUpToOn m f p s :=
⟨h.zero_eq, fun k hk x hx => h.fderivWithin k (lt_of_lt_of_le hk hmn) x hx, fun k hk =>
h.cont k (le_trans hk hmn)⟩
#align has_ftaylor_series_up_to_on.of_le HasFTaylorSeriesUpToOn.of_le
theorem HasFTaylorSeriesUpToOn.continuousOn (h : HasFTaylorSeriesUpToOn n f p s) :
ContinuousOn f s := by
have := (h.cont 0 bot_le).congr fun x hx => (h.zero_eq' hx).symm
rwa [← (continuousMultilinearCurryFin0 𝕜 E F).symm.comp_continuousOn_iff]
#align has_ftaylor_series_up_to_on.continuous_on HasFTaylorSeriesUpToOn.continuousOn
theorem hasFTaylorSeriesUpToOn_zero_iff :
HasFTaylorSeriesUpToOn 0 f p s ↔ ContinuousOn f s ∧ ∀ x ∈ s, (p x 0).uncurry0 = f x := by
refine ⟨fun H => ⟨H.continuousOn, H.zero_eq⟩, fun H =>
⟨H.2, fun m hm => False.elim (not_le.2 hm bot_le), fun m hm ↦ ?_⟩⟩
obtain rfl : m = 0 := mod_cast hm.antisymm (zero_le _)
have : EqOn (p · 0) ((continuousMultilinearCurryFin0 𝕜 E F).symm ∘ f) s := fun x hx ↦
(continuousMultilinearCurryFin0 𝕜 E F).eq_symm_apply.2 (H.2 x hx)
rw [continuousOn_congr this, LinearIsometryEquiv.comp_continuousOn_iff]
exact H.1
#align has_ftaylor_series_up_to_on_zero_iff hasFTaylorSeriesUpToOn_zero_iff
theorem hasFTaylorSeriesUpToOn_top_iff :
HasFTaylorSeriesUpToOn ∞ f p s ↔ ∀ n : ℕ, HasFTaylorSeriesUpToOn n f p s := by
constructor
· intro H n; exact H.of_le le_top
· intro H
constructor
· exact (H 0).zero_eq
· intro m _
apply (H m.succ).fderivWithin m (WithTop.coe_lt_coe.2 (lt_add_one m))
· intro m _
apply (H m).cont m le_rfl
#align has_ftaylor_series_up_to_on_top_iff hasFTaylorSeriesUpToOn_top_iff
theorem hasFTaylorSeriesUpToOn_top_iff' :
HasFTaylorSeriesUpToOn ∞ f p s ↔
(∀ x ∈ s, (p x 0).uncurry0 = f x) ∧
∀ m : ℕ, ∀ x ∈ s, HasFDerivWithinAt (fun y => p y m) (p x m.succ).curryLeft s x :=
-- Everything except for the continuity is trivial:
⟨fun h => ⟨h.1, fun m => h.2 m (WithTop.coe_lt_top m)⟩, fun h =>
⟨h.1, fun m _ => h.2 m, fun m _ x hx =>
-- The continuity follows from the existence of a derivative:
(h.2 m x hx).continuousWithinAt⟩⟩
#align has_ftaylor_series_up_to_on_top_iff' hasFTaylorSeriesUpToOn_top_iff'
theorem HasFTaylorSeriesUpToOn.hasFDerivWithinAt (h : HasFTaylorSeriesUpToOn n f p s) (hn : 1 ≤ n)
(hx : x ∈ s) : HasFDerivWithinAt f (continuousMultilinearCurryFin1 𝕜 E F (p x 1)) s x := by
have A : ∀ y ∈ s, f y = (continuousMultilinearCurryFin0 𝕜 E F) (p y 0) := fun y hy ↦
(h.zero_eq y hy).symm
suffices H : HasFDerivWithinAt (continuousMultilinearCurryFin0 𝕜 E F ∘ (p · 0))
(continuousMultilinearCurryFin1 𝕜 E F (p x 1)) s x from H.congr A (A x hx)
rw [LinearIsometryEquiv.comp_hasFDerivWithinAt_iff']
