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.CategoryTheory.EffectiveEpi.Preserves
import Mathlib.CategoryTheory.Limits.Final.ParallelPair
import Mathlib.CategoryTheory.Preadditive.Projective
import Mathlib.CategoryTheory.Sites.Canonical
import Mathlib.CategoryTheory.Sites.Coherent.Basic
import Mathlib.CategoryTheory.Sites.EffectiveEpimorphic
namespace CategoryTheory
open Limits
variable {C D E : Type*} [Category C] [Category D] [Category E]
open Opposite Presieve Functor
class Presieve.regular {X : C} (R : Presieve X) : Prop where
single_epi : ∃ (Y : C) (f : Y ⟶ X), R = Presieve.ofArrows (fun (_ : Unit) ↦ Y)
(fun (_ : Unit) ↦ f) ∧ EffectiveEpi f
namespace regularTopology
lemma equalizerCondition_w (P : Cᵒᵖ ⥤ D) {X B : C} {π : X ⟶ B} (c : PullbackCone π π) :
P.map π.op ≫ P.map c.fst.op = P.map π.op ≫ P.map c.snd.op := by
simp only [← Functor.map_comp, ← op_comp, c.condition]
def SingleEqualizerCondition (P : Cᵒᵖ ⥤ D) ⦃X B : C⦄ (π : X ⟶ B) : Prop :=
∀ (c : PullbackCone π π) (_ : IsLimit c),
Nonempty (IsLimit (Fork.ofι (P.map π.op) (equalizerCondition_w P c)))
def EqualizerCondition (P : Cᵒᵖ ⥤ D) : Prop :=
∀ ⦃X B : C⦄ (π : X ⟶ B) [EffectiveEpi π], SingleEqualizerCondition P π
theorem equalizerCondition_of_natIso {P P' : Cᵒᵖ ⥤ D} (i : P ≅ P')
(hP : EqualizerCondition P) : EqualizerCondition P' := fun X B π _ c hc ↦
⟨Fork.isLimitOfIsos _ (hP π c hc).some _ (i.app _) (i.app _) (i.app _)⟩
theorem equalizerCondition_precomp_of_preservesPullback (P : Cᵒᵖ ⥤ D) (F : E ⥤ C)
[∀ {X B} (π : X ⟶ B) [EffectiveEpi π], PreservesLimit (cospan π π) F]
[F.PreservesEffectiveEpis] (hP : EqualizerCondition P) : EqualizerCondition (F.op ⋙ P) := by
intro X B π _ c hc
have h : P.map (F.map π).op = (F.op ⋙ P).map π.op := by simp
refine ⟨(IsLimit.equivIsoLimit (ForkOfι.ext ?_ _ h)) ?_⟩
· simp only [Functor.comp_map, op_map, Quiver.Hom.unop_op, ← map_comp, ← op_comp, c.condition]
· refine (hP (F.map π) (PullbackCone.mk (F.map c.fst) (F.map c.snd) ?_) ?_).some
· simp only [← map_comp, c.condition]
· exact (isLimitMapConePullbackConeEquiv F c.condition)
(isLimitOfPreserves F (hc.ofIsoLimit (PullbackCone.ext (Iso.refl _) (by simp) (by simp))))
def MapToEqualizer (P : Cᵒᵖ ⥤ Type*) {W X B : C} (f : X ⟶ B)
(g₁ g₂ : W ⟶ X) (w : g₁ ≫ f = g₂ ≫ f) :
P.obj (op B) → { x : P.obj (op X) | P.map g₁.op x = P.map g₂.op x } := fun t ↦
⟨P.map f.op t, by simp only [Set.mem_setOf_eq, ← FunctorToTypes.map_comp_apply, ← op_comp, w]⟩
theorem EqualizerCondition.bijective_mapToEqualizer_pullback (P : Cᵒᵖ ⥤ Type*)
(hP : EqualizerCondition P) : ∀ (X B : C) (π : X ⟶ B) [EffectiveEpi π] [HasPullback π π],
Function.Bijective
(MapToEqualizer P π (pullback.fst (f := π) (g := π)) (pullback.snd (f := π) (g := π))
pullback.condition) := by
intro X B π _ _
specialize hP π _ (pullbackIsPullback π π)
rw [Types.type_equalizer_iff_unique] at hP
rw [Function.bijective_iff_existsUnique]
intro ⟨b, hb⟩
obtain ⟨a, ha₁, ha₂⟩ := hP b hb
refine ⟨a, ?_, ?_⟩
· simpa [MapToEqualizer] using ha₁
· simpa [MapToEqualizer] using ha₂
theorem EqualizerCondition.mk (P : Cᵒᵖ ⥤ Type*)
(hP : ∀ (X B : C) (π : X ⟶ B) [EffectiveEpi π] [HasPullback π π], Function.Bijective
(MapToEqualizer P π (pullback.fst (f := π) (g := π)) (pullback.snd (f := π) (g := π))
pullback.condition)) : EqualizerCondition P := by
intro X B π _ c hc
have : HasPullback π π := ⟨c, hc⟩
specialize hP X B π
rw [Types.type_equalizer_iff_unique]
rw [Function.bijective_iff_existsUnique] at hP
intro b hb
have h₁ : ((pullbackIsPullback π π).conePointUniqueUpToIso hc).hom ≫ c.fst =
pullback.fst (f := π) (g := π) := by simp
have hb' : P.map (pullback.fst (f := π) (g := π)).op b = P.map pullback.snd.op b := by
rw [← h₁, op_comp, FunctorToTypes.map_comp_apply, hb]
simp [← FunctorToTypes.map_comp_apply, ← op_comp]
obtain ⟨a, ha₁, ha₂⟩ := hP ⟨b, hb'⟩
refine ⟨a, ?_, ?_⟩
· simpa [MapToEqualizer] using ha₁
· simpa [MapToEqualizer] using ha₂
lemma equalizerCondition_w' (P : Cᵒᵖ ⥤ Type*) {X B : C} (π : X ⟶ B)
[HasPullback π π] : P.map π.op ≫ P.map (pullback.fst (f := π) (g := π)).op =
P.map π.op ≫ P.map (pullback.snd).op := by
simp only [← Functor.map_comp, ← op_comp, pullback.condition]
lemma mapToEqualizer_eq_comp (P : Cᵒᵖ ⥤ Type*) {X B : C} (π : X ⟶ B)
[HasPullback π π] : MapToEqualizer P π pullback.fst pullback.snd pullback.condition =
equalizer.lift (P.map π.op) (equalizerCondition_w' P π) ≫
(Types.equalizerIso _ _).hom := by
rw [← Iso.comp_inv_eq (α := Types.equalizerIso _ _)]
apply equalizer.hom_ext
aesop
| Mathlib/CategoryTheory/Sites/Coherent/RegularSheaves.lean | 136 | 150 | theorem equalizerCondition_iff_isIso_lift (P : Cᵒᵖ ⥤ Type*) : EqualizerCondition P ↔
∀ (X B : C) (π : X ⟶ B) [EffectiveEpi π] [HasPullback π π],
IsIso (equalizer.lift (P.map π.op) (equalizerCondition_w' P π)) := by |
constructor
· intro hP X B π _ _
have h := hP.bijective_mapToEqualizer_pullback _ X B π
rw [← isIso_iff_bijective, mapToEqualizer_eq_comp] at h
exact IsIso.of_isIso_comp_right (equalizer.lift (P.map π.op)
(equalizerCondition_w' P π))
(Types.equalizerIso _ _).hom
· intro hP
apply EqualizerCondition.mk
intro X B π _ _
rw [mapToEqualizer_eq_comp, ← isIso_iff_bijective]
infer_instance
|
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
| Mathlib/Data/Nat/Digits.lean | 357 | 376 | 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))
|
import Mathlib.Order.Interval.Finset.Nat
#align_import data.fin.interval from "leanprover-community/mathlib"@"1d29de43a5ba4662dd33b5cfeecfc2a27a5a8a29"
assert_not_exists MonoidWithZero
open Finset Fin Function
namespace Fin
variable (n : ℕ)
instance instLocallyFiniteOrder : LocallyFiniteOrder (Fin n) :=
OrderIso.locallyFiniteOrder Fin.orderIsoSubtype
instance instLocallyFiniteOrderBot : LocallyFiniteOrderBot (Fin n) :=
OrderIso.locallyFiniteOrderBot Fin.orderIsoSubtype
instance instLocallyFiniteOrderTop : ∀ n, LocallyFiniteOrderTop (Fin n)
| 0 => IsEmpty.toLocallyFiniteOrderTop
| _ + 1 => inferInstance
variable {n} (a b : Fin n)
theorem Icc_eq_finset_subtype : Icc a b = (Icc (a : ℕ) b).fin n :=
rfl
#align fin.Icc_eq_finset_subtype Fin.Icc_eq_finset_subtype
theorem Ico_eq_finset_subtype : Ico a b = (Ico (a : ℕ) b).fin n :=
rfl
#align fin.Ico_eq_finset_subtype Fin.Ico_eq_finset_subtype
theorem Ioc_eq_finset_subtype : Ioc a b = (Ioc (a : ℕ) b).fin n :=
rfl
#align fin.Ioc_eq_finset_subtype Fin.Ioc_eq_finset_subtype
theorem Ioo_eq_finset_subtype : Ioo a b = (Ioo (a : ℕ) b).fin n :=
rfl
#align fin.Ioo_eq_finset_subtype Fin.Ioo_eq_finset_subtype
theorem uIcc_eq_finset_subtype : uIcc a b = (uIcc (a : ℕ) b).fin n := rfl
#align fin.uIcc_eq_finset_subtype Fin.uIcc_eq_finset_subtype
@[simp]
theorem map_valEmbedding_Icc : (Icc a b).map Fin.valEmbedding = Icc ↑a ↑b := by
simp [Icc_eq_finset_subtype, Finset.fin, Finset.map_map, Icc_filter_lt_of_lt_right]
#align fin.map_subtype_embedding_Icc Fin.map_valEmbedding_Icc
@[simp]
theorem map_valEmbedding_Ico : (Ico a b).map Fin.valEmbedding = Ico ↑a ↑b := by
simp [Ico_eq_finset_subtype, Finset.fin, Finset.map_map]
#align fin.map_subtype_embedding_Ico Fin.map_valEmbedding_Ico
@[simp]
theorem map_valEmbedding_Ioc : (Ioc a b).map Fin.valEmbedding = Ioc ↑a ↑b := by
simp [Ioc_eq_finset_subtype, Finset.fin, Finset.map_map, Ioc_filter_lt_of_lt_right]
#align fin.map_subtype_embedding_Ioc Fin.map_valEmbedding_Ioc
@[simp]
theorem map_valEmbedding_Ioo : (Ioo a b).map Fin.valEmbedding = Ioo ↑a ↑b := by
simp [Ioo_eq_finset_subtype, Finset.fin, Finset.map_map]
#align fin.map_subtype_embedding_Ioo Fin.map_valEmbedding_Ioo
@[simp]
theorem map_subtype_embedding_uIcc : (uIcc a b).map valEmbedding = uIcc ↑a ↑b :=
map_valEmbedding_Icc _ _
#align fin.map_subtype_embedding_uIcc Fin.map_subtype_embedding_uIcc
@[simp]
theorem card_Icc : (Icc a b).card = b + 1 - a := by
rw [← Nat.card_Icc, ← map_valEmbedding_Icc, card_map]
#align fin.card_Icc Fin.card_Icc
@[simp]
theorem card_Ico : (Ico a b).card = b - a := by
rw [← Nat.card_Ico, ← map_valEmbedding_Ico, card_map]
#align fin.card_Ico Fin.card_Ico
@[simp]
theorem card_Ioc : (Ioc a b).card = b - a := by
rw [← Nat.card_Ioc, ← map_valEmbedding_Ioc, card_map]
#align fin.card_Ioc Fin.card_Ioc
@[simp]
theorem card_Ioo : (Ioo a b).card = b - a - 1 := by
rw [← Nat.card_Ioo, ← map_valEmbedding_Ioo, card_map]
#align fin.card_Ioo Fin.card_Ioo
@[simp]
theorem card_uIcc : (uIcc a b).card = (b - a : ℤ).natAbs + 1 := by
rw [← Nat.card_uIcc, ← map_subtype_embedding_uIcc, card_map]
#align fin.card_uIcc Fin.card_uIcc
-- Porting note (#10618): simp can prove this
-- @[simp]
theorem card_fintypeIcc : Fintype.card (Set.Icc a b) = b + 1 - a := by
rw [← card_Icc, Fintype.card_ofFinset]
#align fin.card_fintype_Icc Fin.card_fintypeIcc
-- Porting note (#10618): simp can prove this
-- @[simp]
| Mathlib/Order/Interval/Finset/Fin.lean | 136 | 137 | theorem card_fintypeIco : Fintype.card (Set.Ico a b) = b - a := by |
rw [← card_Ico, Fintype.card_ofFinset]
|
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 Disjoint
def Disjoint (f g : Perm α) :=
∀ x, f x = x ∨ g x = x
#align equiv.perm.disjoint Equiv.Perm.Disjoint
variable {f g h : Perm α}
@[symm]
theorem Disjoint.symm : Disjoint f g → Disjoint g f := by simp only [Disjoint, or_comm, imp_self]
#align equiv.perm.disjoint.symm Equiv.Perm.Disjoint.symm
theorem Disjoint.symmetric : Symmetric (@Disjoint α) := fun _ _ => Disjoint.symm
#align equiv.perm.disjoint.symmetric Equiv.Perm.Disjoint.symmetric
instance : IsSymm (Perm α) Disjoint :=
⟨Disjoint.symmetric⟩
theorem disjoint_comm : Disjoint f g ↔ Disjoint g f :=
⟨Disjoint.symm, Disjoint.symm⟩
#align equiv.perm.disjoint_comm Equiv.Perm.disjoint_comm
theorem Disjoint.commute (h : Disjoint f g) : Commute f g :=
Equiv.ext fun x =>
(h x).elim
(fun hf =>
(h (g x)).elim (fun hg => by simp [mul_apply, hf, hg]) fun hg => by
simp [mul_apply, hf, g.injective hg])
fun hg =>
(h (f x)).elim (fun hf => by simp [mul_apply, f.injective hf, hg]) fun hf => by
simp [mul_apply, hf, hg]
#align equiv.perm.disjoint.commute Equiv.Perm.Disjoint.commute
@[simp]
theorem disjoint_one_left (f : Perm α) : Disjoint 1 f := fun _ => Or.inl rfl
#align equiv.perm.disjoint_one_left Equiv.Perm.disjoint_one_left
@[simp]
theorem disjoint_one_right (f : Perm α) : Disjoint f 1 := fun _ => Or.inr rfl
#align equiv.perm.disjoint_one_right Equiv.Perm.disjoint_one_right
theorem disjoint_iff_eq_or_eq : Disjoint f g ↔ ∀ x : α, f x = x ∨ g x = x :=
Iff.rfl
#align equiv.perm.disjoint_iff_eq_or_eq Equiv.Perm.disjoint_iff_eq_or_eq
@[simp]
theorem disjoint_refl_iff : Disjoint f f ↔ f = 1 := by
refine ⟨fun h => ?_, fun h => h.symm ▸ disjoint_one_left 1⟩
ext x
cases' h x with hx hx <;> simp [hx]
#align equiv.perm.disjoint_refl_iff Equiv.Perm.disjoint_refl_iff
theorem Disjoint.inv_left (h : Disjoint f g) : Disjoint f⁻¹ g := by
intro x
rw [inv_eq_iff_eq, eq_comm]
exact h x
#align equiv.perm.disjoint.inv_left Equiv.Perm.Disjoint.inv_left
theorem Disjoint.inv_right (h : Disjoint f g) : Disjoint f g⁻¹ :=
h.symm.inv_left.symm
#align equiv.perm.disjoint.inv_right Equiv.Perm.Disjoint.inv_right
@[simp]
| Mathlib/GroupTheory/Perm/Support.lean | 104 | 106 | theorem disjoint_inv_left_iff : Disjoint f⁻¹ g ↔ Disjoint f g := by |
refine ⟨fun h => ?_, Disjoint.inv_left⟩
convert h.inv_left
|
import Mathlib.Data.Set.Prod
#align_import data.set.n_ary from "leanprover-community/mathlib"@"5e526d18cea33550268dcbbddcb822d5cde40654"
open Function
namespace Set
variable {α α' β β' γ γ' δ δ' ε ε' ζ ζ' ν : Type*} {f f' : α → β → γ} {g g' : α → β → γ → δ}
variable {s s' : Set α} {t t' : Set β} {u u' : Set γ} {v : Set δ} {a a' : α} {b b' : β} {c c' : γ}
{d d' : δ}
theorem mem_image2_iff (hf : Injective2 f) : f a b ∈ image2 f s t ↔ a ∈ s ∧ b ∈ t :=
⟨by
rintro ⟨a', ha', b', hb', h⟩
rcases hf h with ⟨rfl, rfl⟩
exact ⟨ha', hb'⟩, fun ⟨ha, hb⟩ => mem_image2_of_mem ha hb⟩
#align set.mem_image2_iff Set.mem_image2_iff
theorem image2_subset (hs : s ⊆ s') (ht : t ⊆ t') : image2 f s t ⊆ image2 f s' t' := by
rintro _ ⟨a, ha, b, hb, rfl⟩
exact mem_image2_of_mem (hs ha) (ht hb)
#align set.image2_subset Set.image2_subset
theorem image2_subset_left (ht : t ⊆ t') : image2 f s t ⊆ image2 f s t' :=
image2_subset Subset.rfl ht
#align set.image2_subset_left Set.image2_subset_left
theorem image2_subset_right (hs : s ⊆ s') : image2 f s t ⊆ image2 f s' t :=
image2_subset hs Subset.rfl
#align set.image2_subset_right Set.image2_subset_right
theorem image_subset_image2_left (hb : b ∈ t) : (fun a => f a b) '' s ⊆ image2 f s t :=
forall_mem_image.2 fun _ ha => mem_image2_of_mem ha hb
#align set.image_subset_image2_left Set.image_subset_image2_left
theorem image_subset_image2_right (ha : a ∈ s) : f a '' t ⊆ image2 f s t :=
forall_mem_image.2 fun _ => mem_image2_of_mem ha
#align set.image_subset_image2_right Set.image_subset_image2_right
theorem forall_image2_iff {p : γ → Prop} :
(∀ z ∈ image2 f s t, p z) ↔ ∀ x ∈ s, ∀ y ∈ t, p (f x y) :=
⟨fun h x hx y hy => h _ ⟨x, hx, y, hy, rfl⟩, fun h _ ⟨x, hx, y, hy, hz⟩ => hz ▸ h x hx y hy⟩
#align set.forall_image2_iff Set.forall_image2_iff
@[simp]
theorem image2_subset_iff {u : Set γ} : image2 f s t ⊆ u ↔ ∀ x ∈ s, ∀ y ∈ t, f x y ∈ u :=
forall_image2_iff
#align set.image2_subset_iff Set.image2_subset_iff
theorem image2_subset_iff_left : image2 f s t ⊆ u ↔ ∀ a ∈ s, (fun b => f a b) '' t ⊆ u := by
simp_rw [image2_subset_iff, image_subset_iff, subset_def, mem_preimage]
#align set.image2_subset_iff_left Set.image2_subset_iff_left
theorem image2_subset_iff_right : image2 f s t ⊆ u ↔ ∀ b ∈ t, (fun a => f a b) '' s ⊆ u := by
simp_rw [image2_subset_iff, image_subset_iff, subset_def, mem_preimage, @forall₂_swap α]
#align set.image2_subset_iff_right Set.image2_subset_iff_right
variable (f)
-- Porting note: Removing `simp` - LHS does not simplify
lemma image_prod : (fun x : α × β ↦ f x.1 x.2) '' s ×ˢ t = image2 f s t :=
ext fun _ ↦ by simp [and_assoc]
#align set.image_prod Set.image_prod
@[simp] lemma image_uncurry_prod (s : Set α) (t : Set β) : uncurry f '' s ×ˢ t = image2 f s t :=
image_prod _
#align set.image_uncurry_prod Set.image_uncurry_prod
@[simp] lemma image2_mk_eq_prod : image2 Prod.mk s t = s ×ˢ t := ext <| by simp
#align set.image2_mk_eq_prod Set.image2_mk_eq_prod
-- Porting note: Removing `simp` - LHS does not simplify
lemma image2_curry (f : α × β → γ) (s : Set α) (t : Set β) :
image2 (fun a b ↦ f (a, b)) s t = f '' s ×ˢ t := by
simp [← image_uncurry_prod, uncurry]
#align set.image2_curry Set.image2_curry
theorem image2_swap (s : Set α) (t : Set β) : image2 f s t = image2 (fun a b => f b a) t s := by
ext
constructor <;> rintro ⟨a, ha, b, hb, rfl⟩ <;> exact ⟨b, hb, a, ha, rfl⟩
#align set.image2_swap Set.image2_swap
variable {f}
theorem image2_union_left : image2 f (s ∪ s') t = image2 f s t ∪ image2 f s' t := by
simp_rw [← image_prod, union_prod, image_union]
#align set.image2_union_left Set.image2_union_left
theorem image2_union_right : image2 f s (t ∪ t') = image2 f s t ∪ image2 f s t' := by
rw [← image2_swap, image2_union_left, image2_swap f, image2_swap f]
#align set.image2_union_right Set.image2_union_right
lemma image2_inter_left (hf : Injective2 f) :
image2 f (s ∩ s') t = image2 f s t ∩ image2 f s' t := by
simp_rw [← image_uncurry_prod, inter_prod, image_inter hf.uncurry]
#align set.image2_inter_left Set.image2_inter_left
lemma image2_inter_right (hf : Injective2 f) :
image2 f s (t ∩ t') = image2 f s t ∩ image2 f s t' := by
simp_rw [← image_uncurry_prod, prod_inter, image_inter hf.uncurry]
#align set.image2_inter_right Set.image2_inter_right
@[simp]
theorem image2_empty_left : image2 f ∅ t = ∅ :=
ext <| by simp
#align set.image2_empty_left Set.image2_empty_left
@[simp]
theorem image2_empty_right : image2 f s ∅ = ∅ :=
ext <| by simp
#align set.image2_empty_right Set.image2_empty_right
theorem Nonempty.image2 : s.Nonempty → t.Nonempty → (image2 f s t).Nonempty :=
fun ⟨_, ha⟩ ⟨_, hb⟩ => ⟨_, mem_image2_of_mem ha hb⟩
#align set.nonempty.image2 Set.Nonempty.image2
@[simp]
theorem image2_nonempty_iff : (image2 f s t).Nonempty ↔ s.Nonempty ∧ t.Nonempty :=
⟨fun ⟨_, a, ha, b, hb, _⟩ => ⟨⟨a, ha⟩, b, hb⟩, fun h => h.1.image2 h.2⟩
#align set.image2_nonempty_iff Set.image2_nonempty_iff
theorem Nonempty.of_image2_left (h : (Set.image2 f s t).Nonempty) : s.Nonempty :=
(image2_nonempty_iff.1 h).1
#align set.nonempty.of_image2_left Set.Nonempty.of_image2_left
theorem Nonempty.of_image2_right (h : (Set.image2 f s t).Nonempty) : t.Nonempty :=
(image2_nonempty_iff.1 h).2
#align set.nonempty.of_image2_right Set.Nonempty.of_image2_right
@[simp]
theorem image2_eq_empty_iff : image2 f s t = ∅ ↔ s = ∅ ∨ t = ∅ := by
rw [← not_nonempty_iff_eq_empty, image2_nonempty_iff, not_and_or]
simp [not_nonempty_iff_eq_empty]
#align set.image2_eq_empty_iff Set.image2_eq_empty_iff
theorem Subsingleton.image2 (hs : s.Subsingleton) (ht : t.Subsingleton) (f : α → β → γ) :
(image2 f s t).Subsingleton := by
rw [← image_prod]
apply (hs.prod ht).image
theorem image2_inter_subset_left : image2 f (s ∩ s') t ⊆ image2 f s t ∩ image2 f s' t :=
Monotone.map_inf_le (fun _ _ ↦ image2_subset_right) s s'
#align set.image2_inter_subset_left Set.image2_inter_subset_left
theorem image2_inter_subset_right : image2 f s (t ∩ t') ⊆ image2 f s t ∩ image2 f s t' :=
Monotone.map_inf_le (fun _ _ ↦ image2_subset_left) t t'
#align set.image2_inter_subset_right Set.image2_inter_subset_right
@[simp]
theorem image2_singleton_left : image2 f {a} t = f a '' t :=
ext fun x => by simp
#align set.image2_singleton_left Set.image2_singleton_left
@[simp]
theorem image2_singleton_right : image2 f s {b} = (fun a => f a b) '' s :=
ext fun x => by simp
#align set.image2_singleton_right Set.image2_singleton_right
theorem image2_singleton : image2 f {a} {b} = {f a b} := by simp
#align set.image2_singleton Set.image2_singleton
@[simp]
theorem image2_insert_left : image2 f (insert a s) t = (fun b => f a b) '' t ∪ image2 f s t := by
rw [insert_eq, image2_union_left, image2_singleton_left]
#align set.image2_insert_left Set.image2_insert_left
@[simp]
theorem image2_insert_right : image2 f s (insert b t) = (fun a => f a b) '' s ∪ image2 f s t := by
rw [insert_eq, image2_union_right, image2_singleton_right]
#align set.image2_insert_right Set.image2_insert_right
@[congr]
theorem image2_congr (h : ∀ a ∈ s, ∀ b ∈ t, f a b = f' a b) : image2 f s t = image2 f' s t := by
ext
constructor <;> rintro ⟨a, ha, b, hb, rfl⟩ <;> exact ⟨a, ha, b, hb, by rw [h a ha b hb]⟩
#align set.image2_congr Set.image2_congr
theorem image2_congr' (h : ∀ a b, f a b = f' a b) : image2 f s t = image2 f' s t :=
image2_congr fun a _ b _ => h a b
#align set.image2_congr' Set.image2_congr'
#noalign set.image3
#noalign set.mem_image3
#noalign set.image3_mono
#noalign set.image3_congr
#noalign set.image3_congr'
#noalign set.image2_image2_left
#noalign set.image2_image2_right
theorem image_image2 (f : α → β → γ) (g : γ → δ) :
g '' image2 f s t = image2 (fun a b => g (f a b)) s t := by
simp only [← image_prod, image_image]
#align set.image_image2 Set.image_image2
theorem image2_image_left (f : γ → β → δ) (g : α → γ) :
image2 f (g '' s) t = image2 (fun a b => f (g a) b) s t := by
ext; simp
#align set.image2_image_left Set.image2_image_left
theorem image2_image_right (f : α → γ → δ) (g : β → γ) :
image2 f s (g '' t) = image2 (fun a b => f a (g b)) s t := by
ext; simp
#align set.image2_image_right Set.image2_image_right
@[simp]
theorem image2_left (h : t.Nonempty) : image2 (fun x _ => x) s t = s := by
simp [nonempty_def.mp h, ext_iff]
#align set.image2_left Set.image2_left
@[simp]
theorem image2_right (h : s.Nonempty) : image2 (fun _ y => y) s t = t := by
simp [nonempty_def.mp h, ext_iff]
#align set.image2_right Set.image2_right
lemma image2_range (f : α' → β' → γ) (g : α → α') (h : β → β') :
image2 f (range g) (range h) = range fun x : α × β ↦ f (g x.1) (h x.2) := by
simp_rw [← image_univ, image2_image_left, image2_image_right, ← image_prod, univ_prod_univ]
theorem image2_assoc {f : δ → γ → ε} {g : α → β → δ} {f' : α → ε' → ε} {g' : β → γ → ε'}
(h_assoc : ∀ a b c, f (g a b) c = f' a (g' b c)) :
image2 f (image2 g s t) u = image2 f' s (image2 g' t u) :=
eq_of_forall_subset_iff fun _ ↦ by simp only [image2_subset_iff, forall_image2_iff, h_assoc]
#align set.image2_assoc Set.image2_assoc
theorem image2_comm {g : β → α → γ} (h_comm : ∀ a b, f a b = g b a) : image2 f s t = image2 g t s :=
(image2_swap _ _ _).trans <| by simp_rw [h_comm]
#align set.image2_comm Set.image2_comm
theorem image2_left_comm {f : α → δ → ε} {g : β → γ → δ} {f' : α → γ → δ'} {g' : β → δ' → ε}
(h_left_comm : ∀ a b c, f a (g b c) = g' b (f' a c)) :
image2 f s (image2 g t u) = image2 g' t (image2 f' s u) := by
rw [image2_swap f', image2_swap f]
exact image2_assoc fun _ _ _ => h_left_comm _ _ _
#align set.image2_left_comm Set.image2_left_comm
theorem image2_right_comm {f : δ → γ → ε} {g : α → β → δ} {f' : α → γ → δ'} {g' : δ' → β → ε}
(h_right_comm : ∀ a b c, f (g a b) c = g' (f' a c) b) :
image2 f (image2 g s t) u = image2 g' (image2 f' s u) t := by
rw [image2_swap g, image2_swap g']
exact image2_assoc fun _ _ _ => h_right_comm _ _ _
#align set.image2_right_comm Set.image2_right_comm
theorem image2_image2_image2_comm {f : ε → ζ → ν} {g : α → β → ε} {h : γ → δ → ζ} {f' : ε' → ζ' → ν}
{g' : α → γ → ε'} {h' : β → δ → ζ'}
(h_comm : ∀ a b c d, f (g a b) (h c d) = f' (g' a c) (h' b d)) :
image2 f (image2 g s t) (image2 h u v) = image2 f' (image2 g' s u) (image2 h' t v) := by
ext; constructor
· rintro ⟨_, ⟨a, ha, b, hb, rfl⟩, _, ⟨c, hc, d, hd, rfl⟩, rfl⟩
exact ⟨_, ⟨a, ha, c, hc, rfl⟩, _, ⟨b, hb, d, hd, rfl⟩, (h_comm _ _ _ _).symm⟩
· rintro ⟨_, ⟨a, ha, c, hc, rfl⟩, _, ⟨b, hb, d, hd, rfl⟩, rfl⟩
exact ⟨_, ⟨a, ha, b, hb, rfl⟩, _, ⟨c, hc, d, hd, rfl⟩, h_comm _ _ _ _⟩
#align set.image2_image2_image2_comm Set.image2_image2_image2_comm
theorem image_image2_distrib {g : γ → δ} {f' : α' → β' → δ} {g₁ : α → α'} {g₂ : β → β'}
(h_distrib : ∀ a b, g (f a b) = f' (g₁ a) (g₂ b)) :
(image2 f s t).image g = image2 f' (s.image g₁) (t.image g₂) := by
simp_rw [image_image2, image2_image_left, image2_image_right, h_distrib]
#align set.image_image2_distrib Set.image_image2_distrib
theorem image_image2_distrib_left {g : γ → δ} {f' : α' → β → δ} {g' : α → α'}
(h_distrib : ∀ a b, g (f a b) = f' (g' a) b) :
(image2 f s t).image g = image2 f' (s.image g') t :=
(image_image2_distrib h_distrib).trans <| by rw [image_id']
#align set.image_image2_distrib_left Set.image_image2_distrib_left
theorem image_image2_distrib_right {g : γ → δ} {f' : α → β' → δ} {g' : β → β'}
(h_distrib : ∀ a b, g (f a b) = f' a (g' b)) :
(image2 f s t).image g = image2 f' s (t.image g') :=
(image_image2_distrib h_distrib).trans <| by rw [image_id']
#align set.image_image2_distrib_right Set.image_image2_distrib_right
theorem image2_image_left_comm {f : α' → β → γ} {g : α → α'} {f' : α → β → δ} {g' : δ → γ}
(h_left_comm : ∀ a b, f (g a) b = g' (f' a b)) :
image2 f (s.image g) t = (image2 f' s t).image g' :=
(image_image2_distrib_left fun a b => (h_left_comm a b).symm).symm
#align set.image2_image_left_comm Set.image2_image_left_comm
theorem image_image2_right_comm {f : α → β' → γ} {g : β → β'} {f' : α → β → δ} {g' : δ → γ}
(h_right_comm : ∀ a b, f a (g b) = g' (f' a b)) :
image2 f s (t.image g) = (image2 f' s t).image g' :=
(image_image2_distrib_right fun a b => (h_right_comm a b).symm).symm
#align set.image_image2_right_comm Set.image_image2_right_comm
| Mathlib/Data/Set/NAry.lean | 308 | 313 | theorem image2_distrib_subset_left {f : α → δ → ε} {g : β → γ → δ} {f₁ : α → β → β'}
{f₂ : α → γ → γ'} {g' : β' → γ' → ε} (h_distrib : ∀ a b c, f a (g b c) = g' (f₁ a b) (f₂ a c)) :
image2 f s (image2 g t u) ⊆ image2 g' (image2 f₁ s t) (image2 f₂ s u) := by |
rintro _ ⟨a, ha, _, ⟨b, hb, c, hc, rfl⟩, rfl⟩
rw [h_distrib]
exact mem_image2_of_mem (mem_image2_of_mem ha hb) (mem_image2_of_mem ha hc)
|
import Mathlib.Data.ENNReal.Inv
#align_import data.real.ennreal from "leanprover-community/mathlib"@"c14c8fcde993801fca8946b0d80131a1a81d1520"
open Set NNReal ENNReal
namespace ENNReal
section iInf
variable {ι : Sort*} {f g : ι → ℝ≥0∞}
variable {a b c d : ℝ≥0∞} {r p q : ℝ≥0}
theorem toNNReal_iInf (hf : ∀ i, f i ≠ ∞) : (iInf f).toNNReal = ⨅ i, (f i).toNNReal := by
cases isEmpty_or_nonempty ι
· rw [iInf_of_empty, top_toNNReal, NNReal.iInf_empty]
· lift f to ι → ℝ≥0 using hf
simp_rw [← coe_iInf, toNNReal_coe]
#align ennreal.to_nnreal_infi ENNReal.toNNReal_iInf
theorem toNNReal_sInf (s : Set ℝ≥0∞) (hs : ∀ r ∈ s, r ≠ ∞) :
(sInf s).toNNReal = sInf (ENNReal.toNNReal '' s) := by
have hf : ∀ i, ((↑) : s → ℝ≥0∞) i ≠ ∞ := fun ⟨r, rs⟩ => hs r rs
-- Porting note: `← sInf_image'` had to be replaced by `← image_eq_range` as the lemmas are used
-- in a different order.
simpa only [← sInf_range, ← image_eq_range, Subtype.range_coe_subtype] using (toNNReal_iInf hf)
#align ennreal.to_nnreal_Inf ENNReal.toNNReal_sInf
theorem toNNReal_iSup (hf : ∀ i, f i ≠ ∞) : (iSup f).toNNReal = ⨆ i, (f i).toNNReal := by
lift f to ι → ℝ≥0 using hf
simp_rw [toNNReal_coe]
by_cases h : BddAbove (range f)
· rw [← coe_iSup h, toNNReal_coe]
· rw [NNReal.iSup_of_not_bddAbove h, iSup_coe_eq_top.2 h, top_toNNReal]
#align ennreal.to_nnreal_supr ENNReal.toNNReal_iSup
theorem toNNReal_sSup (s : Set ℝ≥0∞) (hs : ∀ r ∈ s, r ≠ ∞) :
(sSup s).toNNReal = sSup (ENNReal.toNNReal '' s) := by
have hf : ∀ i, ((↑) : s → ℝ≥0∞) i ≠ ∞ := fun ⟨r, rs⟩ => hs r rs
-- Porting note: `← sSup_image'` had to be replaced by `← image_eq_range` as the lemmas are used
-- in a different order.
simpa only [← sSup_range, ← image_eq_range, Subtype.range_coe_subtype] using (toNNReal_iSup hf)
#align ennreal.to_nnreal_Sup ENNReal.toNNReal_sSup
theorem toReal_iInf (hf : ∀ i, f i ≠ ∞) : (iInf f).toReal = ⨅ i, (f i).toReal := by
simp only [ENNReal.toReal, toNNReal_iInf hf, NNReal.coe_iInf]
#align ennreal.to_real_infi ENNReal.toReal_iInf
| Mathlib/Data/ENNReal/Real.lean | 576 | 578 | theorem toReal_sInf (s : Set ℝ≥0∞) (hf : ∀ r ∈ s, r ≠ ∞) :
(sInf s).toReal = sInf (ENNReal.toReal '' s) := by |
simp only [ENNReal.toReal, toNNReal_sInf s hf, NNReal.coe_sInf, Set.image_image]
|
import Mathlib.Data.Finset.Card
#align_import data.finset.prod from "leanprover-community/mathlib"@"9003f28797c0664a49e4179487267c494477d853"
assert_not_exists MonoidWithZero
open Multiset
variable {α β γ : Type*}
namespace Finset
section Prod
variable {s s' : Finset α} {t t' : Finset β} {a : α} {b : β}
protected def product (s : Finset α) (t : Finset β) : Finset (α × β) :=
⟨_, s.nodup.product t.nodup⟩
#align finset.product Finset.product
instance instSProd : SProd (Finset α) (Finset β) (Finset (α × β)) where
sprod := Finset.product
@[simp]
theorem product_val : (s ×ˢ t).1 = s.1 ×ˢ t.1 :=
rfl
#align finset.product_val Finset.product_val
@[simp]
theorem mem_product {p : α × β} : p ∈ s ×ˢ t ↔ p.1 ∈ s ∧ p.2 ∈ t :=
Multiset.mem_product
#align finset.mem_product Finset.mem_product
theorem mk_mem_product (ha : a ∈ s) (hb : b ∈ t) : (a, b) ∈ s ×ˢ t :=
mem_product.2 ⟨ha, hb⟩
#align finset.mk_mem_product Finset.mk_mem_product
@[simp, norm_cast]
theorem coe_product (s : Finset α) (t : Finset β) :
(↑(s ×ˢ t) : Set (α × β)) = (s : Set α) ×ˢ t :=
Set.ext fun _ => Finset.mem_product
#align finset.coe_product Finset.coe_product
theorem subset_product_image_fst [DecidableEq α] : (s ×ˢ t).image Prod.fst ⊆ s := fun i => by
simp (config := { contextual := true }) [mem_image]
#align finset.subset_product_image_fst Finset.subset_product_image_fst
theorem subset_product_image_snd [DecidableEq β] : (s ×ˢ t).image Prod.snd ⊆ t := fun i => by
simp (config := { contextual := true }) [mem_image]
#align finset.subset_product_image_snd Finset.subset_product_image_snd
theorem product_image_fst [DecidableEq α] (ht : t.Nonempty) : (s ×ˢ t).image Prod.fst = s := by
ext i
simp [mem_image, ht.exists_mem]
#align finset.product_image_fst Finset.product_image_fst
theorem product_image_snd [DecidableEq β] (ht : s.Nonempty) : (s ×ˢ t).image Prod.snd = t := by
ext i
simp [mem_image, ht.exists_mem]
#align finset.product_image_snd Finset.product_image_snd
theorem subset_product [DecidableEq α] [DecidableEq β] {s : Finset (α × β)} :
s ⊆ s.image Prod.fst ×ˢ s.image Prod.snd := fun _ hp =>
mem_product.2 ⟨mem_image_of_mem _ hp, mem_image_of_mem _ hp⟩
#align finset.subset_product Finset.subset_product
@[gcongr]
theorem product_subset_product (hs : s ⊆ s') (ht : t ⊆ t') : s ×ˢ t ⊆ s' ×ˢ t' := fun ⟨_, _⟩ h =>
mem_product.2 ⟨hs (mem_product.1 h).1, ht (mem_product.1 h).2⟩
#align finset.product_subset_product Finset.product_subset_product
@[gcongr]
theorem product_subset_product_left (hs : s ⊆ s') : s ×ˢ t ⊆ s' ×ˢ t :=
product_subset_product hs (Subset.refl _)
#align finset.product_subset_product_left Finset.product_subset_product_left
@[gcongr]
theorem product_subset_product_right (ht : t ⊆ t') : s ×ˢ t ⊆ s ×ˢ t' :=
product_subset_product (Subset.refl _) ht
#align finset.product_subset_product_right Finset.product_subset_product_right
theorem map_swap_product (s : Finset α) (t : Finset β) :
(t ×ˢ s).map ⟨Prod.swap, Prod.swap_injective⟩ = s ×ˢ t :=
coe_injective <| by
push_cast
exact Set.image_swap_prod _ _
#align finset.map_swap_product Finset.map_swap_product
@[simp]
theorem image_swap_product [DecidableEq (α × β)] (s : Finset α) (t : Finset β) :
(t ×ˢ s).image Prod.swap = s ×ˢ t :=
coe_injective <| by
push_cast
exact Set.image_swap_prod _ _
#align finset.image_swap_product Finset.image_swap_product
theorem product_eq_biUnion [DecidableEq (α × β)] (s : Finset α) (t : Finset β) :
s ×ˢ t = s.biUnion fun a => t.image fun b => (a, b) :=
ext fun ⟨x, y⟩ => by
simp only [mem_product, mem_biUnion, mem_image, exists_prop, Prod.mk.inj_iff, and_left_comm,
exists_and_left, exists_eq_right, exists_eq_left]
#align finset.product_eq_bUnion Finset.product_eq_biUnion
theorem product_eq_biUnion_right [DecidableEq (α × β)] (s : Finset α) (t : Finset β) :
s ×ˢ t = t.biUnion fun b => s.image fun a => (a, b) :=
ext fun ⟨x, y⟩ => by
simp only [mem_product, mem_biUnion, mem_image, exists_prop, Prod.mk.inj_iff, and_left_comm,
exists_and_left, exists_eq_right, exists_eq_left]
#align finset.product_eq_bUnion_right Finset.product_eq_biUnion_right
@[simp]
theorem product_biUnion [DecidableEq γ] (s : Finset α) (t : Finset β) (f : α × β → Finset γ) :
(s ×ˢ t).biUnion f = s.biUnion fun a => t.biUnion fun b => f (a, b) := by
classical simp_rw [product_eq_biUnion, biUnion_biUnion, image_biUnion]
#align finset.product_bUnion Finset.product_biUnion
@[simp]
theorem card_product (s : Finset α) (t : Finset β) : card (s ×ˢ t) = card s * card t :=
Multiset.card_product _ _
#align finset.card_product Finset.card_product
lemma nontrivial_prod_iff : (s ×ˢ t).Nontrivial ↔
s.Nonempty ∧ t.Nonempty ∧ (s.Nontrivial ∨ t.Nontrivial) := by
simp_rw [← card_pos, ← one_lt_card_iff_nontrivial, card_product]; apply Nat.one_lt_mul_iff
theorem filter_product (p : α → Prop) (q : β → Prop) [DecidablePred p] [DecidablePred q] :
((s ×ˢ t).filter fun x : α × β => p x.1 ∧ q x.2) = s.filter p ×ˢ t.filter q := by
ext ⟨a, b⟩
simp [mem_filter, mem_product, decide_eq_true_eq, and_comm, and_left_comm, and_assoc]
#align finset.filter_product Finset.filter_product
theorem filter_product_left (p : α → Prop) [DecidablePred p] :
((s ×ˢ t).filter fun x : α × β => p x.1) = s.filter p ×ˢ t := by
simpa using filter_product p fun _ => true
#align finset.filter_product_left Finset.filter_product_left
theorem filter_product_right (q : β → Prop) [DecidablePred q] :
((s ×ˢ t).filter fun x : α × β => q x.2) = s ×ˢ t.filter q := by
simpa using filter_product (fun _ : α => true) q
#align finset.filter_product_right Finset.filter_product_right
theorem filter_product_card (s : Finset α) (t : Finset β) (p : α → Prop) (q : β → Prop)
[DecidablePred p] [DecidablePred q] :
((s ×ˢ t).filter fun x : α × β => (p x.1) = (q x.2)).card =
(s.filter p).card * (t.filter q).card +
(s.filter (¬ p ·)).card * (t.filter (¬ q ·)).card := by
classical
rw [← card_product, ← card_product, ← filter_product, ← filter_product, ← card_union_of_disjoint]
· apply congr_arg
ext ⟨a, b⟩
simp only [filter_union_right, mem_filter, mem_product]
constructor <;> intro h <;> use h.1
· simp only [h.2, Function.comp_apply, Decidable.em, and_self]
· revert h
simp only [Function.comp_apply, and_imp]
rintro _ _ (_|_) <;> simp [*]
· apply Finset.disjoint_filter_filter'
exact (disjoint_compl_right.inf_left _).inf_right _
#align finset.filter_product_card Finset.filter_product_card
@[simp]
theorem empty_product (t : Finset β) : (∅ : Finset α) ×ˢ t = ∅ :=
rfl
#align finset.empty_product Finset.empty_product
@[simp]
theorem product_empty (s : Finset α) : s ×ˢ (∅ : Finset β) = ∅ :=
eq_empty_of_forall_not_mem fun _ h => not_mem_empty _ (Finset.mem_product.1 h).2
#align finset.product_empty Finset.product_empty
theorem Nonempty.product (hs : s.Nonempty) (ht : t.Nonempty) : (s ×ˢ t).Nonempty :=
let ⟨x, hx⟩ := hs
let ⟨y, hy⟩ := ht
⟨(x, y), mem_product.2 ⟨hx, hy⟩⟩
#align finset.nonempty.product Finset.Nonempty.product
theorem Nonempty.fst (h : (s ×ˢ t).Nonempty) : s.Nonempty :=
let ⟨xy, hxy⟩ := h
⟨xy.1, (mem_product.1 hxy).1⟩
#align finset.nonempty.fst Finset.Nonempty.fst
theorem Nonempty.snd (h : (s ×ˢ t).Nonempty) : t.Nonempty :=
let ⟨xy, hxy⟩ := h
⟨xy.2, (mem_product.1 hxy).2⟩
#align finset.nonempty.snd Finset.Nonempty.snd
@[simp, aesop safe apply (rule_sets := [finsetNonempty])]
theorem nonempty_product : (s ×ˢ t).Nonempty ↔ s.Nonempty ∧ t.Nonempty :=
⟨fun h => ⟨h.fst, h.snd⟩, fun h => h.1.product h.2⟩
#align finset.nonempty_product Finset.nonempty_product
@[simp]
theorem product_eq_empty {s : Finset α} {t : Finset β} : s ×ˢ t = ∅ ↔ s = ∅ ∨ t = ∅ := by
rw [← not_nonempty_iff_eq_empty, nonempty_product, not_and_or, not_nonempty_iff_eq_empty,
not_nonempty_iff_eq_empty]
#align finset.product_eq_empty Finset.product_eq_empty
@[simp]
theorem singleton_product {a : α} :
({a} : Finset α) ×ˢ t = t.map ⟨Prod.mk a, Prod.mk.inj_left _⟩ := by
ext ⟨x, y⟩
simp [and_left_comm, eq_comm]
#align finset.singleton_product Finset.singleton_product
@[simp]
theorem product_singleton {b : β} : s ×ˢ {b} = s.map ⟨fun i => (i, b), Prod.mk.inj_right _⟩ := by
ext ⟨x, y⟩
simp [and_left_comm, eq_comm]
#align finset.product_singleton Finset.product_singleton
| Mathlib/Data/Finset/Prod.lean | 238 | 240 | theorem singleton_product_singleton {a : α} {b : β} :
({a} ×ˢ {b} : Finset _) = {(a, b)} := by |
simp only [product_singleton, Function.Embedding.coeFn_mk, map_singleton]
|
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
| Mathlib/MeasureTheory/Integral/Lebesgue.lean | 1,128 | 1,144 | 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]
|
import Mathlib.GroupTheory.Sylow
import Mathlib.GroupTheory.Transfer
#align_import group_theory.schur_zassenhaus from "leanprover-community/mathlib"@"d57133e49cf06508700ef69030cd099917e0f0de"
namespace Subgroup
open scoped Classical
universe u
namespace SchurZassenhausInduction
variable {G : Type u} [Group G] [Fintype G] {N : Subgroup G} [Normal N]
(h1 : Nat.Coprime (Fintype.card N) N.index)
(h2 : ∀ (G' : Type u) [Group G'] [Fintype G'],
Fintype.card G' < Fintype.card G → ∀ {N' : Subgroup G'} [N'.Normal],
Nat.Coprime (Fintype.card N') N'.index → ∃ H' : Subgroup G', IsComplement' N' H')
(h3 : ∀ H : Subgroup G, ¬IsComplement' N H)
private theorem step0 : N ≠ ⊥ := by
rintro rfl
exact h3 ⊤ isComplement'_bot_top
set_option backward.synthInstance.canonInstances false in -- See https://github.com/leanprover-community/mathlib4/issues/12532
private theorem step1 (K : Subgroup G) (hK : K ⊔ N = ⊤) : K = ⊤ := by
contrapose! h3
have h4 : (N.comap K.subtype).index = N.index := by
rw [← N.relindex_top_right, ← hK]
exact (relindex_sup_right K N).symm
have h5 : Fintype.card K < Fintype.card G := by
rw [← K.index_mul_card]
exact lt_mul_of_one_lt_left Fintype.card_pos (one_lt_index_of_ne_top h3)
have h6 : Nat.Coprime (Fintype.card (N.comap K.subtype)) (N.comap K.subtype).index := by
rw [h4]
rw [← Nat.card_eq_fintype_card] at h1 ⊢
exact h1.coprime_dvd_left (card_comap_dvd_of_injective N K.subtype Subtype.coe_injective)
obtain ⟨H, hH⟩ := h2 K h5 h6
replace hH : Fintype.card (H.map K.subtype) = N.index := by
rw [← relindex_bot_left_eq_card, ← relindex_comap, MonoidHom.comap_bot, Subgroup.ker_subtype,
relindex_bot_left, ← IsComplement'.index_eq_card (IsComplement'.symm hH), index_comap,
subtype_range, ← relindex_sup_right, hK, relindex_top_right]
have h7 : Fintype.card N * Fintype.card (H.map K.subtype) = Fintype.card G := by
rw [hH, ← N.index_mul_card, mul_comm]
have h8 : (Fintype.card N).Coprime (Fintype.card (H.map K.subtype)) := by
rwa [hH]
exact ⟨H.map K.subtype, isComplement'_of_coprime h7 h8⟩
private theorem step2 (K : Subgroup G) [K.Normal] (hK : K ≤ N) : K = ⊥ ∨ K = N := by
have : Function.Surjective (QuotientGroup.mk' K) := Quotient.surjective_Quotient_mk''
have h4 := step1 h1 h2 h3
contrapose! h4
have h5 : Fintype.card (G ⧸ K) < Fintype.card G := by
rw [← index_eq_card, ← K.index_mul_card, ← Nat.card_eq_fintype_card]
refine
lt_mul_of_one_lt_right (Nat.pos_of_ne_zero index_ne_zero_of_finite)
(K.one_lt_card_iff_ne_bot.mpr h4.1)
have h6 :
(Fintype.card (N.map (QuotientGroup.mk' K))).Coprime (N.map (QuotientGroup.mk' K)).index := by
have index_map := N.index_map_eq this (by rwa [QuotientGroup.ker_mk'])
have index_pos : 0 < N.index := Nat.pos_of_ne_zero index_ne_zero_of_finite
rw [index_map]
refine h1.coprime_dvd_left ?_
rw [← Nat.mul_dvd_mul_iff_left index_pos, index_mul_card, ← index_map, index_mul_card]
simp only [← Nat.card_eq_fintype_card]
exact K.card_quotient_dvd_card
obtain ⟨H, hH⟩ := h2 (G ⧸ K) h5 h6
refine ⟨H.comap (QuotientGroup.mk' K), ?_, ?_⟩
· have key : (N.map (QuotientGroup.mk' K)).comap (QuotientGroup.mk' K) = N := by
refine comap_map_eq_self ?_
rwa [QuotientGroup.ker_mk']
rwa [← key, comap_sup_eq, hH.symm.sup_eq_top, comap_top]
· rw [← comap_top (QuotientGroup.mk' K)]
intro hH'
rw [comap_injective this hH', isComplement'_top_right, map_eq_bot_iff,
QuotientGroup.ker_mk'] at hH
exact h4.2 (le_antisymm hK hH)
private theorem step3 (K : Subgroup N) [(K.map N.subtype).Normal] : K = ⊥ ∨ K = ⊤ := by
have key := step2 h1 h2 h3 (K.map N.subtype) (map_subtype_le K)
rw [← map_bot N.subtype] at key
conv at key =>
rhs
rhs
rw [← N.subtype_range, N.subtype.range_eq_map]
have inj := map_injective N.subtype_injective
rwa [inj.eq_iff, inj.eq_iff] at key
private theorem step4 : (Fintype.card N).minFac.Prime := by
rw [← Nat.card_eq_fintype_card]
exact Nat.minFac_prime (N.one_lt_card_iff_ne_bot.mpr (step0 h1 h3)).ne'
private theorem step5 {P : Sylow (Fintype.card N).minFac N} : P.1 ≠ ⊥ :=
haveI : Fact (Fintype.card N).minFac.Prime := ⟨step4 h1 h3⟩
P.ne_bot_of_dvd_card (Fintype.card N).minFac_dvd
private theorem step6 : IsPGroup (Fintype.card N).minFac N := by
haveI : Fact (Fintype.card N).minFac.Prime := ⟨step4 h1 h3⟩
refine Sylow.nonempty.elim fun P => P.2.of_surjective P.1.subtype ?_
rw [← MonoidHom.range_top_iff_surjective, subtype_range]
haveI : (P.1.map N.subtype).Normal :=
normalizer_eq_top.mp (step1 h1 h2 h3 (P.1.map N.subtype).normalizer P.normalizer_sup_eq_top)
exact (step3 h1 h2 h3 P.1).resolve_left (step5 h1 h3)
| Mathlib/GroupTheory/SchurZassenhaus.lean | 252 | 257 | theorem step7 : IsCommutative N := by |
haveI := N.bot_or_nontrivial.resolve_left (step0 h1 h3)
haveI : Fact (Fintype.card N).minFac.Prime := ⟨step4 h1 h3⟩
exact
⟨⟨fun g h => ((eq_top_iff.mp ((step3 h1 h2 h3 (center N)).resolve_left
(step6 h1 h2 h3).bot_lt_center.ne') (mem_top h)).comm g).symm⟩⟩
|
import Mathlib.NumberTheory.Zsqrtd.GaussianInt
import Mathlib.NumberTheory.LegendreSymbol.Basic
import Mathlib.Analysis.Normed.Field.Basic
#align_import number_theory.zsqrtd.quadratic_reciprocity from "leanprover-community/mathlib"@"5b2fe80501ff327b9109fb09b7cc8c325cd0d7d9"
open Zsqrtd Complex
open scoped ComplexConjugate
local notation "ℤ[i]" => GaussianInt
namespace GaussianInt
open PrincipalIdealRing
theorem mod_four_eq_three_of_nat_prime_of_prime (p : ℕ) [hp : Fact p.Prime]
(hpi : Prime (p : ℤ[i])) : p % 4 = 3 :=
hp.1.eq_two_or_odd.elim
(fun hp2 =>
absurd hpi
(mt irreducible_iff_prime.2 fun ⟨_, h⟩ => by
have := h ⟨1, 1⟩ ⟨1, -1⟩ (hp2.symm ▸ rfl)
rw [← norm_eq_one_iff, ← norm_eq_one_iff] at this
exact absurd this (by decide)))
fun hp1 =>
by_contradiction fun hp3 : p % 4 ≠ 3 => by
have hp41 : p % 4 = 1 := by
rw [← Nat.mod_mul_left_mod p 2 2, show 2 * 2 = 4 from rfl] at hp1
have := Nat.mod_lt p (show 0 < 4 by decide)
revert this hp3 hp1
generalize p % 4 = m
intros; interval_cases m <;> simp_all -- Porting note (#11043): was `decide!`
let ⟨k, hk⟩ := (ZMod.exists_sq_eq_neg_one_iff (p := p)).2 <| by rw [hp41]; decide
obtain ⟨k, k_lt_p, rfl⟩ : ∃ (k' : ℕ) (_ : k' < p), (k' : ZMod p) = k := by
exact ⟨k.val, k.val_lt, ZMod.natCast_zmod_val k⟩
have hpk : p ∣ k ^ 2 + 1 := by
rw [pow_two, ← CharP.cast_eq_zero_iff (ZMod p) p, Nat.cast_add, Nat.cast_mul, Nat.cast_one,
← hk, add_left_neg]
have hkmul : (k ^ 2 + 1 : ℤ[i]) = ⟨k, 1⟩ * ⟨k, -1⟩ := by ext <;> simp [sq]
have hkltp : 1 + k * k < p * p :=
calc
1 + k * k ≤ k + k * k := by
apply add_le_add_right
exact (Nat.pos_of_ne_zero fun (hk0 : k = 0) => by clear_aux_decl; simp_all [pow_succ'])
_ = k * (k + 1) := by simp [add_comm, mul_add]
_ < p * p := mul_lt_mul k_lt_p k_lt_p (Nat.succ_pos _) (Nat.zero_le _)
have hpk₁ : ¬(p : ℤ[i]) ∣ ⟨k, -1⟩ := fun ⟨x, hx⟩ =>
lt_irrefl (p * x : ℤ[i]).norm.natAbs <|
calc
(norm (p * x : ℤ[i])).natAbs = (Zsqrtd.norm ⟨k, -1⟩).natAbs := by rw [hx]
_ < (norm (p : ℤ[i])).natAbs := by simpa [add_comm, Zsqrtd.norm] using hkltp
_ ≤ (norm (p * x : ℤ[i])).natAbs :=
norm_le_norm_mul_left _ fun hx0 =>
show (-1 : ℤ) ≠ 0 by decide <| by simpa [hx0] using congr_arg Zsqrtd.im hx
have hpk₂ : ¬(p : ℤ[i]) ∣ ⟨k, 1⟩ := fun ⟨x, hx⟩ =>
lt_irrefl (p * x : ℤ[i]).norm.natAbs <|
calc
(norm (p * x : ℤ[i])).natAbs = (Zsqrtd.norm ⟨k, 1⟩).natAbs := by rw [hx]
_ < (norm (p : ℤ[i])).natAbs := by simpa [add_comm, Zsqrtd.norm] using hkltp
_ ≤ (norm (p * x : ℤ[i])).natAbs :=
norm_le_norm_mul_left _ fun hx0 =>
show (1 : ℤ) ≠ 0 by decide <| by simpa [hx0] using congr_arg Zsqrtd.im hx
obtain ⟨y, hy⟩ := hpk
have := hpi.2.2 ⟨k, 1⟩ ⟨k, -1⟩ ⟨y, by rw [← hkmul, ← Nat.cast_mul p, ← hy]; simp⟩
clear_aux_decl
tauto
#align gaussian_int.mod_four_eq_three_of_nat_prime_of_prime GaussianInt.mod_four_eq_three_of_nat_prime_of_prime
| Mathlib/NumberTheory/Zsqrtd/QuadraticReciprocity.lean | 86 | 93 | theorem prime_of_nat_prime_of_mod_four_eq_three (p : ℕ) [hp : Fact p.Prime] (hp3 : p % 4 = 3) :
Prime (p : ℤ[i]) :=
irreducible_iff_prime.1 <|
by_contradiction fun hpi =>
let ⟨a, b, hab⟩ := sq_add_sq_of_nat_prime_of_not_irreducible p hpi
have : ∀ a b : ZMod 4, a ^ 2 + b ^ 2 ≠ (p : ZMod 4) := by |
erw [← ZMod.natCast_mod p 4, hp3]; decide
this a b (hab ▸ by simp)
|
import Mathlib.Analysis.SpecialFunctions.Complex.Circle
import Mathlib.Geometry.Euclidean.Angle.Oriented.Basic
#align_import geometry.euclidean.angle.oriented.rotation from "leanprover-community/mathlib"@"f0c8bf9245297a541f468be517f1bde6195105e9"
noncomputable section
open FiniteDimensional Complex
open scoped Real RealInnerProductSpace ComplexConjugate
namespace Orientation
attribute [local instance] Complex.finrank_real_complex_fact
variable {V V' : Type*}
variable [NormedAddCommGroup V] [NormedAddCommGroup V']
variable [InnerProductSpace ℝ V] [InnerProductSpace ℝ V']
variable [Fact (finrank ℝ V = 2)] [Fact (finrank ℝ V' = 2)] (o : Orientation ℝ V (Fin 2))
local notation "J" => o.rightAngleRotation
def rotationAux (θ : Real.Angle) : V →ₗᵢ[ℝ] V :=
LinearMap.isometryOfInner
(Real.Angle.cos θ • LinearMap.id +
Real.Angle.sin θ • (LinearIsometryEquiv.toLinearEquiv J).toLinearMap)
(by
intro x y
simp only [RCLike.conj_to_real, id, LinearMap.smul_apply, LinearMap.add_apply,
LinearMap.id_coe, LinearEquiv.coe_coe, LinearIsometryEquiv.coe_toLinearEquiv,
Orientation.areaForm_rightAngleRotation_left, Orientation.inner_rightAngleRotation_left,
Orientation.inner_rightAngleRotation_right, inner_add_left, inner_smul_left,
inner_add_right, inner_smul_right]
linear_combination inner (𝕜 := ℝ) x y * θ.cos_sq_add_sin_sq)
#align orientation.rotation_aux Orientation.rotationAux
@[simp]
theorem rotationAux_apply (θ : Real.Angle) (x : V) :
o.rotationAux θ x = Real.Angle.cos θ • x + Real.Angle.sin θ • J x :=
rfl
#align orientation.rotation_aux_apply Orientation.rotationAux_apply
def rotation (θ : Real.Angle) : V ≃ₗᵢ[ℝ] V :=
LinearIsometryEquiv.ofLinearIsometry (o.rotationAux θ)
(Real.Angle.cos θ • LinearMap.id -
Real.Angle.sin θ • (LinearIsometryEquiv.toLinearEquiv J).toLinearMap)
(by
ext x
convert congr_arg (fun t : ℝ => t • x) θ.cos_sq_add_sin_sq using 1
· simp only [o.rightAngleRotation_rightAngleRotation, o.rotationAux_apply,
Function.comp_apply, id, LinearEquiv.coe_coe, LinearIsometry.coe_toLinearMap,
LinearIsometryEquiv.coe_toLinearEquiv, map_smul, map_sub, LinearMap.coe_comp,
LinearMap.id_coe, LinearMap.smul_apply, LinearMap.sub_apply, ← mul_smul, add_smul,
smul_add, smul_neg, smul_sub, mul_comm, sq]
abel
· simp)
(by
ext x
convert congr_arg (fun t : ℝ => t • x) θ.cos_sq_add_sin_sq using 1
· simp only [o.rightAngleRotation_rightAngleRotation, o.rotationAux_apply,
Function.comp_apply, id, LinearEquiv.coe_coe, LinearIsometry.coe_toLinearMap,
LinearIsometryEquiv.coe_toLinearEquiv, map_add, map_smul, LinearMap.coe_comp,
LinearMap.id_coe, LinearMap.smul_apply, LinearMap.sub_apply,
add_smul, smul_neg, smul_sub, smul_smul]
ring_nf
abel
· simp)
#align orientation.rotation Orientation.rotation
theorem rotation_apply (θ : Real.Angle) (x : V) :
o.rotation θ x = Real.Angle.cos θ • x + Real.Angle.sin θ • J x :=
rfl
#align orientation.rotation_apply Orientation.rotation_apply
theorem rotation_symm_apply (θ : Real.Angle) (x : V) :
(o.rotation θ).symm x = Real.Angle.cos θ • x - Real.Angle.sin θ • J x :=
rfl
#align orientation.rotation_symm_apply Orientation.rotation_symm_apply
theorem rotation_eq_matrix_toLin (θ : Real.Angle) {x : V} (hx : x ≠ 0) :
(o.rotation θ).toLinearMap =
Matrix.toLin (o.basisRightAngleRotation x hx) (o.basisRightAngleRotation x hx)
!![θ.cos, -θ.sin; θ.sin, θ.cos] := by
apply (o.basisRightAngleRotation x hx).ext
intro i
fin_cases i
· rw [Matrix.toLin_self]
simp [rotation_apply, Fin.sum_univ_succ]
· rw [Matrix.toLin_self]
simp [rotation_apply, Fin.sum_univ_succ, add_comm]
#align orientation.rotation_eq_matrix_to_lin Orientation.rotation_eq_matrix_toLin
@[simp]
theorem det_rotation (θ : Real.Angle) : LinearMap.det (o.rotation θ).toLinearMap = 1 := by
haveI : Nontrivial V :=
FiniteDimensional.nontrivial_of_finrank_eq_succ (@Fact.out (finrank ℝ V = 2) _)
obtain ⟨x, hx⟩ : ∃ x, x ≠ (0 : V) := exists_ne (0 : V)
rw [o.rotation_eq_matrix_toLin θ hx]
simpa [sq] using θ.cos_sq_add_sin_sq
#align orientation.det_rotation Orientation.det_rotation
@[simp]
theorem linearEquiv_det_rotation (θ : Real.Angle) :
LinearEquiv.det (o.rotation θ).toLinearEquiv = 1 :=
Units.ext <| by
-- Porting note: Lean can't see through `LinearEquiv.coe_det` and needed the rewrite
-- in mathlib3 this was just `units.ext <| o.det_rotation θ`
simpa only [LinearEquiv.coe_det, Units.val_one] using o.det_rotation θ
#align orientation.linear_equiv_det_rotation Orientation.linearEquiv_det_rotation
@[simp]
theorem rotation_symm (θ : Real.Angle) : (o.rotation θ).symm = o.rotation (-θ) := by
ext; simp [o.rotation_apply, o.rotation_symm_apply, sub_eq_add_neg]
#align orientation.rotation_symm Orientation.rotation_symm
@[simp]
theorem rotation_zero : o.rotation 0 = LinearIsometryEquiv.refl ℝ V := by ext; simp [rotation]
#align orientation.rotation_zero Orientation.rotation_zero
@[simp]
theorem rotation_pi : o.rotation π = LinearIsometryEquiv.neg ℝ := by
ext x
simp [rotation]
#align orientation.rotation_pi Orientation.rotation_pi
theorem rotation_pi_apply (x : V) : o.rotation π x = -x := by simp
#align orientation.rotation_pi_apply Orientation.rotation_pi_apply
theorem rotation_pi_div_two : o.rotation (π / 2 : ℝ) = J := by
ext x
simp [rotation]
#align orientation.rotation_pi_div_two Orientation.rotation_pi_div_two
@[simp]
theorem rotation_rotation (θ₁ θ₂ : Real.Angle) (x : V) :
o.rotation θ₁ (o.rotation θ₂ x) = o.rotation (θ₁ + θ₂) x := by
simp only [o.rotation_apply, ← mul_smul, Real.Angle.cos_add, Real.Angle.sin_add, add_smul,
sub_smul, LinearIsometryEquiv.trans_apply, smul_add, LinearIsometryEquiv.map_add,
LinearIsometryEquiv.map_smul, rightAngleRotation_rightAngleRotation, smul_neg]
ring_nf
abel
#align orientation.rotation_rotation Orientation.rotation_rotation
@[simp]
theorem rotation_trans (θ₁ θ₂ : Real.Angle) :
(o.rotation θ₁).trans (o.rotation θ₂) = o.rotation (θ₂ + θ₁) :=
LinearIsometryEquiv.ext fun _ => by rw [← rotation_rotation, LinearIsometryEquiv.trans_apply]
#align orientation.rotation_trans Orientation.rotation_trans
@[simp]
theorem kahler_rotation_left (x y : V) (θ : Real.Angle) :
o.kahler (o.rotation θ x) y = conj (θ.expMapCircle : ℂ) * o.kahler x y := by
-- Porting note: this needed the `Complex.conj_ofReal` instead of `RCLike.conj_ofReal`;
-- I believe this is because the respective coercions are no longer defeq, and
-- `Real.Angle.coe_expMapCircle` uses the `Complex` version.
