Context stringlengths 57 85k | file_name stringlengths 21 79 | start int64 14 2.42k | end int64 18 2.43k | theorem stringlengths 25 2.71k | proof stringlengths 5 10.6k |
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import Mathlib.Analysis.InnerProductSpace.PiL2
import Mathlib.LinearAlgebra.Matrix.Block
#align_import analysis.inner_product_space.gram_schmidt_ortho from "leanprover-community/mathlib"@"1a4df69ca1a9a0e5e26bfe12e2b92814216016d0"
open Finset Submodule FiniteDimensional
variable (𝕜 : Type*) {E : Type*} [RCLike 𝕜] [NormedAddCommGroup E] [InnerProductSpace 𝕜 E]
variable {ι : Type*} [LinearOrder ι] [LocallyFiniteOrderBot ι] [IsWellOrder ι (· < ·)]
attribute [local instance] IsWellOrder.toHasWellFounded
local notation "⟪" x ", " y "⟫" => @inner 𝕜 _ _ x y
noncomputable def gramSchmidt [IsWellOrder ι (· < ·)] (f : ι → E) (n : ι) : E :=
f n - ∑ i : Iio n, orthogonalProjection (𝕜 ∙ gramSchmidt f i) (f n)
termination_by n
decreasing_by exact mem_Iio.1 i.2
#align gram_schmidt gramSchmidt
theorem gramSchmidt_def (f : ι → E) (n : ι) :
gramSchmidt 𝕜 f n = f n - ∑ i ∈ Iio n, orthogonalProjection (𝕜 ∙ gramSchmidt 𝕜 f i) (f n) := by
rw [← sum_attach, attach_eq_univ, gramSchmidt]
#align gram_schmidt_def gramSchmidt_def
theorem gramSchmidt_def' (f : ι → E) (n : ι) :
f n = gramSchmidt 𝕜 f n + ∑ i ∈ Iio n, orthogonalProjection (𝕜 ∙ gramSchmidt 𝕜 f i) (f n) := by
rw [gramSchmidt_def, sub_add_cancel]
#align gram_schmidt_def' gramSchmidt_def'
theorem gramSchmidt_def'' (f : ι → E) (n : ι) :
f n = gramSchmidt 𝕜 f n + ∑ i ∈ Iio n,
(⟪gramSchmidt 𝕜 f i, f n⟫ / (‖gramSchmidt 𝕜 f i‖ : 𝕜) ^ 2) • gramSchmidt 𝕜 f i := by
convert gramSchmidt_def' 𝕜 f n
rw [orthogonalProjection_singleton, RCLike.ofReal_pow]
#align gram_schmidt_def'' gramSchmidt_def''
@[simp]
theorem gramSchmidt_zero {ι : Type*} [LinearOrder ι] [LocallyFiniteOrder ι] [OrderBot ι]
[IsWellOrder ι (· < ·)] (f : ι → E) : gramSchmidt 𝕜 f ⊥ = f ⊥ := by
rw [gramSchmidt_def, Iio_eq_Ico, Finset.Ico_self, Finset.sum_empty, sub_zero]
#align gram_schmidt_zero gramSchmidt_zero
theorem gramSchmidt_orthogonal (f : ι → E) {a b : ι} (h₀ : a ≠ b) :
⟪gramSchmidt 𝕜 f a, gramSchmidt 𝕜 f b⟫ = 0 := by
suffices ∀ a b : ι, a < b → ⟪gramSchmidt 𝕜 f a, gramSchmidt 𝕜 f b⟫ = 0 by
cases' h₀.lt_or_lt with ha hb
· exact this _ _ ha
· rw [inner_eq_zero_symm]
exact this _ _ hb
clear h₀ a b
intro a b h₀
revert a
apply wellFounded_lt.induction b
intro b ih a h₀
simp only [gramSchmidt_def 𝕜 f b, inner_sub_right, inner_sum, orthogonalProjection_singleton,
inner_smul_right]
rw [Finset.sum_eq_single_of_mem a (Finset.mem_Iio.mpr h₀)]
· by_cases h : gramSchmidt 𝕜 f a = 0
· simp only [h, inner_zero_left, zero_div, zero_mul, sub_zero]
· rw [RCLike.ofReal_pow, ← inner_self_eq_norm_sq_to_K, div_mul_cancel₀, sub_self]
rwa [inner_self_ne_zero]
intro i hi hia
simp only [mul_eq_zero, div_eq_zero_iff, inner_self_eq_zero]
right
cases' hia.lt_or_lt with hia₁ hia₂
· rw [inner_eq_zero_symm]
exact ih a h₀ i hia₁
· exact ih i (mem_Iio.1 hi) a hia₂
#align gram_schmidt_orthogonal gramSchmidt_orthogonal
theorem gramSchmidt_pairwise_orthogonal (f : ι → E) :
Pairwise fun a b => ⟪gramSchmidt 𝕜 f a, gramSchmidt 𝕜 f b⟫ = 0 := fun _ _ =>
gramSchmidt_orthogonal 𝕜 f
#align gram_schmidt_pairwise_orthogonal gramSchmidt_pairwise_orthogonal
theorem gramSchmidt_inv_triangular (v : ι → E) {i j : ι} (hij : i < j) :
⟪gramSchmidt 𝕜 v j, v i⟫ = 0 := by
rw [gramSchmidt_def'' 𝕜 v]
simp only [inner_add_right, inner_sum, inner_smul_right]
set b : ι → E := gramSchmidt 𝕜 v
convert zero_add (0 : 𝕜)
· exact gramSchmidt_orthogonal 𝕜 v hij.ne'
apply Finset.sum_eq_zero
rintro k hki'
have hki : k < i := by simpa using hki'
have : ⟪b j, b k⟫ = 0 := gramSchmidt_orthogonal 𝕜 v (hki.trans hij).ne'
simp [this]
#align gram_schmidt_inv_triangular gramSchmidt_inv_triangular
open Submodule Set Order
theorem mem_span_gramSchmidt (f : ι → E) {i j : ι} (hij : i ≤ j) :
f i ∈ span 𝕜 (gramSchmidt 𝕜 f '' Set.Iic j) := by
rw [gramSchmidt_def' 𝕜 f i]
simp_rw [orthogonalProjection_singleton]
exact Submodule.add_mem _ (subset_span <| mem_image_of_mem _ hij)
(Submodule.sum_mem _ fun k hk => smul_mem (span 𝕜 (gramSchmidt 𝕜 f '' Set.Iic j)) _ <|
subset_span <| mem_image_of_mem (gramSchmidt 𝕜 f) <| (Finset.mem_Iio.1 hk).le.trans hij)
#align mem_span_gram_schmidt mem_span_gramSchmidt
theorem gramSchmidt_mem_span (f : ι → E) :
∀ {j i}, i ≤ j → gramSchmidt 𝕜 f i ∈ span 𝕜 (f '' Set.Iic j) := by
intro j i hij
rw [gramSchmidt_def 𝕜 f i]
simp_rw [orthogonalProjection_singleton]
refine Submodule.sub_mem _ (subset_span (mem_image_of_mem _ hij))
(Submodule.sum_mem _ fun k hk => ?_)
let hkj : k < j := (Finset.mem_Iio.1 hk).trans_le hij
exact smul_mem _ _
(span_mono (image_subset f <| Iic_subset_Iic.2 hkj.le) <| gramSchmidt_mem_span _ le_rfl)
termination_by j => j
#align gram_schmidt_mem_span gramSchmidt_mem_span
theorem span_gramSchmidt_Iic (f : ι → E) (c : ι) :
span 𝕜 (gramSchmidt 𝕜 f '' Set.Iic c) = span 𝕜 (f '' Set.Iic c) :=
span_eq_span (Set.image_subset_iff.2 fun _ => gramSchmidt_mem_span _ _) <|
Set.image_subset_iff.2 fun _ => mem_span_gramSchmidt _ _
#align span_gram_schmidt_Iic span_gramSchmidt_Iic
theorem span_gramSchmidt_Iio (f : ι → E) (c : ι) :
span 𝕜 (gramSchmidt 𝕜 f '' Set.Iio c) = span 𝕜 (f '' Set.Iio c) :=
span_eq_span (Set.image_subset_iff.2 fun _ hi =>
span_mono (image_subset _ <| Iic_subset_Iio.2 hi) <| gramSchmidt_mem_span _ _ le_rfl) <|
Set.image_subset_iff.2 fun _ hi =>
span_mono (image_subset _ <| Iic_subset_Iio.2 hi) <| mem_span_gramSchmidt _ _ le_rfl
#align span_gram_schmidt_Iio span_gramSchmidt_Iio
theorem span_gramSchmidt (f : ι → E) : span 𝕜 (range (gramSchmidt 𝕜 f)) = span 𝕜 (range f) :=
span_eq_span (range_subset_iff.2 fun _ =>
span_mono (image_subset_range _ _) <| gramSchmidt_mem_span _ _ le_rfl) <|
range_subset_iff.2 fun _ =>
span_mono (image_subset_range _ _) <| mem_span_gramSchmidt _ _ le_rfl
#align span_gram_schmidt span_gramSchmidt
| Mathlib/Analysis/InnerProductSpace/GramSchmidtOrtho.lean | 177 | 195 | theorem gramSchmidt_of_orthogonal {f : ι → E} (hf : Pairwise fun i j => ⟪f i, f j⟫ = 0) :
gramSchmidt 𝕜 f = f := by |
ext i
rw [gramSchmidt_def]
trans f i - 0
· congr
apply Finset.sum_eq_zero
intro j hj
rw [Submodule.coe_eq_zero]
suffices span 𝕜 (f '' Set.Iic j) ⟂ 𝕜 ∙ f i by
apply orthogonalProjection_mem_subspace_orthogonalComplement_eq_zero
rw [mem_orthogonal_singleton_iff_inner_left]
rw [← mem_orthogonal_singleton_iff_inner_right]
exact this (gramSchmidt_mem_span 𝕜 f (le_refl j))
rw [isOrtho_span]
rintro u ⟨k, hk, rfl⟩ v (rfl : v = f i)
apply hf
exact (lt_of_le_of_lt hk (Finset.mem_Iio.mp hj)).ne
· simp
|
import Mathlib.MeasureTheory.Measure.Content
import Mathlib.MeasureTheory.Group.Prod
import Mathlib.Topology.Algebra.Group.Compact
#align_import measure_theory.measure.haar.basic from "leanprover-community/mathlib"@"fd5edc43dc4f10b85abfe544b88f82cf13c5f844"
noncomputable section
open Set Inv Function TopologicalSpace MeasurableSpace
open scoped NNReal Classical ENNReal Pointwise Topology
namespace MeasureTheory
namespace Measure
section Group
variable {G : Type*} [Group G]
namespace haar
-- Porting note: Even in `noncomputable section`, a definition with `to_additive` require
-- `noncomputable` to generate an additive definition.
-- Please refer to leanprover/lean4#2077.
@[to_additive addIndex "additive version of `MeasureTheory.Measure.haar.index`"]
noncomputable def index (K V : Set G) : ℕ :=
sInf <| Finset.card '' { t : Finset G | K ⊆ ⋃ g ∈ t, (fun h => g * h) ⁻¹' V }
#align measure_theory.measure.haar.index MeasureTheory.Measure.haar.index
#align measure_theory.measure.haar.add_index MeasureTheory.Measure.haar.addIndex
@[to_additive addIndex_empty]
theorem index_empty {V : Set G} : index ∅ V = 0 := by
simp only [index, Nat.sInf_eq_zero]; left; use ∅
simp only [Finset.card_empty, empty_subset, mem_setOf_eq, eq_self_iff_true, and_self_iff]
#align measure_theory.measure.haar.index_empty MeasureTheory.Measure.haar.index_empty
#align measure_theory.measure.haar.add_index_empty MeasureTheory.Measure.haar.addIndex_empty
variable [TopologicalSpace G]
@[to_additive "additive version of `MeasureTheory.Measure.haar.prehaar`"]
noncomputable def prehaar (K₀ U : Set G) (K : Compacts G) : ℝ :=
(index (K : Set G) U : ℝ) / index K₀ U
#align measure_theory.measure.haar.prehaar MeasureTheory.Measure.haar.prehaar
#align measure_theory.measure.haar.add_prehaar MeasureTheory.Measure.haar.addPrehaar
@[to_additive]
theorem prehaar_empty (K₀ : PositiveCompacts G) {U : Set G} : prehaar (K₀ : Set G) U ⊥ = 0 := by
rw [prehaar, Compacts.coe_bot, index_empty, Nat.cast_zero, zero_div]
#align measure_theory.measure.haar.prehaar_empty MeasureTheory.Measure.haar.prehaar_empty
#align measure_theory.measure.haar.add_prehaar_empty MeasureTheory.Measure.haar.addPrehaar_empty
@[to_additive]
theorem prehaar_nonneg (K₀ : PositiveCompacts G) {U : Set G} (K : Compacts G) :
0 ≤ prehaar (K₀ : Set G) U K := by apply div_nonneg <;> norm_cast <;> apply zero_le
#align measure_theory.measure.haar.prehaar_nonneg MeasureTheory.Measure.haar.prehaar_nonneg
#align measure_theory.measure.haar.add_prehaar_nonneg MeasureTheory.Measure.haar.addPrehaar_nonneg
@[to_additive "additive version of `MeasureTheory.Measure.haar.haarProduct`"]
def haarProduct (K₀ : Set G) : Set (Compacts G → ℝ) :=
pi univ fun K => Icc 0 <| index (K : Set G) K₀
#align measure_theory.measure.haar.haar_product MeasureTheory.Measure.haar.haarProduct
#align measure_theory.measure.haar.add_haar_product MeasureTheory.Measure.haar.addHaarProduct
@[to_additive (attr := simp)]
theorem mem_prehaar_empty {K₀ : Set G} {f : Compacts G → ℝ} :
f ∈ haarProduct K₀ ↔ ∀ K : Compacts G, f K ∈ Icc (0 : ℝ) (index (K : Set G) K₀) := by
simp only [haarProduct, Set.pi, forall_prop_of_true, mem_univ, mem_setOf_eq]
#align measure_theory.measure.haar.mem_prehaar_empty MeasureTheory.Measure.haar.mem_prehaar_empty
#align measure_theory.measure.haar.mem_add_prehaar_empty MeasureTheory.Measure.haar.mem_addPrehaar_empty
@[to_additive "additive version of `MeasureTheory.Measure.haar.clPrehaar`"]
def clPrehaar (K₀ : Set G) (V : OpenNhdsOf (1 : G)) : Set (Compacts G → ℝ) :=
closure <| prehaar K₀ '' { U : Set G | U ⊆ V.1 ∧ IsOpen U ∧ (1 : G) ∈ U }
#align measure_theory.measure.haar.cl_prehaar MeasureTheory.Measure.haar.clPrehaar
#align measure_theory.measure.haar.cl_add_prehaar MeasureTheory.Measure.haar.clAddPrehaar
variable [TopologicalGroup G]
@[to_additive addIndex_defined
"If `K` is compact and `V` has nonempty interior, then the index `(K : V)` is well-defined, there is
a finite set `t` satisfying the desired properties."]
theorem index_defined {K V : Set G} (hK : IsCompact K) (hV : (interior V).Nonempty) :
∃ n : ℕ, n ∈ Finset.card '' { t : Finset G | K ⊆ ⋃ g ∈ t, (fun h => g * h) ⁻¹' V } := by
rcases compact_covered_by_mul_left_translates hK hV with ⟨t, ht⟩; exact ⟨t.card, t, ht, rfl⟩
#align measure_theory.measure.haar.index_defined MeasureTheory.Measure.haar.index_defined
#align measure_theory.measure.haar.add_index_defined MeasureTheory.Measure.haar.addIndex_defined
@[to_additive addIndex_elim]
theorem index_elim {K V : Set G} (hK : IsCompact K) (hV : (interior V).Nonempty) :
∃ t : Finset G, (K ⊆ ⋃ g ∈ t, (fun h => g * h) ⁻¹' V) ∧ Finset.card t = index K V := by
have := Nat.sInf_mem (index_defined hK hV); rwa [mem_image] at this
#align measure_theory.measure.haar.index_elim MeasureTheory.Measure.haar.index_elim
#align measure_theory.measure.haar.add_index_elim MeasureTheory.Measure.haar.addIndex_elim
@[to_additive le_addIndex_mul]
theorem le_index_mul (K₀ : PositiveCompacts G) (K : Compacts G) {V : Set G}
(hV : (interior V).Nonempty) :
index (K : Set G) V ≤ index (K : Set G) K₀ * index (K₀ : Set G) V := by
obtain ⟨s, h1s, h2s⟩ := index_elim K.isCompact K₀.interior_nonempty
obtain ⟨t, h1t, h2t⟩ := index_elim K₀.isCompact hV
rw [← h2s, ← h2t, mul_comm]
refine le_trans ?_ Finset.card_mul_le
apply Nat.sInf_le; refine ⟨_, ?_, rfl⟩; rw [mem_setOf_eq]; refine Subset.trans h1s ?_
apply iUnion₂_subset; intro g₁ hg₁; rw [preimage_subset_iff]; intro g₂ hg₂
have := h1t hg₂
rcases this with ⟨_, ⟨g₃, rfl⟩, A, ⟨hg₃, rfl⟩, h2V⟩; rw [mem_preimage, ← mul_assoc] at h2V
exact mem_biUnion (Finset.mul_mem_mul hg₃ hg₁) h2V
#align measure_theory.measure.haar.le_index_mul MeasureTheory.Measure.haar.le_index_mul
#align measure_theory.measure.haar.le_add_index_mul MeasureTheory.Measure.haar.le_addIndex_mul
@[to_additive addIndex_pos]
theorem index_pos (K : PositiveCompacts G) {V : Set G} (hV : (interior V).Nonempty) :
0 < index (K : Set G) V := by
unfold index; rw [Nat.sInf_def, Nat.find_pos, mem_image]
· rintro ⟨t, h1t, h2t⟩; rw [Finset.card_eq_zero] at h2t; subst h2t
obtain ⟨g, hg⟩ := K.interior_nonempty
show g ∈ (∅ : Set G)
convert h1t (interior_subset hg); symm
simp only [Finset.not_mem_empty, iUnion_of_empty, iUnion_empty]
· exact index_defined K.isCompact hV
#align measure_theory.measure.haar.index_pos MeasureTheory.Measure.haar.index_pos
#align measure_theory.measure.haar.add_index_pos MeasureTheory.Measure.haar.addIndex_pos
@[to_additive addIndex_mono]
theorem index_mono {K K' V : Set G} (hK' : IsCompact K') (h : K ⊆ K') (hV : (interior V).Nonempty) :
index K V ≤ index K' V := by
rcases index_elim hK' hV with ⟨s, h1s, h2s⟩
apply Nat.sInf_le; rw [mem_image]; exact ⟨s, Subset.trans h h1s, h2s⟩
#align measure_theory.measure.haar.index_mono MeasureTheory.Measure.haar.index_mono
#align measure_theory.measure.haar.add_index_mono MeasureTheory.Measure.haar.addIndex_mono
@[to_additive addIndex_union_le]
theorem index_union_le (K₁ K₂ : Compacts G) {V : Set G} (hV : (interior V).Nonempty) :
index (K₁.1 ∪ K₂.1) V ≤ index K₁.1 V + index K₂.1 V := by
rcases index_elim K₁.2 hV with ⟨s, h1s, h2s⟩
rcases index_elim K₂.2 hV with ⟨t, h1t, h2t⟩
rw [← h2s, ← h2t]
refine le_trans ?_ (Finset.card_union_le _ _)
apply Nat.sInf_le; refine ⟨_, ?_, rfl⟩; rw [mem_setOf_eq]
apply union_subset <;> refine Subset.trans (by assumption) ?_ <;>
apply biUnion_subset_biUnion_left <;> intro g hg <;> simp only [mem_def] at hg <;>
simp only [mem_def, Multiset.mem_union, Finset.union_val, hg, or_true_iff, true_or_iff]
#align measure_theory.measure.haar.index_union_le MeasureTheory.Measure.haar.index_union_le
#align measure_theory.measure.haar.add_index_union_le MeasureTheory.Measure.haar.addIndex_union_le
@[to_additive addIndex_union_eq]
theorem index_union_eq (K₁ K₂ : Compacts G) {V : Set G} (hV : (interior V).Nonempty)
(h : Disjoint (K₁.1 * V⁻¹) (K₂.1 * V⁻¹)) :
index (K₁.1 ∪ K₂.1) V = index K₁.1 V + index K₂.1 V := by
apply le_antisymm (index_union_le K₁ K₂ hV)
rcases index_elim (K₁.2.union K₂.2) hV with ⟨s, h1s, h2s⟩; rw [← h2s]
have :
∀ K : Set G,
(K ⊆ ⋃ g ∈ s, (fun h => g * h) ⁻¹' V) →
index K V ≤ (s.filter fun g => ((fun h : G => g * h) ⁻¹' V ∩ K).Nonempty).card := by
intro K hK; apply Nat.sInf_le; refine ⟨_, ?_, rfl⟩; rw [mem_setOf_eq]
intro g hg; rcases hK hg with ⟨_, ⟨g₀, rfl⟩, _, ⟨h1g₀, rfl⟩, h2g₀⟩
simp only [mem_preimage] at h2g₀
simp only [mem_iUnion]; use g₀; constructor; swap
· simp only [Finset.mem_filter, h1g₀, true_and_iff]; use g
simp only [hg, h2g₀, mem_inter_iff, mem_preimage, and_self_iff]
exact h2g₀
refine
le_trans
(add_le_add (this K₁.1 <| Subset.trans subset_union_left h1s)
(this K₂.1 <| Subset.trans subset_union_right h1s)) ?_
rw [← Finset.card_union_of_disjoint, Finset.filter_union_right]
· exact s.card_filter_le _
apply Finset.disjoint_filter.mpr
rintro g₁ _ ⟨g₂, h1g₂, h2g₂⟩ ⟨g₃, h1g₃, h2g₃⟩
simp only [mem_preimage] at h1g₃ h1g₂
refine h.le_bot (?_ : g₁⁻¹ ∈ _)
constructor <;> simp only [Set.mem_inv, Set.mem_mul, exists_exists_and_eq_and, exists_and_left]
· refine ⟨_, h2g₂, (g₁ * g₂)⁻¹, ?_, ?_⟩
· simp only [inv_inv, h1g₂]
· simp only [mul_inv_rev, mul_inv_cancel_left]
· refine ⟨_, h2g₃, (g₁ * g₃)⁻¹, ?_, ?_⟩
· simp only [inv_inv, h1g₃]
· simp only [mul_inv_rev, mul_inv_cancel_left]
#align measure_theory.measure.haar.index_union_eq MeasureTheory.Measure.haar.index_union_eq
#align measure_theory.measure.haar.add_index_union_eq MeasureTheory.Measure.haar.addIndex_union_eq
@[to_additive add_left_addIndex_le]
theorem mul_left_index_le {K : Set G} (hK : IsCompact K) {V : Set G} (hV : (interior V).Nonempty)
(g : G) : index ((fun h => g * h) '' K) V ≤ index K V := by
rcases index_elim hK hV with ⟨s, h1s, h2s⟩; rw [← h2s]
apply Nat.sInf_le; rw [mem_image]
refine ⟨s.map (Equiv.mulRight g⁻¹).toEmbedding, ?_, Finset.card_map _⟩
simp only [mem_setOf_eq]; refine Subset.trans (image_subset _ h1s) ?_
rintro _ ⟨g₁, ⟨_, ⟨g₂, rfl⟩, ⟨_, ⟨hg₂, rfl⟩, hg₁⟩⟩, rfl⟩
simp only [mem_preimage] at hg₁;
simp only [exists_prop, mem_iUnion, Finset.mem_map, Equiv.coe_mulRight,
exists_exists_and_eq_and, mem_preimage, Equiv.toEmbedding_apply]
refine ⟨_, hg₂, ?_⟩; simp only [mul_assoc, hg₁, inv_mul_cancel_left]
#align measure_theory.measure.haar.mul_left_index_le MeasureTheory.Measure.haar.mul_left_index_le
#align measure_theory.measure.haar.add_left_add_index_le MeasureTheory.Measure.haar.add_left_addIndex_le
@[to_additive is_left_invariant_addIndex]
theorem is_left_invariant_index {K : Set G} (hK : IsCompact K) (g : G) {V : Set G}
(hV : (interior V).Nonempty) : index ((fun h => g * h) '' K) V = index K V := by
refine le_antisymm (mul_left_index_le hK hV g) ?_
convert mul_left_index_le (hK.image <| continuous_mul_left g) hV g⁻¹
rw [image_image]; symm; convert image_id' _ with h; apply inv_mul_cancel_left
#align measure_theory.measure.haar.is_left_invariant_index MeasureTheory.Measure.haar.is_left_invariant_index
#align measure_theory.measure.haar.is_left_invariant_add_index MeasureTheory.Measure.haar.is_left_invariant_addIndex
@[to_additive add_prehaar_le_addIndex]
theorem prehaar_le_index (K₀ : PositiveCompacts G) {U : Set G} (K : Compacts G)
(hU : (interior U).Nonempty) : prehaar (K₀ : Set G) U K ≤ index (K : Set G) K₀ := by
unfold prehaar; rw [div_le_iff] <;> norm_cast
· apply le_index_mul K₀ K hU
· exact index_pos K₀ hU
#align measure_theory.measure.haar.prehaar_le_index MeasureTheory.Measure.haar.prehaar_le_index
#align measure_theory.measure.haar.add_prehaar_le_add_index MeasureTheory.Measure.haar.add_prehaar_le_addIndex
@[to_additive]
theorem prehaar_pos (K₀ : PositiveCompacts G) {U : Set G} (hU : (interior U).Nonempty) {K : Set G}
(h1K : IsCompact K) (h2K : (interior K).Nonempty) : 0 < prehaar (K₀ : Set G) U ⟨K, h1K⟩ := by
apply div_pos <;> norm_cast
· apply index_pos ⟨⟨K, h1K⟩, h2K⟩ hU
· exact index_pos K₀ hU
#align measure_theory.measure.haar.prehaar_pos MeasureTheory.Measure.haar.prehaar_pos
#align measure_theory.measure.haar.add_prehaar_pos MeasureTheory.Measure.haar.addPrehaar_pos
@[to_additive]
theorem prehaar_mono {K₀ : PositiveCompacts G} {U : Set G} (hU : (interior U).Nonempty)
{K₁ K₂ : Compacts G} (h : (K₁ : Set G) ⊆ K₂.1) :
prehaar (K₀ : Set G) U K₁ ≤ prehaar (K₀ : Set G) U K₂ := by
simp only [prehaar]; rw [div_le_div_right]
· exact mod_cast index_mono K₂.2 h hU
· exact mod_cast index_pos K₀ hU
#align measure_theory.measure.haar.prehaar_mono MeasureTheory.Measure.haar.prehaar_mono
#align measure_theory.measure.haar.add_prehaar_mono MeasureTheory.Measure.haar.addPrehaar_mono
@[to_additive]
theorem prehaar_self {K₀ : PositiveCompacts G} {U : Set G} (hU : (interior U).Nonempty) :
prehaar (K₀ : Set G) U K₀.toCompacts = 1 :=
div_self <| ne_of_gt <| mod_cast index_pos K₀ hU
#align measure_theory.measure.haar.prehaar_self MeasureTheory.Measure.haar.prehaar_self
#align measure_theory.measure.haar.add_prehaar_self MeasureTheory.Measure.haar.addPrehaar_self
@[to_additive]
theorem prehaar_sup_le {K₀ : PositiveCompacts G} {U : Set G} (K₁ K₂ : Compacts G)
(hU : (interior U).Nonempty) :
prehaar (K₀ : Set G) U (K₁ ⊔ K₂) ≤ prehaar (K₀ : Set G) U K₁ + prehaar (K₀ : Set G) U K₂ := by
simp only [prehaar]; rw [div_add_div_same, div_le_div_right]
· exact mod_cast index_union_le K₁ K₂ hU
· exact mod_cast index_pos K₀ hU
#align measure_theory.measure.haar.prehaar_sup_le MeasureTheory.Measure.haar.prehaar_sup_le
#align measure_theory.measure.haar.add_prehaar_sup_le MeasureTheory.Measure.haar.addPrehaar_sup_le
@[to_additive]
theorem prehaar_sup_eq {K₀ : PositiveCompacts G} {U : Set G} {K₁ K₂ : Compacts G}
(hU : (interior U).Nonempty) (h : Disjoint (K₁.1 * U⁻¹) (K₂.1 * U⁻¹)) :
prehaar (K₀ : Set G) U (K₁ ⊔ K₂) = prehaar (K₀ : Set G) U K₁ + prehaar (K₀ : Set G) U K₂ := by
simp only [prehaar]; rw [div_add_div_same]
-- Porting note: Here was `congr`, but `to_additive` failed to generate a theorem.
refine congr_arg (fun x : ℝ => x / index K₀ U) ?_
exact mod_cast index_union_eq K₁ K₂ hU h
#align measure_theory.measure.haar.prehaar_sup_eq MeasureTheory.Measure.haar.prehaar_sup_eq
#align measure_theory.measure.haar.add_prehaar_sup_eq MeasureTheory.Measure.haar.addPrehaar_sup_eq
@[to_additive]
theorem is_left_invariant_prehaar {K₀ : PositiveCompacts G} {U : Set G} (hU : (interior U).Nonempty)
(g : G) (K : Compacts G) :
prehaar (K₀ : Set G) U (K.map _ <| continuous_mul_left g) = prehaar (K₀ : Set G) U K := by
simp only [prehaar, Compacts.coe_map, is_left_invariant_index K.isCompact _ hU]
#align measure_theory.measure.haar.is_left_invariant_prehaar MeasureTheory.Measure.haar.is_left_invariant_prehaar
#align measure_theory.measure.haar.is_left_invariant_add_prehaar MeasureTheory.Measure.haar.is_left_invariant_addPrehaar
@[to_additive]
theorem prehaar_mem_haarProduct (K₀ : PositiveCompacts G) {U : Set G} (hU : (interior U).Nonempty) :
prehaar (K₀ : Set G) U ∈ haarProduct (K₀ : Set G) := by
rintro ⟨K, hK⟩ _; rw [mem_Icc]; exact ⟨prehaar_nonneg K₀ _, prehaar_le_index K₀ _ hU⟩
#align measure_theory.measure.haar.prehaar_mem_haar_product MeasureTheory.Measure.haar.prehaar_mem_haarProduct
#align measure_theory.measure.haar.add_prehaar_mem_add_haar_product MeasureTheory.Measure.haar.addPrehaar_mem_addHaarProduct
@[to_additive]
theorem nonempty_iInter_clPrehaar (K₀ : PositiveCompacts G) :
(haarProduct (K₀ : Set G) ∩ ⋂ V : OpenNhdsOf (1 : G), clPrehaar K₀ V).Nonempty := by
have : IsCompact (haarProduct (K₀ : Set G)) := by
apply isCompact_univ_pi; intro K; apply isCompact_Icc
refine this.inter_iInter_nonempty (clPrehaar K₀) (fun s => isClosed_closure) fun t => ?_
let V₀ := ⋂ V ∈ t, (V : OpenNhdsOf (1 : G)).carrier
have h1V₀ : IsOpen V₀ := isOpen_biInter_finset <| by rintro ⟨⟨V, hV₁⟩, hV₂⟩ _; exact hV₁
have h2V₀ : (1 : G) ∈ V₀ := by simp only [V₀, mem_iInter]; rintro ⟨⟨V, hV₁⟩, hV₂⟩ _; exact hV₂
refine ⟨prehaar K₀ V₀, ?_⟩
constructor
· apply prehaar_mem_haarProduct K₀; use 1; rwa [h1V₀.interior_eq]
· simp only [mem_iInter]; rintro ⟨V, hV⟩ h2V; apply subset_closure
apply mem_image_of_mem; rw [mem_setOf_eq]
exact ⟨Subset.trans (iInter_subset _ ⟨V, hV⟩) (iInter_subset _ h2V), h1V₀, h2V₀⟩
#align measure_theory.measure.haar.nonempty_Inter_cl_prehaar MeasureTheory.Measure.haar.nonempty_iInter_clPrehaar
#align measure_theory.measure.haar.nonempty_Inter_cl_add_prehaar MeasureTheory.Measure.haar.nonempty_iInter_clAddPrehaar
-- Porting note: Even in `noncomputable section`, a definition with `to_additive` require
-- `noncomputable` to generate an additive definition.
-- Please refer to leanprover/lean4#2077.
@[to_additive addCHaar "additive version of `MeasureTheory.Measure.haar.chaar`"]
noncomputable def chaar (K₀ : PositiveCompacts G) (K : Compacts G) : ℝ :=
Classical.choose (nonempty_iInter_clPrehaar K₀) K
#align measure_theory.measure.haar.chaar MeasureTheory.Measure.haar.chaar
#align measure_theory.measure.haar.add_chaar MeasureTheory.Measure.haar.addCHaar
@[to_additive addCHaar_mem_addHaarProduct]
theorem chaar_mem_haarProduct (K₀ : PositiveCompacts G) : chaar K₀ ∈ haarProduct (K₀ : Set G) :=
(Classical.choose_spec (nonempty_iInter_clPrehaar K₀)).1
#align measure_theory.measure.haar.chaar_mem_haar_product MeasureTheory.Measure.haar.chaar_mem_haarProduct
#align measure_theory.measure.haar.add_chaar_mem_add_haar_product MeasureTheory.Measure.haar.addCHaar_mem_addHaarProduct
@[to_additive addCHaar_mem_clAddPrehaar]
| Mathlib/MeasureTheory/Measure/Haar/Basic.lean | 422 | 425 | theorem chaar_mem_clPrehaar (K₀ : PositiveCompacts G) (V : OpenNhdsOf (1 : G)) :
chaar K₀ ∈ clPrehaar (K₀ : Set G) V := by |
have := (Classical.choose_spec (nonempty_iInter_clPrehaar K₀)).2; rw [mem_iInter] at this
exact this V
|
import Mathlib.MeasureTheory.PiSystem
import Mathlib.Order.OmegaCompletePartialOrder
import Mathlib.Topology.Constructions
import Mathlib.MeasureTheory.MeasurableSpace.Basic
open Set
namespace MeasureTheory
variable {ι : Type _} {α : ι → Type _}
section cylinder
def cylinder (s : Finset ι) (S : Set (∀ i : s, α i)) : Set (∀ i, α i) :=
(fun (f : ∀ i, α i) (i : s) ↦ f i) ⁻¹' S
@[simp]
theorem mem_cylinder (s : Finset ι) (S : Set (∀ i : s, α i)) (f : ∀ i, α i) :
f ∈ cylinder s S ↔ (fun i : s ↦ f i) ∈ S :=
mem_preimage
@[simp]
theorem cylinder_empty (s : Finset ι) : cylinder s (∅ : Set (∀ i : s, α i)) = ∅ := by
rw [cylinder, preimage_empty]
@[simp]
theorem cylinder_univ (s : Finset ι) : cylinder s (univ : Set (∀ i : s, α i)) = univ := by
rw [cylinder, preimage_univ]
@[simp]
theorem cylinder_eq_empty_iff [h_nonempty : Nonempty (∀ i, α i)] (s : Finset ι)
(S : Set (∀ i : s, α i)) :
cylinder s S = ∅ ↔ S = ∅ := by
refine ⟨fun h ↦ ?_, fun h ↦ by (rw [h]; exact cylinder_empty _)⟩
by_contra hS
rw [← Ne, ← nonempty_iff_ne_empty] at hS
let f := hS.some
have hf : f ∈ S := hS.choose_spec
classical
let f' : ∀ i, α i := fun i ↦ if hi : i ∈ s then f ⟨i, hi⟩ else h_nonempty.some i
have hf' : f' ∈ cylinder s S := by
rw [mem_cylinder]
simpa only [f', Finset.coe_mem, dif_pos]
rw [h] at hf'
exact not_mem_empty _ hf'
| Mathlib/MeasureTheory/Constructions/Cylinders.lean | 185 | 191 | theorem inter_cylinder (s₁ s₂ : Finset ι) (S₁ : Set (∀ i : s₁, α i)) (S₂ : Set (∀ i : s₂, α i))
[DecidableEq ι] :
cylinder s₁ S₁ ∩ cylinder s₂ S₂ =
cylinder (s₁ ∪ s₂)
((fun f ↦ fun j : s₁ ↦ f ⟨j, Finset.mem_union_left s₂ j.prop⟩) ⁻¹' S₁ ∩
(fun f ↦ fun j : s₂ ↦ f ⟨j, Finset.mem_union_right s₁ j.prop⟩) ⁻¹' S₂) := by |
ext1 f; simp only [mem_inter_iff, mem_cylinder, mem_setOf_eq]; rfl
|
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'
| Mathlib/Topology/ContinuousOn.lean | 756 | 758 | 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]
|
import Mathlib.Algebra.Group.Commute.Basic
import Mathlib.Data.Fintype.Card
import Mathlib.GroupTheory.Perm.Basic
#align_import group_theory.perm.support from "leanprover-community/mathlib"@"9003f28797c0664a49e4179487267c494477d853"
open Equiv Finset
namespace Equiv.Perm
variable {α : Type*}
section support
variable [DecidableEq α] [Fintype α] {f g : Perm α}
def support (f : Perm α) : Finset α :=
univ.filter fun x => f x ≠ x
#align equiv.perm.support Equiv.Perm.support
@[simp]
theorem mem_support {x : α} : x ∈ f.support ↔ f x ≠ x := by
rw [support, mem_filter, and_iff_right (mem_univ x)]
#align equiv.perm.mem_support Equiv.Perm.mem_support
theorem not_mem_support {x : α} : x ∉ f.support ↔ f x = x := by simp
#align equiv.perm.not_mem_support Equiv.Perm.not_mem_support
theorem coe_support_eq_set_support (f : Perm α) : (f.support : Set α) = { x | f x ≠ x } := by
ext
simp
#align equiv.perm.coe_support_eq_set_support Equiv.Perm.coe_support_eq_set_support
@[simp]
theorem support_eq_empty_iff {σ : Perm α} : σ.support = ∅ ↔ σ = 1 := by
simp_rw [Finset.ext_iff, mem_support, Finset.not_mem_empty, iff_false_iff, not_not,
Equiv.Perm.ext_iff, one_apply]
#align equiv.perm.support_eq_empty_iff Equiv.Perm.support_eq_empty_iff
@[simp]
theorem support_one : (1 : Perm α).support = ∅ := by rw [support_eq_empty_iff]
#align equiv.perm.support_one Equiv.Perm.support_one
@[simp]
theorem support_refl : support (Equiv.refl α) = ∅ :=
support_one
#align equiv.perm.support_refl Equiv.Perm.support_refl
theorem support_congr (h : f.support ⊆ g.support) (h' : ∀ x ∈ g.support, f x = g x) : f = g := by
ext x
by_cases hx : x ∈ g.support
· exact h' x hx
· rw [not_mem_support.mp hx, ← not_mem_support]
exact fun H => hx (h H)
#align equiv.perm.support_congr Equiv.Perm.support_congr
theorem support_mul_le (f g : Perm α) : (f * g).support ≤ f.support ⊔ g.support := fun x => by
simp only [sup_eq_union]
rw [mem_union, mem_support, mem_support, mem_support, mul_apply, ← not_and_or, not_imp_not]
rintro ⟨hf, hg⟩
rw [hg, hf]
#align equiv.perm.support_mul_le Equiv.Perm.support_mul_le
| Mathlib/GroupTheory/Perm/Support.lean | 339 | 350 | theorem exists_mem_support_of_mem_support_prod {l : List (Perm α)} {x : α}
(hx : x ∈ l.prod.support) : ∃ f : Perm α, f ∈ l ∧ x ∈ f.support := by |
contrapose! hx
simp_rw [mem_support, not_not] at hx ⊢
induction' l with f l ih
· rfl
· rw [List.prod_cons, mul_apply, ih, hx]
· simp only [List.find?, List.mem_cons, true_or]
intros f' hf'
refine hx f' ?_
simp only [List.find?, List.mem_cons]
exact Or.inr hf'
|
import Mathlib.Algebra.Group.NatPowAssoc
import Mathlib.Algebra.Polynomial.AlgebraMap
import Mathlib.Algebra.Polynomial.Induction
import Mathlib.Algebra.Polynomial.Eval
namespace Polynomial
section MulActionWithZero
variable {R : Type*} [Semiring R] (r : R) (p : R[X]) {S : Type*} [AddCommMonoid S] [Pow S ℕ]
[MulActionWithZero R S] (x : S)
def smul_pow : ℕ → R → S := fun n r => r • x^n
irreducible_def smeval : S := p.sum (smul_pow x)
theorem smeval_eq_sum : p.smeval x = p.sum (smul_pow x) := by rw [smeval_def]
@[simp]
theorem smeval_C : (C r).smeval x = r • x ^ 0 := by
simp only [smeval_eq_sum, smul_pow, zero_smul, sum_C_index]
@[simp]
theorem smeval_monomial (n : ℕ) :
(monomial n r).smeval x = r • x ^ n := by
simp only [smeval_eq_sum, smul_pow, zero_smul, sum_monomial_index]
theorem eval_eq_smeval : p.eval r = p.smeval r := by
rw [eval_eq_sum, smeval_eq_sum]
rfl
theorem eval₂_eq_smeval (R : Type*) [Semiring R] {S : Type*} [Semiring S] (f : R →+* S) (p : R[X])
(x: S) : letI : Module R S := RingHom.toModule f
p.eval₂ f x = p.smeval x := by
letI : Module R S := RingHom.toModule f
rw [smeval_eq_sum, eval₂_eq_sum]
rfl
variable (R)
@[simp]
theorem smeval_zero : (0 : R[X]).smeval x = 0 := by
simp only [smeval_eq_sum, smul_pow, sum_zero_index]
@[simp]
theorem smeval_one : (1 : R[X]).smeval x = 1 • x ^ 0 := by
rw [← C_1, smeval_C]
simp only [Nat.cast_one, one_smul]
@[simp]
theorem smeval_X :
(X : R[X]).smeval x = x ^ 1 := by
simp only [smeval_eq_sum, smul_pow, zero_smul, sum_X_index, one_smul]
@[simp]
| Mathlib/Algebra/Polynomial/Smeval.lean | 93 | 95 | theorem smeval_X_pow {n : ℕ} :
(X ^ n : R[X]).smeval x = x ^ n := by |
simp only [smeval_eq_sum, smul_pow, X_pow_eq_monomial, zero_smul, sum_monomial_index, one_smul]
|
import Mathlib.Dynamics.Ergodic.MeasurePreserving
import Mathlib.MeasureTheory.Function.SimpleFunc
import Mathlib.MeasureTheory.Measure.MutuallySingular
import Mathlib.MeasureTheory.Measure.Count
import Mathlib.Topology.IndicatorConstPointwise
import Mathlib.MeasureTheory.Constructions.BorelSpace.Real
#align_import measure_theory.integral.lebesgue from "leanprover-community/mathlib"@"c14c8fcde993801fca8946b0d80131a1a81d1520"
assert_not_exists NormedSpace
set_option autoImplicit true
noncomputable section
open Set hiding restrict restrict_apply
open Filter ENNReal
open Function (support)
open scoped Classical
open Topology NNReal ENNReal MeasureTheory
namespace MeasureTheory
local infixr:25 " →ₛ " => SimpleFunc
variable {α β γ δ : Type*}
section Lintegral
open SimpleFunc
variable {m : MeasurableSpace α} {μ ν : Measure α}
irreducible_def lintegral {_ : MeasurableSpace α} (μ : Measure α) (f : α → ℝ≥0∞) : ℝ≥0∞ :=
⨆ (g : α →ₛ ℝ≥0∞) (_ : ⇑g ≤ f), g.lintegral μ
#align measure_theory.lintegral MeasureTheory.lintegral
@[inherit_doc MeasureTheory.lintegral]
notation3 "∫⁻ "(...)", "r:60:(scoped f => f)" ∂"μ:70 => lintegral μ r
@[inherit_doc MeasureTheory.lintegral]
notation3 "∫⁻ "(...)", "r:60:(scoped f => lintegral volume f) => r
@[inherit_doc MeasureTheory.lintegral]
notation3"∫⁻ "(...)" in "s", "r:60:(scoped f => f)" ∂"μ:70 => lintegral (Measure.restrict μ s) r
@[inherit_doc MeasureTheory.lintegral]
notation3"∫⁻ "(...)" in "s", "r:60:(scoped f => lintegral (Measure.restrict volume s) f) => r
theorem SimpleFunc.lintegral_eq_lintegral {m : MeasurableSpace α} (f : α →ₛ ℝ≥0∞) (μ : Measure α) :
∫⁻ a, f a ∂μ = f.lintegral μ := by
rw [MeasureTheory.lintegral]
exact le_antisymm (iSup₂_le fun g hg => lintegral_mono hg <| le_rfl)
(le_iSup₂_of_le f le_rfl le_rfl)
#align measure_theory.simple_func.lintegral_eq_lintegral MeasureTheory.SimpleFunc.lintegral_eq_lintegral
@[mono]
theorem lintegral_mono' {m : MeasurableSpace α} ⦃μ ν : Measure α⦄ (hμν : μ ≤ ν) ⦃f g : α → ℝ≥0∞⦄
(hfg : f ≤ g) : ∫⁻ a, f a ∂μ ≤ ∫⁻ a, g a ∂ν := by
rw [lintegral, lintegral]
exact iSup_mono fun φ => iSup_mono' fun hφ => ⟨le_trans hφ hfg, lintegral_mono (le_refl φ) hμν⟩
#align measure_theory.lintegral_mono' MeasureTheory.lintegral_mono'
-- workaround for the known eta-reduction issue with `@[gcongr]`
@[gcongr] theorem lintegral_mono_fn' ⦃f g : α → ℝ≥0∞⦄ (hfg : ∀ x, f x ≤ g x) (h2 : μ ≤ ν) :
lintegral μ f ≤ lintegral ν g :=
lintegral_mono' h2 hfg
theorem lintegral_mono ⦃f g : α → ℝ≥0∞⦄ (hfg : f ≤ g) : ∫⁻ a, f a ∂μ ≤ ∫⁻ a, g a ∂μ :=
lintegral_mono' (le_refl μ) hfg
#align measure_theory.lintegral_mono MeasureTheory.lintegral_mono
-- workaround for the known eta-reduction issue with `@[gcongr]`
@[gcongr] theorem lintegral_mono_fn ⦃f g : α → ℝ≥0∞⦄ (hfg : ∀ x, f x ≤ g x) :
lintegral μ f ≤ lintegral μ g :=
lintegral_mono hfg
theorem lintegral_mono_nnreal {f g : α → ℝ≥0} (h : f ≤ g) : ∫⁻ a, f a ∂μ ≤ ∫⁻ a, g a ∂μ :=
lintegral_mono fun a => ENNReal.coe_le_coe.2 (h a)
#align measure_theory.lintegral_mono_nnreal MeasureTheory.lintegral_mono_nnreal
theorem iSup_lintegral_measurable_le_eq_lintegral (f : α → ℝ≥0∞) :
⨆ (g : α → ℝ≥0∞) (_ : Measurable g) (_ : g ≤ f), ∫⁻ a, g a ∂μ = ∫⁻ a, f a ∂μ := by
apply le_antisymm
· exact iSup_le fun i => iSup_le fun _ => iSup_le fun h'i => lintegral_mono h'i
· rw [lintegral]
refine iSup₂_le fun i hi => le_iSup₂_of_le i i.measurable <| le_iSup_of_le hi ?_
exact le_of_eq (i.lintegral_eq_lintegral _).symm
#align measure_theory.supr_lintegral_measurable_le_eq_lintegral MeasureTheory.iSup_lintegral_measurable_le_eq_lintegral
theorem lintegral_mono_set {_ : MeasurableSpace α} ⦃μ : Measure α⦄ {s t : Set α} {f : α → ℝ≥0∞}
(hst : s ⊆ t) : ∫⁻ x in s, f x ∂μ ≤ ∫⁻ x in t, f x ∂μ :=
lintegral_mono' (Measure.restrict_mono hst (le_refl μ)) (le_refl f)
#align measure_theory.lintegral_mono_set MeasureTheory.lintegral_mono_set
theorem lintegral_mono_set' {_ : MeasurableSpace α} ⦃μ : Measure α⦄ {s t : Set α} {f : α → ℝ≥0∞}
(hst : s ≤ᵐ[μ] t) : ∫⁻ x in s, f x ∂μ ≤ ∫⁻ x in t, f x ∂μ :=
lintegral_mono' (Measure.restrict_mono' hst (le_refl μ)) (le_refl f)
#align measure_theory.lintegral_mono_set' MeasureTheory.lintegral_mono_set'
theorem monotone_lintegral {_ : MeasurableSpace α} (μ : Measure α) : Monotone (lintegral μ) :=
lintegral_mono
#align measure_theory.monotone_lintegral MeasureTheory.monotone_lintegral
@[simp]
theorem lintegral_const (c : ℝ≥0∞) : ∫⁻ _, c ∂μ = c * μ univ := by
rw [← SimpleFunc.const_lintegral, ← SimpleFunc.lintegral_eq_lintegral, SimpleFunc.coe_const]
rfl
#align measure_theory.lintegral_const MeasureTheory.lintegral_const
theorem lintegral_zero : ∫⁻ _ : α, 0 ∂μ = 0 := by simp
#align measure_theory.lintegral_zero MeasureTheory.lintegral_zero
theorem lintegral_zero_fun : lintegral μ (0 : α → ℝ≥0∞) = 0 :=
lintegral_zero
#align measure_theory.lintegral_zero_fun MeasureTheory.lintegral_zero_fun
-- @[simp] -- Porting note (#10618): simp can prove this
theorem lintegral_one : ∫⁻ _, (1 : ℝ≥0∞) ∂μ = μ univ := by rw [lintegral_const, one_mul]
#align measure_theory.lintegral_one MeasureTheory.lintegral_one
theorem set_lintegral_const (s : Set α) (c : ℝ≥0∞) : ∫⁻ _ in s, c ∂μ = c * μ s := by
rw [lintegral_const, Measure.restrict_apply_univ]
#align measure_theory.set_lintegral_const MeasureTheory.set_lintegral_const
theorem set_lintegral_one (s) : ∫⁻ _ in s, 1 ∂μ = μ s := by rw [set_lintegral_const, one_mul]
#align measure_theory.set_lintegral_one MeasureTheory.set_lintegral_one
theorem set_lintegral_const_lt_top [IsFiniteMeasure μ] (s : Set α) {c : ℝ≥0∞} (hc : c ≠ ∞) :
∫⁻ _ in s, c ∂μ < ∞ := by
rw [lintegral_const]
exact ENNReal.mul_lt_top hc (measure_ne_top (μ.restrict s) univ)
#align measure_theory.set_lintegral_const_lt_top MeasureTheory.set_lintegral_const_lt_top
theorem lintegral_const_lt_top [IsFiniteMeasure μ] {c : ℝ≥0∞} (hc : c ≠ ∞) : ∫⁻ _, c ∂μ < ∞ := by
simpa only [Measure.restrict_univ] using set_lintegral_const_lt_top (univ : Set α) hc
#align measure_theory.lintegral_const_lt_top MeasureTheory.lintegral_const_lt_top
section
variable (μ)
theorem exists_measurable_le_lintegral_eq (f : α → ℝ≥0∞) :
∃ g : α → ℝ≥0∞, Measurable g ∧ g ≤ f ∧ ∫⁻ a, f a ∂μ = ∫⁻ a, g a ∂μ := by
rcases eq_or_ne (∫⁻ a, f a ∂μ) 0 with h₀ | h₀
· exact ⟨0, measurable_zero, zero_le f, h₀.trans lintegral_zero.symm⟩
rcases exists_seq_strictMono_tendsto' h₀.bot_lt with ⟨L, _, hLf, hL_tendsto⟩
have : ∀ n, ∃ g : α → ℝ≥0∞, Measurable g ∧ g ≤ f ∧ L n < ∫⁻ a, g a ∂μ := by
intro n
simpa only [← iSup_lintegral_measurable_le_eq_lintegral f, lt_iSup_iff, exists_prop] using
(hLf n).2
choose g hgm hgf hLg using this
refine
⟨fun x => ⨆ n, g n x, measurable_iSup hgm, fun x => iSup_le fun n => hgf n x, le_antisymm ?_ ?_⟩
· refine le_of_tendsto' hL_tendsto fun n => (hLg n).le.trans <| lintegral_mono fun x => ?_
exact le_iSup (fun n => g n x) n
· exact lintegral_mono fun x => iSup_le fun n => hgf n x
#align measure_theory.exists_measurable_le_lintegral_eq MeasureTheory.exists_measurable_le_lintegral_eq
end
theorem lintegral_eq_nnreal {m : MeasurableSpace α} (f : α → ℝ≥0∞) (μ : Measure α) :
∫⁻ a, f a ∂μ =
⨆ (φ : α →ₛ ℝ≥0) (_ : ∀ x, ↑(φ x) ≤ f x), (φ.map ((↑) : ℝ≥0 → ℝ≥0∞)).lintegral μ := by
rw [lintegral]
refine
le_antisymm (iSup₂_le fun φ hφ => ?_) (iSup_mono' fun φ => ⟨φ.map ((↑) : ℝ≥0 → ℝ≥0∞), le_rfl⟩)
by_cases h : ∀ᵐ a ∂μ, φ a ≠ ∞
· let ψ := φ.map ENNReal.toNNReal
replace h : ψ.map ((↑) : ℝ≥0 → ℝ≥0∞) =ᵐ[μ] φ := h.mono fun a => ENNReal.coe_toNNReal
have : ∀ x, ↑(ψ x) ≤ f x := fun x => le_trans ENNReal.coe_toNNReal_le_self (hφ x)
exact
le_iSup_of_le (φ.map ENNReal.toNNReal) (le_iSup_of_le this (ge_of_eq <| lintegral_congr h))
· have h_meas : μ (φ ⁻¹' {∞}) ≠ 0 := mt measure_zero_iff_ae_nmem.1 h
refine le_trans le_top (ge_of_eq <| (iSup_eq_top _).2 fun b hb => ?_)
obtain ⟨n, hn⟩ : ∃ n : ℕ, b < n * μ (φ ⁻¹' {∞}) := exists_nat_mul_gt h_meas (ne_of_lt hb)
use (const α (n : ℝ≥0)).restrict (φ ⁻¹' {∞})
simp only [lt_iSup_iff, exists_prop, coe_restrict, φ.measurableSet_preimage, coe_const,
ENNReal.coe_indicator, map_coe_ennreal_restrict, SimpleFunc.map_const, ENNReal.coe_natCast,
restrict_const_lintegral]
refine ⟨indicator_le fun x hx => le_trans ?_ (hφ _), hn⟩
simp only [mem_preimage, mem_singleton_iff] at hx
simp only [hx, le_top]
#align measure_theory.lintegral_eq_nnreal MeasureTheory.lintegral_eq_nnreal
theorem exists_simpleFunc_forall_lintegral_sub_lt_of_pos {f : α → ℝ≥0∞} (h : ∫⁻ x, f x ∂μ ≠ ∞)
{ε : ℝ≥0∞} (hε : ε ≠ 0) :
∃ φ : α →ₛ ℝ≥0,
(∀ x, ↑(φ x) ≤ f x) ∧
∀ ψ : α →ₛ ℝ≥0, (∀ x, ↑(ψ x) ≤ f x) → (map (↑) (ψ - φ)).lintegral μ < ε := by
rw [lintegral_eq_nnreal] at h
have := ENNReal.lt_add_right h hε
erw [ENNReal.biSup_add] at this <;> [skip; exact ⟨0, fun x => zero_le _⟩]
simp_rw [lt_iSup_iff, iSup_lt_iff, iSup_le_iff] at this
rcases this with ⟨φ, hle : ∀ x, ↑(φ x) ≤ f x, b, hbφ, hb⟩
refine ⟨φ, hle, fun ψ hψ => ?_⟩
have : (map (↑) φ).lintegral μ ≠ ∞ := ne_top_of_le_ne_top h (by exact le_iSup₂ (α := ℝ≥0∞) φ hle)
rw [← ENNReal.add_lt_add_iff_left this, ← add_lintegral, ← SimpleFunc.map_add @ENNReal.coe_add]
refine (hb _ fun x => le_trans ?_ (max_le (hle x) (hψ x))).trans_lt hbφ
norm_cast
simp only [add_apply, sub_apply, add_tsub_eq_max]
rfl
#align measure_theory.exists_simple_func_forall_lintegral_sub_lt_of_pos MeasureTheory.exists_simpleFunc_forall_lintegral_sub_lt_of_pos
theorem iSup_lintegral_le {ι : Sort*} (f : ι → α → ℝ≥0∞) :
⨆ i, ∫⁻ a, f i a ∂μ ≤ ∫⁻ a, ⨆ i, f i a ∂μ := by
simp only [← iSup_apply]
exact (monotone_lintegral μ).le_map_iSup
#align measure_theory.supr_lintegral_le MeasureTheory.iSup_lintegral_le
theorem iSup₂_lintegral_le {ι : Sort*} {ι' : ι → Sort*} (f : ∀ i, ι' i → α → ℝ≥0∞) :
⨆ (i) (j), ∫⁻ a, f i j a ∂μ ≤ ∫⁻ a, ⨆ (i) (j), f i j a ∂μ := by
convert (monotone_lintegral μ).le_map_iSup₂ f with a
simp only [iSup_apply]
#align measure_theory.supr₂_lintegral_le MeasureTheory.iSup₂_lintegral_le
theorem le_iInf_lintegral {ι : Sort*} (f : ι → α → ℝ≥0∞) :
∫⁻ a, ⨅ i, f i a ∂μ ≤ ⨅ i, ∫⁻ a, f i a ∂μ := by
simp only [← iInf_apply]
exact (monotone_lintegral μ).map_iInf_le
#align measure_theory.le_infi_lintegral MeasureTheory.le_iInf_lintegral
theorem le_iInf₂_lintegral {ι : Sort*} {ι' : ι → Sort*} (f : ∀ i, ι' i → α → ℝ≥0∞) :
∫⁻ a, ⨅ (i) (h : ι' i), f i h a ∂μ ≤ ⨅ (i) (h : ι' i), ∫⁻ a, f i h a ∂μ := by
convert (monotone_lintegral μ).map_iInf₂_le f with a
simp only [iInf_apply]
#align measure_theory.le_infi₂_lintegral MeasureTheory.le_iInf₂_lintegral
theorem lintegral_mono_ae {f g : α → ℝ≥0∞} (h : ∀ᵐ a ∂μ, f a ≤ g a) :
∫⁻ a, f a ∂μ ≤ ∫⁻ a, g a ∂μ := by
rcases exists_measurable_superset_of_null h with ⟨t, hts, ht, ht0⟩
have : ∀ᵐ x ∂μ, x ∉ t := measure_zero_iff_ae_nmem.1 ht0
rw [lintegral, lintegral]
refine iSup_le fun s => iSup_le fun hfs => le_iSup_of_le (s.restrict tᶜ) <| le_iSup_of_le ?_ ?_
· intro a
by_cases h : a ∈ t <;>
simp only [restrict_apply s ht.compl, mem_compl_iff, h, not_true, not_false_eq_true,
indicator_of_not_mem, zero_le, not_false_eq_true, indicator_of_mem]
exact le_trans (hfs a) (_root_.by_contradiction fun hnfg => h (hts hnfg))
· refine le_of_eq (SimpleFunc.lintegral_congr <| this.mono fun a hnt => ?_)
by_cases hat : a ∈ t <;> simp only [restrict_apply s ht.compl, mem_compl_iff, hat, not_true,
not_false_eq_true, indicator_of_not_mem, not_false_eq_true, indicator_of_mem]
exact (hnt hat).elim
#align measure_theory.lintegral_mono_ae MeasureTheory.lintegral_mono_ae
theorem set_lintegral_mono_ae {s : Set α} {f g : α → ℝ≥0∞} (hf : Measurable f) (hg : Measurable g)
(hfg : ∀ᵐ x ∂μ, x ∈ s → f x ≤ g x) : ∫⁻ x in s, f x ∂μ ≤ ∫⁻ x in s, g x ∂μ :=
lintegral_mono_ae <| (ae_restrict_iff <| measurableSet_le hf hg).2 hfg
#align measure_theory.set_lintegral_mono_ae MeasureTheory.set_lintegral_mono_ae
theorem set_lintegral_mono {s : Set α} {f g : α → ℝ≥0∞} (hf : Measurable f) (hg : Measurable g)
(hfg : ∀ x ∈ s, f x ≤ g x) : ∫⁻ x in s, f x ∂μ ≤ ∫⁻ x in s, g x ∂μ :=
set_lintegral_mono_ae hf hg (ae_of_all _ hfg)
#align measure_theory.set_lintegral_mono MeasureTheory.set_lintegral_mono
theorem set_lintegral_mono_ae' {s : Set α} {f g : α → ℝ≥0∞} (hs : MeasurableSet s)
(hfg : ∀ᵐ x ∂μ, x ∈ s → f x ≤ g x) : ∫⁻ x in s, f x ∂μ ≤ ∫⁻ x in s, g x ∂μ :=
lintegral_mono_ae <| (ae_restrict_iff' hs).2 hfg
theorem set_lintegral_mono' {s : Set α} {f g : α → ℝ≥0∞} (hs : MeasurableSet s)
(hfg : ∀ x ∈ s, f x ≤ g x) : ∫⁻ x in s, f x ∂μ ≤ ∫⁻ x in s, g x ∂μ :=
set_lintegral_mono_ae' hs (ae_of_all _ hfg)
theorem set_lintegral_le_lintegral (s : Set α) (f : α → ℝ≥0∞) :
∫⁻ x in s, f x ∂μ ≤ ∫⁻ x, f x ∂μ :=
lintegral_mono' Measure.restrict_le_self le_rfl
theorem lintegral_congr_ae {f g : α → ℝ≥0∞} (h : f =ᵐ[μ] g) : ∫⁻ a, f a ∂μ = ∫⁻ a, g a ∂μ :=
le_antisymm (lintegral_mono_ae <| h.le) (lintegral_mono_ae <| h.symm.le)
#align measure_theory.lintegral_congr_ae MeasureTheory.lintegral_congr_ae
theorem lintegral_congr {f g : α → ℝ≥0∞} (h : ∀ a, f a = g a) : ∫⁻ a, f a ∂μ = ∫⁻ a, g a ∂μ := by
simp only [h]
#align measure_theory.lintegral_congr MeasureTheory.lintegral_congr
theorem set_lintegral_congr {f : α → ℝ≥0∞} {s t : Set α} (h : s =ᵐ[μ] t) :
∫⁻ x in s, f x ∂μ = ∫⁻ x in t, f x ∂μ := by rw [Measure.restrict_congr_set h]
#align measure_theory.set_lintegral_congr MeasureTheory.set_lintegral_congr
theorem set_lintegral_congr_fun {f g : α → ℝ≥0∞} {s : Set α} (hs : MeasurableSet s)
(hfg : ∀ᵐ x ∂μ, x ∈ s → f x = g x) : ∫⁻ x in s, f x ∂μ = ∫⁻ x in s, g x ∂μ := by
rw [lintegral_congr_ae]
rw [EventuallyEq]
rwa [ae_restrict_iff' hs]
#align measure_theory.set_lintegral_congr_fun MeasureTheory.set_lintegral_congr_fun
theorem lintegral_ofReal_le_lintegral_nnnorm (f : α → ℝ) :
∫⁻ x, ENNReal.ofReal (f x) ∂μ ≤ ∫⁻ x, ‖f x‖₊ ∂μ := by
simp_rw [← ofReal_norm_eq_coe_nnnorm]
refine lintegral_mono fun x => ENNReal.ofReal_le_ofReal ?_
rw [Real.norm_eq_abs]
exact le_abs_self (f x)
#align measure_theory.lintegral_of_real_le_lintegral_nnnorm MeasureTheory.lintegral_ofReal_le_lintegral_nnnorm
theorem lintegral_nnnorm_eq_of_ae_nonneg {f : α → ℝ} (h_nonneg : 0 ≤ᵐ[μ] f) :
∫⁻ x, ‖f x‖₊ ∂μ = ∫⁻ x, ENNReal.ofReal (f x) ∂μ := by
apply lintegral_congr_ae
filter_upwards [h_nonneg] with x hx
rw [Real.nnnorm_of_nonneg hx, ENNReal.ofReal_eq_coe_nnreal hx]
#align measure_theory.lintegral_nnnorm_eq_of_ae_nonneg MeasureTheory.lintegral_nnnorm_eq_of_ae_nonneg
theorem lintegral_nnnorm_eq_of_nonneg {f : α → ℝ} (h_nonneg : 0 ≤ f) :
∫⁻ x, ‖f x‖₊ ∂μ = ∫⁻ x, ENNReal.ofReal (f x) ∂μ :=
lintegral_nnnorm_eq_of_ae_nonneg (Filter.eventually_of_forall h_nonneg)
#align measure_theory.lintegral_nnnorm_eq_of_nonneg MeasureTheory.lintegral_nnnorm_eq_of_nonneg
theorem lintegral_iSup {f : ℕ → α → ℝ≥0∞} (hf : ∀ n, Measurable (f n)) (h_mono : Monotone f) :
∫⁻ a, ⨆ n, f n a ∂μ = ⨆ n, ∫⁻ a, f n a ∂μ := by
set c : ℝ≥0 → ℝ≥0∞ := (↑)
set F := fun a : α => ⨆ n, f n a
refine le_antisymm ?_ (iSup_lintegral_le _)
rw [lintegral_eq_nnreal]
refine iSup_le fun s => iSup_le fun hsf => ?_
refine ENNReal.le_of_forall_lt_one_mul_le fun a ha => ?_
rcases ENNReal.lt_iff_exists_coe.1 ha with ⟨r, rfl, _⟩
have ha : r < 1 := ENNReal.coe_lt_coe.1 ha
let rs := s.map fun a => r * a
have eq_rs : rs.map c = (const α r : α →ₛ ℝ≥0∞) * map c s := rfl
have eq : ∀ p, rs.map c ⁻¹' {p} = ⋃ n, rs.map c ⁻¹' {p} ∩ { a | p ≤ f n a } := by
intro p
rw [← inter_iUnion]; nth_rw 1 [← inter_univ (map c rs ⁻¹' {p})]
refine Set.ext fun x => and_congr_right fun hx => true_iff_iff.2 ?_
by_cases p_eq : p = 0
· simp [p_eq]
simp only [coe_map, mem_preimage, Function.comp_apply, mem_singleton_iff] at hx
subst hx
have : r * s x ≠ 0 := by rwa [Ne, ← ENNReal.coe_eq_zero]
have : s x ≠ 0 := right_ne_zero_of_mul this
have : (rs.map c) x < ⨆ n : ℕ, f n x := by
refine lt_of_lt_of_le (ENNReal.coe_lt_coe.2 ?_) (hsf x)
suffices r * s x < 1 * s x by simpa
exact mul_lt_mul_of_pos_right ha (pos_iff_ne_zero.2 this)
rcases lt_iSup_iff.1 this with ⟨i, hi⟩
exact mem_iUnion.2 ⟨i, le_of_lt hi⟩
have mono : ∀ r : ℝ≥0∞, Monotone fun n => rs.map c ⁻¹' {r} ∩ { a | r ≤ f n a } := by
intro r i j h
refine inter_subset_inter_right _ ?_
simp_rw [subset_def, mem_setOf]
intro x hx
exact le_trans hx (h_mono h x)
have h_meas : ∀ n, MeasurableSet {a : α | map c rs a ≤ f n a} := fun n =>
measurableSet_le (SimpleFunc.measurable _) (hf n)
calc
(r : ℝ≥0∞) * (s.map c).lintegral μ = ∑ r ∈ (rs.map c).range, r * μ (rs.map c ⁻¹' {r}) := by
rw [← const_mul_lintegral, eq_rs, SimpleFunc.lintegral]
_ = ∑ r ∈ (rs.map c).range, r * μ (⋃ n, rs.map c ⁻¹' {r} ∩ { a | r ≤ f n a }) := by
simp only [(eq _).symm]
_ = ∑ r ∈ (rs.map c).range, ⨆ n, r * μ (rs.map c ⁻¹' {r} ∩ { a | r ≤ f n a }) :=
(Finset.sum_congr rfl fun x _ => by
rw [measure_iUnion_eq_iSup (mono x).directed_le, ENNReal.mul_iSup])
_ = ⨆ n, ∑ r ∈ (rs.map c).range, r * μ (rs.map c ⁻¹' {r} ∩ { a | r ≤ f n a }) := by
refine ENNReal.finset_sum_iSup_nat fun p i j h ↦ ?_
gcongr _ * μ ?_
exact mono p h
_ ≤ ⨆ n : ℕ, ((rs.map c).restrict { a | (rs.map c) a ≤ f n a }).lintegral μ := by
gcongr with n
rw [restrict_lintegral _ (h_meas n)]
refine le_of_eq (Finset.sum_congr rfl fun r _ => ?_)
congr 2 with a
refine and_congr_right ?_
simp (config := { contextual := true })
_ ≤ ⨆ n, ∫⁻ a, f n a ∂μ := by
simp only [← SimpleFunc.lintegral_eq_lintegral]
gcongr with n a
simp only [map_apply] at h_meas
simp only [coe_map, restrict_apply _ (h_meas _), (· ∘ ·)]
exact indicator_apply_le id
#align measure_theory.lintegral_supr MeasureTheory.lintegral_iSup
theorem lintegral_iSup' {f : ℕ → α → ℝ≥0∞} (hf : ∀ n, AEMeasurable (f n) μ)
(h_mono : ∀ᵐ x ∂μ, Monotone fun n => f n x) : ∫⁻ a, ⨆ n, f n a ∂μ = ⨆ n, ∫⁻ a, f n a ∂μ := by
simp_rw [← iSup_apply]
let p : α → (ℕ → ℝ≥0∞) → Prop := fun _ f' => Monotone f'
have hp : ∀ᵐ x ∂μ, p x fun i => f i x := h_mono
have h_ae_seq_mono : Monotone (aeSeq hf p) := by
intro n m hnm x
by_cases hx : x ∈ aeSeqSet hf p
· exact aeSeq.prop_of_mem_aeSeqSet hf hx hnm
· simp only [aeSeq, hx, if_false, le_rfl]
rw [lintegral_congr_ae (aeSeq.iSup hf hp).symm]
simp_rw [iSup_apply]
rw [lintegral_iSup (aeSeq.measurable hf p) h_ae_seq_mono]
congr with n
exact lintegral_congr_ae (aeSeq.aeSeq_n_eq_fun_n_ae hf hp n)
#align measure_theory.lintegral_supr' MeasureTheory.lintegral_iSup'
theorem lintegral_tendsto_of_tendsto_of_monotone {f : ℕ → α → ℝ≥0∞} {F : α → ℝ≥0∞}
(hf : ∀ n, AEMeasurable (f n) μ) (h_mono : ∀ᵐ x ∂μ, Monotone fun n => f n x)
(h_tendsto : ∀ᵐ x ∂μ, Tendsto (fun n => f n x) atTop (𝓝 <| F x)) :
Tendsto (fun n => ∫⁻ x, f n x ∂μ) atTop (𝓝 <| ∫⁻ x, F x ∂μ) := by
have : Monotone fun n => ∫⁻ x, f n x ∂μ := fun i j hij =>
lintegral_mono_ae (h_mono.mono fun x hx => hx hij)
suffices key : ∫⁻ x, F x ∂μ = ⨆ n, ∫⁻ x, f n x ∂μ by
rw [key]
exact tendsto_atTop_iSup this
rw [← lintegral_iSup' hf h_mono]
refine lintegral_congr_ae ?_
filter_upwards [h_mono, h_tendsto] with _ hx_mono hx_tendsto using
tendsto_nhds_unique hx_tendsto (tendsto_atTop_iSup hx_mono)
#align measure_theory.lintegral_tendsto_of_tendsto_of_monotone MeasureTheory.lintegral_tendsto_of_tendsto_of_monotone
theorem lintegral_eq_iSup_eapprox_lintegral {f : α → ℝ≥0∞} (hf : Measurable f) :
∫⁻ a, f a ∂μ = ⨆ n, (eapprox f n).lintegral μ :=
calc
∫⁻ a, f a ∂μ = ∫⁻ a, ⨆ n, (eapprox f n : α → ℝ≥0∞) a ∂μ := by
congr; ext a; rw [iSup_eapprox_apply f hf]
_ = ⨆ n, ∫⁻ a, (eapprox f n : α → ℝ≥0∞) a ∂μ := by
apply lintegral_iSup
· measurability
· intro i j h
exact monotone_eapprox f h
_ = ⨆ n, (eapprox f n).lintegral μ := by
congr; ext n; rw [(eapprox f n).lintegral_eq_lintegral]
#align measure_theory.lintegral_eq_supr_eapprox_lintegral MeasureTheory.lintegral_eq_iSup_eapprox_lintegral
theorem exists_pos_set_lintegral_lt_of_measure_lt {f : α → ℝ≥0∞} (h : ∫⁻ x, f x ∂μ ≠ ∞) {ε : ℝ≥0∞}
(hε : ε ≠ 0) : ∃ δ > 0, ∀ s, μ s < δ → ∫⁻ x in s, f x ∂μ < ε := by
rcases exists_between (pos_iff_ne_zero.mpr hε) with ⟨ε₂, hε₂0, hε₂ε⟩
rcases exists_between hε₂0 with ⟨ε₁, hε₁0, hε₁₂⟩
rcases exists_simpleFunc_forall_lintegral_sub_lt_of_pos h hε₁0.ne' with ⟨φ, _, hφ⟩
rcases φ.exists_forall_le with ⟨C, hC⟩
use (ε₂ - ε₁) / C, ENNReal.div_pos_iff.2 ⟨(tsub_pos_iff_lt.2 hε₁₂).ne', ENNReal.coe_ne_top⟩
refine fun s hs => lt_of_le_of_lt ?_ hε₂ε
simp only [lintegral_eq_nnreal, iSup_le_iff]
intro ψ hψ
calc
(map (↑) ψ).lintegral (μ.restrict s) ≤
(map (↑) φ).lintegral (μ.restrict s) + (map (↑) (ψ - φ)).lintegral (μ.restrict s) := by
rw [← SimpleFunc.add_lintegral, ← SimpleFunc.map_add @ENNReal.coe_add]
refine SimpleFunc.lintegral_mono (fun x => ?_) le_rfl
simp only [add_tsub_eq_max, le_max_right, coe_map, Function.comp_apply, SimpleFunc.coe_add,
SimpleFunc.coe_sub, Pi.add_apply, Pi.sub_apply, ENNReal.coe_max (φ x) (ψ x)]
_ ≤ (map (↑) φ).lintegral (μ.restrict s) + ε₁ := by
gcongr
refine le_trans ?_ (hφ _ hψ).le
exact SimpleFunc.lintegral_mono le_rfl Measure.restrict_le_self
_ ≤ (SimpleFunc.const α (C : ℝ≥0∞)).lintegral (μ.restrict s) + ε₁ := by
gcongr
exact SimpleFunc.lintegral_mono (fun x ↦ ENNReal.coe_le_coe.2 (hC x)) le_rfl
_ = C * μ s + ε₁ := by
simp only [← SimpleFunc.lintegral_eq_lintegral, coe_const, lintegral_const,
Measure.restrict_apply, MeasurableSet.univ, univ_inter, Function.const]
_ ≤ C * ((ε₂ - ε₁) / C) + ε₁ := by gcongr
_ ≤ ε₂ - ε₁ + ε₁ := by gcongr; apply mul_div_le
_ = ε₂ := tsub_add_cancel_of_le hε₁₂.le
#align measure_theory.exists_pos_set_lintegral_lt_of_measure_lt MeasureTheory.exists_pos_set_lintegral_lt_of_measure_lt
theorem tendsto_set_lintegral_zero {ι} {f : α → ℝ≥0∞} (h : ∫⁻ x, f x ∂μ ≠ ∞) {l : Filter ι}
{s : ι → Set α} (hl : Tendsto (μ ∘ s) l (𝓝 0)) :
Tendsto (fun i => ∫⁻ x in s i, f x ∂μ) l (𝓝 0) := by
simp only [ENNReal.nhds_zero, tendsto_iInf, tendsto_principal, mem_Iio,
← pos_iff_ne_zero] at hl ⊢
intro ε ε0
rcases exists_pos_set_lintegral_lt_of_measure_lt h ε0.ne' with ⟨δ, δ0, hδ⟩
exact (hl δ δ0).mono fun i => hδ _
#align measure_theory.tendsto_set_lintegral_zero MeasureTheory.tendsto_set_lintegral_zero
theorem le_lintegral_add (f g : α → ℝ≥0∞) :
∫⁻ a, f a ∂μ + ∫⁻ a, g a ∂μ ≤ ∫⁻ a, f a + g a ∂μ := by
simp only [lintegral]
refine ENNReal.biSup_add_biSup_le' (p := fun h : α →ₛ ℝ≥0∞ => h ≤ f)
(q := fun h : α →ₛ ℝ≥0∞ => h ≤ g) ⟨0, zero_le f⟩ ⟨0, zero_le g⟩ fun f' hf' g' hg' => ?_
exact le_iSup₂_of_le (f' + g') (add_le_add hf' hg') (add_lintegral _ _).ge
#align measure_theory.le_lintegral_add MeasureTheory.le_lintegral_add
-- Use stronger lemmas `lintegral_add_left`/`lintegral_add_right` instead
theorem lintegral_add_aux {f g : α → ℝ≥0∞} (hf : Measurable f) (hg : Measurable g) :
∫⁻ a, f a + g a ∂μ = ∫⁻ a, f a ∂μ + ∫⁻ a, g a ∂μ :=
calc
∫⁻ a, f a + g a ∂μ =
∫⁻ a, (⨆ n, (eapprox f n : α → ℝ≥0∞) a) + ⨆ n, (eapprox g n : α → ℝ≥0∞) a ∂μ := by
simp only [iSup_eapprox_apply, hf, hg]
_ = ∫⁻ a, ⨆ n, (eapprox f n + eapprox g n : α → ℝ≥0∞) a ∂μ := by
congr; funext a
rw [ENNReal.iSup_add_iSup_of_monotone]
· simp only [Pi.add_apply]
· intro i j h
exact monotone_eapprox _ h a
· intro i j h
exact monotone_eapprox _ h a
_ = ⨆ n, (eapprox f n).lintegral μ + (eapprox g n).lintegral μ := by
rw [lintegral_iSup]
· congr
funext n
rw [← SimpleFunc.add_lintegral, ← SimpleFunc.lintegral_eq_lintegral]
simp only [Pi.add_apply, SimpleFunc.coe_add]
· measurability
· intro i j h a
dsimp
gcongr <;> exact monotone_eapprox _ h _
_ = (⨆ n, (eapprox f n).lintegral μ) + ⨆ n, (eapprox g n).lintegral μ := by
refine (ENNReal.iSup_add_iSup_of_monotone ?_ ?_).symm <;>
· intro i j h
exact SimpleFunc.lintegral_mono (monotone_eapprox _ h) le_rfl
_ = ∫⁻ a, f a ∂μ + ∫⁻ a, g a ∂μ := by
rw [lintegral_eq_iSup_eapprox_lintegral hf, lintegral_eq_iSup_eapprox_lintegral hg]
#align measure_theory.lintegral_add_aux MeasureTheory.lintegral_add_aux
@[simp]
theorem lintegral_add_left {f : α → ℝ≥0∞} (hf : Measurable f) (g : α → ℝ≥0∞) :
∫⁻ a, f a + g a ∂μ = ∫⁻ a, f a ∂μ + ∫⁻ a, g a ∂μ := by
refine le_antisymm ?_ (le_lintegral_add _ _)
rcases exists_measurable_le_lintegral_eq μ fun a => f a + g a with ⟨φ, hφm, hφ_le, hφ_eq⟩
calc
∫⁻ a, f a + g a ∂μ = ∫⁻ a, φ a ∂μ := hφ_eq
_ ≤ ∫⁻ a, f a + (φ a - f a) ∂μ := lintegral_mono fun a => le_add_tsub
_ = ∫⁻ a, f a ∂μ + ∫⁻ a, φ a - f a ∂μ := lintegral_add_aux hf (hφm.sub hf)
_ ≤ ∫⁻ a, f a ∂μ + ∫⁻ a, g a ∂μ :=
add_le_add_left (lintegral_mono fun a => tsub_le_iff_left.2 <| hφ_le a) _
#align measure_theory.lintegral_add_left MeasureTheory.lintegral_add_left
theorem lintegral_add_left' {f : α → ℝ≥0∞} (hf : AEMeasurable f μ) (g : α → ℝ≥0∞) :
∫⁻ a, f a + g a ∂μ = ∫⁻ a, f a ∂μ + ∫⁻ a, g a ∂μ := by
rw [lintegral_congr_ae hf.ae_eq_mk, ← lintegral_add_left hf.measurable_mk,
lintegral_congr_ae (hf.ae_eq_mk.add (ae_eq_refl g))]
#align measure_theory.lintegral_add_left' MeasureTheory.lintegral_add_left'
theorem lintegral_add_right' (f : α → ℝ≥0∞) {g : α → ℝ≥0∞} (hg : AEMeasurable g μ) :
∫⁻ a, f a + g a ∂μ = ∫⁻ a, f a ∂μ + ∫⁻ a, g a ∂μ := by
simpa only [add_comm] using lintegral_add_left' hg f
#align measure_theory.lintegral_add_right' MeasureTheory.lintegral_add_right'
@[simp]
theorem lintegral_add_right (f : α → ℝ≥0∞) {g : α → ℝ≥0∞} (hg : Measurable g) :
∫⁻ a, f a + g a ∂μ = ∫⁻ a, f a ∂μ + ∫⁻ a, g a ∂μ :=
lintegral_add_right' f hg.aemeasurable
#align measure_theory.lintegral_add_right MeasureTheory.lintegral_add_right
@[simp]
theorem lintegral_smul_measure (c : ℝ≥0∞) (f : α → ℝ≥0∞) : ∫⁻ a, f a ∂c • μ = c * ∫⁻ a, f a ∂μ := by
simp only [lintegral, iSup_subtype', SimpleFunc.lintegral_smul, ENNReal.mul_iSup, smul_eq_mul]
#align measure_theory.lintegral_smul_measure MeasureTheory.lintegral_smul_measure
lemma set_lintegral_smul_measure (c : ℝ≥0∞) (f : α → ℝ≥0∞) (s : Set α) :
∫⁻ a in s, f a ∂(c • μ) = c * ∫⁻ a in s, f a ∂μ := by
rw [Measure.restrict_smul, lintegral_smul_measure]
@[simp]
theorem lintegral_sum_measure {m : MeasurableSpace α} {ι} (f : α → ℝ≥0∞) (μ : ι → Measure α) :
∫⁻ a, f a ∂Measure.sum μ = ∑' i, ∫⁻ a, f a ∂μ i := by
simp only [lintegral, iSup_subtype', SimpleFunc.lintegral_sum, ENNReal.tsum_eq_iSup_sum]
rw [iSup_comm]
congr; funext s
induction' s using Finset.induction_on with i s hi hs
· simp
simp only [Finset.sum_insert hi, ← hs]
refine (ENNReal.iSup_add_iSup ?_).symm
intro φ ψ
exact
⟨⟨φ ⊔ ψ, fun x => sup_le (φ.2 x) (ψ.2 x)⟩,
add_le_add (SimpleFunc.lintegral_mono le_sup_left le_rfl)
(Finset.sum_le_sum fun j _ => SimpleFunc.lintegral_mono le_sup_right le_rfl)⟩
#align measure_theory.lintegral_sum_measure MeasureTheory.lintegral_sum_measure
theorem hasSum_lintegral_measure {ι} {_ : MeasurableSpace α} (f : α → ℝ≥0∞) (μ : ι → Measure α) :
HasSum (fun i => ∫⁻ a, f a ∂μ i) (∫⁻ a, f a ∂Measure.sum μ) :=
(lintegral_sum_measure f μ).symm ▸ ENNReal.summable.hasSum
#align measure_theory.has_sum_lintegral_measure MeasureTheory.hasSum_lintegral_measure
@[simp]
theorem lintegral_add_measure {m : MeasurableSpace α} (f : α → ℝ≥0∞) (μ ν : Measure α) :
∫⁻ a, f a ∂(μ + ν) = ∫⁻ a, f a ∂μ + ∫⁻ a, f a ∂ν := by
simpa [tsum_fintype] using lintegral_sum_measure f fun b => cond b μ ν
#align measure_theory.lintegral_add_measure MeasureTheory.lintegral_add_measure
@[simp]
theorem lintegral_finset_sum_measure {ι} {m : MeasurableSpace α} (s : Finset ι) (f : α → ℝ≥0∞)
(μ : ι → Measure α) : ∫⁻ a, f a ∂(∑ i ∈ s, μ i) = ∑ i ∈ s, ∫⁻ a, f a ∂μ i := by
rw [← Measure.sum_coe_finset, lintegral_sum_measure, ← Finset.tsum_subtype']
simp only [Finset.coe_sort_coe]
#align measure_theory.lintegral_finset_sum_measure MeasureTheory.lintegral_finset_sum_measure
@[simp]
theorem lintegral_zero_measure {m : MeasurableSpace α} (f : α → ℝ≥0∞) :
∫⁻ a, f a ∂(0 : Measure α) = 0 := by
simp [lintegral]
#align measure_theory.lintegral_zero_measure MeasureTheory.lintegral_zero_measure
@[simp]
theorem lintegral_of_isEmpty {α} [MeasurableSpace α] [IsEmpty α] (μ : Measure α) (f : α → ℝ≥0∞) :
∫⁻ x, f x ∂μ = 0 := by
have : Subsingleton (Measure α) := inferInstance
convert lintegral_zero_measure f
theorem set_lintegral_empty (f : α → ℝ≥0∞) : ∫⁻ x in ∅, f x ∂μ = 0 := by
rw [Measure.restrict_empty, lintegral_zero_measure]
#align measure_theory.set_lintegral_empty MeasureTheory.set_lintegral_empty
theorem set_lintegral_univ (f : α → ℝ≥0∞) : ∫⁻ x in univ, f x ∂μ = ∫⁻ x, f x ∂μ := by
rw [Measure.restrict_univ]
#align measure_theory.set_lintegral_univ MeasureTheory.set_lintegral_univ
theorem set_lintegral_measure_zero (s : Set α) (f : α → ℝ≥0∞) (hs' : μ s = 0) :
∫⁻ x in s, f x ∂μ = 0 := by
convert lintegral_zero_measure _
exact Measure.restrict_eq_zero.2 hs'
#align measure_theory.set_lintegral_measure_zero MeasureTheory.set_lintegral_measure_zero
theorem lintegral_finset_sum' (s : Finset β) {f : β → α → ℝ≥0∞}
(hf : ∀ b ∈ s, AEMeasurable (f b) μ) :
∫⁻ a, ∑ b ∈ s, f b a ∂μ = ∑ b ∈ s, ∫⁻ a, f b a ∂μ := by
induction' s using Finset.induction_on with a s has ih
· simp
· simp only [Finset.sum_insert has]
rw [Finset.forall_mem_insert] at hf
rw [lintegral_add_left' hf.1, ih hf.2]
#align measure_theory.lintegral_finset_sum' MeasureTheory.lintegral_finset_sum'
theorem lintegral_finset_sum (s : Finset β) {f : β → α → ℝ≥0∞} (hf : ∀ b ∈ s, Measurable (f b)) :
∫⁻ a, ∑ b ∈ s, f b a ∂μ = ∑ b ∈ s, ∫⁻ a, f b a ∂μ :=
lintegral_finset_sum' s fun b hb => (hf b hb).aemeasurable
#align measure_theory.lintegral_finset_sum MeasureTheory.lintegral_finset_sum
@[simp]
theorem lintegral_const_mul (r : ℝ≥0∞) {f : α → ℝ≥0∞} (hf : Measurable f) :
∫⁻ a, r * f a ∂μ = r * ∫⁻ a, f a ∂μ :=
calc
∫⁻ a, r * f a ∂μ = ∫⁻ a, ⨆ n, (const α r * eapprox f n) a ∂μ := by
congr
funext a
rw [← iSup_eapprox_apply f hf, ENNReal.mul_iSup]
simp
_ = ⨆ n, r * (eapprox f n).lintegral μ := by
rw [lintegral_iSup]
· congr
funext n
rw [← SimpleFunc.const_mul_lintegral, ← SimpleFunc.lintegral_eq_lintegral]
· intro n
exact SimpleFunc.measurable _
· intro i j h a
exact mul_le_mul_left' (monotone_eapprox _ h _) _
_ = r * ∫⁻ a, f a ∂μ := by rw [← ENNReal.mul_iSup, lintegral_eq_iSup_eapprox_lintegral hf]
#align measure_theory.lintegral_const_mul MeasureTheory.lintegral_const_mul
theorem lintegral_const_mul'' (r : ℝ≥0∞) {f : α → ℝ≥0∞} (hf : AEMeasurable f μ) :
∫⁻ a, r * f a ∂μ = r * ∫⁻ a, f a ∂μ := by
have A : ∫⁻ a, f a ∂μ = ∫⁻ a, hf.mk f a ∂μ := lintegral_congr_ae hf.ae_eq_mk
have B : ∫⁻ a, r * f a ∂μ = ∫⁻ a, r * hf.mk f a ∂μ :=
lintegral_congr_ae (EventuallyEq.fun_comp hf.ae_eq_mk _)
rw [A, B, lintegral_const_mul _ hf.measurable_mk]
#align measure_theory.lintegral_const_mul'' MeasureTheory.lintegral_const_mul''
theorem lintegral_const_mul_le (r : ℝ≥0∞) (f : α → ℝ≥0∞) :
r * ∫⁻ a, f a ∂μ ≤ ∫⁻ a, r * f a ∂μ := by
rw [lintegral, ENNReal.mul_iSup]
refine iSup_le fun s => ?_
rw [ENNReal.mul_iSup, iSup_le_iff]
intro hs
rw [← SimpleFunc.const_mul_lintegral, lintegral]
refine le_iSup_of_le (const α r * s) (le_iSup_of_le (fun x => ?_) le_rfl)
exact mul_le_mul_left' (hs x) _
#align measure_theory.lintegral_const_mul_le MeasureTheory.lintegral_const_mul_le
theorem lintegral_const_mul' (r : ℝ≥0∞) (f : α → ℝ≥0∞) (hr : r ≠ ∞) :
∫⁻ a, r * f a ∂μ = r * ∫⁻ a, f a ∂μ := by
by_cases h : r = 0
· simp [h]
apply le_antisymm _ (lintegral_const_mul_le r f)
have rinv : r * r⁻¹ = 1 := ENNReal.mul_inv_cancel h hr
have rinv' : r⁻¹ * r = 1 := by
rw [mul_comm]
exact rinv
have := lintegral_const_mul_le (μ := μ) r⁻¹ fun x => r * f x
simp? [(mul_assoc _ _ _).symm, rinv'] at this says
simp only [(mul_assoc _ _ _).symm, rinv', one_mul] at this
simpa [(mul_assoc _ _ _).symm, rinv] using mul_le_mul_left' this r
#align measure_theory.lintegral_const_mul' MeasureTheory.lintegral_const_mul'
theorem lintegral_mul_const (r : ℝ≥0∞) {f : α → ℝ≥0∞} (hf : Measurable f) :
∫⁻ a, f a * r ∂μ = (∫⁻ a, f a ∂μ) * r := by simp_rw [mul_comm, lintegral_const_mul r hf]
#align measure_theory.lintegral_mul_const MeasureTheory.lintegral_mul_const
theorem lintegral_mul_const'' (r : ℝ≥0∞) {f : α → ℝ≥0∞} (hf : AEMeasurable f μ) :
∫⁻ a, f a * r ∂μ = (∫⁻ a, f a ∂μ) * r := by simp_rw [mul_comm, lintegral_const_mul'' r hf]
#align measure_theory.lintegral_mul_const'' MeasureTheory.lintegral_mul_const''
theorem lintegral_mul_const_le (r : ℝ≥0∞) (f : α → ℝ≥0∞) :
(∫⁻ a, f a ∂μ) * r ≤ ∫⁻ a, f a * r ∂μ := by
simp_rw [mul_comm, lintegral_const_mul_le r f]
#align measure_theory.lintegral_mul_const_le MeasureTheory.lintegral_mul_const_le
theorem lintegral_mul_const' (r : ℝ≥0∞) (f : α → ℝ≥0∞) (hr : r ≠ ∞) :
∫⁻ a, f a * r ∂μ = (∫⁻ a, f a ∂μ) * r := by simp_rw [mul_comm, lintegral_const_mul' r f hr]
#align measure_theory.lintegral_mul_const' MeasureTheory.lintegral_mul_const'
theorem lintegral_lintegral_mul {β} [MeasurableSpace β] {ν : Measure β} {f : α → ℝ≥0∞}
{g : β → ℝ≥0∞} (hf : AEMeasurable f μ) (hg : AEMeasurable g ν) :
∫⁻ x, ∫⁻ y, f x * g y ∂ν ∂μ = (∫⁻ x, f x ∂μ) * ∫⁻ y, g y ∂ν := by
simp [lintegral_const_mul'' _ hg, lintegral_mul_const'' _ hf]
#align measure_theory.lintegral_lintegral_mul MeasureTheory.lintegral_lintegral_mul
-- TODO: Need a better way of rewriting inside of an integral
theorem lintegral_rw₁ {f f' : α → β} (h : f =ᵐ[μ] f') (g : β → ℝ≥0∞) :
∫⁻ a, g (f a) ∂μ = ∫⁻ a, g (f' a) ∂μ :=
lintegral_congr_ae <| h.mono fun a h => by dsimp only; rw [h]
#align measure_theory.lintegral_rw₁ MeasureTheory.lintegral_rw₁
-- TODO: Need a better way of rewriting inside of an integral
theorem lintegral_rw₂ {f₁ f₁' : α → β} {f₂ f₂' : α → γ} (h₁ : f₁ =ᵐ[μ] f₁') (h₂ : f₂ =ᵐ[μ] f₂')
(g : β → γ → ℝ≥0∞) : ∫⁻ a, g (f₁ a) (f₂ a) ∂μ = ∫⁻ a, g (f₁' a) (f₂' a) ∂μ :=
lintegral_congr_ae <| h₁.mp <| h₂.mono fun _ h₂ h₁ => by dsimp only; rw [h₁, h₂]
#align measure_theory.lintegral_rw₂ MeasureTheory.lintegral_rw₂
theorem lintegral_indicator_le (f : α → ℝ≥0∞) (s : Set α) :
∫⁻ a, s.indicator f a ∂μ ≤ ∫⁻ a in s, f a ∂μ := by
simp only [lintegral]
apply iSup_le (fun g ↦ (iSup_le (fun hg ↦ ?_)))
have : g ≤ f := hg.trans (indicator_le_self s f)
refine le_iSup_of_le g (le_iSup_of_le this (le_of_eq ?_))
rw [lintegral_restrict, SimpleFunc.lintegral]
congr with t
by_cases H : t = 0
· simp [H]
congr with x
simp only [mem_preimage, mem_singleton_iff, mem_inter_iff, iff_self_and]
rintro rfl
contrapose! H
simpa [H] using hg x
@[simp]
theorem lintegral_indicator (f : α → ℝ≥0∞) {s : Set α} (hs : MeasurableSet s) :
∫⁻ a, s.indicator f a ∂μ = ∫⁻ a in s, f a ∂μ := by
apply le_antisymm (lintegral_indicator_le f s)
simp only [lintegral, ← restrict_lintegral_eq_lintegral_restrict _ hs, iSup_subtype']
refine iSup_mono' (Subtype.forall.2 fun φ hφ => ?_)
refine ⟨⟨φ.restrict s, fun x => ?_⟩, le_rfl⟩
simp [hφ x, hs, indicator_le_indicator]
#align measure_theory.lintegral_indicator MeasureTheory.lintegral_indicator
theorem lintegral_indicator₀ (f : α → ℝ≥0∞) {s : Set α} (hs : NullMeasurableSet s μ) :
∫⁻ a, s.indicator f a ∂μ = ∫⁻ a in s, f a ∂μ := by
rw [← lintegral_congr_ae (indicator_ae_eq_of_ae_eq_set hs.toMeasurable_ae_eq),
lintegral_indicator _ (measurableSet_toMeasurable _ _),
Measure.restrict_congr_set hs.toMeasurable_ae_eq]
#align measure_theory.lintegral_indicator₀ MeasureTheory.lintegral_indicator₀
theorem lintegral_indicator_const_le (s : Set α) (c : ℝ≥0∞) :
∫⁻ a, s.indicator (fun _ => c) a ∂μ ≤ c * μ s :=
(lintegral_indicator_le _ _).trans (set_lintegral_const s c).le
theorem lintegral_indicator_const₀ {s : Set α} (hs : NullMeasurableSet s μ) (c : ℝ≥0∞) :
∫⁻ a, s.indicator (fun _ => c) a ∂μ = c * μ s := by
rw [lintegral_indicator₀ _ hs, set_lintegral_const]
theorem lintegral_indicator_const {s : Set α} (hs : MeasurableSet s) (c : ℝ≥0∞) :
∫⁻ a, s.indicator (fun _ => c) a ∂μ = c * μ s :=
lintegral_indicator_const₀ hs.nullMeasurableSet c
#align measure_theory.lintegral_indicator_const MeasureTheory.lintegral_indicator_const
theorem set_lintegral_eq_const {f : α → ℝ≥0∞} (hf : Measurable f) (r : ℝ≥0∞) :
∫⁻ x in { x | f x = r }, f x ∂μ = r * μ { x | f x = r } := by
have : ∀ᵐ x ∂μ, x ∈ { x | f x = r } → f x = r := ae_of_all μ fun _ hx => hx
rw [set_lintegral_congr_fun _ this]
· rw [lintegral_const, Measure.restrict_apply MeasurableSet.univ, Set.univ_inter]
· exact hf (measurableSet_singleton r)
#align measure_theory.set_lintegral_eq_const MeasureTheory.set_lintegral_eq_const
theorem lintegral_indicator_one_le (s : Set α) : ∫⁻ a, s.indicator 1 a ∂μ ≤ μ s :=
(lintegral_indicator_const_le _ _).trans <| (one_mul _).le
@[simp]
theorem lintegral_indicator_one₀ (hs : NullMeasurableSet s μ) : ∫⁻ a, s.indicator 1 a ∂μ = μ s :=
(lintegral_indicator_const₀ hs _).trans <| one_mul _
@[simp]
theorem lintegral_indicator_one (hs : MeasurableSet s) : ∫⁻ a, s.indicator 1 a ∂μ = μ s :=
(lintegral_indicator_const hs _).trans <| one_mul _
#align measure_theory.lintegral_indicator_one MeasureTheory.lintegral_indicator_one
theorem lintegral_add_mul_meas_add_le_le_lintegral {f g : α → ℝ≥0∞} (hle : f ≤ᵐ[μ] g)
(hg : AEMeasurable g μ) (ε : ℝ≥0∞) :
∫⁻ a, f a ∂μ + ε * μ { x | f x + ε ≤ g x } ≤ ∫⁻ a, g a ∂μ := by
rcases exists_measurable_le_lintegral_eq μ f with ⟨φ, hφm, hφ_le, hφ_eq⟩
calc
∫⁻ x, f x ∂μ + ε * μ { x | f x + ε ≤ g x } = ∫⁻ x, φ x ∂μ + ε * μ { x | f x + ε ≤ g x } := by
rw [hφ_eq]
_ ≤ ∫⁻ x, φ x ∂μ + ε * μ { x | φ x + ε ≤ g x } := by
gcongr
exact fun x => (add_le_add_right (hφ_le _) _).trans
_ = ∫⁻ x, φ x + indicator { x | φ x + ε ≤ g x } (fun _ => ε) x ∂μ := by
rw [lintegral_add_left hφm, lintegral_indicator₀, set_lintegral_const]
exact measurableSet_le (hφm.nullMeasurable.measurable'.add_const _) hg.nullMeasurable
_ ≤ ∫⁻ x, g x ∂μ := lintegral_mono_ae (hle.mono fun x hx₁ => ?_)
simp only [indicator_apply]; split_ifs with hx₂
exacts [hx₂, (add_zero _).trans_le <| (hφ_le x).trans hx₁]
#align measure_theory.lintegral_add_mul_meas_add_le_le_lintegral MeasureTheory.lintegral_add_mul_meas_add_le_le_lintegral
theorem mul_meas_ge_le_lintegral₀ {f : α → ℝ≥0∞} (hf : AEMeasurable f μ) (ε : ℝ≥0∞) :
ε * μ { x | ε ≤ f x } ≤ ∫⁻ a, f a ∂μ := by
simpa only [lintegral_zero, zero_add] using
lintegral_add_mul_meas_add_le_le_lintegral (ae_of_all _ fun x => zero_le (f x)) hf ε
#align measure_theory.mul_meas_ge_le_lintegral₀ MeasureTheory.mul_meas_ge_le_lintegral₀
theorem mul_meas_ge_le_lintegral {f : α → ℝ≥0∞} (hf : Measurable f) (ε : ℝ≥0∞) :
ε * μ { x | ε ≤ f x } ≤ ∫⁻ a, f a ∂μ :=
mul_meas_ge_le_lintegral₀ hf.aemeasurable ε
#align measure_theory.mul_meas_ge_le_lintegral MeasureTheory.mul_meas_ge_le_lintegral
lemma meas_le_lintegral₀ {f : α → ℝ≥0∞} (hf : AEMeasurable f μ)
{s : Set α} (hs : ∀ x ∈ s, 1 ≤ f x) : μ s ≤ ∫⁻ a, f a ∂μ := by
apply le_trans _ (mul_meas_ge_le_lintegral₀ hf 1)
rw [one_mul]
exact measure_mono hs
lemma lintegral_le_meas {s : Set α} {f : α → ℝ≥0∞} (hf : ∀ a, f a ≤ 1) (h'f : ∀ a ∈ sᶜ, f a = 0) :
∫⁻ a, f a ∂μ ≤ μ s := by
apply (lintegral_mono (fun x ↦ ?_)).trans (lintegral_indicator_one_le s)
by_cases hx : x ∈ s
· simpa [hx] using hf x
· simpa [hx] using h'f x hx
theorem lintegral_eq_top_of_measure_eq_top_ne_zero {f : α → ℝ≥0∞} (hf : AEMeasurable f μ)
(hμf : μ {x | f x = ∞} ≠ 0) : ∫⁻ x, f x ∂μ = ∞ :=
eq_top_iff.mpr <|
calc
∞ = ∞ * μ { x | ∞ ≤ f x } := by simp [mul_eq_top, hμf]
_ ≤ ∫⁻ x, f x ∂μ := mul_meas_ge_le_lintegral₀ hf ∞
#align measure_theory.lintegral_eq_top_of_measure_eq_top_ne_zero MeasureTheory.lintegral_eq_top_of_measure_eq_top_ne_zero
theorem setLintegral_eq_top_of_measure_eq_top_ne_zero (hf : AEMeasurable f (μ.restrict s))
(hμf : μ ({x ∈ s | f x = ∞}) ≠ 0) : ∫⁻ x in s, f x ∂μ = ∞ :=
lintegral_eq_top_of_measure_eq_top_ne_zero hf <|
mt (eq_bot_mono <| by rw [← setOf_inter_eq_sep]; exact Measure.le_restrict_apply _ _) hμf
#align measure_theory.set_lintegral_eq_top_of_measure_eq_top_ne_zero MeasureTheory.setLintegral_eq_top_of_measure_eq_top_ne_zero
theorem measure_eq_top_of_lintegral_ne_top (hf : AEMeasurable f μ) (hμf : ∫⁻ x, f x ∂μ ≠ ∞) :
μ {x | f x = ∞} = 0 :=
of_not_not fun h => hμf <| lintegral_eq_top_of_measure_eq_top_ne_zero hf h
#align measure_theory.measure_eq_top_of_lintegral_ne_top MeasureTheory.measure_eq_top_of_lintegral_ne_top
theorem measure_eq_top_of_setLintegral_ne_top (hf : AEMeasurable f (μ.restrict s))
(hμf : ∫⁻ x in s, f x ∂μ ≠ ∞) : μ ({x ∈ s | f x = ∞}) = 0 :=
of_not_not fun h => hμf <| setLintegral_eq_top_of_measure_eq_top_ne_zero hf h
#align measure_theory.measure_eq_top_of_set_lintegral_ne_top MeasureTheory.measure_eq_top_of_setLintegral_ne_top
theorem meas_ge_le_lintegral_div {f : α → ℝ≥0∞} (hf : AEMeasurable f μ) {ε : ℝ≥0∞} (hε : ε ≠ 0)
(hε' : ε ≠ ∞) : μ { x | ε ≤ f x } ≤ (∫⁻ a, f a ∂μ) / ε :=
(ENNReal.le_div_iff_mul_le (Or.inl hε) (Or.inl hε')).2 <| by
rw [mul_comm]
exact mul_meas_ge_le_lintegral₀ hf ε
#align measure_theory.meas_ge_le_lintegral_div MeasureTheory.meas_ge_le_lintegral_div
theorem ae_eq_of_ae_le_of_lintegral_le {f g : α → ℝ≥0∞} (hfg : f ≤ᵐ[μ] g) (hf : ∫⁻ x, f x ∂μ ≠ ∞)
(hg : AEMeasurable g μ) (hgf : ∫⁻ x, g x ∂μ ≤ ∫⁻ x, f x ∂μ) : f =ᵐ[μ] g := by
have : ∀ n : ℕ, ∀ᵐ x ∂μ, g x < f x + (n : ℝ≥0∞)⁻¹ := by
intro n
simp only [ae_iff, not_lt]
have : ∫⁻ x, f x ∂μ + (↑n)⁻¹ * μ { x : α | f x + (n : ℝ≥0∞)⁻¹ ≤ g x } ≤ ∫⁻ x, f x ∂μ :=
(lintegral_add_mul_meas_add_le_le_lintegral hfg hg n⁻¹).trans hgf
rw [(ENNReal.cancel_of_ne hf).add_le_iff_nonpos_right, nonpos_iff_eq_zero, mul_eq_zero] at this
exact this.resolve_left (ENNReal.inv_ne_zero.2 (ENNReal.natCast_ne_top _))
refine hfg.mp ((ae_all_iff.2 this).mono fun x hlt hle => hle.antisymm ?_)
suffices Tendsto (fun n : ℕ => f x + (n : ℝ≥0∞)⁻¹) atTop (𝓝 (f x)) from
ge_of_tendsto' this fun i => (hlt i).le
simpa only [inv_top, add_zero] using
tendsto_const_nhds.add (ENNReal.tendsto_inv_iff.2 ENNReal.tendsto_nat_nhds_top)
#align measure_theory.ae_eq_of_ae_le_of_lintegral_le MeasureTheory.ae_eq_of_ae_le_of_lintegral_le
@[simp]
theorem lintegral_eq_zero_iff' {f : α → ℝ≥0∞} (hf : AEMeasurable f μ) :
∫⁻ a, f a ∂μ = 0 ↔ f =ᵐ[μ] 0 :=
have : ∫⁻ _ : α, 0 ∂μ ≠ ∞ := by simp [lintegral_zero, zero_ne_top]
⟨fun h =>
(ae_eq_of_ae_le_of_lintegral_le (ae_of_all _ <| zero_le f) this hf
(h.trans lintegral_zero.symm).le).symm,
fun h => (lintegral_congr_ae h).trans lintegral_zero⟩
#align measure_theory.lintegral_eq_zero_iff' MeasureTheory.lintegral_eq_zero_iff'
@[simp]
theorem lintegral_eq_zero_iff {f : α → ℝ≥0∞} (hf : Measurable f) : ∫⁻ a, f a ∂μ = 0 ↔ f =ᵐ[μ] 0 :=
lintegral_eq_zero_iff' hf.aemeasurable
#align measure_theory.lintegral_eq_zero_iff MeasureTheory.lintegral_eq_zero_iff
theorem lintegral_pos_iff_support {f : α → ℝ≥0∞} (hf : Measurable f) :
(0 < ∫⁻ a, f a ∂μ) ↔ 0 < μ (Function.support f) := by
simp [pos_iff_ne_zero, hf, Filter.EventuallyEq, ae_iff, Function.support]
#align measure_theory.lintegral_pos_iff_support MeasureTheory.lintegral_pos_iff_support
theorem setLintegral_pos_iff {f : α → ℝ≥0∞} (hf : Measurable f) {s : Set α} :
0 < ∫⁻ a in s, f a ∂μ ↔ 0 < μ (Function.support f ∩ s) := by
rw [lintegral_pos_iff_support hf, Measure.restrict_apply (measurableSet_support hf)]
theorem lintegral_iSup_ae {f : ℕ → α → ℝ≥0∞} (hf : ∀ n, Measurable (f n))
(h_mono : ∀ n, ∀ᵐ a ∂μ, f n a ≤ f n.succ a) : ∫⁻ a, ⨆ n, f n a ∂μ = ⨆ n, ∫⁻ a, f n a ∂μ := by
let ⟨s, hs⟩ := exists_measurable_superset_of_null (ae_iff.1 (ae_all_iff.2 h_mono))
let g n a := if a ∈ s then 0 else f n a
have g_eq_f : ∀ᵐ a ∂μ, ∀ n, g n a = f n a :=
(measure_zero_iff_ae_nmem.1 hs.2.2).mono fun a ha n => if_neg ha
calc
∫⁻ a, ⨆ n, f n a ∂μ = ∫⁻ a, ⨆ n, g n a ∂μ :=
lintegral_congr_ae <| g_eq_f.mono fun a ha => by simp only [ha]
_ = ⨆ n, ∫⁻ a, g n a ∂μ :=
(lintegral_iSup (fun n => measurable_const.piecewise hs.2.1 (hf n))
(monotone_nat_of_le_succ fun n a => ?_))
_ = ⨆ n, ∫⁻ a, f n a ∂μ := by simp only [lintegral_congr_ae (g_eq_f.mono fun _a ha => ha _)]
simp only [g]
split_ifs with h
· rfl
· have := Set.not_mem_subset hs.1 h
simp only [not_forall, not_le, mem_setOf_eq, not_exists, not_lt] at this
exact this n
#align measure_theory.lintegral_supr_ae MeasureTheory.lintegral_iSup_ae
theorem lintegral_sub' {f g : α → ℝ≥0∞} (hg : AEMeasurable g μ) (hg_fin : ∫⁻ a, g a ∂μ ≠ ∞)
(h_le : g ≤ᵐ[μ] f) : ∫⁻ a, f a - g a ∂μ = ∫⁻ a, f a ∂μ - ∫⁻ a, g a ∂μ := by
refine ENNReal.eq_sub_of_add_eq hg_fin ?_
rw [← lintegral_add_right' _ hg]
exact lintegral_congr_ae (h_le.mono fun x hx => tsub_add_cancel_of_le hx)
#align measure_theory.lintegral_sub' MeasureTheory.lintegral_sub'
theorem lintegral_sub {f g : α → ℝ≥0∞} (hg : Measurable g) (hg_fin : ∫⁻ a, g a ∂μ ≠ ∞)
(h_le : g ≤ᵐ[μ] f) : ∫⁻ a, f a - g a ∂μ = ∫⁻ a, f a ∂μ - ∫⁻ a, g a ∂μ :=
lintegral_sub' hg.aemeasurable hg_fin h_le
#align measure_theory.lintegral_sub MeasureTheory.lintegral_sub
theorem lintegral_sub_le' (f g : α → ℝ≥0∞) (hf : AEMeasurable f μ) :
∫⁻ x, g x ∂μ - ∫⁻ x, f x ∂μ ≤ ∫⁻ x, g x - f x ∂μ := by
rw [tsub_le_iff_right]
by_cases hfi : ∫⁻ x, f x ∂μ = ∞
· rw [hfi, add_top]
exact le_top
· rw [← lintegral_add_right' _ hf]
gcongr
exact le_tsub_add
#align measure_theory.lintegral_sub_le' MeasureTheory.lintegral_sub_le'
theorem lintegral_sub_le (f g : α → ℝ≥0∞) (hf : Measurable f) :
∫⁻ x, g x ∂μ - ∫⁻ x, f x ∂μ ≤ ∫⁻ x, g x - f x ∂μ :=
lintegral_sub_le' f g hf.aemeasurable
#align measure_theory.lintegral_sub_le MeasureTheory.lintegral_sub_le
theorem lintegral_strict_mono_of_ae_le_of_frequently_ae_lt {f g : α → ℝ≥0∞} (hg : AEMeasurable g μ)
(hfi : ∫⁻ x, f x ∂μ ≠ ∞) (h_le : f ≤ᵐ[μ] g) (h : ∃ᵐ x ∂μ, f x ≠ g x) :
∫⁻ x, f x ∂μ < ∫⁻ x, g x ∂μ := by
contrapose! h
simp only [not_frequently, Ne, Classical.not_not]
exact ae_eq_of_ae_le_of_lintegral_le h_le hfi hg h
#align measure_theory.lintegral_strict_mono_of_ae_le_of_frequently_ae_lt MeasureTheory.lintegral_strict_mono_of_ae_le_of_frequently_ae_lt
theorem lintegral_strict_mono_of_ae_le_of_ae_lt_on {f g : α → ℝ≥0∞} (hg : AEMeasurable g μ)
(hfi : ∫⁻ x, f x ∂μ ≠ ∞) (h_le : f ≤ᵐ[μ] g) {s : Set α} (hμs : μ s ≠ 0)
(h : ∀ᵐ x ∂μ, x ∈ s → f x < g x) : ∫⁻ x, f x ∂μ < ∫⁻ x, g x ∂μ :=
lintegral_strict_mono_of_ae_le_of_frequently_ae_lt hg hfi h_le <|
((frequently_ae_mem_iff.2 hμs).and_eventually h).mono fun _x hx => (hx.2 hx.1).ne
#align measure_theory.lintegral_strict_mono_of_ae_le_of_ae_lt_on MeasureTheory.lintegral_strict_mono_of_ae_le_of_ae_lt_on
theorem lintegral_strict_mono {f g : α → ℝ≥0∞} (hμ : μ ≠ 0) (hg : AEMeasurable g μ)
(hfi : ∫⁻ x, f x ∂μ ≠ ∞) (h : ∀ᵐ x ∂μ, f x < g x) : ∫⁻ x, f x ∂μ < ∫⁻ x, g x ∂μ := by
rw [Ne, ← Measure.measure_univ_eq_zero] at hμ
refine lintegral_strict_mono_of_ae_le_of_ae_lt_on hg hfi (ae_le_of_ae_lt h) hμ ?_
simpa using h
#align measure_theory.lintegral_strict_mono MeasureTheory.lintegral_strict_mono
theorem set_lintegral_strict_mono {f g : α → ℝ≥0∞} {s : Set α} (hsm : MeasurableSet s)
(hs : μ s ≠ 0) (hg : Measurable g) (hfi : ∫⁻ x in s, f x ∂μ ≠ ∞)
(h : ∀ᵐ x ∂μ, x ∈ s → f x < g x) : ∫⁻ x in s, f x ∂μ < ∫⁻ x in s, g x ∂μ :=
lintegral_strict_mono (by simp [hs]) hg.aemeasurable hfi ((ae_restrict_iff' hsm).mpr h)
#align measure_theory.set_lintegral_strict_mono MeasureTheory.set_lintegral_strict_mono
theorem lintegral_iInf_ae {f : ℕ → α → ℝ≥0∞} (h_meas : ∀ n, Measurable (f n))
(h_mono : ∀ n : ℕ, f n.succ ≤ᵐ[μ] f n) (h_fin : ∫⁻ a, f 0 a ∂μ ≠ ∞) :
∫⁻ a, ⨅ n, f n a ∂μ = ⨅ n, ∫⁻ a, f n a ∂μ :=
have fn_le_f0 : ∫⁻ a, ⨅ n, f n a ∂μ ≤ ∫⁻ a, f 0 a ∂μ :=
lintegral_mono fun a => iInf_le_of_le 0 le_rfl
have fn_le_f0' : ⨅ n, ∫⁻ a, f n a ∂μ ≤ ∫⁻ a, f 0 a ∂μ := iInf_le_of_le 0 le_rfl
(ENNReal.sub_right_inj h_fin fn_le_f0 fn_le_f0').1 <|
show ∫⁻ a, f 0 a ∂μ - ∫⁻ a, ⨅ n, f n a ∂μ = ∫⁻ a, f 0 a ∂μ - ⨅ n, ∫⁻ a, f n a ∂μ from
calc
∫⁻ a, f 0 a ∂μ - ∫⁻ a, ⨅ n, f n a ∂μ = ∫⁻ a, f 0 a - ⨅ n, f n a ∂μ :=
(lintegral_sub (measurable_iInf h_meas)
(ne_top_of_le_ne_top h_fin <| lintegral_mono fun a => iInf_le _ _)
(ae_of_all _ fun a => iInf_le _ _)).symm
_ = ∫⁻ a, ⨆ n, f 0 a - f n a ∂μ := congr rfl (funext fun a => ENNReal.sub_iInf)
_ = ⨆ n, ∫⁻ a, f 0 a - f n a ∂μ :=
(lintegral_iSup_ae (fun n => (h_meas 0).sub (h_meas n)) fun n =>
(h_mono n).mono fun a ha => tsub_le_tsub le_rfl ha)
_ = ⨆ n, ∫⁻ a, f 0 a ∂μ - ∫⁻ a, f n a ∂μ :=
(have h_mono : ∀ᵐ a ∂μ, ∀ n : ℕ, f n.succ a ≤ f n a := ae_all_iff.2 h_mono
have h_mono : ∀ n, ∀ᵐ a ∂μ, f n a ≤ f 0 a := fun n =>
h_mono.mono fun a h => by
induction' n with n ih
· exact le_rfl
· exact le_trans (h n) ih
congr_arg iSup <|
funext fun n =>
lintegral_sub (h_meas _) (ne_top_of_le_ne_top h_fin <| lintegral_mono_ae <| h_mono n)
(h_mono n))
_ = ∫⁻ a, f 0 a ∂μ - ⨅ n, ∫⁻ a, f n a ∂μ := ENNReal.sub_iInf.symm
#align measure_theory.lintegral_infi_ae MeasureTheory.lintegral_iInf_ae
theorem lintegral_iInf {f : ℕ → α → ℝ≥0∞} (h_meas : ∀ n, Measurable (f n)) (h_anti : Antitone f)
(h_fin : ∫⁻ a, f 0 a ∂μ ≠ ∞) : ∫⁻ a, ⨅ n, f n a ∂μ = ⨅ n, ∫⁻ a, f n a ∂μ :=
lintegral_iInf_ae h_meas (fun n => ae_of_all _ <| h_anti n.le_succ) h_fin
#align measure_theory.lintegral_infi MeasureTheory.lintegral_iInf
theorem lintegral_iInf' {f : ℕ → α → ℝ≥0∞} (h_meas : ∀ n, AEMeasurable (f n) μ)
(h_anti : ∀ᵐ a ∂μ, Antitone (fun i ↦ f i a)) (h_fin : ∫⁻ a, f 0 a ∂μ ≠ ∞) :
∫⁻ a, ⨅ n, f n a ∂μ = ⨅ n, ∫⁻ a, f n a ∂μ := by
simp_rw [← iInf_apply]
let p : α → (ℕ → ℝ≥0∞) → Prop := fun _ f' => Antitone f'
have hp : ∀ᵐ x ∂μ, p x fun i => f i x := h_anti
have h_ae_seq_mono : Antitone (aeSeq h_meas p) := by
intro n m hnm x
by_cases hx : x ∈ aeSeqSet h_meas p
· exact aeSeq.prop_of_mem_aeSeqSet h_meas hx hnm
· simp only [aeSeq, hx, if_false]
exact le_rfl
rw [lintegral_congr_ae (aeSeq.iInf h_meas hp).symm]
simp_rw [iInf_apply]
rw [lintegral_iInf (aeSeq.measurable h_meas p) h_ae_seq_mono]
· congr
exact funext fun n ↦ lintegral_congr_ae (aeSeq.aeSeq_n_eq_fun_n_ae h_meas hp n)
· rwa [lintegral_congr_ae (aeSeq.aeSeq_n_eq_fun_n_ae h_meas hp 0)]
theorem lintegral_iInf_directed_of_measurable {mα : MeasurableSpace α} [Countable β]
{f : β → α → ℝ≥0∞} {μ : Measure α} (hμ : μ ≠ 0) (hf : ∀ b, Measurable (f b))
(hf_int : ∀ b, ∫⁻ a, f b a ∂μ ≠ ∞) (h_directed : Directed (· ≥ ·) f) :
∫⁻ a, ⨅ b, f b a ∂μ = ⨅ b, ∫⁻ a, f b a ∂μ := by
cases nonempty_encodable β
cases isEmpty_or_nonempty β
· simp only [iInf_of_empty, lintegral_const,
ENNReal.top_mul (Measure.measure_univ_ne_zero.mpr hμ)]
inhabit β
have : ∀ a, ⨅ b, f b a = ⨅ n, f (h_directed.sequence f n) a := by
refine fun a =>
le_antisymm (le_iInf fun n => iInf_le _ _)
(le_iInf fun b => iInf_le_of_le (Encodable.encode b + 1) ?_)
exact h_directed.sequence_le b a
-- Porting note: used `∘` below to deal with its reduced reducibility
calc
∫⁻ a, ⨅ b, f b a ∂μ
_ = ∫⁻ a, ⨅ n, (f ∘ h_directed.sequence f) n a ∂μ := by simp only [this, Function.comp_apply]
_ = ⨅ n, ∫⁻ a, (f ∘ h_directed.sequence f) n a ∂μ := by
rw [lintegral_iInf ?_ h_directed.sequence_anti]
· exact hf_int _
· exact fun n => hf _
_ = ⨅ b, ∫⁻ a, f b a ∂μ := by
refine le_antisymm (le_iInf fun b => ?_) (le_iInf fun n => ?_)
· exact iInf_le_of_le (Encodable.encode b + 1) (lintegral_mono <| h_directed.sequence_le b)
· exact iInf_le (fun b => ∫⁻ a, f b a ∂μ) _
#align lintegral_infi_directed_of_measurable MeasureTheory.lintegral_iInf_directed_of_measurable
theorem lintegral_liminf_le' {f : ℕ → α → ℝ≥0∞} (h_meas : ∀ n, AEMeasurable (f n) μ) :
∫⁻ a, liminf (fun n => f n a) atTop ∂μ ≤ liminf (fun n => ∫⁻ a, f n a ∂μ) atTop :=
calc
∫⁻ a, liminf (fun n => f n a) atTop ∂μ = ∫⁻ a, ⨆ n : ℕ, ⨅ i ≥ n, f i a ∂μ := by
simp only [liminf_eq_iSup_iInf_of_nat]
_ = ⨆ n : ℕ, ∫⁻ a, ⨅ i ≥ n, f i a ∂μ :=
(lintegral_iSup' (fun n => aemeasurable_biInf _ (to_countable _) (fun i _ ↦ h_meas i))
(ae_of_all μ fun a n m hnm => iInf_le_iInf_of_subset fun i hi => le_trans hnm hi))
_ ≤ ⨆ n : ℕ, ⨅ i ≥ n, ∫⁻ a, f i a ∂μ := iSup_mono fun n => le_iInf₂_lintegral _
_ = atTop.liminf fun n => ∫⁻ a, f n a ∂μ := Filter.liminf_eq_iSup_iInf_of_nat.symm
#align measure_theory.lintegral_liminf_le' MeasureTheory.lintegral_liminf_le'
theorem lintegral_liminf_le {f : ℕ → α → ℝ≥0∞} (h_meas : ∀ n, Measurable (f n)) :
∫⁻ a, liminf (fun n => f n a) atTop ∂μ ≤ liminf (fun n => ∫⁻ a, f n a ∂μ) atTop :=
lintegral_liminf_le' fun n => (h_meas n).aemeasurable
#align measure_theory.lintegral_liminf_le MeasureTheory.lintegral_liminf_le
theorem limsup_lintegral_le {f : ℕ → α → ℝ≥0∞} {g : α → ℝ≥0∞} (hf_meas : ∀ n, Measurable (f n))
(h_bound : ∀ n, f n ≤ᵐ[μ] g) (h_fin : ∫⁻ a, g a ∂μ ≠ ∞) :
limsup (fun n => ∫⁻ a, f n a ∂μ) atTop ≤ ∫⁻ a, limsup (fun n => f n a) atTop ∂μ :=
calc
limsup (fun n => ∫⁻ a, f n a ∂μ) atTop = ⨅ n : ℕ, ⨆ i ≥ n, ∫⁻ a, f i a ∂μ :=
limsup_eq_iInf_iSup_of_nat
_ ≤ ⨅ n : ℕ, ∫⁻ a, ⨆ i ≥ n, f i a ∂μ := iInf_mono fun n => iSup₂_lintegral_le _
_ = ∫⁻ a, ⨅ n : ℕ, ⨆ i ≥ n, f i a ∂μ := by
refine (lintegral_iInf ?_ ?_ ?_).symm
· intro n
exact measurable_biSup _ (to_countable _) (fun i _ ↦ hf_meas i)
· intro n m hnm a
exact iSup_le_iSup_of_subset fun i hi => le_trans hnm hi
· refine ne_top_of_le_ne_top h_fin (lintegral_mono_ae ?_)
refine (ae_all_iff.2 h_bound).mono fun n hn => ?_
exact iSup_le fun i => iSup_le fun _ => hn i
_ = ∫⁻ a, limsup (fun n => f n a) atTop ∂μ := by simp only [limsup_eq_iInf_iSup_of_nat]
#align measure_theory.limsup_lintegral_le MeasureTheory.limsup_lintegral_le
theorem tendsto_lintegral_of_dominated_convergence {F : ℕ → α → ℝ≥0∞} {f : α → ℝ≥0∞}
(bound : α → ℝ≥0∞) (hF_meas : ∀ n, Measurable (F n)) (h_bound : ∀ n, F n ≤ᵐ[μ] bound)
(h_fin : ∫⁻ a, bound a ∂μ ≠ ∞) (h_lim : ∀ᵐ a ∂μ, Tendsto (fun n => F n a) atTop (𝓝 (f a))) :
Tendsto (fun n => ∫⁻ a, F n a ∂μ) atTop (𝓝 (∫⁻ a, f a ∂μ)) :=
tendsto_of_le_liminf_of_limsup_le
(calc
∫⁻ a, f a ∂μ = ∫⁻ a, liminf (fun n : ℕ => F n a) atTop ∂μ :=
lintegral_congr_ae <| h_lim.mono fun a h => h.liminf_eq.symm
_ ≤ liminf (fun n => ∫⁻ a, F n a ∂μ) atTop := lintegral_liminf_le hF_meas
)
(calc
limsup (fun n : ℕ => ∫⁻ a, F n a ∂μ) atTop ≤ ∫⁻ a, limsup (fun n => F n a) atTop ∂μ :=
limsup_lintegral_le hF_meas h_bound h_fin
_ = ∫⁻ a, f a ∂μ := lintegral_congr_ae <| h_lim.mono fun a h => h.limsup_eq
)
#align measure_theory.tendsto_lintegral_of_dominated_convergence MeasureTheory.tendsto_lintegral_of_dominated_convergence
theorem tendsto_lintegral_of_dominated_convergence' {F : ℕ → α → ℝ≥0∞} {f : α → ℝ≥0∞}
(bound : α → ℝ≥0∞) (hF_meas : ∀ n, AEMeasurable (F n) μ) (h_bound : ∀ n, F n ≤ᵐ[μ] bound)
(h_fin : ∫⁻ a, bound a ∂μ ≠ ∞) (h_lim : ∀ᵐ a ∂μ, Tendsto (fun n => F n a) atTop (𝓝 (f a))) :
Tendsto (fun n => ∫⁻ a, F n a ∂μ) atTop (𝓝 (∫⁻ a, f a ∂μ)) := by
have : ∀ n, ∫⁻ a, F n a ∂μ = ∫⁻ a, (hF_meas n).mk (F n) a ∂μ := fun n =>
lintegral_congr_ae (hF_meas n).ae_eq_mk
simp_rw [this]
apply
tendsto_lintegral_of_dominated_convergence bound (fun n => (hF_meas n).measurable_mk) _ h_fin
· have : ∀ n, ∀ᵐ a ∂μ, (hF_meas n).mk (F n) a = F n a := fun n => (hF_meas n).ae_eq_mk.symm
have : ∀ᵐ a ∂μ, ∀ n, (hF_meas n).mk (F n) a = F n a := ae_all_iff.mpr this
filter_upwards [this, h_lim] with a H H'
simp_rw [H]
exact H'
· intro n
filter_upwards [h_bound n, (hF_meas n).ae_eq_mk] with a H H'
rwa [H'] at H
#align measure_theory.tendsto_lintegral_of_dominated_convergence' MeasureTheory.tendsto_lintegral_of_dominated_convergence'
theorem tendsto_lintegral_filter_of_dominated_convergence {ι} {l : Filter ι}
[l.IsCountablyGenerated] {F : ι → α → ℝ≥0∞} {f : α → ℝ≥0∞} (bound : α → ℝ≥0∞)
(hF_meas : ∀ᶠ n in l, Measurable (F n)) (h_bound : ∀ᶠ n in l, ∀ᵐ a ∂μ, F n a ≤ bound a)
(h_fin : ∫⁻ a, bound a ∂μ ≠ ∞) (h_lim : ∀ᵐ a ∂μ, Tendsto (fun n => F n a) l (𝓝 (f a))) :
Tendsto (fun n => ∫⁻ a, F n a ∂μ) l (𝓝 <| ∫⁻ a, f a ∂μ) := by
rw [tendsto_iff_seq_tendsto]
intro x xl
have hxl := by
rw [tendsto_atTop'] at xl
exact xl
have h := inter_mem hF_meas h_bound
replace h := hxl _ h
rcases h with ⟨k, h⟩
rw [← tendsto_add_atTop_iff_nat k]
refine tendsto_lintegral_of_dominated_convergence ?_ ?_ ?_ ?_ ?_
· exact bound
· intro
refine (h _ ?_).1
exact Nat.le_add_left _ _
· intro
refine (h _ ?_).2
exact Nat.le_add_left _ _
· assumption
· refine h_lim.mono fun a h_lim => ?_
apply @Tendsto.comp _ _ _ (fun n => x (n + k)) fun n => F n a
· assumption
rw [tendsto_add_atTop_iff_nat]
assumption
#align measure_theory.tendsto_lintegral_filter_of_dominated_convergence MeasureTheory.tendsto_lintegral_filter_of_dominated_convergence
theorem lintegral_tendsto_of_tendsto_of_antitone {f : ℕ → α → ℝ≥0∞} {F : α → ℝ≥0∞}
(hf : ∀ n, AEMeasurable (f n) μ) (h_anti : ∀ᵐ x ∂μ, Antitone fun n ↦ f n x)
(h0 : ∫⁻ a, f 0 a ∂μ ≠ ∞)
(h_tendsto : ∀ᵐ x ∂μ, Tendsto (fun n ↦ f n x) atTop (𝓝 (F x))) :
Tendsto (fun n ↦ ∫⁻ x, f n x ∂μ) atTop (𝓝 (∫⁻ x, F x ∂μ)) := by
have : Antitone fun n ↦ ∫⁻ x, f n x ∂μ := fun i j hij ↦
lintegral_mono_ae (h_anti.mono fun x hx ↦ hx hij)
suffices key : ∫⁻ x, F x ∂μ = ⨅ n, ∫⁻ x, f n x ∂μ by
rw [key]
exact tendsto_atTop_iInf this
rw [← lintegral_iInf' hf h_anti h0]
refine lintegral_congr_ae ?_
filter_upwards [h_anti, h_tendsto] with _ hx_anti hx_tendsto
using tendsto_nhds_unique hx_tendsto (tendsto_atTop_iInf hx_anti)
section
open Encodable
theorem lintegral_iSup_directed_of_measurable [Countable β] {f : β → α → ℝ≥0∞}
(hf : ∀ b, Measurable (f b)) (h_directed : Directed (· ≤ ·) f) :
∫⁻ a, ⨆ b, f b a ∂μ = ⨆ b, ∫⁻ a, f b a ∂μ := by
cases nonempty_encodable β
cases isEmpty_or_nonempty β
· simp [iSup_of_empty]
inhabit β
have : ∀ a, ⨆ b, f b a = ⨆ n, f (h_directed.sequence f n) a := by
intro a
refine le_antisymm (iSup_le fun b => ?_) (iSup_le fun n => le_iSup (fun n => f n a) _)
exact le_iSup_of_le (encode b + 1) (h_directed.le_sequence b a)
calc
∫⁻ a, ⨆ b, f b a ∂μ = ∫⁻ a, ⨆ n, f (h_directed.sequence f n) a ∂μ := by simp only [this]
_ = ⨆ n, ∫⁻ a, f (h_directed.sequence f n) a ∂μ :=
(lintegral_iSup (fun n => hf _) h_directed.sequence_mono)
_ = ⨆ b, ∫⁻ a, f b a ∂μ := by
refine le_antisymm (iSup_le fun n => ?_) (iSup_le fun b => ?_)
· exact le_iSup (fun b => ∫⁻ a, f b a ∂μ) _
· exact le_iSup_of_le (encode b + 1) (lintegral_mono <| h_directed.le_sequence b)
#align measure_theory.lintegral_supr_directed_of_measurable MeasureTheory.lintegral_iSup_directed_of_measurable
theorem lintegral_iSup_directed [Countable β] {f : β → α → ℝ≥0∞} (hf : ∀ b, AEMeasurable (f b) μ)
(h_directed : Directed (· ≤ ·) f) : ∫⁻ a, ⨆ b, f b a ∂μ = ⨆ b, ∫⁻ a, f b a ∂μ := by
simp_rw [← iSup_apply]
let p : α → (β → ENNReal) → Prop := fun x f' => Directed LE.le f'
have hp : ∀ᵐ x ∂μ, p x fun i => f i x := by
filter_upwards [] with x i j
obtain ⟨z, hz₁, hz₂⟩ := h_directed i j
exact ⟨z, hz₁ x, hz₂ x⟩
have h_ae_seq_directed : Directed LE.le (aeSeq hf p) := by
intro b₁ b₂
obtain ⟨z, hz₁, hz₂⟩ := h_directed b₁ b₂
refine ⟨z, ?_, ?_⟩ <;>
· intro x
by_cases hx : x ∈ aeSeqSet hf p
· repeat rw [aeSeq.aeSeq_eq_fun_of_mem_aeSeqSet hf hx]
apply_rules [hz₁, hz₂]
· simp only [aeSeq, hx, if_false]
exact le_rfl
convert lintegral_iSup_directed_of_measurable (aeSeq.measurable hf p) h_ae_seq_directed using 1
· simp_rw [← iSup_apply]
rw [lintegral_congr_ae (aeSeq.iSup hf hp).symm]
· congr 1
ext1 b
rw [lintegral_congr_ae]
apply EventuallyEq.symm
exact aeSeq.aeSeq_n_eq_fun_n_ae hf hp _
#align measure_theory.lintegral_supr_directed MeasureTheory.lintegral_iSup_directed
end
theorem lintegral_tsum [Countable β] {f : β → α → ℝ≥0∞} (hf : ∀ i, AEMeasurable (f i) μ) :
∫⁻ a, ∑' i, f i a ∂μ = ∑' i, ∫⁻ a, f i a ∂μ := by
simp only [ENNReal.tsum_eq_iSup_sum]
rw [lintegral_iSup_directed]
· simp [lintegral_finset_sum' _ fun i _ => hf i]
· intro b
exact Finset.aemeasurable_sum _ fun i _ => hf i
· intro s t
use s ∪ t
constructor
· exact fun a => Finset.sum_le_sum_of_subset Finset.subset_union_left
· exact fun a => Finset.sum_le_sum_of_subset Finset.subset_union_right
#align measure_theory.lintegral_tsum MeasureTheory.lintegral_tsum
open Measure
theorem lintegral_iUnion₀ [Countable β] {s : β → Set α} (hm : ∀ i, NullMeasurableSet (s i) μ)
(hd : Pairwise (AEDisjoint μ on s)) (f : α → ℝ≥0∞) :
∫⁻ a in ⋃ i, s i, f a ∂μ = ∑' i, ∫⁻ a in s i, f a ∂μ := by
simp only [Measure.restrict_iUnion_ae hd hm, lintegral_sum_measure]
#align measure_theory.lintegral_Union₀ MeasureTheory.lintegral_iUnion₀
theorem lintegral_iUnion [Countable β] {s : β → Set α} (hm : ∀ i, MeasurableSet (s i))
(hd : Pairwise (Disjoint on s)) (f : α → ℝ≥0∞) :
∫⁻ a in ⋃ i, s i, f a ∂μ = ∑' i, ∫⁻ a in s i, f a ∂μ :=
lintegral_iUnion₀ (fun i => (hm i).nullMeasurableSet) hd.aedisjoint f
#align measure_theory.lintegral_Union MeasureTheory.lintegral_iUnion
theorem lintegral_biUnion₀ {t : Set β} {s : β → Set α} (ht : t.Countable)
(hm : ∀ i ∈ t, NullMeasurableSet (s i) μ) (hd : t.Pairwise (AEDisjoint μ on s)) (f : α → ℝ≥0∞) :
∫⁻ a in ⋃ i ∈ t, s i, f a ∂μ = ∑' i : t, ∫⁻ a in s i, f a ∂μ := by
haveI := ht.toEncodable
rw [biUnion_eq_iUnion, lintegral_iUnion₀ (SetCoe.forall'.1 hm) (hd.subtype _ _)]
#align measure_theory.lintegral_bUnion₀ MeasureTheory.lintegral_biUnion₀
theorem lintegral_biUnion {t : Set β} {s : β → Set α} (ht : t.Countable)
(hm : ∀ i ∈ t, MeasurableSet (s i)) (hd : t.PairwiseDisjoint s) (f : α → ℝ≥0∞) :
∫⁻ a in ⋃ i ∈ t, s i, f a ∂μ = ∑' i : t, ∫⁻ a in s i, f a ∂μ :=
lintegral_biUnion₀ ht (fun i hi => (hm i hi).nullMeasurableSet) hd.aedisjoint f
#align measure_theory.lintegral_bUnion MeasureTheory.lintegral_biUnion
theorem lintegral_biUnion_finset₀ {s : Finset β} {t : β → Set α}
(hd : Set.Pairwise (↑s) (AEDisjoint μ on t)) (hm : ∀ b ∈ s, NullMeasurableSet (t b) μ)
(f : α → ℝ≥0∞) : ∫⁻ a in ⋃ b ∈ s, t b, f a ∂μ = ∑ b ∈ s, ∫⁻ a in t b, f a ∂μ := by
simp only [← Finset.mem_coe, lintegral_biUnion₀ s.countable_toSet hm hd, ← Finset.tsum_subtype']
#align measure_theory.lintegral_bUnion_finset₀ MeasureTheory.lintegral_biUnion_finset₀
theorem lintegral_biUnion_finset {s : Finset β} {t : β → Set α} (hd : Set.PairwiseDisjoint (↑s) t)
(hm : ∀ b ∈ s, MeasurableSet (t b)) (f : α → ℝ≥0∞) :
∫⁻ a in ⋃ b ∈ s, t b, f a ∂μ = ∑ b ∈ s, ∫⁻ a in t b, f a ∂μ :=
lintegral_biUnion_finset₀ hd.aedisjoint (fun b hb => (hm b hb).nullMeasurableSet) f
#align measure_theory.lintegral_bUnion_finset MeasureTheory.lintegral_biUnion_finset
theorem lintegral_iUnion_le [Countable β] (s : β → Set α) (f : α → ℝ≥0∞) :
∫⁻ a in ⋃ i, s i, f a ∂μ ≤ ∑' i, ∫⁻ a in s i, f a ∂μ := by
rw [← lintegral_sum_measure]
exact lintegral_mono' restrict_iUnion_le le_rfl
#align measure_theory.lintegral_Union_le MeasureTheory.lintegral_iUnion_le
theorem lintegral_union {f : α → ℝ≥0∞} {A B : Set α} (hB : MeasurableSet B) (hAB : Disjoint A B) :
∫⁻ a in A ∪ B, f a ∂μ = ∫⁻ a in A, f a ∂μ + ∫⁻ a in B, f a ∂μ := by
rw [restrict_union hAB hB, lintegral_add_measure]
#align measure_theory.lintegral_union MeasureTheory.lintegral_union
theorem lintegral_union_le (f : α → ℝ≥0∞) (s t : Set α) :
∫⁻ a in s ∪ t, f a ∂μ ≤ ∫⁻ a in s, f a ∂μ + ∫⁻ a in t, f a ∂μ := by
rw [← lintegral_add_measure]
exact lintegral_mono' (restrict_union_le _ _) le_rfl
theorem lintegral_inter_add_diff {B : Set α} (f : α → ℝ≥0∞) (A : Set α) (hB : MeasurableSet B) :
∫⁻ x in A ∩ B, f x ∂μ + ∫⁻ x in A \ B, f x ∂μ = ∫⁻ x in A, f x ∂μ := by
rw [← lintegral_add_measure, restrict_inter_add_diff _ hB]
#align measure_theory.lintegral_inter_add_diff MeasureTheory.lintegral_inter_add_diff
theorem lintegral_add_compl (f : α → ℝ≥0∞) {A : Set α} (hA : MeasurableSet A) :
∫⁻ x in A, f x ∂μ + ∫⁻ x in Aᶜ, f x ∂μ = ∫⁻ x, f x ∂μ := by
rw [← lintegral_add_measure, Measure.restrict_add_restrict_compl hA]
#align measure_theory.lintegral_add_compl MeasureTheory.lintegral_add_compl
theorem lintegral_max {f g : α → ℝ≥0∞} (hf : Measurable f) (hg : Measurable g) :
∫⁻ x, max (f x) (g x) ∂μ =
∫⁻ x in { x | f x ≤ g x }, g x ∂μ + ∫⁻ x in { x | g x < f x }, f x ∂μ := by
have hm : MeasurableSet { x | f x ≤ g x } := measurableSet_le hf hg
rw [← lintegral_add_compl (fun x => max (f x) (g x)) hm]
simp only [← compl_setOf, ← not_le]
refine congr_arg₂ (· + ·) (set_lintegral_congr_fun hm ?_) (set_lintegral_congr_fun hm.compl ?_)
exacts [ae_of_all _ fun x => max_eq_right (a := f x) (b := g x),
ae_of_all _ fun x (hx : ¬ f x ≤ g x) => max_eq_left (not_le.1 hx).le]
#align measure_theory.lintegral_max MeasureTheory.lintegral_max
theorem set_lintegral_max {f g : α → ℝ≥0∞} (hf : Measurable f) (hg : Measurable g) (s : Set α) :
∫⁻ x in s, max (f x) (g x) ∂μ =
∫⁻ x in s ∩ { x | f x ≤ g x }, g x ∂μ + ∫⁻ x in s ∩ { x | g x < f x }, f x ∂μ := by
rw [lintegral_max hf hg, restrict_restrict, restrict_restrict, inter_comm s, inter_comm s]
exacts [measurableSet_lt hg hf, measurableSet_le hf hg]
#align measure_theory.set_lintegral_max MeasureTheory.set_lintegral_max
theorem lintegral_map {mβ : MeasurableSpace β} {f : β → ℝ≥0∞} {g : α → β} (hf : Measurable f)
(hg : Measurable g) : ∫⁻ a, f a ∂map g μ = ∫⁻ a, f (g a) ∂μ := by
erw [lintegral_eq_iSup_eapprox_lintegral hf, lintegral_eq_iSup_eapprox_lintegral (hf.comp hg)]
congr with n : 1
convert SimpleFunc.lintegral_map _ hg
ext1 x; simp only [eapprox_comp hf hg, coe_comp]
#align measure_theory.lintegral_map MeasureTheory.lintegral_map
theorem lintegral_map' {mβ : MeasurableSpace β} {f : β → ℝ≥0∞} {g : α → β}
(hf : AEMeasurable f (Measure.map g μ)) (hg : AEMeasurable g μ) :
∫⁻ a, f a ∂Measure.map g μ = ∫⁻ a, f (g a) ∂μ :=
calc
∫⁻ a, f a ∂Measure.map g μ = ∫⁻ a, hf.mk f a ∂Measure.map g μ :=
lintegral_congr_ae hf.ae_eq_mk
_ = ∫⁻ a, hf.mk f a ∂Measure.map (hg.mk g) μ := by
congr 1
exact Measure.map_congr hg.ae_eq_mk
_ = ∫⁻ a, hf.mk f (hg.mk g a) ∂μ := lintegral_map hf.measurable_mk hg.measurable_mk
_ = ∫⁻ a, hf.mk f (g a) ∂μ := lintegral_congr_ae <| hg.ae_eq_mk.symm.fun_comp _
_ = ∫⁻ a, f (g a) ∂μ := lintegral_congr_ae (ae_eq_comp hg hf.ae_eq_mk.symm)
#align measure_theory.lintegral_map' MeasureTheory.lintegral_map'
theorem lintegral_map_le {mβ : MeasurableSpace β} (f : β → ℝ≥0∞) {g : α → β} (hg : Measurable g) :
∫⁻ a, f a ∂Measure.map g μ ≤ ∫⁻ a, f (g a) ∂μ := by
rw [← iSup_lintegral_measurable_le_eq_lintegral, ← iSup_lintegral_measurable_le_eq_lintegral]
refine iSup₂_le fun i hi => iSup_le fun h'i => ?_
refine le_iSup₂_of_le (i ∘ g) (hi.comp hg) ?_
exact le_iSup_of_le (fun x => h'i (g x)) (le_of_eq (lintegral_map hi hg))
#align measure_theory.lintegral_map_le MeasureTheory.lintegral_map_le
theorem lintegral_comp [MeasurableSpace β] {f : β → ℝ≥0∞} {g : α → β} (hf : Measurable f)
(hg : Measurable g) : lintegral μ (f ∘ g) = ∫⁻ a, f a ∂map g μ :=
(lintegral_map hf hg).symm
#align measure_theory.lintegral_comp MeasureTheory.lintegral_comp
theorem set_lintegral_map [MeasurableSpace β] {f : β → ℝ≥0∞} {g : α → β} {s : Set β}
(hs : MeasurableSet s) (hf : Measurable f) (hg : Measurable g) :
∫⁻ y in s, f y ∂map g μ = ∫⁻ x in g ⁻¹' s, f (g x) ∂μ := by
rw [restrict_map hg hs, lintegral_map hf hg]
#align measure_theory.set_lintegral_map MeasureTheory.set_lintegral_map
theorem lintegral_indicator_const_comp {mβ : MeasurableSpace β} {f : α → β} {s : Set β}
(hf : Measurable f) (hs : MeasurableSet s) (c : ℝ≥0∞) :
∫⁻ a, s.indicator (fun _ => c) (f a) ∂μ = c * μ (f ⁻¹' s) := by
erw [lintegral_comp (measurable_const.indicator hs) hf, lintegral_indicator_const hs,
Measure.map_apply hf hs]
#align measure_theory.lintegral_indicator_const_comp MeasureTheory.lintegral_indicator_const_comp
theorem _root_.MeasurableEmbedding.lintegral_map [MeasurableSpace β] {g : α → β}
(hg : MeasurableEmbedding g) (f : β → ℝ≥0∞) : ∫⁻ a, f a ∂map g μ = ∫⁻ a, f (g a) ∂μ := by
rw [lintegral, lintegral]
refine le_antisymm (iSup₂_le fun f₀ hf₀ => ?_) (iSup₂_le fun f₀ hf₀ => ?_)
· rw [SimpleFunc.lintegral_map _ hg.measurable]
have : (f₀.comp g hg.measurable : α → ℝ≥0∞) ≤ f ∘ g := fun x => hf₀ (g x)
exact le_iSup_of_le (comp f₀ g hg.measurable) (by exact le_iSup (α := ℝ≥0∞) _ this)
· rw [← f₀.extend_comp_eq hg (const _ 0), ← SimpleFunc.lintegral_map, ←
SimpleFunc.lintegral_eq_lintegral, ← lintegral]
refine lintegral_mono_ae (hg.ae_map_iff.2 <| eventually_of_forall fun x => ?_)
exact (extend_apply _ _ _ _).trans_le (hf₀ _)
#align measurable_embedding.lintegral_map MeasurableEmbedding.lintegral_map
theorem lintegral_map_equiv [MeasurableSpace β] (f : β → ℝ≥0∞) (g : α ≃ᵐ β) :
∫⁻ a, f a ∂map g μ = ∫⁻ a, f (g a) ∂μ :=
g.measurableEmbedding.lintegral_map f
#align measure_theory.lintegral_map_equiv MeasureTheory.lintegral_map_equiv
protected theorem MeasurePreserving.lintegral_map_equiv [MeasurableSpace β] {ν : Measure β}
(f : β → ℝ≥0∞) (g : α ≃ᵐ β) (hg : MeasurePreserving g μ ν) :
∫⁻ a, f a ∂ν = ∫⁻ a, f (g a) ∂μ := by
rw [← MeasureTheory.lintegral_map_equiv f g, hg.map_eq]
theorem MeasurePreserving.lintegral_comp {mb : MeasurableSpace β} {ν : Measure β} {g : α → β}
(hg : MeasurePreserving g μ ν) {f : β → ℝ≥0∞} (hf : Measurable f) :
∫⁻ a, f (g a) ∂μ = ∫⁻ b, f b ∂ν := by rw [← hg.map_eq, lintegral_map hf hg.measurable]
#align measure_theory.measure_preserving.lintegral_comp MeasureTheory.MeasurePreserving.lintegral_comp
theorem MeasurePreserving.lintegral_comp_emb {mb : MeasurableSpace β} {ν : Measure β} {g : α → β}
(hg : MeasurePreserving g μ ν) (hge : MeasurableEmbedding g) (f : β → ℝ≥0∞) :
∫⁻ a, f (g a) ∂μ = ∫⁻ b, f b ∂ν := by rw [← hg.map_eq, hge.lintegral_map]
#align measure_theory.measure_preserving.lintegral_comp_emb MeasureTheory.MeasurePreserving.lintegral_comp_emb
theorem MeasurePreserving.set_lintegral_comp_preimage {mb : MeasurableSpace β} {ν : Measure β}
{g : α → β} (hg : MeasurePreserving g μ ν) {s : Set β} (hs : MeasurableSet s) {f : β → ℝ≥0∞}
(hf : Measurable f) : ∫⁻ a in g ⁻¹' s, f (g a) ∂μ = ∫⁻ b in s, f b ∂ν := by
rw [← hg.map_eq, set_lintegral_map hs hf hg.measurable]
#align measure_theory.measure_preserving.set_lintegral_comp_preimage MeasureTheory.MeasurePreserving.set_lintegral_comp_preimage
theorem MeasurePreserving.set_lintegral_comp_preimage_emb {mb : MeasurableSpace β} {ν : Measure β}
{g : α → β} (hg : MeasurePreserving g μ ν) (hge : MeasurableEmbedding g) (f : β → ℝ≥0∞)
(s : Set β) : ∫⁻ a in g ⁻¹' s, f (g a) ∂μ = ∫⁻ b in s, f b ∂ν := by
rw [← hg.map_eq, hge.restrict_map, hge.lintegral_map]
#align measure_theory.measure_preserving.set_lintegral_comp_preimage_emb MeasureTheory.MeasurePreserving.set_lintegral_comp_preimage_emb
theorem MeasurePreserving.set_lintegral_comp_emb {mb : MeasurableSpace β} {ν : Measure β}
{g : α → β} (hg : MeasurePreserving g μ ν) (hge : MeasurableEmbedding g) (f : β → ℝ≥0∞)
(s : Set α) : ∫⁻ a in s, f (g a) ∂μ = ∫⁻ b in g '' s, f b ∂ν := by
rw [← hg.set_lintegral_comp_preimage_emb hge, preimage_image_eq _ hge.injective]
#align measure_theory.measure_preserving.set_lintegral_comp_emb MeasureTheory.MeasurePreserving.set_lintegral_comp_emb
theorem lintegral_subtype_comap {s : Set α} (hs : MeasurableSet s) (f : α → ℝ≥0∞) :
∫⁻ x : s, f x ∂(μ.comap (↑)) = ∫⁻ x in s, f x ∂μ := by
rw [← (MeasurableEmbedding.subtype_coe hs).lintegral_map, map_comap_subtype_coe hs]
theorem set_lintegral_subtype {s : Set α} (hs : MeasurableSet s) (t : Set s) (f : α → ℝ≥0∞) :
∫⁻ x in t, f x ∂(μ.comap (↑)) = ∫⁻ x in (↑) '' t, f x ∂μ := by
rw [(MeasurableEmbedding.subtype_coe hs).restrict_comap, lintegral_subtype_comap hs,
restrict_restrict hs, inter_eq_right.2 (Subtype.coe_image_subset _ _)]
section DiracAndCount
variable [MeasurableSpace α]
theorem lintegral_dirac' (a : α) {f : α → ℝ≥0∞} (hf : Measurable f) : ∫⁻ a, f a ∂dirac a = f a := by
simp [lintegral_congr_ae (ae_eq_dirac' hf)]
#align measure_theory.lintegral_dirac' MeasureTheory.lintegral_dirac'
theorem lintegral_dirac [MeasurableSingletonClass α] (a : α) (f : α → ℝ≥0∞) :
∫⁻ a, f a ∂dirac a = f a := by simp [lintegral_congr_ae (ae_eq_dirac f)]
#align measure_theory.lintegral_dirac MeasureTheory.lintegral_dirac
theorem set_lintegral_dirac' {a : α} {f : α → ℝ≥0∞} (hf : Measurable f) {s : Set α}
(hs : MeasurableSet s) [Decidable (a ∈ s)] :
∫⁻ x in s, f x ∂Measure.dirac a = if a ∈ s then f a else 0 := by
rw [restrict_dirac' hs]
split_ifs
· exact lintegral_dirac' _ hf
· exact lintegral_zero_measure _
#align measure_theory.set_lintegral_dirac' MeasureTheory.set_lintegral_dirac'
theorem set_lintegral_dirac {a : α} (f : α → ℝ≥0∞) (s : Set α) [MeasurableSingletonClass α]
[Decidable (a ∈ s)] : ∫⁻ x in s, f x ∂Measure.dirac a = if a ∈ s then f a else 0 := by
rw [restrict_dirac]
split_ifs
· exact lintegral_dirac _ _
· exact lintegral_zero_measure _
#align measure_theory.set_lintegral_dirac MeasureTheory.set_lintegral_dirac
theorem lintegral_count' {f : α → ℝ≥0∞} (hf : Measurable f) : ∫⁻ a, f a ∂count = ∑' a, f a := by
rw [count, lintegral_sum_measure]
congr
exact funext fun a => lintegral_dirac' a hf
#align measure_theory.lintegral_count' MeasureTheory.lintegral_count'
theorem lintegral_count [MeasurableSingletonClass α] (f : α → ℝ≥0∞) :
∫⁻ a, f a ∂count = ∑' a, f a := by
rw [count, lintegral_sum_measure]
congr
exact funext fun a => lintegral_dirac a f
#align measure_theory.lintegral_count MeasureTheory.lintegral_count
| Mathlib/MeasureTheory/Integral/Lebesgue.lean | 1,541 | 1,542 | theorem _root_.ENNReal.tsum_const_eq [MeasurableSingletonClass α] (c : ℝ≥0∞) :
∑' _ : α, c = c * Measure.count (univ : Set α) := by | rw [← lintegral_count, lintegral_const]
|
import Mathlib.LinearAlgebra.ExteriorAlgebra.Basic
import Mathlib.LinearAlgebra.CliffordAlgebra.Fold
import Mathlib.LinearAlgebra.CliffordAlgebra.Conjugation
import Mathlib.LinearAlgebra.Dual
#align_import linear_algebra.clifford_algebra.contraction from "leanprover-community/mathlib"@"70fd9563a21e7b963887c9360bd29b2393e6225a"
open LinearMap (BilinForm)
universe u1 u2 u3
variable {R : Type u1} [CommRing R]
variable {M : Type u2} [AddCommGroup M] [Module R M]
variable (Q : QuadraticForm R M)
namespace CliffordAlgebra
section contractLeft
variable (d d' : Module.Dual R M)
@[simps!]