have : ((0 : ℕ) : ℕ∞) < n := zero_lt_one.trans_le hn
convert h.fderivWithin _ this x hx
ext y v
change (p x 1) (snoc 0 y) = (p x 1) (cons y v)
congr with i
rw [Unique.eq_default (α := Fin 1) i]
rfl
#align has_ftaylor_series_up_to_on.has_fderiv_within_at HasFTaylorSeriesUpToOn.hasFDerivWithinAt
theorem HasFTaylorSeriesUpToOn.differentiableOn (h : HasFTaylorSeriesUpToOn n f p s) (hn : 1 ≤ n) :
DifferentiableOn 𝕜 f s := fun _x hx => (h.hasFDerivWithinAt hn hx).differentiableWithinAt
#align has_ftaylor_series_up_to_on.differentiable_on HasFTaylorSeriesUpToOn.differentiableOn
theorem HasFTaylorSeriesUpToOn.hasFDerivAt (h : HasFTaylorSeriesUpToOn n f p s) (hn : 1 ≤ n)
(hx : s ∈ 𝓝 x) : HasFDerivAt f (continuousMultilinearCurryFin1 𝕜 E F (p x 1)) x :=
(h.hasFDerivWithinAt hn (mem_of_mem_nhds hx)).hasFDerivAt hx
#align has_ftaylor_series_up_to_on.has_fderiv_at HasFTaylorSeriesUpToOn.hasFDerivAt
theorem HasFTaylorSeriesUpToOn.eventually_hasFDerivAt (h : HasFTaylorSeriesUpToOn n f p s)
(hn : 1 ≤ n) (hx : s ∈ 𝓝 x) :
∀ᶠ y in 𝓝 x, HasFDerivAt f (continuousMultilinearCurryFin1 𝕜 E F (p y 1)) y :=
(eventually_eventually_nhds.2 hx).mono fun _y hy => h.hasFDerivAt hn hy
#align has_ftaylor_series_up_to_on.eventually_has_fderiv_at HasFTaylorSeriesUpToOn.eventually_hasFDerivAt
theorem HasFTaylorSeriesUpToOn.differentiableAt (h : HasFTaylorSeriesUpToOn n f p s) (hn : 1 ≤ n)
(hx : s ∈ 𝓝 x) : DifferentiableAt 𝕜 f x :=
(h.hasFDerivAt hn hx).differentiableAt
#align has_ftaylor_series_up_to_on.differentiable_at HasFTaylorSeriesUpToOn.differentiableAt
theorem hasFTaylorSeriesUpToOn_succ_iff_left {n : ℕ} :
HasFTaylorSeriesUpToOn (n + 1) f p s ↔
HasFTaylorSeriesUpToOn n f p s ∧
(∀ x ∈ s, HasFDerivWithinAt (fun y => p y n) (p x n.succ).curryLeft s x) ∧
ContinuousOn (fun x => p x (n + 1)) s := by
constructor
· exact fun h ↦ ⟨h.of_le (WithTop.coe_le_coe.2 (Nat.le_succ n)),
h.fderivWithin _ (WithTop.coe_lt_coe.2 (lt_add_one n)), h.cont (n + 1) le_rfl⟩
· intro h
constructor
· exact h.1.zero_eq
· intro m hm
by_cases h' : m < n
· exact h.1.fderivWithin m (WithTop.coe_lt_coe.2 h')
· have : m = n := Nat.eq_of_lt_succ_of_not_lt (WithTop.coe_lt_coe.1 hm) h'
rw [this]
exact h.2.1
· intro m hm
by_cases h' : m ≤ n
· apply h.1.cont m (WithTop.coe_le_coe.2 h')
· have : m = n + 1 := le_antisymm (WithTop.coe_le_coe.1 hm) (not_le.1 h')
rw [this]
exact h.2.2
#align has_ftaylor_series_up_to_on_succ_iff_left hasFTaylorSeriesUpToOn_succ_iff_left
#adaptation_note
set_option maxSynthPendingDepth 2 in
-- Porting note: this was split out from `hasFTaylorSeriesUpToOn_succ_iff_right` to avoid a timeout.