simp only [o.rotation_apply, map_add, map_mul, LinearMap.map_smulₛₗ, RingHom.id_apply,
LinearMap.add_apply, LinearMap.smul_apply, real_smul, kahler_rightAngleRotation_left,
Real.Angle.coe_expMapCircle, Complex.conj_ofReal, conj_I]
ring
#align orientation.kahler_rotation_left Orientation.kahler_rotation_left
theorem neg_rotation (θ : Real.Angle) (x : V) : -o.rotation θ x = o.rotation (π + θ) x := by
rw [← o.rotation_pi_apply, rotation_rotation]
#align orientation.neg_rotation Orientation.neg_rotation
@[simp]
theorem neg_rotation_neg_pi_div_two (x : V) :
-o.rotation (-π / 2 : ℝ) x = o.rotation (π / 2 : ℝ) x := by
rw [neg_rotation, ← Real.Angle.coe_add, neg_div, ← sub_eq_add_neg, sub_half]
#align orientation.neg_rotation_neg_pi_div_two Orientation.neg_rotation_neg_pi_div_two
theorem neg_rotation_pi_div_two (x : V) : -o.rotation (π / 2 : ℝ) x = o.rotation (-π / 2 : ℝ) x :=
(neg_eq_iff_eq_neg.mp <| o.neg_rotation_neg_pi_div_two _).symm
#align orientation.neg_rotation_pi_div_two Orientation.neg_rotation_pi_div_two
theorem kahler_rotation_left' (x y : V) (θ : Real.Angle) :
o.kahler (o.rotation θ x) y = (-θ).expMapCircle * o.kahler x y := by
simp only [Real.Angle.expMapCircle_neg, coe_inv_circle_eq_conj, kahler_rotation_left]
#align orientation.kahler_rotation_left' Orientation.kahler_rotation_left'
@[simp]
theorem kahler_rotation_right (x y : V) (θ : Real.Angle) :
o.kahler x (o.rotation θ y) = θ.expMapCircle * o.kahler x y := by
simp only [o.rotation_apply, map_add, LinearMap.map_smulₛₗ, RingHom.id_apply, real_smul,
kahler_rightAngleRotation_right, Real.Angle.coe_expMapCircle]
ring
#align orientation.kahler_rotation_right Orientation.kahler_rotation_right
@[simp]
theorem oangle_rotation_left {x y : V} (hx : x ≠ 0) (hy : y ≠ 0) (θ : Real.Angle) :
o.oangle (o.rotation θ x) y = o.oangle x y - θ := by
simp only [oangle, o.kahler_rotation_left']
rw [Complex.arg_mul_coe_angle, Real.Angle.arg_expMapCircle]
· abel
· exact ne_zero_of_mem_circle _
· exact o.kahler_ne_zero hx hy
#align orientation.oangle_rotation_left Orientation.oangle_rotation_left
@[simp]
theorem oangle_rotation_right {x y : V} (hx : x ≠ 0) (hy : y ≠ 0) (θ : Real.Angle) :
o.oangle x (o.rotation θ y) = o.oangle x y + θ := by
simp only [oangle, o.kahler_rotation_right]
rw [Complex.arg_mul_coe_angle, Real.Angle.arg_expMapCircle]
· abel
· exact ne_zero_of_mem_circle _
· exact o.kahler_ne_zero hx hy
#align orientation.oangle_rotation_right Orientation.oangle_rotation_right
@[simp]
theorem oangle_rotation_self_left {x : V} (hx : x ≠ 0) (θ : Real.Angle) :
o.oangle (o.rotation θ x) x = -θ := by simp [hx]
#align orientation.oangle_rotation_self_left Orientation.oangle_rotation_self_left
@[simp]
theorem oangle_rotation_self_right {x : V} (hx : x ≠ 0) (θ : Real.Angle) :
o.oangle x (o.rotation θ x) = θ := by simp [hx]
#align orientation.oangle_rotation_self_right Orientation.oangle_rotation_self_right
@[simp]
theorem oangle_rotation_oangle_left (x y : V) : o.oangle (o.rotation (o.oangle x y) x) y = 0 := by
by_cases hx : x = 0
· simp [hx]
· by_cases hy : y = 0
· simp [hy]
· simp [hx, hy]
#align orientation.oangle_rotation_oangle_left Orientation.oangle_rotation_oangle_left
@[simp]
theorem oangle_rotation_oangle_right (x y : V) : o.oangle y (o.rotation (o.oangle x y) x) = 0 := by
rw [oangle_rev]
simp
#align orientation.oangle_rotation_oangle_right Orientation.oangle_rotation_oangle_right
@[simp]
theorem oangle_rotation (x y : V) (θ : Real.Angle) :
o.oangle (o.rotation θ x) (o.rotation θ y) = o.oangle x y := by
by_cases hx : x = 0 <;> by_cases hy : y = 0 <;> simp [hx, hy]
#align orientation.oangle_rotation Orientation.oangle_rotation
@[simp]
theorem rotation_eq_self_iff_angle_eq_zero {x : V} (hx : x ≠ 0) (θ : Real.Angle) :
o.rotation θ x = x ↔ θ = 0 := by
constructor
· intro h
rw [eq_comm]
simpa [hx, h] using o.oangle_rotation_right hx hx θ
· intro h
simp [h]
#align orientation.rotation_eq_self_iff_angle_eq_zero Orientation.rotation_eq_self_iff_angle_eq_zero
@[simp]
theorem eq_rotation_self_iff_angle_eq_zero {x : V} (hx : x ≠ 0) (θ : Real.Angle) :
x = o.rotation θ x ↔ θ = 0 := by rw [← o.rotation_eq_self_iff_angle_eq_zero hx, eq_comm]
#align orientation.eq_rotation_self_iff_angle_eq_zero Orientation.eq_rotation_self_iff_angle_eq_zero
theorem rotation_eq_self_iff (x : V) (θ : Real.Angle) : o.rotation θ x = x ↔ x = 0 ∨ θ = 0 := by
by_cases h : x = 0 <;> simp [h]
#align orientation.rotation_eq_self_iff Orientation.rotation_eq_self_iff
theorem eq_rotation_self_iff (x : V) (θ : Real.Angle) : x = o.rotation θ x ↔ x = 0 ∨ θ = 0 := by
rw [← rotation_eq_self_iff, eq_comm]
#align orientation.eq_rotation_self_iff Orientation.eq_rotation_self_iff
@[simp]
theorem rotation_oangle_eq_iff_norm_eq (x y : V) : o.rotation (o.oangle x y) x = y ↔ ‖x‖ = ‖y‖ := by
constructor
· intro h
rw [← h, LinearIsometryEquiv.norm_map]
· intro h
rw [o.eq_iff_oangle_eq_zero_of_norm_eq] <;> simp [h]
#align orientation.rotation_oangle_eq_iff_norm_eq Orientation.rotation_oangle_eq_iff_norm_eq
theorem oangle_eq_iff_eq_norm_div_norm_smul_rotation_of_ne_zero {x y : V} (hx : x ≠ 0) (hy : y ≠ 0)
(θ : Real.Angle) : o.oangle x y = θ ↔ y = (‖y‖ / ‖x‖) • o.rotation θ x := by
have hp := div_pos (norm_pos_iff.2 hy) (norm_pos_iff.2 hx)
constructor
· rintro rfl
rw [← LinearIsometryEquiv.map_smul, ← o.oangle_smul_left_of_pos x y hp, eq_comm,
rotation_oangle_eq_iff_norm_eq, norm_smul, Real.norm_of_nonneg hp.le,
div_mul_cancel₀ _ (norm_ne_zero_iff.2 hx)]
· intro hye
rw [hye, o.oangle_smul_right_of_pos _ _ hp, o.oangle_rotation_self_right hx]
#align orientation.oangle_eq_iff_eq_norm_div_norm_smul_rotation_of_ne_zero Orientation.oangle_eq_iff_eq_norm_div_norm_smul_rotation_of_ne_zero
theorem oangle_eq_iff_eq_pos_smul_rotation_of_ne_zero {x y : V} (hx : x ≠ 0) (hy : y ≠ 0)
(θ : Real.Angle) : o.oangle x y = θ ↔ ∃ r : ℝ, 0 < r ∧ y = r • o.rotation θ x := by
constructor
· intro h
rw [o.oangle_eq_iff_eq_norm_div_norm_smul_rotation_of_ne_zero hx hy] at h
exact ⟨‖y‖ / ‖x‖, div_pos (norm_pos_iff.2 hy) (norm_pos_iff.2 hx), h⟩
· rintro ⟨r, hr, rfl⟩
rw [o.oangle_smul_right_of_pos _ _ hr, o.oangle_rotation_self_right hx]
#align orientation.oangle_eq_iff_eq_pos_smul_rotation_of_ne_zero Orientation.oangle_eq_iff_eq_pos_smul_rotation_of_ne_zero
theorem oangle_eq_iff_eq_norm_div_norm_smul_rotation_or_eq_zero {x y : V} (θ : Real.Angle) :
o.oangle x y = θ ↔
x ≠ 0 ∧ y ≠ 0 ∧ y = (‖y‖ / ‖x‖) • o.rotation θ x ∨ θ = 0 ∧ (x = 0 ∨ y = 0) := by
by_cases hx : x = 0
· simp [hx, eq_comm]
· by_cases hy : y = 0
· simp [hy, eq_comm]
· rw [o.oangle_eq_iff_eq_norm_div_norm_smul_rotation_of_ne_zero hx hy]
simp [hx, hy]
#align orientation.oangle_eq_iff_eq_norm_div_norm_smul_rotation_or_eq_zero Orientation.oangle_eq_iff_eq_norm_div_norm_smul_rotation_or_eq_zero
theorem oangle_eq_iff_eq_pos_smul_rotation_or_eq_zero {x y : V} (θ : Real.Angle) :
o.oangle x y = θ ↔
(x ≠ 0 ∧ y ≠ 0 ∧ ∃ r : ℝ, 0 < r ∧ y = r • o.rotation θ x) ∨ θ = 0 ∧ (x = 0 ∨ y = 0) := by
by_cases hx : x = 0
· simp [hx, eq_comm]
· by_cases hy : y = 0
· simp [hy, eq_comm]
· rw [o.oangle_eq_iff_eq_pos_smul_rotation_of_ne_zero hx hy]
simp [hx, hy]
#align orientation.oangle_eq_iff_eq_pos_smul_rotation_or_eq_zero Orientation.oangle_eq_iff_eq_pos_smul_rotation_or_eq_zero
theorem exists_linearIsometryEquiv_eq_of_det_pos {f : V ≃ₗᵢ[ℝ] V}
(hd : 0 < LinearMap.det (f.toLinearEquiv : V →ₗ[ℝ] V)) :
∃ θ : Real.Angle, f = o.rotation θ := by
haveI : Nontrivial V :=
FiniteDimensional.nontrivial_of_finrank_eq_succ (@Fact.out (finrank ℝ V = 2) _)
obtain ⟨x, hx⟩ : ∃ x, x ≠ (0 : V) := exists_ne (0 : V)
use o.oangle x (f x)
apply LinearIsometryEquiv.toLinearEquiv_injective
apply LinearEquiv.toLinearMap_injective
apply (o.basisRightAngleRotation x hx).ext
intro i
symm
fin_cases i
· simp
have : o.oangle (J x) (f (J x)) = o.oangle x (f x) := by
simp only [oangle, o.linearIsometryEquiv_comp_rightAngleRotation f hd,
o.kahler_comp_rightAngleRotation]
simp [← this]
#align orientation.exists_linear_isometry_equiv_eq_of_det_pos Orientation.exists_linearIsometryEquiv_eq_of_det_pos
theorem rotation_map (θ : Real.Angle) (f : V ≃ₗᵢ[ℝ] V') (x : V') :
(Orientation.map (Fin 2) f.toLinearEquiv o).rotation θ x = f (o.rotation θ (f.symm x)) := by
simp [rotation_apply, o.rightAngleRotation_map]
#align orientation.rotation_map Orientation.rotation_map
@[simp]
protected theorem _root_.Complex.rotation (θ : Real.Angle) (z : ℂ) :
Complex.orientation.rotation θ z = θ.expMapCircle * z := by
simp only [rotation_apply, Complex.rightAngleRotation, Real.Angle.coe_expMapCircle, real_smul]
ring
#align complex.rotation Complex.rotation
theorem rotation_map_complex (θ : Real.Angle) (f : V ≃ₗᵢ[ℝ] ℂ)
(hf : Orientation.map (Fin 2) f.toLinearEquiv o = Complex.orientation) (x : V) :
f (o.rotation θ x) = θ.expMapCircle * f x := by
rw [← Complex.rotation, ← hf, o.rotation_map, LinearIsometryEquiv.symm_apply_apply]
#align orientation.rotation_map_complex Orientation.rotation_map_complex
theorem rotation_neg_orientation_eq_neg (θ : Real.Angle) : (-o).rotation θ = o.rotation (-θ) :=
LinearIsometryEquiv.ext <| by simp [rotation_apply]
#align orientation.rotation_neg_orientation_eq_neg Orientation.rotation_neg_orientation_eq_neg
@[simp]
theorem inner_rotation_pi_div_two_left (x : V) : ⟪o.rotation (π / 2 : ℝ) x, x⟫ = 0 := by
rw [rotation_pi_div_two, inner_rightAngleRotation_self]
#align orientation.inner_rotation_pi_div_two_left Orientation.inner_rotation_pi_div_two_left
@[simp]
theorem inner_rotation_pi_div_two_right (x : V) : ⟪x, o.rotation (π / 2 : ℝ) x⟫ = 0 := by
rw [real_inner_comm, inner_rotation_pi_div_two_left]
#align orientation.inner_rotation_pi_div_two_right Orientation.inner_rotation_pi_div_two_right
@[simp]
theorem inner_smul_rotation_pi_div_two_left (x : V) (r : ℝ) :
⟪r • o.rotation (π / 2 : ℝ) x, x⟫ = 0 := by
rw [inner_smul_left, inner_rotation_pi_div_two_left, mul_zero]
#align orientation.inner_smul_rotation_pi_div_two_left Orientation.inner_smul_rotation_pi_div_two_left
@[simp]
theorem inner_smul_rotation_pi_div_two_right (x : V) (r : ℝ) :
⟪x, r • o.rotation (π / 2 : ℝ) x⟫ = 0 := by
rw [real_inner_comm, inner_smul_rotation_pi_div_two_left]
#align orientation.inner_smul_rotation_pi_div_two_right Orientation.inner_smul_rotation_pi_div_two_right
@[simp]
theorem inner_rotation_pi_div_two_left_smul (x : V) (r : ℝ) :
⟪o.rotation (π / 2 : ℝ) x, r • x⟫ = 0 := by
rw [inner_smul_right, inner_rotation_pi_div_two_left, mul_zero]
#align orientation.inner_rotation_pi_div_two_left_smul Orientation.inner_rotation_pi_div_two_left_smul
@[simp]
theorem inner_rotation_pi_div_two_right_smul (x : V) (r : ℝ) :
⟪r • x, o.rotation (π / 2 : ℝ) x⟫ = 0 := by
rw [real_inner_comm, inner_rotation_pi_div_two_left_smul]
#align orientation.inner_rotation_pi_div_two_right_smul Orientation.inner_rotation_pi_div_two_right_smul
@[simp]
| Mathlib/Geometry/Euclidean/Angle/Oriented/Rotation.lean | 469 | 471 | theorem inner_smul_rotation_pi_div_two_smul_left (x : V) (r₁ r₂ : ℝ) :
⟪r₁ • o.rotation (π / 2 : ℝ) x, r₂ • x⟫ = 0 := by |
rw [inner_smul_right, inner_smul_rotation_pi_div_two_left, mul_zero]
|
import Mathlib.Order.Interval.Multiset
#align_import data.nat.interval from "leanprover-community/mathlib"@"1d29de43a5ba4662dd33b5cfeecfc2a27a5a8a29"
-- TODO
-- assert_not_exists Ring
open Finset Nat
variable (a b c : ℕ)
namespace Nat
instance instLocallyFiniteOrder : LocallyFiniteOrder ℕ where
finsetIcc a b := ⟨List.range' a (b + 1 - a), List.nodup_range' _ _⟩
finsetIco a b := ⟨List.range' a (b - a), List.nodup_range' _ _⟩
finsetIoc a b := ⟨List.range' (a + 1) (b - a), List.nodup_range' _ _⟩
finsetIoo a b := ⟨List.range' (a + 1) (b - a - 1), List.nodup_range' _ _⟩
finset_mem_Icc a b x := by rw [Finset.mem_mk, Multiset.mem_coe, List.mem_range'_1]; omega
finset_mem_Ico a b x := by rw [Finset.mem_mk, Multiset.mem_coe, List.mem_range'_1]; omega
finset_mem_Ioc a b x := by rw [Finset.mem_mk, Multiset.mem_coe, List.mem_range'_1]; omega
finset_mem_Ioo a b x := by rw [Finset.mem_mk, Multiset.mem_coe, List.mem_range'_1]; omega
theorem Icc_eq_range' : Icc a b = ⟨List.range' a (b + 1 - a), List.nodup_range' _ _⟩ :=
rfl
#align nat.Icc_eq_range' Nat.Icc_eq_range'
theorem Ico_eq_range' : Ico a b = ⟨List.range' a (b - a), List.nodup_range' _ _⟩ :=
rfl
#align nat.Ico_eq_range' Nat.Ico_eq_range'
theorem Ioc_eq_range' : Ioc a b = ⟨List.range' (a + 1) (b - a), List.nodup_range' _ _⟩ :=
rfl
#align nat.Ioc_eq_range' Nat.Ioc_eq_range'
theorem Ioo_eq_range' : Ioo a b = ⟨List.range' (a + 1) (b - a - 1), List.nodup_range' _ _⟩ :=
rfl
#align nat.Ioo_eq_range' Nat.Ioo_eq_range'
theorem uIcc_eq_range' :
uIcc a b = ⟨List.range' (min a b) (max a b + 1 - min a b), List.nodup_range' _ _⟩ := rfl
#align nat.uIcc_eq_range' Nat.uIcc_eq_range'
theorem Iio_eq_range : Iio = range := by
ext b x
rw [mem_Iio, mem_range]
#align nat.Iio_eq_range Nat.Iio_eq_range
@[simp]
theorem Ico_zero_eq_range : Ico 0 = range := by rw [← Nat.bot_eq_zero, ← Iio_eq_Ico, Iio_eq_range]
#align nat.Ico_zero_eq_range Nat.Ico_zero_eq_range
lemma range_eq_Icc_zero_sub_one (n : ℕ) (hn : n ≠ 0): range n = Icc 0 (n - 1) := by
ext b
simp_all only [mem_Icc, zero_le, true_and, mem_range]
exact lt_iff_le_pred (zero_lt_of_ne_zero hn)
theorem _root_.Finset.range_eq_Ico : range = Ico 0 :=
Ico_zero_eq_range.symm
#align finset.range_eq_Ico Finset.range_eq_Ico
@[simp]
theorem card_Icc : (Icc a b).card = b + 1 - a :=
List.length_range' _ _ _
#align nat.card_Icc Nat.card_Icc
@[simp]
theorem card_Ico : (Ico a b).card = b - a :=
List.length_range' _ _ _
#align nat.card_Ico Nat.card_Ico
@[simp]
theorem card_Ioc : (Ioc a b).card = b - a :=
List.length_range' _ _ _
#align nat.card_Ioc Nat.card_Ioc
@[simp]
theorem card_Ioo : (Ioo a b).card = b - a - 1 :=
List.length_range' _ _ _
#align nat.card_Ioo Nat.card_Ioo
@[simp]
theorem card_uIcc : (uIcc a b).card = (b - a : ℤ).natAbs + 1 :=
(card_Icc _ _).trans $ by rw [← Int.natCast_inj, sup_eq_max, inf_eq_min, Int.ofNat_sub] <;> omega
#align nat.card_uIcc Nat.card_uIcc
@[simp]
lemma card_Iic : (Iic b).card = b + 1 := by rw [Iic_eq_Icc, card_Icc, Nat.bot_eq_zero, Nat.sub_zero]
#align nat.card_Iic Nat.card_Iic
@[simp]
theorem card_Iio : (Iio b).card = b := by rw [Iio_eq_Ico, card_Ico, Nat.bot_eq_zero, Nat.sub_zero]
#align nat.card_Iio Nat.card_Iio
-- Porting note (#10618): simp can prove this
-- @[simp]
theorem card_fintypeIcc : Fintype.card (Set.Icc a b) = b + 1 - a := by
rw [Fintype.card_ofFinset, card_Icc]
#align nat.card_fintype_Icc Nat.card_fintypeIcc
-- Porting note (#10618): simp can prove this
-- @[simp]
theorem card_fintypeIco : Fintype.card (Set.Ico a b) = b - a := by
rw [Fintype.card_ofFinset, card_Ico]
#align nat.card_fintype_Ico Nat.card_fintypeIco
-- Porting note (#10618): simp can prove this
-- @[simp]
theorem card_fintypeIoc : Fintype.card (Set.Ioc a b) = b - a := by
rw [Fintype.card_ofFinset, card_Ioc]
#align nat.card_fintype_Ioc Nat.card_fintypeIoc
-- Porting note (#10618): simp can prove this
-- @[simp]
theorem card_fintypeIoo : Fintype.card (Set.Ioo a b) = b - a - 1 := by
rw [Fintype.card_ofFinset, card_Ioo]
#align nat.card_fintype_Ioo Nat.card_fintypeIoo
-- Porting note (#10618): simp can prove this
-- @[simp]
theorem card_fintypeIic : Fintype.card (Set.Iic b) = b + 1 := by
rw [Fintype.card_ofFinset, card_Iic]
#align nat.card_fintype_Iic Nat.card_fintypeIic
-- Porting note (#10618): simp can prove this
-- @[simp]
theorem card_fintypeIio : Fintype.card (Set.Iio b) = b := by rw [Fintype.card_ofFinset, card_Iio]
#align nat.card_fintype_Iio Nat.card_fintypeIio
-- TODO@Yaël: Generalize all the following lemmas to `SuccOrder`
theorem Icc_succ_left : Icc a.succ b = Ioc a b := by
ext x
rw [mem_Icc, mem_Ioc, succ_le_iff]
#align nat.Icc_succ_left Nat.Icc_succ_left
theorem Ico_succ_right : Ico a b.succ = Icc a b := by
ext x
rw [mem_Ico, mem_Icc, Nat.lt_succ_iff]
#align nat.Ico_succ_right Nat.Ico_succ_right
theorem Ico_succ_left : Ico a.succ b = Ioo a b := by
ext x
rw [mem_Ico, mem_Ioo, succ_le_iff]
#align nat.Ico_succ_left Nat.Ico_succ_left
theorem Icc_pred_right {b : ℕ} (h : 0 < b) : Icc a (b - 1) = Ico a b := by
ext x
rw [mem_Icc, mem_Ico, lt_iff_le_pred h]
#align nat.Icc_pred_right Nat.Icc_pred_right
theorem Ico_succ_succ : Ico a.succ b.succ = Ioc a b := by
ext x
rw [mem_Ico, mem_Ioc, succ_le_iff, Nat.lt_succ_iff]
#align nat.Ico_succ_succ Nat.Ico_succ_succ
@[simp]
theorem Ico_succ_singleton : Ico a (a + 1) = {a} := by rw [Ico_succ_right, Icc_self]
#align nat.Ico_succ_singleton Nat.Ico_succ_singleton
@[simp]
theorem Ico_pred_singleton {a : ℕ} (h : 0 < a) : Ico (a - 1) a = {a - 1} := by
rw [← Icc_pred_right _ h, Icc_self]
#align nat.Ico_pred_singleton Nat.Ico_pred_singleton
@[simp]
theorem Ioc_succ_singleton : Ioc b (b + 1) = {b + 1} := by rw [← Nat.Icc_succ_left, Icc_self]
#align nat.Ioc_succ_singleton Nat.Ioc_succ_singleton
variable {a b c}
theorem Ico_succ_right_eq_insert_Ico (h : a ≤ b) : Ico a (b + 1) = insert b (Ico a b) := by
rw [Ico_succ_right, ← Ico_insert_right h]
#align nat.Ico_succ_right_eq_insert_Ico Nat.Ico_succ_right_eq_insert_Ico
| Mathlib/Order/Interval/Finset/Nat.lean | 192 | 193 | theorem Ico_insert_succ_left (h : a < b) : insert a (Ico a.succ b) = Ico a b := by |
rw [Ico_succ_left, ← Ioo_insert_left h]
|
import Mathlib.Data.ENNReal.Operations
#align_import data.real.ennreal from "leanprover-community/mathlib"@"c14c8fcde993801fca8946b0d80131a1a81d1520"
open Set NNReal
namespace ENNReal
noncomputable section Inv
variable {a b c d : ℝ≥0∞} {r p q : ℝ≥0}
protected theorem div_eq_inv_mul : a / b = b⁻¹ * a := by rw [div_eq_mul_inv, mul_comm]
#align ennreal.div_eq_inv_mul ENNReal.div_eq_inv_mul
@[simp] theorem inv_zero : (0 : ℝ≥0∞)⁻¹ = ∞ :=
show sInf { b : ℝ≥0∞ | 1 ≤ 0 * b } = ∞ by simp
#align ennreal.inv_zero ENNReal.inv_zero
@[simp] theorem inv_top : ∞⁻¹ = 0 :=
bot_unique <| le_of_forall_le_of_dense fun a (h : 0 < a) => sInf_le <| by simp [*, h.ne', top_mul]
#align ennreal.inv_top ENNReal.inv_top
theorem coe_inv_le : (↑r⁻¹ : ℝ≥0∞) ≤ (↑r)⁻¹ :=
le_sInf fun b (hb : 1 ≤ ↑r * b) =>
coe_le_iff.2 <| by
rintro b rfl
apply NNReal.inv_le_of_le_mul
rwa [← coe_mul, ← coe_one, coe_le_coe] at hb
#align ennreal.coe_inv_le ENNReal.coe_inv_le
@[simp, norm_cast]
theorem coe_inv (hr : r ≠ 0) : (↑r⁻¹ : ℝ≥0∞) = (↑r)⁻¹ :=
coe_inv_le.antisymm <| sInf_le <| mem_setOf.2 <| by rw [← coe_mul, mul_inv_cancel hr, coe_one]
#align ennreal.coe_inv ENNReal.coe_inv
@[norm_cast]
theorem coe_inv_two : ((2⁻¹ : ℝ≥0) : ℝ≥0∞) = 2⁻¹ := by rw [coe_inv _root_.two_ne_zero, coe_two]
#align ennreal.coe_inv_two ENNReal.coe_inv_two
@[simp, norm_cast]
theorem coe_div (hr : r ≠ 0) : (↑(p / r) : ℝ≥0∞) = p / r := by
rw [div_eq_mul_inv, div_eq_mul_inv, coe_mul, coe_inv hr]
#align ennreal.coe_div ENNReal.coe_div
lemma coe_div_le : ↑(p / r) ≤ (p / r : ℝ≥0∞) := by
simpa only [div_eq_mul_inv, coe_mul] using mul_le_mul_left' coe_inv_le _
theorem div_zero (h : a ≠ 0) : a / 0 = ∞ := by simp [div_eq_mul_inv, h]
#align ennreal.div_zero ENNReal.div_zero
instance : DivInvOneMonoid ℝ≥0∞ :=
{ inferInstanceAs (DivInvMonoid ℝ≥0∞) with
inv_one := by simpa only [coe_inv one_ne_zero, coe_one] using coe_inj.2 inv_one }
protected theorem inv_pow : ∀ {a : ℝ≥0∞} {n : ℕ}, (a ^ n)⁻¹ = a⁻¹ ^ n
| _, 0 => by simp only [pow_zero, inv_one]
| ⊤, n + 1 => by simp [top_pow]
| (a : ℝ≥0), n + 1 => by
rcases eq_or_ne a 0 with (rfl | ha)
· simp [top_pow]
· have := pow_ne_zero (n + 1) ha
norm_cast
rw [inv_pow]
#align ennreal.inv_pow ENNReal.inv_pow
protected theorem mul_inv_cancel (h0 : a ≠ 0) (ht : a ≠ ∞) : a * a⁻¹ = 1 := by
lift a to ℝ≥0 using ht
norm_cast at h0; norm_cast
exact mul_inv_cancel h0
#align ennreal.mul_inv_cancel ENNReal.mul_inv_cancel
protected theorem inv_mul_cancel (h0 : a ≠ 0) (ht : a ≠ ∞) : a⁻¹ * a = 1 :=
mul_comm a a⁻¹ ▸ ENNReal.mul_inv_cancel h0 ht
#align ennreal.inv_mul_cancel ENNReal.inv_mul_cancel
protected theorem div_mul_cancel (h0 : a ≠ 0) (hI : a ≠ ∞) : b / a * a = b := by
rw [div_eq_mul_inv, mul_assoc, ENNReal.inv_mul_cancel h0 hI, mul_one]
#align ennreal.div_mul_cancel ENNReal.div_mul_cancel
protected theorem mul_div_cancel' (h0 : a ≠ 0) (hI : a ≠ ∞) : a * (b / a) = b := by
rw [mul_comm, ENNReal.div_mul_cancel h0 hI]
#align ennreal.mul_div_cancel' ENNReal.mul_div_cancel'
-- Porting note: `simp only [div_eq_mul_inv, mul_comm, mul_assoc]` doesn't work in the following two
protected theorem mul_comm_div : a / b * c = a * (c / b) := by
simp only [div_eq_mul_inv, mul_right_comm, ← mul_assoc]
#align ennreal.mul_comm_div ENNReal.mul_comm_div
protected theorem mul_div_right_comm : a * b / c = a / c * b := by
simp only [div_eq_mul_inv, mul_right_comm]
#align ennreal.mul_div_right_comm ENNReal.mul_div_right_comm
instance : InvolutiveInv ℝ≥0∞ where
inv_inv a := by
by_cases a = 0 <;> cases a <;> simp_all [none_eq_top, some_eq_coe, -coe_inv, (coe_inv _).symm]
@[simp] protected lemma inv_eq_one : a⁻¹ = 1 ↔ a = 1 := by rw [← inv_inj, inv_inv, inv_one]
@[simp] theorem inv_eq_top : a⁻¹ = ∞ ↔ a = 0 := inv_zero ▸ inv_inj
#align ennreal.inv_eq_top ENNReal.inv_eq_top
theorem inv_ne_top : a⁻¹ ≠ ∞ ↔ a ≠ 0 := by simp
#align ennreal.inv_ne_top ENNReal.inv_ne_top
@[simp]
theorem inv_lt_top {x : ℝ≥0∞} : x⁻¹ < ∞ ↔ 0 < x := by
simp only [lt_top_iff_ne_top, inv_ne_top, pos_iff_ne_zero]
#align ennreal.inv_lt_top ENNReal.inv_lt_top
theorem div_lt_top {x y : ℝ≥0∞} (h1 : x ≠ ∞) (h2 : y ≠ 0) : x / y < ∞ :=
mul_lt_top h1 (inv_ne_top.mpr h2)
#align ennreal.div_lt_top ENNReal.div_lt_top
@[simp]
protected theorem inv_eq_zero : a⁻¹ = 0 ↔ a = ∞ :=
inv_top ▸ inv_inj
#align ennreal.inv_eq_zero ENNReal.inv_eq_zero
protected theorem inv_ne_zero : a⁻¹ ≠ 0 ↔ a ≠ ∞ := by simp
#align ennreal.inv_ne_zero ENNReal.inv_ne_zero
protected theorem div_pos (ha : a ≠ 0) (hb : b ≠ ∞) : 0 < a / b :=
ENNReal.mul_pos ha <| ENNReal.inv_ne_zero.2 hb
#align ennreal.div_pos ENNReal.div_pos
protected theorem mul_inv {a b : ℝ≥0∞} (ha : a ≠ 0 ∨ b ≠ ∞) (hb : a ≠ ∞ ∨ b ≠ 0) :
(a * b)⁻¹ = a⁻¹ * b⁻¹ := by
induction' b with b
· replace ha : a ≠ 0 := ha.neg_resolve_right rfl
simp [ha]
induction' a with a
· replace hb : b ≠ 0 := coe_ne_zero.1 (hb.neg_resolve_left rfl)
simp [hb]
by_cases h'a : a = 0
· simp only [h'a, top_mul, ENNReal.inv_zero, ENNReal.coe_ne_top, zero_mul, Ne,
not_false_iff, ENNReal.coe_zero, ENNReal.inv_eq_zero]
by_cases h'b : b = 0
· simp only [h'b, ENNReal.inv_zero, ENNReal.coe_ne_top, mul_top, Ne, not_false_iff,
mul_zero, ENNReal.coe_zero, ENNReal.inv_eq_zero]
rw [← ENNReal.coe_mul, ← ENNReal.coe_inv, ← ENNReal.coe_inv h'a, ← ENNReal.coe_inv h'b, ←
ENNReal.coe_mul, mul_inv_rev, mul_comm]
simp [h'a, h'b]
#align ennreal.mul_inv ENNReal.mul_inv
protected theorem mul_div_mul_left (a b : ℝ≥0∞) (hc : c ≠ 0) (hc' : c ≠ ⊤) :
c * a / (c * b) = a / b := by
rw [div_eq_mul_inv, div_eq_mul_inv, ENNReal.mul_inv (Or.inl hc) (Or.inl hc'), mul_mul_mul_comm,
ENNReal.mul_inv_cancel hc hc', one_mul]
#align ennreal.mul_div_mul_left ENNReal.mul_div_mul_left
protected theorem mul_div_mul_right (a b : ℝ≥0∞) (hc : c ≠ 0) (hc' : c ≠ ⊤) :
a * c / (b * c) = a / b := by
rw [div_eq_mul_inv, div_eq_mul_inv, ENNReal.mul_inv (Or.inr hc') (Or.inr hc), mul_mul_mul_comm,
ENNReal.mul_inv_cancel hc hc', mul_one]
#align ennreal.mul_div_mul_right ENNReal.mul_div_mul_right
protected theorem sub_div (h : 0 < b → b < a → c ≠ 0) : (a - b) / c = a / c - b / c := by
simp_rw [div_eq_mul_inv]
exact ENNReal.sub_mul (by simpa using h)
#align ennreal.sub_div ENNReal.sub_div
@[simp]
protected theorem inv_pos : 0 < a⁻¹ ↔ a ≠ ∞ :=
pos_iff_ne_zero.trans ENNReal.inv_ne_zero
#align ennreal.inv_pos ENNReal.inv_pos
theorem inv_strictAnti : StrictAnti (Inv.inv : ℝ≥0∞ → ℝ≥0∞) := by
intro a b h
lift a to ℝ≥0 using h.ne_top
induction b; · simp
rw [coe_lt_coe] at h
rcases eq_or_ne a 0 with (rfl | ha); · simp [h]
rw [← coe_inv h.ne_bot, ← coe_inv ha, coe_lt_coe]
exact NNReal.inv_lt_inv ha h
#align ennreal.inv_strict_anti ENNReal.inv_strictAnti
@[simp]
protected theorem inv_lt_inv : a⁻¹ < b⁻¹ ↔ b < a :=
inv_strictAnti.lt_iff_lt
#align ennreal.inv_lt_inv ENNReal.inv_lt_inv
theorem inv_lt_iff_inv_lt : a⁻¹ < b ↔ b⁻¹ < a := by
simpa only [inv_inv] using @ENNReal.inv_lt_inv a b⁻¹
#align ennreal.inv_lt_iff_inv_lt ENNReal.inv_lt_iff_inv_lt
theorem lt_inv_iff_lt_inv : a < b⁻¹ ↔ b < a⁻¹ := by
simpa only [inv_inv] using @ENNReal.inv_lt_inv a⁻¹ b
#align ennreal.lt_inv_iff_lt_inv ENNReal.lt_inv_iff_lt_inv
@[simp]
protected theorem inv_le_inv : a⁻¹ ≤ b⁻¹ ↔ b ≤ a :=
inv_strictAnti.le_iff_le
#align ennreal.inv_le_inv ENNReal.inv_le_inv
theorem inv_le_iff_inv_le : a⁻¹ ≤ b ↔ b⁻¹ ≤ a := by
simpa only [inv_inv] using @ENNReal.inv_le_inv a b⁻¹
#align ennreal.inv_le_iff_inv_le ENNReal.inv_le_iff_inv_le
theorem le_inv_iff_le_inv : a ≤ b⁻¹ ↔ b ≤ a⁻¹ := by
simpa only [inv_inv] using @ENNReal.inv_le_inv a⁻¹ b
#align ennreal.le_inv_iff_le_inv ENNReal.le_inv_iff_le_inv
@[gcongr] protected theorem inv_le_inv' (h : a ≤ b) : b⁻¹ ≤ a⁻¹ :=
ENNReal.inv_strictAnti.antitone h
@[gcongr] protected theorem inv_lt_inv' (h : a < b) : b⁻¹ < a⁻¹ := ENNReal.inv_strictAnti h
@[simp]
protected theorem inv_le_one : a⁻¹ ≤ 1 ↔ 1 ≤ a := by rw [inv_le_iff_inv_le, inv_one]
#align ennreal.inv_le_one ENNReal.inv_le_one
protected theorem one_le_inv : 1 ≤ a⁻¹ ↔ a ≤ 1 := by rw [le_inv_iff_le_inv, inv_one]
#align ennreal.one_le_inv ENNReal.one_le_inv
@[simp]
protected theorem inv_lt_one : a⁻¹ < 1 ↔ 1 < a := by rw [inv_lt_iff_inv_lt, inv_one]
#align ennreal.inv_lt_one ENNReal.inv_lt_one
@[simp]
protected theorem one_lt_inv : 1 < a⁻¹ ↔ a < 1 := by rw [lt_inv_iff_lt_inv, inv_one]
#align ennreal.one_lt_inv ENNReal.one_lt_inv
@[simps! apply]
def _root_.OrderIso.invENNReal : ℝ≥0∞ ≃o ℝ≥0∞ᵒᵈ where
map_rel_iff' := ENNReal.inv_le_inv
toEquiv := (Equiv.inv ℝ≥0∞).trans OrderDual.toDual
#align order_iso.inv_ennreal OrderIso.invENNReal
#align order_iso.inv_ennreal_apply OrderIso.invENNReal_apply
@[simp]
theorem _root_.OrderIso.invENNReal_symm_apply (a : ℝ≥0∞ᵒᵈ) :
OrderIso.invENNReal.symm a = (OrderDual.ofDual a)⁻¹ :=
rfl
#align order_iso.inv_ennreal_symm_apply OrderIso.invENNReal_symm_apply
@[simp] theorem div_top : a / ∞ = 0 := by rw [div_eq_mul_inv, inv_top, mul_zero]
#align ennreal.div_top ENNReal.div_top
-- Porting note: reordered 4 lemmas
theorem top_div : ∞ / a = if a = ∞ then 0 else ∞ := by simp [div_eq_mul_inv, top_mul']
#align ennreal.top_div ENNReal.top_div
theorem top_div_of_ne_top (h : a ≠ ∞) : ∞ / a = ∞ := by simp [top_div, h]
#align ennreal.top_div_of_ne_top ENNReal.top_div_of_ne_top
@[simp] theorem top_div_coe : ∞ / p = ∞ := top_div_of_ne_top coe_ne_top
#align ennreal.top_div_coe ENNReal.top_div_coe
theorem top_div_of_lt_top (h : a < ∞) : ∞ / a = ∞ := top_div_of_ne_top h.ne
#align ennreal.top_div_of_lt_top ENNReal.top_div_of_lt_top
@[simp] protected theorem zero_div : 0 / a = 0 := zero_mul a⁻¹
#align ennreal.zero_div ENNReal.zero_div
theorem div_eq_top : a / b = ∞ ↔ a ≠ 0 ∧ b = 0 ∨ a = ∞ ∧ b ≠ ∞ := by
simp [div_eq_mul_inv, ENNReal.mul_eq_top]
#align ennreal.div_eq_top ENNReal.div_eq_top
protected theorem le_div_iff_mul_le (h0 : b ≠ 0 ∨ c ≠ 0) (ht : b ≠ ∞ ∨ c ≠ ∞) :
a ≤ c / b ↔ a * b ≤ c := by
induction' b with b
· lift c to ℝ≥0 using ht.neg_resolve_left rfl
rw [div_top, nonpos_iff_eq_zero]
rcases eq_or_ne a 0 with (rfl | ha) <;> simp [*]
rcases eq_or_ne b 0 with (rfl | hb)
· have hc : c ≠ 0 := h0.neg_resolve_left rfl
simp [div_zero hc]
· rw [← coe_ne_zero] at hb
rw [← ENNReal.mul_le_mul_right hb coe_ne_top, ENNReal.div_mul_cancel hb coe_ne_top]
#align ennreal.le_div_iff_mul_le ENNReal.le_div_iff_mul_le
protected theorem div_le_iff_le_mul (hb0 : b ≠ 0 ∨ c ≠ ∞) (hbt : b ≠ ∞ ∨ c ≠ 0) :
a / b ≤ c ↔ a ≤ c * b := by
suffices a * b⁻¹ ≤ c ↔ a ≤ c / b⁻¹ by simpa [div_eq_mul_inv]
refine (ENNReal.le_div_iff_mul_le ?_ ?_).symm <;> simpa
#align ennreal.div_le_iff_le_mul ENNReal.div_le_iff_le_mul
protected theorem lt_div_iff_mul_lt (hb0 : b ≠ 0 ∨ c ≠ ∞) (hbt : b ≠ ∞ ∨ c ≠ 0) :
c < a / b ↔ c * b < a :=
lt_iff_lt_of_le_iff_le (ENNReal.div_le_iff_le_mul hb0 hbt)
#align ennreal.lt_div_iff_mul_lt ENNReal.lt_div_iff_mul_lt
theorem div_le_of_le_mul (h : a ≤ b * c) : a / c ≤ b := by
by_cases h0 : c = 0
· have : a = 0 := by simpa [h0] using h
simp [*]
by_cases hinf : c = ∞; · simp [hinf]
exact (ENNReal.div_le_iff_le_mul (Or.inl h0) (Or.inl hinf)).2 h
#align ennreal.div_le_of_le_mul ENNReal.div_le_of_le_mul
theorem div_le_of_le_mul' (h : a ≤ b * c) : a / b ≤ c :=
div_le_of_le_mul <| mul_comm b c ▸ h
#align ennreal.div_le_of_le_mul' ENNReal.div_le_of_le_mul'
protected theorem div_self_le_one : a / a ≤ 1 := div_le_of_le_mul <| by rw [one_mul]
theorem mul_le_of_le_div (h : a ≤ b / c) : a * c ≤ b := by
rw [← inv_inv c]
exact div_le_of_le_mul h
#align ennreal.mul_le_of_le_div ENNReal.mul_le_of_le_div
theorem mul_le_of_le_div' (h : a ≤ b / c) : c * a ≤ b :=
mul_comm a c ▸ mul_le_of_le_div h
#align ennreal.mul_le_of_le_div' ENNReal.mul_le_of_le_div'
protected theorem div_lt_iff (h0 : b ≠ 0 ∨ c ≠ 0) (ht : b ≠ ∞ ∨ c ≠ ∞) : c / b < a ↔ c < a * b :=
lt_iff_lt_of_le_iff_le <| ENNReal.le_div_iff_mul_le h0 ht
#align ennreal.div_lt_iff ENNReal.div_lt_iff
theorem mul_lt_of_lt_div (h : a < b / c) : a * c < b := by
contrapose! h
exact ENNReal.div_le_of_le_mul h
#align ennreal.mul_lt_of_lt_div ENNReal.mul_lt_of_lt_div
theorem mul_lt_of_lt_div' (h : a < b / c) : c * a < b :=
mul_comm a c ▸ mul_lt_of_lt_div h
#align ennreal.mul_lt_of_lt_div' ENNReal.mul_lt_of_lt_div'
theorem div_lt_of_lt_mul (h : a < b * c) : a / c < b :=
mul_lt_of_lt_div <| by rwa [div_eq_mul_inv, inv_inv]
theorem div_lt_of_lt_mul' (h : a < b * c) : a / b < c :=
div_lt_of_lt_mul <| by rwa [mul_comm]
theorem inv_le_iff_le_mul (h₁ : b = ∞ → a ≠ 0) (h₂ : a = ∞ → b ≠ 0) : a⁻¹ ≤ b ↔ 1 ≤ a * b := by
rw [← one_div, ENNReal.div_le_iff_le_mul, mul_comm]
exacts [or_not_of_imp h₁, not_or_of_imp h₂]
#align ennreal.inv_le_iff_le_mul ENNReal.inv_le_iff_le_mul
@[simp 900]
theorem le_inv_iff_mul_le : a ≤ b⁻¹ ↔ a * b ≤ 1 := by
rw [← one_div, ENNReal.le_div_iff_mul_le] <;>
· right
simp
#align ennreal.le_inv_iff_mul_le ENNReal.le_inv_iff_mul_le
@[gcongr] protected theorem div_le_div (hab : a ≤ b) (hdc : d ≤ c) : a / c ≤ b / d :=
div_eq_mul_inv b d ▸ div_eq_mul_inv a c ▸ mul_le_mul' hab (ENNReal.inv_le_inv.mpr hdc)
#align ennreal.div_le_div ENNReal.div_le_div
@[gcongr] protected theorem div_le_div_left (h : a ≤ b) (c : ℝ≥0∞) : c / b ≤ c / a :=
ENNReal.div_le_div le_rfl h
#align ennreal.div_le_div_left ENNReal.div_le_div_left
@[gcongr] protected theorem div_le_div_right (h : a ≤ b) (c : ℝ≥0∞) : a / c ≤ b / c :=
ENNReal.div_le_div h le_rfl
#align ennreal.div_le_div_right ENNReal.div_le_div_right
protected theorem eq_inv_of_mul_eq_one_left (h : a * b = 1) : a = b⁻¹ := by
rw [← mul_one a, ← ENNReal.mul_inv_cancel (right_ne_zero_of_mul_eq_one h), ← mul_assoc, h,
one_mul]
rintro rfl
simp [left_ne_zero_of_mul_eq_one h] at h
#align ennreal.eq_inv_of_mul_eq_one_left ENNReal.eq_inv_of_mul_eq_one_left
theorem mul_le_iff_le_inv {a b r : ℝ≥0∞} (hr₀ : r ≠ 0) (hr₁ : r ≠ ∞) : r * a ≤ b ↔ a ≤ r⁻¹ * b := by
rw [← @ENNReal.mul_le_mul_left _ a _ hr₀ hr₁, ← mul_assoc, ENNReal.mul_inv_cancel hr₀ hr₁,
one_mul]
#align ennreal.mul_le_iff_le_inv ENNReal.mul_le_iff_le_inv
instance : PosSMulStrictMono ℝ≥0 ℝ≥0∞ where
elim _r hr _a _b hab := ENNReal.mul_lt_mul_left' (coe_pos.2 hr).ne' coe_ne_top hab
instance : SMulPosMono ℝ≥0 ℝ≥0∞ where
elim _r _ _a _b hab := mul_le_mul_right' (coe_le_coe.2 hab) _
#align ennreal.le_inv_smul_iff_of_pos le_inv_smul_iff_of_pos
#align ennreal.inv_smul_le_iff_of_pos inv_smul_le_iff_of_pos
theorem le_of_forall_nnreal_lt {x y : ℝ≥0∞} (h : ∀ r : ℝ≥0, ↑r < x → ↑r ≤ y) : x ≤ y := by
refine le_of_forall_ge_of_dense fun r hr => ?_
lift r to ℝ≥0 using ne_top_of_lt hr
exact h r hr
#align ennreal.le_of_forall_nnreal_lt ENNReal.le_of_forall_nnreal_lt
theorem le_of_forall_pos_nnreal_lt {x y : ℝ≥0∞} (h : ∀ r : ℝ≥0, 0 < r → ↑r < x → ↑r ≤ y) : x ≤ y :=
le_of_forall_nnreal_lt fun r hr =>
(zero_le r).eq_or_lt.elim (fun h => h ▸ zero_le _) fun h0 => h r h0 hr
#align ennreal.le_of_forall_pos_nnreal_lt ENNReal.le_of_forall_pos_nnreal_lt
theorem eq_top_of_forall_nnreal_le {x : ℝ≥0∞} (h : ∀ r : ℝ≥0, ↑r ≤ x) : x = ∞ :=
top_unique <| le_of_forall_nnreal_lt fun r _ => h r
#align ennreal.eq_top_of_forall_nnreal_le ENNReal.eq_top_of_forall_nnreal_le
protected theorem add_div : (a + b) / c = a / c + b / c :=
right_distrib a b c⁻¹
#align ennreal.add_div ENNReal.add_div
protected theorem div_add_div_same {a b c : ℝ≥0∞} : a / c + b / c = (a + b) / c :=
ENNReal.add_div.symm
#align ennreal.div_add_div_same ENNReal.div_add_div_same
protected theorem div_self (h0 : a ≠ 0) (hI : a ≠ ∞) : a / a = 1 :=
ENNReal.mul_inv_cancel h0 hI
#align ennreal.div_self ENNReal.div_self
theorem mul_div_le : a * (b / a) ≤ b :=
mul_le_of_le_div' le_rfl
#align ennreal.mul_div_le ENNReal.mul_div_le
theorem eq_div_iff (ha : a ≠ 0) (ha' : a ≠ ∞) : b = c / a ↔ a * b = c :=
⟨fun h => by rw [h, ENNReal.mul_div_cancel' ha ha'], fun h => by
rw [← h, mul_div_assoc, ENNReal.mul_div_cancel' ha ha']⟩
#align ennreal.eq_div_iff ENNReal.eq_div_iff
protected theorem div_eq_div_iff (ha : a ≠ 0) (ha' : a ≠ ∞) (hb : b ≠ 0) (hb' : b ≠ ∞) :
c / b = d / a ↔ a * c = b * d := by
rw [eq_div_iff ha ha']
conv_rhs => rw [eq_comm]
rw [← eq_div_iff hb hb', mul_div_assoc, eq_comm]
#align ennreal.div_eq_div_iff ENNReal.div_eq_div_iff
theorem div_eq_one_iff {a b : ℝ≥0∞} (hb₀ : b ≠ 0) (hb₁ : b ≠ ∞) : a / b = 1 ↔ a = b :=
⟨fun h => by rw [← (eq_div_iff hb₀ hb₁).mp h.symm, mul_one], fun h =>
h.symm ▸ ENNReal.div_self hb₀ hb₁⟩
#align ennreal.div_eq_one_iff ENNReal.div_eq_one_iff
| Mathlib/Data/ENNReal/Inv.lean | 451 | 452 | theorem inv_two_add_inv_two : (2 : ℝ≥0∞)⁻¹ + 2⁻¹ = 1 := by |
rw [← two_mul, ← div_eq_mul_inv, ENNReal.div_self two_ne_zero two_ne_top]
|
import Mathlib.Algebra.BigOperators.Ring
import Mathlib.Data.Fintype.BigOperators
import Mathlib.Data.Fintype.Fin
import Mathlib.GroupTheory.GroupAction.Pi
import Mathlib.Logic.Equiv.Fin
#align_import algebra.big_operators.fin from "leanprover-community/mathlib"@"cc5dd6244981976cc9da7afc4eee5682b037a013"
open Finset
variable {α : Type*} {β : Type*}
namespace Fin
@[to_additive]
theorem prod_ofFn [CommMonoid β] {n : ℕ} (f : Fin n → β) : (List.ofFn f).prod = ∏ i, f i := by
simp [prod_eq_multiset_prod]
#align fin.prod_of_fn Fin.prod_ofFn
#align fin.sum_of_fn Fin.sum_ofFn
@[to_additive]
theorem prod_univ_def [CommMonoid β] {n : ℕ} (f : Fin n → β) :
∏ i, f i = ((List.finRange n).map f).prod := by
rw [← List.ofFn_eq_map, prod_ofFn]
#align fin.prod_univ_def Fin.prod_univ_def
#align fin.sum_univ_def Fin.sum_univ_def
@[to_additive "A sum of a function `f : Fin 0 → β` is `0` because `Fin 0` is empty"]
theorem prod_univ_zero [CommMonoid β] (f : Fin 0 → β) : ∏ i, f i = 1 :=
rfl
#align fin.prod_univ_zero Fin.prod_univ_zero
#align fin.sum_univ_zero Fin.sum_univ_zero
@[to_additive "A sum of a function `f : Fin (n + 1) → β` over all `Fin (n + 1)` is the sum of
`f x`, for some `x : Fin (n + 1)` plus the remaining product"]
theorem prod_univ_succAbove [CommMonoid β] {n : ℕ} (f : Fin (n + 1) → β) (x : Fin (n + 1)) :
∏ i, f i = f x * ∏ i : Fin n, f (x.succAbove i) := by
rw [univ_succAbove, prod_cons, Finset.prod_map _ x.succAboveEmb]
rfl
#align fin.prod_univ_succ_above Fin.prod_univ_succAbove
#align fin.sum_univ_succ_above Fin.sum_univ_succAbove
@[to_additive "A sum of a function `f : Fin (n + 1) → β` over all `Fin (n + 1)` is the sum of
`f 0` plus the remaining product"]
theorem prod_univ_succ [CommMonoid β] {n : ℕ} (f : Fin (n + 1) → β) :
∏ i, f i = f 0 * ∏ i : Fin n, f i.succ :=
prod_univ_succAbove f 0
#align fin.prod_univ_succ Fin.prod_univ_succ
#align fin.sum_univ_succ Fin.sum_univ_succ
@[to_additive "A sum of a function `f : Fin (n + 1) → β` over all `Fin (n + 1)` is the sum of
`f (Fin.last n)` plus the remaining sum"]
theorem prod_univ_castSucc [CommMonoid β] {n : ℕ} (f : Fin (n + 1) → β) :
∏ i, f i = (∏ i : Fin n, f (Fin.castSucc i)) * f (last n) := by
simpa [mul_comm] using prod_univ_succAbove f (last n)
#align fin.prod_univ_cast_succ Fin.prod_univ_castSucc
#align fin.sum_univ_cast_succ Fin.sum_univ_castSucc
@[to_additive (attr := simp)]
theorem prod_univ_get [CommMonoid α] (l : List α) : ∏ i, l.get i = l.prod := by
simp [Finset.prod_eq_multiset_prod]
@[to_additive (attr := simp)]
theorem prod_univ_get' [CommMonoid β] (l : List α) (f : α → β) :
∏ i, f (l.get i) = (l.map f).prod := by
simp [Finset.prod_eq_multiset_prod]
@[to_additive]
theorem prod_cons [CommMonoid β] {n : ℕ} (x : β) (f : Fin n → β) :
(∏ i : Fin n.succ, (cons x f : Fin n.succ → β) i) = x * ∏ i : Fin n, f i := by
simp_rw [prod_univ_succ, cons_zero, cons_succ]
#align fin.prod_cons Fin.prod_cons
#align fin.sum_cons Fin.sum_cons
@[to_additive sum_univ_one]
theorem prod_univ_one [CommMonoid β] (f : Fin 1 → β) : ∏ i, f i = f 0 := by simp
#align fin.prod_univ_one Fin.prod_univ_one
#align fin.sum_univ_one Fin.sum_univ_one
@[to_additive (attr := simp)]
theorem prod_univ_two [CommMonoid β] (f : Fin 2 → β) : ∏ i, f i = f 0 * f 1 := by
simp [prod_univ_succ]
#align fin.prod_univ_two Fin.prod_univ_two
#align fin.sum_univ_two Fin.sum_univ_two
@[to_additive]
theorem prod_univ_two' [CommMonoid β] (f : α → β) (a b : α) :
∏ i, f (![a, b] i) = f a * f b :=
prod_univ_two _
@[to_additive]
theorem prod_univ_three [CommMonoid β] (f : Fin 3 → β) : ∏ i, f i = f 0 * f 1 * f 2 := by
rw [prod_univ_castSucc, prod_univ_two]
rfl
#align fin.prod_univ_three Fin.prod_univ_three
#align fin.sum_univ_three Fin.sum_univ_three
@[to_additive]
theorem prod_univ_four [CommMonoid β] (f : Fin 4 → β) : ∏ i, f i = f 0 * f 1 * f 2 * f 3 := by
rw [prod_univ_castSucc, prod_univ_three]
rfl
#align fin.prod_univ_four Fin.prod_univ_four
#align fin.sum_univ_four Fin.sum_univ_four
@[to_additive]
theorem prod_univ_five [CommMonoid β] (f : Fin 5 → β) :
∏ i, f i = f 0 * f 1 * f 2 * f 3 * f 4 := by
rw [prod_univ_castSucc, prod_univ_four]
rfl
#align fin.prod_univ_five Fin.prod_univ_five
#align fin.sum_univ_five Fin.sum_univ_five
@[to_additive]
theorem prod_univ_six [CommMonoid β] (f : Fin 6 → β) :
∏ i, f i = f 0 * f 1 * f 2 * f 3 * f 4 * f 5 := by
rw [prod_univ_castSucc, prod_univ_five]
rfl
#align fin.prod_univ_six Fin.prod_univ_six
#align fin.sum_univ_six Fin.sum_univ_six
@[to_additive]
theorem prod_univ_seven [CommMonoid β] (f : Fin 7 → β) :
∏ i, f i = f 0 * f 1 * f 2 * f 3 * f 4 * f 5 * f 6 := by
rw [prod_univ_castSucc, prod_univ_six]
rfl
#align fin.prod_univ_seven Fin.prod_univ_seven
#align fin.sum_univ_seven Fin.sum_univ_seven
@[to_additive]
theorem prod_univ_eight [CommMonoid β] (f : Fin 8 → β) :
∏ i, f i = f 0 * f 1 * f 2 * f 3 * f 4 * f 5 * f 6 * f 7 := by
rw [prod_univ_castSucc, prod_univ_seven]
rfl
#align fin.prod_univ_eight Fin.prod_univ_eight
#align fin.sum_univ_eight Fin.sum_univ_eight
theorem sum_pow_mul_eq_add_pow {n : ℕ} {R : Type*} [CommSemiring R] (a b : R) :
(∑ s : Finset (Fin n), a ^ s.card * b ^ (n - s.card)) = (a + b) ^ n := by
simpa using Fintype.sum_pow_mul_eq_add_pow (Fin n) a b
#align fin.sum_pow_mul_eq_add_pow Fin.sum_pow_mul_eq_add_pow
theorem prod_const [CommMonoid α] (n : ℕ) (x : α) : ∏ _i : Fin n, x = x ^ n := by simp
#align fin.prod_const Fin.prod_const
theorem sum_const [AddCommMonoid α] (n : ℕ) (x : α) : ∑ _i : Fin n, x = n • x := by simp
#align fin.sum_const Fin.sum_const
@[to_additive]
theorem prod_Ioi_zero {M : Type*} [CommMonoid M] {n : ℕ} {v : Fin n.succ → M} :
∏ i ∈ Ioi 0, v i = ∏ j : Fin n, v j.succ := by
rw [Ioi_zero_eq_map, Finset.prod_map, val_succEmb]
#align fin.prod_Ioi_zero Fin.prod_Ioi_zero
#align fin.sum_Ioi_zero Fin.sum_Ioi_zero
@[to_additive]
theorem prod_Ioi_succ {M : Type*} [CommMonoid M] {n : ℕ} (i : Fin n) (v : Fin n.succ → M) :
∏ j ∈ Ioi i.succ, v j = ∏ j ∈ Ioi i, v j.succ := by
rw [Ioi_succ, Finset.prod_map, val_succEmb]
#align fin.prod_Ioi_succ Fin.prod_Ioi_succ
#align fin.sum_Ioi_succ Fin.sum_Ioi_succ
@[to_additive]
theorem prod_congr' {M : Type*} [CommMonoid M] {a b : ℕ} (f : Fin b → M) (h : a = b) :
(∏ i : Fin a, f (cast h i)) = ∏ i : Fin b, f i := by
subst h
congr
#align fin.prod_congr' Fin.prod_congr'
#align fin.sum_congr' Fin.sum_congr'
@[to_additive]
theorem prod_univ_add {M : Type*} [CommMonoid M] {a b : ℕ} (f : Fin (a + b) → M) :
(∏ i : Fin (a + b), f i) = (∏ i : Fin a, f (castAdd b i)) * ∏ i : Fin b, f (natAdd a i) := by
rw [Fintype.prod_equiv finSumFinEquiv.symm f fun i => f (finSumFinEquiv.toFun i)]
· apply Fintype.prod_sum_type
· intro x
simp only [Equiv.toFun_as_coe, Equiv.apply_symm_apply]
#align fin.prod_univ_add Fin.prod_univ_add
#align fin.sum_univ_add Fin.sum_univ_add
@[to_additive]
theorem prod_trunc {M : Type*} [CommMonoid M] {a b : ℕ} (f : Fin (a + b) → M)
(hf : ∀ j : Fin b, f (natAdd a j) = 1) :
(∏ i : Fin (a + b), f i) = ∏ i : Fin a, f (castLE (Nat.le.intro rfl) i) := by
rw [prod_univ_add, Fintype.prod_eq_one _ hf, mul_one]
rfl
#align fin.prod_trunc Fin.prod_trunc
#align fin.sum_trunc Fin.sum_trunc
section PartialProd
variable [Monoid α] {n : ℕ}
@[to_additive "For `f = (a₁, ..., aₙ)` in `αⁿ`, `partialSum f` is\n
`(0, a₁, a₁ + a₂, ..., a₁ + ... + aₙ)` in `αⁿ⁺¹`."]
def partialProd (f : Fin n → α) (i : Fin (n + 1)) : α :=
((List.ofFn f).take i).prod
#align fin.partial_prod Fin.partialProd
#align fin.partial_sum Fin.partialSum
@[to_additive (attr := simp)]
theorem partialProd_zero (f : Fin n → α) : partialProd f 0 = 1 := by simp [partialProd]
#align fin.partial_prod_zero Fin.partialProd_zero
#align fin.partial_sum_zero Fin.partialSum_zero
@[to_additive]
| Mathlib/Algebra/BigOperators/Fin.lean | 244 | 246 | theorem partialProd_succ (f : Fin n → α) (j : Fin n) :
partialProd f j.succ = partialProd f (Fin.castSucc j) * f j := by |
simp [partialProd, List.take_succ, List.ofFnNthVal, dif_pos j.is_lt]
|
import Mathlib.Algebra.ModEq
import Mathlib.Algebra.Module.Defs
import Mathlib.Algebra.Order.Archimedean
import Mathlib.Algebra.Periodic
import Mathlib.Data.Int.SuccPred
import Mathlib.GroupTheory.QuotientGroup
import Mathlib.Order.Circular
import Mathlib.Data.List.TFAE
import Mathlib.Data.Set.Lattice
#align_import algebra.order.to_interval_mod from "leanprover-community/mathlib"@"213b0cff7bc5ab6696ee07cceec80829ce42efec"
noncomputable section
section LinearOrderedAddCommGroup
variable {α : Type*} [LinearOrderedAddCommGroup α] [hα : Archimedean α] {p : α} (hp : 0 < p)
{a b c : α} {n : ℤ}
def toIcoDiv (a b : α) : ℤ :=
(existsUnique_sub_zsmul_mem_Ico hp b a).choose
#align to_Ico_div toIcoDiv
theorem sub_toIcoDiv_zsmul_mem_Ico (a b : α) : b - toIcoDiv hp a b • p ∈ Set.Ico a (a + p) :=
(existsUnique_sub_zsmul_mem_Ico hp b a).choose_spec.1
#align sub_to_Ico_div_zsmul_mem_Ico sub_toIcoDiv_zsmul_mem_Ico
theorem toIcoDiv_eq_of_sub_zsmul_mem_Ico (h : b - n • p ∈ Set.Ico a (a + p)) :
toIcoDiv hp a b = n :=
((existsUnique_sub_zsmul_mem_Ico hp b a).choose_spec.2 _ h).symm
#align to_Ico_div_eq_of_sub_zsmul_mem_Ico toIcoDiv_eq_of_sub_zsmul_mem_Ico
def toIocDiv (a b : α) : ℤ :=
(existsUnique_sub_zsmul_mem_Ioc hp b a).choose
#align to_Ioc_div toIocDiv
theorem sub_toIocDiv_zsmul_mem_Ioc (a b : α) : b - toIocDiv hp a b • p ∈ Set.Ioc a (a + p) :=
(existsUnique_sub_zsmul_mem_Ioc hp b a).choose_spec.1
#align sub_to_Ioc_div_zsmul_mem_Ioc sub_toIocDiv_zsmul_mem_Ioc
theorem toIocDiv_eq_of_sub_zsmul_mem_Ioc (h : b - n • p ∈ Set.Ioc a (a + p)) :
toIocDiv hp a b = n :=
((existsUnique_sub_zsmul_mem_Ioc hp b a).choose_spec.2 _ h).symm
#align to_Ioc_div_eq_of_sub_zsmul_mem_Ioc toIocDiv_eq_of_sub_zsmul_mem_Ioc
def toIcoMod (a b : α) : α :=
b - toIcoDiv hp a b • p
#align to_Ico_mod toIcoMod
def toIocMod (a b : α) : α :=
b - toIocDiv hp a b • p
#align to_Ioc_mod toIocMod
theorem toIcoMod_mem_Ico (a b : α) : toIcoMod hp a b ∈ Set.Ico a (a + p) :=
sub_toIcoDiv_zsmul_mem_Ico hp a b
#align to_Ico_mod_mem_Ico toIcoMod_mem_Ico
theorem toIcoMod_mem_Ico' (b : α) : toIcoMod hp 0 b ∈ Set.Ico 0 p := by
convert toIcoMod_mem_Ico hp 0 b
exact (zero_add p).symm
#align to_Ico_mod_mem_Ico' toIcoMod_mem_Ico'
theorem toIocMod_mem_Ioc (a b : α) : toIocMod hp a b ∈ Set.Ioc a (a + p) :=
sub_toIocDiv_zsmul_mem_Ioc hp a b
#align to_Ioc_mod_mem_Ioc toIocMod_mem_Ioc
theorem left_le_toIcoMod (a b : α) : a ≤ toIcoMod hp a b :=
(Set.mem_Ico.1 (toIcoMod_mem_Ico hp a b)).1
#align left_le_to_Ico_mod left_le_toIcoMod
theorem left_lt_toIocMod (a b : α) : a < toIocMod hp a b :=
(Set.mem_Ioc.1 (toIocMod_mem_Ioc hp a b)).1
#align left_lt_to_Ioc_mod left_lt_toIocMod
theorem toIcoMod_lt_right (a b : α) : toIcoMod hp a b < a + p :=
(Set.mem_Ico.1 (toIcoMod_mem_Ico hp a b)).2
#align to_Ico_mod_lt_right toIcoMod_lt_right
theorem toIocMod_le_right (a b : α) : toIocMod hp a b ≤ a + p :=
(Set.mem_Ioc.1 (toIocMod_mem_Ioc hp a b)).2
#align to_Ioc_mod_le_right toIocMod_le_right
@[simp]
theorem self_sub_toIcoDiv_zsmul (a b : α) : b - toIcoDiv hp a b • p = toIcoMod hp a b :=
rfl
#align self_sub_to_Ico_div_zsmul self_sub_toIcoDiv_zsmul
@[simp]
theorem self_sub_toIocDiv_zsmul (a b : α) : b - toIocDiv hp a b • p = toIocMod hp a b :=
rfl
#align self_sub_to_Ioc_div_zsmul self_sub_toIocDiv_zsmul
@[simp]
theorem toIcoDiv_zsmul_sub_self (a b : α) : toIcoDiv hp a b • p - b = -toIcoMod hp a b := by
rw [toIcoMod, neg_sub]
#align to_Ico_div_zsmul_sub_self toIcoDiv_zsmul_sub_self
@[simp]
theorem toIocDiv_zsmul_sub_self (a b : α) : toIocDiv hp a b • p - b = -toIocMod hp a b := by
rw [toIocMod, neg_sub]
#align to_Ioc_div_zsmul_sub_self toIocDiv_zsmul_sub_self
@[simp]
theorem toIcoMod_sub_self (a b : α) : toIcoMod hp a b - b = -toIcoDiv hp a b • p := by
rw [toIcoMod, sub_sub_cancel_left, neg_smul]
#align to_Ico_mod_sub_self toIcoMod_sub_self
@[simp]
theorem toIocMod_sub_self (a b : α) : toIocMod hp a b - b = -toIocDiv hp a b • p := by
rw [toIocMod, sub_sub_cancel_left, neg_smul]
#align to_Ioc_mod_sub_self toIocMod_sub_self
@[simp]
| Mathlib/Algebra/Order/ToIntervalMod.lean | 143 | 144 | theorem self_sub_toIcoMod (a b : α) : b - toIcoMod hp a b = toIcoDiv hp a b • p := by |
rw [toIcoMod, sub_sub_cancel]
|
import Mathlib.Analysis.Calculus.FormalMultilinearSeries
import Mathlib.Analysis.SpecificLimits.Normed
import Mathlib.Logic.Equiv.Fin
import Mathlib.Topology.Algebra.InfiniteSum.Module
#align_import analysis.analytic.basic from "leanprover-community/mathlib"@"32253a1a1071173b33dc7d6a218cf722c6feb514"
noncomputable section
variable {𝕜 E F G : Type*}
open scoped Classical
open Topology NNReal Filter ENNReal
open Set Filter Asymptotics
variable [NontriviallyNormedField 𝕜] [NormedAddCommGroup E] [NormedSpace 𝕜 E] [NormedAddCommGroup F]
[NormedSpace 𝕜 F] [NormedAddCommGroup G] [NormedSpace 𝕜 G]
namespace FormalMultilinearSeries
variable (p : FormalMultilinearSeries 𝕜 E F) {r : ℝ≥0}
def radius (p : FormalMultilinearSeries 𝕜 E F) : ℝ≥0∞ :=
⨆ (r : ℝ≥0) (C : ℝ) (_ : ∀ n, ‖p n‖ * (r : ℝ) ^ n ≤ C), (r : ℝ≥0∞)
#align formal_multilinear_series.radius FormalMultilinearSeries.radius
theorem le_radius_of_bound (C : ℝ) {r : ℝ≥0} (h : ∀ n : ℕ, ‖p n‖ * (r : ℝ) ^ n ≤ C) :
(r : ℝ≥0∞) ≤ p.radius :=
le_iSup_of_le r <| le_iSup_of_le C <| le_iSup (fun _ => (r : ℝ≥0∞)) h
#align formal_multilinear_series.le_radius_of_bound FormalMultilinearSeries.le_radius_of_bound
theorem le_radius_of_bound_nnreal (C : ℝ≥0) {r : ℝ≥0} (h : ∀ n : ℕ, ‖p n‖₊ * r ^ n ≤ C) :
(r : ℝ≥0∞) ≤ p.radius :=
p.le_radius_of_bound C fun n => mod_cast h n
#align formal_multilinear_series.le_radius_of_bound_nnreal FormalMultilinearSeries.le_radius_of_bound_nnreal
theorem le_radius_of_isBigO (h : (fun n => ‖p n‖ * (r : ℝ) ^ n) =O[atTop] fun _ => (1 : ℝ)) :
↑r ≤ p.radius :=
Exists.elim (isBigO_one_nat_atTop_iff.1 h) fun C hC =>
p.le_radius_of_bound C fun n => (le_abs_self _).trans (hC n)
set_option linter.uppercaseLean3 false in
#align formal_multilinear_series.le_radius_of_is_O FormalMultilinearSeries.le_radius_of_isBigO
theorem le_radius_of_eventually_le (C) (h : ∀ᶠ n in atTop, ‖p n‖ * (r : ℝ) ^ n ≤ C) :
↑r ≤ p.radius :=
p.le_radius_of_isBigO <| IsBigO.of_bound C <| h.mono fun n hn => by simpa
#align formal_multilinear_series.le_radius_of_eventually_le FormalMultilinearSeries.le_radius_of_eventually_le
theorem le_radius_of_summable_nnnorm (h : Summable fun n => ‖p n‖₊ * r ^ n) : ↑r ≤ p.radius :=
p.le_radius_of_bound_nnreal (∑' n, ‖p n‖₊ * r ^ n) fun _ => le_tsum' h _
#align formal_multilinear_series.le_radius_of_summable_nnnorm FormalMultilinearSeries.le_radius_of_summable_nnnorm
theorem le_radius_of_summable (h : Summable fun n => ‖p n‖ * (r : ℝ) ^ n) : ↑r ≤ p.radius :=
p.le_radius_of_summable_nnnorm <| by
simp only [← coe_nnnorm] at h
exact mod_cast h
#align formal_multilinear_series.le_radius_of_summable FormalMultilinearSeries.le_radius_of_summable
theorem radius_eq_top_of_forall_nnreal_isBigO
(h : ∀ r : ℝ≥0, (fun n => ‖p n‖ * (r : ℝ) ^ n) =O[atTop] fun _ => (1 : ℝ)) : p.radius = ∞ :=
ENNReal.eq_top_of_forall_nnreal_le fun r => p.le_radius_of_isBigO (h r)
set_option linter.uppercaseLean3 false in
#align formal_multilinear_series.radius_eq_top_of_forall_nnreal_is_O FormalMultilinearSeries.radius_eq_top_of_forall_nnreal_isBigO
theorem radius_eq_top_of_eventually_eq_zero (h : ∀ᶠ n in atTop, p n = 0) : p.radius = ∞ :=
p.radius_eq_top_of_forall_nnreal_isBigO fun r =>
(isBigO_zero _ _).congr' (h.mono fun n hn => by simp [hn]) EventuallyEq.rfl
#align formal_multilinear_series.radius_eq_top_of_eventually_eq_zero FormalMultilinearSeries.radius_eq_top_of_eventually_eq_zero
theorem radius_eq_top_of_forall_image_add_eq_zero (n : ℕ) (hn : ∀ m, p (m + n) = 0) :
p.radius = ∞ :=
p.radius_eq_top_of_eventually_eq_zero <|
mem_atTop_sets.2 ⟨n, fun _ hk => tsub_add_cancel_of_le hk ▸ hn _⟩
#align formal_multilinear_series.radius_eq_top_of_forall_image_add_eq_zero FormalMultilinearSeries.radius_eq_top_of_forall_image_add_eq_zero
@[simp]
theorem constFormalMultilinearSeries_radius {v : F} :
(constFormalMultilinearSeries 𝕜 E v).radius = ⊤ :=
(constFormalMultilinearSeries 𝕜 E v).radius_eq_top_of_forall_image_add_eq_zero 1
(by simp [constFormalMultilinearSeries])
#align formal_multilinear_series.const_formal_multilinear_series_radius FormalMultilinearSeries.constFormalMultilinearSeries_radius
theorem isLittleO_of_lt_radius (h : ↑r < p.radius) :
∃ a ∈ Ioo (0 : ℝ) 1, (fun n => ‖p n‖ * (r : ℝ) ^ n) =o[atTop] (a ^ ·) := by
have := (TFAE_exists_lt_isLittleO_pow (fun n => ‖p n‖ * (r : ℝ) ^ n) 1).out 1 4
rw [this]
-- Porting note: was
-- rw [(TFAE_exists_lt_isLittleO_pow (fun n => ‖p n‖ * (r : ℝ) ^ n) 1).out 1 4]
simp only [radius, lt_iSup_iff] at h
rcases h with ⟨t, C, hC, rt⟩
rw [ENNReal.coe_lt_coe, ← NNReal.coe_lt_coe] at rt
have : 0 < (t : ℝ) := r.coe_nonneg.trans_lt rt
rw [← div_lt_one this] at rt
refine ⟨_, rt, C, Or.inr zero_lt_one, fun n => ?_⟩
calc
|‖p n‖ * (r : ℝ) ^ n| = ‖p n‖ * (t : ℝ) ^ n * (r / t : ℝ) ^ n := by
field_simp [mul_right_comm, abs_mul]
_ ≤ C * (r / t : ℝ) ^ n := by gcongr; apply hC
#align formal_multilinear_series.is_o_of_lt_radius FormalMultilinearSeries.isLittleO_of_lt_radius
theorem isLittleO_one_of_lt_radius (h : ↑r < p.radius) :
(fun n => ‖p n‖ * (r : ℝ) ^ n) =o[atTop] (fun _ => 1 : ℕ → ℝ) :=
let ⟨_, ha, hp⟩ := p.isLittleO_of_lt_radius h
hp.trans <| (isLittleO_pow_pow_of_lt_left ha.1.le ha.2).congr (fun _ => rfl) one_pow
#align formal_multilinear_series.is_o_one_of_lt_radius FormalMultilinearSeries.isLittleO_one_of_lt_radius
theorem norm_mul_pow_le_mul_pow_of_lt_radius (h : ↑r < p.radius) :
∃ a ∈ Ioo (0 : ℝ) 1, ∃ C > 0, ∀ n, ‖p n‖ * (r : ℝ) ^ n ≤ C * a ^ n := by
-- Porting note: moved out of `rcases`
have := ((TFAE_exists_lt_isLittleO_pow (fun n => ‖p n‖ * (r : ℝ) ^ n) 1).out 1 5).mp
(p.isLittleO_of_lt_radius h)
rcases this with ⟨a, ha, C, hC, H⟩
exact ⟨a, ha, C, hC, fun n => (le_abs_self _).trans (H n)⟩
#align formal_multilinear_series.norm_mul_pow_le_mul_pow_of_lt_radius FormalMultilinearSeries.norm_mul_pow_le_mul_pow_of_lt_radius
theorem lt_radius_of_isBigO (h₀ : r ≠ 0) {a : ℝ} (ha : a ∈ Ioo (-1 : ℝ) 1)
(hp : (fun n => ‖p n‖ * (r : ℝ) ^ n) =O[atTop] (a ^ ·)) : ↑r < p.radius := by
-- Porting note: moved out of `rcases`
have := ((TFAE_exists_lt_isLittleO_pow (fun n => ‖p n‖ * (r : ℝ) ^ n) 1).out 2 5)
rcases this.mp ⟨a, ha, hp⟩ with ⟨a, ha, C, hC, hp⟩
rw [← pos_iff_ne_zero, ← NNReal.coe_pos] at h₀
lift a to ℝ≥0 using ha.1.le
have : (r : ℝ) < r / a := by
simpa only [div_one] using (div_lt_div_left h₀ zero_lt_one ha.1).2 ha.2
norm_cast at this
rw [← ENNReal.coe_lt_coe] at this
refine this.trans_le (p.le_radius_of_bound C fun n => ?_)
rw [NNReal.coe_div, div_pow, ← mul_div_assoc, div_le_iff (pow_pos ha.1 n)]
exact (le_abs_self _).trans (hp n)
set_option linter.uppercaseLean3 false in
#align formal_multilinear_series.lt_radius_of_is_O FormalMultilinearSeries.lt_radius_of_isBigO
theorem norm_mul_pow_le_of_lt_radius (p : FormalMultilinearSeries 𝕜 E F) {r : ℝ≥0}
(h : (r : ℝ≥0∞) < p.radius) : ∃ C > 0, ∀ n, ‖p n‖ * (r : ℝ) ^ n ≤ C :=
let ⟨_, ha, C, hC, h⟩ := p.norm_mul_pow_le_mul_pow_of_lt_radius h
⟨C, hC, fun n => (h n).trans <| mul_le_of_le_one_right hC.lt.le (pow_le_one _ ha.1.le ha.2.le)⟩
#align formal_multilinear_series.norm_mul_pow_le_of_lt_radius FormalMultilinearSeries.norm_mul_pow_le_of_lt_radius
theorem norm_le_div_pow_of_pos_of_lt_radius (p : FormalMultilinearSeries 𝕜 E F) {r : ℝ≥0}
(h0 : 0 < r) (h : (r : ℝ≥0∞) < p.radius) : ∃ C > 0, ∀ n, ‖p n‖ ≤ C / (r : ℝ) ^ n :=
let ⟨C, hC, hp⟩ := p.norm_mul_pow_le_of_lt_radius h
⟨C, hC, fun n => Iff.mpr (le_div_iff (pow_pos h0 _)) (hp n)⟩
#align formal_multilinear_series.norm_le_div_pow_of_pos_of_lt_radius FormalMultilinearSeries.norm_le_div_pow_of_pos_of_lt_radius
theorem nnnorm_mul_pow_le_of_lt_radius (p : FormalMultilinearSeries 𝕜 E F) {r : ℝ≥0}
(h : (r : ℝ≥0∞) < p.radius) : ∃ C > 0, ∀ n, ‖p n‖₊ * r ^ n ≤ C :=
let ⟨C, hC, hp⟩ := p.norm_mul_pow_le_of_lt_radius h
⟨⟨C, hC.lt.le⟩, hC, mod_cast hp⟩
#align formal_multilinear_series.nnnorm_mul_pow_le_of_lt_radius FormalMultilinearSeries.nnnorm_mul_pow_le_of_lt_radius
theorem le_radius_of_tendsto (p : FormalMultilinearSeries 𝕜 E F) {l : ℝ}
(h : Tendsto (fun n => ‖p n‖ * (r : ℝ) ^ n) atTop (𝓝 l)) : ↑r ≤ p.radius :=
p.le_radius_of_isBigO (h.isBigO_one _)
#align formal_multilinear_series.le_radius_of_tendsto FormalMultilinearSeries.le_radius_of_tendsto
theorem le_radius_of_summable_norm (p : FormalMultilinearSeries 𝕜 E F)
(hs : Summable fun n => ‖p n‖ * (r : ℝ) ^ n) : ↑r ≤ p.radius :=
p.le_radius_of_tendsto hs.tendsto_atTop_zero
#align formal_multilinear_series.le_radius_of_summable_norm FormalMultilinearSeries.le_radius_of_summable_norm
theorem not_summable_norm_of_radius_lt_nnnorm (p : FormalMultilinearSeries 𝕜 E F) {x : E}
(h : p.radius < ‖x‖₊) : ¬Summable fun n => ‖p n‖ * ‖x‖ ^ n :=
fun hs => not_le_of_lt h (p.le_radius_of_summable_norm hs)
#align formal_multilinear_series.not_summable_norm_of_radius_lt_nnnorm FormalMultilinearSeries.not_summable_norm_of_radius_lt_nnnorm
theorem summable_norm_mul_pow (p : FormalMultilinearSeries 𝕜 E F) {r : ℝ≥0} (h : ↑r < p.radius) :
Summable fun n : ℕ => ‖p n‖ * (r : ℝ) ^ n := by
obtain ⟨a, ha : a ∈ Ioo (0 : ℝ) 1, C, - : 0 < C, hp⟩ := p.norm_mul_pow_le_mul_pow_of_lt_radius h
exact .of_nonneg_of_le (fun n => mul_nonneg (norm_nonneg _) (pow_nonneg r.coe_nonneg _))
hp ((summable_geometric_of_lt_one ha.1.le ha.2).mul_left _)
#align formal_multilinear_series.summable_norm_mul_pow FormalMultilinearSeries.summable_norm_mul_pow
theorem summable_norm_apply (p : FormalMultilinearSeries 𝕜 E F) {x : E}
(hx : x ∈ EMetric.ball (0 : E) p.radius) : Summable fun n : ℕ => ‖p n fun _ => x‖ := by
rw [mem_emetric_ball_zero_iff] at hx
refine .of_nonneg_of_le
(fun _ ↦ norm_nonneg _) (fun n ↦ ((p n).le_opNorm _).trans_eq ?_) (p.summable_norm_mul_pow hx)
simp
#align formal_multilinear_series.summable_norm_apply FormalMultilinearSeries.summable_norm_apply
theorem summable_nnnorm_mul_pow (p : FormalMultilinearSeries 𝕜 E F) {r : ℝ≥0} (h : ↑r < p.radius) :
Summable fun n : ℕ => ‖p n‖₊ * r ^ n := by
rw [← NNReal.summable_coe]
push_cast
exact p.summable_norm_mul_pow h
#align formal_multilinear_series.summable_nnnorm_mul_pow FormalMultilinearSeries.summable_nnnorm_mul_pow
protected theorem summable [CompleteSpace F] (p : FormalMultilinearSeries 𝕜 E F) {x : E}
(hx : x ∈ EMetric.ball (0 : E) p.radius) : Summable fun n : ℕ => p n fun _ => x :=
(p.summable_norm_apply hx).of_norm
#align formal_multilinear_series.summable FormalMultilinearSeries.summable
theorem radius_eq_top_of_summable_norm (p : FormalMultilinearSeries 𝕜 E F)
(hs : ∀ r : ℝ≥0, Summable fun n => ‖p n‖ * (r : ℝ) ^ n) : p.radius = ∞ :=
ENNReal.eq_top_of_forall_nnreal_le fun r => p.le_radius_of_summable_norm (hs r)
#align formal_multilinear_series.radius_eq_top_of_summable_norm FormalMultilinearSeries.radius_eq_top_of_summable_norm
theorem radius_eq_top_iff_summable_norm (p : FormalMultilinearSeries 𝕜 E F) :
p.radius = ∞ ↔ ∀ r : ℝ≥0, Summable fun n => ‖p n‖ * (r : ℝ) ^ n := by
constructor
· intro h r
obtain ⟨a, ha : a ∈ Ioo (0 : ℝ) 1, C, - : 0 < C, hp⟩ := p.norm_mul_pow_le_mul_pow_of_lt_radius
(show (r : ℝ≥0∞) < p.radius from h.symm ▸ ENNReal.coe_lt_top)
refine .of_norm_bounded
(fun n ↦ (C : ℝ) * a ^ n) ((summable_geometric_of_lt_one ha.1.le ha.2).mul_left _) fun n ↦ ?_
specialize hp n
rwa [Real.norm_of_nonneg (mul_nonneg (norm_nonneg _) (pow_nonneg r.coe_nonneg n))]
· exact p.radius_eq_top_of_summable_norm
#align formal_multilinear_series.radius_eq_top_iff_summable_norm FormalMultilinearSeries.radius_eq_top_iff_summable_norm
| Mathlib/Analysis/Analytic/Basic.lean | 323 | 331 | theorem le_mul_pow_of_radius_pos (p : FormalMultilinearSeries 𝕜 E F) (h : 0 < p.radius) :
∃ (C r : _) (hC : 0 < C) (_ : 0 < r), ∀ n, ‖p n‖ ≤ C * r ^ n := by |
rcases ENNReal.lt_iff_exists_nnreal_btwn.1 h with ⟨r, r0, rlt⟩
have rpos : 0 < (r : ℝ) := by simp [ENNReal.coe_pos.1 r0]
rcases norm_le_div_pow_of_pos_of_lt_radius p rpos rlt with ⟨C, Cpos, hCp⟩
refine ⟨C, r⁻¹, Cpos, by simp only [inv_pos, rpos], fun n => ?_⟩
-- Porting note: was `convert`
rw [inv_pow, ← div_eq_mul_inv]
exact hCp n
|
import Mathlib.CategoryTheory.ConcreteCategory.Basic
import Mathlib.CategoryTheory.Limits.Preserves.Basic
import Mathlib.CategoryTheory.Limits.TypesFiltered
import Mathlib.CategoryTheory.Limits.Yoneda
import Mathlib.Tactic.ApplyFun
#align_import category_theory.limits.concrete_category from "leanprover-community/mathlib"@"c3019c79074b0619edb4b27553a91b2e82242395"
universe t w v u r
open CategoryTheory
namespace CategoryTheory.Limits
attribute [local instance] ConcreteCategory.instFunLike ConcreteCategory.hasCoeToSort
section Colimits
section
variable {C : Type u} [Category.{v} C] [ConcreteCategory.{t} C] {J : Type w} [Category.{r} J]
(F : J ⥤ C) [PreservesColimit F (forget C)]
| Mathlib/CategoryTheory/Limits/ConcreteCategory.lean | 76 | 83 | theorem Concrete.from_union_surjective_of_isColimit {D : Cocone F} (hD : IsColimit D) :
let ff : (Σj : J, F.obj j) → D.pt := fun a => D.ι.app a.1 a.2
Function.Surjective ff := by |
intro ff x
let E : Cocone (F ⋙ forget C) := (forget C).mapCocone D
let hE : IsColimit E := isColimitOfPreserves (forget C) hD
obtain ⟨j, y, hy⟩ := Types.jointly_surjective_of_isColimit hE x
exact ⟨⟨j, y⟩, hy⟩
|
import Mathlib.Algebra.Module.BigOperators
import Mathlib.Data.Fintype.BigOperators
import Mathlib.LinearAlgebra.AffineSpace.AffineMap
import Mathlib.LinearAlgebra.AffineSpace.AffineSubspace
import Mathlib.LinearAlgebra.Finsupp
import Mathlib.Tactic.FinCases
#align_import linear_algebra.affine_space.combination from "leanprover-community/mathlib"@"2de9c37fa71dde2f1c6feff19876dd6a7b1519f0"
noncomputable section
open Affine
namespace Finset
theorem univ_fin2 : (univ : Finset (Fin 2)) = {0, 1} := by
ext x
fin_cases x <;> simp
#align finset.univ_fin2 Finset.univ_fin2
variable {k : Type*} {V : Type*} {P : Type*} [Ring k] [AddCommGroup V] [Module k V]
variable [S : AffineSpace V P]
variable {ι : Type*} (s : Finset ι)
variable {ι₂ : Type*} (s₂ : Finset ι₂)
def weightedVSubOfPoint (p : ι → P) (b : P) : (ι → k) →ₗ[k] V :=
∑ i ∈ s, (LinearMap.proj i : (ι → k) →ₗ[k] k).smulRight (p i -ᵥ b)
#align finset.weighted_vsub_of_point Finset.weightedVSubOfPoint
@[simp]
theorem weightedVSubOfPoint_apply (w : ι → k) (p : ι → P) (b : P) :
s.weightedVSubOfPoint p b w = ∑ i ∈ s, w i • (p i -ᵥ b) := by
simp [weightedVSubOfPoint, LinearMap.sum_apply]
#align finset.weighted_vsub_of_point_apply Finset.weightedVSubOfPoint_apply
@[simp (high)]
theorem weightedVSubOfPoint_apply_const (w : ι → k) (p : P) (b : P) :
s.weightedVSubOfPoint (fun _ => p) b w = (∑ i ∈ s, w i) • (p -ᵥ b) := by
rw [weightedVSubOfPoint_apply, sum_smul]
#align finset.weighted_vsub_of_point_apply_const Finset.weightedVSubOfPoint_apply_const
theorem weightedVSubOfPoint_congr {w₁ w₂ : ι → k} (hw : ∀ i ∈ s, w₁ i = w₂ i) {p₁ p₂ : ι → P}
(hp : ∀ i ∈ s, p₁ i = p₂ i) (b : P) :
s.weightedVSubOfPoint p₁ b w₁ = s.weightedVSubOfPoint p₂ b w₂ := by
simp_rw [weightedVSubOfPoint_apply]
refine sum_congr rfl fun i hi => ?_
rw [hw i hi, hp i hi]
#align finset.weighted_vsub_of_point_congr Finset.weightedVSubOfPoint_congr
theorem weightedVSubOfPoint_eq_of_weights_eq (p : ι → P) (j : ι) (w₁ w₂ : ι → k)
(hw : ∀ i, i ≠ j → w₁ i = w₂ i) :
s.weightedVSubOfPoint p (p j) w₁ = s.weightedVSubOfPoint p (p j) w₂ := by
simp only [Finset.weightedVSubOfPoint_apply]
congr
ext i
rcases eq_or_ne i j with h | h
· simp [h]
· simp [hw i h]
#align finset.weighted_vsub_of_point_eq_of_weights_eq Finset.weightedVSubOfPoint_eq_of_weights_eq
theorem weightedVSubOfPoint_eq_of_sum_eq_zero (w : ι → k) (p : ι → P) (h : ∑ i ∈ s, w i = 0)
(b₁ b₂ : P) : s.weightedVSubOfPoint p b₁ w = s.weightedVSubOfPoint p b₂ w := by
apply eq_of_sub_eq_zero
rw [weightedVSubOfPoint_apply, weightedVSubOfPoint_apply, ← sum_sub_distrib]
conv_lhs =>
congr
· skip
· ext
rw [← smul_sub, vsub_sub_vsub_cancel_left]
rw [← sum_smul, h, zero_smul]
#align finset.weighted_vsub_of_point_eq_of_sum_eq_zero Finset.weightedVSubOfPoint_eq_of_sum_eq_zero
theorem weightedVSubOfPoint_vadd_eq_of_sum_eq_one (w : ι → k) (p : ι → P) (h : ∑ i ∈ s, w i = 1)
(b₁ b₂ : P) : s.weightedVSubOfPoint p b₁ w +ᵥ b₁ = s.weightedVSubOfPoint p b₂ w +ᵥ b₂ := by
erw [weightedVSubOfPoint_apply, weightedVSubOfPoint_apply, ← @vsub_eq_zero_iff_eq V,
vadd_vsub_assoc, vsub_vadd_eq_vsub_sub, ← add_sub_assoc, add_comm, add_sub_assoc, ←