def contractLeftAux (d : Module.Dual R M) :
M →ₗ[R] CliffordAlgebra Q × CliffordAlgebra Q →ₗ[R] CliffordAlgebra Q :=
haveI v_mul := (Algebra.lmul R (CliffordAlgebra Q)).toLinearMap ∘ₗ ι Q
d.smulRight (LinearMap.fst _ (CliffordAlgebra Q) (CliffordAlgebra Q)) -
v_mul.compl₂ (LinearMap.snd _ (CliffordAlgebra Q) _)
#align clifford_algebra.contract_left_aux CliffordAlgebra.contractLeftAux
theorem contractLeftAux_contractLeftAux (v : M) (x : CliffordAlgebra Q) (fx : CliffordAlgebra Q) :
contractLeftAux Q d v (ι Q v * x, contractLeftAux Q d v (x, fx)) = Q v • fx := by
simp only [contractLeftAux_apply_apply]
rw [mul_sub, ← mul_assoc, ι_sq_scalar, ← Algebra.smul_def, ← sub_add, mul_smul_comm, sub_self,
zero_add]
#align clifford_algebra.contract_left_aux_contract_left_aux CliffordAlgebra.contractLeftAux_contractLeftAux
variable {Q}
def contractLeft : Module.Dual R M →ₗ[R] CliffordAlgebra Q →ₗ[R] CliffordAlgebra Q where
toFun d := foldr' Q (contractLeftAux Q d) (contractLeftAux_contractLeftAux Q d) 0
map_add' d₁ d₂ :=
LinearMap.ext fun x => by
dsimp only
rw [LinearMap.add_apply]
induction' x using CliffordAlgebra.left_induction with r x y hx hy m x hx
· simp_rw [foldr'_algebraMap, smul_zero, zero_add]
· rw [map_add, map_add, map_add, add_add_add_comm, hx, hy]
· rw [foldr'_ι_mul, foldr'_ι_mul, foldr'_ι_mul, hx]
dsimp only [contractLeftAux_apply_apply]
rw [sub_add_sub_comm, mul_add, LinearMap.add_apply, add_smul]
map_smul' c d :=
LinearMap.ext fun x => by
dsimp only
rw [LinearMap.smul_apply, RingHom.id_apply]
induction' x using CliffordAlgebra.left_induction with r x y hx hy m x hx
· simp_rw [foldr'_algebraMap, smul_zero]
· rw [map_add, map_add, smul_add, hx, hy]
· rw [foldr'_ι_mul, foldr'_ι_mul, hx]
dsimp only [contractLeftAux_apply_apply]
rw [LinearMap.smul_apply, smul_assoc, mul_smul_comm, smul_sub]
#align clifford_algebra.contract_left CliffordAlgebra.contractLeft
def contractRight : CliffordAlgebra Q →ₗ[R] Module.Dual R M →ₗ[R] CliffordAlgebra Q :=
LinearMap.flip (LinearMap.compl₂ (LinearMap.compr₂ contractLeft reverse) reverse)
#align clifford_algebra.contract_right CliffordAlgebra.contractRight
theorem contractRight_eq (x : CliffordAlgebra Q) :
contractRight (Q := Q) x d = reverse (contractLeft (R := R) (M := M) d <| reverse x) :=
rfl
#align clifford_algebra.contract_right_eq CliffordAlgebra.contractRight_eq
local infixl:70 "⌋" => contractLeft (R := R) (M := M)
local infixl:70 "⌊" => contractRight (R := R) (M := M) (Q := Q)
-- Porting note: Lean needs to be reminded of this instance otherwise the statement of the
-- next result times out
instance : SMul R (CliffordAlgebra Q) := inferInstance
theorem contractLeft_ι_mul (a : M) (b : CliffordAlgebra Q) :
d⌋(ι Q a * b) = d a • b - ι Q a * (d⌋b) := by
-- Porting note: Lean cannot figure out anymore the third argument
refine foldr'_ι_mul _ _ ?_ _ _ _
exact fun m x fx ↦ contractLeftAux_contractLeftAux Q d m x fx
#align clifford_algebra.contract_left_ι_mul CliffordAlgebra.contractLeft_ι_mul
theorem contractRight_mul_ι (a : M) (b : CliffordAlgebra Q) :
b * ι Q a⌊d = d a • b - b⌊d * ι Q a := by
rw [contractRight_eq, reverse.map_mul, reverse_ι, contractLeft_ι_mul, map_sub, map_smul,
reverse_reverse, reverse.map_mul, reverse_ι, contractRight_eq]
#align clifford_algebra.contract_right_mul_ι CliffordAlgebra.contractRight_mul_ι
theorem contractLeft_algebraMap_mul (r : R) (b : CliffordAlgebra Q) :
d⌋(algebraMap _ _ r * b) = algebraMap _ _ r * (d⌋b) := by
rw [← Algebra.smul_def, map_smul, Algebra.smul_def]
#align clifford_algebra.contract_left_algebra_map_mul CliffordAlgebra.contractLeft_algebraMap_mul
theorem contractLeft_mul_algebraMap (a : CliffordAlgebra Q) (r : R) :
d⌋(a * algebraMap _ _ r) = d⌋a * algebraMap _ _ r := by
rw [← Algebra.commutes, contractLeft_algebraMap_mul, Algebra.commutes]
#align clifford_algebra.contract_left_mul_algebra_map CliffordAlgebra.contractLeft_mul_algebraMap
| Mathlib/LinearAlgebra/CliffordAlgebra/Contraction.lean | 154 | 156 | theorem contractRight_algebraMap_mul (r : R) (b : CliffordAlgebra Q) :
algebraMap _ _ r * b⌊d = algebraMap _ _ r * (b⌊d) := by |
rw [← Algebra.smul_def, LinearMap.map_smul₂, Algebra.smul_def]
|
import Mathlib.Topology.Algebra.Module.WeakDual
import Mathlib.MeasureTheory.Integral.BoundedContinuousFunction
import Mathlib.MeasureTheory.Measure.HasOuterApproxClosed
#align_import measure_theory.measure.finite_measure from "leanprover-community/mathlib"@"f2ce6086713c78a7f880485f7917ea547a215982"
noncomputable section
open MeasureTheory
open Set
open Filter
open BoundedContinuousFunction
open scoped Topology ENNReal NNReal BoundedContinuousFunction
namespace MeasureTheory
namespace FiniteMeasure
section FiniteMeasure
variable {Ω : Type*} [MeasurableSpace Ω]
def _root_.MeasureTheory.FiniteMeasure (Ω : Type*) [MeasurableSpace Ω] : Type _ :=
{ μ : Measure Ω // IsFiniteMeasure μ }
#align measure_theory.finite_measure MeasureTheory.FiniteMeasure
-- Porting note: as with other subtype synonyms (e.g., `ℝ≥0`, we need a new function for the
-- coercion instead of relying on `Subtype.val`.
@[coe]
def toMeasure : FiniteMeasure Ω → Measure Ω := Subtype.val
instance instCoe : Coe (FiniteMeasure Ω) (MeasureTheory.Measure Ω) where
coe := toMeasure
instance isFiniteMeasure (μ : FiniteMeasure Ω) : IsFiniteMeasure (μ : Measure Ω) :=
μ.prop
#align measure_theory.finite_measure.is_finite_measure MeasureTheory.FiniteMeasure.isFiniteMeasure
@[simp]
theorem val_eq_toMeasure (ν : FiniteMeasure Ω) : ν.val = (ν : Measure Ω) :=
rfl
#align measure_theory.finite_measure.val_eq_to_measure MeasureTheory.FiniteMeasure.val_eq_toMeasure
theorem toMeasure_injective : Function.Injective ((↑) : FiniteMeasure Ω → Measure Ω) :=
Subtype.coe_injective
#align measure_theory.finite_measure.coe_injective MeasureTheory.FiniteMeasure.toMeasure_injective
instance instFunLike : FunLike (FiniteMeasure Ω) (Set Ω) ℝ≥0 where
coe μ s := ((μ : Measure Ω) s).toNNReal
coe_injective' μ ν h := toMeasure_injective $ Measure.ext fun s _ ↦ by
simpa [ENNReal.toNNReal_eq_toNNReal_iff, measure_ne_top] using congr_fun h s
lemma coeFn_def (μ : FiniteMeasure Ω) : μ = fun s ↦ ((μ : Measure Ω) s).toNNReal := rfl
#align measure_theory.finite_measure.coe_fn_eq_to_nnreal_coe_fn_to_measure MeasureTheory.FiniteMeasure.coeFn_def
lemma coeFn_mk (μ : Measure Ω) (hμ) :
DFunLike.coe (F := FiniteMeasure Ω) ⟨μ, hμ⟩ = fun s ↦ (μ s).toNNReal := rfl
@[simp, norm_cast]
lemma mk_apply (μ : Measure Ω) (hμ) (s : Set Ω) :
DFunLike.coe (F := FiniteMeasure Ω) ⟨μ, hμ⟩ s = (μ s).toNNReal := rfl
@[simp]
theorem ennreal_coeFn_eq_coeFn_toMeasure (ν : FiniteMeasure Ω) (s : Set Ω) :
(ν s : ℝ≥0∞) = (ν : Measure Ω) s :=
ENNReal.coe_toNNReal (measure_lt_top (↑ν) s).ne
#align measure_theory.finite_measure.ennreal_coe_fn_eq_coe_fn_to_measure MeasureTheory.FiniteMeasure.ennreal_coeFn_eq_coeFn_toMeasure
theorem apply_mono (μ : FiniteMeasure Ω) {s₁ s₂ : Set Ω} (h : s₁ ⊆ s₂) : μ s₁ ≤ μ s₂ := by
change ((μ : Measure Ω) s₁).toNNReal ≤ ((μ : Measure Ω) s₂).toNNReal
have key : (μ : Measure Ω) s₁ ≤ (μ : Measure Ω) s₂ := (μ : Measure Ω).mono h
apply (ENNReal.toNNReal_le_toNNReal (measure_ne_top _ s₁) (measure_ne_top _ s₂)).mpr key
#align measure_theory.finite_measure.apply_mono MeasureTheory.FiniteMeasure.apply_mono
def mass (μ : FiniteMeasure Ω) : ℝ≥0 :=
μ univ
#align measure_theory.finite_measure.mass MeasureTheory.FiniteMeasure.mass
@[simp] theorem apply_le_mass (μ : FiniteMeasure Ω) (s : Set Ω) : μ s ≤ μ.mass := by
simpa using apply_mono μ (subset_univ s)
@[simp]
theorem ennreal_mass {μ : FiniteMeasure Ω} : (μ.mass : ℝ≥0∞) = (μ : Measure Ω) univ :=
ennreal_coeFn_eq_coeFn_toMeasure μ Set.univ
#align measure_theory.finite_measure.ennreal_mass MeasureTheory.FiniteMeasure.ennreal_mass
instance instZero : Zero (FiniteMeasure Ω) where zero := ⟨0, MeasureTheory.isFiniteMeasureZero⟩
#align measure_theory.finite_measure.has_zero MeasureTheory.FiniteMeasure.instZero
@[simp, norm_cast] lemma coeFn_zero : ⇑(0 : FiniteMeasure Ω) = 0 := rfl
#align measure_theory.finite_measure.coe_fn_zero MeasureTheory.FiniteMeasure.coeFn_zero
@[simp]
theorem zero_mass : (0 : FiniteMeasure Ω).mass = 0 :=
rfl
#align measure_theory.finite_measure.zero.mass MeasureTheory.FiniteMeasure.zero_mass
@[simp]
theorem mass_zero_iff (μ : FiniteMeasure Ω) : μ.mass = 0 ↔ μ = 0 := by
refine ⟨fun μ_mass => ?_, fun hμ => by simp only [hμ, zero_mass]⟩
apply toMeasure_injective
apply Measure.measure_univ_eq_zero.mp
rwa [← ennreal_mass, ENNReal.coe_eq_zero]
#align measure_theory.finite_measure.mass_zero_iff MeasureTheory.FiniteMeasure.mass_zero_iff
theorem mass_nonzero_iff (μ : FiniteMeasure Ω) : μ.mass ≠ 0 ↔ μ ≠ 0 := by
rw [not_iff_not]
exact FiniteMeasure.mass_zero_iff μ
#align measure_theory.finite_measure.mass_nonzero_iff MeasureTheory.FiniteMeasure.mass_nonzero_iff
@[ext]
theorem eq_of_forall_toMeasure_apply_eq (μ ν : FiniteMeasure Ω)
(h : ∀ s : Set Ω, MeasurableSet s → (μ : Measure Ω) s = (ν : Measure Ω) s) : μ = ν := by
apply Subtype.ext
ext1 s s_mble
exact h s s_mble
#align measure_theory.finite_measure.eq_of_forall_measure_apply_eq MeasureTheory.FiniteMeasure.eq_of_forall_toMeasure_apply_eq
theorem eq_of_forall_apply_eq (μ ν : FiniteMeasure Ω)
(h : ∀ s : Set Ω, MeasurableSet s → μ s = ν s) : μ = ν := by
ext1 s s_mble
simpa [ennreal_coeFn_eq_coeFn_toMeasure] using congr_arg ((↑) : ℝ≥0 → ℝ≥0∞) (h s s_mble)
#align measure_theory.finite_measure.eq_of_forall_apply_eq MeasureTheory.FiniteMeasure.eq_of_forall_apply_eq
instance instInhabited : Inhabited (FiniteMeasure Ω) :=
⟨0⟩
instance instAdd : Add (FiniteMeasure Ω) where add μ ν := ⟨μ + ν, MeasureTheory.isFiniteMeasureAdd⟩
variable {R : Type*} [SMul R ℝ≥0] [SMul R ℝ≥0∞] [IsScalarTower R ℝ≥0 ℝ≥0∞]
[IsScalarTower R ℝ≥0∞ ℝ≥0∞]
instance instSMul : SMul R (FiniteMeasure Ω) where
smul (c : R) μ := ⟨c • (μ : Measure Ω), MeasureTheory.isFiniteMeasureSMulOfNNRealTower⟩
@[simp, norm_cast]
theorem toMeasure_zero : ((↑) : FiniteMeasure Ω → Measure Ω) 0 = 0 :=
rfl
#align measure_theory.finite_measure.coe_zero MeasureTheory.FiniteMeasure.toMeasure_zero
-- Porting note: with `simp` here the `coeFn` lemmas below fall prey to `simpNF`: the LHS simplifies
@[norm_cast]
theorem toMeasure_add (μ ν : FiniteMeasure Ω) : ↑(μ + ν) = (↑μ + ↑ν : Measure Ω) :=
rfl
#align measure_theory.finite_measure.coe_add MeasureTheory.FiniteMeasure.toMeasure_add
@[simp, norm_cast]
theorem toMeasure_smul (c : R) (μ : FiniteMeasure Ω) : ↑(c • μ) = c • (μ : Measure Ω) :=
rfl
#align measure_theory.finite_measure.coe_smul MeasureTheory.FiniteMeasure.toMeasure_smul
@[simp, norm_cast]
theorem coeFn_add (μ ν : FiniteMeasure Ω) : (⇑(μ + ν) : Set Ω → ℝ≥0) = (⇑μ + ⇑ν : Set Ω → ℝ≥0) := by
funext
simp only [Pi.add_apply, ← ENNReal.coe_inj, ne_eq, ennreal_coeFn_eq_coeFn_toMeasure,
ENNReal.coe_add]
norm_cast
#align measure_theory.finite_measure.coe_fn_add MeasureTheory.FiniteMeasure.coeFn_add
@[simp, norm_cast]
theorem coeFn_smul [IsScalarTower R ℝ≥0 ℝ≥0] (c : R) (μ : FiniteMeasure Ω) :
(⇑(c • μ) : Set Ω → ℝ≥0) = c • (⇑μ : Set Ω → ℝ≥0) := by
funext; simp [← ENNReal.coe_inj, ENNReal.coe_smul]
#align measure_theory.finite_measure.coe_fn_smul MeasureTheory.FiniteMeasure.coeFn_smul
instance instAddCommMonoid : AddCommMonoid (FiniteMeasure Ω) :=
toMeasure_injective.addCommMonoid (↑) toMeasure_zero toMeasure_add fun _ _ => toMeasure_smul _ _
@[simps]
def toMeasureAddMonoidHom : FiniteMeasure Ω →+ Measure Ω where
toFun := (↑)
map_zero' := toMeasure_zero
map_add' := toMeasure_add
#align measure_theory.finite_measure.coe_add_monoid_hom MeasureTheory.FiniteMeasure.toMeasureAddMonoidHom
instance {Ω : Type*} [MeasurableSpace Ω] : Module ℝ≥0 (FiniteMeasure Ω) :=
Function.Injective.module _ toMeasureAddMonoidHom toMeasure_injective toMeasure_smul
@[simp]
theorem smul_apply [IsScalarTower R ℝ≥0 ℝ≥0] (c : R) (μ : FiniteMeasure Ω) (s : Set Ω) :
(c • μ) s = c • μ s := by
rw [coeFn_smul, Pi.smul_apply]
#align measure_theory.finite_measure.coe_fn_smul_apply MeasureTheory.FiniteMeasure.smul_apply
def restrict (μ : FiniteMeasure Ω) (A : Set Ω) : FiniteMeasure Ω where
val := (μ : Measure Ω).restrict A
property := MeasureTheory.isFiniteMeasureRestrict (μ : Measure Ω) A
#align measure_theory.finite_measure.restrict MeasureTheory.FiniteMeasure.restrict
theorem restrict_measure_eq (μ : FiniteMeasure Ω) (A : Set Ω) :
(μ.restrict A : Measure Ω) = (μ : Measure Ω).restrict A :=
rfl
#align measure_theory.finite_measure.restrict_measure_eq MeasureTheory.FiniteMeasure.restrict_measure_eq
theorem restrict_apply_measure (μ : FiniteMeasure Ω) (A : Set Ω) {s : Set Ω}
(s_mble : MeasurableSet s) : (μ.restrict A : Measure Ω) s = (μ : Measure Ω) (s ∩ A) :=
Measure.restrict_apply s_mble
#align measure_theory.finite_measure.restrict_apply_measure MeasureTheory.FiniteMeasure.restrict_apply_measure
theorem restrict_apply (μ : FiniteMeasure Ω) (A : Set Ω) {s : Set Ω} (s_mble : MeasurableSet s) :
(μ.restrict A) s = μ (s ∩ A) := by
apply congr_arg ENNReal.toNNReal
exact Measure.restrict_apply s_mble
#align measure_theory.finite_measure.restrict_apply MeasureTheory.FiniteMeasure.restrict_apply
theorem restrict_mass (μ : FiniteMeasure Ω) (A : Set Ω) : (μ.restrict A).mass = μ A := by
simp only [mass, restrict_apply μ A MeasurableSet.univ, univ_inter]
#align measure_theory.finite_measure.restrict_mass MeasureTheory.FiniteMeasure.restrict_mass
theorem restrict_eq_zero_iff (μ : FiniteMeasure Ω) (A : Set Ω) : μ.restrict A = 0 ↔ μ A = 0 := by
rw [← mass_zero_iff, restrict_mass]
#align measure_theory.finite_measure.restrict_eq_zero_iff MeasureTheory.FiniteMeasure.restrict_eq_zero_iff
theorem restrict_nonzero_iff (μ : FiniteMeasure Ω) (A : Set Ω) : μ.restrict A ≠ 0 ↔ μ A ≠ 0 := by
rw [← mass_nonzero_iff, restrict_mass]
#align measure_theory.finite_measure.restrict_nonzero_iff MeasureTheory.FiniteMeasure.restrict_nonzero_iff
variable [TopologicalSpace Ω]
theorem ext_of_forall_lintegral_eq [HasOuterApproxClosed Ω] [BorelSpace Ω]
{μ ν : FiniteMeasure Ω} (h : ∀ (f : Ω →ᵇ ℝ≥0), ∫⁻ x, f x ∂μ = ∫⁻ x, f x ∂ν) :
μ = ν := by
apply Subtype.ext
change (μ : Measure Ω) = (ν : Measure Ω)
exact ext_of_forall_lintegral_eq_of_IsFiniteMeasure h
def testAgainstNN (μ : FiniteMeasure Ω) (f : Ω →ᵇ ℝ≥0) : ℝ≥0 :=
(∫⁻ ω, f ω ∂(μ : Measure Ω)).toNNReal
#align measure_theory.finite_measure.test_against_nn MeasureTheory.FiniteMeasure.testAgainstNN
@[simp]
theorem testAgainstNN_coe_eq {μ : FiniteMeasure Ω} {f : Ω →ᵇ ℝ≥0} :
(μ.testAgainstNN f : ℝ≥0∞) = ∫⁻ ω, f ω ∂(μ : Measure Ω) :=
ENNReal.coe_toNNReal (f.lintegral_lt_top_of_nnreal _).ne
#align measure_theory.finite_measure.test_against_nn_coe_eq MeasureTheory.FiniteMeasure.testAgainstNN_coe_eq
| Mathlib/MeasureTheory/Measure/FiniteMeasure.lean | 345 | 347 | theorem testAgainstNN_const (μ : FiniteMeasure Ω) (c : ℝ≥0) :
μ.testAgainstNN (BoundedContinuousFunction.const Ω c) = c * μ.mass := by |
simp [← ENNReal.coe_inj]
|
import Mathlib.Data.Set.Subsingleton
import Mathlib.Order.WithBot
#align_import data.set.image from "leanprover-community/mathlib"@"001ffdc42920050657fd45bd2b8bfbec8eaaeb29"
universe u v
open Function Set
namespace Set
variable {α β γ : Type*} {ι ι' : Sort*}
section Image
variable {f : α → β} {s t : Set α}
-- Porting note: `Set.image` is already defined in `Init.Set`
#align set.image Set.image
@[deprecated mem_image (since := "2024-03-23")]
theorem mem_image_iff_bex {f : α → β} {s : Set α} {y : β} :
y ∈ f '' s ↔ ∃ (x : _) (_ : x ∈ s), f x = y :=
bex_def.symm
#align set.mem_image_iff_bex Set.mem_image_iff_bex
theorem image_eta (f : α → β) : f '' s = (fun x => f x) '' s :=
rfl
#align set.image_eta Set.image_eta
theorem _root_.Function.Injective.mem_set_image {f : α → β} (hf : Injective f) {s : Set α} {a : α} :
f a ∈ f '' s ↔ a ∈ s :=
⟨fun ⟨_, hb, Eq⟩ => hf Eq ▸ hb, mem_image_of_mem f⟩
#align function.injective.mem_set_image Function.Injective.mem_set_image
theorem forall_mem_image {f : α → β} {s : Set α} {p : β → Prop} :
(∀ y ∈ f '' s, p y) ↔ ∀ ⦃x⦄, x ∈ s → p (f x) := by simp
#align set.ball_image_iff Set.forall_mem_image
theorem exists_mem_image {f : α → β} {s : Set α} {p : β → Prop} :
(∃ y ∈ f '' s, p y) ↔ ∃ x ∈ s, p (f x) := by simp
#align set.bex_image_iff Set.exists_mem_image
@[deprecated (since := "2024-02-21")] alias ball_image_iff := forall_mem_image
@[deprecated (since := "2024-02-21")] alias bex_image_iff := exists_mem_image
@[deprecated (since := "2024-02-21")] alias ⟨_, ball_image_of_ball⟩ := forall_mem_image
#align set.ball_image_of_ball Set.ball_image_of_ball
@[deprecated forall_mem_image (since := "2024-02-21")]
theorem mem_image_elim {f : α → β} {s : Set α} {C : β → Prop} (h : ∀ x : α, x ∈ s → C (f x)) :
∀ {y : β}, y ∈ f '' s → C y := forall_mem_image.2 h _
#align set.mem_image_elim Set.mem_image_elim
@[deprecated forall_mem_image (since := "2024-02-21")]
theorem mem_image_elim_on {f : α → β} {s : Set α} {C : β → Prop} {y : β} (h_y : y ∈ f '' s)
(h : ∀ x : α, x ∈ s → C (f x)) : C y := forall_mem_image.2 h _ h_y
#align set.mem_image_elim_on Set.mem_image_elim_on
-- Porting note: used to be `safe`
@[congr]
theorem image_congr {f g : α → β} {s : Set α} (h : ∀ a ∈ s, f a = g a) : f '' s = g '' s := by
ext x
exact exists_congr fun a ↦ and_congr_right fun ha ↦ by rw [h a ha]
#align set.image_congr Set.image_congr
theorem image_congr' {f g : α → β} {s : Set α} (h : ∀ x : α, f x = g x) : f '' s = g '' s :=
image_congr fun x _ => h x
#align set.image_congr' Set.image_congr'
@[gcongr]
lemma image_mono (h : s ⊆ t) : f '' s ⊆ f '' t := by
rintro - ⟨a, ha, rfl⟩; exact mem_image_of_mem f (h ha)
theorem image_comp (f : β → γ) (g : α → β) (a : Set α) : f ∘ g '' a = f '' (g '' a) := by aesop
#align set.image_comp Set.image_comp
theorem image_comp_eq {g : β → γ} : image (g ∘ f) = image g ∘ image f := by ext; simp
theorem image_image (g : β → γ) (f : α → β) (s : Set α) : g '' (f '' s) = (fun x => g (f x)) '' s :=
(image_comp g f s).symm
#align set.image_image Set.image_image
| Mathlib/Data/Set/Image.lean | 273 | 275 | theorem image_comm {β'} {f : β → γ} {g : α → β} {f' : α → β'} {g' : β' → γ}
(h_comm : ∀ a, f (g a) = g' (f' a)) : (s.image g).image f = (s.image f').image g' := by |
simp_rw [image_image, h_comm]
|
import Mathlib.Logic.Function.Iterate
import Mathlib.Topology.EMetricSpace.Basic
import Mathlib.Tactic.GCongr
#align_import topology.metric_space.lipschitz from "leanprover-community/mathlib"@"f2ce6086713c78a7f880485f7917ea547a215982"
universe u v w x
open Filter Function Set Topology NNReal ENNReal Bornology
variable {α : Type u} {β : Type v} {γ : Type w} {ι : Type x}
def LipschitzWith [PseudoEMetricSpace α] [PseudoEMetricSpace β] (K : ℝ≥0) (f : α → β) :=
∀ x y, edist (f x) (f y) ≤ K * edist x y
#align lipschitz_with LipschitzWith
def LipschitzOnWith [PseudoEMetricSpace α] [PseudoEMetricSpace β] (K : ℝ≥0) (f : α → β)
(s : Set α) :=
∀ ⦃x⦄, x ∈ s → ∀ ⦃y⦄, y ∈ s → edist (f x) (f y) ≤ K * edist x y
#align lipschitz_on_with LipschitzOnWith
def LocallyLipschitz [PseudoEMetricSpace α] [PseudoEMetricSpace β] (f : α → β) : Prop :=
∀ x : α, ∃ K, ∃ t ∈ 𝓝 x, LipschitzOnWith K f t
@[simp]
theorem lipschitzOnWith_empty [PseudoEMetricSpace α] [PseudoEMetricSpace β] (K : ℝ≥0) (f : α → β) :
LipschitzOnWith K f ∅ := fun _ => False.elim
#align lipschitz_on_with_empty lipschitzOnWith_empty
theorem LipschitzOnWith.mono [PseudoEMetricSpace α] [PseudoEMetricSpace β] {K : ℝ≥0} {s t : Set α}
{f : α → β} (hf : LipschitzOnWith K f t) (h : s ⊆ t) : LipschitzOnWith K f s :=
fun _x x_in _y y_in => hf (h x_in) (h y_in)
#align lipschitz_on_with.mono LipschitzOnWith.mono
@[simp]
theorem lipschitzOn_univ [PseudoEMetricSpace α] [PseudoEMetricSpace β] {K : ℝ≥0} {f : α → β} :
LipschitzOnWith K f univ ↔ LipschitzWith K f := by simp [LipschitzOnWith, LipschitzWith]
#align lipschitz_on_univ lipschitzOn_univ
theorem lipschitzOnWith_iff_restrict [PseudoEMetricSpace α] [PseudoEMetricSpace β] {K : ℝ≥0}
{f : α → β} {s : Set α} : LipschitzOnWith K f s ↔ LipschitzWith K (s.restrict f) := by
simp only [LipschitzOnWith, LipschitzWith, SetCoe.forall', restrict, Subtype.edist_eq]
#align lipschitz_on_with_iff_restrict lipschitzOnWith_iff_restrict
alias ⟨LipschitzOnWith.to_restrict, _⟩ := lipschitzOnWith_iff_restrict
#align lipschitz_on_with.to_restrict LipschitzOnWith.to_restrict
theorem MapsTo.lipschitzOnWith_iff_restrict [PseudoEMetricSpace α] [PseudoEMetricSpace β] {K : ℝ≥0}
{f : α → β} {s : Set α} {t : Set β} (h : MapsTo f s t) :
LipschitzOnWith K f s ↔ LipschitzWith K (h.restrict f s t) :=
_root_.lipschitzOnWith_iff_restrict
#align maps_to.lipschitz_on_with_iff_restrict MapsTo.lipschitzOnWith_iff_restrict
alias ⟨LipschitzOnWith.to_restrict_mapsTo, _⟩ := MapsTo.lipschitzOnWith_iff_restrict
#align lipschitz_on_with.to_restrict_maps_to LipschitzOnWith.to_restrict_mapsTo
namespace LipschitzWith
open EMetric
variable [PseudoEMetricSpace α] [PseudoEMetricSpace β] [PseudoEMetricSpace γ]
variable {K : ℝ≥0} {f : α → β} {x y : α} {r : ℝ≥0∞}
protected theorem lipschitzOnWith (h : LipschitzWith K f) (s : Set α) : LipschitzOnWith K f s :=
fun x _ y _ => h x y
#align lipschitz_with.lipschitz_on_with LipschitzWith.lipschitzOnWith
theorem edist_le_mul (h : LipschitzWith K f) (x y : α) : edist (f x) (f y) ≤ K * edist x y :=
h x y
#align lipschitz_with.edist_le_mul LipschitzWith.edist_le_mul
theorem edist_le_mul_of_le (h : LipschitzWith K f) (hr : edist x y ≤ r) :
edist (f x) (f y) ≤ K * r :=
(h x y).trans <| ENNReal.mul_left_mono hr
#align lipschitz_with.edist_le_mul_of_le LipschitzWith.edist_le_mul_of_le
theorem edist_lt_mul_of_lt (h : LipschitzWith K f) (hK : K ≠ 0) (hr : edist x y < r) :
edist (f x) (f y) < K * r :=
(h x y).trans_lt <| (ENNReal.mul_lt_mul_left (ENNReal.coe_ne_zero.2 hK) ENNReal.coe_ne_top).2 hr
#align lipschitz_with.edist_lt_mul_of_lt LipschitzWith.edist_lt_mul_of_lt
theorem mapsTo_emetric_closedBall (h : LipschitzWith K f) (x : α) (r : ℝ≥0∞) :
MapsTo f (closedBall x r) (closedBall (f x) (K * r)) := fun _y hy => h.edist_le_mul_of_le hy
#align lipschitz_with.maps_to_emetric_closed_ball LipschitzWith.mapsTo_emetric_closedBall
theorem mapsTo_emetric_ball (h : LipschitzWith K f) (hK : K ≠ 0) (x : α) (r : ℝ≥0∞) :
MapsTo f (ball x r) (ball (f x) (K * r)) := fun _y hy => h.edist_lt_mul_of_lt hK hy
#align lipschitz_with.maps_to_emetric_ball LipschitzWith.mapsTo_emetric_ball
theorem edist_lt_top (hf : LipschitzWith K f) {x y : α} (h : edist x y ≠ ⊤) :
edist (f x) (f y) < ⊤ :=
(hf x y).trans_lt <| ENNReal.mul_lt_top ENNReal.coe_ne_top h
#align lipschitz_with.edist_lt_top LipschitzWith.edist_lt_top
| Mathlib/Topology/EMetricSpace/Lipschitz.lean | 141 | 144 | theorem mul_edist_le (h : LipschitzWith K f) (x y : α) :
(K⁻¹ : ℝ≥0∞) * edist (f x) (f y) ≤ edist x y := by |
rw [mul_comm, ← div_eq_mul_inv]
exact ENNReal.div_le_of_le_mul' (h x y)
|
import Mathlib.Order.Interval.Set.UnorderedInterval
import Mathlib.Algebra.Order.Interval.Set.Monoid
import Mathlib.Data.Set.Pointwise.Basic
import Mathlib.Algebra.Order.Field.Basic
import Mathlib.Algebra.Order.Group.MinMax
#align_import data.set.pointwise.interval from "leanprover-community/mathlib"@"2196ab363eb097c008d4497125e0dde23fb36db2"
open Interval Pointwise
variable {α : Type*}
namespace Set
section OrderedAddCommGroup
variable [OrderedAddCommGroup α] (a b c : α)
@[simp]
theorem preimage_const_add_Ici : (fun x => a + x) ⁻¹' Ici b = Ici (b - a) :=
ext fun _x => sub_le_iff_le_add'.symm
#align set.preimage_const_add_Ici Set.preimage_const_add_Ici
@[simp]
theorem preimage_const_add_Ioi : (fun x => a + x) ⁻¹' Ioi b = Ioi (b - a) :=
ext fun _x => sub_lt_iff_lt_add'.symm
#align set.preimage_const_add_Ioi Set.preimage_const_add_Ioi
@[simp]
theorem preimage_const_add_Iic : (fun x => a + x) ⁻¹' Iic b = Iic (b - a) :=
ext fun _x => le_sub_iff_add_le'.symm
#align set.preimage_const_add_Iic Set.preimage_const_add_Iic
@[simp]
theorem preimage_const_add_Iio : (fun x => a + x) ⁻¹' Iio b = Iio (b - a) :=
ext fun _x => lt_sub_iff_add_lt'.symm
#align set.preimage_const_add_Iio Set.preimage_const_add_Iio
@[simp]
theorem preimage_const_add_Icc : (fun x => a + x) ⁻¹' Icc b c = Icc (b - a) (c - a) := by
simp [← Ici_inter_Iic]
#align set.preimage_const_add_Icc Set.preimage_const_add_Icc
@[simp]
theorem preimage_const_add_Ico : (fun x => a + x) ⁻¹' Ico b c = Ico (b - a) (c - a) := by
simp [← Ici_inter_Iio]
#align set.preimage_const_add_Ico Set.preimage_const_add_Ico
@[simp]
theorem preimage_const_add_Ioc : (fun x => a + x) ⁻¹' Ioc b c = Ioc (b - a) (c - a) := by
simp [← Ioi_inter_Iic]
#align set.preimage_const_add_Ioc Set.preimage_const_add_Ioc
@[simp]
theorem preimage_const_add_Ioo : (fun x => a + x) ⁻¹' Ioo b c = Ioo (b - a) (c - a) := by
simp [← Ioi_inter_Iio]
#align set.preimage_const_add_Ioo Set.preimage_const_add_Ioo
@[simp]
theorem preimage_add_const_Ici : (fun x => x + a) ⁻¹' Ici b = Ici (b - a) :=
ext fun _x => sub_le_iff_le_add.symm
#align set.preimage_add_const_Ici Set.preimage_add_const_Ici
@[simp]
theorem preimage_add_const_Ioi : (fun x => x + a) ⁻¹' Ioi b = Ioi (b - a) :=
ext fun _x => sub_lt_iff_lt_add.symm
#align set.preimage_add_const_Ioi Set.preimage_add_const_Ioi
@[simp]
theorem preimage_add_const_Iic : (fun x => x + a) ⁻¹' Iic b = Iic (b - a) :=
ext fun _x => le_sub_iff_add_le.symm
#align set.preimage_add_const_Iic Set.preimage_add_const_Iic
@[simp]
theorem preimage_add_const_Iio : (fun x => x + a) ⁻¹' Iio b = Iio (b - a) :=
ext fun _x => lt_sub_iff_add_lt.symm
#align set.preimage_add_const_Iio Set.preimage_add_const_Iio
@[simp]
theorem preimage_add_const_Icc : (fun x => x + a) ⁻¹' Icc b c = Icc (b - a) (c - a) := by
simp [← Ici_inter_Iic]
#align set.preimage_add_const_Icc Set.preimage_add_const_Icc
@[simp]
theorem preimage_add_const_Ico : (fun x => x + a) ⁻¹' Ico b c = Ico (b - a) (c - a) := by
simp [← Ici_inter_Iio]
#align set.preimage_add_const_Ico Set.preimage_add_const_Ico
@[simp]
theorem preimage_add_const_Ioc : (fun x => x + a) ⁻¹' Ioc b c = Ioc (b - a) (c - a) := by
simp [← Ioi_inter_Iic]
#align set.preimage_add_const_Ioc Set.preimage_add_const_Ioc
@[simp]
theorem preimage_add_const_Ioo : (fun x => x + a) ⁻¹' Ioo b c = Ioo (b - a) (c - a) := by
simp [← Ioi_inter_Iio]
#align set.preimage_add_const_Ioo Set.preimage_add_const_Ioo
@[simp]
theorem preimage_neg_Ici : -Ici a = Iic (-a) :=
ext fun _x => le_neg
#align set.preimage_neg_Ici Set.preimage_neg_Ici
@[simp]
theorem preimage_neg_Iic : -Iic a = Ici (-a) :=
ext fun _x => neg_le
#align set.preimage_neg_Iic Set.preimage_neg_Iic
@[simp]
theorem preimage_neg_Ioi : -Ioi a = Iio (-a) :=
ext fun _x => lt_neg
#align set.preimage_neg_Ioi Set.preimage_neg_Ioi
@[simp]
theorem preimage_neg_Iio : -Iio a = Ioi (-a) :=
ext fun _x => neg_lt
#align set.preimage_neg_Iio Set.preimage_neg_Iio
@[simp]
theorem preimage_neg_Icc : -Icc a b = Icc (-b) (-a) := by simp [← Ici_inter_Iic, inter_comm]
#align set.preimage_neg_Icc Set.preimage_neg_Icc
@[simp]
theorem preimage_neg_Ico : -Ico a b = Ioc (-b) (-a) := by
simp [← Ici_inter_Iio, ← Ioi_inter_Iic, inter_comm]
#align set.preimage_neg_Ico Set.preimage_neg_Ico
@[simp]
theorem preimage_neg_Ioc : -Ioc a b = Ico (-b) (-a) := by
simp [← Ioi_inter_Iic, ← Ici_inter_Iio, inter_comm]
#align set.preimage_neg_Ioc Set.preimage_neg_Ioc
@[simp]
theorem preimage_neg_Ioo : -Ioo a b = Ioo (-b) (-a) := by simp [← Ioi_inter_Iio, inter_comm]
#align set.preimage_neg_Ioo Set.preimage_neg_Ioo
@[simp]
theorem preimage_sub_const_Ici : (fun x => x - a) ⁻¹' Ici b = Ici (b + a) := by
simp [sub_eq_add_neg]
#align set.preimage_sub_const_Ici Set.preimage_sub_const_Ici
@[simp]
theorem preimage_sub_const_Ioi : (fun x => x - a) ⁻¹' Ioi b = Ioi (b + a) := by
simp [sub_eq_add_neg]
#align set.preimage_sub_const_Ioi Set.preimage_sub_const_Ioi
@[simp]
theorem preimage_sub_const_Iic : (fun x => x - a) ⁻¹' Iic b = Iic (b + a) := by
simp [sub_eq_add_neg]
#align set.preimage_sub_const_Iic Set.preimage_sub_const_Iic
@[simp]
theorem preimage_sub_const_Iio : (fun x => x - a) ⁻¹' Iio b = Iio (b + a) := by
simp [sub_eq_add_neg]
#align set.preimage_sub_const_Iio Set.preimage_sub_const_Iio
@[simp]
theorem preimage_sub_const_Icc : (fun x => x - a) ⁻¹' Icc b c = Icc (b + a) (c + a) := by
simp [sub_eq_add_neg]
#align set.preimage_sub_const_Icc Set.preimage_sub_const_Icc
@[simp]
theorem preimage_sub_const_Ico : (fun x => x - a) ⁻¹' Ico b c = Ico (b + a) (c + a) := by
simp [sub_eq_add_neg]
#align set.preimage_sub_const_Ico Set.preimage_sub_const_Ico
@[simp]
| Mathlib/Data/Set/Pointwise/Interval.lean | 290 | 291 | theorem preimage_sub_const_Ioc : (fun x => x - a) ⁻¹' Ioc b c = Ioc (b + a) (c + a) := by |
simp [sub_eq_add_neg]
|
import Mathlib.Analysis.SpecialFunctions.Pow.NNReal
#align_import analysis.special_functions.pow.asymptotics from "leanprover-community/mathlib"@"0b9eaaa7686280fad8cce467f5c3c57ee6ce77f8"
set_option linter.uppercaseLean3 false
noncomputable section
open scoped Classical
open Real Topology NNReal ENNReal Filter ComplexConjugate Finset Set
section Limits
open Real Filter
theorem tendsto_rpow_atTop {y : ℝ} (hy : 0 < y) : Tendsto (fun x : ℝ => x ^ y) atTop atTop := by
rw [tendsto_atTop_atTop]
intro b
use max b 0 ^ (1 / y)
intro x hx
exact
le_of_max_le_left
(by
convert rpow_le_rpow (rpow_nonneg (le_max_right b 0) (1 / y)) hx (le_of_lt hy)
using 1
rw [← rpow_mul (le_max_right b 0), (eq_div_iff (ne_of_gt hy)).mp rfl, Real.rpow_one])
#align tendsto_rpow_at_top tendsto_rpow_atTop
theorem tendsto_rpow_neg_atTop {y : ℝ} (hy : 0 < y) : Tendsto (fun x : ℝ => x ^ (-y)) atTop (𝓝 0) :=
Tendsto.congr' (eventuallyEq_of_mem (Ioi_mem_atTop 0) fun _ hx => (rpow_neg (le_of_lt hx) y).symm)
(tendsto_rpow_atTop hy).inv_tendsto_atTop
#align tendsto_rpow_neg_at_top tendsto_rpow_neg_atTop
open Asymptotics in
lemma tendsto_rpow_atTop_of_base_lt_one (b : ℝ) (hb₀ : -1 < b) (hb₁ : b < 1) :
Tendsto (b ^ · : ℝ → ℝ) atTop (𝓝 (0:ℝ)) := by
rcases lt_trichotomy b 0 with hb|rfl|hb
case inl => -- b < 0
simp_rw [Real.rpow_def_of_nonpos hb.le, hb.ne, ite_false]
rw [← isLittleO_const_iff (c := (1:ℝ)) one_ne_zero, (one_mul (1 : ℝ)).symm]
refine IsLittleO.mul_isBigO ?exp ?cos
case exp =>
rw [isLittleO_const_iff one_ne_zero]
refine tendsto_exp_atBot.comp <| (tendsto_const_mul_atBot_of_neg ?_).mpr tendsto_id
rw [← log_neg_eq_log, log_neg_iff (by linarith)]
linarith
case cos =>
rw [isBigO_iff]
exact ⟨1, eventually_of_forall fun x => by simp [Real.abs_cos_le_one]⟩
case inr.inl => -- b = 0
refine Tendsto.mono_right ?_ (Iff.mpr pure_le_nhds_iff rfl)
rw [tendsto_pure]
filter_upwards [eventually_ne_atTop 0] with _ hx
simp [hx]
case inr.inr => -- b > 0
simp_rw [Real.rpow_def_of_pos hb]
refine tendsto_exp_atBot.comp <| (tendsto_const_mul_atBot_of_neg ?_).mpr tendsto_id
exact (log_neg_iff hb).mpr hb₁
lemma tendsto_rpow_atTop_of_base_gt_one (b : ℝ) (hb : 1 < b) :
Tendsto (b ^ · : ℝ → ℝ) atBot (𝓝 (0:ℝ)) := by
simp_rw [Real.rpow_def_of_pos (by positivity : 0 < b)]
refine tendsto_exp_atBot.comp <| (tendsto_const_mul_atBot_of_pos ?_).mpr tendsto_id
exact (log_pos_iff (by positivity)).mpr <| by aesop
lemma tendsto_rpow_atBot_of_base_lt_one (b : ℝ) (hb₀ : 0 < b) (hb₁ : b < 1) :
Tendsto (b ^ · : ℝ → ℝ) atBot atTop := by
simp_rw [Real.rpow_def_of_pos (by positivity : 0 < b)]
refine tendsto_exp_atTop.comp <| (tendsto_const_mul_atTop_iff_neg <| tendsto_id (α := ℝ)).mpr ?_
exact (log_neg_iff hb₀).mpr hb₁
lemma tendsto_rpow_atBot_of_base_gt_one (b : ℝ) (hb : 1 < b) :
Tendsto (b ^ · : ℝ → ℝ) atBot (𝓝 0) := by
simp_rw [Real.rpow_def_of_pos (by positivity : 0 < b)]
refine tendsto_exp_atBot.comp <| (tendsto_const_mul_atBot_iff_pos <| tendsto_id (α := ℝ)).mpr ?_
exact (log_pos_iff (by positivity)).mpr <| by aesop
theorem tendsto_rpow_div_mul_add (a b c : ℝ) (hb : 0 ≠ b) :
Tendsto (fun x => x ^ (a / (b * x + c))) atTop (𝓝 1) := by
refine
Tendsto.congr' ?_
((tendsto_exp_nhds_zero_nhds_one.comp
(by
simpa only [mul_zero, pow_one] using
(tendsto_const_nhds (x := a)).mul
(tendsto_div_pow_mul_exp_add_atTop b c 1 hb))).comp
tendsto_log_atTop)
apply eventuallyEq_of_mem (Ioi_mem_atTop (0 : ℝ))
intro x hx
simp only [Set.mem_Ioi, Function.comp_apply] at hx ⊢
rw [exp_log hx, ← exp_log (rpow_pos_of_pos hx (a / (b * x + c))), log_rpow hx (a / (b * x + c))]
field_simp
#align tendsto_rpow_div_mul_add tendsto_rpow_div_mul_add
| Mathlib/Analysis/SpecialFunctions/Pow/Asymptotics.lean | 120 | 122 | theorem tendsto_rpow_div : Tendsto (fun x => x ^ ((1 : ℝ) / x)) atTop (𝓝 1) := by |
convert tendsto_rpow_div_mul_add (1 : ℝ) _ (0 : ℝ) zero_ne_one
ring
|
import Mathlib.Control.Functor.Multivariate
import Mathlib.Data.PFunctor.Univariate.Basic
#align_import data.pfunctor.multivariate.basic from "leanprover-community/mathlib"@"e3d9ab8faa9dea8f78155c6c27d62a621f4c152d"
universe u v
open MvFunctor
@[pp_with_univ]
structure MvPFunctor (n : ℕ) where
A : Type u
B : A → TypeVec.{u} n
#align mvpfunctor MvPFunctor
namespace MvPFunctor
open MvFunctor (LiftP LiftR)
variable {n m : ℕ} (P : MvPFunctor.{u} n)
@[coe]
def Obj (α : TypeVec.{u} n) : Type u :=
Σ a : P.A, P.B a ⟹ α
#align mvpfunctor.obj MvPFunctor.Obj
instance : CoeFun (MvPFunctor.{u} n) (fun _ => TypeVec.{u} n → Type u) where
coe := Obj
def map {α β : TypeVec n} (f : α ⟹ β) : P α → P β := fun ⟨a, g⟩ => ⟨a, TypeVec.comp f g⟩
#align mvpfunctor.map MvPFunctor.map
instance : Inhabited (MvPFunctor n) :=
⟨⟨default, default⟩⟩
instance Obj.inhabited {α : TypeVec n} [Inhabited P.A] [∀ i, Inhabited (α i)] :
Inhabited (P α) :=
⟨⟨default, fun _ _ => default⟩⟩
#align mvpfunctor.obj.inhabited MvPFunctor.Obj.inhabited
instance : MvFunctor.{u} P.Obj :=
⟨@MvPFunctor.map n P⟩
theorem map_eq {α β : TypeVec n} (g : α ⟹ β) (a : P.A) (f : P.B a ⟹ α) :
@MvFunctor.map _ P.Obj _ _ _ g ⟨a, f⟩ = ⟨a, g ⊚ f⟩ :=
rfl
#align mvpfunctor.map_eq MvPFunctor.map_eq
theorem id_map {α : TypeVec n} : ∀ x : P α, TypeVec.id <$$> x = x
| ⟨_, _⟩ => rfl
#align mvpfunctor.id_map MvPFunctor.id_map
theorem comp_map {α β γ : TypeVec n} (f : α ⟹ β) (g : β ⟹ γ) :
∀ x : P α, (g ⊚ f) <$$> x = g <$$> f <$$> x
| ⟨_, _⟩ => rfl
#align mvpfunctor.comp_map MvPFunctor.comp_map
instance : LawfulMvFunctor.{u} P.Obj where
id_map := @id_map _ P
comp_map := @comp_map _ P
def const (n : ℕ) (A : Type u) : MvPFunctor n :=
{ A
B := fun _ _ => PEmpty }
#align mvpfunctor.const MvPFunctor.const
def comp (P : MvPFunctor.{u} n) (Q : Fin2 n → MvPFunctor.{u} m) : MvPFunctor m where
A := Σ a₂ : P.1, ∀ i, P.2 a₂ i → (Q i).1
B a i := Σ(j : _) (b : P.2 a.1 j), (Q j).2 (a.snd j b) i
#align mvpfunctor.comp MvPFunctor.comp
variable {P} {Q : Fin2 n → MvPFunctor.{u} m} {α β : TypeVec.{u} m}
def comp.mk (x : P (fun i => Q i α)) : comp P Q α :=
⟨⟨x.1, fun _ a => (x.2 _ a).1⟩, fun i a => (x.snd a.fst a.snd.fst).snd i a.snd.snd⟩
#align mvpfunctor.comp.mk MvPFunctor.comp.mk
def comp.get (x : comp P Q α) : P (fun i => Q i α) :=
⟨x.1.1, fun i a => ⟨x.fst.snd i a, fun (j : Fin2 m) (b : (Q i).B _ j) => x.snd j ⟨i, ⟨a, b⟩⟩⟩⟩
#align mvpfunctor.comp.get MvPFunctor.comp.get
theorem comp.get_map (f : α ⟹ β) (x : comp P Q α) :
comp.get (f <$$> x) = (fun i (x : Q i α) => f <$$> x) <$$> comp.get x := by
rfl
#align mvpfunctor.comp.get_map MvPFunctor.comp.get_map
@[simp]
theorem comp.get_mk (x : P (fun i => Q i α)) : comp.get (comp.mk x) = x := by
rfl
#align mvpfunctor.comp.get_mk MvPFunctor.comp.get_mk
@[simp]
theorem comp.mk_get (x : comp P Q α) : comp.mk (comp.get x) = x := by
rfl
#align mvpfunctor.comp.mk_get MvPFunctor.comp.mk_get
theorem liftP_iff {α : TypeVec n} (p : ∀ ⦃i⦄, α i → Prop) (x : P α) :
LiftP p x ↔ ∃ a f, x = ⟨a, f⟩ ∧ ∀ i j, p (f i j) := by
constructor
· rintro ⟨y, hy⟩
cases' h : y with a f
refine ⟨a, fun i j => (f i j).val, ?_, fun i j => (f i j).property⟩
rw [← hy, h, map_eq]
rfl
rintro ⟨a, f, xeq, pf⟩
use ⟨a, fun i j => ⟨f i j, pf i j⟩⟩
rw [xeq]; rfl
#align mvpfunctor.liftp_iff MvPFunctor.liftP_iff
theorem liftP_iff' {α : TypeVec n} (p : ∀ ⦃i⦄, α i → Prop) (a : P.A) (f : P.B a ⟹ α) :
@LiftP.{u} _ P.Obj _ α p ⟨a, f⟩ ↔ ∀ i x, p (f i x) := by
simp only [liftP_iff, Sigma.mk.inj_iff]; constructor
· rintro ⟨_, _, ⟨⟩, _⟩
assumption
· intro
repeat' first |constructor|assumption
#align mvpfunctor.liftp_iff' MvPFunctor.liftP_iff'
| Mathlib/Data/PFunctor/Multivariate/Basic.lean | 182 | 201 | theorem liftR_iff {α : TypeVec n} (r : ∀ ⦃i⦄, α i → α i → Prop) (x y : P α) :
LiftR @r x y ↔ ∃ a f₀ f₁, x = ⟨a, f₀⟩ ∧ y = ⟨a, f₁⟩ ∧ ∀ i j, r (f₀ i j) (f₁ i j) := by |
constructor
· rintro ⟨u, xeq, yeq⟩
cases' h : u with a f
use a, fun i j => (f i j).val.fst, fun i j => (f i j).val.snd
constructor
· rw [← xeq, h]
rfl
constructor
· rw [← yeq, h]
rfl
intro i j
exact (f i j).property
rintro ⟨a, f₀, f₁, xeq, yeq, h⟩
use ⟨a, fun i j => ⟨(f₀ i j, f₁ i j), h i j⟩⟩
dsimp; constructor
· rw [xeq]
rfl
rw [yeq]; rfl
|
import Mathlib.LinearAlgebra.Contraction
import Mathlib.LinearAlgebra.Matrix.Charpoly.Coeff
#align_import linear_algebra.trace from "leanprover-community/mathlib"@"4cf7ca0e69e048b006674cf4499e5c7d296a89e0"
noncomputable section
universe u v w
namespace LinearMap
open Matrix
open FiniteDimensional
open TensorProduct
section
variable (R : Type u) [CommSemiring R] {M : Type v} [AddCommMonoid M] [Module R M]
variable {ι : Type w} [DecidableEq ι] [Fintype ι]
variable {κ : Type*} [DecidableEq κ] [Fintype κ]
variable (b : Basis ι R M) (c : Basis κ R M)
def traceAux : (M →ₗ[R] M) →ₗ[R] R :=
Matrix.traceLinearMap ι R R ∘ₗ ↑(LinearMap.toMatrix b b)
#align linear_map.trace_aux LinearMap.traceAux
-- Can't be `simp` because it would cause a loop.
theorem traceAux_def (b : Basis ι R M) (f : M →ₗ[R] M) :
traceAux R b f = Matrix.trace (LinearMap.toMatrix b b f) :=
rfl
#align linear_map.trace_aux_def LinearMap.traceAux_def
theorem traceAux_eq : traceAux R b = traceAux R c :=
LinearMap.ext fun f =>
calc
Matrix.trace (LinearMap.toMatrix b b f) =
Matrix.trace (LinearMap.toMatrix b b ((LinearMap.id.comp f).comp LinearMap.id)) := by
rw [LinearMap.id_comp, LinearMap.comp_id]
_ = Matrix.trace (LinearMap.toMatrix c b LinearMap.id * LinearMap.toMatrix c c f *
LinearMap.toMatrix b c LinearMap.id) := by
rw [LinearMap.toMatrix_comp _ c, LinearMap.toMatrix_comp _ c]
_ = Matrix.trace (LinearMap.toMatrix c c f * LinearMap.toMatrix b c LinearMap.id *
LinearMap.toMatrix c b LinearMap.id) := by
rw [Matrix.mul_assoc, Matrix.trace_mul_comm]
_ = Matrix.trace (LinearMap.toMatrix c c ((f.comp LinearMap.id).comp LinearMap.id)) := by
rw [LinearMap.toMatrix_comp _ b, LinearMap.toMatrix_comp _ c]
_ = Matrix.trace (LinearMap.toMatrix c c f) := by rw [LinearMap.comp_id, LinearMap.comp_id]
#align linear_map.trace_aux_eq LinearMap.traceAux_eq
open scoped Classical
variable (M)
def trace : (M →ₗ[R] M) →ₗ[R] R :=
if H : ∃ s : Finset M, Nonempty (Basis s R M) then traceAux R H.choose_spec.some else 0
#align linear_map.trace LinearMap.trace
variable {M}
theorem trace_eq_matrix_trace_of_finset {s : Finset M} (b : Basis s R M) (f : M →ₗ[R] M) :
trace R M f = Matrix.trace (LinearMap.toMatrix b b f) := by
have : ∃ s : Finset M, Nonempty (Basis s R M) := ⟨s, ⟨b⟩⟩
rw [trace, dif_pos this, ← traceAux_def]
congr 1
apply traceAux_eq
#align linear_map.trace_eq_matrix_trace_of_finset LinearMap.trace_eq_matrix_trace_of_finset
theorem trace_eq_matrix_trace (f : M →ₗ[R] M) :
trace R M f = Matrix.trace (LinearMap.toMatrix b b f) := by
rw [trace_eq_matrix_trace_of_finset R b.reindexFinsetRange, ← traceAux_def, ← traceAux_def,
traceAux_eq R b b.reindexFinsetRange]
#align linear_map.trace_eq_matrix_trace LinearMap.trace_eq_matrix_trace
theorem trace_mul_comm (f g : M →ₗ[R] M) : trace R M (f * g) = trace R M (g * f) :=
if H : ∃ s : Finset M, Nonempty (Basis s R M) then by
let ⟨s, ⟨b⟩⟩ := H
simp_rw [trace_eq_matrix_trace R b, LinearMap.toMatrix_mul]
apply Matrix.trace_mul_comm
else by rw [trace, dif_neg H, LinearMap.zero_apply, LinearMap.zero_apply]
#align linear_map.trace_mul_comm LinearMap.trace_mul_comm
lemma trace_mul_cycle (f g h : M →ₗ[R] M) :
trace R M (f * g * h) = trace R M (h * f * g) := by
rw [LinearMap.trace_mul_comm, ← mul_assoc]
lemma trace_mul_cycle' (f g h : M →ₗ[R] M) :
trace R M (f * (g * h)) = trace R M (h * (f * g)) := by
rw [← mul_assoc, LinearMap.trace_mul_comm]
@[simp]
theorem trace_conj (g : M →ₗ[R] M) (f : (M →ₗ[R] M)ˣ) :
trace R M (↑f * g * ↑f⁻¹) = trace R M g := by
rw [trace_mul_comm]
simp
#align linear_map.trace_conj LinearMap.trace_conj
@[simp]
lemma trace_lie {R M : Type*} [CommRing R] [AddCommGroup M] [Module R M] (f g : Module.End R M) :
trace R M ⁅f, g⁆ = 0 := by
rw [Ring.lie_def, map_sub, trace_mul_comm]
exact sub_self _
end
section
variable {R : Type*} [CommRing R] {M : Type*} [AddCommGroup M] [Module R M]
variable (N P : Type*) [AddCommGroup N] [Module R N] [AddCommGroup P] [Module R P]
variable {ι : Type*}
| Mathlib/LinearAlgebra/Trace.lean | 138 | 150 | theorem trace_eq_contract_of_basis [Finite ι] (b : Basis ι R M) :
LinearMap.trace R M ∘ₗ dualTensorHom R M M = contractLeft R M := by |
classical
cases nonempty_fintype ι
apply Basis.ext (Basis.tensorProduct (Basis.dualBasis b) b)
rintro ⟨i, j⟩
simp only [Function.comp_apply, Basis.tensorProduct_apply, Basis.coe_dualBasis, coe_comp]
rw [trace_eq_matrix_trace R b, toMatrix_dualTensorHom]
by_cases hij : i = j
· rw [hij]
simp
rw [Matrix.StdBasisMatrix.trace_zero j i (1 : R) hij]
simp [Finsupp.single_eq_pi_single, hij]
|
import Mathlib.Data.Nat.Defs
import Mathlib.Data.Option.Basic
import Mathlib.Data.List.Defs
import Mathlib.Init.Data.List.Basic
import Mathlib.Init.Data.List.Instances
import Mathlib.Init.Data.List.Lemmas
import Mathlib.Logic.Unique
import Mathlib.Order.Basic
import Mathlib.Tactic.Common
#align_import data.list.basic from "leanprover-community/mathlib"@"65a1391a0106c9204fe45bc73a039f056558cb83"
assert_not_exists Set.range
assert_not_exists GroupWithZero
assert_not_exists Ring
open Function
open Nat hiding one_pos
namespace List
universe u v w
variable {ι : Type*} {α : Type u} {β : Type v} {γ : Type w} {l₁ l₂ : List α}
-- Porting note: Delete this attribute
-- attribute [inline] List.head!
instance uniqueOfIsEmpty [IsEmpty α] : Unique (List α) :=
{ instInhabitedList with
uniq := fun l =>
match l with
| [] => rfl
| a :: _ => isEmptyElim a }
#align list.unique_of_is_empty List.uniqueOfIsEmpty
instance : Std.LawfulIdentity (α := List α) Append.append [] where
left_id := nil_append
right_id := append_nil
instance : Std.Associative (α := List α) Append.append where
assoc := append_assoc
#align list.cons_ne_nil List.cons_ne_nil
#align list.cons_ne_self List.cons_ne_self
#align list.head_eq_of_cons_eq List.head_eq_of_cons_eqₓ -- implicits order
#align list.tail_eq_of_cons_eq List.tail_eq_of_cons_eqₓ -- implicits order
@[simp] theorem cons_injective {a : α} : Injective (cons a) := fun _ _ => tail_eq_of_cons_eq
#align list.cons_injective List.cons_injective
#align list.cons_inj List.cons_inj
#align list.cons_eq_cons List.cons_eq_cons
theorem singleton_injective : Injective fun a : α => [a] := fun _ _ h => (cons_eq_cons.1 h).1
#align list.singleton_injective List.singleton_injective
theorem singleton_inj {a b : α} : [a] = [b] ↔ a = b :=
singleton_injective.eq_iff
#align list.singleton_inj List.singleton_inj
#align list.exists_cons_of_ne_nil List.exists_cons_of_ne_nil
theorem set_of_mem_cons (l : List α) (a : α) : { x | x ∈ a :: l } = insert a { x | x ∈ l } :=
Set.ext fun _ => mem_cons
#align list.set_of_mem_cons List.set_of_mem_cons
#align list.mem_singleton_self List.mem_singleton_self
#align list.eq_of_mem_singleton List.eq_of_mem_singleton
#align list.mem_singleton List.mem_singleton
#align list.mem_of_mem_cons_of_mem List.mem_of_mem_cons_of_mem
theorem _root_.Decidable.List.eq_or_ne_mem_of_mem [DecidableEq α]
{a b : α} {l : List α} (h : a ∈ b :: l) : a = b ∨ a ≠ b ∧ a ∈ l := by
by_cases hab : a = b
· exact Or.inl hab
· exact ((List.mem_cons.1 h).elim Or.inl (fun h => Or.inr ⟨hab, h⟩))
#align decidable.list.eq_or_ne_mem_of_mem Decidable.List.eq_or_ne_mem_of_mem
#align list.eq_or_ne_mem_of_mem List.eq_or_ne_mem_of_mem
#align list.not_mem_append List.not_mem_append
#align list.ne_nil_of_mem List.ne_nil_of_mem
lemma mem_pair {a b c : α} : a ∈ [b, c] ↔ a = b ∨ a = c := by
rw [mem_cons, mem_singleton]
@[deprecated (since := "2024-03-23")] alias mem_split := append_of_mem
#align list.mem_split List.append_of_mem
#align list.mem_of_ne_of_mem List.mem_of_ne_of_mem
#align list.ne_of_not_mem_cons List.ne_of_not_mem_cons
#align list.not_mem_of_not_mem_cons List.not_mem_of_not_mem_cons
#align list.not_mem_cons_of_ne_of_not_mem List.not_mem_cons_of_ne_of_not_mem
#align list.ne_and_not_mem_of_not_mem_cons List.ne_and_not_mem_of_not_mem_cons
#align list.mem_map List.mem_map
#align list.exists_of_mem_map List.exists_of_mem_map
#align list.mem_map_of_mem List.mem_map_of_memₓ -- implicits order
-- The simpNF linter says that the LHS can be simplified via `List.mem_map`.
-- However this is a higher priority lemma.
-- https://github.com/leanprover/std4/issues/207
@[simp 1100, nolint simpNF]
theorem mem_map_of_injective {f : α → β} (H : Injective f) {a : α} {l : List α} :
f a ∈ map f l ↔ a ∈ l :=
⟨fun m => let ⟨_, m', e⟩ := exists_of_mem_map m; H e ▸ m', mem_map_of_mem _⟩
#align list.mem_map_of_injective List.mem_map_of_injective
@[simp]
theorem _root_.Function.Involutive.exists_mem_and_apply_eq_iff {f : α → α}
(hf : Function.Involutive f) (x : α) (l : List α) : (∃ y : α, y ∈ l ∧ f y = x) ↔ f x ∈ l :=
⟨by rintro ⟨y, h, rfl⟩; rwa [hf y], fun h => ⟨f x, h, hf _⟩⟩
#align function.involutive.exists_mem_and_apply_eq_iff Function.Involutive.exists_mem_and_apply_eq_iff
theorem mem_map_of_involutive {f : α → α} (hf : Involutive f) {a : α} {l : List α} :
a ∈ map f l ↔ f a ∈ l := by rw [mem_map, hf.exists_mem_and_apply_eq_iff]
#align list.mem_map_of_involutive List.mem_map_of_involutive
#align list.forall_mem_map_iff List.forall_mem_map_iffₓ -- universe order
#align list.map_eq_nil List.map_eq_nilₓ -- universe order
attribute [simp] List.mem_join
#align list.mem_join List.mem_join
#align list.exists_of_mem_join List.exists_of_mem_join
#align list.mem_join_of_mem List.mem_join_of_memₓ -- implicits order
attribute [simp] List.mem_bind
#align list.mem_bind List.mem_bindₓ -- implicits order
-- Porting note: bExists in Lean3, And in Lean4
#align list.exists_of_mem_bind List.exists_of_mem_bindₓ -- implicits order
#align list.mem_bind_of_mem List.mem_bind_of_memₓ -- implicits order
#align list.bind_map List.bind_mapₓ -- implicits order
theorem map_bind (g : β → List γ) (f : α → β) :
∀ l : List α, (List.map f l).bind g = l.bind fun a => g (f a)
| [] => rfl
| a :: l => by simp only [cons_bind, map_cons, map_bind _ _ l]
#align list.map_bind List.map_bind
#align list.length_eq_zero List.length_eq_zero
#align list.length_singleton List.length_singleton
#align list.length_pos_of_mem List.length_pos_of_mem
#align list.exists_mem_of_length_pos List.exists_mem_of_length_pos
#align list.length_pos_iff_exists_mem List.length_pos_iff_exists_mem
alias ⟨ne_nil_of_length_pos, length_pos_of_ne_nil⟩ := length_pos
#align list.ne_nil_of_length_pos List.ne_nil_of_length_pos
#align list.length_pos_of_ne_nil List.length_pos_of_ne_nil
theorem length_pos_iff_ne_nil {l : List α} : 0 < length l ↔ l ≠ [] :=
⟨ne_nil_of_length_pos, length_pos_of_ne_nil⟩
#align list.length_pos_iff_ne_nil List.length_pos_iff_ne_nil
#align list.exists_mem_of_ne_nil List.exists_mem_of_ne_nil
#align list.length_eq_one List.length_eq_one
theorem exists_of_length_succ {n} : ∀ l : List α, l.length = n + 1 → ∃ h t, l = h :: t
| [], H => absurd H.symm <| succ_ne_zero n
| h :: t, _ => ⟨h, t, rfl⟩
#align list.exists_of_length_succ List.exists_of_length_succ
@[simp] lemma length_injective_iff : Injective (List.length : List α → ℕ) ↔ Subsingleton α := by
constructor
· intro h; refine ⟨fun x y => ?_⟩; (suffices [x] = [y] by simpa using this); apply h; rfl
· intros hα l1 l2 hl
induction l1 generalizing l2 <;> cases l2
· rfl
· cases hl
· cases hl
· next ih _ _ =>
congr
· exact Subsingleton.elim _ _
· apply ih; simpa using hl
#align list.length_injective_iff List.length_injective_iff
@[simp default+1] -- Porting note: this used to be just @[simp]
lemma length_injective [Subsingleton α] : Injective (length : List α → ℕ) :=
length_injective_iff.mpr inferInstance
#align list.length_injective List.length_injective
theorem length_eq_two {l : List α} : l.length = 2 ↔ ∃ a b, l = [a, b] :=
⟨fun _ => let [a, b] := l; ⟨a, b, rfl⟩, fun ⟨_, _, e⟩ => e ▸ rfl⟩
#align list.length_eq_two List.length_eq_two
theorem length_eq_three {l : List α} : l.length = 3 ↔ ∃ a b c, l = [a, b, c] :=
⟨fun _ => let [a, b, c] := l; ⟨a, b, c, rfl⟩, fun ⟨_, _, _, e⟩ => e ▸ rfl⟩
#align list.length_eq_three List.length_eq_three
#align list.sublist.length_le List.Sublist.length_le
-- ADHOC Porting note: instance from Lean3 core
instance instSingletonList : Singleton α (List α) := ⟨fun x => [x]⟩
#align list.has_singleton List.instSingletonList
-- ADHOC Porting note: instance from Lean3 core
instance [DecidableEq α] : Insert α (List α) := ⟨List.insert⟩
-- ADHOC Porting note: instance from Lean3 core
instance [DecidableEq α] : LawfulSingleton α (List α) :=
{ insert_emptyc_eq := fun x =>
show (if x ∈ ([] : List α) then [] else [x]) = [x] from if_neg (not_mem_nil _) }
#align list.empty_eq List.empty_eq
theorem singleton_eq (x : α) : ({x} : List α) = [x] :=
rfl
#align list.singleton_eq List.singleton_eq
theorem insert_neg [DecidableEq α] {x : α} {l : List α} (h : x ∉ l) :
Insert.insert x l = x :: l :=
insert_of_not_mem h
#align list.insert_neg List.insert_neg
theorem insert_pos [DecidableEq α] {x : α} {l : List α} (h : x ∈ l) : Insert.insert x l = l :=
insert_of_mem h
#align list.insert_pos List.insert_pos
theorem doubleton_eq [DecidableEq α] {x y : α} (h : x ≠ y) : ({x, y} : List α) = [x, y] := by
rw [insert_neg, singleton_eq]
rwa [singleton_eq, mem_singleton]
#align list.doubleton_eq List.doubleton_eq
#align list.forall_mem_nil List.forall_mem_nil
#align list.forall_mem_cons List.forall_mem_cons
theorem forall_mem_of_forall_mem_cons {p : α → Prop} {a : α} {l : List α} (h : ∀ x ∈ a :: l, p x) :
∀ x ∈ l, p x := (forall_mem_cons.1 h).2
#align list.forall_mem_of_forall_mem_cons List.forall_mem_of_forall_mem_cons
#align list.forall_mem_singleton List.forall_mem_singleton
#align list.forall_mem_append List.forall_mem_append
#align list.not_exists_mem_nil List.not_exists_mem_nilₓ -- bExists change
-- Porting note: bExists in Lean3 and And in Lean4
theorem exists_mem_cons_of {p : α → Prop} {a : α} (l : List α) (h : p a) : ∃ x ∈ a :: l, p x :=
⟨a, mem_cons_self _ _, h⟩
#align list.exists_mem_cons_of List.exists_mem_cons_ofₓ -- bExists change
-- Porting note: bExists in Lean3 and And in Lean4
theorem exists_mem_cons_of_exists {p : α → Prop} {a : α} {l : List α} : (∃ x ∈ l, p x) →
∃ x ∈ a :: l, p x :=
fun ⟨x, xl, px⟩ => ⟨x, mem_cons_of_mem _ xl, px⟩
#align list.exists_mem_cons_of_exists List.exists_mem_cons_of_existsₓ -- bExists change
-- Porting note: bExists in Lean3 and And in Lean4
theorem or_exists_of_exists_mem_cons {p : α → Prop} {a : α} {l : List α} : (∃ x ∈ a :: l, p x) →
p a ∨ ∃ x ∈ l, p x :=
fun ⟨x, xal, px⟩ =>
Or.elim (eq_or_mem_of_mem_cons xal) (fun h : x = a => by rw [← h]; left; exact px)
fun h : x ∈ l => Or.inr ⟨x, h, px⟩
#align list.or_exists_of_exists_mem_cons List.or_exists_of_exists_mem_consₓ -- bExists change
theorem exists_mem_cons_iff (p : α → Prop) (a : α) (l : List α) :
(∃ x ∈ a :: l, p x) ↔ p a ∨ ∃ x ∈ l, p x :=
Iff.intro or_exists_of_exists_mem_cons fun h =>
Or.elim h (exists_mem_cons_of l) exists_mem_cons_of_exists
#align list.exists_mem_cons_iff List.exists_mem_cons_iff
instance : IsTrans (List α) Subset where
trans := fun _ _ _ => List.Subset.trans
#align list.subset_def List.subset_def
#align list.subset_append_of_subset_left List.subset_append_of_subset_left
#align list.subset_append_of_subset_right List.subset_append_of_subset_right
#align list.cons_subset List.cons_subset
theorem cons_subset_of_subset_of_mem {a : α} {l m : List α}
(ainm : a ∈ m) (lsubm : l ⊆ m) : a::l ⊆ m :=
cons_subset.2 ⟨ainm, lsubm⟩
#align list.cons_subset_of_subset_of_mem List.cons_subset_of_subset_of_mem
theorem append_subset_of_subset_of_subset {l₁ l₂ l : List α} (l₁subl : l₁ ⊆ l) (l₂subl : l₂ ⊆ l) :
l₁ ++ l₂ ⊆ l :=
fun _ h ↦ (mem_append.1 h).elim (@l₁subl _) (@l₂subl _)
#align list.append_subset_of_subset_of_subset List.append_subset_of_subset_of_subset
-- Porting note: in Batteries
#align list.append_subset_iff List.append_subset
alias ⟨eq_nil_of_subset_nil, _⟩ := subset_nil
#align list.eq_nil_of_subset_nil List.eq_nil_of_subset_nil
#align list.eq_nil_iff_forall_not_mem List.eq_nil_iff_forall_not_mem
#align list.map_subset List.map_subset
theorem map_subset_iff {l₁ l₂ : List α} (f : α → β) (h : Injective f) :
map f l₁ ⊆ map f l₂ ↔ l₁ ⊆ l₂ := by
refine ⟨?_, map_subset f⟩; intro h2 x hx
rcases mem_map.1 (h2 (mem_map_of_mem f hx)) with ⟨x', hx', hxx'⟩
cases h hxx'; exact hx'
#align list.map_subset_iff List.map_subset_iff
theorem append_eq_has_append {L₁ L₂ : List α} : List.append L₁ L₂ = L₁ ++ L₂ :=
rfl
#align list.append_eq_has_append List.append_eq_has_append
#align list.singleton_append List.singleton_append
#align list.append_ne_nil_of_ne_nil_left List.append_ne_nil_of_ne_nil_left
#align list.append_ne_nil_of_ne_nil_right List.append_ne_nil_of_ne_nil_right
#align list.append_eq_nil List.append_eq_nil
-- Porting note: in Batteries
#align list.nil_eq_append_iff List.nil_eq_append
@[deprecated (since := "2024-03-24")] alias append_eq_cons_iff := append_eq_cons
#align list.append_eq_cons_iff List.append_eq_cons
@[deprecated (since := "2024-03-24")] alias cons_eq_append_iff := cons_eq_append
#align list.cons_eq_append_iff List.cons_eq_append
#align list.append_eq_append_iff List.append_eq_append_iff
#align list.take_append_drop List.take_append_drop
#align list.append_inj List.append_inj
#align list.append_inj_right List.append_inj_rightₓ -- implicits order
#align list.append_inj_left List.append_inj_leftₓ -- implicits order
#align list.append_inj' List.append_inj'ₓ -- implicits order
#align list.append_inj_right' List.append_inj_right'ₓ -- implicits order
#align list.append_inj_left' List.append_inj_left'ₓ -- implicits order
@[deprecated (since := "2024-01-18")] alias append_left_cancel := append_cancel_left
#align list.append_left_cancel List.append_cancel_left
@[deprecated (since := "2024-01-18")] alias append_right_cancel := append_cancel_right
#align list.append_right_cancel List.append_cancel_right
@[simp] theorem append_left_eq_self {x y : List α} : x ++ y = y ↔ x = [] := by
rw [← append_left_inj (s₁ := x), nil_append]
@[simp] theorem self_eq_append_left {x y : List α} : y = x ++ y ↔ x = [] := by
rw [eq_comm, append_left_eq_self]
@[simp] theorem append_right_eq_self {x y : List α} : x ++ y = x ↔ y = [] := by
rw [← append_right_inj (t₁ := y), append_nil]
@[simp] theorem self_eq_append_right {x y : List α} : x = x ++ y ↔ y = [] := by
rw [eq_comm, append_right_eq_self]
theorem append_right_injective (s : List α) : Injective fun t ↦ s ++ t :=
fun _ _ ↦ append_cancel_left
#align list.append_right_injective List.append_right_injective
#align list.append_right_inj List.append_right_inj
theorem append_left_injective (t : List α) : Injective fun s ↦ s ++ t :=
fun _ _ ↦ append_cancel_right
#align list.append_left_injective List.append_left_injective
#align list.append_left_inj List.append_left_inj
#align list.map_eq_append_split List.map_eq_append_split
@[simp] lemma replicate_zero (a : α) : replicate 0 a = [] := rfl
#align list.replicate_zero List.replicate_zero
attribute [simp] replicate_succ
#align list.replicate_succ List.replicate_succ
lemma replicate_one (a : α) : replicate 1 a = [a] := rfl
#align list.replicate_one List.replicate_one
#align list.length_replicate List.length_replicate
#align list.mem_replicate List.mem_replicate
#align list.eq_of_mem_replicate List.eq_of_mem_replicate
theorem eq_replicate_length {a : α} : ∀ {l : List α}, l = replicate l.length a ↔ ∀ b ∈ l, b = a
| [] => by simp
| (b :: l) => by simp [eq_replicate_length]
#align list.eq_replicate_length List.eq_replicate_length
#align list.eq_replicate_of_mem List.eq_replicate_of_mem
#align list.eq_replicate List.eq_replicate
theorem replicate_add (m n) (a : α) : replicate (m + n) a = replicate m a ++ replicate n a := by
induction m <;> simp [*, succ_add, replicate]
#align list.replicate_add List.replicate_add
theorem replicate_succ' (n) (a : α) : replicate (n + 1) a = replicate n a ++ [a] :=
replicate_add n 1 a
#align list.replicate_succ' List.replicate_succ'
theorem replicate_subset_singleton (n) (a : α) : replicate n a ⊆ [a] := fun _ h =>
mem_singleton.2 (eq_of_mem_replicate h)
#align list.replicate_subset_singleton List.replicate_subset_singleton
theorem subset_singleton_iff {a : α} {L : List α} : L ⊆ [a] ↔ ∃ n, L = replicate n a := by
simp only [eq_replicate, subset_def, mem_singleton, exists_eq_left']
#align list.subset_singleton_iff List.subset_singleton_iff
@[simp] theorem map_replicate (f : α → β) (n) (a : α) :
map f (replicate n a) = replicate n (f a) := by
induction n <;> [rfl; simp only [*, replicate, map]]
#align list.map_replicate List.map_replicate
@[simp] theorem tail_replicate (a : α) (n) :
tail (replicate n a) = replicate (n - 1) a := by cases n <;> rfl
#align list.tail_replicate List.tail_replicate
@[simp] theorem join_replicate_nil (n : ℕ) : join (replicate n []) = @nil α := by
induction n <;> [rfl; simp only [*, replicate, join, append_nil]]
#align list.join_replicate_nil List.join_replicate_nil
theorem replicate_right_injective {n : ℕ} (hn : n ≠ 0) : Injective (@replicate α n) :=
fun _ _ h => (eq_replicate.1 h).2 _ <| mem_replicate.2 ⟨hn, rfl⟩
#align list.replicate_right_injective List.replicate_right_injective
theorem replicate_right_inj {a b : α} {n : ℕ} (hn : n ≠ 0) :
replicate n a = replicate n b ↔ a = b :=
(replicate_right_injective hn).eq_iff
#align list.replicate_right_inj List.replicate_right_inj
@[simp] theorem replicate_right_inj' {a b : α} : ∀ {n},
replicate n a = replicate n b ↔ n = 0 ∨ a = b
| 0 => by simp
| n + 1 => (replicate_right_inj n.succ_ne_zero).trans <| by simp only [n.succ_ne_zero, false_or]
#align list.replicate_right_inj' List.replicate_right_inj'
theorem replicate_left_injective (a : α) : Injective (replicate · a) :=
LeftInverse.injective (length_replicate · a)
#align list.replicate_left_injective List.replicate_left_injective
@[simp] theorem replicate_left_inj {a : α} {n m : ℕ} : replicate n a = replicate m a ↔ n = m :=
(replicate_left_injective a).eq_iff
#align list.replicate_left_inj List.replicate_left_inj
@[simp] theorem head_replicate (n : ℕ) (a : α) (h) : head (replicate n a) h = a := by
cases n <;> simp at h ⊢
theorem mem_pure (x y : α) : x ∈ (pure y : List α) ↔ x = y := by simp
#align list.mem_pure List.mem_pure
@[simp]
theorem bind_eq_bind {α β} (f : α → List β) (l : List α) : l >>= f = l.bind f :=
rfl
#align list.bind_eq_bind List.bind_eq_bind
#align list.bind_append List.append_bind
#align list.concat_nil List.concat_nil
#align list.concat_cons List.concat_cons
#align list.concat_eq_append List.concat_eq_append
#align list.init_eq_of_concat_eq List.init_eq_of_concat_eq
#align list.last_eq_of_concat_eq List.last_eq_of_concat_eq
#align list.concat_ne_nil List.concat_ne_nil
#align list.concat_append List.concat_append
#align list.length_concat List.length_concat
#align list.append_concat List.append_concat
#align list.reverse_nil List.reverse_nil
#align list.reverse_core List.reverseAux
-- Porting note: Do we need this?
attribute [local simp] reverseAux
#align list.reverse_cons List.reverse_cons
#align list.reverse_core_eq List.reverseAux_eq
| Mathlib/Data/List/Basic.lean | 528 | 529 | theorem reverse_cons' (a : α) (l : List α) : reverse (a :: l) = concat (reverse l) a := by |
simp only [reverse_cons, concat_eq_append]
|
import Mathlib.MeasureTheory.MeasurableSpace.Basic
import Mathlib.MeasureTheory.Measure.MeasureSpaceDef
#align_import measure_theory.function.ae_measurable_sequence from "leanprover-community/mathlib"@"d003c55042c3cd08aefd1ae9a42ef89441cdaaf3"
open MeasureTheory
open scoped Classical
variable {ι : Sort*} {α β γ : Type*} [MeasurableSpace α] [MeasurableSpace β] {f : ι → α → β}
{μ : Measure α} {p : α → (ι → β) → Prop}
def aeSeqSet (hf : ∀ i, AEMeasurable (f i) μ) (p : α → (ι → β) → Prop) : Set α :=
(toMeasurable μ { x | (∀ i, f i x = (hf i).mk (f i) x) ∧ p x fun n => f n x }ᶜ)ᶜ
#align ae_seq_set aeSeqSet
noncomputable def aeSeq (hf : ∀ i, AEMeasurable (f i) μ) (p : α → (ι → β) → Prop) : ι → α → β :=
fun i x => ite (x ∈ aeSeqSet hf p) ((hf i).mk (f i) x) (⟨f i x⟩ : Nonempty β).some
#align ae_seq aeSeq
namespace aeSeq
section MemAESeqSet
| Mathlib/MeasureTheory/Function/AEMeasurableSequence.lean | 50 | 56 | theorem mk_eq_fun_of_mem_aeSeqSet (hf : ∀ i, AEMeasurable (f i) μ) {x : α} (hx : x ∈ aeSeqSet hf p)
(i : ι) : (hf i).mk (f i) x = f i x :=
haveI h_ss : aeSeqSet hf p ⊆ { x | ∀ i, f i x = (hf i).mk (f i) x } := by |
rw [aeSeqSet, ← compl_compl { x | ∀ i, f i x = (hf i).mk (f i) x }, Set.compl_subset_compl]
refine Set.Subset.trans (Set.compl_subset_compl.mpr fun x h => ?_) (subset_toMeasurable _ _)
exact h.1
(h_ss hx i).symm
|
import Mathlib.Probability.ConditionalProbability
import Mathlib.MeasureTheory.Measure.Count
#align_import probability.cond_count from "leanprover-community/mathlib"@"117e93f82b5f959f8193857370109935291f0cc4"
noncomputable section
open ProbabilityTheory
open MeasureTheory MeasurableSpace
namespace ProbabilityTheory
variable {Ω : Type*} [MeasurableSpace Ω]
def condCount (s : Set Ω) : Measure Ω :=
Measure.count[|s]
#align probability_theory.cond_count ProbabilityTheory.condCount
@[simp]
theorem condCount_empty_meas : (condCount ∅ : Measure Ω) = 0 := by simp [condCount]
#align probability_theory.cond_count_empty_meas ProbabilityTheory.condCount_empty_meas
theorem condCount_empty {s : Set Ω} : condCount s ∅ = 0 := by simp
#align probability_theory.cond_count_empty ProbabilityTheory.condCount_empty
theorem finite_of_condCount_ne_zero {s t : Set Ω} (h : condCount s t ≠ 0) : s.Finite := by
by_contra hs'
simp [condCount, cond, Measure.count_apply_infinite hs'] at h
#align probability_theory.finite_of_cond_count_ne_zero ProbabilityTheory.finite_of_condCount_ne_zero
theorem condCount_univ [Fintype Ω] {s : Set Ω} :
condCount Set.univ s = Measure.count s / Fintype.card Ω := by
rw [condCount, cond_apply _ MeasurableSet.univ, ← ENNReal.div_eq_inv_mul, Set.univ_inter]
congr
rw [← Finset.coe_univ, Measure.count_apply, Finset.univ.tsum_subtype' fun _ => (1 : ENNReal)]
· simp [Finset.card_univ]
· exact (@Finset.coe_univ Ω _).symm ▸ MeasurableSet.univ
#align probability_theory.cond_count_univ ProbabilityTheory.condCount_univ
variable [MeasurableSingletonClass Ω]
theorem condCount_isProbabilityMeasure {s : Set Ω} (hs : s.Finite) (hs' : s.Nonempty) :
IsProbabilityMeasure (condCount s) :=
{ measure_univ := by
rw [condCount, cond_apply _ hs.measurableSet, Set.inter_univ, ENNReal.inv_mul_cancel]
· exact fun h => hs'.ne_empty <| Measure.empty_of_count_eq_zero h
· exact (Measure.count_apply_lt_top.2 hs).ne }
#align probability_theory.cond_count_is_probability_measure ProbabilityTheory.condCount_isProbabilityMeasure
theorem condCount_singleton (ω : Ω) (t : Set Ω) [Decidable (ω ∈ t)] :
condCount {ω} t = if ω ∈ t then 1 else 0 := by
rw [condCount, cond_apply _ (measurableSet_singleton ω), Measure.count_singleton, inv_one,
one_mul]
split_ifs
· rw [(by simpa : ({ω} : Set Ω) ∩ t = {ω}), Measure.count_singleton]
· rw [(by simpa : ({ω} : Set Ω) ∩ t = ∅), Measure.count_empty]
#align probability_theory.cond_count_singleton ProbabilityTheory.condCount_singleton
variable {s t u : Set Ω}
theorem condCount_inter_self (hs : s.Finite) : condCount s (s ∩ t) = condCount s t := by
rw [condCount, cond_inter_self _ hs.measurableSet]
#align probability_theory.cond_count_inter_self ProbabilityTheory.condCount_inter_self
theorem condCount_self (hs : s.Finite) (hs' : s.Nonempty) : condCount s s = 1 := by
rw [condCount, cond_apply _ hs.measurableSet, Set.inter_self, ENNReal.inv_mul_cancel]
· exact fun h => hs'.ne_empty <| Measure.empty_of_count_eq_zero h
· exact (Measure.count_apply_lt_top.2 hs).ne
#align probability_theory.cond_count_self ProbabilityTheory.condCount_self
theorem condCount_eq_one_of (hs : s.Finite) (hs' : s.Nonempty) (ht : s ⊆ t) :
condCount s t = 1 := by
haveI := condCount_isProbabilityMeasure hs hs'
refine eq_of_le_of_not_lt prob_le_one ?_
rw [not_lt, ← condCount_self hs hs']
exact measure_mono ht
#align probability_theory.cond_count_eq_one_of ProbabilityTheory.condCount_eq_one_of
| Mathlib/Probability/CondCount.lean | 118 | 126 | theorem pred_true_of_condCount_eq_one (h : condCount s t = 1) : s ⊆ t := by |
have hsf := finite_of_condCount_ne_zero (by rw [h]; exact one_ne_zero)
rw [condCount, cond_apply _ hsf.measurableSet, mul_comm] at h
replace h := ENNReal.eq_inv_of_mul_eq_one_left h
rw [inv_inv, Measure.count_apply_finite _ hsf, Measure.count_apply_finite _ (hsf.inter_of_left _),
Nat.cast_inj] at h
suffices s ∩ t = s by exact this ▸ fun x hx => hx.2
rw [← @Set.Finite.toFinset_inj _ _ _ (hsf.inter_of_left _) hsf]
exact Finset.eq_of_subset_of_card_le (Set.Finite.toFinset_mono s.inter_subset_left) h.ge
|
import Mathlib.Algebra.BigOperators.Fin
import Mathlib.Algebra.MvPolynomial.Rename
import Mathlib.Algebra.MvPolynomial.Degrees
import Mathlib.Algebra.Polynomial.AlgebraMap
import Mathlib.Data.Finsupp.Fin
import Mathlib.Logic.Equiv.Fin
#align_import data.mv_polynomial.equiv from "leanprover-community/mathlib"@"2f5b500a507264de86d666a5f87ddb976e2d8de4"
noncomputable section
open Polynomial Set Function Finsupp AddMonoidAlgebra
universe u v w x
variable {R : Type u} {S₁ : Type v} {S₂ : Type w} {S₃ : Type x}
namespace MvPolynomial
variable {σ : Type*} {a a' a₁ a₂ : R} {e : ℕ} {s : σ →₀ ℕ}
section Equiv
variable (R) [CommSemiring R]
@[simps]
def pUnitAlgEquiv : MvPolynomial PUnit R ≃ₐ[R] R[X] where
toFun := eval₂ Polynomial.C fun _ => Polynomial.X
invFun := Polynomial.eval₂ MvPolynomial.C (X PUnit.unit)
left_inv := by
let f : R[X] →+* MvPolynomial PUnit R := Polynomial.eval₂RingHom MvPolynomial.C (X PUnit.unit)
let g : MvPolynomial PUnit R →+* R[X] := eval₂Hom Polynomial.C fun _ => Polynomial.X
show ∀ p, f.comp g p = p
apply is_id
· ext a
dsimp [f, g]
rw [eval₂_C, Polynomial.eval₂_C]
· rintro ⟨⟩
dsimp [f, g]
rw [eval₂_X, Polynomial.eval₂_X]
right_inv p :=
Polynomial.induction_on p (fun a => by rw [Polynomial.eval₂_C, MvPolynomial.eval₂_C])
(fun p q hp hq => by rw [Polynomial.eval₂_add, MvPolynomial.eval₂_add, hp, hq]) fun p n _ => by
rw [Polynomial.eval₂_mul, Polynomial.eval₂_pow, Polynomial.eval₂_X, Polynomial.eval₂_C,
eval₂_mul, eval₂_C, eval₂_pow, eval₂_X]
map_mul' _ _ := eval₂_mul _ _
map_add' _ _ := eval₂_add _ _
commutes' _ := eval₂_C _ _ _
#align mv_polynomial.punit_alg_equiv MvPolynomial.pUnitAlgEquiv
section
variable (S₁ S₂ S₃)
def sumToIter : MvPolynomial (Sum S₁ S₂) R →+* MvPolynomial S₁ (MvPolynomial S₂ R) :=
eval₂Hom (C.comp C) fun bc => Sum.recOn bc X (C ∘ X)
#align mv_polynomial.sum_to_iter MvPolynomial.sumToIter
@[simp]
theorem sumToIter_C (a : R) : sumToIter R S₁ S₂ (C a) = C (C a) :=
eval₂_C _ _ a
set_option linter.uppercaseLean3 false in
#align mv_polynomial.sum_to_iter_C MvPolynomial.sumToIter_C
@[simp]
theorem sumToIter_Xl (b : S₁) : sumToIter R S₁ S₂ (X (Sum.inl b)) = X b :=
eval₂_X _ _ (Sum.inl b)
set_option linter.uppercaseLean3 false in
#align mv_polynomial.sum_to_iter_Xl MvPolynomial.sumToIter_Xl
@[simp]
theorem sumToIter_Xr (c : S₂) : sumToIter R S₁ S₂ (X (Sum.inr c)) = C (X c) :=
eval₂_X _ _ (Sum.inr c)
set_option linter.uppercaseLean3 false in
#align mv_polynomial.sum_to_iter_Xr MvPolynomial.sumToIter_Xr
def iterToSum : MvPolynomial S₁ (MvPolynomial S₂ R) →+* MvPolynomial (Sum S₁ S₂) R :=
eval₂Hom (eval₂Hom C (X ∘ Sum.inr)) (X ∘ Sum.inl)
#align mv_polynomial.iter_to_sum MvPolynomial.iterToSum
@[simp]
theorem iterToSum_C_C (a : R) : iterToSum R S₁ S₂ (C (C a)) = C a :=
Eq.trans (eval₂_C _ _ (C a)) (eval₂_C _ _ _)
set_option linter.uppercaseLean3 false in
#align mv_polynomial.iter_to_sum_C_C MvPolynomial.iterToSum_C_C
@[simp]
theorem iterToSum_X (b : S₁) : iterToSum R S₁ S₂ (X b) = X (Sum.inl b) :=
eval₂_X _ _ _
set_option linter.uppercaseLean3 false in
#align mv_polynomial.iter_to_sum_X MvPolynomial.iterToSum_X
@[simp]
theorem iterToSum_C_X (c : S₂) : iterToSum R S₁ S₂ (C (X c)) = X (Sum.inr c) :=
Eq.trans (eval₂_C _ _ (X c)) (eval₂_X _ _ _)
set_option linter.uppercaseLean3 false in
#align mv_polynomial.iter_to_sum_C_X MvPolynomial.iterToSum_C_X
variable (σ)
@[simps!]
def isEmptyAlgEquiv [he : IsEmpty σ] : MvPolynomial σ R ≃ₐ[R] R :=
AlgEquiv.ofAlgHom (aeval (IsEmpty.elim he)) (Algebra.ofId _ _)
(by ext)
(by
ext i m
exact IsEmpty.elim' he i)
#align mv_polynomial.is_empty_alg_equiv MvPolynomial.isEmptyAlgEquiv
@[simps!]
def isEmptyRingEquiv [IsEmpty σ] : MvPolynomial σ R ≃+* R :=
(isEmptyAlgEquiv R σ).toRingEquiv
#align mv_polynomial.is_empty_ring_equiv MvPolynomial.isEmptyRingEquiv
variable {σ}
@[simps]
def mvPolynomialEquivMvPolynomial [CommSemiring S₃] (f : MvPolynomial S₁ R →+* MvPolynomial S₂ S₃)
(g : MvPolynomial S₂ S₃ →+* MvPolynomial S₁ R) (hfgC : (f.comp g).comp C = C)
(hfgX : ∀ n, f (g (X n)) = X n) (hgfC : (g.comp f).comp C = C) (hgfX : ∀ n, g (f (X n)) = X n) :
MvPolynomial S₁ R ≃+* MvPolynomial S₂ S₃ where
toFun := f
invFun := g
left_inv := is_id (RingHom.comp _ _) hgfC hgfX
right_inv := is_id (RingHom.comp _ _) hfgC hfgX
map_mul' := f.map_mul
map_add' := f.map_add
#align mv_polynomial.mv_polynomial_equiv_mv_polynomial MvPolynomial.mvPolynomialEquivMvPolynomial
def sumRingEquiv : MvPolynomial (Sum S₁ S₂) R ≃+* MvPolynomial S₁ (MvPolynomial S₂ R) := by
apply mvPolynomialEquivMvPolynomial R (Sum S₁ S₂) _ _ (sumToIter R S₁ S₂) (iterToSum R S₁ S₂)
· refine RingHom.ext (hom_eq_hom _ _ ?hC ?hX)
case hC => ext1; simp only [RingHom.comp_apply, iterToSum_C_C, sumToIter_C]
case hX => intro; simp only [RingHom.comp_apply, iterToSum_C_X, sumToIter_Xr]
· simp [iterToSum_X, sumToIter_Xl]
· ext1; simp only [RingHom.comp_apply, sumToIter_C, iterToSum_C_C]
· rintro ⟨⟩ <;> simp only [sumToIter_Xl, iterToSum_X, sumToIter_Xr, iterToSum_C_X]
#align mv_polynomial.sum_ring_equiv MvPolynomial.sumRingEquiv
@[simps!]
def sumAlgEquiv : MvPolynomial (Sum S₁ S₂) R ≃ₐ[R] MvPolynomial S₁ (MvPolynomial S₂ R) :=
{ sumRingEquiv R S₁ S₂ with
commutes' := by
intro r
have A : algebraMap R (MvPolynomial S₁ (MvPolynomial S₂ R)) r = (C (C r) : _) := rfl
have B : algebraMap R (MvPolynomial (Sum S₁ S₂) R) r = C r := rfl
simp only [sumRingEquiv, mvPolynomialEquivMvPolynomial, Equiv.toFun_as_coe,
Equiv.coe_fn_mk, B, sumToIter_C, A] }
#align mv_polynomial.sum_alg_equiv MvPolynomial.sumAlgEquiv
section
-- this speeds up typeclass search in the lemma below
attribute [local instance] IsScalarTower.right
@[simps!]
def optionEquivLeft : MvPolynomial (Option S₁) R ≃ₐ[R] Polynomial (MvPolynomial S₁ R) :=
AlgEquiv.ofAlgHom (MvPolynomial.aeval fun o => o.elim Polynomial.X fun s => Polynomial.C (X s))
(Polynomial.aevalTower (MvPolynomial.rename some) (X none))
(by ext : 2 <;> simp) (by ext i : 2; cases i <;> simp)
#align mv_polynomial.option_equiv_left MvPolynomial.optionEquivLeft
lemma optionEquivLeft_X_some (x : S₁) : optionEquivLeft R S₁ (X (some x)) = Polynomial.C (X x) := by
simp only [optionEquivLeft_apply, aeval_X]
lemma optionEquivLeft_X_none : optionEquivLeft R S₁ (X none) = Polynomial.X := by
simp only [optionEquivLeft_apply, aeval_X]
lemma optionEquivLeft_C (r : R) : optionEquivLeft R S₁ (C r) = Polynomial.C (C r) := by
simp only [optionEquivLeft_apply, aeval_C, Polynomial.algebraMap_apply, algebraMap_eq]
end
@[simps!]
def optionEquivRight : MvPolynomial (Option S₁) R ≃ₐ[R] MvPolynomial S₁ R[X] :=
AlgEquiv.ofAlgHom (MvPolynomial.aeval fun o => o.elim (C Polynomial.X) X)
(MvPolynomial.aevalTower (Polynomial.aeval (X none)) fun i => X (Option.some i))
(by
ext : 2 <;>
simp only [MvPolynomial.algebraMap_eq, Option.elim, AlgHom.coe_comp, AlgHom.id_comp,
IsScalarTower.coe_toAlgHom', comp_apply, aevalTower_C, Polynomial.aeval_X, aeval_X,
Option.elim', aevalTower_X, AlgHom.coe_id, id, eq_self_iff_true, imp_true_iff])
(by
ext ⟨i⟩ : 2 <;>
simp only [Option.elim, AlgHom.coe_comp, comp_apply, aeval_X, aevalTower_C,
Polynomial.aeval_X, AlgHom.coe_id, id, aevalTower_X])
#align mv_polynomial.option_equiv_right MvPolynomial.optionEquivRight
lemma optionEquivRight_X_some (x : S₁) : optionEquivRight R S₁ (X (some x)) = X x := by
simp only [optionEquivRight_apply, aeval_X]
lemma optionEquivRight_X_none : optionEquivRight R S₁ (X none) = C Polynomial.X := by
simp only [optionEquivRight_apply, aeval_X]
lemma optionEquivRight_C (r : R) : optionEquivRight R S₁ (C r) = C (Polynomial.C r) := by
simp only [optionEquivRight_apply, aeval_C, algebraMap_apply, Polynomial.algebraMap_eq]
variable (n : ℕ)
def finSuccEquiv : MvPolynomial (Fin (n + 1)) R ≃ₐ[R] Polynomial (MvPolynomial (Fin n) R) :=
(renameEquiv R (_root_.finSuccEquiv n)).trans (optionEquivLeft R (Fin n))
#align mv_polynomial.fin_succ_equiv MvPolynomial.finSuccEquiv
theorem finSuccEquiv_eq :
(finSuccEquiv R n : MvPolynomial (Fin (n + 1)) R →+* Polynomial (MvPolynomial (Fin n) R)) =
eval₂Hom (Polynomial.C.comp (C : R →+* MvPolynomial (Fin n) R)) fun i : Fin (n + 1) =>
Fin.cases Polynomial.X (fun k => Polynomial.C (X k)) i := by
ext i : 2
· simp only [finSuccEquiv, optionEquivLeft_apply, aeval_C, AlgEquiv.coe_trans, RingHom.coe_coe,
coe_eval₂Hom, comp_apply, renameEquiv_apply, eval₂_C, RingHom.coe_comp, rename_C]
rfl
· refine Fin.cases ?_ ?_ i <;> simp [finSuccEquiv]
#align mv_polynomial.fin_succ_equiv_eq MvPolynomial.finSuccEquiv_eq
@[simp]
theorem finSuccEquiv_apply (p : MvPolynomial (Fin (n + 1)) R) :
finSuccEquiv R n p =
eval₂Hom (Polynomial.C.comp (C : R →+* MvPolynomial (Fin n) R))
(fun i : Fin (n + 1) => Fin.cases Polynomial.X (fun k => Polynomial.C (X k)) i) p := by
rw [← finSuccEquiv_eq, RingHom.coe_coe]
#align mv_polynomial.fin_succ_equiv_apply MvPolynomial.finSuccEquiv_apply
theorem finSuccEquiv_comp_C_eq_C {R : Type u} [CommSemiring R] (n : ℕ) :
(↑(MvPolynomial.finSuccEquiv R n).symm : Polynomial (MvPolynomial (Fin n) R) →+* _).comp
(Polynomial.C.comp MvPolynomial.C) =
(MvPolynomial.C : R →+* MvPolynomial (Fin n.succ) R) := by
refine RingHom.ext fun x => ?_
rw [RingHom.comp_apply]
refine
(MvPolynomial.finSuccEquiv R n).injective
(Trans.trans ((MvPolynomial.finSuccEquiv R n).apply_symm_apply _) ?_)
simp only [MvPolynomial.finSuccEquiv_apply, MvPolynomial.eval₂Hom_C]
set_option linter.uppercaseLean3 false in
#align mv_polynomial.fin_succ_equiv_comp_C_eq_C MvPolynomial.finSuccEquiv_comp_C_eq_C
variable {n} {R}
theorem finSuccEquiv_X_zero : finSuccEquiv R n (X 0) = Polynomial.X := by simp
set_option linter.uppercaseLean3 false in
#align mv_polynomial.fin_succ_equiv_X_zero MvPolynomial.finSuccEquiv_X_zero
theorem finSuccEquiv_X_succ {j : Fin n} : finSuccEquiv R n (X j.succ) = Polynomial.C (X j) := by
simp
set_option linter.uppercaseLean3 false in
#align mv_polynomial.fin_succ_equiv_X_succ MvPolynomial.finSuccEquiv_X_succ
theorem finSuccEquiv_coeff_coeff (m : Fin n →₀ ℕ) (f : MvPolynomial (Fin (n + 1)) R) (i : ℕ) :
coeff m (Polynomial.coeff (finSuccEquiv R n f) i) = coeff (m.cons i) f := by
induction' f using MvPolynomial.induction_on' with j r p q hp hq generalizing i m
swap
· simp only [(finSuccEquiv R n).map_add, Polynomial.coeff_add, coeff_add, hp, hq]
simp only [finSuccEquiv_apply, coe_eval₂Hom, eval₂_monomial, RingHom.coe_comp, prod_pow,
Polynomial.coeff_C_mul, coeff_C_mul, coeff_monomial, Fin.prod_univ_succ, Fin.cases_zero,
Fin.cases_succ, ← map_prod, ← RingHom.map_pow, Function.comp_apply]
rw [← mul_boole, mul_comm (Polynomial.X ^ j 0), Polynomial.coeff_C_mul_X_pow]; congr 1
obtain rfl | hjmi := eq_or_ne j (m.cons i)
· simpa only [cons_zero, cons_succ, if_pos rfl, monomial_eq, C_1, one_mul, prod_pow] using
coeff_monomial m m (1 : R)
· simp only [hjmi, if_false]
obtain hij | rfl := ne_or_eq i (j 0)
· simp only [hij, if_false, coeff_zero]
simp only [eq_self_iff_true, if_true]
have hmj : m ≠ j.tail := by
rintro rfl
rw [cons_tail] at hjmi
contradiction
simpa only [monomial_eq, C_1, one_mul, prod_pow, Finsupp.tail_apply, if_neg hmj.symm] using
coeff_monomial m j.tail (1 : R)
#align mv_polynomial.fin_succ_equiv_coeff_coeff MvPolynomial.finSuccEquiv_coeff_coeff
theorem eval_eq_eval_mv_eval' (s : Fin n → R) (y : R) (f : MvPolynomial (Fin (n + 1)) R) :
eval (Fin.cons y s : Fin (n + 1) → R) f =
Polynomial.eval y (Polynomial.map (eval s) (finSuccEquiv R n f)) := by
-- turn this into a def `Polynomial.mapAlgHom`
let φ : (MvPolynomial (Fin n) R)[X] →ₐ[R] R[X] :=
{ Polynomial.mapRingHom (eval s) with
commutes' := fun r => by
convert Polynomial.map_C (eval s)
exact (eval_C _).symm }
show
aeval (Fin.cons y s : Fin (n + 1) → R) f =
(Polynomial.aeval y).comp (φ.comp (finSuccEquiv R n).toAlgHom) f
congr 2
apply MvPolynomial.algHom_ext
rw [Fin.forall_fin_succ]
simp only [φ, aeval_X, Fin.cons_zero, AlgEquiv.toAlgHom_eq_coe, AlgHom.coe_comp,
Polynomial.coe_aeval_eq_eval, Polynomial.map_C, AlgHom.coe_mk, RingHom.toFun_eq_coe,
Polynomial.coe_mapRingHom, comp_apply, finSuccEquiv_apply, eval₂Hom_X',
Fin.cases_zero, Polynomial.map_X, Polynomial.eval_X, Fin.cons_succ,
Fin.cases_succ, eval_X, Polynomial.eval_C,
RingHom.coe_mk, MonoidHom.coe_coe, AlgHom.coe_coe, implies_true, and_self,
RingHom.toMonoidHom_eq_coe]
#align mv_polynomial.eval_eq_eval_mv_eval' MvPolynomial.eval_eq_eval_mv_eval'
theorem coeff_eval_eq_eval_coeff (s' : Fin n → R) (f : Polynomial (MvPolynomial (Fin n) R))
(i : ℕ) : Polynomial.coeff (Polynomial.map (eval s') f) i = eval s' (Polynomial.coeff f i) := by
simp only [Polynomial.coeff_map]
#align mv_polynomial.coeff_eval_eq_eval_coeff MvPolynomial.coeff_eval_eq_eval_coeff
| Mathlib/Algebra/MvPolynomial/Equiv.lean | 437 | 443 | theorem support_coeff_finSuccEquiv {f : MvPolynomial (Fin (n + 1)) R} {i : ℕ} {m : Fin n →₀ ℕ} :
m ∈ (Polynomial.coeff ((finSuccEquiv R n) f) i).support ↔ Finsupp.cons i m ∈ f.support := by |
apply Iff.intro
· intro h
simpa [← finSuccEquiv_coeff_coeff] using h
· intro h
simpa [mem_support_iff, ← finSuccEquiv_coeff_coeff m f i] using h
|
import Mathlib.Algebra.Ring.Divisibility.Basic
import Mathlib.Init.Data.Ordering.Lemmas
import Mathlib.SetTheory.Ordinal.Principal
import Mathlib.Tactic.NormNum
#align_import set_theory.ordinal.notation from "leanprover-community/mathlib"@"b67044ba53af18680e1dd246861d9584e968495d"
set_option linter.uppercaseLean3 false
open Ordinal Order
-- Porting note: the generated theorem is warned by `simpNF`.
set_option genSizeOfSpec false in
inductive ONote : Type
| zero : ONote
| oadd : ONote → ℕ+ → ONote → ONote
deriving DecidableEq
#align onote ONote
compile_inductive% ONote
namespace ONote
instance : Zero ONote :=
⟨zero⟩
@[simp]
theorem zero_def : zero = 0 :=
rfl
#align onote.zero_def ONote.zero_def
instance : Inhabited ONote :=
⟨0⟩
instance : One ONote :=
⟨oadd 0 1 0⟩
def omega : ONote :=
oadd 1 1 0
#align onote.omega ONote.omega
@[simp]
noncomputable def repr : ONote → Ordinal.{0}
| 0 => 0
| oadd e n a => ω ^ repr e * n + repr a
#align onote.repr ONote.repr
def toStringAux1 (e : ONote) (n : ℕ) (s : String) : String :=
if e = 0 then toString n
else (if e = 1 then "ω" else "ω^(" ++ s ++ ")") ++ if n = 1 then "" else "*" ++ toString n
#align onote.to_string_aux1 ONote.toStringAux1
def toString : ONote → String
| zero => "0"
| oadd e n 0 => toStringAux1 e n (toString e)
| oadd e n a => toStringAux1 e n (toString e) ++ " + " ++ toString a
#align onote.to_string ONote.toString
open Lean in
def repr' (prec : ℕ) : ONote → Format
| zero => "0"
| oadd e n a =>
Repr.addAppParen
("oadd " ++ (repr' max_prec e) ++ " " ++ Nat.repr (n : ℕ) ++ " " ++ (repr' max_prec a))
prec
#align onote.repr' ONote.repr
instance : ToString ONote :=
⟨toString⟩
instance : Repr ONote where
reprPrec o prec := repr' prec o
instance : Preorder ONote where
le x y := repr x ≤ repr y
lt x y := repr x < repr y
le_refl _ := @le_refl Ordinal _ _
le_trans _ _ _ := @le_trans Ordinal _ _ _ _
lt_iff_le_not_le _ _ := @lt_iff_le_not_le Ordinal _ _ _
theorem lt_def {x y : ONote} : x < y ↔ repr x < repr y :=
Iff.rfl
#align onote.lt_def ONote.lt_def
theorem le_def {x y : ONote} : x ≤ y ↔ repr x ≤ repr y :=
Iff.rfl
#align onote.le_def ONote.le_def
instance : WellFoundedRelation ONote :=
⟨(· < ·), InvImage.wf repr Ordinal.lt_wf⟩
@[coe]
def ofNat : ℕ → ONote
| 0 => 0
| Nat.succ n => oadd 0 n.succPNat 0
#align onote.of_nat ONote.ofNat
-- Porting note (#11467): during the port we marked these lemmas with `@[eqns]`
-- to emulate the old Lean 3 behaviour.
