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import Mathlib.Analysis.BoxIntegral.Basic
import Mathlib.MeasureTheory.Integral.SetIntegral
import Mathlib.Tactic.Generalize
#align_import analysis.box_integral.integrability from "leanprover-community/mathlib"@"fd5edc43dc4f10b85abfe544b88f82cf13c5f844"
open scoped Classical NNReal ENNReal Topology
universe u v
variable {ι : Type u} {E : Type v} [Fintype ι] [NormedAddCommGroup E] [NormedSpace ℝ E]
open MeasureTheory Metric Set Finset Filter BoxIntegral
namespace BoxIntegral
| Mathlib/Analysis/BoxIntegral/Integrability.lean | 39 | 99 | theorem hasIntegralIndicatorConst (l : IntegrationParams) (hl : l.bRiemann = false)
{s : Set (ι → ℝ)} (hs : MeasurableSet s) (I : Box ι) (y : E) (μ : Measure (ι → ℝ))
[IsLocallyFiniteMeasure μ] :
HasIntegral.{u, v, v} I l (s.indicator fun _ => y) μ.toBoxAdditive.toSMul
((μ (s ∩ I)).toReal • y) := by |
refine HasIntegral.of_mul ‖y‖ fun ε ε0 => ?_
lift ε to ℝ≥0 using ε0.le; rw [NNReal.coe_pos] at ε0
/- First we choose a closed set `F ⊆ s ∩ I.Icc` and an open set `U ⊇ s` such that
both `(s ∩ I.Icc) \ F` and `U \ s` have measure less than `ε`. -/
have A : μ (s ∩ Box.Icc I) ≠ ∞ :=
((measure_mono Set.inter_subset_right).trans_lt (I.measure_Icc_lt_top μ)).ne
have B : μ (s ∩ I) ≠ ∞ :=
((measure_mono Set.inter_subset_right).trans_lt (I.measure_coe_lt_top μ)).ne
obtain ⟨F, hFs, hFc, hμF⟩ : ∃ F, F ⊆ s ∩ Box.Icc I ∧ IsClosed F ∧ μ ((s ∩ Box.Icc I) \ F) < ε :=
(hs.inter I.measurableSet_Icc).exists_isClosed_diff_lt A (ENNReal.coe_pos.2 ε0).ne'
obtain ⟨U, hsU, hUo, hUt, hμU⟩ :
∃ U, s ∩ Box.Icc I ⊆ U ∧ IsOpen U ∧ μ U < ∞ ∧ μ (U \ (s ∩ Box.Icc I)) < ε :=
(hs.inter I.measurableSet_Icc).exists_isOpen_diff_lt A (ENNReal.coe_pos.2 ε0).ne'
/- Then we choose `r` so that `closed_ball x (r x) ⊆ U` whenever `x ∈ s ∩ I.Icc` and
`closed_ball x (r x)` is disjoint with `F` otherwise. -/
have : ∀ x ∈ s ∩ Box.Icc I, ∃ r : Ioi (0 : ℝ), closedBall x r ⊆ U := fun x hx => by
rcases nhds_basis_closedBall.mem_iff.1 (hUo.mem_nhds <| hsU hx) with ⟨r, hr₀, hr⟩
exact ⟨⟨r, hr₀⟩, hr⟩
choose! rs hrsU using this
have : ∀ x ∈ Box.Icc I \ s, ∃ r : Ioi (0 : ℝ), closedBall x r ⊆ Fᶜ := fun x hx => by
obtain ⟨r, hr₀, hr⟩ :=
nhds_basis_closedBall.mem_iff.1 (hFc.isOpen_compl.mem_nhds fun hx' => hx.2 (hFs hx').1)
exact ⟨⟨r, hr₀⟩, hr⟩
choose! rs' hrs'F using this
set r : (ι → ℝ) → Ioi (0 : ℝ) := s.piecewise rs rs'
refine ⟨fun _ => r, fun c => l.rCond_of_bRiemann_eq_false hl, fun c π hπ hπp => ?_⟩; rw [mul_comm]
/- Then the union of boxes `J ∈ π` such that `π.tag ∈ s` includes `F` and is included by `U`,
hence its measure is `ε`-close to the measure of `s`. -/
dsimp [integralSum]
simp only [mem_closedBall, dist_eq_norm, ← indicator_const_smul_apply,
sum_indicator_eq_sum_filter, ← sum_smul, ← sub_smul, norm_smul, Real.norm_eq_abs, ←
Prepartition.filter_boxes, ← Prepartition.measure_iUnion_toReal]
gcongr
set t := (π.filter (π.tag · ∈ s)).iUnion
change abs ((μ t).toReal - (μ (s ∩ I)).toReal) ≤ ε
have htU : t ⊆ U ∩ I := by
simp only [t, TaggedPrepartition.iUnion_def, iUnion_subset_iff, TaggedPrepartition.mem_filter,
and_imp]
refine fun J hJ hJs x hx => ⟨hrsU _ ⟨hJs, π.tag_mem_Icc J⟩ ?_, π.le_of_mem' J hJ hx⟩
simpa only [r, s.piecewise_eq_of_mem _ _ hJs] using hπ.1 J hJ (Box.coe_subset_Icc hx)
refine abs_sub_le_iff.2 ⟨?_, ?_⟩
· refine (ENNReal.le_toReal_sub B).trans (ENNReal.toReal_le_coe_of_le_coe ?_)
refine (tsub_le_tsub (measure_mono htU) le_rfl).trans (le_measure_diff.trans ?_)
refine (measure_mono fun x hx => ?_).trans hμU.le
exact ⟨hx.1.1, fun hx' => hx.2 ⟨hx'.1, hx.1.2⟩⟩
· have hμt : μ t ≠ ∞ := ((measure_mono (htU.trans inter_subset_left)).trans_lt hUt).ne
refine (ENNReal.le_toReal_sub hμt).trans (ENNReal.toReal_le_coe_of_le_coe ?_)
refine le_measure_diff.trans ((measure_mono ?_).trans hμF.le)
rintro x ⟨⟨hxs, hxI⟩, hxt⟩
refine ⟨⟨hxs, Box.coe_subset_Icc hxI⟩, fun hxF => hxt ?_⟩
simp only [t, TaggedPrepartition.iUnion_def, TaggedPrepartition.mem_filter, Set.mem_iUnion]
rcases hπp x hxI with ⟨J, hJπ, hxJ⟩
refine ⟨J, ⟨hJπ, ?_⟩, hxJ⟩
contrapose hxF
refine hrs'F _ ⟨π.tag_mem_Icc J, hxF⟩ ?_
simpa only [r, s.piecewise_eq_of_not_mem _ _ hxF] using hπ.1 J hJπ (Box.coe_subset_Icc hxJ)
|
import Mathlib.Analysis.Normed.Field.InfiniteSum
import Mathlib.Analysis.SpecificLimits.Normed
import Mathlib.NumberTheory.ArithmeticFunction
import Mathlib.NumberTheory.SmoothNumbers
lemma Summable.norm_lt_one {F : Type*} [NormedField F] [CompleteSpace F] {f : ℕ →* F}
(hsum : Summable f) {p : ℕ} (hp : 1 < p) :
‖f p‖ < 1 := by
refine summable_geometric_iff_norm_lt_one.mp ?_
simp_rw [← map_pow]
exact hsum.comp_injective <| Nat.pow_right_injective hp
open scoped Topology
open Nat Finset
section General
variable {R : Type*} [NormedCommRing R] [CompleteSpace R] {f : ℕ → R}
variable (hf₁ : f 1 = 1) (hmul : ∀ {m n}, Nat.Coprime m n → f (m * n) = f m * f n)
-- local instance to speed up typeclass search
@[local instance] private lemma instT0Space : T0Space R := MetricSpace.instT0Space
namespace EulerProduct
lemma summable_and_hasSum_factoredNumbers_prod_filter_prime_tsum
(hsum : ∀ {p : ℕ}, p.Prime → Summable (fun n : ℕ ↦ ‖f (p ^ n)‖)) (s : Finset ℕ) :
Summable (fun m : factoredNumbers s ↦ ‖f m‖) ∧
HasSum (fun m : factoredNumbers s ↦ f m)
(∏ p ∈ s.filter Nat.Prime, ∑' n : ℕ, f (p ^ n)) := by
induction' s using Finset.induction with p s hp ih
· rw [factoredNumbers_empty]
simp only [not_mem_empty, IsEmpty.forall_iff, forall_const, filter_true_of_mem, prod_empty]
exact ⟨(Set.finite_singleton 1).summable (‖f ·‖), hf₁ ▸ hasSum_singleton 1 f⟩
· rw [filter_insert]
split_ifs with hpp
· constructor
· simp only [← (equivProdNatFactoredNumbers hpp hp).summable_iff, Function.comp_def,
equivProdNatFactoredNumbers_apply', factoredNumbers.map_prime_pow_mul hmul hpp hp]
refine Summable.of_nonneg_of_le (fun _ ↦ norm_nonneg _) (fun _ ↦ norm_mul_le ..) ?_
apply Summable.mul_of_nonneg (hsum hpp) ih.1 <;> exact fun n ↦ norm_nonneg _
· have hp' : p ∉ s.filter Nat.Prime := mt (mem_of_mem_filter p) hp
rw [prod_insert hp', ← (equivProdNatFactoredNumbers hpp hp).hasSum_iff, Function.comp_def]
conv =>
enter [1, x]
rw [equivProdNatFactoredNumbers_apply', factoredNumbers.map_prime_pow_mul hmul hpp hp]
have : T3Space R := instT3Space -- speeds up the following
apply (hsum hpp).of_norm.hasSum.mul ih.2
-- `exact summable_mul_of_summable_norm (hsum hpp) ih.1` gives a time-out
apply summable_mul_of_summable_norm (hsum hpp) ih.1
· rwa [factoredNumbers_insert s hpp]
lemma prod_filter_prime_tsum_eq_tsum_factoredNumbers (hsum : Summable (‖f ·‖)) (s : Finset ℕ) :
∏ p ∈ s.filter Nat.Prime, ∑' n : ℕ, f (p ^ n) = ∑' m : factoredNumbers s, f m :=
(summable_and_hasSum_factoredNumbers_prod_filter_prime_tsum hf₁ hmul
(fun hp ↦ hsum.comp_injective <| Nat.pow_right_injective hp.one_lt) _).2.tsum_eq.symm
lemma norm_tsum_factoredNumbers_sub_tsum_lt (hsum : Summable f) (hf₀ : f 0 = 0) {ε : ℝ}
(εpos : 0 < ε) :
∃ N : ℕ, ∀ s : Finset ℕ, primesBelow N ≤ s →
‖(∑' m : ℕ, f m) - ∑' m : factoredNumbers s, f m‖ < ε := by
obtain ⟨N, hN⟩ :=
summable_iff_nat_tsum_vanishing.mp hsum (Metric.ball 0 ε) <| Metric.ball_mem_nhds 0 εpos
simp_rw [mem_ball_zero_iff] at hN
refine ⟨N, fun s hs ↦ ?_⟩
have := hN _ <| factoredNumbers_compl hs
rwa [← tsum_subtype_add_tsum_subtype_compl hsum (factoredNumbers s),
add_sub_cancel_left, tsum_eq_tsum_diff_singleton (factoredNumbers s)ᶜ hf₀]
-- Versions of the three lemmas above for `smoothNumbers N`
lemma summable_and_hasSum_smoothNumbers_prod_primesBelow_tsum
(hsum : ∀ {p : ℕ}, p.Prime → Summable (fun n : ℕ ↦ ‖f (p ^ n)‖)) (N : ℕ) :
Summable (fun m : N.smoothNumbers ↦ ‖f m‖) ∧
HasSum (fun m : N.smoothNumbers ↦ f m) (∏ p ∈ N.primesBelow, ∑' n : ℕ, f (p ^ n)) := by
rw [smoothNumbers_eq_factoredNumbers, primesBelow]
exact summable_and_hasSum_factoredNumbers_prod_filter_prime_tsum hf₁ hmul hsum _
lemma prod_primesBelow_tsum_eq_tsum_smoothNumbers (hsum : Summable (‖f ·‖)) (N : ℕ) :
∏ p ∈ N.primesBelow, ∑' n : ℕ, f (p ^ n) = ∑' m : N.smoothNumbers, f m :=
(summable_and_hasSum_smoothNumbers_prod_primesBelow_tsum hf₁ hmul
(fun hp ↦ hsum.comp_injective <| Nat.pow_right_injective hp.one_lt) _).2.tsum_eq.symm
lemma norm_tsum_smoothNumbers_sub_tsum_lt (hsum : Summable f) (hf₀ : f 0 = 0)
{ε : ℝ} (εpos : 0 < ε) :
∃ N₀ : ℕ, ∀ N ≥ N₀, ‖(∑' m : ℕ, f m) - ∑' m : N.smoothNumbers, f m‖ < ε := by
conv => enter [1, N₀, N]; rw [smoothNumbers_eq_factoredNumbers]
obtain ⟨N₀, hN₀⟩ := norm_tsum_factoredNumbers_sub_tsum_lt hsum hf₀ εpos
refine ⟨N₀, fun N hN ↦ hN₀ (range N) fun p hp ↦ ?_⟩
exact mem_range.mpr <| (lt_of_mem_primesBelow hp).trans_le hN
theorem eulerProduct_hasProd (hsum : Summable (‖f ·‖)) (hf₀ : f 0 = 0) :
HasProd (fun p : Primes ↦ ∑' e, f (p ^ e)) (∑' n, f n) := by
let F : ℕ → R := fun n ↦ ∑' e, f (n ^ e)
change HasProd (F ∘ Subtype.val) _
rw [hasProd_subtype_iff_mulIndicator,
show Set.mulIndicator (fun p : ℕ ↦ Irreducible p) = {p | Nat.Prime p}.mulIndicator from rfl,
HasProd, Metric.tendsto_atTop]
intro ε hε
obtain ⟨N₀, hN₀⟩ := norm_tsum_factoredNumbers_sub_tsum_lt hsum.of_norm hf₀ hε
refine ⟨range N₀, fun s hs ↦ ?_⟩
have : ∏ p ∈ s, {p | Nat.Prime p}.mulIndicator F p = ∏ p ∈ s.filter Nat.Prime, F p :=
prod_mulIndicator_eq_prod_filter s (fun _ ↦ F) _ id
rw [this, dist_eq_norm, prod_filter_prime_tsum_eq_tsum_factoredNumbers hf₁ hmul hsum,
norm_sub_rev]
exact hN₀ s fun p hp ↦ hs <| mem_range.mpr <| lt_of_mem_primesBelow hp
| Mathlib/NumberTheory/EulerProduct/Basic.lean | 182 | 185 | theorem eulerProduct_hasProd_mulIndicator (hsum : Summable (‖f ·‖)) (hf₀ : f 0 = 0) :
HasProd (Set.mulIndicator {p | Nat.Prime p} fun p ↦ ∑' e, f (p ^ e)) (∑' n, f n) := by |
rw [← hasProd_subtype_iff_mulIndicator]
exact eulerProduct_hasProd hf₁ hmul hsum hf₀
|
import Mathlib.Analysis.SpecialFunctions.Pow.Asymptotics
import Mathlib.NumberTheory.Liouville.Basic
import Mathlib.Topology.Instances.Irrational
#align_import number_theory.liouville.liouville_with from "leanprover-community/mathlib"@"0b9eaaa7686280fad8cce467f5c3c57ee6ce77f8"
open Filter Metric Real Set
open scoped Filter Topology
def LiouvilleWith (p x : ℝ) : Prop :=
∃ C, ∃ᶠ n : ℕ in atTop, ∃ m : ℤ, x ≠ m / n ∧ |x - m / n| < C / n ^ p
#align liouville_with LiouvilleWith
theorem liouvilleWith_one (x : ℝ) : LiouvilleWith 1 x := by
use 2
refine ((eventually_gt_atTop 0).mono fun n hn => ?_).frequently
have hn' : (0 : ℝ) < n := by simpa
have : x < ↑(⌊x * ↑n⌋ + 1) / ↑n := by
rw [lt_div_iff hn', Int.cast_add, Int.cast_one];
exact Int.lt_floor_add_one _
refine ⟨⌊x * n⌋ + 1, this.ne, ?_⟩
rw [abs_sub_comm, abs_of_pos (sub_pos.2 this), rpow_one, sub_lt_iff_lt_add',
add_div_eq_mul_add_div _ _ hn'.ne']
gcongr
calc _ ≤ x * n + 1 := by push_cast; gcongr; apply Int.floor_le
_ < x * n + 2 := by linarith
#align liouville_with_one liouvilleWith_one
namespace LiouvilleWith
variable {p q x y : ℝ} {r : ℚ} {m : ℤ} {n : ℕ}
theorem exists_pos (h : LiouvilleWith p x) :
∃ (C : ℝ) (_h₀ : 0 < C),
∃ᶠ n : ℕ in atTop, 1 ≤ n ∧ ∃ m : ℤ, x ≠ m / n ∧ |x - m / n| < C / n ^ p := by
rcases h with ⟨C, hC⟩
refine ⟨max C 1, zero_lt_one.trans_le <| le_max_right _ _, ?_⟩
refine ((eventually_ge_atTop 1).and_frequently hC).mono ?_
rintro n ⟨hle, m, hne, hlt⟩
refine ⟨hle, m, hne, hlt.trans_le ?_⟩
gcongr
apply le_max_left
#align liouville_with.exists_pos LiouvilleWith.exists_pos
theorem mono (h : LiouvilleWith p x) (hle : q ≤ p) : LiouvilleWith q x := by
rcases h.exists_pos with ⟨C, hC₀, hC⟩
refine ⟨C, hC.mono ?_⟩; rintro n ⟨hn, m, hne, hlt⟩
refine ⟨m, hne, hlt.trans_le <| ?_⟩
gcongr
exact_mod_cast hn
#align liouville_with.mono LiouvilleWith.mono
theorem frequently_lt_rpow_neg (h : LiouvilleWith p x) (hlt : q < p) :
∃ᶠ n : ℕ in atTop, ∃ m : ℤ, x ≠ m / n ∧ |x - m / n| < n ^ (-q) := by
rcases h.exists_pos with ⟨C, _hC₀, hC⟩
have : ∀ᶠ n : ℕ in atTop, C < n ^ (p - q) := by
simpa only [(· ∘ ·), neg_sub, one_div] using
((tendsto_rpow_atTop (sub_pos.2 hlt)).comp tendsto_natCast_atTop_atTop).eventually
(eventually_gt_atTop C)
refine (this.and_frequently hC).mono ?_
rintro n ⟨hnC, hn, m, hne, hlt⟩
replace hn : (0 : ℝ) < n := Nat.cast_pos.2 hn
refine ⟨m, hne, hlt.trans <| (div_lt_iff <| rpow_pos_of_pos hn _).2 ?_⟩
rwa [mul_comm, ← rpow_add hn, ← sub_eq_add_neg]
#align liouville_with.frequently_lt_rpow_neg LiouvilleWith.frequently_lt_rpow_neg
theorem mul_rat (h : LiouvilleWith p x) (hr : r ≠ 0) : LiouvilleWith p (x * r) := by
rcases h.exists_pos with ⟨C, _hC₀, hC⟩
refine ⟨r.den ^ p * (|r| * C), (tendsto_id.nsmul_atTop r.pos).frequently (hC.mono ?_)⟩
rintro n ⟨_hn, m, hne, hlt⟩
have A : (↑(r.num * m) : ℝ) / ↑(r.den • id n) = m / n * r := by
simp [← div_mul_div_comm, ← r.cast_def, mul_comm]
refine ⟨r.num * m, ?_, ?_⟩
· rw [A]; simp [hne, hr]
· rw [A, ← sub_mul, abs_mul]
simp only [smul_eq_mul, id, Nat.cast_mul]
calc _ < C / ↑n ^ p * |↑r| := by gcongr
_ = ↑r.den ^ p * (↑|r| * C) / (↑r.den * ↑n) ^ p := ?_
rw [mul_rpow, mul_div_mul_left, mul_comm, mul_div_assoc]
· simp only [Rat.cast_abs, le_refl]
all_goals positivity
#align liouville_with.mul_rat LiouvilleWith.mul_rat
theorem mul_rat_iff (hr : r ≠ 0) : LiouvilleWith p (x * r) ↔ LiouvilleWith p x :=
⟨fun h => by
simpa only [mul_assoc, ← Rat.cast_mul, mul_inv_cancel hr, Rat.cast_one, mul_one] using
h.mul_rat (inv_ne_zero hr),
fun h => h.mul_rat hr⟩
#align liouville_with.mul_rat_iff LiouvilleWith.mul_rat_iff
| Mathlib/NumberTheory/Liouville/LiouvilleWith.lean | 142 | 143 | theorem rat_mul_iff (hr : r ≠ 0) : LiouvilleWith p (r * x) ↔ LiouvilleWith p x := by |
rw [mul_comm, mul_rat_iff hr]
|
import Mathlib.Topology.Constructions
#align_import topology.continuous_on from "leanprover-community/mathlib"@"d4f691b9e5f94cfc64639973f3544c95f8d5d494"
open Set Filter Function Topology Filter
variable {α : Type*} {β : Type*} {γ : Type*} {δ : Type*}
variable [TopologicalSpace α]
@[simp]
theorem nhds_bind_nhdsWithin {a : α} {s : Set α} : ((𝓝 a).bind fun x => 𝓝[s] x) = 𝓝[s] a :=
bind_inf_principal.trans <| congr_arg₂ _ nhds_bind_nhds rfl
#align nhds_bind_nhds_within nhds_bind_nhdsWithin
@[simp]
theorem eventually_nhds_nhdsWithin {a : α} {s : Set α} {p : α → Prop} :
(∀ᶠ y in 𝓝 a, ∀ᶠ x in 𝓝[s] y, p x) ↔ ∀ᶠ x in 𝓝[s] a, p x :=
Filter.ext_iff.1 nhds_bind_nhdsWithin { x | p x }
#align eventually_nhds_nhds_within eventually_nhds_nhdsWithin
theorem eventually_nhdsWithin_iff {a : α} {s : Set α} {p : α → Prop} :
(∀ᶠ x in 𝓝[s] a, p x) ↔ ∀ᶠ x in 𝓝 a, x ∈ s → p x :=
eventually_inf_principal
#align eventually_nhds_within_iff eventually_nhdsWithin_iff
theorem frequently_nhdsWithin_iff {z : α} {s : Set α} {p : α → Prop} :
(∃ᶠ x in 𝓝[s] z, p x) ↔ ∃ᶠ x in 𝓝 z, p x ∧ x ∈ s :=
frequently_inf_principal.trans <| by simp only [and_comm]
#align frequently_nhds_within_iff frequently_nhdsWithin_iff
theorem mem_closure_ne_iff_frequently_within {z : α} {s : Set α} :
z ∈ closure (s \ {z}) ↔ ∃ᶠ x in 𝓝[≠] z, x ∈ s := by
simp [mem_closure_iff_frequently, frequently_nhdsWithin_iff]
#align mem_closure_ne_iff_frequently_within mem_closure_ne_iff_frequently_within
@[simp]
theorem eventually_nhdsWithin_nhdsWithin {a : α} {s : Set α} {p : α → Prop} :
(∀ᶠ y in 𝓝[s] a, ∀ᶠ x in 𝓝[s] y, p x) ↔ ∀ᶠ x in 𝓝[s] a, p x := by
refine ⟨fun h => ?_, fun h => (eventually_nhds_nhdsWithin.2 h).filter_mono inf_le_left⟩
simp only [eventually_nhdsWithin_iff] at h ⊢
exact h.mono fun x hx hxs => (hx hxs).self_of_nhds hxs
#align eventually_nhds_within_nhds_within eventually_nhdsWithin_nhdsWithin
theorem nhdsWithin_eq (a : α) (s : Set α) :
𝓝[s] a = ⨅ t ∈ { t : Set α | a ∈ t ∧ IsOpen t }, 𝓟 (t ∩ s) :=
((nhds_basis_opens a).inf_principal s).eq_biInf
#align nhds_within_eq nhdsWithin_eq
theorem nhdsWithin_univ (a : α) : 𝓝[Set.univ] a = 𝓝 a := by
rw [nhdsWithin, principal_univ, inf_top_eq]
#align nhds_within_univ nhdsWithin_univ
theorem nhdsWithin_hasBasis {p : β → Prop} {s : β → Set α} {a : α} (h : (𝓝 a).HasBasis p s)
(t : Set α) : (𝓝[t] a).HasBasis p fun i => s i ∩ t :=
h.inf_principal t
#align nhds_within_has_basis nhdsWithin_hasBasis
theorem nhdsWithin_basis_open (a : α) (t : Set α) :
(𝓝[t] a).HasBasis (fun u => a ∈ u ∧ IsOpen u) fun u => u ∩ t :=
nhdsWithin_hasBasis (nhds_basis_opens a) t
#align nhds_within_basis_open nhdsWithin_basis_open
theorem mem_nhdsWithin {t : Set α} {a : α} {s : Set α} :
t ∈ 𝓝[s] a ↔ ∃ u, IsOpen u ∧ a ∈ u ∧ u ∩ s ⊆ t := by
simpa only [and_assoc, and_left_comm] using (nhdsWithin_basis_open a s).mem_iff
#align mem_nhds_within mem_nhdsWithin
theorem mem_nhdsWithin_iff_exists_mem_nhds_inter {t : Set α} {a : α} {s : Set α} :
t ∈ 𝓝[s] a ↔ ∃ u ∈ 𝓝 a, u ∩ s ⊆ t :=
(nhdsWithin_hasBasis (𝓝 a).basis_sets s).mem_iff
#align mem_nhds_within_iff_exists_mem_nhds_inter mem_nhdsWithin_iff_exists_mem_nhds_inter
theorem diff_mem_nhdsWithin_compl {x : α} {s : Set α} (hs : s ∈ 𝓝 x) (t : Set α) :
s \ t ∈ 𝓝[tᶜ] x :=
diff_mem_inf_principal_compl hs t
#align diff_mem_nhds_within_compl diff_mem_nhdsWithin_compl
theorem diff_mem_nhdsWithin_diff {x : α} {s t : Set α} (hs : s ∈ 𝓝[t] x) (t' : Set α) :
s \ t' ∈ 𝓝[t \ t'] x := by
rw [nhdsWithin, diff_eq, diff_eq, ← inf_principal, ← inf_assoc]
exact inter_mem_inf hs (mem_principal_self _)
#align diff_mem_nhds_within_diff diff_mem_nhdsWithin_diff
theorem nhds_of_nhdsWithin_of_nhds {s t : Set α} {a : α} (h1 : s ∈ 𝓝 a) (h2 : t ∈ 𝓝[s] a) :
t ∈ 𝓝 a := by
rcases mem_nhdsWithin_iff_exists_mem_nhds_inter.mp h2 with ⟨_, Hw, hw⟩
exact (𝓝 a).sets_of_superset ((𝓝 a).inter_sets Hw h1) hw
#align nhds_of_nhds_within_of_nhds nhds_of_nhdsWithin_of_nhds
theorem mem_nhdsWithin_iff_eventually {s t : Set α} {x : α} :
t ∈ 𝓝[s] x ↔ ∀ᶠ y in 𝓝 x, y ∈ s → y ∈ t :=
eventually_inf_principal
#align mem_nhds_within_iff_eventually mem_nhdsWithin_iff_eventually
theorem mem_nhdsWithin_iff_eventuallyEq {s t : Set α} {x : α} :
t ∈ 𝓝[s] x ↔ s =ᶠ[𝓝 x] (s ∩ t : Set α) := by
simp_rw [mem_nhdsWithin_iff_eventually, eventuallyEq_set, mem_inter_iff, iff_self_and]
#align mem_nhds_within_iff_eventually_eq mem_nhdsWithin_iff_eventuallyEq
theorem nhdsWithin_eq_iff_eventuallyEq {s t : Set α} {x : α} : 𝓝[s] x = 𝓝[t] x ↔ s =ᶠ[𝓝 x] t :=
set_eventuallyEq_iff_inf_principal.symm
#align nhds_within_eq_iff_eventually_eq nhdsWithin_eq_iff_eventuallyEq
theorem nhdsWithin_le_iff {s t : Set α} {x : α} : 𝓝[s] x ≤ 𝓝[t] x ↔ t ∈ 𝓝[s] x :=
set_eventuallyLE_iff_inf_principal_le.symm.trans set_eventuallyLE_iff_mem_inf_principal
#align nhds_within_le_iff nhdsWithin_le_iff
-- Porting note: golfed, dropped an unneeded assumption
theorem preimage_nhdsWithin_coinduced' {π : α → β} {s : Set β} {t : Set α} {a : α} (h : a ∈ t)
(hs : s ∈ @nhds β (.coinduced (fun x : t => π x) inferInstance) (π a)) :
π ⁻¹' s ∈ 𝓝[t] a := by
lift a to t using h
replace hs : (fun x : t => π x) ⁻¹' s ∈ 𝓝 a := preimage_nhds_coinduced hs
rwa [← map_nhds_subtype_val, mem_map]
#align preimage_nhds_within_coinduced' preimage_nhdsWithin_coinduced'ₓ
theorem mem_nhdsWithin_of_mem_nhds {s t : Set α} {a : α} (h : s ∈ 𝓝 a) : s ∈ 𝓝[t] a :=
mem_inf_of_left h
#align mem_nhds_within_of_mem_nhds mem_nhdsWithin_of_mem_nhds
theorem self_mem_nhdsWithin {a : α} {s : Set α} : s ∈ 𝓝[s] a :=
mem_inf_of_right (mem_principal_self s)
#align self_mem_nhds_within self_mem_nhdsWithin
theorem eventually_mem_nhdsWithin {a : α} {s : Set α} : ∀ᶠ x in 𝓝[s] a, x ∈ s :=
self_mem_nhdsWithin
#align eventually_mem_nhds_within eventually_mem_nhdsWithin
theorem inter_mem_nhdsWithin (s : Set α) {t : Set α} {a : α} (h : t ∈ 𝓝 a) : s ∩ t ∈ 𝓝[s] a :=
inter_mem self_mem_nhdsWithin (mem_inf_of_left h)
#align inter_mem_nhds_within inter_mem_nhdsWithin
theorem nhdsWithin_mono (a : α) {s t : Set α} (h : s ⊆ t) : 𝓝[s] a ≤ 𝓝[t] a :=
inf_le_inf_left _ (principal_mono.mpr h)
#align nhds_within_mono nhdsWithin_mono
theorem pure_le_nhdsWithin {a : α} {s : Set α} (ha : a ∈ s) : pure a ≤ 𝓝[s] a :=
le_inf (pure_le_nhds a) (le_principal_iff.2 ha)
#align pure_le_nhds_within pure_le_nhdsWithin
theorem mem_of_mem_nhdsWithin {a : α} {s t : Set α} (ha : a ∈ s) (ht : t ∈ 𝓝[s] a) : a ∈ t :=
pure_le_nhdsWithin ha ht
#align mem_of_mem_nhds_within mem_of_mem_nhdsWithin
theorem Filter.Eventually.self_of_nhdsWithin {p : α → Prop} {s : Set α} {x : α}
(h : ∀ᶠ y in 𝓝[s] x, p y) (hx : x ∈ s) : p x :=
mem_of_mem_nhdsWithin hx h
#align filter.eventually.self_of_nhds_within Filter.Eventually.self_of_nhdsWithin
theorem tendsto_const_nhdsWithin {l : Filter β} {s : Set α} {a : α} (ha : a ∈ s) :
Tendsto (fun _ : β => a) l (𝓝[s] a) :=
tendsto_const_pure.mono_right <| pure_le_nhdsWithin ha
#align tendsto_const_nhds_within tendsto_const_nhdsWithin
theorem nhdsWithin_restrict'' {a : α} (s : Set α) {t : Set α} (h : t ∈ 𝓝[s] a) :
𝓝[s] a = 𝓝[s ∩ t] a :=
le_antisymm (le_inf inf_le_left (le_principal_iff.mpr (inter_mem self_mem_nhdsWithin h)))
(inf_le_inf_left _ (principal_mono.mpr Set.inter_subset_left))
#align nhds_within_restrict'' nhdsWithin_restrict''
theorem nhdsWithin_restrict' {a : α} (s : Set α) {t : Set α} (h : t ∈ 𝓝 a) : 𝓝[s] a = 𝓝[s ∩ t] a :=
nhdsWithin_restrict'' s <| mem_inf_of_left h
#align nhds_within_restrict' nhdsWithin_restrict'
theorem nhdsWithin_restrict {a : α} (s : Set α) {t : Set α} (h₀ : a ∈ t) (h₁ : IsOpen t) :
𝓝[s] a = 𝓝[s ∩ t] a :=
nhdsWithin_restrict' s (IsOpen.mem_nhds h₁ h₀)
#align nhds_within_restrict nhdsWithin_restrict
theorem nhdsWithin_le_of_mem {a : α} {s t : Set α} (h : s ∈ 𝓝[t] a) : 𝓝[t] a ≤ 𝓝[s] a :=
nhdsWithin_le_iff.mpr h
#align nhds_within_le_of_mem nhdsWithin_le_of_mem
theorem nhdsWithin_le_nhds {a : α} {s : Set α} : 𝓝[s] a ≤ 𝓝 a := by
rw [← nhdsWithin_univ]
apply nhdsWithin_le_of_mem
exact univ_mem
#align nhds_within_le_nhds nhdsWithin_le_nhds
theorem nhdsWithin_eq_nhdsWithin' {a : α} {s t u : Set α} (hs : s ∈ 𝓝 a) (h₂ : t ∩ s = u ∩ s) :
𝓝[t] a = 𝓝[u] a := by rw [nhdsWithin_restrict' t hs, nhdsWithin_restrict' u hs, h₂]
#align nhds_within_eq_nhds_within' nhdsWithin_eq_nhdsWithin'
theorem nhdsWithin_eq_nhdsWithin {a : α} {s t u : Set α} (h₀ : a ∈ s) (h₁ : IsOpen s)
(h₂ : t ∩ s = u ∩ s) : 𝓝[t] a = 𝓝[u] a := by
rw [nhdsWithin_restrict t h₀ h₁, nhdsWithin_restrict u h₀ h₁, h₂]
#align nhds_within_eq_nhds_within nhdsWithin_eq_nhdsWithin
@[simp] theorem nhdsWithin_eq_nhds {a : α} {s : Set α} : 𝓝[s] a = 𝓝 a ↔ s ∈ 𝓝 a :=
inf_eq_left.trans le_principal_iff
#align nhds_within_eq_nhds nhdsWithin_eq_nhds
theorem IsOpen.nhdsWithin_eq {a : α} {s : Set α} (h : IsOpen s) (ha : a ∈ s) : 𝓝[s] a = 𝓝 a :=
nhdsWithin_eq_nhds.2 <| h.mem_nhds ha
#align is_open.nhds_within_eq IsOpen.nhdsWithin_eq
theorem preimage_nhds_within_coinduced {π : α → β} {s : Set β} {t : Set α} {a : α} (h : a ∈ t)
(ht : IsOpen t)
(hs : s ∈ @nhds β (.coinduced (fun x : t => π x) inferInstance) (π a)) :
π ⁻¹' s ∈ 𝓝 a := by
rw [← ht.nhdsWithin_eq h]
exact preimage_nhdsWithin_coinduced' h hs
#align preimage_nhds_within_coinduced preimage_nhds_within_coinduced
@[simp]
theorem nhdsWithin_empty (a : α) : 𝓝[∅] a = ⊥ := by rw [nhdsWithin, principal_empty, inf_bot_eq]
#align nhds_within_empty nhdsWithin_empty
theorem nhdsWithin_union (a : α) (s t : Set α) : 𝓝[s ∪ t] a = 𝓝[s] a ⊔ 𝓝[t] a := by
delta nhdsWithin
rw [← inf_sup_left, sup_principal]
#align nhds_within_union nhdsWithin_union
theorem nhdsWithin_biUnion {ι} {I : Set ι} (hI : I.Finite) (s : ι → Set α) (a : α) :
𝓝[⋃ i ∈ I, s i] a = ⨆ i ∈ I, 𝓝[s i] a :=
Set.Finite.induction_on hI (by simp) fun _ _ hT ↦ by
simp only [hT, nhdsWithin_union, iSup_insert, biUnion_insert]
#align nhds_within_bUnion nhdsWithin_biUnion
theorem nhdsWithin_sUnion {S : Set (Set α)} (hS : S.Finite) (a : α) :
𝓝[⋃₀ S] a = ⨆ s ∈ S, 𝓝[s] a := by
rw [sUnion_eq_biUnion, nhdsWithin_biUnion hS]
#align nhds_within_sUnion nhdsWithin_sUnion
theorem nhdsWithin_iUnion {ι} [Finite ι] (s : ι → Set α) (a : α) :
𝓝[⋃ i, s i] a = ⨆ i, 𝓝[s i] a := by
rw [← sUnion_range, nhdsWithin_sUnion (finite_range s), iSup_range]
#align nhds_within_Union nhdsWithin_iUnion
theorem nhdsWithin_inter (a : α) (s t : Set α) : 𝓝[s ∩ t] a = 𝓝[s] a ⊓ 𝓝[t] a := by
delta nhdsWithin
rw [inf_left_comm, inf_assoc, inf_principal, ← inf_assoc, inf_idem]
#align nhds_within_inter nhdsWithin_inter
theorem nhdsWithin_inter' (a : α) (s t : Set α) : 𝓝[s ∩ t] a = 𝓝[s] a ⊓ 𝓟 t := by
delta nhdsWithin
rw [← inf_principal, inf_assoc]
#align nhds_within_inter' nhdsWithin_inter'
theorem nhdsWithin_inter_of_mem {a : α} {s t : Set α} (h : s ∈ 𝓝[t] a) : 𝓝[s ∩ t] a = 𝓝[t] a := by
rw [nhdsWithin_inter, inf_eq_right]
exact nhdsWithin_le_of_mem h
#align nhds_within_inter_of_mem nhdsWithin_inter_of_mem
theorem nhdsWithin_inter_of_mem' {a : α} {s t : Set α} (h : t ∈ 𝓝[s] a) : 𝓝[s ∩ t] a = 𝓝[s] a := by
rw [inter_comm, nhdsWithin_inter_of_mem h]
#align nhds_within_inter_of_mem' nhdsWithin_inter_of_mem'
@[simp]
theorem nhdsWithin_singleton (a : α) : 𝓝[{a}] a = pure a := by
rw [nhdsWithin, principal_singleton, inf_eq_right.2 (pure_le_nhds a)]
#align nhds_within_singleton nhdsWithin_singleton
@[simp]
theorem nhdsWithin_insert (a : α) (s : Set α) : 𝓝[insert a s] a = pure a ⊔ 𝓝[s] a := by
rw [← singleton_union, nhdsWithin_union, nhdsWithin_singleton]
#align nhds_within_insert nhdsWithin_insert
theorem mem_nhdsWithin_insert {a : α} {s t : Set α} : t ∈ 𝓝[insert a s] a ↔ a ∈ t ∧ t ∈ 𝓝[s] a := by
simp
#align mem_nhds_within_insert mem_nhdsWithin_insert
theorem insert_mem_nhdsWithin_insert {a : α} {s t : Set α} (h : t ∈ 𝓝[s] a) :
insert a t ∈ 𝓝[insert a s] a := by simp [mem_of_superset h]
#align insert_mem_nhds_within_insert insert_mem_nhdsWithin_insert
theorem insert_mem_nhds_iff {a : α} {s : Set α} : insert a s ∈ 𝓝 a ↔ s ∈ 𝓝[≠] a := by
simp only [nhdsWithin, mem_inf_principal, mem_compl_iff, mem_singleton_iff, or_iff_not_imp_left,
insert_def]
#align insert_mem_nhds_iff insert_mem_nhds_iff
@[simp]
theorem nhdsWithin_compl_singleton_sup_pure (a : α) : 𝓝[≠] a ⊔ pure a = 𝓝 a := by
rw [← nhdsWithin_singleton, ← nhdsWithin_union, compl_union_self, nhdsWithin_univ]
#align nhds_within_compl_singleton_sup_pure nhdsWithin_compl_singleton_sup_pure
theorem nhdsWithin_prod {α : Type*} [TopologicalSpace α] {β : Type*} [TopologicalSpace β]
{s u : Set α} {t v : Set β} {a : α} {b : β} (hu : u ∈ 𝓝[s] a) (hv : v ∈ 𝓝[t] b) :
u ×ˢ v ∈ 𝓝[s ×ˢ t] (a, b) := by
rw [nhdsWithin_prod_eq]
exact prod_mem_prod hu hv
#align nhds_within_prod nhdsWithin_prod
theorem nhdsWithin_pi_eq' {ι : Type*} {α : ι → Type*} [∀ i, TopologicalSpace (α i)] {I : Set ι}
(hI : I.Finite) (s : ∀ i, Set (α i)) (x : ∀ i, α i) :
𝓝[pi I s] x = ⨅ i, comap (fun x => x i) (𝓝 (x i) ⊓ ⨅ (_ : i ∈ I), 𝓟 (s i)) := by
simp only [nhdsWithin, nhds_pi, Filter.pi, comap_inf, comap_iInf, pi_def, comap_principal, ←
iInf_principal_finite hI, ← iInf_inf_eq]
#align nhds_within_pi_eq' nhdsWithin_pi_eq'
theorem nhdsWithin_pi_eq {ι : Type*} {α : ι → Type*} [∀ i, TopologicalSpace (α i)] {I : Set ι}
(hI : I.Finite) (s : ∀ i, Set (α i)) (x : ∀ i, α i) :
𝓝[pi I s] x =
(⨅ i ∈ I, comap (fun x => x i) (𝓝[s i] x i)) ⊓
⨅ (i) (_ : i ∉ I), comap (fun x => x i) (𝓝 (x i)) := by
simp only [nhdsWithin, nhds_pi, Filter.pi, pi_def, ← iInf_principal_finite hI, comap_inf,
comap_principal, eval]
rw [iInf_split _ fun i => i ∈ I, inf_right_comm]
simp only [iInf_inf_eq]
#align nhds_within_pi_eq nhdsWithin_pi_eq
theorem nhdsWithin_pi_univ_eq {ι : Type*} {α : ι → Type*} [Finite ι] [∀ i, TopologicalSpace (α i)]
(s : ∀ i, Set (α i)) (x : ∀ i, α i) :
𝓝[pi univ s] x = ⨅ i, comap (fun x => x i) (𝓝[s i] x i) := by
simpa [nhdsWithin] using nhdsWithin_pi_eq finite_univ s x
#align nhds_within_pi_univ_eq nhdsWithin_pi_univ_eq
theorem nhdsWithin_pi_eq_bot {ι : Type*} {α : ι → Type*} [∀ i, TopologicalSpace (α i)] {I : Set ι}
{s : ∀ i, Set (α i)} {x : ∀ i, α i} : 𝓝[pi I s] x = ⊥ ↔ ∃ i ∈ I, 𝓝[s i] x i = ⊥ := by
simp only [nhdsWithin, nhds_pi, pi_inf_principal_pi_eq_bot]
#align nhds_within_pi_eq_bot nhdsWithin_pi_eq_bot
theorem nhdsWithin_pi_neBot {ι : Type*} {α : ι → Type*} [∀ i, TopologicalSpace (α i)] {I : Set ι}
{s : ∀ i, Set (α i)} {x : ∀ i, α i} : (𝓝[pi I s] x).NeBot ↔ ∀ i ∈ I, (𝓝[s i] x i).NeBot := by
simp [neBot_iff, nhdsWithin_pi_eq_bot]
#align nhds_within_pi_ne_bot nhdsWithin_pi_neBot
theorem Filter.Tendsto.piecewise_nhdsWithin {f g : α → β} {t : Set α} [∀ x, Decidable (x ∈ t)]
{a : α} {s : Set α} {l : Filter β} (h₀ : Tendsto f (𝓝[s ∩ t] a) l)
(h₁ : Tendsto g (𝓝[s ∩ tᶜ] a) l) : Tendsto (piecewise t f g) (𝓝[s] a) l := by
apply Tendsto.piecewise <;> rwa [← nhdsWithin_inter']
#align filter.tendsto.piecewise_nhds_within Filter.Tendsto.piecewise_nhdsWithin
theorem Filter.Tendsto.if_nhdsWithin {f g : α → β} {p : α → Prop} [DecidablePred p] {a : α}
{s : Set α} {l : Filter β} (h₀ : Tendsto f (𝓝[s ∩ { x | p x }] a) l)
(h₁ : Tendsto g (𝓝[s ∩ { x | ¬p x }] a) l) :
Tendsto (fun x => if p x then f x else g x) (𝓝[s] a) l :=
h₀.piecewise_nhdsWithin h₁
#align filter.tendsto.if_nhds_within Filter.Tendsto.if_nhdsWithin
theorem map_nhdsWithin (f : α → β) (a : α) (s : Set α) :
map f (𝓝[s] a) = ⨅ t ∈ { t : Set α | a ∈ t ∧ IsOpen t }, 𝓟 (f '' (t ∩ s)) :=
((nhdsWithin_basis_open a s).map f).eq_biInf
#align map_nhds_within map_nhdsWithin
theorem tendsto_nhdsWithin_mono_left {f : α → β} {a : α} {s t : Set α} {l : Filter β} (hst : s ⊆ t)
(h : Tendsto f (𝓝[t] a) l) : Tendsto f (𝓝[s] a) l :=
h.mono_left <| nhdsWithin_mono a hst
#align tendsto_nhds_within_mono_left tendsto_nhdsWithin_mono_left
theorem tendsto_nhdsWithin_mono_right {f : β → α} {l : Filter β} {a : α} {s t : Set α} (hst : s ⊆ t)
(h : Tendsto f l (𝓝[s] a)) : Tendsto f l (𝓝[t] a) :=
h.mono_right (nhdsWithin_mono a hst)
#align tendsto_nhds_within_mono_right tendsto_nhdsWithin_mono_right
theorem tendsto_nhdsWithin_of_tendsto_nhds {f : α → β} {a : α} {s : Set α} {l : Filter β}
(h : Tendsto f (𝓝 a) l) : Tendsto f (𝓝[s] a) l :=
h.mono_left inf_le_left
#align tendsto_nhds_within_of_tendsto_nhds tendsto_nhdsWithin_of_tendsto_nhds
theorem eventually_mem_of_tendsto_nhdsWithin {f : β → α} {a : α} {s : Set α} {l : Filter β}
(h : Tendsto f l (𝓝[s] a)) : ∀ᶠ i in l, f i ∈ s := by
simp_rw [nhdsWithin_eq, tendsto_iInf, mem_setOf_eq, tendsto_principal, mem_inter_iff,
eventually_and] at h
exact (h univ ⟨mem_univ a, isOpen_univ⟩).2
#align eventually_mem_of_tendsto_nhds_within eventually_mem_of_tendsto_nhdsWithin
theorem tendsto_nhds_of_tendsto_nhdsWithin {f : β → α} {a : α} {s : Set α} {l : Filter β}
(h : Tendsto f l (𝓝[s] a)) : Tendsto f l (𝓝 a) :=
h.mono_right nhdsWithin_le_nhds
#align tendsto_nhds_of_tendsto_nhds_within tendsto_nhds_of_tendsto_nhdsWithin
theorem nhdsWithin_neBot_of_mem {s : Set α} {x : α} (hx : x ∈ s) : NeBot (𝓝[s] x) :=
mem_closure_iff_nhdsWithin_neBot.1 <| subset_closure hx
#align nhds_within_ne_bot_of_mem nhdsWithin_neBot_of_mem
theorem IsClosed.mem_of_nhdsWithin_neBot {s : Set α} (hs : IsClosed s) {x : α}
(hx : NeBot <| 𝓝[s] x) : x ∈ s :=
hs.closure_eq ▸ mem_closure_iff_nhdsWithin_neBot.2 hx
#align is_closed.mem_of_nhds_within_ne_bot IsClosed.mem_of_nhdsWithin_neBot
theorem DenseRange.nhdsWithin_neBot {ι : Type*} {f : ι → α} (h : DenseRange f) (x : α) :
NeBot (𝓝[range f] x) :=
mem_closure_iff_clusterPt.1 (h x)
#align dense_range.nhds_within_ne_bot DenseRange.nhdsWithin_neBot
theorem mem_closure_pi {ι : Type*} {α : ι → Type*} [∀ i, TopologicalSpace (α i)] {I : Set ι}
{s : ∀ i, Set (α i)} {x : ∀ i, α i} : x ∈ closure (pi I s) ↔ ∀ i ∈ I, x i ∈ closure (s i) := by
simp only [mem_closure_iff_nhdsWithin_neBot, nhdsWithin_pi_neBot]
#align mem_closure_pi mem_closure_pi
theorem closure_pi_set {ι : Type*} {α : ι → Type*} [∀ i, TopologicalSpace (α i)] (I : Set ι)
(s : ∀ i, Set (α i)) : closure (pi I s) = pi I fun i => closure (s i) :=
Set.ext fun _ => mem_closure_pi
#align closure_pi_set closure_pi_set
theorem dense_pi {ι : Type*} {α : ι → Type*} [∀ i, TopologicalSpace (α i)] {s : ∀ i, Set (α i)}
(I : Set ι) (hs : ∀ i ∈ I, Dense (s i)) : Dense (pi I s) := by
simp only [dense_iff_closure_eq, closure_pi_set, pi_congr rfl fun i hi => (hs i hi).closure_eq,
pi_univ]
#align dense_pi dense_pi
theorem eventuallyEq_nhdsWithin_iff {f g : α → β} {s : Set α} {a : α} :
f =ᶠ[𝓝[s] a] g ↔ ∀ᶠ x in 𝓝 a, x ∈ s → f x = g x :=
mem_inf_principal
#align eventually_eq_nhds_within_iff eventuallyEq_nhdsWithin_iff
theorem eventuallyEq_nhdsWithin_of_eqOn {f g : α → β} {s : Set α} {a : α} (h : EqOn f g s) :
f =ᶠ[𝓝[s] a] g :=
mem_inf_of_right h
#align eventually_eq_nhds_within_of_eq_on eventuallyEq_nhdsWithin_of_eqOn
theorem Set.EqOn.eventuallyEq_nhdsWithin {f g : α → β} {s : Set α} {a : α} (h : EqOn f g s) :
f =ᶠ[𝓝[s] a] g :=
eventuallyEq_nhdsWithin_of_eqOn h
#align set.eq_on.eventually_eq_nhds_within Set.EqOn.eventuallyEq_nhdsWithin
theorem tendsto_nhdsWithin_congr {f g : α → β} {s : Set α} {a : α} {l : Filter β}
(hfg : ∀ x ∈ s, f x = g x) (hf : Tendsto f (𝓝[s] a) l) : Tendsto g (𝓝[s] a) l :=
(tendsto_congr' <| eventuallyEq_nhdsWithin_of_eqOn hfg).1 hf
#align tendsto_nhds_within_congr tendsto_nhdsWithin_congr
theorem eventually_nhdsWithin_of_forall {s : Set α} {a : α} {p : α → Prop} (h : ∀ x ∈ s, p x) :
∀ᶠ x in 𝓝[s] a, p x :=
mem_inf_of_right h
#align eventually_nhds_within_of_forall eventually_nhdsWithin_of_forall
theorem tendsto_nhdsWithin_of_tendsto_nhds_of_eventually_within {a : α} {l : Filter β} {s : Set α}
(f : β → α) (h1 : Tendsto f l (𝓝 a)) (h2 : ∀ᶠ x in l, f x ∈ s) : Tendsto f l (𝓝[s] a) :=
tendsto_inf.2 ⟨h1, tendsto_principal.2 h2⟩
#align tendsto_nhds_within_of_tendsto_nhds_of_eventually_within tendsto_nhdsWithin_of_tendsto_nhds_of_eventually_within
theorem tendsto_nhdsWithin_iff {a : α} {l : Filter β} {s : Set α} {f : β → α} :
Tendsto f l (𝓝[s] a) ↔ Tendsto f l (𝓝 a) ∧ ∀ᶠ n in l, f n ∈ s :=
⟨fun h => ⟨tendsto_nhds_of_tendsto_nhdsWithin h, eventually_mem_of_tendsto_nhdsWithin h⟩, fun h =>
tendsto_nhdsWithin_of_tendsto_nhds_of_eventually_within _ h.1 h.2⟩
#align tendsto_nhds_within_iff tendsto_nhdsWithin_iff
@[simp]
theorem tendsto_nhdsWithin_range {a : α} {l : Filter β} {f : β → α} :
Tendsto f l (𝓝[range f] a) ↔ Tendsto f l (𝓝 a) :=
⟨fun h => h.mono_right inf_le_left, fun h =>
tendsto_inf.2 ⟨h, tendsto_principal.2 <| eventually_of_forall mem_range_self⟩⟩
#align tendsto_nhds_within_range tendsto_nhdsWithin_range
theorem Filter.EventuallyEq.eq_of_nhdsWithin {s : Set α} {f g : α → β} {a : α} (h : f =ᶠ[𝓝[s] a] g)
(hmem : a ∈ s) : f a = g a :=
h.self_of_nhdsWithin hmem
#align filter.eventually_eq.eq_of_nhds_within Filter.EventuallyEq.eq_of_nhdsWithin
theorem eventually_nhdsWithin_of_eventually_nhds {α : Type*} [TopologicalSpace α] {s : Set α}
{a : α} {p : α → Prop} (h : ∀ᶠ x in 𝓝 a, p x) : ∀ᶠ x in 𝓝[s] a, p x :=
mem_nhdsWithin_of_mem_nhds h
#align eventually_nhds_within_of_eventually_nhds eventually_nhdsWithin_of_eventually_nhds
theorem mem_nhdsWithin_subtype {s : Set α} {a : { x // x ∈ s }} {t u : Set { x // x ∈ s }} :
t ∈ 𝓝[u] a ↔ t ∈ comap ((↑) : s → α) (𝓝[(↑) '' u] a) := by
rw [nhdsWithin, nhds_subtype, principal_subtype, ← comap_inf, ← nhdsWithin]
#align mem_nhds_within_subtype mem_nhdsWithin_subtype
theorem nhdsWithin_subtype (s : Set α) (a : { x // x ∈ s }) (t : Set { x // x ∈ s }) :
𝓝[t] a = comap ((↑) : s → α) (𝓝[(↑) '' t] a) :=
Filter.ext fun _ => mem_nhdsWithin_subtype
#align nhds_within_subtype nhdsWithin_subtype
theorem nhdsWithin_eq_map_subtype_coe {s : Set α} {a : α} (h : a ∈ s) :
𝓝[s] a = map ((↑) : s → α) (𝓝 ⟨a, h⟩) :=
(map_nhds_subtype_val ⟨a, h⟩).symm
#align nhds_within_eq_map_subtype_coe nhdsWithin_eq_map_subtype_coe
theorem mem_nhds_subtype_iff_nhdsWithin {s : Set α} {a : s} {t : Set s} :
t ∈ 𝓝 a ↔ (↑) '' t ∈ 𝓝[s] (a : α) := by
rw [← map_nhds_subtype_val, image_mem_map_iff Subtype.val_injective]
#align mem_nhds_subtype_iff_nhds_within mem_nhds_subtype_iff_nhdsWithin
theorem preimage_coe_mem_nhds_subtype {s t : Set α} {a : s} : (↑) ⁻¹' t ∈ 𝓝 a ↔ t ∈ 𝓝[s] ↑a := by
rw [← map_nhds_subtype_val, mem_map]
#align preimage_coe_mem_nhds_subtype preimage_coe_mem_nhds_subtype
theorem eventually_nhds_subtype_iff (s : Set α) (a : s) (P : α → Prop) :
(∀ᶠ x : s in 𝓝 a, P x) ↔ ∀ᶠ x in 𝓝[s] a, P x :=
preimage_coe_mem_nhds_subtype
theorem frequently_nhds_subtype_iff (s : Set α) (a : s) (P : α → Prop) :
(∃ᶠ x : s in 𝓝 a, P x) ↔ ∃ᶠ x in 𝓝[s] a, P x :=
eventually_nhds_subtype_iff s a (¬ P ·) |>.not
theorem tendsto_nhdsWithin_iff_subtype {s : Set α} {a : α} (h : a ∈ s) (f : α → β) (l : Filter β) :
Tendsto f (𝓝[s] a) l ↔ Tendsto (s.restrict f) (𝓝 ⟨a, h⟩) l := by
rw [nhdsWithin_eq_map_subtype_coe h, tendsto_map'_iff]; rfl
#align tendsto_nhds_within_iff_subtype tendsto_nhdsWithin_iff_subtype
variable [TopologicalSpace β] [TopologicalSpace γ] [TopologicalSpace δ]
theorem ContinuousWithinAt.tendsto {f : α → β} {s : Set α} {x : α} (h : ContinuousWithinAt f s x) :
Tendsto f (𝓝[s] x) (𝓝 (f x)) :=
h
#align continuous_within_at.tendsto ContinuousWithinAt.tendsto
theorem ContinuousOn.continuousWithinAt {f : α → β} {s : Set α} {x : α} (hf : ContinuousOn f s)
(hx : x ∈ s) : ContinuousWithinAt f s x :=
hf x hx
#align continuous_on.continuous_within_at ContinuousOn.continuousWithinAt
theorem continuousWithinAt_univ (f : α → β) (x : α) :
ContinuousWithinAt f Set.univ x ↔ ContinuousAt f x := by
rw [ContinuousAt, ContinuousWithinAt, nhdsWithin_univ]
#align continuous_within_at_univ continuousWithinAt_univ
theorem continuous_iff_continuousOn_univ {f : α → β} : Continuous f ↔ ContinuousOn f univ := by
simp [continuous_iff_continuousAt, ContinuousOn, ContinuousAt, ContinuousWithinAt,
nhdsWithin_univ]
#align continuous_iff_continuous_on_univ continuous_iff_continuousOn_univ
theorem continuousWithinAt_iff_continuousAt_restrict (f : α → β) {x : α} {s : Set α} (h : x ∈ s) :
ContinuousWithinAt f s x ↔ ContinuousAt (s.restrict f) ⟨x, h⟩ :=
tendsto_nhdsWithin_iff_subtype h f _
#align continuous_within_at_iff_continuous_at_restrict continuousWithinAt_iff_continuousAt_restrict
theorem ContinuousWithinAt.tendsto_nhdsWithin {f : α → β} {x : α} {s : Set α} {t : Set β}
(h : ContinuousWithinAt f s x) (ht : MapsTo f s t) : Tendsto f (𝓝[s] x) (𝓝[t] f x) :=
tendsto_inf.2 ⟨h, tendsto_principal.2 <| mem_inf_of_right <| mem_principal.2 <| ht⟩
#align continuous_within_at.tendsto_nhds_within ContinuousWithinAt.tendsto_nhdsWithin
theorem ContinuousWithinAt.tendsto_nhdsWithin_image {f : α → β} {x : α} {s : Set α}
(h : ContinuousWithinAt f s x) : Tendsto f (𝓝[s] x) (𝓝[f '' s] f x) :=
h.tendsto_nhdsWithin (mapsTo_image _ _)
#align continuous_within_at.tendsto_nhds_within_image ContinuousWithinAt.tendsto_nhdsWithin_image
theorem ContinuousWithinAt.prod_map {f : α → γ} {g : β → δ} {s : Set α} {t : Set β} {x : α} {y : β}
(hf : ContinuousWithinAt f s x) (hg : ContinuousWithinAt g t y) :
ContinuousWithinAt (Prod.map f g) (s ×ˢ t) (x, y) := by
unfold ContinuousWithinAt at *
rw [nhdsWithin_prod_eq, Prod.map, nhds_prod_eq]
exact hf.prod_map hg
#align continuous_within_at.prod_map ContinuousWithinAt.prod_map
theorem continuousWithinAt_prod_of_discrete_left [DiscreteTopology α]
{f : α × β → γ} {s : Set (α × β)} {x : α × β} :
ContinuousWithinAt f s x ↔ ContinuousWithinAt (f ⟨x.1, ·⟩) {b | (x.1, b) ∈ s} x.2 := by
rw [← x.eta]; simp_rw [ContinuousWithinAt, nhdsWithin, nhds_prod_eq, nhds_discrete, pure_prod,
← map_inf_principal_preimage]; rfl
theorem continuousWithinAt_prod_of_discrete_right [DiscreteTopology β]
{f : α × β → γ} {s : Set (α × β)} {x : α × β} :
ContinuousWithinAt f s x ↔ ContinuousWithinAt (f ⟨·, x.2⟩) {a | (a, x.2) ∈ s} x.1 := by
rw [← x.eta]; simp_rw [ContinuousWithinAt, nhdsWithin, nhds_prod_eq, nhds_discrete, prod_pure,
← map_inf_principal_preimage]; rfl
theorem continuousAt_prod_of_discrete_left [DiscreteTopology α] {f : α × β → γ} {x : α × β} :
ContinuousAt f x ↔ ContinuousAt (f ⟨x.1, ·⟩) x.2 := by
simp_rw [← continuousWithinAt_univ]; exact continuousWithinAt_prod_of_discrete_left
theorem continuousAt_prod_of_discrete_right [DiscreteTopology β] {f : α × β → γ} {x : α × β} :
ContinuousAt f x ↔ ContinuousAt (f ⟨·, x.2⟩) x.1 := by
simp_rw [← continuousWithinAt_univ]; exact continuousWithinAt_prod_of_discrete_right
theorem continuousOn_prod_of_discrete_left [DiscreteTopology α] {f : α × β → γ} {s : Set (α × β)} :
ContinuousOn f s ↔ ∀ a, ContinuousOn (f ⟨a, ·⟩) {b | (a, b) ∈ s} := by
simp_rw [ContinuousOn, Prod.forall, continuousWithinAt_prod_of_discrete_left]; rfl
theorem continuousOn_prod_of_discrete_right [DiscreteTopology β] {f : α × β → γ} {s : Set (α × β)} :
ContinuousOn f s ↔ ∀ b, ContinuousOn (f ⟨·, b⟩) {a | (a, b) ∈ s} := by
simp_rw [ContinuousOn, Prod.forall, continuousWithinAt_prod_of_discrete_right]; apply forall_swap
theorem continuous_prod_of_discrete_left [DiscreteTopology α] {f : α × β → γ} :
Continuous f ↔ ∀ a, Continuous (f ⟨a, ·⟩) := by
simp_rw [continuous_iff_continuousOn_univ]; exact continuousOn_prod_of_discrete_left
theorem continuous_prod_of_discrete_right [DiscreteTopology β] {f : α × β → γ} :
Continuous f ↔ ∀ b, Continuous (f ⟨·, b⟩) := by
simp_rw [continuous_iff_continuousOn_univ]; exact continuousOn_prod_of_discrete_right
theorem isOpenMap_prod_of_discrete_left [DiscreteTopology α] {f : α × β → γ} :
IsOpenMap f ↔ ∀ a, IsOpenMap (f ⟨a, ·⟩) := by
simp_rw [isOpenMap_iff_nhds_le, Prod.forall, nhds_prod_eq, nhds_discrete, pure_prod, map_map]
rfl
theorem isOpenMap_prod_of_discrete_right [DiscreteTopology β] {f : α × β → γ} :
IsOpenMap f ↔ ∀ b, IsOpenMap (f ⟨·, b⟩) := by
simp_rw [isOpenMap_iff_nhds_le, Prod.forall, forall_swap (α := α) (β := β), nhds_prod_eq,
nhds_discrete, prod_pure, map_map]; rfl
theorem continuousWithinAt_pi {ι : Type*} {π : ι → Type*} [∀ i, TopologicalSpace (π i)]
{f : α → ∀ i, π i} {s : Set α} {x : α} :
ContinuousWithinAt f s x ↔ ∀ i, ContinuousWithinAt (fun y => f y i) s x :=
tendsto_pi_nhds
#align continuous_within_at_pi continuousWithinAt_pi
theorem continuousOn_pi {ι : Type*} {π : ι → Type*} [∀ i, TopologicalSpace (π i)]
{f : α → ∀ i, π i} {s : Set α} : ContinuousOn f s ↔ ∀ i, ContinuousOn (fun y => f y i) s :=
⟨fun h i x hx => tendsto_pi_nhds.1 (h x hx) i, fun h x hx => tendsto_pi_nhds.2 fun i => h i x hx⟩
#align continuous_on_pi continuousOn_pi
@[fun_prop]
theorem continuousOn_pi' {ι : Type*} {π : ι → Type*} [∀ i, TopologicalSpace (π i)]
{f : α → ∀ i, π i} {s : Set α} (hf : ∀ i, ContinuousOn (fun y => f y i) s) :
ContinuousOn f s :=
continuousOn_pi.2 hf
theorem ContinuousWithinAt.fin_insertNth {n} {π : Fin (n + 1) → Type*}
[∀ i, TopologicalSpace (π i)] (i : Fin (n + 1)) {f : α → π i} {a : α} {s : Set α}
(hf : ContinuousWithinAt f s a) {g : α → ∀ j : Fin n, π (i.succAbove j)}
(hg : ContinuousWithinAt g s a) : ContinuousWithinAt (fun a => i.insertNth (f a) (g a)) s a :=
hf.tendsto.fin_insertNth i hg
#align continuous_within_at.fin_insert_nth ContinuousWithinAt.fin_insertNth
nonrec theorem ContinuousOn.fin_insertNth {n} {π : Fin (n + 1) → Type*}
[∀ i, TopologicalSpace (π i)] (i : Fin (n + 1)) {f : α → π i} {s : Set α}
(hf : ContinuousOn f s) {g : α → ∀ j : Fin n, π (i.succAbove j)} (hg : ContinuousOn g s) :
ContinuousOn (fun a => i.insertNth (f a) (g a)) s := fun a ha =>
(hf a ha).fin_insertNth i (hg a ha)
#align continuous_on.fin_insert_nth ContinuousOn.fin_insertNth
theorem continuousOn_iff {f : α → β} {s : Set α} :
ContinuousOn f s ↔
∀ x ∈ s, ∀ t : Set β, IsOpen t → f x ∈ t → ∃ u, IsOpen u ∧ x ∈ u ∧ u ∩ s ⊆ f ⁻¹' t := by
simp only [ContinuousOn, ContinuousWithinAt, tendsto_nhds, mem_nhdsWithin]
#align continuous_on_iff continuousOn_iff
theorem continuousOn_iff_continuous_restrict {f : α → β} {s : Set α} :
ContinuousOn f s ↔ Continuous (s.restrict f) := by
rw [ContinuousOn, continuous_iff_continuousAt]; constructor
· rintro h ⟨x, xs⟩
exact (continuousWithinAt_iff_continuousAt_restrict f xs).mp (h x xs)
intro h x xs
exact (continuousWithinAt_iff_continuousAt_restrict f xs).mpr (h ⟨x, xs⟩)
#align continuous_on_iff_continuous_restrict continuousOn_iff_continuous_restrict
-- Porting note: 2 new lemmas
alias ⟨ContinuousOn.restrict, _⟩ := continuousOn_iff_continuous_restrict
theorem ContinuousOn.restrict_mapsTo {f : α → β} {s : Set α} {t : Set β} (hf : ContinuousOn f s)
(ht : MapsTo f s t) : Continuous (ht.restrict f s t) :=
hf.restrict.codRestrict _
theorem continuousOn_iff' {f : α → β} {s : Set α} :
ContinuousOn f s ↔ ∀ t : Set β, IsOpen t → ∃ u, IsOpen u ∧ f ⁻¹' t ∩ s = u ∩ s := by
have : ∀ t, IsOpen (s.restrict f ⁻¹' t) ↔ ∃ u : Set α, IsOpen u ∧ f ⁻¹' t ∩ s = u ∩ s := by
intro t
rw [isOpen_induced_iff, Set.restrict_eq, Set.preimage_comp]
simp only [Subtype.preimage_coe_eq_preimage_coe_iff]
constructor <;>
· rintro ⟨u, ou, useq⟩
exact ⟨u, ou, by simpa only [Set.inter_comm, eq_comm] using useq⟩
rw [continuousOn_iff_continuous_restrict, continuous_def]; simp only [this]
#align continuous_on_iff' continuousOn_iff'
theorem ContinuousOn.mono_dom {α β : Type*} {t₁ t₂ : TopologicalSpace α} {t₃ : TopologicalSpace β}
(h₁ : t₂ ≤ t₁) {s : Set α} {f : α → β} (h₂ : @ContinuousOn α β t₁ t₃ f s) :
@ContinuousOn α β t₂ t₃ f s := fun x hx _u hu =>
map_mono (inf_le_inf_right _ <| nhds_mono h₁) (h₂ x hx hu)
#align continuous_on.mono_dom ContinuousOn.mono_dom
theorem ContinuousOn.mono_rng {α β : Type*} {t₁ : TopologicalSpace α} {t₂ t₃ : TopologicalSpace β}
(h₁ : t₂ ≤ t₃) {s : Set α} {f : α → β} (h₂ : @ContinuousOn α β t₁ t₂ f s) :
@ContinuousOn α β t₁ t₃ f s := fun x hx _u hu =>
h₂ x hx <| nhds_mono h₁ hu
#align continuous_on.mono_rng ContinuousOn.mono_rng
theorem continuousOn_iff_isClosed {f : α → β} {s : Set α} :
ContinuousOn f s ↔ ∀ t : Set β, IsClosed t → ∃ u, IsClosed u ∧ f ⁻¹' t ∩ s = u ∩ s := by
have : ∀ t, IsClosed (s.restrict f ⁻¹' t) ↔ ∃ u : Set α, IsClosed u ∧ f ⁻¹' t ∩ s = u ∩ s := by
intro t
rw [isClosed_induced_iff, Set.restrict_eq, Set.preimage_comp]
simp only [Subtype.preimage_coe_eq_preimage_coe_iff, eq_comm, Set.inter_comm s]
rw [continuousOn_iff_continuous_restrict, continuous_iff_isClosed]; simp only [this]
#align continuous_on_iff_is_closed continuousOn_iff_isClosed
theorem ContinuousOn.prod_map {f : α → γ} {g : β → δ} {s : Set α} {t : Set β}
(hf : ContinuousOn f s) (hg : ContinuousOn g t) : ContinuousOn (Prod.map f g) (s ×ˢ t) :=
fun ⟨x, y⟩ ⟨hx, hy⟩ => ContinuousWithinAt.prod_map (hf x hx) (hg y hy)
#align continuous_on.prod_map ContinuousOn.prod_map
theorem continuous_of_cover_nhds {ι : Sort*} {f : α → β} {s : ι → Set α}
(hs : ∀ x : α, ∃ i, s i ∈ 𝓝 x) (hf : ∀ i, ContinuousOn f (s i)) :
Continuous f :=
continuous_iff_continuousAt.mpr fun x ↦ let ⟨i, hi⟩ := hs x; by
rw [ContinuousAt, ← nhdsWithin_eq_nhds.2 hi]
exact hf _ _ (mem_of_mem_nhds hi)
#align continuous_of_cover_nhds continuous_of_cover_nhds
theorem continuousOn_empty (f : α → β) : ContinuousOn f ∅ := fun _ => False.elim
#align continuous_on_empty continuousOn_empty
@[simp]
theorem continuousOn_singleton (f : α → β) (a : α) : ContinuousOn f {a} :=
forall_eq.2 <| by
simpa only [ContinuousWithinAt, nhdsWithin_singleton, tendsto_pure_left] using fun s =>
mem_of_mem_nhds
#align continuous_on_singleton continuousOn_singleton
theorem Set.Subsingleton.continuousOn {s : Set α} (hs : s.Subsingleton) (f : α → β) :
ContinuousOn f s :=
hs.induction_on (continuousOn_empty f) (continuousOn_singleton f)
#align set.subsingleton.continuous_on Set.Subsingleton.continuousOn
theorem nhdsWithin_le_comap {x : α} {s : Set α} {f : α → β} (ctsf : ContinuousWithinAt f s x) :
𝓝[s] x ≤ comap f (𝓝[f '' s] f x) :=
ctsf.tendsto_nhdsWithin_image.le_comap
#align nhds_within_le_comap nhdsWithin_le_comap
@[simp]
theorem comap_nhdsWithin_range {α} (f : α → β) (y : β) : comap f (𝓝[range f] y) = comap f (𝓝 y) :=
comap_inf_principal_range
#align comap_nhds_within_range comap_nhdsWithin_range
theorem ContinuousWithinAt.mono {f : α → β} {s t : Set α} {x : α} (h : ContinuousWithinAt f t x)
(hs : s ⊆ t) : ContinuousWithinAt f s x :=
h.mono_left (nhdsWithin_mono x hs)
#align continuous_within_at.mono ContinuousWithinAt.mono
theorem ContinuousWithinAt.mono_of_mem {f : α → β} {s t : Set α} {x : α}
(h : ContinuousWithinAt f t x) (hs : t ∈ 𝓝[s] x) : ContinuousWithinAt f s x :=
h.mono_left (nhdsWithin_le_of_mem hs)
#align continuous_within_at.mono_of_mem ContinuousWithinAt.mono_of_mem
theorem continuousWithinAt_congr_nhds {f : α → β} {s t : Set α} {x : α} (h : 𝓝[s] x = 𝓝[t] x) :
ContinuousWithinAt f s x ↔ ContinuousWithinAt f t x := by
simp only [ContinuousWithinAt, h]
theorem continuousWithinAt_inter' {f : α → β} {s t : Set α} {x : α} (h : t ∈ 𝓝[s] x) :
ContinuousWithinAt f (s ∩ t) x ↔ ContinuousWithinAt f s x := by
simp [ContinuousWithinAt, nhdsWithin_restrict'' s h]
#align continuous_within_at_inter' continuousWithinAt_inter'
theorem continuousWithinAt_inter {f : α → β} {s t : Set α} {x : α} (h : t ∈ 𝓝 x) :
ContinuousWithinAt f (s ∩ t) x ↔ ContinuousWithinAt f s x := by
simp [ContinuousWithinAt, nhdsWithin_restrict' s h]
#align continuous_within_at_inter continuousWithinAt_inter
theorem continuousWithinAt_union {f : α → β} {s t : Set α} {x : α} :
ContinuousWithinAt f (s ∪ t) x ↔ ContinuousWithinAt f s x ∧ ContinuousWithinAt f t x := by
simp only [ContinuousWithinAt, nhdsWithin_union, tendsto_sup]
#align continuous_within_at_union continuousWithinAt_union
theorem ContinuousWithinAt.union {f : α → β} {s t : Set α} {x : α} (hs : ContinuousWithinAt f s x)
(ht : ContinuousWithinAt f t x) : ContinuousWithinAt f (s ∪ t) x :=
continuousWithinAt_union.2 ⟨hs, ht⟩
#align continuous_within_at.union ContinuousWithinAt.union
theorem ContinuousWithinAt.mem_closure_image {f : α → β} {s : Set α} {x : α}
(h : ContinuousWithinAt f s x) (hx : x ∈ closure s) : f x ∈ closure (f '' s) :=
haveI := mem_closure_iff_nhdsWithin_neBot.1 hx
mem_closure_of_tendsto h <| mem_of_superset self_mem_nhdsWithin (subset_preimage_image f s)
#align continuous_within_at.mem_closure_image ContinuousWithinAt.mem_closure_image
theorem ContinuousWithinAt.mem_closure {f : α → β} {s : Set α} {x : α} {A : Set β}
(h : ContinuousWithinAt f s x) (hx : x ∈ closure s) (hA : MapsTo f s A) : f x ∈ closure A :=
closure_mono (image_subset_iff.2 hA) (h.mem_closure_image hx)
#align continuous_within_at.mem_closure ContinuousWithinAt.mem_closure
theorem Set.MapsTo.closure_of_continuousWithinAt {f : α → β} {s : Set α} {t : Set β}
(h : MapsTo f s t) (hc : ∀ x ∈ closure s, ContinuousWithinAt f s x) :
MapsTo f (closure s) (closure t) := fun x hx => (hc x hx).mem_closure hx h
#align set.maps_to.closure_of_continuous_within_at Set.MapsTo.closure_of_continuousWithinAt
theorem Set.MapsTo.closure_of_continuousOn {f : α → β} {s : Set α} {t : Set β} (h : MapsTo f s t)
(hc : ContinuousOn f (closure s)) : MapsTo f (closure s) (closure t) :=
h.closure_of_continuousWithinAt fun x hx => (hc x hx).mono subset_closure
#align set.maps_to.closure_of_continuous_on Set.MapsTo.closure_of_continuousOn
theorem ContinuousWithinAt.image_closure {f : α → β} {s : Set α}
(hf : ∀ x ∈ closure s, ContinuousWithinAt f s x) : f '' closure s ⊆ closure (f '' s) :=
((mapsTo_image f s).closure_of_continuousWithinAt hf).image_subset
#align continuous_within_at.image_closure ContinuousWithinAt.image_closure
theorem ContinuousOn.image_closure {f : α → β} {s : Set α} (hf : ContinuousOn f (closure s)) :
f '' closure s ⊆ closure (f '' s) :=
ContinuousWithinAt.image_closure fun x hx => (hf x hx).mono subset_closure
#align continuous_on.image_closure ContinuousOn.image_closure
@[simp]
theorem continuousWithinAt_singleton {f : α → β} {x : α} : ContinuousWithinAt f {x} x := by
simp only [ContinuousWithinAt, nhdsWithin_singleton, tendsto_pure_nhds]
#align continuous_within_at_singleton continuousWithinAt_singleton
@[simp]
theorem continuousWithinAt_insert_self {f : α → β} {x : α} {s : Set α} :
ContinuousWithinAt f (insert x s) x ↔ ContinuousWithinAt f s x := by
simp only [← singleton_union, continuousWithinAt_union, continuousWithinAt_singleton,
true_and_iff]
#align continuous_within_at_insert_self continuousWithinAt_insert_self
alias ⟨_, ContinuousWithinAt.insert_self⟩ := continuousWithinAt_insert_self
#align continuous_within_at.insert_self ContinuousWithinAt.insert_self
theorem ContinuousWithinAt.diff_iff {f : α → β} {s t : Set α} {x : α}
(ht : ContinuousWithinAt f t x) : ContinuousWithinAt f (s \ t) x ↔ ContinuousWithinAt f s x :=
⟨fun h => (h.union ht).mono <| by simp only [diff_union_self, subset_union_left], fun h =>
h.mono diff_subset⟩
#align continuous_within_at.diff_iff ContinuousWithinAt.diff_iff
@[simp]
theorem continuousWithinAt_diff_self {f : α → β} {s : Set α} {x : α} :
ContinuousWithinAt f (s \ {x}) x ↔ ContinuousWithinAt f s x :=
continuousWithinAt_singleton.diff_iff
#align continuous_within_at_diff_self continuousWithinAt_diff_self
@[simp]
theorem continuousWithinAt_compl_self {f : α → β} {a : α} :
ContinuousWithinAt f {a}ᶜ a ↔ ContinuousAt f a := by
rw [compl_eq_univ_diff, continuousWithinAt_diff_self, continuousWithinAt_univ]
#align continuous_within_at_compl_self continuousWithinAt_compl_self
@[simp]
theorem continuousWithinAt_update_same [DecidableEq α] {f : α → β} {s : Set α} {x : α} {y : β} :
ContinuousWithinAt (update f x y) s x ↔ Tendsto f (𝓝[s \ {x}] x) (𝓝 y) :=
calc
ContinuousWithinAt (update f x y) s x ↔ Tendsto (update f x y) (𝓝[s \ {x}] x) (𝓝 y) := by
{ rw [← continuousWithinAt_diff_self, ContinuousWithinAt, update_same] }
_ ↔ Tendsto f (𝓝[s \ {x}] x) (𝓝 y) :=
tendsto_congr' <| eventually_nhdsWithin_iff.2 <| eventually_of_forall
fun z hz => update_noteq hz.2 _ _
#align continuous_within_at_update_same continuousWithinAt_update_same
@[simp]
theorem continuousAt_update_same [DecidableEq α] {f : α → β} {x : α} {y : β} :
ContinuousAt (Function.update f x y) x ↔ Tendsto f (𝓝[≠] x) (𝓝 y) := by
rw [← continuousWithinAt_univ, continuousWithinAt_update_same, compl_eq_univ_diff]
#align continuous_at_update_same continuousAt_update_same
theorem IsOpenMap.continuousOn_image_of_leftInvOn {f : α → β} {s : Set α}
(h : IsOpenMap (s.restrict f)) {finv : β → α} (hleft : LeftInvOn finv f s) :
ContinuousOn finv (f '' s) := by
refine continuousOn_iff'.2 fun t ht => ⟨f '' (t ∩ s), ?_, ?_⟩
· rw [← image_restrict]
exact h _ (ht.preimage continuous_subtype_val)
· rw [inter_eq_self_of_subset_left (image_subset f inter_subset_right), hleft.image_inter']
#align is_open_map.continuous_on_image_of_left_inv_on IsOpenMap.continuousOn_image_of_leftInvOn
theorem IsOpenMap.continuousOn_range_of_leftInverse {f : α → β} (hf : IsOpenMap f) {finv : β → α}
(hleft : Function.LeftInverse finv f) : ContinuousOn finv (range f) := by
rw [← image_univ]
exact (hf.restrict isOpen_univ).continuousOn_image_of_leftInvOn fun x _ => hleft x
#align is_open_map.continuous_on_range_of_left_inverse IsOpenMap.continuousOn_range_of_leftInverse
theorem ContinuousOn.congr_mono {f g : α → β} {s s₁ : Set α} (h : ContinuousOn f s)
(h' : EqOn g f s₁) (h₁ : s₁ ⊆ s) : ContinuousOn g s₁ := by
intro x hx
unfold ContinuousWithinAt
have A := (h x (h₁ hx)).mono h₁
unfold ContinuousWithinAt at A
rw [← h' hx] at A
exact A.congr' h'.eventuallyEq_nhdsWithin.symm
#align continuous_on.congr_mono ContinuousOn.congr_mono
theorem ContinuousOn.congr {f g : α → β} {s : Set α} (h : ContinuousOn f s) (h' : EqOn g f s) :
ContinuousOn g s :=
h.congr_mono h' (Subset.refl _)
#align continuous_on.congr ContinuousOn.congr
theorem continuousOn_congr {f g : α → β} {s : Set α} (h' : EqOn g f s) :
ContinuousOn g s ↔ ContinuousOn f s :=
⟨fun h => ContinuousOn.congr h h'.symm, fun h => h.congr h'⟩
#align continuous_on_congr continuousOn_congr
theorem ContinuousAt.continuousWithinAt {f : α → β} {s : Set α} {x : α} (h : ContinuousAt f x) :
ContinuousWithinAt f s x :=
ContinuousWithinAt.mono ((continuousWithinAt_univ f x).2 h) (subset_univ _)
#align continuous_at.continuous_within_at ContinuousAt.continuousWithinAt
theorem continuousWithinAt_iff_continuousAt {f : α → β} {s : Set α} {x : α} (h : s ∈ 𝓝 x) :
ContinuousWithinAt f s x ↔ ContinuousAt f x := by
rw [← univ_inter s, continuousWithinAt_inter h, continuousWithinAt_univ]
#align continuous_within_at_iff_continuous_at continuousWithinAt_iff_continuousAt
theorem ContinuousWithinAt.continuousAt {f : α → β} {s : Set α} {x : α}
(h : ContinuousWithinAt f s x) (hs : s ∈ 𝓝 x) : ContinuousAt f x :=
(continuousWithinAt_iff_continuousAt hs).mp h
#align continuous_within_at.continuous_at ContinuousWithinAt.continuousAt
theorem IsOpen.continuousOn_iff {f : α → β} {s : Set α} (hs : IsOpen s) :
ContinuousOn f s ↔ ∀ ⦃a⦄, a ∈ s → ContinuousAt f a :=
forall₂_congr fun _ => continuousWithinAt_iff_continuousAt ∘ hs.mem_nhds
#align is_open.continuous_on_iff IsOpen.continuousOn_iff
theorem ContinuousOn.continuousAt {f : α → β} {s : Set α} {x : α} (h : ContinuousOn f s)
(hx : s ∈ 𝓝 x) : ContinuousAt f x :=
(h x (mem_of_mem_nhds hx)).continuousAt hx
#align continuous_on.continuous_at ContinuousOn.continuousAt
theorem ContinuousAt.continuousOn {f : α → β} {s : Set α} (hcont : ∀ x ∈ s, ContinuousAt f x) :
ContinuousOn f s := fun x hx => (hcont x hx).continuousWithinAt
#align continuous_at.continuous_on ContinuousAt.continuousOn
theorem ContinuousWithinAt.comp {g : β → γ} {f : α → β} {s : Set α} {t : Set β} {x : α}
(hg : ContinuousWithinAt g t (f x)) (hf : ContinuousWithinAt f s x) (h : MapsTo f s t) :
ContinuousWithinAt (g ∘ f) s x :=
hg.tendsto.comp (hf.tendsto_nhdsWithin h)
#align continuous_within_at.comp ContinuousWithinAt.comp
theorem ContinuousWithinAt.comp' {g : β → γ} {f : α → β} {s : Set α} {t : Set β} {x : α}
(hg : ContinuousWithinAt g t (f x)) (hf : ContinuousWithinAt f s x) :
ContinuousWithinAt (g ∘ f) (s ∩ f ⁻¹' t) x :=
hg.comp (hf.mono inter_subset_left) inter_subset_right
#align continuous_within_at.comp' ContinuousWithinAt.comp'
theorem ContinuousAt.comp_continuousWithinAt {g : β → γ} {f : α → β} {s : Set α} {x : α}
(hg : ContinuousAt g (f x)) (hf : ContinuousWithinAt f s x) : ContinuousWithinAt (g ∘ f) s x :=
hg.continuousWithinAt.comp hf (mapsTo_univ _ _)
#align continuous_at.comp_continuous_within_at ContinuousAt.comp_continuousWithinAt
theorem ContinuousOn.comp {g : β → γ} {f : α → β} {s : Set α} {t : Set β} (hg : ContinuousOn g t)
(hf : ContinuousOn f s) (h : MapsTo f s t) : ContinuousOn (g ∘ f) s := fun x hx =>
ContinuousWithinAt.comp (hg _ (h hx)) (hf x hx) h
#align continuous_on.comp ContinuousOn.comp
@[fun_prop]
theorem ContinuousOn.comp'' {g : β → γ} {f : α → β} {s : Set α} {t : Set β} (hg : ContinuousOn g t)
(hf : ContinuousOn f s) (h : Set.MapsTo f s t) : ContinuousOn (fun x => g (f x)) s :=
ContinuousOn.comp hg hf h
theorem ContinuousOn.mono {f : α → β} {s t : Set α} (hf : ContinuousOn f s) (h : t ⊆ s) :
ContinuousOn f t := fun x hx => (hf x (h hx)).mono_left (nhdsWithin_mono _ h)
#align continuous_on.mono ContinuousOn.mono
theorem antitone_continuousOn {f : α → β} : Antitone (ContinuousOn f) := fun _s _t hst hf =>
hf.mono hst
#align antitone_continuous_on antitone_continuousOn
@[fun_prop]
theorem ContinuousOn.comp' {g : β → γ} {f : α → β} {s : Set α} {t : Set β} (hg : ContinuousOn g t)
(hf : ContinuousOn f s) : ContinuousOn (g ∘ f) (s ∩ f ⁻¹' t) :=
hg.comp (hf.mono inter_subset_left) inter_subset_right
#align continuous_on.comp' ContinuousOn.comp'
@[fun_prop]
theorem Continuous.continuousOn {f : α → β} {s : Set α} (h : Continuous f) : ContinuousOn f s := by
rw [continuous_iff_continuousOn_univ] at h
exact h.mono (subset_univ _)
#align continuous.continuous_on Continuous.continuousOn
theorem Continuous.continuousWithinAt {f : α → β} {s : Set α} {x : α} (h : Continuous f) :
ContinuousWithinAt f s x :=
h.continuousAt.continuousWithinAt
#align continuous.continuous_within_at Continuous.continuousWithinAt
theorem Continuous.comp_continuousOn {g : β → γ} {f : α → β} {s : Set α} (hg : Continuous g)
(hf : ContinuousOn f s) : ContinuousOn (g ∘ f) s :=
hg.continuousOn.comp hf (mapsTo_univ _ _)
#align continuous.comp_continuous_on Continuous.comp_continuousOn
@[fun_prop]
theorem Continuous.comp_continuousOn'
{α β γ : Type*} [TopologicalSpace α] [TopologicalSpace β] [TopologicalSpace γ] {g : β → γ}
{f : α → β} {s : Set α} (hg : Continuous g) (hf : ContinuousOn f s) :
ContinuousOn (fun x ↦ g (f x)) s :=
hg.comp_continuousOn hf
theorem ContinuousOn.comp_continuous {g : β → γ} {f : α → β} {s : Set β} (hg : ContinuousOn g s)
(hf : Continuous f) (hs : ∀ x, f x ∈ s) : Continuous (g ∘ f) := by
rw [continuous_iff_continuousOn_univ] at *
exact hg.comp hf fun x _ => hs x
#align continuous_on.comp_continuous ContinuousOn.comp_continuous
@[fun_prop]
theorem continuousOn_apply {ι : Type*} {π : ι → Type*} [∀ i, TopologicalSpace (π i)]
(i : ι) (s) : ContinuousOn (fun p : ∀ i, π i => p i) s :=
Continuous.continuousOn (continuous_apply i)
theorem ContinuousWithinAt.preimage_mem_nhdsWithin {f : α → β} {x : α} {s : Set α} {t : Set β}
(h : ContinuousWithinAt f s x) (ht : t ∈ 𝓝 (f x)) : f ⁻¹' t ∈ 𝓝[s] x :=
h ht
#align continuous_within_at.preimage_mem_nhds_within ContinuousWithinAt.preimage_mem_nhdsWithin
theorem Set.LeftInvOn.map_nhdsWithin_eq {f : α → β} {g : β → α} {x : β} {s : Set β}
(h : LeftInvOn f g s) (hx : f (g x) = x) (hf : ContinuousWithinAt f (g '' s) (g x))
(hg : ContinuousWithinAt g s x) : map g (𝓝[s] x) = 𝓝[g '' s] g x := by
apply le_antisymm
· exact hg.tendsto_nhdsWithin (mapsTo_image _ _)
· have A : g ∘ f =ᶠ[𝓝[g '' s] g x] id :=
h.rightInvOn_image.eqOn.eventuallyEq_of_mem self_mem_nhdsWithin
refine le_map_of_right_inverse A ?_
simpa only [hx] using hf.tendsto_nhdsWithin (h.mapsTo (surjOn_image _ _))
#align set.left_inv_on.map_nhds_within_eq Set.LeftInvOn.map_nhdsWithin_eq
theorem Function.LeftInverse.map_nhds_eq {f : α → β} {g : β → α} {x : β}
(h : Function.LeftInverse f g) (hf : ContinuousWithinAt f (range g) (g x))
(hg : ContinuousAt g x) : map g (𝓝 x) = 𝓝[range g] g x := by
simpa only [nhdsWithin_univ, image_univ] using
(h.leftInvOn univ).map_nhdsWithin_eq (h x) (by rwa [image_univ]) hg.continuousWithinAt
#align function.left_inverse.map_nhds_eq Function.LeftInverse.map_nhds_eq
theorem ContinuousWithinAt.preimage_mem_nhdsWithin' {f : α → β} {x : α} {s : Set α} {t : Set β}
(h : ContinuousWithinAt f s x) (ht : t ∈ 𝓝[f '' s] f x) : f ⁻¹' t ∈ 𝓝[s] x :=
h.tendsto_nhdsWithin (mapsTo_image _ _) ht
#align continuous_within_at.preimage_mem_nhds_within' ContinuousWithinAt.preimage_mem_nhdsWithin'
theorem ContinuousWithinAt.preimage_mem_nhdsWithin''
{f : α → β} {x : α} {y : β} {s t : Set β}
(h : ContinuousWithinAt f (f ⁻¹' s) x) (ht : t ∈ 𝓝[s] y) (hxy : y = f x) :
f ⁻¹' t ∈ 𝓝[f ⁻¹' s] x := by
rw [hxy] at ht
exact h.preimage_mem_nhdsWithin' (nhdsWithin_mono _ (image_preimage_subset f s) ht)
theorem Filter.EventuallyEq.congr_continuousWithinAt {f g : α → β} {s : Set α} {x : α}
(h : f =ᶠ[𝓝[s] x] g) (hx : f x = g x) :
ContinuousWithinAt f s x ↔ ContinuousWithinAt g s x := by
rw [ContinuousWithinAt, hx, tendsto_congr' h, ContinuousWithinAt]
#align filter.eventually_eq.congr_continuous_within_at Filter.EventuallyEq.congr_continuousWithinAt
theorem ContinuousWithinAt.congr_of_eventuallyEq {f f₁ : α → β} {s : Set α} {x : α}
(h : ContinuousWithinAt f s x) (h₁ : f₁ =ᶠ[𝓝[s] x] f) (hx : f₁ x = f x) :
ContinuousWithinAt f₁ s x :=
(h₁.congr_continuousWithinAt hx).2 h
#align continuous_within_at.congr_of_eventually_eq ContinuousWithinAt.congr_of_eventuallyEq
theorem ContinuousWithinAt.congr {f f₁ : α → β} {s : Set α} {x : α} (h : ContinuousWithinAt f s x)
(h₁ : ∀ y ∈ s, f₁ y = f y) (hx : f₁ x = f x) : ContinuousWithinAt f₁ s x :=
h.congr_of_eventuallyEq (mem_of_superset self_mem_nhdsWithin h₁) hx
#align continuous_within_at.congr ContinuousWithinAt.congr
theorem ContinuousWithinAt.congr_mono {f g : α → β} {s s₁ : Set α} {x : α}
(h : ContinuousWithinAt f s x) (h' : EqOn g f s₁) (h₁ : s₁ ⊆ s) (hx : g x = f x) :
ContinuousWithinAt g s₁ x :=
(h.mono h₁).congr h' hx
#align continuous_within_at.congr_mono ContinuousWithinAt.congr_mono
@[fun_prop]
theorem continuousOn_const {s : Set α} {c : β} : ContinuousOn (fun _ => c) s :=
continuous_const.continuousOn
#align continuous_on_const continuousOn_const
theorem continuousWithinAt_const {b : β} {s : Set α} {x : α} :
ContinuousWithinAt (fun _ : α => b) s x :=
continuous_const.continuousWithinAt
#align continuous_within_at_const continuousWithinAt_const
theorem continuousOn_id {s : Set α} : ContinuousOn id s :=
continuous_id.continuousOn
#align continuous_on_id continuousOn_id
@[fun_prop]
theorem continuousOn_id' (s : Set α) : ContinuousOn (fun x : α => x) s := continuousOn_id
theorem continuousWithinAt_id {s : Set α} {x : α} : ContinuousWithinAt id s x :=
continuous_id.continuousWithinAt
#align continuous_within_at_id continuousWithinAt_id
| Mathlib/Topology/ContinuousOn.lean | 1,070 | 1,080 | theorem continuousOn_open_iff {f : α → β} {s : Set α} (hs : IsOpen s) :
ContinuousOn f s ↔ ∀ t, IsOpen t → IsOpen (s ∩ f ⁻¹' t) := by |
rw [continuousOn_iff']
constructor
· intro h t ht
rcases h t ht with ⟨u, u_open, hu⟩
rw [inter_comm, hu]
apply IsOpen.inter u_open hs
· intro h t ht
refine ⟨s ∩ f ⁻¹' t, h t ht, ?_⟩
rw [@inter_comm _ s (f ⁻¹' t), inter_assoc, inter_self]
|
import Mathlib.Topology.Maps
import Mathlib.Topology.NhdsSet
#align_import topology.constructions from "leanprover-community/mathlib"@"f7ebde7ee0d1505dfccac8644ae12371aa3c1c9f"
noncomputable section
open scoped Classical
open Topology TopologicalSpace Set Filter Function
universe u v
variable {X : Type u} {Y : Type v} {Z W ε ζ : Type*}
section Constructions
instance instTopologicalSpaceSubtype {p : X → Prop} [t : TopologicalSpace X] :
TopologicalSpace (Subtype p) :=
induced (↑) t
instance {r : X → X → Prop} [t : TopologicalSpace X] : TopologicalSpace (Quot r) :=
coinduced (Quot.mk r) t
instance instTopologicalSpaceQuotient {s : Setoid X} [t : TopologicalSpace X] :
TopologicalSpace (Quotient s) :=
coinduced Quotient.mk' t
instance instTopologicalSpaceProd [t₁ : TopologicalSpace X] [t₂ : TopologicalSpace Y] :
TopologicalSpace (X × Y) :=
induced Prod.fst t₁ ⊓ induced Prod.snd t₂
instance instTopologicalSpaceSum [t₁ : TopologicalSpace X] [t₂ : TopologicalSpace Y] :
TopologicalSpace (X ⊕ Y) :=
coinduced Sum.inl t₁ ⊔ coinduced Sum.inr t₂
instance instTopologicalSpaceSigma {ι : Type*} {X : ι → Type v} [t₂ : ∀ i, TopologicalSpace (X i)] :
TopologicalSpace (Sigma X) :=
⨆ i, coinduced (Sigma.mk i) (t₂ i)
instance Pi.topologicalSpace {ι : Type*} {Y : ι → Type v} [t₂ : (i : ι) → TopologicalSpace (Y i)] :
TopologicalSpace ((i : ι) → Y i) :=
⨅ i, induced (fun f => f i) (t₂ i)
#align Pi.topological_space Pi.topologicalSpace
instance ULift.topologicalSpace [t : TopologicalSpace X] : TopologicalSpace (ULift.{v, u} X) :=
t.induced ULift.down
#align ulift.topological_space ULift.topologicalSpace
section
variable [TopologicalSpace X]
open Additive Multiplicative
instance : TopologicalSpace (Additive X) := ‹TopologicalSpace X›
instance : TopologicalSpace (Multiplicative X) := ‹TopologicalSpace X›
instance [DiscreteTopology X] : DiscreteTopology (Additive X) := ‹DiscreteTopology X›
instance [DiscreteTopology X] : DiscreteTopology (Multiplicative X) := ‹DiscreteTopology X›
theorem continuous_ofMul : Continuous (ofMul : X → Additive X) := continuous_id
#align continuous_of_mul continuous_ofMul
theorem continuous_toMul : Continuous (toMul : Additive X → X) := continuous_id
#align continuous_to_mul continuous_toMul
theorem continuous_ofAdd : Continuous (ofAdd : X → Multiplicative X) := continuous_id
#align continuous_of_add continuous_ofAdd
theorem continuous_toAdd : Continuous (toAdd : Multiplicative X → X) := continuous_id
#align continuous_to_add continuous_toAdd
theorem isOpenMap_ofMul : IsOpenMap (ofMul : X → Additive X) := IsOpenMap.id
#align is_open_map_of_mul isOpenMap_ofMul
theorem isOpenMap_toMul : IsOpenMap (toMul : Additive X → X) := IsOpenMap.id
#align is_open_map_to_mul isOpenMap_toMul
theorem isOpenMap_ofAdd : IsOpenMap (ofAdd : X → Multiplicative X) := IsOpenMap.id
#align is_open_map_of_add isOpenMap_ofAdd
theorem isOpenMap_toAdd : IsOpenMap (toAdd : Multiplicative X → X) := IsOpenMap.id
#align is_open_map_to_add isOpenMap_toAdd
theorem isClosedMap_ofMul : IsClosedMap (ofMul : X → Additive X) := IsClosedMap.id
#align is_closed_map_of_mul isClosedMap_ofMul
theorem isClosedMap_toMul : IsClosedMap (toMul : Additive X → X) := IsClosedMap.id
#align is_closed_map_to_mul isClosedMap_toMul
theorem isClosedMap_ofAdd : IsClosedMap (ofAdd : X → Multiplicative X) := IsClosedMap.id
#align is_closed_map_of_add isClosedMap_ofAdd
theorem isClosedMap_toAdd : IsClosedMap (toAdd : Multiplicative X → X) := IsClosedMap.id
#align is_closed_map_to_add isClosedMap_toAdd
theorem nhds_ofMul (x : X) : 𝓝 (ofMul x) = map ofMul (𝓝 x) := rfl
#align nhds_of_mul nhds_ofMul
theorem nhds_ofAdd (x : X) : 𝓝 (ofAdd x) = map ofAdd (𝓝 x) := rfl
#align nhds_of_add nhds_ofAdd
theorem nhds_toMul (x : Additive X) : 𝓝 (toMul x) = map toMul (𝓝 x) := rfl
#align nhds_to_mul nhds_toMul
theorem nhds_toAdd (x : Multiplicative X) : 𝓝 (toAdd x) = map toAdd (𝓝 x) := rfl
#align nhds_to_add nhds_toAdd
end
section
variable [TopologicalSpace X]
open OrderDual
instance : TopologicalSpace Xᵒᵈ := ‹TopologicalSpace X›
instance [DiscreteTopology X] : DiscreteTopology Xᵒᵈ := ‹DiscreteTopology X›
theorem continuous_toDual : Continuous (toDual : X → Xᵒᵈ) := continuous_id
#align continuous_to_dual continuous_toDual
theorem continuous_ofDual : Continuous (ofDual : Xᵒᵈ → X) := continuous_id
#align continuous_of_dual continuous_ofDual
theorem isOpenMap_toDual : IsOpenMap (toDual : X → Xᵒᵈ) := IsOpenMap.id
#align is_open_map_to_dual isOpenMap_toDual
theorem isOpenMap_ofDual : IsOpenMap (ofDual : Xᵒᵈ → X) := IsOpenMap.id
#align is_open_map_of_dual isOpenMap_ofDual
theorem isClosedMap_toDual : IsClosedMap (toDual : X → Xᵒᵈ) := IsClosedMap.id
#align is_closed_map_to_dual isClosedMap_toDual
theorem isClosedMap_ofDual : IsClosedMap (ofDual : Xᵒᵈ → X) := IsClosedMap.id
#align is_closed_map_of_dual isClosedMap_ofDual
theorem nhds_toDual (x : X) : 𝓝 (toDual x) = map toDual (𝓝 x) := rfl
#align nhds_to_dual nhds_toDual
theorem nhds_ofDual (x : X) : 𝓝 (ofDual x) = map ofDual (𝓝 x) := rfl
#align nhds_of_dual nhds_ofDual
end
theorem Quotient.preimage_mem_nhds [TopologicalSpace X] [s : Setoid X] {V : Set <| Quotient s}
{x : X} (hs : V ∈ 𝓝 (Quotient.mk' x)) : Quotient.mk' ⁻¹' V ∈ 𝓝 x :=
preimage_nhds_coinduced hs
#align quotient.preimage_mem_nhds Quotient.preimage_mem_nhds
theorem Dense.quotient [Setoid X] [TopologicalSpace X] {s : Set X} (H : Dense s) :
Dense (Quotient.mk' '' s) :=
Quotient.surjective_Quotient_mk''.denseRange.dense_image continuous_coinduced_rng H
#align dense.quotient Dense.quotient
theorem DenseRange.quotient [Setoid X] [TopologicalSpace X] {f : Y → X} (hf : DenseRange f) :
DenseRange (Quotient.mk' ∘ f) :=
Quotient.surjective_Quotient_mk''.denseRange.comp hf continuous_coinduced_rng
#align dense_range.quotient DenseRange.quotient
theorem continuous_map_of_le {α : Type*} [TopologicalSpace α]
{s t : Setoid α} (h : s ≤ t) : Continuous (Setoid.map_of_le h) :=
continuous_coinduced_rng
theorem continuous_map_sInf {α : Type*} [TopologicalSpace α]
{S : Set (Setoid α)} {s : Setoid α} (h : s ∈ S) : Continuous (Setoid.map_sInf h) :=
continuous_coinduced_rng
instance {p : X → Prop} [TopologicalSpace X] [DiscreteTopology X] : DiscreteTopology (Subtype p) :=
⟨bot_unique fun s _ => ⟨(↑) '' s, isOpen_discrete _, preimage_image_eq _ Subtype.val_injective⟩⟩
instance Sum.discreteTopology [TopologicalSpace X] [TopologicalSpace Y] [h : DiscreteTopology X]
[hY : DiscreteTopology Y] : DiscreteTopology (X ⊕ Y) :=
⟨sup_eq_bot_iff.2 <| by simp [h.eq_bot, hY.eq_bot]⟩
#align sum.discrete_topology Sum.discreteTopology
instance Sigma.discreteTopology {ι : Type*} {Y : ι → Type v} [∀ i, TopologicalSpace (Y i)]
[h : ∀ i, DiscreteTopology (Y i)] : DiscreteTopology (Sigma Y) :=
⟨iSup_eq_bot.2 fun _ => by simp only [(h _).eq_bot, coinduced_bot]⟩
#align sigma.discrete_topology Sigma.discreteTopology
def CofiniteTopology (X : Type*) := X
#align cofinite_topology CofiniteTopology
section Prod
variable [TopologicalSpace X] [TopologicalSpace Y] [TopologicalSpace Z] [TopologicalSpace W]
[TopologicalSpace ε] [TopologicalSpace ζ]
-- Porting note (#11215): TODO: Lean 4 fails to deduce implicit args
@[simp] theorem continuous_prod_mk {f : X → Y} {g : X → Z} :
(Continuous fun x => (f x, g x)) ↔ Continuous f ∧ Continuous g :=
(@continuous_inf_rng X (Y × Z) _ _ (TopologicalSpace.induced Prod.fst _)
(TopologicalSpace.induced Prod.snd _)).trans <|
continuous_induced_rng.and continuous_induced_rng
#align continuous_prod_mk continuous_prod_mk
@[continuity]
theorem continuous_fst : Continuous (@Prod.fst X Y) :=
(continuous_prod_mk.1 continuous_id).1
#align continuous_fst continuous_fst
@[fun_prop]
theorem Continuous.fst {f : X → Y × Z} (hf : Continuous f) : Continuous fun x : X => (f x).1 :=
continuous_fst.comp hf
#align continuous.fst Continuous.fst
theorem Continuous.fst' {f : X → Z} (hf : Continuous f) : Continuous fun x : X × Y => f x.fst :=
hf.comp continuous_fst
#align continuous.fst' Continuous.fst'
theorem continuousAt_fst {p : X × Y} : ContinuousAt Prod.fst p :=
continuous_fst.continuousAt
#align continuous_at_fst continuousAt_fst
@[fun_prop]
theorem ContinuousAt.fst {f : X → Y × Z} {x : X} (hf : ContinuousAt f x) :
ContinuousAt (fun x : X => (f x).1) x :=
continuousAt_fst.comp hf
#align continuous_at.fst ContinuousAt.fst
theorem ContinuousAt.fst' {f : X → Z} {x : X} {y : Y} (hf : ContinuousAt f x) :
ContinuousAt (fun x : X × Y => f x.fst) (x, y) :=
ContinuousAt.comp hf continuousAt_fst
#align continuous_at.fst' ContinuousAt.fst'
theorem ContinuousAt.fst'' {f : X → Z} {x : X × Y} (hf : ContinuousAt f x.fst) :
ContinuousAt (fun x : X × Y => f x.fst) x :=
hf.comp continuousAt_fst
#align continuous_at.fst'' ContinuousAt.fst''
theorem Filter.Tendsto.fst_nhds {l : Filter X} {f : X → Y × Z} {p : Y × Z}
(h : Tendsto f l (𝓝 p)) : Tendsto (fun a ↦ (f a).1) l (𝓝 <| p.1) :=
continuousAt_fst.tendsto.comp h
@[continuity]
theorem continuous_snd : Continuous (@Prod.snd X Y) :=
(continuous_prod_mk.1 continuous_id).2
#align continuous_snd continuous_snd
@[fun_prop]
theorem Continuous.snd {f : X → Y × Z} (hf : Continuous f) : Continuous fun x : X => (f x).2 :=
continuous_snd.comp hf
#align continuous.snd Continuous.snd
theorem Continuous.snd' {f : Y → Z} (hf : Continuous f) : Continuous fun x : X × Y => f x.snd :=
hf.comp continuous_snd
#align continuous.snd' Continuous.snd'
theorem continuousAt_snd {p : X × Y} : ContinuousAt Prod.snd p :=
continuous_snd.continuousAt
#align continuous_at_snd continuousAt_snd
@[fun_prop]
theorem ContinuousAt.snd {f : X → Y × Z} {x : X} (hf : ContinuousAt f x) :
ContinuousAt (fun x : X => (f x).2) x :=
continuousAt_snd.comp hf
#align continuous_at.snd ContinuousAt.snd
theorem ContinuousAt.snd' {f : Y → Z} {x : X} {y : Y} (hf : ContinuousAt f y) :
ContinuousAt (fun x : X × Y => f x.snd) (x, y) :=
ContinuousAt.comp hf continuousAt_snd
#align continuous_at.snd' ContinuousAt.snd'
theorem ContinuousAt.snd'' {f : Y → Z} {x : X × Y} (hf : ContinuousAt f x.snd) :
ContinuousAt (fun x : X × Y => f x.snd) x :=
hf.comp continuousAt_snd
#align continuous_at.snd'' ContinuousAt.snd''
theorem Filter.Tendsto.snd_nhds {l : Filter X} {f : X → Y × Z} {p : Y × Z}
(h : Tendsto f l (𝓝 p)) : Tendsto (fun a ↦ (f a).2) l (𝓝 <| p.2) :=
continuousAt_snd.tendsto.comp h
@[continuity, fun_prop]
theorem Continuous.prod_mk {f : Z → X} {g : Z → Y} (hf : Continuous f) (hg : Continuous g) :
Continuous fun x => (f x, g x) :=
continuous_prod_mk.2 ⟨hf, hg⟩
#align continuous.prod_mk Continuous.prod_mk
@[continuity]
theorem Continuous.Prod.mk (x : X) : Continuous fun y : Y => (x, y) :=
continuous_const.prod_mk continuous_id
#align continuous.prod.mk Continuous.Prod.mk
@[continuity]
theorem Continuous.Prod.mk_left (y : Y) : Continuous fun x : X => (x, y) :=
continuous_id.prod_mk continuous_const
#align continuous.prod.mk_left Continuous.Prod.mk_left
lemma IsClosed.setOf_mapsTo {α : Type*} {f : X → α → Z} {s : Set α} {t : Set Z} (ht : IsClosed t)
(hf : ∀ a ∈ s, Continuous (f · a)) : IsClosed {x | MapsTo (f x) s t} := by
simpa only [MapsTo, setOf_forall] using isClosed_biInter fun y hy ↦ ht.preimage (hf y hy)
theorem Continuous.comp₂ {g : X × Y → Z} (hg : Continuous g) {e : W → X} (he : Continuous e)
{f : W → Y} (hf : Continuous f) : Continuous fun w => g (e w, f w) :=
hg.comp <| he.prod_mk hf
#align continuous.comp₂ Continuous.comp₂
theorem Continuous.comp₃ {g : X × Y × Z → ε} (hg : Continuous g) {e : W → X} (he : Continuous e)
{f : W → Y} (hf : Continuous f) {k : W → Z} (hk : Continuous k) :
Continuous fun w => g (e w, f w, k w) :=
hg.comp₂ he <| hf.prod_mk hk
#align continuous.comp₃ Continuous.comp₃
theorem Continuous.comp₄ {g : X × Y × Z × ζ → ε} (hg : Continuous g) {e : W → X} (he : Continuous e)
{f : W → Y} (hf : Continuous f) {k : W → Z} (hk : Continuous k) {l : W → ζ}
(hl : Continuous l) : Continuous fun w => g (e w, f w, k w, l w) :=
hg.comp₃ he hf <| hk.prod_mk hl
#align continuous.comp₄ Continuous.comp₄
@[continuity]
theorem Continuous.prod_map {f : Z → X} {g : W → Y} (hf : Continuous f) (hg : Continuous g) :
Continuous fun p : Z × W => (f p.1, g p.2) :=
hf.fst'.prod_mk hg.snd'
#align continuous.prod_map Continuous.prod_map
theorem continuous_inf_dom_left₂ {X Y Z} {f : X → Y → Z} {ta1 ta2 : TopologicalSpace X}
{tb1 tb2 : TopologicalSpace Y} {tc1 : TopologicalSpace Z}
(h : by haveI := ta1; haveI := tb1; exact Continuous fun p : X × Y => f p.1 p.2) : by
haveI := ta1 ⊓ ta2; haveI := tb1 ⊓ tb2; exact Continuous fun p : X × Y => f p.1 p.2 := by
have ha := @continuous_inf_dom_left _ _ id ta1 ta2 ta1 (@continuous_id _ (id _))
have hb := @continuous_inf_dom_left _ _ id tb1 tb2 tb1 (@continuous_id _ (id _))
have h_continuous_id := @Continuous.prod_map _ _ _ _ ta1 tb1 (ta1 ⊓ ta2) (tb1 ⊓ tb2) _ _ ha hb
exact @Continuous.comp _ _ _ (id _) (id _) _ _ _ h h_continuous_id
#align continuous_inf_dom_left₂ continuous_inf_dom_left₂
theorem continuous_inf_dom_right₂ {X Y Z} {f : X → Y → Z} {ta1 ta2 : TopologicalSpace X}
{tb1 tb2 : TopologicalSpace Y} {tc1 : TopologicalSpace Z}
(h : by haveI := ta2; haveI := tb2; exact Continuous fun p : X × Y => f p.1 p.2) : by
haveI := ta1 ⊓ ta2; haveI := tb1 ⊓ tb2; exact Continuous fun p : X × Y => f p.1 p.2 := by
have ha := @continuous_inf_dom_right _ _ id ta1 ta2 ta2 (@continuous_id _ (id _))
have hb := @continuous_inf_dom_right _ _ id tb1 tb2 tb2 (@continuous_id _ (id _))
have h_continuous_id := @Continuous.prod_map _ _ _ _ ta2 tb2 (ta1 ⊓ ta2) (tb1 ⊓ tb2) _ _ ha hb
exact @Continuous.comp _ _ _ (id _) (id _) _ _ _ h h_continuous_id
#align continuous_inf_dom_right₂ continuous_inf_dom_right₂
theorem continuous_sInf_dom₂ {X Y Z} {f : X → Y → Z} {tas : Set (TopologicalSpace X)}
{tbs : Set (TopologicalSpace Y)} {tX : TopologicalSpace X} {tY : TopologicalSpace Y}
{tc : TopologicalSpace Z} (hX : tX ∈ tas) (hY : tY ∈ tbs)
(hf : Continuous fun p : X × Y => f p.1 p.2) : by
haveI := sInf tas; haveI := sInf tbs;
exact @Continuous _ _ _ tc fun p : X × Y => f p.1 p.2 := by
have hX := continuous_sInf_dom hX continuous_id
have hY := continuous_sInf_dom hY continuous_id
have h_continuous_id := @Continuous.prod_map _ _ _ _ tX tY (sInf tas) (sInf tbs) _ _ hX hY
exact @Continuous.comp _ _ _ (id _) (id _) _ _ _ hf h_continuous_id
#align continuous_Inf_dom₂ continuous_sInf_dom₂
theorem Filter.Eventually.prod_inl_nhds {p : X → Prop} {x : X} (h : ∀ᶠ x in 𝓝 x, p x) (y : Y) :
∀ᶠ x in 𝓝 (x, y), p (x : X × Y).1 :=
continuousAt_fst h
#align filter.eventually.prod_inl_nhds Filter.Eventually.prod_inl_nhds
theorem Filter.Eventually.prod_inr_nhds {p : Y → Prop} {y : Y} (h : ∀ᶠ x in 𝓝 y, p x) (x : X) :
∀ᶠ x in 𝓝 (x, y), p (x : X × Y).2 :=
continuousAt_snd h
#align filter.eventually.prod_inr_nhds Filter.Eventually.prod_inr_nhds
theorem Filter.Eventually.prod_mk_nhds {px : X → Prop} {x} (hx : ∀ᶠ x in 𝓝 x, px x) {py : Y → Prop}
{y} (hy : ∀ᶠ y in 𝓝 y, py y) : ∀ᶠ p in 𝓝 (x, y), px (p : X × Y).1 ∧ py p.2 :=
(hx.prod_inl_nhds y).and (hy.prod_inr_nhds x)
#align filter.eventually.prod_mk_nhds Filter.Eventually.prod_mk_nhds
theorem continuous_swap : Continuous (Prod.swap : X × Y → Y × X) :=
continuous_snd.prod_mk continuous_fst
#align continuous_swap continuous_swap
lemma isClosedMap_swap : IsClosedMap (Prod.swap : X × Y → Y × X) := fun s hs ↦ by
rw [image_swap_eq_preimage_swap]
exact hs.preimage continuous_swap
theorem Continuous.uncurry_left {f : X → Y → Z} (x : X) (h : Continuous (uncurry f)) :
Continuous (f x) :=
h.comp (Continuous.Prod.mk _)
#align continuous_uncurry_left Continuous.uncurry_left
theorem Continuous.uncurry_right {f : X → Y → Z} (y : Y) (h : Continuous (uncurry f)) :
Continuous fun a => f a y :=
h.comp (Continuous.Prod.mk_left _)
#align continuous_uncurry_right Continuous.uncurry_right
-- 2024-03-09
@[deprecated] alias continuous_uncurry_left := Continuous.uncurry_left
@[deprecated] alias continuous_uncurry_right := Continuous.uncurry_right
theorem continuous_curry {g : X × Y → Z} (x : X) (h : Continuous g) : Continuous (curry g x) :=
Continuous.uncurry_left x h
#align continuous_curry continuous_curry
theorem IsOpen.prod {s : Set X} {t : Set Y} (hs : IsOpen s) (ht : IsOpen t) : IsOpen (s ×ˢ t) :=
(hs.preimage continuous_fst).inter (ht.preimage continuous_snd)
#align is_open.prod IsOpen.prod
-- Porting note (#11215): TODO: Lean fails to find `t₁` and `t₂` by unification
theorem nhds_prod_eq {x : X} {y : Y} : 𝓝 (x, y) = 𝓝 x ×ˢ 𝓝 y := by
dsimp only [SProd.sprod]
rw [Filter.prod, instTopologicalSpaceProd, nhds_inf (t₁ := TopologicalSpace.induced Prod.fst _)
(t₂ := TopologicalSpace.induced Prod.snd _), nhds_induced, nhds_induced]
#align nhds_prod_eq nhds_prod_eq
-- Porting note: moved from `Topology.ContinuousOn`
theorem nhdsWithin_prod_eq (x : X) (y : Y) (s : Set X) (t : Set Y) :
𝓝[s ×ˢ t] (x, y) = 𝓝[s] x ×ˢ 𝓝[t] y := by
simp only [nhdsWithin, nhds_prod_eq, ← prod_inf_prod, prod_principal_principal]
#align nhds_within_prod_eq nhdsWithin_prod_eq
#noalign continuous_uncurry_of_discrete_topology
theorem mem_nhds_prod_iff {x : X} {y : Y} {s : Set (X × Y)} :
s ∈ 𝓝 (x, y) ↔ ∃ u ∈ 𝓝 x, ∃ v ∈ 𝓝 y, u ×ˢ v ⊆ s := by rw [nhds_prod_eq, mem_prod_iff]
#align mem_nhds_prod_iff mem_nhds_prod_iff
theorem mem_nhdsWithin_prod_iff {x : X} {y : Y} {s : Set (X × Y)} {tx : Set X} {ty : Set Y} :
s ∈ 𝓝[tx ×ˢ ty] (x, y) ↔ ∃ u ∈ 𝓝[tx] x, ∃ v ∈ 𝓝[ty] y, u ×ˢ v ⊆ s := by
rw [nhdsWithin_prod_eq, mem_prod_iff]
-- Porting note: moved up
theorem Filter.HasBasis.prod_nhds {ιX ιY : Type*} {px : ιX → Prop} {py : ιY → Prop}
{sx : ιX → Set X} {sy : ιY → Set Y} {x : X} {y : Y} (hx : (𝓝 x).HasBasis px sx)
(hy : (𝓝 y).HasBasis py sy) :
(𝓝 (x, y)).HasBasis (fun i : ιX × ιY => px i.1 ∧ py i.2) fun i => sx i.1 ×ˢ sy i.2 := by
rw [nhds_prod_eq]
exact hx.prod hy
#align filter.has_basis.prod_nhds Filter.HasBasis.prod_nhds
-- Porting note: moved up
theorem Filter.HasBasis.prod_nhds' {ιX ιY : Type*} {pX : ιX → Prop} {pY : ιY → Prop}
{sx : ιX → Set X} {sy : ιY → Set Y} {p : X × Y} (hx : (𝓝 p.1).HasBasis pX sx)
(hy : (𝓝 p.2).HasBasis pY sy) :
(𝓝 p).HasBasis (fun i : ιX × ιY => pX i.1 ∧ pY i.2) fun i => sx i.1 ×ˢ sy i.2 :=
hx.prod_nhds hy
#align filter.has_basis.prod_nhds' Filter.HasBasis.prod_nhds'
theorem mem_nhds_prod_iff' {x : X} {y : Y} {s : Set (X × Y)} :
s ∈ 𝓝 (x, y) ↔ ∃ u v, IsOpen u ∧ x ∈ u ∧ IsOpen v ∧ y ∈ v ∧ u ×ˢ v ⊆ s :=
((nhds_basis_opens x).prod_nhds (nhds_basis_opens y)).mem_iff.trans <| by
simp only [Prod.exists, and_comm, and_assoc, and_left_comm]
#align mem_nhds_prod_iff' mem_nhds_prod_iff'
theorem Prod.tendsto_iff {X} (seq : X → Y × Z) {f : Filter X} (p : Y × Z) :
Tendsto seq f (𝓝 p) ↔
Tendsto (fun n => (seq n).fst) f (𝓝 p.fst) ∧ Tendsto (fun n => (seq n).snd) f (𝓝 p.snd) := by
rw [nhds_prod_eq, Filter.tendsto_prod_iff']
#align prod.tendsto_iff Prod.tendsto_iff
instance [DiscreteTopology X] [DiscreteTopology Y] : DiscreteTopology (X × Y) :=
discreteTopology_iff_nhds.2 fun (a, b) => by
rw [nhds_prod_eq, nhds_discrete X, nhds_discrete Y, prod_pure_pure]
theorem prod_mem_nhds_iff {s : Set X} {t : Set Y} {x : X} {y : Y} :
s ×ˢ t ∈ 𝓝 (x, y) ↔ s ∈ 𝓝 x ∧ t ∈ 𝓝 y := by rw [nhds_prod_eq, prod_mem_prod_iff]
#align prod_mem_nhds_iff prod_mem_nhds_iff
theorem prod_mem_nhds {s : Set X} {t : Set Y} {x : X} {y : Y} (hx : s ∈ 𝓝 x) (hy : t ∈ 𝓝 y) :
s ×ˢ t ∈ 𝓝 (x, y) :=
prod_mem_nhds_iff.2 ⟨hx, hy⟩
#align prod_mem_nhds prod_mem_nhds
theorem isOpen_setOf_disjoint_nhds_nhds : IsOpen { p : X × X | Disjoint (𝓝 p.1) (𝓝 p.2) } := by
simp only [isOpen_iff_mem_nhds, Prod.forall, mem_setOf_eq]
intro x y h
obtain ⟨U, hU, V, hV, hd⟩ := ((nhds_basis_opens x).disjoint_iff (nhds_basis_opens y)).mp h
exact mem_nhds_prod_iff'.mpr ⟨U, V, hU.2, hU.1, hV.2, hV.1, fun ⟨x', y'⟩ ⟨hx', hy'⟩ =>
disjoint_of_disjoint_of_mem hd (hU.2.mem_nhds hx') (hV.2.mem_nhds hy')⟩
#align is_open_set_of_disjoint_nhds_nhds isOpen_setOf_disjoint_nhds_nhds
theorem Filter.Eventually.prod_nhds {p : X → Prop} {q : Y → Prop} {x : X} {y : Y}
(hx : ∀ᶠ x in 𝓝 x, p x) (hy : ∀ᶠ y in 𝓝 y, q y) : ∀ᶠ z : X × Y in 𝓝 (x, y), p z.1 ∧ q z.2 :=
prod_mem_nhds hx hy
#align filter.eventually.prod_nhds Filter.Eventually.prod_nhds
theorem nhds_swap (x : X) (y : Y) : 𝓝 (x, y) = (𝓝 (y, x)).map Prod.swap := by
rw [nhds_prod_eq, Filter.prod_comm, nhds_prod_eq]; rfl
#align nhds_swap nhds_swap
theorem Filter.Tendsto.prod_mk_nhds {γ} {x : X} {y : Y} {f : Filter γ} {mx : γ → X} {my : γ → Y}
(hx : Tendsto mx f (𝓝 x)) (hy : Tendsto my f (𝓝 y)) :
Tendsto (fun c => (mx c, my c)) f (𝓝 (x, y)) := by
rw [nhds_prod_eq]; exact Filter.Tendsto.prod_mk hx hy
#align filter.tendsto.prod_mk_nhds Filter.Tendsto.prod_mk_nhds
theorem Filter.Eventually.curry_nhds {p : X × Y → Prop} {x : X} {y : Y}
(h : ∀ᶠ x in 𝓝 (x, y), p x) : ∀ᶠ x' in 𝓝 x, ∀ᶠ y' in 𝓝 y, p (x', y') := by
rw [nhds_prod_eq] at h
exact h.curry
#align filter.eventually.curry_nhds Filter.Eventually.curry_nhds
@[fun_prop]
theorem ContinuousAt.prod {f : X → Y} {g : X → Z} {x : X} (hf : ContinuousAt f x)
(hg : ContinuousAt g x) : ContinuousAt (fun x => (f x, g x)) x :=
hf.prod_mk_nhds hg
#align continuous_at.prod ContinuousAt.prod
theorem ContinuousAt.prod_map {f : X → Z} {g : Y → W} {p : X × Y} (hf : ContinuousAt f p.fst)
(hg : ContinuousAt g p.snd) : ContinuousAt (fun p : X × Y => (f p.1, g p.2)) p :=
hf.fst''.prod hg.snd''
#align continuous_at.prod_map ContinuousAt.prod_map
theorem ContinuousAt.prod_map' {f : X → Z} {g : Y → W} {x : X} {y : Y} (hf : ContinuousAt f x)
(hg : ContinuousAt g y) : ContinuousAt (fun p : X × Y => (f p.1, g p.2)) (x, y) :=
hf.fst'.prod hg.snd'
#align continuous_at.prod_map' ContinuousAt.prod_map'
theorem ContinuousAt.comp₂ {f : Y × Z → W} {g : X → Y} {h : X → Z} {x : X}
(hf : ContinuousAt f (g x, h x)) (hg : ContinuousAt g x) (hh : ContinuousAt h x) :
ContinuousAt (fun x ↦ f (g x, h x)) x :=
ContinuousAt.comp hf (hg.prod hh)
| Mathlib/Topology/Constructions.lean | 663 | 667 | theorem ContinuousAt.comp₂_of_eq {f : Y × Z → W} {g : X → Y} {h : X → Z} {x : X} {y : Y × Z}
(hf : ContinuousAt f y) (hg : ContinuousAt g x) (hh : ContinuousAt h x) (e : (g x, h x) = y) :
ContinuousAt (fun x ↦ f (g x, h x)) x := by |
rw [← e] at hf
exact hf.comp₂ hg hh
|
import Mathlib.LinearAlgebra.TensorProduct.Graded.External
import Mathlib.RingTheory.GradedAlgebra.Basic
import Mathlib.GroupTheory.GroupAction.Ring
suppress_compilation
open scoped TensorProduct
variable {R ι A B : Type*}
variable [CommSemiring ι] [Module ι (Additive ℤˣ)] [DecidableEq ι]
variable [CommRing R] [Ring A] [Ring B] [Algebra R A] [Algebra R B]
variable (𝒜 : ι → Submodule R A) (ℬ : ι → Submodule R B)
variable [GradedAlgebra 𝒜] [GradedAlgebra ℬ]
open DirectSum
variable (R) in
@[nolint unusedArguments]
def GradedTensorProduct
(𝒜 : ι → Submodule R A) (ℬ : ι → Submodule R B)
[GradedAlgebra 𝒜] [GradedAlgebra ℬ] :
Type _ :=
A ⊗[R] B
namespace GradedTensorProduct
open TensorProduct
@[inherit_doc GradedTensorProduct]
scoped[TensorProduct] notation:100 𝒜 " ᵍ⊗[" R "] " ℬ:100 => GradedTensorProduct R 𝒜 ℬ
instance instAddCommGroupWithOne : AddCommGroupWithOne (𝒜 ᵍ⊗[R] ℬ) :=
Algebra.TensorProduct.instAddCommGroupWithOne
instance : Module R (𝒜 ᵍ⊗[R] ℬ) := TensorProduct.leftModule
variable (R) in
def of : A ⊗[R] B ≃ₗ[R] 𝒜 ᵍ⊗[R] ℬ := LinearEquiv.refl _ _
@[simp]
theorem of_one : of R 𝒜 ℬ 1 = 1 := rfl
@[simp]
theorem of_symm_one : (of R 𝒜 ℬ).symm 1 = 1 := rfl
-- for dsimp
@[simp, nolint simpNF]
theorem of_symm_of (x : A ⊗[R] B) : (of R 𝒜 ℬ).symm (of R 𝒜 ℬ x) = x := rfl
-- for dsimp
@[simp, nolint simpNF]
theorem symm_of_of (x : 𝒜 ᵍ⊗[R] ℬ) : of R 𝒜 ℬ ((of R 𝒜 ℬ).symm x) = x := rfl
@[ext]
theorem hom_ext {M} [AddCommMonoid M] [Module R M] ⦃f g : 𝒜 ᵍ⊗[R] ℬ →ₗ[R] M⦄
(h : f ∘ₗ of R 𝒜 ℬ = (g ∘ₗ of R 𝒜 ℬ : A ⊗[R] B →ₗ[R] M)) :
f = g :=
h
variable (R) {𝒜 ℬ} in
abbrev tmul (a : A) (b : B) : 𝒜 ᵍ⊗[R] ℬ := of R 𝒜 ℬ (a ⊗ₜ b)
@[inherit_doc]
notation:100 x " ᵍ⊗ₜ" y:100 => tmul _ x y
@[inherit_doc]
notation:100 x " ᵍ⊗ₜ[" R "] " y:100 => tmul R x y
variable (R) in
noncomputable def auxEquiv : (𝒜 ᵍ⊗[R] ℬ) ≃ₗ[R] (⨁ i, 𝒜 i) ⊗[R] (⨁ i, ℬ i) :=
let fA := (decomposeAlgEquiv 𝒜).toLinearEquiv
let fB := (decomposeAlgEquiv ℬ).toLinearEquiv
(of R 𝒜 ℬ).symm.trans (TensorProduct.congr fA fB)
theorem auxEquiv_tmul (a : A) (b : B) :
auxEquiv R 𝒜 ℬ (a ᵍ⊗ₜ b) = decompose 𝒜 a ⊗ₜ decompose ℬ b := rfl
theorem auxEquiv_one : auxEquiv R 𝒜 ℬ 1 = 1 := by
rw [← of_one, Algebra.TensorProduct.one_def, auxEquiv_tmul 𝒜 ℬ, DirectSum.decompose_one,
DirectSum.decompose_one, Algebra.TensorProduct.one_def]
theorem auxEquiv_symm_one : (auxEquiv R 𝒜 ℬ).symm 1 = 1 :=
(LinearEquiv.symm_apply_eq _).mpr (auxEquiv_one _ _).symm
noncomputable def mulHom : (𝒜 ᵍ⊗[R] ℬ) →ₗ[R] (𝒜 ᵍ⊗[R] ℬ) →ₗ[R] (𝒜 ᵍ⊗[R] ℬ) := by
letI fAB1 := auxEquiv R 𝒜 ℬ
have := ((gradedMul R (𝒜 ·) (ℬ ·)).compl₁₂ fAB1.toLinearMap fAB1.toLinearMap).compr₂
fAB1.symm.toLinearMap
exact this
theorem mulHom_apply (x y : 𝒜 ᵍ⊗[R] ℬ) :
mulHom 𝒜 ℬ x y
= (auxEquiv R 𝒜 ℬ).symm (gradedMul R (𝒜 ·) (ℬ ·) (auxEquiv R 𝒜 ℬ x) (auxEquiv R 𝒜 ℬ y)) :=
rfl
instance : Mul (𝒜 ᵍ⊗[R] ℬ) where mul x y := mulHom 𝒜 ℬ x y
theorem mul_def (x y : 𝒜 ᵍ⊗[R] ℬ) : x * y = mulHom 𝒜 ℬ x y := rfl
-- Before #8386 this was `@[simp]` but it times out when we try to apply it.
theorem auxEquiv_mul (x y : 𝒜 ᵍ⊗[R] ℬ) :
auxEquiv R 𝒜 ℬ (x * y) = gradedMul R (𝒜 ·) (ℬ ·) (auxEquiv R 𝒜 ℬ x) (auxEquiv R 𝒜 ℬ y) :=
LinearEquiv.eq_symm_apply _ |>.mp rfl
instance instMonoid : Monoid (𝒜 ᵍ⊗[R] ℬ) where
mul_one x := by
rw [mul_def, mulHom_apply, auxEquiv_one, gradedMul_one, LinearEquiv.symm_apply_apply]
one_mul x := by
rw [mul_def, mulHom_apply, auxEquiv_one, one_gradedMul, LinearEquiv.symm_apply_apply]
mul_assoc x y z := by
simp_rw [mul_def, mulHom_apply, LinearEquiv.apply_symm_apply]
rw [gradedMul_assoc]
instance instRing : Ring (𝒜 ᵍ⊗[R] ℬ) where
__ := instAddCommGroupWithOne 𝒜 ℬ
__ := instMonoid 𝒜 ℬ
right_distrib x y z := by simp_rw [mul_def, LinearMap.map_add₂]
left_distrib x y z := by simp_rw [mul_def, map_add]
mul_zero x := by simp_rw [mul_def, map_zero]
zero_mul x := by simp_rw [mul_def, LinearMap.map_zero₂]
theorem tmul_coe_mul_coe_tmul {j₁ i₂ : ι} (a₁ : A) (b₁ : ℬ j₁) (a₂ : 𝒜 i₂) (b₂ : B) :
(a₁ ᵍ⊗ₜ[R] (b₁ : B) * (a₂ : A) ᵍ⊗ₜ[R] b₂ : 𝒜 ᵍ⊗[R] ℬ) =
(-1 : ℤˣ)^(j₁ * i₂) • ((a₁ * a₂ : A) ᵍ⊗ₜ (b₁ * b₂ : B)) := by
dsimp only [mul_def, mulHom_apply, of_symm_of]
dsimp [auxEquiv, tmul]
erw [decompose_coe, decompose_coe]
simp_rw [← lof_eq_of R]
rw [tmul_of_gradedMul_of_tmul]
simp_rw [lof_eq_of R]
rw [LinearEquiv.symm_symm]
-- Note: #8386 had to specialize `map_smul` to `LinearEquiv.map_smul`
rw [@Units.smul_def _ _ (_) (_), zsmul_eq_smul_cast R, LinearEquiv.map_smul, map_smul,
← zsmul_eq_smul_cast R, ← @Units.smul_def _ _ (_) (_)]
rw [congr_symm_tmul]
dsimp
simp_rw [decompose_symm_mul, decompose_symm_of, Equiv.symm_apply_apply]
theorem tmul_zero_coe_mul_coe_tmul {i₂ : ι} (a₁ : A) (b₁ : ℬ 0) (a₂ : 𝒜 i₂) (b₂ : B) :
(a₁ ᵍ⊗ₜ[R] (b₁ : B) * (a₂ : A) ᵍ⊗ₜ[R] b₂ : 𝒜 ᵍ⊗[R] ℬ) =
((a₁ * a₂ : A) ᵍ⊗ₜ (b₁ * b₂ : B)) := by
rw [tmul_coe_mul_coe_tmul, zero_mul, uzpow_zero, one_smul]
| Mathlib/LinearAlgebra/TensorProduct/Graded/Internal.lean | 207 | 210 | theorem tmul_coe_mul_zero_coe_tmul {j₁ : ι} (a₁ : A) (b₁ : ℬ j₁) (a₂ : 𝒜 0) (b₂ : B) :
(a₁ ᵍ⊗ₜ[R] (b₁ : B) * (a₂ : A) ᵍ⊗ₜ[R] b₂ : 𝒜 ᵍ⊗[R] ℬ) =
((a₁ * a₂ : A) ᵍ⊗ₜ (b₁ * b₂ : B)) := by |
rw [tmul_coe_mul_coe_tmul, mul_zero, uzpow_zero, one_smul]
|
import Mathlib.Algebra.Group.Defs
#align_import algebra.invertible from "leanprover-community/mathlib"@"722b3b152ddd5e0cf21c0a29787c76596cb6b422"
assert_not_exists MonoidWithZero
assert_not_exists DenselyOrdered
universe u
variable {α : Type u}
class Invertible [Mul α] [One α] (a : α) : Type u where
invOf : α
invOf_mul_self : invOf * a = 1
mul_invOf_self : a * invOf = 1
#align invertible Invertible
prefix:max
"⅟" =>-- This notation has the same precedence as `Inv.inv`.