sum_sub_distrib]
conv_lhs =>
congr
· skip
· congr
· skip
· ext
rw [← smul_sub, vsub_sub_vsub_cancel_left]
rw [← sum_smul, h, one_smul, vsub_add_vsub_cancel, vsub_self]
#align finset.weighted_vsub_of_point_vadd_eq_of_sum_eq_one Finset.weightedVSubOfPoint_vadd_eq_of_sum_eq_one
@[simp (high)]
theorem weightedVSubOfPoint_erase [DecidableEq ι] (w : ι → k) (p : ι → P) (i : ι) :
(s.erase i).weightedVSubOfPoint p (p i) w = s.weightedVSubOfPoint p (p i) w := by
rw [weightedVSubOfPoint_apply, weightedVSubOfPoint_apply]
apply sum_erase
rw [vsub_self, smul_zero]
#align finset.weighted_vsub_of_point_erase Finset.weightedVSubOfPoint_erase
@[simp (high)]
theorem weightedVSubOfPoint_insert [DecidableEq ι] (w : ι → k) (p : ι → P) (i : ι) :
(insert i s).weightedVSubOfPoint p (p i) w = s.weightedVSubOfPoint p (p i) w := by
rw [weightedVSubOfPoint_apply, weightedVSubOfPoint_apply]
apply sum_insert_zero
rw [vsub_self, smul_zero]
#align finset.weighted_vsub_of_point_insert Finset.weightedVSubOfPoint_insert
theorem weightedVSubOfPoint_indicator_subset (w : ι → k) (p : ι → P) (b : P) {s₁ s₂ : Finset ι}
(h : s₁ ⊆ s₂) :
s₁.weightedVSubOfPoint p b w = s₂.weightedVSubOfPoint p b (Set.indicator (↑s₁) w) := by
rw [weightedVSubOfPoint_apply, weightedVSubOfPoint_apply]
exact Eq.symm <|
sum_indicator_subset_of_eq_zero w (fun i wi => wi • (p i -ᵥ b : V)) h fun i => zero_smul k _
#align finset.weighted_vsub_of_point_indicator_subset Finset.weightedVSubOfPoint_indicator_subset
theorem weightedVSubOfPoint_map (e : ι₂ ↪ ι) (w : ι → k) (p : ι → P) (b : P) :
(s₂.map e).weightedVSubOfPoint p b w = s₂.weightedVSubOfPoint (p ∘ e) b (w ∘ e) := by
simp_rw [weightedVSubOfPoint_apply]
exact Finset.sum_map _ _ _
#align finset.weighted_vsub_of_point_map Finset.weightedVSubOfPoint_map
theorem sum_smul_vsub_eq_weightedVSubOfPoint_sub (w : ι → k) (p₁ p₂ : ι → P) (b : P) :
(∑ i ∈ s, w i • (p₁ i -ᵥ p₂ i)) =
s.weightedVSubOfPoint p₁ b w - s.weightedVSubOfPoint p₂ b w := by
simp_rw [weightedVSubOfPoint_apply, ← sum_sub_distrib, ← smul_sub, vsub_sub_vsub_cancel_right]
#align finset.sum_smul_vsub_eq_weighted_vsub_of_point_sub Finset.sum_smul_vsub_eq_weightedVSubOfPoint_sub
theorem sum_smul_vsub_const_eq_weightedVSubOfPoint_sub (w : ι → k) (p₁ : ι → P) (p₂ b : P) :
(∑ i ∈ s, w i • (p₁ i -ᵥ p₂)) = s.weightedVSubOfPoint p₁ b w - (∑ i ∈ s, w i) • (p₂ -ᵥ b) := by
rw [sum_smul_vsub_eq_weightedVSubOfPoint_sub, weightedVSubOfPoint_apply_const]
#align finset.sum_smul_vsub_const_eq_weighted_vsub_of_point_sub Finset.sum_smul_vsub_const_eq_weightedVSubOfPoint_sub
theorem sum_smul_const_vsub_eq_sub_weightedVSubOfPoint (w : ι → k) (p₂ : ι → P) (p₁ b : P) :
(∑ i ∈ s, w i • (p₁ -ᵥ p₂ i)) = (∑ i ∈ s, w i) • (p₁ -ᵥ b) - s.weightedVSubOfPoint p₂ b w := by
rw [sum_smul_vsub_eq_weightedVSubOfPoint_sub, weightedVSubOfPoint_apply_const]
#align finset.sum_smul_const_vsub_eq_sub_weighted_vsub_of_point Finset.sum_smul_const_vsub_eq_sub_weightedVSubOfPoint
theorem weightedVSubOfPoint_sdiff [DecidableEq ι] {s₂ : Finset ι} (h : s₂ ⊆ s) (w : ι → k)
(p : ι → P) (b : P) :
(s \ s₂).weightedVSubOfPoint p b w + s₂.weightedVSubOfPoint p b w =
s.weightedVSubOfPoint p b w := by
simp_rw [weightedVSubOfPoint_apply, sum_sdiff h]
#align finset.weighted_vsub_of_point_sdiff Finset.weightedVSubOfPoint_sdiff
theorem weightedVSubOfPoint_sdiff_sub [DecidableEq ι] {s₂ : Finset ι} (h : s₂ ⊆ s) (w : ι → k)
(p : ι → P) (b : P) :
(s \ s₂).weightedVSubOfPoint p b w - s₂.weightedVSubOfPoint p b (-w) =
s.weightedVSubOfPoint p b w := by
rw [map_neg, sub_neg_eq_add, s.weightedVSubOfPoint_sdiff h]
#align finset.weighted_vsub_of_point_sdiff_sub Finset.weightedVSubOfPoint_sdiff_sub
theorem weightedVSubOfPoint_subtype_eq_filter (w : ι → k) (p : ι → P) (b : P) (pred : ι → Prop)
[DecidablePred pred] :
((s.subtype pred).weightedVSubOfPoint (fun i => p i) b fun i => w i) =
(s.filter pred).weightedVSubOfPoint p b w := by
rw [weightedVSubOfPoint_apply, weightedVSubOfPoint_apply, ← sum_subtype_eq_sum_filter]
#align finset.weighted_vsub_of_point_subtype_eq_filter Finset.weightedVSubOfPoint_subtype_eq_filter
theorem weightedVSubOfPoint_filter_of_ne (w : ι → k) (p : ι → P) (b : P) {pred : ι → Prop}
[DecidablePred pred] (h : ∀ i ∈ s, w i ≠ 0 → pred i) :
(s.filter pred).weightedVSubOfPoint p b w = s.weightedVSubOfPoint p b w := by
rw [weightedVSubOfPoint_apply, weightedVSubOfPoint_apply, sum_filter_of_ne]
intro i hi hne
refine h i hi ?_
intro hw
simp [hw] at hne
#align finset.weighted_vsub_of_point_filter_of_ne Finset.weightedVSubOfPoint_filter_of_ne
theorem weightedVSubOfPoint_const_smul (w : ι → k) (p : ι → P) (b : P) (c : k) :
s.weightedVSubOfPoint p b (c • w) = c • s.weightedVSubOfPoint p b w := by
simp_rw [weightedVSubOfPoint_apply, smul_sum, Pi.smul_apply, smul_smul, smul_eq_mul]
#align finset.weighted_vsub_of_point_const_smul Finset.weightedVSubOfPoint_const_smul
def weightedVSub (p : ι → P) : (ι → k) →ₗ[k] V :=
s.weightedVSubOfPoint p (Classical.choice S.nonempty)
#align finset.weighted_vsub Finset.weightedVSub
theorem weightedVSub_apply (w : ι → k) (p : ι → P) :
s.weightedVSub p w = ∑ i ∈ s, w i • (p i -ᵥ Classical.choice S.nonempty) := by
simp [weightedVSub, LinearMap.sum_apply]
#align finset.weighted_vsub_apply Finset.weightedVSub_apply
theorem weightedVSub_eq_weightedVSubOfPoint_of_sum_eq_zero (w : ι → k) (p : ι → P)
(h : ∑ i ∈ s, w i = 0) (b : P) : s.weightedVSub p w = s.weightedVSubOfPoint p b w :=
s.weightedVSubOfPoint_eq_of_sum_eq_zero w p h _ _
#align finset.weighted_vsub_eq_weighted_vsub_of_point_of_sum_eq_zero Finset.weightedVSub_eq_weightedVSubOfPoint_of_sum_eq_zero
@[simp]
theorem weightedVSub_apply_const (w : ι → k) (p : P) (h : ∑ i ∈ s, w i = 0) :
s.weightedVSub (fun _ => p) w = 0 := by
rw [weightedVSub, weightedVSubOfPoint_apply_const, h, zero_smul]
#align finset.weighted_vsub_apply_const Finset.weightedVSub_apply_const
@[simp]
theorem weightedVSub_empty (w : ι → k) (p : ι → P) : (∅ : Finset ι).weightedVSub p w = (0 : V) := by
simp [weightedVSub_apply]
#align finset.weighted_vsub_empty Finset.weightedVSub_empty
theorem weightedVSub_congr {w₁ w₂ : ι → k} (hw : ∀ i ∈ s, w₁ i = w₂ i) {p₁ p₂ : ι → P}
(hp : ∀ i ∈ s, p₁ i = p₂ i) : s.weightedVSub p₁ w₁ = s.weightedVSub p₂ w₂ :=
s.weightedVSubOfPoint_congr hw hp _
#align finset.weighted_vsub_congr Finset.weightedVSub_congr
theorem weightedVSub_indicator_subset (w : ι → k) (p : ι → P) {s₁ s₂ : Finset ι} (h : s₁ ⊆ s₂) :
s₁.weightedVSub p w = s₂.weightedVSub p (Set.indicator (↑s₁) w) :=
weightedVSubOfPoint_indicator_subset _ _ _ h
#align finset.weighted_vsub_indicator_subset Finset.weightedVSub_indicator_subset
theorem weightedVSub_map (e : ι₂ ↪ ι) (w : ι → k) (p : ι → P) :
(s₂.map e).weightedVSub p w = s₂.weightedVSub (p ∘ e) (w ∘ e) :=
s₂.weightedVSubOfPoint_map _ _ _ _
#align finset.weighted_vsub_map Finset.weightedVSub_map
theorem sum_smul_vsub_eq_weightedVSub_sub (w : ι → k) (p₁ p₂ : ι → P) :
(∑ i ∈ s, w i • (p₁ i -ᵥ p₂ i)) = s.weightedVSub p₁ w - s.weightedVSub p₂ w :=
s.sum_smul_vsub_eq_weightedVSubOfPoint_sub _ _ _ _
#align finset.sum_smul_vsub_eq_weighted_vsub_sub Finset.sum_smul_vsub_eq_weightedVSub_sub
theorem sum_smul_vsub_const_eq_weightedVSub (w : ι → k) (p₁ : ι → P) (p₂ : P)
(h : ∑ i ∈ s, w i = 0) : (∑ i ∈ s, w i • (p₁ i -ᵥ p₂)) = s.weightedVSub p₁ w := by
rw [sum_smul_vsub_eq_weightedVSub_sub, s.weightedVSub_apply_const _ _ h, sub_zero]
#align finset.sum_smul_vsub_const_eq_weighted_vsub Finset.sum_smul_vsub_const_eq_weightedVSub
theorem sum_smul_const_vsub_eq_neg_weightedVSub (w : ι → k) (p₂ : ι → P) (p₁ : P)
(h : ∑ i ∈ s, w i = 0) : (∑ i ∈ s, w i • (p₁ -ᵥ p₂ i)) = -s.weightedVSub p₂ w := by
rw [sum_smul_vsub_eq_weightedVSub_sub, s.weightedVSub_apply_const _ _ h, zero_sub]
#align finset.sum_smul_const_vsub_eq_neg_weighted_vsub Finset.sum_smul_const_vsub_eq_neg_weightedVSub
theorem weightedVSub_sdiff [DecidableEq ι] {s₂ : Finset ι} (h : s₂ ⊆ s) (w : ι → k) (p : ι → P) :
(s \ s₂).weightedVSub p w + s₂.weightedVSub p w = s.weightedVSub p w :=
s.weightedVSubOfPoint_sdiff h _ _ _
#align finset.weighted_vsub_sdiff Finset.weightedVSub_sdiff
theorem weightedVSub_sdiff_sub [DecidableEq ι] {s₂ : Finset ι} (h : s₂ ⊆ s) (w : ι → k)
(p : ι → P) : (s \ s₂).weightedVSub p w - s₂.weightedVSub p (-w) = s.weightedVSub p w :=
s.weightedVSubOfPoint_sdiff_sub h _ _ _
#align finset.weighted_vsub_sdiff_sub Finset.weightedVSub_sdiff_sub
theorem weightedVSub_subtype_eq_filter (w : ι → k) (p : ι → P) (pred : ι → Prop)
[DecidablePred pred] :
((s.subtype pred).weightedVSub (fun i => p i) fun i => w i) =
(s.filter pred).weightedVSub p w :=
s.weightedVSubOfPoint_subtype_eq_filter _ _ _ _
#align finset.weighted_vsub_subtype_eq_filter Finset.weightedVSub_subtype_eq_filter
theorem weightedVSub_filter_of_ne (w : ι → k) (p : ι → P) {pred : ι → Prop} [DecidablePred pred]
(h : ∀ i ∈ s, w i ≠ 0 → pred i) : (s.filter pred).weightedVSub p w = s.weightedVSub p w :=
s.weightedVSubOfPoint_filter_of_ne _ _ _ h
#align finset.weighted_vsub_filter_of_ne Finset.weightedVSub_filter_of_ne
theorem weightedVSub_const_smul (w : ι → k) (p : ι → P) (c : k) :
s.weightedVSub p (c • w) = c • s.weightedVSub p w :=
s.weightedVSubOfPoint_const_smul _ _ _ _
#align finset.weighted_vsub_const_smul Finset.weightedVSub_const_smul
instance : AffineSpace (ι → k) (ι → k) := Pi.instAddTorsor
variable (k)
def affineCombination (p : ι → P) : (ι → k) →ᵃ[k] P where
toFun w := s.weightedVSubOfPoint p (Classical.choice S.nonempty) w +ᵥ Classical.choice S.nonempty
linear := s.weightedVSub p
map_vadd' w₁ w₂ := by simp_rw [vadd_vadd, weightedVSub, vadd_eq_add, LinearMap.map_add]
#align finset.affine_combination Finset.affineCombination
@[simp]
theorem affineCombination_linear (p : ι → P) :
(s.affineCombination k p).linear = s.weightedVSub p :=
rfl
#align finset.affine_combination_linear Finset.affineCombination_linear
variable {k}
theorem affineCombination_apply (w : ι → k) (p : ι → P) :
(s.affineCombination k p) w =
s.weightedVSubOfPoint p (Classical.choice S.nonempty) w +ᵥ Classical.choice S.nonempty :=
rfl
#align finset.affine_combination_apply Finset.affineCombination_apply
@[simp]
theorem affineCombination_apply_const (w : ι → k) (p : P) (h : ∑ i ∈ s, w i = 1) :
s.affineCombination k (fun _ => p) w = p := by
rw [affineCombination_apply, s.weightedVSubOfPoint_apply_const, h, one_smul, vsub_vadd]
#align finset.affine_combination_apply_const Finset.affineCombination_apply_const
theorem affineCombination_congr {w₁ w₂ : ι → k} (hw : ∀ i ∈ s, w₁ i = w₂ i) {p₁ p₂ : ι → P}
(hp : ∀ i ∈ s, p₁ i = p₂ i) : s.affineCombination k p₁ w₁ = s.affineCombination k p₂ w₂ := by
simp_rw [affineCombination_apply, s.weightedVSubOfPoint_congr hw hp]
#align finset.affine_combination_congr Finset.affineCombination_congr
theorem affineCombination_eq_weightedVSubOfPoint_vadd_of_sum_eq_one (w : ι → k) (p : ι → P)
(h : ∑ i ∈ s, w i = 1) (b : P) :
s.affineCombination k p w = s.weightedVSubOfPoint p b w +ᵥ b :=
s.weightedVSubOfPoint_vadd_eq_of_sum_eq_one w p h _ _
#align finset.affine_combination_eq_weighted_vsub_of_point_vadd_of_sum_eq_one Finset.affineCombination_eq_weightedVSubOfPoint_vadd_of_sum_eq_one
theorem weightedVSub_vadd_affineCombination (w₁ w₂ : ι → k) (p : ι → P) :
s.weightedVSub p w₁ +ᵥ s.affineCombination k p w₂ = s.affineCombination k p (w₁ + w₂) := by
rw [← vadd_eq_add, AffineMap.map_vadd, affineCombination_linear]
#align finset.weighted_vsub_vadd_affine_combination Finset.weightedVSub_vadd_affineCombination
theorem affineCombination_vsub (w₁ w₂ : ι → k) (p : ι → P) :
s.affineCombination k p w₁ -ᵥ s.affineCombination k p w₂ = s.weightedVSub p (w₁ - w₂) := by
rw [← AffineMap.linearMap_vsub, affineCombination_linear, vsub_eq_sub]
#align finset.affine_combination_vsub Finset.affineCombination_vsub
theorem attach_affineCombination_of_injective [DecidableEq P] (s : Finset P) (w : P → k) (f : s → P)
(hf : Function.Injective f) :
s.attach.affineCombination k f (w ∘ f) = (image f univ).affineCombination k id w := by
simp only [affineCombination, weightedVSubOfPoint_apply, id, vadd_right_cancel_iff,
Function.comp_apply, AffineMap.coe_mk]
let g₁ : s → V := fun i => w (f i) • (f i -ᵥ Classical.choice S.nonempty)
let g₂ : P → V := fun i => w i • (i -ᵥ Classical.choice S.nonempty)
change univ.sum g₁ = (image f univ).sum g₂
have hgf : g₁ = g₂ ∘ f := by
ext
simp
rw [hgf, sum_image]
· simp only [Function.comp_apply]
· exact fun _ _ _ _ hxy => hf hxy
#align finset.attach_affine_combination_of_injective Finset.attach_affineCombination_of_injective
theorem attach_affineCombination_coe (s : Finset P) (w : P → k) :
s.attach.affineCombination k ((↑) : s → P) (w ∘ (↑)) = s.affineCombination k id w := by
classical rw [attach_affineCombination_of_injective s w ((↑) : s → P) Subtype.coe_injective,
univ_eq_attach, attach_image_val]
#align finset.attach_affine_combination_coe Finset.attach_affineCombination_coe
@[simp]
theorem weightedVSub_eq_linear_combination {ι} (s : Finset ι) {w : ι → k} {p : ι → V}
(hw : s.sum w = 0) : s.weightedVSub p w = ∑ i ∈ s, w i • p i := by
simp [s.weightedVSub_apply, vsub_eq_sub, smul_sub, ← Finset.sum_smul, hw]
#align finset.weighted_vsub_eq_linear_combination Finset.weightedVSub_eq_linear_combination
@[simp]
theorem affineCombination_eq_linear_combination (s : Finset ι) (p : ι → V) (w : ι → k)
(hw : ∑ i ∈ s, w i = 1) : s.affineCombination k p w = ∑ i ∈ s, w i • p i := by
simp [s.affineCombination_eq_weightedVSubOfPoint_vadd_of_sum_eq_one w p hw 0]
#align finset.affine_combination_eq_linear_combination Finset.affineCombination_eq_linear_combination
@[simp]
theorem affineCombination_of_eq_one_of_eq_zero (w : ι → k) (p : ι → P) {i : ι} (his : i ∈ s)
(hwi : w i = 1) (hw0 : ∀ i2 ∈ s, i2 ≠ i → w i2 = 0) : s.affineCombination k p w = p i := by
have h1 : ∑ i ∈ s, w i = 1 := hwi ▸ sum_eq_single i hw0 fun h => False.elim (h his)
rw [s.affineCombination_eq_weightedVSubOfPoint_vadd_of_sum_eq_one w p h1 (p i),
weightedVSubOfPoint_apply]
convert zero_vadd V (p i)
refine sum_eq_zero ?_
intro i2 hi2
by_cases h : i2 = i
· simp [h]
· simp [hw0 i2 hi2 h]
#align finset.affine_combination_of_eq_one_of_eq_zero Finset.affineCombination_of_eq_one_of_eq_zero
theorem affineCombination_indicator_subset (w : ι → k) (p : ι → P) {s₁ s₂ : Finset ι}
(h : s₁ ⊆ s₂) :
s₁.affineCombination k p w = s₂.affineCombination k p (Set.indicator (↑s₁) w) := by
rw [affineCombination_apply, affineCombination_apply,
weightedVSubOfPoint_indicator_subset _ _ _ h]
#align finset.affine_combination_indicator_subset Finset.affineCombination_indicator_subset
theorem affineCombination_map (e : ι₂ ↪ ι) (w : ι → k) (p : ι → P) :
(s₂.map e).affineCombination k p w = s₂.affineCombination k (p ∘ e) (w ∘ e) := by
simp_rw [affineCombination_apply, weightedVSubOfPoint_map]
#align finset.affine_combination_map Finset.affineCombination_map
theorem sum_smul_vsub_eq_affineCombination_vsub (w : ι → k) (p₁ p₂ : ι → P) :
(∑ i ∈ s, w i • (p₁ i -ᵥ p₂ i)) =
s.affineCombination k p₁ w -ᵥ s.affineCombination k p₂ w := by
simp_rw [affineCombination_apply, vadd_vsub_vadd_cancel_right]
exact s.sum_smul_vsub_eq_weightedVSubOfPoint_sub _ _ _ _
#align finset.sum_smul_vsub_eq_affine_combination_vsub Finset.sum_smul_vsub_eq_affineCombination_vsub
theorem sum_smul_vsub_const_eq_affineCombination_vsub (w : ι → k) (p₁ : ι → P) (p₂ : P)
(h : ∑ i ∈ s, w i = 1) : (∑ i ∈ s, w i • (p₁ i -ᵥ p₂)) = s.affineCombination k p₁ w -ᵥ p₂ := by
rw [sum_smul_vsub_eq_affineCombination_vsub, affineCombination_apply_const _ _ _ h]
#align finset.sum_smul_vsub_const_eq_affine_combination_vsub Finset.sum_smul_vsub_const_eq_affineCombination_vsub
theorem sum_smul_const_vsub_eq_vsub_affineCombination (w : ι → k) (p₂ : ι → P) (p₁ : P)
(h : ∑ i ∈ s, w i = 1) : (∑ i ∈ s, w i • (p₁ -ᵥ p₂ i)) = p₁ -ᵥ s.affineCombination k p₂ w := by
rw [sum_smul_vsub_eq_affineCombination_vsub, affineCombination_apply_const _ _ _ h]
#align finset.sum_smul_const_vsub_eq_vsub_affine_combination Finset.sum_smul_const_vsub_eq_vsub_affineCombination
theorem affineCombination_sdiff_sub [DecidableEq ι] {s₂ : Finset ι} (h : s₂ ⊆ s) (w : ι → k)
(p : ι → P) :
(s \ s₂).affineCombination k p w -ᵥ s₂.affineCombination k p (-w) = s.weightedVSub p w := by
simp_rw [affineCombination_apply, vadd_vsub_vadd_cancel_right]
exact s.weightedVSub_sdiff_sub h _ _
#align finset.affine_combination_sdiff_sub Finset.affineCombination_sdiff_sub
theorem affineCombination_eq_of_weightedVSub_eq_zero_of_eq_neg_one {w : ι → k} {p : ι → P}
(hw : s.weightedVSub p w = (0 : V)) {i : ι} [DecidablePred (· ≠ i)] (his : i ∈ s)
(hwi : w i = -1) : (s.filter (· ≠ i)).affineCombination k p w = p i := by
classical
rw [← @vsub_eq_zero_iff_eq V, ← hw,
← s.affineCombination_sdiff_sub (singleton_subset_iff.2 his), sdiff_singleton_eq_erase,
← filter_ne']
congr
refine (affineCombination_of_eq_one_of_eq_zero _ _ _ (mem_singleton_self _) ?_ ?_).symm
· simp [hwi]
· simp
#align finset.affine_combination_eq_of_weighted_vsub_eq_zero_of_eq_neg_one Finset.affineCombination_eq_of_weightedVSub_eq_zero_of_eq_neg_one
theorem affineCombination_subtype_eq_filter (w : ι → k) (p : ι → P) (pred : ι → Prop)
[DecidablePred pred] :
((s.subtype pred).affineCombination k (fun i => p i) fun i => w i) =
(s.filter pred).affineCombination k p w := by
rw [affineCombination_apply, affineCombination_apply, weightedVSubOfPoint_subtype_eq_filter]
#align finset.affine_combination_subtype_eq_filter Finset.affineCombination_subtype_eq_filter
theorem affineCombination_filter_of_ne (w : ι → k) (p : ι → P) {pred : ι → Prop}
[DecidablePred pred] (h : ∀ i ∈ s, w i ≠ 0 → pred i) :
(s.filter pred).affineCombination k p w = s.affineCombination k p w := by
rw [affineCombination_apply, affineCombination_apply,
s.weightedVSubOfPoint_filter_of_ne _ _ _ h]
#align finset.affine_combination_filter_of_ne Finset.affineCombination_filter_of_ne
theorem eq_weightedVSubOfPoint_subset_iff_eq_weightedVSubOfPoint_subtype {v : V} {x : k} {s : Set ι}
{p : ι → P} {b : P} :
(∃ fs : Finset ι, ↑fs ⊆ s ∧ ∃ w : ι → k, ∑ i ∈ fs, w i = x ∧
v = fs.weightedVSubOfPoint p b w) ↔
∃ (fs : Finset s) (w : s → k), ∑ i ∈ fs, w i = x ∧
v = fs.weightedVSubOfPoint (fun i : s => p i) b w := by
classical
simp_rw [weightedVSubOfPoint_apply]
constructor
· rintro ⟨fs, hfs, w, rfl, rfl⟩
exact ⟨fs.subtype s, fun i => w i, sum_subtype_of_mem _ hfs, (sum_subtype_of_mem _ hfs).symm⟩
· rintro ⟨fs, w, rfl, rfl⟩
refine
⟨fs.map (Function.Embedding.subtype _), map_subtype_subset _, fun i =>
if h : i ∈ s then w ⟨i, h⟩ else 0, ?_, ?_⟩ <;>
simp
#align finset.eq_weighted_vsub_of_point_subset_iff_eq_weighted_vsub_of_point_subtype Finset.eq_weightedVSubOfPoint_subset_iff_eq_weightedVSubOfPoint_subtype
variable (k)
theorem eq_weightedVSub_subset_iff_eq_weightedVSub_subtype {v : V} {s : Set ι} {p : ι → P} :
(∃ fs : Finset ι, ↑fs ⊆ s ∧ ∃ w : ι → k, ∑ i ∈ fs, w i = 0 ∧
v = fs.weightedVSub p w) ↔
∃ (fs : Finset s) (w : s → k), ∑ i ∈ fs, w i = 0 ∧
v = fs.weightedVSub (fun i : s => p i) w :=
eq_weightedVSubOfPoint_subset_iff_eq_weightedVSubOfPoint_subtype
#align finset.eq_weighted_vsub_subset_iff_eq_weighted_vsub_subtype Finset.eq_weightedVSub_subset_iff_eq_weightedVSub_subtype
variable (V)
theorem eq_affineCombination_subset_iff_eq_affineCombination_subtype {p0 : P} {s : Set ι}
{p : ι → P} :
(∃ fs : Finset ι, ↑fs ⊆ s ∧ ∃ w : ι → k, ∑ i ∈ fs, w i = 1 ∧
p0 = fs.affineCombination k p w) ↔
∃ (fs : Finset s) (w : s → k), ∑ i ∈ fs, w i = 1 ∧
p0 = fs.affineCombination k (fun i : s => p i) w := by
simp_rw [affineCombination_apply, eq_vadd_iff_vsub_eq]
exact eq_weightedVSubOfPoint_subset_iff_eq_weightedVSubOfPoint_subtype
#align finset.eq_affine_combination_subset_iff_eq_affine_combination_subtype Finset.eq_affineCombination_subset_iff_eq_affineCombination_subtype
variable {k V}
| Mathlib/LinearAlgebra/AffineSpace/Combination.lean | 628 | 637 | theorem map_affineCombination {V₂ P₂ : Type*} [AddCommGroup V₂] [Module k V₂] [AffineSpace V₂ P₂]
(p : ι → P) (w : ι → k) (hw : s.sum w = 1) (f : P →ᵃ[k] P₂) :
f (s.affineCombination k p w) = s.affineCombination k (f ∘ p) w := by |
have b := Classical.choice (inferInstance : AffineSpace V P).nonempty
have b₂ := Classical.choice (inferInstance : AffineSpace V₂ P₂).nonempty
rw [s.affineCombination_eq_weightedVSubOfPoint_vadd_of_sum_eq_one w p hw b,
s.affineCombination_eq_weightedVSubOfPoint_vadd_of_sum_eq_one w (f ∘ p) hw b₂, ←
s.weightedVSubOfPoint_vadd_eq_of_sum_eq_one w (f ∘ p) hw (f b) b₂]
simp only [weightedVSubOfPoint_apply, RingHom.id_apply, AffineMap.map_vadd,
LinearMap.map_smulₛₗ, AffineMap.linearMap_vsub, map_sum, Function.comp_apply]
|
import Mathlib.MeasureTheory.Covering.DensityTheorem
#align_import measure_theory.covering.liminf_limsup from "leanprover-community/mathlib"@"5f6e827d81dfbeb6151d7016586ceeb0099b9655"
open Set Filter Metric MeasureTheory TopologicalSpace
open scoped NNReal ENNReal Topology
variable {α : Type*} [MetricSpace α] [SecondCountableTopology α] [MeasurableSpace α] [BorelSpace α]
variable (μ : Measure α) [IsLocallyFiniteMeasure μ] [IsUnifLocDoublingMeasure μ]
theorem blimsup_cthickening_ae_le_of_eventually_mul_le_aux (p : ℕ → Prop) {s : ℕ → Set α}
(hs : ∀ i, IsClosed (s i)) {r₁ r₂ : ℕ → ℝ} (hr : Tendsto r₁ atTop (𝓝[>] 0)) (hrp : 0 ≤ r₁)
{M : ℝ} (hM : 0 < M) (hM' : M < 1) (hMr : ∀ᶠ i in atTop, M * r₁ i ≤ r₂ i) :
(blimsup (fun i => cthickening (r₁ i) (s i)) atTop p : Set α) ≤ᵐ[μ]
(blimsup (fun i => cthickening (r₂ i) (s i)) atTop p : Set α) := by
set Y₁ : ℕ → Set α := fun i => cthickening (r₁ i) (s i)
set Y₂ : ℕ → Set α := fun i => cthickening (r₂ i) (s i)
let Z : ℕ → Set α := fun i => ⋃ (j) (_ : p j ∧ i ≤ j), Y₂ j
suffices ∀ i, μ (atTop.blimsup Y₁ p \ Z i) = 0 by
rwa [ae_le_set, @blimsup_eq_iInf_biSup_of_nat _ _ _ Y₂, iInf_eq_iInter, diff_iInter,
measure_iUnion_null_iff]
intros i
set W := atTop.blimsup Y₁ p \ Z i
by_contra contra
obtain ⟨d, hd, hd'⟩ : ∃ d, d ∈ W ∧ ∀ {ι : Type _} {l : Filter ι} (w : ι → α) (δ : ι → ℝ),
Tendsto δ l (𝓝[>] 0) → (∀ᶠ j in l, d ∈ closedBall (w j) (2 * δ j)) →
Tendsto (fun j => μ (W ∩ closedBall (w j) (δ j)) / μ (closedBall (w j) (δ j))) l (𝓝 1) :=
Measure.exists_mem_of_measure_ne_zero_of_ae contra
(IsUnifLocDoublingMeasure.ae_tendsto_measure_inter_div μ W 2)
replace hd : d ∈ blimsup Y₁ atTop p := ((mem_diff _).mp hd).1
obtain ⟨f : ℕ → ℕ, hf⟩ := exists_forall_mem_of_hasBasis_mem_blimsup' atTop_basis hd
simp only [forall_and] at hf
obtain ⟨hf₀ : ∀ j, d ∈ cthickening (r₁ (f j)) (s (f j)), hf₁, hf₂ : ∀ j, j ≤ f j⟩ := hf
have hf₃ : Tendsto f atTop atTop :=
tendsto_atTop_atTop.mpr fun j => ⟨f j, fun i hi => (hf₂ j).trans (hi.trans <| hf₂ i)⟩
replace hr : Tendsto (r₁ ∘ f) atTop (𝓝[>] 0) := hr.comp hf₃
replace hMr : ∀ᶠ j in atTop, M * r₁ (f j) ≤ r₂ (f j) := hf₃.eventually hMr
replace hf₀ : ∀ j, ∃ w ∈ s (f j), d ∈ closedBall w (2 * r₁ (f j)) := by
intro j
specialize hrp (f j)
rw [Pi.zero_apply] at hrp
rcases eq_or_lt_of_le hrp with (hr0 | hrp')
· specialize hf₀ j
rw [← hr0, cthickening_zero, (hs (f j)).closure_eq] at hf₀
exact ⟨d, hf₀, by simp [← hr0]⟩
· simpa using mem_iUnion₂.mp (cthickening_subset_iUnion_closedBall_of_lt (s (f j))
(by positivity) (lt_two_mul_self hrp') (hf₀ j))
choose w hw hw' using hf₀
let C := IsUnifLocDoublingMeasure.scalingConstantOf μ M⁻¹
have hC : 0 < C :=
lt_of_lt_of_le zero_lt_one (IsUnifLocDoublingMeasure.one_le_scalingConstantOf μ M⁻¹)
suffices ∃ η < (1 : ℝ≥0),
∀ᶠ j in atTop, μ (W ∩ closedBall (w j) (r₁ (f j))) / μ (closedBall (w j) (r₁ (f j))) ≤ η by
obtain ⟨η, hη, hη'⟩ := this
replace hη' : 1 ≤ η := by
simpa only [ENNReal.one_le_coe_iff] using
le_of_tendsto (hd' w (fun j => r₁ (f j)) hr <| eventually_of_forall hw') hη'
exact (lt_self_iff_false _).mp (lt_of_lt_of_le hη hη')
refine ⟨1 - C⁻¹, tsub_lt_self zero_lt_one (inv_pos.mpr hC), ?_⟩
replace hC : C ≠ 0 := ne_of_gt hC
let b : ℕ → Set α := fun j => closedBall (w j) (M * r₁ (f j))
let B : ℕ → Set α := fun j => closedBall (w j) (r₁ (f j))
have h₁ : ∀ j, b j ⊆ B j := fun j =>
closedBall_subset_closedBall (mul_le_of_le_one_left (hrp (f j)) hM'.le)
have h₂ : ∀ j, W ∩ B j ⊆ B j := fun j => inter_subset_right
have h₃ : ∀ᶠ j in atTop, Disjoint (b j) (W ∩ B j) := by
apply hMr.mp
rw [eventually_atTop]
refine
⟨i, fun j hj hj' => Disjoint.inf_right (B j) <| Disjoint.inf_right' (blimsup Y₁ atTop p) ?_⟩
change Disjoint (b j) (Z i)ᶜ
rw [disjoint_compl_right_iff_subset]
refine (closedBall_subset_cthickening (hw j) (M * r₁ (f j))).trans
((cthickening_mono hj' _).trans fun a ha => ?_)
simp only [Z, mem_iUnion, exists_prop]
exact ⟨f j, ⟨hf₁ j, hj.le.trans (hf₂ j)⟩, ha⟩
have h₄ : ∀ᶠ j in atTop, μ (B j) ≤ C * μ (b j) :=
(hr.eventually (IsUnifLocDoublingMeasure.eventually_measure_le_scaling_constant_mul'
μ M hM)).mono fun j hj => hj (w j)
refine (h₃.and h₄).mono fun j hj₀ => ?_
change μ (W ∩ B j) / μ (B j) ≤ ↑(1 - C⁻¹)
rcases eq_or_ne (μ (B j)) ∞ with (hB | hB); · simp [hB]
apply ENNReal.div_le_of_le_mul
rw [ENNReal.coe_sub, ENNReal.coe_one, ENNReal.sub_mul fun _ _ => hB, one_mul]
replace hB : ↑C⁻¹ * μ (B j) ≠ ∞ := by
refine ENNReal.mul_ne_top ?_ hB
rwa [ENNReal.coe_inv hC, Ne, ENNReal.inv_eq_top, ENNReal.coe_eq_zero]
obtain ⟨hj₁ : Disjoint (b j) (W ∩ B j), hj₂ : μ (B j) ≤ C * μ (b j)⟩ := hj₀
replace hj₂ : ↑C⁻¹ * μ (B j) ≤ μ (b j) := by
rw [ENNReal.coe_inv hC, ← ENNReal.div_eq_inv_mul]
exact ENNReal.div_le_of_le_mul' hj₂
have hj₃ : ↑C⁻¹ * μ (B j) + μ (W ∩ B j) ≤ μ (B j) := by
refine le_trans (add_le_add_right hj₂ _) ?_
rw [← measure_union' hj₁ measurableSet_closedBall]
exact measure_mono (union_subset (h₁ j) (h₂ j))
replace hj₃ := tsub_le_tsub_right hj₃ (↑C⁻¹ * μ (B j))
rwa [ENNReal.add_sub_cancel_left hB] at hj₃
#align blimsup_cthickening_ae_le_of_eventually_mul_le_aux blimsup_cthickening_ae_le_of_eventually_mul_le_aux
theorem blimsup_cthickening_ae_le_of_eventually_mul_le (p : ℕ → Prop) {s : ℕ → Set α} {M : ℝ}
(hM : 0 < M) {r₁ r₂ : ℕ → ℝ} (hr : Tendsto r₁ atTop (𝓝[>] 0))
(hMr : ∀ᶠ i in atTop, M * r₁ i ≤ r₂ i) :
(blimsup (fun i => cthickening (r₁ i) (s i)) atTop p : Set α) ≤ᵐ[μ]
(blimsup (fun i => cthickening (r₂ i) (s i)) atTop p : Set α) := by
let R₁ i := max 0 (r₁ i)
let R₂ i := max 0 (r₂ i)
have hRp : 0 ≤ R₁ := fun i => le_max_left 0 (r₁ i)
replace hMr : ∀ᶠ i in atTop, M * R₁ i ≤ R₂ i := by
refine hMr.mono fun i hi ↦ ?_
rw [mul_max_of_nonneg _ _ hM.le, mul_zero]
exact max_le_max (le_refl 0) hi
simp_rw [← cthickening_max_zero (r₁ _), ← cthickening_max_zero (r₂ _)]
rcases le_or_lt 1 M with hM' | hM'
· apply HasSubset.Subset.eventuallyLE
change _ ≤ _
refine mono_blimsup' (hMr.mono fun i hi _ => cthickening_mono ?_ (s i))
exact (le_mul_of_one_le_left (hRp i) hM').trans hi
· simp only [← @cthickening_closure _ _ _ (s _)]
have hs : ∀ i, IsClosed (closure (s i)) := fun i => isClosed_closure
exact blimsup_cthickening_ae_le_of_eventually_mul_le_aux μ p hs
(tendsto_nhds_max_right hr) hRp hM hM' hMr
#align blimsup_cthickening_ae_le_of_eventually_mul_le blimsup_cthickening_ae_le_of_eventually_mul_le
theorem blimsup_cthickening_mul_ae_eq (p : ℕ → Prop) (s : ℕ → Set α) {M : ℝ} (hM : 0 < M)
(r : ℕ → ℝ) (hr : Tendsto r atTop (𝓝 0)) :
(blimsup (fun i => cthickening (M * r i) (s i)) atTop p : Set α) =ᵐ[μ]
(blimsup (fun i => cthickening (r i) (s i)) atTop p : Set α) := by
have : ∀ (p : ℕ → Prop) {r : ℕ → ℝ} (_ : Tendsto r atTop (𝓝[>] 0)),
(blimsup (fun i => cthickening (M * r i) (s i)) atTop p : Set α) =ᵐ[μ]
(blimsup (fun i => cthickening (r i) (s i)) atTop p : Set α) := by
clear p hr r; intro p r hr
have hr' : Tendsto (fun i => M * r i) atTop (𝓝[>] 0) := by
convert TendstoNhdsWithinIoi.const_mul hM hr <;> simp only [mul_zero]
refine eventuallyLE_antisymm_iff.mpr ⟨?_, ?_⟩
· exact blimsup_cthickening_ae_le_of_eventually_mul_le μ p (inv_pos.mpr hM) hr'
(eventually_of_forall fun i => by rw [inv_mul_cancel_left₀ hM.ne' (r i)])
· exact blimsup_cthickening_ae_le_of_eventually_mul_le μ p hM hr
(eventually_of_forall fun i => le_refl _)
let r' : ℕ → ℝ := fun i => if 0 < r i then r i else 1 / ((i : ℝ) + 1)
have hr' : Tendsto r' atTop (𝓝[>] 0) := by
refine tendsto_nhdsWithin_iff.mpr
⟨Tendsto.if' hr tendsto_one_div_add_atTop_nhds_zero_nat, eventually_of_forall fun i => ?_⟩
by_cases hi : 0 < r i
· simp [r', hi]
· simp only [r', hi, one_div, mem_Ioi, if_false, inv_pos]; positivity
have h₀ : ∀ i, p i ∧ 0 < r i → cthickening (r i) (s i) = cthickening (r' i) (s i) := by
rintro i ⟨-, hi⟩; congr! 1; change r i = ite (0 < r i) (r i) _; simp [hi]
have h₁ : ∀ i, p i ∧ 0 < r i → cthickening (M * r i) (s i) = cthickening (M * r' i) (s i) := by
rintro i ⟨-, hi⟩; simp only [r', hi, mul_ite, if_true]
have h₂ : ∀ i, p i ∧ r i ≤ 0 → cthickening (M * r i) (s i) = cthickening (r i) (s i) := by
rintro i ⟨-, hi⟩
have hi' : M * r i ≤ 0 := mul_nonpos_of_nonneg_of_nonpos hM.le hi
rw [cthickening_of_nonpos hi, cthickening_of_nonpos hi']
have hp : p = fun i => p i ∧ 0 < r i ∨ p i ∧ r i ≤ 0 := by
ext i; simp [← and_or_left, lt_or_le 0 (r i)]
rw [hp, blimsup_or_eq_sup, blimsup_or_eq_sup]
simp only [sup_eq_union]
rw [blimsup_congr (eventually_of_forall h₀), blimsup_congr (eventually_of_forall h₁),
blimsup_congr (eventually_of_forall h₂)]
exact ae_eq_set_union (this (fun i => p i ∧ 0 < r i) hr') (ae_eq_refl _)
#align blimsup_cthickening_mul_ae_eq blimsup_cthickening_mul_ae_eq
theorem blimsup_cthickening_ae_eq_blimsup_thickening {p : ℕ → Prop} {s : ℕ → Set α} {r : ℕ → ℝ}
(hr : Tendsto r atTop (𝓝 0)) (hr' : ∀ᶠ i in atTop, p i → 0 < r i) :
(blimsup (fun i => cthickening (r i) (s i)) atTop p : Set α) =ᵐ[μ]
(blimsup (fun i => thickening (r i) (s i)) atTop p : Set α) := by
refine eventuallyLE_antisymm_iff.mpr ⟨?_, HasSubset.Subset.eventuallyLE (?_ : _ ≤ _)⟩
· rw [eventuallyLE_congr (blimsup_cthickening_mul_ae_eq μ p s (@one_half_pos ℝ _) r hr).symm
EventuallyEq.rfl]
apply HasSubset.Subset.eventuallyLE
change _ ≤ _
refine mono_blimsup' (hr'.mono fun i hi pi => cthickening_subset_thickening' (hi pi) ?_ (s i))
nlinarith [hi pi]
· exact mono_blimsup fun i _ => thickening_subset_cthickening _ _
#align blimsup_cthickening_ae_eq_blimsup_thickening blimsup_cthickening_ae_eq_blimsup_thickening
| Mathlib/MeasureTheory/Covering/LiminfLimsup.lean | 247 | 256 | theorem blimsup_thickening_mul_ae_eq_aux (p : ℕ → Prop) (s : ℕ → Set α) {M : ℝ} (hM : 0 < M)
(r : ℕ → ℝ) (hr : Tendsto r atTop (𝓝 0)) (hr' : ∀ᶠ i in atTop, p i → 0 < r i) :
(blimsup (fun i => thickening (M * r i) (s i)) atTop p : Set α) =ᵐ[μ]
(blimsup (fun i => thickening (r i) (s i)) atTop p : Set α) := by |
have h₁ := blimsup_cthickening_ae_eq_blimsup_thickening (s := s) μ hr hr'
have h₂ := blimsup_cthickening_mul_ae_eq μ p s hM r hr
replace hr : Tendsto (fun i => M * r i) atTop (𝓝 0) := by convert hr.const_mul M; simp
replace hr' : ∀ᶠ i in atTop, p i → 0 < M * r i := hr'.mono fun i hi hip ↦ mul_pos hM (hi hip)
have h₃ := blimsup_cthickening_ae_eq_blimsup_thickening (s := s) μ hr hr'
exact h₃.symm.trans (h₂.trans h₁)
|
import Mathlib.Analysis.NormedSpace.BoundedLinearMaps
import Mathlib.Topology.FiberBundle.Basic
#align_import topology.vector_bundle.basic from "leanprover-community/mathlib"@"e473c3198bb41f68560cab68a0529c854b618833"
noncomputable section
open scoped Classical
open Bundle Set
open scoped Topology
variable (R : Type*) {B : Type*} (F : Type*) (E : B → Type*)
section TopologicalVectorSpace
variable {F E}
variable [Semiring R] [TopologicalSpace F] [TopologicalSpace B]
protected class Pretrivialization.IsLinear [AddCommMonoid F] [Module R F] [∀ x, AddCommMonoid (E x)]
[∀ x, Module R (E x)] (e : Pretrivialization F (π F E)) : Prop where
linear : ∀ b ∈ e.baseSet, IsLinearMap R fun x : E b => (e ⟨b, x⟩).2
#align pretrivialization.is_linear Pretrivialization.IsLinear
namespace Pretrivialization
variable (e : Pretrivialization F (π F E)) {x : TotalSpace F E} {b : B} {y : E b}
theorem linear [AddCommMonoid F] [Module R F] [∀ x, AddCommMonoid (E x)] [∀ x, Module R (E x)]
[e.IsLinear R] {b : B} (hb : b ∈ e.baseSet) :
IsLinearMap R fun x : E b => (e ⟨b, x⟩).2 :=
Pretrivialization.IsLinear.linear b hb
#align pretrivialization.linear Pretrivialization.linear
variable [AddCommMonoid F] [Module R F] [∀ x, AddCommMonoid (E x)] [∀ x, Module R (E x)]
@[simps!]
protected def symmₗ (e : Pretrivialization F (π F E)) [e.IsLinear R] (b : B) : F →ₗ[R] E b := by
refine IsLinearMap.mk' (e.symm b) ?_
by_cases hb : b ∈ e.baseSet
· exact (((e.linear R hb).mk' _).inverse (e.symm b) (e.symm_apply_apply_mk hb) fun v ↦
congr_arg Prod.snd <| e.apply_mk_symm hb v).isLinear
· rw [e.coe_symm_of_not_mem hb]
exact (0 : F →ₗ[R] E b).isLinear
#align pretrivialization.symmₗ Pretrivialization.symmₗ
@[simps (config := .asFn)]
def linearEquivAt (e : Pretrivialization F (π F E)) [e.IsLinear R] (b : B) (hb : b ∈ e.baseSet) :
E b ≃ₗ[R] F where
toFun y := (e ⟨b, y⟩).2
invFun := e.symm b
left_inv := e.symm_apply_apply_mk hb
right_inv v := by simp_rw [e.apply_mk_symm hb v]
map_add' v w := (e.linear R hb).map_add v w
map_smul' c v := (e.linear R hb).map_smul c v
#align pretrivialization.linear_equiv_at Pretrivialization.linearEquivAt
protected def linearMapAt (e : Pretrivialization F (π F E)) [e.IsLinear R] (b : B) : E b →ₗ[R] F :=
if hb : b ∈ e.baseSet then e.linearEquivAt R b hb else 0
#align pretrivialization.linear_map_at Pretrivialization.linearMapAt
variable {R}
theorem coe_linearMapAt (e : Pretrivialization F (π F E)) [e.IsLinear R] (b : B) :
⇑(e.linearMapAt R b) = fun y => if b ∈ e.baseSet then (e ⟨b, y⟩).2 else 0 := by
rw [Pretrivialization.linearMapAt]
split_ifs <;> rfl
#align pretrivialization.coe_linear_map_at Pretrivialization.coe_linearMapAt
theorem coe_linearMapAt_of_mem (e : Pretrivialization F (π F E)) [e.IsLinear R] {b : B}
(hb : b ∈ e.baseSet) : ⇑(e.linearMapAt R b) = fun y => (e ⟨b, y⟩).2 := by
simp_rw [coe_linearMapAt, if_pos hb]
#align pretrivialization.coe_linear_map_at_of_mem Pretrivialization.coe_linearMapAt_of_mem
theorem linearMapAt_apply (e : Pretrivialization F (π F E)) [e.IsLinear R] {b : B} (y : E b) :
e.linearMapAt R b y = if b ∈ e.baseSet then (e ⟨b, y⟩).2 else 0 := by
rw [coe_linearMapAt]
#align pretrivialization.linear_map_at_apply Pretrivialization.linearMapAt_apply
theorem linearMapAt_def_of_mem (e : Pretrivialization F (π F E)) [e.IsLinear R] {b : B}
(hb : b ∈ e.baseSet) : e.linearMapAt R b = e.linearEquivAt R b hb :=
dif_pos hb
#align pretrivialization.linear_map_at_def_of_mem Pretrivialization.linearMapAt_def_of_mem
theorem linearMapAt_def_of_not_mem (e : Pretrivialization F (π F E)) [e.IsLinear R] {b : B}
(hb : b ∉ e.baseSet) : e.linearMapAt R b = 0 :=
dif_neg hb
#align pretrivialization.linear_map_at_def_of_not_mem Pretrivialization.linearMapAt_def_of_not_mem
theorem linearMapAt_eq_zero (e : Pretrivialization F (π F E)) [e.IsLinear R] {b : B}
(hb : b ∉ e.baseSet) : e.linearMapAt R b = 0 :=
dif_neg hb
#align pretrivialization.linear_map_at_eq_zero Pretrivialization.linearMapAt_eq_zero
theorem symmₗ_linearMapAt (e : Pretrivialization F (π F E)) [e.IsLinear R] {b : B}
(hb : b ∈ e.baseSet) (y : E b) : e.symmₗ R b (e.linearMapAt R b y) = y := by
rw [e.linearMapAt_def_of_mem hb]
exact (e.linearEquivAt R b hb).left_inv y
#align pretrivialization.symmₗ_linear_map_at Pretrivialization.symmₗ_linearMapAt
| Mathlib/Topology/VectorBundle/Basic.lean | 157 | 160 | theorem linearMapAt_symmₗ (e : Pretrivialization F (π F E)) [e.IsLinear R] {b : B}
(hb : b ∈ e.baseSet) (y : F) : e.linearMapAt R b (e.symmₗ R b y) = y := by |
rw [e.linearMapAt_def_of_mem hb]
exact (e.linearEquivAt R b hb).right_inv y
|
import Mathlib.Geometry.Euclidean.Angle.Oriented.Affine
import Mathlib.Geometry.Euclidean.Angle.Unoriented.RightAngle
#align_import geometry.euclidean.angle.oriented.right_angle from "leanprover-community/mathlib"@"46b633fd842bef9469441c0209906f6dddd2b4f5"
noncomputable section
open scoped EuclideanGeometry
open scoped Real
open scoped RealInnerProductSpace
namespace Orientation
open FiniteDimensional
variable {V : Type*} [NormedAddCommGroup V] [InnerProductSpace ℝ V]
variable [hd2 : Fact (finrank ℝ V = 2)] (o : Orientation ℝ V (Fin 2))
theorem oangle_add_right_eq_arccos_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
o.oangle x (x + y) = Real.arccos (‖x‖ / ‖x + y‖) := by
have hs : (o.oangle x (x + y)).sign = 1 := by
rw [oangle_sign_add_right, h, Real.Angle.sign_coe_pi_div_two]
rw [o.oangle_eq_angle_of_sign_eq_one hs,
InnerProductGeometry.angle_add_eq_arccos_of_inner_eq_zero
(o.inner_eq_zero_of_oangle_eq_pi_div_two h)]
#align orientation.oangle_add_right_eq_arccos_of_oangle_eq_pi_div_two Orientation.oangle_add_right_eq_arccos_of_oangle_eq_pi_div_two
theorem oangle_add_left_eq_arccos_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
o.oangle (x + y) y = Real.arccos (‖y‖ / ‖x + y‖) := by
rw [← neg_inj, oangle_rev, ← oangle_neg_orientation_eq_neg, neg_inj] at h ⊢
rw [add_comm]
exact (-o).oangle_add_right_eq_arccos_of_oangle_eq_pi_div_two h
#align orientation.oangle_add_left_eq_arccos_of_oangle_eq_pi_div_two Orientation.oangle_add_left_eq_arccos_of_oangle_eq_pi_div_two
theorem oangle_add_right_eq_arcsin_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
o.oangle x (x + y) = Real.arcsin (‖y‖ / ‖x + y‖) := by
have hs : (o.oangle x (x + y)).sign = 1 := by
rw [oangle_sign_add_right, h, Real.Angle.sign_coe_pi_div_two]
rw [o.oangle_eq_angle_of_sign_eq_one hs,
InnerProductGeometry.angle_add_eq_arcsin_of_inner_eq_zero
(o.inner_eq_zero_of_oangle_eq_pi_div_two h)
(Or.inl (o.left_ne_zero_of_oangle_eq_pi_div_two h))]
#align orientation.oangle_add_right_eq_arcsin_of_oangle_eq_pi_div_two Orientation.oangle_add_right_eq_arcsin_of_oangle_eq_pi_div_two
theorem oangle_add_left_eq_arcsin_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
o.oangle (x + y) y = Real.arcsin (‖x‖ / ‖x + y‖) := by
rw [← neg_inj, oangle_rev, ← oangle_neg_orientation_eq_neg, neg_inj] at h ⊢
rw [add_comm]
exact (-o).oangle_add_right_eq_arcsin_of_oangle_eq_pi_div_two h
#align orientation.oangle_add_left_eq_arcsin_of_oangle_eq_pi_div_two Orientation.oangle_add_left_eq_arcsin_of_oangle_eq_pi_div_two
theorem oangle_add_right_eq_arctan_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
o.oangle x (x + y) = Real.arctan (‖y‖ / ‖x‖) := by
have hs : (o.oangle x (x + y)).sign = 1 := by
rw [oangle_sign_add_right, h, Real.Angle.sign_coe_pi_div_two]
rw [o.oangle_eq_angle_of_sign_eq_one hs,
InnerProductGeometry.angle_add_eq_arctan_of_inner_eq_zero
(o.inner_eq_zero_of_oangle_eq_pi_div_two h) (o.left_ne_zero_of_oangle_eq_pi_div_two h)]
#align orientation.oangle_add_right_eq_arctan_of_oangle_eq_pi_div_two Orientation.oangle_add_right_eq_arctan_of_oangle_eq_pi_div_two
theorem oangle_add_left_eq_arctan_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
o.oangle (x + y) y = Real.arctan (‖x‖ / ‖y‖) := by
rw [← neg_inj, oangle_rev, ← oangle_neg_orientation_eq_neg, neg_inj] at h ⊢
rw [add_comm]
exact (-o).oangle_add_right_eq_arctan_of_oangle_eq_pi_div_two h
#align orientation.oangle_add_left_eq_arctan_of_oangle_eq_pi_div_two Orientation.oangle_add_left_eq_arctan_of_oangle_eq_pi_div_two
theorem cos_oangle_add_right_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
Real.Angle.cos (o.oangle x (x + y)) = ‖x‖ / ‖x + y‖ := by
have hs : (o.oangle x (x + y)).sign = 1 := by
rw [oangle_sign_add_right, h, Real.Angle.sign_coe_pi_div_two]
rw [o.oangle_eq_angle_of_sign_eq_one hs, Real.Angle.cos_coe,
InnerProductGeometry.cos_angle_add_of_inner_eq_zero (o.inner_eq_zero_of_oangle_eq_pi_div_two h)]
#align orientation.cos_oangle_add_right_of_oangle_eq_pi_div_two Orientation.cos_oangle_add_right_of_oangle_eq_pi_div_two
theorem cos_oangle_add_left_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
Real.Angle.cos (o.oangle (x + y) y) = ‖y‖ / ‖x + y‖ := by
rw [← neg_inj, oangle_rev, ← oangle_neg_orientation_eq_neg, neg_inj] at h ⊢
rw [add_comm]
exact (-o).cos_oangle_add_right_of_oangle_eq_pi_div_two h
#align orientation.cos_oangle_add_left_of_oangle_eq_pi_div_two Orientation.cos_oangle_add_left_of_oangle_eq_pi_div_two
theorem sin_oangle_add_right_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
Real.Angle.sin (o.oangle x (x + y)) = ‖y‖ / ‖x + y‖ := by
have hs : (o.oangle x (x + y)).sign = 1 := by
rw [oangle_sign_add_right, h, Real.Angle.sign_coe_pi_div_two]
rw [o.oangle_eq_angle_of_sign_eq_one hs, Real.Angle.sin_coe,
InnerProductGeometry.sin_angle_add_of_inner_eq_zero (o.inner_eq_zero_of_oangle_eq_pi_div_two h)
(Or.inl (o.left_ne_zero_of_oangle_eq_pi_div_two h))]
#align orientation.sin_oangle_add_right_of_oangle_eq_pi_div_two Orientation.sin_oangle_add_right_of_oangle_eq_pi_div_two
theorem sin_oangle_add_left_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
Real.Angle.sin (o.oangle (x + y) y) = ‖x‖ / ‖x + y‖ := by
rw [← neg_inj, oangle_rev, ← oangle_neg_orientation_eq_neg, neg_inj] at h ⊢
rw [add_comm]
exact (-o).sin_oangle_add_right_of_oangle_eq_pi_div_two h
#align orientation.sin_oangle_add_left_of_oangle_eq_pi_div_two Orientation.sin_oangle_add_left_of_oangle_eq_pi_div_two
theorem tan_oangle_add_right_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
Real.Angle.tan (o.oangle x (x + y)) = ‖y‖ / ‖x‖ := by
have hs : (o.oangle x (x + y)).sign = 1 := by
rw [oangle_sign_add_right, h, Real.Angle.sign_coe_pi_div_two]
rw [o.oangle_eq_angle_of_sign_eq_one hs, Real.Angle.tan_coe,
InnerProductGeometry.tan_angle_add_of_inner_eq_zero (o.inner_eq_zero_of_oangle_eq_pi_div_two h)]
#align orientation.tan_oangle_add_right_of_oangle_eq_pi_div_two Orientation.tan_oangle_add_right_of_oangle_eq_pi_div_two
theorem tan_oangle_add_left_of_oangle_eq_pi_div_two {x y : V} (h : o.oangle x y = ↑(π / 2)) :
Real.Angle.tan (o.oangle (x + y) y) = ‖x‖ / ‖y‖ := by
rw [← neg_inj, oangle_rev, ← oangle_neg_orientation_eq_neg, neg_inj] at h ⊢
rw [add_comm]
exact (-o).tan_oangle_add_right_of_oangle_eq_pi_div_two h
#align orientation.tan_oangle_add_left_of_oangle_eq_pi_div_two Orientation.tan_oangle_add_left_of_oangle_eq_pi_div_two
theorem cos_oangle_add_right_mul_norm_of_oangle_eq_pi_div_two {x y : V}
(h : o.oangle x y = ↑(π / 2)) : Real.Angle.cos (o.oangle x (x + y)) * ‖x + y‖ = ‖x‖ := by
have hs : (o.oangle x (x + y)).sign = 1 := by
rw [oangle_sign_add_right, h, Real.Angle.sign_coe_pi_div_two]
rw [o.oangle_eq_angle_of_sign_eq_one hs, Real.Angle.cos_coe,
InnerProductGeometry.cos_angle_add_mul_norm_of_inner_eq_zero
(o.inner_eq_zero_of_oangle_eq_pi_div_two h)]
#align orientation.cos_oangle_add_right_mul_norm_of_oangle_eq_pi_div_two Orientation.cos_oangle_add_right_mul_norm_of_oangle_eq_pi_div_two
theorem cos_oangle_add_left_mul_norm_of_oangle_eq_pi_div_two {x y : V}
(h : o.oangle x y = ↑(π / 2)) : Real.Angle.cos (o.oangle (x + y) y) * ‖x + y‖ = ‖y‖ := by
rw [← neg_inj, oangle_rev, ← oangle_neg_orientation_eq_neg, neg_inj] at h ⊢
rw [add_comm]
exact (-o).cos_oangle_add_right_mul_norm_of_oangle_eq_pi_div_two h
#align orientation.cos_oangle_add_left_mul_norm_of_oangle_eq_pi_div_two Orientation.cos_oangle_add_left_mul_norm_of_oangle_eq_pi_div_two
theorem sin_oangle_add_right_mul_norm_of_oangle_eq_pi_div_two {x y : V}
(h : o.oangle x y = ↑(π / 2)) : Real.Angle.sin (o.oangle x (x + y)) * ‖x + y‖ = ‖y‖ := by
have hs : (o.oangle x (x + y)).sign = 1 := by
rw [oangle_sign_add_right, h, Real.Angle.sign_coe_pi_div_two]
rw [o.oangle_eq_angle_of_sign_eq_one hs, Real.Angle.sin_coe,
InnerProductGeometry.sin_angle_add_mul_norm_of_inner_eq_zero
(o.inner_eq_zero_of_oangle_eq_pi_div_two h)]
#align orientation.sin_oangle_add_right_mul_norm_of_oangle_eq_pi_div_two Orientation.sin_oangle_add_right_mul_norm_of_oangle_eq_pi_div_two
theorem sin_oangle_add_left_mul_norm_of_oangle_eq_pi_div_two {x y : V}
(h : o.oangle x y = ↑(π / 2)) : Real.Angle.sin (o.oangle (x + y) y) * ‖x + y‖ = ‖x‖ := by
rw [← neg_inj, oangle_rev, ← oangle_neg_orientation_eq_neg, neg_inj] at h ⊢
rw [add_comm]
exact (-o).sin_oangle_add_right_mul_norm_of_oangle_eq_pi_div_two h
#align orientation.sin_oangle_add_left_mul_norm_of_oangle_eq_pi_div_two Orientation.sin_oangle_add_left_mul_norm_of_oangle_eq_pi_div_two
| Mathlib/Geometry/Euclidean/Angle/Oriented/RightAngle.lean | 184 | 191 | theorem tan_oangle_add_right_mul_norm_of_oangle_eq_pi_div_two {x y : V}
(h : o.oangle x y = ↑(π / 2)) : Real.Angle.tan (o.oangle x (x + y)) * ‖x‖ = ‖y‖ := by |
have hs : (o.oangle x (x + y)).sign = 1 := by
rw [oangle_sign_add_right, h, Real.Angle.sign_coe_pi_div_two]
rw [o.oangle_eq_angle_of_sign_eq_one hs, Real.Angle.tan_coe,
InnerProductGeometry.tan_angle_add_mul_norm_of_inner_eq_zero
(o.inner_eq_zero_of_oangle_eq_pi_div_two h)
(Or.inl (o.left_ne_zero_of_oangle_eq_pi_div_two h))]
|
import Mathlib.Algebra.ModEq
import Mathlib.Algebra.Module.Defs
import Mathlib.Algebra.Order.Archimedean
import Mathlib.Algebra.Periodic
import Mathlib.Data.Int.SuccPred
import Mathlib.GroupTheory.QuotientGroup
import Mathlib.Order.Circular
import Mathlib.Data.List.TFAE
import Mathlib.Data.Set.Lattice
#align_import algebra.order.to_interval_mod from "leanprover-community/mathlib"@"213b0cff7bc5ab6696ee07cceec80829ce42efec"
noncomputable section
section LinearOrderedAddCommGroup
variable {α : Type*} [LinearOrderedAddCommGroup α] [hα : Archimedean α] {p : α} (hp : 0 < p)
{a b c : α} {n : ℤ}
def toIcoDiv (a b : α) : ℤ :=
(existsUnique_sub_zsmul_mem_Ico hp b a).choose
#align to_Ico_div toIcoDiv
theorem sub_toIcoDiv_zsmul_mem_Ico (a b : α) : b - toIcoDiv hp a b • p ∈ Set.Ico a (a + p) :=
(existsUnique_sub_zsmul_mem_Ico hp b a).choose_spec.1
#align sub_to_Ico_div_zsmul_mem_Ico sub_toIcoDiv_zsmul_mem_Ico
theorem toIcoDiv_eq_of_sub_zsmul_mem_Ico (h : b - n • p ∈ Set.Ico a (a + p)) :
toIcoDiv hp a b = n :=
((existsUnique_sub_zsmul_mem_Ico hp b a).choose_spec.2 _ h).symm
#align to_Ico_div_eq_of_sub_zsmul_mem_Ico toIcoDiv_eq_of_sub_zsmul_mem_Ico
def toIocDiv (a b : α) : ℤ :=
(existsUnique_sub_zsmul_mem_Ioc hp b a).choose
#align to_Ioc_div toIocDiv
theorem sub_toIocDiv_zsmul_mem_Ioc (a b : α) : b - toIocDiv hp a b • p ∈ Set.Ioc a (a + p) :=
(existsUnique_sub_zsmul_mem_Ioc hp b a).choose_spec.1
#align sub_to_Ioc_div_zsmul_mem_Ioc sub_toIocDiv_zsmul_mem_Ioc
theorem toIocDiv_eq_of_sub_zsmul_mem_Ioc (h : b - n • p ∈ Set.Ioc a (a + p)) :
toIocDiv hp a b = n :=
((existsUnique_sub_zsmul_mem_Ioc hp b a).choose_spec.2 _ h).symm
#align to_Ioc_div_eq_of_sub_zsmul_mem_Ioc toIocDiv_eq_of_sub_zsmul_mem_Ioc
def toIcoMod (a b : α) : α :=
b - toIcoDiv hp a b • p
#align to_Ico_mod toIcoMod
def toIocMod (a b : α) : α :=
b - toIocDiv hp a b • p
#align to_Ioc_mod toIocMod
theorem toIcoMod_mem_Ico (a b : α) : toIcoMod hp a b ∈ Set.Ico a (a + p) :=
sub_toIcoDiv_zsmul_mem_Ico hp a b
#align to_Ico_mod_mem_Ico toIcoMod_mem_Ico
theorem toIcoMod_mem_Ico' (b : α) : toIcoMod hp 0 b ∈ Set.Ico 0 p := by
convert toIcoMod_mem_Ico hp 0 b
exact (zero_add p).symm
#align to_Ico_mod_mem_Ico' toIcoMod_mem_Ico'
theorem toIocMod_mem_Ioc (a b : α) : toIocMod hp a b ∈ Set.Ioc a (a + p) :=
sub_toIocDiv_zsmul_mem_Ioc hp a b
#align to_Ioc_mod_mem_Ioc toIocMod_mem_Ioc
theorem left_le_toIcoMod (a b : α) : a ≤ toIcoMod hp a b :=
(Set.mem_Ico.1 (toIcoMod_mem_Ico hp a b)).1
#align left_le_to_Ico_mod left_le_toIcoMod
theorem left_lt_toIocMod (a b : α) : a < toIocMod hp a b :=
(Set.mem_Ioc.1 (toIocMod_mem_Ioc hp a b)).1
#align left_lt_to_Ioc_mod left_lt_toIocMod
theorem toIcoMod_lt_right (a b : α) : toIcoMod hp a b < a + p :=
(Set.mem_Ico.1 (toIcoMod_mem_Ico hp a b)).2
#align to_Ico_mod_lt_right toIcoMod_lt_right
theorem toIocMod_le_right (a b : α) : toIocMod hp a b ≤ a + p :=
(Set.mem_Ioc.1 (toIocMod_mem_Ioc hp a b)).2
#align to_Ioc_mod_le_right toIocMod_le_right
@[simp]
theorem self_sub_toIcoDiv_zsmul (a b : α) : b - toIcoDiv hp a b • p = toIcoMod hp a b :=
rfl
#align self_sub_to_Ico_div_zsmul self_sub_toIcoDiv_zsmul
@[simp]
theorem self_sub_toIocDiv_zsmul (a b : α) : b - toIocDiv hp a b • p = toIocMod hp a b :=
rfl
#align self_sub_to_Ioc_div_zsmul self_sub_toIocDiv_zsmul
@[simp]
theorem toIcoDiv_zsmul_sub_self (a b : α) : toIcoDiv hp a b • p - b = -toIcoMod hp a b := by
rw [toIcoMod, neg_sub]
#align to_Ico_div_zsmul_sub_self toIcoDiv_zsmul_sub_self
@[simp]
theorem toIocDiv_zsmul_sub_self (a b : α) : toIocDiv hp a b • p - b = -toIocMod hp a b := by
rw [toIocMod, neg_sub]
#align to_Ioc_div_zsmul_sub_self toIocDiv_zsmul_sub_self
@[simp]
theorem toIcoMod_sub_self (a b : α) : toIcoMod hp a b - b = -toIcoDiv hp a b • p := by
rw [toIcoMod, sub_sub_cancel_left, neg_smul]
#align to_Ico_mod_sub_self toIcoMod_sub_self
@[simp]
theorem toIocMod_sub_self (a b : α) : toIocMod hp a b - b = -toIocDiv hp a b • p := by
rw [toIocMod, sub_sub_cancel_left, neg_smul]
#align to_Ioc_mod_sub_self toIocMod_sub_self
@[simp]
theorem self_sub_toIcoMod (a b : α) : b - toIcoMod hp a b = toIcoDiv hp a b • p := by
rw [toIcoMod, sub_sub_cancel]
#align self_sub_to_Ico_mod self_sub_toIcoMod
@[simp]
theorem self_sub_toIocMod (a b : α) : b - toIocMod hp a b = toIocDiv hp a b • p := by
rw [toIocMod, sub_sub_cancel]
#align self_sub_to_Ioc_mod self_sub_toIocMod
@[simp]
theorem toIcoMod_add_toIcoDiv_zsmul (a b : α) : toIcoMod hp a b + toIcoDiv hp a b • p = b := by
rw [toIcoMod, sub_add_cancel]
#align to_Ico_mod_add_to_Ico_div_zsmul toIcoMod_add_toIcoDiv_zsmul
@[simp]
theorem toIocMod_add_toIocDiv_zsmul (a b : α) : toIocMod hp a b + toIocDiv hp a b • p = b := by
rw [toIocMod, sub_add_cancel]
#align to_Ioc_mod_add_to_Ioc_div_zsmul toIocMod_add_toIocDiv_zsmul
@[simp]
theorem toIcoDiv_zsmul_sub_toIcoMod (a b : α) : toIcoDiv hp a b • p + toIcoMod hp a b = b := by
rw [add_comm, toIcoMod_add_toIcoDiv_zsmul]
#align to_Ico_div_zsmul_sub_to_Ico_mod toIcoDiv_zsmul_sub_toIcoMod
@[simp]
theorem toIocDiv_zsmul_sub_toIocMod (a b : α) : toIocDiv hp a b • p + toIocMod hp a b = b := by
rw [add_comm, toIocMod_add_toIocDiv_zsmul]
#align to_Ioc_div_zsmul_sub_to_Ioc_mod toIocDiv_zsmul_sub_toIocMod
theorem toIcoMod_eq_iff : toIcoMod hp a b = c ↔ c ∈ Set.Ico a (a + p) ∧ ∃ z : ℤ, b = c + z • p := by
refine
⟨fun h =>
⟨h ▸ toIcoMod_mem_Ico hp a b, toIcoDiv hp a b, h ▸ (toIcoMod_add_toIcoDiv_zsmul _ _ _).symm⟩,
?_⟩
simp_rw [← @sub_eq_iff_eq_add]
rintro ⟨hc, n, rfl⟩
rw [← toIcoDiv_eq_of_sub_zsmul_mem_Ico hp hc, toIcoMod]
#align to_Ico_mod_eq_iff toIcoMod_eq_iff
theorem toIocMod_eq_iff : toIocMod hp a b = c ↔ c ∈ Set.Ioc a (a + p) ∧ ∃ z : ℤ, b = c + z • p := by
refine
⟨fun h =>
⟨h ▸ toIocMod_mem_Ioc hp a b, toIocDiv hp a b, h ▸ (toIocMod_add_toIocDiv_zsmul hp _ _).symm⟩,
?_⟩
simp_rw [← @sub_eq_iff_eq_add]
rintro ⟨hc, n, rfl⟩
rw [← toIocDiv_eq_of_sub_zsmul_mem_Ioc hp hc, toIocMod]
#align to_Ioc_mod_eq_iff toIocMod_eq_iff
@[simp]
theorem toIcoDiv_apply_left (a : α) : toIcoDiv hp a a = 0 :=
toIcoDiv_eq_of_sub_zsmul_mem_Ico hp <| by simp [hp]
#align to_Ico_div_apply_left toIcoDiv_apply_left
@[simp]
theorem toIocDiv_apply_left (a : α) : toIocDiv hp a a = -1 :=
toIocDiv_eq_of_sub_zsmul_mem_Ioc hp <| by simp [hp]
#align to_Ioc_div_apply_left toIocDiv_apply_left
@[simp]
theorem toIcoMod_apply_left (a : α) : toIcoMod hp a a = a := by
rw [toIcoMod_eq_iff hp, Set.left_mem_Ico]
exact ⟨lt_add_of_pos_right _ hp, 0, by simp⟩
#align to_Ico_mod_apply_left toIcoMod_apply_left
@[simp]
theorem toIocMod_apply_left (a : α) : toIocMod hp a a = a + p := by
rw [toIocMod_eq_iff hp, Set.right_mem_Ioc]
exact ⟨lt_add_of_pos_right _ hp, -1, by simp⟩
#align to_Ioc_mod_apply_left toIocMod_apply_left
theorem toIcoDiv_apply_right (a : α) : toIcoDiv hp a (a + p) = 1 :=
toIcoDiv_eq_of_sub_zsmul_mem_Ico hp <| by simp [hp]
#align to_Ico_div_apply_right toIcoDiv_apply_right
theorem toIocDiv_apply_right (a : α) : toIocDiv hp a (a + p) = 0 :=
toIocDiv_eq_of_sub_zsmul_mem_Ioc hp <| by simp [hp]
#align to_Ioc_div_apply_right toIocDiv_apply_right
theorem toIcoMod_apply_right (a : α) : toIcoMod hp a (a + p) = a := by
rw [toIcoMod_eq_iff hp, Set.left_mem_Ico]
exact ⟨lt_add_of_pos_right _ hp, 1, by simp⟩
#align to_Ico_mod_apply_right toIcoMod_apply_right
theorem toIocMod_apply_right (a : α) : toIocMod hp a (a + p) = a + p := by
rw [toIocMod_eq_iff hp, Set.right_mem_Ioc]
exact ⟨lt_add_of_pos_right _ hp, 0, by simp⟩
#align to_Ioc_mod_apply_right toIocMod_apply_right
@[simp]
theorem toIcoDiv_add_zsmul (a b : α) (m : ℤ) : toIcoDiv hp a (b + m • p) = toIcoDiv hp a b + m :=
toIcoDiv_eq_of_sub_zsmul_mem_Ico hp <| by
simpa only [add_smul, add_sub_add_right_eq_sub] using sub_toIcoDiv_zsmul_mem_Ico hp a b
#align to_Ico_div_add_zsmul toIcoDiv_add_zsmul
@[simp]
theorem toIcoDiv_add_zsmul' (a b : α) (m : ℤ) :
toIcoDiv hp (a + m • p) b = toIcoDiv hp a b - m := by
refine toIcoDiv_eq_of_sub_zsmul_mem_Ico _ ?_
rw [sub_smul, ← sub_add, add_right_comm]
simpa using sub_toIcoDiv_zsmul_mem_Ico hp a b
#align to_Ico_div_add_zsmul' toIcoDiv_add_zsmul'
@[simp]
theorem toIocDiv_add_zsmul (a b : α) (m : ℤ) : toIocDiv hp a (b + m • p) = toIocDiv hp a b + m :=
toIocDiv_eq_of_sub_zsmul_mem_Ioc hp <| by
simpa only [add_smul, add_sub_add_right_eq_sub] using sub_toIocDiv_zsmul_mem_Ioc hp a b
#align to_Ioc_div_add_zsmul toIocDiv_add_zsmul
@[simp]
theorem toIocDiv_add_zsmul' (a b : α) (m : ℤ) :
toIocDiv hp (a + m • p) b = toIocDiv hp a b - m := by
refine toIocDiv_eq_of_sub_zsmul_mem_Ioc _ ?_
rw [sub_smul, ← sub_add, add_right_comm]
simpa using sub_toIocDiv_zsmul_mem_Ioc hp a b
#align to_Ioc_div_add_zsmul' toIocDiv_add_zsmul'
@[simp]
theorem toIcoDiv_zsmul_add (a b : α) (m : ℤ) : toIcoDiv hp a (m • p + b) = m + toIcoDiv hp a b := by
rw [add_comm, toIcoDiv_add_zsmul, add_comm]
#align to_Ico_div_zsmul_add toIcoDiv_zsmul_add
@[simp]
theorem toIocDiv_zsmul_add (a b : α) (m : ℤ) : toIocDiv hp a (m • p + b) = m + toIocDiv hp a b := by
rw [add_comm, toIocDiv_add_zsmul, add_comm]
#align to_Ioc_div_zsmul_add toIocDiv_zsmul_add
@[simp]
theorem toIcoDiv_sub_zsmul (a b : α) (m : ℤ) : toIcoDiv hp a (b - m • p) = toIcoDiv hp a b - m := by
rw [sub_eq_add_neg, ← neg_smul, toIcoDiv_add_zsmul, sub_eq_add_neg]
#align to_Ico_div_sub_zsmul toIcoDiv_sub_zsmul
@[simp]
theorem toIcoDiv_sub_zsmul' (a b : α) (m : ℤ) :
toIcoDiv hp (a - m • p) b = toIcoDiv hp a b + m := by
rw [sub_eq_add_neg, ← neg_smul, toIcoDiv_add_zsmul', sub_neg_eq_add]
#align to_Ico_div_sub_zsmul' toIcoDiv_sub_zsmul'
@[simp]
theorem toIocDiv_sub_zsmul (a b : α) (m : ℤ) : toIocDiv hp a (b - m • p) = toIocDiv hp a b - m := by
rw [sub_eq_add_neg, ← neg_smul, toIocDiv_add_zsmul, sub_eq_add_neg]
#align to_Ioc_div_sub_zsmul toIocDiv_sub_zsmul
@[simp]
theorem toIocDiv_sub_zsmul' (a b : α) (m : ℤ) :
toIocDiv hp (a - m • p) b = toIocDiv hp a b + m := by
rw [sub_eq_add_neg, ← neg_smul, toIocDiv_add_zsmul', sub_neg_eq_add]
#align to_Ioc_div_sub_zsmul' toIocDiv_sub_zsmul'
@[simp]
theorem toIcoDiv_add_right (a b : α) : toIcoDiv hp a (b + p) = toIcoDiv hp a b + 1 := by
simpa only [one_zsmul] using toIcoDiv_add_zsmul hp a b 1
#align to_Ico_div_add_right toIcoDiv_add_right
@[simp]
theorem toIcoDiv_add_right' (a b : α) : toIcoDiv hp (a + p) b = toIcoDiv hp a b - 1 := by
simpa only [one_zsmul] using toIcoDiv_add_zsmul' hp a b 1
#align to_Ico_div_add_right' toIcoDiv_add_right'
@[simp]
theorem toIocDiv_add_right (a b : α) : toIocDiv hp a (b + p) = toIocDiv hp a b + 1 := by
simpa only [one_zsmul] using toIocDiv_add_zsmul hp a b 1
#align to_Ioc_div_add_right toIocDiv_add_right
@[simp]
theorem toIocDiv_add_right' (a b : α) : toIocDiv hp (a + p) b = toIocDiv hp a b - 1 := by
simpa only [one_zsmul] using toIocDiv_add_zsmul' hp a b 1
#align to_Ioc_div_add_right' toIocDiv_add_right'
@[simp]
theorem toIcoDiv_add_left (a b : α) : toIcoDiv hp a (p + b) = toIcoDiv hp a b + 1 := by
rw [add_comm, toIcoDiv_add_right]
#align to_Ico_div_add_left toIcoDiv_add_left
@[simp]
theorem toIcoDiv_add_left' (a b : α) : toIcoDiv hp (p + a) b = toIcoDiv hp a b - 1 := by
rw [add_comm, toIcoDiv_add_right']
#align to_Ico_div_add_left' toIcoDiv_add_left'
@[simp]
theorem toIocDiv_add_left (a b : α) : toIocDiv hp a (p + b) = toIocDiv hp a b + 1 := by
rw [add_comm, toIocDiv_add_right]
#align to_Ioc_div_add_left toIocDiv_add_left
@[simp]
theorem toIocDiv_add_left' (a b : α) : toIocDiv hp (p + a) b = toIocDiv hp a b - 1 := by
rw [add_comm, toIocDiv_add_right']
#align to_Ioc_div_add_left' toIocDiv_add_left'
@[simp]
theorem toIcoDiv_sub (a b : α) : toIcoDiv hp a (b - p) = toIcoDiv hp a b - 1 := by
simpa only [one_zsmul] using toIcoDiv_sub_zsmul hp a b 1
#align to_Ico_div_sub toIcoDiv_sub
@[simp]
theorem toIcoDiv_sub' (a b : α) : toIcoDiv hp (a - p) b = toIcoDiv hp a b + 1 := by
simpa only [one_zsmul] using toIcoDiv_sub_zsmul' hp a b 1
#align to_Ico_div_sub' toIcoDiv_sub'
@[simp]
theorem toIocDiv_sub (a b : α) : toIocDiv hp a (b - p) = toIocDiv hp a b - 1 := by
simpa only [one_zsmul] using toIocDiv_sub_zsmul hp a b 1
#align to_Ioc_div_sub toIocDiv_sub
@[simp]
theorem toIocDiv_sub' (a b : α) : toIocDiv hp (a - p) b = toIocDiv hp a b + 1 := by
simpa only [one_zsmul] using toIocDiv_sub_zsmul' hp a b 1
#align to_Ioc_div_sub' toIocDiv_sub'
theorem toIcoDiv_sub_eq_toIcoDiv_add (a b c : α) :
toIcoDiv hp a (b - c) = toIcoDiv hp (a + c) b := by
apply toIcoDiv_eq_of_sub_zsmul_mem_Ico
rw [← sub_right_comm, Set.sub_mem_Ico_iff_left, add_right_comm]
exact sub_toIcoDiv_zsmul_mem_Ico hp (a + c) b
#align to_Ico_div_sub_eq_to_Ico_div_add toIcoDiv_sub_eq_toIcoDiv_add
theorem toIocDiv_sub_eq_toIocDiv_add (a b c : α) :
toIocDiv hp a (b - c) = toIocDiv hp (a + c) b := by
apply toIocDiv_eq_of_sub_zsmul_mem_Ioc
rw [← sub_right_comm, Set.sub_mem_Ioc_iff_left, add_right_comm]
exact sub_toIocDiv_zsmul_mem_Ioc hp (a + c) b
#align to_Ioc_div_sub_eq_to_Ioc_div_add toIocDiv_sub_eq_toIocDiv_add
theorem toIcoDiv_sub_eq_toIcoDiv_add' (a b c : α) :
toIcoDiv hp (a - c) b = toIcoDiv hp a (b + c) := by
rw [← sub_neg_eq_add, toIcoDiv_sub_eq_toIcoDiv_add, sub_eq_add_neg]
#align to_Ico_div_sub_eq_to_Ico_div_add' toIcoDiv_sub_eq_toIcoDiv_add'
theorem toIocDiv_sub_eq_toIocDiv_add' (a b c : α) :
toIocDiv hp (a - c) b = toIocDiv hp a (b + c) := by
rw [← sub_neg_eq_add, toIocDiv_sub_eq_toIocDiv_add, sub_eq_add_neg]
#align to_Ioc_div_sub_eq_to_Ioc_div_add' toIocDiv_sub_eq_toIocDiv_add'
theorem toIcoDiv_neg (a b : α) : toIcoDiv hp a (-b) = -(toIocDiv hp (-a) b + 1) := by
suffices toIcoDiv hp a (-b) = -toIocDiv hp (-(a + p)) b by
rwa [neg_add, ← sub_eq_add_neg, toIocDiv_sub_eq_toIocDiv_add', toIocDiv_add_right] at this
rw [← neg_eq_iff_eq_neg, eq_comm]
apply toIocDiv_eq_of_sub_zsmul_mem_Ioc
obtain ⟨hc, ho⟩ := sub_toIcoDiv_zsmul_mem_Ico hp a (-b)
rw [← neg_lt_neg_iff, neg_sub' (-b), neg_neg, ← neg_smul] at ho
rw [← neg_le_neg_iff, neg_sub' (-b), neg_neg, ← neg_smul] at hc
refine ⟨ho, hc.trans_eq ?_⟩
rw [neg_add, neg_add_cancel_right]
#align to_Ico_div_neg toIcoDiv_neg
theorem toIcoDiv_neg' (a b : α) : toIcoDiv hp (-a) b = -(toIocDiv hp a (-b) + 1) := by
simpa only [neg_neg] using toIcoDiv_neg hp (-a) (-b)
#align to_Ico_div_neg' toIcoDiv_neg'
theorem toIocDiv_neg (a b : α) : toIocDiv hp a (-b) = -(toIcoDiv hp (-a) b + 1) := by
rw [← neg_neg b, toIcoDiv_neg, neg_neg, neg_neg, neg_add', neg_neg, add_sub_cancel_right]
#align to_Ioc_div_neg toIocDiv_neg
| Mathlib/Algebra/Order/ToIntervalMod.lean | 402 | 403 | theorem toIocDiv_neg' (a b : α) : toIocDiv hp (-a) b = -(toIcoDiv hp a (-b) + 1) := by |
simpa only [neg_neg] using toIocDiv_neg hp (-a) (-b)
|
import Mathlib.Algebra.CharP.Two
import Mathlib.Algebra.CharP.Reduced
import Mathlib.Algebra.NeZero
import Mathlib.Algebra.Polynomial.RingDivision
import Mathlib.GroupTheory.SpecificGroups.Cyclic
import Mathlib.NumberTheory.Divisors
import Mathlib.RingTheory.IntegralDomain
import Mathlib.Tactic.Zify
#align_import ring_theory.roots_of_unity.basic from "leanprover-community/mathlib"@"7fdeecc0d03cd40f7a165e6cf00a4d2286db599f"
open scoped Classical Polynomial
noncomputable section
open Polynomial
open Finset
variable {M N G R S F : Type*}
variable [CommMonoid M] [CommMonoid N] [DivisionCommMonoid G]
section rootsOfUnity
variable {k l : ℕ+}
def rootsOfUnity (k : ℕ+) (M : Type*) [CommMonoid M] : Subgroup Mˣ where
carrier := {ζ | ζ ^ (k : ℕ) = 1}
one_mem' := one_pow _
mul_mem' _ _ := by simp_all only [Set.mem_setOf_eq, mul_pow, one_mul]
inv_mem' _ := by simp_all only [Set.mem_setOf_eq, inv_pow, inv_one]
#align roots_of_unity rootsOfUnity
@[simp]
theorem mem_rootsOfUnity (k : ℕ+) (ζ : Mˣ) : ζ ∈ rootsOfUnity k M ↔ ζ ^ (k : ℕ) = 1 :=
Iff.rfl
#align mem_roots_of_unity mem_rootsOfUnity
theorem mem_rootsOfUnity' (k : ℕ+) (ζ : Mˣ) : ζ ∈ rootsOfUnity k M ↔ (ζ : M) ^ (k : ℕ) = 1 := by
rw [mem_rootsOfUnity]; norm_cast
#align mem_roots_of_unity' mem_rootsOfUnity'
@[simp]
theorem rootsOfUnity_one (M : Type*) [CommMonoid M] : rootsOfUnity 1 M = ⊥ := by ext; simp
theorem rootsOfUnity.coe_injective {n : ℕ+} :
Function.Injective (fun x : rootsOfUnity n M ↦ x.val.val) :=
Units.ext.comp fun _ _ => Subtype.eq
#align roots_of_unity.coe_injective rootsOfUnity.coe_injective
@[simps! coe_val]
def rootsOfUnity.mkOfPowEq (ζ : M) {n : ℕ+} (h : ζ ^ (n : ℕ) = 1) : rootsOfUnity n M :=
⟨Units.ofPowEqOne ζ n h n.ne_zero, Units.pow_ofPowEqOne _ _⟩
#align roots_of_unity.mk_of_pow_eq rootsOfUnity.mkOfPowEq
#align roots_of_unity.mk_of_pow_eq_coe_coe rootsOfUnity.val_mkOfPowEq_coe
@[simp]
theorem rootsOfUnity.coe_mkOfPowEq {ζ : M} {n : ℕ+} (h : ζ ^ (n : ℕ) = 1) :
((rootsOfUnity.mkOfPowEq _ h : Mˣ) : M) = ζ :=
rfl
#align roots_of_unity.coe_mk_of_pow_eq rootsOfUnity.coe_mkOfPowEq
theorem rootsOfUnity_le_of_dvd (h : k ∣ l) : rootsOfUnity k M ≤ rootsOfUnity l M := by
obtain ⟨d, rfl⟩ := h
intro ζ h
simp_all only [mem_rootsOfUnity, PNat.mul_coe, pow_mul, one_pow]
#align roots_of_unity_le_of_dvd rootsOfUnity_le_of_dvd
theorem map_rootsOfUnity (f : Mˣ →* Nˣ) (k : ℕ+) : (rootsOfUnity k M).map f ≤ rootsOfUnity k N := by
rintro _ ⟨ζ, h, rfl⟩
simp_all only [← map_pow, mem_rootsOfUnity, SetLike.mem_coe, MonoidHom.map_one]
#align map_roots_of_unity map_rootsOfUnity
@[norm_cast]
theorem rootsOfUnity.coe_pow [CommMonoid R] (ζ : rootsOfUnity k R) (m : ℕ) :
(((ζ ^ m :) : Rˣ) : R) = ((ζ : Rˣ) : R) ^ m := by
rw [Subgroup.coe_pow, Units.val_pow_eq_pow_val]
#align roots_of_unity.coe_pow rootsOfUnity.coe_pow
@[mk_iff IsPrimitiveRoot.iff_def]
structure IsPrimitiveRoot (ζ : M) (k : ℕ) : Prop where
pow_eq_one : ζ ^ (k : ℕ) = 1
dvd_of_pow_eq_one : ∀ l : ℕ, ζ ^ l = 1 → k ∣ l
#align is_primitive_root IsPrimitiveRoot
#align is_primitive_root.iff_def IsPrimitiveRoot.iff_def
@[simps!]