@[simp] theorem ofNat_zero : ofNat 0 = 0 :=
rfl
@[simp] theorem ofNat_succ (n) : ofNat (Nat.succ n) = oadd 0 n.succPNat 0 :=
rfl
instance nat (n : ℕ) : OfNat ONote n where
ofNat := ofNat n
@[simp 1200]
theorem ofNat_one : ofNat 1 = 1 :=
rfl
#align onote.of_nat_one ONote.ofNat_one
@[simp]
theorem repr_ofNat (n : ℕ) : repr (ofNat n) = n := by cases n <;> simp
#align onote.repr_of_nat ONote.repr_ofNat
-- @[simp] -- Porting note (#10618): simp can prove this
theorem repr_one : repr (ofNat 1) = (1 : ℕ) := repr_ofNat 1
#align onote.repr_one ONote.repr_one
theorem omega_le_oadd (e n a) : ω ^ repr e ≤ repr (oadd e n a) := by
refine le_trans ?_ (le_add_right _ _)
simpa using (Ordinal.mul_le_mul_iff_left <| opow_pos (repr e) omega_pos).2 (natCast_le.2 n.2)
#align onote.omega_le_oadd ONote.omega_le_oadd
theorem oadd_pos (e n a) : 0 < oadd e n a :=
@lt_of_lt_of_le _ _ _ (ω ^ repr e) _ (opow_pos (repr e) omega_pos) (omega_le_oadd e n a)
#align onote.oadd_pos ONote.oadd_pos
def cmp : ONote → ONote → Ordering
| 0, 0 => Ordering.eq
| _, 0 => Ordering.gt
| 0, _ => Ordering.lt
| _o₁@(oadd e₁ n₁ a₁), _o₂@(oadd e₂ n₂ a₂) =>
(cmp e₁ e₂).orElse <| (_root_.cmp (n₁ : ℕ) n₂).orElse (cmp a₁ a₂)
#align onote.cmp ONote.cmp
theorem eq_of_cmp_eq : ∀ {o₁ o₂}, cmp o₁ o₂ = Ordering.eq → o₁ = o₂
| 0, 0, _ => rfl
| oadd e n a, 0, h => by injection h
| 0, oadd e n a, h => by injection h
| oadd e₁ n₁ a₁, oadd e₂ n₂ a₂, h => by
revert h; simp only [cmp]
cases h₁ : cmp e₁ e₂ <;> intro h <;> try cases h
obtain rfl := eq_of_cmp_eq h₁
revert h; cases h₂ : _root_.cmp (n₁ : ℕ) n₂ <;> intro h <;> try cases h
obtain rfl := eq_of_cmp_eq h
rw [_root_.cmp, cmpUsing_eq_eq] at h₂
obtain rfl := Subtype.eq (eq_of_incomp h₂)
simp
#align onote.eq_of_cmp_eq ONote.eq_of_cmp_eq
protected theorem zero_lt_one : (0 : ONote) < 1 := by
simp only [lt_def, repr, opow_zero, Nat.succPNat_coe, Nat.cast_one, mul_one, add_zero,
zero_lt_one]
#align onote.zero_lt_one ONote.zero_lt_one
inductive NFBelow : ONote → Ordinal.{0} → Prop
| zero {b} : NFBelow 0 b
| oadd' {e n a eb b} : NFBelow e eb → NFBelow a (repr e) → repr e < b → NFBelow (oadd e n a) b
#align onote.NF_below ONote.NFBelow
class NF (o : ONote) : Prop where
out : Exists (NFBelow o)
#align onote.NF ONote.NF
instance NF.zero : NF 0 :=
⟨⟨0, NFBelow.zero⟩⟩
#align onote.NF.zero ONote.NF.zero
theorem NFBelow.oadd {e n a b} : NF e → NFBelow a (repr e) → repr e < b → NFBelow (oadd e n a) b
| ⟨⟨_, h⟩⟩ => NFBelow.oadd' h
#align onote.NF_below.oadd ONote.NFBelow.oadd
theorem NFBelow.fst {e n a b} (h : NFBelow (ONote.oadd e n a) b) : NF e := by
cases' h with _ _ _ _ eb _ h₁ h₂ h₃; exact ⟨⟨_, h₁⟩⟩
#align onote.NF_below.fst ONote.NFBelow.fst
theorem NF.fst {e n a} : NF (oadd e n a) → NF e
| ⟨⟨_, h⟩⟩ => h.fst
#align onote.NF.fst ONote.NF.fst
theorem NFBelow.snd {e n a b} (h : NFBelow (ONote.oadd e n a) b) : NFBelow a (repr e) := by
cases' h with _ _ _ _ eb _ h₁ h₂ h₃; exact h₂
#align onote.NF_below.snd ONote.NFBelow.snd
theorem NF.snd' {e n a} : NF (oadd e n a) → NFBelow a (repr e)
| ⟨⟨_, h⟩⟩ => h.snd
#align onote.NF.snd' ONote.NF.snd'
theorem NF.snd {e n a} (h : NF (oadd e n a)) : NF a :=
⟨⟨_, h.snd'⟩⟩
#align onote.NF.snd ONote.NF.snd
theorem NF.oadd {e a} (h₁ : NF e) (n) (h₂ : NFBelow a (repr e)) : NF (oadd e n a) :=
⟨⟨_, NFBelow.oadd h₁ h₂ (lt_succ _)⟩⟩
#align onote.NF.oadd ONote.NF.oadd
instance NF.oadd_zero (e n) [h : NF e] : NF (ONote.oadd e n 0) :=
h.oadd _ NFBelow.zero
#align onote.NF.oadd_zero ONote.NF.oadd_zero
theorem NFBelow.lt {e n a b} (h : NFBelow (ONote.oadd e n a) b) : repr e < b := by
cases' h with _ _ _ _ eb _ h₁ h₂ h₃; exact h₃
#align onote.NF_below.lt ONote.NFBelow.lt
theorem NFBelow_zero : ∀ {o}, NFBelow o 0 ↔ o = 0
| 0 => ⟨fun _ => rfl, fun _ => NFBelow.zero⟩
| oadd _ _ _ =>
⟨fun h => (not_le_of_lt h.lt).elim (Ordinal.zero_le _), fun e => e.symm ▸ NFBelow.zero⟩
#align onote.NF_below_zero ONote.NFBelow_zero
theorem NF.zero_of_zero {e n a} (h : NF (ONote.oadd e n a)) (e0 : e = 0) : a = 0 := by
simpa [e0, NFBelow_zero] using h.snd'
#align onote.NF.zero_of_zero ONote.NF.zero_of_zero
theorem NFBelow.repr_lt {o b} (h : NFBelow o b) : repr o < ω ^ b := by
induction' h with _ e n a eb b h₁ h₂ h₃ _ IH
· exact opow_pos _ omega_pos
· rw [repr]
apply ((add_lt_add_iff_left _).2 IH).trans_le
rw [← mul_succ]
apply (mul_le_mul_left' (succ_le_of_lt (nat_lt_omega _)) _).trans
rw [← opow_succ]
exact opow_le_opow_right omega_pos (succ_le_of_lt h₃)
#align onote.NF_below.repr_lt ONote.NFBelow.repr_lt
theorem NFBelow.mono {o b₁ b₂} (bb : b₁ ≤ b₂) (h : NFBelow o b₁) : NFBelow o b₂ := by
induction' h with _ e n a eb b h₁ h₂ h₃ _ _ <;> constructor
exacts [h₁, h₂, lt_of_lt_of_le h₃ bb]
#align onote.NF_below.mono ONote.NFBelow.mono
theorem NF.below_of_lt {e n a b} (H : repr e < b) :
NF (ONote.oadd e n a) → NFBelow (ONote.oadd e n a) b
| ⟨⟨b', h⟩⟩ => by (cases' h with _ _ _ _ eb _ h₁ h₂ h₃; exact NFBelow.oadd' h₁ h₂ H)
#align onote.NF.below_of_lt ONote.NF.below_of_lt
theorem NF.below_of_lt' : ∀ {o b}, repr o < ω ^ b → NF o → NFBelow o b
| 0, _, _, _ => NFBelow.zero
| ONote.oadd _ _ _, _, H, h =>
h.below_of_lt <|
(opow_lt_opow_iff_right one_lt_omega).1 <| lt_of_le_of_lt (omega_le_oadd _ _ _) H
#align onote.NF.below_of_lt' ONote.NF.below_of_lt'
theorem nfBelow_ofNat : ∀ n, NFBelow (ofNat n) 1
| 0 => NFBelow.zero
| Nat.succ _ => NFBelow.oadd NF.zero NFBelow.zero zero_lt_one
#align onote.NF_below_of_nat ONote.nfBelow_ofNat
instance nf_ofNat (n) : NF (ofNat n) :=
⟨⟨_, nfBelow_ofNat n⟩⟩
#align onote.NF_of_nat ONote.nf_ofNat
instance nf_one : NF 1 := by rw [← ofNat_one]; infer_instance
#align onote.NF_one ONote.nf_one
theorem oadd_lt_oadd_1 {e₁ n₁ o₁ e₂ n₂ o₂} (h₁ : NF (oadd e₁ n₁ o₁)) (h : e₁ < e₂) :
oadd e₁ n₁ o₁ < oadd e₂ n₂ o₂ :=
@lt_of_lt_of_le _ _ (repr (oadd e₁ n₁ o₁)) _ _
(NF.below_of_lt h h₁).repr_lt (omega_le_oadd e₂ n₂ o₂)
#align onote.oadd_lt_oadd_1 ONote.oadd_lt_oadd_1
theorem oadd_lt_oadd_2 {e o₁ o₂ : ONote} {n₁ n₂ : ℕ+} (h₁ : NF (oadd e n₁ o₁)) (h : (n₁ : ℕ) < n₂) :
oadd e n₁ o₁ < oadd e n₂ o₂ := by
simp only [lt_def, repr]
refine lt_of_lt_of_le ((add_lt_add_iff_left _).2 h₁.snd'.repr_lt) (le_trans ?_ (le_add_right _ _))
rwa [← mul_succ,Ordinal.mul_le_mul_iff_left (opow_pos _ omega_pos), succ_le_iff, natCast_lt]
#align onote.oadd_lt_oadd_2 ONote.oadd_lt_oadd_2
theorem oadd_lt_oadd_3 {e n a₁ a₂} (h : a₁ < a₂) : oadd e n a₁ < oadd e n a₂ := by
rw [lt_def]; unfold repr
exact @add_lt_add_left _ _ _ _ (repr a₁) _ h _
#align onote.oadd_lt_oadd_3 ONote.oadd_lt_oadd_3
theorem cmp_compares : ∀ (a b : ONote) [NF a] [NF b], (cmp a b).Compares a b
| 0, 0, _, _ => rfl
| oadd e n a, 0, _, _ => oadd_pos _ _ _
| 0, oadd e n a, _, _ => oadd_pos _ _ _
| o₁@(oadd e₁ n₁ a₁), o₂@(oadd e₂ n₂ a₂), h₁, h₂ => by -- TODO: golf
rw [cmp]
have IHe := @cmp_compares _ _ h₁.fst h₂.fst
simp only [Ordering.Compares, gt_iff_lt] at IHe; revert IHe
cases cmp e₁ e₂
case lt => intro IHe; exact oadd_lt_oadd_1 h₁ IHe
case gt => intro IHe; exact oadd_lt_oadd_1 h₂ IHe
case eq =>
intro IHe; dsimp at IHe; subst IHe
unfold _root_.cmp; cases nh : cmpUsing (· < ·) (n₁ : ℕ) n₂ <;>
rw [cmpUsing, ite_eq_iff, not_lt] at nh
case lt =>
cases' nh with nh nh
· exact oadd_lt_oadd_2 h₁ nh.left
· rw [ite_eq_iff] at nh; cases' nh.right with nh nh <;> cases nh <;> contradiction
case gt =>
cases' nh with nh nh
· cases nh; contradiction
· cases' nh with _ nh
rw [ite_eq_iff] at nh; cases' nh with nh nh
· exact oadd_lt_oadd_2 h₂ nh.left
· cases nh; contradiction
cases' nh with nh nh
· cases nh; contradiction
cases' nh with nhl nhr
rw [ite_eq_iff] at nhr
cases' nhr with nhr nhr
· cases nhr; contradiction
obtain rfl := Subtype.eq (eq_of_incomp ⟨(not_lt_of_ge nhl), nhr.left⟩)
have IHa := @cmp_compares _ _ h₁.snd h₂.snd
revert IHa; cases cmp a₁ a₂ <;> intro IHa <;> dsimp at IHa
case lt => exact oadd_lt_oadd_3 IHa
case gt => exact oadd_lt_oadd_3 IHa
subst IHa; exact rfl
#align onote.cmp_compares ONote.cmp_compares
theorem repr_inj {a b} [NF a] [NF b] : repr a = repr b ↔ a = b :=
⟨fun e => match cmp a b, cmp_compares a b with
| Ordering.lt, (h : repr a < repr b) => (ne_of_lt h e).elim
| Ordering.gt, (h : repr a > repr b)=> (ne_of_gt h e).elim
| Ordering.eq, h => h,
congr_arg _⟩
#align onote.repr_inj ONote.repr_inj
theorem NF.of_dvd_omega_opow {b e n a} (h : NF (ONote.oadd e n a))
(d : ω ^ b ∣ repr (ONote.oadd e n a)) :
b ≤ repr e ∧ ω ^ b ∣ repr a := by
have := mt repr_inj.1 (fun h => by injection h : ONote.oadd e n a ≠ 0)
have L := le_of_not_lt fun l => not_le_of_lt (h.below_of_lt l).repr_lt (le_of_dvd this d)
simp only [repr] at d
exact ⟨L, (dvd_add_iff <| (opow_dvd_opow _ L).mul_right _).1 d⟩
#align onote.NF.of_dvd_omega_opow ONote.NF.of_dvd_omega_opow
theorem NF.of_dvd_omega {e n a} (h : NF (ONote.oadd e n a)) :
ω ∣ repr (ONote.oadd e n a) → repr e ≠ 0 ∧ ω ∣ repr a := by
(rw [← opow_one ω, ← one_le_iff_ne_zero]; exact h.of_dvd_omega_opow)
#align onote.NF.of_dvd_omega ONote.NF.of_dvd_omega
def TopBelow (b : ONote) : ONote → Prop
| 0 => True
| oadd e _ _ => cmp e b = Ordering.lt
#align onote.top_below ONote.TopBelow
instance decidableTopBelow : DecidableRel TopBelow := by
intro b o
cases o <;> delta TopBelow <;> infer_instance
#align onote.decidable_top_below ONote.decidableTopBelow
theorem nfBelow_iff_topBelow {b} [NF b] : ∀ {o}, NFBelow o (repr b) ↔ NF o ∧ TopBelow b o
| 0 => ⟨fun h => ⟨⟨⟨_, h⟩⟩, trivial⟩, fun _ => NFBelow.zero⟩
| oadd _ _ _ =>
⟨fun h => ⟨⟨⟨_, h⟩⟩, (@cmp_compares _ b h.fst _).eq_lt.2 h.lt⟩, fun ⟨h₁, h₂⟩ =>
h₁.below_of_lt <| (@cmp_compares _ b h₁.fst _).eq_lt.1 h₂⟩
#align onote.NF_below_iff_top_below ONote.nfBelow_iff_topBelow
instance decidableNF : DecidablePred NF
| 0 => isTrue NF.zero
| oadd e n a => by
have := decidableNF e
have := decidableNF a
apply decidable_of_iff (NF e ∧ NF a ∧ TopBelow e a)
rw [← and_congr_right fun h => @nfBelow_iff_topBelow _ h _]
exact ⟨fun ⟨h₁, h₂⟩ => NF.oadd h₁ n h₂, fun h => ⟨h.fst, h.snd'⟩⟩
#align onote.decidable_NF ONote.decidableNF
def addAux (e : ONote) (n : ℕ+) (o : ONote) : ONote :=
match o with
| 0 => oadd e n 0
| o'@(oadd e' n' a') =>
match cmp e e' with
| Ordering.lt => o'
| Ordering.eq => oadd e (n + n') a'
| Ordering.gt => oadd e n o'
def add : ONote → ONote → ONote
| 0, o => o
| oadd e n a, o => addAux e n (add a o)
#align onote.add ONote.add
instance : Add ONote :=
⟨add⟩
@[simp]
theorem zero_add (o : ONote) : 0 + o = o :=
rfl
#align onote.zero_add ONote.zero_add
theorem oadd_add (e n a o) : oadd e n a + o = addAux e n (a + o) :=
rfl
#align onote.oadd_add ONote.oadd_add
def sub : ONote → ONote → ONote
| 0, _ => 0
| o, 0 => o
| o₁@(oadd e₁ n₁ a₁), oadd e₂ n₂ a₂ =>
match cmp e₁ e₂ with
| Ordering.lt => 0
| Ordering.gt => o₁
| Ordering.eq =>
match (n₁ : ℕ) - n₂ with
| 0 => if n₁ = n₂ then sub a₁ a₂ else 0
| Nat.succ k => oadd e₁ k.succPNat a₁
#align onote.sub ONote.sub
instance : Sub ONote :=
⟨sub⟩
theorem add_nfBelow {b} : ∀ {o₁ o₂}, NFBelow o₁ b → NFBelow o₂ b → NFBelow (o₁ + o₂) b
| 0, _, _, h₂ => h₂
| oadd e n a, o, h₁, h₂ => by
have h' := add_nfBelow (h₁.snd.mono <| le_of_lt h₁.lt) h₂
simp [oadd_add]; revert h'; cases' a + o with e' n' a' <;> intro h'
· exact NFBelow.oadd h₁.fst NFBelow.zero h₁.lt
have : ((e.cmp e').Compares e e') := @cmp_compares _ _ h₁.fst h'.fst
cases h: cmp e e' <;> dsimp [addAux] <;> simp [h]
· exact h'
· simp [h] at this
subst e'
exact NFBelow.oadd h'.fst h'.snd h'.lt
· simp [h] at this
exact NFBelow.oadd h₁.fst (NF.below_of_lt this ⟨⟨_, h'⟩⟩) h₁.lt
#align onote.add_NF_below ONote.add_nfBelow
instance add_nf (o₁ o₂) : ∀ [NF o₁] [NF o₂], NF (o₁ + o₂)
| ⟨⟨b₁, h₁⟩⟩, ⟨⟨b₂, h₂⟩⟩ =>
⟨(le_total b₁ b₂).elim (fun h => ⟨b₂, add_nfBelow (h₁.mono h) h₂⟩) fun h =>
⟨b₁, add_nfBelow h₁ (h₂.mono h)⟩⟩
#align onote.add_NF ONote.add_nf
@[simp]
theorem repr_add : ∀ (o₁ o₂) [NF o₁] [NF o₂], repr (o₁ + o₂) = repr o₁ + repr o₂
| 0, o, _, _ => by simp
| oadd e n a, o, h₁, h₂ => by
haveI := h₁.snd; have h' := repr_add a o
conv_lhs at h' => simp [HAdd.hAdd, Add.add]
have nf := ONote.add_nf a o
conv at nf => simp [HAdd.hAdd, Add.add]
conv in _ + o => simp [HAdd.hAdd, Add.add]
cases' h : add a o with e' n' a' <;>
simp only [Add.add, add, addAux, h'.symm, h, add_assoc, repr] at nf h₁ ⊢
have := h₁.fst; haveI := nf.fst; have ee := cmp_compares e e'
cases he: cmp e e' <;> simp only [he, Ordering.compares_gt, Ordering.compares_lt,
Ordering.compares_eq, repr, gt_iff_lt, PNat.add_coe, Nat.cast_add] at ee ⊢
· rw [← add_assoc, @add_absorp _ (repr e') (ω ^ repr e' * (n' : ℕ))]
· have := (h₁.below_of_lt ee).repr_lt
unfold repr at this
cases he': e' <;> simp only [he', zero_def, opow_zero, repr, gt_iff_lt] at this ⊢ <;>
exact lt_of_le_of_lt (le_add_right _ _) this
· simpa using (Ordinal.mul_le_mul_iff_left <| opow_pos (repr e') omega_pos).2
(natCast_le.2 n'.pos)
· rw [ee, ← add_assoc, ← mul_add]
#align onote.repr_add ONote.repr_add
theorem sub_nfBelow : ∀ {o₁ o₂ b}, NFBelow o₁ b → NF o₂ → NFBelow (o₁ - o₂) b
| 0, o, b, _, h₂ => by cases o <;> exact NFBelow.zero
| oadd _ _ _, 0, _, h₁, _ => h₁
| oadd e₁ n₁ a₁, oadd e₂ n₂ a₂, b, h₁, h₂ => by
have h' := sub_nfBelow h₁.snd h₂.snd
simp only [HSub.hSub, Sub.sub, sub] at h' ⊢
have := @cmp_compares _ _ h₁.fst h₂.fst
cases h : cmp e₁ e₂ <;> simp [sub]
· apply NFBelow.zero
· simp only [h, Ordering.compares_eq] at this
subst e₂
cases (n₁ : ℕ) - n₂ <;> simp [sub]
· by_cases en : n₁ = n₂ <;> simp [en]
· exact h'.mono (le_of_lt h₁.lt)
· exact NFBelow.zero
· exact NFBelow.oadd h₁.fst h₁.snd h₁.lt
· exact h₁
#align onote.sub_NF_below ONote.sub_nfBelow
instance sub_nf (o₁ o₂) : ∀ [NF o₁] [NF o₂], NF (o₁ - o₂)
| ⟨⟨b₁, h₁⟩⟩, h₂ => ⟨⟨b₁, sub_nfBelow h₁ h₂⟩⟩
#align onote.sub_NF ONote.sub_nf
@[simp]
theorem repr_sub : ∀ (o₁ o₂) [NF o₁] [NF o₂], repr (o₁ - o₂) = repr o₁ - repr o₂
| 0, o, _, h₂ => by cases o <;> exact (Ordinal.zero_sub _).symm
| oadd e n a, 0, _, _ => (Ordinal.sub_zero _).symm
| oadd e₁ n₁ a₁, oadd e₂ n₂ a₂, h₁, h₂ => by
haveI := h₁.snd; haveI := h₂.snd; have h' := repr_sub a₁ a₂
conv_lhs at h' => dsimp [HSub.hSub, Sub.sub, sub]
conv_lhs => dsimp only [HSub.hSub, Sub.sub]; dsimp only [sub]
have ee := @cmp_compares _ _ h₁.fst h₂.fst
cases h : cmp e₁ e₂ <;> simp only [h] at ee
· rw [Ordinal.sub_eq_zero_iff_le.2]
· rfl
exact le_of_lt (oadd_lt_oadd_1 h₁ ee)
· change e₁ = e₂ at ee
subst e₂
dsimp only
cases mn : (n₁ : ℕ) - n₂ <;> dsimp only
· by_cases en : n₁ = n₂
· simpa [en]
· simp only [en, ite_false]
exact
(Ordinal.sub_eq_zero_iff_le.2 <|
le_of_lt <|
oadd_lt_oadd_2 h₁ <|
lt_of_le_of_ne (tsub_eq_zero_iff_le.1 mn) (mt PNat.eq en)).symm
· simp [Nat.succPNat]
rw [(tsub_eq_iff_eq_add_of_le <| le_of_lt <| Nat.lt_of_sub_eq_succ mn).1 mn, add_comm,
Nat.cast_add, mul_add, add_assoc, add_sub_add_cancel]
refine
(Ordinal.sub_eq_of_add_eq <|
add_absorp h₂.snd'.repr_lt <| le_trans ?_ (le_add_right _ _)).symm
simpa using mul_le_mul_left' (natCast_le.2 <| Nat.succ_pos _) _
· exact
(Ordinal.sub_eq_of_add_eq <|
add_absorp (h₂.below_of_lt ee).repr_lt <| omega_le_oadd _ _ _).symm
#align onote.repr_sub ONote.repr_sub
def mul : ONote → ONote → ONote
| 0, _ => 0
| _, 0 => 0
| o₁@(oadd e₁ n₁ a₁), oadd e₂ n₂ a₂ =>
if e₂ = 0 then oadd e₁ (n₁ * n₂) a₁ else oadd (e₁ + e₂) n₂ (mul o₁ a₂)
#align onote.mul ONote.mul
instance : Mul ONote :=
⟨mul⟩
instance : MulZeroClass ONote where
mul := (· * ·)
zero := 0
zero_mul o := by cases o <;> rfl
mul_zero o := by cases o <;> rfl
theorem oadd_mul (e₁ n₁ a₁ e₂ n₂ a₂) :
oadd e₁ n₁ a₁ * oadd e₂ n₂ a₂ =
if e₂ = 0 then oadd e₁ (n₁ * n₂) a₁ else oadd (e₁ + e₂) n₂ (oadd e₁ n₁ a₁ * a₂) :=
rfl
#align onote.oadd_mul ONote.oadd_mul
theorem oadd_mul_nfBelow {e₁ n₁ a₁ b₁} (h₁ : NFBelow (oadd e₁ n₁ a₁) b₁) :
∀ {o₂ b₂}, NFBelow o₂ b₂ → NFBelow (oadd e₁ n₁ a₁ * o₂) (repr e₁ + b₂)
| 0, b₂, _ => NFBelow.zero
| oadd e₂ n₂ a₂, b₂, h₂ => by
have IH := oadd_mul_nfBelow h₁ h₂.snd
by_cases e0 : e₂ = 0 <;> simp [e0, oadd_mul]
· apply NFBelow.oadd h₁.fst h₁.snd
simpa using (add_lt_add_iff_left (repr e₁)).2 (lt_of_le_of_lt (Ordinal.zero_le _) h₂.lt)
· haveI := h₁.fst
haveI := h₂.fst
apply NFBelow.oadd
· infer_instance
· rwa [repr_add]
· rw [repr_add, add_lt_add_iff_left]
exact h₂.lt
#align onote.oadd_mul_NF_below ONote.oadd_mul_nfBelow
instance mul_nf : ∀ (o₁ o₂) [NF o₁] [NF o₂], NF (o₁ * o₂)
| 0, o, _, h₂ => by cases o <;> exact NF.zero
| oadd e n a, o, ⟨⟨b₁, hb₁⟩⟩, ⟨⟨b₂, hb₂⟩⟩ => ⟨⟨_, oadd_mul_nfBelow hb₁ hb₂⟩⟩
#align onote.mul_NF ONote.mul_nf
@[simp]
| Mathlib/SetTheory/Ordinal/Notation.lean | 613 | 636 | theorem repr_mul : ∀ (o₁ o₂) [NF o₁] [NF o₂], repr (o₁ * o₂) = repr o₁ * repr o₂
| 0, o, _, h₂ => by cases o <;> exact (zero_mul _).symm
| oadd e₁ n₁ a₁, 0, _, _ => (mul_zero _).symm
| oadd e₁ n₁ a₁, oadd e₂ n₂ a₂, h₁, h₂ => by
have IH : repr (mul _ _) = _ := @repr_mul _ _ h₁ h₂.snd
conv =>
lhs
simp [(· * ·)]
have ao : repr a₁ + ω ^ repr e₁ * (n₁ : ℕ) = ω ^ repr e₁ * (n₁ : ℕ) := by |
apply add_absorp h₁.snd'.repr_lt
simpa using (Ordinal.mul_le_mul_iff_left <| opow_pos _ omega_pos).2 (natCast_le.2 n₁.2)
by_cases e0 : e₂ = 0 <;> simp [e0, mul]
· cases' Nat.exists_eq_succ_of_ne_zero n₂.ne_zero with x xe
simp only [xe, h₂.zero_of_zero e0, repr, add_zero]
rw [natCast_succ x, add_mul_succ _ ao, mul_assoc]
· haveI := h₁.fst
haveI := h₂.fst
simp only [Mul.mul, mul, e0, ite_false, repr.eq_2, repr_add, opow_add, IH, repr, mul_add]
rw [← mul_assoc]
congr 2
have := mt repr_inj.1 e0
rw [add_mul_limit ao (opow_isLimit_left omega_isLimit this), mul_assoc,
mul_omega_dvd (natCast_pos.2 n₁.pos) (nat_lt_omega _)]
simpa using opow_dvd_opow ω (one_le_iff_ne_zero.2 this)
|
import Mathlib.Order.Filter.Cofinite
import Mathlib.Order.Filter.CountableInter
import Mathlib.Order.Filter.CardinalInter
import Mathlib.SetTheory.Cardinal.Ordinal
import Mathlib.SetTheory.Cardinal.Cofinality
import Mathlib.Order.Filter.Bases
open Set Filter Cardinal
universe u
variable {ι : Type u} {α β : Type u}
variable {c : Cardinal.{u}} {hreg : c.IsRegular}
variable {l : Filter α}
namespace Filter
variable (α) in
def cocardinal (hreg : c.IsRegular) : Filter α := by
apply ofCardinalUnion {s | Cardinal.mk s < c} (lt_of_lt_of_le (nat_lt_aleph0 2) hreg.aleph0_le)
· refine fun s hS hSc ↦ lt_of_le_of_lt (mk_sUnion_le _) <| mul_lt_of_lt hreg.aleph0_le hS ?_
exact iSup_lt_of_isRegular hreg hS fun i ↦ hSc i i.property
· exact fun _ hSc _ ht ↦ lt_of_le_of_lt (mk_le_mk_of_subset ht) hSc
@[simp]
theorem mem_cocardinal {s : Set α} :
s ∈ cocardinal α hreg ↔ Cardinal.mk (sᶜ : Set α) < c := Iff.rfl
@[simp] lemma cocardinal_aleph0_eq_cofinite :
cocardinal (α := α) isRegular_aleph0 = cofinite := by
aesop
instance instCardinalInterFilter_cocardinal : CardinalInterFilter (cocardinal (α := α) hreg) c where
cardinal_sInter_mem S hS hSs := by
rw [mem_cocardinal, Set.compl_sInter]
apply lt_of_le_of_lt (mk_sUnion_le _)
apply mul_lt_of_lt hreg.aleph0_le (lt_of_le_of_lt mk_image_le hS)
apply iSup_lt_of_isRegular hreg <| lt_of_le_of_lt mk_image_le hS
intro i
aesop
@[simp]
theorem eventually_cocardinal {p : α → Prop} :
(∀ᶠ x in cocardinal α hreg, p x) ↔ #{ x | ¬p x } < c := Iff.rfl
theorem hasBasis_cocardinal : HasBasis (cocardinal α hreg) {s : Set α | #s < c} compl :=
⟨fun s =>
⟨fun h => ⟨sᶜ, h, (compl_compl s).subset⟩, fun ⟨_t, htf, hts⟩ => by
have : #↑sᶜ < c := by
apply lt_of_le_of_lt _ htf
rw [compl_subset_comm] at hts
apply Cardinal.mk_le_mk_of_subset hts
simp_all only [mem_cocardinal] ⟩⟩
theorem frequently_cocardinal {p : α → Prop} :
(∃ᶠ x in cocardinal α hreg, p x) ↔ c ≤ # { x | p x } := by
simp only [Filter.Frequently, eventually_cocardinal, not_not,coe_setOf, not_lt]
lemma frequently_cocardinal_mem {s : Set α} :
(∃ᶠ x in cocardinal α hreg, x ∈ s) ↔ c ≤ #s := frequently_cocardinal
@[simp]
lemma cocardinal_inf_principal_neBot_iff {s : Set α} :
(cocardinal α hreg ⊓ 𝓟 s).NeBot ↔ c ≤ #s :=
frequently_mem_iff_neBot.symm.trans frequently_cocardinal
theorem compl_mem_cocardinal_of_card_lt {s : Set α} (hs : #s < c) :
sᶜ ∈ cocardinal α hreg :=
mem_cocardinal.2 <| (compl_compl s).symm ▸ hs
theorem _root_.Set.Finite.compl_mem_cocardinal {s : Set α} (hs : s.Finite) :
sᶜ ∈ cocardinal α hreg :=
compl_mem_cocardinal_of_card_lt <| lt_of_lt_of_le (Finite.lt_aleph0 hs) (hreg.aleph0_le)
theorem eventually_cocardinal_nmem_of_card_lt {s : Set α} (hs : #s < c) :
∀ᶠ x in cocardinal α hreg, x ∉ s :=
compl_mem_cocardinal_of_card_lt hs
theorem _root_.Finset.eventually_cocardinal_nmem (s : Finset α) :
∀ᶠ x in cocardinal α hreg, x ∉ s :=
eventually_cocardinal_nmem_of_card_lt <| lt_of_lt_of_le (finset_card_lt_aleph0 s) (hreg.aleph0_le)
theorem eventually_cocardinal_ne (x : α) : ∀ᶠ a in cocardinal α hreg, a ≠ x := by
simp [Set.finite_singleton x]
exact hreg.nat_lt 1
abbrev cocountable : Filter α := cocardinal α Cardinal.isRegular_aleph_one
| Mathlib/Order/Filter/Cocardinal.lean | 105 | 107 | theorem mem_cocountable {s : Set α} :
s ∈ cocountable ↔ (sᶜ : Set α).Countable := by |
rw [Cardinal.countable_iff_lt_aleph_one, mem_cocardinal]
|
import Mathlib.Order.Filter.Germ
import Mathlib.Topology.NhdsSet
import Mathlib.Topology.LocallyConstant.Basic
import Mathlib.Analysis.NormedSpace.Basic
variable {F G : Type*} [NormedAddCommGroup F] [NormedSpace ℝ F]
[NormedAddCommGroup G] [NormedSpace ℝ G]
open scoped Topology
open Filter Set
variable {X Y Z : Type*} [TopologicalSpace X] {f g : X → Y} {A : Set X} {x : X}
section RestrictGermPredicate
def RestrictGermPredicate (P : ∀ x : X, Germ (𝓝 x) Y → Prop)
(A : Set X) : ∀ x : X, Germ (𝓝 x) Y → Prop := fun x φ ↦
Germ.liftOn φ (fun f ↦ x ∈ A → ∀ᶠ y in 𝓝 x, P y f)
haveI : ∀ f f' : X → Y, f =ᶠ[𝓝 x] f' → (∀ᶠ y in 𝓝 x, P y f) → ∀ᶠ y in 𝓝 x, P y f' := by
intro f f' hff' hf
apply (hf.and <| Eventually.eventually_nhds hff').mono
rintro y ⟨hy, hy'⟩
rwa [Germ.coe_eq.mpr (EventuallyEq.symm hy')]
fun f f' hff' ↦ propext <| forall_congr' fun _ ↦ ⟨this f f' hff', this f' f hff'.symm⟩
theorem Filter.Eventually.germ_congr_set
{P : ∀ x : X, Germ (𝓝 x) Y → Prop} (hf : ∀ᶠ x in 𝓝ˢ A, P x f)
(h : ∀ᶠ z in 𝓝ˢ A, g z = f z) : ∀ᶠ x in 𝓝ˢ A, P x g := by
rw [eventually_nhdsSet_iff_forall] at *
intro x hx
apply ((hf x hx).and (h x hx).eventually_nhds).mono
intro y hy
convert hy.1 using 1
exact Germ.coe_eq.mpr hy.2
| Mathlib/Topology/Germ.lean | 104 | 110 | theorem restrictGermPredicate_congr {P : ∀ x : X, Germ (𝓝 x) Y → Prop}
(hf : RestrictGermPredicate P A x f) (h : ∀ᶠ z in 𝓝ˢ A, g z = f z) :
RestrictGermPredicate P A x g := by |
intro hx
apply ((hf hx).and <| (eventually_nhdsSet_iff_forall.mp h x hx).eventually_nhds).mono
rintro y ⟨hy, h'y⟩
rwa [Germ.coe_eq.mpr h'y]
|
import Mathlib.Data.Set.Pairwise.Basic
import Mathlib.Data.Set.Lattice
import Mathlib.Data.SetLike.Basic
#align_import order.chain from "leanprover-community/mathlib"@"c227d107bbada5d0d9d20287e3282c0a7f1651a0"
open scoped Classical
open Set
variable {α β : Type*}
section Chain
variable (r : α → α → Prop)
local infixl:50 " ≺ " => r
def IsChain (s : Set α) : Prop :=
s.Pairwise fun x y => x ≺ y ∨ y ≺ x
#align is_chain IsChain
def SuperChain (s t : Set α) : Prop :=
IsChain r t ∧ s ⊂ t
#align super_chain SuperChain
def IsMaxChain (s : Set α) : Prop :=
IsChain r s ∧ ∀ ⦃t⦄, IsChain r t → s ⊆ t → s = t
#align is_max_chain IsMaxChain
variable {r} {c c₁ c₂ c₃ s t : Set α} {a b x y : α}
theorem isChain_empty : IsChain r ∅ :=
Set.pairwise_empty _
#align is_chain_empty isChain_empty
theorem Set.Subsingleton.isChain (hs : s.Subsingleton) : IsChain r s :=
hs.pairwise _
#align set.subsingleton.is_chain Set.Subsingleton.isChain
theorem IsChain.mono : s ⊆ t → IsChain r t → IsChain r s :=
Set.Pairwise.mono
#align is_chain.mono IsChain.mono
theorem IsChain.mono_rel {r' : α → α → Prop} (h : IsChain r s) (h_imp : ∀ x y, r x y → r' x y) :
IsChain r' s :=
h.mono' fun x y => Or.imp (h_imp x y) (h_imp y x)
#align is_chain.mono_rel IsChain.mono_rel
theorem IsChain.symm (h : IsChain r s) : IsChain (flip r) s :=
h.mono' fun _ _ => Or.symm
#align is_chain.symm IsChain.symm
theorem isChain_of_trichotomous [IsTrichotomous α r] (s : Set α) : IsChain r s :=
fun a _ b _ hab => (trichotomous_of r a b).imp_right fun h => h.resolve_left hab
#align is_chain_of_trichotomous isChain_of_trichotomous
protected theorem IsChain.insert (hs : IsChain r s) (ha : ∀ b ∈ s, a ≠ b → a ≺ b ∨ b ≺ a) :
IsChain r (insert a s) :=
hs.insert_of_symmetric (fun _ _ => Or.symm) ha
#align is_chain.insert IsChain.insert
| Mathlib/Order/Chain.lean | 95 | 98 | theorem isChain_univ_iff : IsChain r (univ : Set α) ↔ IsTrichotomous α r := by |
refine ⟨fun h => ⟨fun a b => ?_⟩, fun h => @isChain_of_trichotomous _ _ h univ⟩
rw [or_left_comm, or_iff_not_imp_left]
exact h trivial trivial
|
import Mathlib.LinearAlgebra.AffineSpace.AffineMap
import Mathlib.Topology.Algebra.Group.Basic
import Mathlib.Topology.Algebra.MulAction
#align_import topology.algebra.affine from "leanprover-community/mathlib"@"717c073262cd9d59b1a1dcda7e8ab570c5b63370"
namespace AffineMap
variable {R E F : Type*}
variable [AddCommGroup E] [TopologicalSpace E]
variable [AddCommGroup F] [TopologicalSpace F] [TopologicalAddGroup F]
section Ring
variable [Ring R] [Module R E] [Module R F]
| Mathlib/Topology/Algebra/Affine.lean | 36 | 43 | theorem continuous_iff {f : E →ᵃ[R] F} : Continuous f ↔ Continuous f.linear := by |
constructor
· intro hc
rw [decomp' f]
exact hc.sub continuous_const
· intro hc
rw [decomp f]
exact hc.add continuous_const
|
import Mathlib.Combinatorics.Young.YoungDiagram
#align_import combinatorics.young.semistandard_tableau from "leanprover-community/mathlib"@"b363547b3113d350d053abdf2884e9850a56b205"
structure SemistandardYoungTableau (μ : YoungDiagram) where
entry : ℕ → ℕ → ℕ
row_weak' : ∀ {i j1 j2 : ℕ}, j1 < j2 → (i, j2) ∈ μ → entry i j1 ≤ entry i j2
col_strict' : ∀ {i1 i2 j : ℕ}, i1 < i2 → (i2, j) ∈ μ → entry i1 j < entry i2 j
zeros' : ∀ {i j}, (i, j) ∉ μ → entry i j = 0
#align ssyt SemistandardYoungTableau
namespace SemistandardYoungTableau
instance instFunLike {μ : YoungDiagram} : FunLike (SemistandardYoungTableau μ) ℕ (ℕ → ℕ) where
coe := SemistandardYoungTableau.entry
coe_injective' T T' h := by
cases T
cases T'
congr
#align ssyt.fun_like SemistandardYoungTableau.instFunLike
instance {μ : YoungDiagram} : CoeFun (SemistandardYoungTableau μ) fun _ ↦ ℕ → ℕ → ℕ :=
inferInstance
@[simp]
theorem to_fun_eq_coe {μ : YoungDiagram} {T : SemistandardYoungTableau μ} :
T.entry = (T : ℕ → ℕ → ℕ) :=
rfl
#align ssyt.to_fun_eq_coe SemistandardYoungTableau.to_fun_eq_coe
@[ext]
theorem ext {μ : YoungDiagram} {T T' : SemistandardYoungTableau μ} (h : ∀ i j, T i j = T' i j) :
T = T' :=
DFunLike.ext T T' fun _ ↦ by
funext
apply h
#align ssyt.ext SemistandardYoungTableau.ext
protected def copy {μ : YoungDiagram} (T : SemistandardYoungTableau μ) (entry' : ℕ → ℕ → ℕ)
(h : entry' = T) : SemistandardYoungTableau μ where
entry := entry'
row_weak' := h.symm ▸ T.row_weak'
col_strict' := h.symm ▸ T.col_strict'
zeros' := h.symm ▸ T.zeros'
#align ssyt.copy SemistandardYoungTableau.copy
@[simp]
theorem coe_copy {μ : YoungDiagram} (T : SemistandardYoungTableau μ) (entry' : ℕ → ℕ → ℕ)
(h : entry' = T) : ⇑(T.copy entry' h) = entry' :=
rfl
#align ssyt.coe_copy SemistandardYoungTableau.coe_copy
theorem copy_eq {μ : YoungDiagram} (T : SemistandardYoungTableau μ) (entry' : ℕ → ℕ → ℕ)
(h : entry' = T) : T.copy entry' h = T :=
DFunLike.ext' h
#align ssyt.copy_eq SemistandardYoungTableau.copy_eq
theorem row_weak {μ : YoungDiagram} (T : SemistandardYoungTableau μ) {i j1 j2 : ℕ} (hj : j1 < j2)
(hcell : (i, j2) ∈ μ) : T i j1 ≤ T i j2 :=
T.row_weak' hj hcell
#align ssyt.row_weak SemistandardYoungTableau.row_weak
theorem col_strict {μ : YoungDiagram} (T : SemistandardYoungTableau μ) {i1 i2 j : ℕ} (hi : i1 < i2)
(hcell : (i2, j) ∈ μ) : T i1 j < T i2 j :=
T.col_strict' hi hcell
#align ssyt.col_strict SemistandardYoungTableau.col_strict
theorem zeros {μ : YoungDiagram} (T : SemistandardYoungTableau μ) {i j : ℕ}
(not_cell : (i, j) ∉ μ) : T i j = 0 :=
T.zeros' not_cell
#align ssyt.zeros SemistandardYoungTableau.zeros
theorem row_weak_of_le {μ : YoungDiagram} (T : SemistandardYoungTableau μ) {i j1 j2 : ℕ}
(hj : j1 ≤ j2) (cell : (i, j2) ∈ μ) : T i j1 ≤ T i j2 := by
cases' eq_or_lt_of_le hj with h h
· rw [h]
· exact T.row_weak h cell
#align ssyt.row_weak_of_le SemistandardYoungTableau.row_weak_of_le
| Mathlib/Combinatorics/Young/SemistandardTableau.lean | 136 | 140 | theorem col_weak {μ : YoungDiagram} (T : SemistandardYoungTableau μ) {i1 i2 j : ℕ} (hi : i1 ≤ i2)
(cell : (i2, j) ∈ μ) : T i1 j ≤ T i2 j := by |
cases' eq_or_lt_of_le hi with h h
· rw [h]
· exact le_of_lt (T.col_strict h cell)
|
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]
| Mathlib/Analysis/SpecialFunctions/Trigonometric/Angle.lean | 107 | 108 | 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
|
import Mathlib.CategoryTheory.Functor.Basic
import Mathlib.Util.AddRelatedDecl
import Mathlib.Lean.Meta.Simp
open Lean Meta Elab Tactic
open Mathlib.Tactic
namespace CategoryTheory
variable {C : Type*} [Category C]
| Mathlib/Tactic/CategoryTheory/Reassoc.lean | 34 | 35 | theorem eq_whisker' {X Y : C} {f g : X ⟶ Y} (w : f = g) {Z : C} (h : Y ⟶ Z) :
f ≫ h = g ≫ h := by | rw [w]
|
import Mathlib.Topology.UniformSpace.CompactConvergence
import Mathlib.Topology.UniformSpace.Equicontinuity
import Mathlib.Topology.UniformSpace.Equiv
open Set Filter Uniformity Topology Function UniformConvergence
variable {ι X Y α β : Type*} [TopologicalSpace X] [UniformSpace α] [UniformSpace β]
variable {F : ι → X → α} {G : ι → β → α}
theorem Equicontinuous.comap_uniformFun_eq [CompactSpace X] (F_eqcont : Equicontinuous F) :
(UniformFun.uniformSpace X α).comap F =
(Pi.uniformSpace _).comap F := by
-- The `≤` inequality is trivial
refine le_antisymm (UniformSpace.comap_mono UniformFun.uniformContinuous_toFun) ?_
-- A bit of rewriting to get a nice intermediate statement.
change comap _ _ ≤ comap _ _
simp_rw [Pi.uniformity, Filter.comap_iInf, comap_comap, Function.comp]
refine ((UniformFun.hasBasis_uniformity X α).comap (Prod.map F F)).ge_iff.mpr ?_
-- Core of the proof: we need to show that, for any entourage `U` in `α`,
-- the set `𝐓(U) := {(i,j) : ι × ι | ∀ x : X, (F i x, F j x) ∈ U}` belongs to the filter
-- `⨅ x, comap ((i,j) ↦ (F i x, F j x)) (𝓤 α)`.
-- In other words, we have to show that it contains a finite intersection of
-- sets of the form `𝐒(V, x) := {(i,j) : ι × ι | (F i x, F j x) ∈ V}` for some
-- `x : X` and `V ∈ 𝓤 α`.
intro U hU
-- We will do an `ε/3` argument, so we start by choosing a symmetric entourage `V ∈ 𝓤 α`
-- such that `V ○ V ○ V ⊆ U`.
rcases comp_comp_symm_mem_uniformity_sets hU with ⟨V, hV, Vsymm, hVU⟩
-- Set `Ω x := {y | ∀ i, (F i x, F i y) ∈ V}`. The equicontinuity of `F` guarantees that
-- each `Ω x` is a neighborhood of `x`.
let Ω x : Set X := {y | ∀ i, (F i x, F i y) ∈ V}
-- Hence, by compactness of `X`, we can find some `A ⊆ X` finite such that the `Ω a`s for `a ∈ A`
-- still cover `X`.
rcases CompactSpace.elim_nhds_subcover Ω (fun x ↦ F_eqcont x V hV) with ⟨A, Acover⟩
-- We now claim that `⋂ a ∈ A, 𝐒(V, a) ⊆ 𝐓(U)`.
have : (⋂ a ∈ A, {ij : ι × ι | (F ij.1 a, F ij.2 a) ∈ V}) ⊆
(Prod.map F F) ⁻¹' UniformFun.gen X α U := by
-- Given `(i, j) ∈ ⋂ a ∈ A, 𝐒(V, a)` and `x : X`, we have to prove that `(F i x, F j x) ∈ U`.
rintro ⟨i, j⟩ hij x
rw [mem_iInter₂] at hij
-- We know that `x ∈ Ω a` for some `a ∈ A`, so that both `(F i x, F i a)` and `(F j a, F j x)`
-- are in `V`.
rcases mem_iUnion₂.mp (Acover.symm.subset <| mem_univ x) with ⟨a, ha, hax⟩
-- Since `(i, j) ∈ 𝐒(V, a)` we also have `(F i a, F j a) ∈ V`, and finally we get
-- `(F i x, F j x) ∈ V ○ V ○ V ⊆ U`.
exact hVU (prod_mk_mem_compRel (prod_mk_mem_compRel
(Vsymm.mk_mem_comm.mp (hax i)) (hij a ha)) (hax j))
-- This completes the proof.
exact mem_of_superset
(A.iInter_mem_sets.mpr fun x _ ↦ mem_iInf_of_mem x <| preimage_mem_comap hV) this
lemma Equicontinuous.uniformInducing_uniformFun_iff_pi [UniformSpace ι] [CompactSpace X]
(F_eqcont : Equicontinuous F) :
UniformInducing (UniformFun.ofFun ∘ F) ↔ UniformInducing F := by
rw [uniformInducing_iff_uniformSpace, uniformInducing_iff_uniformSpace,
← F_eqcont.comap_uniformFun_eq]
rfl
lemma Equicontinuous.inducing_uniformFun_iff_pi [TopologicalSpace ι] [CompactSpace X]
(F_eqcont : Equicontinuous F) :
Inducing (UniformFun.ofFun ∘ F) ↔ Inducing F := by
rw [inducing_iff, inducing_iff]
change (_ = (UniformFun.uniformSpace X α |>.comap F |>.toTopologicalSpace)) ↔
(_ = (Pi.uniformSpace _ |>.comap F |>.toTopologicalSpace))
rw [F_eqcont.comap_uniformFun_eq]
theorem Equicontinuous.tendsto_uniformFun_iff_pi [CompactSpace X]
(F_eqcont : Equicontinuous F) (ℱ : Filter ι) (f : X → α) :
Tendsto (UniformFun.ofFun ∘ F) ℱ (𝓝 <| UniformFun.ofFun f) ↔
Tendsto F ℱ (𝓝 f) := by
-- Assume `ℱ` is non trivial.
rcases ℱ.eq_or_neBot with rfl | ℱ_ne
· simp
constructor <;> intro H
-- The forward direction is always true, the interesting part is the converse.
· exact UniformFun.uniformContinuous_toFun.continuous.tendsto _|>.comp H
-- To prove it, assume that `F` tends to `f` *pointwise* along `ℱ`.
· set S : Set (X → α) := closure (range F)
set 𝒢 : Filter S := comap (↑) (map F ℱ)
-- We would like to use `Equicontinuous.comap_uniformFun_eq`, but applying it to `F` is not
-- enough since `f` has no reason to be in the range of `F`.
-- Instead, we will apply it to the inclusion `(↑) : S → (X → α)` where `S` is the closure of
-- the range of `F` *for the product topology*.
-- We know that `S` is still equicontinuous...
have hS : S.Equicontinuous := closure' (by rwa [equicontinuous_iff_range] at F_eqcont)
continuous_id
-- ... hence, as announced, the product topology and uniform convergence topology
-- coincide on `S`.
have ind : Inducing (UniformFun.ofFun ∘ (↑) : S → X →ᵤ α) :=
hS.inducing_uniformFun_iff_pi.mpr ⟨rfl⟩
-- By construction, `f` is in `S`.
have f_mem : f ∈ S := mem_closure_of_tendsto H range_mem_map
-- To conclude, we just have to translate our hypothesis and goal as statements about
-- `S`, on which we know the two topologies at play coincide.
-- For this, we define a filter on `S` by `𝒢 := comap (↑) (map F ℱ)`, and note that
-- it satisfies `map (↑) 𝒢 = map F ℱ`. Thus, both our hypothesis and our goal
-- can be rewritten as `𝒢 ≤ 𝓝 f`, where the neighborhood filter in the RHS corresponds
-- to one of the two topologies at play on `S`. Since they coincide, we are done.
have h𝒢ℱ : map (↑) 𝒢 = map F ℱ := Filter.map_comap_of_mem
(Subtype.range_coe ▸ mem_of_superset range_mem_map subset_closure)
have H' : Tendsto id 𝒢 (𝓝 ⟨f, f_mem⟩) := by
rwa [tendsto_id', nhds_induced, ← map_le_iff_le_comap, h𝒢ℱ]
rwa [ind.tendsto_nhds_iff, comp_id, ← tendsto_map'_iff, h𝒢ℱ] at H'
theorem EquicontinuousOn.comap_uniformOnFun_eq {𝔖 : Set (Set X)} (𝔖_compact : ∀ K ∈ 𝔖, IsCompact K)
(F_eqcont : ∀ K ∈ 𝔖, EquicontinuousOn F K) :
(UniformOnFun.uniformSpace X α 𝔖).comap F =
(Pi.uniformSpace _).comap ((⋃₀ 𝔖).restrict ∘ F) := by
-- Recall that the uniform structure on `X →ᵤ[𝔖] α` is the one induced by all the maps
-- `K.restrict : (X →ᵤ[𝔖] α) → (K →ᵤ α)` for `K ∈ 𝔖`. Its pullback along `F`, which is
-- the LHS of our goal, is thus the uniform structure induced by the maps
-- `K.restrict ∘ F : ι → (K →ᵤ α)` for `K ∈ 𝔖`.
have H1 : (UniformOnFun.uniformSpace X α 𝔖).comap F =
⨅ (K ∈ 𝔖), (UniformFun.uniformSpace _ _).comap (K.restrict ∘ F) := by
simp_rw [UniformOnFun.uniformSpace, UniformSpace.comap_iInf, ← UniformSpace.comap_comap,
UniformFun.ofFun, Equiv.coe_fn_mk, UniformOnFun.toFun, UniformOnFun.ofFun, Function.comp,
UniformFun, Equiv.coe_fn_symm_mk]
-- Now, note that a similar fact is true for the uniform structure on `X → α` induced by
-- the map `(⋃₀ 𝔖).restrict : (X → α) → ((⋃₀ 𝔖) → α)`: it is equal to the one induced by
-- all maps `K.restrict : (X → α) → (K → α)` for `K ∈ 𝔖`, which means that the RHS of our
-- goal is the uniform structure induced by the maps `K.restrict ∘ F : ι → (K → α)` for `K ∈ 𝔖`.
have H2 : (Pi.uniformSpace _).comap ((⋃₀ 𝔖).restrict ∘ F) =
⨅ (K ∈ 𝔖), (Pi.uniformSpace _).comap (K.restrict ∘ F) := by
simp_rw [UniformSpace.comap_comap, Pi.uniformSpace_comap_restrict_sUnion (fun _ ↦ α) 𝔖,
UniformSpace.comap_iInf]
-- But, for `K ∈ 𝔖` fixed, we know that the uniform structures of `K →ᵤ α` and `K → α`
-- induce, via the equicontinuous family `K.restrict ∘ F`, the same uniform structure on `ι`.
have H3 : ∀ K ∈ 𝔖, (UniformFun.uniformSpace K α).comap (K.restrict ∘ F) =
(Pi.uniformSpace _).comap (K.restrict ∘ F) := fun K hK ↦ by
have : CompactSpace K := isCompact_iff_compactSpace.mp (𝔖_compact K hK)
exact (equicontinuous_restrict_iff _ |>.mpr <| F_eqcont K hK).comap_uniformFun_eq
-- Combining these three facts completes the proof.
simp_rw [H1, H2, iInf_congr fun K ↦ iInf_congr fun hK ↦ H3 K hK]
lemma EquicontinuousOn.uniformInducing_uniformOnFun_iff_pi' [UniformSpace ι]
{𝔖 : Set (Set X)} (𝔖_compact : ∀ K ∈ 𝔖, IsCompact K)
(F_eqcont : ∀ K ∈ 𝔖, EquicontinuousOn F K) :
UniformInducing (UniformOnFun.ofFun 𝔖 ∘ F) ↔
UniformInducing ((⋃₀ 𝔖).restrict ∘ F) := by
rw [uniformInducing_iff_uniformSpace, uniformInducing_iff_uniformSpace,
← EquicontinuousOn.comap_uniformOnFun_eq 𝔖_compact F_eqcont]
rfl
lemma EquicontinuousOn.uniformInducing_uniformOnFun_iff_pi [UniformSpace ι]
{𝔖 : Set (Set X)} (𝔖_covers : ⋃₀ 𝔖 = univ) (𝔖_compact : ∀ K ∈ 𝔖, IsCompact K)
(F_eqcont : ∀ K ∈ 𝔖, EquicontinuousOn F K) :
UniformInducing (UniformOnFun.ofFun 𝔖 ∘ F) ↔
UniformInducing F := by
rw [eq_univ_iff_forall] at 𝔖_covers
-- This obviously follows from the previous lemma, we formalize it by going through the
-- isomorphism of uniform spaces between `(⋃₀ 𝔖) → α` and `X → α`.
let φ : ((⋃₀ 𝔖) → α) ≃ᵤ (X → α) := UniformEquiv.piCongrLeft (β := fun _ ↦ α)
(Equiv.subtypeUnivEquiv 𝔖_covers)
rw [EquicontinuousOn.uniformInducing_uniformOnFun_iff_pi' 𝔖_compact F_eqcont,
show restrict (⋃₀ 𝔖) ∘ F = φ.symm ∘ F by rfl]
exact ⟨fun H ↦ φ.uniformInducing.comp H, fun H ↦ φ.symm.uniformInducing.comp H⟩
lemma EquicontinuousOn.inducing_uniformOnFun_iff_pi' [TopologicalSpace ι]
{𝔖 : Set (Set X)} (𝔖_compact : ∀ K ∈ 𝔖, IsCompact K)
(F_eqcont : ∀ K ∈ 𝔖, EquicontinuousOn F K) :
Inducing (UniformOnFun.ofFun 𝔖 ∘ F) ↔
Inducing ((⋃₀ 𝔖).restrict ∘ F) := by
rw [inducing_iff, inducing_iff]
change (_ = ((UniformOnFun.uniformSpace X α 𝔖).comap F).toTopologicalSpace) ↔
(_ = ((Pi.uniformSpace _).comap ((⋃₀ 𝔖).restrict ∘ F)).toTopologicalSpace)
rw [← EquicontinuousOn.comap_uniformOnFun_eq 𝔖_compact F_eqcont]
lemma EquicontinuousOn.inducing_uniformOnFun_iff_pi [TopologicalSpace ι]
{𝔖 : Set (Set X)} (𝔖_covers : ⋃₀ 𝔖 = univ) (𝔖_compact : ∀ K ∈ 𝔖, IsCompact K)
(F_eqcont : ∀ K ∈ 𝔖, EquicontinuousOn F K) :
Inducing (UniformOnFun.ofFun 𝔖 ∘ F) ↔
Inducing F := by
rw [eq_univ_iff_forall] at 𝔖_covers
-- This obviously follows from the previous lemma, we formalize it by going through the
-- homeomorphism between `(⋃₀ 𝔖) → α` and `X → α`.
let φ : ((⋃₀ 𝔖) → α) ≃ₜ (X → α) := Homeomorph.piCongrLeft (Y := fun _ ↦ α)
(Equiv.subtypeUnivEquiv 𝔖_covers)
rw [EquicontinuousOn.inducing_uniformOnFun_iff_pi' 𝔖_compact F_eqcont,
show restrict (⋃₀ 𝔖) ∘ F = φ.symm ∘ F by rfl]
exact ⟨fun H ↦ φ.inducing.comp H, fun H ↦ φ.symm.inducing.comp H⟩
-- TODO: find a way to factor common elements of this proof and the proof of
-- `EquicontinuousOn.comap_uniformOnFun_eq`
theorem EquicontinuousOn.tendsto_uniformOnFun_iff_pi'
{𝔖 : Set (Set X)} (𝔖_compact : ∀ K ∈ 𝔖, IsCompact K)
(F_eqcont : ∀ K ∈ 𝔖, EquicontinuousOn F K) (ℱ : Filter ι) (f : X → α) :
Tendsto (UniformOnFun.ofFun 𝔖 ∘ F) ℱ (𝓝 <| UniformOnFun.ofFun 𝔖 f) ↔
Tendsto ((⋃₀ 𝔖).restrict ∘ F) ℱ (𝓝 <| (⋃₀ 𝔖).restrict f) := by
-- Recall that the uniform structure on `X →ᵤ[𝔖] α` is the one induced by all the maps
-- `K.restrict : (X →ᵤ[𝔖] α) → (K →ᵤ α)` for `K ∈ 𝔖`.
-- Similarly, the uniform structure on `X → α` induced by the map
-- `(⋃₀ 𝔖).restrict : (X → α) → ((⋃₀ 𝔖) → α)` is equal to the one induced by
-- all maps `K.restrict : (X → α) → (K → α)` for `K ∈ 𝔖`
-- Thus, we just have to compare the two sides of our goal when restricted to some
-- `K ∈ 𝔖`, where we can apply `Equicontinuous.tendsto_uniformFun_iff_pi`.
rw [← Filter.tendsto_comap_iff (g := (⋃₀ 𝔖).restrict), ← nhds_induced]
simp_rw [UniformOnFun.topologicalSpace_eq, Pi.induced_restrict_sUnion 𝔖 (π := fun _ ↦ α),
_root_.nhds_iInf, nhds_induced, tendsto_iInf, tendsto_comap_iff]
congrm ∀ K (hK : K ∈ 𝔖), ?_
have : CompactSpace K := isCompact_iff_compactSpace.mp (𝔖_compact K hK)
rw [← (equicontinuous_restrict_iff _ |>.mpr <| F_eqcont K hK).tendsto_uniformFun_iff_pi]
rfl
theorem EquicontinuousOn.tendsto_uniformOnFun_iff_pi
{𝔖 : Set (Set X)} (𝔖_compact : ∀ K ∈ 𝔖, IsCompact K) (𝔖_covers : ⋃₀ 𝔖 = univ)
(F_eqcont : ∀ K ∈ 𝔖, EquicontinuousOn F K) (ℱ : Filter ι) (f : X → α) :
Tendsto (UniformOnFun.ofFun 𝔖 ∘ F) ℱ (𝓝 <| UniformOnFun.ofFun 𝔖 f) ↔
Tendsto F ℱ (𝓝 f) := by
rw [eq_univ_iff_forall] at 𝔖_covers
let φ : ((⋃₀ 𝔖) → α) ≃ₜ (X → α) := Homeomorph.piCongrLeft (Y := fun _ ↦ α)
(Equiv.subtypeUnivEquiv 𝔖_covers)
rw [EquicontinuousOn.tendsto_uniformOnFun_iff_pi' 𝔖_compact F_eqcont,
show restrict (⋃₀ 𝔖) ∘ F = φ.symm ∘ F by rfl, show restrict (⋃₀ 𝔖) f = φ.symm f by rfl,
φ.symm.inducing.tendsto_nhds_iff]
theorem EquicontinuousOn.isClosed_range_pi_of_uniformOnFun'
{𝔖 : Set (Set X)} (𝔖_compact : ∀ K ∈ 𝔖, IsCompact K)
(F_eqcont : ∀ K ∈ 𝔖, EquicontinuousOn F K)
(H : IsClosed (range <| UniformOnFun.ofFun 𝔖 ∘ F)) :
IsClosed (range <| (⋃₀ 𝔖).restrict ∘ F) := by
-- Do we have no equivalent of `nontriviality`?
rcases isEmpty_or_nonempty α with _ | _
· simp [isClosed_discrete]
-- This follows from the previous lemmas and the characterization of the closure using filters.
simp_rw [isClosed_iff_clusterPt, ← Filter.map_top, ← mapClusterPt_def,
mapClusterPt_iff_ultrafilter, range_comp, Subtype.coe_injective.surjective_comp_right.forall,
← restrict_eq, ← EquicontinuousOn.tendsto_uniformOnFun_iff_pi' 𝔖_compact F_eqcont]
exact fun f ⟨u, _, hu⟩ ↦ mem_image_of_mem _ <| H.mem_of_tendsto hu <|
eventually_of_forall mem_range_self
| Mathlib/Topology/UniformSpace/Ascoli.lean | 390 | 399 | theorem EquicontinuousOn.isClosed_range_uniformOnFun_iff_pi
{𝔖 : Set (Set X)} (𝔖_compact : ∀ K ∈ 𝔖, IsCompact K) (𝔖_covers : ⋃₀ 𝔖 = univ)
(F_eqcont : ∀ K ∈ 𝔖, EquicontinuousOn F K) :
IsClosed (range <| UniformOnFun.ofFun 𝔖 ∘ F) ↔
IsClosed (range F) := by |
-- This follows from the previous lemmas and the characterization of the closure using filters.
simp_rw [isClosed_iff_clusterPt, ← Filter.map_top, ← mapClusterPt_def,
mapClusterPt_iff_ultrafilter, range_comp, (UniformOnFun.ofFun 𝔖).surjective.forall,
← EquicontinuousOn.tendsto_uniformOnFun_iff_pi 𝔖_compact 𝔖_covers F_eqcont,
(UniformOnFun.ofFun 𝔖).injective.mem_set_image]
|
import Mathlib.Data.Finsupp.Multiset
import Mathlib.Order.Bounded
import Mathlib.SetTheory.Cardinal.PartENat
import Mathlib.SetTheory.Ordinal.Principal
import Mathlib.Tactic.Linarith
#align_import set_theory.cardinal.ordinal from "leanprover-community/mathlib"@"7c2ce0c2da15516b4e65d0c9e254bb6dc93abd1f"
noncomputable section
open Function Set Cardinal Equiv Order Ordinal
open scoped Classical
universe u v w
namespace Cardinal
section UsingOrdinals
theorem ord_isLimit {c} (co : ℵ₀ ≤ c) : (ord c).IsLimit := by
refine ⟨fun h => aleph0_ne_zero ?_, fun a => lt_imp_lt_of_le_imp_le fun h => ?_⟩
· rw [← Ordinal.le_zero, ord_le] at h
simpa only [card_zero, nonpos_iff_eq_zero] using co.trans h
· rw [ord_le] at h ⊢
rwa [← @add_one_of_aleph0_le (card a), ← card_succ]
rw [← ord_le, ← le_succ_of_isLimit, ord_le]
· exact co.trans h
· rw [ord_aleph0]
exact omega_isLimit
#align cardinal.ord_is_limit Cardinal.ord_isLimit
theorem noMaxOrder {c} (h : ℵ₀ ≤ c) : NoMaxOrder c.ord.out.α :=
Ordinal.out_no_max_of_succ_lt (ord_isLimit h).2
section aleph
def alephIdx.initialSeg : @InitialSeg Cardinal Ordinal (· < ·) (· < ·) :=
@RelEmbedding.collapse Cardinal Ordinal (· < ·) (· < ·) _ Cardinal.ord.orderEmbedding.ltEmbedding
#align cardinal.aleph_idx.initial_seg Cardinal.alephIdx.initialSeg
def alephIdx : Cardinal → Ordinal :=
alephIdx.initialSeg
#align cardinal.aleph_idx Cardinal.alephIdx
@[simp]
theorem alephIdx.initialSeg_coe : (alephIdx.initialSeg : Cardinal → Ordinal) = alephIdx :=
rfl
#align cardinal.aleph_idx.initial_seg_coe Cardinal.alephIdx.initialSeg_coe
@[simp]
theorem alephIdx_lt {a b} : alephIdx a < alephIdx b ↔ a < b :=
alephIdx.initialSeg.toRelEmbedding.map_rel_iff
#align cardinal.aleph_idx_lt Cardinal.alephIdx_lt
@[simp]
theorem alephIdx_le {a b} : alephIdx a ≤ alephIdx b ↔ a ≤ b := by
rw [← not_lt, ← not_lt, alephIdx_lt]
#align cardinal.aleph_idx_le Cardinal.alephIdx_le
theorem alephIdx.init {a b} : b < alephIdx a → ∃ c, alephIdx c = b :=
alephIdx.initialSeg.init
#align cardinal.aleph_idx.init Cardinal.alephIdx.init
def alephIdx.relIso : @RelIso Cardinal.{u} Ordinal.{u} (· < ·) (· < ·) :=
@RelIso.ofSurjective Cardinal.{u} Ordinal.{u} (· < ·) (· < ·) alephIdx.initialSeg.{u} <|
(InitialSeg.eq_or_principal alephIdx.initialSeg.{u}).resolve_right fun ⟨o, e⟩ => by
have : ∀ c, alephIdx c < o := fun c => (e _).2 ⟨_, rfl⟩
refine Ordinal.inductionOn o ?_ this; intro α r _ h
let s := ⨆ a, invFun alephIdx (Ordinal.typein r a)
apply (lt_succ s).not_le
have I : Injective.{u+2, u+2} alephIdx := alephIdx.initialSeg.toEmbedding.injective
simpa only [typein_enum, leftInverse_invFun I (succ s)] using
le_ciSup
(Cardinal.bddAbove_range.{u, u} fun a : α => invFun alephIdx (Ordinal.typein r a))
(Ordinal.enum r _ (h (succ s)))
#align cardinal.aleph_idx.rel_iso Cardinal.alephIdx.relIso
@[simp]
theorem alephIdx.relIso_coe : (alephIdx.relIso : Cardinal → Ordinal) = alephIdx :=
rfl
#align cardinal.aleph_idx.rel_iso_coe Cardinal.alephIdx.relIso_coe
@[simp]
theorem type_cardinal : @type Cardinal (· < ·) _ = Ordinal.univ.{u, u + 1} := by
rw [Ordinal.univ_id]; exact Quotient.sound ⟨alephIdx.relIso⟩
#align cardinal.type_cardinal Cardinal.type_cardinal
@[simp]
theorem mk_cardinal : #Cardinal = univ.{u, u + 1} := by
simpa only [card_type, card_univ] using congr_arg card type_cardinal
#align cardinal.mk_cardinal Cardinal.mk_cardinal
def Aleph'.relIso :=
Cardinal.alephIdx.relIso.symm
#align cardinal.aleph'.rel_iso Cardinal.Aleph'.relIso
def aleph' : Ordinal → Cardinal :=
Aleph'.relIso
#align cardinal.aleph' Cardinal.aleph'
@[simp]
theorem aleph'.relIso_coe : (Aleph'.relIso : Ordinal → Cardinal) = aleph' :=
rfl
#align cardinal.aleph'.rel_iso_coe Cardinal.aleph'.relIso_coe
@[simp]
theorem aleph'_lt {o₁ o₂ : Ordinal} : aleph' o₁ < aleph' o₂ ↔ o₁ < o₂ :=
Aleph'.relIso.map_rel_iff
#align cardinal.aleph'_lt Cardinal.aleph'_lt
@[simp]
theorem aleph'_le {o₁ o₂ : Ordinal} : aleph' o₁ ≤ aleph' o₂ ↔ o₁ ≤ o₂ :=
le_iff_le_iff_lt_iff_lt.2 aleph'_lt
#align cardinal.aleph'_le Cardinal.aleph'_le
@[simp]
theorem aleph'_alephIdx (c : Cardinal) : aleph' c.alephIdx = c :=
Cardinal.alephIdx.relIso.toEquiv.symm_apply_apply c
#align cardinal.aleph'_aleph_idx Cardinal.aleph'_alephIdx
@[simp]
theorem alephIdx_aleph' (o : Ordinal) : (aleph' o).alephIdx = o :=
Cardinal.alephIdx.relIso.toEquiv.apply_symm_apply o
#align cardinal.aleph_idx_aleph' Cardinal.alephIdx_aleph'
@[simp]
theorem aleph'_zero : aleph' 0 = 0 := by
rw [← nonpos_iff_eq_zero, ← aleph'_alephIdx 0, aleph'_le]
apply Ordinal.zero_le
#align cardinal.aleph'_zero Cardinal.aleph'_zero
@[simp]
theorem aleph'_succ {o : Ordinal} : aleph' (succ o) = succ (aleph' o) := by
apply (succ_le_of_lt <| aleph'_lt.2 <| lt_succ o).antisymm' (Cardinal.alephIdx_le.1 <| _)
rw [alephIdx_aleph', succ_le_iff, ← aleph'_lt, aleph'_alephIdx]
apply lt_succ
#align cardinal.aleph'_succ Cardinal.aleph'_succ
@[simp]
theorem aleph'_nat : ∀ n : ℕ, aleph' n = n
| 0 => aleph'_zero
| n + 1 => show aleph' (succ n) = n.succ by rw [aleph'_succ, aleph'_nat n, nat_succ]
#align cardinal.aleph'_nat Cardinal.aleph'_nat
theorem aleph'_le_of_limit {o : Ordinal} (l : o.IsLimit) {c} :
aleph' o ≤ c ↔ ∀ o' < o, aleph' o' ≤ c :=
⟨fun h o' h' => (aleph'_le.2 <| h'.le).trans h, fun h => by
rw [← aleph'_alephIdx c, aleph'_le, limit_le l]
intro x h'
rw [← aleph'_le, aleph'_alephIdx]
exact h _ h'⟩
#align cardinal.aleph'_le_of_limit Cardinal.aleph'_le_of_limit
theorem aleph'_limit {o : Ordinal} (ho : o.IsLimit) : aleph' o = ⨆ a : Iio o, aleph' a := by
refine le_antisymm ?_ (ciSup_le' fun i => aleph'_le.2 (le_of_lt i.2))
rw [aleph'_le_of_limit ho]
exact fun a ha => le_ciSup (bddAbove_of_small _) (⟨a, ha⟩ : Iio o)
#align cardinal.aleph'_limit Cardinal.aleph'_limit
@[simp]
theorem aleph'_omega : aleph' ω = ℵ₀ :=
eq_of_forall_ge_iff fun c => by
simp only [aleph'_le_of_limit omega_isLimit, lt_omega, exists_imp, aleph0_le]
exact forall_swap.trans (forall_congr' fun n => by simp only [forall_eq, aleph'_nat])
#align cardinal.aleph'_omega Cardinal.aleph'_omega
@[simp]
def aleph'Equiv : Ordinal ≃ Cardinal :=
⟨aleph', alephIdx, alephIdx_aleph', aleph'_alephIdx⟩
#align cardinal.aleph'_equiv Cardinal.aleph'Equiv
def aleph (o : Ordinal) : Cardinal :=
aleph' (ω + o)
#align cardinal.aleph Cardinal.aleph
@[simp]
theorem aleph_lt {o₁ o₂ : Ordinal} : aleph o₁ < aleph o₂ ↔ o₁ < o₂ :=
aleph'_lt.trans (add_lt_add_iff_left _)
#align cardinal.aleph_lt Cardinal.aleph_lt
@[simp]
theorem aleph_le {o₁ o₂ : Ordinal} : aleph o₁ ≤ aleph o₂ ↔ o₁ ≤ o₂ :=
le_iff_le_iff_lt_iff_lt.2 aleph_lt
#align cardinal.aleph_le Cardinal.aleph_le
@[simp]
theorem max_aleph_eq (o₁ o₂ : Ordinal) : max (aleph o₁) (aleph o₂) = aleph (max o₁ o₂) := by
rcases le_total (aleph o₁) (aleph o₂) with h | h
· rw [max_eq_right h, max_eq_right (aleph_le.1 h)]
· rw [max_eq_left h, max_eq_left (aleph_le.1 h)]
#align cardinal.max_aleph_eq Cardinal.max_aleph_eq
@[simp]
theorem aleph_succ {o : Ordinal} : aleph (succ o) = succ (aleph o) := by
rw [aleph, add_succ, aleph'_succ, aleph]
#align cardinal.aleph_succ Cardinal.aleph_succ
@[simp]
theorem aleph_zero : aleph 0 = ℵ₀ := by rw [aleph, add_zero, aleph'_omega]
#align cardinal.aleph_zero Cardinal.aleph_zero
theorem aleph_limit {o : Ordinal} (ho : o.IsLimit) : aleph o = ⨆ a : Iio o, aleph a := by
apply le_antisymm _ (ciSup_le' _)
· rw [aleph, aleph'_limit (ho.add _)]
refine ciSup_mono' (bddAbove_of_small _) ?_
rintro ⟨i, hi⟩
cases' lt_or_le i ω with h h
· rcases lt_omega.1 h with ⟨n, rfl⟩
use ⟨0, ho.pos⟩
simpa using (nat_lt_aleph0 n).le
· exact ⟨⟨_, (sub_lt_of_le h).2 hi⟩, aleph'_le.2 (le_add_sub _ _)⟩
· exact fun i => aleph_le.2 (le_of_lt i.2)
#align cardinal.aleph_limit Cardinal.aleph_limit
theorem aleph0_le_aleph' {o : Ordinal} : ℵ₀ ≤ aleph' o ↔ ω ≤ o := by rw [← aleph'_omega, aleph'_le]
#align cardinal.aleph_0_le_aleph' Cardinal.aleph0_le_aleph'
theorem aleph0_le_aleph (o : Ordinal) : ℵ₀ ≤ aleph o := by
rw [aleph, aleph0_le_aleph']
apply Ordinal.le_add_right
#align cardinal.aleph_0_le_aleph Cardinal.aleph0_le_aleph
theorem aleph'_pos {o : Ordinal} (ho : 0 < o) : 0 < aleph' o := by rwa [← aleph'_zero, aleph'_lt]
#align cardinal.aleph'_pos Cardinal.aleph'_pos
theorem aleph_pos (o : Ordinal) : 0 < aleph o :=
aleph0_pos.trans_le (aleph0_le_aleph o)
#align cardinal.aleph_pos Cardinal.aleph_pos
@[simp]
theorem aleph_toNat (o : Ordinal) : toNat (aleph o) = 0 :=
toNat_apply_of_aleph0_le <| aleph0_le_aleph o
#align cardinal.aleph_to_nat Cardinal.aleph_toNat
@[simp]
theorem aleph_toPartENat (o : Ordinal) : toPartENat (aleph o) = ⊤ :=
toPartENat_apply_of_aleph0_le <| aleph0_le_aleph o
#align cardinal.aleph_to_part_enat Cardinal.aleph_toPartENat
instance nonempty_out_aleph (o : Ordinal) : Nonempty (aleph o).ord.out.α := by
rw [out_nonempty_iff_ne_zero, ← ord_zero]
exact fun h => (ord_injective h).not_gt (aleph_pos o)
#align cardinal.nonempty_out_aleph Cardinal.nonempty_out_aleph
theorem ord_aleph_isLimit (o : Ordinal) : (aleph o).ord.IsLimit :=
ord_isLimit <| aleph0_le_aleph _
#align cardinal.ord_aleph_is_limit Cardinal.ord_aleph_isLimit
instance (o : Ordinal) : NoMaxOrder (aleph o).ord.out.α :=
out_no_max_of_succ_lt (ord_aleph_isLimit o).2
theorem exists_aleph {c : Cardinal} : ℵ₀ ≤ c ↔ ∃ o, c = aleph o :=
⟨fun h =>
⟨alephIdx c - ω, by
rw [aleph, Ordinal.add_sub_cancel_of_le, aleph'_alephIdx]
rwa [← aleph0_le_aleph', aleph'_alephIdx]⟩,
fun ⟨o, e⟩ => e.symm ▸ aleph0_le_aleph _⟩
#align cardinal.exists_aleph Cardinal.exists_aleph
theorem aleph'_isNormal : IsNormal (ord ∘ aleph') :=
⟨fun o => ord_lt_ord.2 <| aleph'_lt.2 <| lt_succ o, fun o l a => by
simp [ord_le, aleph'_le_of_limit l]⟩
#align cardinal.aleph'_is_normal Cardinal.aleph'_isNormal
theorem aleph_isNormal : IsNormal (ord ∘ aleph) :=
aleph'_isNormal.trans <| add_isNormal ω
#align cardinal.aleph_is_normal Cardinal.aleph_isNormal
theorem succ_aleph0 : succ ℵ₀ = aleph 1 := by rw [← aleph_zero, ← aleph_succ, Ordinal.succ_zero]
#align cardinal.succ_aleph_0 Cardinal.succ_aleph0
theorem aleph0_lt_aleph_one : ℵ₀ < aleph 1 := by
rw [← succ_aleph0]
apply lt_succ
#align cardinal.aleph_0_lt_aleph_one Cardinal.aleph0_lt_aleph_one
| Mathlib/SetTheory/Cardinal/Ordinal.lean | 352 | 353 | theorem countable_iff_lt_aleph_one {α : Type*} (s : Set α) : s.Countable ↔ #s < aleph 1 := by |
rw [← succ_aleph0, lt_succ_iff, le_aleph0_iff_set_countable]
|
import Mathlib.RingTheory.DedekindDomain.Ideal
import Mathlib.RingTheory.Valuation.ExtendToLocalization
import Mathlib.RingTheory.Valuation.ValuationSubring
import Mathlib.Topology.Algebra.ValuedField
import Mathlib.Algebra.Order.Group.TypeTags
#align_import ring_theory.dedekind_domain.adic_valuation from "leanprover-community/mathlib"@"f0c8bf9245297a541f468be517f1bde6195105e9"
noncomputable section
open scoped Classical DiscreteValuation
open Multiplicative IsDedekindDomain
variable {R : Type*} [CommRing R] [IsDedekindDomain R] {K : Type*} [Field K]
[Algebra R K] [IsFractionRing R K] (v : HeightOneSpectrum R)
namespace IsDedekindDomain.HeightOneSpectrum
def intValuationDef (r : R) : ℤₘ₀ :=
if r = 0 then 0
else
↑(Multiplicative.ofAdd
(-(Associates.mk v.asIdeal).count (Associates.mk (Ideal.span {r} : Ideal R)).factors : ℤ))
#align is_dedekind_domain.height_one_spectrum.int_valuation_def IsDedekindDomain.HeightOneSpectrum.intValuationDef
theorem intValuationDef_if_pos {r : R} (hr : r = 0) : v.intValuationDef r = 0 :=
if_pos hr
#align is_dedekind_domain.height_one_spectrum.int_valuation_def_if_pos IsDedekindDomain.HeightOneSpectrum.intValuationDef_if_pos
theorem intValuationDef_if_neg {r : R} (hr : r ≠ 0) :
v.intValuationDef r =
Multiplicative.ofAdd
(-(Associates.mk v.asIdeal).count (Associates.mk (Ideal.span {r} : Ideal R)).factors : ℤ) :=
if_neg hr
#align is_dedekind_domain.height_one_spectrum.int_valuation_def_if_neg IsDedekindDomain.HeightOneSpectrum.intValuationDef_if_neg
theorem int_valuation_ne_zero (x : R) (hx : x ≠ 0) : v.intValuationDef x ≠ 0 := by
rw [intValuationDef, if_neg hx]
exact WithZero.coe_ne_zero
#align is_dedekind_domain.height_one_spectrum.int_valuation_ne_zero IsDedekindDomain.HeightOneSpectrum.int_valuation_ne_zero
theorem int_valuation_ne_zero' (x : nonZeroDivisors R) : v.intValuationDef x ≠ 0 :=
v.int_valuation_ne_zero x (nonZeroDivisors.coe_ne_zero x)
#align is_dedekind_domain.height_one_spectrum.int_valuation_ne_zero' IsDedekindDomain.HeightOneSpectrum.int_valuation_ne_zero'
theorem int_valuation_zero_le (x : nonZeroDivisors R) : 0 < v.intValuationDef x := by
rw [v.intValuationDef_if_neg (nonZeroDivisors.coe_ne_zero x)]
exact WithZero.zero_lt_coe _
#align is_dedekind_domain.height_one_spectrum.int_valuation_zero_le IsDedekindDomain.HeightOneSpectrum.int_valuation_zero_le
theorem int_valuation_le_one (x : R) : v.intValuationDef x ≤ 1 := by
rw [intValuationDef]
by_cases hx : x = 0
· rw [if_pos hx]; exact WithZero.zero_le 1
· rw [if_neg hx, ← WithZero.coe_one, ← ofAdd_zero, WithZero.coe_le_coe, ofAdd_le,
Right.neg_nonpos_iff]
exact Int.natCast_nonneg _
#align is_dedekind_domain.height_one_spectrum.int_valuation_le_one IsDedekindDomain.HeightOneSpectrum.int_valuation_le_one
theorem int_valuation_lt_one_iff_dvd (r : R) :
v.intValuationDef r < 1 ↔ v.asIdeal ∣ Ideal.span {r} := by
rw [intValuationDef]
split_ifs with hr
· simp [hr]
· rw [← WithZero.coe_one, ← ofAdd_zero, WithZero.coe_lt_coe, ofAdd_lt, neg_lt_zero, ←
Int.ofNat_zero, Int.ofNat_lt, zero_lt_iff]
have h : (Ideal.span {r} : Ideal R) ≠ 0 := by
rw [Ne, Ideal.zero_eq_bot, Ideal.span_singleton_eq_bot]
exact hr
apply Associates.count_ne_zero_iff_dvd h (by apply v.irreducible)
#align is_dedekind_domain.height_one_spectrum.int_valuation_lt_one_iff_dvd IsDedekindDomain.HeightOneSpectrum.int_valuation_lt_one_iff_dvd
theorem int_valuation_le_pow_iff_dvd (r : R) (n : ℕ) :
v.intValuationDef r ≤ Multiplicative.ofAdd (-(n : ℤ)) ↔ v.asIdeal ^ n ∣ Ideal.span {r} := by
rw [intValuationDef]
split_ifs with hr
· simp_rw [hr, Ideal.dvd_span_singleton, zero_le', Submodule.zero_mem]
· rw [WithZero.coe_le_coe, ofAdd_le, neg_le_neg_iff, Int.ofNat_le, Ideal.dvd_span_singleton, ←
Associates.le_singleton_iff,
Associates.prime_pow_dvd_iff_le (Associates.mk_ne_zero'.mpr hr)
(by apply v.associates_irreducible)]
#align is_dedekind_domain.height_one_spectrum.int_valuation_le_pow_iff_dvd IsDedekindDomain.HeightOneSpectrum.int_valuation_le_pow_iff_dvd
theorem IntValuation.map_zero' : v.intValuationDef 0 = 0 :=
v.intValuationDef_if_pos (Eq.refl 0)
#align is_dedekind_domain.height_one_spectrum.int_valuation.map_zero' IsDedekindDomain.HeightOneSpectrum.IntValuation.map_zero'
theorem IntValuation.map_one' : v.intValuationDef 1 = 1 := by
rw [v.intValuationDef_if_neg (zero_ne_one.symm : (1 : R) ≠ 0), Ideal.span_singleton_one, ←
Ideal.one_eq_top, Associates.mk_one, Associates.factors_one,
Associates.count_zero (by apply v.associates_irreducible), Int.ofNat_zero, neg_zero, ofAdd_zero,
WithZero.coe_one]
#align is_dedekind_domain.height_one_spectrum.int_valuation.map_one' IsDedekindDomain.HeightOneSpectrum.IntValuation.map_one'
| Mathlib/RingTheory/DedekindDomain/AdicValuation.lean | 164 | 175 | theorem IntValuation.map_mul' (x y : R) :
v.intValuationDef (x * y) = v.intValuationDef x * v.intValuationDef y := by |
simp only [intValuationDef]
by_cases hx : x = 0
· rw [hx, zero_mul, if_pos (Eq.refl _), zero_mul]
· by_cases hy : y = 0
· rw [hy, mul_zero, if_pos (Eq.refl _), mul_zero]
· rw [if_neg hx, if_neg hy, if_neg (mul_ne_zero hx hy), ← WithZero.coe_mul, WithZero.coe_inj, ←
ofAdd_add, ← Ideal.span_singleton_mul_span_singleton, ← Associates.mk_mul_mk, ← neg_add,
Associates.count_mul (by apply Associates.mk_ne_zero'.mpr hx)
(by apply Associates.mk_ne_zero'.mpr hy) (by apply v.associates_irreducible)]
rfl
|
import Mathlib.CategoryTheory.Preadditive.AdditiveFunctor
import Mathlib.CategoryTheory.Monoidal.Functor
#align_import category_theory.monoidal.preadditive from "leanprover-community/mathlib"@"986c4d5761f938b2e1c43c01f001b6d9d88c2055"
noncomputable section
open scoped Classical
namespace CategoryTheory
open CategoryTheory.Limits
open CategoryTheory.MonoidalCategory
variable (C : Type*) [Category C] [Preadditive C] [MonoidalCategory C]
class MonoidalPreadditive : Prop where
whiskerLeft_zero : ∀ {X Y Z : C}, X ◁ (0 : Y ⟶ Z) = 0 := by aesop_cat
zero_whiskerRight : ∀ {X Y Z : C}, (0 : Y ⟶ Z) ▷ X = 0 := by aesop_cat
whiskerLeft_add : ∀ {X Y Z : C} (f g : Y ⟶ Z), X ◁ (f + g) = X ◁ f + X ◁ g := by aesop_cat
add_whiskerRight : ∀ {X Y Z : C} (f g : Y ⟶ Z), (f + g) ▷ X = f ▷ X + g ▷ X := by aesop_cat
#align category_theory.monoidal_preadditive CategoryTheory.MonoidalPreadditive
attribute [simp] MonoidalPreadditive.whiskerLeft_zero MonoidalPreadditive.zero_whiskerRight
attribute [simp] MonoidalPreadditive.whiskerLeft_add MonoidalPreadditive.add_whiskerRight
variable {C}
variable [MonoidalPreadditive C]
namespace MonoidalPreadditive
-- The priority setting will not be needed when we replace `𝟙 X ⊗ f` by `X ◁ f`.
@[simp (low)]
| Mathlib/CategoryTheory/Monoidal/Preadditive.lean | 52 | 53 | theorem tensor_zero {W X Y Z : C} (f : W ⟶ X) : f ⊗ (0 : Y ⟶ Z) = 0 := by |
simp [tensorHom_def]
|
import Mathlib.LinearAlgebra.Quotient
import Mathlib.RingTheory.Congruence
import Mathlib.RingTheory.Ideal.Basic
import Mathlib.Tactic.FinCases
#align_import ring_theory.ideal.quotient from "leanprover-community/mathlib"@"949dc57e616a621462062668c9f39e4e17b64b69"
universe u v w
namespace Ideal
open Set
variable {R : Type u} [CommRing R] (I : Ideal R) {a b : R}
variable {S : Type v}
-- Note that at present `Ideal` means a left-ideal,
-- so this quotient is only useful in a commutative ring.
-- We should develop quotients by two-sided ideals as well.
@[instance] abbrev instHasQuotient : HasQuotient R (Ideal R) :=
Submodule.hasQuotient
namespace Quotient
variable {I} {x y : R}
instance one (I : Ideal R) : One (R ⧸ I) :=
⟨Submodule.Quotient.mk 1⟩
#align ideal.quotient.has_one Ideal.Quotient.one
protected def ringCon (I : Ideal R) : RingCon R :=
{ QuotientAddGroup.con I.toAddSubgroup with
mul' := fun {a₁ b₁ a₂ b₂} h₁ h₂ => by
rw [Submodule.quotientRel_r_def] at h₁ h₂ ⊢
have F := I.add_mem (I.mul_mem_left a₂ h₁) (I.mul_mem_right b₁ h₂)
have : a₁ * a₂ - b₁ * b₂ = a₂ * (a₁ - b₁) + (a₂ - b₂) * b₁ := by
rw [mul_sub, sub_mul, sub_add_sub_cancel, mul_comm, mul_comm b₁]
rwa [← this] at F }
#align ideal.quotient.ring_con Ideal.Quotient.ringCon
instance commRing (I : Ideal R) : CommRing (R ⧸ I) :=
inferInstanceAs (CommRing (Quotient.ringCon I).Quotient)
#align ideal.quotient.comm_ring Ideal.Quotient.commRing
-- Sanity test to make sure no diamonds have emerged in `commRing`
example : (commRing I).toAddCommGroup = Submodule.Quotient.addCommGroup I := rfl
-- this instance is harder to find than the one via `Algebra α (R ⧸ I)`, so use a lower priority
instance (priority := 100) isScalarTower_right {α} [SMul α R] [IsScalarTower α R R] :
IsScalarTower α (R ⧸ I) (R ⧸ I) :=
(Quotient.ringCon I).isScalarTower_right
#align ideal.quotient.is_scalar_tower_right Ideal.Quotient.isScalarTower_right
instance smulCommClass {α} [SMul α R] [IsScalarTower α R R] [SMulCommClass α R R] :
SMulCommClass α (R ⧸ I) (R ⧸ I) :=
(Quotient.ringCon I).smulCommClass
#align ideal.quotient.smul_comm_class Ideal.Quotient.smulCommClass
instance smulCommClass' {α} [SMul α R] [IsScalarTower α R R] [SMulCommClass R α R] :
SMulCommClass (R ⧸ I) α (R ⧸ I) :=
(Quotient.ringCon I).smulCommClass'
#align ideal.quotient.smul_comm_class' Ideal.Quotient.smulCommClass'
def mk (I : Ideal R) : R →+* R ⧸ I where
toFun a := Submodule.Quotient.mk a
map_zero' := rfl
map_one' := rfl
map_mul' _ _ := rfl
map_add' _ _ := rfl
#align ideal.quotient.mk Ideal.Quotient.mk
instance {I : Ideal R} : Coe R (R ⧸ I) :=
⟨Ideal.Quotient.mk I⟩
@[ext 1100]
theorem ringHom_ext [NonAssocSemiring S] ⦃f g : R ⧸ I →+* S⦄ (h : f.comp (mk I) = g.comp (mk I)) :
f = g :=
RingHom.ext fun x => Quotient.inductionOn' x <| (RingHom.congr_fun h : _)
#align ideal.quotient.ring_hom_ext Ideal.Quotient.ringHom_ext
instance inhabited : Inhabited (R ⧸ I) :=
⟨mk I 37⟩
#align ideal.quotient.inhabited Ideal.Quotient.inhabited
protected theorem eq : mk I x = mk I y ↔ x - y ∈ I :=
Submodule.Quotient.eq I
#align ideal.quotient.eq Ideal.Quotient.eq
@[simp]
theorem mk_eq_mk (x : R) : (Submodule.Quotient.mk x : R ⧸ I) = mk I x := rfl
#align ideal.quotient.mk_eq_mk Ideal.Quotient.mk_eq_mk
theorem eq_zero_iff_mem {I : Ideal R} : mk I a = 0 ↔ a ∈ I :=
Submodule.Quotient.mk_eq_zero _
#align ideal.quotient.eq_zero_iff_mem Ideal.Quotient.eq_zero_iff_mem
theorem eq_zero_iff_dvd (x y : R) : Ideal.Quotient.mk (Ideal.span ({x} : Set R)) y = 0 ↔ x ∣ y := by
rw [Ideal.Quotient.eq_zero_iff_mem, Ideal.mem_span_singleton]
@[simp]
lemma mk_singleton_self (x : R) : mk (Ideal.span {x}) x = 0 := by
rw [eq_zero_iff_dvd]
-- Porting note (#10756): new theorem
theorem mk_eq_mk_iff_sub_mem (x y : R) : mk I x = mk I y ↔ x - y ∈ I := by
rw [← eq_zero_iff_mem, map_sub, sub_eq_zero]
theorem zero_eq_one_iff {I : Ideal R} : (0 : R ⧸ I) = 1 ↔ I = ⊤ :=
eq_comm.trans <| eq_zero_iff_mem.trans (eq_top_iff_one _).symm
#align ideal.quotient.zero_eq_one_iff Ideal.Quotient.zero_eq_one_iff
theorem zero_ne_one_iff {I : Ideal R} : (0 : R ⧸ I) ≠ 1 ↔ I ≠ ⊤ :=
not_congr zero_eq_one_iff
#align ideal.quotient.zero_ne_one_iff Ideal.Quotient.zero_ne_one_iff
protected theorem nontrivial {I : Ideal R} (hI : I ≠ ⊤) : Nontrivial (R ⧸ I) :=
⟨⟨0, 1, zero_ne_one_iff.2 hI⟩⟩
#align ideal.quotient.nontrivial Ideal.Quotient.nontrivial
theorem subsingleton_iff {I : Ideal R} : Subsingleton (R ⧸ I) ↔ I = ⊤ := by
rw [eq_top_iff_one, ← subsingleton_iff_zero_eq_one, eq_comm, ← (mk I).map_one,
Quotient.eq_zero_iff_mem]
#align ideal.quotient.subsingleton_iff Ideal.Quotient.subsingleton_iff
instance : Unique (R ⧸ (⊤ : Ideal R)) :=
⟨⟨0⟩, by rintro ⟨x⟩; exact Quotient.eq_zero_iff_mem.mpr Submodule.mem_top⟩
theorem mk_surjective : Function.Surjective (mk I) := fun y =>
Quotient.inductionOn' y fun x => Exists.intro x rfl
#align ideal.quotient.mk_surjective Ideal.Quotient.mk_surjective
instance : RingHomSurjective (mk I) :=
⟨mk_surjective⟩
theorem quotient_ring_saturate (I : Ideal R) (s : Set R) :
mk I ⁻¹' (mk I '' s) = ⋃ x : I, (fun y => x.1 + y) '' s := by
ext x
simp only [mem_preimage, mem_image, mem_iUnion, Ideal.Quotient.eq]
exact
⟨fun ⟨a, a_in, h⟩ => ⟨⟨_, I.neg_mem h⟩, a, a_in, by simp⟩, fun ⟨⟨i, hi⟩, a, ha, Eq⟩ =>
⟨a, ha, by rw [← Eq, sub_add_eq_sub_sub_swap, sub_self, zero_sub]; exact I.neg_mem hi⟩⟩
#align ideal.quotient.quotient_ring_saturate Ideal.Quotient.quotient_ring_saturate
instance noZeroDivisors (I : Ideal R) [hI : I.IsPrime] : NoZeroDivisors (R ⧸ I) where
eq_zero_or_eq_zero_of_mul_eq_zero {a b} := Quotient.inductionOn₂' a b fun {_ _} hab =>
(hI.mem_or_mem (eq_zero_iff_mem.1 hab)).elim (Or.inl ∘ eq_zero_iff_mem.2)
(Or.inr ∘ eq_zero_iff_mem.2)
#align ideal.quotient.no_zero_divisors Ideal.Quotient.noZeroDivisors
instance isDomain (I : Ideal R) [hI : I.IsPrime] : IsDomain (R ⧸ I) :=
let _ := Quotient.nontrivial hI.1
NoZeroDivisors.to_isDomain _
#align ideal.quotient.is_domain Ideal.Quotient.isDomain
theorem isDomain_iff_prime (I : Ideal R) : IsDomain (R ⧸ I) ↔ I.IsPrime := by
refine ⟨fun H => ⟨zero_ne_one_iff.1 ?_, fun {x y} h => ?_⟩, fun h => inferInstance⟩
· haveI : Nontrivial (R ⧸ I) := ⟨H.2.1⟩
exact zero_ne_one
· simp only [← eq_zero_iff_mem, (mk I).map_mul] at h ⊢
haveI := @IsDomain.to_noZeroDivisors (R ⧸ I) _ H
exact eq_zero_or_eq_zero_of_mul_eq_zero h
#align ideal.quotient.is_domain_iff_prime Ideal.Quotient.isDomain_iff_prime
theorem exists_inv {I : Ideal R} [hI : I.IsMaximal] :
∀ {a : R ⧸ I}, a ≠ 0 → ∃ b : R ⧸ I, a * b = 1 := by
rintro ⟨a⟩ h
rcases hI.exists_inv (mt eq_zero_iff_mem.2 h) with ⟨b, c, hc, abc⟩
rw [mul_comm] at abc
refine ⟨mk _ b, Quot.sound ?_⟩
simp only [Submodule.quotientRel_r_def]
rw [← eq_sub_iff_add_eq'] at abc
rwa [abc, ← neg_mem_iff (G := R) (H := I), neg_sub] at hc
#align ideal.quotient.exists_inv Ideal.Quotient.exists_inv
open scoped Classical
protected noncomputable abbrev groupWithZero (I : Ideal R) [hI : I.IsMaximal] :
GroupWithZero (R ⧸ I) :=
{ inv := fun a => if ha : a = 0 then 0 else Classical.choose (exists_inv ha)
mul_inv_cancel := fun a (ha : a ≠ 0) =>
show a * dite _ _ _ = _ by rw [dif_neg ha]; exact Classical.choose_spec (exists_inv ha)
inv_zero := dif_pos rfl }
#align ideal.quotient.group_with_zero Ideal.Quotient.groupWithZero
protected noncomputable abbrev field (I : Ideal R) [hI : I.IsMaximal] : Field (R ⧸ I) where
__ := commRing _
__ := Quotient.groupWithZero _
nnqsmul := _
qsmul := _
#align ideal.quotient.field Ideal.Quotient.field
theorem maximal_of_isField (I : Ideal R) (hqf : IsField (R ⧸ I)) : I.IsMaximal := by
apply Ideal.isMaximal_iff.2
constructor
· intro h
rcases hqf.exists_pair_ne with ⟨⟨x⟩, ⟨y⟩, hxy⟩
exact hxy (Ideal.Quotient.eq.2 (mul_one (x - y) ▸ I.mul_mem_left _ h))
· intro J x hIJ hxnI hxJ
rcases hqf.mul_inv_cancel (mt Ideal.Quotient.eq_zero_iff_mem.1 hxnI) with ⟨⟨y⟩, hy⟩
rw [← zero_add (1 : R), ← sub_self (x * y), sub_add]
exact J.sub_mem (J.mul_mem_right _ hxJ) (hIJ (Ideal.Quotient.eq.1 hy))
#align ideal.quotient.maximal_of_is_field Ideal.Quotient.maximal_of_isField
theorem maximal_ideal_iff_isField_quotient (I : Ideal R) : I.IsMaximal ↔ IsField (R ⧸ I) :=
⟨fun h =>
let _i := @Quotient.field _ _ I h
Field.toIsField _,
maximal_of_isField _⟩
#align ideal.quotient.maximal_ideal_iff_is_field_quotient Ideal.Quotient.maximal_ideal_iff_isField_quotient
variable [Semiring S]
def lift (I : Ideal R) (f : R →+* S) (H : ∀ a : R, a ∈ I → f a = 0) : R ⧸ I →+* S :=
{ QuotientAddGroup.lift I.toAddSubgroup f.toAddMonoidHom H with
map_one' := f.map_one
map_mul' := fun a₁ a₂ => Quotient.inductionOn₂' a₁ a₂ f.map_mul }
#align ideal.quotient.lift Ideal.Quotient.lift
@[simp]
theorem lift_mk (I : Ideal R) (f : R →+* S) (H : ∀ a : R, a ∈ I → f a = 0) :
lift I f H (mk I a) = f a :=
rfl
#align ideal.quotient.lift_mk Ideal.Quotient.lift_mk
| Mathlib/RingTheory/Ideal/Quotient.lean | 271 | 276 | theorem lift_surjective_of_surjective (I : Ideal R) {f : R →+* S} (H : ∀ a : R, a ∈ I → f a = 0)
(hf : Function.Surjective f) : Function.Surjective (Ideal.Quotient.lift I f H) := by |
intro y
obtain ⟨x, rfl⟩ := hf y
use Ideal.Quotient.mk I x
simp only [Ideal.Quotient.lift_mk]
|
import Mathlib.Topology.Compactness.SigmaCompact
import Mathlib.Topology.Connected.TotallyDisconnected
import Mathlib.Topology.Inseparable
#align_import topology.separation from "leanprover-community/mathlib"@"d91e7f7a7f1c7e9f0e18fdb6bde4f652004c735d"
open Function Set Filter Topology TopologicalSpace
open scoped Classical
universe u v
variable {X : Type*} {Y : Type*} [TopologicalSpace X]
section Separation
def SeparatedNhds : Set X → Set X → Prop := fun s t : Set X =>
∃ U V : Set X, IsOpen U ∧ IsOpen V ∧ s ⊆ U ∧ t ⊆ V ∧ Disjoint U V
#align separated_nhds SeparatedNhds
theorem separatedNhds_iff_disjoint {s t : Set X} : SeparatedNhds s t ↔ Disjoint (𝓝ˢ s) (𝓝ˢ t) := by
simp only [(hasBasis_nhdsSet s).disjoint_iff (hasBasis_nhdsSet t), SeparatedNhds, exists_prop, ←
exists_and_left, and_assoc, and_comm, and_left_comm]
#align separated_nhds_iff_disjoint separatedNhds_iff_disjoint
alias ⟨SeparatedNhds.disjoint_nhdsSet, _⟩ := separatedNhds_iff_disjoint
class T0Space (X : Type u) [TopologicalSpace X] : Prop where
t0 : ∀ ⦃x y : X⦄, Inseparable x y → x = y
#align t0_space T0Space
theorem t0Space_iff_inseparable (X : Type u) [TopologicalSpace X] :
T0Space X ↔ ∀ x y : X, Inseparable x y → x = y :=
⟨fun ⟨h⟩ => h, fun h => ⟨h⟩⟩
#align t0_space_iff_inseparable t0Space_iff_inseparable
theorem t0Space_iff_not_inseparable (X : Type u) [TopologicalSpace X] :
T0Space X ↔ Pairwise fun x y : X => ¬Inseparable x y := by
simp only [t0Space_iff_inseparable, Ne, not_imp_not, Pairwise]
#align t0_space_iff_not_inseparable t0Space_iff_not_inseparable
theorem Inseparable.eq [T0Space X] {x y : X} (h : Inseparable x y) : x = y :=
T0Space.t0 h
#align inseparable.eq Inseparable.eq
protected theorem Inducing.injective [TopologicalSpace Y] [T0Space X] {f : X → Y}
(hf : Inducing f) : Injective f := fun _ _ h =>
(hf.inseparable_iff.1 <| .of_eq h).eq
#align inducing.injective Inducing.injective
protected theorem Inducing.embedding [TopologicalSpace Y] [T0Space X] {f : X → Y}
(hf : Inducing f) : Embedding f :=
⟨hf, hf.injective⟩
#align inducing.embedding Inducing.embedding
lemma embedding_iff_inducing [TopologicalSpace Y] [T0Space X] {f : X → Y} :
Embedding f ↔ Inducing f :=
⟨Embedding.toInducing, Inducing.embedding⟩
#align embedding_iff_inducing embedding_iff_inducing
theorem t0Space_iff_nhds_injective (X : Type u) [TopologicalSpace X] :
T0Space X ↔ Injective (𝓝 : X → Filter X) :=
t0Space_iff_inseparable X
#align t0_space_iff_nhds_injective t0Space_iff_nhds_injective
theorem nhds_injective [T0Space X] : Injective (𝓝 : X → Filter X) :=
(t0Space_iff_nhds_injective X).1 ‹_›
#align nhds_injective nhds_injective
theorem inseparable_iff_eq [T0Space X] {x y : X} : Inseparable x y ↔ x = y :=
nhds_injective.eq_iff
#align inseparable_iff_eq inseparable_iff_eq
@[simp]
theorem nhds_eq_nhds_iff [T0Space X] {a b : X} : 𝓝 a = 𝓝 b ↔ a = b :=
nhds_injective.eq_iff
#align nhds_eq_nhds_iff nhds_eq_nhds_iff
@[simp]
theorem inseparable_eq_eq [T0Space X] : Inseparable = @Eq X :=
funext₂ fun _ _ => propext inseparable_iff_eq
#align inseparable_eq_eq inseparable_eq_eq
theorem TopologicalSpace.IsTopologicalBasis.inseparable_iff {b : Set (Set X)}
(hb : IsTopologicalBasis b) {x y : X} : Inseparable x y ↔ ∀ s ∈ b, (x ∈ s ↔ y ∈ s) :=
⟨fun h s hs ↦ inseparable_iff_forall_open.1 h _ (hb.isOpen hs),
fun h ↦ hb.nhds_hasBasis.eq_of_same_basis <| by
convert hb.nhds_hasBasis using 2
exact and_congr_right (h _)⟩
theorem TopologicalSpace.IsTopologicalBasis.eq_iff [T0Space X] {b : Set (Set X)}
(hb : IsTopologicalBasis b) {x y : X} : x = y ↔ ∀ s ∈ b, (x ∈ s ↔ y ∈ s) :=
inseparable_iff_eq.symm.trans hb.inseparable_iff
theorem t0Space_iff_exists_isOpen_xor'_mem (X : Type u) [TopologicalSpace X] :
T0Space X ↔ Pairwise fun x y => ∃ U : Set X, IsOpen U ∧ Xor' (x ∈ U) (y ∈ U) := by
simp only [t0Space_iff_not_inseparable, xor_iff_not_iff, not_forall, exists_prop,
inseparable_iff_forall_open, Pairwise]
#align t0_space_iff_exists_is_open_xor_mem t0Space_iff_exists_isOpen_xor'_mem
theorem exists_isOpen_xor'_mem [T0Space X] {x y : X} (h : x ≠ y) :
∃ U : Set X, IsOpen U ∧ Xor' (x ∈ U) (y ∈ U) :=
(t0Space_iff_exists_isOpen_xor'_mem X).1 ‹_› h
#align exists_is_open_xor_mem exists_isOpen_xor'_mem
def specializationOrder (X) [TopologicalSpace X] [T0Space X] : PartialOrder X :=
{ specializationPreorder X, PartialOrder.lift (OrderDual.toDual ∘ 𝓝) nhds_injective with }
#align specialization_order specializationOrder
instance SeparationQuotient.instT0Space : T0Space (SeparationQuotient X) :=
⟨fun x y => Quotient.inductionOn₂' x y fun _ _ h =>
SeparationQuotient.mk_eq_mk.2 <| SeparationQuotient.inducing_mk.inseparable_iff.1 h⟩
theorem minimal_nonempty_closed_subsingleton [T0Space X] {s : Set X} (hs : IsClosed s)
(hmin : ∀ t, t ⊆ s → t.Nonempty → IsClosed t → t = s) : s.Subsingleton := by
clear Y -- Porting note: added
refine fun x hx y hy => of_not_not fun hxy => ?_
rcases exists_isOpen_xor'_mem hxy with ⟨U, hUo, hU⟩
wlog h : x ∈ U ∧ y ∉ U
· refine this hs hmin y hy x hx (Ne.symm hxy) U hUo hU.symm (hU.resolve_left h)
cases' h with hxU hyU
have : s \ U = s := hmin (s \ U) diff_subset ⟨y, hy, hyU⟩ (hs.sdiff hUo)
exact (this.symm.subset hx).2 hxU
#align minimal_nonempty_closed_subsingleton minimal_nonempty_closed_subsingleton
theorem minimal_nonempty_closed_eq_singleton [T0Space X] {s : Set X} (hs : IsClosed s)
(hne : s.Nonempty) (hmin : ∀ t, t ⊆ s → t.Nonempty → IsClosed t → t = s) : ∃ x, s = {x} :=
exists_eq_singleton_iff_nonempty_subsingleton.2
⟨hne, minimal_nonempty_closed_subsingleton hs hmin⟩
#align minimal_nonempty_closed_eq_singleton minimal_nonempty_closed_eq_singleton
theorem IsClosed.exists_closed_singleton [T0Space X] [CompactSpace X] {S : Set X}
(hS : IsClosed S) (hne : S.Nonempty) : ∃ x : X, x ∈ S ∧ IsClosed ({x} : Set X) := by
obtain ⟨V, Vsub, Vne, Vcls, hV⟩ := hS.exists_minimal_nonempty_closed_subset hne
rcases minimal_nonempty_closed_eq_singleton Vcls Vne hV with ⟨x, rfl⟩
exact ⟨x, Vsub (mem_singleton x), Vcls⟩
#align is_closed.exists_closed_singleton IsClosed.exists_closed_singleton
theorem minimal_nonempty_open_subsingleton [T0Space X] {s : Set X} (hs : IsOpen s)
(hmin : ∀ t, t ⊆ s → t.Nonempty → IsOpen t → t = s) : s.Subsingleton := by
clear Y -- Porting note: added
refine fun x hx y hy => of_not_not fun hxy => ?_
rcases exists_isOpen_xor'_mem hxy with ⟨U, hUo, hU⟩
wlog h : x ∈ U ∧ y ∉ U
· exact this hs hmin y hy x hx (Ne.symm hxy) U hUo hU.symm (hU.resolve_left h)
cases' h with hxU hyU
have : s ∩ U = s := hmin (s ∩ U) inter_subset_left ⟨x, hx, hxU⟩ (hs.inter hUo)
exact hyU (this.symm.subset hy).2
#align minimal_nonempty_open_subsingleton minimal_nonempty_open_subsingleton
theorem minimal_nonempty_open_eq_singleton [T0Space X] {s : Set X} (hs : IsOpen s)
(hne : s.Nonempty) (hmin : ∀ t, t ⊆ s → t.Nonempty → IsOpen t → t = s) : ∃ x, s = {x} :=
exists_eq_singleton_iff_nonempty_subsingleton.2 ⟨hne, minimal_nonempty_open_subsingleton hs hmin⟩
#align minimal_nonempty_open_eq_singleton minimal_nonempty_open_eq_singleton
theorem exists_isOpen_singleton_of_isOpen_finite [T0Space X] {s : Set X} (hfin : s.Finite)
(hne : s.Nonempty) (ho : IsOpen s) : ∃ x ∈ s, IsOpen ({x} : Set X) := by
lift s to Finset X using hfin
induction' s using Finset.strongInductionOn with s ihs
rcases em (∃ t, t ⊂ s ∧ t.Nonempty ∧ IsOpen (t : Set X)) with (⟨t, hts, htne, hto⟩ | ht)
· rcases ihs t hts htne hto with ⟨x, hxt, hxo⟩
exact ⟨x, hts.1 hxt, hxo⟩
· -- Porting note: was `rcases minimal_nonempty_open_eq_singleton ho hne _ with ⟨x, hx⟩`
-- https://github.com/leanprover/std4/issues/116
rsuffices ⟨x, hx⟩ : ∃ x, s.toSet = {x}
· exact ⟨x, hx.symm ▸ rfl, hx ▸ ho⟩
refine minimal_nonempty_open_eq_singleton ho hne ?_
refine fun t hts htne hto => of_not_not fun hts' => ht ?_
lift t to Finset X using s.finite_toSet.subset hts
exact ⟨t, ssubset_iff_subset_ne.2 ⟨hts, mt Finset.coe_inj.2 hts'⟩, htne, hto⟩
#align exists_open_singleton_of_open_finite exists_isOpen_singleton_of_isOpen_finite
theorem exists_open_singleton_of_finite [T0Space X] [Finite X] [Nonempty X] :
∃ x : X, IsOpen ({x} : Set X) :=
let ⟨x, _, h⟩ := exists_isOpen_singleton_of_isOpen_finite (Set.toFinite _)
univ_nonempty isOpen_univ
⟨x, h⟩
#align exists_open_singleton_of_fintype exists_open_singleton_of_finite
theorem t0Space_of_injective_of_continuous [TopologicalSpace Y] {f : X → Y}
(hf : Function.Injective f) (hf' : Continuous f) [T0Space Y] : T0Space X :=
⟨fun _ _ h => hf <| (h.map hf').eq⟩
#align t0_space_of_injective_of_continuous t0Space_of_injective_of_continuous
protected theorem Embedding.t0Space [TopologicalSpace Y] [T0Space Y] {f : X → Y}
(hf : Embedding f) : T0Space X :=
t0Space_of_injective_of_continuous hf.inj hf.continuous
#align embedding.t0_space Embedding.t0Space
instance Subtype.t0Space [T0Space X] {p : X → Prop} : T0Space (Subtype p) :=
embedding_subtype_val.t0Space
#align subtype.t0_space Subtype.t0Space
theorem t0Space_iff_or_not_mem_closure (X : Type u) [TopologicalSpace X] :
T0Space X ↔ Pairwise fun a b : X => a ∉ closure ({b} : Set X) ∨ b ∉ closure ({a} : Set X) := by
simp only [t0Space_iff_not_inseparable, inseparable_iff_mem_closure, not_and_or]
#align t0_space_iff_or_not_mem_closure t0Space_iff_or_not_mem_closure
instance Prod.instT0Space [TopologicalSpace Y] [T0Space X] [T0Space Y] : T0Space (X × Y) :=
⟨fun _ _ h => Prod.ext (h.map continuous_fst).eq (h.map continuous_snd).eq⟩
instance Pi.instT0Space {ι : Type*} {X : ι → Type*} [∀ i, TopologicalSpace (X i)]
[∀ i, T0Space (X i)] :
T0Space (∀ i, X i) :=
⟨fun _ _ h => funext fun i => (h.map (continuous_apply i)).eq⟩
#align pi.t0_space Pi.instT0Space
instance ULift.instT0Space [T0Space X] : T0Space (ULift X) :=
embedding_uLift_down.t0Space
theorem T0Space.of_cover (h : ∀ x y, Inseparable x y → ∃ s : Set X, x ∈ s ∧ y ∈ s ∧ T0Space s) :
T0Space X := by
refine ⟨fun x y hxy => ?_⟩
rcases h x y hxy with ⟨s, hxs, hys, hs⟩
lift x to s using hxs; lift y to s using hys
rw [← subtype_inseparable_iff] at hxy
exact congr_arg Subtype.val hxy.eq
#align t0_space.of_cover T0Space.of_cover
theorem T0Space.of_open_cover (h : ∀ x, ∃ s : Set X, x ∈ s ∧ IsOpen s ∧ T0Space s) : T0Space X :=
T0Space.of_cover fun x _ hxy =>
let ⟨s, hxs, hso, hs⟩ := h x
⟨s, hxs, (hxy.mem_open_iff hso).1 hxs, hs⟩
#align t0_space.of_open_cover T0Space.of_open_cover
@[mk_iff]
class R0Space (X : Type u) [TopologicalSpace X] : Prop where
specializes_symmetric : Symmetric (Specializes : X → X → Prop)
export R0Space (specializes_symmetric)
class T1Space (X : Type u) [TopologicalSpace X] : Prop where
t1 : ∀ x, IsClosed ({x} : Set X)
#align t1_space T1Space
theorem isClosed_singleton [T1Space X] {x : X} : IsClosed ({x} : Set X) :=
T1Space.t1 x
#align is_closed_singleton isClosed_singleton
theorem isOpen_compl_singleton [T1Space X] {x : X} : IsOpen ({x}ᶜ : Set X) :=
isClosed_singleton.isOpen_compl
#align is_open_compl_singleton isOpen_compl_singleton
theorem isOpen_ne [T1Space X] {x : X} : IsOpen { y | y ≠ x } :=
isOpen_compl_singleton
#align is_open_ne isOpen_ne
@[to_additive]
theorem Continuous.isOpen_mulSupport [T1Space X] [One X] [TopologicalSpace Y] {f : Y → X}
(hf : Continuous f) : IsOpen (mulSupport f) :=
isOpen_ne.preimage hf
#align continuous.is_open_mul_support Continuous.isOpen_mulSupport
#align continuous.is_open_support Continuous.isOpen_support
theorem Ne.nhdsWithin_compl_singleton [T1Space X] {x y : X} (h : x ≠ y) : 𝓝[{y}ᶜ] x = 𝓝 x :=
isOpen_ne.nhdsWithin_eq h
#align ne.nhds_within_compl_singleton Ne.nhdsWithin_compl_singleton
theorem Ne.nhdsWithin_diff_singleton [T1Space X] {x y : X} (h : x ≠ y) (s : Set X) :
𝓝[s \ {y}] x = 𝓝[s] x := by
rw [diff_eq, inter_comm, nhdsWithin_inter_of_mem]
exact mem_nhdsWithin_of_mem_nhds (isOpen_ne.mem_nhds h)
#align ne.nhds_within_diff_singleton Ne.nhdsWithin_diff_singleton
lemma nhdsWithin_compl_singleton_le [T1Space X] (x y : X) : 𝓝[{x}ᶜ] x ≤ 𝓝[{y}ᶜ] x := by
rcases eq_or_ne x y with rfl|hy
· exact Eq.le rfl
· rw [Ne.nhdsWithin_compl_singleton hy]
exact nhdsWithin_le_nhds
theorem isOpen_setOf_eventually_nhdsWithin [T1Space X] {p : X → Prop} :
IsOpen { x | ∀ᶠ y in 𝓝[≠] x, p y } := by
refine isOpen_iff_mem_nhds.mpr fun a ha => ?_
filter_upwards [eventually_nhds_nhdsWithin.mpr ha] with b hb
rcases eq_or_ne a b with rfl | h
· exact hb
· rw [h.symm.nhdsWithin_compl_singleton] at hb
exact hb.filter_mono nhdsWithin_le_nhds
#align is_open_set_of_eventually_nhds_within isOpen_setOf_eventually_nhdsWithin
protected theorem Set.Finite.isClosed [T1Space X] {s : Set X} (hs : Set.Finite s) : IsClosed s := by
rw [← biUnion_of_singleton s]
exact hs.isClosed_biUnion fun i _ => isClosed_singleton
#align set.finite.is_closed Set.Finite.isClosed
theorem TopologicalSpace.IsTopologicalBasis.exists_mem_of_ne [T1Space X] {b : Set (Set X)}
(hb : IsTopologicalBasis b) {x y : X} (h : x ≠ y) : ∃ a ∈ b, x ∈ a ∧ y ∉ a := by
rcases hb.isOpen_iff.1 isOpen_ne x h with ⟨a, ab, xa, ha⟩
exact ⟨a, ab, xa, fun h => ha h rfl⟩
#align topological_space.is_topological_basis.exists_mem_of_ne TopologicalSpace.IsTopologicalBasis.exists_mem_of_ne
protected theorem Finset.isClosed [T1Space X] (s : Finset X) : IsClosed (s : Set X) :=
s.finite_toSet.isClosed
#align finset.is_closed Finset.isClosed
theorem t1Space_TFAE (X : Type u) [TopologicalSpace X] :
List.TFAE [T1Space X,
∀ x, IsClosed ({ x } : Set X),
∀ x, IsOpen ({ x }ᶜ : Set X),
Continuous (@CofiniteTopology.of X),
∀ ⦃x y : X⦄, x ≠ y → {y}ᶜ ∈ 𝓝 x,
∀ ⦃x y : X⦄, x ≠ y → ∃ s ∈ 𝓝 x, y ∉ s,
∀ ⦃x y : X⦄, x ≠ y → ∃ U : Set X, IsOpen U ∧ x ∈ U ∧ y ∉ U,
∀ ⦃x y : X⦄, x ≠ y → Disjoint (𝓝 x) (pure y),
∀ ⦃x y : X⦄, x ≠ y → Disjoint (pure x) (𝓝 y),
∀ ⦃x y : X⦄, x ⤳ y → x = y] := by
tfae_have 1 ↔ 2
· exact ⟨fun h => h.1, fun h => ⟨h⟩⟩
tfae_have 2 ↔ 3
· simp only [isOpen_compl_iff]
tfae_have 5 ↔ 3
· refine forall_swap.trans ?_
simp only [isOpen_iff_mem_nhds, mem_compl_iff, mem_singleton_iff]
tfae_have 5 ↔ 6
· simp only [← subset_compl_singleton_iff, exists_mem_subset_iff]
tfae_have 5 ↔ 7
· simp only [(nhds_basis_opens _).mem_iff, subset_compl_singleton_iff, exists_prop, and_assoc,
and_left_comm]
tfae_have 5 ↔ 8
· simp only [← principal_singleton, disjoint_principal_right]
tfae_have 8 ↔ 9
· exact forall_swap.trans (by simp only [disjoint_comm, ne_comm])
tfae_have 1 → 4
· simp only [continuous_def, CofiniteTopology.isOpen_iff']
rintro H s (rfl | hs)
exacts [isOpen_empty, compl_compl s ▸ (@Set.Finite.isClosed _ _ H _ hs).isOpen_compl]
tfae_have 4 → 2
· exact fun h x => (CofiniteTopology.isClosed_iff.2 <| Or.inr (finite_singleton _)).preimage h
tfae_have 2 ↔ 10
· simp only [← closure_subset_iff_isClosed, specializes_iff_mem_closure, subset_def,
mem_singleton_iff, eq_comm]
tfae_finish
#align t1_space_tfae t1Space_TFAE
theorem t1Space_iff_continuous_cofinite_of : T1Space X ↔ Continuous (@CofiniteTopology.of X) :=
(t1Space_TFAE X).out 0 3
#align t1_space_iff_continuous_cofinite_of t1Space_iff_continuous_cofinite_of
theorem CofiniteTopology.continuous_of [T1Space X] : Continuous (@CofiniteTopology.of X) :=
t1Space_iff_continuous_cofinite_of.mp ‹_›
#align cofinite_topology.continuous_of CofiniteTopology.continuous_of
theorem t1Space_iff_exists_open :
T1Space X ↔ Pairwise fun x y => ∃ U : Set X, IsOpen U ∧ x ∈ U ∧ y ∉ U :=
(t1Space_TFAE X).out 0 6
#align t1_space_iff_exists_open t1Space_iff_exists_open
theorem t1Space_iff_disjoint_pure_nhds : T1Space X ↔ ∀ ⦃x y : X⦄, x ≠ y → Disjoint (pure x) (𝓝 y) :=
(t1Space_TFAE X).out 0 8
#align t1_space_iff_disjoint_pure_nhds t1Space_iff_disjoint_pure_nhds
theorem t1Space_iff_disjoint_nhds_pure : T1Space X ↔ ∀ ⦃x y : X⦄, x ≠ y → Disjoint (𝓝 x) (pure y) :=
(t1Space_TFAE X).out 0 7
#align t1_space_iff_disjoint_nhds_pure t1Space_iff_disjoint_nhds_pure
theorem t1Space_iff_specializes_imp_eq : T1Space X ↔ ∀ ⦃x y : X⦄, x ⤳ y → x = y :=
(t1Space_TFAE X).out 0 9
#align t1_space_iff_specializes_imp_eq t1Space_iff_specializes_imp_eq
theorem disjoint_pure_nhds [T1Space X] {x y : X} (h : x ≠ y) : Disjoint (pure x) (𝓝 y) :=
t1Space_iff_disjoint_pure_nhds.mp ‹_› h
#align disjoint_pure_nhds disjoint_pure_nhds
theorem disjoint_nhds_pure [T1Space X] {x y : X} (h : x ≠ y) : Disjoint (𝓝 x) (pure y) :=
t1Space_iff_disjoint_nhds_pure.mp ‹_› h
#align disjoint_nhds_pure disjoint_nhds_pure
theorem Specializes.eq [T1Space X] {x y : X} (h : x ⤳ y) : x = y :=
t1Space_iff_specializes_imp_eq.1 ‹_› h
#align specializes.eq Specializes.eq
theorem specializes_iff_eq [T1Space X] {x y : X} : x ⤳ y ↔ x = y :=
⟨Specializes.eq, fun h => h ▸ specializes_rfl⟩
#align specializes_iff_eq specializes_iff_eq
@[simp] theorem specializes_eq_eq [T1Space X] : (· ⤳ ·) = @Eq X :=
funext₂ fun _ _ => propext specializes_iff_eq
#align specializes_eq_eq specializes_eq_eq
@[simp]
theorem pure_le_nhds_iff [T1Space X] {a b : X} : pure a ≤ 𝓝 b ↔ a = b :=
specializes_iff_pure.symm.trans specializes_iff_eq
#align pure_le_nhds_iff pure_le_nhds_iff
@[simp]
theorem nhds_le_nhds_iff [T1Space X] {a b : X} : 𝓝 a ≤ 𝓝 b ↔ a = b :=
specializes_iff_eq
#align nhds_le_nhds_iff nhds_le_nhds_iff
instance (priority := 100) [T1Space X] : R0Space X where
specializes_symmetric _ _ := by rw [specializes_iff_eq, specializes_iff_eq]; exact Eq.symm
instance : T1Space (CofiniteTopology X) :=
t1Space_iff_continuous_cofinite_of.mpr continuous_id
theorem t1Space_antitone : Antitone (@T1Space X) := fun a _ h _ =>
@T1Space.mk _ a fun x => (T1Space.t1 x).mono h
#align t1_space_antitone t1Space_antitone
theorem continuousWithinAt_update_of_ne [T1Space X] [DecidableEq X] [TopologicalSpace Y] {f : X → Y}
{s : Set X} {x x' : X} {y : Y} (hne : x' ≠ x) :
ContinuousWithinAt (Function.update f x y) s x' ↔ ContinuousWithinAt f s x' :=
EventuallyEq.congr_continuousWithinAt
(mem_nhdsWithin_of_mem_nhds <| mem_of_superset (isOpen_ne.mem_nhds hne) fun _y' hy' =>
Function.update_noteq hy' _ _)
(Function.update_noteq hne _ _)
#align continuous_within_at_update_of_ne continuousWithinAt_update_of_ne
theorem continuousAt_update_of_ne [T1Space X] [DecidableEq X] [TopologicalSpace Y]
{f : X → Y} {x x' : X} {y : Y} (hne : x' ≠ x) :
ContinuousAt (Function.update f x y) x' ↔ ContinuousAt f x' := by
simp only [← continuousWithinAt_univ, continuousWithinAt_update_of_ne hne]
#align continuous_at_update_of_ne continuousAt_update_of_ne
theorem continuousOn_update_iff [T1Space X] [DecidableEq X] [TopologicalSpace Y] {f : X → Y}
{s : Set X} {x : X} {y : Y} :
ContinuousOn (Function.update f x y) s ↔
ContinuousOn f (s \ {x}) ∧ (x ∈ s → Tendsto f (𝓝[s \ {x}] x) (𝓝 y)) := by
rw [ContinuousOn, ← and_forall_ne x, and_comm]
refine and_congr ⟨fun H z hz => ?_, fun H z hzx hzs => ?_⟩ (forall_congr' fun _ => ?_)
· specialize H z hz.2 hz.1
rw [continuousWithinAt_update_of_ne hz.2] at H
exact H.mono diff_subset
· rw [continuousWithinAt_update_of_ne hzx]
refine (H z ⟨hzs, hzx⟩).mono_of_mem (inter_mem_nhdsWithin _ ?_)
exact isOpen_ne.mem_nhds hzx
· exact continuousWithinAt_update_same
#align continuous_on_update_iff continuousOn_update_iff
theorem t1Space_of_injective_of_continuous [TopologicalSpace Y] {f : X → Y}
(hf : Function.Injective f) (hf' : Continuous f) [T1Space Y] : T1Space X :=
t1Space_iff_specializes_imp_eq.2 fun _ _ h => hf (h.map hf').eq
#align t1_space_of_injective_of_continuous t1Space_of_injective_of_continuous
protected theorem Embedding.t1Space [TopologicalSpace Y] [T1Space Y] {f : X → Y}
(hf : Embedding f) : T1Space X :=
t1Space_of_injective_of_continuous hf.inj hf.continuous
#align embedding.t1_space Embedding.t1Space
instance Subtype.t1Space {X : Type u} [TopologicalSpace X] [T1Space X] {p : X → Prop} :
T1Space (Subtype p) :=
embedding_subtype_val.t1Space
#align subtype.t1_space Subtype.t1Space
instance [TopologicalSpace Y] [T1Space X] [T1Space Y] : T1Space (X × Y) :=
⟨fun ⟨a, b⟩ => @singleton_prod_singleton _ _ a b ▸ isClosed_singleton.prod isClosed_singleton⟩
instance {ι : Type*} {X : ι → Type*} [∀ i, TopologicalSpace (X i)] [∀ i, T1Space (X i)] :
T1Space (∀ i, X i) :=
⟨fun f => univ_pi_singleton f ▸ isClosed_set_pi fun _ _ => isClosed_singleton⟩
instance ULift.instT1Space [T1Space X] : T1Space (ULift X) :=
embedding_uLift_down.t1Space
-- see Note [lower instance priority]
instance (priority := 100) TotallyDisconnectedSpace.t1Space [h: TotallyDisconnectedSpace X] :
T1Space X := by
rw [((t1Space_TFAE X).out 0 1 :)]
intro x
rw [← totallyDisconnectedSpace_iff_connectedComponent_singleton.mp h x]
exact isClosed_connectedComponent
-- see Note [lower instance priority]
instance (priority := 100) T1Space.t0Space [T1Space X] : T0Space X :=
⟨fun _ _ h => h.specializes.eq⟩
#align t1_space.t0_space T1Space.t0Space
@[simp]
theorem compl_singleton_mem_nhds_iff [T1Space X] {x y : X} : {x}ᶜ ∈ 𝓝 y ↔ y ≠ x :=
isOpen_compl_singleton.mem_nhds_iff
#align compl_singleton_mem_nhds_iff compl_singleton_mem_nhds_iff
theorem compl_singleton_mem_nhds [T1Space X] {x y : X} (h : y ≠ x) : {x}ᶜ ∈ 𝓝 y :=
compl_singleton_mem_nhds_iff.mpr h
#align compl_singleton_mem_nhds compl_singleton_mem_nhds
@[simp]
theorem closure_singleton [T1Space X] {x : X} : closure ({x} : Set X) = {x} :=
isClosed_singleton.closure_eq
#align closure_singleton closure_singleton
-- Porting note (#11215): TODO: the proof was `hs.induction_on (by simp) fun x => by simp`
theorem Set.Subsingleton.closure [T1Space X] {s : Set X} (hs : s.Subsingleton) :
(closure s).Subsingleton := by
rcases hs.eq_empty_or_singleton with (rfl | ⟨x, rfl⟩) <;> simp
#align set.subsingleton.closure Set.Subsingleton.closure
@[simp]
theorem subsingleton_closure [T1Space X] {s : Set X} : (closure s).Subsingleton ↔ s.Subsingleton :=
⟨fun h => h.anti subset_closure, fun h => h.closure⟩
#align subsingleton_closure subsingleton_closure
theorem isClosedMap_const {X Y} [TopologicalSpace X] [TopologicalSpace Y] [T1Space Y] {y : Y} :
IsClosedMap (Function.const X y) :=
IsClosedMap.of_nonempty fun s _ h2s => by simp_rw [const, h2s.image_const, isClosed_singleton]
#align is_closed_map_const isClosedMap_const
theorem nhdsWithin_insert_of_ne [T1Space X] {x y : X} {s : Set X} (hxy : x ≠ y) :
𝓝[insert y s] x = 𝓝[s] x := by
refine le_antisymm (Filter.le_def.2 fun t ht => ?_) (nhdsWithin_mono x <| subset_insert y s)
obtain ⟨o, ho, hxo, host⟩ := mem_nhdsWithin.mp ht
refine mem_nhdsWithin.mpr ⟨o \ {y}, ho.sdiff isClosed_singleton, ⟨hxo, hxy⟩, ?_⟩
rw [inter_insert_of_not_mem <| not_mem_diff_of_mem (mem_singleton y)]
exact (inter_subset_inter diff_subset Subset.rfl).trans host
#align nhds_within_insert_of_ne nhdsWithin_insert_of_ne
theorem insert_mem_nhdsWithin_of_subset_insert [T1Space X] {x y : X} {s t : Set X}
(hu : t ⊆ insert y s) : insert x s ∈ 𝓝[t] x := by
rcases eq_or_ne x y with (rfl | h)
· exact mem_of_superset self_mem_nhdsWithin hu
refine nhdsWithin_mono x hu ?_
rw [nhdsWithin_insert_of_ne h]
exact mem_of_superset self_mem_nhdsWithin (subset_insert x s)
#align insert_mem_nhds_within_of_subset_insert insert_mem_nhdsWithin_of_subset_insert
@[simp]
theorem ker_nhds [T1Space X] (x : X) : (𝓝 x).ker = {x} := by
simp [ker_nhds_eq_specializes]
theorem biInter_basis_nhds [T1Space X] {ι : Sort*} {p : ι → Prop} {s : ι → Set X} {x : X}
(h : (𝓝 x).HasBasis p s) : ⋂ (i) (_ : p i), s i = {x} := by
rw [← h.ker, ker_nhds]
#align bInter_basis_nhds biInter_basis_nhds
@[simp]
theorem compl_singleton_mem_nhdsSet_iff [T1Space X] {x : X} {s : Set X} : {x}ᶜ ∈ 𝓝ˢ s ↔ x ∉ s := by
rw [isOpen_compl_singleton.mem_nhdsSet, subset_compl_singleton_iff]
#align compl_singleton_mem_nhds_set_iff compl_singleton_mem_nhdsSet_iff
@[simp]
theorem nhdsSet_le_iff [T1Space X] {s t : Set X} : 𝓝ˢ s ≤ 𝓝ˢ t ↔ s ⊆ t := by
refine ⟨?_, fun h => monotone_nhdsSet h⟩
simp_rw [Filter.le_def]; intro h x hx
specialize h {x}ᶜ
simp_rw [compl_singleton_mem_nhdsSet_iff] at h
by_contra hxt
exact h hxt hx
#align nhds_set_le_iff nhdsSet_le_iff
@[simp]
theorem nhdsSet_inj_iff [T1Space X] {s t : Set X} : 𝓝ˢ s = 𝓝ˢ t ↔ s = t := by
simp_rw [le_antisymm_iff]
exact and_congr nhdsSet_le_iff nhdsSet_le_iff
#align nhds_set_inj_iff nhdsSet_inj_iff
theorem injective_nhdsSet [T1Space X] : Function.Injective (𝓝ˢ : Set X → Filter X) := fun _ _ hst =>
nhdsSet_inj_iff.mp hst
#align injective_nhds_set injective_nhdsSet
theorem strictMono_nhdsSet [T1Space X] : StrictMono (𝓝ˢ : Set X → Filter X) :=
monotone_nhdsSet.strictMono_of_injective injective_nhdsSet
#align strict_mono_nhds_set strictMono_nhdsSet
@[simp]
theorem nhds_le_nhdsSet_iff [T1Space X] {s : Set X} {x : X} : 𝓝 x ≤ 𝓝ˢ s ↔ x ∈ s := by
rw [← nhdsSet_singleton, nhdsSet_le_iff, singleton_subset_iff]
#align nhds_le_nhds_set_iff nhds_le_nhdsSet_iff
theorem Dense.diff_singleton [T1Space X] {s : Set X} (hs : Dense s) (x : X) [NeBot (𝓝[≠] x)] :
Dense (s \ {x}) :=
hs.inter_of_isOpen_right (dense_compl_singleton x) isOpen_compl_singleton
#align dense.diff_singleton Dense.diff_singleton
theorem Dense.diff_finset [T1Space X] [∀ x : X, NeBot (𝓝[≠] x)] {s : Set X} (hs : Dense s)
(t : Finset X) : Dense (s \ t) := by
induction t using Finset.induction_on with
| empty => simpa using hs
| insert _ ih =>
rw [Finset.coe_insert, ← union_singleton, ← diff_diff]
exact ih.diff_singleton _
#align dense.diff_finset Dense.diff_finset
theorem Dense.diff_finite [T1Space X] [∀ x : X, NeBot (𝓝[≠] x)] {s : Set X} (hs : Dense s)
{t : Set X} (ht : t.Finite) : Dense (s \ t) := by
convert hs.diff_finset ht.toFinset
exact (Finite.coe_toFinset _).symm
#align dense.diff_finite Dense.diff_finite
theorem eq_of_tendsto_nhds [TopologicalSpace Y] [T1Space Y] {f : X → Y} {x : X} {y : Y}
(h : Tendsto f (𝓝 x) (𝓝 y)) : f x = y :=
by_contra fun hfa : f x ≠ y =>
have fact₁ : {f x}ᶜ ∈ 𝓝 y := compl_singleton_mem_nhds hfa.symm
have fact₂ : Tendsto f (pure x) (𝓝 y) := h.comp (tendsto_id'.2 <| pure_le_nhds x)
fact₂ fact₁ (Eq.refl <| f x)
#align eq_of_tendsto_nhds eq_of_tendsto_nhds
theorem Filter.Tendsto.eventually_ne [TopologicalSpace Y] [T1Space Y] {g : X → Y}
{l : Filter X} {b₁ b₂ : Y} (hg : Tendsto g l (𝓝 b₁)) (hb : b₁ ≠ b₂) : ∀ᶠ z in l, g z ≠ b₂ :=
hg.eventually (isOpen_compl_singleton.eventually_mem hb)
#align filter.tendsto.eventually_ne Filter.Tendsto.eventually_ne
theorem ContinuousAt.eventually_ne [TopologicalSpace Y] [T1Space Y] {g : X → Y} {x : X} {y : Y}
(hg1 : ContinuousAt g x) (hg2 : g x ≠ y) : ∀ᶠ z in 𝓝 x, g z ≠ y :=
hg1.tendsto.eventually_ne hg2
#align continuous_at.eventually_ne ContinuousAt.eventually_ne
theorem eventually_ne_nhds [T1Space X] {a b : X} (h : a ≠ b) : ∀ᶠ x in 𝓝 a, x ≠ b :=
IsOpen.eventually_mem isOpen_ne h
theorem eventually_ne_nhdsWithin [T1Space X] {a b : X} {s : Set X} (h : a ≠ b) :
∀ᶠ x in 𝓝[s] a, x ≠ b :=
Filter.Eventually.filter_mono nhdsWithin_le_nhds <| eventually_ne_nhds h
theorem continuousAt_of_tendsto_nhds [TopologicalSpace Y] [T1Space Y] {f : X → Y} {x : X} {y : Y}
(h : Tendsto f (𝓝 x) (𝓝 y)) : ContinuousAt f x := by
rwa [ContinuousAt, eq_of_tendsto_nhds h]
#align continuous_at_of_tendsto_nhds continuousAt_of_tendsto_nhds
@[simp]
theorem tendsto_const_nhds_iff [T1Space X] {l : Filter Y} [NeBot l] {c d : X} :
Tendsto (fun _ => c) l (𝓝 d) ↔ c = d := by simp_rw [Tendsto, Filter.map_const, pure_le_nhds_iff]
#align tendsto_const_nhds_iff tendsto_const_nhds_iff
theorem isOpen_singleton_of_finite_mem_nhds [T1Space X] (x : X)
{s : Set X} (hs : s ∈ 𝓝 x) (hsf : s.Finite) : IsOpen ({x} : Set X) := by
have A : {x} ⊆ s := by simp only [singleton_subset_iff, mem_of_mem_nhds hs]
have B : IsClosed (s \ {x}) := (hsf.subset diff_subset).isClosed
have C : (s \ {x})ᶜ ∈ 𝓝 x := B.isOpen_compl.mem_nhds fun h => h.2 rfl
have D : {x} ∈ 𝓝 x := by simpa only [← diff_eq, diff_diff_cancel_left A] using inter_mem hs C
rwa [← mem_interior_iff_mem_nhds, ← singleton_subset_iff, subset_interior_iff_isOpen] at D
#align is_open_singleton_of_finite_mem_nhds isOpen_singleton_of_finite_mem_nhds
theorem infinite_of_mem_nhds {X} [TopologicalSpace X] [T1Space X] (x : X) [hx : NeBot (𝓝[≠] x)]
{s : Set X} (hs : s ∈ 𝓝 x) : Set.Infinite s := by
refine fun hsf => hx.1 ?_
rw [← isOpen_singleton_iff_punctured_nhds]
exact isOpen_singleton_of_finite_mem_nhds x hs hsf
#align infinite_of_mem_nhds infinite_of_mem_nhds
theorem discrete_of_t1_of_finite [T1Space X] [Finite X] :
DiscreteTopology X := by
apply singletons_open_iff_discrete.mp
intro x
rw [← isClosed_compl_iff]
exact (Set.toFinite _).isClosed
#align discrete_of_t1_of_finite discrete_of_t1_of_finite
theorem PreconnectedSpace.trivial_of_discrete [PreconnectedSpace X] [DiscreteTopology X] :
Subsingleton X := by
rw [← not_nontrivial_iff_subsingleton]
rintro ⟨x, y, hxy⟩
rw [Ne, ← mem_singleton_iff, (isClopen_discrete _).eq_univ <| singleton_nonempty y] at hxy
exact hxy (mem_univ x)
#align preconnected_space.trivial_of_discrete PreconnectedSpace.trivial_of_discrete
theorem IsPreconnected.infinite_of_nontrivial [T1Space X] {s : Set X} (h : IsPreconnected s)
(hs : s.Nontrivial) : s.Infinite := by
refine mt (fun hf => (subsingleton_coe s).mp ?_) (not_subsingleton_iff.mpr hs)
haveI := @discrete_of_t1_of_finite s _ _ hf.to_subtype
exact @PreconnectedSpace.trivial_of_discrete _ _ (Subtype.preconnectedSpace h) _
#align is_preconnected.infinite_of_nontrivial IsPreconnected.infinite_of_nontrivial
theorem ConnectedSpace.infinite [ConnectedSpace X] [Nontrivial X] [T1Space X] : Infinite X :=
infinite_univ_iff.mp <| isPreconnected_univ.infinite_of_nontrivial nontrivial_univ
#align connected_space.infinite ConnectedSpace.infinite
instance (priority := 100) ConnectedSpace.neBot_nhdsWithin_compl_of_nontrivial_of_t1space
[ConnectedSpace X] [Nontrivial X] [T1Space X] (x : X) :
NeBot (𝓝[≠] x) := by
by_contra contra
rw [not_neBot, ← isOpen_singleton_iff_punctured_nhds] at contra
replace contra := nonempty_inter isOpen_compl_singleton
contra (compl_union_self _) (Set.nonempty_compl_of_nontrivial _) (singleton_nonempty _)
simp [compl_inter_self {x}] at contra
theorem SeparationQuotient.t1Space_iff : T1Space (SeparationQuotient X) ↔ R0Space X := by
rw [r0Space_iff, ((t1Space_TFAE (SeparationQuotient X)).out 0 9 :)]
constructor
· intro h x y xspecy
rw [← Inducing.specializes_iff inducing_mk, h xspecy] at *
· rintro h ⟨x⟩ ⟨y⟩ sxspecsy
have xspecy : x ⤳ y := (Inducing.specializes_iff inducing_mk).mp sxspecsy
have yspecx : y ⤳ x := h xspecy
erw [mk_eq_mk, inseparable_iff_specializes_and]
exact ⟨xspecy, yspecx⟩
theorem singleton_mem_nhdsWithin_of_mem_discrete {s : Set X} [DiscreteTopology s] {x : X}
(hx : x ∈ s) : {x} ∈ 𝓝[s] x := by
have : ({⟨x, hx⟩} : Set s) ∈ 𝓝 (⟨x, hx⟩ : s) := by simp [nhds_discrete]
simpa only [nhdsWithin_eq_map_subtype_coe hx, image_singleton] using
@image_mem_map _ _ _ ((↑) : s → X) _ this
#align singleton_mem_nhds_within_of_mem_discrete singleton_mem_nhdsWithin_of_mem_discrete
theorem nhdsWithin_of_mem_discrete {s : Set X} [DiscreteTopology s] {x : X} (hx : x ∈ s) :
𝓝[s] x = pure x :=
le_antisymm (le_pure_iff.2 <| singleton_mem_nhdsWithin_of_mem_discrete hx) (pure_le_nhdsWithin hx)
#align nhds_within_of_mem_discrete nhdsWithin_of_mem_discrete
theorem Filter.HasBasis.exists_inter_eq_singleton_of_mem_discrete {ι : Type*} {p : ι → Prop}
{t : ι → Set X} {s : Set X} [DiscreteTopology s] {x : X} (hb : (𝓝 x).HasBasis p t)
(hx : x ∈ s) : ∃ i, p i ∧ t i ∩ s = {x} := by
rcases (nhdsWithin_hasBasis hb s).mem_iff.1 (singleton_mem_nhdsWithin_of_mem_discrete hx) with
⟨i, hi, hix⟩
exact ⟨i, hi, hix.antisymm <| singleton_subset_iff.2 ⟨mem_of_mem_nhds <| hb.mem_of_mem hi, hx⟩⟩
#align filter.has_basis.exists_inter_eq_singleton_of_mem_discrete Filter.HasBasis.exists_inter_eq_singleton_of_mem_discrete
theorem nhds_inter_eq_singleton_of_mem_discrete {s : Set X} [DiscreteTopology s] {x : X}
(hx : x ∈ s) : ∃ U ∈ 𝓝 x, U ∩ s = {x} := by
simpa using (𝓝 x).basis_sets.exists_inter_eq_singleton_of_mem_discrete hx
#align nhds_inter_eq_singleton_of_mem_discrete nhds_inter_eq_singleton_of_mem_discrete
theorem isOpen_inter_eq_singleton_of_mem_discrete {s : Set X} [DiscreteTopology s] {x : X}
(hx : x ∈ s) : ∃ U : Set X, IsOpen U ∧ U ∩ s = {x} := by
obtain ⟨U, hU_nhds, hU_inter⟩ := nhds_inter_eq_singleton_of_mem_discrete hx
obtain ⟨t, ht_sub, ht_open, ht_x⟩ := mem_nhds_iff.mp hU_nhds
refine ⟨t, ht_open, Set.Subset.antisymm ?_ ?_⟩
· exact hU_inter ▸ Set.inter_subset_inter_left s ht_sub
· rw [Set.subset_inter_iff, Set.singleton_subset_iff, Set.singleton_subset_iff]
exact ⟨ht_x, hx⟩
theorem disjoint_nhdsWithin_of_mem_discrete {s : Set X} [DiscreteTopology s] {x : X} (hx : x ∈ s) :
∃ U ∈ 𝓝[≠] x, Disjoint U s :=
let ⟨V, h, h'⟩ := nhds_inter_eq_singleton_of_mem_discrete hx
⟨{x}ᶜ ∩ V, inter_mem_nhdsWithin _ h,
disjoint_iff_inter_eq_empty.mpr (by rw [inter_assoc, h', compl_inter_self])⟩
#align disjoint_nhds_within_of_mem_discrete disjoint_nhdsWithin_of_mem_discrete
@[deprecated embedding_inclusion (since := "2023-02-02")]
theorem TopologicalSpace.subset_trans {s t : Set X} (ts : t ⊆ s) :
(instTopologicalSpaceSubtype : TopologicalSpace t) =
(instTopologicalSpaceSubtype : TopologicalSpace s).induced (Set.inclusion ts) :=
(embedding_inclusion ts).induced
#align topological_space.subset_trans TopologicalSpace.subset_trans
@[mk_iff]
class T2Space (X : Type u) [TopologicalSpace X] : Prop where
t2 : Pairwise fun x y => ∃ u v : Set X, IsOpen u ∧ IsOpen v ∧ x ∈ u ∧ y ∈ v ∧ Disjoint u v
#align t2_space T2Space
theorem t2_separation [T2Space X] {x y : X} (h : x ≠ y) :
∃ u v : Set X, IsOpen u ∧ IsOpen v ∧ x ∈ u ∧ y ∈ v ∧ Disjoint u v :=
T2Space.t2 h
#align t2_separation t2_separation
-- todo: use this as a definition?