Invertible.invOf
@[simp]
theorem invOf_mul_self' [Mul α] [One α] (a : α) {_ : Invertible a} : ⅟ a * a = 1 :=
Invertible.invOf_mul_self
theorem invOf_mul_self [Mul α] [One α] (a : α) [Invertible a] : ⅟ a * a = 1 :=
Invertible.invOf_mul_self
#align inv_of_mul_self invOf_mul_self
@[simp]
theorem mul_invOf_self' [Mul α] [One α] (a : α) {_ : Invertible a} : a * ⅟ a = 1 :=
Invertible.mul_invOf_self
theorem mul_invOf_self [Mul α] [One α] (a : α) [Invertible a] : a * ⅟ a = 1 :=
Invertible.mul_invOf_self
#align mul_inv_of_self mul_invOf_self
@[simp]
theorem invOf_mul_self_assoc' [Monoid α] (a b : α) {_ : Invertible a} : ⅟ a * (a * b) = b := by
rw [← mul_assoc, invOf_mul_self, one_mul]
theorem invOf_mul_self_assoc [Monoid α] (a b : α) [Invertible a] : ⅟ a * (a * b) = b := by
rw [← mul_assoc, invOf_mul_self, one_mul]
#align inv_of_mul_self_assoc invOf_mul_self_assoc
@[simp]
theorem mul_invOf_self_assoc' [Monoid α] (a b : α) {_ : Invertible a} : a * (⅟ a * b) = b := by
rw [← mul_assoc, mul_invOf_self, one_mul]
theorem mul_invOf_self_assoc [Monoid α] (a b : α) [Invertible a] : a * (⅟ a * b) = b := by
rw [← mul_assoc, mul_invOf_self, one_mul]
#align mul_inv_of_self_assoc mul_invOf_self_assoc
@[simp]
theorem mul_invOf_mul_self_cancel' [Monoid α] (a b : α) {_ : Invertible b} : a * ⅟ b * b = a := by
simp [mul_assoc]
theorem mul_invOf_mul_self_cancel [Monoid α] (a b : α) [Invertible b] : a * ⅟ b * b = a := by
simp [mul_assoc]
#align mul_inv_of_mul_self_cancel mul_invOf_mul_self_cancel
@[simp]
theorem mul_mul_invOf_self_cancel' [Monoid α] (a b : α) {_ : Invertible b} : a * b * ⅟ b = a := by
simp [mul_assoc]
theorem mul_mul_invOf_self_cancel [Monoid α] (a b : α) [Invertible b] : a * b * ⅟ b = a := by
simp [mul_assoc]
#align mul_mul_inv_of_self_cancel mul_mul_invOf_self_cancel
theorem invOf_eq_right_inv [Monoid α] {a b : α} [Invertible a] (hac : a * b = 1) : ⅟ a = b :=
left_inv_eq_right_inv (invOf_mul_self _) hac
#align inv_of_eq_right_inv invOf_eq_right_inv
theorem invOf_eq_left_inv [Monoid α] {a b : α} [Invertible a] (hac : b * a = 1) : ⅟ a = b :=
(left_inv_eq_right_inv hac (mul_invOf_self _)).symm
#align inv_of_eq_left_inv invOf_eq_left_inv
theorem invertible_unique {α : Type u} [Monoid α] (a b : α) [Invertible a] [Invertible b]
(h : a = b) : ⅟ a = ⅟ b := by
apply invOf_eq_right_inv
rw [h, mul_invOf_self]
#align invertible_unique invertible_unique
instance Invertible.subsingleton [Monoid α] (a : α) : Subsingleton (Invertible a) :=
⟨fun ⟨b, hba, hab⟩ ⟨c, _, hac⟩ => by
congr
exact left_inv_eq_right_inv hba hac⟩
#align invertible.subsingleton Invertible.subsingleton
@[congr]
theorem Invertible.congr [Monoid α] (a b : α) [Invertible a] [Invertible b] (h : a = b) :
⅟a = ⅟b := by subst h; congr; apply Subsingleton.allEq
def Invertible.copy' [MulOneClass α] {r : α} (hr : Invertible r) (s : α) (si : α) (hs : s = r)
(hsi : si = ⅟ r) : Invertible s where
invOf := si
invOf_mul_self := by rw [hs, hsi, invOf_mul_self]
mul_invOf_self := by rw [hs, hsi, mul_invOf_self]
#align invertible.copy' Invertible.copy'
abbrev Invertible.copy [MulOneClass α] {r : α} (hr : Invertible r) (s : α) (hs : s = r) :
Invertible s :=
hr.copy' _ _ hs rfl
#align invertible.copy Invertible.copy
def invertibleOfGroup [Group α] (a : α) : Invertible a :=
⟨a⁻¹, inv_mul_self a, mul_inv_self a⟩
#align invertible_of_group invertibleOfGroup
@[simp]
theorem invOf_eq_group_inv [Group α] (a : α) [Invertible a] : ⅟ a = a⁻¹ :=
invOf_eq_right_inv (mul_inv_self a)
#align inv_of_eq_group_inv invOf_eq_group_inv
def invertibleOne [Monoid α] : Invertible (1 : α) :=
⟨1, mul_one _, one_mul _⟩
#align invertible_one invertibleOne
@[simp]
theorem invOf_one' [Monoid α] {_ : Invertible (1 : α)} : ⅟ (1 : α) = 1 :=
invOf_eq_right_inv (mul_one _)
theorem invOf_one [Monoid α] [Invertible (1 : α)] : ⅟ (1 : α) = 1 :=
invOf_eq_right_inv (mul_one _)
#align inv_of_one invOf_one
instance invertibleInvOf [One α] [Mul α] {a : α} [Invertible a] : Invertible (⅟ a) :=
⟨a, mul_invOf_self a, invOf_mul_self a⟩
#align invertible_inv_of invertibleInvOf
@[simp]
theorem invOf_invOf [Monoid α] (a : α) [Invertible a] [Invertible (⅟ a)] : ⅟ (⅟ a) = a :=
invOf_eq_right_inv (invOf_mul_self _)
#align inv_of_inv_of invOf_invOf
@[simp]
theorem invOf_inj [Monoid α] {a b : α} [Invertible a] [Invertible b] : ⅟ a = ⅟ b ↔ a = b :=
⟨invertible_unique _ _, invertible_unique _ _⟩
#align inv_of_inj invOf_inj
def invertibleMul [Monoid α] (a b : α) [Invertible a] [Invertible b] : Invertible (a * b) :=
⟨⅟ b * ⅟ a, by simp [← mul_assoc], by simp [← mul_assoc]⟩
#align invertible_mul invertibleMul
@[simp]
theorem invOf_mul [Monoid α] (a b : α) [Invertible a] [Invertible b] [Invertible (a * b)] :
⅟ (a * b) = ⅟ b * ⅟ a :=
invOf_eq_right_inv (by simp [← mul_assoc])
#align inv_of_mul invOf_mul
abbrev Invertible.mul [Monoid α] {a b : α} (_ : Invertible a) (_ : Invertible b) :
Invertible (a * b) :=
invertibleMul _ _
#align invertible.mul Invertible.mul
section
variable [Monoid α] {a b c : α} [Invertible c]
variable (c) in
theorem mul_right_inj_of_invertible : a * c = b * c ↔ a = b :=
⟨fun h => by simpa using congr_arg (· * ⅟c) h, congr_arg (· * _)⟩
variable (c) in
theorem mul_left_inj_of_invertible : c * a = c * b ↔ a = b :=
⟨fun h => by simpa using congr_arg (⅟c * ·) h, congr_arg (_ * ·)⟩
theorem invOf_mul_eq_iff_eq_mul_left : ⅟c * a = b ↔ a = c * b := by
rw [← mul_left_inj_of_invertible (c := c), mul_invOf_self_assoc]
theorem mul_left_eq_iff_eq_invOf_mul : c * a = b ↔ a = ⅟c * b := by
rw [← mul_left_inj_of_invertible (c := ⅟c), invOf_mul_self_assoc]
theorem mul_invOf_eq_iff_eq_mul_right : a * ⅟c = b ↔ a = b * c := by
rw [← mul_right_inj_of_invertible (c := c), mul_invOf_mul_self_cancel]
| Mathlib/Algebra/Group/Invertible/Defs.lean | 262 | 263 | theorem mul_right_eq_iff_eq_mul_invOf : a * c = b ↔ a = b * ⅟c := by |
rw [← mul_right_inj_of_invertible (c := ⅟c), mul_mul_invOf_self_cancel]
|
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
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⟩⟩
#align set.mem_dite_empty_left Set.mem_dite_empty_left
@[simp]
theorem mem_ite_empty_left (p : Prop) [Decidable p] (t : Set α) (x : α) :
x ∈ ite p ∅ t ↔ ¬p ∧ x ∈ t :=
(mem_dite_empty_left p (fun _ => t) x).trans (by simp)
#align set.mem_ite_empty_left Set.mem_ite_empty_left
protected def ite (t s s' : Set α) : Set α :=
s ∩ t ∪ s' \ t
#align set.ite Set.ite
@[simp]
theorem ite_inter_self (t s s' : Set α) : t.ite s s' ∩ t = s ∩ t := by
rw [Set.ite, union_inter_distrib_right, diff_inter_self, inter_assoc, inter_self, union_empty]
#align set.ite_inter_self Set.ite_inter_self
@[simp]
theorem ite_compl (t s s' : Set α) : tᶜ.ite s s' = t.ite s' s := by
rw [Set.ite, Set.ite, diff_compl, union_comm, diff_eq]
#align set.ite_compl Set.ite_compl
@[simp]
theorem ite_inter_compl_self (t s s' : Set α) : t.ite s s' ∩ tᶜ = s' ∩ tᶜ := by
rw [← ite_compl, ite_inter_self]
#align set.ite_inter_compl_self Set.ite_inter_compl_self
@[simp]
theorem ite_diff_self (t s s' : Set α) : t.ite s s' \ t = s' \ t :=
ite_inter_compl_self t s s'
#align set.ite_diff_self Set.ite_diff_self
@[simp]
theorem ite_same (t s : Set α) : t.ite s s = s :=
inter_union_diff _ _
#align set.ite_same Set.ite_same
@[simp]
theorem ite_left (s t : Set α) : s.ite s t = s ∪ t := by simp [Set.ite]
#align set.ite_left Set.ite_left
@[simp]
theorem ite_right (s t : Set α) : s.ite t s = t ∩ s := by simp [Set.ite]
#align set.ite_right Set.ite_right
@[simp]
theorem ite_empty (s s' : Set α) : Set.ite ∅ s s' = s' := by simp [Set.ite]
#align set.ite_empty Set.ite_empty
@[simp]
theorem ite_univ (s s' : Set α) : Set.ite univ s s' = s := by simp [Set.ite]
#align set.ite_univ Set.ite_univ
@[simp]
theorem ite_empty_left (t s : Set α) : t.ite ∅ s = s \ t := by simp [Set.ite]
#align set.ite_empty_left Set.ite_empty_left
@[simp]
theorem ite_empty_right (t s : Set α) : t.ite s ∅ = s ∩ t := by simp [Set.ite]
#align set.ite_empty_right Set.ite_empty_right
theorem ite_mono (t : Set α) {s₁ s₁' s₂ s₂' : Set α} (h : s₁ ⊆ s₂) (h' : s₁' ⊆ s₂') :
t.ite s₁ s₁' ⊆ t.ite s₂ s₂' :=
union_subset_union (inter_subset_inter_left _ h) (inter_subset_inter_left _ h')
#align set.ite_mono Set.ite_mono
theorem ite_subset_union (t s s' : Set α) : t.ite s s' ⊆ s ∪ s' :=
union_subset_union inter_subset_left diff_subset
#align set.ite_subset_union Set.ite_subset_union
theorem inter_subset_ite (t s s' : Set α) : s ∩ s' ⊆ t.ite s s' :=
ite_same t (s ∩ s') ▸ ite_mono _ inter_subset_left inter_subset_right
#align set.inter_subset_ite Set.inter_subset_ite
theorem ite_inter_inter (t s₁ s₂ s₁' s₂' : Set α) :
t.ite (s₁ ∩ s₂) (s₁' ∩ s₂') = t.ite s₁ s₁' ∩ t.ite s₂ s₂' := by
ext x
simp only [Set.ite, Set.mem_inter_iff, Set.mem_diff, Set.mem_union]
tauto
#align set.ite_inter_inter Set.ite_inter_inter
theorem ite_inter (t s₁ s₂ s : Set α) : t.ite (s₁ ∩ s) (s₂ ∩ s) = t.ite s₁ s₂ ∩ s := by
rw [ite_inter_inter, ite_same]
#align set.ite_inter Set.ite_inter
theorem ite_inter_of_inter_eq (t : Set α) {s₁ s₂ s : Set α} (h : s₁ ∩ s = s₂ ∩ s) :
t.ite s₁ s₂ ∩ s = s₁ ∩ s := by rw [← ite_inter, ← h, ite_same]
#align set.ite_inter_of_inter_eq Set.ite_inter_of_inter_eq
theorem subset_ite {t s s' u : Set α} : u ⊆ t.ite s s' ↔ u ∩ t ⊆ s ∧ u \ t ⊆ s' := by
simp only [subset_def, ← forall_and]
refine forall_congr' fun x => ?_
by_cases hx : x ∈ t <;> simp [*, Set.ite]
#align set.subset_ite Set.subset_ite
theorem ite_eq_of_subset_left (t : Set α) {s₁ s₂ : Set α} (h : s₁ ⊆ s₂) :
t.ite s₁ s₂ = s₁ ∪ (s₂ \ t) := by
ext x
by_cases hx : x ∈ t <;> simp [*, Set.ite, or_iff_right_of_imp (@h x)]
theorem ite_eq_of_subset_right (t : Set α) {s₁ s₂ : Set α} (h : s₂ ⊆ s₁) :
t.ite s₁ s₂ = (s₁ ∩ t) ∪ s₂ := by
ext x
by_cases hx : x ∈ t <;> simp [*, Set.ite, or_iff_left_of_imp (@h x)]
section Preorder
variable [Preorder α] [Preorder β] {f : α → β}
-- Porting note:
-- If we decide we want `Elem` to semireducible rather than reducible, we will need:
-- instance : Preorder (↑s) := Subtype.instPreorderSubtype _
-- here, along with appropriate lemmas.
theorem monotoneOn_iff_monotone : MonotoneOn f s ↔
Monotone fun a : s => f a := by
simp [Monotone, MonotoneOn]
#align set.monotone_on_iff_monotone Set.monotoneOn_iff_monotone
| Mathlib/Data/Set/Basic.lean | 2,372 | 2,374 | theorem antitoneOn_iff_antitone : AntitoneOn f s ↔
Antitone fun a : s => f a := by |
simp [Antitone, AntitoneOn]
|
import Mathlib.Algebra.BigOperators.Fin
import Mathlib.Algebra.Order.BigOperators.Group.Finset
import Mathlib.Data.Finset.Sort
import Mathlib.Data.Set.Subsingleton
#align_import combinatorics.composition from "leanprover-community/mathlib"@"92ca63f0fb391a9ca5f22d2409a6080e786d99f7"
open List
variable {n : ℕ}
@[ext]
structure Composition (n : ℕ) where
blocks : List ℕ
blocks_pos : ∀ {i}, i ∈ blocks → 0 < i
blocks_sum : blocks.sum = n
#align composition Composition
@[ext]
structure CompositionAsSet (n : ℕ) where
boundaries : Finset (Fin n.succ)
zero_mem : (0 : Fin n.succ) ∈ boundaries
getLast_mem : Fin.last n ∈ boundaries
#align composition_as_set CompositionAsSet
instance {n : ℕ} : Inhabited (CompositionAsSet n) :=
⟨⟨Finset.univ, Finset.mem_univ _, Finset.mem_univ _⟩⟩
namespace Composition
variable (c : Composition n)
instance (n : ℕ) : ToString (Composition n) :=
⟨fun c => toString c.blocks⟩
abbrev length : ℕ :=
c.blocks.length
#align composition.length Composition.length
theorem blocks_length : c.blocks.length = c.length :=
rfl
#align composition.blocks_length Composition.blocks_length
def blocksFun : Fin c.length → ℕ := c.blocks.get
#align composition.blocks_fun Composition.blocksFun
theorem ofFn_blocksFun : ofFn c.blocksFun = c.blocks :=
ofFn_get _
#align composition.of_fn_blocks_fun Composition.ofFn_blocksFun
theorem sum_blocksFun : ∑ i, c.blocksFun i = n := by
conv_rhs => rw [← c.blocks_sum, ← ofFn_blocksFun, sum_ofFn]
#align composition.sum_blocks_fun Composition.sum_blocksFun
theorem blocksFun_mem_blocks (i : Fin c.length) : c.blocksFun i ∈ c.blocks :=
get_mem _ _ _
#align composition.blocks_fun_mem_blocks Composition.blocksFun_mem_blocks
@[simp]
theorem one_le_blocks {i : ℕ} (h : i ∈ c.blocks) : 1 ≤ i :=
c.blocks_pos h
#align composition.one_le_blocks Composition.one_le_blocks
@[simp]
theorem one_le_blocks' {i : ℕ} (h : i < c.length) : 1 ≤ c.blocks.get ⟨i, h⟩ :=
c.one_le_blocks (get_mem (blocks c) i h)
#align composition.one_le_blocks' Composition.one_le_blocks'
@[simp]
theorem blocks_pos' (i : ℕ) (h : i < c.length) : 0 < c.blocks.get ⟨i, h⟩ :=
c.one_le_blocks' h
#align composition.blocks_pos' Composition.blocks_pos'
theorem one_le_blocksFun (i : Fin c.length) : 1 ≤ c.blocksFun i :=
c.one_le_blocks (c.blocksFun_mem_blocks i)
#align composition.one_le_blocks_fun Composition.one_le_blocksFun
theorem length_le : c.length ≤ n := by
conv_rhs => rw [← c.blocks_sum]
exact length_le_sum_of_one_le _ fun i hi => c.one_le_blocks hi
#align composition.length_le Composition.length_le
theorem length_pos_of_pos (h : 0 < n) : 0 < c.length := by
apply length_pos_of_sum_pos
convert h
exact c.blocks_sum
#align composition.length_pos_of_pos Composition.length_pos_of_pos
def sizeUpTo (i : ℕ) : ℕ :=
(c.blocks.take i).sum
#align composition.size_up_to Composition.sizeUpTo
@[simp]
theorem sizeUpTo_zero : c.sizeUpTo 0 = 0 := by simp [sizeUpTo]
#align composition.size_up_to_zero Composition.sizeUpTo_zero
theorem sizeUpTo_ofLength_le (i : ℕ) (h : c.length ≤ i) : c.sizeUpTo i = n := by
dsimp [sizeUpTo]
convert c.blocks_sum
exact take_all_of_le h
#align composition.size_up_to_of_length_le Composition.sizeUpTo_ofLength_le
@[simp]
theorem sizeUpTo_length : c.sizeUpTo c.length = n :=
c.sizeUpTo_ofLength_le c.length le_rfl
#align composition.size_up_to_length Composition.sizeUpTo_length
theorem sizeUpTo_le (i : ℕ) : c.sizeUpTo i ≤ n := by
conv_rhs => rw [← c.blocks_sum, ← sum_take_add_sum_drop _ i]
exact Nat.le_add_right _ _
#align composition.size_up_to_le Composition.sizeUpTo_le
theorem sizeUpTo_succ {i : ℕ} (h : i < c.length) :
c.sizeUpTo (i + 1) = c.sizeUpTo i + c.blocks.get ⟨i, h⟩ := by
simp only [sizeUpTo]
rw [sum_take_succ _ _ h]
#align composition.size_up_to_succ Composition.sizeUpTo_succ
theorem sizeUpTo_succ' (i : Fin c.length) :
c.sizeUpTo ((i : ℕ) + 1) = c.sizeUpTo i + c.blocksFun i :=
c.sizeUpTo_succ i.2
#align composition.size_up_to_succ' Composition.sizeUpTo_succ'
theorem sizeUpTo_strict_mono {i : ℕ} (h : i < c.length) : c.sizeUpTo i < c.sizeUpTo (i + 1) := by
rw [c.sizeUpTo_succ h]
simp
#align composition.size_up_to_strict_mono Composition.sizeUpTo_strict_mono
theorem monotone_sizeUpTo : Monotone c.sizeUpTo :=
monotone_sum_take _
#align composition.monotone_size_up_to Composition.monotone_sizeUpTo
def boundary : Fin (c.length + 1) ↪o Fin (n + 1) :=
(OrderEmbedding.ofStrictMono fun i => ⟨c.sizeUpTo i, Nat.lt_succ_of_le (c.sizeUpTo_le i)⟩) <|
Fin.strictMono_iff_lt_succ.2 fun ⟨_, hi⟩ => c.sizeUpTo_strict_mono hi
#align composition.boundary Composition.boundary
@[simp]
theorem boundary_zero : c.boundary 0 = 0 := by simp [boundary, Fin.ext_iff]
#align composition.boundary_zero Composition.boundary_zero
@[simp]
theorem boundary_last : c.boundary (Fin.last c.length) = Fin.last n := by
simp [boundary, Fin.ext_iff]
#align composition.boundary_last Composition.boundary_last
def boundaries : Finset (Fin (n + 1)) :=
Finset.univ.map c.boundary.toEmbedding
#align composition.boundaries Composition.boundaries
theorem card_boundaries_eq_succ_length : c.boundaries.card = c.length + 1 := by simp [boundaries]
#align composition.card_boundaries_eq_succ_length Composition.card_boundaries_eq_succ_length
def toCompositionAsSet : CompositionAsSet n where
boundaries := c.boundaries
zero_mem := by
simp only [boundaries, Finset.mem_univ, exists_prop_of_true, Finset.mem_map]
exact ⟨0, And.intro True.intro rfl⟩
getLast_mem := by
simp only [boundaries, Finset.mem_univ, exists_prop_of_true, Finset.mem_map]
exact ⟨Fin.last c.length, And.intro True.intro c.boundary_last⟩
#align composition.to_composition_as_set Composition.toCompositionAsSet
theorem orderEmbOfFin_boundaries :
c.boundaries.orderEmbOfFin c.card_boundaries_eq_succ_length = c.boundary := by
refine (Finset.orderEmbOfFin_unique' _ ?_).symm
exact fun i => (Finset.mem_map' _).2 (Finset.mem_univ _)
#align composition.order_emb_of_fin_boundaries Composition.orderEmbOfFin_boundaries
def embedding (i : Fin c.length) : Fin (c.blocksFun i) ↪o Fin n :=
(Fin.natAddOrderEmb <| c.sizeUpTo i).trans <| Fin.castLEOrderEmb <|
calc
c.sizeUpTo i + c.blocksFun i = c.sizeUpTo (i + 1) := (c.sizeUpTo_succ _).symm
_ ≤ c.sizeUpTo c.length := monotone_sum_take _ i.2
_ = n := c.sizeUpTo_length
#align composition.embedding Composition.embedding
@[simp]
theorem coe_embedding (i : Fin c.length) (j : Fin (c.blocksFun i)) :
(c.embedding i j : ℕ) = c.sizeUpTo i + j :=
rfl
#align composition.coe_embedding Composition.coe_embedding
theorem index_exists {j : ℕ} (h : j < n) : ∃ i : ℕ, j < c.sizeUpTo (i + 1) ∧ i < c.length := by
have n_pos : 0 < n := lt_of_le_of_lt (zero_le j) h
have : 0 < c.blocks.sum := by rwa [← c.blocks_sum] at n_pos
have length_pos : 0 < c.blocks.length := length_pos_of_sum_pos (blocks c) this
refine ⟨c.length - 1, ?_, Nat.pred_lt (ne_of_gt length_pos)⟩
have : c.length - 1 + 1 = c.length := Nat.succ_pred_eq_of_pos length_pos
simp [this, h]
#align composition.index_exists Composition.index_exists
def index (j : Fin n) : Fin c.length :=
⟨Nat.find (c.index_exists j.2), (Nat.find_spec (c.index_exists j.2)).2⟩
#align composition.index Composition.index
theorem lt_sizeUpTo_index_succ (j : Fin n) : (j : ℕ) < c.sizeUpTo (c.index j).succ :=
(Nat.find_spec (c.index_exists j.2)).1
#align composition.lt_size_up_to_index_succ Composition.lt_sizeUpTo_index_succ
theorem sizeUpTo_index_le (j : Fin n) : c.sizeUpTo (c.index j) ≤ j := by
by_contra H
set i := c.index j
push_neg at H
have i_pos : (0 : ℕ) < i := by
by_contra! i_pos
revert H
simp [nonpos_iff_eq_zero.1 i_pos, c.sizeUpTo_zero]
let i₁ := (i : ℕ).pred
have i₁_lt_i : i₁ < i := Nat.pred_lt (ne_of_gt i_pos)
have i₁_succ : i₁ + 1 = i := Nat.succ_pred_eq_of_pos i_pos
have := Nat.find_min (c.index_exists j.2) i₁_lt_i
simp [lt_trans i₁_lt_i (c.index j).2, i₁_succ] at this
exact Nat.lt_le_asymm H this
#align composition.size_up_to_index_le Composition.sizeUpTo_index_le
def invEmbedding (j : Fin n) : Fin (c.blocksFun (c.index j)) :=
⟨j - c.sizeUpTo (c.index j), by
rw [tsub_lt_iff_right, add_comm, ← sizeUpTo_succ']
· exact lt_sizeUpTo_index_succ _ _
· exact sizeUpTo_index_le _ _⟩
#align composition.inv_embedding Composition.invEmbedding
@[simp]
theorem coe_invEmbedding (j : Fin n) : (c.invEmbedding j : ℕ) = j - c.sizeUpTo (c.index j) :=
rfl
#align composition.coe_inv_embedding Composition.coe_invEmbedding
theorem embedding_comp_inv (j : Fin n) : c.embedding (c.index j) (c.invEmbedding j) = j := by
rw [Fin.ext_iff]
apply add_tsub_cancel_of_le (c.sizeUpTo_index_le j)
#align composition.embedding_comp_inv Composition.embedding_comp_inv
theorem mem_range_embedding_iff {j : Fin n} {i : Fin c.length} :
j ∈ Set.range (c.embedding i) ↔ c.sizeUpTo i ≤ j ∧ (j : ℕ) < c.sizeUpTo (i : ℕ).succ := by
constructor
· intro h
rcases Set.mem_range.2 h with ⟨k, hk⟩
rw [Fin.ext_iff] at hk
dsimp at hk
rw [← hk]
simp [sizeUpTo_succ', k.is_lt]
· intro h
apply Set.mem_range.2
refine ⟨⟨j - c.sizeUpTo i, ?_⟩, ?_⟩
· rw [tsub_lt_iff_left, ← sizeUpTo_succ']
· exact h.2
· exact h.1
· rw [Fin.ext_iff]
exact add_tsub_cancel_of_le h.1
#align composition.mem_range_embedding_iff Composition.mem_range_embedding_iff
theorem disjoint_range {i₁ i₂ : Fin c.length} (h : i₁ ≠ i₂) :
Disjoint (Set.range (c.embedding i₁)) (Set.range (c.embedding i₂)) := by
classical
wlog h' : i₁ < i₂
· exact (this c h.symm (h.lt_or_lt.resolve_left h')).symm
by_contra d
obtain ⟨x, hx₁, hx₂⟩ :
∃ x : Fin n, x ∈ Set.range (c.embedding i₁) ∧ x ∈ Set.range (c.embedding i₂) :=
Set.not_disjoint_iff.1 d
have A : (i₁ : ℕ).succ ≤ i₂ := Nat.succ_le_of_lt h'
apply lt_irrefl (x : ℕ)
calc
(x : ℕ) < c.sizeUpTo (i₁ : ℕ).succ := (c.mem_range_embedding_iff.1 hx₁).2
_ ≤ c.sizeUpTo (i₂ : ℕ) := monotone_sum_take _ A
_ ≤ x := (c.mem_range_embedding_iff.1 hx₂).1
#align composition.disjoint_range Composition.disjoint_range
theorem mem_range_embedding (j : Fin n) : j ∈ Set.range (c.embedding (c.index j)) := by
have : c.embedding (c.index j) (c.invEmbedding j) ∈ Set.range (c.embedding (c.index j)) :=
Set.mem_range_self _
rwa [c.embedding_comp_inv j] at this
#align composition.mem_range_embedding Composition.mem_range_embedding
theorem mem_range_embedding_iff' {j : Fin n} {i : Fin c.length} :
j ∈ Set.range (c.embedding i) ↔ i = c.index j := by
constructor
· rw [← not_imp_not]
intro h
exact Set.disjoint_right.1 (c.disjoint_range h) (c.mem_range_embedding j)
· intro h
rw [h]
exact c.mem_range_embedding j
#align composition.mem_range_embedding_iff' Composition.mem_range_embedding_iff'
theorem index_embedding (i : Fin c.length) (j : Fin (c.blocksFun i)) :
c.index (c.embedding i j) = i := by
symm
rw [← mem_range_embedding_iff']
apply Set.mem_range_self
#align composition.index_embedding Composition.index_embedding
theorem invEmbedding_comp (i : Fin c.length) (j : Fin (c.blocksFun i)) :
(c.invEmbedding (c.embedding i j) : ℕ) = j := by
simp_rw [coe_invEmbedding, index_embedding, coe_embedding, add_tsub_cancel_left]
#align composition.inv_embedding_comp Composition.invEmbedding_comp
def blocksFinEquiv : (Σi : Fin c.length, Fin (c.blocksFun i)) ≃ Fin n where
toFun x := c.embedding x.1 x.2
invFun j := ⟨c.index j, c.invEmbedding j⟩
left_inv x := by
rcases x with ⟨i, y⟩
dsimp
congr; · exact c.index_embedding _ _
rw [Fin.heq_ext_iff]
· exact c.invEmbedding_comp _ _
· rw [c.index_embedding]
right_inv j := c.embedding_comp_inv j
#align composition.blocks_fin_equiv Composition.blocksFinEquiv
theorem blocksFun_congr {n₁ n₂ : ℕ} (c₁ : Composition n₁) (c₂ : Composition n₂) (i₁ : Fin c₁.length)
(i₂ : Fin c₂.length) (hn : n₁ = n₂) (hc : c₁.blocks = c₂.blocks) (hi : (i₁ : ℕ) = i₂) :
c₁.blocksFun i₁ = c₂.blocksFun i₂ := by
cases hn
rw [← Composition.ext_iff] at hc
cases hc
congr
rwa [Fin.ext_iff]
#align composition.blocks_fun_congr Composition.blocksFun_congr
theorem sigma_eq_iff_blocks_eq {c : Σn, Composition n} {c' : Σn, Composition n} :
c = c' ↔ c.2.blocks = c'.2.blocks := by
refine ⟨fun H => by rw [H], fun H => ?_⟩
rcases c with ⟨n, c⟩
rcases c' with ⟨n', c'⟩
have : n = n' := by rw [← c.blocks_sum, ← c'.blocks_sum, H]
induction this
congr
ext1
exact H
#align composition.sigma_eq_iff_blocks_eq Composition.sigma_eq_iff_blocks_eq
def ones (n : ℕ) : Composition n :=
⟨replicate n (1 : ℕ), fun {i} hi => by simp [List.eq_of_mem_replicate hi], by simp⟩
#align composition.ones Composition.ones
instance {n : ℕ} : Inhabited (Composition n) :=
⟨Composition.ones n⟩
@[simp]
theorem ones_length (n : ℕ) : (ones n).length = n :=
List.length_replicate n 1
#align composition.ones_length Composition.ones_length
@[simp]
theorem ones_blocks (n : ℕ) : (ones n).blocks = replicate n (1 : ℕ) :=
rfl
#align composition.ones_blocks Composition.ones_blocks
@[simp]
theorem ones_blocksFun (n : ℕ) (i : Fin (ones n).length) : (ones n).blocksFun i = 1 := by
simp only [blocksFun, ones, blocks, i.2, List.get_replicate]
#align composition.ones_blocks_fun Composition.ones_blocksFun
@[simp]
| Mathlib/Combinatorics/Enumerative/Composition.lean | 494 | 495 | theorem ones_sizeUpTo (n : ℕ) (i : ℕ) : (ones n).sizeUpTo i = min i n := by |
simp [sizeUpTo, ones_blocks, take_replicate]
|
import Mathlib.RingTheory.Derivation.Basic
import Mathlib.RingTheory.Ideal.QuotientOperations
#align_import ring_theory.derivation.to_square_zero from "leanprover-community/mathlib"@"b608348ffaeb7f557f2fd46876037abafd326ff3"
section ToSquareZero
universe u v w
variable {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [CommSemiring A] [CommRing B]
variable [Algebra R A] [Algebra R B] (I : Ideal B) (hI : I ^ 2 = ⊥)
def diffToIdealOfQuotientCompEq (f₁ f₂ : A →ₐ[R] B)
(e : (Ideal.Quotient.mkₐ R I).comp f₁ = (Ideal.Quotient.mkₐ R I).comp f₂) : A →ₗ[R] I :=
LinearMap.codRestrict (I.restrictScalars _) (f₁.toLinearMap - f₂.toLinearMap) (by
intro x
change f₁ x - f₂ x ∈ I
rw [← Ideal.Quotient.eq, ← Ideal.Quotient.mkₐ_eq_mk R, ← AlgHom.comp_apply, e]
rfl)
#align diff_to_ideal_of_quotient_comp_eq diffToIdealOfQuotientCompEq
@[simp]
theorem diffToIdealOfQuotientCompEq_apply (f₁ f₂ : A →ₐ[R] B)
(e : (Ideal.Quotient.mkₐ R I).comp f₁ = (Ideal.Quotient.mkₐ R I).comp f₂) (x : A) :
((diffToIdealOfQuotientCompEq I f₁ f₂ e) x : B) = f₁ x - f₂ x :=
rfl
#align diff_to_ideal_of_quotient_comp_eq_apply diffToIdealOfQuotientCompEq_apply
variable [Algebra A B] [IsScalarTower R A B]
def derivationToSquareZeroOfLift (f : A →ₐ[R] B)
(e : (Ideal.Quotient.mkₐ R I).comp f = IsScalarTower.toAlgHom R A (B ⧸ I)) :
Derivation R A I := by
refine
{ diffToIdealOfQuotientCompEq I f (IsScalarTower.toAlgHom R A B) ?_ with
map_one_eq_zero' := ?_
leibniz' := ?_ }
· rw [e]; ext; rfl
· ext; change f 1 - algebraMap A B 1 = 0; rw [map_one, map_one, sub_self]
· intro x y
let F := diffToIdealOfQuotientCompEq I f (IsScalarTower.toAlgHom R A B) (by rw [e]; ext; rfl)
have : (f x - algebraMap A B x) * (f y - algebraMap A B y) = 0 := by
rw [← Ideal.mem_bot, ← hI, pow_two]
convert Ideal.mul_mem_mul (F x).2 (F y).2 using 1
ext
dsimp only [Submodule.coe_add, Submodule.coe_mk, LinearMap.coe_mk,
diffToIdealOfQuotientCompEq_apply, Submodule.coe_smul_of_tower, IsScalarTower.coe_toAlgHom',
LinearMap.toFun_eq_coe]
simp only [map_mul, sub_mul, mul_sub, Algebra.smul_def] at this ⊢
rw [sub_eq_iff_eq_add, sub_eq_iff_eq_add] at this
simp only [LinearMap.coe_toAddHom, diffToIdealOfQuotientCompEq_apply, map_mul, this,
IsScalarTower.coe_toAlgHom']
ring
#align derivation_to_square_zero_of_lift derivationToSquareZeroOfLift
theorem derivationToSquareZeroOfLift_apply (f : A →ₐ[R] B)
(e : (Ideal.Quotient.mkₐ R I).comp f = IsScalarTower.toAlgHom R A (B ⧸ I)) (x : A) :
(derivationToSquareZeroOfLift I hI f e x : B) = f x - algebraMap A B x :=
rfl
#align derivation_to_square_zero_of_lift_apply derivationToSquareZeroOfLift_apply
@[simps (config := .lemmasOnly)]
def liftOfDerivationToSquareZero (f : Derivation R A I) : A →ₐ[R] B :=
{ ((I.restrictScalars R).subtype.comp f.toLinearMap + (IsScalarTower.toAlgHom R A B).toLinearMap :
A →ₗ[R] B) with
toFun := fun x => f x + algebraMap A B x
map_one' := by
dsimp
-- Note: added the `(algebraMap _ _)` hint because otherwise it would match `f 1`
rw [map_one (algebraMap _ _), f.map_one_eq_zero, Submodule.coe_zero, zero_add]
map_mul' := fun x y => by
have : (f x : B) * f y = 0 := by
rw [← Ideal.mem_bot, ← hI, pow_two]
convert Ideal.mul_mem_mul (f x).2 (f y).2 using 1
simp only [map_mul, f.leibniz, add_mul, mul_add, Submodule.coe_add,
Submodule.coe_smul_of_tower, Algebra.smul_def, this]
ring
commutes' := fun r => by
simp only [Derivation.map_algebraMap, eq_self_iff_true, zero_add, Submodule.coe_zero, ←
IsScalarTower.algebraMap_apply R A B r]
map_zero' := ((I.restrictScalars R).subtype.comp f.toLinearMap +
(IsScalarTower.toAlgHom R A B).toLinearMap).map_zero }
#align lift_of_derivation_to_square_zero liftOfDerivationToSquareZero
-- @[simp] -- Porting note: simp normal form is `liftOfDerivationToSquareZero_mk_apply'`
theorem liftOfDerivationToSquareZero_mk_apply (d : Derivation R A I) (x : A) :
Ideal.Quotient.mk I (liftOfDerivationToSquareZero I hI d x) = algebraMap A (B ⧸ I) x := by
rw [liftOfDerivationToSquareZero_apply, map_add, Ideal.Quotient.eq_zero_iff_mem.mpr (d x).prop,
zero_add]
rfl
#align lift_of_derivation_to_square_zero_mk_apply liftOfDerivationToSquareZero_mk_apply
@[simp]
| Mathlib/RingTheory/Derivation/ToSquareZero.lean | 114 | 116 | theorem liftOfDerivationToSquareZero_mk_apply' (d : Derivation R A I) (x : A) :
(Ideal.Quotient.mk I) (d x) + (algebraMap A (B ⧸ I)) x = algebraMap A (B ⧸ I) x := by |
simp only [Ideal.Quotient.eq_zero_iff_mem.mpr (d x).prop, zero_add]
|
import Mathlib.Order.ConditionallyCompleteLattice.Basic
import Mathlib.Order.RelIso.Basic
#align_import order.ord_continuous from "leanprover-community/mathlib"@"207cfac9fcd06138865b5d04f7091e46d9320432"
universe u v w x
variable {α : Type u} {β : Type v} {γ : Type w} {ι : Sort x}
open Function OrderDual Set
def LeftOrdContinuous [Preorder α] [Preorder β] (f : α → β) :=
∀ ⦃s : Set α⦄ ⦃x⦄, IsLUB s x → IsLUB (f '' s) (f x)
#align left_ord_continuous LeftOrdContinuous
def RightOrdContinuous [Preorder α] [Preorder β] (f : α → β) :=
∀ ⦃s : Set α⦄ ⦃x⦄, IsGLB s x → IsGLB (f '' s) (f x)
#align right_ord_continuous RightOrdContinuous
namespace LeftOrdContinuous
section ConditionallyCompleteLattice
variable [ConditionallyCompleteLattice α] [ConditionallyCompleteLattice β] [Nonempty ι] {f : α → β}
theorem map_csSup (hf : LeftOrdContinuous f) {s : Set α} (sne : s.Nonempty) (sbdd : BddAbove s) :
f (sSup s) = sSup (f '' s) :=
((hf <| isLUB_csSup sne sbdd).csSup_eq <| sne.image f).symm
#align left_ord_continuous.map_cSup LeftOrdContinuous.map_csSup
| Mathlib/Order/OrdContinuous.lean | 151 | 154 | theorem map_ciSup (hf : LeftOrdContinuous f) {g : ι → α} (hg : BddAbove (range g)) :
f (⨆ i, g i) = ⨆ i, f (g i) := by |
simp only [iSup, hf.map_csSup (range_nonempty _) hg, ← range_comp]
rfl
|
import Batteries.Data.Rat.Basic
import Batteries.Tactic.SeqFocus
namespace Rat
theorem ext : {p q : Rat} → p.num = q.num → p.den = q.den → p = q
| ⟨_,_,_,_⟩, ⟨_,_,_,_⟩, rfl, rfl => rfl
@[simp] theorem mk_den_one {r : Int} :
⟨r, 1, Nat.one_ne_zero, (Nat.coprime_one_right _)⟩ = (r : Rat) := rfl
@[simp] theorem zero_num : (0 : Rat).num = 0 := rfl
@[simp] theorem zero_den : (0 : Rat).den = 1 := rfl
@[simp] theorem one_num : (1 : Rat).num = 1 := rfl
@[simp] theorem one_den : (1 : Rat).den = 1 := rfl
@[simp] theorem maybeNormalize_eq {num den g} (den_nz reduced) :
maybeNormalize num den g den_nz reduced =
{ num := num.div g, den := den / g, den_nz, reduced } := by
unfold maybeNormalize; split
· subst g; simp
· rfl
theorem normalize.reduced' {num : Int} {den g : Nat} (den_nz : den ≠ 0)
(e : g = num.natAbs.gcd den) : (num / g).natAbs.Coprime (den / g) := by
rw [← Int.div_eq_ediv_of_dvd (e ▸ Int.ofNat_dvd_left.2 (Nat.gcd_dvd_left ..))]
exact normalize.reduced den_nz e
theorem normalize_eq {num den} (den_nz) : normalize num den den_nz =
{ num := num / num.natAbs.gcd den
den := den / num.natAbs.gcd den
den_nz := normalize.den_nz den_nz rfl
reduced := normalize.reduced' den_nz rfl } := by
simp only [normalize, maybeNormalize_eq,
Int.div_eq_ediv_of_dvd (Int.ofNat_dvd_left.2 (Nat.gcd_dvd_left ..))]
@[simp] theorem normalize_zero (nz) : normalize 0 d nz = 0 := by
simp [normalize, Int.zero_div, Int.natAbs_zero, Nat.div_self (Nat.pos_of_ne_zero nz)]; rfl
theorem mk_eq_normalize (num den nz c) : ⟨num, den, nz, c⟩ = normalize num den nz := by
simp [normalize_eq, c.gcd_eq_one]
theorem normalize_self (r : Rat) : normalize r.num r.den r.den_nz = r := (mk_eq_normalize ..).symm
theorem normalize_mul_left {a : Nat} (d0 : d ≠ 0) (a0 : a ≠ 0) :
normalize (↑a * n) (a * d) (Nat.mul_ne_zero a0 d0) = normalize n d d0 := by
simp [normalize_eq, mk'.injEq, Int.natAbs_mul, Nat.gcd_mul_left,
Nat.mul_div_mul_left _ _ (Nat.pos_of_ne_zero a0), Int.ofNat_mul,
Int.mul_ediv_mul_of_pos _ _ (Int.ofNat_pos.2 <| Nat.pos_of_ne_zero a0)]
theorem normalize_mul_right {a : Nat} (d0 : d ≠ 0) (a0 : a ≠ 0) :
normalize (n * a) (d * a) (Nat.mul_ne_zero d0 a0) = normalize n d d0 := by
rw [← normalize_mul_left (d0 := d0) a0]; congr 1 <;> [apply Int.mul_comm; apply Nat.mul_comm]
theorem normalize_eq_iff (z₁ : d₁ ≠ 0) (z₂ : d₂ ≠ 0) :
normalize n₁ d₁ z₁ = normalize n₂ d₂ z₂ ↔ n₁ * d₂ = n₂ * d₁ := by
constructor <;> intro h
· simp only [normalize_eq, mk'.injEq] at h
have' hn₁ := Int.ofNat_dvd_left.2 <| Nat.gcd_dvd_left n₁.natAbs d₁
have' hn₂ := Int.ofNat_dvd_left.2 <| Nat.gcd_dvd_left n₂.natAbs d₂
have' hd₁ := Int.ofNat_dvd.2 <| Nat.gcd_dvd_right n₁.natAbs d₁
have' hd₂ := Int.ofNat_dvd.2 <| Nat.gcd_dvd_right n₂.natAbs d₂
rw [← Int.ediv_mul_cancel (Int.dvd_trans hd₂ (Int.dvd_mul_left ..)),
Int.mul_ediv_assoc _ hd₂, ← Int.ofNat_ediv, ← h.2, Int.ofNat_ediv,
← Int.mul_ediv_assoc _ hd₁, Int.mul_ediv_assoc' _ hn₁,
Int.mul_right_comm, h.1, Int.ediv_mul_cancel hn₂]
· rw [← normalize_mul_right _ z₂, ← normalize_mul_left z₂ z₁, Int.mul_comm d₁, h]
theorem maybeNormalize_eq_normalize {num : Int} {den g : Nat} (den_nz reduced)
(hn : ↑g ∣ num) (hd : g ∣ den) :
maybeNormalize num den g den_nz reduced = normalize num den (mt (by simp [·]) den_nz) := by
simp only [maybeNormalize_eq, mk_eq_normalize, Int.div_eq_ediv_of_dvd hn]
have : g ≠ 0 := mt (by simp [·]) den_nz
rw [← normalize_mul_right _ this, Int.ediv_mul_cancel hn]
congr 1; exact Nat.div_mul_cancel hd
@[simp] theorem normalize_eq_zero (d0 : d ≠ 0) : normalize n d d0 = 0 ↔ n = 0 := by
have' := normalize_eq_iff d0 Nat.one_ne_zero
rw [normalize_zero (d := 1)] at this; rw [this]; simp
theorem normalize_num_den' (num den nz) : ∃ d : Nat, d ≠ 0 ∧
num = (normalize num den nz).num * d ∧ den = (normalize num den nz).den * d := by
refine ⟨num.natAbs.gcd den, Nat.gcd_ne_zero_right nz, ?_⟩
simp [normalize_eq, Int.ediv_mul_cancel (Int.ofNat_dvd_left.2 <| Nat.gcd_dvd_left ..),
Nat.div_mul_cancel (Nat.gcd_dvd_right ..)]
theorem normalize_num_den (h : normalize n d z = ⟨n', d', z', c⟩) :
∃ m : Nat, m ≠ 0 ∧ n = n' * m ∧ d = d' * m := by
have := normalize_num_den' n d z; rwa [h] at this
theorem normalize_eq_mkRat {num den} (den_nz) : normalize num den den_nz = mkRat num den := by
simp [mkRat, den_nz]
theorem mkRat_num_den (z : d ≠ 0) (h : mkRat n d = ⟨n', d', z', c⟩) :
∃ m : Nat, m ≠ 0 ∧ n = n' * m ∧ d = d' * m :=
normalize_num_den ((normalize_eq_mkRat z).symm ▸ h)
theorem mkRat_def (n d) : mkRat n d = if d0 : d = 0 then 0 else normalize n d d0 := rfl
theorem mkRat_self (a : Rat) : mkRat a.num a.den = a := by
rw [← normalize_eq_mkRat a.den_nz, normalize_self]
theorem mk_eq_mkRat (num den nz c) : ⟨num, den, nz, c⟩ = mkRat num den := by
simp [mk_eq_normalize, normalize_eq_mkRat]
@[simp] theorem zero_mkRat (n) : mkRat 0 n = 0 := by simp [mkRat_def]
@[simp] theorem mkRat_zero (n) : mkRat n 0 = 0 := by simp [mkRat_def]
theorem mkRat_eq_zero (d0 : d ≠ 0) : mkRat n d = 0 ↔ n = 0 := by simp [mkRat_def, d0]
theorem mkRat_ne_zero (d0 : d ≠ 0) : mkRat n d ≠ 0 ↔ n ≠ 0 := not_congr (mkRat_eq_zero d0)
theorem mkRat_mul_left {a : Nat} (a0 : a ≠ 0) : mkRat (↑a * n) (a * d) = mkRat n d := by
if d0 : d = 0 then simp [d0] else
rw [← normalize_eq_mkRat d0, ← normalize_mul_left d0 a0, normalize_eq_mkRat]
theorem mkRat_mul_right {a : Nat} (a0 : a ≠ 0) : mkRat (n * a) (d * a) = mkRat n d := by
rw [← mkRat_mul_left (d := d) a0]; congr 1 <;> [apply Int.mul_comm; apply Nat.mul_comm]
theorem mkRat_eq_iff (z₁ : d₁ ≠ 0) (z₂ : d₂ ≠ 0) :
mkRat n₁ d₁ = mkRat n₂ d₂ ↔ n₁ * d₂ = n₂ * d₁ := by
rw [← normalize_eq_mkRat z₁, ← normalize_eq_mkRat z₂, normalize_eq_iff]
@[simp] theorem divInt_ofNat (num den) : num /. (den : Nat) = mkRat num den := by
simp [divInt, normalize_eq_mkRat]
theorem mk_eq_divInt (num den nz c) : ⟨num, den, nz, c⟩ = num /. (den : Nat) := by
simp [mk_eq_mkRat]
theorem divInt_self (a : Rat) : a.num /. a.den = a := by rw [divInt_ofNat, mkRat_self]
@[simp] theorem zero_divInt (n) : 0 /. n = 0 := by cases n <;> simp [divInt]
@[simp] theorem divInt_zero (n) : n /. 0 = 0 := mkRat_zero n
theorem neg_divInt_neg (num den) : -num /. -den = num /. den := by
match den with
| Nat.succ n =>
simp only [divInt, Int.neg_ofNat_succ]
simp [normalize_eq_mkRat, Int.neg_neg]
| 0 => rfl
| Int.negSucc n =>
simp only [divInt, Int.neg_negSucc]
simp [normalize_eq_mkRat, Int.neg_neg]
theorem divInt_neg' (num den) : num /. -den = -num /. den := by rw [← neg_divInt_neg, Int.neg_neg]
theorem divInt_eq_iff (z₁ : d₁ ≠ 0) (z₂ : d₂ ≠ 0) :
n₁ /. d₁ = n₂ /. d₂ ↔ n₁ * d₂ = n₂ * d₁ := by
rcases Int.eq_nat_or_neg d₁ with ⟨_, rfl | rfl⟩ <;>
rcases Int.eq_nat_or_neg d₂ with ⟨_, rfl | rfl⟩ <;>
simp_all [divInt_neg', Int.ofNat_eq_zero, Int.neg_eq_zero,
mkRat_eq_iff, Int.neg_mul, Int.mul_neg, Int.eq_neg_comm, eq_comm]
theorem divInt_mul_left {a : Int} (a0 : a ≠ 0) : (a * n) /. (a * d) = n /. d := by
if d0 : d = 0 then simp [d0] else
simp [divInt_eq_iff (Int.mul_ne_zero a0 d0) d0, Int.mul_assoc, Int.mul_left_comm]
theorem divInt_mul_right {a : Int} (a0 : a ≠ 0) : (n * a) /. (d * a) = n /. d := by
simp [← divInt_mul_left (d := d) a0, Int.mul_comm]
| .lake/packages/batteries/Batteries/Data/Rat/Lemmas.lean | 170 | 178 | theorem divInt_num_den (z : d ≠ 0) (h : n /. d = ⟨n', d', z', c⟩) :
∃ m, m ≠ 0 ∧ n = n' * m ∧ d = d' * m := by |
rcases Int.eq_nat_or_neg d with ⟨_, rfl | rfl⟩ <;>
simp_all [divInt_neg', Int.ofNat_eq_zero, Int.neg_eq_zero]
· have ⟨m, h₁, h₂⟩ := mkRat_num_den z h; exists m
simp [Int.ofNat_eq_zero, Int.ofNat_mul, h₁, h₂]
· have ⟨m, h₁, h₂⟩ := mkRat_num_den z h; exists -m
rw [← Int.neg_inj, Int.neg_neg] at h₂
simp [Int.ofNat_eq_zero, Int.ofNat_mul, h₁, h₂, Int.mul_neg, Int.neg_eq_zero]
|
import Mathlib.Data.Fin.Basic
import Mathlib.Order.Chain
import Mathlib.Order.Cover
import Mathlib.Order.Fin
open Set
variable {α : Type*} [PartialOrder α] [BoundedOrder α] {n : ℕ} {f : Fin (n + 1) → α}
| Mathlib/Data/Fin/FlagRange.lean | 32 | 44 | theorem IsMaxChain.range_fin_of_covBy (h0 : f 0 = ⊥) (hlast : f (.last n) = ⊤)
(hcovBy : ∀ k : Fin n, f k.castSucc ⩿ f k.succ) :
IsMaxChain (· ≤ ·) (range f) := by |
have hmono : Monotone f := Fin.monotone_iff_le_succ.2 fun k ↦ (hcovBy k).1
refine ⟨hmono.isChain_range, fun t htc hbt ↦ hbt.antisymm fun x hx ↦ ?_⟩
rw [mem_range]; by_contra! h
suffices ∀ k, f k < x by simpa [hlast] using this (.last _)
intro k
induction k using Fin.induction with
| zero => simpa [h0, bot_lt_iff_ne_bot] using (h 0).symm
| succ k ihk =>
rw [range_subset_iff] at hbt
exact (htc.lt_of_le (hbt k.succ) hx (h _)).resolve_right ((hcovBy k).2 ihk)
|
import Mathlib.Analysis.InnerProductSpace.Basic
import Mathlib.Analysis.SpecialFunctions.Trigonometric.Inverse
#align_import geometry.euclidean.angle.unoriented.basic from "leanprover-community/mathlib"@"46b633fd842bef9469441c0209906f6dddd2b4f5"
assert_not_exists HasFDerivAt
assert_not_exists ConformalAt
noncomputable section
open Real Set
open Real
open RealInnerProductSpace
namespace InnerProductGeometry
variable {V : Type*} [NormedAddCommGroup V] [InnerProductSpace ℝ V] {x y : V}
def angle (x y : V) : ℝ :=
Real.arccos (⟪x, y⟫ / (‖x‖ * ‖y‖))
#align inner_product_geometry.angle InnerProductGeometry.angle
theorem continuousAt_angle {x : V × V} (hx1 : x.1 ≠ 0) (hx2 : x.2 ≠ 0) :
ContinuousAt (fun y : V × V => angle y.1 y.2) x :=
Real.continuous_arccos.continuousAt.comp <|
continuous_inner.continuousAt.div
((continuous_norm.comp continuous_fst).mul (continuous_norm.comp continuous_snd)).continuousAt
(by simp [hx1, hx2])
#align inner_product_geometry.continuous_at_angle InnerProductGeometry.continuousAt_angle
theorem angle_smul_smul {c : ℝ} (hc : c ≠ 0) (x y : V) : angle (c • x) (c • y) = angle x y := by
have : c * c ≠ 0 := mul_ne_zero hc hc
rw [angle, angle, real_inner_smul_left, inner_smul_right, norm_smul, norm_smul, Real.norm_eq_abs,
mul_mul_mul_comm _ ‖x‖, abs_mul_abs_self, ← mul_assoc c c, mul_div_mul_left _ _ this]
#align inner_product_geometry.angle_smul_smul InnerProductGeometry.angle_smul_smul
@[simp]
theorem _root_.LinearIsometry.angle_map {E F : Type*} [NormedAddCommGroup E] [NormedAddCommGroup F]
[InnerProductSpace ℝ E] [InnerProductSpace ℝ F] (f : E →ₗᵢ[ℝ] F) (u v : E) :
angle (f u) (f v) = angle u v := by
rw [angle, angle, f.inner_map_map, f.norm_map, f.norm_map]
#align linear_isometry.angle_map LinearIsometry.angle_map
@[simp, norm_cast]
theorem _root_.Submodule.angle_coe {s : Submodule ℝ V} (x y : s) :
angle (x : V) (y : V) = angle x y :=
s.subtypeₗᵢ.angle_map x y
#align submodule.angle_coe Submodule.angle_coe
theorem cos_angle (x y : V) : Real.cos (angle x y) = ⟪x, y⟫ / (‖x‖ * ‖y‖) :=
Real.cos_arccos (abs_le.mp (abs_real_inner_div_norm_mul_norm_le_one x y)).1
(abs_le.mp (abs_real_inner_div_norm_mul_norm_le_one x y)).2
#align inner_product_geometry.cos_angle InnerProductGeometry.cos_angle
theorem angle_comm (x y : V) : angle x y = angle y x := by
unfold angle
rw [real_inner_comm, mul_comm]
#align inner_product_geometry.angle_comm InnerProductGeometry.angle_comm
@[simp]
theorem angle_neg_neg (x y : V) : angle (-x) (-y) = angle x y := by
unfold angle
rw [inner_neg_neg, norm_neg, norm_neg]
#align inner_product_geometry.angle_neg_neg InnerProductGeometry.angle_neg_neg
theorem angle_nonneg (x y : V) : 0 ≤ angle x y :=
Real.arccos_nonneg _
#align inner_product_geometry.angle_nonneg InnerProductGeometry.angle_nonneg
theorem angle_le_pi (x y : V) : angle x y ≤ π :=
Real.arccos_le_pi _
#align inner_product_geometry.angle_le_pi InnerProductGeometry.angle_le_pi
theorem angle_neg_right (x y : V) : angle x (-y) = π - angle x y := by
unfold angle
rw [← Real.arccos_neg, norm_neg, inner_neg_right, neg_div]
#align inner_product_geometry.angle_neg_right InnerProductGeometry.angle_neg_right
theorem angle_neg_left (x y : V) : angle (-x) y = π - angle x y := by
rw [← angle_neg_neg, neg_neg, angle_neg_right]
#align inner_product_geometry.angle_neg_left InnerProductGeometry.angle_neg_left
proof_wanted angle_triangle (x y z : V) : angle x z ≤ angle x y + angle y z
@[simp]
theorem angle_zero_left (x : V) : angle 0 x = π / 2 := by
unfold angle
rw [inner_zero_left, zero_div, Real.arccos_zero]
#align inner_product_geometry.angle_zero_left InnerProductGeometry.angle_zero_left
@[simp]
theorem angle_zero_right (x : V) : angle x 0 = π / 2 := by
unfold angle
rw [inner_zero_right, zero_div, Real.arccos_zero]
#align inner_product_geometry.angle_zero_right InnerProductGeometry.angle_zero_right
@[simp]
theorem angle_self {x : V} (hx : x ≠ 0) : angle x x = 0 := by
unfold angle
rw [← real_inner_self_eq_norm_mul_norm, div_self (inner_self_ne_zero.2 hx : ⟪x, x⟫ ≠ 0),
Real.arccos_one]
#align inner_product_geometry.angle_self InnerProductGeometry.angle_self
@[simp]
theorem angle_self_neg_of_nonzero {x : V} (hx : x ≠ 0) : angle x (-x) = π := by
rw [angle_neg_right, angle_self hx, sub_zero]
#align inner_product_geometry.angle_self_neg_of_nonzero InnerProductGeometry.angle_self_neg_of_nonzero
@[simp]
theorem angle_neg_self_of_nonzero {x : V} (hx : x ≠ 0) : angle (-x) x = π := by
rw [angle_comm, angle_self_neg_of_nonzero hx]
#align inner_product_geometry.angle_neg_self_of_nonzero InnerProductGeometry.angle_neg_self_of_nonzero
@[simp]
theorem angle_smul_right_of_pos (x y : V) {r : ℝ} (hr : 0 < r) : angle x (r • y) = angle x y := by
unfold angle
rw [inner_smul_right, norm_smul, Real.norm_eq_abs, abs_of_nonneg (le_of_lt hr), ← mul_assoc,
mul_comm _ r, mul_assoc, mul_div_mul_left _ _ (ne_of_gt hr)]
#align inner_product_geometry.angle_smul_right_of_pos InnerProductGeometry.angle_smul_right_of_pos
@[simp]
theorem angle_smul_left_of_pos (x y : V) {r : ℝ} (hr : 0 < r) : angle (r • x) y = angle x y := by
rw [angle_comm, angle_smul_right_of_pos y x hr, angle_comm]
#align inner_product_geometry.angle_smul_left_of_pos InnerProductGeometry.angle_smul_left_of_pos
@[simp]
theorem angle_smul_right_of_neg (x y : V) {r : ℝ} (hr : r < 0) :
angle x (r • y) = angle x (-y) := by
rw [← neg_neg r, neg_smul, angle_neg_right, angle_smul_right_of_pos x y (neg_pos_of_neg hr),
angle_neg_right]
#align inner_product_geometry.angle_smul_right_of_neg InnerProductGeometry.angle_smul_right_of_neg
@[simp]
theorem angle_smul_left_of_neg (x y : V) {r : ℝ} (hr : r < 0) : angle (r • x) y = angle (-x) y := by
rw [angle_comm, angle_smul_right_of_neg y x hr, angle_comm]
#align inner_product_geometry.angle_smul_left_of_neg InnerProductGeometry.angle_smul_left_of_neg
theorem cos_angle_mul_norm_mul_norm (x y : V) : Real.cos (angle x y) * (‖x‖ * ‖y‖) = ⟪x, y⟫ := by
rw [cos_angle, div_mul_cancel_of_imp]
simp (config := { contextual := true }) [or_imp]
#align inner_product_geometry.cos_angle_mul_norm_mul_norm InnerProductGeometry.cos_angle_mul_norm_mul_norm
theorem sin_angle_mul_norm_mul_norm (x y : V) :
Real.sin (angle x y) * (‖x‖ * ‖y‖) = √(⟪x, x⟫ * ⟪y, y⟫ - ⟪x, y⟫ * ⟪x, y⟫) := by
unfold angle
rw [Real.sin_arccos, ← Real.sqrt_mul_self (mul_nonneg (norm_nonneg x) (norm_nonneg y)),
← Real.sqrt_mul' _ (mul_self_nonneg _), sq,
Real.sqrt_mul_self (mul_nonneg (norm_nonneg x) (norm_nonneg y)),
real_inner_self_eq_norm_mul_norm, real_inner_self_eq_norm_mul_norm]
by_cases h : ‖x‖ * ‖y‖ = 0
· rw [show ‖x‖ * ‖x‖ * (‖y‖ * ‖y‖) = ‖x‖ * ‖y‖ * (‖x‖ * ‖y‖) by ring, h, mul_zero,
mul_zero, zero_sub]
cases' eq_zero_or_eq_zero_of_mul_eq_zero h with hx hy
· rw [norm_eq_zero] at hx
rw [hx, inner_zero_left, zero_mul, neg_zero]
· rw [norm_eq_zero] at hy
rw [hy, inner_zero_right, zero_mul, neg_zero]
· field_simp [h]
ring_nf
#align inner_product_geometry.sin_angle_mul_norm_mul_norm InnerProductGeometry.sin_angle_mul_norm_mul_norm
theorem angle_eq_zero_iff {x y : V} : angle x y = 0 ↔ x ≠ 0 ∧ ∃ r : ℝ, 0 < r ∧ y = r • x := by
rw [angle, ← real_inner_div_norm_mul_norm_eq_one_iff, Real.arccos_eq_zero, LE.le.le_iff_eq,
eq_comm]
exact (abs_le.mp (abs_real_inner_div_norm_mul_norm_le_one x y)).2
#align inner_product_geometry.angle_eq_zero_iff InnerProductGeometry.angle_eq_zero_iff
theorem angle_eq_pi_iff {x y : V} : angle x y = π ↔ x ≠ 0 ∧ ∃ r : ℝ, r < 0 ∧ y = r • x := by
rw [angle, ← real_inner_div_norm_mul_norm_eq_neg_one_iff, Real.arccos_eq_pi, LE.le.le_iff_eq]
exact (abs_le.mp (abs_real_inner_div_norm_mul_norm_le_one x y)).1
#align inner_product_geometry.angle_eq_pi_iff InnerProductGeometry.angle_eq_pi_iff
theorem angle_add_angle_eq_pi_of_angle_eq_pi {x y : V} (z : V) (h : angle x y = π) :
angle x z + angle y z = π := by
rcases angle_eq_pi_iff.1 h with ⟨_, ⟨r, ⟨hr, rfl⟩⟩⟩
rw [angle_smul_left_of_neg x z hr, angle_neg_left, add_sub_cancel]
#align inner_product_geometry.angle_add_angle_eq_pi_of_angle_eq_pi InnerProductGeometry.angle_add_angle_eq_pi_of_angle_eq_pi
theorem inner_eq_zero_iff_angle_eq_pi_div_two (x y : V) : ⟪x, y⟫ = 0 ↔ angle x y = π / 2 :=
Iff.symm <| by simp (config := { contextual := true }) [angle, or_imp]
#align inner_product_geometry.inner_eq_zero_iff_angle_eq_pi_div_two InnerProductGeometry.inner_eq_zero_iff_angle_eq_pi_div_two
theorem inner_eq_neg_mul_norm_of_angle_eq_pi {x y : V} (h : angle x y = π) :
⟪x, y⟫ = -(‖x‖ * ‖y‖) := by
simp [← cos_angle_mul_norm_mul_norm, h]
#align inner_product_geometry.inner_eq_neg_mul_norm_of_angle_eq_pi InnerProductGeometry.inner_eq_neg_mul_norm_of_angle_eq_pi
theorem inner_eq_mul_norm_of_angle_eq_zero {x y : V} (h : angle x y = 0) : ⟪x, y⟫ = ‖x‖ * ‖y‖ := by
simp [← cos_angle_mul_norm_mul_norm, h]
#align inner_product_geometry.inner_eq_mul_norm_of_angle_eq_zero InnerProductGeometry.inner_eq_mul_norm_of_angle_eq_zero
theorem inner_eq_neg_mul_norm_iff_angle_eq_pi {x y : V} (hx : x ≠ 0) (hy : y ≠ 0) :
⟪x, y⟫ = -(‖x‖ * ‖y‖) ↔ angle x y = π := by
refine ⟨fun h => ?_, inner_eq_neg_mul_norm_of_angle_eq_pi⟩
have h₁ : ‖x‖ * ‖y‖ ≠ 0 := (mul_pos (norm_pos_iff.mpr hx) (norm_pos_iff.mpr hy)).ne'
rw [angle, h, neg_div, div_self h₁, Real.arccos_neg_one]
#align inner_product_geometry.inner_eq_neg_mul_norm_iff_angle_eq_pi InnerProductGeometry.inner_eq_neg_mul_norm_iff_angle_eq_pi
theorem inner_eq_mul_norm_iff_angle_eq_zero {x y : V} (hx : x ≠ 0) (hy : y ≠ 0) :
⟪x, y⟫ = ‖x‖ * ‖y‖ ↔ angle x y = 0 := by
refine ⟨fun h => ?_, inner_eq_mul_norm_of_angle_eq_zero⟩
have h₁ : ‖x‖ * ‖y‖ ≠ 0 := (mul_pos (norm_pos_iff.mpr hx) (norm_pos_iff.mpr hy)).ne'
rw [angle, h, div_self h₁, Real.arccos_one]
#align inner_product_geometry.inner_eq_mul_norm_iff_angle_eq_zero InnerProductGeometry.inner_eq_mul_norm_iff_angle_eq_zero
theorem norm_sub_eq_add_norm_of_angle_eq_pi {x y : V} (h : angle x y = π) :
‖x - y‖ = ‖x‖ + ‖y‖ := by
rw [← sq_eq_sq (norm_nonneg (x - y)) (add_nonneg (norm_nonneg x) (norm_nonneg y)),
norm_sub_pow_two_real, inner_eq_neg_mul_norm_of_angle_eq_pi h]
ring
#align inner_product_geometry.norm_sub_eq_add_norm_of_angle_eq_pi InnerProductGeometry.norm_sub_eq_add_norm_of_angle_eq_pi
| Mathlib/Geometry/Euclidean/Angle/Unoriented/Basic.lean | 279 | 283 | theorem norm_add_eq_add_norm_of_angle_eq_zero {x y : V} (h : angle x y = 0) :
‖x + y‖ = ‖x‖ + ‖y‖ := by |
rw [← sq_eq_sq (norm_nonneg (x + y)) (add_nonneg (norm_nonneg x) (norm_nonneg y)),
norm_add_pow_two_real, inner_eq_mul_norm_of_angle_eq_zero h]
ring
|
import Mathlib.Algebra.CharZero.Lemmas
import Mathlib.Order.Interval.Finset.Basic
#align_import data.int.interval from "leanprover-community/mathlib"@"1d29de43a5ba4662dd33b5cfeecfc2a27a5a8a29"
open Finset Int
namespace Int
instance instLocallyFiniteOrder : LocallyFiniteOrder ℤ where
finsetIcc a b :=
(Finset.range (b + 1 - a).toNat).map <| Nat.castEmbedding.trans <| addLeftEmbedding a
finsetIco a b := (Finset.range (b - a).toNat).map <| Nat.castEmbedding.trans <| addLeftEmbedding a
finsetIoc a b :=
(Finset.range (b - a).toNat).map <| Nat.castEmbedding.trans <| addLeftEmbedding (a + 1)
finsetIoo a b :=
(Finset.range (b - a - 1).toNat).map <| Nat.castEmbedding.trans <| addLeftEmbedding (a + 1)
finset_mem_Icc a b x := by
simp_rw [mem_map, mem_range, Int.lt_toNat, Function.Embedding.trans_apply,
Nat.castEmbedding_apply, addLeftEmbedding_apply]
constructor
· rintro ⟨a, h, rfl⟩
rw [lt_sub_iff_add_lt, Int.lt_add_one_iff, add_comm] at h
exact ⟨Int.le.intro a rfl, h⟩
· rintro ⟨ha, hb⟩
use (x - a).toNat
rw [← lt_add_one_iff] at hb
rw [toNat_sub_of_le ha]
exact ⟨sub_lt_sub_right hb _, add_sub_cancel _ _⟩
finset_mem_Ico a b x := by
simp_rw [mem_map, mem_range, Int.lt_toNat, Function.Embedding.trans_apply,
Nat.castEmbedding_apply, addLeftEmbedding_apply]
constructor
· rintro ⟨a, h, rfl⟩
exact ⟨Int.le.intro a rfl, lt_sub_iff_add_lt'.mp h⟩
· rintro ⟨ha, hb⟩
use (x - a).toNat
rw [toNat_sub_of_le ha]
exact ⟨sub_lt_sub_right hb _, add_sub_cancel _ _⟩
finset_mem_Ioc a b x := by
simp_rw [mem_map, mem_range, Int.lt_toNat, Function.Embedding.trans_apply,
Nat.castEmbedding_apply, addLeftEmbedding_apply]
constructor
· rintro ⟨a, h, rfl⟩
rw [← add_one_le_iff, le_sub_iff_add_le', add_comm _ (1 : ℤ), ← add_assoc] at h
exact ⟨Int.le.intro a rfl, h⟩
· rintro ⟨ha, hb⟩
use (x - (a + 1)).toNat
rw [toNat_sub_of_le ha, ← add_one_le_iff, sub_add, add_sub_cancel_right]
exact ⟨sub_le_sub_right hb _, add_sub_cancel _ _⟩
finset_mem_Ioo a b x := by
simp_rw [mem_map, mem_range, Int.lt_toNat, Function.Embedding.trans_apply,
Nat.castEmbedding_apply, addLeftEmbedding_apply]
constructor
· rintro ⟨a, h, rfl⟩
rw [sub_sub, lt_sub_iff_add_lt'] at h
exact ⟨Int.le.intro a rfl, h⟩
· rintro ⟨ha, hb⟩
use (x - (a + 1)).toNat
rw [toNat_sub_of_le ha, sub_sub]
exact ⟨sub_lt_sub_right hb _, add_sub_cancel _ _⟩
variable (a b : ℤ)
theorem Icc_eq_finset_map :
Icc a b =
(Finset.range (b + 1 - a).toNat).map (Nat.castEmbedding.trans <| addLeftEmbedding a) :=
rfl
#align int.Icc_eq_finset_map Int.Icc_eq_finset_map
theorem Ico_eq_finset_map :
Ico a b = (Finset.range (b - a).toNat).map (Nat.castEmbedding.trans <| addLeftEmbedding a) :=
rfl
#align int.Ico_eq_finset_map Int.Ico_eq_finset_map
theorem Ioc_eq_finset_map :
Ioc a b =
(Finset.range (b - a).toNat).map (Nat.castEmbedding.trans <| addLeftEmbedding (a + 1)) :=
rfl
#align int.Ioc_eq_finset_map Int.Ioc_eq_finset_map
theorem Ioo_eq_finset_map :
Ioo a b =
(Finset.range (b - a - 1).toNat).map (Nat.castEmbedding.trans <| addLeftEmbedding (a + 1)) :=
rfl
#align int.Ioo_eq_finset_map Int.Ioo_eq_finset_map
theorem uIcc_eq_finset_map :
uIcc a b = (range (max a b + 1 - min a b).toNat).map
(Nat.castEmbedding.trans <| addLeftEmbedding <| min a b) := rfl
#align int.uIcc_eq_finset_map Int.uIcc_eq_finset_map
@[simp]
theorem card_Icc : (Icc a b).card = (b + 1 - a).toNat := (card_map _).trans <| card_range _
#align int.card_Icc Int.card_Icc
@[simp]
theorem card_Ico : (Ico a b).card = (b - a).toNat := (card_map _).trans <| card_range _
#align int.card_Ico Int.card_Ico
@[simp]
theorem card_Ioc : (Ioc a b).card = (b - a).toNat := (card_map _).trans <| card_range _
#align int.card_Ioc Int.card_Ioc
@[simp]
theorem card_Ioo : (Ioo a b).card = (b - a - 1).toNat := (card_map _).trans <| card_range _
#align int.card_Ioo Int.card_Ioo
@[simp]
theorem card_uIcc : (uIcc a b).card = (b - a).natAbs + 1 :=
(card_map _).trans <|
Int.ofNat.inj <| by
-- Porting note (#11215): TODO: Restore `int.coe_nat_inj` and remove the `change`
change ((↑) : ℕ → ℤ) _ = ((↑) : ℕ → ℤ) _
rw [card_range, sup_eq_max, inf_eq_min,
Int.toNat_of_nonneg (sub_nonneg_of_le <| le_add_one min_le_max), Int.ofNat_add,
Int.natCast_natAbs, add_comm, add_sub_assoc, max_sub_min_eq_abs, add_comm, Int.ofNat_one]
#align int.card_uIcc Int.card_uIcc
| Mathlib/Data/Int/Interval.lean | 133 | 134 | theorem card_Icc_of_le (h : a ≤ b + 1) : ((Icc a b).card : ℤ) = b + 1 - a := by |
rw [card_Icc, toNat_sub_of_le h]
|
import Batteries.Data.RBMap.Alter
import Batteries.Data.List.Lemmas
namespace Batteries
namespace RBNode
open RBColor
attribute [simp] fold foldl foldr Any forM foldlM Ordered
@[simp] theorem min?_reverse (t : RBNode α) : t.reverse.min? = t.max? := by
unfold RBNode.max?; split <;> simp [RBNode.min?]
unfold RBNode.min?; rw [min?.match_1.eq_3]
· apply min?_reverse
· simpa [reverse_eq_iff]
@[simp] theorem max?_reverse (t : RBNode α) : t.reverse.max? = t.min? := by
rw [← min?_reverse, reverse_reverse]
@[simp] theorem mem_nil {x} : ¬x ∈ (.nil : RBNode α) := by simp [(·∈·), EMem]
@[simp] theorem mem_node {y c a x b} :
y ∈ (.node c a x b : RBNode α) ↔ y = x ∨ y ∈ a ∨ y ∈ b := by simp [(·∈·), EMem]
theorem All_def {t : RBNode α} : t.All p ↔ ∀ x ∈ t, p x := by
induction t <;> simp [or_imp, forall_and, *]
theorem Any_def {t : RBNode α} : t.Any p ↔ ∃ x ∈ t, p x := by
induction t <;> simp [or_and_right, exists_or, *]
theorem memP_def : MemP cut t ↔ ∃ x ∈ t, cut x = .eq := Any_def
theorem mem_def : Mem cmp x t ↔ ∃ y ∈ t, cmp x y = .eq := Any_def
| .lake/packages/batteries/Batteries/Data/RBMap/Lemmas.lean | 42 | 43 | theorem mem_congr [@TransCmp α cmp] {t : RBNode α} (h : cmp x y = .eq) :
Mem cmp x t ↔ Mem cmp y t := by | simp [Mem, TransCmp.cmp_congr_left' h]
|
import Mathlib.Algebra.Associated
import Mathlib.Algebra.BigOperators.Finsupp
#align_import algebra.big_operators.associated from "leanprover-community/mathlib"@"f7fc89d5d5ff1db2d1242c7bb0e9062ce47ef47c"
variable {α β γ δ : Type*}
-- the same local notation used in `Algebra.Associated`
local infixl:50 " ~ᵤ " => Associated
theorem Prod.associated_iff {M N : Type*} [Monoid M] [Monoid N] {x z : M × N} :
x ~ᵤ z ↔ x.1 ~ᵤ z.1 ∧ x.2 ~ᵤ z.2 :=
⟨fun ⟨u, hu⟩ => ⟨⟨(MulEquiv.prodUnits.toFun u).1, (Prod.eq_iff_fst_eq_snd_eq.1 hu).1⟩,
⟨(MulEquiv.prodUnits.toFun u).2, (Prod.eq_iff_fst_eq_snd_eq.1 hu).2⟩⟩,
fun ⟨⟨u₁, h₁⟩, ⟨u₂, h₂⟩⟩ =>
⟨MulEquiv.prodUnits.invFun (u₁, u₂), Prod.eq_iff_fst_eq_snd_eq.2 ⟨h₁, h₂⟩⟩⟩
theorem Associated.prod {M : Type*} [CommMonoid M] {ι : Type*} (s : Finset ι) (f : ι → M)
(g : ι → M) (h : ∀ i, i ∈ s → (f i) ~ᵤ (g i)) : (∏ i ∈ s, f i) ~ᵤ (∏ i ∈ s, g i) := by
induction s using Finset.induction with
| empty =>
simp only [Finset.prod_empty]
rfl
| @insert j s hjs IH =>
classical
convert_to (∏ i ∈ insert j s, f i) ~ᵤ (∏ i ∈ insert j s, g i)
rw [Finset.prod_insert hjs, Finset.prod_insert hjs]
exact Associated.mul_mul (h j (Finset.mem_insert_self j s))
(IH (fun i hi ↦ h i (Finset.mem_insert_of_mem hi)))
theorem exists_associated_mem_of_dvd_prod [CancelCommMonoidWithZero α] {p : α} (hp : Prime p)
{s : Multiset α} : (∀ r ∈ s, Prime r) → p ∣ s.prod → ∃ q ∈ s, p ~ᵤ q :=
Multiset.induction_on s (by simp [mt isUnit_iff_dvd_one.2 hp.not_unit]) fun a s ih hs hps => by
rw [Multiset.prod_cons] at hps
cases' hp.dvd_or_dvd hps with h h
· have hap := hs a (Multiset.mem_cons.2 (Or.inl rfl))
exact ⟨a, Multiset.mem_cons_self a _, hp.associated_of_dvd hap h⟩
· rcases ih (fun r hr => hs _ (Multiset.mem_cons.2 (Or.inr hr))) h with ⟨q, hq₁, hq₂⟩
exact ⟨q, Multiset.mem_cons.2 (Or.inr hq₁), hq₂⟩
#align exists_associated_mem_of_dvd_prod exists_associated_mem_of_dvd_prod
| Mathlib/Algebra/BigOperators/Associated.lean | 82 | 100 | theorem Multiset.prod_primes_dvd [CancelCommMonoidWithZero α]
[∀ a : α, DecidablePred (Associated a)] {s : Multiset α} (n : α) (h : ∀ a ∈ s, Prime a)
(div : ∀ a ∈ s, a ∣ n) (uniq : ∀ a, s.countP (Associated a) ≤ 1) : s.prod ∣ n := by |
induction' s using Multiset.induction_on with a s induct n primes divs generalizing n
· simp only [Multiset.prod_zero, one_dvd]
· rw [Multiset.prod_cons]
obtain ⟨k, rfl⟩ : a ∣ n := div a (Multiset.mem_cons_self a s)
apply mul_dvd_mul_left a
refine induct _ (fun a ha => h a (Multiset.mem_cons_of_mem ha)) (fun b b_in_s => ?_)
fun a => (Multiset.countP_le_of_le _ (Multiset.le_cons_self _ _)).trans (uniq a)
have b_div_n := div b (Multiset.mem_cons_of_mem b_in_s)
have a_prime := h a (Multiset.mem_cons_self a s)
have b_prime := h b (Multiset.mem_cons_of_mem b_in_s)
refine (b_prime.dvd_or_dvd b_div_n).resolve_left fun b_div_a => ?_
have assoc := b_prime.associated_of_dvd a_prime b_div_a
have := uniq a
rw [Multiset.countP_cons_of_pos _ (Associated.refl _), Nat.succ_le_succ_iff, ← not_lt,
Multiset.countP_pos] at this
exact this ⟨b, b_in_s, assoc.symm⟩
|
import Mathlib.Analysis.Calculus.ContDiff.Bounds
import Mathlib.Analysis.Calculus.IteratedDeriv.Defs
import Mathlib.Analysis.Calculus.LineDeriv.Basic
import Mathlib.Analysis.LocallyConvex.WithSeminorms
import Mathlib.Analysis.Normed.Group.ZeroAtInfty
import Mathlib.Analysis.SpecialFunctions.Pow.Real
import Mathlib.Analysis.SpecialFunctions.JapaneseBracket
import Mathlib.Topology.Algebra.UniformFilterBasis
import Mathlib.Tactic.MoveAdd
#align_import analysis.schwartz_space from "leanprover-community/mathlib"@"e137999b2c6f2be388f4cd3bbf8523de1910cd2b"
noncomputable section
open scoped Nat NNReal
variable {𝕜 𝕜' D E F G V : Type*}
variable [NormedAddCommGroup E] [NormedSpace ℝ E]
variable [NormedAddCommGroup F] [NormedSpace ℝ F]
variable (E F)
structure SchwartzMap where
toFun : E → F
smooth' : ContDiff ℝ ⊤ toFun
decay' : ∀ k n : ℕ, ∃ C : ℝ, ∀ x, ‖x‖ ^ k * ‖iteratedFDeriv ℝ n toFun x‖ ≤ C
#align schwartz_map SchwartzMap
scoped[SchwartzMap] notation "𝓢(" E ", " F ")" => SchwartzMap E F
variable {E F}
namespace SchwartzMap
-- Porting note: removed
-- instance : Coe 𝓢(E, F) (E → F) := ⟨toFun⟩
instance instFunLike : FunLike 𝓢(E, F) E F where
coe f := f.toFun
coe_injective' f g h := by cases f; cases g; congr
#align schwartz_map.fun_like SchwartzMap.instFunLike
instance instCoeFun : CoeFun 𝓢(E, F) fun _ => E → F :=
DFunLike.hasCoeToFun
#align schwartz_map.has_coe_to_fun SchwartzMap.instCoeFun
theorem decay (f : 𝓢(E, F)) (k n : ℕ) :
∃ C : ℝ, 0 < C ∧ ∀ x, ‖x‖ ^ k * ‖iteratedFDeriv ℝ n f x‖ ≤ C := by
rcases f.decay' k n with ⟨C, hC⟩
exact ⟨max C 1, by positivity, fun x => (hC x).trans (le_max_left _ _)⟩
#align schwartz_map.decay SchwartzMap.decay
theorem smooth (f : 𝓢(E, F)) (n : ℕ∞) : ContDiff ℝ n f :=
f.smooth'.of_le le_top
#align schwartz_map.smooth SchwartzMap.smooth
@[continuity]
protected theorem continuous (f : 𝓢(E, F)) : Continuous f :=
(f.smooth 0).continuous
#align schwartz_map.continuous SchwartzMap.continuous
instance instContinuousMapClass : ContinuousMapClass 𝓢(E, F) E F where
map_continuous := SchwartzMap.continuous
protected theorem differentiable (f : 𝓢(E, F)) : Differentiable ℝ f :=
(f.smooth 1).differentiable rfl.le
#align schwartz_map.differentiable SchwartzMap.differentiable
protected theorem differentiableAt (f : 𝓢(E, F)) {x : E} : DifferentiableAt ℝ f x :=
f.differentiable.differentiableAt
#align schwartz_map.differentiable_at SchwartzMap.differentiableAt
@[ext]
theorem ext {f g : 𝓢(E, F)} (h : ∀ x, (f : E → F) x = g x) : f = g :=
DFunLike.ext f g h
#align schwartz_map.ext SchwartzMap.ext
section IsBigO
open Asymptotics Filter
variable (f : 𝓢(E, F))
theorem isBigO_cocompact_zpow_neg_nat (k : ℕ) :
f =O[cocompact E] fun x => ‖x‖ ^ (-k : ℤ) := by
obtain ⟨d, _, hd'⟩ := f.decay k 0
simp only [norm_iteratedFDeriv_zero] at hd'
simp_rw [Asymptotics.IsBigO, Asymptotics.IsBigOWith]
refine ⟨d, Filter.Eventually.filter_mono Filter.cocompact_le_cofinite ?_⟩
refine (Filter.eventually_cofinite_ne 0).mono fun x hx => ?_
rw [Real.norm_of_nonneg (zpow_nonneg (norm_nonneg _) _), zpow_neg, ← div_eq_mul_inv, le_div_iff']
exacts [hd' x, zpow_pos_of_pos (norm_pos_iff.mpr hx) _]
set_option linter.uppercaseLean3 false in
#align schwartz_map.is_O_cocompact_zpow_neg_nat SchwartzMap.isBigO_cocompact_zpow_neg_nat
| Mathlib/Analysis/Distribution/SchwartzSpace.lean | 157 | 169 | theorem isBigO_cocompact_rpow [ProperSpace E] (s : ℝ) :
f =O[cocompact E] fun x => ‖x‖ ^ s := by |
let k := ⌈-s⌉₊
have hk : -(k : ℝ) ≤ s := neg_le.mp (Nat.le_ceil (-s))
refine (isBigO_cocompact_zpow_neg_nat f k).trans ?_
suffices (fun x : ℝ => x ^ (-k : ℤ)) =O[atTop] fun x : ℝ => x ^ s
from this.comp_tendsto tendsto_norm_cocompact_atTop
simp_rw [Asymptotics.IsBigO, Asymptotics.IsBigOWith]
refine ⟨1, (Filter.eventually_ge_atTop 1).mono fun x hx => ?_⟩
rw [one_mul, Real.norm_of_nonneg (Real.rpow_nonneg (zero_le_one.trans hx) _),
Real.norm_of_nonneg (zpow_nonneg (zero_le_one.trans hx) _), ← Real.rpow_intCast, Int.cast_neg,
Int.cast_natCast]
exact Real.rpow_le_rpow_of_exponent_le hx hk
|
import Mathlib.Tactic.Qify
import Mathlib.Data.ZMod.Basic
import Mathlib.NumberTheory.DiophantineApproximation
import Mathlib.NumberTheory.Zsqrtd.Basic
#align_import number_theory.pell from "leanprover-community/mathlib"@"7ad820c4997738e2f542f8a20f32911f52020e26"
namespace Pell
open Zsqrtd
theorem is_pell_solution_iff_mem_unitary {d : ℤ} {a : ℤ√d} :
a.re ^ 2 - d * a.im ^ 2 = 1 ↔ a ∈ unitary (ℤ√d) := by
rw [← norm_eq_one_iff_mem_unitary, norm_def, sq, sq, ← mul_assoc]
#align pell.is_pell_solution_iff_mem_unitary Pell.is_pell_solution_iff_mem_unitary
-- We use `solution₁ d` to allow for a more general structure `solution d m` that
-- encodes solutions to `x^2 - d*y^2 = m` to be added later.
def Solution₁ (d : ℤ) : Type :=
↥(unitary (ℤ√d))
#align pell.solution₁ Pell.Solution₁
namespace Solution₁
variable {d : ℤ}
-- Porting note(https://github.com/leanprover-community/mathlib4/issues/5020): manual deriving
instance instCommGroup : CommGroup (Solution₁ d) :=
inferInstanceAs (CommGroup (unitary (ℤ√d)))
#align pell.solution₁.comm_group Pell.Solution₁.instCommGroup
instance instHasDistribNeg : HasDistribNeg (Solution₁ d) :=
inferInstanceAs (HasDistribNeg (unitary (ℤ√d)))
#align pell.solution₁.has_distrib_neg Pell.Solution₁.instHasDistribNeg
instance instInhabited : Inhabited (Solution₁ d) :=
inferInstanceAs (Inhabited (unitary (ℤ√d)))
#align pell.solution₁.inhabited Pell.Solution₁.instInhabited
instance : Coe (Solution₁ d) (ℤ√d) where coe := Subtype.val
protected def x (a : Solution₁ d) : ℤ :=
(a : ℤ√d).re
#align pell.solution₁.x Pell.Solution₁.x
protected def y (a : Solution₁ d) : ℤ :=
(a : ℤ√d).im
#align pell.solution₁.y Pell.Solution₁.y
theorem prop (a : Solution₁ d) : a.x ^ 2 - d * a.y ^ 2 = 1 :=
is_pell_solution_iff_mem_unitary.mpr a.property
#align pell.solution₁.prop Pell.Solution₁.prop
theorem prop_x (a : Solution₁ d) : a.x ^ 2 = 1 + d * a.y ^ 2 := by rw [← a.prop]; ring
#align pell.solution₁.prop_x Pell.Solution₁.prop_x
theorem prop_y (a : Solution₁ d) : d * a.y ^ 2 = a.x ^ 2 - 1 := by rw [← a.prop]; ring
#align pell.solution₁.prop_y Pell.Solution₁.prop_y
@[ext]
theorem ext {a b : Solution₁ d} (hx : a.x = b.x) (hy : a.y = b.y) : a = b :=
Subtype.ext <| Zsqrtd.ext _ _ hx hy
#align pell.solution₁.ext Pell.Solution₁.ext
def mk (x y : ℤ) (prop : x ^ 2 - d * y ^ 2 = 1) : Solution₁ d where
val := ⟨x, y⟩
property := is_pell_solution_iff_mem_unitary.mp prop
#align pell.solution₁.mk Pell.Solution₁.mk
@[simp]
theorem x_mk (x y : ℤ) (prop : x ^ 2 - d * y ^ 2 = 1) : (mk x y prop).x = x :=
rfl
#align pell.solution₁.x_mk Pell.Solution₁.x_mk
@[simp]
theorem y_mk (x y : ℤ) (prop : x ^ 2 - d * y ^ 2 = 1) : (mk x y prop).y = y :=
rfl
#align pell.solution₁.y_mk Pell.Solution₁.y_mk
@[simp]
theorem coe_mk (x y : ℤ) (prop : x ^ 2 - d * y ^ 2 = 1) : (↑(mk x y prop) : ℤ√d) = ⟨x, y⟩ :=
Zsqrtd.ext _ _ (x_mk x y prop) (y_mk x y prop)
#align pell.solution₁.coe_mk Pell.Solution₁.coe_mk
@[simp]
theorem x_one : (1 : Solution₁ d).x = 1 :=
rfl
#align pell.solution₁.x_one Pell.Solution₁.x_one
@[simp]
theorem y_one : (1 : Solution₁ d).y = 0 :=
rfl
#align pell.solution₁.y_one Pell.Solution₁.y_one
@[simp]
theorem x_mul (a b : Solution₁ d) : (a * b).x = a.x * b.x + d * (a.y * b.y) := by
rw [← mul_assoc]
rfl
#align pell.solution₁.x_mul Pell.Solution₁.x_mul
@[simp]
theorem y_mul (a b : Solution₁ d) : (a * b).y = a.x * b.y + a.y * b.x :=
rfl
#align pell.solution₁.y_mul Pell.Solution₁.y_mul
@[simp]
theorem x_inv (a : Solution₁ d) : a⁻¹.x = a.x :=
rfl
#align pell.solution₁.x_inv Pell.Solution₁.x_inv
@[simp]
theorem y_inv (a : Solution₁ d) : a⁻¹.y = -a.y :=
rfl
#align pell.solution₁.y_inv Pell.Solution₁.y_inv
@[simp]
theorem x_neg (a : Solution₁ d) : (-a).x = -a.x :=
rfl
#align pell.solution₁.x_neg Pell.Solution₁.x_neg
@[simp]
theorem y_neg (a : Solution₁ d) : (-a).y = -a.y :=
rfl
#align pell.solution₁.y_neg Pell.Solution₁.y_neg
theorem eq_zero_of_d_neg (h₀ : d < 0) (a : Solution₁ d) : a.x = 0 ∨ a.y = 0 := by
have h := a.prop
contrapose! h
have h1 := sq_pos_of_ne_zero h.1
have h2 := sq_pos_of_ne_zero h.2
nlinarith
#align pell.solution₁.eq_zero_of_d_neg Pell.Solution₁.eq_zero_of_d_neg
theorem x_ne_zero (h₀ : 0 ≤ d) (a : Solution₁ d) : a.x ≠ 0 := by
intro hx
have h : 0 ≤ d * a.y ^ 2 := mul_nonneg h₀ (sq_nonneg _)
rw [a.prop_y, hx, sq, zero_mul, zero_sub] at h
exact not_le.mpr (neg_one_lt_zero : (-1 : ℤ) < 0) h
#align pell.solution₁.x_ne_zero Pell.Solution₁.x_ne_zero
theorem y_ne_zero_of_one_lt_x {a : Solution₁ d} (ha : 1 < a.x) : a.y ≠ 0 := by
intro hy
have prop := a.prop
rw [hy, sq (0 : ℤ), zero_mul, mul_zero, sub_zero] at prop
exact lt_irrefl _ (((one_lt_sq_iff <| zero_le_one.trans ha.le).mpr ha).trans_eq prop)
#align pell.solution₁.y_ne_zero_of_one_lt_x Pell.Solution₁.y_ne_zero_of_one_lt_x
theorem d_pos_of_one_lt_x {a : Solution₁ d} (ha : 1 < a.x) : 0 < d := by
refine pos_of_mul_pos_left ?_ (sq_nonneg a.y)
rw [a.prop_y, sub_pos]
exact one_lt_pow ha two_ne_zero
#align pell.solution₁.d_pos_of_one_lt_x Pell.Solution₁.d_pos_of_one_lt_x
theorem d_nonsquare_of_one_lt_x {a : Solution₁ d} (ha : 1 < a.x) : ¬IsSquare d := by
have hp := a.prop
rintro ⟨b, rfl⟩
simp_rw [← sq, ← mul_pow, sq_sub_sq, Int.mul_eq_one_iff_eq_one_or_neg_one] at hp
rcases hp with (⟨hp₁, hp₂⟩ | ⟨hp₁, hp₂⟩) <;> omega
#align pell.solution₁.d_nonsquare_of_one_lt_x Pell.Solution₁.d_nonsquare_of_one_lt_x
theorem eq_one_of_x_eq_one (h₀ : d ≠ 0) {a : Solution₁ d} (ha : a.x = 1) : a = 1 := by
have prop := a.prop_y
rw [ha, one_pow, sub_self, mul_eq_zero, or_iff_right h₀, sq_eq_zero_iff] at prop
exact ext ha prop
#align pell.solution₁.eq_one_of_x_eq_one Pell.Solution₁.eq_one_of_x_eq_one
| Mathlib/NumberTheory/Pell.lean | 256 | 260 | theorem eq_one_or_neg_one_iff_y_eq_zero {a : Solution₁ d} : a = 1 ∨ a = -1 ↔ a.y = 0 := by |
refine ⟨fun H => H.elim (fun h => by simp [h]) fun h => by simp [h], fun H => ?_⟩
have prop := a.prop
rw [H, sq (0 : ℤ), mul_zero, mul_zero, sub_zero, sq_eq_one_iff] at prop
exact prop.imp (fun h => ext h H) fun h => ext h H
|
import Mathlib.Topology.ContinuousOn
import Mathlib.Order.Minimal
open Set Classical
variable {X : Type*} {Y : Type*} [TopologicalSpace X] [TopologicalSpace Y] {s t : Set X}
section Preirreducible
def IsPreirreducible (s : Set X) : Prop :=
∀ u v : Set X, IsOpen u → IsOpen v → (s ∩ u).Nonempty → (s ∩ v).Nonempty → (s ∩ (u ∩ v)).Nonempty
#align is_preirreducible IsPreirreducible
def IsIrreducible (s : Set X) : Prop :=
s.Nonempty ∧ IsPreirreducible s
#align is_irreducible IsIrreducible
theorem IsIrreducible.nonempty (h : IsIrreducible s) : s.Nonempty :=
h.1
#align is_irreducible.nonempty IsIrreducible.nonempty
theorem IsIrreducible.isPreirreducible (h : IsIrreducible s) : IsPreirreducible s :=
h.2
#align is_irreducible.is_preirreducible IsIrreducible.isPreirreducible
theorem isPreirreducible_empty : IsPreirreducible (∅ : Set X) := fun _ _ _ _ _ ⟨_, h1, _⟩ =>
h1.elim
#align is_preirreducible_empty isPreirreducible_empty
theorem Set.Subsingleton.isPreirreducible (hs : s.Subsingleton) : IsPreirreducible s :=
fun _u _v _ _ ⟨_x, hxs, hxu⟩ ⟨y, hys, hyv⟩ => ⟨y, hys, hs hxs hys ▸ hxu, hyv⟩
#align set.subsingleton.is_preirreducible Set.Subsingleton.isPreirreducible
-- Porting note (#10756): new lemma
theorem isPreirreducible_singleton {x} : IsPreirreducible ({x} : Set X) :=
subsingleton_singleton.isPreirreducible
theorem isIrreducible_singleton {x} : IsIrreducible ({x} : Set X) :=
⟨singleton_nonempty x, isPreirreducible_singleton⟩
#align is_irreducible_singleton isIrreducible_singleton
theorem isPreirreducible_iff_closure : IsPreirreducible (closure s) ↔ IsPreirreducible s :=
forall₄_congr fun u v hu hv => by
iterate 3 rw [closure_inter_open_nonempty_iff]
exacts [hu.inter hv, hv, hu]
#align is_preirreducible_iff_closure isPreirreducible_iff_closure
theorem isIrreducible_iff_closure : IsIrreducible (closure s) ↔ IsIrreducible s :=
and_congr closure_nonempty_iff isPreirreducible_iff_closure
#align is_irreducible_iff_closure isIrreducible_iff_closure
protected alias ⟨_, IsPreirreducible.closure⟩ := isPreirreducible_iff_closure
#align is_preirreducible.closure IsPreirreducible.closure
protected alias ⟨_, IsIrreducible.closure⟩ := isIrreducible_iff_closure
#align is_irreducible.closure IsIrreducible.closure
theorem exists_preirreducible (s : Set X) (H : IsPreirreducible s) :
∃ t : Set X, IsPreirreducible t ∧ s ⊆ t ∧ ∀ u, IsPreirreducible u → t ⊆ u → u = t :=
let ⟨m, hm, hsm, hmm⟩ :=
zorn_subset_nonempty { t : Set X | IsPreirreducible t }
(fun c hc hcc _ =>
⟨⋃₀ c, fun u v hu hv ⟨y, hy, hyu⟩ ⟨x, hx, hxv⟩ =>
let ⟨p, hpc, hyp⟩ := mem_sUnion.1 hy
let ⟨q, hqc, hxq⟩ := mem_sUnion.1 hx
Or.casesOn (hcc.total hpc hqc)
(fun hpq : p ⊆ q =>
let ⟨x, hxp, hxuv⟩ := hc hqc u v hu hv ⟨y, hpq hyp, hyu⟩ ⟨x, hxq, hxv⟩
⟨x, mem_sUnion_of_mem hxp hqc, hxuv⟩)
fun hqp : q ⊆ p =>
let ⟨x, hxp, hxuv⟩ := hc hpc u v hu hv ⟨y, hyp, hyu⟩ ⟨x, hqp hxq, hxv⟩
⟨x, mem_sUnion_of_mem hxp hpc, hxuv⟩,
fun _ hxc => subset_sUnion_of_mem hxc⟩)
s H
⟨m, hm, hsm, fun _u hu hmu => hmm _ hu hmu⟩
#align exists_preirreducible exists_preirreducible
def irreducibleComponents (X : Type*) [TopologicalSpace X] : Set (Set X) :=
maximals (· ≤ ·) { s : Set X | IsIrreducible s }
#align irreducible_components irreducibleComponents
theorem isClosed_of_mem_irreducibleComponents (s) (H : s ∈ irreducibleComponents X) :
IsClosed s := by
rw [← closure_eq_iff_isClosed, eq_comm]
exact subset_closure.antisymm (H.2 H.1.closure subset_closure)
#align is_closed_of_mem_irreducible_components isClosed_of_mem_irreducibleComponents
theorem irreducibleComponents_eq_maximals_closed (X : Type*) [TopologicalSpace X] :
irreducibleComponents X = maximals (· ≤ ·) { s : Set X | IsClosed s ∧ IsIrreducible s } := by
ext s
constructor
· intro H
exact ⟨⟨isClosed_of_mem_irreducibleComponents _ H, H.1⟩, fun x h e => H.2 h.2 e⟩
· intro H
refine ⟨H.1.2, fun x h e => ?_⟩
have : closure x ≤ s := H.2 ⟨isClosed_closure, h.closure⟩ (e.trans subset_closure)
exact le_trans subset_closure this
#align irreducible_components_eq_maximals_closed irreducibleComponents_eq_maximals_closed
def irreducibleComponent (x : X) : Set X :=
Classical.choose (exists_preirreducible {x} isPreirreducible_singleton)
#align irreducible_component irreducibleComponent
theorem irreducibleComponent_property (x : X) :
IsPreirreducible (irreducibleComponent x) ∧
{x} ⊆ irreducibleComponent x ∧
∀ u, IsPreirreducible u → irreducibleComponent x ⊆ u → u = irreducibleComponent x :=
Classical.choose_spec (exists_preirreducible {x} isPreirreducible_singleton)
#align irreducible_component_property irreducibleComponent_property
theorem mem_irreducibleComponent {x : X} : x ∈ irreducibleComponent x :=
singleton_subset_iff.1 (irreducibleComponent_property x).2.1
#align mem_irreducible_component mem_irreducibleComponent
theorem isIrreducible_irreducibleComponent {x : X} : IsIrreducible (irreducibleComponent x) :=
⟨⟨x, mem_irreducibleComponent⟩, (irreducibleComponent_property x).1⟩
#align is_irreducible_irreducible_component isIrreducible_irreducibleComponent
theorem eq_irreducibleComponent {x : X} :
IsPreirreducible s → irreducibleComponent x ⊆ s → s = irreducibleComponent x :=
(irreducibleComponent_property x).2.2 _
#align eq_irreducible_component eq_irreducibleComponent
theorem irreducibleComponent_mem_irreducibleComponents (x : X) :
irreducibleComponent x ∈ irreducibleComponents X :=
⟨isIrreducible_irreducibleComponent, fun _ h₁ h₂ => (eq_irreducibleComponent h₁.2 h₂).le⟩
#align irreducible_component_mem_irreducible_components irreducibleComponent_mem_irreducibleComponents
theorem isClosed_irreducibleComponent {x : X} : IsClosed (irreducibleComponent x) :=
isClosed_of_mem_irreducibleComponents _ (irreducibleComponent_mem_irreducibleComponents x)
#align is_closed_irreducible_component isClosed_irreducibleComponent
class PreirreducibleSpace (X : Type*) [TopologicalSpace X] : Prop where
isPreirreducible_univ : IsPreirreducible (univ : Set X)
#align preirreducible_space PreirreducibleSpace
class IrreducibleSpace (X : Type*) [TopologicalSpace X] extends PreirreducibleSpace X : Prop where
toNonempty : Nonempty X
#align irreducible_space IrreducibleSpace
-- see Note [lower instance priority]
attribute [instance 50] IrreducibleSpace.toNonempty
theorem IrreducibleSpace.isIrreducible_univ (X : Type*) [TopologicalSpace X] [IrreducibleSpace X] :
IsIrreducible (univ : Set X) :=
⟨univ_nonempty, PreirreducibleSpace.isPreirreducible_univ⟩
#align irreducible_space.is_irreducible_univ IrreducibleSpace.isIrreducible_univ
theorem irreducibleSpace_def (X : Type*) [TopologicalSpace X] :
IrreducibleSpace X ↔ IsIrreducible (⊤ : Set X) :=
⟨@IrreducibleSpace.isIrreducible_univ X _, fun h =>
haveI : PreirreducibleSpace X := ⟨h.2⟩
⟨⟨h.1.some⟩⟩⟩
#align irreducible_space_def irreducibleSpace_def
theorem nonempty_preirreducible_inter [PreirreducibleSpace X] :
IsOpen s → IsOpen t → s.Nonempty → t.Nonempty → (s ∩ t).Nonempty := by
simpa only [univ_inter, univ_subset_iff] using
@PreirreducibleSpace.isPreirreducible_univ X _ _ s t
#align nonempty_preirreducible_inter nonempty_preirreducible_inter
protected theorem IsOpen.dense [PreirreducibleSpace X] (ho : IsOpen s) (hne : s.Nonempty) :
Dense s :=
dense_iff_inter_open.2 fun _t hto htne => nonempty_preirreducible_inter hto ho htne hne
#align is_open.dense IsOpen.dense
theorem IsPreirreducible.image (H : IsPreirreducible s) (f : X → Y) (hf : ContinuousOn f s) :
IsPreirreducible (f '' s) := by
rintro u v hu hv ⟨_, ⟨⟨x, hx, rfl⟩, hxu⟩⟩ ⟨_, ⟨⟨y, hy, rfl⟩, hyv⟩⟩
rw [← mem_preimage] at hxu hyv
rcases continuousOn_iff'.1 hf u hu with ⟨u', hu', u'_eq⟩
rcases continuousOn_iff'.1 hf v hv with ⟨v', hv', v'_eq⟩
have := H u' v' hu' hv'
rw [inter_comm s u', ← u'_eq] at this
rw [inter_comm s v', ← v'_eq] at this
rcases this ⟨x, hxu, hx⟩ ⟨y, hyv, hy⟩ with ⟨x, hxs, hxu', hxv'⟩
refine ⟨f x, mem_image_of_mem f hxs, ?_, ?_⟩
all_goals
rw [← mem_preimage]
apply mem_of_mem_inter_left
show x ∈ _ ∩ s
simp [*]
#align is_preirreducible.image IsPreirreducible.image
theorem IsIrreducible.image (H : IsIrreducible s) (f : X → Y) (hf : ContinuousOn f s) :
IsIrreducible (f '' s) :=
⟨H.nonempty.image _, H.isPreirreducible.image f hf⟩
#align is_irreducible.image IsIrreducible.image
theorem Subtype.preirreducibleSpace (h : IsPreirreducible s) : PreirreducibleSpace s where
isPreirreducible_univ := by
rintro _ _ ⟨u, hu, rfl⟩ ⟨v, hv, rfl⟩ ⟨⟨x, hxs⟩, -, hxu⟩ ⟨⟨y, hys⟩, -, hyv⟩
rcases h u v hu hv ⟨x, hxs, hxu⟩ ⟨y, hys, hyv⟩ with ⟨x, hxs, ⟨hxu, hxv⟩⟩
exact ⟨⟨x, hxs⟩, ⟨Set.mem_univ _, ⟨hxu, hxv⟩⟩⟩
#align subtype.preirreducible_space Subtype.preirreducibleSpace
theorem Subtype.irreducibleSpace (h : IsIrreducible s) : IrreducibleSpace s where
isPreirreducible_univ :=
(Subtype.preirreducibleSpace h.isPreirreducible).isPreirreducible_univ
toNonempty := h.nonempty.to_subtype
#align subtype.irreducible_space Subtype.irreducibleSpace
instance (priority := 100) {X} [Infinite X] : IrreducibleSpace (CofiniteTopology X) where
isPreirreducible_univ u v := by
haveI : Infinite (CofiniteTopology X) := ‹_›
simp only [CofiniteTopology.isOpen_iff, univ_inter]
intro hu hv hu' hv'
simpa only [compl_union, compl_compl] using ((hu hu').union (hv hv')).infinite_compl.nonempty
toNonempty := (inferInstance : Nonempty X)
| Mathlib/Topology/Irreducible.lean | 252 | 265 | theorem isIrreducible_iff_sInter :
IsIrreducible s ↔
∀ (U : Finset (Set X)), (∀ u ∈ U, IsOpen u) → (∀ u ∈ U, (s ∩ u).Nonempty) →
(s ∩ ⋂₀ ↑U).Nonempty := by |
refine ⟨fun h U hu hU => ?_, fun h => ⟨?_, ?_⟩⟩
· induction U using Finset.induction_on with
| empty => simpa using h.nonempty
| @insert u U _ IH =>
rw [Finset.coe_insert, sInter_insert]
rw [Finset.forall_mem_insert] at hu hU
exact h.2 _ _ hu.1 (U.finite_toSet.isOpen_sInter hu.2) hU.1 (IH hu.2 hU.2)
· simpa using h ∅
· intro u v hu hv hu' hv'
simpa [*] using h {u, v}
|
import Mathlib.Data.Nat.Choose.Dvd
import Mathlib.RingTheory.IntegrallyClosed
import Mathlib.RingTheory.Norm
import Mathlib.RingTheory.Polynomial.Cyclotomic.Expand
#align_import ring_theory.polynomial.eisenstein.is_integral from "leanprover-community/mathlib"@"5bfbcca0a7ffdd21cf1682e59106d6c942434a32"
universe u v w z
variable {R : Type u}
open Ideal Algebra Finset
open scoped Polynomial
section Cyclotomic
variable (p : ℕ)
local notation "𝓟" => Submodule.span ℤ {(p : ℤ)}
open Polynomial
| Mathlib/RingTheory/Polynomial/Eisenstein/IsIntegral.lean | 44 | 73 | theorem cyclotomic_comp_X_add_one_isEisensteinAt [hp : Fact p.Prime] :
((cyclotomic p ℤ).comp (X + 1)).IsEisensteinAt 𝓟 := by |
refine Monic.isEisensteinAt_of_mem_of_not_mem ?_
(Ideal.IsPrime.ne_top <| (Ideal.span_singleton_prime (mod_cast hp.out.ne_zero)).2 <|
Nat.prime_iff_prime_int.1 hp.out) (fun {i hi} => ?_) ?_
· rw [show (X + 1 : ℤ[X]) = X + C 1 by simp]
refine (cyclotomic.monic p ℤ).comp (monic_X_add_C 1) fun h => ?_
rw [natDegree_X_add_C] at h
exact zero_ne_one h.symm
· rw [cyclotomic_prime, geom_sum_X_comp_X_add_one_eq_sum, ← lcoeff_apply, map_sum]
conv =>
congr
congr
next => skip
ext
rw [lcoeff_apply, ← C_eq_natCast, C_mul_X_pow_eq_monomial, coeff_monomial]
rw [natDegree_comp, show (X + 1 : ℤ[X]) = X + C 1 by simp, natDegree_X_add_C, mul_one,
natDegree_cyclotomic, Nat.totient_prime hp.out] at hi
simp only [hi.trans_le (Nat.sub_le _ _), sum_ite_eq', mem_range, if_true,
Ideal.submodule_span_eq, Ideal.mem_span_singleton, Int.natCast_dvd_natCast]
exact hp.out.dvd_choose_self i.succ_ne_zero (lt_tsub_iff_right.1 hi)
· rw [coeff_zero_eq_eval_zero, eval_comp, cyclotomic_prime, eval_add, eval_X, eval_one, zero_add,
eval_geom_sum, one_geom_sum, Ideal.submodule_span_eq, Ideal.span_singleton_pow,
Ideal.mem_span_singleton]
intro h
obtain ⟨k, hk⟩ := Int.natCast_dvd_natCast.1 h
rw [mul_assoc, mul_comm 1, mul_one] at hk
nth_rw 1 [← Nat.mul_one p] at hk
rw [mul_right_inj' hp.out.ne_zero] at hk
exact Nat.Prime.not_dvd_one hp.out (Dvd.intro k hk.symm)
|
import Mathlib.Analysis.SpecialFunctions.Complex.Log
#align_import analysis.special_functions.pow.complex from "leanprover-community/mathlib"@"4fa54b337f7d52805480306db1b1439c741848c8"
open scoped Classical
open Real Topology Filter ComplexConjugate Finset Set
namespace Complex
noncomputable def cpow (x y : ℂ) : ℂ :=
if x = 0 then if y = 0 then 1 else 0 else exp (log x * y)
#align complex.cpow Complex.cpow
noncomputable instance : Pow ℂ ℂ :=
⟨cpow⟩
@[simp]
theorem cpow_eq_pow (x y : ℂ) : cpow x y = x ^ y :=
rfl
#align complex.cpow_eq_pow Complex.cpow_eq_pow
theorem cpow_def (x y : ℂ) : x ^ y = if x = 0 then if y = 0 then 1 else 0 else exp (log x * y) :=
rfl
#align complex.cpow_def Complex.cpow_def
theorem cpow_def_of_ne_zero {x : ℂ} (hx : x ≠ 0) (y : ℂ) : x ^ y = exp (log x * y) :=
if_neg hx
#align complex.cpow_def_of_ne_zero Complex.cpow_def_of_ne_zero
@[simp]
theorem cpow_zero (x : ℂ) : x ^ (0 : ℂ) = 1 := by simp [cpow_def]
#align complex.cpow_zero Complex.cpow_zero
@[simp]
theorem cpow_eq_zero_iff (x y : ℂ) : x ^ y = 0 ↔ x = 0 ∧ y ≠ 0 := by
simp only [cpow_def]
split_ifs <;> simp [*, exp_ne_zero]
#align complex.cpow_eq_zero_iff Complex.cpow_eq_zero_iff
@[simp]
theorem zero_cpow {x : ℂ} (h : x ≠ 0) : (0 : ℂ) ^ x = 0 := by simp [cpow_def, *]
#align complex.zero_cpow Complex.zero_cpow
theorem zero_cpow_eq_iff {x : ℂ} {a : ℂ} : (0 : ℂ) ^ x = a ↔ x ≠ 0 ∧ a = 0 ∨ x = 0 ∧ a = 1 := by
constructor
· intro hyp
simp only [cpow_def, eq_self_iff_true, if_true] at hyp
by_cases h : x = 0
· subst h
simp only [if_true, eq_self_iff_true] at hyp
right
exact ⟨rfl, hyp.symm⟩
· rw [if_neg h] at hyp
left
exact ⟨h, hyp.symm⟩
· rintro (⟨h, rfl⟩ | ⟨rfl, rfl⟩)
· exact zero_cpow h
· exact cpow_zero _
#align complex.zero_cpow_eq_iff Complex.zero_cpow_eq_iff
theorem eq_zero_cpow_iff {x : ℂ} {a : ℂ} : a = (0 : ℂ) ^ x ↔ x ≠ 0 ∧ a = 0 ∨ x = 0 ∧ a = 1 := by
rw [← zero_cpow_eq_iff, eq_comm]
#align complex.eq_zero_cpow_iff Complex.eq_zero_cpow_iff
@[simp]
theorem cpow_one (x : ℂ) : x ^ (1 : ℂ) = x :=
if hx : x = 0 then by simp [hx, cpow_def]
else by rw [cpow_def, if_neg (one_ne_zero : (1 : ℂ) ≠ 0), if_neg hx, mul_one, exp_log hx]
#align complex.cpow_one Complex.cpow_one
@[simp]
theorem one_cpow (x : ℂ) : (1 : ℂ) ^ x = 1 := by
rw [cpow_def]
split_ifs <;> simp_all [one_ne_zero]
#align complex.one_cpow Complex.one_cpow
theorem cpow_add {x : ℂ} (y z : ℂ) (hx : x ≠ 0) : x ^ (y + z) = x ^ y * x ^ z := by
simp only [cpow_def, ite_mul, boole_mul, mul_ite, mul_boole]
simp_all [exp_add, mul_add]
#align complex.cpow_add Complex.cpow_add
| Mathlib/Analysis/SpecialFunctions/Pow/Complex.lean | 96 | 99 | theorem cpow_mul {x y : ℂ} (z : ℂ) (h₁ : -π < (log x * y).im) (h₂ : (log x * y).im ≤ π) :
x ^ (y * z) = (x ^ y) ^ z := by |
simp only [cpow_def]
split_ifs <;> simp_all [exp_ne_zero, log_exp h₁ h₂, mul_assoc]
|
import Mathlib.Analysis.SpecialFunctions.Gaussian.GaussianIntegral
import Mathlib.Analysis.Complex.CauchyIntegral
import Mathlib.MeasureTheory.Integral.Pi
import Mathlib.Analysis.Fourier.FourierTransform
open Real Set MeasureTheory Filter Asymptotics intervalIntegral
open scoped Real Topology FourierTransform RealInnerProductSpace
open Complex hiding exp continuous_exp abs_of_nonneg sq_abs
noncomputable section
namespace GaussianFourier
variable {b : ℂ}
def verticalIntegral (b : ℂ) (c T : ℝ) : ℂ :=
∫ y : ℝ in (0 : ℝ)..c, I * (cexp (-b * (T + y * I) ^ 2) - cexp (-b * (T - y * I) ^ 2))
#align gaussian_fourier.vertical_integral GaussianFourier.verticalIntegral
theorem norm_cexp_neg_mul_sq_add_mul_I (b : ℂ) (c T : ℝ) :
‖cexp (-b * (T + c * I) ^ 2)‖ = exp (-(b.re * T ^ 2 - 2 * b.im * c * T - b.re * c ^ 2)) := by
rw [Complex.norm_eq_abs, Complex.abs_exp, neg_mul, neg_re, ← re_add_im b]
simp only [sq, re_add_im, mul_re, mul_im, add_re, add_im, ofReal_re, ofReal_im, I_re, I_im]
ring_nf
set_option linter.uppercaseLean3 false in
#align gaussian_fourier.norm_cexp_neg_mul_sq_add_mul_I GaussianFourier.norm_cexp_neg_mul_sq_add_mul_I
| Mathlib/Analysis/SpecialFunctions/Gaussian/FourierTransform.lean | 59 | 66 | theorem norm_cexp_neg_mul_sq_add_mul_I' (hb : b.re ≠ 0) (c T : ℝ) :
‖cexp (-b * (T + c * I) ^ 2)‖ =
exp (-(b.re * (T - b.im * c / b.re) ^ 2 - c ^ 2 * (b.im ^ 2 / b.re + b.re))) := by |
have :
b.re * T ^ 2 - 2 * b.im * c * T - b.re * c ^ 2 =
b.re * (T - b.im * c / b.re) ^ 2 - c ^ 2 * (b.im ^ 2 / b.re + b.re) := by
field_simp; ring
rw [norm_cexp_neg_mul_sq_add_mul_I, this]
|
import Mathlib.NumberTheory.LegendreSymbol.QuadraticChar.Basic
#align_import number_theory.legendre_symbol.basic from "leanprover-community/mathlib"@"5b2fe80501ff327b9109fb09b7cc8c325cd0d7d9"
open Nat
section Euler
section Legendre
open ZMod
variable (p : ℕ) [Fact p.Prime]
def legendreSym (a : ℤ) : ℤ :=
quadraticChar (ZMod p) a
#align legendre_sym legendreSym
section Values
variable {p : ℕ} [Fact p.Prime]
open ZMod
theorem legendreSym.at_neg_one (hp : p ≠ 2) : legendreSym p (-1) = χ₄ p := by
simp only [legendreSym, card p, quadraticChar_neg_one ((ringChar_zmod_n p).substr hp),
Int.cast_neg, Int.cast_one]
#align legendre_sym.at_neg_one legendreSym.at_neg_one
namespace ZMod
| Mathlib/NumberTheory/LegendreSymbol/Basic.lean | 302 | 303 | theorem exists_sq_eq_neg_one_iff : IsSquare (-1 : ZMod p) ↔ p % 4 ≠ 3 := by |
rw [FiniteField.isSquare_neg_one_iff, card p]
|
import Mathlib.Init.Function
import Mathlib.Init.Order.Defs
#align_import data.bool.basic from "leanprover-community/mathlib"@"c4658a649d216f57e99621708b09dcb3dcccbd23"
namespace Bool
@[deprecated (since := "2024-06-07")] alias decide_True := decide_true_eq_true
#align bool.to_bool_true decide_true_eq_true
@[deprecated (since := "2024-06-07")] alias decide_False := decide_false_eq_false
#align bool.to_bool_false decide_false_eq_false
#align bool.to_bool_coe Bool.decide_coe
@[deprecated (since := "2024-06-07")] alias coe_decide := decide_eq_true_iff
#align bool.coe_to_bool decide_eq_true_iff
@[deprecated decide_eq_true_iff (since := "2024-06-07")]
alias of_decide_iff := decide_eq_true_iff
#align bool.of_to_bool_iff decide_eq_true_iff
#align bool.tt_eq_to_bool_iff true_eq_decide_iff
#align bool.ff_eq_to_bool_iff false_eq_decide_iff
@[deprecated (since := "2024-06-07")] alias decide_not := decide_not
#align bool.to_bool_not decide_not
#align bool.to_bool_and Bool.decide_and
#align bool.to_bool_or Bool.decide_or
#align bool.to_bool_eq decide_eq_decide
@[deprecated (since := "2024-06-07")] alias not_false' := false_ne_true
#align bool.not_ff Bool.false_ne_true
@[deprecated (since := "2024-06-07")] alias eq_iff_eq_true_iff := eq_iff_iff
#align bool.default_bool Bool.default_bool
theorem dichotomy (b : Bool) : b = false ∨ b = true := by cases b <;> simp
#align bool.dichotomy Bool.dichotomy
theorem forall_bool' {p : Bool → Prop} (b : Bool) : (∀ x, p x) ↔ p b ∧ p !b :=
⟨fun h ↦ ⟨h _, h _⟩, fun ⟨h₁, h₂⟩ x ↦ by cases b <;> cases x <;> assumption⟩
@[simp]
theorem forall_bool {p : Bool → Prop} : (∀ b, p b) ↔ p false ∧ p true :=
forall_bool' false
#align bool.forall_bool Bool.forall_bool
theorem exists_bool' {p : Bool → Prop} (b : Bool) : (∃ x, p x) ↔ p b ∨ p !b :=
⟨fun ⟨x, hx⟩ ↦ by cases x <;> cases b <;> first | exact .inl ‹_› | exact .inr ‹_›,
fun h ↦ by cases h <;> exact ⟨_, ‹_›⟩⟩
@[simp]
theorem exists_bool {p : Bool → Prop} : (∃ b, p b) ↔ p false ∨ p true :=
exists_bool' false
#align bool.exists_bool Bool.exists_bool
#align bool.decidable_forall_bool Bool.instDecidableForallOfDecidablePred
#align bool.decidable_exists_bool Bool.instDecidableExistsOfDecidablePred
#align bool.cond_eq_ite Bool.cond_eq_ite
#align bool.cond_to_bool Bool.cond_decide
#align bool.cond_bnot Bool.cond_not
theorem not_ne_id : not ≠ id := fun h ↦ false_ne_true <| congrFun h true
#align bool.bnot_ne_id Bool.not_ne_id
#align bool.coe_bool_iff Bool.coe_iff_coe
@[deprecated (since := "2024-06-07")] alias eq_true_of_ne_false := eq_true_of_ne_false
#align bool.eq_tt_of_ne_ff eq_true_of_ne_false
@[deprecated (since := "2024-06-07")] alias eq_false_of_ne_true := eq_false_of_ne_true
#align bool.eq_ff_of_ne_tt eq_true_of_ne_false
#align bool.bor_comm Bool.or_comm
#align bool.bor_assoc Bool.or_assoc
#align bool.bor_left_comm Bool.or_left_comm
theorem or_inl {a b : Bool} (H : a) : a || b := by simp [H]
#align bool.bor_inl Bool.or_inl
theorem or_inr {a b : Bool} (H : b) : a || b := by cases a <;> simp [H]
#align bool.bor_inr Bool.or_inr
#align bool.band_comm Bool.and_comm
#align bool.band_assoc Bool.and_assoc
#align bool.band_left_comm Bool.and_left_comm
theorem and_elim_left : ∀ {a b : Bool}, a && b → a := by decide
#align bool.band_elim_left Bool.and_elim_left
theorem and_intro : ∀ {a b : Bool}, a → b → a && b := by decide
#align bool.band_intro Bool.and_intro
theorem and_elim_right : ∀ {a b : Bool}, a && b → b := by decide
#align bool.band_elim_right Bool.and_elim_right
#align bool.band_bor_distrib_left Bool.and_or_distrib_left
#align bool.band_bor_distrib_right Bool.and_or_distrib_right
#align bool.bor_band_distrib_left Bool.or_and_distrib_left
#align bool.bor_band_distrib_right Bool.or_and_distrib_right
#align bool.bnot_ff Bool.not_false
#align bool.bnot_tt Bool.not_true
lemma eq_not_iff : ∀ {a b : Bool}, a = !b ↔ a ≠ b := by decide
#align bool.eq_bnot_iff Bool.eq_not_iff
lemma not_eq_iff : ∀ {a b : Bool}, !a = b ↔ a ≠ b := by decide
#align bool.bnot_eq_iff Bool.not_eq_iff
#align bool.not_eq_bnot Bool.not_eq_not
#align bool.bnot_not_eq Bool.not_not_eq
theorem ne_not {a b : Bool} : a ≠ !b ↔ a = b :=
not_eq_not
#align bool.ne_bnot Bool.ne_not
@[deprecated (since := "2024-06-07")] alias not_ne := not_not_eq
#align bool.bnot_ne Bool.not_not_eq
lemma not_ne_self : ∀ b : Bool, (!b) ≠ b := by decide
#align bool.bnot_ne_self Bool.not_ne_self
lemma self_ne_not : ∀ b : Bool, b ≠ !b := by decide
#align bool.self_ne_bnot Bool.self_ne_not
lemma eq_or_eq_not : ∀ a b, a = b ∨ a = !b := by decide
#align bool.eq_or_eq_bnot Bool.eq_or_eq_not
-- Porting note: naming issue again: these two `not` are different.
theorem not_iff_not : ∀ {b : Bool}, !b ↔ ¬b := by simp
#align bool.bnot_iff_not Bool.not_iff_not
theorem eq_true_of_not_eq_false' {a : Bool} : !a = false → a = true := by
cases a <;> decide
#align bool.eq_tt_of_bnot_eq_ff Bool.eq_true_of_not_eq_false'
theorem eq_false_of_not_eq_true' {a : Bool} : !a = true → a = false := by
cases a <;> decide
#align bool.eq_ff_of_bnot_eq_tt Bool.eq_false_of_not_eq_true'
#align bool.band_bnot_self Bool.and_not_self
#align bool.bnot_band_self Bool.not_and_self
#align bool.bor_bnot_self Bool.or_not_self
#align bool.bnot_bor_self Bool.not_or_self
| Mathlib/Data/Bool/Basic.lean | 167 | 167 | theorem bne_eq_xor : bne = xor := by | funext a b; revert a b; decide
|
import Mathlib.Algebra.Group.Equiv.Basic
import Mathlib.Data.ENat.Lattice
import Mathlib.Data.Part
import Mathlib.Tactic.NormNum
#align_import data.nat.part_enat from "leanprover-community/mathlib"@"3ff3f2d6a3118b8711063de7111a0d77a53219a8"
open Part hiding some
def PartENat : Type :=
Part ℕ
#align part_enat PartENat
namespace PartENat
@[coe]
def some : ℕ → PartENat :=
Part.some
#align part_enat.some PartENat.some
instance : Zero PartENat :=
⟨some 0⟩
instance : Inhabited PartENat :=
⟨0⟩
instance : One PartENat :=
⟨some 1⟩
instance : Add PartENat :=
⟨fun x y => ⟨x.Dom ∧ y.Dom, fun h => get x h.1 + get y h.2⟩⟩
instance (n : ℕ) : Decidable (some n).Dom :=
isTrue trivial
@[simp]
theorem dom_some (x : ℕ) : (some x).Dom :=
trivial
#align part_enat.dom_some PartENat.dom_some
instance addCommMonoid : AddCommMonoid PartENat where
add := (· + ·)
zero := 0
add_comm x y := Part.ext' and_comm fun _ _ => add_comm _ _
zero_add x := Part.ext' (true_and_iff _) fun _ _ => zero_add _
add_zero x := Part.ext' (and_true_iff _) fun _ _ => add_zero _
add_assoc x y z := Part.ext' and_assoc fun _ _ => add_assoc _ _ _
nsmul := nsmulRec
instance : AddCommMonoidWithOne PartENat :=
{ PartENat.addCommMonoid with
one := 1
natCast := some
natCast_zero := rfl
natCast_succ := fun _ => Part.ext' (true_and_iff _).symm fun _ _ => rfl }
theorem some_eq_natCast (n : ℕ) : some n = n :=
rfl
#align part_enat.some_eq_coe PartENat.some_eq_natCast
instance : CharZero PartENat where
cast_injective := Part.some_injective
theorem natCast_inj {x y : ℕ} : (x : PartENat) = y ↔ x = y :=
Nat.cast_inj
#align part_enat.coe_inj PartENat.natCast_inj
@[simp]
theorem dom_natCast (x : ℕ) : (x : PartENat).Dom :=
trivial
#align part_enat.dom_coe PartENat.dom_natCast
-- See note [no_index around OfNat.ofNat]
@[simp]
theorem dom_ofNat (x : ℕ) [x.AtLeastTwo] : (no_index (OfNat.ofNat x : PartENat)).Dom :=
trivial
@[simp]
theorem dom_zero : (0 : PartENat).Dom :=
trivial
@[simp]
theorem dom_one : (1 : PartENat).Dom :=
trivial
instance : CanLift PartENat ℕ (↑) Dom :=
⟨fun n hn => ⟨n.get hn, Part.some_get _⟩⟩
instance : LE PartENat :=
⟨fun x y => ∃ h : y.Dom → x.Dom, ∀ hy : y.Dom, x.get (h hy) ≤ y.get hy⟩
instance : Top PartENat :=
⟨none⟩
instance : Bot PartENat :=
⟨0⟩
instance : Sup PartENat :=
⟨fun x y => ⟨x.Dom ∧ y.Dom, fun h => x.get h.1 ⊔ y.get h.2⟩⟩
theorem le_def (x y : PartENat) :
x ≤ y ↔ ∃ h : y.Dom → x.Dom, ∀ hy : y.Dom, x.get (h hy) ≤ y.get hy :=
Iff.rfl
#align part_enat.le_def PartENat.le_def
@[elab_as_elim]
protected theorem casesOn' {P : PartENat → Prop} :
∀ a : PartENat, P ⊤ → (∀ n : ℕ, P (some n)) → P a :=
Part.induction_on
#align part_enat.cases_on' PartENat.casesOn'
@[elab_as_elim]
protected theorem casesOn {P : PartENat → Prop} : ∀ a : PartENat, P ⊤ → (∀ n : ℕ, P n) → P a := by
exact PartENat.casesOn'
#align part_enat.cases_on PartENat.casesOn
-- not a simp lemma as we will provide a `LinearOrderedAddCommMonoidWithTop` instance later
theorem top_add (x : PartENat) : ⊤ + x = ⊤ :=
Part.ext' (false_and_iff _) fun h => h.left.elim
#align part_enat.top_add PartENat.top_add
-- not a simp lemma as we will provide a `LinearOrderedAddCommMonoidWithTop` instance later
theorem add_top (x : PartENat) : x + ⊤ = ⊤ := by rw [add_comm, top_add]
#align part_enat.add_top PartENat.add_top
@[simp]
theorem natCast_get {x : PartENat} (h : x.Dom) : (x.get h : PartENat) = x := by
exact Part.ext' (iff_of_true trivial h) fun _ _ => rfl
#align part_enat.coe_get PartENat.natCast_get
@[simp, norm_cast]
theorem get_natCast' (x : ℕ) (h : (x : PartENat).Dom) : get (x : PartENat) h = x := by
rw [← natCast_inj, natCast_get]
#align part_enat.get_coe' PartENat.get_natCast'
theorem get_natCast {x : ℕ} : get (x : PartENat) (dom_natCast x) = x :=
get_natCast' _ _
#align part_enat.get_coe PartENat.get_natCast
theorem coe_add_get {x : ℕ} {y : PartENat} (h : ((x : PartENat) + y).Dom) :
get ((x : PartENat) + y) h = x + get y h.2 := by
rfl
#align part_enat.coe_add_get PartENat.coe_add_get
@[simp]
theorem get_add {x y : PartENat} (h : (x + y).Dom) : get (x + y) h = x.get h.1 + y.get h.2 :=
rfl
#align part_enat.get_add PartENat.get_add
@[simp]
theorem get_zero (h : (0 : PartENat).Dom) : (0 : PartENat).get h = 0 :=
rfl
#align part_enat.get_zero PartENat.get_zero
@[simp]
theorem get_one (h : (1 : PartENat).Dom) : (1 : PartENat).get h = 1 :=
rfl
#align part_enat.get_one PartENat.get_one
-- See note [no_index around OfNat.ofNat]
@[simp]
theorem get_ofNat' (x : ℕ) [x.AtLeastTwo] (h : (no_index (OfNat.ofNat x : PartENat)).Dom) :
Part.get (no_index (OfNat.ofNat x : PartENat)) h = (no_index (OfNat.ofNat x)) :=
get_natCast' x h
nonrec theorem get_eq_iff_eq_some {a : PartENat} {ha : a.Dom} {b : ℕ} : a.get ha = b ↔ a = some b :=
get_eq_iff_eq_some
#align part_enat.get_eq_iff_eq_some PartENat.get_eq_iff_eq_some
theorem get_eq_iff_eq_coe {a : PartENat} {ha : a.Dom} {b : ℕ} : a.get ha = b ↔ a = b := by
rw [get_eq_iff_eq_some]
rfl
#align part_enat.get_eq_iff_eq_coe PartENat.get_eq_iff_eq_coe
theorem dom_of_le_of_dom {x y : PartENat} : x ≤ y → y.Dom → x.Dom := fun ⟨h, _⟩ => h
#align part_enat.dom_of_le_of_dom PartENat.dom_of_le_of_dom
theorem dom_of_le_some {x : PartENat} {y : ℕ} (h : x ≤ some y) : x.Dom :=
dom_of_le_of_dom h trivial
#align part_enat.dom_of_le_some PartENat.dom_of_le_some
theorem dom_of_le_natCast {x : PartENat} {y : ℕ} (h : x ≤ y) : x.Dom := by
exact dom_of_le_some h
#align part_enat.dom_of_le_coe PartENat.dom_of_le_natCast
instance decidableLe (x y : PartENat) [Decidable x.Dom] [Decidable y.Dom] : Decidable (x ≤ y) :=
if hx : x.Dom then
decidable_of_decidable_of_iff (by rw [le_def])
else
if hy : y.Dom then isFalse fun h => hx <| dom_of_le_of_dom h hy
else isTrue ⟨fun h => (hy h).elim, fun h => (hy h).elim⟩
#align part_enat.decidable_le PartENat.decidableLe
-- Porting note: Removed. Use `Nat.castAddMonoidHom` instead.