theorem HasFTaylorSeriesUpToOn.shift_of_succ
{n : ℕ} (H : HasFTaylorSeriesUpToOn (n + 1 : ℕ) f p s) :
(HasFTaylorSeriesUpToOn n (fun x => continuousMultilinearCurryFin1 𝕜 E F (p x 1))
(fun x => (p x).shift)) s := by
constructor
· intro x _
rfl
· intro m (hm : (m : ℕ∞) < n) x (hx : x ∈ s)
have A : (m.succ : ℕ∞) < n.succ := by
rw [Nat.cast_lt] at hm ⊢
exact Nat.succ_lt_succ hm
change HasFDerivWithinAt ((continuousMultilinearCurryRightEquiv' 𝕜 m E F).symm ∘ (p · m.succ))
(p x m.succ.succ).curryRight.curryLeft s x
rw [((continuousMultilinearCurryRightEquiv' 𝕜 m E F).symm).comp_hasFDerivWithinAt_iff']
convert H.fderivWithin _ A x hx
ext y v
change p x (m + 2) (snoc (cons y (init v)) (v (last _))) = p x (m + 2) (cons y v)
rw [← cons_snoc_eq_snoc_cons, snoc_init_self]
· intro m (hm : (m : ℕ∞) ≤ n)
suffices A : ContinuousOn (p · (m + 1)) s from
((continuousMultilinearCurryRightEquiv' 𝕜 m E F).symm).continuous.comp_continuousOn A
refine H.cont _ ?_
rw [Nat.cast_le] at hm ⊢
exact Nat.succ_le_succ hm
theorem hasFTaylorSeriesUpToOn_succ_iff_right {n : ℕ} :
HasFTaylorSeriesUpToOn (n + 1 : ℕ) f p s ↔
(∀ x ∈ s, (p x 0).uncurry0 = f x) ∧
(∀ x ∈ s, HasFDerivWithinAt (fun y => p y 0) (p x 1).curryLeft s x) ∧
HasFTaylorSeriesUpToOn n (fun x => continuousMultilinearCurryFin1 𝕜 E F (p x 1))
(fun x => (p x).shift) s := by
constructor
· intro H
refine ⟨H.zero_eq, H.fderivWithin 0 (Nat.cast_lt.2 (Nat.succ_pos n)), ?_⟩
exact H.shift_of_succ
· rintro ⟨Hzero_eq, Hfderiv_zero, Htaylor⟩
constructor
· exact Hzero_eq
· intro m (hm : (m : ℕ∞) < n.succ) x (hx : x ∈ s)
cases' m with m
· exact Hfderiv_zero x hx
· have A : (m : ℕ∞) < n := by
rw [Nat.cast_lt] at hm ⊢
exact Nat.lt_of_succ_lt_succ hm
have :
HasFDerivWithinAt ((continuousMultilinearCurryRightEquiv' 𝕜 m E F).symm ∘ (p · m.succ))
((p x).shift m.succ).curryLeft s x := Htaylor.fderivWithin _ A x hx
rw [LinearIsometryEquiv.comp_hasFDerivWithinAt_iff'] at this
convert this
ext y v
change
(p x (Nat.succ (Nat.succ m))) (cons y v) =
(p x m.succ.succ) (snoc (cons y (init v)) (v (last _)))
rw [← cons_snoc_eq_snoc_cons, snoc_init_self]
· intro m (hm : (m : ℕ∞) ≤ n.succ)
cases' m with m
· have : DifferentiableOn 𝕜 (fun x => p x 0) s := fun x hx =>
(Hfderiv_zero x hx).differentiableWithinAt
exact this.continuousOn
· refine (continuousMultilinearCurryRightEquiv' 𝕜 m E F).symm.comp_continuousOn_iff.mp ?_
refine Htaylor.cont _ ?_
rw [Nat.cast_le] at hm ⊢
exact Nat.lt_succ_iff.mp hm
#align has_ftaylor_series_up_to_on_succ_iff_right hasFTaylorSeriesUpToOn_succ_iff_right
variable (𝕜)
def ContDiffWithinAt (n : ℕ∞) (f : E → F) (s : Set E) (x : E) : Prop :=
∀ m : ℕ, (m : ℕ∞) ≤ n → ∃ u ∈ 𝓝[insert x s] x,
∃ p : E → FormalMultilinearSeries 𝕜 E F, HasFTaylorSeriesUpToOn m f p u