| Mathlib/Topology/Separation.lean | 1,305 | 1,308 | theorem t2Space_iff_disjoint_nhds : T2Space X ↔ Pairwise fun x y : X => Disjoint (𝓝 x) (𝓝 y) := by |
refine (t2Space_iff X).trans (forall₃_congr fun x y _ => ?_)
simp only [(nhds_basis_opens x).disjoint_iff (nhds_basis_opens y), exists_prop, ← exists_and_left,
and_assoc, and_comm, and_left_comm]
|
import Mathlib.Topology.ContinuousFunction.Bounded
import Mathlib.Topology.Sets.Compacts
#align_import measure_theory.integral.riesz_markov_kakutani from "leanprover-community/mathlib"@"b2ff9a3d7a15fd5b0f060b135421d6a89a999c2f"
noncomputable section
open BoundedContinuousFunction NNReal ENNReal
open Set Function TopologicalSpace
variable {X : Type*} [TopologicalSpace X]
variable (Λ : (X →ᵇ ℝ≥0) →ₗ[ℝ≥0] ℝ≥0)
def rieszContentAux : Compacts X → ℝ≥0 := fun K =>
sInf (Λ '' { f : X →ᵇ ℝ≥0 | ∀ x ∈ K, (1 : ℝ≥0) ≤ f x })
#align riesz_content_aux rieszContentAux
section RieszMonotone
| Mathlib/MeasureTheory/Integral/RieszMarkovKakutani.lean | 51 | 56 | theorem rieszContentAux_image_nonempty (K : Compacts X) :
(Λ '' { f : X →ᵇ ℝ≥0 | ∀ x ∈ K, (1 : ℝ≥0) ≤ f x }).Nonempty := by |
rw [image_nonempty]
use (1 : X →ᵇ ℝ≥0)
intro x _
simp only [BoundedContinuousFunction.coe_one, Pi.one_apply]; rfl
|
import Mathlib.Algebra.EuclideanDomain.Defs
import Mathlib.Algebra.Ring.Divisibility.Basic
import Mathlib.Algebra.Ring.Regular
import Mathlib.Algebra.GroupWithZero.Divisibility
import Mathlib.Algebra.Ring.Basic
#align_import algebra.euclidean_domain.basic from "leanprover-community/mathlib"@"bf9bbbcf0c1c1ead18280b0d010e417b10abb1b6"
universe u
namespace EuclideanDomain
variable {R : Type u}
variable [EuclideanDomain R]
local infixl:50 " ≺ " => EuclideanDomain.R
-- See note [lower instance priority]
instance (priority := 100) toMulDivCancelClass : MulDivCancelClass R where
mul_div_cancel a b hb := by
refine (eq_of_sub_eq_zero ?_).symm
by_contra h
have := mul_right_not_lt b h
rw [sub_mul, mul_comm (_ / _), sub_eq_iff_eq_add'.2 (div_add_mod (a * b) b).symm] at this
exact this (mod_lt _ hb)
#align euclidean_domain.mul_div_cancel_left mul_div_cancel_left₀
#align euclidean_domain.mul_div_cancel mul_div_cancel_right₀
@[simp]
theorem mod_eq_zero {a b : R} : a % b = 0 ↔ b ∣ a :=
⟨fun h => by
rw [← div_add_mod a b, h, add_zero]
exact dvd_mul_right _ _, fun ⟨c, e⟩ => by
rw [e, ← add_left_cancel_iff, div_add_mod, add_zero]
haveI := Classical.dec
by_cases b0 : b = 0
· simp only [b0, zero_mul]
· rw [mul_div_cancel_left₀ _ b0]⟩
#align euclidean_domain.mod_eq_zero EuclideanDomain.mod_eq_zero
@[simp]
theorem mod_self (a : R) : a % a = 0 :=
mod_eq_zero.2 dvd_rfl
#align euclidean_domain.mod_self EuclideanDomain.mod_self
theorem dvd_mod_iff {a b c : R} (h : c ∣ b) : c ∣ a % b ↔ c ∣ a := by
rw [← dvd_add_right (h.mul_right _), div_add_mod]
#align euclidean_domain.dvd_mod_iff EuclideanDomain.dvd_mod_iff
@[simp]
theorem mod_one (a : R) : a % 1 = 0 :=
mod_eq_zero.2 (one_dvd _)
#align euclidean_domain.mod_one EuclideanDomain.mod_one
@[simp]
theorem zero_mod (b : R) : 0 % b = 0 :=
mod_eq_zero.2 (dvd_zero _)
#align euclidean_domain.zero_mod EuclideanDomain.zero_mod
@[simp]
theorem zero_div {a : R} : 0 / a = 0 :=
by_cases (fun a0 : a = 0 => a0.symm ▸ div_zero 0) fun a0 => by
simpa only [zero_mul] using mul_div_cancel_right₀ 0 a0
#align euclidean_domain.zero_div EuclideanDomain.zero_div
@[simp]
theorem div_self {a : R} (a0 : a ≠ 0) : a / a = 1 := by
simpa only [one_mul] using mul_div_cancel_right₀ 1 a0
#align euclidean_domain.div_self EuclideanDomain.div_self
theorem eq_div_of_mul_eq_left {a b c : R} (hb : b ≠ 0) (h : a * b = c) : a = c / b := by
rw [← h, mul_div_cancel_right₀ _ hb]
#align euclidean_domain.eq_div_of_mul_eq_left EuclideanDomain.eq_div_of_mul_eq_left
theorem eq_div_of_mul_eq_right {a b c : R} (ha : a ≠ 0) (h : a * b = c) : b = c / a := by
rw [← h, mul_div_cancel_left₀ _ ha]
#align euclidean_domain.eq_div_of_mul_eq_right EuclideanDomain.eq_div_of_mul_eq_right
theorem mul_div_assoc (x : R) {y z : R} (h : z ∣ y) : x * y / z = x * (y / z) := by
by_cases hz : z = 0
· subst hz
rw [div_zero, div_zero, mul_zero]
rcases h with ⟨p, rfl⟩
rw [mul_div_cancel_left₀ _ hz, mul_left_comm, mul_div_cancel_left₀ _ hz]
#align euclidean_domain.mul_div_assoc EuclideanDomain.mul_div_assoc
protected theorem mul_div_cancel' {a b : R} (hb : b ≠ 0) (hab : b ∣ a) : b * (a / b) = a := by
rw [← mul_div_assoc _ hab, mul_div_cancel_left₀ _ hb]
#align euclidean_domain.mul_div_cancel' EuclideanDomain.mul_div_cancel'
-- This generalizes `Int.div_one`, see note [simp-normal form]
@[simp]
theorem div_one (p : R) : p / 1 = p :=
(EuclideanDomain.eq_div_of_mul_eq_left (one_ne_zero' R) (mul_one p)).symm
#align euclidean_domain.div_one EuclideanDomain.div_one
theorem div_dvd_of_dvd {p q : R} (hpq : q ∣ p) : p / q ∣ p := by
by_cases hq : q = 0
· rw [hq, zero_dvd_iff] at hpq
rw [hpq]
exact dvd_zero _
use q
rw [mul_comm, ← EuclideanDomain.mul_div_assoc _ hpq, mul_comm, mul_div_cancel_right₀ _ hq]
#align euclidean_domain.div_dvd_of_dvd EuclideanDomain.div_dvd_of_dvd
theorem dvd_div_of_mul_dvd {a b c : R} (h : a * b ∣ c) : b ∣ c / a := by
rcases eq_or_ne a 0 with (rfl | ha)
· simp only [div_zero, dvd_zero]
rcases h with ⟨d, rfl⟩
refine ⟨d, ?_⟩
rw [mul_assoc, mul_div_cancel_left₀ _ ha]
#align euclidean_domain.dvd_div_of_mul_dvd EuclideanDomain.dvd_div_of_mul_dvd
section GCD
variable [DecidableEq R]
@[simp]
theorem gcd_zero_right (a : R) : gcd a 0 = a := by
rw [gcd]
split_ifs with h <;> simp only [h, zero_mod, gcd_zero_left]
#align euclidean_domain.gcd_zero_right EuclideanDomain.gcd_zero_right
| Mathlib/Algebra/EuclideanDomain/Basic.lean | 141 | 143 | theorem gcd_val (a b : R) : gcd a b = gcd (b % a) a := by |
rw [gcd]
split_ifs with h <;> [simp only [h, mod_zero, gcd_zero_right]; rfl]
|
import Mathlib.Data.Fintype.List
#align_import data.list.cycle from "leanprover-community/mathlib"@"7413128c3bcb3b0818e3e18720abc9ea3100fb49"
assert_not_exists MonoidWithZero
open List
def Cycle (α : Type*) : Type _ :=
Quotient (IsRotated.setoid α)
#align cycle Cycle
namespace Cycle
variable {α : Type*}
-- Porting note (#11445): new definition
@[coe] def ofList : List α → Cycle α :=
Quot.mk _
instance : Coe (List α) (Cycle α) :=
⟨ofList⟩
@[simp]
theorem coe_eq_coe {l₁ l₂ : List α} : (l₁ : Cycle α) = (l₂ : Cycle α) ↔ l₁ ~r l₂ :=
@Quotient.eq _ (IsRotated.setoid _) _ _
#align cycle.coe_eq_coe Cycle.coe_eq_coe
@[simp]
theorem mk_eq_coe (l : List α) : Quot.mk _ l = (l : Cycle α) :=
rfl
#align cycle.mk_eq_coe Cycle.mk_eq_coe
@[simp]
theorem mk''_eq_coe (l : List α) : Quotient.mk'' l = (l : Cycle α) :=
rfl
#align cycle.mk'_eq_coe Cycle.mk''_eq_coe
theorem coe_cons_eq_coe_append (l : List α) (a : α) :
(↑(a :: l) : Cycle α) = (↑(l ++ [a]) : Cycle α) :=
Quot.sound ⟨1, by rw [rotate_cons_succ, rotate_zero]⟩
#align cycle.coe_cons_eq_coe_append Cycle.coe_cons_eq_coe_append
def nil : Cycle α :=
([] : List α)
#align cycle.nil Cycle.nil
@[simp]
theorem coe_nil : ↑([] : List α) = @nil α :=
rfl
#align cycle.coe_nil Cycle.coe_nil
@[simp]
theorem coe_eq_nil (l : List α) : (l : Cycle α) = nil ↔ l = [] :=
coe_eq_coe.trans isRotated_nil_iff
#align cycle.coe_eq_nil Cycle.coe_eq_nil
instance : EmptyCollection (Cycle α) :=
⟨nil⟩
@[simp]
theorem empty_eq : ∅ = @nil α :=
rfl
#align cycle.empty_eq Cycle.empty_eq
instance : Inhabited (Cycle α) :=
⟨nil⟩
@[elab_as_elim]
theorem induction_on {C : Cycle α → Prop} (s : Cycle α) (H0 : C nil)
(HI : ∀ (a) (l : List α), C ↑l → C ↑(a :: l)) : C s :=
Quotient.inductionOn' s fun l => by
refine List.recOn l ?_ ?_ <;> simp
assumption'
#align cycle.induction_on Cycle.induction_on
def Mem (a : α) (s : Cycle α) : Prop :=
Quot.liftOn s (fun l => a ∈ l) fun _ _ e => propext <| e.mem_iff
#align cycle.mem Cycle.Mem
instance : Membership α (Cycle α) :=
⟨Mem⟩
@[simp]
theorem mem_coe_iff {a : α} {l : List α} : a ∈ (↑l : Cycle α) ↔ a ∈ l :=
Iff.rfl
#align cycle.mem_coe_iff Cycle.mem_coe_iff
@[simp]
theorem not_mem_nil : ∀ a, a ∉ @nil α :=
List.not_mem_nil
#align cycle.not_mem_nil Cycle.not_mem_nil
instance [DecidableEq α] : DecidableEq (Cycle α) := fun s₁ s₂ =>
Quotient.recOnSubsingleton₂' s₁ s₂ fun _ _ => decidable_of_iff' _ Quotient.eq''
instance [DecidableEq α] (x : α) (s : Cycle α) : Decidable (x ∈ s) :=
Quotient.recOnSubsingleton' s fun l => show Decidable (x ∈ l) from inferInstance
nonrec def reverse (s : Cycle α) : Cycle α :=
Quot.map reverse (fun _ _ => IsRotated.reverse) s
#align cycle.reverse Cycle.reverse
@[simp]
theorem reverse_coe (l : List α) : (l : Cycle α).reverse = l.reverse :=
rfl
#align cycle.reverse_coe Cycle.reverse_coe
@[simp]
theorem mem_reverse_iff {a : α} {s : Cycle α} : a ∈ s.reverse ↔ a ∈ s :=
Quot.inductionOn s fun _ => mem_reverse
#align cycle.mem_reverse_iff Cycle.mem_reverse_iff
@[simp]
theorem reverse_reverse (s : Cycle α) : s.reverse.reverse = s :=
Quot.inductionOn s fun _ => by simp
#align cycle.reverse_reverse Cycle.reverse_reverse
@[simp]
theorem reverse_nil : nil.reverse = @nil α :=
rfl
#align cycle.reverse_nil Cycle.reverse_nil
def length (s : Cycle α) : ℕ :=
Quot.liftOn s List.length fun _ _ e => e.perm.length_eq
#align cycle.length Cycle.length
@[simp]
theorem length_coe (l : List α) : length (l : Cycle α) = l.length :=
rfl
#align cycle.length_coe Cycle.length_coe
@[simp]
theorem length_nil : length (@nil α) = 0 :=
rfl
#align cycle.length_nil Cycle.length_nil
@[simp]
theorem length_reverse (s : Cycle α) : s.reverse.length = s.length :=
Quot.inductionOn s List.length_reverse
#align cycle.length_reverse Cycle.length_reverse
def Subsingleton (s : Cycle α) : Prop :=
s.length ≤ 1
#align cycle.subsingleton Cycle.Subsingleton
theorem subsingleton_nil : Subsingleton (@nil α) := Nat.zero_le _
#align cycle.subsingleton_nil Cycle.subsingleton_nil
theorem length_subsingleton_iff {s : Cycle α} : Subsingleton s ↔ length s ≤ 1 :=
Iff.rfl
#align cycle.length_subsingleton_iff Cycle.length_subsingleton_iff
@[simp]
theorem subsingleton_reverse_iff {s : Cycle α} : s.reverse.Subsingleton ↔ s.Subsingleton := by
simp [length_subsingleton_iff]
#align cycle.subsingleton_reverse_iff Cycle.subsingleton_reverse_iff
theorem Subsingleton.congr {s : Cycle α} (h : Subsingleton s) :
∀ ⦃x⦄ (_hx : x ∈ s) ⦃y⦄ (_hy : y ∈ s), x = y := by
induction' s using Quot.inductionOn with l
simp only [length_subsingleton_iff, length_coe, mk_eq_coe, le_iff_lt_or_eq, Nat.lt_add_one_iff,
length_eq_zero, length_eq_one, Nat.not_lt_zero, false_or_iff] at h
rcases h with (rfl | ⟨z, rfl⟩) <;> simp
#align cycle.subsingleton.congr Cycle.Subsingleton.congr
def Nontrivial (s : Cycle α) : Prop :=
∃ x y : α, x ≠ y ∧ x ∈ s ∧ y ∈ s
#align cycle.nontrivial Cycle.Nontrivial
@[simp]
theorem nontrivial_coe_nodup_iff {l : List α} (hl : l.Nodup) :
Nontrivial (l : Cycle α) ↔ 2 ≤ l.length := by
rw [Nontrivial]
rcases l with (_ | ⟨hd, _ | ⟨hd', tl⟩⟩)
· simp
· simp
· simp only [mem_cons, exists_prop, mem_coe_iff, List.length, Ne, Nat.succ_le_succ_iff,
Nat.zero_le, iff_true_iff]
refine ⟨hd, hd', ?_, by simp⟩
simp only [not_or, mem_cons, nodup_cons] at hl
exact hl.left.left
#align cycle.nontrivial_coe_nodup_iff Cycle.nontrivial_coe_nodup_iff
@[simp]
theorem nontrivial_reverse_iff {s : Cycle α} : s.reverse.Nontrivial ↔ s.Nontrivial := by
simp [Nontrivial]
#align cycle.nontrivial_reverse_iff Cycle.nontrivial_reverse_iff
theorem length_nontrivial {s : Cycle α} (h : Nontrivial s) : 2 ≤ length s := by
obtain ⟨x, y, hxy, hx, hy⟩ := h
induction' s using Quot.inductionOn with l
rcases l with (_ | ⟨hd, _ | ⟨hd', tl⟩⟩)
· simp at hx
· simp only [mem_coe_iff, mk_eq_coe, mem_singleton] at hx hy
simp [hx, hy] at hxy
· simp [Nat.succ_le_succ_iff]
#align cycle.length_nontrivial Cycle.length_nontrivial
nonrec def Nodup (s : Cycle α) : Prop :=
Quot.liftOn s Nodup fun _l₁ _l₂ e => propext <| e.nodup_iff
#align cycle.nodup Cycle.Nodup
@[simp]
nonrec theorem nodup_nil : Nodup (@nil α) :=
nodup_nil
#align cycle.nodup_nil Cycle.nodup_nil
@[simp]
theorem nodup_coe_iff {l : List α} : Nodup (l : Cycle α) ↔ l.Nodup :=
Iff.rfl
#align cycle.nodup_coe_iff Cycle.nodup_coe_iff
@[simp]
theorem nodup_reverse_iff {s : Cycle α} : s.reverse.Nodup ↔ s.Nodup :=
Quot.inductionOn s fun _ => nodup_reverse
#align cycle.nodup_reverse_iff Cycle.nodup_reverse_iff
theorem Subsingleton.nodup {s : Cycle α} (h : Subsingleton s) : Nodup s := by
induction' s using Quot.inductionOn with l
cases' l with hd tl
· simp
· have : tl = [] := by simpa [Subsingleton, length_eq_zero, Nat.succ_le_succ_iff] using h
simp [this]
#align cycle.subsingleton.nodup Cycle.Subsingleton.nodup
theorem Nodup.nontrivial_iff {s : Cycle α} (h : Nodup s) : Nontrivial s ↔ ¬Subsingleton s := by
rw [length_subsingleton_iff]
induction s using Quotient.inductionOn'
simp only [mk''_eq_coe, nodup_coe_iff] at h
simp [h, Nat.succ_le_iff]
#align cycle.nodup.nontrivial_iff Cycle.Nodup.nontrivial_iff
def toMultiset (s : Cycle α) : Multiset α :=
Quotient.liftOn' s (↑) fun _ _ h => Multiset.coe_eq_coe.mpr h.perm
#align cycle.to_multiset Cycle.toMultiset
@[simp]
theorem coe_toMultiset (l : List α) : (l : Cycle α).toMultiset = l :=
rfl
#align cycle.coe_to_multiset Cycle.coe_toMultiset
@[simp]
theorem nil_toMultiset : nil.toMultiset = (0 : Multiset α) :=
rfl
#align cycle.nil_to_multiset Cycle.nil_toMultiset
@[simp]
theorem card_toMultiset (s : Cycle α) : Multiset.card s.toMultiset = s.length :=
Quotient.inductionOn' s (by simp)
#align cycle.card_to_multiset Cycle.card_toMultiset
@[simp]
theorem toMultiset_eq_nil {s : Cycle α} : s.toMultiset = 0 ↔ s = Cycle.nil :=
Quotient.inductionOn' s (by simp)
#align cycle.to_multiset_eq_nil Cycle.toMultiset_eq_nil
def map {β : Type*} (f : α → β) : Cycle α → Cycle β :=
Quotient.map' (List.map f) fun _ _ h => h.map _
#align cycle.map Cycle.map
@[simp]
theorem map_nil {β : Type*} (f : α → β) : map f nil = nil :=
rfl
#align cycle.map_nil Cycle.map_nil
@[simp]
theorem map_coe {β : Type*} (f : α → β) (l : List α) : map f ↑l = List.map f l :=
rfl
#align cycle.map_coe Cycle.map_coe
@[simp]
theorem map_eq_nil {β : Type*} (f : α → β) (s : Cycle α) : map f s = nil ↔ s = nil :=
Quotient.inductionOn' s (by simp)
#align cycle.map_eq_nil Cycle.map_eq_nil
@[simp]
theorem mem_map {β : Type*} {f : α → β} {b : β} {s : Cycle α} :
b ∈ s.map f ↔ ∃ a, a ∈ s ∧ f a = b :=
Quotient.inductionOn' s (by simp)
#align cycle.mem_map Cycle.mem_map
def lists (s : Cycle α) : Multiset (List α) :=
Quotient.liftOn' s (fun l => (l.cyclicPermutations : Multiset (List α))) fun l₁ l₂ h => by
simpa using h.cyclicPermutations.perm
#align cycle.lists Cycle.lists
@[simp]
theorem lists_coe (l : List α) : lists (l : Cycle α) = ↑l.cyclicPermutations :=
rfl
#align cycle.lists_coe Cycle.lists_coe
@[simp]
theorem mem_lists_iff_coe_eq {s : Cycle α} {l : List α} : l ∈ s.lists ↔ (l : Cycle α) = s :=
Quotient.inductionOn' s fun l => by
rw [lists, Quotient.liftOn'_mk'']
simp
#align cycle.mem_lists_iff_coe_eq Cycle.mem_lists_iff_coe_eq
@[simp]
theorem lists_nil : lists (@nil α) = [([] : List α)] := by
rw [nil, lists_coe, cyclicPermutations_nil]
#align cycle.lists_nil Cycle.lists_nil
unsafe instance [Repr α] : Repr (Cycle α) :=
⟨fun s _ => "c[" ++ Std.Format.joinSep (s.map repr).lists.unquot.head! ", " ++ "]"⟩
nonrec def Chain (r : α → α → Prop) (c : Cycle α) : Prop :=
Quotient.liftOn' c
(fun l =>
match l with
| [] => True
| a :: m => Chain r a (m ++ [a]))
fun a b hab =>
propext <| by
cases' a with a l <;> cases' b with b m
· rfl
· have := isRotated_nil_iff'.1 hab
contradiction
· have := isRotated_nil_iff.1 hab
contradiction
· dsimp only
cases' hab with n hn
induction' n with d hd generalizing a b l m
· simp only [Nat.zero_eq, rotate_zero, cons.injEq] at hn
rw [hn.1, hn.2]
· cases' l with c s
· simp only [rotate_cons_succ, nil_append, rotate_singleton, cons.injEq] at hn
rw [hn.1, hn.2]
· rw [Nat.add_comm, ← rotate_rotate, rotate_cons_succ, rotate_zero, cons_append] at hn
rw [← hd c _ _ _ hn]
simp [and_comm]
#align cycle.chain Cycle.Chain
@[simp]
theorem Chain.nil (r : α → α → Prop) : Cycle.Chain r (@nil α) := by trivial
#align cycle.chain.nil Cycle.Chain.nil
@[simp]
theorem chain_coe_cons (r : α → α → Prop) (a : α) (l : List α) :
Chain r (a :: l) ↔ List.Chain r a (l ++ [a]) :=
Iff.rfl
#align cycle.chain_coe_cons Cycle.chain_coe_cons
--@[simp] Porting note (#10618): `simp` can prove it
theorem chain_singleton (r : α → α → Prop) (a : α) : Chain r [a] ↔ r a a := by
rw [chain_coe_cons, nil_append, List.chain_singleton]
#align cycle.chain_singleton Cycle.chain_singleton
theorem chain_ne_nil (r : α → α → Prop) {l : List α} :
∀ hl : l ≠ [], Chain r l ↔ List.Chain r (getLast l hl) l :=
l.reverseRecOn (fun hm => hm.irrefl.elim) (by
intro m a _H _
rw [← coe_cons_eq_coe_append, chain_coe_cons, getLast_append_singleton])
#align cycle.chain_ne_nil Cycle.chain_ne_nil
theorem chain_map {β : Type*} {r : α → α → Prop} (f : β → α) {s : Cycle β} :
Chain r (s.map f) ↔ Chain (fun a b => r (f a) (f b)) s :=
Quotient.inductionOn' s fun l => by
cases' l with a l
· rfl
dsimp only [Chain, ← mk''_eq_coe, Quotient.liftOn'_mk'', Cycle.map, Quotient.map', Quot.map,
Quotient.mk'', Quotient.liftOn', Quotient.liftOn, Quot.liftOn_mk, List.map]
rw [← concat_eq_append, ← List.map_concat, List.chain_map f]
simp
#align cycle.chain_map Cycle.chain_map
nonrec theorem chain_range_succ (r : ℕ → ℕ → Prop) (n : ℕ) :
Chain r (List.range n.succ) ↔ r n 0 ∧ ∀ m < n, r m m.succ := by
rw [range_succ, ← coe_cons_eq_coe_append, chain_coe_cons, ← range_succ, chain_range_succ]
#align cycle.chain_range_succ Cycle.chain_range_succ
variable {r : α → α → Prop} {s : Cycle α}
theorem Chain.imp {r₁ r₂ : α → α → Prop} (H : ∀ a b, r₁ a b → r₂ a b) (p : Chain r₁ s) :
Chain r₂ s := by
induction s using Cycle.induction_on
· trivial
· rw [chain_coe_cons] at p ⊢
exact p.imp H
#align cycle.chain.imp Cycle.Chain.imp
theorem chain_mono : Monotone (Chain : (α → α → Prop) → Cycle α → Prop) := fun _a _b hab _s =>
Chain.imp hab
#align cycle.chain_mono Cycle.chain_mono
theorem chain_of_pairwise : (∀ a ∈ s, ∀ b ∈ s, r a b) → Chain r s := by
induction' s using Cycle.induction_on with a l _
· exact fun _ => Cycle.Chain.nil r
intro hs
have Ha : a ∈ (a :: l : Cycle α) := by simp
have Hl : ∀ {b} (_hb : b ∈ l), b ∈ (a :: l : Cycle α) := @fun b hb => by simp [hb]
rw [Cycle.chain_coe_cons]
apply Pairwise.chain
rw [pairwise_cons]
refine
⟨fun b hb => ?_,
pairwise_append.2
⟨pairwise_of_forall_mem_list fun b hb c hc => hs b (Hl hb) c (Hl hc),
pairwise_singleton r a, fun b hb c hc => ?_⟩⟩
· rw [mem_append] at hb
cases' hb with hb hb
· exact hs a Ha b (Hl hb)
· rw [mem_singleton] at hb
rw [hb]
exact hs a Ha a Ha
· rw [mem_singleton] at hc
rw [hc]
exact hs b (Hl hb) a Ha
#align cycle.chain_of_pairwise Cycle.chain_of_pairwise
theorem chain_iff_pairwise [IsTrans α r] : Chain r s ↔ ∀ a ∈ s, ∀ b ∈ s, r a b :=
⟨by
induction' s using Cycle.induction_on with a l _
· exact fun _ b hb => (not_mem_nil _ hb).elim
intro hs b hb c hc
rw [Cycle.chain_coe_cons, List.chain_iff_pairwise] at hs
simp only [pairwise_append, pairwise_cons, mem_append, mem_singleton, List.not_mem_nil,
IsEmpty.forall_iff, imp_true_iff, Pairwise.nil, forall_eq, true_and_iff] at hs
simp only [mem_coe_iff, mem_cons] at hb hc
rcases hb with (rfl | hb) <;> rcases hc with (rfl | hc)
· exact hs.1 c (Or.inr rfl)
· exact hs.1 c (Or.inl hc)
· exact hs.2.2 b hb
· exact _root_.trans (hs.2.2 b hb) (hs.1 c (Or.inl hc)), Cycle.chain_of_pairwise⟩
#align cycle.chain_iff_pairwise Cycle.chain_iff_pairwise
theorem Chain.eq_nil_of_irrefl [IsTrans α r] [IsIrrefl α r] (h : Chain r s) : s = Cycle.nil := by
induction' s using Cycle.induction_on with a l _ h
· rfl
· have ha := mem_cons_self a l
exact (irrefl_of r a <| chain_iff_pairwise.1 h a ha a ha).elim
#align cycle.chain.eq_nil_of_irrefl Cycle.Chain.eq_nil_of_irrefl
theorem Chain.eq_nil_of_well_founded [IsWellFounded α r] (h : Chain r s) : s = Cycle.nil :=
Chain.eq_nil_of_irrefl <| h.imp fun _ _ => Relation.TransGen.single
#align cycle.chain.eq_nil_of_well_founded Cycle.Chain.eq_nil_of_well_founded
| Mathlib/Data/List/Cycle.lean | 1,034 | 1,037 | theorem forall_eq_of_chain [IsTrans α r] [IsAntisymm α r] (hs : Chain r s) {a b : α} (ha : a ∈ s)
(hb : b ∈ s) : a = b := by |
rw [chain_iff_pairwise] at hs
exact antisymm (hs a ha b hb) (hs b hb a ha)
|
import Mathlib.MeasureTheory.Integral.SetIntegral
import Mathlib.Probability.Independence.Basic
#align_import probability.integration from "leanprover-community/mathlib"@"2f8347015b12b0864dfaf366ec4909eb70c78740"
noncomputable section
open Set MeasureTheory
open scoped ENNReal MeasureTheory
variable {Ω : Type*} {mΩ : MeasurableSpace Ω} {μ : Measure Ω} {f g : Ω → ℝ≥0∞} {X Y : Ω → ℝ}
namespace ProbabilityTheory
theorem lintegral_mul_indicator_eq_lintegral_mul_lintegral_indicator {Mf mΩ : MeasurableSpace Ω}
{μ : Measure Ω} (hMf : Mf ≤ mΩ) (c : ℝ≥0∞) {T : Set Ω} (h_meas_T : MeasurableSet T)
(h_ind : IndepSets {s | MeasurableSet[Mf] s} {T} μ) (h_meas_f : Measurable[Mf] f) :
(∫⁻ ω, f ω * T.indicator (fun _ => c) ω ∂μ) =
(∫⁻ ω, f ω ∂μ) * ∫⁻ ω, T.indicator (fun _ => c) ω ∂μ := by
revert f
have h_mul_indicator : ∀ g, Measurable g → Measurable fun a => g a * T.indicator (fun _ => c) a :=
fun g h_mg => h_mg.mul (measurable_const.indicator h_meas_T)
apply @Measurable.ennreal_induction _ Mf
· intro c' s' h_meas_s'
simp_rw [← inter_indicator_mul]
rw [lintegral_indicator _ (MeasurableSet.inter (hMf _ h_meas_s') h_meas_T),
lintegral_indicator _ (hMf _ h_meas_s'), lintegral_indicator _ h_meas_T]
simp only [measurable_const, lintegral_const, univ_inter, lintegral_const_mul,
MeasurableSet.univ, Measure.restrict_apply]
rw [IndepSets_iff] at h_ind
rw [mul_mul_mul_comm, h_ind s' T h_meas_s' (Set.mem_singleton _)]
· intro f' g _ h_meas_f' _ h_ind_f' h_ind_g
have h_measM_f' : Measurable f' := h_meas_f'.mono hMf le_rfl
simp_rw [Pi.add_apply, right_distrib]
rw [lintegral_add_left (h_mul_indicator _ h_measM_f'), lintegral_add_left h_measM_f',
right_distrib, h_ind_f', h_ind_g]
· intro f h_meas_f h_mono_f h_ind_f
have h_measM_f : ∀ n, Measurable (f n) := fun n => (h_meas_f n).mono hMf le_rfl
simp_rw [ENNReal.iSup_mul]
rw [lintegral_iSup h_measM_f h_mono_f, lintegral_iSup, ENNReal.iSup_mul]
· simp_rw [← h_ind_f]
· exact fun n => h_mul_indicator _ (h_measM_f n)
· exact fun m n h_le a => mul_le_mul_right' (h_mono_f h_le a) _
#align probability_theory.lintegral_mul_indicator_eq_lintegral_mul_lintegral_indicator ProbabilityTheory.lintegral_mul_indicator_eq_lintegral_mul_lintegral_indicator
theorem lintegral_mul_eq_lintegral_mul_lintegral_of_independent_measurableSpace
{Mf Mg mΩ : MeasurableSpace Ω} {μ : Measure Ω} (hMf : Mf ≤ mΩ) (hMg : Mg ≤ mΩ)
(h_ind : Indep Mf Mg μ) (h_meas_f : Measurable[Mf] f) (h_meas_g : Measurable[Mg] g) :
∫⁻ ω, f ω * g ω ∂μ = (∫⁻ ω, f ω ∂μ) * ∫⁻ ω, g ω ∂μ := by
revert g
have h_measM_f : Measurable f := h_meas_f.mono hMf le_rfl
apply @Measurable.ennreal_induction _ Mg
· intro c s h_s
apply lintegral_mul_indicator_eq_lintegral_mul_lintegral_indicator hMf _ (hMg _ h_s) _ h_meas_f
apply indepSets_of_indepSets_of_le_right h_ind
rwa [singleton_subset_iff]
· intro f' g _ h_measMg_f' _ h_ind_f' h_ind_g'
have h_measM_f' : Measurable f' := h_measMg_f'.mono hMg le_rfl
simp_rw [Pi.add_apply, left_distrib]
rw [lintegral_add_left h_measM_f', lintegral_add_left (h_measM_f.mul h_measM_f'), left_distrib,
h_ind_f', h_ind_g']
· intro f' h_meas_f' h_mono_f' h_ind_f'
have h_measM_f' : ∀ n, Measurable (f' n) := fun n => (h_meas_f' n).mono hMg le_rfl
simp_rw [ENNReal.mul_iSup]
rw [lintegral_iSup, lintegral_iSup h_measM_f' h_mono_f', ENNReal.mul_iSup]
· simp_rw [← h_ind_f']
· exact fun n => h_measM_f.mul (h_measM_f' n)
· exact fun n m (h_le : n ≤ m) a => mul_le_mul_left' (h_mono_f' h_le a) _
#align probability_theory.lintegral_mul_eq_lintegral_mul_lintegral_of_independent_measurable_space ProbabilityTheory.lintegral_mul_eq_lintegral_mul_lintegral_of_independent_measurableSpace
theorem lintegral_mul_eq_lintegral_mul_lintegral_of_indepFun (h_meas_f : Measurable f)
(h_meas_g : Measurable g) (h_indep_fun : IndepFun f g μ) :
(∫⁻ ω, (f * g) ω ∂μ) = (∫⁻ ω, f ω ∂μ) * ∫⁻ ω, g ω ∂μ :=
lintegral_mul_eq_lintegral_mul_lintegral_of_independent_measurableSpace
(measurable_iff_comap_le.1 h_meas_f) (measurable_iff_comap_le.1 h_meas_g) h_indep_fun
(Measurable.of_comap_le le_rfl) (Measurable.of_comap_le le_rfl)
#align probability_theory.lintegral_mul_eq_lintegral_mul_lintegral_of_indep_fun ProbabilityTheory.lintegral_mul_eq_lintegral_mul_lintegral_of_indepFun
| Mathlib/Probability/Integration.lean | 120 | 128 | theorem lintegral_mul_eq_lintegral_mul_lintegral_of_indepFun' (h_meas_f : AEMeasurable f μ)
(h_meas_g : AEMeasurable g μ) (h_indep_fun : IndepFun f g μ) :
(∫⁻ ω, (f * g) ω ∂μ) = (∫⁻ ω, f ω ∂μ) * ∫⁻ ω, g ω ∂μ := by |
have fg_ae : f * g =ᵐ[μ] h_meas_f.mk _ * h_meas_g.mk _ := h_meas_f.ae_eq_mk.mul h_meas_g.ae_eq_mk
rw [lintegral_congr_ae h_meas_f.ae_eq_mk, lintegral_congr_ae h_meas_g.ae_eq_mk,
lintegral_congr_ae fg_ae]
apply lintegral_mul_eq_lintegral_mul_lintegral_of_indepFun h_meas_f.measurable_mk
h_meas_g.measurable_mk
exact h_indep_fun.ae_eq h_meas_f.ae_eq_mk h_meas_g.ae_eq_mk
|
import Mathlib.Topology.Order.LeftRight
import Mathlib.Topology.Order.Monotone
#align_import topology.algebra.order.left_right_lim from "leanprover-community/mathlib"@"0a0ec35061ed9960bf0e7ffb0335f44447b58977"
open Set Filter
open Topology
section
variable {α β : Type*} [LinearOrder α] [TopologicalSpace β]
noncomputable def Function.leftLim (f : α → β) (a : α) : β := by
classical
haveI : Nonempty β := ⟨f a⟩
letI : TopologicalSpace α := Preorder.topology α
exact if 𝓝[<] a = ⊥ ∨ ¬∃ y, Tendsto f (𝓝[<] a) (𝓝 y) then f a else limUnder (𝓝[<] a) f
#align function.left_lim Function.leftLim
noncomputable def Function.rightLim (f : α → β) (a : α) : β :=
@Function.leftLim αᵒᵈ β _ _ f a
#align function.right_lim Function.rightLim
open Function
| Mathlib/Topology/Order/LeftRightLim.lean | 65 | 72 | theorem leftLim_eq_of_tendsto [hα : TopologicalSpace α] [h'α : OrderTopology α] [T2Space β]
{f : α → β} {a : α} {y : β} (h : 𝓝[<] a ≠ ⊥) (h' : Tendsto f (𝓝[<] a) (𝓝 y)) :
leftLim f a = y := by |
have h'' : ∃ y, Tendsto f (𝓝[<] a) (𝓝 y) := ⟨y, h'⟩
rw [h'α.topology_eq_generate_intervals] at h h' h''
simp only [leftLim, h, h'', not_true, or_self_iff, if_false]
haveI := neBot_iff.2 h
exact lim_eq h'
|
import Mathlib.Algebra.Algebra.Equiv
import Mathlib.LinearAlgebra.Dimension.StrongRankCondition
import Mathlib.LinearAlgebra.FreeModule.Basic
import Mathlib.LinearAlgebra.FreeModule.Finite.Basic
import Mathlib.SetTheory.Cardinal.Ordinal
#align_import algebra.quaternion from "leanprover-community/mathlib"@"cf7a7252c1989efe5800e0b3cdfeb4228ac6b40e"
@[ext]
structure QuaternionAlgebra (R : Type*) (a b : R) where
re : R
imI : R
imJ : R
imK : R
#align quaternion_algebra QuaternionAlgebra
#align quaternion_algebra.re QuaternionAlgebra.re
#align quaternion_algebra.im_i QuaternionAlgebra.imI
#align quaternion_algebra.im_j QuaternionAlgebra.imJ
#align quaternion_algebra.im_k QuaternionAlgebra.imK
@[inherit_doc]
scoped[Quaternion] notation "ℍ[" R "," a "," b "]" => QuaternionAlgebra R a b
open Quaternion
namespace QuaternionAlgebra
@[simps]
def equivProd {R : Type*} (c₁ c₂ : R) : ℍ[R,c₁,c₂] ≃ R × R × R × R where
toFun a := ⟨a.1, a.2, a.3, a.4⟩
invFun a := ⟨a.1, a.2.1, a.2.2.1, a.2.2.2⟩
left_inv _ := rfl
right_inv _ := rfl
#align quaternion_algebra.equiv_prod QuaternionAlgebra.equivProd
@[simps symm_apply]
def equivTuple {R : Type*} (c₁ c₂ : R) : ℍ[R,c₁,c₂] ≃ (Fin 4 → R) where
toFun a := ![a.1, a.2, a.3, a.4]
invFun a := ⟨a 0, a 1, a 2, a 3⟩
left_inv _ := rfl
right_inv f := by ext ⟨_, _ | _ | _ | _ | _ | ⟨⟩⟩ <;> rfl
#align quaternion_algebra.equiv_tuple QuaternionAlgebra.equivTuple
@[simp]
theorem equivTuple_apply {R : Type*} (c₁ c₂ : R) (x : ℍ[R,c₁,c₂]) :
equivTuple c₁ c₂ x = ![x.re, x.imI, x.imJ, x.imK] :=
rfl
#align quaternion_algebra.equiv_tuple_apply QuaternionAlgebra.equivTuple_apply
@[simp]
theorem mk.eta {R : Type*} {c₁ c₂} (a : ℍ[R,c₁,c₂]) : mk a.1 a.2 a.3 a.4 = a := rfl
#align quaternion_algebra.mk.eta QuaternionAlgebra.mk.eta
variable {S T R : Type*} [CommRing R] {c₁ c₂ : R} (r x y z : R) (a b c : ℍ[R,c₁,c₂])
instance [Subsingleton R] : Subsingleton ℍ[R, c₁, c₂] := (equivTuple c₁ c₂).subsingleton
instance [Nontrivial R] : Nontrivial ℍ[R, c₁, c₂] := (equivTuple c₁ c₂).surjective.nontrivial
def im (x : ℍ[R,c₁,c₂]) : ℍ[R,c₁,c₂] :=
⟨0, x.imI, x.imJ, x.imK⟩
#align quaternion_algebra.im QuaternionAlgebra.im
@[simp]
theorem im_re : a.im.re = 0 :=
rfl
#align quaternion_algebra.im_re QuaternionAlgebra.im_re
@[simp]
theorem im_imI : a.im.imI = a.imI :=
rfl
#align quaternion_algebra.im_im_i QuaternionAlgebra.im_imI
@[simp]
theorem im_imJ : a.im.imJ = a.imJ :=
rfl
#align quaternion_algebra.im_im_j QuaternionAlgebra.im_imJ
@[simp]
theorem im_imK : a.im.imK = a.imK :=
rfl
#align quaternion_algebra.im_im_k QuaternionAlgebra.im_imK
@[simp]
theorem im_idem : a.im.im = a.im :=
rfl
#align quaternion_algebra.im_idem QuaternionAlgebra.im_idem
@[coe] def coe (x : R) : ℍ[R,c₁,c₂] := ⟨x, 0, 0, 0⟩
instance : CoeTC R ℍ[R,c₁,c₂] := ⟨coe⟩
@[simp, norm_cast]
theorem coe_re : (x : ℍ[R,c₁,c₂]).re = x := rfl
#align quaternion_algebra.coe_re QuaternionAlgebra.coe_re
@[simp, norm_cast]
theorem coe_imI : (x : ℍ[R,c₁,c₂]).imI = 0 := rfl
#align quaternion_algebra.coe_im_i QuaternionAlgebra.coe_imI
@[simp, norm_cast]
theorem coe_imJ : (x : ℍ[R,c₁,c₂]).imJ = 0 := rfl
#align quaternion_algebra.coe_im_j QuaternionAlgebra.coe_imJ
@[simp, norm_cast]
theorem coe_imK : (x : ℍ[R,c₁,c₂]).imK = 0 := rfl
#align quaternion_algebra.coe_im_k QuaternionAlgebra.coe_imK
theorem coe_injective : Function.Injective (coe : R → ℍ[R,c₁,c₂]) := fun _ _ h => congr_arg re h
#align quaternion_algebra.coe_injective QuaternionAlgebra.coe_injective
@[simp]
theorem coe_inj {x y : R} : (x : ℍ[R,c₁,c₂]) = y ↔ x = y :=
coe_injective.eq_iff
#align quaternion_algebra.coe_inj QuaternionAlgebra.coe_inj
-- Porting note: removed `simps`, added simp lemmas manually
instance : Zero ℍ[R,c₁,c₂] := ⟨⟨0, 0, 0, 0⟩⟩
@[simp] theorem zero_re : (0 : ℍ[R,c₁,c₂]).re = 0 := rfl
#align quaternion_algebra.has_zero_zero_re QuaternionAlgebra.zero_re
@[simp] theorem zero_imI : (0 : ℍ[R,c₁,c₂]).imI = 0 := rfl
#align quaternion_algebra.has_zero_zero_im_i QuaternionAlgebra.zero_imI
@[simp] theorem zero_imJ : (0 : ℍ[R,c₁,c₂]).imJ = 0 := rfl
#align quaternion_algebra.zero_zero_im_j QuaternionAlgebra.zero_imJ
@[simp] theorem zero_imK : (0 : ℍ[R,c₁,c₂]).imK = 0 := rfl
#align quaternion_algebra.zero_zero_im_k QuaternionAlgebra.zero_imK
@[simp] theorem zero_im : (0 : ℍ[R,c₁,c₂]).im = 0 := rfl
@[simp, norm_cast]
theorem coe_zero : ((0 : R) : ℍ[R,c₁,c₂]) = 0 := rfl
#align quaternion_algebra.coe_zero QuaternionAlgebra.coe_zero
instance : Inhabited ℍ[R,c₁,c₂] := ⟨0⟩
-- Porting note: removed `simps`, added simp lemmas manually
instance : One ℍ[R,c₁,c₂] := ⟨⟨1, 0, 0, 0⟩⟩
@[simp] theorem one_re : (1 : ℍ[R,c₁,c₂]).re = 1 := rfl
#align quaternion_algebra.has_one_one_re QuaternionAlgebra.one_re
@[simp] theorem one_imI : (1 : ℍ[R,c₁,c₂]).imI = 0 := rfl
#align quaternion_algebra.has_one_one_im_i QuaternionAlgebra.one_imI
@[simp] theorem one_imJ : (1 : ℍ[R,c₁,c₂]).imJ = 0 := rfl
#align quaternion_algebra.one_one_im_j QuaternionAlgebra.one_imJ
@[simp] theorem one_imK : (1 : ℍ[R,c₁,c₂]).imK = 0 := rfl
#align quaternion_algebra.one_one_im_k QuaternionAlgebra.one_imK
@[simp] theorem one_im : (1 : ℍ[R,c₁,c₂]).im = 0 := rfl
@[simp, norm_cast]
theorem coe_one : ((1 : R) : ℍ[R,c₁,c₂]) = 1 := rfl
#align quaternion_algebra.coe_one QuaternionAlgebra.coe_one
-- Porting note: removed `simps`, added simp lemmas manually
instance : Add ℍ[R,c₁,c₂] :=
⟨fun a b => ⟨a.1 + b.1, a.2 + b.2, a.3 + b.3, a.4 + b.4⟩⟩
@[simp] theorem add_re : (a + b).re = a.re + b.re := rfl
#align quaternion_algebra.has_add_add_re QuaternionAlgebra.add_re
@[simp] theorem add_imI : (a + b).imI = a.imI + b.imI := rfl
#align quaternion_algebra.has_add_add_im_i QuaternionAlgebra.add_imI
@[simp] theorem add_imJ : (a + b).imJ = a.imJ + b.imJ := rfl
#align quaternion_algebra.has_add_add_im_j QuaternionAlgebra.add_imJ
@[simp] theorem add_imK : (a + b).imK = a.imK + b.imK := rfl
#align quaternion_algebra.has_add_add_im_k QuaternionAlgebra.add_imK
@[simp] theorem add_im : (a + b).im = a.im + b.im :=
QuaternionAlgebra.ext _ _ (zero_add _).symm rfl rfl rfl
@[simp]
theorem mk_add_mk (a₁ a₂ a₃ a₄ b₁ b₂ b₃ b₄ : R) :
(mk a₁ a₂ a₃ a₄ : ℍ[R,c₁,c₂]) + mk b₁ b₂ b₃ b₄ = mk (a₁ + b₁) (a₂ + b₂) (a₃ + b₃) (a₄ + b₄) :=
rfl
#align quaternion_algebra.mk_add_mk QuaternionAlgebra.mk_add_mk
@[simp, norm_cast]
theorem coe_add : ((x + y : R) : ℍ[R,c₁,c₂]) = x + y := by ext <;> simp
#align quaternion_algebra.coe_add QuaternionAlgebra.coe_add
-- Porting note: removed `simps`, added simp lemmas manually
instance : Neg ℍ[R,c₁,c₂] := ⟨fun a => ⟨-a.1, -a.2, -a.3, -a.4⟩⟩
@[simp] theorem neg_re : (-a).re = -a.re := rfl
#align quaternion_algebra.has_neg_neg_re QuaternionAlgebra.neg_re
@[simp] theorem neg_imI : (-a).imI = -a.imI := rfl
#align quaternion_algebra.has_neg_neg_im_i QuaternionAlgebra.neg_imI
@[simp] theorem neg_imJ : (-a).imJ = -a.imJ := rfl
#align quaternion_algebra.has_neg_neg_im_j QuaternionAlgebra.neg_imJ
@[simp] theorem neg_imK : (-a).imK = -a.imK := rfl
#align quaternion_algebra.has_neg_neg_im_k QuaternionAlgebra.neg_imK
@[simp] theorem neg_im : (-a).im = -a.im :=
QuaternionAlgebra.ext _ _ neg_zero.symm rfl rfl rfl
@[simp]
theorem neg_mk (a₁ a₂ a₃ a₄ : R) : -(mk a₁ a₂ a₃ a₄ : ℍ[R,c₁,c₂]) = ⟨-a₁, -a₂, -a₃, -a₄⟩ :=
rfl
#align quaternion_algebra.neg_mk QuaternionAlgebra.neg_mk
@[simp, norm_cast]
theorem coe_neg : ((-x : R) : ℍ[R,c₁,c₂]) = -x := by ext <;> simp
#align quaternion_algebra.coe_neg QuaternionAlgebra.coe_neg
instance : Sub ℍ[R,c₁,c₂] :=
⟨fun a b => ⟨a.1 - b.1, a.2 - b.2, a.3 - b.3, a.4 - b.4⟩⟩
@[simp] theorem sub_re : (a - b).re = a.re - b.re := rfl
#align quaternion_algebra.has_sub_sub_re QuaternionAlgebra.sub_re
@[simp] theorem sub_imI : (a - b).imI = a.imI - b.imI := rfl
#align quaternion_algebra.has_sub_sub_im_i QuaternionAlgebra.sub_imI
@[simp] theorem sub_imJ : (a - b).imJ = a.imJ - b.imJ := rfl
#align quaternion_algebra.has_sub_sub_im_j QuaternionAlgebra.sub_imJ
@[simp] theorem sub_imK : (a - b).imK = a.imK - b.imK := rfl
#align quaternion_algebra.has_sub_sub_im_k QuaternionAlgebra.sub_imK
@[simp] theorem sub_im : (a - b).im = a.im - b.im :=
QuaternionAlgebra.ext _ _ (sub_zero _).symm rfl rfl rfl
@[simp]
theorem mk_sub_mk (a₁ a₂ a₃ a₄ b₁ b₂ b₃ b₄ : R) :
(mk a₁ a₂ a₃ a₄ : ℍ[R,c₁,c₂]) - mk b₁ b₂ b₃ b₄ = mk (a₁ - b₁) (a₂ - b₂) (a₃ - b₃) (a₄ - b₄) :=
rfl
#align quaternion_algebra.mk_sub_mk QuaternionAlgebra.mk_sub_mk
@[simp, norm_cast]
theorem coe_im : (x : ℍ[R,c₁,c₂]).im = 0 :=
rfl
#align quaternion_algebra.coe_im QuaternionAlgebra.coe_im
@[simp]
theorem re_add_im : ↑a.re + a.im = a :=
QuaternionAlgebra.ext _ _ (add_zero _) (zero_add _) (zero_add _) (zero_add _)
#align quaternion_algebra.re_add_im QuaternionAlgebra.re_add_im
@[simp]
theorem sub_self_im : a - a.im = a.re :=
QuaternionAlgebra.ext _ _ (sub_zero _) (sub_self _) (sub_self _) (sub_self _)
#align quaternion_algebra.sub_self_im QuaternionAlgebra.sub_self_im
@[simp]
theorem sub_self_re : a - a.re = a.im :=
QuaternionAlgebra.ext _ _ (sub_self _) (sub_zero _) (sub_zero _) (sub_zero _)
#align quaternion_algebra.sub_self_re QuaternionAlgebra.sub_self_re
instance : Mul ℍ[R,c₁,c₂] :=
⟨fun a b =>
⟨a.1 * b.1 + c₁ * a.2 * b.2 + c₂ * a.3 * b.3 - c₁ * c₂ * a.4 * b.4,
a.1 * b.2 + a.2 * b.1 - c₂ * a.3 * b.4 + c₂ * a.4 * b.3,
a.1 * b.3 + c₁ * a.2 * b.4 + a.3 * b.1 - c₁ * a.4 * b.2,
a.1 * b.4 + a.2 * b.3 - a.3 * b.2 + a.4 * b.1⟩⟩
@[simp]
theorem mul_re : (a * b).re = a.1 * b.1 + c₁ * a.2 * b.2 + c₂ * a.3 * b.3 - c₁ * c₂ * a.4 * b.4 :=
rfl
#align quaternion_algebra.has_mul_mul_re QuaternionAlgebra.mul_re
@[simp]
theorem mul_imI : (a * b).imI = a.1 * b.2 + a.2 * b.1 - c₂ * a.3 * b.4 + c₂ * a.4 * b.3 := rfl
#align quaternion_algebra.has_mul_mul_im_i QuaternionAlgebra.mul_imI
@[simp]
theorem mul_imJ : (a * b).imJ = a.1 * b.3 + c₁ * a.2 * b.4 + a.3 * b.1 - c₁ * a.4 * b.2 := rfl
#align quaternion_algebra.has_mul_mul_im_j QuaternionAlgebra.mul_imJ
@[simp] theorem mul_imK : (a * b).imK = a.1 * b.4 + a.2 * b.3 - a.3 * b.2 + a.4 * b.1 := rfl
#align quaternion_algebra.has_mul_mul_im_k QuaternionAlgebra.mul_imK
@[simp]
theorem mk_mul_mk (a₁ a₂ a₃ a₄ b₁ b₂ b₃ b₄ : R) :
(mk a₁ a₂ a₃ a₄ : ℍ[R,c₁,c₂]) * mk b₁ b₂ b₃ b₄ =
⟨a₁ * b₁ + c₁ * a₂ * b₂ + c₂ * a₃ * b₃ - c₁ * c₂ * a₄ * b₄,
a₁ * b₂ + a₂ * b₁ - c₂ * a₃ * b₄ + c₂ * a₄ * b₃,
a₁ * b₃ + c₁ * a₂ * b₄ + a₃ * b₁ - c₁ * a₄ * b₂, a₁ * b₄ + a₂ * b₃ - a₃ * b₂ + a₄ * b₁⟩ :=
rfl
#align quaternion_algebra.mk_mul_mk QuaternionAlgebra.mk_mul_mk
section
variable [SMul S R] [SMul T R] (s : S)
-- Porting note: Lean 4 auto drops the unused `[Ring R]` argument
instance : SMul S ℍ[R,c₁,c₂] where smul s a := ⟨s • a.1, s • a.2, s • a.3, s • a.4⟩
instance [SMul S T] [IsScalarTower S T R] : IsScalarTower S T ℍ[R,c₁,c₂] where
smul_assoc s t x := by ext <;> exact smul_assoc _ _ _
instance [SMulCommClass S T R] : SMulCommClass S T ℍ[R,c₁,c₂] where
smul_comm s t x := by ext <;> exact smul_comm _ _ _
@[simp] theorem smul_re : (s • a).re = s • a.re := rfl
#align quaternion_algebra.smul_re QuaternionAlgebra.smul_re
@[simp] theorem smul_imI : (s • a).imI = s • a.imI := rfl
#align quaternion_algebra.smul_im_i QuaternionAlgebra.smul_imI
@[simp] theorem smul_imJ : (s • a).imJ = s • a.imJ := rfl
#align quaternion_algebra.smul_im_j QuaternionAlgebra.smul_imJ
@[simp] theorem smul_imK : (s • a).imK = s • a.imK := rfl
#align quaternion_algebra.smul_im_k QuaternionAlgebra.smul_imK
@[simp] theorem smul_im {S} [SMulZeroClass S R] (s : S) : (s • a).im = s • a.im :=
QuaternionAlgebra.ext _ _ (smul_zero s).symm rfl rfl rfl
@[simp]
theorem smul_mk (re im_i im_j im_k : R) :
s • (⟨re, im_i, im_j, im_k⟩ : ℍ[R,c₁,c₂]) = ⟨s • re, s • im_i, s • im_j, s • im_k⟩ :=
rfl
#align quaternion_algebra.smul_mk QuaternionAlgebra.smul_mk
end
@[simp, norm_cast]
theorem coe_smul [SMulZeroClass S R] (s : S) (r : R) :
(↑(s • r) : ℍ[R,c₁,c₂]) = s • (r : ℍ[R,c₁,c₂]) :=
QuaternionAlgebra.ext _ _ rfl (smul_zero s).symm (smul_zero s).symm (smul_zero s).symm
#align quaternion_algebra.coe_smul QuaternionAlgebra.coe_smul
instance : AddCommGroup ℍ[R,c₁,c₂] :=
(equivProd c₁ c₂).injective.addCommGroup _ rfl (fun _ _ ↦ rfl) (fun _ ↦ rfl) (fun _ _ ↦ rfl)
(fun _ _ ↦ rfl) (fun _ _ ↦ rfl)
instance : AddCommGroupWithOne ℍ[R,c₁,c₂] where
natCast n := ((n : R) : ℍ[R,c₁,c₂])
natCast_zero := by simp
natCast_succ := by simp
intCast n := ((n : R) : ℍ[R,c₁,c₂])
intCast_ofNat _ := congr_arg coe (Int.cast_natCast _)
intCast_negSucc n := by
change coe _ = -coe _
rw [Int.cast_negSucc, coe_neg]
@[simp, norm_cast]
theorem natCast_re (n : ℕ) : (n : ℍ[R,c₁,c₂]).re = n :=
rfl
#align quaternion_algebra.nat_cast_re QuaternionAlgebra.natCast_re
@[deprecated (since := "2024-04-17")]
alias nat_cast_re := natCast_re
@[simp, norm_cast]
theorem natCast_imI (n : ℕ) : (n : ℍ[R,c₁,c₂]).imI = 0 :=
rfl
#align quaternion_algebra.nat_cast_im_i QuaternionAlgebra.natCast_imI
@[deprecated (since := "2024-04-17")]
alias nat_cast_imI := natCast_imI
@[simp, norm_cast]
theorem natCast_imJ (n : ℕ) : (n : ℍ[R,c₁,c₂]).imJ = 0 :=
rfl
#align quaternion_algebra.nat_cast_im_j QuaternionAlgebra.natCast_imJ
@[deprecated (since := "2024-04-17")]
alias nat_cast_imJ := natCast_imJ
@[simp, norm_cast]
theorem natCast_imK (n : ℕ) : (n : ℍ[R,c₁,c₂]).imK = 0 :=
rfl
#align quaternion_algebra.nat_cast_im_k QuaternionAlgebra.natCast_imK
@[deprecated (since := "2024-04-17")]
alias nat_cast_imK := natCast_imK
@[simp, norm_cast]
theorem natCast_im (n : ℕ) : (n : ℍ[R,c₁,c₂]).im = 0 :=
rfl
#align quaternion_algebra.nat_cast_im QuaternionAlgebra.natCast_im
@[deprecated (since := "2024-04-17")]
alias nat_cast_im := natCast_im
@[norm_cast]
theorem coe_natCast (n : ℕ) : ↑(n : R) = (n : ℍ[R,c₁,c₂]) :=
rfl
#align quaternion_algebra.coe_nat_cast QuaternionAlgebra.coe_natCast
@[deprecated (since := "2024-04-17")]
alias coe_nat_cast := coe_natCast
@[simp, norm_cast]
theorem intCast_re (z : ℤ) : (z : ℍ[R,c₁,c₂]).re = z :=
rfl
#align quaternion_algebra.int_cast_re QuaternionAlgebra.intCast_re
@[deprecated (since := "2024-04-17")]
alias int_cast_re := intCast_re
@[simp, norm_cast]
theorem intCast_imI (z : ℤ) : (z : ℍ[R,c₁,c₂]).imI = 0 :=
rfl
#align quaternion_algebra.int_cast_im_i QuaternionAlgebra.intCast_imI
@[deprecated (since := "2024-04-17")]
alias int_cast_imI := intCast_imI
@[simp, norm_cast]
theorem intCast_imJ (z : ℤ) : (z : ℍ[R,c₁,c₂]).imJ = 0 :=
rfl
#align quaternion_algebra.int_cast_im_j QuaternionAlgebra.intCast_imJ
@[deprecated (since := "2024-04-17")]
alias int_cast_imJ := intCast_imJ
@[simp, norm_cast]
theorem intCast_imK (z : ℤ) : (z : ℍ[R,c₁,c₂]).imK = 0 :=
rfl
#align quaternion_algebra.int_cast_im_k QuaternionAlgebra.intCast_imK
@[deprecated (since := "2024-04-17")]
alias int_cast_imK := intCast_imK
@[simp, norm_cast]
theorem intCast_im (z : ℤ) : (z : ℍ[R,c₁,c₂]).im = 0 :=
rfl
#align quaternion_algebra.int_cast_im QuaternionAlgebra.intCast_im
@[deprecated (since := "2024-04-17")]
alias int_cast_im := intCast_im
@[norm_cast]
theorem coe_intCast (z : ℤ) : ↑(z : R) = (z : ℍ[R,c₁,c₂]) :=
rfl
#align quaternion_algebra.coe_int_cast QuaternionAlgebra.coe_intCast
@[deprecated (since := "2024-04-17")]
alias coe_int_cast := coe_intCast
instance instRing : Ring ℍ[R,c₁,c₂] where
__ := inferInstanceAs (AddCommGroupWithOne ℍ[R,c₁,c₂])
left_distrib _ _ _ := by ext <;> simp <;> ring
right_distrib _ _ _ := by ext <;> simp <;> ring
zero_mul _ := by ext <;> simp
mul_zero _ := by ext <;> simp
mul_assoc _ _ _ := by ext <;> simp <;> ring
one_mul _ := by ext <;> simp
mul_one _ := by ext <;> simp
@[norm_cast, simp]
theorem coe_mul : ((x * y : R) : ℍ[R,c₁,c₂]) = x * y := by ext <;> simp
#align quaternion_algebra.coe_mul QuaternionAlgebra.coe_mul
-- TODO: add weaker `MulAction`, `DistribMulAction`, and `Module` instances (and repeat them
-- for `ℍ[R]`)
instance [CommSemiring S] [Algebra S R] : Algebra S ℍ[R,c₁,c₂] where
smul := (· • ·)
toFun s := coe (algebraMap S R s)
map_one' := by simp only [map_one, coe_one]
map_zero' := by simp only [map_zero, coe_zero]
map_mul' x y := by simp only [map_mul, coe_mul]
map_add' x y := by simp only [map_add, coe_add]
smul_def' s x := by ext <;> simp [Algebra.smul_def]
commutes' s x := by ext <;> simp [Algebra.commutes]
theorem algebraMap_eq (r : R) : algebraMap R ℍ[R,c₁,c₂] r = ⟨r, 0, 0, 0⟩ :=
rfl
#align quaternion_algebra.algebra_map_eq QuaternionAlgebra.algebraMap_eq
theorem algebraMap_injective : (algebraMap R ℍ[R,c₁,c₂] : _ → _).Injective :=
fun _ _ ↦ by simp [algebraMap_eq]
instance [NoZeroDivisors R] : NoZeroSMulDivisors R ℍ[R,c₁,c₂] := ⟨by
rintro t ⟨a, b, c, d⟩ h
rw [or_iff_not_imp_left]
intro ht
simpa [QuaternionAlgebra.ext_iff, ht] using h⟩
section
variable (c₁ c₂)
@[simps]
def reₗ : ℍ[R,c₁,c₂] →ₗ[R] R where
toFun := re
map_add' _ _ := rfl
map_smul' _ _ := rfl
#align quaternion_algebra.re_lm QuaternionAlgebra.reₗ
@[simps]
def imIₗ : ℍ[R,c₁,c₂] →ₗ[R] R where
toFun := imI
map_add' _ _ := rfl
map_smul' _ _ := rfl
#align quaternion_algebra.im_i_lm QuaternionAlgebra.imIₗ
@[simps]
def imJₗ : ℍ[R,c₁,c₂] →ₗ[R] R where
toFun := imJ
map_add' _ _ := rfl
map_smul' _ _ := rfl
#align quaternion_algebra.im_j_lm QuaternionAlgebra.imJₗ
@[simps]
def imKₗ : ℍ[R,c₁,c₂] →ₗ[R] R where
toFun := imK
map_add' _ _ := rfl
map_smul' _ _ := rfl
#align quaternion_algebra.im_k_lm QuaternionAlgebra.imKₗ
def linearEquivTuple : ℍ[R,c₁,c₂] ≃ₗ[R] Fin 4 → R :=
LinearEquiv.symm -- proofs are not `rfl` in the forward direction
{ (equivTuple c₁ c₂).symm with
toFun := (equivTuple c₁ c₂).symm
invFun := equivTuple c₁ c₂
map_add' := fun _ _ => rfl
map_smul' := fun _ _ => rfl }
#align quaternion_algebra.linear_equiv_tuple QuaternionAlgebra.linearEquivTuple
@[simp]
theorem coe_linearEquivTuple : ⇑(linearEquivTuple c₁ c₂) = equivTuple c₁ c₂ :=
rfl
#align quaternion_algebra.coe_linear_equiv_tuple QuaternionAlgebra.coe_linearEquivTuple
@[simp]
theorem coe_linearEquivTuple_symm : ⇑(linearEquivTuple c₁ c₂).symm = (equivTuple c₁ c₂).symm :=
rfl
#align quaternion_algebra.coe_linear_equiv_tuple_symm QuaternionAlgebra.coe_linearEquivTuple_symm
noncomputable def basisOneIJK : Basis (Fin 4) R ℍ[R,c₁,c₂] :=
.ofEquivFun <| linearEquivTuple c₁ c₂
#align quaternion_algebra.basis_one_i_j_k QuaternionAlgebra.basisOneIJK
@[simp]
theorem coe_basisOneIJK_repr (q : ℍ[R,c₁,c₂]) :
⇑((basisOneIJK c₁ c₂).repr q) = ![q.re, q.imI, q.imJ, q.imK] :=
rfl
#align quaternion_algebra.coe_basis_one_i_j_k_repr QuaternionAlgebra.coe_basisOneIJK_repr
instance : Module.Finite R ℍ[R,c₁,c₂] := .of_basis (basisOneIJK c₁ c₂)
instance : Module.Free R ℍ[R,c₁,c₂] := .of_basis (basisOneIJK c₁ c₂)
theorem rank_eq_four [StrongRankCondition R] : Module.rank R ℍ[R,c₁,c₂] = 4 := by
rw [rank_eq_card_basis (basisOneIJK c₁ c₂), Fintype.card_fin]
norm_num
#align quaternion_algebra.rank_eq_four QuaternionAlgebra.rank_eq_four
theorem finrank_eq_four [StrongRankCondition R] : FiniteDimensional.finrank R ℍ[R,c₁,c₂] = 4 := by
rw [FiniteDimensional.finrank, rank_eq_four, Cardinal.toNat_ofNat]
#align quaternion_algebra.finrank_eq_four QuaternionAlgebra.finrank_eq_four
@[simps]
def swapEquiv : ℍ[R,c₁,c₂] ≃ₐ[R] ℍ[R, c₂, c₁] where
toFun t := ⟨t.1, t.3, t.2, -t.4⟩
invFun t := ⟨t.1, t.3, t.2, -t.4⟩
left_inv _ := by simp
right_inv _ := by simp
map_mul' _ _ := by
ext
<;> simp only [mul_re, mul_imJ, mul_imI, add_left_inj, mul_imK, neg_mul, neg_add_rev,
neg_sub, mk_mul_mk, mul_neg, neg_neg, sub_neg_eq_add]
<;> ring
map_add' _ _ := by ext <;> simp [add_comm]
commutes' _ := by simp [algebraMap_eq]
end
@[norm_cast, simp]
theorem coe_sub : ((x - y : R) : ℍ[R,c₁,c₂]) = x - y :=
(algebraMap R ℍ[R,c₁,c₂]).map_sub x y
#align quaternion_algebra.coe_sub QuaternionAlgebra.coe_sub
@[norm_cast, simp]
theorem coe_pow (n : ℕ) : (↑(x ^ n) : ℍ[R,c₁,c₂]) = (x : ℍ[R,c₁,c₂]) ^ n :=
(algebraMap R ℍ[R,c₁,c₂]).map_pow x n
#align quaternion_algebra.coe_pow QuaternionAlgebra.coe_pow
theorem coe_commutes : ↑r * a = a * r :=
Algebra.commutes r a
#align quaternion_algebra.coe_commutes QuaternionAlgebra.coe_commutes
theorem coe_commute : Commute (↑r) a :=
coe_commutes r a
#align quaternion_algebra.coe_commute QuaternionAlgebra.coe_commute
theorem coe_mul_eq_smul : ↑r * a = r • a :=
(Algebra.smul_def r a).symm
#align quaternion_algebra.coe_mul_eq_smul QuaternionAlgebra.coe_mul_eq_smul
theorem mul_coe_eq_smul : a * r = r • a := by rw [← coe_commutes, coe_mul_eq_smul]
#align quaternion_algebra.mul_coe_eq_smul QuaternionAlgebra.mul_coe_eq_smul
@[norm_cast, simp]
theorem coe_algebraMap : ⇑(algebraMap R ℍ[R,c₁,c₂]) = coe :=
rfl
#align quaternion_algebra.coe_algebra_map QuaternionAlgebra.coe_algebraMap
theorem smul_coe : x • (y : ℍ[R,c₁,c₂]) = ↑(x * y) := by rw [coe_mul, coe_mul_eq_smul]
#align quaternion_algebra.smul_coe QuaternionAlgebra.smul_coe
instance instStarQuaternionAlgebra : Star ℍ[R,c₁,c₂] where star a := ⟨a.1, -a.2, -a.3, -a.4⟩
@[simp] theorem re_star : (star a).re = a.re := rfl
#align quaternion_algebra.re_star QuaternionAlgebra.re_star
@[simp]
theorem imI_star : (star a).imI = -a.imI :=
rfl
#align quaternion_algebra.im_i_star QuaternionAlgebra.imI_star
@[simp]
theorem imJ_star : (star a).imJ = -a.imJ :=
rfl
#align quaternion_algebra.im_j_star QuaternionAlgebra.imJ_star
@[simp]
theorem imK_star : (star a).imK = -a.imK :=
rfl
#align quaternion_algebra.im_k_star QuaternionAlgebra.imK_star
@[simp]
theorem im_star : (star a).im = -a.im :=
QuaternionAlgebra.ext _ _ neg_zero.symm rfl rfl rfl
#align quaternion_algebra.im_star QuaternionAlgebra.im_star
@[simp]
theorem star_mk (a₁ a₂ a₃ a₄ : R) : star (mk a₁ a₂ a₃ a₄ : ℍ[R,c₁,c₂]) = ⟨a₁, -a₂, -a₃, -a₄⟩ :=
rfl
#align quaternion_algebra.star_mk QuaternionAlgebra.star_mk
instance instStarRing : StarRing ℍ[R,c₁,c₂] where
star_involutive x := by simp [Star.star]
star_add a b := by ext <;> simp [add_comm]
star_mul a b := by ext <;> simp <;> ring
theorem self_add_star' : a + star a = ↑(2 * a.re) := by ext <;> simp [two_mul]
#align quaternion_algebra.self_add_star' QuaternionAlgebra.self_add_star'
theorem self_add_star : a + star a = 2 * a.re := by simp only [self_add_star', two_mul, coe_add]
#align quaternion_algebra.self_add_star QuaternionAlgebra.self_add_star
theorem star_add_self' : star a + a = ↑(2 * a.re) := by rw [add_comm, self_add_star']
#align quaternion_algebra.star_add_self' QuaternionAlgebra.star_add_self'
theorem star_add_self : star a + a = 2 * a.re := by rw [add_comm, self_add_star]
#align quaternion_algebra.star_add_self QuaternionAlgebra.star_add_self
theorem star_eq_two_re_sub : star a = ↑(2 * a.re) - a :=
eq_sub_iff_add_eq.2 a.star_add_self'
#align quaternion_algebra.star_eq_two_re_sub QuaternionAlgebra.star_eq_two_re_sub
instance : IsStarNormal a :=
⟨by
rw [a.star_eq_two_re_sub]
exact (coe_commute (2 * a.re) a).sub_left (Commute.refl a)⟩
@[simp, norm_cast]
theorem star_coe : star (x : ℍ[R,c₁,c₂]) = x := by ext <;> simp
#align quaternion_algebra.star_coe QuaternionAlgebra.star_coe
@[simp] theorem star_im : star a.im = -a.im := im_star _
#align quaternion_algebra.star_im QuaternionAlgebra.star_im
@[simp]
theorem star_smul [Monoid S] [DistribMulAction S R] (s : S) (a : ℍ[R,c₁,c₂]) :
star (s • a) = s • star a :=
QuaternionAlgebra.ext _ _ rfl (smul_neg _ _).symm (smul_neg _ _).symm (smul_neg _ _).symm
#align quaternion_algebra.star_smul QuaternionAlgebra.star_smul
theorem eq_re_of_eq_coe {a : ℍ[R,c₁,c₂]} {x : R} (h : a = x) : a = a.re := by rw [h, coe_re]
#align quaternion_algebra.eq_re_of_eq_coe QuaternionAlgebra.eq_re_of_eq_coe
theorem eq_re_iff_mem_range_coe {a : ℍ[R,c₁,c₂]} :
a = a.re ↔ a ∈ Set.range (coe : R → ℍ[R,c₁,c₂]) :=
⟨fun h => ⟨a.re, h.symm⟩, fun ⟨_, h⟩ => eq_re_of_eq_coe h.symm⟩
#align quaternion_algebra.eq_re_iff_mem_range_coe QuaternionAlgebra.eq_re_iff_mem_range_coe
section CharZero
variable [NoZeroDivisors R] [CharZero R]
@[simp]
theorem star_eq_self {c₁ c₂ : R} {a : ℍ[R,c₁,c₂]} : star a = a ↔ a = a.re := by
simp [QuaternionAlgebra.ext_iff, neg_eq_iff_add_eq_zero, add_self_eq_zero]
#align quaternion_algebra.star_eq_self QuaternionAlgebra.star_eq_self
| Mathlib/Algebra/Quaternion.lean | 760 | 761 | theorem star_eq_neg {c₁ c₂ : R} {a : ℍ[R,c₁,c₂]} : star a = -a ↔ a.re = 0 := by |
simp [QuaternionAlgebra.ext_iff, eq_neg_iff_add_eq_zero]
|
import Mathlib.Algebra.BigOperators.Fin
import Mathlib.Algebra.BigOperators.NatAntidiagonal
import Mathlib.Algebra.CharZero.Lemmas
import Mathlib.Data.Finset.NatAntidiagonal
import Mathlib.Data.Nat.Choose.Central
import Mathlib.Data.Tree.Basic
import Mathlib.Tactic.FieldSimp
import Mathlib.Tactic.GCongr
import Mathlib.Tactic.Positivity
#align_import combinatorics.catalan from "leanprover-community/mathlib"@"26b40791e4a5772a4e53d0e28e4df092119dc7da"
open Finset
open Finset.antidiagonal (fst_le snd_le)
def catalan : ℕ → ℕ
| 0 => 1
| n + 1 =>
∑ i : Fin n.succ,
catalan i * catalan (n - i)
#align catalan catalan
@[simp]
theorem catalan_zero : catalan 0 = 1 := by rw [catalan]
#align catalan_zero catalan_zero
theorem catalan_succ (n : ℕ) : catalan (n + 1) = ∑ i : Fin n.succ, catalan i * catalan (n - i) := by
rw [catalan]
#align catalan_succ catalan_succ
theorem catalan_succ' (n : ℕ) :
catalan (n + 1) = ∑ ij ∈ antidiagonal n, catalan ij.1 * catalan ij.2 := by
rw [catalan_succ, Nat.sum_antidiagonal_eq_sum_range_succ (fun x y => catalan x * catalan y) n,
sum_range]
#align catalan_succ' catalan_succ'
@[simp]
theorem catalan_one : catalan 1 = 1 := by simp [catalan_succ]
#align catalan_one catalan_one
private def gosperCatalan (n j : ℕ) : ℚ :=
Nat.centralBinom j * Nat.centralBinom (n - j) * (2 * j - n) / (2 * n * (n + 1))
private theorem gosper_trick {n i : ℕ} (h : i ≤ n) :
gosperCatalan (n + 1) (i + 1) - gosperCatalan (n + 1) i =
Nat.centralBinom i / (i + 1) * Nat.centralBinom (n - i) / (n - i + 1) := by
have l₁ : (i : ℚ) + 1 ≠ 0 := by norm_cast
have l₂ : (n : ℚ) - i + 1 ≠ 0 := by norm_cast
have h₁ := (mul_div_cancel_left₀ (↑(Nat.centralBinom (i + 1))) l₁).symm
have h₂ := (mul_div_cancel_left₀ (↑(Nat.centralBinom (n - i + 1))) l₂).symm
have h₃ : ((i : ℚ) + 1) * (i + 1).centralBinom = 2 * (2 * i + 1) * i.centralBinom :=
mod_cast Nat.succ_mul_centralBinom_succ i
have h₄ :
((n : ℚ) - i + 1) * (n - i + 1).centralBinom = 2 * (2 * (n - i) + 1) * (n - i).centralBinom :=
mod_cast Nat.succ_mul_centralBinom_succ (n - i)
simp only [gosperCatalan]
push_cast
rw [show n + 1 - i = n - i + 1 by rw [Nat.add_comm (n - i) 1, ← (Nat.add_sub_assoc h 1),
add_comm]]
rw [h₁, h₂, h₃, h₄]
field_simp
ring
private theorem gosper_catalan_sub_eq_central_binom_div (n : ℕ) : gosperCatalan (n + 1) (n + 1) -
gosperCatalan (n + 1) 0 = Nat.centralBinom (n + 1) / (n + 2) := by
have : (n : ℚ) + 1 ≠ 0 := by norm_cast
have : (n : ℚ) + 1 + 1 ≠ 0 := by norm_cast
have h : (n : ℚ) + 2 ≠ 0 := by norm_cast
simp only [gosperCatalan, Nat.sub_zero, Nat.centralBinom_zero, Nat.sub_self]
field_simp
ring
theorem catalan_eq_centralBinom_div (n : ℕ) : catalan n = n.centralBinom / (n + 1) := by
suffices (catalan n : ℚ) = Nat.centralBinom n / (n + 1) by
have h := Nat.succ_dvd_centralBinom n
exact mod_cast this
induction' n using Nat.case_strong_induction_on with d hd
· simp
· simp_rw [catalan_succ, Nat.cast_sum, Nat.cast_mul]
trans (∑ i : Fin d.succ, Nat.centralBinom i / (i + 1) *
(Nat.centralBinom (d - i) / (d - i + 1)) : ℚ)
· congr
ext1 x
have m_le_d : x.val ≤ d := by apply Nat.le_of_lt_succ; apply x.2
have d_minus_x_le_d : (d - x.val) ≤ d := tsub_le_self
rw [hd _ m_le_d, hd _ d_minus_x_le_d]
norm_cast
· trans (∑ i : Fin d.succ, (gosperCatalan (d + 1) (i + 1) - gosperCatalan (d + 1) i))
· refine sum_congr rfl fun i _ => ?_
rw [gosper_trick i.is_le, mul_div]
· rw [← sum_range fun i => gosperCatalan (d + 1) (i + 1) - gosperCatalan (d + 1) i,
sum_range_sub, Nat.succ_eq_add_one]
rw [gosper_catalan_sub_eq_central_binom_div d]
norm_cast
#align catalan_eq_central_binom_div catalan_eq_centralBinom_div
theorem succ_mul_catalan_eq_centralBinom (n : ℕ) : (n + 1) * catalan n = n.centralBinom :=
(Nat.eq_mul_of_div_eq_right n.succ_dvd_centralBinom (catalan_eq_centralBinom_div n).symm).symm
#align succ_mul_catalan_eq_central_binom succ_mul_catalan_eq_centralBinom
theorem catalan_two : catalan 2 = 2 := by
norm_num [catalan_eq_centralBinom_div, Nat.centralBinom, Nat.choose]
#align catalan_two catalan_two
theorem catalan_three : catalan 3 = 5 := by
norm_num [catalan_eq_centralBinom_div, Nat.centralBinom, Nat.choose]
#align catalan_three catalan_three
namespace Tree
open Tree
abbrev pairwiseNode (a b : Finset (Tree Unit)) : Finset (Tree Unit) :=
(a ×ˢ b).map ⟨fun x => x.1 △ x.2, fun ⟨x₁, x₂⟩ ⟨y₁, y₂⟩ => fun h => by simpa using h⟩
#align tree.pairwise_node Tree.pairwiseNode
def treesOfNumNodesEq : ℕ → Finset (Tree Unit)
| 0 => {nil}
| n + 1 =>
(antidiagonal n).attach.biUnion fun ijh =>
-- Porting note: `unusedHavesSuffices` linter is not happy with this. Commented out.
-- have := Nat.lt_succ_of_le (fst_le ijh.2)
-- have := Nat.lt_succ_of_le (snd_le ijh.2)
pairwiseNode (treesOfNumNodesEq ijh.1.1) (treesOfNumNodesEq ijh.1.2)
-- Porting note: Add this to satisfy the linter.
decreasing_by
· simp_wf; have := fst_le ijh.2; omega
· simp_wf; have := snd_le ijh.2; omega
#align tree.trees_of_num_nodes_eq Tree.treesOfNumNodesEq
@[simp]
| Mathlib/Combinatorics/Enumerative/Catalan.lean | 178 | 178 | theorem treesOfNumNodesEq_zero : treesOfNumNodesEq 0 = {nil} := by | rw [treesOfNumNodesEq]
|
import Mathlib.Algebra.CharP.Invertible
import Mathlib.Algebra.Order.Module.OrderedSMul
import Mathlib.Data.Complex.Cardinality
import Mathlib.Data.Fin.VecNotation
import Mathlib.LinearAlgebra.FiniteDimensional
#align_import data.complex.module from "leanprover-community/mathlib"@"c7bce2818663f456335892ddbdd1809f111a5b72"
namespace Complex
open ComplexConjugate
open scoped SMul
variable {R : Type*} {S : Type*}
attribute [local ext] Complex.ext
-- Test that the `SMul ℚ ℂ` instance is correct.
example : (Complex.SMul.instSMulRealComplex : SMul ℚ ℂ) = (Algebra.toSMul : SMul ℚ ℂ) := rfl
-- priority manually adjusted in #11980
instance (priority := 90) [SMul R ℝ] [SMul S ℝ] [SMulCommClass R S ℝ] : SMulCommClass R S ℂ where
smul_comm r s x := by ext <;> simp [smul_re, smul_im, smul_comm]
-- priority manually adjusted in #11980
instance (priority := 90) [SMul R S] [SMul R ℝ] [SMul S ℝ] [IsScalarTower R S ℝ] :
IsScalarTower R S ℂ where
smul_assoc r s x := by ext <;> simp [smul_re, smul_im, smul_assoc]
-- priority manually adjusted in #11980
instance (priority := 90) [SMul R ℝ] [SMul Rᵐᵒᵖ ℝ] [IsCentralScalar R ℝ] :
IsCentralScalar R ℂ where
op_smul_eq_smul r x := by ext <;> simp [smul_re, smul_im, op_smul_eq_smul]
-- priority manually adjusted in #11980
instance (priority := 90) mulAction [Monoid R] [MulAction R ℝ] : MulAction R ℂ where
one_smul x := by ext <;> simp [smul_re, smul_im, one_smul]
mul_smul r s x := by ext <;> simp [smul_re, smul_im, mul_smul]
-- priority manually adjusted in #11980
instance (priority := 90) distribSMul [DistribSMul R ℝ] : DistribSMul R ℂ where
smul_add r x y := by ext <;> simp [smul_re, smul_im, smul_add]
smul_zero r := by ext <;> simp [smul_re, smul_im, smul_zero]
-- priority manually adjusted in #11980
instance (priority := 90) [Semiring R] [DistribMulAction R ℝ] : DistribMulAction R ℂ :=
{ Complex.distribSMul, Complex.mulAction with }
-- priority manually adjusted in #11980
instance (priority := 100) instModule [Semiring R] [Module R ℝ] : Module R ℂ where
add_smul r s x := by ext <;> simp [smul_re, smul_im, add_smul]
zero_smul r := by ext <;> simp [smul_re, smul_im, zero_smul]
-- priority manually adjusted in #11980
instance (priority := 95) instAlgebraOfReal [CommSemiring R] [Algebra R ℝ] : Algebra R ℂ :=
{ Complex.ofReal.comp (algebraMap R ℝ) with
smul := (· • ·)
smul_def' := fun r x => by ext <;> simp [smul_re, smul_im, Algebra.smul_def]
commutes' := fun r ⟨xr, xi⟩ => by ext <;> simp [smul_re, smul_im, Algebra.commutes] }
instance : StarModule ℝ ℂ :=
⟨fun r x => by simp only [star_def, star_trivial, real_smul, map_mul, conj_ofReal]⟩
@[simp]
theorem coe_algebraMap : (algebraMap ℝ ℂ : ℝ → ℂ) = ((↑) : ℝ → ℂ) :=
rfl
#align complex.coe_algebra_map Complex.coe_algebraMap
section
variable {A : Type*} [Semiring A] [Algebra ℝ A]
@[simp]
theorem _root_.AlgHom.map_coe_real_complex (f : ℂ →ₐ[ℝ] A) (x : ℝ) : f x = algebraMap ℝ A x :=
f.commutes x
#align alg_hom.map_coe_real_complex AlgHom.map_coe_real_complex
@[ext]
theorem algHom_ext ⦃f g : ℂ →ₐ[ℝ] A⦄ (h : f I = g I) : f = g := by
ext ⟨x, y⟩
simp only [mk_eq_add_mul_I, AlgHom.map_add, AlgHom.map_coe_real_complex, AlgHom.map_mul, h]
#align complex.alg_hom_ext Complex.algHom_ext
end
open Submodule FiniteDimensional
noncomputable def basisOneI : Basis (Fin 2) ℝ ℂ :=
Basis.ofEquivFun
{ toFun := fun z => ![z.re, z.im]
invFun := fun c => c 0 + c 1 • I
left_inv := fun z => by simp
right_inv := fun c => by
ext i
fin_cases i <;> simp
map_add' := fun z z' => by simp
map_smul' := fun c z => by simp }
set_option linter.uppercaseLean3 false in
#align complex.basis_one_I Complex.basisOneI
@[simp]
theorem coe_basisOneI_repr (z : ℂ) : ⇑(basisOneI.repr z) = ![z.re, z.im] :=
rfl
set_option linter.uppercaseLean3 false in
#align complex.coe_basis_one_I_repr Complex.coe_basisOneI_repr
@[simp]
theorem coe_basisOneI : ⇑basisOneI = ![1, I] :=
funext fun i =>
Basis.apply_eq_iff.mpr <|
Finsupp.ext fun j => by
fin_cases i <;> fin_cases j <;>
-- Porting note: removed `only`, consider squeezing again
simp [coe_basisOneI_repr, Finsupp.single_eq_of_ne, Matrix.cons_val_zero,
Matrix.cons_val_one, Matrix.head_cons, Fin.one_eq_zero_iff, Ne, not_false_iff, I_re,
Nat.succ_succ_ne_one, one_im, I_im, one_re, Finsupp.single_eq_same, Fin.zero_eq_one_iff]
set_option linter.uppercaseLean3 false in
#align complex.coe_basis_one_I Complex.coe_basisOneI
instance : FiniteDimensional ℝ ℂ :=
of_fintype_basis basisOneI
@[simp]
theorem finrank_real_complex : FiniteDimensional.finrank ℝ ℂ = 2 := by
rw [finrank_eq_card_basis basisOneI, Fintype.card_fin]
#align complex.finrank_real_complex Complex.finrank_real_complex
@[simp]
| Mathlib/Data/Complex/Module.lean | 176 | 176 | theorem rank_real_complex : Module.rank ℝ ℂ = 2 := by | simp [← finrank_eq_rank, finrank_real_complex]
|
import Mathlib.Algebra.Order.Ring.Defs
import Mathlib.Algebra.Group.Int
import Mathlib.Data.Nat.Dist
import Mathlib.Data.Ordmap.Ordnode
import Mathlib.Tactic.Abel
import Mathlib.Tactic.Linarith
#align_import data.ordmap.ordset from "leanprover-community/mathlib"@"47b51515e69f59bca5cf34ef456e6000fe205a69"
variable {α : Type*}
namespace Ordnode
theorem not_le_delta {s} (H : 1 ≤ s) : ¬s ≤ delta * 0 :=
not_le_of_gt H
#align ordnode.not_le_delta Ordnode.not_le_delta
theorem delta_lt_false {a b : ℕ} (h₁ : delta * a < b) (h₂ : delta * b < a) : False :=
not_le_of_lt (lt_trans ((mul_lt_mul_left (by decide)).2 h₁) h₂) <| by
simpa [mul_assoc] using Nat.mul_le_mul_right a (by decide : 1 ≤ delta * delta)
#align ordnode.delta_lt_false Ordnode.delta_lt_false
def realSize : Ordnode α → ℕ
| nil => 0
| node _ l _ r => realSize l + realSize r + 1
#align ordnode.real_size Ordnode.realSize
def Sized : Ordnode α → Prop
| nil => True
| node s l _ r => s = size l + size r + 1 ∧ Sized l ∧ Sized r
#align ordnode.sized Ordnode.Sized
theorem Sized.node' {l x r} (hl : @Sized α l) (hr : Sized r) : Sized (node' l x r) :=
⟨rfl, hl, hr⟩
#align ordnode.sized.node' Ordnode.Sized.node'
theorem Sized.eq_node' {s l x r} (h : @Sized α (node s l x r)) : node s l x r = .node' l x r := by
rw [h.1]
#align ordnode.sized.eq_node' Ordnode.Sized.eq_node'
theorem Sized.size_eq {s l x r} (H : Sized (@node α s l x r)) :
size (@node α s l x r) = size l + size r + 1 :=
H.1
#align ordnode.sized.size_eq Ordnode.Sized.size_eq
@[elab_as_elim]
theorem Sized.induction {t} (hl : @Sized α t) {C : Ordnode α → Prop} (H0 : C nil)
(H1 : ∀ l x r, C l → C r → C (.node' l x r)) : C t := by
induction t with
| nil => exact H0
| node _ _ _ _ t_ih_l t_ih_r =>
rw [hl.eq_node']
exact H1 _ _ _ (t_ih_l hl.2.1) (t_ih_r hl.2.2)
#align ordnode.sized.induction Ordnode.Sized.induction
theorem size_eq_realSize : ∀ {t : Ordnode α}, Sized t → size t = realSize t
| nil, _ => rfl
| node s l x r, ⟨h₁, h₂, h₃⟩ => by
rw [size, h₁, size_eq_realSize h₂, size_eq_realSize h₃]; rfl
#align ordnode.size_eq_real_size Ordnode.size_eq_realSize
@[simp]
theorem Sized.size_eq_zero {t : Ordnode α} (ht : Sized t) : size t = 0 ↔ t = nil := by
cases t <;> [simp;simp [ht.1]]
#align ordnode.sized.size_eq_zero Ordnode.Sized.size_eq_zero
theorem Sized.pos {s l x r} (h : Sized (@node α s l x r)) : 0 < s := by
rw [h.1]; apply Nat.le_add_left
#align ordnode.sized.pos Ordnode.Sized.pos
theorem dual_dual : ∀ t : Ordnode α, dual (dual t) = t
| nil => rfl
| node s l x r => by rw [dual, dual, dual_dual l, dual_dual r]
#align ordnode.dual_dual Ordnode.dual_dual
@[simp]
theorem size_dual (t : Ordnode α) : size (dual t) = size t := by cases t <;> rfl
#align ordnode.size_dual Ordnode.size_dual
def BalancedSz (l r : ℕ) : Prop :=
l + r ≤ 1 ∨ l ≤ delta * r ∧ r ≤ delta * l
#align ordnode.balanced_sz Ordnode.BalancedSz
instance BalancedSz.dec : DecidableRel BalancedSz := fun _ _ => Or.decidable
#align ordnode.balanced_sz.dec Ordnode.BalancedSz.dec
def Balanced : Ordnode α → Prop
| nil => True
| node _ l _ r => BalancedSz (size l) (size r) ∧ Balanced l ∧ Balanced r
#align ordnode.balanced Ordnode.Balanced
instance Balanced.dec : DecidablePred (@Balanced α)
| nil => by
unfold Balanced
infer_instance
| node _ l _ r => by
unfold Balanced
haveI := Balanced.dec l
haveI := Balanced.dec r
infer_instance
#align ordnode.balanced.dec Ordnode.Balanced.dec
@[symm]
theorem BalancedSz.symm {l r : ℕ} : BalancedSz l r → BalancedSz r l :=
Or.imp (by rw [add_comm]; exact id) And.symm
#align ordnode.balanced_sz.symm Ordnode.BalancedSz.symm
theorem balancedSz_zero {l : ℕ} : BalancedSz l 0 ↔ l ≤ 1 := by
simp (config := { contextual := true }) [BalancedSz]
#align ordnode.balanced_sz_zero Ordnode.balancedSz_zero
theorem balancedSz_up {l r₁ r₂ : ℕ} (h₁ : r₁ ≤ r₂) (h₂ : l + r₂ ≤ 1 ∨ r₂ ≤ delta * l)
(H : BalancedSz l r₁) : BalancedSz l r₂ := by
refine or_iff_not_imp_left.2 fun h => ?_
refine ⟨?_, h₂.resolve_left h⟩
cases H with
| inl H =>
cases r₂
· cases h (le_trans (Nat.add_le_add_left (Nat.zero_le _) _) H)
· exact le_trans (le_trans (Nat.le_add_right _ _) H) (Nat.le_add_left 1 _)
| inr H =>
exact le_trans H.1 (Nat.mul_le_mul_left _ h₁)
#align ordnode.balanced_sz_up Ordnode.balancedSz_up
theorem balancedSz_down {l r₁ r₂ : ℕ} (h₁ : r₁ ≤ r₂) (h₂ : l + r₂ ≤ 1 ∨ l ≤ delta * r₁)
(H : BalancedSz l r₂) : BalancedSz l r₁ :=
have : l + r₂ ≤ 1 → BalancedSz l r₁ := fun H => Or.inl (le_trans (Nat.add_le_add_left h₁ _) H)
Or.casesOn H this fun H => Or.casesOn h₂ this fun h₂ => Or.inr ⟨h₂, le_trans h₁ H.2⟩
#align ordnode.balanced_sz_down Ordnode.balancedSz_down
theorem Balanced.dual : ∀ {t : Ordnode α}, Balanced t → Balanced (dual t)
| nil, _ => ⟨⟩
| node _ l _ r, ⟨b, bl, br⟩ => ⟨by rw [size_dual, size_dual]; exact b.symm, br.dual, bl.dual⟩
#align ordnode.balanced.dual Ordnode.Balanced.dual
def node3L (l : Ordnode α) (x : α) (m : Ordnode α) (y : α) (r : Ordnode α) : Ordnode α :=
node' (node' l x m) y r
#align ordnode.node3_l Ordnode.node3L
def node3R (l : Ordnode α) (x : α) (m : Ordnode α) (y : α) (r : Ordnode α) : Ordnode α :=
node' l x (node' m y r)
#align ordnode.node3_r Ordnode.node3R
def node4L : Ordnode α → α → Ordnode α → α → Ordnode α → Ordnode α
| l, x, node _ ml y mr, z, r => node' (node' l x ml) y (node' mr z r)
| l, x, nil, z, r => node3L l x nil z r
#align ordnode.node4_l Ordnode.node4L
-- should not happen
def node4R : Ordnode α → α → Ordnode α → α → Ordnode α → Ordnode α
| l, x, node _ ml y mr, z, r => node' (node' l x ml) y (node' mr z r)
| l, x, nil, z, r => node3R l x nil z r
#align ordnode.node4_r Ordnode.node4R
-- should not happen
def rotateL : Ordnode α → α → Ordnode α → Ordnode α
| l, x, node _ m y r => if size m < ratio * size r then node3L l x m y r else node4L l x m y r
| l, x, nil => node' l x nil
#align ordnode.rotate_l Ordnode.rotateL
-- Porting note (#11467): during the port we marked these lemmas with `@[eqns]`
-- to emulate the old Lean 3 behaviour.
theorem rotateL_node (l : Ordnode α) (x : α) (sz : ℕ) (m : Ordnode α) (y : α) (r : Ordnode α) :
rotateL l x (node sz m y r) =
if size m < ratio * size r then node3L l x m y r else node4L l x m y r :=
rfl
theorem rotateL_nil (l : Ordnode α) (x : α) : rotateL l x nil = node' l x nil :=
rfl
-- should not happen
def rotateR : Ordnode α → α → Ordnode α → Ordnode α
| node _ l x m, y, r => if size m < ratio * size l then node3R l x m y r else node4R l x m y r
| nil, y, r => node' nil y r
#align ordnode.rotate_r Ordnode.rotateR
-- Porting note (#11467): during the port we marked these lemmas with `@[eqns]`
-- to emulate the old Lean 3 behaviour.
theorem rotateR_node (sz : ℕ) (l : Ordnode α) (x : α) (m : Ordnode α) (y : α) (r : Ordnode α) :
rotateR (node sz l x m) y r =
if size m < ratio * size l then node3R l x m y r else node4R l x m y r :=
rfl
theorem rotateR_nil (y : α) (r : Ordnode α) : rotateR nil y r = node' nil y r :=
rfl
-- should not happen
def balanceL' (l : Ordnode α) (x : α) (r : Ordnode α) : Ordnode α :=
if size l + size r ≤ 1 then node' l x r
else if size l > delta * size r then rotateR l x r else node' l x r
#align ordnode.balance_l' Ordnode.balanceL'
def balanceR' (l : Ordnode α) (x : α) (r : Ordnode α) : Ordnode α :=
if size l + size r ≤ 1 then node' l x r
else if size r > delta * size l then rotateL l x r else node' l x r
#align ordnode.balance_r' Ordnode.balanceR'
def balance' (l : Ordnode α) (x : α) (r : Ordnode α) : Ordnode α :=
if size l + size r ≤ 1 then node' l x r
else
if size r > delta * size l then rotateL l x r
else if size l > delta * size r then rotateR l x r else node' l x r
#align ordnode.balance' Ordnode.balance'
theorem dual_node' (l : Ordnode α) (x : α) (r : Ordnode α) :
dual (node' l x r) = node' (dual r) x (dual l) := by simp [node', add_comm]
#align ordnode.dual_node' Ordnode.dual_node'
theorem dual_node3L (l : Ordnode α) (x : α) (m : Ordnode α) (y : α) (r : Ordnode α) :
dual (node3L l x m y r) = node3R (dual r) y (dual m) x (dual l) := by
simp [node3L, node3R, dual_node', add_comm]
#align ordnode.dual_node3_l Ordnode.dual_node3L
theorem dual_node3R (l : Ordnode α) (x : α) (m : Ordnode α) (y : α) (r : Ordnode α) :
dual (node3R l x m y r) = node3L (dual r) y (dual m) x (dual l) := by
simp [node3L, node3R, dual_node', add_comm]
#align ordnode.dual_node3_r Ordnode.dual_node3R
theorem dual_node4L (l : Ordnode α) (x : α) (m : Ordnode α) (y : α) (r : Ordnode α) :
dual (node4L l x m y r) = node4R (dual r) y (dual m) x (dual l) := by
cases m <;> simp [node4L, node4R, node3R, dual_node3L, dual_node', add_comm]
#align ordnode.dual_node4_l Ordnode.dual_node4L
theorem dual_node4R (l : Ordnode α) (x : α) (m : Ordnode α) (y : α) (r : Ordnode α) :
dual (node4R l x m y r) = node4L (dual r) y (dual m) x (dual l) := by
cases m <;> simp [node4L, node4R, node3L, dual_node3R, dual_node', add_comm]
#align ordnode.dual_node4_r Ordnode.dual_node4R
theorem dual_rotateL (l : Ordnode α) (x : α) (r : Ordnode α) :
dual (rotateL l x r) = rotateR (dual r) x (dual l) := by
cases r <;> simp [rotateL, rotateR, dual_node']; split_ifs <;>
simp [dual_node3L, dual_node4L, node3R, add_comm]
#align ordnode.dual_rotate_l Ordnode.dual_rotateL
theorem dual_rotateR (l : Ordnode α) (x : α) (r : Ordnode α) :
dual (rotateR l x r) = rotateL (dual r) x (dual l) := by
rw [← dual_dual (rotateL _ _ _), dual_rotateL, dual_dual, dual_dual]
#align ordnode.dual_rotate_r Ordnode.dual_rotateR
theorem dual_balance' (l : Ordnode α) (x : α) (r : Ordnode α) :
dual (balance' l x r) = balance' (dual r) x (dual l) := by
simp [balance', add_comm]; split_ifs with h h_1 h_2 <;>
simp [dual_node', dual_rotateL, dual_rotateR, add_comm]
cases delta_lt_false h_1 h_2
#align ordnode.dual_balance' Ordnode.dual_balance'
theorem dual_balanceL (l : Ordnode α) (x : α) (r : Ordnode α) :
dual (balanceL l x r) = balanceR (dual r) x (dual l) := by
unfold balanceL balanceR
cases' r with rs rl rx rr
· cases' l with ls ll lx lr; · rfl
cases' ll with lls lll llx llr <;> cases' lr with lrs lrl lrx lrr <;> dsimp only [dual, id] <;>
try rfl
split_ifs with h <;> repeat simp [h, add_comm]
· cases' l with ls ll lx lr; · rfl
dsimp only [dual, id]
split_ifs; swap; · simp [add_comm]
cases' ll with lls lll llx llr <;> cases' lr with lrs lrl lrx lrr <;> try rfl
dsimp only [dual, id]
split_ifs with h <;> simp [h, add_comm]
#align ordnode.dual_balance_l Ordnode.dual_balanceL
theorem dual_balanceR (l : Ordnode α) (x : α) (r : Ordnode α) :
dual (balanceR l x r) = balanceL (dual r) x (dual l) := by
rw [← dual_dual (balanceL _ _ _), dual_balanceL, dual_dual, dual_dual]
#align ordnode.dual_balance_r Ordnode.dual_balanceR
theorem Sized.node3L {l x m y r} (hl : @Sized α l) (hm : Sized m) (hr : Sized r) :
Sized (node3L l x m y r) :=
(hl.node' hm).node' hr
#align ordnode.sized.node3_l Ordnode.Sized.node3L
theorem Sized.node3R {l x m y r} (hl : @Sized α l) (hm : Sized m) (hr : Sized r) :
Sized (node3R l x m y r) :=
hl.node' (hm.node' hr)
#align ordnode.sized.node3_r Ordnode.Sized.node3R
theorem Sized.node4L {l x m y r} (hl : @Sized α l) (hm : Sized m) (hr : Sized r) :
Sized (node4L l x m y r) := by
cases m <;> [exact (hl.node' hm).node' hr; exact (hl.node' hm.2.1).node' (hm.2.2.node' hr)]
#align ordnode.sized.node4_l Ordnode.Sized.node4L
theorem node3L_size {l x m y r} : size (@node3L α l x m y r) = size l + size m + size r + 2 := by
dsimp [node3L, node', size]; rw [add_right_comm _ 1]
#align ordnode.node3_l_size Ordnode.node3L_size
theorem node3R_size {l x m y r} : size (@node3R α l x m y r) = size l + size m + size r + 2 := by
dsimp [node3R, node', size]; rw [← add_assoc, ← add_assoc]
#align ordnode.node3_r_size Ordnode.node3R_size
theorem node4L_size {l x m y r} (hm : Sized m) :
size (@node4L α l x m y r) = size l + size m + size r + 2 := by
cases m <;> simp [node4L, node3L, node'] <;> [abel; (simp [size, hm.1]; abel)]
#align ordnode.node4_l_size Ordnode.node4L_size
theorem Sized.dual : ∀ {t : Ordnode α}, Sized t → Sized (dual t)
| nil, _ => ⟨⟩
| node _ l _ r, ⟨rfl, sl, sr⟩ => ⟨by simp [size_dual, add_comm], Sized.dual sr, Sized.dual sl⟩
#align ordnode.sized.dual Ordnode.Sized.dual
theorem Sized.dual_iff {t : Ordnode α} : Sized (.dual t) ↔ Sized t :=
⟨fun h => by rw [← dual_dual t]; exact h.dual, Sized.dual⟩
#align ordnode.sized.dual_iff Ordnode.Sized.dual_iff
theorem Sized.rotateL {l x r} (hl : @Sized α l) (hr : Sized r) : Sized (rotateL l x r) := by
cases r; · exact hl.node' hr
rw [Ordnode.rotateL_node]; split_ifs
· exact hl.node3L hr.2.1 hr.2.2
· exact hl.node4L hr.2.1 hr.2.2
#align ordnode.sized.rotate_l Ordnode.Sized.rotateL
theorem Sized.rotateR {l x r} (hl : @Sized α l) (hr : Sized r) : Sized (rotateR l x r) :=
Sized.dual_iff.1 <| by rw [dual_rotateR]; exact hr.dual.rotateL hl.dual
#align ordnode.sized.rotate_r Ordnode.Sized.rotateR
theorem Sized.rotateL_size {l x r} (hm : Sized r) :
size (@Ordnode.rotateL α l x r) = size l + size r + 1 := by
cases r <;> simp [Ordnode.rotateL]
simp only [hm.1]
split_ifs <;> simp [node3L_size, node4L_size hm.2.1] <;> abel
#align ordnode.sized.rotate_l_size Ordnode.Sized.rotateL_size
theorem Sized.rotateR_size {l x r} (hl : Sized l) :
size (@Ordnode.rotateR α l x r) = size l + size r + 1 := by
rw [← size_dual, dual_rotateR, hl.dual.rotateL_size, size_dual, size_dual, add_comm (size l)]
#align ordnode.sized.rotate_r_size Ordnode.Sized.rotateR_size
theorem Sized.balance' {l x r} (hl : @Sized α l) (hr : Sized r) : Sized (balance' l x r) := by
unfold balance'; split_ifs
· exact hl.node' hr
· exact hl.rotateL hr
· exact hl.rotateR hr
· exact hl.node' hr
#align ordnode.sized.balance' Ordnode.Sized.balance'
theorem size_balance' {l x r} (hl : @Sized α l) (hr : Sized r) :
size (@balance' α l x r) = size l + size r + 1 := by
unfold balance'; split_ifs
· rfl
· exact hr.rotateL_size
· exact hl.rotateR_size
· rfl
#align ordnode.size_balance' Ordnode.size_balance'
theorem All.imp {P Q : α → Prop} (H : ∀ a, P a → Q a) : ∀ {t}, All P t → All Q t
| nil, _ => ⟨⟩
| node _ _ _ _, ⟨h₁, h₂, h₃⟩ => ⟨h₁.imp H, H _ h₂, h₃.imp H⟩
#align ordnode.all.imp Ordnode.All.imp
theorem Any.imp {P Q : α → Prop} (H : ∀ a, P a → Q a) : ∀ {t}, Any P t → Any Q t
| nil => id
| node _ _ _ _ => Or.imp (Any.imp H) <| Or.imp (H _) (Any.imp H)
#align ordnode.any.imp Ordnode.Any.imp
theorem all_singleton {P : α → Prop} {x : α} : All P (singleton x) ↔ P x :=
⟨fun h => h.2.1, fun h => ⟨⟨⟩, h, ⟨⟩⟩⟩
#align ordnode.all_singleton Ordnode.all_singleton
theorem any_singleton {P : α → Prop} {x : α} : Any P (singleton x) ↔ P x :=
⟨by rintro (⟨⟨⟩⟩ | h | ⟨⟨⟩⟩); exact h, fun h => Or.inr (Or.inl h)⟩
#align ordnode.any_singleton Ordnode.any_singleton
theorem all_dual {P : α → Prop} : ∀ {t : Ordnode α}, All P (dual t) ↔ All P t
| nil => Iff.rfl
| node _ _l _x _r =>
⟨fun ⟨hr, hx, hl⟩ => ⟨all_dual.1 hl, hx, all_dual.1 hr⟩, fun ⟨hl, hx, hr⟩ =>
⟨all_dual.2 hr, hx, all_dual.2 hl⟩⟩
#align ordnode.all_dual Ordnode.all_dual
theorem all_iff_forall {P : α → Prop} : ∀ {t}, All P t ↔ ∀ x, Emem x t → P x
| nil => (iff_true_intro <| by rintro _ ⟨⟩).symm
| node _ l x r => by simp [All, Emem, all_iff_forall, Any, or_imp, forall_and]
#align ordnode.all_iff_forall Ordnode.all_iff_forall
theorem any_iff_exists {P : α → Prop} : ∀ {t}, Any P t ↔ ∃ x, Emem x t ∧ P x
| nil => ⟨by rintro ⟨⟩, by rintro ⟨_, ⟨⟩, _⟩⟩
| node _ l x r => by simp only [Emem]; simp [Any, any_iff_exists, or_and_right, exists_or]
#align ordnode.any_iff_exists Ordnode.any_iff_exists
theorem emem_iff_all {x : α} {t} : Emem x t ↔ ∀ P, All P t → P x :=
⟨fun h _ al => all_iff_forall.1 al _ h, fun H => H _ <| all_iff_forall.2 fun _ => id⟩
#align ordnode.emem_iff_all Ordnode.emem_iff_all
theorem all_node' {P l x r} : @All α P (node' l x r) ↔ All P l ∧ P x ∧ All P r :=
Iff.rfl
#align ordnode.all_node' Ordnode.all_node'
theorem all_node3L {P l x m y r} :
@All α P (node3L l x m y r) ↔ All P l ∧ P x ∧ All P m ∧ P y ∧ All P r := by
simp [node3L, all_node', and_assoc]
#align ordnode.all_node3_l Ordnode.all_node3L
theorem all_node3R {P l x m y r} :
@All α P (node3R l x m y r) ↔ All P l ∧ P x ∧ All P m ∧ P y ∧ All P r :=
Iff.rfl
#align ordnode.all_node3_r Ordnode.all_node3R
theorem all_node4L {P l x m y r} :
@All α P (node4L l x m y r) ↔ All P l ∧ P x ∧ All P m ∧ P y ∧ All P r := by
cases m <;> simp [node4L, all_node', All, all_node3L, and_assoc]
#align ordnode.all_node4_l Ordnode.all_node4L
theorem all_node4R {P l x m y r} :
@All α P (node4R l x m y r) ↔ All P l ∧ P x ∧ All P m ∧ P y ∧ All P r := by
cases m <;> simp [node4R, all_node', All, all_node3R, and_assoc]
#align ordnode.all_node4_r Ordnode.all_node4R
theorem all_rotateL {P l x r} : @All α P (rotateL l x r) ↔ All P l ∧ P x ∧ All P r := by
cases r <;> simp [rotateL, all_node']; split_ifs <;>
simp [all_node3L, all_node4L, All, and_assoc]
#align ordnode.all_rotate_l Ordnode.all_rotateL
theorem all_rotateR {P l x r} : @All α P (rotateR l x r) ↔ All P l ∧ P x ∧ All P r := by
rw [← all_dual, dual_rotateR, all_rotateL]; simp [all_dual, and_comm, and_left_comm, and_assoc]
#align ordnode.all_rotate_r Ordnode.all_rotateR
theorem all_balance' {P l x r} : @All α P (balance' l x r) ↔ All P l ∧ P x ∧ All P r := by
rw [balance']; split_ifs <;> simp [all_node', all_rotateL, all_rotateR]
#align ordnode.all_balance' Ordnode.all_balance'
theorem foldr_cons_eq_toList : ∀ (t : Ordnode α) (r : List α), t.foldr List.cons r = toList t ++ r
| nil, r => rfl
| node _ l x r, r' => by
rw [foldr, foldr_cons_eq_toList l, foldr_cons_eq_toList r, ← List.cons_append,
← List.append_assoc, ← foldr_cons_eq_toList l]; rfl
#align ordnode.foldr_cons_eq_to_list Ordnode.foldr_cons_eq_toList
@[simp]
theorem toList_nil : toList (@nil α) = [] :=
rfl
#align ordnode.to_list_nil Ordnode.toList_nil
@[simp]
theorem toList_node (s l x r) : toList (@node α s l x r) = toList l ++ x :: toList r := by
rw [toList, foldr, foldr_cons_eq_toList]; rfl
#align ordnode.to_list_node Ordnode.toList_node
theorem emem_iff_mem_toList {x : α} {t} : Emem x t ↔ x ∈ toList t := by
unfold Emem; induction t <;> simp [Any, *, or_assoc]
#align ordnode.emem_iff_mem_to_list Ordnode.emem_iff_mem_toList
theorem length_toList' : ∀ t : Ordnode α, (toList t).length = t.realSize
| nil => rfl
| node _ l _ r => by
rw [toList_node, List.length_append, List.length_cons, length_toList' l,
length_toList' r]; rfl
#align ordnode.length_to_list' Ordnode.length_toList'
theorem length_toList {t : Ordnode α} (h : Sized t) : (toList t).length = t.size := by
rw [length_toList', size_eq_realSize h]
#align ordnode.length_to_list Ordnode.length_toList
theorem equiv_iff {t₁ t₂ : Ordnode α} (h₁ : Sized t₁) (h₂ : Sized t₂) :
Equiv t₁ t₂ ↔ toList t₁ = toList t₂ :=
and_iff_right_of_imp fun h => by rw [← length_toList h₁, h, length_toList h₂]
#align ordnode.equiv_iff Ordnode.equiv_iff
theorem pos_size_of_mem [LE α] [@DecidableRel α (· ≤ ·)] {x : α} {t : Ordnode α} (h : Sized t)
(h_mem : x ∈ t) : 0 < size t := by cases t; · { contradiction }; · { simp [h.1] }
#align ordnode.pos_size_of_mem Ordnode.pos_size_of_mem
theorem findMin'_dual : ∀ (t) (x : α), findMin' (dual t) x = findMax' x t
| nil, _ => rfl
| node _ _ x r, _ => findMin'_dual r x
#align ordnode.find_min'_dual Ordnode.findMin'_dual
theorem findMax'_dual (t) (x : α) : findMax' x (dual t) = findMin' t x := by
rw [← findMin'_dual, dual_dual]
#align ordnode.find_max'_dual Ordnode.findMax'_dual
theorem findMin_dual : ∀ t : Ordnode α, findMin (dual t) = findMax t
| nil => rfl
| node _ _ _ _ => congr_arg some <| findMin'_dual _ _
#align ordnode.find_min_dual Ordnode.findMin_dual
theorem findMax_dual (t : Ordnode α) : findMax (dual t) = findMin t := by
rw [← findMin_dual, dual_dual]
#align ordnode.find_max_dual Ordnode.findMax_dual
theorem dual_eraseMin : ∀ t : Ordnode α, dual (eraseMin t) = eraseMax (dual t)
| nil => rfl
| node _ nil x r => rfl
| node _ (node sz l' y r') x r => by
rw [eraseMin, dual_balanceR, dual_eraseMin (node sz l' y r'), dual, dual, dual, eraseMax]
#align ordnode.dual_erase_min Ordnode.dual_eraseMin
theorem dual_eraseMax (t : Ordnode α) : dual (eraseMax t) = eraseMin (dual t) := by
rw [← dual_dual (eraseMin _), dual_eraseMin, dual_dual]
#align ordnode.dual_erase_max Ordnode.dual_eraseMax
theorem splitMin_eq :
∀ (s l) (x : α) (r), splitMin' l x r = (findMin' l x, eraseMin (node s l x r))
| _, nil, x, r => rfl
| _, node ls ll lx lr, x, r => by rw [splitMin', splitMin_eq ls ll lx lr, findMin', eraseMin]
#align ordnode.split_min_eq Ordnode.splitMin_eq
theorem splitMax_eq :
∀ (s l) (x : α) (r), splitMax' l x r = (eraseMax (node s l x r), findMax' x r)
| _, l, x, nil => rfl
| _, l, x, node ls ll lx lr => by rw [splitMax', splitMax_eq ls ll lx lr, findMax', eraseMax]
#align ordnode.split_max_eq Ordnode.splitMax_eq
-- @[elab_as_elim] -- Porting note: unexpected eliminator resulting type
theorem findMin'_all {P : α → Prop} : ∀ (t) (x : α), All P t → P x → P (findMin' t x)
| nil, _x, _, hx => hx
| node _ ll lx _, _, ⟨h₁, h₂, _⟩, _ => findMin'_all ll lx h₁ h₂
#align ordnode.find_min'_all Ordnode.findMin'_all
-- @[elab_as_elim] -- Porting note: unexpected eliminator resulting type
theorem findMax'_all {P : α → Prop} : ∀ (x : α) (t), P x → All P t → P (findMax' x t)
| _x, nil, hx, _ => hx
| _, node _ _ lx lr, _, ⟨_, h₂, h₃⟩ => findMax'_all lx lr h₂ h₃
#align ordnode.find_max'_all Ordnode.findMax'_all
@[simp]
| Mathlib/Data/Ordmap/Ordset.lean | 641 | 641 | theorem merge_nil_left (t : Ordnode α) : merge t nil = t := by | cases t <;> rfl
|
import Mathlib.Analysis.Convex.Hull
#align_import analysis.convex.join from "leanprover-community/mathlib"@"951bf1d9e98a2042979ced62c0620bcfb3587cf8"
open Set
variable {ι : Sort*} {𝕜 E : Type*}
section OrderedSemiring
variable (𝕜) [OrderedSemiring 𝕜] [AddCommMonoid E] [Module 𝕜 E] {s t s₁ s₂ t₁ t₂ u : Set E}
{x y : E}
def convexJoin (s t : Set E) : Set E :=
⋃ (x ∈ s) (y ∈ t), segment 𝕜 x y
#align convex_join convexJoin
variable {𝕜}
theorem mem_convexJoin : x ∈ convexJoin 𝕜 s t ↔ ∃ a ∈ s, ∃ b ∈ t, x ∈ segment 𝕜 a b := by
simp [convexJoin]
#align mem_convex_join mem_convexJoin
theorem convexJoin_comm (s t : Set E) : convexJoin 𝕜 s t = convexJoin 𝕜 t s :=
(iUnion₂_comm _).trans <| by simp_rw [convexJoin, segment_symm]
#align convex_join_comm convexJoin_comm
theorem convexJoin_mono (hs : s₁ ⊆ s₂) (ht : t₁ ⊆ t₂) : convexJoin 𝕜 s₁ t₁ ⊆ convexJoin 𝕜 s₂ t₂ :=
biUnion_mono hs fun _ _ => biUnion_subset_biUnion_left ht
#align convex_join_mono convexJoin_mono
theorem convexJoin_mono_left (hs : s₁ ⊆ s₂) : convexJoin 𝕜 s₁ t ⊆ convexJoin 𝕜 s₂ t :=
convexJoin_mono hs Subset.rfl
#align convex_join_mono_left convexJoin_mono_left
theorem convexJoin_mono_right (ht : t₁ ⊆ t₂) : convexJoin 𝕜 s t₁ ⊆ convexJoin 𝕜 s t₂ :=
convexJoin_mono Subset.rfl ht
#align convex_join_mono_right convexJoin_mono_right
@[simp]
theorem convexJoin_empty_left (t : Set E) : convexJoin 𝕜 ∅ t = ∅ := by simp [convexJoin]
#align convex_join_empty_left convexJoin_empty_left
@[simp]
theorem convexJoin_empty_right (s : Set E) : convexJoin 𝕜 s ∅ = ∅ := by simp [convexJoin]
#align convex_join_empty_right convexJoin_empty_right
@[simp]
theorem convexJoin_singleton_left (t : Set E) (x : E) :
convexJoin 𝕜 {x} t = ⋃ y ∈ t, segment 𝕜 x y := by simp [convexJoin]
#align convex_join_singleton_left convexJoin_singleton_left
@[simp]
theorem convexJoin_singleton_right (s : Set E) (y : E) :
convexJoin 𝕜 s {y} = ⋃ x ∈ s, segment 𝕜 x y := by simp [convexJoin]
#align convex_join_singleton_right convexJoin_singleton_right
-- Porting note (#10618): simp can prove it
theorem convexJoin_singletons (x : E) : convexJoin 𝕜 {x} {y} = segment 𝕜 x y := by simp
#align convex_join_singletons convexJoin_singletons
@[simp]
theorem convexJoin_union_left (s₁ s₂ t : Set E) :
convexJoin 𝕜 (s₁ ∪ s₂) t = convexJoin 𝕜 s₁ t ∪ convexJoin 𝕜 s₂ t := by
simp_rw [convexJoin, mem_union, iUnion_or, iUnion_union_distrib]
#align convex_join_union_left convexJoin_union_left
@[simp]
theorem convexJoin_union_right (s t₁ t₂ : Set E) :
convexJoin 𝕜 s (t₁ ∪ t₂) = convexJoin 𝕜 s t₁ ∪ convexJoin 𝕜 s t₂ := by
simp_rw [convexJoin_comm s, convexJoin_union_left]
#align convex_join_union_right convexJoin_union_right
@[simp]
| Mathlib/Analysis/Convex/Join.lean | 91 | 94 | theorem convexJoin_iUnion_left (s : ι → Set E) (t : Set E) :
convexJoin 𝕜 (⋃ i, s i) t = ⋃ i, convexJoin 𝕜 (s i) t := by |
simp_rw [convexJoin, mem_iUnion, iUnion_exists]
exact iUnion_comm _
|
import Mathlib.Algebra.BigOperators.Module
import Mathlib.Algebra.Order.Field.Basic
import Mathlib.Order.Filter.ModEq
import Mathlib.Analysis.Asymptotics.Asymptotics
import Mathlib.Analysis.SpecificLimits.Basic
import Mathlib.Data.List.TFAE
import Mathlib.Analysis.NormedSpace.Basic
#align_import analysis.specific_limits.normed from "leanprover-community/mathlib"@"f2ce6086713c78a7f880485f7917ea547a215982"
noncomputable section
open scoped Classical
open Set Function Filter Finset Metric Asymptotics
open scoped Classical
open Topology Nat uniformity NNReal ENNReal
variable {α : Type*} {β : Type*} {ι : Type*}
theorem tendsto_norm_atTop_atTop : Tendsto (norm : ℝ → ℝ) atTop atTop :=
tendsto_abs_atTop_atTop
#align tendsto_norm_at_top_at_top tendsto_norm_atTop_atTop
theorem summable_of_absolute_convergence_real {f : ℕ → ℝ} :
(∃ r, Tendsto (fun n ↦ ∑ i ∈ range n, |f i|) atTop (𝓝 r)) → Summable f
| ⟨r, hr⟩ => by
refine .of_norm ⟨r, (hasSum_iff_tendsto_nat_of_nonneg ?_ _).2 ?_⟩
· exact fun i ↦ norm_nonneg _
· simpa only using hr
#align summable_of_absolute_convergence_real summable_of_absolute_convergence_real
theorem tendsto_norm_zero' {𝕜 : Type*} [NormedAddCommGroup 𝕜] :
Tendsto (norm : 𝕜 → ℝ) (𝓝[≠] 0) (𝓝[>] 0) :=
tendsto_norm_zero.inf <| tendsto_principal_principal.2 fun _ hx ↦ norm_pos_iff.2 hx
#align tendsto_norm_zero' tendsto_norm_zero'
theorem isLittleO_pow_pow_of_lt_left {r₁ r₂ : ℝ} (h₁ : 0 ≤ r₁) (h₂ : r₁ < r₂) :
(fun n : ℕ ↦ r₁ ^ n) =o[atTop] fun n ↦ r₂ ^ n :=
have H : 0 < r₂ := h₁.trans_lt h₂
(isLittleO_of_tendsto fun _ hn ↦ False.elim <| H.ne' <| pow_eq_zero hn) <|
(tendsto_pow_atTop_nhds_zero_of_lt_one
(div_nonneg h₁ (h₁.trans h₂.le)) ((div_lt_one H).2 h₂)).congr fun _ ↦ div_pow _ _ _
#align is_o_pow_pow_of_lt_left isLittleO_pow_pow_of_lt_left
theorem isBigO_pow_pow_of_le_left {r₁ r₂ : ℝ} (h₁ : 0 ≤ r₁) (h₂ : r₁ ≤ r₂) :
(fun n : ℕ ↦ r₁ ^ n) =O[atTop] fun n ↦ r₂ ^ n :=
h₂.eq_or_lt.elim (fun h ↦ h ▸ isBigO_refl _ _) fun h ↦ (isLittleO_pow_pow_of_lt_left h₁ h).isBigO
set_option linter.uppercaseLean3 false in
#align is_O_pow_pow_of_le_left isBigO_pow_pow_of_le_left
theorem isLittleO_pow_pow_of_abs_lt_left {r₁ r₂ : ℝ} (h : |r₁| < |r₂|) :
(fun n : ℕ ↦ r₁ ^ n) =o[atTop] fun n ↦ r₂ ^ n := by
refine (IsLittleO.of_norm_left ?_).of_norm_right
exact (isLittleO_pow_pow_of_lt_left (abs_nonneg r₁) h).congr (pow_abs r₁) (pow_abs r₂)
#align is_o_pow_pow_of_abs_lt_left isLittleO_pow_pow_of_abs_lt_left
open List in
theorem TFAE_exists_lt_isLittleO_pow (f : ℕ → ℝ) (R : ℝ) :
TFAE
[∃ a ∈ Ioo (-R) R, f =o[atTop] (a ^ ·), ∃ a ∈ Ioo 0 R, f =o[atTop] (a ^ ·),
∃ a ∈ Ioo (-R) R, f =O[atTop] (a ^ ·), ∃ a ∈ Ioo 0 R, f =O[atTop] (a ^ ·),
∃ a < R, ∃ C : ℝ, (0 < C ∨ 0 < R) ∧ ∀ n, |f n| ≤ C * a ^ n,
∃ a ∈ Ioo 0 R, ∃ C > 0, ∀ n, |f n| ≤ C * a ^ n, ∃ a < R, ∀ᶠ n in atTop, |f n| ≤ a ^ n,
∃ a ∈ Ioo 0 R, ∀ᶠ n in atTop, |f n| ≤ a ^ n] := by
have A : Ico 0 R ⊆ Ioo (-R) R :=
fun x hx ↦ ⟨(neg_lt_zero.2 (hx.1.trans_lt hx.2)).trans_le hx.1, hx.2⟩
have B : Ioo 0 R ⊆ Ioo (-R) R := Subset.trans Ioo_subset_Ico_self A
-- First we prove that 1-4 are equivalent using 2 → 3 → 4, 1 → 3, and 2 → 1
tfae_have 1 → 3
· exact fun ⟨a, ha, H⟩ ↦ ⟨a, ha, H.isBigO⟩
tfae_have 2 → 1
· exact fun ⟨a, ha, H⟩ ↦ ⟨a, B ha, H⟩
tfae_have 3 → 2
· rintro ⟨a, ha, H⟩
rcases exists_between (abs_lt.2 ha) with ⟨b, hab, hbR⟩
exact ⟨b, ⟨(abs_nonneg a).trans_lt hab, hbR⟩,
H.trans_isLittleO (isLittleO_pow_pow_of_abs_lt_left (hab.trans_le (le_abs_self b)))⟩
tfae_have 2 → 4
· exact fun ⟨a, ha, H⟩ ↦ ⟨a, ha, H.isBigO⟩
tfae_have 4 → 3
· exact fun ⟨a, ha, H⟩ ↦ ⟨a, B ha, H⟩
-- Add 5 and 6 using 4 → 6 → 5 → 3
tfae_have 4 → 6
· rintro ⟨a, ha, H⟩
rcases bound_of_isBigO_nat_atTop H with ⟨C, hC₀, hC⟩
refine ⟨a, ha, C, hC₀, fun n ↦ ?_⟩
simpa only [Real.norm_eq_abs, abs_pow, abs_of_nonneg ha.1.le] using hC (pow_ne_zero n ha.1.ne')
tfae_have 6 → 5
· exact fun ⟨a, ha, C, H₀, H⟩ ↦ ⟨a, ha.2, C, Or.inl H₀, H⟩
tfae_have 5 → 3
· rintro ⟨a, ha, C, h₀, H⟩
rcases sign_cases_of_C_mul_pow_nonneg fun n ↦ (abs_nonneg _).trans (H n) with (rfl | ⟨hC₀, ha₀⟩)
· obtain rfl : f = 0 := by
ext n
simpa using H n
simp only [lt_irrefl, false_or_iff] at h₀
exact ⟨0, ⟨neg_lt_zero.2 h₀, h₀⟩, isBigO_zero _ _⟩
exact ⟨a, A ⟨ha₀, ha⟩,
isBigO_of_le' _ fun n ↦ (H n).trans <| mul_le_mul_of_nonneg_left (le_abs_self _) hC₀.le⟩
-- Add 7 and 8 using 2 → 8 → 7 → 3
tfae_have 2 → 8
· rintro ⟨a, ha, H⟩
refine ⟨a, ha, (H.def zero_lt_one).mono fun n hn ↦ ?_⟩
rwa [Real.norm_eq_abs, Real.norm_eq_abs, one_mul, abs_pow, abs_of_pos ha.1] at hn
tfae_have 8 → 7
· exact fun ⟨a, ha, H⟩ ↦ ⟨a, ha.2, H⟩
tfae_have 7 → 3
· rintro ⟨a, ha, H⟩
have : 0 ≤ a := nonneg_of_eventually_pow_nonneg (H.mono fun n ↦ (abs_nonneg _).trans)
refine ⟨a, A ⟨this, ha⟩, IsBigO.of_bound 1 ?_⟩
simpa only [Real.norm_eq_abs, one_mul, abs_pow, abs_of_nonneg this]
-- Porting note: used to work without explicitly having 6 → 7
tfae_have 6 → 7
· exact fun h ↦ tfae_8_to_7 <| tfae_2_to_8 <| tfae_3_to_2 <| tfae_5_to_3 <| tfae_6_to_5 h
tfae_finish
#align tfae_exists_lt_is_o_pow TFAE_exists_lt_isLittleO_pow
theorem isLittleO_pow_const_const_pow_of_one_lt {R : Type*} [NormedRing R] (k : ℕ) {r : ℝ}
(hr : 1 < r) : (fun n ↦ (n : R) ^ k : ℕ → R) =o[atTop] fun n ↦ r ^ n := by
have : Tendsto (fun x : ℝ ↦ x ^ k) (𝓝[>] 1) (𝓝 1) :=
((continuous_id.pow k).tendsto' (1 : ℝ) 1 (one_pow _)).mono_left inf_le_left
obtain ⟨r' : ℝ, hr' : r' ^ k < r, h1 : 1 < r'⟩ :=
((this.eventually (gt_mem_nhds hr)).and self_mem_nhdsWithin).exists
have h0 : 0 ≤ r' := zero_le_one.trans h1.le
suffices (fun n ↦ (n : R) ^ k : ℕ → R) =O[atTop] fun n : ℕ ↦ (r' ^ k) ^ n from
this.trans_isLittleO (isLittleO_pow_pow_of_lt_left (pow_nonneg h0 _) hr')
conv in (r' ^ _) ^ _ => rw [← pow_mul, mul_comm, pow_mul]
suffices ∀ n : ℕ, ‖(n : R)‖ ≤ (r' - 1)⁻¹ * ‖(1 : R)‖ * ‖r' ^ n‖ from
(isBigO_of_le' _ this).pow _
intro n
rw [mul_right_comm]
refine n.norm_cast_le.trans (mul_le_mul_of_nonneg_right ?_ (norm_nonneg _))
simpa [_root_.div_eq_inv_mul, Real.norm_eq_abs, abs_of_nonneg h0] using n.cast_le_pow_div_sub h1
#align is_o_pow_const_const_pow_of_one_lt isLittleO_pow_const_const_pow_of_one_lt
theorem isLittleO_coe_const_pow_of_one_lt {R : Type*} [NormedRing R] {r : ℝ} (hr : 1 < r) :
((↑) : ℕ → R) =o[atTop] fun n ↦ r ^ n := by
simpa only [pow_one] using @isLittleO_pow_const_const_pow_of_one_lt R _ 1 _ hr
#align is_o_coe_const_pow_of_one_lt isLittleO_coe_const_pow_of_one_lt
theorem isLittleO_pow_const_mul_const_pow_const_pow_of_norm_lt {R : Type*} [NormedRing R] (k : ℕ)
{r₁ : R} {r₂ : ℝ} (h : ‖r₁‖ < r₂) :
(fun n ↦ (n : R) ^ k * r₁ ^ n : ℕ → R) =o[atTop] fun n ↦ r₂ ^ n := by
by_cases h0 : r₁ = 0
· refine (isLittleO_zero _ _).congr' (mem_atTop_sets.2 <| ⟨1, fun n hn ↦ ?_⟩) EventuallyEq.rfl
simp [zero_pow (one_le_iff_ne_zero.1 hn), h0]
rw [← Ne, ← norm_pos_iff] at h0
have A : (fun n ↦ (n : R) ^ k : ℕ → R) =o[atTop] fun n ↦ (r₂ / ‖r₁‖) ^ n :=
isLittleO_pow_const_const_pow_of_one_lt k ((one_lt_div h0).2 h)
suffices (fun n ↦ r₁ ^ n) =O[atTop] fun n ↦ ‖r₁‖ ^ n by
simpa [div_mul_cancel₀ _ (pow_pos h0 _).ne'] using A.mul_isBigO this
exact IsBigO.of_bound 1 (by simpa using eventually_norm_pow_le r₁)
#align is_o_pow_const_mul_const_pow_const_pow_of_norm_lt isLittleO_pow_const_mul_const_pow_const_pow_of_norm_lt
theorem tendsto_pow_const_div_const_pow_of_one_lt (k : ℕ) {r : ℝ} (hr : 1 < r) :
Tendsto (fun n ↦ (n : ℝ) ^ k / r ^ n : ℕ → ℝ) atTop (𝓝 0) :=
(isLittleO_pow_const_const_pow_of_one_lt k hr).tendsto_div_nhds_zero
#align tendsto_pow_const_div_const_pow_of_one_lt tendsto_pow_const_div_const_pow_of_one_lt
theorem tendsto_pow_const_mul_const_pow_of_abs_lt_one (k : ℕ) {r : ℝ} (hr : |r| < 1) :
Tendsto (fun n ↦ (n : ℝ) ^ k * r ^ n : ℕ → ℝ) atTop (𝓝 0) := by
by_cases h0 : r = 0
· exact tendsto_const_nhds.congr'
(mem_atTop_sets.2 ⟨1, fun n hn ↦ by simp [zero_lt_one.trans_le hn |>.ne', h0]⟩)
have hr' : 1 < |r|⁻¹ := one_lt_inv (abs_pos.2 h0) hr
rw [tendsto_zero_iff_norm_tendsto_zero]
simpa [div_eq_mul_inv] using tendsto_pow_const_div_const_pow_of_one_lt k hr'
#align tendsto_pow_const_mul_const_pow_of_abs_lt_one tendsto_pow_const_mul_const_pow_of_abs_lt_one
theorem tendsto_pow_const_mul_const_pow_of_lt_one (k : ℕ) {r : ℝ} (hr : 0 ≤ r) (h'r : r < 1) :
Tendsto (fun n ↦ (n : ℝ) ^ k * r ^ n : ℕ → ℝ) atTop (𝓝 0) :=
tendsto_pow_const_mul_const_pow_of_abs_lt_one k (abs_lt.2 ⟨neg_one_lt_zero.trans_le hr, h'r⟩)
#align tendsto_pow_const_mul_const_pow_of_lt_one tendsto_pow_const_mul_const_pow_of_lt_one
theorem tendsto_self_mul_const_pow_of_abs_lt_one {r : ℝ} (hr : |r| < 1) :
Tendsto (fun n ↦ n * r ^ n : ℕ → ℝ) atTop (𝓝 0) := by
simpa only [pow_one] using tendsto_pow_const_mul_const_pow_of_abs_lt_one 1 hr
#align tendsto_self_mul_const_pow_of_abs_lt_one tendsto_self_mul_const_pow_of_abs_lt_one
theorem tendsto_self_mul_const_pow_of_lt_one {r : ℝ} (hr : 0 ≤ r) (h'r : r < 1) :
Tendsto (fun n ↦ n * r ^ n : ℕ → ℝ) atTop (𝓝 0) := by
simpa only [pow_one] using tendsto_pow_const_mul_const_pow_of_lt_one 1 hr h'r
#align tendsto_self_mul_const_pow_of_lt_one tendsto_self_mul_const_pow_of_lt_one
theorem tendsto_pow_atTop_nhds_zero_of_norm_lt_one {R : Type*} [NormedRing R] {x : R}
(h : ‖x‖ < 1) :
Tendsto (fun n : ℕ ↦ x ^ n) atTop (𝓝 0) := by
apply squeeze_zero_norm' (eventually_norm_pow_le x)
exact tendsto_pow_atTop_nhds_zero_of_lt_one (norm_nonneg _) h
#align tendsto_pow_at_top_nhds_0_of_norm_lt_1 tendsto_pow_atTop_nhds_zero_of_norm_lt_one
@[deprecated (since := "2024-01-31")]
alias tendsto_pow_atTop_nhds_0_of_norm_lt_1 := tendsto_pow_atTop_nhds_zero_of_norm_lt_one
theorem tendsto_pow_atTop_nhds_zero_of_abs_lt_one {r : ℝ} (h : |r| < 1) :
Tendsto (fun n : ℕ ↦ r ^ n) atTop (𝓝 0) :=
tendsto_pow_atTop_nhds_zero_of_norm_lt_one h
#align tendsto_pow_at_top_nhds_0_of_abs_lt_1 tendsto_pow_atTop_nhds_zero_of_abs_lt_one
@[deprecated (since := "2024-01-31")]
alias tendsto_pow_atTop_nhds_0_of_abs_lt_1 := tendsto_pow_atTop_nhds_zero_of_abs_lt_one
section SummableLeGeometric
variable [SeminormedAddCommGroup α] {r C : ℝ} {f : ℕ → α}
nonrec theorem SeminormedAddCommGroup.cauchySeq_of_le_geometric {C : ℝ} {r : ℝ} (hr : r < 1)
{u : ℕ → α} (h : ∀ n, ‖u n - u (n + 1)‖ ≤ C * r ^ n) : CauchySeq u :=
cauchySeq_of_le_geometric r C hr (by simpa [dist_eq_norm] using h)
#align seminormed_add_comm_group.cauchy_seq_of_le_geometric SeminormedAddCommGroup.cauchySeq_of_le_geometric
theorem dist_partial_sum_le_of_le_geometric (hf : ∀ n, ‖f n‖ ≤ C * r ^ n) (n : ℕ) :
dist (∑ i ∈ range n, f i) (∑ i ∈ range (n + 1), f i) ≤ C * r ^ n := by
rw [sum_range_succ, dist_eq_norm, ← norm_neg, neg_sub, add_sub_cancel_left]
exact hf n
#align dist_partial_sum_le_of_le_geometric dist_partial_sum_le_of_le_geometric
theorem cauchySeq_finset_of_geometric_bound (hr : r < 1) (hf : ∀ n, ‖f n‖ ≤ C * r ^ n) :
CauchySeq fun s : Finset ℕ ↦ ∑ x ∈ s, f x :=
cauchySeq_finset_of_norm_bounded _
(aux_hasSum_of_le_geometric hr (dist_partial_sum_le_of_le_geometric hf)).summable hf
#align cauchy_seq_finset_of_geometric_bound cauchySeq_finset_of_geometric_bound
theorem norm_sub_le_of_geometric_bound_of_hasSum (hr : r < 1) (hf : ∀ n, ‖f n‖ ≤ C * r ^ n) {a : α}
(ha : HasSum f a) (n : ℕ) : ‖(∑ x ∈ Finset.range n, f x) - a‖ ≤ C * r ^ n / (1 - r) := by
rw [← dist_eq_norm]
apply dist_le_of_le_geometric_of_tendsto r C hr (dist_partial_sum_le_of_le_geometric hf)
exact ha.tendsto_sum_nat
#align norm_sub_le_of_geometric_bound_of_has_sum norm_sub_le_of_geometric_bound_of_hasSum
@[simp]
| Mathlib/Analysis/SpecificLimits/Normed.lean | 456 | 458 | theorem dist_partial_sum (u : ℕ → α) (n : ℕ) :
dist (∑ k ∈ range (n + 1), u k) (∑ k ∈ range n, u k) = ‖u n‖ := by |
simp [dist_eq_norm, sum_range_succ]
|
import Mathlib.Data.Nat.Defs
import Mathlib.Data.Option.Basic
import Mathlib.Data.List.Defs
import Mathlib.Init.Data.List.Basic
import Mathlib.Init.Data.List.Instances
import Mathlib.Init.Data.List.Lemmas
import Mathlib.Logic.Unique
import Mathlib.Order.Basic
import Mathlib.Tactic.Common
#align_import data.list.basic from "leanprover-community/mathlib"@"65a1391a0106c9204fe45bc73a039f056558cb83"
assert_not_exists Set.range
assert_not_exists GroupWithZero
assert_not_exists Ring
open Function
open Nat hiding one_pos
namespace List
universe u v w
variable {ι : Type*} {α : Type u} {β : Type v} {γ : Type w} {l₁ l₂ : List α}
-- Porting note: Delete this attribute
-- attribute [inline] List.head!
instance uniqueOfIsEmpty [IsEmpty α] : Unique (List α) :=
{ instInhabitedList with
uniq := fun l =>
match l with
| [] => rfl
| a :: _ => isEmptyElim a }
#align list.unique_of_is_empty List.uniqueOfIsEmpty
instance : Std.LawfulIdentity (α := List α) Append.append [] where
left_id := nil_append
right_id := append_nil
instance : Std.Associative (α := List α) Append.append where
assoc := append_assoc
#align list.cons_ne_nil List.cons_ne_nil
#align list.cons_ne_self List.cons_ne_self
#align list.head_eq_of_cons_eq List.head_eq_of_cons_eqₓ -- implicits order
#align list.tail_eq_of_cons_eq List.tail_eq_of_cons_eqₓ -- implicits order
@[simp] theorem cons_injective {a : α} : Injective (cons a) := fun _ _ => tail_eq_of_cons_eq
#align list.cons_injective List.cons_injective
#align list.cons_inj List.cons_inj
#align list.cons_eq_cons List.cons_eq_cons
theorem singleton_injective : Injective fun a : α => [a] := fun _ _ h => (cons_eq_cons.1 h).1
#align list.singleton_injective List.singleton_injective
theorem singleton_inj {a b : α} : [a] = [b] ↔ a = b :=
singleton_injective.eq_iff
#align list.singleton_inj List.singleton_inj
#align list.exists_cons_of_ne_nil List.exists_cons_of_ne_nil
theorem set_of_mem_cons (l : List α) (a : α) : { x | x ∈ a :: l } = insert a { x | x ∈ l } :=
Set.ext fun _ => mem_cons
#align list.set_of_mem_cons List.set_of_mem_cons
#align list.mem_singleton_self List.mem_singleton_self
#align list.eq_of_mem_singleton List.eq_of_mem_singleton
#align list.mem_singleton List.mem_singleton
#align list.mem_of_mem_cons_of_mem List.mem_of_mem_cons_of_mem
theorem _root_.Decidable.List.eq_or_ne_mem_of_mem [DecidableEq α]
{a b : α} {l : List α} (h : a ∈ b :: l) : a = b ∨ a ≠ b ∧ a ∈ l := by
by_cases hab : a = b
· exact Or.inl hab
· exact ((List.mem_cons.1 h).elim Or.inl (fun h => Or.inr ⟨hab, h⟩))
#align decidable.list.eq_or_ne_mem_of_mem Decidable.List.eq_or_ne_mem_of_mem
#align list.eq_or_ne_mem_of_mem List.eq_or_ne_mem_of_mem
#align list.not_mem_append List.not_mem_append
#align list.ne_nil_of_mem List.ne_nil_of_mem
lemma mem_pair {a b c : α} : a ∈ [b, c] ↔ a = b ∨ a = c := by
rw [mem_cons, mem_singleton]
@[deprecated (since := "2024-03-23")] alias mem_split := append_of_mem
#align list.mem_split List.append_of_mem
#align list.mem_of_ne_of_mem List.mem_of_ne_of_mem
#align list.ne_of_not_mem_cons List.ne_of_not_mem_cons
#align list.not_mem_of_not_mem_cons List.not_mem_of_not_mem_cons
#align list.not_mem_cons_of_ne_of_not_mem List.not_mem_cons_of_ne_of_not_mem
#align list.ne_and_not_mem_of_not_mem_cons List.ne_and_not_mem_of_not_mem_cons
#align list.mem_map List.mem_map
#align list.exists_of_mem_map List.exists_of_mem_map
#align list.mem_map_of_mem List.mem_map_of_memₓ -- implicits order
-- The simpNF linter says that the LHS can be simplified via `List.mem_map`.