def IsPrimitiveRoot.toRootsOfUnity {μ : M} {n : ℕ+} (h : IsPrimitiveRoot μ n) : rootsOfUnity n M :=
rootsOfUnity.mkOfPowEq μ h.pow_eq_one
#align is_primitive_root.to_roots_of_unity IsPrimitiveRoot.toRootsOfUnity
#align is_primitive_root.coe_to_roots_of_unity_coe IsPrimitiveRoot.val_toRootsOfUnity_coe
#align is_primitive_root.coe_inv_to_roots_of_unity_coe IsPrimitiveRoot.val_inv_toRootsOfUnity_coe
namespace IsPrimitiveRoot
variable {k l : ℕ}
theorem mk_of_lt (ζ : M) (hk : 0 < k) (h1 : ζ ^ k = 1) (h : ∀ l : ℕ, 0 < l → l < k → ζ ^ l ≠ 1) :
IsPrimitiveRoot ζ k := by
refine ⟨h1, fun l hl => ?_⟩
suffices k.gcd l = k by exact this ▸ k.gcd_dvd_right l
rw [eq_iff_le_not_lt]
refine ⟨Nat.le_of_dvd hk (k.gcd_dvd_left l), ?_⟩
intro h'; apply h _ (Nat.gcd_pos_of_pos_left _ hk) h'
exact pow_gcd_eq_one _ h1 hl
#align is_primitive_root.mk_of_lt IsPrimitiveRoot.mk_of_lt
section CommMonoid
variable {ζ : M} {f : F} (h : IsPrimitiveRoot ζ k)
@[nontriviality]
theorem of_subsingleton [Subsingleton M] (x : M) : IsPrimitiveRoot x 1 :=
⟨Subsingleton.elim _ _, fun _ _ => one_dvd _⟩
#align is_primitive_root.of_subsingleton IsPrimitiveRoot.of_subsingleton
theorem pow_eq_one_iff_dvd (l : ℕ) : ζ ^ l = 1 ↔ k ∣ l :=
⟨h.dvd_of_pow_eq_one l, by
rintro ⟨i, rfl⟩; simp only [pow_mul, h.pow_eq_one, one_pow, PNat.mul_coe]⟩
#align is_primitive_root.pow_eq_one_iff_dvd IsPrimitiveRoot.pow_eq_one_iff_dvd
theorem isUnit (h : IsPrimitiveRoot ζ k) (h0 : 0 < k) : IsUnit ζ := by
apply isUnit_of_mul_eq_one ζ (ζ ^ (k - 1))
rw [← pow_succ', tsub_add_cancel_of_le h0.nat_succ_le, h.pow_eq_one]
#align is_primitive_root.is_unit IsPrimitiveRoot.isUnit
theorem pow_ne_one_of_pos_of_lt (h0 : 0 < l) (hl : l < k) : ζ ^ l ≠ 1 :=
mt (Nat.le_of_dvd h0 ∘ h.dvd_of_pow_eq_one _) <| not_le_of_lt hl
#align is_primitive_root.pow_ne_one_of_pos_of_lt IsPrimitiveRoot.pow_ne_one_of_pos_of_lt
theorem ne_one (hk : 1 < k) : ζ ≠ 1 :=
h.pow_ne_one_of_pos_of_lt zero_lt_one hk ∘ (pow_one ζ).trans
#align is_primitive_root.ne_one IsPrimitiveRoot.ne_one
theorem pow_inj (h : IsPrimitiveRoot ζ k) ⦃i j : ℕ⦄ (hi : i < k) (hj : j < k) (H : ζ ^ i = ζ ^ j) :
i = j := by
wlog hij : i ≤ j generalizing i j
· exact (this hj hi H.symm (le_of_not_le hij)).symm
apply le_antisymm hij
rw [← tsub_eq_zero_iff_le]
apply Nat.eq_zero_of_dvd_of_lt _ (lt_of_le_of_lt tsub_le_self hj)
apply h.dvd_of_pow_eq_one
rw [← ((h.isUnit (lt_of_le_of_lt (Nat.zero_le _) hi)).pow i).mul_left_inj, ← pow_add,
tsub_add_cancel_of_le hij, H, one_mul]
#align is_primitive_root.pow_inj IsPrimitiveRoot.pow_inj
theorem one : IsPrimitiveRoot (1 : M) 1 :=
{ pow_eq_one := pow_one _
dvd_of_pow_eq_one := fun _ _ => one_dvd _ }
#align is_primitive_root.one IsPrimitiveRoot.one
@[simp]
| Mathlib/RingTheory/RootsOfUnity/Basic.lean | 390 | 394 | theorem one_right_iff : IsPrimitiveRoot ζ 1 ↔ ζ = 1 := by |
clear h
constructor
· intro h; rw [← pow_one ζ, h.pow_eq_one]
· rintro rfl; exact one
|
import Mathlib.Order.Filter.EventuallyConst
import Mathlib.Order.PartialSups
import Mathlib.Algebra.Module.Submodule.IterateMapComap
import Mathlib.RingTheory.OrzechProperty
import Mathlib.RingTheory.Nilpotent.Lemmas
#align_import ring_theory.noetherian from "leanprover-community/mathlib"@"210657c4ea4a4a7b234392f70a3a2a83346dfa90"
open Set Filter Pointwise
-- Porting note: should this be renamed to `Noetherian`?
class IsNoetherian (R M) [Semiring R] [AddCommMonoid M] [Module R M] : Prop where
noetherian : ∀ s : Submodule R M, s.FG
#align is_noetherian IsNoetherian
attribute [inherit_doc IsNoetherian] IsNoetherian.noetherian
section
variable {R : Type*} {M : Type*} {P : Type*}
variable [Semiring R] [AddCommMonoid M] [AddCommMonoid P]
variable [Module R M] [Module R P]
open IsNoetherian
theorem isNoetherian_def : IsNoetherian R M ↔ ∀ s : Submodule R M, s.FG :=
⟨fun h => h.noetherian, IsNoetherian.mk⟩
#align is_noetherian_def isNoetherian_def
theorem isNoetherian_submodule {N : Submodule R M} :
IsNoetherian R N ↔ ∀ s : Submodule R M, s ≤ N → s.FG := by
refine ⟨fun ⟨hn⟩ => fun s hs =>
have : s ≤ LinearMap.range N.subtype := N.range_subtype.symm ▸ hs
Submodule.map_comap_eq_self this ▸ (hn _).map _,
fun h => ⟨fun s => ?_⟩⟩
have f := (Submodule.equivMapOfInjective N.subtype Subtype.val_injective s).symm
have h₁ := h (s.map N.subtype) (Submodule.map_subtype_le N s)
have h₂ : (⊤ : Submodule R (s.map N.subtype)).map f = ⊤ := by simp
have h₃ := ((Submodule.fg_top _).2 h₁).map (↑f : _ →ₗ[R] s)
exact (Submodule.fg_top _).1 (h₂ ▸ h₃)
#align is_noetherian_submodule isNoetherian_submodule
theorem isNoetherian_submodule_left {N : Submodule R M} :
IsNoetherian R N ↔ ∀ s : Submodule R M, (N ⊓ s).FG :=
isNoetherian_submodule.trans ⟨fun H _ => H _ inf_le_left, fun H _ hs => inf_of_le_right hs ▸ H _⟩
#align is_noetherian_submodule_left isNoetherian_submodule_left
theorem isNoetherian_submodule_right {N : Submodule R M} :
IsNoetherian R N ↔ ∀ s : Submodule R M, (s ⊓ N).FG :=
isNoetherian_submodule.trans ⟨fun H _ => H _ inf_le_right, fun H _ hs => inf_of_le_left hs ▸ H _⟩
#align is_noetherian_submodule_right isNoetherian_submodule_right
instance isNoetherian_submodule' [IsNoetherian R M] (N : Submodule R M) : IsNoetherian R N :=
isNoetherian_submodule.2 fun _ _ => IsNoetherian.noetherian _
#align is_noetherian_submodule' isNoetherian_submodule'
theorem isNoetherian_of_le {s t : Submodule R M} [ht : IsNoetherian R t] (h : s ≤ t) :
IsNoetherian R s :=
isNoetherian_submodule.mpr fun _ hs' => isNoetherian_submodule.mp ht _ (le_trans hs' h)
#align is_noetherian_of_le isNoetherian_of_le
variable (M)
theorem isNoetherian_of_surjective (f : M →ₗ[R] P) (hf : LinearMap.range f = ⊤) [IsNoetherian R M] :
IsNoetherian R P :=
⟨fun s =>
have : (s.comap f).map f = s := Submodule.map_comap_eq_self <| hf.symm ▸ le_top
this ▸ (noetherian _).map _⟩
#align is_noetherian_of_surjective isNoetherian_of_surjective
variable {M}
instance isNoetherian_quotient {R} [Ring R] {M} [AddCommGroup M] [Module R M]
(N : Submodule R M) [IsNoetherian R M] : IsNoetherian R (M ⧸ N) :=
isNoetherian_of_surjective _ _ (LinearMap.range_eq_top.mpr N.mkQ_surjective)
#align submodule.quotient.is_noetherian isNoetherian_quotient
@[deprecated (since := "2024-04-27"), nolint defLemma]
alias Submodule.Quotient.isNoetherian := isNoetherian_quotient
theorem isNoetherian_of_linearEquiv (f : M ≃ₗ[R] P) [IsNoetherian R M] : IsNoetherian R P :=
isNoetherian_of_surjective _ f.toLinearMap f.range
#align is_noetherian_of_linear_equiv isNoetherian_of_linearEquiv
theorem isNoetherian_top_iff : IsNoetherian R (⊤ : Submodule R M) ↔ IsNoetherian R M := by
constructor <;> intro h
· exact isNoetherian_of_linearEquiv (LinearEquiv.ofTop (⊤ : Submodule R M) rfl)
· exact isNoetherian_of_linearEquiv (LinearEquiv.ofTop (⊤ : Submodule R M) rfl).symm
#align is_noetherian_top_iff isNoetherian_top_iff
theorem isNoetherian_of_injective [IsNoetherian R P] (f : M →ₗ[R] P) (hf : Function.Injective f) :
IsNoetherian R M :=
isNoetherian_of_linearEquiv (LinearEquiv.ofInjective f hf).symm
#align is_noetherian_of_injective isNoetherian_of_injective
theorem fg_of_injective [IsNoetherian R P] {N : Submodule R M} (f : M →ₗ[R] P)
(hf : Function.Injective f) : N.FG :=
haveI := isNoetherian_of_injective f hf
IsNoetherian.noetherian N
#align fg_of_injective fg_of_injective
end
section
variable {R : Type*} {M : Type*} {P : Type*}
variable [Ring R] [AddCommGroup M] [AddCommGroup P]
variable [Module R M] [Module R P]
open IsNoetherian
theorem isNoetherian_of_ker_bot [IsNoetherian R P] (f : M →ₗ[R] P) (hf : LinearMap.ker f = ⊥) :
IsNoetherian R M :=
isNoetherian_of_linearEquiv (LinearEquiv.ofInjective f <| LinearMap.ker_eq_bot.mp hf).symm
#align is_noetherian_of_ker_bot isNoetherian_of_ker_bot
theorem fg_of_ker_bot [IsNoetherian R P] {N : Submodule R M} (f : M →ₗ[R] P)
(hf : LinearMap.ker f = ⊥) : N.FG :=
haveI := isNoetherian_of_ker_bot f hf
IsNoetherian.noetherian N
#align fg_of_ker_bot fg_of_ker_bot
instance isNoetherian_prod [IsNoetherian R M] [IsNoetherian R P] : IsNoetherian R (M × P) :=
⟨fun s =>
Submodule.fg_of_fg_map_of_fg_inf_ker (LinearMap.snd R M P) (noetherian _) <|
have : s ⊓ LinearMap.ker (LinearMap.snd R M P) ≤ LinearMap.range (LinearMap.inl R M P) :=
fun x ⟨_, hx2⟩ => ⟨x.1, Prod.ext rfl <| Eq.symm <| LinearMap.mem_ker.1 hx2⟩
Submodule.map_comap_eq_self this ▸ (noetherian _).map _⟩
#align is_noetherian_prod isNoetherian_prod
instance isNoetherian_pi {R ι : Type*} {M : ι → Type*}
[Ring R] [∀ i, AddCommGroup (M i)] [∀ i, Module R (M i)] [Finite ι]
[∀ i, IsNoetherian R (M i)] : IsNoetherian R (∀ i, M i) := by
cases nonempty_fintype ι
haveI := Classical.decEq ι
suffices on_finset : ∀ s : Finset ι, IsNoetherian R (∀ i : s, M i) by
let coe_e := Equiv.subtypeUnivEquiv <| @Finset.mem_univ ι _
letI : IsNoetherian R (∀ i : Finset.univ, M (coe_e i)) := on_finset Finset.univ
exact isNoetherian_of_linearEquiv (LinearEquiv.piCongrLeft R M coe_e)
intro s
induction' s using Finset.induction with a s has ih
· exact ⟨fun s => by
have : s = ⊥ := by simp only [eq_iff_true_of_subsingleton]
rw [this]
apply Submodule.fg_bot⟩
refine
@isNoetherian_of_linearEquiv R (M a × ((i : s) → M i)) _ _ _ _ _ _ ?_ <|
@isNoetherian_prod R (M a) _ _ _ _ _ _ _ ih
refine
{ toFun := fun f i =>
(Finset.mem_insert.1 i.2).by_cases
(fun h : i.1 = a => show M i.1 from Eq.recOn h.symm f.1)
(fun h : i.1 ∈ s => show M i.1 from f.2 ⟨i.1, h⟩),
invFun := fun f =>
(f ⟨a, Finset.mem_insert_self _ _⟩, fun i => f ⟨i.1, Finset.mem_insert_of_mem i.2⟩),
map_add' := ?_,
map_smul' := ?_
left_inv := ?_,
right_inv := ?_ }
· intro f g
ext i
unfold Or.by_cases
cases' i with i hi
rcases Finset.mem_insert.1 hi with (rfl | h)
· change _ = _ + _
simp only [dif_pos]
rfl
· change _ = _ + _
have : ¬i = a := by
rintro rfl
exact has h
simp only [dif_neg this, dif_pos h]
rfl
· intro c f
ext i
unfold Or.by_cases
cases' i with i hi
rcases Finset.mem_insert.1 hi with (rfl | h)
· dsimp
simp only [dif_pos]
· dsimp
have : ¬i = a := by
rintro rfl
exact has h
simp only [dif_neg this, dif_pos h]
· intro f
apply Prod.ext
· simp only [Or.by_cases, dif_pos]
· ext ⟨i, his⟩
have : ¬i = a := by
rintro rfl
exact has his
simp only [Or.by_cases, this, not_false_iff, dif_neg]
· intro f
ext ⟨i, hi⟩
rcases Finset.mem_insert.1 hi with (rfl | h)
· simp only [Or.by_cases, dif_pos]
· have : ¬i = a := by
rintro rfl
exact has h
simp only [Or.by_cases, dif_neg this, dif_pos h]
#align is_noetherian_pi isNoetherian_pi
instance isNoetherian_pi' {R ι M : Type*} [Ring R] [AddCommGroup M] [Module R M] [Finite ι]
[IsNoetherian R M] : IsNoetherian R (ι → M) :=
isNoetherian_pi
#align is_noetherian_pi' isNoetherian_pi'
end
open IsNoetherian Submodule Function
section
universe w
variable {R M P : Type*} {N : Type w} [Semiring R] [AddCommMonoid M] [Module R M] [AddCommMonoid N]
[Module R N] [AddCommMonoid P] [Module R P]
theorem isNoetherian_iff_wellFounded :
IsNoetherian R M ↔ WellFounded ((· > ·) : Submodule R M → Submodule R M → Prop) := by
have := (CompleteLattice.wellFounded_characterisations <| Submodule R M).out 0 3
-- Porting note: inlining this makes rw complain about it being a metavariable
rw [this]
exact
⟨fun ⟨h⟩ => fun k => (fg_iff_compact k).mp (h k), fun h =>
⟨fun k => (fg_iff_compact k).mpr (h k)⟩⟩
#align is_noetherian_iff_well_founded isNoetherian_iff_wellFounded
theorem isNoetherian_iff_fg_wellFounded :
IsNoetherian R M ↔
WellFounded
((· > ·) : { N : Submodule R M // N.FG } → { N : Submodule R M // N.FG } → Prop) := by
let α := { N : Submodule R M // N.FG }
constructor
· intro H
let f : α ↪o Submodule R M := OrderEmbedding.subtype _
exact OrderEmbedding.wellFounded f.dual (isNoetherian_iff_wellFounded.mp H)
· intro H
constructor
intro N
obtain ⟨⟨N₀, h₁⟩, e : N₀ ≤ N, h₂⟩ :=
WellFounded.has_min H { N' : α | N'.1 ≤ N } ⟨⟨⊥, Submodule.fg_bot⟩, @bot_le _ _ _ N⟩
convert h₁
refine (e.antisymm ?_).symm
by_contra h₃
obtain ⟨x, hx₁ : x ∈ N, hx₂ : x ∉ N₀⟩ := Set.not_subset.mp h₃
apply hx₂
rw [eq_of_le_of_not_lt (le_sup_right : N₀ ≤ _) (h₂
⟨_, Submodule.FG.sup ⟨{x}, by rw [Finset.coe_singleton]⟩ h₁⟩ <|
sup_le ((Submodule.span_singleton_le_iff_mem _ _).mpr hx₁) e)]
exact (le_sup_left : (R ∙ x) ≤ _) (Submodule.mem_span_singleton_self _)
#align is_noetherian_iff_fg_well_founded isNoetherian_iff_fg_wellFounded
variable (R M)
theorem wellFounded_submodule_gt (R M) [Semiring R] [AddCommMonoid M] [Module R M] :
∀ [IsNoetherian R M], WellFounded ((· > ·) : Submodule R M → Submodule R M → Prop) :=
isNoetherian_iff_wellFounded.mp ‹_›
#align well_founded_submodule_gt wellFounded_submodule_gt
variable {R M}
theorem set_has_maximal_iff_noetherian :
(∀ a : Set <| Submodule R M, a.Nonempty → ∃ M' ∈ a, ∀ I ∈ a, ¬M' < I) ↔ IsNoetherian R M := by
rw [isNoetherian_iff_wellFounded, WellFounded.wellFounded_iff_has_min]
#align set_has_maximal_iff_noetherian set_has_maximal_iff_noetherian
theorem monotone_stabilizes_iff_noetherian :
(∀ f : ℕ →o Submodule R M, ∃ n, ∀ m, n ≤ m → f n = f m) ↔ IsNoetherian R M := by
rw [isNoetherian_iff_wellFounded, WellFounded.monotone_chain_condition]
#align monotone_stabilizes_iff_noetherian monotone_stabilizes_iff_noetherian
theorem eventuallyConst_of_isNoetherian [IsNoetherian R M] (f : ℕ →o Submodule R M) :
atTop.EventuallyConst f := by
simp_rw [eventuallyConst_atTop, eq_comm]
exact (monotone_stabilizes_iff_noetherian.mpr inferInstance) f
theorem IsNoetherian.induction [IsNoetherian R M] {P : Submodule R M → Prop}
(hgt : ∀ I, (∀ J > I, P J) → P I) (I : Submodule R M) : P I :=
WellFounded.recursion (wellFounded_submodule_gt R M) I hgt
#align is_noetherian.induction IsNoetherian.induction
end
section
universe w
variable {R M P : Type*} {N : Type w} [Ring R] [AddCommGroup M] [Module R M] [AddCommGroup N]
[Module R N] [AddCommGroup P] [Module R P] [IsNoetherian R M]
lemma Submodule.finite_ne_bot_of_independent {ι : Type*} {N : ι → Submodule R M}
(h : CompleteLattice.Independent N) :
Set.Finite {i | N i ≠ ⊥} :=
CompleteLattice.WellFounded.finite_ne_bot_of_independent
(isNoetherian_iff_wellFounded.mp inferInstance) h
theorem LinearIndependent.finite_of_isNoetherian [Nontrivial R] {ι} {v : ι → M}
(hv : LinearIndependent R v) : Finite ι := by
have hwf := isNoetherian_iff_wellFounded.mp (by infer_instance : IsNoetherian R M)
refine CompleteLattice.WellFounded.finite_of_independent hwf hv.independent_span_singleton
fun i contra => ?_
apply hv.ne_zero i
have : v i ∈ R ∙ v i := Submodule.mem_span_singleton_self (v i)
rwa [contra, Submodule.mem_bot] at this
#align linear_independent.finite_of_is_noetherian LinearIndependent.finite_of_isNoetherian
theorem LinearIndependent.set_finite_of_isNoetherian [Nontrivial R] {s : Set M}
(hi : LinearIndependent R ((↑) : s → M)) : s.Finite :=
@Set.toFinite _ _ hi.finite_of_isNoetherian
#align linear_independent.set_finite_of_is_noetherian LinearIndependent.set_finite_of_isNoetherian
@[deprecated]
alias finite_of_linearIndependent := LinearIndependent.set_finite_of_isNoetherian
#align finite_of_linear_independent LinearIndependent.set_finite_of_isNoetherian
theorem isNoetherian_of_range_eq_ker [IsNoetherian R P]
(f : M →ₗ[R] N) (g : N →ₗ[R] P) (h : LinearMap.range f = LinearMap.ker g) :
IsNoetherian R N :=
isNoetherian_iff_wellFounded.2 <|
wellFounded_gt_exact_sequence
(wellFounded_submodule_gt R _) (wellFounded_submodule_gt R _)
(LinearMap.range f)
(Submodule.map (f.ker.liftQ f <| le_rfl))
(Submodule.comap (f.ker.liftQ f <| le_rfl))
(Submodule.comap g.rangeRestrict) (Submodule.map g.rangeRestrict)
(Submodule.gciMapComap <| LinearMap.ker_eq_bot.mp <|
Submodule.ker_liftQ_eq_bot _ _ _ (le_refl _))
(Submodule.giMapComap g.surjective_rangeRestrict)
(by simp [Submodule.map_comap_eq, inf_comm, Submodule.range_liftQ])
(by simp [Submodule.comap_map_eq, h])
#align is_noetherian_of_range_eq_ker isNoetherian_of_range_eq_ker
| Mathlib/RingTheory/Noetherian.lean | 438 | 448 | theorem LinearMap.eventually_disjoint_ker_pow_range_pow (f : M →ₗ[R] M) :
∀ᶠ n in atTop, Disjoint (LinearMap.ker (f ^ n)) (LinearMap.range (f ^ n)) := by |
obtain ⟨n, hn : ∀ m, n ≤ m → LinearMap.ker (f ^ n) = LinearMap.ker (f ^ m)⟩ :=
monotone_stabilizes_iff_noetherian.mpr inferInstance f.iterateKer
refine eventually_atTop.mpr ⟨n, fun m hm ↦ disjoint_iff.mpr ?_⟩
rw [← hn _ hm, Submodule.eq_bot_iff]
rintro - ⟨hx, ⟨x, rfl⟩⟩
apply LinearMap.pow_map_zero_of_le hm
replace hx : x ∈ LinearMap.ker (f ^ (n + m)) := by
simpa [f.pow_apply n, f.pow_apply m, ← f.pow_apply (n + m), ← iterate_add_apply] using hx
rwa [← hn _ (n.le_add_right m)] at hx
|
import Mathlib.LinearAlgebra.Matrix.BilinearForm
import Mathlib.LinearAlgebra.Matrix.Charpoly.Minpoly
import Mathlib.LinearAlgebra.Determinant
import Mathlib.LinearAlgebra.FiniteDimensional
import Mathlib.LinearAlgebra.Vandermonde
import Mathlib.LinearAlgebra.Trace
import Mathlib.FieldTheory.IsAlgClosed.AlgebraicClosure
import Mathlib.FieldTheory.PrimitiveElement
import Mathlib.FieldTheory.Galois
import Mathlib.RingTheory.PowerBasis
import Mathlib.FieldTheory.Minpoly.MinpolyDiv
#align_import ring_theory.trace from "leanprover-community/mathlib"@"3e068ece210655b7b9a9477c3aff38a492400aa1"
universe u v w z
variable {R S T : Type*} [CommRing R] [CommRing S] [CommRing T]
variable [Algebra R S] [Algebra R T]
variable {K L : Type*} [Field K] [Field L] [Algebra K L]
variable {ι κ : Type w} [Fintype ι]
open FiniteDimensional
open LinearMap (BilinForm)
open LinearMap
open Matrix
open scoped Matrix
namespace Algebra
variable (b : Basis ι R S)
variable (R S)
noncomputable def trace : S →ₗ[R] R :=
(LinearMap.trace R S).comp (lmul R S).toLinearMap
#align algebra.trace Algebra.trace
variable {S}
-- Not a `simp` lemma since there are more interesting ways to rewrite `trace R S x`,
-- for example `trace_trace`
theorem trace_apply (x) : trace R S x = LinearMap.trace R S (lmul R S x) :=
rfl
#align algebra.trace_apply Algebra.trace_apply
theorem trace_eq_zero_of_not_exists_basis (h : ¬∃ s : Finset S, Nonempty (Basis s R S)) :
trace R S = 0 := by ext s; simp [trace_apply, LinearMap.trace, h]
#align algebra.trace_eq_zero_of_not_exists_basis Algebra.trace_eq_zero_of_not_exists_basis
variable {R}
-- Can't be a `simp` lemma because it depends on a choice of basis
theorem trace_eq_matrix_trace [DecidableEq ι] (b : Basis ι R S) (s : S) :
trace R S s = Matrix.trace (Algebra.leftMulMatrix b s) := by
rw [trace_apply, LinearMap.trace_eq_matrix_trace _ b, ← toMatrix_lmul_eq]; rfl
#align algebra.trace_eq_matrix_trace Algebra.trace_eq_matrix_trace
theorem trace_algebraMap_of_basis (x : R) : trace R S (algebraMap R S x) = Fintype.card ι • x := by
haveI := Classical.decEq ι
rw [trace_apply, LinearMap.trace_eq_matrix_trace R b, Matrix.trace]
convert Finset.sum_const x
simp [-coe_lmul_eq_mul]
#align algebra.trace_algebra_map_of_basis Algebra.trace_algebraMap_of_basis
@[simp]
theorem trace_algebraMap (x : K) : trace K L (algebraMap K L x) = finrank K L • x := by
by_cases H : ∃ s : Finset L, Nonempty (Basis s K L)
· rw [trace_algebraMap_of_basis H.choose_spec.some, finrank_eq_card_basis H.choose_spec.some]
· simp [trace_eq_zero_of_not_exists_basis K H, finrank_eq_zero_of_not_exists_basis_finset H]
#align algebra.trace_algebra_map Algebra.trace_algebraMap
theorem trace_trace_of_basis [Algebra S T] [IsScalarTower R S T] {ι κ : Type*} [Finite ι]
[Finite κ] (b : Basis ι R S) (c : Basis κ S T) (x : T) :
trace R S (trace S T x) = trace R T x := by
haveI := Classical.decEq ι
haveI := Classical.decEq κ
cases nonempty_fintype ι
cases nonempty_fintype κ
rw [trace_eq_matrix_trace (b.smul c), trace_eq_matrix_trace b, trace_eq_matrix_trace c,
Matrix.trace, Matrix.trace, Matrix.trace, ← Finset.univ_product_univ, Finset.sum_product]
refine Finset.sum_congr rfl fun i _ ↦ ?_
simp only [AlgHom.map_sum, smul_leftMulMatrix, Finset.sum_apply,
Matrix.diag, Finset.sum_apply
i (Finset.univ : Finset κ) fun y => leftMulMatrix b (leftMulMatrix c x y y)]
#align algebra.trace_trace_of_basis Algebra.trace_trace_of_basis
theorem trace_comp_trace_of_basis [Algebra S T] [IsScalarTower R S T] {ι κ : Type*} [Finite ι]
[Finite κ] (b : Basis ι R S) (c : Basis κ S T) :
(trace R S).comp ((trace S T).restrictScalars R) = trace R T := by
ext
rw [LinearMap.comp_apply, LinearMap.restrictScalars_apply, trace_trace_of_basis b c]
#align algebra.trace_comp_trace_of_basis Algebra.trace_comp_trace_of_basis
@[simp]
theorem trace_trace [Algebra K T] [Algebra L T] [IsScalarTower K L T] [FiniteDimensional K L]
[FiniteDimensional L T] (x : T) : trace K L (trace L T x) = trace K T x :=
trace_trace_of_basis (Basis.ofVectorSpace K L) (Basis.ofVectorSpace L T) x
#align algebra.trace_trace Algebra.trace_trace
@[simp]
theorem trace_comp_trace [Algebra K T] [Algebra L T] [IsScalarTower K L T] [FiniteDimensional K L]
[FiniteDimensional L T] : (trace K L).comp ((trace L T).restrictScalars K) = trace K T := by
ext; rw [LinearMap.comp_apply, LinearMap.restrictScalars_apply, trace_trace]
#align algebra.trace_comp_trace Algebra.trace_comp_trace
@[simp]
theorem trace_prod_apply [Module.Free R S] [Module.Free R T] [Module.Finite R S] [Module.Finite R T]
(x : S × T) : trace R (S × T) x = trace R S x.fst + trace R T x.snd := by
nontriviality R
let f := (lmul R S).toLinearMap.prodMap (lmul R T).toLinearMap
have : (lmul R (S × T)).toLinearMap = (prodMapLinear R S T S T R).comp f :=
LinearMap.ext₂ Prod.mul_def
simp_rw [trace, this]
exact trace_prodMap' _ _
#align algebra.trace_prod_apply Algebra.trace_prod_apply
theorem trace_prod [Module.Free R S] [Module.Free R T] [Module.Finite R S] [Module.Finite R T] :
trace R (S × T) = (trace R S).coprod (trace R T) :=
LinearMap.ext fun p => by rw [coprod_apply, trace_prod_apply]
#align algebra.trace_prod Algebra.trace_prod
section TraceForm
variable (R S)
noncomputable def traceForm : BilinForm R S :=
LinearMap.compr₂ (lmul R S).toLinearMap (trace R S)
#align algebra.trace_form Algebra.traceForm
variable {S}
-- This is a nicer lemma than the one produced by `@[simps] def traceForm`.
@[simp]
theorem traceForm_apply (x y : S) : traceForm R S x y = trace R S (x * y) :=
rfl
#align algebra.trace_form_apply Algebra.traceForm_apply
theorem traceForm_isSymm : (traceForm R S).IsSymm := fun _ _ => congr_arg (trace R S) (mul_comm _ _)
#align algebra.trace_form_is_symm Algebra.traceForm_isSymm
theorem traceForm_toMatrix [DecidableEq ι] (i j) :
BilinForm.toMatrix b (traceForm R S) i j = trace R S (b i * b j) := by
rw [BilinForm.toMatrix_apply, traceForm_apply]
#align algebra.trace_form_to_matrix Algebra.traceForm_toMatrix
| Mathlib/RingTheory/Trace.lean | 210 | 212 | theorem traceForm_toMatrix_powerBasis (h : PowerBasis R S) :
BilinForm.toMatrix h.basis (traceForm R S) = of fun i j => trace R S (h.gen ^ (i.1 + j.1)) := by |
ext; rw [traceForm_toMatrix, of_apply, pow_add, h.basis_eq_pow, h.basis_eq_pow]
|
import Mathlib.Analysis.Calculus.BumpFunction.Basic
import Mathlib.MeasureTheory.Integral.SetIntegral
import Mathlib.MeasureTheory.Measure.Lebesgue.EqHaar
#align_import analysis.calculus.bump_function_inner from "leanprover-community/mathlib"@"3bce8d800a6f2b8f63fe1e588fd76a9ff4adcebe"
noncomputable section
open Function Filter Set Metric MeasureTheory FiniteDimensional Measure
open scoped Topology
namespace ContDiffBump
variable {E : Type*} [NormedAddCommGroup E] [NormedSpace ℝ E] [HasContDiffBump E]
[MeasurableSpace E] {c : E} (f : ContDiffBump c) {x : E} {n : ℕ∞} {μ : Measure E}
protected def normed (μ : Measure E) : E → ℝ := fun x => f x / ∫ x, f x ∂μ
#align cont_diff_bump.normed ContDiffBump.normed
theorem normed_def {μ : Measure E} (x : E) : f.normed μ x = f x / ∫ x, f x ∂μ :=
rfl
#align cont_diff_bump.normed_def ContDiffBump.normed_def
theorem nonneg_normed (x : E) : 0 ≤ f.normed μ x :=
div_nonneg f.nonneg <| integral_nonneg f.nonneg'
#align cont_diff_bump.nonneg_normed ContDiffBump.nonneg_normed
theorem contDiff_normed {n : ℕ∞} : ContDiff ℝ n (f.normed μ) :=
f.contDiff.div_const _
#align cont_diff_bump.cont_diff_normed ContDiffBump.contDiff_normed
theorem continuous_normed : Continuous (f.normed μ) :=
f.continuous.div_const _
#align cont_diff_bump.continuous_normed ContDiffBump.continuous_normed
theorem normed_sub (x : E) : f.normed μ (c - x) = f.normed μ (c + x) := by
simp_rw [f.normed_def, f.sub]
#align cont_diff_bump.normed_sub ContDiffBump.normed_sub
theorem normed_neg (f : ContDiffBump (0 : E)) (x : E) : f.normed μ (-x) = f.normed μ x := by
simp_rw [f.normed_def, f.neg]
#align cont_diff_bump.normed_neg ContDiffBump.normed_neg
variable [BorelSpace E] [FiniteDimensional ℝ E] [IsLocallyFiniteMeasure μ]
protected theorem integrable : Integrable f μ :=
f.continuous.integrable_of_hasCompactSupport f.hasCompactSupport
#align cont_diff_bump.integrable ContDiffBump.integrable
protected theorem integrable_normed : Integrable (f.normed μ) μ :=
f.integrable.div_const _
#align cont_diff_bump.integrable_normed ContDiffBump.integrable_normed
variable [μ.IsOpenPosMeasure]
theorem integral_pos : 0 < ∫ x, f x ∂μ := by
refine (integral_pos_iff_support_of_nonneg f.nonneg' f.integrable).mpr ?_
rw [f.support_eq]
exact measure_ball_pos μ c f.rOut_pos
#align cont_diff_bump.integral_pos ContDiffBump.integral_pos
theorem integral_normed : ∫ x, f.normed μ x ∂μ = 1 := by
simp_rw [ContDiffBump.normed, div_eq_mul_inv, mul_comm (f _), ← smul_eq_mul, integral_smul]
exact inv_mul_cancel f.integral_pos.ne'
#align cont_diff_bump.integral_normed ContDiffBump.integral_normed
theorem support_normed_eq : Function.support (f.normed μ) = Metric.ball c f.rOut := by
unfold ContDiffBump.normed
rw [support_div, f.support_eq, support_const f.integral_pos.ne', inter_univ]
#align cont_diff_bump.support_normed_eq ContDiffBump.support_normed_eq
theorem tsupport_normed_eq : tsupport (f.normed μ) = Metric.closedBall c f.rOut := by
rw [tsupport, f.support_normed_eq, closure_ball _ f.rOut_pos.ne']
#align cont_diff_bump.tsupport_normed_eq ContDiffBump.tsupport_normed_eq
theorem hasCompactSupport_normed : HasCompactSupport (f.normed μ) := by
simp only [HasCompactSupport, f.tsupport_normed_eq (μ := μ), isCompact_closedBall]
#align cont_diff_bump.has_compact_support_normed ContDiffBump.hasCompactSupport_normed
theorem tendsto_support_normed_smallSets {ι} {φ : ι → ContDiffBump c} {l : Filter ι}
(hφ : Tendsto (fun i => (φ i).rOut) l (𝓝 0)) :
Tendsto (fun i => Function.support fun x => (φ i).normed μ x) l (𝓝 c).smallSets := by
simp_rw [NormedAddCommGroup.tendsto_nhds_zero, Real.norm_eq_abs,
abs_eq_self.mpr (φ _).rOut_pos.le] at hφ
rw [nhds_basis_ball.smallSets.tendsto_right_iff]
refine fun ε hε ↦ (hφ ε hε).mono fun i hi ↦ ?_
rw [(φ i).support_normed_eq]
exact ball_subset_ball hi.le
#align cont_diff_bump.tendsto_support_normed_small_sets ContDiffBump.tendsto_support_normed_smallSets
variable (μ)
theorem integral_normed_smul {X} [NormedAddCommGroup X] [NormedSpace ℝ X]
[CompleteSpace X] (z : X) : ∫ x, f.normed μ x • z ∂μ = z := by
simp_rw [integral_smul_const, f.integral_normed (μ := μ), one_smul]
#align cont_diff_bump.integral_normed_smul ContDiffBump.integral_normed_smul
| Mathlib/Analysis/Calculus/BumpFunction/Normed.lean | 111 | 115 | theorem measure_closedBall_le_integral : (μ (closedBall c f.rIn)).toReal ≤ ∫ x, f x ∂μ := by | calc
(μ (closedBall c f.rIn)).toReal = ∫ x in closedBall c f.rIn, 1 ∂μ := by simp
_ = ∫ x in closedBall c f.rIn, f x ∂μ := setIntegral_congr measurableSet_closedBall
(fun x hx ↦ (one_of_mem_closedBall f hx).symm)
_ ≤ ∫ x, f x ∂μ := setIntegral_le_integral f.integrable (eventually_of_forall (fun x ↦ f.nonneg))
|
import Mathlib.Algebra.CharP.Two
import Mathlib.Data.Nat.Factorization.Basic
import Mathlib.Data.Nat.Periodic
import Mathlib.Data.ZMod.Basic
import Mathlib.Tactic.Monotonicity
#align_import data.nat.totient from "leanprover-community/mathlib"@"5cc2dfdd3e92f340411acea4427d701dc7ed26f8"
open Finset
namespace Nat
def totient (n : ℕ) : ℕ :=
((range n).filter n.Coprime).card
#align nat.totient Nat.totient
@[inherit_doc]
scoped notation "φ" => Nat.totient
@[simp]
theorem totient_zero : φ 0 = 0 :=
rfl
#align nat.totient_zero Nat.totient_zero
@[simp]
theorem totient_one : φ 1 = 1 := rfl
#align nat.totient_one Nat.totient_one
theorem totient_eq_card_coprime (n : ℕ) : φ n = ((range n).filter n.Coprime).card :=
rfl
#align nat.totient_eq_card_coprime Nat.totient_eq_card_coprime
theorem totient_eq_card_lt_and_coprime (n : ℕ) : φ n = Nat.card { m | m < n ∧ n.Coprime m } := by
let e : { m | m < n ∧ n.Coprime m } ≃ Finset.filter n.Coprime (Finset.range n) :=
{ toFun := fun m => ⟨m, by simpa only [Finset.mem_filter, Finset.mem_range] using m.property⟩
invFun := fun m => ⟨m, by simpa only [Finset.mem_filter, Finset.mem_range] using m.property⟩
left_inv := fun m => by simp only [Subtype.coe_mk, Subtype.coe_eta]
right_inv := fun m => by simp only [Subtype.coe_mk, Subtype.coe_eta] }
rw [totient_eq_card_coprime, card_congr e, card_eq_fintype_card, Fintype.card_coe]
#align nat.totient_eq_card_lt_and_coprime Nat.totient_eq_card_lt_and_coprime
theorem totient_le (n : ℕ) : φ n ≤ n :=
((range n).card_filter_le _).trans_eq (card_range n)
#align nat.totient_le Nat.totient_le
theorem totient_lt (n : ℕ) (hn : 1 < n) : φ n < n :=
(card_lt_card (filter_ssubset.2 ⟨0, by simp [hn.ne', pos_of_gt hn]⟩)).trans_eq (card_range n)
#align nat.totient_lt Nat.totient_lt
@[simp]
theorem totient_eq_zero : ∀ {n : ℕ}, φ n = 0 ↔ n = 0
| 0 => by decide
| n + 1 =>
suffices ∃ x < n + 1, (n + 1).gcd x = 1 by simpa [totient, filter_eq_empty_iff]
⟨1 % (n + 1), mod_lt _ n.succ_pos, by rw [gcd_comm, ← gcd_rec, gcd_one_right]⟩
@[simp] theorem totient_pos {n : ℕ} : 0 < φ n ↔ 0 < n := by simp [pos_iff_ne_zero]
#align nat.totient_pos Nat.totient_pos
theorem filter_coprime_Ico_eq_totient (a n : ℕ) :
((Ico n (n + a)).filter (Coprime a)).card = totient a := by
rw [totient, filter_Ico_card_eq_of_periodic, count_eq_card_filter_range]
exact periodic_coprime a
#align nat.filter_coprime_Ico_eq_totient Nat.filter_coprime_Ico_eq_totient
theorem Ico_filter_coprime_le {a : ℕ} (k n : ℕ) (a_pos : 0 < a) :
((Ico k (k + n)).filter (Coprime a)).card ≤ totient a * (n / a + 1) := by
conv_lhs => rw [← Nat.mod_add_div n a]
induction' n / a with i ih
· rw [← filter_coprime_Ico_eq_totient a k]
simp only [add_zero, mul_one, mul_zero, le_of_lt (mod_lt n a_pos),
Nat.zero_eq, zero_add]
-- Porting note: below line was `mono`
refine Finset.card_mono ?_
refine monotone_filter_left a.Coprime ?_
simp only [Finset.le_eq_subset]
exact Ico_subset_Ico rfl.le (add_le_add_left (le_of_lt (mod_lt n a_pos)) k)
simp only [mul_succ]
simp_rw [← add_assoc] at ih ⊢
calc
(filter a.Coprime (Ico k (k + n % a + a * i + a))).card = (filter a.Coprime
(Ico k (k + n % a + a * i) ∪ Ico (k + n % a + a * i) (k + n % a + a * i + a))).card := by
congr
rw [Ico_union_Ico_eq_Ico]
· rw [add_assoc]
exact le_self_add
exact le_self_add
_ ≤ (filter a.Coprime (Ico k (k + n % a + a * i))).card + a.totient := by
rw [filter_union, ← filter_coprime_Ico_eq_totient a (k + n % a + a * i)]
apply card_union_le
_ ≤ a.totient * i + a.totient + a.totient := add_le_add_right ih (totient a)
#align nat.Ico_filter_coprime_le Nat.Ico_filter_coprime_le
open ZMod
@[simp]
theorem _root_.ZMod.card_units_eq_totient (n : ℕ) [NeZero n] [Fintype (ZMod n)ˣ] :
Fintype.card (ZMod n)ˣ = φ n :=
calc
Fintype.card (ZMod n)ˣ = Fintype.card { x : ZMod n // x.val.Coprime n } :=
Fintype.card_congr ZMod.unitsEquivCoprime
_ = φ n := by
obtain ⟨m, rfl⟩ : ∃ m, n = m + 1 := exists_eq_succ_of_ne_zero NeZero.out
simp only [totient, Finset.card_eq_sum_ones, Fintype.card_subtype, Finset.sum_filter, ←
Fin.sum_univ_eq_sum_range, @Nat.coprime_comm (m + 1)]
rfl
#align zmod.card_units_eq_totient ZMod.card_units_eq_totient
theorem totient_even {n : ℕ} (hn : 2 < n) : Even n.totient := by
haveI : Fact (1 < n) := ⟨one_lt_two.trans hn⟩
haveI : NeZero n := NeZero.of_gt hn
suffices 2 = orderOf (-1 : (ZMod n)ˣ) by
rw [← ZMod.card_units_eq_totient, even_iff_two_dvd, this]
exact orderOf_dvd_card
rw [← orderOf_units, Units.coe_neg_one, orderOf_neg_one, ringChar.eq (ZMod n) n, if_neg hn.ne']
#align nat.totient_even Nat.totient_even
theorem totient_mul {m n : ℕ} (h : m.Coprime n) : φ (m * n) = φ m * φ n :=
if hmn0 : m * n = 0 then by
cases' Nat.mul_eq_zero.1 hmn0 with h h <;>
simp only [totient_zero, mul_zero, zero_mul, h]
else by
haveI : NeZero (m * n) := ⟨hmn0⟩
haveI : NeZero m := ⟨left_ne_zero_of_mul hmn0⟩
haveI : NeZero n := ⟨right_ne_zero_of_mul hmn0⟩
simp only [← ZMod.card_units_eq_totient]
rw [Fintype.card_congr (Units.mapEquiv (ZMod.chineseRemainder h).toMulEquiv).toEquiv,
Fintype.card_congr (@MulEquiv.prodUnits (ZMod m) (ZMod n) _ _).toEquiv, Fintype.card_prod]
#align nat.totient_mul Nat.totient_mul
| Mathlib/Data/Nat/Totient.lean | 152 | 169 | theorem totient_div_of_dvd {n d : ℕ} (hnd : d ∣ n) :
φ (n / d) = (filter (fun k : ℕ => n.gcd k = d) (range n)).card := by |
rcases d.eq_zero_or_pos with (rfl | hd0); · simp [eq_zero_of_zero_dvd hnd]
rcases hnd with ⟨x, rfl⟩
rw [Nat.mul_div_cancel_left x hd0]
apply Finset.card_bij fun k _ => d * k
· simp only [mem_filter, mem_range, and_imp, Coprime]
refine fun a ha1 ha2 => ⟨(mul_lt_mul_left hd0).2 ha1, ?_⟩
rw [gcd_mul_left, ha2, mul_one]
· simp [hd0.ne']
· simp only [mem_filter, mem_range, exists_prop, and_imp]
refine fun b hb1 hb2 => ?_
have : d ∣ b := by
rw [← hb2]
apply gcd_dvd_right
rcases this with ⟨q, rfl⟩
refine ⟨q, ⟨⟨(mul_lt_mul_left hd0).1 hb1, ?_⟩, rfl⟩⟩
rwa [gcd_mul_left, mul_right_eq_self_iff hd0] at hb2
|
import Mathlib.Algebra.Star.SelfAdjoint
import Mathlib.Algebra.Module.Equiv
import Mathlib.LinearAlgebra.Prod
#align_import algebra.star.module from "leanprover-community/mathlib"@"aa6669832974f87406a3d9d70fc5707a60546207"
@[simps]
def starLinearEquiv (R : Type*) {A : Type*} [CommSemiring R] [StarRing R] [AddCommMonoid A]
[StarAddMonoid A] [Module R A] [StarModule R A] : A ≃ₗ⋆[R] A :=
{ starAddEquiv with
toFun := star
map_smul' := star_smul }
#align star_linear_equiv starLinearEquiv
section SelfSkewAdjoint
variable (R : Type*) (A : Type*) [Semiring R] [StarMul R] [TrivialStar R] [AddCommGroup A]
[Module R A] [StarAddMonoid A] [StarModule R A]
def selfAdjoint.submodule : Submodule R A :=
{ selfAdjoint A with smul_mem' := fun _ _ => (IsSelfAdjoint.all _).smul }
#align self_adjoint.submodule selfAdjoint.submodule
def skewAdjoint.submodule : Submodule R A :=
{ skewAdjoint A with smul_mem' := skewAdjoint.smul_mem }
#align skew_adjoint.submodule skewAdjoint.submodule
variable {A} [Invertible (2 : R)]
@[simps]
def selfAdjointPart : A →ₗ[R] selfAdjoint A where
toFun x :=
⟨(⅟ 2 : R) • (x + star x), by
rw [selfAdjoint.mem_iff, star_smul, star_trivial, star_add, star_star, add_comm]⟩
map_add' x y := by
ext
simp [add_add_add_comm]
map_smul' r x := by
ext
simp [← mul_smul, show ⅟ 2 * r = r * ⅟ 2 from Commute.invOf_left <| (2 : ℕ).cast_commute r]
#align self_adjoint_part selfAdjointPart
@[simps]
def skewAdjointPart : A →ₗ[R] skewAdjoint A where
toFun x :=
⟨(⅟ 2 : R) • (x - star x), by
simp only [skewAdjoint.mem_iff, star_smul, star_sub, star_star, star_trivial, ← smul_neg,
neg_sub]⟩
map_add' x y := by
ext
simp only [sub_add, ← smul_add, sub_sub_eq_add_sub, star_add, AddSubgroup.coe_mk,
AddSubgroup.coe_add]
map_smul' r x := by
ext
simp [← mul_smul, ← smul_sub,
show r * ⅟ 2 = ⅟ 2 * r from Commute.invOf_right <| (2 : ℕ).commute_cast r]
#align skew_adjoint_part skewAdjointPart
theorem StarModule.selfAdjointPart_add_skewAdjointPart (x : A) :
(selfAdjointPart R x : A) + skewAdjointPart R x = x := by
simp only [smul_sub, selfAdjointPart_apply_coe, smul_add, skewAdjointPart_apply_coe,
add_add_sub_cancel, invOf_two_smul_add_invOf_two_smul]
#align star_module.self_adjoint_part_add_skew_adjoint_part StarModule.selfAdjointPart_add_skewAdjointPart
| Mathlib/Algebra/Star/Module.lean | 154 | 156 | theorem IsSelfAdjoint.coe_selfAdjointPart_apply {x : A} (hx : IsSelfAdjoint x) :
(selfAdjointPart R x : A) = x := by |
rw [selfAdjointPart_apply_coe, hx.star_eq, smul_add, invOf_two_smul_add_invOf_two_smul]
|
import Mathlib.Analysis.SpecialFunctions.Gamma.Basic
import Mathlib.Analysis.SpecialFunctions.PolarCoord
import Mathlib.Analysis.Convex.Complex
#align_import analysis.special_functions.gaussian from "leanprover-community/mathlib"@"7982767093ae38cba236487f9c9dd9cd99f63c16"
noncomputable section
open Real Set MeasureTheory Filter Asymptotics
open scoped Real Topology
open Complex hiding exp abs_of_nonneg
| Mathlib/Analysis/SpecialFunctions/Gaussian/GaussianIntegral.lean | 31 | 43 | theorem exp_neg_mul_rpow_isLittleO_exp_neg {p b : ℝ} (hb : 0 < b) (hp : 1 < p) :
(fun x : ℝ => exp (- b * x ^ p)) =o[atTop] fun x : ℝ => exp (-x) := by |
rw [isLittleO_exp_comp_exp_comp]
suffices Tendsto (fun x => x * (b * x ^ (p - 1) + -1)) atTop atTop by
refine Tendsto.congr' ?_ this
refine eventuallyEq_of_mem (Ioi_mem_atTop (0 : ℝ)) (fun x hx => ?_)
rw [mem_Ioi] at hx
rw [rpow_sub_one hx.ne']
field_simp [hx.ne']
ring
apply Tendsto.atTop_mul_atTop tendsto_id
refine tendsto_atTop_add_const_right atTop (-1 : ℝ) ?_
exact Tendsto.const_mul_atTop hb (tendsto_rpow_atTop (by linarith))
|
import Mathlib.Topology.UniformSpace.Cauchy
import Mathlib.Topology.UniformSpace.Separation
import Mathlib.Topology.DenseEmbedding
#align_import topology.uniform_space.uniform_embedding from "leanprover-community/mathlib"@"195fcd60ff2bfe392543bceb0ec2adcdb472db4c"
open Filter Function Set Uniformity Topology
section
universe u v w
variable {α : Type u} {β : Type v} {γ : Type w} [UniformSpace α] [UniformSpace β] [UniformSpace γ]
@[mk_iff]
structure UniformInducing (f : α → β) : Prop where
comap_uniformity : comap (fun x : α × α => (f x.1, f x.2)) (𝓤 β) = 𝓤 α
#align uniform_inducing UniformInducing
#align uniform_inducing_iff uniformInducing_iff
lemma uniformInducing_iff_uniformSpace {f : α → β} :
UniformInducing f ↔ ‹UniformSpace β›.comap f = ‹UniformSpace α› := by
rw [uniformInducing_iff, UniformSpace.ext_iff, Filter.ext_iff]
rfl
protected alias ⟨UniformInducing.comap_uniformSpace, _⟩ := uniformInducing_iff_uniformSpace
#align uniform_inducing.comap_uniform_space UniformInducing.comap_uniformSpace
lemma uniformInducing_iff' {f : α → β} :
UniformInducing f ↔ UniformContinuous f ∧ comap (Prod.map f f) (𝓤 β) ≤ 𝓤 α := by
rw [uniformInducing_iff, UniformContinuous, tendsto_iff_comap, le_antisymm_iff, and_comm]; rfl
#align uniform_inducing_iff' uniformInducing_iff'
protected lemma Filter.HasBasis.uniformInducing_iff {ι ι'} {p : ι → Prop} {p' : ι' → Prop} {s s'}
(h : (𝓤 α).HasBasis p s) (h' : (𝓤 β).HasBasis p' s') {f : α → β} :
UniformInducing f ↔
(∀ i, p' i → ∃ j, p j ∧ ∀ x y, (x, y) ∈ s j → (f x, f y) ∈ s' i) ∧
(∀ j, p j → ∃ i, p' i ∧ ∀ x y, (f x, f y) ∈ s' i → (x, y) ∈ s j) := by
simp [uniformInducing_iff', h.uniformContinuous_iff h', (h'.comap _).le_basis_iff h, subset_def]
#align filter.has_basis.uniform_inducing_iff Filter.HasBasis.uniformInducing_iff
theorem UniformInducing.mk' {f : α → β}
(h : ∀ s, s ∈ 𝓤 α ↔ ∃ t ∈ 𝓤 β, ∀ x y : α, (f x, f y) ∈ t → (x, y) ∈ s) : UniformInducing f :=
⟨by simp [eq_comm, Filter.ext_iff, subset_def, h]⟩
#align uniform_inducing.mk' UniformInducing.mk'
theorem uniformInducing_id : UniformInducing (@id α) :=
⟨by rw [← Prod.map_def, Prod.map_id, comap_id]⟩
#align uniform_inducing_id uniformInducing_id
theorem UniformInducing.comp {g : β → γ} (hg : UniformInducing g) {f : α → β}
(hf : UniformInducing f) : UniformInducing (g ∘ f) :=
⟨by rw [← hf.1, ← hg.1, comap_comap]; rfl⟩
#align uniform_inducing.comp UniformInducing.comp
theorem UniformInducing.of_comp_iff {g : β → γ} (hg : UniformInducing g) {f : α → β} :
UniformInducing (g ∘ f) ↔ UniformInducing f := by
refine ⟨fun h ↦ ?_, hg.comp⟩
rw [uniformInducing_iff, ← hg.comap_uniformity, comap_comap, ← h.comap_uniformity,
Function.comp, Function.comp]
theorem UniformInducing.basis_uniformity {f : α → β} (hf : UniformInducing f) {ι : Sort*}
{p : ι → Prop} {s : ι → Set (β × β)} (H : (𝓤 β).HasBasis p s) :
(𝓤 α).HasBasis p fun i => Prod.map f f ⁻¹' s i :=
hf.1 ▸ H.comap _
#align uniform_inducing.basis_uniformity UniformInducing.basis_uniformity
theorem UniformInducing.cauchy_map_iff {f : α → β} (hf : UniformInducing f) {F : Filter α} :
Cauchy (map f F) ↔ Cauchy F := by
simp only [Cauchy, map_neBot_iff, prod_map_map_eq, map_le_iff_le_comap, ← hf.comap_uniformity]
#align uniform_inducing.cauchy_map_iff UniformInducing.cauchy_map_iff
theorem uniformInducing_of_compose {f : α → β} {g : β → γ} (hf : UniformContinuous f)
(hg : UniformContinuous g) (hgf : UniformInducing (g ∘ f)) : UniformInducing f := by
refine ⟨le_antisymm ?_ hf.le_comap⟩
rw [← hgf.1, ← Prod.map_def, ← Prod.map_def, ← Prod.map_comp_map f f g g, ← comap_comap]
exact comap_mono hg.le_comap
#align uniform_inducing_of_compose uniformInducing_of_compose
theorem UniformInducing.uniformContinuous {f : α → β} (hf : UniformInducing f) :
UniformContinuous f := (uniformInducing_iff'.1 hf).1
#align uniform_inducing.uniform_continuous UniformInducing.uniformContinuous
theorem UniformInducing.uniformContinuous_iff {f : α → β} {g : β → γ} (hg : UniformInducing g) :
UniformContinuous f ↔ UniformContinuous (g ∘ f) := by
dsimp only [UniformContinuous, Tendsto]
rw [← hg.comap_uniformity, ← map_le_iff_le_comap, Filter.map_map]; rfl
#align uniform_inducing.uniform_continuous_iff UniformInducing.uniformContinuous_iff
theorem UniformInducing.uniformContinuousOn_iff {f : α → β} {g : β → γ} {S : Set α}
(hg : UniformInducing g) :
UniformContinuousOn f S ↔ UniformContinuousOn (g ∘ f) S := by
dsimp only [UniformContinuousOn, Tendsto]
rw [← hg.comap_uniformity, ← map_le_iff_le_comap, Filter.map_map, comp_def, comp_def]
theorem UniformInducing.inducing {f : α → β} (h : UniformInducing f) : Inducing f := by
obtain rfl := h.comap_uniformSpace
exact inducing_induced f
#align uniform_inducing.inducing UniformInducing.inducing
theorem UniformInducing.prod {α' : Type*} {β' : Type*} [UniformSpace α'] [UniformSpace β']
{e₁ : α → α'} {e₂ : β → β'} (h₁ : UniformInducing e₁) (h₂ : UniformInducing e₂) :
UniformInducing fun p : α × β => (e₁ p.1, e₂ p.2) :=
⟨by simp [(· ∘ ·), uniformity_prod, ← h₁.1, ← h₂.1, comap_inf, comap_comap]⟩
#align uniform_inducing.prod UniformInducing.prod
theorem UniformInducing.denseInducing {f : α → β} (h : UniformInducing f) (hd : DenseRange f) :
DenseInducing f :=
{ dense := hd
induced := h.inducing.induced }
#align uniform_inducing.dense_inducing UniformInducing.denseInducing
theorem SeparationQuotient.uniformInducing_mk : UniformInducing (mk : α → SeparationQuotient α) :=
⟨comap_mk_uniformity⟩
protected theorem UniformInducing.injective [T0Space α] {f : α → β} (h : UniformInducing f) :
Injective f :=
h.inducing.injective
@[mk_iff]
structure UniformEmbedding (f : α → β) extends UniformInducing f : Prop where
inj : Function.Injective f
#align uniform_embedding UniformEmbedding
#align uniform_embedding_iff uniformEmbedding_iff
theorem uniformEmbedding_iff' {f : α → β} :
UniformEmbedding f ↔ Injective f ∧ UniformContinuous f ∧ comap (Prod.map f f) (𝓤 β) ≤ 𝓤 α := by
rw [uniformEmbedding_iff, and_comm, uniformInducing_iff']
#align uniform_embedding_iff' uniformEmbedding_iff'
theorem Filter.HasBasis.uniformEmbedding_iff' {ι ι'} {p : ι → Prop} {p' : ι' → Prop} {s s'}
(h : (𝓤 α).HasBasis p s) (h' : (𝓤 β).HasBasis p' s') {f : α → β} :
UniformEmbedding f ↔ Injective f ∧
(∀ i, p' i → ∃ j, p j ∧ ∀ x y, (x, y) ∈ s j → (f x, f y) ∈ s' i) ∧
(∀ j, p j → ∃ i, p' i ∧ ∀ x y, (f x, f y) ∈ s' i → (x, y) ∈ s j) := by
rw [uniformEmbedding_iff, and_comm, h.uniformInducing_iff h']
#align filter.has_basis.uniform_embedding_iff' Filter.HasBasis.uniformEmbedding_iff'
theorem Filter.HasBasis.uniformEmbedding_iff {ι ι'} {p : ι → Prop} {p' : ι' → Prop} {s s'}
(h : (𝓤 α).HasBasis p s) (h' : (𝓤 β).HasBasis p' s') {f : α → β} :
UniformEmbedding f ↔ Injective f ∧ UniformContinuous f ∧
(∀ j, p j → ∃ i, p' i ∧ ∀ x y, (f x, f y) ∈ s' i → (x, y) ∈ s j) := by
simp only [h.uniformEmbedding_iff' h', h.uniformContinuous_iff h']
#align filter.has_basis.uniform_embedding_iff Filter.HasBasis.uniformEmbedding_iff
theorem uniformEmbedding_subtype_val {p : α → Prop} :
UniformEmbedding (Subtype.val : Subtype p → α) :=
{ comap_uniformity := rfl
inj := Subtype.val_injective }
#align uniform_embedding_subtype_val uniformEmbedding_subtype_val
#align uniform_embedding_subtype_coe uniformEmbedding_subtype_val
theorem uniformEmbedding_set_inclusion {s t : Set α} (hst : s ⊆ t) :
UniformEmbedding (inclusion hst) where
comap_uniformity := by rw [uniformity_subtype, uniformity_subtype, comap_comap]; rfl
inj := inclusion_injective hst
#align uniform_embedding_set_inclusion uniformEmbedding_set_inclusion
theorem UniformEmbedding.comp {g : β → γ} (hg : UniformEmbedding g) {f : α → β}
(hf : UniformEmbedding f) : UniformEmbedding (g ∘ f) :=
{ hg.toUniformInducing.comp hf.toUniformInducing with inj := hg.inj.comp hf.inj }
#align uniform_embedding.comp UniformEmbedding.comp
theorem UniformEmbedding.of_comp_iff {g : β → γ} (hg : UniformEmbedding g) {f : α → β} :
UniformEmbedding (g ∘ f) ↔ UniformEmbedding f := by
simp_rw [uniformEmbedding_iff, hg.toUniformInducing.of_comp_iff, hg.inj.of_comp_iff f]
theorem Equiv.uniformEmbedding {α β : Type*} [UniformSpace α] [UniformSpace β] (f : α ≃ β)
(h₁ : UniformContinuous f) (h₂ : UniformContinuous f.symm) : UniformEmbedding f :=
uniformEmbedding_iff'.2 ⟨f.injective, h₁, by rwa [← Equiv.prodCongr_apply, ← map_equiv_symm]⟩
#align equiv.uniform_embedding Equiv.uniformEmbedding
theorem uniformEmbedding_inl : UniformEmbedding (Sum.inl : α → α ⊕ β) :=
uniformEmbedding_iff'.2 ⟨Sum.inl_injective, uniformContinuous_inl, fun s hs =>
⟨Prod.map Sum.inl Sum.inl '' s ∪ range (Prod.map Sum.inr Sum.inr),
union_mem_sup (image_mem_map hs) range_mem_map, fun x h => by simpa using h⟩⟩
#align uniform_embedding_inl uniformEmbedding_inl
theorem uniformEmbedding_inr : UniformEmbedding (Sum.inr : β → α ⊕ β) :=
uniformEmbedding_iff'.2 ⟨Sum.inr_injective, uniformContinuous_inr, fun s hs =>
⟨range (Prod.map Sum.inl Sum.inl) ∪ Prod.map Sum.inr Sum.inr '' s,
union_mem_sup range_mem_map (image_mem_map hs), fun x h => by simpa using h⟩⟩
#align uniform_embedding_inr uniformEmbedding_inr
protected theorem UniformInducing.uniformEmbedding [T0Space α] {f : α → β}
(hf : UniformInducing f) : UniformEmbedding f :=
⟨hf, hf.inducing.injective⟩
#align uniform_inducing.uniform_embedding UniformInducing.uniformEmbedding
theorem uniformEmbedding_iff_uniformInducing [T0Space α] {f : α → β} :
UniformEmbedding f ↔ UniformInducing f :=
⟨UniformEmbedding.toUniformInducing, UniformInducing.uniformEmbedding⟩
#align uniform_embedding_iff_uniform_inducing uniformEmbedding_iff_uniformInducing
theorem comap_uniformity_of_spaced_out {α} {f : α → β} {s : Set (β × β)} (hs : s ∈ 𝓤 β)
(hf : Pairwise fun x y => (f x, f y) ∉ s) : comap (Prod.map f f) (𝓤 β) = 𝓟 idRel := by
refine le_antisymm ?_ (@refl_le_uniformity α (UniformSpace.comap f _))
calc
comap (Prod.map f f) (𝓤 β) ≤ comap (Prod.map f f) (𝓟 s) := comap_mono (le_principal_iff.2 hs)
_ = 𝓟 (Prod.map f f ⁻¹' s) := comap_principal
_ ≤ 𝓟 idRel := principal_mono.2 ?_
rintro ⟨x, y⟩; simpa [not_imp_not] using @hf x y
#align comap_uniformity_of_spaced_out comap_uniformity_of_spaced_out
| Mathlib/Topology/UniformSpace/UniformEmbedding.lean | 240 | 243 | theorem uniformEmbedding_of_spaced_out {α} {f : α → β} {s : Set (β × β)} (hs : s ∈ 𝓤 β)
(hf : Pairwise fun x y => (f x, f y) ∉ s) : @UniformEmbedding α β ⊥ ‹_› f := by |
let _ : UniformSpace α := ⊥; have := discreteTopology_bot α
exact UniformInducing.uniformEmbedding ⟨comap_uniformity_of_spaced_out hs hf⟩
|
import Mathlib.Analysis.InnerProductSpace.GramSchmidtOrtho
import Mathlib.LinearAlgebra.Orientation
#align_import analysis.inner_product_space.orientation from "leanprover-community/mathlib"@"bd65478311e4dfd41f48bf38c7e3b02fb75d0163"
noncomputable section
variable {E : Type*} [NormedAddCommGroup E] [InnerProductSpace ℝ E]
open FiniteDimensional
open scoped RealInnerProductSpace
namespace OrthonormalBasis
variable {ι : Type*} [Fintype ι] [DecidableEq ι] [ne : Nonempty ι] (e f : OrthonormalBasis ι ℝ E)
(x : Orientation ℝ E ι)
| Mathlib/Analysis/InnerProductSpace/Orientation.lean | 54 | 60 | theorem det_to_matrix_orthonormalBasis_of_same_orientation
(h : e.toBasis.orientation = f.toBasis.orientation) : e.toBasis.det f = 1 := by |
apply (e.det_to_matrix_orthonormalBasis_real f).resolve_right
have : 0 < e.toBasis.det f := by
rw [e.toBasis.orientation_eq_iff_det_pos] at h
simpa using h
linarith
|
import Mathlib.Algebra.MvPolynomial.Basic
#align_import data.mv_polynomial.rename from "leanprover-community/mathlib"@"2f5b500a507264de86d666a5f87ddb976e2d8de4"
noncomputable section
open Set Function Finsupp AddMonoidAlgebra
variable {σ τ α R S : Type*} [CommSemiring R] [CommSemiring S]
namespace MvPolynomial
section Rename
def rename (f : σ → τ) : MvPolynomial σ R →ₐ[R] MvPolynomial τ R :=
aeval (X ∘ f)
#align mv_polynomial.rename MvPolynomial.rename
theorem rename_C (f : σ → τ) (r : R) : rename f (C r) = C r :=
eval₂_C _ _ _
set_option linter.uppercaseLean3 false in
#align mv_polynomial.rename_C MvPolynomial.rename_C
@[simp]
theorem rename_X (f : σ → τ) (i : σ) : rename f (X i : MvPolynomial σ R) = X (f i) :=
eval₂_X _ _ _
set_option linter.uppercaseLean3 false in
#align mv_polynomial.rename_X MvPolynomial.rename_X
| Mathlib/Algebra/MvPolynomial/Rename.lean | 67 | 72 | theorem map_rename (f : R →+* S) (g : σ → τ) (p : MvPolynomial σ R) :
map f (rename g p) = rename g (map f p) := by |
apply MvPolynomial.induction_on p
(fun a => by simp only [map_C, rename_C])
(fun p q hp hq => by simp only [hp, hq, AlgHom.map_add, RingHom.map_add]) fun p n hp => by
simp only [hp, rename_X, map_X, RingHom.map_mul, AlgHom.map_mul]
|
import Mathlib.Analysis.InnerProductSpace.Spectrum
import Mathlib.Data.Matrix.Rank
import Mathlib.LinearAlgebra.Matrix.Diagonal
import Mathlib.LinearAlgebra.Matrix.Hermitian
#align_import linear_algebra.matrix.spectrum from "leanprover-community/mathlib"@"46b633fd842bef9469441c0209906f6dddd2b4f5"
namespace Matrix
variable {𝕜 : Type*} [RCLike 𝕜] {n : Type*} [Fintype n]
variable {A : Matrix n n 𝕜}
namespace IsHermitian
section DecidableEq
variable [DecidableEq n]
variable (hA : A.IsHermitian)
noncomputable def eigenvalues₀ : Fin (Fintype.card n) → ℝ :=
(isHermitian_iff_isSymmetric.1 hA).eigenvalues finrank_euclideanSpace
#align matrix.is_hermitian.eigenvalues₀ Matrix.IsHermitian.eigenvalues₀
noncomputable def eigenvalues : n → ℝ := fun i =>
hA.eigenvalues₀ <| (Fintype.equivOfCardEq (Fintype.card_fin _)).symm i
#align matrix.is_hermitian.eigenvalues Matrix.IsHermitian.eigenvalues
noncomputable def eigenvectorBasis : OrthonormalBasis n 𝕜 (EuclideanSpace 𝕜 n) :=
((isHermitian_iff_isSymmetric.1 hA).eigenvectorBasis finrank_euclideanSpace).reindex
(Fintype.equivOfCardEq (Fintype.card_fin _))
#align matrix.is_hermitian.eigenvector_basis Matrix.IsHermitian.eigenvectorBasis
lemma mulVec_eigenvectorBasis (j : n) :
A *ᵥ ⇑(hA.eigenvectorBasis j) = (hA.eigenvalues j) • ⇑(hA.eigenvectorBasis j) := by
simpa only [eigenvectorBasis, OrthonormalBasis.reindex_apply, toEuclideanLin_apply,
RCLike.real_smul_eq_coe_smul (K := 𝕜)] using
congr(⇑$((isHermitian_iff_isSymmetric.1 hA).apply_eigenvectorBasis
finrank_euclideanSpace ((Fintype.equivOfCardEq (Fintype.card_fin _)).symm j)))
noncomputable def eigenvectorUnitary {𝕜 : Type*} [RCLike 𝕜] {n : Type*}
[Fintype n]{A : Matrix n n 𝕜} [DecidableEq n] (hA : Matrix.IsHermitian A) :
Matrix.unitaryGroup n 𝕜 :=
⟨(EuclideanSpace.basisFun n 𝕜).toBasis.toMatrix (hA.eigenvectorBasis).toBasis,
(EuclideanSpace.basisFun n 𝕜).toMatrix_orthonormalBasis_mem_unitary (eigenvectorBasis hA)⟩
#align matrix.is_hermitian.eigenvector_matrix Matrix.IsHermitian.eigenvectorUnitary
lemma eigenvectorUnitary_coe {𝕜 : Type*} [RCLike 𝕜] {n : Type*} [Fintype n]
{A : Matrix n n 𝕜} [DecidableEq n] (hA : Matrix.IsHermitian A) :
eigenvectorUnitary hA =
(EuclideanSpace.basisFun n 𝕜).toBasis.toMatrix (hA.eigenvectorBasis).toBasis :=
rfl
@[simp]
theorem eigenvectorUnitary_apply (i j : n) :
eigenvectorUnitary hA i j = ⇑(hA.eigenvectorBasis j) i :=
rfl
#align matrix.is_hermitian.eigenvector_matrix_apply Matrix.IsHermitian.eigenvectorUnitary_apply
theorem eigenvectorUnitary_mulVec (j : n) :
eigenvectorUnitary hA *ᵥ Pi.single j 1 = ⇑(hA.eigenvectorBasis j) := by
simp only [mulVec_single, eigenvectorUnitary_apply, mul_one]
theorem star_eigenvectorUnitary_mulVec (j : n) :
(star (eigenvectorUnitary hA : Matrix n n 𝕜)) *ᵥ ⇑(hA.eigenvectorBasis j) = Pi.single j 1 := by
rw [← eigenvectorUnitary_mulVec, mulVec_mulVec, unitary.coe_star_mul_self, one_mulVec]
theorem star_mul_self_mul_eq_diagonal :
(star (eigenvectorUnitary hA : Matrix n n 𝕜)) * A * (eigenvectorUnitary hA : Matrix n n 𝕜)
= diagonal (RCLike.ofReal ∘ hA.eigenvalues) := by
apply Matrix.toEuclideanLin.injective
apply Basis.ext (EuclideanSpace.basisFun n 𝕜).toBasis
intro i
simp only [toEuclideanLin_apply, OrthonormalBasis.coe_toBasis, EuclideanSpace.basisFun_apply,
WithLp.equiv_single, ← mulVec_mulVec, eigenvectorUnitary_mulVec, ← mulVec_mulVec,
mulVec_eigenvectorBasis, Matrix.diagonal_mulVec_single, mulVec_smul,
star_eigenvectorUnitary_mulVec, RCLike.real_smul_eq_coe_smul (K := 𝕜), WithLp.equiv_symm_smul,
WithLp.equiv_symm_single, Function.comp_apply, mul_one, WithLp.equiv_symm_single]
apply PiLp.ext
intro j
simp only [PiLp.smul_apply, EuclideanSpace.single_apply, smul_eq_mul, mul_ite, mul_one, mul_zero]
theorem spectral_theorem :
A = (eigenvectorUnitary hA : Matrix n n 𝕜) * diagonal (RCLike.ofReal ∘ hA.eigenvalues)
* (star (eigenvectorUnitary hA : Matrix n n 𝕜)) := by
rw [← star_mul_self_mul_eq_diagonal, mul_assoc, mul_assoc,
(Matrix.mem_unitaryGroup_iff).mp (eigenvectorUnitary hA).2, mul_one,
← mul_assoc, (Matrix.mem_unitaryGroup_iff).mp (eigenvectorUnitary hA).2, one_mul]
#align matrix.is_hermitian.spectral_theorem' Matrix.IsHermitian.spectral_theorem
| Mathlib/LinearAlgebra/Matrix/Spectrum.lean | 114 | 119 | theorem eigenvalues_eq (i : n) :
(hA.eigenvalues i) = RCLike.re (Matrix.dotProduct (star ⇑(hA.eigenvectorBasis i))
(A *ᵥ ⇑(hA.eigenvectorBasis i))):= by |
simp only [mulVec_eigenvectorBasis, dotProduct_smul,← EuclideanSpace.inner_eq_star_dotProduct,
inner_self_eq_norm_sq_to_K, RCLike.smul_re, hA.eigenvectorBasis.orthonormal.1 i,
mul_one, algebraMap.coe_one, one_pow, RCLike.one_re]
|
import Mathlib.Init.Data.Nat.Notation
import Mathlib.Init.Order.Defs
set_option autoImplicit true
structure UFModel (n) where
parent : Fin n → Fin n
rank : Nat → Nat
rank_lt : ∀ i, (parent i).1 ≠ i → rank i < rank (parent i)
structure UFNode (α : Type*) where
parent : Nat
value : α
rank : Nat
inductive UFModel.Agrees (arr : Array α) (f : α → β) : ∀ {n}, (Fin n → β) → Prop
| mk : Agrees arr f fun i ↦ f (arr.get i)
namespace UFModel.Agrees
theorem mk' {arr : Array α} {f : α → β} {n} {g : Fin n → β} (e : n = arr.size)
(H : ∀ i h₁ h₂, f (arr.get ⟨i, h₁⟩) = g ⟨i, h₂⟩) : Agrees arr f g := by
cases e
have : (fun i ↦ f (arr.get i)) = g := by funext ⟨i, h⟩; apply H
cases this; constructor
| Mathlib/Data/UnionFind.lean | 79 | 80 | theorem size_eq {arr : Array α} {m : Fin n → β} (H : Agrees arr f m) : n = arr.size := by |
cases H; rfl
|
import Mathlib.CategoryTheory.Preadditive.ProjectiveResolution
import Mathlib.Algebra.Homology.HomotopyCategory
import Mathlib.Tactic.SuppressCompilation
suppress_compilation
noncomputable section
universe v u
namespace CategoryTheory
variable {C : Type u} [Category.{v} C]
open Category Limits Projective
set_option linter.uppercaseLean3 false -- `ProjectiveResolution`
namespace ProjectiveResolution
section
variable [HasZeroObject C] [HasZeroMorphisms C]
def liftFZero {Y Z : C} (f : Y ⟶ Z) (P : ProjectiveResolution Y) (Q : ProjectiveResolution Z) :
P.complex.X 0 ⟶ Q.complex.X 0 :=
Projective.factorThru (P.π.f 0 ≫ f) (Q.π.f 0)
#align category_theory.ProjectiveResolution.lift_f_zero CategoryTheory.ProjectiveResolution.liftFZero
end
section Abelian
variable [Abelian C]
lemma exact₀ {Z : C} (P : ProjectiveResolution Z) :
(ShortComplex.mk _ _ P.complex_d_comp_π_f_zero).Exact :=
ShortComplex.exact_of_g_is_cokernel _ P.isColimitCokernelCofork
def liftFOne {Y Z : C} (f : Y ⟶ Z) (P : ProjectiveResolution Y) (Q : ProjectiveResolution Z) :
P.complex.X 1 ⟶ Q.complex.X 1 :=
Q.exact₀.liftFromProjective (P.complex.d 1 0 ≫ liftFZero f P Q) (by simp [liftFZero])
#align category_theory.ProjectiveResolution.lift_f_one CategoryTheory.ProjectiveResolution.liftFOne
@[simp]
theorem liftFOne_zero_comm {Y Z : C} (f : Y ⟶ Z) (P : ProjectiveResolution Y)
(Q : ProjectiveResolution Z) :
liftFOne f P Q ≫ Q.complex.d 1 0 = P.complex.d 1 0 ≫ liftFZero f P Q := by
apply Q.exact₀.liftFromProjective_comp
#align category_theory.ProjectiveResolution.lift_f_one_zero_comm CategoryTheory.ProjectiveResolution.liftFOne_zero_comm
def liftFSucc {Y Z : C} (P : ProjectiveResolution Y) (Q : ProjectiveResolution Z) (n : ℕ)
(g : P.complex.X n ⟶ Q.complex.X n) (g' : P.complex.X (n + 1) ⟶ Q.complex.X (n + 1))
(w : g' ≫ Q.complex.d (n + 1) n = P.complex.d (n + 1) n ≫ g) :
Σ'g'' : P.complex.X (n + 2) ⟶ Q.complex.X (n + 2),
g'' ≫ Q.complex.d (n + 2) (n + 1) = P.complex.d (n + 2) (n + 1) ≫ g' :=
⟨(Q.exact_succ n).liftFromProjective
(P.complex.d (n + 2) (n + 1) ≫ g') (by simp [w]),
(Q.exact_succ n).liftFromProjective_comp _ _⟩
#align category_theory.ProjectiveResolution.lift_f_succ CategoryTheory.ProjectiveResolution.liftFSucc
def lift {Y Z : C} (f : Y ⟶ Z) (P : ProjectiveResolution Y) (Q : ProjectiveResolution Z) :
P.complex ⟶ Q.complex :=
ChainComplex.mkHom _ _ (liftFZero f _ _) (liftFOne f _ _) (liftFOne_zero_comm f P Q)
fun n ⟨g, g', w⟩ => ⟨(liftFSucc P Q n g g' w).1, (liftFSucc P Q n g g' w).2⟩
#align category_theory.ProjectiveResolution.lift CategoryTheory.ProjectiveResolution.lift
@[reassoc (attr := simp)]
theorem lift_commutes {Y Z : C} (f : Y ⟶ Z) (P : ProjectiveResolution Y)
(Q : ProjectiveResolution Z) : lift f P Q ≫ Q.π = P.π ≫ (ChainComplex.single₀ C).map f := by
ext
simp [lift, liftFZero, liftFOne]
#align category_theory.ProjectiveResolution.lift_commutes CategoryTheory.ProjectiveResolution.lift_commutes
@[reassoc (attr := simp)]
lemma lift_commutes_zero {Y Z : C} (f : Y ⟶ Z)
(P : ProjectiveResolution Y) (Q : ProjectiveResolution Z) :
(lift f P Q).f 0 ≫ Q.π.f 0 = P.π.f 0 ≫ f :=
(HomologicalComplex.congr_hom (lift_commutes f P Q) 0).trans (by simp)
def liftHomotopyZeroZero {Y Z : C} {P : ProjectiveResolution Y} {Q : ProjectiveResolution Z}
(f : P.complex ⟶ Q.complex) (comm : f ≫ Q.π = 0) : P.complex.X 0 ⟶ Q.complex.X 1 :=
Q.exact₀.liftFromProjective (f.f 0) (congr_fun (congr_arg HomologicalComplex.Hom.f comm) 0)
#align category_theory.ProjectiveResolution.lift_homotopy_zero_zero CategoryTheory.ProjectiveResolution.liftHomotopyZeroZero
@[reassoc (attr := simp)]
lemma liftHomotopyZeroZero_comp {Y Z : C} {P : ProjectiveResolution Y} {Q : ProjectiveResolution Z}
(f : P.complex ⟶ Q.complex) (comm : f ≫ Q.π = 0) :
liftHomotopyZeroZero f comm ≫ Q.complex.d 1 0 = f.f 0 :=
Q.exact₀.liftFromProjective_comp _ _
def liftHomotopyZeroOne {Y Z : C} {P : ProjectiveResolution Y} {Q : ProjectiveResolution Z}
(f : P.complex ⟶ Q.complex) (comm : f ≫ Q.π = 0) :
P.complex.X 1 ⟶ Q.complex.X 2 :=
(Q.exact_succ 0).liftFromProjective (f.f 1 - P.complex.d 1 0 ≫ liftHomotopyZeroZero f comm)
(by rw [Preadditive.sub_comp, assoc, HomologicalComplex.Hom.comm,
liftHomotopyZeroZero_comp, sub_self])
#align category_theory.ProjectiveResolution.lift_homotopy_zero_one CategoryTheory.ProjectiveResolution.liftHomotopyZeroOne
@[reassoc (attr := simp)]
lemma liftHomotopyZeroOne_comp {Y Z : C} {P : ProjectiveResolution Y} {Q : ProjectiveResolution Z}
(f : P.complex ⟶ Q.complex) (comm : f ≫ Q.π = 0) :
liftHomotopyZeroOne f comm ≫ Q.complex.d 2 1 =
f.f 1 - P.complex.d 1 0 ≫ liftHomotopyZeroZero f comm :=
(Q.exact_succ 0).liftFromProjective_comp _ _
def liftHomotopyZeroSucc {Y Z : C} {P : ProjectiveResolution Y} {Q : ProjectiveResolution Z}
(f : P.complex ⟶ Q.complex) (n : ℕ) (g : P.complex.X n ⟶ Q.complex.X (n + 1))
(g' : P.complex.X (n + 1) ⟶ Q.complex.X (n + 2))
(w : f.f (n + 1) = P.complex.d (n + 1) n ≫ g + g' ≫ Q.complex.d (n + 2) (n + 1)) :
P.complex.X (n + 2) ⟶ Q.complex.X (n + 3) :=
(Q.exact_succ (n + 1)).liftFromProjective (f.f (n + 2) - P.complex.d _ _ ≫ g') (by simp [w])
#align category_theory.ProjectiveResolution.lift_homotopy_zero_succ CategoryTheory.ProjectiveResolution.liftHomotopyZeroSucc
@[reassoc (attr := simp)]
lemma liftHomotopyZeroSucc_comp {Y Z : C} {P : ProjectiveResolution Y} {Q : ProjectiveResolution Z}
(f : P.complex ⟶ Q.complex) (n : ℕ) (g : P.complex.X n ⟶ Q.complex.X (n + 1))
(g' : P.complex.X (n + 1) ⟶ Q.complex.X (n + 2))
(w : f.f (n + 1) = P.complex.d (n + 1) n ≫ g + g' ≫ Q.complex.d (n + 2) (n + 1)) :
liftHomotopyZeroSucc f n g g' w ≫ Q.complex.d (n + 3) (n + 2) =
f.f (n + 2) - P.complex.d _ _ ≫ g' :=
(Q.exact_succ (n+1)).liftFromProjective_comp _ _
def liftHomotopyZero {Y Z : C} {P : ProjectiveResolution Y} {Q : ProjectiveResolution Z}
(f : P.complex ⟶ Q.complex) (comm : f ≫ Q.π = 0) : Homotopy f 0 :=
Homotopy.mkInductive _ (liftHomotopyZeroZero f comm) (by simp )
(liftHomotopyZeroOne f comm) (by simp) fun n ⟨g, g', w⟩ =>
⟨liftHomotopyZeroSucc f n g g' w, by simp⟩
#align category_theory.ProjectiveResolution.lift_homotopy_zero CategoryTheory.ProjectiveResolution.liftHomotopyZero
def liftHomotopy {Y Z : C} (f : Y ⟶ Z) {P : ProjectiveResolution Y} {Q : ProjectiveResolution Z}
(g h : P.complex ⟶ Q.complex) (g_comm : g ≫ Q.π = P.π ≫ (ChainComplex.single₀ C).map f)
(h_comm : h ≫ Q.π = P.π ≫ (ChainComplex.single₀ C).map f) : Homotopy g h :=
Homotopy.equivSubZero.invFun (liftHomotopyZero _ (by simp [g_comm, h_comm]))
#align category_theory.ProjectiveResolution.lift_homotopy CategoryTheory.ProjectiveResolution.liftHomotopy
def liftIdHomotopy (X : C) (P : ProjectiveResolution X) :
Homotopy (lift (𝟙 X) P P) (𝟙 P.complex) := by
apply liftHomotopy (𝟙 X) <;> simp
#align category_theory.ProjectiveResolution.lift_id_homotopy CategoryTheory.ProjectiveResolution.liftIdHomotopy
def liftCompHomotopy {X Y Z : C} (f : X ⟶ Y) (g : Y ⟶ Z) (P : ProjectiveResolution X)
(Q : ProjectiveResolution Y) (R : ProjectiveResolution Z) :
Homotopy (lift (f ≫ g) P R) (lift f P Q ≫ lift g Q R) := by
apply liftHomotopy (f ≫ g) <;> simp
#align category_theory.ProjectiveResolution.lift_comp_homotopy CategoryTheory.ProjectiveResolution.liftCompHomotopy
-- We don't care about the actual definitions of these homotopies.