#noalign part_enat.coe_hom
#noalign part_enat.coe_coe_hom
instance partialOrder : PartialOrder PartENat where
le := (· ≤ ·)
le_refl _ := ⟨id, fun _ => le_rfl⟩
le_trans := fun _ _ _ ⟨hxy₁, hxy₂⟩ ⟨hyz₁, hyz₂⟩ =>
⟨hxy₁ ∘ hyz₁, fun _ => le_trans (hxy₂ _) (hyz₂ _)⟩
lt_iff_le_not_le _ _ := Iff.rfl
le_antisymm := fun _ _ ⟨hxy₁, hxy₂⟩ ⟨hyx₁, hyx₂⟩ =>
Part.ext' ⟨hyx₁, hxy₁⟩ fun _ _ => le_antisymm (hxy₂ _) (hyx₂ _)
theorem lt_def (x y : PartENat) : x < y ↔ ∃ hx : x.Dom, ∀ hy : y.Dom, x.get hx < y.get hy := by
rw [lt_iff_le_not_le, le_def, le_def, not_exists]
constructor
· rintro ⟨⟨hyx, H⟩, h⟩
by_cases hx : x.Dom
· use hx
intro hy
specialize H hy
specialize h fun _ => hy
rw [not_forall] at h
cases' h with hx' h
rw [not_le] at h
exact h
· specialize h fun hx' => (hx hx').elim
rw [not_forall] at h
cases' h with hx' h
exact (hx hx').elim
· rintro ⟨hx, H⟩
exact ⟨⟨fun _ => hx, fun hy => (H hy).le⟩, fun hxy h => not_lt_of_le (h _) (H _)⟩
#align part_enat.lt_def PartENat.lt_def
noncomputable instance orderedAddCommMonoid : OrderedAddCommMonoid PartENat :=
{ PartENat.partialOrder, PartENat.addCommMonoid with
add_le_add_left := fun a b ⟨h₁, h₂⟩ c =>
PartENat.casesOn c (by simp [top_add]) fun c =>
⟨fun h => And.intro (dom_natCast _) (h₁ h.2), fun h => by
simpa only [coe_add_get] using add_le_add_left (h₂ _) c⟩ }
instance semilatticeSup : SemilatticeSup PartENat :=
{ PartENat.partialOrder with
sup := (· ⊔ ·)
le_sup_left := fun _ _ => ⟨And.left, fun _ => le_sup_left⟩
le_sup_right := fun _ _ => ⟨And.right, fun _ => le_sup_right⟩
sup_le := fun _ _ _ ⟨hx₁, hx₂⟩ ⟨hy₁, hy₂⟩ =>
⟨fun hz => ⟨hx₁ hz, hy₁ hz⟩, fun _ => sup_le (hx₂ _) (hy₂ _)⟩ }
#align part_enat.semilattice_sup PartENat.semilatticeSup
instance orderBot : OrderBot PartENat where
bot := ⊥
bot_le _ := ⟨fun _ => trivial, fun _ => Nat.zero_le _⟩
#align part_enat.order_bot PartENat.orderBot
instance orderTop : OrderTop PartENat where
top := ⊤
le_top _ := ⟨fun h => False.elim h, fun hy => False.elim hy⟩
#align part_enat.order_top PartENat.orderTop
instance : ZeroLEOneClass PartENat where
zero_le_one := bot_le
theorem coe_le_coe {x y : ℕ} : (x : PartENat) ≤ y ↔ x ≤ y := Nat.cast_le
#align part_enat.coe_le_coe PartENat.coe_le_coe
theorem coe_lt_coe {x y : ℕ} : (x : PartENat) < y ↔ x < y := Nat.cast_lt
#align part_enat.coe_lt_coe PartENat.coe_lt_coe
@[simp]
theorem get_le_get {x y : PartENat} {hx : x.Dom} {hy : y.Dom} : x.get hx ≤ y.get hy ↔ x ≤ y := by
conv =>
lhs
rw [← coe_le_coe, natCast_get, natCast_get]
#align part_enat.get_le_get PartENat.get_le_get
theorem le_coe_iff (x : PartENat) (n : ℕ) : x ≤ n ↔ ∃ h : x.Dom, x.get h ≤ n := by
show (∃ h : True → x.Dom, _) ↔ ∃ h : x.Dom, x.get h ≤ n
simp only [forall_prop_of_true, dom_natCast, get_natCast']
#align part_enat.le_coe_iff PartENat.le_coe_iff
| Mathlib/Data/Nat/PartENat.lean | 329 | 330 | theorem lt_coe_iff (x : PartENat) (n : ℕ) : x < n ↔ ∃ h : x.Dom, x.get h < n := by |
simp only [lt_def, forall_prop_of_true, get_natCast', dom_natCast]
|
import Mathlib.LinearAlgebra.CliffordAlgebra.Conjugation
import Mathlib.LinearAlgebra.CliffordAlgebra.Even
import Mathlib.LinearAlgebra.QuadraticForm.Prod
import Mathlib.Tactic.LiftLets
#align_import linear_algebra.clifford_algebra.even_equiv from "leanprover-community/mathlib"@"2196ab363eb097c008d4497125e0dde23fb36db2"
namespace CliffordAlgebra
variable {R M : Type*} [CommRing R] [AddCommGroup M] [Module R M]
variable (Q : QuadraticForm R M)
namespace EquivEven
abbrev Q' : QuadraticForm R (M × R) :=
Q.prod <| -@QuadraticForm.sq R _
set_option linter.uppercaseLean3 false in
#align clifford_algebra.equiv_even.Q' CliffordAlgebra.EquivEven.Q'
theorem Q'_apply (m : M × R) : Q' Q m = Q m.1 - m.2 * m.2 :=
(sub_eq_add_neg _ _).symm
set_option linter.uppercaseLean3 false in
#align clifford_algebra.equiv_even.Q'_apply CliffordAlgebra.EquivEven.Q'_apply
def e0 : CliffordAlgebra (Q' Q) :=
ι (Q' Q) (0, 1)
#align clifford_algebra.equiv_even.e0 CliffordAlgebra.EquivEven.e0
def v : M →ₗ[R] CliffordAlgebra (Q' Q) :=
ι (Q' Q) ∘ₗ LinearMap.inl _ _ _
#align clifford_algebra.equiv_even.v CliffordAlgebra.EquivEven.v
| Mathlib/LinearAlgebra/CliffordAlgebra/EvenEquiv.lean | 69 | 71 | theorem ι_eq_v_add_smul_e0 (m : M) (r : R) : ι (Q' Q) (m, r) = v Q m + r • e0 Q := by |
rw [e0, v, LinearMap.comp_apply, LinearMap.inl_apply, ← LinearMap.map_smul, Prod.smul_mk,
smul_zero, smul_eq_mul, mul_one, ← LinearMap.map_add, Prod.mk_add_mk, zero_add, add_zero]
|
import Mathlib.RingTheory.IntegralClosure
import Mathlib.RingTheory.FractionalIdeal.Basic
#align_import ring_theory.fractional_ideal from "leanprover-community/mathlib"@"ed90a7d327c3a5caf65a6faf7e8a0d63c4605df7"
open IsLocalization Pointwise nonZeroDivisors
namespace FractionalIdeal
open Set Submodule
variable {R : Type*} [CommRing R] {S : Submonoid R} {P : Type*} [CommRing P]
variable [Algebra R P] [loc : IsLocalization S P]
section
variable {P' : Type*} [CommRing P'] [Algebra R P'] [loc' : IsLocalization S P']
variable {P'' : Type*} [CommRing P''] [Algebra R P''] [loc'' : IsLocalization S P'']
theorem _root_.IsFractional.map (g : P →ₐ[R] P') {I : Submodule R P} :
IsFractional S I → IsFractional S (Submodule.map g.toLinearMap I)
| ⟨a, a_nonzero, hI⟩ =>
⟨a, a_nonzero, fun b hb => by
obtain ⟨b', b'_mem, hb'⟩ := Submodule.mem_map.mp hb
rw [AlgHom.toLinearMap_apply] at hb'
obtain ⟨x, hx⟩ := hI b' b'_mem
use x
rw [← g.commutes, hx, g.map_smul, hb']⟩
#align is_fractional.map IsFractional.map
def map (g : P →ₐ[R] P') : FractionalIdeal S P → FractionalIdeal S P' := fun I =>
⟨Submodule.map g.toLinearMap I, I.isFractional.map g⟩
#align fractional_ideal.map FractionalIdeal.map
@[simp, norm_cast]
theorem coe_map (g : P →ₐ[R] P') (I : FractionalIdeal S P) :
↑(map g I) = Submodule.map g.toLinearMap I :=
rfl
#align fractional_ideal.coe_map FractionalIdeal.coe_map
@[simp]
theorem mem_map {I : FractionalIdeal S P} {g : P →ₐ[R] P'} {y : P'} :
y ∈ I.map g ↔ ∃ x, x ∈ I ∧ g x = y :=
Submodule.mem_map
#align fractional_ideal.mem_map FractionalIdeal.mem_map
variable (I J : FractionalIdeal S P) (g : P →ₐ[R] P')
@[simp]
theorem map_id : I.map (AlgHom.id _ _) = I :=
coeToSubmodule_injective (Submodule.map_id (I : Submodule R P))
#align fractional_ideal.map_id FractionalIdeal.map_id
@[simp]
theorem map_comp (g' : P' →ₐ[R] P'') : I.map (g'.comp g) = (I.map g).map g' :=
coeToSubmodule_injective (Submodule.map_comp g.toLinearMap g'.toLinearMap I)
#align fractional_ideal.map_comp FractionalIdeal.map_comp
@[simp, norm_cast]
theorem map_coeIdeal (I : Ideal R) : (I : FractionalIdeal S P).map g = I := by
ext x
simp only [mem_coeIdeal]
constructor
· rintro ⟨_, ⟨y, hy, rfl⟩, rfl⟩
exact ⟨y, hy, (g.commutes y).symm⟩
· rintro ⟨y, hy, rfl⟩
exact ⟨_, ⟨y, hy, rfl⟩, g.commutes y⟩
#align fractional_ideal.map_coe_ideal FractionalIdeal.map_coeIdeal
@[simp]
theorem map_one : (1 : FractionalIdeal S P).map g = 1 :=
map_coeIdeal g ⊤
#align fractional_ideal.map_one FractionalIdeal.map_one
@[simp]
theorem map_zero : (0 : FractionalIdeal S P).map g = 0 :=
map_coeIdeal g 0
#align fractional_ideal.map_zero FractionalIdeal.map_zero
@[simp]
theorem map_add : (I + J).map g = I.map g + J.map g :=
coeToSubmodule_injective (Submodule.map_sup _ _ _)
#align fractional_ideal.map_add FractionalIdeal.map_add
@[simp]
theorem map_mul : (I * J).map g = I.map g * J.map g := by
simp only [mul_def]
exact coeToSubmodule_injective (Submodule.map_mul _ _ _)
#align fractional_ideal.map_mul FractionalIdeal.map_mul
@[simp]
theorem map_map_symm (g : P ≃ₐ[R] P') : (I.map (g : P →ₐ[R] P')).map (g.symm : P' →ₐ[R] P) = I := by
rw [← map_comp, g.symm_comp, map_id]
#align fractional_ideal.map_map_symm FractionalIdeal.map_map_symm
@[simp]
theorem map_symm_map (I : FractionalIdeal S P') (g : P ≃ₐ[R] P') :
(I.map (g.symm : P' →ₐ[R] P)).map (g : P →ₐ[R] P') = I := by
rw [← map_comp, g.comp_symm, map_id]
#align fractional_ideal.map_symm_map FractionalIdeal.map_symm_map
theorem map_mem_map {f : P →ₐ[R] P'} (h : Function.Injective f) {x : P} {I : FractionalIdeal S P} :
f x ∈ map f I ↔ x ∈ I :=
mem_map.trans ⟨fun ⟨_, hx', x'_eq⟩ => h x'_eq ▸ hx', fun h => ⟨x, h, rfl⟩⟩
#align fractional_ideal.map_mem_map FractionalIdeal.map_mem_map
theorem map_injective (f : P →ₐ[R] P') (h : Function.Injective f) :
Function.Injective (map f : FractionalIdeal S P → FractionalIdeal S P') := fun _ _ hIJ =>
ext fun _ => (map_mem_map h).symm.trans (hIJ.symm ▸ map_mem_map h)
#align fractional_ideal.map_injective FractionalIdeal.map_injective
def mapEquiv (g : P ≃ₐ[R] P') : FractionalIdeal S P ≃+* FractionalIdeal S P' where
toFun := map g
invFun := map g.symm
map_add' I J := map_add I J _
map_mul' I J := map_mul I J _
left_inv I := by rw [← map_comp, AlgEquiv.symm_comp, map_id]
right_inv I := by rw [← map_comp, AlgEquiv.comp_symm, map_id]
#align fractional_ideal.map_equiv FractionalIdeal.mapEquiv
@[simp]
theorem coeFun_mapEquiv (g : P ≃ₐ[R] P') :
(mapEquiv g : FractionalIdeal S P → FractionalIdeal S P') = map g :=
rfl
#align fractional_ideal.coe_fun_map_equiv FractionalIdeal.coeFun_mapEquiv
@[simp]
theorem mapEquiv_apply (g : P ≃ₐ[R] P') (I : FractionalIdeal S P) : mapEquiv g I = map (↑g) I :=
rfl
#align fractional_ideal.map_equiv_apply FractionalIdeal.mapEquiv_apply
@[simp]
theorem mapEquiv_symm (g : P ≃ₐ[R] P') :
((mapEquiv g).symm : FractionalIdeal S P' ≃+* _) = mapEquiv g.symm :=
rfl
#align fractional_ideal.map_equiv_symm FractionalIdeal.mapEquiv_symm
@[simp]
theorem mapEquiv_refl : mapEquiv AlgEquiv.refl = RingEquiv.refl (FractionalIdeal S P) :=
RingEquiv.ext fun x => by simp
#align fractional_ideal.map_equiv_refl FractionalIdeal.mapEquiv_refl
theorem isFractional_span_iff {s : Set P} :
IsFractional S (span R s) ↔ ∃ a ∈ S, ∀ b : P, b ∈ s → IsInteger R (a • b) :=
⟨fun ⟨a, a_mem, h⟩ => ⟨a, a_mem, fun b hb => h b (subset_span hb)⟩, fun ⟨a, a_mem, h⟩ =>
⟨a, a_mem, fun b hb =>
span_induction hb h
(by
rw [smul_zero]
exact isInteger_zero)
(fun x y hx hy => by
rw [smul_add]
exact isInteger_add hx hy)
fun s x hx => by
rw [smul_comm]
exact isInteger_smul hx⟩⟩
#align fractional_ideal.is_fractional_span_iff FractionalIdeal.isFractional_span_iff
theorem isFractional_of_fg {I : Submodule R P} (hI : I.FG) : IsFractional S I := by
rcases hI with ⟨I, rfl⟩
rcases exist_integer_multiples_of_finset S I with ⟨⟨s, hs1⟩, hs⟩
rw [isFractional_span_iff]
exact ⟨s, hs1, hs⟩
#align fractional_ideal.is_fractional_of_fg FractionalIdeal.isFractional_of_fg
theorem mem_span_mul_finite_of_mem_mul {I J : FractionalIdeal S P} {x : P} (hx : x ∈ I * J) :
∃ T T' : Finset P, (T : Set P) ⊆ I ∧ (T' : Set P) ⊆ J ∧ x ∈ span R (T * T' : Set P) :=
Submodule.mem_span_mul_finite_of_mem_mul (by simpa using mem_coe.mpr hx)
#align fractional_ideal.mem_span_mul_finite_of_mem_mul FractionalIdeal.mem_span_mul_finite_of_mem_mul
variable (S)
theorem coeIdeal_fg (inj : Function.Injective (algebraMap R P)) (I : Ideal R) :
FG ((I : FractionalIdeal S P) : Submodule R P) ↔ I.FG :=
coeSubmodule_fg _ inj _
#align fractional_ideal.coe_ideal_fg FractionalIdeal.coeIdeal_fg
variable {S}
theorem fg_unit (I : (FractionalIdeal S P)ˣ) : FG (I : Submodule R P) :=
Submodule.fg_unit <| Units.map (coeSubmoduleHom S P).toMonoidHom I
#align fractional_ideal.fg_unit FractionalIdeal.fg_unit
theorem fg_of_isUnit (I : FractionalIdeal S P) (h : IsUnit I) : FG (I : Submodule R P) :=
fg_unit h.unit
#align fractional_ideal.fg_of_is_unit FractionalIdeal.fg_of_isUnit
theorem _root_.Ideal.fg_of_isUnit (inj : Function.Injective (algebraMap R P)) (I : Ideal R)
(h : IsUnit (I : FractionalIdeal S P)) : I.FG := by
rw [← coeIdeal_fg S inj I]
exact FractionalIdeal.fg_of_isUnit I h
#align ideal.fg_of_is_unit Ideal.fg_of_isUnit
variable (S P P')
noncomputable irreducible_def canonicalEquiv : FractionalIdeal S P ≃+* FractionalIdeal S P' :=
mapEquiv
{ ringEquivOfRingEquiv P P' (RingEquiv.refl R)
(show S.map _ = S by rw [RingEquiv.toMonoidHom_refl, Submonoid.map_id]) with
commutes' := fun r => ringEquivOfRingEquiv_eq _ _ }
#align fractional_ideal.canonical_equiv FractionalIdeal.canonicalEquiv
@[simp]
theorem mem_canonicalEquiv_apply {I : FractionalIdeal S P} {x : P'} :
x ∈ canonicalEquiv S P P' I ↔
∃ y ∈ I,
IsLocalization.map P' (RingHom.id R) (fun y (hy : y ∈ S) => show RingHom.id R y ∈ S from hy)
(y : P) =
x := by
rw [canonicalEquiv, mapEquiv_apply, mem_map]
exact ⟨fun ⟨y, mem, Eq⟩ => ⟨y, mem, Eq⟩, fun ⟨y, mem, Eq⟩ => ⟨y, mem, Eq⟩⟩
#align fractional_ideal.mem_canonical_equiv_apply FractionalIdeal.mem_canonicalEquiv_apply
@[simp]
theorem canonicalEquiv_symm : (canonicalEquiv S P P').symm = canonicalEquiv S P' P :=
RingEquiv.ext fun I =>
SetLike.ext_iff.mpr fun x => by
rw [mem_canonicalEquiv_apply, canonicalEquiv, mapEquiv_symm, mapEquiv_apply,
mem_map]
exact ⟨fun ⟨y, mem, Eq⟩ => ⟨y, mem, Eq⟩, fun ⟨y, mem, Eq⟩ => ⟨y, mem, Eq⟩⟩
#align fractional_ideal.canonical_equiv_symm FractionalIdeal.canonicalEquiv_symm
theorem canonicalEquiv_flip (I) : canonicalEquiv S P P' (canonicalEquiv S P' P I) = I := by
rw [← canonicalEquiv_symm]; erw [RingEquiv.apply_symm_apply]
#align fractional_ideal.canonical_equiv_flip FractionalIdeal.canonicalEquiv_flip
@[simp]
theorem canonicalEquiv_canonicalEquiv (P'' : Type*) [CommRing P''] [Algebra R P'']
[IsLocalization S P''] (I : FractionalIdeal S P) :
canonicalEquiv S P' P'' (canonicalEquiv S P P' I) = canonicalEquiv S P P'' I := by
ext
simp only [IsLocalization.map_map, RingHomInvPair.comp_eq₂, mem_canonicalEquiv_apply,
exists_prop, exists_exists_and_eq_and]
#align fractional_ideal.canonical_equiv_canonical_equiv FractionalIdeal.canonicalEquiv_canonicalEquiv
theorem canonicalEquiv_trans_canonicalEquiv (P'' : Type*) [CommRing P''] [Algebra R P'']
[IsLocalization S P''] :
(canonicalEquiv S P P').trans (canonicalEquiv S P' P'') = canonicalEquiv S P P'' :=
RingEquiv.ext (canonicalEquiv_canonicalEquiv S P P' P'')
#align fractional_ideal.canonical_equiv_trans_canonical_equiv FractionalIdeal.canonicalEquiv_trans_canonicalEquiv
@[simp]
theorem canonicalEquiv_coeIdeal (I : Ideal R) : canonicalEquiv S P P' I = I := by
ext
simp [IsLocalization.map_eq]
#align fractional_ideal.canonical_equiv_coe_ideal FractionalIdeal.canonicalEquiv_coeIdeal
@[simp]
theorem canonicalEquiv_self : canonicalEquiv S P P = RingEquiv.refl _ := by
rw [← canonicalEquiv_trans_canonicalEquiv S P P]
convert (canonicalEquiv S P P).symm_trans_self
exact (canonicalEquiv_symm S P P).symm
#align fractional_ideal.canonical_equiv_self FractionalIdeal.canonicalEquiv_self
end
section IsFractionRing
variable {K K' : Type*} [Field K] [Field K']
variable [Algebra R K] [IsFractionRing R K] [Algebra R K'] [IsFractionRing R K']
variable {I J : FractionalIdeal R⁰ K} (h : K →ₐ[R] K')
theorem exists_ne_zero_mem_isInteger [Nontrivial R] (hI : I ≠ 0) :
∃ x, x ≠ 0 ∧ algebraMap R K x ∈ I := by
obtain ⟨y : K, y_mem, y_not_mem⟩ :=
SetLike.exists_of_lt (by simpa only using bot_lt_iff_ne_bot.mpr hI)
have y_ne_zero : y ≠ 0 := by simpa using y_not_mem
obtain ⟨z, ⟨x, hx⟩⟩ := exists_integer_multiple R⁰ y
refine ⟨x, ?_, ?_⟩
· rw [Ne, ← @IsFractionRing.to_map_eq_zero_iff R _ K, hx, Algebra.smul_def]
exact mul_ne_zero (IsFractionRing.to_map_ne_zero_of_mem_nonZeroDivisors z.2) y_ne_zero
· rw [hx]
exact smul_mem _ _ y_mem
#align fractional_ideal.exists_ne_zero_mem_is_integer FractionalIdeal.exists_ne_zero_mem_isInteger
theorem map_ne_zero [Nontrivial R] (hI : I ≠ 0) : I.map h ≠ 0 := by
obtain ⟨x, x_ne_zero, hx⟩ := exists_ne_zero_mem_isInteger hI
contrapose! x_ne_zero with map_eq_zero
refine IsFractionRing.to_map_eq_zero_iff.mp (eq_zero_iff.mp map_eq_zero _ (mem_map.mpr ?_))
exact ⟨algebraMap R K x, hx, h.commutes x⟩
#align fractional_ideal.map_ne_zero FractionalIdeal.map_ne_zero
@[simp]
theorem map_eq_zero_iff [Nontrivial R] : I.map h = 0 ↔ I = 0 :=
⟨not_imp_not.mp (map_ne_zero _), fun hI => hI.symm ▸ map_zero h⟩
#align fractional_ideal.map_eq_zero_iff FractionalIdeal.map_eq_zero_iff
theorem coeIdeal_injective : Function.Injective (fun (I : Ideal R) ↦ (I : FractionalIdeal R⁰ K)) :=
coeIdeal_injective' le_rfl
#align fractional_ideal.coe_ideal_injective FractionalIdeal.coeIdeal_injective
theorem coeIdeal_inj {I J : Ideal R} :
(I : FractionalIdeal R⁰ K) = (J : FractionalIdeal R⁰ K) ↔ I = J :=
coeIdeal_inj' le_rfl
#align fractional_ideal.coe_ideal_inj FractionalIdeal.coeIdeal_inj
@[simp]
theorem coeIdeal_eq_zero {I : Ideal R} : (I : FractionalIdeal R⁰ K) = 0 ↔ I = ⊥ :=
coeIdeal_eq_zero' le_rfl
#align fractional_ideal.coe_ideal_eq_zero FractionalIdeal.coeIdeal_eq_zero
theorem coeIdeal_ne_zero {I : Ideal R} : (I : FractionalIdeal R⁰ K) ≠ 0 ↔ I ≠ ⊥ :=
coeIdeal_ne_zero' le_rfl
#align fractional_ideal.coe_ideal_ne_zero FractionalIdeal.coeIdeal_ne_zero
@[simp]
| Mathlib/RingTheory/FractionalIdeal/Operations.lean | 350 | 351 | theorem coeIdeal_eq_one {I : Ideal R} : (I : FractionalIdeal R⁰ K) = 1 ↔ I = 1 := by |
simpa only [Ideal.one_eq_top] using coeIdeal_inj
|
import Mathlib.Probability.Kernel.Composition
import Mathlib.MeasureTheory.Integral.SetIntegral
#align_import probability.kernel.integral_comp_prod from "leanprover-community/mathlib"@"c0d694db494dd4f9aa57f2714b6e4c82b4ebc113"
noncomputable section
open scoped Topology ENNReal MeasureTheory ProbabilityTheory
open Set Function Real ENNReal MeasureTheory Filter ProbabilityTheory ProbabilityTheory.kernel
variable {α β γ E : Type*} {mα : MeasurableSpace α} {mβ : MeasurableSpace β}
{mγ : MeasurableSpace γ} [NormedAddCommGroup E] {κ : kernel α β} [IsSFiniteKernel κ]
{η : kernel (α × β) γ} [IsSFiniteKernel η] {a : α}
namespace ProbabilityTheory
theorem hasFiniteIntegral_prod_mk_left (a : α) {s : Set (β × γ)} (h2s : (κ ⊗ₖ η) a s ≠ ∞) :
HasFiniteIntegral (fun b => (η (a, b) (Prod.mk b ⁻¹' s)).toReal) (κ a) := by
let t := toMeasurable ((κ ⊗ₖ η) a) s
simp_rw [HasFiniteIntegral, ennnorm_eq_ofReal toReal_nonneg]
calc
∫⁻ b, ENNReal.ofReal (η (a, b) (Prod.mk b ⁻¹' s)).toReal ∂κ a
_ ≤ ∫⁻ b, η (a, b) (Prod.mk b ⁻¹' t) ∂κ a := by
refine lintegral_mono_ae ?_
filter_upwards [ae_kernel_lt_top a h2s] with b hb
rw [ofReal_toReal hb.ne]
exact measure_mono (preimage_mono (subset_toMeasurable _ _))
_ ≤ (κ ⊗ₖ η) a t := le_compProd_apply _ _ _ _
_ = (κ ⊗ₖ η) a s := measure_toMeasurable s
_ < ⊤ := h2s.lt_top
#align probability_theory.has_finite_integral_prod_mk_left ProbabilityTheory.hasFiniteIntegral_prod_mk_left
| Mathlib/Probability/Kernel/IntegralCompProd.lean | 64 | 68 | theorem integrable_kernel_prod_mk_left (a : α) {s : Set (β × γ)} (hs : MeasurableSet s)
(h2s : (κ ⊗ₖ η) a s ≠ ∞) : Integrable (fun b => (η (a, b) (Prod.mk b ⁻¹' s)).toReal) (κ a) := by |
constructor
· exact (measurable_kernel_prod_mk_left' hs a).ennreal_toReal.aestronglyMeasurable
· exact hasFiniteIntegral_prod_mk_left a h2s
|
import Mathlib.CategoryTheory.Subobject.Lattice
#align_import category_theory.subobject.limits from "leanprover-community/mathlib"@"956af7c76589f444f2e1313911bad16366ea476d"
universe v u
noncomputable section
open CategoryTheory CategoryTheory.Category CategoryTheory.Limits CategoryTheory.Subobject Opposite
variable {C : Type u} [Category.{v} C] {X Y Z : C}
namespace CategoryTheory
namespace Limits
section Image
variable (f : X ⟶ Y) [HasImage f]
abbrev imageSubobject : Subobject Y :=
Subobject.mk (image.ι f)
#align category_theory.limits.image_subobject CategoryTheory.Limits.imageSubobject
def imageSubobjectIso : (imageSubobject f : C) ≅ image f :=
Subobject.underlyingIso (image.ι f)
#align category_theory.limits.image_subobject_iso CategoryTheory.Limits.imageSubobjectIso
@[reassoc (attr := simp)]
theorem imageSubobject_arrow :
(imageSubobjectIso f).hom ≫ image.ι f = (imageSubobject f).arrow := by simp [imageSubobjectIso]
#align category_theory.limits.image_subobject_arrow CategoryTheory.Limits.imageSubobject_arrow
@[reassoc (attr := simp)]
theorem imageSubobject_arrow' :
(imageSubobjectIso f).inv ≫ (imageSubobject f).arrow = image.ι f := by simp [imageSubobjectIso]
#align category_theory.limits.image_subobject_arrow' CategoryTheory.Limits.imageSubobject_arrow'
def factorThruImageSubobject : X ⟶ imageSubobject f :=
factorThruImage f ≫ (imageSubobjectIso f).inv
#align category_theory.limits.factor_thru_image_subobject CategoryTheory.Limits.factorThruImageSubobject
instance [HasEqualizers C] : Epi (factorThruImageSubobject f) := by
dsimp [factorThruImageSubobject]
apply epi_comp
@[reassoc (attr := simp), elementwise (attr := simp)]
theorem imageSubobject_arrow_comp : factorThruImageSubobject f ≫ (imageSubobject f).arrow = f := by
simp [factorThruImageSubobject, imageSubobject_arrow]
#align category_theory.limits.image_subobject_arrow_comp CategoryTheory.Limits.imageSubobject_arrow_comp
theorem imageSubobject_arrow_comp_eq_zero [HasZeroMorphisms C] {X Y Z : C} {f : X ⟶ Y} {g : Y ⟶ Z}
[HasImage f] [Epi (factorThruImageSubobject f)] (h : f ≫ g = 0) :
(imageSubobject f).arrow ≫ g = 0 :=
zero_of_epi_comp (factorThruImageSubobject f) <| by simp [h]
#align category_theory.limits.image_subobject_arrow_comp_eq_zero CategoryTheory.Limits.imageSubobject_arrow_comp_eq_zero
theorem imageSubobject_factors_comp_self {W : C} (k : W ⟶ X) : (imageSubobject f).Factors (k ≫ f) :=
⟨k ≫ factorThruImage f, by simp⟩
#align category_theory.limits.image_subobject_factors_comp_self CategoryTheory.Limits.imageSubobject_factors_comp_self
@[simp]
theorem factorThruImageSubobject_comp_self {W : C} (k : W ⟶ X) (h) :
(imageSubobject f).factorThru (k ≫ f) h = k ≫ factorThruImageSubobject f := by
ext
simp
#align category_theory.limits.factor_thru_image_subobject_comp_self CategoryTheory.Limits.factorThruImageSubobject_comp_self
@[simp]
theorem factorThruImageSubobject_comp_self_assoc {W W' : C} (k : W ⟶ W') (k' : W' ⟶ X) (h) :
(imageSubobject f).factorThru (k ≫ k' ≫ f) h = k ≫ k' ≫ factorThruImageSubobject f := by
ext
simp
#align category_theory.limits.factor_thru_image_subobject_comp_self_assoc CategoryTheory.Limits.factorThruImageSubobject_comp_self_assoc
theorem imageSubobject_comp_le {X' : C} (h : X' ⟶ X) (f : X ⟶ Y) [HasImage f] [HasImage (h ≫ f)] :
imageSubobject (h ≫ f) ≤ imageSubobject f :=
Subobject.mk_le_mk_of_comm (image.preComp h f) (by simp)
#align category_theory.limits.image_subobject_comp_le CategoryTheory.Limits.imageSubobject_comp_le
section
open ZeroObject
variable [HasZeroMorphisms C] [HasZeroObject C]
@[simp]
theorem imageSubobject_zero_arrow : (imageSubobject (0 : X ⟶ Y)).arrow = 0 := by
rw [← imageSubobject_arrow]
simp
#align category_theory.limits.image_subobject_zero_arrow CategoryTheory.Limits.imageSubobject_zero_arrow
@[simp]
theorem imageSubobject_zero {A B : C} : imageSubobject (0 : A ⟶ B) = ⊥ :=
Subobject.eq_of_comm (imageSubobjectIso _ ≪≫ imageZero ≪≫ Subobject.botCoeIsoZero.symm) (by simp)
#align category_theory.limits.image_subobject_zero CategoryTheory.Limits.imageSubobject_zero
end
section
variable [HasEqualizers C]
attribute [local instance] epi_comp
instance imageSubobject_comp_le_epi_of_epi {X' : C} (h : X' ⟶ X) [Epi h] (f : X ⟶ Y) [HasImage f]
[HasImage (h ≫ f)] : Epi (Subobject.ofLE _ _ (imageSubobject_comp_le h f)) := by
rw [ofLE_mk_le_mk_of_comm (image.preComp h f)]
· infer_instance
· simp
#align category_theory.limits.image_subobject_comp_le_epi_of_epi CategoryTheory.Limits.imageSubobject_comp_le_epi_of_epi
end
section
variable [HasEqualizers C]
def imageSubobjectCompIso (f : X ⟶ Y) [HasImage f] {Y' : C} (h : Y ⟶ Y') [IsIso h] :
(imageSubobject (f ≫ h) : C) ≅ (imageSubobject f : C) :=
imageSubobjectIso _ ≪≫ (image.compIso _ _).symm ≪≫ (imageSubobjectIso _).symm
#align category_theory.limits.image_subobject_comp_iso CategoryTheory.Limits.imageSubobjectCompIso
@[reassoc (attr := simp)]
| Mathlib/CategoryTheory/Subobject/Limits.lean | 412 | 415 | theorem imageSubobjectCompIso_hom_arrow (f : X ⟶ Y) [HasImage f] {Y' : C} (h : Y ⟶ Y') [IsIso h] :
(imageSubobjectCompIso f h).hom ≫ (imageSubobject f).arrow =
(imageSubobject (f ≫ h)).arrow ≫ inv h := by |
simp [imageSubobjectCompIso]
|
import Mathlib.Algebra.MvPolynomial.Funext
import Mathlib.Algebra.Ring.ULift
import Mathlib.RingTheory.WittVector.Basic
#align_import ring_theory.witt_vector.is_poly from "leanprover-community/mathlib"@"48fb5b5280e7c81672afc9524185ae994553ebf4"
namespace WittVector
universe u
variable {p : ℕ} {R S : Type u} {σ idx : Type*} [CommRing R] [CommRing S]
local notation "𝕎" => WittVector p -- type as `\bbW`
open MvPolynomial
open Function (uncurry)
variable (p)
noncomputable section
theorem poly_eq_of_wittPolynomial_bind_eq' [Fact p.Prime] (f g : ℕ → MvPolynomial (idx × ℕ) ℤ)
(h : ∀ n, bind₁ f (wittPolynomial p _ n) = bind₁ g (wittPolynomial p _ n)) : f = g := by
ext1 n
apply MvPolynomial.map_injective (Int.castRingHom ℚ) Int.cast_injective
rw [← Function.funext_iff] at h
replace h :=
congr_arg (fun fam => bind₁ (MvPolynomial.map (Int.castRingHom ℚ) ∘ fam) (xInTermsOfW p ℚ n)) h
simpa only [Function.comp, map_bind₁, map_wittPolynomial, ← bind₁_bind₁,
bind₁_wittPolynomial_xInTermsOfW, bind₁_X_right] using h
#align witt_vector.poly_eq_of_witt_polynomial_bind_eq' WittVector.poly_eq_of_wittPolynomial_bind_eq'
theorem poly_eq_of_wittPolynomial_bind_eq [Fact p.Prime] (f g : ℕ → MvPolynomial ℕ ℤ)
(h : ∀ n, bind₁ f (wittPolynomial p _ n) = bind₁ g (wittPolynomial p _ n)) : f = g := by
ext1 n
apply MvPolynomial.map_injective (Int.castRingHom ℚ) Int.cast_injective
rw [← Function.funext_iff] at h
replace h :=
congr_arg (fun fam => bind₁ (MvPolynomial.map (Int.castRingHom ℚ) ∘ fam) (xInTermsOfW p ℚ n)) h
simpa only [Function.comp, map_bind₁, map_wittPolynomial, ← bind₁_bind₁,
bind₁_wittPolynomial_xInTermsOfW, bind₁_X_right] using h
#align witt_vector.poly_eq_of_witt_polynomial_bind_eq WittVector.poly_eq_of_wittPolynomial_bind_eq
-- Ideally, we would generalise this to n-ary functions
-- But we don't have a good theory of n-ary compositions in mathlib
class IsPoly (f : ∀ ⦃R⦄ [CommRing R], WittVector p R → 𝕎 R) : Prop where mk' ::
poly :
∃ φ : ℕ → MvPolynomial ℕ ℤ,
∀ ⦃R⦄ [CommRing R] (x : 𝕎 R), (f x).coeff = fun n => aeval x.coeff (φ n)
#align witt_vector.is_poly WittVector.IsPoly
instance idIsPoly : IsPoly p fun _ _ => id :=
⟨⟨X, by intros; simp only [aeval_X, id]⟩⟩
#align witt_vector.id_is_poly WittVector.idIsPoly
instance idIsPolyI' : IsPoly p fun _ _ a => a :=
WittVector.idIsPoly _
#align witt_vector.id_is_poly_i' WittVector.idIsPolyI'
namespace IsPoly
instance : Inhabited (IsPoly p fun _ _ => id) :=
⟨WittVector.idIsPoly p⟩
variable {p}
| Mathlib/RingTheory/WittVector/IsPoly.lean | 172 | 195 | theorem ext [Fact p.Prime] {f g} (hf : IsPoly p f) (hg : IsPoly p g)
(h : ∀ (R : Type u) [_Rcr : CommRing R] (x : 𝕎 R) (n : ℕ),
ghostComponent n (f x) = ghostComponent n (g x)) :
∀ (R : Type u) [_Rcr : CommRing R] (x : 𝕎 R), f x = g x := by |
obtain ⟨φ, hf⟩ := hf
obtain ⟨ψ, hg⟩ := hg
intros
ext n
rw [hf, hg, poly_eq_of_wittPolynomial_bind_eq p φ ψ]
intro k
apply MvPolynomial.funext
intro x
simp only [hom_bind₁]
specialize h (ULift ℤ) (mk p fun i => ⟨x i⟩) k
simp only [ghostComponent_apply, aeval_eq_eval₂Hom] at h
apply (ULift.ringEquiv.symm : ℤ ≃+* _).injective
simp only [← RingEquiv.coe_toRingHom, map_eval₂Hom]
convert h using 1
all_goals
simp only [hf, hg, MvPolynomial.eval, map_eval₂Hom]
apply eval₂Hom_congr (RingHom.ext_int _ _) _ rfl
ext1
apply eval₂Hom_congr (RingHom.ext_int _ _) _ rfl
simp only [coeff_mk]; rfl
|
import Mathlib.Analysis.InnerProductSpace.Basic
import Mathlib.LinearAlgebra.SesquilinearForm
#align_import analysis.inner_product_space.orthogonal from "leanprover-community/mathlib"@"f0c8bf9245297a541f468be517f1bde6195105e9"
variable {𝕜 E F : Type*} [RCLike 𝕜]
variable [NormedAddCommGroup E] [InnerProductSpace 𝕜 E]
variable [NormedAddCommGroup F] [InnerProductSpace 𝕜 F]
local notation "⟪" x ", " y "⟫" => @inner 𝕜 _ _ x y
namespace Submodule
variable (K : Submodule 𝕜 E)
def orthogonal : Submodule 𝕜 E where
carrier := { v | ∀ u ∈ K, ⟪u, v⟫ = 0 }
zero_mem' _ _ := inner_zero_right _
add_mem' hx hy u hu := by rw [inner_add_right, hx u hu, hy u hu, add_zero]
smul_mem' c x hx u hu := by rw [inner_smul_right, hx u hu, mul_zero]
#align submodule.orthogonal Submodule.orthogonal
@[inherit_doc]
notation:1200 K "ᗮ" => orthogonal K
theorem mem_orthogonal (v : E) : v ∈ Kᗮ ↔ ∀ u ∈ K, ⟪u, v⟫ = 0 :=
Iff.rfl
#align submodule.mem_orthogonal Submodule.mem_orthogonal
theorem mem_orthogonal' (v : E) : v ∈ Kᗮ ↔ ∀ u ∈ K, ⟪v, u⟫ = 0 := by
simp_rw [mem_orthogonal, inner_eq_zero_symm]
#align submodule.mem_orthogonal' Submodule.mem_orthogonal'
variable {K}
theorem inner_right_of_mem_orthogonal {u v : E} (hu : u ∈ K) (hv : v ∈ Kᗮ) : ⟪u, v⟫ = 0 :=
(K.mem_orthogonal v).1 hv u hu
#align submodule.inner_right_of_mem_orthogonal Submodule.inner_right_of_mem_orthogonal
theorem inner_left_of_mem_orthogonal {u v : E} (hu : u ∈ K) (hv : v ∈ Kᗮ) : ⟪v, u⟫ = 0 := by
rw [inner_eq_zero_symm]; exact inner_right_of_mem_orthogonal hu hv
#align submodule.inner_left_of_mem_orthogonal Submodule.inner_left_of_mem_orthogonal
theorem mem_orthogonal_singleton_iff_inner_right {u v : E} : v ∈ (𝕜 ∙ u)ᗮ ↔ ⟪u, v⟫ = 0 := by
refine ⟨inner_right_of_mem_orthogonal (mem_span_singleton_self u), ?_⟩
intro hv w hw
rw [mem_span_singleton] at hw
obtain ⟨c, rfl⟩ := hw
simp [inner_smul_left, hv]
#align submodule.mem_orthogonal_singleton_iff_inner_right Submodule.mem_orthogonal_singleton_iff_inner_right
theorem mem_orthogonal_singleton_iff_inner_left {u v : E} : v ∈ (𝕜 ∙ u)ᗮ ↔ ⟪v, u⟫ = 0 := by
rw [mem_orthogonal_singleton_iff_inner_right, inner_eq_zero_symm]
#align submodule.mem_orthogonal_singleton_iff_inner_left Submodule.mem_orthogonal_singleton_iff_inner_left
| Mathlib/Analysis/InnerProductSpace/Orthogonal.lean | 86 | 90 | theorem sub_mem_orthogonal_of_inner_left {x y : E} (h : ∀ v : K, ⟪x, v⟫ = ⟪y, v⟫) : x - y ∈ Kᗮ := by |
rw [mem_orthogonal']
intro u hu
rw [inner_sub_left, sub_eq_zero]
exact h ⟨u, hu⟩
|
import Mathlib.Algebra.Order.BigOperators.Group.Finset
import Mathlib.Combinatorics.Hall.Basic
import Mathlib.Data.Fintype.BigOperators
import Mathlib.SetTheory.Cardinal.Finite
#align_import combinatorics.configuration from "leanprover-community/mathlib"@"d2d8742b0c21426362a9dacebc6005db895ca963"
open Finset
namespace Configuration
variable (P L : Type*) [Membership P L]
def Dual :=
P
#align configuration.dual Configuration.Dual
-- Porting note: was `this` instead of `h`
instance [h : Inhabited P] : Inhabited (Dual P) :=
h
instance [Finite P] : Finite (Dual P) :=
‹Finite P›
-- Porting note: was `this` instead of `h`
instance [h : Fintype P] : Fintype (Dual P) :=
h
-- Porting note (#11215): TODO: figure out if this is needed.
set_option synthInstance.checkSynthOrder false in
instance : Membership (Dual L) (Dual P) :=
⟨Function.swap (Membership.mem : P → L → Prop)⟩
class Nondegenerate : Prop where
exists_point : ∀ l : L, ∃ p, p ∉ l
exists_line : ∀ p, ∃ l : L, p ∉ l
eq_or_eq : ∀ {p₁ p₂ : P} {l₁ l₂ : L}, p₁ ∈ l₁ → p₂ ∈ l₁ → p₁ ∈ l₂ → p₂ ∈ l₂ → p₁ = p₂ ∨ l₁ = l₂
#align configuration.nondegenerate Configuration.Nondegenerate
class HasPoints extends Nondegenerate P L where
mkPoint : ∀ {l₁ l₂ : L}, l₁ ≠ l₂ → P
mkPoint_ax : ∀ {l₁ l₂ : L} (h : l₁ ≠ l₂), mkPoint h ∈ l₁ ∧ mkPoint h ∈ l₂
#align configuration.has_points Configuration.HasPoints
class HasLines extends Nondegenerate P L where
mkLine : ∀ {p₁ p₂ : P}, p₁ ≠ p₂ → L
mkLine_ax : ∀ {p₁ p₂ : P} (h : p₁ ≠ p₂), p₁ ∈ mkLine h ∧ p₂ ∈ mkLine h
#align configuration.has_lines Configuration.HasLines
open Nondegenerate
open HasPoints (mkPoint mkPoint_ax)
open HasLines (mkLine mkLine_ax)
instance Dual.Nondegenerate [Nondegenerate P L] : Nondegenerate (Dual L) (Dual P) where
exists_point := @exists_line P L _ _
exists_line := @exists_point P L _ _
eq_or_eq := @fun l₁ l₂ p₁ p₂ h₁ h₂ h₃ h₄ => (@eq_or_eq P L _ _ p₁ p₂ l₁ l₂ h₁ h₃ h₂ h₄).symm
instance Dual.hasLines [HasPoints P L] : HasLines (Dual L) (Dual P) :=
{ Dual.Nondegenerate _ _ with
mkLine := @mkPoint P L _ _
mkLine_ax := @mkPoint_ax P L _ _ }
instance Dual.hasPoints [HasLines P L] : HasPoints (Dual L) (Dual P) :=
{ Dual.Nondegenerate _ _ with
mkPoint := @mkLine P L _ _
mkPoint_ax := @mkLine_ax P L _ _ }
theorem HasPoints.existsUnique_point [HasPoints P L] (l₁ l₂ : L) (hl : l₁ ≠ l₂) :
∃! p, p ∈ l₁ ∧ p ∈ l₂ :=
⟨mkPoint hl, mkPoint_ax hl, fun _ hp =>
(eq_or_eq hp.1 (mkPoint_ax hl).1 hp.2 (mkPoint_ax hl).2).resolve_right hl⟩
#align configuration.has_points.exists_unique_point Configuration.HasPoints.existsUnique_point
theorem HasLines.existsUnique_line [HasLines P L] (p₁ p₂ : P) (hp : p₁ ≠ p₂) :
∃! l : L, p₁ ∈ l ∧ p₂ ∈ l :=
HasPoints.existsUnique_point (Dual L) (Dual P) p₁ p₂ hp
#align configuration.has_lines.exists_unique_line Configuration.HasLines.existsUnique_line
variable {P L}
theorem Nondegenerate.exists_injective_of_card_le [Nondegenerate P L] [Fintype P] [Fintype L]
(h : Fintype.card L ≤ Fintype.card P) : ∃ f : L → P, Function.Injective f ∧ ∀ l, f l ∉ l := by
classical
let t : L → Finset P := fun l => Set.toFinset { p | p ∉ l }
suffices ∀ s : Finset L, s.card ≤ (s.biUnion t).card by
-- Hall's marriage theorem
obtain ⟨f, hf1, hf2⟩ := (Finset.all_card_le_biUnion_card_iff_exists_injective t).mp this
exact ⟨f, hf1, fun l => Set.mem_toFinset.mp (hf2 l)⟩
intro s
by_cases hs₀ : s.card = 0
-- If `s = ∅`, then `s.card = 0 ≤ (s.bUnion t).card`
· simp_rw [hs₀, zero_le]
by_cases hs₁ : s.card = 1
-- If `s = {l}`, then pick a point `p ∉ l`
· obtain ⟨l, rfl⟩ := Finset.card_eq_one.mp hs₁
obtain ⟨p, hl⟩ := exists_point l
rw [Finset.card_singleton, Finset.singleton_biUnion, Nat.one_le_iff_ne_zero]
exact Finset.card_ne_zero_of_mem (Set.mem_toFinset.mpr hl)
suffices (s.biUnion t)ᶜ.card ≤ sᶜ.card by
-- Rephrase in terms of complements (uses `h`)
rw [Finset.card_compl, Finset.card_compl, tsub_le_iff_left] at this
replace := h.trans this
rwa [← add_tsub_assoc_of_le s.card_le_univ, le_tsub_iff_left (le_add_left s.card_le_univ),
add_le_add_iff_right] at this
have hs₂ : (s.biUnion t)ᶜ.card ≤ 1 := by
-- At most one line through two points of `s`
refine Finset.card_le_one_iff.mpr @fun p₁ p₂ hp₁ hp₂ => ?_
simp_rw [t, Finset.mem_compl, Finset.mem_biUnion, not_exists, not_and,
Set.mem_toFinset, Set.mem_setOf_eq, Classical.not_not] at hp₁ hp₂
obtain ⟨l₁, l₂, hl₁, hl₂, hl₃⟩ :=
Finset.one_lt_card_iff.mp (Nat.one_lt_iff_ne_zero_and_ne_one.mpr ⟨hs₀, hs₁⟩)
exact (eq_or_eq (hp₁ l₁ hl₁) (hp₂ l₁ hl₁) (hp₁ l₂ hl₂) (hp₂ l₂ hl₂)).resolve_right hl₃
by_cases hs₃ : sᶜ.card = 0
· rw [hs₃, Nat.le_zero]
rw [Finset.card_compl, tsub_eq_zero_iff_le, LE.le.le_iff_eq (Finset.card_le_univ _), eq_comm,
Finset.card_eq_iff_eq_univ] at hs₃ ⊢
rw [hs₃]
rw [Finset.eq_univ_iff_forall] at hs₃ ⊢
exact fun p =>
Exists.elim (exists_line p)-- If `s = univ`, then show `s.bUnion t = univ`
fun l hl => Finset.mem_biUnion.mpr ⟨l, Finset.mem_univ l, Set.mem_toFinset.mpr hl⟩
· exact hs₂.trans (Nat.one_le_iff_ne_zero.mpr hs₃)
#align configuration.nondegenerate.exists_injective_of_card_le Configuration.Nondegenerate.exists_injective_of_card_le
-- If `s < univ`, then consequence of `hs₂`
variable (L)
noncomputable def lineCount (p : P) : ℕ :=
Nat.card { l : L // p ∈ l }
#align configuration.line_count Configuration.lineCount
variable (P) {L}
noncomputable def pointCount (l : L) : ℕ :=
Nat.card { p : P // p ∈ l }
#align configuration.point_count Configuration.pointCount
variable (L)
theorem sum_lineCount_eq_sum_pointCount [Fintype P] [Fintype L] :
∑ p : P, lineCount L p = ∑ l : L, pointCount P l := by
classical
simp only [lineCount, pointCount, Nat.card_eq_fintype_card, ← Fintype.card_sigma]
apply Fintype.card_congr
calc
(Σp, { l : L // p ∈ l }) ≃ { x : P × L // x.1 ∈ x.2 } :=
(Equiv.subtypeProdEquivSigmaSubtype (· ∈ ·)).symm
_ ≃ { x : L × P // x.2 ∈ x.1 } := (Equiv.prodComm P L).subtypeEquiv fun x => Iff.rfl
_ ≃ Σl, { p // p ∈ l } := Equiv.subtypeProdEquivSigmaSubtype fun (l : L) (p : P) => p ∈ l
#align configuration.sum_line_count_eq_sum_point_count Configuration.sum_lineCount_eq_sum_pointCount
variable {P L}
| Mathlib/Combinatorics/Configuration.lean | 200 | 214 | theorem HasLines.pointCount_le_lineCount [HasLines P L] {p : P} {l : L} (h : p ∉ l)
[Finite { l : L // p ∈ l }] : pointCount P l ≤ lineCount L p := by |
by_cases hf : Infinite { p : P // p ∈ l }
· exact (le_of_eq Nat.card_eq_zero_of_infinite).trans (zero_le (lineCount L p))
haveI := fintypeOfNotInfinite hf
cases nonempty_fintype { l : L // p ∈ l }
rw [lineCount, pointCount, Nat.card_eq_fintype_card, Nat.card_eq_fintype_card]
have : ∀ p' : { p // p ∈ l }, p ≠ p' := fun p' hp' => h ((congr_arg (· ∈ l) hp').mpr p'.2)
exact
Fintype.card_le_of_injective (fun p' => ⟨mkLine (this p'), (mkLine_ax (this p')).1⟩)
fun p₁ p₂ hp =>
Subtype.ext
((eq_or_eq p₁.2 p₂.2 (mkLine_ax (this p₁)).2
((congr_arg _ (Subtype.ext_iff.mp hp)).mpr (mkLine_ax (this p₂)).2)).resolve_right
fun h' => (congr_arg (¬p ∈ ·) h').mp h (mkLine_ax (this p₁)).1)
|
import Mathlib.Analysis.Convolution
import Mathlib.Analysis.SpecialFunctions.Trigonometric.EulerSineProd
import Mathlib.Analysis.SpecialFunctions.Gamma.BohrMollerup
import Mathlib.Analysis.Analytic.IsolatedZeros
import Mathlib.Analysis.Complex.CauchyIntegral
#align_import analysis.special_functions.gamma.beta from "leanprover-community/mathlib"@"a3209ddf94136d36e5e5c624b10b2a347cc9d090"
noncomputable section
set_option linter.uppercaseLean3 false
open Filter intervalIntegral Set Real MeasureTheory
open scoped Nat Topology Real
section BetaIntegral
namespace Complex
noncomputable def betaIntegral (u v : ℂ) : ℂ :=
∫ x : ℝ in (0)..1, (x : ℂ) ^ (u - 1) * (1 - (x : ℂ)) ^ (v - 1)
#align complex.beta_integral Complex.betaIntegral
theorem betaIntegral_convergent_left {u : ℂ} (hu : 0 < re u) (v : ℂ) :
IntervalIntegrable (fun x =>
(x : ℂ) ^ (u - 1) * (1 - (x : ℂ)) ^ (v - 1) : ℝ → ℂ) volume 0 (1 / 2) := by
apply IntervalIntegrable.mul_continuousOn
· refine intervalIntegral.intervalIntegrable_cpow' ?_
rwa [sub_re, one_re, ← zero_sub, sub_lt_sub_iff_right]
· apply ContinuousAt.continuousOn
intro x hx
rw [uIcc_of_le (by positivity : (0 : ℝ) ≤ 1 / 2)] at hx
apply ContinuousAt.cpow
· exact (continuous_const.sub continuous_ofReal).continuousAt
· exact continuousAt_const
· norm_cast
exact ofReal_mem_slitPlane.2 <| by linarith only [hx.2]
#align complex.beta_integral_convergent_left Complex.betaIntegral_convergent_left
theorem betaIntegral_convergent {u v : ℂ} (hu : 0 < re u) (hv : 0 < re v) :
IntervalIntegrable (fun x =>
(x : ℂ) ^ (u - 1) * (1 - (x : ℂ)) ^ (v - 1) : ℝ → ℂ) volume 0 1 := by
refine (betaIntegral_convergent_left hu v).trans ?_
rw [IntervalIntegrable.iff_comp_neg]
convert ((betaIntegral_convergent_left hv u).comp_add_right 1).symm using 1
· ext1 x
conv_lhs => rw [mul_comm]
congr 2 <;> · push_cast; ring
· norm_num
· norm_num
#align complex.beta_integral_convergent Complex.betaIntegral_convergent
theorem betaIntegral_symm (u v : ℂ) : betaIntegral v u = betaIntegral u v := by
rw [betaIntegral, betaIntegral]
have := intervalIntegral.integral_comp_mul_add (a := 0) (b := 1) (c := -1)
(fun x : ℝ => (x : ℂ) ^ (u - 1) * (1 - (x : ℂ)) ^ (v - 1)) neg_one_lt_zero.ne 1
rw [inv_neg, inv_one, neg_one_smul, ← intervalIntegral.integral_symm] at this
simp? at this says
simp only [neg_mul, one_mul, ofReal_add, ofReal_neg, ofReal_one, sub_add_cancel_right, neg_neg,
mul_one, add_left_neg, mul_zero, zero_add] at this
conv_lhs at this => arg 1; intro x; rw [add_comm, ← sub_eq_add_neg, mul_comm]
exact this
#align complex.beta_integral_symm Complex.betaIntegral_symm
theorem betaIntegral_eval_one_right {u : ℂ} (hu : 0 < re u) : betaIntegral u 1 = 1 / u := by
simp_rw [betaIntegral, sub_self, cpow_zero, mul_one]
rw [integral_cpow (Or.inl _)]
· rw [ofReal_zero, ofReal_one, one_cpow, zero_cpow, sub_zero, sub_add_cancel]
rw [sub_add_cancel]
contrapose! hu; rw [hu, zero_re]
· rwa [sub_re, one_re, ← sub_pos, sub_neg_eq_add, sub_add_cancel]
#align complex.beta_integral_eval_one_right Complex.betaIntegral_eval_one_right
theorem betaIntegral_scaled (s t : ℂ) {a : ℝ} (ha : 0 < a) :
∫ x in (0)..a, (x : ℂ) ^ (s - 1) * ((a : ℂ) - x) ^ (t - 1) =
(a : ℂ) ^ (s + t - 1) * betaIntegral s t := by
have ha' : (a : ℂ) ≠ 0 := ofReal_ne_zero.mpr ha.ne'
rw [betaIntegral]
have A : (a : ℂ) ^ (s + t - 1) = a * ((a : ℂ) ^ (s - 1) * (a : ℂ) ^ (t - 1)) := by
rw [(by abel : s + t - 1 = 1 + (s - 1) + (t - 1)), cpow_add _ _ ha', cpow_add 1 _ ha', cpow_one,
mul_assoc]
rw [A, mul_assoc, ← intervalIntegral.integral_const_mul, ← real_smul, ← zero_div a, ←
div_self ha.ne', ← intervalIntegral.integral_comp_div _ ha.ne', zero_div]
simp_rw [intervalIntegral.integral_of_le ha.le]
refine setIntegral_congr measurableSet_Ioc fun x hx => ?_
rw [mul_mul_mul_comm]
congr 1
· rw [← mul_cpow_ofReal_nonneg ha.le (div_pos hx.1 ha).le, ofReal_div, mul_div_cancel₀ _ ha']
· rw [(by norm_cast : (1 : ℂ) - ↑(x / a) = ↑(1 - x / a)), ←
mul_cpow_ofReal_nonneg ha.le (sub_nonneg.mpr <| (div_le_one ha).mpr hx.2)]
push_cast
rw [mul_sub, mul_one, mul_div_cancel₀ _ ha']
#align complex.beta_integral_scaled Complex.betaIntegral_scaled
theorem Gamma_mul_Gamma_eq_betaIntegral {s t : ℂ} (hs : 0 < re s) (ht : 0 < re t) :
Gamma s * Gamma t = Gamma (s + t) * betaIntegral s t := by
-- Note that we haven't proved (yet) that the Gamma function has no zeroes, so we can't formulate
-- this as a formula for the Beta function.
have conv_int := integral_posConvolution
(GammaIntegral_convergent hs) (GammaIntegral_convergent ht) (ContinuousLinearMap.mul ℝ ℂ)
simp_rw [ContinuousLinearMap.mul_apply'] at conv_int
have hst : 0 < re (s + t) := by rw [add_re]; exact add_pos hs ht
rw [Gamma_eq_integral hs, Gamma_eq_integral ht, Gamma_eq_integral hst, GammaIntegral,
GammaIntegral, GammaIntegral, ← conv_int, ← integral_mul_right (betaIntegral _ _)]
refine setIntegral_congr measurableSet_Ioi fun x hx => ?_
rw [mul_assoc, ← betaIntegral_scaled s t hx, ← intervalIntegral.integral_const_mul]
congr 1 with y : 1
push_cast
suffices Complex.exp (-x) = Complex.exp (-y) * Complex.exp (-(x - y)) by rw [this]; ring
rw [← Complex.exp_add]; congr 1; abel
#align complex.Gamma_mul_Gamma_eq_beta_integral Complex.Gamma_mul_Gamma_eq_betaIntegral
| Mathlib/Analysis/SpecialFunctions/Gamma/Beta.lean | 155 | 209 | theorem betaIntegral_recurrence {u v : ℂ} (hu : 0 < re u) (hv : 0 < re v) :
u * betaIntegral u (v + 1) = v * betaIntegral (u + 1) v := by |
-- NB: If we knew `Gamma (u + v + 1) ≠ 0` this would be an easy consequence of
-- `Gamma_mul_Gamma_eq_betaIntegral`; but we don't know that yet. We will prove it later, but
-- this lemma is needed in the proof. So we give a (somewhat laborious) direct argument.
let F : ℝ → ℂ := fun x => (x : ℂ) ^ u * (1 - (x : ℂ)) ^ v
have hu' : 0 < re (u + 1) := by rw [add_re, one_re]; positivity
have hv' : 0 < re (v + 1) := by rw [add_re, one_re]; positivity
have hc : ContinuousOn F (Icc 0 1) := by
refine (ContinuousAt.continuousOn fun x hx => ?_).mul (ContinuousAt.continuousOn fun x hx => ?_)
· refine (continuousAt_cpow_const_of_re_pos (Or.inl ?_) hu).comp continuous_ofReal.continuousAt
rw [ofReal_re]; exact hx.1
· refine (continuousAt_cpow_const_of_re_pos (Or.inl ?_) hv).comp
(continuous_const.sub continuous_ofReal).continuousAt
rw [sub_re, one_re, ofReal_re, sub_nonneg]
exact hx.2
have hder : ∀ x : ℝ, x ∈ Ioo (0 : ℝ) 1 →
HasDerivAt F (u * ((x : ℂ) ^ (u - 1) * (1 - (x : ℂ)) ^ v) -
v * ((x : ℂ) ^ u * (1 - (x : ℂ)) ^ (v - 1))) x := by
intro x hx
have U : HasDerivAt (fun y : ℂ => y ^ u) (u * (x : ℂ) ^ (u - 1)) ↑x := by
have := @HasDerivAt.cpow_const _ _ _ u (hasDerivAt_id (x : ℂ)) (Or.inl ?_)
· simp only [id_eq, mul_one] at this
exact this
· rw [id_eq, ofReal_re]; exact hx.1
have V : HasDerivAt (fun y : ℂ => (1 - y) ^ v) (-v * (1 - (x : ℂ)) ^ (v - 1)) ↑x := by
have A := @HasDerivAt.cpow_const _ _ _ v (hasDerivAt_id (1 - (x : ℂ))) (Or.inl ?_)
swap; · rw [id, sub_re, one_re, ofReal_re, sub_pos]; exact hx.2
simp_rw [id] at A
have B : HasDerivAt (fun y : ℂ => 1 - y) (-1) ↑x := by
apply HasDerivAt.const_sub; apply hasDerivAt_id
convert HasDerivAt.comp (↑x) A B using 1
ring
convert (U.mul V).comp_ofReal using 1
ring
have h_int := ((betaIntegral_convergent hu hv').const_mul u).sub
((betaIntegral_convergent hu' hv).const_mul v)
rw [add_sub_cancel_right, add_sub_cancel_right] at h_int
have int_ev := intervalIntegral.integral_eq_sub_of_hasDerivAt_of_le zero_le_one hc hder h_int
have hF0 : F 0 = 0 := by
simp only [F, mul_eq_zero, ofReal_zero, cpow_eq_zero_iff, eq_self_iff_true, Ne,
true_and_iff, sub_zero, one_cpow, one_ne_zero, or_false_iff]
contrapose! hu; rw [hu, zero_re]
have hF1 : F 1 = 0 := by
simp only [F, mul_eq_zero, ofReal_one, one_cpow, one_ne_zero, sub_self, cpow_eq_zero_iff,
eq_self_iff_true, Ne, true_and_iff, false_or_iff]
contrapose! hv; rw [hv, zero_re]
rw [hF0, hF1, sub_zero, intervalIntegral.integral_sub, intervalIntegral.integral_const_mul,
intervalIntegral.integral_const_mul] at int_ev
· rw [betaIntegral, betaIntegral, ← sub_eq_zero]
convert int_ev <;> ring
· apply IntervalIntegrable.const_mul
convert betaIntegral_convergent hu hv'; ring
· apply IntervalIntegrable.const_mul
convert betaIntegral_convergent hu' hv; ring
|
import Mathlib.Algebra.Field.Basic
import Mathlib.Deprecated.Subring
#align_import deprecated.subfield from "leanprover-community/mathlib"@"bd9851ca476957ea4549eb19b40e7b5ade9428cc"
variable {F : Type*} [Field F] (S : Set F)
structure IsSubfield extends IsSubring S : Prop where
inv_mem : ∀ {x : F}, x ∈ S → x⁻¹ ∈ S
#align is_subfield IsSubfield
theorem IsSubfield.div_mem {S : Set F} (hS : IsSubfield S) {x y : F} (hx : x ∈ S) (hy : y ∈ S) :
x / y ∈ S := by
rw [div_eq_mul_inv]
exact hS.toIsSubring.toIsSubmonoid.mul_mem hx (hS.inv_mem hy)
#align is_subfield.div_mem IsSubfield.div_mem
theorem IsSubfield.pow_mem {a : F} {n : ℤ} {s : Set F} (hs : IsSubfield s) (h : a ∈ s) :
a ^ n ∈ s := by
cases' n with n n
· suffices a ^ (n : ℤ) ∈ s by exact this
rw [zpow_natCast]
exact hs.toIsSubring.toIsSubmonoid.pow_mem h
· rw [zpow_negSucc]
exact hs.inv_mem (hs.toIsSubring.toIsSubmonoid.pow_mem h)
#align is_subfield.pow_mem IsSubfield.pow_mem
theorem Univ.isSubfield : IsSubfield (@Set.univ F) :=
{ Univ.isSubmonoid, IsAddSubgroup.univ_addSubgroup with
inv_mem := fun _ ↦ trivial }
#align univ.is_subfield Univ.isSubfield
theorem Preimage.isSubfield {K : Type*} [Field K] (f : F →+* K) {s : Set K} (hs : IsSubfield s) :
IsSubfield (f ⁻¹' s) :=
{ f.isSubring_preimage hs.toIsSubring with
inv_mem := fun {a} (ha : f a ∈ s) ↦ show f a⁻¹ ∈ s by
rw [map_inv₀]
exact hs.inv_mem ha }
#align preimage.is_subfield Preimage.isSubfield
theorem Image.isSubfield {K : Type*} [Field K] (f : F →+* K) {s : Set F} (hs : IsSubfield s) :
IsSubfield (f '' s) :=
{ f.isSubring_image hs.toIsSubring with
inv_mem := fun ⟨x, xmem, ha⟩ ↦ ⟨x⁻¹, hs.inv_mem xmem, ha ▸ map_inv₀ f x⟩ }
#align image.is_subfield Image.isSubfield
| Mathlib/Deprecated/Subfield.lean | 75 | 77 | theorem Range.isSubfield {K : Type*} [Field K] (f : F →+* K) : IsSubfield (Set.range f) := by |
rw [← Set.image_univ]
apply Image.isSubfield _ Univ.isSubfield
|
import Mathlib.Algebra.Polynomial.Degree.Definitions
import Mathlib.Data.ENat.Basic
#align_import data.polynomial.degree.trailing_degree from "leanprover-community/mathlib"@"302eab4f46abb63de520828de78c04cb0f9b5836"
noncomputable section
open Function Polynomial Finsupp Finset
open scoped Polynomial
namespace Polynomial
universe u v
variable {R : Type u} {S : Type v} {a b : R} {n m : ℕ}
section Semiring
variable [Semiring R] {p q r : R[X]}
def trailingDegree (p : R[X]) : ℕ∞ :=
p.support.min
#align polynomial.trailing_degree Polynomial.trailingDegree
theorem trailingDegree_lt_wf : WellFounded fun p q : R[X] => trailingDegree p < trailingDegree q :=
InvImage.wf trailingDegree wellFounded_lt
#align polynomial.trailing_degree_lt_wf Polynomial.trailingDegree_lt_wf
def natTrailingDegree (p : R[X]) : ℕ :=
(trailingDegree p).getD 0
#align polynomial.nat_trailing_degree Polynomial.natTrailingDegree
def trailingCoeff (p : R[X]) : R :=
coeff p (natTrailingDegree p)
#align polynomial.trailing_coeff Polynomial.trailingCoeff
def TrailingMonic (p : R[X]) :=
trailingCoeff p = (1 : R)
#align polynomial.trailing_monic Polynomial.TrailingMonic
theorem TrailingMonic.def : TrailingMonic p ↔ trailingCoeff p = 1 :=
Iff.rfl
#align polynomial.trailing_monic.def Polynomial.TrailingMonic.def
instance TrailingMonic.decidable [DecidableEq R] : Decidable (TrailingMonic p) :=
inferInstanceAs <| Decidable (trailingCoeff p = (1 : R))
#align polynomial.trailing_monic.decidable Polynomial.TrailingMonic.decidable
@[simp]
theorem TrailingMonic.trailingCoeff {p : R[X]} (hp : p.TrailingMonic) : trailingCoeff p = 1 :=
hp
#align polynomial.trailing_monic.trailing_coeff Polynomial.TrailingMonic.trailingCoeff
@[simp]
theorem trailingDegree_zero : trailingDegree (0 : R[X]) = ⊤ :=
rfl
#align polynomial.trailing_degree_zero Polynomial.trailingDegree_zero
@[simp]
theorem trailingCoeff_zero : trailingCoeff (0 : R[X]) = 0 :=
rfl
#align polynomial.trailing_coeff_zero Polynomial.trailingCoeff_zero
@[simp]
theorem natTrailingDegree_zero : natTrailingDegree (0 : R[X]) = 0 :=
rfl
#align polynomial.nat_trailing_degree_zero Polynomial.natTrailingDegree_zero
theorem trailingDegree_eq_top : trailingDegree p = ⊤ ↔ p = 0 :=
⟨fun h => support_eq_empty.1 (Finset.min_eq_top.1 h), fun h => by simp [h]⟩
#align polynomial.trailing_degree_eq_top Polynomial.trailingDegree_eq_top
theorem trailingDegree_eq_natTrailingDegree (hp : p ≠ 0) :
trailingDegree p = (natTrailingDegree p : ℕ∞) := by
let ⟨n, hn⟩ :=
not_forall.1 (mt Option.eq_none_iff_forall_not_mem.2 (mt trailingDegree_eq_top.1 hp))
have hn : trailingDegree p = n := Classical.not_not.1 hn
rw [natTrailingDegree, hn]
rfl
#align polynomial.trailing_degree_eq_nat_trailing_degree Polynomial.trailingDegree_eq_natTrailingDegree
theorem trailingDegree_eq_iff_natTrailingDegree_eq {p : R[X]} {n : ℕ} (hp : p ≠ 0) :
p.trailingDegree = n ↔ p.natTrailingDegree = n := by
rw [trailingDegree_eq_natTrailingDegree hp]
exact WithTop.coe_eq_coe
#align polynomial.trailing_degree_eq_iff_nat_trailing_degree_eq Polynomial.trailingDegree_eq_iff_natTrailingDegree_eq
theorem trailingDegree_eq_iff_natTrailingDegree_eq_of_pos {p : R[X]} {n : ℕ} (hn : 0 < n) :
p.trailingDegree = n ↔ p.natTrailingDegree = n := by
constructor
· intro H
rwa [← trailingDegree_eq_iff_natTrailingDegree_eq]
rintro rfl
rw [trailingDegree_zero] at H
exact Option.noConfusion H
· intro H
rwa [trailingDegree_eq_iff_natTrailingDegree_eq]
rintro rfl
rw [natTrailingDegree_zero] at H
rw [H] at hn
exact lt_irrefl _ hn
#align polynomial.trailing_degree_eq_iff_nat_trailing_degree_eq_of_pos Polynomial.trailingDegree_eq_iff_natTrailingDegree_eq_of_pos
theorem natTrailingDegree_eq_of_trailingDegree_eq_some {p : R[X]} {n : ℕ}
(h : trailingDegree p = n) : natTrailingDegree p = n :=
have hp0 : p ≠ 0 := fun hp0 => by rw [hp0] at h; exact Option.noConfusion h
Option.some_inj.1 <|
show (natTrailingDegree p : ℕ∞) = n by rwa [← trailingDegree_eq_natTrailingDegree hp0]
#align polynomial.nat_trailing_degree_eq_of_trailing_degree_eq_some Polynomial.natTrailingDegree_eq_of_trailingDegree_eq_some
@[simp]
| Mathlib/Algebra/Polynomial/Degree/TrailingDegree.lean | 141 | 145 | theorem natTrailingDegree_le_trailingDegree : ↑(natTrailingDegree p) ≤ trailingDegree p := by |
by_cases hp : p = 0;
· rw [hp, trailingDegree_zero]
exact le_top
rw [trailingDegree_eq_natTrailingDegree hp]
|
import Batteries.Data.Rat.Basic
import Batteries.Tactic.SeqFocus
namespace Rat
theorem ext : {p q : Rat} → p.num = q.num → p.den = q.den → p = q
| ⟨_,_,_,_⟩, ⟨_,_,_,_⟩, rfl, rfl => rfl
@[simp] theorem mk_den_one {r : Int} :
⟨r, 1, Nat.one_ne_zero, (Nat.coprime_one_right _)⟩ = (r : Rat) := rfl
@[simp] theorem zero_num : (0 : Rat).num = 0 := rfl
@[simp] theorem zero_den : (0 : Rat).den = 1 := rfl
@[simp] theorem one_num : (1 : Rat).num = 1 := rfl
@[simp] theorem one_den : (1 : Rat).den = 1 := rfl
@[simp] theorem maybeNormalize_eq {num den g} (den_nz reduced) :
maybeNormalize num den g den_nz reduced =
{ num := num.div g, den := den / g, den_nz, reduced } := by
unfold maybeNormalize; split
· subst g; simp
· rfl
theorem normalize.reduced' {num : Int} {den g : Nat} (den_nz : den ≠ 0)
(e : g = num.natAbs.gcd den) : (num / g).natAbs.Coprime (den / g) := by
rw [← Int.div_eq_ediv_of_dvd (e ▸ Int.ofNat_dvd_left.2 (Nat.gcd_dvd_left ..))]
exact normalize.reduced den_nz e
theorem normalize_eq {num den} (den_nz) : normalize num den den_nz =
{ num := num / num.natAbs.gcd den
den := den / num.natAbs.gcd den
den_nz := normalize.den_nz den_nz rfl
reduced := normalize.reduced' den_nz rfl } := by
simp only [normalize, maybeNormalize_eq,
Int.div_eq_ediv_of_dvd (Int.ofNat_dvd_left.2 (Nat.gcd_dvd_left ..))]
@[simp] theorem normalize_zero (nz) : normalize 0 d nz = 0 := by
simp [normalize, Int.zero_div, Int.natAbs_zero, Nat.div_self (Nat.pos_of_ne_zero nz)]; rfl
theorem mk_eq_normalize (num den nz c) : ⟨num, den, nz, c⟩ = normalize num den nz := by
simp [normalize_eq, c.gcd_eq_one]
theorem normalize_self (r : Rat) : normalize r.num r.den r.den_nz = r := (mk_eq_normalize ..).symm
theorem normalize_mul_left {a : Nat} (d0 : d ≠ 0) (a0 : a ≠ 0) :
normalize (↑a * n) (a * d) (Nat.mul_ne_zero a0 d0) = normalize n d d0 := by
simp [normalize_eq, mk'.injEq, Int.natAbs_mul, Nat.gcd_mul_left,
Nat.mul_div_mul_left _ _ (Nat.pos_of_ne_zero a0), Int.ofNat_mul,
Int.mul_ediv_mul_of_pos _ _ (Int.ofNat_pos.2 <| Nat.pos_of_ne_zero a0)]
theorem normalize_mul_right {a : Nat} (d0 : d ≠ 0) (a0 : a ≠ 0) :
normalize (n * a) (d * a) (Nat.mul_ne_zero d0 a0) = normalize n d d0 := by
rw [← normalize_mul_left (d0 := d0) a0]; congr 1 <;> [apply Int.mul_comm; apply Nat.mul_comm]
theorem normalize_eq_iff (z₁ : d₁ ≠ 0) (z₂ : d₂ ≠ 0) :
normalize n₁ d₁ z₁ = normalize n₂ d₂ z₂ ↔ n₁ * d₂ = n₂ * d₁ := by
constructor <;> intro h
· simp only [normalize_eq, mk'.injEq] at h
have' hn₁ := Int.ofNat_dvd_left.2 <| Nat.gcd_dvd_left n₁.natAbs d₁
have' hn₂ := Int.ofNat_dvd_left.2 <| Nat.gcd_dvd_left n₂.natAbs d₂
have' hd₁ := Int.ofNat_dvd.2 <| Nat.gcd_dvd_right n₁.natAbs d₁
have' hd₂ := Int.ofNat_dvd.2 <| Nat.gcd_dvd_right n₂.natAbs d₂
rw [← Int.ediv_mul_cancel (Int.dvd_trans hd₂ (Int.dvd_mul_left ..)),
Int.mul_ediv_assoc _ hd₂, ← Int.ofNat_ediv, ← h.2, Int.ofNat_ediv,
← Int.mul_ediv_assoc _ hd₁, Int.mul_ediv_assoc' _ hn₁,
Int.mul_right_comm, h.1, Int.ediv_mul_cancel hn₂]
· rw [← normalize_mul_right _ z₂, ← normalize_mul_left z₂ z₁, Int.mul_comm d₁, h]
theorem maybeNormalize_eq_normalize {num : Int} {den g : Nat} (den_nz reduced)
(hn : ↑g ∣ num) (hd : g ∣ den) :
maybeNormalize num den g den_nz reduced = normalize num den (mt (by simp [·]) den_nz) := by
simp only [maybeNormalize_eq, mk_eq_normalize, Int.div_eq_ediv_of_dvd hn]
have : g ≠ 0 := mt (by simp [·]) den_nz
rw [← normalize_mul_right _ this, Int.ediv_mul_cancel hn]
congr 1; exact Nat.div_mul_cancel hd
@[simp] theorem normalize_eq_zero (d0 : d ≠ 0) : normalize n d d0 = 0 ↔ n = 0 := by
have' := normalize_eq_iff d0 Nat.one_ne_zero
rw [normalize_zero (d := 1)] at this; rw [this]; simp
theorem normalize_num_den' (num den nz) : ∃ d : Nat, d ≠ 0 ∧
num = (normalize num den nz).num * d ∧ den = (normalize num den nz).den * d := by
refine ⟨num.natAbs.gcd den, Nat.gcd_ne_zero_right nz, ?_⟩
simp [normalize_eq, Int.ediv_mul_cancel (Int.ofNat_dvd_left.2 <| Nat.gcd_dvd_left ..),
Nat.div_mul_cancel (Nat.gcd_dvd_right ..)]