-- However this is a higher priority lemma.
-- https://github.com/leanprover/std4/issues/207
@[simp 1100, nolint simpNF]
theorem mem_map_of_injective {f : α → β} (H : Injective f) {a : α} {l : List α} :
f a ∈ map f l ↔ a ∈ l :=
⟨fun m => let ⟨_, m', e⟩ := exists_of_mem_map m; H e ▸ m', mem_map_of_mem _⟩
#align list.mem_map_of_injective List.mem_map_of_injective
@[simp]
theorem _root_.Function.Involutive.exists_mem_and_apply_eq_iff {f : α → α}
(hf : Function.Involutive f) (x : α) (l : List α) : (∃ y : α, y ∈ l ∧ f y = x) ↔ f x ∈ l :=
⟨by rintro ⟨y, h, rfl⟩; rwa [hf y], fun h => ⟨f x, h, hf _⟩⟩
#align function.involutive.exists_mem_and_apply_eq_iff Function.Involutive.exists_mem_and_apply_eq_iff
theorem mem_map_of_involutive {f : α → α} (hf : Involutive f) {a : α} {l : List α} :
a ∈ map f l ↔ f a ∈ l := by rw [mem_map, hf.exists_mem_and_apply_eq_iff]
#align list.mem_map_of_involutive List.mem_map_of_involutive
#align list.forall_mem_map_iff List.forall_mem_map_iffₓ -- universe order
#align list.map_eq_nil List.map_eq_nilₓ -- universe order
attribute [simp] List.mem_join
#align list.mem_join List.mem_join
#align list.exists_of_mem_join List.exists_of_mem_join
#align list.mem_join_of_mem List.mem_join_of_memₓ -- implicits order
attribute [simp] List.mem_bind
#align list.mem_bind List.mem_bindₓ -- implicits order
-- Porting note: bExists in Lean3, And in Lean4
#align list.exists_of_mem_bind List.exists_of_mem_bindₓ -- implicits order
#align list.mem_bind_of_mem List.mem_bind_of_memₓ -- implicits order
#align list.bind_map List.bind_mapₓ -- implicits order
theorem map_bind (g : β → List γ) (f : α → β) :
∀ l : List α, (List.map f l).bind g = l.bind fun a => g (f a)
| [] => rfl
| a :: l => by simp only [cons_bind, map_cons, map_bind _ _ l]
#align list.map_bind List.map_bind
#align list.length_eq_zero List.length_eq_zero
#align list.length_singleton List.length_singleton
#align list.length_pos_of_mem List.length_pos_of_mem
#align list.exists_mem_of_length_pos List.exists_mem_of_length_pos
#align list.length_pos_iff_exists_mem List.length_pos_iff_exists_mem
alias ⟨ne_nil_of_length_pos, length_pos_of_ne_nil⟩ := length_pos
#align list.ne_nil_of_length_pos List.ne_nil_of_length_pos
#align list.length_pos_of_ne_nil List.length_pos_of_ne_nil
theorem length_pos_iff_ne_nil {l : List α} : 0 < length l ↔ l ≠ [] :=
⟨ne_nil_of_length_pos, length_pos_of_ne_nil⟩
#align list.length_pos_iff_ne_nil List.length_pos_iff_ne_nil
#align list.exists_mem_of_ne_nil List.exists_mem_of_ne_nil
#align list.length_eq_one List.length_eq_one
theorem exists_of_length_succ {n} : ∀ l : List α, l.length = n + 1 → ∃ h t, l = h :: t
| [], H => absurd H.symm <| succ_ne_zero n
| h :: t, _ => ⟨h, t, rfl⟩
#align list.exists_of_length_succ List.exists_of_length_succ
@[simp] lemma length_injective_iff : Injective (List.length : List α → ℕ) ↔ Subsingleton α := by
constructor
· intro h; refine ⟨fun x y => ?_⟩; (suffices [x] = [y] by simpa using this); apply h; rfl
· intros hα l1 l2 hl
induction l1 generalizing l2 <;> cases l2
· rfl
· cases hl
· cases hl
· next ih _ _ =>
congr
· exact Subsingleton.elim _ _
· apply ih; simpa using hl
#align list.length_injective_iff List.length_injective_iff
@[simp default+1] -- Porting note: this used to be just @[simp]
lemma length_injective [Subsingleton α] : Injective (length : List α → ℕ) :=
length_injective_iff.mpr inferInstance
#align list.length_injective List.length_injective
theorem length_eq_two {l : List α} : l.length = 2 ↔ ∃ a b, l = [a, b] :=
⟨fun _ => let [a, b] := l; ⟨a, b, rfl⟩, fun ⟨_, _, e⟩ => e ▸ rfl⟩
#align list.length_eq_two List.length_eq_two
theorem length_eq_three {l : List α} : l.length = 3 ↔ ∃ a b c, l = [a, b, c] :=
⟨fun _ => let [a, b, c] := l; ⟨a, b, c, rfl⟩, fun ⟨_, _, _, e⟩ => e ▸ rfl⟩
#align list.length_eq_three List.length_eq_three
#align list.sublist.length_le List.Sublist.length_le
-- ADHOC Porting note: instance from Lean3 core
instance instSingletonList : Singleton α (List α) := ⟨fun x => [x]⟩
#align list.has_singleton List.instSingletonList
-- ADHOC Porting note: instance from Lean3 core
instance [DecidableEq α] : Insert α (List α) := ⟨List.insert⟩
-- ADHOC Porting note: instance from Lean3 core
instance [DecidableEq α] : LawfulSingleton α (List α) :=
{ insert_emptyc_eq := fun x =>
show (if x ∈ ([] : List α) then [] else [x]) = [x] from if_neg (not_mem_nil _) }
#align list.empty_eq List.empty_eq
theorem singleton_eq (x : α) : ({x} : List α) = [x] :=
rfl
#align list.singleton_eq List.singleton_eq
theorem insert_neg [DecidableEq α] {x : α} {l : List α} (h : x ∉ l) :
Insert.insert x l = x :: l :=
insert_of_not_mem h
#align list.insert_neg List.insert_neg
theorem insert_pos [DecidableEq α] {x : α} {l : List α} (h : x ∈ l) : Insert.insert x l = l :=
insert_of_mem h
#align list.insert_pos List.insert_pos
theorem doubleton_eq [DecidableEq α] {x y : α} (h : x ≠ y) : ({x, y} : List α) = [x, y] := by
rw [insert_neg, singleton_eq]
rwa [singleton_eq, mem_singleton]
#align list.doubleton_eq List.doubleton_eq
#align list.forall_mem_nil List.forall_mem_nil
#align list.forall_mem_cons List.forall_mem_cons
theorem forall_mem_of_forall_mem_cons {p : α → Prop} {a : α} {l : List α} (h : ∀ x ∈ a :: l, p x) :
∀ x ∈ l, p x := (forall_mem_cons.1 h).2
#align list.forall_mem_of_forall_mem_cons List.forall_mem_of_forall_mem_cons
#align list.forall_mem_singleton List.forall_mem_singleton
#align list.forall_mem_append List.forall_mem_append
#align list.not_exists_mem_nil List.not_exists_mem_nilₓ -- bExists change
-- Porting note: bExists in Lean3 and And in Lean4
theorem exists_mem_cons_of {p : α → Prop} {a : α} (l : List α) (h : p a) : ∃ x ∈ a :: l, p x :=
⟨a, mem_cons_self _ _, h⟩
#align list.exists_mem_cons_of List.exists_mem_cons_ofₓ -- bExists change
-- Porting note: bExists in Lean3 and And in Lean4
theorem exists_mem_cons_of_exists {p : α → Prop} {a : α} {l : List α} : (∃ x ∈ l, p x) →
∃ x ∈ a :: l, p x :=
fun ⟨x, xl, px⟩ => ⟨x, mem_cons_of_mem _ xl, px⟩
#align list.exists_mem_cons_of_exists List.exists_mem_cons_of_existsₓ -- bExists change
-- Porting note: bExists in Lean3 and And in Lean4
theorem or_exists_of_exists_mem_cons {p : α → Prop} {a : α} {l : List α} : (∃ x ∈ a :: l, p x) →
p a ∨ ∃ x ∈ l, p x :=
fun ⟨x, xal, px⟩ =>
Or.elim (eq_or_mem_of_mem_cons xal) (fun h : x = a => by rw [← h]; left; exact px)
fun h : x ∈ l => Or.inr ⟨x, h, px⟩
#align list.or_exists_of_exists_mem_cons List.or_exists_of_exists_mem_consₓ -- bExists change
theorem exists_mem_cons_iff (p : α → Prop) (a : α) (l : List α) :
(∃ x ∈ a :: l, p x) ↔ p a ∨ ∃ x ∈ l, p x :=
Iff.intro or_exists_of_exists_mem_cons fun h =>
Or.elim h (exists_mem_cons_of l) exists_mem_cons_of_exists
#align list.exists_mem_cons_iff List.exists_mem_cons_iff
instance : IsTrans (List α) Subset where
trans := fun _ _ _ => List.Subset.trans
#align list.subset_def List.subset_def
#align list.subset_append_of_subset_left List.subset_append_of_subset_left
#align list.subset_append_of_subset_right List.subset_append_of_subset_right
#align list.cons_subset List.cons_subset
theorem cons_subset_of_subset_of_mem {a : α} {l m : List α}
(ainm : a ∈ m) (lsubm : l ⊆ m) : a::l ⊆ m :=
cons_subset.2 ⟨ainm, lsubm⟩
#align list.cons_subset_of_subset_of_mem List.cons_subset_of_subset_of_mem
theorem append_subset_of_subset_of_subset {l₁ l₂ l : List α} (l₁subl : l₁ ⊆ l) (l₂subl : l₂ ⊆ l) :
l₁ ++ l₂ ⊆ l :=
fun _ h ↦ (mem_append.1 h).elim (@l₁subl _) (@l₂subl _)
#align list.append_subset_of_subset_of_subset List.append_subset_of_subset_of_subset
-- Porting note: in Batteries
#align list.append_subset_iff List.append_subset
alias ⟨eq_nil_of_subset_nil, _⟩ := subset_nil
#align list.eq_nil_of_subset_nil List.eq_nil_of_subset_nil
#align list.eq_nil_iff_forall_not_mem List.eq_nil_iff_forall_not_mem
#align list.map_subset List.map_subset
theorem map_subset_iff {l₁ l₂ : List α} (f : α → β) (h : Injective f) :
map f l₁ ⊆ map f l₂ ↔ l₁ ⊆ l₂ := by
refine ⟨?_, map_subset f⟩; intro h2 x hx
rcases mem_map.1 (h2 (mem_map_of_mem f hx)) with ⟨x', hx', hxx'⟩
cases h hxx'; exact hx'
#align list.map_subset_iff List.map_subset_iff
theorem append_eq_has_append {L₁ L₂ : List α} : List.append L₁ L₂ = L₁ ++ L₂ :=
rfl
#align list.append_eq_has_append List.append_eq_has_append
#align list.singleton_append List.singleton_append
#align list.append_ne_nil_of_ne_nil_left List.append_ne_nil_of_ne_nil_left
#align list.append_ne_nil_of_ne_nil_right List.append_ne_nil_of_ne_nil_right
#align list.append_eq_nil List.append_eq_nil
-- Porting note: in Batteries
#align list.nil_eq_append_iff List.nil_eq_append
@[deprecated (since := "2024-03-24")] alias append_eq_cons_iff := append_eq_cons
#align list.append_eq_cons_iff List.append_eq_cons
@[deprecated (since := "2024-03-24")] alias cons_eq_append_iff := cons_eq_append
#align list.cons_eq_append_iff List.cons_eq_append
#align list.append_eq_append_iff List.append_eq_append_iff
#align list.take_append_drop List.take_append_drop
#align list.append_inj List.append_inj
#align list.append_inj_right List.append_inj_rightₓ -- implicits order
#align list.append_inj_left List.append_inj_leftₓ -- implicits order
#align list.append_inj' List.append_inj'ₓ -- implicits order
#align list.append_inj_right' List.append_inj_right'ₓ -- implicits order
#align list.append_inj_left' List.append_inj_left'ₓ -- implicits order
@[deprecated (since := "2024-01-18")] alias append_left_cancel := append_cancel_left
#align list.append_left_cancel List.append_cancel_left
@[deprecated (since := "2024-01-18")] alias append_right_cancel := append_cancel_right
#align list.append_right_cancel List.append_cancel_right
@[simp] theorem append_left_eq_self {x y : List α} : x ++ y = y ↔ x = [] := by
rw [← append_left_inj (s₁ := x), nil_append]
@[simp] theorem self_eq_append_left {x y : List α} : y = x ++ y ↔ x = [] := by
rw [eq_comm, append_left_eq_self]
@[simp] theorem append_right_eq_self {x y : List α} : x ++ y = x ↔ y = [] := by
rw [← append_right_inj (t₁ := y), append_nil]
@[simp] theorem self_eq_append_right {x y : List α} : x = x ++ y ↔ y = [] := by
rw [eq_comm, append_right_eq_self]
theorem append_right_injective (s : List α) : Injective fun t ↦ s ++ t :=
fun _ _ ↦ append_cancel_left
#align list.append_right_injective List.append_right_injective
#align list.append_right_inj List.append_right_inj
theorem append_left_injective (t : List α) : Injective fun s ↦ s ++ t :=
fun _ _ ↦ append_cancel_right
#align list.append_left_injective List.append_left_injective
#align list.append_left_inj List.append_left_inj
#align list.map_eq_append_split List.map_eq_append_split
@[simp] lemma replicate_zero (a : α) : replicate 0 a = [] := rfl
#align list.replicate_zero List.replicate_zero
attribute [simp] replicate_succ
#align list.replicate_succ List.replicate_succ
lemma replicate_one (a : α) : replicate 1 a = [a] := rfl
#align list.replicate_one List.replicate_one
#align list.length_replicate List.length_replicate
#align list.mem_replicate List.mem_replicate
#align list.eq_of_mem_replicate List.eq_of_mem_replicate
theorem eq_replicate_length {a : α} : ∀ {l : List α}, l = replicate l.length a ↔ ∀ b ∈ l, b = a
| [] => by simp
| (b :: l) => by simp [eq_replicate_length]
#align list.eq_replicate_length List.eq_replicate_length
#align list.eq_replicate_of_mem List.eq_replicate_of_mem
#align list.eq_replicate List.eq_replicate
theorem replicate_add (m n) (a : α) : replicate (m + n) a = replicate m a ++ replicate n a := by
induction m <;> simp [*, succ_add, replicate]
#align list.replicate_add List.replicate_add
theorem replicate_succ' (n) (a : α) : replicate (n + 1) a = replicate n a ++ [a] :=
replicate_add n 1 a
#align list.replicate_succ' List.replicate_succ'
theorem replicate_subset_singleton (n) (a : α) : replicate n a ⊆ [a] := fun _ h =>
mem_singleton.2 (eq_of_mem_replicate h)
#align list.replicate_subset_singleton List.replicate_subset_singleton
theorem subset_singleton_iff {a : α} {L : List α} : L ⊆ [a] ↔ ∃ n, L = replicate n a := by
simp only [eq_replicate, subset_def, mem_singleton, exists_eq_left']
#align list.subset_singleton_iff List.subset_singleton_iff
@[simp] theorem map_replicate (f : α → β) (n) (a : α) :
map f (replicate n a) = replicate n (f a) := by
induction n <;> [rfl; simp only [*, replicate, map]]
#align list.map_replicate List.map_replicate
@[simp] theorem tail_replicate (a : α) (n) :
tail (replicate n a) = replicate (n - 1) a := by cases n <;> rfl
#align list.tail_replicate List.tail_replicate
@[simp] theorem join_replicate_nil (n : ℕ) : join (replicate n []) = @nil α := by
induction n <;> [rfl; simp only [*, replicate, join, append_nil]]
#align list.join_replicate_nil List.join_replicate_nil
theorem replicate_right_injective {n : ℕ} (hn : n ≠ 0) : Injective (@replicate α n) :=
fun _ _ h => (eq_replicate.1 h).2 _ <| mem_replicate.2 ⟨hn, rfl⟩
#align list.replicate_right_injective List.replicate_right_injective
theorem replicate_right_inj {a b : α} {n : ℕ} (hn : n ≠ 0) :
replicate n a = replicate n b ↔ a = b :=
(replicate_right_injective hn).eq_iff
#align list.replicate_right_inj List.replicate_right_inj
@[simp] theorem replicate_right_inj' {a b : α} : ∀ {n},
replicate n a = replicate n b ↔ n = 0 ∨ a = b
| 0 => by simp
| n + 1 => (replicate_right_inj n.succ_ne_zero).trans <| by simp only [n.succ_ne_zero, false_or]
#align list.replicate_right_inj' List.replicate_right_inj'
theorem replicate_left_injective (a : α) : Injective (replicate · a) :=
LeftInverse.injective (length_replicate · a)
#align list.replicate_left_injective List.replicate_left_injective
@[simp] theorem replicate_left_inj {a : α} {n m : ℕ} : replicate n a = replicate m a ↔ n = m :=
(replicate_left_injective a).eq_iff
#align list.replicate_left_inj List.replicate_left_inj
@[simp] theorem head_replicate (n : ℕ) (a : α) (h) : head (replicate n a) h = a := by
cases n <;> simp at h ⊢
theorem mem_pure (x y : α) : x ∈ (pure y : List α) ↔ x = y := by simp
#align list.mem_pure List.mem_pure
@[simp]
theorem bind_eq_bind {α β} (f : α → List β) (l : List α) : l >>= f = l.bind f :=
rfl
#align list.bind_eq_bind List.bind_eq_bind
#align list.bind_append List.append_bind
#align list.concat_nil List.concat_nil
#align list.concat_cons List.concat_cons
#align list.concat_eq_append List.concat_eq_append
#align list.init_eq_of_concat_eq List.init_eq_of_concat_eq
#align list.last_eq_of_concat_eq List.last_eq_of_concat_eq
#align list.concat_ne_nil List.concat_ne_nil
#align list.concat_append List.concat_append
#align list.length_concat List.length_concat
#align list.append_concat List.append_concat
#align list.reverse_nil List.reverse_nil
#align list.reverse_core List.reverseAux
-- Porting note: Do we need this?
attribute [local simp] reverseAux
#align list.reverse_cons List.reverse_cons
#align list.reverse_core_eq List.reverseAux_eq
theorem reverse_cons' (a : α) (l : List α) : reverse (a :: l) = concat (reverse l) a := by
simp only [reverse_cons, concat_eq_append]
#align list.reverse_cons' List.reverse_cons'
theorem reverse_concat' (l : List α) (a : α) : (l ++ [a]).reverse = a :: l.reverse := by
rw [reverse_append]; rfl
-- Porting note (#10618): simp can prove this
-- @[simp]
theorem reverse_singleton (a : α) : reverse [a] = [a] :=
rfl
#align list.reverse_singleton List.reverse_singleton
#align list.reverse_append List.reverse_append
#align list.reverse_concat List.reverse_concat
#align list.reverse_reverse List.reverse_reverse
@[simp]
theorem reverse_involutive : Involutive (@reverse α) :=
reverse_reverse
#align list.reverse_involutive List.reverse_involutive
@[simp]
theorem reverse_injective : Injective (@reverse α) :=
reverse_involutive.injective
#align list.reverse_injective List.reverse_injective
theorem reverse_surjective : Surjective (@reverse α) :=
reverse_involutive.surjective
#align list.reverse_surjective List.reverse_surjective
theorem reverse_bijective : Bijective (@reverse α) :=
reverse_involutive.bijective
#align list.reverse_bijective List.reverse_bijective
@[simp]
theorem reverse_inj {l₁ l₂ : List α} : reverse l₁ = reverse l₂ ↔ l₁ = l₂ :=
reverse_injective.eq_iff
#align list.reverse_inj List.reverse_inj
theorem reverse_eq_iff {l l' : List α} : l.reverse = l' ↔ l = l'.reverse :=
reverse_involutive.eq_iff
#align list.reverse_eq_iff List.reverse_eq_iff
#align list.reverse_eq_nil List.reverse_eq_nil_iff
theorem concat_eq_reverse_cons (a : α) (l : List α) : concat l a = reverse (a :: reverse l) := by
simp only [concat_eq_append, reverse_cons, reverse_reverse]
#align list.concat_eq_reverse_cons List.concat_eq_reverse_cons
#align list.length_reverse List.length_reverse
-- Porting note: This one was @[simp] in mathlib 3,
-- but Lean contains a competing simp lemma reverse_map.
-- For now we remove @[simp] to avoid simplification loops.
-- TODO: Change Lean lemma to match mathlib 3?
theorem map_reverse (f : α → β) (l : List α) : map f (reverse l) = reverse (map f l) :=
(reverse_map f l).symm
#align list.map_reverse List.map_reverse
theorem map_reverseAux (f : α → β) (l₁ l₂ : List α) :
map f (reverseAux l₁ l₂) = reverseAux (map f l₁) (map f l₂) := by
simp only [reverseAux_eq, map_append, map_reverse]
#align list.map_reverse_core List.map_reverseAux
#align list.mem_reverse List.mem_reverse
@[simp] theorem reverse_replicate (n) (a : α) : reverse (replicate n a) = replicate n a :=
eq_replicate.2
⟨by rw [length_reverse, length_replicate],
fun b h => eq_of_mem_replicate (mem_reverse.1 h)⟩
#align list.reverse_replicate List.reverse_replicate
-- Porting note: this does not work as desired
-- attribute [simp] List.isEmpty
theorem isEmpty_iff_eq_nil {l : List α} : l.isEmpty ↔ l = [] := by cases l <;> simp [isEmpty]
#align list.empty_iff_eq_nil List.isEmpty_iff_eq_nil
#align list.length_init List.length_dropLast
@[simp]
theorem getLast_cons {a : α} {l : List α} :
∀ h : l ≠ nil, getLast (a :: l) (cons_ne_nil a l) = getLast l h := by
induction l <;> intros
· contradiction
· rfl
#align list.last_cons List.getLast_cons
theorem getLast_append_singleton {a : α} (l : List α) :
getLast (l ++ [a]) (append_ne_nil_of_ne_nil_right l _ (cons_ne_nil a _)) = a := by
simp only [getLast_append]
#align list.last_append_singleton List.getLast_append_singleton
-- Porting note: name should be fixed upstream
theorem getLast_append' (l₁ l₂ : List α) (h : l₂ ≠ []) :
getLast (l₁ ++ l₂) (append_ne_nil_of_ne_nil_right l₁ l₂ h) = getLast l₂ h := by
induction' l₁ with _ _ ih
· simp
· simp only [cons_append]
rw [List.getLast_cons]
exact ih
#align list.last_append List.getLast_append'
theorem getLast_concat' {a : α} (l : List α) : getLast (concat l a) (concat_ne_nil a l) = a :=
getLast_concat ..
#align list.last_concat List.getLast_concat'
@[simp]
theorem getLast_singleton' (a : α) : getLast [a] (cons_ne_nil a []) = a := rfl
#align list.last_singleton List.getLast_singleton'
-- Porting note (#10618): simp can prove this
-- @[simp]
theorem getLast_cons_cons (a₁ a₂ : α) (l : List α) :
getLast (a₁ :: a₂ :: l) (cons_ne_nil _ _) = getLast (a₂ :: l) (cons_ne_nil a₂ l) :=
rfl
#align list.last_cons_cons List.getLast_cons_cons
theorem dropLast_append_getLast : ∀ {l : List α} (h : l ≠ []), dropLast l ++ [getLast l h] = l
| [], h => absurd rfl h
| [a], h => rfl
| a :: b :: l, h => by
rw [dropLast_cons₂, cons_append, getLast_cons (cons_ne_nil _ _)]
congr
exact dropLast_append_getLast (cons_ne_nil b l)
#align list.init_append_last List.dropLast_append_getLast
theorem getLast_congr {l₁ l₂ : List α} (h₁ : l₁ ≠ []) (h₂ : l₂ ≠ []) (h₃ : l₁ = l₂) :
getLast l₁ h₁ = getLast l₂ h₂ := by subst l₁; rfl
#align list.last_congr List.getLast_congr
#align list.last_mem List.getLast_mem
theorem getLast_replicate_succ (m : ℕ) (a : α) :
(replicate (m + 1) a).getLast (ne_nil_of_length_eq_succ (length_replicate _ _)) = a := by
simp only [replicate_succ']
exact getLast_append_singleton _
#align list.last_replicate_succ List.getLast_replicate_succ
-- Porting note: Moved earlier in file, for use in subsequent lemmas.
@[simp]
theorem getLast?_cons_cons (a b : α) (l : List α) :
getLast? (a :: b :: l) = getLast? (b :: l) := rfl
@[simp]
theorem getLast?_isNone : ∀ {l : List α}, (getLast? l).isNone ↔ l = []
| [] => by simp
| [a] => by simp
| a :: b :: l => by simp [@getLast?_isNone (b :: l)]
#align list.last'_is_none List.getLast?_isNone
@[simp]
theorem getLast?_isSome : ∀ {l : List α}, l.getLast?.isSome ↔ l ≠ []
| [] => by simp
| [a] => by simp
| a :: b :: l => by simp [@getLast?_isSome (b :: l)]
#align list.last'_is_some List.getLast?_isSome
theorem mem_getLast?_eq_getLast : ∀ {l : List α} {x : α}, x ∈ l.getLast? → ∃ h, x = getLast l h
| [], x, hx => False.elim <| by simp at hx
| [a], x, hx =>
have : a = x := by simpa using hx
this ▸ ⟨cons_ne_nil a [], rfl⟩
| a :: b :: l, x, hx => by
rw [getLast?_cons_cons] at hx
rcases mem_getLast?_eq_getLast hx with ⟨_, h₂⟩
use cons_ne_nil _ _
assumption
#align list.mem_last'_eq_last List.mem_getLast?_eq_getLast
theorem getLast?_eq_getLast_of_ne_nil : ∀ {l : List α} (h : l ≠ []), l.getLast? = some (l.getLast h)
| [], h => (h rfl).elim
| [_], _ => rfl
| _ :: b :: l, _ => @getLast?_eq_getLast_of_ne_nil (b :: l) (cons_ne_nil _ _)
#align list.last'_eq_last_of_ne_nil List.getLast?_eq_getLast_of_ne_nil
theorem mem_getLast?_cons {x y : α} : ∀ {l : List α}, x ∈ l.getLast? → x ∈ (y :: l).getLast?
| [], _ => by contradiction
| _ :: _, h => h
#align list.mem_last'_cons List.mem_getLast?_cons
theorem mem_of_mem_getLast? {l : List α} {a : α} (ha : a ∈ l.getLast?) : a ∈ l :=
let ⟨_, h₂⟩ := mem_getLast?_eq_getLast ha
h₂.symm ▸ getLast_mem _
#align list.mem_of_mem_last' List.mem_of_mem_getLast?
theorem dropLast_append_getLast? : ∀ {l : List α}, ∀ a ∈ l.getLast?, dropLast l ++ [a] = l
| [], a, ha => (Option.not_mem_none a ha).elim
| [a], _, rfl => rfl
| a :: b :: l, c, hc => by
rw [getLast?_cons_cons] at hc
rw [dropLast_cons₂, cons_append, dropLast_append_getLast? _ hc]
#align list.init_append_last' List.dropLast_append_getLast?
theorem getLastI_eq_getLast? [Inhabited α] : ∀ l : List α, l.getLastI = l.getLast?.iget
| [] => by simp [getLastI, Inhabited.default]
| [a] => rfl
| [a, b] => rfl
| [a, b, c] => rfl
| _ :: _ :: c :: l => by simp [getLastI, getLastI_eq_getLast? (c :: l)]
#align list.ilast_eq_last' List.getLastI_eq_getLast?
@[simp]
theorem getLast?_append_cons :
∀ (l₁ : List α) (a : α) (l₂ : List α), getLast? (l₁ ++ a :: l₂) = getLast? (a :: l₂)
| [], a, l₂ => rfl
| [b], a, l₂ => rfl
| b :: c :: l₁, a, l₂ => by rw [cons_append, cons_append, getLast?_cons_cons,
← cons_append, getLast?_append_cons (c :: l₁)]
#align list.last'_append_cons List.getLast?_append_cons
#align list.last'_cons_cons List.getLast?_cons_cons
theorem getLast?_append_of_ne_nil (l₁ : List α) :
∀ {l₂ : List α} (_ : l₂ ≠ []), getLast? (l₁ ++ l₂) = getLast? l₂
| [], hl₂ => by contradiction
| b :: l₂, _ => getLast?_append_cons l₁ b l₂
#align list.last'_append_of_ne_nil List.getLast?_append_of_ne_nil
theorem getLast?_append {l₁ l₂ : List α} {x : α} (h : x ∈ l₂.getLast?) :
x ∈ (l₁ ++ l₂).getLast? := by
cases l₂
· contradiction
· rw [List.getLast?_append_cons]
exact h
#align list.last'_append List.getLast?_append
@[simp]
theorem head!_nil [Inhabited α] : ([] : List α).head! = default := rfl
@[simp] theorem head_cons_tail (x : List α) (h : x ≠ []) : x.head h :: x.tail = x := by
cases x <;> simp at h ⊢
theorem head!_eq_head? [Inhabited α] (l : List α) : head! l = (head? l).iget := by cases l <;> rfl
#align list.head_eq_head' List.head!_eq_head?
theorem surjective_head! [Inhabited α] : Surjective (@head! α _) := fun x => ⟨[x], rfl⟩
#align list.surjective_head List.surjective_head!
theorem surjective_head? : Surjective (@head? α) :=
Option.forall.2 ⟨⟨[], rfl⟩, fun x => ⟨[x], rfl⟩⟩
#align list.surjective_head' List.surjective_head?
theorem surjective_tail : Surjective (@tail α)
| [] => ⟨[], rfl⟩
| a :: l => ⟨a :: a :: l, rfl⟩
#align list.surjective_tail List.surjective_tail
theorem eq_cons_of_mem_head? {x : α} : ∀ {l : List α}, x ∈ l.head? → l = x :: tail l
| [], h => (Option.not_mem_none _ h).elim
| a :: l, h => by
simp only [head?, Option.mem_def, Option.some_inj] at h
exact h ▸ rfl
#align list.eq_cons_of_mem_head' List.eq_cons_of_mem_head?
theorem mem_of_mem_head? {x : α} {l : List α} (h : x ∈ l.head?) : x ∈ l :=
(eq_cons_of_mem_head? h).symm ▸ mem_cons_self _ _
#align list.mem_of_mem_head' List.mem_of_mem_head?
@[simp] theorem head!_cons [Inhabited α] (a : α) (l : List α) : head! (a :: l) = a := rfl
#align list.head_cons List.head!_cons
#align list.tail_nil List.tail_nil
#align list.tail_cons List.tail_cons
@[simp]
| Mathlib/Data/List/Basic.lean | 805 | 809 | theorem head!_append [Inhabited α] (t : List α) {s : List α} (h : s ≠ []) :
head! (s ++ t) = head! s := by |
induction s
· contradiction
· rfl
|
import Mathlib.Logic.Relation
import Mathlib.Data.List.Forall2
import Mathlib.Data.List.Lex
import Mathlib.Data.List.Infix
#align_import data.list.chain from "leanprover-community/mathlib"@"dd71334db81d0bd444af1ee339a29298bef40734"
-- Make sure we haven't imported `Data.Nat.Order.Basic`
assert_not_exists OrderedSub
universe u v
open Nat
namespace List
variable {α : Type u} {β : Type v} {R r : α → α → Prop} {l l₁ l₂ : List α} {a b : α}
mk_iff_of_inductive_prop List.Chain List.chain_iff
#align list.chain_iff List.chain_iff
#align list.chain.nil List.Chain.nil
#align list.chain.cons List.Chain.cons
#align list.rel_of_chain_cons List.rel_of_chain_cons
#align list.chain_of_chain_cons List.chain_of_chain_cons
#align list.chain.imp' List.Chain.imp'
#align list.chain.imp List.Chain.imp
theorem Chain.iff {S : α → α → Prop} (H : ∀ a b, R a b ↔ S a b) {a : α} {l : List α} :
Chain R a l ↔ Chain S a l :=
⟨Chain.imp fun a b => (H a b).1, Chain.imp fun a b => (H a b).2⟩
#align list.chain.iff List.Chain.iff
theorem Chain.iff_mem {a : α} {l : List α} :
Chain R a l ↔ Chain (fun x y => x ∈ a :: l ∧ y ∈ l ∧ R x y) a l :=
⟨fun p => by
induction' p with _ a b l r _ IH <;> constructor <;>
[exact ⟨mem_cons_self _ _, mem_cons_self _ _, r⟩;
exact IH.imp fun a b ⟨am, bm, h⟩ => ⟨mem_cons_of_mem _ am, mem_cons_of_mem _ bm, h⟩],
Chain.imp fun a b h => h.2.2⟩
#align list.chain.iff_mem List.Chain.iff_mem
theorem chain_singleton {a b : α} : Chain R a [b] ↔ R a b := by
simp only [chain_cons, Chain.nil, and_true_iff]
#align list.chain_singleton List.chain_singleton
theorem chain_split {a b : α} {l₁ l₂ : List α} :
Chain R a (l₁ ++ b :: l₂) ↔ Chain R a (l₁ ++ [b]) ∧ Chain R b l₂ := by
induction' l₁ with x l₁ IH generalizing a <;>
simp only [*, nil_append, cons_append, Chain.nil, chain_cons, and_true_iff, and_assoc]
#align list.chain_split List.chain_split
@[simp]
theorem chain_append_cons_cons {a b c : α} {l₁ l₂ : List α} :
Chain R a (l₁ ++ b :: c :: l₂) ↔ Chain R a (l₁ ++ [b]) ∧ R b c ∧ Chain R c l₂ := by
rw [chain_split, chain_cons]
#align list.chain_append_cons_cons List.chain_append_cons_cons
theorem chain_iff_forall₂ :
∀ {a : α} {l : List α}, Chain R a l ↔ l = [] ∨ Forall₂ R (a :: dropLast l) l
| a, [] => by simp
| a, b :: l => by
by_cases h : l = [] <;>
simp [@chain_iff_forall₂ b l, dropLast, *]
#align list.chain_iff_forall₂ List.chain_iff_forall₂
theorem chain_append_singleton_iff_forall₂ :
Chain R a (l ++ [b]) ↔ Forall₂ R (a :: l) (l ++ [b]) := by simp [chain_iff_forall₂]
#align list.chain_append_singleton_iff_forall₂ List.chain_append_singleton_iff_forall₂
theorem chain_map (f : β → α) {b : β} {l : List β} :
Chain R (f b) (map f l) ↔ Chain (fun a b : β => R (f a) (f b)) b l := by
induction l generalizing b <;> simp only [map, Chain.nil, chain_cons, *]
#align list.chain_map List.chain_map
theorem chain_of_chain_map {S : β → β → Prop} (f : α → β) (H : ∀ a b : α, S (f a) (f b) → R a b)
{a : α} {l : List α} (p : Chain S (f a) (map f l)) : Chain R a l :=
((chain_map f).1 p).imp H
#align list.chain_of_chain_map List.chain_of_chain_map
theorem chain_map_of_chain {S : β → β → Prop} (f : α → β) (H : ∀ a b : α, R a b → S (f a) (f b))
{a : α} {l : List α} (p : Chain R a l) : Chain S (f a) (map f l) :=
(chain_map f).2 <| p.imp H
#align list.chain_map_of_chain List.chain_map_of_chain
theorem chain_pmap_of_chain {S : β → β → Prop} {p : α → Prop} {f : ∀ a, p a → β}
(H : ∀ a b ha hb, R a b → S (f a ha) (f b hb)) {a : α} {l : List α} (hl₁ : Chain R a l)
(ha : p a) (hl₂ : ∀ a ∈ l, p a) : Chain S (f a ha) (List.pmap f l hl₂) := by
induction' l with lh lt l_ih generalizing a
· simp
· simp [H _ _ _ _ (rel_of_chain_cons hl₁), l_ih (chain_of_chain_cons hl₁)]
#align list.chain_pmap_of_chain List.chain_pmap_of_chain
theorem chain_of_chain_pmap {S : β → β → Prop} {p : α → Prop} (f : ∀ a, p a → β) {l : List α}
(hl₁ : ∀ a ∈ l, p a) {a : α} (ha : p a) (hl₂ : Chain S (f a ha) (List.pmap f l hl₁))
(H : ∀ a b ha hb, S (f a ha) (f b hb) → R a b) : Chain R a l := by
induction' l with lh lt l_ih generalizing a
· simp
· simp [H _ _ _ _ (rel_of_chain_cons hl₂), l_ih _ _ (chain_of_chain_cons hl₂)]
#align list.chain_of_chain_pmap List.chain_of_chain_pmap
#align list.pairwise.chain List.Pairwise.chain
protected theorem Chain.pairwise [IsTrans α R] :
∀ {a : α} {l : List α}, Chain R a l → Pairwise R (a :: l)
| a, [], Chain.nil => pairwise_singleton _ _
| a, _, @Chain.cons _ _ _ b l h hb =>
hb.pairwise.cons
(by
simp only [mem_cons, forall_eq_or_imp, h, true_and_iff]
exact fun c hc => _root_.trans h (rel_of_pairwise_cons hb.pairwise hc))
#align list.chain.pairwise List.Chain.pairwise
theorem chain_iff_pairwise [IsTrans α R] {a : α} {l : List α} : Chain R a l ↔ Pairwise R (a :: l) :=
⟨Chain.pairwise, Pairwise.chain⟩
#align list.chain_iff_pairwise List.chain_iff_pairwise
protected theorem Chain.sublist [IsTrans α R] (hl : l₂.Chain R a) (h : l₁ <+ l₂) :
l₁.Chain R a := by
rw [chain_iff_pairwise] at hl ⊢
exact hl.sublist (h.cons_cons a)
#align list.chain.sublist List.Chain.sublist
protected theorem Chain.rel [IsTrans α R] (hl : l.Chain R a) (hb : b ∈ l) : R a b := by
rw [chain_iff_pairwise] at hl
exact rel_of_pairwise_cons hl hb
#align list.chain.rel List.Chain.rel
theorem chain_iff_get {R} : ∀ {a : α} {l : List α}, Chain R a l ↔
(∀ h : 0 < length l, R a (get l ⟨0, h⟩)) ∧
∀ (i : ℕ) (h : i < l.length - 1),
R (get l ⟨i, by omega⟩) (get l ⟨i+1, by omega⟩)
| a, [] => iff_of_true (by simp) ⟨fun h => by simp at h, fun _ h => by simp at h⟩
| a, b :: t => by
rw [chain_cons, @chain_iff_get _ _ t]
constructor
· rintro ⟨R, ⟨h0, h⟩⟩
constructor
· intro _
exact R
intro i w
cases' i with i
· apply h0
· exact h i (by simp only [length_cons] at w; omega)
rintro ⟨h0, h⟩; constructor
· apply h0
simp
constructor
· apply h 0
intro i w
exact h (i+1) (by simp only [length_cons]; omega)
set_option linter.deprecated false in
@[deprecated chain_iff_get (since := "2023-01-10")]
theorem chain_iff_nthLe {R} {a : α} {l : List α} : Chain R a l ↔
(∀ h : 0 < length l, R a (nthLe l 0 h)) ∧
∀ (i) (h : i < length l - 1),
R (nthLe l i (by omega)) (nthLe l (i + 1) (by omega)) := by
rw [chain_iff_get]; simp [nthLe]
#align list.chain_iff_nth_le List.chain_iff_nthLe
| Mathlib/Data/List/Chain.lean | 177 | 178 | theorem Chain'.imp {S : α → α → Prop} (H : ∀ a b, R a b → S a b) {l : List α} (p : Chain' R l) :
Chain' S l := by | cases l <;> [trivial; exact Chain.imp H p]
|
import Mathlib.Algebra.Group.Subgroup.MulOpposite
import Mathlib.Algebra.Group.Submonoid.Pointwise
import Mathlib.GroupTheory.GroupAction.ConjAct
#align_import group_theory.subgroup.pointwise from "leanprover-community/mathlib"@"e655e4ea5c6d02854696f97494997ba4c31be802"
open Set
open Pointwise
variable {α G A S : Type*}
@[to_additive (attr := simp, norm_cast)]
theorem inv_coe_set [InvolutiveInv G] [SetLike S G] [InvMemClass S G] {H : S} : (H : Set G)⁻¹ = H :=
Set.ext fun _ => inv_mem_iff
#align inv_coe_set inv_coe_set
#align neg_coe_set neg_coe_set
@[to_additive (attr := simp)]
lemma smul_coe_set [Group G] [SetLike S G] [SubgroupClass S G] {s : S} {a : G} (ha : a ∈ s) :
a • (s : Set G) = s := by
ext; simp [Set.mem_smul_set_iff_inv_smul_mem, mul_mem_cancel_left, ha]
@[to_additive (attr := simp)]
lemma op_smul_coe_set [Group G] [SetLike S G] [SubgroupClass S G] {s : S} {a : G} (ha : a ∈ s) :
MulOpposite.op a • (s : Set G) = s := by
ext; simp [Set.mem_smul_set_iff_inv_smul_mem, mul_mem_cancel_right, ha]
@[to_additive (attr := simp, norm_cast)]
lemma coe_mul_coe [SetLike S G] [DivInvMonoid G] [SubgroupClass S G] (H : S) :
H * H = (H : Set G) := by aesop (add simp mem_mul)
@[to_additive (attr := simp, norm_cast)]
lemma coe_div_coe [SetLike S G] [DivisionMonoid G] [SubgroupClass S G] (H : S) :
H / H = (H : Set G) := by simp [div_eq_mul_inv]
variable [Group G] [AddGroup A] {s : Set G}
namespace Subgroup
@[to_additive (attr := simp)]
theorem inv_subset_closure (S : Set G) : S⁻¹ ⊆ closure S := fun s hs => by
rw [SetLike.mem_coe, ← Subgroup.inv_mem_iff]
exact subset_closure (mem_inv.mp hs)
#align subgroup.inv_subset_closure Subgroup.inv_subset_closure
#align add_subgroup.neg_subset_closure AddSubgroup.neg_subset_closure
@[to_additive]
theorem closure_toSubmonoid (S : Set G) :
(closure S).toSubmonoid = Submonoid.closure (S ∪ S⁻¹) := by
refine le_antisymm (fun x hx => ?_) (Submonoid.closure_le.2 ?_)
· refine
closure_induction hx
(fun x hx => Submonoid.closure_mono subset_union_left (Submonoid.subset_closure hx))
(Submonoid.one_mem _) (fun x y hx hy => Submonoid.mul_mem _ hx hy) fun x hx => ?_
rwa [← Submonoid.mem_closure_inv, Set.union_inv, inv_inv, Set.union_comm]
· simp only [true_and_iff, coe_toSubmonoid, union_subset_iff, subset_closure, inv_subset_closure]
#align subgroup.closure_to_submonoid Subgroup.closure_toSubmonoid
#align add_subgroup.closure_to_add_submonoid AddSubgroup.closure_toAddSubmonoid
@[to_additive (attr := elab_as_elim)
"For additive subgroups generated by a single element, see the simpler
`zsmul_induction_left`."]
theorem closure_induction_left {p : (x : G) → x ∈ closure s → Prop} (one : p 1 (one_mem _))
(mul_left : ∀ x (hx : x ∈ s), ∀ (y) hy, p y hy → p (x * y) (mul_mem (subset_closure hx) hy))
(mul_left_inv : ∀ x (hx : x ∈ s), ∀ (y) hy, p y hy →
p (x⁻¹ * y) (mul_mem (inv_mem (subset_closure hx)) hy))
{x : G} (h : x ∈ closure s) : p x h := by
revert h
simp_rw [← mem_toSubmonoid, closure_toSubmonoid] at *
intro h
induction h using Submonoid.closure_induction_left with
| one => exact one
| mul_left x hx y hy ih =>
cases hx with
| inl hx => exact mul_left _ hx _ hy ih
| inr hx => simpa only [inv_inv] using mul_left_inv _ hx _ hy ih
#align subgroup.closure_induction_left Subgroup.closure_induction_left
#align add_subgroup.closure_induction_left AddSubgroup.closure_induction_left
@[to_additive (attr := elab_as_elim)
"For additive subgroups generated by a single element, see the simpler
`zsmul_induction_right`."]
theorem closure_induction_right {p : (x : G) → x ∈ closure s → Prop} (one : p 1 (one_mem _))
(mul_right : ∀ (x) hx, ∀ y (hy : y ∈ s), p x hx → p (x * y) (mul_mem hx (subset_closure hy)))
(mul_right_inv : ∀ (x) hx, ∀ y (hy : y ∈ s), p x hx →
p (x * y⁻¹) (mul_mem hx (inv_mem (subset_closure hy))))
{x : G} (h : x ∈ closure s) : p x h :=
closure_induction_left (s := MulOpposite.unop ⁻¹' s)
(p := fun m hm => p m.unop <| by rwa [← op_closure] at hm)
one
(fun _x hx _y hy => mul_right _ _ _ hx)
(fun _x hx _y hy => mul_right_inv _ _ _ hx)
(by rwa [← op_closure])
#align subgroup.closure_induction_right Subgroup.closure_induction_right
#align add_subgroup.closure_induction_right AddSubgroup.closure_induction_right
@[to_additive (attr := simp)]
theorem closure_inv (s : Set G) : closure s⁻¹ = closure s := by
simp only [← toSubmonoid_eq, closure_toSubmonoid, inv_inv, union_comm]
#align subgroup.closure_inv Subgroup.closure_inv
#align add_subgroup.closure_neg AddSubgroup.closure_neg
@[to_additive (attr := elab_as_elim)
"An induction principle for additive closure membership. If `p` holds for `0` and all
elements of `k` and their negation, and is preserved under addition, then `p` holds for all
elements of the additive closure of `k`."]
theorem closure_induction'' {p : (g : G) → g ∈ closure s → Prop}
(mem : ∀ x (hx : x ∈ s), p x (subset_closure hx))
(inv_mem : ∀ x (hx : x ∈ s), p x⁻¹ (inv_mem (subset_closure hx)))
(one : p 1 (one_mem _))
(mul : ∀ x y hx hy, p x hx → p y hy → p (x * y) (mul_mem hx hy))
{x} (h : x ∈ closure s) : p x h :=
closure_induction_left one (fun x hx y _ hy => mul x y _ _ (mem x hx) hy)
(fun x hx y _ => mul x⁻¹ y _ _ <| inv_mem x hx) h
#align subgroup.closure_induction'' Subgroup.closure_induction''
#align add_subgroup.closure_induction'' AddSubgroup.closure_induction''
@[to_additive (attr := elab_as_elim) " An induction principle for elements of `⨆ i, S i`.
If `C` holds for `0` and all elements of `S i` for all `i`, and is preserved under addition,
then it holds for all elements of the supremum of `S`. "]
theorem iSup_induction {ι : Sort*} (S : ι → Subgroup G) {C : G → Prop} {x : G} (hx : x ∈ ⨆ i, S i)
(mem : ∀ (i), ∀ x ∈ S i, C x) (one : C 1) (mul : ∀ x y, C x → C y → C (x * y)) : C x := by
rw [iSup_eq_closure] at hx
induction hx using closure_induction'' with
| one => exact one
| mem x hx =>
obtain ⟨i, hi⟩ := Set.mem_iUnion.mp hx
exact mem _ _ hi
| inv_mem x hx =>
obtain ⟨i, hi⟩ := Set.mem_iUnion.mp hx
exact mem _ _ (inv_mem hi)
| mul x y _ _ ihx ihy => exact mul x y ihx ihy
#align subgroup.supr_induction Subgroup.iSup_induction
#align add_subgroup.supr_induction AddSubgroup.iSup_induction
@[to_additive (attr := elab_as_elim) "A dependent version of `AddSubgroup.iSup_induction`. "]
theorem iSup_induction' {ι : Sort*} (S : ι → Subgroup G) {C : ∀ x, (x ∈ ⨆ i, S i) → Prop}
(hp : ∀ (i), ∀ x (hx : x ∈ S i), C x (mem_iSup_of_mem i hx)) (h1 : C 1 (one_mem _))
(hmul : ∀ x y hx hy, C x hx → C y hy → C (x * y) (mul_mem ‹_› ‹_›)) {x : G}
(hx : x ∈ ⨆ i, S i) : C x hx := by
suffices ∃ h, C x h from this.snd
refine iSup_induction S (C := fun x => ∃ h, C x h) hx (fun i x hx => ?_) ?_ fun x y => ?_
· exact ⟨_, hp i _ hx⟩
· exact ⟨_, h1⟩
· rintro ⟨_, Cx⟩ ⟨_, Cy⟩
exact ⟨_, hmul _ _ _ _ Cx Cy⟩
#align subgroup.supr_induction' Subgroup.iSup_induction'
#align add_subgroup.supr_induction' AddSubgroup.iSup_induction'
@[to_additive]
theorem closure_mul_le (S T : Set G) : closure (S * T) ≤ closure S ⊔ closure T :=
sInf_le fun _x ⟨_s, hs, _t, ht, hx⟩ => hx ▸
(closure S ⊔ closure T).mul_mem (SetLike.le_def.mp le_sup_left <| subset_closure hs)
(SetLike.le_def.mp le_sup_right <| subset_closure ht)
#align subgroup.closure_mul_le Subgroup.closure_mul_le
#align add_subgroup.closure_add_le AddSubgroup.closure_add_le
@[to_additive]
theorem sup_eq_closure_mul (H K : Subgroup G) : H ⊔ K = closure ((H : Set G) * (K : Set G)) :=
le_antisymm
(sup_le (fun h hh => subset_closure ⟨h, hh, 1, K.one_mem, mul_one h⟩) fun k hk =>
subset_closure ⟨1, H.one_mem, k, hk, one_mul k⟩)
((closure_mul_le _ _).trans <| by rw [closure_eq, closure_eq])
#align subgroup.sup_eq_closure Subgroup.sup_eq_closure_mul
#align add_subgroup.sup_eq_closure AddSubgroup.sup_eq_closure_add
@[to_additive]
theorem set_mul_normal_comm (s : Set G) (N : Subgroup G) [hN : N.Normal] :
s * (N : Set G) = (N : Set G) * s := by
rw [← iUnion_mul_left_image, ← iUnion_mul_right_image]
simp only [image_mul_left, image_mul_right, Set.preimage, SetLike.mem_coe, hN.mem_comm_iff]
@[to_additive "The carrier of `H ⊔ N` is just `↑H + ↑N` (pointwise set addition)
when `N` is normal."]
theorem mul_normal (H N : Subgroup G) [hN : N.Normal] : (↑(H ⊔ N) : Set G) = H * N := by
rw [sup_eq_closure_mul]
refine Set.Subset.antisymm (fun x hx => ?_) subset_closure
induction hx using closure_induction'' with
| one => exact ⟨1, one_mem _, 1, one_mem _, mul_one 1⟩
| mem _ hx => exact hx
| inv_mem x hx =>
obtain ⟨x, hx, y, hy, rfl⟩ := hx
simpa only [mul_inv_rev, mul_assoc, inv_inv, inv_mul_cancel_left]
using mul_mem_mul (inv_mem hx) (hN.conj_mem _ (inv_mem hy) x)
| mul x' x' _ _ hx hx' =>
obtain ⟨x, hx, y, hy, rfl⟩ := hx
obtain ⟨x', hx', y', hy', rfl⟩ := hx'
refine ⟨x * x', mul_mem hx hx', x'⁻¹ * y * x' * y', mul_mem ?_ hy', ?_⟩
· simpa using hN.conj_mem _ hy x'⁻¹
· simp only [mul_assoc, mul_inv_cancel_left]
#align subgroup.mul_normal Subgroup.mul_normal
#align add_subgroup.add_normal AddSubgroup.add_normal
@[to_additive "The carrier of `N ⊔ H` is just `↑N + ↑H` (pointwise set addition)
when `N` is normal."]
theorem normal_mul (N H : Subgroup G) [N.Normal] : (↑(N ⊔ H) : Set G) = N * H := by
rw [← set_mul_normal_comm, sup_comm, mul_normal]
#align subgroup.normal_mul Subgroup.normal_mul
#align add_subgroup.normal_add AddSubgroup.normal_add
@[to_additive]
| Mathlib/Algebra/Group/Subgroup/Pointwise.lean | 238 | 249 | theorem mul_inf_assoc (A B C : Subgroup G) (h : A ≤ C) :
(A : Set G) * ↑(B ⊓ C) = (A : Set G) * (B : Set G) ∩ C := by |
ext
simp only [coe_inf, Set.mem_mul, Set.mem_inter_iff]
constructor
· rintro ⟨y, hy, z, ⟨hzB, hzC⟩, rfl⟩
refine ⟨?_, mul_mem (h hy) hzC⟩
exact ⟨y, hy, z, hzB, rfl⟩
rintro ⟨⟨y, hy, z, hz, rfl⟩, hyz⟩
refine ⟨y, hy, z, ⟨hz, ?_⟩, rfl⟩
suffices y⁻¹ * (y * z) ∈ C by simpa
exact mul_mem (inv_mem (h hy)) hyz
|
import Mathlib.Order.Cover
import Mathlib.Order.Interval.Finset.Defs
#align_import data.finset.locally_finite from "leanprover-community/mathlib"@"442a83d738cb208d3600056c489be16900ba701d"
assert_not_exists MonoidWithZero
assert_not_exists Finset.sum
open Function OrderDual
open FinsetInterval
variable {ι α : Type*}
namespace Finset
section Preorder
variable [Preorder α]
section LocallyFiniteOrder
variable [LocallyFiniteOrder α] {a a₁ a₂ b b₁ b₂ c x : α}
@[simp, aesop safe apply (rule_sets := [finsetNonempty])]
theorem nonempty_Icc : (Icc a b).Nonempty ↔ a ≤ b := by
rw [← coe_nonempty, coe_Icc, Set.nonempty_Icc]
#align finset.nonempty_Icc Finset.nonempty_Icc
@[simp, aesop safe apply (rule_sets := [finsetNonempty])]
theorem nonempty_Ico : (Ico a b).Nonempty ↔ a < b := by
rw [← coe_nonempty, coe_Ico, Set.nonempty_Ico]
#align finset.nonempty_Ico Finset.nonempty_Ico
@[simp, aesop safe apply (rule_sets := [finsetNonempty])]
theorem nonempty_Ioc : (Ioc a b).Nonempty ↔ a < b := by
rw [← coe_nonempty, coe_Ioc, Set.nonempty_Ioc]
#align finset.nonempty_Ioc Finset.nonempty_Ioc
-- TODO: This is nonsense. A locally finite order is never densely ordered
@[simp]
theorem nonempty_Ioo [DenselyOrdered α] : (Ioo a b).Nonempty ↔ a < b := by
rw [← coe_nonempty, coe_Ioo, Set.nonempty_Ioo]
#align finset.nonempty_Ioo Finset.nonempty_Ioo
@[simp]
theorem Icc_eq_empty_iff : Icc a b = ∅ ↔ ¬a ≤ b := by
rw [← coe_eq_empty, coe_Icc, Set.Icc_eq_empty_iff]
#align finset.Icc_eq_empty_iff Finset.Icc_eq_empty_iff
@[simp]
theorem Ico_eq_empty_iff : Ico a b = ∅ ↔ ¬a < b := by
rw [← coe_eq_empty, coe_Ico, Set.Ico_eq_empty_iff]
#align finset.Ico_eq_empty_iff Finset.Ico_eq_empty_iff
@[simp]
theorem Ioc_eq_empty_iff : Ioc a b = ∅ ↔ ¬a < b := by
rw [← coe_eq_empty, coe_Ioc, Set.Ioc_eq_empty_iff]
#align finset.Ioc_eq_empty_iff Finset.Ioc_eq_empty_iff
-- TODO: This is nonsense. A locally finite order is never densely ordered
@[simp]
theorem Ioo_eq_empty_iff [DenselyOrdered α] : Ioo a b = ∅ ↔ ¬a < b := by
rw [← coe_eq_empty, coe_Ioo, Set.Ioo_eq_empty_iff]
#align finset.Ioo_eq_empty_iff Finset.Ioo_eq_empty_iff
alias ⟨_, Icc_eq_empty⟩ := Icc_eq_empty_iff
#align finset.Icc_eq_empty Finset.Icc_eq_empty
alias ⟨_, Ico_eq_empty⟩ := Ico_eq_empty_iff
#align finset.Ico_eq_empty Finset.Ico_eq_empty
alias ⟨_, Ioc_eq_empty⟩ := Ioc_eq_empty_iff
#align finset.Ioc_eq_empty Finset.Ioc_eq_empty
@[simp]
theorem Ioo_eq_empty (h : ¬a < b) : Ioo a b = ∅ :=
eq_empty_iff_forall_not_mem.2 fun _ hx => h ((mem_Ioo.1 hx).1.trans (mem_Ioo.1 hx).2)
#align finset.Ioo_eq_empty Finset.Ioo_eq_empty
@[simp]
theorem Icc_eq_empty_of_lt (h : b < a) : Icc a b = ∅ :=
Icc_eq_empty h.not_le
#align finset.Icc_eq_empty_of_lt Finset.Icc_eq_empty_of_lt
@[simp]
theorem Ico_eq_empty_of_le (h : b ≤ a) : Ico a b = ∅ :=
Ico_eq_empty h.not_lt
#align finset.Ico_eq_empty_of_le Finset.Ico_eq_empty_of_le
@[simp]
theorem Ioc_eq_empty_of_le (h : b ≤ a) : Ioc a b = ∅ :=
Ioc_eq_empty h.not_lt
#align finset.Ioc_eq_empty_of_le Finset.Ioc_eq_empty_of_le
@[simp]
theorem Ioo_eq_empty_of_le (h : b ≤ a) : Ioo a b = ∅ :=
Ioo_eq_empty h.not_lt
#align finset.Ioo_eq_empty_of_le Finset.Ioo_eq_empty_of_le
-- porting note (#10618): simp can prove this
-- @[simp]
theorem left_mem_Icc : a ∈ Icc a b ↔ a ≤ b := by simp only [mem_Icc, true_and_iff, le_rfl]
#align finset.left_mem_Icc Finset.left_mem_Icc
-- porting note (#10618): simp can prove this
-- @[simp]
theorem left_mem_Ico : a ∈ Ico a b ↔ a < b := by simp only [mem_Ico, true_and_iff, le_refl]
#align finset.left_mem_Ico Finset.left_mem_Ico
-- porting note (#10618): simp can prove this
-- @[simp]
theorem right_mem_Icc : b ∈ Icc a b ↔ a ≤ b := by simp only [mem_Icc, and_true_iff, le_rfl]
#align finset.right_mem_Icc Finset.right_mem_Icc
-- porting note (#10618): simp can prove this
-- @[simp]
theorem right_mem_Ioc : b ∈ Ioc a b ↔ a < b := by simp only [mem_Ioc, and_true_iff, le_rfl]
#align finset.right_mem_Ioc Finset.right_mem_Ioc
-- porting note (#10618): simp can prove this
-- @[simp]
theorem left_not_mem_Ioc : a ∉ Ioc a b := fun h => lt_irrefl _ (mem_Ioc.1 h).1
#align finset.left_not_mem_Ioc Finset.left_not_mem_Ioc
-- porting note (#10618): simp can prove this
-- @[simp]
theorem left_not_mem_Ioo : a ∉ Ioo a b := fun h => lt_irrefl _ (mem_Ioo.1 h).1
#align finset.left_not_mem_Ioo Finset.left_not_mem_Ioo
-- porting note (#10618): simp can prove this
-- @[simp]
theorem right_not_mem_Ico : b ∉ Ico a b := fun h => lt_irrefl _ (mem_Ico.1 h).2
#align finset.right_not_mem_Ico Finset.right_not_mem_Ico
-- porting note (#10618): simp can prove this
-- @[simp]
theorem right_not_mem_Ioo : b ∉ Ioo a b := fun h => lt_irrefl _ (mem_Ioo.1 h).2
#align finset.right_not_mem_Ioo Finset.right_not_mem_Ioo
theorem Icc_subset_Icc (ha : a₂ ≤ a₁) (hb : b₁ ≤ b₂) : Icc a₁ b₁ ⊆ Icc a₂ b₂ := by
simpa [← coe_subset] using Set.Icc_subset_Icc ha hb
#align finset.Icc_subset_Icc Finset.Icc_subset_Icc
theorem Ico_subset_Ico (ha : a₂ ≤ a₁) (hb : b₁ ≤ b₂) : Ico a₁ b₁ ⊆ Ico a₂ b₂ := by
simpa [← coe_subset] using Set.Ico_subset_Ico ha hb
#align finset.Ico_subset_Ico Finset.Ico_subset_Ico
theorem Ioc_subset_Ioc (ha : a₂ ≤ a₁) (hb : b₁ ≤ b₂) : Ioc a₁ b₁ ⊆ Ioc a₂ b₂ := by
simpa [← coe_subset] using Set.Ioc_subset_Ioc ha hb
#align finset.Ioc_subset_Ioc Finset.Ioc_subset_Ioc
theorem Ioo_subset_Ioo (ha : a₂ ≤ a₁) (hb : b₁ ≤ b₂) : Ioo a₁ b₁ ⊆ Ioo a₂ b₂ := by
simpa [← coe_subset] using Set.Ioo_subset_Ioo ha hb
#align finset.Ioo_subset_Ioo Finset.Ioo_subset_Ioo
theorem Icc_subset_Icc_left (h : a₁ ≤ a₂) : Icc a₂ b ⊆ Icc a₁ b :=
Icc_subset_Icc h le_rfl
#align finset.Icc_subset_Icc_left Finset.Icc_subset_Icc_left
theorem Ico_subset_Ico_left (h : a₁ ≤ a₂) : Ico a₂ b ⊆ Ico a₁ b :=
Ico_subset_Ico h le_rfl
#align finset.Ico_subset_Ico_left Finset.Ico_subset_Ico_left
theorem Ioc_subset_Ioc_left (h : a₁ ≤ a₂) : Ioc a₂ b ⊆ Ioc a₁ b :=
Ioc_subset_Ioc h le_rfl
#align finset.Ioc_subset_Ioc_left Finset.Ioc_subset_Ioc_left
theorem Ioo_subset_Ioo_left (h : a₁ ≤ a₂) : Ioo a₂ b ⊆ Ioo a₁ b :=
Ioo_subset_Ioo h le_rfl
#align finset.Ioo_subset_Ioo_left Finset.Ioo_subset_Ioo_left
theorem Icc_subset_Icc_right (h : b₁ ≤ b₂) : Icc a b₁ ⊆ Icc a b₂ :=
Icc_subset_Icc le_rfl h
#align finset.Icc_subset_Icc_right Finset.Icc_subset_Icc_right
theorem Ico_subset_Ico_right (h : b₁ ≤ b₂) : Ico a b₁ ⊆ Ico a b₂ :=
Ico_subset_Ico le_rfl h
#align finset.Ico_subset_Ico_right Finset.Ico_subset_Ico_right
theorem Ioc_subset_Ioc_right (h : b₁ ≤ b₂) : Ioc a b₁ ⊆ Ioc a b₂ :=
Ioc_subset_Ioc le_rfl h
#align finset.Ioc_subset_Ioc_right Finset.Ioc_subset_Ioc_right
theorem Ioo_subset_Ioo_right (h : b₁ ≤ b₂) : Ioo a b₁ ⊆ Ioo a b₂ :=
Ioo_subset_Ioo le_rfl h
#align finset.Ioo_subset_Ioo_right Finset.Ioo_subset_Ioo_right
theorem Ico_subset_Ioo_left (h : a₁ < a₂) : Ico a₂ b ⊆ Ioo a₁ b := by
rw [← coe_subset, coe_Ico, coe_Ioo]
exact Set.Ico_subset_Ioo_left h
#align finset.Ico_subset_Ioo_left Finset.Ico_subset_Ioo_left
theorem Ioc_subset_Ioo_right (h : b₁ < b₂) : Ioc a b₁ ⊆ Ioo a b₂ := by
rw [← coe_subset, coe_Ioc, coe_Ioo]
exact Set.Ioc_subset_Ioo_right h
#align finset.Ioc_subset_Ioo_right Finset.Ioc_subset_Ioo_right
theorem Icc_subset_Ico_right (h : b₁ < b₂) : Icc a b₁ ⊆ Ico a b₂ := by
rw [← coe_subset, coe_Icc, coe_Ico]
exact Set.Icc_subset_Ico_right h
#align finset.Icc_subset_Ico_right Finset.Icc_subset_Ico_right
theorem Ioo_subset_Ico_self : Ioo a b ⊆ Ico a b := by
rw [← coe_subset, coe_Ioo, coe_Ico]
exact Set.Ioo_subset_Ico_self
#align finset.Ioo_subset_Ico_self Finset.Ioo_subset_Ico_self
theorem Ioo_subset_Ioc_self : Ioo a b ⊆ Ioc a b := by
rw [← coe_subset, coe_Ioo, coe_Ioc]
exact Set.Ioo_subset_Ioc_self
#align finset.Ioo_subset_Ioc_self Finset.Ioo_subset_Ioc_self
theorem Ico_subset_Icc_self : Ico a b ⊆ Icc a b := by
rw [← coe_subset, coe_Ico, coe_Icc]
exact Set.Ico_subset_Icc_self
#align finset.Ico_subset_Icc_self Finset.Ico_subset_Icc_self
| Mathlib/Order/Interval/Finset/Basic.lean | 250 | 252 | theorem Ioc_subset_Icc_self : Ioc a b ⊆ Icc a b := by |
rw [← coe_subset, coe_Ioc, coe_Icc]
exact Set.Ioc_subset_Icc_self
|
import Mathlib.NumberTheory.SmoothNumbers
import Mathlib.Analysis.PSeries
open Set Nat
open scoped Topology
-- This needs `Mathlib.Analysis.RCLike.Basic`, so we put it here
-- instead of in `Mathlib.NumberTheory.SmoothNumbers`.
lemma Nat.roughNumbersUpTo_card_le' (N k : ℕ) :
(roughNumbersUpTo N k).card ≤
N * (N.succ.primesBelow \ k.primesBelow).sum (fun p ↦ (1 : ℝ) / p) := by
simp_rw [Finset.mul_sum, mul_one_div]
exact (Nat.cast_le.mpr <| roughNumbersUpTo_card_le N k).trans <|
(cast_sum (β := ℝ) ..) ▸ Finset.sum_le_sum fun n _ ↦ cast_div_le
lemma one_half_le_sum_primes_ge_one_div (k : ℕ) :
1 / 2 ≤ ∑ p ∈ (4 ^ (k.primesBelow.card + 1)).succ.primesBelow \ k.primesBelow,
(1 / p : ℝ) := by
set m : ℕ := 2 ^ k.primesBelow.card
set N₀ : ℕ := 2 * m ^ 2 with hN₀
let S : ℝ := ((2 * N₀).succ.primesBelow \ k.primesBelow).sum (fun p ↦ (1 / p : ℝ))
suffices 1 / 2 ≤ S by
convert this using 5
rw [show 4 = 2 ^ 2 by norm_num, pow_right_comm]
ring
suffices 2 * N₀ ≤ m * (2 * N₀).sqrt + 2 * N₀ * S by
rwa [hN₀, ← mul_assoc, ← pow_two 2, ← mul_pow, sqrt_eq', ← sub_le_iff_le_add',
cast_mul, cast_mul, cast_pow, cast_two,
show (2 * (2 * m ^ 2) - m * (2 * m) : ℝ) = 2 * (2 * m ^ 2) * (1 / 2) by ring,
_root_.mul_le_mul_left <| by positivity] at this
calc (2 * N₀ : ℝ)
_ = ((2 * N₀).smoothNumbersUpTo k).card + ((2 * N₀).roughNumbersUpTo k).card := by
exact_mod_cast ((2 * N₀).smoothNumbersUpTo_card_add_roughNumbersUpTo_card k).symm
_ ≤ m * (2 * N₀).sqrt + ((2 * N₀).roughNumbersUpTo k).card := by
exact_mod_cast Nat.add_le_add_right ((2 * N₀).smoothNumbersUpTo_card_le k) _
_ ≤ m * (2 * N₀).sqrt + 2 * N₀ * S := add_le_add_left ?_ _
exact_mod_cast roughNumbersUpTo_card_le' (2 * N₀) k
| Mathlib/NumberTheory/SumPrimeReciprocals.lean | 64 | 79 | theorem not_summable_one_div_on_primes :
¬ Summable (indicator {p | p.Prime} (fun n : ℕ ↦ (1 : ℝ) / n)) := by |
intro h
obtain ⟨k, hk⟩ := h.nat_tsum_vanishing (Iio_mem_nhds one_half_pos : Iio (1 / 2 : ℝ) ∈ 𝓝 0)
specialize hk ({p | Nat.Prime p} ∩ {p | k ≤ p}) inter_subset_right
rw [tsum_subtype, indicator_indicator, inter_eq_left.mpr fun n hn ↦ hn.1, mem_Iio] at hk
have h' : Summable (indicator ({p | Nat.Prime p} ∩ {p | k ≤ p}) fun n ↦ (1 : ℝ) / n) := by
convert h.indicator {n : ℕ | k ≤ n} using 1
simp only [indicator_indicator, inter_comm]
refine ((one_half_le_sum_primes_ge_one_div k).trans_lt <| LE.le.trans_lt ?_ hk).false
convert sum_le_tsum (primesBelow ((4 ^ (k.primesBelow.card + 1)).succ) \ primesBelow k)
(fun n _ ↦ indicator_nonneg (fun p _ ↦ by positivity) _) h' using 2 with p hp
obtain ⟨hp₁, hp₂⟩ := mem_setOf_eq ▸ Finset.mem_sdiff.mp hp
have hpp := prime_of_mem_primesBelow hp₁
refine (indicator_of_mem (mem_def.mpr ⟨hpp, ?_⟩) fun n : ℕ ↦ (1 / n : ℝ)).symm
exact not_lt.mp <| (not_and_or.mp <| (not_congr mem_primesBelow).mp hp₂).neg_resolve_right hpp
|
import Mathlib.SetTheory.Cardinal.Basic
import Mathlib.Tactic.Ring
#align_import data.nat.count from "leanprover-community/mathlib"@"dc6c365e751e34d100e80fe6e314c3c3e0fd2988"
open Finset
namespace Nat
variable (p : ℕ → Prop)
section Count
variable [DecidablePred p]
def count (n : ℕ) : ℕ :=
(List.range n).countP p
#align nat.count Nat.count
@[simp]
theorem count_zero : count p 0 = 0 := by
rw [count, List.range_zero, List.countP, List.countP.go]
#align nat.count_zero Nat.count_zero
def CountSet.fintype (n : ℕ) : Fintype { i // i < n ∧ p i } := by
apply Fintype.ofFinset ((Finset.range n).filter p)
intro x
rw [mem_filter, mem_range]
rfl
#align nat.count_set.fintype Nat.CountSet.fintype
scoped[Count] attribute [instance] Nat.CountSet.fintype
open Count
theorem count_eq_card_filter_range (n : ℕ) : count p n = ((range n).filter p).card := by
rw [count, List.countP_eq_length_filter]
rfl
#align nat.count_eq_card_filter_range Nat.count_eq_card_filter_range
theorem count_eq_card_fintype (n : ℕ) : count p n = Fintype.card { k : ℕ // k < n ∧ p k } := by
rw [count_eq_card_filter_range, ← Fintype.card_ofFinset, ← CountSet.fintype]
rfl
#align nat.count_eq_card_fintype Nat.count_eq_card_fintype
theorem count_succ (n : ℕ) : count p (n + 1) = count p n + if p n then 1 else 0 := by
split_ifs with h <;> simp [count, List.range_succ, h]
#align nat.count_succ Nat.count_succ
@[mono]
theorem count_monotone : Monotone (count p) :=
monotone_nat_of_le_succ fun n ↦ by by_cases h : p n <;> simp [count_succ, h]
#align nat.count_monotone Nat.count_monotone
theorem count_add (a b : ℕ) : count p (a + b) = count p a + count (fun k ↦ p (a + k)) b := by
have : Disjoint ((range a).filter p) (((range b).map <| addLeftEmbedding a).filter p) := by
apply disjoint_filter_filter
rw [Finset.disjoint_left]
simp_rw [mem_map, mem_range, addLeftEmbedding_apply]
rintro x hx ⟨c, _, rfl⟩
exact (self_le_add_right _ _).not_lt hx
simp_rw [count_eq_card_filter_range, range_add, filter_union, card_union_of_disjoint this,
filter_map, addLeftEmbedding, card_map]
rfl
#align nat.count_add Nat.count_add
theorem count_add' (a b : ℕ) : count p (a + b) = count (fun k ↦ p (k + b)) a + count p b := by
rw [add_comm, count_add, add_comm]
simp_rw [add_comm b]
#align nat.count_add' Nat.count_add'
theorem count_one : count p 1 = if p 0 then 1 else 0 := by simp [count_succ]
#align nat.count_one Nat.count_one
theorem count_succ' (n : ℕ) :
count p (n + 1) = count (fun k ↦ p (k + 1)) n + if p 0 then 1 else 0 := by
rw [count_add', count_one]
#align nat.count_succ' Nat.count_succ'
variable {p}
@[simp]
theorem count_lt_count_succ_iff {n : ℕ} : count p n < count p (n + 1) ↔ p n := by
by_cases h : p n <;> simp [count_succ, h]
#align nat.count_lt_count_succ_iff Nat.count_lt_count_succ_iff
theorem count_succ_eq_succ_count_iff {n : ℕ} : count p (n + 1) = count p n + 1 ↔ p n := by
by_cases h : p n <;> simp [h, count_succ]
#align nat.count_succ_eq_succ_count_iff Nat.count_succ_eq_succ_count_iff
theorem count_succ_eq_count_iff {n : ℕ} : count p (n + 1) = count p n ↔ ¬p n := by
by_cases h : p n <;> simp [h, count_succ]
#align nat.count_succ_eq_count_iff Nat.count_succ_eq_count_iff
alias ⟨_, count_succ_eq_succ_count⟩ := count_succ_eq_succ_count_iff
#align nat.count_succ_eq_succ_count Nat.count_succ_eq_succ_count
alias ⟨_, count_succ_eq_count⟩ := count_succ_eq_count_iff
#align nat.count_succ_eq_count Nat.count_succ_eq_count
theorem count_le_cardinal (n : ℕ) : (count p n : Cardinal) ≤ Cardinal.mk { k | p k } := by
rw [count_eq_card_fintype, ← Cardinal.mk_fintype]
exact Cardinal.mk_subtype_mono fun x hx ↦ hx.2
#align nat.count_le_cardinal Nat.count_le_cardinal
theorem lt_of_count_lt_count {a b : ℕ} (h : count p a < count p b) : a < b :=
(count_monotone p).reflect_lt h
#align nat.lt_of_count_lt_count Nat.lt_of_count_lt_count
theorem count_strict_mono {m n : ℕ} (hm : p m) (hmn : m < n) : count p m < count p n :=
(count_lt_count_succ_iff.2 hm).trans_le <| count_monotone _ (Nat.succ_le_iff.2 hmn)
#align nat.count_strict_mono Nat.count_strict_mono
theorem count_injective {m n : ℕ} (hm : p m) (hn : p n) (heq : count p m = count p n) : m = n := by
by_contra! h : m ≠ n
wlog hmn : m < n
· exact this hn hm heq.symm h.symm (h.lt_or_lt.resolve_left hmn)
· simpa [heq] using count_strict_mono hm hmn
#align nat.count_injective Nat.count_injective
theorem count_le_card (hp : (setOf p).Finite) (n : ℕ) : count p n ≤ hp.toFinset.card := by
rw [count_eq_card_filter_range]
exact Finset.card_mono fun x hx ↦ hp.mem_toFinset.2 (mem_filter.1 hx).2
#align nat.count_le_card Nat.count_le_card
theorem count_lt_card {n : ℕ} (hp : (setOf p).Finite) (hpn : p n) : count p n < hp.toFinset.card :=
(count_lt_count_succ_iff.2 hpn).trans_le (count_le_card hp _)
#align nat.count_lt_card Nat.count_lt_card
variable {q : ℕ → Prop}
variable [DecidablePred q]
| Mathlib/Data/Nat/Count.lean | 152 | 154 | theorem count_mono_left {n : ℕ} (hpq : ∀ k, p k → q k) : count p n ≤ count q n := by |
simp only [count_eq_card_filter_range]
exact card_le_card ((range n).monotone_filter_right hpq)
|
import Mathlib.Data.Set.Lattice
#align_import order.concept from "leanprover-community/mathlib"@"1e05171a5e8cf18d98d9cf7b207540acb044acae"
open Function OrderDual Set
variable {ι : Sort*} {α β γ : Type*} {κ : ι → Sort*} (r : α → β → Prop) {s s₁ s₂ : Set α}
{t t₁ t₂ : Set β}
def intentClosure (s : Set α) : Set β :=
{ b | ∀ ⦃a⦄, a ∈ s → r a b }
#align intent_closure intentClosure
def extentClosure (t : Set β) : Set α :=
{ a | ∀ ⦃b⦄, b ∈ t → r a b }
#align extent_closure extentClosure
variable {r}
theorem subset_intentClosure_iff_subset_extentClosure :
t ⊆ intentClosure r s ↔ s ⊆ extentClosure r t :=
⟨fun h _ ha _ hb => h hb ha, fun h _ hb _ ha => h ha hb⟩
#align subset_intent_closure_iff_subset_extent_closure subset_intentClosure_iff_subset_extentClosure
variable (r)
theorem gc_intentClosure_extentClosure :
GaloisConnection (toDual ∘ intentClosure r) (extentClosure r ∘ ofDual) := fun _ _ =>
subset_intentClosure_iff_subset_extentClosure
#align gc_intent_closure_extent_closure gc_intentClosure_extentClosure
theorem intentClosure_swap (t : Set β) : intentClosure (swap r) t = extentClosure r t :=
rfl
#align intent_closure_swap intentClosure_swap
theorem extentClosure_swap (s : Set α) : extentClosure (swap r) s = intentClosure r s :=
rfl
#align extent_closure_swap extentClosure_swap
@[simp]
theorem intentClosure_empty : intentClosure r ∅ = univ :=
eq_univ_of_forall fun _ _ => False.elim
#align intent_closure_empty intentClosure_empty
@[simp]
theorem extentClosure_empty : extentClosure r ∅ = univ :=
intentClosure_empty _
#align extent_closure_empty extentClosure_empty
@[simp]
theorem intentClosure_union (s₁ s₂ : Set α) :
intentClosure r (s₁ ∪ s₂) = intentClosure r s₁ ∩ intentClosure r s₂ :=
Set.ext fun _ => forall₂_or_left
#align intent_closure_union intentClosure_union
@[simp]
theorem extentClosure_union (t₁ t₂ : Set β) :
extentClosure r (t₁ ∪ t₂) = extentClosure r t₁ ∩ extentClosure r t₂ :=
intentClosure_union _ _ _
#align extent_closure_union extentClosure_union
@[simp]
theorem intentClosure_iUnion (f : ι → Set α) :
intentClosure r (⋃ i, f i) = ⋂ i, intentClosure r (f i) :=
(gc_intentClosure_extentClosure r).l_iSup
#align intent_closure_Union intentClosure_iUnion
@[simp]
theorem extentClosure_iUnion (f : ι → Set β) :
extentClosure r (⋃ i, f i) = ⋂ i, extentClosure r (f i) :=
intentClosure_iUnion _ _
#align extent_closure_Union extentClosure_iUnion
theorem intentClosure_iUnion₂ (f : ∀ i, κ i → Set α) :
intentClosure r (⋃ (i) (j), f i j) = ⋂ (i) (j), intentClosure r (f i j) :=
(gc_intentClosure_extentClosure r).l_iSup₂
#align intent_closure_Union₂ intentClosure_iUnion₂
theorem extentClosure_iUnion₂ (f : ∀ i, κ i → Set β) :
extentClosure r (⋃ (i) (j), f i j) = ⋂ (i) (j), extentClosure r (f i j) :=
intentClosure_iUnion₂ _ _
#align extent_closure_Union₂ extentClosure_iUnion₂
theorem subset_extentClosure_intentClosure (s : Set α) :
s ⊆ extentClosure r (intentClosure r s) :=
(gc_intentClosure_extentClosure r).le_u_l _
#align subset_extent_closure_intent_closure subset_extentClosure_intentClosure
theorem subset_intentClosure_extentClosure (t : Set β) :
t ⊆ intentClosure r (extentClosure r t) :=
subset_extentClosure_intentClosure _ t
#align subset_intent_closure_extent_closure subset_intentClosure_extentClosure
@[simp]
theorem intentClosure_extentClosure_intentClosure (s : Set α) :
intentClosure r (extentClosure r <| intentClosure r s) = intentClosure r s :=
(gc_intentClosure_extentClosure r).l_u_l_eq_l _
#align intent_closure_extent_closure_intent_closure intentClosure_extentClosure_intentClosure
@[simp]
theorem extentClosure_intentClosure_extentClosure (t : Set β) :
extentClosure r (intentClosure r <| extentClosure r t) = extentClosure r t :=
intentClosure_extentClosure_intentClosure _ t
#align extent_closure_intent_closure_extent_closure extentClosure_intentClosure_extentClosure
theorem intentClosure_anti : Antitone (intentClosure r) :=
(gc_intentClosure_extentClosure r).monotone_l
#align intent_closure_anti intentClosure_anti
theorem extentClosure_anti : Antitone (extentClosure r) :=
intentClosure_anti _
#align extent_closure_anti extentClosure_anti
variable (α β)
structure Concept extends Set α × Set β where
closure_fst : intentClosure r fst = snd
closure_snd : extentClosure r snd = fst
#align concept Concept
initialize_simps_projections Concept (+toProd, -fst, -snd)
namespace Concept
variable {r α β} {c d : Concept α β r}
attribute [simp] closure_fst closure_snd
@[ext]
theorem ext (h : c.fst = d.fst) : c = d := by
obtain ⟨⟨s₁, t₁⟩, h₁, _⟩ := c
obtain ⟨⟨s₂, t₂⟩, h₂, _⟩ := d
dsimp at h₁ h₂ h
substs h h₁ h₂
rfl
#align concept.ext Concept.ext
theorem ext' (h : c.snd = d.snd) : c = d := by
obtain ⟨⟨s₁, t₁⟩, _, h₁⟩ := c
obtain ⟨⟨s₂, t₂⟩, _, h₂⟩ := d
dsimp at h₁ h₂ h
substs h h₁ h₂
rfl
#align concept.ext' Concept.ext'
theorem fst_injective : Injective fun c : Concept α β r => c.fst := fun _ _ => ext
#align concept.fst_injective Concept.fst_injective
theorem snd_injective : Injective fun c : Concept α β r => c.snd := fun _ _ => ext'
#align concept.snd_injective Concept.snd_injective
instance instSupConcept : Sup (Concept α β r) :=
⟨fun c d =>
{ fst := extentClosure r (c.snd ∩ d.snd)
snd := c.snd ∩ d.snd
closure_fst := by
rw [← c.closure_fst, ← d.closure_fst, ← intentClosure_union,
intentClosure_extentClosure_intentClosure]
closure_snd := rfl }⟩
instance instInfConcept : Inf (Concept α β r) :=
⟨fun c d =>
{ fst := c.fst ∩ d.fst
snd := intentClosure r (c.fst ∩ d.fst)
closure_fst := rfl
closure_snd := by
rw [← c.closure_snd, ← d.closure_snd, ← extentClosure_union,
extentClosure_intentClosure_extentClosure] }⟩
instance instSemilatticeInfConcept : SemilatticeInf (Concept α β r) :=
(fst_injective.semilatticeInf _) fun _ _ => rfl
@[simp]
theorem fst_subset_fst_iff : c.fst ⊆ d.fst ↔ c ≤ d :=
Iff.rfl
#align concept.fst_subset_fst_iff Concept.fst_subset_fst_iff
@[simp]
theorem fst_ssubset_fst_iff : c.fst ⊂ d.fst ↔ c < d :=
Iff.rfl
#align concept.fst_ssubset_fst_iff Concept.fst_ssubset_fst_iff
@[simp]
theorem snd_subset_snd_iff : c.snd ⊆ d.snd ↔ d ≤ c := by
refine ⟨fun h => ?_, fun h => ?_⟩
· rw [← fst_subset_fst_iff, ← c.closure_snd, ← d.closure_snd]
exact extentClosure_anti _ h
· rw [← c.closure_fst, ← d.closure_fst]
exact intentClosure_anti _ h
#align concept.snd_subset_snd_iff Concept.snd_subset_snd_iff
@[simp]
| Mathlib/Order/Concept.lean | 243 | 244 | theorem snd_ssubset_snd_iff : c.snd ⊂ d.snd ↔ d < c := by |
rw [ssubset_iff_subset_not_subset, lt_iff_le_not_le, snd_subset_snd_iff, snd_subset_snd_iff]
|
import Mathlib.Algebra.Polynomial.AlgebraMap
import Mathlib.Algebra.Polynomial.Basic
import Mathlib.RingTheory.Ideal.Maps
import Mathlib.RingTheory.MvPowerSeries.Basic
#align_import ring_theory.power_series.basic from "leanprover-community/mathlib"@"2d5739b61641ee4e7e53eca5688a08f66f2e6a60"
noncomputable section
open Finset (antidiagonal mem_antidiagonal)
def PowerSeries (R : Type*) :=
MvPowerSeries Unit R
#align power_series PowerSeries
namespace PowerSeries
open Finsupp (single)
variable {R : Type*}
section
-- Porting note: not available in Lean 4
-- local reducible PowerSeries
scoped notation:9000 R "⟦X⟧" => PowerSeries R
instance [Inhabited R] : Inhabited R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [Zero R] : Zero R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [AddMonoid R] : AddMonoid R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [AddGroup R] : AddGroup R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [AddCommMonoid R] : AddCommMonoid R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [AddCommGroup R] : AddCommGroup R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [Semiring R] : Semiring R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [CommSemiring R] : CommSemiring R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [Ring R] : Ring R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [CommRing R] : CommRing R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [Nontrivial R] : Nontrivial R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance {A} [Semiring R] [AddCommMonoid A] [Module R A] : Module R A⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance {A S} [Semiring R] [Semiring S] [AddCommMonoid A] [Module R A] [Module S A] [SMul R S]
[IsScalarTower R S A] : IsScalarTower R S A⟦X⟧ :=
Pi.isScalarTower
instance {A} [Semiring A] [CommSemiring R] [Algebra R A] : Algebra R A⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
end
section Semiring
variable (R) [Semiring R]
def coeff (n : ℕ) : R⟦X⟧ →ₗ[R] R :=
MvPowerSeries.coeff R (single () n)
#align power_series.coeff PowerSeries.coeff
def monomial (n : ℕ) : R →ₗ[R] R⟦X⟧ :=
MvPowerSeries.monomial R (single () n)
#align power_series.monomial PowerSeries.monomial
variable {R}
theorem coeff_def {s : Unit →₀ ℕ} {n : ℕ} (h : s () = n) : coeff R n = MvPowerSeries.coeff R s := by
erw [coeff, ← h, ← Finsupp.unique_single s]
#align power_series.coeff_def PowerSeries.coeff_def
@[ext]
theorem ext {φ ψ : R⟦X⟧} (h : ∀ n, coeff R n φ = coeff R n ψ) : φ = ψ :=
MvPowerSeries.ext fun n => by
rw [← coeff_def]
· apply h
rfl
#align power_series.ext PowerSeries.ext
theorem ext_iff {φ ψ : R⟦X⟧} : φ = ψ ↔ ∀ n, coeff R n φ = coeff R n ψ :=
⟨fun h n => congr_arg (coeff R n) h, ext⟩
#align power_series.ext_iff PowerSeries.ext_iff
instance [Subsingleton R] : Subsingleton R⟦X⟧ := by
simp only [subsingleton_iff, ext_iff]
exact fun _ _ _ ↦ (subsingleton_iff).mp (by infer_instance) _ _
def mk {R} (f : ℕ → R) : R⟦X⟧ := fun s => f (s ())
#align power_series.mk PowerSeries.mk
@[simp]
theorem coeff_mk (n : ℕ) (f : ℕ → R) : coeff R n (mk f) = f n :=
congr_arg f Finsupp.single_eq_same
#align power_series.coeff_mk PowerSeries.coeff_mk
theorem coeff_monomial (m n : ℕ) (a : R) : coeff R m (monomial R n a) = if m = n then a else 0 :=
calc
coeff R m (monomial R n a) = _ := MvPowerSeries.coeff_monomial _ _ _
_ = if m = n then a else 0 := by simp only [Finsupp.unique_single_eq_iff]
#align power_series.coeff_monomial PowerSeries.coeff_monomial
theorem monomial_eq_mk (n : ℕ) (a : R) : monomial R n a = mk fun m => if m = n then a else 0 :=
ext fun m => by rw [coeff_monomial, coeff_mk]
#align power_series.monomial_eq_mk PowerSeries.monomial_eq_mk
@[simp]
theorem coeff_monomial_same (n : ℕ) (a : R) : coeff R n (monomial R n a) = a :=
MvPowerSeries.coeff_monomial_same _ _
#align power_series.coeff_monomial_same PowerSeries.coeff_monomial_same
@[simp]
theorem coeff_comp_monomial (n : ℕ) : (coeff R n).comp (monomial R n) = LinearMap.id :=
LinearMap.ext <| coeff_monomial_same n
#align power_series.coeff_comp_monomial PowerSeries.coeff_comp_monomial
variable (R)
def constantCoeff : R⟦X⟧ →+* R :=
MvPowerSeries.constantCoeff Unit R
#align power_series.constant_coeff PowerSeries.constantCoeff
def C : R →+* R⟦X⟧ :=
MvPowerSeries.C Unit R
set_option linter.uppercaseLean3 false in
#align power_series.C PowerSeries.C
variable {R}
def X : R⟦X⟧ :=
MvPowerSeries.X ()
set_option linter.uppercaseLean3 false in
#align power_series.X PowerSeries.X
theorem commute_X (φ : R⟦X⟧) : Commute φ X :=
MvPowerSeries.commute_X _ _
set_option linter.uppercaseLean3 false in
#align power_series.commute_X PowerSeries.commute_X
@[simp]
theorem coeff_zero_eq_constantCoeff : ⇑(coeff R 0) = constantCoeff R := by
rw [coeff, Finsupp.single_zero]
rfl
#align power_series.coeff_zero_eq_constant_coeff PowerSeries.coeff_zero_eq_constantCoeff
theorem coeff_zero_eq_constantCoeff_apply (φ : R⟦X⟧) : coeff R 0 φ = constantCoeff R φ := by
rw [coeff_zero_eq_constantCoeff]
#align power_series.coeff_zero_eq_constant_coeff_apply PowerSeries.coeff_zero_eq_constantCoeff_apply
@[simp]
theorem monomial_zero_eq_C : ⇑(monomial R 0) = C R := by
-- This used to be `rw`, but we need `erw` after leanprover/lean4#2644
erw [monomial, Finsupp.single_zero, MvPowerSeries.monomial_zero_eq_C]
set_option linter.uppercaseLean3 false in
#align power_series.monomial_zero_eq_C PowerSeries.monomial_zero_eq_C
theorem monomial_zero_eq_C_apply (a : R) : monomial R 0 a = C R a := by simp
set_option linter.uppercaseLean3 false in
#align power_series.monomial_zero_eq_C_apply PowerSeries.monomial_zero_eq_C_apply
theorem coeff_C (n : ℕ) (a : R) : coeff R n (C R a : R⟦X⟧) = if n = 0 then a else 0 := by
rw [← monomial_zero_eq_C_apply, coeff_monomial]
set_option linter.uppercaseLean3 false in
#align power_series.coeff_C PowerSeries.coeff_C
@[simp]
theorem coeff_zero_C (a : R) : coeff R 0 (C R a) = a := by
rw [coeff_C, if_pos rfl]
set_option linter.uppercaseLean3 false in
#align power_series.coeff_zero_C PowerSeries.coeff_zero_C
theorem coeff_ne_zero_C {a : R} {n : ℕ} (h : n ≠ 0) : coeff R n (C R a) = 0 := by
rw [coeff_C, if_neg h]
@[simp]
theorem coeff_succ_C {a : R} {n : ℕ} : coeff R (n + 1) (C R a) = 0 :=
coeff_ne_zero_C n.succ_ne_zero
theorem C_injective : Function.Injective (C R) := by
intro a b H
have := (ext_iff (φ := C R a) (ψ := C R b)).mp H 0
rwa [coeff_zero_C, coeff_zero_C] at this
protected theorem subsingleton_iff : Subsingleton R⟦X⟧ ↔ Subsingleton R := by
refine ⟨fun h ↦ ?_, fun _ ↦ inferInstance⟩
rw [subsingleton_iff] at h ⊢
exact fun a b ↦ C_injective (h (C R a) (C R b))
theorem X_eq : (X : R⟦X⟧) = monomial R 1 1 :=
rfl
set_option linter.uppercaseLean3 false in
#align power_series.X_eq PowerSeries.X_eq
theorem coeff_X (n : ℕ) : coeff R n (X : R⟦X⟧) = if n = 1 then 1 else 0 := by
rw [X_eq, coeff_monomial]
set_option linter.uppercaseLean3 false in
#align power_series.coeff_X PowerSeries.coeff_X
@[simp]
theorem coeff_zero_X : coeff R 0 (X : R⟦X⟧) = 0 := by
-- This used to be `rw`, but we need `erw` after leanprover/lean4#2644
erw [coeff, Finsupp.single_zero, X, MvPowerSeries.coeff_zero_X]
set_option linter.uppercaseLean3 false in
#align power_series.coeff_zero_X PowerSeries.coeff_zero_X
@[simp]
theorem coeff_one_X : coeff R 1 (X : R⟦X⟧) = 1 := by rw [coeff_X, if_pos rfl]
set_option linter.uppercaseLean3 false in
#align power_series.coeff_one_X PowerSeries.coeff_one_X
@[simp]
theorem X_ne_zero [Nontrivial R] : (X : R⟦X⟧) ≠ 0 := fun H => by
simpa only [coeff_one_X, one_ne_zero, map_zero] using congr_arg (coeff R 1) H
set_option linter.uppercaseLean3 false in
#align power_series.X_ne_zero PowerSeries.X_ne_zero
theorem X_pow_eq (n : ℕ) : (X : R⟦X⟧) ^ n = monomial R n 1 :=
MvPowerSeries.X_pow_eq _ n
set_option linter.uppercaseLean3 false in
#align power_series.X_pow_eq PowerSeries.X_pow_eq
theorem coeff_X_pow (m n : ℕ) : coeff R m ((X : R⟦X⟧) ^ n) = if m = n then 1 else 0 := by
rw [X_pow_eq, coeff_monomial]
set_option linter.uppercaseLean3 false in
#align power_series.coeff_X_pow PowerSeries.coeff_X_pow
@[simp]
| Mathlib/RingTheory/PowerSeries/Basic.lean | 316 | 317 | theorem coeff_X_pow_self (n : ℕ) : coeff R n ((X : R⟦X⟧) ^ n) = 1 := by |
rw [coeff_X_pow, if_pos rfl]
|
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
| Mathlib/Data/Set/Basic.lean | 2,204 | 2,208 | 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⟩
|
import Mathlib.MeasureTheory.Integral.IntegrableOn
import Mathlib.MeasureTheory.Integral.Bochner
import Mathlib.MeasureTheory.Function.LocallyIntegrable
import Mathlib.Topology.MetricSpace.ThickenedIndicator
import Mathlib.Topology.ContinuousFunction.Compact
import Mathlib.Analysis.NormedSpace.HahnBanach.SeparatingDual
#align_import measure_theory.integral.setIntegral from "leanprover-community/mathlib"@"24e0c85412ff6adbeca08022c25ba4876eedf37a"
assert_not_exists InnerProductSpace
noncomputable section
open Set Filter TopologicalSpace MeasureTheory Function RCLike
open scoped Classical Topology ENNReal NNReal
variable {X Y E F : Type*} [MeasurableSpace X]
namespace MeasureTheory
section NormedAddCommGroup
variable [NormedAddCommGroup E] [NormedSpace ℝ E]
{f g : X → E} {s t : Set X} {μ ν : Measure X} {l l' : Filter X}
theorem setIntegral_congr_ae₀ (hs : NullMeasurableSet s μ) (h : ∀ᵐ x ∂μ, x ∈ s → f x = g x) :
∫ x in s, f x ∂μ = ∫ x in s, g x ∂μ :=
integral_congr_ae ((ae_restrict_iff'₀ hs).2 h)
#align measure_theory.set_integral_congr_ae₀ MeasureTheory.setIntegral_congr_ae₀
@[deprecated (since := "2024-04-17")]
alias set_integral_congr_ae₀ := setIntegral_congr_ae₀
theorem setIntegral_congr_ae (hs : MeasurableSet s) (h : ∀ᵐ x ∂μ, x ∈ s → f x = g x) :
∫ x in s, f x ∂μ = ∫ x in s, g x ∂μ :=
integral_congr_ae ((ae_restrict_iff' hs).2 h)
#align measure_theory.set_integral_congr_ae MeasureTheory.setIntegral_congr_ae
@[deprecated (since := "2024-04-17")]
alias set_integral_congr_ae := setIntegral_congr_ae
theorem setIntegral_congr₀ (hs : NullMeasurableSet s μ) (h : EqOn f g s) :
∫ x in s, f x ∂μ = ∫ x in s, g x ∂μ :=
setIntegral_congr_ae₀ hs <| eventually_of_forall h
#align measure_theory.set_integral_congr₀ MeasureTheory.setIntegral_congr₀
@[deprecated (since := "2024-04-17")]
alias set_integral_congr₀ := setIntegral_congr₀
theorem setIntegral_congr (hs : MeasurableSet s) (h : EqOn f g s) :
∫ x in s, f x ∂μ = ∫ x in s, g x ∂μ :=
setIntegral_congr_ae hs <| eventually_of_forall h
#align measure_theory.set_integral_congr MeasureTheory.setIntegral_congr
@[deprecated (since := "2024-04-17")]
alias set_integral_congr := setIntegral_congr
theorem setIntegral_congr_set_ae (hst : s =ᵐ[μ] t) : ∫ x in s, f x ∂μ = ∫ x in t, f x ∂μ := by
rw [Measure.restrict_congr_set hst]
#align measure_theory.set_integral_congr_set_ae MeasureTheory.setIntegral_congr_set_ae
@[deprecated (since := "2024-04-17")]
alias set_integral_congr_set_ae := setIntegral_congr_set_ae
theorem integral_union_ae (hst : AEDisjoint μ s t) (ht : NullMeasurableSet t μ)
(hfs : IntegrableOn f s μ) (hft : IntegrableOn f t μ) :
∫ x in s ∪ t, f x ∂μ = ∫ x in s, f x ∂μ + ∫ x in t, f x ∂μ := by
simp only [IntegrableOn, Measure.restrict_union₀ hst ht, integral_add_measure hfs hft]
#align measure_theory.integral_union_ae MeasureTheory.integral_union_ae
theorem integral_union (hst : Disjoint s t) (ht : MeasurableSet t) (hfs : IntegrableOn f s μ)
(hft : IntegrableOn f t μ) : ∫ x in s ∪ t, f x ∂μ = ∫ x in s, f x ∂μ + ∫ x in t, f x ∂μ :=
integral_union_ae hst.aedisjoint ht.nullMeasurableSet hfs hft
#align measure_theory.integral_union MeasureTheory.integral_union
theorem integral_diff (ht : MeasurableSet t) (hfs : IntegrableOn f s μ) (hts : t ⊆ s) :
∫ x in s \ t, f x ∂μ = ∫ x in s, f x ∂μ - ∫ x in t, f x ∂μ := by
rw [eq_sub_iff_add_eq, ← integral_union, diff_union_of_subset hts]
exacts [disjoint_sdiff_self_left, ht, hfs.mono_set diff_subset, hfs.mono_set hts]
#align measure_theory.integral_diff MeasureTheory.integral_diff
theorem integral_inter_add_diff₀ (ht : NullMeasurableSet t μ) (hfs : IntegrableOn f s μ) :
∫ x in s ∩ t, f x ∂μ + ∫ x in s \ t, f x ∂μ = ∫ x in s, f x ∂μ := by
rw [← Measure.restrict_inter_add_diff₀ s ht, integral_add_measure]
· exact Integrable.mono_measure hfs (Measure.restrict_mono inter_subset_left le_rfl)
· exact Integrable.mono_measure hfs (Measure.restrict_mono diff_subset le_rfl)
#align measure_theory.integral_inter_add_diff₀ MeasureTheory.integral_inter_add_diff₀
theorem integral_inter_add_diff (ht : MeasurableSet t) (hfs : IntegrableOn f s μ) :
∫ x in s ∩ t, f x ∂μ + ∫ x in s \ t, f x ∂μ = ∫ x in s, f x ∂μ :=
integral_inter_add_diff₀ ht.nullMeasurableSet hfs
#align measure_theory.integral_inter_add_diff MeasureTheory.integral_inter_add_diff
theorem integral_finset_biUnion {ι : Type*} (t : Finset ι) {s : ι → Set X}
(hs : ∀ i ∈ t, MeasurableSet (s i)) (h's : Set.Pairwise (↑t) (Disjoint on s))
(hf : ∀ i ∈ t, IntegrableOn f (s i) μ) :
∫ x in ⋃ i ∈ t, s i, f x ∂μ = ∑ i ∈ t, ∫ x in s i, f x ∂μ := by
induction' t using Finset.induction_on with a t hat IH hs h's
· simp
· simp only [Finset.coe_insert, Finset.forall_mem_insert, Set.pairwise_insert,
Finset.set_biUnion_insert] at hs hf h's ⊢
rw [integral_union _ _ hf.1 (integrableOn_finset_iUnion.2 hf.2)]
· rw [Finset.sum_insert hat, IH hs.2 h's.1 hf.2]
· simp only [disjoint_iUnion_right]
exact fun i hi => (h's.2 i hi (ne_of_mem_of_not_mem hi hat).symm).1
· exact Finset.measurableSet_biUnion _ hs.2
#align measure_theory.integral_finset_bUnion MeasureTheory.integral_finset_biUnion
theorem integral_fintype_iUnion {ι : Type*} [Fintype ι] {s : ι → Set X}
(hs : ∀ i, MeasurableSet (s i)) (h's : Pairwise (Disjoint on s))
(hf : ∀ i, IntegrableOn f (s i) μ) : ∫ x in ⋃ i, s i, f x ∂μ = ∑ i, ∫ x in s i, f x ∂μ := by
convert integral_finset_biUnion Finset.univ (fun i _ => hs i) _ fun i _ => hf i
· simp
· simp [pairwise_univ, h's]
#align measure_theory.integral_fintype_Union MeasureTheory.integral_fintype_iUnion
theorem integral_empty : ∫ x in ∅, f x ∂μ = 0 := by
rw [Measure.restrict_empty, integral_zero_measure]
#align measure_theory.integral_empty MeasureTheory.integral_empty
theorem integral_univ : ∫ x in univ, f x ∂μ = ∫ x, f x ∂μ := by rw [Measure.restrict_univ]
#align measure_theory.integral_univ MeasureTheory.integral_univ
theorem integral_add_compl₀ (hs : NullMeasurableSet s μ) (hfi : Integrable f μ) :
∫ x in s, f x ∂μ + ∫ x in sᶜ, f x ∂μ = ∫ x, f x ∂μ := by
rw [
← integral_union_ae disjoint_compl_right.aedisjoint hs.compl hfi.integrableOn hfi.integrableOn,
union_compl_self, integral_univ]
#align measure_theory.integral_add_compl₀ MeasureTheory.integral_add_compl₀
theorem integral_add_compl (hs : MeasurableSet s) (hfi : Integrable f μ) :
∫ x in s, f x ∂μ + ∫ x in sᶜ, f x ∂μ = ∫ x, f x ∂μ :=
integral_add_compl₀ hs.nullMeasurableSet hfi
#align measure_theory.integral_add_compl MeasureTheory.integral_add_compl
| Mathlib/MeasureTheory/Integral/SetIntegral.lean | 183 | 194 | theorem integral_indicator (hs : MeasurableSet s) :
∫ x, indicator s f x ∂μ = ∫ x in s, f x ∂μ := by |
by_cases hfi : IntegrableOn f s μ; swap
· rw [integral_undef hfi, integral_undef]
rwa [integrable_indicator_iff hs]
calc
∫ x, indicator s f x ∂μ = ∫ x in s, indicator s f x ∂μ + ∫ x in sᶜ, indicator s f x ∂μ :=
(integral_add_compl hs (hfi.integrable_indicator hs)).symm
_ = ∫ x in s, f x ∂μ + ∫ x in sᶜ, 0 ∂μ :=
(congr_arg₂ (· + ·) (integral_congr_ae (indicator_ae_eq_restrict hs))
(integral_congr_ae (indicator_ae_eq_restrict_compl hs)))
_ = ∫ x in s, f x ∂μ := by simp
|
import Mathlib.Analysis.Normed.Group.Quotient
import Mathlib.Topology.Instances.AddCircle
#align_import analysis.normed.group.add_circle from "leanprover-community/mathlib"@"084f76e20c88eae536222583331abd9468b08e1c"
noncomputable section
open Set
open Int hiding mem_zmultiples_iff
open AddSubgroup
namespace AddCircle
variable (p : ℝ)
instance : NormedAddCommGroup (AddCircle p) :=
AddSubgroup.normedAddCommGroupQuotient _
@[simp]
theorem norm_coe_mul (x : ℝ) (t : ℝ) :
‖(↑(t * x) : AddCircle (t * p))‖ = |t| * ‖(x : AddCircle p)‖ := by
have aux : ∀ {a b c : ℝ}, a ∈ zmultiples b → c * a ∈ zmultiples (c * b) := fun {a b c} h => by
simp only [mem_zmultiples_iff] at h ⊢
obtain ⟨n, rfl⟩ := h
exact ⟨n, (mul_smul_comm n c b).symm⟩
rcases eq_or_ne t 0 with (rfl | ht); · simp
have ht' : |t| ≠ 0 := (not_congr abs_eq_zero).mpr ht
simp only [quotient_norm_eq, Real.norm_eq_abs]
conv_rhs => rw [← smul_eq_mul, ← Real.sInf_smul_of_nonneg (abs_nonneg t)]
simp only [QuotientAddGroup.mk'_apply, QuotientAddGroup.eq_iff_sub_mem]
congr 1
ext z
rw [mem_smul_set_iff_inv_smul_mem₀ ht']
show
(∃ y, y - t * x ∈ zmultiples (t * p) ∧ |y| = z) ↔ ∃ w, w - x ∈ zmultiples p ∧ |w| = |t|⁻¹ * z
constructor
· rintro ⟨y, hy, rfl⟩
refine ⟨t⁻¹ * y, ?_, by rw [abs_mul, abs_inv]⟩
rw [← inv_mul_cancel_left₀ ht x, ← inv_mul_cancel_left₀ ht p, ← mul_sub]
exact aux hy
· rintro ⟨w, hw, hw'⟩
refine ⟨t * w, ?_, by rw [← (eq_inv_mul_iff_mul_eq₀ ht').mp hw', abs_mul]⟩
rw [← mul_sub]
exact aux hw
#align add_circle.norm_coe_mul AddCircle.norm_coe_mul
theorem norm_neg_period (x : ℝ) : ‖(x : AddCircle (-p))‖ = ‖(x : AddCircle p)‖ := by
suffices ‖(↑(-1 * x) : AddCircle (-1 * p))‖ = ‖(x : AddCircle p)‖ by
rw [← this, neg_one_mul]
simp
simp only [norm_coe_mul, abs_neg, abs_one, one_mul]
#align add_circle.norm_neg_period AddCircle.norm_neg_period
@[simp]
| Mathlib/Analysis/Normed/Group/AddCircle.lean | 79 | 83 | theorem norm_eq_of_zero {x : ℝ} : ‖(x : AddCircle (0 : ℝ))‖ = |x| := by |
suffices { y : ℝ | (y : AddCircle (0 : ℝ)) = (x : AddCircle (0 : ℝ)) } = {x} by
rw [quotient_norm_eq, this, image_singleton, Real.norm_eq_abs, csInf_singleton]
ext y
simp [QuotientAddGroup.eq_iff_sub_mem, mem_zmultiples_iff, sub_eq_zero]
|
import Mathlib.Algebra.Order.Floor
import Mathlib.Algebra.Order.Field.Power
import Mathlib.Data.Nat.Log
#align_import data.int.log from "leanprover-community/mathlib"@"1f0096e6caa61e9c849ec2adbd227e960e9dff58"
variable {R : Type*} [LinearOrderedSemifield R] [FloorSemiring R]
namespace Int
def log (b : ℕ) (r : R) : ℤ :=
if 1 ≤ r then Nat.log b ⌊r⌋₊ else -Nat.clog b ⌈r⁻¹⌉₊
#align int.log Int.log
theorem log_of_one_le_right (b : ℕ) {r : R} (hr : 1 ≤ r) : log b r = Nat.log b ⌊r⌋₊ :=
if_pos hr
#align int.log_of_one_le_right Int.log_of_one_le_right
theorem log_of_right_le_one (b : ℕ) {r : R} (hr : r ≤ 1) : log b r = -Nat.clog b ⌈r⁻¹⌉₊ := by
obtain rfl | hr := hr.eq_or_lt
· rw [log, if_pos hr, inv_one, Nat.ceil_one, Nat.floor_one, Nat.log_one_right, Nat.clog_one_right,
Int.ofNat_zero, neg_zero]
· exact if_neg hr.not_le
#align int.log_of_right_le_one Int.log_of_right_le_one
@[simp, norm_cast]
theorem log_natCast (b : ℕ) (n : ℕ) : log b (n : R) = Nat.log b n := by
cases n
· simp [log_of_right_le_one]
· rw [log_of_one_le_right, Nat.floor_natCast]
simp
#align int.log_nat_cast Int.log_natCast
-- See note [no_index around OfNat.ofNat]
@[simp]
theorem log_ofNat (b : ℕ) (n : ℕ) [n.AtLeastTwo] :
log b (no_index (OfNat.ofNat n : R)) = Nat.log b (OfNat.ofNat n) :=
log_natCast b n
theorem log_of_left_le_one {b : ℕ} (hb : b ≤ 1) (r : R) : log b r = 0 := by
rcases le_total 1 r with h | h
· rw [log_of_one_le_right _ h, Nat.log_of_left_le_one hb, Int.ofNat_zero]
· rw [log_of_right_le_one _ h, Nat.clog_of_left_le_one hb, Int.ofNat_zero, neg_zero]
#align int.log_of_left_le_one Int.log_of_left_le_one
theorem log_of_right_le_zero (b : ℕ) {r : R} (hr : r ≤ 0) : log b r = 0 := by
rw [log_of_right_le_one _ (hr.trans zero_le_one),
Nat.clog_of_right_le_one ((Nat.ceil_eq_zero.mpr <| inv_nonpos.2 hr).trans_le zero_le_one),
Int.ofNat_zero, neg_zero]
#align int.log_of_right_le_zero Int.log_of_right_le_zero
theorem zpow_log_le_self {b : ℕ} {r : R} (hb : 1 < b) (hr : 0 < r) : (b : R) ^ log b r ≤ r := by
rcases le_total 1 r with hr1 | hr1
· rw [log_of_one_le_right _ hr1]
rw [zpow_natCast, ← Nat.cast_pow, ← Nat.le_floor_iff hr.le]
exact Nat.pow_log_le_self b (Nat.floor_pos.mpr hr1).ne'
· rw [log_of_right_le_one _ hr1, zpow_neg, zpow_natCast, ← Nat.cast_pow]
exact inv_le_of_inv_le hr (Nat.ceil_le.1 <| Nat.le_pow_clog hb _)
#align int.zpow_log_le_self Int.zpow_log_le_self
theorem lt_zpow_succ_log_self {b : ℕ} (hb : 1 < b) (r : R) : r < (b : R) ^ (log b r + 1) := by
rcases le_or_lt r 0 with hr | hr
· rw [log_of_right_le_zero _ hr, zero_add, zpow_one]
exact hr.trans_lt (zero_lt_one.trans_le <| mod_cast hb.le)
rcases le_or_lt 1 r with hr1 | hr1
· rw [log_of_one_le_right _ hr1]
rw [Int.ofNat_add_one_out, zpow_natCast, ← Nat.cast_pow]
apply Nat.lt_of_floor_lt
exact Nat.lt_pow_succ_log_self hb _
· rw [log_of_right_le_one _ hr1.le]
have hcri : 1 < r⁻¹ := one_lt_inv hr hr1
have : 1 ≤ Nat.clog b ⌈r⁻¹⌉₊ :=
Nat.succ_le_of_lt (Nat.clog_pos hb <| Nat.one_lt_cast.1 <| hcri.trans_le (Nat.le_ceil _))
rw [neg_add_eq_sub, ← neg_sub, ← Int.ofNat_one, ← Int.ofNat_sub this, zpow_neg, zpow_natCast,
lt_inv hr (pow_pos (Nat.cast_pos.mpr <| zero_lt_one.trans hb) _), ← Nat.cast_pow]
refine Nat.lt_ceil.1 ?_
exact Nat.pow_pred_clog_lt_self hb <| Nat.one_lt_cast.1 <| hcri.trans_le <| Nat.le_ceil _
#align int.lt_zpow_succ_log_self Int.lt_zpow_succ_log_self
@[simp]
theorem log_zero_right (b : ℕ) : log b (0 : R) = 0 :=
log_of_right_le_zero b le_rfl
#align int.log_zero_right Int.log_zero_right
@[simp]
theorem log_one_right (b : ℕ) : log b (1 : R) = 0 := by
rw [log_of_one_le_right _ le_rfl, Nat.floor_one, Nat.log_one_right, Int.ofNat_zero]
#align int.log_one_right Int.log_one_right
-- Porting note: needed to replace b ^ z with (b : R) ^ z in the below
theorem log_zpow {b : ℕ} (hb : 1 < b) (z : ℤ) : log b ((b : R) ^ z : R) = z := by
obtain ⟨n, rfl | rfl⟩ := Int.eq_nat_or_neg z
· rw [log_of_one_le_right _ (one_le_zpow_of_nonneg _ <| Int.natCast_nonneg _), zpow_natCast, ←
Nat.cast_pow, Nat.floor_natCast, Nat.log_pow hb]
exact mod_cast hb.le
· rw [log_of_right_le_one _ (zpow_le_one_of_nonpos _ <| neg_nonpos.mpr (Int.natCast_nonneg _)),
zpow_neg, inv_inv, zpow_natCast, ← Nat.cast_pow, Nat.ceil_natCast, Nat.clog_pow _ _ hb]
exact mod_cast hb.le
#align int.log_zpow Int.log_zpow
@[mono]
theorem log_mono_right {b : ℕ} {r₁ r₂ : R} (h₀ : 0 < r₁) (h : r₁ ≤ r₂) : log b r₁ ≤ log b r₂ := by
rcases le_total r₁ 1 with h₁ | h₁ <;> rcases le_total r₂ 1 with h₂ | h₂
· rw [log_of_right_le_one _ h₁, log_of_right_le_one _ h₂, neg_le_neg_iff, Int.ofNat_le]
exact Nat.clog_mono_right _ (Nat.ceil_mono <| inv_le_inv_of_le h₀ h)
· rw [log_of_right_le_one _ h₁, log_of_one_le_right _ h₂]
exact (neg_nonpos.mpr (Int.natCast_nonneg _)).trans (Int.natCast_nonneg _)
· obtain rfl := le_antisymm h (h₂.trans h₁)
rfl
· rw [log_of_one_le_right _ h₁, log_of_one_le_right _ h₂, Int.ofNat_le]
exact Nat.log_mono_right (Nat.floor_mono h)
#align int.log_mono_right Int.log_mono_right
variable (R)
def zpowLogGi {b : ℕ} (hb : 1 < b) :
GaloisCoinsertion
(fun z : ℤ =>
Subtype.mk ((b : R) ^ z) <| zpow_pos_of_pos (mod_cast zero_lt_one.trans hb) z)
fun r : Set.Ioi (0 : R) => Int.log b (r : R) :=
GaloisCoinsertion.monotoneIntro (fun r₁ _ => log_mono_right r₁.2)
(fun _ _ hz => Subtype.coe_le_coe.mp <| (zpow_strictMono <| mod_cast hb).monotone hz)
(fun r => Subtype.coe_le_coe.mp <| zpow_log_le_self hb r.2) fun _ => log_zpow (R := R) hb _
#align int.zpow_log_gi Int.zpowLogGi
variable {R}
theorem lt_zpow_iff_log_lt {b : ℕ} (hb : 1 < b) {x : ℤ} {r : R} (hr : 0 < r) :
r < (b : R) ^ x ↔ log b r < x :=
@GaloisConnection.lt_iff_lt _ _ _ _ _ _ (zpowLogGi R hb).gc x ⟨r, hr⟩
#align int.lt_zpow_iff_log_lt Int.lt_zpow_iff_log_lt
theorem zpow_le_iff_le_log {b : ℕ} (hb : 1 < b) {x : ℤ} {r : R} (hr : 0 < r) :
(b : R) ^ x ≤ r ↔ x ≤ log b r :=
@GaloisConnection.le_iff_le _ _ _ _ _ _ (zpowLogGi R hb).gc x ⟨r, hr⟩
#align int.zpow_le_iff_le_log Int.zpow_le_iff_le_log
def clog (b : ℕ) (r : R) : ℤ :=
if 1 ≤ r then Nat.clog b ⌈r⌉₊ else -Nat.log b ⌊r⁻¹⌋₊
#align int.clog Int.clog
theorem clog_of_one_le_right (b : ℕ) {r : R} (hr : 1 ≤ r) : clog b r = Nat.clog b ⌈r⌉₊ :=
if_pos hr
#align int.clog_of_one_le_right Int.clog_of_one_le_right
| Mathlib/Data/Int/Log.lean | 197 | 201 | theorem clog_of_right_le_one (b : ℕ) {r : R} (hr : r ≤ 1) : clog b r = -Nat.log b ⌊r⁻¹⌋₊ := by |
obtain rfl | hr := hr.eq_or_lt
· rw [clog, if_pos hr, inv_one, Nat.ceil_one, Nat.floor_one, Nat.log_one_right,
Nat.clog_one_right, Int.ofNat_zero, neg_zero]
· exact if_neg hr.not_le
|
import Mathlib.Data.Finsupp.Encodable
import Mathlib.LinearAlgebra.Pi
import Mathlib.LinearAlgebra.Span
import Mathlib.Data.Set.Countable
#align_import linear_algebra.finsupp from "leanprover-community/mathlib"@"9d684a893c52e1d6692a504a118bfccbae04feeb"
noncomputable section
open Set LinearMap Submodule
namespace Finsupp
variable {α : Type*} {M : Type*} {N : Type*} {P : Type*} {R : Type*} {S : Type*}
variable [Semiring R] [Semiring S] [AddCommMonoid M] [Module R M]
variable [AddCommMonoid N] [Module R N]
variable [AddCommMonoid P] [Module R P]
def lsingle (a : α) : M →ₗ[R] α →₀ M :=
{ Finsupp.singleAddHom a with map_smul' := fun _ _ => (smul_single _ _ _).symm }
#align finsupp.lsingle Finsupp.lsingle
theorem lhom_ext ⦃φ ψ : (α →₀ M) →ₗ[R] N⦄ (h : ∀ a b, φ (single a b) = ψ (single a b)) : φ = ψ :=
LinearMap.toAddMonoidHom_injective <| addHom_ext h
#align finsupp.lhom_ext Finsupp.lhom_ext
-- Porting note: The priority should be higher than `LinearMap.ext`.
@[ext high]
theorem lhom_ext' ⦃φ ψ : (α →₀ M) →ₗ[R] N⦄ (h : ∀ a, φ.comp (lsingle a) = ψ.comp (lsingle a)) :
φ = ψ :=
lhom_ext fun a => LinearMap.congr_fun (h a)
#align finsupp.lhom_ext' Finsupp.lhom_ext'
def lapply (a : α) : (α →₀ M) →ₗ[R] M :=
{ Finsupp.applyAddHom a with map_smul' := fun _ _ => rfl }
#align finsupp.lapply Finsupp.lapply
@[simps]
def lcoeFun : (α →₀ M) →ₗ[R] α → M where
toFun := (⇑)
map_add' x y := by
ext
simp
map_smul' x y := by
ext
simp
#align finsupp.lcoe_fun Finsupp.lcoeFun
@[simp]
theorem lsingle_apply (a : α) (b : M) : (lsingle a : M →ₗ[R] α →₀ M) b = single a b :=
rfl
#align finsupp.lsingle_apply Finsupp.lsingle_apply
@[simp]
theorem lapply_apply (a : α) (f : α →₀ M) : (lapply a : (α →₀ M) →ₗ[R] M) f = f a :=
rfl
#align finsupp.lapply_apply Finsupp.lapply_apply
@[simp]
theorem lapply_comp_lsingle_same (a : α) : lapply a ∘ₗ lsingle a = (.id : M →ₗ[R] M) := by ext; simp
@[simp]
theorem lapply_comp_lsingle_of_ne (a a' : α) (h : a ≠ a') :
lapply a ∘ₗ lsingle a' = (0 : M →ₗ[R] M) := by ext; simp [h.symm]
@[simp]
theorem ker_lsingle (a : α) : ker (lsingle a : M →ₗ[R] α →₀ M) = ⊥ :=
ker_eq_bot_of_injective (single_injective a)
#align finsupp.ker_lsingle Finsupp.ker_lsingle
theorem lsingle_range_le_ker_lapply (s t : Set α) (h : Disjoint s t) :
⨆ a ∈ s, LinearMap.range (lsingle a : M →ₗ[R] α →₀ M) ≤
⨅ a ∈ t, ker (lapply a : (α →₀ M) →ₗ[R] M) := by
refine iSup_le fun a₁ => iSup_le fun h₁ => range_le_iff_comap.2 ?_
simp only [(ker_comp _ _).symm, eq_top_iff, SetLike.le_def, mem_ker, comap_iInf, mem_iInf]
intro b _ a₂ h₂
have : a₁ ≠ a₂ := fun eq => h.le_bot ⟨h₁, eq.symm ▸ h₂⟩
exact single_eq_of_ne this
#align finsupp.lsingle_range_le_ker_lapply Finsupp.lsingle_range_le_ker_lapply
theorem iInf_ker_lapply_le_bot : ⨅ a, ker (lapply a : (α →₀ M) →ₗ[R] M) ≤ ⊥ := by
simp only [SetLike.le_def, mem_iInf, mem_ker, mem_bot, lapply_apply]
exact fun a h => Finsupp.ext h
#align finsupp.infi_ker_lapply_le_bot Finsupp.iInf_ker_lapply_le_bot
theorem iSup_lsingle_range : ⨆ a, LinearMap.range (lsingle a : M →ₗ[R] α →₀ M) = ⊤ := by
refine eq_top_iff.2 <| SetLike.le_def.2 fun f _ => ?_
rw [← sum_single f]
exact sum_mem fun a _ => Submodule.mem_iSup_of_mem a ⟨_, rfl⟩
#align finsupp.supr_lsingle_range Finsupp.iSup_lsingle_range
| Mathlib/LinearAlgebra/Finsupp.lean | 266 | 284 | theorem disjoint_lsingle_lsingle (s t : Set α) (hs : Disjoint s t) :
Disjoint (⨆ a ∈ s, LinearMap.range (lsingle a : M →ₗ[R] α →₀ M))
(⨆ a ∈ t, LinearMap.range (lsingle a : M →ₗ[R] α →₀ M)) := by |
-- Porting note: 2 placeholders are added to prevent timeout.
refine
(Disjoint.mono
(lsingle_range_le_ker_lapply s sᶜ ?_)
(lsingle_range_le_ker_lapply t tᶜ ?_))
?_
· apply disjoint_compl_right
· apply disjoint_compl_right
rw [disjoint_iff_inf_le]
refine le_trans (le_iInf fun i => ?_) iInf_ker_lapply_le_bot
classical
by_cases his : i ∈ s
· by_cases hit : i ∈ t
· exact (hs.le_bot ⟨his, hit⟩).elim
exact inf_le_of_right_le (iInf_le_of_le i <| iInf_le _ hit)
exact inf_le_of_left_le (iInf_le_of_le i <| iInf_le _ his)
|
import Mathlib.FieldTheory.RatFunc.Defs
import Mathlib.RingTheory.EuclideanDomain
import Mathlib.RingTheory.Localization.FractionRing
import Mathlib.RingTheory.Polynomial.Content
#align_import field_theory.ratfunc from "leanprover-community/mathlib"@"bf9bbbcf0c1c1ead18280b0d010e417b10abb1b6"
universe u v
noncomputable section
open scoped Classical
open scoped nonZeroDivisors Polynomial
variable {K : Type u}
namespace RatFunc
section Field
variable [CommRing K]
protected irreducible_def zero : RatFunc K :=
⟨0⟩
#align ratfunc.zero RatFunc.zero
instance : Zero (RatFunc K) :=
⟨RatFunc.zero⟩
-- Porting note: added `OfNat.ofNat`. using `simp?` produces `simp only [zero_def]`
-- that does not close the goal
theorem ofFractionRing_zero : (ofFractionRing 0 : RatFunc K) = 0 := by
simp only [Zero.zero, OfNat.ofNat, RatFunc.zero]
#align ratfunc.of_fraction_ring_zero RatFunc.ofFractionRing_zero
protected irreducible_def add : RatFunc K → RatFunc K → RatFunc K
| ⟨p⟩, ⟨q⟩ => ⟨p + q⟩
#align ratfunc.add RatFunc.add
instance : Add (RatFunc K) :=
⟨RatFunc.add⟩
-- Porting note: added `HAdd.hAdd`. using `simp?` produces `simp only [add_def]`
-- that does not close the goal
theorem ofFractionRing_add (p q : FractionRing K[X]) :
ofFractionRing (p + q) = ofFractionRing p + ofFractionRing q := by
simp only [HAdd.hAdd, Add.add, RatFunc.add]
#align ratfunc.of_fraction_ring_add RatFunc.ofFractionRing_add
protected irreducible_def sub : RatFunc K → RatFunc K → RatFunc K
| ⟨p⟩, ⟨q⟩ => ⟨p - q⟩
#align ratfunc.sub RatFunc.sub
instance : Sub (RatFunc K) :=
⟨RatFunc.sub⟩
-- Porting note: added `HSub.hSub`. using `simp?` produces `simp only [sub_def]`
-- that does not close the goal
theorem ofFractionRing_sub (p q : FractionRing K[X]) :
ofFractionRing (p - q) = ofFractionRing p - ofFractionRing q := by
simp only [Sub.sub, HSub.hSub, RatFunc.sub]
#align ratfunc.of_fraction_ring_sub RatFunc.ofFractionRing_sub
protected irreducible_def neg : RatFunc K → RatFunc K
| ⟨p⟩ => ⟨-p⟩
#align ratfunc.neg RatFunc.neg
instance : Neg (RatFunc K) :=
⟨RatFunc.neg⟩
theorem ofFractionRing_neg (p : FractionRing K[X]) :
ofFractionRing (-p) = -ofFractionRing p := by simp only [Neg.neg, RatFunc.neg]
#align ratfunc.of_fraction_ring_neg RatFunc.ofFractionRing_neg
protected irreducible_def one : RatFunc K :=
⟨1⟩
#align ratfunc.one RatFunc.one
instance : One (RatFunc K) :=
⟨RatFunc.one⟩
-- Porting note: added `OfNat.ofNat`. using `simp?` produces `simp only [one_def]`
-- that does not close the goal
theorem ofFractionRing_one : (ofFractionRing 1 : RatFunc K) = 1 := by
simp only [One.one, OfNat.ofNat, RatFunc.one]
#align ratfunc.of_fraction_ring_one RatFunc.ofFractionRing_one
protected irreducible_def mul : RatFunc K → RatFunc K → RatFunc K
| ⟨p⟩, ⟨q⟩ => ⟨p * q⟩
#align ratfunc.mul RatFunc.mul
instance : Mul (RatFunc K) :=
⟨RatFunc.mul⟩
-- Porting note: added `HMul.hMul`. using `simp?` produces `simp only [mul_def]`
-- that does not close the goal
theorem ofFractionRing_mul (p q : FractionRing K[X]) :
ofFractionRing (p * q) = ofFractionRing p * ofFractionRing q := by
simp only [Mul.mul, HMul.hMul, RatFunc.mul]
#align ratfunc.of_fraction_ring_mul RatFunc.ofFractionRing_mul
section SMul
variable {R : Type*}
protected irreducible_def smul [SMul R (FractionRing K[X])] : R → RatFunc K → RatFunc K
| r, ⟨p⟩ => ⟨r • p⟩
#align ratfunc.smul RatFunc.smul
-- cannot reproduce
--@[nolint fails_quickly] -- Porting note: `linter 'fails_quickly' not found`
instance [SMul R (FractionRing K[X])] : SMul R (RatFunc K) :=
⟨RatFunc.smul⟩
-- Porting note: added `SMul.hSMul`. using `simp?` produces `simp only [smul_def]`
-- that does not close the goal
theorem ofFractionRing_smul [SMul R (FractionRing K[X])] (c : R) (p : FractionRing K[X]) :
ofFractionRing (c • p) = c • ofFractionRing p := by
simp only [SMul.smul, HSMul.hSMul, RatFunc.smul]
#align ratfunc.of_fraction_ring_smul RatFunc.ofFractionRing_smul
| Mathlib/FieldTheory/RatFunc/Basic.lean | 214 | 217 | theorem toFractionRing_smul [SMul R (FractionRing K[X])] (c : R) (p : RatFunc K) :
toFractionRing (c • p) = c • toFractionRing p := by |
cases p
rw [← ofFractionRing_smul]
|
import Mathlib.Init.Function
#align_import data.option.n_ary from "leanprover-community/mathlib"@"995b47e555f1b6297c7cf16855f1023e355219fb"
universe u
open Function
namespace Option
variable {α β γ δ : Type*} {f : α → β → γ} {a : Option α} {b : Option β} {c : Option γ}
def map₂ (f : α → β → γ) (a : Option α) (b : Option β) : Option γ :=
a.bind fun a => b.map <| f a
#align option.map₂ Option.map₂
theorem map₂_def {α β γ : Type u} (f : α → β → γ) (a : Option α) (b : Option β) :
map₂ f a b = f <$> a <*> b := by
cases a <;> rfl
#align option.map₂_def Option.map₂_def
-- Porting note (#10618): In Lean3, was `@[simp]` but now `simp` can prove it
theorem map₂_some_some (f : α → β → γ) (a : α) (b : β) : map₂ f (some a) (some b) = f a b := rfl
#align option.map₂_some_some Option.map₂_some_some
theorem map₂_coe_coe (f : α → β → γ) (a : α) (b : β) : map₂ f a b = f a b := rfl
#align option.map₂_coe_coe Option.map₂_coe_coe
@[simp]
theorem map₂_none_left (f : α → β → γ) (b : Option β) : map₂ f none b = none := rfl
#align option.map₂_none_left Option.map₂_none_left
@[simp]
theorem map₂_none_right (f : α → β → γ) (a : Option α) : map₂ f a none = none := by cases a <;> rfl
#align option.map₂_none_right Option.map₂_none_right
@[simp]
theorem map₂_coe_left (f : α → β → γ) (a : α) (b : Option β) : map₂ f a b = b.map fun b => f a b :=
rfl
#align option.map₂_coe_left Option.map₂_coe_left
-- Porting note: This proof was `rfl` in Lean3, but now is not.