def homotopyEquiv {X : C} (P Q : ProjectiveResolution X) :
HomotopyEquiv P.complex Q.complex where
hom := lift (𝟙 X) P Q
inv := lift (𝟙 X) Q P
homotopyHomInvId := (liftCompHomotopy (𝟙 X) (𝟙 X) P Q P).symm.trans <| by
simpa [id_comp] using liftIdHomotopy _ _
homotopyInvHomId := (liftCompHomotopy (𝟙 X) (𝟙 X) Q P Q).symm.trans <| by
simpa [id_comp] using liftIdHomotopy _ _
#align category_theory.ProjectiveResolution.homotopy_equiv CategoryTheory.ProjectiveResolution.homotopyEquiv
@[reassoc (attr := simp)]
theorem homotopyEquiv_hom_π {X : C} (P Q : ProjectiveResolution X) :
(homotopyEquiv P Q).hom ≫ Q.π = P.π := by simp [homotopyEquiv]
#align category_theory.ProjectiveResolution.homotopy_equiv_hom_π CategoryTheory.ProjectiveResolution.homotopyEquiv_hom_π
@[reassoc (attr := simp)]
| Mathlib/CategoryTheory/Abelian/ProjectiveResolution.lean | 203 | 204 | theorem homotopyEquiv_inv_π {X : C} (P Q : ProjectiveResolution X) :
(homotopyEquiv P Q).inv ≫ P.π = Q.π := by | simp [homotopyEquiv]
|
import Mathlib.Analysis.NormedSpace.AddTorsorBases
#align_import analysis.convex.intrinsic from "leanprover-community/mathlib"@"f0c8bf9245297a541f468be517f1bde6195105e9"
open AffineSubspace Set
open scoped Pointwise
variable {𝕜 V W Q P : Type*}
section AddTorsor
variable (𝕜) [Ring 𝕜] [AddCommGroup V] [Module 𝕜 V] [TopologicalSpace P] [AddTorsor V P]
{s t : Set P} {x : P}
def intrinsicInterior (s : Set P) : Set P :=
(↑) '' interior ((↑) ⁻¹' s : Set <| affineSpan 𝕜 s)
#align intrinsic_interior intrinsicInterior
def intrinsicFrontier (s : Set P) : Set P :=
(↑) '' frontier ((↑) ⁻¹' s : Set <| affineSpan 𝕜 s)
#align intrinsic_frontier intrinsicFrontier
def intrinsicClosure (s : Set P) : Set P :=
(↑) '' closure ((↑) ⁻¹' s : Set <| affineSpan 𝕜 s)
#align intrinsic_closure intrinsicClosure
variable {𝕜}
@[simp]
theorem mem_intrinsicInterior :
x ∈ intrinsicInterior 𝕜 s ↔ ∃ y, y ∈ interior ((↑) ⁻¹' s : Set <| affineSpan 𝕜 s) ∧ ↑y = x :=
mem_image _ _ _
#align mem_intrinsic_interior mem_intrinsicInterior
@[simp]
theorem mem_intrinsicFrontier :
x ∈ intrinsicFrontier 𝕜 s ↔ ∃ y, y ∈ frontier ((↑) ⁻¹' s : Set <| affineSpan 𝕜 s) ∧ ↑y = x :=
mem_image _ _ _
#align mem_intrinsic_frontier mem_intrinsicFrontier
@[simp]
theorem mem_intrinsicClosure :
x ∈ intrinsicClosure 𝕜 s ↔ ∃ y, y ∈ closure ((↑) ⁻¹' s : Set <| affineSpan 𝕜 s) ∧ ↑y = x :=
mem_image _ _ _
#align mem_intrinsic_closure mem_intrinsicClosure
theorem intrinsicInterior_subset : intrinsicInterior 𝕜 s ⊆ s :=
image_subset_iff.2 interior_subset
#align intrinsic_interior_subset intrinsicInterior_subset
theorem intrinsicFrontier_subset (hs : IsClosed s) : intrinsicFrontier 𝕜 s ⊆ s :=
image_subset_iff.2 (hs.preimage continuous_induced_dom).frontier_subset
#align intrinsic_frontier_subset intrinsicFrontier_subset
theorem intrinsicFrontier_subset_intrinsicClosure : intrinsicFrontier 𝕜 s ⊆ intrinsicClosure 𝕜 s :=
image_subset _ frontier_subset_closure
#align intrinsic_frontier_subset_intrinsic_closure intrinsicFrontier_subset_intrinsicClosure
theorem subset_intrinsicClosure : s ⊆ intrinsicClosure 𝕜 s :=
fun x hx => ⟨⟨x, subset_affineSpan _ _ hx⟩, subset_closure hx, rfl⟩
#align subset_intrinsic_closure subset_intrinsicClosure
@[simp]
theorem intrinsicInterior_empty : intrinsicInterior 𝕜 (∅ : Set P) = ∅ := by simp [intrinsicInterior]
#align intrinsic_interior_empty intrinsicInterior_empty
@[simp]
theorem intrinsicFrontier_empty : intrinsicFrontier 𝕜 (∅ : Set P) = ∅ := by simp [intrinsicFrontier]
#align intrinsic_frontier_empty intrinsicFrontier_empty
@[simp]
theorem intrinsicClosure_empty : intrinsicClosure 𝕜 (∅ : Set P) = ∅ := by simp [intrinsicClosure]
#align intrinsic_closure_empty intrinsicClosure_empty
@[simp]
theorem intrinsicClosure_nonempty : (intrinsicClosure 𝕜 s).Nonempty ↔ s.Nonempty :=
⟨by simp_rw [nonempty_iff_ne_empty]; rintro h rfl; exact h intrinsicClosure_empty,
Nonempty.mono subset_intrinsicClosure⟩
#align intrinsic_closure_nonempty intrinsicClosure_nonempty
alias ⟨Set.Nonempty.ofIntrinsicClosure, Set.Nonempty.intrinsicClosure⟩ := intrinsicClosure_nonempty
#align set.nonempty.of_intrinsic_closure Set.Nonempty.ofIntrinsicClosure
#align set.nonempty.intrinsic_closure Set.Nonempty.intrinsicClosure
--attribute [protected] Set.Nonempty.intrinsicClosure -- Porting note: removed
@[simp]
theorem intrinsicInterior_singleton (x : P) : intrinsicInterior 𝕜 ({x} : Set P) = {x} := by
simpa only [intrinsicInterior, preimage_coe_affineSpan_singleton, interior_univ, image_univ,
Subtype.range_coe] using coe_affineSpan_singleton _ _ _
#align intrinsic_interior_singleton intrinsicInterior_singleton
@[simp]
theorem intrinsicFrontier_singleton (x : P) : intrinsicFrontier 𝕜 ({x} : Set P) = ∅ := by
rw [intrinsicFrontier, preimage_coe_affineSpan_singleton, frontier_univ, image_empty]
#align intrinsic_frontier_singleton intrinsicFrontier_singleton
@[simp]
theorem intrinsicClosure_singleton (x : P) : intrinsicClosure 𝕜 ({x} : Set P) = {x} := by
simpa only [intrinsicClosure, preimage_coe_affineSpan_singleton, closure_univ, image_univ,
Subtype.range_coe] using coe_affineSpan_singleton _ _ _
#align intrinsic_closure_singleton intrinsicClosure_singleton
theorem intrinsicClosure_mono (h : s ⊆ t) : intrinsicClosure 𝕜 s ⊆ intrinsicClosure 𝕜 t := by
refine image_subset_iff.2 fun x hx => ?_
refine ⟨Set.inclusion (affineSpan_mono _ h) x, ?_, rfl⟩
refine (continuous_inclusion (affineSpan_mono _ h)).closure_preimage_subset _ (closure_mono ?_ hx)
exact fun y hy => h hy
#align intrinsic_closure_mono intrinsicClosure_mono
theorem interior_subset_intrinsicInterior : interior s ⊆ intrinsicInterior 𝕜 s :=
fun x hx => ⟨⟨x, subset_affineSpan _ _ <| interior_subset hx⟩,
preimage_interior_subset_interior_preimage continuous_subtype_val hx, rfl⟩
#align interior_subset_intrinsic_interior interior_subset_intrinsicInterior
theorem intrinsicClosure_subset_closure : intrinsicClosure 𝕜 s ⊆ closure s :=
image_subset_iff.2 <| continuous_subtype_val.closure_preimage_subset _
#align intrinsic_closure_subset_closure intrinsicClosure_subset_closure
theorem intrinsicFrontier_subset_frontier : intrinsicFrontier 𝕜 s ⊆ frontier s :=
image_subset_iff.2 <| continuous_subtype_val.frontier_preimage_subset _
#align intrinsic_frontier_subset_frontier intrinsicFrontier_subset_frontier
theorem intrinsicClosure_subset_affineSpan : intrinsicClosure 𝕜 s ⊆ affineSpan 𝕜 s :=
(image_subset_range _ _).trans Subtype.range_coe.subset
#align intrinsic_closure_subset_affine_span intrinsicClosure_subset_affineSpan
@[simp]
theorem intrinsicClosure_diff_intrinsicFrontier (s : Set P) :
intrinsicClosure 𝕜 s \ intrinsicFrontier 𝕜 s = intrinsicInterior 𝕜 s :=
(image_diff Subtype.coe_injective _ _).symm.trans <| by
rw [closure_diff_frontier, intrinsicInterior]
#align intrinsic_closure_diff_intrinsic_frontier intrinsicClosure_diff_intrinsicFrontier
@[simp]
theorem intrinsicClosure_diff_intrinsicInterior (s : Set P) :
intrinsicClosure 𝕜 s \ intrinsicInterior 𝕜 s = intrinsicFrontier 𝕜 s :=
(image_diff Subtype.coe_injective _ _).symm
#align intrinsic_closure_diff_intrinsic_interior intrinsicClosure_diff_intrinsicInterior
@[simp]
theorem intrinsicInterior_union_intrinsicFrontier (s : Set P) :
intrinsicInterior 𝕜 s ∪ intrinsicFrontier 𝕜 s = intrinsicClosure 𝕜 s := by
simp [intrinsicClosure, intrinsicInterior, intrinsicFrontier, closure_eq_interior_union_frontier,
image_union]
#align intrinsic_interior_union_intrinsic_frontier intrinsicInterior_union_intrinsicFrontier
@[simp]
| Mathlib/Analysis/Convex/Intrinsic.lean | 202 | 204 | theorem intrinsicFrontier_union_intrinsicInterior (s : Set P) :
intrinsicFrontier 𝕜 s ∪ intrinsicInterior 𝕜 s = intrinsicClosure 𝕜 s := by |
rw [union_comm, intrinsicInterior_union_intrinsicFrontier]
|
import Mathlib.Combinatorics.Quiver.Path
import Mathlib.Combinatorics.Quiver.Push
#align_import combinatorics.quiver.symmetric from "leanprover-community/mathlib"@"706d88f2b8fdfeb0b22796433d7a6c1a010af9f2"
universe v u w v'
namespace Quiver
-- Porting note: no hasNonemptyInstance linter yet
def Symmetrify (V : Type*) := V
#align quiver.symmetrify Quiver.Symmetrify
instance symmetrifyQuiver (V : Type u) [Quiver V] : Quiver (Symmetrify V) :=
⟨fun a b : V ↦ Sum (a ⟶ b) (b ⟶ a)⟩
variable (U V W : Type*) [Quiver.{u + 1} U] [Quiver.{v + 1} V] [Quiver.{w + 1} W]
class HasReverse where
reverse' : ∀ {a b : V}, (a ⟶ b) → (b ⟶ a)
#align quiver.has_reverse Quiver.HasReverse
def reverse {V} [Quiver.{v + 1} V] [HasReverse V] {a b : V} : (a ⟶ b) → (b ⟶ a) :=
HasReverse.reverse'
#align quiver.reverse Quiver.reverse
class HasInvolutiveReverse extends HasReverse V where
inv' : ∀ {a b : V} (f : a ⟶ b), reverse (reverse f) = f
#align quiver.has_involutive_reverse Quiver.HasInvolutiveReverse
variable {U V W}
@[simp]
theorem reverse_reverse [h : HasInvolutiveReverse V] {a b : V} (f : a ⟶ b) :
reverse (reverse f) = f := by apply h.inv'
#align quiver.reverse_reverse Quiver.reverse_reverse
@[simp]
theorem reverse_inj [h : HasInvolutiveReverse V] {a b : V}
(f g : a ⟶ b) : reverse f = reverse g ↔ f = g := by
constructor
· rintro h
simpa using congr_arg Quiver.reverse h
· rintro h
congr
#align quiver.reverse_inj Quiver.reverse_inj
theorem eq_reverse_iff [h : HasInvolutiveReverse V] {a b : V} (f : a ⟶ b)
(g : b ⟶ a) : f = reverse g ↔ reverse f = g := by
rw [← reverse_inj, reverse_reverse]
#align quiver.eq_reverse_iff Quiver.eq_reverse_iff
instance : HasReverse (Symmetrify V) :=
⟨fun e => e.swap⟩
instance :
HasInvolutiveReverse
(Symmetrify V) where
toHasReverse := ⟨fun e ↦ e.swap⟩
inv' e := congr_fun Sum.swap_swap_eq e
@[simp]
theorem symmetrify_reverse {a b : Symmetrify V} (e : a ⟶ b) : reverse e = e.swap :=
rfl
#align quiver.symmetrify_reverse Quiver.symmetrify_reverse
namespace Symmetrify
def of : Prefunctor V (Symmetrify V) where
obj := id
map := Sum.inl
#align quiver.symmetrify.of Quiver.Symmetrify.of
variable {V' : Type*} [Quiver.{v' + 1} V']
def lift [HasReverse V'] (φ : Prefunctor V V') :
Prefunctor (Symmetrify V) V' where
obj := φ.obj
map f := match f with
| Sum.inl g => φ.map g
| Sum.inr g => reverse (φ.map g)
#align quiver.symmetrify.lift Quiver.Symmetrify.lift
theorem lift_spec [HasReverse V'] (φ : Prefunctor V V') :
Symmetrify.of.comp (Symmetrify.lift φ) = φ := by
fapply Prefunctor.ext
· rintro X
rfl
· rintro X Y f
rfl
#align quiver.symmetrify.lift_spec Quiver.Symmetrify.lift_spec
theorem lift_reverse [h : HasInvolutiveReverse V']
(φ : Prefunctor V V') {X Y : Symmetrify V} (f : X ⟶ Y) :
(Symmetrify.lift φ).map (Quiver.reverse f) = Quiver.reverse ((Symmetrify.lift φ).map f) := by
dsimp [Symmetrify.lift]; cases f
· simp only
rfl
· simp only [reverse_reverse]
rfl
#align quiver.symmetrify.lift_reverse Quiver.Symmetrify.lift_reverse
| Mathlib/Combinatorics/Quiver/Symmetric.lean | 208 | 219 | theorem lift_unique [HasReverse V'] (φ : V ⥤q V') (Φ : Symmetrify V ⥤q V') (hΦ : (of ⋙q Φ) = φ)
(hΦinv : ∀ {X Y : Symmetrify V} (f : X ⟶ Y),
Φ.map (Quiver.reverse f) = Quiver.reverse (Φ.map f)) :
Φ = Symmetrify.lift φ := by |
subst_vars
fapply Prefunctor.ext
· rintro X
rfl
· rintro X Y f
cases f
· rfl
· exact hΦinv (Sum.inl _)
|
import Mathlib.Topology.UniformSpace.CompleteSeparated
import Mathlib.Topology.EMetricSpace.Lipschitz
import Mathlib.Topology.MetricSpace.Basic
import Mathlib.Topology.MetricSpace.Bounded
#align_import topology.metric_space.antilipschitz from "leanprover-community/mathlib"@"c8f305514e0d47dfaa710f5a52f0d21b588e6328"
variable {α β γ : Type*}
open scoped NNReal ENNReal Uniformity Topology
open Set Filter Bornology
def AntilipschitzWith [PseudoEMetricSpace α] [PseudoEMetricSpace β] (K : ℝ≥0) (f : α → β) :=
∀ x y, edist x y ≤ K * edist (f x) (f y)
#align antilipschitz_with AntilipschitzWith
theorem AntilipschitzWith.edist_lt_top [PseudoEMetricSpace α] [PseudoMetricSpace β] {K : ℝ≥0}
{f : α → β} (h : AntilipschitzWith K f) (x y : α) : edist x y < ⊤ :=
(h x y).trans_lt <| ENNReal.mul_lt_top ENNReal.coe_ne_top (edist_ne_top _ _)
#align antilipschitz_with.edist_lt_top AntilipschitzWith.edist_lt_top
theorem AntilipschitzWith.edist_ne_top [PseudoEMetricSpace α] [PseudoMetricSpace β] {K : ℝ≥0}
{f : α → β} (h : AntilipschitzWith K f) (x y : α) : edist x y ≠ ⊤ :=
(h.edist_lt_top x y).ne
#align antilipschitz_with.edist_ne_top AntilipschitzWith.edist_ne_top
section Metric
variable [PseudoMetricSpace α] [PseudoMetricSpace β] {K : ℝ≥0} {f : α → β}
| Mathlib/Topology/MetricSpace/Antilipschitz.lean | 53 | 56 | theorem antilipschitzWith_iff_le_mul_nndist :
AntilipschitzWith K f ↔ ∀ x y, nndist x y ≤ K * nndist (f x) (f y) := by |
simp only [AntilipschitzWith, edist_nndist]
norm_cast
|
import Mathlib.Data.Matrix.Invertible
import Mathlib.LinearAlgebra.Matrix.NonsingularInverse
import Mathlib.LinearAlgebra.Matrix.PosDef
#align_import linear_algebra.matrix.schur_complement from "leanprover-community/mathlib"@"a176cb1219e300e85793d44583dede42377b51af"
variable {l m n α : Type*}
namespace Matrix
open scoped Matrix
section CommRing
variable [Fintype l] [Fintype m] [Fintype n]
variable [DecidableEq l] [DecidableEq m] [DecidableEq n]
variable [CommRing α]
theorem fromBlocks_eq_of_invertible₁₁ (A : Matrix m m α) (B : Matrix m n α) (C : Matrix l m α)
(D : Matrix l n α) [Invertible A] :
fromBlocks A B C D =
fromBlocks 1 0 (C * ⅟ A) 1 * fromBlocks A 0 0 (D - C * ⅟ A * B) *
fromBlocks 1 (⅟ A * B) 0 1 := by
simp only [fromBlocks_multiply, Matrix.mul_zero, Matrix.zero_mul, add_zero, zero_add,
Matrix.one_mul, Matrix.mul_one, invOf_mul_self, Matrix.mul_invOf_self_assoc,
Matrix.mul_invOf_mul_self_cancel, Matrix.mul_assoc, add_sub_cancel]
#align matrix.from_blocks_eq_of_invertible₁₁ Matrix.fromBlocks_eq_of_invertible₁₁
theorem fromBlocks_eq_of_invertible₂₂ (A : Matrix l m α) (B : Matrix l n α) (C : Matrix n m α)
(D : Matrix n n α) [Invertible D] :
fromBlocks A B C D =
fromBlocks 1 (B * ⅟ D) 0 1 * fromBlocks (A - B * ⅟ D * C) 0 0 D *
fromBlocks 1 0 (⅟ D * C) 1 :=
(Matrix.reindex (Equiv.sumComm _ _) (Equiv.sumComm _ _)).injective <| by
simpa [reindex_apply, Equiv.sumComm_symm, ← submatrix_mul_equiv _ _ _ (Equiv.sumComm n m), ←
submatrix_mul_equiv _ _ _ (Equiv.sumComm n l), Equiv.sumComm_apply,
fromBlocks_submatrix_sum_swap_sum_swap] using fromBlocks_eq_of_invertible₁₁ D C B A
#align matrix.from_blocks_eq_of_invertible₂₂ Matrix.fromBlocks_eq_of_invertible₂₂
section Det
theorem det_fromBlocks₁₁ (A : Matrix m m α) (B : Matrix m n α) (C : Matrix n m α)
(D : Matrix n n α) [Invertible A] :
(Matrix.fromBlocks A B C D).det = det A * det (D - C * ⅟ A * B) := by
rw [fromBlocks_eq_of_invertible₁₁ (A := A), det_mul, det_mul, det_fromBlocks_zero₂₁,
det_fromBlocks_zero₂₁, det_fromBlocks_zero₁₂, det_one, det_one, one_mul, one_mul, mul_one]
#align matrix.det_from_blocks₁₁ Matrix.det_fromBlocks₁₁
@[simp]
theorem det_fromBlocks_one₁₁ (B : Matrix m n α) (C : Matrix n m α) (D : Matrix n n α) :
(Matrix.fromBlocks 1 B C D).det = det (D - C * B) := by
haveI : Invertible (1 : Matrix m m α) := invertibleOne
rw [det_fromBlocks₁₁, invOf_one, Matrix.mul_one, det_one, one_mul]
#align matrix.det_from_blocks_one₁₁ Matrix.det_fromBlocks_one₁₁
theorem det_fromBlocks₂₂ (A : Matrix m m α) (B : Matrix m n α) (C : Matrix n m α)
(D : Matrix n n α) [Invertible D] :
(Matrix.fromBlocks A B C D).det = det D * det (A - B * ⅟ D * C) := by
have : fromBlocks A B C D =
(fromBlocks D C B A).submatrix (Equiv.sumComm _ _) (Equiv.sumComm _ _) := by
ext (i j)
cases i <;> cases j <;> rfl
rw [this, det_submatrix_equiv_self, det_fromBlocks₁₁]
#align matrix.det_from_blocks₂₂ Matrix.det_fromBlocks₂₂
@[simp]
theorem det_fromBlocks_one₂₂ (A : Matrix m m α) (B : Matrix m n α) (C : Matrix n m α) :
(Matrix.fromBlocks A B C 1).det = det (A - B * C) := by
haveI : Invertible (1 : Matrix n n α) := invertibleOne
rw [det_fromBlocks₂₂, invOf_one, Matrix.mul_one, det_one, one_mul]
#align matrix.det_from_blocks_one₂₂ Matrix.det_fromBlocks_one₂₂
theorem det_one_add_mul_comm (A : Matrix m n α) (B : Matrix n m α) :
det (1 + A * B) = det (1 + B * A) :=
calc
det (1 + A * B) = det (fromBlocks 1 (-A) B 1) := by
rw [det_fromBlocks_one₂₂, Matrix.neg_mul, sub_neg_eq_add]
_ = det (1 + B * A) := by rw [det_fromBlocks_one₁₁, Matrix.mul_neg, sub_neg_eq_add]
#align matrix.det_one_add_mul_comm Matrix.det_one_add_mul_comm
| Mathlib/LinearAlgebra/Matrix/SchurComplement.lean | 434 | 435 | theorem det_mul_add_one_comm (A : Matrix m n α) (B : Matrix n m α) :
det (A * B + 1) = det (B * A + 1) := by | rw [add_comm, det_one_add_mul_comm, add_comm]
|
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
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]
#align set.image_comm Set.image_comm
theorem _root_.Function.Semiconj.set_image {f : α → β} {ga : α → α} {gb : β → β}
(h : Function.Semiconj f ga gb) : Function.Semiconj (image f) (image ga) (image gb) := fun _ =>
image_comm h
#align function.semiconj.set_image Function.Semiconj.set_image
theorem _root_.Function.Commute.set_image {f g : α → α} (h : Function.Commute f g) :
Function.Commute (image f) (image g) :=
Function.Semiconj.set_image h
#align function.commute.set_image Function.Commute.set_image
@[gcongr]
theorem image_subset {a b : Set α} (f : α → β) (h : a ⊆ b) : f '' a ⊆ f '' b := by
simp only [subset_def, mem_image]
exact fun x => fun ⟨w, h1, h2⟩ => ⟨w, h h1, h2⟩
#align set.image_subset Set.image_subset
lemma monotone_image {f : α → β} : Monotone (image f) := fun _ _ => image_subset _
#align set.monotone_image Set.monotone_image
theorem image_union (f : α → β) (s t : Set α) : f '' (s ∪ t) = f '' s ∪ f '' t :=
ext fun x =>
⟨by rintro ⟨a, h | h, rfl⟩ <;> [left; right] <;> exact ⟨_, h, rfl⟩, by
rintro (⟨a, h, rfl⟩ | ⟨a, h, rfl⟩) <;> refine ⟨_, ?_, rfl⟩
· exact mem_union_left t h
· exact mem_union_right s h⟩
#align set.image_union Set.image_union
@[simp]
theorem image_empty (f : α → β) : f '' ∅ = ∅ := by
ext
simp
#align set.image_empty Set.image_empty
theorem image_inter_subset (f : α → β) (s t : Set α) : f '' (s ∩ t) ⊆ f '' s ∩ f '' t :=
subset_inter (image_subset _ inter_subset_left) (image_subset _ inter_subset_right)
#align set.image_inter_subset Set.image_inter_subset
theorem image_inter_on {f : α → β} {s t : Set α} (h : ∀ x ∈ t, ∀ y ∈ s, f x = f y → x = y) :
f '' (s ∩ t) = f '' s ∩ f '' t :=
(image_inter_subset _ _ _).antisymm
fun b ⟨⟨a₁, ha₁, h₁⟩, ⟨a₂, ha₂, h₂⟩⟩ ↦
have : a₂ = a₁ := h _ ha₂ _ ha₁ (by simp [*])
⟨a₁, ⟨ha₁, this ▸ ha₂⟩, h₁⟩
#align set.image_inter_on Set.image_inter_on
theorem image_inter {f : α → β} {s t : Set α} (H : Injective f) : f '' (s ∩ t) = f '' s ∩ f '' t :=
image_inter_on fun _ _ _ _ h => H h
#align set.image_inter Set.image_inter
theorem image_univ_of_surjective {ι : Type*} {f : ι → β} (H : Surjective f) : f '' univ = univ :=
eq_univ_of_forall <| by simpa [image]
#align set.image_univ_of_surjective Set.image_univ_of_surjective
@[simp]
theorem image_singleton {f : α → β} {a : α} : f '' {a} = {f a} := by
ext
simp [image, eq_comm]
#align set.image_singleton Set.image_singleton
@[simp]
theorem Nonempty.image_const {s : Set α} (hs : s.Nonempty) (a : β) : (fun _ => a) '' s = {a} :=
ext fun _ =>
⟨fun ⟨_, _, h⟩ => h ▸ mem_singleton _, fun h =>
(eq_of_mem_singleton h).symm ▸ hs.imp fun _ hy => ⟨hy, rfl⟩⟩
#align set.nonempty.image_const Set.Nonempty.image_const
@[simp, mfld_simps]
theorem image_eq_empty {α β} {f : α → β} {s : Set α} : f '' s = ∅ ↔ s = ∅ := by
simp only [eq_empty_iff_forall_not_mem]
exact ⟨fun H a ha => H _ ⟨_, ha, rfl⟩, fun H b ⟨_, ha, _⟩ => H _ ha⟩
#align set.image_eq_empty Set.image_eq_empty
-- Porting note: `compl` is already defined in `Init.Set`
theorem preimage_compl_eq_image_compl [BooleanAlgebra α] (S : Set α) :
HasCompl.compl ⁻¹' S = HasCompl.compl '' S :=
Set.ext fun x =>
⟨fun h => ⟨xᶜ, h, compl_compl x⟩, fun h =>
Exists.elim h fun _ hy => (compl_eq_comm.mp hy.2).symm.subst hy.1⟩
#align set.preimage_compl_eq_image_compl Set.preimage_compl_eq_image_compl
theorem mem_compl_image [BooleanAlgebra α] (t : α) (S : Set α) :
t ∈ HasCompl.compl '' S ↔ tᶜ ∈ S := by
simp [← preimage_compl_eq_image_compl]
#align set.mem_compl_image Set.mem_compl_image
@[simp]
| Mathlib/Data/Set/Image.lean | 367 | 367 | theorem image_id_eq : image (id : α → α) = id := by | ext; simp
|
import Mathlib.Topology.Constructions
#align_import topology.continuous_on from "leanprover-community/mathlib"@"d4f691b9e5f94cfc64639973f3544c95f8d5d494"
open Set Filter Function Topology Filter
variable {α : Type*} {β : Type*} {γ : Type*} {δ : Type*}
variable [TopologicalSpace α]
@[simp]
theorem nhds_bind_nhdsWithin {a : α} {s : Set α} : ((𝓝 a).bind fun x => 𝓝[s] x) = 𝓝[s] a :=
bind_inf_principal.trans <| congr_arg₂ _ nhds_bind_nhds rfl
#align nhds_bind_nhds_within nhds_bind_nhdsWithin
@[simp]
theorem eventually_nhds_nhdsWithin {a : α} {s : Set α} {p : α → Prop} :
(∀ᶠ y in 𝓝 a, ∀ᶠ x in 𝓝[s] y, p x) ↔ ∀ᶠ x in 𝓝[s] a, p x :=
Filter.ext_iff.1 nhds_bind_nhdsWithin { x | p x }
#align eventually_nhds_nhds_within eventually_nhds_nhdsWithin
theorem eventually_nhdsWithin_iff {a : α} {s : Set α} {p : α → Prop} :
(∀ᶠ x in 𝓝[s] a, p x) ↔ ∀ᶠ x in 𝓝 a, x ∈ s → p x :=
eventually_inf_principal
#align eventually_nhds_within_iff eventually_nhdsWithin_iff
theorem frequently_nhdsWithin_iff {z : α} {s : Set α} {p : α → Prop} :
(∃ᶠ x in 𝓝[s] z, p x) ↔ ∃ᶠ x in 𝓝 z, p x ∧ x ∈ s :=
frequently_inf_principal.trans <| by simp only [and_comm]
#align frequently_nhds_within_iff frequently_nhdsWithin_iff
theorem mem_closure_ne_iff_frequently_within {z : α} {s : Set α} :
z ∈ closure (s \ {z}) ↔ ∃ᶠ x in 𝓝[≠] z, x ∈ s := by
simp [mem_closure_iff_frequently, frequently_nhdsWithin_iff]
#align mem_closure_ne_iff_frequently_within mem_closure_ne_iff_frequently_within
@[simp]
theorem eventually_nhdsWithin_nhdsWithin {a : α} {s : Set α} {p : α → Prop} :
(∀ᶠ y in 𝓝[s] a, ∀ᶠ x in 𝓝[s] y, p x) ↔ ∀ᶠ x in 𝓝[s] a, p x := by
refine ⟨fun h => ?_, fun h => (eventually_nhds_nhdsWithin.2 h).filter_mono inf_le_left⟩
simp only [eventually_nhdsWithin_iff] at h ⊢
exact h.mono fun x hx hxs => (hx hxs).self_of_nhds hxs
#align eventually_nhds_within_nhds_within eventually_nhdsWithin_nhdsWithin
theorem nhdsWithin_eq (a : α) (s : Set α) :
𝓝[s] a = ⨅ t ∈ { t : Set α | a ∈ t ∧ IsOpen t }, 𝓟 (t ∩ s) :=
((nhds_basis_opens a).inf_principal s).eq_biInf
#align nhds_within_eq nhdsWithin_eq
theorem nhdsWithin_univ (a : α) : 𝓝[Set.univ] a = 𝓝 a := by
rw [nhdsWithin, principal_univ, inf_top_eq]
#align nhds_within_univ nhdsWithin_univ
theorem nhdsWithin_hasBasis {p : β → Prop} {s : β → Set α} {a : α} (h : (𝓝 a).HasBasis p s)
(t : Set α) : (𝓝[t] a).HasBasis p fun i => s i ∩ t :=
h.inf_principal t
#align nhds_within_has_basis nhdsWithin_hasBasis
theorem nhdsWithin_basis_open (a : α) (t : Set α) :
(𝓝[t] a).HasBasis (fun u => a ∈ u ∧ IsOpen u) fun u => u ∩ t :=
nhdsWithin_hasBasis (nhds_basis_opens a) t
#align nhds_within_basis_open nhdsWithin_basis_open
theorem mem_nhdsWithin {t : Set α} {a : α} {s : Set α} :
t ∈ 𝓝[s] a ↔ ∃ u, IsOpen u ∧ a ∈ u ∧ u ∩ s ⊆ t := by
simpa only [and_assoc, and_left_comm] using (nhdsWithin_basis_open a s).mem_iff
#align mem_nhds_within mem_nhdsWithin
theorem mem_nhdsWithin_iff_exists_mem_nhds_inter {t : Set α} {a : α} {s : Set α} :
t ∈ 𝓝[s] a ↔ ∃ u ∈ 𝓝 a, u ∩ s ⊆ t :=
(nhdsWithin_hasBasis (𝓝 a).basis_sets s).mem_iff
#align mem_nhds_within_iff_exists_mem_nhds_inter mem_nhdsWithin_iff_exists_mem_nhds_inter
theorem diff_mem_nhdsWithin_compl {x : α} {s : Set α} (hs : s ∈ 𝓝 x) (t : Set α) :
s \ t ∈ 𝓝[tᶜ] x :=
diff_mem_inf_principal_compl hs t
#align diff_mem_nhds_within_compl diff_mem_nhdsWithin_compl
theorem diff_mem_nhdsWithin_diff {x : α} {s t : Set α} (hs : s ∈ 𝓝[t] x) (t' : Set α) :
s \ t' ∈ 𝓝[t \ t'] x := by
rw [nhdsWithin, diff_eq, diff_eq, ← inf_principal, ← inf_assoc]
exact inter_mem_inf hs (mem_principal_self _)
#align diff_mem_nhds_within_diff diff_mem_nhdsWithin_diff
theorem nhds_of_nhdsWithin_of_nhds {s t : Set α} {a : α} (h1 : s ∈ 𝓝 a) (h2 : t ∈ 𝓝[s] a) :
t ∈ 𝓝 a := by
rcases mem_nhdsWithin_iff_exists_mem_nhds_inter.mp h2 with ⟨_, Hw, hw⟩
exact (𝓝 a).sets_of_superset ((𝓝 a).inter_sets Hw h1) hw
#align nhds_of_nhds_within_of_nhds nhds_of_nhdsWithin_of_nhds
theorem mem_nhdsWithin_iff_eventually {s t : Set α} {x : α} :
t ∈ 𝓝[s] x ↔ ∀ᶠ y in 𝓝 x, y ∈ s → y ∈ t :=
eventually_inf_principal
#align mem_nhds_within_iff_eventually mem_nhdsWithin_iff_eventually
theorem mem_nhdsWithin_iff_eventuallyEq {s t : Set α} {x : α} :
t ∈ 𝓝[s] x ↔ s =ᶠ[𝓝 x] (s ∩ t : Set α) := by
simp_rw [mem_nhdsWithin_iff_eventually, eventuallyEq_set, mem_inter_iff, iff_self_and]
#align mem_nhds_within_iff_eventually_eq mem_nhdsWithin_iff_eventuallyEq
theorem nhdsWithin_eq_iff_eventuallyEq {s t : Set α} {x : α} : 𝓝[s] x = 𝓝[t] x ↔ s =ᶠ[𝓝 x] t :=
set_eventuallyEq_iff_inf_principal.symm
#align nhds_within_eq_iff_eventually_eq nhdsWithin_eq_iff_eventuallyEq
theorem nhdsWithin_le_iff {s t : Set α} {x : α} : 𝓝[s] x ≤ 𝓝[t] x ↔ t ∈ 𝓝[s] x :=
set_eventuallyLE_iff_inf_principal_le.symm.trans set_eventuallyLE_iff_mem_inf_principal
#align nhds_within_le_iff nhdsWithin_le_iff
-- Porting note: golfed, dropped an unneeded assumption
theorem preimage_nhdsWithin_coinduced' {π : α → β} {s : Set β} {t : Set α} {a : α} (h : a ∈ t)
(hs : s ∈ @nhds β (.coinduced (fun x : t => π x) inferInstance) (π a)) :
π ⁻¹' s ∈ 𝓝[t] a := by
lift a to t using h
replace hs : (fun x : t => π x) ⁻¹' s ∈ 𝓝 a := preimage_nhds_coinduced hs
rwa [← map_nhds_subtype_val, mem_map]
#align preimage_nhds_within_coinduced' preimage_nhdsWithin_coinduced'ₓ
theorem mem_nhdsWithin_of_mem_nhds {s t : Set α} {a : α} (h : s ∈ 𝓝 a) : s ∈ 𝓝[t] a :=
mem_inf_of_left h
#align mem_nhds_within_of_mem_nhds mem_nhdsWithin_of_mem_nhds
theorem self_mem_nhdsWithin {a : α} {s : Set α} : s ∈ 𝓝[s] a :=
mem_inf_of_right (mem_principal_self s)
#align self_mem_nhds_within self_mem_nhdsWithin
theorem eventually_mem_nhdsWithin {a : α} {s : Set α} : ∀ᶠ x in 𝓝[s] a, x ∈ s :=
self_mem_nhdsWithin
#align eventually_mem_nhds_within eventually_mem_nhdsWithin
theorem inter_mem_nhdsWithin (s : Set α) {t : Set α} {a : α} (h : t ∈ 𝓝 a) : s ∩ t ∈ 𝓝[s] a :=
inter_mem self_mem_nhdsWithin (mem_inf_of_left h)
#align inter_mem_nhds_within inter_mem_nhdsWithin
theorem nhdsWithin_mono (a : α) {s t : Set α} (h : s ⊆ t) : 𝓝[s] a ≤ 𝓝[t] a :=
inf_le_inf_left _ (principal_mono.mpr h)
#align nhds_within_mono nhdsWithin_mono
theorem pure_le_nhdsWithin {a : α} {s : Set α} (ha : a ∈ s) : pure a ≤ 𝓝[s] a :=
le_inf (pure_le_nhds a) (le_principal_iff.2 ha)
#align pure_le_nhds_within pure_le_nhdsWithin
theorem mem_of_mem_nhdsWithin {a : α} {s t : Set α} (ha : a ∈ s) (ht : t ∈ 𝓝[s] a) : a ∈ t :=
pure_le_nhdsWithin ha ht
#align mem_of_mem_nhds_within mem_of_mem_nhdsWithin
theorem Filter.Eventually.self_of_nhdsWithin {p : α → Prop} {s : Set α} {x : α}
(h : ∀ᶠ y in 𝓝[s] x, p y) (hx : x ∈ s) : p x :=
mem_of_mem_nhdsWithin hx h
#align filter.eventually.self_of_nhds_within Filter.Eventually.self_of_nhdsWithin
theorem tendsto_const_nhdsWithin {l : Filter β} {s : Set α} {a : α} (ha : a ∈ s) :
Tendsto (fun _ : β => a) l (𝓝[s] a) :=
tendsto_const_pure.mono_right <| pure_le_nhdsWithin ha
#align tendsto_const_nhds_within tendsto_const_nhdsWithin
theorem nhdsWithin_restrict'' {a : α} (s : Set α) {t : Set α} (h : t ∈ 𝓝[s] a) :
𝓝[s] a = 𝓝[s ∩ t] a :=
le_antisymm (le_inf inf_le_left (le_principal_iff.mpr (inter_mem self_mem_nhdsWithin h)))
(inf_le_inf_left _ (principal_mono.mpr Set.inter_subset_left))
#align nhds_within_restrict'' nhdsWithin_restrict''
theorem nhdsWithin_restrict' {a : α} (s : Set α) {t : Set α} (h : t ∈ 𝓝 a) : 𝓝[s] a = 𝓝[s ∩ t] a :=
nhdsWithin_restrict'' s <| mem_inf_of_left h
#align nhds_within_restrict' nhdsWithin_restrict'
theorem nhdsWithin_restrict {a : α} (s : Set α) {t : Set α} (h₀ : a ∈ t) (h₁ : IsOpen t) :
𝓝[s] a = 𝓝[s ∩ t] a :=
nhdsWithin_restrict' s (IsOpen.mem_nhds h₁ h₀)
#align nhds_within_restrict nhdsWithin_restrict
theorem nhdsWithin_le_of_mem {a : α} {s t : Set α} (h : s ∈ 𝓝[t] a) : 𝓝[t] a ≤ 𝓝[s] a :=
nhdsWithin_le_iff.mpr h
#align nhds_within_le_of_mem nhdsWithin_le_of_mem
theorem nhdsWithin_le_nhds {a : α} {s : Set α} : 𝓝[s] a ≤ 𝓝 a := by
rw [← nhdsWithin_univ]
apply nhdsWithin_le_of_mem
exact univ_mem
#align nhds_within_le_nhds nhdsWithin_le_nhds
theorem nhdsWithin_eq_nhdsWithin' {a : α} {s t u : Set α} (hs : s ∈ 𝓝 a) (h₂ : t ∩ s = u ∩ s) :
𝓝[t] a = 𝓝[u] a := by rw [nhdsWithin_restrict' t hs, nhdsWithin_restrict' u hs, h₂]
#align nhds_within_eq_nhds_within' nhdsWithin_eq_nhdsWithin'
theorem nhdsWithin_eq_nhdsWithin {a : α} {s t u : Set α} (h₀ : a ∈ s) (h₁ : IsOpen s)
(h₂ : t ∩ s = u ∩ s) : 𝓝[t] a = 𝓝[u] a := by
rw [nhdsWithin_restrict t h₀ h₁, nhdsWithin_restrict u h₀ h₁, h₂]
#align nhds_within_eq_nhds_within nhdsWithin_eq_nhdsWithin
@[simp] theorem nhdsWithin_eq_nhds {a : α} {s : Set α} : 𝓝[s] a = 𝓝 a ↔ s ∈ 𝓝 a :=
inf_eq_left.trans le_principal_iff
#align nhds_within_eq_nhds nhdsWithin_eq_nhds
theorem IsOpen.nhdsWithin_eq {a : α} {s : Set α} (h : IsOpen s) (ha : a ∈ s) : 𝓝[s] a = 𝓝 a :=
nhdsWithin_eq_nhds.2 <| h.mem_nhds ha
#align is_open.nhds_within_eq IsOpen.nhdsWithin_eq
theorem preimage_nhds_within_coinduced {π : α → β} {s : Set β} {t : Set α} {a : α} (h : a ∈ t)
(ht : IsOpen t)
(hs : s ∈ @nhds β (.coinduced (fun x : t => π x) inferInstance) (π a)) :
π ⁻¹' s ∈ 𝓝 a := by
rw [← ht.nhdsWithin_eq h]
exact preimage_nhdsWithin_coinduced' h hs
#align preimage_nhds_within_coinduced preimage_nhds_within_coinduced
@[simp]
theorem nhdsWithin_empty (a : α) : 𝓝[∅] a = ⊥ := by rw [nhdsWithin, principal_empty, inf_bot_eq]
#align nhds_within_empty nhdsWithin_empty
theorem nhdsWithin_union (a : α) (s t : Set α) : 𝓝[s ∪ t] a = 𝓝[s] a ⊔ 𝓝[t] a := by
delta nhdsWithin
rw [← inf_sup_left, sup_principal]
#align nhds_within_union nhdsWithin_union
theorem nhdsWithin_biUnion {ι} {I : Set ι} (hI : I.Finite) (s : ι → Set α) (a : α) :
𝓝[⋃ i ∈ I, s i] a = ⨆ i ∈ I, 𝓝[s i] a :=
Set.Finite.induction_on hI (by simp) fun _ _ hT ↦ by
simp only [hT, nhdsWithin_union, iSup_insert, biUnion_insert]
#align nhds_within_bUnion nhdsWithin_biUnion
theorem nhdsWithin_sUnion {S : Set (Set α)} (hS : S.Finite) (a : α) :
𝓝[⋃₀ S] a = ⨆ s ∈ S, 𝓝[s] a := by
rw [sUnion_eq_biUnion, nhdsWithin_biUnion hS]
#align nhds_within_sUnion nhdsWithin_sUnion
theorem nhdsWithin_iUnion {ι} [Finite ι] (s : ι → Set α) (a : α) :
𝓝[⋃ i, s i] a = ⨆ i, 𝓝[s i] a := by
rw [← sUnion_range, nhdsWithin_sUnion (finite_range s), iSup_range]
#align nhds_within_Union nhdsWithin_iUnion
theorem nhdsWithin_inter (a : α) (s t : Set α) : 𝓝[s ∩ t] a = 𝓝[s] a ⊓ 𝓝[t] a := by
delta nhdsWithin
rw [inf_left_comm, inf_assoc, inf_principal, ← inf_assoc, inf_idem]
#align nhds_within_inter nhdsWithin_inter
theorem nhdsWithin_inter' (a : α) (s t : Set α) : 𝓝[s ∩ t] a = 𝓝[s] a ⊓ 𝓟 t := by
delta nhdsWithin
rw [← inf_principal, inf_assoc]
#align nhds_within_inter' nhdsWithin_inter'
theorem nhdsWithin_inter_of_mem {a : α} {s t : Set α} (h : s ∈ 𝓝[t] a) : 𝓝[s ∩ t] a = 𝓝[t] a := by
rw [nhdsWithin_inter, inf_eq_right]
exact nhdsWithin_le_of_mem h
#align nhds_within_inter_of_mem nhdsWithin_inter_of_mem
theorem nhdsWithin_inter_of_mem' {a : α} {s t : Set α} (h : t ∈ 𝓝[s] a) : 𝓝[s ∩ t] a = 𝓝[s] a := by
rw [inter_comm, nhdsWithin_inter_of_mem h]
#align nhds_within_inter_of_mem' nhdsWithin_inter_of_mem'
@[simp]
theorem nhdsWithin_singleton (a : α) : 𝓝[{a}] a = pure a := by
rw [nhdsWithin, principal_singleton, inf_eq_right.2 (pure_le_nhds a)]
#align nhds_within_singleton nhdsWithin_singleton
@[simp]
theorem nhdsWithin_insert (a : α) (s : Set α) : 𝓝[insert a s] a = pure a ⊔ 𝓝[s] a := by
rw [← singleton_union, nhdsWithin_union, nhdsWithin_singleton]
#align nhds_within_insert nhdsWithin_insert
theorem mem_nhdsWithin_insert {a : α} {s t : Set α} : t ∈ 𝓝[insert a s] a ↔ a ∈ t ∧ t ∈ 𝓝[s] a := by
simp
#align mem_nhds_within_insert mem_nhdsWithin_insert
theorem insert_mem_nhdsWithin_insert {a : α} {s t : Set α} (h : t ∈ 𝓝[s] a) :
insert a t ∈ 𝓝[insert a s] a := by simp [mem_of_superset h]
#align insert_mem_nhds_within_insert insert_mem_nhdsWithin_insert
theorem insert_mem_nhds_iff {a : α} {s : Set α} : insert a s ∈ 𝓝 a ↔ s ∈ 𝓝[≠] a := by
simp only [nhdsWithin, mem_inf_principal, mem_compl_iff, mem_singleton_iff, or_iff_not_imp_left,
insert_def]
#align insert_mem_nhds_iff insert_mem_nhds_iff
@[simp]
theorem nhdsWithin_compl_singleton_sup_pure (a : α) : 𝓝[≠] a ⊔ pure a = 𝓝 a := by
rw [← nhdsWithin_singleton, ← nhdsWithin_union, compl_union_self, nhdsWithin_univ]
#align nhds_within_compl_singleton_sup_pure nhdsWithin_compl_singleton_sup_pure
theorem nhdsWithin_prod {α : Type*} [TopologicalSpace α] {β : Type*} [TopologicalSpace β]
{s u : Set α} {t v : Set β} {a : α} {b : β} (hu : u ∈ 𝓝[s] a) (hv : v ∈ 𝓝[t] b) :
u ×ˢ v ∈ 𝓝[s ×ˢ t] (a, b) := by
rw [nhdsWithin_prod_eq]
exact prod_mem_prod hu hv
#align nhds_within_prod nhdsWithin_prod
theorem nhdsWithin_pi_eq' {ι : Type*} {α : ι → Type*} [∀ i, TopologicalSpace (α i)] {I : Set ι}
(hI : I.Finite) (s : ∀ i, Set (α i)) (x : ∀ i, α i) :
𝓝[pi I s] x = ⨅ i, comap (fun x => x i) (𝓝 (x i) ⊓ ⨅ (_ : i ∈ I), 𝓟 (s i)) := by
simp only [nhdsWithin, nhds_pi, Filter.pi, comap_inf, comap_iInf, pi_def, comap_principal, ←
iInf_principal_finite hI, ← iInf_inf_eq]
#align nhds_within_pi_eq' nhdsWithin_pi_eq'
theorem nhdsWithin_pi_eq {ι : Type*} {α : ι → Type*} [∀ i, TopologicalSpace (α i)] {I : Set ι}
(hI : I.Finite) (s : ∀ i, Set (α i)) (x : ∀ i, α i) :
𝓝[pi I s] x =
(⨅ i ∈ I, comap (fun x => x i) (𝓝[s i] x i)) ⊓
⨅ (i) (_ : i ∉ I), comap (fun x => x i) (𝓝 (x i)) := by
simp only [nhdsWithin, nhds_pi, Filter.pi, pi_def, ← iInf_principal_finite hI, comap_inf,
comap_principal, eval]
rw [iInf_split _ fun i => i ∈ I, inf_right_comm]
simp only [iInf_inf_eq]
#align nhds_within_pi_eq nhdsWithin_pi_eq
theorem nhdsWithin_pi_univ_eq {ι : Type*} {α : ι → Type*} [Finite ι] [∀ i, TopologicalSpace (α i)]
(s : ∀ i, Set (α i)) (x : ∀ i, α i) :
𝓝[pi univ s] x = ⨅ i, comap (fun x => x i) (𝓝[s i] x i) := by
simpa [nhdsWithin] using nhdsWithin_pi_eq finite_univ s x
#align nhds_within_pi_univ_eq nhdsWithin_pi_univ_eq
theorem nhdsWithin_pi_eq_bot {ι : Type*} {α : ι → Type*} [∀ i, TopologicalSpace (α i)] {I : Set ι}
{s : ∀ i, Set (α i)} {x : ∀ i, α i} : 𝓝[pi I s] x = ⊥ ↔ ∃ i ∈ I, 𝓝[s i] x i = ⊥ := by
simp only [nhdsWithin, nhds_pi, pi_inf_principal_pi_eq_bot]
#align nhds_within_pi_eq_bot nhdsWithin_pi_eq_bot
theorem nhdsWithin_pi_neBot {ι : Type*} {α : ι → Type*} [∀ i, TopologicalSpace (α i)] {I : Set ι}
{s : ∀ i, Set (α i)} {x : ∀ i, α i} : (𝓝[pi I s] x).NeBot ↔ ∀ i ∈ I, (𝓝[s i] x i).NeBot := by
simp [neBot_iff, nhdsWithin_pi_eq_bot]
#align nhds_within_pi_ne_bot nhdsWithin_pi_neBot
theorem Filter.Tendsto.piecewise_nhdsWithin {f g : α → β} {t : Set α} [∀ x, Decidable (x ∈ t)]
{a : α} {s : Set α} {l : Filter β} (h₀ : Tendsto f (𝓝[s ∩ t] a) l)
(h₁ : Tendsto g (𝓝[s ∩ tᶜ] a) l) : Tendsto (piecewise t f g) (𝓝[s] a) l := by
apply Tendsto.piecewise <;> rwa [← nhdsWithin_inter']
#align filter.tendsto.piecewise_nhds_within Filter.Tendsto.piecewise_nhdsWithin
theorem Filter.Tendsto.if_nhdsWithin {f g : α → β} {p : α → Prop} [DecidablePred p] {a : α}
{s : Set α} {l : Filter β} (h₀ : Tendsto f (𝓝[s ∩ { x | p x }] a) l)
(h₁ : Tendsto g (𝓝[s ∩ { x | ¬p x }] a) l) :
Tendsto (fun x => if p x then f x else g x) (𝓝[s] a) l :=
h₀.piecewise_nhdsWithin h₁
#align filter.tendsto.if_nhds_within Filter.Tendsto.if_nhdsWithin
theorem map_nhdsWithin (f : α → β) (a : α) (s : Set α) :
map f (𝓝[s] a) = ⨅ t ∈ { t : Set α | a ∈ t ∧ IsOpen t }, 𝓟 (f '' (t ∩ s)) :=
((nhdsWithin_basis_open a s).map f).eq_biInf
#align map_nhds_within map_nhdsWithin
theorem tendsto_nhdsWithin_mono_left {f : α → β} {a : α} {s t : Set α} {l : Filter β} (hst : s ⊆ t)
(h : Tendsto f (𝓝[t] a) l) : Tendsto f (𝓝[s] a) l :=
h.mono_left <| nhdsWithin_mono a hst
#align tendsto_nhds_within_mono_left tendsto_nhdsWithin_mono_left
theorem tendsto_nhdsWithin_mono_right {f : β → α} {l : Filter β} {a : α} {s t : Set α} (hst : s ⊆ t)
(h : Tendsto f l (𝓝[s] a)) : Tendsto f l (𝓝[t] a) :=
h.mono_right (nhdsWithin_mono a hst)
#align tendsto_nhds_within_mono_right tendsto_nhdsWithin_mono_right
theorem tendsto_nhdsWithin_of_tendsto_nhds {f : α → β} {a : α} {s : Set α} {l : Filter β}
(h : Tendsto f (𝓝 a) l) : Tendsto f (𝓝[s] a) l :=
h.mono_left inf_le_left
#align tendsto_nhds_within_of_tendsto_nhds tendsto_nhdsWithin_of_tendsto_nhds
theorem eventually_mem_of_tendsto_nhdsWithin {f : β → α} {a : α} {s : Set α} {l : Filter β}
(h : Tendsto f l (𝓝[s] a)) : ∀ᶠ i in l, f i ∈ s := by
simp_rw [nhdsWithin_eq, tendsto_iInf, mem_setOf_eq, tendsto_principal, mem_inter_iff,
eventually_and] at h
exact (h univ ⟨mem_univ a, isOpen_univ⟩).2
#align eventually_mem_of_tendsto_nhds_within eventually_mem_of_tendsto_nhdsWithin
theorem tendsto_nhds_of_tendsto_nhdsWithin {f : β → α} {a : α} {s : Set α} {l : Filter β}
(h : Tendsto f l (𝓝[s] a)) : Tendsto f l (𝓝 a) :=
h.mono_right nhdsWithin_le_nhds
#align tendsto_nhds_of_tendsto_nhds_within tendsto_nhds_of_tendsto_nhdsWithin
theorem nhdsWithin_neBot_of_mem {s : Set α} {x : α} (hx : x ∈ s) : NeBot (𝓝[s] x) :=
mem_closure_iff_nhdsWithin_neBot.1 <| subset_closure hx
#align nhds_within_ne_bot_of_mem nhdsWithin_neBot_of_mem
theorem IsClosed.mem_of_nhdsWithin_neBot {s : Set α} (hs : IsClosed s) {x : α}
(hx : NeBot <| 𝓝[s] x) : x ∈ s :=
hs.closure_eq ▸ mem_closure_iff_nhdsWithin_neBot.2 hx
#align is_closed.mem_of_nhds_within_ne_bot IsClosed.mem_of_nhdsWithin_neBot
theorem DenseRange.nhdsWithin_neBot {ι : Type*} {f : ι → α} (h : DenseRange f) (x : α) :
NeBot (𝓝[range f] x) :=
mem_closure_iff_clusterPt.1 (h x)
#align dense_range.nhds_within_ne_bot DenseRange.nhdsWithin_neBot
theorem mem_closure_pi {ι : Type*} {α : ι → Type*} [∀ i, TopologicalSpace (α i)] {I : Set ι}
{s : ∀ i, Set (α i)} {x : ∀ i, α i} : x ∈ closure (pi I s) ↔ ∀ i ∈ I, x i ∈ closure (s i) := by
simp only [mem_closure_iff_nhdsWithin_neBot, nhdsWithin_pi_neBot]
#align mem_closure_pi mem_closure_pi
theorem closure_pi_set {ι : Type*} {α : ι → Type*} [∀ i, TopologicalSpace (α i)] (I : Set ι)
(s : ∀ i, Set (α i)) : closure (pi I s) = pi I fun i => closure (s i) :=
Set.ext fun _ => mem_closure_pi
#align closure_pi_set closure_pi_set
theorem dense_pi {ι : Type*} {α : ι → Type*} [∀ i, TopologicalSpace (α i)] {s : ∀ i, Set (α i)}
(I : Set ι) (hs : ∀ i ∈ I, Dense (s i)) : Dense (pi I s) := by
simp only [dense_iff_closure_eq, closure_pi_set, pi_congr rfl fun i hi => (hs i hi).closure_eq,
pi_univ]
#align dense_pi dense_pi
theorem eventuallyEq_nhdsWithin_iff {f g : α → β} {s : Set α} {a : α} :
f =ᶠ[𝓝[s] a] g ↔ ∀ᶠ x in 𝓝 a, x ∈ s → f x = g x :=
mem_inf_principal
#align eventually_eq_nhds_within_iff eventuallyEq_nhdsWithin_iff
theorem eventuallyEq_nhdsWithin_of_eqOn {f g : α → β} {s : Set α} {a : α} (h : EqOn f g s) :
f =ᶠ[𝓝[s] a] g :=
mem_inf_of_right h
#align eventually_eq_nhds_within_of_eq_on eventuallyEq_nhdsWithin_of_eqOn
theorem Set.EqOn.eventuallyEq_nhdsWithin {f g : α → β} {s : Set α} {a : α} (h : EqOn f g s) :
f =ᶠ[𝓝[s] a] g :=
eventuallyEq_nhdsWithin_of_eqOn h
#align set.eq_on.eventually_eq_nhds_within Set.EqOn.eventuallyEq_nhdsWithin
theorem tendsto_nhdsWithin_congr {f g : α → β} {s : Set α} {a : α} {l : Filter β}
(hfg : ∀ x ∈ s, f x = g x) (hf : Tendsto f (𝓝[s] a) l) : Tendsto g (𝓝[s] a) l :=
(tendsto_congr' <| eventuallyEq_nhdsWithin_of_eqOn hfg).1 hf
#align tendsto_nhds_within_congr tendsto_nhdsWithin_congr
theorem eventually_nhdsWithin_of_forall {s : Set α} {a : α} {p : α → Prop} (h : ∀ x ∈ s, p x) :
∀ᶠ x in 𝓝[s] a, p x :=
mem_inf_of_right h
#align eventually_nhds_within_of_forall eventually_nhdsWithin_of_forall
theorem tendsto_nhdsWithin_of_tendsto_nhds_of_eventually_within {a : α} {l : Filter β} {s : Set α}
(f : β → α) (h1 : Tendsto f l (𝓝 a)) (h2 : ∀ᶠ x in l, f x ∈ s) : Tendsto f l (𝓝[s] a) :=
tendsto_inf.2 ⟨h1, tendsto_principal.2 h2⟩
#align tendsto_nhds_within_of_tendsto_nhds_of_eventually_within tendsto_nhdsWithin_of_tendsto_nhds_of_eventually_within
theorem tendsto_nhdsWithin_iff {a : α} {l : Filter β} {s : Set α} {f : β → α} :
Tendsto f l (𝓝[s] a) ↔ Tendsto f l (𝓝 a) ∧ ∀ᶠ n in l, f n ∈ s :=
⟨fun h => ⟨tendsto_nhds_of_tendsto_nhdsWithin h, eventually_mem_of_tendsto_nhdsWithin h⟩, fun h =>
tendsto_nhdsWithin_of_tendsto_nhds_of_eventually_within _ h.1 h.2⟩
#align tendsto_nhds_within_iff tendsto_nhdsWithin_iff
@[simp]
theorem tendsto_nhdsWithin_range {a : α} {l : Filter β} {f : β → α} :
Tendsto f l (𝓝[range f] a) ↔ Tendsto f l (𝓝 a) :=
⟨fun h => h.mono_right inf_le_left, fun h =>
tendsto_inf.2 ⟨h, tendsto_principal.2 <| eventually_of_forall mem_range_self⟩⟩
#align tendsto_nhds_within_range tendsto_nhdsWithin_range
theorem Filter.EventuallyEq.eq_of_nhdsWithin {s : Set α} {f g : α → β} {a : α} (h : f =ᶠ[𝓝[s] a] g)
(hmem : a ∈ s) : f a = g a :=
h.self_of_nhdsWithin hmem
#align filter.eventually_eq.eq_of_nhds_within Filter.EventuallyEq.eq_of_nhdsWithin
theorem eventually_nhdsWithin_of_eventually_nhds {α : Type*} [TopologicalSpace α] {s : Set α}
{a : α} {p : α → Prop} (h : ∀ᶠ x in 𝓝 a, p x) : ∀ᶠ x in 𝓝[s] a, p x :=
mem_nhdsWithin_of_mem_nhds h
#align eventually_nhds_within_of_eventually_nhds eventually_nhdsWithin_of_eventually_nhds
theorem mem_nhdsWithin_subtype {s : Set α} {a : { x // x ∈ s }} {t u : Set { x // x ∈ s }} :
t ∈ 𝓝[u] a ↔ t ∈ comap ((↑) : s → α) (𝓝[(↑) '' u] a) := by
rw [nhdsWithin, nhds_subtype, principal_subtype, ← comap_inf, ← nhdsWithin]
#align mem_nhds_within_subtype mem_nhdsWithin_subtype
theorem nhdsWithin_subtype (s : Set α) (a : { x // x ∈ s }) (t : Set { x // x ∈ s }) :
𝓝[t] a = comap ((↑) : s → α) (𝓝[(↑) '' t] a) :=
Filter.ext fun _ => mem_nhdsWithin_subtype
#align nhds_within_subtype nhdsWithin_subtype
theorem nhdsWithin_eq_map_subtype_coe {s : Set α} {a : α} (h : a ∈ s) :
𝓝[s] a = map ((↑) : s → α) (𝓝 ⟨a, h⟩) :=
(map_nhds_subtype_val ⟨a, h⟩).symm
#align nhds_within_eq_map_subtype_coe nhdsWithin_eq_map_subtype_coe
theorem mem_nhds_subtype_iff_nhdsWithin {s : Set α} {a : s} {t : Set s} :
t ∈ 𝓝 a ↔ (↑) '' t ∈ 𝓝[s] (a : α) := by
rw [← map_nhds_subtype_val, image_mem_map_iff Subtype.val_injective]
#align mem_nhds_subtype_iff_nhds_within mem_nhds_subtype_iff_nhdsWithin
theorem preimage_coe_mem_nhds_subtype {s t : Set α} {a : s} : (↑) ⁻¹' t ∈ 𝓝 a ↔ t ∈ 𝓝[s] ↑a := by
rw [← map_nhds_subtype_val, mem_map]
#align preimage_coe_mem_nhds_subtype preimage_coe_mem_nhds_subtype
theorem eventually_nhds_subtype_iff (s : Set α) (a : s) (P : α → Prop) :
(∀ᶠ x : s in 𝓝 a, P x) ↔ ∀ᶠ x in 𝓝[s] a, P x :=
preimage_coe_mem_nhds_subtype
theorem frequently_nhds_subtype_iff (s : Set α) (a : s) (P : α → Prop) :
(∃ᶠ x : s in 𝓝 a, P x) ↔ ∃ᶠ x in 𝓝[s] a, P x :=
eventually_nhds_subtype_iff s a (¬ P ·) |>.not
theorem tendsto_nhdsWithin_iff_subtype {s : Set α} {a : α} (h : a ∈ s) (f : α → β) (l : Filter β) :
Tendsto f (𝓝[s] a) l ↔ Tendsto (s.restrict f) (𝓝 ⟨a, h⟩) l := by
rw [nhdsWithin_eq_map_subtype_coe h, tendsto_map'_iff]; rfl
#align tendsto_nhds_within_iff_subtype tendsto_nhdsWithin_iff_subtype
variable [TopologicalSpace β] [TopologicalSpace γ] [TopologicalSpace δ]
theorem ContinuousWithinAt.tendsto {f : α → β} {s : Set α} {x : α} (h : ContinuousWithinAt f s x) :
Tendsto f (𝓝[s] x) (𝓝 (f x)) :=
h
#align continuous_within_at.tendsto ContinuousWithinAt.tendsto
theorem ContinuousOn.continuousWithinAt {f : α → β} {s : Set α} {x : α} (hf : ContinuousOn f s)
(hx : x ∈ s) : ContinuousWithinAt f s x :=
hf x hx
#align continuous_on.continuous_within_at ContinuousOn.continuousWithinAt
theorem continuousWithinAt_univ (f : α → β) (x : α) :
ContinuousWithinAt f Set.univ x ↔ ContinuousAt f x := by
rw [ContinuousAt, ContinuousWithinAt, nhdsWithin_univ]
#align continuous_within_at_univ continuousWithinAt_univ
theorem continuous_iff_continuousOn_univ {f : α → β} : Continuous f ↔ ContinuousOn f univ := by
simp [continuous_iff_continuousAt, ContinuousOn, ContinuousAt, ContinuousWithinAt,
nhdsWithin_univ]
#align continuous_iff_continuous_on_univ continuous_iff_continuousOn_univ
theorem continuousWithinAt_iff_continuousAt_restrict (f : α → β) {x : α} {s : Set α} (h : x ∈ s) :
ContinuousWithinAt f s x ↔ ContinuousAt (s.restrict f) ⟨x, h⟩ :=
tendsto_nhdsWithin_iff_subtype h f _
#align continuous_within_at_iff_continuous_at_restrict continuousWithinAt_iff_continuousAt_restrict
theorem ContinuousWithinAt.tendsto_nhdsWithin {f : α → β} {x : α} {s : Set α} {t : Set β}
(h : ContinuousWithinAt f s x) (ht : MapsTo f s t) : Tendsto f (𝓝[s] x) (𝓝[t] f x) :=
tendsto_inf.2 ⟨h, tendsto_principal.2 <| mem_inf_of_right <| mem_principal.2 <| ht⟩
#align continuous_within_at.tendsto_nhds_within ContinuousWithinAt.tendsto_nhdsWithin
theorem ContinuousWithinAt.tendsto_nhdsWithin_image {f : α → β} {x : α} {s : Set α}
(h : ContinuousWithinAt f s x) : Tendsto f (𝓝[s] x) (𝓝[f '' s] f x) :=
h.tendsto_nhdsWithin (mapsTo_image _ _)
#align continuous_within_at.tendsto_nhds_within_image ContinuousWithinAt.tendsto_nhdsWithin_image
theorem ContinuousWithinAt.prod_map {f : α → γ} {g : β → δ} {s : Set α} {t : Set β} {x : α} {y : β}
(hf : ContinuousWithinAt f s x) (hg : ContinuousWithinAt g t y) :
ContinuousWithinAt (Prod.map f g) (s ×ˢ t) (x, y) := by
unfold ContinuousWithinAt at *
rw [nhdsWithin_prod_eq, Prod.map, nhds_prod_eq]
exact hf.prod_map hg
#align continuous_within_at.prod_map ContinuousWithinAt.prod_map
theorem continuousWithinAt_prod_of_discrete_left [DiscreteTopology α]
{f : α × β → γ} {s : Set (α × β)} {x : α × β} :
ContinuousWithinAt f s x ↔ ContinuousWithinAt (f ⟨x.1, ·⟩) {b | (x.1, b) ∈ s} x.2 := by
rw [← x.eta]; simp_rw [ContinuousWithinAt, nhdsWithin, nhds_prod_eq, nhds_discrete, pure_prod,
← map_inf_principal_preimage]; rfl
theorem continuousWithinAt_prod_of_discrete_right [DiscreteTopology β]
{f : α × β → γ} {s : Set (α × β)} {x : α × β} :
ContinuousWithinAt f s x ↔ ContinuousWithinAt (f ⟨·, x.2⟩) {a | (a, x.2) ∈ s} x.1 := by
rw [← x.eta]; simp_rw [ContinuousWithinAt, nhdsWithin, nhds_prod_eq, nhds_discrete, prod_pure,
← map_inf_principal_preimage]; rfl
theorem continuousAt_prod_of_discrete_left [DiscreteTopology α] {f : α × β → γ} {x : α × β} :
ContinuousAt f x ↔ ContinuousAt (f ⟨x.1, ·⟩) x.2 := by
simp_rw [← continuousWithinAt_univ]; exact continuousWithinAt_prod_of_discrete_left
theorem continuousAt_prod_of_discrete_right [DiscreteTopology β] {f : α × β → γ} {x : α × β} :
ContinuousAt f x ↔ ContinuousAt (f ⟨·, x.2⟩) x.1 := by
simp_rw [← continuousWithinAt_univ]; exact continuousWithinAt_prod_of_discrete_right
theorem continuousOn_prod_of_discrete_left [DiscreteTopology α] {f : α × β → γ} {s : Set (α × β)} :
ContinuousOn f s ↔ ∀ a, ContinuousOn (f ⟨a, ·⟩) {b | (a, b) ∈ s} := by
simp_rw [ContinuousOn, Prod.forall, continuousWithinAt_prod_of_discrete_left]; rfl
theorem continuousOn_prod_of_discrete_right [DiscreteTopology β] {f : α × β → γ} {s : Set (α × β)} :
ContinuousOn f s ↔ ∀ b, ContinuousOn (f ⟨·, b⟩) {a | (a, b) ∈ s} := by
simp_rw [ContinuousOn, Prod.forall, continuousWithinAt_prod_of_discrete_right]; apply forall_swap
theorem continuous_prod_of_discrete_left [DiscreteTopology α] {f : α × β → γ} :
Continuous f ↔ ∀ a, Continuous (f ⟨a, ·⟩) := by
simp_rw [continuous_iff_continuousOn_univ]; exact continuousOn_prod_of_discrete_left
theorem continuous_prod_of_discrete_right [DiscreteTopology β] {f : α × β → γ} :
Continuous f ↔ ∀ b, Continuous (f ⟨·, b⟩) := by
simp_rw [continuous_iff_continuousOn_univ]; exact continuousOn_prod_of_discrete_right
theorem isOpenMap_prod_of_discrete_left [DiscreteTopology α] {f : α × β → γ} :
IsOpenMap f ↔ ∀ a, IsOpenMap (f ⟨a, ·⟩) := by
simp_rw [isOpenMap_iff_nhds_le, Prod.forall, nhds_prod_eq, nhds_discrete, pure_prod, map_map]
rfl
theorem isOpenMap_prod_of_discrete_right [DiscreteTopology β] {f : α × β → γ} :
IsOpenMap f ↔ ∀ b, IsOpenMap (f ⟨·, b⟩) := by
simp_rw [isOpenMap_iff_nhds_le, Prod.forall, forall_swap (α := α) (β := β), nhds_prod_eq,
nhds_discrete, prod_pure, map_map]; rfl
theorem continuousWithinAt_pi {ι : Type*} {π : ι → Type*} [∀ i, TopologicalSpace (π i)]
{f : α → ∀ i, π i} {s : Set α} {x : α} :
ContinuousWithinAt f s x ↔ ∀ i, ContinuousWithinAt (fun y => f y i) s x :=
tendsto_pi_nhds
#align continuous_within_at_pi continuousWithinAt_pi
theorem continuousOn_pi {ι : Type*} {π : ι → Type*} [∀ i, TopologicalSpace (π i)]
{f : α → ∀ i, π i} {s : Set α} : ContinuousOn f s ↔ ∀ i, ContinuousOn (fun y => f y i) s :=
⟨fun h i x hx => tendsto_pi_nhds.1 (h x hx) i, fun h x hx => tendsto_pi_nhds.2 fun i => h i x hx⟩
#align continuous_on_pi continuousOn_pi
@[fun_prop]
theorem continuousOn_pi' {ι : Type*} {π : ι → Type*} [∀ i, TopologicalSpace (π i)]
{f : α → ∀ i, π i} {s : Set α} (hf : ∀ i, ContinuousOn (fun y => f y i) s) :
ContinuousOn f s :=
continuousOn_pi.2 hf
theorem ContinuousWithinAt.fin_insertNth {n} {π : Fin (n + 1) → Type*}
[∀ i, TopologicalSpace (π i)] (i : Fin (n + 1)) {f : α → π i} {a : α} {s : Set α}
(hf : ContinuousWithinAt f s a) {g : α → ∀ j : Fin n, π (i.succAbove j)}
(hg : ContinuousWithinAt g s a) : ContinuousWithinAt (fun a => i.insertNth (f a) (g a)) s a :=
hf.tendsto.fin_insertNth i hg
#align continuous_within_at.fin_insert_nth ContinuousWithinAt.fin_insertNth
nonrec theorem ContinuousOn.fin_insertNth {n} {π : Fin (n + 1) → Type*}
[∀ i, TopologicalSpace (π i)] (i : Fin (n + 1)) {f : α → π i} {s : Set α}
(hf : ContinuousOn f s) {g : α → ∀ j : Fin n, π (i.succAbove j)} (hg : ContinuousOn g s) :
ContinuousOn (fun a => i.insertNth (f a) (g a)) s := fun a ha =>
(hf a ha).fin_insertNth i (hg a ha)
#align continuous_on.fin_insert_nth ContinuousOn.fin_insertNth
theorem continuousOn_iff {f : α → β} {s : Set α} :
ContinuousOn f s ↔
∀ x ∈ s, ∀ t : Set β, IsOpen t → f x ∈ t → ∃ u, IsOpen u ∧ x ∈ u ∧ u ∩ s ⊆ f ⁻¹' t := by
simp only [ContinuousOn, ContinuousWithinAt, tendsto_nhds, mem_nhdsWithin]
#align continuous_on_iff continuousOn_iff
theorem continuousOn_iff_continuous_restrict {f : α → β} {s : Set α} :
ContinuousOn f s ↔ Continuous (s.restrict f) := by
rw [ContinuousOn, continuous_iff_continuousAt]; constructor
· rintro h ⟨x, xs⟩
exact (continuousWithinAt_iff_continuousAt_restrict f xs).mp (h x xs)
intro h x xs
exact (continuousWithinAt_iff_continuousAt_restrict f xs).mpr (h ⟨x, xs⟩)
#align continuous_on_iff_continuous_restrict continuousOn_iff_continuous_restrict
-- Porting note: 2 new lemmas
alias ⟨ContinuousOn.restrict, _⟩ := continuousOn_iff_continuous_restrict
theorem ContinuousOn.restrict_mapsTo {f : α → β} {s : Set α} {t : Set β} (hf : ContinuousOn f s)
(ht : MapsTo f s t) : Continuous (ht.restrict f s t) :=
hf.restrict.codRestrict _
theorem continuousOn_iff' {f : α → β} {s : Set α} :
ContinuousOn f s ↔ ∀ t : Set β, IsOpen t → ∃ u, IsOpen u ∧ f ⁻¹' t ∩ s = u ∩ s := by
have : ∀ t, IsOpen (s.restrict f ⁻¹' t) ↔ ∃ u : Set α, IsOpen u ∧ f ⁻¹' t ∩ s = u ∩ s := by
intro t
rw [isOpen_induced_iff, Set.restrict_eq, Set.preimage_comp]
simp only [Subtype.preimage_coe_eq_preimage_coe_iff]
constructor <;>
· rintro ⟨u, ou, useq⟩
exact ⟨u, ou, by simpa only [Set.inter_comm, eq_comm] using useq⟩
rw [continuousOn_iff_continuous_restrict, continuous_def]; simp only [this]
#align continuous_on_iff' continuousOn_iff'
theorem ContinuousOn.mono_dom {α β : Type*} {t₁ t₂ : TopologicalSpace α} {t₃ : TopologicalSpace β}
(h₁ : t₂ ≤ t₁) {s : Set α} {f : α → β} (h₂ : @ContinuousOn α β t₁ t₃ f s) :
@ContinuousOn α β t₂ t₃ f s := fun x hx _u hu =>
map_mono (inf_le_inf_right _ <| nhds_mono h₁) (h₂ x hx hu)
#align continuous_on.mono_dom ContinuousOn.mono_dom
theorem ContinuousOn.mono_rng {α β : Type*} {t₁ : TopologicalSpace α} {t₂ t₃ : TopologicalSpace β}
(h₁ : t₂ ≤ t₃) {s : Set α} {f : α → β} (h₂ : @ContinuousOn α β t₁ t₂ f s) :
@ContinuousOn α β t₁ t₃ f s := fun x hx _u hu =>
h₂ x hx <| nhds_mono h₁ hu
#align continuous_on.mono_rng ContinuousOn.mono_rng
theorem continuousOn_iff_isClosed {f : α → β} {s : Set α} :
ContinuousOn f s ↔ ∀ t : Set β, IsClosed t → ∃ u, IsClosed u ∧ f ⁻¹' t ∩ s = u ∩ s := by
have : ∀ t, IsClosed (s.restrict f ⁻¹' t) ↔ ∃ u : Set α, IsClosed u ∧ f ⁻¹' t ∩ s = u ∩ s := by
intro t
rw [isClosed_induced_iff, Set.restrict_eq, Set.preimage_comp]
simp only [Subtype.preimage_coe_eq_preimage_coe_iff, eq_comm, Set.inter_comm s]
rw [continuousOn_iff_continuous_restrict, continuous_iff_isClosed]; simp only [this]
#align continuous_on_iff_is_closed continuousOn_iff_isClosed
theorem ContinuousOn.prod_map {f : α → γ} {g : β → δ} {s : Set α} {t : Set β}
(hf : ContinuousOn f s) (hg : ContinuousOn g t) : ContinuousOn (Prod.map f g) (s ×ˢ t) :=
fun ⟨x, y⟩ ⟨hx, hy⟩ => ContinuousWithinAt.prod_map (hf x hx) (hg y hy)
#align continuous_on.prod_map ContinuousOn.prod_map
theorem continuous_of_cover_nhds {ι : Sort*} {f : α → β} {s : ι → Set α}
(hs : ∀ x : α, ∃ i, s i ∈ 𝓝 x) (hf : ∀ i, ContinuousOn f (s i)) :
Continuous f :=
continuous_iff_continuousAt.mpr fun x ↦ let ⟨i, hi⟩ := hs x; by
rw [ContinuousAt, ← nhdsWithin_eq_nhds.2 hi]
exact hf _ _ (mem_of_mem_nhds hi)
#align continuous_of_cover_nhds continuous_of_cover_nhds
theorem continuousOn_empty (f : α → β) : ContinuousOn f ∅ := fun _ => False.elim
#align continuous_on_empty continuousOn_empty
@[simp]
theorem continuousOn_singleton (f : α → β) (a : α) : ContinuousOn f {a} :=
forall_eq.2 <| by
simpa only [ContinuousWithinAt, nhdsWithin_singleton, tendsto_pure_left] using fun s =>
mem_of_mem_nhds
#align continuous_on_singleton continuousOn_singleton
theorem Set.Subsingleton.continuousOn {s : Set α} (hs : s.Subsingleton) (f : α → β) :
ContinuousOn f s :=
hs.induction_on (continuousOn_empty f) (continuousOn_singleton f)
#align set.subsingleton.continuous_on Set.Subsingleton.continuousOn
theorem nhdsWithin_le_comap {x : α} {s : Set α} {f : α → β} (ctsf : ContinuousWithinAt f s x) :
𝓝[s] x ≤ comap f (𝓝[f '' s] f x) :=
ctsf.tendsto_nhdsWithin_image.le_comap
#align nhds_within_le_comap nhdsWithin_le_comap
@[simp]
theorem comap_nhdsWithin_range {α} (f : α → β) (y : β) : comap f (𝓝[range f] y) = comap f (𝓝 y) :=
comap_inf_principal_range
#align comap_nhds_within_range comap_nhdsWithin_range
theorem ContinuousWithinAt.mono {f : α → β} {s t : Set α} {x : α} (h : ContinuousWithinAt f t x)
(hs : s ⊆ t) : ContinuousWithinAt f s x :=
h.mono_left (nhdsWithin_mono x hs)
#align continuous_within_at.mono ContinuousWithinAt.mono
theorem ContinuousWithinAt.mono_of_mem {f : α → β} {s t : Set α} {x : α}
(h : ContinuousWithinAt f t x) (hs : t ∈ 𝓝[s] x) : ContinuousWithinAt f s x :=
h.mono_left (nhdsWithin_le_of_mem hs)
#align continuous_within_at.mono_of_mem ContinuousWithinAt.mono_of_mem