#align cont_diff_within_at ContDiffWithinAt
variable {𝕜}
theorem contDiffWithinAt_nat {n : ℕ} :
ContDiffWithinAt 𝕜 n f s x ↔ ∃ u ∈ 𝓝[insert x s] x,
∃ p : E → FormalMultilinearSeries 𝕜 E F, HasFTaylorSeriesUpToOn n f p u :=
⟨fun H => H n le_rfl, fun ⟨u, hu, p, hp⟩ _m hm => ⟨u, hu, p, hp.of_le hm⟩⟩
#align cont_diff_within_at_nat contDiffWithinAt_nat
theorem ContDiffWithinAt.of_le (h : ContDiffWithinAt 𝕜 n f s x) (hmn : m ≤ n) :
ContDiffWithinAt 𝕜 m f s x := fun k hk => h k (le_trans hk hmn)
#align cont_diff_within_at.of_le ContDiffWithinAt.of_le
theorem contDiffWithinAt_iff_forall_nat_le :
ContDiffWithinAt 𝕜 n f s x ↔ ∀ m : ℕ, ↑m ≤ n → ContDiffWithinAt 𝕜 m f s x :=
⟨fun H _m hm => H.of_le hm, fun H m hm => H m hm _ le_rfl⟩
#align cont_diff_within_at_iff_forall_nat_le contDiffWithinAt_iff_forall_nat_le
theorem contDiffWithinAt_top : ContDiffWithinAt 𝕜 ∞ f s x ↔ ∀ n : ℕ, ContDiffWithinAt 𝕜 n f s x :=
contDiffWithinAt_iff_forall_nat_le.trans <| by simp only [forall_prop_of_true, le_top]
#align cont_diff_within_at_top contDiffWithinAt_top
theorem ContDiffWithinAt.continuousWithinAt (h : ContDiffWithinAt 𝕜 n f s x) :
ContinuousWithinAt f s x := by
rcases h 0 bot_le with ⟨u, hu, p, H⟩
rw [mem_nhdsWithin_insert] at hu
exact (H.continuousOn.continuousWithinAt hu.1).mono_of_mem hu.2
#align cont_diff_within_at.continuous_within_at ContDiffWithinAt.continuousWithinAt
theorem ContDiffWithinAt.congr_of_eventuallyEq (h : ContDiffWithinAt 𝕜 n f s x)
(h₁ : f₁ =ᶠ[𝓝[s] x] f) (hx : f₁ x = f x) : ContDiffWithinAt 𝕜 n f₁ s x := fun m hm =>
let ⟨u, hu, p, H⟩ := h m hm
⟨{ x ∈ u | f₁ x = f x }, Filter.inter_mem hu (mem_nhdsWithin_insert.2 ⟨hx, h₁⟩), p,
(H.mono (sep_subset _ _)).congr fun _ => And.right⟩
#align cont_diff_within_at.congr_of_eventually_eq ContDiffWithinAt.congr_of_eventuallyEq
theorem ContDiffWithinAt.congr_of_eventuallyEq_insert (h : ContDiffWithinAt 𝕜 n f s x)
(h₁ : f₁ =ᶠ[𝓝[insert x s] x] f) : ContDiffWithinAt 𝕜 n f₁ s x :=
h.congr_of_eventuallyEq (nhdsWithin_mono x (subset_insert x s) h₁)
(mem_of_mem_nhdsWithin (mem_insert x s) h₁ : _)
#align cont_diff_within_at.congr_of_eventually_eq_insert ContDiffWithinAt.congr_of_eventuallyEq_insert
theorem ContDiffWithinAt.congr_of_eventually_eq' (h : ContDiffWithinAt 𝕜 n f s x)
(h₁ : f₁ =ᶠ[𝓝[s] x] f) (hx : x ∈ s) : ContDiffWithinAt 𝕜 n f₁ s x :=
h.congr_of_eventuallyEq h₁ <| h₁.self_of_nhdsWithin hx
#align cont_diff_within_at.congr_of_eventually_eq' ContDiffWithinAt.congr_of_eventually_eq'
theorem Filter.EventuallyEq.contDiffWithinAt_iff (h₁ : f₁ =ᶠ[𝓝[s] x] f) (hx : f₁ x = f x) :
ContDiffWithinAt 𝕜 n f₁ s x ↔ ContDiffWithinAt 𝕜 n f s x :=
⟨fun H => ContDiffWithinAt.congr_of_eventuallyEq H h₁.symm hx.symm, fun H =>