theorem normalize_num_den (h : normalize n d z = ⟨n', d', z', c⟩) :
∃ m : Nat, m ≠ 0 ∧ n = n' * m ∧ d = d' * m := by
have := normalize_num_den' n d z; rwa [h] at this
theorem normalize_eq_mkRat {num den} (den_nz) : normalize num den den_nz = mkRat num den := by
simp [mkRat, den_nz]
theorem mkRat_num_den (z : d ≠ 0) (h : mkRat n d = ⟨n', d', z', c⟩) :
∃ m : Nat, m ≠ 0 ∧ n = n' * m ∧ d = d' * m :=
normalize_num_den ((normalize_eq_mkRat z).symm ▸ h)
theorem mkRat_def (n d) : mkRat n d = if d0 : d = 0 then 0 else normalize n d d0 := rfl
| .lake/packages/batteries/Batteries/Data/Rat/Lemmas.lean | 107 | 108 | theorem mkRat_self (a : Rat) : mkRat a.num a.den = a := by |
rw [← normalize_eq_mkRat a.den_nz, normalize_self]
|
import Mathlib.Algebra.BigOperators.Option
import Mathlib.Analysis.BoxIntegral.Box.Basic
import Mathlib.Data.Set.Pairwise.Lattice
#align_import analysis.box_integral.partition.basic from "leanprover-community/mathlib"@"84dc0bd6619acaea625086d6f53cb35cdd554219"
open Set Finset Function
open scoped Classical
open NNReal
noncomputable section
namespace BoxIntegral
variable {ι : Type*}
structure Prepartition (I : Box ι) where
boxes : Finset (Box ι)
le_of_mem' : ∀ J ∈ boxes, J ≤ I
pairwiseDisjoint : Set.Pairwise (↑boxes) (Disjoint on ((↑) : Box ι → Set (ι → ℝ)))
#align box_integral.prepartition BoxIntegral.Prepartition
namespace Prepartition
variable {I J J₁ J₂ : Box ι} (π : Prepartition I) {π₁ π₂ : Prepartition I} {x : ι → ℝ}
instance : Membership (Box ι) (Prepartition I) :=
⟨fun J π => J ∈ π.boxes⟩
@[simp]
theorem mem_boxes : J ∈ π.boxes ↔ J ∈ π := Iff.rfl
#align box_integral.prepartition.mem_boxes BoxIntegral.Prepartition.mem_boxes
@[simp]
theorem mem_mk {s h₁ h₂} : J ∈ (mk s h₁ h₂ : Prepartition I) ↔ J ∈ s := Iff.rfl
#align box_integral.prepartition.mem_mk BoxIntegral.Prepartition.mem_mk
theorem disjoint_coe_of_mem (h₁ : J₁ ∈ π) (h₂ : J₂ ∈ π) (h : J₁ ≠ J₂) :
Disjoint (J₁ : Set (ι → ℝ)) J₂ :=
π.pairwiseDisjoint h₁ h₂ h
#align box_integral.prepartition.disjoint_coe_of_mem BoxIntegral.Prepartition.disjoint_coe_of_mem
theorem eq_of_mem_of_mem (h₁ : J₁ ∈ π) (h₂ : J₂ ∈ π) (hx₁ : x ∈ J₁) (hx₂ : x ∈ J₂) : J₁ = J₂ :=
by_contra fun H => (π.disjoint_coe_of_mem h₁ h₂ H).le_bot ⟨hx₁, hx₂⟩
#align box_integral.prepartition.eq_of_mem_of_mem BoxIntegral.Prepartition.eq_of_mem_of_mem
theorem eq_of_le_of_le (h₁ : J₁ ∈ π) (h₂ : J₂ ∈ π) (hle₁ : J ≤ J₁) (hle₂ : J ≤ J₂) : J₁ = J₂ :=
π.eq_of_mem_of_mem h₁ h₂ (hle₁ J.upper_mem) (hle₂ J.upper_mem)
#align box_integral.prepartition.eq_of_le_of_le BoxIntegral.Prepartition.eq_of_le_of_le
theorem eq_of_le (h₁ : J₁ ∈ π) (h₂ : J₂ ∈ π) (hle : J₁ ≤ J₂) : J₁ = J₂ :=
π.eq_of_le_of_le h₁ h₂ le_rfl hle
#align box_integral.prepartition.eq_of_le BoxIntegral.Prepartition.eq_of_le
theorem le_of_mem (hJ : J ∈ π) : J ≤ I :=
π.le_of_mem' J hJ
#align box_integral.prepartition.le_of_mem BoxIntegral.Prepartition.le_of_mem
theorem lower_le_lower (hJ : J ∈ π) : I.lower ≤ J.lower :=
Box.antitone_lower (π.le_of_mem hJ)
#align box_integral.prepartition.lower_le_lower BoxIntegral.Prepartition.lower_le_lower
theorem upper_le_upper (hJ : J ∈ π) : J.upper ≤ I.upper :=
Box.monotone_upper (π.le_of_mem hJ)
#align box_integral.prepartition.upper_le_upper BoxIntegral.Prepartition.upper_le_upper
theorem injective_boxes : Function.Injective (boxes : Prepartition I → Finset (Box ι)) := by
rintro ⟨s₁, h₁, h₁'⟩ ⟨s₂, h₂, h₂'⟩ (rfl : s₁ = s₂)
rfl
#align box_integral.prepartition.injective_boxes BoxIntegral.Prepartition.injective_boxes
@[ext]
theorem ext (h : ∀ J, J ∈ π₁ ↔ J ∈ π₂) : π₁ = π₂ :=
injective_boxes <| Finset.ext h
#align box_integral.prepartition.ext BoxIntegral.Prepartition.ext
@[simps]
def single (I J : Box ι) (h : J ≤ I) : Prepartition I :=
⟨{J}, by simpa, by simp⟩
#align box_integral.prepartition.single BoxIntegral.Prepartition.single
@[simp]
theorem mem_single {J'} (h : J ≤ I) : J' ∈ single I J h ↔ J' = J :=
mem_singleton
#align box_integral.prepartition.mem_single BoxIntegral.Prepartition.mem_single
instance : LE (Prepartition I) :=
⟨fun π π' => ∀ ⦃I⦄, I ∈ π → ∃ I' ∈ π', I ≤ I'⟩
instance partialOrder : PartialOrder (Prepartition I) where
le := (· ≤ ·)
le_refl π I hI := ⟨I, hI, le_rfl⟩
le_trans π₁ π₂ π₃ h₁₂ h₂₃ I₁ hI₁ :=
let ⟨I₂, hI₂, hI₁₂⟩ := h₁₂ hI₁
let ⟨I₃, hI₃, hI₂₃⟩ := h₂₃ hI₂
⟨I₃, hI₃, hI₁₂.trans hI₂₃⟩
le_antisymm := by
suffices ∀ {π₁ π₂ : Prepartition I}, π₁ ≤ π₂ → π₂ ≤ π₁ → π₁.boxes ⊆ π₂.boxes from
fun π₁ π₂ h₁ h₂ => injective_boxes (Subset.antisymm (this h₁ h₂) (this h₂ h₁))
intro π₁ π₂ h₁ h₂ J hJ
rcases h₁ hJ with ⟨J', hJ', hle⟩; rcases h₂ hJ' with ⟨J'', hJ'', hle'⟩
obtain rfl : J = J'' := π₁.eq_of_le hJ hJ'' (hle.trans hle')
obtain rfl : J' = J := le_antisymm ‹_› ‹_›
assumption
instance : OrderTop (Prepartition I) where
top := single I I le_rfl
le_top π J hJ := ⟨I, by simp, π.le_of_mem hJ⟩
instance : OrderBot (Prepartition I) where
bot := ⟨∅,
fun _ hJ => (Finset.not_mem_empty _ hJ).elim,
fun _ hJ => (Set.not_mem_empty _ <| Finset.coe_empty ▸ hJ).elim⟩
bot_le _ _ hJ := (Finset.not_mem_empty _ hJ).elim
instance : Inhabited (Prepartition I) := ⟨⊤⟩
theorem le_def : π₁ ≤ π₂ ↔ ∀ J ∈ π₁, ∃ J' ∈ π₂, J ≤ J' := Iff.rfl
#align box_integral.prepartition.le_def BoxIntegral.Prepartition.le_def
@[simp]
theorem mem_top : J ∈ (⊤ : Prepartition I) ↔ J = I :=
mem_singleton
#align box_integral.prepartition.mem_top BoxIntegral.Prepartition.mem_top
@[simp]
theorem top_boxes : (⊤ : Prepartition I).boxes = {I} := rfl
#align box_integral.prepartition.top_boxes BoxIntegral.Prepartition.top_boxes
@[simp]
theorem not_mem_bot : J ∉ (⊥ : Prepartition I) :=
Finset.not_mem_empty _
#align box_integral.prepartition.not_mem_bot BoxIntegral.Prepartition.not_mem_bot
@[simp]
theorem bot_boxes : (⊥ : Prepartition I).boxes = ∅ := rfl
#align box_integral.prepartition.bot_boxes BoxIntegral.Prepartition.bot_boxes
theorem injOn_setOf_mem_Icc_setOf_lower_eq (x : ι → ℝ) :
InjOn (fun J : Box ι => { i | J.lower i = x i }) { J | J ∈ π ∧ x ∈ Box.Icc J } := by
rintro J₁ ⟨h₁, hx₁⟩ J₂ ⟨h₂, hx₂⟩ (H : { i | J₁.lower i = x i } = { i | J₂.lower i = x i })
suffices ∀ i, (Ioc (J₁.lower i) (J₁.upper i) ∩ Ioc (J₂.lower i) (J₂.upper i)).Nonempty by
choose y hy₁ hy₂ using this
exact π.eq_of_mem_of_mem h₁ h₂ hy₁ hy₂
intro i
simp only [Set.ext_iff, mem_setOf] at H
rcases (hx₁.1 i).eq_or_lt with hi₁ | hi₁
· have hi₂ : J₂.lower i = x i := (H _).1 hi₁
have H₁ : x i < J₁.upper i := by simpa only [hi₁] using J₁.lower_lt_upper i
have H₂ : x i < J₂.upper i := by simpa only [hi₂] using J₂.lower_lt_upper i
rw [Ioc_inter_Ioc, hi₁, hi₂, sup_idem, Set.nonempty_Ioc]
exact lt_min H₁ H₂
· have hi₂ : J₂.lower i < x i := (hx₂.1 i).lt_of_ne (mt (H _).2 hi₁.ne)
exact ⟨x i, ⟨hi₁, hx₁.2 i⟩, ⟨hi₂, hx₂.2 i⟩⟩
#align box_integral.prepartition.inj_on_set_of_mem_Icc_set_of_lower_eq BoxIntegral.Prepartition.injOn_setOf_mem_Icc_setOf_lower_eq
theorem card_filter_mem_Icc_le [Fintype ι] (x : ι → ℝ) :
(π.boxes.filter fun J : Box ι => x ∈ Box.Icc J).card ≤ 2 ^ Fintype.card ι := by
rw [← Fintype.card_set]
refine Finset.card_le_card_of_inj_on (fun J : Box ι => { i | J.lower i = x i })
(fun _ _ => Finset.mem_univ _) ?_
simpa only [Finset.mem_filter] using π.injOn_setOf_mem_Icc_setOf_lower_eq x
#align box_integral.prepartition.card_filter_mem_Icc_le BoxIntegral.Prepartition.card_filter_mem_Icc_le
protected def iUnion : Set (ι → ℝ) :=
⋃ J ∈ π, ↑J
#align box_integral.prepartition.Union BoxIntegral.Prepartition.iUnion
theorem iUnion_def : π.iUnion = ⋃ J ∈ π, ↑J := rfl
#align box_integral.prepartition.Union_def BoxIntegral.Prepartition.iUnion_def
theorem iUnion_def' : π.iUnion = ⋃ J ∈ π.boxes, ↑J := rfl
#align box_integral.prepartition.Union_def' BoxIntegral.Prepartition.iUnion_def'
-- Porting note: Previous proof was `:= Set.mem_iUnion₂`
@[simp]
theorem mem_iUnion : x ∈ π.iUnion ↔ ∃ J ∈ π, x ∈ J := by
convert Set.mem_iUnion₂
rw [Box.mem_coe, exists_prop]
#align box_integral.prepartition.mem_Union BoxIntegral.Prepartition.mem_iUnion
@[simp]
theorem iUnion_single (h : J ≤ I) : (single I J h).iUnion = J := by simp [iUnion_def]
#align box_integral.prepartition.Union_single BoxIntegral.Prepartition.iUnion_single
@[simp]
theorem iUnion_top : (⊤ : Prepartition I).iUnion = I := by simp [Prepartition.iUnion]
#align box_integral.prepartition.Union_top BoxIntegral.Prepartition.iUnion_top
@[simp]
theorem iUnion_eq_empty : π₁.iUnion = ∅ ↔ π₁ = ⊥ := by
simp [← injective_boxes.eq_iff, Finset.ext_iff, Prepartition.iUnion, imp_false]
#align box_integral.prepartition.Union_eq_empty BoxIntegral.Prepartition.iUnion_eq_empty
@[simp]
theorem iUnion_bot : (⊥ : Prepartition I).iUnion = ∅ :=
iUnion_eq_empty.2 rfl
#align box_integral.prepartition.Union_bot BoxIntegral.Prepartition.iUnion_bot
theorem subset_iUnion (h : J ∈ π) : ↑J ⊆ π.iUnion :=
subset_biUnion_of_mem h
#align box_integral.prepartition.subset_Union BoxIntegral.Prepartition.subset_iUnion
theorem iUnion_subset : π.iUnion ⊆ I :=
iUnion₂_subset π.le_of_mem'
#align box_integral.prepartition.Union_subset BoxIntegral.Prepartition.iUnion_subset
@[mono]
theorem iUnion_mono (h : π₁ ≤ π₂) : π₁.iUnion ⊆ π₂.iUnion := fun _ hx =>
let ⟨_, hJ₁, hx⟩ := π₁.mem_iUnion.1 hx
let ⟨J₂, hJ₂, hle⟩ := h hJ₁
π₂.mem_iUnion.2 ⟨J₂, hJ₂, hle hx⟩
#align box_integral.prepartition.Union_mono BoxIntegral.Prepartition.iUnion_mono
theorem disjoint_boxes_of_disjoint_iUnion (h : Disjoint π₁.iUnion π₂.iUnion) :
Disjoint π₁.boxes π₂.boxes :=
Finset.disjoint_left.2 fun J h₁ h₂ =>
Disjoint.le_bot (h.mono (π₁.subset_iUnion h₁) (π₂.subset_iUnion h₂)) ⟨J.upper_mem, J.upper_mem⟩
#align box_integral.prepartition.disjoint_boxes_of_disjoint_Union BoxIntegral.Prepartition.disjoint_boxes_of_disjoint_iUnion
theorem le_iff_nonempty_imp_le_and_iUnion_subset :
π₁ ≤ π₂ ↔
(∀ J ∈ π₁, ∀ J' ∈ π₂, (J ∩ J' : Set (ι → ℝ)).Nonempty → J ≤ J') ∧ π₁.iUnion ⊆ π₂.iUnion := by
constructor
· refine fun H => ⟨fun J hJ J' hJ' Hne => ?_, iUnion_mono H⟩
rcases H hJ with ⟨J'', hJ'', Hle⟩
rcases Hne with ⟨x, hx, hx'⟩
rwa [π₂.eq_of_mem_of_mem hJ' hJ'' hx' (Hle hx)]
· rintro ⟨H, HU⟩ J hJ
simp only [Set.subset_def, mem_iUnion] at HU
rcases HU J.upper ⟨J, hJ, J.upper_mem⟩ with ⟨J₂, hJ₂, hx⟩
exact ⟨J₂, hJ₂, H _ hJ _ hJ₂ ⟨_, J.upper_mem, hx⟩⟩
#align box_integral.prepartition.le_iff_nonempty_imp_le_and_Union_subset BoxIntegral.Prepartition.le_iff_nonempty_imp_le_and_iUnion_subset
theorem eq_of_boxes_subset_iUnion_superset (h₁ : π₁.boxes ⊆ π₂.boxes) (h₂ : π₂.iUnion ⊆ π₁.iUnion) :
π₁ = π₂ :=
le_antisymm (fun J hJ => ⟨J, h₁ hJ, le_rfl⟩) <|
le_iff_nonempty_imp_le_and_iUnion_subset.2
⟨fun _ hJ₁ _ hJ₂ Hne =>
(π₂.eq_of_mem_of_mem hJ₁ (h₁ hJ₂) Hne.choose_spec.1 Hne.choose_spec.2).le, h₂⟩
#align box_integral.prepartition.eq_of_boxes_subset_Union_superset BoxIntegral.Prepartition.eq_of_boxes_subset_iUnion_superset
@[simps]
def biUnion (πi : ∀ J : Box ι, Prepartition J) : Prepartition I where
boxes := π.boxes.biUnion fun J => (πi J).boxes
le_of_mem' J hJ := by
simp only [Finset.mem_biUnion, exists_prop, mem_boxes] at hJ
rcases hJ with ⟨J', hJ', hJ⟩
exact ((πi J').le_of_mem hJ).trans (π.le_of_mem hJ')
pairwiseDisjoint := by
simp only [Set.Pairwise, Finset.mem_coe, Finset.mem_biUnion]
rintro J₁' ⟨J₁, hJ₁, hJ₁'⟩ J₂' ⟨J₂, hJ₂, hJ₂'⟩ Hne
rw [Function.onFun, Set.disjoint_left]
rintro x hx₁ hx₂; apply Hne
obtain rfl : J₁ = J₂ :=
π.eq_of_mem_of_mem hJ₁ hJ₂ ((πi J₁).le_of_mem hJ₁' hx₁) ((πi J₂).le_of_mem hJ₂' hx₂)
exact (πi J₁).eq_of_mem_of_mem hJ₁' hJ₂' hx₁ hx₂
#align box_integral.prepartition.bUnion BoxIntegral.Prepartition.biUnion
variable {πi πi₁ πi₂ : ∀ J : Box ι, Prepartition J}
@[simp]
theorem mem_biUnion : J ∈ π.biUnion πi ↔ ∃ J' ∈ π, J ∈ πi J' := by simp [biUnion]
#align box_integral.prepartition.mem_bUnion BoxIntegral.Prepartition.mem_biUnion
theorem biUnion_le (πi : ∀ J, Prepartition J) : π.biUnion πi ≤ π := fun _ hJ =>
let ⟨J', hJ', hJ⟩ := π.mem_biUnion.1 hJ
⟨J', hJ', (πi J').le_of_mem hJ⟩
#align box_integral.prepartition.bUnion_le BoxIntegral.Prepartition.biUnion_le
@[simp]
theorem biUnion_top : (π.biUnion fun _ => ⊤) = π := by
ext
simp
#align box_integral.prepartition.bUnion_top BoxIntegral.Prepartition.biUnion_top
@[congr]
theorem biUnion_congr (h : π₁ = π₂) (hi : ∀ J ∈ π₁, πi₁ J = πi₂ J) :
π₁.biUnion πi₁ = π₂.biUnion πi₂ := by
subst π₂
ext J
simp only [mem_biUnion]
constructor <;> exact fun ⟨J', h₁, h₂⟩ => ⟨J', h₁, hi J' h₁ ▸ h₂⟩
#align box_integral.prepartition.bUnion_congr BoxIntegral.Prepartition.biUnion_congr
theorem biUnion_congr_of_le (h : π₁ = π₂) (hi : ∀ J ≤ I, πi₁ J = πi₂ J) :
π₁.biUnion πi₁ = π₂.biUnion πi₂ :=
biUnion_congr h fun J hJ => hi J (π₁.le_of_mem hJ)
#align box_integral.prepartition.bUnion_congr_of_le BoxIntegral.Prepartition.biUnion_congr_of_le
@[simp]
theorem iUnion_biUnion (πi : ∀ J : Box ι, Prepartition J) :
(π.biUnion πi).iUnion = ⋃ J ∈ π, (πi J).iUnion := by simp [Prepartition.iUnion]
#align box_integral.prepartition.Union_bUnion BoxIntegral.Prepartition.iUnion_biUnion
@[simp]
theorem sum_biUnion_boxes {M : Type*} [AddCommMonoid M] (π : Prepartition I)
(πi : ∀ J, Prepartition J) (f : Box ι → M) :
(∑ J ∈ π.boxes.biUnion fun J => (πi J).boxes, f J) =
∑ J ∈ π.boxes, ∑ J' ∈ (πi J).boxes, f J' := by
refine Finset.sum_biUnion fun J₁ h₁ J₂ h₂ hne => Finset.disjoint_left.2 fun J' h₁' h₂' => ?_
exact hne (π.eq_of_le_of_le h₁ h₂ ((πi J₁).le_of_mem h₁') ((πi J₂).le_of_mem h₂'))
#align box_integral.prepartition.sum_bUnion_boxes BoxIntegral.Prepartition.sum_biUnion_boxes
def biUnionIndex (πi : ∀ (J : Box ι), Prepartition J) (J : Box ι) : Box ι :=
if hJ : J ∈ π.biUnion πi then (π.mem_biUnion.1 hJ).choose else I
#align box_integral.prepartition.bUnion_index BoxIntegral.Prepartition.biUnionIndex
theorem biUnionIndex_mem (hJ : J ∈ π.biUnion πi) : π.biUnionIndex πi J ∈ π := by
rw [biUnionIndex, dif_pos hJ]
exact (π.mem_biUnion.1 hJ).choose_spec.1
#align box_integral.prepartition.bUnion_index_mem BoxIntegral.Prepartition.biUnionIndex_mem
theorem biUnionIndex_le (πi : ∀ J, Prepartition J) (J : Box ι) : π.biUnionIndex πi J ≤ I := by
by_cases hJ : J ∈ π.biUnion πi
· exact π.le_of_mem (π.biUnionIndex_mem hJ)
· rw [biUnionIndex, dif_neg hJ]
#align box_integral.prepartition.bUnion_index_le BoxIntegral.Prepartition.biUnionIndex_le
theorem mem_biUnionIndex (hJ : J ∈ π.biUnion πi) : J ∈ πi (π.biUnionIndex πi J) := by
convert (π.mem_biUnion.1 hJ).choose_spec.2 <;> exact dif_pos hJ
#align box_integral.prepartition.mem_bUnion_index BoxIntegral.Prepartition.mem_biUnionIndex
theorem le_biUnionIndex (hJ : J ∈ π.biUnion πi) : J ≤ π.biUnionIndex πi J :=
le_of_mem _ (π.mem_biUnionIndex hJ)
#align box_integral.prepartition.le_bUnion_index BoxIntegral.Prepartition.le_biUnionIndex
theorem biUnionIndex_of_mem (hJ : J ∈ π) {J'} (hJ' : J' ∈ πi J) : π.biUnionIndex πi J' = J :=
have : J' ∈ π.biUnion πi := π.mem_biUnion.2 ⟨J, hJ, hJ'⟩
π.eq_of_le_of_le (π.biUnionIndex_mem this) hJ (π.le_biUnionIndex this) (le_of_mem _ hJ')
#align box_integral.prepartition.bUnion_index_of_mem BoxIntegral.Prepartition.biUnionIndex_of_mem
theorem biUnion_assoc (πi : ∀ J, Prepartition J) (πi' : Box ι → ∀ J : Box ι, Prepartition J) :
(π.biUnion fun J => (πi J).biUnion (πi' J)) =
(π.biUnion πi).biUnion fun J => πi' (π.biUnionIndex πi J) J := by
ext J
simp only [mem_biUnion, exists_prop]
constructor
· rintro ⟨J₁, hJ₁, J₂, hJ₂, hJ⟩
refine ⟨J₂, ⟨J₁, hJ₁, hJ₂⟩, ?_⟩
rwa [π.biUnionIndex_of_mem hJ₁ hJ₂]
· rintro ⟨J₁, ⟨J₂, hJ₂, hJ₁⟩, hJ⟩
refine ⟨J₂, hJ₂, J₁, hJ₁, ?_⟩
rwa [π.biUnionIndex_of_mem hJ₂ hJ₁] at hJ
#align box_integral.prepartition.bUnion_assoc BoxIntegral.Prepartition.biUnion_assoc
def ofWithBot (boxes : Finset (WithBot (Box ι)))
(le_of_mem : ∀ J ∈ boxes, (J : WithBot (Box ι)) ≤ I)
(pairwise_disjoint : Set.Pairwise (boxes : Set (WithBot (Box ι))) Disjoint) :
Prepartition I where
boxes := Finset.eraseNone boxes
le_of_mem' J hJ := by
rw [mem_eraseNone] at hJ
simpa only [WithBot.some_eq_coe, WithBot.coe_le_coe] using le_of_mem _ hJ
pairwiseDisjoint J₁ h₁ J₂ h₂ hne := by
simp only [mem_coe, mem_eraseNone] at h₁ h₂
exact Box.disjoint_coe.1 (pairwise_disjoint h₁ h₂ (mt Option.some_inj.1 hne))
#align box_integral.prepartition.of_with_bot BoxIntegral.Prepartition.ofWithBot
@[simp]
theorem mem_ofWithBot {boxes : Finset (WithBot (Box ι))} {h₁ h₂} :
J ∈ (ofWithBot boxes h₁ h₂ : Prepartition I) ↔ (J : WithBot (Box ι)) ∈ boxes :=
mem_eraseNone
#align box_integral.prepartition.mem_of_with_bot BoxIntegral.Prepartition.mem_ofWithBot
@[simp]
theorem iUnion_ofWithBot (boxes : Finset (WithBot (Box ι)))
(le_of_mem : ∀ J ∈ boxes, (J : WithBot (Box ι)) ≤ I)
(pairwise_disjoint : Set.Pairwise (boxes : Set (WithBot (Box ι))) Disjoint) :
(ofWithBot boxes le_of_mem pairwise_disjoint).iUnion = ⋃ J ∈ boxes, ↑J := by
suffices ⋃ (J : Box ι) (_ : ↑J ∈ boxes), ↑J = ⋃ J ∈ boxes, (J : Set (ι → ℝ)) by
simpa [ofWithBot, Prepartition.iUnion]
simp only [← Box.biUnion_coe_eq_coe, @iUnion_comm _ _ (Box ι), @iUnion_comm _ _ (@Eq _ _ _),
iUnion_iUnion_eq_right]
#align box_integral.prepartition.Union_of_with_bot BoxIntegral.Prepartition.iUnion_ofWithBot
theorem ofWithBot_le {boxes : Finset (WithBot (Box ι))}
{le_of_mem : ∀ J ∈ boxes, (J : WithBot (Box ι)) ≤ I}
{pairwise_disjoint : Set.Pairwise (boxes : Set (WithBot (Box ι))) Disjoint}
(H : ∀ J ∈ boxes, J ≠ ⊥ → ∃ J' ∈ π, J ≤ ↑J') :
ofWithBot boxes le_of_mem pairwise_disjoint ≤ π := by
have : ∀ J : Box ι, ↑J ∈ boxes → ∃ J' ∈ π, J ≤ J' := fun J hJ => by
simpa only [WithBot.coe_le_coe] using H J hJ WithBot.coe_ne_bot
simpa [ofWithBot, le_def]
#align box_integral.prepartition.of_with_bot_le BoxIntegral.Prepartition.ofWithBot_le
theorem le_ofWithBot {boxes : Finset (WithBot (Box ι))}
{le_of_mem : ∀ J ∈ boxes, (J : WithBot (Box ι)) ≤ I}
{pairwise_disjoint : Set.Pairwise (boxes : Set (WithBot (Box ι))) Disjoint}
(H : ∀ J ∈ π, ∃ J' ∈ boxes, ↑J ≤ J') : π ≤ ofWithBot boxes le_of_mem pairwise_disjoint := by
intro J hJ
rcases H J hJ with ⟨J', J'mem, hle⟩
lift J' to Box ι using ne_bot_of_le_ne_bot WithBot.coe_ne_bot hle
exact ⟨J', mem_ofWithBot.2 J'mem, WithBot.coe_le_coe.1 hle⟩
#align box_integral.prepartition.le_of_with_bot BoxIntegral.Prepartition.le_ofWithBot
theorem ofWithBot_mono {boxes₁ : Finset (WithBot (Box ι))}
{le_of_mem₁ : ∀ J ∈ boxes₁, (J : WithBot (Box ι)) ≤ I}
{pairwise_disjoint₁ : Set.Pairwise (boxes₁ : Set (WithBot (Box ι))) Disjoint}
{boxes₂ : Finset (WithBot (Box ι))} {le_of_mem₂ : ∀ J ∈ boxes₂, (J : WithBot (Box ι)) ≤ I}
{pairwise_disjoint₂ : Set.Pairwise (boxes₂ : Set (WithBot (Box ι))) Disjoint}
(H : ∀ J ∈ boxes₁, J ≠ ⊥ → ∃ J' ∈ boxes₂, J ≤ J') :
ofWithBot boxes₁ le_of_mem₁ pairwise_disjoint₁ ≤
ofWithBot boxes₂ le_of_mem₂ pairwise_disjoint₂ :=
le_ofWithBot _ fun J hJ => H J (mem_ofWithBot.1 hJ) WithBot.coe_ne_bot
#align box_integral.prepartition.of_with_bot_mono BoxIntegral.Prepartition.ofWithBot_mono
theorem sum_ofWithBot {M : Type*} [AddCommMonoid M] (boxes : Finset (WithBot (Box ι)))
(le_of_mem : ∀ J ∈ boxes, (J : WithBot (Box ι)) ≤ I)
(pairwise_disjoint : Set.Pairwise (boxes : Set (WithBot (Box ι))) Disjoint) (f : Box ι → M) :
(∑ J ∈ (ofWithBot boxes le_of_mem pairwise_disjoint).boxes, f J) =
∑ J ∈ boxes, Option.elim' 0 f J :=
Finset.sum_eraseNone _ _
#align box_integral.prepartition.sum_of_with_bot BoxIntegral.Prepartition.sum_ofWithBot
def restrict (π : Prepartition I) (J : Box ι) : Prepartition J :=
ofWithBot (π.boxes.image fun J' : Box ι => J ⊓ J')
(fun J' hJ' => by
rcases Finset.mem_image.1 hJ' with ⟨J', -, rfl⟩
exact inf_le_left)
(by
simp only [Set.Pairwise, onFun, Finset.mem_coe, Finset.mem_image]
rintro _ ⟨J₁, h₁, rfl⟩ _ ⟨J₂, h₂, rfl⟩ Hne
have : J₁ ≠ J₂ := by
rintro rfl
exact Hne rfl
exact ((Box.disjoint_coe.2 <| π.disjoint_coe_of_mem h₁ h₂ this).inf_left' _).inf_right' _)
#align box_integral.prepartition.restrict BoxIntegral.Prepartition.restrict
@[simp]
theorem mem_restrict : J₁ ∈ π.restrict J ↔ ∃ J' ∈ π, (J₁ : WithBot (Box ι)) = ↑J ⊓ ↑J' := by
simp [restrict, eq_comm]
#align box_integral.prepartition.mem_restrict BoxIntegral.Prepartition.mem_restrict
theorem mem_restrict' : J₁ ∈ π.restrict J ↔ ∃ J' ∈ π, (J₁ : Set (ι → ℝ)) = ↑J ∩ ↑J' := by
simp only [mem_restrict, ← Box.withBotCoe_inj, Box.coe_inf, Box.coe_coe]
#align box_integral.prepartition.mem_restrict' BoxIntegral.Prepartition.mem_restrict'
@[mono]
theorem restrict_mono {π₁ π₂ : Prepartition I} (Hle : π₁ ≤ π₂) : π₁.restrict J ≤ π₂.restrict J := by
refine ofWithBot_mono fun J₁ hJ₁ hne => ?_
rw [Finset.mem_image] at hJ₁; rcases hJ₁ with ⟨J₁, hJ₁, rfl⟩
rcases Hle hJ₁ with ⟨J₂, hJ₂, hle⟩
exact ⟨_, Finset.mem_image_of_mem _ hJ₂, inf_le_inf_left _ <| WithBot.coe_le_coe.2 hle⟩
#align box_integral.prepartition.restrict_mono BoxIntegral.Prepartition.restrict_mono
theorem monotone_restrict : Monotone fun π : Prepartition I => restrict π J :=
fun _ _ => restrict_mono
#align box_integral.prepartition.monotone_restrict BoxIntegral.Prepartition.monotone_restrict
theorem restrict_boxes_of_le (π : Prepartition I) (h : I ≤ J) : (π.restrict J).boxes = π.boxes := by
simp only [restrict, ofWithBot, eraseNone_eq_biUnion]
refine Finset.image_biUnion.trans ?_
refine (Finset.biUnion_congr rfl ?_).trans Finset.biUnion_singleton_eq_self
intro J' hJ'
rw [inf_of_le_right, ← WithBot.some_eq_coe, Option.toFinset_some]
exact WithBot.coe_le_coe.2 ((π.le_of_mem hJ').trans h)
#align box_integral.prepartition.restrict_boxes_of_le BoxIntegral.Prepartition.restrict_boxes_of_le
@[simp]
theorem restrict_self : π.restrict I = π :=
injective_boxes <| restrict_boxes_of_le π le_rfl
#align box_integral.prepartition.restrict_self BoxIntegral.Prepartition.restrict_self
@[simp]
theorem iUnion_restrict : (π.restrict J).iUnion = (J : Set (ι → ℝ)) ∩ (π.iUnion) := by
simp [restrict, ← inter_iUnion, ← iUnion_def]
#align box_integral.prepartition.Union_restrict BoxIntegral.Prepartition.iUnion_restrict
@[simp]
theorem restrict_biUnion (πi : ∀ J, Prepartition J) (hJ : J ∈ π) :
(π.biUnion πi).restrict J = πi J := by
refine (eq_of_boxes_subset_iUnion_superset (fun J₁ h₁ => ?_) ?_).symm
· refine (mem_restrict _).2 ⟨J₁, π.mem_biUnion.2 ⟨J, hJ, h₁⟩, (inf_of_le_right ?_).symm⟩
exact WithBot.coe_le_coe.2 (le_of_mem _ h₁)
· simp only [iUnion_restrict, iUnion_biUnion, Set.subset_def, Set.mem_inter_iff, Set.mem_iUnion]
rintro x ⟨hxJ, J₁, h₁, hx⟩
obtain rfl : J = J₁ := π.eq_of_mem_of_mem hJ h₁ hxJ (iUnion_subset _ hx)
exact hx
#align box_integral.prepartition.restrict_bUnion BoxIntegral.Prepartition.restrict_biUnion
theorem biUnion_le_iff {πi : ∀ J, Prepartition J} {π' : Prepartition I} :
π.biUnion πi ≤ π' ↔ ∀ J ∈ π, πi J ≤ π'.restrict J := by
constructor <;> intro H J hJ
· rw [← π.restrict_biUnion πi hJ]
exact restrict_mono H
· rw [mem_biUnion] at hJ
rcases hJ with ⟨J₁, h₁, hJ⟩
rcases H J₁ h₁ hJ with ⟨J₂, h₂, Hle⟩
rcases π'.mem_restrict.mp h₂ with ⟨J₃, h₃, H⟩
exact ⟨J₃, h₃, Hle.trans <| WithBot.coe_le_coe.1 <| H.trans_le inf_le_right⟩
#align box_integral.prepartition.bUnion_le_iff BoxIntegral.Prepartition.biUnion_le_iff
theorem le_biUnion_iff {πi : ∀ J, Prepartition J} {π' : Prepartition I} :
π' ≤ π.biUnion πi ↔ π' ≤ π ∧ ∀ J ∈ π, π'.restrict J ≤ πi J := by
refine ⟨fun H => ⟨H.trans (π.biUnion_le πi), fun J hJ => ?_⟩, ?_⟩
· rw [← π.restrict_biUnion πi hJ]
exact restrict_mono H
· rintro ⟨H, Hi⟩ J' hJ'
rcases H hJ' with ⟨J, hJ, hle⟩
have : J' ∈ π'.restrict J :=
π'.mem_restrict.2 ⟨J', hJ', (inf_of_le_right <| WithBot.coe_le_coe.2 hle).symm⟩
rcases Hi J hJ this with ⟨Ji, hJi, hlei⟩
exact ⟨Ji, π.mem_biUnion.2 ⟨J, hJ, hJi⟩, hlei⟩
#align box_integral.prepartition.le_bUnion_iff BoxIntegral.Prepartition.le_biUnion_iff
instance inf : Inf (Prepartition I) :=
⟨fun π₁ π₂ => π₁.biUnion fun J => π₂.restrict J⟩
theorem inf_def (π₁ π₂ : Prepartition I) : π₁ ⊓ π₂ = π₁.biUnion fun J => π₂.restrict J := rfl
#align box_integral.prepartition.inf_def BoxIntegral.Prepartition.inf_def
@[simp]
theorem mem_inf {π₁ π₂ : Prepartition I} :
J ∈ π₁ ⊓ π₂ ↔ ∃ J₁ ∈ π₁, ∃ J₂ ∈ π₂, (J : WithBot (Box ι)) = ↑J₁ ⊓ ↑J₂ := by
simp only [inf_def, mem_biUnion, mem_restrict]
#align box_integral.prepartition.mem_inf BoxIntegral.Prepartition.mem_inf
@[simp]
theorem iUnion_inf (π₁ π₂ : Prepartition I) : (π₁ ⊓ π₂).iUnion = π₁.iUnion ∩ π₂.iUnion := by
simp only [inf_def, iUnion_biUnion, iUnion_restrict, ← iUnion_inter, ← iUnion_def]
#align box_integral.prepartition.Union_inf BoxIntegral.Prepartition.iUnion_inf
instance : SemilatticeInf (Prepartition I) :=
{ Prepartition.inf,
Prepartition.partialOrder with
inf_le_left := fun π₁ _ => π₁.biUnion_le _
inf_le_right := fun _ _ => (biUnion_le_iff _).2 fun _ _ => le_rfl
le_inf := fun _ π₁ _ h₁ h₂ => π₁.le_biUnion_iff.2 ⟨h₁, fun _ _ => restrict_mono h₂⟩ }
@[simps]
def filter (π : Prepartition I) (p : Box ι → Prop) : Prepartition I where
boxes := π.boxes.filter p
le_of_mem' _ hJ := π.le_of_mem (mem_filter.1 hJ).1
pairwiseDisjoint _ h₁ _ h₂ := π.disjoint_coe_of_mem (mem_filter.1 h₁).1 (mem_filter.1 h₂).1
#align box_integral.prepartition.filter BoxIntegral.Prepartition.filter
@[simp]
theorem mem_filter {p : Box ι → Prop} : J ∈ π.filter p ↔ J ∈ π ∧ p J :=
Finset.mem_filter
#align box_integral.prepartition.mem_filter BoxIntegral.Prepartition.mem_filter
theorem filter_le (π : Prepartition I) (p : Box ι → Prop) : π.filter p ≤ π := fun J hJ =>
let ⟨hπ, _⟩ := π.mem_filter.1 hJ
⟨J, hπ, le_rfl⟩
#align box_integral.prepartition.filter_le BoxIntegral.Prepartition.filter_le
| Mathlib/Analysis/BoxIntegral/Partition/Basic.lean | 611 | 613 | theorem filter_of_true {p : Box ι → Prop} (hp : ∀ J ∈ π, p J) : π.filter p = π := by |
ext J
simpa using hp J
|
import Mathlib.Algebra.Polynomial.AlgebraMap
import Mathlib.Algebra.Polynomial.BigOperators
import Mathlib.Algebra.Polynomial.Degree.Lemmas
import Mathlib.Algebra.Polynomial.Div
#align_import data.polynomial.ring_division from "leanprover-community/mathlib"@"8efcf8022aac8e01df8d302dcebdbc25d6a886c8"
noncomputable section
open Polynomial
open Finset
namespace Polynomial
universe u v w z
variable {R : Type u} {S : Type v} {T : Type w} {a b : R} {n : ℕ}
section NoZeroDivisors
variable [Semiring R] [NoZeroDivisors R] {p q : R[X]}
instance : NoZeroDivisors R[X] where
eq_zero_or_eq_zero_of_mul_eq_zero h := by
rw [← leadingCoeff_eq_zero, ← leadingCoeff_eq_zero]
refine eq_zero_or_eq_zero_of_mul_eq_zero ?_
rw [← leadingCoeff_zero, ← leadingCoeff_mul, h]
theorem natDegree_mul (hp : p ≠ 0) (hq : q ≠ 0) : (p*q).natDegree = p.natDegree + q.natDegree := by
rw [← Nat.cast_inj (R := WithBot ℕ), ← degree_eq_natDegree (mul_ne_zero hp hq),
Nat.cast_add, ← degree_eq_natDegree hp, ← degree_eq_natDegree hq, degree_mul]
#align polynomial.nat_degree_mul Polynomial.natDegree_mul
theorem trailingDegree_mul : (p * q).trailingDegree = p.trailingDegree + q.trailingDegree := by
by_cases hp : p = 0
· rw [hp, zero_mul, trailingDegree_zero, top_add]
by_cases hq : q = 0
· rw [hq, mul_zero, trailingDegree_zero, add_top]
· rw [trailingDegree_eq_natTrailingDegree hp, trailingDegree_eq_natTrailingDegree hq,
trailingDegree_eq_natTrailingDegree (mul_ne_zero hp hq), natTrailingDegree_mul hp hq]
apply WithTop.coe_add
#align polynomial.trailing_degree_mul Polynomial.trailingDegree_mul
@[simp]
theorem natDegree_pow (p : R[X]) (n : ℕ) : natDegree (p ^ n) = n * natDegree p := by
classical
obtain rfl | hp := eq_or_ne p 0
· obtain rfl | hn := eq_or_ne n 0 <;> simp [*]
exact natDegree_pow' $ by
rw [← leadingCoeff_pow, Ne, leadingCoeff_eq_zero]; exact pow_ne_zero _ hp
#align polynomial.nat_degree_pow Polynomial.natDegree_pow
theorem degree_le_mul_left (p : R[X]) (hq : q ≠ 0) : degree p ≤ degree (p * q) := by
classical
exact if hp : p = 0 then by simp only [hp, zero_mul, le_refl]
else by
rw [degree_mul, degree_eq_natDegree hp, degree_eq_natDegree hq];
exact WithBot.coe_le_coe.2 (Nat.le_add_right _ _)
#align polynomial.degree_le_mul_left Polynomial.degree_le_mul_left
theorem natDegree_le_of_dvd {p q : R[X]} (h1 : p ∣ q) (h2 : q ≠ 0) : p.natDegree ≤ q.natDegree := by
rcases h1 with ⟨q, rfl⟩; rw [mul_ne_zero_iff] at h2
rw [natDegree_mul h2.1 h2.2]; exact Nat.le_add_right _ _
#align polynomial.nat_degree_le_of_dvd Polynomial.natDegree_le_of_dvd
theorem degree_le_of_dvd {p q : R[X]} (h1 : p ∣ q) (h2 : q ≠ 0) : degree p ≤ degree q := by
rcases h1 with ⟨q, rfl⟩; rw [mul_ne_zero_iff] at h2
exact degree_le_mul_left p h2.2
#align polynomial.degree_le_of_dvd Polynomial.degree_le_of_dvd
theorem eq_zero_of_dvd_of_degree_lt {p q : R[X]} (h₁ : p ∣ q) (h₂ : degree q < degree p) :
q = 0 := by
by_contra hc
exact (lt_iff_not_ge _ _).mp h₂ (degree_le_of_dvd h₁ hc)
#align polynomial.eq_zero_of_dvd_of_degree_lt Polynomial.eq_zero_of_dvd_of_degree_lt
theorem eq_zero_of_dvd_of_natDegree_lt {p q : R[X]} (h₁ : p ∣ q) (h₂ : natDegree q < natDegree p) :
q = 0 := by
by_contra hc
exact (lt_iff_not_ge _ _).mp h₂ (natDegree_le_of_dvd h₁ hc)
#align polynomial.eq_zero_of_dvd_of_nat_degree_lt Polynomial.eq_zero_of_dvd_of_natDegree_lt
theorem not_dvd_of_degree_lt {p q : R[X]} (h0 : q ≠ 0) (hl : q.degree < p.degree) : ¬p ∣ q := by
by_contra hcontra
exact h0 (eq_zero_of_dvd_of_degree_lt hcontra hl)
#align polynomial.not_dvd_of_degree_lt Polynomial.not_dvd_of_degree_lt
theorem not_dvd_of_natDegree_lt {p q : R[X]} (h0 : q ≠ 0) (hl : q.natDegree < p.natDegree) :
¬p ∣ q := by
by_contra hcontra
exact h0 (eq_zero_of_dvd_of_natDegree_lt hcontra hl)
#align polynomial.not_dvd_of_nat_degree_lt Polynomial.not_dvd_of_natDegree_lt
theorem natDegree_sub_eq_of_prod_eq {p₁ p₂ q₁ q₂ : R[X]} (hp₁ : p₁ ≠ 0) (hq₁ : q₁ ≠ 0)
(hp₂ : p₂ ≠ 0) (hq₂ : q₂ ≠ 0) (h_eq : p₁ * q₂ = p₂ * q₁) :
(p₁.natDegree : ℤ) - q₁.natDegree = (p₂.natDegree : ℤ) - q₂.natDegree := by
rw [sub_eq_sub_iff_add_eq_add]
norm_cast
rw [← natDegree_mul hp₁ hq₂, ← natDegree_mul hp₂ hq₁, h_eq]
#align polynomial.nat_degree_sub_eq_of_prod_eq Polynomial.natDegree_sub_eq_of_prod_eq
theorem natDegree_eq_zero_of_isUnit (h : IsUnit p) : natDegree p = 0 := by
nontriviality R
obtain ⟨q, hq⟩ := h.exists_right_inv
have := natDegree_mul (left_ne_zero_of_mul_eq_one hq) (right_ne_zero_of_mul_eq_one hq)
rw [hq, natDegree_one, eq_comm, add_eq_zero_iff] at this
exact this.1
#align polynomial.nat_degree_eq_zero_of_is_unit Polynomial.natDegree_eq_zero_of_isUnit
theorem degree_eq_zero_of_isUnit [Nontrivial R] (h : IsUnit p) : degree p = 0 :=
(natDegree_eq_zero_iff_degree_le_zero.mp <| natDegree_eq_zero_of_isUnit h).antisymm
(zero_le_degree_iff.mpr h.ne_zero)
#align polynomial.degree_eq_zero_of_is_unit Polynomial.degree_eq_zero_of_isUnit
@[simp]
theorem degree_coe_units [Nontrivial R] (u : R[X]ˣ) : degree (u : R[X]) = 0 :=
degree_eq_zero_of_isUnit ⟨u, rfl⟩
#align polynomial.degree_coe_units Polynomial.degree_coe_units
theorem isUnit_iff : IsUnit p ↔ ∃ r : R, IsUnit r ∧ C r = p :=
⟨fun hp =>
⟨p.coeff 0,
let h := eq_C_of_natDegree_eq_zero (natDegree_eq_zero_of_isUnit hp)
⟨isUnit_C.1 (h ▸ hp), h.symm⟩⟩,
fun ⟨_, hr, hrp⟩ => hrp ▸ isUnit_C.2 hr⟩
#align polynomial.is_unit_iff Polynomial.isUnit_iff
| Mathlib/Algebra/Polynomial/RingDivision.lean | 226 | 231 | theorem not_isUnit_of_degree_pos (p : R[X])
(hpl : 0 < p.degree) : ¬ IsUnit p := by |
cases subsingleton_or_nontrivial R
· simp [Subsingleton.elim p 0] at hpl
intro h
simp [degree_eq_zero_of_isUnit h] at hpl
|
import Mathlib.Order.Interval.Set.Basic
import Mathlib.Order.Hom.Set
#align_import data.set.intervals.order_iso from "leanprover-community/mathlib"@"d012cd09a9b256d870751284dd6a29882b0be105"
open Set
namespace OrderIso
section Preorder
variable {α β : Type*} [Preorder α] [Preorder β]
@[simp]
theorem preimage_Iic (e : α ≃o β) (b : β) : e ⁻¹' Iic b = Iic (e.symm b) := by
ext x
simp [← e.le_iff_le]
#align order_iso.preimage_Iic OrderIso.preimage_Iic
@[simp]
theorem preimage_Ici (e : α ≃o β) (b : β) : e ⁻¹' Ici b = Ici (e.symm b) := by
ext x
simp [← e.le_iff_le]
#align order_iso.preimage_Ici OrderIso.preimage_Ici
@[simp]
theorem preimage_Iio (e : α ≃o β) (b : β) : e ⁻¹' Iio b = Iio (e.symm b) := by
ext x
simp [← e.lt_iff_lt]
#align order_iso.preimage_Iio OrderIso.preimage_Iio
@[simp]
theorem preimage_Ioi (e : α ≃o β) (b : β) : e ⁻¹' Ioi b = Ioi (e.symm b) := by
ext x
simp [← e.lt_iff_lt]
#align order_iso.preimage_Ioi OrderIso.preimage_Ioi
@[simp]
theorem preimage_Icc (e : α ≃o β) (a b : β) : e ⁻¹' Icc a b = Icc (e.symm a) (e.symm b) := by
simp [← Ici_inter_Iic]
#align order_iso.preimage_Icc OrderIso.preimage_Icc
@[simp]
theorem preimage_Ico (e : α ≃o β) (a b : β) : e ⁻¹' Ico a b = Ico (e.symm a) (e.symm b) := by
simp [← Ici_inter_Iio]
#align order_iso.preimage_Ico OrderIso.preimage_Ico
@[simp]
theorem preimage_Ioc (e : α ≃o β) (a b : β) : e ⁻¹' Ioc a b = Ioc (e.symm a) (e.symm b) := by
simp [← Ioi_inter_Iic]
#align order_iso.preimage_Ioc OrderIso.preimage_Ioc
@[simp]
theorem preimage_Ioo (e : α ≃o β) (a b : β) : e ⁻¹' Ioo a b = Ioo (e.symm a) (e.symm b) := by
simp [← Ioi_inter_Iio]
#align order_iso.preimage_Ioo OrderIso.preimage_Ioo
@[simp]
| Mathlib/Order/Interval/Set/OrderIso.lean | 68 | 69 | theorem image_Iic (e : α ≃o β) (a : α) : e '' Iic a = Iic (e a) := by |
rw [e.image_eq_preimage, e.symm.preimage_Iic, e.symm_symm]
|
import Mathlib.Analysis.Convex.Side
import Mathlib.Geometry.Euclidean.Angle.Oriented.Rotation
import Mathlib.Geometry.Euclidean.Angle.Unoriented.Affine
#align_import geometry.euclidean.angle.oriented.affine from "leanprover-community/mathlib"@"46b633fd842bef9469441c0209906f6dddd2b4f5"
noncomputable section
open FiniteDimensional Complex
open scoped Affine EuclideanGeometry Real RealInnerProductSpace ComplexConjugate
namespace EuclideanGeometry
variable {V : Type*} {P : Type*} [NormedAddCommGroup V] [InnerProductSpace ℝ V] [MetricSpace P]
[NormedAddTorsor V P] [hd2 : Fact (finrank ℝ V = 2)] [Module.Oriented ℝ V (Fin 2)]
abbrev o := @Module.Oriented.positiveOrientation
def oangle (p₁ p₂ p₃ : P) : Real.Angle :=
o.oangle (p₁ -ᵥ p₂) (p₃ -ᵥ p₂)
#align euclidean_geometry.oangle EuclideanGeometry.oangle
@[inherit_doc] scoped notation "∡" => EuclideanGeometry.oangle
theorem continuousAt_oangle {x : P × P × P} (hx12 : x.1 ≠ x.2.1) (hx32 : x.2.2 ≠ x.2.1) :
ContinuousAt (fun y : P × P × P => ∡ y.1 y.2.1 y.2.2) x := by
let f : P × P × P → V × V := fun y => (y.1 -ᵥ y.2.1, y.2.2 -ᵥ y.2.1)
have hf1 : (f x).1 ≠ 0 := by simp [hx12]
have hf2 : (f x).2 ≠ 0 := by simp [hx32]
exact (o.continuousAt_oangle hf1 hf2).comp ((continuous_fst.vsub continuous_snd.fst).prod_mk
(continuous_snd.snd.vsub continuous_snd.fst)).continuousAt
#align euclidean_geometry.continuous_at_oangle EuclideanGeometry.continuousAt_oangle
@[simp]
theorem oangle_self_left (p₁ p₂ : P) : ∡ p₁ p₁ p₂ = 0 := by simp [oangle]
#align euclidean_geometry.oangle_self_left EuclideanGeometry.oangle_self_left
@[simp]
theorem oangle_self_right (p₁ p₂ : P) : ∡ p₁ p₂ p₂ = 0 := by simp [oangle]
#align euclidean_geometry.oangle_self_right EuclideanGeometry.oangle_self_right
@[simp]
theorem oangle_self_left_right (p₁ p₂ : P) : ∡ p₁ p₂ p₁ = 0 :=
o.oangle_self _
#align euclidean_geometry.oangle_self_left_right EuclideanGeometry.oangle_self_left_right
theorem left_ne_of_oangle_ne_zero {p₁ p₂ p₃ : P} (h : ∡ p₁ p₂ p₃ ≠ 0) : p₁ ≠ p₂ := by
rw [← @vsub_ne_zero V]; exact o.left_ne_zero_of_oangle_ne_zero h
#align euclidean_geometry.left_ne_of_oangle_ne_zero EuclideanGeometry.left_ne_of_oangle_ne_zero
theorem right_ne_of_oangle_ne_zero {p₁ p₂ p₃ : P} (h : ∡ p₁ p₂ p₃ ≠ 0) : p₃ ≠ p₂ := by
rw [← @vsub_ne_zero V]; exact o.right_ne_zero_of_oangle_ne_zero h
#align euclidean_geometry.right_ne_of_oangle_ne_zero EuclideanGeometry.right_ne_of_oangle_ne_zero
theorem left_ne_right_of_oangle_ne_zero {p₁ p₂ p₃ : P} (h : ∡ p₁ p₂ p₃ ≠ 0) : p₁ ≠ p₃ := by
rw [← (vsub_left_injective p₂).ne_iff]; exact o.ne_of_oangle_ne_zero h
#align euclidean_geometry.left_ne_right_of_oangle_ne_zero EuclideanGeometry.left_ne_right_of_oangle_ne_zero
theorem left_ne_of_oangle_eq_pi {p₁ p₂ p₃ : P} (h : ∡ p₁ p₂ p₃ = π) : p₁ ≠ p₂ :=
left_ne_of_oangle_ne_zero (h.symm ▸ Real.Angle.pi_ne_zero : ∡ p₁ p₂ p₃ ≠ 0)
#align euclidean_geometry.left_ne_of_oangle_eq_pi EuclideanGeometry.left_ne_of_oangle_eq_pi
theorem right_ne_of_oangle_eq_pi {p₁ p₂ p₃ : P} (h : ∡ p₁ p₂ p₃ = π) : p₃ ≠ p₂ :=
right_ne_of_oangle_ne_zero (h.symm ▸ Real.Angle.pi_ne_zero : ∡ p₁ p₂ p₃ ≠ 0)
#align euclidean_geometry.right_ne_of_oangle_eq_pi EuclideanGeometry.right_ne_of_oangle_eq_pi
theorem left_ne_right_of_oangle_eq_pi {p₁ p₂ p₃ : P} (h : ∡ p₁ p₂ p₃ = π) : p₁ ≠ p₃ :=
left_ne_right_of_oangle_ne_zero (h.symm ▸ Real.Angle.pi_ne_zero : ∡ p₁ p₂ p₃ ≠ 0)
#align euclidean_geometry.left_ne_right_of_oangle_eq_pi EuclideanGeometry.left_ne_right_of_oangle_eq_pi
theorem left_ne_of_oangle_eq_pi_div_two {p₁ p₂ p₃ : P} (h : ∡ p₁ p₂ p₃ = (π / 2 : ℝ)) : p₁ ≠ p₂ :=
left_ne_of_oangle_ne_zero (h.symm ▸ Real.Angle.pi_div_two_ne_zero : ∡ p₁ p₂ p₃ ≠ 0)
#align euclidean_geometry.left_ne_of_oangle_eq_pi_div_two EuclideanGeometry.left_ne_of_oangle_eq_pi_div_two
theorem right_ne_of_oangle_eq_pi_div_two {p₁ p₂ p₃ : P} (h : ∡ p₁ p₂ p₃ = (π / 2 : ℝ)) : p₃ ≠ p₂ :=
right_ne_of_oangle_ne_zero (h.symm ▸ Real.Angle.pi_div_two_ne_zero : ∡ p₁ p₂ p₃ ≠ 0)
#align euclidean_geometry.right_ne_of_oangle_eq_pi_div_two EuclideanGeometry.right_ne_of_oangle_eq_pi_div_two
theorem left_ne_right_of_oangle_eq_pi_div_two {p₁ p₂ p₃ : P} (h : ∡ p₁ p₂ p₃ = (π / 2 : ℝ)) :
p₁ ≠ p₃ :=
left_ne_right_of_oangle_ne_zero (h.symm ▸ Real.Angle.pi_div_two_ne_zero : ∡ p₁ p₂ p₃ ≠ 0)
#align euclidean_geometry.left_ne_right_of_oangle_eq_pi_div_two EuclideanGeometry.left_ne_right_of_oangle_eq_pi_div_two
theorem left_ne_of_oangle_eq_neg_pi_div_two {p₁ p₂ p₃ : P} (h : ∡ p₁ p₂ p₃ = (-π / 2 : ℝ)) :
p₁ ≠ p₂ :=
left_ne_of_oangle_ne_zero (h.symm ▸ Real.Angle.neg_pi_div_two_ne_zero : ∡ p₁ p₂ p₃ ≠ 0)
#align euclidean_geometry.left_ne_of_oangle_eq_neg_pi_div_two EuclideanGeometry.left_ne_of_oangle_eq_neg_pi_div_two
theorem right_ne_of_oangle_eq_neg_pi_div_two {p₁ p₂ p₃ : P} (h : ∡ p₁ p₂ p₃ = (-π / 2 : ℝ)) :
p₃ ≠ p₂ :=
right_ne_of_oangle_ne_zero (h.symm ▸ Real.Angle.neg_pi_div_two_ne_zero : ∡ p₁ p₂ p₃ ≠ 0)
#align euclidean_geometry.right_ne_of_oangle_eq_neg_pi_div_two EuclideanGeometry.right_ne_of_oangle_eq_neg_pi_div_two
theorem left_ne_right_of_oangle_eq_neg_pi_div_two {p₁ p₂ p₃ : P} (h : ∡ p₁ p₂ p₃ = (-π / 2 : ℝ)) :
p₁ ≠ p₃ :=
left_ne_right_of_oangle_ne_zero (h.symm ▸ Real.Angle.neg_pi_div_two_ne_zero : ∡ p₁ p₂ p₃ ≠ 0)
#align euclidean_geometry.left_ne_right_of_oangle_eq_neg_pi_div_two EuclideanGeometry.left_ne_right_of_oangle_eq_neg_pi_div_two
theorem left_ne_of_oangle_sign_ne_zero {p₁ p₂ p₃ : P} (h : (∡ p₁ p₂ p₃).sign ≠ 0) : p₁ ≠ p₂ :=
left_ne_of_oangle_ne_zero (Real.Angle.sign_ne_zero_iff.1 h).1
#align euclidean_geometry.left_ne_of_oangle_sign_ne_zero EuclideanGeometry.left_ne_of_oangle_sign_ne_zero
theorem right_ne_of_oangle_sign_ne_zero {p₁ p₂ p₃ : P} (h : (∡ p₁ p₂ p₃).sign ≠ 0) : p₃ ≠ p₂ :=
right_ne_of_oangle_ne_zero (Real.Angle.sign_ne_zero_iff.1 h).1
#align euclidean_geometry.right_ne_of_oangle_sign_ne_zero EuclideanGeometry.right_ne_of_oangle_sign_ne_zero
theorem left_ne_right_of_oangle_sign_ne_zero {p₁ p₂ p₃ : P} (h : (∡ p₁ p₂ p₃).sign ≠ 0) : p₁ ≠ p₃ :=
left_ne_right_of_oangle_ne_zero (Real.Angle.sign_ne_zero_iff.1 h).1
#align euclidean_geometry.left_ne_right_of_oangle_sign_ne_zero EuclideanGeometry.left_ne_right_of_oangle_sign_ne_zero
theorem left_ne_of_oangle_sign_eq_one {p₁ p₂ p₃ : P} (h : (∡ p₁ p₂ p₃).sign = 1) : p₁ ≠ p₂ :=
left_ne_of_oangle_sign_ne_zero (h.symm ▸ by decide : (∡ p₁ p₂ p₃).sign ≠ 0)
#align euclidean_geometry.left_ne_of_oangle_sign_eq_one EuclideanGeometry.left_ne_of_oangle_sign_eq_one
theorem right_ne_of_oangle_sign_eq_one {p₁ p₂ p₃ : P} (h : (∡ p₁ p₂ p₃).sign = 1) : p₃ ≠ p₂ :=
right_ne_of_oangle_sign_ne_zero (h.symm ▸ by decide : (∡ p₁ p₂ p₃).sign ≠ 0)
#align euclidean_geometry.right_ne_of_oangle_sign_eq_one EuclideanGeometry.right_ne_of_oangle_sign_eq_one
theorem left_ne_right_of_oangle_sign_eq_one {p₁ p₂ p₃ : P} (h : (∡ p₁ p₂ p₃).sign = 1) : p₁ ≠ p₃ :=
left_ne_right_of_oangle_sign_ne_zero (h.symm ▸ by decide : (∡ p₁ p₂ p₃).sign ≠ 0)
#align euclidean_geometry.left_ne_right_of_oangle_sign_eq_one EuclideanGeometry.left_ne_right_of_oangle_sign_eq_one
theorem left_ne_of_oangle_sign_eq_neg_one {p₁ p₂ p₃ : P} (h : (∡ p₁ p₂ p₃).sign = -1) : p₁ ≠ p₂ :=
left_ne_of_oangle_sign_ne_zero (h.symm ▸ by decide : (∡ p₁ p₂ p₃).sign ≠ 0)
#align euclidean_geometry.left_ne_of_oangle_sign_eq_neg_one EuclideanGeometry.left_ne_of_oangle_sign_eq_neg_one
theorem right_ne_of_oangle_sign_eq_neg_one {p₁ p₂ p₃ : P} (h : (∡ p₁ p₂ p₃).sign = -1) : p₃ ≠ p₂ :=
right_ne_of_oangle_sign_ne_zero (h.symm ▸ by decide : (∡ p₁ p₂ p₃).sign ≠ 0)
#align euclidean_geometry.right_ne_of_oangle_sign_eq_neg_one EuclideanGeometry.right_ne_of_oangle_sign_eq_neg_one
theorem left_ne_right_of_oangle_sign_eq_neg_one {p₁ p₂ p₃ : P} (h : (∡ p₁ p₂ p₃).sign = -1) :
p₁ ≠ p₃ :=
left_ne_right_of_oangle_sign_ne_zero (h.symm ▸ by decide : (∡ p₁ p₂ p₃).sign ≠ 0)
#align euclidean_geometry.left_ne_right_of_oangle_sign_eq_neg_one EuclideanGeometry.left_ne_right_of_oangle_sign_eq_neg_one
theorem oangle_rev (p₁ p₂ p₃ : P) : ∡ p₃ p₂ p₁ = -∡ p₁ p₂ p₃ :=
o.oangle_rev _ _
#align euclidean_geometry.oangle_rev EuclideanGeometry.oangle_rev
@[simp]
theorem oangle_add_oangle_rev (p₁ p₂ p₃ : P) : ∡ p₁ p₂ p₃ + ∡ p₃ p₂ p₁ = 0 :=
o.oangle_add_oangle_rev _ _
#align euclidean_geometry.oangle_add_oangle_rev EuclideanGeometry.oangle_add_oangle_rev
theorem oangle_eq_zero_iff_oangle_rev_eq_zero {p₁ p₂ p₃ : P} : ∡ p₁ p₂ p₃ = 0 ↔ ∡ p₃ p₂ p₁ = 0 :=
o.oangle_eq_zero_iff_oangle_rev_eq_zero
#align euclidean_geometry.oangle_eq_zero_iff_oangle_rev_eq_zero EuclideanGeometry.oangle_eq_zero_iff_oangle_rev_eq_zero
theorem oangle_eq_pi_iff_oangle_rev_eq_pi {p₁ p₂ p₃ : P} : ∡ p₁ p₂ p₃ = π ↔ ∡ p₃ p₂ p₁ = π :=
o.oangle_eq_pi_iff_oangle_rev_eq_pi
#align euclidean_geometry.oangle_eq_pi_iff_oangle_rev_eq_pi EuclideanGeometry.oangle_eq_pi_iff_oangle_rev_eq_pi
| Mathlib/Geometry/Euclidean/Angle/Oriented/Affine.lean | 218 | 225 | theorem oangle_ne_zero_and_ne_pi_iff_affineIndependent {p₁ p₂ p₃ : P} :
∡ p₁ p₂ p₃ ≠ 0 ∧ ∡ p₁ p₂ p₃ ≠ π ↔ AffineIndependent ℝ ![p₁, p₂, p₃] := by |
rw [oangle, o.oangle_ne_zero_and_ne_pi_iff_linearIndependent,
affineIndependent_iff_linearIndependent_vsub ℝ _ (1 : Fin 3), ←
linearIndependent_equiv (finSuccAboveEquiv (1 : Fin 3)).toEquiv]
convert Iff.rfl
ext i
fin_cases i <;> rfl
|
import Mathlib.Analysis.Calculus.Deriv.Basic
import Mathlib.Analysis.Calculus.FDeriv.Comp
import Mathlib.Analysis.Calculus.FDeriv.RestrictScalars
#align_import analysis.calculus.deriv.comp from "leanprover-community/mathlib"@"3bce8d800a6f2b8f63fe1e588fd76a9ff4adcebe"
universe u v w
open scoped Classical
open Topology Filter ENNReal
open Filter Asymptotics Set
open ContinuousLinearMap (smulRight smulRight_one_eq_iff)
variable {𝕜 : Type u} [NontriviallyNormedField 𝕜]
variable {F : Type v} [NormedAddCommGroup F] [NormedSpace 𝕜 F]
variable {E : Type w} [NormedAddCommGroup E] [NormedSpace 𝕜 E]
variable {f f₀ f₁ g : 𝕜 → F}
variable {f' f₀' f₁' g' : F}
variable {x : 𝕜}
variable {s t : Set 𝕜}
variable {L L₁ L₂ : Filter 𝕜}
section Composition
variable {𝕜' : Type*} [NontriviallyNormedField 𝕜'] [NormedAlgebra 𝕜 𝕜'] [NormedSpace 𝕜' F]
[IsScalarTower 𝕜 𝕜' F] {s' t' : Set 𝕜'} {h : 𝕜 → 𝕜'} {h₁ : 𝕜 → 𝕜} {h₂ : 𝕜' → 𝕜'} {h' h₂' : 𝕜'}
{h₁' : 𝕜} {g₁ : 𝕜' → F} {g₁' : F} {L' : Filter 𝕜'} {y : 𝕜'} (x)
theorem HasDerivAtFilter.scomp (hg : HasDerivAtFilter g₁ g₁' (h x) L')
(hh : HasDerivAtFilter h h' x L) (hL : Tendsto h L L') :
HasDerivAtFilter (g₁ ∘ h) (h' • g₁') x L := by
simpa using ((hg.restrictScalars 𝕜).comp x hh hL).hasDerivAtFilter
#align has_deriv_at_filter.scomp HasDerivAtFilter.scomp
theorem HasDerivAtFilter.scomp_of_eq (hg : HasDerivAtFilter g₁ g₁' y L')
(hh : HasDerivAtFilter h h' x L) (hy : y = h x) (hL : Tendsto h L L') :
HasDerivAtFilter (g₁ ∘ h) (h' • g₁') x L := by
rw [hy] at hg; exact hg.scomp x hh hL
theorem HasDerivWithinAt.scomp_hasDerivAt (hg : HasDerivWithinAt g₁ g₁' s' (h x))
(hh : HasDerivAt h h' x) (hs : ∀ x, h x ∈ s') : HasDerivAt (g₁ ∘ h) (h' • g₁') x :=
hg.scomp x hh <| tendsto_inf.2 ⟨hh.continuousAt, tendsto_principal.2 <| eventually_of_forall hs⟩
#align has_deriv_within_at.scomp_has_deriv_at HasDerivWithinAt.scomp_hasDerivAt
theorem HasDerivWithinAt.scomp_hasDerivAt_of_eq (hg : HasDerivWithinAt g₁ g₁' s' y)
(hh : HasDerivAt h h' x) (hs : ∀ x, h x ∈ s') (hy : y = h x) :
HasDerivAt (g₁ ∘ h) (h' • g₁') x := by
rw [hy] at hg; exact hg.scomp_hasDerivAt x hh hs
nonrec theorem HasDerivWithinAt.scomp (hg : HasDerivWithinAt g₁ g₁' t' (h x))
(hh : HasDerivWithinAt h h' s x) (hst : MapsTo h s t') :
HasDerivWithinAt (g₁ ∘ h) (h' • g₁') s x :=
hg.scomp x hh <| hh.continuousWithinAt.tendsto_nhdsWithin hst
#align has_deriv_within_at.scomp HasDerivWithinAt.scomp
| Mathlib/Analysis/Calculus/Deriv/Comp.lean | 101 | 104 | theorem HasDerivWithinAt.scomp_of_eq (hg : HasDerivWithinAt g₁ g₁' t' y)
(hh : HasDerivWithinAt h h' s x) (hst : MapsTo h s t') (hy : y = h x) :
HasDerivWithinAt (g₁ ∘ h) (h' • g₁') s x := by |
rw [hy] at hg; exact hg.scomp x hh hst
|
import Mathlib.Data.Finset.Lattice
#align_import combinatorics.set_family.compression.down from "leanprover-community/mathlib"@"9003f28797c0664a49e4179487267c494477d853"
variable {α : Type*} [DecidableEq α] {𝒜 ℬ : Finset (Finset α)} {s : Finset α} {a : α}
namespace Finset
def nonMemberSubfamily (a : α) (𝒜 : Finset (Finset α)) : Finset (Finset α) :=
𝒜.filter fun s => a ∉ s
#align finset.non_member_subfamily Finset.nonMemberSubfamily
def memberSubfamily (a : α) (𝒜 : Finset (Finset α)) : Finset (Finset α) :=
(𝒜.filter fun s => a ∈ s).image fun s => erase s a
#align finset.member_subfamily Finset.memberSubfamily
@[simp]
theorem mem_nonMemberSubfamily : s ∈ 𝒜.nonMemberSubfamily a ↔ s ∈ 𝒜 ∧ a ∉ s := by
simp [nonMemberSubfamily]
#align finset.mem_non_member_subfamily Finset.mem_nonMemberSubfamily
@[simp]
theorem mem_memberSubfamily : s ∈ 𝒜.memberSubfamily a ↔ insert a s ∈ 𝒜 ∧ a ∉ s := by
simp_rw [memberSubfamily, mem_image, mem_filter]
refine ⟨?_, fun h => ⟨insert a s, ⟨h.1, by simp⟩, erase_insert h.2⟩⟩
rintro ⟨s, ⟨hs1, hs2⟩, rfl⟩
rw [insert_erase hs2]
exact ⟨hs1, not_mem_erase _ _⟩
#align finset.mem_member_subfamily Finset.mem_memberSubfamily
theorem nonMemberSubfamily_inter (a : α) (𝒜 ℬ : Finset (Finset α)) :
(𝒜 ∩ ℬ).nonMemberSubfamily a = 𝒜.nonMemberSubfamily a ∩ ℬ.nonMemberSubfamily a :=
filter_inter_distrib _ _ _
#align finset.non_member_subfamily_inter Finset.nonMemberSubfamily_inter
theorem memberSubfamily_inter (a : α) (𝒜 ℬ : Finset (Finset α)) :
(𝒜 ∩ ℬ).memberSubfamily a = 𝒜.memberSubfamily a ∩ ℬ.memberSubfamily a := by
unfold memberSubfamily
rw [filter_inter_distrib, image_inter_of_injOn _ _ ((erase_injOn' _).mono _)]
simp
#align finset.member_subfamily_inter Finset.memberSubfamily_inter
theorem nonMemberSubfamily_union (a : α) (𝒜 ℬ : Finset (Finset α)) :
(𝒜 ∪ ℬ).nonMemberSubfamily a = 𝒜.nonMemberSubfamily a ∪ ℬ.nonMemberSubfamily a :=
filter_union _ _ _
#align finset.non_member_subfamily_union Finset.nonMemberSubfamily_union
theorem memberSubfamily_union (a : α) (𝒜 ℬ : Finset (Finset α)) :
(𝒜 ∪ ℬ).memberSubfamily a = 𝒜.memberSubfamily a ∪ ℬ.memberSubfamily a := by
simp_rw [memberSubfamily, filter_union, image_union]
#align finset.member_subfamily_union Finset.memberSubfamily_union
| Mathlib/Combinatorics/SetFamily/Compression/Down.lean | 91 | 96 | theorem card_memberSubfamily_add_card_nonMemberSubfamily (a : α) (𝒜 : Finset (Finset α)) :
(𝒜.memberSubfamily a).card + (𝒜.nonMemberSubfamily a).card = 𝒜.card := by |
rw [memberSubfamily, nonMemberSubfamily, card_image_of_injOn]
· conv_rhs => rw [← filter_card_add_filter_neg_card_eq_card (fun s => (a ∈ s))]
· apply (erase_injOn' _).mono
simp
|
import Mathlib.Analysis.Calculus.Deriv.Inv
import Mathlib.Analysis.NormedSpace.BallAction
import Mathlib.Analysis.SpecialFunctions.ExpDeriv
import Mathlib.Analysis.InnerProductSpace.Calculus
import Mathlib.Analysis.InnerProductSpace.PiL2
import Mathlib.Geometry.Manifold.Algebra.LieGroup
import Mathlib.Geometry.Manifold.Instances.Real
import Mathlib.Geometry.Manifold.MFDeriv.Basic
#align_import geometry.manifold.instances.sphere from "leanprover-community/mathlib"@"0dc4079202c28226b2841a51eb6d3cc2135bb80f"
variable {E : Type*} [NormedAddCommGroup E] [InnerProductSpace ℝ E]
noncomputable section
open Metric FiniteDimensional Function
open scoped Manifold
section StereographicProjection
variable (v : E)
def stereoToFun (x : E) : (ℝ ∙ v)ᗮ :=
(2 / ((1 : ℝ) - innerSL ℝ v x)) • orthogonalProjection (ℝ ∙ v)ᗮ x
#align stereo_to_fun stereoToFun
variable {v}
@[simp]
theorem stereoToFun_apply (x : E) :
stereoToFun v x = (2 / ((1 : ℝ) - innerSL ℝ v x)) • orthogonalProjection (ℝ ∙ v)ᗮ x :=
rfl
#align stereo_to_fun_apply stereoToFun_apply
theorem contDiffOn_stereoToFun :
ContDiffOn ℝ ⊤ (stereoToFun v) {x : E | innerSL _ v x ≠ (1 : ℝ)} := by
refine ContDiffOn.smul ?_ (orthogonalProjection (ℝ ∙ v)ᗮ).contDiff.contDiffOn
refine contDiff_const.contDiffOn.div ?_ ?_
· exact (contDiff_const.sub (innerSL ℝ v).contDiff).contDiffOn
· intro x h h'
exact h (sub_eq_zero.mp h').symm
#align cont_diff_on_stereo_to_fun contDiffOn_stereoToFun
theorem continuousOn_stereoToFun :
ContinuousOn (stereoToFun v) {x : E | innerSL _ v x ≠ (1 : ℝ)} :=
contDiffOn_stereoToFun.continuousOn
#align continuous_on_stereo_to_fun continuousOn_stereoToFun
variable (v)
def stereoInvFunAux (w : E) : E :=
(‖w‖ ^ 2 + 4)⁻¹ • ((4 : ℝ) • w + (‖w‖ ^ 2 - 4) • v)
#align stereo_inv_fun_aux stereoInvFunAux
variable {v}
@[simp]
theorem stereoInvFunAux_apply (w : E) :
stereoInvFunAux v w = (‖w‖ ^ 2 + 4)⁻¹ • ((4 : ℝ) • w + (‖w‖ ^ 2 - 4) • v) :=
rfl
#align stereo_inv_fun_aux_apply stereoInvFunAux_apply
theorem stereoInvFunAux_mem (hv : ‖v‖ = 1) {w : E} (hw : w ∈ (ℝ ∙ v)ᗮ) :
stereoInvFunAux v w ∈ sphere (0 : E) 1 := by
have h₁ : (0 : ℝ) < ‖w‖ ^ 2 + 4 := by positivity
suffices ‖(4 : ℝ) • w + (‖w‖ ^ 2 - 4) • v‖ = ‖w‖ ^ 2 + 4 by
simp only [mem_sphere_zero_iff_norm, norm_smul, Real.norm_eq_abs, abs_inv, this,
abs_of_pos h₁, stereoInvFunAux_apply, inv_mul_cancel h₁.ne']
suffices ‖(4 : ℝ) • w + (‖w‖ ^ 2 - 4) • v‖ ^ 2 = (‖w‖ ^ 2 + 4) ^ 2 by
simpa [sq_eq_sq_iff_abs_eq_abs, abs_of_pos h₁] using this
rw [Submodule.mem_orthogonal_singleton_iff_inner_left] at hw
simp [norm_add_sq_real, norm_smul, inner_smul_left, inner_smul_right, hw, mul_pow,
Real.norm_eq_abs, hv]
ring
#align stereo_inv_fun_aux_mem stereoInvFunAux_mem
theorem hasFDerivAt_stereoInvFunAux (v : E) :
HasFDerivAt (stereoInvFunAux v) (ContinuousLinearMap.id ℝ E) 0 := by
have h₀ : HasFDerivAt (fun w : E => ‖w‖ ^ 2) (0 : E →L[ℝ] ℝ) 0 := by
convert (hasStrictFDerivAt_norm_sq (0 : E)).hasFDerivAt
simp
have h₁ : HasFDerivAt (fun w : E => (‖w‖ ^ 2 + 4)⁻¹) (0 : E →L[ℝ] ℝ) 0 := by
convert (hasFDerivAt_inv _).comp _ (h₀.add (hasFDerivAt_const 4 0)) <;> simp
have h₂ : HasFDerivAt (fun w => (4 : ℝ) • w + (‖w‖ ^ 2 - 4) • v)
((4 : ℝ) • ContinuousLinearMap.id ℝ E) 0 := by
convert ((hasFDerivAt_const (4 : ℝ) 0).smul (hasFDerivAt_id 0)).add
((h₀.sub (hasFDerivAt_const (4 : ℝ) 0)).smul (hasFDerivAt_const v 0)) using 1
ext w
simp
convert h₁.smul h₂ using 1
ext w
simp
#align has_fderiv_at_stereo_inv_fun_aux hasFDerivAt_stereoInvFunAux
theorem hasFDerivAt_stereoInvFunAux_comp_coe (v : E) :
HasFDerivAt (stereoInvFunAux v ∘ ((↑) : (ℝ ∙ v)ᗮ → E)) (ℝ ∙ v)ᗮ.subtypeL 0 := by
have : HasFDerivAt (stereoInvFunAux v) (ContinuousLinearMap.id ℝ E) ((ℝ ∙ v)ᗮ.subtypeL 0) :=
hasFDerivAt_stereoInvFunAux v
convert this.comp (0 : (ℝ ∙ v)ᗮ) (by apply ContinuousLinearMap.hasFDerivAt)
#align has_fderiv_at_stereo_inv_fun_aux_comp_coe hasFDerivAt_stereoInvFunAux_comp_coe
theorem contDiff_stereoInvFunAux : ContDiff ℝ ⊤ (stereoInvFunAux v) := by
have h₀ : ContDiff ℝ ⊤ fun w : E => ‖w‖ ^ 2 := contDiff_norm_sq ℝ
have h₁ : ContDiff ℝ ⊤ fun w : E => (‖w‖ ^ 2 + 4)⁻¹ := by
refine (h₀.add contDiff_const).inv ?_
intro x
nlinarith
have h₂ : ContDiff ℝ ⊤ fun w => (4 : ℝ) • w + (‖w‖ ^ 2 - 4) • v := by
refine (contDiff_const.smul contDiff_id).add ?_
exact (h₀.sub contDiff_const).smul contDiff_const
exact h₁.smul h₂
#align cont_diff_stereo_inv_fun_aux contDiff_stereoInvFunAux
def stereoInvFun (hv : ‖v‖ = 1) (w : (ℝ ∙ v)ᗮ) : sphere (0 : E) 1 :=
⟨stereoInvFunAux v (w : E), stereoInvFunAux_mem hv w.2⟩
#align stereo_inv_fun stereoInvFun
@[simp]
theorem stereoInvFun_apply (hv : ‖v‖ = 1) (w : (ℝ ∙ v)ᗮ) :
(stereoInvFun hv w : E) = (‖w‖ ^ 2 + 4)⁻¹ • ((4 : ℝ) • w + (‖w‖ ^ 2 - 4) • v) :=
rfl
#align stereo_inv_fun_apply stereoInvFun_apply
theorem stereoInvFun_ne_north_pole (hv : ‖v‖ = 1) (w : (ℝ ∙ v)ᗮ) :
stereoInvFun hv w ≠ (⟨v, by simp [hv]⟩ : sphere (0 : E) 1) := by
refine Subtype.coe_ne_coe.1 ?_
rw [← inner_lt_one_iff_real_of_norm_one _ hv]
· have hw : ⟪v, w⟫_ℝ = 0 := Submodule.mem_orthogonal_singleton_iff_inner_right.mp w.2
have hw' : (‖(w : E)‖ ^ 2 + 4)⁻¹ * (‖(w : E)‖ ^ 2 - 4) < 1 := by
refine (inv_mul_lt_iff' ?_).mpr ?_
· nlinarith
linarith
simpa [real_inner_comm, inner_add_right, inner_smul_right, real_inner_self_eq_norm_mul_norm, hw,
hv] using hw'
· simpa using stereoInvFunAux_mem hv w.2
#align stereo_inv_fun_ne_north_pole stereoInvFun_ne_north_pole
theorem continuous_stereoInvFun (hv : ‖v‖ = 1) : Continuous (stereoInvFun hv) :=
continuous_induced_rng.2 (contDiff_stereoInvFunAux.continuous.comp continuous_subtype_val)
#align continuous_stereo_inv_fun continuous_stereoInvFun
theorem stereo_left_inv (hv : ‖v‖ = 1) {x : sphere (0 : E) 1} (hx : (x : E) ≠ v) :
stereoInvFun hv (stereoToFun v x) = x := by
ext
simp only [stereoToFun_apply, stereoInvFun_apply, smul_add]
-- name two frequently-occuring quantities and write down their basic properties
set a : ℝ := innerSL _ v x
set y := orthogonalProjection (ℝ ∙ v)ᗮ x
have split : ↑x = a • v + ↑y := by
convert (orthogonalProjection_add_orthogonalProjection_orthogonal (ℝ ∙ v) x).symm
exact (orthogonalProjection_unit_singleton ℝ hv x).symm
have hvy : ⟪v, y⟫_ℝ = 0 := Submodule.mem_orthogonal_singleton_iff_inner_right.mp y.2
have pythag : 1 = a ^ 2 + ‖y‖ ^ 2 := by
have hvy' : ⟪a • v, y⟫_ℝ = 0 := by simp only [inner_smul_left, hvy, mul_zero]
convert norm_add_sq_eq_norm_sq_add_norm_sq_of_inner_eq_zero _ _ hvy' using 2
· simp [← split]
· simp [norm_smul, hv, ← sq, sq_abs]
· exact sq _
-- two facts which will be helpful for clearing denominators in the main calculation
have ha : 1 - a ≠ 0 := by
have : a < 1 := (inner_lt_one_iff_real_of_norm_one hv (by simp)).mpr hx.symm
linarith
-- the core of the problem is these two algebraic identities:
have h₁ : (2 ^ 2 / (1 - a) ^ 2 * ‖y‖ ^ 2 + 4)⁻¹ * 4 * (2 / (1 - a)) = 1 := by
field_simp; simp only [Submodule.coe_norm] at *; nlinarith
have h₂ : (2 ^ 2 / (1 - a) ^ 2 * ‖y‖ ^ 2 + 4)⁻¹ * (2 ^ 2 / (1 - a) ^ 2 * ‖y‖ ^ 2 - 4) = a := by
field_simp
transitivity (1 - a) ^ 2 * (a * (2 ^ 2 * ‖y‖ ^ 2 + 4 * (1 - a) ^ 2))
· congr
simp only [Submodule.coe_norm] at *
nlinarith
ring!
convert
congr_arg₂ Add.add (congr_arg (fun t => t • (y : E)) h₁) (congr_arg (fun t => t • v) h₂) using 1
· simp [a, inner_add_right, inner_smul_right, hvy, real_inner_self_eq_norm_mul_norm, hv, mul_smul,
mul_pow, Real.norm_eq_abs, sq_abs, norm_smul]
-- Porting note: used to be simp only [split, add_comm] but get maxRec errors
rw [split, add_comm]
ac_rfl
-- Porting note: this branch did not exit in ml3
· rw [split, add_comm]
congr!
dsimp
rw [one_smul]
#align stereo_left_inv stereo_left_inv
| Mathlib/Geometry/Manifold/Instances/Sphere.lean | 257 | 268 | theorem stereo_right_inv (hv : ‖v‖ = 1) (w : (ℝ ∙ v)ᗮ) : stereoToFun v (stereoInvFun hv w) = w := by |
have : 2 / (1 - (‖(w : E)‖ ^ 2 + 4)⁻¹ * (‖(w : E)‖ ^ 2 - 4)) * (‖(w : E)‖ ^ 2 + 4)⁻¹ * 4 = 1 := by
field_simp; ring
convert congr_arg (· • w) this
· have h₁ : orthogonalProjection (ℝ ∙ v)ᗮ v = 0 :=
orthogonalProjection_orthogonalComplement_singleton_eq_zero v
-- Porting note: was innerSL _ and now just inner
have h₃ : inner v w = (0 : ℝ) := Submodule.mem_orthogonal_singleton_iff_inner_right.mp w.2
-- Porting note: was innerSL _ and now just inner
have h₄ : inner v v = (1 : ℝ) := by simp [real_inner_self_eq_norm_mul_norm, hv]
simp [h₁, h₃, h₄, ContinuousLinearMap.map_add, ContinuousLinearMap.map_smul, mul_smul]
· simp
|
import Mathlib.MeasureTheory.Constructions.BorelSpace.Order
#align_import measure_theory.function.floor from "leanprover-community/mathlib"@"bf6a01357ff5684b1ebcd0f1a13be314fc82c0bf"
open Set
section FloorRing
variable {α R : Type*} [MeasurableSpace α] [LinearOrderedRing R] [FloorRing R] [TopologicalSpace R]
[OrderTopology R] [MeasurableSpace R]
theorem Int.measurable_floor [OpensMeasurableSpace R] : Measurable (Int.floor : R → ℤ) :=
measurable_to_countable fun x => by
simpa only [Int.preimage_floor_singleton] using measurableSet_Ico
#align int.measurable_floor Int.measurable_floor
@[measurability]
theorem Measurable.floor [OpensMeasurableSpace R] {f : α → R} (hf : Measurable f) :
Measurable fun x => ⌊f x⌋ :=
Int.measurable_floor.comp hf
#align measurable.floor Measurable.floor
theorem Int.measurable_ceil [OpensMeasurableSpace R] : Measurable (Int.ceil : R → ℤ) :=
measurable_to_countable fun x => by
simpa only [Int.preimage_ceil_singleton] using measurableSet_Ioc
#align int.measurable_ceil Int.measurable_ceil
@[measurability]
theorem Measurable.ceil [OpensMeasurableSpace R] {f : α → R} (hf : Measurable f) :
Measurable fun x => ⌈f x⌉ :=
Int.measurable_ceil.comp hf
#align measurable.ceil Measurable.ceil
| Mathlib/MeasureTheory/Function/Floor.lean | 47 | 50 | theorem measurable_fract [BorelSpace R] : Measurable (Int.fract : R → R) := by |
intro s hs
rw [Int.preimage_fract]
exact MeasurableSet.iUnion fun z => measurable_id.sub_const _ (hs.inter measurableSet_Ico)
|
import Mathlib.Order.ConditionallyCompleteLattice.Finset
import Mathlib.Order.Interval.Finset.Nat
#align_import data.nat.lattice from "leanprover-community/mathlib"@"52fa514ec337dd970d71d8de8d0fd68b455a1e54"
assert_not_exists MonoidWithZero
open Set
namespace Nat
open scoped Classical
noncomputable instance : InfSet ℕ :=
⟨fun s ↦ if h : ∃ n, n ∈ s then @Nat.find (fun n ↦ n ∈ s) _ h else 0⟩
noncomputable instance : SupSet ℕ :=
⟨fun s ↦ if h : ∃ n, ∀ a ∈ s, a ≤ n then @Nat.find (fun n ↦ ∀ a ∈ s, a ≤ n) _ h else 0⟩
theorem sInf_def {s : Set ℕ} (h : s.Nonempty) : sInf s = @Nat.find (fun n ↦ n ∈ s) _ h :=
dif_pos _
#align nat.Inf_def Nat.sInf_def
theorem sSup_def {s : Set ℕ} (h : ∃ n, ∀ a ∈ s, a ≤ n) :
sSup s = @Nat.find (fun n ↦ ∀ a ∈ s, a ≤ n) _ h :=
dif_pos _
#align nat.Sup_def Nat.sSup_def
theorem _root_.Set.Infinite.Nat.sSup_eq_zero {s : Set ℕ} (h : s.Infinite) : sSup s = 0 :=
dif_neg fun ⟨n, hn⟩ ↦
let ⟨k, hks, hk⟩ := h.exists_gt n
(hn k hks).not_lt hk
#align set.infinite.nat.Sup_eq_zero Set.Infinite.Nat.sSup_eq_zero
@[simp]
theorem sInf_eq_zero {s : Set ℕ} : sInf s = 0 ↔ 0 ∈ s ∨ s = ∅ := by
cases eq_empty_or_nonempty s with
| inl h => subst h
simp only [or_true_iff, eq_self_iff_true, iff_true_iff, iInf, InfSet.sInf,
mem_empty_iff_false, exists_false, dif_neg, not_false_iff]
| inr h => simp only [h.ne_empty, or_false_iff, Nat.sInf_def, h, Nat.find_eq_zero]
#align nat.Inf_eq_zero Nat.sInf_eq_zero
@[simp]
theorem sInf_empty : sInf ∅ = 0 := by
rw [sInf_eq_zero]
right
rfl
#align nat.Inf_empty Nat.sInf_empty
@[simp]
theorem iInf_of_empty {ι : Sort*} [IsEmpty ι] (f : ι → ℕ) : iInf f = 0 := by
rw [iInf_of_isEmpty, sInf_empty]
#align nat.infi_of_empty Nat.iInf_of_empty
@[simp]
lemma iInf_const_zero {ι : Sort*} : ⨅ i : ι, 0 = 0 :=
(isEmpty_or_nonempty ι).elim (fun h ↦ by simp) fun h ↦ sInf_eq_zero.2 <| by simp
theorem sInf_mem {s : Set ℕ} (h : s.Nonempty) : sInf s ∈ s := by
rw [Nat.sInf_def h]
exact Nat.find_spec h
#align nat.Inf_mem Nat.sInf_mem
theorem not_mem_of_lt_sInf {s : Set ℕ} {m : ℕ} (hm : m < sInf s) : m ∉ s := by
cases eq_empty_or_nonempty s with
| inl h => subst h; apply not_mem_empty
| inr h => rw [Nat.sInf_def h] at hm; exact Nat.find_min h hm
#align nat.not_mem_of_lt_Inf Nat.not_mem_of_lt_sInf
protected theorem sInf_le {s : Set ℕ} {m : ℕ} (hm : m ∈ s) : sInf s ≤ m := by
rw [Nat.sInf_def ⟨m, hm⟩]
exact Nat.find_min' ⟨m, hm⟩ hm
#align nat.Inf_le Nat.sInf_le
theorem nonempty_of_pos_sInf {s : Set ℕ} (h : 0 < sInf s) : s.Nonempty := by
by_contra contra
rw [Set.not_nonempty_iff_eq_empty] at contra
have h' : sInf s ≠ 0 := ne_of_gt h
apply h'
rw [Nat.sInf_eq_zero]
right
assumption
#align nat.nonempty_of_pos_Inf Nat.nonempty_of_pos_sInf
theorem nonempty_of_sInf_eq_succ {s : Set ℕ} {k : ℕ} (h : sInf s = k + 1) : s.Nonempty :=
nonempty_of_pos_sInf (h.symm ▸ succ_pos k : sInf s > 0)
#align nat.nonempty_of_Inf_eq_succ Nat.nonempty_of_sInf_eq_succ
theorem eq_Ici_of_nonempty_of_upward_closed {s : Set ℕ} (hs : s.Nonempty)
(hs' : ∀ k₁ k₂ : ℕ, k₁ ≤ k₂ → k₁ ∈ s → k₂ ∈ s) : s = Ici (sInf s) :=
ext fun n ↦ ⟨fun H ↦ Nat.sInf_le H, fun H ↦ hs' (sInf s) n H (sInf_mem hs)⟩
#align nat.eq_Ici_of_nonempty_of_upward_closed Nat.eq_Ici_of_nonempty_of_upward_closed
theorem sInf_upward_closed_eq_succ_iff {s : Set ℕ} (hs : ∀ k₁ k₂ : ℕ, k₁ ≤ k₂ → k₁ ∈ s → k₂ ∈ s)
(k : ℕ) : sInf s = k + 1 ↔ k + 1 ∈ s ∧ k ∉ s := by
constructor
· intro H
rw [eq_Ici_of_nonempty_of_upward_closed (nonempty_of_sInf_eq_succ _) hs, H, mem_Ici, mem_Ici]
· exact ⟨le_rfl, k.not_succ_le_self⟩;
· exact k
· assumption
· rintro ⟨H, H'⟩
rw [sInf_def (⟨_, H⟩ : s.Nonempty), find_eq_iff]
exact ⟨H, fun n hnk hns ↦ H' <| hs n k (Nat.lt_succ_iff.mp hnk) hns⟩
#align nat.Inf_upward_closed_eq_succ_iff Nat.sInf_upward_closed_eq_succ_iff
instance : Lattice ℕ :=
LinearOrder.toLattice
noncomputable instance : ConditionallyCompleteLinearOrderBot ℕ :=
{ (inferInstance : OrderBot ℕ), (LinearOrder.toLattice : Lattice ℕ),
(inferInstance : LinearOrder ℕ) with
-- sup := sSup -- Porting note: removed, unnecessary?
-- inf := sInf -- Porting note: removed, unnecessary?
le_csSup := fun s a hb ha ↦ by rw [sSup_def hb]; revert a ha; exact @Nat.find_spec _ _ hb
csSup_le := fun s a _ ha ↦ by rw [sSup_def ⟨a, ha⟩]; exact Nat.find_min' _ ha
le_csInf := fun s a hs hb ↦ by
rw [sInf_def hs]; exact hb (@Nat.find_spec (fun n ↦ n ∈ s) _ _)
csInf_le := fun s a _ ha ↦ by rw [sInf_def ⟨a, ha⟩]; exact Nat.find_min' _ ha
csSup_empty := by
simp only [sSup_def, Set.mem_empty_iff_false, forall_const, forall_prop_of_false,
not_false_iff, exists_const]
apply bot_unique (Nat.find_min' _ _)
trivial
csSup_of_not_bddAbove := by
intro s hs
simp only [mem_univ, forall_true_left, sSup,
mem_empty_iff_false, IsEmpty.forall_iff, forall_const, exists_const, dite_true]
rw [dif_neg]
· exact le_antisymm (zero_le _) (find_le trivial)
· exact hs
csInf_of_not_bddBelow := fun s hs ↦ by simp at hs }
theorem sSup_mem {s : Set ℕ} (h₁ : s.Nonempty) (h₂ : BddAbove s) : sSup s ∈ s :=
let ⟨k, hk⟩ := h₂
h₁.csSup_mem ((finite_le_nat k).subset hk)
#align nat.Sup_mem Nat.sSup_mem
theorem sInf_add {n : ℕ} {p : ℕ → Prop} (hn : n ≤ sInf { m | p m }) :
sInf { m | p (m + n) } + n = sInf { m | p m } := by
obtain h | ⟨m, hm⟩ := { m | p (m + n) }.eq_empty_or_nonempty
· rw [h, Nat.sInf_empty, zero_add]
obtain hnp | hnp := hn.eq_or_lt
· exact hnp
suffices hp : p (sInf { m | p m } - n + n) from (h.subset hp).elim
rw [Nat.sub_add_cancel hn]
exact csInf_mem (nonempty_of_pos_sInf <| n.zero_le.trans_lt hnp)
· have hp : ∃ n, n ∈ { m | p m } := ⟨_, hm⟩
rw [Nat.sInf_def ⟨m, hm⟩, Nat.sInf_def hp]
rw [Nat.sInf_def hp] at hn
exact find_add hn
#align nat.Inf_add Nat.sInf_add
theorem sInf_add' {n : ℕ} {p : ℕ → Prop} (h : 0 < sInf { m | p m }) :
sInf { m | p m } + n = sInf { m | p (m - n) } := by
suffices h₁ : n ≤ sInf {m | p (m - n)} by
convert sInf_add h₁
simp_rw [Nat.add_sub_cancel_right]
obtain ⟨m, hm⟩ := nonempty_of_pos_sInf h
refine
le_csInf ⟨m + n, ?_⟩ fun b hb ↦
le_of_not_lt fun hbn ↦
ne_of_mem_of_not_mem ?_ (not_mem_of_lt_sInf h) (Nat.sub_eq_zero_of_le hbn.le)
· dsimp
rwa [Nat.add_sub_cancel_right]
· exact hb
#align nat.Inf_add' Nat.sInf_add'
section
variable {α : Type*} [CompleteLattice α]
theorem iSup_lt_succ (u : ℕ → α) (n : ℕ) : ⨆ k < n + 1, u k = (⨆ k < n, u k) ⊔ u n := by
simp [Nat.lt_succ_iff_lt_or_eq, iSup_or, iSup_sup_eq]
#align nat.supr_lt_succ Nat.iSup_lt_succ
theorem iSup_lt_succ' (u : ℕ → α) (n : ℕ) : ⨆ k < n + 1, u k = u 0 ⊔ ⨆ k < n, u (k + 1) := by
rw [← sup_iSup_nat_succ]
simp
#align nat.supr_lt_succ' Nat.iSup_lt_succ'
theorem iInf_lt_succ (u : ℕ → α) (n : ℕ) : ⨅ k < n + 1, u k = (⨅ k < n, u k) ⊓ u n :=
@iSup_lt_succ αᵒᵈ _ _ _
#align nat.infi_lt_succ Nat.iInf_lt_succ
theorem iInf_lt_succ' (u : ℕ → α) (n : ℕ) : ⨅ k < n + 1, u k = u 0 ⊓ ⨅ k < n, u (k + 1) :=
@iSup_lt_succ' αᵒᵈ _ _ _
#align nat.infi_lt_succ' Nat.iInf_lt_succ'
theorem iSup_le_succ (u : ℕ → α) (n : ℕ) : ⨆ k ≤ n + 1, u k = (⨆ k ≤ n, u k) ⊔ u (n + 1) := by
simp_rw [← Nat.lt_succ_iff, iSup_lt_succ]
| Mathlib/Data/Nat/Lattice.lean | 211 | 212 | theorem iSup_le_succ' (u : ℕ → α) (n : ℕ) : ⨆ k ≤ n + 1, u k = u 0 ⊔ ⨆ k ≤ n, u (k + 1) := by |
simp_rw [← Nat.lt_succ_iff, iSup_lt_succ']
|
import Mathlib.Algebra.Group.Equiv.Basic
import Mathlib.Data.ENat.Lattice
import Mathlib.Data.Part
import Mathlib.Tactic.NormNum
#align_import data.nat.part_enat from "leanprover-community/mathlib"@"3ff3f2d6a3118b8711063de7111a0d77a53219a8"
open Part hiding some
def PartENat : Type :=
Part ℕ
#align part_enat PartENat
namespace PartENat
@[coe]
def some : ℕ → PartENat :=
Part.some
#align part_enat.some PartENat.some
instance : Zero PartENat :=
⟨some 0⟩
instance : Inhabited PartENat :=
⟨0⟩
instance : One PartENat :=
⟨some 1⟩
instance : Add PartENat :=
⟨fun x y => ⟨x.Dom ∧ y.Dom, fun h => get x h.1 + get y h.2⟩⟩
instance (n : ℕ) : Decidable (some n).Dom :=
isTrue trivial
@[simp]
theorem dom_some (x : ℕ) : (some x).Dom :=
trivial
#align part_enat.dom_some PartENat.dom_some
instance addCommMonoid : AddCommMonoid PartENat where
add := (· + ·)
zero := 0
add_comm x y := Part.ext' and_comm fun _ _ => add_comm _ _
zero_add x := Part.ext' (true_and_iff _) fun _ _ => zero_add _
add_zero x := Part.ext' (and_true_iff _) fun _ _ => add_zero _
add_assoc x y z := Part.ext' and_assoc fun _ _ => add_assoc _ _ _
nsmul := nsmulRec
instance : AddCommMonoidWithOne PartENat :=
{ PartENat.addCommMonoid with
one := 1
natCast := some
natCast_zero := rfl
natCast_succ := fun _ => Part.ext' (true_and_iff _).symm fun _ _ => rfl }
theorem some_eq_natCast (n : ℕ) : some n = n :=
rfl
#align part_enat.some_eq_coe PartENat.some_eq_natCast
instance : CharZero PartENat where
cast_injective := Part.some_injective
theorem natCast_inj {x y : ℕ} : (x : PartENat) = y ↔ x = y :=
Nat.cast_inj
#align part_enat.coe_inj PartENat.natCast_inj
@[simp]
theorem dom_natCast (x : ℕ) : (x : PartENat).Dom :=
trivial
#align part_enat.dom_coe PartENat.dom_natCast
-- See note [no_index around OfNat.ofNat]
@[simp]
theorem dom_ofNat (x : ℕ) [x.AtLeastTwo] : (no_index (OfNat.ofNat x : PartENat)).Dom :=
trivial
@[simp]
theorem dom_zero : (0 : PartENat).Dom :=
trivial
@[simp]
theorem dom_one : (1 : PartENat).Dom :=
trivial
instance : CanLift PartENat ℕ (↑) Dom :=
⟨fun n hn => ⟨n.get hn, Part.some_get _⟩⟩
instance : LE PartENat :=
⟨fun x y => ∃ h : y.Dom → x.Dom, ∀ hy : y.Dom, x.get (h hy) ≤ y.get hy⟩
instance : Top PartENat :=
⟨none⟩
instance : Bot PartENat :=
⟨0⟩
instance : Sup PartENat :=
⟨fun x y => ⟨x.Dom ∧ y.Dom, fun h => x.get h.1 ⊔ y.get h.2⟩⟩
theorem le_def (x y : PartENat) :
x ≤ y ↔ ∃ h : y.Dom → x.Dom, ∀ hy : y.Dom, x.get (h hy) ≤ y.get hy :=
Iff.rfl
#align part_enat.le_def PartENat.le_def
@[elab_as_elim]
protected theorem casesOn' {P : PartENat → Prop} :
∀ a : PartENat, P ⊤ → (∀ n : ℕ, P (some n)) → P a :=
Part.induction_on
#align part_enat.cases_on' PartENat.casesOn'
@[elab_as_elim]
protected theorem casesOn {P : PartENat → Prop} : ∀ a : PartENat, P ⊤ → (∀ n : ℕ, P n) → P a := by
exact PartENat.casesOn'
#align part_enat.cases_on PartENat.casesOn
-- not a simp lemma as we will provide a `LinearOrderedAddCommMonoidWithTop` instance later
theorem top_add (x : PartENat) : ⊤ + x = ⊤ :=
Part.ext' (false_and_iff _) fun h => h.left.elim
#align part_enat.top_add PartENat.top_add
-- not a simp lemma as we will provide a `LinearOrderedAddCommMonoidWithTop` instance later
theorem add_top (x : PartENat) : x + ⊤ = ⊤ := by rw [add_comm, top_add]
#align part_enat.add_top PartENat.add_top
@[simp]
theorem natCast_get {x : PartENat} (h : x.Dom) : (x.get h : PartENat) = x := by
exact Part.ext' (iff_of_true trivial h) fun _ _ => rfl
#align part_enat.coe_get PartENat.natCast_get
@[simp, norm_cast]
theorem get_natCast' (x : ℕ) (h : (x : PartENat).Dom) : get (x : PartENat) h = x := by
rw [← natCast_inj, natCast_get]
#align part_enat.get_coe' PartENat.get_natCast'
theorem get_natCast {x : ℕ} : get (x : PartENat) (dom_natCast x) = x :=
get_natCast' _ _
#align part_enat.get_coe PartENat.get_natCast
theorem coe_add_get {x : ℕ} {y : PartENat} (h : ((x : PartENat) + y).Dom) :
get ((x : PartENat) + y) h = x + get y h.2 := by
rfl
#align part_enat.coe_add_get PartENat.coe_add_get
@[simp]
theorem get_add {x y : PartENat} (h : (x + y).Dom) : get (x + y) h = x.get h.1 + y.get h.2 :=
rfl
#align part_enat.get_add PartENat.get_add
@[simp]
theorem get_zero (h : (0 : PartENat).Dom) : (0 : PartENat).get h = 0 :=
rfl
#align part_enat.get_zero PartENat.get_zero
@[simp]
theorem get_one (h : (1 : PartENat).Dom) : (1 : PartENat).get h = 1 :=
rfl
#align part_enat.get_one PartENat.get_one
-- See note [no_index around OfNat.ofNat]
@[simp]
theorem get_ofNat' (x : ℕ) [x.AtLeastTwo] (h : (no_index (OfNat.ofNat x : PartENat)).Dom) :
Part.get (no_index (OfNat.ofNat x : PartENat)) h = (no_index (OfNat.ofNat x)) :=
get_natCast' x h
nonrec theorem get_eq_iff_eq_some {a : PartENat} {ha : a.Dom} {b : ℕ} : a.get ha = b ↔ a = some b :=
get_eq_iff_eq_some
#align part_enat.get_eq_iff_eq_some PartENat.get_eq_iff_eq_some
theorem get_eq_iff_eq_coe {a : PartENat} {ha : a.Dom} {b : ℕ} : a.get ha = b ↔ a = b := by
rw [get_eq_iff_eq_some]
rfl
#align part_enat.get_eq_iff_eq_coe PartENat.get_eq_iff_eq_coe
theorem dom_of_le_of_dom {x y : PartENat} : x ≤ y → y.Dom → x.Dom := fun ⟨h, _⟩ => h
#align part_enat.dom_of_le_of_dom PartENat.dom_of_le_of_dom
theorem dom_of_le_some {x : PartENat} {y : ℕ} (h : x ≤ some y) : x.Dom :=
dom_of_le_of_dom h trivial
#align part_enat.dom_of_le_some PartENat.dom_of_le_some
theorem dom_of_le_natCast {x : PartENat} {y : ℕ} (h : x ≤ y) : x.Dom := by
exact dom_of_le_some h
#align part_enat.dom_of_le_coe PartENat.dom_of_le_natCast
instance decidableLe (x y : PartENat) [Decidable x.Dom] [Decidable y.Dom] : Decidable (x ≤ y) :=
if hx : x.Dom then
decidable_of_decidable_of_iff (by rw [le_def])
else
if hy : y.Dom then isFalse fun h => hx <| dom_of_le_of_dom h hy
else isTrue ⟨fun h => (hy h).elim, fun h => (hy h).elim⟩
#align part_enat.decidable_le PartENat.decidableLe
-- Porting note: Removed. Use `Nat.castAddMonoidHom` instead.
#noalign part_enat.coe_hom
#noalign part_enat.coe_coe_hom
instance partialOrder : PartialOrder PartENat where
le := (· ≤ ·)
le_refl _ := ⟨id, fun _ => le_rfl⟩
le_trans := fun _ _ _ ⟨hxy₁, hxy₂⟩ ⟨hyz₁, hyz₂⟩ =>
⟨hxy₁ ∘ hyz₁, fun _ => le_trans (hxy₂ _) (hyz₂ _)⟩
lt_iff_le_not_le _ _ := Iff.rfl
le_antisymm := fun _ _ ⟨hxy₁, hxy₂⟩ ⟨hyx₁, hyx₂⟩ =>
Part.ext' ⟨hyx₁, hxy₁⟩ fun _ _ => le_antisymm (hxy₂ _) (hyx₂ _)
theorem lt_def (x y : PartENat) : x < y ↔ ∃ hx : x.Dom, ∀ hy : y.Dom, x.get hx < y.get hy := by
rw [lt_iff_le_not_le, le_def, le_def, not_exists]
constructor
· rintro ⟨⟨hyx, H⟩, h⟩
by_cases hx : x.Dom
· use hx
intro hy
specialize H hy
specialize h fun _ => hy
rw [not_forall] at h
cases' h with hx' h
rw [not_le] at h
exact h
· specialize h fun hx' => (hx hx').elim
rw [not_forall] at h
cases' h with hx' h
exact (hx hx').elim
· rintro ⟨hx, H⟩
exact ⟨⟨fun _ => hx, fun hy => (H hy).le⟩, fun hxy h => not_lt_of_le (h _) (H _)⟩
#align part_enat.lt_def PartENat.lt_def
noncomputable instance orderedAddCommMonoid : OrderedAddCommMonoid PartENat :=
{ PartENat.partialOrder, PartENat.addCommMonoid with
add_le_add_left := fun a b ⟨h₁, h₂⟩ c =>
PartENat.casesOn c (by simp [top_add]) fun c =>
⟨fun h => And.intro (dom_natCast _) (h₁ h.2), fun h => by
simpa only [coe_add_get] using add_le_add_left (h₂ _) c⟩ }
instance semilatticeSup : SemilatticeSup PartENat :=
{ PartENat.partialOrder with
sup := (· ⊔ ·)
le_sup_left := fun _ _ => ⟨And.left, fun _ => le_sup_left⟩
le_sup_right := fun _ _ => ⟨And.right, fun _ => le_sup_right⟩
sup_le := fun _ _ _ ⟨hx₁, hx₂⟩ ⟨hy₁, hy₂⟩ =>
⟨fun hz => ⟨hx₁ hz, hy₁ hz⟩, fun _ => sup_le (hx₂ _) (hy₂ _)⟩ }
#align part_enat.semilattice_sup PartENat.semilatticeSup
instance orderBot : OrderBot PartENat where
bot := ⊥
bot_le _ := ⟨fun _ => trivial, fun _ => Nat.zero_le _⟩
#align part_enat.order_bot PartENat.orderBot
instance orderTop : OrderTop PartENat where
top := ⊤
le_top _ := ⟨fun h => False.elim h, fun hy => False.elim hy⟩
#align part_enat.order_top PartENat.orderTop
instance : ZeroLEOneClass PartENat where
zero_le_one := bot_le
theorem coe_le_coe {x y : ℕ} : (x : PartENat) ≤ y ↔ x ≤ y := Nat.cast_le
#align part_enat.coe_le_coe PartENat.coe_le_coe
theorem coe_lt_coe {x y : ℕ} : (x : PartENat) < y ↔ x < y := Nat.cast_lt
#align part_enat.coe_lt_coe PartENat.coe_lt_coe
@[simp]
| Mathlib/Data/Nat/PartENat.lean | 318 | 321 | theorem get_le_get {x y : PartENat} {hx : x.Dom} {hy : y.Dom} : x.get hx ≤ y.get hy ↔ x ≤ y := by |
conv =>
lhs
rw [← coe_le_coe, natCast_get, natCast_get]
|
import Mathlib.Logic.Relation
import Mathlib.Order.GaloisConnection
#align_import data.setoid.basic from "leanprover-community/mathlib"@"bbeb185db4ccee8ed07dc48449414ebfa39cb821"
variable {α : Type*} {β : Type*}
def Setoid.Rel (r : Setoid α) : α → α → Prop :=
@Setoid.r _ r
#align setoid.rel Setoid.Rel
instance Setoid.decidableRel (r : Setoid α) [h : DecidableRel r.r] : DecidableRel r.Rel :=
h
#align setoid.decidable_rel Setoid.decidableRel
theorem Quotient.eq_rel {r : Setoid α} {x y} :
(Quotient.mk' x : Quotient r) = Quotient.mk' y ↔ r.Rel x y :=
Quotient.eq
#align quotient.eq_rel Quotient.eq_rel
namespace Setoid
@[ext]
theorem ext' {r s : Setoid α} (H : ∀ a b, r.Rel a b ↔ s.Rel a b) : r = s :=
ext H
#align setoid.ext' Setoid.ext'
theorem ext_iff {r s : Setoid α} : r = s ↔ ∀ a b, r.Rel a b ↔ s.Rel a b :=
⟨fun h _ _ => h ▸ Iff.rfl, ext'⟩
#align setoid.ext_iff Setoid.ext_iff
theorem eq_iff_rel_eq {r₁ r₂ : Setoid α} : r₁ = r₂ ↔ r₁.Rel = r₂.Rel :=
⟨fun h => h ▸ rfl, fun h => Setoid.ext' fun _ _ => h ▸ Iff.rfl⟩
#align setoid.eq_iff_rel_eq Setoid.eq_iff_rel_eq
instance : LE (Setoid α) :=
⟨fun r s => ∀ ⦃x y⦄, r.Rel x y → s.Rel x y⟩
theorem le_def {r s : Setoid α} : r ≤ s ↔ ∀ {x y}, r.Rel x y → s.Rel x y :=
Iff.rfl
#align setoid.le_def Setoid.le_def
@[refl]
theorem refl' (r : Setoid α) (x) : r.Rel x x := r.iseqv.refl x
#align setoid.refl' Setoid.refl'
@[symm]
theorem symm' (r : Setoid α) : ∀ {x y}, r.Rel x y → r.Rel y x := r.iseqv.symm
#align setoid.symm' Setoid.symm'
@[trans]
theorem trans' (r : Setoid α) : ∀ {x y z}, r.Rel x y → r.Rel y z → r.Rel x z := r.iseqv.trans
#align setoid.trans' Setoid.trans'
theorem comm' (s : Setoid α) {x y} : s.Rel x y ↔ s.Rel y x :=
⟨s.symm', s.symm'⟩
#align setoid.comm' Setoid.comm'
def ker (f : α → β) : Setoid α :=
⟨(· = ·) on f, eq_equivalence.comap f⟩
#align setoid.ker Setoid.ker
@[simp]
theorem ker_mk_eq (r : Setoid α) : ker (@Quotient.mk'' _ r) = r :=
ext' fun _ _ => Quotient.eq
#align setoid.ker_mk_eq Setoid.ker_mk_eq
theorem ker_apply_mk_out {f : α → β} (a : α) : f (haveI := Setoid.ker f; ⟦a⟧.out) = f a :=
@Quotient.mk_out _ (Setoid.ker f) a
#align setoid.ker_apply_mk_out Setoid.ker_apply_mk_out
theorem ker_apply_mk_out' {f : α → β} (a : α) :
f (Quotient.mk _ a : Quotient <| Setoid.ker f).out' = f a :=
@Quotient.mk_out' _ (Setoid.ker f) a
#align setoid.ker_apply_mk_out' Setoid.ker_apply_mk_out'
theorem ker_def {f : α → β} {x y : α} : (ker f).Rel x y ↔ f x = f y :=
Iff.rfl
#align setoid.ker_def Setoid.ker_def
protected def prod (r : Setoid α) (s : Setoid β) :
Setoid (α × β) where
r x y := r.Rel x.1 y.1 ∧ s.Rel x.2 y.2
iseqv :=
⟨fun x => ⟨r.refl' x.1, s.refl' x.2⟩, fun h => ⟨r.symm' h.1, s.symm' h.2⟩,
fun h₁ h₂ => ⟨r.trans' h₁.1 h₂.1, s.trans' h₁.2 h₂.2⟩⟩
#align setoid.prod Setoid.prod
instance : Inf (Setoid α) :=
⟨fun r s =>
⟨fun x y => r.Rel x y ∧ s.Rel x y,
⟨fun x => ⟨r.refl' x, s.refl' x⟩, fun h => ⟨r.symm' h.1, s.symm' h.2⟩, fun h1 h2 =>
⟨r.trans' h1.1 h2.1, s.trans' h1.2 h2.2⟩⟩⟩⟩
theorem inf_def {r s : Setoid α} : (r ⊓ s).Rel = r.Rel ⊓ s.Rel :=
rfl
#align setoid.inf_def Setoid.inf_def
theorem inf_iff_and {r s : Setoid α} {x y} : (r ⊓ s).Rel x y ↔ r.Rel x y ∧ s.Rel x y :=
Iff.rfl
#align setoid.inf_iff_and Setoid.inf_iff_and
instance : InfSet (Setoid α) :=
⟨fun S =>
{ r := fun x y => ∀ r ∈ S, r.Rel x y
iseqv := ⟨fun x r _ => r.refl' x, fun h r hr => r.symm' <| h r hr, fun h1 h2 r hr =>
r.trans' (h1 r hr) <| h2 r hr⟩ }⟩
theorem sInf_def {s : Set (Setoid α)} : (sInf s).Rel = sInf (Rel '' s) := by
ext
simp only [sInf_image, iInf_apply, iInf_Prop_eq]
rfl
#align setoid.Inf_def Setoid.sInf_def
instance : PartialOrder (Setoid α) where
le := (· ≤ ·)
lt r s := r ≤ s ∧ ¬s ≤ r
le_refl _ _ _ := id
le_trans _ _ _ hr hs _ _ h := hs <| hr h
lt_iff_le_not_le _ _ := Iff.rfl
le_antisymm _ _ h1 h2 := Setoid.ext' fun _ _ => ⟨fun h => h1 h, fun h => h2 h⟩
instance completeLattice : CompleteLattice (Setoid α) :=
{ (completeLatticeOfInf (Setoid α)) fun _ =>
⟨fun _ hr _ _ h => h _ hr, fun _ hr _ _ h _ hr' => hr hr' h⟩ with
inf := Inf.inf
inf_le_left := fun _ _ _ _ h => h.1
inf_le_right := fun _ _ _ _ h => h.2
le_inf := fun _ _ _ h1 h2 _ _ h => ⟨h1 h, h2 h⟩
top := ⟨fun _ _ => True, ⟨fun _ => trivial, fun h => h, fun h1 _ => h1⟩⟩
le_top := fun _ _ _ _ => trivial
bot := ⟨(· = ·), ⟨fun _ => rfl, fun h => h.symm, fun h1 h2 => h1.trans h2⟩⟩
bot_le := fun r x _ h => h ▸ r.2.1 x }
#align setoid.complete_lattice Setoid.completeLattice
@[simp]
theorem top_def : (⊤ : Setoid α).Rel = ⊤ :=
rfl
#align setoid.top_def Setoid.top_def
@[simp]
theorem bot_def : (⊥ : Setoid α).Rel = (· = ·) :=
rfl
#align setoid.bot_def Setoid.bot_def
theorem eq_top_iff {s : Setoid α} : s = (⊤ : Setoid α) ↔ ∀ x y : α, s.Rel x y := by
rw [_root_.eq_top_iff, Setoid.le_def, Setoid.top_def]
simp only [Pi.top_apply, Prop.top_eq_true, forall_true_left]
#align setoid.eq_top_iff Setoid.eq_top_iff
lemma sInf_equiv {S : Set (Setoid α)} {x y : α} :
letI := sInf S
x ≈ y ↔ ∀ s ∈ S, s.Rel x y := Iff.rfl
lemma quotient_mk_sInf_eq {S : Set (Setoid α)} {x y : α} :
Quotient.mk (sInf S) x = Quotient.mk (sInf S) y ↔ ∀ s ∈ S, s.Rel x y := by
simp
rfl
def map_of_le {s t : Setoid α} (h : s ≤ t) : Quotient s → Quotient t :=
Quotient.map' id h
def map_sInf {S : Set (Setoid α)} {s : Setoid α} (h : s ∈ S) :
Quotient (sInf S) → Quotient s :=
Setoid.map_of_le fun _ _ a ↦ a s h
theorem eqvGen_eq (r : α → α → Prop) :
EqvGen.Setoid r = sInf { s : Setoid α | ∀ ⦃x y⦄, r x y → s.Rel x y } :=
le_antisymm
(fun _ _ H =>
EqvGen.rec (fun _ _ h _ hs => hs h) (refl' _) (fun _ _ _ => symm' _)
(fun _ _ _ _ _ => trans' _) H)
(sInf_le fun _ _ h => EqvGen.rel _ _ h)
#align setoid.eqv_gen_eq Setoid.eqvGen_eq
theorem sup_eq_eqvGen (r s : Setoid α) :
r ⊔ s = EqvGen.Setoid fun x y => r.Rel x y ∨ s.Rel x y := by
rw [eqvGen_eq]
apply congr_arg sInf
simp only [le_def, or_imp, ← forall_and]
#align setoid.sup_eq_eqv_gen Setoid.sup_eq_eqvGen
| Mathlib/Data/Setoid/Basic.lean | 240 | 241 | theorem sup_def {r s : Setoid α} : r ⊔ s = EqvGen.Setoid (r.Rel ⊔ s.Rel) := by |
rw [sup_eq_eqvGen]; rfl
|
import Mathlib.Analysis.Convex.Basic
import Mathlib.Order.Closure
#align_import analysis.convex.hull from "leanprover-community/mathlib"@"92bd7b1ffeb306a89f450bee126ddd8a284c259d"
open Set
open Pointwise
variable {𝕜 E F : Type*}
section convexHull
section OrderedSemiring
variable [OrderedSemiring 𝕜]
section AddCommMonoid
variable (𝕜)
variable [AddCommMonoid E] [AddCommMonoid F] [Module 𝕜 E] [Module 𝕜 F]
@[simps! isClosed]
def convexHull : ClosureOperator (Set E) := .ofCompletePred (Convex 𝕜) fun _ ↦ convex_sInter
#align convex_hull convexHull
variable (s : Set E)
theorem subset_convexHull : s ⊆ convexHull 𝕜 s :=
(convexHull 𝕜).le_closure s
#align subset_convex_hull subset_convexHull
theorem convex_convexHull : Convex 𝕜 (convexHull 𝕜 s) := (convexHull 𝕜).isClosed_closure s
#align convex_convex_hull convex_convexHull
theorem convexHull_eq_iInter : convexHull 𝕜 s = ⋂ (t : Set E) (_ : s ⊆ t) (_ : Convex 𝕜 t), t := by
simp [convexHull, iInter_subtype, iInter_and]
#align convex_hull_eq_Inter convexHull_eq_iInter
variable {𝕜 s} {t : Set E} {x y : E}
| Mathlib/Analysis/Convex/Hull.lean | 62 | 63 | theorem mem_convexHull_iff : x ∈ convexHull 𝕜 s ↔ ∀ t, s ⊆ t → Convex 𝕜 t → x ∈ t := by |
simp_rw [convexHull_eq_iInter, mem_iInter]
|
import Mathlib.Tactic.NormNum
import Mathlib.Tactic.TryThis
import Mathlib.Util.AtomM
set_option autoImplicit true
namespace Mathlib.Tactic.Abel
open Lean Elab Meta Tactic Qq
initialize registerTraceClass `abel
initialize registerTraceClass `abel.detail
structure Context where
α : Expr
univ : Level
α0 : Expr
isGroup : Bool
inst : Expr
def mkContext (e : Expr) : MetaM Context := do
let α ← inferType e
let c ← synthInstance (← mkAppM ``AddCommMonoid #[α])
let cg ← synthInstance? (← mkAppM ``AddCommGroup #[α])
let u ← mkFreshLevelMVar
_ ← isDefEq (.sort (.succ u)) (← inferType α)
let α0 ← Expr.ofNat α 0
match cg with
| some cg => return ⟨α, u, α0, true, cg⟩
| _ => return ⟨α, u, α0, false, c⟩
abbrev M := ReaderT Context AtomM
def Context.app (c : Context) (n : Name) (inst : Expr) : Array Expr → Expr :=
mkAppN (((@Expr.const n [c.univ]).app c.α).app inst)
def Context.mkApp (c : Context) (n inst : Name) (l : Array Expr) : MetaM Expr := do
return c.app n (← synthInstance ((Expr.const inst [c.univ]).app c.α)) l
def addG : Name → Name
| .str p s => .str p (s ++ "g")
| n => n
def iapp (n : Name) (xs : Array Expr) : M Expr := do
let c ← read
return c.app (if c.isGroup then addG n else n) c.inst xs
def term {α} [AddCommMonoid α] (n : ℕ) (x a : α) : α := n • x + a
def termg {α} [AddCommGroup α] (n : ℤ) (x a : α) : α := n • x + a
def mkTerm (n x a : Expr) : M Expr := iapp ``term #[n, x, a]
def intToExpr (n : ℤ) : M Expr := do
Expr.ofInt (mkConst (if (← read).isGroup then ``Int else ``Nat) []) n
inductive NormalExpr : Type
| zero (e : Expr) : NormalExpr
| nterm (e : Expr) (n : Expr × ℤ) (x : ℕ × Expr) (a : NormalExpr) : NormalExpr
deriving Inhabited
def NormalExpr.e : NormalExpr → Expr
| .zero e => e
| .nterm e .. => e
instance : Coe NormalExpr Expr where coe := NormalExpr.e
def NormalExpr.term' (n : Expr × ℤ) (x : ℕ × Expr) (a : NormalExpr) : M NormalExpr :=
return .nterm (← mkTerm n.1 x.2 a) n x a
def NormalExpr.zero' : M NormalExpr := return NormalExpr.zero (← read).α0
open NormalExpr
theorem const_add_term {α} [AddCommMonoid α] (k n x a a') (h : k + a = a') :
k + @term α _ n x a = term n x a' := by
simp [h.symm, term, add_comm, add_assoc]
theorem const_add_termg {α} [AddCommGroup α] (k n x a a') (h : k + a = a') :
k + @termg α _ n x a = termg n x a' := by
simp [h.symm, termg, add_comm, add_assoc]
theorem term_add_const {α} [AddCommMonoid α] (n x a k a') (h : a + k = a') :
@term α _ n x a + k = term n x a' := by
simp [h.symm, term, add_assoc]
theorem term_add_constg {α} [AddCommGroup α] (n x a k a') (h : a + k = a') :
@termg α _ n x a + k = termg n x a' := by
simp [h.symm, termg, add_assoc]
theorem term_add_term {α} [AddCommMonoid α] (n₁ x a₁ n₂ a₂ n' a') (h₁ : n₁ + n₂ = n')
(h₂ : a₁ + a₂ = a') : @term α _ n₁ x a₁ + @term α _ n₂ x a₂ = term n' x a' := by
simp [h₁.symm, h₂.symm, term, add_nsmul, add_assoc, add_left_comm]
theorem term_add_termg {α} [AddCommGroup α] (n₁ x a₁ n₂ a₂ n' a')
(h₁ : n₁ + n₂ = n') (h₂ : a₁ + a₂ = a') :
@termg α _ n₁ x a₁ + @termg α _ n₂ x a₂ = termg n' x a' := by
simp only [termg, h₁.symm, add_zsmul, h₂.symm]
exact add_add_add_comm (n₁ • x) a₁ (n₂ • x) a₂
theorem zero_term {α} [AddCommMonoid α] (x a) : @term α _ 0 x a = a := by
simp [term, zero_nsmul, one_nsmul]
theorem zero_termg {α} [AddCommGroup α] (x a) : @termg α _ 0 x a = a := by
simp [termg, zero_zsmul]
partial def evalAdd : NormalExpr → NormalExpr → M (NormalExpr × Expr)
| zero _, e₂ => do
let p ← mkAppM ``zero_add #[e₂]
return (e₂, p)
| e₁, zero _ => do
let p ← mkAppM ``add_zero #[e₁]
return (e₁, p)
| he₁@(nterm e₁ n₁ x₁ a₁), he₂@(nterm e₂ n₂ x₂ a₂) => do
if x₁.1 = x₂.1 then
let n' ← Mathlib.Meta.NormNum.eval (← mkAppM ``HAdd.hAdd #[n₁.1, n₂.1])
let (a', h₂) ← evalAdd a₁ a₂
let k := n₁.2 + n₂.2
let p₁ ← iapp ``term_add_term
#[n₁.1, x₁.2, a₁, n₂.1, a₂, n'.expr, a', ← n'.getProof, h₂]
if k = 0 then do
let p ← mkEqTrans p₁ (← iapp ``zero_term #[x₁.2, a'])
return (a', p)
else return (← term' (n'.expr, k) x₁ a', p₁)
else if x₁.1 < x₂.1 then do
let (a', h) ← evalAdd a₁ he₂
return (← term' n₁ x₁ a', ← iapp ``term_add_const #[n₁.1, x₁.2, a₁, e₂, a', h])
else do
let (a', h) ← evalAdd he₁ a₂
return (← term' n₂ x₂ a', ← iapp ``const_add_term #[e₁, n₂.1, x₂.2, a₂, a', h])
| Mathlib/Tactic/Abel.lean | 188 | 190 | theorem term_neg {α} [AddCommGroup α] (n x a n' a')
(h₁ : -n = n') (h₂ : -a = a') : -@termg α _ n x a = termg n' x a' := by |
simpa [h₂.symm, h₁.symm, termg] using add_comm _ _
|
import Mathlib.Algebra.MvPolynomial.Supported
import Mathlib.RingTheory.WittVector.Truncated
#align_import ring_theory.witt_vector.mul_coeff from "leanprover-community/mathlib"@"2f5b500a507264de86d666a5f87ddb976e2d8de4"
noncomputable section
namespace WittVector
variable (p : ℕ) [hp : Fact p.Prime]
variable {k : Type*} [CommRing k]
local notation "𝕎" => WittVector p
-- Porting note: new notation
local notation "𝕄" => MvPolynomial (Fin 2 × ℕ) ℤ
open Finset MvPolynomial
def wittPolyProd (n : ℕ) : 𝕄 :=
rename (Prod.mk (0 : Fin 2)) (wittPolynomial p ℤ n) *
rename (Prod.mk (1 : Fin 2)) (wittPolynomial p ℤ n)
#align witt_vector.witt_poly_prod WittVector.wittPolyProd
theorem wittPolyProd_vars (n : ℕ) : (wittPolyProd p n).vars ⊆ univ ×ˢ range (n + 1) := by
rw [wittPolyProd]
apply Subset.trans (vars_mul _ _)
refine union_subset ?_ ?_ <;>
· refine Subset.trans (vars_rename _ _) ?_
simp [wittPolynomial_vars, image_subset_iff]
#align witt_vector.witt_poly_prod_vars WittVector.wittPolyProd_vars
def wittPolyProdRemainder (n : ℕ) : 𝕄 :=
∑ i ∈ range n, (p : 𝕄) ^ i * wittMul p i ^ p ^ (n - i)
#align witt_vector.witt_poly_prod_remainder WittVector.wittPolyProdRemainder
theorem wittPolyProdRemainder_vars (n : ℕ) :
(wittPolyProdRemainder p n).vars ⊆ univ ×ˢ range n := by
rw [wittPolyProdRemainder]
refine Subset.trans (vars_sum_subset _ _) ?_
rw [biUnion_subset]
intro x hx
apply Subset.trans (vars_mul _ _)
refine union_subset ?_ ?_
· apply Subset.trans (vars_pow _ _)
have : (p : 𝕄) = C (p : ℤ) := by simp only [Int.cast_natCast, eq_intCast]
rw [this, vars_C]
apply empty_subset
· apply Subset.trans (vars_pow _ _)
apply Subset.trans (wittMul_vars _ _)
apply product_subset_product (Subset.refl _)
simp only [mem_range, range_subset] at hx ⊢
exact hx
#align witt_vector.witt_poly_prod_remainder_vars WittVector.wittPolyProdRemainder_vars
def remainder (n : ℕ) : 𝕄 :=
(∑ x ∈ range (n + 1),
(rename (Prod.mk 0)) ((monomial (Finsupp.single x (p ^ (n + 1 - x)))) ((p : ℤ) ^ x))) *
∑ x ∈ range (n + 1),
(rename (Prod.mk 1)) ((monomial (Finsupp.single x (p ^ (n + 1 - x)))) ((p : ℤ) ^ x))
#align witt_vector.remainder WittVector.remainder
theorem remainder_vars (n : ℕ) : (remainder p n).vars ⊆ univ ×ˢ range (n + 1) := by
rw [remainder]
apply Subset.trans (vars_mul _ _)
refine union_subset ?_ ?_ <;>
· refine Subset.trans (vars_sum_subset _ _) ?_
rw [biUnion_subset]
intro x hx
rw [rename_monomial, vars_monomial, Finsupp.mapDomain_single]
· apply Subset.trans Finsupp.support_single_subset
simpa using mem_range.mp hx
· apply pow_ne_zero
exact mod_cast hp.out.ne_zero
#align witt_vector.remainder_vars WittVector.remainder_vars
def polyOfInterest (n : ℕ) : 𝕄 :=
wittMul p (n + 1) + (p : 𝕄) ^ (n + 1) * X (0, n + 1) * X (1, n + 1) -
X (0, n + 1) * rename (Prod.mk (1 : Fin 2)) (wittPolynomial p ℤ (n + 1)) -
X (1, n + 1) * rename (Prod.mk (0 : Fin 2)) (wittPolynomial p ℤ (n + 1))
#align witt_vector.poly_of_interest WittVector.polyOfInterest
theorem mul_polyOfInterest_aux1 (n : ℕ) :
∑ i ∈ range (n + 1), (p : 𝕄) ^ i * wittMul p i ^ p ^ (n - i) = wittPolyProd p n := by
simp only [wittPolyProd]
convert wittStructureInt_prop p (X (0 : Fin 2) * X 1) n using 1
· simp only [wittPolynomial, wittMul]
rw [AlgHom.map_sum]
congr 1 with i
congr 1
have hsupp : (Finsupp.single i (p ^ (n - i))).support = {i} := by
rw [Finsupp.support_eq_singleton]
simp only [and_true_iff, Finsupp.single_eq_same, eq_self_iff_true, Ne]
exact pow_ne_zero _ hp.out.ne_zero
simp only [bind₁_monomial, hsupp, Int.cast_natCast, prod_singleton, eq_intCast,
Finsupp.single_eq_same, C_pow, mul_eq_mul_left_iff, true_or_iff, eq_self_iff_true,
Int.cast_pow]
· simp only [map_mul, bind₁_X_right]
#align witt_vector.mul_poly_of_interest_aux1 WittVector.mul_polyOfInterest_aux1
theorem mul_polyOfInterest_aux2 (n : ℕ) :
(p : 𝕄) ^ n * wittMul p n + wittPolyProdRemainder p n = wittPolyProd p n := by
convert mul_polyOfInterest_aux1 p n
rw [sum_range_succ, add_comm, Nat.sub_self, pow_zero, pow_one]
rfl
#align witt_vector.mul_poly_of_interest_aux2 WittVector.mul_polyOfInterest_aux2
theorem mul_polyOfInterest_aux3 (n : ℕ) : wittPolyProd p (n + 1) =
-((p : 𝕄) ^ (n + 1) * X (0, n + 1)) * ((p : 𝕄) ^ (n + 1) * X (1, n + 1)) +
(p : 𝕄) ^ (n + 1) * X (0, n + 1) * rename (Prod.mk (1 : Fin 2)) (wittPolynomial p ℤ (n + 1)) +
(p : 𝕄) ^ (n + 1) * X (1, n + 1) * rename (Prod.mk (0 : Fin 2)) (wittPolynomial p ℤ (n + 1)) +
remainder p n := by
-- a useful auxiliary fact
have mvpz : (p : 𝕄) ^ (n + 1) = MvPolynomial.C ((p : ℤ) ^ (n + 1)) := by norm_cast
-- Porting note: the original proof applies `sum_range_succ` through a non-`conv` rewrite,
-- but this does not work in Lean 4; the whole proof also times out very badly. The proof has been
-- nearly totally rewritten here and now finishes quite fast.
rw [wittPolyProd, wittPolynomial, AlgHom.map_sum, AlgHom.map_sum]
conv_lhs =>
arg 1
rw [sum_range_succ, ← C_mul_X_pow_eq_monomial, tsub_self, pow_zero, pow_one, map_mul,
rename_C, rename_X, ← mvpz]
conv_lhs =>
arg 2
rw [sum_range_succ, ← C_mul_X_pow_eq_monomial, tsub_self, pow_zero, pow_one, map_mul,
rename_C, rename_X, ← mvpz]
conv_rhs =>
enter [1, 1, 2, 2]
rw [sum_range_succ, ← C_mul_X_pow_eq_monomial, tsub_self, pow_zero, pow_one, map_mul,
rename_C, rename_X, ← mvpz]
conv_rhs =>
enter [1, 2, 2]
rw [sum_range_succ, ← C_mul_X_pow_eq_monomial, tsub_self, pow_zero, pow_one, map_mul,
rename_C, rename_X, ← mvpz]
simp only [add_mul, mul_add]
rw [add_comm _ (remainder p n)]
simp only [add_assoc]
apply congrArg (Add.add _)
ring
#align witt_vector.mul_poly_of_interest_aux3 WittVector.mul_polyOfInterest_aux3
| Mathlib/RingTheory/WittVector/MulCoeff.lean | 179 | 186 | theorem mul_polyOfInterest_aux4 (n : ℕ) :
(p : 𝕄) ^ (n + 1) * wittMul p (n + 1) =
-((p : 𝕄) ^ (n + 1) * X (0, n + 1)) * ((p : 𝕄) ^ (n + 1) * X (1, n + 1)) +
(p : 𝕄) ^ (n + 1) * X (0, n + 1) * rename (Prod.mk (1 : Fin 2)) (wittPolynomial p ℤ (n + 1)) +
(p : 𝕄) ^ (n + 1) * X (1, n + 1) * rename (Prod.mk (0 : Fin 2)) (wittPolynomial p ℤ (n + 1)) +
(remainder p n - wittPolyProdRemainder p (n + 1)) := by |
rw [← add_sub_assoc, eq_sub_iff_add_eq, mul_polyOfInterest_aux2]
exact mul_polyOfInterest_aux3 _ _
|
import Mathlib.Algebra.Order.ZeroLEOne
import Mathlib.Data.List.InsertNth
import Mathlib.Logic.Relation
import Mathlib.Logic.Small.Defs
import Mathlib.Order.GameAdd
#align_import set_theory.game.pgame from "leanprover-community/mathlib"@"8900d545017cd21961daa2a1734bb658ef52c618"
set_option autoImplicit true
namespace SetTheory
open Function Relation
-- We'd like to be able to use multi-character auto-implicits in this file.
set_option relaxedAutoImplicit true
inductive PGame : Type (u + 1)
| mk : ∀ α β : Type u, (α → PGame) → (β → PGame) → PGame
#align pgame SetTheory.PGame
compile_inductive% PGame
namespace PGame
def LeftMoves : PGame → Type u
| mk l _ _ _ => l
#align pgame.left_moves SetTheory.PGame.LeftMoves
def RightMoves : PGame → Type u
| mk _ r _ _ => r
#align pgame.right_moves SetTheory.PGame.RightMoves
def moveLeft : ∀ g : PGame, LeftMoves g → PGame
| mk _l _ L _ => L
#align pgame.move_left SetTheory.PGame.moveLeft
def moveRight : ∀ g : PGame, RightMoves g → PGame
| mk _ _r _ R => R
#align pgame.move_right SetTheory.PGame.moveRight
@[simp]
theorem leftMoves_mk {xl xr xL xR} : (⟨xl, xr, xL, xR⟩ : PGame).LeftMoves = xl :=
rfl
#align pgame.left_moves_mk SetTheory.PGame.leftMoves_mk
@[simp]
theorem moveLeft_mk {xl xr xL xR} : (⟨xl, xr, xL, xR⟩ : PGame).moveLeft = xL :=
rfl
#align pgame.move_left_mk SetTheory.PGame.moveLeft_mk
@[simp]
theorem rightMoves_mk {xl xr xL xR} : (⟨xl, xr, xL, xR⟩ : PGame).RightMoves = xr :=
rfl
#align pgame.right_moves_mk SetTheory.PGame.rightMoves_mk
@[simp]
theorem moveRight_mk {xl xr xL xR} : (⟨xl, xr, xL, xR⟩ : PGame).moveRight = xR :=
rfl
#align pgame.move_right_mk SetTheory.PGame.moveRight_mk
-- TODO define this at the level of games, as well, and perhaps also for finsets of games.
def ofLists (L R : List PGame.{u}) : PGame.{u} :=
mk (ULift (Fin L.length)) (ULift (Fin R.length)) (fun i => L.get i.down) fun j ↦ R.get j.down
#align pgame.of_lists SetTheory.PGame.ofLists
theorem leftMoves_ofLists (L R : List PGame) : (ofLists L R).LeftMoves = ULift (Fin L.length) :=
rfl
#align pgame.left_moves_of_lists SetTheory.PGame.leftMoves_ofLists
theorem rightMoves_ofLists (L R : List PGame) : (ofLists L R).RightMoves = ULift (Fin R.length) :=
rfl
#align pgame.right_moves_of_lists SetTheory.PGame.rightMoves_ofLists
def toOfListsLeftMoves {L R : List PGame} : Fin L.length ≃ (ofLists L R).LeftMoves :=
((Equiv.cast (leftMoves_ofLists L R).symm).trans Equiv.ulift).symm
#align pgame.to_of_lists_left_moves SetTheory.PGame.toOfListsLeftMoves
def toOfListsRightMoves {L R : List PGame} : Fin R.length ≃ (ofLists L R).RightMoves :=
((Equiv.cast (rightMoves_ofLists L R).symm).trans Equiv.ulift).symm
#align pgame.to_of_lists_right_moves SetTheory.PGame.toOfListsRightMoves
theorem ofLists_moveLeft {L R : List PGame} (i : Fin L.length) :
(ofLists L R).moveLeft (toOfListsLeftMoves i) = L.get i :=
rfl
#align pgame.of_lists_move_left SetTheory.PGame.ofLists_moveLeft
@[simp]
theorem ofLists_moveLeft' {L R : List PGame} (i : (ofLists L R).LeftMoves) :
(ofLists L R).moveLeft i = L.get (toOfListsLeftMoves.symm i) :=
rfl
#align pgame.of_lists_move_left' SetTheory.PGame.ofLists_moveLeft'
theorem ofLists_moveRight {L R : List PGame} (i : Fin R.length) :
(ofLists L R).moveRight (toOfListsRightMoves i) = R.get i :=
rfl
#align pgame.of_lists_move_right SetTheory.PGame.ofLists_moveRight
@[simp]
theorem ofLists_moveRight' {L R : List PGame} (i : (ofLists L R).RightMoves) :
(ofLists L R).moveRight i = R.get (toOfListsRightMoves.symm i) :=
rfl
#align pgame.of_lists_move_right' SetTheory.PGame.ofLists_moveRight'
@[elab_as_elim]
def moveRecOn {C : PGame → Sort*} (x : PGame)
(IH : ∀ y : PGame, (∀ i, C (y.moveLeft i)) → (∀ j, C (y.moveRight j)) → C y) : C x :=
x.recOn fun yl yr yL yR => IH (mk yl yr yL yR)
#align pgame.move_rec_on SetTheory.PGame.moveRecOn
@[mk_iff]
inductive IsOption : PGame → PGame → Prop
| moveLeft {x : PGame} (i : x.LeftMoves) : IsOption (x.moveLeft i) x
| moveRight {x : PGame} (i : x.RightMoves) : IsOption (x.moveRight i) x
#align pgame.is_option SetTheory.PGame.IsOption
theorem IsOption.mk_left {xl xr : Type u} (xL : xl → PGame) (xR : xr → PGame) (i : xl) :
(xL i).IsOption (mk xl xr xL xR) :=
@IsOption.moveLeft (mk _ _ _ _) i
#align pgame.is_option.mk_left SetTheory.PGame.IsOption.mk_left
theorem IsOption.mk_right {xl xr : Type u} (xL : xl → PGame) (xR : xr → PGame) (i : xr) :
(xR i).IsOption (mk xl xr xL xR) :=
@IsOption.moveRight (mk _ _ _ _) i
#align pgame.is_option.mk_right SetTheory.PGame.IsOption.mk_right
theorem wf_isOption : WellFounded IsOption :=
⟨fun x =>
moveRecOn x fun x IHl IHr =>
Acc.intro x fun y h => by
induction' h with _ i _ j
· exact IHl i
· exact IHr j⟩
#align pgame.wf_is_option SetTheory.PGame.wf_isOption
def Subsequent : PGame → PGame → Prop :=
TransGen IsOption
#align pgame.subsequent SetTheory.PGame.Subsequent
instance : IsTrans _ Subsequent :=
inferInstanceAs <| IsTrans _ (TransGen _)
@[trans]
theorem Subsequent.trans {x y z} : Subsequent x y → Subsequent y z → Subsequent x z :=
TransGen.trans
#align pgame.subsequent.trans SetTheory.PGame.Subsequent.trans
theorem wf_subsequent : WellFounded Subsequent :=
wf_isOption.transGen
#align pgame.wf_subsequent SetTheory.PGame.wf_subsequent
instance : WellFoundedRelation PGame :=
⟨_, wf_subsequent⟩
@[simp]
theorem Subsequent.moveLeft {x : PGame} (i : x.LeftMoves) : Subsequent (x.moveLeft i) x :=
TransGen.single (IsOption.moveLeft i)
#align pgame.subsequent.move_left SetTheory.PGame.Subsequent.moveLeft
@[simp]
theorem Subsequent.moveRight {x : PGame} (j : x.RightMoves) : Subsequent (x.moveRight j) x :=
TransGen.single (IsOption.moveRight j)
#align pgame.subsequent.move_right SetTheory.PGame.Subsequent.moveRight
@[simp]
theorem Subsequent.mk_left {xl xr} (xL : xl → PGame) (xR : xr → PGame) (i : xl) :
Subsequent (xL i) (mk xl xr xL xR) :=
@Subsequent.moveLeft (mk _ _ _ _) i
#align pgame.subsequent.mk_left SetTheory.PGame.Subsequent.mk_left
@[simp]
theorem Subsequent.mk_right {xl xr} (xL : xl → PGame) (xR : xr → PGame) (j : xr) :
Subsequent (xR j) (mk xl xr xL xR) :=
@Subsequent.moveRight (mk _ _ _ _) j
#align pgame.subsequent.mk_right SetTheory.PGame.Subsequent.mk_right
macro "pgame_wf_tac" : tactic =>
`(tactic| solve_by_elim (config := { maxDepth := 8 })
[Prod.Lex.left, Prod.Lex.right, PSigma.Lex.left, PSigma.Lex.right,
Subsequent.moveLeft, Subsequent.moveRight, Subsequent.mk_left, Subsequent.mk_right,
Subsequent.trans] )
-- Register some consequences of pgame_wf_tac as simp-lemmas for convenience
-- (which are applied by default for WF goals)
-- This is different from mk_right from the POV of the simplifier,
-- because the unifier can't solve `xr =?= RightMoves (mk xl xr xL xR)` at reducible transparency.