theorem continuousWithinAt_congr_nhds {f : α → β} {s t : Set α} {x : α} (h : 𝓝[s] x = 𝓝[t] x) :
ContinuousWithinAt f s x ↔ ContinuousWithinAt f t x := by
simp only [ContinuousWithinAt, h]
theorem continuousWithinAt_inter' {f : α → β} {s t : Set α} {x : α} (h : t ∈ 𝓝[s] x) :
ContinuousWithinAt f (s ∩ t) x ↔ ContinuousWithinAt f s x := by
simp [ContinuousWithinAt, nhdsWithin_restrict'' s h]
#align continuous_within_at_inter' continuousWithinAt_inter'
theorem continuousWithinAt_inter {f : α → β} {s t : Set α} {x : α} (h : t ∈ 𝓝 x) :
ContinuousWithinAt f (s ∩ t) x ↔ ContinuousWithinAt f s x := by
simp [ContinuousWithinAt, nhdsWithin_restrict' s h]
#align continuous_within_at_inter continuousWithinAt_inter
theorem continuousWithinAt_union {f : α → β} {s t : Set α} {x : α} :
ContinuousWithinAt f (s ∪ t) x ↔ ContinuousWithinAt f s x ∧ ContinuousWithinAt f t x := by
simp only [ContinuousWithinAt, nhdsWithin_union, tendsto_sup]
#align continuous_within_at_union continuousWithinAt_union
theorem ContinuousWithinAt.union {f : α → β} {s t : Set α} {x : α} (hs : ContinuousWithinAt f s x)
(ht : ContinuousWithinAt f t x) : ContinuousWithinAt f (s ∪ t) x :=
continuousWithinAt_union.2 ⟨hs, ht⟩
#align continuous_within_at.union ContinuousWithinAt.union
theorem ContinuousWithinAt.mem_closure_image {f : α → β} {s : Set α} {x : α}
(h : ContinuousWithinAt f s x) (hx : x ∈ closure s) : f x ∈ closure (f '' s) :=
haveI := mem_closure_iff_nhdsWithin_neBot.1 hx
mem_closure_of_tendsto h <| mem_of_superset self_mem_nhdsWithin (subset_preimage_image f s)
#align continuous_within_at.mem_closure_image ContinuousWithinAt.mem_closure_image
theorem ContinuousWithinAt.mem_closure {f : α → β} {s : Set α} {x : α} {A : Set β}
(h : ContinuousWithinAt f s x) (hx : x ∈ closure s) (hA : MapsTo f s A) : f x ∈ closure A :=
closure_mono (image_subset_iff.2 hA) (h.mem_closure_image hx)
#align continuous_within_at.mem_closure ContinuousWithinAt.mem_closure
theorem Set.MapsTo.closure_of_continuousWithinAt {f : α → β} {s : Set α} {t : Set β}
(h : MapsTo f s t) (hc : ∀ x ∈ closure s, ContinuousWithinAt f s x) :
MapsTo f (closure s) (closure t) := fun x hx => (hc x hx).mem_closure hx h
#align set.maps_to.closure_of_continuous_within_at Set.MapsTo.closure_of_continuousWithinAt
theorem Set.MapsTo.closure_of_continuousOn {f : α → β} {s : Set α} {t : Set β} (h : MapsTo f s t)
(hc : ContinuousOn f (closure s)) : MapsTo f (closure s) (closure t) :=
h.closure_of_continuousWithinAt fun x hx => (hc x hx).mono subset_closure
#align set.maps_to.closure_of_continuous_on Set.MapsTo.closure_of_continuousOn
theorem ContinuousWithinAt.image_closure {f : α → β} {s : Set α}
(hf : ∀ x ∈ closure s, ContinuousWithinAt f s x) : f '' closure s ⊆ closure (f '' s) :=
((mapsTo_image f s).closure_of_continuousWithinAt hf).image_subset
#align continuous_within_at.image_closure ContinuousWithinAt.image_closure
theorem ContinuousOn.image_closure {f : α → β} {s : Set α} (hf : ContinuousOn f (closure s)) :
f '' closure s ⊆ closure (f '' s) :=
ContinuousWithinAt.image_closure fun x hx => (hf x hx).mono subset_closure
#align continuous_on.image_closure ContinuousOn.image_closure
@[simp]
theorem continuousWithinAt_singleton {f : α → β} {x : α} : ContinuousWithinAt f {x} x := by
simp only [ContinuousWithinAt, nhdsWithin_singleton, tendsto_pure_nhds]
#align continuous_within_at_singleton continuousWithinAt_singleton
@[simp]
theorem continuousWithinAt_insert_self {f : α → β} {x : α} {s : Set α} :
ContinuousWithinAt f (insert x s) x ↔ ContinuousWithinAt f s x := by
simp only [← singleton_union, continuousWithinAt_union, continuousWithinAt_singleton,
true_and_iff]
#align continuous_within_at_insert_self continuousWithinAt_insert_self
alias ⟨_, ContinuousWithinAt.insert_self⟩ := continuousWithinAt_insert_self
#align continuous_within_at.insert_self ContinuousWithinAt.insert_self
theorem ContinuousWithinAt.diff_iff {f : α → β} {s t : Set α} {x : α}
(ht : ContinuousWithinAt f t x) : ContinuousWithinAt f (s \ t) x ↔ ContinuousWithinAt f s x :=
⟨fun h => (h.union ht).mono <| by simp only [diff_union_self, subset_union_left], fun h =>
h.mono diff_subset⟩
#align continuous_within_at.diff_iff ContinuousWithinAt.diff_iff
@[simp]
theorem continuousWithinAt_diff_self {f : α → β} {s : Set α} {x : α} :
ContinuousWithinAt f (s \ {x}) x ↔ ContinuousWithinAt f s x :=
continuousWithinAt_singleton.diff_iff
#align continuous_within_at_diff_self continuousWithinAt_diff_self
@[simp]
theorem continuousWithinAt_compl_self {f : α → β} {a : α} :
ContinuousWithinAt f {a}ᶜ a ↔ ContinuousAt f a := by
rw [compl_eq_univ_diff, continuousWithinAt_diff_self, continuousWithinAt_univ]
#align continuous_within_at_compl_self continuousWithinAt_compl_self
@[simp]
theorem continuousWithinAt_update_same [DecidableEq α] {f : α → β} {s : Set α} {x : α} {y : β} :
ContinuousWithinAt (update f x y) s x ↔ Tendsto f (𝓝[s \ {x}] x) (𝓝 y) :=
calc
ContinuousWithinAt (update f x y) s x ↔ Tendsto (update f x y) (𝓝[s \ {x}] x) (𝓝 y) := by
{ rw [← continuousWithinAt_diff_self, ContinuousWithinAt, update_same] }
_ ↔ Tendsto f (𝓝[s \ {x}] x) (𝓝 y) :=
tendsto_congr' <| eventually_nhdsWithin_iff.2 <| eventually_of_forall
fun z hz => update_noteq hz.2 _ _
#align continuous_within_at_update_same continuousWithinAt_update_same
@[simp]
theorem continuousAt_update_same [DecidableEq α] {f : α → β} {x : α} {y : β} :
ContinuousAt (Function.update f x y) x ↔ Tendsto f (𝓝[≠] x) (𝓝 y) := by
rw [← continuousWithinAt_univ, continuousWithinAt_update_same, compl_eq_univ_diff]
#align continuous_at_update_same continuousAt_update_same
theorem IsOpenMap.continuousOn_image_of_leftInvOn {f : α → β} {s : Set α}
(h : IsOpenMap (s.restrict f)) {finv : β → α} (hleft : LeftInvOn finv f s) :
ContinuousOn finv (f '' s) := by
refine continuousOn_iff'.2 fun t ht => ⟨f '' (t ∩ s), ?_, ?_⟩
· rw [← image_restrict]
exact h _ (ht.preimage continuous_subtype_val)
· rw [inter_eq_self_of_subset_left (image_subset f inter_subset_right), hleft.image_inter']
#align is_open_map.continuous_on_image_of_left_inv_on IsOpenMap.continuousOn_image_of_leftInvOn
theorem IsOpenMap.continuousOn_range_of_leftInverse {f : α → β} (hf : IsOpenMap f) {finv : β → α}
(hleft : Function.LeftInverse finv f) : ContinuousOn finv (range f) := by
rw [← image_univ]
exact (hf.restrict isOpen_univ).continuousOn_image_of_leftInvOn fun x _ => hleft x
#align is_open_map.continuous_on_range_of_left_inverse IsOpenMap.continuousOn_range_of_leftInverse
theorem ContinuousOn.congr_mono {f g : α → β} {s s₁ : Set α} (h : ContinuousOn f s)
(h' : EqOn g f s₁) (h₁ : s₁ ⊆ s) : ContinuousOn g s₁ := by
intro x hx
unfold ContinuousWithinAt
have A := (h x (h₁ hx)).mono h₁
unfold ContinuousWithinAt at A
rw [← h' hx] at A
exact A.congr' h'.eventuallyEq_nhdsWithin.symm
#align continuous_on.congr_mono ContinuousOn.congr_mono
theorem ContinuousOn.congr {f g : α → β} {s : Set α} (h : ContinuousOn f s) (h' : EqOn g f s) :
ContinuousOn g s :=
h.congr_mono h' (Subset.refl _)
#align continuous_on.congr ContinuousOn.congr
theorem continuousOn_congr {f g : α → β} {s : Set α} (h' : EqOn g f s) :
ContinuousOn g s ↔ ContinuousOn f s :=
⟨fun h => ContinuousOn.congr h h'.symm, fun h => h.congr h'⟩
#align continuous_on_congr continuousOn_congr
theorem ContinuousAt.continuousWithinAt {f : α → β} {s : Set α} {x : α} (h : ContinuousAt f x) :
ContinuousWithinAt f s x :=
ContinuousWithinAt.mono ((continuousWithinAt_univ f x).2 h) (subset_univ _)
#align continuous_at.continuous_within_at ContinuousAt.continuousWithinAt
theorem continuousWithinAt_iff_continuousAt {f : α → β} {s : Set α} {x : α} (h : s ∈ 𝓝 x) :
ContinuousWithinAt f s x ↔ ContinuousAt f x := by
rw [← univ_inter s, continuousWithinAt_inter h, continuousWithinAt_univ]
#align continuous_within_at_iff_continuous_at continuousWithinAt_iff_continuousAt
theorem ContinuousWithinAt.continuousAt {f : α → β} {s : Set α} {x : α}
(h : ContinuousWithinAt f s x) (hs : s ∈ 𝓝 x) : ContinuousAt f x :=
(continuousWithinAt_iff_continuousAt hs).mp h
#align continuous_within_at.continuous_at ContinuousWithinAt.continuousAt
theorem IsOpen.continuousOn_iff {f : α → β} {s : Set α} (hs : IsOpen s) :
ContinuousOn f s ↔ ∀ ⦃a⦄, a ∈ s → ContinuousAt f a :=
forall₂_congr fun _ => continuousWithinAt_iff_continuousAt ∘ hs.mem_nhds
#align is_open.continuous_on_iff IsOpen.continuousOn_iff
theorem ContinuousOn.continuousAt {f : α → β} {s : Set α} {x : α} (h : ContinuousOn f s)
(hx : s ∈ 𝓝 x) : ContinuousAt f x :=
(h x (mem_of_mem_nhds hx)).continuousAt hx
#align continuous_on.continuous_at ContinuousOn.continuousAt
theorem ContinuousAt.continuousOn {f : α → β} {s : Set α} (hcont : ∀ x ∈ s, ContinuousAt f x) :
ContinuousOn f s := fun x hx => (hcont x hx).continuousWithinAt
#align continuous_at.continuous_on ContinuousAt.continuousOn
theorem ContinuousWithinAt.comp {g : β → γ} {f : α → β} {s : Set α} {t : Set β} {x : α}
(hg : ContinuousWithinAt g t (f x)) (hf : ContinuousWithinAt f s x) (h : MapsTo f s t) :
ContinuousWithinAt (g ∘ f) s x :=
hg.tendsto.comp (hf.tendsto_nhdsWithin h)
#align continuous_within_at.comp ContinuousWithinAt.comp
theorem ContinuousWithinAt.comp' {g : β → γ} {f : α → β} {s : Set α} {t : Set β} {x : α}
(hg : ContinuousWithinAt g t (f x)) (hf : ContinuousWithinAt f s x) :
ContinuousWithinAt (g ∘ f) (s ∩ f ⁻¹' t) x :=
hg.comp (hf.mono inter_subset_left) inter_subset_right
#align continuous_within_at.comp' ContinuousWithinAt.comp'
theorem ContinuousAt.comp_continuousWithinAt {g : β → γ} {f : α → β} {s : Set α} {x : α}
(hg : ContinuousAt g (f x)) (hf : ContinuousWithinAt f s x) : ContinuousWithinAt (g ∘ f) s x :=
hg.continuousWithinAt.comp hf (mapsTo_univ _ _)
#align continuous_at.comp_continuous_within_at ContinuousAt.comp_continuousWithinAt
theorem ContinuousOn.comp {g : β → γ} {f : α → β} {s : Set α} {t : Set β} (hg : ContinuousOn g t)
(hf : ContinuousOn f s) (h : MapsTo f s t) : ContinuousOn (g ∘ f) s := fun x hx =>
ContinuousWithinAt.comp (hg _ (h hx)) (hf x hx) h
#align continuous_on.comp ContinuousOn.comp
@[fun_prop]
theorem ContinuousOn.comp'' {g : β → γ} {f : α → β} {s : Set α} {t : Set β} (hg : ContinuousOn g t)
(hf : ContinuousOn f s) (h : Set.MapsTo f s t) : ContinuousOn (fun x => g (f x)) s :=
ContinuousOn.comp hg hf h
theorem ContinuousOn.mono {f : α → β} {s t : Set α} (hf : ContinuousOn f s) (h : t ⊆ s) :
ContinuousOn f t := fun x hx => (hf x (h hx)).mono_left (nhdsWithin_mono _ h)
#align continuous_on.mono ContinuousOn.mono
theorem antitone_continuousOn {f : α → β} : Antitone (ContinuousOn f) := fun _s _t hst hf =>
hf.mono hst
#align antitone_continuous_on antitone_continuousOn
@[fun_prop]
theorem ContinuousOn.comp' {g : β → γ} {f : α → β} {s : Set α} {t : Set β} (hg : ContinuousOn g t)
(hf : ContinuousOn f s) : ContinuousOn (g ∘ f) (s ∩ f ⁻¹' t) :=
hg.comp (hf.mono inter_subset_left) inter_subset_right
#align continuous_on.comp' ContinuousOn.comp'
@[fun_prop]
theorem Continuous.continuousOn {f : α → β} {s : Set α} (h : Continuous f) : ContinuousOn f s := by
rw [continuous_iff_continuousOn_univ] at h
exact h.mono (subset_univ _)
#align continuous.continuous_on Continuous.continuousOn
theorem Continuous.continuousWithinAt {f : α → β} {s : Set α} {x : α} (h : Continuous f) :
ContinuousWithinAt f s x :=
h.continuousAt.continuousWithinAt
#align continuous.continuous_within_at Continuous.continuousWithinAt
theorem Continuous.comp_continuousOn {g : β → γ} {f : α → β} {s : Set α} (hg : Continuous g)
(hf : ContinuousOn f s) : ContinuousOn (g ∘ f) s :=
hg.continuousOn.comp hf (mapsTo_univ _ _)
#align continuous.comp_continuous_on Continuous.comp_continuousOn
@[fun_prop]
theorem Continuous.comp_continuousOn'
{α β γ : Type*} [TopologicalSpace α] [TopologicalSpace β] [TopologicalSpace γ] {g : β → γ}
{f : α → β} {s : Set α} (hg : Continuous g) (hf : ContinuousOn f s) :
ContinuousOn (fun x ↦ g (f x)) s :=
hg.comp_continuousOn hf
theorem ContinuousOn.comp_continuous {g : β → γ} {f : α → β} {s : Set β} (hg : ContinuousOn g s)
(hf : Continuous f) (hs : ∀ x, f x ∈ s) : Continuous (g ∘ f) := by
rw [continuous_iff_continuousOn_univ] at *
exact hg.comp hf fun x _ => hs x
#align continuous_on.comp_continuous ContinuousOn.comp_continuous
@[fun_prop]
theorem continuousOn_apply {ι : Type*} {π : ι → Type*} [∀ i, TopologicalSpace (π i)]
(i : ι) (s) : ContinuousOn (fun p : ∀ i, π i => p i) s :=
Continuous.continuousOn (continuous_apply i)
theorem ContinuousWithinAt.preimage_mem_nhdsWithin {f : α → β} {x : α} {s : Set α} {t : Set β}
(h : ContinuousWithinAt f s x) (ht : t ∈ 𝓝 (f x)) : f ⁻¹' t ∈ 𝓝[s] x :=
h ht
#align continuous_within_at.preimage_mem_nhds_within ContinuousWithinAt.preimage_mem_nhdsWithin
theorem Set.LeftInvOn.map_nhdsWithin_eq {f : α → β} {g : β → α} {x : β} {s : Set β}
(h : LeftInvOn f g s) (hx : f (g x) = x) (hf : ContinuousWithinAt f (g '' s) (g x))
(hg : ContinuousWithinAt g s x) : map g (𝓝[s] x) = 𝓝[g '' s] g x := by
apply le_antisymm
· exact hg.tendsto_nhdsWithin (mapsTo_image _ _)
· have A : g ∘ f =ᶠ[𝓝[g '' s] g x] id :=
h.rightInvOn_image.eqOn.eventuallyEq_of_mem self_mem_nhdsWithin
refine le_map_of_right_inverse A ?_
simpa only [hx] using hf.tendsto_nhdsWithin (h.mapsTo (surjOn_image _ _))
#align set.left_inv_on.map_nhds_within_eq Set.LeftInvOn.map_nhdsWithin_eq
theorem Function.LeftInverse.map_nhds_eq {f : α → β} {g : β → α} {x : β}
(h : Function.LeftInverse f g) (hf : ContinuousWithinAt f (range g) (g x))
(hg : ContinuousAt g x) : map g (𝓝 x) = 𝓝[range g] g x := by
simpa only [nhdsWithin_univ, image_univ] using
(h.leftInvOn univ).map_nhdsWithin_eq (h x) (by rwa [image_univ]) hg.continuousWithinAt
#align function.left_inverse.map_nhds_eq Function.LeftInverse.map_nhds_eq
theorem ContinuousWithinAt.preimage_mem_nhdsWithin' {f : α → β} {x : α} {s : Set α} {t : Set β}
(h : ContinuousWithinAt f s x) (ht : t ∈ 𝓝[f '' s] f x) : f ⁻¹' t ∈ 𝓝[s] x :=
h.tendsto_nhdsWithin (mapsTo_image _ _) ht
#align continuous_within_at.preimage_mem_nhds_within' ContinuousWithinAt.preimage_mem_nhdsWithin'
theorem ContinuousWithinAt.preimage_mem_nhdsWithin''
{f : α → β} {x : α} {y : β} {s t : Set β}
(h : ContinuousWithinAt f (f ⁻¹' s) x) (ht : t ∈ 𝓝[s] y) (hxy : y = f x) :
f ⁻¹' t ∈ 𝓝[f ⁻¹' s] x := by
rw [hxy] at ht
exact h.preimage_mem_nhdsWithin' (nhdsWithin_mono _ (image_preimage_subset f s) ht)
theorem Filter.EventuallyEq.congr_continuousWithinAt {f g : α → β} {s : Set α} {x : α}
(h : f =ᶠ[𝓝[s] x] g) (hx : f x = g x) :
ContinuousWithinAt f s x ↔ ContinuousWithinAt g s x := by
rw [ContinuousWithinAt, hx, tendsto_congr' h, ContinuousWithinAt]
#align filter.eventually_eq.congr_continuous_within_at Filter.EventuallyEq.congr_continuousWithinAt
theorem ContinuousWithinAt.congr_of_eventuallyEq {f f₁ : α → β} {s : Set α} {x : α}
(h : ContinuousWithinAt f s x) (h₁ : f₁ =ᶠ[𝓝[s] x] f) (hx : f₁ x = f x) :
ContinuousWithinAt f₁ s x :=
(h₁.congr_continuousWithinAt hx).2 h
#align continuous_within_at.congr_of_eventually_eq ContinuousWithinAt.congr_of_eventuallyEq
theorem ContinuousWithinAt.congr {f f₁ : α → β} {s : Set α} {x : α} (h : ContinuousWithinAt f s x)
(h₁ : ∀ y ∈ s, f₁ y = f y) (hx : f₁ x = f x) : ContinuousWithinAt f₁ s x :=
h.congr_of_eventuallyEq (mem_of_superset self_mem_nhdsWithin h₁) hx
#align continuous_within_at.congr ContinuousWithinAt.congr
theorem ContinuousWithinAt.congr_mono {f g : α → β} {s s₁ : Set α} {x : α}
(h : ContinuousWithinAt f s x) (h' : EqOn g f s₁) (h₁ : s₁ ⊆ s) (hx : g x = f x) :
ContinuousWithinAt g s₁ x :=
(h.mono h₁).congr h' hx
#align continuous_within_at.congr_mono ContinuousWithinAt.congr_mono
@[fun_prop]
theorem continuousOn_const {s : Set α} {c : β} : ContinuousOn (fun _ => c) s :=
continuous_const.continuousOn
#align continuous_on_const continuousOn_const
theorem continuousWithinAt_const {b : β} {s : Set α} {x : α} :
ContinuousWithinAt (fun _ : α => b) s x :=
continuous_const.continuousWithinAt
#align continuous_within_at_const continuousWithinAt_const
theorem continuousOn_id {s : Set α} : ContinuousOn id s :=
continuous_id.continuousOn
#align continuous_on_id continuousOn_id
@[fun_prop]
theorem continuousOn_id' (s : Set α) : ContinuousOn (fun x : α => x) s := continuousOn_id
theorem continuousWithinAt_id {s : Set α} {x : α} : ContinuousWithinAt id s x :=
continuous_id.continuousWithinAt
#align continuous_within_at_id continuousWithinAt_id
theorem continuousOn_open_iff {f : α → β} {s : Set α} (hs : IsOpen s) :
ContinuousOn f s ↔ ∀ t, IsOpen t → IsOpen (s ∩ f ⁻¹' t) := by
rw [continuousOn_iff']
constructor
· intro h t ht
rcases h t ht with ⟨u, u_open, hu⟩
rw [inter_comm, hu]
apply IsOpen.inter u_open hs
· intro h t ht
refine ⟨s ∩ f ⁻¹' t, h t ht, ?_⟩
rw [@inter_comm _ s (f ⁻¹' t), inter_assoc, inter_self]
#align continuous_on_open_iff continuousOn_open_iff
theorem ContinuousOn.isOpen_inter_preimage {f : α → β} {s : Set α} {t : Set β}
(hf : ContinuousOn f s) (hs : IsOpen s) (ht : IsOpen t) : IsOpen (s ∩ f ⁻¹' t) :=
(continuousOn_open_iff hs).1 hf t ht
#align continuous_on.preimage_open_of_open ContinuousOn.isOpen_inter_preimage
| Mathlib/Topology/ContinuousOn.lean | 1,088 | 1,091 | theorem ContinuousOn.isOpen_preimage {f : α → β} {s : Set α} {t : Set β} (h : ContinuousOn f s)
(hs : IsOpen s) (hp : f ⁻¹' t ⊆ s) (ht : IsOpen t) : IsOpen (f ⁻¹' t) := by |
convert (continuousOn_open_iff hs).mp h t ht
rw [inter_comm, inter_eq_self_of_subset_left hp]
|
import Mathlib.Algebra.MonoidAlgebra.Degree
import Mathlib.Algebra.Polynomial.Coeff
import Mathlib.Algebra.Polynomial.Monomial
import Mathlib.Data.Fintype.BigOperators
import Mathlib.Data.Nat.WithBot
import Mathlib.Data.Nat.Cast.WithTop
import Mathlib.Data.Nat.SuccPred
#align_import data.polynomial.degree.definitions from "leanprover-community/mathlib"@"808ea4ebfabeb599f21ec4ae87d6dc969597887f"
-- Porting note: `Mathlib.Data.Nat.Cast.WithTop` should be imported for `Nat.cast_withBot`.
set_option linter.uppercaseLean3 false
noncomputable section
open Finsupp Finset
open Polynomial
namespace Polynomial
universe u v
variable {R : Type u} {S : Type v} {a b c d : R} {n m : ℕ}
section Semiring
variable [Semiring R] {p q r : R[X]}
def degree (p : R[X]) : WithBot ℕ :=
p.support.max
#align polynomial.degree Polynomial.degree
theorem supDegree_eq_degree (p : R[X]) : p.toFinsupp.supDegree WithBot.some = p.degree :=
max_eq_sup_coe
theorem degree_lt_wf : WellFounded fun p q : R[X] => degree p < degree q :=
InvImage.wf degree wellFounded_lt
#align polynomial.degree_lt_wf Polynomial.degree_lt_wf
instance : WellFoundedRelation R[X] :=
⟨_, degree_lt_wf⟩
def natDegree (p : R[X]) : ℕ :=
(degree p).unbot' 0
#align polynomial.nat_degree Polynomial.natDegree
def leadingCoeff (p : R[X]) : R :=
coeff p (natDegree p)
#align polynomial.leading_coeff Polynomial.leadingCoeff
def Monic (p : R[X]) :=
leadingCoeff p = (1 : R)
#align polynomial.monic Polynomial.Monic
@[nontriviality]
theorem monic_of_subsingleton [Subsingleton R] (p : R[X]) : Monic p :=
Subsingleton.elim _ _
#align polynomial.monic_of_subsingleton Polynomial.monic_of_subsingleton
theorem Monic.def : Monic p ↔ leadingCoeff p = 1 :=
Iff.rfl
#align polynomial.monic.def Polynomial.Monic.def
instance Monic.decidable [DecidableEq R] : Decidable (Monic p) := by unfold Monic; infer_instance
#align polynomial.monic.decidable Polynomial.Monic.decidable
@[simp]
theorem Monic.leadingCoeff {p : R[X]} (hp : p.Monic) : leadingCoeff p = 1 :=
hp
#align polynomial.monic.leading_coeff Polynomial.Monic.leadingCoeff
theorem Monic.coeff_natDegree {p : R[X]} (hp : p.Monic) : p.coeff p.natDegree = 1 :=
hp
#align polynomial.monic.coeff_nat_degree Polynomial.Monic.coeff_natDegree
@[simp]
theorem degree_zero : degree (0 : R[X]) = ⊥ :=
rfl
#align polynomial.degree_zero Polynomial.degree_zero
@[simp]
theorem natDegree_zero : natDegree (0 : R[X]) = 0 :=
rfl
#align polynomial.nat_degree_zero Polynomial.natDegree_zero
@[simp]
theorem coeff_natDegree : coeff p (natDegree p) = leadingCoeff p :=
rfl
#align polynomial.coeff_nat_degree Polynomial.coeff_natDegree
@[simp]
theorem degree_eq_bot : degree p = ⊥ ↔ p = 0 :=
⟨fun h => support_eq_empty.1 (Finset.max_eq_bot.1 h), fun h => h.symm ▸ rfl⟩
#align polynomial.degree_eq_bot Polynomial.degree_eq_bot
@[nontriviality]
theorem degree_of_subsingleton [Subsingleton R] : degree p = ⊥ := by
rw [Subsingleton.elim p 0, degree_zero]
#align polynomial.degree_of_subsingleton Polynomial.degree_of_subsingleton
@[nontriviality]
theorem natDegree_of_subsingleton [Subsingleton R] : natDegree p = 0 := by
rw [Subsingleton.elim p 0, natDegree_zero]
#align polynomial.nat_degree_of_subsingleton Polynomial.natDegree_of_subsingleton
theorem degree_eq_natDegree (hp : p ≠ 0) : degree p = (natDegree p : WithBot ℕ) := by
let ⟨n, hn⟩ := not_forall.1 (mt Option.eq_none_iff_forall_not_mem.2 (mt degree_eq_bot.1 hp))
have hn : degree p = some n := Classical.not_not.1 hn
rw [natDegree, hn]; rfl
#align polynomial.degree_eq_nat_degree Polynomial.degree_eq_natDegree
theorem supDegree_eq_natDegree (p : R[X]) : p.toFinsupp.supDegree id = p.natDegree := by
obtain rfl|h := eq_or_ne p 0
· simp
apply WithBot.coe_injective
rw [← AddMonoidAlgebra.supDegree_withBot_some_comp, Function.comp_id, supDegree_eq_degree,
degree_eq_natDegree h, Nat.cast_withBot]
rwa [support_toFinsupp, nonempty_iff_ne_empty, Ne, support_eq_empty]
theorem degree_eq_iff_natDegree_eq {p : R[X]} {n : ℕ} (hp : p ≠ 0) :
p.degree = n ↔ p.natDegree = n := by rw [degree_eq_natDegree hp]; exact WithBot.coe_eq_coe
#align polynomial.degree_eq_iff_nat_degree_eq Polynomial.degree_eq_iff_natDegree_eq
theorem degree_eq_iff_natDegree_eq_of_pos {p : R[X]} {n : ℕ} (hn : 0 < n) :
p.degree = n ↔ p.natDegree = n := by
obtain rfl|h := eq_or_ne p 0
· simp [hn.ne]
· exact degree_eq_iff_natDegree_eq h
#align polynomial.degree_eq_iff_nat_degree_eq_of_pos Polynomial.degree_eq_iff_natDegree_eq_of_pos
theorem natDegree_eq_of_degree_eq_some {p : R[X]} {n : ℕ} (h : degree p = n) : natDegree p = n := by
-- Porting note: `Nat.cast_withBot` is required.
rw [natDegree, h, Nat.cast_withBot, WithBot.unbot'_coe]
#align polynomial.nat_degree_eq_of_degree_eq_some Polynomial.natDegree_eq_of_degree_eq_some
theorem degree_ne_of_natDegree_ne {n : ℕ} : p.natDegree ≠ n → degree p ≠ n :=
mt natDegree_eq_of_degree_eq_some
#align polynomial.degree_ne_of_nat_degree_ne Polynomial.degree_ne_of_natDegree_ne
@[simp]
theorem degree_le_natDegree : degree p ≤ natDegree p :=
WithBot.giUnbot'Bot.gc.le_u_l _
#align polynomial.degree_le_nat_degree Polynomial.degree_le_natDegree
theorem natDegree_eq_of_degree_eq [Semiring S] {q : S[X]} (h : degree p = degree q) :
natDegree p = natDegree q := by unfold natDegree; rw [h]
#align polynomial.nat_degree_eq_of_degree_eq Polynomial.natDegree_eq_of_degree_eq
theorem le_degree_of_ne_zero (h : coeff p n ≠ 0) : (n : WithBot ℕ) ≤ degree p := by
rw [Nat.cast_withBot]
exact Finset.le_sup (mem_support_iff.2 h)
#align polynomial.le_degree_of_ne_zero Polynomial.le_degree_of_ne_zero
theorem le_natDegree_of_ne_zero (h : coeff p n ≠ 0) : n ≤ natDegree p := by
rw [← Nat.cast_le (α := WithBot ℕ), ← degree_eq_natDegree]
· exact le_degree_of_ne_zero h
· rintro rfl
exact h rfl
#align polynomial.le_nat_degree_of_ne_zero Polynomial.le_natDegree_of_ne_zero
theorem le_natDegree_of_mem_supp (a : ℕ) : a ∈ p.support → a ≤ natDegree p :=
le_natDegree_of_ne_zero ∘ mem_support_iff.mp
#align polynomial.le_nat_degree_of_mem_supp Polynomial.le_natDegree_of_mem_supp
theorem degree_eq_of_le_of_coeff_ne_zero (pn : p.degree ≤ n) (p1 : p.coeff n ≠ 0) : p.degree = n :=
pn.antisymm (le_degree_of_ne_zero p1)
#align polynomial.degree_eq_of_le_of_coeff_ne_zero Polynomial.degree_eq_of_le_of_coeff_ne_zero
theorem natDegree_eq_of_le_of_coeff_ne_zero (pn : p.natDegree ≤ n) (p1 : p.coeff n ≠ 0) :
p.natDegree = n :=
pn.antisymm (le_natDegree_of_ne_zero p1)
#align polynomial.nat_degree_eq_of_le_of_coeff_ne_zero Polynomial.natDegree_eq_of_le_of_coeff_ne_zero
theorem degree_mono [Semiring S] {f : R[X]} {g : S[X]} (h : f.support ⊆ g.support) :
f.degree ≤ g.degree :=
Finset.sup_mono h
#align polynomial.degree_mono Polynomial.degree_mono
theorem supp_subset_range (h : natDegree p < m) : p.support ⊆ Finset.range m := fun _n hn =>
mem_range.2 <| (le_natDegree_of_mem_supp _ hn).trans_lt h
#align polynomial.supp_subset_range Polynomial.supp_subset_range
theorem supp_subset_range_natDegree_succ : p.support ⊆ Finset.range (natDegree p + 1) :=
supp_subset_range (Nat.lt_succ_self _)
#align polynomial.supp_subset_range_nat_degree_succ Polynomial.supp_subset_range_natDegree_succ
theorem degree_le_degree (h : coeff q (natDegree p) ≠ 0) : degree p ≤ degree q := by
by_cases hp : p = 0
· rw [hp, degree_zero]
exact bot_le
· rw [degree_eq_natDegree hp]
exact le_degree_of_ne_zero h
#align polynomial.degree_le_degree Polynomial.degree_le_degree
theorem natDegree_le_iff_degree_le {n : ℕ} : natDegree p ≤ n ↔ degree p ≤ n :=
WithBot.unbot'_le_iff (fun _ ↦ bot_le)
#align polynomial.nat_degree_le_iff_degree_le Polynomial.natDegree_le_iff_degree_le
theorem natDegree_lt_iff_degree_lt (hp : p ≠ 0) : p.natDegree < n ↔ p.degree < ↑n :=
WithBot.unbot'_lt_iff (absurd · (degree_eq_bot.not.mpr hp))
#align polynomial.nat_degree_lt_iff_degree_lt Polynomial.natDegree_lt_iff_degree_lt
alias ⟨degree_le_of_natDegree_le, natDegree_le_of_degree_le⟩ := natDegree_le_iff_degree_le
#align polynomial.degree_le_of_nat_degree_le Polynomial.degree_le_of_natDegree_le
#align polynomial.nat_degree_le_of_degree_le Polynomial.natDegree_le_of_degree_le
theorem natDegree_le_natDegree [Semiring S] {q : S[X]} (hpq : p.degree ≤ q.degree) :
p.natDegree ≤ q.natDegree :=
WithBot.giUnbot'Bot.gc.monotone_l hpq
#align polynomial.nat_degree_le_nat_degree Polynomial.natDegree_le_natDegree
theorem natDegree_lt_natDegree {p q : R[X]} (hp : p ≠ 0) (hpq : p.degree < q.degree) :
p.natDegree < q.natDegree := by
by_cases hq : q = 0
· exact (not_lt_bot <| hq ▸ hpq).elim
rwa [degree_eq_natDegree hp, degree_eq_natDegree hq, Nat.cast_lt] at hpq
#align polynomial.nat_degree_lt_nat_degree Polynomial.natDegree_lt_natDegree
@[simp]
theorem degree_C (ha : a ≠ 0) : degree (C a) = (0 : WithBot ℕ) := by
rw [degree, ← monomial_zero_left, support_monomial 0 ha, max_eq_sup_coe, sup_singleton,
WithBot.coe_zero]
#align polynomial.degree_C Polynomial.degree_C
theorem degree_C_le : degree (C a) ≤ 0 := by
by_cases h : a = 0
· rw [h, C_0]
exact bot_le
· rw [degree_C h]
#align polynomial.degree_C_le Polynomial.degree_C_le
theorem degree_C_lt : degree (C a) < 1 :=
degree_C_le.trans_lt <| WithBot.coe_lt_coe.mpr zero_lt_one
#align polynomial.degree_C_lt Polynomial.degree_C_lt
theorem degree_one_le : degree (1 : R[X]) ≤ (0 : WithBot ℕ) := by rw [← C_1]; exact degree_C_le
#align polynomial.degree_one_le Polynomial.degree_one_le
@[simp]
theorem natDegree_C (a : R) : natDegree (C a) = 0 := by
by_cases ha : a = 0
· have : C a = 0 := by rw [ha, C_0]
rw [natDegree, degree_eq_bot.2 this, WithBot.unbot'_bot]
· rw [natDegree, degree_C ha, WithBot.unbot_zero']
#align polynomial.nat_degree_C Polynomial.natDegree_C
@[simp]
theorem natDegree_one : natDegree (1 : R[X]) = 0 :=
natDegree_C 1
#align polynomial.nat_degree_one Polynomial.natDegree_one
@[simp]
theorem natDegree_natCast (n : ℕ) : natDegree (n : R[X]) = 0 := by
simp only [← C_eq_natCast, natDegree_C]
#align polynomial.nat_degree_nat_cast Polynomial.natDegree_natCast
@[deprecated (since := "2024-04-17")]
alias natDegree_nat_cast := natDegree_natCast
theorem degree_natCast_le (n : ℕ) : degree (n : R[X]) ≤ 0 := degree_le_of_natDegree_le (by simp)
@[deprecated (since := "2024-04-17")]
alias degree_nat_cast_le := degree_natCast_le
@[simp]
theorem degree_monomial (n : ℕ) (ha : a ≠ 0) : degree (monomial n a) = n := by
rw [degree, support_monomial n ha, max_singleton, Nat.cast_withBot]
#align polynomial.degree_monomial Polynomial.degree_monomial
@[simp]
| Mathlib/Algebra/Polynomial/Degree/Definitions.lean | 297 | 298 | theorem degree_C_mul_X_pow (n : ℕ) (ha : a ≠ 0) : degree (C a * X ^ n) = n := by |
rw [C_mul_X_pow_eq_monomial, degree_monomial n ha]
|
import Mathlib.NumberTheory.Zsqrtd.Basic
import Mathlib.RingTheory.PrincipalIdealDomain
import Mathlib.Data.Complex.Basic
import Mathlib.Data.Real.Archimedean
#align_import number_theory.zsqrtd.gaussian_int from "leanprover-community/mathlib"@"5b2fe80501ff327b9109fb09b7cc8c325cd0d7d9"
open Zsqrtd Complex
open scoped ComplexConjugate
abbrev GaussianInt : Type :=
Zsqrtd (-1)
#align gaussian_int GaussianInt
local notation "ℤ[i]" => GaussianInt
namespace GaussianInt
instance : Repr ℤ[i] :=
⟨fun x _ => "⟨" ++ repr x.re ++ ", " ++ repr x.im ++ "⟩"⟩
instance instCommRing : CommRing ℤ[i] :=
Zsqrtd.commRing
#align gaussian_int.comm_ring GaussianInt.instCommRing
section
attribute [-instance] Complex.instField -- Avoid making things noncomputable unnecessarily.
def toComplex : ℤ[i] →+* ℂ :=
Zsqrtd.lift ⟨I, by simp⟩
#align gaussian_int.to_complex GaussianInt.toComplex
end
instance : Coe ℤ[i] ℂ :=
⟨toComplex⟩
theorem toComplex_def (x : ℤ[i]) : (x : ℂ) = x.re + x.im * I :=
rfl
#align gaussian_int.to_complex_def GaussianInt.toComplex_def
theorem toComplex_def' (x y : ℤ) : ((⟨x, y⟩ : ℤ[i]) : ℂ) = x + y * I := by simp [toComplex_def]
#align gaussian_int.to_complex_def' GaussianInt.toComplex_def'
theorem toComplex_def₂ (x : ℤ[i]) : (x : ℂ) = ⟨x.re, x.im⟩ := by
apply Complex.ext <;> simp [toComplex_def]
#align gaussian_int.to_complex_def₂ GaussianInt.toComplex_def₂
@[simp]
theorem to_real_re (x : ℤ[i]) : ((x.re : ℤ) : ℝ) = (x : ℂ).re := by simp [toComplex_def]
#align gaussian_int.to_real_re GaussianInt.to_real_re
@[simp]
theorem to_real_im (x : ℤ[i]) : ((x.im : ℤ) : ℝ) = (x : ℂ).im := by simp [toComplex_def]
#align gaussian_int.to_real_im GaussianInt.to_real_im
@[simp]
theorem toComplex_re (x y : ℤ) : ((⟨x, y⟩ : ℤ[i]) : ℂ).re = x := by simp [toComplex_def]
#align gaussian_int.to_complex_re GaussianInt.toComplex_re
@[simp]
theorem toComplex_im (x y : ℤ) : ((⟨x, y⟩ : ℤ[i]) : ℂ).im = y := by simp [toComplex_def]
#align gaussian_int.to_complex_im GaussianInt.toComplex_im
-- Porting note (#10618): @[simp] can prove this
theorem toComplex_add (x y : ℤ[i]) : ((x + y : ℤ[i]) : ℂ) = x + y :=
toComplex.map_add _ _
#align gaussian_int.to_complex_add GaussianInt.toComplex_add
-- Porting note (#10618): @[simp] can prove this
theorem toComplex_mul (x y : ℤ[i]) : ((x * y : ℤ[i]) : ℂ) = x * y :=
toComplex.map_mul _ _
#align gaussian_int.to_complex_mul GaussianInt.toComplex_mul
-- Porting note (#10618): @[simp] can prove this
theorem toComplex_one : ((1 : ℤ[i]) : ℂ) = 1 :=
toComplex.map_one
#align gaussian_int.to_complex_one GaussianInt.toComplex_one
-- Porting note (#10618): @[simp] can prove this
theorem toComplex_zero : ((0 : ℤ[i]) : ℂ) = 0 :=
toComplex.map_zero
#align gaussian_int.to_complex_zero GaussianInt.toComplex_zero
-- Porting note (#10618): @[simp] can prove this
theorem toComplex_neg (x : ℤ[i]) : ((-x : ℤ[i]) : ℂ) = -x :=
toComplex.map_neg _
#align gaussian_int.to_complex_neg GaussianInt.toComplex_neg
-- Porting note (#10618): @[simp] can prove this
theorem toComplex_sub (x y : ℤ[i]) : ((x - y : ℤ[i]) : ℂ) = x - y :=
toComplex.map_sub _ _
#align gaussian_int.to_complex_sub GaussianInt.toComplex_sub
@[simp]
theorem toComplex_star (x : ℤ[i]) : ((star x : ℤ[i]) : ℂ) = conj (x : ℂ) := by
rw [toComplex_def₂, toComplex_def₂]
exact congr_arg₂ _ rfl (Int.cast_neg _)
#align gaussian_int.to_complex_star GaussianInt.toComplex_star
@[simp]
theorem toComplex_inj {x y : ℤ[i]} : (x : ℂ) = y ↔ x = y := by
cases x; cases y; simp [toComplex_def₂]
#align gaussian_int.to_complex_inj GaussianInt.toComplex_inj
lemma toComplex_injective : Function.Injective GaussianInt.toComplex :=
fun ⦃_ _⦄ ↦ toComplex_inj.mp
@[simp]
theorem toComplex_eq_zero {x : ℤ[i]} : (x : ℂ) = 0 ↔ x = 0 := by
rw [← toComplex_zero, toComplex_inj]
#align gaussian_int.to_complex_eq_zero GaussianInt.toComplex_eq_zero
@[simp]
theorem intCast_real_norm (x : ℤ[i]) : (x.norm : ℝ) = Complex.normSq (x : ℂ) := by
rw [Zsqrtd.norm, normSq]; simp
#align gaussian_int.nat_cast_real_norm GaussianInt.intCast_real_norm
@[deprecated (since := "2024-04-17")]
alias int_cast_real_norm := intCast_real_norm
@[simp]
theorem intCast_complex_norm (x : ℤ[i]) : (x.norm : ℂ) = Complex.normSq (x : ℂ) := by
cases x; rw [Zsqrtd.norm, normSq]; simp
#align gaussian_int.nat_cast_complex_norm GaussianInt.intCast_complex_norm
@[deprecated (since := "2024-04-17")]
alias int_cast_complex_norm := intCast_complex_norm
theorem norm_nonneg (x : ℤ[i]) : 0 ≤ norm x :=
Zsqrtd.norm_nonneg (by norm_num) _
#align gaussian_int.norm_nonneg GaussianInt.norm_nonneg
@[simp]
theorem norm_eq_zero {x : ℤ[i]} : norm x = 0 ↔ x = 0 := by rw [← @Int.cast_inj ℝ _ _ _]; simp
#align gaussian_int.norm_eq_zero GaussianInt.norm_eq_zero
theorem norm_pos {x : ℤ[i]} : 0 < norm x ↔ x ≠ 0 := by
rw [lt_iff_le_and_ne, Ne, eq_comm, norm_eq_zero]; simp [norm_nonneg]
#align gaussian_int.norm_pos GaussianInt.norm_pos
theorem abs_natCast_norm (x : ℤ[i]) : (x.norm.natAbs : ℤ) = x.norm :=
Int.natAbs_of_nonneg (norm_nonneg _)
#align gaussian_int.abs_coe_nat_norm GaussianInt.abs_natCast_norm
-- 2024-04-05
@[deprecated] alias abs_coe_nat_norm := abs_natCast_norm
@[simp]
theorem natCast_natAbs_norm {α : Type*} [Ring α] (x : ℤ[i]) : (x.norm.natAbs : α) = x.norm := by
rw [← Int.cast_natCast, abs_natCast_norm]
#align gaussian_int.nat_cast_nat_abs_norm GaussianInt.natCast_natAbs_norm
@[deprecated (since := "2024-04-17")]
alias nat_cast_natAbs_norm := natCast_natAbs_norm
theorem natAbs_norm_eq (x : ℤ[i]) :
x.norm.natAbs = x.re.natAbs * x.re.natAbs + x.im.natAbs * x.im.natAbs :=
Int.ofNat.inj <| by simp; simp [Zsqrtd.norm]
#align gaussian_int.nat_abs_norm_eq GaussianInt.natAbs_norm_eq
instance : Div ℤ[i] :=
⟨fun x y =>
let n := (norm y : ℚ)⁻¹
let c := star y
⟨round ((x * c).re * n : ℚ), round ((x * c).im * n : ℚ)⟩⟩
theorem div_def (x y : ℤ[i]) :
x / y = ⟨round ((x * star y).re / norm y : ℚ), round ((x * star y).im / norm y : ℚ)⟩ :=
show Zsqrtd.mk _ _ = _ by simp [div_eq_mul_inv]
#align gaussian_int.div_def GaussianInt.div_def
theorem toComplex_div_re (x y : ℤ[i]) : ((x / y : ℤ[i]) : ℂ).re = round (x / y : ℂ).re := by
rw [div_def, ← @Rat.round_cast ℝ _ _]
simp [-Rat.round_cast, mul_assoc, div_eq_mul_inv, mul_add, add_mul]
#align gaussian_int.to_complex_div_re GaussianInt.toComplex_div_re
theorem toComplex_div_im (x y : ℤ[i]) : ((x / y : ℤ[i]) : ℂ).im = round (x / y : ℂ).im := by
rw [div_def, ← @Rat.round_cast ℝ _ _, ← @Rat.round_cast ℝ _ _]
simp [-Rat.round_cast, mul_assoc, div_eq_mul_inv, mul_add, add_mul]
#align gaussian_int.to_complex_div_im GaussianInt.toComplex_div_im
| Mathlib/NumberTheory/Zsqrtd/GaussianInt.lean | 222 | 228 | theorem normSq_le_normSq_of_re_le_of_im_le {x y : ℂ} (hre : |x.re| ≤ |y.re|)
(him : |x.im| ≤ |y.im|) : Complex.normSq x ≤ Complex.normSq y := by |
rw [normSq_apply, normSq_apply, ← _root_.abs_mul_self, _root_.abs_mul, ←
_root_.abs_mul_self y.re, _root_.abs_mul y.re, ← _root_.abs_mul_self x.im,
_root_.abs_mul x.im, ← _root_.abs_mul_self y.im, _root_.abs_mul y.im]
exact
add_le_add (mul_self_le_mul_self (abs_nonneg _) hre) (mul_self_le_mul_self (abs_nonneg _) him)
|
import Mathlib.Dynamics.Ergodic.MeasurePreserving
import Mathlib.LinearAlgebra.Determinant
import Mathlib.LinearAlgebra.Matrix.Diagonal
import Mathlib.LinearAlgebra.Matrix.Transvection
import Mathlib.MeasureTheory.Group.LIntegral
import Mathlib.MeasureTheory.Integral.Marginal
import Mathlib.MeasureTheory.Measure.Stieltjes
import Mathlib.MeasureTheory.Measure.Haar.OfBasis
#align_import measure_theory.measure.lebesgue.basic from "leanprover-community/mathlib"@"fd5edc43dc4f10b85abfe544b88f82cf13c5f844"
assert_not_exists MeasureTheory.integral
noncomputable section
open scoped Classical
open Set Filter MeasureTheory MeasureTheory.Measure TopologicalSpace
open ENNReal (ofReal)
open scoped ENNReal NNReal Topology
namespace Real
variable {ι : Type*} [Fintype ι]
theorem volume_eq_stieltjes_id : (volume : Measure ℝ) = StieltjesFunction.id.measure := by
haveI : IsAddLeftInvariant StieltjesFunction.id.measure :=
⟨fun a =>
Eq.symm <|
Real.measure_ext_Ioo_rat fun p q => by
simp only [Measure.map_apply (measurable_const_add a) measurableSet_Ioo,
sub_sub_sub_cancel_right, StieltjesFunction.measure_Ioo, StieltjesFunction.id_leftLim,
StieltjesFunction.id_apply, id, preimage_const_add_Ioo]⟩
have A : StieltjesFunction.id.measure (stdOrthonormalBasis ℝ ℝ).toBasis.parallelepiped = 1 := by
change StieltjesFunction.id.measure (parallelepiped (stdOrthonormalBasis ℝ ℝ)) = 1
rcases parallelepiped_orthonormalBasis_one_dim (stdOrthonormalBasis ℝ ℝ) with (H | H) <;>
simp only [H, StieltjesFunction.measure_Icc, StieltjesFunction.id_apply, id, tsub_zero,
StieltjesFunction.id_leftLim, sub_neg_eq_add, zero_add, ENNReal.ofReal_one]
conv_rhs =>
rw [addHaarMeasure_unique StieltjesFunction.id.measure
(stdOrthonormalBasis ℝ ℝ).toBasis.parallelepiped, A]
simp only [volume, Basis.addHaar, one_smul]
#align real.volume_eq_stieltjes_id Real.volume_eq_stieltjes_id
theorem volume_val (s) : volume s = StieltjesFunction.id.measure s := by
simp [volume_eq_stieltjes_id]
#align real.volume_val Real.volume_val
@[simp]
theorem volume_Ico {a b : ℝ} : volume (Ico a b) = ofReal (b - a) := by simp [volume_val]
#align real.volume_Ico Real.volume_Ico
@[simp]
theorem volume_Icc {a b : ℝ} : volume (Icc a b) = ofReal (b - a) := by simp [volume_val]
#align real.volume_Icc Real.volume_Icc
@[simp]
theorem volume_Ioo {a b : ℝ} : volume (Ioo a b) = ofReal (b - a) := by simp [volume_val]
#align real.volume_Ioo Real.volume_Ioo
@[simp]
theorem volume_Ioc {a b : ℝ} : volume (Ioc a b) = ofReal (b - a) := by simp [volume_val]
#align real.volume_Ioc Real.volume_Ioc
-- @[simp] -- Porting note (#10618): simp can prove this
theorem volume_singleton {a : ℝ} : volume ({a} : Set ℝ) = 0 := by simp [volume_val]
#align real.volume_singleton Real.volume_singleton
-- @[simp] -- Porting note (#10618): simp can prove this, after mathlib4#4628
| Mathlib/MeasureTheory/Measure/Lebesgue/Basic.lean | 100 | 104 | theorem volume_univ : volume (univ : Set ℝ) = ∞ :=
ENNReal.eq_top_of_forall_nnreal_le fun r =>
calc
(r : ℝ≥0∞) = volume (Icc (0 : ℝ) r) := by | simp
_ ≤ volume univ := measure_mono (subset_univ _)
|
import Mathlib.Data.Matrix.Basic
import Mathlib.LinearAlgebra.Matrix.Trace
#align_import data.matrix.basis from "leanprover-community/mathlib"@"320df450e9abeb5fc6417971e75acb6ae8bc3794"
variable {l m n : Type*}
variable {R α : Type*}
namespace Matrix
open Matrix
variable [DecidableEq l] [DecidableEq m] [DecidableEq n]
variable [Semiring α]
def stdBasisMatrix (i : m) (j : n) (a : α) : Matrix m n α := fun i' j' =>
if i = i' ∧ j = j' then a else 0
#align matrix.std_basis_matrix Matrix.stdBasisMatrix
@[simp]
theorem smul_stdBasisMatrix [SMulZeroClass R α] (r : R) (i : m) (j : n) (a : α) :
r • stdBasisMatrix i j a = stdBasisMatrix i j (r • a) := by
unfold stdBasisMatrix
ext
simp [smul_ite]
#align matrix.smul_std_basis_matrix Matrix.smul_stdBasisMatrix
@[simp]
theorem stdBasisMatrix_zero (i : m) (j : n) : stdBasisMatrix i j (0 : α) = 0 := by
unfold stdBasisMatrix
ext
simp
#align matrix.std_basis_matrix_zero Matrix.stdBasisMatrix_zero
theorem stdBasisMatrix_add (i : m) (j : n) (a b : α) :
stdBasisMatrix i j (a + b) = stdBasisMatrix i j a + stdBasisMatrix i j b := by
unfold stdBasisMatrix; ext
split_ifs with h <;> simp [h]
#align matrix.std_basis_matrix_add Matrix.stdBasisMatrix_add
theorem mulVec_stdBasisMatrix [Fintype m] (i : n) (j : m) (c : α) (x : m → α) :
mulVec (stdBasisMatrix i j c) x = Function.update (0 : n → α) i (c * x j) := by
ext i'
simp [stdBasisMatrix, mulVec, dotProduct]
rcases eq_or_ne i i' with rfl|h
· simp
simp [h, h.symm]
theorem matrix_eq_sum_std_basis [Fintype m] [Fintype n] (x : Matrix m n α) :
x = ∑ i : m, ∑ j : n, stdBasisMatrix i j (x i j) := by
ext i j; symm
iterate 2 rw [Finset.sum_apply]
-- Porting note: was `convert`
refine (Fintype.sum_eq_single i ?_).trans ?_; swap
· -- Porting note: `simp` seems unwilling to apply `Fintype.sum_apply`
simp (config := { unfoldPartialApp := true }) only [stdBasisMatrix]
rw [Fintype.sum_apply, Fintype.sum_apply]
simp
· intro j' hj'
-- Porting note: `simp` seems unwilling to apply `Fintype.sum_apply`
simp (config := { unfoldPartialApp := true }) only [stdBasisMatrix]
rw [Fintype.sum_apply, Fintype.sum_apply]
simp [hj']
#align matrix.matrix_eq_sum_std_basis Matrix.matrix_eq_sum_std_basis
-- TODO: tie this up with the `Basis` machinery of linear algebra
-- this is not completely trivial because we are indexing by two types, instead of one
-- TODO: add `std_basis_vec`
theorem std_basis_eq_basis_mul_basis (i : m) (j : n) :
stdBasisMatrix i j (1 : α) =
vecMulVec (fun i' => ite (i = i') 1 0) fun j' => ite (j = j') 1 0 := by
ext i' j'
-- Porting note: was `norm_num [std_basis_matrix, vec_mul_vec]` though there are no numerals
-- involved.
simp only [stdBasisMatrix, vecMulVec, mul_ite, mul_one, mul_zero, of_apply]
-- Porting note: added next line
simp_rw [@and_comm (i = i')]
exact ite_and _ _ _ _
#align matrix.std_basis_eq_basis_mul_basis Matrix.std_basis_eq_basis_mul_basis
-- todo: the old proof used fintypes, I don't know `Finsupp` but this feels generalizable
@[elab_as_elim]
protected theorem induction_on' [Finite m] [Finite n] {P : Matrix m n α → Prop} (M : Matrix m n α)
(h_zero : P 0) (h_add : ∀ p q, P p → P q → P (p + q))
(h_std_basis : ∀ (i : m) (j : n) (x : α), P (stdBasisMatrix i j x)) : P M := by
cases nonempty_fintype m; cases nonempty_fintype n
rw [matrix_eq_sum_std_basis M, ← Finset.sum_product']
apply Finset.sum_induction _ _ h_add h_zero
· intros
apply h_std_basis
#align matrix.induction_on' Matrix.induction_on'
@[elab_as_elim]
protected theorem induction_on [Finite m] [Finite n] [Nonempty m] [Nonempty n]
{P : Matrix m n α → Prop} (M : Matrix m n α) (h_add : ∀ p q, P p → P q → P (p + q))
(h_std_basis : ∀ i j x, P (stdBasisMatrix i j x)) : P M :=
Matrix.induction_on' M
(by
inhabit m
inhabit n
simpa using h_std_basis default default 0)
h_add h_std_basis
#align matrix.induction_on Matrix.induction_on
namespace StdBasisMatrix
section
variable (i : m) (j : n) (c : α) (i' : m) (j' : n)
@[simp]
theorem apply_same : stdBasisMatrix i j c i j = c :=
if_pos (And.intro rfl rfl)
#align matrix.std_basis_matrix.apply_same Matrix.StdBasisMatrix.apply_same
@[simp]
theorem apply_of_ne (h : ¬(i = i' ∧ j = j')) : stdBasisMatrix i j c i' j' = 0 := by
simp only [stdBasisMatrix, and_imp, ite_eq_right_iff]
tauto
#align matrix.std_basis_matrix.apply_of_ne Matrix.StdBasisMatrix.apply_of_ne
@[simp]
theorem apply_of_row_ne {i i' : m} (hi : i ≠ i') (j j' : n) (a : α) :
stdBasisMatrix i j a i' j' = 0 := by simp [hi]
#align matrix.std_basis_matrix.apply_of_row_ne Matrix.StdBasisMatrix.apply_of_row_ne
@[simp]
theorem apply_of_col_ne (i i' : m) {j j' : n} (hj : j ≠ j') (a : α) :
stdBasisMatrix i j a i' j' = 0 := by simp [hj]
#align matrix.std_basis_matrix.apply_of_col_ne Matrix.StdBasisMatrix.apply_of_col_ne
end
section
variable (i j : n) (c : α) (i' j' : n)
@[simp]
theorem diag_zero (h : j ≠ i) : diag (stdBasisMatrix i j c) = 0 :=
funext fun _ => if_neg fun ⟨e₁, e₂⟩ => h (e₂.trans e₁.symm)
#align matrix.std_basis_matrix.diag_zero Matrix.StdBasisMatrix.diag_zero
@[simp]
theorem diag_same : diag (stdBasisMatrix i i c) = Pi.single i c := by
ext j
by_cases hij : i = j <;> (try rw [hij]) <;> simp [hij]
#align matrix.std_basis_matrix.diag_same Matrix.StdBasisMatrix.diag_same
variable [Fintype n]
@[simp]
theorem trace_zero (h : j ≠ i) : trace (stdBasisMatrix i j c) = 0 := by
-- Porting note: added `-diag_apply`
simp [trace, -diag_apply, h]
#align matrix.std_basis_matrix.trace_zero Matrix.StdBasisMatrix.trace_zero
@[simp]
theorem trace_eq : trace (stdBasisMatrix i i c) = c := by
-- Porting note: added `-diag_apply`
simp [trace, -diag_apply]
#align matrix.std_basis_matrix.trace_eq Matrix.StdBasisMatrix.trace_eq
@[simp]
theorem mul_left_apply_same (b : n) (M : Matrix n n α) :
(stdBasisMatrix i j c * M) i b = c * M j b := by simp [mul_apply, stdBasisMatrix]
#align matrix.std_basis_matrix.mul_left_apply_same Matrix.StdBasisMatrix.mul_left_apply_same
@[simp]
theorem mul_right_apply_same (a : n) (M : Matrix n n α) :
(M * stdBasisMatrix i j c) a j = M a i * c := by simp [mul_apply, stdBasisMatrix, mul_comm]
#align matrix.std_basis_matrix.mul_right_apply_same Matrix.StdBasisMatrix.mul_right_apply_same
@[simp]
theorem mul_left_apply_of_ne (a b : n) (h : a ≠ i) (M : Matrix n n α) :
(stdBasisMatrix i j c * M) a b = 0 := by simp [mul_apply, h.symm]
#align matrix.std_basis_matrix.mul_left_apply_of_ne Matrix.StdBasisMatrix.mul_left_apply_of_ne
@[simp]
theorem mul_right_apply_of_ne (a b : n) (hbj : b ≠ j) (M : Matrix n n α) :
(M * stdBasisMatrix i j c) a b = 0 := by simp [mul_apply, hbj.symm]
#align matrix.std_basis_matrix.mul_right_apply_of_ne Matrix.StdBasisMatrix.mul_right_apply_of_ne
@[simp]
| Mathlib/Data/Matrix/Basis.lean | 200 | 204 | theorem mul_same (k : n) (d : α) :
stdBasisMatrix i j c * stdBasisMatrix j k d = stdBasisMatrix i k (c * d) := by |
ext a b
simp only [mul_apply, stdBasisMatrix, boole_mul]
by_cases h₁ : i = a <;> by_cases h₂ : k = b <;> simp [h₁, h₂]
|
import Mathlib.Init.Core
import Mathlib.LinearAlgebra.AffineSpace.Basis
import Mathlib.LinearAlgebra.FiniteDimensional
#align_import linear_algebra.affine_space.finite_dimensional from "leanprover-community/mathlib"@"67e606eaea14c7854bdc556bd53d98aefdf76ec0"
noncomputable section
open Affine
section AffineSpace'
variable (k : Type*) {V : Type*} {P : Type*}
variable {ι : Type*}
open AffineSubspace FiniteDimensional Module
variable [DivisionRing k] [AddCommGroup V] [Module k V] [AffineSpace V P]
theorem finiteDimensional_vectorSpan_of_finite {s : Set P} (h : Set.Finite s) :
FiniteDimensional k (vectorSpan k s) :=
span_of_finite k <| h.vsub h
#align finite_dimensional_vector_span_of_finite finiteDimensional_vectorSpan_of_finite
instance finiteDimensional_vectorSpan_range [Finite ι] (p : ι → P) :
FiniteDimensional k (vectorSpan k (Set.range p)) :=
finiteDimensional_vectorSpan_of_finite k (Set.finite_range _)
#align finite_dimensional_vector_span_range finiteDimensional_vectorSpan_range
instance finiteDimensional_vectorSpan_image_of_finite [Finite ι] (p : ι → P) (s : Set ι) :
FiniteDimensional k (vectorSpan k (p '' s)) :=
finiteDimensional_vectorSpan_of_finite k (Set.toFinite _)
#align finite_dimensional_vector_span_image_of_finite finiteDimensional_vectorSpan_image_of_finite
theorem finiteDimensional_direction_affineSpan_of_finite {s : Set P} (h : Set.Finite s) :
FiniteDimensional k (affineSpan k s).direction :=
(direction_affineSpan k s).symm ▸ finiteDimensional_vectorSpan_of_finite k h
#align finite_dimensional_direction_affine_span_of_finite finiteDimensional_direction_affineSpan_of_finite
instance finiteDimensional_direction_affineSpan_range [Finite ι] (p : ι → P) :
FiniteDimensional k (affineSpan k (Set.range p)).direction :=
finiteDimensional_direction_affineSpan_of_finite k (Set.finite_range _)
#align finite_dimensional_direction_affine_span_range finiteDimensional_direction_affineSpan_range
instance finiteDimensional_direction_affineSpan_image_of_finite [Finite ι] (p : ι → P) (s : Set ι) :
FiniteDimensional k (affineSpan k (p '' s)).direction :=
finiteDimensional_direction_affineSpan_of_finite k (Set.toFinite _)
#align finite_dimensional_direction_affine_span_image_of_finite finiteDimensional_direction_affineSpan_image_of_finite
theorem finite_of_fin_dim_affineIndependent [FiniteDimensional k V] {p : ι → P}
(hi : AffineIndependent k p) : Finite ι := by
nontriviality ι; inhabit ι
rw [affineIndependent_iff_linearIndependent_vsub k p default] at hi
letI : IsNoetherian k V := IsNoetherian.iff_fg.2 inferInstance
exact
(Set.finite_singleton default).finite_of_compl (Set.finite_coe_iff.1 hi.finite_of_isNoetherian)
#align finite_of_fin_dim_affine_independent finite_of_fin_dim_affineIndependent
theorem finite_set_of_fin_dim_affineIndependent [FiniteDimensional k V] {s : Set ι} {f : s → P}
(hi : AffineIndependent k f) : s.Finite :=
@Set.toFinite _ s (finite_of_fin_dim_affineIndependent k hi)
#align finite_set_of_fin_dim_affine_independent finite_set_of_fin_dim_affineIndependent
variable {k}
theorem AffineIndependent.finrank_vectorSpan_image_finset [DecidableEq P]
{p : ι → P} (hi : AffineIndependent k p) {s : Finset ι} {n : ℕ} (hc : Finset.card s = n + 1) :
finrank k (vectorSpan k (s.image p : Set P)) = n := by
classical
have hi' := hi.range.mono (Set.image_subset_range p ↑s)
have hc' : (s.image p).card = n + 1 := by rwa [s.card_image_of_injective hi.injective]
have hn : (s.image p).Nonempty := by simp [hc', ← Finset.card_pos]
rcases hn with ⟨p₁, hp₁⟩
have hp₁' : p₁ ∈ p '' s := by simpa using hp₁
rw [affineIndependent_set_iff_linearIndependent_vsub k hp₁', ← Finset.coe_singleton,
← Finset.coe_image, ← Finset.coe_sdiff, Finset.sdiff_singleton_eq_erase, ← Finset.coe_image]
at hi'
have hc : (Finset.image (fun p : P => p -ᵥ p₁) ((Finset.image p s).erase p₁)).card = n := by
rw [Finset.card_image_of_injective _ (vsub_left_injective _), Finset.card_erase_of_mem hp₁]
exact Nat.pred_eq_of_eq_succ hc'
rwa [vectorSpan_eq_span_vsub_finset_right_ne k hp₁, finrank_span_finset_eq_card, hc]
#align affine_independent.finrank_vector_span_image_finset AffineIndependent.finrank_vectorSpan_image_finset
theorem AffineIndependent.finrank_vectorSpan [Fintype ι] {p : ι → P} (hi : AffineIndependent k p)
{n : ℕ} (hc : Fintype.card ι = n + 1) : finrank k (vectorSpan k (Set.range p)) = n := by
classical
rw [← Finset.card_univ] at hc
rw [← Set.image_univ, ← Finset.coe_univ, ← Finset.coe_image]
exact hi.finrank_vectorSpan_image_finset hc
#align affine_independent.finrank_vector_span AffineIndependent.finrank_vectorSpan
lemma AffineIndependent.finrank_vectorSpan_add_one [Fintype ι] [Nonempty ι] {p : ι → P}
(hi : AffineIndependent k p) : finrank k (vectorSpan k (Set.range p)) + 1 = Fintype.card ι := by
rw [hi.finrank_vectorSpan (tsub_add_cancel_of_le _).symm, tsub_add_cancel_of_le] <;>
exact Fintype.card_pos
theorem AffineIndependent.vectorSpan_eq_top_of_card_eq_finrank_add_one [FiniteDimensional k V]
[Fintype ι] {p : ι → P} (hi : AffineIndependent k p) (hc : Fintype.card ι = finrank k V + 1) :
vectorSpan k (Set.range p) = ⊤ :=
Submodule.eq_top_of_finrank_eq <| hi.finrank_vectorSpan hc
#align affine_independent.vector_span_eq_top_of_card_eq_finrank_add_one AffineIndependent.vectorSpan_eq_top_of_card_eq_finrank_add_one
variable (k)
| Mathlib/LinearAlgebra/AffineSpace/FiniteDimensional.lean | 148 | 159 | theorem finrank_vectorSpan_image_finset_le [DecidableEq P] (p : ι → P) (s : Finset ι) {n : ℕ}
(hc : Finset.card s = n + 1) : finrank k (vectorSpan k (s.image p : Set P)) ≤ n := by |
classical
have hn : (s.image p).Nonempty := by
rw [Finset.image_nonempty, ← Finset.card_pos, hc]
apply Nat.succ_pos
rcases hn with ⟨p₁, hp₁⟩
rw [vectorSpan_eq_span_vsub_finset_right_ne k hp₁]
refine le_trans (finrank_span_finset_le_card (((s.image p).erase p₁).image fun p => p -ᵥ p₁)) ?_
rw [Finset.card_image_of_injective _ (vsub_left_injective p₁), Finset.card_erase_of_mem hp₁,
tsub_le_iff_right, ← hc]
apply Finset.card_image_le
|
import Mathlib.RingTheory.GradedAlgebra.HomogeneousIdeal
#align_import ring_theory.graded_algebra.radical from "leanprover-community/mathlib"@"f1944b30c97c5eb626e498307dec8b022a05bd0a"
open GradedRing DirectSum SetLike Finset
variable {ι σ A : Type*}
variable [CommRing A]
variable [LinearOrderedCancelAddCommMonoid ι]
variable [SetLike σ A] [AddSubmonoidClass σ A] {𝒜 : ι → σ} [GradedRing 𝒜]
-- Porting note: This proof needs a long time to elaborate
theorem Ideal.IsHomogeneous.isPrime_of_homogeneous_mem_or_mem {I : Ideal A} (hI : I.IsHomogeneous 𝒜)
(I_ne_top : I ≠ ⊤)
(homogeneous_mem_or_mem :
∀ {x y : A}, Homogeneous 𝒜 x → Homogeneous 𝒜 y → x * y ∈ I → x ∈ I ∨ y ∈ I) :
Ideal.IsPrime I :=
⟨I_ne_top, by
intro x y hxy
by_contra! rid
obtain ⟨rid₁, rid₂⟩ := rid
classical
set set₁ := (decompose 𝒜 x).support.filter (fun i => proj 𝒜 i x ∉ I) with set₁_eq
set set₂ := (decompose 𝒜 y).support.filter (fun i => proj 𝒜 i y ∉ I) with set₂_eq
have nonempty :
∀ x : A, x ∉ I → ((decompose 𝒜 x).support.filter (fun i => proj 𝒜 i x ∉ I)).Nonempty := by
intro x hx
rw [filter_nonempty_iff]
contrapose! hx
simp_rw [proj_apply] at hx
rw [← sum_support_decompose 𝒜 x]
exact Ideal.sum_mem _ hx
set max₁ := set₁.max' (nonempty x rid₁)
set max₂ := set₂.max' (nonempty y rid₂)
have mem_max₁ : max₁ ∈ set₁ := max'_mem set₁ (nonempty x rid₁)
have mem_max₂ : max₂ ∈ set₂ := max'_mem set₂ (nonempty y rid₂)
replace hxy : proj 𝒜 (max₁ + max₂) (x * y) ∈ I := hI _ hxy
have mem_I : proj 𝒜 max₁ x * proj 𝒜 max₂ y ∈ I := by
set antidiag :=
((decompose 𝒜 x).support ×ˢ (decompose 𝒜 y).support).filter (fun z : ι × ι =>
z.1 + z.2 = max₁ + max₂) with ha
have mem_antidiag : (max₁, max₂) ∈ antidiag := by
simp only [antidiag, add_sum_erase, mem_filter, mem_product]
exact ⟨⟨mem_of_mem_filter _ mem_max₁, mem_of_mem_filter _ mem_max₂⟩, trivial⟩
have eq_add_sum :=
calc
proj 𝒜 (max₁ + max₂) (x * y) = ∑ ij ∈ antidiag, proj 𝒜 ij.1 x * proj 𝒜 ij.2 y := by
simp_rw [ha, proj_apply, DirectSum.decompose_mul, DirectSum.coe_mul_apply 𝒜]
_ =
proj 𝒜 max₁ x * proj 𝒜 max₂ y +
∑ ij ∈ antidiag.erase (max₁, max₂), proj 𝒜 ij.1 x * proj 𝒜 ij.2 y :=
(add_sum_erase _ _ mem_antidiag).symm
rw [eq_sub_of_add_eq eq_add_sum.symm]
refine Ideal.sub_mem _ hxy (Ideal.sum_mem _ fun z H => ?_)
rcases z with ⟨i, j⟩
simp only [antidiag, mem_erase, Prod.mk.inj_iff, Ne, mem_filter, mem_product] at H
rcases H with ⟨H₁, ⟨H₂, H₃⟩, H₄⟩
have max_lt : max₁ < i ∨ max₂ < j := by
rcases lt_trichotomy max₁ i with (h | rfl | h)
· exact Or.inl h
· refine False.elim (H₁ ⟨rfl, add_left_cancel H₄⟩)
· apply Or.inr
have := add_lt_add_right h j
rw [H₄] at this
exact lt_of_add_lt_add_left this
cases' max_lt with max_lt max_lt
· -- in this case `max₁ < i`, then `xᵢ ∈ I`; for otherwise `i ∈ set₁` then `i ≤ max₁`.
have not_mem : i ∉ set₁ := fun h =>
lt_irrefl _ ((max'_lt_iff set₁ (nonempty x rid₁)).mp max_lt i h)
rw [set₁_eq] at not_mem
simp only [not_and, Classical.not_not, Ne, mem_filter] at not_mem
exact Ideal.mul_mem_right _ I (not_mem H₂)
· -- in this case `max₂ < j`, then `yⱼ ∈ I`; for otherwise `j ∈ set₂`, then `j ≤ max₂`.