@[simp]
theorem map₂_coe_right (f : α → β → γ) (a : Option α) (b : β) :
map₂ f a b = a.map fun a => f a b := by cases a <;> rfl
#align option.map₂_coe_right Option.map₂_coe_right
-- Porting note: Removed the `@[simp]` tag as membership of an `Option` is no-longer simp-normal.
theorem mem_map₂_iff {c : γ} : c ∈ map₂ f a b ↔ ∃ a' b', a' ∈ a ∧ b' ∈ b ∧ f a' b' = c := by
simp [map₂, bind_eq_some]
#align option.mem_map₂_iff Option.mem_map₂_iff
@[simp]
| Mathlib/Data/Option/NAry.lean | 83 | 84 | theorem map₂_eq_none_iff : map₂ f a b = none ↔ a = none ∨ b = none := by |
cases a <;> cases b <;> simp
|
import Mathlib.SetTheory.Game.Basic
import Mathlib.Tactic.NthRewrite
#align_import set_theory.game.impartial from "leanprover-community/mathlib"@"2e0975f6a25dd3fbfb9e41556a77f075f6269748"
universe u
namespace SetTheory
open scoped PGame
namespace PGame
def ImpartialAux : PGame → Prop
| G => (G ≈ -G) ∧ (∀ i, ImpartialAux (G.moveLeft i)) ∧ ∀ j, ImpartialAux (G.moveRight j)
termination_by G => G -- Porting note: Added `termination_by`
#align pgame.impartial_aux SetTheory.PGame.ImpartialAux
theorem impartialAux_def {G : PGame} :
G.ImpartialAux ↔
(G ≈ -G) ∧ (∀ i, ImpartialAux (G.moveLeft i)) ∧ ∀ j, ImpartialAux (G.moveRight j) := by
rw [ImpartialAux]
#align pgame.impartial_aux_def SetTheory.PGame.impartialAux_def
class Impartial (G : PGame) : Prop where
out : ImpartialAux G
#align pgame.impartial SetTheory.PGame.Impartial
theorem impartial_iff_aux {G : PGame} : G.Impartial ↔ G.ImpartialAux :=
⟨fun h => h.1, fun h => ⟨h⟩⟩
#align pgame.impartial_iff_aux SetTheory.PGame.impartial_iff_aux
theorem impartial_def {G : PGame} :
G.Impartial ↔ (G ≈ -G) ∧ (∀ i, Impartial (G.moveLeft i)) ∧ ∀ j, Impartial (G.moveRight j) := by
simpa only [impartial_iff_aux] using impartialAux_def
#align pgame.impartial_def SetTheory.PGame.impartial_def
namespace Impartial
instance impartial_zero : Impartial 0 := by rw [impartial_def]; dsimp; simp
#align pgame.impartial.impartial_zero SetTheory.PGame.Impartial.impartial_zero
instance impartial_star : Impartial star := by
rw [impartial_def]; simpa using Impartial.impartial_zero
#align pgame.impartial.impartial_star SetTheory.PGame.Impartial.impartial_star
theorem neg_equiv_self (G : PGame) [h : G.Impartial] : G ≈ -G :=
(impartial_def.1 h).1
#align pgame.impartial.neg_equiv_self SetTheory.PGame.Impartial.neg_equiv_self
-- Porting note: Changed `-⟦G⟧` to `-(⟦G⟧ : Quotient setoid)`
@[simp]
theorem mk'_neg_equiv_self (G : PGame) [G.Impartial] : -(⟦G⟧ : Quotient setoid) = ⟦G⟧ :=
Quot.sound (Equiv.symm (neg_equiv_self G))
#align pgame.impartial.mk_neg_equiv_self SetTheory.PGame.Impartial.mk'_neg_equiv_self
instance moveLeft_impartial {G : PGame} [h : G.Impartial] (i : G.LeftMoves) :
(G.moveLeft i).Impartial :=
(impartial_def.1 h).2.1 i
#align pgame.impartial.move_left_impartial SetTheory.PGame.Impartial.moveLeft_impartial
instance moveRight_impartial {G : PGame} [h : G.Impartial] (j : G.RightMoves) :
(G.moveRight j).Impartial :=
(impartial_def.1 h).2.2 j
#align pgame.impartial.move_right_impartial SetTheory.PGame.Impartial.moveRight_impartial
theorem impartial_congr : ∀ {G H : PGame} (_ : G ≡r H) [G.Impartial], H.Impartial
| G, H => fun e => by
intro h
exact impartial_def.2
⟨Equiv.trans e.symm.equiv (Equiv.trans (neg_equiv_self G) (neg_equiv_neg_iff.2 e.equiv)),
fun i => impartial_congr (e.moveLeftSymm i), fun j => impartial_congr (e.moveRightSymm j)⟩
termination_by G H => (G, H)
#align pgame.impartial.impartial_congr SetTheory.PGame.Impartial.impartial_congr
instance impartial_add : ∀ (G H : PGame) [G.Impartial] [H.Impartial], (G + H).Impartial
| G, H, _, _ => by
rw [impartial_def]
refine ⟨Equiv.trans (add_congr (neg_equiv_self G) (neg_equiv_self _))
(Equiv.symm (negAddRelabelling _ _).equiv), fun k => ?_, fun k => ?_⟩
· apply leftMoves_add_cases k
all_goals
intro i; simp only [add_moveLeft_inl, add_moveLeft_inr]
apply impartial_add
· apply rightMoves_add_cases k
all_goals
intro i; simp only [add_moveRight_inl, add_moveRight_inr]
apply impartial_add
termination_by G H => (G, H)
#align pgame.impartial.impartial_add SetTheory.PGame.Impartial.impartial_add
instance impartial_neg : ∀ (G : PGame) [G.Impartial], (-G).Impartial
| G, _ => by
rw [impartial_def]
refine ⟨?_, fun i => ?_, fun i => ?_⟩
· rw [neg_neg]
exact Equiv.symm (neg_equiv_self G)
· rw [moveLeft_neg']
apply impartial_neg
· rw [moveRight_neg']
apply impartial_neg
termination_by G => G
#align pgame.impartial.impartial_neg SetTheory.PGame.Impartial.impartial_neg
variable (G : PGame) [Impartial G]
theorem nonpos : ¬0 < G := fun h => by
have h' := neg_lt_neg_iff.2 h
rw [neg_zero, lt_congr_left (Equiv.symm (neg_equiv_self G))] at h'
exact (h.trans h').false
#align pgame.impartial.nonpos SetTheory.PGame.Impartial.nonpos
theorem nonneg : ¬G < 0 := fun h => by
have h' := neg_lt_neg_iff.2 h
rw [neg_zero, lt_congr_right (Equiv.symm (neg_equiv_self G))] at h'
exact (h.trans h').false
#align pgame.impartial.nonneg SetTheory.PGame.Impartial.nonneg
theorem equiv_or_fuzzy_zero : (G ≈ 0) ∨ G ‖ 0 := by
rcases lt_or_equiv_or_gt_or_fuzzy G 0 with (h | h | h | h)
· exact ((nonneg G) h).elim
· exact Or.inl h
· exact ((nonpos G) h).elim
· exact Or.inr h
#align pgame.impartial.equiv_or_fuzzy_zero SetTheory.PGame.Impartial.equiv_or_fuzzy_zero
@[simp]
theorem not_equiv_zero_iff : ¬(G ≈ 0) ↔ G ‖ 0 :=
⟨(equiv_or_fuzzy_zero G).resolve_left, Fuzzy.not_equiv⟩
#align pgame.impartial.not_equiv_zero_iff SetTheory.PGame.Impartial.not_equiv_zero_iff
@[simp]
theorem not_fuzzy_zero_iff : ¬G ‖ 0 ↔ (G ≈ 0) :=
⟨(equiv_or_fuzzy_zero G).resolve_right, Equiv.not_fuzzy⟩
#align pgame.impartial.not_fuzzy_zero_iff SetTheory.PGame.Impartial.not_fuzzy_zero_iff
theorem add_self : G + G ≈ 0 :=
Equiv.trans (add_congr_left (neg_equiv_self G)) (add_left_neg_equiv G)
#align pgame.impartial.add_self SetTheory.PGame.Impartial.add_self
-- Porting note: Changed `⟦G⟧` to `(⟦G⟧ : Quotient setoid)`
@[simp]
theorem mk'_add_self : (⟦G⟧ : Quotient setoid) + ⟦G⟧ = 0 :=
Quot.sound (add_self G)
#align pgame.impartial.mk_add_self SetTheory.PGame.Impartial.mk'_add_self
theorem equiv_iff_add_equiv_zero (H : PGame) : (H ≈ G) ↔ (H + G ≈ 0) := by
rw [Game.PGame.equiv_iff_game_eq, ← @add_right_cancel_iff _ _ _ ⟦G⟧, mk'_add_self, ← quot_add,
Game.PGame.equiv_iff_game_eq]
rfl
#align pgame.impartial.equiv_iff_add_equiv_zero SetTheory.PGame.Impartial.equiv_iff_add_equiv_zero
theorem equiv_iff_add_equiv_zero' (H : PGame) : (G ≈ H) ↔ (G + H ≈ 0) := by
rw [Game.PGame.equiv_iff_game_eq, ← @add_left_cancel_iff _ _ _ ⟦G⟧, mk'_add_self, ← quot_add,
Game.PGame.equiv_iff_game_eq]
exact ⟨Eq.symm, Eq.symm⟩
#align pgame.impartial.equiv_iff_add_equiv_zero' SetTheory.PGame.Impartial.equiv_iff_add_equiv_zero'
theorem le_zero_iff {G : PGame} [G.Impartial] : G ≤ 0 ↔ 0 ≤ G := by
rw [← zero_le_neg_iff, le_congr_right (neg_equiv_self G)]
#align pgame.impartial.le_zero_iff SetTheory.PGame.Impartial.le_zero_iff
theorem lf_zero_iff {G : PGame} [G.Impartial] : G ⧏ 0 ↔ 0 ⧏ G := by
rw [← zero_lf_neg_iff, lf_congr_right (neg_equiv_self G)]
#align pgame.impartial.lf_zero_iff SetTheory.PGame.Impartial.lf_zero_iff
theorem equiv_zero_iff_le : (G ≈ 0) ↔ G ≤ 0 :=
⟨And.left, fun h => ⟨h, le_zero_iff.1 h⟩⟩
#align pgame.impartial.equiv_zero_iff_le SetTheory.PGame.Impartial.equiv_zero_iff_le
theorem fuzzy_zero_iff_lf : G ‖ 0 ↔ G ⧏ 0 :=
⟨And.left, fun h => ⟨h, lf_zero_iff.1 h⟩⟩
#align pgame.impartial.fuzzy_zero_iff_lf SetTheory.PGame.Impartial.fuzzy_zero_iff_lf
theorem equiv_zero_iff_ge : (G ≈ 0) ↔ 0 ≤ G :=
⟨And.right, fun h => ⟨le_zero_iff.2 h, h⟩⟩
#align pgame.impartial.equiv_zero_iff_ge SetTheory.PGame.Impartial.equiv_zero_iff_ge
theorem fuzzy_zero_iff_gf : G ‖ 0 ↔ 0 ⧏ G :=
⟨And.right, fun h => ⟨lf_zero_iff.2 h, h⟩⟩
#align pgame.impartial.fuzzy_zero_iff_gf SetTheory.PGame.Impartial.fuzzy_zero_iff_gf
| Mathlib/SetTheory/Game/Impartial.lean | 203 | 208 | theorem forall_leftMoves_fuzzy_iff_equiv_zero : (∀ i, G.moveLeft i ‖ 0) ↔ (G ≈ 0) := by |
refine ⟨fun hb => ?_, fun hp i => ?_⟩
· rw [equiv_zero_iff_le G, le_zero_lf]
exact fun i => (hb i).1
· rw [fuzzy_zero_iff_lf]
exact hp.1.moveLeft_lf i
|
import Mathlib.MeasureTheory.Function.LpOrder
#align_import measure_theory.function.l1_space from "leanprover-community/mathlib"@"ccdbfb6e5614667af5aa3ab2d50885e0ef44a46f"
noncomputable section
open scoped Classical
open Topology ENNReal MeasureTheory NNReal
open Set Filter TopologicalSpace ENNReal EMetric MeasureTheory
variable {α β γ δ : Type*} {m : MeasurableSpace α} {μ ν : Measure α} [MeasurableSpace δ]
variable [NormedAddCommGroup β]
variable [NormedAddCommGroup γ]
namespace MeasureTheory
theorem lintegral_nnnorm_eq_lintegral_edist (f : α → β) :
∫⁻ a, ‖f a‖₊ ∂μ = ∫⁻ a, edist (f a) 0 ∂μ := by simp only [edist_eq_coe_nnnorm]
#align measure_theory.lintegral_nnnorm_eq_lintegral_edist MeasureTheory.lintegral_nnnorm_eq_lintegral_edist
| Mathlib/MeasureTheory/Function/L1Space.lean | 70 | 72 | theorem lintegral_norm_eq_lintegral_edist (f : α → β) :
∫⁻ a, ENNReal.ofReal ‖f a‖ ∂μ = ∫⁻ a, edist (f a) 0 ∂μ := by |
simp only [ofReal_norm_eq_coe_nnnorm, edist_eq_coe_nnnorm]
|
import Mathlib.Order.Filter.Basic
import Mathlib.Data.PFun
#align_import order.filter.partial from "leanprover-community/mathlib"@"b363547b3113d350d053abdf2884e9850a56b205"
universe u v w
namespace Filter
variable {α : Type u} {β : Type v} {γ : Type w}
open Filter
def rmap (r : Rel α β) (l : Filter α) : Filter β where
sets := { s | r.core s ∈ l }
univ_sets := by simp
sets_of_superset hs st := mem_of_superset hs (Rel.core_mono _ st)
inter_sets hs ht := by
simp only [Set.mem_setOf_eq]
convert inter_mem hs ht
rw [← Rel.core_inter]
#align filter.rmap Filter.rmap
theorem rmap_sets (r : Rel α β) (l : Filter α) : (l.rmap r).sets = r.core ⁻¹' l.sets :=
rfl
#align filter.rmap_sets Filter.rmap_sets
@[simp]
theorem mem_rmap (r : Rel α β) (l : Filter α) (s : Set β) : s ∈ l.rmap r ↔ r.core s ∈ l :=
Iff.rfl
#align filter.mem_rmap Filter.mem_rmap
@[simp]
theorem rmap_rmap (r : Rel α β) (s : Rel β γ) (l : Filter α) :
rmap s (rmap r l) = rmap (r.comp s) l :=
filter_eq <| by simp [rmap_sets, Set.preimage, Rel.core_comp]
#align filter.rmap_rmap Filter.rmap_rmap
@[simp]
theorem rmap_compose (r : Rel α β) (s : Rel β γ) : rmap s ∘ rmap r = rmap (r.comp s) :=
funext <| rmap_rmap _ _
#align filter.rmap_compose Filter.rmap_compose
def RTendsto (r : Rel α β) (l₁ : Filter α) (l₂ : Filter β) :=
l₁.rmap r ≤ l₂
#align filter.rtendsto Filter.RTendsto
theorem rtendsto_def (r : Rel α β) (l₁ : Filter α) (l₂ : Filter β) :
RTendsto r l₁ l₂ ↔ ∀ s ∈ l₂, r.core s ∈ l₁ :=
Iff.rfl
#align filter.rtendsto_def Filter.rtendsto_def
def rcomap (r : Rel α β) (f : Filter β) : Filter α where
sets := Rel.image (fun s t => r.core s ⊆ t) f.sets
univ_sets := ⟨Set.univ, univ_mem, Set.subset_univ _⟩
sets_of_superset := fun ⟨a', ha', ma'a⟩ ab => ⟨a', ha', ma'a.trans ab⟩
inter_sets := fun ⟨a', ha₁, ha₂⟩ ⟨b', hb₁, hb₂⟩ =>
⟨a' ∩ b', inter_mem ha₁ hb₁, (r.core_inter a' b').subset.trans (Set.inter_subset_inter ha₂ hb₂)⟩
#align filter.rcomap Filter.rcomap
theorem rcomap_sets (r : Rel α β) (f : Filter β) :
(rcomap r f).sets = Rel.image (fun s t => r.core s ⊆ t) f.sets :=
rfl
#align filter.rcomap_sets Filter.rcomap_sets
theorem rcomap_rcomap (r : Rel α β) (s : Rel β γ) (l : Filter γ) :
rcomap r (rcomap s l) = rcomap (r.comp s) l :=
filter_eq <| by
ext t; simp [rcomap_sets, Rel.image, Rel.core_comp]; constructor
· rintro ⟨u, ⟨v, vsets, hv⟩, h⟩
exact ⟨v, vsets, Set.Subset.trans (Rel.core_mono _ hv) h⟩
rintro ⟨t, tsets, ht⟩
exact ⟨Rel.core s t, ⟨t, tsets, Set.Subset.rfl⟩, ht⟩
#align filter.rcomap_rcomap Filter.rcomap_rcomap
@[simp]
theorem rcomap_compose (r : Rel α β) (s : Rel β γ) : rcomap r ∘ rcomap s = rcomap (r.comp s) :=
funext <| rcomap_rcomap _ _
#align filter.rcomap_compose Filter.rcomap_compose
theorem rtendsto_iff_le_rcomap (r : Rel α β) (l₁ : Filter α) (l₂ : Filter β) :
RTendsto r l₁ l₂ ↔ l₁ ≤ l₂.rcomap r := by
rw [rtendsto_def]
simp_rw [← l₂.mem_sets]
simp [Filter.le_def, rcomap, Rel.mem_image]; constructor
· exact fun h s t tl₂ => mem_of_superset (h t tl₂)
· exact fun h t tl₂ => h _ t tl₂ Set.Subset.rfl
#align filter.rtendsto_iff_le_rcomap Filter.rtendsto_iff_le_rcomap
-- Interestingly, there does not seem to be a way to express this relation using a forward map.
-- Given a filter `f` on `α`, we want a filter `f'` on `β` such that `r.preimage s ∈ f` if
-- and only if `s ∈ f'`. But the intersection of two sets satisfying the lhs may be empty.
def rcomap' (r : Rel α β) (f : Filter β) : Filter α where
sets := Rel.image (fun s t => r.preimage s ⊆ t) f.sets
univ_sets := ⟨Set.univ, univ_mem, Set.subset_univ _⟩
sets_of_superset := fun ⟨a', ha', ma'a⟩ ab => ⟨a', ha', ma'a.trans ab⟩
inter_sets := fun ⟨a', ha₁, ha₂⟩ ⟨b', hb₁, hb₂⟩ =>
⟨a' ∩ b', inter_mem ha₁ hb₁,
(@Rel.preimage_inter _ _ r _ _).trans (Set.inter_subset_inter ha₂ hb₂)⟩
#align filter.rcomap' Filter.rcomap'
@[simp]
theorem mem_rcomap' (r : Rel α β) (l : Filter β) (s : Set α) :
s ∈ l.rcomap' r ↔ ∃ t ∈ l, r.preimage t ⊆ s :=
Iff.rfl
#align filter.mem_rcomap' Filter.mem_rcomap'
theorem rcomap'_sets (r : Rel α β) (f : Filter β) :
(rcomap' r f).sets = Rel.image (fun s t => r.preimage s ⊆ t) f.sets :=
rfl
#align filter.rcomap'_sets Filter.rcomap'_sets
@[simp]
theorem rcomap'_rcomap' (r : Rel α β) (s : Rel β γ) (l : Filter γ) :
rcomap' r (rcomap' s l) = rcomap' (r.comp s) l :=
Filter.ext fun t => by
simp only [mem_rcomap', Rel.preimage_comp]
constructor
· rintro ⟨u, ⟨v, vsets, hv⟩, h⟩
exact ⟨v, vsets, (Rel.preimage_mono _ hv).trans h⟩
rintro ⟨t, tsets, ht⟩
exact ⟨s.preimage t, ⟨t, tsets, Set.Subset.rfl⟩, ht⟩
#align filter.rcomap'_rcomap' Filter.rcomap'_rcomap'
@[simp]
theorem rcomap'_compose (r : Rel α β) (s : Rel β γ) : rcomap' r ∘ rcomap' s = rcomap' (r.comp s) :=
funext <| rcomap'_rcomap' _ _
#align filter.rcomap'_compose Filter.rcomap'_compose
def RTendsto' (r : Rel α β) (l₁ : Filter α) (l₂ : Filter β) :=
l₁ ≤ l₂.rcomap' r
#align filter.rtendsto' Filter.RTendsto'
| Mathlib/Order/Filter/Partial.lean | 188 | 192 | theorem rtendsto'_def (r : Rel α β) (l₁ : Filter α) (l₂ : Filter β) :
RTendsto' r l₁ l₂ ↔ ∀ s ∈ l₂, r.preimage s ∈ l₁ := by |
unfold RTendsto' rcomap'; simp [le_def, Rel.mem_image]; constructor
· exact fun h s hs => h _ _ hs Set.Subset.rfl
· exact fun h s t ht => mem_of_superset (h t ht)
|
import Mathlib.Data.Int.Range
import Mathlib.Data.ZMod.Basic
import Mathlib.NumberTheory.MulChar.Basic
#align_import number_theory.legendre_symbol.zmod_char from "leanprover-community/mathlib"@"70fd9563a21e7b963887c9360bd29b2393e6225a"
namespace ZMod
section QuadCharModP
@[simps]
def χ₄ : MulChar (ZMod 4) ℤ where
toFun := (![0, 1, 0, -1] : ZMod 4 → ℤ)
map_one' := rfl
map_mul' := by decide
map_nonunit' := by decide
#align zmod.χ₄ ZMod.χ₄
theorem isQuadratic_χ₄ : χ₄.IsQuadratic := by
intro a
-- Porting note (#11043): was `decide!`
fin_cases a
all_goals decide
#align zmod.is_quadratic_χ₄ ZMod.isQuadratic_χ₄
theorem χ₄_nat_mod_four (n : ℕ) : χ₄ n = χ₄ (n % 4 : ℕ) := by rw [← ZMod.natCast_mod n 4]
#align zmod.χ₄_nat_mod_four ZMod.χ₄_nat_mod_four
theorem χ₄_int_mod_four (n : ℤ) : χ₄ n = χ₄ (n % 4 : ℤ) := by
rw [← ZMod.intCast_mod n 4]
norm_cast
#align zmod.χ₄_int_mod_four ZMod.χ₄_int_mod_four
theorem χ₄_int_eq_if_mod_four (n : ℤ) :
χ₄ n = if n % 2 = 0 then 0 else if n % 4 = 1 then 1 else -1 := by
have help : ∀ m : ℤ, 0 ≤ m → m < 4 → χ₄ m = if m % 2 = 0 then 0 else if m = 1 then 1 else -1 := by
decide
rw [← Int.emod_emod_of_dvd n (by decide : (2 : ℤ) ∣ 4), ← ZMod.intCast_mod n 4]
exact help (n % 4) (Int.emod_nonneg n (by norm_num)) (Int.emod_lt n (by norm_num))
#align zmod.χ₄_int_eq_if_mod_four ZMod.χ₄_int_eq_if_mod_four
theorem χ₄_nat_eq_if_mod_four (n : ℕ) :
χ₄ n = if n % 2 = 0 then 0 else if n % 4 = 1 then 1 else -1 :=
mod_cast χ₄_int_eq_if_mod_four n
#align zmod.χ₄_nat_eq_if_mod_four ZMod.χ₄_nat_eq_if_mod_four
theorem χ₄_eq_neg_one_pow {n : ℕ} (hn : n % 2 = 1) : χ₄ n = (-1) ^ (n / 2) := by
rw [χ₄_nat_eq_if_mod_four]
simp only [hn, Nat.one_ne_zero, if_false]
conv_rhs => -- Porting note: was `nth_rw`
arg 2; rw [← Nat.div_add_mod n 4]
enter [1, 1, 1]; rw [(by norm_num : 4 = 2 * 2)]
rw [mul_assoc, add_comm, Nat.add_mul_div_left _ _ (by norm_num : 0 < 2), pow_add, pow_mul,
neg_one_sq, one_pow, mul_one]
have help : ∀ m : ℕ, m < 4 → m % 2 = 1 → ite (m = 1) (1 : ℤ) (-1) = (-1) ^ (m / 2) := by decide
exact
help (n % 4) (Nat.mod_lt n (by norm_num))
((Nat.mod_mod_of_dvd n (by decide : 2 ∣ 4)).trans hn)
#align zmod.χ₄_eq_neg_one_pow ZMod.χ₄_eq_neg_one_pow
theorem χ₄_nat_one_mod_four {n : ℕ} (hn : n % 4 = 1) : χ₄ n = 1 := by
rw [χ₄_nat_mod_four, hn]
rfl
#align zmod.χ₄_nat_one_mod_four ZMod.χ₄_nat_one_mod_four
theorem χ₄_nat_three_mod_four {n : ℕ} (hn : n % 4 = 3) : χ₄ n = -1 := by
rw [χ₄_nat_mod_four, hn]
rfl
#align zmod.χ₄_nat_three_mod_four ZMod.χ₄_nat_three_mod_four
theorem χ₄_int_one_mod_four {n : ℤ} (hn : n % 4 = 1) : χ₄ n = 1 := by
rw [χ₄_int_mod_four, hn]
rfl
#align zmod.χ₄_int_one_mod_four ZMod.χ₄_int_one_mod_four
theorem χ₄_int_three_mod_four {n : ℤ} (hn : n % 4 = 3) : χ₄ n = -1 := by
rw [χ₄_int_mod_four, hn]
rfl
#align zmod.χ₄_int_three_mod_four ZMod.χ₄_int_three_mod_four
theorem neg_one_pow_div_two_of_one_mod_four {n : ℕ} (hn : n % 4 = 1) : (-1 : ℤ) ^ (n / 2) = 1 := by
rw [← χ₄_eq_neg_one_pow (Nat.odd_of_mod_four_eq_one hn), ← natCast_mod, hn]
rfl
#align zmod.neg_one_pow_div_two_of_one_mod_four ZMod.neg_one_pow_div_two_of_one_mod_four
theorem neg_one_pow_div_two_of_three_mod_four {n : ℕ} (hn : n % 4 = 3) :
(-1 : ℤ) ^ (n / 2) = -1 := by
rw [← χ₄_eq_neg_one_pow (Nat.odd_of_mod_four_eq_three hn), ← natCast_mod, hn]
rfl
#align zmod.neg_one_pow_div_two_of_three_mod_four ZMod.neg_one_pow_div_two_of_three_mod_four
@[simps]
def χ₈ : MulChar (ZMod 8) ℤ where
toFun := (![0, 1, 0, -1, 0, -1, 0, 1] : ZMod 8 → ℤ)
map_one' := rfl
map_mul' := by decide
map_nonunit' := by decide
#align zmod.χ₈ ZMod.χ₈
theorem isQuadratic_χ₈ : χ₈.IsQuadratic := by
intro a
-- Porting note: was `decide!`
fin_cases a
all_goals decide
#align zmod.is_quadratic_χ₈ ZMod.isQuadratic_χ₈
theorem χ₈_nat_mod_eight (n : ℕ) : χ₈ n = χ₈ (n % 8 : ℕ) := by rw [← ZMod.natCast_mod n 8]
#align zmod.χ₈_nat_mod_eight ZMod.χ₈_nat_mod_eight
theorem χ₈_int_mod_eight (n : ℤ) : χ₈ n = χ₈ (n % 8 : ℤ) := by
rw [← ZMod.intCast_mod n 8]
norm_cast
#align zmod.χ₈_int_mod_eight ZMod.χ₈_int_mod_eight
theorem χ₈_int_eq_if_mod_eight (n : ℤ) :
χ₈ n = if n % 2 = 0 then 0 else if n % 8 = 1 ∨ n % 8 = 7 then 1 else -1 := by
have help :
∀ m : ℤ, 0 ≤ m → m < 8 → χ₈ m = if m % 2 = 0 then 0 else if m = 1 ∨ m = 7 then 1 else -1 := by
decide
rw [← Int.emod_emod_of_dvd n (by decide : (2 : ℤ) ∣ 8), ← ZMod.intCast_mod n 8]
exact help (n % 8) (Int.emod_nonneg n (by norm_num)) (Int.emod_lt n (by norm_num))
#align zmod.χ₈_int_eq_if_mod_eight ZMod.χ₈_int_eq_if_mod_eight
theorem χ₈_nat_eq_if_mod_eight (n : ℕ) :
χ₈ n = if n % 2 = 0 then 0 else if n % 8 = 1 ∨ n % 8 = 7 then 1 else -1 :=
mod_cast χ₈_int_eq_if_mod_eight n
#align zmod.χ₈_nat_eq_if_mod_eight ZMod.χ₈_nat_eq_if_mod_eight
@[simps]
def χ₈' : MulChar (ZMod 8) ℤ where
toFun := (![0, 1, 0, 1, 0, -1, 0, -1] : ZMod 8 → ℤ)
map_one' := rfl
map_mul' := by decide
map_nonunit' := by decide
#align zmod.χ₈' ZMod.χ₈'
theorem isQuadratic_χ₈' : χ₈'.IsQuadratic := by
intro a
-- Porting note: was `decide!`
fin_cases a
all_goals decide
#align zmod.is_quadratic_χ₈' ZMod.isQuadratic_χ₈'
| Mathlib/NumberTheory/LegendreSymbol/ZModChar.lean | 193 | 199 | theorem χ₈'_int_eq_if_mod_eight (n : ℤ) :
χ₈' n = if n % 2 = 0 then 0 else if n % 8 = 1 ∨ n % 8 = 3 then 1 else -1 := by |
have help :
∀ m : ℤ, 0 ≤ m → m < 8 → χ₈' m = if m % 2 = 0 then 0 else if m = 1 ∨ m = 3 then 1 else -1 := by
decide
rw [← Int.emod_emod_of_dvd n (by decide : (2 : ℤ) ∣ 8), ← ZMod.intCast_mod n 8]
exact help (n % 8) (Int.emod_nonneg n (by norm_num)) (Int.emod_lt n (by norm_num))
|
import Mathlib.Order.PropInstances
#align_import order.heyting.basic from "leanprover-community/mathlib"@"9ac7c0c8c4d7a535ec3e5b34b8859aab9233b2f4"
open Function OrderDual
universe u
variable {ι α β : Type*}
section
variable (α β)
instance Prod.instHImp [HImp α] [HImp β] : HImp (α × β) :=
⟨fun a b => (a.1 ⇨ b.1, a.2 ⇨ b.2)⟩
instance Prod.instHNot [HNot α] [HNot β] : HNot (α × β) :=
⟨fun a => (￢a.1, ￢a.2)⟩
instance Prod.instSDiff [SDiff α] [SDiff β] : SDiff (α × β) :=
⟨fun a b => (a.1 \ b.1, a.2 \ b.2)⟩
instance Prod.instHasCompl [HasCompl α] [HasCompl β] : HasCompl (α × β) :=
⟨fun a => (a.1ᶜ, a.2ᶜ)⟩
end
@[simp]
theorem fst_himp [HImp α] [HImp β] (a b : α × β) : (a ⇨ b).1 = a.1 ⇨ b.1 :=
rfl
#align fst_himp fst_himp
@[simp]
theorem snd_himp [HImp α] [HImp β] (a b : α × β) : (a ⇨ b).2 = a.2 ⇨ b.2 :=
rfl
#align snd_himp snd_himp
@[simp]
theorem fst_hnot [HNot α] [HNot β] (a : α × β) : (￢a).1 = ￢a.1 :=
rfl
#align fst_hnot fst_hnot
@[simp]
theorem snd_hnot [HNot α] [HNot β] (a : α × β) : (￢a).2 = ￢a.2 :=
rfl
#align snd_hnot snd_hnot
@[simp]
theorem fst_sdiff [SDiff α] [SDiff β] (a b : α × β) : (a \ b).1 = a.1 \ b.1 :=
rfl
#align fst_sdiff fst_sdiff
@[simp]
theorem snd_sdiff [SDiff α] [SDiff β] (a b : α × β) : (a \ b).2 = a.2 \ b.2 :=
rfl
#align snd_sdiff snd_sdiff
@[simp]
theorem fst_compl [HasCompl α] [HasCompl β] (a : α × β) : aᶜ.1 = a.1ᶜ :=
rfl
#align fst_compl fst_compl
@[simp]
theorem snd_compl [HasCompl α] [HasCompl β] (a : α × β) : aᶜ.2 = a.2ᶜ :=
rfl
#align snd_compl snd_compl
class GeneralizedHeytingAlgebra (α : Type*) extends Lattice α, OrderTop α, HImp α where
le_himp_iff (a b c : α) : a ≤ b ⇨ c ↔ a ⊓ b ≤ c
#align generalized_heyting_algebra GeneralizedHeytingAlgebra
#align generalized_heyting_algebra.to_order_top GeneralizedHeytingAlgebra.toOrderTop
class GeneralizedCoheytingAlgebra (α : Type*) extends Lattice α, OrderBot α, SDiff α where
sdiff_le_iff (a b c : α) : a \ b ≤ c ↔ a ≤ b ⊔ c
#align generalized_coheyting_algebra GeneralizedCoheytingAlgebra
#align generalized_coheyting_algebra.to_order_bot GeneralizedCoheytingAlgebra.toOrderBot
class HeytingAlgebra (α : Type*) extends GeneralizedHeytingAlgebra α, OrderBot α, HasCompl α where
himp_bot (a : α) : a ⇨ ⊥ = aᶜ
#align heyting_algebra HeytingAlgebra
class CoheytingAlgebra (α : Type*) extends GeneralizedCoheytingAlgebra α, OrderTop α, HNot α where
top_sdiff (a : α) : ⊤ \ a = ￢a
#align coheyting_algebra CoheytingAlgebra
class BiheytingAlgebra (α : Type*) extends HeytingAlgebra α, SDiff α, HNot α where
sdiff_le_iff (a b c : α) : a \ b ≤ c ↔ a ≤ b ⊔ c
top_sdiff (a : α) : ⊤ \ a = ￢a
#align biheyting_algebra BiheytingAlgebra
-- See note [lower instance priority]
attribute [instance 100] GeneralizedHeytingAlgebra.toOrderTop
attribute [instance 100] GeneralizedCoheytingAlgebra.toOrderBot
-- See note [lower instance priority]
instance (priority := 100) HeytingAlgebra.toBoundedOrder [HeytingAlgebra α] : BoundedOrder α :=
{ bot_le := ‹HeytingAlgebra α›.bot_le }
--#align heyting_algebra.to_bounded_order HeytingAlgebra.toBoundedOrder
-- See note [lower instance priority]
instance (priority := 100) CoheytingAlgebra.toBoundedOrder [CoheytingAlgebra α] : BoundedOrder α :=
{ ‹CoheytingAlgebra α› with }
#align coheyting_algebra.to_bounded_order CoheytingAlgebra.toBoundedOrder
-- See note [lower instance priority]
instance (priority := 100) BiheytingAlgebra.toCoheytingAlgebra [BiheytingAlgebra α] :
CoheytingAlgebra α :=
{ ‹BiheytingAlgebra α› with }
#align biheyting_algebra.to_coheyting_algebra BiheytingAlgebra.toCoheytingAlgebra
-- See note [reducible non-instances]
abbrev HeytingAlgebra.ofHImp [DistribLattice α] [BoundedOrder α] (himp : α → α → α)
(le_himp_iff : ∀ a b c, a ≤ himp b c ↔ a ⊓ b ≤ c) : HeytingAlgebra α :=
{ ‹DistribLattice α›, ‹BoundedOrder α› with
himp,
compl := fun a => himp a ⊥,
le_himp_iff,
himp_bot := fun a => rfl }
#align heyting_algebra.of_himp HeytingAlgebra.ofHImp
-- See note [reducible non-instances]
abbrev HeytingAlgebra.ofCompl [DistribLattice α] [BoundedOrder α] (compl : α → α)
(le_himp_iff : ∀ a b c, a ≤ compl b ⊔ c ↔ a ⊓ b ≤ c) : HeytingAlgebra α where
himp := (compl · ⊔ ·)
compl := compl
le_himp_iff := le_himp_iff
himp_bot _ := sup_bot_eq _
#align heyting_algebra.of_compl HeytingAlgebra.ofCompl
-- See note [reducible non-instances]
abbrev CoheytingAlgebra.ofSDiff [DistribLattice α] [BoundedOrder α] (sdiff : α → α → α)
(sdiff_le_iff : ∀ a b c, sdiff a b ≤ c ↔ a ≤ b ⊔ c) : CoheytingAlgebra α :=
{ ‹DistribLattice α›, ‹BoundedOrder α› with
sdiff,
hnot := fun a => sdiff ⊤ a,
sdiff_le_iff,
top_sdiff := fun a => rfl }
#align coheyting_algebra.of_sdiff CoheytingAlgebra.ofSDiff
-- See note [reducible non-instances]
abbrev CoheytingAlgebra.ofHNot [DistribLattice α] [BoundedOrder α] (hnot : α → α)
(sdiff_le_iff : ∀ a b c, a ⊓ hnot b ≤ c ↔ a ≤ b ⊔ c) : CoheytingAlgebra α where
sdiff a b := a ⊓ hnot b
hnot := hnot
sdiff_le_iff := sdiff_le_iff
top_sdiff _ := top_inf_eq _
#align coheyting_algebra.of_hnot CoheytingAlgebra.ofHNot
section GeneralizedCoheytingAlgebra
variable [GeneralizedCoheytingAlgebra α] {a b c d : α}
@[simp]
theorem sdiff_le_iff : a \ b ≤ c ↔ a ≤ b ⊔ c :=
GeneralizedCoheytingAlgebra.sdiff_le_iff _ _ _
#align sdiff_le_iff sdiff_le_iff
theorem sdiff_le_iff' : a \ b ≤ c ↔ a ≤ c ⊔ b := by rw [sdiff_le_iff, sup_comm]
#align sdiff_le_iff' sdiff_le_iff'
theorem sdiff_le_comm : a \ b ≤ c ↔ a \ c ≤ b := by rw [sdiff_le_iff, sdiff_le_iff']
#align sdiff_le_comm sdiff_le_comm
theorem sdiff_le : a \ b ≤ a :=
sdiff_le_iff.2 le_sup_right
#align sdiff_le sdiff_le
theorem Disjoint.disjoint_sdiff_left (h : Disjoint a b) : Disjoint (a \ c) b :=
h.mono_left sdiff_le
#align disjoint.disjoint_sdiff_left Disjoint.disjoint_sdiff_left
theorem Disjoint.disjoint_sdiff_right (h : Disjoint a b) : Disjoint a (b \ c) :=
h.mono_right sdiff_le
#align disjoint.disjoint_sdiff_right Disjoint.disjoint_sdiff_right
theorem sdiff_le_iff_left : a \ b ≤ b ↔ a ≤ b := by rw [sdiff_le_iff, sup_idem]
#align sdiff_le_iff_left sdiff_le_iff_left
@[simp]
theorem sdiff_self : a \ a = ⊥ :=
le_bot_iff.1 <| sdiff_le_iff.2 le_sup_left
#align sdiff_self sdiff_self
theorem le_sup_sdiff : a ≤ b ⊔ a \ b :=
sdiff_le_iff.1 le_rfl
#align le_sup_sdiff le_sup_sdiff
theorem le_sdiff_sup : a ≤ a \ b ⊔ b := by rw [sup_comm, ← sdiff_le_iff]
#align le_sdiff_sup le_sdiff_sup
theorem sup_sdiff_left : a ⊔ a \ b = a :=
sup_of_le_left sdiff_le
#align sup_sdiff_left sup_sdiff_left
theorem sup_sdiff_right : a \ b ⊔ a = a :=
sup_of_le_right sdiff_le
#align sup_sdiff_right sup_sdiff_right
theorem inf_sdiff_left : a \ b ⊓ a = a \ b :=
inf_of_le_left sdiff_le
#align inf_sdiff_left inf_sdiff_left
theorem inf_sdiff_right : a ⊓ a \ b = a \ b :=
inf_of_le_right sdiff_le
#align inf_sdiff_right inf_sdiff_right
@[simp]
theorem sup_sdiff_self (a b : α) : a ⊔ b \ a = a ⊔ b :=
le_antisymm (sup_le_sup_left sdiff_le _) (sup_le le_sup_left le_sup_sdiff)
#align sup_sdiff_self sup_sdiff_self
@[simp]
theorem sdiff_sup_self (a b : α) : b \ a ⊔ a = b ⊔ a := by rw [sup_comm, sup_sdiff_self, sup_comm]
#align sdiff_sup_self sdiff_sup_self
alias sup_sdiff_self_left := sdiff_sup_self
#align sup_sdiff_self_left sup_sdiff_self_left
alias sup_sdiff_self_right := sup_sdiff_self
#align sup_sdiff_self_right sup_sdiff_self_right
theorem sup_sdiff_eq_sup (h : c ≤ a) : a ⊔ b \ c = a ⊔ b :=
sup_congr_left (sdiff_le.trans le_sup_right) <| le_sup_sdiff.trans <| sup_le_sup_right h _
#align sup_sdiff_eq_sup sup_sdiff_eq_sup
-- cf. `Set.union_diff_cancel'`
theorem sup_sdiff_cancel' (hab : a ≤ b) (hbc : b ≤ c) : b ⊔ c \ a = c := by
rw [sup_sdiff_eq_sup hab, sup_of_le_right hbc]
#align sup_sdiff_cancel' sup_sdiff_cancel'
theorem sup_sdiff_cancel_right (h : a ≤ b) : a ⊔ b \ a = b :=
sup_sdiff_cancel' le_rfl h
#align sup_sdiff_cancel_right sup_sdiff_cancel_right
theorem sdiff_sup_cancel (h : b ≤ a) : a \ b ⊔ b = a := by rw [sup_comm, sup_sdiff_cancel_right h]
#align sdiff_sup_cancel sdiff_sup_cancel
theorem sup_le_of_le_sdiff_left (h : b ≤ c \ a) (hac : a ≤ c) : a ⊔ b ≤ c :=
sup_le hac <| h.trans sdiff_le
#align sup_le_of_le_sdiff_left sup_le_of_le_sdiff_left
theorem sup_le_of_le_sdiff_right (h : a ≤ c \ b) (hbc : b ≤ c) : a ⊔ b ≤ c :=
sup_le (h.trans sdiff_le) hbc
#align sup_le_of_le_sdiff_right sup_le_of_le_sdiff_right
@[simp]
| Mathlib/Order/Heyting/Basic.lean | 533 | 533 | theorem sdiff_eq_bot_iff : a \ b = ⊥ ↔ a ≤ b := by | rw [← le_bot_iff, sdiff_le_iff, sup_bot_eq]
|
import Mathlib.Topology.Order.ProjIcc
import Mathlib.Topology.CompactOpen
import Mathlib.Topology.UnitInterval
#align_import topology.path_connected from "leanprover-community/mathlib"@"f2ce6086713c78a7f880485f7917ea547a215982"
noncomputable section
open scoped Classical
open Topology Filter unitInterval Set Function
variable {X Y : Type*} [TopologicalSpace X] [TopologicalSpace Y] {x y z : X} {ι : Type*}
-- porting note (#5171): removed @[nolint has_nonempty_instance]
structure Path (x y : X) extends C(I, X) where
source' : toFun 0 = x
target' : toFun 1 = y
#align path Path
instance Path.funLike : FunLike (Path x y) I X where
coe := fun γ ↦ ⇑γ.toContinuousMap
coe_injective' := fun γ₁ γ₂ h => by
simp only [DFunLike.coe_fn_eq] at h
cases γ₁; cases γ₂; congr
-- Porting note (#10754): added this instance so that we can use `FunLike.coe` for `CoeFun`
-- this also fixed very strange `simp` timeout issues
instance Path.continuousMapClass : ContinuousMapClass (Path x y) I X where
map_continuous := fun γ => show Continuous γ.toContinuousMap by continuity
-- Porting note: not necessary in light of the instance above
@[ext]
protected theorem Path.ext : ∀ {γ₁ γ₂ : Path x y}, (γ₁ : I → X) = γ₂ → γ₁ = γ₂ := by
rintro ⟨⟨x, h11⟩, h12, h13⟩ ⟨⟨x, h21⟩, h22, h23⟩ rfl
rfl
#align path.ext Path.ext
namespace Path
@[simp]
theorem coe_mk_mk (f : I → X) (h₁) (h₂ : f 0 = x) (h₃ : f 1 = y) :
⇑(mk ⟨f, h₁⟩ h₂ h₃ : Path x y) = f :=
rfl
#align path.coe_mk Path.coe_mk_mk
-- Porting note: the name `Path.coe_mk` better refers to a new lemma below
variable (γ : Path x y)
@[continuity]
protected theorem continuous : Continuous γ :=
γ.continuous_toFun
#align path.continuous Path.continuous
@[simp]
protected theorem source : γ 0 = x :=
γ.source'
#align path.source Path.source
@[simp]
protected theorem target : γ 1 = y :=
γ.target'
#align path.target Path.target
def simps.apply : I → X :=
γ
#align path.simps.apply Path.simps.apply
initialize_simps_projections Path (toFun → simps.apply, -toContinuousMap)
@[simp]
theorem coe_toContinuousMap : ⇑γ.toContinuousMap = γ :=
rfl
#align path.coe_to_continuous_map Path.coe_toContinuousMap
-- Porting note: this is needed because of the `Path.continuousMapClass` instance
@[simp]
theorem coe_mk : ⇑(γ : C(I, X)) = γ :=
rfl
instance hasUncurryPath {X α : Type*} [TopologicalSpace X] {x y : α → X} :
HasUncurry (∀ a : α, Path (x a) (y a)) (α × I) X :=
⟨fun φ p => φ p.1 p.2⟩
#align path.has_uncurry_path Path.hasUncurryPath
@[refl, simps]
def refl (x : X) : Path x x where
toFun _t := x
continuous_toFun := continuous_const
source' := rfl
target' := rfl
#align path.refl Path.refl
@[simp]
theorem refl_range {a : X} : range (Path.refl a) = {a} := by simp [Path.refl, CoeFun.coe]
#align path.refl_range Path.refl_range
@[symm, simps]
def symm (γ : Path x y) : Path y x where
toFun := γ ∘ σ
continuous_toFun := by continuity
source' := by simpa [-Path.target] using γ.target
target' := by simpa [-Path.source] using γ.source
#align path.symm Path.symm
@[simp]
theorem symm_symm (γ : Path x y) : γ.symm.symm = γ := by
ext t
show γ (σ (σ t)) = γ t
rw [unitInterval.symm_symm]
#align path.symm_symm Path.symm_symm
theorem symm_bijective : Function.Bijective (Path.symm : Path x y → Path y x) :=
Function.bijective_iff_has_inverse.mpr ⟨_, symm_symm, symm_symm⟩
@[simp]
theorem refl_symm {a : X} : (Path.refl a).symm = Path.refl a := by
ext
rfl
#align path.refl_symm Path.refl_symm
@[simp]
theorem symm_range {a b : X} (γ : Path a b) : range γ.symm = range γ := by
ext x
simp only [mem_range, Path.symm, DFunLike.coe, unitInterval.symm, SetCoe.exists, comp_apply,
Subtype.coe_mk]
constructor <;> rintro ⟨y, hy, hxy⟩ <;> refine ⟨1 - y, mem_iff_one_sub_mem.mp hy, ?_⟩ <;>
convert hxy
simp
#align path.symm_range Path.symm_range
open ContinuousMap
instance topologicalSpace : TopologicalSpace (Path x y) :=
TopologicalSpace.induced ((↑) : _ → C(I, X)) ContinuousMap.compactOpen
theorem continuous_eval : Continuous fun p : Path x y × I => p.1 p.2 :=
continuous_eval.comp <| (continuous_induced_dom (α := Path x y)).prod_map continuous_id
#align path.continuous_eval Path.continuous_eval
@[continuity]
theorem _root_.Continuous.path_eval {Y} [TopologicalSpace Y] {f : Y → Path x y} {g : Y → I}
(hf : Continuous f) (hg : Continuous g) : Continuous fun y => f y (g y) :=
Continuous.comp continuous_eval (hf.prod_mk hg)
#align continuous.path_eval Continuous.path_eval
theorem continuous_uncurry_iff {Y} [TopologicalSpace Y] {g : Y → Path x y} :
Continuous ↿g ↔ Continuous g :=
Iff.symm <| continuous_induced_rng.trans
⟨fun h => continuous_uncurry_of_continuous ⟨_, h⟩,
continuous_of_continuous_uncurry (fun (y : Y) ↦ ContinuousMap.mk (g y))⟩
#align path.continuous_uncurry_iff Path.continuous_uncurry_iff
def extend : ℝ → X :=
IccExtend zero_le_one γ
#align path.extend Path.extend
theorem _root_.Continuous.path_extend {γ : Y → Path x y} {f : Y → ℝ} (hγ : Continuous ↿γ)
(hf : Continuous f) : Continuous fun t => (γ t).extend (f t) :=
Continuous.IccExtend hγ hf
#align continuous.path_extend Continuous.path_extend
@[continuity]
theorem continuous_extend : Continuous γ.extend :=
γ.continuous.Icc_extend'
#align path.continuous_extend Path.continuous_extend
theorem _root_.Filter.Tendsto.path_extend
{l r : Y → X} {y : Y} {l₁ : Filter ℝ} {l₂ : Filter X} {γ : ∀ y, Path (l y) (r y)}
(hγ : Tendsto (↿γ) (𝓝 y ×ˢ l₁.map (projIcc 0 1 zero_le_one)) l₂) :
Tendsto (↿fun x => (γ x).extend) (𝓝 y ×ˢ l₁) l₂ :=
Filter.Tendsto.IccExtend _ hγ
#align filter.tendsto.path_extend Filter.Tendsto.path_extend
theorem _root_.ContinuousAt.path_extend {g : Y → ℝ} {l r : Y → X} (γ : ∀ y, Path (l y) (r y))
{y : Y} (hγ : ContinuousAt (↿γ) (y, projIcc 0 1 zero_le_one (g y))) (hg : ContinuousAt g y) :
ContinuousAt (fun i => (γ i).extend (g i)) y :=
hγ.IccExtend (fun x => γ x) hg
#align continuous_at.path_extend ContinuousAt.path_extend
@[simp]
theorem extend_extends {a b : X} (γ : Path a b) {t : ℝ}
(ht : t ∈ (Icc 0 1 : Set ℝ)) : γ.extend t = γ ⟨t, ht⟩ :=
IccExtend_of_mem _ γ ht
#align path.extend_extends Path.extend_extends
theorem extend_zero : γ.extend 0 = x := by simp
#align path.extend_zero Path.extend_zero
theorem extend_one : γ.extend 1 = y := by simp
#align path.extend_one Path.extend_one
@[simp]
theorem extend_extends' {a b : X} (γ : Path a b) (t : (Icc 0 1 : Set ℝ)) : γ.extend t = γ t :=
IccExtend_val _ γ t
#align path.extend_extends' Path.extend_extends'
@[simp]
theorem extend_range {a b : X} (γ : Path a b) :
range γ.extend = range γ :=
IccExtend_range _ γ
#align path.extend_range Path.extend_range
theorem extend_of_le_zero {a b : X} (γ : Path a b) {t : ℝ}
(ht : t ≤ 0) : γ.extend t = a :=
(IccExtend_of_le_left _ _ ht).trans γ.source
#align path.extend_of_le_zero Path.extend_of_le_zero
theorem extend_of_one_le {a b : X} (γ : Path a b) {t : ℝ}
(ht : 1 ≤ t) : γ.extend t = b :=
(IccExtend_of_right_le _ _ ht).trans γ.target
#align path.extend_of_one_le Path.extend_of_one_le
@[simp]
theorem refl_extend {a : X} : (Path.refl a).extend = fun _ => a :=
rfl
#align path.refl_extend Path.refl_extend
def ofLine {f : ℝ → X} (hf : ContinuousOn f I) (h₀ : f 0 = x) (h₁ : f 1 = y) : Path x y where
toFun := f ∘ ((↑) : unitInterval → ℝ)
continuous_toFun := hf.comp_continuous continuous_subtype_val Subtype.prop
source' := h₀
target' := h₁
#align path.of_line Path.ofLine
theorem ofLine_mem {f : ℝ → X} (hf : ContinuousOn f I) (h₀ : f 0 = x) (h₁ : f 1 = y) :
∀ t, ofLine hf h₀ h₁ t ∈ f '' I := fun ⟨t, t_in⟩ => ⟨t, t_in, rfl⟩
#align path.of_line_mem Path.ofLine_mem
attribute [local simp] Iic_def
set_option tactic.skipAssignedInstances false in
@[trans]
def trans (γ : Path x y) (γ' : Path y z) : Path x z where
toFun := (fun t : ℝ => if t ≤ 1 / 2 then γ.extend (2 * t) else γ'.extend (2 * t - 1)) ∘ (↑)
continuous_toFun := by
refine
(Continuous.if_le ?_ ?_ continuous_id continuous_const (by norm_num)).comp
continuous_subtype_val <;>
continuity
source' := by norm_num
target' := by norm_num
#align path.trans Path.trans
theorem trans_apply (γ : Path x y) (γ' : Path y z) (t : I) :
(γ.trans γ') t =
if h : (t : ℝ) ≤ 1 / 2 then γ ⟨2 * t, (mul_pos_mem_iff zero_lt_two).2 ⟨t.2.1, h⟩⟩
else γ' ⟨2 * t - 1, two_mul_sub_one_mem_iff.2 ⟨(not_le.1 h).le, t.2.2⟩⟩ :=
show ite _ _ _ = _ by split_ifs <;> rw [extend_extends]
#align path.trans_apply Path.trans_apply
@[simp]
theorem trans_symm (γ : Path x y) (γ' : Path y z) : (γ.trans γ').symm = γ'.symm.trans γ.symm := by
ext t
simp only [trans_apply, ← one_div, symm_apply, not_le, Function.comp_apply]
split_ifs with h h₁ h₂ <;> rw [coe_symm_eq] at h
· have ht : (t : ℝ) = 1 / 2 := by linarith
norm_num [ht]
· refine congr_arg _ (Subtype.ext ?_)
norm_num [sub_sub_eq_add_sub, mul_sub]
· refine congr_arg _ (Subtype.ext ?_)
norm_num [mul_sub, h]
ring -- TODO norm_num should really do this
· exfalso
linarith
#align path.trans_symm Path.trans_symm
@[simp]
theorem refl_trans_refl {a : X} :
(Path.refl a).trans (Path.refl a) = Path.refl a := by
ext
simp only [Path.trans, ite_self, one_div, Path.refl_extend]
rfl
#align path.refl_trans_refl Path.refl_trans_refl
theorem trans_range {a b c : X} (γ₁ : Path a b) (γ₂ : Path b c) :
range (γ₁.trans γ₂) = range γ₁ ∪ range γ₂ := by
rw [Path.trans]
apply eq_of_subset_of_subset
· rintro x ⟨⟨t, ht0, ht1⟩, hxt⟩
by_cases h : t ≤ 1 / 2
· left
use ⟨2 * t, ⟨by linarith, by linarith⟩⟩
rw [← γ₁.extend_extends]
rwa [coe_mk_mk, Function.comp_apply, if_pos h] at hxt
· right
use ⟨2 * t - 1, ⟨by linarith, by linarith⟩⟩
rw [← γ₂.extend_extends]
rwa [coe_mk_mk, Function.comp_apply, if_neg h] at hxt
· rintro x (⟨⟨t, ht0, ht1⟩, hxt⟩ | ⟨⟨t, ht0, ht1⟩, hxt⟩)
· use ⟨t / 2, ⟨by linarith, by linarith⟩⟩
have : t / 2 ≤ 1 / 2 := (div_le_div_right (zero_lt_two : (0 : ℝ) < 2)).mpr ht1
rw [coe_mk_mk, Function.comp_apply, if_pos this, Subtype.coe_mk]
ring_nf
rwa [γ₁.extend_extends]
· by_cases h : t = 0
· use ⟨1 / 2, ⟨by linarith, by linarith⟩⟩
rw [coe_mk_mk, Function.comp_apply, if_pos le_rfl, Subtype.coe_mk,
mul_one_div_cancel (two_ne_zero' ℝ)]
rw [γ₁.extend_one]
rwa [← γ₂.extend_extends, h, γ₂.extend_zero] at hxt
· use ⟨(t + 1) / 2, ⟨by linarith, by linarith⟩⟩
replace h : t ≠ 0 := h
have ht0 := lt_of_le_of_ne ht0 h.symm
have : ¬(t + 1) / 2 ≤ 1 / 2 := by
rw [not_le]
linarith
rw [coe_mk_mk, Function.comp_apply, Subtype.coe_mk, if_neg this]
ring_nf
rwa [γ₂.extend_extends]
#align path.trans_range Path.trans_range
def map' (γ : Path x y) {f : X → Y} (h : ContinuousOn f (range γ)) : Path (f x) (f y) where
toFun := f ∘ γ
continuous_toFun := h.comp_continuous γ.continuous (fun x ↦ mem_range_self x)
source' := by simp
target' := by simp
def map (γ : Path x y) {f : X → Y} (h : Continuous f) :
Path (f x) (f y) := γ.map' h.continuousOn
#align path.map Path.map
@[simp]
theorem map_coe (γ : Path x y) {f : X → Y} (h : Continuous f) :
(γ.map h : I → Y) = f ∘ γ := by
ext t
rfl
#align path.map_coe Path.map_coe
@[simp]
theorem map_symm (γ : Path x y) {f : X → Y} (h : Continuous f) :
(γ.map h).symm = γ.symm.map h :=
rfl
#align path.map_symm Path.map_symm
@[simp]
theorem map_trans (γ : Path x y) (γ' : Path y z) {f : X → Y}
(h : Continuous f) : (γ.trans γ').map h = (γ.map h).trans (γ'.map h) := by
ext t
rw [trans_apply, map_coe, Function.comp_apply, trans_apply]
split_ifs <;> rfl
#align path.map_trans Path.map_trans
@[simp]
theorem map_id (γ : Path x y) : γ.map continuous_id = γ := by
ext
rfl
#align path.map_id Path.map_id
@[simp]
| Mathlib/Topology/Connected/PathConnected.lean | 442 | 446 | theorem map_map (γ : Path x y) {Z : Type*} [TopologicalSpace Z]
{f : X → Y} (hf : Continuous f) {g : Y → Z} (hg : Continuous g) :
(γ.map hf).map hg = γ.map (hg.comp hf) := by |
ext
rfl
|
import Mathlib.Computability.Halting
#align_import computability.reduce from "leanprover-community/mathlib"@"d13b3a4a392ea7273dfa4727dbd1892e26cfd518"
universe u v w
open Function
def ManyOneReducible {α β} [Primcodable α] [Primcodable β] (p : α → Prop) (q : β → Prop) :=
∃ f, Computable f ∧ ∀ a, p a ↔ q (f a)
#align many_one_reducible ManyOneReducible
@[inherit_doc ManyOneReducible]
infixl:1000 " ≤₀ " => ManyOneReducible
theorem ManyOneReducible.mk {α β} [Primcodable α] [Primcodable β] {f : α → β} (q : β → Prop)
(h : Computable f) : (fun a => q (f a)) ≤₀ q :=
⟨f, h, fun _ => Iff.rfl⟩
#align many_one_reducible.mk ManyOneReducible.mk
@[refl]
theorem manyOneReducible_refl {α} [Primcodable α] (p : α → Prop) : p ≤₀ p :=
⟨id, Computable.id, by simp⟩
#align many_one_reducible_refl manyOneReducible_refl
@[trans]
theorem ManyOneReducible.trans {α β γ} [Primcodable α] [Primcodable β] [Primcodable γ]
{p : α → Prop} {q : β → Prop} {r : γ → Prop} : p ≤₀ q → q ≤₀ r → p ≤₀ r
| ⟨f, c₁, h₁⟩, ⟨g, c₂, h₂⟩ =>
⟨g ∘ f, c₂.comp c₁,
fun a => ⟨fun h => by erw [← h₂, ← h₁]; assumption, fun h => by rwa [h₁, h₂]⟩⟩
#align many_one_reducible.trans ManyOneReducible.trans
theorem reflexive_manyOneReducible {α} [Primcodable α] : Reflexive (@ManyOneReducible α α _ _) :=
manyOneReducible_refl
#align reflexive_many_one_reducible reflexive_manyOneReducible
theorem transitive_manyOneReducible {α} [Primcodable α] : Transitive (@ManyOneReducible α α _ _) :=
fun _ _ _ => ManyOneReducible.trans
#align transitive_many_one_reducible transitive_manyOneReducible
def OneOneReducible {α β} [Primcodable α] [Primcodable β] (p : α → Prop) (q : β → Prop) :=
∃ f, Computable f ∧ Injective f ∧ ∀ a, p a ↔ q (f a)
#align one_one_reducible OneOneReducible
@[inherit_doc OneOneReducible]
infixl:1000 " ≤₁ " => OneOneReducible
theorem OneOneReducible.mk {α β} [Primcodable α] [Primcodable β] {f : α → β} (q : β → Prop)
(h : Computable f) (i : Injective f) : (fun a => q (f a)) ≤₁ q :=
⟨f, h, i, fun _ => Iff.rfl⟩
#align one_one_reducible.mk OneOneReducible.mk
@[refl]
theorem oneOneReducible_refl {α} [Primcodable α] (p : α → Prop) : p ≤₁ p :=
⟨id, Computable.id, injective_id, by simp⟩
#align one_one_reducible_refl oneOneReducible_refl
@[trans]
theorem OneOneReducible.trans {α β γ} [Primcodable α] [Primcodable β] [Primcodable γ] {p : α → Prop}
{q : β → Prop} {r : γ → Prop} : p ≤₁ q → q ≤₁ r → p ≤₁ r
| ⟨f, c₁, i₁, h₁⟩, ⟨g, c₂, i₂, h₂⟩ =>
⟨g ∘ f, c₂.comp c₁, i₂.comp i₁, fun a =>
⟨fun h => by erw [← h₂, ← h₁]; assumption, fun h => by rwa [h₁, h₂]⟩⟩
#align one_one_reducible.trans OneOneReducible.trans
theorem OneOneReducible.to_many_one {α β} [Primcodable α] [Primcodable β] {p : α → Prop}
{q : β → Prop} : p ≤₁ q → p ≤₀ q
| ⟨f, c, _, h⟩ => ⟨f, c, h⟩
#align one_one_reducible.to_many_one OneOneReducible.to_many_one
theorem OneOneReducible.of_equiv {α β} [Primcodable α] [Primcodable β] {e : α ≃ β} (q : β → Prop)
(h : Computable e) : (q ∘ e) ≤₁ q :=
OneOneReducible.mk _ h e.injective
#align one_one_reducible.of_equiv OneOneReducible.of_equiv
theorem OneOneReducible.of_equiv_symm {α β} [Primcodable α] [Primcodable β] {e : α ≃ β}
(q : β → Prop) (h : Computable e.symm) : q ≤₁ (q ∘ e) := by
convert OneOneReducible.of_equiv _ h; funext; simp
#align one_one_reducible.of_equiv_symm OneOneReducible.of_equiv_symm
theorem reflexive_oneOneReducible {α} [Primcodable α] : Reflexive (@OneOneReducible α α _ _) :=
oneOneReducible_refl
#align reflexive_one_one_reducible reflexive_oneOneReducible
theorem transitive_oneOneReducible {α} [Primcodable α] : Transitive (@OneOneReducible α α _ _) :=
fun _ _ _ => OneOneReducible.trans
#align transitive_one_one_reducible transitive_oneOneReducible
def ManyOneEquiv {α β} [Primcodable α] [Primcodable β] (p : α → Prop) (q : β → Prop) :=
p ≤₀ q ∧ q ≤₀ p
#align many_one_equiv ManyOneEquiv
def OneOneEquiv {α β} [Primcodable α] [Primcodable β] (p : α → Prop) (q : β → Prop) :=
p ≤₁ q ∧ q ≤₁ p
#align one_one_equiv OneOneEquiv
@[refl]
theorem manyOneEquiv_refl {α} [Primcodable α] (p : α → Prop) : ManyOneEquiv p p :=
⟨manyOneReducible_refl _, manyOneReducible_refl _⟩
#align many_one_equiv_refl manyOneEquiv_refl
@[symm]
theorem ManyOneEquiv.symm {α β} [Primcodable α] [Primcodable β] {p : α → Prop} {q : β → Prop} :
ManyOneEquiv p q → ManyOneEquiv q p :=
And.symm
#align many_one_equiv.symm ManyOneEquiv.symm
@[trans]
theorem ManyOneEquiv.trans {α β γ} [Primcodable α] [Primcodable β] [Primcodable γ] {p : α → Prop}
{q : β → Prop} {r : γ → Prop} : ManyOneEquiv p q → ManyOneEquiv q r → ManyOneEquiv p r
| ⟨pq, qp⟩, ⟨qr, rq⟩ => ⟨pq.trans qr, rq.trans qp⟩
#align many_one_equiv.trans ManyOneEquiv.trans
theorem equivalence_of_manyOneEquiv {α} [Primcodable α] : Equivalence (@ManyOneEquiv α α _ _) :=
⟨manyOneEquiv_refl, fun {_ _} => ManyOneEquiv.symm, fun {_ _ _} => ManyOneEquiv.trans⟩
#align equivalence_of_many_one_equiv equivalence_of_manyOneEquiv
@[refl]
theorem oneOneEquiv_refl {α} [Primcodable α] (p : α → Prop) : OneOneEquiv p p :=
⟨oneOneReducible_refl _, oneOneReducible_refl _⟩
#align one_one_equiv_refl oneOneEquiv_refl
@[symm]
theorem OneOneEquiv.symm {α β} [Primcodable α] [Primcodable β] {p : α → Prop} {q : β → Prop} :
OneOneEquiv p q → OneOneEquiv q p :=
And.symm
#align one_one_equiv.symm OneOneEquiv.symm
@[trans]
theorem OneOneEquiv.trans {α β γ} [Primcodable α] [Primcodable β] [Primcodable γ] {p : α → Prop}
{q : β → Prop} {r : γ → Prop} : OneOneEquiv p q → OneOneEquiv q r → OneOneEquiv p r
| ⟨pq, qp⟩, ⟨qr, rq⟩ => ⟨pq.trans qr, rq.trans qp⟩
#align one_one_equiv.trans OneOneEquiv.trans
theorem equivalence_of_oneOneEquiv {α} [Primcodable α] : Equivalence (@OneOneEquiv α α _ _) :=
⟨oneOneEquiv_refl, fun {_ _} => OneOneEquiv.symm, fun {_ _ _} => OneOneEquiv.trans⟩
#align equivalence_of_one_one_equiv equivalence_of_oneOneEquiv
theorem OneOneEquiv.to_many_one {α β} [Primcodable α] [Primcodable β] {p : α → Prop}
{q : β → Prop} : OneOneEquiv p q → ManyOneEquiv p q
| ⟨pq, qp⟩ => ⟨pq.to_many_one, qp.to_many_one⟩
#align one_one_equiv.to_many_one OneOneEquiv.to_many_one
nonrec def Equiv.Computable {α β} [Primcodable α] [Primcodable β] (e : α ≃ β) :=
Computable e ∧ Computable e.symm
#align equiv.computable Equiv.Computable
theorem Equiv.Computable.symm {α β} [Primcodable α] [Primcodable β] {e : α ≃ β} :
e.Computable → e.symm.Computable :=
And.symm
#align equiv.computable.symm Equiv.Computable.symm
theorem Equiv.Computable.trans {α β γ} [Primcodable α] [Primcodable β] [Primcodable γ] {e₁ : α ≃ β}
{e₂ : β ≃ γ} : e₁.Computable → e₂.Computable → (e₁.trans e₂).Computable
| ⟨l₁, r₁⟩, ⟨l₂, r₂⟩ => ⟨l₂.comp l₁, r₁.comp r₂⟩
#align equiv.computable.trans Equiv.Computable.trans
theorem Computable.eqv (α) [Denumerable α] : (Denumerable.eqv α).Computable :=
⟨Computable.encode, Computable.ofNat _⟩
#align computable.eqv Computable.eqv
theorem Computable.equiv₂ (α β) [Denumerable α] [Denumerable β] :
(Denumerable.equiv₂ α β).Computable :=
(Computable.eqv _).trans (Computable.eqv _).symm
#align computable.equiv₂ Computable.equiv₂
theorem OneOneEquiv.of_equiv {α β} [Primcodable α] [Primcodable β] {e : α ≃ β} (h : e.Computable)
{p} : OneOneEquiv (p ∘ e) p :=
⟨OneOneReducible.of_equiv _ h.1, OneOneReducible.of_equiv_symm _ h.2⟩
#align one_one_equiv.of_equiv OneOneEquiv.of_equiv
theorem ManyOneEquiv.of_equiv {α β} [Primcodable α] [Primcodable β] {e : α ≃ β} (h : e.Computable)
{p} : ManyOneEquiv (p ∘ e) p :=
(OneOneEquiv.of_equiv h).to_many_one
#align many_one_equiv.of_equiv ManyOneEquiv.of_equiv
theorem ManyOneEquiv.le_congr_left {α β γ} [Primcodable α] [Primcodable β] [Primcodable γ]
{p : α → Prop} {q : β → Prop} {r : γ → Prop} (h : ManyOneEquiv p q) : p ≤₀ r ↔ q ≤₀ r :=
⟨h.2.trans, h.1.trans⟩
#align many_one_equiv.le_congr_left ManyOneEquiv.le_congr_left
theorem ManyOneEquiv.le_congr_right {α β γ} [Primcodable α] [Primcodable β] [Primcodable γ]
{p : α → Prop} {q : β → Prop} {r : γ → Prop} (h : ManyOneEquiv q r) : p ≤₀ q ↔ p ≤₀ r :=
⟨fun h' => h'.trans h.1, fun h' => h'.trans h.2⟩
#align many_one_equiv.le_congr_right ManyOneEquiv.le_congr_right
theorem OneOneEquiv.le_congr_left {α β γ} [Primcodable α] [Primcodable β] [Primcodable γ]
{p : α → Prop} {q : β → Prop} {r : γ → Prop} (h : OneOneEquiv p q) : p ≤₁ r ↔ q ≤₁ r :=
⟨h.2.trans, h.1.trans⟩
#align one_one_equiv.le_congr_left OneOneEquiv.le_congr_left
theorem OneOneEquiv.le_congr_right {α β γ} [Primcodable α] [Primcodable β] [Primcodable γ]
{p : α → Prop} {q : β → Prop} {r : γ → Prop} (h : OneOneEquiv q r) : p ≤₁ q ↔ p ≤₁ r :=
⟨fun h' => h'.trans h.1, fun h' => h'.trans h.2⟩
#align one_one_equiv.le_congr_right OneOneEquiv.le_congr_right
theorem ManyOneEquiv.congr_left {α β γ} [Primcodable α] [Primcodable β] [Primcodable γ]
{p : α → Prop} {q : β → Prop} {r : γ → Prop} (h : ManyOneEquiv p q) :
ManyOneEquiv p r ↔ ManyOneEquiv q r :=
and_congr h.le_congr_left h.le_congr_right
#align many_one_equiv.congr_left ManyOneEquiv.congr_left
theorem ManyOneEquiv.congr_right {α β γ} [Primcodable α] [Primcodable β] [Primcodable γ]
{p : α → Prop} {q : β → Prop} {r : γ → Prop} (h : ManyOneEquiv q r) :
ManyOneEquiv p q ↔ ManyOneEquiv p r :=
and_congr h.le_congr_right h.le_congr_left
#align many_one_equiv.congr_right ManyOneEquiv.congr_right
theorem OneOneEquiv.congr_left {α β γ} [Primcodable α] [Primcodable β] [Primcodable γ]
{p : α → Prop} {q : β → Prop} {r : γ → Prop} (h : OneOneEquiv p q) :
OneOneEquiv p r ↔ OneOneEquiv q r :=
and_congr h.le_congr_left h.le_congr_right
#align one_one_equiv.congr_left OneOneEquiv.congr_left
theorem OneOneEquiv.congr_right {α β γ} [Primcodable α] [Primcodable β] [Primcodable γ]
{p : α → Prop} {q : β → Prop} {r : γ → Prop} (h : OneOneEquiv q r) :
OneOneEquiv p q ↔ OneOneEquiv p r :=
and_congr h.le_congr_right h.le_congr_left
#align one_one_equiv.congr_right OneOneEquiv.congr_right
@[simp]
theorem ULower.down_computable {α} [Primcodable α] : (ULower.equiv α).Computable :=
⟨Primrec.ulower_down.to_comp, Primrec.ulower_up.to_comp⟩
#align ulower.down_computable ULower.down_computable
theorem manyOneEquiv_up {α} [Primcodable α] {p : α → Prop} : ManyOneEquiv (p ∘ ULower.up) p :=
ManyOneEquiv.of_equiv ULower.down_computable.symm
#align many_one_equiv_up manyOneEquiv_up
local infixl:1001 " ⊕' " => Sum.elim
open Nat.Primrec
theorem OneOneReducible.disjoin_left {α β} [Primcodable α] [Primcodable β] {p : α → Prop}
{q : β → Prop} : p ≤₁ p ⊕' q :=
⟨Sum.inl, Computable.sum_inl, fun _ _ => Sum.inl.inj_iff.1, fun _ => Iff.rfl⟩
#align one_one_reducible.disjoin_left OneOneReducible.disjoin_left
theorem OneOneReducible.disjoin_right {α β} [Primcodable α] [Primcodable β] {p : α → Prop}
{q : β → Prop} : q ≤₁ p ⊕' q :=
⟨Sum.inr, Computable.sum_inr, fun _ _ => Sum.inr.inj_iff.1, fun _ => Iff.rfl⟩
#align one_one_reducible.disjoin_right OneOneReducible.disjoin_right
theorem disjoin_manyOneReducible {α β γ} [Primcodable α] [Primcodable β] [Primcodable γ]
{p : α → Prop} {q : β → Prop} {r : γ → Prop} : p ≤₀ r → q ≤₀ r → (p ⊕' q) ≤₀ r
| ⟨f, c₁, h₁⟩, ⟨g, c₂, h₂⟩ =>
⟨Sum.elim f g,
Computable.id.sum_casesOn (c₁.comp Computable.snd).to₂ (c₂.comp Computable.snd).to₂,
fun x => by cases x <;> [apply h₁; apply h₂]⟩
#align disjoin_many_one_reducible disjoin_manyOneReducible
theorem disjoin_le {α β γ} [Primcodable α] [Primcodable β] [Primcodable γ] {p : α → Prop}
{q : β → Prop} {r : γ → Prop} : (p ⊕' q) ≤₀ r ↔ p ≤₀ r ∧ q ≤₀ r :=
⟨fun h =>
⟨OneOneReducible.disjoin_left.to_many_one.trans h,
OneOneReducible.disjoin_right.to_many_one.trans h⟩,
fun ⟨h₁, h₂⟩ => disjoin_manyOneReducible h₁ h₂⟩
#align disjoin_le disjoin_le
variable {α : Type u} [Primcodable α] [Inhabited α]
variable {β : Type v} [Primcodable β] [Inhabited β]
variable {γ : Type w} [Primcodable γ] [Inhabited γ]
def toNat (p : Set α) : Set ℕ :=
{ n | p ((Encodable.decode (α := α) n).getD default) }
#align to_nat toNat
@[simp]
theorem toNat_manyOneReducible {p : Set α} : toNat p ≤₀ p :=
⟨fun n => (Encodable.decode (α := α) n).getD default,
Computable.option_getD Computable.decode (Computable.const _), fun _ => Iff.rfl⟩
#align to_nat_many_one_reducible toNat_manyOneReducible
@[simp]
theorem manyOneReducible_toNat {p : Set α} : p ≤₀ toNat p :=
⟨Encodable.encode, Computable.encode, by simp [toNat, setOf]⟩
#align many_one_reducible_to_nat manyOneReducible_toNat
@[simp]
theorem manyOneReducible_toNat_toNat {p : Set α} {q : Set β} : toNat p ≤₀ toNat q ↔ p ≤₀ q :=
⟨fun h => manyOneReducible_toNat.trans (h.trans toNat_manyOneReducible), fun h =>
toNat_manyOneReducible.trans (h.trans manyOneReducible_toNat)⟩
#align many_one_reducible_to_nat_to_nat manyOneReducible_toNat_toNat
@[simp]
theorem toNat_manyOneEquiv {p : Set α} : ManyOneEquiv (toNat p) p := by simp [ManyOneEquiv]
#align to_nat_many_one_equiv toNat_manyOneEquiv
@[simp]
theorem manyOneEquiv_toNat (p : Set α) (q : Set β) :
ManyOneEquiv (toNat p) (toNat q) ↔ ManyOneEquiv p q := by simp [ManyOneEquiv]
#align many_one_equiv_to_nat manyOneEquiv_toNat
def ManyOneDegree : Type :=
Quotient (⟨ManyOneEquiv, equivalence_of_manyOneEquiv⟩ : Setoid (Set ℕ))
#align many_one_degree ManyOneDegree
namespace ManyOneDegree
def of (p : α → Prop) : ManyOneDegree :=
Quotient.mk'' (toNat p)
#align many_one_degree.of ManyOneDegree.of
@[elab_as_elim]
protected theorem ind_on {C : ManyOneDegree → Prop} (d : ManyOneDegree)
(h : ∀ p : Set ℕ, C (of p)) : C d :=
Quotient.inductionOn' d h
#align many_one_degree.ind_on ManyOneDegree.ind_on
-- @[elab_as_elim] -- Porting note: unexpected eliminator resulting type
protected abbrev liftOn {φ} (d : ManyOneDegree) (f : Set ℕ → φ)
(h : ∀ p q, ManyOneEquiv p q → f p = f q) : φ :=
Quotient.liftOn' d f h
#align many_one_degree.lift_on ManyOneDegree.liftOn
@[simp]
protected theorem liftOn_eq {φ} (p : Set ℕ) (f : Set ℕ → φ)
(h : ∀ p q, ManyOneEquiv p q → f p = f q) : (of p).liftOn f h = f p :=
rfl
#align many_one_degree.lift_on_eq ManyOneDegree.liftOn_eq
@[reducible, simp] -- @[elab_as_elim] -- Porting note: unexpected eliminator resulting type
protected def liftOn₂ {φ} (d₁ d₂ : ManyOneDegree) (f : Set ℕ → Set ℕ → φ)
(h : ∀ p₁ p₂ q₁ q₂, ManyOneEquiv p₁ p₂ → ManyOneEquiv q₁ q₂ → f p₁ q₁ = f p₂ q₂) : φ :=
d₁.liftOn (fun p => d₂.liftOn (f p) fun q₁ q₂ hq => h _ _ _ _ (by rfl) hq)
(by
intro p₁ p₂ hp
induction d₂ using ManyOneDegree.ind_on
apply h
· assumption
· rfl)
#align many_one_degree.lift_on₂ ManyOneDegree.liftOn₂
@[simp]
protected theorem liftOn₂_eq {φ} (p q : Set ℕ) (f : Set ℕ → Set ℕ → φ)
(h : ∀ p₁ p₂ q₁ q₂, ManyOneEquiv p₁ p₂ → ManyOneEquiv q₁ q₂ → f p₁ q₁ = f p₂ q₂) :
(of p).liftOn₂ (of q) f h = f p q :=
rfl
#align many_one_degree.lift_on₂_eq ManyOneDegree.liftOn₂_eq
@[simp]
| Mathlib/Computability/Reduce.lean | 410 | 413 | theorem of_eq_of {p : α → Prop} {q : β → Prop} : of p = of q ↔ ManyOneEquiv p q := by |
rw [of, of, Quotient.eq'']
unfold Setoid.r
simp
|
import Mathlib.Algebra.Ring.Semiconj
import Mathlib.Algebra.Ring.Units
import Mathlib.Algebra.Group.Commute.Defs
import Mathlib.Data.Bracket
#align_import algebra.ring.commute from "leanprover-community/mathlib"@"70d50ecfd4900dd6d328da39ab7ebd516abe4025"
universe u v w x
variable {α : Type u} {β : Type v} {γ : Type w} {R : Type x}
open Function
namespace Commute
@[simp]
theorem add_right [Distrib R] {a b c : R} : Commute a b → Commute a c → Commute a (b + c) :=
SemiconjBy.add_right
#align commute.add_right Commute.add_rightₓ
-- for some reason mathport expected `Semiring` instead of `Distrib`?
@[simp]
theorem add_left [Distrib R] {a b c : R} : Commute a c → Commute b c → Commute (a + b) c :=
SemiconjBy.add_left
#align commute.add_left Commute.add_leftₓ
-- for some reason mathport expected `Semiring` instead of `Distrib`?
theorem mul_self_sub_mul_self_eq [NonUnitalNonAssocRing R] {a b : R} (h : Commute a b) :
a * a - b * b = (a + b) * (a - b) := by
rw [add_mul, mul_sub, mul_sub, h.eq, sub_add_sub_cancel]
#align commute.mul_self_sub_mul_self_eq Commute.mul_self_sub_mul_self_eq
theorem mul_self_sub_mul_self_eq' [NonUnitalNonAssocRing R] {a b : R} (h : Commute a b) :
a * a - b * b = (a - b) * (a + b) := by
rw [mul_add, sub_mul, sub_mul, h.eq, sub_add_sub_cancel]
#align commute.mul_self_sub_mul_self_eq' Commute.mul_self_sub_mul_self_eq'
| Mathlib/Algebra/Ring/Commute.lean | 82 | 85 | theorem mul_self_eq_mul_self_iff [NonUnitalNonAssocRing R] [NoZeroDivisors R] {a b : R}
(h : Commute a b) : a * a = b * b ↔ a = b ∨ a = -b := by |
rw [← sub_eq_zero, h.mul_self_sub_mul_self_eq, mul_eq_zero, or_comm, sub_eq_zero,
add_eq_zero_iff_eq_neg]
|
import Mathlib.Algebra.Polynomial.AlgebraMap
import Mathlib.Algebra.Polynomial.Basic
import Mathlib.RingTheory.Ideal.Maps
import Mathlib.RingTheory.MvPowerSeries.Basic
#align_import ring_theory.power_series.basic from "leanprover-community/mathlib"@"2d5739b61641ee4e7e53eca5688a08f66f2e6a60"
noncomputable section
open Finset (antidiagonal mem_antidiagonal)
def PowerSeries (R : Type*) :=
MvPowerSeries Unit R
#align power_series PowerSeries
namespace PowerSeries
open Finsupp (single)
variable {R : Type*}
section
-- Porting note: not available in Lean 4
-- local reducible PowerSeries
scoped notation:9000 R "⟦X⟧" => PowerSeries R
instance [Inhabited R] : Inhabited R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [Zero R] : Zero R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [AddMonoid R] : AddMonoid R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [AddGroup R] : AddGroup R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [AddCommMonoid R] : AddCommMonoid R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [AddCommGroup R] : AddCommGroup R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [Semiring R] : Semiring R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [CommSemiring R] : CommSemiring R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [Ring R] : Ring R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [CommRing R] : CommRing R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [Nontrivial R] : Nontrivial R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance {A} [Semiring R] [AddCommMonoid A] [Module R A] : Module R A⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance {A S} [Semiring R] [Semiring S] [AddCommMonoid A] [Module R A] [Module S A] [SMul R S]
[IsScalarTower R S A] : IsScalarTower R S A⟦X⟧ :=
Pi.isScalarTower
instance {A} [Semiring A] [CommSemiring R] [Algebra R A] : Algebra R A⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
end
section Semiring
variable (R) [Semiring R]
def coeff (n : ℕ) : R⟦X⟧ →ₗ[R] R :=
MvPowerSeries.coeff R (single () n)
#align power_series.coeff PowerSeries.coeff
def monomial (n : ℕ) : R →ₗ[R] R⟦X⟧ :=
MvPowerSeries.monomial R (single () n)
#align power_series.monomial PowerSeries.monomial
variable {R}
theorem coeff_def {s : Unit →₀ ℕ} {n : ℕ} (h : s () = n) : coeff R n = MvPowerSeries.coeff R s := by
erw [coeff, ← h, ← Finsupp.unique_single s]
#align power_series.coeff_def PowerSeries.coeff_def
@[ext]
theorem ext {φ ψ : R⟦X⟧} (h : ∀ n, coeff R n φ = coeff R n ψ) : φ = ψ :=
MvPowerSeries.ext fun n => by
rw [← coeff_def]
· apply h
rfl
#align power_series.ext PowerSeries.ext
theorem ext_iff {φ ψ : R⟦X⟧} : φ = ψ ↔ ∀ n, coeff R n φ = coeff R n ψ :=
⟨fun h n => congr_arg (coeff R n) h, ext⟩
#align power_series.ext_iff PowerSeries.ext_iff
instance [Subsingleton R] : Subsingleton R⟦X⟧ := by
simp only [subsingleton_iff, ext_iff]
exact fun _ _ _ ↦ (subsingleton_iff).mp (by infer_instance) _ _
def mk {R} (f : ℕ → R) : R⟦X⟧ := fun s => f (s ())
#align power_series.mk PowerSeries.mk
@[simp]
theorem coeff_mk (n : ℕ) (f : ℕ → R) : coeff R n (mk f) = f n :=
congr_arg f Finsupp.single_eq_same
#align power_series.coeff_mk PowerSeries.coeff_mk
theorem coeff_monomial (m n : ℕ) (a : R) : coeff R m (monomial R n a) = if m = n then a else 0 :=
calc
coeff R m (monomial R n a) = _ := MvPowerSeries.coeff_monomial _ _ _
_ = if m = n then a else 0 := by simp only [Finsupp.unique_single_eq_iff]
#align power_series.coeff_monomial PowerSeries.coeff_monomial
theorem monomial_eq_mk (n : ℕ) (a : R) : monomial R n a = mk fun m => if m = n then a else 0 :=
ext fun m => by rw [coeff_monomial, coeff_mk]
#align power_series.monomial_eq_mk PowerSeries.monomial_eq_mk
@[simp]
theorem coeff_monomial_same (n : ℕ) (a : R) : coeff R n (monomial R n a) = a :=
MvPowerSeries.coeff_monomial_same _ _
#align power_series.coeff_monomial_same PowerSeries.coeff_monomial_same
@[simp]
theorem coeff_comp_monomial (n : ℕ) : (coeff R n).comp (monomial R n) = LinearMap.id :=
LinearMap.ext <| coeff_monomial_same n
#align power_series.coeff_comp_monomial PowerSeries.coeff_comp_monomial
variable (R)
def constantCoeff : R⟦X⟧ →+* R :=
MvPowerSeries.constantCoeff Unit R
#align power_series.constant_coeff PowerSeries.constantCoeff
def C : R →+* R⟦X⟧ :=
MvPowerSeries.C Unit R
set_option linter.uppercaseLean3 false in
#align power_series.C PowerSeries.C
variable {R}
def X : R⟦X⟧ :=
MvPowerSeries.X ()
set_option linter.uppercaseLean3 false in
#align power_series.X PowerSeries.X
theorem commute_X (φ : R⟦X⟧) : Commute φ X :=
MvPowerSeries.commute_X _ _
set_option linter.uppercaseLean3 false in
#align power_series.commute_X PowerSeries.commute_X
@[simp]
theorem coeff_zero_eq_constantCoeff : ⇑(coeff R 0) = constantCoeff R := by
rw [coeff, Finsupp.single_zero]
rfl
#align power_series.coeff_zero_eq_constant_coeff PowerSeries.coeff_zero_eq_constantCoeff
theorem coeff_zero_eq_constantCoeff_apply (φ : R⟦X⟧) : coeff R 0 φ = constantCoeff R φ := by
rw [coeff_zero_eq_constantCoeff]
#align power_series.coeff_zero_eq_constant_coeff_apply PowerSeries.coeff_zero_eq_constantCoeff_apply
@[simp]
theorem monomial_zero_eq_C : ⇑(monomial R 0) = C R := by
-- This used to be `rw`, but we need `erw` after leanprover/lean4#2644
erw [monomial, Finsupp.single_zero, MvPowerSeries.monomial_zero_eq_C]
set_option linter.uppercaseLean3 false in
#align power_series.monomial_zero_eq_C PowerSeries.monomial_zero_eq_C
theorem monomial_zero_eq_C_apply (a : R) : monomial R 0 a = C R a := by simp
set_option linter.uppercaseLean3 false in
#align power_series.monomial_zero_eq_C_apply PowerSeries.monomial_zero_eq_C_apply
theorem coeff_C (n : ℕ) (a : R) : coeff R n (C R a : R⟦X⟧) = if n = 0 then a else 0 := by
rw [← monomial_zero_eq_C_apply, coeff_monomial]
set_option linter.uppercaseLean3 false in
#align power_series.coeff_C PowerSeries.coeff_C
@[simp]
theorem coeff_zero_C (a : R) : coeff R 0 (C R a) = a := by
rw [coeff_C, if_pos rfl]
set_option linter.uppercaseLean3 false in
#align power_series.coeff_zero_C PowerSeries.coeff_zero_C
theorem coeff_ne_zero_C {a : R} {n : ℕ} (h : n ≠ 0) : coeff R n (C R a) = 0 := by
rw [coeff_C, if_neg h]
@[simp]
theorem coeff_succ_C {a : R} {n : ℕ} : coeff R (n + 1) (C R a) = 0 :=
coeff_ne_zero_C n.succ_ne_zero
theorem C_injective : Function.Injective (C R) := by
intro a b H
have := (ext_iff (φ := C R a) (ψ := C R b)).mp H 0
rwa [coeff_zero_C, coeff_zero_C] at this
protected theorem subsingleton_iff : Subsingleton R⟦X⟧ ↔ Subsingleton R := by
refine ⟨fun h ↦ ?_, fun _ ↦ inferInstance⟩
rw [subsingleton_iff] at h ⊢
exact fun a b ↦ C_injective (h (C R a) (C R b))
theorem X_eq : (X : R⟦X⟧) = monomial R 1 1 :=
rfl
set_option linter.uppercaseLean3 false in
#align power_series.X_eq PowerSeries.X_eq
theorem coeff_X (n : ℕ) : coeff R n (X : R⟦X⟧) = if n = 1 then 1 else 0 := by
rw [X_eq, coeff_monomial]
set_option linter.uppercaseLean3 false in
#align power_series.coeff_X PowerSeries.coeff_X
@[simp]
theorem coeff_zero_X : coeff R 0 (X : R⟦X⟧) = 0 := by
-- This used to be `rw`, but we need `erw` after leanprover/lean4#2644
erw [coeff, Finsupp.single_zero, X, MvPowerSeries.coeff_zero_X]
set_option linter.uppercaseLean3 false in
#align power_series.coeff_zero_X PowerSeries.coeff_zero_X
@[simp]
theorem coeff_one_X : coeff R 1 (X : R⟦X⟧) = 1 := by rw [coeff_X, if_pos rfl]
set_option linter.uppercaseLean3 false in
#align power_series.coeff_one_X PowerSeries.coeff_one_X
@[simp]
theorem X_ne_zero [Nontrivial R] : (X : R⟦X⟧) ≠ 0 := fun H => by
simpa only [coeff_one_X, one_ne_zero, map_zero] using congr_arg (coeff R 1) H
set_option linter.uppercaseLean3 false in
#align power_series.X_ne_zero PowerSeries.X_ne_zero
theorem X_pow_eq (n : ℕ) : (X : R⟦X⟧) ^ n = monomial R n 1 :=
MvPowerSeries.X_pow_eq _ n
set_option linter.uppercaseLean3 false in
#align power_series.X_pow_eq PowerSeries.X_pow_eq
theorem coeff_X_pow (m n : ℕ) : coeff R m ((X : R⟦X⟧) ^ n) = if m = n then 1 else 0 := by
rw [X_pow_eq, coeff_monomial]
set_option linter.uppercaseLean3 false in
#align power_series.coeff_X_pow PowerSeries.coeff_X_pow
@[simp]
theorem coeff_X_pow_self (n : ℕ) : coeff R n ((X : R⟦X⟧) ^ n) = 1 := by
rw [coeff_X_pow, if_pos rfl]
set_option linter.uppercaseLean3 false in
#align power_series.coeff_X_pow_self PowerSeries.coeff_X_pow_self
@[simp]
theorem coeff_one (n : ℕ) : coeff R n (1 : R⟦X⟧) = if n = 0 then 1 else 0 :=
coeff_C n 1
#align power_series.coeff_one PowerSeries.coeff_one
theorem coeff_zero_one : coeff R 0 (1 : R⟦X⟧) = 1 :=
coeff_zero_C 1
#align power_series.coeff_zero_one PowerSeries.coeff_zero_one
theorem coeff_mul (n : ℕ) (φ ψ : R⟦X⟧) :
coeff R n (φ * ψ) = ∑ p ∈ antidiagonal n, coeff R p.1 φ * coeff R p.2 ψ := by
-- `rw` can't see that `PowerSeries = MvPowerSeries Unit`, so use `.trans`
refine (MvPowerSeries.coeff_mul _ φ ψ).trans ?_
rw [Finsupp.antidiagonal_single, Finset.sum_map]
rfl
#align power_series.coeff_mul PowerSeries.coeff_mul
@[simp]
theorem coeff_mul_C (n : ℕ) (φ : R⟦X⟧) (a : R) : coeff R n (φ * C R a) = coeff R n φ * a :=
MvPowerSeries.coeff_mul_C _ φ a
set_option linter.uppercaseLean3 false in
#align power_series.coeff_mul_C PowerSeries.coeff_mul_C
@[simp]
theorem coeff_C_mul (n : ℕ) (φ : R⟦X⟧) (a : R) : coeff R n (C R a * φ) = a * coeff R n φ :=
MvPowerSeries.coeff_C_mul _ φ a
set_option linter.uppercaseLean3 false in
#align power_series.coeff_C_mul PowerSeries.coeff_C_mul
@[simp]
theorem coeff_smul {S : Type*} [Semiring S] [Module R S] (n : ℕ) (φ : PowerSeries S) (a : R) :
coeff S n (a • φ) = a • coeff S n φ :=
rfl
#align power_series.coeff_smul PowerSeries.coeff_smul
@[simp]
theorem constantCoeff_smul {S : Type*} [Semiring S] [Module R S] (φ : PowerSeries S) (a : R) :
constantCoeff S (a • φ) = a • constantCoeff S φ :=
rfl
theorem smul_eq_C_mul (f : R⟦X⟧) (a : R) : a • f = C R a * f := by
ext
simp
set_option linter.uppercaseLean3 false in
#align power_series.smul_eq_C_mul PowerSeries.smul_eq_C_mul
@[simp]
theorem coeff_succ_mul_X (n : ℕ) (φ : R⟦X⟧) : coeff R (n + 1) (φ * X) = coeff R n φ := by
simp only [coeff, Finsupp.single_add]
convert φ.coeff_add_mul_monomial (single () n) (single () 1) _
rw [mul_one]; rfl
set_option linter.uppercaseLean3 false in
#align power_series.coeff_succ_mul_X PowerSeries.coeff_succ_mul_X
@[simp]
theorem coeff_succ_X_mul (n : ℕ) (φ : R⟦X⟧) : coeff R (n + 1) (X * φ) = coeff R n φ := by
simp only [coeff, Finsupp.single_add, add_comm n 1]
convert φ.coeff_add_monomial_mul (single () 1) (single () n) _
rw [one_mul]; rfl
set_option linter.uppercaseLean3 false in
#align power_series.coeff_succ_X_mul PowerSeries.coeff_succ_X_mul
@[simp]
theorem constantCoeff_C (a : R) : constantCoeff R (C R a) = a :=
rfl
set_option linter.uppercaseLean3 false in
#align power_series.constant_coeff_C PowerSeries.constantCoeff_C
@[simp]
theorem constantCoeff_comp_C : (constantCoeff R).comp (C R) = RingHom.id R :=
rfl
set_option linter.uppercaseLean3 false in
#align power_series.constant_coeff_comp_C PowerSeries.constantCoeff_comp_C
-- Porting note (#10618): simp can prove this.
-- @[simp]
theorem constantCoeff_zero : constantCoeff R 0 = 0 :=
rfl
#align power_series.constant_coeff_zero PowerSeries.constantCoeff_zero
-- Porting note (#10618): simp can prove this.
-- @[simp]
theorem constantCoeff_one : constantCoeff R 1 = 1 :=
rfl
#align power_series.constant_coeff_one PowerSeries.constantCoeff_one
@[simp]
theorem constantCoeff_X : constantCoeff R X = 0 :=
MvPowerSeries.coeff_zero_X _
set_option linter.uppercaseLean3 false in
#align power_series.constant_coeff_X PowerSeries.constantCoeff_X
@[simp]
theorem constantCoeff_mk {f : ℕ → R} : constantCoeff R (mk f) = f 0 := rfl
theorem coeff_zero_mul_X (φ : R⟦X⟧) : coeff R 0 (φ * X) = 0 := by simp
set_option linter.uppercaseLean3 false in
#align power_series.coeff_zero_mul_X PowerSeries.coeff_zero_mul_X
theorem coeff_zero_X_mul (φ : R⟦X⟧) : coeff R 0 (X * φ) = 0 := by simp
set_option linter.uppercaseLean3 false in
#align power_series.coeff_zero_X_mul PowerSeries.coeff_zero_X_mul
theorem constantCoeff_surj : Function.Surjective (constantCoeff R) :=
fun r => ⟨(C R) r, constantCoeff_C r⟩
-- The following section duplicates the API of `Data.Polynomial.Coeff` and should attempt to keep
-- up to date with that
section
theorem coeff_C_mul_X_pow (x : R) (k n : ℕ) :
coeff R n (C R x * X ^ k : R⟦X⟧) = if n = k then x else 0 := by
simp [X_pow_eq, coeff_monomial]
set_option linter.uppercaseLean3 false in
#align power_series.coeff_C_mul_X_pow PowerSeries.coeff_C_mul_X_pow
@[simp]
theorem coeff_mul_X_pow (p : R⟦X⟧) (n d : ℕ) :
coeff R (d + n) (p * X ^ n) = coeff R d p := by
rw [coeff_mul, Finset.sum_eq_single (d, n), coeff_X_pow, if_pos rfl, mul_one]
· rintro ⟨i, j⟩ h1 h2
rw [coeff_X_pow, if_neg, mul_zero]
rintro rfl
apply h2
rw [mem_antidiagonal, add_right_cancel_iff] at h1
subst h1
rfl
· exact fun h1 => (h1 (mem_antidiagonal.2 rfl)).elim
set_option linter.uppercaseLean3 false in
#align power_series.coeff_mul_X_pow PowerSeries.coeff_mul_X_pow
@[simp]
theorem coeff_X_pow_mul (p : R⟦X⟧) (n d : ℕ) :
coeff R (d + n) (X ^ n * p) = coeff R d p := by
rw [coeff_mul, Finset.sum_eq_single (n, d), coeff_X_pow, if_pos rfl, one_mul]
· rintro ⟨i, j⟩ h1 h2
rw [coeff_X_pow, if_neg, zero_mul]
rintro rfl
apply h2
rw [mem_antidiagonal, add_comm, add_right_cancel_iff] at h1
subst h1
rfl
· rw [add_comm]
exact fun h1 => (h1 (mem_antidiagonal.2 rfl)).elim
set_option linter.uppercaseLean3 false in
#align power_series.coeff_X_pow_mul PowerSeries.coeff_X_pow_mul
theorem coeff_mul_X_pow' (p : R⟦X⟧) (n d : ℕ) :
coeff R d (p * X ^ n) = ite (n ≤ d) (coeff R (d - n) p) 0 := by
split_ifs with h
· rw [← tsub_add_cancel_of_le h, coeff_mul_X_pow, add_tsub_cancel_right]
· refine (coeff_mul _ _ _).trans (Finset.sum_eq_zero fun x hx => ?_)
rw [coeff_X_pow, if_neg, mul_zero]
exact ((le_of_add_le_right (mem_antidiagonal.mp hx).le).trans_lt <| not_le.mp h).ne
set_option linter.uppercaseLean3 false in
#align power_series.coeff_mul_X_pow' PowerSeries.coeff_mul_X_pow'
theorem coeff_X_pow_mul' (p : R⟦X⟧) (n d : ℕ) :
coeff R d (X ^ n * p) = ite (n ≤ d) (coeff R (d - n) p) 0 := by
split_ifs with h
· rw [← tsub_add_cancel_of_le h, coeff_X_pow_mul]
simp
· refine (coeff_mul _ _ _).trans (Finset.sum_eq_zero fun x hx => ?_)
rw [coeff_X_pow, if_neg, zero_mul]
have := mem_antidiagonal.mp hx
rw [add_comm] at this
exact ((le_of_add_le_right this.le).trans_lt <| not_le.mp h).ne
set_option linter.uppercaseLean3 false in
#align power_series.coeff_X_pow_mul' PowerSeries.coeff_X_pow_mul'
end
theorem isUnit_constantCoeff (φ : R⟦X⟧) (h : IsUnit φ) : IsUnit (constantCoeff R φ) :=
MvPowerSeries.isUnit_constantCoeff φ h
#align power_series.is_unit_constant_coeff PowerSeries.isUnit_constantCoeff
theorem eq_shift_mul_X_add_const (φ : R⟦X⟧) :
φ = (mk fun p => coeff R (p + 1) φ) * X + C R (constantCoeff R φ) := by
ext (_ | n)
· simp only [Nat.zero_eq, coeff_zero_eq_constantCoeff, map_add, map_mul, constantCoeff_X,
mul_zero, coeff_zero_C, zero_add]
· simp only [coeff_succ_mul_X, coeff_mk, LinearMap.map_add, coeff_C, n.succ_ne_zero, sub_zero,
if_false, add_zero]
set_option linter.uppercaseLean3 false in
#align power_series.eq_shift_mul_X_add_const PowerSeries.eq_shift_mul_X_add_const
theorem eq_X_mul_shift_add_const (φ : R⟦X⟧) :
φ = (X * mk fun p => coeff R (p + 1) φ) + C R (constantCoeff R φ) := by
ext (_ | n)
· simp only [Nat.zero_eq, coeff_zero_eq_constantCoeff, map_add, map_mul, constantCoeff_X,
zero_mul, coeff_zero_C, zero_add]
· simp only [coeff_succ_X_mul, coeff_mk, LinearMap.map_add, coeff_C, n.succ_ne_zero, sub_zero,
if_false, add_zero]
set_option linter.uppercaseLean3 false in
#align power_series.eq_X_mul_shift_add_const PowerSeries.eq_X_mul_shift_add_const
section CommSemiring
open Finset.HasAntidiagonal Finset
variable {R : Type*} [CommSemiring R] {ι : Type*} [DecidableEq ι]
| Mathlib/RingTheory/PowerSeries/Basic.lean | 663 | 674 | theorem coeff_prod (f : ι → PowerSeries R) (d : ℕ) (s : Finset ι) :
coeff R d (∏ j ∈ s, f j) = ∑ l ∈ finsuppAntidiag s d, ∏ i ∈ s, coeff R (l i) (f i) := by |
simp only [coeff]
convert MvPowerSeries.coeff_prod _ _ _
rw [← AddEquiv.finsuppUnique_symm d, ← mapRange_finsuppAntidiag_eq, sum_map, sum_congr rfl]
intro x _
apply prod_congr rfl
intro i _
congr 2
simp only [AddEquiv.toEquiv_eq_coe, Finsupp.mapRange.addEquiv_toEquiv, AddEquiv.toEquiv_symm,
Equiv.coe_toEmbedding, Finsupp.mapRange.equiv_apply, AddEquiv.coe_toEquiv_symm,
Finsupp.mapRange_apply, AddEquiv.finsuppUnique_symm]
|
import Mathlib.Geometry.Euclidean.Sphere.Basic
#align_import geometry.euclidean.sphere.second_inter from "leanprover-community/mathlib"@"46b633fd842bef9469441c0209906f6dddd2b4f5"
noncomputable section
open RealInnerProductSpace
namespace EuclideanGeometry
variable {V : Type*} {P : Type*} [NormedAddCommGroup V] [InnerProductSpace ℝ V] [MetricSpace P]
[NormedAddTorsor V P]
def Sphere.secondInter (s : Sphere P) (p : P) (v : V) : P :=
(-2 * ⟪v, p -ᵥ s.center⟫ / ⟪v, v⟫) • v +ᵥ p
#align euclidean_geometry.sphere.second_inter EuclideanGeometry.Sphere.secondInter
@[simp]
theorem Sphere.secondInter_dist (s : Sphere P) (p : P) (v : V) :
dist (s.secondInter p v) s.center = dist p s.center := by
rw [Sphere.secondInter]
by_cases hv : v = 0; · simp [hv]
rw [dist_smul_vadd_eq_dist _ _ hv]
exact Or.inr rfl
#align euclidean_geometry.sphere.second_inter_dist EuclideanGeometry.Sphere.secondInter_dist
@[simp]
theorem Sphere.secondInter_mem {s : Sphere P} {p : P} (v : V) : s.secondInter p v ∈ s ↔ p ∈ s := by
simp_rw [mem_sphere, Sphere.secondInter_dist]
#align euclidean_geometry.sphere.second_inter_mem EuclideanGeometry.Sphere.secondInter_mem
variable (V)
@[simp]
theorem Sphere.secondInter_zero (s : Sphere P) (p : P) : s.secondInter p (0 : V) = p := by
simp [Sphere.secondInter]
#align euclidean_geometry.sphere.second_inter_zero EuclideanGeometry.Sphere.secondInter_zero
variable {V}
theorem Sphere.secondInter_eq_self_iff {s : Sphere P} {p : P} {v : V} :
s.secondInter p v = p ↔ ⟪v, p -ᵥ s.center⟫ = 0 := by
refine ⟨fun hp => ?_, fun hp => ?_⟩
· by_cases hv : v = 0
· simp [hv]
rwa [Sphere.secondInter, eq_comm, eq_vadd_iff_vsub_eq, vsub_self, eq_comm, smul_eq_zero,
or_iff_left hv, div_eq_zero_iff, inner_self_eq_zero, or_iff_left hv, mul_eq_zero,
or_iff_right (by norm_num : (-2 : ℝ) ≠ 0)] at hp
· rw [Sphere.secondInter, hp, mul_zero, zero_div, zero_smul, zero_vadd]
#align euclidean_geometry.sphere.second_inter_eq_self_iff EuclideanGeometry.Sphere.secondInter_eq_self_iff
theorem Sphere.eq_or_eq_secondInter_of_mem_mk'_span_singleton_iff_mem {s : Sphere P} {p : P}
(hp : p ∈ s) {v : V} {p' : P} (hp' : p' ∈ AffineSubspace.mk' p (ℝ ∙ v)) :
p' = p ∨ p' = s.secondInter p v ↔ p' ∈ s := by
refine ⟨fun h => ?_, fun h => ?_⟩
· rcases h with (h | h)
· rwa [h]
· rwa [h, Sphere.secondInter_mem]
· rw [AffineSubspace.mem_mk'_iff_vsub_mem, Submodule.mem_span_singleton] at hp'
rcases hp' with ⟨r, hr⟩
rw [eq_comm, ← eq_vadd_iff_vsub_eq] at hr
subst hr
by_cases hv : v = 0
· simp [hv]
rw [Sphere.secondInter]
rw [mem_sphere] at h hp
rw [← hp, dist_smul_vadd_eq_dist _ _ hv] at h
rcases h with (h | h) <;> simp [h]
#align euclidean_geometry.sphere.eq_or_eq_second_inter_of_mem_mk'_span_singleton_iff_mem EuclideanGeometry.Sphere.eq_or_eq_secondInter_of_mem_mk'_span_singleton_iff_mem
@[simp]
theorem Sphere.secondInter_smul (s : Sphere P) (p : P) (v : V) {r : ℝ} (hr : r ≠ 0) :
s.secondInter p (r • v) = s.secondInter p v := by
simp_rw [Sphere.secondInter, real_inner_smul_left, inner_smul_right, smul_smul,
div_mul_eq_div_div]
rw [mul_comm, ← mul_div_assoc, ← mul_div_assoc, mul_div_cancel_left₀ _ hr, mul_comm, mul_assoc,
mul_div_cancel_left₀ _ hr, mul_comm]
#align euclidean_geometry.sphere.second_inter_smul EuclideanGeometry.Sphere.secondInter_smul
@[simp]
| Mathlib/Geometry/Euclidean/Sphere/SecondInter.lean | 113 | 115 | theorem Sphere.secondInter_neg (s : Sphere P) (p : P) (v : V) :
s.secondInter p (-v) = s.secondInter p v := by |
rw [← neg_one_smul ℝ v, s.secondInter_smul p v (by norm_num : (-1 : ℝ) ≠ 0)]
|
import Mathlib.LinearAlgebra.Matrix.Charpoly.Coeff
import Mathlib.LinearAlgebra.Matrix.ToLin
#align_import linear_algebra.matrix.charpoly.linear_map from "leanprover-community/mathlib"@"62c0a4ef1441edb463095ea02a06e87f3dfe135c"
variable {ι : Type*} [Fintype ι]
variable {M : Type*} [AddCommGroup M] (R : Type*) [CommRing R] [Module R M] (I : Ideal R)
variable (b : ι → M) (hb : Submodule.span R (Set.range b) = ⊤)
open Polynomial Matrix
def PiToModule.fromMatrix [DecidableEq ι] : Matrix ι ι R →ₗ[R] (ι → R) →ₗ[R] M :=
(LinearMap.llcomp R _ _ _ (Fintype.total R R b)).comp algEquivMatrix'.symm.toLinearMap
#align pi_to_module.from_matrix PiToModule.fromMatrix
theorem PiToModule.fromMatrix_apply [DecidableEq ι] (A : Matrix ι ι R) (w : ι → R) :
PiToModule.fromMatrix R b A w = Fintype.total R R b (A *ᵥ w) :=
rfl
#align pi_to_module.from_matrix_apply PiToModule.fromMatrix_apply
theorem PiToModule.fromMatrix_apply_single_one [DecidableEq ι] (A : Matrix ι ι R) (j : ι) :
PiToModule.fromMatrix R b A (Pi.single j 1) = ∑ i : ι, A i j • b i := by
rw [PiToModule.fromMatrix_apply, Fintype.total_apply, Matrix.mulVec_single]
simp_rw [mul_one]
#align pi_to_module.from_matrix_apply_single_one PiToModule.fromMatrix_apply_single_one
def PiToModule.fromEnd : Module.End R M →ₗ[R] (ι → R) →ₗ[R] M :=
LinearMap.lcomp _ _ (Fintype.total R R b)
#align pi_to_module.from_End PiToModule.fromEnd
theorem PiToModule.fromEnd_apply (f : Module.End R M) (w : ι → R) :
PiToModule.fromEnd R b f w = f (Fintype.total R R b w) :=
rfl
#align pi_to_module.from_End_apply PiToModule.fromEnd_apply
theorem PiToModule.fromEnd_apply_single_one [DecidableEq ι] (f : Module.End R M) (i : ι) :
PiToModule.fromEnd R b f (Pi.single i 1) = f (b i) := by
rw [PiToModule.fromEnd_apply]
congr
convert Fintype.total_apply_single (S := R) R b i (1 : R)
rw [one_smul]
#align pi_to_module.from_End_apply_single_one PiToModule.fromEnd_apply_single_one
theorem PiToModule.fromEnd_injective (hb : Submodule.span R (Set.range b) = ⊤) :
Function.Injective (PiToModule.fromEnd R b) := by
intro x y e
ext m
obtain ⟨m, rfl⟩ : m ∈ LinearMap.range (Fintype.total R R b) := by
rw [(Fintype.range_total R b).trans hb]
exact Submodule.mem_top
exact (LinearMap.congr_fun e m : _)
#align pi_to_module.from_End_injective PiToModule.fromEnd_injective
section
variable {R} [DecidableEq ι]
def Matrix.Represents (A : Matrix ι ι R) (f : Module.End R M) : Prop :=
PiToModule.fromMatrix R b A = PiToModule.fromEnd R b f
#align matrix.represents Matrix.Represents
variable {b}
theorem Matrix.Represents.congr_fun {A : Matrix ι ι R} {f : Module.End R M} (h : A.Represents b f)
(x) : Fintype.total R R b (A *ᵥ x) = f (Fintype.total R R b x) :=
LinearMap.congr_fun h x
#align matrix.represents.congr_fun Matrix.Represents.congr_fun
theorem Matrix.represents_iff {A : Matrix ι ι R} {f : Module.End R M} :
A.Represents b f ↔ ∀ x, Fintype.total R R b (A *ᵥ x) = f (Fintype.total R R b x) :=
⟨fun e x => e.congr_fun x, fun H => LinearMap.ext fun x => H x⟩
#align matrix.represents_iff Matrix.represents_iff
theorem Matrix.represents_iff' {A : Matrix ι ι R} {f : Module.End R M} :
A.Represents b f ↔ ∀ j, ∑ i : ι, A i j • b i = f (b j) := by
constructor
· intro h i
have := LinearMap.congr_fun h (Pi.single i 1)
rwa [PiToModule.fromEnd_apply_single_one, PiToModule.fromMatrix_apply_single_one] at this
· intro h
-- Porting note: was `ext`
refine LinearMap.pi_ext' (fun i => LinearMap.ext_ring ?_)
simp_rw [LinearMap.comp_apply, LinearMap.coe_single, PiToModule.fromEnd_apply_single_one,
PiToModule.fromMatrix_apply_single_one]
apply h
#align matrix.represents_iff' Matrix.represents_iff'
theorem Matrix.Represents.mul {A A' : Matrix ι ι R} {f f' : Module.End R M} (h : A.Represents b f)
(h' : Matrix.Represents b A' f') : (A * A').Represents b (f * f') := by
delta Matrix.Represents PiToModule.fromMatrix
rw [LinearMap.comp_apply, AlgEquiv.toLinearMap_apply, _root_.map_mul]
ext
dsimp [PiToModule.fromEnd]
rw [← h'.congr_fun, ← h.congr_fun]
rfl
#align matrix.represents.mul Matrix.Represents.mul
theorem Matrix.Represents.one : (1 : Matrix ι ι R).Represents b 1 := by
delta Matrix.Represents PiToModule.fromMatrix
rw [LinearMap.comp_apply, AlgEquiv.toLinearMap_apply, _root_.map_one]
ext
rfl
#align matrix.represents.one Matrix.Represents.one
theorem Matrix.Represents.add {A A' : Matrix ι ι R} {f f' : Module.End R M} (h : A.Represents b f)
(h' : Matrix.Represents b A' f') : (A + A').Represents b (f + f') := by
delta Matrix.Represents at h h' ⊢; rw [map_add, map_add, h, h']
#align matrix.represents.add Matrix.Represents.add
theorem Matrix.Represents.zero : (0 : Matrix ι ι R).Represents b 0 := by
delta Matrix.Represents
rw [map_zero, map_zero]
#align matrix.represents.zero Matrix.Represents.zero
theorem Matrix.Represents.smul {A : Matrix ι ι R} {f : Module.End R M} (h : A.Represents b f)
(r : R) : (r • A).Represents b (r • f) := by
delta Matrix.Represents at h ⊢
rw [_root_.map_smul, _root_.map_smul, h]
#align matrix.represents.smul Matrix.Represents.smul
theorem Matrix.Represents.algebraMap (r : R) :
(algebraMap _ (Matrix ι ι R) r).Represents b (algebraMap _ (Module.End R M) r) := by
simpa only [Algebra.algebraMap_eq_smul_one] using Matrix.Represents.one.smul r
theorem Matrix.Represents.eq {A : Matrix ι ι R} {f f' : Module.End R M} (h : A.Represents b f)
(h' : A.Represents b f') : f = f' :=
PiToModule.fromEnd_injective R b hb (h.symm.trans h')
#align matrix.represents.eq Matrix.Represents.eq
variable (b R)
def Matrix.isRepresentation : Subalgebra R (Matrix ι ι R) where
carrier := { A | ∃ f : Module.End R M, A.Represents b f }
mul_mem' := fun ⟨f₁, e₁⟩ ⟨f₂, e₂⟩ => ⟨f₁ * f₂, e₁.mul e₂⟩
one_mem' := ⟨1, Matrix.Represents.one⟩
add_mem' := fun ⟨f₁, e₁⟩ ⟨f₂, e₂⟩ => ⟨f₁ + f₂, e₁.add e₂⟩
zero_mem' := ⟨0, Matrix.Represents.zero⟩
algebraMap_mem' r := ⟨algebraMap _ _ r, .algebraMap _⟩
#align matrix.is_representation Matrix.isRepresentation
noncomputable def Matrix.isRepresentation.toEnd :
Matrix.isRepresentation R b →ₐ[R] Module.End R M where
toFun A := A.2.choose
map_one' := (1 : Matrix.isRepresentation R b).2.choose_spec.eq hb Matrix.Represents.one
map_mul' A₁ A₂ := (A₁ * A₂).2.choose_spec.eq hb (A₁.2.choose_spec.mul A₂.2.choose_spec)
map_zero' := (0 : Matrix.isRepresentation R b).2.choose_spec.eq hb Matrix.Represents.zero
map_add' A₁ A₂ := (A₁ + A₂).2.choose_spec.eq hb (A₁.2.choose_spec.add A₂.2.choose_spec)
commutes' r :=
(algebraMap _ (Matrix.isRepresentation R b) r).2.choose_spec.eq hb (.algebraMap r)
#align matrix.is_representation.to_End Matrix.isRepresentation.toEnd
theorem Matrix.isRepresentation.toEnd_represents (A : Matrix.isRepresentation R b) :
(A : Matrix ι ι R).Represents b (Matrix.isRepresentation.toEnd R b hb A) :=
A.2.choose_spec
#align matrix.is_representation.to_End_represents Matrix.isRepresentation.toEnd_represents
theorem Matrix.isRepresentation.eq_toEnd_of_represents (A : Matrix.isRepresentation R b)
{f : Module.End R M} (h : (A : Matrix ι ι R).Represents b f) :
Matrix.isRepresentation.toEnd R b hb A = f :=
A.2.choose_spec.eq hb h
#align matrix.is_representation.eq_to_End_of_represents Matrix.isRepresentation.eq_toEnd_of_represents
| Mathlib/LinearAlgebra/Matrix/Charpoly/LinearMap.lean | 192 | 208 | theorem Matrix.isRepresentation.toEnd_exists_mem_ideal (f : Module.End R M) (I : Ideal R)
(hI : LinearMap.range f ≤ I • ⊤) :
∃ M, Matrix.isRepresentation.toEnd R b hb M = f ∧ ∀ i j, M.1 i j ∈ I := by |
have : ∀ x, f x ∈ LinearMap.range (Ideal.finsuppTotal ι M I b) := by
rw [Ideal.range_finsuppTotal, hb]
exact fun x => hI (LinearMap.mem_range_self f x)
choose bM' hbM' using this
let A : Matrix ι ι R := fun i j => bM' (b j) i
have : A.Represents b f := by
rw [Matrix.represents_iff']
dsimp [A]
intro j
specialize hbM' (b j)
rwa [Ideal.finsuppTotal_apply_eq_of_fintype] at hbM'
exact
⟨⟨A, f, this⟩, Matrix.isRepresentation.eq_toEnd_of_represents R b hb ⟨A, f, this⟩ this,
fun i j => (bM' (b j) i).prop⟩
|
import Mathlib.Algebra.BigOperators.Fin
import Mathlib.LinearAlgebra.Finsupp
import Mathlib.LinearAlgebra.Prod
import Mathlib.SetTheory.Cardinal.Basic
import Mathlib.Tactic.FinCases
import Mathlib.Tactic.LinearCombination
import Mathlib.Lean.Expr.ExtraRecognizers
import Mathlib.Data.Set.Subsingleton
#align_import linear_algebra.linear_independent from "leanprover-community/mathlib"@"9d684a893c52e1d6692a504a118bfccbae04feeb"
noncomputable section
open Function Set Submodule
open Cardinal
universe u' u
variable {ι : Type u'} {ι' : Type*} {R : Type*} {K : Type*}
variable {M : Type*} {M' M'' : Type*} {V : Type u} {V' : Type*}
section Module
variable {v : ι → M}
variable [Semiring R] [AddCommMonoid M] [AddCommMonoid M'] [AddCommMonoid M'']
variable [Module R M] [Module R M'] [Module R M'']
variable {a b : R} {x y : M}
variable (R) (v)
def LinearIndependent : Prop :=
LinearMap.ker (Finsupp.total ι M R v) = ⊥
#align linear_independent LinearIndependent
open Lean PrettyPrinter.Delaborator SubExpr in
@[delab app.LinearIndependent]
def delabLinearIndependent : Delab :=
whenPPOption getPPNotation <|
whenNotPPOption getPPAnalysisSkip <|
withOptionAtCurrPos `pp.analysis.skip true do
let e ← getExpr
guard <| e.isAppOfArity ``LinearIndependent 7
let some _ := (e.getArg! 0).coeTypeSet? | failure
let optionsPerPos ← if (e.getArg! 3).isLambda then
withNaryArg 3 do return (← read).optionsPerPos.setBool (← getPos) pp.funBinderTypes.name true
else
withNaryArg 0 do return (← read).optionsPerPos.setBool (← getPos) `pp.analysis.namedArg true
withTheReader Context ({· with optionsPerPos}) delab
variable {R} {v}
theorem linearIndependent_iff :
LinearIndependent R v ↔ ∀ l, Finsupp.total ι M R v l = 0 → l = 0 := by
simp [LinearIndependent, LinearMap.ker_eq_bot']
#align linear_independent_iff linearIndependent_iff
theorem linearIndependent_iff' :
LinearIndependent R v ↔
∀ s : Finset ι, ∀ g : ι → R, ∑ i ∈ s, g i • v i = 0 → ∀ i ∈ s, g i = 0 :=
linearIndependent_iff.trans
⟨fun hf s g hg i his =>
have h :=
hf (∑ i ∈ s, Finsupp.single i (g i)) <| by
simpa only [map_sum, Finsupp.total_single] using hg
calc
g i = (Finsupp.lapply i : (ι →₀ R) →ₗ[R] R) (Finsupp.single i (g i)) := by
{ rw [Finsupp.lapply_apply, Finsupp.single_eq_same] }
_ = ∑ j ∈ s, (Finsupp.lapply i : (ι →₀ R) →ₗ[R] R) (Finsupp.single j (g j)) :=
Eq.symm <|
Finset.sum_eq_single i
(fun j _hjs hji => by rw [Finsupp.lapply_apply, Finsupp.single_eq_of_ne hji])
fun hnis => hnis.elim his
_ = (∑ j ∈ s, Finsupp.single j (g j)) i := (map_sum ..).symm
_ = 0 := DFunLike.ext_iff.1 h i,
fun hf l hl =>
Finsupp.ext fun i =>
_root_.by_contradiction fun hni => hni <| hf _ _ hl _ <| Finsupp.mem_support_iff.2 hni⟩
#align linear_independent_iff' linearIndependent_iff'
theorem linearIndependent_iff'' :
LinearIndependent R v ↔
∀ (s : Finset ι) (g : ι → R), (∀ i ∉ s, g i = 0) →
∑ i ∈ s, g i • v i = 0 → ∀ i, g i = 0 := by
classical
exact linearIndependent_iff'.trans
⟨fun H s g hg hv i => if his : i ∈ s then H s g hv i his else hg i his, fun H s g hg i hi => by
convert
H s (fun j => if j ∈ s then g j else 0) (fun j hj => if_neg hj)
(by simp_rw [ite_smul, zero_smul, Finset.sum_extend_by_zero, hg]) i
exact (if_pos hi).symm⟩
#align linear_independent_iff'' linearIndependent_iff''
theorem not_linearIndependent_iff :
¬LinearIndependent R v ↔
∃ s : Finset ι, ∃ g : ι → R, ∑ i ∈ s, g i • v i = 0 ∧ ∃ i ∈ s, g i ≠ 0 := by
rw [linearIndependent_iff']
simp only [exists_prop, not_forall]
#align not_linear_independent_iff not_linearIndependent_iff
theorem Fintype.linearIndependent_iff [Fintype ι] :
LinearIndependent R v ↔ ∀ g : ι → R, ∑ i, g i • v i = 0 → ∀ i, g i = 0 := by
refine
⟨fun H g => by simpa using linearIndependent_iff'.1 H Finset.univ g, fun H =>
linearIndependent_iff''.2 fun s g hg hs i => H _ ?_ _⟩
rw [← hs]
refine (Finset.sum_subset (Finset.subset_univ _) fun i _ hi => ?_).symm
rw [hg i hi, zero_smul]
#align fintype.linear_independent_iff Fintype.linearIndependent_iff
theorem Fintype.linearIndependent_iff' [Fintype ι] [DecidableEq ι] :
LinearIndependent R v ↔
LinearMap.ker (LinearMap.lsum R (fun _ ↦ R) ℕ fun i ↦ LinearMap.id.smulRight (v i)) = ⊥ := by
simp [Fintype.linearIndependent_iff, LinearMap.ker_eq_bot', funext_iff]
#align fintype.linear_independent_iff' Fintype.linearIndependent_iff'
theorem Fintype.not_linearIndependent_iff [Fintype ι] :
¬LinearIndependent R v ↔ ∃ g : ι → R, ∑ i, g i • v i = 0 ∧ ∃ i, g i ≠ 0 := by
simpa using not_iff_not.2 Fintype.linearIndependent_iff
#align fintype.not_linear_independent_iff Fintype.not_linearIndependent_iff
theorem linearIndependent_empty_type [IsEmpty ι] : LinearIndependent R v :=
linearIndependent_iff.mpr fun v _hv => Subsingleton.elim v 0
#align linear_independent_empty_type linearIndependent_empty_type
theorem LinearIndependent.ne_zero [Nontrivial R] (i : ι) (hv : LinearIndependent R v) : v i ≠ 0 :=
fun h =>
zero_ne_one' R <|
Eq.symm
(by
suffices (Finsupp.single i 1 : ι →₀ R) i = 0 by simpa
rw [linearIndependent_iff.1 hv (Finsupp.single i 1)]
· simp
· simp [h])
#align linear_independent.ne_zero LinearIndependent.ne_zero
lemma LinearIndependent.eq_zero_of_pair {x y : M} (h : LinearIndependent R ![x, y])
{s t : R} (h' : s • x + t • y = 0) : s = 0 ∧ t = 0 := by
have := linearIndependent_iff'.1 h Finset.univ ![s, t]
simp only [Fin.sum_univ_two, Matrix.cons_val_zero, Matrix.cons_val_one, Matrix.head_cons, h',
Finset.mem_univ, forall_true_left] at this
exact ⟨this 0, this 1⟩
lemma LinearIndependent.pair_iff {x y : M} :
LinearIndependent R ![x, y] ↔ ∀ (s t : R), s • x + t • y = 0 → s = 0 ∧ t = 0 := by
refine ⟨fun h s t hst ↦ h.eq_zero_of_pair hst, fun h ↦ ?_⟩
apply Fintype.linearIndependent_iff.2
intro g hg
simp only [Fin.sum_univ_two, Matrix.cons_val_zero, Matrix.cons_val_one, Matrix.head_cons] at hg
intro i
fin_cases i
exacts [(h _ _ hg).1, (h _ _ hg).2]
theorem LinearIndependent.comp (h : LinearIndependent R v) (f : ι' → ι) (hf : Injective f) :
LinearIndependent R (v ∘ f) := by
rw [linearIndependent_iff, Finsupp.total_comp]
intro l hl
have h_map_domain : ∀ x, (Finsupp.mapDomain f l) (f x) = 0 := by
rw [linearIndependent_iff.1 h (Finsupp.mapDomain f l) hl]; simp
ext x
convert h_map_domain x
rw [Finsupp.mapDomain_apply hf]
#align linear_independent.comp LinearIndependent.comp
theorem linearIndependent_iff_finset_linearIndependent :
LinearIndependent R v ↔ ∀ (s : Finset ι), LinearIndependent R (v ∘ (Subtype.val : s → ι)) :=
⟨fun H _ ↦ H.comp _ Subtype.val_injective, fun H ↦ linearIndependent_iff'.2 fun s g hg i hi ↦
Fintype.linearIndependent_iff.1 (H s) (g ∘ Subtype.val)
(hg ▸ Finset.sum_attach s fun j ↦ g j • v j) ⟨i, hi⟩⟩
theorem LinearIndependent.coe_range (i : LinearIndependent R v) :
LinearIndependent R ((↑) : range v → M) := by simpa using i.comp _ (rangeSplitting_injective v)
#align linear_independent.coe_range LinearIndependent.coe_range
theorem LinearIndependent.map (hv : LinearIndependent R v) {f : M →ₗ[R] M'}
(hf_inj : Disjoint (span R (range v)) (LinearMap.ker f)) : LinearIndependent R (f ∘ v) := by
rw [disjoint_iff_inf_le, ← Set.image_univ, Finsupp.span_image_eq_map_total,
map_inf_eq_map_inf_comap, map_le_iff_le_comap, comap_bot, Finsupp.supported_univ, top_inf_eq]
at hf_inj
unfold LinearIndependent at hv ⊢
rw [hv, le_bot_iff] at hf_inj
haveI : Inhabited M := ⟨0⟩
rw [Finsupp.total_comp, Finsupp.lmapDomain_total _ _ f, LinearMap.ker_comp,
hf_inj]
exact fun _ => rfl
#align linear_independent.map LinearIndependent.map
theorem Submodule.range_ker_disjoint {f : M →ₗ[R] M'}
(hv : LinearIndependent R (f ∘ v)) :
Disjoint (span R (range v)) (LinearMap.ker f) := by
rw [LinearIndependent, Finsupp.total_comp, Finsupp.lmapDomain_total R _ f (fun _ ↦ rfl),
LinearMap.ker_comp] at hv
rw [disjoint_iff_inf_le, ← Set.image_univ, Finsupp.span_image_eq_map_total,
map_inf_eq_map_inf_comap, hv, inf_bot_eq, map_bot]
theorem LinearIndependent.map' (hv : LinearIndependent R v) (f : M →ₗ[R] M')
(hf_inj : LinearMap.ker f = ⊥) : LinearIndependent R (f ∘ v) :=
hv.map <| by simp [hf_inj]
#align linear_independent.map' LinearIndependent.map'
theorem LinearIndependent.map_of_injective_injective {R' : Type*} {M' : Type*}
[Semiring R'] [AddCommMonoid M'] [Module R' M'] (hv : LinearIndependent R v)
(i : R' → R) (j : M →+ M') (hi : ∀ r, i r = 0 → r = 0) (hj : ∀ m, j m = 0 → m = 0)
(hc : ∀ (r : R') (m : M), j (i r • m) = r • j m) : LinearIndependent R' (j ∘ v) := by
rw [linearIndependent_iff'] at hv ⊢
intro S r' H s hs
simp_rw [comp_apply, ← hc, ← map_sum] at H
exact hi _ <| hv _ _ (hj _ H) s hs
theorem LinearIndependent.map_of_surjective_injective {R' : Type*} {M' : Type*}
[Semiring R'] [AddCommMonoid M'] [Module R' M'] (hv : LinearIndependent R v)
(i : ZeroHom R R') (j : M →+ M') (hi : Surjective i) (hj : ∀ m, j m = 0 → m = 0)
(hc : ∀ (r : R) (m : M), j (r • m) = i r • j m) : LinearIndependent R' (j ∘ v) := by
obtain ⟨i', hi'⟩ := hi.hasRightInverse
refine hv.map_of_injective_injective i' j (fun _ h ↦ ?_) hj fun r m ↦ ?_
· apply_fun i at h
rwa [hi', i.map_zero] at h
rw [hc (i' r) m, hi']
theorem LinearIndependent.of_comp (f : M →ₗ[R] M') (hfv : LinearIndependent R (f ∘ v)) :
LinearIndependent R v :=
linearIndependent_iff'.2 fun s g hg i his =>
have : (∑ i ∈ s, g i • f (v i)) = 0 := by
simp_rw [← map_smul, ← map_sum, hg, f.map_zero]
linearIndependent_iff'.1 hfv s g this i his
#align linear_independent.of_comp LinearIndependent.of_comp
protected theorem LinearMap.linearIndependent_iff (f : M →ₗ[R] M') (hf_inj : LinearMap.ker f = ⊥) :
LinearIndependent R (f ∘ v) ↔ LinearIndependent R v :=
⟨fun h => h.of_comp f, fun h => h.map <| by simp only [hf_inj, disjoint_bot_right]⟩
#align linear_map.linear_independent_iff LinearMap.linearIndependent_iff
@[nontriviality]
theorem linearIndependent_of_subsingleton [Subsingleton R] : LinearIndependent R v :=
linearIndependent_iff.2 fun _l _hl => Subsingleton.elim _ _
#align linear_independent_of_subsingleton linearIndependent_of_subsingleton
theorem linearIndependent_equiv (e : ι ≃ ι') {f : ι' → M} :
LinearIndependent R (f ∘ e) ↔ LinearIndependent R f :=
⟨fun h => Function.comp_id f ▸ e.self_comp_symm ▸ h.comp _ e.symm.injective, fun h =>
h.comp _ e.injective⟩
#align linear_independent_equiv linearIndependent_equiv
theorem linearIndependent_equiv' (e : ι ≃ ι') {f : ι' → M} {g : ι → M} (h : f ∘ e = g) :
LinearIndependent R g ↔ LinearIndependent R f :=
h ▸ linearIndependent_equiv e
#align linear_independent_equiv' linearIndependent_equiv'
theorem linearIndependent_subtype_range {ι} {f : ι → M} (hf : Injective f) :
LinearIndependent R ((↑) : range f → M) ↔ LinearIndependent R f :=
Iff.symm <| linearIndependent_equiv' (Equiv.ofInjective f hf) rfl
#align linear_independent_subtype_range linearIndependent_subtype_range
alias ⟨LinearIndependent.of_subtype_range, _⟩ := linearIndependent_subtype_range
#align linear_independent.of_subtype_range LinearIndependent.of_subtype_range
theorem linearIndependent_image {ι} {s : Set ι} {f : ι → M} (hf : Set.InjOn f s) :
(LinearIndependent R fun x : s => f x) ↔ LinearIndependent R fun x : f '' s => (x : M) :=
linearIndependent_equiv' (Equiv.Set.imageOfInjOn _ _ hf) rfl
#align linear_independent_image linearIndependent_image
theorem linearIndependent_span (hs : LinearIndependent R v) :
LinearIndependent R (M := span R (range v))
(fun i : ι => ⟨v i, subset_span (mem_range_self i)⟩) :=
LinearIndependent.of_comp (span R (range v)).subtype hs
#align linear_independent_span linearIndependent_span
theorem LinearIndependent.fin_cons' {m : ℕ} (x : M) (v : Fin m → M) (hli : LinearIndependent R v)
(x_ortho : ∀ (c : R) (y : Submodule.span R (Set.range v)), c • x + y = (0 : M) → c = 0) :
LinearIndependent R (Fin.cons x v : Fin m.succ → M) := by
rw [Fintype.linearIndependent_iff] at hli ⊢
rintro g total_eq j
simp_rw [Fin.sum_univ_succ, Fin.cons_zero, Fin.cons_succ] at total_eq
have : g 0 = 0 := by
refine x_ortho (g 0) ⟨∑ i : Fin m, g i.succ • v i, ?_⟩ total_eq
exact sum_mem fun i _ => smul_mem _ _ (subset_span ⟨i, rfl⟩)
rw [this, zero_smul, zero_add] at total_eq
exact Fin.cases this (hli _ total_eq) j
#align linear_independent.fin_cons' LinearIndependent.fin_cons'
theorem LinearIndependent.restrict_scalars [Semiring K] [SMulWithZero R K] [Module K M]
[IsScalarTower R K M] (hinj : Function.Injective fun r : R => r • (1 : K))
(li : LinearIndependent K v) : LinearIndependent R v := by
refine linearIndependent_iff'.mpr fun s g hg i hi => hinj ?_
dsimp only; rw [zero_smul]
refine (linearIndependent_iff'.mp li : _) _ (g · • (1:K)) ?_ i hi
simp_rw [smul_assoc, one_smul]
exact hg
#align linear_independent.restrict_scalars LinearIndependent.restrict_scalars
theorem linearIndependent_finset_map_embedding_subtype (s : Set M)
(li : LinearIndependent R ((↑) : s → M)) (t : Finset s) :
LinearIndependent R ((↑) : Finset.map (Embedding.subtype s) t → M) := by
let f : t.map (Embedding.subtype s) → s := fun x =>
⟨x.1, by
obtain ⟨x, h⟩ := x
rw [Finset.mem_map] at h
obtain ⟨a, _ha, rfl⟩ := h
simp only [Subtype.coe_prop, Embedding.coe_subtype]⟩
convert LinearIndependent.comp li f ?_
rintro ⟨x, hx⟩ ⟨y, hy⟩
rw [Finset.mem_map] at hx hy
obtain ⟨a, _ha, rfl⟩ := hx
obtain ⟨b, _hb, rfl⟩ := hy
simp only [f, imp_self, Subtype.mk_eq_mk]
#align linear_independent_finset_map_embedding_subtype linearIndependent_finset_map_embedding_subtype
theorem linearIndependent_bounded_of_finset_linearIndependent_bounded {n : ℕ}
(H : ∀ s : Finset M, (LinearIndependent R fun i : s => (i : M)) → s.card ≤ n) :
∀ s : Set M, LinearIndependent R ((↑) : s → M) → #s ≤ n := by
intro s li
apply Cardinal.card_le_of
intro t
rw [← Finset.card_map (Embedding.subtype s)]
apply H
apply linearIndependent_finset_map_embedding_subtype _ li
#align linear_independent_bounded_of_finset_linear_independent_bounded linearIndependent_bounded_of_finset_linearIndependent_bounded
section Subtype
theorem linearIndependent_comp_subtype {s : Set ι} :
LinearIndependent R (v ∘ (↑) : s → M) ↔
∀ l ∈ Finsupp.supported R R s, (Finsupp.total ι M R v) l = 0 → l = 0 := by
simp only [linearIndependent_iff, (· ∘ ·), Finsupp.mem_supported, Finsupp.total_apply,
Set.subset_def, Finset.mem_coe]
constructor
· intro h l hl₁ hl₂
have := h (l.subtypeDomain s) ((Finsupp.sum_subtypeDomain_index hl₁).trans hl₂)
exact (Finsupp.subtypeDomain_eq_zero_iff hl₁).1 this
· intro h l hl
refine Finsupp.embDomain_eq_zero.1 (h (l.embDomain <| Function.Embedding.subtype s) ?_ ?_)
· suffices ∀ i hi, ¬l ⟨i, hi⟩ = 0 → i ∈ s by simpa
intros
assumption
· rwa [Finsupp.embDomain_eq_mapDomain, Finsupp.sum_mapDomain_index]
exacts [fun _ => zero_smul _ _, fun _ _ _ => add_smul _ _ _]
#align linear_independent_comp_subtype linearIndependent_comp_subtype
theorem linearDependent_comp_subtype' {s : Set ι} :
¬LinearIndependent R (v ∘ (↑) : s → M) ↔
∃ f : ι →₀ R, f ∈ Finsupp.supported R R s ∧ Finsupp.total ι M R v f = 0 ∧ f ≠ 0 := by
simp [linearIndependent_comp_subtype, and_left_comm]
#align linear_dependent_comp_subtype' linearDependent_comp_subtype'
theorem linearDependent_comp_subtype {s : Set ι} :
¬LinearIndependent R (v ∘ (↑) : s → M) ↔
∃ f : ι →₀ R, f ∈ Finsupp.supported R R s ∧ ∑ i ∈ f.support, f i • v i = 0 ∧ f ≠ 0 :=
linearDependent_comp_subtype'
#align linear_dependent_comp_subtype linearDependent_comp_subtype
theorem linearIndependent_subtype {s : Set M} :
LinearIndependent R (fun x => x : s → M) ↔
∀ l ∈ Finsupp.supported R R s, (Finsupp.total M M R id) l = 0 → l = 0 := by
apply linearIndependent_comp_subtype (v := id)
#align linear_independent_subtype linearIndependent_subtype
theorem linearIndependent_comp_subtype_disjoint {s : Set ι} :
LinearIndependent R (v ∘ (↑) : s → M) ↔
Disjoint (Finsupp.supported R R s) (LinearMap.ker <| Finsupp.total ι M R v) := by
rw [linearIndependent_comp_subtype, LinearMap.disjoint_ker]
#align linear_independent_comp_subtype_disjoint linearIndependent_comp_subtype_disjoint
theorem linearIndependent_subtype_disjoint {s : Set M} :
LinearIndependent R (fun x => x : s → M) ↔
Disjoint (Finsupp.supported R R s) (LinearMap.ker <| Finsupp.total M M R id) := by
apply linearIndependent_comp_subtype_disjoint (v := id)
#align linear_independent_subtype_disjoint linearIndependent_subtype_disjoint
theorem linearIndependent_iff_totalOn {s : Set M} :
LinearIndependent R (fun x => x : s → M) ↔
(LinearMap.ker <| Finsupp.totalOn M M R id s) = ⊥ := by
rw [Finsupp.totalOn, LinearMap.ker, LinearMap.comap_codRestrict, Submodule.map_bot, comap_bot,
LinearMap.ker_comp, linearIndependent_subtype_disjoint, disjoint_iff_inf_le, ←
map_comap_subtype, map_le_iff_le_comap, comap_bot, ker_subtype, le_bot_iff]
#align linear_independent_iff_total_on linearIndependent_iff_totalOn
theorem LinearIndependent.restrict_of_comp_subtype {s : Set ι}
(hs : LinearIndependent R (v ∘ (↑) : s → M)) : LinearIndependent R (s.restrict v) :=
hs
#align linear_independent.restrict_of_comp_subtype LinearIndependent.restrict_of_comp_subtype
variable (R M)
| Mathlib/LinearAlgebra/LinearIndependent.lean | 499 | 500 | theorem linearIndependent_empty : LinearIndependent R (fun x => x : (∅ : Set M) → M) := by |
simp [linearIndependent_subtype_disjoint]
|
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.