@[simp]
theorem Subsequent.mk_right' (xL : xl → PGame) (xR : xr → PGame) (j : RightMoves (mk xl xr xL xR)) :
Subsequent (xR j) (mk xl xr xL xR) := by
pgame_wf_tac
@[simp] theorem Subsequent.moveRight_mk_left (xL : xl → PGame) (j) :
Subsequent ((xL i).moveRight j) (mk xl xr xL xR) := by
pgame_wf_tac
@[simp] theorem Subsequent.moveRight_mk_right (xR : xr → PGame) (j) :
Subsequent ((xR i).moveRight j) (mk xl xr xL xR) := by
pgame_wf_tac
@[simp] theorem Subsequent.moveLeft_mk_left (xL : xl → PGame) (j) :
Subsequent ((xL i).moveLeft j) (mk xl xr xL xR) := by
pgame_wf_tac
@[simp] theorem Subsequent.moveLeft_mk_right (xR : xr → PGame) (j) :
Subsequent ((xR i).moveLeft j) (mk xl xr xL xR) := by
pgame_wf_tac
-- Porting note: linter claims these lemmas don't simplify?
open Subsequent in attribute [nolint simpNF] mk_left mk_right mk_right'
moveRight_mk_left moveRight_mk_right moveLeft_mk_left moveLeft_mk_right
instance : Zero PGame :=
⟨⟨PEmpty, PEmpty, PEmpty.elim, PEmpty.elim⟩⟩
@[simp]
theorem zero_leftMoves : LeftMoves 0 = PEmpty :=
rfl
#align pgame.zero_left_moves SetTheory.PGame.zero_leftMoves
@[simp]
theorem zero_rightMoves : RightMoves 0 = PEmpty :=
rfl
#align pgame.zero_right_moves SetTheory.PGame.zero_rightMoves
instance isEmpty_zero_leftMoves : IsEmpty (LeftMoves 0) :=
instIsEmptyPEmpty
#align pgame.is_empty_zero_left_moves SetTheory.PGame.isEmpty_zero_leftMoves
instance isEmpty_zero_rightMoves : IsEmpty (RightMoves 0) :=
instIsEmptyPEmpty
#align pgame.is_empty_zero_right_moves SetTheory.PGame.isEmpty_zero_rightMoves
instance : Inhabited PGame :=
⟨0⟩
instance instOnePGame : One PGame :=
⟨⟨PUnit, PEmpty, fun _ => 0, PEmpty.elim⟩⟩
@[simp]
theorem one_leftMoves : LeftMoves 1 = PUnit :=
rfl
#align pgame.one_left_moves SetTheory.PGame.one_leftMoves
@[simp]
theorem one_moveLeft (x) : moveLeft 1 x = 0 :=
rfl
#align pgame.one_move_left SetTheory.PGame.one_moveLeft
@[simp]
theorem one_rightMoves : RightMoves 1 = PEmpty :=
rfl
#align pgame.one_right_moves SetTheory.PGame.one_rightMoves
instance uniqueOneLeftMoves : Unique (LeftMoves 1) :=
PUnit.unique
#align pgame.unique_one_left_moves SetTheory.PGame.uniqueOneLeftMoves
instance isEmpty_one_rightMoves : IsEmpty (RightMoves 1) :=
instIsEmptyPEmpty
#align pgame.is_empty_one_right_moves SetTheory.PGame.isEmpty_one_rightMoves
instance le : LE PGame :=
⟨Sym2.GameAdd.fix wf_isOption fun x y le =>
(∀ i, ¬le y (x.moveLeft i) (Sym2.GameAdd.snd_fst <| IsOption.moveLeft i)) ∧
∀ j, ¬le (y.moveRight j) x (Sym2.GameAdd.fst_snd <| IsOption.moveRight j)⟩
def LF (x y : PGame) : Prop :=
¬y ≤ x
#align pgame.lf SetTheory.PGame.LF
@[inherit_doc]
scoped infixl:50 " ⧏ " => PGame.LF
@[simp]
protected theorem not_le {x y : PGame} : ¬x ≤ y ↔ y ⧏ x :=
Iff.rfl
#align pgame.not_le SetTheory.PGame.not_le
@[simp]
theorem not_lf {x y : PGame} : ¬x ⧏ y ↔ y ≤ x :=
Classical.not_not
#align pgame.not_lf SetTheory.PGame.not_lf
theorem _root_.LE.le.not_gf {x y : PGame} : x ≤ y → ¬y ⧏ x :=
not_lf.2
#align has_le.le.not_gf LE.le.not_gf
theorem LF.not_ge {x y : PGame} : x ⧏ y → ¬y ≤ x :=
id
#align pgame.lf.not_ge SetTheory.PGame.LF.not_ge
theorem le_iff_forall_lf {x y : PGame} :
x ≤ y ↔ (∀ i, x.moveLeft i ⧏ y) ∧ ∀ j, x ⧏ y.moveRight j := by
unfold LE.le le
simp only
rw [Sym2.GameAdd.fix_eq]
rfl
#align pgame.le_iff_forall_lf SetTheory.PGame.le_iff_forall_lf
@[simp]
theorem mk_le_mk {xl xr xL xR yl yr yL yR} :
mk xl xr xL xR ≤ mk yl yr yL yR ↔ (∀ i, xL i ⧏ mk yl yr yL yR) ∧ ∀ j, mk xl xr xL xR ⧏ yR j :=
le_iff_forall_lf
#align pgame.mk_le_mk SetTheory.PGame.mk_le_mk
theorem le_of_forall_lf {x y : PGame} (h₁ : ∀ i, x.moveLeft i ⧏ y) (h₂ : ∀ j, x ⧏ y.moveRight j) :
x ≤ y :=
le_iff_forall_lf.2 ⟨h₁, h₂⟩
#align pgame.le_of_forall_lf SetTheory.PGame.le_of_forall_lf
theorem lf_iff_exists_le {x y : PGame} :
x ⧏ y ↔ (∃ i, x ≤ y.moveLeft i) ∨ ∃ j, x.moveRight j ≤ y := by
rw [LF, le_iff_forall_lf, not_and_or]
simp
#align pgame.lf_iff_exists_le SetTheory.PGame.lf_iff_exists_le
@[simp]
theorem mk_lf_mk {xl xr xL xR yl yr yL yR} :
mk xl xr xL xR ⧏ mk yl yr yL yR ↔ (∃ i, mk xl xr xL xR ≤ yL i) ∨ ∃ j, xR j ≤ mk yl yr yL yR :=
lf_iff_exists_le
#align pgame.mk_lf_mk SetTheory.PGame.mk_lf_mk
theorem le_or_gf (x y : PGame) : x ≤ y ∨ y ⧏ x := by
rw [← PGame.not_le]
apply em
#align pgame.le_or_gf SetTheory.PGame.le_or_gf
theorem moveLeft_lf_of_le {x y : PGame} (h : x ≤ y) (i) : x.moveLeft i ⧏ y :=
(le_iff_forall_lf.1 h).1 i
#align pgame.move_left_lf_of_le SetTheory.PGame.moveLeft_lf_of_le
alias _root_.LE.le.moveLeft_lf := moveLeft_lf_of_le
#align has_le.le.move_left_lf LE.le.moveLeft_lf
theorem lf_moveRight_of_le {x y : PGame} (h : x ≤ y) (j) : x ⧏ y.moveRight j :=
(le_iff_forall_lf.1 h).2 j
#align pgame.lf_move_right_of_le SetTheory.PGame.lf_moveRight_of_le
alias _root_.LE.le.lf_moveRight := lf_moveRight_of_le
#align has_le.le.lf_move_right LE.le.lf_moveRight
theorem lf_of_moveRight_le {x y : PGame} {j} (h : x.moveRight j ≤ y) : x ⧏ y :=
lf_iff_exists_le.2 <| Or.inr ⟨j, h⟩
#align pgame.lf_of_move_right_le SetTheory.PGame.lf_of_moveRight_le
theorem lf_of_le_moveLeft {x y : PGame} {i} (h : x ≤ y.moveLeft i) : x ⧏ y :=
lf_iff_exists_le.2 <| Or.inl ⟨i, h⟩
#align pgame.lf_of_le_move_left SetTheory.PGame.lf_of_le_moveLeft
theorem lf_of_le_mk {xl xr xL xR y} : mk xl xr xL xR ≤ y → ∀ i, xL i ⧏ y :=
moveLeft_lf_of_le
#align pgame.lf_of_le_mk SetTheory.PGame.lf_of_le_mk
theorem lf_of_mk_le {x yl yr yL yR} : x ≤ mk yl yr yL yR → ∀ j, x ⧏ yR j :=
lf_moveRight_of_le
#align pgame.lf_of_mk_le SetTheory.PGame.lf_of_mk_le
theorem mk_lf_of_le {xl xr y j} (xL) {xR : xr → PGame} : xR j ≤ y → mk xl xr xL xR ⧏ y :=
@lf_of_moveRight_le (mk _ _ _ _) y j
#align pgame.mk_lf_of_le SetTheory.PGame.mk_lf_of_le
theorem lf_mk_of_le {x yl yr} {yL : yl → PGame} (yR) {i} : x ≤ yL i → x ⧏ mk yl yr yL yR :=
@lf_of_le_moveLeft x (mk _ _ _ _) i
#align pgame.lf_mk_of_le SetTheory.PGame.lf_mk_of_le
private theorem le_trans_aux {x y z : PGame}
(h₁ : ∀ {i}, y ≤ z → z ≤ x.moveLeft i → y ≤ x.moveLeft i)
(h₂ : ∀ {j}, z.moveRight j ≤ x → x ≤ y → z.moveRight j ≤ y) (hxy : x ≤ y) (hyz : y ≤ z) :
x ≤ z :=
le_of_forall_lf (fun i => PGame.not_le.1 fun h => (h₁ hyz h).not_gf <| hxy.moveLeft_lf i)
fun j => PGame.not_le.1 fun h => (h₂ h hxy).not_gf <| hyz.lf_moveRight j
instance : Preorder PGame :=
{ PGame.le with
le_refl := fun x => by
induction' x with _ _ _ _ IHl IHr
exact
le_of_forall_lf (fun i => lf_of_le_moveLeft (IHl i)) fun i => lf_of_moveRight_le (IHr i)
le_trans := by
suffices
∀ {x y z : PGame},
(x ≤ y → y ≤ z → x ≤ z) ∧ (y ≤ z → z ≤ x → y ≤ x) ∧ (z ≤ x → x ≤ y → z ≤ y) from
fun x y z => this.1
intro x y z
induction' x with xl xr xL xR IHxl IHxr generalizing y z
induction' y with yl yr yL yR IHyl IHyr generalizing z
induction' z with zl zr zL zR IHzl IHzr
exact
⟨le_trans_aux (fun {i} => (IHxl i).2.1) fun {j} => (IHzr j).2.2,
le_trans_aux (fun {i} => (IHyl i).2.2) fun {j} => (IHxr j).1,
le_trans_aux (fun {i} => (IHzl i).1) fun {j} => (IHyr j).2.1⟩
lt := fun x y => x ≤ y ∧ x ⧏ y }
theorem lt_iff_le_and_lf {x y : PGame} : x < y ↔ x ≤ y ∧ x ⧏ y :=
Iff.rfl
#align pgame.lt_iff_le_and_lf SetTheory.PGame.lt_iff_le_and_lf
theorem lt_of_le_of_lf {x y : PGame} (h₁ : x ≤ y) (h₂ : x ⧏ y) : x < y :=
⟨h₁, h₂⟩
#align pgame.lt_of_le_of_lf SetTheory.PGame.lt_of_le_of_lf
theorem lf_of_lt {x y : PGame} (h : x < y) : x ⧏ y :=
h.2
#align pgame.lf_of_lt SetTheory.PGame.lf_of_lt
alias _root_.LT.lt.lf := lf_of_lt
#align has_lt.lt.lf LT.lt.lf
theorem lf_irrefl (x : PGame) : ¬x ⧏ x :=
le_rfl.not_gf
#align pgame.lf_irrefl SetTheory.PGame.lf_irrefl
instance : IsIrrefl _ (· ⧏ ·) :=
⟨lf_irrefl⟩
@[trans]
theorem lf_of_le_of_lf {x y z : PGame} (h₁ : x ≤ y) (h₂ : y ⧏ z) : x ⧏ z := by
rw [← PGame.not_le] at h₂ ⊢
exact fun h₃ => h₂ (h₃.trans h₁)
#align pgame.lf_of_le_of_lf SetTheory.PGame.lf_of_le_of_lf
-- Porting note (#10754): added instance
instance : Trans (· ≤ ·) (· ⧏ ·) (· ⧏ ·) := ⟨lf_of_le_of_lf⟩
@[trans]
theorem lf_of_lf_of_le {x y z : PGame} (h₁ : x ⧏ y) (h₂ : y ≤ z) : x ⧏ z := by
rw [← PGame.not_le] at h₁ ⊢
exact fun h₃ => h₁ (h₂.trans h₃)
#align pgame.lf_of_lf_of_le SetTheory.PGame.lf_of_lf_of_le
-- Porting note (#10754): added instance
instance : Trans (· ⧏ ·) (· ≤ ·) (· ⧏ ·) := ⟨lf_of_lf_of_le⟩
alias _root_.LE.le.trans_lf := lf_of_le_of_lf
#align has_le.le.trans_lf LE.le.trans_lf
alias LF.trans_le := lf_of_lf_of_le
#align pgame.lf.trans_le SetTheory.PGame.LF.trans_le
@[trans]
theorem lf_of_lt_of_lf {x y z : PGame} (h₁ : x < y) (h₂ : y ⧏ z) : x ⧏ z :=
h₁.le.trans_lf h₂
#align pgame.lf_of_lt_of_lf SetTheory.PGame.lf_of_lt_of_lf
@[trans]
theorem lf_of_lf_of_lt {x y z : PGame} (h₁ : x ⧏ y) (h₂ : y < z) : x ⧏ z :=
h₁.trans_le h₂.le
#align pgame.lf_of_lf_of_lt SetTheory.PGame.lf_of_lf_of_lt
alias _root_.LT.lt.trans_lf := lf_of_lt_of_lf
#align has_lt.lt.trans_lf LT.lt.trans_lf
alias LF.trans_lt := lf_of_lf_of_lt
#align pgame.lf.trans_lt SetTheory.PGame.LF.trans_lt
theorem moveLeft_lf {x : PGame} : ∀ i, x.moveLeft i ⧏ x :=
le_rfl.moveLeft_lf
#align pgame.move_left_lf SetTheory.PGame.moveLeft_lf
theorem lf_moveRight {x : PGame} : ∀ j, x ⧏ x.moveRight j :=
le_rfl.lf_moveRight
#align pgame.lf_move_right SetTheory.PGame.lf_moveRight
theorem lf_mk {xl xr} (xL : xl → PGame) (xR : xr → PGame) (i) : xL i ⧏ mk xl xr xL xR :=
@moveLeft_lf (mk _ _ _ _) i
#align pgame.lf_mk SetTheory.PGame.lf_mk
theorem mk_lf {xl xr} (xL : xl → PGame) (xR : xr → PGame) (j) : mk xl xr xL xR ⧏ xR j :=
@lf_moveRight (mk _ _ _ _) j
#align pgame.mk_lf SetTheory.PGame.mk_lf
theorem le_of_forall_lt {x y : PGame} (h₁ : ∀ i, x.moveLeft i < y) (h₂ : ∀ j, x < y.moveRight j) :
x ≤ y :=
le_of_forall_lf (fun i => (h₁ i).lf) fun i => (h₂ i).lf
#align pgame.le_of_forall_lt SetTheory.PGame.le_of_forall_lt
theorem le_def {x y : PGame} :
x ≤ y ↔
(∀ i, (∃ i', x.moveLeft i ≤ y.moveLeft i') ∨ ∃ j, (x.moveLeft i).moveRight j ≤ y) ∧
∀ j, (∃ i, x ≤ (y.moveRight j).moveLeft i) ∨ ∃ j', x.moveRight j' ≤ y.moveRight j := by
rw [le_iff_forall_lf]
conv =>
lhs
simp only [lf_iff_exists_le]
#align pgame.le_def SetTheory.PGame.le_def
theorem lf_def {x y : PGame} :
x ⧏ y ↔
(∃ i, (∀ i', x.moveLeft i' ⧏ y.moveLeft i) ∧ ∀ j, x ⧏ (y.moveLeft i).moveRight j) ∨
∃ j, (∀ i, (x.moveRight j).moveLeft i ⧏ y) ∧ ∀ j', x.moveRight j ⧏ y.moveRight j' := by
rw [lf_iff_exists_le]
conv =>
lhs
simp only [le_iff_forall_lf]
#align pgame.lf_def SetTheory.PGame.lf_def
theorem zero_le_lf {x : PGame} : 0 ≤ x ↔ ∀ j, 0 ⧏ x.moveRight j := by
rw [le_iff_forall_lf]
simp
#align pgame.zero_le_lf SetTheory.PGame.zero_le_lf
theorem le_zero_lf {x : PGame} : x ≤ 0 ↔ ∀ i, x.moveLeft i ⧏ 0 := by
rw [le_iff_forall_lf]
simp
#align pgame.le_zero_lf SetTheory.PGame.le_zero_lf
theorem zero_lf_le {x : PGame} : 0 ⧏ x ↔ ∃ i, 0 ≤ x.moveLeft i := by
rw [lf_iff_exists_le]
simp
#align pgame.zero_lf_le SetTheory.PGame.zero_lf_le
theorem lf_zero_le {x : PGame} : x ⧏ 0 ↔ ∃ j, x.moveRight j ≤ 0 := by
rw [lf_iff_exists_le]
simp
#align pgame.lf_zero_le SetTheory.PGame.lf_zero_le
theorem zero_le {x : PGame} : 0 ≤ x ↔ ∀ j, ∃ i, 0 ≤ (x.moveRight j).moveLeft i := by
rw [le_def]
simp
#align pgame.zero_le SetTheory.PGame.zero_le
| Mathlib/SetTheory/Game/PGame.lean | 677 | 679 | theorem le_zero {x : PGame} : x ≤ 0 ↔ ∀ i, ∃ j, (x.moveLeft i).moveRight j ≤ 0 := by |
rw [le_def]
simp
|
import Mathlib.RingTheory.RootsOfUnity.Basic
import Mathlib.FieldTheory.Minpoly.IsIntegrallyClosed
import Mathlib.Algebra.GCDMonoid.IntegrallyClosed
import Mathlib.FieldTheory.Finite.Basic
#align_import ring_theory.roots_of_unity.minpoly from "leanprover-community/mathlib"@"7fdeecc0d03cd40f7a165e6cf00a4d2286db599f"
open minpoly Polynomial
open scoped Polynomial
namespace IsPrimitiveRoot
section CommRing
variable {n : ℕ} {K : Type*} [CommRing K] {μ : K} (h : IsPrimitiveRoot μ n)
-- Porting note: `hpos` was in the `variable` line, with an `omit` in mathlib3 just after this
-- declaration. For some reason, in Lean4, `hpos` gets included also in the declarations below,
-- even if it is not used in the proof.
theorem isIntegral (hpos : 0 < n) : IsIntegral ℤ μ := by
use X ^ n - 1
constructor
· exact monic_X_pow_sub_C 1 (ne_of_lt hpos).symm
· simp only [((IsPrimitiveRoot.iff_def μ n).mp h).left, eval₂_one, eval₂_X_pow, eval₂_sub,
sub_self]
#align is_primitive_root.is_integral IsPrimitiveRoot.isIntegral
section IsDomain
variable [IsDomain K] [CharZero K]
theorem minpoly_dvd_x_pow_sub_one : minpoly ℤ μ ∣ X ^ n - 1 := by
rcases n.eq_zero_or_pos with (rfl | h0)
· simp
apply minpoly.isIntegrallyClosed_dvd (isIntegral h h0)
simp only [((IsPrimitiveRoot.iff_def μ n).mp h).left, aeval_X_pow, eq_intCast, Int.cast_one,
aeval_one, AlgHom.map_sub, sub_self]
set_option linter.uppercaseLean3 false in
#align is_primitive_root.minpoly_dvd_X_pow_sub_one IsPrimitiveRoot.minpoly_dvd_x_pow_sub_one
theorem separable_minpoly_mod {p : ℕ} [Fact p.Prime] (hdiv : ¬p ∣ n) :
Separable (map (Int.castRingHom (ZMod p)) (minpoly ℤ μ)) := by
have hdvd : map (Int.castRingHom (ZMod p)) (minpoly ℤ μ) ∣ X ^ n - 1 := by
convert RingHom.map_dvd (mapRingHom (Int.castRingHom (ZMod p)))
(minpoly_dvd_x_pow_sub_one h)
simp only [map_sub, map_pow, coe_mapRingHom, map_X, map_one]
refine Separable.of_dvd (separable_X_pow_sub_C 1 ?_ one_ne_zero) hdvd
by_contra hzero
exact hdiv ((ZMod.natCast_zmod_eq_zero_iff_dvd n p).1 hzero)
#align is_primitive_root.separable_minpoly_mod IsPrimitiveRoot.separable_minpoly_mod
theorem squarefree_minpoly_mod {p : ℕ} [Fact p.Prime] (hdiv : ¬p ∣ n) :
Squarefree (map (Int.castRingHom (ZMod p)) (minpoly ℤ μ)) :=
(separable_minpoly_mod h hdiv).squarefree
#align is_primitive_root.squarefree_minpoly_mod IsPrimitiveRoot.squarefree_minpoly_mod
theorem minpoly_dvd_expand {p : ℕ} (hdiv : ¬p ∣ n) :
minpoly ℤ μ ∣ expand ℤ p (minpoly ℤ (μ ^ p)) := by
rcases n.eq_zero_or_pos with (rfl | hpos)
· simp_all
letI : IsIntegrallyClosed ℤ := GCDMonoid.toIsIntegrallyClosed
refine minpoly.isIntegrallyClosed_dvd (h.isIntegral hpos) ?_
rw [aeval_def, coe_expand, ← comp, eval₂_eq_eval_map, map_comp, Polynomial.map_pow, map_X,
eval_comp, eval_pow, eval_X, ← eval₂_eq_eval_map, ← aeval_def]
exact minpoly.aeval _ _
#align is_primitive_root.minpoly_dvd_expand IsPrimitiveRoot.minpoly_dvd_expand
| Mathlib/RingTheory/RootsOfUnity/Minpoly.lean | 95 | 104 | theorem minpoly_dvd_pow_mod {p : ℕ} [hprime : Fact p.Prime] (hdiv : ¬p ∣ n) :
map (Int.castRingHom (ZMod p)) (minpoly ℤ μ) ∣
map (Int.castRingHom (ZMod p)) (minpoly ℤ (μ ^ p)) ^ p := by |
set Q := minpoly ℤ (μ ^ p)
have hfrob :
map (Int.castRingHom (ZMod p)) Q ^ p = map (Int.castRingHom (ZMod p)) (expand ℤ p Q) := by
rw [← ZMod.expand_card, map_expand]
rw [hfrob]
apply RingHom.map_dvd (mapRingHom (Int.castRingHom (ZMod p)))
exact minpoly_dvd_expand h hdiv
|
import Mathlib.Algebra.GroupWithZero.Divisibility
import Mathlib.Algebra.Order.Ring.Nat
import Mathlib.Tactic.NthRewrite
#align_import data.nat.gcd.basic from "leanprover-community/mathlib"@"e8638a0fcaf73e4500469f368ef9494e495099b3"
namespace Nat
theorem gcd_greatest {a b d : ℕ} (hda : d ∣ a) (hdb : d ∣ b) (hd : ∀ e : ℕ, e ∣ a → e ∣ b → e ∣ d) :
d = a.gcd b :=
(dvd_antisymm (hd _ (gcd_dvd_left a b) (gcd_dvd_right a b)) (dvd_gcd hda hdb)).symm
#align nat.gcd_greatest Nat.gcd_greatest
@[simp]
theorem gcd_add_mul_right_right (m n k : ℕ) : gcd m (n + k * m) = gcd m n := by
simp [gcd_rec m (n + k * m), gcd_rec m n]
#align nat.gcd_add_mul_right_right Nat.gcd_add_mul_right_right
@[simp]
theorem gcd_add_mul_left_right (m n k : ℕ) : gcd m (n + m * k) = gcd m n := by
simp [gcd_rec m (n + m * k), gcd_rec m n]
#align nat.gcd_add_mul_left_right Nat.gcd_add_mul_left_right
@[simp]
| Mathlib/Data/Nat/GCD/Basic.lean | 45 | 45 | theorem gcd_mul_right_add_right (m n k : ℕ) : gcd m (k * m + n) = gcd m n := by | simp [add_comm _ n]
|
import Mathlib.CategoryTheory.Subobject.Limits
#align_import algebra.homology.image_to_kernel from "leanprover-community/mathlib"@"618ea3d5c99240cd7000d8376924906a148bf9ff"
universe v u w
open CategoryTheory CategoryTheory.Limits
variable {ι : Type*}
variable {V : Type u} [Category.{v} V] [HasZeroMorphisms V]
open scoped Classical
noncomputable section
section
variable {A B C : V} (f : A ⟶ B) [HasImage f] (g : B ⟶ C) [HasKernel g]
theorem image_le_kernel (w : f ≫ g = 0) : imageSubobject f ≤ kernelSubobject g :=
imageSubobject_le_mk _ _ (kernel.lift _ _ w) (by simp)
#align image_le_kernel image_le_kernel
def imageToKernel (w : f ≫ g = 0) : (imageSubobject f : V) ⟶ (kernelSubobject g : V) :=
Subobject.ofLE _ _ (image_le_kernel _ _ w)
#align image_to_kernel imageToKernel
instance (w : f ≫ g = 0) : Mono (imageToKernel f g w) := by
dsimp only [imageToKernel]
infer_instance
@[simp]
theorem subobject_ofLE_as_imageToKernel (w : f ≫ g = 0) (h) :
Subobject.ofLE (imageSubobject f) (kernelSubobject g) h = imageToKernel f g w :=
rfl
#align subobject_of_le_as_image_to_kernel subobject_ofLE_as_imageToKernel
attribute [local instance] ConcreteCategory.instFunLike
-- Porting note: removed elementwise attribute which does not seem to be helpful here
-- a more suitable lemma is added below
@[reassoc (attr := simp)]
theorem imageToKernel_arrow (w : f ≫ g = 0) :
imageToKernel f g w ≫ (kernelSubobject g).arrow = (imageSubobject f).arrow := by
simp [imageToKernel]
#align image_to_kernel_arrow imageToKernel_arrow
@[simp]
lemma imageToKernel_arrow_apply [ConcreteCategory V] (w : f ≫ g = 0)
(x : (forget V).obj (Subobject.underlying.obj (imageSubobject f))) :
(kernelSubobject g).arrow (imageToKernel f g w x) =
(imageSubobject f).arrow x := by
rw [← comp_apply, imageToKernel_arrow]
-- This is less useful as a `simp` lemma than it initially appears,
-- as it "loses" the information the morphism factors through the image.
theorem factorThruImageSubobject_comp_imageToKernel (w : f ≫ g = 0) :
factorThruImageSubobject f ≫ imageToKernel f g w = factorThruKernelSubobject g f w := by
ext
simp
#align factor_thru_image_subobject_comp_image_to_kernel factorThruImageSubobject_comp_imageToKernel
end
section
variable {A B C : V} (f : A ⟶ B) (g : B ⟶ C)
@[simp]
theorem imageToKernel_zero_left [HasKernels V] [HasZeroObject V] {w} :
imageToKernel (0 : A ⟶ B) g w = 0 := by
ext
simp
#align image_to_kernel_zero_left imageToKernel_zero_left
theorem imageToKernel_zero_right [HasImages V] {w} :
imageToKernel f (0 : B ⟶ C) w =
(imageSubobject f).arrow ≫ inv (kernelSubobject (0 : B ⟶ C)).arrow := by
ext
simp
#align image_to_kernel_zero_right imageToKernel_zero_right
section
variable [HasKernels V] [HasImages V]
theorem imageToKernel_comp_right {D : V} (h : C ⟶ D) (w : f ≫ g = 0) :
imageToKernel f (g ≫ h) (by simp [reassoc_of% w]) =
imageToKernel f g w ≫ Subobject.ofLE _ _ (kernelSubobject_comp_le g h) := by
ext
simp
#align image_to_kernel_comp_right imageToKernel_comp_right
theorem imageToKernel_comp_left {Z : V} (h : Z ⟶ A) (w : f ≫ g = 0) :
imageToKernel (h ≫ f) g (by simp [w]) =
Subobject.ofLE _ _ (imageSubobject_comp_le h f) ≫ imageToKernel f g w := by
ext
simp
#align image_to_kernel_comp_left imageToKernel_comp_left
@[simp]
theorem imageToKernel_comp_mono {D : V} (h : C ⟶ D) [Mono h] (w) :
imageToKernel f (g ≫ h) w =
imageToKernel f g ((cancel_mono h).mp (by simpa using w : (f ≫ g) ≫ h = 0 ≫ h)) ≫
(Subobject.isoOfEq _ _ (kernelSubobject_comp_mono g h)).inv := by
ext
simp
#align image_to_kernel_comp_mono imageToKernel_comp_mono
@[simp]
theorem imageToKernel_epi_comp {Z : V} (h : Z ⟶ A) [Epi h] (w) :
imageToKernel (h ≫ f) g w =
Subobject.ofLE _ _ (imageSubobject_comp_le h f) ≫
imageToKernel f g ((cancel_epi h).mp (by simpa using w : h ≫ f ≫ g = h ≫ 0)) := by
ext
simp
#align image_to_kernel_epi_comp imageToKernel_epi_comp
end
@[simp]
theorem imageToKernel_comp_hom_inv_comp [HasEqualizers V] [HasImages V] {Z : V} {i : B ≅ Z} (w) :
imageToKernel (f ≫ i.hom) (i.inv ≫ g) w =
(imageSubobjectCompIso _ _).hom ≫
imageToKernel f g (by simpa using w) ≫ (kernelSubobjectIsoComp i.inv g).inv := by
ext
simp
#align image_to_kernel_comp_hom_inv_comp imageToKernel_comp_hom_inv_comp
open ZeroObject
instance imageToKernel_epi_of_zero_of_mono [HasKernels V] [HasZeroObject V] [Mono g] :
Epi (imageToKernel (0 : A ⟶ B) g (by simp)) :=
epi_of_target_iso_zero _ (kernelSubobjectIso g ≪≫ kernel.ofMono g)
#align image_to_kernel_epi_of_zero_of_mono imageToKernel_epi_of_zero_of_mono
instance imageToKernel_epi_of_epi_of_zero [HasImages V] [Epi f] :
Epi (imageToKernel f (0 : B ⟶ C) (by simp)) := by
simp only [imageToKernel_zero_right]
haveI := epi_image_of_epi f
rw [← imageSubobject_arrow]
exact @epi_comp _ _ _ _ _ _ (epi_comp _ _) _ _
#align image_to_kernel_epi_of_epi_of_zero imageToKernel_epi_of_epi_of_zero
end
section
variable {A B C : V} (f : A ⟶ B) [HasImage f] (g : B ⟶ C) [HasKernel g]
def homology' {A B C : V} (f : A ⟶ B) [HasImage f] (g : B ⟶ C) [HasKernel g] (w : f ≫ g = 0)
[HasCokernel (imageToKernel f g w)] : V :=
cokernel (imageToKernel f g w)
#align homology homology'
section
variable (w : f ≫ g = 0) [HasCokernel (imageToKernel f g w)]
def homology'.π : (kernelSubobject g : V) ⟶ homology' f g w :=
cokernel.π _
#align homology.π homology'.π
@[simp]
theorem homology'.condition : imageToKernel f g w ≫ homology'.π f g w = 0 :=
cokernel.condition _
#align homology.condition homology'.condition
def homology'.desc {D : V} (k : (kernelSubobject g : V) ⟶ D) (p : imageToKernel f g w ≫ k = 0) :
homology' f g w ⟶ D :=
cokernel.desc _ k p
#align homology.desc homology'.desc
-- Porting note: removed elementwise attribute which does not seem to be helpful here
@[reassoc (attr := simp)]
theorem homology'.π_desc {D : V} (k : (kernelSubobject g : V) ⟶ D)
(p : imageToKernel f g w ≫ k = 0) : homology'.π f g w ≫ homology'.desc f g w k p = k := by
simp [homology'.π, homology'.desc]
#align homology.π_desc homology'.π_desc
@[ext]
theorem homology'.ext {D : V} {k k' : homology' f g w ⟶ D}
(p : homology'.π f g w ≫ k = homology'.π f g w ≫ k') : k = k' :=
coequalizer.hom_ext p
#align homology.ext homology'.ext
def homology'OfZeroRight [HasCokernel (imageToKernel f (0 : B ⟶ C) comp_zero)] [HasCokernel f]
[HasCokernel (image.ι f)] [Epi (factorThruImage f)] :
homology' f (0 : B ⟶ C) comp_zero ≅ cokernel f :=
(cokernel.mapIso _ _ (imageSubobjectIso _) ((kernelSubobjectIso 0).trans kernelZeroIsoSource)
(by simp)).trans
(cokernelImageι _)
#align homology_of_zero_right homology'OfZeroRight
def homology'OfZeroLeft [HasZeroObject V] [HasKernels V] [HasImage (0 : A ⟶ B)]
[HasCokernel (imageToKernel (0 : A ⟶ B) g zero_comp)] :
homology' (0 : A ⟶ B) g zero_comp ≅ kernel g :=
((cokernelIsoOfEq <| imageToKernel_zero_left _).trans cokernelZeroIsoTarget).trans
(kernelSubobjectIso _)
#align homology_of_zero_left homology'OfZeroLeft
@[simps]
def homology'ZeroZero [HasZeroObject V] [HasImage (0 : A ⟶ B)]
[HasCokernel (imageToKernel (0 : A ⟶ B) (0 : B ⟶ C) zero_comp)] :
homology' (0 : A ⟶ B) (0 : B ⟶ C) zero_comp ≅ B where
hom := homology'.desc (0 : A ⟶ B) (0 : B ⟶ C) zero_comp (kernelSubobject 0).arrow (by simp)
inv := inv (kernelSubobject 0).arrow ≫ homology'.π _ _ _
#align homology_zero_zero homology'ZeroZero
end
section
variable {f g} (w : f ≫ g = 0) {A' B' C' : V} {f' : A' ⟶ B'} [HasImage f'] {g' : B' ⟶ C'}
[HasKernel g'] (w' : f' ≫ g' = 0) (α : Arrow.mk f ⟶ Arrow.mk f') [HasImageMap α]
(β : Arrow.mk g ⟶ Arrow.mk g') {A₁ B₁ C₁ : V} {f₁ : A₁ ⟶ B₁} [HasImage f₁] {g₁ : B₁ ⟶ C₁}
[HasKernel g₁] (w₁ : f₁ ≫ g₁ = 0) {A₂ B₂ C₂ : V} {f₂ : A₂ ⟶ B₂} [HasImage f₂] {g₂ : B₂ ⟶ C₂}
[HasKernel g₂] (w₂ : f₂ ≫ g₂ = 0) {A₃ B₃ C₃ : V} {f₃ : A₃ ⟶ B₃} [HasImage f₃] {g₃ : B₃ ⟶ C₃}
[HasKernel g₃] (w₃ : f₃ ≫ g₃ = 0) (α₁ : Arrow.mk f₁ ⟶ Arrow.mk f₂) [HasImageMap α₁]
(β₁ : Arrow.mk g₁ ⟶ Arrow.mk g₂) (α₂ : Arrow.mk f₂ ⟶ Arrow.mk f₃) [HasImageMap α₂]
(β₂ : Arrow.mk g₂ ⟶ Arrow.mk g₃)
@[reassoc]
theorem imageSubobjectMap_comp_imageToKernel (p : α.right = β.left) :
imageToKernel f g w ≫ kernelSubobjectMap β = imageSubobjectMap α ≫ imageToKernel f' g' w' := by
ext
simp [p]
#align image_subobject_map_comp_image_to_kernel imageSubobjectMap_comp_imageToKernel
variable [HasCokernel (imageToKernel f g w)] [HasCokernel (imageToKernel f' g' w')]
variable [HasCokernel (imageToKernel f₁ g₁ w₁)]
variable [HasCokernel (imageToKernel f₂ g₂ w₂)]
variable [HasCokernel (imageToKernel f₃ g₃ w₃)]
def homology'.map (p : α.right = β.left) : homology' f g w ⟶ homology' f' g' w' :=
cokernel.desc _ (kernelSubobjectMap β ≫ cokernel.π _) <| by
rw [imageSubobjectMap_comp_imageToKernel_assoc w w' α β p]
simp only [cokernel.condition, comp_zero]
#align homology.map homology'.map
-- Porting note: removed elementwise attribute which does not seem to be helpful here,
-- the correct lemma is stated below
@[reassoc (attr := simp)]
theorem homology'.π_map (p : α.right = β.left) :
homology'.π f g w ≫ homology'.map w w' α β p =
kernelSubobjectMap β ≫ homology'.π f' g' w' := by
simp only [homology'.π, homology'.map, cokernel.π_desc]
#align homology.π_map homology'.π_map
section
attribute [local instance] ConcreteCategory.instFunLike
@[simp]
lemma homology'.π_map_apply [ConcreteCategory.{w} V] (p : α.right = β.left)
(x : (forget V).obj (Subobject.underlying.obj (kernelSubobject g))) :
homology'.map w w' α β p (homology'.π f g w x) =
homology'.π f' g' w' (kernelSubobjectMap β x) := by
simp only [← comp_apply, homology'.π_map w w' α β p]
end
@[reassoc (attr := simp), elementwise (attr := simp)]
theorem homology'.map_desc (p : α.right = β.left) {D : V} (k : (kernelSubobject g' : V) ⟶ D)
(z : imageToKernel f' g' w' ≫ k = 0) :
homology'.map w w' α β p ≫ homology'.desc f' g' w' k z =
homology'.desc f g w (kernelSubobjectMap β ≫ k)
(by simp only [imageSubobjectMap_comp_imageToKernel_assoc w w' α β p, z, comp_zero]) := by
ext
simp only [homology'.π_desc, homology'.π_map_assoc]
#align homology.map_desc homology'.map_desc
@[simp]
| Mathlib/Algebra/Homology/ImageToKernel.lean | 324 | 326 | theorem homology'.map_id : homology'.map w w (𝟙 _) (𝟙 _) rfl = 𝟙 _ := by |
ext
simp only [homology'.π_map, kernelSubobjectMap_id, Category.id_comp, Category.comp_id]
|
import Mathlib.Algebra.Polynomial.AlgebraMap
import Mathlib.Data.Complex.Exponential
import Mathlib.Data.Complex.Module
import Mathlib.RingTheory.Polynomial.Chebyshev
#align_import analysis.special_functions.trigonometric.chebyshev from "leanprover-community/mathlib"@"2c1d8ca2812b64f88992a5294ea3dba144755cd1"
set_option linter.uppercaseLean3 false
namespace Polynomial.Chebyshev
open Polynomial
variable {R A : Type*} [CommRing R] [CommRing A] [Algebra R A]
@[simp]
theorem aeval_T (x : A) (n : ℤ) : aeval x (T R n) = (T A n).eval x := by
rw [aeval_def, eval₂_eq_eval_map, map_T]
#align polynomial.chebyshev.aeval_T Polynomial.Chebyshev.aeval_T
@[simp]
theorem aeval_U (x : A) (n : ℤ) : aeval x (U R n) = (U A n).eval x := by
rw [aeval_def, eval₂_eq_eval_map, map_U]
#align polynomial.chebyshev.aeval_U Polynomial.Chebyshev.aeval_U
@[simp]
theorem algebraMap_eval_T (x : R) (n : ℤ) :
algebraMap R A ((T R n).eval x) = (T A n).eval (algebraMap R A x) := by
rw [← aeval_algebraMap_apply_eq_algebraMap_eval, aeval_T]
#align polynomial.chebyshev.algebra_map_eval_T Polynomial.Chebyshev.algebraMap_eval_T
@[simp]
theorem algebraMap_eval_U (x : R) (n : ℤ) :
algebraMap R A ((U R n).eval x) = (U A n).eval (algebraMap R A x) := by
rw [← aeval_algebraMap_apply_eq_algebraMap_eval, aeval_U]
#align polynomial.chebyshev.algebra_map_eval_U Polynomial.Chebyshev.algebraMap_eval_U
-- Porting note: added type ascriptions to the statement
@[simp, norm_cast]
theorem complex_ofReal_eval_T : ∀ (x : ℝ) n, (((T ℝ n).eval x : ℝ) : ℂ) = (T ℂ n).eval (x : ℂ) :=
@algebraMap_eval_T ℝ ℂ _ _ _
#align polynomial.chebyshev.complex_of_real_eval_T Polynomial.Chebyshev.complex_ofReal_eval_T
-- Porting note: added type ascriptions to the statement
@[simp, norm_cast]
theorem complex_ofReal_eval_U : ∀ (x : ℝ) n, (((U ℝ n).eval x : ℝ) : ℂ) = (U ℂ n).eval (x : ℂ) :=
@algebraMap_eval_U ℝ ℂ _ _ _
#align polynomial.chebyshev.complex_of_real_eval_U Polynomial.Chebyshev.complex_ofReal_eval_U
section Complex
open Complex
variable (θ : ℂ)
@[simp]
| Mathlib/Analysis/SpecialFunctions/Trigonometric/Chebyshev.lean | 73 | 86 | theorem T_complex_cos (n : ℤ) : (T ℂ n).eval (cos θ) = cos (n * θ) := by |
induction n using Polynomial.Chebyshev.induct with
| zero => simp
| one => simp
| add_two n ih1 ih2 =>
simp only [T_add_two, eval_sub, eval_mul, eval_X, eval_ofNat, ih1, ih2, sub_eq_iff_eq_add,
cos_add_cos]
push_cast
ring_nf
| neg_add_one n ih1 ih2 =>
simp only [T_sub_one, eval_sub, eval_mul, eval_X, eval_ofNat, ih1, ih2, sub_eq_iff_eq_add',
cos_add_cos]
push_cast
ring_nf
|
import Mathlib.Analysis.SpecialFunctions.Pow.NNReal
import Mathlib.Analysis.SpecialFunctions.Pow.Continuity
import Mathlib.Analysis.SumOverResidueClass
#align_import analysis.p_series from "leanprover-community/mathlib"@"0b9eaaa7686280fad8cce467f5c3c57ee6ce77f8"
def SuccDiffBounded (C : ℕ) (u : ℕ → ℕ) : Prop :=
∀ n : ℕ, u (n + 2) - u (n + 1) ≤ C • (u (n + 1) - u n)
namespace Finset
variable {M : Type*} [OrderedAddCommMonoid M] {f : ℕ → M} {u : ℕ → ℕ}
theorem le_sum_schlomilch' (hf : ∀ ⦃m n⦄, 0 < m → m ≤ n → f n ≤ f m) (h_pos : ∀ n, 0 < u n)
(hu : Monotone u) (n : ℕ) :
(∑ k ∈ Ico (u 0) (u n), f k) ≤ ∑ k ∈ range n, (u (k + 1) - u k) • f (u k) := by
induction' n with n ihn
· simp
suffices (∑ k ∈ Ico (u n) (u (n + 1)), f k) ≤ (u (n + 1) - u n) • f (u n) by
rw [sum_range_succ, ← sum_Ico_consecutive]
· exact add_le_add ihn this
exacts [hu n.zero_le, hu n.le_succ]
have : ∀ k ∈ Ico (u n) (u (n + 1)), f k ≤ f (u n) := fun k hk =>
hf (Nat.succ_le_of_lt (h_pos n)) (mem_Ico.mp hk).1
convert sum_le_sum this
simp [pow_succ, mul_two]
| Mathlib/Analysis/PSeries.lean | 64 | 68 | theorem le_sum_condensed' (hf : ∀ ⦃m n⦄, 0 < m → m ≤ n → f n ≤ f m) (n : ℕ) :
(∑ k ∈ Ico 1 (2 ^ n), f k) ≤ ∑ k ∈ range n, 2 ^ k • f (2 ^ k) := by |
convert le_sum_schlomilch' hf (fun n => pow_pos zero_lt_two n)
(fun m n hm => pow_le_pow_right one_le_two hm) n using 2
simp [pow_succ, mul_two, two_mul]
|
import Mathlib.RingTheory.DedekindDomain.Ideal
#align_import number_theory.ramification_inertia from "leanprover-community/mathlib"@"039a089d2a4b93c761b234f3e5f5aeb752bac60f"
namespace Ideal
universe u v
variable {R : Type u} [CommRing R]
variable {S : Type v} [CommRing S] (f : R →+* S)
variable (p : Ideal R) (P : Ideal S)
open FiniteDimensional
open UniqueFactorizationMonoid
section DecEq
open scoped Classical
noncomputable def ramificationIdx : ℕ := sSup {n | map f p ≤ P ^ n}
#align ideal.ramification_idx Ideal.ramificationIdx
variable {f p P}
theorem ramificationIdx_eq_find (h : ∃ n, ∀ k, map f p ≤ P ^ k → k ≤ n) :
ramificationIdx f p P = Nat.find h :=
Nat.sSup_def h
#align ideal.ramification_idx_eq_find Ideal.ramificationIdx_eq_find
theorem ramificationIdx_eq_zero (h : ∀ n : ℕ, ∃ k, map f p ≤ P ^ k ∧ n < k) :
ramificationIdx f p P = 0 :=
dif_neg (by push_neg; exact h)
#align ideal.ramification_idx_eq_zero Ideal.ramificationIdx_eq_zero
theorem ramificationIdx_spec {n : ℕ} (hle : map f p ≤ P ^ n) (hgt : ¬map f p ≤ P ^ (n + 1)) :
ramificationIdx f p P = n := by
let Q : ℕ → Prop := fun m => ∀ k : ℕ, map f p ≤ P ^ k → k ≤ m
have : Q n := by
intro k hk
refine le_of_not_lt fun hnk => ?_
exact hgt (hk.trans (Ideal.pow_le_pow_right hnk))
rw [ramificationIdx_eq_find ⟨n, this⟩]
refine le_antisymm (Nat.find_min' _ this) (le_of_not_gt fun h : Nat.find _ < n => ?_)
obtain this' := Nat.find_spec ⟨n, this⟩
exact h.not_le (this' _ hle)
#align ideal.ramification_idx_spec Ideal.ramificationIdx_spec
theorem ramificationIdx_lt {n : ℕ} (hgt : ¬map f p ≤ P ^ n) : ramificationIdx f p P < n := by
cases' n with n n
· simp at hgt
· rw [Nat.lt_succ_iff]
have : ∀ k, map f p ≤ P ^ k → k ≤ n := by
refine fun k hk => le_of_not_lt fun hnk => ?_
exact hgt (hk.trans (Ideal.pow_le_pow_right hnk))
rw [ramificationIdx_eq_find ⟨n, this⟩]
exact Nat.find_min' ⟨n, this⟩ this
#align ideal.ramification_idx_lt Ideal.ramificationIdx_lt
@[simp]
theorem ramificationIdx_bot : ramificationIdx f ⊥ P = 0 :=
dif_neg <| not_exists.mpr fun n hn => n.lt_succ_self.not_le (hn _ (by simp))
#align ideal.ramification_idx_bot Ideal.ramificationIdx_bot
@[simp]
theorem ramificationIdx_of_not_le (h : ¬map f p ≤ P) : ramificationIdx f p P = 0 :=
ramificationIdx_spec (by simp) (by simpa using h)
#align ideal.ramification_idx_of_not_le Ideal.ramificationIdx_of_not_le
| Mathlib/NumberTheory/RamificationInertia.lean | 116 | 118 | theorem ramificationIdx_ne_zero {e : ℕ} (he : e ≠ 0) (hle : map f p ≤ P ^ e)
(hnle : ¬map f p ≤ P ^ (e + 1)) : ramificationIdx f p P ≠ 0 := by |
rwa [ramificationIdx_spec hle hnle]
|
import Mathlib.Order.Interval.Multiset
#align_import data.nat.interval from "leanprover-community/mathlib"@"1d29de43a5ba4662dd33b5cfeecfc2a27a5a8a29"
-- TODO
-- assert_not_exists Ring
open Finset Nat
variable (a b c : ℕ)
namespace Nat
instance instLocallyFiniteOrder : LocallyFiniteOrder ℕ where
finsetIcc a b := ⟨List.range' a (b + 1 - a), List.nodup_range' _ _⟩
finsetIco a b := ⟨List.range' a (b - a), List.nodup_range' _ _⟩
finsetIoc a b := ⟨List.range' (a + 1) (b - a), List.nodup_range' _ _⟩
finsetIoo a b := ⟨List.range' (a + 1) (b - a - 1), List.nodup_range' _ _⟩
finset_mem_Icc a b x := by rw [Finset.mem_mk, Multiset.mem_coe, List.mem_range'_1]; omega
finset_mem_Ico a b x := by rw [Finset.mem_mk, Multiset.mem_coe, List.mem_range'_1]; omega
finset_mem_Ioc a b x := by rw [Finset.mem_mk, Multiset.mem_coe, List.mem_range'_1]; omega
finset_mem_Ioo a b x := by rw [Finset.mem_mk, Multiset.mem_coe, List.mem_range'_1]; omega
theorem Icc_eq_range' : Icc a b = ⟨List.range' a (b + 1 - a), List.nodup_range' _ _⟩ :=
rfl
#align nat.Icc_eq_range' Nat.Icc_eq_range'
theorem Ico_eq_range' : Ico a b = ⟨List.range' a (b - a), List.nodup_range' _ _⟩ :=
rfl
#align nat.Ico_eq_range' Nat.Ico_eq_range'
theorem Ioc_eq_range' : Ioc a b = ⟨List.range' (a + 1) (b - a), List.nodup_range' _ _⟩ :=
rfl
#align nat.Ioc_eq_range' Nat.Ioc_eq_range'
theorem Ioo_eq_range' : Ioo a b = ⟨List.range' (a + 1) (b - a - 1), List.nodup_range' _ _⟩ :=
rfl
#align nat.Ioo_eq_range' Nat.Ioo_eq_range'
theorem uIcc_eq_range' :
uIcc a b = ⟨List.range' (min a b) (max a b + 1 - min a b), List.nodup_range' _ _⟩ := rfl
#align nat.uIcc_eq_range' Nat.uIcc_eq_range'
theorem Iio_eq_range : Iio = range := by
ext b x
rw [mem_Iio, mem_range]
#align nat.Iio_eq_range Nat.Iio_eq_range
@[simp]
theorem Ico_zero_eq_range : Ico 0 = range := by rw [← Nat.bot_eq_zero, ← Iio_eq_Ico, Iio_eq_range]
#align nat.Ico_zero_eq_range Nat.Ico_zero_eq_range
lemma range_eq_Icc_zero_sub_one (n : ℕ) (hn : n ≠ 0): range n = Icc 0 (n - 1) := by
ext b
simp_all only [mem_Icc, zero_le, true_and, mem_range]
exact lt_iff_le_pred (zero_lt_of_ne_zero hn)
theorem _root_.Finset.range_eq_Ico : range = Ico 0 :=
Ico_zero_eq_range.symm
#align finset.range_eq_Ico Finset.range_eq_Ico
@[simp]
theorem card_Icc : (Icc a b).card = b + 1 - a :=
List.length_range' _ _ _
#align nat.card_Icc Nat.card_Icc
@[simp]
theorem card_Ico : (Ico a b).card = b - a :=
List.length_range' _ _ _
#align nat.card_Ico Nat.card_Ico
@[simp]
theorem card_Ioc : (Ioc a b).card = b - a :=
List.length_range' _ _ _
#align nat.card_Ioc Nat.card_Ioc
@[simp]
theorem card_Ioo : (Ioo a b).card = b - a - 1 :=
List.length_range' _ _ _
#align nat.card_Ioo Nat.card_Ioo
@[simp]
theorem card_uIcc : (uIcc a b).card = (b - a : ℤ).natAbs + 1 :=
(card_Icc _ _).trans $ by rw [← Int.natCast_inj, sup_eq_max, inf_eq_min, Int.ofNat_sub] <;> omega
#align nat.card_uIcc Nat.card_uIcc
@[simp]
lemma card_Iic : (Iic b).card = b + 1 := by rw [Iic_eq_Icc, card_Icc, Nat.bot_eq_zero, Nat.sub_zero]
#align nat.card_Iic Nat.card_Iic
@[simp]
theorem card_Iio : (Iio b).card = b := by rw [Iio_eq_Ico, card_Ico, Nat.bot_eq_zero, Nat.sub_zero]
#align nat.card_Iio Nat.card_Iio
-- Porting note (#10618): simp can prove this
-- @[simp]
theorem card_fintypeIcc : Fintype.card (Set.Icc a b) = b + 1 - a := by
rw [Fintype.card_ofFinset, card_Icc]
#align nat.card_fintype_Icc Nat.card_fintypeIcc
-- Porting note (#10618): simp can prove this
-- @[simp]
theorem card_fintypeIco : Fintype.card (Set.Ico a b) = b - a := by
rw [Fintype.card_ofFinset, card_Ico]
#align nat.card_fintype_Ico Nat.card_fintypeIco
-- Porting note (#10618): simp can prove this
-- @[simp]
theorem card_fintypeIoc : Fintype.card (Set.Ioc a b) = b - a := by
rw [Fintype.card_ofFinset, card_Ioc]
#align nat.card_fintype_Ioc Nat.card_fintypeIoc
-- Porting note (#10618): simp can prove this
-- @[simp]
theorem card_fintypeIoo : Fintype.card (Set.Ioo a b) = b - a - 1 := by
rw [Fintype.card_ofFinset, card_Ioo]
#align nat.card_fintype_Ioo Nat.card_fintypeIoo
-- Porting note (#10618): simp can prove this
-- @[simp]
theorem card_fintypeIic : Fintype.card (Set.Iic b) = b + 1 := by
rw [Fintype.card_ofFinset, card_Iic]
#align nat.card_fintype_Iic Nat.card_fintypeIic
-- Porting note (#10618): simp can prove this
-- @[simp]
theorem card_fintypeIio : Fintype.card (Set.Iio b) = b := by rw [Fintype.card_ofFinset, card_Iio]
#align nat.card_fintype_Iio Nat.card_fintypeIio
-- TODO@Yaël: Generalize all the following lemmas to `SuccOrder`
theorem Icc_succ_left : Icc a.succ b = Ioc a b := by
ext x
rw [mem_Icc, mem_Ioc, succ_le_iff]
#align nat.Icc_succ_left Nat.Icc_succ_left
theorem Ico_succ_right : Ico a b.succ = Icc a b := by
ext x
rw [mem_Ico, mem_Icc, Nat.lt_succ_iff]
#align nat.Ico_succ_right Nat.Ico_succ_right
theorem Ico_succ_left : Ico a.succ b = Ioo a b := by
ext x
rw [mem_Ico, mem_Ioo, succ_le_iff]
#align nat.Ico_succ_left Nat.Ico_succ_left
theorem Icc_pred_right {b : ℕ} (h : 0 < b) : Icc a (b - 1) = Ico a b := by
ext x
rw [mem_Icc, mem_Ico, lt_iff_le_pred h]
#align nat.Icc_pred_right Nat.Icc_pred_right
theorem Ico_succ_succ : Ico a.succ b.succ = Ioc a b := by
ext x
rw [mem_Ico, mem_Ioc, succ_le_iff, Nat.lt_succ_iff]
#align nat.Ico_succ_succ Nat.Ico_succ_succ
@[simp]
theorem Ico_succ_singleton : Ico a (a + 1) = {a} := by rw [Ico_succ_right, Icc_self]
#align nat.Ico_succ_singleton Nat.Ico_succ_singleton
@[simp]
theorem Ico_pred_singleton {a : ℕ} (h : 0 < a) : Ico (a - 1) a = {a - 1} := by
rw [← Icc_pred_right _ h, Icc_self]
#align nat.Ico_pred_singleton Nat.Ico_pred_singleton
@[simp]
| Mathlib/Order/Interval/Finset/Nat.lean | 183 | 183 | theorem Ioc_succ_singleton : Ioc b (b + 1) = {b + 1} := by | rw [← Nat.Icc_succ_left, Icc_self]
|
import Mathlib.Algebra.Group.Subgroup.Finite
import Mathlib.Data.Finset.Fin
import Mathlib.Data.Finset.Sort
import Mathlib.Data.Int.Order.Units
import Mathlib.GroupTheory.Perm.Support
import Mathlib.Logic.Equiv.Fin
import Mathlib.Tactic.NormNum.Ineq
#align_import group_theory.perm.sign from "leanprover-community/mathlib"@"f694c7dead66f5d4c80f446c796a5aad14707f0e"
universe u v
open Equiv Function Fintype Finset
variable {α : Type u} [DecidableEq α] {β : Type v}
namespace Equiv.Perm
def modSwap (i j : α) : Setoid (Perm α) :=
⟨fun σ τ => σ = τ ∨ σ = swap i j * τ, fun σ => Or.inl (refl σ), fun {σ τ} h =>
Or.casesOn h (fun h => Or.inl h.symm) fun h => Or.inr (by rw [h, swap_mul_self_mul]),
fun {σ τ υ} hστ hτυ => by
cases' hστ with hστ hστ <;> cases' hτυ with hτυ hτυ <;> try rw [hστ, hτυ, swap_mul_self_mul] <;>
simp [hστ, hτυ] -- Porting note: should close goals, but doesn't
· simp [hστ, hτυ]
· simp [hστ, hτυ]
· simp [hστ, hτυ]⟩
#align equiv.perm.mod_swap Equiv.Perm.modSwap
noncomputable instance {α : Type*} [Fintype α] [DecidableEq α] (i j : α) :
DecidableRel (modSwap i j).r :=
fun _ _ => Or.decidable
def swapFactorsAux :
∀ (l : List α) (f : Perm α),
(∀ {x}, f x ≠ x → x ∈ l) → { l : List (Perm α) // l.prod = f ∧ ∀ g ∈ l, IsSwap g }
| [] => fun f h =>
⟨[],
Equiv.ext fun x => by
rw [List.prod_nil]
exact (Classical.not_not.1 (mt h (List.not_mem_nil _))).symm,
by simp⟩
| x::l => fun f h =>
if hfx : x = f x then
swapFactorsAux l f fun {y} hy =>
List.mem_of_ne_of_mem (fun h : y = x => by simp [h, hfx.symm] at hy) (h hy)
else
let m :=
swapFactorsAux l (swap x (f x) * f) fun {y} hy =>
have : f y ≠ y ∧ y ≠ x := ne_and_ne_of_swap_mul_apply_ne_self hy
List.mem_of_ne_of_mem this.2 (h this.1)
⟨swap x (f x)::m.1, by
rw [List.prod_cons, m.2.1, ← mul_assoc, mul_def (swap x (f x)), swap_swap, ← one_def,
one_mul],
fun {g} hg => ((List.mem_cons).1 hg).elim (fun h => ⟨x, f x, hfx, h⟩) (m.2.2 _)⟩
#align equiv.perm.swap_factors_aux Equiv.Perm.swapFactorsAux
def swapFactors [Fintype α] [LinearOrder α] (f : Perm α) :
{ l : List (Perm α) // l.prod = f ∧ ∀ g ∈ l, IsSwap g } :=
swapFactorsAux ((@univ α _).sort (· ≤ ·)) f fun {_ _} => (mem_sort _).2 (mem_univ _)
#align equiv.perm.swap_factors Equiv.Perm.swapFactors
def truncSwapFactors [Fintype α] (f : Perm α) :
Trunc { l : List (Perm α) // l.prod = f ∧ ∀ g ∈ l, IsSwap g } :=
Quotient.recOnSubsingleton (@univ α _).1 (fun l h => Trunc.mk (swapFactorsAux l f (h _)))
(show ∀ x, f x ≠ x → x ∈ (@univ α _).1 from fun _ _ => mem_univ _)
#align equiv.perm.trunc_swap_factors Equiv.Perm.truncSwapFactors
@[elab_as_elim]
theorem swap_induction_on [Finite α] {P : Perm α → Prop} (f : Perm α) :
P 1 → (∀ f x y, x ≠ y → P f → P (swap x y * f)) → P f := by
cases nonempty_fintype α
cases' (truncSwapFactors f).out with l hl
induction' l with g l ih generalizing f
· simp (config := { contextual := true }) only [hl.left.symm, List.prod_nil, forall_true_iff]
· intro h1 hmul_swap
rcases hl.2 g (by simp) with ⟨x, y, hxy⟩
rw [← hl.1, List.prod_cons, hxy.2]
exact
hmul_swap _ _ _ hxy.1
(ih _ ⟨rfl, fun v hv => hl.2 _ (List.mem_cons_of_mem _ hv)⟩ h1 hmul_swap)
#align equiv.perm.swap_induction_on Equiv.Perm.swap_induction_on
theorem closure_isSwap [Finite α] : Subgroup.closure { σ : Perm α | IsSwap σ } = ⊤ := by
cases nonempty_fintype α
refine eq_top_iff.mpr fun x _ => ?_
obtain ⟨h1, h2⟩ := Subtype.mem (truncSwapFactors x).out
rw [← h1]
exact Subgroup.list_prod_mem _ fun y hy => Subgroup.subset_closure (h2 y hy)
#align equiv.perm.closure_is_swap Equiv.Perm.closure_isSwap
@[elab_as_elim]
theorem swap_induction_on' [Finite α] {P : Perm α → Prop} (f : Perm α) :
P 1 → (∀ f x y, x ≠ y → P f → P (f * swap x y)) → P f := fun h1 IH =>
inv_inv f ▸ swap_induction_on f⁻¹ h1 fun f => IH f⁻¹
#align equiv.perm.swap_induction_on' Equiv.Perm.swap_induction_on'
theorem isConj_swap {w x y z : α} (hwx : w ≠ x) (hyz : y ≠ z) : IsConj (swap w x) (swap y z) :=
isConj_iff.2
(have h :
∀ {y z : α},
y ≠ z → w ≠ z → swap w y * swap x z * swap w x * (swap w y * swap x z)⁻¹ = swap y z :=
fun {y z} hyz hwz => by
rw [mul_inv_rev, swap_inv, swap_inv, mul_assoc (swap w y), mul_assoc (swap w y), ←
mul_assoc _ (swap x z), swap_mul_swap_mul_swap hwx hwz, ← mul_assoc,
swap_mul_swap_mul_swap hwz.symm hyz.symm]
if hwz : w = z then
have hwy : w ≠ y := by rw [hwz]; exact hyz.symm
⟨swap w z * swap x y, by rw [swap_comm y z, h hyz.symm hwy]⟩
else ⟨swap w y * swap x z, h hyz hwz⟩)
#align equiv.perm.is_conj_swap Equiv.Perm.isConj_swap
def finPairsLT (n : ℕ) : Finset (Σ_ : Fin n, Fin n) :=
(univ : Finset (Fin n)).sigma fun a => (range a).attachFin fun _ hm => (mem_range.1 hm).trans a.2
#align equiv.perm.fin_pairs_lt Equiv.Perm.finPairsLT
theorem mem_finPairsLT {n : ℕ} {a : Σ_ : Fin n, Fin n} : a ∈ finPairsLT n ↔ a.2 < a.1 := by
simp only [finPairsLT, Fin.lt_iff_val_lt_val, true_and_iff, mem_attachFin, mem_range, mem_univ,
mem_sigma]
#align equiv.perm.mem_fin_pairs_lt Equiv.Perm.mem_finPairsLT
def signAux {n : ℕ} (a : Perm (Fin n)) : ℤˣ :=
∏ x ∈ finPairsLT n, if a x.1 ≤ a x.2 then -1 else 1
#align equiv.perm.sign_aux Equiv.Perm.signAux
@[simp]
theorem signAux_one (n : ℕ) : signAux (1 : Perm (Fin n)) = 1 := by
unfold signAux
conv => rhs; rw [← @Finset.prod_const_one _ _ (finPairsLT n)]
exact Finset.prod_congr rfl fun a ha => if_neg (mem_finPairsLT.1 ha).not_le
#align equiv.perm.sign_aux_one Equiv.Perm.signAux_one
def signBijAux {n : ℕ} (f : Perm (Fin n)) (a : Σ_ : Fin n, Fin n) : Σ_ : Fin n, Fin n :=
if _ : f a.2 < f a.1 then ⟨f a.1, f a.2⟩ else ⟨f a.2, f a.1⟩
#align equiv.perm.sign_bij_aux Equiv.Perm.signBijAux
theorem signBijAux_injOn {n : ℕ} {f : Perm (Fin n)} :
(finPairsLT n : Set (Σ _, Fin n)).InjOn (signBijAux f) := by
rintro ⟨a₁, a₂⟩ ha ⟨b₁, b₂⟩ hb h
dsimp [signBijAux] at h
rw [Finset.mem_coe, mem_finPairsLT] at *
have : ¬b₁ < b₂ := hb.le.not_lt
split_ifs at h <;>
simp_all [(Equiv.injective f).eq_iff, eq_self_iff_true, and_self_iff, heq_iff_eq]
· exact absurd this (not_le.mpr ha)
· exact absurd this (not_le.mpr ha)
#align equiv.perm.sign_bij_aux_inj Equiv.Perm.signBijAux_injOn
theorem signBijAux_surj {n : ℕ} {f : Perm (Fin n)} :
∀ a ∈ finPairsLT n, ∃ b ∈ finPairsLT n, signBijAux f b = a :=
fun ⟨a₁, a₂⟩ ha =>
if hxa : f⁻¹ a₂ < f⁻¹ a₁ then
⟨⟨f⁻¹ a₁, f⁻¹ a₂⟩, mem_finPairsLT.2 hxa, by
dsimp [signBijAux]
rw [apply_inv_self, apply_inv_self, if_pos (mem_finPairsLT.1 ha)]⟩
else
⟨⟨f⁻¹ a₂, f⁻¹ a₁⟩,
mem_finPairsLT.2 <|
(le_of_not_gt hxa).lt_of_ne fun h => by
simp [mem_finPairsLT, f⁻¹.injective h, lt_irrefl] at ha, by
dsimp [signBijAux]
rw [apply_inv_self, apply_inv_self, if_neg (mem_finPairsLT.1 ha).le.not_lt]⟩
#align equiv.perm.sign_bij_aux_surj Equiv.Perm.signBijAux_surj
theorem signBijAux_mem {n : ℕ} {f : Perm (Fin n)} :
∀ a : Σ_ : Fin n, Fin n, a ∈ finPairsLT n → signBijAux f a ∈ finPairsLT n :=
fun ⟨a₁, a₂⟩ ha => by
unfold signBijAux
split_ifs with h
· exact mem_finPairsLT.2 h
· exact mem_finPairsLT.2
((le_of_not_gt h).lt_of_ne fun h => (mem_finPairsLT.1 ha).ne (f.injective h.symm))
#align equiv.perm.sign_bij_aux_mem Equiv.Perm.signBijAux_mem
@[simp]
theorem signAux_inv {n : ℕ} (f : Perm (Fin n)) : signAux f⁻¹ = signAux f :=
prod_nbij (signBijAux f⁻¹) signBijAux_mem signBijAux_injOn signBijAux_surj fun ⟨a, b⟩ hab ↦
if h : f⁻¹ b < f⁻¹ a then by
simp_all [signBijAux, dif_pos h, if_neg h.not_le, apply_inv_self, apply_inv_self,
if_neg (mem_finPairsLT.1 hab).not_le]
else by
simp_all [signBijAux, if_pos (le_of_not_gt h), dif_neg h, apply_inv_self, apply_inv_self,
if_pos (mem_finPairsLT.1 hab).le]
#align equiv.perm.sign_aux_inv Equiv.Perm.signAux_inv
theorem signAux_mul {n : ℕ} (f g : Perm (Fin n)) : signAux (f * g) = signAux f * signAux g := by
rw [← signAux_inv g]
unfold signAux
rw [← prod_mul_distrib]
refine prod_nbij (signBijAux g) signBijAux_mem signBijAux_injOn signBijAux_surj ?_
rintro ⟨a, b⟩ hab
dsimp only [signBijAux]
rw [mul_apply, mul_apply]
rw [mem_finPairsLT] at hab
by_cases h : g b < g a
· rw [dif_pos h]
simp only [not_le_of_gt hab, mul_one, mul_ite, mul_neg, Perm.inv_apply_self, if_false]
· rw [dif_neg h, inv_apply_self, inv_apply_self, if_pos hab.le]
by_cases h₁ : f (g b) ≤ f (g a)
· have : f (g b) ≠ f (g a) := by
rw [Ne, f.injective.eq_iff, g.injective.eq_iff]
exact ne_of_lt hab
rw [if_pos h₁, if_neg (h₁.lt_of_ne this).not_le]
rfl
· rw [if_neg h₁, if_pos (lt_of_not_ge h₁).le]
rfl
#align equiv.perm.sign_aux_mul Equiv.Perm.signAux_mul
private theorem signAux_swap_zero_one' (n : ℕ) : signAux (swap (0 : Fin (n + 2)) 1) = -1 :=
show _ = ∏ x ∈ {(⟨1, 0⟩ : Σ a : Fin (n + 2), Fin (n + 2))},
if (Equiv.swap 0 1) x.1 ≤ swap 0 1 x.2 then (-1 : ℤˣ) else 1 by
refine Eq.symm (prod_subset (fun ⟨x₁, x₂⟩ => by
simp (config := { contextual := true }) [mem_finPairsLT, Fin.one_pos]) fun a ha₁ ha₂ => ?_)
rcases a with ⟨a₁, a₂⟩
replace ha₁ : a₂ < a₁ := mem_finPairsLT.1 ha₁
dsimp only
rcases a₁.zero_le.eq_or_lt with (rfl | H)
· exact absurd a₂.zero_le ha₁.not_le
rcases a₂.zero_le.eq_or_lt with (rfl | H')
· simp only [and_true_iff, eq_self_iff_true, heq_iff_eq, mem_singleton, Sigma.mk.inj_iff] at ha₂
have : 1 < a₁ := lt_of_le_of_ne (Nat.succ_le_of_lt ha₁)
(Ne.symm (by intro h; apply ha₂; simp [h]))
have h01 : Equiv.swap (0 : Fin (n + 2)) 1 0 = 1 := by simp
rw [swap_apply_of_ne_of_ne (ne_of_gt H) ha₂, h01, if_neg this.not_le]
· have le : 1 ≤ a₂ := Nat.succ_le_of_lt H'
have lt : 1 < a₁ := le.trans_lt ha₁
have h01 : Equiv.swap (0 : Fin (n + 2)) 1 1 = 0 := by simp only [swap_apply_right]
rcases le.eq_or_lt with (rfl | lt')
· rw [swap_apply_of_ne_of_ne H.ne' lt.ne', h01, if_neg H.not_le]
· rw [swap_apply_of_ne_of_ne (ne_of_gt H) (ne_of_gt lt),
swap_apply_of_ne_of_ne (ne_of_gt H') (ne_of_gt lt'), if_neg ha₁.not_le]
private theorem signAux_swap_zero_one {n : ℕ} (hn : 2 ≤ n) :
signAux (swap (⟨0, lt_of_lt_of_le (by decide) hn⟩ : Fin n) ⟨1, lt_of_lt_of_le (by decide) hn⟩) =
-1 := by
rcases n with (_ | _ | n)
· norm_num at hn
· norm_num at hn
· exact signAux_swap_zero_one' n
theorem signAux_swap : ∀ {n : ℕ} {x y : Fin n} (_hxy : x ≠ y), signAux (swap x y) = -1
| 0, x, y => by intro; exact Fin.elim0 x
| 1, x, y => by
dsimp [signAux, swap, swapCore]
simp only [eq_iff_true_of_subsingleton, not_true, ite_true, le_refl, prod_const,
IsEmpty.forall_iff]
| n + 2, x, y => fun hxy => by
have h2n : 2 ≤ n + 2 := by exact le_add_self
rw [← isConj_iff_eq, ← signAux_swap_zero_one h2n]
exact (MonoidHom.mk' signAux signAux_mul).map_isConj
(isConj_swap hxy (by exact of_decide_eq_true rfl))
#align equiv.perm.sign_aux_swap Equiv.Perm.signAux_swap
def signAux2 : List α → Perm α → ℤˣ
| [], _ => 1
| x::l, f => if x = f x then signAux2 l f else -signAux2 l (swap x (f x) * f)
#align equiv.perm.sign_aux2 Equiv.Perm.signAux2
theorem signAux_eq_signAux2 {n : ℕ} :
∀ (l : List α) (f : Perm α) (e : α ≃ Fin n) (_h : ∀ x, f x ≠ x → x ∈ l),
signAux ((e.symm.trans f).trans e) = signAux2 l f
| [], f, e, h => by
have : f = 1 := Equiv.ext fun y => Classical.not_not.1 (mt (h y) (List.not_mem_nil _))
rw [this, one_def, Equiv.trans_refl, Equiv.symm_trans_self, ← one_def, signAux_one, signAux2]
| x::l, f, e, h => by
rw [signAux2]
by_cases hfx : x = f x
· rw [if_pos hfx]
exact
signAux_eq_signAux2 l f _ fun y (hy : f y ≠ y) =>
List.mem_of_ne_of_mem (fun h : y = x => by simp [h, hfx.symm] at hy) (h y hy)
· have hy : ∀ y : α, (swap x (f x) * f) y ≠ y → y ∈ l := fun y hy =>
have : f y ≠ y ∧ y ≠ x := ne_and_ne_of_swap_mul_apply_ne_self hy
List.mem_of_ne_of_mem this.2 (h _ this.1)
have : (e.symm.trans (swap x (f x) * f)).trans e =
swap (e x) (e (f x)) * (e.symm.trans f).trans e := by
ext
rw [← Equiv.symm_trans_swap_trans, mul_def, Equiv.symm_trans_swap_trans, mul_def]
repeat (rw [trans_apply])
simp [swap, swapCore]
split_ifs <;> rfl
have hefx : e x ≠ e (f x) := mt e.injective.eq_iff.1 hfx
rw [if_neg hfx, ← signAux_eq_signAux2 _ _ e hy, this, signAux_mul, signAux_swap hefx]
simp only [neg_neg, one_mul, neg_mul]
#align equiv.perm.sign_aux_eq_sign_aux2 Equiv.Perm.signAux_eq_signAux2
def signAux3 [Finite α] (f : Perm α) {s : Multiset α} : (∀ x, x ∈ s) → ℤˣ :=
Quotient.hrecOn s (fun l _ => signAux2 l f) fun l₁ l₂ h ↦ by
rcases Finite.exists_equiv_fin α with ⟨n, ⟨e⟩⟩
refine Function.hfunext (forall_congr fun _ ↦ propext h.mem_iff) fun h₁ h₂ _ ↦ ?_
rw [← signAux_eq_signAux2 _ _ e fun _ _ => h₁ _, ← signAux_eq_signAux2 _ _ e fun _ _ => h₂ _]
#align equiv.perm.sign_aux3 Equiv.Perm.signAux3
theorem signAux3_mul_and_swap [Finite α] (f g : Perm α) (s : Multiset α) (hs : ∀ x, x ∈ s) :
signAux3 (f * g) hs = signAux3 f hs * signAux3 g hs ∧
Pairwise fun x y => signAux3 (swap x y) hs = -1 := by
obtain ⟨n, ⟨e⟩⟩ := Finite.exists_equiv_fin α
induction s using Quotient.inductionOn with | _ l => ?_
show
signAux2 l (f * g) = signAux2 l f * signAux2 l g ∧
Pairwise fun x y => signAux2 l (swap x y) = -1
have hfg : (e.symm.trans (f * g)).trans e = (e.symm.trans f).trans e * (e.symm.trans g).trans e :=
Equiv.ext fun h => by simp [mul_apply]
constructor
· rw [← signAux_eq_signAux2 _ _ e fun _ _ => hs _, ←
signAux_eq_signAux2 _ _ e fun _ _ => hs _, ← signAux_eq_signAux2 _ _ e fun _ _ => hs _,
hfg, signAux_mul]
· intro x y hxy
rw [← e.injective.ne_iff] at hxy
rw [← signAux_eq_signAux2 _ _ e fun _ _ => hs _, symm_trans_swap_trans, signAux_swap hxy]
#align equiv.perm.sign_aux3_mul_and_swap Equiv.Perm.signAux3_mul_and_swap
| Mathlib/GroupTheory/Perm/Sign.lean | 354 | 364 | theorem signAux3_symm_trans_trans [Finite α] [DecidableEq β] [Finite β] (f : Perm α) (e : α ≃ β)
{s : Multiset α} {t : Multiset β} (hs : ∀ x, x ∈ s) (ht : ∀ x, x ∈ t) :
signAux3 ((e.symm.trans f).trans e) ht = signAux3 f hs := by |
-- Porting note: switched from term mode to tactic mode
induction' t, s using Quotient.inductionOn₂ with t s ht hs
show signAux2 _ _ = signAux2 _ _
rcases Finite.exists_equiv_fin β with ⟨n, ⟨e'⟩⟩
rw [← signAux_eq_signAux2 _ _ e' fun _ _ => ht _,
← signAux_eq_signAux2 _ _ (e.trans e') fun _ _ => hs _]
exact congr_arg signAux
(Equiv.ext fun x => by simp [Equiv.coe_trans, apply_eq_iff_eq, symm_trans_apply])
|
import Mathlib.Algebra.Algebra.Quasispectrum
import Mathlib.FieldTheory.IsAlgClosed.Spectrum
import Mathlib.Analysis.Complex.Liouville
import Mathlib.Analysis.Complex.Polynomial
import Mathlib.Analysis.Analytic.RadiusLiminf
import Mathlib.Topology.Algebra.Module.CharacterSpace
import Mathlib.Analysis.NormedSpace.Exponential
import Mathlib.Analysis.NormedSpace.UnitizationL1
#align_import analysis.normed_space.spectrum from "leanprover-community/mathlib"@"d608fc5d4e69d4cc21885913fb573a88b0deb521"
open scoped ENNReal NNReal
open NormedSpace -- For `NormedSpace.exp`.
noncomputable def spectralRadius (𝕜 : Type*) {A : Type*} [NormedField 𝕜] [Ring A] [Algebra 𝕜 A]
(a : A) : ℝ≥0∞ :=
⨆ k ∈ spectrum 𝕜 a, ‖k‖₊
#align spectral_radius spectralRadius
variable {𝕜 : Type*} {A : Type*}
namespace spectrum
section SpectrumCompact
open Filter
variable [NormedField 𝕜] [NormedRing A] [NormedAlgebra 𝕜 A]
local notation "σ" => spectrum 𝕜
local notation "ρ" => resolventSet 𝕜
local notation "↑ₐ" => algebraMap 𝕜 A
@[simp]
theorem SpectralRadius.of_subsingleton [Subsingleton A] (a : A) : spectralRadius 𝕜 a = 0 := by
simp [spectralRadius]
#align spectrum.spectral_radius.of_subsingleton spectrum.SpectralRadius.of_subsingleton
@[simp]
theorem spectralRadius_zero : spectralRadius 𝕜 (0 : A) = 0 := by
nontriviality A
simp [spectralRadius]
#align spectrum.spectral_radius_zero spectrum.spectralRadius_zero
theorem mem_resolventSet_of_spectralRadius_lt {a : A} {k : 𝕜} (h : spectralRadius 𝕜 a < ‖k‖₊) :
k ∈ ρ a :=
Classical.not_not.mp fun hn => h.not_le <| le_iSup₂ (α := ℝ≥0∞) k hn
#align spectrum.mem_resolvent_set_of_spectral_radius_lt spectrum.mem_resolventSet_of_spectralRadius_lt
variable [CompleteSpace A]
theorem isOpen_resolventSet (a : A) : IsOpen (ρ a) :=
Units.isOpen.preimage ((continuous_algebraMap 𝕜 A).sub continuous_const)
#align spectrum.is_open_resolvent_set spectrum.isOpen_resolventSet
protected theorem isClosed (a : A) : IsClosed (σ a) :=
(isOpen_resolventSet a).isClosed_compl
#align spectrum.is_closed spectrum.isClosed
| Mathlib/Analysis/NormedSpace/Spectrum.lean | 104 | 113 | theorem mem_resolventSet_of_norm_lt_mul {a : A} {k : 𝕜} (h : ‖a‖ * ‖(1 : A)‖ < ‖k‖) : k ∈ ρ a := by |
rw [resolventSet, Set.mem_setOf_eq, Algebra.algebraMap_eq_smul_one]
nontriviality A
have hk : k ≠ 0 :=
ne_zero_of_norm_ne_zero ((mul_nonneg (norm_nonneg _) (norm_nonneg _)).trans_lt h).ne'
letI ku := Units.map ↑ₐ.toMonoidHom (Units.mk0 k hk)
rw [← inv_inv ‖(1 : A)‖,
mul_inv_lt_iff (inv_pos.2 <| norm_pos_iff.2 (one_ne_zero : (1 : A) ≠ 0))] at h
have hku : ‖-a‖ < ‖(↑ku⁻¹ : A)‖⁻¹ := by simpa [ku, norm_algebraMap] using h
simpa [ku, sub_eq_add_neg, Algebra.algebraMap_eq_smul_one] using (ku.add (-a) hku).isUnit
|
import Mathlib.Analysis.SpecialFunctions.Exp
import Mathlib.Tactic.Positivity.Core
import Mathlib.Algebra.Ring.NegOnePow
#align_import analysis.special_functions.trigonometric.basic from "leanprover-community/mathlib"@"2c1d8ca2812b64f88992a5294ea3dba144755cd1"
noncomputable section
open scoped Classical
open Topology Filter Set
namespace Real
open Real
@[simp]
theorem sin_pi : sin π = 0 := by
rw [← mul_div_cancel_left₀ π (two_ne_zero' ℝ), two_mul, add_div, sin_add, cos_pi_div_two]; simp
#align real.sin_pi Real.sin_pi
@[simp]
theorem cos_pi : cos π = -1 := by
rw [← mul_div_cancel_left₀ π (two_ne_zero' ℝ), mul_div_assoc, cos_two_mul, cos_pi_div_two]
norm_num
#align real.cos_pi Real.cos_pi
@[simp]
theorem sin_two_pi : sin (2 * π) = 0 := by simp [two_mul, sin_add]
#align real.sin_two_pi Real.sin_two_pi
@[simp]
theorem cos_two_pi : cos (2 * π) = 1 := by simp [two_mul, cos_add]
#align real.cos_two_pi Real.cos_two_pi
theorem sin_antiperiodic : Function.Antiperiodic sin π := by simp [sin_add]
#align real.sin_antiperiodic Real.sin_antiperiodic
theorem sin_periodic : Function.Periodic sin (2 * π) :=
sin_antiperiodic.periodic_two_mul
#align real.sin_periodic Real.sin_periodic
@[simp]
theorem sin_add_pi (x : ℝ) : sin (x + π) = -sin x :=
sin_antiperiodic x
#align real.sin_add_pi Real.sin_add_pi
@[simp]
theorem sin_add_two_pi (x : ℝ) : sin (x + 2 * π) = sin x :=
sin_periodic x
#align real.sin_add_two_pi Real.sin_add_two_pi
@[simp]
theorem sin_sub_pi (x : ℝ) : sin (x - π) = -sin x :=
sin_antiperiodic.sub_eq x
#align real.sin_sub_pi Real.sin_sub_pi
@[simp]
theorem sin_sub_two_pi (x : ℝ) : sin (x - 2 * π) = sin x :=
sin_periodic.sub_eq x
#align real.sin_sub_two_pi Real.sin_sub_two_pi
@[simp]
theorem sin_pi_sub (x : ℝ) : sin (π - x) = sin x :=
neg_neg (sin x) ▸ sin_neg x ▸ sin_antiperiodic.sub_eq'
#align real.sin_pi_sub Real.sin_pi_sub
@[simp]
theorem sin_two_pi_sub (x : ℝ) : sin (2 * π - x) = -sin x :=
sin_neg x ▸ sin_periodic.sub_eq'
#align real.sin_two_pi_sub Real.sin_two_pi_sub
@[simp]
theorem sin_nat_mul_pi (n : ℕ) : sin (n * π) = 0 :=
sin_antiperiodic.nat_mul_eq_of_eq_zero sin_zero n
#align real.sin_nat_mul_pi Real.sin_nat_mul_pi
@[simp]
theorem sin_int_mul_pi (n : ℤ) : sin (n * π) = 0 :=
sin_antiperiodic.int_mul_eq_of_eq_zero sin_zero n
#align real.sin_int_mul_pi Real.sin_int_mul_pi
@[simp]
theorem sin_add_nat_mul_two_pi (x : ℝ) (n : ℕ) : sin (x + n * (2 * π)) = sin x :=
sin_periodic.nat_mul n x
#align real.sin_add_nat_mul_two_pi Real.sin_add_nat_mul_two_pi
@[simp]
theorem sin_add_int_mul_two_pi (x : ℝ) (n : ℤ) : sin (x + n * (2 * π)) = sin x :=
sin_periodic.int_mul n x
#align real.sin_add_int_mul_two_pi Real.sin_add_int_mul_two_pi
@[simp]
theorem sin_sub_nat_mul_two_pi (x : ℝ) (n : ℕ) : sin (x - n * (2 * π)) = sin x :=
sin_periodic.sub_nat_mul_eq n
#align real.sin_sub_nat_mul_two_pi Real.sin_sub_nat_mul_two_pi
@[simp]
theorem sin_sub_int_mul_two_pi (x : ℝ) (n : ℤ) : sin (x - n * (2 * π)) = sin x :=
sin_periodic.sub_int_mul_eq n
#align real.sin_sub_int_mul_two_pi Real.sin_sub_int_mul_two_pi
@[simp]
theorem sin_nat_mul_two_pi_sub (x : ℝ) (n : ℕ) : sin (n * (2 * π) - x) = -sin x :=
sin_neg x ▸ sin_periodic.nat_mul_sub_eq n
#align real.sin_nat_mul_two_pi_sub Real.sin_nat_mul_two_pi_sub
@[simp]
theorem sin_int_mul_two_pi_sub (x : ℝ) (n : ℤ) : sin (n * (2 * π) - x) = -sin x :=
sin_neg x ▸ sin_periodic.int_mul_sub_eq n
#align real.sin_int_mul_two_pi_sub Real.sin_int_mul_two_pi_sub
theorem sin_add_int_mul_pi (x : ℝ) (n : ℤ) : sin (x + n * π) = (-1) ^ n * sin x :=
n.coe_negOnePow ℝ ▸ sin_antiperiodic.add_int_mul_eq n
theorem sin_add_nat_mul_pi (x : ℝ) (n : ℕ) : sin (x + n * π) = (-1) ^ n * sin x :=
sin_antiperiodic.add_nat_mul_eq n
theorem sin_sub_int_mul_pi (x : ℝ) (n : ℤ) : sin (x - n * π) = (-1) ^ n * sin x :=
n.coe_negOnePow ℝ ▸ sin_antiperiodic.sub_int_mul_eq n
theorem sin_sub_nat_mul_pi (x : ℝ) (n : ℕ) : sin (x - n * π) = (-1) ^ n * sin x :=
sin_antiperiodic.sub_nat_mul_eq n
theorem sin_int_mul_pi_sub (x : ℝ) (n : ℤ) : sin (n * π - x) = -((-1) ^ n * sin x) := by
simpa only [sin_neg, mul_neg, Int.coe_negOnePow] using sin_antiperiodic.int_mul_sub_eq n
theorem sin_nat_mul_pi_sub (x : ℝ) (n : ℕ) : sin (n * π - x) = -((-1) ^ n * sin x) := by
simpa only [sin_neg, mul_neg] using sin_antiperiodic.nat_mul_sub_eq n
theorem cos_antiperiodic : Function.Antiperiodic cos π := by simp [cos_add]
#align real.cos_antiperiodic Real.cos_antiperiodic
theorem cos_periodic : Function.Periodic cos (2 * π) :=
cos_antiperiodic.periodic_two_mul
#align real.cos_periodic Real.cos_periodic
@[simp]
theorem cos_add_pi (x : ℝ) : cos (x + π) = -cos x :=
cos_antiperiodic x
#align real.cos_add_pi Real.cos_add_pi
@[simp]
theorem cos_add_two_pi (x : ℝ) : cos (x + 2 * π) = cos x :=
cos_periodic x
#align real.cos_add_two_pi Real.cos_add_two_pi
@[simp]
theorem cos_sub_pi (x : ℝ) : cos (x - π) = -cos x :=
cos_antiperiodic.sub_eq x
#align real.cos_sub_pi Real.cos_sub_pi
@[simp]
theorem cos_sub_two_pi (x : ℝ) : cos (x - 2 * π) = cos x :=
cos_periodic.sub_eq x
#align real.cos_sub_two_pi Real.cos_sub_two_pi
@[simp]
theorem cos_pi_sub (x : ℝ) : cos (π - x) = -cos x :=
cos_neg x ▸ cos_antiperiodic.sub_eq'
#align real.cos_pi_sub Real.cos_pi_sub
@[simp]
theorem cos_two_pi_sub (x : ℝ) : cos (2 * π - x) = cos x :=
cos_neg x ▸ cos_periodic.sub_eq'
#align real.cos_two_pi_sub Real.cos_two_pi_sub
@[simp]
theorem cos_nat_mul_two_pi (n : ℕ) : cos (n * (2 * π)) = 1 :=
(cos_periodic.nat_mul_eq n).trans cos_zero
#align real.cos_nat_mul_two_pi Real.cos_nat_mul_two_pi
@[simp]
theorem cos_int_mul_two_pi (n : ℤ) : cos (n * (2 * π)) = 1 :=
(cos_periodic.int_mul_eq n).trans cos_zero
#align real.cos_int_mul_two_pi Real.cos_int_mul_two_pi
@[simp]
theorem cos_add_nat_mul_two_pi (x : ℝ) (n : ℕ) : cos (x + n * (2 * π)) = cos x :=
cos_periodic.nat_mul n x
#align real.cos_add_nat_mul_two_pi Real.cos_add_nat_mul_two_pi
@[simp]
theorem cos_add_int_mul_two_pi (x : ℝ) (n : ℤ) : cos (x + n * (2 * π)) = cos x :=
cos_periodic.int_mul n x
#align real.cos_add_int_mul_two_pi Real.cos_add_int_mul_two_pi
@[simp]
theorem cos_sub_nat_mul_two_pi (x : ℝ) (n : ℕ) : cos (x - n * (2 * π)) = cos x :=
cos_periodic.sub_nat_mul_eq n
#align real.cos_sub_nat_mul_two_pi Real.cos_sub_nat_mul_two_pi
@[simp]
theorem cos_sub_int_mul_two_pi (x : ℝ) (n : ℤ) : cos (x - n * (2 * π)) = cos x :=
cos_periodic.sub_int_mul_eq n
#align real.cos_sub_int_mul_two_pi Real.cos_sub_int_mul_two_pi
@[simp]
theorem cos_nat_mul_two_pi_sub (x : ℝ) (n : ℕ) : cos (n * (2 * π) - x) = cos x :=
cos_neg x ▸ cos_periodic.nat_mul_sub_eq n
#align real.cos_nat_mul_two_pi_sub Real.cos_nat_mul_two_pi_sub
@[simp]
theorem cos_int_mul_two_pi_sub (x : ℝ) (n : ℤ) : cos (n * (2 * π) - x) = cos x :=
cos_neg x ▸ cos_periodic.int_mul_sub_eq n
#align real.cos_int_mul_two_pi_sub Real.cos_int_mul_two_pi_sub
theorem cos_add_int_mul_pi (x : ℝ) (n : ℤ) : cos (x + n * π) = (-1) ^ n * cos x :=
n.coe_negOnePow ℝ ▸ cos_antiperiodic.add_int_mul_eq n
theorem cos_add_nat_mul_pi (x : ℝ) (n : ℕ) : cos (x + n * π) = (-1) ^ n * cos x :=
cos_antiperiodic.add_nat_mul_eq n
theorem cos_sub_int_mul_pi (x : ℝ) (n : ℤ) : cos (x - n * π) = (-1) ^ n * cos x :=
n.coe_negOnePow ℝ ▸ cos_antiperiodic.sub_int_mul_eq n
theorem cos_sub_nat_mul_pi (x : ℝ) (n : ℕ) : cos (x - n * π) = (-1) ^ n * cos x :=
cos_antiperiodic.sub_nat_mul_eq n
theorem cos_int_mul_pi_sub (x : ℝ) (n : ℤ) : cos (n * π - x) = (-1) ^ n * cos x :=
n.coe_negOnePow ℝ ▸ cos_neg x ▸ cos_antiperiodic.int_mul_sub_eq n
theorem cos_nat_mul_pi_sub (x : ℝ) (n : ℕ) : cos (n * π - x) = (-1) ^ n * cos x :=
cos_neg x ▸ cos_antiperiodic.nat_mul_sub_eq n
-- Porting note (#10618): was @[simp], but simp can prove it
theorem cos_nat_mul_two_pi_add_pi (n : ℕ) : cos (n * (2 * π) + π) = -1 := by
simpa only [cos_zero] using (cos_periodic.nat_mul n).add_antiperiod_eq cos_antiperiodic
#align real.cos_nat_mul_two_pi_add_pi Real.cos_nat_mul_two_pi_add_pi
-- Porting note (#10618): was @[simp], but simp can prove it
theorem cos_int_mul_two_pi_add_pi (n : ℤ) : cos (n * (2 * π) + π) = -1 := by
simpa only [cos_zero] using (cos_periodic.int_mul n).add_antiperiod_eq cos_antiperiodic
#align real.cos_int_mul_two_pi_add_pi Real.cos_int_mul_two_pi_add_pi
-- Porting note (#10618): was @[simp], but simp can prove it
theorem cos_nat_mul_two_pi_sub_pi (n : ℕ) : cos (n * (2 * π) - π) = -1 := by
simpa only [cos_zero] using (cos_periodic.nat_mul n).sub_antiperiod_eq cos_antiperiodic
#align real.cos_nat_mul_two_pi_sub_pi Real.cos_nat_mul_two_pi_sub_pi
-- Porting note (#10618): was @[simp], but simp can prove it
theorem cos_int_mul_two_pi_sub_pi (n : ℤ) : cos (n * (2 * π) - π) = -1 := by
simpa only [cos_zero] using (cos_periodic.int_mul n).sub_antiperiod_eq cos_antiperiodic
#align real.cos_int_mul_two_pi_sub_pi Real.cos_int_mul_two_pi_sub_pi
theorem sin_pos_of_pos_of_lt_pi {x : ℝ} (h0x : 0 < x) (hxp : x < π) : 0 < sin x :=
if hx2 : x ≤ 2 then sin_pos_of_pos_of_le_two h0x hx2
else
have : (2 : ℝ) + 2 = 4 := by norm_num
have : π - x ≤ 2 :=
sub_le_iff_le_add.2 (le_trans pi_le_four (this ▸ add_le_add_left (le_of_not_ge hx2) _))
sin_pi_sub x ▸ sin_pos_of_pos_of_le_two (sub_pos.2 hxp) this
#align real.sin_pos_of_pos_of_lt_pi Real.sin_pos_of_pos_of_lt_pi
theorem sin_pos_of_mem_Ioo {x : ℝ} (hx : x ∈ Ioo 0 π) : 0 < sin x :=
sin_pos_of_pos_of_lt_pi hx.1 hx.2
#align real.sin_pos_of_mem_Ioo Real.sin_pos_of_mem_Ioo
theorem sin_nonneg_of_mem_Icc {x : ℝ} (hx : x ∈ Icc 0 π) : 0 ≤ sin x := by
rw [← closure_Ioo pi_ne_zero.symm] at hx
exact
closure_lt_subset_le continuous_const continuous_sin
(closure_mono (fun y => sin_pos_of_mem_Ioo) hx)
#align real.sin_nonneg_of_mem_Icc Real.sin_nonneg_of_mem_Icc
theorem sin_nonneg_of_nonneg_of_le_pi {x : ℝ} (h0x : 0 ≤ x) (hxp : x ≤ π) : 0 ≤ sin x :=
sin_nonneg_of_mem_Icc ⟨h0x, hxp⟩
#align real.sin_nonneg_of_nonneg_of_le_pi Real.sin_nonneg_of_nonneg_of_le_pi
theorem sin_neg_of_neg_of_neg_pi_lt {x : ℝ} (hx0 : x < 0) (hpx : -π < x) : sin x < 0 :=
neg_pos.1 <| sin_neg x ▸ sin_pos_of_pos_of_lt_pi (neg_pos.2 hx0) (neg_lt.1 hpx)
#align real.sin_neg_of_neg_of_neg_pi_lt Real.sin_neg_of_neg_of_neg_pi_lt
theorem sin_nonpos_of_nonnpos_of_neg_pi_le {x : ℝ} (hx0 : x ≤ 0) (hpx : -π ≤ x) : sin x ≤ 0 :=
neg_nonneg.1 <| sin_neg x ▸ sin_nonneg_of_nonneg_of_le_pi (neg_nonneg.2 hx0) (neg_le.1 hpx)
#align real.sin_nonpos_of_nonnpos_of_neg_pi_le Real.sin_nonpos_of_nonnpos_of_neg_pi_le
@[simp]
theorem sin_pi_div_two : sin (π / 2) = 1 :=
have : sin (π / 2) = 1 ∨ sin (π / 2) = -1 := by
simpa [sq, mul_self_eq_one_iff] using sin_sq_add_cos_sq (π / 2)
this.resolve_right fun h =>
show ¬(0 : ℝ) < -1 by norm_num <|
h ▸ sin_pos_of_pos_of_lt_pi pi_div_two_pos (half_lt_self pi_pos)
#align real.sin_pi_div_two Real.sin_pi_div_two
theorem sin_add_pi_div_two (x : ℝ) : sin (x + π / 2) = cos x := by simp [sin_add]
#align real.sin_add_pi_div_two Real.sin_add_pi_div_two
theorem sin_sub_pi_div_two (x : ℝ) : sin (x - π / 2) = -cos x := by simp [sub_eq_add_neg, sin_add]
#align real.sin_sub_pi_div_two Real.sin_sub_pi_div_two
theorem sin_pi_div_two_sub (x : ℝ) : sin (π / 2 - x) = cos x := by simp [sub_eq_add_neg, sin_add]
#align real.sin_pi_div_two_sub Real.sin_pi_div_two_sub
theorem cos_add_pi_div_two (x : ℝ) : cos (x + π / 2) = -sin x := by simp [cos_add]
#align real.cos_add_pi_div_two Real.cos_add_pi_div_two
theorem cos_sub_pi_div_two (x : ℝ) : cos (x - π / 2) = sin x := by simp [sub_eq_add_neg, cos_add]
#align real.cos_sub_pi_div_two Real.cos_sub_pi_div_two
theorem cos_pi_div_two_sub (x : ℝ) : cos (π / 2 - x) = sin x := by
rw [← cos_neg, neg_sub, cos_sub_pi_div_two]
#align real.cos_pi_div_two_sub Real.cos_pi_div_two_sub
theorem cos_pos_of_mem_Ioo {x : ℝ} (hx : x ∈ Ioo (-(π / 2)) (π / 2)) : 0 < cos x :=
sin_add_pi_div_two x ▸ sin_pos_of_mem_Ioo ⟨by linarith [hx.1], by linarith [hx.2]⟩
#align real.cos_pos_of_mem_Ioo Real.cos_pos_of_mem_Ioo
theorem cos_nonneg_of_mem_Icc {x : ℝ} (hx : x ∈ Icc (-(π / 2)) (π / 2)) : 0 ≤ cos x :=
sin_add_pi_div_two x ▸ sin_nonneg_of_mem_Icc ⟨by linarith [hx.1], by linarith [hx.2]⟩
#align real.cos_nonneg_of_mem_Icc Real.cos_nonneg_of_mem_Icc
theorem cos_nonneg_of_neg_pi_div_two_le_of_le {x : ℝ} (hl : -(π / 2) ≤ x) (hu : x ≤ π / 2) :
0 ≤ cos x :=
cos_nonneg_of_mem_Icc ⟨hl, hu⟩
#align real.cos_nonneg_of_neg_pi_div_two_le_of_le Real.cos_nonneg_of_neg_pi_div_two_le_of_le
theorem cos_neg_of_pi_div_two_lt_of_lt {x : ℝ} (hx₁ : π / 2 < x) (hx₂ : x < π + π / 2) :
cos x < 0 :=
neg_pos.1 <| cos_pi_sub x ▸ cos_pos_of_mem_Ioo ⟨by linarith, by linarith⟩
#align real.cos_neg_of_pi_div_two_lt_of_lt Real.cos_neg_of_pi_div_two_lt_of_lt
theorem cos_nonpos_of_pi_div_two_le_of_le {x : ℝ} (hx₁ : π / 2 ≤ x) (hx₂ : x ≤ π + π / 2) :
cos x ≤ 0 :=
neg_nonneg.1 <| cos_pi_sub x ▸ cos_nonneg_of_mem_Icc ⟨by linarith, by linarith⟩
#align real.cos_nonpos_of_pi_div_two_le_of_le Real.cos_nonpos_of_pi_div_two_le_of_le
theorem sin_eq_sqrt_one_sub_cos_sq {x : ℝ} (hl : 0 ≤ x) (hu : x ≤ π) :
sin x = √(1 - cos x ^ 2) := by
rw [← abs_sin_eq_sqrt_one_sub_cos_sq, abs_of_nonneg (sin_nonneg_of_nonneg_of_le_pi hl hu)]
#align real.sin_eq_sqrt_one_sub_cos_sq Real.sin_eq_sqrt_one_sub_cos_sq
theorem cos_eq_sqrt_one_sub_sin_sq {x : ℝ} (hl : -(π / 2) ≤ x) (hu : x ≤ π / 2) :
cos x = √(1 - sin x ^ 2) := by
rw [← abs_cos_eq_sqrt_one_sub_sin_sq, abs_of_nonneg (cos_nonneg_of_mem_Icc ⟨hl, hu⟩)]
#align real.cos_eq_sqrt_one_sub_sin_sq Real.cos_eq_sqrt_one_sub_sin_sq
lemma cos_half {x : ℝ} (hl : -π ≤ x) (hr : x ≤ π) : cos (x / 2) = sqrt ((1 + cos x) / 2) := by
have : 0 ≤ cos (x / 2) := cos_nonneg_of_mem_Icc <| by constructor <;> linarith
rw [← sqrt_sq this, cos_sq, add_div, two_mul, add_halves]
lemma abs_sin_half (x : ℝ) : |sin (x / 2)| = sqrt ((1 - cos x) / 2) := by
rw [← sqrt_sq_eq_abs, sin_sq_eq_half_sub, two_mul, add_halves, sub_div]
lemma sin_half_eq_sqrt {x : ℝ} (hl : 0 ≤ x) (hr : x ≤ 2 * π) :
sin (x / 2) = sqrt ((1 - cos x) / 2) := by
rw [← abs_sin_half, abs_of_nonneg]
apply sin_nonneg_of_nonneg_of_le_pi <;> linarith
lemma sin_half_eq_neg_sqrt {x : ℝ} (hl : -(2 * π) ≤ x) (hr : x ≤ 0) :
sin (x / 2) = -sqrt ((1 - cos x) / 2) := by
rw [← abs_sin_half, abs_of_nonpos, neg_neg]
apply sin_nonpos_of_nonnpos_of_neg_pi_le <;> linarith
theorem sin_eq_zero_iff_of_lt_of_lt {x : ℝ} (hx₁ : -π < x) (hx₂ : x < π) : sin x = 0 ↔ x = 0 :=
⟨fun h => by
contrapose! h
cases h.lt_or_lt with
| inl h0 => exact (sin_neg_of_neg_of_neg_pi_lt h0 hx₁).ne
| inr h0 => exact (sin_pos_of_pos_of_lt_pi h0 hx₂).ne',
fun h => by simp [h]⟩
#align real.sin_eq_zero_iff_of_lt_of_lt Real.sin_eq_zero_iff_of_lt_of_lt
theorem sin_eq_zero_iff {x : ℝ} : sin x = 0 ↔ ∃ n : ℤ, (n : ℝ) * π = x :=
⟨fun h =>
⟨⌊x / π⌋,
le_antisymm (sub_nonneg.1 (Int.sub_floor_div_mul_nonneg _ pi_pos))
(sub_nonpos.1 <|
le_of_not_gt fun h₃ =>
(sin_pos_of_pos_of_lt_pi h₃ (Int.sub_floor_div_mul_lt _ pi_pos)).ne
(by simp [sub_eq_add_neg, sin_add, h, sin_int_mul_pi]))⟩,
fun ⟨n, hn⟩ => hn ▸ sin_int_mul_pi _⟩
#align real.sin_eq_zero_iff Real.sin_eq_zero_iff
theorem sin_ne_zero_iff {x : ℝ} : sin x ≠ 0 ↔ ∀ n : ℤ, (n : ℝ) * π ≠ x := by
rw [← not_exists, not_iff_not, sin_eq_zero_iff]
#align real.sin_ne_zero_iff Real.sin_ne_zero_iff
theorem sin_eq_zero_iff_cos_eq {x : ℝ} : sin x = 0 ↔ cos x = 1 ∨ cos x = -1 := by
rw [← mul_self_eq_one_iff, ← sin_sq_add_cos_sq x, sq, sq, ← sub_eq_iff_eq_add, sub_self]
exact ⟨fun h => by rw [h, mul_zero], eq_zero_of_mul_self_eq_zero ∘ Eq.symm⟩
#align real.sin_eq_zero_iff_cos_eq Real.sin_eq_zero_iff_cos_eq
theorem cos_eq_one_iff (x : ℝ) : cos x = 1 ↔ ∃ n : ℤ, (n : ℝ) * (2 * π) = x :=
⟨fun h =>
let ⟨n, hn⟩ := sin_eq_zero_iff.1 (sin_eq_zero_iff_cos_eq.2 (Or.inl h))
⟨n / 2,
(Int.emod_two_eq_zero_or_one n).elim
(fun hn0 => by
rwa [← mul_assoc, ← @Int.cast_two ℝ, ← Int.cast_mul,
Int.ediv_mul_cancel ((Int.dvd_iff_emod_eq_zero _ _).2 hn0)])
fun hn1 => by
rw [← Int.emod_add_ediv n 2, hn1, Int.cast_add, Int.cast_one, add_mul, one_mul, add_comm,
mul_comm (2 : ℤ), Int.cast_mul, mul_assoc, Int.cast_two] at hn
rw [← hn, cos_int_mul_two_pi_add_pi] at h
exact absurd h (by norm_num)⟩,
fun ⟨n, hn⟩ => hn ▸ cos_int_mul_two_pi _⟩
#align real.cos_eq_one_iff Real.cos_eq_one_iff
theorem cos_eq_one_iff_of_lt_of_lt {x : ℝ} (hx₁ : -(2 * π) < x) (hx₂ : x < 2 * π) :
cos x = 1 ↔ x = 0 :=
⟨fun h => by
rcases (cos_eq_one_iff _).1 h with ⟨n, rfl⟩
rw [mul_lt_iff_lt_one_left two_pi_pos] at hx₂
rw [neg_lt, neg_mul_eq_neg_mul, mul_lt_iff_lt_one_left two_pi_pos] at hx₁
norm_cast at hx₁ hx₂
obtain rfl : n = 0 := le_antisymm (by omega) (by omega)
simp, fun h => by simp [h]⟩
#align real.cos_eq_one_iff_of_lt_of_lt Real.cos_eq_one_iff_of_lt_of_lt
theorem sin_lt_sin_of_lt_of_le_pi_div_two {x y : ℝ} (hx₁ : -(π / 2) ≤ x) (hy₂ : y ≤ π / 2)
(hxy : x < y) : sin x < sin y := by
rw [← sub_pos, sin_sub_sin]
have : 0 < sin ((y - x) / 2) := by apply sin_pos_of_pos_of_lt_pi <;> linarith
have : 0 < cos ((y + x) / 2) := by refine cos_pos_of_mem_Ioo ⟨?_, ?_⟩ <;> linarith
positivity
#align real.sin_lt_sin_of_lt_of_le_pi_div_two Real.sin_lt_sin_of_lt_of_le_pi_div_two
theorem strictMonoOn_sin : StrictMonoOn sin (Icc (-(π / 2)) (π / 2)) := fun _ hx _ hy hxy =>
sin_lt_sin_of_lt_of_le_pi_div_two hx.1 hy.2 hxy
#align real.strict_mono_on_sin Real.strictMonoOn_sin
theorem cos_lt_cos_of_nonneg_of_le_pi {x y : ℝ} (hx₁ : 0 ≤ x) (hy₂ : y ≤ π) (hxy : x < y) :
cos y < cos x := by
rw [← sin_pi_div_two_sub, ← sin_pi_div_two_sub]
apply sin_lt_sin_of_lt_of_le_pi_div_two <;> linarith
#align real.cos_lt_cos_of_nonneg_of_le_pi Real.cos_lt_cos_of_nonneg_of_le_pi
theorem cos_lt_cos_of_nonneg_of_le_pi_div_two {x y : ℝ} (hx₁ : 0 ≤ x) (hy₂ : y ≤ π / 2)
(hxy : x < y) : cos y < cos x :=
cos_lt_cos_of_nonneg_of_le_pi hx₁ (hy₂.trans (by linarith)) hxy
#align real.cos_lt_cos_of_nonneg_of_le_pi_div_two Real.cos_lt_cos_of_nonneg_of_le_pi_div_two
theorem strictAntiOn_cos : StrictAntiOn cos (Icc 0 π) := fun _ hx _ hy hxy =>
cos_lt_cos_of_nonneg_of_le_pi hx.1 hy.2 hxy
#align real.strict_anti_on_cos Real.strictAntiOn_cos
theorem cos_le_cos_of_nonneg_of_le_pi {x y : ℝ} (hx₁ : 0 ≤ x) (hy₂ : y ≤ π) (hxy : x ≤ y) :
cos y ≤ cos x :=
(strictAntiOn_cos.le_iff_le ⟨hx₁.trans hxy, hy₂⟩ ⟨hx₁, hxy.trans hy₂⟩).2 hxy
#align real.cos_le_cos_of_nonneg_of_le_pi Real.cos_le_cos_of_nonneg_of_le_pi
theorem sin_le_sin_of_le_of_le_pi_div_two {x y : ℝ} (hx₁ : -(π / 2) ≤ x) (hy₂ : y ≤ π / 2)
(hxy : x ≤ y) : sin x ≤ sin y :=
(strictMonoOn_sin.le_iff_le ⟨hx₁, hxy.trans hy₂⟩ ⟨hx₁.trans hxy, hy₂⟩).2 hxy
#align real.sin_le_sin_of_le_of_le_pi_div_two Real.sin_le_sin_of_le_of_le_pi_div_two
theorem injOn_sin : InjOn sin (Icc (-(π / 2)) (π / 2)) :=
strictMonoOn_sin.injOn
#align real.inj_on_sin Real.injOn_sin
theorem injOn_cos : InjOn cos (Icc 0 π) :=
strictAntiOn_cos.injOn
#align real.inj_on_cos Real.injOn_cos
theorem surjOn_sin : SurjOn sin (Icc (-(π / 2)) (π / 2)) (Icc (-1) 1) := by
simpa only [sin_neg, sin_pi_div_two] using
intermediate_value_Icc (neg_le_self pi_div_two_pos.le) continuous_sin.continuousOn
#align real.surj_on_sin Real.surjOn_sin
theorem surjOn_cos : SurjOn cos (Icc 0 π) (Icc (-1) 1) := by
simpa only [cos_zero, cos_pi] using intermediate_value_Icc' pi_pos.le continuous_cos.continuousOn
#align real.surj_on_cos Real.surjOn_cos
theorem sin_mem_Icc (x : ℝ) : sin x ∈ Icc (-1 : ℝ) 1 :=
⟨neg_one_le_sin x, sin_le_one x⟩
#align real.sin_mem_Icc Real.sin_mem_Icc
theorem cos_mem_Icc (x : ℝ) : cos x ∈ Icc (-1 : ℝ) 1 :=
⟨neg_one_le_cos x, cos_le_one x⟩
#align real.cos_mem_Icc Real.cos_mem_Icc
theorem mapsTo_sin (s : Set ℝ) : MapsTo sin s (Icc (-1 : ℝ) 1) := fun x _ => sin_mem_Icc x
#align real.maps_to_sin Real.mapsTo_sin
theorem mapsTo_cos (s : Set ℝ) : MapsTo cos s (Icc (-1 : ℝ) 1) := fun x _ => cos_mem_Icc x
#align real.maps_to_cos Real.mapsTo_cos
theorem bijOn_sin : BijOn sin (Icc (-(π / 2)) (π / 2)) (Icc (-1) 1) :=
⟨mapsTo_sin _, injOn_sin, surjOn_sin⟩
#align real.bij_on_sin Real.bijOn_sin
theorem bijOn_cos : BijOn cos (Icc 0 π) (Icc (-1) 1) :=
⟨mapsTo_cos _, injOn_cos, surjOn_cos⟩
#align real.bij_on_cos Real.bijOn_cos
@[simp]
theorem range_cos : range cos = (Icc (-1) 1 : Set ℝ) :=
Subset.antisymm (range_subset_iff.2 cos_mem_Icc) surjOn_cos.subset_range
#align real.range_cos Real.range_cos
@[simp]
theorem range_sin : range sin = (Icc (-1) 1 : Set ℝ) :=
Subset.antisymm (range_subset_iff.2 sin_mem_Icc) surjOn_sin.subset_range
#align real.range_sin Real.range_sin
theorem range_cos_infinite : (range Real.cos).Infinite := by
rw [Real.range_cos]
exact Icc_infinite (by norm_num)
#align real.range_cos_infinite Real.range_cos_infinite
theorem range_sin_infinite : (range Real.sin).Infinite := by
rw [Real.range_sin]
exact Icc_infinite (by norm_num)
#align real.range_sin_infinite Real.range_sin_infinite
namespace Complex
open Real
theorem sin_eq_zero_iff_cos_eq {z : ℂ} : sin z = 0 ↔ cos z = 1 ∨ cos z = -1 := by
rw [← mul_self_eq_one_iff, ← sin_sq_add_cos_sq, sq, sq, ← sub_eq_iff_eq_add, sub_self]
exact ⟨fun h => by rw [h, mul_zero], eq_zero_of_mul_self_eq_zero ∘ Eq.symm⟩
#align complex.sin_eq_zero_iff_cos_eq Complex.sin_eq_zero_iff_cos_eq
@[simp]
theorem cos_pi_div_two : cos (π / 2) = 0 :=
calc
cos (π / 2) = Real.cos (π / 2) := by rw [ofReal_cos]; simp
_ = 0 := by simp
#align complex.cos_pi_div_two Complex.cos_pi_div_two
@[simp]
theorem sin_pi_div_two : sin (π / 2) = 1 :=
calc
sin (π / 2) = Real.sin (π / 2) := by rw [ofReal_sin]; simp
_ = 1 := by simp
#align complex.sin_pi_div_two Complex.sin_pi_div_two
@[simp]
theorem sin_pi : sin π = 0 := by rw [← ofReal_sin, Real.sin_pi]; simp
#align complex.sin_pi Complex.sin_pi
@[simp]
theorem cos_pi : cos π = -1 := by rw [← ofReal_cos, Real.cos_pi]; simp
#align complex.cos_pi Complex.cos_pi
@[simp]
theorem sin_two_pi : sin (2 * π) = 0 := by simp [two_mul, sin_add]
#align complex.sin_two_pi Complex.sin_two_pi
@[simp]
theorem cos_two_pi : cos (2 * π) = 1 := by simp [two_mul, cos_add]
#align complex.cos_two_pi Complex.cos_two_pi
theorem sin_antiperiodic : Function.Antiperiodic sin π := by simp [sin_add]
#align complex.sin_antiperiodic Complex.sin_antiperiodic
theorem sin_periodic : Function.Periodic sin (2 * π) :=
sin_antiperiodic.periodic_two_mul
#align complex.sin_periodic Complex.sin_periodic
theorem sin_add_pi (x : ℂ) : sin (x + π) = -sin x :=
sin_antiperiodic x
#align complex.sin_add_pi Complex.sin_add_pi
theorem sin_add_two_pi (x : ℂ) : sin (x + 2 * π) = sin x :=
sin_periodic x
#align complex.sin_add_two_pi Complex.sin_add_two_pi
theorem sin_sub_pi (x : ℂ) : sin (x - π) = -sin x :=
sin_antiperiodic.sub_eq x
#align complex.sin_sub_pi Complex.sin_sub_pi
theorem sin_sub_two_pi (x : ℂ) : sin (x - 2 * π) = sin x :=
sin_periodic.sub_eq x
#align complex.sin_sub_two_pi Complex.sin_sub_two_pi
theorem sin_pi_sub (x : ℂ) : sin (π - x) = sin x :=
neg_neg (sin x) ▸ sin_neg x ▸ sin_antiperiodic.sub_eq'
#align complex.sin_pi_sub Complex.sin_pi_sub
theorem sin_two_pi_sub (x : ℂ) : sin (2 * π - x) = -sin x :=
sin_neg x ▸ sin_periodic.sub_eq'
#align complex.sin_two_pi_sub Complex.sin_two_pi_sub
theorem sin_nat_mul_pi (n : ℕ) : sin (n * π) = 0 :=
sin_antiperiodic.nat_mul_eq_of_eq_zero sin_zero n
#align complex.sin_nat_mul_pi Complex.sin_nat_mul_pi
theorem sin_int_mul_pi (n : ℤ) : sin (n * π) = 0 :=
sin_antiperiodic.int_mul_eq_of_eq_zero sin_zero n
#align complex.sin_int_mul_pi Complex.sin_int_mul_pi
theorem sin_add_nat_mul_two_pi (x : ℂ) (n : ℕ) : sin (x + n * (2 * π)) = sin x :=
sin_periodic.nat_mul n x
#align complex.sin_add_nat_mul_two_pi Complex.sin_add_nat_mul_two_pi
theorem sin_add_int_mul_two_pi (x : ℂ) (n : ℤ) : sin (x + n * (2 * π)) = sin x :=
sin_periodic.int_mul n x
#align complex.sin_add_int_mul_two_pi Complex.sin_add_int_mul_two_pi
theorem sin_sub_nat_mul_two_pi (x : ℂ) (n : ℕ) : sin (x - n * (2 * π)) = sin x :=
sin_periodic.sub_nat_mul_eq n
#align complex.sin_sub_nat_mul_two_pi Complex.sin_sub_nat_mul_two_pi
theorem sin_sub_int_mul_two_pi (x : ℂ) (n : ℤ) : sin (x - n * (2 * π)) = sin x :=
sin_periodic.sub_int_mul_eq n
#align complex.sin_sub_int_mul_two_pi Complex.sin_sub_int_mul_two_pi
theorem sin_nat_mul_two_pi_sub (x : ℂ) (n : ℕ) : sin (n * (2 * π) - x) = -sin x :=
sin_neg x ▸ sin_periodic.nat_mul_sub_eq n
#align complex.sin_nat_mul_two_pi_sub Complex.sin_nat_mul_two_pi_sub
theorem sin_int_mul_two_pi_sub (x : ℂ) (n : ℤ) : sin (n * (2 * π) - x) = -sin x :=
sin_neg x ▸ sin_periodic.int_mul_sub_eq n
#align complex.sin_int_mul_two_pi_sub Complex.sin_int_mul_two_pi_sub
| Mathlib/Analysis/SpecialFunctions/Trigonometric/Basic.lean | 1,217 | 1,217 | theorem cos_antiperiodic : Function.Antiperiodic cos π := by | simp [cos_add]
|
import Mathlib.Logic.Equiv.Defs
import Mathlib.Tactic.MkIffOfInductiveProp
import Mathlib.Tactic.PPWithUniv
#align_import logic.small.basic from "leanprover-community/mathlib"@"d012cd09a9b256d870751284dd6a29882b0be105"
universe u w v v'
@[mk_iff, pp_with_univ]
class Small (α : Type v) : Prop where
equiv_small : ∃ S : Type w, Nonempty (α ≃ S)
#align small Small
theorem Small.mk' {α : Type v} {S : Type w} (e : α ≃ S) : Small.{w} α :=
⟨⟨S, ⟨e⟩⟩⟩
#align small.mk' Small.mk'
@[pp_with_univ]
def Shrink (α : Type v) [Small.{w} α] : Type w :=
Classical.choose (@Small.equiv_small α _)
#align shrink Shrink
noncomputable def equivShrink (α : Type v) [Small.{w} α] : α ≃ Shrink α :=
Nonempty.some (Classical.choose_spec (@Small.equiv_small α _))
#align equiv_shrink equivShrink
@[ext]
| Mathlib/Logic/Small/Defs.lean | 56 | 58 | theorem Shrink.ext {α : Type v} [Small.{w} α] {x y : Shrink α}
(w : (equivShrink _).symm x = (equivShrink _).symm y) : x = y := by |
simpa using w
|
import Mathlib.Algebra.Algebra.Basic
import Mathlib.Algebra.Periodic
import Mathlib.Topology.Algebra.Order.Field
import Mathlib.Topology.Algebra.UniformMulAction
import Mathlib.Topology.Algebra.Star
import Mathlib.Topology.Instances.Int
import Mathlib.Topology.Order.Bornology
#align_import topology.instances.real from "leanprover-community/mathlib"@"9a59dcb7a2d06bf55da57b9030169219980660cd"
noncomputable section
open scoped Classical
open Filter Int Metric Set TopologicalSpace Bornology
open scoped Topology Uniformity Interval
universe u v w
variable {α : Type u} {β : Type v} {γ : Type w}
instance : NoncompactSpace ℝ := Int.closedEmbedding_coe_real.noncompactSpace
theorem Real.uniformContinuous_add : UniformContinuous fun p : ℝ × ℝ => p.1 + p.2 :=
Metric.uniformContinuous_iff.2 fun _ε ε0 =>
let ⟨δ, δ0, Hδ⟩ := rat_add_continuous_lemma abs ε0
⟨δ, δ0, fun h =>
let ⟨h₁, h₂⟩ := max_lt_iff.1 h
Hδ h₁ h₂⟩
#align real.uniform_continuous_add Real.uniformContinuous_add
theorem Real.uniformContinuous_neg : UniformContinuous (@Neg.neg ℝ _) :=
Metric.uniformContinuous_iff.2 fun ε ε0 =>
⟨_, ε0, fun h => by rw [dist_comm] at h; simpa only [Real.dist_eq, neg_sub_neg] using h⟩
#align real.uniform_continuous_neg Real.uniformContinuous_neg
instance : ContinuousStar ℝ := ⟨continuous_id⟩
instance : UniformAddGroup ℝ :=
UniformAddGroup.mk' Real.uniformContinuous_add Real.uniformContinuous_neg
-- short-circuit type class inference
instance : TopologicalAddGroup ℝ := by infer_instance
instance : TopologicalRing ℝ := inferInstance
instance : TopologicalDivisionRing ℝ := inferInstance
instance : ProperSpace ℝ where
isCompact_closedBall x r := by
rw [Real.closedBall_eq_Icc]
apply isCompact_Icc
instance : SecondCountableTopology ℝ := secondCountable_of_proper
theorem Real.isTopologicalBasis_Ioo_rat :
@IsTopologicalBasis ℝ _ (⋃ (a : ℚ) (b : ℚ) (_ : a < b), {Ioo (a : ℝ) b}) :=
isTopologicalBasis_of_isOpen_of_nhds (by simp (config := { contextual := true }) [isOpen_Ioo])
fun a v hav hv =>
let ⟨l, u, ⟨hl, hu⟩, h⟩ := mem_nhds_iff_exists_Ioo_subset.mp (IsOpen.mem_nhds hv hav)
let ⟨q, hlq, hqa⟩ := exists_rat_btwn hl
let ⟨p, hap, hpu⟩ := exists_rat_btwn hu
⟨Ioo q p, by
simp only [mem_iUnion]
exact ⟨q, p, Rat.cast_lt.1 <| hqa.trans hap, rfl⟩, ⟨hqa, hap⟩, fun a' ⟨hqa', ha'p⟩ =>
h ⟨hlq.trans hqa', ha'p.trans hpu⟩⟩
#align real.is_topological_basis_Ioo_rat Real.isTopologicalBasis_Ioo_rat
@[simp]
theorem Real.cobounded_eq : cobounded ℝ = atBot ⊔ atTop := by
simp only [← comap_dist_right_atTop (0 : ℝ), Real.dist_eq, sub_zero, comap_abs_atTop]
@[deprecated] alias Real.cocompact_eq := cocompact_eq_atBot_atTop
#align real.cocompact_eq Real.cocompact_eq
@[deprecated (since := "2024-02-07")] alias Real.atBot_le_cocompact := atBot_le_cocompact
@[deprecated (since := "2024-02-07")] alias Real.atTop_le_cocompact := atTop_le_cocompact
| Mathlib/Topology/Instances/Real.lean | 92 | 94 | theorem Real.mem_closure_iff {s : Set ℝ} {x : ℝ} :
x ∈ closure s ↔ ∀ ε > 0, ∃ y ∈ s, |y - x| < ε := by |
simp [mem_closure_iff_nhds_basis nhds_basis_ball, Real.dist_eq]
|
import Mathlib.Analysis.InnerProductSpace.GramSchmidtOrtho
import Mathlib.LinearAlgebra.Orientation
#align_import analysis.inner_product_space.orientation from "leanprover-community/mathlib"@"bd65478311e4dfd41f48bf38c7e3b02fb75d0163"
noncomputable section
variable {E : Type*} [NormedAddCommGroup E] [InnerProductSpace ℝ E]
open FiniteDimensional
open scoped RealInnerProductSpace
namespace OrthonormalBasis
variable {ι : Type*} [Fintype ι] [DecidableEq ι] [ne : Nonempty ι] (e f : OrthonormalBasis ι ℝ E)
(x : Orientation ℝ E ι)
theorem det_to_matrix_orthonormalBasis_of_same_orientation
(h : e.toBasis.orientation = f.toBasis.orientation) : e.toBasis.det f = 1 := by
apply (e.det_to_matrix_orthonormalBasis_real f).resolve_right
have : 0 < e.toBasis.det f := by
rw [e.toBasis.orientation_eq_iff_det_pos] at h
simpa using h
linarith
#align orthonormal_basis.det_to_matrix_orthonormal_basis_of_same_orientation OrthonormalBasis.det_to_matrix_orthonormalBasis_of_same_orientation
theorem det_to_matrix_orthonormalBasis_of_opposite_orientation
(h : e.toBasis.orientation ≠ f.toBasis.orientation) : e.toBasis.det f = -1 := by
contrapose! h
simp [e.toBasis.orientation_eq_iff_det_pos,
(e.det_to_matrix_orthonormalBasis_real f).resolve_right h]
#align orthonormal_basis.det_to_matrix_orthonormal_basis_of_opposite_orientation OrthonormalBasis.det_to_matrix_orthonormalBasis_of_opposite_orientation
variable {e f}
| Mathlib/Analysis/InnerProductSpace/Orientation.lean | 76 | 84 | theorem same_orientation_iff_det_eq_det :
e.toBasis.det = f.toBasis.det ↔ e.toBasis.orientation = f.toBasis.orientation := by |
constructor
· intro h
dsimp [Basis.orientation]
congr
· intro h
rw [e.toBasis.det.eq_smul_basis_det f.toBasis]
simp [e.det_to_matrix_orthonormalBasis_of_same_orientation f h]
|
import Mathlib.CategoryTheory.Sites.Sieves
#align_import category_theory.sites.sheaf_of_types from "leanprover-community/mathlib"@"70fd9563a21e7b963887c9360bd29b2393e6225a"
universe w v₁ v₂ u₁ u₂
namespace CategoryTheory
open Opposite CategoryTheory Category Limits Sieve
namespace Presieve
variable {C : Type u₁} [Category.{v₁} C]
variable {P Q U : Cᵒᵖ ⥤ Type w}
variable {X Y : C} {S : Sieve X} {R : Presieve X}
def FamilyOfElements (P : Cᵒᵖ ⥤ Type w) (R : Presieve X) :=
∀ ⦃Y : C⦄ (f : Y ⟶ X), R f → P.obj (op Y)
#align category_theory.presieve.family_of_elements CategoryTheory.Presieve.FamilyOfElements
instance : Inhabited (FamilyOfElements P (⊥ : Presieve X)) :=
⟨fun _ _ => False.elim⟩
def FamilyOfElements.restrict {R₁ R₂ : Presieve X} (h : R₁ ≤ R₂) :
FamilyOfElements P R₂ → FamilyOfElements P R₁ := fun x _ f hf => x f (h _ hf)
#align category_theory.presieve.family_of_elements.restrict CategoryTheory.Presieve.FamilyOfElements.restrict
def FamilyOfElements.map (p : FamilyOfElements P R) (φ : P ⟶ Q) :
FamilyOfElements Q R :=
fun _ f hf => φ.app _ (p f hf)
@[simp]
lemma FamilyOfElements.map_apply
(p : FamilyOfElements P R) (φ : P ⟶ Q) {Y : C} (f : Y ⟶ X) (hf : R f) :
p.map φ f hf = φ.app _ (p f hf) := rfl
lemma FamilyOfElements.restrict_map
(p : FamilyOfElements P R) (φ : P ⟶ Q) {R' : Presieve X} (h : R' ≤ R) :
(p.restrict h).map φ = (p.map φ).restrict h := rfl
def FamilyOfElements.Compatible (x : FamilyOfElements P R) : Prop :=
∀ ⦃Y₁ Y₂ Z⦄ (g₁ : Z ⟶ Y₁) (g₂ : Z ⟶ Y₂) ⦃f₁ : Y₁ ⟶ X⦄ ⦃f₂ : Y₂ ⟶ X⦄ (h₁ : R f₁) (h₂ : R f₂),
g₁ ≫ f₁ = g₂ ≫ f₂ → P.map g₁.op (x f₁ h₁) = P.map g₂.op (x f₂ h₂)
#align category_theory.presieve.family_of_elements.compatible CategoryTheory.Presieve.FamilyOfElements.Compatible
def FamilyOfElements.PullbackCompatible (x : FamilyOfElements P R) [R.hasPullbacks] : Prop :=
∀ ⦃Y₁ Y₂⦄ ⦃f₁ : Y₁ ⟶ X⦄ ⦃f₂ : Y₂ ⟶ X⦄ (h₁ : R f₁) (h₂ : R f₂),
haveI := hasPullbacks.has_pullbacks h₁ h₂
P.map (pullback.fst : Limits.pullback f₁ f₂ ⟶ _).op (x f₁ h₁) = P.map pullback.snd.op (x f₂ h₂)
#align category_theory.presieve.family_of_elements.pullback_compatible CategoryTheory.Presieve.FamilyOfElements.PullbackCompatible
theorem pullbackCompatible_iff (x : FamilyOfElements P R) [R.hasPullbacks] :
x.Compatible ↔ x.PullbackCompatible := by
constructor
· intro t Y₁ Y₂ f₁ f₂ hf₁ hf₂
apply t
haveI := hasPullbacks.has_pullbacks hf₁ hf₂
apply pullback.condition
· intro t Y₁ Y₂ Z g₁ g₂ f₁ f₂ hf₁ hf₂ comm
haveI := hasPullbacks.has_pullbacks hf₁ hf₂
rw [← pullback.lift_fst _ _ comm, op_comp, FunctorToTypes.map_comp_apply, t hf₁ hf₂,
← FunctorToTypes.map_comp_apply, ← op_comp, pullback.lift_snd]
#align category_theory.presieve.pullback_compatible_iff CategoryTheory.Presieve.pullbackCompatible_iff
theorem FamilyOfElements.Compatible.restrict {R₁ R₂ : Presieve X} (h : R₁ ≤ R₂)
{x : FamilyOfElements P R₂} : x.Compatible → (x.restrict h).Compatible :=
fun q _ _ _ g₁ g₂ _ _ h₁ h₂ comm => q g₁ g₂ (h _ h₁) (h _ h₂) comm
#align category_theory.presieve.family_of_elements.compatible.restrict CategoryTheory.Presieve.FamilyOfElements.Compatible.restrict
noncomputable def FamilyOfElements.sieveExtend (x : FamilyOfElements P R) :
FamilyOfElements P (generate R : Presieve X) := fun _ _ hf =>
P.map hf.choose_spec.choose.op (x _ hf.choose_spec.choose_spec.choose_spec.1)
#align category_theory.presieve.family_of_elements.sieve_extend CategoryTheory.Presieve.FamilyOfElements.sieveExtend
theorem FamilyOfElements.Compatible.sieveExtend {x : FamilyOfElements P R} (hx : x.Compatible) :
x.sieveExtend.Compatible := by
intro _ _ _ _ _ _ _ h₁ h₂ comm
iterate 2 erw [← FunctorToTypes.map_comp_apply]; rw [← op_comp]
apply hx
simp [comm, h₁.choose_spec.choose_spec.choose_spec.2, h₂.choose_spec.choose_spec.choose_spec.2]
#align category_theory.presieve.family_of_elements.compatible.sieve_extend CategoryTheory.Presieve.FamilyOfElements.Compatible.sieveExtend
theorem extend_agrees {x : FamilyOfElements P R} (t : x.Compatible) {f : Y ⟶ X} (hf : R f) :
x.sieveExtend f (le_generate R Y hf) = x f hf := by
have h := (le_generate R Y hf).choose_spec
unfold FamilyOfElements.sieveExtend
rw [t h.choose (𝟙 _) _ hf _]
· simp
· rw [id_comp]
exact h.choose_spec.choose_spec.2
#align category_theory.presieve.extend_agrees CategoryTheory.Presieve.extend_agrees
@[simp]
theorem restrict_extend {x : FamilyOfElements P R} (t : x.Compatible) :
x.sieveExtend.restrict (le_generate R) = x := by
funext Y f hf
exact extend_agrees t hf
#align category_theory.presieve.restrict_extend CategoryTheory.Presieve.restrict_extend
def FamilyOfElements.SieveCompatible (x : FamilyOfElements P (S : Presieve X)) : Prop :=
∀ ⦃Y Z⦄ (f : Y ⟶ X) (g : Z ⟶ Y) (hf), x (g ≫ f) (S.downward_closed hf g) = P.map g.op (x f hf)
#align category_theory.presieve.family_of_elements.sieve_compatible CategoryTheory.Presieve.FamilyOfElements.SieveCompatible
theorem compatible_iff_sieveCompatible (x : FamilyOfElements P (S : Presieve X)) :
x.Compatible ↔ x.SieveCompatible := by
constructor
· intro h Y Z f g hf
simpa using h (𝟙 _) g (S.downward_closed hf g) hf (id_comp _)
· intro h Y₁ Y₂ Z g₁ g₂ f₁ f₂ h₁ h₂ k
simp_rw [← h f₁ g₁ h₁, ← h f₂ g₂ h₂]
congr
#align category_theory.presieve.compatible_iff_sieve_compatible CategoryTheory.Presieve.compatible_iff_sieveCompatible
theorem FamilyOfElements.Compatible.to_sieveCompatible {x : FamilyOfElements P (S : Presieve X)}
(t : x.Compatible) : x.SieveCompatible :=
(compatible_iff_sieveCompatible x).1 t
#align category_theory.presieve.family_of_elements.compatible.to_sieve_compatible CategoryTheory.Presieve.FamilyOfElements.Compatible.to_sieveCompatible
@[simp]
theorem extend_restrict {x : FamilyOfElements P (generate R)} (t : x.Compatible) :
(x.restrict (le_generate R)).sieveExtend = x := by
rw [compatible_iff_sieveCompatible] at t
funext _ _ h
apply (t _ _ _).symm.trans
congr
exact h.choose_spec.choose_spec.choose_spec.2
#align category_theory.presieve.extend_restrict CategoryTheory.Presieve.extend_restrict
theorem restrict_inj {x₁ x₂ : FamilyOfElements P (generate R)} (t₁ : x₁.Compatible)
(t₂ : x₂.Compatible) : x₁.restrict (le_generate R) = x₂.restrict (le_generate R) → x₁ = x₂ :=
fun h => by
rw [← extend_restrict t₁, ← extend_restrict t₂]
-- Porting note: congr fails to make progress
apply congr_arg
exact h
#align category_theory.presieve.restrict_inj CategoryTheory.Presieve.restrict_inj
@[simps]
noncomputable def compatibleEquivGenerateSieveCompatible :
{ x : FamilyOfElements P R // x.Compatible } ≃
{ x : FamilyOfElements P (generate R : Presieve X) // x.Compatible } where
toFun x := ⟨x.1.sieveExtend, x.2.sieveExtend⟩
invFun x := ⟨x.1.restrict (le_generate R), x.2.restrict _⟩
left_inv x := Subtype.ext (restrict_extend x.2)
right_inv x := Subtype.ext (extend_restrict x.2)
#align category_theory.presieve.compatible_equiv_generate_sieve_compatible CategoryTheory.Presieve.compatibleEquivGenerateSieveCompatible
theorem FamilyOfElements.comp_of_compatible (S : Sieve X) {x : FamilyOfElements P S}
(t : x.Compatible) {f : Y ⟶ X} (hf : S f) {Z} (g : Z ⟶ Y) :
x (g ≫ f) (S.downward_closed hf g) = P.map g.op (x f hf) := by
simpa using t (𝟙 _) g (S.downward_closed hf g) hf (id_comp _)
#align category_theory.presieve.family_of_elements.comp_of_compatible CategoryTheory.Presieve.FamilyOfElements.comp_of_compatible
noncomputable def FamilyOfElements.functorPushforward {D : Type u₂} [Category.{v₂} D] (F : D ⥤ C)
{X : D} {T : Presieve X} (x : FamilyOfElements (F.op ⋙ P) T) :
FamilyOfElements P (T.functorPushforward F) := fun Y f h => by
obtain ⟨Z, g, h, h₁, _⟩ := getFunctorPushforwardStructure h
exact P.map h.op (x g h₁)
#align category_theory.presieve.family_of_elements.functor_pushforward CategoryTheory.Presieve.FamilyOfElements.functorPushforward
def FamilyOfElements.compPresheafMap (f : P ⟶ Q) (x : FamilyOfElements P R) :
FamilyOfElements Q R := fun Y g hg => f.app (op Y) (x g hg)
#align category_theory.presieve.family_of_elements.comp_presheaf_map CategoryTheory.Presieve.FamilyOfElements.compPresheafMap
@[simp]
theorem FamilyOfElements.compPresheafMap_id (x : FamilyOfElements P R) :
x.compPresheafMap (𝟙 P) = x :=
rfl
#align category_theory.presieve.family_of_elements.comp_presheaf_map_id CategoryTheory.Presieve.FamilyOfElements.compPresheafMap_id
@[simp]
theorem FamilyOfElements.compPresheafMap_comp (x : FamilyOfElements P R) (f : P ⟶ Q)
(g : Q ⟶ U) : (x.compPresheafMap f).compPresheafMap g = x.compPresheafMap (f ≫ g) :=
rfl
#align category_theory.presieve.family_of_elements.comp_prersheaf_map_comp CategoryTheory.Presieve.FamilyOfElements.compPresheafMap_comp
theorem FamilyOfElements.Compatible.compPresheafMap (f : P ⟶ Q) {x : FamilyOfElements P R}
(h : x.Compatible) : (x.compPresheafMap f).Compatible := by
intro Z₁ Z₂ W g₁ g₂ f₁ f₂ h₁ h₂ eq
unfold FamilyOfElements.compPresheafMap
rwa [← FunctorToTypes.naturality, ← FunctorToTypes.naturality, h]
#align category_theory.presieve.family_of_elements.compatible.comp_presheaf_map CategoryTheory.Presieve.FamilyOfElements.Compatible.compPresheafMap
def FamilyOfElements.IsAmalgamation (x : FamilyOfElements P R) (t : P.obj (op X)) : Prop :=
∀ ⦃Y : C⦄ (f : Y ⟶ X) (h : R f), P.map f.op t = x f h
#align category_theory.presieve.family_of_elements.is_amalgamation CategoryTheory.Presieve.FamilyOfElements.IsAmalgamation
theorem FamilyOfElements.IsAmalgamation.compPresheafMap {x : FamilyOfElements P R} {t} (f : P ⟶ Q)
(h : x.IsAmalgamation t) : (x.compPresheafMap f).IsAmalgamation (f.app (op X) t) := by
intro Y g hg
dsimp [FamilyOfElements.compPresheafMap]
change (f.app _ ≫ Q.map _) _ = _
rw [← f.naturality, types_comp_apply, h g hg]
#align category_theory.presieve.family_of_elements.is_amalgamation.comp_presheaf_map CategoryTheory.Presieve.FamilyOfElements.IsAmalgamation.compPresheafMap
theorem is_compatible_of_exists_amalgamation (x : FamilyOfElements P R)
(h : ∃ t, x.IsAmalgamation t) : x.Compatible := by
cases' h with t ht
intro Y₁ Y₂ Z g₁ g₂ f₁ f₂ h₁ h₂ comm
rw [← ht _ h₁, ← ht _ h₂, ← FunctorToTypes.map_comp_apply, ← op_comp, comm]
simp
#align category_theory.presieve.is_compatible_of_exists_amalgamation CategoryTheory.Presieve.is_compatible_of_exists_amalgamation
theorem isAmalgamation_restrict {R₁ R₂ : Presieve X} (h : R₁ ≤ R₂) (x : FamilyOfElements P R₂)
(t : P.obj (op X)) (ht : x.IsAmalgamation t) : (x.restrict h).IsAmalgamation t := fun Y f hf =>
ht f (h Y hf)
#align category_theory.presieve.is_amalgamation_restrict CategoryTheory.Presieve.isAmalgamation_restrict
theorem isAmalgamation_sieveExtend {R : Presieve X} (x : FamilyOfElements P R) (t : P.obj (op X))
(ht : x.IsAmalgamation t) : x.sieveExtend.IsAmalgamation t := by
intro Y f hf
dsimp [FamilyOfElements.sieveExtend]
rw [← ht _, ← FunctorToTypes.map_comp_apply, ← op_comp, hf.choose_spec.choose_spec.choose_spec.2]
#align category_theory.presieve.is_amalgamation_sieve_extend CategoryTheory.Presieve.isAmalgamation_sieveExtend
def IsSeparatedFor (P : Cᵒᵖ ⥤ Type w) (R : Presieve X) : Prop :=
∀ (x : FamilyOfElements P R) (t₁ t₂), x.IsAmalgamation t₁ → x.IsAmalgamation t₂ → t₁ = t₂
#align category_theory.presieve.is_separated_for CategoryTheory.Presieve.IsSeparatedFor
theorem IsSeparatedFor.ext {R : Presieve X} (hR : IsSeparatedFor P R) {t₁ t₂ : P.obj (op X)}
(h : ∀ ⦃Y⦄ ⦃f : Y ⟶ X⦄ (_ : R f), P.map f.op t₁ = P.map f.op t₂) : t₁ = t₂ :=
hR (fun _ f _ => P.map f.op t₂) t₁ t₂ (fun _ _ hf => h hf) fun _ _ _ => rfl
#align category_theory.presieve.is_separated_for.ext CategoryTheory.Presieve.IsSeparatedFor.ext
theorem isSeparatedFor_iff_generate :
IsSeparatedFor P R ↔ IsSeparatedFor P (generate R : Presieve X) := by
constructor
· intro h x t₁ t₂ ht₁ ht₂
apply h (x.restrict (le_generate R)) t₁ t₂ _ _
· exact isAmalgamation_restrict _ x t₁ ht₁
· exact isAmalgamation_restrict _ x t₂ ht₂
· intro h x t₁ t₂ ht₁ ht₂
apply h x.sieveExtend
· exact isAmalgamation_sieveExtend x t₁ ht₁
· exact isAmalgamation_sieveExtend x t₂ ht₂
#align category_theory.presieve.is_separated_for_iff_generate CategoryTheory.Presieve.isSeparatedFor_iff_generate
theorem isSeparatedFor_top (P : Cᵒᵖ ⥤ Type w) : IsSeparatedFor P (⊤ : Presieve X) :=
fun x t₁ t₂ h₁ h₂ => by
have q₁ := h₁ (𝟙 X) (by tauto)
have q₂ := h₂ (𝟙 X) (by tauto)
simp only [op_id, FunctorToTypes.map_id_apply] at q₁ q₂
rw [q₁, q₂]
#align category_theory.presieve.is_separated_for_top CategoryTheory.Presieve.isSeparatedFor_top
def IsSheafFor (P : Cᵒᵖ ⥤ Type w) (R : Presieve X) : Prop :=
∀ x : FamilyOfElements P R, x.Compatible → ∃! t, x.IsAmalgamation t
#align category_theory.presieve.is_sheaf_for CategoryTheory.Presieve.IsSheafFor
def YonedaSheafCondition (P : Cᵒᵖ ⥤ Type v₁) (S : Sieve X) : Prop :=
∀ f : S.functor ⟶ P, ∃! g, S.functorInclusion ≫ g = f
#align category_theory.presieve.yoneda_sheaf_condition CategoryTheory.Presieve.YonedaSheafCondition
-- TODO: We can generalize the universe parameter v₁ above by composing with
-- appropriate `ulift_functor`s.
def natTransEquivCompatibleFamily {P : Cᵒᵖ ⥤ Type v₁} :
(S.functor ⟶ P) ≃ { x : FamilyOfElements P (S : Presieve X) // x.Compatible } where
toFun α := by
refine ⟨fun Y f hf => ?_, ?_⟩
· apply α.app (op Y) ⟨_, hf⟩
· rw [compatible_iff_sieveCompatible]
intro Y Z f g hf
dsimp
rw [← FunctorToTypes.naturality _ _ α g.op]
rfl
invFun t :=
{ app := fun Y f => t.1 _ f.2
naturality := fun Y Z g => by
ext ⟨f, hf⟩
apply t.2.to_sieveCompatible _ }
left_inv α := by
ext X ⟨_, _⟩
rfl
right_inv := by
rintro ⟨x, hx⟩
rfl
#align category_theory.presieve.nat_trans_equiv_compatible_family CategoryTheory.Presieve.natTransEquivCompatibleFamily
theorem extension_iff_amalgamation {P : Cᵒᵖ ⥤ Type v₁} (x : S.functor ⟶ P) (g : yoneda.obj X ⟶ P) :
S.functorInclusion ≫ g = x ↔
(natTransEquivCompatibleFamily x).1.IsAmalgamation (yonedaEquiv g) := by
change _ ↔ ∀ ⦃Y : C⦄ (f : Y ⟶ X) (h : S f), P.map f.op (yonedaEquiv g) = x.app (op Y) ⟨f, h⟩
constructor
· rintro rfl Y f hf
rw [yonedaEquiv_naturality]
dsimp
simp [yonedaEquiv_apply]
-- See note [dsimp, simp].