have not_mem : j ∉ set₂ := fun h =>
lt_irrefl _ ((max'_lt_iff set₂ (nonempty y rid₂)).mp max_lt j h)
rw [set₂_eq] at not_mem
simp only [not_and, Classical.not_not, Ne, mem_filter] at not_mem
exact Ideal.mul_mem_left I _ (not_mem H₃)
have not_mem_I : proj 𝒜 max₁ x * proj 𝒜 max₂ y ∉ I := by
have neither_mem : proj 𝒜 max₁ x ∉ I ∧ proj 𝒜 max₂ y ∉ I := by
rw [mem_filter] at mem_max₁ mem_max₂
exact ⟨mem_max₁.2, mem_max₂.2⟩
intro _rid
cases' homogeneous_mem_or_mem ⟨max₁, SetLike.coe_mem _⟩ ⟨max₂, SetLike.coe_mem _⟩ mem_I
with h h
· apply neither_mem.1 h
· apply neither_mem.2 h
exact not_mem_I mem_I⟩
#align ideal.is_homogeneous.is_prime_of_homogeneous_mem_or_mem Ideal.IsHomogeneous.isPrime_of_homogeneous_mem_or_mem
theorem Ideal.IsHomogeneous.isPrime_iff {I : Ideal A} (h : I.IsHomogeneous 𝒜) :
I.IsPrime ↔
I ≠ ⊤ ∧
∀ {x y : A},
SetLike.Homogeneous 𝒜 x → SetLike.Homogeneous 𝒜 y → x * y ∈ I → x ∈ I ∨ y ∈ I :=
⟨fun HI => ⟨HI.ne_top, fun _ _ hxy => Ideal.IsPrime.mem_or_mem HI hxy⟩,
fun ⟨I_ne_top, homogeneous_mem_or_mem⟩ =>
h.isPrime_of_homogeneous_mem_or_mem I_ne_top @homogeneous_mem_or_mem⟩
#align ideal.is_homogeneous.is_prime_iff Ideal.IsHomogeneous.isPrime_iff
theorem Ideal.IsPrime.homogeneousCore {I : Ideal A} (h : I.IsPrime) :
(I.homogeneousCore 𝒜).toIdeal.IsPrime := by
apply (Ideal.homogeneousCore 𝒜 I).is_homogeneous'.isPrime_of_homogeneous_mem_or_mem
· exact ne_top_of_le_ne_top h.ne_top (Ideal.toIdeal_homogeneousCore_le 𝒜 I)
rintro x y hx hy hxy
have H := h.mem_or_mem (Ideal.toIdeal_homogeneousCore_le 𝒜 I hxy)
refine H.imp ?_ ?_
· exact Ideal.mem_homogeneousCore_of_homogeneous_of_mem hx
· exact Ideal.mem_homogeneousCore_of_homogeneous_of_mem hy
#align ideal.is_prime.homogeneous_core Ideal.IsPrime.homogeneousCore
| Mathlib/RingTheory/GradedAlgebra/Radical.lean | 160 | 169 | theorem Ideal.IsHomogeneous.radical_eq {I : Ideal A} (hI : I.IsHomogeneous 𝒜) :
I.radical = InfSet.sInf { J | Ideal.IsHomogeneous 𝒜 J ∧ I ≤ J ∧ J.IsPrime } := by |
rw [Ideal.radical_eq_sInf]
apply le_antisymm
· exact sInf_le_sInf fun J => And.right
· refine sInf_le_sInf_of_forall_exists_le ?_
rintro J ⟨HJ₁, HJ₂⟩
refine ⟨(J.homogeneousCore 𝒜).toIdeal, ?_, J.toIdeal_homogeneousCore_le _⟩
refine ⟨HomogeneousIdeal.isHomogeneous _, ?_, HJ₂.homogeneousCore⟩
exact hI.toIdeal_homogeneousCore_eq_self.symm.trans_le (Ideal.homogeneousCore_mono _ HJ₁)
|
import Mathlib.Computability.DFA
import Mathlib.Data.Fintype.Powerset
#align_import computability.NFA from "leanprover-community/mathlib"@"32253a1a1071173b33dc7d6a218cf722c6feb514"
open Set
open Computability
universe u v
-- Porting note: Required as `NFA` is used in mathlib3
set_option linter.uppercaseLean3 false
structure NFA (α : Type u) (σ : Type v) where
step : σ → α → Set σ
start : Set σ
accept : Set σ
#align NFA NFA
variable {α : Type u} {σ σ' : Type v} (M : NFA α σ)
namespace NFA
instance : Inhabited (NFA α σ) :=
⟨NFA.mk (fun _ _ => ∅) ∅ ∅⟩
def stepSet (S : Set σ) (a : α) : Set σ :=
⋃ s ∈ S, M.step s a
#align NFA.step_set NFA.stepSet
theorem mem_stepSet (s : σ) (S : Set σ) (a : α) : s ∈ M.stepSet S a ↔ ∃ t ∈ S, s ∈ M.step t a := by
simp [stepSet]
#align NFA.mem_step_set NFA.mem_stepSet
@[simp]
theorem stepSet_empty (a : α) : M.stepSet ∅ a = ∅ := by simp [stepSet]
#align NFA.step_set_empty NFA.stepSet_empty
def evalFrom (start : Set σ) : List α → Set σ :=
List.foldl M.stepSet start
#align NFA.eval_from NFA.evalFrom
@[simp]
theorem evalFrom_nil (S : Set σ) : M.evalFrom S [] = S :=
rfl
#align NFA.eval_from_nil NFA.evalFrom_nil
@[simp]
theorem evalFrom_singleton (S : Set σ) (a : α) : M.evalFrom S [a] = M.stepSet S a :=
rfl
#align NFA.eval_from_singleton NFA.evalFrom_singleton
@[simp]
theorem evalFrom_append_singleton (S : Set σ) (x : List α) (a : α) :
M.evalFrom S (x ++ [a]) = M.stepSet (M.evalFrom S x) a := by
simp only [evalFrom, List.foldl_append, List.foldl_cons, List.foldl_nil]
#align NFA.eval_from_append_singleton NFA.evalFrom_append_singleton
def eval : List α → Set σ :=
M.evalFrom M.start
#align NFA.eval NFA.eval
@[simp]
theorem eval_nil : M.eval [] = M.start :=
rfl
#align NFA.eval_nil NFA.eval_nil
@[simp]
theorem eval_singleton (a : α) : M.eval [a] = M.stepSet M.start a :=
rfl
#align NFA.eval_singleton NFA.eval_singleton
@[simp]
theorem eval_append_singleton (x : List α) (a : α) : M.eval (x ++ [a]) = M.stepSet (M.eval x) a :=
evalFrom_append_singleton _ _ _ _
#align NFA.eval_append_singleton NFA.eval_append_singleton
def accepts : Language α := {x | ∃ S ∈ M.accept, S ∈ M.eval x}
#align NFA.accepts NFA.accepts
| Mathlib/Computability/NFA.lean | 108 | 109 | theorem mem_accepts {x : List α} : x ∈ M.accepts ↔ ∃ S ∈ M.accept, S ∈ M.evalFrom M.start x := by |
rfl
|
import Mathlib.RingTheory.JacobsonIdeal
#align_import ring_theory.nakayama from "leanprover-community/mathlib"@"f0c8bf9245297a541f468be517f1bde6195105e9"
variable {R M : Type*} [CommRing R] [AddCommGroup M] [Module R M]
open Ideal
namespace Submodule
theorem eq_smul_of_le_smul_of_le_jacobson {I J : Ideal R} {N : Submodule R M} (hN : N.FG)
(hIN : N ≤ I • N) (hIjac : I ≤ jacobson J) : N = J • N := by
refine le_antisymm ?_ (Submodule.smul_le.2 fun _ _ _ => Submodule.smul_mem _ _)
intro n hn
cases' Submodule.exists_sub_one_mem_and_smul_eq_zero_of_fg_of_le_smul I N hN hIN with r hr
cases' exists_mul_sub_mem_of_sub_one_mem_jacobson r (hIjac hr.1) with s hs
have : n = -(s * r - 1) • n := by
rw [neg_sub, sub_smul, mul_smul, hr.2 n hn, one_smul, smul_zero, sub_zero]
rw [this]
exact Submodule.smul_mem_smul (Submodule.neg_mem _ hs) hn
#align submodule.eq_smul_of_le_smul_of_le_jacobson Submodule.eq_smul_of_le_smul_of_le_jacobson
lemma eq_bot_of_eq_ideal_smul_of_le_jacobson_annihilator {I : Ideal R}
{N : Submodule R M} (hN : FG N) (hIN : N = I • N)
(hIjac : I ≤ N.annihilator.jacobson) : N = ⊥ :=
(eq_smul_of_le_smul_of_le_jacobson hN hIN.le hIjac).trans N.annihilator_smul
open Pointwise in
lemma eq_bot_of_eq_pointwise_smul_of_mem_jacobson_annihilator {r : R}
{N : Submodule R M} (hN : FG N) (hrN : N = r • N)
(hrJac : r ∈ N.annihilator.jacobson) : N = ⊥ :=
eq_bot_of_eq_ideal_smul_of_le_jacobson_annihilator hN
(Eq.trans hrN (ideal_span_singleton_smul r N).symm)
((span_singleton_le_iff_mem r _).mpr hrJac)
open Pointwise in
lemma eq_bot_of_set_smul_eq_of_subset_jacobson_annihilator {s : Set R}
{N : Submodule R M} (hN : FG N) (hsN : N = s • N)
(hsJac : s ⊆ N.annihilator.jacobson) : N = ⊥ :=
eq_bot_of_eq_ideal_smul_of_le_jacobson_annihilator hN
(Eq.trans hsN (span_smul_eq s N).symm) (span_le.mpr hsJac)
lemma top_ne_ideal_smul_of_le_jacobson_annihilator [Nontrivial M]
[Module.Finite R M] {I} (h : I ≤ (Module.annihilator R M).jacobson) :
(⊤ : Submodule R M) ≠ I • ⊤ := fun H => top_ne_bot <|
eq_bot_of_eq_ideal_smul_of_le_jacobson_annihilator Module.Finite.out H <|
(congrArg (I ≤ Ideal.jacobson ·) annihilator_top).mpr h
open Pointwise in
lemma top_ne_set_smul_of_subset_jacobson_annihilator [Nontrivial M]
[Module.Finite R M] {s : Set R}
(h : s ⊆ (Module.annihilator R M).jacobson) :
(⊤ : Submodule R M) ≠ s • ⊤ :=
ne_of_ne_of_eq (top_ne_ideal_smul_of_le_jacobson_annihilator (span_le.mpr h))
(span_smul_eq _ _)
open Pointwise in
lemma top_ne_pointwise_smul_of_mem_jacobson_annihilator [Nontrivial M]
[Module.Finite R M] {r} (h : r ∈ (Module.annihilator R M).jacobson) :
(⊤ : Submodule R M) ≠ r • ⊤ :=
ne_of_ne_of_eq (top_ne_set_smul_of_subset_jacobson_annihilator <|
Set.singleton_subset_iff.mpr h) (singleton_set_smul ⊤ r)
theorem eq_bot_of_le_smul_of_le_jacobson_bot (I : Ideal R) (N : Submodule R M) (hN : N.FG)
(hIN : N ≤ I • N) (hIjac : I ≤ jacobson ⊥) : N = ⊥ := by
rw [eq_smul_of_le_smul_of_le_jacobson hN hIN hIjac, Submodule.bot_smul]
#align submodule.eq_bot_of_le_smul_of_le_jacobson_bot Submodule.eq_bot_of_le_smul_of_le_jacobson_bot
| Mathlib/RingTheory/Nakayama.lean | 114 | 126 | theorem sup_eq_sup_smul_of_le_smul_of_le_jacobson {I J : Ideal R} {N N' : Submodule R M}
(hN' : N'.FG) (hIJ : I ≤ jacobson J) (hNN : N' ≤ N ⊔ I • N') : N ⊔ N' = N ⊔ J • N' := by |
have hNN' : N ⊔ N' = N ⊔ I • N' :=
le_antisymm (sup_le le_sup_left hNN)
(sup_le_sup_left (Submodule.smul_le.2 fun _ _ _ => Submodule.smul_mem _ _) _)
have h_comap := Submodule.comap_injective_of_surjective (LinearMap.range_eq_top.1 N.range_mkQ)
have : (I • N').map N.mkQ = N'.map N.mkQ := by
simpa only [← h_comap.eq_iff, comap_map_mkQ, sup_comm, eq_comm] using hNN'
have :=
@Submodule.eq_smul_of_le_smul_of_le_jacobson _ _ _ _ _ I J (N'.map N.mkQ) (hN'.map _)
(by rw [← map_smul'', this]) hIJ
rwa [← map_smul'', ← h_comap.eq_iff, comap_map_eq, comap_map_eq, Submodule.ker_mkQ, sup_comm,
sup_comm (b := N)] at this
|
import Mathlib.Combinatorics.SimpleGraph.Connectivity
import Mathlib.Data.Nat.Lattice
#align_import combinatorics.simple_graph.metric from "leanprover-community/mathlib"@"352ecfe114946c903338006dd3287cb5a9955ff2"
namespace SimpleGraph
variable {V : Type*} (G : SimpleGraph V)
noncomputable def dist (u v : V) : ℕ :=
sInf (Set.range (Walk.length : G.Walk u v → ℕ))
#align simple_graph.dist SimpleGraph.dist
variable {G}
protected theorem Reachable.exists_walk_of_dist {u v : V} (hr : G.Reachable u v) :
∃ p : G.Walk u v, p.length = G.dist u v :=
Nat.sInf_mem (Set.range_nonempty_iff_nonempty.mpr hr)
#align simple_graph.reachable.exists_walk_of_dist SimpleGraph.Reachable.exists_walk_of_dist
protected theorem Connected.exists_walk_of_dist (hconn : G.Connected) (u v : V) :
∃ p : G.Walk u v, p.length = G.dist u v :=
(hconn u v).exists_walk_of_dist
#align simple_graph.connected.exists_walk_of_dist SimpleGraph.Connected.exists_walk_of_dist
theorem dist_le {u v : V} (p : G.Walk u v) : G.dist u v ≤ p.length :=
Nat.sInf_le ⟨p, rfl⟩
#align simple_graph.dist_le SimpleGraph.dist_le
@[simp]
theorem dist_eq_zero_iff_eq_or_not_reachable {u v : V} :
G.dist u v = 0 ↔ u = v ∨ ¬G.Reachable u v := by simp [dist, Nat.sInf_eq_zero, Reachable]
#align simple_graph.dist_eq_zero_iff_eq_or_not_reachable SimpleGraph.dist_eq_zero_iff_eq_or_not_reachable
theorem dist_self {v : V} : dist G v v = 0 := by simp
#align simple_graph.dist_self SimpleGraph.dist_self
protected theorem Reachable.dist_eq_zero_iff {u v : V} (hr : G.Reachable u v) :
G.dist u v = 0 ↔ u = v := by simp [hr]
#align simple_graph.reachable.dist_eq_zero_iff SimpleGraph.Reachable.dist_eq_zero_iff
protected theorem Reachable.pos_dist_of_ne {u v : V} (h : G.Reachable u v) (hne : u ≠ v) :
0 < G.dist u v :=
Nat.pos_of_ne_zero (by simp [h, hne])
#align simple_graph.reachable.pos_dist_of_ne SimpleGraph.Reachable.pos_dist_of_ne
protected theorem Connected.dist_eq_zero_iff (hconn : G.Connected) {u v : V} :
G.dist u v = 0 ↔ u = v := by simp [hconn u v]
#align simple_graph.connected.dist_eq_zero_iff SimpleGraph.Connected.dist_eq_zero_iff
protected theorem Connected.pos_dist_of_ne {u v : V} (hconn : G.Connected) (hne : u ≠ v) :
0 < G.dist u v :=
Nat.pos_of_ne_zero (by intro h; exact False.elim (hne (hconn.dist_eq_zero_iff.mp h)))
#align simple_graph.connected.pos_dist_of_ne SimpleGraph.Connected.pos_dist_of_ne
theorem dist_eq_zero_of_not_reachable {u v : V} (h : ¬G.Reachable u v) : G.dist u v = 0 := by
simp [h]
#align simple_graph.dist_eq_zero_of_not_reachable SimpleGraph.dist_eq_zero_of_not_reachable
theorem nonempty_of_pos_dist {u v : V} (h : 0 < G.dist u v) :
(Set.univ : Set (G.Walk u v)).Nonempty := by
simpa [Set.range_nonempty_iff_nonempty, Set.nonempty_iff_univ_nonempty] using
Nat.nonempty_of_pos_sInf h
#align simple_graph.nonempty_of_pos_dist SimpleGraph.nonempty_of_pos_dist
protected theorem Connected.dist_triangle (hconn : G.Connected) {u v w : V} :
G.dist u w ≤ G.dist u v + G.dist v w := by
obtain ⟨p, hp⟩ := hconn.exists_walk_of_dist u v
obtain ⟨q, hq⟩ := hconn.exists_walk_of_dist v w
rw [← hp, ← hq, ← Walk.length_append]
apply dist_le
#align simple_graph.connected.dist_triangle SimpleGraph.Connected.dist_triangle
private theorem dist_comm_aux {u v : V} (h : G.Reachable u v) : G.dist u v ≤ G.dist v u := by
obtain ⟨p, hp⟩ := h.symm.exists_walk_of_dist
rw [← hp, ← Walk.length_reverse]
apply dist_le
| Mathlib/Combinatorics/SimpleGraph/Metric.lean | 118 | 122 | theorem dist_comm {u v : V} : G.dist u v = G.dist v u := by |
by_cases h : G.Reachable u v
· apply le_antisymm (dist_comm_aux h) (dist_comm_aux h.symm)
· have h' : ¬G.Reachable v u := fun h' => absurd h'.symm h
simp [h, h', dist_eq_zero_of_not_reachable]
|
import Mathlib.Algebra.Algebra.Tower
import Mathlib.Analysis.LocallyConvex.WithSeminorms
import Mathlib.Topology.Algebra.Module.StrongTopology
import Mathlib.Analysis.NormedSpace.LinearIsometry
import Mathlib.Analysis.NormedSpace.ContinuousLinearMap
import Mathlib.Tactic.SuppressCompilation
#align_import analysis.normed_space.operator_norm from "leanprover-community/mathlib"@"f7ebde7ee0d1505dfccac8644ae12371aa3c1c9f"
suppress_compilation
open Bornology
open Filter hiding map_smul
open scoped Classical NNReal Topology Uniformity
-- the `ₗ` subscript variables are for special cases about linear (as opposed to semilinear) maps
variable {𝕜 𝕜₂ 𝕜₃ E Eₗ F Fₗ G Gₗ 𝓕 : Type*}
section SemiNormed
open Metric ContinuousLinearMap
variable [SeminormedAddCommGroup E] [SeminormedAddCommGroup Eₗ] [SeminormedAddCommGroup F]
[SeminormedAddCommGroup Fₗ] [SeminormedAddCommGroup G] [SeminormedAddCommGroup Gₗ]
variable [NontriviallyNormedField 𝕜] [NontriviallyNormedField 𝕜₂] [NontriviallyNormedField 𝕜₃]
[NormedSpace 𝕜 E] [NormedSpace 𝕜 Eₗ] [NormedSpace 𝕜₂ F] [NormedSpace 𝕜 Fₗ] [NormedSpace 𝕜₃ G]
{σ₁₂ : 𝕜 →+* 𝕜₂} {σ₂₃ : 𝕜₂ →+* 𝕜₃} {σ₁₃ : 𝕜 →+* 𝕜₃} [RingHomCompTriple σ₁₂ σ₂₃ σ₁₃]
variable [FunLike 𝓕 E F]
theorem norm_image_of_norm_zero [SemilinearMapClass 𝓕 σ₁₂ E F] (f : 𝓕) (hf : Continuous f) {x : E}
(hx : ‖x‖ = 0) : ‖f x‖ = 0 := by
rw [← mem_closure_zero_iff_norm, ← specializes_iff_mem_closure, ← map_zero f] at *
exact hx.map hf
#align norm_image_of_norm_zero norm_image_of_norm_zero
section
variable [RingHomIsometric σ₁₂] [RingHomIsometric σ₂₃]
theorem SemilinearMapClass.bound_of_shell_semi_normed [SemilinearMapClass 𝓕 σ₁₂ E F] (f : 𝓕)
{ε C : ℝ} (ε_pos : 0 < ε) {c : 𝕜} (hc : 1 < ‖c‖)
(hf : ∀ x, ε / ‖c‖ ≤ ‖x‖ → ‖x‖ < ε → ‖f x‖ ≤ C * ‖x‖) {x : E} (hx : ‖x‖ ≠ 0) :
‖f x‖ ≤ C * ‖x‖ :=
(normSeminorm 𝕜 E).bound_of_shell ((normSeminorm 𝕜₂ F).comp ⟨⟨f, map_add f⟩, map_smulₛₗ f⟩)
ε_pos hc hf hx
#align semilinear_map_class.bound_of_shell_semi_normed SemilinearMapClass.bound_of_shell_semi_normed
theorem SemilinearMapClass.bound_of_continuous [SemilinearMapClass 𝓕 σ₁₂ E F] (f : 𝓕)
(hf : Continuous f) : ∃ C, 0 < C ∧ ∀ x : E, ‖f x‖ ≤ C * ‖x‖ :=
let φ : E →ₛₗ[σ₁₂] F := ⟨⟨f, map_add f⟩, map_smulₛₗ f⟩
((normSeminorm 𝕜₂ F).comp φ).bound_of_continuous_normedSpace (continuous_norm.comp hf)
#align semilinear_map_class.bound_of_continuous SemilinearMapClass.bound_of_continuous
end
namespace ContinuousLinearMap
theorem bound [RingHomIsometric σ₁₂] (f : E →SL[σ₁₂] F) : ∃ C, 0 < C ∧ ∀ x : E, ‖f x‖ ≤ C * ‖x‖ :=
SemilinearMapClass.bound_of_continuous f f.2
#align continuous_linear_map.bound ContinuousLinearMap.bound
section
open Filter
variable (𝕜 E)
def _root_.LinearIsometry.toSpanSingleton {v : E} (hv : ‖v‖ = 1) : 𝕜 →ₗᵢ[𝕜] E :=
{ LinearMap.toSpanSingleton 𝕜 E v with norm_map' := fun x => by simp [norm_smul, hv] }
#align linear_isometry.to_span_singleton LinearIsometry.toSpanSingleton
variable {𝕜 E}
@[simp]
theorem _root_.LinearIsometry.toSpanSingleton_apply {v : E} (hv : ‖v‖ = 1) (a : 𝕜) :
LinearIsometry.toSpanSingleton 𝕜 E hv a = a • v :=
rfl
#align linear_isometry.to_span_singleton_apply LinearIsometry.toSpanSingleton_apply
@[simp]
theorem _root_.LinearIsometry.coe_toSpanSingleton {v : E} (hv : ‖v‖ = 1) :
(LinearIsometry.toSpanSingleton 𝕜 E hv).toLinearMap = LinearMap.toSpanSingleton 𝕜 E v :=
rfl
#align linear_isometry.coe_to_span_singleton LinearIsometry.coe_toSpanSingleton
end
section OpNorm
open Set Real
def opNorm (f : E →SL[σ₁₂] F) :=
sInf { c | 0 ≤ c ∧ ∀ x, ‖f x‖ ≤ c * ‖x‖ }
#align continuous_linear_map.op_norm ContinuousLinearMap.opNorm
instance hasOpNorm : Norm (E →SL[σ₁₂] F) :=
⟨opNorm⟩
#align continuous_linear_map.has_op_norm ContinuousLinearMap.hasOpNorm
theorem norm_def (f : E →SL[σ₁₂] F) : ‖f‖ = sInf { c | 0 ≤ c ∧ ∀ x, ‖f x‖ ≤ c * ‖x‖ } :=
rfl
#align continuous_linear_map.norm_def ContinuousLinearMap.norm_def
-- So that invocations of `le_csInf` make sense: we show that the set of
-- bounds is nonempty and bounded below.
theorem bounds_nonempty [RingHomIsometric σ₁₂] {f : E →SL[σ₁₂] F} :
∃ c, c ∈ { c | 0 ≤ c ∧ ∀ x, ‖f x‖ ≤ c * ‖x‖ } :=
let ⟨M, hMp, hMb⟩ := f.bound
⟨M, le_of_lt hMp, hMb⟩
#align continuous_linear_map.bounds_nonempty ContinuousLinearMap.bounds_nonempty
theorem bounds_bddBelow {f : E →SL[σ₁₂] F} : BddBelow { c | 0 ≤ c ∧ ∀ x, ‖f x‖ ≤ c * ‖x‖ } :=
⟨0, fun _ ⟨hn, _⟩ => hn⟩
#align continuous_linear_map.bounds_bdd_below ContinuousLinearMap.bounds_bddBelow
theorem isLeast_opNorm [RingHomIsometric σ₁₂] (f : E →SL[σ₁₂] F) :
IsLeast {c | 0 ≤ c ∧ ∀ x, ‖f x‖ ≤ c * ‖x‖} ‖f‖ := by
refine IsClosed.isLeast_csInf ?_ bounds_nonempty bounds_bddBelow
simp only [setOf_and, setOf_forall]
refine isClosed_Ici.inter <| isClosed_iInter fun _ ↦ isClosed_le ?_ ?_ <;> continuity
@[deprecated (since := "2024-02-02")] alias isLeast_op_norm := isLeast_opNorm
theorem opNorm_le_bound (f : E →SL[σ₁₂] F) {M : ℝ} (hMp : 0 ≤ M) (hM : ∀ x, ‖f x‖ ≤ M * ‖x‖) :
‖f‖ ≤ M :=
csInf_le bounds_bddBelow ⟨hMp, hM⟩
#align continuous_linear_map.op_norm_le_bound ContinuousLinearMap.opNorm_le_bound
@[deprecated (since := "2024-02-02")] alias op_norm_le_bound := opNorm_le_bound
theorem opNorm_le_bound' (f : E →SL[σ₁₂] F) {M : ℝ} (hMp : 0 ≤ M)
(hM : ∀ x, ‖x‖ ≠ 0 → ‖f x‖ ≤ M * ‖x‖) : ‖f‖ ≤ M :=
opNorm_le_bound f hMp fun x =>
(ne_or_eq ‖x‖ 0).elim (hM x) fun h => by
simp only [h, mul_zero, norm_image_of_norm_zero f f.2 h, le_refl]
#align continuous_linear_map.op_norm_le_bound' ContinuousLinearMap.opNorm_le_bound'
@[deprecated (since := "2024-02-02")] alias op_norm_le_bound' := opNorm_le_bound'
theorem opNorm_le_of_lipschitz {f : E →SL[σ₁₂] F} {K : ℝ≥0} (hf : LipschitzWith K f) : ‖f‖ ≤ K :=
f.opNorm_le_bound K.2 fun x => by
simpa only [dist_zero_right, f.map_zero] using hf.dist_le_mul x 0
#align continuous_linear_map.op_norm_le_of_lipschitz ContinuousLinearMap.opNorm_le_of_lipschitz
@[deprecated (since := "2024-02-02")] alias op_norm_le_of_lipschitz := opNorm_le_of_lipschitz
theorem opNorm_eq_of_bounds {φ : E →SL[σ₁₂] F} {M : ℝ} (M_nonneg : 0 ≤ M)
(h_above : ∀ x, ‖φ x‖ ≤ M * ‖x‖) (h_below : ∀ N ≥ 0, (∀ x, ‖φ x‖ ≤ N * ‖x‖) → M ≤ N) :
‖φ‖ = M :=
le_antisymm (φ.opNorm_le_bound M_nonneg h_above)
((le_csInf_iff ContinuousLinearMap.bounds_bddBelow ⟨M, M_nonneg, h_above⟩).mpr
fun N ⟨N_nonneg, hN⟩ => h_below N N_nonneg hN)
#align continuous_linear_map.op_norm_eq_of_bounds ContinuousLinearMap.opNorm_eq_of_bounds
@[deprecated (since := "2024-02-02")] alias op_norm_eq_of_bounds := opNorm_eq_of_bounds
theorem opNorm_neg (f : E →SL[σ₁₂] F) : ‖-f‖ = ‖f‖ := by simp only [norm_def, neg_apply, norm_neg]
#align continuous_linear_map.op_norm_neg ContinuousLinearMap.opNorm_neg
@[deprecated (since := "2024-02-02")] alias op_norm_neg := opNorm_neg
theorem opNorm_nonneg (f : E →SL[σ₁₂] F) : 0 ≤ ‖f‖ :=
Real.sInf_nonneg _ fun _ ↦ And.left
#align continuous_linear_map.op_norm_nonneg ContinuousLinearMap.opNorm_nonneg
@[deprecated (since := "2024-02-02")] alias op_norm_nonneg := opNorm_nonneg
theorem opNorm_zero : ‖(0 : E →SL[σ₁₂] F)‖ = 0 :=
le_antisymm (opNorm_le_bound _ le_rfl fun _ ↦ by simp) (opNorm_nonneg _)
#align continuous_linear_map.op_norm_zero ContinuousLinearMap.opNorm_zero
@[deprecated (since := "2024-02-02")] alias op_norm_zero := opNorm_zero
theorem norm_id_le : ‖id 𝕜 E‖ ≤ 1 :=
opNorm_le_bound _ zero_le_one fun x => by simp
#align continuous_linear_map.norm_id_le ContinuousLinearMap.norm_id_le
section
variable [RingHomIsometric σ₁₂] [RingHomIsometric σ₂₃] (f g : E →SL[σ₁₂] F) (h : F →SL[σ₂₃] G)
(x : E)
theorem le_opNorm : ‖f x‖ ≤ ‖f‖ * ‖x‖ := (isLeast_opNorm f).1.2 x
#align continuous_linear_map.le_op_norm ContinuousLinearMap.le_opNorm
@[deprecated (since := "2024-02-02")] alias le_op_norm := le_opNorm
theorem dist_le_opNorm (x y : E) : dist (f x) (f y) ≤ ‖f‖ * dist x y := by
simp_rw [dist_eq_norm, ← map_sub, f.le_opNorm]
#align continuous_linear_map.dist_le_op_norm ContinuousLinearMap.dist_le_opNorm
@[deprecated (since := "2024-02-02")] alias dist_le_op_norm := dist_le_opNorm
theorem le_of_opNorm_le_of_le {x} {a b : ℝ} (hf : ‖f‖ ≤ a) (hx : ‖x‖ ≤ b) :
‖f x‖ ≤ a * b :=
(f.le_opNorm x).trans <| by gcongr; exact (opNorm_nonneg f).trans hf
@[deprecated (since := "2024-02-02")] alias le_of_op_norm_le_of_le := le_of_opNorm_le_of_le
theorem le_opNorm_of_le {c : ℝ} {x} (h : ‖x‖ ≤ c) : ‖f x‖ ≤ ‖f‖ * c :=
f.le_of_opNorm_le_of_le le_rfl h
#align continuous_linear_map.le_op_norm_of_le ContinuousLinearMap.le_opNorm_of_le
@[deprecated (since := "2024-02-02")] alias le_op_norm_of_le := le_opNorm_of_le
theorem le_of_opNorm_le {c : ℝ} (h : ‖f‖ ≤ c) (x : E) : ‖f x‖ ≤ c * ‖x‖ :=
f.le_of_opNorm_le_of_le h le_rfl
#align continuous_linear_map.le_of_op_norm_le ContinuousLinearMap.le_of_opNorm_le
@[deprecated (since := "2024-02-02")] alias le_of_op_norm_le := le_of_opNorm_le
theorem opNorm_le_iff {f : E →SL[σ₁₂] F} {M : ℝ} (hMp : 0 ≤ M) :
‖f‖ ≤ M ↔ ∀ x, ‖f x‖ ≤ M * ‖x‖ :=
⟨f.le_of_opNorm_le, opNorm_le_bound f hMp⟩
@[deprecated (since := "2024-02-02")] alias op_norm_le_iff := opNorm_le_iff
theorem ratio_le_opNorm : ‖f x‖ / ‖x‖ ≤ ‖f‖ :=
div_le_of_nonneg_of_le_mul (norm_nonneg _) f.opNorm_nonneg (le_opNorm _ _)
#align continuous_linear_map.ratio_le_op_norm ContinuousLinearMap.ratio_le_opNorm
@[deprecated (since := "2024-02-02")] alias ratio_le_op_norm := ratio_le_opNorm
theorem unit_le_opNorm : ‖x‖ ≤ 1 → ‖f x‖ ≤ ‖f‖ :=
mul_one ‖f‖ ▸ f.le_opNorm_of_le
#align continuous_linear_map.unit_le_op_norm ContinuousLinearMap.unit_le_opNorm
@[deprecated (since := "2024-02-02")] alias unit_le_op_norm := unit_le_opNorm
theorem opNorm_le_of_shell {f : E →SL[σ₁₂] F} {ε C : ℝ} (ε_pos : 0 < ε) (hC : 0 ≤ C) {c : 𝕜}
(hc : 1 < ‖c‖) (hf : ∀ x, ε / ‖c‖ ≤ ‖x‖ → ‖x‖ < ε → ‖f x‖ ≤ C * ‖x‖) : ‖f‖ ≤ C :=
f.opNorm_le_bound' hC fun _ hx => SemilinearMapClass.bound_of_shell_semi_normed f ε_pos hc hf hx
#align continuous_linear_map.op_norm_le_of_shell ContinuousLinearMap.opNorm_le_of_shell
@[deprecated (since := "2024-02-02")] alias op_norm_le_of_shell := opNorm_le_of_shell
| Mathlib/Analysis/NormedSpace/OperatorNorm/Basic.lean | 275 | 279 | theorem opNorm_le_of_ball {f : E →SL[σ₁₂] F} {ε : ℝ} {C : ℝ} (ε_pos : 0 < ε) (hC : 0 ≤ C)
(hf : ∀ x ∈ ball (0 : E) ε, ‖f x‖ ≤ C * ‖x‖) : ‖f‖ ≤ C := by |
rcases NormedField.exists_one_lt_norm 𝕜 with ⟨c, hc⟩
refine opNorm_le_of_shell ε_pos hC hc fun x _ hx => hf x ?_
rwa [ball_zero_eq]
|
import Mathlib.Tactic.TFAE
import Mathlib.Topology.ContinuousOn
#align_import topology.inseparable from "leanprover-community/mathlib"@"bcfa726826abd57587355b4b5b7e78ad6527b7e4"
open Set Filter Function Topology List
variable {X Y Z α ι : Type*} {π : ι → Type*} [TopologicalSpace X] [TopologicalSpace Y]
[TopologicalSpace Z] [∀ i, TopologicalSpace (π i)] {x y z : X} {s : Set X} {f g : X → Y}
theorem specializes_TFAE (x y : X) :
TFAE [x ⤳ y,
pure x ≤ 𝓝 y,
∀ s : Set X , IsOpen s → y ∈ s → x ∈ s,
∀ s : Set X , IsClosed s → x ∈ s → y ∈ s,
y ∈ closure ({ x } : Set X),
closure ({ y } : Set X) ⊆ closure { x },
ClusterPt y (pure x)] := by
tfae_have 1 → 2
· exact (pure_le_nhds _).trans
tfae_have 2 → 3
· exact fun h s hso hy => h (hso.mem_nhds hy)
tfae_have 3 → 4
· exact fun h s hsc hx => of_not_not fun hy => h sᶜ hsc.isOpen_compl hy hx
tfae_have 4 → 5
· exact fun h => h _ isClosed_closure (subset_closure <| mem_singleton _)
tfae_have 6 ↔ 5
· exact isClosed_closure.closure_subset_iff.trans singleton_subset_iff
tfae_have 5 ↔ 7
· rw [mem_closure_iff_clusterPt, principal_singleton]
tfae_have 5 → 1
· refine fun h => (nhds_basis_opens _).ge_iff.2 ?_
rintro s ⟨hy, ho⟩
rcases mem_closure_iff.1 h s ho hy with ⟨z, hxs, rfl : z = x⟩
exact ho.mem_nhds hxs
tfae_finish
#align specializes_tfae specializes_TFAE
theorem specializes_iff_nhds : x ⤳ y ↔ 𝓝 x ≤ 𝓝 y :=
Iff.rfl
#align specializes_iff_nhds specializes_iff_nhds
theorem Specializes.not_disjoint (h : x ⤳ y) : ¬Disjoint (𝓝 x) (𝓝 y) := fun hd ↦
absurd (hd.mono_right h) <| by simp [NeBot.ne']
theorem specializes_iff_pure : x ⤳ y ↔ pure x ≤ 𝓝 y :=
(specializes_TFAE x y).out 0 1
#align specializes_iff_pure specializes_iff_pure
alias ⟨Specializes.nhds_le_nhds, _⟩ := specializes_iff_nhds
#align specializes.nhds_le_nhds Specializes.nhds_le_nhds
alias ⟨Specializes.pure_le_nhds, _⟩ := specializes_iff_pure
#align specializes.pure_le_nhds Specializes.pure_le_nhds
theorem ker_nhds_eq_specializes : (𝓝 x).ker = {y | y ⤳ x} := by
ext; simp [specializes_iff_pure, le_def]
theorem specializes_iff_forall_open : x ⤳ y ↔ ∀ s : Set X, IsOpen s → y ∈ s → x ∈ s :=
(specializes_TFAE x y).out 0 2
#align specializes_iff_forall_open specializes_iff_forall_open
theorem Specializes.mem_open (h : x ⤳ y) (hs : IsOpen s) (hy : y ∈ s) : x ∈ s :=
specializes_iff_forall_open.1 h s hs hy
#align specializes.mem_open Specializes.mem_open
theorem IsOpen.not_specializes (hs : IsOpen s) (hx : x ∉ s) (hy : y ∈ s) : ¬x ⤳ y := fun h =>
hx <| h.mem_open hs hy
#align is_open.not_specializes IsOpen.not_specializes
theorem specializes_iff_forall_closed : x ⤳ y ↔ ∀ s : Set X, IsClosed s → x ∈ s → y ∈ s :=
(specializes_TFAE x y).out 0 3
#align specializes_iff_forall_closed specializes_iff_forall_closed
theorem Specializes.mem_closed (h : x ⤳ y) (hs : IsClosed s) (hx : x ∈ s) : y ∈ s :=
specializes_iff_forall_closed.1 h s hs hx
#align specializes.mem_closed Specializes.mem_closed
theorem IsClosed.not_specializes (hs : IsClosed s) (hx : x ∈ s) (hy : y ∉ s) : ¬x ⤳ y := fun h =>
hy <| h.mem_closed hs hx
#align is_closed.not_specializes IsClosed.not_specializes
theorem specializes_iff_mem_closure : x ⤳ y ↔ y ∈ closure ({x} : Set X) :=
(specializes_TFAE x y).out 0 4
#align specializes_iff_mem_closure specializes_iff_mem_closure
alias ⟨Specializes.mem_closure, _⟩ := specializes_iff_mem_closure
#align specializes.mem_closure Specializes.mem_closure
theorem specializes_iff_closure_subset : x ⤳ y ↔ closure ({y} : Set X) ⊆ closure {x} :=
(specializes_TFAE x y).out 0 5
#align specializes_iff_closure_subset specializes_iff_closure_subset
alias ⟨Specializes.closure_subset, _⟩ := specializes_iff_closure_subset
#align specializes.closure_subset Specializes.closure_subset
-- Porting note (#10756): new lemma
theorem specializes_iff_clusterPt : x ⤳ y ↔ ClusterPt y (pure x) :=
(specializes_TFAE x y).out 0 6
theorem Filter.HasBasis.specializes_iff {ι} {p : ι → Prop} {s : ι → Set X}
(h : (𝓝 y).HasBasis p s) : x ⤳ y ↔ ∀ i, p i → x ∈ s i :=
specializes_iff_pure.trans h.ge_iff
#align filter.has_basis.specializes_iff Filter.HasBasis.specializes_iff
theorem specializes_rfl : x ⤳ x := le_rfl
#align specializes_rfl specializes_rfl
@[refl]
theorem specializes_refl (x : X) : x ⤳ x :=
specializes_rfl
#align specializes_refl specializes_refl
@[trans]
theorem Specializes.trans : x ⤳ y → y ⤳ z → x ⤳ z :=
le_trans
#align specializes.trans Specializes.trans
theorem specializes_of_eq (e : x = y) : x ⤳ y :=
e ▸ specializes_refl x
#align specializes_of_eq specializes_of_eq
theorem specializes_of_nhdsWithin (h₁ : 𝓝[s] x ≤ 𝓝[s] y) (h₂ : x ∈ s) : x ⤳ y :=
specializes_iff_pure.2 <|
calc
pure x ≤ 𝓝[s] x := le_inf (pure_le_nhds _) (le_principal_iff.2 h₂)
_ ≤ 𝓝[s] y := h₁
_ ≤ 𝓝 y := inf_le_left
#align specializes_of_nhds_within specializes_of_nhdsWithin
theorem Specializes.map_of_continuousAt (h : x ⤳ y) (hy : ContinuousAt f y) : f x ⤳ f y :=
specializes_iff_pure.2 fun _s hs =>
mem_pure.2 <| mem_preimage.1 <| mem_of_mem_nhds <| hy.mono_left h hs
#align specializes.map_of_continuous_at Specializes.map_of_continuousAt
theorem Specializes.map (h : x ⤳ y) (hf : Continuous f) : f x ⤳ f y :=
h.map_of_continuousAt hf.continuousAt
#align specializes.map Specializes.map
theorem Inducing.specializes_iff (hf : Inducing f) : f x ⤳ f y ↔ x ⤳ y := by
simp only [specializes_iff_mem_closure, hf.closure_eq_preimage_closure_image, image_singleton,
mem_preimage]
#align inducing.specializes_iff Inducing.specializes_iff
theorem subtype_specializes_iff {p : X → Prop} (x y : Subtype p) : x ⤳ y ↔ (x : X) ⤳ y :=
inducing_subtype_val.specializes_iff.symm
#align subtype_specializes_iff subtype_specializes_iff
@[simp]
theorem specializes_prod {x₁ x₂ : X} {y₁ y₂ : Y} : (x₁, y₁) ⤳ (x₂, y₂) ↔ x₁ ⤳ x₂ ∧ y₁ ⤳ y₂ := by
simp only [Specializes, nhds_prod_eq, prod_le_prod]
#align specializes_prod specializes_prod
theorem Specializes.prod {x₁ x₂ : X} {y₁ y₂ : Y} (hx : x₁ ⤳ x₂) (hy : y₁ ⤳ y₂) :
(x₁, y₁) ⤳ (x₂, y₂) :=
specializes_prod.2 ⟨hx, hy⟩
#align specializes.prod Specializes.prod
theorem Specializes.fst {a b : X × Y} (h : a ⤳ b) : a.1 ⤳ b.1 := (specializes_prod.1 h).1
theorem Specializes.snd {a b : X × Y} (h : a ⤳ b) : a.2 ⤳ b.2 := (specializes_prod.1 h).2
@[simp]
theorem specializes_pi {f g : ∀ i, π i} : f ⤳ g ↔ ∀ i, f i ⤳ g i := by
simp only [Specializes, nhds_pi, pi_le_pi]
#align specializes_pi specializes_pi
theorem not_specializes_iff_exists_open : ¬x ⤳ y ↔ ∃ S : Set X, IsOpen S ∧ y ∈ S ∧ x ∉ S := by
rw [specializes_iff_forall_open]
push_neg
rfl
#align not_specializes_iff_exists_open not_specializes_iff_exists_open
theorem not_specializes_iff_exists_closed : ¬x ⤳ y ↔ ∃ S : Set X, IsClosed S ∧ x ∈ S ∧ y ∉ S := by
rw [specializes_iff_forall_closed]
push_neg
rfl
#align not_specializes_iff_exists_closed not_specializes_iff_exists_closed
theorem IsOpen.continuous_piecewise_of_specializes [DecidablePred (· ∈ s)] (hs : IsOpen s)
(hf : Continuous f) (hg : Continuous g) (hspec : ∀ x, f x ⤳ g x) :
Continuous (s.piecewise f g) := by
have : ∀ U, IsOpen U → g ⁻¹' U ⊆ f ⁻¹' U := fun U hU x hx ↦ (hspec x).mem_open hU hx
rw [continuous_def]
intro U hU
rw [piecewise_preimage, ite_eq_of_subset_right _ (this U hU)]
exact hU.preimage hf |>.inter hs |>.union (hU.preimage hg)
theorem IsClosed.continuous_piecewise_of_specializes [DecidablePred (· ∈ s)] (hs : IsClosed s)
(hf : Continuous f) (hg : Continuous g) (hspec : ∀ x, g x ⤳ f x) :
Continuous (s.piecewise f g) := by
simpa only [piecewise_compl] using hs.isOpen_compl.continuous_piecewise_of_specializes hg hf hspec
theorem Continuous.specialization_monotone (hf : Continuous f) :
@Monotone _ _ (specializationPreorder X) (specializationPreorder Y) f := fun _ _ h => h.map hf
#align continuous.specialization_monotone Continuous.specialization_monotone
local infixl:0 " ~ᵢ " => Inseparable
theorem inseparable_def : (x ~ᵢ y) ↔ 𝓝 x = 𝓝 y :=
Iff.rfl
#align inseparable_def inseparable_def
theorem inseparable_iff_specializes_and : (x ~ᵢ y) ↔ x ⤳ y ∧ y ⤳ x :=
le_antisymm_iff
#align inseparable_iff_specializes_and inseparable_iff_specializes_and
theorem Inseparable.specializes (h : x ~ᵢ y) : x ⤳ y := h.le
#align inseparable.specializes Inseparable.specializes
theorem Inseparable.specializes' (h : x ~ᵢ y) : y ⤳ x := h.ge
#align inseparable.specializes' Inseparable.specializes'
theorem Specializes.antisymm (h₁ : x ⤳ y) (h₂ : y ⤳ x) : x ~ᵢ y :=
le_antisymm h₁ h₂
#align specializes.antisymm Specializes.antisymm
theorem inseparable_iff_forall_open : (x ~ᵢ y) ↔ ∀ s : Set X, IsOpen s → (x ∈ s ↔ y ∈ s) := by
simp only [inseparable_iff_specializes_and, specializes_iff_forall_open, ← forall_and, ← iff_def,
Iff.comm]
#align inseparable_iff_forall_open inseparable_iff_forall_open
theorem not_inseparable_iff_exists_open :
¬(x ~ᵢ y) ↔ ∃ s : Set X, IsOpen s ∧ Xor' (x ∈ s) (y ∈ s) := by
simp [inseparable_iff_forall_open, ← xor_iff_not_iff]
#align not_inseparable_iff_exists_open not_inseparable_iff_exists_open
theorem inseparable_iff_forall_closed : (x ~ᵢ y) ↔ ∀ s : Set X, IsClosed s → (x ∈ s ↔ y ∈ s) := by
simp only [inseparable_iff_specializes_and, specializes_iff_forall_closed, ← forall_and, ←
iff_def]
#align inseparable_iff_forall_closed inseparable_iff_forall_closed
theorem inseparable_iff_mem_closure :
(x ~ᵢ y) ↔ x ∈ closure ({y} : Set X) ∧ y ∈ closure ({x} : Set X) :=
inseparable_iff_specializes_and.trans <| by simp only [specializes_iff_mem_closure, and_comm]
#align inseparable_iff_mem_closure inseparable_iff_mem_closure
theorem inseparable_iff_closure_eq : (x ~ᵢ y) ↔ closure ({x} : Set X) = closure {y} := by
simp only [inseparable_iff_specializes_and, specializes_iff_closure_subset, ← subset_antisymm_iff,
eq_comm]
#align inseparable_iff_closure_eq inseparable_iff_closure_eq
theorem inseparable_of_nhdsWithin_eq (hx : x ∈ s) (hy : y ∈ s) (h : 𝓝[s] x = 𝓝[s] y) : x ~ᵢ y :=
(specializes_of_nhdsWithin h.le hx).antisymm (specializes_of_nhdsWithin h.ge hy)
#align inseparable_of_nhds_within_eq inseparable_of_nhdsWithin_eq
theorem Inducing.inseparable_iff (hf : Inducing f) : (f x ~ᵢ f y) ↔ (x ~ᵢ y) := by
simp only [inseparable_iff_specializes_and, hf.specializes_iff]
#align inducing.inseparable_iff Inducing.inseparable_iff
theorem subtype_inseparable_iff {p : X → Prop} (x y : Subtype p) : (x ~ᵢ y) ↔ ((x : X) ~ᵢ y) :=
inducing_subtype_val.inseparable_iff.symm
#align subtype_inseparable_iff subtype_inseparable_iff
@[simp] theorem inseparable_prod {x₁ x₂ : X} {y₁ y₂ : Y} :
((x₁, y₁) ~ᵢ (x₂, y₂)) ↔ (x₁ ~ᵢ x₂) ∧ (y₁ ~ᵢ y₂) := by
simp only [Inseparable, nhds_prod_eq, prod_inj]
#align inseparable_prod inseparable_prod
theorem Inseparable.prod {x₁ x₂ : X} {y₁ y₂ : Y} (hx : x₁ ~ᵢ x₂) (hy : y₁ ~ᵢ y₂) :
(x₁, y₁) ~ᵢ (x₂, y₂) :=
inseparable_prod.2 ⟨hx, hy⟩
#align inseparable.prod Inseparable.prod
@[simp]
| Mathlib/Topology/Inseparable.lean | 310 | 311 | theorem inseparable_pi {f g : ∀ i, π i} : (f ~ᵢ g) ↔ ∀ i, f i ~ᵢ g i := by |
simp only [Inseparable, nhds_pi, funext_iff, pi_inj]
|
import Mathlib.Algebra.Order.Ring.Nat
#align_import data.nat.dist from "leanprover-community/mathlib"@"d50b12ae8e2bd910d08a94823976adae9825718b"
namespace Nat
def dist (n m : ℕ) :=
n - m + (m - n)
#align nat.dist Nat.dist
-- Should be aligned to `Nat.dist.eq_def`, but that is generated on demand and isn't present yet.
#noalign nat.dist.def
theorem dist_comm (n m : ℕ) : dist n m = dist m n := by simp [dist, add_comm]
#align nat.dist_comm Nat.dist_comm
@[simp]
theorem dist_self (n : ℕ) : dist n n = 0 := by simp [dist, tsub_self]
#align nat.dist_self Nat.dist_self
theorem eq_of_dist_eq_zero {n m : ℕ} (h : dist n m = 0) : n = m :=
have : n - m = 0 := Nat.eq_zero_of_add_eq_zero_right h
have : n ≤ m := tsub_eq_zero_iff_le.mp this
have : m - n = 0 := Nat.eq_zero_of_add_eq_zero_left h
have : m ≤ n := tsub_eq_zero_iff_le.mp this
le_antisymm ‹n ≤ m› ‹m ≤ n›
#align nat.eq_of_dist_eq_zero Nat.eq_of_dist_eq_zero
| Mathlib/Data/Nat/Dist.lean | 42 | 42 | theorem dist_eq_zero {n m : ℕ} (h : n = m) : dist n m = 0 := by | rw [h, dist_self]
|
import Mathlib.LinearAlgebra.Basis
import Mathlib.LinearAlgebra.Dual
import Mathlib.Data.Fin.FlagRange
open Set Submodule
namespace Basis
section Semiring
variable {R M : Type*} [Semiring R] [AddCommMonoid M] [Module R M] {n : ℕ}
def flag (b : Basis (Fin n) R M) (k : Fin (n + 1)) : Submodule R M :=
.span R <| b '' {i | i.castSucc < k}
@[simp]
| Mathlib/LinearAlgebra/Basis/Flag.lean | 32 | 32 | theorem flag_zero (b : Basis (Fin n) R M) : b.flag 0 = ⊥ := by | simp [flag]
|
import Mathlib.Algebra.Group.Hom.Defs
#align_import algebra.group.ext from "leanprover-community/mathlib"@"e574b1a4e891376b0ef974b926da39e05da12a06"
assert_not_exists MonoidWithZero
assert_not_exists DenselyOrdered
open Function
universe u
@[to_additive (attr := ext)]
theorem Monoid.ext {M : Type u} ⦃m₁ m₂ : Monoid M⦄
(h_mul : (letI := m₁; HMul.hMul : M → M → M) = (letI := m₂; HMul.hMul : M → M → M)) :
m₁ = m₂ := by
have : m₁.toMulOneClass = m₂.toMulOneClass := MulOneClass.ext h_mul
have h₁ : m₁.one = m₂.one := congr_arg (·.one) this
let f : @MonoidHom M M m₁.toMulOneClass m₂.toMulOneClass :=
@MonoidHom.mk _ _ (_) _ (@OneHom.mk _ _ (_) _ id h₁)
(fun x y => congr_fun (congr_fun h_mul x) y)
have : m₁.npow = m₂.npow := by
ext n x
exact @MonoidHom.map_pow M M m₁ m₂ f x n
rcases m₁ with @⟨@⟨⟨_⟩⟩, ⟨_⟩⟩
rcases m₂ with @⟨@⟨⟨_⟩⟩, ⟨_⟩⟩
congr
#align monoid.ext Monoid.ext
#align add_monoid.ext AddMonoid.ext
@[to_additive]
theorem CommMonoid.toMonoid_injective {M : Type u} :
Function.Injective (@CommMonoid.toMonoid M) := by
rintro ⟨⟩ ⟨⟩ h
congr
#align comm_monoid.to_monoid_injective CommMonoid.toMonoid_injective
#align add_comm_monoid.to_add_monoid_injective AddCommMonoid.toAddMonoid_injective
@[to_additive (attr := ext)]
theorem CommMonoid.ext {M : Type*} ⦃m₁ m₂ : CommMonoid M⦄
(h_mul : (letI := m₁; HMul.hMul : M → M → M) = (letI := m₂; HMul.hMul : M → M → M)) : m₁ = m₂ :=
CommMonoid.toMonoid_injective <| Monoid.ext h_mul
#align comm_monoid.ext CommMonoid.ext
#align add_comm_monoid.ext AddCommMonoid.ext
@[to_additive]
theorem LeftCancelMonoid.toMonoid_injective {M : Type u} :
Function.Injective (@LeftCancelMonoid.toMonoid M) := by
rintro @⟨@⟨⟩⟩ @⟨@⟨⟩⟩ h
congr <;> injection h
#align left_cancel_monoid.to_monoid_injective LeftCancelMonoid.toMonoid_injective
#align add_left_cancel_monoid.to_add_monoid_injective AddLeftCancelMonoid.toAddMonoid_injective
@[to_additive (attr := ext)]
theorem LeftCancelMonoid.ext {M : Type u} ⦃m₁ m₂ : LeftCancelMonoid M⦄
(h_mul : (letI := m₁; HMul.hMul : M → M → M) = (letI := m₂; HMul.hMul : M → M → M)) :
m₁ = m₂ :=
LeftCancelMonoid.toMonoid_injective <| Monoid.ext h_mul
#align left_cancel_monoid.ext LeftCancelMonoid.ext
#align add_left_cancel_monoid.ext AddLeftCancelMonoid.ext
@[to_additive]
theorem RightCancelMonoid.toMonoid_injective {M : Type u} :
Function.Injective (@RightCancelMonoid.toMonoid M) := by
rintro @⟨@⟨⟩⟩ @⟨@⟨⟩⟩ h
congr <;> injection h
#align right_cancel_monoid.to_monoid_injective RightCancelMonoid.toMonoid_injective
#align add_right_cancel_monoid.to_add_monoid_injective AddRightCancelMonoid.toAddMonoid_injective
@[to_additive (attr := ext)]
theorem RightCancelMonoid.ext {M : Type u} ⦃m₁ m₂ : RightCancelMonoid M⦄
(h_mul : (letI := m₁; HMul.hMul : M → M → M) = (letI := m₂; HMul.hMul : M → M → M)) :
m₁ = m₂ :=
RightCancelMonoid.toMonoid_injective <| Monoid.ext h_mul
#align right_cancel_monoid.ext RightCancelMonoid.ext
#align add_right_cancel_monoid.ext AddRightCancelMonoid.ext
@[to_additive]
theorem CancelMonoid.toLeftCancelMonoid_injective {M : Type u} :
Function.Injective (@CancelMonoid.toLeftCancelMonoid M) := by
rintro ⟨⟩ ⟨⟩ h
congr
#align cancel_monoid.to_left_cancel_monoid_injective CancelMonoid.toLeftCancelMonoid_injective
#align add_cancel_monoid.to_left_cancel_add_monoid_injective AddCancelMonoid.toAddLeftCancelMonoid_injective
@[to_additive (attr := ext)]
theorem CancelMonoid.ext {M : Type*} ⦃m₁ m₂ : CancelMonoid M⦄
(h_mul : (letI := m₁; HMul.hMul : M → M → M) = (letI := m₂; HMul.hMul : M → M → M)) :
m₁ = m₂ :=
CancelMonoid.toLeftCancelMonoid_injective <| LeftCancelMonoid.ext h_mul
#align cancel_monoid.ext CancelMonoid.ext
#align add_cancel_monoid.ext AddCancelMonoid.ext
@[to_additive]
| Mathlib/Algebra/Group/Ext.lean | 119 | 124 | theorem CancelCommMonoid.toCommMonoid_injective {M : Type u} :
Function.Injective (@CancelCommMonoid.toCommMonoid M) := by |
rintro @⟨@⟨@⟨⟩⟩⟩ @⟨@⟨@⟨⟩⟩⟩ h
congr <;> {
injection h with h'
injection h' }
|
import Mathlib.Geometry.Manifold.MFDeriv.SpecificFunctions
noncomputable section
open scoped Manifold
open Bundle Set Topology
variable {𝕜 : Type*} [NontriviallyNormedField 𝕜]
{E : Type*} [NormedAddCommGroup E] [NormedSpace 𝕜 E] {H : Type*} [TopologicalSpace H]
(I : ModelWithCorners 𝕜 E H) {M : Type*} [TopologicalSpace M] [ChartedSpace H M]
{E' : Type*} [NormedAddCommGroup E'] [NormedSpace 𝕜 E'] {H' : Type*} [TopologicalSpace H']
(I' : ModelWithCorners 𝕜 E' H') {M' : Type*} [TopologicalSpace M'] [ChartedSpace H' M']
{E'' : Type*} [NormedAddCommGroup E''] [NormedSpace 𝕜 E''] {H'' : Type*} [TopologicalSpace H'']
(I'' : ModelWithCorners 𝕜 E'' H'') {M'' : Type*} [TopologicalSpace M''] [ChartedSpace H'' M'']
section Charts
variable [SmoothManifoldWithCorners I M] [SmoothManifoldWithCorners I' M']
[SmoothManifoldWithCorners I'' M''] {e : PartialHomeomorph M H}
| Mathlib/Geometry/Manifold/MFDeriv/Atlas.lean | 89 | 106 | theorem mdifferentiableAt_atlas (h : e ∈ atlas H M) {x : M} (hx : x ∈ e.source) :
MDifferentiableAt I I e x := by |
rw [mdifferentiableAt_iff]
refine ⟨(e.continuousOn x hx).continuousAt (e.open_source.mem_nhds hx), ?_⟩
have mem :
I ((chartAt H x : M → H) x) ∈ I.symm ⁻¹' ((chartAt H x).symm ≫ₕ e).source ∩ range I := by
simp only [hx, mfld_simps]
have : (chartAt H x).symm.trans e ∈ contDiffGroupoid ∞ I :=
HasGroupoid.compatible (chart_mem_atlas H x) h
have A :
ContDiffOn 𝕜 ∞ (I ∘ (chartAt H x).symm.trans e ∘ I.symm)
(I.symm ⁻¹' ((chartAt H x).symm.trans e).source ∩ range I) :=
this.1
have B := A.differentiableOn le_top (I ((chartAt H x : M → H) x)) mem
simp only [mfld_simps] at B
rw [inter_comm, differentiableWithinAt_inter] at B
· simpa only [mfld_simps]
· apply IsOpen.mem_nhds ((PartialHomeomorph.open_source _).preimage I.continuous_symm) mem.1
|
import Mathlib.Topology.Bases
import Mathlib.Order.Filter.CountableInter
import Mathlib.Topology.Compactness.SigmaCompact
open Set Filter Topology TopologicalSpace
universe u v
variable {X : Type u} {Y : Type v} {ι : Type*}
variable [TopologicalSpace X] [TopologicalSpace Y] {s t : Set X}
section Lindelof
def IsLindelof (s : Set X) :=
∀ ⦃f⦄ [NeBot f] [CountableInterFilter f], f ≤ 𝓟 s → ∃ x ∈ s, ClusterPt x f
theorem IsLindelof.compl_mem_sets (hs : IsLindelof s) {f : Filter X} [CountableInterFilter f]
(hf : ∀ x ∈ s, sᶜ ∈ 𝓝 x ⊓ f) : sᶜ ∈ f := by
contrapose! hf
simp only [not_mem_iff_inf_principal_compl, compl_compl, inf_assoc] at hf ⊢
exact hs inf_le_right
theorem IsLindelof.compl_mem_sets_of_nhdsWithin (hs : IsLindelof s) {f : Filter X}
[CountableInterFilter f] (hf : ∀ x ∈ s, ∃ t ∈ 𝓝[s] x, tᶜ ∈ f) : sᶜ ∈ f := by
refine hs.compl_mem_sets fun x hx ↦ ?_
rw [← disjoint_principal_right, disjoint_right_comm, (basis_sets _).disjoint_iff_left]
exact hf x hx
@[elab_as_elim]
theorem IsLindelof.induction_on (hs : IsLindelof s) {p : Set X → Prop}
(hmono : ∀ ⦃s t⦄, s ⊆ t → p t → p s)
(hcountable_union : ∀ (S : Set (Set X)), S.Countable → (∀ s ∈ S, p s) → p (⋃₀ S))
(hnhds : ∀ x ∈ s, ∃ t ∈ 𝓝[s] x, p t) : p s := by
let f : Filter X := ofCountableUnion p hcountable_union (fun t ht _ hsub ↦ hmono hsub ht)
have : sᶜ ∈ f := hs.compl_mem_sets_of_nhdsWithin (by simpa [f] using hnhds)
rwa [← compl_compl s]
theorem IsLindelof.inter_right (hs : IsLindelof s) (ht : IsClosed t) : IsLindelof (s ∩ t) := by
intro f hnf _ hstf
rw [← inf_principal, le_inf_iff] at hstf
obtain ⟨x, hsx, hx⟩ : ∃ x ∈ s, ClusterPt x f := hs hstf.1
have hxt : x ∈ t := ht.mem_of_nhdsWithin_neBot <| hx.mono hstf.2
exact ⟨x, ⟨hsx, hxt⟩, hx⟩
theorem IsLindelof.inter_left (ht : IsLindelof t) (hs : IsClosed s) : IsLindelof (s ∩ t) :=
inter_comm t s ▸ ht.inter_right hs
theorem IsLindelof.diff (hs : IsLindelof s) (ht : IsOpen t) : IsLindelof (s \ t) :=
hs.inter_right (isClosed_compl_iff.mpr ht)
theorem IsLindelof.of_isClosed_subset (hs : IsLindelof s) (ht : IsClosed t) (h : t ⊆ s) :
IsLindelof t := inter_eq_self_of_subset_right h ▸ hs.inter_right ht
theorem IsLindelof.image_of_continuousOn {f : X → Y} (hs : IsLindelof s) (hf : ContinuousOn f s) :
IsLindelof (f '' s) := by
intro l lne _ ls
have : NeBot (l.comap f ⊓ 𝓟 s) :=
comap_inf_principal_neBot_of_image_mem lne (le_principal_iff.1 ls)
obtain ⟨x, hxs, hx⟩ : ∃ x ∈ s, ClusterPt x (l.comap f ⊓ 𝓟 s) := @hs _ this _ inf_le_right
haveI := hx.neBot
use f x, mem_image_of_mem f hxs
have : Tendsto f (𝓝 x ⊓ (comap f l ⊓ 𝓟 s)) (𝓝 (f x) ⊓ l) := by
convert (hf x hxs).inf (@tendsto_comap _ _ f l) using 1
rw [nhdsWithin]
ac_rfl
exact this.neBot
theorem IsLindelof.image {f : X → Y} (hs : IsLindelof s) (hf : Continuous f) :
IsLindelof (f '' s) := hs.image_of_continuousOn hf.continuousOn
theorem IsLindelof.adherence_nhdset {f : Filter X} [CountableInterFilter f] (hs : IsLindelof s)
(hf₂ : f ≤ 𝓟 s) (ht₁ : IsOpen t) (ht₂ : ∀ x ∈ s, ClusterPt x f → x ∈ t) : t ∈ f :=
(eq_or_neBot _).casesOn mem_of_eq_bot fun _ ↦
let ⟨x, hx, hfx⟩ := @hs (f ⊓ 𝓟 tᶜ) _ _ <| inf_le_of_left_le hf₂
have : x ∈ t := ht₂ x hx hfx.of_inf_left
have : tᶜ ∩ t ∈ 𝓝[tᶜ] x := inter_mem_nhdsWithin _ (ht₁.mem_nhds this)
have A : 𝓝[tᶜ] x = ⊥ := empty_mem_iff_bot.1 <| compl_inter_self t ▸ this
have : 𝓝[tᶜ] x ≠ ⊥ := hfx.of_inf_right.ne
absurd A this
theorem IsLindelof.elim_countable_subcover {ι : Type v} (hs : IsLindelof s) (U : ι → Set X)
(hUo : ∀ i, IsOpen (U i)) (hsU : s ⊆ ⋃ i, U i) :
∃ r : Set ι, r.Countable ∧ (s ⊆ ⋃ i ∈ r, U i) := by
have hmono : ∀ ⦃s t : Set X⦄, s ⊆ t → (∃ r : Set ι, r.Countable ∧ t ⊆ ⋃ i ∈ r, U i)
→ (∃ r : Set ι, r.Countable ∧ s ⊆ ⋃ i ∈ r, U i) := by
intro _ _ hst ⟨r, ⟨hrcountable, hsub⟩⟩
exact ⟨r, hrcountable, Subset.trans hst hsub⟩
have hcountable_union : ∀ (S : Set (Set X)), S.Countable
→ (∀ s ∈ S, ∃ r : Set ι, r.Countable ∧ (s ⊆ ⋃ i ∈ r, U i))
→ ∃ r : Set ι, r.Countable ∧ (⋃₀ S ⊆ ⋃ i ∈ r, U i) := by
intro S hS hsr
choose! r hr using hsr
refine ⟨⋃ s ∈ S, r s, hS.biUnion_iff.mpr (fun s hs ↦ (hr s hs).1), ?_⟩
refine sUnion_subset ?h.right.h
simp only [mem_iUnion, exists_prop, iUnion_exists, biUnion_and']
exact fun i is x hx ↦ mem_biUnion is ((hr i is).2 hx)
have h_nhds : ∀ x ∈ s, ∃ t ∈ 𝓝[s] x, ∃ r : Set ι, r.Countable ∧ (t ⊆ ⋃ i ∈ r, U i) := by
intro x hx
let ⟨i, hi⟩ := mem_iUnion.1 (hsU hx)
refine ⟨U i, mem_nhdsWithin_of_mem_nhds ((hUo i).mem_nhds hi), {i}, by simp, ?_⟩
simp only [mem_singleton_iff, iUnion_iUnion_eq_left]
exact Subset.refl _
exact hs.induction_on hmono hcountable_union h_nhds
theorem IsLindelof.elim_nhds_subcover' (hs : IsLindelof s) (U : ∀ x ∈ s, Set X)
(hU : ∀ x (hx : x ∈ s), U x ‹x ∈ s› ∈ 𝓝 x) :
∃ t : Set s, t.Countable ∧ s ⊆ ⋃ x ∈ t, U (x : s) x.2 := by
have := hs.elim_countable_subcover (fun x : s ↦ interior (U x x.2)) (fun _ ↦ isOpen_interior)
fun x hx ↦
mem_iUnion.2 ⟨⟨x, hx⟩, mem_interior_iff_mem_nhds.2 <| hU _ _⟩
rcases this with ⟨r, ⟨hr, hs⟩⟩
use r, hr
apply Subset.trans hs
apply iUnion₂_subset
intro i hi
apply Subset.trans interior_subset
exact subset_iUnion_of_subset i (subset_iUnion_of_subset hi (Subset.refl _))
theorem IsLindelof.elim_nhds_subcover (hs : IsLindelof s) (U : X → Set X)
(hU : ∀ x ∈ s, U x ∈ 𝓝 x) :
∃ t : Set X, t.Countable ∧ (∀ x ∈ t, x ∈ s) ∧ s ⊆ ⋃ x ∈ t, U x := by
let ⟨t, ⟨htc, htsub⟩⟩ := hs.elim_nhds_subcover' (fun x _ ↦ U x) hU
refine ⟨↑t, Countable.image htc Subtype.val, ?_⟩
constructor
· intro _
simp only [mem_image, Subtype.exists, exists_and_right, exists_eq_right, forall_exists_index]
tauto
· have : ⋃ x ∈ t, U ↑x = ⋃ x ∈ Subtype.val '' t, U x := biUnion_image.symm
rwa [← this]
theorem IsLindelof.disjoint_nhdsSet_left {l : Filter X} [CountableInterFilter l]
(hs : IsLindelof s) :
Disjoint (𝓝ˢ s) l ↔ ∀ x ∈ s, Disjoint (𝓝 x) l := by
refine ⟨fun h x hx ↦ h.mono_left <| nhds_le_nhdsSet hx, fun H ↦ ?_⟩
choose! U hxU hUl using fun x hx ↦ (nhds_basis_opens x).disjoint_iff_left.1 (H x hx)
choose hxU hUo using hxU
rcases hs.elim_nhds_subcover U fun x hx ↦ (hUo x hx).mem_nhds (hxU x hx) with ⟨t, htc, hts, hst⟩
refine (hasBasis_nhdsSet _).disjoint_iff_left.2
⟨⋃ x ∈ t, U x, ⟨isOpen_biUnion fun x hx ↦ hUo x (hts x hx), hst⟩, ?_⟩
rw [compl_iUnion₂]
exact (countable_bInter_mem htc).mpr (fun i hi ↦ hUl _ (hts _ hi))
| Mathlib/Topology/Compactness/Lindelof.lean | 197 | 199 | theorem IsLindelof.disjoint_nhdsSet_right {l : Filter X} [CountableInterFilter l]
(hs : IsLindelof s) : Disjoint l (𝓝ˢ s) ↔ ∀ x ∈ s, Disjoint l (𝓝 x) := by |
simpa only [disjoint_comm] using hs.disjoint_nhdsSet_left
|
import Mathlib.Data.Set.Function
import Mathlib.Logic.Relation
import Mathlib.Logic.Pairwise
#align_import data.set.pairwise.basic from "leanprover-community/mathlib"@"c4c2ed622f43768eff32608d4a0f8a6cec1c047d"
open Function Order Set
variable {α β γ ι ι' : Type*} {r p q : α → α → Prop}
section Pairwise
variable {f g : ι → α} {s t u : Set α} {a b : α}
theorem pairwise_on_bool (hr : Symmetric r) {a b : α} :
Pairwise (r on fun c => cond c a b) ↔ r a b := by simpa [Pairwise, Function.onFun] using @hr a b
#align pairwise_on_bool pairwise_on_bool
theorem pairwise_disjoint_on_bool [SemilatticeInf α] [OrderBot α] {a b : α} :
Pairwise (Disjoint on fun c => cond c a b) ↔ Disjoint a b :=
pairwise_on_bool Disjoint.symm
#align pairwise_disjoint_on_bool pairwise_disjoint_on_bool
theorem Symmetric.pairwise_on [LinearOrder ι] (hr : Symmetric r) (f : ι → α) :
Pairwise (r on f) ↔ ∀ ⦃m n⦄, m < n → r (f m) (f n) :=
⟨fun h _m _n hmn => h hmn.ne, fun h _m _n hmn => hmn.lt_or_lt.elim (@h _ _) fun h' => hr (h h')⟩
#align symmetric.pairwise_on Symmetric.pairwise_on
theorem pairwise_disjoint_on [SemilatticeInf α] [OrderBot α] [LinearOrder ι] (f : ι → α) :
Pairwise (Disjoint on f) ↔ ∀ ⦃m n⦄, m < n → Disjoint (f m) (f n) :=
Symmetric.pairwise_on Disjoint.symm f
#align pairwise_disjoint_on pairwise_disjoint_on
theorem pairwise_disjoint_mono [SemilatticeInf α] [OrderBot α] (hs : Pairwise (Disjoint on f))
(h : g ≤ f) : Pairwise (Disjoint on g) :=
hs.mono fun i j hij => Disjoint.mono (h i) (h j) hij
#align pairwise_disjoint.mono pairwise_disjoint_mono
namespace Set
theorem Pairwise.mono (h : t ⊆ s) (hs : s.Pairwise r) : t.Pairwise r :=
fun _x xt _y yt => hs (h xt) (h yt)
#align set.pairwise.mono Set.Pairwise.mono
theorem Pairwise.mono' (H : r ≤ p) (hr : s.Pairwise r) : s.Pairwise p :=
hr.imp H
#align set.pairwise.mono' Set.Pairwise.mono'
theorem pairwise_top (s : Set α) : s.Pairwise ⊤ :=
pairwise_of_forall s _ fun _ _ => trivial
#align set.pairwise_top Set.pairwise_top
protected theorem Subsingleton.pairwise (h : s.Subsingleton) (r : α → α → Prop) : s.Pairwise r :=
fun _x hx _y hy hne => (hne (h hx hy)).elim
#align set.subsingleton.pairwise Set.Subsingleton.pairwise
@[simp]
theorem pairwise_empty (r : α → α → Prop) : (∅ : Set α).Pairwise r :=
subsingleton_empty.pairwise r
#align set.pairwise_empty Set.pairwise_empty
@[simp]
theorem pairwise_singleton (a : α) (r : α → α → Prop) : Set.Pairwise {a} r :=
subsingleton_singleton.pairwise r
#align set.pairwise_singleton Set.pairwise_singleton
theorem pairwise_iff_of_refl [IsRefl α r] : s.Pairwise r ↔ ∀ ⦃a⦄, a ∈ s → ∀ ⦃b⦄, b ∈ s → r a b :=
forall₄_congr fun _ _ _ _ => or_iff_not_imp_left.symm.trans <| or_iff_right_of_imp of_eq
#align set.pairwise_iff_of_refl Set.pairwise_iff_of_refl
alias ⟨Pairwise.of_refl, _⟩ := pairwise_iff_of_refl
#align set.pairwise.of_refl Set.Pairwise.of_refl
theorem Nonempty.pairwise_iff_exists_forall [IsEquiv α r] {s : Set ι} (hs : s.Nonempty) :
s.Pairwise (r on f) ↔ ∃ z, ∀ x ∈ s, r (f x) z := by
constructor
· rcases hs with ⟨y, hy⟩
refine fun H => ⟨f y, fun x hx => ?_⟩
rcases eq_or_ne x y with (rfl | hne)
· apply IsRefl.refl
· exact H hx hy hne
· rintro ⟨z, hz⟩ x hx y hy _
exact @IsTrans.trans α r _ (f x) z (f y) (hz _ hx) (IsSymm.symm _ _ <| hz _ hy)
#align set.nonempty.pairwise_iff_exists_forall Set.Nonempty.pairwise_iff_exists_forall
theorem Nonempty.pairwise_eq_iff_exists_eq {s : Set α} (hs : s.Nonempty) {f : α → ι} :
(s.Pairwise fun x y => f x = f y) ↔ ∃ z, ∀ x ∈ s, f x = z :=
hs.pairwise_iff_exists_forall
#align set.nonempty.pairwise_eq_iff_exists_eq Set.Nonempty.pairwise_eq_iff_exists_eq
theorem pairwise_iff_exists_forall [Nonempty ι] (s : Set α) (f : α → ι) {r : ι → ι → Prop}
[IsEquiv ι r] : s.Pairwise (r on f) ↔ ∃ z, ∀ x ∈ s, r (f x) z := by
rcases s.eq_empty_or_nonempty with (rfl | hne)
· simp
· exact hne.pairwise_iff_exists_forall
#align set.pairwise_iff_exists_forall Set.pairwise_iff_exists_forall
theorem pairwise_eq_iff_exists_eq [Nonempty ι] (s : Set α) (f : α → ι) :
(s.Pairwise fun x y => f x = f y) ↔ ∃ z, ∀ x ∈ s, f x = z :=
pairwise_iff_exists_forall s f
#align set.pairwise_eq_iff_exists_eq Set.pairwise_eq_iff_exists_eq
theorem pairwise_union :
(s ∪ t).Pairwise r ↔
s.Pairwise r ∧ t.Pairwise r ∧ ∀ a ∈ s, ∀ b ∈ t, a ≠ b → r a b ∧ r b a := by
simp only [Set.Pairwise, mem_union, or_imp, forall_and]
exact
⟨fun H => ⟨H.1.1, H.2.2, H.1.2, fun x hx y hy hne => H.2.1 y hy x hx hne.symm⟩,
fun H => ⟨⟨H.1, H.2.2.1⟩, fun x hx y hy hne => H.2.2.2 y hy x hx hne.symm, H.2.1⟩⟩
#align set.pairwise_union Set.pairwise_union
theorem pairwise_union_of_symmetric (hr : Symmetric r) :
(s ∪ t).Pairwise r ↔ s.Pairwise r ∧ t.Pairwise r ∧ ∀ a ∈ s, ∀ b ∈ t, a ≠ b → r a b :=
pairwise_union.trans <| by simp only [hr.iff, and_self_iff]
#align set.pairwise_union_of_symmetric Set.pairwise_union_of_symmetric
theorem pairwise_insert :
(insert a s).Pairwise r ↔ s.Pairwise r ∧ ∀ b ∈ s, a ≠ b → r a b ∧ r b a := by
simp only [insert_eq, pairwise_union, pairwise_singleton, true_and_iff, mem_singleton_iff,
forall_eq]
#align set.pairwise_insert Set.pairwise_insert
theorem pairwise_insert_of_not_mem (ha : a ∉ s) :
(insert a s).Pairwise r ↔ s.Pairwise r ∧ ∀ b ∈ s, r a b ∧ r b a :=
pairwise_insert.trans <|
and_congr_right' <| forall₂_congr fun b hb => by simp [(ne_of_mem_of_not_mem hb ha).symm]
#align set.pairwise_insert_of_not_mem Set.pairwise_insert_of_not_mem
protected theorem Pairwise.insert (hs : s.Pairwise r) (h : ∀ b ∈ s, a ≠ b → r a b ∧ r b a) :
(insert a s).Pairwise r :=
pairwise_insert.2 ⟨hs, h⟩
#align set.pairwise.insert Set.Pairwise.insert
theorem Pairwise.insert_of_not_mem (ha : a ∉ s) (hs : s.Pairwise r) (h : ∀ b ∈ s, r a b ∧ r b a) :
(insert a s).Pairwise r :=
(pairwise_insert_of_not_mem ha).2 ⟨hs, h⟩
#align set.pairwise.insert_of_not_mem Set.Pairwise.insert_of_not_mem
theorem pairwise_insert_of_symmetric (hr : Symmetric r) :
(insert a s).Pairwise r ↔ s.Pairwise r ∧ ∀ b ∈ s, a ≠ b → r a b := by
simp only [pairwise_insert, hr.iff a, and_self_iff]
#align set.pairwise_insert_of_symmetric Set.pairwise_insert_of_symmetric
theorem pairwise_insert_of_symmetric_of_not_mem (hr : Symmetric r) (ha : a ∉ s) :
(insert a s).Pairwise r ↔ s.Pairwise r ∧ ∀ b ∈ s, r a b := by
simp only [pairwise_insert_of_not_mem ha, hr.iff a, and_self_iff]
#align set.pairwise_insert_of_symmetric_of_not_mem Set.pairwise_insert_of_symmetric_of_not_mem
theorem Pairwise.insert_of_symmetric (hs : s.Pairwise r) (hr : Symmetric r)
(h : ∀ b ∈ s, a ≠ b → r a b) : (insert a s).Pairwise r :=
(pairwise_insert_of_symmetric hr).2 ⟨hs, h⟩
#align set.pairwise.insert_of_symmetric Set.Pairwise.insert_of_symmetric
theorem Pairwise.insert_of_symmetric_of_not_mem (hs : s.Pairwise r) (hr : Symmetric r) (ha : a ∉ s)
(h : ∀ b ∈ s, r a b) : (insert a s).Pairwise r :=
(pairwise_insert_of_symmetric_of_not_mem hr ha).2 ⟨hs, h⟩
#align set.pairwise.insert_of_symmetric_of_not_mem Set.Pairwise.insert_of_symmetric_of_not_mem
theorem pairwise_pair : Set.Pairwise {a, b} r ↔ a ≠ b → r a b ∧ r b a := by simp [pairwise_insert]
#align set.pairwise_pair Set.pairwise_pair
theorem pairwise_pair_of_symmetric (hr : Symmetric r) : Set.Pairwise {a, b} r ↔ a ≠ b → r a b := by
simp [pairwise_insert_of_symmetric hr]
#align set.pairwise_pair_of_symmetric Set.pairwise_pair_of_symmetric
| Mathlib/Data/Set/Pairwise/Basic.lean | 200 | 201 | theorem pairwise_univ : (univ : Set α).Pairwise r ↔ Pairwise r := by |
simp only [Set.Pairwise, Pairwise, mem_univ, forall_const]
|
import Mathlib.LinearAlgebra.Matrix.ToLin
import Mathlib.LinearAlgebra.Quotient
import Mathlib.RingTheory.Ideal.Maps
import Mathlib.RingTheory.Nilpotent.Defs
#align_import ring_theory.nilpotent from "leanprover-community/mathlib"@"da420a8c6dd5bdfb85c4ced85c34388f633bc6ff"
universe u v
open Function Set
variable {R S : Type*} {x y : R}
theorem RingHom.ker_isRadical_iff_reduced_of_surjective {S F} [CommSemiring R] [CommRing S]
[FunLike F R S] [RingHomClass F R S] {f : F} (hf : Function.Surjective f) :
(RingHom.ker f).IsRadical ↔ IsReduced S := by
simp_rw [isReduced_iff, hf.forall, IsNilpotent, ← map_pow, ← RingHom.mem_ker]
rfl
#align ring_hom.ker_is_radical_iff_reduced_of_surjective RingHom.ker_isRadical_iff_reduced_of_surjective
| Mathlib/RingTheory/Nilpotent/Lemmas.lean | 32 | 35 | theorem isRadical_iff_span_singleton [CommSemiring R] :
IsRadical y ↔ (Ideal.span ({y} : Set R)).IsRadical := by |
simp_rw [IsRadical, ← Ideal.mem_span_singleton]
exact forall_swap.trans (forall_congr' fun r => exists_imp.symm)
|
import Mathlib.Analysis.SpecialFunctions.Pow.Complex
import Qq
#align_import analysis.special_functions.pow.real from "leanprover-community/mathlib"@"4fa54b337f7d52805480306db1b1439c741848c8"
noncomputable section
open scoped Classical
open Real ComplexConjugate
open Finset Set
namespace Real
variable {x y z : ℝ}
noncomputable def rpow (x y : ℝ) :=
((x : ℂ) ^ (y : ℂ)).re
#align real.rpow Real.rpow
noncomputable instance : Pow ℝ ℝ := ⟨rpow⟩
@[simp]
theorem rpow_eq_pow (x y : ℝ) : rpow x y = x ^ y := rfl
#align real.rpow_eq_pow Real.rpow_eq_pow
theorem rpow_def (x y : ℝ) : x ^ y = ((x : ℂ) ^ (y : ℂ)).re := rfl
#align real.rpow_def Real.rpow_def
theorem rpow_def_of_nonneg {x : ℝ} (hx : 0 ≤ x) (y : ℝ) :
x ^ y = if x = 0 then if y = 0 then 1 else 0 else exp (log x * y) := by
simp only [rpow_def, Complex.cpow_def]; split_ifs <;>
simp_all [(Complex.ofReal_log hx).symm, -Complex.ofReal_mul, -RCLike.ofReal_mul,
(Complex.ofReal_mul _ _).symm, Complex.exp_ofReal_re, Complex.ofReal_eq_zero]
#align real.rpow_def_of_nonneg Real.rpow_def_of_nonneg
| Mathlib/Analysis/SpecialFunctions/Pow/Real.lean | 56 | 57 | theorem rpow_def_of_pos {x : ℝ} (hx : 0 < x) (y : ℝ) : x ^ y = exp (log x * y) := by |
rw [rpow_def_of_nonneg (le_of_lt hx), if_neg (ne_of_gt hx)]
|
import Mathlib.Analysis.BoxIntegral.Partition.Split
import Mathlib.Analysis.NormedSpace.OperatorNorm.Mul
#align_import analysis.box_integral.partition.additive from "leanprover-community/mathlib"@"70fd9563a21e7b963887c9360bd29b2393e6225a"
noncomputable section
open scoped Classical
open Function Set
namespace BoxIntegral
variable {ι M : Type*} {n : ℕ}
structure BoxAdditiveMap (ι M : Type*) [AddCommMonoid M] (I : WithTop (Box ι)) where
toFun : Box ι → M
sum_partition_boxes' : ∀ J : Box ι, ↑J ≤ I → ∀ π : Prepartition J, π.IsPartition →
∑ Ji ∈ π.boxes, toFun Ji = toFun J
#align box_integral.box_additive_map BoxIntegral.BoxAdditiveMap
scoped notation:25 ι " →ᵇᵃ " M => BoxIntegral.BoxAdditiveMap ι M ⊤
@[inherit_doc] scoped notation:25 ι " →ᵇᵃ[" I "] " M => BoxIntegral.BoxAdditiveMap ι M I
namespace BoxAdditiveMap
open Box Prepartition Finset
variable {N : Type*} [AddCommMonoid M] [AddCommMonoid N] {I₀ : WithTop (Box ι)} {I J : Box ι}
{i : ι}
instance : FunLike (ι →ᵇᵃ[I₀] M) (Box ι) M where
coe := toFun
coe_injective' f g h := by cases f; cases g; congr
initialize_simps_projections BoxIntegral.BoxAdditiveMap (toFun → apply)
#noalign box_integral.box_additive_map.to_fun_eq_coe
@[simp]
theorem coe_mk (f h) : ⇑(mk f h : ι →ᵇᵃ[I₀] M) = f := rfl
#align box_integral.box_additive_map.coe_mk BoxIntegral.BoxAdditiveMap.coe_mk
theorem coe_injective : Injective fun (f : ι →ᵇᵃ[I₀] M) x => f x :=
DFunLike.coe_injective
#align box_integral.box_additive_map.coe_injective BoxIntegral.BoxAdditiveMap.coe_injective
-- Porting note (#10618): was @[simp], now can be proved by `simp`
theorem coe_inj {f g : ι →ᵇᵃ[I₀] M} : (f : Box ι → M) = g ↔ f = g := DFunLike.coe_fn_eq
#align box_integral.box_additive_map.coe_inj BoxIntegral.BoxAdditiveMap.coe_inj
theorem sum_partition_boxes (f : ι →ᵇᵃ[I₀] M) (hI : ↑I ≤ I₀) {π : Prepartition I}
(h : π.IsPartition) : ∑ J ∈ π.boxes, f J = f I :=
f.sum_partition_boxes' I hI π h
#align box_integral.box_additive_map.sum_partition_boxes BoxIntegral.BoxAdditiveMap.sum_partition_boxes
@[simps (config := .asFn)]
instance : Zero (ι →ᵇᵃ[I₀] M) :=
⟨⟨0, fun _ _ _ _ => sum_const_zero⟩⟩
instance : Inhabited (ι →ᵇᵃ[I₀] M) :=
⟨0⟩
instance : Add (ι →ᵇᵃ[I₀] M) :=
⟨fun f g =>
⟨f + g, fun I hI π hπ => by
simp only [Pi.add_apply, sum_add_distrib, sum_partition_boxes _ hI hπ]⟩⟩
instance {R} [Monoid R] [DistribMulAction R M] : SMul R (ι →ᵇᵃ[I₀] M) :=
⟨fun r f =>
⟨r • (f : Box ι → M), fun I hI π hπ => by
simp only [Pi.smul_apply, ← smul_sum, sum_partition_boxes _ hI hπ]⟩⟩
instance : AddCommMonoid (ι →ᵇᵃ[I₀] M) :=
Function.Injective.addCommMonoid _ coe_injective rfl (fun _ _ => rfl) fun _ _ => rfl
@[simp]
| Mathlib/Analysis/BoxIntegral/Partition/Additive.lean | 113 | 115 | theorem map_split_add (f : ι →ᵇᵃ[I₀] M) (hI : ↑I ≤ I₀) (i : ι) (x : ℝ) :
(I.splitLower i x).elim' 0 f + (I.splitUpper i x).elim' 0 f = f I := by |
rw [← f.sum_partition_boxes hI (isPartitionSplit I i x), sum_split_boxes]
|
import Mathlib.CategoryTheory.Monad.Types
import Mathlib.CategoryTheory.Monad.Limits
import Mathlib.CategoryTheory.Equivalence
import Mathlib.Topology.Category.CompHaus.Basic
import Mathlib.Topology.Category.Profinite.Basic
import Mathlib.Data.Set.Constructions
#align_import topology.category.Compactum from "leanprover-community/mathlib"@"f2ce6086713c78a7f880485f7917ea547a215982"
-- Porting note: "Compactum" is already upper case
set_option linter.uppercaseLean3 false
universe u
open CategoryTheory Filter Ultrafilter TopologicalSpace CategoryTheory.Limits FiniteInter
open scoped Classical
open Topology
local notation "β" => ofTypeMonad Ultrafilter
def Compactum :=
Monad.Algebra β deriving Category, Inhabited
#align Compactum Compactum
namespace Compactum
def forget : Compactum ⥤ Type* :=
Monad.forget _ --deriving CreatesLimits, Faithful
-- Porting note: deriving fails, adding manually. Note `CreatesLimits` now noncomputable
#align Compactum.forget Compactum.forget
instance : forget.Faithful :=
show (Monad.forget _).Faithful from inferInstance
noncomputable instance : CreatesLimits forget :=
show CreatesLimits <| Monad.forget _ from inferInstance
def free : Type* ⥤ Compactum :=
Monad.free _
#align Compactum.free Compactum.free
def adj : free ⊣ forget :=
Monad.adj _
#align Compactum.adj Compactum.adj
-- Basic instances
instance : ConcreteCategory Compactum where forget := forget
-- Porting note: changed from forget to X.A
instance : CoeSort Compactum Type* :=
⟨fun X => X.A⟩
instance {X Y : Compactum} : CoeFun (X ⟶ Y) fun _ => X → Y :=
⟨fun f => f.f⟩
instance : HasLimits Compactum :=
hasLimits_of_hasLimits_createsLimits forget
def str (X : Compactum) : Ultrafilter X → X :=
X.a
#align Compactum.str Compactum.str
def join (X : Compactum) : Ultrafilter (Ultrafilter X) → Ultrafilter X :=
(β ).μ.app _
#align Compactum.join Compactum.join
def incl (X : Compactum) : X → Ultrafilter X :=
(β ).η.app _
#align Compactum.incl Compactum.incl
@[simp]
theorem str_incl (X : Compactum) (x : X) : X.str (X.incl x) = x := by
change ((β ).η.app _ ≫ X.a) _ = _
rw [Monad.Algebra.unit]
rfl
#align Compactum.str_incl Compactum.str_incl
@[simp]
theorem str_hom_commute (X Y : Compactum) (f : X ⟶ Y) (xs : Ultrafilter X) :
f (X.str xs) = Y.str (map f xs) := by
change (X.a ≫ f.f) _ = _
rw [← f.h]
rfl
#align Compactum.str_hom_commute Compactum.str_hom_commute
@[simp]
theorem join_distrib (X : Compactum) (uux : Ultrafilter (Ultrafilter X)) :
X.str (X.join uux) = X.str (map X.str uux) := by
change ((β ).μ.app _ ≫ X.a) _ = _
rw [Monad.Algebra.assoc]
rfl
#align Compactum.join_distrib Compactum.join_distrib
-- Porting note: changes to X.A from X since Lean can't see through X to X.A below
instance {X : Compactum} : TopologicalSpace X.A where
IsOpen U := ∀ F : Ultrafilter X, X.str F ∈ U → U ∈ F
isOpen_univ _ _ := Filter.univ_sets _
isOpen_inter _ _ h3 h4 _ h6 := Filter.inter_sets _ (h3 _ h6.1) (h4 _ h6.2)
isOpen_sUnion := fun _ h1 _ ⟨T, hT, h2⟩ =>
mem_of_superset (h1 T hT _ h2) (Set.subset_sUnion_of_mem hT)
theorem isClosed_iff {X : Compactum} (S : Set X) :
IsClosed S ↔ ∀ F : Ultrafilter X, S ∈ F → X.str F ∈ S := by
rw [← isOpen_compl_iff]
constructor
· intro cond F h
by_contra c
specialize cond F c
rw [compl_mem_iff_not_mem] at cond
contradiction
· intro h1 F h2
specialize h1 F
cases' F.mem_or_compl_mem S with h h
exacts [absurd (h1 h) h2, h]
#align Compactum.is_closed_iff Compactum.isClosed_iff
instance {X : Compactum} : CompactSpace X := by
constructor
rw [isCompact_iff_ultrafilter_le_nhds]
intro F _
refine ⟨X.str F, by tauto, ?_⟩
rw [le_nhds_iff]
intro S h1 h2
exact h2 F h1
private def basic {X : Compactum} (A : Set X) : Set (Ultrafilter X) :=
{ F | A ∈ F }
private def cl {X : Compactum} (A : Set X) : Set X :=
X.str '' basic A
private theorem basic_inter {X : Compactum} (A B : Set X) : basic (A ∩ B) = basic A ∩ basic B := by
ext G
constructor
· intro hG
constructor <;> filter_upwards [hG] with _
exacts [And.left, And.right]
· rintro ⟨h1, h2⟩
exact inter_mem h1 h2
private theorem subset_cl {X : Compactum} (A : Set X) : A ⊆ cl A := fun a ha =>
⟨X.incl a, ha, by simp⟩
private theorem cl_cl {X : Compactum} (A : Set X) : cl (cl A) ⊆ cl A := by
rintro _ ⟨F, hF, rfl⟩
-- Notation to be used in this proof.