H.congr_of_eventuallyEq h₁ hx⟩
#align filter.eventually_eq.cont_diff_within_at_iff Filter.EventuallyEq.contDiffWithinAt_iff
theorem ContDiffWithinAt.congr (h : ContDiffWithinAt 𝕜 n f s x) (h₁ : ∀ y ∈ s, f₁ y = f y)
(hx : f₁ x = f x) : ContDiffWithinAt 𝕜 n f₁ s x :=
h.congr_of_eventuallyEq (Filter.eventuallyEq_of_mem self_mem_nhdsWithin h₁) hx
#align cont_diff_within_at.congr ContDiffWithinAt.congr
theorem ContDiffWithinAt.congr' (h : ContDiffWithinAt 𝕜 n f s x) (h₁ : ∀ y ∈ s, f₁ y = f y)
(hx : x ∈ s) : ContDiffWithinAt 𝕜 n f₁ s x :=
h.congr h₁ (h₁ _ hx)
#align cont_diff_within_at.congr' ContDiffWithinAt.congr'
theorem ContDiffWithinAt.mono_of_mem (h : ContDiffWithinAt 𝕜 n f s x) {t : Set E}
(hst : s ∈ 𝓝[t] x) : ContDiffWithinAt 𝕜 n f t x := by
intro m hm
rcases h m hm with ⟨u, hu, p, H⟩
exact ⟨u, nhdsWithin_le_of_mem (insert_mem_nhdsWithin_insert hst) hu, p, H⟩
#align cont_diff_within_at.mono_of_mem ContDiffWithinAt.mono_of_mem
theorem ContDiffWithinAt.mono (h : ContDiffWithinAt 𝕜 n f s x) {t : Set E} (hst : t ⊆ s) :
ContDiffWithinAt 𝕜 n f t x :=
h.mono_of_mem <| Filter.mem_of_superset self_mem_nhdsWithin hst
#align cont_diff_within_at.mono ContDiffWithinAt.mono
theorem ContDiffWithinAt.congr_nhds (h : ContDiffWithinAt 𝕜 n f s x) {t : Set E}
(hst : 𝓝[s] x = 𝓝[t] x) : ContDiffWithinAt 𝕜 n f t x :=
h.mono_of_mem <| hst ▸ self_mem_nhdsWithin
#align cont_diff_within_at.congr_nhds ContDiffWithinAt.congr_nhds
theorem contDiffWithinAt_congr_nhds {t : Set E} (hst : 𝓝[s] x = 𝓝[t] x) :
ContDiffWithinAt 𝕜 n f s x ↔ ContDiffWithinAt 𝕜 n f t x :=
⟨fun h => h.congr_nhds hst, fun h => h.congr_nhds hst.symm⟩
#align cont_diff_within_at_congr_nhds contDiffWithinAt_congr_nhds
theorem contDiffWithinAt_inter' (h : t ∈ 𝓝[s] x) :
ContDiffWithinAt 𝕜 n f (s ∩ t) x ↔ ContDiffWithinAt 𝕜 n f s x :=
contDiffWithinAt_congr_nhds <| Eq.symm <| nhdsWithin_restrict'' _ h
#align cont_diff_within_at_inter' contDiffWithinAt_inter'
theorem contDiffWithinAt_inter (h : t ∈ 𝓝 x) :
ContDiffWithinAt 𝕜 n f (s ∩ t) x ↔ ContDiffWithinAt 𝕜 n f s x :=
contDiffWithinAt_inter' (mem_nhdsWithin_of_mem_nhds h)
#align cont_diff_within_at_inter contDiffWithinAt_inter
theorem contDiffWithinAt_insert_self :
ContDiffWithinAt 𝕜 n f (insert x s) x ↔ ContDiffWithinAt 𝕜 n f s x := by
simp_rw [ContDiffWithinAt, insert_idem]
| Mathlib/Analysis/Calculus/ContDiff/Defs.lean | 526 | 530 | theorem contDiffWithinAt_insert {y : E} :
ContDiffWithinAt 𝕜 n f (insert y s) x ↔ ContDiffWithinAt 𝕜 n f s x := by |
rcases eq_or_ne x y with (rfl | h)
· exact contDiffWithinAt_insert_self
simp_rw [ContDiffWithinAt, insert_comm x y, nhdsWithin_insert_of_ne h]
|
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