· intro h
ext Y ⟨f, hf⟩
convert h f hf
rw [yonedaEquiv_naturality]
dsimp [yonedaEquiv]
simp
#align category_theory.presieve.extension_iff_amalgamation CategoryTheory.Presieve.extension_iff_amalgamation
theorem isSheafFor_iff_yonedaSheafCondition {P : Cᵒᵖ ⥤ Type v₁} :
IsSheafFor P (S : Presieve X) ↔ YonedaSheafCondition P S := by
rw [IsSheafFor, YonedaSheafCondition]
simp_rw [extension_iff_amalgamation]
rw [Equiv.forall_congr_left' natTransEquivCompatibleFamily]
rw [Subtype.forall]
apply forall₂_congr
intro x hx
rw [Equiv.exists_unique_congr_left _]
simp
#align category_theory.presieve.is_sheaf_for_iff_yoneda_sheaf_condition CategoryTheory.Presieve.isSheafFor_iff_yonedaSheafCondition
noncomputable def IsSheafFor.extend {P : Cᵒᵖ ⥤ Type v₁} (h : IsSheafFor P (S : Presieve X))
(f : S.functor ⟶ P) : yoneda.obj X ⟶ P :=
(isSheafFor_iff_yonedaSheafCondition.1 h f).exists.choose
#align category_theory.presieve.is_sheaf_for.extend CategoryTheory.Presieve.IsSheafFor.extend
@[reassoc (attr := simp)]
theorem IsSheafFor.functorInclusion_comp_extend {P : Cᵒᵖ ⥤ Type v₁} (h : IsSheafFor P S)
(f : S.functor ⟶ P) : S.functorInclusion ≫ h.extend f = f :=
(isSheafFor_iff_yonedaSheafCondition.1 h f).exists.choose_spec
#align category_theory.presieve.is_sheaf_for.functor_inclusion_comp_extend CategoryTheory.Presieve.IsSheafFor.functorInclusion_comp_extend
theorem IsSheafFor.unique_extend {P : Cᵒᵖ ⥤ Type v₁} (h : IsSheafFor P S) {f : S.functor ⟶ P}
(t : yoneda.obj X ⟶ P) (ht : S.functorInclusion ≫ t = f) : t = h.extend f :=
(isSheafFor_iff_yonedaSheafCondition.1 h f).unique ht (h.functorInclusion_comp_extend f)
#align category_theory.presieve.is_sheaf_for.unique_extend CategoryTheory.Presieve.IsSheafFor.unique_extend
theorem IsSheafFor.hom_ext {P : Cᵒᵖ ⥤ Type v₁} (h : IsSheafFor P (S : Presieve X))
(t₁ t₂ : yoneda.obj X ⟶ P) (ht : S.functorInclusion ≫ t₁ = S.functorInclusion ≫ t₂) :
t₁ = t₂ :=
(h.unique_extend t₁ ht).trans (h.unique_extend t₂ rfl).symm
#align category_theory.presieve.is_sheaf_for.hom_ext CategoryTheory.Presieve.IsSheafFor.hom_ext
theorem isSeparatedFor_and_exists_isAmalgamation_iff_isSheafFor :
(IsSeparatedFor P R ∧ ∀ x : FamilyOfElements P R, x.Compatible → ∃ t, x.IsAmalgamation t) ↔
IsSheafFor P R := by
rw [IsSeparatedFor, ← forall_and]
apply forall_congr'
intro x
constructor
· intro z hx
exact exists_unique_of_exists_of_unique (z.2 hx) z.1
· intro h
refine ⟨?_, ExistsUnique.exists ∘ h⟩
intro t₁ t₂ ht₁ ht₂
apply (h _).unique ht₁ ht₂
exact is_compatible_of_exists_amalgamation x ⟨_, ht₂⟩
#align category_theory.presieve.is_separated_for_and_exists_is_amalgamation_iff_sheaf_for CategoryTheory.Presieve.isSeparatedFor_and_exists_isAmalgamation_iff_isSheafFor
theorem IsSeparatedFor.isSheafFor (t : IsSeparatedFor P R) :
(∀ x : FamilyOfElements P R, x.Compatible → ∃ t, x.IsAmalgamation t) → IsSheafFor P R := by
rw [← isSeparatedFor_and_exists_isAmalgamation_iff_isSheafFor]
exact And.intro t
#align category_theory.presieve.is_separated_for.is_sheaf_for CategoryTheory.Presieve.IsSeparatedFor.isSheafFor
theorem IsSheafFor.isSeparatedFor : IsSheafFor P R → IsSeparatedFor P R := fun q =>
(isSeparatedFor_and_exists_isAmalgamation_iff_isSheafFor.2 q).1
#align category_theory.presieve.is_sheaf_for.is_separated_for CategoryTheory.Presieve.IsSheafFor.isSeparatedFor
noncomputable def IsSheafFor.amalgamate (t : IsSheafFor P R) (x : FamilyOfElements P R)
(hx : x.Compatible) : P.obj (op X) :=
(t x hx).exists.choose
#align category_theory.presieve.is_sheaf_for.amalgamate CategoryTheory.Presieve.IsSheafFor.amalgamate
theorem IsSheafFor.isAmalgamation (t : IsSheafFor P R) {x : FamilyOfElements P R}
(hx : x.Compatible) : x.IsAmalgamation (t.amalgamate x hx) :=
(t x hx).exists.choose_spec
#align category_theory.presieve.is_sheaf_for.is_amalgamation CategoryTheory.Presieve.IsSheafFor.isAmalgamation
@[simp]
theorem IsSheafFor.valid_glue (t : IsSheafFor P R) {x : FamilyOfElements P R} (hx : x.Compatible)
(f : Y ⟶ X) (Hf : R f) : P.map f.op (t.amalgamate x hx) = x f Hf :=
t.isAmalgamation hx f Hf
#align category_theory.presieve.is_sheaf_for.valid_glue CategoryTheory.Presieve.IsSheafFor.valid_glue
theorem isSheafFor_iff_generate (R : Presieve X) :
IsSheafFor P R ↔ IsSheafFor P (generate R : Presieve X) := by
rw [← isSeparatedFor_and_exists_isAmalgamation_iff_isSheafFor]
rw [← isSeparatedFor_and_exists_isAmalgamation_iff_isSheafFor]
rw [← isSeparatedFor_iff_generate]
apply and_congr (Iff.refl _)
constructor
· intro q x hx
apply Exists.imp _ (q _ (hx.restrict (le_generate R)))
intro t ht
simpa [hx] using isAmalgamation_sieveExtend _ _ ht
· intro q x hx
apply Exists.imp _ (q _ hx.sieveExtend)
intro t ht
simpa [hx] using isAmalgamation_restrict (le_generate R) _ _ ht
#align category_theory.presieve.is_sheaf_for_iff_generate CategoryTheory.Presieve.isSheafFor_iff_generate
| Mathlib/CategoryTheory/Sites/IsSheafFor.lean | 644 | 650 | theorem isSheafFor_singleton_iso (P : Cᵒᵖ ⥤ Type w) : IsSheafFor P (Presieve.singleton (𝟙 X)) := by |
intro x _
refine ⟨x _ (Presieve.singleton_self _), ?_, ?_⟩
· rintro _ _ ⟨rfl, rfl⟩
simp
· intro t ht
simpa using ht _ (Presieve.singleton_self _)
|
import Mathlib.Algebra.Group.Subgroup.Basic
import Mathlib.Data.Fintype.Basic
import Mathlib.Data.List.Sublists
import Mathlib.Data.List.InsertNth
#align_import group_theory.free_group from "leanprover-community/mathlib"@"f93c11933efbc3c2f0299e47b8ff83e9b539cbf6"
open Relation
universe u v w
variable {α : Type u}
attribute [local simp] List.append_eq_has_append
-- Porting note: to_additive.map_namespace is not supported yet
-- worked around it by putting a few extra manual mappings (but not too many all in all)
-- run_cmd to_additive.map_namespace `FreeGroup `FreeAddGroup
inductive FreeAddGroup.Red.Step : List (α × Bool) → List (α × Bool) → Prop
| not {L₁ L₂ x b} : FreeAddGroup.Red.Step (L₁ ++ (x, b) :: (x, not b) :: L₂) (L₁ ++ L₂)
#align free_add_group.red.step FreeAddGroup.Red.Step
attribute [simp] FreeAddGroup.Red.Step.not
@[to_additive FreeAddGroup.Red.Step]
inductive FreeGroup.Red.Step : List (α × Bool) → List (α × Bool) → Prop
| not {L₁ L₂ x b} : FreeGroup.Red.Step (L₁ ++ (x, b) :: (x, not b) :: L₂) (L₁ ++ L₂)
#align free_group.red.step FreeGroup.Red.Step
attribute [simp] FreeGroup.Red.Step.not
namespace FreeGroup
variable {L L₁ L₂ L₃ L₄ : List (α × Bool)}
@[to_additive FreeAddGroup.Red "Reflexive-transitive closure of `Red.Step`"]
def Red : List (α × Bool) → List (α × Bool) → Prop :=
ReflTransGen Red.Step
#align free_group.red FreeGroup.Red
#align free_add_group.red FreeAddGroup.Red
@[to_additive (attr := refl)]
theorem Red.refl : Red L L :=
ReflTransGen.refl
#align free_group.red.refl FreeGroup.Red.refl
#align free_add_group.red.refl FreeAddGroup.Red.refl
@[to_additive (attr := trans)]
theorem Red.trans : Red L₁ L₂ → Red L₂ L₃ → Red L₁ L₃ :=
ReflTransGen.trans
#align free_group.red.trans FreeGroup.Red.trans
#align free_add_group.red.trans FreeAddGroup.Red.trans
namespace Red
@[to_additive "Predicate asserting that the word `w₁` can be reduced to `w₂` in one step, i.e. there
are words `w₃ w₄` and letter `x` such that `w₁ = w₃ + x + (-x) + w₄` and `w₂ = w₃w₄`"]
theorem Step.length : ∀ {L₁ L₂ : List (α × Bool)}, Step L₁ L₂ → L₂.length + 2 = L₁.length
| _, _, @Red.Step.not _ L1 L2 x b => by rw [List.length_append, List.length_append]; rfl
#align free_group.red.step.length FreeGroup.Red.Step.length
#align free_add_group.red.step.length FreeAddGroup.Red.Step.length
@[to_additive (attr := simp)]
theorem Step.not_rev {x b} : Step (L₁ ++ (x, !b) :: (x, b) :: L₂) (L₁ ++ L₂) := by
cases b <;> exact Step.not
#align free_group.red.step.bnot_rev FreeGroup.Red.Step.not_rev
#align free_add_group.red.step.bnot_rev FreeAddGroup.Red.Step.not_rev
@[to_additive (attr := simp)]
theorem Step.cons_not {x b} : Red.Step ((x, b) :: (x, !b) :: L) L :=
@Step.not _ [] _ _ _
#align free_group.red.step.cons_bnot FreeGroup.Red.Step.cons_not
#align free_add_group.red.step.cons_bnot FreeAddGroup.Red.Step.cons_not
@[to_additive (attr := simp)]
theorem Step.cons_not_rev {x b} : Red.Step ((x, !b) :: (x, b) :: L) L :=
@Red.Step.not_rev _ [] _ _ _
#align free_group.red.step.cons_bnot_rev FreeGroup.Red.Step.cons_not_rev
#align free_add_group.red.step.cons_bnot_rev FreeAddGroup.Red.Step.cons_not_rev
@[to_additive]
theorem Step.append_left : ∀ {L₁ L₂ L₃ : List (α × Bool)}, Step L₂ L₃ → Step (L₁ ++ L₂) (L₁ ++ L₃)
| _, _, _, Red.Step.not => by rw [← List.append_assoc, ← List.append_assoc]; constructor
#align free_group.red.step.append_left FreeGroup.Red.Step.append_left
#align free_add_group.red.step.append_left FreeAddGroup.Red.Step.append_left
@[to_additive]
theorem Step.cons {x} (H : Red.Step L₁ L₂) : Red.Step (x :: L₁) (x :: L₂) :=
@Step.append_left _ [x] _ _ H
#align free_group.red.step.cons FreeGroup.Red.Step.cons
#align free_add_group.red.step.cons FreeAddGroup.Red.Step.cons
@[to_additive]
theorem Step.append_right : ∀ {L₁ L₂ L₃ : List (α × Bool)}, Step L₁ L₂ → Step (L₁ ++ L₃) (L₂ ++ L₃)
| _, _, _, Red.Step.not => by simp
#align free_group.red.step.append_right FreeGroup.Red.Step.append_right
#align free_add_group.red.step.append_right FreeAddGroup.Red.Step.append_right
@[to_additive]
theorem not_step_nil : ¬Step [] L := by
generalize h' : [] = L'
intro h
cases' h with L₁ L₂
simp [List.nil_eq_append] at h'
#align free_group.red.not_step_nil FreeGroup.Red.not_step_nil
#align free_add_group.red.not_step_nil FreeAddGroup.Red.not_step_nil
@[to_additive]
theorem Step.cons_left_iff {a : α} {b : Bool} :
Step ((a, b) :: L₁) L₂ ↔ (∃ L, Step L₁ L ∧ L₂ = (a, b) :: L) ∨ L₁ = (a, ! b) :: L₂ := by
constructor
· generalize hL : ((a, b) :: L₁ : List _) = L
rintro @⟨_ | ⟨p, s'⟩, e, a', b'⟩
· simp at hL
simp [*]
· simp at hL
rcases hL with ⟨rfl, rfl⟩
refine Or.inl ⟨s' ++ e, Step.not, ?_⟩
simp
· rintro (⟨L, h, rfl⟩ | rfl)
· exact Step.cons h
· exact Step.cons_not
#align free_group.red.step.cons_left_iff FreeGroup.Red.Step.cons_left_iff
#align free_add_group.red.step.cons_left_iff FreeAddGroup.Red.Step.cons_left_iff
@[to_additive]
theorem not_step_singleton : ∀ {p : α × Bool}, ¬Step [p] L
| (a, b) => by simp [Step.cons_left_iff, not_step_nil]
#align free_group.red.not_step_singleton FreeGroup.Red.not_step_singleton
#align free_add_group.red.not_step_singleton FreeAddGroup.Red.not_step_singleton
@[to_additive]
theorem Step.cons_cons_iff : ∀ {p : α × Bool}, Step (p :: L₁) (p :: L₂) ↔ Step L₁ L₂ := by
simp (config := { contextual := true }) [Step.cons_left_iff, iff_def, or_imp]
#align free_group.red.step.cons_cons_iff FreeGroup.Red.Step.cons_cons_iff
#align free_add_group.red.step.cons_cons_iff FreeAddGroup.Red.Step.cons_cons_iff
@[to_additive]
theorem Step.append_left_iff : ∀ L, Step (L ++ L₁) (L ++ L₂) ↔ Step L₁ L₂
| [] => by simp
| p :: l => by simp [Step.append_left_iff l, Step.cons_cons_iff]
#align free_group.red.step.append_left_iff FreeGroup.Red.Step.append_left_iff
#align free_add_group.red.step.append_left_iff FreeAddGroup.Red.Step.append_left_iff
@[to_additive]
theorem Step.diamond_aux :
∀ {L₁ L₂ L₃ L₄ : List (α × Bool)} {x1 b1 x2 b2},
L₁ ++ (x1, b1) :: (x1, !b1) :: L₂ = L₃ ++ (x2, b2) :: (x2, !b2) :: L₄ →
L₁ ++ L₂ = L₃ ++ L₄ ∨ ∃ L₅, Red.Step (L₁ ++ L₂) L₅ ∧ Red.Step (L₃ ++ L₄) L₅
| [], _, [], _, _, _, _, _, H => by injections; subst_vars; simp
| [], _, [(x3, b3)], _, _, _, _, _, H => by injections; subst_vars; simp
| [(x3, b3)], _, [], _, _, _, _, _, H => by injections; subst_vars; simp
| [], _, (x3, b3) :: (x4, b4) :: tl, _, _, _, _, _, H => by
injections; subst_vars; simp; right; exact ⟨_, Red.Step.not, Red.Step.cons_not⟩
| (x3, b3) :: (x4, b4) :: tl, _, [], _, _, _, _, _, H => by
injections; subst_vars; simp; right; exact ⟨_, Red.Step.cons_not, Red.Step.not⟩
| (x3, b3) :: tl, _, (x4, b4) :: tl2, _, _, _, _, _, H =>
let ⟨H1, H2⟩ := List.cons.inj H
match Step.diamond_aux H2 with
| Or.inl H3 => Or.inl <| by simp [H1, H3]
| Or.inr ⟨L₅, H3, H4⟩ => Or.inr ⟨_, Step.cons H3, by simpa [H1] using Step.cons H4⟩
#align free_group.red.step.diamond_aux FreeGroup.Red.Step.diamond_aux
#align free_add_group.red.step.diamond_aux FreeAddGroup.Red.Step.diamond_aux
@[to_additive]
theorem Step.diamond :
∀ {L₁ L₂ L₃ L₄ : List (α × Bool)},
Red.Step L₁ L₃ → Red.Step L₂ L₄ → L₁ = L₂ → L₃ = L₄ ∨ ∃ L₅, Red.Step L₃ L₅ ∧ Red.Step L₄ L₅
| _, _, _, _, Red.Step.not, Red.Step.not, H => Step.diamond_aux H
#align free_group.red.step.diamond FreeGroup.Red.Step.diamond
#align free_add_group.red.step.diamond FreeAddGroup.Red.Step.diamond
@[to_additive]
theorem Step.to_red : Step L₁ L₂ → Red L₁ L₂ :=
ReflTransGen.single
#align free_group.red.step.to_red FreeGroup.Red.Step.to_red
#align free_add_group.red.step.to_red FreeAddGroup.Red.Step.to_red
@[to_additive
"**Church-Rosser theorem** for word reduction: If `w1 w2 w3` are words such that `w1` reduces
to `w2` and `w3` respectively, then there is a word `w4` such that `w2` and `w3` reduce to `w4`
respectively. This is also known as Newman's diamond lemma."]
theorem church_rosser : Red L₁ L₂ → Red L₁ L₃ → Join Red L₂ L₃ :=
Relation.church_rosser fun a b c hab hac =>
match b, c, Red.Step.diamond hab hac rfl with
| b, _, Or.inl rfl => ⟨b, by rfl, by rfl⟩
| b, c, Or.inr ⟨d, hbd, hcd⟩ => ⟨d, ReflGen.single hbd, hcd.to_red⟩
#align free_group.red.church_rosser FreeGroup.Red.church_rosser
#align free_add_group.red.church_rosser FreeAddGroup.Red.church_rosser
@[to_additive]
theorem cons_cons {p} : Red L₁ L₂ → Red (p :: L₁) (p :: L₂) :=
ReflTransGen.lift (List.cons p) fun _ _ => Step.cons
#align free_group.red.cons_cons FreeGroup.Red.cons_cons
#align free_add_group.red.cons_cons FreeAddGroup.Red.cons_cons
@[to_additive]
theorem cons_cons_iff (p) : Red (p :: L₁) (p :: L₂) ↔ Red L₁ L₂ :=
Iff.intro
(by
generalize eq₁ : (p :: L₁ : List _) = LL₁
generalize eq₂ : (p :: L₂ : List _) = LL₂
intro h
induction' h using Relation.ReflTransGen.head_induction_on
with L₁ L₂ h₁₂ h ih
generalizing L₁ L₂
· subst_vars
cases eq₂
constructor
· subst_vars
cases' p with a b
rw [Step.cons_left_iff] at h₁₂
rcases h₁₂ with (⟨L, h₁₂, rfl⟩ | rfl)
· exact (ih rfl rfl).head h₁₂
· exact (cons_cons h).tail Step.cons_not_rev)
cons_cons
#align free_group.red.cons_cons_iff FreeGroup.Red.cons_cons_iff
#align free_add_group.red.cons_cons_iff FreeAddGroup.Red.cons_cons_iff
@[to_additive]
theorem append_append_left_iff : ∀ L, Red (L ++ L₁) (L ++ L₂) ↔ Red L₁ L₂
| [] => Iff.rfl
| p :: L => by simp [append_append_left_iff L, cons_cons_iff]
#align free_group.red.append_append_left_iff FreeGroup.Red.append_append_left_iff
#align free_add_group.red.append_append_left_iff FreeAddGroup.Red.append_append_left_iff
@[to_additive]
theorem append_append (h₁ : Red L₁ L₃) (h₂ : Red L₂ L₄) : Red (L₁ ++ L₂) (L₃ ++ L₄) :=
(h₁.lift (fun L => L ++ L₂) fun _ _ => Step.append_right).trans ((append_append_left_iff _).2 h₂)
#align free_group.red.append_append FreeGroup.Red.append_append
#align free_add_group.red.append_append FreeAddGroup.Red.append_append
@[to_additive]
theorem to_append_iff : Red L (L₁ ++ L₂) ↔ ∃ L₃ L₄, L = L₃ ++ L₄ ∧ Red L₃ L₁ ∧ Red L₄ L₂ :=
Iff.intro
(by
generalize eq : L₁ ++ L₂ = L₁₂
intro h
induction' h with L' L₁₂ hLL' h ih generalizing L₁ L₂
· exact ⟨_, _, eq.symm, by rfl, by rfl⟩
· cases' h with s e a b
rcases List.append_eq_append_iff.1 eq with (⟨s', rfl, rfl⟩ | ⟨e', rfl, rfl⟩)
· have : L₁ ++ (s' ++ (a, b) :: (a, not b) :: e) = L₁ ++ s' ++ (a, b) :: (a, not b) :: e :=
by simp
rcases ih this with ⟨w₁, w₂, rfl, h₁, h₂⟩
exact ⟨w₁, w₂, rfl, h₁, h₂.tail Step.not⟩
· have : s ++ (a, b) :: (a, not b) :: e' ++ L₂ = s ++ (a, b) :: (a, not b) :: (e' ++ L₂) :=
by simp
rcases ih this with ⟨w₁, w₂, rfl, h₁, h₂⟩
exact ⟨w₁, w₂, rfl, h₁.tail Step.not, h₂⟩)
fun ⟨L₃, L₄, Eq, h₃, h₄⟩ => Eq.symm ▸ append_append h₃ h₄
#align free_group.red.to_append_iff FreeGroup.Red.to_append_iff
#align free_add_group.red.to_append_iff FreeAddGroup.Red.to_append_iff
@[to_additive "The empty word `[]` only reduces to itself."]
theorem nil_iff : Red [] L ↔ L = [] :=
reflTransGen_iff_eq fun _ => Red.not_step_nil
#align free_group.red.nil_iff FreeGroup.Red.nil_iff
#align free_add_group.red.nil_iff FreeAddGroup.Red.nil_iff
@[to_additive "A letter only reduces to itself."]
theorem singleton_iff {x} : Red [x] L₁ ↔ L₁ = [x] :=
reflTransGen_iff_eq fun _ => not_step_singleton
#align free_group.red.singleton_iff FreeGroup.Red.singleton_iff
#align free_add_group.red.singleton_iff FreeAddGroup.Red.singleton_iff
@[to_additive
"If `x` is a letter and `w` is a word such that `x + w` reduces to the empty word, then `w`
reduces to `-x`."]
theorem cons_nil_iff_singleton {x b} : Red ((x, b) :: L) [] ↔ Red L [(x, not b)] :=
Iff.intro
(fun h => by
have h₁ : Red ((x, not b) :: (x, b) :: L) [(x, not b)] := cons_cons h
have h₂ : Red ((x, not b) :: (x, b) :: L) L := ReflTransGen.single Step.cons_not_rev
let ⟨L', h₁, h₂⟩ := church_rosser h₁ h₂
rw [singleton_iff] at h₁
subst L'
assumption)
fun h => (cons_cons h).tail Step.cons_not
#align free_group.red.cons_nil_iff_singleton FreeGroup.Red.cons_nil_iff_singleton
#align free_add_group.red.cons_nil_iff_singleton FreeAddGroup.Red.cons_nil_iff_singleton
@[to_additive]
| Mathlib/GroupTheory/FreeGroup/Basic.lean | 342 | 350 | theorem red_iff_irreducible {x1 b1 x2 b2} (h : (x1, b1) ≠ (x2, b2)) :
Red [(x1, !b1), (x2, b2)] L ↔ L = [(x1, !b1), (x2, b2)] := by |
apply reflTransGen_iff_eq
generalize eq : [(x1, not b1), (x2, b2)] = L'
intro L h'
cases h'
simp [List.cons_eq_append, List.nil_eq_append] at eq
rcases eq with ⟨rfl, ⟨rfl, rfl⟩, ⟨rfl, rfl⟩, rfl⟩
simp at h
|
import Mathlib.Logic.Pairwise
import Mathlib.Order.CompleteBooleanAlgebra
import Mathlib.Order.Directed
import Mathlib.Order.GaloisConnection
#align_import data.set.lattice from "leanprover-community/mathlib"@"b86832321b586c6ac23ef8cdef6a7a27e42b13bd"
open Function Set
universe u
variable {α β γ : Type*} {ι ι' ι₂ : Sort*} {κ κ₁ κ₂ : ι → Sort*} {κ' : ι' → Sort*}
namespace Set
theorem mem_iUnion₂ {x : γ} {s : ∀ i, κ i → Set γ} : (x ∈ ⋃ (i) (j), s i j) ↔ ∃ i j, x ∈ s i j := by
simp_rw [mem_iUnion]
#align set.mem_Union₂ Set.mem_iUnion₂
theorem mem_iInter₂ {x : γ} {s : ∀ i, κ i → Set γ} : (x ∈ ⋂ (i) (j), s i j) ↔ ∀ i j, x ∈ s i j := by
simp_rw [mem_iInter]
#align set.mem_Inter₂ Set.mem_iInter₂
theorem mem_iUnion_of_mem {s : ι → Set α} {a : α} (i : ι) (ha : a ∈ s i) : a ∈ ⋃ i, s i :=
mem_iUnion.2 ⟨i, ha⟩
#align set.mem_Union_of_mem Set.mem_iUnion_of_mem
theorem mem_iUnion₂_of_mem {s : ∀ i, κ i → Set α} {a : α} {i : ι} (j : κ i) (ha : a ∈ s i j) :
a ∈ ⋃ (i) (j), s i j :=
mem_iUnion₂.2 ⟨i, j, ha⟩
#align set.mem_Union₂_of_mem Set.mem_iUnion₂_of_mem
theorem mem_iInter_of_mem {s : ι → Set α} {a : α} (h : ∀ i, a ∈ s i) : a ∈ ⋂ i, s i :=
mem_iInter.2 h
#align set.mem_Inter_of_mem Set.mem_iInter_of_mem
theorem mem_iInter₂_of_mem {s : ∀ i, κ i → Set α} {a : α} (h : ∀ i j, a ∈ s i j) :
a ∈ ⋂ (i) (j), s i j :=
mem_iInter₂.2 h
#align set.mem_Inter₂_of_mem Set.mem_iInter₂_of_mem
instance completeAtomicBooleanAlgebra : CompleteAtomicBooleanAlgebra (Set α) :=
{ instBooleanAlgebraSet with
le_sSup := fun s t t_in a a_in => ⟨t, t_in, a_in⟩
sSup_le := fun s t h a ⟨t', ⟨t'_in, a_in⟩⟩ => h t' t'_in a_in
le_sInf := fun s t h a a_in t' t'_in => h t' t'_in a_in
sInf_le := fun s t t_in a h => h _ t_in
iInf_iSup_eq := by intros; ext; simp [Classical.skolem] }
instance : OrderTop (Set α) where
top := univ
le_top := by simp
@[congr]
theorem iUnion_congr_Prop {p q : Prop} {f₁ : p → Set α} {f₂ : q → Set α} (pq : p ↔ q)
(f : ∀ x, f₁ (pq.mpr x) = f₂ x) : iUnion f₁ = iUnion f₂ :=
iSup_congr_Prop pq f
#align set.Union_congr_Prop Set.iUnion_congr_Prop
@[congr]
theorem iInter_congr_Prop {p q : Prop} {f₁ : p → Set α} {f₂ : q → Set α} (pq : p ↔ q)
(f : ∀ x, f₁ (pq.mpr x) = f₂ x) : iInter f₁ = iInter f₂ :=
iInf_congr_Prop pq f
#align set.Inter_congr_Prop Set.iInter_congr_Prop
theorem iUnion_plift_up (f : PLift ι → Set α) : ⋃ i, f (PLift.up i) = ⋃ i, f i :=
iSup_plift_up _
#align set.Union_plift_up Set.iUnion_plift_up
theorem iUnion_plift_down (f : ι → Set α) : ⋃ i, f (PLift.down i) = ⋃ i, f i :=
iSup_plift_down _
#align set.Union_plift_down Set.iUnion_plift_down
theorem iInter_plift_up (f : PLift ι → Set α) : ⋂ i, f (PLift.up i) = ⋂ i, f i :=
iInf_plift_up _
#align set.Inter_plift_up Set.iInter_plift_up
theorem iInter_plift_down (f : ι → Set α) : ⋂ i, f (PLift.down i) = ⋂ i, f i :=
iInf_plift_down _
#align set.Inter_plift_down Set.iInter_plift_down
theorem iUnion_eq_if {p : Prop} [Decidable p] (s : Set α) : ⋃ _ : p, s = if p then s else ∅ :=
iSup_eq_if _
#align set.Union_eq_if Set.iUnion_eq_if
theorem iUnion_eq_dif {p : Prop} [Decidable p] (s : p → Set α) :
⋃ h : p, s h = if h : p then s h else ∅ :=
iSup_eq_dif _
#align set.Union_eq_dif Set.iUnion_eq_dif
theorem iInter_eq_if {p : Prop} [Decidable p] (s : Set α) : ⋂ _ : p, s = if p then s else univ :=
iInf_eq_if _
#align set.Inter_eq_if Set.iInter_eq_if
theorem iInf_eq_dif {p : Prop} [Decidable p] (s : p → Set α) :
⋂ h : p, s h = if h : p then s h else univ :=
_root_.iInf_eq_dif _
#align set.Infi_eq_dif Set.iInf_eq_dif
theorem exists_set_mem_of_union_eq_top {ι : Type*} (t : Set ι) (s : ι → Set β)
(w : ⋃ i ∈ t, s i = ⊤) (x : β) : ∃ i ∈ t, x ∈ s i := by
have p : x ∈ ⊤ := Set.mem_univ x
rw [← w, Set.mem_iUnion] at p
simpa using p
#align set.exists_set_mem_of_union_eq_top Set.exists_set_mem_of_union_eq_top
theorem nonempty_of_union_eq_top_of_nonempty {ι : Type*} (t : Set ι) (s : ι → Set α)
(H : Nonempty α) (w : ⋃ i ∈ t, s i = ⊤) : t.Nonempty := by
obtain ⟨x, m, -⟩ := exists_set_mem_of_union_eq_top t s w H.some
exact ⟨x, m⟩
#align set.nonempty_of_union_eq_top_of_nonempty Set.nonempty_of_union_eq_top_of_nonempty
theorem nonempty_of_nonempty_iUnion
{s : ι → Set α} (h_Union : (⋃ i, s i).Nonempty) : Nonempty ι := by
obtain ⟨x, hx⟩ := h_Union
exact ⟨Classical.choose <| mem_iUnion.mp hx⟩
theorem nonempty_of_nonempty_iUnion_eq_univ
{s : ι → Set α} [Nonempty α] (h_Union : ⋃ i, s i = univ) : Nonempty ι :=
nonempty_of_nonempty_iUnion (s := s) (by simpa only [h_Union] using univ_nonempty)
theorem setOf_exists (p : ι → β → Prop) : { x | ∃ i, p i x } = ⋃ i, { x | p i x } :=
ext fun _ => mem_iUnion.symm
#align set.set_of_exists Set.setOf_exists
theorem setOf_forall (p : ι → β → Prop) : { x | ∀ i, p i x } = ⋂ i, { x | p i x } :=
ext fun _ => mem_iInter.symm
#align set.set_of_forall Set.setOf_forall
theorem iUnion_subset {s : ι → Set α} {t : Set α} (h : ∀ i, s i ⊆ t) : ⋃ i, s i ⊆ t :=
iSup_le h
#align set.Union_subset Set.iUnion_subset
theorem iUnion₂_subset {s : ∀ i, κ i → Set α} {t : Set α} (h : ∀ i j, s i j ⊆ t) :
⋃ (i) (j), s i j ⊆ t :=
iUnion_subset fun x => iUnion_subset (h x)
#align set.Union₂_subset Set.iUnion₂_subset
theorem subset_iInter {t : Set β} {s : ι → Set β} (h : ∀ i, t ⊆ s i) : t ⊆ ⋂ i, s i :=
le_iInf h
#align set.subset_Inter Set.subset_iInter
theorem subset_iInter₂ {s : Set α} {t : ∀ i, κ i → Set α} (h : ∀ i j, s ⊆ t i j) :
s ⊆ ⋂ (i) (j), t i j :=
subset_iInter fun x => subset_iInter <| h x
#align set.subset_Inter₂ Set.subset_iInter₂
@[simp]
theorem iUnion_subset_iff {s : ι → Set α} {t : Set α} : ⋃ i, s i ⊆ t ↔ ∀ i, s i ⊆ t :=
⟨fun h _ => Subset.trans (le_iSup s _) h, iUnion_subset⟩
#align set.Union_subset_iff Set.iUnion_subset_iff
theorem iUnion₂_subset_iff {s : ∀ i, κ i → Set α} {t : Set α} :
⋃ (i) (j), s i j ⊆ t ↔ ∀ i j, s i j ⊆ t := by simp_rw [iUnion_subset_iff]
#align set.Union₂_subset_iff Set.iUnion₂_subset_iff
@[simp]
theorem subset_iInter_iff {s : Set α} {t : ι → Set α} : (s ⊆ ⋂ i, t i) ↔ ∀ i, s ⊆ t i :=
le_iInf_iff
#align set.subset_Inter_iff Set.subset_iInter_iff
-- Porting note (#10618): removing `simp`. `simp` can prove it
theorem subset_iInter₂_iff {s : Set α} {t : ∀ i, κ i → Set α} :
(s ⊆ ⋂ (i) (j), t i j) ↔ ∀ i j, s ⊆ t i j := by simp_rw [subset_iInter_iff]
#align set.subset_Inter₂_iff Set.subset_iInter₂_iff
theorem subset_iUnion : ∀ (s : ι → Set β) (i : ι), s i ⊆ ⋃ i, s i :=
le_iSup
#align set.subset_Union Set.subset_iUnion
theorem iInter_subset : ∀ (s : ι → Set β) (i : ι), ⋂ i, s i ⊆ s i :=
iInf_le
#align set.Inter_subset Set.iInter_subset
theorem subset_iUnion₂ {s : ∀ i, κ i → Set α} (i : ι) (j : κ i) : s i j ⊆ ⋃ (i') (j'), s i' j' :=
le_iSup₂ i j
#align set.subset_Union₂ Set.subset_iUnion₂
theorem iInter₂_subset {s : ∀ i, κ i → Set α} (i : ι) (j : κ i) : ⋂ (i) (j), s i j ⊆ s i j :=
iInf₂_le i j
#align set.Inter₂_subset Set.iInter₂_subset
theorem subset_iUnion_of_subset {s : Set α} {t : ι → Set α} (i : ι) (h : s ⊆ t i) : s ⊆ ⋃ i, t i :=
le_iSup_of_le i h
#align set.subset_Union_of_subset Set.subset_iUnion_of_subset
theorem iInter_subset_of_subset {s : ι → Set α} {t : Set α} (i : ι) (h : s i ⊆ t) :
⋂ i, s i ⊆ t :=
iInf_le_of_le i h
#align set.Inter_subset_of_subset Set.iInter_subset_of_subset
theorem subset_iUnion₂_of_subset {s : Set α} {t : ∀ i, κ i → Set α} (i : ι) (j : κ i)
(h : s ⊆ t i j) : s ⊆ ⋃ (i) (j), t i j :=
le_iSup₂_of_le i j h
#align set.subset_Union₂_of_subset Set.subset_iUnion₂_of_subset
theorem iInter₂_subset_of_subset {s : ∀ i, κ i → Set α} {t : Set α} (i : ι) (j : κ i)
(h : s i j ⊆ t) : ⋂ (i) (j), s i j ⊆ t :=
iInf₂_le_of_le i j h
#align set.Inter₂_subset_of_subset Set.iInter₂_subset_of_subset
theorem iUnion_mono {s t : ι → Set α} (h : ∀ i, s i ⊆ t i) : ⋃ i, s i ⊆ ⋃ i, t i :=
iSup_mono h
#align set.Union_mono Set.iUnion_mono
@[gcongr]
theorem iUnion_mono'' {s t : ι → Set α} (h : ∀ i, s i ⊆ t i) : iUnion s ⊆ iUnion t :=
iSup_mono h
theorem iUnion₂_mono {s t : ∀ i, κ i → Set α} (h : ∀ i j, s i j ⊆ t i j) :
⋃ (i) (j), s i j ⊆ ⋃ (i) (j), t i j :=
iSup₂_mono h
#align set.Union₂_mono Set.iUnion₂_mono
theorem iInter_mono {s t : ι → Set α} (h : ∀ i, s i ⊆ t i) : ⋂ i, s i ⊆ ⋂ i, t i :=
iInf_mono h
#align set.Inter_mono Set.iInter_mono
@[gcongr]
theorem iInter_mono'' {s t : ι → Set α} (h : ∀ i, s i ⊆ t i) : iInter s ⊆ iInter t :=
iInf_mono h
theorem iInter₂_mono {s t : ∀ i, κ i → Set α} (h : ∀ i j, s i j ⊆ t i j) :
⋂ (i) (j), s i j ⊆ ⋂ (i) (j), t i j :=
iInf₂_mono h
#align set.Inter₂_mono Set.iInter₂_mono
theorem iUnion_mono' {s : ι → Set α} {t : ι₂ → Set α} (h : ∀ i, ∃ j, s i ⊆ t j) :
⋃ i, s i ⊆ ⋃ i, t i :=
iSup_mono' h
#align set.Union_mono' Set.iUnion_mono'
theorem iUnion₂_mono' {s : ∀ i, κ i → Set α} {t : ∀ i', κ' i' → Set α}
(h : ∀ i j, ∃ i' j', s i j ⊆ t i' j') : ⋃ (i) (j), s i j ⊆ ⋃ (i') (j'), t i' j' :=
iSup₂_mono' h
#align set.Union₂_mono' Set.iUnion₂_mono'
theorem iInter_mono' {s : ι → Set α} {t : ι' → Set α} (h : ∀ j, ∃ i, s i ⊆ t j) :
⋂ i, s i ⊆ ⋂ j, t j :=
Set.subset_iInter fun j =>
let ⟨i, hi⟩ := h j
iInter_subset_of_subset i hi
#align set.Inter_mono' Set.iInter_mono'
theorem iInter₂_mono' {s : ∀ i, κ i → Set α} {t : ∀ i', κ' i' → Set α}
(h : ∀ i' j', ∃ i j, s i j ⊆ t i' j') : ⋂ (i) (j), s i j ⊆ ⋂ (i') (j'), t i' j' :=
subset_iInter₂_iff.2 fun i' j' =>
let ⟨_, _, hst⟩ := h i' j'
(iInter₂_subset _ _).trans hst
#align set.Inter₂_mono' Set.iInter₂_mono'
theorem iUnion₂_subset_iUnion (κ : ι → Sort*) (s : ι → Set α) :
⋃ (i) (_ : κ i), s i ⊆ ⋃ i, s i :=
iUnion_mono fun _ => iUnion_subset fun _ => Subset.rfl
#align set.Union₂_subset_Union Set.iUnion₂_subset_iUnion
theorem iInter_subset_iInter₂ (κ : ι → Sort*) (s : ι → Set α) :
⋂ i, s i ⊆ ⋂ (i) (_ : κ i), s i :=
iInter_mono fun _ => subset_iInter fun _ => Subset.rfl
#align set.Inter_subset_Inter₂ Set.iInter_subset_iInter₂
theorem iUnion_setOf (P : ι → α → Prop) : ⋃ i, { x : α | P i x } = { x : α | ∃ i, P i x } := by
ext
exact mem_iUnion
#align set.Union_set_of Set.iUnion_setOf
theorem iInter_setOf (P : ι → α → Prop) : ⋂ i, { x : α | P i x } = { x : α | ∀ i, P i x } := by
ext
exact mem_iInter
#align set.Inter_set_of Set.iInter_setOf
theorem iUnion_congr_of_surjective {f : ι → Set α} {g : ι₂ → Set α} (h : ι → ι₂) (h1 : Surjective h)
(h2 : ∀ x, g (h x) = f x) : ⋃ x, f x = ⋃ y, g y :=
h1.iSup_congr h h2
#align set.Union_congr_of_surjective Set.iUnion_congr_of_surjective
theorem iInter_congr_of_surjective {f : ι → Set α} {g : ι₂ → Set α} (h : ι → ι₂) (h1 : Surjective h)
(h2 : ∀ x, g (h x) = f x) : ⋂ x, f x = ⋂ y, g y :=
h1.iInf_congr h h2
#align set.Inter_congr_of_surjective Set.iInter_congr_of_surjective
lemma iUnion_congr {s t : ι → Set α} (h : ∀ i, s i = t i) : ⋃ i, s i = ⋃ i, t i := iSup_congr h
#align set.Union_congr Set.iUnion_congr
lemma iInter_congr {s t : ι → Set α} (h : ∀ i, s i = t i) : ⋂ i, s i = ⋂ i, t i := iInf_congr h
#align set.Inter_congr Set.iInter_congr
lemma iUnion₂_congr {s t : ∀ i, κ i → Set α} (h : ∀ i j, s i j = t i j) :
⋃ (i) (j), s i j = ⋃ (i) (j), t i j :=
iUnion_congr fun i => iUnion_congr <| h i
#align set.Union₂_congr Set.iUnion₂_congr
lemma iInter₂_congr {s t : ∀ i, κ i → Set α} (h : ∀ i j, s i j = t i j) :
⋂ (i) (j), s i j = ⋂ (i) (j), t i j :=
iInter_congr fun i => iInter_congr <| h i
#align set.Inter₂_congr Set.iInter₂_congr
@[simp]
theorem compl_iUnion (s : ι → Set β) : (⋃ i, s i)ᶜ = ⋂ i, (s i)ᶜ :=
compl_iSup
#align set.compl_Union Set.compl_iUnion
theorem compl_iUnion₂ (s : ∀ i, κ i → Set α) : (⋃ (i) (j), s i j)ᶜ = ⋂ (i) (j), (s i j)ᶜ := by
simp_rw [compl_iUnion]
#align set.compl_Union₂ Set.compl_iUnion₂
@[simp]
theorem compl_iInter (s : ι → Set β) : (⋂ i, s i)ᶜ = ⋃ i, (s i)ᶜ :=
compl_iInf
#align set.compl_Inter Set.compl_iInter
theorem compl_iInter₂ (s : ∀ i, κ i → Set α) : (⋂ (i) (j), s i j)ᶜ = ⋃ (i) (j), (s i j)ᶜ := by
simp_rw [compl_iInter]
#align set.compl_Inter₂ Set.compl_iInter₂
-- classical -- complete_boolean_algebra
theorem iUnion_eq_compl_iInter_compl (s : ι → Set β) : ⋃ i, s i = (⋂ i, (s i)ᶜ)ᶜ := by
simp only [compl_iInter, compl_compl]
#align set.Union_eq_compl_Inter_compl Set.iUnion_eq_compl_iInter_compl
-- classical -- complete_boolean_algebra
theorem iInter_eq_compl_iUnion_compl (s : ι → Set β) : ⋂ i, s i = (⋃ i, (s i)ᶜ)ᶜ := by
simp only [compl_iUnion, compl_compl]
#align set.Inter_eq_compl_Union_compl Set.iInter_eq_compl_iUnion_compl
theorem inter_iUnion (s : Set β) (t : ι → Set β) : (s ∩ ⋃ i, t i) = ⋃ i, s ∩ t i :=
inf_iSup_eq _ _
#align set.inter_Union Set.inter_iUnion
theorem iUnion_inter (s : Set β) (t : ι → Set β) : (⋃ i, t i) ∩ s = ⋃ i, t i ∩ s :=
iSup_inf_eq _ _
#align set.Union_inter Set.iUnion_inter
theorem iUnion_union_distrib (s : ι → Set β) (t : ι → Set β) :
⋃ i, s i ∪ t i = (⋃ i, s i) ∪ ⋃ i, t i :=
iSup_sup_eq
#align set.Union_union_distrib Set.iUnion_union_distrib
theorem iInter_inter_distrib (s : ι → Set β) (t : ι → Set β) :
⋂ i, s i ∩ t i = (⋂ i, s i) ∩ ⋂ i, t i :=
iInf_inf_eq
#align set.Inter_inter_distrib Set.iInter_inter_distrib
theorem union_iUnion [Nonempty ι] (s : Set β) (t : ι → Set β) : (s ∪ ⋃ i, t i) = ⋃ i, s ∪ t i :=
sup_iSup
#align set.union_Union Set.union_iUnion
theorem iUnion_union [Nonempty ι] (s : Set β) (t : ι → Set β) : (⋃ i, t i) ∪ s = ⋃ i, t i ∪ s :=
iSup_sup
#align set.Union_union Set.iUnion_union
theorem inter_iInter [Nonempty ι] (s : Set β) (t : ι → Set β) : (s ∩ ⋂ i, t i) = ⋂ i, s ∩ t i :=
inf_iInf
#align set.inter_Inter Set.inter_iInter
theorem iInter_inter [Nonempty ι] (s : Set β) (t : ι → Set β) : (⋂ i, t i) ∩ s = ⋂ i, t i ∩ s :=
iInf_inf
#align set.Inter_inter Set.iInter_inter
-- classical
theorem union_iInter (s : Set β) (t : ι → Set β) : (s ∪ ⋂ i, t i) = ⋂ i, s ∪ t i :=
sup_iInf_eq _ _
#align set.union_Inter Set.union_iInter
theorem iInter_union (s : ι → Set β) (t : Set β) : (⋂ i, s i) ∪ t = ⋂ i, s i ∪ t :=
iInf_sup_eq _ _
#align set.Inter_union Set.iInter_union
theorem iUnion_diff (s : Set β) (t : ι → Set β) : (⋃ i, t i) \ s = ⋃ i, t i \ s :=
iUnion_inter _ _
#align set.Union_diff Set.iUnion_diff
theorem diff_iUnion [Nonempty ι] (s : Set β) (t : ι → Set β) : (s \ ⋃ i, t i) = ⋂ i, s \ t i := by
rw [diff_eq, compl_iUnion, inter_iInter]; rfl
#align set.diff_Union Set.diff_iUnion
theorem diff_iInter (s : Set β) (t : ι → Set β) : (s \ ⋂ i, t i) = ⋃ i, s \ t i := by
rw [diff_eq, compl_iInter, inter_iUnion]; rfl
#align set.diff_Inter Set.diff_iInter
theorem iUnion_inter_subset {ι α} {s t : ι → Set α} : ⋃ i, s i ∩ t i ⊆ (⋃ i, s i) ∩ ⋃ i, t i :=
le_iSup_inf_iSup s t
#align set.Union_inter_subset Set.iUnion_inter_subset
theorem iUnion_inter_of_monotone {ι α} [Preorder ι] [IsDirected ι (· ≤ ·)] {s t : ι → Set α}
(hs : Monotone s) (ht : Monotone t) : ⋃ i, s i ∩ t i = (⋃ i, s i) ∩ ⋃ i, t i :=
iSup_inf_of_monotone hs ht
#align set.Union_inter_of_monotone Set.iUnion_inter_of_monotone
theorem iUnion_inter_of_antitone {ι α} [Preorder ι] [IsDirected ι (swap (· ≤ ·))] {s t : ι → Set α}
(hs : Antitone s) (ht : Antitone t) : ⋃ i, s i ∩ t i = (⋃ i, s i) ∩ ⋃ i, t i :=
iSup_inf_of_antitone hs ht
#align set.Union_inter_of_antitone Set.iUnion_inter_of_antitone
theorem iInter_union_of_monotone {ι α} [Preorder ι] [IsDirected ι (swap (· ≤ ·))] {s t : ι → Set α}
(hs : Monotone s) (ht : Monotone t) : ⋂ i, s i ∪ t i = (⋂ i, s i) ∪ ⋂ i, t i :=
iInf_sup_of_monotone hs ht
#align set.Inter_union_of_monotone Set.iInter_union_of_monotone
theorem iInter_union_of_antitone {ι α} [Preorder ι] [IsDirected ι (· ≤ ·)] {s t : ι → Set α}
(hs : Antitone s) (ht : Antitone t) : ⋂ i, s i ∪ t i = (⋂ i, s i) ∪ ⋂ i, t i :=
iInf_sup_of_antitone hs ht
#align set.Inter_union_of_antitone Set.iInter_union_of_antitone
theorem iUnion_iInter_subset {s : ι → ι' → Set α} : (⋃ j, ⋂ i, s i j) ⊆ ⋂ i, ⋃ j, s i j :=
iSup_iInf_le_iInf_iSup (flip s)
#align set.Union_Inter_subset Set.iUnion_iInter_subset
theorem iUnion_option {ι} (s : Option ι → Set α) : ⋃ o, s o = s none ∪ ⋃ i, s (some i) :=
iSup_option s
#align set.Union_option Set.iUnion_option
theorem iInter_option {ι} (s : Option ι → Set α) : ⋂ o, s o = s none ∩ ⋂ i, s (some i) :=
iInf_option s
#align set.Inter_option Set.iInter_option
section
variable (p : ι → Prop) [DecidablePred p]
theorem iUnion_dite (f : ∀ i, p i → Set α) (g : ∀ i, ¬p i → Set α) :
⋃ i, (if h : p i then f i h else g i h) = (⋃ (i) (h : p i), f i h) ∪ ⋃ (i) (h : ¬p i), g i h :=
iSup_dite _ _ _
#align set.Union_dite Set.iUnion_dite
theorem iUnion_ite (f g : ι → Set α) :
⋃ i, (if p i then f i else g i) = (⋃ (i) (_ : p i), f i) ∪ ⋃ (i) (_ : ¬p i), g i :=
iUnion_dite _ _ _
#align set.Union_ite Set.iUnion_ite
theorem iInter_dite (f : ∀ i, p i → Set α) (g : ∀ i, ¬p i → Set α) :
⋂ i, (if h : p i then f i h else g i h) = (⋂ (i) (h : p i), f i h) ∩ ⋂ (i) (h : ¬p i), g i h :=
iInf_dite _ _ _
#align set.Inter_dite Set.iInter_dite
theorem iInter_ite (f g : ι → Set α) :
⋂ i, (if p i then f i else g i) = (⋂ (i) (_ : p i), f i) ∩ ⋂ (i) (_ : ¬p i), g i :=
iInter_dite _ _ _
#align set.Inter_ite Set.iInter_ite
end
theorem image_projection_prod {ι : Type*} {α : ι → Type*} {v : ∀ i : ι, Set (α i)}
(hv : (pi univ v).Nonempty) (i : ι) :
((fun x : ∀ i : ι, α i => x i) '' ⋂ k, (fun x : ∀ j : ι, α j => x k) ⁻¹' v k) = v i := by
classical
apply Subset.antisymm
· simp [iInter_subset]
· intro y y_in
simp only [mem_image, mem_iInter, mem_preimage]
rcases hv with ⟨z, hz⟩
refine ⟨Function.update z i y, ?_, update_same i y z⟩
rw [@forall_update_iff ι α _ z i y fun i t => t ∈ v i]
exact ⟨y_in, fun j _ => by simpa using hz j⟩
#align set.image_projection_prod Set.image_projection_prod
theorem iInter_false {s : False → Set α} : iInter s = univ :=
iInf_false
#align set.Inter_false Set.iInter_false
theorem iUnion_false {s : False → Set α} : iUnion s = ∅ :=
iSup_false
#align set.Union_false Set.iUnion_false
@[simp]
theorem iInter_true {s : True → Set α} : iInter s = s trivial :=
iInf_true
#align set.Inter_true Set.iInter_true
@[simp]
theorem iUnion_true {s : True → Set α} : iUnion s = s trivial :=
iSup_true
#align set.Union_true Set.iUnion_true
@[simp]
theorem iInter_exists {p : ι → Prop} {f : Exists p → Set α} :
⋂ x, f x = ⋂ (i) (h : p i), f ⟨i, h⟩ :=
iInf_exists
#align set.Inter_exists Set.iInter_exists
@[simp]
theorem iUnion_exists {p : ι → Prop} {f : Exists p → Set α} :
⋃ x, f x = ⋃ (i) (h : p i), f ⟨i, h⟩ :=
iSup_exists
#align set.Union_exists Set.iUnion_exists
@[simp]
theorem iUnion_empty : (⋃ _ : ι, ∅ : Set α) = ∅ :=
iSup_bot
#align set.Union_empty Set.iUnion_empty
@[simp]
theorem iInter_univ : (⋂ _ : ι, univ : Set α) = univ :=
iInf_top
#align set.Inter_univ Set.iInter_univ
section
variable {s : ι → Set α}
@[simp]
theorem iUnion_eq_empty : ⋃ i, s i = ∅ ↔ ∀ i, s i = ∅ :=
iSup_eq_bot
#align set.Union_eq_empty Set.iUnion_eq_empty
@[simp]
theorem iInter_eq_univ : ⋂ i, s i = univ ↔ ∀ i, s i = univ :=
iInf_eq_top
#align set.Inter_eq_univ Set.iInter_eq_univ
@[simp]
theorem nonempty_iUnion : (⋃ i, s i).Nonempty ↔ ∃ i, (s i).Nonempty := by
simp [nonempty_iff_ne_empty]
#align set.nonempty_Union Set.nonempty_iUnion
-- Porting note (#10618): removing `simp`. `simp` can prove it
theorem nonempty_biUnion {t : Set α} {s : α → Set β} :
(⋃ i ∈ t, s i).Nonempty ↔ ∃ i ∈ t, (s i).Nonempty := by simp
#align set.nonempty_bUnion Set.nonempty_biUnion
theorem iUnion_nonempty_index (s : Set α) (t : s.Nonempty → Set β) :
⋃ h, t h = ⋃ x ∈ s, t ⟨x, ‹_›⟩ :=
iSup_exists
#align set.Union_nonempty_index Set.iUnion_nonempty_index
end
@[simp]
theorem iInter_iInter_eq_left {b : β} {s : ∀ x : β, x = b → Set α} :
⋂ (x) (h : x = b), s x h = s b rfl :=
iInf_iInf_eq_left
#align set.Inter_Inter_eq_left Set.iInter_iInter_eq_left
@[simp]
theorem iInter_iInter_eq_right {b : β} {s : ∀ x : β, b = x → Set α} :
⋂ (x) (h : b = x), s x h = s b rfl :=
iInf_iInf_eq_right
#align set.Inter_Inter_eq_right Set.iInter_iInter_eq_right
@[simp]
theorem iUnion_iUnion_eq_left {b : β} {s : ∀ x : β, x = b → Set α} :
⋃ (x) (h : x = b), s x h = s b rfl :=
iSup_iSup_eq_left
#align set.Union_Union_eq_left Set.iUnion_iUnion_eq_left
@[simp]
theorem iUnion_iUnion_eq_right {b : β} {s : ∀ x : β, b = x → Set α} :
⋃ (x) (h : b = x), s x h = s b rfl :=
iSup_iSup_eq_right
#align set.Union_Union_eq_right Set.iUnion_iUnion_eq_right
theorem iInter_or {p q : Prop} (s : p ∨ q → Set α) :
⋂ h, s h = (⋂ h : p, s (Or.inl h)) ∩ ⋂ h : q, s (Or.inr h) :=
iInf_or
#align set.Inter_or Set.iInter_or
theorem iUnion_or {p q : Prop} (s : p ∨ q → Set α) :
⋃ h, s h = (⋃ i, s (Or.inl i)) ∪ ⋃ j, s (Or.inr j) :=
iSup_or
#align set.Union_or Set.iUnion_or
theorem iUnion_and {p q : Prop} (s : p ∧ q → Set α) : ⋃ h, s h = ⋃ (hp) (hq), s ⟨hp, hq⟩ :=
iSup_and
#align set.Union_and Set.iUnion_and
theorem iInter_and {p q : Prop} (s : p ∧ q → Set α) : ⋂ h, s h = ⋂ (hp) (hq), s ⟨hp, hq⟩ :=
iInf_and
#align set.Inter_and Set.iInter_and
theorem iUnion_comm (s : ι → ι' → Set α) : ⋃ (i) (i'), s i i' = ⋃ (i') (i), s i i' :=
iSup_comm
#align set.Union_comm Set.iUnion_comm
theorem iInter_comm (s : ι → ι' → Set α) : ⋂ (i) (i'), s i i' = ⋂ (i') (i), s i i' :=
iInf_comm
#align set.Inter_comm Set.iInter_comm
theorem iUnion_sigma {γ : α → Type*} (s : Sigma γ → Set β) : ⋃ ia, s ia = ⋃ i, ⋃ a, s ⟨i, a⟩ :=
iSup_sigma
theorem iUnion_sigma' {γ : α → Type*} (s : ∀ i, γ i → Set β) :
⋃ i, ⋃ a, s i a = ⋃ ia : Sigma γ, s ia.1 ia.2 :=
iSup_sigma' _
theorem iInter_sigma {γ : α → Type*} (s : Sigma γ → Set β) : ⋂ ia, s ia = ⋂ i, ⋂ a, s ⟨i, a⟩ :=
iInf_sigma
theorem iInter_sigma' {γ : α → Type*} (s : ∀ i, γ i → Set β) :
⋂ i, ⋂ a, s i a = ⋂ ia : Sigma γ, s ia.1 ia.2 :=
iInf_sigma' _
theorem iUnion₂_comm (s : ∀ i₁, κ₁ i₁ → ∀ i₂, κ₂ i₂ → Set α) :
⋃ (i₁) (j₁) (i₂) (j₂), s i₁ j₁ i₂ j₂ = ⋃ (i₂) (j₂) (i₁) (j₁), s i₁ j₁ i₂ j₂ :=
iSup₂_comm _
#align set.Union₂_comm Set.iUnion₂_comm
theorem iInter₂_comm (s : ∀ i₁, κ₁ i₁ → ∀ i₂, κ₂ i₂ → Set α) :
⋂ (i₁) (j₁) (i₂) (j₂), s i₁ j₁ i₂ j₂ = ⋂ (i₂) (j₂) (i₁) (j₁), s i₁ j₁ i₂ j₂ :=
iInf₂_comm _
#align set.Inter₂_comm Set.iInter₂_comm
@[simp]
theorem biUnion_and (p : ι → Prop) (q : ι → ι' → Prop) (s : ∀ x y, p x ∧ q x y → Set α) :
⋃ (x : ι) (y : ι') (h : p x ∧ q x y), s x y h =
⋃ (x : ι) (hx : p x) (y : ι') (hy : q x y), s x y ⟨hx, hy⟩ := by
simp only [iUnion_and, @iUnion_comm _ ι']
#align set.bUnion_and Set.biUnion_and
@[simp]
theorem biUnion_and' (p : ι' → Prop) (q : ι → ι' → Prop) (s : ∀ x y, p y ∧ q x y → Set α) :
⋃ (x : ι) (y : ι') (h : p y ∧ q x y), s x y h =
⋃ (y : ι') (hy : p y) (x : ι) (hx : q x y), s x y ⟨hy, hx⟩ := by
simp only [iUnion_and, @iUnion_comm _ ι]
#align set.bUnion_and' Set.biUnion_and'
@[simp]
theorem biInter_and (p : ι → Prop) (q : ι → ι' → Prop) (s : ∀ x y, p x ∧ q x y → Set α) :
⋂ (x : ι) (y : ι') (h : p x ∧ q x y), s x y h =
⋂ (x : ι) (hx : p x) (y : ι') (hy : q x y), s x y ⟨hx, hy⟩ := by
simp only [iInter_and, @iInter_comm _ ι']
#align set.bInter_and Set.biInter_and
@[simp]
theorem biInter_and' (p : ι' → Prop) (q : ι → ι' → Prop) (s : ∀ x y, p y ∧ q x y → Set α) :
⋂ (x : ι) (y : ι') (h : p y ∧ q x y), s x y h =
⋂ (y : ι') (hy : p y) (x : ι) (hx : q x y), s x y ⟨hy, hx⟩ := by
simp only [iInter_and, @iInter_comm _ ι]
#align set.bInter_and' Set.biInter_and'
@[simp]
theorem iUnion_iUnion_eq_or_left {b : β} {p : β → Prop} {s : ∀ x : β, x = b ∨ p x → Set α} :
⋃ (x) (h), s x h = s b (Or.inl rfl) ∪ ⋃ (x) (h : p x), s x (Or.inr h) := by
simp only [iUnion_or, iUnion_union_distrib, iUnion_iUnion_eq_left]
#align set.Union_Union_eq_or_left Set.iUnion_iUnion_eq_or_left
@[simp]
theorem iInter_iInter_eq_or_left {b : β} {p : β → Prop} {s : ∀ x : β, x = b ∨ p x → Set α} :
⋂ (x) (h), s x h = s b (Or.inl rfl) ∩ ⋂ (x) (h : p x), s x (Or.inr h) := by
simp only [iInter_or, iInter_inter_distrib, iInter_iInter_eq_left]
#align set.Inter_Inter_eq_or_left Set.iInter_iInter_eq_or_left
theorem mem_biUnion {s : Set α} {t : α → Set β} {x : α} {y : β} (xs : x ∈ s) (ytx : y ∈ t x) :
y ∈ ⋃ x ∈ s, t x :=
mem_iUnion₂_of_mem xs ytx
#align set.mem_bUnion Set.mem_biUnion
theorem mem_biInter {s : Set α} {t : α → Set β} {y : β} (h : ∀ x ∈ s, y ∈ t x) :
y ∈ ⋂ x ∈ s, t x :=
mem_iInter₂_of_mem h
#align set.mem_bInter Set.mem_biInter
theorem subset_biUnion_of_mem {s : Set α} {u : α → Set β} {x : α} (xs : x ∈ s) :
u x ⊆ ⋃ x ∈ s, u x :=
-- Porting note: Why is this not just `subset_iUnion₂ x xs`?
@subset_iUnion₂ β α (· ∈ s) (fun i _ => u i) x xs
#align set.subset_bUnion_of_mem Set.subset_biUnion_of_mem
theorem biInter_subset_of_mem {s : Set α} {t : α → Set β} {x : α} (xs : x ∈ s) :
⋂ x ∈ s, t x ⊆ t x :=
iInter₂_subset x xs
#align set.bInter_subset_of_mem Set.biInter_subset_of_mem
theorem biUnion_subset_biUnion_left {s s' : Set α} {t : α → Set β} (h : s ⊆ s') :
⋃ x ∈ s, t x ⊆ ⋃ x ∈ s', t x :=
iUnion₂_subset fun _ hx => subset_biUnion_of_mem <| h hx
#align set.bUnion_subset_bUnion_left Set.biUnion_subset_biUnion_left
theorem biInter_subset_biInter_left {s s' : Set α} {t : α → Set β} (h : s' ⊆ s) :
⋂ x ∈ s, t x ⊆ ⋂ x ∈ s', t x :=
subset_iInter₂ fun _ hx => biInter_subset_of_mem <| h hx
#align set.bInter_subset_bInter_left Set.biInter_subset_biInter_left
theorem biUnion_mono {s s' : Set α} {t t' : α → Set β} (hs : s' ⊆ s) (h : ∀ x ∈ s, t x ⊆ t' x) :
⋃ x ∈ s', t x ⊆ ⋃ x ∈ s, t' x :=
(biUnion_subset_biUnion_left hs).trans <| iUnion₂_mono h
#align set.bUnion_mono Set.biUnion_mono
theorem biInter_mono {s s' : Set α} {t t' : α → Set β} (hs : s ⊆ s') (h : ∀ x ∈ s, t x ⊆ t' x) :
⋂ x ∈ s', t x ⊆ ⋂ x ∈ s, t' x :=
(biInter_subset_biInter_left hs).trans <| iInter₂_mono h
#align set.bInter_mono Set.biInter_mono
theorem biUnion_eq_iUnion (s : Set α) (t : ∀ x ∈ s, Set β) :
⋃ x ∈ s, t x ‹_› = ⋃ x : s, t x x.2 :=
iSup_subtype'
#align set.bUnion_eq_Union Set.biUnion_eq_iUnion
theorem biInter_eq_iInter (s : Set α) (t : ∀ x ∈ s, Set β) :
⋂ x ∈ s, t x ‹_› = ⋂ x : s, t x x.2 :=
iInf_subtype'
#align set.bInter_eq_Inter Set.biInter_eq_iInter
theorem iUnion_subtype (p : α → Prop) (s : { x // p x } → Set β) :
⋃ x : { x // p x }, s x = ⋃ (x) (hx : p x), s ⟨x, hx⟩ :=
iSup_subtype
#align set.Union_subtype Set.iUnion_subtype
theorem iInter_subtype (p : α → Prop) (s : { x // p x } → Set β) :
⋂ x : { x // p x }, s x = ⋂ (x) (hx : p x), s ⟨x, hx⟩ :=
iInf_subtype
#align set.Inter_subtype Set.iInter_subtype
theorem biInter_empty (u : α → Set β) : ⋂ x ∈ (∅ : Set α), u x = univ :=
iInf_emptyset
#align set.bInter_empty Set.biInter_empty
theorem biInter_univ (u : α → Set β) : ⋂ x ∈ @univ α, u x = ⋂ x, u x :=
iInf_univ
#align set.bInter_univ Set.biInter_univ
@[simp]
theorem biUnion_self (s : Set α) : ⋃ x ∈ s, s = s :=
Subset.antisymm (iUnion₂_subset fun _ _ => Subset.refl s) fun _ hx => mem_biUnion hx hx
#align set.bUnion_self Set.biUnion_self
@[simp]
theorem iUnion_nonempty_self (s : Set α) : ⋃ _ : s.Nonempty, s = s := by
rw [iUnion_nonempty_index, biUnion_self]
#align set.Union_nonempty_self Set.iUnion_nonempty_self
theorem biInter_singleton (a : α) (s : α → Set β) : ⋂ x ∈ ({a} : Set α), s x = s a :=
iInf_singleton
#align set.bInter_singleton Set.biInter_singleton
theorem biInter_union (s t : Set α) (u : α → Set β) :
⋂ x ∈ s ∪ t, u x = (⋂ x ∈ s, u x) ∩ ⋂ x ∈ t, u x :=
iInf_union
#align set.bInter_union Set.biInter_union
theorem biInter_insert (a : α) (s : Set α) (t : α → Set β) :
⋂ x ∈ insert a s, t x = t a ∩ ⋂ x ∈ s, t x := by simp
#align set.bInter_insert Set.biInter_insert
theorem biInter_pair (a b : α) (s : α → Set β) : ⋂ x ∈ ({a, b} : Set α), s x = s a ∩ s b := by
rw [biInter_insert, biInter_singleton]
#align set.bInter_pair Set.biInter_pair
theorem biInter_inter {ι α : Type*} {s : Set ι} (hs : s.Nonempty) (f : ι → Set α) (t : Set α) :
⋂ i ∈ s, f i ∩ t = (⋂ i ∈ s, f i) ∩ t := by
haveI : Nonempty s := hs.to_subtype
simp [biInter_eq_iInter, ← iInter_inter]
#align set.bInter_inter Set.biInter_inter
theorem inter_biInter {ι α : Type*} {s : Set ι} (hs : s.Nonempty) (f : ι → Set α) (t : Set α) :
⋂ i ∈ s, t ∩ f i = t ∩ ⋂ i ∈ s, f i := by
rw [inter_comm, ← biInter_inter hs]
simp [inter_comm]
#align set.inter_bInter Set.inter_biInter
theorem biUnion_empty (s : α → Set β) : ⋃ x ∈ (∅ : Set α), s x = ∅ :=
iSup_emptyset
#align set.bUnion_empty Set.biUnion_empty
theorem biUnion_univ (s : α → Set β) : ⋃ x ∈ @univ α, s x = ⋃ x, s x :=
iSup_univ
#align set.bUnion_univ Set.biUnion_univ
theorem biUnion_singleton (a : α) (s : α → Set β) : ⋃ x ∈ ({a} : Set α), s x = s a :=
iSup_singleton
#align set.bUnion_singleton Set.biUnion_singleton
@[simp]
theorem biUnion_of_singleton (s : Set α) : ⋃ x ∈ s, {x} = s :=
ext <| by simp
#align set.bUnion_of_singleton Set.biUnion_of_singleton
theorem biUnion_union (s t : Set α) (u : α → Set β) :
⋃ x ∈ s ∪ t, u x = (⋃ x ∈ s, u x) ∪ ⋃ x ∈ t, u x :=
iSup_union
#align set.bUnion_union Set.biUnion_union
@[simp]
theorem iUnion_coe_set {α β : Type*} (s : Set α) (f : s → Set β) :
⋃ i, f i = ⋃ i ∈ s, f ⟨i, ‹i ∈ s›⟩ :=
iUnion_subtype _ _
#align set.Union_coe_set Set.iUnion_coe_set
@[simp]
theorem iInter_coe_set {α β : Type*} (s : Set α) (f : s → Set β) :
⋂ i, f i = ⋂ i ∈ s, f ⟨i, ‹i ∈ s›⟩ :=
iInter_subtype _ _
#align set.Inter_coe_set Set.iInter_coe_set
theorem biUnion_insert (a : α) (s : Set α) (t : α → Set β) :
⋃ x ∈ insert a s, t x = t a ∪ ⋃ x ∈ s, t x := by simp
#align set.bUnion_insert Set.biUnion_insert
theorem biUnion_pair (a b : α) (s : α → Set β) : ⋃ x ∈ ({a, b} : Set α), s x = s a ∪ s b := by
simp
#align set.bUnion_pair Set.biUnion_pair
theorem inter_iUnion₂ (s : Set α) (t : ∀ i, κ i → Set α) :
(s ∩ ⋃ (i) (j), t i j) = ⋃ (i) (j), s ∩ t i j := by simp only [inter_iUnion]
#align set.inter_Union₂ Set.inter_iUnion₂
theorem iUnion₂_inter (s : ∀ i, κ i → Set α) (t : Set α) :
(⋃ (i) (j), s i j) ∩ t = ⋃ (i) (j), s i j ∩ t := by simp_rw [iUnion_inter]
#align set.Union₂_inter Set.iUnion₂_inter
theorem union_iInter₂ (s : Set α) (t : ∀ i, κ i → Set α) :
(s ∪ ⋂ (i) (j), t i j) = ⋂ (i) (j), s ∪ t i j := by simp_rw [union_iInter]
#align set.union_Inter₂ Set.union_iInter₂
theorem iInter₂_union (s : ∀ i, κ i → Set α) (t : Set α) :
(⋂ (i) (j), s i j) ∪ t = ⋂ (i) (j), s i j ∪ t := by simp_rw [iInter_union]
#align set.Inter₂_union Set.iInter₂_union
theorem mem_sUnion_of_mem {x : α} {t : Set α} {S : Set (Set α)} (hx : x ∈ t) (ht : t ∈ S) :
x ∈ ⋃₀S :=
⟨t, ht, hx⟩
#align set.mem_sUnion_of_mem Set.mem_sUnion_of_mem
-- is this theorem really necessary?
theorem not_mem_of_not_mem_sUnion {x : α} {t : Set α} {S : Set (Set α)} (hx : x ∉ ⋃₀S)
(ht : t ∈ S) : x ∉ t := fun h => hx ⟨t, ht, h⟩
#align set.not_mem_of_not_mem_sUnion Set.not_mem_of_not_mem_sUnion
theorem sInter_subset_of_mem {S : Set (Set α)} {t : Set α} (tS : t ∈ S) : ⋂₀ S ⊆ t :=
sInf_le tS
#align set.sInter_subset_of_mem Set.sInter_subset_of_mem
theorem subset_sUnion_of_mem {S : Set (Set α)} {t : Set α} (tS : t ∈ S) : t ⊆ ⋃₀S :=
le_sSup tS
#align set.subset_sUnion_of_mem Set.subset_sUnion_of_mem
theorem subset_sUnion_of_subset {s : Set α} (t : Set (Set α)) (u : Set α) (h₁ : s ⊆ u)
(h₂ : u ∈ t) : s ⊆ ⋃₀t :=
Subset.trans h₁ (subset_sUnion_of_mem h₂)
#align set.subset_sUnion_of_subset Set.subset_sUnion_of_subset
theorem sUnion_subset {S : Set (Set α)} {t : Set α} (h : ∀ t' ∈ S, t' ⊆ t) : ⋃₀S ⊆ t :=
sSup_le h
#align set.sUnion_subset Set.sUnion_subset
@[simp]
theorem sUnion_subset_iff {s : Set (Set α)} {t : Set α} : ⋃₀s ⊆ t ↔ ∀ t' ∈ s, t' ⊆ t :=
sSup_le_iff
#align set.sUnion_subset_iff Set.sUnion_subset_iff
lemma sUnion_mono_subsets {s : Set (Set α)} {f : Set α → Set α} (hf : ∀ t : Set α, t ⊆ f t) :
⋃₀ s ⊆ ⋃₀ (f '' s) :=
fun _ ⟨t, htx, hxt⟩ ↦ ⟨f t, mem_image_of_mem f htx, hf t hxt⟩
lemma sUnion_mono_supsets {s : Set (Set α)} {f : Set α → Set α} (hf : ∀ t : Set α, f t ⊆ t) :
⋃₀ (f '' s) ⊆ ⋃₀ s :=
-- If t ∈ f '' s is arbitrary; t = f u for some u : Set α.
fun _ ⟨_, ⟨u, hus, hut⟩, hxt⟩ ↦ ⟨u, hus, (hut ▸ hf u) hxt⟩
theorem subset_sInter {S : Set (Set α)} {t : Set α} (h : ∀ t' ∈ S, t ⊆ t') : t ⊆ ⋂₀ S :=
le_sInf h
#align set.subset_sInter Set.subset_sInter
@[simp]
theorem subset_sInter_iff {S : Set (Set α)} {t : Set α} : t ⊆ ⋂₀ S ↔ ∀ t' ∈ S, t ⊆ t' :=
le_sInf_iff
#align set.subset_sInter_iff Set.subset_sInter_iff
@[gcongr]
theorem sUnion_subset_sUnion {S T : Set (Set α)} (h : S ⊆ T) : ⋃₀S ⊆ ⋃₀T :=
sUnion_subset fun _ hs => subset_sUnion_of_mem (h hs)
#align set.sUnion_subset_sUnion Set.sUnion_subset_sUnion
@[gcongr]
theorem sInter_subset_sInter {S T : Set (Set α)} (h : S ⊆ T) : ⋂₀ T ⊆ ⋂₀ S :=
subset_sInter fun _ hs => sInter_subset_of_mem (h hs)
#align set.sInter_subset_sInter Set.sInter_subset_sInter
@[simp]
theorem sUnion_empty : ⋃₀∅ = (∅ : Set α) :=
sSup_empty
#align set.sUnion_empty Set.sUnion_empty
@[simp]
theorem sInter_empty : ⋂₀ ∅ = (univ : Set α) :=
sInf_empty
#align set.sInter_empty Set.sInter_empty
@[simp]
theorem sUnion_singleton (s : Set α) : ⋃₀{s} = s :=
sSup_singleton
#align set.sUnion_singleton Set.sUnion_singleton
@[simp]
theorem sInter_singleton (s : Set α) : ⋂₀ {s} = s :=
sInf_singleton
#align set.sInter_singleton Set.sInter_singleton
@[simp]
theorem sUnion_eq_empty {S : Set (Set α)} : ⋃₀S = ∅ ↔ ∀ s ∈ S, s = ∅ :=
sSup_eq_bot
#align set.sUnion_eq_empty Set.sUnion_eq_empty
@[simp]
theorem sInter_eq_univ {S : Set (Set α)} : ⋂₀ S = univ ↔ ∀ s ∈ S, s = univ :=
sInf_eq_top
#align set.sInter_eq_univ Set.sInter_eq_univ
theorem subset_powerset_iff {s : Set (Set α)} {t : Set α} : s ⊆ 𝒫 t ↔ ⋃₀ s ⊆ t :=
sUnion_subset_iff.symm
theorem sUnion_powerset_gc :
GaloisConnection (⋃₀ · : Set (Set α) → Set α) (𝒫 · : Set α → Set (Set α)) :=
gc_sSup_Iic
def sUnion_powerset_gi :
GaloisInsertion (⋃₀ · : Set (Set α) → Set α) (𝒫 · : Set α → Set (Set α)) :=
gi_sSup_Iic
theorem sUnion_mem_empty_univ {S : Set (Set α)} (h : S ⊆ {∅, univ}) :
⋃₀ S ∈ ({∅, univ} : Set (Set α)) := by
simp only [mem_insert_iff, mem_singleton_iff, or_iff_not_imp_left, sUnion_eq_empty, not_forall]
rintro ⟨s, hs, hne⟩
obtain rfl : s = univ := (h hs).resolve_left hne
exact univ_subset_iff.1 <| subset_sUnion_of_mem hs
@[simp]
theorem nonempty_sUnion {S : Set (Set α)} : (⋃₀S).Nonempty ↔ ∃ s ∈ S, Set.Nonempty s := by
simp [nonempty_iff_ne_empty]
#align set.nonempty_sUnion Set.nonempty_sUnion
theorem Nonempty.of_sUnion {s : Set (Set α)} (h : (⋃₀s).Nonempty) : s.Nonempty :=
let ⟨s, hs, _⟩ := nonempty_sUnion.1 h
⟨s, hs⟩
#align set.nonempty.of_sUnion Set.Nonempty.of_sUnion
theorem Nonempty.of_sUnion_eq_univ [Nonempty α] {s : Set (Set α)} (h : ⋃₀s = univ) : s.Nonempty :=
Nonempty.of_sUnion <| h.symm ▸ univ_nonempty
#align set.nonempty.of_sUnion_eq_univ Set.Nonempty.of_sUnion_eq_univ
theorem sUnion_union (S T : Set (Set α)) : ⋃₀(S ∪ T) = ⋃₀S ∪ ⋃₀T :=
sSup_union
#align set.sUnion_union Set.sUnion_union
theorem sInter_union (S T : Set (Set α)) : ⋂₀ (S ∪ T) = ⋂₀ S ∩ ⋂₀ T :=
sInf_union
#align set.sInter_union Set.sInter_union
@[simp]
theorem sUnion_insert (s : Set α) (T : Set (Set α)) : ⋃₀insert s T = s ∪ ⋃₀T :=
sSup_insert
#align set.sUnion_insert Set.sUnion_insert
@[simp]
theorem sInter_insert (s : Set α) (T : Set (Set α)) : ⋂₀ insert s T = s ∩ ⋂₀ T :=
sInf_insert
#align set.sInter_insert Set.sInter_insert
@[simp]
theorem sUnion_diff_singleton_empty (s : Set (Set α)) : ⋃₀(s \ {∅}) = ⋃₀s :=
sSup_diff_singleton_bot s
#align set.sUnion_diff_singleton_empty Set.sUnion_diff_singleton_empty
@[simp]
theorem sInter_diff_singleton_univ (s : Set (Set α)) : ⋂₀ (s \ {univ}) = ⋂₀ s :=
sInf_diff_singleton_top s
#align set.sInter_diff_singleton_univ Set.sInter_diff_singleton_univ
theorem sUnion_pair (s t : Set α) : ⋃₀{s, t} = s ∪ t :=
sSup_pair
#align set.sUnion_pair Set.sUnion_pair
theorem sInter_pair (s t : Set α) : ⋂₀ {s, t} = s ∩ t :=
sInf_pair
#align set.sInter_pair Set.sInter_pair
@[simp]
theorem sUnion_image (f : α → Set β) (s : Set α) : ⋃₀(f '' s) = ⋃ x ∈ s, f x :=
sSup_image
#align set.sUnion_image Set.sUnion_image
@[simp]
theorem sInter_image (f : α → Set β) (s : Set α) : ⋂₀ (f '' s) = ⋂ x ∈ s, f x :=
sInf_image
#align set.sInter_image Set.sInter_image
@[simp]
theorem sUnion_range (f : ι → Set β) : ⋃₀range f = ⋃ x, f x :=
rfl
#align set.sUnion_range Set.sUnion_range
@[simp]
theorem sInter_range (f : ι → Set β) : ⋂₀ range f = ⋂ x, f x :=
rfl
#align set.sInter_range Set.sInter_range
theorem iUnion_eq_univ_iff {f : ι → Set α} : ⋃ i, f i = univ ↔ ∀ x, ∃ i, x ∈ f i := by
simp only [eq_univ_iff_forall, mem_iUnion]
#align set.Union_eq_univ_iff Set.iUnion_eq_univ_iff
theorem iUnion₂_eq_univ_iff {s : ∀ i, κ i → Set α} :
⋃ (i) (j), s i j = univ ↔ ∀ a, ∃ i j, a ∈ s i j := by
simp only [iUnion_eq_univ_iff, mem_iUnion]
#align set.Union₂_eq_univ_iff Set.iUnion₂_eq_univ_iff
theorem sUnion_eq_univ_iff {c : Set (Set α)} : ⋃₀c = univ ↔ ∀ a, ∃ b ∈ c, a ∈ b := by
simp only [eq_univ_iff_forall, mem_sUnion]
#align set.sUnion_eq_univ_iff Set.sUnion_eq_univ_iff
-- classical
theorem iInter_eq_empty_iff {f : ι → Set α} : ⋂ i, f i = ∅ ↔ ∀ x, ∃ i, x ∉ f i := by
simp [Set.eq_empty_iff_forall_not_mem]
#align set.Inter_eq_empty_iff Set.iInter_eq_empty_iff
-- classical
theorem iInter₂_eq_empty_iff {s : ∀ i, κ i → Set α} :
⋂ (i) (j), s i j = ∅ ↔ ∀ a, ∃ i j, a ∉ s i j := by
simp only [eq_empty_iff_forall_not_mem, mem_iInter, not_forall]
#align set.Inter₂_eq_empty_iff Set.iInter₂_eq_empty_iff
-- classical
theorem sInter_eq_empty_iff {c : Set (Set α)} : ⋂₀ c = ∅ ↔ ∀ a, ∃ b ∈ c, a ∉ b := by
simp [Set.eq_empty_iff_forall_not_mem]
#align set.sInter_eq_empty_iff Set.sInter_eq_empty_iff
-- classical
@[simp]
theorem nonempty_iInter {f : ι → Set α} : (⋂ i, f i).Nonempty ↔ ∃ x, ∀ i, x ∈ f i := by
simp [nonempty_iff_ne_empty, iInter_eq_empty_iff]
#align set.nonempty_Inter Set.nonempty_iInter
-- classical
-- Porting note (#10618): removing `simp`. `simp` can prove it
theorem nonempty_iInter₂ {s : ∀ i, κ i → Set α} :
(⋂ (i) (j), s i j).Nonempty ↔ ∃ a, ∀ i j, a ∈ s i j := by
simp
#align set.nonempty_Inter₂ Set.nonempty_iInter₂
-- classical
@[simp]
theorem nonempty_sInter {c : Set (Set α)} : (⋂₀ c).Nonempty ↔ ∃ a, ∀ b ∈ c, a ∈ b := by
simp [nonempty_iff_ne_empty, sInter_eq_empty_iff]
#align set.nonempty_sInter Set.nonempty_sInter
-- classical
theorem compl_sUnion (S : Set (Set α)) : (⋃₀S)ᶜ = ⋂₀ (compl '' S) :=
ext fun x => by simp
#align set.compl_sUnion Set.compl_sUnion
-- classical
theorem sUnion_eq_compl_sInter_compl (S : Set (Set α)) : ⋃₀S = (⋂₀ (compl '' S))ᶜ := by
rw [← compl_compl (⋃₀S), compl_sUnion]
#align set.sUnion_eq_compl_sInter_compl Set.sUnion_eq_compl_sInter_compl
-- classical
theorem compl_sInter (S : Set (Set α)) : (⋂₀ S)ᶜ = ⋃₀(compl '' S) := by
rw [sUnion_eq_compl_sInter_compl, compl_compl_image]
#align set.compl_sInter Set.compl_sInter
-- classical
theorem sInter_eq_compl_sUnion_compl (S : Set (Set α)) : ⋂₀ S = (⋃₀(compl '' S))ᶜ := by
rw [← compl_compl (⋂₀ S), compl_sInter]
#align set.sInter_eq_compl_sUnion_compl Set.sInter_eq_compl_sUnion_compl
theorem inter_empty_of_inter_sUnion_empty {s t : Set α} {S : Set (Set α)} (hs : t ∈ S)
(h : s ∩ ⋃₀S = ∅) : s ∩ t = ∅ :=
eq_empty_of_subset_empty <| by
rw [← h]; exact inter_subset_inter_right _ (subset_sUnion_of_mem hs)
#align set.inter_empty_of_inter_sUnion_empty Set.inter_empty_of_inter_sUnion_empty
theorem range_sigma_eq_iUnion_range {γ : α → Type*} (f : Sigma γ → β) :
range f = ⋃ a, range fun b => f ⟨a, b⟩ :=
Set.ext <| by simp
#align set.range_sigma_eq_Union_range Set.range_sigma_eq_iUnion_range
theorem iUnion_eq_range_sigma (s : α → Set β) : ⋃ i, s i = range fun a : Σi, s i => a.2 := by
simp [Set.ext_iff]
#align set.Union_eq_range_sigma Set.iUnion_eq_range_sigma
theorem iUnion_eq_range_psigma (s : ι → Set β) : ⋃ i, s i = range fun a : Σ'i, s i => a.2 := by
simp [Set.ext_iff]
#align set.Union_eq_range_psigma Set.iUnion_eq_range_psigma
theorem iUnion_image_preimage_sigma_mk_eq_self {ι : Type*} {σ : ι → Type*} (s : Set (Sigma σ)) :
⋃ i, Sigma.mk i '' (Sigma.mk i ⁻¹' s) = s := by
ext x
simp only [mem_iUnion, mem_image, mem_preimage]
constructor
· rintro ⟨i, a, h, rfl⟩
exact h
· intro h
cases' x with i a
exact ⟨i, a, h, rfl⟩
#align set.Union_image_preimage_sigma_mk_eq_self Set.iUnion_image_preimage_sigma_mk_eq_self
theorem Sigma.univ (X : α → Type*) : (Set.univ : Set (Σa, X a)) = ⋃ a, range (Sigma.mk a) :=
Set.ext fun x =>
iff_of_true trivial ⟨range (Sigma.mk x.1), Set.mem_range_self _, x.2, Sigma.eta x⟩
#align set.sigma.univ Set.Sigma.univ
alias sUnion_mono := sUnion_subset_sUnion
#align set.sUnion_mono Set.sUnion_mono
theorem iUnion_subset_iUnion_const {s : Set α} (h : ι → ι₂) : ⋃ _ : ι, s ⊆ ⋃ _ : ι₂, s :=
iSup_const_mono (α := Set α) h
#align set.Union_subset_Union_const Set.iUnion_subset_iUnion_const
@[simp]
theorem iUnion_singleton_eq_range {α β : Type*} (f : α → β) : ⋃ x : α, {f x} = range f := by
ext x
simp [@eq_comm _ x]
#align set.Union_singleton_eq_range Set.iUnion_singleton_eq_range
theorem iUnion_of_singleton (α : Type*) : (⋃ x, {x} : Set α) = univ := by simp [Set.ext_iff]
#align set.Union_of_singleton Set.iUnion_of_singleton
theorem iUnion_of_singleton_coe (s : Set α) : ⋃ i : s, ({(i : α)} : Set α) = s := by simp
#align set.Union_of_singleton_coe Set.iUnion_of_singleton_coe
theorem sUnion_eq_biUnion {s : Set (Set α)} : ⋃₀s = ⋃ (i : Set α) (_ : i ∈ s), i := by
rw [← sUnion_image, image_id']
#align set.sUnion_eq_bUnion Set.sUnion_eq_biUnion
theorem sInter_eq_biInter {s : Set (Set α)} : ⋂₀ s = ⋂ (i : Set α) (_ : i ∈ s), i := by
rw [← sInter_image, image_id']
#align set.sInter_eq_bInter Set.sInter_eq_biInter
theorem sUnion_eq_iUnion {s : Set (Set α)} : ⋃₀s = ⋃ i : s, i := by
simp only [← sUnion_range, Subtype.range_coe]
#align set.sUnion_eq_Union Set.sUnion_eq_iUnion
theorem sInter_eq_iInter {s : Set (Set α)} : ⋂₀ s = ⋂ i : s, i := by
simp only [← sInter_range, Subtype.range_coe]
#align set.sInter_eq_Inter Set.sInter_eq_iInter
@[simp]
theorem iUnion_of_empty [IsEmpty ι] (s : ι → Set α) : ⋃ i, s i = ∅ :=
iSup_of_empty _
#align set.Union_of_empty Set.iUnion_of_empty
@[simp]
theorem iInter_of_empty [IsEmpty ι] (s : ι → Set α) : ⋂ i, s i = univ :=
iInf_of_empty _
#align set.Inter_of_empty Set.iInter_of_empty
theorem union_eq_iUnion {s₁ s₂ : Set α} : s₁ ∪ s₂ = ⋃ b : Bool, cond b s₁ s₂ :=
sup_eq_iSup s₁ s₂
#align set.union_eq_Union Set.union_eq_iUnion
theorem inter_eq_iInter {s₁ s₂ : Set α} : s₁ ∩ s₂ = ⋂ b : Bool, cond b s₁ s₂ :=
inf_eq_iInf s₁ s₂
#align set.inter_eq_Inter Set.inter_eq_iInter
theorem sInter_union_sInter {S T : Set (Set α)} :
⋂₀ S ∪ ⋂₀ T = ⋂ p ∈ S ×ˢ T, (p : Set α × Set α).1 ∪ p.2 :=
sInf_sup_sInf
#align set.sInter_union_sInter Set.sInter_union_sInter
theorem sUnion_inter_sUnion {s t : Set (Set α)} :
⋃₀s ∩ ⋃₀t = ⋃ p ∈ s ×ˢ t, (p : Set α × Set α).1 ∩ p.2 :=
sSup_inf_sSup
#align set.sUnion_inter_sUnion Set.sUnion_inter_sUnion
theorem biUnion_iUnion (s : ι → Set α) (t : α → Set β) :
⋃ x ∈ ⋃ i, s i, t x = ⋃ (i) (x ∈ s i), t x := by simp [@iUnion_comm _ ι]
#align set.bUnion_Union Set.biUnion_iUnion
theorem biInter_iUnion (s : ι → Set α) (t : α → Set β) :
⋂ x ∈ ⋃ i, s i, t x = ⋂ (i) (x ∈ s i), t x := by simp [@iInter_comm _ ι]
#align set.bInter_Union Set.biInter_iUnion
theorem sUnion_iUnion (s : ι → Set (Set α)) : ⋃₀⋃ i, s i = ⋃ i, ⋃₀s i := by
simp only [sUnion_eq_biUnion, biUnion_iUnion]
#align set.sUnion_Union Set.sUnion_iUnion
theorem sInter_iUnion (s : ι → Set (Set α)) : ⋂₀ ⋃ i, s i = ⋂ i, ⋂₀ s i := by
simp only [sInter_eq_biInter, biInter_iUnion]
#align set.sInter_Union Set.sInter_iUnion
theorem iUnion_range_eq_sUnion {α β : Type*} (C : Set (Set α)) {f : ∀ s : C, β → (s : Type _)}
(hf : ∀ s : C, Surjective (f s)) : ⋃ y : β, range (fun s : C => (f s y).val) = ⋃₀C := by
ext x; constructor
· rintro ⟨s, ⟨y, rfl⟩, ⟨s, hs⟩, rfl⟩
refine ⟨_, hs, ?_⟩
exact (f ⟨s, hs⟩ y).2
· rintro ⟨s, hs, hx⟩
cases' hf ⟨s, hs⟩ ⟨x, hx⟩ with y hy
refine ⟨_, ⟨y, rfl⟩, ⟨s, hs⟩, ?_⟩
exact congr_arg Subtype.val hy
#align set.Union_range_eq_sUnion Set.iUnion_range_eq_sUnion
theorem iUnion_range_eq_iUnion (C : ι → Set α) {f : ∀ x : ι, β → C x}
(hf : ∀ x : ι, Surjective (f x)) : ⋃ y : β, range (fun x : ι => (f x y).val) = ⋃ x, C x := by
ext x; rw [mem_iUnion, mem_iUnion]; constructor
· rintro ⟨y, i, rfl⟩
exact ⟨i, (f i y).2⟩
· rintro ⟨i, hx⟩
cases' hf i ⟨x, hx⟩ with y hy
exact ⟨y, i, congr_arg Subtype.val hy⟩
#align set.Union_range_eq_Union Set.iUnion_range_eq_iUnion
theorem union_distrib_iInter_left (s : ι → Set α) (t : Set α) : (t ∪ ⋂ i, s i) = ⋂ i, t ∪ s i :=
sup_iInf_eq _ _
#align set.union_distrib_Inter_left Set.union_distrib_iInter_left
theorem union_distrib_iInter₂_left (s : Set α) (t : ∀ i, κ i → Set α) :
(s ∪ ⋂ (i) (j), t i j) = ⋂ (i) (j), s ∪ t i j := by simp_rw [union_distrib_iInter_left]
#align set.union_distrib_Inter₂_left Set.union_distrib_iInter₂_left
theorem union_distrib_iInter_right (s : ι → Set α) (t : Set α) : (⋂ i, s i) ∪ t = ⋂ i, s i ∪ t :=
iInf_sup_eq _ _
#align set.union_distrib_Inter_right Set.union_distrib_iInter_right
theorem union_distrib_iInter₂_right (s : ∀ i, κ i → Set α) (t : Set α) :
(⋂ (i) (j), s i j) ∪ t = ⋂ (i) (j), s i j ∪ t := by simp_rw [union_distrib_iInter_right]
#align set.union_distrib_Inter₂_right Set.union_distrib_iInter₂_right
section Pi
variable {π : α → Type*}
| Mathlib/Data/Set/Lattice.lean | 1,982 | 1,984 | theorem pi_def (i : Set α) (s : ∀ a, Set (π a)) : pi i s = ⋂ a ∈ i, eval a ⁻¹' s a := by |
ext
simp
|
import Mathlib.Geometry.Euclidean.Circumcenter
#align_import geometry.euclidean.monge_point from "leanprover-community/mathlib"@"1a4df69ca1a9a0e5e26bfe12e2b92814216016d0"
noncomputable section
open scoped Classical
open scoped RealInnerProductSpace
namespace Affine
namespace Simplex
open Finset AffineSubspace EuclideanGeometry PointsWithCircumcenterIndex
variable {V : Type*} {P : Type*} [NormedAddCommGroup V] [InnerProductSpace ℝ V] [MetricSpace P]
[NormedAddTorsor V P]
def mongePoint {n : ℕ} (s : Simplex ℝ P n) : P :=
(((n + 1 : ℕ) : ℝ) / ((n - 1 : ℕ) : ℝ)) •
((univ : Finset (Fin (n + 1))).centroid ℝ s.points -ᵥ s.circumcenter) +ᵥ
s.circumcenter
#align affine.simplex.monge_point Affine.Simplex.mongePoint
theorem mongePoint_eq_smul_vsub_vadd_circumcenter {n : ℕ} (s : Simplex ℝ P n) :
s.mongePoint =
(((n + 1 : ℕ) : ℝ) / ((n - 1 : ℕ) : ℝ)) •
((univ : Finset (Fin (n + 1))).centroid ℝ s.points -ᵥ s.circumcenter) +ᵥ
s.circumcenter :=
rfl
#align affine.simplex.monge_point_eq_smul_vsub_vadd_circumcenter Affine.Simplex.mongePoint_eq_smul_vsub_vadd_circumcenter
theorem mongePoint_mem_affineSpan {n : ℕ} (s : Simplex ℝ P n) :
s.mongePoint ∈ affineSpan ℝ (Set.range s.points) :=
smul_vsub_vadd_mem _ _ (centroid_mem_affineSpan_of_card_eq_add_one ℝ _ (card_fin (n + 1)))
s.circumcenter_mem_affineSpan s.circumcenter_mem_affineSpan
#align affine.simplex.monge_point_mem_affine_span Affine.Simplex.mongePoint_mem_affineSpan
theorem mongePoint_eq_of_range_eq {n : ℕ} {s₁ s₂ : Simplex ℝ P n}
(h : Set.range s₁.points = Set.range s₂.points) : s₁.mongePoint = s₂.mongePoint := by
simp_rw [mongePoint_eq_smul_vsub_vadd_circumcenter, centroid_eq_of_range_eq h,
circumcenter_eq_of_range_eq h]
#align affine.simplex.monge_point_eq_of_range_eq Affine.Simplex.mongePoint_eq_of_range_eq
def mongePointWeightsWithCircumcenter (n : ℕ) : PointsWithCircumcenterIndex (n + 2) → ℝ
| pointIndex _ => ((n + 1 : ℕ) : ℝ)⁻¹
| circumcenterIndex => -2 / ((n + 1 : ℕ) : ℝ)
#align affine.simplex.monge_point_weights_with_circumcenter Affine.Simplex.mongePointWeightsWithCircumcenter
@[simp]
theorem sum_mongePointWeightsWithCircumcenter (n : ℕ) :
∑ i, mongePointWeightsWithCircumcenter n i = 1 := by
simp_rw [sum_pointsWithCircumcenter, mongePointWeightsWithCircumcenter, sum_const, card_fin,
nsmul_eq_mul]
-- Porting note: replaced
-- have hn1 : (n + 1 : ℝ) ≠ 0 := mod_cast Nat.succ_ne_zero _
field_simp [n.cast_add_one_ne_zero]
ring
#align affine.simplex.sum_monge_point_weights_with_circumcenter Affine.Simplex.sum_mongePointWeightsWithCircumcenter
theorem mongePoint_eq_affineCombination_of_pointsWithCircumcenter {n : ℕ}
(s : Simplex ℝ P (n + 2)) :
s.mongePoint =
(univ : Finset (PointsWithCircumcenterIndex (n + 2))).affineCombination ℝ
s.pointsWithCircumcenter (mongePointWeightsWithCircumcenter n) := by
rw [mongePoint_eq_smul_vsub_vadd_circumcenter,
centroid_eq_affineCombination_of_pointsWithCircumcenter,
circumcenter_eq_affineCombination_of_pointsWithCircumcenter, affineCombination_vsub,
← LinearMap.map_smul, weightedVSub_vadd_affineCombination]
congr with i
rw [Pi.add_apply, Pi.smul_apply, smul_eq_mul, Pi.sub_apply]
-- Porting note: replaced
-- have hn1 : (n + 1 : ℝ) ≠ 0 := mod_cast Nat.succ_ne_zero _
have hn1 : (n + 1 : ℝ) ≠ 0 := n.cast_add_one_ne_zero
cases i <;>
simp_rw [centroidWeightsWithCircumcenter, circumcenterWeightsWithCircumcenter,
mongePointWeightsWithCircumcenter] <;>
rw [add_tsub_assoc_of_le (by decide : 1 ≤ 2), (by decide : 2 - 1 = 1)]
· rw [if_pos (mem_univ _), sub_zero, add_zero, card_fin]
-- Porting note: replaced
-- have hn3 : (n + 2 + 1 : ℝ) ≠ 0 := mod_cast Nat.succ_ne_zero _
have hn3 : (n + 2 + 1 : ℝ) ≠ 0 := by norm_cast
field_simp [hn1, hn3, mul_comm]
· field_simp [hn1]
ring
#align affine.simplex.monge_point_eq_affine_combination_of_points_with_circumcenter Affine.Simplex.mongePoint_eq_affineCombination_of_pointsWithCircumcenter
def mongePointVSubFaceCentroidWeightsWithCircumcenter {n : ℕ} (i₁ i₂ : Fin (n + 3)) :
PointsWithCircumcenterIndex (n + 2) → ℝ
| pointIndex i => if i = i₁ ∨ i = i₂ then ((n + 1 : ℕ) : ℝ)⁻¹ else 0
| circumcenterIndex => -2 / ((n + 1 : ℕ) : ℝ)
#align affine.simplex.monge_point_vsub_face_centroid_weights_with_circumcenter Affine.Simplex.mongePointVSubFaceCentroidWeightsWithCircumcenter
theorem mongePointVSubFaceCentroidWeightsWithCircumcenter_eq_sub {n : ℕ} {i₁ i₂ : Fin (n + 3)}
(h : i₁ ≠ i₂) :
mongePointVSubFaceCentroidWeightsWithCircumcenter i₁ i₂ =
mongePointWeightsWithCircumcenter n - centroidWeightsWithCircumcenter {i₁, i₂}ᶜ := by
ext i
cases' i with i
· rw [Pi.sub_apply, mongePointWeightsWithCircumcenter, centroidWeightsWithCircumcenter,
mongePointVSubFaceCentroidWeightsWithCircumcenter]
have hu : card ({i₁, i₂}ᶜ : Finset (Fin (n + 3))) = n + 1 := by
simp [card_compl, Fintype.card_fin, h]
rw [hu]
by_cases hi : i = i₁ ∨ i = i₂ <;> simp [compl_eq_univ_sdiff, hi]
· simp [mongePointWeightsWithCircumcenter, centroidWeightsWithCircumcenter,
mongePointVSubFaceCentroidWeightsWithCircumcenter]
#align affine.simplex.monge_point_vsub_face_centroid_weights_with_circumcenter_eq_sub Affine.Simplex.mongePointVSubFaceCentroidWeightsWithCircumcenter_eq_sub
@[simp]
theorem sum_mongePointVSubFaceCentroidWeightsWithCircumcenter {n : ℕ} {i₁ i₂ : Fin (n + 3)}
(h : i₁ ≠ i₂) : ∑ i, mongePointVSubFaceCentroidWeightsWithCircumcenter i₁ i₂ i = 0 := by
rw [mongePointVSubFaceCentroidWeightsWithCircumcenter_eq_sub h]
simp_rw [Pi.sub_apply, sum_sub_distrib, sum_mongePointWeightsWithCircumcenter]
rw [sum_centroidWeightsWithCircumcenter, sub_self]
simp [← card_pos, card_compl, h]
#align affine.simplex.sum_monge_point_vsub_face_centroid_weights_with_circumcenter Affine.Simplex.sum_mongePointVSubFaceCentroidWeightsWithCircumcenter
theorem mongePoint_vsub_face_centroid_eq_weightedVSub_of_pointsWithCircumcenter {n : ℕ}
(s : Simplex ℝ P (n + 2)) {i₁ i₂ : Fin (n + 3)} (h : i₁ ≠ i₂) :
s.mongePoint -ᵥ ({i₁, i₂}ᶜ : Finset (Fin (n + 3))).centroid ℝ s.points =
(univ : Finset (PointsWithCircumcenterIndex (n + 2))).weightedVSub s.pointsWithCircumcenter
(mongePointVSubFaceCentroidWeightsWithCircumcenter i₁ i₂) := by
simp_rw [mongePoint_eq_affineCombination_of_pointsWithCircumcenter,
centroid_eq_affineCombination_of_pointsWithCircumcenter, affineCombination_vsub,
mongePointVSubFaceCentroidWeightsWithCircumcenter_eq_sub h]
#align affine.simplex.monge_point_vsub_face_centroid_eq_weighted_vsub_of_points_with_circumcenter Affine.Simplex.mongePoint_vsub_face_centroid_eq_weightedVSub_of_pointsWithCircumcenter
theorem inner_mongePoint_vsub_face_centroid_vsub {n : ℕ} (s : Simplex ℝ P (n + 2))
{i₁ i₂ : Fin (n + 3)} :
⟪s.mongePoint -ᵥ ({i₁, i₂}ᶜ : Finset (Fin (n + 3))).centroid ℝ s.points,
s.points i₁ -ᵥ s.points i₂⟫ =
0 := by
by_cases h : i₁ = i₂
· simp [h]
simp_rw [mongePoint_vsub_face_centroid_eq_weightedVSub_of_pointsWithCircumcenter s h,
point_eq_affineCombination_of_pointsWithCircumcenter, affineCombination_vsub]
have hs : ∑ i, (pointWeightsWithCircumcenter i₁ - pointWeightsWithCircumcenter i₂) i = 0 := by
simp
rw [inner_weightedVSub _ (sum_mongePointVSubFaceCentroidWeightsWithCircumcenter h) _ hs,
sum_pointsWithCircumcenter, pointsWithCircumcenter_eq_circumcenter]
simp only [mongePointVSubFaceCentroidWeightsWithCircumcenter, pointsWithCircumcenter_point]
let fs : Finset (Fin (n + 3)) := {i₁, i₂}
have hfs : ∀ i : Fin (n + 3), i ∉ fs → i ≠ i₁ ∧ i ≠ i₂ := by
intro i hi
constructor <;> · intro hj; simp [fs, ← hj] at hi
rw [← sum_subset fs.subset_univ _]
· simp_rw [sum_pointsWithCircumcenter, pointsWithCircumcenter_eq_circumcenter,
pointsWithCircumcenter_point, Pi.sub_apply, pointWeightsWithCircumcenter]
rw [← sum_subset fs.subset_univ _]
· simp_rw [sum_insert (not_mem_singleton.2 h), sum_singleton]
repeat rw [← sum_subset fs.subset_univ _]
· simp_rw [sum_insert (not_mem_singleton.2 h), sum_singleton]
simp [h, Ne.symm h, dist_comm (s.points i₁)]
all_goals intro i _ hi; simp [hfs i hi]
· intro i _ hi
simp [hfs i hi, pointsWithCircumcenter]
· intro i _ hi
simp [hfs i hi]
#align affine.simplex.inner_monge_point_vsub_face_centroid_vsub Affine.Simplex.inner_mongePoint_vsub_face_centroid_vsub
def mongePlane {n : ℕ} (s : Simplex ℝ P (n + 2)) (i₁ i₂ : Fin (n + 3)) : AffineSubspace ℝ P :=
mk' (({i₁, i₂}ᶜ : Finset (Fin (n + 3))).centroid ℝ s.points) (ℝ ∙ s.points i₁ -ᵥ s.points i₂)ᗮ ⊓
affineSpan ℝ (Set.range s.points)
#align affine.simplex.monge_plane Affine.Simplex.mongePlane
theorem mongePlane_def {n : ℕ} (s : Simplex ℝ P (n + 2)) (i₁ i₂ : Fin (n + 3)) :
s.mongePlane i₁ i₂ =
mk' (({i₁, i₂}ᶜ : Finset (Fin (n + 3))).centroid ℝ s.points)
(ℝ ∙ s.points i₁ -ᵥ s.points i₂)ᗮ ⊓
affineSpan ℝ (Set.range s.points) :=
rfl
#align affine.simplex.monge_plane_def Affine.Simplex.mongePlane_def
theorem mongePlane_comm {n : ℕ} (s : Simplex ℝ P (n + 2)) (i₁ i₂ : Fin (n + 3)) :
s.mongePlane i₁ i₂ = s.mongePlane i₂ i₁ := by
simp_rw [mongePlane_def]
congr 3
· congr 1
exact pair_comm _ _
· ext
simp_rw [Submodule.mem_span_singleton]
constructor
all_goals rintro ⟨r, rfl⟩; use -r; rw [neg_smul, ← smul_neg, neg_vsub_eq_vsub_rev]
#align affine.simplex.monge_plane_comm Affine.Simplex.mongePlane_comm
theorem mongePoint_mem_mongePlane {n : ℕ} (s : Simplex ℝ P (n + 2)) {i₁ i₂ : Fin (n + 3)} :
s.mongePoint ∈ s.mongePlane i₁ i₂ := by
rw [mongePlane_def, mem_inf_iff, ← vsub_right_mem_direction_iff_mem (self_mem_mk' _ _),
direction_mk', Submodule.mem_orthogonal']
refine ⟨?_, s.mongePoint_mem_affineSpan⟩
intro v hv
rcases Submodule.mem_span_singleton.mp hv with ⟨r, rfl⟩
rw [inner_smul_right, s.inner_mongePoint_vsub_face_centroid_vsub, mul_zero]
#align affine.simplex.monge_point_mem_monge_plane Affine.Simplex.mongePoint_mem_mongePlane
theorem direction_mongePlane {n : ℕ} (s : Simplex ℝ P (n + 2)) {i₁ i₂ : Fin (n + 3)} :
(s.mongePlane i₁ i₂).direction =
(ℝ ∙ s.points i₁ -ᵥ s.points i₂)ᗮ ⊓ vectorSpan ℝ (Set.range s.points) := by
rw [mongePlane_def, direction_inf_of_mem_inf s.mongePoint_mem_mongePlane, direction_mk',
direction_affineSpan]
#align affine.simplex.direction_monge_plane Affine.Simplex.direction_mongePlane
theorem eq_mongePoint_of_forall_mem_mongePlane {n : ℕ} {s : Simplex ℝ P (n + 2)} {i₁ : Fin (n + 3)}
{p : P} (h : ∀ i₂, i₁ ≠ i₂ → p ∈ s.mongePlane i₁ i₂) : p = s.mongePoint := by
rw [← @vsub_eq_zero_iff_eq V]
have h' : ∀ i₂, i₁ ≠ i₂ → p -ᵥ s.mongePoint ∈
(ℝ ∙ s.points i₁ -ᵥ s.points i₂)ᗮ ⊓ vectorSpan ℝ (Set.range s.points) := by
intro i₂ hne
rw [← s.direction_mongePlane, vsub_right_mem_direction_iff_mem s.mongePoint_mem_mongePlane]
exact h i₂ hne
have hi : p -ᵥ s.mongePoint ∈ ⨅ i₂ : { i // i₁ ≠ i }, (ℝ ∙ s.points i₁ -ᵥ s.points i₂)ᗮ := by
rw [Submodule.mem_iInf]
exact fun i => (Submodule.mem_inf.1 (h' i i.property)).1
rw [Submodule.iInf_orthogonal, ← Submodule.span_iUnion] at hi
have hu :
⋃ i : { i // i₁ ≠ i }, ({s.points i₁ -ᵥ s.points i} : Set V) =
(s.points i₁ -ᵥ ·) '' (s.points '' (Set.univ \ {i₁})) := by
rw [Set.image_image]
ext x
simp_rw [Set.mem_iUnion, Set.mem_image, Set.mem_singleton_iff, Set.mem_diff_singleton]
constructor
· rintro ⟨i, rfl⟩
use i, ⟨Set.mem_univ _, i.property.symm⟩
· rintro ⟨i, ⟨-, hi⟩, rfl⟩
-- Porting note: was `use ⟨i, hi.symm⟩, rfl`
exact ⟨⟨i, hi.symm⟩, rfl⟩
rw [hu, ← vectorSpan_image_eq_span_vsub_set_left_ne ℝ _ (Set.mem_univ _), Set.image_univ] at hi
have hv : p -ᵥ s.mongePoint ∈ vectorSpan ℝ (Set.range s.points) := by
let s₁ : Finset (Fin (n + 3)) := univ.erase i₁
obtain ⟨i₂, h₂⟩ := card_pos.1 (show 0 < card s₁ by simp [s₁, card_erase_of_mem])
have h₁₂ : i₁ ≠ i₂ := (ne_of_mem_erase h₂).symm
exact (Submodule.mem_inf.1 (h' i₂ h₁₂)).2
exact Submodule.disjoint_def.1 (vectorSpan ℝ (Set.range s.points)).orthogonal_disjoint _ hv hi
#align affine.simplex.eq_monge_point_of_forall_mem_monge_plane Affine.Simplex.eq_mongePoint_of_forall_mem_mongePlane
def altitude {n : ℕ} (s : Simplex ℝ P (n + 1)) (i : Fin (n + 2)) : AffineSubspace ℝ P :=
mk' (s.points i) (affineSpan ℝ (s.points '' ↑(univ.erase i))).directionᗮ ⊓
affineSpan ℝ (Set.range s.points)
#align affine.simplex.altitude Affine.Simplex.altitude
theorem altitude_def {n : ℕ} (s : Simplex ℝ P (n + 1)) (i : Fin (n + 2)) :
s.altitude i =
mk' (s.points i) (affineSpan ℝ (s.points '' ↑(univ.erase i))).directionᗮ ⊓
affineSpan ℝ (Set.range s.points) :=
rfl
#align affine.simplex.altitude_def Affine.Simplex.altitude_def
theorem mem_altitude {n : ℕ} (s : Simplex ℝ P (n + 1)) (i : Fin (n + 2)) :
s.points i ∈ s.altitude i :=
(mem_inf_iff _ _ _).2 ⟨self_mem_mk' _ _, mem_affineSpan ℝ (Set.mem_range_self _)⟩
#align affine.simplex.mem_altitude Affine.Simplex.mem_altitude
| Mathlib/Geometry/Euclidean/MongePoint.lean | 352 | 357 | theorem direction_altitude {n : ℕ} (s : Simplex ℝ P (n + 1)) (i : Fin (n + 2)) :
(s.altitude i).direction =
(vectorSpan ℝ (s.points '' ↑(Finset.univ.erase i)))ᗮ ⊓ vectorSpan ℝ (Set.range s.points) := by |
rw [altitude_def,
direction_inf_of_mem (self_mem_mk' (s.points i) _) (mem_affineSpan ℝ (Set.mem_range_self _)),
direction_mk', direction_affineSpan, direction_affineSpan]
|
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
| Mathlib/Analysis/SpecialFunctions/Trigonometric/Angle.lean | 708 | 710 | 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]
|
import Mathlib.Analysis.SpecialFunctions.Exponential
#align_import analysis.special_functions.trigonometric.series from "leanprover-community/mathlib"@"ccf84e0d918668460a34aa19d02fe2e0e2286da0"
open NormedSpace
open scoped Nat
section SinCos
theorem Complex.hasSum_cos' (z : ℂ) :
HasSum (fun n : ℕ => (z * Complex.I) ^ (2 * n) / ↑(2 * n)!) (Complex.cos z) := by
rw [Complex.cos, Complex.exp_eq_exp_ℂ]
have := ((expSeries_div_hasSum_exp ℂ (z * Complex.I)).add
(expSeries_div_hasSum_exp ℂ (-z * Complex.I))).div_const 2
replace := (Nat.divModEquiv 2).symm.hasSum_iff.mpr this
dsimp [Function.comp_def] at this
simp_rw [← mul_comm 2 _] at this
refine this.prod_fiberwise fun k => ?_
dsimp only
convert hasSum_fintype (_ : Fin 2 → ℂ) using 1
rw [Fin.sum_univ_two]
simp_rw [Fin.val_zero, Fin.val_one, add_zero, pow_succ, pow_mul, mul_pow, neg_sq, ← two_mul,
neg_mul, mul_neg, neg_div, add_right_neg, zero_div, add_zero,
mul_div_cancel_left₀ _ (two_ne_zero : (2 : ℂ) ≠ 0)]
#align complex.has_sum_cos' Complex.hasSum_cos'
| Mathlib/Analysis/SpecialFunctions/Trigonometric/Series.lean | 49 | 64 | theorem Complex.hasSum_sin' (z : ℂ) :
HasSum (fun n : ℕ => (z * Complex.I) ^ (2 * n + 1) / ↑(2 * n + 1)! / Complex.I)
(Complex.sin z) := by |
rw [Complex.sin, Complex.exp_eq_exp_ℂ]
have := (((expSeries_div_hasSum_exp ℂ (-z * Complex.I)).sub
(expSeries_div_hasSum_exp ℂ (z * Complex.I))).mul_right Complex.I).div_const 2
replace := (Nat.divModEquiv 2).symm.hasSum_iff.mpr this
dsimp [Function.comp_def] at this
simp_rw [← mul_comm 2 _] at this
refine this.prod_fiberwise fun k => ?_
dsimp only
convert hasSum_fintype (_ : Fin 2 → ℂ) using 1
rw [Fin.sum_univ_two]
simp_rw [Fin.val_zero, Fin.val_one, add_zero, pow_succ, pow_mul, mul_pow, neg_sq, sub_self,
zero_mul, zero_div, zero_add, neg_mul, mul_neg, neg_div, ← neg_add', ← two_mul,
neg_mul, neg_div, mul_assoc, mul_div_cancel_left₀ _ (two_ne_zero : (2 : ℂ) ≠ 0), Complex.div_I]
|
import Mathlib.LinearAlgebra.Projectivization.Basic
#align_import linear_algebra.projective_space.independence from "leanprover-community/mathlib"@"1e82f5ec4645f6a92bb9e02fce51e44e3bc3e1fe"
open scoped LinearAlgebra.Projectivization
variable {ι K V : Type*} [DivisionRing K] [AddCommGroup V] [Module K V] {f : ι → ℙ K V}
namespace Projectivization
inductive Independent : (ι → ℙ K V) → Prop
| mk (f : ι → V) (hf : ∀ i : ι, f i ≠ 0) (hl : LinearIndependent K f) :
Independent fun i => mk K (f i) (hf i)
#align projectivization.independent Projectivization.Independent
theorem independent_iff : Independent f ↔ LinearIndependent K (Projectivization.rep ∘ f) := by
refine ⟨?_, fun h => ?_⟩
· rintro ⟨ff, hff, hh⟩
choose a ha using fun i : ι => exists_smul_eq_mk_rep K (ff i) (hff i)
convert hh.units_smul a
ext i
exact (ha i).symm
· convert Independent.mk _ _ h
· simp only [mk_rep, Function.comp_apply]
· intro i
apply rep_nonzero
#align projectivization.independent_iff Projectivization.independent_iff
| Mathlib/LinearAlgebra/Projectivization/Independence.lean | 63 | 72 | theorem independent_iff_completeLattice_independent :
Independent f ↔ CompleteLattice.Independent fun i => (f i).submodule := by |
refine ⟨?_, fun h => ?_⟩
· rintro ⟨f, hf, hi⟩
simp only [submodule_mk]
exact (CompleteLattice.independent_iff_linearIndependent_of_ne_zero (R := K) hf).mpr hi
· rw [independent_iff]
refine h.linearIndependent (Projectivization.submodule ∘ f) (fun i => ?_) fun i => ?_
· simpa only [Function.comp_apply, submodule_eq] using Submodule.mem_span_singleton_self _
· exact rep_nonzero (f i)
|
import Mathlib.Data.ENNReal.Inv
#align_import data.real.ennreal from "leanprover-community/mathlib"@"c14c8fcde993801fca8946b0d80131a1a81d1520"
open Set NNReal ENNReal
namespace ENNReal
section Real
variable {a b c d : ℝ≥0∞} {r p q : ℝ≥0}
theorem toReal_add (ha : a ≠ ∞) (hb : b ≠ ∞) : (a + b).toReal = a.toReal + b.toReal := by
lift a to ℝ≥0 using ha
lift b to ℝ≥0 using hb
rfl
#align ennreal.to_real_add ENNReal.toReal_add
theorem toReal_sub_of_le {a b : ℝ≥0∞} (h : b ≤ a) (ha : a ≠ ∞) :
(a - b).toReal = a.toReal - b.toReal := by
lift b to ℝ≥0 using ne_top_of_le_ne_top ha h
lift a to ℝ≥0 using ha
simp only [← ENNReal.coe_sub, ENNReal.coe_toReal, NNReal.coe_sub (ENNReal.coe_le_coe.mp h)]
#align ennreal.to_real_sub_of_le ENNReal.toReal_sub_of_le
theorem le_toReal_sub {a b : ℝ≥0∞} (hb : b ≠ ∞) : a.toReal - b.toReal ≤ (a - b).toReal := by
lift b to ℝ≥0 using hb
induction a
· simp
· simp only [← coe_sub, NNReal.sub_def, Real.coe_toNNReal', coe_toReal]
exact le_max_left _ _
#align ennreal.le_to_real_sub ENNReal.le_toReal_sub
theorem toReal_add_le : (a + b).toReal ≤ a.toReal + b.toReal :=
if ha : a = ∞ then by simp only [ha, top_add, top_toReal, zero_add, toReal_nonneg]
else
if hb : b = ∞ then by simp only [hb, add_top, top_toReal, add_zero, toReal_nonneg]
else le_of_eq (toReal_add ha hb)
#align ennreal.to_real_add_le ENNReal.toReal_add_le
theorem ofReal_add {p q : ℝ} (hp : 0 ≤ p) (hq : 0 ≤ q) :
ENNReal.ofReal (p + q) = ENNReal.ofReal p + ENNReal.ofReal q := by
rw [ENNReal.ofReal, ENNReal.ofReal, ENNReal.ofReal, ← coe_add, coe_inj,
Real.toNNReal_add hp hq]
#align ennreal.of_real_add ENNReal.ofReal_add
theorem ofReal_add_le {p q : ℝ} : ENNReal.ofReal (p + q) ≤ ENNReal.ofReal p + ENNReal.ofReal q :=
coe_le_coe.2 Real.toNNReal_add_le
#align ennreal.of_real_add_le ENNReal.ofReal_add_le
@[simp]
| Mathlib/Data/ENNReal/Real.lean | 76 | 79 | theorem toReal_le_toReal (ha : a ≠ ∞) (hb : b ≠ ∞) : a.toReal ≤ b.toReal ↔ a ≤ b := by |
lift a to ℝ≥0 using ha
lift b to ℝ≥0 using hb
norm_cast
|
import Mathlib.Algebra.Algebra.Operations
import Mathlib.Algebra.Algebra.Subalgebra.Basic
import Mathlib.Algebra.DirectSum.Algebra
#align_import algebra.direct_sum.internal from "leanprover-community/mathlib"@"9936c3dfc04e5876f4368aeb2e60f8d8358d095a"
open DirectSum
variable {ι : Type*} {σ S R : Type*}
instance AddCommMonoid.ofSubmonoidOnSemiring [Semiring R] [SetLike σ R] [AddSubmonoidClass σ R]
(A : ι → σ) : ∀ i, AddCommMonoid (A i) := fun i => by infer_instance
#align add_comm_monoid.of_submonoid_on_semiring AddCommMonoid.ofSubmonoidOnSemiring
instance AddCommGroup.ofSubgroupOnRing [Ring R] [SetLike σ R] [AddSubgroupClass σ R] (A : ι → σ) :
∀ i, AddCommGroup (A i) := fun i => by infer_instance
#align add_comm_group.of_subgroup_on_ring AddCommGroup.ofSubgroupOnRing
theorem SetLike.algebraMap_mem_graded [Zero ι] [CommSemiring S] [Semiring R] [Algebra S R]
(A : ι → Submodule S R) [SetLike.GradedOne A] (s : S) : algebraMap S R s ∈ A 0 := by
rw [Algebra.algebraMap_eq_smul_one]
exact (A 0).smul_mem s <| SetLike.one_mem_graded _
#align set_like.algebra_map_mem_graded SetLike.algebraMap_mem_graded
| Mathlib/Algebra/DirectSum/Internal.lean | 62 | 68 | theorem SetLike.natCast_mem_graded [Zero ι] [AddMonoidWithOne R] [SetLike σ R]
[AddSubmonoidClass σ R] (A : ι → σ) [SetLike.GradedOne A] (n : ℕ) : (n : R) ∈ A 0 := by |
induction' n with _ n_ih
· rw [Nat.cast_zero]
exact zero_mem (A 0)
· rw [Nat.cast_succ]
exact add_mem n_ih (SetLike.one_mem_graded _)
|
import Mathlib.Geometry.Euclidean.Angle.Oriented.Affine
import Mathlib.Geometry.Euclidean.Angle.Unoriented.RightAngle
#align_import geometry.euclidean.angle.oriented.right_angle from "leanprover-community/mathlib"@"46b633fd842bef9469441c0209906f6dddd2b4f5"
noncomputable section
open scoped EuclideanGeometry
open scoped Real
open scoped RealInnerProductSpace
namespace Orientation
open FiniteDimensional
variable {V : Type*} [NormedAddCommGroup V] [InnerProductSpace ℝ V]
variable [hd2 : Fact (finrank ℝ V = 2)] (o : Orientation ℝ V (Fin 2))
theorem oangle_add_right_eq_arccos_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
o.oangle x (x + y) = Real.arccos (‖x‖ / ‖x + y‖) := by
have hs : (o.oangle x (x + y)).sign = 1 := by
rw [oangle_sign_add_right, h, Real.Angle.sign_coe_pi_div_two]
rw [o.oangle_eq_angle_of_sign_eq_one hs,
InnerProductGeometry.angle_add_eq_arccos_of_inner_eq_zero
(o.inner_eq_zero_of_oangle_eq_pi_div_two h)]
#align orientation.oangle_add_right_eq_arccos_of_oangle_eq_pi_div_two Orientation.oangle_add_right_eq_arccos_of_oangle_eq_pi_div_two
theorem oangle_add_left_eq_arccos_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
o.oangle (x + y) y = Real.arccos (‖y‖ / ‖x + y‖) := by
rw [← neg_inj, oangle_rev, ← oangle_neg_orientation_eq_neg, neg_inj] at h ⊢
rw [add_comm]
exact (-o).oangle_add_right_eq_arccos_of_oangle_eq_pi_div_two h
#align orientation.oangle_add_left_eq_arccos_of_oangle_eq_pi_div_two Orientation.oangle_add_left_eq_arccos_of_oangle_eq_pi_div_two
theorem oangle_add_right_eq_arcsin_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
o.oangle x (x + y) = Real.arcsin (‖y‖ / ‖x + y‖) := by
have hs : (o.oangle x (x + y)).sign = 1 := by
rw [oangle_sign_add_right, h, Real.Angle.sign_coe_pi_div_two]
rw [o.oangle_eq_angle_of_sign_eq_one hs,
InnerProductGeometry.angle_add_eq_arcsin_of_inner_eq_zero
(o.inner_eq_zero_of_oangle_eq_pi_div_two h)
(Or.inl (o.left_ne_zero_of_oangle_eq_pi_div_two h))]
#align orientation.oangle_add_right_eq_arcsin_of_oangle_eq_pi_div_two Orientation.oangle_add_right_eq_arcsin_of_oangle_eq_pi_div_two
theorem oangle_add_left_eq_arcsin_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
o.oangle (x + y) y = Real.arcsin (‖x‖ / ‖x + y‖) := by
rw [← neg_inj, oangle_rev, ← oangle_neg_orientation_eq_neg, neg_inj] at h ⊢
rw [add_comm]
exact (-o).oangle_add_right_eq_arcsin_of_oangle_eq_pi_div_two h
#align orientation.oangle_add_left_eq_arcsin_of_oangle_eq_pi_div_two Orientation.oangle_add_left_eq_arcsin_of_oangle_eq_pi_div_two