| Mathlib/Data/Bool/Basic.lean | 151 | 151 | theorem not_iff_not : ∀ {b : Bool}, !b ↔ ¬b := by | simp
|
import Mathlib.Analysis.Calculus.Deriv.Basic
import Mathlib.Analysis.Calculus.FDeriv.Mul
import Mathlib.Analysis.Calculus.FDeriv.Add
#align_import analysis.calculus.deriv.mul from "leanprover-community/mathlib"@"3bce8d800a6f2b8f63fe1e588fd76a9ff4adcebe"
universe u v w
noncomputable section
open scoped Classical 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 {G : Type*} [NormedAddCommGroup G] [NormedSpace 𝕜 G]
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 Mul
variable {𝕜' 𝔸 : Type*} [NormedField 𝕜'] [NormedRing 𝔸] [NormedAlgebra 𝕜 𝕜'] [NormedAlgebra 𝕜 𝔸]
{c d : 𝕜 → 𝔸} {c' d' : 𝔸} {u v : 𝕜 → 𝕜'}
theorem HasDerivWithinAt.mul (hc : HasDerivWithinAt c c' s x) (hd : HasDerivWithinAt d d' s x) :
HasDerivWithinAt (fun y => c y * d y) (c' * d x + c x * d') s x := by
have := (HasFDerivWithinAt.mul' hc hd).hasDerivWithinAt
rwa [ContinuousLinearMap.add_apply, ContinuousLinearMap.smul_apply,
ContinuousLinearMap.smulRight_apply, ContinuousLinearMap.smulRight_apply,
ContinuousLinearMap.smulRight_apply, ContinuousLinearMap.one_apply, one_smul, one_smul,
add_comm] at this
#align has_deriv_within_at.mul HasDerivWithinAt.mul
theorem HasDerivAt.mul (hc : HasDerivAt c c' x) (hd : HasDerivAt d d' x) :
HasDerivAt (fun y => c y * d y) (c' * d x + c x * d') x := by
rw [← hasDerivWithinAt_univ] at *
exact hc.mul hd
#align has_deriv_at.mul HasDerivAt.mul
| Mathlib/Analysis/Calculus/Deriv/Mul.lean | 221 | 227 | theorem HasStrictDerivAt.mul (hc : HasStrictDerivAt c c' x) (hd : HasStrictDerivAt d d' x) :
HasStrictDerivAt (fun y => c y * d y) (c' * d x + c x * d') x := by |
have := (HasStrictFDerivAt.mul' hc hd).hasStrictDerivAt
rwa [ContinuousLinearMap.add_apply, ContinuousLinearMap.smul_apply,
ContinuousLinearMap.smulRight_apply, ContinuousLinearMap.smulRight_apply,
ContinuousLinearMap.smulRight_apply, ContinuousLinearMap.one_apply, one_smul, one_smul,
add_comm] at this
|
import Mathlib.LinearAlgebra.Matrix.Charpoly.Coeff
import Mathlib.FieldTheory.Finite.Basic
import Mathlib.Data.Matrix.CharP
#align_import linear_algebra.matrix.charpoly.finite_field from "leanprover-community/mathlib"@"b95b8c7a484a298228805c72c142f6b062eb0d70"
noncomputable section
open Polynomial Matrix
open scoped Polynomial
variable {n : Type*} [DecidableEq n] [Fintype n]
@[simp]
| Mathlib/LinearAlgebra/Matrix/Charpoly/FiniteField.lean | 26 | 43 | theorem FiniteField.Matrix.charpoly_pow_card {K : Type*} [Field K] [Fintype K] (M : Matrix n n K) :
(M ^ Fintype.card K).charpoly = M.charpoly := by |
cases (isEmpty_or_nonempty n).symm
· cases' CharP.exists K with p hp; letI := hp
rcases FiniteField.card K p with ⟨⟨k, kpos⟩, ⟨hp, hk⟩⟩
haveI : Fact p.Prime := ⟨hp⟩
dsimp at hk; rw [hk]
apply (frobenius_inj K[X] p).iterate k
repeat' rw [iterate_frobenius (R := K[X])]; rw [← hk]
rw [← FiniteField.expand_card]
unfold charpoly
rw [AlgHom.map_det, ← coe_detMonoidHom, ← (detMonoidHom : Matrix n n K[X] →* K[X]).map_pow]
apply congr_arg det
refine matPolyEquiv.injective ?_
rw [AlgEquiv.map_pow, matPolyEquiv_charmatrix, hk, sub_pow_char_pow_of_commute, ← C_pow]
· exact (id (matPolyEquiv_eq_X_pow_sub_C (p ^ k) M) : _)
· exact (C M).commute_X
· exact congr_arg _ (Subsingleton.elim _ _)
|
import Mathlib.Geometry.Manifold.VectorBundle.Basic
import Mathlib.Analysis.Convex.Normed
#align_import geometry.manifold.vector_bundle.tangent from "leanprover-community/mathlib"@"e473c3198bb41f68560cab68a0529c854b618833"
open Bundle Set SmoothManifoldWithCorners PartialHomeomorph ContinuousLinearMap
open scoped Manifold Topology Bundle
noncomputable section
section General
variable {𝕜 : Type*} [NontriviallyNormedField 𝕜] {E : Type*} [NormedAddCommGroup E]
[NormedSpace 𝕜 E] {E' : Type*} [NormedAddCommGroup E'] [NormedSpace 𝕜 E'] {H : Type*}
[TopologicalSpace H] {I : ModelWithCorners 𝕜 E H} {H' : Type*} [TopologicalSpace H']
{I' : ModelWithCorners 𝕜 E' H'} {M : Type*} [TopologicalSpace M] [ChartedSpace H M]
[SmoothManifoldWithCorners I M] {M' : Type*} [TopologicalSpace M'] [ChartedSpace H' M']
[SmoothManifoldWithCorners I' M'] {F : Type*} [NormedAddCommGroup F] [NormedSpace 𝕜 F]
variable (I)
theorem contDiffOn_fderiv_coord_change (i j : atlas H M) :
ContDiffOn 𝕜 ∞ (fderivWithin 𝕜 (j.1.extend I ∘ (i.1.extend I).symm) (range I))
((i.1.extend I).symm ≫ j.1.extend I).source := by
have h : ((i.1.extend I).symm ≫ j.1.extend I).source ⊆ range I := by
rw [i.1.extend_coord_change_source]; apply image_subset_range
intro x hx
refine (ContDiffWithinAt.fderivWithin_right ?_ I.unique_diff le_top <| h hx).mono h
refine (PartialHomeomorph.contDiffOn_extend_coord_change I (subset_maximalAtlas I j.2)
(subset_maximalAtlas I i.2) x hx).mono_of_mem ?_
exact i.1.extend_coord_change_source_mem_nhdsWithin j.1 I hx
#align cont_diff_on_fderiv_coord_change contDiffOn_fderiv_coord_change
variable (M)
open SmoothManifoldWithCorners
@[simps indexAt coordChange]
def tangentBundleCore : VectorBundleCore 𝕜 M E (atlas H M) where
baseSet i := i.1.source
isOpen_baseSet i := i.1.open_source
indexAt := achart H
mem_baseSet_at := mem_chart_source H
coordChange i j x :=
fderivWithin 𝕜 (j.1.extend I ∘ (i.1.extend I).symm) (range I) (i.1.extend I x)
coordChange_self i x hx v := by
simp only
rw [Filter.EventuallyEq.fderivWithin_eq, fderivWithin_id', ContinuousLinearMap.id_apply]
· exact I.unique_diff_at_image
· filter_upwards [i.1.extend_target_mem_nhdsWithin I hx] with y hy
exact (i.1.extend I).right_inv hy
· simp_rw [Function.comp_apply, i.1.extend_left_inv I hx]
continuousOn_coordChange i j := by
refine (contDiffOn_fderiv_coord_change I i j).continuousOn.comp
((i.1.continuousOn_extend I).mono ?_) ?_
· rw [i.1.extend_source]; exact inter_subset_left
simp_rw [← i.1.extend_image_source_inter, mapsTo_image]
coordChange_comp := by
rintro i j k x ⟨⟨hxi, hxj⟩, hxk⟩ v
rw [fderivWithin_fderivWithin, Filter.EventuallyEq.fderivWithin_eq]
· have := i.1.extend_preimage_mem_nhds I hxi (j.1.extend_source_mem_nhds I hxj)
filter_upwards [nhdsWithin_le_nhds this] with y hy
simp_rw [Function.comp_apply, (j.1.extend I).left_inv hy]
· simp_rw [Function.comp_apply, i.1.extend_left_inv I hxi, j.1.extend_left_inv I hxj]
· exact (contDiffWithinAt_extend_coord_change' I (subset_maximalAtlas I k.2)
(subset_maximalAtlas I j.2) hxk hxj).differentiableWithinAt le_top
· exact (contDiffWithinAt_extend_coord_change' I (subset_maximalAtlas I j.2)
(subset_maximalAtlas I i.2) hxj hxi).differentiableWithinAt le_top
· intro x _; exact mem_range_self _
· exact I.unique_diff_at_image
· rw [Function.comp_apply, i.1.extend_left_inv I hxi]
#align tangent_bundle_core tangentBundleCore
-- Porting note: moved to a separate `simp high` lemma b/c `simp` can simplify the LHS
@[simp high]
theorem tangentBundleCore_baseSet (i) : (tangentBundleCore I M).baseSet i = i.1.source := rfl
variable {M}
theorem tangentBundleCore_coordChange_achart (x x' z : M) :
(tangentBundleCore I M).coordChange (achart H x) (achart H x') z =
fderivWithin 𝕜 (extChartAt I x' ∘ (extChartAt I x).symm) (range I) (extChartAt I x z) :=
rfl
#align tangent_bundle_core_coord_change_achart tangentBundleCore_coordChange_achart
@[nolint unusedArguments]
def TangentSpace {𝕜} [NontriviallyNormedField 𝕜] {E} [NormedAddCommGroup E] [NormedSpace 𝕜 E]
{H} [TopologicalSpace H] (I : ModelWithCorners 𝕜 E H) {M} [TopologicalSpace M]
[ChartedSpace H M] [SmoothManifoldWithCorners I M] (_x : M) : Type* := E
-- Porting note: was deriving TopologicalSpace, AddCommGroup, TopologicalAddGroup
#align tangent_space TangentSpace
instance {x : M} : TopologicalSpace (TangentSpace I x) := inferInstanceAs (TopologicalSpace E)
instance {x : M} : AddCommGroup (TangentSpace I x) := inferInstanceAs (AddCommGroup E)
instance {x : M} : TopologicalAddGroup (TangentSpace I x) := inferInstanceAs (TopologicalAddGroup E)
variable (M)
-- is empty if the base manifold is empty
-- Porting note(#5171): was nolint has_nonempty_instance
abbrev TangentBundle :=
Bundle.TotalSpace E (TangentSpace I : M → Type _)
#align tangent_bundle TangentBundle
local notation "TM" => TangentBundle I M
section TangentBundleInstances
section
variable {M} (x : M)
instance : Module 𝕜 (TangentSpace I x) := inferInstanceAs (Module 𝕜 E)
instance : Inhabited (TangentSpace I x) := ⟨0⟩
-- Porting note: removed unneeded ContinuousAdd (TangentSpace I x)
end
instance : TopologicalSpace TM :=
(tangentBundleCore I M).toTopologicalSpace
instance TangentSpace.fiberBundle : FiberBundle E (TangentSpace I : M → Type _) :=
(tangentBundleCore I M).fiberBundle
instance TangentSpace.vectorBundle : VectorBundle 𝕜 E (TangentSpace I : M → Type _) :=
(tangentBundleCore I M).vectorBundle
namespace TangentBundle
protected theorem chartAt (p : TM) :
chartAt (ModelProd H E) p =
((tangentBundleCore I M).toFiberBundleCore.localTriv (achart H p.1)).toPartialHomeomorph ≫ₕ
(chartAt H p.1).prod (PartialHomeomorph.refl E) :=
rfl
#align tangent_bundle.chart_at TangentBundle.chartAt
theorem chartAt_toPartialEquiv (p : TM) :
(chartAt (ModelProd H E) p).toPartialEquiv =
(tangentBundleCore I M).toFiberBundleCore.localTrivAsPartialEquiv (achart H p.1) ≫
(chartAt H p.1).toPartialEquiv.prod (PartialEquiv.refl E) :=
rfl
#align tangent_bundle.chart_at_to_local_equiv TangentBundle.chartAt_toPartialEquiv
theorem trivializationAt_eq_localTriv (x : M) :
trivializationAt E (TangentSpace I) x =
(tangentBundleCore I M).toFiberBundleCore.localTriv (achart H x) :=
rfl
#align tangent_bundle.trivialization_at_eq_local_triv TangentBundle.trivializationAt_eq_localTriv
@[simp, mfld_simps]
theorem trivializationAt_source (x : M) :
(trivializationAt E (TangentSpace I) x).source =
π E (TangentSpace I) ⁻¹' (chartAt H x).source :=
rfl
#align tangent_bundle.trivialization_at_source TangentBundle.trivializationAt_source
@[simp, mfld_simps]
theorem trivializationAt_target (x : M) :
(trivializationAt E (TangentSpace I) x).target = (chartAt H x).source ×ˢ univ :=
rfl
#align tangent_bundle.trivialization_at_target TangentBundle.trivializationAt_target
@[simp, mfld_simps]
theorem trivializationAt_baseSet (x : M) :
(trivializationAt E (TangentSpace I) x).baseSet = (chartAt H x).source :=
rfl
#align tangent_bundle.trivialization_at_base_set TangentBundle.trivializationAt_baseSet
theorem trivializationAt_apply (x : M) (z : TM) :
trivializationAt E (TangentSpace I) x z =
(z.1, fderivWithin 𝕜 ((chartAt H x).extend I ∘ ((chartAt H z.1).extend I).symm) (range I)
((chartAt H z.1).extend I z.1) z.2) :=
rfl
#align tangent_bundle.trivialization_at_apply TangentBundle.trivializationAt_apply
@[simp, mfld_simps]
theorem trivializationAt_fst (x : M) (z : TM) : (trivializationAt E (TangentSpace I) x z).1 = z.1 :=
rfl
#align tangent_bundle.trivialization_at_fst TangentBundle.trivializationAt_fst
@[simp, mfld_simps]
theorem mem_chart_source_iff (p q : TM) :
p ∈ (chartAt (ModelProd H E) q).source ↔ p.1 ∈ (chartAt H q.1).source := by
simp only [FiberBundle.chartedSpace_chartAt, mfld_simps]
#align tangent_bundle.mem_chart_source_iff TangentBundle.mem_chart_source_iff
@[simp, mfld_simps]
theorem mem_chart_target_iff (p : H × E) (q : TM) :
p ∈ (chartAt (ModelProd H E) q).target ↔ p.1 ∈ (chartAt H q.1).target := by
simp only [FiberBundle.chartedSpace_chartAt, mfld_simps]
rw [PartialEquiv.prod_symm]
simp (config := { contextual := true }) only [and_iff_left_iff_imp, mfld_simps]
#align tangent_bundle.mem_chart_target_iff TangentBundle.mem_chart_target_iff
@[simp, mfld_simps]
theorem coe_chartAt_fst (p q : TM) : ((chartAt (ModelProd H E) q) p).1 = chartAt H q.1 p.1 :=
rfl
#align tangent_bundle.coe_chart_at_fst TangentBundle.coe_chartAt_fst
@[simp, mfld_simps]
theorem coe_chartAt_symm_fst (p : H × E) (q : TM) :
((chartAt (ModelProd H E) q).symm p).1 = ((chartAt H q.1).symm : H → M) p.1 :=
rfl
#align tangent_bundle.coe_chart_at_symm_fst TangentBundle.coe_chartAt_symm_fst
@[simp, mfld_simps]
theorem trivializationAt_continuousLinearMapAt {b₀ b : M}
(hb : b ∈ (trivializationAt E (TangentSpace I) b₀).baseSet) :
(trivializationAt E (TangentSpace I) b₀).continuousLinearMapAt 𝕜 b =
(tangentBundleCore I M).coordChange (achart H b) (achart H b₀) b :=
(tangentBundleCore I M).localTriv_continuousLinearMapAt hb
#align tangent_bundle.trivialization_at_continuous_linear_map_at TangentBundle.trivializationAt_continuousLinearMapAt
@[simp, mfld_simps]
theorem trivializationAt_symmL {b₀ b : M}
(hb : b ∈ (trivializationAt E (TangentSpace I) b₀).baseSet) :
(trivializationAt E (TangentSpace I) b₀).symmL 𝕜 b =
(tangentBundleCore I M).coordChange (achart H b₀) (achart H b) b :=
(tangentBundleCore I M).localTriv_symmL hb
set_option linter.uppercaseLean3 false in
#align tangent_bundle.trivialization_at_symmL TangentBundle.trivializationAt_symmL
-- Porting note: `simp` simplifies LHS to `.id _ _`
@[simp high, mfld_simps]
| Mathlib/Geometry/Manifold/VectorBundle/Tangent.lean | 326 | 329 | theorem coordChange_model_space (b b' x : F) :
(tangentBundleCore 𝓘(𝕜, F) F).coordChange (achart F b) (achart F b') x = 1 := by |
simpa only [tangentBundleCore_coordChange, mfld_simps] using
fderivWithin_id uniqueDiffWithinAt_univ
|
import Mathlib.Algebra.Polynomial.AlgebraMap
import Mathlib.Algebra.Polynomial.Inductions
import Mathlib.Algebra.Polynomial.Splits
import Mathlib.Analysis.Normed.Field.Basic
import Mathlib.RingTheory.Polynomial.Vieta
#align_import topology.algebra.polynomial from "leanprover-community/mathlib"@"565eb991e264d0db702722b4bde52ee5173c9950"
open IsAbsoluteValue Filter
namespace Polynomial
open Polynomial
theorem tendsto_abv_eval₂_atTop {R S k α : Type*} [Semiring R] [Ring S] [LinearOrderedField k]
(f : R →+* S) (abv : S → k) [IsAbsoluteValue abv] (p : R[X]) (hd : 0 < degree p)
(hf : f p.leadingCoeff ≠ 0) {l : Filter α} {z : α → S} (hz : Tendsto (abv ∘ z) l atTop) :
Tendsto (fun x => abv (p.eval₂ f (z x))) l atTop := by
revert hf; refine degree_pos_induction_on p hd ?_ ?_ ?_ <;> clear hd p
· rintro _ - hc
rw [leadingCoeff_mul_X, leadingCoeff_C] at hc
simpa [abv_mul abv] using hz.const_mul_atTop ((abv_pos abv).2 hc)
· intro _ _ ihp hf
rw [leadingCoeff_mul_X] at hf
simpa [abv_mul abv] using (ihp hf).atTop_mul_atTop hz
· intro _ a hd ihp hf
rw [add_comm, leadingCoeff_add_of_degree_lt (degree_C_le.trans_lt hd)] at hf
refine tendsto_atTop_of_add_const_right (abv (-f a)) ?_
refine tendsto_atTop_mono (fun _ => abv_add abv _ _) ?_
simpa using ihp hf
#align polynomial.tendsto_abv_eval₂_at_top Polynomial.tendsto_abv_eval₂_atTop
| Mathlib/Topology/Algebra/Polynomial.lean | 123 | 127 | theorem tendsto_abv_atTop {R k α : Type*} [Ring R] [LinearOrderedField k] (abv : R → k)
[IsAbsoluteValue abv] (p : R[X]) (h : 0 < degree p) {l : Filter α} {z : α → R}
(hz : Tendsto (abv ∘ z) l atTop) : Tendsto (fun x => abv (p.eval (z x))) l atTop := by |
apply tendsto_abv_eval₂_atTop _ _ _ h _ hz
exact mt leadingCoeff_eq_zero.1 (ne_zero_of_degree_gt h)
|
import Mathlib.Combinatorics.SimpleGraph.Subgraph
import Mathlib.Data.List.Rotate
#align_import combinatorics.simple_graph.connectivity from "leanprover-community/mathlib"@"b99e2d58a5e6861833fa8de11e51a81144258db4"
open Function
universe u v w
namespace SimpleGraph
variable {V : Type u} {V' : Type v} {V'' : Type w}
variable (G : SimpleGraph V) (G' : SimpleGraph V') (G'' : SimpleGraph V'')
inductive Walk : V → V → Type u
| nil {u : V} : Walk u u
| cons {u v w : V} (h : G.Adj u v) (p : Walk v w) : Walk u w
deriving DecidableEq
#align simple_graph.walk SimpleGraph.Walk
attribute [refl] Walk.nil
@[simps]
instance Walk.instInhabited (v : V) : Inhabited (G.Walk v v) := ⟨Walk.nil⟩
#align simple_graph.walk.inhabited SimpleGraph.Walk.instInhabited
@[match_pattern, reducible]
def Adj.toWalk {G : SimpleGraph V} {u v : V} (h : G.Adj u v) : G.Walk u v :=
Walk.cons h Walk.nil
#align simple_graph.adj.to_walk SimpleGraph.Adj.toWalk
namespace Walk
variable {G}
@[match_pattern]
abbrev nil' (u : V) : G.Walk u u := Walk.nil
#align simple_graph.walk.nil' SimpleGraph.Walk.nil'
@[match_pattern]
abbrev cons' (u v w : V) (h : G.Adj u v) (p : G.Walk v w) : G.Walk u w := Walk.cons h p
#align simple_graph.walk.cons' SimpleGraph.Walk.cons'
protected def copy {u v u' v'} (p : G.Walk u v) (hu : u = u') (hv : v = v') : G.Walk u' v' :=
hu ▸ hv ▸ p
#align simple_graph.walk.copy SimpleGraph.Walk.copy
@[simp]
theorem copy_rfl_rfl {u v} (p : G.Walk u v) : p.copy rfl rfl = p := rfl
#align simple_graph.walk.copy_rfl_rfl SimpleGraph.Walk.copy_rfl_rfl
@[simp]
theorem copy_copy {u v u' v' u'' v''} (p : G.Walk u v)
(hu : u = u') (hv : v = v') (hu' : u' = u'') (hv' : v' = v'') :
(p.copy hu hv).copy hu' hv' = p.copy (hu.trans hu') (hv.trans hv') := by
subst_vars
rfl
#align simple_graph.walk.copy_copy SimpleGraph.Walk.copy_copy
@[simp]
theorem copy_nil {u u'} (hu : u = u') : (Walk.nil : G.Walk u u).copy hu hu = Walk.nil := by
subst_vars
rfl
#align simple_graph.walk.copy_nil SimpleGraph.Walk.copy_nil
theorem copy_cons {u v w u' w'} (h : G.Adj u v) (p : G.Walk v w) (hu : u = u') (hw : w = w') :
(Walk.cons h p).copy hu hw = Walk.cons (hu ▸ h) (p.copy rfl hw) := by
subst_vars
rfl
#align simple_graph.walk.copy_cons SimpleGraph.Walk.copy_cons
@[simp]
theorem cons_copy {u v w v' w'} (h : G.Adj u v) (p : G.Walk v' w') (hv : v' = v) (hw : w' = w) :
Walk.cons h (p.copy hv hw) = (Walk.cons (hv ▸ h) p).copy rfl hw := by
subst_vars
rfl
#align simple_graph.walk.cons_copy SimpleGraph.Walk.cons_copy
theorem exists_eq_cons_of_ne {u v : V} (hne : u ≠ v) :
∀ (p : G.Walk u v), ∃ (w : V) (h : G.Adj u w) (p' : G.Walk w v), p = cons h p'
| nil => (hne rfl).elim
| cons h p' => ⟨_, h, p', rfl⟩
#align simple_graph.walk.exists_eq_cons_of_ne SimpleGraph.Walk.exists_eq_cons_of_ne
def length {u v : V} : G.Walk u v → ℕ
| nil => 0
| cons _ q => q.length.succ
#align simple_graph.walk.length SimpleGraph.Walk.length
@[trans]
def append {u v w : V} : G.Walk u v → G.Walk v w → G.Walk u w
| nil, q => q
| cons h p, q => cons h (p.append q)
#align simple_graph.walk.append SimpleGraph.Walk.append
def concat {u v w : V} (p : G.Walk u v) (h : G.Adj v w) : G.Walk u w := p.append (cons h nil)
#align simple_graph.walk.concat SimpleGraph.Walk.concat
theorem concat_eq_append {u v w : V} (p : G.Walk u v) (h : G.Adj v w) :
p.concat h = p.append (cons h nil) := rfl
#align simple_graph.walk.concat_eq_append SimpleGraph.Walk.concat_eq_append
protected def reverseAux {u v w : V} : G.Walk u v → G.Walk u w → G.Walk v w
| nil, q => q
| cons h p, q => Walk.reverseAux p (cons (G.symm h) q)
#align simple_graph.walk.reverse_aux SimpleGraph.Walk.reverseAux
@[symm]
def reverse {u v : V} (w : G.Walk u v) : G.Walk v u := w.reverseAux nil
#align simple_graph.walk.reverse SimpleGraph.Walk.reverse
def getVert {u v : V} : G.Walk u v → ℕ → V
| nil, _ => u
| cons _ _, 0 => u
| cons _ q, n + 1 => q.getVert n
#align simple_graph.walk.get_vert SimpleGraph.Walk.getVert
@[simp]
theorem getVert_zero {u v} (w : G.Walk u v) : w.getVert 0 = u := by cases w <;> rfl
#align simple_graph.walk.get_vert_zero SimpleGraph.Walk.getVert_zero
theorem getVert_of_length_le {u v} (w : G.Walk u v) {i : ℕ} (hi : w.length ≤ i) :
w.getVert i = v := by
induction w generalizing i with
| nil => rfl
| cons _ _ ih =>
cases i
· cases hi
· exact ih (Nat.succ_le_succ_iff.1 hi)
#align simple_graph.walk.get_vert_of_length_le SimpleGraph.Walk.getVert_of_length_le
@[simp]
theorem getVert_length {u v} (w : G.Walk u v) : w.getVert w.length = v :=
w.getVert_of_length_le rfl.le
#align simple_graph.walk.get_vert_length SimpleGraph.Walk.getVert_length
theorem adj_getVert_succ {u v} (w : G.Walk u v) {i : ℕ} (hi : i < w.length) :
G.Adj (w.getVert i) (w.getVert (i + 1)) := by
induction w generalizing i with
| nil => cases hi
| cons hxy _ ih =>
cases i
· simp [getVert, hxy]
· exact ih (Nat.succ_lt_succ_iff.1 hi)
#align simple_graph.walk.adj_get_vert_succ SimpleGraph.Walk.adj_getVert_succ
@[simp]
theorem cons_append {u v w x : V} (h : G.Adj u v) (p : G.Walk v w) (q : G.Walk w x) :
(cons h p).append q = cons h (p.append q) := rfl
#align simple_graph.walk.cons_append SimpleGraph.Walk.cons_append
@[simp]
theorem cons_nil_append {u v w : V} (h : G.Adj u v) (p : G.Walk v w) :
(cons h nil).append p = cons h p := rfl
#align simple_graph.walk.cons_nil_append SimpleGraph.Walk.cons_nil_append
@[simp]
theorem append_nil {u v : V} (p : G.Walk u v) : p.append nil = p := by
induction p with
| nil => rfl
| cons _ _ ih => rw [cons_append, ih]
#align simple_graph.walk.append_nil SimpleGraph.Walk.append_nil
@[simp]
theorem nil_append {u v : V} (p : G.Walk u v) : nil.append p = p :=
rfl
#align simple_graph.walk.nil_append SimpleGraph.Walk.nil_append
theorem append_assoc {u v w x : V} (p : G.Walk u v) (q : G.Walk v w) (r : G.Walk w x) :
p.append (q.append r) = (p.append q).append r := by
induction p with
| nil => rfl
| cons h p' ih =>
dsimp only [append]
rw [ih]
#align simple_graph.walk.append_assoc SimpleGraph.Walk.append_assoc
@[simp]
theorem append_copy_copy {u v w u' v' w'} (p : G.Walk u v) (q : G.Walk v w)
(hu : u = u') (hv : v = v') (hw : w = w') :
(p.copy hu hv).append (q.copy hv hw) = (p.append q).copy hu hw := by
subst_vars
rfl
#align simple_graph.walk.append_copy_copy SimpleGraph.Walk.append_copy_copy
theorem concat_nil {u v : V} (h : G.Adj u v) : nil.concat h = cons h nil := rfl
#align simple_graph.walk.concat_nil SimpleGraph.Walk.concat_nil
@[simp]
theorem concat_cons {u v w x : V} (h : G.Adj u v) (p : G.Walk v w) (h' : G.Adj w x) :
(cons h p).concat h' = cons h (p.concat h') := rfl
#align simple_graph.walk.concat_cons SimpleGraph.Walk.concat_cons
theorem append_concat {u v w x : V} (p : G.Walk u v) (q : G.Walk v w) (h : G.Adj w x) :
p.append (q.concat h) = (p.append q).concat h := append_assoc _ _ _
#align simple_graph.walk.append_concat SimpleGraph.Walk.append_concat
theorem concat_append {u v w x : V} (p : G.Walk u v) (h : G.Adj v w) (q : G.Walk w x) :
(p.concat h).append q = p.append (cons h q) := by
rw [concat_eq_append, ← append_assoc, cons_nil_append]
#align simple_graph.walk.concat_append SimpleGraph.Walk.concat_append
theorem exists_cons_eq_concat {u v w : V} (h : G.Adj u v) (p : G.Walk v w) :
∃ (x : V) (q : G.Walk u x) (h' : G.Adj x w), cons h p = q.concat h' := by
induction p generalizing u with
| nil => exact ⟨_, nil, h, rfl⟩
| cons h' p ih =>
obtain ⟨y, q, h'', hc⟩ := ih h'
refine ⟨y, cons h q, h'', ?_⟩
rw [concat_cons, hc]
#align simple_graph.walk.exists_cons_eq_concat SimpleGraph.Walk.exists_cons_eq_concat
theorem exists_concat_eq_cons {u v w : V} :
∀ (p : G.Walk u v) (h : G.Adj v w),
∃ (x : V) (h' : G.Adj u x) (q : G.Walk x w), p.concat h = cons h' q
| nil, h => ⟨_, h, nil, rfl⟩
| cons h' p, h => ⟨_, h', Walk.concat p h, concat_cons _ _ _⟩
#align simple_graph.walk.exists_concat_eq_cons SimpleGraph.Walk.exists_concat_eq_cons
@[simp]
theorem reverse_nil {u : V} : (nil : G.Walk u u).reverse = nil := rfl
#align simple_graph.walk.reverse_nil SimpleGraph.Walk.reverse_nil
theorem reverse_singleton {u v : V} (h : G.Adj u v) : (cons h nil).reverse = cons (G.symm h) nil :=
rfl
#align simple_graph.walk.reverse_singleton SimpleGraph.Walk.reverse_singleton
@[simp]
theorem cons_reverseAux {u v w x : V} (p : G.Walk u v) (q : G.Walk w x) (h : G.Adj w u) :
(cons h p).reverseAux q = p.reverseAux (cons (G.symm h) q) := rfl
#align simple_graph.walk.cons_reverse_aux SimpleGraph.Walk.cons_reverseAux
@[simp]
protected theorem append_reverseAux {u v w x : V}
(p : G.Walk u v) (q : G.Walk v w) (r : G.Walk u x) :
(p.append q).reverseAux r = q.reverseAux (p.reverseAux r) := by
induction p with
| nil => rfl
| cons h _ ih => exact ih q (cons (G.symm h) r)
#align simple_graph.walk.append_reverse_aux SimpleGraph.Walk.append_reverseAux
@[simp]
protected theorem reverseAux_append {u v w x : V}
(p : G.Walk u v) (q : G.Walk u w) (r : G.Walk w x) :
(p.reverseAux q).append r = p.reverseAux (q.append r) := by
induction p with
| nil => rfl
| cons h _ ih => simp [ih (cons (G.symm h) q)]
#align simple_graph.walk.reverse_aux_append SimpleGraph.Walk.reverseAux_append
protected theorem reverseAux_eq_reverse_append {u v w : V} (p : G.Walk u v) (q : G.Walk u w) :
p.reverseAux q = p.reverse.append q := by simp [reverse]
#align simple_graph.walk.reverse_aux_eq_reverse_append SimpleGraph.Walk.reverseAux_eq_reverse_append
@[simp]
theorem reverse_cons {u v w : V} (h : G.Adj u v) (p : G.Walk v w) :
(cons h p).reverse = p.reverse.append (cons (G.symm h) nil) := by simp [reverse]
#align simple_graph.walk.reverse_cons SimpleGraph.Walk.reverse_cons
@[simp]
theorem reverse_copy {u v u' v'} (p : G.Walk u v) (hu : u = u') (hv : v = v') :
(p.copy hu hv).reverse = p.reverse.copy hv hu := by
subst_vars
rfl
#align simple_graph.walk.reverse_copy SimpleGraph.Walk.reverse_copy
@[simp]
theorem reverse_append {u v w : V} (p : G.Walk u v) (q : G.Walk v w) :
(p.append q).reverse = q.reverse.append p.reverse := by simp [reverse]
#align simple_graph.walk.reverse_append SimpleGraph.Walk.reverse_append
@[simp]
theorem reverse_concat {u v w : V} (p : G.Walk u v) (h : G.Adj v w) :
(p.concat h).reverse = cons (G.symm h) p.reverse := by simp [concat_eq_append]
#align simple_graph.walk.reverse_concat SimpleGraph.Walk.reverse_concat
@[simp]
theorem reverse_reverse {u v : V} (p : G.Walk u v) : p.reverse.reverse = p := by
induction p with
| nil => rfl
| cons _ _ ih => simp [ih]
#align simple_graph.walk.reverse_reverse SimpleGraph.Walk.reverse_reverse
@[simp]
theorem length_nil {u : V} : (nil : G.Walk u u).length = 0 := rfl
#align simple_graph.walk.length_nil SimpleGraph.Walk.length_nil
@[simp]
theorem length_cons {u v w : V} (h : G.Adj u v) (p : G.Walk v w) :
(cons h p).length = p.length + 1 := rfl
#align simple_graph.walk.length_cons SimpleGraph.Walk.length_cons
@[simp]
theorem length_copy {u v u' v'} (p : G.Walk u v) (hu : u = u') (hv : v = v') :
(p.copy hu hv).length = p.length := by
subst_vars
rfl
#align simple_graph.walk.length_copy SimpleGraph.Walk.length_copy
@[simp]
theorem length_append {u v w : V} (p : G.Walk u v) (q : G.Walk v w) :
(p.append q).length = p.length + q.length := by
induction p with
| nil => simp
| cons _ _ ih => simp [ih, add_comm, add_left_comm, add_assoc]
#align simple_graph.walk.length_append SimpleGraph.Walk.length_append
@[simp]
theorem length_concat {u v w : V} (p : G.Walk u v) (h : G.Adj v w) :
(p.concat h).length = p.length + 1 := length_append _ _
#align simple_graph.walk.length_concat SimpleGraph.Walk.length_concat
@[simp]
protected theorem length_reverseAux {u v w : V} (p : G.Walk u v) (q : G.Walk u w) :
(p.reverseAux q).length = p.length + q.length := by
induction p with
| nil => simp!
| cons _ _ ih => simp [ih, Nat.succ_add, Nat.add_assoc]
#align simple_graph.walk.length_reverse_aux SimpleGraph.Walk.length_reverseAux
@[simp]
theorem length_reverse {u v : V} (p : G.Walk u v) : p.reverse.length = p.length := by simp [reverse]
#align simple_graph.walk.length_reverse SimpleGraph.Walk.length_reverse
theorem eq_of_length_eq_zero {u v : V} : ∀ {p : G.Walk u v}, p.length = 0 → u = v
| nil, _ => rfl
#align simple_graph.walk.eq_of_length_eq_zero SimpleGraph.Walk.eq_of_length_eq_zero
theorem adj_of_length_eq_one {u v : V} : ∀ {p : G.Walk u v}, p.length = 1 → G.Adj u v
| cons h nil, _ => h
@[simp]
theorem exists_length_eq_zero_iff {u v : V} : (∃ p : G.Walk u v, p.length = 0) ↔ u = v := by
constructor
· rintro ⟨p, hp⟩
exact eq_of_length_eq_zero hp
· rintro rfl
exact ⟨nil, rfl⟩
#align simple_graph.walk.exists_length_eq_zero_iff SimpleGraph.Walk.exists_length_eq_zero_iff
@[simp]
theorem length_eq_zero_iff {u : V} {p : G.Walk u u} : p.length = 0 ↔ p = nil := by cases p <;> simp
#align simple_graph.walk.length_eq_zero_iff SimpleGraph.Walk.length_eq_zero_iff
theorem getVert_append {u v w : V} (p : G.Walk u v) (q : G.Walk v w) (i : ℕ) :
(p.append q).getVert i = if i < p.length then p.getVert i else q.getVert (i - p.length) := by
induction p generalizing i with
| nil => simp
| cons h p ih => cases i <;> simp [getVert, ih, Nat.succ_lt_succ_iff]
theorem getVert_reverse {u v : V} (p : G.Walk u v) (i : ℕ) :
p.reverse.getVert i = p.getVert (p.length - i) := by
induction p with
| nil => rfl
| cons h p ih =>
simp only [reverse_cons, getVert_append, length_reverse, ih, length_cons]
split_ifs
next hi =>
rw [Nat.succ_sub hi.le]
simp [getVert]
next hi =>
obtain rfl | hi' := Nat.eq_or_lt_of_not_lt hi
· simp [getVert]
· rw [Nat.eq_add_of_sub_eq (Nat.sub_pos_of_lt hi') rfl, Nat.sub_eq_zero_of_le hi']
simp [getVert]
theorem concat_ne_nil {u v : V} (p : G.Walk u v) (h : G.Adj v u) : p.concat h ≠ nil := by
cases p <;> simp [concat]
#align simple_graph.walk.concat_ne_nil SimpleGraph.Walk.concat_ne_nil
theorem concat_inj {u v v' w : V} {p : G.Walk u v} {h : G.Adj v w} {p' : G.Walk u v'}
{h' : G.Adj v' w} (he : p.concat h = p'.concat h') : ∃ hv : v = v', p.copy rfl hv = p' := by
induction p with
| nil =>
cases p'
· exact ⟨rfl, rfl⟩
· exfalso
simp only [concat_nil, concat_cons, cons.injEq] at he
obtain ⟨rfl, he⟩ := he
simp only [heq_iff_eq] at he
exact concat_ne_nil _ _ he.symm
| cons _ _ ih =>
rw [concat_cons] at he
cases p'
· exfalso
simp only [concat_nil, cons.injEq] at he
obtain ⟨rfl, he⟩ := he
rw [heq_iff_eq] at he
exact concat_ne_nil _ _ he
· rw [concat_cons, cons.injEq] at he
obtain ⟨rfl, he⟩ := he
rw [heq_iff_eq] at he
obtain ⟨rfl, rfl⟩ := ih he
exact ⟨rfl, rfl⟩
#align simple_graph.walk.concat_inj SimpleGraph.Walk.concat_inj
def support {u v : V} : G.Walk u v → List V
| nil => [u]
| cons _ p => u :: p.support
#align simple_graph.walk.support SimpleGraph.Walk.support
def darts {u v : V} : G.Walk u v → List G.Dart
| nil => []
| cons h p => ⟨(u, _), h⟩ :: p.darts
#align simple_graph.walk.darts SimpleGraph.Walk.darts
def edges {u v : V} (p : G.Walk u v) : List (Sym2 V) := p.darts.map Dart.edge
#align simple_graph.walk.edges SimpleGraph.Walk.edges
@[simp]
theorem support_nil {u : V} : (nil : G.Walk u u).support = [u] := rfl
#align simple_graph.walk.support_nil SimpleGraph.Walk.support_nil
@[simp]
theorem support_cons {u v w : V} (h : G.Adj u v) (p : G.Walk v w) :
(cons h p).support = u :: p.support := rfl
#align simple_graph.walk.support_cons SimpleGraph.Walk.support_cons
@[simp]
theorem support_concat {u v w : V} (p : G.Walk u v) (h : G.Adj v w) :
(p.concat h).support = p.support.concat w := by
induction p <;> simp [*, concat_nil]
#align simple_graph.walk.support_concat SimpleGraph.Walk.support_concat
@[simp]
theorem support_copy {u v u' v'} (p : G.Walk u v) (hu : u = u') (hv : v = v') :
(p.copy hu hv).support = p.support := by
subst_vars
rfl
#align simple_graph.walk.support_copy SimpleGraph.Walk.support_copy
| Mathlib/Combinatorics/SimpleGraph/Connectivity.lean | 568 | 570 | theorem support_append {u v w : V} (p : G.Walk u v) (p' : G.Walk v w) :
(p.append p').support = p.support ++ p'.support.tail := by |
induction p <;> cases p' <;> simp [*]
|
import Mathlib.CategoryTheory.CofilteredSystem
import Mathlib.Combinatorics.SimpleGraph.Connectivity
import Mathlib.Data.Finite.Set
#align_import combinatorics.simple_graph.ends.defs from "leanprover-community/mathlib"@"b99e2d58a5e6861833fa8de11e51a81144258db4"
universe u
variable {V : Type u} (G : SimpleGraph V) (K L L' M : Set V)
namespace SimpleGraph
abbrev ComponentCompl :=
(G.induce Kᶜ).ConnectedComponent
#align simple_graph.component_compl SimpleGraph.ComponentCompl
variable {G} {K L M}
abbrev componentComplMk (G : SimpleGraph V) {v : V} (vK : v ∉ K) : G.ComponentCompl K :=
connectedComponentMk (G.induce Kᶜ) ⟨v, vK⟩
#align simple_graph.component_compl_mk SimpleGraph.componentComplMk
def ComponentCompl.supp (C : G.ComponentCompl K) : Set V :=
{ v : V | ∃ h : v ∉ K, G.componentComplMk h = C }
#align simple_graph.component_compl.supp SimpleGraph.ComponentCompl.supp
@[ext]
theorem ComponentCompl.supp_injective :
Function.Injective (ComponentCompl.supp : G.ComponentCompl K → Set V) := by
refine ConnectedComponent.ind₂ ?_
rintro ⟨v, hv⟩ ⟨w, hw⟩ h
simp only [Set.ext_iff, ConnectedComponent.eq, Set.mem_setOf_eq, ComponentCompl.supp] at h ⊢
exact ((h v).mp ⟨hv, Reachable.refl _⟩).choose_spec
#align simple_graph.component_compl.supp_injective SimpleGraph.ComponentCompl.supp_injective
theorem ComponentCompl.supp_inj {C D : G.ComponentCompl K} : C.supp = D.supp ↔ C = D :=
ComponentCompl.supp_injective.eq_iff
#align simple_graph.component_compl.supp_inj SimpleGraph.ComponentCompl.supp_inj
instance ComponentCompl.setLike : SetLike (G.ComponentCompl K) V where
coe := ComponentCompl.supp
coe_injective' _ _ := ComponentCompl.supp_inj.mp
#align simple_graph.component_compl.set_like SimpleGraph.ComponentCompl.setLike
@[simp]
theorem ComponentCompl.mem_supp_iff {v : V} {C : ComponentCompl G K} :
v ∈ C ↔ ∃ vK : v ∉ K, G.componentComplMk vK = C :=
Iff.rfl
#align simple_graph.component_compl.mem_supp_iff SimpleGraph.ComponentCompl.mem_supp_iff
theorem componentComplMk_mem (G : SimpleGraph V) {v : V} (vK : v ∉ K) : v ∈ G.componentComplMk vK :=
⟨vK, rfl⟩
#align simple_graph.component_compl_mk_mem SimpleGraph.componentComplMk_mem
theorem componentComplMk_eq_of_adj (G : SimpleGraph V) {v w : V} (vK : v ∉ K) (wK : w ∉ K)
(a : G.Adj v w) : G.componentComplMk vK = G.componentComplMk wK := by
rw [ConnectedComponent.eq]
apply Adj.reachable
exact a
#align simple_graph.component_compl_mk_eq_of_adj SimpleGraph.componentComplMk_eq_of_adj
instance componentCompl_nonempty_of_infinite (G : SimpleGraph V) [Infinite V] (K : Finset V) :
Nonempty (G.ComponentCompl K) :=
let ⟨_, kK⟩ := K.finite_toSet.infinite_compl.nonempty
⟨componentComplMk _ kK⟩
namespace ComponentCompl
protected def lift {β : Sort*} (f : ∀ ⦃v⦄ (_ : v ∉ K), β)
(h : ∀ ⦃v w⦄ (hv : v ∉ K) (hw : w ∉ K), G.Adj v w → f hv = f hw) : G.ComponentCompl K → β :=
ConnectedComponent.lift (fun vv => f vv.prop) fun v w p => by
induction' p with _ u v w a q ih
· rintro _
rfl
· rintro h'
exact (h u.prop v.prop a).trans (ih h'.of_cons)
#align simple_graph.component_compl.lift SimpleGraph.ComponentCompl.lift
@[elab_as_elim] -- Porting note: added
protected theorem ind {β : G.ComponentCompl K → Prop}
(f : ∀ ⦃v⦄ (hv : v ∉ K), β (G.componentComplMk hv)) : ∀ C : G.ComponentCompl K, β C := by
apply ConnectedComponent.ind
exact fun ⟨v, vnK⟩ => f vnK
#align simple_graph.component_compl.ind SimpleGraph.ComponentCompl.ind
protected abbrev coeGraph (C : ComponentCompl G K) : SimpleGraph C :=
G.induce (C : Set V)
#align simple_graph.component_compl.coe_graph SimpleGraph.ComponentCompl.coeGraph
theorem coe_inj {C D : G.ComponentCompl K} : (C : Set V) = (D : Set V) ↔ C = D :=
SetLike.coe_set_eq
#align simple_graph.component_compl.coe_inj SimpleGraph.ComponentCompl.coe_inj
@[simp]
protected theorem nonempty (C : G.ComponentCompl K) : (C : Set V).Nonempty :=
C.ind fun v vnK => ⟨v, vnK, rfl⟩
#align simple_graph.component_compl.nonempty SimpleGraph.ComponentCompl.nonempty
protected theorem exists_eq_mk (C : G.ComponentCompl K) :
∃ (v : _) (h : v ∉ K), G.componentComplMk h = C :=
C.nonempty
#align simple_graph.component_compl.exists_eq_mk SimpleGraph.ComponentCompl.exists_eq_mk
protected theorem disjoint_right (C : G.ComponentCompl K) : Disjoint K C := by
rw [Set.disjoint_iff]
exact fun v ⟨vK, vC⟩ => vC.choose vK
#align simple_graph.component_compl.disjoint_right SimpleGraph.ComponentCompl.disjoint_right
theorem not_mem_of_mem {C : G.ComponentCompl K} {c : V} (cC : c ∈ C) : c ∉ K := fun cK =>
Set.disjoint_iff.mp C.disjoint_right ⟨cK, cC⟩
#align simple_graph.component_compl.not_mem_of_mem SimpleGraph.ComponentCompl.not_mem_of_mem
protected theorem pairwise_disjoint :
Pairwise fun C D : G.ComponentCompl K => Disjoint (C : Set V) (D : Set V) := by
rintro C D ne
rw [Set.disjoint_iff]
exact fun u ⟨uC, uD⟩ => ne (uC.choose_spec.symm.trans uD.choose_spec)
#align simple_graph.component_compl.pairwise_disjoint SimpleGraph.ComponentCompl.pairwise_disjoint
theorem mem_of_adj : ∀ {C : G.ComponentCompl K} (c d : V), c ∈ C → d ∉ K → G.Adj c d → d ∈ C :=
fun {C} c d ⟨cnK, h⟩ dnK cd =>
⟨dnK, by
rw [← h, ConnectedComponent.eq]
exact Adj.reachable cd.symm⟩
#align simple_graph.component_compl.mem_of_adj SimpleGraph.ComponentCompl.mem_of_adj
theorem exists_adj_boundary_pair (Gc : G.Preconnected) (hK : K.Nonempty) :
∀ C : G.ComponentCompl K, ∃ ck : V × V, ck.1 ∈ C ∧ ck.2 ∈ K ∧ G.Adj ck.1 ck.2 := by
refine ComponentCompl.ind fun v vnK => ?_
let C : G.ComponentCompl K := G.componentComplMk vnK
let dis := Set.disjoint_iff.mp C.disjoint_right
by_contra! h
suffices Set.univ = (C : Set V) by exact dis ⟨hK.choose_spec, this ▸ Set.mem_univ hK.some⟩
symm
rw [Set.eq_univ_iff_forall]
rintro u
by_contra unC
obtain ⟨p⟩ := Gc v u
obtain ⟨⟨⟨x, y⟩, xy⟩, -, xC, ynC⟩ :=
p.exists_boundary_dart (C : Set V) (G.componentComplMk_mem vnK) unC
exact ynC (mem_of_adj x y xC (fun yK : y ∈ K => h ⟨x, y⟩ xC yK xy) xy)
#align simple_graph.component_compl.exists_adj_boundary_pair SimpleGraph.ComponentCompl.exists_adj_boundary_pair
abbrev hom (h : K ⊆ L) (C : G.ComponentCompl L) : G.ComponentCompl K :=
C.map <| induceHom Hom.id <| Set.compl_subset_compl.2 h
#align simple_graph.component_compl.hom SimpleGraph.ComponentCompl.hom
theorem subset_hom (C : G.ComponentCompl L) (h : K ⊆ L) : (C : Set V) ⊆ (C.hom h : Set V) := by
rintro c ⟨cL, rfl⟩
exact ⟨fun h' => cL (h h'), rfl⟩
#align simple_graph.component_compl.subset_hom SimpleGraph.ComponentCompl.subset_hom
theorem _root_.SimpleGraph.componentComplMk_mem_hom
(G : SimpleGraph V) {v : V} (vK : v ∉ K) (h : L ⊆ K) :
v ∈ (G.componentComplMk vK).hom h :=
subset_hom (G.componentComplMk vK) h (G.componentComplMk_mem vK)
#align simple_graph.component_compl_mk_mem_hom SimpleGraph.componentComplMk_mem_hom
theorem hom_eq_iff_le (C : G.ComponentCompl L) (h : K ⊆ L) (D : G.ComponentCompl K) :
C.hom h = D ↔ (C : Set V) ⊆ (D : Set V) :=
⟨fun h' => h' ▸ C.subset_hom h, C.ind fun _ vnL vD => (vD ⟨vnL, rfl⟩).choose_spec⟩
#align simple_graph.component_compl.hom_eq_iff_le SimpleGraph.ComponentCompl.hom_eq_iff_le
theorem hom_eq_iff_not_disjoint (C : G.ComponentCompl L) (h : K ⊆ L) (D : G.ComponentCompl K) :
C.hom h = D ↔ ¬Disjoint (C : Set V) (D : Set V) := by
rw [Set.not_disjoint_iff]
constructor
· rintro rfl
refine C.ind fun x xnL => ?_
exact ⟨x, ⟨xnL, rfl⟩, ⟨fun xK => xnL (h xK), rfl⟩⟩
· refine C.ind fun x xnL => ?_
rintro ⟨x, ⟨_, e₁⟩, _, rfl⟩
rw [← e₁]
rfl
#align simple_graph.component_compl.hom_eq_iff_not_disjoint SimpleGraph.ComponentCompl.hom_eq_iff_not_disjoint
theorem hom_refl (C : G.ComponentCompl L) : C.hom (subset_refl L) = C := by
change C.map _ = C
erw [induceHom_id G Lᶜ, ConnectedComponent.map_id]
#align simple_graph.component_compl.hom_refl SimpleGraph.ComponentCompl.hom_refl
| Mathlib/Combinatorics/SimpleGraph/Ends/Defs.lean | 212 | 216 | theorem hom_trans (C : G.ComponentCompl L) (h : K ⊆ L) (h' : M ⊆ K) :
C.hom (h'.trans h) = (C.hom h).hom h' := by |
change C.map _ = (C.map _).map _
erw [ConnectedComponent.map_comp, induceHom_comp]
rfl
|
import Mathlib.Combinatorics.SimpleGraph.Regularity.Chunk
import Mathlib.Combinatorics.SimpleGraph.Regularity.Energy
#align_import combinatorics.simple_graph.regularity.increment from "leanprover-community/mathlib"@"bf7ef0e83e5b7e6c1169e97f055e58a2e4e9d52d"
open Finset Fintype SimpleGraph SzemerediRegularity
open scoped SzemerediRegularity.Positivity
variable {α : Type*} [Fintype α] [DecidableEq α] {P : Finpartition (univ : Finset α)}
(hP : P.IsEquipartition) (G : SimpleGraph α) [DecidableRel G.Adj] (ε : ℝ)
local notation3 "m" => (card α / stepBound P.parts.card : ℕ)
namespace SzemerediRegularity
noncomputable def increment : Finpartition (univ : Finset α) :=
P.bind fun _ => chunk hP G ε
#align szemeredi_regularity.increment SzemerediRegularity.increment
open Finpartition Finpartition.IsEquipartition
variable {hP G ε}
| Mathlib/Combinatorics/SimpleGraph/Regularity/Increment.lean | 65 | 77 | theorem card_increment (hPα : P.parts.card * 16 ^ P.parts.card ≤ card α) (hPG : ¬P.IsUniform G ε) :
(increment hP G ε).parts.card = stepBound P.parts.card := by |
have hPα' : stepBound P.parts.card ≤ card α :=
(mul_le_mul_left' (pow_le_pow_left' (by norm_num) _) _).trans hPα
have hPpos : 0 < stepBound P.parts.card := stepBound_pos (nonempty_of_not_uniform hPG).card_pos
rw [increment, card_bind]
simp_rw [chunk, apply_dite Finpartition.parts, apply_dite card, sum_dite]
rw [sum_const_nat, sum_const_nat, card_attach, card_attach]; rotate_left
any_goals exact fun x hx => card_parts_equitabilise _ _ (Nat.div_pos hPα' hPpos).ne'
rw [Nat.sub_add_cancel a_add_one_le_four_pow_parts_card,
Nat.sub_add_cancel ((Nat.le_succ _).trans a_add_one_le_four_pow_parts_card), ← add_mul]
congr
rw [filter_card_add_filter_neg_card_eq_card, card_attach]
|
import Mathlib.AlgebraicTopology.SplitSimplicialObject
import Mathlib.AlgebraicTopology.DoldKan.PInfty
#align_import algebraic_topology.dold_kan.functor_gamma from "leanprover-community/mathlib"@"32a7e535287f9c73f2e4d2aef306a39190f0b504"
noncomputable section
open CategoryTheory CategoryTheory.Category CategoryTheory.Limits SimplexCategory
SimplicialObject Opposite CategoryTheory.Idempotents Simplicial DoldKan
namespace AlgebraicTopology
namespace DoldKan
variable {C : Type*} [Category C] [Preadditive C] (K K' : ChainComplex C ℕ) (f : K ⟶ K')
{Δ Δ' Δ'' : SimplexCategory}
@[nolint unusedArguments]
def Isδ₀ {Δ Δ' : SimplexCategory} (i : Δ' ⟶ Δ) [Mono i] : Prop :=
Δ.len = Δ'.len + 1 ∧ i.toOrderHom 0 ≠ 0
#align algebraic_topology.dold_kan.is_δ₀ AlgebraicTopology.DoldKan.Isδ₀
namespace Isδ₀
theorem iff {j : ℕ} {i : Fin (j + 2)} : Isδ₀ (SimplexCategory.δ i) ↔ i = 0 := by
constructor
· rintro ⟨_, h₂⟩
by_contra h
exact h₂ (Fin.succAbove_ne_zero_zero h)
· rintro rfl
exact ⟨rfl, by dsimp; exact Fin.succ_ne_zero (0 : Fin (j + 1))⟩
#align algebraic_topology.dold_kan.is_δ₀.iff AlgebraicTopology.DoldKan.Isδ₀.iff
| Mathlib/AlgebraicTopology/DoldKan/FunctorGamma.lean | 64 | 68 | theorem eq_δ₀ {n : ℕ} {i : ([n] : SimplexCategory) ⟶ [n + 1]} [Mono i] (hi : Isδ₀ i) :
i = SimplexCategory.δ 0 := by |
obtain ⟨j, rfl⟩ := SimplexCategory.eq_δ_of_mono i
rw [iff] at hi
rw [hi]
|
import Mathlib.Algebra.Polynomial.AlgebraMap
import Mathlib.Algebra.Polynomial.Reverse
import Mathlib.Algebra.Polynomial.Inductions
import Mathlib.RingTheory.Localization.Basic
#align_import data.polynomial.laurent from "leanprover-community/mathlib"@"831c494092374cfe9f50591ed0ac81a25efc5b86"
open Polynomial Function AddMonoidAlgebra Finsupp
noncomputable section
variable {R : Type*}
abbrev LaurentPolynomial (R : Type*) [Semiring R] :=
AddMonoidAlgebra R ℤ
#align laurent_polynomial LaurentPolynomial
@[nolint docBlame]
scoped[LaurentPolynomial] notation:9000 R "[T;T⁻¹]" => LaurentPolynomial R
open LaurentPolynomial
-- Porting note: `ext` no longer applies `Finsupp.ext` automatically
@[ext]
theorem LaurentPolynomial.ext [Semiring R] {p q : R[T;T⁻¹]} (h : ∀ a, p a = q a) : p = q :=
Finsupp.ext h
def Polynomial.toLaurent [Semiring R] : R[X] →+* R[T;T⁻¹] :=
(mapDomainRingHom R Int.ofNatHom).comp (toFinsuppIso R)
#align polynomial.to_laurent Polynomial.toLaurent
theorem Polynomial.toLaurent_apply [Semiring R] (p : R[X]) :
toLaurent p = p.toFinsupp.mapDomain (↑) :=
rfl
#align polynomial.to_laurent_apply Polynomial.toLaurent_apply
def Polynomial.toLaurentAlg [CommSemiring R] : R[X] →ₐ[R] R[T;T⁻¹] :=
(mapDomainAlgHom R R Int.ofNatHom).comp (toFinsuppIsoAlg R).toAlgHom
#align polynomial.to_laurent_alg Polynomial.toLaurentAlg
@[simp] lemma Polynomial.coe_toLaurentAlg [CommSemiring R] :
(toLaurentAlg : R[X] → R[T;T⁻¹]) = toLaurent :=
rfl
theorem Polynomial.toLaurentAlg_apply [CommSemiring R] (f : R[X]) : toLaurentAlg f = toLaurent f :=
rfl
#align polynomial.to_laurent_alg_apply Polynomial.toLaurentAlg_apply
namespace LaurentPolynomial
section Semiring
variable [Semiring R]
theorem single_zero_one_eq_one : (Finsupp.single 0 1 : R[T;T⁻¹]) = (1 : R[T;T⁻¹]) :=
rfl
#align laurent_polynomial.single_zero_one_eq_one LaurentPolynomial.single_zero_one_eq_one
def C : R →+* R[T;T⁻¹] :=
singleZeroRingHom
set_option linter.uppercaseLean3 false in
#align laurent_polynomial.C LaurentPolynomial.C
theorem algebraMap_apply {R A : Type*} [CommSemiring R] [Semiring A] [Algebra R A] (r : R) :
algebraMap R (LaurentPolynomial A) r = C (algebraMap R A r) :=
rfl
#align laurent_polynomial.algebra_map_apply LaurentPolynomial.algebraMap_apply
theorem C_eq_algebraMap {R : Type*} [CommSemiring R] (r : R) : C r = algebraMap R R[T;T⁻¹] r :=
rfl
set_option linter.uppercaseLean3 false in
#align laurent_polynomial.C_eq_algebra_map LaurentPolynomial.C_eq_algebraMap
theorem single_eq_C (r : R) : Finsupp.single 0 r = C r := rfl
set_option linter.uppercaseLean3 false in
#align laurent_polynomial.single_eq_C LaurentPolynomial.single_eq_C
@[simp] lemma C_apply (t : R) (n : ℤ) : C t n = if n = 0 then t else 0 := by
rw [← single_eq_C, Finsupp.single_apply]; aesop
def T (n : ℤ) : R[T;T⁻¹] :=
Finsupp.single n 1
set_option linter.uppercaseLean3 false in
#align laurent_polynomial.T LaurentPolynomial.T
@[simp] lemma T_apply (m n : ℤ) : (T n : R[T;T⁻¹]) m = if n = m then 1 else 0 :=
Finsupp.single_apply
@[simp]
theorem T_zero : (T 0 : R[T;T⁻¹]) = 1 :=
rfl
set_option linter.uppercaseLean3 false in
#align laurent_polynomial.T_zero LaurentPolynomial.T_zero
theorem T_add (m n : ℤ) : (T (m + n) : R[T;T⁻¹]) = T m * T n := by
-- Porting note: was `convert single_mul_single.symm`
simp [T, single_mul_single]
set_option linter.uppercaseLean3 false in
#align laurent_polynomial.T_add LaurentPolynomial.T_add
theorem T_sub (m n : ℤ) : (T (m - n) : R[T;T⁻¹]) = T m * T (-n) := by rw [← T_add, sub_eq_add_neg]
set_option linter.uppercaseLean3 false in
#align laurent_polynomial.T_sub LaurentPolynomial.T_sub
@[simp]
theorem T_pow (m : ℤ) (n : ℕ) : (T m ^ n : R[T;T⁻¹]) = T (n * m) := by
rw [T, T, single_pow n, one_pow, nsmul_eq_mul]
set_option linter.uppercaseLean3 false in
#align laurent_polynomial.T_pow LaurentPolynomial.T_pow
@[simp]
theorem mul_T_assoc (f : R[T;T⁻¹]) (m n : ℤ) : f * T m * T n = f * T (m + n) := by
simp [← T_add, mul_assoc]
set_option linter.uppercaseLean3 false in
#align laurent_polynomial.mul_T_assoc LaurentPolynomial.mul_T_assoc
@[simp]
theorem single_eq_C_mul_T (r : R) (n : ℤ) :
(Finsupp.single n r : R[T;T⁻¹]) = (C r * T n : R[T;T⁻¹]) := by
-- Porting note: was `convert single_mul_single.symm`
simp [C, T, single_mul_single]
set_option linter.uppercaseLean3 false in
#align laurent_polynomial.single_eq_C_mul_T LaurentPolynomial.single_eq_C_mul_T
-- This lemma locks in the right changes and is what Lean proved directly.
-- The actual `simp`-normal form of a Laurent monomial is `C a * T n`, whenever it can be reached.
@[simp]
theorem _root_.Polynomial.toLaurent_C_mul_T (n : ℕ) (r : R) :
(toLaurent (Polynomial.monomial n r) : R[T;T⁻¹]) = C r * T n :=
show Finsupp.mapDomain (↑) (monomial n r).toFinsupp = (C r * T n : R[T;T⁻¹]) by
rw [toFinsupp_monomial, Finsupp.mapDomain_single, single_eq_C_mul_T]
set_option linter.uppercaseLean3 false in
#align polynomial.to_laurent_C_mul_T Polynomial.toLaurent_C_mul_T
@[simp]
theorem _root_.Polynomial.toLaurent_C (r : R) : toLaurent (Polynomial.C r) = C r := by
convert Polynomial.toLaurent_C_mul_T 0 r
simp only [Int.ofNat_zero, T_zero, mul_one]
set_option linter.uppercaseLean3 false in
#align polynomial.to_laurent_C Polynomial.toLaurent_C
@[simp]
theorem _root_.Polynomial.toLaurent_comp_C : toLaurent (R := R) ∘ Polynomial.C = C :=
funext Polynomial.toLaurent_C
@[simp]
theorem _root_.Polynomial.toLaurent_X : (toLaurent Polynomial.X : R[T;T⁻¹]) = T 1 := by
have : (Polynomial.X : R[X]) = monomial 1 1 := by simp [← C_mul_X_pow_eq_monomial]
simp [this, Polynomial.toLaurent_C_mul_T]
set_option linter.uppercaseLean3 false in
#align polynomial.to_laurent_X Polynomial.toLaurent_X
-- @[simp] -- Porting note (#10618): simp can prove this
theorem _root_.Polynomial.toLaurent_one : (Polynomial.toLaurent : R[X] → R[T;T⁻¹]) 1 = 1 :=
map_one Polynomial.toLaurent
#align polynomial.to_laurent_one Polynomial.toLaurent_one
-- @[simp] -- Porting note (#10618): simp can prove this
theorem _root_.Polynomial.toLaurent_C_mul_eq (r : R) (f : R[X]) :
toLaurent (Polynomial.C r * f) = C r * toLaurent f := by
simp only [_root_.map_mul, Polynomial.toLaurent_C]
set_option linter.uppercaseLean3 false in
#align polynomial.to_laurent_C_mul_eq Polynomial.toLaurent_C_mul_eq
-- @[simp] -- Porting note (#10618): simp can prove this
theorem _root_.Polynomial.toLaurent_X_pow (n : ℕ) : toLaurent (X ^ n : R[X]) = T n := by
simp only [map_pow, Polynomial.toLaurent_X, T_pow, mul_one]
set_option linter.uppercaseLean3 false in
#align polynomial.to_laurent_X_pow Polynomial.toLaurent_X_pow
-- @[simp] -- Porting note (#10618): simp can prove this
| Mathlib/Algebra/Polynomial/Laurent.lean | 263 | 265 | theorem _root_.Polynomial.toLaurent_C_mul_X_pow (n : ℕ) (r : R) :
toLaurent (Polynomial.C r * X ^ n) = C r * T n := by |
simp only [_root_.map_mul, Polynomial.toLaurent_C, Polynomial.toLaurent_X_pow]
|
import Mathlib.Algebra.BigOperators.Ring.List
import Mathlib.Data.Nat.Prime
import Mathlib.Data.List.Prime
import Mathlib.Data.List.Sort
import Mathlib.Data.List.Chain
#align_import data.nat.factors from "leanprover-community/mathlib"@"008205aa645b3f194c1da47025c5f110c8406eab"
open Bool Subtype
open Nat
namespace Nat
attribute [instance 0] instBEqNat
def factors : ℕ → List ℕ
| 0 => []
| 1 => []
| k + 2 =>
let m := minFac (k + 2)
m :: factors ((k + 2) / m)
decreasing_by show (k + 2) / m < (k + 2); exact factors_lemma
#align nat.factors Nat.factors
@[simp]
theorem factors_zero : factors 0 = [] := by rw [factors]
#align nat.factors_zero Nat.factors_zero
@[simp]
theorem factors_one : factors 1 = [] := by rw [factors]
#align nat.factors_one Nat.factors_one
@[simp]
theorem factors_two : factors 2 = [2] := by simp [factors]
theorem prime_of_mem_factors {n : ℕ} : ∀ {p : ℕ}, (h : p ∈ factors n) → Prime p := by
match n with
| 0 => simp
| 1 => simp
| k + 2 =>
intro p h
let m := minFac (k + 2)
have : (k + 2) / m < (k + 2) := factors_lemma
have h₁ : p = m ∨ p ∈ factors ((k + 2) / m) :=
List.mem_cons.1 (by rwa [factors] at h)
exact Or.casesOn h₁ (fun h₂ => h₂.symm ▸ minFac_prime (by simp)) prime_of_mem_factors
#align nat.prime_of_mem_factors Nat.prime_of_mem_factors
theorem pos_of_mem_factors {n p : ℕ} (h : p ∈ factors n) : 0 < p :=
Prime.pos (prime_of_mem_factors h)
#align nat.pos_of_mem_factors Nat.pos_of_mem_factors
theorem prod_factors : ∀ {n}, n ≠ 0 → List.prod (factors n) = n
| 0 => by simp
| 1 => by simp
| k + 2 => fun _ =>
let m := minFac (k + 2)
have : (k + 2) / m < (k + 2) := factors_lemma
show (factors (k + 2)).prod = (k + 2) by
have h₁ : (k + 2) / m ≠ 0 := fun h => by
have : (k + 2) = 0 * m := (Nat.div_eq_iff_eq_mul_left (minFac_pos _) (minFac_dvd _)).1 h
rw [zero_mul] at this; exact (show k + 2 ≠ 0 by simp) this
rw [factors, List.prod_cons, prod_factors h₁, Nat.mul_div_cancel' (minFac_dvd _)]
#align nat.prod_factors Nat.prod_factors
theorem factors_prime {p : ℕ} (hp : Nat.Prime p) : p.factors = [p] := by
have : p = p - 2 + 2 := (tsub_eq_iff_eq_add_of_le hp.two_le).mp rfl
rw [this, Nat.factors]
simp only [Eq.symm this]
have : Nat.minFac p = p := (Nat.prime_def_minFac.mp hp).2
simp only [this, Nat.factors, Nat.div_self (Nat.Prime.pos hp)]
#align nat.factors_prime Nat.factors_prime
theorem factors_chain {n : ℕ} :
∀ {a}, (∀ p, Prime p → p ∣ n → a ≤ p) → List.Chain (· ≤ ·) a (factors n) := by
match n with
| 0 => simp
| 1 => simp
| k + 2 =>
intro a h
let m := minFac (k + 2)
have : (k + 2) / m < (k + 2) := factors_lemma
rw [factors]
refine List.Chain.cons ((le_minFac.2 h).resolve_left (by simp)) (factors_chain ?_)
exact fun p pp d => minFac_le_of_dvd pp.two_le (d.trans <| div_dvd_of_dvd <| minFac_dvd _)
#align nat.factors_chain Nat.factors_chain
theorem factors_chain_2 (n) : List.Chain (· ≤ ·) 2 (factors n) :=
factors_chain fun _ pp _ => pp.two_le
#align nat.factors_chain_2 Nat.factors_chain_2
theorem factors_chain' (n) : List.Chain' (· ≤ ·) (factors n) :=
@List.Chain'.tail _ _ (_ :: _) (factors_chain_2 _)
#align nat.factors_chain' Nat.factors_chain'
theorem factors_sorted (n : ℕ) : List.Sorted (· ≤ ·) (factors n) :=
List.chain'_iff_pairwise.1 (factors_chain' _)
#align nat.factors_sorted Nat.factors_sorted
| Mathlib/Data/Nat/Factors.lean | 120 | 121 | theorem factors_add_two (n : ℕ) :
factors (n + 2) = minFac (n + 2) :: factors ((n + 2) / minFac (n + 2)) := by | rw [factors]
|
import Mathlib.Combinatorics.SimpleGraph.Regularity.Increment
#align_import combinatorics.simple_graph.regularity.lemma from "leanprover-community/mathlib"@"1d4d3ca5ec44693640c4f5e407a6b611f77accc8"
open Finpartition Finset Fintype Function SzemerediRegularity
variable {α : Type*} [DecidableEq α] [Fintype α] (G : SimpleGraph α) [DecidableRel G.Adj] {ε : ℝ}
{l : ℕ}
| Mathlib/Combinatorics/SimpleGraph/Regularity/Lemma.lean | 74 | 151 | theorem szemeredi_regularity (hε : 0 < ε) (hl : l ≤ card α) :
∃ P : Finpartition univ,
P.IsEquipartition ∧ l ≤ P.parts.card ∧ P.parts.card ≤ bound ε l ∧ P.IsUniform G ε := by |
obtain hα | hα := le_total (card α) (bound ε l)
-- If `card α ≤ bound ε l`, then the partition into singletons is acceptable.
· refine ⟨⊥, bot_isEquipartition _, ?_⟩
rw [card_bot, card_univ]
exact ⟨hl, hα, bot_isUniform _ hε⟩
-- Else, let's start from a dummy equipartition of size `initialBound ε l`.
let t := initialBound ε l
have htα : t ≤ (univ : Finset α).card :=
(initialBound_le_bound _ _).trans (by rwa [Finset.card_univ])
obtain ⟨dum, hdum₁, hdum₂⟩ :=
exists_equipartition_card_eq (univ : Finset α) (initialBound_pos _ _).ne' htα
obtain hε₁ | hε₁ := le_total 1 ε
-- If `ε ≥ 1`, then this dummy equipartition is `ε`-uniform, so we're done.
· exact ⟨dum, hdum₁, (le_initialBound ε l).trans hdum₂.ge,
hdum₂.le.trans (initialBound_le_bound ε l), (dum.isUniform_one G).mono hε₁⟩
-- Else, set up the induction on energy. We phrase it through the existence for each `i` of an
-- equipartition of size bounded by `stepBound^[i] (initialBound ε l)` and which is either
-- `ε`-uniform or has energy at least `ε ^ 5 / 4 * i`.
have : Nonempty α := by
rw [← Fintype.card_pos_iff]
exact (bound_pos _ _).trans_le hα
suffices h : ∀ i, ∃ P : Finpartition (univ : Finset α), P.IsEquipartition ∧ t ≤ P.parts.card ∧
P.parts.card ≤ stepBound^[i] t ∧ (P.IsUniform G ε ∨ ε ^ 5 / 4 * i ≤ P.energy G) by
-- For `i > 4 / ε ^ 5` we know that the partition we get can't have energy `≥ ε ^ 5 / 4 * i > 1`,
-- so it must instead be `ε`-uniform and we won.
obtain ⟨P, hP₁, hP₂, hP₃, hP₄⟩ := h (⌊4 / ε ^ 5⌋₊ + 1)
refine ⟨P, hP₁, (le_initialBound _ _).trans hP₂, hP₃.trans ?_,
hP₄.resolve_right fun hPenergy => lt_irrefl (1 : ℝ) ?_⟩
· rw [iterate_succ_apply']
exact mul_le_mul_left' (pow_le_pow_left (by norm_num) (by norm_num) _) _
calc
(1 : ℝ) = ε ^ 5 / ↑4 * (↑4 / ε ^ 5) := by
rw [mul_comm, div_mul_div_cancel 4 (pow_pos hε 5).ne']; norm_num
_ < ε ^ 5 / 4 * (⌊4 / ε ^ 5⌋₊ + 1) :=
((mul_lt_mul_left <| by positivity).2 (Nat.lt_floor_add_one _))
_ ≤ (P.energy G : ℝ) := by rwa [← Nat.cast_add_one]
_ ≤ 1 := mod_cast P.energy_le_one G
-- Let's do the actual induction.
intro i
induction' i with i ih
-- For `i = 0`, the dummy equipartition is enough.
· refine ⟨dum, hdum₁, hdum₂.ge, hdum₂.le, Or.inr ?_⟩
rw [Nat.cast_zero, mul_zero]
exact mod_cast dum.energy_nonneg G
-- For the induction step at `i + 1`, find `P` the equipartition at `i`.
obtain ⟨P, hP₁, hP₂, hP₃, hP₄⟩ := ih
by_cases huniform : P.IsUniform G ε
-- If `P` is already uniform, then no need to break it up further. We can just return `P` again.
· refine ⟨P, hP₁, hP₂, ?_, Or.inl huniform⟩
rw [iterate_succ_apply']
exact hP₃.trans (le_stepBound _)
-- Else, `P` must instead have energy at least `ε ^ 5 / 4 * i`.
replace hP₄ := hP₄.resolve_left huniform
-- We gather a few numerical facts.
have hεl' : 100 ≤ 4 ^ P.parts.card * ε ^ 5 :=
(hundred_lt_pow_initialBound_mul hε l).le.trans
(mul_le_mul_of_nonneg_right (pow_le_pow_right (by norm_num) hP₂) <| by positivity)
have hi : (i : ℝ) ≤ 4 / ε ^ 5 := by
have hi : ε ^ 5 / 4 * ↑i ≤ 1 := hP₄.trans (mod_cast P.energy_le_one G)
rw [div_mul_eq_mul_div, div_le_iff (show (0 : ℝ) < 4 by norm_num)] at hi
set_option tactic.skipAssignedInstances false in norm_num at hi
rwa [le_div_iff' (pow_pos hε _)]
have hsize : P.parts.card ≤ stepBound^[⌊4 / ε ^ 5⌋₊] t :=
hP₃.trans (monotone_iterate_of_id_le le_stepBound (Nat.le_floor hi) _)
have hPα : P.parts.card * 16 ^ P.parts.card ≤ card α :=
(Nat.mul_le_mul hsize (Nat.pow_le_pow_of_le_right (by norm_num) hsize)).trans hα
-- We return the increment equipartition of `P`, which has energy `≥ ε ^ 5 / 4 * (i + 1)`.
refine ⟨increment hP₁ G ε, increment_isEquipartition hP₁ G ε, ?_, ?_, Or.inr <| le_trans ?_ <|
energy_increment hP₁ ((seven_le_initialBound ε l).trans hP₂) hεl' hPα huniform hε.le hε₁⟩
· rw [card_increment hPα huniform]
exact hP₂.trans (le_stepBound _)
· rw [card_increment hPα huniform, iterate_succ_apply']
exact stepBound_mono hP₃
· rw [Nat.cast_succ, mul_add, mul_one]
exact add_le_add_right hP₄ _
|
import Mathlib.Data.Fintype.Option
import Mathlib.Data.Fintype.Prod
import Mathlib.Data.Fintype.Pi
import Mathlib.Data.Vector.Basic
import Mathlib.Data.PFun
import Mathlib.Logic.Function.Iterate
import Mathlib.Order.Basic
import Mathlib.Tactic.ApplyFun
#align_import computability.turing_machine from "leanprover-community/mathlib"@"4c19a16e4b705bf135cf9a80ac18fcc99c438514"
assert_not_exists MonoidWithZero
open Relation
open Nat (iterate)
open Function (update iterate_succ iterate_succ_apply iterate_succ' iterate_succ_apply'
iterate_zero_apply)
namespace Turing
def BlankExtends {Γ} [Inhabited Γ] (l₁ l₂ : List Γ) : Prop :=
∃ n, l₂ = l₁ ++ List.replicate n default
#align turing.blank_extends Turing.BlankExtends
@[refl]
theorem BlankExtends.refl {Γ} [Inhabited Γ] (l : List Γ) : BlankExtends l l :=
⟨0, by simp⟩
#align turing.blank_extends.refl Turing.BlankExtends.refl
@[trans]
theorem BlankExtends.trans {Γ} [Inhabited Γ] {l₁ l₂ l₃ : List Γ} :
BlankExtends l₁ l₂ → BlankExtends l₂ l₃ → BlankExtends l₁ l₃ := by
rintro ⟨i, rfl⟩ ⟨j, rfl⟩
exact ⟨i + j, by simp [List.replicate_add]⟩
#align turing.blank_extends.trans Turing.BlankExtends.trans
theorem BlankExtends.below_of_le {Γ} [Inhabited Γ] {l l₁ l₂ : List Γ} :
BlankExtends l l₁ → BlankExtends l l₂ → l₁.length ≤ l₂.length → BlankExtends l₁ l₂ := by
rintro ⟨i, rfl⟩ ⟨j, rfl⟩ h; use j - i
simp only [List.length_append, Nat.add_le_add_iff_left, List.length_replicate] at h
simp only [← List.replicate_add, Nat.add_sub_cancel' h, List.append_assoc]
#align turing.blank_extends.below_of_le Turing.BlankExtends.below_of_le
def BlankExtends.above {Γ} [Inhabited Γ] {l l₁ l₂ : List Γ} (h₁ : BlankExtends l l₁)
(h₂ : BlankExtends l l₂) : { l' // BlankExtends l₁ l' ∧ BlankExtends l₂ l' } :=
if h : l₁.length ≤ l₂.length then ⟨l₂, h₁.below_of_le h₂ h, BlankExtends.refl _⟩
else ⟨l₁, BlankExtends.refl _, h₂.below_of_le h₁ (le_of_not_ge h)⟩
#align turing.blank_extends.above Turing.BlankExtends.above
theorem BlankExtends.above_of_le {Γ} [Inhabited Γ] {l l₁ l₂ : List Γ} :
BlankExtends l₁ l → BlankExtends l₂ l → l₁.length ≤ l₂.length → BlankExtends l₁ l₂ := by
rintro ⟨i, rfl⟩ ⟨j, e⟩ h; use i - j
refine List.append_cancel_right (e.symm.trans ?_)
rw [List.append_assoc, ← List.replicate_add, Nat.sub_add_cancel]
apply_fun List.length at e
simp only [List.length_append, List.length_replicate] at e
rwa [← Nat.add_le_add_iff_left, e, Nat.add_le_add_iff_right]
#align turing.blank_extends.above_of_le Turing.BlankExtends.above_of_le
def BlankRel {Γ} [Inhabited Γ] (l₁ l₂ : List Γ) : Prop :=
BlankExtends l₁ l₂ ∨ BlankExtends l₂ l₁
#align turing.blank_rel Turing.BlankRel
@[refl]
theorem BlankRel.refl {Γ} [Inhabited Γ] (l : List Γ) : BlankRel l l :=
Or.inl (BlankExtends.refl _)
#align turing.blank_rel.refl Turing.BlankRel.refl
@[symm]
theorem BlankRel.symm {Γ} [Inhabited Γ] {l₁ l₂ : List Γ} : BlankRel l₁ l₂ → BlankRel l₂ l₁ :=
Or.symm
#align turing.blank_rel.symm Turing.BlankRel.symm
@[trans]
theorem BlankRel.trans {Γ} [Inhabited Γ] {l₁ l₂ l₃ : List Γ} :
BlankRel l₁ l₂ → BlankRel l₂ l₃ → BlankRel l₁ l₃ := by
rintro (h₁ | h₁) (h₂ | h₂)
· exact Or.inl (h₁.trans h₂)
· rcases le_total l₁.length l₃.length with h | h
· exact Or.inl (h₁.above_of_le h₂ h)
· exact Or.inr (h₂.above_of_le h₁ h)
· rcases le_total l₁.length l₃.length with h | h
· exact Or.inl (h₁.below_of_le h₂ h)
· exact Or.inr (h₂.below_of_le h₁ h)
· exact Or.inr (h₂.trans h₁)
#align turing.blank_rel.trans Turing.BlankRel.trans
def BlankRel.above {Γ} [Inhabited Γ] {l₁ l₂ : List Γ} (h : BlankRel l₁ l₂) :
{ l // BlankExtends l₁ l ∧ BlankExtends l₂ l } := by
refine
if hl : l₁.length ≤ l₂.length then ⟨l₂, Or.elim h id fun h' ↦ ?_, BlankExtends.refl _⟩
else ⟨l₁, BlankExtends.refl _, Or.elim h (fun h' ↦ ?_) id⟩
· exact (BlankExtends.refl _).above_of_le h' hl
· exact (BlankExtends.refl _).above_of_le h' (le_of_not_ge hl)
#align turing.blank_rel.above Turing.BlankRel.above
def BlankRel.below {Γ} [Inhabited Γ] {l₁ l₂ : List Γ} (h : BlankRel l₁ l₂) :
{ l // BlankExtends l l₁ ∧ BlankExtends l l₂ } := by
refine
if hl : l₁.length ≤ l₂.length then ⟨l₁, BlankExtends.refl _, Or.elim h id fun h' ↦ ?_⟩
else ⟨l₂, Or.elim h (fun h' ↦ ?_) id, BlankExtends.refl _⟩
· exact (BlankExtends.refl _).above_of_le h' hl
· exact (BlankExtends.refl _).above_of_le h' (le_of_not_ge hl)
#align turing.blank_rel.below Turing.BlankRel.below
theorem BlankRel.equivalence (Γ) [Inhabited Γ] : Equivalence (@BlankRel Γ _) :=
⟨BlankRel.refl, @BlankRel.symm _ _, @BlankRel.trans _ _⟩
#align turing.blank_rel.equivalence Turing.BlankRel.equivalence
def BlankRel.setoid (Γ) [Inhabited Γ] : Setoid (List Γ) :=
⟨_, BlankRel.equivalence _⟩
#align turing.blank_rel.setoid Turing.BlankRel.setoid
def ListBlank (Γ) [Inhabited Γ] :=
Quotient (BlankRel.setoid Γ)
#align turing.list_blank Turing.ListBlank
instance ListBlank.inhabited {Γ} [Inhabited Γ] : Inhabited (ListBlank Γ) :=
⟨Quotient.mk'' []⟩
#align turing.list_blank.inhabited Turing.ListBlank.inhabited
instance ListBlank.hasEmptyc {Γ} [Inhabited Γ] : EmptyCollection (ListBlank Γ) :=
⟨Quotient.mk'' []⟩
#align turing.list_blank.has_emptyc Turing.ListBlank.hasEmptyc
-- Porting note: Removed `@[elab_as_elim]`
protected abbrev ListBlank.liftOn {Γ} [Inhabited Γ] {α} (l : ListBlank Γ) (f : List Γ → α)
(H : ∀ a b, BlankExtends a b → f a = f b) : α :=
l.liftOn' f <| by rintro a b (h | h) <;> [exact H _ _ h; exact (H _ _ h).symm]
#align turing.list_blank.lift_on Turing.ListBlank.liftOn
def ListBlank.mk {Γ} [Inhabited Γ] : List Γ → ListBlank Γ :=
Quotient.mk''
#align turing.list_blank.mk Turing.ListBlank.mk
@[elab_as_elim]
protected theorem ListBlank.induction_on {Γ} [Inhabited Γ] {p : ListBlank Γ → Prop}
(q : ListBlank Γ) (h : ∀ a, p (ListBlank.mk a)) : p q :=
Quotient.inductionOn' q h
#align turing.list_blank.induction_on Turing.ListBlank.induction_on
def ListBlank.head {Γ} [Inhabited Γ] (l : ListBlank Γ) : Γ := by
apply l.liftOn List.headI
rintro a _ ⟨i, rfl⟩
cases a
· cases i <;> rfl
rfl
#align turing.list_blank.head Turing.ListBlank.head
@[simp]
theorem ListBlank.head_mk {Γ} [Inhabited Γ] (l : List Γ) :
ListBlank.head (ListBlank.mk l) = l.headI :=
rfl
#align turing.list_blank.head_mk Turing.ListBlank.head_mk
def ListBlank.tail {Γ} [Inhabited Γ] (l : ListBlank Γ) : ListBlank Γ := by
apply l.liftOn (fun l ↦ ListBlank.mk l.tail)
rintro a _ ⟨i, rfl⟩
refine Quotient.sound' (Or.inl ?_)
cases a
· cases' i with i <;> [exact ⟨0, rfl⟩; exact ⟨i, rfl⟩]
exact ⟨i, rfl⟩
#align turing.list_blank.tail Turing.ListBlank.tail
@[simp]
theorem ListBlank.tail_mk {Γ} [Inhabited Γ] (l : List Γ) :
ListBlank.tail (ListBlank.mk l) = ListBlank.mk l.tail :=
rfl
#align turing.list_blank.tail_mk Turing.ListBlank.tail_mk
def ListBlank.cons {Γ} [Inhabited Γ] (a : Γ) (l : ListBlank Γ) : ListBlank Γ := by
apply l.liftOn (fun l ↦ ListBlank.mk (List.cons a l))
rintro _ _ ⟨i, rfl⟩
exact Quotient.sound' (Or.inl ⟨i, rfl⟩)
#align turing.list_blank.cons Turing.ListBlank.cons
@[simp]
theorem ListBlank.cons_mk {Γ} [Inhabited Γ] (a : Γ) (l : List Γ) :
ListBlank.cons a (ListBlank.mk l) = ListBlank.mk (a :: l) :=
rfl
#align turing.list_blank.cons_mk Turing.ListBlank.cons_mk
@[simp]
theorem ListBlank.head_cons {Γ} [Inhabited Γ] (a : Γ) : ∀ l : ListBlank Γ, (l.cons a).head = a :=
Quotient.ind' fun _ ↦ rfl
#align turing.list_blank.head_cons Turing.ListBlank.head_cons
@[simp]
theorem ListBlank.tail_cons {Γ} [Inhabited Γ] (a : Γ) : ∀ l : ListBlank Γ, (l.cons a).tail = l :=
Quotient.ind' fun _ ↦ rfl
#align turing.list_blank.tail_cons Turing.ListBlank.tail_cons
@[simp]
theorem ListBlank.cons_head_tail {Γ} [Inhabited Γ] : ∀ l : ListBlank Γ, l.tail.cons l.head = l := by
apply Quotient.ind'
refine fun l ↦ Quotient.sound' (Or.inr ?_)
cases l
· exact ⟨1, rfl⟩
· rfl
#align turing.list_blank.cons_head_tail Turing.ListBlank.cons_head_tail
theorem ListBlank.exists_cons {Γ} [Inhabited Γ] (l : ListBlank Γ) :
∃ a l', l = ListBlank.cons a l' :=
⟨_, _, (ListBlank.cons_head_tail _).symm⟩
#align turing.list_blank.exists_cons Turing.ListBlank.exists_cons
def ListBlank.nth {Γ} [Inhabited Γ] (l : ListBlank Γ) (n : ℕ) : Γ := by
apply l.liftOn (fun l ↦ List.getI l n)
rintro l _ ⟨i, rfl⟩
cases' lt_or_le n _ with h h
· rw [List.getI_append _ _ _ h]
rw [List.getI_eq_default _ h]
rcases le_or_lt _ n with h₂ | h₂
· rw [List.getI_eq_default _ h₂]
rw [List.getI_eq_get _ h₂, List.get_append_right' h, List.get_replicate]
#align turing.list_blank.nth Turing.ListBlank.nth
@[simp]
theorem ListBlank.nth_mk {Γ} [Inhabited Γ] (l : List Γ) (n : ℕ) :
(ListBlank.mk l).nth n = l.getI n :=
rfl
#align turing.list_blank.nth_mk Turing.ListBlank.nth_mk
@[simp]
theorem ListBlank.nth_zero {Γ} [Inhabited Γ] (l : ListBlank Γ) : l.nth 0 = l.head := by
conv => lhs; rw [← ListBlank.cons_head_tail l]
exact Quotient.inductionOn' l.tail fun l ↦ rfl
#align turing.list_blank.nth_zero Turing.ListBlank.nth_zero
@[simp]
theorem ListBlank.nth_succ {Γ} [Inhabited Γ] (l : ListBlank Γ) (n : ℕ) :
l.nth (n + 1) = l.tail.nth n := by
conv => lhs; rw [← ListBlank.cons_head_tail l]
exact Quotient.inductionOn' l.tail fun l ↦ rfl
#align turing.list_blank.nth_succ Turing.ListBlank.nth_succ
@[ext]
theorem ListBlank.ext {Γ} [i : Inhabited Γ] {L₁ L₂ : ListBlank Γ} :
(∀ i, L₁.nth i = L₂.nth i) → L₁ = L₂ := by
refine ListBlank.induction_on L₁ fun l₁ ↦ ListBlank.induction_on L₂ fun l₂ H ↦ ?_
wlog h : l₁.length ≤ l₂.length
· cases le_total l₁.length l₂.length <;> [skip; symm] <;> apply this <;> try assumption
intro
rw [H]
refine Quotient.sound' (Or.inl ⟨l₂.length - l₁.length, ?_⟩)
refine List.ext_get ?_ fun i h h₂ ↦ Eq.symm ?_
· simp only [Nat.add_sub_cancel' h, List.length_append, List.length_replicate]
simp only [ListBlank.nth_mk] at H
cases' lt_or_le i l₁.length with h' h'
· simp only [List.get_append _ h', List.get?_eq_get h, List.get?_eq_get h',
← List.getI_eq_get _ h, ← List.getI_eq_get _ h', H]
· simp only [List.get_append_right' h', List.get_replicate, List.get?_eq_get h,
List.get?_len_le h', ← List.getI_eq_default _ h', H, List.getI_eq_get _ h]
#align turing.list_blank.ext Turing.ListBlank.ext
@[simp]
def ListBlank.modifyNth {Γ} [Inhabited Γ] (f : Γ → Γ) : ℕ → ListBlank Γ → ListBlank Γ
| 0, L => L.tail.cons (f L.head)
| n + 1, L => (L.tail.modifyNth f n).cons L.head
#align turing.list_blank.modify_nth Turing.ListBlank.modifyNth
theorem ListBlank.nth_modifyNth {Γ} [Inhabited Γ] (f : Γ → Γ) (n i) (L : ListBlank Γ) :
(L.modifyNth f n).nth i = if i = n then f (L.nth i) else L.nth i := by
induction' n with n IH generalizing i L
· cases i <;> simp only [ListBlank.nth_zero, if_true, ListBlank.head_cons, ListBlank.modifyNth,
ListBlank.nth_succ, if_false, ListBlank.tail_cons, Nat.zero_eq]
· cases i
· rw [if_neg (Nat.succ_ne_zero _).symm]
simp only [ListBlank.nth_zero, ListBlank.head_cons, ListBlank.modifyNth, Nat.zero_eq]
· simp only [IH, ListBlank.modifyNth, ListBlank.nth_succ, ListBlank.tail_cons, Nat.succ.injEq]
#align turing.list_blank.nth_modify_nth Turing.ListBlank.nth_modifyNth
structure PointedMap.{u, v} (Γ : Type u) (Γ' : Type v) [Inhabited Γ] [Inhabited Γ'] :
Type max u v where
f : Γ → Γ'
map_pt' : f default = default
#align turing.pointed_map Turing.PointedMap
instance {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] : Inhabited (PointedMap Γ Γ') :=
⟨⟨default, rfl⟩⟩
instance {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] : CoeFun (PointedMap Γ Γ') fun _ ↦ Γ → Γ' :=
⟨PointedMap.f⟩
-- @[simp] -- Porting note (#10685): dsimp can prove this
theorem PointedMap.mk_val {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] (f : Γ → Γ') (pt) :
(PointedMap.mk f pt : Γ → Γ') = f :=
rfl
#align turing.pointed_map.mk_val Turing.PointedMap.mk_val
@[simp]
theorem PointedMap.map_pt {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] (f : PointedMap Γ Γ') :
f default = default :=
PointedMap.map_pt' _
#align turing.pointed_map.map_pt Turing.PointedMap.map_pt
@[simp]
theorem PointedMap.headI_map {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] (f : PointedMap Γ Γ')
(l : List Γ) : (l.map f).headI = f l.headI := by
cases l <;> [exact (PointedMap.map_pt f).symm; rfl]
#align turing.pointed_map.head_map Turing.PointedMap.headI_map
def ListBlank.map {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] (f : PointedMap Γ Γ') (l : ListBlank Γ) :
ListBlank Γ' := by
apply l.liftOn (fun l ↦ ListBlank.mk (List.map f l))
rintro l _ ⟨i, rfl⟩; refine Quotient.sound' (Or.inl ⟨i, ?_⟩)
simp only [PointedMap.map_pt, List.map_append, List.map_replicate]
#align turing.list_blank.map Turing.ListBlank.map
@[simp]
theorem ListBlank.map_mk {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] (f : PointedMap Γ Γ') (l : List Γ) :
(ListBlank.mk l).map f = ListBlank.mk (l.map f) :=
rfl
#align turing.list_blank.map_mk Turing.ListBlank.map_mk
@[simp]
theorem ListBlank.head_map {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] (f : PointedMap Γ Γ')
(l : ListBlank Γ) : (l.map f).head = f l.head := by
conv => lhs; rw [← ListBlank.cons_head_tail l]
exact Quotient.inductionOn' l fun a ↦ rfl
#align turing.list_blank.head_map Turing.ListBlank.head_map
@[simp]
theorem ListBlank.tail_map {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] (f : PointedMap Γ Γ')
(l : ListBlank Γ) : (l.map f).tail = l.tail.map f := by
conv => lhs; rw [← ListBlank.cons_head_tail l]
exact Quotient.inductionOn' l fun a ↦ rfl
#align turing.list_blank.tail_map Turing.ListBlank.tail_map
@[simp]
theorem ListBlank.map_cons {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] (f : PointedMap Γ Γ')
(l : ListBlank Γ) (a : Γ) : (l.cons a).map f = (l.map f).cons (f a) := by
refine (ListBlank.cons_head_tail _).symm.trans ?_
simp only [ListBlank.head_map, ListBlank.head_cons, ListBlank.tail_map, ListBlank.tail_cons]
#align turing.list_blank.map_cons Turing.ListBlank.map_cons
@[simp]
| Mathlib/Computability/TuringMachine.lean | 418 | 426 | theorem ListBlank.nth_map {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] (f : PointedMap Γ Γ')
(l : ListBlank Γ) (n : ℕ) : (l.map f).nth n = f (l.nth n) := by |
refine l.inductionOn fun l ↦ ?_
-- Porting note: Added `suffices` to get `simp` to work.
suffices ((mk l).map f).nth n = f ((mk l).nth n) by exact this
simp only [List.get?_map, ListBlank.map_mk, ListBlank.nth_mk, List.getI_eq_iget_get?]
cases l.get? n
· exact f.2.symm
· rfl
|
import Mathlib.Analysis.InnerProductSpace.PiL2
import Mathlib.LinearAlgebra.Matrix.Block
#align_import analysis.inner_product_space.gram_schmidt_ortho from "leanprover-community/mathlib"@"1a4df69ca1a9a0e5e26bfe12e2b92814216016d0"
open Finset Submodule FiniteDimensional
variable (𝕜 : Type*) {E : Type*} [RCLike 𝕜] [NormedAddCommGroup E] [InnerProductSpace 𝕜 E]
variable {ι : Type*} [LinearOrder ι] [LocallyFiniteOrderBot ι] [IsWellOrder ι (· < ·)]
attribute [local instance] IsWellOrder.toHasWellFounded
local notation "⟪" x ", " y "⟫" => @inner 𝕜 _ _ x y
noncomputable def gramSchmidt [IsWellOrder ι (· < ·)] (f : ι → E) (n : ι) : E :=
f n - ∑ i : Iio n, orthogonalProjection (𝕜 ∙ gramSchmidt f i) (f n)
termination_by n
decreasing_by exact mem_Iio.1 i.2
#align gram_schmidt gramSchmidt
theorem gramSchmidt_def (f : ι → E) (n : ι) :
gramSchmidt 𝕜 f n = f n - ∑ i ∈ Iio n, orthogonalProjection (𝕜 ∙ gramSchmidt 𝕜 f i) (f n) := by
rw [← sum_attach, attach_eq_univ, gramSchmidt]
#align gram_schmidt_def gramSchmidt_def
theorem gramSchmidt_def' (f : ι → E) (n : ι) :
f n = gramSchmidt 𝕜 f n + ∑ i ∈ Iio n, orthogonalProjection (𝕜 ∙ gramSchmidt 𝕜 f i) (f n) := by
rw [gramSchmidt_def, sub_add_cancel]
#align gram_schmidt_def' gramSchmidt_def'
theorem gramSchmidt_def'' (f : ι → E) (n : ι) :
f n = gramSchmidt 𝕜 f n + ∑ i ∈ Iio n,
(⟪gramSchmidt 𝕜 f i, f n⟫ / (‖gramSchmidt 𝕜 f i‖ : 𝕜) ^ 2) • gramSchmidt 𝕜 f i := by
convert gramSchmidt_def' 𝕜 f n
rw [orthogonalProjection_singleton, RCLike.ofReal_pow]
#align gram_schmidt_def'' gramSchmidt_def''
@[simp]
| Mathlib/Analysis/InnerProductSpace/GramSchmidtOrtho.lean | 76 | 78 | theorem gramSchmidt_zero {ι : Type*} [LinearOrder ι] [LocallyFiniteOrder ι] [OrderBot ι]
[IsWellOrder ι (· < ·)] (f : ι → E) : gramSchmidt 𝕜 f ⊥ = f ⊥ := by |
rw [gramSchmidt_def, Iio_eq_Ico, Finset.Ico_self, Finset.sum_empty, sub_zero]
|
import Mathlib.Probability.IdentDistrib
import Mathlib.MeasureTheory.Integral.DominatedConvergence
import Mathlib.Analysis.SpecificLimits.FloorPow
import Mathlib.Analysis.PSeries
import Mathlib.Analysis.Asymptotics.SpecificAsymptotics
#align_import probability.strong_law from "leanprover-community/mathlib"@"f2ce6086713c78a7f880485f7917ea547a215982"
noncomputable section
open MeasureTheory Filter Finset Asymptotics
open Set (indicator)
open scoped Topology MeasureTheory ProbabilityTheory ENNReal NNReal
namespace ProbabilityTheory
section Truncation
variable {α : Type*}
def truncation (f : α → ℝ) (A : ℝ) :=
indicator (Set.Ioc (-A) A) id ∘ f
#align probability_theory.truncation ProbabilityTheory.truncation
variable {m : MeasurableSpace α} {μ : Measure α} {f : α → ℝ}
theorem _root_.MeasureTheory.AEStronglyMeasurable.truncation (hf : AEStronglyMeasurable f μ)
{A : ℝ} : AEStronglyMeasurable (truncation f A) μ := by
apply AEStronglyMeasurable.comp_aemeasurable _ hf.aemeasurable
exact (stronglyMeasurable_id.indicator measurableSet_Ioc).aestronglyMeasurable
#align measure_theory.ae_strongly_measurable.truncation MeasureTheory.AEStronglyMeasurable.truncation
theorem abs_truncation_le_bound (f : α → ℝ) (A : ℝ) (x : α) : |truncation f A x| ≤ |A| := by
simp only [truncation, Set.indicator, Set.mem_Icc, id, Function.comp_apply]
split_ifs with h
· exact abs_le_abs h.2 (neg_le.2 h.1.le)
· simp [abs_nonneg]
#align probability_theory.abs_truncation_le_bound ProbabilityTheory.abs_truncation_le_bound
@[simp]
theorem truncation_zero (f : α → ℝ) : truncation f 0 = 0 := by simp [truncation]; rfl
#align probability_theory.truncation_zero ProbabilityTheory.truncation_zero
theorem abs_truncation_le_abs_self (f : α → ℝ) (A : ℝ) (x : α) : |truncation f A x| ≤ |f x| := by
simp only [truncation, indicator, Set.mem_Icc, id, Function.comp_apply]
split_ifs
· exact le_rfl
· simp [abs_nonneg]
#align probability_theory.abs_truncation_le_abs_self ProbabilityTheory.abs_truncation_le_abs_self
theorem truncation_eq_self {f : α → ℝ} {A : ℝ} {x : α} (h : |f x| < A) :
truncation f A x = f x := by
simp only [truncation, indicator, Set.mem_Icc, id, Function.comp_apply, ite_eq_left_iff]
intro H
apply H.elim
simp [(abs_lt.1 h).1, (abs_lt.1 h).2.le]
#align probability_theory.truncation_eq_self ProbabilityTheory.truncation_eq_self
theorem truncation_eq_of_nonneg {f : α → ℝ} {A : ℝ} (h : ∀ x, 0 ≤ f x) :
truncation f A = indicator (Set.Ioc 0 A) id ∘ f := by
ext x
rcases (h x).lt_or_eq with (hx | hx)
· simp only [truncation, indicator, hx, Set.mem_Ioc, id, Function.comp_apply, true_and_iff]
by_cases h'x : f x ≤ A
· have : -A < f x := by linarith [h x]
simp only [this, true_and_iff]
· simp only [h'x, and_false_iff]
· simp only [truncation, indicator, hx, id, Function.comp_apply, ite_self]
#align probability_theory.truncation_eq_of_nonneg ProbabilityTheory.truncation_eq_of_nonneg
theorem truncation_nonneg {f : α → ℝ} (A : ℝ) {x : α} (h : 0 ≤ f x) : 0 ≤ truncation f A x :=
Set.indicator_apply_nonneg fun _ => h
#align probability_theory.truncation_nonneg ProbabilityTheory.truncation_nonneg
theorem _root_.MeasureTheory.AEStronglyMeasurable.memℒp_truncation [IsFiniteMeasure μ]
(hf : AEStronglyMeasurable f μ) {A : ℝ} {p : ℝ≥0∞} : Memℒp (truncation f A) p μ :=
Memℒp.of_bound hf.truncation |A| (eventually_of_forall fun _ => abs_truncation_le_bound _ _ _)
#align measure_theory.ae_strongly_measurable.mem_ℒp_truncation MeasureTheory.AEStronglyMeasurable.memℒp_truncation
theorem _root_.MeasureTheory.AEStronglyMeasurable.integrable_truncation [IsFiniteMeasure μ]
(hf : AEStronglyMeasurable f μ) {A : ℝ} : Integrable (truncation f A) μ := by
rw [← memℒp_one_iff_integrable]; exact hf.memℒp_truncation
#align measure_theory.ae_strongly_measurable.integrable_truncation MeasureTheory.AEStronglyMeasurable.integrable_truncation
theorem moment_truncation_eq_intervalIntegral (hf : AEStronglyMeasurable f μ) {A : ℝ} (hA : 0 ≤ A)
{n : ℕ} (hn : n ≠ 0) : ∫ x, truncation f A x ^ n ∂μ = ∫ y in -A..A, y ^ n ∂Measure.map f μ := by
have M : MeasurableSet (Set.Ioc (-A) A) := measurableSet_Ioc
change ∫ x, (fun z => indicator (Set.Ioc (-A) A) id z ^ n) (f x) ∂μ = _
rw [← integral_map (f := fun z => _ ^ n) hf.aemeasurable, intervalIntegral.integral_of_le,
← integral_indicator M]
· simp only [indicator, zero_pow hn, id, ite_pow]
· linarith
· exact ((measurable_id.indicator M).pow_const n).aestronglyMeasurable
#align probability_theory.moment_truncation_eq_interval_integral ProbabilityTheory.moment_truncation_eq_intervalIntegral
| Mathlib/Probability/StrongLaw.lean | 151 | 175 | theorem moment_truncation_eq_intervalIntegral_of_nonneg (hf : AEStronglyMeasurable f μ) {A : ℝ}
{n : ℕ} (hn : n ≠ 0) (h'f : 0 ≤ f) :
∫ x, truncation f A x ^ n ∂μ = ∫ y in (0)..A, y ^ n ∂Measure.map f μ := by |
have M : MeasurableSet (Set.Ioc 0 A) := measurableSet_Ioc
have M' : MeasurableSet (Set.Ioc A 0) := measurableSet_Ioc
rw [truncation_eq_of_nonneg h'f]
change ∫ x, (fun z => indicator (Set.Ioc 0 A) id z ^ n) (f x) ∂μ = _
rcases le_or_lt 0 A with (hA | hA)
· rw [← integral_map (f := fun z => _ ^ n) hf.aemeasurable, intervalIntegral.integral_of_le hA,
← integral_indicator M]
· simp only [indicator, zero_pow hn, id, ite_pow]
· exact ((measurable_id.indicator M).pow_const n).aestronglyMeasurable
· rw [← integral_map (f := fun z => _ ^ n) hf.aemeasurable, intervalIntegral.integral_of_ge hA.le,
← integral_indicator M']
· simp only [Set.Ioc_eq_empty_of_le hA.le, zero_pow hn, Set.indicator_empty, integral_zero,
zero_eq_neg]
apply integral_eq_zero_of_ae
have : ∀ᵐ x ∂Measure.map f μ, (0 : ℝ) ≤ x :=
(ae_map_iff hf.aemeasurable measurableSet_Ici).2 (eventually_of_forall h'f)
filter_upwards [this] with x hx
simp only [indicator, Set.mem_Ioc, Pi.zero_apply, ite_eq_right_iff, and_imp]
intro _ h''x
have : x = 0 := by linarith
simp [this, zero_pow hn]
· exact ((measurable_id.indicator M).pow_const n).aestronglyMeasurable
|
import Mathlib.Algebra.BigOperators.Associated
import Mathlib.Algebra.Order.Ring.Abs
import Mathlib.Data.Nat.Choose.Sum
import Mathlib.Data.Nat.Choose.Dvd
import Mathlib.Data.Nat.Prime
#align_import number_theory.primorial from "leanprover-community/mathlib"@"0a0ec35061ed9960bf0e7ffb0335f44447b58977"
open Finset
open Nat
open Nat
def primorial (n : ℕ) : ℕ :=
∏ p ∈ filter Nat.Prime (range (n + 1)), p
#align primorial primorial
local notation x "#" => primorial x
theorem primorial_pos (n : ℕ) : 0 < n# :=
prod_pos fun _p hp ↦ (mem_filter.1 hp).2.pos
#align primorial_pos primorial_pos
| Mathlib/NumberTheory/Primorial.lean | 45 | 48 | theorem primorial_succ {n : ℕ} (hn1 : n ≠ 1) (hn : Odd n) : (n + 1)# = n# := by |
refine prod_congr ?_ fun _ _ ↦ rfl
rw [range_succ, filter_insert, if_neg fun h ↦ odd_iff_not_even.mp hn _]
exact fun h ↦ h.even_sub_one <| mt succ.inj hn1
|
import Mathlib.Data.Finsupp.Multiset
import Mathlib.Data.Nat.GCD.BigOperators
import Mathlib.Data.Nat.PrimeFin
import Mathlib.NumberTheory.Padics.PadicVal
import Mathlib.Order.Interval.Finset.Nat
#align_import data.nat.factorization.basic from "leanprover-community/mathlib"@"f694c7dead66f5d4c80f446c796a5aad14707f0e"
-- Workaround for lean4#2038
attribute [-instance] instBEqNat
open Nat Finset List Finsupp
namespace Nat
variable {a b m n p : ℕ}
def factorization (n : ℕ) : ℕ →₀ ℕ where
support := n.primeFactors
toFun p := if p.Prime then padicValNat p n else 0
mem_support_toFun := by simp [not_or]; aesop
#align nat.factorization Nat.factorization
@[simp] lemma support_factorization (n : ℕ) : (factorization n).support = n.primeFactors := rfl
theorem factorization_def (n : ℕ) {p : ℕ} (pp : p.Prime) : n.factorization p = padicValNat p n := by
simpa [factorization] using absurd pp
#align nat.factorization_def Nat.factorization_def
@[simp]
theorem factors_count_eq {n p : ℕ} : n.factors.count p = n.factorization p := by
rcases n.eq_zero_or_pos with (rfl | hn0)
· simp [factorization, count]
if pp : p.Prime then ?_ else
rw [count_eq_zero_of_not_mem (mt prime_of_mem_factors pp)]
simp [factorization, pp]
simp only [factorization_def _ pp]
apply _root_.le_antisymm
· rw [le_padicValNat_iff_replicate_subperm_factors pp hn0.ne']
exact List.le_count_iff_replicate_sublist.mp le_rfl |>.subperm
· rw [← lt_add_one_iff, lt_iff_not_ge, ge_iff_le,
le_padicValNat_iff_replicate_subperm_factors pp hn0.ne']
intro h
have := h.count_le p
simp at this
#align nat.factors_count_eq Nat.factors_count_eq
theorem factorization_eq_factors_multiset (n : ℕ) :
n.factorization = Multiset.toFinsupp (n.factors : Multiset ℕ) := by
ext p
simp
#align nat.factorization_eq_factors_multiset Nat.factorization_eq_factors_multiset
theorem multiplicity_eq_factorization {n p : ℕ} (pp : p.Prime) (hn : n ≠ 0) :
multiplicity p n = n.factorization p := by
simp [factorization, pp, padicValNat_def' pp.ne_one hn.bot_lt]
#align nat.multiplicity_eq_factorization Nat.multiplicity_eq_factorization
@[simp]
theorem factorization_prod_pow_eq_self {n : ℕ} (hn : n ≠ 0) : n.factorization.prod (· ^ ·) = n := by
rw [factorization_eq_factors_multiset n]
simp only [← prod_toMultiset, factorization, Multiset.prod_coe, Multiset.toFinsupp_toMultiset]
exact prod_factors hn
#align nat.factorization_prod_pow_eq_self Nat.factorization_prod_pow_eq_self
theorem eq_of_factorization_eq {a b : ℕ} (ha : a ≠ 0) (hb : b ≠ 0)
(h : ∀ p : ℕ, a.factorization p = b.factorization p) : a = b :=
eq_of_perm_factors ha hb (by simpa only [List.perm_iff_count, factors_count_eq] using h)
#align nat.eq_of_factorization_eq Nat.eq_of_factorization_eq
theorem factorization_inj : Set.InjOn factorization { x : ℕ | x ≠ 0 } := fun a ha b hb h =>
eq_of_factorization_eq ha hb fun p => by simp [h]
#align nat.factorization_inj Nat.factorization_inj
@[simp]
theorem factorization_zero : factorization 0 = 0 := by ext; simp [factorization]
#align nat.factorization_zero Nat.factorization_zero
@[simp]
theorem factorization_one : factorization 1 = 0 := by ext; simp [factorization]
#align nat.factorization_one Nat.factorization_one
#noalign nat.support_factorization
#align nat.factor_iff_mem_factorization Nat.mem_primeFactors_iff_mem_factors
#align nat.prime_of_mem_factorization Nat.prime_of_mem_primeFactors
#align nat.pos_of_mem_factorization Nat.pos_of_mem_primeFactors
#align nat.le_of_mem_factorization Nat.le_of_mem_primeFactors
theorem factorization_eq_zero_iff (n p : ℕ) :
n.factorization p = 0 ↔ ¬p.Prime ∨ ¬p ∣ n ∨ n = 0 := by
simp_rw [← not_mem_support_iff, support_factorization, mem_primeFactors, not_and_or, not_ne_iff]
#align nat.factorization_eq_zero_iff Nat.factorization_eq_zero_iff
@[simp]
theorem factorization_eq_zero_of_non_prime (n : ℕ) {p : ℕ} (hp : ¬p.Prime) :
n.factorization p = 0 := by simp [factorization_eq_zero_iff, hp]
#align nat.factorization_eq_zero_of_non_prime Nat.factorization_eq_zero_of_non_prime
theorem factorization_eq_zero_of_not_dvd {n p : ℕ} (h : ¬p ∣ n) : n.factorization p = 0 := by
simp [factorization_eq_zero_iff, h]
#align nat.factorization_eq_zero_of_not_dvd Nat.factorization_eq_zero_of_not_dvd
theorem factorization_eq_zero_of_lt {n p : ℕ} (h : n < p) : n.factorization p = 0 :=
Finsupp.not_mem_support_iff.mp (mt le_of_mem_primeFactors (not_le_of_lt h))
#align nat.factorization_eq_zero_of_lt Nat.factorization_eq_zero_of_lt
@[simp]
theorem factorization_zero_right (n : ℕ) : n.factorization 0 = 0 :=
factorization_eq_zero_of_non_prime _ not_prime_zero
#align nat.factorization_zero_right Nat.factorization_zero_right
@[simp]
theorem factorization_one_right (n : ℕ) : n.factorization 1 = 0 :=
factorization_eq_zero_of_non_prime _ not_prime_one
#align nat.factorization_one_right Nat.factorization_one_right
theorem dvd_of_factorization_pos {n p : ℕ} (hn : n.factorization p ≠ 0) : p ∣ n :=
dvd_of_mem_factors <| mem_primeFactors_iff_mem_factors.1 <| mem_support_iff.2 hn
#align nat.dvd_of_factorization_pos Nat.dvd_of_factorization_pos
theorem Prime.factorization_pos_of_dvd {n p : ℕ} (hp : p.Prime) (hn : n ≠ 0) (h : p ∣ n) :
0 < n.factorization p := by
rwa [← factors_count_eq, count_pos_iff_mem, mem_factors_iff_dvd hn hp]
#align nat.prime.factorization_pos_of_dvd Nat.Prime.factorization_pos_of_dvd
theorem factorization_eq_zero_of_remainder {p r : ℕ} (i : ℕ) (hr : ¬p ∣ r) :
(p * i + r).factorization p = 0 := by
apply factorization_eq_zero_of_not_dvd
rwa [← Nat.dvd_add_iff_right (Dvd.intro i rfl)]
#align nat.factorization_eq_zero_of_remainder Nat.factorization_eq_zero_of_remainder
| Mathlib/Data/Nat/Factorization/Basic.lean | 176 | 184 | theorem factorization_eq_zero_iff_remainder {p r : ℕ} (i : ℕ) (pp : p.Prime) (hr0 : r ≠ 0) :
¬p ∣ r ↔ (p * i + r).factorization p = 0 := by |
refine ⟨factorization_eq_zero_of_remainder i, fun h => ?_⟩
rw [factorization_eq_zero_iff] at h
contrapose! h
refine ⟨pp, ?_, ?_⟩
· rwa [← Nat.dvd_add_iff_right (dvd_mul_right p i)]
· contrapose! hr0
exact (add_eq_zero_iff.mp hr0).2
|
import Mathlib.Algebra.CharP.LocalRing
import Mathlib.RingTheory.Ideal.Quotient
import Mathlib.Tactic.FieldSimp
#align_import algebra.char_p.mixed_char_zero from "leanprover-community/mathlib"@"70fd9563a21e7b963887c9360bd29b2393e6225a"
variable (R : Type*) [CommRing R]
class MixedCharZero (p : ℕ) : Prop where
[toCharZero : CharZero R]
charP_quotient : ∃ I : Ideal R, I ≠ ⊤ ∧ CharP (R ⧸ I) p
#align mixed_char_zero MixedCharZero
namespace MixedCharZero
theorem reduce_to_p_prime {P : Prop} :
(∀ p > 0, MixedCharZero R p → P) ↔ ∀ p : ℕ, p.Prime → MixedCharZero R p → P := by
constructor
· intro h q q_prime q_mixedChar
exact h q (Nat.Prime.pos q_prime) q_mixedChar
· intro h q q_pos q_mixedChar
rcases q_mixedChar.charP_quotient with ⟨I, hI_ne_top, _⟩
-- Krull's Thm: There exists a prime ideal `P` such that `I ≤ P`
rcases Ideal.exists_le_maximal I hI_ne_top with ⟨M, hM_max, h_IM⟩
let r := ringChar (R ⧸ M)
have r_pos : r ≠ 0 := by
have q_zero :=
congr_arg (Ideal.Quotient.factor I M h_IM) (CharP.cast_eq_zero (R ⧸ I) q)
simp only [map_natCast, map_zero] at q_zero
apply ne_zero_of_dvd_ne_zero (ne_of_gt q_pos)
exact (CharP.cast_eq_zero_iff (R ⧸ M) r q).mp q_zero
have r_prime : Nat.Prime r :=
or_iff_not_imp_right.1 (CharP.char_is_prime_or_zero (R ⧸ M) r) r_pos
apply h r r_prime
have : CharZero R := q_mixedChar.toCharZero
exact ⟨⟨M, hM_max.ne_top, ringChar.of_eq rfl⟩⟩
#align mixed_char_zero.reduce_to_p_prime MixedCharZero.reduce_to_p_prime
| Mathlib/Algebra/CharP/MixedCharZero.lean | 112 | 136 | theorem reduce_to_maximal_ideal {p : ℕ} (hp : Nat.Prime p) :
(∃ I : Ideal R, I ≠ ⊤ ∧ CharP (R ⧸ I) p) ↔ ∃ I : Ideal R, I.IsMaximal ∧ CharP (R ⧸ I) p := by |
constructor
· intro g
rcases g with ⟨I, ⟨hI_not_top, _⟩⟩
-- Krull's Thm: There exists a prime ideal `M` such that `I ≤ M`.
rcases Ideal.exists_le_maximal I hI_not_top with ⟨M, ⟨hM_max, hM_ge⟩⟩
use M
constructor
· exact hM_max
· cases CharP.exists (R ⧸ M) with
| intro r hr =>
-- Porting note: This is odd. Added `have hr := hr`.