theorem oangle_add_right_eq_arctan_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
o.oangle x (x + y) = Real.arctan (‖y‖ / ‖x‖) := by
have hs : (o.oangle x (x + y)).sign = 1 := by
rw [oangle_sign_add_right, h, Real.Angle.sign_coe_pi_div_two]
rw [o.oangle_eq_angle_of_sign_eq_one hs,
InnerProductGeometry.angle_add_eq_arctan_of_inner_eq_zero
(o.inner_eq_zero_of_oangle_eq_pi_div_two h) (o.left_ne_zero_of_oangle_eq_pi_div_two h)]
#align orientation.oangle_add_right_eq_arctan_of_oangle_eq_pi_div_two Orientation.oangle_add_right_eq_arctan_of_oangle_eq_pi_div_two
theorem oangle_add_left_eq_arctan_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
o.oangle (x + y) y = Real.arctan (‖x‖ / ‖y‖) := by
rw [← neg_inj, oangle_rev, ← oangle_neg_orientation_eq_neg, neg_inj] at h ⊢
rw [add_comm]
exact (-o).oangle_add_right_eq_arctan_of_oangle_eq_pi_div_two h
#align orientation.oangle_add_left_eq_arctan_of_oangle_eq_pi_div_two Orientation.oangle_add_left_eq_arctan_of_oangle_eq_pi_div_two
theorem cos_oangle_add_right_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
Real.Angle.cos (o.oangle x (x + y)) = ‖x‖ / ‖x + y‖ := by
have hs : (o.oangle x (x + y)).sign = 1 := by
rw [oangle_sign_add_right, h, Real.Angle.sign_coe_pi_div_two]
rw [o.oangle_eq_angle_of_sign_eq_one hs, Real.Angle.cos_coe,
InnerProductGeometry.cos_angle_add_of_inner_eq_zero (o.inner_eq_zero_of_oangle_eq_pi_div_two h)]
#align orientation.cos_oangle_add_right_of_oangle_eq_pi_div_two Orientation.cos_oangle_add_right_of_oangle_eq_pi_div_two
theorem cos_oangle_add_left_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
Real.Angle.cos (o.oangle (x + y) y) = ‖y‖ / ‖x + y‖ := by
rw [← neg_inj, oangle_rev, ← oangle_neg_orientation_eq_neg, neg_inj] at h ⊢
rw [add_comm]
exact (-o).cos_oangle_add_right_of_oangle_eq_pi_div_two h
#align orientation.cos_oangle_add_left_of_oangle_eq_pi_div_two Orientation.cos_oangle_add_left_of_oangle_eq_pi_div_two
theorem sin_oangle_add_right_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
Real.Angle.sin (o.oangle x (x + y)) = ‖y‖ / ‖x + y‖ := by
have hs : (o.oangle x (x + y)).sign = 1 := by
rw [oangle_sign_add_right, h, Real.Angle.sign_coe_pi_div_two]
rw [o.oangle_eq_angle_of_sign_eq_one hs, Real.Angle.sin_coe,
InnerProductGeometry.sin_angle_add_of_inner_eq_zero (o.inner_eq_zero_of_oangle_eq_pi_div_two h)
(Or.inl (o.left_ne_zero_of_oangle_eq_pi_div_two h))]
#align orientation.sin_oangle_add_right_of_oangle_eq_pi_div_two Orientation.sin_oangle_add_right_of_oangle_eq_pi_div_two
theorem sin_oangle_add_left_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
Real.Angle.sin (o.oangle (x + y) y) = ‖x‖ / ‖x + y‖ := by
rw [← neg_inj, oangle_rev, ← oangle_neg_orientation_eq_neg, neg_inj] at h ⊢
rw [add_comm]
exact (-o).sin_oangle_add_right_of_oangle_eq_pi_div_two h
#align orientation.sin_oangle_add_left_of_oangle_eq_pi_div_two Orientation.sin_oangle_add_left_of_oangle_eq_pi_div_two
theorem tan_oangle_add_right_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
Real.Angle.tan (o.oangle x (x + y)) = ‖y‖ / ‖x‖ := by
have hs : (o.oangle x (x + y)).sign = 1 := by
rw [oangle_sign_add_right, h, Real.Angle.sign_coe_pi_div_two]
rw [o.oangle_eq_angle_of_sign_eq_one hs, Real.Angle.tan_coe,
InnerProductGeometry.tan_angle_add_of_inner_eq_zero (o.inner_eq_zero_of_oangle_eq_pi_div_two h)]
#align orientation.tan_oangle_add_right_of_oangle_eq_pi_div_two Orientation.tan_oangle_add_right_of_oangle_eq_pi_div_two
theorem tan_oangle_add_left_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
Real.Angle.tan (o.oangle (x + y) y) = ‖x‖ / ‖y‖ := by
rw [← neg_inj, oangle_rev, ← oangle_neg_orientation_eq_neg, neg_inj] at h ⊢
rw [add_comm]
exact (-o).tan_oangle_add_right_of_oangle_eq_pi_div_two h
#align orientation.tan_oangle_add_left_of_oangle_eq_pi_div_two Orientation.tan_oangle_add_left_of_oangle_eq_pi_div_two
theorem cos_oangle_add_right_mul_norm_of_oangle_eq_pi_div_two {x y : V}
(h : o.oangle x y = ↑(π / 2)) : Real.Angle.cos (o.oangle x (x + y)) * ‖x + y‖ = ‖x‖ := by
have hs : (o.oangle x (x + y)).sign = 1 := by
rw [oangle_sign_add_right, h, Real.Angle.sign_coe_pi_div_two]
rw [o.oangle_eq_angle_of_sign_eq_one hs, Real.Angle.cos_coe,
InnerProductGeometry.cos_angle_add_mul_norm_of_inner_eq_zero
(o.inner_eq_zero_of_oangle_eq_pi_div_two h)]
#align orientation.cos_oangle_add_right_mul_norm_of_oangle_eq_pi_div_two Orientation.cos_oangle_add_right_mul_norm_of_oangle_eq_pi_div_two
theorem cos_oangle_add_left_mul_norm_of_oangle_eq_pi_div_two {x y : V}
(h : o.oangle x y = ↑(π / 2)) : Real.Angle.cos (o.oangle (x + y) y) * ‖x + y‖ = ‖y‖ := by
rw [← neg_inj, oangle_rev, ← oangle_neg_orientation_eq_neg, neg_inj] at h ⊢
rw [add_comm]
exact (-o).cos_oangle_add_right_mul_norm_of_oangle_eq_pi_div_two h
#align orientation.cos_oangle_add_left_mul_norm_of_oangle_eq_pi_div_two Orientation.cos_oangle_add_left_mul_norm_of_oangle_eq_pi_div_two
theorem sin_oangle_add_right_mul_norm_of_oangle_eq_pi_div_two {x y : V}
(h : o.oangle x y = ↑(π / 2)) : Real.Angle.sin (o.oangle x (x + y)) * ‖x + y‖ = ‖y‖ := by
have hs : (o.oangle x (x + y)).sign = 1 := by
rw [oangle_sign_add_right, h, Real.Angle.sign_coe_pi_div_two]
rw [o.oangle_eq_angle_of_sign_eq_one hs, Real.Angle.sin_coe,
InnerProductGeometry.sin_angle_add_mul_norm_of_inner_eq_zero
(o.inner_eq_zero_of_oangle_eq_pi_div_two h)]
#align orientation.sin_oangle_add_right_mul_norm_of_oangle_eq_pi_div_two Orientation.sin_oangle_add_right_mul_norm_of_oangle_eq_pi_div_two
theorem sin_oangle_add_left_mul_norm_of_oangle_eq_pi_div_two {x y : V}
(h : o.oangle x y = ↑(π / 2)) : Real.Angle.sin (o.oangle (x + y) y) * ‖x + y‖ = ‖x‖ := by
rw [← neg_inj, oangle_rev, ← oangle_neg_orientation_eq_neg, neg_inj] at h ⊢
rw [add_comm]
exact (-o).sin_oangle_add_right_mul_norm_of_oangle_eq_pi_div_two h
#align orientation.sin_oangle_add_left_mul_norm_of_oangle_eq_pi_div_two Orientation.sin_oangle_add_left_mul_norm_of_oangle_eq_pi_div_two
theorem tan_oangle_add_right_mul_norm_of_oangle_eq_pi_div_two {x y : V}
(h : o.oangle x y = ↑(π / 2)) : Real.Angle.tan (o.oangle x (x + y)) * ‖x‖ = ‖y‖ := by
have hs : (o.oangle x (x + y)).sign = 1 := by
rw [oangle_sign_add_right, h, Real.Angle.sign_coe_pi_div_two]
rw [o.oangle_eq_angle_of_sign_eq_one hs, Real.Angle.tan_coe,
InnerProductGeometry.tan_angle_add_mul_norm_of_inner_eq_zero
(o.inner_eq_zero_of_oangle_eq_pi_div_two h)
(Or.inl (o.left_ne_zero_of_oangle_eq_pi_div_two h))]
#align orientation.tan_oangle_add_right_mul_norm_of_oangle_eq_pi_div_two Orientation.tan_oangle_add_right_mul_norm_of_oangle_eq_pi_div_two
theorem tan_oangle_add_left_mul_norm_of_oangle_eq_pi_div_two {x y : V}
(h : o.oangle x y = ↑(π / 2)) : Real.Angle.tan (o.oangle (x + y) y) * ‖y‖ = ‖x‖ := by
rw [← neg_inj, oangle_rev, ← oangle_neg_orientation_eq_neg, neg_inj] at h ⊢
rw [add_comm]
exact (-o).tan_oangle_add_right_mul_norm_of_oangle_eq_pi_div_two h
#align orientation.tan_oangle_add_left_mul_norm_of_oangle_eq_pi_div_two Orientation.tan_oangle_add_left_mul_norm_of_oangle_eq_pi_div_two
theorem norm_div_cos_oangle_add_right_of_oangle_eq_pi_div_two {x y : V}
(h : o.oangle x y = ↑(π / 2)) : ‖x‖ / Real.Angle.cos (o.oangle x (x + y)) = ‖x + y‖ := by
have hs : (o.oangle x (x + y)).sign = 1 := by
rw [oangle_sign_add_right, h, Real.Angle.sign_coe_pi_div_two]
rw [o.oangle_eq_angle_of_sign_eq_one hs, Real.Angle.cos_coe,
InnerProductGeometry.norm_div_cos_angle_add_of_inner_eq_zero
(o.inner_eq_zero_of_oangle_eq_pi_div_two h)
(Or.inl (o.left_ne_zero_of_oangle_eq_pi_div_two h))]
#align orientation.norm_div_cos_oangle_add_right_of_oangle_eq_pi_div_two Orientation.norm_div_cos_oangle_add_right_of_oangle_eq_pi_div_two
theorem norm_div_cos_oangle_add_left_of_oangle_eq_pi_div_two {x y : V}
(h : o.oangle x y = ↑(π / 2)) : ‖y‖ / Real.Angle.cos (o.oangle (x + y) y) = ‖x + y‖ := by
rw [← neg_inj, oangle_rev, ← oangle_neg_orientation_eq_neg, neg_inj] at h ⊢
rw [add_comm]
exact (-o).norm_div_cos_oangle_add_right_of_oangle_eq_pi_div_two h
#align orientation.norm_div_cos_oangle_add_left_of_oangle_eq_pi_div_two Orientation.norm_div_cos_oangle_add_left_of_oangle_eq_pi_div_two
theorem norm_div_sin_oangle_add_right_of_oangle_eq_pi_div_two {x y : V}
(h : o.oangle x y = ↑(π / 2)) : ‖y‖ / Real.Angle.sin (o.oangle x (x + y)) = ‖x + y‖ := by
have hs : (o.oangle x (x + y)).sign = 1 := by
rw [oangle_sign_add_right, h, Real.Angle.sign_coe_pi_div_two]
rw [o.oangle_eq_angle_of_sign_eq_one hs, Real.Angle.sin_coe,
InnerProductGeometry.norm_div_sin_angle_add_of_inner_eq_zero
(o.inner_eq_zero_of_oangle_eq_pi_div_two h)
(Or.inr (o.right_ne_zero_of_oangle_eq_pi_div_two h))]
#align orientation.norm_div_sin_oangle_add_right_of_oangle_eq_pi_div_two Orientation.norm_div_sin_oangle_add_right_of_oangle_eq_pi_div_two
theorem norm_div_sin_oangle_add_left_of_oangle_eq_pi_div_two {x y : V}
(h : o.oangle x y = ↑(π / 2)) : ‖x‖ / Real.Angle.sin (o.oangle (x + y) y) = ‖x + y‖ := by
rw [← neg_inj, oangle_rev, ← oangle_neg_orientation_eq_neg, neg_inj] at h ⊢
rw [add_comm]
exact (-o).norm_div_sin_oangle_add_right_of_oangle_eq_pi_div_two h
#align orientation.norm_div_sin_oangle_add_left_of_oangle_eq_pi_div_two Orientation.norm_div_sin_oangle_add_left_of_oangle_eq_pi_div_two
theorem norm_div_tan_oangle_add_right_of_oangle_eq_pi_div_two {x y : V}
(h : o.oangle x y = ↑(π / 2)) : ‖y‖ / Real.Angle.tan (o.oangle x (x + y)) = ‖x‖ := by
have hs : (o.oangle x (x + y)).sign = 1 := by
rw [oangle_sign_add_right, h, Real.Angle.sign_coe_pi_div_two]
rw [o.oangle_eq_angle_of_sign_eq_one hs, Real.Angle.tan_coe,
InnerProductGeometry.norm_div_tan_angle_add_of_inner_eq_zero
(o.inner_eq_zero_of_oangle_eq_pi_div_two h)
(Or.inr (o.right_ne_zero_of_oangle_eq_pi_div_two h))]
#align orientation.norm_div_tan_oangle_add_right_of_oangle_eq_pi_div_two Orientation.norm_div_tan_oangle_add_right_of_oangle_eq_pi_div_two
theorem norm_div_tan_oangle_add_left_of_oangle_eq_pi_div_two {x y : V}
(h : o.oangle x y = ↑(π / 2)) : ‖x‖ / Real.Angle.tan (o.oangle (x + y) y) = ‖y‖ := by
rw [← neg_inj, oangle_rev, ← oangle_neg_orientation_eq_neg, neg_inj] at h ⊢
rw [add_comm]
exact (-o).norm_div_tan_oangle_add_right_of_oangle_eq_pi_div_two h
#align orientation.norm_div_tan_oangle_add_left_of_oangle_eq_pi_div_two Orientation.norm_div_tan_oangle_add_left_of_oangle_eq_pi_div_two
theorem oangle_sub_right_eq_arccos_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
o.oangle y (y - x) = Real.arccos (‖y‖ / ‖y - x‖) := by
have hs : (o.oangle y (y - x)).sign = 1 := by
rw [oangle_sign_sub_right_swap, h, Real.Angle.sign_coe_pi_div_two]
rw [o.oangle_eq_angle_of_sign_eq_one hs,
InnerProductGeometry.angle_sub_eq_arccos_of_inner_eq_zero
(o.inner_rev_eq_zero_of_oangle_eq_pi_div_two h)]
#align orientation.oangle_sub_right_eq_arccos_of_oangle_eq_pi_div_two Orientation.oangle_sub_right_eq_arccos_of_oangle_eq_pi_div_two
theorem oangle_sub_left_eq_arccos_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
o.oangle (x - y) x = Real.arccos (‖x‖ / ‖x - y‖) := by
rw [← neg_inj, oangle_rev, ← oangle_neg_orientation_eq_neg, neg_inj] at h ⊢
exact (-o).oangle_sub_right_eq_arccos_of_oangle_eq_pi_div_two h
#align orientation.oangle_sub_left_eq_arccos_of_oangle_eq_pi_div_two Orientation.oangle_sub_left_eq_arccos_of_oangle_eq_pi_div_two
theorem oangle_sub_right_eq_arcsin_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
o.oangle y (y - x) = Real.arcsin (‖x‖ / ‖y - x‖) := by
have hs : (o.oangle y (y - x)).sign = 1 := by
rw [oangle_sign_sub_right_swap, h, Real.Angle.sign_coe_pi_div_two]
rw [o.oangle_eq_angle_of_sign_eq_one hs,
InnerProductGeometry.angle_sub_eq_arcsin_of_inner_eq_zero
(o.inner_rev_eq_zero_of_oangle_eq_pi_div_two h)
(Or.inl (o.right_ne_zero_of_oangle_eq_pi_div_two h))]
#align orientation.oangle_sub_right_eq_arcsin_of_oangle_eq_pi_div_two Orientation.oangle_sub_right_eq_arcsin_of_oangle_eq_pi_div_two
theorem oangle_sub_left_eq_arcsin_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
o.oangle (x - y) x = Real.arcsin (‖y‖ / ‖x - y‖) := by
rw [← neg_inj, oangle_rev, ← oangle_neg_orientation_eq_neg, neg_inj] at h ⊢
exact (-o).oangle_sub_right_eq_arcsin_of_oangle_eq_pi_div_two h
#align orientation.oangle_sub_left_eq_arcsin_of_oangle_eq_pi_div_two Orientation.oangle_sub_left_eq_arcsin_of_oangle_eq_pi_div_two
theorem oangle_sub_right_eq_arctan_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
o.oangle y (y - x) = Real.arctan (‖x‖ / ‖y‖) := by
have hs : (o.oangle y (y - x)).sign = 1 := by
rw [oangle_sign_sub_right_swap, h, Real.Angle.sign_coe_pi_div_two]
rw [o.oangle_eq_angle_of_sign_eq_one hs,
InnerProductGeometry.angle_sub_eq_arctan_of_inner_eq_zero
(o.inner_rev_eq_zero_of_oangle_eq_pi_div_two h) (o.right_ne_zero_of_oangle_eq_pi_div_two h)]
#align orientation.oangle_sub_right_eq_arctan_of_oangle_eq_pi_div_two Orientation.oangle_sub_right_eq_arctan_of_oangle_eq_pi_div_two
theorem oangle_sub_left_eq_arctan_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
o.oangle (x - y) x = Real.arctan (‖y‖ / ‖x‖) := by
rw [← neg_inj, oangle_rev, ← oangle_neg_orientation_eq_neg, neg_inj] at h ⊢
exact (-o).oangle_sub_right_eq_arctan_of_oangle_eq_pi_div_two h
#align orientation.oangle_sub_left_eq_arctan_of_oangle_eq_pi_div_two Orientation.oangle_sub_left_eq_arctan_of_oangle_eq_pi_div_two
theorem cos_oangle_sub_right_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
Real.Angle.cos (o.oangle y (y - x)) = ‖y‖ / ‖y - x‖ := by
have hs : (o.oangle y (y - x)).sign = 1 := by
rw [oangle_sign_sub_right_swap, h, Real.Angle.sign_coe_pi_div_two]
rw [o.oangle_eq_angle_of_sign_eq_one hs, Real.Angle.cos_coe,
InnerProductGeometry.cos_angle_sub_of_inner_eq_zero
(o.inner_rev_eq_zero_of_oangle_eq_pi_div_two h)]
#align orientation.cos_oangle_sub_right_of_oangle_eq_pi_div_two Orientation.cos_oangle_sub_right_of_oangle_eq_pi_div_two
theorem cos_oangle_sub_left_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
Real.Angle.cos (o.oangle (x - y) x) = ‖x‖ / ‖x - y‖ := by
rw [← neg_inj, oangle_rev, ← oangle_neg_orientation_eq_neg, neg_inj] at h ⊢
exact (-o).cos_oangle_sub_right_of_oangle_eq_pi_div_two h
#align orientation.cos_oangle_sub_left_of_oangle_eq_pi_div_two Orientation.cos_oangle_sub_left_of_oangle_eq_pi_div_two
theorem sin_oangle_sub_right_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
Real.Angle.sin (o.oangle y (y - x)) = ‖x‖ / ‖y - x‖ := by
have hs : (o.oangle y (y - x)).sign = 1 := by
rw [oangle_sign_sub_right_swap, h, Real.Angle.sign_coe_pi_div_two]
rw [o.oangle_eq_angle_of_sign_eq_one hs, Real.Angle.sin_coe,
InnerProductGeometry.sin_angle_sub_of_inner_eq_zero
(o.inner_rev_eq_zero_of_oangle_eq_pi_div_two h)
(Or.inl (o.right_ne_zero_of_oangle_eq_pi_div_two h))]
#align orientation.sin_oangle_sub_right_of_oangle_eq_pi_div_two Orientation.sin_oangle_sub_right_of_oangle_eq_pi_div_two
| Mathlib/Geometry/Euclidean/Angle/Oriented/RightAngle.lean | 351 | 354 | theorem sin_oangle_sub_left_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
Real.Angle.sin (o.oangle (x - y) x) = ‖y‖ / ‖x - y‖ := by |
rw [← neg_inj, oangle_rev, ← oangle_neg_orientation_eq_neg, neg_inj] at h ⊢
exact (-o).sin_oangle_sub_right_of_oangle_eq_pi_div_two h
|
import Mathlib.CategoryTheory.Limits.Preserves.Shapes.Zero
#align_import category_theory.limits.shapes.kernels from "leanprover-community/mathlib"@"956af7c76589f444f2e1313911bad16366ea476d"
noncomputable section
universe v v₂ u u' u₂
open CategoryTheory
open CategoryTheory.Limits.WalkingParallelPair
namespace CategoryTheory.Limits
variable {C : Type u} [Category.{v} C]
variable [HasZeroMorphisms C]
abbrev HasKernel {X Y : C} (f : X ⟶ Y) : Prop :=
HasLimit (parallelPair f 0)
#align category_theory.limits.has_kernel CategoryTheory.Limits.HasKernel
abbrev HasCokernel {X Y : C} (f : X ⟶ Y) : Prop :=
HasColimit (parallelPair f 0)
#align category_theory.limits.has_cokernel CategoryTheory.Limits.HasCokernel
variable {X Y : C} (f : X ⟶ Y)
section
abbrev KernelFork :=
Fork f 0
#align category_theory.limits.kernel_fork CategoryTheory.Limits.KernelFork
variable {f}
@[reassoc (attr := simp)]
theorem KernelFork.condition (s : KernelFork f) : Fork.ι s ≫ f = 0 := by
erw [Fork.condition, HasZeroMorphisms.comp_zero]
#align category_theory.limits.kernel_fork.condition CategoryTheory.Limits.KernelFork.condition
-- Porting note (#10618): simp can prove this, removed simp tag
theorem KernelFork.app_one (s : KernelFork f) : s.π.app one = 0 := by
simp [Fork.app_one_eq_ι_comp_right]
#align category_theory.limits.kernel_fork.app_one CategoryTheory.Limits.KernelFork.app_one
abbrev KernelFork.ofι {Z : C} (ι : Z ⟶ X) (w : ι ≫ f = 0) : KernelFork f :=
Fork.ofι ι <| by rw [w, HasZeroMorphisms.comp_zero]
#align category_theory.limits.kernel_fork.of_ι CategoryTheory.Limits.KernelFork.ofι
@[simp]
theorem KernelFork.ι_ofι {X Y P : C} (f : X ⟶ Y) (ι : P ⟶ X) (w : ι ≫ f = 0) :
Fork.ι (KernelFork.ofι ι w) = ι := rfl
#align category_theory.limits.kernel_fork.ι_of_ι CategoryTheory.Limits.KernelFork.ι_ofι
section
-- attribute [local tidy] tactic.case_bash Porting note: no tidy nor case_bash
def isoOfι (s : Fork f 0) : s ≅ Fork.ofι (Fork.ι s) (Fork.condition s) :=
Cones.ext (Iso.refl _) <| by rintro ⟨j⟩ <;> simp
#align category_theory.limits.iso_of_ι CategoryTheory.Limits.isoOfι
def ofιCongr {P : C} {ι ι' : P ⟶ X} {w : ι ≫ f = 0} (h : ι = ι') :
KernelFork.ofι ι w ≅ KernelFork.ofι ι' (by rw [← h, w]) :=
Cones.ext (Iso.refl _)
#align category_theory.limits.of_ι_congr CategoryTheory.Limits.ofιCongr
def compNatIso {D : Type u'} [Category.{v} D] [HasZeroMorphisms D] (F : C ⥤ D) [F.IsEquivalence] :
parallelPair f 0 ⋙ F ≅ parallelPair (F.map f) 0 :=
let app (j :WalkingParallelPair) :
(parallelPair f 0 ⋙ F).obj j ≅ (parallelPair (F.map f) 0).obj j :=
match j with
| zero => Iso.refl _
| one => Iso.refl _
NatIso.ofComponents app <| by rintro ⟨i⟩ ⟨j⟩ <;> intro g <;> cases g <;> simp [app]
#align category_theory.limits.comp_nat_iso CategoryTheory.Limits.compNatIso
end
def KernelFork.IsLimit.lift' {s : KernelFork f} (hs : IsLimit s) {W : C} (k : W ⟶ X)
(h : k ≫ f = 0) : { l : W ⟶ s.pt // l ≫ Fork.ι s = k } :=
⟨hs.lift <| KernelFork.ofι _ h, hs.fac _ _⟩
#align category_theory.limits.kernel_fork.is_limit.lift' CategoryTheory.Limits.KernelFork.IsLimit.lift'
def isLimitAux (t : KernelFork f) (lift : ∀ s : KernelFork f, s.pt ⟶ t.pt)
(fac : ∀ s : KernelFork f, lift s ≫ t.ι = s.ι)
(uniq : ∀ (s : KernelFork f) (m : s.pt ⟶ t.pt) (_ : m ≫ t.ι = s.ι), m = lift s) : IsLimit t :=
{ lift
fac := fun s j => by
cases j
· exact fac s
· simp
uniq := fun s m w => uniq s m (w Limits.WalkingParallelPair.zero) }
#align category_theory.limits.is_limit_aux CategoryTheory.Limits.isLimitAux
def KernelFork.IsLimit.ofι {W : C} (g : W ⟶ X) (eq : g ≫ f = 0)
(lift : ∀ {W' : C} (g' : W' ⟶ X) (_ : g' ≫ f = 0), W' ⟶ W)
(fac : ∀ {W' : C} (g' : W' ⟶ X) (eq' : g' ≫ f = 0), lift g' eq' ≫ g = g')
(uniq :
∀ {W' : C} (g' : W' ⟶ X) (eq' : g' ≫ f = 0) (m : W' ⟶ W) (_ : m ≫ g = g'), m = lift g' eq') :
IsLimit (KernelFork.ofι g eq) :=
isLimitAux _ (fun s => lift s.ι s.condition) (fun s => fac s.ι s.condition) fun s =>
uniq s.ι s.condition
#align category_theory.limits.kernel_fork.is_limit.of_ι CategoryTheory.Limits.KernelFork.IsLimit.ofι
def KernelFork.IsLimit.ofι' {X Y K : C} {f : X ⟶ Y} (i : K ⟶ X) (w : i ≫ f = 0)
(h : ∀ {A : C} (k : A ⟶ X) (_ : k ≫ f = 0), { l : A ⟶ K // l ≫ i = k}) [hi : Mono i] :
IsLimit (KernelFork.ofι i w) :=
ofι _ _ (fun {A} k hk => (h k hk).1) (fun {A} k hk => (h k hk).2) (fun {A} k hk m hm => by
rw [← cancel_mono i, (h k hk).2, hm])
def isKernelCompMono {c : KernelFork f} (i : IsLimit c) {Z} (g : Y ⟶ Z) [hg : Mono g] {h : X ⟶ Z}
(hh : h = f ≫ g) : IsLimit (KernelFork.ofι c.ι (by simp [hh]) : KernelFork h) :=
Fork.IsLimit.mk' _ fun s =>
let s' : KernelFork f := Fork.ofι s.ι (by rw [← cancel_mono g]; simp [← hh, s.condition])
let l := KernelFork.IsLimit.lift' i s'.ι s'.condition
⟨l.1, l.2, fun hm => by
apply Fork.IsLimit.hom_ext i; rw [Fork.ι_ofι] at hm; rw [hm]; exact l.2.symm⟩
#align category_theory.limits.is_kernel_comp_mono CategoryTheory.Limits.isKernelCompMono
theorem isKernelCompMono_lift {c : KernelFork f} (i : IsLimit c) {Z} (g : Y ⟶ Z) [hg : Mono g]
{h : X ⟶ Z} (hh : h = f ≫ g) (s : KernelFork h) :
(isKernelCompMono i g hh).lift s = i.lift (Fork.ofι s.ι (by
rw [← cancel_mono g, Category.assoc, ← hh]
simp)) := rfl
#align category_theory.limits.is_kernel_comp_mono_lift CategoryTheory.Limits.isKernelCompMono_lift
def isKernelOfComp {W : C} (g : Y ⟶ W) (h : X ⟶ W) {c : KernelFork h} (i : IsLimit c)
(hf : c.ι ≫ f = 0) (hfg : f ≫ g = h) : IsLimit (KernelFork.ofι c.ι hf) :=
Fork.IsLimit.mk _ (fun s => i.lift (KernelFork.ofι s.ι (by simp [← hfg])))
(fun s => by simp only [KernelFork.ι_ofι, Fork.IsLimit.lift_ι]) fun s m h => by
apply Fork.IsLimit.hom_ext i; simpa using h
#align category_theory.limits.is_kernel_of_comp CategoryTheory.Limits.isKernelOfComp
def KernelFork.IsLimit.ofId {X Y : C} (f : X ⟶ Y) (hf : f = 0) :
IsLimit (KernelFork.ofι (𝟙 X) (show 𝟙 X ≫ f = 0 by rw [hf, comp_zero])) :=
KernelFork.IsLimit.ofι _ _ (fun x _ => x) (fun _ _ => Category.comp_id _)
(fun _ _ _ hb => by simp only [← hb, Category.comp_id])
def KernelFork.IsLimit.ofMonoOfIsZero {X Y : C} {f : X ⟶ Y} (c : KernelFork f)
(hf : Mono f) (h : IsZero c.pt) : IsLimit c :=
isLimitAux _ (fun s => 0) (fun s => by rw [zero_comp, ← cancel_mono f, zero_comp, s.condition])
(fun _ _ _ => h.eq_of_tgt _ _)
lemma KernelFork.IsLimit.isIso_ι {X Y : C} {f : X ⟶ Y} (c : KernelFork f)
(hc : IsLimit c) (hf : f = 0) : IsIso c.ι := by
let e : c.pt ≅ X := IsLimit.conePointUniqueUpToIso hc
(KernelFork.IsLimit.ofId (f : X ⟶ Y) hf)
have eq : e.inv ≫ c.ι = 𝟙 X := Fork.IsLimit.lift_ι hc
haveI : IsIso (e.inv ≫ c.ι) := by
rw [eq]
infer_instance
exact IsIso.of_isIso_comp_left e.inv c.ι
end
section
variable [HasKernel f]
abbrev kernel (f : X ⟶ Y) [HasKernel f] : C :=
equalizer f 0
#align category_theory.limits.kernel CategoryTheory.Limits.kernel
abbrev kernel.ι : kernel f ⟶ X :=
equalizer.ι f 0
#align category_theory.limits.kernel.ι CategoryTheory.Limits.kernel.ι
@[simp]
theorem equalizer_as_kernel : equalizer.ι f 0 = kernel.ι f := rfl
#align category_theory.limits.equalizer_as_kernel CategoryTheory.Limits.equalizer_as_kernel
@[reassoc (attr := simp)]
theorem kernel.condition : kernel.ι f ≫ f = 0 :=
KernelFork.condition _
#align category_theory.limits.kernel.condition CategoryTheory.Limits.kernel.condition
def kernelIsKernel : IsLimit (Fork.ofι (kernel.ι f) ((kernel.condition f).trans comp_zero.symm)) :=
IsLimit.ofIsoLimit (limit.isLimit _) (Fork.ext (Iso.refl _) (by aesop_cat))
#align category_theory.limits.kernel_is_kernel CategoryTheory.Limits.kernelIsKernel
abbrev kernel.lift {W : C} (k : W ⟶ X) (h : k ≫ f = 0) : W ⟶ kernel f :=
(kernelIsKernel f).lift (KernelFork.ofι k h)
#align category_theory.limits.kernel.lift CategoryTheory.Limits.kernel.lift
@[reassoc (attr := simp)]
theorem kernel.lift_ι {W : C} (k : W ⟶ X) (h : k ≫ f = 0) : kernel.lift f k h ≫ kernel.ι f = k :=
(kernelIsKernel f).fac (KernelFork.ofι k h) WalkingParallelPair.zero
#align category_theory.limits.kernel.lift_ι CategoryTheory.Limits.kernel.lift_ι
@[simp]
theorem kernel.lift_zero {W : C} {h} : kernel.lift f (0 : W ⟶ X) h = 0 := by
ext; simp
#align category_theory.limits.kernel.lift_zero CategoryTheory.Limits.kernel.lift_zero
instance kernel.lift_mono {W : C} (k : W ⟶ X) (h : k ≫ f = 0) [Mono k] : Mono (kernel.lift f k h) :=
⟨fun {Z} g g' w => by
replace w := w =≫ kernel.ι f
simp only [Category.assoc, kernel.lift_ι] at w
exact (cancel_mono k).1 w⟩
#align category_theory.limits.kernel.lift_mono CategoryTheory.Limits.kernel.lift_mono
def kernel.lift' {W : C} (k : W ⟶ X) (h : k ≫ f = 0) : { l : W ⟶ kernel f // l ≫ kernel.ι f = k } :=
⟨kernel.lift f k h, kernel.lift_ι _ _ _⟩
#align category_theory.limits.kernel.lift' CategoryTheory.Limits.kernel.lift'
abbrev kernel.map {X' Y' : C} (f' : X' ⟶ Y') [HasKernel f'] (p : X ⟶ X') (q : Y ⟶ Y')
(w : f ≫ q = p ≫ f') : kernel f ⟶ kernel f' :=
kernel.lift f' (kernel.ι f ≫ p) (by simp [← w])
#align category_theory.limits.kernel.map CategoryTheory.Limits.kernel.map
theorem kernel.lift_map {X Y Z X' Y' Z' : C} (f : X ⟶ Y) (g : Y ⟶ Z) [HasKernel g] (w : f ≫ g = 0)
(f' : X' ⟶ Y') (g' : Y' ⟶ Z') [HasKernel g'] (w' : f' ≫ g' = 0) (p : X ⟶ X') (q : Y ⟶ Y')
(r : Z ⟶ Z') (h₁ : f ≫ q = p ≫ f') (h₂ : g ≫ r = q ≫ g') :
kernel.lift g f w ≫ kernel.map g g' q r h₂ = p ≫ kernel.lift g' f' w' := by
ext; simp [h₁]
#align category_theory.limits.kernel.lift_map CategoryTheory.Limits.kernel.lift_map
@[simps]
def kernel.mapIso {X' Y' : C} (f' : X' ⟶ Y') [HasKernel f'] (p : X ≅ X') (q : Y ≅ Y')
(w : f ≫ q.hom = p.hom ≫ f') : kernel f ≅ kernel f' where
hom := kernel.map f f' p.hom q.hom w
inv :=
kernel.map f' f p.inv q.inv
(by
refine (cancel_mono q.hom).1 ?_
simp [w])
#align category_theory.limits.kernel.map_iso CategoryTheory.Limits.kernel.mapIso
instance kernel.ι_zero_isIso : IsIso (kernel.ι (0 : X ⟶ Y)) :=
equalizer.ι_of_self _
#align category_theory.limits.kernel.ι_zero_is_iso CategoryTheory.Limits.kernel.ι_zero_isIso
theorem eq_zero_of_epi_kernel [Epi (kernel.ι f)] : f = 0 :=
(cancel_epi (kernel.ι f)).1 (by simp)
#align category_theory.limits.eq_zero_of_epi_kernel CategoryTheory.Limits.eq_zero_of_epi_kernel
def kernelZeroIsoSource : kernel (0 : X ⟶ Y) ≅ X :=
equalizer.isoSourceOfSelf 0
#align category_theory.limits.kernel_zero_iso_source CategoryTheory.Limits.kernelZeroIsoSource
@[simp]
theorem kernelZeroIsoSource_hom : kernelZeroIsoSource.hom = kernel.ι (0 : X ⟶ Y) := rfl
#align category_theory.limits.kernel_zero_iso_source_hom CategoryTheory.Limits.kernelZeroIsoSource_hom
@[simp]
theorem kernelZeroIsoSource_inv :
kernelZeroIsoSource.inv = kernel.lift (0 : X ⟶ Y) (𝟙 X) (by simp) := by
ext
simp [kernelZeroIsoSource]
#align category_theory.limits.kernel_zero_iso_source_inv CategoryTheory.Limits.kernelZeroIsoSource_inv
def kernelIsoOfEq {f g : X ⟶ Y} [HasKernel f] [HasKernel g] (h : f = g) : kernel f ≅ kernel g :=
HasLimit.isoOfNatIso (by rw [h])
#align category_theory.limits.kernel_iso_of_eq CategoryTheory.Limits.kernelIsoOfEq
@[simp]
theorem kernelIsoOfEq_refl {h : f = f} : kernelIsoOfEq h = Iso.refl (kernel f) := by
ext
simp [kernelIsoOfEq]
#align category_theory.limits.kernel_iso_of_eq_refl CategoryTheory.Limits.kernelIsoOfEq_refl
@[reassoc (attr := simp)]
theorem kernelIsoOfEq_hom_comp_ι {f g : X ⟶ Y} [HasKernel f] [HasKernel g] (h : f = g) :
(kernelIsoOfEq h).hom ≫ kernel.ι g = kernel.ι f := by
cases h; simp
#align category_theory.limits.kernel_iso_of_eq_hom_comp_ι CategoryTheory.Limits.kernelIsoOfEq_hom_comp_ι
@[reassoc (attr := simp)]
theorem kernelIsoOfEq_inv_comp_ι {f g : X ⟶ Y} [HasKernel f] [HasKernel g] (h : f = g) :
(kernelIsoOfEq h).inv ≫ kernel.ι _ = kernel.ι _ := by
cases h; simp
#align category_theory.limits.kernel_iso_of_eq_inv_comp_ι CategoryTheory.Limits.kernelIsoOfEq_inv_comp_ι
@[reassoc (attr := simp)]
theorem lift_comp_kernelIsoOfEq_hom {Z} {f g : X ⟶ Y} [HasKernel f] [HasKernel g] (h : f = g)
(e : Z ⟶ X) (he) :
kernel.lift _ e he ≫ (kernelIsoOfEq h).hom = kernel.lift _ e (by simp [← h, he]) := by
cases h; simp
#align category_theory.limits.lift_comp_kernel_iso_of_eq_hom CategoryTheory.Limits.lift_comp_kernelIsoOfEq_hom
@[reassoc (attr := simp)]
theorem lift_comp_kernelIsoOfEq_inv {Z} {f g : X ⟶ Y} [HasKernel f] [HasKernel g] (h : f = g)
(e : Z ⟶ X) (he) :
kernel.lift _ e he ≫ (kernelIsoOfEq h).inv = kernel.lift _ e (by simp [h, he]) := by
cases h; simp
#align category_theory.limits.lift_comp_kernel_iso_of_eq_inv CategoryTheory.Limits.lift_comp_kernelIsoOfEq_inv
@[simp]
| Mathlib/CategoryTheory/Limits/Shapes/Kernels.lean | 414 | 416 | theorem kernelIsoOfEq_trans {f g h : X ⟶ Y} [HasKernel f] [HasKernel g] [HasKernel h] (w₁ : f = g)
(w₂ : g = h) : kernelIsoOfEq w₁ ≪≫ kernelIsoOfEq w₂ = kernelIsoOfEq (w₁.trans w₂) := by |
cases w₁; cases w₂; ext; simp [kernelIsoOfEq]
|
import Mathlib.Algebra.BigOperators.Group.Finset
import Mathlib.Data.List.MinMax
import Mathlib.Algebra.Tropical.Basic
import Mathlib.Order.ConditionallyCompleteLattice.Finset
#align_import algebra.tropical.big_operators from "leanprover-community/mathlib"@"d6fad0e5bf2d6f48da9175d25c3dc5706b3834ce"
variable {R S : Type*}
open Tropical Finset
theorem List.trop_sum [AddMonoid R] (l : List R) : trop l.sum = List.prod (l.map trop) := by
induction' l with hd tl IH
· simp
· simp [← IH]
#align list.trop_sum List.trop_sum
theorem Multiset.trop_sum [AddCommMonoid R] (s : Multiset R) :
trop s.sum = Multiset.prod (s.map trop) :=
Quotient.inductionOn s (by simpa using List.trop_sum)
#align multiset.trop_sum Multiset.trop_sum
theorem trop_sum [AddCommMonoid R] (s : Finset S) (f : S → R) :
trop (∑ i ∈ s, f i) = ∏ i ∈ s, trop (f i) := by
convert Multiset.trop_sum (s.val.map f)
simp only [Multiset.map_map, Function.comp_apply]
rfl
#align trop_sum trop_sum
theorem List.untrop_prod [AddMonoid R] (l : List (Tropical R)) :
untrop l.prod = List.sum (l.map untrop) := by
induction' l with hd tl IH
· simp
· simp [← IH]
#align list.untrop_prod List.untrop_prod
theorem Multiset.untrop_prod [AddCommMonoid R] (s : Multiset (Tropical R)) :
untrop s.prod = Multiset.sum (s.map untrop) :=
Quotient.inductionOn s (by simpa using List.untrop_prod)
#align multiset.untrop_prod Multiset.untrop_prod
theorem untrop_prod [AddCommMonoid R] (s : Finset S) (f : S → Tropical R) :
untrop (∏ i ∈ s, f i) = ∑ i ∈ s, untrop (f i) := by
convert Multiset.untrop_prod (s.val.map f)
simp only [Multiset.map_map, Function.comp_apply]
rfl
#align untrop_prod untrop_prod
-- Porting note: replaced `coe` with `WithTop.some` in statement
theorem List.trop_minimum [LinearOrder R] (l : List R) :
trop l.minimum = List.sum (l.map (trop ∘ WithTop.some)) := by
induction' l with hd tl IH
· simp
· simp [List.minimum_cons, ← IH]
#align list.trop_minimum List.trop_minimum
theorem Multiset.trop_inf [LinearOrder R] [OrderTop R] (s : Multiset R) :
trop s.inf = Multiset.sum (s.map trop) := by
induction' s using Multiset.induction with s x IH
· simp
· simp [← IH]
#align multiset.trop_inf Multiset.trop_inf
theorem Finset.trop_inf [LinearOrder R] [OrderTop R] (s : Finset S) (f : S → R) :
trop (s.inf f) = ∑ i ∈ s, trop (f i) := by
convert Multiset.trop_inf (s.val.map f)
simp only [Multiset.map_map, Function.comp_apply]
rfl
#align finset.trop_inf Finset.trop_inf
theorem trop_sInf_image [ConditionallyCompleteLinearOrder R] (s : Finset S) (f : S → WithTop R) :
trop (sInf (f '' s)) = ∑ i ∈ s, trop (f i) := by
rcases s.eq_empty_or_nonempty with (rfl | h)
· simp only [Set.image_empty, coe_empty, sum_empty, WithTop.sInf_empty, trop_top]
rw [← inf'_eq_csInf_image _ h, inf'_eq_inf, s.trop_inf]
#align trop_Inf_image trop_sInf_image
theorem trop_iInf [ConditionallyCompleteLinearOrder R] [Fintype S] (f : S → WithTop R) :
trop (⨅ i : S, f i) = ∑ i : S, trop (f i) := by
rw [iInf, ← Set.image_univ, ← coe_univ, trop_sInf_image]
#align trop_infi trop_iInf
theorem Multiset.untrop_sum [LinearOrder R] [OrderTop R] (s : Multiset (Tropical R)) :
untrop s.sum = Multiset.inf (s.map untrop) := by
induction' s using Multiset.induction with s x IH
· simp
· simp only [sum_cons, ge_iff_le, untrop_add, untrop_le_iff, map_cons, inf_cons, ← IH]
rfl
#align multiset.untrop_sum Multiset.untrop_sum
theorem Finset.untrop_sum' [LinearOrder R] [OrderTop R] (s : Finset S) (f : S → Tropical R) :
untrop (∑ i ∈ s, f i) = s.inf (untrop ∘ f) := by
convert Multiset.untrop_sum (s.val.map f)
simp only [Multiset.map_map, Function.comp_apply]
rfl
#align finset.untrop_sum' Finset.untrop_sum'
theorem untrop_sum_eq_sInf_image [ConditionallyCompleteLinearOrder R] (s : Finset S)
(f : S → Tropical (WithTop R)) : untrop (∑ i ∈ s, f i) = sInf (untrop ∘ f '' s) := by
rcases s.eq_empty_or_nonempty with (rfl | h)
· simp only [Set.image_empty, coe_empty, sum_empty, WithTop.sInf_empty, untrop_zero]
· rw [← inf'_eq_csInf_image _ h, inf'_eq_inf, Finset.untrop_sum']
#align untrop_sum_eq_Inf_image untrop_sum_eq_sInf_image
theorem untrop_sum [ConditionallyCompleteLinearOrder R] [Fintype S] (f : S → Tropical (WithTop R)) :
untrop (∑ i : S, f i) = ⨅ i : S, untrop (f i) := by
rw [iInf,← Set.image_univ,← coe_univ, untrop_sum_eq_sInf_image]
rfl
#align untrop_sum untrop_sum
| Mathlib/Algebra/Tropical/BigOperators.lean | 141 | 143 | theorem Finset.untrop_sum [ConditionallyCompleteLinearOrder R] (s : Finset S)
(f : S → Tropical (WithTop R)) : untrop (∑ i ∈ s, f i) = ⨅ i : s, untrop (f i) := by |
simpa [← _root_.untrop_sum] using (sum_attach _ _).symm
|
import Mathlib.Data.ENNReal.Inv
#align_import data.real.ennreal from "leanprover-community/mathlib"@"c14c8fcde993801fca8946b0d80131a1a81d1520"
open Set NNReal ENNReal
namespace ENNReal
section Real
variable {a b c d : ℝ≥0∞} {r p q : ℝ≥0}
theorem toReal_add (ha : a ≠ ∞) (hb : b ≠ ∞) : (a + b).toReal = a.toReal + b.toReal := by
lift a to ℝ≥0 using ha
lift b to ℝ≥0 using hb
rfl
#align ennreal.to_real_add ENNReal.toReal_add
theorem toReal_sub_of_le {a b : ℝ≥0∞} (h : b ≤ a) (ha : a ≠ ∞) :
(a - b).toReal = a.toReal - b.toReal := by
lift b to ℝ≥0 using ne_top_of_le_ne_top ha h
lift a to ℝ≥0 using ha
simp only [← ENNReal.coe_sub, ENNReal.coe_toReal, NNReal.coe_sub (ENNReal.coe_le_coe.mp h)]
#align ennreal.to_real_sub_of_le ENNReal.toReal_sub_of_le
theorem le_toReal_sub {a b : ℝ≥0∞} (hb : b ≠ ∞) : a.toReal - b.toReal ≤ (a - b).toReal := by
lift b to ℝ≥0 using hb
induction a
· simp
· simp only [← coe_sub, NNReal.sub_def, Real.coe_toNNReal', coe_toReal]
exact le_max_left _ _
#align ennreal.le_to_real_sub ENNReal.le_toReal_sub
theorem toReal_add_le : (a + b).toReal ≤ a.toReal + b.toReal :=
if ha : a = ∞ then by simp only [ha, top_add, top_toReal, zero_add, toReal_nonneg]
else
if hb : b = ∞ then by simp only [hb, add_top, top_toReal, add_zero, toReal_nonneg]
else le_of_eq (toReal_add ha hb)
#align ennreal.to_real_add_le ENNReal.toReal_add_le
theorem ofReal_add {p q : ℝ} (hp : 0 ≤ p) (hq : 0 ≤ q) :
ENNReal.ofReal (p + q) = ENNReal.ofReal p + ENNReal.ofReal q := by
rw [ENNReal.ofReal, ENNReal.ofReal, ENNReal.ofReal, ← coe_add, coe_inj,
Real.toNNReal_add hp hq]
#align ennreal.of_real_add ENNReal.ofReal_add
theorem ofReal_add_le {p q : ℝ} : ENNReal.ofReal (p + q) ≤ ENNReal.ofReal p + ENNReal.ofReal q :=
coe_le_coe.2 Real.toNNReal_add_le
#align ennreal.of_real_add_le ENNReal.ofReal_add_le
@[simp]
theorem toReal_le_toReal (ha : a ≠ ∞) (hb : b ≠ ∞) : a.toReal ≤ b.toReal ↔ a ≤ b := by
lift a to ℝ≥0 using ha
lift b to ℝ≥0 using hb
norm_cast
#align ennreal.to_real_le_to_real ENNReal.toReal_le_toReal
@[gcongr]
theorem toReal_mono (hb : b ≠ ∞) (h : a ≤ b) : a.toReal ≤ b.toReal :=
(toReal_le_toReal (ne_top_of_le_ne_top hb h) hb).2 h
#align ennreal.to_real_mono ENNReal.toReal_mono
-- Porting note (#10756): new lemma
theorem toReal_mono' (h : a ≤ b) (ht : b = ∞ → a = ∞) : a.toReal ≤ b.toReal := by
rcases eq_or_ne a ∞ with rfl | ha
· exact toReal_nonneg
· exact toReal_mono (mt ht ha) h
@[simp]
theorem toReal_lt_toReal (ha : a ≠ ∞) (hb : b ≠ ∞) : a.toReal < b.toReal ↔ a < b := by
lift a to ℝ≥0 using ha
lift b to ℝ≥0 using hb
norm_cast
#align ennreal.to_real_lt_to_real ENNReal.toReal_lt_toReal
@[gcongr]
theorem toReal_strict_mono (hb : b ≠ ∞) (h : a < b) : a.toReal < b.toReal :=
(toReal_lt_toReal h.ne_top hb).2 h
#align ennreal.to_real_strict_mono ENNReal.toReal_strict_mono
@[gcongr]
theorem toNNReal_mono (hb : b ≠ ∞) (h : a ≤ b) : a.toNNReal ≤ b.toNNReal :=
toReal_mono hb h
#align ennreal.to_nnreal_mono ENNReal.toNNReal_mono
-- Porting note (#10756): new lemma
theorem toReal_le_add' (hle : a ≤ b + c) (hb : b = ∞ → a = ∞) (hc : c = ∞ → a = ∞) :
a.toReal ≤ b.toReal + c.toReal := by
refine le_trans (toReal_mono' hle ?_) toReal_add_le
simpa only [add_eq_top, or_imp] using And.intro hb hc
-- Porting note (#10756): new lemma
theorem toReal_le_add (hle : a ≤ b + c) (hb : b ≠ ∞) (hc : c ≠ ∞) :
a.toReal ≤ b.toReal + c.toReal :=
toReal_le_add' hle (flip absurd hb) (flip absurd hc)
@[simp]
theorem toNNReal_le_toNNReal (ha : a ≠ ∞) (hb : b ≠ ∞) : a.toNNReal ≤ b.toNNReal ↔ a ≤ b :=
⟨fun h => by rwa [← coe_toNNReal ha, ← coe_toNNReal hb, coe_le_coe], toNNReal_mono hb⟩
#align ennreal.to_nnreal_le_to_nnreal ENNReal.toNNReal_le_toNNReal
theorem toNNReal_strict_mono (hb : b ≠ ∞) (h : a < b) : a.toNNReal < b.toNNReal := by
simpa [← ENNReal.coe_lt_coe, hb, h.ne_top]
#align ennreal.to_nnreal_strict_mono ENNReal.toNNReal_strict_mono
@[simp]
theorem toNNReal_lt_toNNReal (ha : a ≠ ∞) (hb : b ≠ ∞) : a.toNNReal < b.toNNReal ↔ a < b :=
⟨fun h => by rwa [← coe_toNNReal ha, ← coe_toNNReal hb, coe_lt_coe], toNNReal_strict_mono hb⟩
#align ennreal.to_nnreal_lt_to_nnreal ENNReal.toNNReal_lt_toNNReal
theorem toReal_max (hr : a ≠ ∞) (hp : b ≠ ∞) :
ENNReal.toReal (max a b) = max (ENNReal.toReal a) (ENNReal.toReal b) :=
(le_total a b).elim
(fun h => by simp only [h, (ENNReal.toReal_le_toReal hr hp).2 h, max_eq_right]) fun h => by
simp only [h, (ENNReal.toReal_le_toReal hp hr).2 h, max_eq_left]
#align ennreal.to_real_max ENNReal.toReal_max
theorem toReal_min {a b : ℝ≥0∞} (hr : a ≠ ∞) (hp : b ≠ ∞) :
ENNReal.toReal (min a b) = min (ENNReal.toReal a) (ENNReal.toReal b) :=
(le_total a b).elim (fun h => by simp only [h, (ENNReal.toReal_le_toReal hr hp).2 h, min_eq_left])
fun h => by simp only [h, (ENNReal.toReal_le_toReal hp hr).2 h, min_eq_right]
#align ennreal.to_real_min ENNReal.toReal_min
theorem toReal_sup {a b : ℝ≥0∞} : a ≠ ∞ → b ≠ ∞ → (a ⊔ b).toReal = a.toReal ⊔ b.toReal :=
toReal_max
#align ennreal.to_real_sup ENNReal.toReal_sup
theorem toReal_inf {a b : ℝ≥0∞} : a ≠ ∞ → b ≠ ∞ → (a ⊓ b).toReal = a.toReal ⊓ b.toReal :=
toReal_min
#align ennreal.to_real_inf ENNReal.toReal_inf
theorem toNNReal_pos_iff : 0 < a.toNNReal ↔ 0 < a ∧ a < ∞ := by
induction a <;> simp
#align ennreal.to_nnreal_pos_iff ENNReal.toNNReal_pos_iff
theorem toNNReal_pos {a : ℝ≥0∞} (ha₀ : a ≠ 0) (ha_top : a ≠ ∞) : 0 < a.toNNReal :=
toNNReal_pos_iff.mpr ⟨bot_lt_iff_ne_bot.mpr ha₀, lt_top_iff_ne_top.mpr ha_top⟩
#align ennreal.to_nnreal_pos ENNReal.toNNReal_pos
theorem toReal_pos_iff : 0 < a.toReal ↔ 0 < a ∧ a < ∞ :=
NNReal.coe_pos.trans toNNReal_pos_iff
#align ennreal.to_real_pos_iff ENNReal.toReal_pos_iff
theorem toReal_pos {a : ℝ≥0∞} (ha₀ : a ≠ 0) (ha_top : a ≠ ∞) : 0 < a.toReal :=
toReal_pos_iff.mpr ⟨bot_lt_iff_ne_bot.mpr ha₀, lt_top_iff_ne_top.mpr ha_top⟩
#align ennreal.to_real_pos ENNReal.toReal_pos
@[gcongr]
theorem ofReal_le_ofReal {p q : ℝ} (h : p ≤ q) : ENNReal.ofReal p ≤ ENNReal.ofReal q := by
simp [ENNReal.ofReal, Real.toNNReal_le_toNNReal h]
#align ennreal.of_real_le_of_real ENNReal.ofReal_le_ofReal
theorem ofReal_le_of_le_toReal {a : ℝ} {b : ℝ≥0∞} (h : a ≤ ENNReal.toReal b) :
ENNReal.ofReal a ≤ b :=
(ofReal_le_ofReal h).trans ofReal_toReal_le
#align ennreal.of_real_le_of_le_to_real ENNReal.ofReal_le_of_le_toReal
@[simp]
theorem ofReal_le_ofReal_iff {p q : ℝ} (h : 0 ≤ q) :
ENNReal.ofReal p ≤ ENNReal.ofReal q ↔ p ≤ q := by
rw [ENNReal.ofReal, ENNReal.ofReal, coe_le_coe, Real.toNNReal_le_toNNReal_iff h]
#align ennreal.of_real_le_of_real_iff ENNReal.ofReal_le_ofReal_iff
lemma ofReal_le_ofReal_iff' {p q : ℝ} : ENNReal.ofReal p ≤ .ofReal q ↔ p ≤ q ∨ p ≤ 0 :=
coe_le_coe.trans Real.toNNReal_le_toNNReal_iff'
lemma ofReal_lt_ofReal_iff' {p q : ℝ} : ENNReal.ofReal p < .ofReal q ↔ p < q ∧ 0 < q :=
coe_lt_coe.trans Real.toNNReal_lt_toNNReal_iff'
@[simp]
theorem ofReal_eq_ofReal_iff {p q : ℝ} (hp : 0 ≤ p) (hq : 0 ≤ q) :
ENNReal.ofReal p = ENNReal.ofReal q ↔ p = q := by
rw [ENNReal.ofReal, ENNReal.ofReal, coe_inj, Real.toNNReal_eq_toNNReal_iff hp hq]
#align ennreal.of_real_eq_of_real_iff ENNReal.ofReal_eq_ofReal_iff
@[simp]
theorem ofReal_lt_ofReal_iff {p q : ℝ} (h : 0 < q) :
ENNReal.ofReal p < ENNReal.ofReal q ↔ p < q := by
rw [ENNReal.ofReal, ENNReal.ofReal, coe_lt_coe, Real.toNNReal_lt_toNNReal_iff h]
#align ennreal.of_real_lt_of_real_iff ENNReal.ofReal_lt_ofReal_iff
theorem ofReal_lt_ofReal_iff_of_nonneg {p q : ℝ} (hp : 0 ≤ p) :
ENNReal.ofReal p < ENNReal.ofReal q ↔ p < q := by
rw [ENNReal.ofReal, ENNReal.ofReal, coe_lt_coe, Real.toNNReal_lt_toNNReal_iff_of_nonneg hp]
#align ennreal.of_real_lt_of_real_iff_of_nonneg ENNReal.ofReal_lt_ofReal_iff_of_nonneg
@[simp]
theorem ofReal_pos {p : ℝ} : 0 < ENNReal.ofReal p ↔ 0 < p := by simp [ENNReal.ofReal]
#align ennreal.of_real_pos ENNReal.ofReal_pos
@[simp]
| Mathlib/Data/ENNReal/Real.lean | 222 | 222 | theorem ofReal_eq_zero {p : ℝ} : ENNReal.ofReal p = 0 ↔ p ≤ 0 := by | simp [ENNReal.ofReal]
|
import Mathlib.Algebra.GeomSum
import Mathlib.Algebra.Polynomial.Roots
import Mathlib.GroupTheory.SpecificGroups.Cyclic
#align_import ring_theory.integral_domain from "leanprover-community/mathlib"@"6e70e0d419bf686784937d64ed4bfde866ff229e"
section
open Finset Polynomial Function Nat
variable {R : Type*} {G : Type*}
variable [CommRing R] [IsDomain R] [Group G]
-- Porting note: Finset doesn't seem to have `{g ∈ univ | g^n = g₀}` notation anymore,
-- so we have to use `Finset.filter` instead
theorem card_nthRoots_subgroup_units [Fintype G] [DecidableEq G] (f : G →* R) (hf : Injective f)
{n : ℕ} (hn : 0 < n) (g₀ : G) :
Finset.card (Finset.univ.filter (fun g ↦ g^n = g₀)) ≤ Multiset.card (nthRoots n (f g₀)) := by
haveI : DecidableEq R := Classical.decEq _
refine le_trans ?_ (nthRoots n (f g₀)).toFinset_card_le
apply card_le_card_of_inj_on f
· intro g hg
rw [mem_filter] at hg
rw [Multiset.mem_toFinset, mem_nthRoots hn, ← f.map_pow, hg.2]
· intros
apply hf
assumption
#align card_nth_roots_subgroup_units card_nthRoots_subgroup_units
theorem isCyclic_of_subgroup_isDomain [Finite G] (f : G →* R) (hf : Injective f) : IsCyclic G := by
classical
cases nonempty_fintype G
apply isCyclic_of_card_pow_eq_one_le
intro n hn
exact le_trans (card_nthRoots_subgroup_units f hf hn 1) (card_nthRoots n (f 1))
#align is_cyclic_of_subgroup_is_domain isCyclic_of_subgroup_isDomain
instance [Finite Rˣ] : IsCyclic Rˣ :=
isCyclic_of_subgroup_isDomain (Units.coeHom R) <| Units.ext
section
variable (S : Subgroup Rˣ) [Finite S]
instance subgroup_units_cyclic : IsCyclic S := by
-- Porting note: the original proof used a `coe`, but I was not able to get it to work.
apply isCyclic_of_subgroup_isDomain (R := R) (G := S) _ _
· exact MonoidHom.mk (OneHom.mk (fun s => ↑s.val) rfl) (by simp)
· exact Units.ext.comp Subtype.val_injective
#align subgroup_units_cyclic subgroup_units_cyclic
end
section EuclideanDivision
namespace Polynomial
open Polynomial
variable (K : Type) [Field K] [Algebra R[X] K] [IsFractionRing R[X] K]
| Mathlib/RingTheory/IntegralDomain.lean | 174 | 185 | theorem div_eq_quo_add_rem_div (f : R[X]) {g : R[X]} (hg : g.Monic) :
∃ q r : R[X], r.degree < g.degree ∧
(algebraMap R[X] K f) / (algebraMap R[X] K g) =
algebraMap R[X] K q + (algebraMap R[X] K r) / (algebraMap R[X] K g) := by |
refine ⟨f /ₘ g, f %ₘ g, ?_, ?_⟩
· exact degree_modByMonic_lt _ hg
· have hg' : algebraMap R[X] K g ≠ 0 :=
-- Porting note: the proof was `by exact_mod_cast Monic.ne_zero hg`
(map_ne_zero_iff _ (IsFractionRing.injective R[X] K)).mpr (Monic.ne_zero hg)
field_simp [hg']
-- Porting note: `norm_cast` was here, but does nothing.
rw [add_comm, mul_comm, ← map_mul, ← map_add, modByMonic_add_div f hg]
|
import Mathlib.Order.Filter.Bases
import Mathlib.Topology.Algebra.Module.Basic
#align_import topology.algebra.filter_basis from "leanprover-community/mathlib"@"f2ce6086713c78a7f880485f7917ea547a215982"
open Filter Set TopologicalSpace Function
open Topology Filter Pointwise
universe u
class GroupFilterBasis (G : Type u) [Group G] extends FilterBasis G where
one' : ∀ {U}, U ∈ sets → (1 : G) ∈ U
mul' : ∀ {U}, U ∈ sets → ∃ V ∈ sets, V * V ⊆ U
inv' : ∀ {U}, U ∈ sets → ∃ V ∈ sets, V ⊆ (fun x ↦ x⁻¹) ⁻¹' U
conj' : ∀ x₀, ∀ {U}, U ∈ sets → ∃ V ∈ sets, V ⊆ (fun x ↦ x₀ * x * x₀⁻¹) ⁻¹' U
#align group_filter_basis GroupFilterBasis
class AddGroupFilterBasis (A : Type u) [AddGroup A] extends FilterBasis A where
zero' : ∀ {U}, U ∈ sets → (0 : A) ∈ U
add' : ∀ {U}, U ∈ sets → ∃ V ∈ sets, V + V ⊆ U
neg' : ∀ {U}, U ∈ sets → ∃ V ∈ sets, V ⊆ (fun x ↦ -x) ⁻¹' U
conj' : ∀ x₀, ∀ {U}, U ∈ sets → ∃ V ∈ sets, V ⊆ (fun x ↦ x₀ + x + -x₀) ⁻¹' U
#align add_group_filter_basis AddGroupFilterBasis
attribute [to_additive existing] GroupFilterBasis GroupFilterBasis.conj'
GroupFilterBasis.toFilterBasis
@[to_additive "`AddGroupFilterBasis` constructor in the additive commutative group case."]
def groupFilterBasisOfComm {G : Type*} [CommGroup G] (sets : Set (Set G))
(nonempty : sets.Nonempty) (inter_sets : ∀ x y, x ∈ sets → y ∈ sets → ∃ z ∈ sets, z ⊆ x ∩ y)
(one : ∀ U ∈ sets, (1 : G) ∈ U) (mul : ∀ U ∈ sets, ∃ V ∈ sets, V * V ⊆ U)
(inv : ∀ U ∈ sets, ∃ V ∈ sets, V ⊆ (fun x ↦ x⁻¹) ⁻¹' U) : GroupFilterBasis G :=
{ sets := sets
nonempty := nonempty
inter_sets := inter_sets _ _
one' := one _
mul' := mul _
inv' := inv _
conj' := fun x U U_in ↦ ⟨U, U_in, by simp only [mul_inv_cancel_comm, preimage_id']; rfl⟩ }
#align group_filter_basis_of_comm groupFilterBasisOfComm
#align add_group_filter_basis_of_comm addGroupFilterBasisOfComm
namespace GroupFilterBasis
variable {G : Type u} [Group G] {B : GroupFilterBasis G}
@[to_additive]
instance : Membership (Set G) (GroupFilterBasis G) :=
⟨fun s f ↦ s ∈ f.sets⟩
@[to_additive]
theorem one {U : Set G} : U ∈ B → (1 : G) ∈ U :=
GroupFilterBasis.one'
#align group_filter_basis.one GroupFilterBasis.one
#align add_group_filter_basis.zero AddGroupFilterBasis.zero
@[to_additive]
theorem mul {U : Set G} : U ∈ B → ∃ V ∈ B, V * V ⊆ U :=
GroupFilterBasis.mul'
#align group_filter_basis.mul GroupFilterBasis.mul
#align add_group_filter_basis.add AddGroupFilterBasis.add
@[to_additive]
theorem inv {U : Set G} : U ∈ B → ∃ V ∈ B, V ⊆ (fun x ↦ x⁻¹) ⁻¹' U :=
GroupFilterBasis.inv'
#align group_filter_basis.inv GroupFilterBasis.inv
#align add_group_filter_basis.neg AddGroupFilterBasis.neg
@[to_additive]
theorem conj : ∀ x₀, ∀ {U}, U ∈ B → ∃ V ∈ B, V ⊆ (fun x ↦ x₀ * x * x₀⁻¹) ⁻¹' U :=
GroupFilterBasis.conj'
#align group_filter_basis.conj GroupFilterBasis.conj
#align add_group_filter_basis.conj AddGroupFilterBasis.conj
@[to_additive "The trivial additive group filter basis consists of `{0}` only. The associated
topology is discrete."]
instance : Inhabited (GroupFilterBasis G) where
default := {
sets := {{1}}
nonempty := singleton_nonempty _
inter_sets := by simp
one' := by simp
mul' := by simp
inv' := by simp
conj' := by simp }
@[to_additive]
theorem subset_mul_self (B : GroupFilterBasis G) {U : Set G} (h : U ∈ B) : U ⊆ U * U :=
fun x x_in ↦ ⟨1, one h, x, x_in, one_mul x⟩
#align group_filter_basis.prod_subset_self GroupFilterBasis.subset_mul_self
#align add_group_filter_basis.sum_subset_self AddGroupFilterBasis.subset_add_self
@[to_additive "The neighborhood function of an `AddGroupFilterBasis`."]
def N (B : GroupFilterBasis G) : G → Filter G :=
fun x ↦ map (fun y ↦ x * y) B.toFilterBasis.filter
set_option linter.uppercaseLean3 false in
#align group_filter_basis.N GroupFilterBasis.N
set_option linter.uppercaseLean3 false in
#align add_group_filter_basis.N AddGroupFilterBasis.N
@[to_additive (attr := simp)]
theorem N_one (B : GroupFilterBasis G) : B.N 1 = B.toFilterBasis.filter := by
simp only [N, one_mul, map_id']
set_option linter.uppercaseLean3 false in
#align group_filter_basis.N_one GroupFilterBasis.N_one
set_option linter.uppercaseLean3 false in
#align add_group_filter_basis.N_zero AddGroupFilterBasis.N_zero
@[to_additive]
protected theorem hasBasis (B : GroupFilterBasis G) (x : G) :
HasBasis (B.N x) (fun V : Set G ↦ V ∈ B) fun V ↦ (fun y ↦ x * y) '' V :=
HasBasis.map (fun y ↦ x * y) toFilterBasis.hasBasis
#align group_filter_basis.has_basis GroupFilterBasis.hasBasis
#align add_group_filter_basis.has_basis AddGroupFilterBasis.hasBasis
@[to_additive "The topological space structure coming from an additive group filter basis."]
def topology (B : GroupFilterBasis G) : TopologicalSpace G :=
TopologicalSpace.mkOfNhds B.N
#align group_filter_basis.topology GroupFilterBasis.topology
#align add_group_filter_basis.topology AddGroupFilterBasis.topology
@[to_additive]
theorem nhds_eq (B : GroupFilterBasis G) {x₀ : G} : @nhds G B.topology x₀ = B.N x₀ := by
apply TopologicalSpace.nhds_mkOfNhds_of_hasBasis (fun x ↦ (FilterBasis.hasBasis _).map _)
· intro a U U_in
exact ⟨1, B.one U_in, mul_one a⟩
· intro a U U_in
rcases GroupFilterBasis.mul U_in with ⟨V, V_in, hVU⟩
filter_upwards [image_mem_map (B.mem_filter_of_mem V_in)]
rintro _ ⟨x, hx, rfl⟩
calc
a • U ⊇ a • (V * V) := smul_set_mono hVU
_ ⊇ a • x • V := smul_set_mono <| smul_set_subset_smul hx
_ = (a * x) • V := smul_smul ..
_ ∈ (a * x) • B.filter := smul_set_mem_smul_filter <| B.mem_filter_of_mem V_in
#align group_filter_basis.nhds_eq GroupFilterBasis.nhds_eq
#align add_group_filter_basis.nhds_eq AddGroupFilterBasis.nhds_eq
@[to_additive]
theorem nhds_one_eq (B : GroupFilterBasis G) :
@nhds G B.topology (1 : G) = B.toFilterBasis.filter := by
rw [B.nhds_eq]
simp only [N, one_mul]
exact map_id
#align group_filter_basis.nhds_one_eq GroupFilterBasis.nhds_one_eq
#align add_group_filter_basis.nhds_zero_eq AddGroupFilterBasis.nhds_zero_eq
@[to_additive]
theorem nhds_hasBasis (B : GroupFilterBasis G) (x₀ : G) :
HasBasis (@nhds G B.topology x₀) (fun V : Set G ↦ V ∈ B) fun V ↦ (fun y ↦ x₀ * y) '' V := by
rw [B.nhds_eq]
apply B.hasBasis
#align group_filter_basis.nhds_has_basis GroupFilterBasis.nhds_hasBasis
#align add_group_filter_basis.nhds_has_basis AddGroupFilterBasis.nhds_hasBasis
@[to_additive]
| Mathlib/Topology/Algebra/FilterBasis.lean | 205 | 208 | theorem nhds_one_hasBasis (B : GroupFilterBasis G) :
HasBasis (@nhds G B.topology 1) (fun V : Set G ↦ V ∈ B) id := by |
rw [B.nhds_one_eq]
exact B.toFilterBasis.hasBasis
|
import Mathlib.Topology.Compactness.Compact
open Set Filter Topology TopologicalSpace Classical
variable {X : Type*} {Y : Type*} {ι : Type*}
variable [TopologicalSpace X] [TopologicalSpace Y] {s t : Set X}
instance [WeaklyLocallyCompactSpace X] [WeaklyLocallyCompactSpace Y] :
WeaklyLocallyCompactSpace (X × Y) where
exists_compact_mem_nhds x :=
let ⟨s₁, hc₁, h₁⟩ := exists_compact_mem_nhds x.1
let ⟨s₂, hc₂, h₂⟩ := exists_compact_mem_nhds x.2
⟨s₁ ×ˢ s₂, hc₁.prod hc₂, prod_mem_nhds h₁ h₂⟩
instance {ι : Type*} [Finite ι] {X : ι → Type*} [(i : ι) → TopologicalSpace (X i)]
[(i : ι) → WeaklyLocallyCompactSpace (X i)] :
WeaklyLocallyCompactSpace ((i : ι) → X i) where
exists_compact_mem_nhds := fun f ↦ by
choose s hsc hs using fun i ↦ exists_compact_mem_nhds (f i)
exact ⟨pi univ s, isCompact_univ_pi hsc, set_pi_mem_nhds univ.toFinite fun i _ ↦ hs i⟩
instance (priority := 100) [CompactSpace X] : WeaklyLocallyCompactSpace X where
exists_compact_mem_nhds _ := ⟨univ, isCompact_univ, univ_mem⟩
theorem exists_compact_superset [WeaklyLocallyCompactSpace X] {K : Set X} (hK : IsCompact K) :
∃ K', IsCompact K' ∧ K ⊆ interior K' := by
choose s hc hmem using fun x : X ↦ exists_compact_mem_nhds x
rcases hK.elim_nhds_subcover _ fun x _ ↦ interior_mem_nhds.2 (hmem x) with ⟨I, -, hIK⟩
refine ⟨⋃ x ∈ I, s x, I.isCompact_biUnion fun _ _ ↦ hc _, hIK.trans ?_⟩
exact iUnion₂_subset fun x hx ↦ interior_mono <| subset_iUnion₂ (s := fun x _ ↦ s x) x hx
#align exists_compact_superset exists_compact_superset
theorem disjoint_nhds_cocompact [WeaklyLocallyCompactSpace X] (x : X) :
Disjoint (𝓝 x) (cocompact X) :=
let ⟨_, hc, hx⟩ := exists_compact_mem_nhds x
disjoint_of_disjoint_of_mem disjoint_compl_right hx hc.compl_mem_cocompact
theorem compact_basis_nhds [LocallyCompactSpace X] (x : X) :
(𝓝 x).HasBasis (fun s => s ∈ 𝓝 x ∧ IsCompact s) fun s => s :=
hasBasis_self.2 <| by simpa only [and_comm] using LocallyCompactSpace.local_compact_nhds x
#align compact_basis_nhds compact_basis_nhds
theorem local_compact_nhds [LocallyCompactSpace X] {x : X} {n : Set X} (h : n ∈ 𝓝 x) :
∃ s ∈ 𝓝 x, s ⊆ n ∧ IsCompact s :=
LocallyCompactSpace.local_compact_nhds _ _ h
#align local_compact_nhds local_compact_nhds
theorem LocallyCompactSpace.of_hasBasis {ι : X → Type*} {p : ∀ x, ι x → Prop}
{s : ∀ x, ι x → Set X} (h : ∀ x, (𝓝 x).HasBasis (p x) (s x))
(hc : ∀ x i, p x i → IsCompact (s x i)) : LocallyCompactSpace X :=
⟨fun x _t ht =>
let ⟨i, hp, ht⟩ := (h x).mem_iff.1 ht
⟨s x i, (h x).mem_of_mem hp, ht, hc x i hp⟩⟩
#align locally_compact_space_of_has_basis LocallyCompactSpace.of_hasBasis
@[deprecated (since := "2023-12-29")]
alias locallyCompactSpace_of_hasBasis := LocallyCompactSpace.of_hasBasis
instance Prod.locallyCompactSpace (X : Type*) (Y : Type*) [TopologicalSpace X]
[TopologicalSpace Y] [LocallyCompactSpace X] [LocallyCompactSpace Y] :
LocallyCompactSpace (X × Y) :=
have := fun x : X × Y => (compact_basis_nhds x.1).prod_nhds' (compact_basis_nhds x.2)
.of_hasBasis this fun _ _ ⟨⟨_, h₁⟩, _, h₂⟩ => h₁.prod h₂
#align prod.locally_compact_space Prod.locallyCompactSpace
instance (priority := 900) [LocallyCompactSpace X] : LocallyCompactPair X Y where
exists_mem_nhds_isCompact_mapsTo hf hs :=
let ⟨K, hKx, hKs, hKc⟩ := local_compact_nhds (hf.continuousAt hs); ⟨K, hKx, hKc, hKs⟩
instance (priority := 100) [LocallyCompactSpace X] : WeaklyLocallyCompactSpace X where
exists_compact_mem_nhds (x : X) :=
let ⟨K, hx, _, hKc⟩ := local_compact_nhds (x := x) univ_mem; ⟨K, hKc, hx⟩
| Mathlib/Topology/Compactness/LocallyCompact.lean | 141 | 144 | theorem exists_compact_subset [LocallyCompactSpace X] {x : X} {U : Set X} (hU : IsOpen U)
(hx : x ∈ U) : ∃ K : Set X, IsCompact K ∧ x ∈ interior K ∧ K ⊆ U := by |
rcases LocallyCompactSpace.local_compact_nhds x U (hU.mem_nhds hx) with ⟨K, h1K, h2K, h3K⟩
exact ⟨K, h3K, mem_interior_iff_mem_nhds.2 h1K, h2K⟩
|
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
| Mathlib/Algebra/Polynomial/Degree/Definitions.lean | 171 | 172 | 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]
|
import Mathlib.LinearAlgebra.FiniteDimensional
import Mathlib.MeasureTheory.Group.Pointwise
import Mathlib.MeasureTheory.Measure.Lebesgue.Basic
import Mathlib.MeasureTheory.Measure.Haar.Basic
import Mathlib.MeasureTheory.Measure.Doubling
import Mathlib.MeasureTheory.Constructions.BorelSpace.Metric
#align_import measure_theory.measure.lebesgue.eq_haar from "leanprover-community/mathlib"@"fd5edc43dc4f10b85abfe544b88f82cf13c5f844"
assert_not_exists MeasureTheory.integral
open TopologicalSpace Set Filter Metric Bornology
open scoped ENNReal Pointwise Topology NNReal
def TopologicalSpace.PositiveCompacts.Icc01 : PositiveCompacts ℝ where
carrier := Icc 0 1
isCompact' := isCompact_Icc
interior_nonempty' := by simp_rw [interior_Icc, nonempty_Ioo, zero_lt_one]
#align topological_space.positive_compacts.Icc01 TopologicalSpace.PositiveCompacts.Icc01
universe u
def TopologicalSpace.PositiveCompacts.piIcc01 (ι : Type*) [Finite ι] :
PositiveCompacts (ι → ℝ) where
carrier := pi univ fun _ => Icc 0 1
isCompact' := isCompact_univ_pi fun _ => isCompact_Icc
interior_nonempty' := by
simp only [interior_pi_set, Set.toFinite, interior_Icc, univ_pi_nonempty_iff, nonempty_Ioo,
imp_true_iff, zero_lt_one]
#align topological_space.positive_compacts.pi_Icc01 TopologicalSpace.PositiveCompacts.piIcc01
theorem Basis.parallelepiped_basisFun (ι : Type*) [Fintype ι] :
(Pi.basisFun ℝ ι).parallelepiped = TopologicalSpace.PositiveCompacts.piIcc01 ι :=
SetLike.coe_injective <| by
refine Eq.trans ?_ ((uIcc_of_le ?_).trans (Set.pi_univ_Icc _ _).symm)
· classical convert parallelepiped_single (ι := ι) 1
· exact zero_le_one
#align basis.parallelepiped_basis_fun Basis.parallelepiped_basisFun
theorem Basis.parallelepiped_eq_map {ι E : Type*} [Fintype ι] [NormedAddCommGroup E]
[NormedSpace ℝ E] (b : Basis ι ℝ E) :
b.parallelepiped = (PositiveCompacts.piIcc01 ι).map b.equivFun.symm
b.equivFunL.symm.continuous b.equivFunL.symm.isOpenMap := by
classical
rw [← Basis.parallelepiped_basisFun, ← Basis.parallelepiped_map]
congr with x
simp
open MeasureTheory MeasureTheory.Measure
theorem Basis.map_addHaar {ι E F : Type*} [Fintype ι] [NormedAddCommGroup E] [NormedAddCommGroup F]
[NormedSpace ℝ E] [NormedSpace ℝ F] [MeasurableSpace E] [MeasurableSpace F] [BorelSpace E]
[BorelSpace F] [SecondCountableTopology F] [SigmaCompactSpace F]
(b : Basis ι ℝ E) (f : E ≃L[ℝ] F) :
map f b.addHaar = (b.map f.toLinearEquiv).addHaar := by
have : IsAddHaarMeasure (map f b.addHaar) :=
AddEquiv.isAddHaarMeasure_map b.addHaar f.toAddEquiv f.continuous f.symm.continuous
rw [eq_comm, Basis.addHaar_eq_iff, Measure.map_apply f.continuous.measurable
(PositiveCompacts.isCompact _).measurableSet, Basis.coe_parallelepiped, Basis.coe_map]
erw [← image_parallelepiped, f.toEquiv.preimage_image, addHaar_self]
namespace MeasureTheory
open Measure TopologicalSpace.PositiveCompacts FiniteDimensional
theorem addHaarMeasure_eq_volume : addHaarMeasure Icc01 = volume := by
convert (addHaarMeasure_unique volume Icc01).symm; simp [Icc01]
#align measure_theory.add_haar_measure_eq_volume MeasureTheory.addHaarMeasure_eq_volume
theorem addHaarMeasure_eq_volume_pi (ι : Type*) [Fintype ι] :
addHaarMeasure (piIcc01 ι) = volume := by
convert (addHaarMeasure_unique volume (piIcc01 ι)).symm
simp only [piIcc01, volume_pi_pi fun _ => Icc (0 : ℝ) 1, PositiveCompacts.coe_mk,
Compacts.coe_mk, Finset.prod_const_one, ENNReal.ofReal_one, Real.volume_Icc, one_smul, sub_zero]
#align measure_theory.add_haar_measure_eq_volume_pi MeasureTheory.addHaarMeasure_eq_volume_pi
-- Porting note (#11215): TODO: remove this instance?
instance isAddHaarMeasure_volume_pi (ι : Type*) [Fintype ι] :
IsAddHaarMeasure (volume : Measure (ι → ℝ)) :=
inferInstance
#align measure_theory.is_add_haar_measure_volume_pi MeasureTheory.isAddHaarMeasure_volume_pi
namespace Measure
theorem addHaar_eq_zero_of_disjoint_translates_aux {E : Type*} [NormedAddCommGroup E]
[NormedSpace ℝ E] [MeasurableSpace E] [BorelSpace E] [FiniteDimensional ℝ E] (μ : Measure E)
[IsAddHaarMeasure μ] {s : Set E} (u : ℕ → E) (sb : IsBounded s) (hu : IsBounded (range u))
(hs : Pairwise (Disjoint on fun n => {u n} + s)) (h's : MeasurableSet s) : μ s = 0 := by
by_contra h
apply lt_irrefl ∞
calc
∞ = ∑' _ : ℕ, μ s := (ENNReal.tsum_const_eq_top_of_ne_zero h).symm
_ = ∑' n : ℕ, μ ({u n} + s) := by
congr 1; ext1 n; simp only [image_add_left, measure_preimage_add, singleton_add]
_ = μ (⋃ n, {u n} + s) := Eq.symm <| measure_iUnion hs fun n => by
simpa only [image_add_left, singleton_add] using measurable_id.const_add _ h's
_ = μ (range u + s) := by rw [← iUnion_add, iUnion_singleton_eq_range]
_ < ∞ := (hu.add sb).measure_lt_top
#align measure_theory.measure.add_haar_eq_zero_of_disjoint_translates_aux MeasureTheory.Measure.addHaar_eq_zero_of_disjoint_translates_aux
theorem addHaar_eq_zero_of_disjoint_translates {E : Type*} [NormedAddCommGroup E]
[NormedSpace ℝ E] [MeasurableSpace E] [BorelSpace E] [FiniteDimensional ℝ E] (μ : Measure E)
[IsAddHaarMeasure μ] {s : Set E} (u : ℕ → E) (hu : IsBounded (range u))
(hs : Pairwise (Disjoint on fun n => {u n} + s)) (h's : MeasurableSet s) : μ s = 0 := by
suffices H : ∀ R, μ (s ∩ closedBall 0 R) = 0 by
apply le_antisymm _ (zero_le _)
calc
μ s ≤ ∑' n : ℕ, μ (s ∩ closedBall 0 n) := by
conv_lhs => rw [← iUnion_inter_closedBall_nat s 0]
exact measure_iUnion_le _
_ = 0 := by simp only [H, tsum_zero]
intro R
apply addHaar_eq_zero_of_disjoint_translates_aux μ u
(isBounded_closedBall.subset inter_subset_right) hu _ (h's.inter measurableSet_closedBall)
refine pairwise_disjoint_mono hs fun n => ?_
exact add_subset_add Subset.rfl inter_subset_left
#align measure_theory.measure.add_haar_eq_zero_of_disjoint_translates MeasureTheory.Measure.addHaar_eq_zero_of_disjoint_translates
theorem addHaar_submodule {E : Type*} [NormedAddCommGroup E] [NormedSpace ℝ E] [MeasurableSpace E]
[BorelSpace E] [FiniteDimensional ℝ E] (μ : Measure E) [IsAddHaarMeasure μ] (s : Submodule ℝ E)
(hs : s ≠ ⊤) : μ s = 0 := by
obtain ⟨x, hx⟩ : ∃ x, x ∉ s := by
simpa only [Submodule.eq_top_iff', not_exists, Ne, not_forall] using hs
obtain ⟨c, cpos, cone⟩ : ∃ c : ℝ, 0 < c ∧ c < 1 := ⟨1 / 2, by norm_num, by norm_num⟩
have A : IsBounded (range fun n : ℕ => c ^ n • x) :=
have : Tendsto (fun n : ℕ => c ^ n • x) atTop (𝓝 ((0 : ℝ) • x)) :=
(tendsto_pow_atTop_nhds_zero_of_lt_one cpos.le cone).smul_const x
isBounded_range_of_tendsto _ this
apply addHaar_eq_zero_of_disjoint_translates μ _ A _
(Submodule.closed_of_finiteDimensional s).measurableSet
intro m n hmn
simp only [Function.onFun, image_add_left, singleton_add, disjoint_left, mem_preimage,
SetLike.mem_coe]
intro y hym hyn
have A : (c ^ n - c ^ m) • x ∈ s := by
convert s.sub_mem hym hyn using 1
simp only [sub_smul, neg_sub_neg, add_sub_add_right_eq_sub]
have H : c ^ n - c ^ m ≠ 0 := by
simpa only [sub_eq_zero, Ne] using (pow_right_strictAnti cpos cone).injective.ne hmn.symm
have : x ∈ s := by
convert s.smul_mem (c ^ n - c ^ m)⁻¹ A
rw [smul_smul, inv_mul_cancel H, one_smul]
exact hx this
#align measure_theory.measure.add_haar_submodule MeasureTheory.Measure.addHaar_submodule
theorem addHaar_affineSubspace {E : Type*} [NormedAddCommGroup E] [NormedSpace ℝ E]
[MeasurableSpace E] [BorelSpace E] [FiniteDimensional ℝ E] (μ : Measure E) [IsAddHaarMeasure μ]
(s : AffineSubspace ℝ E) (hs : s ≠ ⊤) : μ s = 0 := by
rcases s.eq_bot_or_nonempty with (rfl | hne)
· rw [AffineSubspace.bot_coe, measure_empty]
rw [Ne, ← AffineSubspace.direction_eq_top_iff_of_nonempty hne] at hs
rcases hne with ⟨x, hx : x ∈ s⟩
simpa only [AffineSubspace.coe_direction_eq_vsub_set_right hx, vsub_eq_sub, sub_eq_add_neg,
image_add_right, neg_neg, measure_preimage_add_right] using addHaar_submodule μ s.direction hs
#align measure_theory.measure.add_haar_affine_subspace MeasureTheory.Measure.addHaar_affineSubspace
theorem map_linearMap_addHaar_pi_eq_smul_addHaar {ι : Type*} [Finite ι] {f : (ι → ℝ) →ₗ[ℝ] ι → ℝ}
(hf : LinearMap.det f ≠ 0) (μ : Measure (ι → ℝ)) [IsAddHaarMeasure μ] :
Measure.map f μ = ENNReal.ofReal (abs (LinearMap.det f)⁻¹) • μ := by
cases nonempty_fintype ι
have := addHaarMeasure_unique μ (piIcc01 ι)
rw [this, addHaarMeasure_eq_volume_pi, Measure.map_smul,
Real.map_linearMap_volume_pi_eq_smul_volume_pi hf, smul_comm]
#align measure_theory.measure.map_linear_map_add_haar_pi_eq_smul_add_haar MeasureTheory.Measure.map_linearMap_addHaar_pi_eq_smul_addHaar
variable {E : Type*} [NormedAddCommGroup E] [NormedSpace ℝ E] [MeasurableSpace E] [BorelSpace E]
[FiniteDimensional ℝ E] (μ : Measure E) [IsAddHaarMeasure μ] {F : Type*} [NormedAddCommGroup F]
[NormedSpace ℝ F] [CompleteSpace F]
theorem map_linearMap_addHaar_eq_smul_addHaar {f : E →ₗ[ℝ] E} (hf : LinearMap.det f ≠ 0) :
Measure.map f μ = ENNReal.ofReal |(LinearMap.det f)⁻¹| • μ := by
-- we reduce to the case of `E = ι → ℝ`, for which we have already proved the result using
-- matrices in `map_linearMap_addHaar_pi_eq_smul_addHaar`.
let ι := Fin (finrank ℝ E)
haveI : FiniteDimensional ℝ (ι → ℝ) := by infer_instance
have : finrank ℝ E = finrank ℝ (ι → ℝ) := by simp [ι]
have e : E ≃ₗ[ℝ] ι → ℝ := LinearEquiv.ofFinrankEq E (ι → ℝ) this
-- next line is to avoid `g` getting reduced by `simp`.
obtain ⟨g, hg⟩ : ∃ g, g = (e : E →ₗ[ℝ] ι → ℝ).comp (f.comp (e.symm : (ι → ℝ) →ₗ[ℝ] E)) := ⟨_, rfl⟩
have gdet : LinearMap.det g = LinearMap.det f := by rw [hg]; exact LinearMap.det_conj f e
rw [← gdet] at hf ⊢
have fg : f = (e.symm : (ι → ℝ) →ₗ[ℝ] E).comp (g.comp (e : E →ₗ[ℝ] ι → ℝ)) := by
ext x
simp only [LinearEquiv.coe_coe, Function.comp_apply, LinearMap.coe_comp,
LinearEquiv.symm_apply_apply, hg]
simp only [fg, LinearEquiv.coe_coe, LinearMap.coe_comp]
have Ce : Continuous e := (e : E →ₗ[ℝ] ι → ℝ).continuous_of_finiteDimensional
have Cg : Continuous g := LinearMap.continuous_of_finiteDimensional g
have Cesymm : Continuous e.symm := (e.symm : (ι → ℝ) →ₗ[ℝ] E).continuous_of_finiteDimensional
rw [← map_map Cesymm.measurable (Cg.comp Ce).measurable, ← map_map Cg.measurable Ce.measurable]
haveI : IsAddHaarMeasure (map e μ) := (e : E ≃+ (ι → ℝ)).isAddHaarMeasure_map μ Ce Cesymm
have ecomp : e.symm ∘ e = id := by
ext x; simp only [id, Function.comp_apply, LinearEquiv.symm_apply_apply]
rw [map_linearMap_addHaar_pi_eq_smul_addHaar hf (map e μ), Measure.map_smul,
map_map Cesymm.measurable Ce.measurable, ecomp, Measure.map_id]
#align measure_theory.measure.map_linear_map_add_haar_eq_smul_add_haar MeasureTheory.Measure.map_linearMap_addHaar_eq_smul_addHaar
@[simp]
theorem addHaar_preimage_linearMap {f : E →ₗ[ℝ] E} (hf : LinearMap.det f ≠ 0) (s : Set E) :
μ (f ⁻¹' s) = ENNReal.ofReal |(LinearMap.det f)⁻¹| * μ s :=
calc
μ (f ⁻¹' s) = Measure.map f μ s :=
((f.equivOfDetNeZero hf).toContinuousLinearEquiv.toHomeomorph.toMeasurableEquiv.map_apply
s).symm
_ = ENNReal.ofReal |(LinearMap.det f)⁻¹| * μ s := by
rw [map_linearMap_addHaar_eq_smul_addHaar μ hf]; rfl
#align measure_theory.measure.add_haar_preimage_linear_map MeasureTheory.Measure.addHaar_preimage_linearMap
@[simp]
theorem addHaar_preimage_continuousLinearMap {f : E →L[ℝ] E}
(hf : LinearMap.det (f : E →ₗ[ℝ] E) ≠ 0) (s : Set E) :
μ (f ⁻¹' s) = ENNReal.ofReal (abs (LinearMap.det (f : E →ₗ[ℝ] E))⁻¹) * μ s :=
addHaar_preimage_linearMap μ hf s
#align measure_theory.measure.add_haar_preimage_continuous_linear_map MeasureTheory.Measure.addHaar_preimage_continuousLinearMap
@[simp]
theorem addHaar_preimage_linearEquiv (f : E ≃ₗ[ℝ] E) (s : Set E) :
μ (f ⁻¹' s) = ENNReal.ofReal |LinearMap.det (f.symm : E →ₗ[ℝ] E)| * μ s := by
have A : LinearMap.det (f : E →ₗ[ℝ] E) ≠ 0 := (LinearEquiv.isUnit_det' f).ne_zero
convert addHaar_preimage_linearMap μ A s
simp only [LinearEquiv.det_coe_symm]
#align measure_theory.measure.add_haar_preimage_linear_equiv MeasureTheory.Measure.addHaar_preimage_linearEquiv
@[simp]
theorem addHaar_preimage_continuousLinearEquiv (f : E ≃L[ℝ] E) (s : Set E) :
μ (f ⁻¹' s) = ENNReal.ofReal |LinearMap.det (f.symm : E →ₗ[ℝ] E)| * μ s :=
addHaar_preimage_linearEquiv μ _ s
#align measure_theory.measure.add_haar_preimage_continuous_linear_equiv MeasureTheory.Measure.addHaar_preimage_continuousLinearEquiv
@[simp]
theorem addHaar_image_linearMap (f : E →ₗ[ℝ] E) (s : Set E) :
μ (f '' s) = ENNReal.ofReal |LinearMap.det f| * μ s := by
rcases ne_or_eq (LinearMap.det f) 0 with (hf | hf)
· let g := (f.equivOfDetNeZero hf).toContinuousLinearEquiv
change μ (g '' s) = _
rw [ContinuousLinearEquiv.image_eq_preimage g s, addHaar_preimage_continuousLinearEquiv]
congr
· simp only [hf, zero_mul, ENNReal.ofReal_zero, abs_zero]
have : μ (LinearMap.range f) = 0 :=
addHaar_submodule μ _ (LinearMap.range_lt_top_of_det_eq_zero hf).ne
exact le_antisymm (le_trans (measure_mono (image_subset_range _ _)) this.le) (zero_le _)
#align measure_theory.measure.add_haar_image_linear_map MeasureTheory.Measure.addHaar_image_linearMap
@[simp]
theorem addHaar_image_continuousLinearMap (f : E →L[ℝ] E) (s : Set E) :
μ (f '' s) = ENNReal.ofReal |LinearMap.det (f : E →ₗ[ℝ] E)| * μ s :=
addHaar_image_linearMap μ _ s
#align measure_theory.measure.add_haar_image_continuous_linear_map MeasureTheory.Measure.addHaar_image_continuousLinearMap
@[simp]
theorem addHaar_image_continuousLinearEquiv (f : E ≃L[ℝ] E) (s : Set E) :
μ (f '' s) = ENNReal.ofReal |LinearMap.det (f : E →ₗ[ℝ] E)| * μ s :=
μ.addHaar_image_linearMap (f : E →ₗ[ℝ] E) s
#align measure_theory.measure.add_haar_image_continuous_linear_equiv MeasureTheory.Measure.addHaar_image_continuousLinearEquiv
| Mathlib/MeasureTheory/Measure/Lebesgue/EqHaar.lean | 342 | 346 | theorem LinearMap.quasiMeasurePreserving (f : E →ₗ[ℝ] E) (hf : LinearMap.det f ≠ 0) :
QuasiMeasurePreserving f μ μ := by |
refine ⟨f.continuous_of_finiteDimensional.measurable, ?_⟩
rw [map_linearMap_addHaar_eq_smul_addHaar μ hf]
exact smul_absolutelyContinuous
|
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
| Mathlib/Analysis/SpecialFunctions/Pow/Continuity.lean | 44 | 50 | 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
|
import Mathlib.Data.Fintype.List
#align_import data.list.cycle from "leanprover-community/mathlib"@"7413128c3bcb3b0818e3e18720abc9ea3100fb49"
assert_not_exists MonoidWithZero
namespace List
variable {α : Type*} [DecidableEq α]
def nextOr : ∀ (_ : List α) (_ _ : α), α
| [], _, default => default
| [_], _, default => default
-- Handles the not-found and the wraparound case
| y :: z :: xs, x, default => if x = y then z else nextOr (z :: xs) x default
#align list.next_or List.nextOr
@[simp]
theorem nextOr_nil (x d : α) : nextOr [] x d = d :=
rfl
#align list.next_or_nil List.nextOr_nil
@[simp]
theorem nextOr_singleton (x y d : α) : nextOr [y] x d = d :=
rfl
#align list.next_or_singleton List.nextOr_singleton
@[simp]
theorem nextOr_self_cons_cons (xs : List α) (x y d : α) : nextOr (x :: y :: xs) x d = y :=
if_pos rfl
#align list.next_or_self_cons_cons List.nextOr_self_cons_cons
theorem nextOr_cons_of_ne (xs : List α) (y x d : α) (h : x ≠ y) :
nextOr (y :: xs) x d = nextOr xs x d := by
cases' xs with z zs
· rfl
· exact if_neg h
#align list.next_or_cons_of_ne List.nextOr_cons_of_ne
theorem nextOr_eq_nextOr_of_mem_of_ne (xs : List α) (x d d' : α) (x_mem : x ∈ xs)
(x_ne : x ≠ xs.getLast (ne_nil_of_mem x_mem)) : nextOr xs x d = nextOr xs x d' := by
induction' xs with y ys IH
· cases x_mem
cases' ys with z zs
· simp at x_mem x_ne
contradiction
by_cases h : x = y
· rw [h, nextOr_self_cons_cons, nextOr_self_cons_cons]
· rw [nextOr, nextOr, IH]
· simpa [h] using x_mem
· simpa using x_ne
#align list.next_or_eq_next_or_of_mem_of_ne List.nextOr_eq_nextOr_of_mem_of_ne
theorem mem_of_nextOr_ne {xs : List α} {x d : α} (h : nextOr xs x d ≠ d) : x ∈ xs := by
induction' xs with y ys IH
· simp at h
cases' ys with z zs
· simp at h
· by_cases hx : x = y
· simp [hx]
· rw [nextOr_cons_of_ne _ _ _ _ hx] at h
simpa [hx] using IH h
#align list.mem_of_next_or_ne List.mem_of_nextOr_ne
theorem nextOr_concat {xs : List α} {x : α} (d : α) (h : x ∉ xs) : nextOr (xs ++ [x]) x d = d := by
induction' xs with z zs IH
· simp
· obtain ⟨hz, hzs⟩ := not_or.mp (mt mem_cons.2 h)
rw [cons_append, nextOr_cons_of_ne _ _ _ _ hz, IH hzs]
#align list.next_or_concat List.nextOr_concat
theorem nextOr_mem {xs : List α} {x d : α} (hd : d ∈ xs) : nextOr xs x d ∈ xs := by
revert hd
suffices ∀ xs' : List α, (∀ x ∈ xs, x ∈ xs') → d ∈ xs' → nextOr xs x d ∈ xs' by
exact this xs fun _ => id
intro xs' hxs' hd
induction' xs with y ys ih
· exact hd
cases' ys with z zs
· exact hd
rw [nextOr]
split_ifs with h
· exact hxs' _ (mem_cons_of_mem _ (mem_cons_self _ _))
· exact ih fun _ h => hxs' _ (mem_cons_of_mem _ h)
#align list.next_or_mem List.nextOr_mem
def next (l : List α) (x : α) (h : x ∈ l) : α :=
nextOr l x (l.get ⟨0, length_pos_of_mem h⟩)
#align list.next List.next
def prev : ∀ l : List α, ∀ x ∈ l, α
| [], _, h => by simp at h
| [y], _, _ => y
| y :: z :: xs, x, h =>
if hx : x = y then getLast (z :: xs) (cons_ne_nil _ _)
else if x = z then y else prev (z :: xs) x (by simpa [hx] using h)
#align list.prev List.prev
variable (l : List α) (x : α)
@[simp]
theorem next_singleton (x y : α) (h : x ∈ [y]) : next [y] x h = y :=
rfl
#align list.next_singleton List.next_singleton
@[simp]
theorem prev_singleton (x y : α) (h : x ∈ [y]) : prev [y] x h = y :=
rfl
#align list.prev_singleton List.prev_singleton
theorem next_cons_cons_eq' (y z : α) (h : x ∈ y :: z :: l) (hx : x = y) :
next (y :: z :: l) x h = z := by rw [next, nextOr, if_pos hx]
#align list.next_cons_cons_eq' List.next_cons_cons_eq'
@[simp]
theorem next_cons_cons_eq (z : α) (h : x ∈ x :: z :: l) : next (x :: z :: l) x h = z :=
next_cons_cons_eq' l x x z h rfl
#align list.next_cons_cons_eq List.next_cons_cons_eq
theorem next_ne_head_ne_getLast (h : x ∈ l) (y : α) (h : x ∈ y :: l) (hy : x ≠ y)
(hx : x ≠ getLast (y :: l) (cons_ne_nil _ _)) :
next (y :: l) x h = next l x (by simpa [hy] using h) := by
rw [next, next, nextOr_cons_of_ne _ _ _ _ hy, nextOr_eq_nextOr_of_mem_of_ne]
· rwa [getLast_cons] at hx
exact ne_nil_of_mem (by assumption)
· rwa [getLast_cons] at hx
#align list.next_ne_head_ne_last List.next_ne_head_ne_getLast
theorem next_cons_concat (y : α) (hy : x ≠ y) (hx : x ∉ l)
(h : x ∈ y :: l ++ [x] := mem_append_right _ (mem_singleton_self x)) :
next (y :: l ++ [x]) x h = y := by
rw [next, nextOr_concat]
· rfl
· simp [hy, hx]
#align list.next_cons_concat List.next_cons_concat
theorem next_getLast_cons (h : x ∈ l) (y : α) (h : x ∈ y :: l) (hy : x ≠ y)
(hx : x = getLast (y :: l) (cons_ne_nil _ _)) (hl : Nodup l) : next (y :: l) x h = y := by
rw [next, get, ← dropLast_append_getLast (cons_ne_nil y l), hx, nextOr_concat]
subst hx
intro H
obtain ⟨⟨_ | k, hk⟩, hk'⟩ := get_of_mem H
· rw [← Option.some_inj] at hk'
rw [← get?_eq_get, dropLast_eq_take, get?_take, get?_zero, head?_cons,
Option.some_inj] at hk'
· exact hy (Eq.symm hk')
rw [length_cons, Nat.pred_succ]
exact length_pos_of_mem (by assumption)
suffices k + 1 = l.length by simp [this] at hk
cases' l with hd tl
· simp at hk
· rw [nodup_iff_injective_get] at hl
rw [length, Nat.succ_inj']
refine Fin.val_eq_of_eq <| @hl ⟨k, Nat.lt_of_succ_lt <| by simpa using hk⟩
⟨tl.length, by simp⟩ ?_
rw [← Option.some_inj] at hk'
rw [← get?_eq_get, dropLast_eq_take, get?_take, get?, get?_eq_get, Option.some_inj] at hk'
· rw [hk']
simp only [getLast_eq_get, length_cons, ge_iff_le, Nat.succ_sub_succ_eq_sub,
nonpos_iff_eq_zero, add_eq_zero_iff, and_false, Nat.sub_zero, get_cons_succ]
simpa using hk
#align list.next_last_cons List.next_getLast_cons
theorem prev_getLast_cons' (y : α) (hxy : x ∈ y :: l) (hx : x = y) :
prev (y :: l) x hxy = getLast (y :: l) (cons_ne_nil _ _) := by cases l <;> simp [prev, hx]
#align list.prev_last_cons' List.prev_getLast_cons'
@[simp]
theorem prev_getLast_cons (h : x ∈ x :: l) :
prev (x :: l) x h = getLast (x :: l) (cons_ne_nil _ _) :=
prev_getLast_cons' l x x h rfl
#align list.prev_last_cons List.prev_getLast_cons
theorem prev_cons_cons_eq' (y z : α) (h : x ∈ y :: z :: l) (hx : x = y) :
prev (y :: z :: l) x h = getLast (z :: l) (cons_ne_nil _ _) := by rw [prev, dif_pos hx]
#align list.prev_cons_cons_eq' List.prev_cons_cons_eq'
--@[simp] Porting note (#10618): `simp` can prove it
theorem prev_cons_cons_eq (z : α) (h : x ∈ x :: z :: l) :
prev (x :: z :: l) x h = getLast (z :: l) (cons_ne_nil _ _) :=
prev_cons_cons_eq' l x x z h rfl
#align list.prev_cons_cons_eq List.prev_cons_cons_eq
theorem prev_cons_cons_of_ne' (y z : α) (h : x ∈ y :: z :: l) (hy : x ≠ y) (hz : x = z) :
prev (y :: z :: l) x h = y := by
cases l
· simp [prev, hy, hz]
· rw [prev, dif_neg hy, if_pos hz]
#align list.prev_cons_cons_of_ne' List.prev_cons_cons_of_ne'
theorem prev_cons_cons_of_ne (y : α) (h : x ∈ y :: x :: l) (hy : x ≠ y) :
prev (y :: x :: l) x h = y :=
prev_cons_cons_of_ne' _ _ _ _ _ hy rfl
#align list.prev_cons_cons_of_ne List.prev_cons_cons_of_ne
theorem prev_ne_cons_cons (y z : α) (h : x ∈ y :: z :: l) (hy : x ≠ y) (hz : x ≠ z) :
prev (y :: z :: l) x h = prev (z :: l) x (by simpa [hy] using h) := by
cases l
· simp [hy, hz] at h
· rw [prev, dif_neg hy, if_neg hz]
#align list.prev_ne_cons_cons List.prev_ne_cons_cons
theorem next_mem (h : x ∈ l) : l.next x h ∈ l :=
nextOr_mem (get_mem _ _ _)
#align list.next_mem List.next_mem
theorem prev_mem (h : x ∈ l) : l.prev x h ∈ l := by
cases' l with hd tl
· simp at h
induction' tl with hd' tl hl generalizing hd
· simp
· by_cases hx : x = hd
· simp only [hx, prev_cons_cons_eq]
exact mem_cons_of_mem _ (getLast_mem _)
· rw [prev, dif_neg hx]
split_ifs with hm
· exact mem_cons_self _ _
· exact mem_cons_of_mem _ (hl _ _)
#align list.prev_mem List.prev_mem
-- Porting note (#10756): new theorem
theorem next_get : ∀ (l : List α) (_h : Nodup l) (i : Fin l.length),
next l (l.get i) (get_mem _ _ _) = l.get ⟨(i + 1) % l.length,
Nat.mod_lt _ (i.1.zero_le.trans_lt i.2)⟩
| [], _, i => by simpa using i.2
| [_], _, _ => by simp
| x::y::l, _h, ⟨0, h0⟩ => by
have h₁ : get (x :: y :: l) { val := 0, isLt := h0 } = x := by simp
rw [next_cons_cons_eq' _ _ _ _ _ h₁]
simp
| x::y::l, hn, ⟨i+1, hi⟩ => by
have hx' : (x :: y :: l).get ⟨i+1, hi⟩ ≠ x := by
intro H
suffices (i + 1 : ℕ) = 0 by simpa
rw [nodup_iff_injective_get] at hn
refine Fin.val_eq_of_eq (@hn ⟨i + 1, hi⟩ ⟨0, by simp⟩ ?_)
simpa using H
have hi' : i ≤ l.length := Nat.le_of_lt_succ (Nat.succ_lt_succ_iff.1 hi)
rcases hi'.eq_or_lt with (hi' | hi')
· subst hi'
rw [next_getLast_cons]
· simp [hi', get]
· rw [get_cons_succ]; exact get_mem _ _ _
· exact hx'
· simp [getLast_eq_get]
· exact hn.of_cons
· rw [next_ne_head_ne_getLast _ _ _ _ _ hx']
· simp only [get_cons_succ]
rw [next_get (y::l), ← get_cons_succ (a := x)]
· congr
dsimp
rw [Nat.mod_eq_of_lt (Nat.succ_lt_succ_iff.2 hi'),
Nat.mod_eq_of_lt (Nat.succ_lt_succ_iff.2 (Nat.succ_lt_succ_iff.2 hi'))]
· simp [Nat.mod_eq_of_lt (Nat.succ_lt_succ_iff.2 hi'), Nat.succ_eq_add_one, hi']
· exact hn.of_cons
· rw [getLast_eq_get]
intro h
have := nodup_iff_injective_get.1 hn h
simp at this; simp [this] at hi'
· rw [get_cons_succ]; exact get_mem _ _ _
set_option linter.deprecated false in
@[deprecated next_get (since := "2023-01-27")]
theorem next_nthLe (l : List α) (h : Nodup l) (n : ℕ) (hn : n < l.length) :
next l (l.nthLe n hn) (nthLe_mem _ _ _) =
l.nthLe ((n + 1) % l.length) (Nat.mod_lt _ (n.zero_le.trans_lt hn)) :=
next_get l h ⟨n, hn⟩
#align list.next_nth_le List.next_nthLe
set_option linter.deprecated false in
theorem prev_nthLe (l : List α) (h : Nodup l) (n : ℕ) (hn : n < l.length) :
prev l (l.nthLe n hn) (nthLe_mem _ _ _) =
l.nthLe ((n + (l.length - 1)) % l.length) (Nat.mod_lt _ (n.zero_le.trans_lt hn)) := by
cases' l with x l
· simp at hn
induction' l with y l hl generalizing n x
· simp
· rcases n with (_ | _ | n)
· simp [Nat.add_succ_sub_one, add_zero, List.prev_cons_cons_eq, Nat.zero_eq, List.length,
List.nthLe, Nat.succ_add_sub_one, zero_add, getLast_eq_get,
Nat.mod_eq_of_lt (Nat.succ_lt_succ l.length.lt_succ_self)]
· simp only [mem_cons, nodup_cons] at h
push_neg at h
simp only [List.prev_cons_cons_of_ne _ _ _ _ h.left.left.symm, Nat.zero_eq, List.length,
List.nthLe, add_comm, eq_self_iff_true, Nat.succ_add_sub_one, Nat.mod_self, zero_add,
List.get]
· rw [prev_ne_cons_cons]
· convert hl n.succ y h.of_cons (Nat.le_of_succ_le_succ hn) using 1
have : ∀ k hk, (y :: l).nthLe k hk = (x :: y :: l).nthLe (k + 1) (Nat.succ_lt_succ hk) := by
intros
simp [List.nthLe]
rw [this]
congr
simp only [Nat.add_succ_sub_one, add_zero, length]
simp only [length, Nat.succ_lt_succ_iff] at hn
set k := l.length
rw [Nat.succ_add, ← Nat.add_succ, Nat.add_mod_right, Nat.succ_add, ← Nat.add_succ _ k,
Nat.add_mod_right, Nat.mod_eq_of_lt, Nat.mod_eq_of_lt]
· exact Nat.lt_succ_of_lt hn
· exact Nat.succ_lt_succ (Nat.lt_succ_of_lt hn)
· intro H
suffices n.succ.succ = 0 by simpa
rw [nodup_iff_nthLe_inj] at h
refine h _ _ hn Nat.succ_pos' ?_
simpa using H
· intro H
suffices n.succ.succ = 1 by simpa
rw [nodup_iff_nthLe_inj] at h
refine h _ _ hn (Nat.succ_lt_succ Nat.succ_pos') ?_
simpa using H
#align list.prev_nth_le List.prev_nthLe
set_option linter.deprecated false in
theorem pmap_next_eq_rotate_one (h : Nodup l) : (l.pmap l.next fun _ h => h) = l.rotate 1 := by
apply List.ext_nthLe
· simp
· intros
rw [nthLe_pmap, nthLe_rotate, next_nthLe _ h]
#align list.pmap_next_eq_rotate_one List.pmap_next_eq_rotate_one
set_option linter.deprecated false in
theorem pmap_prev_eq_rotate_length_sub_one (h : Nodup l) :
(l.pmap l.prev fun _ h => h) = l.rotate (l.length - 1) := by
apply List.ext_nthLe
· simp
· intro n hn hn'
rw [nthLe_rotate, nthLe_pmap, prev_nthLe _ h]
#align list.pmap_prev_eq_rotate_length_sub_one List.pmap_prev_eq_rotate_length_sub_one
set_option linter.deprecated false in
| Mathlib/Data/List/Cycle.lean | 374 | 383 | theorem prev_next (l : List α) (h : Nodup l) (x : α) (hx : x ∈ l) :
prev l (next l x hx) (next_mem _ _ _) = x := by |
obtain ⟨n, hn, rfl⟩ := nthLe_of_mem hx
simp only [next_nthLe, prev_nthLe, h, Nat.mod_add_mod]
cases' l with hd tl
· simp at hx
· have : (n + 1 + length tl) % (length tl + 1) = n := by
rw [length_cons, Nat.succ_eq_add_one] at hn
rw [add_assoc, add_comm 1, Nat.add_mod_right, Nat.mod_eq_of_lt hn]
simp only [length_cons, Nat.succ_sub_succ_eq_sub, Nat.sub_zero, Nat.succ_eq_add_one, this]
|
import Mathlib.SetTheory.Ordinal.Arithmetic
#align_import set_theory.ordinal.exponential from "leanprover-community/mathlib"@"b67044ba53af18680e1dd246861d9584e968495d"
noncomputable section
open Function Cardinal Set Equiv Order
open scoped Classical
open Cardinal Ordinal
universe u v w
namespace Ordinal
instance pow : Pow Ordinal Ordinal :=
⟨fun a b => if a = 0 then 1 - b else limitRecOn b 1 (fun _ IH => IH * a) fun b _ => bsup.{u, u} b⟩
-- Porting note: Ambiguous notations.
-- local infixr:0 "^" => @Pow.pow Ordinal Ordinal Ordinal.instPowOrdinalOrdinal
theorem opow_def (a b : Ordinal) :
a ^ b = if a = 0 then 1 - b else limitRecOn b 1 (fun _ IH => IH * a) fun b _ => bsup.{u, u} b :=
rfl
#align ordinal.opow_def Ordinal.opow_def
-- Porting note: `if_pos rfl` → `if_true`
theorem zero_opow' (a : Ordinal) : 0 ^ a = 1 - a := by simp only [opow_def, if_true]
#align ordinal.zero_opow' Ordinal.zero_opow'
@[simp]
theorem zero_opow {a : Ordinal} (a0 : a ≠ 0) : (0 : Ordinal) ^ a = 0 := by
rwa [zero_opow', Ordinal.sub_eq_zero_iff_le, one_le_iff_ne_zero]
#align ordinal.zero_opow Ordinal.zero_opow
@[simp]
theorem opow_zero (a : Ordinal) : a ^ (0 : Ordinal) = 1 := by
by_cases h : a = 0
· simp only [opow_def, if_pos h, sub_zero]
· simp only [opow_def, if_neg h, limitRecOn_zero]
#align ordinal.opow_zero Ordinal.opow_zero
@[simp]
theorem opow_succ (a b : Ordinal) : a ^ succ b = a ^ b * a :=
if h : a = 0 then by subst a; simp only [zero_opow (succ_ne_zero _), mul_zero]
else by simp only [opow_def, limitRecOn_succ, if_neg h]
#align ordinal.opow_succ Ordinal.opow_succ
theorem opow_limit {a b : Ordinal} (a0 : a ≠ 0) (h : IsLimit b) :
a ^ b = bsup.{u, u} b fun c _ => a ^ c := by
simp only [opow_def, if_neg a0]; rw [limitRecOn_limit _ _ _ _ h]
#align ordinal.opow_limit Ordinal.opow_limit
theorem opow_le_of_limit {a b c : Ordinal} (a0 : a ≠ 0) (h : IsLimit b) :
a ^ b ≤ c ↔ ∀ b' < b, a ^ b' ≤ c := by rw [opow_limit a0 h, bsup_le_iff]
#align ordinal.opow_le_of_limit Ordinal.opow_le_of_limit
theorem lt_opow_of_limit {a b c : Ordinal} (b0 : b ≠ 0) (h : IsLimit c) :
a < b ^ c ↔ ∃ c' < c, a < b ^ c' := by
rw [← not_iff_not, not_exists]; simp only [not_lt, opow_le_of_limit b0 h, exists_prop, not_and]
#align ordinal.lt_opow_of_limit Ordinal.lt_opow_of_limit
@[simp]
theorem opow_one (a : Ordinal) : a ^ (1 : Ordinal) = a := by
rw [← succ_zero, opow_succ]; simp only [opow_zero, one_mul]
#align ordinal.opow_one Ordinal.opow_one
@[simp]
theorem one_opow (a : Ordinal) : (1 : Ordinal) ^ a = 1 := by
induction a using limitRecOn with
| H₁ => simp only [opow_zero]
| H₂ _ ih =>
simp only [opow_succ, ih, mul_one]
| H₃ b l IH =>
refine eq_of_forall_ge_iff fun c => ?_
rw [opow_le_of_limit Ordinal.one_ne_zero l]
exact ⟨fun H => by simpa only [opow_zero] using H 0 l.pos, fun H b' h => by rwa [IH _ h]⟩
#align ordinal.one_opow Ordinal.one_opow
theorem opow_pos {a : Ordinal} (b : Ordinal) (a0 : 0 < a) : 0 < a ^ b := by
have h0 : 0 < a ^ (0 : Ordinal) := by simp only [opow_zero, zero_lt_one]
induction b using limitRecOn with
| H₁ => exact h0
| H₂ b IH =>
rw [opow_succ]
exact mul_pos IH a0
| H₃ b l _ =>
exact (lt_opow_of_limit (Ordinal.pos_iff_ne_zero.1 a0) l).2 ⟨0, l.pos, h0⟩
#align ordinal.opow_pos Ordinal.opow_pos
theorem opow_ne_zero {a : Ordinal} (b : Ordinal) (a0 : a ≠ 0) : a ^ b ≠ 0 :=
Ordinal.pos_iff_ne_zero.1 <| opow_pos b <| Ordinal.pos_iff_ne_zero.2 a0
#align ordinal.opow_ne_zero Ordinal.opow_ne_zero
theorem opow_isNormal {a : Ordinal} (h : 1 < a) : IsNormal (a ^ ·) :=
have a0 : 0 < a := zero_lt_one.trans h
⟨fun b => by simpa only [mul_one, opow_succ] using (mul_lt_mul_iff_left (opow_pos b a0)).2 h,
fun b l c => opow_le_of_limit (ne_of_gt a0) l⟩
#align ordinal.opow_is_normal Ordinal.opow_isNormal
theorem opow_lt_opow_iff_right {a b c : Ordinal} (a1 : 1 < a) : a ^ b < a ^ c ↔ b < c :=
(opow_isNormal a1).lt_iff
#align ordinal.opow_lt_opow_iff_right Ordinal.opow_lt_opow_iff_right
theorem opow_le_opow_iff_right {a b c : Ordinal} (a1 : 1 < a) : a ^ b ≤ a ^ c ↔ b ≤ c :=
(opow_isNormal a1).le_iff
#align ordinal.opow_le_opow_iff_right Ordinal.opow_le_opow_iff_right
theorem opow_right_inj {a b c : Ordinal} (a1 : 1 < a) : a ^ b = a ^ c ↔ b = c :=
(opow_isNormal a1).inj
#align ordinal.opow_right_inj Ordinal.opow_right_inj
theorem opow_isLimit {a b : Ordinal} (a1 : 1 < a) : IsLimit b → IsLimit (a ^ b) :=
(opow_isNormal a1).isLimit
#align ordinal.opow_is_limit Ordinal.opow_isLimit
theorem opow_isLimit_left {a b : Ordinal} (l : IsLimit a) (hb : b ≠ 0) : IsLimit (a ^ b) := by
rcases zero_or_succ_or_limit b with (e | ⟨b, rfl⟩ | l')
· exact absurd e hb
· rw [opow_succ]
exact mul_isLimit (opow_pos _ l.pos) l
· exact opow_isLimit l.one_lt l'
#align ordinal.opow_is_limit_left Ordinal.opow_isLimit_left
theorem opow_le_opow_right {a b c : Ordinal} (h₁ : 0 < a) (h₂ : b ≤ c) : a ^ b ≤ a ^ c := by
rcases lt_or_eq_of_le (one_le_iff_pos.2 h₁) with h₁ | h₁
· exact (opow_le_opow_iff_right h₁).2 h₂
· subst a
-- Porting note: `le_refl` is required.
simp only [one_opow, le_refl]
#align ordinal.opow_le_opow_right Ordinal.opow_le_opow_right
theorem opow_le_opow_left {a b : Ordinal} (c : Ordinal) (ab : a ≤ b) : a ^ c ≤ b ^ c := by
by_cases a0 : a = 0
-- Porting note: `le_refl` is required.
· subst a
by_cases c0 : c = 0
· subst c
simp only [opow_zero, le_refl]
· simp only [zero_opow c0, Ordinal.zero_le]
· induction c using limitRecOn with
| H₁ => simp only [opow_zero, le_refl]
| H₂ c IH =>
simpa only [opow_succ] using mul_le_mul' IH ab
| H₃ c l IH =>
exact
(opow_le_of_limit a0 l).2 fun b' h =>
(IH _ h).trans (opow_le_opow_right ((Ordinal.pos_iff_ne_zero.2 a0).trans_le ab) h.le)
#align ordinal.opow_le_opow_left Ordinal.opow_le_opow_left
theorem left_le_opow (a : Ordinal) {b : Ordinal} (b1 : 0 < b) : a ≤ a ^ b := by
nth_rw 1 [← opow_one a]
cases' le_or_gt a 1 with a1 a1
· rcases lt_or_eq_of_le a1 with a0 | a1
· rw [lt_one_iff_zero] at a0
rw [a0, zero_opow Ordinal.one_ne_zero]
exact Ordinal.zero_le _
rw [a1, one_opow, one_opow]
rwa [opow_le_opow_iff_right a1, one_le_iff_pos]
#align ordinal.left_le_opow Ordinal.left_le_opow
theorem right_le_opow {a : Ordinal} (b : Ordinal) (a1 : 1 < a) : b ≤ a ^ b :=
(opow_isNormal a1).self_le _
#align ordinal.right_le_opow Ordinal.right_le_opow
theorem opow_lt_opow_left_of_succ {a b c : Ordinal} (ab : a < b) : a ^ succ c < b ^ succ c := by
rw [opow_succ, opow_succ]
exact
(mul_le_mul_right' (opow_le_opow_left c ab.le) a).trans_lt
(mul_lt_mul_of_pos_left ab (opow_pos c ((Ordinal.zero_le a).trans_lt ab)))
#align ordinal.opow_lt_opow_left_of_succ Ordinal.opow_lt_opow_left_of_succ
theorem opow_add (a b c : Ordinal) : a ^ (b + c) = a ^ b * a ^ c := by
rcases eq_or_ne a 0 with (rfl | a0)
· rcases eq_or_ne c 0 with (rfl | c0)
· simp
have : b + c ≠ 0 := ((Ordinal.pos_iff_ne_zero.2 c0).trans_le (le_add_left _ _)).ne'
simp only [zero_opow c0, zero_opow this, mul_zero]
rcases eq_or_lt_of_le (one_le_iff_ne_zero.2 a0) with (rfl | a1)
· simp only [one_opow, mul_one]
induction c using limitRecOn with
| H₁ => simp
| H₂ c IH =>
rw [add_succ, opow_succ, IH, opow_succ, mul_assoc]
| H₃ c l IH =>
refine
eq_of_forall_ge_iff fun d =>
(((opow_isNormal a1).trans (add_isNormal b)).limit_le l).trans ?_
dsimp only [Function.comp_def]
simp (config := { contextual := true }) only [IH]
exact
(((mul_isNormal <| opow_pos b (Ordinal.pos_iff_ne_zero.2 a0)).trans
(opow_isNormal a1)).limit_le
l).symm
#align ordinal.opow_add Ordinal.opow_add
theorem opow_one_add (a b : Ordinal) : a ^ (1 + b) = a * a ^ b := by rw [opow_add, opow_one]
#align ordinal.opow_one_add Ordinal.opow_one_add
theorem opow_dvd_opow (a : Ordinal) {b c : Ordinal} (h : b ≤ c) : a ^ b ∣ a ^ c :=
⟨a ^ (c - b), by rw [← opow_add, Ordinal.add_sub_cancel_of_le h]⟩
#align ordinal.opow_dvd_opow Ordinal.opow_dvd_opow
theorem opow_dvd_opow_iff {a b c : Ordinal} (a1 : 1 < a) : a ^ b ∣ a ^ c ↔ b ≤ c :=
⟨fun h =>
le_of_not_lt fun hn =>
not_le_of_lt ((opow_lt_opow_iff_right a1).2 hn) <|
le_of_dvd (opow_ne_zero _ <| one_le_iff_ne_zero.1 <| a1.le) h,
opow_dvd_opow _⟩
#align ordinal.opow_dvd_opow_iff Ordinal.opow_dvd_opow_iff
theorem opow_mul (a b c : Ordinal) : a ^ (b * c) = (a ^ b) ^ c := by
by_cases b0 : b = 0; · simp only [b0, zero_mul, opow_zero, one_opow]
by_cases a0 : a = 0
· subst a
by_cases c0 : c = 0
· simp only [c0, mul_zero, opow_zero]
simp only [zero_opow b0, zero_opow c0, zero_opow (mul_ne_zero b0 c0)]
cases' eq_or_lt_of_le (one_le_iff_ne_zero.2 a0) with a1 a1
· subst a1
simp only [one_opow]
induction c using limitRecOn with
| H₁ => simp only [mul_zero, opow_zero]
| H₂ c IH =>
rw [mul_succ, opow_add, IH, opow_succ]
| H₃ c l IH =>
refine
eq_of_forall_ge_iff fun d =>
(((opow_isNormal a1).trans (mul_isNormal (Ordinal.pos_iff_ne_zero.2 b0))).limit_le
l).trans
?_
dsimp only [Function.comp_def]
simp (config := { contextual := true }) only [IH]
exact (opow_le_of_limit (opow_ne_zero _ a0) l).symm
#align ordinal.opow_mul Ordinal.opow_mul
-- @[pp_nodot] -- Porting note: Unknown attribute.
def log (b : Ordinal) (x : Ordinal) : Ordinal :=
if _h : 1 < b then pred (sInf { o | x < b ^ o }) else 0
#align ordinal.log Ordinal.log
theorem log_nonempty {b x : Ordinal} (h : 1 < b) : { o : Ordinal | x < b ^ o }.Nonempty :=
⟨_, succ_le_iff.1 (right_le_opow _ h)⟩
#align ordinal.log_nonempty Ordinal.log_nonempty
theorem log_def {b : Ordinal} (h : 1 < b) (x : Ordinal) :
log b x = pred (sInf { o | x < b ^ o }) := by simp only [log, dif_pos h]
#align ordinal.log_def Ordinal.log_def
theorem log_of_not_one_lt_left {b : Ordinal} (h : ¬1 < b) (x : Ordinal) : log b x = 0 := by
simp only [log, dif_neg h]
#align ordinal.log_of_not_one_lt_left Ordinal.log_of_not_one_lt_left
theorem log_of_left_le_one {b : Ordinal} (h : b ≤ 1) : ∀ x, log b x = 0 :=
log_of_not_one_lt_left h.not_lt
#align ordinal.log_of_left_le_one Ordinal.log_of_left_le_one
@[simp]
theorem log_zero_left : ∀ b, log 0 b = 0 :=
log_of_left_le_one zero_le_one
#align ordinal.log_zero_left Ordinal.log_zero_left
@[simp]
theorem log_zero_right (b : Ordinal) : log b 0 = 0 :=
if b1 : 1 < b then by
rw [log_def b1, ← Ordinal.le_zero, pred_le]
apply csInf_le'
dsimp
rw [succ_zero, opow_one]
exact zero_lt_one.trans b1
else by simp only [log_of_not_one_lt_left b1]
#align ordinal.log_zero_right Ordinal.log_zero_right
@[simp]
theorem log_one_left : ∀ b, log 1 b = 0 :=
log_of_left_le_one le_rfl
#align ordinal.log_one_left Ordinal.log_one_left
theorem succ_log_def {b x : Ordinal} (hb : 1 < b) (hx : x ≠ 0) :
succ (log b x) = sInf { o : Ordinal | x < b ^ o } := by
let t := sInf { o : Ordinal | x < b ^ o }
have : x < (b^t) := csInf_mem (log_nonempty hb)
rcases zero_or_succ_or_limit t with (h | h | h)
· refine ((one_le_iff_ne_zero.2 hx).not_lt ?_).elim
simpa only [h, opow_zero] using this
· rw [show log b x = pred t from log_def hb x, succ_pred_iff_is_succ.2 h]
· rcases (lt_opow_of_limit (zero_lt_one.trans hb).ne' h).1 this with ⟨a, h₁, h₂⟩
exact h₁.not_le.elim ((le_csInf_iff'' (log_nonempty hb)).1 le_rfl a h₂)
#align ordinal.succ_log_def Ordinal.succ_log_def
theorem lt_opow_succ_log_self {b : Ordinal} (hb : 1 < b) (x : Ordinal) :
x < b ^ succ (log b x) := by
rcases eq_or_ne x 0 with (rfl | hx)
· apply opow_pos _ (zero_lt_one.trans hb)
· rw [succ_log_def hb hx]
exact csInf_mem (log_nonempty hb)
#align ordinal.lt_opow_succ_log_self Ordinal.lt_opow_succ_log_self
theorem opow_log_le_self (b : Ordinal) {x : Ordinal} (hx : x ≠ 0) : b ^ log b x ≤ x := by
rcases eq_or_ne b 0 with (rfl | b0)
· rw [zero_opow']
exact (sub_le_self _ _).trans (one_le_iff_ne_zero.2 hx)
rcases lt_or_eq_of_le (one_le_iff_ne_zero.2 b0) with (hb | rfl)
· refine le_of_not_lt fun h => (lt_succ (log b x)).not_le ?_
have := @csInf_le' _ _ { o | x < b ^ o } _ h
rwa [← succ_log_def hb hx] at this
· rwa [one_opow, one_le_iff_ne_zero]
#align ordinal.opow_log_le_self Ordinal.opow_log_le_self
theorem opow_le_iff_le_log {b x c : Ordinal} (hb : 1 < b) (hx : x ≠ 0) : b ^ c ≤ x ↔ c ≤ log b x :=
⟨fun h =>
le_of_not_lt fun hn =>
(lt_opow_succ_log_self hb x).not_le <|
((opow_le_opow_iff_right hb).2 (succ_le_of_lt hn)).trans h,
fun h => ((opow_le_opow_iff_right hb).2 h).trans (opow_log_le_self b hx)⟩
#align ordinal.opow_le_iff_le_log Ordinal.opow_le_iff_le_log
theorem lt_opow_iff_log_lt {b x c : Ordinal} (hb : 1 < b) (hx : x ≠ 0) : x < b ^ c ↔ log b x < c :=
lt_iff_lt_of_le_iff_le (opow_le_iff_le_log hb hx)
#align ordinal.lt_opow_iff_log_lt Ordinal.lt_opow_iff_log_lt
theorem log_pos {b o : Ordinal} (hb : 1 < b) (ho : o ≠ 0) (hbo : b ≤ o) : 0 < log b o := by
rwa [← succ_le_iff, succ_zero, ← opow_le_iff_le_log hb ho, opow_one]
#align ordinal.log_pos Ordinal.log_pos
theorem log_eq_zero {b o : Ordinal} (hbo : o < b) : log b o = 0 := by
rcases eq_or_ne o 0 with (rfl | ho)
· exact log_zero_right b
rcases le_or_lt b 1 with hb | hb
· rcases le_one_iff.1 hb with (rfl | rfl)
· exact log_zero_left o
· exact log_one_left o
· rwa [← Ordinal.le_zero, ← lt_succ_iff, succ_zero, ← lt_opow_iff_log_lt hb ho, opow_one]
#align ordinal.log_eq_zero Ordinal.log_eq_zero
@[mono]
theorem log_mono_right (b : Ordinal) {x y : Ordinal} (xy : x ≤ y) : log b x ≤ log b y :=
if hx : x = 0 then by simp only [hx, log_zero_right, Ordinal.zero_le]
else
if hb : 1 < b then
(opow_le_iff_le_log hb (lt_of_lt_of_le (Ordinal.pos_iff_ne_zero.2 hx) xy).ne').1 <|
(opow_log_le_self _ hx).trans xy
else by simp only [log_of_not_one_lt_left hb, Ordinal.zero_le]
#align ordinal.log_mono_right Ordinal.log_mono_right
theorem log_le_self (b x : Ordinal) : log b x ≤ x :=
if hx : x = 0 then by simp only [hx, log_zero_right, Ordinal.zero_le]
else
if hb : 1 < b then (right_le_opow _ hb).trans (opow_log_le_self b hx)
else by simp only [log_of_not_one_lt_left hb, Ordinal.zero_le]
#align ordinal.log_le_self Ordinal.log_le_self
@[simp]
theorem log_one_right (b : Ordinal) : log b 1 = 0 :=
if hb : 1 < b then log_eq_zero hb else log_of_not_one_lt_left hb 1
#align ordinal.log_one_right Ordinal.log_one_right
theorem mod_opow_log_lt_self (b : Ordinal) {o : Ordinal} (ho : o ≠ 0) : o % (b ^ log b o) < o := by
rcases eq_or_ne b 0 with (rfl | hb)
· simpa using Ordinal.pos_iff_ne_zero.2 ho
· exact (mod_lt _ <| opow_ne_zero _ hb).trans_le (opow_log_le_self _ ho)
#align ordinal.mod_opow_log_lt_self Ordinal.mod_opow_log_lt_self
theorem log_mod_opow_log_lt_log_self {b o : Ordinal} (hb : 1 < b) (ho : o ≠ 0) (hbo : b ≤ o) :
log b (o % (b ^ log b o)) < log b o := by
rcases eq_or_ne (o % (b ^ log b o)) 0 with h | h
· rw [h, log_zero_right]
apply log_pos hb ho hbo
· rw [← succ_le_iff, succ_log_def hb h]
apply csInf_le'
apply mod_lt
rw [← Ordinal.pos_iff_ne_zero]
exact opow_pos _ (zero_lt_one.trans hb)
#align ordinal.log_mod_opow_log_lt_log_self Ordinal.log_mod_opow_log_lt_log_self
theorem opow_mul_add_pos {b v : Ordinal} (hb : b ≠ 0) (u : Ordinal) (hv : v ≠ 0) (w : Ordinal) :
0 < b ^ u * v + w :=
(opow_pos u <| Ordinal.pos_iff_ne_zero.2 hb).trans_le <|
(le_mul_left _ <| Ordinal.pos_iff_ne_zero.2 hv).trans <| le_add_right _ _
#align ordinal.opow_mul_add_pos Ordinal.opow_mul_add_pos
theorem opow_mul_add_lt_opow_mul_succ {b u w : Ordinal} (v : Ordinal) (hw : w < b ^ u) :
b ^ u * v + w < b ^ u * succ v := by rwa [mul_succ, add_lt_add_iff_left]
#align ordinal.opow_mul_add_lt_opow_mul_succ Ordinal.opow_mul_add_lt_opow_mul_succ
theorem opow_mul_add_lt_opow_succ {b u v w : Ordinal} (hvb : v < b) (hw : w < b ^ u) :
b ^ u * v + w < b ^ succ u := by
convert (opow_mul_add_lt_opow_mul_succ v hw).trans_le (mul_le_mul_left' (succ_le_of_lt hvb) _)
using 1
exact opow_succ b u
#align ordinal.opow_mul_add_lt_opow_succ Ordinal.opow_mul_add_lt_opow_succ
theorem log_opow_mul_add {b u v w : Ordinal} (hb : 1 < b) (hv : v ≠ 0) (hvb : v < b)
(hw : w < b ^ u) : log b (b ^ u * v + w) = u := by
have hne' := (opow_mul_add_pos (zero_lt_one.trans hb).ne' u hv w).ne'
by_contra! hne
cases' lt_or_gt_of_ne hne with h h
· rw [← lt_opow_iff_log_lt hb hne'] at h
exact h.not_le ((le_mul_left _ (Ordinal.pos_iff_ne_zero.2 hv)).trans (le_add_right _ _))
· conv at h => change u < log b (b ^ u * v + w)
rw [← succ_le_iff, ← opow_le_iff_le_log hb hne'] at h
exact (not_lt_of_le h) (opow_mul_add_lt_opow_succ hvb hw)
#align ordinal.log_opow_mul_add Ordinal.log_opow_mul_add
theorem log_opow {b : Ordinal} (hb : 1 < b) (x : Ordinal) : log b (b ^ x) = x := by
convert log_opow_mul_add hb zero_ne_one.symm hb (opow_pos x (zero_lt_one.trans hb))
using 1
rw [add_zero, mul_one]
#align ordinal.log_opow Ordinal.log_opow
theorem div_opow_log_pos (b : Ordinal) {o : Ordinal} (ho : o ≠ 0) : 0 < o / (b ^ log b o) := by
rcases eq_zero_or_pos b with (rfl | hb)
· simpa using Ordinal.pos_iff_ne_zero.2 ho
· rw [div_pos (opow_ne_zero _ hb.ne')]
exact opow_log_le_self b ho
#align ordinal.div_opow_log_pos Ordinal.div_opow_log_pos
theorem div_opow_log_lt {b : Ordinal} (o : Ordinal) (hb : 1 < b) : o / (b ^ log b o) < b := by
rw [div_lt (opow_pos _ (zero_lt_one.trans hb)).ne', ← opow_succ]
exact lt_opow_succ_log_self hb o
#align ordinal.div_opow_log_lt Ordinal.div_opow_log_lt
theorem add_log_le_log_mul {x y : Ordinal} (b : Ordinal) (hx : x ≠ 0) (hy : y ≠ 0) :
log b x + log b y ≤ log b (x * y) := by
by_cases hb : 1 < b
· rw [← opow_le_iff_le_log hb (mul_ne_zero hx hy), opow_add]
exact mul_le_mul' (opow_log_le_self b hx) (opow_log_le_self b hy)
-- Porting note: `le_refl` is required.
simp only [log_of_not_one_lt_left hb, zero_add, le_refl]
#align ordinal.add_log_le_log_mul Ordinal.add_log_le_log_mul
@[simp, norm_cast]
theorem natCast_opow (m : ℕ) : ∀ n : ℕ, ↑(m ^ n : ℕ) = (m : Ordinal) ^ (n : Ordinal)
| 0 => by simp
| n + 1 => by
rw [pow_succ, natCast_mul, natCast_opow m n, Nat.cast_succ, add_one_eq_succ, opow_succ]
#align ordinal.nat_cast_opow Ordinal.natCast_opow
@[deprecated (since := "2024-04-17")]
alias nat_cast_opow := natCast_opow
| Mathlib/SetTheory/Ordinal/Exponential.lean | 465 | 471 | theorem sup_opow_nat {o : Ordinal} (ho : 0 < o) : (sup fun n : ℕ => o ^ (n : Ordinal)) = o ^ ω := by |
rcases lt_or_eq_of_le (one_le_iff_pos.2 ho) with (ho₁ | rfl)
· exact (opow_isNormal ho₁).apply_omega
· rw [one_opow]
refine le_antisymm (sup_le fun n => by rw [one_opow]) ?_
convert le_sup (fun n : ℕ => 1 ^ (n : Ordinal)) 0
rw [Nat.cast_zero, opow_zero]
|
import Mathlib.NumberTheory.LegendreSymbol.JacobiSymbol
#align_import number_theory.legendre_symbol.norm_num from "leanprover-community/mathlib"@"e2621d935895abe70071ab828a4ee6e26a52afe4"
section Lemmas
namespace Mathlib.Meta.NormNum
def jacobiSymNat (a b : ℕ) : ℤ :=
jacobiSym a b
#align norm_num.jacobi_sym_nat Mathlib.Meta.NormNum.jacobiSymNat
theorem jacobiSymNat.zero_right (a : ℕ) : jacobiSymNat a 0 = 1 := by
rw [jacobiSymNat, jacobiSym.zero_right]
#align norm_num.jacobi_sym_nat.zero_right Mathlib.Meta.NormNum.jacobiSymNat.zero_right
theorem jacobiSymNat.one_right (a : ℕ) : jacobiSymNat a 1 = 1 := by
rw [jacobiSymNat, jacobiSym.one_right]
#align norm_num.jacobi_sym_nat.one_right Mathlib.Meta.NormNum.jacobiSymNat.one_right
theorem jacobiSymNat.zero_left (b : ℕ) (hb : Nat.beq (b / 2) 0 = false) : jacobiSymNat 0 b = 0 := by
rw [jacobiSymNat, Nat.cast_zero, jacobiSym.zero_left ?_]
calc
1 < 2 * 1 := by decide
_ ≤ 2 * (b / 2) :=
Nat.mul_le_mul_left _ (Nat.succ_le.mpr (Nat.pos_of_ne_zero (Nat.ne_of_beq_eq_false hb)))
_ ≤ b := Nat.mul_div_le b 2
#align norm_num.jacobi_sym_nat.zero_left_even Mathlib.Meta.NormNum.jacobiSymNat.zero_left
#align norm_num.jacobi_sym_nat.zero_left_odd Mathlib.Meta.NormNum.jacobiSymNat.zero_left
theorem jacobiSymNat.one_left (b : ℕ) : jacobiSymNat 1 b = 1 := by
rw [jacobiSymNat, Nat.cast_one, jacobiSym.one_left]
#align norm_num.jacobi_sym_nat.one_left_even Mathlib.Meta.NormNum.jacobiSymNat.one_left
#align norm_num.jacobi_sym_nat.one_left_odd Mathlib.Meta.NormNum.jacobiSymNat.one_left
theorem LegendreSym.to_jacobiSym (p : ℕ) (pp : Fact p.Prime) (a r : ℤ)
(hr : IsInt (jacobiSym a p) r) : IsInt (legendreSym p a) r := by
rwa [@jacobiSym.legendreSym.to_jacobiSym p pp a]
#align norm_num.legendre_sym.to_jacobi_sym Mathlib.Meta.NormNum.LegendreSym.to_jacobiSym
theorem JacobiSym.mod_left (a : ℤ) (b ab' : ℕ) (ab r b' : ℤ) (hb' : (b : ℤ) = b')
(hab : a % b' = ab) (h : (ab' : ℤ) = ab) (hr : jacobiSymNat ab' b = r) : jacobiSym a b = r := by
rw [← hr, jacobiSymNat, jacobiSym.mod_left, hb', hab, ← h]
#align norm_num.jacobi_sym.mod_left Mathlib.Meta.NormNum.JacobiSym.mod_left
theorem jacobiSymNat.mod_left (a b ab : ℕ) (r : ℤ) (hab : a % b = ab) (hr : jacobiSymNat ab b = r) :
jacobiSymNat a b = r := by
rw [← hr, jacobiSymNat, jacobiSymNat, _root_.jacobiSym.mod_left a b, ← hab]; rfl
#align norm_num.jacobi_sym_nat.mod_left Mathlib.Meta.NormNum.jacobiSymNat.mod_left
theorem jacobiSymNat.even_even (a b : ℕ) (hb₀ : Nat.beq (b / 2) 0 = false) (ha : a % 2 = 0)
(hb₁ : b % 2 = 0) : jacobiSymNat a b = 0 := by
refine jacobiSym.eq_zero_iff.mpr
⟨ne_of_gt ((Nat.pos_of_ne_zero (Nat.ne_of_beq_eq_false hb₀)).trans_le (Nat.div_le_self b 2)),
fun hf => ?_⟩
have h : 2 ∣ a.gcd b := Nat.dvd_gcd (Nat.dvd_of_mod_eq_zero ha) (Nat.dvd_of_mod_eq_zero hb₁)
change 2 ∣ (a : ℤ).gcd b at h
rw [hf, ← even_iff_two_dvd] at h
exact Nat.not_even_one h
#align norm_num.jacobi_sym_nat.even_even Mathlib.Meta.NormNum.jacobiSymNat.even_even
theorem jacobiSymNat.odd_even (a b c : ℕ) (r : ℤ) (ha : a % 2 = 1) (hb : b % 2 = 0) (hc : b / 2 = c)
(hr : jacobiSymNat a c = r) : jacobiSymNat a b = r := by
have ha' : legendreSym 2 a = 1 := by
simp only [legendreSym.mod 2 a, Int.ofNat_mod_ofNat, ha]
decide
rcases eq_or_ne c 0 with (rfl | hc')
· rw [← hr, Nat.eq_zero_of_dvd_of_div_eq_zero (Nat.dvd_of_mod_eq_zero hb) hc]
· haveI : NeZero c := ⟨hc'⟩
-- for `jacobiSym.mul_right`
rwa [← Nat.mod_add_div b 2, hb, hc, Nat.zero_add, jacobiSymNat, jacobiSym.mul_right,
← jacobiSym.legendreSym.to_jacobiSym, ha', one_mul]
#align norm_num.jacobi_sym_nat.odd_even Mathlib.Meta.NormNum.jacobiSymNat.odd_even
| Mathlib/Tactic/NormNum/LegendreSymbol.lean | 135 | 138 | theorem jacobiSymNat.double_even (a b c : ℕ) (r : ℤ) (ha : a % 4 = 0) (hb : b % 2 = 1)
(hc : a / 4 = c) (hr : jacobiSymNat c b = r) : jacobiSymNat a b = r := by |
simp only [jacobiSymNat, ← hr, ← hc, Int.ofNat_ediv, Nat.cast_ofNat]
exact (jacobiSym.div_four_left (mod_cast ha) hb).symm
|
import Mathlib.Data.ENNReal.Operations
#align_import data.real.ennreal from "leanprover-community/mathlib"@"c14c8fcde993801fca8946b0d80131a1a81d1520"
open Set NNReal
namespace ENNReal
noncomputable section Inv
variable {a b c d : ℝ≥0∞} {r p q : ℝ≥0}
protected theorem div_eq_inv_mul : a / b = b⁻¹ * a := by rw [div_eq_mul_inv, mul_comm]
#align ennreal.div_eq_inv_mul ENNReal.div_eq_inv_mul
@[simp] theorem inv_zero : (0 : ℝ≥0∞)⁻¹ = ∞ :=
show sInf { b : ℝ≥0∞ | 1 ≤ 0 * b } = ∞ by simp
#align ennreal.inv_zero ENNReal.inv_zero
@[simp] theorem inv_top : ∞⁻¹ = 0 :=
bot_unique <| le_of_forall_le_of_dense fun a (h : 0 < a) => sInf_le <| by simp [*, h.ne', top_mul]
#align ennreal.inv_top ENNReal.inv_top
theorem coe_inv_le : (↑r⁻¹ : ℝ≥0∞) ≤ (↑r)⁻¹ :=
le_sInf fun b (hb : 1 ≤ ↑r * b) =>
coe_le_iff.2 <| by
rintro b rfl
apply NNReal.inv_le_of_le_mul
rwa [← coe_mul, ← coe_one, coe_le_coe] at hb
#align ennreal.coe_inv_le ENNReal.coe_inv_le
@[simp, norm_cast]
theorem coe_inv (hr : r ≠ 0) : (↑r⁻¹ : ℝ≥0∞) = (↑r)⁻¹ :=
coe_inv_le.antisymm <| sInf_le <| mem_setOf.2 <| by rw [← coe_mul, mul_inv_cancel hr, coe_one]
#align ennreal.coe_inv ENNReal.coe_inv
@[norm_cast]
theorem coe_inv_two : ((2⁻¹ : ℝ≥0) : ℝ≥0∞) = 2⁻¹ := by rw [coe_inv _root_.two_ne_zero, coe_two]
#align ennreal.coe_inv_two ENNReal.coe_inv_two
@[simp, norm_cast]
theorem coe_div (hr : r ≠ 0) : (↑(p / r) : ℝ≥0∞) = p / r := by
rw [div_eq_mul_inv, div_eq_mul_inv, coe_mul, coe_inv hr]
#align ennreal.coe_div ENNReal.coe_div
lemma coe_div_le : ↑(p / r) ≤ (p / r : ℝ≥0∞) := by
simpa only [div_eq_mul_inv, coe_mul] using mul_le_mul_left' coe_inv_le _
theorem div_zero (h : a ≠ 0) : a / 0 = ∞ := by simp [div_eq_mul_inv, h]
#align ennreal.div_zero ENNReal.div_zero
instance : DivInvOneMonoid ℝ≥0∞ :=
{ inferInstanceAs (DivInvMonoid ℝ≥0∞) with
inv_one := by simpa only [coe_inv one_ne_zero, coe_one] using coe_inj.2 inv_one }
protected theorem inv_pow : ∀ {a : ℝ≥0∞} {n : ℕ}, (a ^ n)⁻¹ = a⁻¹ ^ n
| _, 0 => by simp only [pow_zero, inv_one]
| ⊤, n + 1 => by simp [top_pow]
| (a : ℝ≥0), n + 1 => by
rcases eq_or_ne a 0 with (rfl | ha)
· simp [top_pow]
· have := pow_ne_zero (n + 1) ha
norm_cast
rw [inv_pow]
#align ennreal.inv_pow ENNReal.inv_pow
protected theorem mul_inv_cancel (h0 : a ≠ 0) (ht : a ≠ ∞) : a * a⁻¹ = 1 := by
lift a to ℝ≥0 using ht
norm_cast at h0; norm_cast
exact mul_inv_cancel h0
#align ennreal.mul_inv_cancel ENNReal.mul_inv_cancel
protected theorem inv_mul_cancel (h0 : a ≠ 0) (ht : a ≠ ∞) : a⁻¹ * a = 1 :=
mul_comm a a⁻¹ ▸ ENNReal.mul_inv_cancel h0 ht
#align ennreal.inv_mul_cancel ENNReal.inv_mul_cancel
protected theorem div_mul_cancel (h0 : a ≠ 0) (hI : a ≠ ∞) : b / a * a = b := by
rw [div_eq_mul_inv, mul_assoc, ENNReal.inv_mul_cancel h0 hI, mul_one]
#align ennreal.div_mul_cancel ENNReal.div_mul_cancel
protected theorem mul_div_cancel' (h0 : a ≠ 0) (hI : a ≠ ∞) : a * (b / a) = b := by
rw [mul_comm, ENNReal.div_mul_cancel h0 hI]
#align ennreal.mul_div_cancel' ENNReal.mul_div_cancel'
-- Porting note: `simp only [div_eq_mul_inv, mul_comm, mul_assoc]` doesn't work in the following two
protected theorem mul_comm_div : a / b * c = a * (c / b) := by
simp only [div_eq_mul_inv, mul_right_comm, ← mul_assoc]
#align ennreal.mul_comm_div ENNReal.mul_comm_div
protected theorem mul_div_right_comm : a * b / c = a / c * b := by
simp only [div_eq_mul_inv, mul_right_comm]
#align ennreal.mul_div_right_comm ENNReal.mul_div_right_comm
instance : InvolutiveInv ℝ≥0∞ where
inv_inv a := by
by_cases a = 0 <;> cases a <;> simp_all [none_eq_top, some_eq_coe, -coe_inv, (coe_inv _).symm]
@[simp] protected lemma inv_eq_one : a⁻¹ = 1 ↔ a = 1 := by rw [← inv_inj, inv_inv, inv_one]
@[simp] theorem inv_eq_top : a⁻¹ = ∞ ↔ a = 0 := inv_zero ▸ inv_inj
#align ennreal.inv_eq_top ENNReal.inv_eq_top
theorem inv_ne_top : a⁻¹ ≠ ∞ ↔ a ≠ 0 := by simp
#align ennreal.inv_ne_top ENNReal.inv_ne_top
@[simp]
theorem inv_lt_top {x : ℝ≥0∞} : x⁻¹ < ∞ ↔ 0 < x := by
simp only [lt_top_iff_ne_top, inv_ne_top, pos_iff_ne_zero]
#align ennreal.inv_lt_top ENNReal.inv_lt_top
theorem div_lt_top {x y : ℝ≥0∞} (h1 : x ≠ ∞) (h2 : y ≠ 0) : x / y < ∞ :=
mul_lt_top h1 (inv_ne_top.mpr h2)
#align ennreal.div_lt_top ENNReal.div_lt_top
@[simp]
protected theorem inv_eq_zero : a⁻¹ = 0 ↔ a = ∞ :=
inv_top ▸ inv_inj
#align ennreal.inv_eq_zero ENNReal.inv_eq_zero
protected theorem inv_ne_zero : a⁻¹ ≠ 0 ↔ a ≠ ∞ := by simp
#align ennreal.inv_ne_zero ENNReal.inv_ne_zero
protected theorem div_pos (ha : a ≠ 0) (hb : b ≠ ∞) : 0 < a / b :=
ENNReal.mul_pos ha <| ENNReal.inv_ne_zero.2 hb
#align ennreal.div_pos ENNReal.div_pos
protected theorem mul_inv {a b : ℝ≥0∞} (ha : a ≠ 0 ∨ b ≠ ∞) (hb : a ≠ ∞ ∨ b ≠ 0) :
(a * b)⁻¹ = a⁻¹ * b⁻¹ := by
induction' b with b
· replace ha : a ≠ 0 := ha.neg_resolve_right rfl
simp [ha]
induction' a with a
· replace hb : b ≠ 0 := coe_ne_zero.1 (hb.neg_resolve_left rfl)
simp [hb]
by_cases h'a : a = 0
· simp only [h'a, top_mul, ENNReal.inv_zero, ENNReal.coe_ne_top, zero_mul, Ne,
not_false_iff, ENNReal.coe_zero, ENNReal.inv_eq_zero]
by_cases h'b : b = 0
· simp only [h'b, ENNReal.inv_zero, ENNReal.coe_ne_top, mul_top, Ne, not_false_iff,
mul_zero, ENNReal.coe_zero, ENNReal.inv_eq_zero]
rw [← ENNReal.coe_mul, ← ENNReal.coe_inv, ← ENNReal.coe_inv h'a, ← ENNReal.coe_inv h'b, ←
ENNReal.coe_mul, mul_inv_rev, mul_comm]
simp [h'a, h'b]
#align ennreal.mul_inv ENNReal.mul_inv
protected theorem mul_div_mul_left (a b : ℝ≥0∞) (hc : c ≠ 0) (hc' : c ≠ ⊤) :
c * a / (c * b) = a / b := by
rw [div_eq_mul_inv, div_eq_mul_inv, ENNReal.mul_inv (Or.inl hc) (Or.inl hc'), mul_mul_mul_comm,
ENNReal.mul_inv_cancel hc hc', one_mul]
#align ennreal.mul_div_mul_left ENNReal.mul_div_mul_left
protected theorem mul_div_mul_right (a b : ℝ≥0∞) (hc : c ≠ 0) (hc' : c ≠ ⊤) :
a * c / (b * c) = a / b := by
rw [div_eq_mul_inv, div_eq_mul_inv, ENNReal.mul_inv (Or.inr hc') (Or.inr hc), mul_mul_mul_comm,
ENNReal.mul_inv_cancel hc hc', mul_one]
#align ennreal.mul_div_mul_right ENNReal.mul_div_mul_right
protected theorem sub_div (h : 0 < b → b < a → c ≠ 0) : (a - b) / c = a / c - b / c := by
simp_rw [div_eq_mul_inv]
exact ENNReal.sub_mul (by simpa using h)
#align ennreal.sub_div ENNReal.sub_div
@[simp]
protected theorem inv_pos : 0 < a⁻¹ ↔ a ≠ ∞ :=
pos_iff_ne_zero.trans ENNReal.inv_ne_zero
#align ennreal.inv_pos ENNReal.inv_pos
theorem inv_strictAnti : StrictAnti (Inv.inv : ℝ≥0∞ → ℝ≥0∞) := by
intro a b h
lift a to ℝ≥0 using h.ne_top
induction b; · simp
rw [coe_lt_coe] at h
rcases eq_or_ne a 0 with (rfl | ha); · simp [h]
rw [← coe_inv h.ne_bot, ← coe_inv ha, coe_lt_coe]
exact NNReal.inv_lt_inv ha h
#align ennreal.inv_strict_anti ENNReal.inv_strictAnti
@[simp]
protected theorem inv_lt_inv : a⁻¹ < b⁻¹ ↔ b < a :=
inv_strictAnti.lt_iff_lt
#align ennreal.inv_lt_inv ENNReal.inv_lt_inv
theorem inv_lt_iff_inv_lt : a⁻¹ < b ↔ b⁻¹ < a := by
simpa only [inv_inv] using @ENNReal.inv_lt_inv a b⁻¹
#align ennreal.inv_lt_iff_inv_lt ENNReal.inv_lt_iff_inv_lt
theorem lt_inv_iff_lt_inv : a < b⁻¹ ↔ b < a⁻¹ := by
simpa only [inv_inv] using @ENNReal.inv_lt_inv a⁻¹ b
#align ennreal.lt_inv_iff_lt_inv ENNReal.lt_inv_iff_lt_inv
@[simp]
protected theorem inv_le_inv : a⁻¹ ≤ b⁻¹ ↔ b ≤ a :=
inv_strictAnti.le_iff_le
#align ennreal.inv_le_inv ENNReal.inv_le_inv
theorem inv_le_iff_inv_le : a⁻¹ ≤ b ↔ b⁻¹ ≤ a := by
simpa only [inv_inv] using @ENNReal.inv_le_inv a b⁻¹
#align ennreal.inv_le_iff_inv_le ENNReal.inv_le_iff_inv_le
theorem le_inv_iff_le_inv : a ≤ b⁻¹ ↔ b ≤ a⁻¹ := by
simpa only [inv_inv] using @ENNReal.inv_le_inv a⁻¹ b
#align ennreal.le_inv_iff_le_inv ENNReal.le_inv_iff_le_inv
@[gcongr] protected theorem inv_le_inv' (h : a ≤ b) : b⁻¹ ≤ a⁻¹ :=
ENNReal.inv_strictAnti.antitone h
@[gcongr] protected theorem inv_lt_inv' (h : a < b) : b⁻¹ < a⁻¹ := ENNReal.inv_strictAnti h
@[simp]
protected theorem inv_le_one : a⁻¹ ≤ 1 ↔ 1 ≤ a := by rw [inv_le_iff_inv_le, inv_one]
#align ennreal.inv_le_one ENNReal.inv_le_one
protected theorem one_le_inv : 1 ≤ a⁻¹ ↔ a ≤ 1 := by rw [le_inv_iff_le_inv, inv_one]
#align ennreal.one_le_inv ENNReal.one_le_inv
@[simp]
protected theorem inv_lt_one : a⁻¹ < 1 ↔ 1 < a := by rw [inv_lt_iff_inv_lt, inv_one]
#align ennreal.inv_lt_one ENNReal.inv_lt_one
@[simp]
protected theorem one_lt_inv : 1 < a⁻¹ ↔ a < 1 := by rw [lt_inv_iff_lt_inv, inv_one]
#align ennreal.one_lt_inv ENNReal.one_lt_inv
@[simps! apply]
def _root_.OrderIso.invENNReal : ℝ≥0∞ ≃o ℝ≥0∞ᵒᵈ where
map_rel_iff' := ENNReal.inv_le_inv
toEquiv := (Equiv.inv ℝ≥0∞).trans OrderDual.toDual
#align order_iso.inv_ennreal OrderIso.invENNReal
#align order_iso.inv_ennreal_apply OrderIso.invENNReal_apply
@[simp]
theorem _root_.OrderIso.invENNReal_symm_apply (a : ℝ≥0∞ᵒᵈ) :
OrderIso.invENNReal.symm a = (OrderDual.ofDual a)⁻¹ :=
rfl
#align order_iso.inv_ennreal_symm_apply OrderIso.invENNReal_symm_apply
@[simp] theorem div_top : a / ∞ = 0 := by rw [div_eq_mul_inv, inv_top, mul_zero]
#align ennreal.div_top ENNReal.div_top
-- Porting note: reordered 4 lemmas
theorem top_div : ∞ / a = if a = ∞ then 0 else ∞ := by simp [div_eq_mul_inv, top_mul']
#align ennreal.top_div ENNReal.top_div
theorem top_div_of_ne_top (h : a ≠ ∞) : ∞ / a = ∞ := by simp [top_div, h]
#align ennreal.top_div_of_ne_top ENNReal.top_div_of_ne_top
@[simp] theorem top_div_coe : ∞ / p = ∞ := top_div_of_ne_top coe_ne_top
#align ennreal.top_div_coe ENNReal.top_div_coe
theorem top_div_of_lt_top (h : a < ∞) : ∞ / a = ∞ := top_div_of_ne_top h.ne
#align ennreal.top_div_of_lt_top ENNReal.top_div_of_lt_top
@[simp] protected theorem zero_div : 0 / a = 0 := zero_mul a⁻¹
#align ennreal.zero_div ENNReal.zero_div
theorem div_eq_top : a / b = ∞ ↔ a ≠ 0 ∧ b = 0 ∨ a = ∞ ∧ b ≠ ∞ := by
simp [div_eq_mul_inv, ENNReal.mul_eq_top]
#align ennreal.div_eq_top ENNReal.div_eq_top
protected theorem le_div_iff_mul_le (h0 : b ≠ 0 ∨ c ≠ 0) (ht : b ≠ ∞ ∨ c ≠ ∞) :
a ≤ c / b ↔ a * b ≤ c := by
induction' b with b
· lift c to ℝ≥0 using ht.neg_resolve_left rfl
rw [div_top, nonpos_iff_eq_zero]
rcases eq_or_ne a 0 with (rfl | ha) <;> simp [*]
rcases eq_or_ne b 0 with (rfl | hb)
· have hc : c ≠ 0 := h0.neg_resolve_left rfl
simp [div_zero hc]
· rw [← coe_ne_zero] at hb
rw [← ENNReal.mul_le_mul_right hb coe_ne_top, ENNReal.div_mul_cancel hb coe_ne_top]
#align ennreal.le_div_iff_mul_le ENNReal.le_div_iff_mul_le
protected theorem div_le_iff_le_mul (hb0 : b ≠ 0 ∨ c ≠ ∞) (hbt : b ≠ ∞ ∨ c ≠ 0) :
a / b ≤ c ↔ a ≤ c * b := by
suffices a * b⁻¹ ≤ c ↔ a ≤ c / b⁻¹ by simpa [div_eq_mul_inv]
refine (ENNReal.le_div_iff_mul_le ?_ ?_).symm <;> simpa
#align ennreal.div_le_iff_le_mul ENNReal.div_le_iff_le_mul
protected theorem lt_div_iff_mul_lt (hb0 : b ≠ 0 ∨ c ≠ ∞) (hbt : b ≠ ∞ ∨ c ≠ 0) :
c < a / b ↔ c * b < a :=
lt_iff_lt_of_le_iff_le (ENNReal.div_le_iff_le_mul hb0 hbt)
#align ennreal.lt_div_iff_mul_lt ENNReal.lt_div_iff_mul_lt
theorem div_le_of_le_mul (h : a ≤ b * c) : a / c ≤ b := by
by_cases h0 : c = 0
· have : a = 0 := by simpa [h0] using h
simp [*]
by_cases hinf : c = ∞; · simp [hinf]
exact (ENNReal.div_le_iff_le_mul (Or.inl h0) (Or.inl hinf)).2 h
#align ennreal.div_le_of_le_mul ENNReal.div_le_of_le_mul
theorem div_le_of_le_mul' (h : a ≤ b * c) : a / b ≤ c :=
div_le_of_le_mul <| mul_comm b c ▸ h
#align ennreal.div_le_of_le_mul' ENNReal.div_le_of_le_mul'
protected theorem div_self_le_one : a / a ≤ 1 := div_le_of_le_mul <| by rw [one_mul]
theorem mul_le_of_le_div (h : a ≤ b / c) : a * c ≤ b := by
rw [← inv_inv c]
exact div_le_of_le_mul h
#align ennreal.mul_le_of_le_div ENNReal.mul_le_of_le_div
theorem mul_le_of_le_div' (h : a ≤ b / c) : c * a ≤ b :=
mul_comm a c ▸ mul_le_of_le_div h
#align ennreal.mul_le_of_le_div' ENNReal.mul_le_of_le_div'
protected theorem div_lt_iff (h0 : b ≠ 0 ∨ c ≠ 0) (ht : b ≠ ∞ ∨ c ≠ ∞) : c / b < a ↔ c < a * b :=
lt_iff_lt_of_le_iff_le <| ENNReal.le_div_iff_mul_le h0 ht
#align ennreal.div_lt_iff ENNReal.div_lt_iff
theorem mul_lt_of_lt_div (h : a < b / c) : a * c < b := by
contrapose! h
exact ENNReal.div_le_of_le_mul h
#align ennreal.mul_lt_of_lt_div ENNReal.mul_lt_of_lt_div
theorem mul_lt_of_lt_div' (h : a < b / c) : c * a < b :=
mul_comm a c ▸ mul_lt_of_lt_div h
#align ennreal.mul_lt_of_lt_div' ENNReal.mul_lt_of_lt_div'
theorem div_lt_of_lt_mul (h : a < b * c) : a / c < b :=
mul_lt_of_lt_div <| by rwa [div_eq_mul_inv, inv_inv]
theorem div_lt_of_lt_mul' (h : a < b * c) : a / b < c :=
div_lt_of_lt_mul <| by rwa [mul_comm]
| Mathlib/Data/ENNReal/Inv.lean | 358 | 360 | theorem inv_le_iff_le_mul (h₁ : b = ∞ → a ≠ 0) (h₂ : a = ∞ → b ≠ 0) : a⁻¹ ≤ b ↔ 1 ≤ a * b := by |
rw [← one_div, ENNReal.div_le_iff_le_mul, mul_comm]
exacts [or_not_of_imp h₁, not_or_of_imp h₂]
|
import Batteries.Classes.Order
@[ext] theorem UInt8.ext : {x y : UInt8} → x.toNat = y.toNat → x = y
| ⟨⟨_,_⟩⟩, ⟨⟨_,_⟩⟩, rfl => rfl
theorem UInt8.ext_iff {x y : UInt8} : x = y ↔ x.toNat = y.toNat := ⟨congrArg _, UInt8.ext⟩
@[simp] theorem UInt8.val_val_eq_toNat (x : UInt8) : x.val.val = x.toNat := rfl
theorem UInt8.toNat_lt (x : UInt8) : x.toNat < 2 ^ 8 := x.val.isLt
@[simp] theorem UInt8.toUInt16_toNat (x : UInt8) : x.toUInt16.toNat = x.toNat := rfl
@[simp] theorem UInt8.toUInt32_toNat (x : UInt8) : x.toUInt32.toNat = x.toNat := rfl
@[simp] theorem UInt8.toUInt64_toNat (x : UInt8) : x.toUInt64.toNat = x.toNat := rfl
theorem UInt8.le_antisymm_iff {x y : UInt8} : x = y ↔ x ≤ y ∧ y ≤ x :=
UInt8.ext_iff.trans Nat.le_antisymm_iff
theorem UInt8.le_antisymm {x y : UInt8} (h1 : x ≤ y) (h2 : y ≤ x) : x = y :=
UInt8.le_antisymm_iff.2 ⟨h1, h2⟩
instance : Batteries.LawfulOrd UInt8 := .compareOfLessAndEq
(fun _ => Nat.lt_irrefl _) Nat.lt_trans Nat.not_lt UInt8.le_antisymm
@[ext] theorem UInt16.ext : {x y : UInt16} → x.toNat = y.toNat → x = y
| ⟨⟨_,_⟩⟩, ⟨⟨_,_⟩⟩, rfl => rfl
theorem UInt16.ext_iff {x y : UInt16} : x = y ↔ x.toNat = y.toNat := ⟨congrArg _, UInt16.ext⟩
theorem UInt16.toNat_lt (x : UInt16) : x.toNat < 2 ^ 16 := x.val.isLt
@[simp] theorem UInt16.val_val_eq_toNat (x : UInt16) : x.val.val = x.toNat := rfl
@[simp] theorem UInt16.toUInt8_toNat (x : UInt16) : x.toUInt8.toNat = x.toNat % 2 ^ 8 := rfl
@[simp] theorem UInt16.toUInt32_toNat (x : UInt16) : x.toUInt32.toNat = x.toNat := rfl
@[simp] theorem UInt16.toUInt64_toNat (x : UInt16) : x.toUInt64.toNat = x.toNat := rfl
theorem UInt16.le_antisymm_iff {x y : UInt16} : x = y ↔ x ≤ y ∧ y ≤ x :=
UInt16.ext_iff.trans Nat.le_antisymm_iff
theorem UInt16.le_antisymm {x y : UInt16} (h1 : x ≤ y) (h2 : y ≤ x) : x = y :=
UInt16.le_antisymm_iff.2 ⟨h1, h2⟩
instance : Batteries.LawfulOrd UInt16 := .compareOfLessAndEq
(fun _ => Nat.lt_irrefl _) Nat.lt_trans Nat.not_lt UInt16.le_antisymm
@[ext] theorem UInt32.ext : {x y : UInt32} → x.toNat = y.toNat → x = y
| ⟨⟨_,_⟩⟩, ⟨⟨_,_⟩⟩, rfl => rfl
theorem UInt32.ext_iff {x y : UInt32} : x = y ↔ x.toNat = y.toNat := ⟨congrArg _, UInt32.ext⟩
@[simp] theorem UInt32.val_val_eq_toNat (x : UInt32) : x.val.val = x.toNat := rfl
theorem UInt32.toNat_lt (x : UInt32) : x.toNat < 2 ^ 32 := x.val.isLt
@[simp] theorem UInt32.toUInt8_toNat (x : UInt32) : x.toUInt8.toNat = x.toNat % 2 ^ 8 := rfl
@[simp] theorem UInt32.toUInt16_toNat (x : UInt32) : x.toUInt16.toNat = x.toNat % 2 ^ 16 := rfl
@[simp] theorem UInt32.toUInt64_toNat (x : UInt32) : x.toUInt64.toNat = x.toNat := rfl
theorem UInt32.le_antisymm_iff {x y : UInt32} : x = y ↔ x ≤ y ∧ y ≤ x :=
UInt32.ext_iff.trans Nat.le_antisymm_iff
theorem UInt32.le_antisymm {x y : UInt32} (h1 : x ≤ y) (h2 : y ≤ x) : x = y :=
UInt32.le_antisymm_iff.2 ⟨h1, h2⟩
instance : Batteries.LawfulOrd UInt32 := .compareOfLessAndEq
(fun _ => Nat.lt_irrefl _) Nat.lt_trans Nat.not_lt UInt32.le_antisymm
@[ext] theorem UInt64.ext : {x y : UInt64} → x.toNat = y.toNat → x = y
| ⟨⟨_,_⟩⟩, ⟨⟨_,_⟩⟩, rfl => rfl
theorem UInt64.ext_iff {x y : UInt64} : x = y ↔ x.toNat = y.toNat := ⟨congrArg _, UInt64.ext⟩
@[simp] theorem UInt64.val_val_eq_toNat (x : UInt64) : x.val.val = x.toNat := rfl
theorem UInt64.toNat_lt (x : UInt64) : x.toNat < 2 ^ 64 := x.val.isLt
@[simp] theorem UInt64.toUInt8_toNat (x : UInt64) : x.toUInt8.toNat = x.toNat % 2 ^ 8 := rfl
@[simp] theorem UInt64.toUInt16_toNat (x : UInt64) : x.toUInt16.toNat = x.toNat % 2 ^ 16 := rfl
@[simp] theorem UInt64.toUInt32_toNat (x : UInt64) : x.toUInt32.toNat = x.toNat % 2 ^ 32 := rfl
theorem UInt64.le_antisymm_iff {x y : UInt64} : x = y ↔ x ≤ y ∧ y ≤ x :=
UInt64.ext_iff.trans Nat.le_antisymm_iff
theorem UInt64.le_antisymm {x y : UInt64} (h1 : x ≤ y) (h2 : y ≤ x) : x = y :=
UInt64.le_antisymm_iff.2 ⟨h1, h2⟩
instance : Batteries.LawfulOrd UInt64 := .compareOfLessAndEq
(fun _ => Nat.lt_irrefl _) Nat.lt_trans Nat.not_lt UInt64.le_antisymm
@[ext] theorem USize.ext : {x y : USize} → x.toNat = y.toNat → x = y
| ⟨⟨_,_⟩⟩, ⟨⟨_,_⟩⟩, rfl => rfl
theorem USize.ext_iff {x y : USize} : x = y ↔ x.toNat = y.toNat := ⟨congrArg _, USize.ext⟩
@[simp] theorem USize.val_val_eq_toNat (x : USize) : x.val.val = x.toNat := rfl
theorem USize.size_eq : USize.size = 2 ^ System.Platform.numBits := by
have : 1 ≤ 2 ^ System.Platform.numBits := Nat.succ_le_of_lt (Nat.two_pow_pos _)
rw [USize.size, Nat.sub_add_cancel this]
| .lake/packages/batteries/Batteries/Data/UInt.lean | 125 | 128 | theorem USize.le_size : 2 ^ 32 ≤ USize.size := by |
rw [size_eq]
apply Nat.pow_le_pow_of_le_right (by decide)
cases System.Platform.numBits_eq <;> simp_arith [*]
|
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
| .lake/packages/batteries/Batteries/Data/List/Lemmas.lean | 91 | 100 | 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
|
import Mathlib.Probability.Kernel.MeasurableIntegral
#align_import probability.kernel.composition from "leanprover-community/mathlib"@"3b92d54a05ee592aa2c6181a4e76b1bb7cc45d0b"
open MeasureTheory
open scoped ENNReal
namespace ProbabilityTheory
namespace kernel
variable {α β ι : Type*} {mα : MeasurableSpace α} {mβ : MeasurableSpace β}
section CompositionProduct
variable {γ : Type*} {mγ : MeasurableSpace γ} {s : Set (β × γ)}
noncomputable def compProdFun (κ : kernel α β) (η : kernel (α × β) γ) (a : α) (s : Set (β × γ)) :
ℝ≥0∞ :=
∫⁻ b, η (a, b) {c | (b, c) ∈ s} ∂κ a
#align probability_theory.kernel.comp_prod_fun ProbabilityTheory.kernel.compProdFun
theorem compProdFun_empty (κ : kernel α β) (η : kernel (α × β) γ) (a : α) :
compProdFun κ η a ∅ = 0 := by
simp only [compProdFun, Set.mem_empty_iff_false, Set.setOf_false, measure_empty,
MeasureTheory.lintegral_const, zero_mul]
#align probability_theory.kernel.comp_prod_fun_empty ProbabilityTheory.kernel.compProdFun_empty
theorem compProdFun_iUnion (κ : kernel α β) (η : kernel (α × β) γ) [IsSFiniteKernel η] (a : α)
(f : ℕ → Set (β × γ)) (hf_meas : ∀ i, MeasurableSet (f i))
(hf_disj : Pairwise (Disjoint on f)) :
compProdFun κ η a (⋃ i, f i) = ∑' i, compProdFun κ η a (f i) := by
have h_Union :
(fun b => η (a, b) {c : γ | (b, c) ∈ ⋃ i, f i}) = fun b =>
η (a, b) (⋃ i, {c : γ | (b, c) ∈ f i}) := by
ext1 b
congr with c
simp only [Set.mem_iUnion, Set.iSup_eq_iUnion, Set.mem_setOf_eq]
rw [compProdFun, h_Union]
have h_tsum :
(fun b => η (a, b) (⋃ i, {c : γ | (b, c) ∈ f i})) = fun b =>
∑' i, η (a, b) {c : γ | (b, c) ∈ f i} := by
ext1 b
rw [measure_iUnion]
· intro i j hij s hsi hsj c hcs
have hbci : {(b, c)} ⊆ f i := by rw [Set.singleton_subset_iff]; exact hsi hcs
have hbcj : {(b, c)} ⊆ f j := by rw [Set.singleton_subset_iff]; exact hsj hcs
simpa only [Set.bot_eq_empty, Set.le_eq_subset, Set.singleton_subset_iff,
Set.mem_empty_iff_false] using hf_disj hij hbci hbcj
· -- Porting note: behavior of `@` changed relative to lean 3, was
-- exact fun i => (@measurable_prod_mk_left β γ _ _ b) _ (hf_meas i)
exact fun i => (@measurable_prod_mk_left β γ _ _ b) (hf_meas i)
rw [h_tsum, lintegral_tsum]
· rfl
· intro i
have hm : MeasurableSet {p : (α × β) × γ | (p.1.2, p.2) ∈ f i} :=
measurable_fst.snd.prod_mk measurable_snd (hf_meas i)
exact ((measurable_kernel_prod_mk_left hm).comp measurable_prod_mk_left).aemeasurable
#align probability_theory.kernel.comp_prod_fun_Union ProbabilityTheory.kernel.compProdFun_iUnion
theorem compProdFun_tsum_right (κ : kernel α β) (η : kernel (α × β) γ) [IsSFiniteKernel η] (a : α)
(hs : MeasurableSet s) : compProdFun κ η a s = ∑' n, compProdFun κ (seq η n) a s := by
simp_rw [compProdFun, (measure_sum_seq η _).symm]
have :
∫⁻ b, Measure.sum (fun n => seq η n (a, b)) {c : γ | (b, c) ∈ s} ∂κ a =
∫⁻ b, ∑' n, seq η n (a, b) {c : γ | (b, c) ∈ s} ∂κ a := by
congr
ext1 b
rw [Measure.sum_apply]
exact measurable_prod_mk_left hs
rw [this, lintegral_tsum]
exact fun n => ((measurable_kernel_prod_mk_left (κ := (seq η n))
((measurable_fst.snd.prod_mk measurable_snd) hs)).comp measurable_prod_mk_left).aemeasurable
#align probability_theory.kernel.comp_prod_fun_tsum_right ProbabilityTheory.kernel.compProdFun_tsum_right
theorem compProdFun_tsum_left (κ : kernel α β) (η : kernel (α × β) γ) [IsSFiniteKernel κ] (a : α)
(s : Set (β × γ)) : compProdFun κ η a s = ∑' n, compProdFun (seq κ n) η a s := by
simp_rw [compProdFun, (measure_sum_seq κ _).symm, lintegral_sum_measure]
#align probability_theory.kernel.comp_prod_fun_tsum_left ProbabilityTheory.kernel.compProdFun_tsum_left
theorem compProdFun_eq_tsum (κ : kernel α β) [IsSFiniteKernel κ] (η : kernel (α × β) γ)
[IsSFiniteKernel η] (a : α) (hs : MeasurableSet s) :
compProdFun κ η a s = ∑' (n) (m), compProdFun (seq κ n) (seq η m) a s := by
simp_rw [compProdFun_tsum_left κ η a s, compProdFun_tsum_right _ η a hs]
#align probability_theory.kernel.comp_prod_fun_eq_tsum ProbabilityTheory.kernel.compProdFun_eq_tsum
theorem measurable_compProdFun_of_finite (κ : kernel α β) [IsFiniteKernel κ] (η : kernel (α × β) γ)
[IsFiniteKernel η] (hs : MeasurableSet s) : Measurable fun a => compProdFun κ η a s := by
simp only [compProdFun]
have h_meas : Measurable (Function.uncurry fun a b => η (a, b) {c : γ | (b, c) ∈ s}) := by
have :
(Function.uncurry fun a b => η (a, b) {c : γ | (b, c) ∈ s}) = fun p =>
η p {c : γ | (p.2, c) ∈ s} := by
ext1 p
rw [Function.uncurry_apply_pair]
rw [this]
exact measurable_kernel_prod_mk_left (measurable_fst.snd.prod_mk measurable_snd hs)
exact h_meas.lintegral_kernel_prod_right
#align probability_theory.kernel.measurable_comp_prod_fun_of_finite ProbabilityTheory.kernel.measurable_compProdFun_of_finite
theorem measurable_compProdFun (κ : kernel α β) [IsSFiniteKernel κ] (η : kernel (α × β) γ)
[IsSFiniteKernel η] (hs : MeasurableSet s) : Measurable fun a => compProdFun κ η a s := by
simp_rw [compProdFun_tsum_right κ η _ hs]
refine Measurable.ennreal_tsum fun n => ?_
simp only [compProdFun]
have h_meas : Measurable (Function.uncurry fun a b => seq η n (a, b) {c : γ | (b, c) ∈ s}) := by
have :
(Function.uncurry fun a b => seq η n (a, b) {c : γ | (b, c) ∈ s}) = fun p =>
seq η n p {c : γ | (p.2, c) ∈ s} := by
ext1 p
rw [Function.uncurry_apply_pair]
rw [this]
exact measurable_kernel_prod_mk_left (measurable_fst.snd.prod_mk measurable_snd hs)
exact h_meas.lintegral_kernel_prod_right
#align probability_theory.kernel.measurable_comp_prod_fun ProbabilityTheory.kernel.measurable_compProdFun
open scoped Classical
noncomputable def compProd (κ : kernel α β) (η : kernel (α × β) γ) : kernel α (β × γ) :=
if h : IsSFiniteKernel κ ∧ IsSFiniteKernel η then
{ val := fun a ↦
Measure.ofMeasurable (fun s _ => compProdFun κ η a s) (compProdFun_empty κ η a)
(@compProdFun_iUnion _ _ _ _ _ _ κ η h.2 a)
property := by
have : IsSFiniteKernel κ := h.1
have : IsSFiniteKernel η := h.2
refine Measure.measurable_of_measurable_coe _ fun s hs => ?_
have :
(fun a =>
Measure.ofMeasurable (fun s _ => compProdFun κ η a s) (compProdFun_empty κ η a)
(compProdFun_iUnion κ η a) s) =
fun a => compProdFun κ η a s := by
ext1 a; rwa [Measure.ofMeasurable_apply]
rw [this]
exact measurable_compProdFun κ η hs }
else 0
#align probability_theory.kernel.comp_prod ProbabilityTheory.kernel.compProd
scoped[ProbabilityTheory] infixl:100 " ⊗ₖ " => ProbabilityTheory.kernel.compProd
theorem compProd_apply_eq_compProdFun (κ : kernel α β) [IsSFiniteKernel κ] (η : kernel (α × β) γ)
[IsSFiniteKernel η] (a : α) (hs : MeasurableSet s) :
(κ ⊗ₖ η) a s = compProdFun κ η a s := by
rw [compProd, dif_pos]
swap
· constructor <;> infer_instance
change
Measure.ofMeasurable (fun s _ => compProdFun κ η a s) (compProdFun_empty κ η a)
(compProdFun_iUnion κ η a) s =
∫⁻ b, η (a, b) {c | (b, c) ∈ s} ∂κ a
rw [Measure.ofMeasurable_apply _ hs]
rfl
#align probability_theory.kernel.comp_prod_apply_eq_comp_prod_fun ProbabilityTheory.kernel.compProd_apply_eq_compProdFun
theorem compProd_of_not_isSFiniteKernel_left (κ : kernel α β) (η : kernel (α × β) γ)
(h : ¬ IsSFiniteKernel κ) :
κ ⊗ₖ η = 0 := by
rw [compProd, dif_neg]
simp [h]
theorem compProd_of_not_isSFiniteKernel_right (κ : kernel α β) (η : kernel (α × β) γ)
(h : ¬ IsSFiniteKernel η) :
κ ⊗ₖ η = 0 := by
rw [compProd, dif_neg]
simp [h]
theorem compProd_apply (κ : kernel α β) [IsSFiniteKernel κ] (η : kernel (α × β) γ)
[IsSFiniteKernel η] (a : α) (hs : MeasurableSet s) :
(κ ⊗ₖ η) a s = ∫⁻ b, η (a, b) {c | (b, c) ∈ s} ∂κ a :=
compProd_apply_eq_compProdFun κ η a hs
#align probability_theory.kernel.comp_prod_apply ProbabilityTheory.kernel.compProd_apply
theorem le_compProd_apply (κ : kernel α β) [IsSFiniteKernel κ] (η : kernel (α × β) γ)
[IsSFiniteKernel η] (a : α) (s : Set (β × γ)) :
∫⁻ b, η (a, b) {c | (b, c) ∈ s} ∂κ a ≤ (κ ⊗ₖ η) a s :=
calc
∫⁻ b, η (a, b) {c | (b, c) ∈ s} ∂κ a ≤
∫⁻ b, η (a, b) {c | (b, c) ∈ toMeasurable ((κ ⊗ₖ η) a) s} ∂κ a :=
lintegral_mono fun _ => measure_mono fun _ h_mem => subset_toMeasurable _ _ h_mem
_ = (κ ⊗ₖ η) a (toMeasurable ((κ ⊗ₖ η) a) s) :=
(kernel.compProd_apply_eq_compProdFun κ η a (measurableSet_toMeasurable _ _)).symm
_ = (κ ⊗ₖ η) a s := measure_toMeasurable s
#align probability_theory.kernel.le_comp_prod_apply ProbabilityTheory.kernel.le_compProd_apply
@[simp]
lemma compProd_zero_left (κ : kernel (α × β) γ) :
(0 : kernel α β) ⊗ₖ κ = 0 := by
by_cases h : IsSFiniteKernel κ
· ext a s hs
rw [kernel.compProd_apply _ _ _ hs]
simp
· rw [kernel.compProd_of_not_isSFiniteKernel_right _ _ h]
@[simp]
lemma compProd_zero_right (κ : kernel α β) (γ : Type*) [MeasurableSpace γ] :
κ ⊗ₖ (0 : kernel (α × β) γ) = 0 := by
by_cases h : IsSFiniteKernel κ
· ext a s hs
rw [kernel.compProd_apply _ _ _ hs]
simp
· rw [kernel.compProd_of_not_isSFiniteKernel_left _ _ h]
theorem compProd_eq_tsum_compProd (κ : kernel α β) [IsSFiniteKernel κ] (η : kernel (α × β) γ)
[IsSFiniteKernel η] (a : α) (hs : MeasurableSet s) :
(κ ⊗ₖ η) a s = ∑' (n : ℕ) (m : ℕ), (seq κ n ⊗ₖ seq η m) a s := by
simp_rw [compProd_apply_eq_compProdFun _ _ _ hs]; exact compProdFun_eq_tsum κ η a hs
#align probability_theory.kernel.comp_prod_eq_tsum_comp_prod ProbabilityTheory.kernel.compProd_eq_tsum_compProd
theorem compProd_eq_sum_compProd (κ : kernel α β) [IsSFiniteKernel κ] (η : kernel (α × β) γ)
[IsSFiniteKernel η] : κ ⊗ₖ η = kernel.sum fun n => kernel.sum fun m => seq κ n ⊗ₖ seq η m := by
ext a s hs; simp_rw [kernel.sum_apply' _ a hs]; rw [compProd_eq_tsum_compProd κ η a hs]
#align probability_theory.kernel.comp_prod_eq_sum_comp_prod ProbabilityTheory.kernel.compProd_eq_sum_compProd
theorem compProd_eq_sum_compProd_left (κ : kernel α β) [IsSFiniteKernel κ] (η : kernel (α × β) γ) :
κ ⊗ₖ η = kernel.sum fun n => seq κ n ⊗ₖ η := by
by_cases h : IsSFiniteKernel η
swap
· simp_rw [compProd_of_not_isSFiniteKernel_right _ _ h]
simp
rw [compProd_eq_sum_compProd]
congr with n a s hs
simp_rw [kernel.sum_apply' _ _ hs, compProd_apply_eq_compProdFun _ _ _ hs,
compProdFun_tsum_right _ η a hs]
#align probability_theory.kernel.comp_prod_eq_sum_comp_prod_left ProbabilityTheory.kernel.compProd_eq_sum_compProd_left
theorem compProd_eq_sum_compProd_right (κ : kernel α β) (η : kernel (α × β) γ)
[IsSFiniteKernel η] : κ ⊗ₖ η = kernel.sum fun n => κ ⊗ₖ seq η n := by
by_cases hκ : IsSFiniteKernel κ
swap
· simp_rw [compProd_of_not_isSFiniteKernel_left _ _ hκ]
simp
rw [compProd_eq_sum_compProd]
simp_rw [compProd_eq_sum_compProd_left κ _]
rw [kernel.sum_comm]
#align probability_theory.kernel.comp_prod_eq_sum_comp_prod_right ProbabilityTheory.kernel.compProd_eq_sum_compProd_right
instance IsMarkovKernel.compProd (κ : kernel α β) [IsMarkovKernel κ] (η : kernel (α × β) γ)
[IsMarkovKernel η] : IsMarkovKernel (κ ⊗ₖ η) :=
⟨fun a =>
⟨by
rw [compProd_apply κ η a MeasurableSet.univ]
simp only [Set.mem_univ, Set.setOf_true, measure_univ, lintegral_one]⟩⟩
#align probability_theory.kernel.is_markov_kernel.comp_prod ProbabilityTheory.kernel.IsMarkovKernel.compProd
| Mathlib/Probability/Kernel/Composition.lean | 534 | 547 | theorem compProd_apply_univ_le (κ : kernel α β) (η : kernel (α × β) γ) [IsFiniteKernel η] (a : α) :
(κ ⊗ₖ η) a Set.univ ≤ κ a Set.univ * IsFiniteKernel.bound η := by |
by_cases hκ : IsSFiniteKernel κ
swap
· rw [compProd_of_not_isSFiniteKernel_left _ _ hκ]
simp
rw [compProd_apply κ η a MeasurableSet.univ]
simp only [Set.mem_univ, Set.setOf_true]
let Cη := IsFiniteKernel.bound η
calc
∫⁻ b, η (a, b) Set.univ ∂κ a ≤ ∫⁻ _, Cη ∂κ a :=
lintegral_mono fun b => measure_le_bound η (a, b) Set.univ
_ = Cη * κ a Set.univ := MeasureTheory.lintegral_const Cη
_ = κ a Set.univ * Cη := mul_comm _ _
|
import Mathlib.SetTheory.Ordinal.Basic
import Mathlib.Data.Nat.SuccPred
#align_import set_theory.ordinal.arithmetic from "leanprover-community/mathlib"@"31b269b60935483943542d547a6dd83a66b37dc7"
assert_not_exists Field
assert_not_exists Module
noncomputable section
open Function Cardinal Set Equiv Order
open scoped Classical
open Cardinal Ordinal
universe u v w
namespace Ordinal
variable {α : Type*} {β : Type*} {γ : Type*} {r : α → α → Prop} {s : β → β → Prop}
{t : γ → γ → Prop}
@[simp]
theorem lift_add (a b : Ordinal.{v}) : lift.{u} (a + b) = lift.{u} a + lift.{u} b :=
Quotient.inductionOn₂ a b fun ⟨_α, _r, _⟩ ⟨_β, _s, _⟩ =>
Quotient.sound
⟨(RelIso.preimage Equiv.ulift _).trans
(RelIso.sumLexCongr (RelIso.preimage Equiv.ulift _) (RelIso.preimage Equiv.ulift _)).symm⟩
#align ordinal.lift_add Ordinal.lift_add
@[simp]
theorem lift_succ (a : Ordinal.{v}) : lift.{u} (succ a) = succ (lift.{u} a) := by
rw [← add_one_eq_succ, lift_add, lift_one]
rfl
#align ordinal.lift_succ Ordinal.lift_succ
instance add_contravariantClass_le : ContravariantClass Ordinal.{u} Ordinal.{u} (· + ·) (· ≤ ·) :=
⟨fun a b c =>
inductionOn a fun α r hr =>
inductionOn b fun β₁ s₁ hs₁ =>
inductionOn c fun β₂ s₂ hs₂ ⟨f⟩ =>
⟨have fl : ∀ a, f (Sum.inl a) = Sum.inl a := fun a => by
simpa only [InitialSeg.trans_apply, InitialSeg.leAdd_apply] using
@InitialSeg.eq _ _ _ _ _
((InitialSeg.leAdd r s₁).trans f) (InitialSeg.leAdd r s₂) a
have : ∀ b, { b' // f (Sum.inr b) = Sum.inr b' } := by
intro b; cases e : f (Sum.inr b)
· rw [← fl] at e
have := f.inj' e
contradiction
· exact ⟨_, rfl⟩
let g (b) := (this b).1
have fr : ∀ b, f (Sum.inr b) = Sum.inr (g b) := fun b => (this b).2
⟨⟨⟨g, fun x y h => by
injection f.inj' (by rw [fr, fr, h] : f (Sum.inr x) = f (Sum.inr y))⟩,
@fun a b => by
-- Porting note:
-- `relEmbedding.coe_fn_to_embedding` & `initial_seg.coe_fn_to_rel_embedding`
-- → `InitialSeg.coe_coe_fn`
simpa only [Sum.lex_inr_inr, fr, InitialSeg.coe_coe_fn, Embedding.coeFn_mk] using
@RelEmbedding.map_rel_iff _ _ _ _ f.toRelEmbedding (Sum.inr a) (Sum.inr b)⟩,
fun a b H => by
rcases f.init (by rw [fr] <;> exact Sum.lex_inr_inr.2 H) with ⟨a' | a', h⟩
· rw [fl] at h
cases h
· rw [fr] at h
exact ⟨a', Sum.inr.inj h⟩⟩⟩⟩
#align ordinal.add_contravariant_class_le Ordinal.add_contravariantClass_le
theorem add_left_cancel (a) {b c : Ordinal} : a + b = a + c ↔ b = c := by
simp only [le_antisymm_iff, add_le_add_iff_left]
#align ordinal.add_left_cancel Ordinal.add_left_cancel
private theorem add_lt_add_iff_left' (a) {b c : Ordinal} : a + b < a + c ↔ b < c := by
rw [← not_le, ← not_le, add_le_add_iff_left]
instance add_covariantClass_lt : CovariantClass Ordinal.{u} Ordinal.{u} (· + ·) (· < ·) :=
⟨fun a _b _c => (add_lt_add_iff_left' a).2⟩
#align ordinal.add_covariant_class_lt Ordinal.add_covariantClass_lt
instance add_contravariantClass_lt : ContravariantClass Ordinal.{u} Ordinal.{u} (· + ·) (· < ·) :=
⟨fun a _b _c => (add_lt_add_iff_left' a).1⟩
#align ordinal.add_contravariant_class_lt Ordinal.add_contravariantClass_lt
instance add_swap_contravariantClass_lt :
ContravariantClass Ordinal.{u} Ordinal.{u} (swap (· + ·)) (· < ·) :=
⟨fun _a _b _c => lt_imp_lt_of_le_imp_le fun h => add_le_add_right h _⟩
#align ordinal.add_swap_contravariant_class_lt Ordinal.add_swap_contravariantClass_lt
theorem add_le_add_iff_right {a b : Ordinal} : ∀ n : ℕ, a + n ≤ b + n ↔ a ≤ b
| 0 => by simp
| n + 1 => by
simp only [natCast_succ, add_succ, add_succ, succ_le_succ_iff, add_le_add_iff_right]
#align ordinal.add_le_add_iff_right Ordinal.add_le_add_iff_right
| Mathlib/SetTheory/Ordinal/Arithmetic.lean | 145 | 146 | theorem add_right_cancel {a b : Ordinal} (n : ℕ) : a + n = b + n ↔ a = b := by |
simp only [le_antisymm_iff, add_le_add_iff_right]
|
import Mathlib.Analysis.SpecialFunctions.Trigonometric.Basic
import Mathlib.Topology.Order.ProjIcc
#align_import analysis.special_functions.trigonometric.inverse from "leanprover-community/mathlib"@"f2ce6086713c78a7f880485f7917ea547a215982"
noncomputable section
open scoped Classical
open Topology Filter
open Set Filter
open Real
namespace Real
variable {x y : ℝ}
-- @[pp_nodot] Porting note: not implemented
noncomputable def arcsin : ℝ → ℝ :=
Subtype.val ∘ IccExtend (neg_le_self zero_le_one) sinOrderIso.symm
#align real.arcsin Real.arcsin
theorem arcsin_mem_Icc (x : ℝ) : arcsin x ∈ Icc (-(π / 2)) (π / 2) :=
Subtype.coe_prop _
#align real.arcsin_mem_Icc Real.arcsin_mem_Icc
@[simp]
theorem range_arcsin : range arcsin = Icc (-(π / 2)) (π / 2) := by
rw [arcsin, range_comp Subtype.val]
simp [Icc]
#align real.range_arcsin Real.range_arcsin
theorem arcsin_le_pi_div_two (x : ℝ) : arcsin x ≤ π / 2 :=
(arcsin_mem_Icc x).2
#align real.arcsin_le_pi_div_two Real.arcsin_le_pi_div_two
theorem neg_pi_div_two_le_arcsin (x : ℝ) : -(π / 2) ≤ arcsin x :=
(arcsin_mem_Icc x).1
#align real.neg_pi_div_two_le_arcsin Real.neg_pi_div_two_le_arcsin
theorem arcsin_projIcc (x : ℝ) :
arcsin (projIcc (-1) 1 (neg_le_self zero_le_one) x) = arcsin x := by
rw [arcsin, Function.comp_apply, IccExtend_val, Function.comp_apply, IccExtend,
Function.comp_apply]
#align real.arcsin_proj_Icc Real.arcsin_projIcc
theorem sin_arcsin' {x : ℝ} (hx : x ∈ Icc (-1 : ℝ) 1) : sin (arcsin x) = x := by
simpa [arcsin, IccExtend_of_mem _ _ hx, -OrderIso.apply_symm_apply] using
Subtype.ext_iff.1 (sinOrderIso.apply_symm_apply ⟨x, hx⟩)
#align real.sin_arcsin' Real.sin_arcsin'
theorem sin_arcsin {x : ℝ} (hx₁ : -1 ≤ x) (hx₂ : x ≤ 1) : sin (arcsin x) = x :=
sin_arcsin' ⟨hx₁, hx₂⟩
#align real.sin_arcsin Real.sin_arcsin
theorem arcsin_sin' {x : ℝ} (hx : x ∈ Icc (-(π / 2)) (π / 2)) : arcsin (sin x) = x :=
injOn_sin (arcsin_mem_Icc _) hx <| by rw [sin_arcsin (neg_one_le_sin _) (sin_le_one _)]
#align real.arcsin_sin' Real.arcsin_sin'
theorem arcsin_sin {x : ℝ} (hx₁ : -(π / 2) ≤ x) (hx₂ : x ≤ π / 2) : arcsin (sin x) = x :=
arcsin_sin' ⟨hx₁, hx₂⟩
#align real.arcsin_sin Real.arcsin_sin
theorem strictMonoOn_arcsin : StrictMonoOn arcsin (Icc (-1) 1) :=
(Subtype.strictMono_coe _).comp_strictMonoOn <|
sinOrderIso.symm.strictMono.strictMonoOn_IccExtend _
#align real.strict_mono_on_arcsin Real.strictMonoOn_arcsin
theorem monotone_arcsin : Monotone arcsin :=
(Subtype.mono_coe _).comp <| sinOrderIso.symm.monotone.IccExtend _
#align real.monotone_arcsin Real.monotone_arcsin
theorem injOn_arcsin : InjOn arcsin (Icc (-1) 1) :=
strictMonoOn_arcsin.injOn
#align real.inj_on_arcsin Real.injOn_arcsin
theorem arcsin_inj {x y : ℝ} (hx₁ : -1 ≤ x) (hx₂ : x ≤ 1) (hy₁ : -1 ≤ y) (hy₂ : y ≤ 1) :
arcsin x = arcsin y ↔ x = y :=
injOn_arcsin.eq_iff ⟨hx₁, hx₂⟩ ⟨hy₁, hy₂⟩
#align real.arcsin_inj Real.arcsin_inj
@[continuity]
theorem continuous_arcsin : Continuous arcsin :=
continuous_subtype_val.comp sinOrderIso.symm.continuous.Icc_extend'
#align real.continuous_arcsin Real.continuous_arcsin
theorem continuousAt_arcsin {x : ℝ} : ContinuousAt arcsin x :=
continuous_arcsin.continuousAt
#align real.continuous_at_arcsin Real.continuousAt_arcsin
theorem arcsin_eq_of_sin_eq {x y : ℝ} (h₁ : sin x = y) (h₂ : x ∈ Icc (-(π / 2)) (π / 2)) :
arcsin y = x := by
subst y
exact injOn_sin (arcsin_mem_Icc _) h₂ (sin_arcsin' (sin_mem_Icc x))
#align real.arcsin_eq_of_sin_eq Real.arcsin_eq_of_sin_eq
@[simp]
theorem arcsin_zero : arcsin 0 = 0 :=
arcsin_eq_of_sin_eq sin_zero ⟨neg_nonpos.2 pi_div_two_pos.le, pi_div_two_pos.le⟩
#align real.arcsin_zero Real.arcsin_zero
@[simp]
theorem arcsin_one : arcsin 1 = π / 2 :=
arcsin_eq_of_sin_eq sin_pi_div_two <| right_mem_Icc.2 (neg_le_self pi_div_two_pos.le)
#align real.arcsin_one Real.arcsin_one
theorem arcsin_of_one_le {x : ℝ} (hx : 1 ≤ x) : arcsin x = π / 2 := by
rw [← arcsin_projIcc, projIcc_of_right_le _ hx, Subtype.coe_mk, arcsin_one]
#align real.arcsin_of_one_le Real.arcsin_of_one_le
theorem arcsin_neg_one : arcsin (-1) = -(π / 2) :=
arcsin_eq_of_sin_eq (by rw [sin_neg, sin_pi_div_two]) <|
left_mem_Icc.2 (neg_le_self pi_div_two_pos.le)
#align real.arcsin_neg_one Real.arcsin_neg_one
theorem arcsin_of_le_neg_one {x : ℝ} (hx : x ≤ -1) : arcsin x = -(π / 2) := by
rw [← arcsin_projIcc, projIcc_of_le_left _ hx, Subtype.coe_mk, arcsin_neg_one]
#align real.arcsin_of_le_neg_one Real.arcsin_of_le_neg_one
@[simp]
theorem arcsin_neg (x : ℝ) : arcsin (-x) = -arcsin x := by
rcases le_total x (-1) with hx₁ | hx₁
· rw [arcsin_of_le_neg_one hx₁, neg_neg, arcsin_of_one_le (le_neg.2 hx₁)]
rcases le_total 1 x with hx₂ | hx₂
· rw [arcsin_of_one_le hx₂, arcsin_of_le_neg_one (neg_le_neg hx₂)]
refine arcsin_eq_of_sin_eq ?_ ?_
· rw [sin_neg, sin_arcsin hx₁ hx₂]
· exact ⟨neg_le_neg (arcsin_le_pi_div_two _), neg_le.2 (neg_pi_div_two_le_arcsin _)⟩
#align real.arcsin_neg Real.arcsin_neg
theorem arcsin_le_iff_le_sin {x y : ℝ} (hx : x ∈ Icc (-1 : ℝ) 1) (hy : y ∈ Icc (-(π / 2)) (π / 2)) :
arcsin x ≤ y ↔ x ≤ sin y := by
rw [← arcsin_sin' hy, strictMonoOn_arcsin.le_iff_le hx (sin_mem_Icc _), arcsin_sin' hy]
#align real.arcsin_le_iff_le_sin Real.arcsin_le_iff_le_sin
theorem arcsin_le_iff_le_sin' {x y : ℝ} (hy : y ∈ Ico (-(π / 2)) (π / 2)) :
arcsin x ≤ y ↔ x ≤ sin y := by
rcases le_total x (-1) with hx₁ | hx₁
· simp [arcsin_of_le_neg_one hx₁, hy.1, hx₁.trans (neg_one_le_sin _)]
cases' lt_or_le 1 x with hx₂ hx₂
· simp [arcsin_of_one_le hx₂.le, hy.2.not_le, (sin_le_one y).trans_lt hx₂]
exact arcsin_le_iff_le_sin ⟨hx₁, hx₂⟩ (mem_Icc_of_Ico hy)
#align real.arcsin_le_iff_le_sin' Real.arcsin_le_iff_le_sin'
theorem le_arcsin_iff_sin_le {x y : ℝ} (hx : x ∈ Icc (-(π / 2)) (π / 2)) (hy : y ∈ Icc (-1 : ℝ) 1) :
x ≤ arcsin y ↔ sin x ≤ y := by
rw [← neg_le_neg_iff, ← arcsin_neg,
arcsin_le_iff_le_sin ⟨neg_le_neg hy.2, neg_le.2 hy.1⟩ ⟨neg_le_neg hx.2, neg_le.2 hx.1⟩, sin_neg,
neg_le_neg_iff]
#align real.le_arcsin_iff_sin_le Real.le_arcsin_iff_sin_le
theorem le_arcsin_iff_sin_le' {x y : ℝ} (hx : x ∈ Ioc (-(π / 2)) (π / 2)) :
x ≤ arcsin y ↔ sin x ≤ y := by
rw [← neg_le_neg_iff, ← arcsin_neg, arcsin_le_iff_le_sin' ⟨neg_le_neg hx.2, neg_lt.2 hx.1⟩,
sin_neg, neg_le_neg_iff]
#align real.le_arcsin_iff_sin_le' Real.le_arcsin_iff_sin_le'
theorem arcsin_lt_iff_lt_sin {x y : ℝ} (hx : x ∈ Icc (-1 : ℝ) 1) (hy : y ∈ Icc (-(π / 2)) (π / 2)) :
arcsin x < y ↔ x < sin y :=
not_le.symm.trans <| (not_congr <| le_arcsin_iff_sin_le hy hx).trans not_le
#align real.arcsin_lt_iff_lt_sin Real.arcsin_lt_iff_lt_sin
theorem arcsin_lt_iff_lt_sin' {x y : ℝ} (hy : y ∈ Ioc (-(π / 2)) (π / 2)) :
arcsin x < y ↔ x < sin y :=
not_le.symm.trans <| (not_congr <| le_arcsin_iff_sin_le' hy).trans not_le
#align real.arcsin_lt_iff_lt_sin' Real.arcsin_lt_iff_lt_sin'
theorem lt_arcsin_iff_sin_lt {x y : ℝ} (hx : x ∈ Icc (-(π / 2)) (π / 2)) (hy : y ∈ Icc (-1 : ℝ) 1) :
x < arcsin y ↔ sin x < y :=
not_le.symm.trans <| (not_congr <| arcsin_le_iff_le_sin hy hx).trans not_le
#align real.lt_arcsin_iff_sin_lt Real.lt_arcsin_iff_sin_lt
theorem lt_arcsin_iff_sin_lt' {x y : ℝ} (hx : x ∈ Ico (-(π / 2)) (π / 2)) :
x < arcsin y ↔ sin x < y :=
not_le.symm.trans <| (not_congr <| arcsin_le_iff_le_sin' hx).trans not_le
#align real.lt_arcsin_iff_sin_lt' Real.lt_arcsin_iff_sin_lt'
theorem arcsin_eq_iff_eq_sin {x y : ℝ} (hy : y ∈ Ioo (-(π / 2)) (π / 2)) :
arcsin x = y ↔ x = sin y := by
simp only [le_antisymm_iff, arcsin_le_iff_le_sin' (mem_Ico_of_Ioo hy),
le_arcsin_iff_sin_le' (mem_Ioc_of_Ioo hy)]
#align real.arcsin_eq_iff_eq_sin Real.arcsin_eq_iff_eq_sin
@[simp]
theorem arcsin_nonneg {x : ℝ} : 0 ≤ arcsin x ↔ 0 ≤ x :=
(le_arcsin_iff_sin_le' ⟨neg_lt_zero.2 pi_div_two_pos, pi_div_two_pos.le⟩).trans <| by
rw [sin_zero]
#align real.arcsin_nonneg Real.arcsin_nonneg
@[simp]
theorem arcsin_nonpos {x : ℝ} : arcsin x ≤ 0 ↔ x ≤ 0 :=
neg_nonneg.symm.trans <| arcsin_neg x ▸ arcsin_nonneg.trans neg_nonneg
#align real.arcsin_nonpos Real.arcsin_nonpos
@[simp]
theorem arcsin_eq_zero_iff {x : ℝ} : arcsin x = 0 ↔ x = 0 := by simp [le_antisymm_iff]
#align real.arcsin_eq_zero_iff Real.arcsin_eq_zero_iff
@[simp]
theorem zero_eq_arcsin_iff {x} : 0 = arcsin x ↔ x = 0 :=
eq_comm.trans arcsin_eq_zero_iff
#align real.zero_eq_arcsin_iff Real.zero_eq_arcsin_iff
@[simp]
theorem arcsin_pos {x : ℝ} : 0 < arcsin x ↔ 0 < x :=
lt_iff_lt_of_le_iff_le arcsin_nonpos
#align real.arcsin_pos Real.arcsin_pos
@[simp]
theorem arcsin_lt_zero {x : ℝ} : arcsin x < 0 ↔ x < 0 :=
lt_iff_lt_of_le_iff_le arcsin_nonneg
#align real.arcsin_lt_zero Real.arcsin_lt_zero
@[simp]
theorem arcsin_lt_pi_div_two {x : ℝ} : arcsin x < π / 2 ↔ x < 1 :=
(arcsin_lt_iff_lt_sin' (right_mem_Ioc.2 <| neg_lt_self pi_div_two_pos)).trans <| by
rw [sin_pi_div_two]
#align real.arcsin_lt_pi_div_two Real.arcsin_lt_pi_div_two
@[simp]
theorem neg_pi_div_two_lt_arcsin {x : ℝ} : -(π / 2) < arcsin x ↔ -1 < x :=
(lt_arcsin_iff_sin_lt' <| left_mem_Ico.2 <| neg_lt_self pi_div_two_pos).trans <| by
rw [sin_neg, sin_pi_div_two]
#align real.neg_pi_div_two_lt_arcsin Real.neg_pi_div_two_lt_arcsin
@[simp]
theorem arcsin_eq_pi_div_two {x : ℝ} : arcsin x = π / 2 ↔ 1 ≤ x :=
⟨fun h => not_lt.1 fun h' => (arcsin_lt_pi_div_two.2 h').ne h, arcsin_of_one_le⟩
#align real.arcsin_eq_pi_div_two Real.arcsin_eq_pi_div_two
@[simp]
theorem pi_div_two_eq_arcsin {x} : π / 2 = arcsin x ↔ 1 ≤ x :=
eq_comm.trans arcsin_eq_pi_div_two
#align real.pi_div_two_eq_arcsin Real.pi_div_two_eq_arcsin
@[simp]
theorem pi_div_two_le_arcsin {x} : π / 2 ≤ arcsin x ↔ 1 ≤ x :=
(arcsin_le_pi_div_two x).le_iff_eq.trans pi_div_two_eq_arcsin
#align real.pi_div_two_le_arcsin Real.pi_div_two_le_arcsin
@[simp]
theorem arcsin_eq_neg_pi_div_two {x : ℝ} : arcsin x = -(π / 2) ↔ x ≤ -1 :=
⟨fun h => not_lt.1 fun h' => (neg_pi_div_two_lt_arcsin.2 h').ne' h, arcsin_of_le_neg_one⟩
#align real.arcsin_eq_neg_pi_div_two Real.arcsin_eq_neg_pi_div_two
@[simp]
theorem neg_pi_div_two_eq_arcsin {x} : -(π / 2) = arcsin x ↔ x ≤ -1 :=
eq_comm.trans arcsin_eq_neg_pi_div_two
#align real.neg_pi_div_two_eq_arcsin Real.neg_pi_div_two_eq_arcsin
@[simp]
theorem arcsin_le_neg_pi_div_two {x} : arcsin x ≤ -(π / 2) ↔ x ≤ -1 :=
(neg_pi_div_two_le_arcsin x).le_iff_eq.trans arcsin_eq_neg_pi_div_two
#align real.arcsin_le_neg_pi_div_two Real.arcsin_le_neg_pi_div_two
@[simp]
theorem pi_div_four_le_arcsin {x} : π / 4 ≤ arcsin x ↔ √2 / 2 ≤ x := by
rw [← sin_pi_div_four, le_arcsin_iff_sin_le']
have := pi_pos
constructor <;> linarith
#align real.pi_div_four_le_arcsin Real.pi_div_four_le_arcsin
theorem mapsTo_sin_Ioo : MapsTo sin (Ioo (-(π / 2)) (π / 2)) (Ioo (-1) 1) := fun x h => by
rwa [mem_Ioo, ← arcsin_lt_pi_div_two, ← neg_pi_div_two_lt_arcsin, arcsin_sin h.1.le h.2.le]
#align real.maps_to_sin_Ioo Real.mapsTo_sin_Ioo
@[simp]
def sinPartialHomeomorph : PartialHomeomorph ℝ ℝ where
toFun := sin
invFun := arcsin
source := Ioo (-(π / 2)) (π / 2)
target := Ioo (-1) 1
map_source' := mapsTo_sin_Ioo
map_target' _ hy := ⟨neg_pi_div_two_lt_arcsin.2 hy.1, arcsin_lt_pi_div_two.2 hy.2⟩
left_inv' _ hx := arcsin_sin hx.1.le hx.2.le
right_inv' _ hy := sin_arcsin hy.1.le hy.2.le
open_source := isOpen_Ioo
open_target := isOpen_Ioo
continuousOn_toFun := continuous_sin.continuousOn
continuousOn_invFun := continuous_arcsin.continuousOn
#align real.sin_local_homeomorph Real.sinPartialHomeomorph
theorem cos_arcsin_nonneg (x : ℝ) : 0 ≤ cos (arcsin x) :=
cos_nonneg_of_mem_Icc ⟨neg_pi_div_two_le_arcsin _, arcsin_le_pi_div_two _⟩
#align real.cos_arcsin_nonneg Real.cos_arcsin_nonneg
-- The junk values for `arcsin` and `sqrt` make this true even outside `[-1, 1]`.
theorem cos_arcsin (x : ℝ) : cos (arcsin x) = √(1 - x ^ 2) := by
by_cases hx₁ : -1 ≤ x; swap
· rw [not_le] at hx₁
rw [arcsin_of_le_neg_one hx₁.le, cos_neg, cos_pi_div_two, sqrt_eq_zero_of_nonpos]
nlinarith
by_cases hx₂ : x ≤ 1; swap
· rw [not_le] at hx₂
rw [arcsin_of_one_le hx₂.le, cos_pi_div_two, sqrt_eq_zero_of_nonpos]
nlinarith
have : sin (arcsin x) ^ 2 + cos (arcsin x) ^ 2 = 1 := sin_sq_add_cos_sq (arcsin x)
rw [← eq_sub_iff_add_eq', ← sqrt_inj (sq_nonneg _) (sub_nonneg.2 (sin_sq_le_one (arcsin x))), sq,
sqrt_mul_self (cos_arcsin_nonneg _)] at this
rw [this, sin_arcsin hx₁ hx₂]
#align real.cos_arcsin Real.cos_arcsin
-- The junk values for `arcsin` and `sqrt` make this true even outside `[-1, 1]`.
theorem tan_arcsin (x : ℝ) : tan (arcsin x) = x / √(1 - x ^ 2) := by
rw [tan_eq_sin_div_cos, cos_arcsin]
by_cases hx₁ : -1 ≤ x; swap
· have h : √(1 - x ^ 2) = 0 := sqrt_eq_zero_of_nonpos (by nlinarith)
rw [h]
simp
by_cases hx₂ : x ≤ 1; swap
· have h : √(1 - x ^ 2) = 0 := sqrt_eq_zero_of_nonpos (by nlinarith)
rw [h]
simp
rw [sin_arcsin hx₁ hx₂]
#align real.tan_arcsin Real.tan_arcsin
-- @[pp_nodot] Porting note: not implemented
noncomputable def arccos (x : ℝ) : ℝ :=
π / 2 - arcsin x
#align real.arccos Real.arccos
theorem arccos_eq_pi_div_two_sub_arcsin (x : ℝ) : arccos x = π / 2 - arcsin x :=
rfl
#align real.arccos_eq_pi_div_two_sub_arcsin Real.arccos_eq_pi_div_two_sub_arcsin
theorem arcsin_eq_pi_div_two_sub_arccos (x : ℝ) : arcsin x = π / 2 - arccos x := by simp [arccos]
#align real.arcsin_eq_pi_div_two_sub_arccos Real.arcsin_eq_pi_div_two_sub_arccos
theorem arccos_le_pi (x : ℝ) : arccos x ≤ π := by
unfold arccos; linarith [neg_pi_div_two_le_arcsin x]
#align real.arccos_le_pi Real.arccos_le_pi
theorem arccos_nonneg (x : ℝ) : 0 ≤ arccos x := by
unfold arccos; linarith [arcsin_le_pi_div_two x]
#align real.arccos_nonneg Real.arccos_nonneg
@[simp]
theorem arccos_pos {x : ℝ} : 0 < arccos x ↔ x < 1 := by simp [arccos]
#align real.arccos_pos Real.arccos_pos
theorem cos_arccos {x : ℝ} (hx₁ : -1 ≤ x) (hx₂ : x ≤ 1) : cos (arccos x) = x := by
rw [arccos, cos_pi_div_two_sub, sin_arcsin hx₁ hx₂]
#align real.cos_arccos Real.cos_arccos
theorem arccos_cos {x : ℝ} (hx₁ : 0 ≤ x) (hx₂ : x ≤ π) : arccos (cos x) = x := by
rw [arccos, ← sin_pi_div_two_sub, arcsin_sin] <;> simp [sub_eq_add_neg] <;> linarith
#align real.arccos_cos Real.arccos_cos
lemma arccos_eq_of_eq_cos (hy₀ : 0 ≤ y) (hy₁ : y ≤ π) (hxy : x = cos y) : arccos x = y := by
rw [hxy, arccos_cos hy₀ hy₁]
theorem strictAntiOn_arccos : StrictAntiOn arccos (Icc (-1) 1) := fun _ hx _ hy h =>
sub_lt_sub_left (strictMonoOn_arcsin hx hy h) _
#align real.strict_anti_on_arccos Real.strictAntiOn_arccos
theorem arccos_injOn : InjOn arccos (Icc (-1) 1) :=
strictAntiOn_arccos.injOn
#align real.arccos_inj_on Real.arccos_injOn
theorem arccos_inj {x y : ℝ} (hx₁ : -1 ≤ x) (hx₂ : x ≤ 1) (hy₁ : -1 ≤ y) (hy₂ : y ≤ 1) :
arccos x = arccos y ↔ x = y :=
arccos_injOn.eq_iff ⟨hx₁, hx₂⟩ ⟨hy₁, hy₂⟩
#align real.arccos_inj Real.arccos_inj
@[simp]
theorem arccos_zero : arccos 0 = π / 2 := by simp [arccos]
#align real.arccos_zero Real.arccos_zero
@[simp]
theorem arccos_one : arccos 1 = 0 := by simp [arccos]
#align real.arccos_one Real.arccos_one
@[simp]
theorem arccos_neg_one : arccos (-1) = π := by simp [arccos, add_halves]
#align real.arccos_neg_one Real.arccos_neg_one
@[simp]
theorem arccos_eq_zero {x} : arccos x = 0 ↔ 1 ≤ x := by simp [arccos, sub_eq_zero]
#align real.arccos_eq_zero Real.arccos_eq_zero
@[simp]
theorem arccos_eq_pi_div_two {x} : arccos x = π / 2 ↔ x = 0 := by simp [arccos]
#align real.arccos_eq_pi_div_two Real.arccos_eq_pi_div_two
@[simp]
theorem arccos_eq_pi {x} : arccos x = π ↔ x ≤ -1 := by
rw [arccos, sub_eq_iff_eq_add, ← sub_eq_iff_eq_add', div_two_sub_self, neg_pi_div_two_eq_arcsin]
#align real.arccos_eq_pi Real.arccos_eq_pi
| Mathlib/Analysis/SpecialFunctions/Trigonometric/Inverse.lean | 410 | 411 | theorem arccos_neg (x : ℝ) : arccos (-x) = π - arccos x := by |
rw [← add_halves π, arccos, arcsin_neg, arccos, add_sub_assoc, sub_sub_self, sub_neg_eq_add]
|
import Mathlib.Data.Nat.Multiplicity
import Mathlib.Data.ZMod.Algebra
import Mathlib.RingTheory.WittVector.Basic
import Mathlib.RingTheory.WittVector.IsPoly
import Mathlib.FieldTheory.Perfect
#align_import ring_theory.witt_vector.frobenius from "leanprover-community/mathlib"@"0723536a0522d24fc2f159a096fb3304bef77472"
namespace WittVector
variable {p : ℕ} {R S : Type*} [hp : Fact p.Prime] [CommRing R] [CommRing S]
local notation "𝕎" => WittVector p -- type as `\bbW`
noncomputable section
open MvPolynomial Finset
variable (p)
def frobeniusPolyRat (n : ℕ) : MvPolynomial ℕ ℚ :=
bind₁ (wittPolynomial p ℚ ∘ fun n => n + 1) (xInTermsOfW p ℚ n)
#align witt_vector.frobenius_poly_rat WittVector.frobeniusPolyRat
theorem bind₁_frobeniusPolyRat_wittPolynomial (n : ℕ) :
bind₁ (frobeniusPolyRat p) (wittPolynomial p ℚ n) = wittPolynomial p ℚ (n + 1) := by
delta frobeniusPolyRat
rw [← bind₁_bind₁, bind₁_xInTermsOfW_wittPolynomial, bind₁_X_right, Function.comp_apply]
#align witt_vector.bind₁_frobenius_poly_rat_witt_polynomial WittVector.bind₁_frobeniusPolyRat_wittPolynomial
private def pnat_multiplicity (n : ℕ+) : ℕ :=
(multiplicity p n).get <| multiplicity.finite_nat_iff.mpr <| ⟨ne_of_gt hp.1.one_lt, n.2⟩
local notation "v" => pnat_multiplicity
noncomputable def frobeniusPolyAux : ℕ → MvPolynomial ℕ ℤ
| n => X (n + 1) - ∑ i : Fin n, have _ := i.is_lt
∑ j ∈ range (p ^ (n - i)),
(((X (i : ℕ) ^ p) ^ (p ^ (n - (i : ℕ)) - (j + 1)) : MvPolynomial ℕ ℤ) *
(frobeniusPolyAux i) ^ (j + 1)) *
C (((p ^ (n - i)).choose (j + 1) / (p ^ (n - i - v p ⟨j + 1, Nat.succ_pos j⟩))
* ↑p ^ (j - v p ⟨j + 1, Nat.succ_pos j⟩) : ℕ) : ℤ)
#align witt_vector.frobenius_poly_aux WittVector.frobeniusPolyAux
theorem frobeniusPolyAux_eq (n : ℕ) :
frobeniusPolyAux p n =
X (n + 1) - ∑ i ∈ range n,
∑ j ∈ range (p ^ (n - i)),
(X i ^ p) ^ (p ^ (n - i) - (j + 1)) * frobeniusPolyAux p i ^ (j + 1) *
C ↑((p ^ (n - i)).choose (j + 1) / p ^ (n - i - v p ⟨j + 1, Nat.succ_pos j⟩) *
↑p ^ (j - v p ⟨j + 1, Nat.succ_pos j⟩) : ℕ) := by
rw [frobeniusPolyAux, ← Fin.sum_univ_eq_sum_range]
#align witt_vector.frobenius_poly_aux_eq WittVector.frobeniusPolyAux_eq
def frobeniusPoly (n : ℕ) : MvPolynomial ℕ ℤ :=
X n ^ p + C (p : ℤ) * frobeniusPolyAux p n
#align witt_vector.frobenius_poly WittVector.frobeniusPoly
theorem map_frobeniusPoly.key₁ (n j : ℕ) (hj : j < p ^ n) :
p ^ (n - v p ⟨j + 1, j.succ_pos⟩) ∣ (p ^ n).choose (j + 1) := by
apply multiplicity.pow_dvd_of_le_multiplicity
rw [hp.out.multiplicity_choose_prime_pow hj j.succ_ne_zero]
rfl
#align witt_vector.map_frobenius_poly.key₁ WittVector.map_frobeniusPoly.key₁
theorem map_frobeniusPoly.key₂ {n i j : ℕ} (hi : i ≤ n) (hj : j < p ^ (n - i)) :
j - v p ⟨j + 1, j.succ_pos⟩ + n = i + j + (n - i - v p ⟨j + 1, j.succ_pos⟩) := by
generalize h : v p ⟨j + 1, j.succ_pos⟩ = m
rsuffices ⟨h₁, h₂⟩ : m ≤ n - i ∧ m ≤ j
· rw [tsub_add_eq_add_tsub h₂, add_comm i j, add_tsub_assoc_of_le (h₁.trans (Nat.sub_le n i)),
add_assoc, tsub_right_comm, add_comm i,
tsub_add_cancel_of_le (le_tsub_of_add_le_right ((le_tsub_iff_left hi).mp h₁))]
have hle : p ^ m ≤ j + 1 := h ▸ Nat.le_of_dvd j.succ_pos (multiplicity.pow_multiplicity_dvd _)
exact ⟨(pow_le_pow_iff_right hp.1.one_lt).1 (hle.trans hj),
Nat.le_of_lt_succ ((Nat.lt_pow_self hp.1.one_lt m).trans_le hle)⟩
#align witt_vector.map_frobenius_poly.key₂ WittVector.map_frobeniusPoly.key₂
| Mathlib/RingTheory/WittVector/Frobenius.lean | 143 | 193 | theorem map_frobeniusPoly (n : ℕ) :
MvPolynomial.map (Int.castRingHom ℚ) (frobeniusPoly p n) = frobeniusPolyRat p n := by |
rw [frobeniusPoly, RingHom.map_add, RingHom.map_mul, RingHom.map_pow, map_C, map_X, eq_intCast,
Int.cast_natCast, frobeniusPolyRat]
refine Nat.strong_induction_on n ?_; clear n
intro n IH
rw [xInTermsOfW_eq]
simp only [AlgHom.map_sum, AlgHom.map_sub, AlgHom.map_mul, AlgHom.map_pow, bind₁_C_right]
have h1 : (p : ℚ) ^ n * ⅟ (p : ℚ) ^ n = 1 := by rw [← mul_pow, mul_invOf_self, one_pow]
rw [bind₁_X_right, Function.comp_apply, wittPolynomial_eq_sum_C_mul_X_pow, sum_range_succ,
sum_range_succ, tsub_self, add_tsub_cancel_left, pow_zero, pow_one, pow_one, sub_mul, add_mul,
add_mul, mul_right_comm, mul_right_comm (C ((p : ℚ) ^ (n + 1))), ← C_mul, ← C_mul, pow_succ',
mul_assoc (p : ℚ) ((p : ℚ) ^ n), h1, mul_one, C_1, one_mul, add_comm _ (X n ^ p), add_assoc,
← add_sub, add_right_inj, frobeniusPolyAux_eq, RingHom.map_sub, map_X, mul_sub, sub_eq_add_neg,
add_comm _ (C (p : ℚ) * X (n + 1)), ← add_sub,
add_right_inj, neg_eq_iff_eq_neg, neg_sub, eq_comm]
simp only [map_sum, mul_sum, sum_mul, ← sum_sub_distrib]
apply sum_congr rfl
intro i hi
rw [mem_range] at hi
rw [← IH i hi]
clear IH
rw [add_comm (X i ^ p), add_pow, sum_range_succ', pow_zero, tsub_zero, Nat.choose_zero_right,
one_mul, Nat.cast_one, mul_one, mul_add, add_mul, Nat.succ_sub (le_of_lt hi),
Nat.succ_eq_add_one (n - i), pow_succ', pow_mul, add_sub_cancel_right, mul_sum, sum_mul]
apply sum_congr rfl
intro j hj
rw [mem_range] at hj
rw [RingHom.map_mul, RingHom.map_mul, RingHom.map_pow, RingHom.map_pow, RingHom.map_pow,
RingHom.map_pow, RingHom.map_pow, map_C, map_X, mul_pow]
rw [mul_comm (C (p : ℚ) ^ i), mul_comm _ ((X i ^ p) ^ _), mul_comm (C (p : ℚ) ^ (j + 1)),
mul_comm (C (p : ℚ))]
simp only [mul_assoc]
apply congr_arg
apply congr_arg
rw [← C_eq_coe_nat]
simp only [← RingHom.map_pow, ← C_mul]
rw [C_inj]
simp only [invOf_eq_inv, eq_intCast, inv_pow, Int.cast_natCast, Nat.cast_mul, Int.cast_mul]
rw [Rat.natCast_div _ _ (map_frobeniusPoly.key₁ p (n - i) j hj)]
simp only [Nat.cast_pow, pow_add, pow_one]
suffices
(((p ^ (n - i)).choose (j + 1): ℚ) * (p : ℚ) ^ (j - v p ⟨j + 1, j.succ_pos⟩) * ↑p * (p ^ n : ℚ))
= (p : ℚ) ^ j * p * ↑((p ^ (n - i)).choose (j + 1) * p ^ i) *
(p : ℚ) ^ (n - i - v p ⟨j + 1, j.succ_pos⟩) by
have aux : ∀ k : ℕ, (p : ℚ)^ k ≠ 0 := by
intro; apply pow_ne_zero; exact mod_cast hp.1.ne_zero
simpa [aux, -one_div, -pow_eq_zero_iff', field_simps] using this.symm
rw [mul_comm _ (p : ℚ), mul_assoc, mul_assoc, ← pow_add,
map_frobeniusPoly.key₂ p hi.le hj, Nat.cast_mul, Nat.cast_pow]
ring
|
import Mathlib.Algebra.ContinuedFractions.ContinuantsRecurrence
import Mathlib.Algebra.ContinuedFractions.TerminatedStable
import Mathlib.Tactic.FieldSimp
import Mathlib.Tactic.Ring
#align_import algebra.continued_fractions.convergents_equiv from "leanprover-community/mathlib"@"a7e36e48519ab281320c4d192da6a7b348ce40ad"
variable {K : Type*} {n : ℕ}
namespace GeneralizedContinuedFraction
variable {g : GeneralizedContinuedFraction K} {s : Stream'.Seq <| Pair K}
section Squash
section WithDivisionRing
variable [DivisionRing K]
def squashSeq (s : Stream'.Seq <| Pair K) (n : ℕ) : Stream'.Seq (Pair K) :=
match Prod.mk (s.get? n) (s.get? (n + 1)) with
| ⟨some gp_n, some gp_succ_n⟩ =>
Stream'.Seq.nats.zipWith
-- return the squashed value at position `n`; otherwise, do nothing.
(fun n' gp => if n' = n then ⟨gp_n.a, gp_n.b + gp_succ_n.a / gp_succ_n.b⟩ else gp) s
| _ => s
#align generalized_continued_fraction.squash_seq GeneralizedContinuedFraction.squashSeq
theorem squashSeq_eq_self_of_terminated (terminated_at_succ_n : s.TerminatedAt (n + 1)) :
squashSeq s n = s := by
change s.get? (n + 1) = none at terminated_at_succ_n
cases s_nth_eq : s.get? n <;> simp only [*, squashSeq]
#align generalized_continued_fraction.squash_seq_eq_self_of_terminated GeneralizedContinuedFraction.squashSeq_eq_self_of_terminated
theorem squashSeq_nth_of_not_terminated {gp_n gp_succ_n : Pair K} (s_nth_eq : s.get? n = some gp_n)
(s_succ_nth_eq : s.get? (n + 1) = some gp_succ_n) :
(squashSeq s n).get? n = some ⟨gp_n.a, gp_n.b + gp_succ_n.a / gp_succ_n.b⟩ := by
simp [*, squashSeq]
#align generalized_continued_fraction.squash_seq_nth_of_not_terminated GeneralizedContinuedFraction.squashSeq_nth_of_not_terminated
theorem squashSeq_nth_of_lt {m : ℕ} (m_lt_n : m < n) : (squashSeq s n).get? m = s.get? m := by
cases s_succ_nth_eq : s.get? (n + 1) with
| none => rw [squashSeq_eq_self_of_terminated s_succ_nth_eq]
| some =>
obtain ⟨gp_n, s_nth_eq⟩ : ∃ gp_n, s.get? n = some gp_n :=
s.ge_stable n.le_succ s_succ_nth_eq
obtain ⟨gp_m, s_mth_eq⟩ : ∃ gp_m, s.get? m = some gp_m :=
s.ge_stable (le_of_lt m_lt_n) s_nth_eq
simp [*, squashSeq, m_lt_n.ne]
#align generalized_continued_fraction.squash_seq_nth_of_lt GeneralizedContinuedFraction.squashSeq_nth_of_lt
theorem squashSeq_succ_n_tail_eq_squashSeq_tail_n :
(squashSeq s (n + 1)).tail = squashSeq s.tail n := by
cases s_succ_succ_nth_eq : s.get? (n + 2) with
| none =>
cases s_succ_nth_eq : s.get? (n + 1) <;>
simp only [squashSeq, Stream'.Seq.get?_tail, s_succ_nth_eq, s_succ_succ_nth_eq]
| some gp_succ_succ_n =>
obtain ⟨gp_succ_n, s_succ_nth_eq⟩ : ∃ gp_succ_n, s.get? (n + 1) = some gp_succ_n :=
s.ge_stable (n + 1).le_succ s_succ_succ_nth_eq
-- apply extensionality with `m` and continue by cases `m = n`.
ext1 m
cases' Decidable.em (m = n) with m_eq_n m_ne_n
· simp [*, squashSeq]
· cases s_succ_mth_eq : s.get? (m + 1)
· simp only [*, squashSeq, Stream'.Seq.get?_tail, Stream'.Seq.get?_zipWith,
Option.map₂_none_right]
· simp [*, squashSeq]
#align generalized_continued_fraction.squash_seq_succ_n_tail_eq_squash_seq_tail_n GeneralizedContinuedFraction.squashSeq_succ_n_tail_eq_squashSeq_tail_n
theorem succ_succ_nth_convergent'_aux_eq_succ_nth_convergent'_aux_squashSeq :
convergents'Aux s (n + 2) = convergents'Aux (squashSeq s n) (n + 1) := by
cases s_succ_nth_eq : s.get? <| n + 1 with
| none =>
rw [squashSeq_eq_self_of_terminated s_succ_nth_eq,
convergents'Aux_stable_step_of_terminated s_succ_nth_eq]
| some gp_succ_n =>
induction n generalizing s gp_succ_n with
| zero =>
obtain ⟨gp_head, s_head_eq⟩ : ∃ gp_head, s.head = some gp_head :=
s.ge_stable zero_le_one s_succ_nth_eq
have : (squashSeq s 0).head = some ⟨gp_head.a, gp_head.b + gp_succ_n.a / gp_succ_n.b⟩ :=
squashSeq_nth_of_not_terminated s_head_eq s_succ_nth_eq
simp_all [convergents'Aux, Stream'.Seq.head, Stream'.Seq.get?_tail]
| succ m IH =>
obtain ⟨gp_head, s_head_eq⟩ : ∃ gp_head, s.head = some gp_head :=
s.ge_stable (m + 2).zero_le s_succ_nth_eq
suffices
gp_head.a / (gp_head.b + convergents'Aux s.tail (m + 2)) =
convergents'Aux (squashSeq s (m + 1)) (m + 2)
by simpa only [convergents'Aux, s_head_eq]
have : convergents'Aux s.tail (m + 2) = convergents'Aux (squashSeq s.tail m) (m + 1) := by
refine IH gp_succ_n ?_
simpa [Stream'.Seq.get?_tail] using s_succ_nth_eq
have : (squashSeq s (m + 1)).head = some gp_head :=
(squashSeq_nth_of_lt m.succ_pos).trans s_head_eq
simp_all [convergents'Aux, squashSeq_succ_n_tail_eq_squashSeq_tail_n]
#align generalized_continued_fraction.succ_succ_nth_convergent'_aux_eq_succ_nth_convergent'_aux_squash_seq GeneralizedContinuedFraction.succ_succ_nth_convergent'_aux_eq_succ_nth_convergent'_aux_squashSeq
def squashGCF (g : GeneralizedContinuedFraction K) : ℕ → GeneralizedContinuedFraction K
| 0 =>
match g.s.get? 0 with
| none => g
| some gp => ⟨g.h + gp.a / gp.b, g.s⟩
| n + 1 => ⟨g.h, squashSeq g.s n⟩
#align generalized_continued_fraction.squash_gcf GeneralizedContinuedFraction.squashGCF
| Mathlib/Algebra/ContinuedFractions/ConvergentsEquiv.lean | 204 | 213 | theorem squashGCF_eq_self_of_terminated (terminated_at_n : TerminatedAt g n) :
squashGCF g n = g := by |
cases n with
| zero =>
change g.s.get? 0 = none at terminated_at_n
simp only [convergents', squashGCF, convergents'Aux, terminated_at_n]
| succ =>
cases g
simp only [squashGCF, mk.injEq, true_and]
exact squashSeq_eq_self_of_terminated terminated_at_n
|
import Mathlib.Analysis.Convex.Cone.Basic
import Mathlib.Analysis.InnerProductSpace.Projection
#align_import analysis.convex.cone.dual from "leanprover-community/mathlib"@"915591b2bb3ea303648db07284a161a7f2a9e3d4"
open Set LinearMap
open scoped Classical
open Pointwise
variable {𝕜 E F G : Type*}
section Dual
variable {H : Type*} [NormedAddCommGroup H] [InnerProductSpace ℝ H] (s t : Set H)
open RealInnerProductSpace
def Set.innerDualCone (s : Set H) : ConvexCone ℝ H where
carrier := { y | ∀ x ∈ s, 0 ≤ ⟪x, y⟫ }
smul_mem' c hc y hy x hx := by
rw [real_inner_smul_right]
exact mul_nonneg hc.le (hy x hx)
add_mem' u hu v hv x hx := by
rw [inner_add_right]
exact add_nonneg (hu x hx) (hv x hx)
#align set.inner_dual_cone Set.innerDualCone
@[simp]
theorem mem_innerDualCone (y : H) (s : Set H) : y ∈ s.innerDualCone ↔ ∀ x ∈ s, 0 ≤ ⟪x, y⟫ :=
Iff.rfl
#align mem_inner_dual_cone mem_innerDualCone
@[simp]
theorem innerDualCone_empty : (∅ : Set H).innerDualCone = ⊤ :=
eq_top_iff.mpr fun _ _ _ => False.elim
#align inner_dual_cone_empty innerDualCone_empty
@[simp]
theorem innerDualCone_zero : (0 : Set H).innerDualCone = ⊤ :=
eq_top_iff.mpr fun _ _ y (hy : y = 0) => hy.symm ▸ (inner_zero_left _).ge
#align inner_dual_cone_zero innerDualCone_zero
@[simp]
theorem innerDualCone_univ : (univ : Set H).innerDualCone = 0 := by
suffices ∀ x : H, x ∈ (univ : Set H).innerDualCone → x = 0 by
apply SetLike.coe_injective
exact eq_singleton_iff_unique_mem.mpr ⟨fun x _ => (inner_zero_right _).ge, this⟩
exact fun x hx => by simpa [← real_inner_self_nonpos] using hx (-x) (mem_univ _)
#align inner_dual_cone_univ innerDualCone_univ
theorem innerDualCone_le_innerDualCone (h : t ⊆ s) : s.innerDualCone ≤ t.innerDualCone :=
fun _ hy x hx => hy x (h hx)
#align inner_dual_cone_le_inner_dual_cone innerDualCone_le_innerDualCone
theorem pointed_innerDualCone : s.innerDualCone.Pointed := fun x _ => by rw [inner_zero_right]
#align pointed_inner_dual_cone pointed_innerDualCone
theorem innerDualCone_singleton (x : H) :
({x} : Set H).innerDualCone = (ConvexCone.positive ℝ ℝ).comap (innerₛₗ ℝ x) :=
ConvexCone.ext fun _ => forall_eq
#align inner_dual_cone_singleton innerDualCone_singleton
theorem innerDualCone_union (s t : Set H) :
(s ∪ t).innerDualCone = s.innerDualCone ⊓ t.innerDualCone :=
le_antisymm (le_inf (fun _ hx _ hy => hx _ <| Or.inl hy) fun _ hx _ hy => hx _ <| Or.inr hy)
fun _ hx _ => Or.rec (hx.1 _) (hx.2 _)
#align inner_dual_cone_union innerDualCone_union
theorem innerDualCone_insert (x : H) (s : Set H) :
(insert x s).innerDualCone = Set.innerDualCone {x} ⊓ s.innerDualCone := by
rw [insert_eq, innerDualCone_union]
#align inner_dual_cone_insert innerDualCone_insert
| Mathlib/Analysis/Convex/Cone/InnerDual.lean | 110 | 116 | theorem innerDualCone_iUnion {ι : Sort*} (f : ι → Set H) :
(⋃ i, f i).innerDualCone = ⨅ i, (f i).innerDualCone := by |
refine le_antisymm (le_iInf fun i x hx y hy => hx _ <| mem_iUnion_of_mem _ hy) ?_
intro x hx y hy
rw [ConvexCone.mem_iInf] at hx
obtain ⟨j, hj⟩ := mem_iUnion.mp hy
exact hx _ _ hj
|
import Mathlib.SetTheory.Game.Basic
import Mathlib.SetTheory.Ordinal.NaturalOps
#align_import set_theory.game.ordinal from "leanprover-community/mathlib"@"b90e72c7eebbe8de7c8293a80208ea2ba135c834"
universe u
open SetTheory PGame
open scoped NaturalOps PGame
namespace Ordinal
noncomputable def toPGame : Ordinal.{u} → PGame.{u}
| o =>
have : IsWellOrder o.out.α (· < ·) := isWellOrder_out_lt o
⟨o.out.α, PEmpty, fun x =>
have := Ordinal.typein_lt_self x
(typein (· < ·) x).toPGame,
PEmpty.elim⟩
termination_by x => x
#align ordinal.to_pgame Ordinal.toPGame
@[nolint unusedHavesSuffices]
theorem toPGame_def (o : Ordinal) :
have : IsWellOrder o.out.α (· < ·) := isWellOrder_out_lt o
o.toPGame = ⟨o.out.α, PEmpty, fun x => (typein (· < ·) x).toPGame, PEmpty.elim⟩ := by
rw [toPGame]
#align ordinal.to_pgame_def Ordinal.toPGame_def
@[simp, nolint unusedHavesSuffices]
theorem toPGame_leftMoves (o : Ordinal) : o.toPGame.LeftMoves = o.out.α := by
rw [toPGame, LeftMoves]
#align ordinal.to_pgame_left_moves Ordinal.toPGame_leftMoves
@[simp, nolint unusedHavesSuffices]
theorem toPGame_rightMoves (o : Ordinal) : o.toPGame.RightMoves = PEmpty := by
rw [toPGame, RightMoves]
#align ordinal.to_pgame_right_moves Ordinal.toPGame_rightMoves
instance isEmpty_zero_toPGame_leftMoves : IsEmpty (toPGame 0).LeftMoves := by
rw [toPGame_leftMoves]; infer_instance
#align ordinal.is_empty_zero_to_pgame_left_moves Ordinal.isEmpty_zero_toPGame_leftMoves
instance isEmpty_toPGame_rightMoves (o : Ordinal) : IsEmpty o.toPGame.RightMoves := by
rw [toPGame_rightMoves]; infer_instance
#align ordinal.is_empty_to_pgame_right_moves Ordinal.isEmpty_toPGame_rightMoves
noncomputable def toLeftMovesToPGame {o : Ordinal} : Set.Iio o ≃ o.toPGame.LeftMoves :=
(enumIsoOut o).toEquiv.trans (Equiv.cast (toPGame_leftMoves o).symm)
#align ordinal.to_left_moves_to_pgame Ordinal.toLeftMovesToPGame
@[simp]
theorem toLeftMovesToPGame_symm_lt {o : Ordinal} (i : o.toPGame.LeftMoves) :
↑(toLeftMovesToPGame.symm i) < o :=
(toLeftMovesToPGame.symm i).prop
#align ordinal.to_left_moves_to_pgame_symm_lt Ordinal.toLeftMovesToPGame_symm_lt
@[nolint unusedHavesSuffices]
theorem toPGame_moveLeft_hEq {o : Ordinal} :
have : IsWellOrder o.out.α (· < ·) := isWellOrder_out_lt o
HEq o.toPGame.moveLeft fun x : o.out.α => (typein (· < ·) x).toPGame := by
rw [toPGame]
rfl
#align ordinal.to_pgame_move_left_heq Ordinal.toPGame_moveLeft_hEq
@[simp]
theorem toPGame_moveLeft' {o : Ordinal} (i) :
o.toPGame.moveLeft i = (toLeftMovesToPGame.symm i).val.toPGame :=
(congr_heq toPGame_moveLeft_hEq.symm (cast_heq _ i)).symm
#align ordinal.to_pgame_move_left' Ordinal.toPGame_moveLeft'
theorem toPGame_moveLeft {o : Ordinal} (i) :
o.toPGame.moveLeft (toLeftMovesToPGame i) = i.val.toPGame := by simp
#align ordinal.to_pgame_move_left Ordinal.toPGame_moveLeft
noncomputable def zeroToPGameRelabelling : toPGame 0 ≡r 0 :=
Relabelling.isEmpty _
#align ordinal.zero_to_pgame_relabelling Ordinal.zeroToPGameRelabelling
noncomputable instance uniqueOneToPGameLeftMoves : Unique (toPGame 1).LeftMoves :=
(Equiv.cast <| toPGame_leftMoves 1).unique
#align ordinal.unique_one_to_pgame_left_moves Ordinal.uniqueOneToPGameLeftMoves
@[simp]
theorem one_toPGame_leftMoves_default_eq :
(default : (toPGame 1).LeftMoves) = @toLeftMovesToPGame 1 ⟨0, Set.mem_Iio.mpr zero_lt_one⟩ :=
rfl
#align ordinal.one_to_pgame_left_moves_default_eq Ordinal.one_toPGame_leftMoves_default_eq
@[simp]
theorem to_leftMoves_one_toPGame_symm (i) :
(@toLeftMovesToPGame 1).symm i = ⟨0, Set.mem_Iio.mpr zero_lt_one⟩ := by
simp [eq_iff_true_of_subsingleton]
#align ordinal.to_left_moves_one_to_pgame_symm Ordinal.to_leftMoves_one_toPGame_symm
| Mathlib/SetTheory/Game/Ordinal.lean | 121 | 121 | theorem one_toPGame_moveLeft (x) : (toPGame 1).moveLeft x = toPGame 0 := by | simp
|
import Mathlib.Algebra.Polynomial.Reverse
import Mathlib.Algebra.Regular.SMul
#align_import data.polynomial.monic from "leanprover-community/mathlib"@"cbdf7b565832144d024caa5a550117c6df0204a5"
noncomputable section
open Finset
open Polynomial
namespace Polynomial
universe u v y
variable {R : Type u} {S : Type v} {a b : R} {m n : ℕ} {ι : Type y}
section Semiring
variable [Semiring R] {p q r : R[X]}
theorem monic_zero_iff_subsingleton : Monic (0 : R[X]) ↔ Subsingleton R :=
subsingleton_iff_zero_eq_one
#align polynomial.monic_zero_iff_subsingleton Polynomial.monic_zero_iff_subsingleton
theorem not_monic_zero_iff : ¬Monic (0 : R[X]) ↔ (0 : R) ≠ 1 :=
(monic_zero_iff_subsingleton.trans subsingleton_iff_zero_eq_one.symm).not
#align polynomial.not_monic_zero_iff Polynomial.not_monic_zero_iff
theorem monic_zero_iff_subsingleton' :
Monic (0 : R[X]) ↔ (∀ f g : R[X], f = g) ∧ ∀ a b : R, a = b :=
Polynomial.monic_zero_iff_subsingleton.trans
⟨by
intro
simp [eq_iff_true_of_subsingleton], fun h => subsingleton_iff.mpr h.2⟩
#align polynomial.monic_zero_iff_subsingleton' Polynomial.monic_zero_iff_subsingleton'
theorem Monic.as_sum (hp : p.Monic) :
p = X ^ p.natDegree + ∑ i ∈ range p.natDegree, C (p.coeff i) * X ^ i := by
conv_lhs => rw [p.as_sum_range_C_mul_X_pow, sum_range_succ_comm]
suffices C (p.coeff p.natDegree) = 1 by rw [this, one_mul]
exact congr_arg C hp
#align polynomial.monic.as_sum Polynomial.Monic.as_sum
theorem ne_zero_of_ne_zero_of_monic (hp : p ≠ 0) (hq : Monic q) : q ≠ 0 := by
rintro rfl
rw [Monic.def, leadingCoeff_zero] at hq
rw [← mul_one p, ← C_1, ← hq, C_0, mul_zero] at hp
exact hp rfl
#align polynomial.ne_zero_of_ne_zero_of_monic Polynomial.ne_zero_of_ne_zero_of_monic
theorem Monic.map [Semiring S] (f : R →+* S) (hp : Monic p) : Monic (p.map f) := by
unfold Monic
nontriviality
have : f p.leadingCoeff ≠ 0 := by
rw [show _ = _ from hp, f.map_one]
exact one_ne_zero
rw [Polynomial.leadingCoeff, coeff_map]
suffices p.coeff (p.map f).natDegree = 1 by simp [this]
rwa [natDegree_eq_of_degree_eq (degree_map_eq_of_leadingCoeff_ne_zero f this)]
#align polynomial.monic.map Polynomial.Monic.map
| Mathlib/Algebra/Polynomial/Monic.lean | 76 | 80 | theorem monic_C_mul_of_mul_leadingCoeff_eq_one {b : R} (hp : b * p.leadingCoeff = 1) :
Monic (C b * p) := by |
unfold Monic
nontriviality
rw [leadingCoeff_mul' _] <;> simp [leadingCoeff_C b, hp]
|
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
| Mathlib/Data/Set/Basic.lean | 1,958 | 1,960 | 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]
|
import Mathlib.Algebra.Polynomial.BigOperators
import Mathlib.Algebra.Polynomial.Degree.Lemmas
import Mathlib.LinearAlgebra.Matrix.Determinant.Basic
import Mathlib.Tactic.ComputeDegree
#align_import linear_algebra.matrix.polynomial from "leanprover-community/mathlib"@"70fd9563a21e7b963887c9360bd29b2393e6225a"
set_option linter.uppercaseLean3 false
open Matrix Polynomial
variable {n α : Type*} [DecidableEq n] [Fintype n] [CommRing α]
open Polynomial Matrix Equiv.Perm
namespace Polynomial
| Mathlib/LinearAlgebra/Matrix/Polynomial.lean | 39 | 59 | theorem natDegree_det_X_add_C_le (A B : Matrix n n α) :
natDegree (det ((X : α[X]) • A.map C + B.map C : Matrix n n α[X])) ≤ Fintype.card n := by |
rw [det_apply]
refine (natDegree_sum_le _ _).trans ?_
refine Multiset.max_le_of_forall_le _ _ ?_
simp only [forall_apply_eq_imp_iff, true_and_iff, Function.comp_apply, Multiset.map_map,
Multiset.mem_map, exists_imp, Finset.mem_univ_val]
intro g
calc
natDegree (sign g • ∏ i : n, (X • A.map C + B.map C : Matrix n n α[X]) (g i) i) ≤
natDegree (∏ i : n, (X • A.map C + B.map C : Matrix n n α[X]) (g i) i) := by
cases' Int.units_eq_one_or (sign g) with sg sg
· rw [sg, one_smul]
· rw [sg, Units.neg_smul, one_smul, natDegree_neg]
_ ≤ ∑ i : n, natDegree (((X : α[X]) • A.map C + B.map C : Matrix n n α[X]) (g i) i) :=
(natDegree_prod_le (Finset.univ : Finset n) fun i : n =>
(X • A.map C + B.map C : Matrix n n α[X]) (g i) i)
_ ≤ Finset.univ.card • 1 := (Finset.sum_le_card_nsmul _ _ 1 fun (i : n) _ => ?_)
_ ≤ Fintype.card n := by simp [mul_one, Algebra.id.smul_eq_mul, Finset.card_univ]
dsimp only [add_apply, smul_apply, map_apply, smul_eq_mul]
compute_degree
|
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