-- Without this it seems that lean does not find `hr` as an instance.
have hr := hr
convert hr
have r_dvd_p : r ∣ p := by
rw [← CharP.cast_eq_zero_iff (R ⧸ M) r p]
convert congr_arg (Ideal.Quotient.factor I M hM_ge) (CharP.cast_eq_zero (R ⧸ I) p)
symm
apply (Nat.Prime.eq_one_or_self_of_dvd hp r r_dvd_p).resolve_left
exact CharP.char_ne_one (R ⧸ M) r
· intro ⟨I, hI_max, h_charP⟩
use I
exact ⟨Ideal.IsMaximal.ne_top hI_max, h_charP⟩
|
import Mathlib.Analysis.Calculus.FDeriv.Linear
import Mathlib.Analysis.Calculus.FDeriv.Comp
#align_import analysis.calculus.fderiv.prod from "leanprover-community/mathlib"@"e354e865255654389cc46e6032160238df2e0f40"
open Filter Asymptotics ContinuousLinearMap Set Metric
open scoped Classical
open Topology NNReal Filter Asymptotics ENNReal
noncomputable section
section
variable {𝕜 : Type*} [NontriviallyNormedField 𝕜]
variable {E : Type*} [NormedAddCommGroup E] [NormedSpace 𝕜 E]
variable {F : Type*} [NormedAddCommGroup F] [NormedSpace 𝕜 F]
variable {G : Type*} [NormedAddCommGroup G] [NormedSpace 𝕜 G]
variable {G' : Type*} [NormedAddCommGroup G'] [NormedSpace 𝕜 G']
variable {f f₀ f₁ g : E → F}
variable {f' f₀' f₁' g' : E →L[𝕜] F}
variable (e : E →L[𝕜] F)
variable {x : E}
variable {s t : Set E}
variable {L L₁ L₂ : Filter E}
section CartesianProduct
section Pi
variable {ι : Type*} [Fintype ι] {F' : ι → Type*} [∀ i, NormedAddCommGroup (F' i)]
[∀ i, NormedSpace 𝕜 (F' i)] {φ : ∀ i, E → F' i} {φ' : ∀ i, E →L[𝕜] F' i} {Φ : E → ∀ i, F' i}
{Φ' : E →L[𝕜] ∀ i, F' i}
@[simp]
theorem hasStrictFDerivAt_pi' :
HasStrictFDerivAt Φ Φ' x ↔ ∀ i, HasStrictFDerivAt (fun x => Φ x i) ((proj i).comp Φ') x := by
simp only [HasStrictFDerivAt, ContinuousLinearMap.coe_pi]
exact isLittleO_pi
#align has_strict_fderiv_at_pi' hasStrictFDerivAt_pi'
@[fun_prop]
theorem hasStrictFDerivAt_pi'' (hφ : ∀ i, HasStrictFDerivAt (fun x => Φ x i) ((proj i).comp Φ') x) :
HasStrictFDerivAt Φ Φ' x := hasStrictFDerivAt_pi'.2 hφ
@[fun_prop]
theorem hasStrictFDerivAt_apply (i : ι) (f : ∀ i, F' i) :
HasStrictFDerivAt (𝕜:=𝕜) (fun f : ∀ i, F' i => f i) (proj i) f := by
let id' := ContinuousLinearMap.id 𝕜 (∀ i, F' i)
have h := ((hasStrictFDerivAt_pi'
(Φ := fun (f : ∀ i, F' i) (i' : ι) => f i') (Φ':=id') (x:=f))).1
have h' : comp (proj i) id' = proj i := by rfl
rw [← h']; apply h; apply hasStrictFDerivAt_id
@[simp 1100] -- Porting note: increased priority to make lint happy
theorem hasStrictFDerivAt_pi :
HasStrictFDerivAt (fun x i => φ i x) (ContinuousLinearMap.pi φ') x ↔
∀ i, HasStrictFDerivAt (φ i) (φ' i) x :=
hasStrictFDerivAt_pi'
#align has_strict_fderiv_at_pi hasStrictFDerivAt_pi
@[simp]
theorem hasFDerivAtFilter_pi' :
HasFDerivAtFilter Φ Φ' x L ↔
∀ i, HasFDerivAtFilter (fun x => Φ x i) ((proj i).comp Φ') x L := by
simp only [hasFDerivAtFilter_iff_isLittleO, ContinuousLinearMap.coe_pi]
exact isLittleO_pi
#align has_fderiv_at_filter_pi' hasFDerivAtFilter_pi'
theorem hasFDerivAtFilter_pi :
HasFDerivAtFilter (fun x i => φ i x) (ContinuousLinearMap.pi φ') x L ↔
∀ i, HasFDerivAtFilter (φ i) (φ' i) x L :=
hasFDerivAtFilter_pi'
#align has_fderiv_at_filter_pi hasFDerivAtFilter_pi
@[simp]
theorem hasFDerivAt_pi' :
HasFDerivAt Φ Φ' x ↔ ∀ i, HasFDerivAt (fun x => Φ x i) ((proj i).comp Φ') x :=
hasFDerivAtFilter_pi'
#align has_fderiv_at_pi' hasFDerivAt_pi'
@[fun_prop]
theorem hasFDerivAt_pi'' (hφ : ∀ i, HasFDerivAt (fun x => Φ x i) ((proj i).comp Φ') x) :
HasFDerivAt Φ Φ' x := hasFDerivAt_pi'.2 hφ
@[fun_prop]
theorem hasFDerivAt_apply (i : ι) (f : ∀ i, F' i) :
HasFDerivAt (𝕜:=𝕜) (fun f : ∀ i, F' i => f i) (proj i) f := by
apply HasStrictFDerivAt.hasFDerivAt
apply hasStrictFDerivAt_apply
theorem hasFDerivAt_pi :
HasFDerivAt (fun x i => φ i x) (ContinuousLinearMap.pi φ') x ↔
∀ i, HasFDerivAt (φ i) (φ' i) x :=
hasFDerivAtFilter_pi
#align has_fderiv_at_pi hasFDerivAt_pi
@[simp]
theorem hasFDerivWithinAt_pi' :
HasFDerivWithinAt Φ Φ' s x ↔ ∀ i, HasFDerivWithinAt (fun x => Φ x i) ((proj i).comp Φ') s x :=
hasFDerivAtFilter_pi'
#align has_fderiv_within_at_pi' hasFDerivWithinAt_pi'
@[fun_prop]
theorem hasFDerivWithinAt_pi''
(hφ : ∀ i, HasFDerivWithinAt (fun x => Φ x i) ((proj i).comp Φ') s x) :
HasFDerivWithinAt Φ Φ' s x := hasFDerivWithinAt_pi'.2 hφ
@[fun_prop]
theorem hasFDerivWithinAt_apply (i : ι) (f : ∀ i, F' i) (s' : Set (∀ i, F' i)) :
HasFDerivWithinAt (𝕜:=𝕜) (fun f : ∀ i, F' i => f i) (proj i) s' f := by
let id' := ContinuousLinearMap.id 𝕜 (∀ i, F' i)
have h := ((hasFDerivWithinAt_pi'
(Φ := fun (f : ∀ i, F' i) (i' : ι) => f i') (Φ':=id') (x:=f) (s:=s'))).1
have h' : comp (proj i) id' = proj i := by rfl
rw [← h']; apply h; apply hasFDerivWithinAt_id
theorem hasFDerivWithinAt_pi :
HasFDerivWithinAt (fun x i => φ i x) (ContinuousLinearMap.pi φ') s x ↔
∀ i, HasFDerivWithinAt (φ i) (φ' i) s x :=
hasFDerivAtFilter_pi
#align has_fderiv_within_at_pi hasFDerivWithinAt_pi
@[simp]
theorem differentiableWithinAt_pi :
DifferentiableWithinAt 𝕜 Φ s x ↔ ∀ i, DifferentiableWithinAt 𝕜 (fun x => Φ x i) s x :=
⟨fun h i => (hasFDerivWithinAt_pi'.1 h.hasFDerivWithinAt i).differentiableWithinAt, fun h =>
(hasFDerivWithinAt_pi.2 fun i => (h i).hasFDerivWithinAt).differentiableWithinAt⟩
#align differentiable_within_at_pi differentiableWithinAt_pi
@[fun_prop]
theorem differentiableWithinAt_pi'' (hφ : ∀ i, DifferentiableWithinAt 𝕜 (fun x => Φ x i) s x) :
DifferentiableWithinAt 𝕜 Φ s x := differentiableWithinAt_pi.2 hφ
@[fun_prop]
theorem differentiableWithinAt_apply (i : ι) (f : ∀ i, F' i) (s' : Set (∀ i, F' i)) :
DifferentiableWithinAt (𝕜:=𝕜) (fun f : ∀ i, F' i => f i) s' f := by
apply HasFDerivWithinAt.differentiableWithinAt
fun_prop
@[simp]
theorem differentiableAt_pi : DifferentiableAt 𝕜 Φ x ↔ ∀ i, DifferentiableAt 𝕜 (fun x => Φ x i) x :=
⟨fun h i => (hasFDerivAt_pi'.1 h.hasFDerivAt i).differentiableAt, fun h =>
(hasFDerivAt_pi.2 fun i => (h i).hasFDerivAt).differentiableAt⟩
#align differentiable_at_pi differentiableAt_pi
@[fun_prop]
theorem differentiableAt_pi'' (hφ : ∀ i, DifferentiableAt 𝕜 (fun x => Φ x i) x) :
DifferentiableAt 𝕜 Φ x := differentiableAt_pi.2 hφ
@[fun_prop]
theorem differentiableAt_apply (i : ι) (f : ∀ i, F' i) :
DifferentiableAt (𝕜:=𝕜) (fun f : ∀ i, F' i => f i) f := by
have h := ((differentiableAt_pi (𝕜:=𝕜)
(Φ := fun (f : ∀ i, F' i) (i' : ι) => f i') (x:=f))).1
apply h; apply differentiableAt_id
theorem differentiableOn_pi : DifferentiableOn 𝕜 Φ s ↔ ∀ i, DifferentiableOn 𝕜 (fun x => Φ x i) s :=
⟨fun h i x hx => differentiableWithinAt_pi.1 (h x hx) i, fun h x hx =>
differentiableWithinAt_pi.2 fun i => h i x hx⟩
#align differentiable_on_pi differentiableOn_pi
@[fun_prop]
theorem differentiableOn_pi'' (hφ : ∀ i, DifferentiableOn 𝕜 (fun x => Φ x i) s) :
DifferentiableOn 𝕜 Φ s := differentiableOn_pi.2 hφ
@[fun_prop]
| Mathlib/Analysis/Calculus/FDeriv/Prod.lean | 532 | 536 | theorem differentiableOn_apply (i : ι) (s' : Set (∀ i, F' i)) :
DifferentiableOn (𝕜:=𝕜) (fun f : ∀ i, F' i => f i) s' := by |
have h := ((differentiableOn_pi (𝕜:=𝕜)
(Φ := fun (f : ∀ i, F' i) (i' : ι) => f i') (s:=s'))).1
apply h; apply differentiableOn_id
|
import Mathlib.CategoryTheory.Monoidal.Types.Symmetric
import Mathlib.CategoryTheory.Monoidal.Types.Coyoneda
import Mathlib.CategoryTheory.Monoidal.Center
import Mathlib.Tactic.ApplyFun
#align_import category_theory.enriched.basic from "leanprover-community/mathlib"@"95a87616d63b3cb49d3fe678d416fbe9c4217bf4"
universe w v u₁ u₂ u₃
noncomputable section
namespace CategoryTheory
open Opposite
open MonoidalCategory
variable (V : Type v) [Category.{w} V] [MonoidalCategory V]
class EnrichedCategory (C : Type u₁) where
Hom : C → C → V
id (X : C) : 𝟙_ V ⟶ Hom X X
comp (X Y Z : C) : Hom X Y ⊗ Hom Y Z ⟶ Hom X Z
id_comp (X Y : C) : (λ_ (Hom X Y)).inv ≫ id X ▷ _ ≫ comp X X Y = 𝟙 _ := by aesop_cat
comp_id (X Y : C) : (ρ_ (Hom X Y)).inv ≫ _ ◁ id Y ≫ comp X Y Y = 𝟙 _ := by aesop_cat
assoc (W X Y Z : C) : (α_ _ _ _).inv ≫ comp W X Y ▷ _ ≫ comp W Y Z =
_ ◁ comp X Y Z ≫ comp W X Z := by aesop_cat
#align category_theory.enriched_category CategoryTheory.EnrichedCategory
notation X " ⟶[" V "] " Y:10 => (EnrichedCategory.Hom X Y : V)
variable {C : Type u₁} [EnrichedCategory V C]
def eId (X : C) : 𝟙_ V ⟶ X ⟶[V] X :=
EnrichedCategory.id X
#align category_theory.e_id CategoryTheory.eId
def eComp (X Y Z : C) : ((X ⟶[V] Y) ⊗ Y ⟶[V] Z) ⟶ X ⟶[V] Z :=
EnrichedCategory.comp X Y Z
#align category_theory.e_comp CategoryTheory.eComp
@[reassoc (attr := simp)]
theorem e_id_comp (X Y : C) :
(λ_ (X ⟶[V] Y)).inv ≫ eId V X ▷ _ ≫ eComp V X X Y = 𝟙 (X ⟶[V] Y) :=
EnrichedCategory.id_comp X Y
#align category_theory.e_id_comp CategoryTheory.e_id_comp
@[reassoc (attr := simp)]
theorem e_comp_id (X Y : C) :
(ρ_ (X ⟶[V] Y)).inv ≫ _ ◁ eId V Y ≫ eComp V X Y Y = 𝟙 (X ⟶[V] Y) :=
EnrichedCategory.comp_id X Y
#align category_theory.e_comp_id CategoryTheory.e_comp_id
@[reassoc (attr := simp)]
theorem e_assoc (W X Y Z : C) :
(α_ _ _ _).inv ≫ eComp V W X Y ▷ _ ≫ eComp V W Y Z =
_ ◁ eComp V X Y Z ≫ eComp V W X Z :=
EnrichedCategory.assoc W X Y Z
#align category_theory.e_assoc CategoryTheory.e_assoc
@[reassoc]
| Mathlib/CategoryTheory/Enriched/Basic.lean | 98 | 101 | theorem e_assoc' (W X Y Z : C) :
(α_ _ _ _).hom ≫ _ ◁ eComp V X Y Z ≫ eComp V W X Z =
eComp V W X Y ▷ _ ≫ eComp V W Y Z := by |
rw [← e_assoc V W X Y Z, Iso.hom_inv_id_assoc]
|
import Mathlib.FieldTheory.RatFunc.Basic
import Mathlib.RingTheory.EuclideanDomain
import Mathlib.RingTheory.Localization.FractionRing
import Mathlib.RingTheory.Polynomial.Content
noncomputable section
universe u
variable {K : Type u}
namespace RatFunc
section Eval
open scoped Classical
open scoped nonZeroDivisors Polynomial
open RatFunc
section Domain
variable [CommRing K] [IsDomain K]
def C : K →+* RatFunc K := algebraMap _ _
set_option linter.uppercaseLean3 false in #align ratfunc.C RatFunc.C
@[simp]
theorem algebraMap_eq_C : algebraMap K (RatFunc K) = C :=
rfl
set_option linter.uppercaseLean3 false in #align ratfunc.algebra_map_eq_C RatFunc.algebraMap_eq_C
@[simp]
theorem algebraMap_C (a : K) : algebraMap K[X] (RatFunc K) (Polynomial.C a) = C a :=
rfl
set_option linter.uppercaseLean3 false in #align ratfunc.algebra_map_C RatFunc.algebraMap_C
@[simp]
theorem algebraMap_comp_C : (algebraMap K[X] (RatFunc K)).comp Polynomial.C = C :=
rfl
set_option linter.uppercaseLean3 false in #align ratfunc.algebra_map_comp_C RatFunc.algebraMap_comp_C
| Mathlib/FieldTheory/RatFunc/AsPolynomial.lean | 61 | 62 | theorem smul_eq_C_mul (r : K) (x : RatFunc K) : r • x = C r * x := by |
rw [Algebra.smul_def, algebraMap_eq_C]
|
import Mathlib.Init.Data.Sigma.Lex
import Mathlib.Data.Prod.Lex
import Mathlib.Data.Sigma.Lex
import Mathlib.Order.Antichain
import Mathlib.Order.OrderIsoNat
import Mathlib.Order.WellFounded
import Mathlib.Tactic.TFAE
#align_import order.well_founded_set from "leanprover-community/mathlib"@"2c84c2c5496117349007d97104e7bbb471381592"
variable {ι α β γ : Type*} {π : ι → Type*}
namespace Set
def WellFoundedOn (s : Set α) (r : α → α → Prop) : Prop :=
WellFounded fun a b : s => r a b
#align set.well_founded_on Set.WellFoundedOn
@[simp]
theorem wellFoundedOn_empty (r : α → α → Prop) : WellFoundedOn ∅ r :=
wellFounded_of_isEmpty _
#align set.well_founded_on_empty Set.wellFoundedOn_empty
def PartiallyWellOrderedOn (s : Set α) (r : α → α → Prop) : Prop :=
∀ f : ℕ → α, (∀ n, f n ∈ s) → ∃ m n : ℕ, m < n ∧ r (f m) (f n)
#align set.partially_well_ordered_on Set.PartiallyWellOrderedOn
section PartiallyWellOrderedOn
variable {r : α → α → Prop} {r' : β → β → Prop} {f : α → β} {s : Set α} {t : Set α} {a : α}
theorem PartiallyWellOrderedOn.mono (ht : t.PartiallyWellOrderedOn r) (h : s ⊆ t) :
s.PartiallyWellOrderedOn r := fun f hf => ht f fun n => h <| hf n
#align set.partially_well_ordered_on.mono Set.PartiallyWellOrderedOn.mono
@[simp]
theorem partiallyWellOrderedOn_empty (r : α → α → Prop) : PartiallyWellOrderedOn ∅ r := fun _ h =>
(h 0).elim
#align set.partially_well_ordered_on_empty Set.partiallyWellOrderedOn_empty
theorem PartiallyWellOrderedOn.union (hs : s.PartiallyWellOrderedOn r)
(ht : t.PartiallyWellOrderedOn r) : (s ∪ t).PartiallyWellOrderedOn r := by
rintro f hf
rcases Nat.exists_subseq_of_forall_mem_union f hf with ⟨g, hgs | hgt⟩
· rcases hs _ hgs with ⟨m, n, hlt, hr⟩
exact ⟨g m, g n, g.strictMono hlt, hr⟩
· rcases ht _ hgt with ⟨m, n, hlt, hr⟩
exact ⟨g m, g n, g.strictMono hlt, hr⟩
#align set.partially_well_ordered_on.union Set.PartiallyWellOrderedOn.union
@[simp]
theorem partiallyWellOrderedOn_union :
(s ∪ t).PartiallyWellOrderedOn r ↔ s.PartiallyWellOrderedOn r ∧ t.PartiallyWellOrderedOn r :=
⟨fun h => ⟨h.mono subset_union_left, h.mono subset_union_right⟩, fun h =>
h.1.union h.2⟩
#align set.partially_well_ordered_on_union Set.partiallyWellOrderedOn_union
theorem PartiallyWellOrderedOn.image_of_monotone_on (hs : s.PartiallyWellOrderedOn r)
(hf : ∀ a₁ ∈ s, ∀ a₂ ∈ s, r a₁ a₂ → r' (f a₁) (f a₂)) : (f '' s).PartiallyWellOrderedOn r' := by
intro g' hg'
choose g hgs heq using hg'
obtain rfl : f ∘ g = g' := funext heq
obtain ⟨m, n, hlt, hmn⟩ := hs g hgs
exact ⟨m, n, hlt, hf _ (hgs m) _ (hgs n) hmn⟩
#align set.partially_well_ordered_on.image_of_monotone_on Set.PartiallyWellOrderedOn.image_of_monotone_on
theorem _root_.IsAntichain.finite_of_partiallyWellOrderedOn (ha : IsAntichain r s)
(hp : s.PartiallyWellOrderedOn r) : s.Finite := by
refine not_infinite.1 fun hi => ?_
obtain ⟨m, n, hmn, h⟩ := hp (fun n => hi.natEmbedding _ n) fun n => (hi.natEmbedding _ n).2
exact hmn.ne ((hi.natEmbedding _).injective <| Subtype.val_injective <|
ha.eq (hi.natEmbedding _ m).2 (hi.natEmbedding _ n).2 h)
#align is_antichain.finite_of_partially_well_ordered_on IsAntichain.finite_of_partiallyWellOrderedOn
section IsRefl
variable [IsRefl α r]
protected theorem Finite.partiallyWellOrderedOn (hs : s.Finite) : s.PartiallyWellOrderedOn r := by
intro f hf
obtain ⟨m, n, hmn, h⟩ := hs.exists_lt_map_eq_of_forall_mem hf
exact ⟨m, n, hmn, h.subst <| refl (f m)⟩
#align set.finite.partially_well_ordered_on Set.Finite.partiallyWellOrderedOn
theorem _root_.IsAntichain.partiallyWellOrderedOn_iff (hs : IsAntichain r s) :
s.PartiallyWellOrderedOn r ↔ s.Finite :=
⟨hs.finite_of_partiallyWellOrderedOn, Finite.partiallyWellOrderedOn⟩
#align is_antichain.partially_well_ordered_on_iff IsAntichain.partiallyWellOrderedOn_iff
@[simp]
theorem partiallyWellOrderedOn_singleton (a : α) : PartiallyWellOrderedOn {a} r :=
(finite_singleton a).partiallyWellOrderedOn
#align set.partially_well_ordered_on_singleton Set.partiallyWellOrderedOn_singleton
@[nontriviality]
theorem Subsingleton.partiallyWellOrderedOn (hs : s.Subsingleton) : PartiallyWellOrderedOn s r :=
hs.finite.partiallyWellOrderedOn
@[simp]
theorem partiallyWellOrderedOn_insert :
PartiallyWellOrderedOn (insert a s) r ↔ PartiallyWellOrderedOn s r := by
simp only [← singleton_union, partiallyWellOrderedOn_union,
partiallyWellOrderedOn_singleton, true_and_iff]
#align set.partially_well_ordered_on_insert Set.partiallyWellOrderedOn_insert
protected theorem PartiallyWellOrderedOn.insert (h : PartiallyWellOrderedOn s r) (a : α) :
PartiallyWellOrderedOn (insert a s) r :=
partiallyWellOrderedOn_insert.2 h
#align set.partially_well_ordered_on.insert Set.PartiallyWellOrderedOn.insert
theorem partiallyWellOrderedOn_iff_finite_antichains [IsSymm α r] :
s.PartiallyWellOrderedOn r ↔ ∀ t, t ⊆ s → IsAntichain r t → t.Finite := by
refine ⟨fun h t ht hrt => hrt.finite_of_partiallyWellOrderedOn (h.mono ht), ?_⟩
rintro hs f hf
by_contra! H
refine infinite_range_of_injective (fun m n hmn => ?_) (hs _ (range_subset_iff.2 hf) ?_)
· obtain h | h | h := lt_trichotomy m n
· refine (H _ _ h ?_).elim
rw [hmn]
exact refl _
· exact h
· refine (H _ _ h ?_).elim
rw [hmn]
exact refl _
rintro _ ⟨m, hm, rfl⟩ _ ⟨n, hn, rfl⟩ hmn
obtain h | h := (ne_of_apply_ne _ hmn).lt_or_lt
· exact H _ _ h
· exact mt symm (H _ _ h)
#align set.partially_well_ordered_on_iff_finite_antichains Set.partiallyWellOrderedOn_iff_finite_antichains
variable [IsTrans α r]
theorem PartiallyWellOrderedOn.exists_monotone_subseq (h : s.PartiallyWellOrderedOn r) (f : ℕ → α)
(hf : ∀ n, f n ∈ s) : ∃ g : ℕ ↪o ℕ, ∀ m n : ℕ, m ≤ n → r (f (g m)) (f (g n)) := by
obtain ⟨g, h1 | h2⟩ := exists_increasing_or_nonincreasing_subseq r f
· refine ⟨g, fun m n hle => ?_⟩
obtain hlt | rfl := hle.lt_or_eq
exacts [h1 m n hlt, refl_of r _]
· exfalso
obtain ⟨m, n, hlt, hle⟩ := h (f ∘ g) fun n => hf _
exact h2 m n hlt hle
#align set.partially_well_ordered_on.exists_monotone_subseq Set.PartiallyWellOrderedOn.exists_monotone_subseq
| Mathlib/Order/WellFoundedSet.lean | 389 | 395 | theorem partiallyWellOrderedOn_iff_exists_monotone_subseq :
s.PartiallyWellOrderedOn r ↔
∀ f : ℕ → α, (∀ n, f n ∈ s) → ∃ g : ℕ ↪o ℕ, ∀ m n : ℕ, m ≤ n → r (f (g m)) (f (g n)) := by |
constructor <;> intro h f hf
· exact h.exists_monotone_subseq f hf
· obtain ⟨g, gmon⟩ := h f hf
exact ⟨g 0, g 1, g.lt_iff_lt.2 zero_lt_one, gmon _ _ zero_le_one⟩
|
import Mathlib.Algebra.Group.Nat
import Mathlib.Algebra.Order.Sub.Canonical
import Mathlib.Data.List.Perm
import Mathlib.Data.Set.List
import Mathlib.Init.Quot
import Mathlib.Order.Hom.Basic
#align_import data.multiset.basic from "leanprover-community/mathlib"@"65a1391a0106c9204fe45bc73a039f056558cb83"
universe v
open List Subtype Nat Function
variable {α : Type*} {β : Type v} {γ : Type*}
def Multiset.{u} (α : Type u) : Type u :=
Quotient (List.isSetoid α)
#align multiset Multiset
namespace Multiset
-- Porting note: new
@[coe]
def ofList : List α → Multiset α :=
Quot.mk _
instance : Coe (List α) (Multiset α) :=
⟨ofList⟩
@[simp]
theorem quot_mk_to_coe (l : List α) : @Eq (Multiset α) ⟦l⟧ l :=
rfl
#align multiset.quot_mk_to_coe Multiset.quot_mk_to_coe
@[simp]
theorem quot_mk_to_coe' (l : List α) : @Eq (Multiset α) (Quot.mk (· ≈ ·) l) l :=
rfl
#align multiset.quot_mk_to_coe' Multiset.quot_mk_to_coe'
@[simp]
theorem quot_mk_to_coe'' (l : List α) : @Eq (Multiset α) (Quot.mk Setoid.r l) l :=
rfl
#align multiset.quot_mk_to_coe'' Multiset.quot_mk_to_coe''
@[simp]
theorem coe_eq_coe {l₁ l₂ : List α} : (l₁ : Multiset α) = l₂ ↔ l₁ ~ l₂ :=
Quotient.eq
#align multiset.coe_eq_coe Multiset.coe_eq_coe
-- Porting note: new instance;
-- Porting note (#11215): TODO: move to better place
instance [DecidableEq α] (l₁ l₂ : List α) : Decidable (l₁ ≈ l₂) :=
inferInstanceAs (Decidable (l₁ ~ l₂))
-- Porting note: `Quotient.recOnSubsingleton₂ s₁ s₂` was in parens which broke elaboration
instance decidableEq [DecidableEq α] : DecidableEq (Multiset α)
| s₁, s₂ => Quotient.recOnSubsingleton₂ s₁ s₂ fun _ _ => decidable_of_iff' _ Quotient.eq
#align multiset.has_decidable_eq Multiset.decidableEq
protected
def sizeOf [SizeOf α] (s : Multiset α) : ℕ :=
(Quot.liftOn s SizeOf.sizeOf) fun _ _ => Perm.sizeOf_eq_sizeOf
#align multiset.sizeof Multiset.sizeOf
instance [SizeOf α] : SizeOf (Multiset α) :=
⟨Multiset.sizeOf⟩
protected def zero : Multiset α :=
@nil α
#align multiset.zero Multiset.zero
instance : Zero (Multiset α) :=
⟨Multiset.zero⟩
instance : EmptyCollection (Multiset α) :=
⟨0⟩
instance inhabitedMultiset : Inhabited (Multiset α) :=
⟨0⟩
#align multiset.inhabited_multiset Multiset.inhabitedMultiset
instance [IsEmpty α] : Unique (Multiset α) where
default := 0
uniq := by rintro ⟨_ | ⟨a, l⟩⟩; exacts [rfl, isEmptyElim a]
@[simp]
theorem coe_nil : (@nil α : Multiset α) = 0 :=
rfl
#align multiset.coe_nil Multiset.coe_nil
@[simp]
theorem empty_eq_zero : (∅ : Multiset α) = 0 :=
rfl
#align multiset.empty_eq_zero Multiset.empty_eq_zero
@[simp]
theorem coe_eq_zero (l : List α) : (l : Multiset α) = 0 ↔ l = [] :=
Iff.trans coe_eq_coe perm_nil
#align multiset.coe_eq_zero Multiset.coe_eq_zero
theorem coe_eq_zero_iff_isEmpty (l : List α) : (l : Multiset α) = 0 ↔ l.isEmpty :=
Iff.trans (coe_eq_zero l) isEmpty_iff_eq_nil.symm
#align multiset.coe_eq_zero_iff_empty Multiset.coe_eq_zero_iff_isEmpty
def cons (a : α) (s : Multiset α) : Multiset α :=
Quot.liftOn s (fun l => (a :: l : Multiset α)) fun _ _ p => Quot.sound (p.cons a)
#align multiset.cons Multiset.cons
@[inherit_doc Multiset.cons]
infixr:67 " ::ₘ " => Multiset.cons
instance : Insert α (Multiset α) :=
⟨cons⟩
@[simp]
theorem insert_eq_cons (a : α) (s : Multiset α) : insert a s = a ::ₘ s :=
rfl
#align multiset.insert_eq_cons Multiset.insert_eq_cons
@[simp]
theorem cons_coe (a : α) (l : List α) : (a ::ₘ l : Multiset α) = (a :: l : List α) :=
rfl
#align multiset.cons_coe Multiset.cons_coe
@[simp]
theorem cons_inj_left {a b : α} (s : Multiset α) : a ::ₘ s = b ::ₘ s ↔ a = b :=
⟨Quot.inductionOn s fun l e =>
have : [a] ++ l ~ [b] ++ l := Quotient.exact e
singleton_perm_singleton.1 <| (perm_append_right_iff _).1 this,
congr_arg (· ::ₘ _)⟩
#align multiset.cons_inj_left Multiset.cons_inj_left
@[simp]
theorem cons_inj_right (a : α) : ∀ {s t : Multiset α}, a ::ₘ s = a ::ₘ t ↔ s = t := by
rintro ⟨l₁⟩ ⟨l₂⟩; simp
#align multiset.cons_inj_right Multiset.cons_inj_right
@[elab_as_elim]
protected theorem induction {p : Multiset α → Prop} (empty : p 0)
(cons : ∀ (a : α) (s : Multiset α), p s → p (a ::ₘ s)) : ∀ s, p s := by
rintro ⟨l⟩; induction' l with _ _ ih <;> [exact empty; exact cons _ _ ih]
#align multiset.induction Multiset.induction
@[elab_as_elim]
protected theorem induction_on {p : Multiset α → Prop} (s : Multiset α) (empty : p 0)
(cons : ∀ (a : α) (s : Multiset α), p s → p (a ::ₘ s)) : p s :=
Multiset.induction empty cons s
#align multiset.induction_on Multiset.induction_on
theorem cons_swap (a b : α) (s : Multiset α) : a ::ₘ b ::ₘ s = b ::ₘ a ::ₘ s :=
Quot.inductionOn s fun _ => Quotient.sound <| Perm.swap _ _ _
#align multiset.cons_swap Multiset.cons_swap
section Mem
def Mem (a : α) (s : Multiset α) : Prop :=
Quot.liftOn s (fun l => a ∈ l) fun l₁ l₂ (e : l₁ ~ l₂) => propext <| e.mem_iff
#align multiset.mem Multiset.Mem
instance : Membership α (Multiset α) :=
⟨Mem⟩
@[simp]
theorem mem_coe {a : α} {l : List α} : a ∈ (l : Multiset α) ↔ a ∈ l :=
Iff.rfl
#align multiset.mem_coe Multiset.mem_coe
instance decidableMem [DecidableEq α] (a : α) (s : Multiset α) : Decidable (a ∈ s) :=
Quot.recOnSubsingleton' s fun l ↦ inferInstanceAs (Decidable (a ∈ l))
#align multiset.decidable_mem Multiset.decidableMem
@[simp]
theorem mem_cons {a b : α} {s : Multiset α} : a ∈ b ::ₘ s ↔ a = b ∨ a ∈ s :=
Quot.inductionOn s fun _ => List.mem_cons
#align multiset.mem_cons Multiset.mem_cons
theorem mem_cons_of_mem {a b : α} {s : Multiset α} (h : a ∈ s) : a ∈ b ::ₘ s :=
mem_cons.2 <| Or.inr h
#align multiset.mem_cons_of_mem Multiset.mem_cons_of_mem
-- @[simp] -- Porting note (#10618): simp can prove this
theorem mem_cons_self (a : α) (s : Multiset α) : a ∈ a ::ₘ s :=
mem_cons.2 (Or.inl rfl)
#align multiset.mem_cons_self Multiset.mem_cons_self
theorem forall_mem_cons {p : α → Prop} {a : α} {s : Multiset α} :
(∀ x ∈ a ::ₘ s, p x) ↔ p a ∧ ∀ x ∈ s, p x :=
Quotient.inductionOn' s fun _ => List.forall_mem_cons
#align multiset.forall_mem_cons Multiset.forall_mem_cons
theorem exists_cons_of_mem {s : Multiset α} {a : α} : a ∈ s → ∃ t, s = a ::ₘ t :=
Quot.inductionOn s fun l (h : a ∈ l) =>
let ⟨l₁, l₂, e⟩ := append_of_mem h
e.symm ▸ ⟨(l₁ ++ l₂ : List α), Quot.sound perm_middle⟩
#align multiset.exists_cons_of_mem Multiset.exists_cons_of_mem
@[simp]
theorem not_mem_zero (a : α) : a ∉ (0 : Multiset α) :=
List.not_mem_nil _
#align multiset.not_mem_zero Multiset.not_mem_zero
theorem eq_zero_of_forall_not_mem {s : Multiset α} : (∀ x, x ∉ s) → s = 0 :=
Quot.inductionOn s fun l H => by rw [eq_nil_iff_forall_not_mem.mpr H]; rfl
#align multiset.eq_zero_of_forall_not_mem Multiset.eq_zero_of_forall_not_mem
theorem eq_zero_iff_forall_not_mem {s : Multiset α} : s = 0 ↔ ∀ a, a ∉ s :=
⟨fun h => h.symm ▸ fun _ => not_mem_zero _, eq_zero_of_forall_not_mem⟩
#align multiset.eq_zero_iff_forall_not_mem Multiset.eq_zero_iff_forall_not_mem
theorem exists_mem_of_ne_zero {s : Multiset α} : s ≠ 0 → ∃ a : α, a ∈ s :=
Quot.inductionOn s fun l hl =>
match l, hl with
| [], h => False.elim <| h rfl
| a :: l, _ => ⟨a, by simp⟩
#align multiset.exists_mem_of_ne_zero Multiset.exists_mem_of_ne_zero
theorem empty_or_exists_mem (s : Multiset α) : s = 0 ∨ ∃ a, a ∈ s :=
or_iff_not_imp_left.mpr Multiset.exists_mem_of_ne_zero
#align multiset.empty_or_exists_mem Multiset.empty_or_exists_mem
@[simp]
theorem zero_ne_cons {a : α} {m : Multiset α} : 0 ≠ a ::ₘ m := fun h =>
have : a ∈ (0 : Multiset α) := h.symm ▸ mem_cons_self _ _
not_mem_zero _ this
#align multiset.zero_ne_cons Multiset.zero_ne_cons
@[simp]
theorem cons_ne_zero {a : α} {m : Multiset α} : a ::ₘ m ≠ 0 :=
zero_ne_cons.symm
#align multiset.cons_ne_zero Multiset.cons_ne_zero
| Mathlib/Data/Multiset/Basic.lean | 302 | 321 | theorem cons_eq_cons {a b : α} {as bs : Multiset α} :
a ::ₘ as = b ::ₘ bs ↔ a = b ∧ as = bs ∨ a ≠ b ∧ ∃ cs, as = b ::ₘ cs ∧ bs = a ::ₘ cs := by |
haveI : DecidableEq α := Classical.decEq α
constructor
· intro eq
by_cases h : a = b
· subst h
simp_all
· have : a ∈ b ::ₘ bs := eq ▸ mem_cons_self _ _
have : a ∈ bs := by simpa [h]
rcases exists_cons_of_mem this with ⟨cs, hcs⟩
simp only [h, hcs, false_and, ne_eq, not_false_eq_true, cons_inj_right, exists_eq_right',
true_and, false_or]
have : a ::ₘ as = b ::ₘ a ::ₘ cs := by simp [eq, hcs]
have : a ::ₘ as = a ::ₘ b ::ₘ cs := by rwa [cons_swap]
simpa using this
· intro h
rcases h with (⟨eq₁, eq₂⟩ | ⟨_, cs, eq₁, eq₂⟩)
· simp [*]
· simp [*, cons_swap a b]
|
import Mathlib.Algebra.BigOperators.Intervals
import Mathlib.Algebra.BigOperators.Ring.List
import Mathlib.Data.Int.ModEq
import Mathlib.Data.Nat.Bits
import Mathlib.Data.Nat.Log
import Mathlib.Data.List.Indexes
import Mathlib.Data.List.Palindrome
import Mathlib.Tactic.IntervalCases
import Mathlib.Tactic.Linarith
import Mathlib.Tactic.Ring
#align_import data.nat.digits from "leanprover-community/mathlib"@"369525b73f229ccd76a6ec0e0e0bf2be57599768"
namespace Nat
variable {n : ℕ}
def digitsAux0 : ℕ → List ℕ
| 0 => []
| n + 1 => [n + 1]
#align nat.digits_aux_0 Nat.digitsAux0
def digitsAux1 (n : ℕ) : List ℕ :=
List.replicate n 1
#align nat.digits_aux_1 Nat.digitsAux1
def digitsAux (b : ℕ) (h : 2 ≤ b) : ℕ → List ℕ
| 0 => []
| n + 1 =>
((n + 1) % b) :: digitsAux b h ((n + 1) / b)
decreasing_by exact Nat.div_lt_self (Nat.succ_pos _) h
#align nat.digits_aux Nat.digitsAux
@[simp]
theorem digitsAux_zero (b : ℕ) (h : 2 ≤ b) : digitsAux b h 0 = [] := by rw [digitsAux]
#align nat.digits_aux_zero Nat.digitsAux_zero
theorem digitsAux_def (b : ℕ) (h : 2 ≤ b) (n : ℕ) (w : 0 < n) :
digitsAux b h n = (n % b) :: digitsAux b h (n / b) := by
cases n
· cases w
· rw [digitsAux]
#align nat.digits_aux_def Nat.digitsAux_def
def digits : ℕ → ℕ → List ℕ
| 0 => digitsAux0
| 1 => digitsAux1
| b + 2 => digitsAux (b + 2) (by norm_num)
#align nat.digits Nat.digits
@[simp]
theorem digits_zero (b : ℕ) : digits b 0 = [] := by
rcases b with (_ | ⟨_ | ⟨_⟩⟩) <;> simp [digits, digitsAux0, digitsAux1]
#align nat.digits_zero Nat.digits_zero
-- @[simp] -- Porting note (#10618): simp can prove this
theorem digits_zero_zero : digits 0 0 = [] :=
rfl
#align nat.digits_zero_zero Nat.digits_zero_zero
@[simp]
theorem digits_zero_succ (n : ℕ) : digits 0 n.succ = [n + 1] :=
rfl
#align nat.digits_zero_succ Nat.digits_zero_succ
theorem digits_zero_succ' : ∀ {n : ℕ}, n ≠ 0 → digits 0 n = [n]
| 0, h => (h rfl).elim
| _ + 1, _ => rfl
#align nat.digits_zero_succ' Nat.digits_zero_succ'
@[simp]
theorem digits_one (n : ℕ) : digits 1 n = List.replicate n 1 :=
rfl
#align nat.digits_one Nat.digits_one
-- @[simp] -- Porting note (#10685): dsimp can prove this
theorem digits_one_succ (n : ℕ) : digits 1 (n + 1) = 1 :: digits 1 n :=
rfl
#align nat.digits_one_succ Nat.digits_one_succ
theorem digits_add_two_add_one (b n : ℕ) :
digits (b + 2) (n + 1) = ((n + 1) % (b + 2)) :: digits (b + 2) ((n + 1) / (b + 2)) := by
simp [digits, digitsAux_def]
#align nat.digits_add_two_add_one Nat.digits_add_two_add_one
@[simp]
lemma digits_of_two_le_of_pos {b : ℕ} (hb : 2 ≤ b) (hn : 0 < n) :
Nat.digits b n = n % b :: Nat.digits b (n / b) := by
rw [Nat.eq_add_of_sub_eq hb rfl, Nat.eq_add_of_sub_eq hn rfl, Nat.digits_add_two_add_one]
theorem digits_def' :
∀ {b : ℕ} (_ : 1 < b) {n : ℕ} (_ : 0 < n), digits b n = (n % b) :: digits b (n / b)
| 0, h => absurd h (by decide)
| 1, h => absurd h (by decide)
| b + 2, _ => digitsAux_def _ (by simp) _
#align nat.digits_def' Nat.digits_def'
@[simp]
theorem digits_of_lt (b x : ℕ) (hx : x ≠ 0) (hxb : x < b) : digits b x = [x] := by
rcases exists_eq_succ_of_ne_zero hx with ⟨x, rfl⟩
rcases Nat.exists_eq_add_of_le' ((Nat.le_add_left 1 x).trans_lt hxb) with ⟨b, rfl⟩
rw [digits_add_two_add_one, div_eq_of_lt hxb, digits_zero, mod_eq_of_lt hxb]
#align nat.digits_of_lt Nat.digits_of_lt
theorem digits_add (b : ℕ) (h : 1 < b) (x y : ℕ) (hxb : x < b) (hxy : x ≠ 0 ∨ y ≠ 0) :
digits b (x + b * y) = x :: digits b y := by
rcases Nat.exists_eq_add_of_le' h with ⟨b, rfl : _ = _ + 2⟩
cases y
· simp [hxb, hxy.resolve_right (absurd rfl)]
dsimp [digits]
rw [digitsAux_def]
· congr
· simp [Nat.add_mod, mod_eq_of_lt hxb]
· simp [add_mul_div_left, div_eq_of_lt hxb]
· apply Nat.succ_pos
#align nat.digits_add Nat.digits_add
-- If we had a function converting a list into a polynomial,
-- and appropriate lemmas about that function,
-- we could rewrite this in terms of that.
def ofDigits {α : Type*} [Semiring α] (b : α) : List ℕ → α
| [] => 0
| h :: t => h + b * ofDigits b t
#align nat.of_digits Nat.ofDigits
theorem ofDigits_eq_foldr {α : Type*} [Semiring α] (b : α) (L : List ℕ) :
ofDigits b L = List.foldr (fun x y => ↑x + b * y) 0 L := by
induction' L with d L ih
· rfl
· dsimp [ofDigits]
rw [ih]
#align nat.of_digits_eq_foldr Nat.ofDigits_eq_foldr
theorem ofDigits_eq_sum_map_with_index_aux (b : ℕ) (l : List ℕ) :
((List.range l.length).zipWith ((fun i a : ℕ => a * b ^ (i + 1))) l).sum =
b * ((List.range l.length).zipWith (fun i a => a * b ^ i) l).sum := by
suffices
(List.range l.length).zipWith (fun i a : ℕ => a * b ^ (i + 1)) l =
(List.range l.length).zipWith (fun i a => b * (a * b ^ i)) l
by simp [this]
congr; ext; simp [pow_succ]; ring
#align nat.of_digits_eq_sum_map_with_index_aux Nat.ofDigits_eq_sum_map_with_index_aux
theorem ofDigits_eq_sum_mapIdx (b : ℕ) (L : List ℕ) :
ofDigits b L = (L.mapIdx fun i a => a * b ^ i).sum := by
rw [List.mapIdx_eq_enum_map, List.enum_eq_zip_range, List.map_uncurry_zip_eq_zipWith,
ofDigits_eq_foldr]
induction' L with hd tl hl
· simp
· simpa [List.range_succ_eq_map, List.zipWith_map_left, ofDigits_eq_sum_map_with_index_aux] using
Or.inl hl
#align nat.of_digits_eq_sum_map_with_index Nat.ofDigits_eq_sum_mapIdx
@[simp]
theorem ofDigits_nil {b : ℕ} : ofDigits b [] = 0 := rfl
@[simp]
theorem ofDigits_singleton {b n : ℕ} : ofDigits b [n] = n := by simp [ofDigits]
#align nat.of_digits_singleton Nat.ofDigits_singleton
@[simp]
theorem ofDigits_one_cons {α : Type*} [Semiring α] (h : ℕ) (L : List ℕ) :
ofDigits (1 : α) (h :: L) = h + ofDigits 1 L := by simp [ofDigits]
#align nat.of_digits_one_cons Nat.ofDigits_one_cons
theorem ofDigits_cons {b hd} {tl : List ℕ} :
ofDigits b (hd :: tl) = hd + b * ofDigits b tl := rfl
theorem ofDigits_append {b : ℕ} {l1 l2 : List ℕ} :
ofDigits b (l1 ++ l2) = ofDigits b l1 + b ^ l1.length * ofDigits b l2 := by
induction' l1 with hd tl IH
· simp [ofDigits]
· rw [ofDigits, List.cons_append, ofDigits, IH, List.length_cons, pow_succ']
ring
#align nat.of_digits_append Nat.ofDigits_append
@[norm_cast]
theorem coe_ofDigits (α : Type*) [Semiring α] (b : ℕ) (L : List ℕ) :
((ofDigits b L : ℕ) : α) = ofDigits (b : α) L := by
induction' L with d L ih
· simp [ofDigits]
· dsimp [ofDigits]; push_cast; rw [ih]
#align nat.coe_of_digits Nat.coe_ofDigits
@[norm_cast]
theorem coe_int_ofDigits (b : ℕ) (L : List ℕ) : ((ofDigits b L : ℕ) : ℤ) = ofDigits (b : ℤ) L := by
induction' L with d L _
· rfl
· dsimp [ofDigits]; push_cast; simp only
#align nat.coe_int_of_digits Nat.coe_int_ofDigits
theorem digits_zero_of_eq_zero {b : ℕ} (h : b ≠ 0) :
∀ {L : List ℕ} (_ : ofDigits b L = 0), ∀ l ∈ L, l = 0
| _ :: _, h0, _, List.Mem.head .. => Nat.eq_zero_of_add_eq_zero_right h0
| _ :: _, h0, _, List.Mem.tail _ hL =>
digits_zero_of_eq_zero h (mul_right_injective₀ h (Nat.eq_zero_of_add_eq_zero_left h0)) _ hL
#align nat.digits_zero_of_eq_zero Nat.digits_zero_of_eq_zero
theorem digits_ofDigits (b : ℕ) (h : 1 < b) (L : List ℕ) (w₁ : ∀ l ∈ L, l < b)
(w₂ : ∀ h : L ≠ [], L.getLast h ≠ 0) : digits b (ofDigits b L) = L := by
induction' L with d L ih
· dsimp [ofDigits]
simp
· dsimp [ofDigits]
replace w₂ := w₂ (by simp)
rw [digits_add b h]
· rw [ih]
· intro l m
apply w₁
exact List.mem_cons_of_mem _ m
· intro h
rw [List.getLast_cons h] at w₂
convert w₂
· exact w₁ d (List.mem_cons_self _ _)
· by_cases h' : L = []
· rcases h' with rfl
left
simpa using w₂
· right
contrapose! w₂
refine digits_zero_of_eq_zero h.ne_bot w₂ _ ?_
rw [List.getLast_cons h']
exact List.getLast_mem h'
#align nat.digits_of_digits Nat.digits_ofDigits
theorem ofDigits_digits (b n : ℕ) : ofDigits b (digits b n) = n := by
cases' b with b
· cases' n with n
· rfl
· change ofDigits 0 [n + 1] = n + 1
dsimp [ofDigits]
· cases' b with b
· induction' n with n ih
· rfl
· rw [Nat.zero_add] at ih ⊢
simp only [ih, add_comm 1, ofDigits_one_cons, Nat.cast_id, digits_one_succ]
· apply Nat.strongInductionOn n _
clear n
intro n h
cases n
· rw [digits_zero]
rfl
· simp only [Nat.succ_eq_add_one, digits_add_two_add_one]
dsimp [ofDigits]
rw [h _ (Nat.div_lt_self' _ b)]
rw [Nat.mod_add_div]
#align nat.of_digits_digits Nat.ofDigits_digits
theorem ofDigits_one (L : List ℕ) : ofDigits 1 L = L.sum := by
induction' L with _ _ ih
· rfl
· simp [ofDigits, List.sum_cons, ih]
#align nat.of_digits_one Nat.ofDigits_one
theorem digits_eq_nil_iff_eq_zero {b n : ℕ} : digits b n = [] ↔ n = 0 := by
constructor
· intro h
have : ofDigits b (digits b n) = ofDigits b [] := by rw [h]
convert this
rw [ofDigits_digits]
· rintro rfl
simp
#align nat.digits_eq_nil_iff_eq_zero Nat.digits_eq_nil_iff_eq_zero
theorem digits_ne_nil_iff_ne_zero {b n : ℕ} : digits b n ≠ [] ↔ n ≠ 0 :=
not_congr digits_eq_nil_iff_eq_zero
#align nat.digits_ne_nil_iff_ne_zero Nat.digits_ne_nil_iff_ne_zero
theorem digits_eq_cons_digits_div {b n : ℕ} (h : 1 < b) (w : n ≠ 0) :
digits b n = (n % b) :: digits b (n / b) := by
rcases b with (_ | _ | b)
· rw [digits_zero_succ' w, Nat.mod_zero, Nat.div_zero, Nat.digits_zero_zero]
· norm_num at h
rcases n with (_ | n)
· norm_num at w
· simp only [digits_add_two_add_one, ne_eq]
#align nat.digits_eq_cons_digits_div Nat.digits_eq_cons_digits_div
theorem digits_getLast {b : ℕ} (m : ℕ) (h : 1 < b) (p q) :
(digits b m).getLast p = (digits b (m / b)).getLast q := by
by_cases hm : m = 0
· simp [hm]
simp only [digits_eq_cons_digits_div h hm]
rw [List.getLast_cons]
#align nat.digits_last Nat.digits_getLast
theorem digits.injective (b : ℕ) : Function.Injective b.digits :=
Function.LeftInverse.injective (ofDigits_digits b)
#align nat.digits.injective Nat.digits.injective
@[simp]
theorem digits_inj_iff {b n m : ℕ} : b.digits n = b.digits m ↔ n = m :=
(digits.injective b).eq_iff
#align nat.digits_inj_iff Nat.digits_inj_iff
theorem digits_len (b n : ℕ) (hb : 1 < b) (hn : n ≠ 0) : (b.digits n).length = b.log n + 1 := by
induction' n using Nat.strong_induction_on with n IH
rw [digits_eq_cons_digits_div hb hn, List.length]
by_cases h : n / b = 0
· have hb0 : b ≠ 0 := (Nat.succ_le_iff.1 hb).ne_bot
simp [h, log_eq_zero_iff, ← Nat.div_eq_zero_iff hb0.bot_lt]
· have : n / b < n := div_lt_self (Nat.pos_of_ne_zero hn) hb
rw [IH _ this h, log_div_base, tsub_add_cancel_of_le]
refine Nat.succ_le_of_lt (log_pos hb ?_)
contrapose! h
exact div_eq_of_lt h
#align nat.digits_len Nat.digits_len
theorem getLast_digit_ne_zero (b : ℕ) {m : ℕ} (hm : m ≠ 0) :
(digits b m).getLast (digits_ne_nil_iff_ne_zero.mpr hm) ≠ 0 := by
rcases b with (_ | _ | b)
· cases m
· cases hm rfl
· simp
· cases m
· cases hm rfl
rename ℕ => m
simp only [zero_add, digits_one, List.getLast_replicate_succ m 1]
exact Nat.one_ne_zero
revert hm
apply Nat.strongInductionOn m
intro n IH hn
by_cases hnb : n < b + 2
· simpa only [digits_of_lt (b + 2) n hn hnb]
· rw [digits_getLast n (le_add_left 2 b)]
refine IH _ (Nat.div_lt_self hn.bot_lt (one_lt_succ_succ b)) ?_
rw [← pos_iff_ne_zero]
exact Nat.div_pos (le_of_not_lt hnb) (zero_lt_succ (succ b))
#align nat.last_digit_ne_zero Nat.getLast_digit_ne_zero
theorem mul_ofDigits (n : ℕ) {b : ℕ} {l : List ℕ} :
n * ofDigits b l = ofDigits b (l.map (n * ·)) := by
induction l with
| nil => rfl
| cons hd tl ih =>
rw [List.map_cons, ofDigits_cons, ofDigits_cons, ← ih]
ring
theorem ofDigits_add_ofDigits_eq_ofDigits_zipWith_of_length_eq {b : ℕ} {l1 l2 : List ℕ}
(h : l1.length = l2.length) :
ofDigits b l1 + ofDigits b l2 = ofDigits b (l1.zipWith (· + ·) l2) := by
induction l1 generalizing l2 with
| nil => simp_all [eq_comm, List.length_eq_zero, ofDigits]
| cons hd₁ tl₁ ih₁ =>
induction l2 generalizing tl₁ with
| nil => simp_all
| cons hd₂ tl₂ ih₂ =>
simp_all only [List.length_cons, succ_eq_add_one, ofDigits_cons, add_left_inj,
eq_comm, List.zipWith_cons_cons, add_eq]
rw [← ih₁ h.symm, mul_add]
ac_rfl
theorem digits_lt_base' {b m : ℕ} : ∀ {d}, d ∈ digits (b + 2) m → d < b + 2 := by
apply Nat.strongInductionOn m
intro n IH d hd
cases' n with n
· rw [digits_zero] at hd
cases hd
-- base b+2 expansion of 0 has no digits
rw [digits_add_two_add_one] at hd
cases hd
· exact n.succ.mod_lt (by simp)
-- Porting note: Previous code (single line) contained linarith.
-- . exact IH _ (Nat.div_lt_self (Nat.succ_pos _) (by linarith)) hd
· apply IH ((n + 1) / (b + 2))
· apply Nat.div_lt_self <;> omega
· assumption
#align nat.digits_lt_base' Nat.digits_lt_base'
theorem digits_lt_base {b m d : ℕ} (hb : 1 < b) (hd : d ∈ digits b m) : d < b := by
rcases b with (_ | _ | b) <;> try simp_all
exact digits_lt_base' hd
#align nat.digits_lt_base Nat.digits_lt_base
theorem ofDigits_lt_base_pow_length' {b : ℕ} {l : List ℕ} (hl : ∀ x ∈ l, x < b + 2) :
ofDigits (b + 2) l < (b + 2) ^ l.length := by
induction' l with hd tl IH
· simp [ofDigits]
· rw [ofDigits, List.length_cons, pow_succ]
have : (ofDigits (b + 2) tl + 1) * (b + 2) ≤ (b + 2) ^ tl.length * (b + 2) :=
mul_le_mul (IH fun x hx => hl _ (List.mem_cons_of_mem _ hx)) (by rfl) (by simp only [zero_le])
(Nat.zero_le _)
suffices ↑hd < b + 2 by linarith
exact hl hd (List.mem_cons_self _ _)
#align nat.of_digits_lt_base_pow_length' Nat.ofDigits_lt_base_pow_length'
theorem ofDigits_lt_base_pow_length {b : ℕ} {l : List ℕ} (hb : 1 < b) (hl : ∀ x ∈ l, x < b) :
ofDigits b l < b ^ l.length := by
rcases b with (_ | _ | b) <;> try simp_all
exact ofDigits_lt_base_pow_length' hl
#align nat.of_digits_lt_base_pow_length Nat.ofDigits_lt_base_pow_length
theorem lt_base_pow_length_digits' {b m : ℕ} : m < (b + 2) ^ (digits (b + 2) m).length := by
convert @ofDigits_lt_base_pow_length' b (digits (b + 2) m) fun _ => digits_lt_base'
rw [ofDigits_digits (b + 2) m]
#align nat.lt_base_pow_length_digits' Nat.lt_base_pow_length_digits'
theorem lt_base_pow_length_digits {b m : ℕ} (hb : 1 < b) : m < b ^ (digits b m).length := by
rcases b with (_ | _ | b) <;> try simp_all
exact lt_base_pow_length_digits'
#align nat.lt_base_pow_length_digits Nat.lt_base_pow_length_digits
theorem ofDigits_digits_append_digits {b m n : ℕ} :
ofDigits b (digits b n ++ digits b m) = n + b ^ (digits b n).length * m := by
rw [ofDigits_append, ofDigits_digits, ofDigits_digits]
#align nat.of_digits_digits_append_digits Nat.ofDigits_digits_append_digits
theorem digits_append_digits {b m n : ℕ} (hb : 0 < b) :
digits b n ++ digits b m = digits b (n + b ^ (digits b n).length * m) := by
rcases eq_or_lt_of_le (Nat.succ_le_of_lt hb) with (rfl | hb)
· simp [List.replicate_add]
rw [← ofDigits_digits_append_digits]
refine (digits_ofDigits b hb _ (fun l hl => ?_) (fun h_append => ?_)).symm
· rcases (List.mem_append.mp hl) with (h | h) <;> exact digits_lt_base hb h
· by_cases h : digits b m = []
· simp only [h, List.append_nil] at h_append ⊢
exact getLast_digit_ne_zero b <| digits_ne_nil_iff_ne_zero.mp h_append
· exact (List.getLast_append' _ _ h) ▸
(getLast_digit_ne_zero _ <| digits_ne_nil_iff_ne_zero.mp h)
theorem digits_len_le_digits_len_succ (b n : ℕ) :
(digits b n).length ≤ (digits b (n + 1)).length := by
rcases Decidable.eq_or_ne n 0 with (rfl | hn)
· simp
rcases le_or_lt b 1 with hb | hb
· interval_cases b <;> simp_arith [digits_zero_succ', hn]
simpa [digits_len, hb, hn] using log_mono_right (le_succ _)
#align nat.digits_len_le_digits_len_succ Nat.digits_len_le_digits_len_succ
theorem le_digits_len_le (b n m : ℕ) (h : n ≤ m) : (digits b n).length ≤ (digits b m).length :=
monotone_nat_of_le_succ (digits_len_le_digits_len_succ b) h
#align nat.le_digits_len_le Nat.le_digits_len_le
@[mono]
theorem ofDigits_monotone {p q : ℕ} (L : List ℕ) (h : p ≤ q) : ofDigits p L ≤ ofDigits q L := by
induction' L with _ _ hi
· rfl
· simp only [ofDigits, cast_id, add_le_add_iff_left]
exact Nat.mul_le_mul h hi
theorem sum_le_ofDigits {p : ℕ} (L : List ℕ) (h : 1 ≤ p) : L.sum ≤ ofDigits p L :=
(ofDigits_one L).symm ▸ ofDigits_monotone L h
theorem digit_sum_le (p n : ℕ) : List.sum (digits p n) ≤ n := by
induction' n with n
· exact digits_zero _ ▸ Nat.le_refl (List.sum [])
· induction' p with p
· rw [digits_zero_succ, List.sum_cons, List.sum_nil, add_zero]
· nth_rw 2 [← ofDigits_digits p.succ (n + 1)]
rw [← ofDigits_one <| digits p.succ n.succ]
exact ofDigits_monotone (digits p.succ n.succ) <| Nat.succ_pos p
theorem pow_length_le_mul_ofDigits {b : ℕ} {l : List ℕ} (hl : l ≠ []) (hl2 : l.getLast hl ≠ 0) :
(b + 2) ^ l.length ≤ (b + 2) * ofDigits (b + 2) l := by
rw [← List.dropLast_append_getLast hl]
simp only [List.length_append, List.length, zero_add, List.length_dropLast, ofDigits_append,
List.length_dropLast, ofDigits_singleton, add_comm (l.length - 1), pow_add, pow_one]
apply Nat.mul_le_mul_left
refine le_trans ?_ (Nat.le_add_left _ _)
have : 0 < l.getLast hl := by rwa [pos_iff_ne_zero]
convert Nat.mul_le_mul_left ((b + 2) ^ (l.length - 1)) this using 1
rw [Nat.mul_one]
#align nat.pow_length_le_mul_of_digits Nat.pow_length_le_mul_ofDigits
theorem base_pow_length_digits_le' (b m : ℕ) (hm : m ≠ 0) :
(b + 2) ^ (digits (b + 2) m).length ≤ (b + 2) * m := by
have : digits (b + 2) m ≠ [] := digits_ne_nil_iff_ne_zero.mpr hm
convert @pow_length_le_mul_ofDigits b (digits (b+2) m)
this (getLast_digit_ne_zero _ hm)
rw [ofDigits_digits]
#align nat.base_pow_length_digits_le' Nat.base_pow_length_digits_le'
theorem base_pow_length_digits_le (b m : ℕ) (hb : 1 < b) :
m ≠ 0 → b ^ (digits b m).length ≤ b * m := by
rcases b with (_ | _ | b) <;> try simp_all
exact base_pow_length_digits_le' b m
#align nat.base_pow_length_digits_le Nat.base_pow_length_digits_le
lemma ofDigits_div_eq_ofDigits_tail {p : ℕ} (hpos : 0 < p) (digits : List ℕ)
(w₁ : ∀ l ∈ digits, l < p) : ofDigits p digits / p = ofDigits p digits.tail := by
induction' digits with hd tl
· simp [ofDigits]
· refine Eq.trans (add_mul_div_left hd _ hpos) ?_
rw [Nat.div_eq_of_lt <| w₁ _ <| List.mem_cons_self _ _, zero_add]
rfl
lemma ofDigits_div_pow_eq_ofDigits_drop
{p : ℕ} (i : ℕ) (hpos : 0 < p) (digits : List ℕ) (w₁ : ∀ l ∈ digits, l < p) :
ofDigits p digits / p ^ i = ofDigits p (digits.drop i) := by
induction' i with i hi
· simp
· rw [Nat.pow_succ, ← Nat.div_div_eq_div_mul, hi, ofDigits_div_eq_ofDigits_tail hpos
(List.drop i digits) fun x hx ↦ w₁ x <| List.mem_of_mem_drop hx, ← List.drop_one,
List.drop_drop, add_comm]
lemma self_div_pow_eq_ofDigits_drop {p : ℕ} (i n : ℕ) (h : 2 ≤ p):
n / p ^ i = ofDigits p ((p.digits n).drop i) := by
convert ofDigits_div_pow_eq_ofDigits_drop i (zero_lt_of_lt h) (p.digits n)
(fun l hl ↦ digits_lt_base h hl)
exact (ofDigits_digits p n).symm
open Finset
theorem sub_one_mul_sum_div_pow_eq_sub_sum_digits {p : ℕ}
(L : List ℕ) {h_nonempty} (h_ne_zero : L.getLast h_nonempty ≠ 0) (h_lt : ∀ l ∈ L, l < p) :
(p - 1) * ∑ i ∈ range L.length, (ofDigits p L) / p ^ i.succ = (ofDigits p L) - L.sum := by
obtain h | rfl | h : 1 < p ∨ 1 = p ∨ p < 1 := trichotomous 1 p
· induction' L with hd tl ih
· simp [ofDigits]
· simp only [List.length_cons, List.sum_cons, self_div_pow_eq_ofDigits_drop _ _ h,
digits_ofDigits p h (hd :: tl) h_lt (fun _ => h_ne_zero)]
simp only [ofDigits]
rw [sum_range_succ, Nat.cast_id]
simp only [List.drop, List.drop_length]
obtain rfl | h' := em <| tl = []
· simp [ofDigits]
· have w₁' := fun l hl ↦ h_lt l <| List.mem_cons_of_mem hd hl
have w₂' := fun (h : tl ≠ []) ↦ (List.getLast_cons h) ▸ h_ne_zero
have ih := ih (w₂' h') w₁'
simp only [self_div_pow_eq_ofDigits_drop _ _ h, digits_ofDigits p h tl w₁' w₂',
← Nat.one_add] at ih
have := sum_singleton (fun x ↦ ofDigits p <| tl.drop x) tl.length
rw [← Ico_succ_singleton, List.drop_length, ofDigits] at this
have h₁ : 1 ≤ tl.length := List.length_pos.mpr h'
rw [← sum_range_add_sum_Ico _ <| h₁, ← add_zero (∑ x ∈ Ico _ _, ofDigits p (tl.drop x)),
← this, sum_Ico_consecutive _ h₁ <| (le_add_right tl.length 1),
← sum_Ico_add _ 0 tl.length 1,
Ico_zero_eq_range, mul_add, mul_add, ih, range_one, sum_singleton, List.drop, ofDigits,
mul_zero, add_zero, ← Nat.add_sub_assoc <| sum_le_ofDigits _ <| Nat.le_of_lt h]
nth_rw 2 [← one_mul <| ofDigits p tl]
rw [← add_mul, one_eq_succ_zero, Nat.sub_add_cancel <| zero_lt_of_lt h,
Nat.add_sub_add_left]
· simp [ofDigits_one]
· simp [lt_one_iff.mp h]
cases L
· rfl
· simp [ofDigits]
theorem sub_one_mul_sum_log_div_pow_eq_sub_sum_digits {p : ℕ} (n : ℕ) :
(p - 1) * ∑ i ∈ range (log p n).succ, n / p ^ i.succ = n - (p.digits n).sum := by
obtain h | rfl | h : 1 < p ∨ 1 = p ∨ p < 1 := trichotomous 1 p
· rcases eq_or_ne n 0 with rfl | hn
· simp
· convert sub_one_mul_sum_div_pow_eq_sub_sum_digits (p.digits n) (getLast_digit_ne_zero p hn) <|
(fun l a ↦ digits_lt_base h a)
· refine (digits_len p n h hn).symm
all_goals exact (ofDigits_digits p n).symm
· simp
· simp [lt_one_iff.mp h]
cases n
all_goals simp
theorem digits_two_eq_bits (n : ℕ) : digits 2 n = n.bits.map fun b => cond b 1 0 := by
induction' n using Nat.binaryRecFromOne with b n h ih
· simp
· rfl
rw [bits_append_bit _ _ fun hn => absurd hn h]
cases b
· rw [digits_def' one_lt_two]
· simpa [Nat.bit, Nat.bit0_val n]
· simpa [pos_iff_ne_zero, Nat.bit0_eq_zero]
· simpa [Nat.bit, Nat.bit1_val n, add_comm, digits_add 2 one_lt_two 1 n, Nat.add_mul_div_left]
#align nat.digits_two_eq_bits Nat.digits_two_eq_bits
-- This is really a theorem about polynomials.
theorem dvd_ofDigits_sub_ofDigits {α : Type*} [CommRing α] {a b k : α} (h : k ∣ a - b)
(L : List ℕ) : k ∣ ofDigits a L - ofDigits b L := by
induction' L with d L ih
· change k ∣ 0 - 0
simp
· simp only [ofDigits, add_sub_add_left_eq_sub]
exact dvd_mul_sub_mul h ih
#align nat.dvd_of_digits_sub_of_digits Nat.dvd_ofDigits_sub_ofDigits
theorem ofDigits_modEq' (b b' : ℕ) (k : ℕ) (h : b ≡ b' [MOD k]) (L : List ℕ) :
ofDigits b L ≡ ofDigits b' L [MOD k] := by
induction' L with d L ih
· rfl
· dsimp [ofDigits]
dsimp [Nat.ModEq] at *
conv_lhs => rw [Nat.add_mod, Nat.mul_mod, h, ih]
conv_rhs => rw [Nat.add_mod, Nat.mul_mod]
#align nat.of_digits_modeq' Nat.ofDigits_modEq'
theorem ofDigits_modEq (b k : ℕ) (L : List ℕ) : ofDigits b L ≡ ofDigits (b % k) L [MOD k] :=
ofDigits_modEq' b (b % k) k (b.mod_modEq k).symm L
#align nat.of_digits_modeq Nat.ofDigits_modEq
theorem ofDigits_mod (b k : ℕ) (L : List ℕ) : ofDigits b L % k = ofDigits (b % k) L % k :=
ofDigits_modEq b k L
#align nat.of_digits_mod Nat.ofDigits_mod
theorem ofDigits_mod_eq_head! (b : ℕ) (l : List ℕ) : ofDigits b l % b = l.head! % b := by
induction l <;> simp [Nat.ofDigits, Int.ModEq]
theorem head!_digits {b n : ℕ} (h : b ≠ 1) : (Nat.digits b n).head! = n % b := by
by_cases hb : 1 < b
· rcases n with _ | n
· simp
· nth_rw 2 [← Nat.ofDigits_digits b (n + 1)]
rw [Nat.ofDigits_mod_eq_head! _ _]
exact (Nat.mod_eq_of_lt (Nat.digits_lt_base hb <| List.head!_mem_self <|
Nat.digits_ne_nil_iff_ne_zero.mpr <| Nat.succ_ne_zero n)).symm
· rcases n with _ | _ <;> simp_all [show b = 0 by omega]
theorem ofDigits_zmodeq' (b b' : ℤ) (k : ℕ) (h : b ≡ b' [ZMOD k]) (L : List ℕ) :
ofDigits b L ≡ ofDigits b' L [ZMOD k] := by
induction' L with d L ih
· rfl
· dsimp [ofDigits]
dsimp [Int.ModEq] at *
conv_lhs => rw [Int.add_emod, Int.mul_emod, h, ih]
conv_rhs => rw [Int.add_emod, Int.mul_emod]
#align nat.of_digits_zmodeq' Nat.ofDigits_zmodeq'
theorem ofDigits_zmodeq (b : ℤ) (k : ℕ) (L : List ℕ) : ofDigits b L ≡ ofDigits (b % k) L [ZMOD k] :=
ofDigits_zmodeq' b (b % k) k (b.mod_modEq ↑k).symm L
#align nat.of_digits_zmodeq Nat.ofDigits_zmodeq
theorem ofDigits_zmod (b : ℤ) (k : ℕ) (L : List ℕ) : ofDigits b L % k = ofDigits (b % k) L % k :=
ofDigits_zmodeq b k L
#align nat.of_digits_zmod Nat.ofDigits_zmod
theorem modEq_digits_sum (b b' : ℕ) (h : b' % b = 1) (n : ℕ) : n ≡ (digits b' n).sum [MOD b] := by
rw [← ofDigits_one]
conv =>
congr
· skip
· rw [← ofDigits_digits b' n]
convert ofDigits_modEq b' b (digits b' n)
exact h.symm
#align nat.modeq_digits_sum Nat.modEq_digits_sum
theorem modEq_three_digits_sum (n : ℕ) : n ≡ (digits 10 n).sum [MOD 3] :=
modEq_digits_sum 3 10 (by norm_num) n
#align nat.modeq_three_digits_sum Nat.modEq_three_digits_sum
theorem modEq_nine_digits_sum (n : ℕ) : n ≡ (digits 10 n).sum [MOD 9] :=
modEq_digits_sum 9 10 (by norm_num) n
#align nat.modeq_nine_digits_sum Nat.modEq_nine_digits_sum
| Mathlib/Data/Nat/Digits.lean | 715 | 722 | theorem zmodeq_ofDigits_digits (b b' : ℕ) (c : ℤ) (h : b' ≡ c [ZMOD b]) (n : ℕ) :
n ≡ ofDigits c (digits b' n) [ZMOD b] := by |
conv =>
congr
· skip
· rw [← ofDigits_digits b' n]
rw [coe_int_ofDigits]
apply ofDigits_zmodeq' _ _ _ h
|
import Mathlib.Algebra.MvPolynomial.Monad
#align_import data.mv_polynomial.expand from "leanprover-community/mathlib"@"5da451b4c96b4c2e122c0325a7fce17d62ee46c6"
namespace MvPolynomial
variable {σ τ R S : Type*} [CommSemiring R] [CommSemiring S]
noncomputable def expand (p : ℕ) : MvPolynomial σ R →ₐ[R] MvPolynomial σ R :=
{ (eval₂Hom C fun i ↦ X i ^ p : MvPolynomial σ R →+* MvPolynomial σ R) with
commutes' := fun _ ↦ eval₂Hom_C _ _ _ }
#align mv_polynomial.expand MvPolynomial.expand
-- @[simp] -- Porting note (#10618): simp can prove this
theorem expand_C (p : ℕ) (r : R) : expand p (C r : MvPolynomial σ R) = C r :=
eval₂Hom_C _ _ _
set_option linter.uppercaseLean3 false in
#align mv_polynomial.expand_C MvPolynomial.expand_C
@[simp]
theorem expand_X (p : ℕ) (i : σ) : expand p (X i : MvPolynomial σ R) = X i ^ p :=
eval₂Hom_X' _ _ _
set_option linter.uppercaseLean3 false in
#align mv_polynomial.expand_X MvPolynomial.expand_X
@[simp]
theorem expand_monomial (p : ℕ) (d : σ →₀ ℕ) (r : R) :
expand p (monomial d r) = C r * ∏ i ∈ d.support, (X i ^ p) ^ d i :=
bind₁_monomial _ _ _
#align mv_polynomial.expand_monomial MvPolynomial.expand_monomial
| Mathlib/Algebra/MvPolynomial/Expand.lean | 53 | 55 | theorem expand_one_apply (f : MvPolynomial σ R) : expand 1 f = f := by |
simp only [expand, pow_one, eval₂Hom_eq_bind₂, bind₂_C_left, RingHom.toMonoidHom_eq_coe,
RingHom.coe_monoidHom_id, AlgHom.coe_mk, RingHom.coe_mk, MonoidHom.id_apply, RingHom.id_apply]
|
import Mathlib.Algebra.DirectSum.Module
import Mathlib.Analysis.Complex.Basic
import Mathlib.Analysis.Convex.Uniform
import Mathlib.Analysis.NormedSpace.Completion
import Mathlib.Analysis.NormedSpace.BoundedLinearMaps
#align_import analysis.inner_product_space.basic from "leanprover-community/mathlib"@"3f655f5297b030a87d641ad4e825af8d9679eb0b"
noncomputable section
open RCLike Real Filter
open Topology ComplexConjugate
open LinearMap (BilinForm)
variable {𝕜 E F : Type*} [RCLike 𝕜]
class Inner (𝕜 E : Type*) where
inner : E → E → 𝕜
#align has_inner Inner
export Inner (inner)
notation3:max "⟪" x ", " y "⟫_" 𝕜:max => @inner 𝕜 _ _ x y
class InnerProductSpace (𝕜 : Type*) (E : Type*) [RCLike 𝕜] [NormedAddCommGroup E] extends
NormedSpace 𝕜 E, Inner 𝕜 E where
norm_sq_eq_inner : ∀ x : E, ‖x‖ ^ 2 = re (inner x x)
conj_symm : ∀ x y, conj (inner y x) = inner x y
add_left : ∀ x y z, inner (x + y) z = inner x z + inner y z
smul_left : ∀ x y r, inner (r • x) y = conj r * inner x y
#align inner_product_space InnerProductSpace
-- @[nolint HasNonemptyInstance] porting note: I don't think we have this linter anymore
structure InnerProductSpace.Core (𝕜 : Type*) (F : Type*) [RCLike 𝕜] [AddCommGroup F]
[Module 𝕜 F] extends Inner 𝕜 F where
conj_symm : ∀ x y, conj (inner y x) = inner x y
nonneg_re : ∀ x, 0 ≤ re (inner x x)
definite : ∀ x, inner x x = 0 → x = 0
add_left : ∀ x y z, inner (x + y) z = inner x z + inner y z
smul_left : ∀ x y r, inner (r • x) y = conj r * inner x y
#align inner_product_space.core InnerProductSpace.Core
attribute [class] InnerProductSpace.Core
def InnerProductSpace.toCore [NormedAddCommGroup E] [c : InnerProductSpace 𝕜 E] :
InnerProductSpace.Core 𝕜 E :=
{ c with
nonneg_re := fun x => by
rw [← InnerProductSpace.norm_sq_eq_inner]
apply sq_nonneg
definite := fun x hx =>
norm_eq_zero.1 <| pow_eq_zero (n := 2) <| by
rw [InnerProductSpace.norm_sq_eq_inner (𝕜 := 𝕜) x, hx, map_zero] }
#align inner_product_space.to_core InnerProductSpace.toCore
namespace InnerProductSpace.Core
variable [AddCommGroup F] [Module 𝕜 F] [c : InnerProductSpace.Core 𝕜 F]
local notation "⟪" x ", " y "⟫" => @inner 𝕜 F _ x y
local notation "normSqK" => @RCLike.normSq 𝕜 _
local notation "reK" => @RCLike.re 𝕜 _
local notation "ext_iff" => @RCLike.ext_iff 𝕜 _
local postfix:90 "†" => starRingEnd _
def toInner' : Inner 𝕜 F :=
c.toInner
#align inner_product_space.core.to_has_inner' InnerProductSpace.Core.toInner'
attribute [local instance] toInner'
def normSq (x : F) :=
reK ⟪x, x⟫
#align inner_product_space.core.norm_sq InnerProductSpace.Core.normSq
local notation "normSqF" => @normSq 𝕜 F _ _ _ _
theorem inner_conj_symm (x y : F) : ⟪y, x⟫† = ⟪x, y⟫ :=
c.conj_symm x y
#align inner_product_space.core.inner_conj_symm InnerProductSpace.Core.inner_conj_symm
theorem inner_self_nonneg {x : F} : 0 ≤ re ⟪x, x⟫ :=
c.nonneg_re _
#align inner_product_space.core.inner_self_nonneg InnerProductSpace.Core.inner_self_nonneg
| Mathlib/Analysis/InnerProductSpace/Basic.lean | 211 | 213 | theorem inner_self_im (x : F) : im ⟪x, x⟫ = 0 := by |
rw [← @ofReal_inj 𝕜, im_eq_conj_sub]
simp [inner_conj_symm]
|
import Mathlib.Combinatorics.Enumerative.DoubleCounting
import Mathlib.Combinatorics.SimpleGraph.AdjMatrix
import Mathlib.Combinatorics.SimpleGraph.Basic
import Mathlib.Data.Set.Finite
#align_import combinatorics.simple_graph.strongly_regular from "leanprover-community/mathlib"@"2b35fc7bea4640cb75e477e83f32fbd538920822"
open Finset
universe u
namespace SimpleGraph
variable {V : Type u} [Fintype V] [DecidableEq V]
variable (G : SimpleGraph V) [DecidableRel G.Adj]
structure IsSRGWith (n k ℓ μ : ℕ) : Prop where
card : Fintype.card V = n
regular : G.IsRegularOfDegree k
of_adj : ∀ v w : V, G.Adj v w → Fintype.card (G.commonNeighbors v w) = ℓ
of_not_adj : Pairwise fun v w => ¬G.Adj v w → Fintype.card (G.commonNeighbors v w) = μ
set_option linter.uppercaseLean3 false in
#align simple_graph.is_SRG_with SimpleGraph.IsSRGWith
variable {G} {n k ℓ μ : ℕ}
theorem bot_strongly_regular : (⊥ : SimpleGraph V).IsSRGWith (Fintype.card V) 0 ℓ 0 where
card := rfl
regular := bot_degree
of_adj := fun v w h => h.elim
of_not_adj := fun v w _h => by
simp only [card_eq_zero, Fintype.card_ofFinset, forall_true_left, not_false_iff, bot_adj]
ext
simp [mem_commonNeighbors]
#align simple_graph.bot_strongly_regular SimpleGraph.bot_strongly_regular
theorem IsSRGWith.top :
(⊤ : SimpleGraph V).IsSRGWith (Fintype.card V) (Fintype.card V - 1) (Fintype.card V - 2) μ where
card := rfl
regular := IsRegularOfDegree.top
of_adj := fun v w h => by
rw [card_commonNeighbors_top]
exact h
of_not_adj := fun v w h h' => False.elim (h' ((top_adj v w).2 h))
set_option linter.uppercaseLean3 false in
#align simple_graph.is_SRG_with.top SimpleGraph.IsSRGWith.top
theorem IsSRGWith.card_neighborFinset_union_eq {v w : V} (h : G.IsSRGWith n k ℓ μ) :
(G.neighborFinset v ∪ G.neighborFinset w).card =
2 * k - Fintype.card (G.commonNeighbors v w) := by
apply Nat.add_right_cancel (m := Fintype.card (G.commonNeighbors v w))
rw [Nat.sub_add_cancel, ← Set.toFinset_card]
-- Porting note: Set.toFinset_inter needs workaround to use unification to solve for one of the
-- instance arguments:
· simp [commonNeighbors, @Set.toFinset_inter _ _ _ _ _ _ (_),
← neighborFinset_def, Finset.card_union_add_card_inter, card_neighborFinset_eq_degree,
h.regular.degree_eq, two_mul]
· apply le_trans (card_commonNeighbors_le_degree_left _ _ _)
simp [h.regular.degree_eq, two_mul]
set_option linter.uppercaseLean3 false in
#align simple_graph.is_SRG_with.card_neighbor_finset_union_eq SimpleGraph.IsSRGWith.card_neighborFinset_union_eq
theorem IsSRGWith.card_neighborFinset_union_of_not_adj {v w : V} (h : G.IsSRGWith n k ℓ μ)
(hne : v ≠ w) (ha : ¬G.Adj v w) :
(G.neighborFinset v ∪ G.neighborFinset w).card = 2 * k - μ := by
rw [← h.of_not_adj hne ha]
apply h.card_neighborFinset_union_eq
set_option linter.uppercaseLean3 false in
#align simple_graph.is_SRG_with.card_neighbor_finset_union_of_not_adj SimpleGraph.IsSRGWith.card_neighborFinset_union_of_not_adj
theorem IsSRGWith.card_neighborFinset_union_of_adj {v w : V} (h : G.IsSRGWith n k ℓ μ)
(ha : G.Adj v w) : (G.neighborFinset v ∪ G.neighborFinset w).card = 2 * k - ℓ := by
rw [← h.of_adj v w ha]
apply h.card_neighborFinset_union_eq
set_option linter.uppercaseLean3 false in
#align simple_graph.is_SRG_with.card_neighbor_finset_union_of_adj SimpleGraph.IsSRGWith.card_neighborFinset_union_of_adj
theorem compl_neighborFinset_sdiff_inter_eq {v w : V} :
(G.neighborFinset v)ᶜ \ {v} ∩ ((G.neighborFinset w)ᶜ \ {w}) =
((G.neighborFinset v)ᶜ ∩ (G.neighborFinset w)ᶜ) \ ({w} ∪ {v}) := by
ext
rw [← not_iff_not]
simp [imp_iff_not_or, or_assoc, or_comm, or_left_comm]
#align simple_graph.compl_neighbor_finset_sdiff_inter_eq SimpleGraph.compl_neighborFinset_sdiff_inter_eq
theorem sdiff_compl_neighborFinset_inter_eq {v w : V} (h : G.Adj v w) :
((G.neighborFinset v)ᶜ ∩ (G.neighborFinset w)ᶜ) \ ({w} ∪ {v}) =
(G.neighborFinset v)ᶜ ∩ (G.neighborFinset w)ᶜ := by
ext
simp only [and_imp, mem_union, mem_sdiff, mem_compl, and_iff_left_iff_imp, mem_neighborFinset,
mem_inter, mem_singleton]
rintro hnv hnw (rfl | rfl)
· exact hnv h
· apply hnw
rwa [adj_comm]
#align simple_graph.sdiff_compl_neighbor_finset_inter_eq SimpleGraph.sdiff_compl_neighborFinset_inter_eq
theorem IsSRGWith.compl_is_regular (h : G.IsSRGWith n k ℓ μ) :
Gᶜ.IsRegularOfDegree (n - k - 1) := by
rw [← h.card, Nat.sub_sub, add_comm, ← Nat.sub_sub]
exact h.regular.compl
set_option linter.uppercaseLean3 false in
#align simple_graph.is_SRG_with.compl_is_regular SimpleGraph.IsSRGWith.compl_is_regular
theorem IsSRGWith.card_commonNeighbors_eq_of_adj_compl (h : G.IsSRGWith n k ℓ μ) {v w : V}
(ha : Gᶜ.Adj v w) : Fintype.card (Gᶜ.commonNeighbors v w) = n - (2 * k - μ) - 2 := by
simp only [← Set.toFinset_card, commonNeighbors, Set.toFinset_inter, neighborSet_compl,
Set.toFinset_diff, Set.toFinset_singleton, Set.toFinset_compl, ← neighborFinset_def]
simp_rw [compl_neighborFinset_sdiff_inter_eq]
have hne : v ≠ w := ne_of_adj _ ha
rw [compl_adj] at ha
rw [card_sdiff, ← insert_eq, card_insert_of_not_mem, card_singleton, ← Finset.compl_union]
· rw [card_compl, h.card_neighborFinset_union_of_not_adj hne ha.2, ← h.card]
· simp only [hne.symm, not_false_iff, mem_singleton]
· intro u
simp only [mem_union, mem_compl, mem_neighborFinset, mem_inter, mem_singleton]
rintro (rfl | rfl) <;> simpa [adj_comm] using ha.2
set_option linter.uppercaseLean3 false in
#align simple_graph.is_SRG_with.card_common_neighbors_eq_of_adj_compl SimpleGraph.IsSRGWith.card_commonNeighbors_eq_of_adj_compl
| Mathlib/Combinatorics/SimpleGraph/StronglyRegular.lean | 160 | 168 | theorem IsSRGWith.card_commonNeighbors_eq_of_not_adj_compl (h : G.IsSRGWith n k ℓ μ) {v w : V}
(hn : v ≠ w) (hna : ¬Gᶜ.Adj v w) :
Fintype.card (Gᶜ.commonNeighbors v w) = n - (2 * k - ℓ) := by |
simp only [← Set.toFinset_card, commonNeighbors, Set.toFinset_inter, neighborSet_compl,
Set.toFinset_diff, Set.toFinset_singleton, Set.toFinset_compl, ← neighborFinset_def]
simp only [not_and, Classical.not_not, compl_adj] at hna
have h2' := hna hn
simp_rw [compl_neighborFinset_sdiff_inter_eq, sdiff_compl_neighborFinset_inter_eq h2']
rwa [← Finset.compl_union, card_compl, h.card_neighborFinset_union_of_adj, ← h.card]
|
import Mathlib.Analysis.Normed.Group.Pointwise
import Mathlib.Analysis.NormedSpace.Real
#align_import analysis.normed_space.pointwise from "leanprover-community/mathlib"@"bc91ed7093bf098d253401e69df601fc33dde156"
open Metric Set
open Pointwise Topology
variable {𝕜 E : Type*}
variable [NormedField 𝕜]
section SeminormedAddCommGroup
variable [SeminormedAddCommGroup E] [NormedSpace 𝕜 E]
theorem smul_ball {c : 𝕜} (hc : c ≠ 0) (x : E) (r : ℝ) : c • ball x r = ball (c • x) (‖c‖ * r) := by
ext y
rw [mem_smul_set_iff_inv_smul_mem₀ hc]
conv_lhs => rw [← inv_smul_smul₀ hc x]
simp [← div_eq_inv_mul, div_lt_iff (norm_pos_iff.2 hc), mul_comm _ r, dist_smul₀]
#align smul_ball smul_ball
theorem smul_unitBall {c : 𝕜} (hc : c ≠ 0) : c • ball (0 : E) (1 : ℝ) = ball (0 : E) ‖c‖ := by
rw [_root_.smul_ball hc, smul_zero, mul_one]
#align smul_unit_ball smul_unitBall
theorem smul_sphere' {c : 𝕜} (hc : c ≠ 0) (x : E) (r : ℝ) :
c • sphere x r = sphere (c • x) (‖c‖ * r) := by
ext y
rw [mem_smul_set_iff_inv_smul_mem₀ hc]
conv_lhs => rw [← inv_smul_smul₀ hc x]
simp only [mem_sphere, dist_smul₀, norm_inv, ← div_eq_inv_mul, div_eq_iff (norm_pos_iff.2 hc).ne',
mul_comm r]
#align smul_sphere' smul_sphere'
theorem smul_closedBall' {c : 𝕜} (hc : c ≠ 0) (x : E) (r : ℝ) :
c • closedBall x r = closedBall (c • x) (‖c‖ * r) := by
simp only [← ball_union_sphere, Set.smul_set_union, _root_.smul_ball hc, smul_sphere' hc]
#align smul_closed_ball' smul_closedBall'
theorem set_smul_sphere_zero {s : Set 𝕜} (hs : 0 ∉ s) (r : ℝ) :
s • sphere (0 : E) r = (‖·‖) ⁻¹' ((‖·‖ * r) '' s) :=
calc
s • sphere (0 : E) r = ⋃ c ∈ s, c • sphere (0 : E) r := iUnion_smul_left_image.symm
_ = ⋃ c ∈ s, sphere (0 : E) (‖c‖ * r) := iUnion₂_congr fun c hc ↦ by
rw [smul_sphere' (ne_of_mem_of_not_mem hc hs), smul_zero]
_ = (‖·‖) ⁻¹' ((‖·‖ * r) '' s) := by ext; simp [eq_comm]
theorem Bornology.IsBounded.smul₀ {s : Set E} (hs : IsBounded s) (c : 𝕜) : IsBounded (c • s) :=
(lipschitzWith_smul c).isBounded_image hs
#align metric.bounded.smul Bornology.IsBounded.smul₀
theorem eventually_singleton_add_smul_subset {x : E} {s : Set E} (hs : Bornology.IsBounded s)
{u : Set E} (hu : u ∈ 𝓝 x) : ∀ᶠ r in 𝓝 (0 : 𝕜), {x} + r • s ⊆ u := by
obtain ⟨ε, εpos, hε⟩ : ∃ ε : ℝ, 0 < ε ∧ closedBall x ε ⊆ u := nhds_basis_closedBall.mem_iff.1 hu
obtain ⟨R, Rpos, hR⟩ : ∃ R : ℝ, 0 < R ∧ s ⊆ closedBall 0 R := hs.subset_closedBall_lt 0 0
have : Metric.closedBall (0 : 𝕜) (ε / R) ∈ 𝓝 (0 : 𝕜) := closedBall_mem_nhds _ (div_pos εpos Rpos)
filter_upwards [this] with r hr
simp only [image_add_left, singleton_add]
intro y hy
obtain ⟨z, zs, hz⟩ : ∃ z : E, z ∈ s ∧ r • z = -x + y := by simpa [mem_smul_set] using hy
have I : ‖r • z‖ ≤ ε :=
calc
‖r • z‖ = ‖r‖ * ‖z‖ := norm_smul _ _
_ ≤ ε / R * R :=
(mul_le_mul (mem_closedBall_zero_iff.1 hr) (mem_closedBall_zero_iff.1 (hR zs))
(norm_nonneg _) (div_pos εpos Rpos).le)
_ = ε := by field_simp
have : y = x + r • z := by simp only [hz, add_neg_cancel_left]
apply hε
simpa only [this, dist_eq_norm, add_sub_cancel_left, mem_closedBall] using I
#align eventually_singleton_add_smul_subset eventually_singleton_add_smul_subset
variable [NormedSpace ℝ E] {x y z : E} {δ ε : ℝ}
theorem smul_unitBall_of_pos {r : ℝ} (hr : 0 < r) : r • ball (0 : E) 1 = ball (0 : E) r := by
rw [smul_unitBall hr.ne', Real.norm_of_nonneg hr.le]
#align smul_unit_ball_of_pos smul_unitBall_of_pos
lemma Ioo_smul_sphere_zero {a b r : ℝ} (ha : 0 ≤ a) (hr : 0 < r) :
Ioo a b • sphere (0 : E) r = ball 0 (b * r) \ closedBall 0 (a * r) := by
have : EqOn (‖·‖) id (Ioo a b) := fun x hx ↦ abs_of_pos (ha.trans_lt hx.1)
rw [set_smul_sphere_zero (by simp [ha.not_lt]), ← image_image (· * r), this.image_eq, image_id,
image_mul_right_Ioo _ _ hr]
ext x; simp [and_comm]
-- This is also true for `ℚ`-normed spaces
theorem exists_dist_eq (x z : E) {a b : ℝ} (ha : 0 ≤ a) (hb : 0 ≤ b) (hab : a + b = 1) :
∃ y, dist x y = b * dist x z ∧ dist y z = a * dist x z := by
use a • x + b • z
nth_rw 1 [← one_smul ℝ x]
nth_rw 4 [← one_smul ℝ z]
simp [dist_eq_norm, ← hab, add_smul, ← smul_sub, norm_smul_of_nonneg, ha, hb]
#align exists_dist_eq exists_dist_eq
theorem exists_dist_le_le (hδ : 0 ≤ δ) (hε : 0 ≤ ε) (h : dist x z ≤ ε + δ) :
∃ y, dist x y ≤ δ ∧ dist y z ≤ ε := by
obtain rfl | hε' := hε.eq_or_lt
· exact ⟨z, by rwa [zero_add] at h, (dist_self _).le⟩
have hεδ := add_pos_of_pos_of_nonneg hε' hδ
refine (exists_dist_eq x z (div_nonneg hε <| add_nonneg hε hδ)
(div_nonneg hδ <| add_nonneg hε hδ) <| by
rw [← add_div, div_self hεδ.ne']).imp
fun y hy => ?_
rw [hy.1, hy.2, div_mul_comm, div_mul_comm ε]
rw [← div_le_one hεδ] at h
exact ⟨mul_le_of_le_one_left hδ h, mul_le_of_le_one_left hε h⟩
#align exists_dist_le_le exists_dist_le_le
-- This is also true for `ℚ`-normed spaces
theorem exists_dist_le_lt (hδ : 0 ≤ δ) (hε : 0 < ε) (h : dist x z < ε + δ) :
∃ y, dist x y ≤ δ ∧ dist y z < ε := by
refine (exists_dist_eq x z (div_nonneg hε.le <| add_nonneg hε.le hδ)
(div_nonneg hδ <| add_nonneg hε.le hδ) <| by
rw [← add_div, div_self (add_pos_of_pos_of_nonneg hε hδ).ne']).imp
fun y hy => ?_
rw [hy.1, hy.2, div_mul_comm, div_mul_comm ε]
rw [← div_lt_one (add_pos_of_pos_of_nonneg hε hδ)] at h
exact ⟨mul_le_of_le_one_left hδ h.le, mul_lt_of_lt_one_left hε h⟩
#align exists_dist_le_lt exists_dist_le_lt
-- This is also true for `ℚ`-normed spaces
theorem exists_dist_lt_le (hδ : 0 < δ) (hε : 0 ≤ ε) (h : dist x z < ε + δ) :
∃ y, dist x y < δ ∧ dist y z ≤ ε := by
obtain ⟨y, yz, xy⟩ :=
exists_dist_le_lt hε hδ (show dist z x < δ + ε by simpa only [dist_comm, add_comm] using h)
exact ⟨y, by simp [dist_comm x y, dist_comm y z, *]⟩
#align exists_dist_lt_le exists_dist_lt_le
-- This is also true for `ℚ`-normed spaces
theorem exists_dist_lt_lt (hδ : 0 < δ) (hε : 0 < ε) (h : dist x z < ε + δ) :
∃ y, dist x y < δ ∧ dist y z < ε := by
refine (exists_dist_eq x z (div_nonneg hε.le <| add_nonneg hε.le hδ.le)
(div_nonneg hδ.le <| add_nonneg hε.le hδ.le) <| by
rw [← add_div, div_self (add_pos hε hδ).ne']).imp
fun y hy => ?_
rw [hy.1, hy.2, div_mul_comm, div_mul_comm ε]
rw [← div_lt_one (add_pos hε hδ)] at h
exact ⟨mul_lt_of_lt_one_left hδ h, mul_lt_of_lt_one_left hε h⟩
#align exists_dist_lt_lt exists_dist_lt_lt
-- This is also true for `ℚ`-normed spaces
theorem disjoint_ball_ball_iff (hδ : 0 < δ) (hε : 0 < ε) :
Disjoint (ball x δ) (ball y ε) ↔ δ + ε ≤ dist x y := by
refine ⟨fun h => le_of_not_lt fun hxy => ?_, ball_disjoint_ball⟩
rw [add_comm] at hxy
obtain ⟨z, hxz, hzy⟩ := exists_dist_lt_lt hδ hε hxy
rw [dist_comm] at hxz
exact h.le_bot ⟨hxz, hzy⟩
#align disjoint_ball_ball_iff disjoint_ball_ball_iff
-- This is also true for `ℚ`-normed spaces
theorem disjoint_ball_closedBall_iff (hδ : 0 < δ) (hε : 0 ≤ ε) :
Disjoint (ball x δ) (closedBall y ε) ↔ δ + ε ≤ dist x y := by
refine ⟨fun h => le_of_not_lt fun hxy => ?_, ball_disjoint_closedBall⟩
rw [add_comm] at hxy
obtain ⟨z, hxz, hzy⟩ := exists_dist_lt_le hδ hε hxy
rw [dist_comm] at hxz
exact h.le_bot ⟨hxz, hzy⟩
#align disjoint_ball_closed_ball_iff disjoint_ball_closedBall_iff
-- This is also true for `ℚ`-normed spaces
theorem disjoint_closedBall_ball_iff (hδ : 0 ≤ δ) (hε : 0 < ε) :
Disjoint (closedBall x δ) (ball y ε) ↔ δ + ε ≤ dist x y := by
rw [disjoint_comm, disjoint_ball_closedBall_iff hε hδ, add_comm, dist_comm]
#align disjoint_closed_ball_ball_iff disjoint_closedBall_ball_iff
theorem disjoint_closedBall_closedBall_iff (hδ : 0 ≤ δ) (hε : 0 ≤ ε) :
Disjoint (closedBall x δ) (closedBall y ε) ↔ δ + ε < dist x y := by
refine ⟨fun h => lt_of_not_ge fun hxy => ?_, closedBall_disjoint_closedBall⟩
rw [add_comm] at hxy
obtain ⟨z, hxz, hzy⟩ := exists_dist_le_le hδ hε hxy
rw [dist_comm] at hxz
exact h.le_bot ⟨hxz, hzy⟩
#align disjoint_closed_ball_closed_ball_iff disjoint_closedBall_closedBall_iff
open EMetric ENNReal
@[simp]
theorem infEdist_thickening (hδ : 0 < δ) (s : Set E) (x : E) :
infEdist x (thickening δ s) = infEdist x s - ENNReal.ofReal δ := by
obtain hs | hs := lt_or_le (infEdist x s) (ENNReal.ofReal δ)
· rw [infEdist_zero_of_mem, tsub_eq_zero_of_le hs.le]
exact hs
refine (tsub_le_iff_right.2 infEdist_le_infEdist_thickening_add).antisymm' ?_
refine le_sub_of_add_le_right ofReal_ne_top ?_
refine le_infEdist.2 fun z hz => le_of_forall_lt' fun r h => ?_
cases' r with r
· exact add_lt_top.2 ⟨lt_top_iff_ne_top.2 <| infEdist_ne_top ⟨z, self_subset_thickening hδ _ hz⟩,
ofReal_lt_top⟩
have hr : 0 < ↑r - δ := by
refine sub_pos_of_lt ?_
have := hs.trans_lt ((infEdist_le_edist_of_mem hz).trans_lt h)
rw [ofReal_eq_coe_nnreal hδ.le] at this
exact mod_cast this
rw [edist_lt_coe, ← dist_lt_coe, ← add_sub_cancel δ ↑r] at h
obtain ⟨y, hxy, hyz⟩ := exists_dist_lt_lt hr hδ h
refine (ENNReal.add_lt_add_right ofReal_ne_top <|
infEdist_lt_iff.2 ⟨_, mem_thickening_iff.2 ⟨_, hz, hyz⟩, edist_lt_ofReal.2 hxy⟩).trans_le ?_
rw [← ofReal_add hr.le hδ.le, sub_add_cancel, ofReal_coe_nnreal]
#align inf_edist_thickening infEdist_thickening
@[simp]
theorem thickening_thickening (hε : 0 < ε) (hδ : 0 < δ) (s : Set E) :
thickening ε (thickening δ s) = thickening (ε + δ) s :=
(thickening_thickening_subset _ _ _).antisymm fun x => by
simp_rw [mem_thickening_iff]
rintro ⟨z, hz, hxz⟩
rw [add_comm] at hxz
obtain ⟨y, hxy, hyz⟩ := exists_dist_lt_lt hε hδ hxz
exact ⟨y, ⟨_, hz, hyz⟩, hxy⟩
#align thickening_thickening thickening_thickening
@[simp]
theorem cthickening_thickening (hε : 0 ≤ ε) (hδ : 0 < δ) (s : Set E) :
cthickening ε (thickening δ s) = cthickening (ε + δ) s :=
(cthickening_thickening_subset hε _ _).antisymm fun x => by
simp_rw [mem_cthickening_iff, ENNReal.ofReal_add hε hδ.le, infEdist_thickening hδ]
exact tsub_le_iff_right.2
#align cthickening_thickening cthickening_thickening
-- Note: `interior (cthickening δ s) ≠ thickening δ s` in general
@[simp]
theorem closure_thickening (hδ : 0 < δ) (s : Set E) :
closure (thickening δ s) = cthickening δ s := by
rw [← cthickening_zero, cthickening_thickening le_rfl hδ, zero_add]
#align closure_thickening closure_thickening
@[simp]
theorem infEdist_cthickening (δ : ℝ) (s : Set E) (x : E) :
infEdist x (cthickening δ s) = infEdist x s - ENNReal.ofReal δ := by
obtain hδ | hδ := le_or_lt δ 0
· rw [cthickening_of_nonpos hδ, infEdist_closure, ofReal_of_nonpos hδ, tsub_zero]
· rw [← closure_thickening hδ, infEdist_closure, infEdist_thickening hδ]
#align inf_edist_cthickening infEdist_cthickening
@[simp]
theorem thickening_cthickening (hε : 0 < ε) (hδ : 0 ≤ δ) (s : Set E) :
thickening ε (cthickening δ s) = thickening (ε + δ) s := by
obtain rfl | hδ := hδ.eq_or_lt
· rw [cthickening_zero, thickening_closure, add_zero]
· rw [← closure_thickening hδ, thickening_closure, thickening_thickening hε hδ]
#align thickening_cthickening thickening_cthickening
@[simp]
theorem cthickening_cthickening (hε : 0 ≤ ε) (hδ : 0 ≤ δ) (s : Set E) :
cthickening ε (cthickening δ s) = cthickening (ε + δ) s :=
(cthickening_cthickening_subset hε hδ _).antisymm fun x => by
simp_rw [mem_cthickening_iff, ENNReal.ofReal_add hε hδ, infEdist_cthickening]
exact tsub_le_iff_right.2
#align cthickening_cthickening cthickening_cthickening
@[simp]
theorem thickening_ball (hε : 0 < ε) (hδ : 0 < δ) (x : E) :
thickening ε (ball x δ) = ball x (ε + δ) := by
rw [← thickening_singleton, thickening_thickening hε hδ, thickening_singleton]
#align thickening_ball thickening_ball
@[simp]
theorem thickening_closedBall (hε : 0 < ε) (hδ : 0 ≤ δ) (x : E) :
thickening ε (closedBall x δ) = ball x (ε + δ) := by
rw [← cthickening_singleton _ hδ, thickening_cthickening hε hδ, thickening_singleton]
#align thickening_closed_ball thickening_closedBall
@[simp]
theorem cthickening_ball (hε : 0 ≤ ε) (hδ : 0 < δ) (x : E) :
cthickening ε (ball x δ) = closedBall x (ε + δ) := by
rw [← thickening_singleton, cthickening_thickening hε hδ,
cthickening_singleton _ (add_nonneg hε hδ.le)]
#align cthickening_ball cthickening_ball
@[simp]
theorem cthickening_closedBall (hε : 0 ≤ ε) (hδ : 0 ≤ δ) (x : E) :
cthickening ε (closedBall x δ) = closedBall x (ε + δ) := by
rw [← cthickening_singleton _ hδ, cthickening_cthickening hε hδ,
cthickening_singleton _ (add_nonneg hε hδ)]
#align cthickening_closed_ball cthickening_closedBall
theorem ball_add_ball (hε : 0 < ε) (hδ : 0 < δ) (a b : E) :
ball a ε + ball b δ = ball (a + b) (ε + δ) := by
rw [ball_add, thickening_ball hε hδ b, Metric.vadd_ball, vadd_eq_add]
#align ball_add_ball ball_add_ball
theorem ball_sub_ball (hε : 0 < ε) (hδ : 0 < δ) (a b : E) :
ball a ε - ball b δ = ball (a - b) (ε + δ) := by
simp_rw [sub_eq_add_neg, neg_ball, ball_add_ball hε hδ]
#align ball_sub_ball ball_sub_ball
theorem ball_add_closedBall (hε : 0 < ε) (hδ : 0 ≤ δ) (a b : E) :
ball a ε + closedBall b δ = ball (a + b) (ε + δ) := by
rw [ball_add, thickening_closedBall hε hδ b, Metric.vadd_ball, vadd_eq_add]
#align ball_add_closed_ball ball_add_closedBall
| Mathlib/Analysis/NormedSpace/Pointwise.lean | 368 | 370 | theorem ball_sub_closedBall (hε : 0 < ε) (hδ : 0 ≤ δ) (a b : E) :
ball a ε - closedBall b δ = ball (a - b) (ε + δ) := by |
simp_rw [sub_eq_add_neg, neg_closedBall, ball_add_closedBall hε hδ]
|
import Mathlib.Data.Nat.Defs
import Mathlib.Data.Option.Basic
import Mathlib.Data.List.Defs
import Mathlib.Init.Data.List.Basic
import Mathlib.Init.Data.List.Instances
import Mathlib.Init.Data.List.Lemmas
import Mathlib.Logic.Unique
import Mathlib.Order.Basic
import Mathlib.Tactic.Common
#align_import data.list.basic from "leanprover-community/mathlib"@"65a1391a0106c9204fe45bc73a039f056558cb83"
assert_not_exists Set.range
assert_not_exists GroupWithZero
assert_not_exists Ring
open Function
open Nat hiding one_pos
namespace List
universe u v w
variable {ι : Type*} {α : Type u} {β : Type v} {γ : Type w} {l₁ l₂ : List α}
-- Porting note: Delete this attribute
-- attribute [inline] List.head!
instance uniqueOfIsEmpty [IsEmpty α] : Unique (List α) :=
{ instInhabitedList with
uniq := fun l =>
match l with
| [] => rfl
| a :: _ => isEmptyElim a }
#align list.unique_of_is_empty List.uniqueOfIsEmpty
instance : Std.LawfulIdentity (α := List α) Append.append [] where
left_id := nil_append
right_id := append_nil
instance : Std.Associative (α := List α) Append.append where
assoc := append_assoc
#align list.cons_ne_nil List.cons_ne_nil
#align list.cons_ne_self List.cons_ne_self
#align list.head_eq_of_cons_eq List.head_eq_of_cons_eqₓ -- implicits order
#align list.tail_eq_of_cons_eq List.tail_eq_of_cons_eqₓ -- implicits order
@[simp] theorem cons_injective {a : α} : Injective (cons a) := fun _ _ => tail_eq_of_cons_eq
#align list.cons_injective List.cons_injective
#align list.cons_inj List.cons_inj
#align list.cons_eq_cons List.cons_eq_cons
theorem singleton_injective : Injective fun a : α => [a] := fun _ _ h => (cons_eq_cons.1 h).1
#align list.singleton_injective List.singleton_injective
theorem singleton_inj {a b : α} : [a] = [b] ↔ a = b :=
singleton_injective.eq_iff
#align list.singleton_inj List.singleton_inj
#align list.exists_cons_of_ne_nil List.exists_cons_of_ne_nil
theorem set_of_mem_cons (l : List α) (a : α) : { x | x ∈ a :: l } = insert a { x | x ∈ l } :=
Set.ext fun _ => mem_cons
#align list.set_of_mem_cons List.set_of_mem_cons
#align list.mem_singleton_self List.mem_singleton_self
#align list.eq_of_mem_singleton List.eq_of_mem_singleton
#align list.mem_singleton List.mem_singleton
#align list.mem_of_mem_cons_of_mem List.mem_of_mem_cons_of_mem
theorem _root_.Decidable.List.eq_or_ne_mem_of_mem [DecidableEq α]
{a b : α} {l : List α} (h : a ∈ b :: l) : a = b ∨ a ≠ b ∧ a ∈ l := by
by_cases hab : a = b
· exact Or.inl hab
· exact ((List.mem_cons.1 h).elim Or.inl (fun h => Or.inr ⟨hab, h⟩))
#align decidable.list.eq_or_ne_mem_of_mem Decidable.List.eq_or_ne_mem_of_mem
#align list.eq_or_ne_mem_of_mem List.eq_or_ne_mem_of_mem
#align list.not_mem_append List.not_mem_append
#align list.ne_nil_of_mem List.ne_nil_of_mem
lemma mem_pair {a b c : α} : a ∈ [b, c] ↔ a = b ∨ a = c := by
rw [mem_cons, mem_singleton]
@[deprecated (since := "2024-03-23")] alias mem_split := append_of_mem
#align list.mem_split List.append_of_mem
#align list.mem_of_ne_of_mem List.mem_of_ne_of_mem
#align list.ne_of_not_mem_cons List.ne_of_not_mem_cons
#align list.not_mem_of_not_mem_cons List.not_mem_of_not_mem_cons
#align list.not_mem_cons_of_ne_of_not_mem List.not_mem_cons_of_ne_of_not_mem
#align list.ne_and_not_mem_of_not_mem_cons List.ne_and_not_mem_of_not_mem_cons
#align list.mem_map List.mem_map
#align list.exists_of_mem_map List.exists_of_mem_map
#align list.mem_map_of_mem List.mem_map_of_memₓ -- implicits order
-- The simpNF linter says that the LHS can be simplified via `List.mem_map`.
-- However this is a higher priority lemma.
-- https://github.com/leanprover/std4/issues/207
@[simp 1100, nolint simpNF]
theorem mem_map_of_injective {f : α → β} (H : Injective f) {a : α} {l : List α} :
f a ∈ map f l ↔ a ∈ l :=
⟨fun m => let ⟨_, m', e⟩ := exists_of_mem_map m; H e ▸ m', mem_map_of_mem _⟩
#align list.mem_map_of_injective List.mem_map_of_injective
@[simp]
theorem _root_.Function.Involutive.exists_mem_and_apply_eq_iff {f : α → α}
(hf : Function.Involutive f) (x : α) (l : List α) : (∃ y : α, y ∈ l ∧ f y = x) ↔ f x ∈ l :=
⟨by rintro ⟨y, h, rfl⟩; rwa [hf y], fun h => ⟨f x, h, hf _⟩⟩
#align function.involutive.exists_mem_and_apply_eq_iff Function.Involutive.exists_mem_and_apply_eq_iff
theorem mem_map_of_involutive {f : α → α} (hf : Involutive f) {a : α} {l : List α} :
a ∈ map f l ↔ f a ∈ l := by rw [mem_map, hf.exists_mem_and_apply_eq_iff]
#align list.mem_map_of_involutive List.mem_map_of_involutive
#align list.forall_mem_map_iff List.forall_mem_map_iffₓ -- universe order
#align list.map_eq_nil List.map_eq_nilₓ -- universe order
attribute [simp] List.mem_join
#align list.mem_join List.mem_join
#align list.exists_of_mem_join List.exists_of_mem_join
#align list.mem_join_of_mem List.mem_join_of_memₓ -- implicits order
attribute [simp] List.mem_bind
#align list.mem_bind List.mem_bindₓ -- implicits order
-- Porting note: bExists in Lean3, And in Lean4
#align list.exists_of_mem_bind List.exists_of_mem_bindₓ -- implicits order
#align list.mem_bind_of_mem List.mem_bind_of_memₓ -- implicits order
#align list.bind_map List.bind_mapₓ -- implicits order
theorem map_bind (g : β → List γ) (f : α → β) :
∀ l : List α, (List.map f l).bind g = l.bind fun a => g (f a)
| [] => rfl
| a :: l => by simp only [cons_bind, map_cons, map_bind _ _ l]
#align list.map_bind List.map_bind
#align list.length_eq_zero List.length_eq_zero
#align list.length_singleton List.length_singleton
#align list.length_pos_of_mem List.length_pos_of_mem
#align list.exists_mem_of_length_pos List.exists_mem_of_length_pos
#align list.length_pos_iff_exists_mem List.length_pos_iff_exists_mem
alias ⟨ne_nil_of_length_pos, length_pos_of_ne_nil⟩ := length_pos
#align list.ne_nil_of_length_pos List.ne_nil_of_length_pos
#align list.length_pos_of_ne_nil List.length_pos_of_ne_nil
theorem length_pos_iff_ne_nil {l : List α} : 0 < length l ↔ l ≠ [] :=
⟨ne_nil_of_length_pos, length_pos_of_ne_nil⟩
#align list.length_pos_iff_ne_nil List.length_pos_iff_ne_nil
#align list.exists_mem_of_ne_nil List.exists_mem_of_ne_nil
#align list.length_eq_one List.length_eq_one
theorem exists_of_length_succ {n} : ∀ l : List α, l.length = n + 1 → ∃ h t, l = h :: t
| [], H => absurd H.symm <| succ_ne_zero n
| h :: t, _ => ⟨h, t, rfl⟩
#align list.exists_of_length_succ List.exists_of_length_succ
@[simp] lemma length_injective_iff : Injective (List.length : List α → ℕ) ↔ Subsingleton α := by
constructor
· intro h; refine ⟨fun x y => ?_⟩; (suffices [x] = [y] by simpa using this); apply h; rfl
· intros hα l1 l2 hl
induction l1 generalizing l2 <;> cases l2
· rfl
· cases hl
· cases hl
· next ih _ _ =>
congr
· exact Subsingleton.elim _ _
· apply ih; simpa using hl
#align list.length_injective_iff List.length_injective_iff
@[simp default+1] -- Porting note: this used to be just @[simp]
lemma length_injective [Subsingleton α] : Injective (length : List α → ℕ) :=
length_injective_iff.mpr inferInstance
#align list.length_injective List.length_injective
theorem length_eq_two {l : List α} : l.length = 2 ↔ ∃ a b, l = [a, b] :=
⟨fun _ => let [a, b] := l; ⟨a, b, rfl⟩, fun ⟨_, _, e⟩ => e ▸ rfl⟩
#align list.length_eq_two List.length_eq_two
theorem length_eq_three {l : List α} : l.length = 3 ↔ ∃ a b c, l = [a, b, c] :=
⟨fun _ => let [a, b, c] := l; ⟨a, b, c, rfl⟩, fun ⟨_, _, _, e⟩ => e ▸ rfl⟩
#align list.length_eq_three List.length_eq_three
#align list.sublist.length_le List.Sublist.length_le
-- ADHOC Porting note: instance from Lean3 core
instance instSingletonList : Singleton α (List α) := ⟨fun x => [x]⟩
#align list.has_singleton List.instSingletonList
-- ADHOC Porting note: instance from Lean3 core
instance [DecidableEq α] : Insert α (List α) := ⟨List.insert⟩
-- ADHOC Porting note: instance from Lean3 core
instance [DecidableEq α] : LawfulSingleton α (List α) :=
{ insert_emptyc_eq := fun x =>
show (if x ∈ ([] : List α) then [] else [x]) = [x] from if_neg (not_mem_nil _) }
#align list.empty_eq List.empty_eq
theorem singleton_eq (x : α) : ({x} : List α) = [x] :=
rfl
#align list.singleton_eq List.singleton_eq
theorem insert_neg [DecidableEq α] {x : α} {l : List α} (h : x ∉ l) :
Insert.insert x l = x :: l :=
insert_of_not_mem h
#align list.insert_neg List.insert_neg
theorem insert_pos [DecidableEq α] {x : α} {l : List α} (h : x ∈ l) : Insert.insert x l = l :=
insert_of_mem h
#align list.insert_pos List.insert_pos
theorem doubleton_eq [DecidableEq α] {x y : α} (h : x ≠ y) : ({x, y} : List α) = [x, y] := by
rw [insert_neg, singleton_eq]
rwa [singleton_eq, mem_singleton]
#align list.doubleton_eq List.doubleton_eq
#align list.forall_mem_nil List.forall_mem_nil
#align list.forall_mem_cons List.forall_mem_cons
theorem forall_mem_of_forall_mem_cons {p : α → Prop} {a : α} {l : List α} (h : ∀ x ∈ a :: l, p x) :
∀ x ∈ l, p x := (forall_mem_cons.1 h).2
#align list.forall_mem_of_forall_mem_cons List.forall_mem_of_forall_mem_cons
#align list.forall_mem_singleton List.forall_mem_singleton
#align list.forall_mem_append List.forall_mem_append
#align list.not_exists_mem_nil List.not_exists_mem_nilₓ -- bExists change
-- Porting note: bExists in Lean3 and And in Lean4
theorem exists_mem_cons_of {p : α → Prop} {a : α} (l : List α) (h : p a) : ∃ x ∈ a :: l, p x :=
⟨a, mem_cons_self _ _, h⟩
#align list.exists_mem_cons_of List.exists_mem_cons_ofₓ -- bExists change
-- Porting note: bExists in Lean3 and And in Lean4
theorem exists_mem_cons_of_exists {p : α → Prop} {a : α} {l : List α} : (∃ x ∈ l, p x) →
∃ x ∈ a :: l, p x :=
fun ⟨x, xl, px⟩ => ⟨x, mem_cons_of_mem _ xl, px⟩
#align list.exists_mem_cons_of_exists List.exists_mem_cons_of_existsₓ -- bExists change
-- Porting note: bExists in Lean3 and And in Lean4
theorem or_exists_of_exists_mem_cons {p : α → Prop} {a : α} {l : List α} : (∃ x ∈ a :: l, p x) →
p a ∨ ∃ x ∈ l, p x :=
fun ⟨x, xal, px⟩ =>
Or.elim (eq_or_mem_of_mem_cons xal) (fun h : x = a => by rw [← h]; left; exact px)
fun h : x ∈ l => Or.inr ⟨x, h, px⟩
#align list.or_exists_of_exists_mem_cons List.or_exists_of_exists_mem_consₓ -- bExists change
theorem exists_mem_cons_iff (p : α → Prop) (a : α) (l : List α) :
(∃ x ∈ a :: l, p x) ↔ p a ∨ ∃ x ∈ l, p x :=
Iff.intro or_exists_of_exists_mem_cons fun h =>
Or.elim h (exists_mem_cons_of l) exists_mem_cons_of_exists
#align list.exists_mem_cons_iff List.exists_mem_cons_iff
instance : IsTrans (List α) Subset where
trans := fun _ _ _ => List.Subset.trans
#align list.subset_def List.subset_def
#align list.subset_append_of_subset_left List.subset_append_of_subset_left
#align list.subset_append_of_subset_right List.subset_append_of_subset_right
#align list.cons_subset List.cons_subset
theorem cons_subset_of_subset_of_mem {a : α} {l m : List α}
(ainm : a ∈ m) (lsubm : l ⊆ m) : a::l ⊆ m :=
cons_subset.2 ⟨ainm, lsubm⟩
#align list.cons_subset_of_subset_of_mem List.cons_subset_of_subset_of_mem
theorem append_subset_of_subset_of_subset {l₁ l₂ l : List α} (l₁subl : l₁ ⊆ l) (l₂subl : l₂ ⊆ l) :
l₁ ++ l₂ ⊆ l :=
fun _ h ↦ (mem_append.1 h).elim (@l₁subl _) (@l₂subl _)
#align list.append_subset_of_subset_of_subset List.append_subset_of_subset_of_subset
-- Porting note: in Batteries
#align list.append_subset_iff List.append_subset
alias ⟨eq_nil_of_subset_nil, _⟩ := subset_nil
#align list.eq_nil_of_subset_nil List.eq_nil_of_subset_nil
#align list.eq_nil_iff_forall_not_mem List.eq_nil_iff_forall_not_mem
#align list.map_subset List.map_subset
theorem map_subset_iff {l₁ l₂ : List α} (f : α → β) (h : Injective f) :
map f l₁ ⊆ map f l₂ ↔ l₁ ⊆ l₂ := by
refine ⟨?_, map_subset f⟩; intro h2 x hx
rcases mem_map.1 (h2 (mem_map_of_mem f hx)) with ⟨x', hx', hxx'⟩
cases h hxx'; exact hx'
#align list.map_subset_iff List.map_subset_iff
theorem append_eq_has_append {L₁ L₂ : List α} : List.append L₁ L₂ = L₁ ++ L₂ :=
rfl
#align list.append_eq_has_append List.append_eq_has_append
#align list.singleton_append List.singleton_append
#align list.append_ne_nil_of_ne_nil_left List.append_ne_nil_of_ne_nil_left
#align list.append_ne_nil_of_ne_nil_right List.append_ne_nil_of_ne_nil_right
#align list.append_eq_nil List.append_eq_nil
-- Porting note: in Batteries
#align list.nil_eq_append_iff List.nil_eq_append
@[deprecated (since := "2024-03-24")] alias append_eq_cons_iff := append_eq_cons
#align list.append_eq_cons_iff List.append_eq_cons
@[deprecated (since := "2024-03-24")] alias cons_eq_append_iff := cons_eq_append
#align list.cons_eq_append_iff List.cons_eq_append
#align list.append_eq_append_iff List.append_eq_append_iff
#align list.take_append_drop List.take_append_drop
#align list.append_inj List.append_inj
#align list.append_inj_right List.append_inj_rightₓ -- implicits order
#align list.append_inj_left List.append_inj_leftₓ -- implicits order
#align list.append_inj' List.append_inj'ₓ -- implicits order
#align list.append_inj_right' List.append_inj_right'ₓ -- implicits order
#align list.append_inj_left' List.append_inj_left'ₓ -- implicits order
@[deprecated (since := "2024-01-18")] alias append_left_cancel := append_cancel_left
#align list.append_left_cancel List.append_cancel_left
@[deprecated (since := "2024-01-18")] alias append_right_cancel := append_cancel_right
#align list.append_right_cancel List.append_cancel_right
@[simp] theorem append_left_eq_self {x y : List α} : x ++ y = y ↔ x = [] := by
rw [← append_left_inj (s₁ := x), nil_append]
@[simp] theorem self_eq_append_left {x y : List α} : y = x ++ y ↔ x = [] := by
rw [eq_comm, append_left_eq_self]
@[simp] theorem append_right_eq_self {x y : List α} : x ++ y = x ↔ y = [] := by
rw [← append_right_inj (t₁ := y), append_nil]
@[simp] theorem self_eq_append_right {x y : List α} : x = x ++ y ↔ y = [] := by
rw [eq_comm, append_right_eq_self]
theorem append_right_injective (s : List α) : Injective fun t ↦ s ++ t :=
fun _ _ ↦ append_cancel_left
#align list.append_right_injective List.append_right_injective
#align list.append_right_inj List.append_right_inj
theorem append_left_injective (t : List α) : Injective fun s ↦ s ++ t :=
fun _ _ ↦ append_cancel_right
#align list.append_left_injective List.append_left_injective
#align list.append_left_inj List.append_left_inj
#align list.map_eq_append_split List.map_eq_append_split
@[simp] lemma replicate_zero (a : α) : replicate 0 a = [] := rfl
#align list.replicate_zero List.replicate_zero
attribute [simp] replicate_succ
#align list.replicate_succ List.replicate_succ
lemma replicate_one (a : α) : replicate 1 a = [a] := rfl
#align list.replicate_one List.replicate_one
#align list.length_replicate List.length_replicate
#align list.mem_replicate List.mem_replicate
#align list.eq_of_mem_replicate List.eq_of_mem_replicate
theorem eq_replicate_length {a : α} : ∀ {l : List α}, l = replicate l.length a ↔ ∀ b ∈ l, b = a
| [] => by simp
| (b :: l) => by simp [eq_replicate_length]
#align list.eq_replicate_length List.eq_replicate_length
#align list.eq_replicate_of_mem List.eq_replicate_of_mem
#align list.eq_replicate List.eq_replicate
theorem replicate_add (m n) (a : α) : replicate (m + n) a = replicate m a ++ replicate n a := by
induction m <;> simp [*, succ_add, replicate]
#align list.replicate_add List.replicate_add
theorem replicate_succ' (n) (a : α) : replicate (n + 1) a = replicate n a ++ [a] :=
replicate_add n 1 a
#align list.replicate_succ' List.replicate_succ'
theorem replicate_subset_singleton (n) (a : α) : replicate n a ⊆ [a] := fun _ h =>
mem_singleton.2 (eq_of_mem_replicate h)
#align list.replicate_subset_singleton List.replicate_subset_singleton
theorem subset_singleton_iff {a : α} {L : List α} : L ⊆ [a] ↔ ∃ n, L = replicate n a := by
simp only [eq_replicate, subset_def, mem_singleton, exists_eq_left']
#align list.subset_singleton_iff List.subset_singleton_iff
@[simp] theorem map_replicate (f : α → β) (n) (a : α) :
map f (replicate n a) = replicate n (f a) := by
induction n <;> [rfl; simp only [*, replicate, map]]
#align list.map_replicate List.map_replicate
@[simp] theorem tail_replicate (a : α) (n) :
tail (replicate n a) = replicate (n - 1) a := by cases n <;> rfl
#align list.tail_replicate List.tail_replicate
@[simp] theorem join_replicate_nil (n : ℕ) : join (replicate n []) = @nil α := by
induction n <;> [rfl; simp only [*, replicate, join, append_nil]]
#align list.join_replicate_nil List.join_replicate_nil
theorem replicate_right_injective {n : ℕ} (hn : n ≠ 0) : Injective (@replicate α n) :=
fun _ _ h => (eq_replicate.1 h).2 _ <| mem_replicate.2 ⟨hn, rfl⟩
#align list.replicate_right_injective List.replicate_right_injective
theorem replicate_right_inj {a b : α} {n : ℕ} (hn : n ≠ 0) :
replicate n a = replicate n b ↔ a = b :=
(replicate_right_injective hn).eq_iff
#align list.replicate_right_inj List.replicate_right_inj
@[simp] theorem replicate_right_inj' {a b : α} : ∀ {n},
replicate n a = replicate n b ↔ n = 0 ∨ a = b
| 0 => by simp
| n + 1 => (replicate_right_inj n.succ_ne_zero).trans <| by simp only [n.succ_ne_zero, false_or]
#align list.replicate_right_inj' List.replicate_right_inj'
theorem replicate_left_injective (a : α) : Injective (replicate · a) :=
LeftInverse.injective (length_replicate · a)
#align list.replicate_left_injective List.replicate_left_injective
@[simp] theorem replicate_left_inj {a : α} {n m : ℕ} : replicate n a = replicate m a ↔ n = m :=
(replicate_left_injective a).eq_iff
#align list.replicate_left_inj List.replicate_left_inj
@[simp] theorem head_replicate (n : ℕ) (a : α) (h) : head (replicate n a) h = a := by
cases n <;> simp at h ⊢
theorem mem_pure (x y : α) : x ∈ (pure y : List α) ↔ x = y := by simp
#align list.mem_pure List.mem_pure
@[simp]
theorem bind_eq_bind {α β} (f : α → List β) (l : List α) : l >>= f = l.bind f :=
rfl
#align list.bind_eq_bind List.bind_eq_bind
#align list.bind_append List.append_bind
#align list.concat_nil List.concat_nil
#align list.concat_cons List.concat_cons
#align list.concat_eq_append List.concat_eq_append
#align list.init_eq_of_concat_eq List.init_eq_of_concat_eq
#align list.last_eq_of_concat_eq List.last_eq_of_concat_eq
#align list.concat_ne_nil List.concat_ne_nil
#align list.concat_append List.concat_append
#align list.length_concat List.length_concat
#align list.append_concat List.append_concat
#align list.reverse_nil List.reverse_nil
#align list.reverse_core List.reverseAux
-- Porting note: Do we need this?
attribute [local simp] reverseAux
#align list.reverse_cons List.reverse_cons
#align list.reverse_core_eq List.reverseAux_eq
theorem reverse_cons' (a : α) (l : List α) : reverse (a :: l) = concat (reverse l) a := by
simp only [reverse_cons, concat_eq_append]
#align list.reverse_cons' List.reverse_cons'
theorem reverse_concat' (l : List α) (a : α) : (l ++ [a]).reverse = a :: l.reverse := by
rw [reverse_append]; rfl
-- Porting note (#10618): simp can prove this
-- @[simp]
theorem reverse_singleton (a : α) : reverse [a] = [a] :=
rfl
#align list.reverse_singleton List.reverse_singleton
#align list.reverse_append List.reverse_append
#align list.reverse_concat List.reverse_concat
#align list.reverse_reverse List.reverse_reverse
@[simp]
theorem reverse_involutive : Involutive (@reverse α) :=
reverse_reverse
#align list.reverse_involutive List.reverse_involutive
@[simp]
theorem reverse_injective : Injective (@reverse α) :=
reverse_involutive.injective
#align list.reverse_injective List.reverse_injective
theorem reverse_surjective : Surjective (@reverse α) :=
reverse_involutive.surjective
#align list.reverse_surjective List.reverse_surjective
theorem reverse_bijective : Bijective (@reverse α) :=
reverse_involutive.bijective
#align list.reverse_bijective List.reverse_bijective
@[simp]
theorem reverse_inj {l₁ l₂ : List α} : reverse l₁ = reverse l₂ ↔ l₁ = l₂ :=
reverse_injective.eq_iff
#align list.reverse_inj List.reverse_inj
theorem reverse_eq_iff {l l' : List α} : l.reverse = l' ↔ l = l'.reverse :=
reverse_involutive.eq_iff
#align list.reverse_eq_iff List.reverse_eq_iff
#align list.reverse_eq_nil List.reverse_eq_nil_iff
theorem concat_eq_reverse_cons (a : α) (l : List α) : concat l a = reverse (a :: reverse l) := by
simp only [concat_eq_append, reverse_cons, reverse_reverse]
#align list.concat_eq_reverse_cons List.concat_eq_reverse_cons
#align list.length_reverse List.length_reverse
-- Porting note: This one was @[simp] in mathlib 3,
-- but Lean contains a competing simp lemma reverse_map.
-- For now we remove @[simp] to avoid simplification loops.
-- TODO: Change Lean lemma to match mathlib 3?
theorem map_reverse (f : α → β) (l : List α) : map f (reverse l) = reverse (map f l) :=
(reverse_map f l).symm
#align list.map_reverse List.map_reverse
theorem map_reverseAux (f : α → β) (l₁ l₂ : List α) :
map f (reverseAux l₁ l₂) = reverseAux (map f l₁) (map f l₂) := by
simp only [reverseAux_eq, map_append, map_reverse]
#align list.map_reverse_core List.map_reverseAux
#align list.mem_reverse List.mem_reverse
@[simp] theorem reverse_replicate (n) (a : α) : reverse (replicate n a) = replicate n a :=
eq_replicate.2
⟨by rw [length_reverse, length_replicate],
fun b h => eq_of_mem_replicate (mem_reverse.1 h)⟩
#align list.reverse_replicate List.reverse_replicate
-- Porting note: this does not work as desired
-- attribute [simp] List.isEmpty
theorem isEmpty_iff_eq_nil {l : List α} : l.isEmpty ↔ l = [] := by cases l <;> simp [isEmpty]
#align list.empty_iff_eq_nil List.isEmpty_iff_eq_nil
#align list.length_init List.length_dropLast
@[simp]
theorem getLast_cons {a : α} {l : List α} :
∀ h : l ≠ nil, getLast (a :: l) (cons_ne_nil a l) = getLast l h := by
induction l <;> intros
· contradiction
· rfl
#align list.last_cons List.getLast_cons
theorem getLast_append_singleton {a : α} (l : List α) :
getLast (l ++ [a]) (append_ne_nil_of_ne_nil_right l _ (cons_ne_nil a _)) = a := by
simp only [getLast_append]
#align list.last_append_singleton List.getLast_append_singleton
-- Porting note: name should be fixed upstream
theorem getLast_append' (l₁ l₂ : List α) (h : l₂ ≠ []) :
getLast (l₁ ++ l₂) (append_ne_nil_of_ne_nil_right l₁ l₂ h) = getLast l₂ h := by
induction' l₁ with _ _ ih
· simp
· simp only [cons_append]
rw [List.getLast_cons]
exact ih
#align list.last_append List.getLast_append'
theorem getLast_concat' {a : α} (l : List α) : getLast (concat l a) (concat_ne_nil a l) = a :=
getLast_concat ..
#align list.last_concat List.getLast_concat'
@[simp]
theorem getLast_singleton' (a : α) : getLast [a] (cons_ne_nil a []) = a := rfl
#align list.last_singleton List.getLast_singleton'
-- Porting note (#10618): simp can prove this
-- @[simp]
theorem getLast_cons_cons (a₁ a₂ : α) (l : List α) :
getLast (a₁ :: a₂ :: l) (cons_ne_nil _ _) = getLast (a₂ :: l) (cons_ne_nil a₂ l) :=
rfl
#align list.last_cons_cons List.getLast_cons_cons
theorem dropLast_append_getLast : ∀ {l : List α} (h : l ≠ []), dropLast l ++ [getLast l h] = l
| [], h => absurd rfl h
| [a], h => rfl
| a :: b :: l, h => by
rw [dropLast_cons₂, cons_append, getLast_cons (cons_ne_nil _ _)]
congr
exact dropLast_append_getLast (cons_ne_nil b l)
#align list.init_append_last List.dropLast_append_getLast
theorem getLast_congr {l₁ l₂ : List α} (h₁ : l₁ ≠ []) (h₂ : l₂ ≠ []) (h₃ : l₁ = l₂) :
getLast l₁ h₁ = getLast l₂ h₂ := by subst l₁; rfl
#align list.last_congr List.getLast_congr
#align list.last_mem List.getLast_mem
theorem getLast_replicate_succ (m : ℕ) (a : α) :
(replicate (m + 1) a).getLast (ne_nil_of_length_eq_succ (length_replicate _ _)) = a := by
simp only [replicate_succ']
exact getLast_append_singleton _
#align list.last_replicate_succ List.getLast_replicate_succ
-- Porting note: Moved earlier in file, for use in subsequent lemmas.
@[simp]
theorem getLast?_cons_cons (a b : α) (l : List α) :
getLast? (a :: b :: l) = getLast? (b :: l) := rfl
@[simp]
theorem getLast?_isNone : ∀ {l : List α}, (getLast? l).isNone ↔ l = []
| [] => by simp
| [a] => by simp
| a :: b :: l => by simp [@getLast?_isNone (b :: l)]
#align list.last'_is_none List.getLast?_isNone
@[simp]
theorem getLast?_isSome : ∀ {l : List α}, l.getLast?.isSome ↔ l ≠ []
| [] => by simp
| [a] => by simp
| a :: b :: l => by simp [@getLast?_isSome (b :: l)]
#align list.last'_is_some List.getLast?_isSome
theorem mem_getLast?_eq_getLast : ∀ {l : List α} {x : α}, x ∈ l.getLast? → ∃ h, x = getLast l h
| [], x, hx => False.elim <| by simp at hx
| [a], x, hx =>
have : a = x := by simpa using hx
this ▸ ⟨cons_ne_nil a [], rfl⟩
| a :: b :: l, x, hx => by
rw [getLast?_cons_cons] at hx
rcases mem_getLast?_eq_getLast hx with ⟨_, h₂⟩
use cons_ne_nil _ _
assumption
#align list.mem_last'_eq_last List.mem_getLast?_eq_getLast
theorem getLast?_eq_getLast_of_ne_nil : ∀ {l : List α} (h : l ≠ []), l.getLast? = some (l.getLast h)
| [], h => (h rfl).elim
| [_], _ => rfl
| _ :: b :: l, _ => @getLast?_eq_getLast_of_ne_nil (b :: l) (cons_ne_nil _ _)
#align list.last'_eq_last_of_ne_nil List.getLast?_eq_getLast_of_ne_nil
theorem mem_getLast?_cons {x y : α} : ∀ {l : List α}, x ∈ l.getLast? → x ∈ (y :: l).getLast?
| [], _ => by contradiction
| _ :: _, h => h
#align list.mem_last'_cons List.mem_getLast?_cons
theorem mem_of_mem_getLast? {l : List α} {a : α} (ha : a ∈ l.getLast?) : a ∈ l :=
let ⟨_, h₂⟩ := mem_getLast?_eq_getLast ha
h₂.symm ▸ getLast_mem _
#align list.mem_of_mem_last' List.mem_of_mem_getLast?
theorem dropLast_append_getLast? : ∀ {l : List α}, ∀ a ∈ l.getLast?, dropLast l ++ [a] = l
| [], a, ha => (Option.not_mem_none a ha).elim
| [a], _, rfl => rfl
| a :: b :: l, c, hc => by
rw [getLast?_cons_cons] at hc
rw [dropLast_cons₂, cons_append, dropLast_append_getLast? _ hc]
#align list.init_append_last' List.dropLast_append_getLast?
theorem getLastI_eq_getLast? [Inhabited α] : ∀ l : List α, l.getLastI = l.getLast?.iget
| [] => by simp [getLastI, Inhabited.default]
| [a] => rfl
| [a, b] => rfl
| [a, b, c] => rfl
| _ :: _ :: c :: l => by simp [getLastI, getLastI_eq_getLast? (c :: l)]
#align list.ilast_eq_last' List.getLastI_eq_getLast?
@[simp]
theorem getLast?_append_cons :
∀ (l₁ : List α) (a : α) (l₂ : List α), getLast? (l₁ ++ a :: l₂) = getLast? (a :: l₂)
| [], a, l₂ => rfl
| [b], a, l₂ => rfl
| b :: c :: l₁, a, l₂ => by rw [cons_append, cons_append, getLast?_cons_cons,
← cons_append, getLast?_append_cons (c :: l₁)]
#align list.last'_append_cons List.getLast?_append_cons
#align list.last'_cons_cons List.getLast?_cons_cons
theorem getLast?_append_of_ne_nil (l₁ : List α) :
∀ {l₂ : List α} (_ : l₂ ≠ []), getLast? (l₁ ++ l₂) = getLast? l₂
| [], hl₂ => by contradiction
| b :: l₂, _ => getLast?_append_cons l₁ b l₂
#align list.last'_append_of_ne_nil List.getLast?_append_of_ne_nil
theorem getLast?_append {l₁ l₂ : List α} {x : α} (h : x ∈ l₂.getLast?) :
x ∈ (l₁ ++ l₂).getLast? := by
cases l₂
· contradiction
· rw [List.getLast?_append_cons]
exact h
#align list.last'_append List.getLast?_append
@[simp]
theorem head!_nil [Inhabited α] : ([] : List α).head! = default := rfl
@[simp] theorem head_cons_tail (x : List α) (h : x ≠ []) : x.head h :: x.tail = x := by
cases x <;> simp at h ⊢
theorem head!_eq_head? [Inhabited α] (l : List α) : head! l = (head? l).iget := by cases l <;> rfl
#align list.head_eq_head' List.head!_eq_head?
theorem surjective_head! [Inhabited α] : Surjective (@head! α _) := fun x => ⟨[x], rfl⟩
#align list.surjective_head List.surjective_head!
theorem surjective_head? : Surjective (@head? α) :=
Option.forall.2 ⟨⟨[], rfl⟩, fun x => ⟨[x], rfl⟩⟩
#align list.surjective_head' List.surjective_head?
theorem surjective_tail : Surjective (@tail α)
| [] => ⟨[], rfl⟩
| a :: l => ⟨a :: a :: l, rfl⟩
#align list.surjective_tail List.surjective_tail
theorem eq_cons_of_mem_head? {x : α} : ∀ {l : List α}, x ∈ l.head? → l = x :: tail l
| [], h => (Option.not_mem_none _ h).elim
| a :: l, h => by
simp only [head?, Option.mem_def, Option.some_inj] at h
exact h ▸ rfl
#align list.eq_cons_of_mem_head' List.eq_cons_of_mem_head?
theorem mem_of_mem_head? {x : α} {l : List α} (h : x ∈ l.head?) : x ∈ l :=
(eq_cons_of_mem_head? h).symm ▸ mem_cons_self _ _
#align list.mem_of_mem_head' List.mem_of_mem_head?
@[simp] theorem head!_cons [Inhabited α] (a : α) (l : List α) : head! (a :: l) = a := rfl
#align list.head_cons List.head!_cons
#align list.tail_nil List.tail_nil
#align list.tail_cons List.tail_cons
@[simp]
theorem head!_append [Inhabited α] (t : List α) {s : List α} (h : s ≠ []) :
head! (s ++ t) = head! s := by
induction s
· contradiction
· rfl
#align list.head_append List.head!_append
theorem head?_append {s t : List α} {x : α} (h : x ∈ s.head?) : x ∈ (s ++ t).head? := by
cases s
· contradiction
· exact h
#align list.head'_append List.head?_append
theorem head?_append_of_ne_nil :
∀ (l₁ : List α) {l₂ : List α} (_ : l₁ ≠ []), head? (l₁ ++ l₂) = head? l₁
| _ :: _, _, _ => rfl
#align list.head'_append_of_ne_nil List.head?_append_of_ne_nil
theorem tail_append_singleton_of_ne_nil {a : α} {l : List α} (h : l ≠ nil) :
tail (l ++ [a]) = tail l ++ [a] := by
induction l
· contradiction
· rw [tail, cons_append, tail]
#align list.tail_append_singleton_of_ne_nil List.tail_append_singleton_of_ne_nil
theorem cons_head?_tail : ∀ {l : List α} {a : α}, a ∈ head? l → a :: tail l = l
| [], a, h => by contradiction
| b :: l, a, h => by
simp? at h says simp only [head?_cons, Option.mem_def, Option.some.injEq] at h
simp [h]
#align list.cons_head'_tail List.cons_head?_tail
theorem head!_mem_head? [Inhabited α] : ∀ {l : List α}, l ≠ [] → head! l ∈ head? l
| [], h => by contradiction
| a :: l, _ => rfl
#align list.head_mem_head' List.head!_mem_head?
theorem cons_head!_tail [Inhabited α] {l : List α} (h : l ≠ []) : head! l :: tail l = l :=
cons_head?_tail (head!_mem_head? h)
#align list.cons_head_tail List.cons_head!_tail
theorem head!_mem_self [Inhabited α] {l : List α} (h : l ≠ nil) : l.head! ∈ l := by
have h' := mem_cons_self l.head! l.tail
rwa [cons_head!_tail h] at h'
#align list.head_mem_self List.head!_mem_self
theorem head_mem {l : List α} : ∀ (h : l ≠ nil), l.head h ∈ l := by
cases l <;> simp
@[simp]
theorem head?_map (f : α → β) (l) : head? (map f l) = (head? l).map f := by cases l <;> rfl
#align list.head'_map List.head?_map
theorem tail_append_of_ne_nil (l l' : List α) (h : l ≠ []) : (l ++ l').tail = l.tail ++ l' := by
cases l
· contradiction
· simp
#align list.tail_append_of_ne_nil List.tail_append_of_ne_nil
#align list.nth_le_eq_iff List.get_eq_iff
theorem get_eq_get? (l : List α) (i : Fin l.length) :
l.get i = (l.get? i).get (by simp [get?_eq_get]) := by
simp [get_eq_iff]
#align list.some_nth_le_eq List.get?_eq_get
-- Porting note: List.modifyHead has @[simp], and Lean 4 treats this as
-- an invitation to unfold modifyHead in any context,
-- not just use the equational lemmas.
-- @[simp]
@[simp 1100, nolint simpNF]
theorem modifyHead_modifyHead (l : List α) (f g : α → α) :
(l.modifyHead f).modifyHead g = l.modifyHead (g ∘ f) := by cases l <;> simp
#align list.modify_head_modify_head List.modifyHead_modifyHead
@[elab_as_elim]
def reverseRecOn {motive : List α → Sort*} (l : List α) (nil : motive [])
(append_singleton : ∀ (l : List α) (a : α), motive l → motive (l ++ [a])) : motive l :=
match h : reverse l with
| [] => cast (congr_arg motive <| by simpa using congr(reverse $h.symm)) <|
nil
| head :: tail =>
cast (congr_arg motive <| by simpa using congr(reverse $h.symm)) <|
append_singleton _ head <| reverseRecOn (reverse tail) nil append_singleton
termination_by l.length
decreasing_by
simp_wf
rw [← length_reverse l, h, length_cons]
simp [Nat.lt_succ]
#align list.reverse_rec_on List.reverseRecOn
@[simp]
theorem reverseRecOn_nil {motive : List α → Sort*} (nil : motive [])
(append_singleton : ∀ (l : List α) (a : α), motive l → motive (l ++ [a])) :
reverseRecOn [] nil append_singleton = nil := reverseRecOn.eq_1 ..
-- `unusedHavesSuffices` is getting confused by the unfolding of `reverseRecOn`
@[simp, nolint unusedHavesSuffices]
theorem reverseRecOn_concat {motive : List α → Sort*} (x : α) (xs : List α) (nil : motive [])
(append_singleton : ∀ (l : List α) (a : α), motive l → motive (l ++ [a])) :
reverseRecOn (motive := motive) (xs ++ [x]) nil append_singleton =
append_singleton _ _ (reverseRecOn (motive := motive) xs nil append_singleton) := by
suffices ∀ ys (h : reverse (reverse xs) = ys),
reverseRecOn (motive := motive) (xs ++ [x]) nil append_singleton =
cast (by simp [(reverse_reverse _).symm.trans h])
(append_singleton _ x (reverseRecOn (motive := motive) ys nil append_singleton)) by
exact this _ (reverse_reverse xs)
intros ys hy
conv_lhs => unfold reverseRecOn
split
next h => simp at h
next heq =>
revert heq
simp only [reverse_append, reverse_cons, reverse_nil, nil_append, singleton_append, cons.injEq]
rintro ⟨rfl, rfl⟩
subst ys
rfl
@[elab_as_elim]
def bidirectionalRec {motive : List α → Sort*} (nil : motive []) (singleton : ∀ a : α, motive [a])
(cons_append : ∀ (a : α) (l : List α) (b : α), motive l → motive (a :: (l ++ [b]))) :
∀ l, motive l
| [] => nil
| [a] => singleton a
| a :: b :: l =>
let l' := dropLast (b :: l)
let b' := getLast (b :: l) (cons_ne_nil _ _)
cast (by rw [← dropLast_append_getLast (cons_ne_nil b l)]) <|
cons_append a l' b' (bidirectionalRec nil singleton cons_append l')
termination_by l => l.length
#align list.bidirectional_rec List.bidirectionalRecₓ -- universe order
@[simp]
theorem bidirectionalRec_nil {motive : List α → Sort*}
(nil : motive []) (singleton : ∀ a : α, motive [a])
(cons_append : ∀ (a : α) (l : List α) (b : α), motive l → motive (a :: (l ++ [b]))) :
bidirectionalRec nil singleton cons_append [] = nil := bidirectionalRec.eq_1 ..
@[simp]
theorem bidirectionalRec_singleton {motive : List α → Sort*}
(nil : motive []) (singleton : ∀ a : α, motive [a])
(cons_append : ∀ (a : α) (l : List α) (b : α), motive l → motive (a :: (l ++ [b]))) (a : α):
bidirectionalRec nil singleton cons_append [a] = singleton a := by
simp [bidirectionalRec]
@[simp]
theorem bidirectionalRec_cons_append {motive : List α → Sort*}
(nil : motive []) (singleton : ∀ a : α, motive [a])
(cons_append : ∀ (a : α) (l : List α) (b : α), motive l → motive (a :: (l ++ [b])))
(a : α) (l : List α) (b : α) :
bidirectionalRec nil singleton cons_append (a :: (l ++ [b])) =
cons_append a l b (bidirectionalRec nil singleton cons_append l) := by
conv_lhs => unfold bidirectionalRec
cases l with
| nil => rfl
| cons x xs =>
simp only [List.cons_append]
dsimp only [← List.cons_append]
suffices ∀ (ys init : List α) (hinit : init = ys) (last : α) (hlast : last = b),
(cons_append a init last
(bidirectionalRec nil singleton cons_append init)) =
cast (congr_arg motive <| by simp [hinit, hlast])
(cons_append a ys b (bidirectionalRec nil singleton cons_append ys)) by
rw [this (x :: xs) _ (by rw [dropLast_append_cons, dropLast_single, append_nil]) _ (by simp)]
simp
rintro ys init rfl last rfl
rfl
@[elab_as_elim]
abbrev bidirectionalRecOn {C : List α → Sort*} (l : List α) (H0 : C []) (H1 : ∀ a : α, C [a])
(Hn : ∀ (a : α) (l : List α) (b : α), C l → C (a :: (l ++ [b]))) : C l :=
bidirectionalRec H0 H1 Hn l
#align list.bidirectional_rec_on List.bidirectionalRecOn
attribute [refl] List.Sublist.refl
#align list.nil_sublist List.nil_sublist
#align list.sublist.refl List.Sublist.refl
#align list.sublist.trans List.Sublist.trans
#align list.sublist_cons List.sublist_cons
#align list.sublist_of_cons_sublist List.sublist_of_cons_sublist
theorem Sublist.cons_cons {l₁ l₂ : List α} (a : α) (s : l₁ <+ l₂) : a :: l₁ <+ a :: l₂ :=
Sublist.cons₂ _ s
#align list.sublist.cons_cons List.Sublist.cons_cons
#align list.sublist_append_left List.sublist_append_left
#align list.sublist_append_right List.sublist_append_right
theorem sublist_cons_of_sublist (a : α) (h : l₁ <+ l₂) : l₁ <+ a :: l₂ := h.cons _
#align list.sublist_cons_of_sublist List.sublist_cons_of_sublist
#align list.sublist_append_of_sublist_left List.sublist_append_of_sublist_left
#align list.sublist_append_of_sublist_right List.sublist_append_of_sublist_right
theorem tail_sublist : ∀ l : List α, tail l <+ l
| [] => .slnil
| a::l => sublist_cons a l
#align list.tail_sublist List.tail_sublist
@[gcongr] protected theorem Sublist.tail : ∀ {l₁ l₂ : List α}, l₁ <+ l₂ → tail l₁ <+ tail l₂
| _, _, slnil => .slnil
| _, _, Sublist.cons _ h => (tail_sublist _).trans h
| _, _, Sublist.cons₂ _ h => h
theorem Sublist.of_cons_cons {l₁ l₂ : List α} {a b : α} (h : a :: l₁ <+ b :: l₂) : l₁ <+ l₂ :=
h.tail
#align list.sublist_of_cons_sublist_cons List.Sublist.of_cons_cons
@[deprecated (since := "2024-04-07")]
theorem sublist_of_cons_sublist_cons {a} (h : a :: l₁ <+ a :: l₂) : l₁ <+ l₂ := h.of_cons_cons
attribute [simp] cons_sublist_cons
@[deprecated (since := "2024-04-07")] alias cons_sublist_cons_iff := cons_sublist_cons
#align list.cons_sublist_cons_iff List.cons_sublist_cons_iff
#align list.append_sublist_append_left List.append_sublist_append_left
#align list.sublist.append_right List.Sublist.append_right
#align list.sublist_or_mem_of_sublist List.sublist_or_mem_of_sublist
#align list.sublist.reverse List.Sublist.reverse
#align list.reverse_sublist_iff List.reverse_sublist
#align list.append_sublist_append_right List.append_sublist_append_right
#align list.sublist.append List.Sublist.append
#align list.sublist.subset List.Sublist.subset
#align list.singleton_sublist List.singleton_sublist
theorem eq_nil_of_sublist_nil {l : List α} (s : l <+ []) : l = [] :=
eq_nil_of_subset_nil <| s.subset
#align list.eq_nil_of_sublist_nil List.eq_nil_of_sublist_nil
-- Porting note: this lemma seems to have been renamed on the occasion of its move to Batteries
alias sublist_nil_iff_eq_nil := sublist_nil
#align list.sublist_nil_iff_eq_nil List.sublist_nil_iff_eq_nil
@[simp] lemma sublist_singleton {l : List α} {a : α} : l <+ [a] ↔ l = [] ∨ l = [a] := by
constructor <;> rintro (_ | _) <;> aesop
#align list.replicate_sublist_replicate List.replicate_sublist_replicate
theorem sublist_replicate_iff {l : List α} {a : α} {n : ℕ} :
l <+ replicate n a ↔ ∃ k ≤ n, l = replicate k a :=
⟨fun h =>
⟨l.length, h.length_le.trans_eq (length_replicate _ _),
eq_replicate_length.mpr fun b hb => eq_of_mem_replicate (h.subset hb)⟩,
by rintro ⟨k, h, rfl⟩; exact (replicate_sublist_replicate _).mpr h⟩
#align list.sublist_replicate_iff List.sublist_replicate_iff
#align list.sublist.eq_of_length List.Sublist.eq_of_length
#align list.sublist.eq_of_length_le List.Sublist.eq_of_length_le
theorem Sublist.antisymm (s₁ : l₁ <+ l₂) (s₂ : l₂ <+ l₁) : l₁ = l₂ :=
s₁.eq_of_length_le s₂.length_le
#align list.sublist.antisymm List.Sublist.antisymm
instance decidableSublist [DecidableEq α] : ∀ l₁ l₂ : List α, Decidable (l₁ <+ l₂)
| [], _ => isTrue <| nil_sublist _
| _ :: _, [] => isFalse fun h => List.noConfusion <| eq_nil_of_sublist_nil h
| a :: l₁, b :: l₂ =>
if h : a = b then
@decidable_of_decidable_of_iff _ _ (decidableSublist l₁ l₂) <| h ▸ cons_sublist_cons.symm
else
@decidable_of_decidable_of_iff _ _ (decidableSublist (a :: l₁) l₂)
⟨sublist_cons_of_sublist _, fun s =>
match a, l₁, s, h with
| _, _, Sublist.cons _ s', h => s'
| _, _, Sublist.cons₂ t _, h => absurd rfl h⟩
#align list.decidable_sublist List.decidableSublist
section IndexOf
variable [DecidableEq α]
#align list.index_of_nil List.indexOf_nil
-- indexOf_cons_eq _ rfl
@[simp]
theorem indexOf_cons_self (a : α) (l : List α) : indexOf a (a :: l) = 0 := by
rw [indexOf, findIdx_cons, beq_self_eq_true, cond]
#align list.index_of_cons_self List.indexOf_cons_self
-- fun e => if_pos e
theorem indexOf_cons_eq {a b : α} (l : List α) : b = a → indexOf a (b :: l) = 0
| e => by rw [← e]; exact indexOf_cons_self b l
#align list.index_of_cons_eq List.indexOf_cons_eq
-- fun n => if_neg n
@[simp]
theorem indexOf_cons_ne {a b : α} (l : List α) : b ≠ a → indexOf a (b :: l) = succ (indexOf a l)
| h => by simp only [indexOf, findIdx_cons, Bool.cond_eq_ite, beq_iff_eq, h, ite_false]
#align list.index_of_cons_ne List.indexOf_cons_ne
#align list.index_of_cons List.indexOf_cons
theorem indexOf_eq_length {a : α} {l : List α} : indexOf a l = length l ↔ a ∉ l := by
induction' l with b l ih
· exact iff_of_true rfl (not_mem_nil _)
simp only [length, mem_cons, indexOf_cons, eq_comm]
rw [cond_eq_if]
split_ifs with h <;> simp at h
· exact iff_of_false (by rintro ⟨⟩) fun H => H <| Or.inl h.symm
· simp only [Ne.symm h, false_or_iff]
rw [← ih]
exact succ_inj'
#align list.index_of_eq_length List.indexOf_eq_length
@[simp]
theorem indexOf_of_not_mem {l : List α} {a : α} : a ∉ l → indexOf a l = length l :=
indexOf_eq_length.2
#align list.index_of_of_not_mem List.indexOf_of_not_mem
| Mathlib/Data/List/Basic.lean | 1,181 | 1,186 | theorem indexOf_le_length {a : α} {l : List α} : indexOf a l ≤ length l := by |
induction' l with b l ih; · rfl
simp only [length, indexOf_cons, cond_eq_if, beq_iff_eq]
by_cases h : b = a
· rw [if_pos h]; exact Nat.zero_le _
· rw [if_neg h]; exact succ_le_succ ih
|
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