let fsu := Finset (Set (Ultrafilter X))
let ssu := Set (Set (Ultrafilter X))
let ι : fsu → ssu := fun x ↦ ↑x
let C0 : ssu := { Z | ∃ B ∈ F, X.str ⁻¹' B = Z }
let AA := { G : Ultrafilter X | A ∈ G }
let C1 := insert AA C0
let C2 := finiteInterClosure C1
-- C0 is closed under intersections.
have claim1 : ∀ (B) (_ : B ∈ C0) (C) (_ : C ∈ C0), B ∩ C ∈ C0 := by
rintro B ⟨Q, hQ, rfl⟩ C ⟨R, hR, rfl⟩
use Q ∩ R
simp only [and_true_iff, eq_self_iff_true, Set.preimage_inter]
exact inter_sets _ hQ hR
-- All sets in C0 are nonempty.
have claim2 : ∀ B ∈ C0, Set.Nonempty B := by
rintro B ⟨Q, hQ, rfl⟩
obtain ⟨q⟩ := Filter.nonempty_of_mem hQ
use X.incl q
simpa
-- The intersection of AA with every set in C0 is nonempty.
have claim3 : ∀ B ∈ C0, (AA ∩ B).Nonempty := by
rintro B ⟨Q, hQ, rfl⟩
have : (Q ∩ cl A).Nonempty := Filter.nonempty_of_mem (inter_mem hQ hF)
rcases this with ⟨q, hq1, P, hq2, hq3⟩
refine ⟨P, hq2, ?_⟩
rw [← hq3] at hq1
simpa
-- Suffices to show that the intersection of any finite subcollection of C1 is nonempty.
suffices ∀ T : fsu, ι T ⊆ C1 → (⋂₀ ι T).Nonempty by
obtain ⟨G, h1⟩ := exists_ultrafilter_of_finite_inter_nonempty _ this
use X.join G
have : G.map X.str = F := Ultrafilter.coe_le_coe.1 fun S hS => h1 (Or.inr ⟨S, hS, rfl⟩)
rw [join_distrib, this]
exact ⟨h1 (Or.inl rfl), rfl⟩
-- C2 is closed under finite intersections (by construction!).
have claim4 := finiteInterClosure_finiteInter C1
-- C0 is closed under finite intersections by claim1.
have claim5 : FiniteInter C0 := ⟨⟨_, univ_mem, Set.preimage_univ⟩, claim1⟩
-- Every element of C2 is nonempty.
have claim6 : ∀ P ∈ C2, (P : Set (Ultrafilter X)).Nonempty := by
suffices ∀ P ∈ C2, P ∈ C0 ∨ ∃ Q ∈ C0, P = AA ∩ Q by
intro P hP
cases' this P hP with h h
· exact claim2 _ h
· rcases h with ⟨Q, hQ, rfl⟩
exact claim3 _ hQ
intro P hP
exact claim5.finiteInterClosure_insert _ hP
intro T hT
-- Suffices to show that the intersection of the T's is contained in C2.
suffices ⋂₀ ι T ∈ C2 by exact claim6 _ this
-- Finish
apply claim4.finiteInter_mem T
intro t ht
exact finiteInterClosure.basic (@hT t ht)
| Mathlib/Topology/Category/Compactum.lean | 276 | 279 | theorem isClosed_cl {X : Compactum} (A : Set X) : IsClosed (cl A) := by |
rw [isClosed_iff]
intro F hF
exact cl_cl _ ⟨F, hF, rfl⟩
|
import Mathlib.Algebra.Group.Subgroup.Basic
import Mathlib.Algebra.Module.Defs
import Mathlib.Algebra.Star.Pi
#align_import algebra.star.self_adjoint from "leanprover-community/mathlib"@"a6ece35404f60597c651689c1b46ead86de5ac1b"
open Function
variable {R A : Type*}
def IsSelfAdjoint [Star R] (x : R) : Prop :=
star x = x
#align is_self_adjoint IsSelfAdjoint
@[mk_iff]
class IsStarNormal [Mul R] [Star R] (x : R) : Prop where
star_comm_self : Commute (star x) x
#align is_star_normal IsStarNormal
export IsStarNormal (star_comm_self)
theorem star_comm_self' [Mul R] [Star R] (x : R) [IsStarNormal x] : star x * x = x * star x :=
IsStarNormal.star_comm_self
#align star_comm_self' star_comm_self'
namespace IsSelfAdjoint
-- named to match `Commute.allₓ`
theorem all [Star R] [TrivialStar R] (r : R) : IsSelfAdjoint r :=
star_trivial _
#align is_self_adjoint.all IsSelfAdjoint.all
theorem star_eq [Star R] {x : R} (hx : IsSelfAdjoint x) : star x = x :=
hx
#align is_self_adjoint.star_eq IsSelfAdjoint.star_eq
theorem _root_.isSelfAdjoint_iff [Star R] {x : R} : IsSelfAdjoint x ↔ star x = x :=
Iff.rfl
#align is_self_adjoint_iff isSelfAdjoint_iff
@[simp]
theorem star_iff [InvolutiveStar R] {x : R} : IsSelfAdjoint (star x) ↔ IsSelfAdjoint x := by
simpa only [IsSelfAdjoint, star_star] using eq_comm
#align is_self_adjoint.star_iff IsSelfAdjoint.star_iff
@[simp]
theorem star_mul_self [Mul R] [StarMul R] (x : R) : IsSelfAdjoint (star x * x) := by
simp only [IsSelfAdjoint, star_mul, star_star]
#align is_self_adjoint.star_mul_self IsSelfAdjoint.star_mul_self
@[simp]
theorem mul_star_self [Mul R] [StarMul R] (x : R) : IsSelfAdjoint (x * star x) := by
simpa only [star_star] using star_mul_self (star x)
#align is_self_adjoint.mul_star_self IsSelfAdjoint.mul_star_self
lemma commute_iff {R : Type*} [Mul R] [StarMul R] {x y : R}
(hx : IsSelfAdjoint x) (hy : IsSelfAdjoint y) : Commute x y ↔ IsSelfAdjoint (x * y) := by
refine ⟨fun h ↦ ?_, fun h ↦ ?_⟩
· rw [isSelfAdjoint_iff, star_mul, hx.star_eq, hy.star_eq, h.eq]
· simpa only [star_mul, hx.star_eq, hy.star_eq] using h.symm
theorem starHom_apply {F R S : Type*} [Star R] [Star S] [FunLike F R S] [StarHomClass F R S]
{x : R} (hx : IsSelfAdjoint x) (f : F) : IsSelfAdjoint (f x) :=
show star (f x) = f x from map_star f x ▸ congr_arg f hx
#align is_self_adjoint.star_hom_apply IsSelfAdjoint.starHom_apply
theorem _root_.isSelfAdjoint_starHom_apply {F R S : Type*} [Star R] [Star S] [FunLike F R S]
[StarHomClass F R S] [TrivialStar R] (f : F) (x : R) : IsSelfAdjoint (f x) :=
(IsSelfAdjoint.all x).starHom_apply f
section DivisionSemiring
variable [DivisionSemiring R] [StarRing R]
theorem inv {x : R} (hx : IsSelfAdjoint x) : IsSelfAdjoint x⁻¹ := by
simp only [isSelfAdjoint_iff, star_inv', hx.star_eq]
#align is_self_adjoint.inv IsSelfAdjoint.inv
| Mathlib/Algebra/Star/SelfAdjoint.lean | 258 | 259 | theorem zpow {x : R} (hx : IsSelfAdjoint x) (n : ℤ) : IsSelfAdjoint (x ^ n) := by |
simp only [isSelfAdjoint_iff, star_zpow₀, hx.star_eq]
|
import Mathlib.SetTheory.Ordinal.FixedPoint
#align_import set_theory.ordinal.principal from "leanprover-community/mathlib"@"31b269b60935483943542d547a6dd83a66b37dc7"
universe u v w
noncomputable section
open Order
namespace Ordinal
-- Porting note: commented out, doesn't seem necessary
--local infixr:0 "^" => @pow Ordinal Ordinal Ordinal.hasPow
def Principal (op : Ordinal → Ordinal → Ordinal) (o : Ordinal) : Prop :=
∀ ⦃a b⦄, a < o → b < o → op a b < o
#align ordinal.principal Ordinal.Principal
theorem principal_iff_principal_swap {op : Ordinal → Ordinal → Ordinal} {o : Ordinal} :
Principal op o ↔ Principal (Function.swap op) o := by
constructor <;> exact fun h a b ha hb => h hb ha
#align ordinal.principal_iff_principal_swap Ordinal.principal_iff_principal_swap
theorem principal_zero {op : Ordinal → Ordinal → Ordinal} : Principal op 0 := fun a _ h =>
(Ordinal.not_lt_zero a h).elim
#align ordinal.principal_zero Ordinal.principal_zero
@[simp]
theorem principal_one_iff {op : Ordinal → Ordinal → Ordinal} : Principal op 1 ↔ op 0 0 = 0 := by
refine ⟨fun h => ?_, fun h a b ha hb => ?_⟩
· rw [← lt_one_iff_zero]
exact h zero_lt_one zero_lt_one
· rwa [lt_one_iff_zero, ha, hb] at *
#align ordinal.principal_one_iff Ordinal.principal_one_iff
theorem Principal.iterate_lt {op : Ordinal → Ordinal → Ordinal} {a o : Ordinal} (hao : a < o)
(ho : Principal op o) (n : ℕ) : (op a)^[n] a < o := by
induction' n with n hn
· rwa [Function.iterate_zero]
· rw [Function.iterate_succ']
exact ho hao hn
#align ordinal.principal.iterate_lt Ordinal.Principal.iterate_lt
| Mathlib/SetTheory/Ordinal/Principal.lean | 77 | 81 | theorem op_eq_self_of_principal {op : Ordinal → Ordinal → Ordinal} {a o : Ordinal.{u}} (hao : a < o)
(H : IsNormal (op a)) (ho : Principal op o) (ho' : IsLimit o) : op a o = o := by |
refine le_antisymm ?_ (H.self_le _)
rw [← IsNormal.bsup_eq.{u, u} H ho', bsup_le_iff]
exact fun b hbo => (ho hao hbo).le
|
import Mathlib.MeasureTheory.Integral.Lebesgue
import Mathlib.Analysis.MeanInequalities
import Mathlib.Analysis.MeanInequalitiesPow
import Mathlib.MeasureTheory.Function.SpecialFunctions.Basic
#align_import measure_theory.integral.mean_inequalities from "leanprover-community/mathlib"@"13bf7613c96a9fd66a81b9020a82cad9a6ea1fcf"
section LIntegral
noncomputable section
open scoped Classical
open NNReal ENNReal MeasureTheory Finset
set_option linter.uppercaseLean3 false
variable {α : Type*} [MeasurableSpace α] {μ : Measure α}
namespace ENNReal
theorem lintegral_mul_le_one_of_lintegral_rpow_eq_one {p q : ℝ} (hpq : p.IsConjExponent q)
{f g : α → ℝ≥0∞} (hf : AEMeasurable f μ) (hf_norm : ∫⁻ a, f a ^ p ∂μ = 1)
(hg_norm : ∫⁻ a, g a ^ q ∂μ = 1) : (∫⁻ a, (f * g) a ∂μ) ≤ 1 := by
calc
(∫⁻ a : α, (f * g) a ∂μ) ≤
∫⁻ a : α, f a ^ p / ENNReal.ofReal p + g a ^ q / ENNReal.ofReal q ∂μ :=
lintegral_mono fun a => young_inequality (f a) (g a) hpq
_ = 1 := by
simp only [div_eq_mul_inv]
rw [lintegral_add_left']
· rw [lintegral_mul_const'' _ (hf.pow_const p), lintegral_mul_const', hf_norm, hg_norm,
one_mul, one_mul, hpq.inv_add_inv_conj_ennreal]
simp [hpq.symm.pos]
· exact (hf.pow_const _).mul_const _
#align ennreal.lintegral_mul_le_one_of_lintegral_rpow_eq_one ENNReal.lintegral_mul_le_one_of_lintegral_rpow_eq_one
def funMulInvSnorm (f : α → ℝ≥0∞) (p : ℝ) (μ : Measure α) : α → ℝ≥0∞ := fun a =>
f a * ((∫⁻ c, f c ^ p ∂μ) ^ (1 / p))⁻¹
#align ennreal.fun_mul_inv_snorm ENNReal.funMulInvSnorm
theorem fun_eq_funMulInvSnorm_mul_snorm {p : ℝ} (f : α → ℝ≥0∞) (hf_nonzero : (∫⁻ a, f a ^ p ∂μ) ≠ 0)
(hf_top : (∫⁻ a, f a ^ p ∂μ) ≠ ⊤) {a : α} :
f a = funMulInvSnorm f p μ a * (∫⁻ c, f c ^ p ∂μ) ^ (1 / p) := by
simp [funMulInvSnorm, mul_assoc, ENNReal.inv_mul_cancel, hf_nonzero, hf_top]
#align ennreal.fun_eq_fun_mul_inv_snorm_mul_snorm ENNReal.fun_eq_funMulInvSnorm_mul_snorm
theorem funMulInvSnorm_rpow {p : ℝ} (hp0 : 0 < p) {f : α → ℝ≥0∞} {a : α} :
funMulInvSnorm f p μ a ^ p = f a ^ p * (∫⁻ c, f c ^ p ∂μ)⁻¹ := by
rw [funMulInvSnorm, mul_rpow_of_nonneg _ _ (le_of_lt hp0)]
suffices h_inv_rpow : ((∫⁻ c : α, f c ^ p ∂μ) ^ (1 / p))⁻¹ ^ p = (∫⁻ c : α, f c ^ p ∂μ)⁻¹ by
rw [h_inv_rpow]
rw [inv_rpow, ← rpow_mul, one_div_mul_cancel hp0.ne', rpow_one]
#align ennreal.fun_mul_inv_snorm_rpow ENNReal.funMulInvSnorm_rpow
theorem lintegral_rpow_funMulInvSnorm_eq_one {p : ℝ} (hp0_lt : 0 < p) {f : α → ℝ≥0∞}
(hf_nonzero : (∫⁻ a, f a ^ p ∂μ) ≠ 0) (hf_top : (∫⁻ a, f a ^ p ∂μ) ≠ ⊤) :
∫⁻ c, funMulInvSnorm f p μ c ^ p ∂μ = 1 := by
simp_rw [funMulInvSnorm_rpow hp0_lt]
rw [lintegral_mul_const', ENNReal.mul_inv_cancel hf_nonzero hf_top]
rwa [inv_ne_top]
#align ennreal.lintegral_rpow_fun_mul_inv_snorm_eq_one ENNReal.lintegral_rpow_funMulInvSnorm_eq_one
theorem lintegral_mul_le_Lp_mul_Lq_of_ne_zero_of_ne_top {p q : ℝ} (hpq : p.IsConjExponent q)
{f g : α → ℝ≥0∞} (hf : AEMeasurable f μ) (hf_nontop : (∫⁻ a, f a ^ p ∂μ) ≠ ⊤)
(hg_nontop : (∫⁻ a, g a ^ q ∂μ) ≠ ⊤) (hf_nonzero : (∫⁻ a, f a ^ p ∂μ) ≠ 0)
(hg_nonzero : (∫⁻ a, g a ^ q ∂μ) ≠ 0) :
(∫⁻ a, (f * g) a ∂μ) ≤ (∫⁻ a, f a ^ p ∂μ) ^ (1 / p) * (∫⁻ a, g a ^ q ∂μ) ^ (1 / q) := by
let npf := (∫⁻ c : α, f c ^ p ∂μ) ^ (1 / p)
let nqg := (∫⁻ c : α, g c ^ q ∂μ) ^ (1 / q)
calc
(∫⁻ a : α, (f * g) a ∂μ) =
∫⁻ a : α, (funMulInvSnorm f p μ * funMulInvSnorm g q μ) a * (npf * nqg) ∂μ := by
refine lintegral_congr fun a => ?_
rw [Pi.mul_apply, fun_eq_funMulInvSnorm_mul_snorm f hf_nonzero hf_nontop,
fun_eq_funMulInvSnorm_mul_snorm g hg_nonzero hg_nontop, Pi.mul_apply]
ring
_ ≤ npf * nqg := by
rw [lintegral_mul_const' (npf * nqg) _
(by simp [npf, nqg, hf_nontop, hg_nontop, hf_nonzero, hg_nonzero, ENNReal.mul_eq_top])]
refine mul_le_of_le_one_left' ?_
have hf1 := lintegral_rpow_funMulInvSnorm_eq_one hpq.pos hf_nonzero hf_nontop
have hg1 := lintegral_rpow_funMulInvSnorm_eq_one hpq.symm.pos hg_nonzero hg_nontop
exact lintegral_mul_le_one_of_lintegral_rpow_eq_one hpq (hf.mul_const _) hf1 hg1
#align ennreal.lintegral_mul_le_Lp_mul_Lq_of_ne_zero_of_ne_top ENNReal.lintegral_mul_le_Lp_mul_Lq_of_ne_zero_of_ne_top
theorem ae_eq_zero_of_lintegral_rpow_eq_zero {p : ℝ} (hp0 : 0 ≤ p) {f : α → ℝ≥0∞}
(hf : AEMeasurable f μ) (hf_zero : ∫⁻ a, f a ^ p ∂μ = 0) : f =ᵐ[μ] 0 := by
rw [lintegral_eq_zero_iff' (hf.pow_const p)] at hf_zero
filter_upwards [hf_zero] with x
rw [Pi.zero_apply, ← not_imp_not]
exact fun hx => (rpow_pos_of_nonneg (pos_iff_ne_zero.2 hx) hp0).ne'
#align ennreal.ae_eq_zero_of_lintegral_rpow_eq_zero ENNReal.ae_eq_zero_of_lintegral_rpow_eq_zero
theorem lintegral_mul_eq_zero_of_lintegral_rpow_eq_zero {p : ℝ} (hp0 : 0 ≤ p) {f g : α → ℝ≥0∞}
(hf : AEMeasurable f μ) (hf_zero : ∫⁻ a, f a ^ p ∂μ = 0) : (∫⁻ a, (f * g) a ∂μ) = 0 := by
rw [← @lintegral_zero_fun α _ μ]
refine lintegral_congr_ae ?_
suffices h_mul_zero : f * g =ᵐ[μ] 0 * g by rwa [zero_mul] at h_mul_zero
have hf_eq_zero : f =ᵐ[μ] 0 := ae_eq_zero_of_lintegral_rpow_eq_zero hp0 hf hf_zero
exact hf_eq_zero.mul (ae_eq_refl g)
#align ennreal.lintegral_mul_eq_zero_of_lintegral_rpow_eq_zero ENNReal.lintegral_mul_eq_zero_of_lintegral_rpow_eq_zero
| Mathlib/MeasureTheory/Integral/MeanInequalities.lean | 150 | 156 | theorem lintegral_mul_le_Lp_mul_Lq_of_ne_zero_of_eq_top {p q : ℝ} (hp0_lt : 0 < p) (hq0 : 0 ≤ q)
{f g : α → ℝ≥0∞} (hf_top : ∫⁻ a, f a ^ p ∂μ = ⊤) (hg_nonzero : (∫⁻ a, g a ^ q ∂μ) ≠ 0) :
(∫⁻ a, (f * g) a ∂μ) ≤ (∫⁻ a, f a ^ p ∂μ) ^ (1 / p) * (∫⁻ a, g a ^ q ∂μ) ^ (1 / q) := by |
refine le_trans le_top (le_of_eq ?_)
have hp0_inv_lt : 0 < 1 / p := by simp [hp0_lt]
rw [hf_top, ENNReal.top_rpow_of_pos hp0_inv_lt]
simp [hq0, hg_nonzero]
|
import Mathlib.Topology.Basic
#align_import topology.nhds_set from "leanprover-community/mathlib"@"f2ce6086713c78a7f880485f7917ea547a215982"
open Set Filter Topology
variable {X Y : Type*} [TopologicalSpace X] [TopologicalSpace Y] {f : Filter X}
{s t s₁ s₂ t₁ t₂ : Set X} {x : X}
theorem nhdsSet_diagonal (X) [TopologicalSpace (X × X)] :
𝓝ˢ (diagonal X) = ⨆ (x : X), 𝓝 (x, x) := by
rw [nhdsSet, ← range_diag, ← range_comp]
rfl
#align nhds_set_diagonal nhdsSet_diagonal
theorem mem_nhdsSet_iff_forall : s ∈ 𝓝ˢ t ↔ ∀ x : X, x ∈ t → s ∈ 𝓝 x := by
simp_rw [nhdsSet, Filter.mem_sSup, forall_mem_image]
#align mem_nhds_set_iff_forall mem_nhdsSet_iff_forall
lemma nhdsSet_le : 𝓝ˢ s ≤ f ↔ ∀ x ∈ s, 𝓝 x ≤ f := by simp [nhdsSet]
theorem bUnion_mem_nhdsSet {t : X → Set X} (h : ∀ x ∈ s, t x ∈ 𝓝 x) : (⋃ x ∈ s, t x) ∈ 𝓝ˢ s :=
mem_nhdsSet_iff_forall.2 fun x hx => mem_of_superset (h x hx) <|
subset_iUnion₂ (s := fun x _ => t x) x hx -- Porting note: fails to find `s`
#align bUnion_mem_nhds_set bUnion_mem_nhdsSet
theorem subset_interior_iff_mem_nhdsSet : s ⊆ interior t ↔ t ∈ 𝓝ˢ s := by
simp_rw [mem_nhdsSet_iff_forall, subset_interior_iff_nhds]
#align subset_interior_iff_mem_nhds_set subset_interior_iff_mem_nhdsSet
theorem disjoint_principal_nhdsSet : Disjoint (𝓟 s) (𝓝ˢ t) ↔ Disjoint (closure s) t := by
rw [disjoint_principal_left, ← subset_interior_iff_mem_nhdsSet, interior_compl,
subset_compl_iff_disjoint_left]
theorem disjoint_nhdsSet_principal : Disjoint (𝓝ˢ s) (𝓟 t) ↔ Disjoint s (closure t) := by
rw [disjoint_comm, disjoint_principal_nhdsSet, disjoint_comm]
theorem mem_nhdsSet_iff_exists : s ∈ 𝓝ˢ t ↔ ∃ U : Set X, IsOpen U ∧ t ⊆ U ∧ U ⊆ s := by
rw [← subset_interior_iff_mem_nhdsSet, subset_interior_iff]
#align mem_nhds_set_iff_exists mem_nhdsSet_iff_exists
theorem eventually_nhdsSet_iff_exists {p : X → Prop} :
(∀ᶠ x in 𝓝ˢ s, p x) ↔ ∃ t, IsOpen t ∧ s ⊆ t ∧ ∀ x, x ∈ t → p x :=
mem_nhdsSet_iff_exists
theorem eventually_nhdsSet_iff_forall {p : X → Prop} :
(∀ᶠ x in 𝓝ˢ s, p x) ↔ ∀ x, x ∈ s → ∀ᶠ y in 𝓝 x, p y :=
mem_nhdsSet_iff_forall
theorem hasBasis_nhdsSet (s : Set X) : (𝓝ˢ s).HasBasis (fun U => IsOpen U ∧ s ⊆ U) fun U => U :=
⟨fun t => by simp [mem_nhdsSet_iff_exists, and_assoc]⟩
#align has_basis_nhds_set hasBasis_nhdsSet
@[simp]
lemma lift'_nhdsSet_interior (s : Set X) : (𝓝ˢ s).lift' interior = 𝓝ˢ s :=
(hasBasis_nhdsSet s).lift'_interior_eq_self fun _ ↦ And.left
lemma Filter.HasBasis.nhdsSet_interior {ι : Sort*} {p : ι → Prop} {s : ι → Set X} {t : Set X}
(h : (𝓝ˢ t).HasBasis p s) : (𝓝ˢ t).HasBasis p (interior <| s ·) :=
lift'_nhdsSet_interior t ▸ h.lift'_interior
theorem IsOpen.mem_nhdsSet (hU : IsOpen s) : s ∈ 𝓝ˢ t ↔ t ⊆ s := by
rw [← subset_interior_iff_mem_nhdsSet, hU.interior_eq]
#align is_open.mem_nhds_set IsOpen.mem_nhdsSet
theorem IsOpen.mem_nhdsSet_self (ho : IsOpen s) : s ∈ 𝓝ˢ s := ho.mem_nhdsSet.mpr Subset.rfl
theorem principal_le_nhdsSet : 𝓟 s ≤ 𝓝ˢ s := fun _s hs =>
(subset_interior_iff_mem_nhdsSet.mpr hs).trans interior_subset
#align principal_le_nhds_set principal_le_nhdsSet
theorem subset_of_mem_nhdsSet (h : t ∈ 𝓝ˢ s) : s ⊆ t := principal_le_nhdsSet h
theorem Filter.Eventually.self_of_nhdsSet {p : X → Prop} (h : ∀ᶠ x in 𝓝ˢ s, p x) : ∀ x ∈ s, p x :=
principal_le_nhdsSet h
nonrec theorem Filter.EventuallyEq.self_of_nhdsSet {f g : X → Y} (h : f =ᶠ[𝓝ˢ s] g) : EqOn f g s :=
h.self_of_nhdsSet
@[simp]
theorem nhdsSet_eq_principal_iff : 𝓝ˢ s = 𝓟 s ↔ IsOpen s := by
rw [← principal_le_nhdsSet.le_iff_eq, le_principal_iff, mem_nhdsSet_iff_forall,
isOpen_iff_mem_nhds]
#align nhds_set_eq_principal_iff nhdsSet_eq_principal_iff
alias ⟨_, IsOpen.nhdsSet_eq⟩ := nhdsSet_eq_principal_iff
#align is_open.nhds_set_eq IsOpen.nhdsSet_eq
@[simp]
theorem nhdsSet_interior : 𝓝ˢ (interior s) = 𝓟 (interior s) :=
isOpen_interior.nhdsSet_eq
#align nhds_set_interior nhdsSet_interior
@[simp]
theorem nhdsSet_singleton : 𝓝ˢ {x} = 𝓝 x := by simp [nhdsSet]
#align nhds_set_singleton nhdsSet_singleton
theorem mem_nhdsSet_interior : s ∈ 𝓝ˢ (interior s) :=
subset_interior_iff_mem_nhdsSet.mp Subset.rfl
#align mem_nhds_set_interior mem_nhdsSet_interior
@[simp]
theorem nhdsSet_empty : 𝓝ˢ (∅ : Set X) = ⊥ := by rw [isOpen_empty.nhdsSet_eq, principal_empty]
#align nhds_set_empty nhdsSet_empty
theorem mem_nhdsSet_empty : s ∈ 𝓝ˢ (∅ : Set X) := by simp
#align mem_nhds_set_empty mem_nhdsSet_empty
@[simp]
theorem nhdsSet_univ : 𝓝ˢ (univ : Set X) = ⊤ := by rw [isOpen_univ.nhdsSet_eq, principal_univ]
#align nhds_set_univ nhdsSet_univ
@[mono]
theorem nhdsSet_mono (h : s ⊆ t) : 𝓝ˢ s ≤ 𝓝ˢ t :=
sSup_le_sSup <| image_subset _ h
#align nhds_set_mono nhdsSet_mono
theorem monotone_nhdsSet : Monotone (𝓝ˢ : Set X → Filter X) := fun _ _ => nhdsSet_mono
#align monotone_nhds_set monotone_nhdsSet
theorem nhds_le_nhdsSet (h : x ∈ s) : 𝓝 x ≤ 𝓝ˢ s :=
le_sSup <| mem_image_of_mem _ h
#align nhds_le_nhds_set nhds_le_nhdsSet
@[simp]
theorem nhdsSet_union (s t : Set X) : 𝓝ˢ (s ∪ t) = 𝓝ˢ s ⊔ 𝓝ˢ t := by
simp only [nhdsSet, image_union, sSup_union]
#align nhds_set_union nhdsSet_union
theorem union_mem_nhdsSet (h₁ : s₁ ∈ 𝓝ˢ t₁) (h₂ : s₂ ∈ 𝓝ˢ t₂) : s₁ ∪ s₂ ∈ 𝓝ˢ (t₁ ∪ t₂) := by
rw [nhdsSet_union]
exact union_mem_sup h₁ h₂
#align union_mem_nhds_set union_mem_nhdsSet
@[simp]
| Mathlib/Topology/NhdsSet.lean | 165 | 166 | theorem nhdsSet_insert (x : X) (s : Set X) : 𝓝ˢ (insert x s) = 𝓝 x ⊔ 𝓝ˢ s := by |
rw [insert_eq, nhdsSet_union, nhdsSet_singleton]
|
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
| Mathlib/MeasureTheory/Integral/Lebesgue.lean | 309 | 310 | 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]
|
import Mathlib.Logic.Function.Basic
import Mathlib.Tactic.MkIffOfInductiveProp
#align_import data.sum.basic from "leanprover-community/mathlib"@"bd9851ca476957ea4549eb19b40e7b5ade9428cc"
universe u v w x
variable {α : Type u} {α' : Type w} {β : Type v} {β' : Type x} {γ δ : Type*}
namespace Sum
#align sum.forall Sum.forall
#align sum.exists Sum.exists
theorem exists_sum {γ : α ⊕ β → Sort*} (p : (∀ ab, γ ab) → Prop) :
(∃ fab, p fab) ↔ (∃ fa fb, p (Sum.rec fa fb)) := by
rw [← not_forall_not, forall_sum]
simp
theorem inl_injective : Function.Injective (inl : α → Sum α β) := fun _ _ ↦ inl.inj
#align sum.inl_injective Sum.inl_injective
theorem inr_injective : Function.Injective (inr : β → Sum α β) := fun _ _ ↦ inr.inj
#align sum.inr_injective Sum.inr_injective
theorem sum_rec_congr (P : α ⊕ β → Sort*) (f : ∀ i, P (inl i)) (g : ∀ i, P (inr i))
{x y : α ⊕ β} (h : x = y) :
@Sum.rec _ _ _ f g x = cast (congr_arg P h.symm) (@Sum.rec _ _ _ f g y) := by cases h; rfl
#align sum.inl.inj_iff Sum.inl.inj_iff
#align sum.inr.inj_iff Sum.inr.inj_iff
#align sum.inl_ne_inr Sum.inl_ne_inr
#align sum.inr_ne_inl Sum.inr_ne_inl
#align sum.elim Sum.elim
#align sum.elim_inl Sum.elim_inl
#align sum.elim_inr Sum.elim_inr
#align sum.elim_comp_inl Sum.elim_comp_inl
#align sum.elim_comp_inr Sum.elim_comp_inr
#align sum.elim_inl_inr Sum.elim_inl_inr
#align sum.comp_elim Sum.comp_elim
#align sum.elim_comp_inl_inr Sum.elim_comp_inl_inr
#align sum.map Sum.map
#align sum.map_inl Sum.map_inl
#align sum.map_inr Sum.map_inr
#align sum.map_map Sum.map_map
#align sum.map_comp_map Sum.map_comp_map
#align sum.map_id_id Sum.map_id_id
#align sum.elim_map Sum.elim_map
#align sum.elim_comp_map Sum.elim_comp_map
#align sum.is_left_map Sum.isLeft_map
#align sum.is_right_map Sum.isRight_map
#align sum.get_left_map Sum.getLeft?_map
#align sum.get_right_map Sum.getRight?_map
open Function (update update_eq_iff update_comp_eq_of_injective update_comp_eq_of_forall_ne)
@[simp]
theorem update_elim_inl [DecidableEq α] [DecidableEq (Sum α β)] {f : α → γ} {g : β → γ} {i : α}
{x : γ} : update (Sum.elim f g) (inl i) x = Sum.elim (update f i x) g :=
update_eq_iff.2 ⟨by simp, by simp (config := { contextual := true })⟩
#align sum.update_elim_inl Sum.update_elim_inl
@[simp]
theorem update_elim_inr [DecidableEq β] [DecidableEq (Sum α β)] {f : α → γ} {g : β → γ} {i : β}
{x : γ} : update (Sum.elim f g) (inr i) x = Sum.elim f (update g i x) :=
update_eq_iff.2 ⟨by simp, by simp (config := { contextual := true })⟩
#align sum.update_elim_inr Sum.update_elim_inr
@[simp]
theorem update_inl_comp_inl [DecidableEq α] [DecidableEq (Sum α β)] {f : Sum α β → γ} {i : α}
{x : γ} : update f (inl i) x ∘ inl = update (f ∘ inl) i x :=
update_comp_eq_of_injective _ inl_injective _ _
#align sum.update_inl_comp_inl Sum.update_inl_comp_inl
@[simp]
theorem update_inl_apply_inl [DecidableEq α] [DecidableEq (Sum α β)] {f : Sum α β → γ} {i j : α}
{x : γ} : update f (inl i) x (inl j) = update (f ∘ inl) i x j := by
rw [← update_inl_comp_inl, Function.comp_apply]
#align sum.update_inl_apply_inl Sum.update_inl_apply_inl
@[simp]
theorem update_inl_comp_inr [DecidableEq (Sum α β)] {f : Sum α β → γ} {i : α} {x : γ} :
update f (inl i) x ∘ inr = f ∘ inr :=
(update_comp_eq_of_forall_ne _ _) fun _ ↦ inr_ne_inl
#align sum.update_inl_comp_inr Sum.update_inl_comp_inr
theorem update_inl_apply_inr [DecidableEq (Sum α β)] {f : Sum α β → γ} {i : α} {j : β} {x : γ} :
update f (inl i) x (inr j) = f (inr j) :=
Function.update_noteq inr_ne_inl _ _
#align sum.update_inl_apply_inr Sum.update_inl_apply_inr
@[simp]
theorem update_inr_comp_inl [DecidableEq (Sum α β)] {f : Sum α β → γ} {i : β} {x : γ} :
update f (inr i) x ∘ inl = f ∘ inl :=
(update_comp_eq_of_forall_ne _ _) fun _ ↦ inl_ne_inr
#align sum.update_inr_comp_inl Sum.update_inr_comp_inl
theorem update_inr_apply_inl [DecidableEq (Sum α β)] {f : Sum α β → γ} {i : α} {j : β} {x : γ} :
update f (inr j) x (inl i) = f (inl i) :=
Function.update_noteq inl_ne_inr _ _
#align sum.update_inr_apply_inl Sum.update_inr_apply_inl
@[simp]
theorem update_inr_comp_inr [DecidableEq β] [DecidableEq (Sum α β)] {f : Sum α β → γ} {i : β}
{x : γ} : update f (inr i) x ∘ inr = update (f ∘ inr) i x :=
update_comp_eq_of_injective _ inr_injective _ _
#align sum.update_inr_comp_inr Sum.update_inr_comp_inr
@[simp]
theorem update_inr_apply_inr [DecidableEq β] [DecidableEq (Sum α β)] {f : Sum α β → γ} {i j : β}
{x : γ} : update f (inr i) x (inr j) = update (f ∘ inr) i x j := by
rw [← update_inr_comp_inr, Function.comp_apply]
#align sum.update_inr_apply_inr Sum.update_inr_apply_inr
#align sum.swap Sum.swap
#align sum.swap_inl Sum.swap_inl
#align sum.swap_inr Sum.swap_inr
#align sum.swap_swap Sum.swap_swap
#align sum.swap_swap_eq Sum.swap_swap_eq
@[simp]
theorem swap_leftInverse : Function.LeftInverse (@swap α β) swap :=
swap_swap
#align sum.swap_left_inverse Sum.swap_leftInverse
@[simp]
theorem swap_rightInverse : Function.RightInverse (@swap α β) swap :=
swap_swap
#align sum.swap_right_inverse Sum.swap_rightInverse
#align sum.is_left_swap Sum.isLeft_swap
#align sum.is_right_swap Sum.isRight_swap
#align sum.get_left_swap Sum.getLeft?_swap
#align sum.get_right_swap Sum.getRight?_swap
mk_iff_of_inductive_prop Sum.LiftRel Sum.liftRel_iff
namespace LiftRel
#align sum.lift_rel Sum.LiftRel
#align sum.lift_rel_inl_inl Sum.liftRel_inl_inl
#align sum.not_lift_rel_inl_inr Sum.not_liftRel_inl_inr
#align sum.not_lift_rel_inr_inl Sum.not_liftRel_inr_inl
#align sum.lift_rel_inr_inr Sum.liftRel_inr_inr
#align sum.lift_rel.mono Sum.LiftRel.mono
#align sum.lift_rel.mono_left Sum.LiftRel.mono_left
#align sum.lift_rel.mono_right Sum.LiftRel.mono_right
#align sum.lift_rel.swap Sum.LiftRel.swap
#align sum.lift_rel_swap_iff Sum.liftRel_swap_iff
variable {r : α → γ → Prop} {s : β → δ → Prop} {x : Sum α β} {y : Sum γ δ}
{a : α} {b : β} {c : γ} {d : δ}
| Mathlib/Data/Sum/Basic.lean | 210 | 210 | theorem isLeft_congr (h : LiftRel r s x y) : x.isLeft ↔ y.isLeft := by | cases h <;> rfl
|
import Mathlib.Data.Matrix.Basis
import Mathlib.LinearAlgebra.Basis
import Mathlib.LinearAlgebra.Pi
#align_import linear_algebra.std_basis from "leanprover-community/mathlib"@"13bce9a6b6c44f6b4c91ac1c1d2a816e2533d395"
open Function Set Submodule
namespace LinearMap
variable (R : Type*) {ι : Type*} [Semiring R] (φ : ι → Type*) [∀ i, AddCommMonoid (φ i)]
[∀ i, Module R (φ i)] [DecidableEq ι]
def stdBasis : ∀ i : ι, φ i →ₗ[R] ∀ i, φ i :=
single
#align linear_map.std_basis LinearMap.stdBasis
theorem stdBasis_apply (i : ι) (b : φ i) : stdBasis R φ i b = update (0 : (a : ι) → φ a) i b :=
rfl
#align linear_map.std_basis_apply LinearMap.stdBasis_apply
@[simp]
| Mathlib/LinearAlgebra/StdBasis.lean | 55 | 57 | theorem stdBasis_apply' (i i' : ι) : (stdBasis R (fun _x : ι => R) i) 1 i' = ite (i = i') 1 0 := by |
rw [LinearMap.stdBasis_apply, Function.update_apply, Pi.zero_apply]
congr 1; rw [eq_iff_iff, eq_comm]
|
import Mathlib.LinearAlgebra.AffineSpace.AffineMap
import Mathlib.Tactic.FieldSimp
#align_import linear_algebra.affine_space.slope from "leanprover-community/mathlib"@"70fd9563a21e7b963887c9360bd29b2393e6225a"
open AffineMap
variable {k E PE : Type*} [Field k] [AddCommGroup E] [Module k E] [AddTorsor E PE]
def slope (f : k → PE) (a b : k) : E :=
(b - a)⁻¹ • (f b -ᵥ f a)
#align slope slope
theorem slope_fun_def (f : k → PE) : slope f = fun a b => (b - a)⁻¹ • (f b -ᵥ f a) :=
rfl
#align slope_fun_def slope_fun_def
theorem slope_def_field (f : k → k) (a b : k) : slope f a b = (f b - f a) / (b - a) :=
(div_eq_inv_mul _ _).symm
#align slope_def_field slope_def_field
theorem slope_fun_def_field (f : k → k) (a : k) : slope f a = fun b => (f b - f a) / (b - a) :=
(div_eq_inv_mul _ _).symm
#align slope_fun_def_field slope_fun_def_field
@[simp]
theorem slope_same (f : k → PE) (a : k) : (slope f a a : E) = 0 := by
rw [slope, sub_self, inv_zero, zero_smul]
#align slope_same slope_same
theorem slope_def_module (f : k → E) (a b : k) : slope f a b = (b - a)⁻¹ • (f b - f a) :=
rfl
#align slope_def_module slope_def_module
@[simp]
theorem sub_smul_slope (f : k → PE) (a b : k) : (b - a) • slope f a b = f b -ᵥ f a := by
rcases eq_or_ne a b with (rfl | hne)
· rw [sub_self, zero_smul, vsub_self]
· rw [slope, smul_inv_smul₀ (sub_ne_zero.2 hne.symm)]
#align sub_smul_slope sub_smul_slope
theorem sub_smul_slope_vadd (f : k → PE) (a b : k) : (b - a) • slope f a b +ᵥ f a = f b := by
rw [sub_smul_slope, vsub_vadd]
#align sub_smul_slope_vadd sub_smul_slope_vadd
@[simp]
theorem slope_vadd_const (f : k → E) (c : PE) : (slope fun x => f x +ᵥ c) = slope f := by
ext a b
simp only [slope, vadd_vsub_vadd_cancel_right, vsub_eq_sub]
#align slope_vadd_const slope_vadd_const
@[simp]
theorem slope_sub_smul (f : k → E) {a b : k} (h : a ≠ b) :
slope (fun x => (x - a) • f x) a b = f b := by
simp [slope, inv_smul_smul₀ (sub_ne_zero.2 h.symm)]
#align slope_sub_smul slope_sub_smul
theorem eq_of_slope_eq_zero {f : k → PE} {a b : k} (h : slope f a b = (0 : E)) : f a = f b := by
rw [← sub_smul_slope_vadd f a b, h, smul_zero, zero_vadd]
#align eq_of_slope_eq_zero eq_of_slope_eq_zero
theorem AffineMap.slope_comp {F PF : Type*} [AddCommGroup F] [Module k F] [AddTorsor F PF]
(f : PE →ᵃ[k] PF) (g : k → PE) (a b : k) : slope (f ∘ g) a b = f.linear (slope g a b) := by
simp only [slope, (· ∘ ·), f.linear.map_smul, f.linearMap_vsub]
#align affine_map.slope_comp AffineMap.slope_comp
theorem LinearMap.slope_comp {F : Type*} [AddCommGroup F] [Module k F] (f : E →ₗ[k] F) (g : k → E)
(a b : k) : slope (f ∘ g) a b = f (slope g a b) :=
f.toAffineMap.slope_comp g a b
#align linear_map.slope_comp LinearMap.slope_comp
theorem slope_comm (f : k → PE) (a b : k) : slope f a b = slope f b a := by
rw [slope, slope, ← neg_vsub_eq_vsub_rev, smul_neg, ← neg_smul, neg_inv, neg_sub]
#align slope_comm slope_comm
@[simp] lemma slope_neg (f : k → E) (x y : k) : slope (fun t ↦ -f t) x y = -slope f x y := by
simp only [slope_def_module, neg_sub_neg, ← smul_neg, neg_sub]
| Mathlib/LinearAlgebra/AffineSpace/Slope.lean | 102 | 116 | theorem sub_div_sub_smul_slope_add_sub_div_sub_smul_slope (f : k → PE) (a b c : k) :
((b - a) / (c - a)) • slope f a b + ((c - b) / (c - a)) • slope f b c = slope f a c := by |
by_cases hab : a = b
· subst hab
rw [sub_self, zero_div, zero_smul, zero_add]
by_cases hac : a = c
· simp [hac]
· rw [div_self (sub_ne_zero.2 <| Ne.symm hac), one_smul]
by_cases hbc : b = c;
· subst hbc
simp [sub_ne_zero.2 (Ne.symm hab)]
rw [add_comm]
simp_rw [slope, div_eq_inv_mul, mul_smul, ← smul_add,
smul_inv_smul₀ (sub_ne_zero.2 <| Ne.symm hab), smul_inv_smul₀ (sub_ne_zero.2 <| Ne.symm hbc),
vsub_add_vsub_cancel]
|
import Mathlib.Order.Atoms
import Mathlib.Order.OrderIsoNat
import Mathlib.Order.RelIso.Set
import Mathlib.Order.SupClosed
import Mathlib.Order.SupIndep
import Mathlib.Order.Zorn
import Mathlib.Data.Finset.Order
import Mathlib.Order.Interval.Set.OrderIso
import Mathlib.Data.Finite.Set
import Mathlib.Tactic.TFAE
#align_import order.compactly_generated from "leanprover-community/mathlib"@"c813ed7de0f5115f956239124e9b30f3a621966f"
open Set
variable {ι : Sort*} {α : Type*} [CompleteLattice α] {f : ι → α}
namespace CompleteLattice
variable (α)
def IsSupClosedCompact : Prop :=
∀ (s : Set α) (_ : s.Nonempty), SupClosed s → sSup s ∈ s
#align complete_lattice.is_sup_closed_compact CompleteLattice.IsSupClosedCompact
def IsSupFiniteCompact : Prop :=
∀ s : Set α, ∃ t : Finset α, ↑t ⊆ s ∧ sSup s = t.sup id
#align complete_lattice.is_Sup_finite_compact CompleteLattice.IsSupFiniteCompact
def IsCompactElement {α : Type*} [CompleteLattice α] (k : α) :=
∀ s : Set α, k ≤ sSup s → ∃ t : Finset α, ↑t ⊆ s ∧ k ≤ t.sup id
#align complete_lattice.is_compact_element CompleteLattice.IsCompactElement
theorem isCompactElement_iff.{u} {α : Type u} [CompleteLattice α] (k : α) :
CompleteLattice.IsCompactElement k ↔
∀ (ι : Type u) (s : ι → α), k ≤ iSup s → ∃ t : Finset ι, k ≤ t.sup s := by
classical
constructor
· intro H ι s hs
obtain ⟨t, ht, ht'⟩ := H (Set.range s) hs
have : ∀ x : t, ∃ i, s i = x := fun x => ht x.prop
choose f hf using this
refine ⟨Finset.univ.image f, ht'.trans ?_⟩
rw [Finset.sup_le_iff]
intro b hb
rw [← show s (f ⟨b, hb⟩) = id b from hf _]
exact Finset.le_sup (Finset.mem_image_of_mem f <| Finset.mem_univ (Subtype.mk b hb))
· intro H s hs
obtain ⟨t, ht⟩ :=
H s Subtype.val
(by
delta iSup
rwa [Subtype.range_coe])
refine ⟨t.image Subtype.val, by simp, ht.trans ?_⟩
rw [Finset.sup_le_iff]
exact fun x hx => @Finset.le_sup _ _ _ _ _ id _ (Finset.mem_image_of_mem Subtype.val hx)
#align complete_lattice.is_compact_element_iff CompleteLattice.isCompactElement_iff
theorem isCompactElement_iff_le_of_directed_sSup_le (k : α) :
IsCompactElement k ↔
∀ s : Set α, s.Nonempty → DirectedOn (· ≤ ·) s → k ≤ sSup s → ∃ x : α, x ∈ s ∧ k ≤ x := by
classical
constructor
· intro hk s hne hdir hsup
obtain ⟨t, ht⟩ := hk s hsup
-- certainly every element of t is below something in s, since ↑t ⊆ s.
have t_below_s : ∀ x ∈ t, ∃ y ∈ s, x ≤ y := fun x hxt => ⟨x, ht.left hxt, le_rfl⟩
obtain ⟨x, ⟨hxs, hsupx⟩⟩ := Finset.sup_le_of_le_directed s hne hdir t t_below_s
exact ⟨x, ⟨hxs, le_trans ht.right hsupx⟩⟩
· intro hk s hsup
-- Consider the set of finite joins of elements of the (plain) set s.
let S : Set α := { x | ∃ t : Finset α, ↑t ⊆ s ∧ x = t.sup id }
-- S is directed, nonempty, and still has sup above k.
have dir_US : DirectedOn (· ≤ ·) S := by
rintro x ⟨c, hc⟩ y ⟨d, hd⟩
use x ⊔ y
constructor
· use c ∪ d
constructor
· simp only [hc.left, hd.left, Set.union_subset_iff, Finset.coe_union, and_self_iff]
· simp only [hc.right, hd.right, Finset.sup_union]
simp only [and_self_iff, le_sup_left, le_sup_right]
have sup_S : sSup s ≤ sSup S := by
apply sSup_le_sSup
intro x hx
use {x}
simpa only [and_true_iff, id, Finset.coe_singleton, eq_self_iff_true,
Finset.sup_singleton, Set.singleton_subset_iff]
have Sne : S.Nonempty := by
suffices ⊥ ∈ S from Set.nonempty_of_mem this
use ∅
simp only [Set.empty_subset, Finset.coe_empty, Finset.sup_empty, eq_self_iff_true,
and_self_iff]
-- Now apply the defn of compact and finish.
obtain ⟨j, ⟨hjS, hjk⟩⟩ := hk S Sne dir_US (le_trans hsup sup_S)
obtain ⟨t, ⟨htS, htsup⟩⟩ := hjS
use t
exact ⟨htS, by rwa [← htsup]⟩
#align complete_lattice.is_compact_element_iff_le_of_directed_Sup_le CompleteLattice.isCompactElement_iff_le_of_directed_sSup_le
theorem IsCompactElement.exists_finset_of_le_iSup {k : α} (hk : IsCompactElement k) {ι : Type*}
(f : ι → α) (h : k ≤ ⨆ i, f i) : ∃ s : Finset ι, k ≤ ⨆ i ∈ s, f i := by
classical
let g : Finset ι → α := fun s => ⨆ i ∈ s, f i
have h1 : DirectedOn (· ≤ ·) (Set.range g) := by
rintro - ⟨s, rfl⟩ - ⟨t, rfl⟩
exact
⟨g (s ∪ t), ⟨s ∪ t, rfl⟩, iSup_le_iSup_of_subset Finset.subset_union_left,
iSup_le_iSup_of_subset Finset.subset_union_right⟩
have h2 : k ≤ sSup (Set.range g) :=
h.trans
(iSup_le fun i =>
le_sSup_of_le ⟨{i}, rfl⟩
(le_iSup_of_le i (le_iSup_of_le (Finset.mem_singleton_self i) le_rfl)))
obtain ⟨-, ⟨s, rfl⟩, hs⟩ :=
(isCompactElement_iff_le_of_directed_sSup_le α k).mp hk (Set.range g) (Set.range_nonempty g)
h1 h2
exact ⟨s, hs⟩
#align complete_lattice.is_compact_element.exists_finset_of_le_supr CompleteLattice.IsCompactElement.exists_finset_of_le_iSup
theorem IsCompactElement.directed_sSup_lt_of_lt {α : Type*} [CompleteLattice α] {k : α}
(hk : IsCompactElement k) {s : Set α} (hemp : s.Nonempty) (hdir : DirectedOn (· ≤ ·) s)
(hbelow : ∀ x ∈ s, x < k) : sSup s < k := by
rw [isCompactElement_iff_le_of_directed_sSup_le] at hk
by_contra h
have sSup' : sSup s ≤ k := sSup_le s k fun s hs => (hbelow s hs).le
replace sSup : sSup s = k := eq_iff_le_not_lt.mpr ⟨sSup', h⟩
obtain ⟨x, hxs, hkx⟩ := hk s hemp hdir sSup.symm.le
obtain hxk := hbelow x hxs
exact hxk.ne (hxk.le.antisymm hkx)
#align complete_lattice.is_compact_element.directed_Sup_lt_of_lt CompleteLattice.IsCompactElement.directed_sSup_lt_of_lt
| Mathlib/Order/CompactlyGenerated/Basic.lean | 186 | 199 | theorem isCompactElement_finsetSup {α β : Type*} [CompleteLattice α] {f : β → α} (s : Finset β)
(h : ∀ x ∈ s, IsCompactElement (f x)) : IsCompactElement (s.sup f) := by |
classical
rw [isCompactElement_iff_le_of_directed_sSup_le]
intro d hemp hdir hsup
rw [← Function.id_comp f]
rw [← Finset.sup_image]
apply Finset.sup_le_of_le_directed d hemp hdir
rintro x hx
obtain ⟨p, ⟨hps, rfl⟩⟩ := Finset.mem_image.mp hx
specialize h p hps
rw [isCompactElement_iff_le_of_directed_sSup_le] at h
specialize h d hemp hdir (le_trans (Finset.le_sup hps) hsup)
simpa only [exists_prop]
|
import Mathlib.NumberTheory.LegendreSymbol.QuadraticChar.Basic
#align_import number_theory.legendre_symbol.basic from "leanprover-community/mathlib"@"5b2fe80501ff327b9109fb09b7cc8c325cd0d7d9"
open Nat
section Euler
section Legendre
open ZMod
variable (p : ℕ) [Fact p.Prime]
def legendreSym (a : ℤ) : ℤ :=
quadraticChar (ZMod p) a
#align legendre_sym legendreSym
section Values
variable {p : ℕ} [Fact p.Prime]
open ZMod
| Mathlib/NumberTheory/LegendreSymbol/Basic.lean | 294 | 296 | theorem legendreSym.at_neg_one (hp : p ≠ 2) : legendreSym p (-1) = χ₄ p := by |
simp only [legendreSym, card p, quadraticChar_neg_one ((ringChar_zmod_n p).substr hp),
Int.cast_neg, Int.cast_one]
|
import Mathlib.Algebra.Algebra.Prod
import Mathlib.Algebra.Algebra.Subalgebra.Basic
#align_import algebra.algebra.subalgebra.basic from "leanprover-community/mathlib"@"b915e9392ecb2a861e1e766f0e1df6ac481188ca"
namespace Subalgebra
open Algebra
variable {R A B : Type*} [CommSemiring R] [Semiring A] [Algebra R A] [Semiring B] [Algebra R B]
variable (S : Subalgebra R A) (S₁ : Subalgebra R B)
def prod : Subalgebra R (A × B) :=
{ S.toSubsemiring.prod S₁.toSubsemiring with
carrier := S ×ˢ S₁
algebraMap_mem' := fun _ => ⟨algebraMap_mem _ _, algebraMap_mem _ _⟩ }
#align subalgebra.prod Subalgebra.prod
@[simp]
theorem coe_prod : (prod S S₁ : Set (A × B)) = (S : Set A) ×ˢ (S₁ : Set B) :=
rfl
#align subalgebra.coe_prod Subalgebra.coe_prod
open Subalgebra in
theorem prod_toSubmodule : toSubmodule (S.prod S₁) = (toSubmodule S).prod (toSubmodule S₁) := rfl
#align subalgebra.prod_to_submodule Subalgebra.prod_toSubmodule
@[simp]
theorem mem_prod {S : Subalgebra R A} {S₁ : Subalgebra R B} {x : A × B} :
x ∈ prod S S₁ ↔ x.1 ∈ S ∧ x.2 ∈ S₁ := Set.mem_prod
#align subalgebra.mem_prod Subalgebra.mem_prod
@[simp]
| Mathlib/Algebra/Algebra/Subalgebra/Prod.lean | 51 | 51 | theorem prod_top : (prod ⊤ ⊤ : Subalgebra R (A × B)) = ⊤ := by | ext; simp
|
import Mathlib.GroupTheory.CoprodI
import Mathlib.GroupTheory.Coprod.Basic
import Mathlib.GroupTheory.QuotientGroup
import Mathlib.GroupTheory.Complement
namespace Monoid
open CoprodI Subgroup Coprod Function List
variable {ι : Type*} {G : ι → Type*} {H : Type*} {K : Type*} [Monoid K]
def PushoutI.con [∀ i, Monoid (G i)] [Monoid H] (φ : ∀ i, H →* G i) :
Con (Coprod (CoprodI G) H) :=
conGen (fun x y : Coprod (CoprodI G) H =>
∃ i x', x = inl (of (φ i x')) ∧ y = inr x')
def PushoutI [∀ i, Monoid (G i)] [Monoid H] (φ : ∀ i, H →* G i) : Type _ :=
(PushoutI.con φ).Quotient
namespace PushoutI
section Monoid
variable [∀ i, Monoid (G i)] [Monoid H] {φ : ∀ i, H →* G i}
protected instance mul : Mul (PushoutI φ) := by
delta PushoutI; infer_instance
protected instance one : One (PushoutI φ) := by
delta PushoutI; infer_instance
instance monoid : Monoid (PushoutI φ) :=
{ Con.monoid _ with
toMul := PushoutI.mul
toOne := PushoutI.one }
def of (i : ι) : G i →* PushoutI φ :=
(Con.mk' _).comp <| inl.comp CoprodI.of
variable (φ) in
def base : H →* PushoutI φ :=
(Con.mk' _).comp inr
theorem of_comp_eq_base (i : ι) : (of i).comp (φ i) = (base φ) := by
ext x
apply (Con.eq _).2
refine ConGen.Rel.of _ _ ?_
simp only [MonoidHom.comp_apply, Set.mem_iUnion, Set.mem_range]
exact ⟨_, _, rfl, rfl⟩
variable (φ) in
| Mathlib/GroupTheory/PushoutI.lean | 96 | 97 | theorem of_apply_eq_base (i : ι) (x : H) : of i (φ i x) = base φ x := by |
rw [← MonoidHom.comp_apply, of_comp_eq_base]
|
import Mathlib.Data.List.Chain
import Mathlib.Data.List.Enum
import Mathlib.Data.List.Nodup
import Mathlib.Data.List.Pairwise
import Mathlib.Data.List.Zip
#align_import data.list.range from "leanprover-community/mathlib"@"7b78d1776212a91ecc94cf601f83bdcc46b04213"
set_option autoImplicit true
universe u
open Nat
namespace List
variable {α : Type u}
@[simp] theorem range'_one {step} : range' s 1 step = [s] := rfl
#align list.length_range' List.length_range'
#align list.range'_eq_nil List.range'_eq_nil
#align list.mem_range' List.mem_range'_1
#align list.map_add_range' List.map_add_range'
#align list.map_sub_range' List.map_sub_range'
#align list.chain_succ_range' List.chain_succ_range'
#align list.chain_lt_range' List.chain_lt_range'
theorem pairwise_lt_range' : ∀ s n (step := 1) (_ : 0 < step := by simp),
Pairwise (· < ·) (range' s n step)
| _, 0, _, _ => Pairwise.nil
| s, n + 1, _, h => chain_iff_pairwise.1 (chain_lt_range' s n h)
#align list.pairwise_lt_range' List.pairwise_lt_range'
theorem nodup_range' (s n : ℕ) (step := 1) (h : 0 < step := by simp) : Nodup (range' s n step) :=
(pairwise_lt_range' s n step h).imp _root_.ne_of_lt
#align list.nodup_range' List.nodup_range'
#align list.range'_append List.range'_append
#align list.range'_sublist_right List.range'_sublist_right
#align list.range'_subset_right List.range'_subset_right
#align list.nth_range' List.get?_range'
set_option linter.deprecated false in
@[simp]
theorem nthLe_range' {n m step} (i) (H : i < (range' n m step).length) :
nthLe (range' n m step) i H = n + step * i := get_range' i H
set_option linter.deprecated false in
| Mathlib/Data/List/Range.lean | 66 | 67 | theorem nthLe_range'_1 {n m} (i) (H : i < (range' n m).length) :
nthLe (range' n m) i H = n + i := by | simp
|
import Mathlib.LinearAlgebra.Dimension.Constructions
import Mathlib.LinearAlgebra.Dimension.Finite
universe u v
open Function Set Cardinal
variable {R} {M M₁ M₂ M₃ : Type u} {M' : Type v} [Ring R]
variable [AddCommGroup M] [AddCommGroup M₁] [AddCommGroup M₂] [AddCommGroup M₃] [AddCommGroup M']
variable [Module R M] [Module R M₁] [Module R M₂] [Module R M₃] [Module R M']
@[pp_with_univ]
class HasRankNullity (R : Type v) [inst : Ring R] : Prop where
exists_set_linearIndependent : ∀ (M : Type u) [AddCommGroup M] [Module R M],
∃ s : Set M, #s = Module.rank R M ∧ LinearIndependent (ι := s) R Subtype.val
rank_quotient_add_rank : ∀ {M : Type u} [AddCommGroup M] [Module R M] (N : Submodule R M),
Module.rank R (M ⧸ N) + Module.rank R N = Module.rank R M
variable [HasRankNullity.{u} R]
lemma rank_quotient_add_rank (N : Submodule R M) :
Module.rank R (M ⧸ N) + Module.rank R N = Module.rank R M :=
HasRankNullity.rank_quotient_add_rank N
#align rank_quotient_add_rank rank_quotient_add_rank
variable (R M) in
lemma exists_set_linearIndependent :
∃ s : Set M, #s = Module.rank R M ∧ LinearIndependent (ι := s) R Subtype.val :=
HasRankNullity.exists_set_linearIndependent M
variable (R) in
instance (priority := 100) : Nontrivial R := by
refine (subsingleton_or_nontrivial R).resolve_left fun H ↦ ?_
have := rank_quotient_add_rank (R := R) (M := PUnit) ⊥
simp [one_add_one_eq_two] at this
theorem lift_rank_range_add_rank_ker (f : M →ₗ[R] M') :
lift.{u} (Module.rank R (LinearMap.range f)) + lift.{v} (Module.rank R (LinearMap.ker f)) =
lift.{v} (Module.rank R M) := by
haveI := fun p : Submodule R M => Classical.decEq (M ⧸ p)
rw [← f.quotKerEquivRange.lift_rank_eq, ← lift_add, rank_quotient_add_rank]
theorem rank_range_add_rank_ker (f : M →ₗ[R] M₁) :
Module.rank R (LinearMap.range f) + Module.rank R (LinearMap.ker f) = Module.rank R M := by
haveI := fun p : Submodule R M => Classical.decEq (M ⧸ p)
rw [← f.quotKerEquivRange.rank_eq, rank_quotient_add_rank]
#align rank_range_add_rank_ker rank_range_add_rank_ker
theorem lift_rank_eq_of_surjective {f : M →ₗ[R] M'} (h : Surjective f) :
lift.{v} (Module.rank R M) =
lift.{u} (Module.rank R M') + lift.{v} (Module.rank R (LinearMap.ker f)) := by
rw [← lift_rank_range_add_rank_ker f, ← rank_range_of_surjective f h]
theorem rank_eq_of_surjective {f : M →ₗ[R] M₁} (h : Surjective f) :
Module.rank R M = Module.rank R M₁ + Module.rank R (LinearMap.ker f) := by
rw [← rank_range_add_rank_ker f, ← rank_range_of_surjective f h]
#align rank_eq_of_surjective rank_eq_of_surjective
theorem exists_linearIndependent_of_lt_rank [StrongRankCondition R]
{s : Set M} (hs : LinearIndependent (ι := s) R Subtype.val) :
∃ t, s ⊆ t ∧ #t = Module.rank R M ∧ LinearIndependent (ι := t) R Subtype.val := by
obtain ⟨t, ht, ht'⟩ := exists_set_linearIndependent R (M ⧸ Submodule.span R s)
choose sec hsec using Submodule.Quotient.mk_surjective (Submodule.span R s)
have hsec' : Submodule.Quotient.mk ∘ sec = id := funext hsec
have hst : Disjoint s (sec '' t) := by
rw [Set.disjoint_iff]
rintro _ ⟨hxs, ⟨x, hxt, rfl⟩⟩
apply ht'.ne_zero ⟨x, hxt⟩
rw [Subtype.coe_mk, ← hsec x, Submodule.Quotient.mk_eq_zero]
exact Submodule.subset_span hxs
refine ⟨s ∪ sec '' t, subset_union_left, ?_, ?_⟩
· rw [Cardinal.mk_union_of_disjoint hst, Cardinal.mk_image_eq, ht,
← rank_quotient_add_rank (Submodule.span R s), add_comm, rank_span_set hs]
exact HasLeftInverse.injective ⟨Submodule.Quotient.mk, hsec⟩
· apply LinearIndependent.union_of_quotient Submodule.subset_span hs
rwa [Function.comp, linearIndependent_image (hsec'.symm ▸ injective_id).injOn.image_of_comp,
← image_comp, hsec', image_id]
theorem exists_linearIndependent_cons_of_lt_rank [StrongRankCondition R] {n : ℕ} {v : Fin n → M}
(hv : LinearIndependent R v) (h : n < Module.rank R M) :
∃ (x : M), LinearIndependent R (Fin.cons x v) := by
obtain ⟨t, h₁, h₂, h₃⟩ := exists_linearIndependent_of_lt_rank hv.to_subtype_range
have : range v ≠ t := by
refine fun e ↦ h.ne ?_
rw [← e, ← lift_injective.eq_iff, mk_range_eq_of_injective hv.injective] at h₂
simpa only [mk_fintype, Fintype.card_fin, lift_natCast, lift_id'] using h₂
obtain ⟨x, hx, hx'⟩ := nonempty_of_ssubset (h₁.ssubset_of_ne this)
exact ⟨x, (linearIndependent_subtype_range (Fin.cons_injective_iff.mpr ⟨hx', hv.injective⟩)).mp
(h₃.mono (Fin.range_cons x v ▸ insert_subset hx h₁))⟩
theorem exists_linearIndependent_snoc_of_lt_rank [StrongRankCondition R] {n : ℕ} {v : Fin n → M}
(hv : LinearIndependent R v) (h : n < Module.rank R M) :
∃ (x : M), LinearIndependent R (Fin.snoc v x) := by
simp only [Fin.snoc_eq_cons_rotate]
have ⟨x, hx⟩ := exists_linearIndependent_cons_of_lt_rank hv h
exact ⟨x, hx.comp _ (finRotate _).injective⟩
theorem exists_linearIndependent_pair_of_one_lt_rank [StrongRankCondition R]
[NoZeroSMulDivisors R M] (h : 1 < Module.rank R M) {x : M} (hx : x ≠ 0) :
∃ y, LinearIndependent R ![x, y] := by
obtain ⟨y, hy⟩ := exists_linearIndependent_snoc_of_lt_rank (linearIndependent_unique ![x] hx) h
have : Fin.snoc ![x] y = ![x, y] := Iff.mp List.ofFn_inj rfl
rw [this] at hy
exact ⟨y, hy⟩
theorem exists_smul_not_mem_of_rank_lt {N : Submodule R M} (h : Module.rank R N < Module.rank R M) :
∃ m : M, ∀ r : R, r ≠ 0 → r • m ∉ N := by
have : Module.rank R (M ⧸ N) ≠ 0 := by
intro e
rw [← rank_quotient_add_rank N, e, zero_add] at h
exact h.ne rfl
rw [ne_eq, rank_eq_zero_iff, (Submodule.Quotient.mk_surjective N).forall] at this
push_neg at this
simp_rw [← N.mkQ_apply, ← map_smul, N.mkQ_apply, ne_eq, Submodule.Quotient.mk_eq_zero] at this
exact this
open Cardinal Basis Submodule Function Set LinearMap
theorem Submodule.rank_sup_add_rank_inf_eq (s t : Submodule R M) :
Module.rank R (s ⊔ t : Submodule R M) + Module.rank R (s ⊓ t : Submodule R M) =
Module.rank R s + Module.rank R t := by
conv_rhs => enter [2]; rw [show t = (s ⊔ t) ⊓ t by simp]
rw [← rank_quotient_add_rank ((s ⊓ t).comap s.subtype),
← rank_quotient_add_rank (t.comap (s ⊔ t).subtype),
(quotientInfEquivSupQuotient s t).rank_eq,
(equivSubtypeMap s (comap _ (s ⊓ t))).rank_eq, Submodule.map_comap_subtype,
(equivSubtypeMap (s ⊔ t) (comap _ t)).rank_eq, Submodule.map_comap_subtype,
← inf_assoc, inf_idem, add_right_comm]
#align submodule.rank_sup_add_rank_inf_eq Submodule.rank_sup_add_rank_inf_eq
| Mathlib/LinearAlgebra/Dimension/RankNullity.lean | 169 | 172 | theorem Submodule.rank_add_le_rank_add_rank (s t : Submodule R M) :
Module.rank R (s ⊔ t : Submodule R M) ≤ Module.rank R s + Module.rank R t := by |
rw [← Submodule.rank_sup_add_rank_inf_eq]
exact self_le_add_right _ _
|
import Mathlib.ModelTheory.Ultraproducts
import Mathlib.ModelTheory.Bundled
import Mathlib.ModelTheory.Skolem
#align_import model_theory.satisfiability from "leanprover-community/mathlib"@"d565b3df44619c1498326936be16f1a935df0728"
set_option linter.uppercaseLean3 false
universe u v w w'
open Cardinal CategoryTheory
open Cardinal FirstOrder
namespace FirstOrder
namespace Language
variable {L : Language.{u, v}} {T : L.Theory} {α : Type w} {n : ℕ}
variable (L)
| Mathlib/ModelTheory/Satisfiability.lean | 212 | 224 | theorem exists_elementaryEmbedding_card_eq_of_le (M : Type w') [L.Structure M] [Nonempty M]
(κ : Cardinal.{w}) (h1 : ℵ₀ ≤ κ) (h2 : lift.{w} L.card ≤ Cardinal.lift.{max u v} κ)
(h3 : lift.{w'} κ ≤ Cardinal.lift.{w} #M) :
∃ N : Bundled L.Structure, Nonempty (N ↪ₑ[L] M) ∧ #N = κ := by |
obtain ⟨S, _, hS⟩ := exists_elementarySubstructure_card_eq L ∅ κ h1 (by simp) h2 h3
have : Small.{w} S := by
rw [← lift_inj.{_, w + 1}, lift_lift, lift_lift] at hS
exact small_iff_lift_mk_lt_univ.2 (lt_of_eq_of_lt hS κ.lift_lt_univ')
refine
⟨(equivShrink S).bundledInduced L,
⟨S.subtype.comp (Equiv.bundledInducedEquiv L _).symm.toElementaryEmbedding⟩,
lift_inj.1 (_root_.trans ?_ hS)⟩
simp only [Equiv.bundledInduced_α, lift_mk_shrink']
|
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 LinearOrderedField
variable [LinearOrderedField α] {a : α}
@[simp]
theorem preimage_mul_const_Iio (a : α) {c : α} (h : 0 < c) :
(fun x => x * c) ⁻¹' Iio a = Iio (a / c) :=
ext fun _x => (lt_div_iff h).symm
#align set.preimage_mul_const_Iio Set.preimage_mul_const_Iio
@[simp]
theorem preimage_mul_const_Ioi (a : α) {c : α} (h : 0 < c) :
(fun x => x * c) ⁻¹' Ioi a = Ioi (a / c) :=
ext fun _x => (div_lt_iff h).symm
#align set.preimage_mul_const_Ioi Set.preimage_mul_const_Ioi
@[simp]
theorem preimage_mul_const_Iic (a : α) {c : α} (h : 0 < c) :
(fun x => x * c) ⁻¹' Iic a = Iic (a / c) :=
ext fun _x => (le_div_iff h).symm
#align set.preimage_mul_const_Iic Set.preimage_mul_const_Iic
@[simp]
theorem preimage_mul_const_Ici (a : α) {c : α} (h : 0 < c) :
(fun x => x * c) ⁻¹' Ici a = Ici (a / c) :=
ext fun _x => (div_le_iff h).symm
#align set.preimage_mul_const_Ici Set.preimage_mul_const_Ici
@[simp]
theorem preimage_mul_const_Ioo (a b : α) {c : α} (h : 0 < c) :
(fun x => x * c) ⁻¹' Ioo a b = Ioo (a / c) (b / c) := by simp [← Ioi_inter_Iio, h]
#align set.preimage_mul_const_Ioo Set.preimage_mul_const_Ioo
@[simp]
theorem preimage_mul_const_Ioc (a b : α) {c : α} (h : 0 < c) :
(fun x => x * c) ⁻¹' Ioc a b = Ioc (a / c) (b / c) := by simp [← Ioi_inter_Iic, h]
#align set.preimage_mul_const_Ioc Set.preimage_mul_const_Ioc
@[simp]
theorem preimage_mul_const_Ico (a b : α) {c : α} (h : 0 < c) :
(fun x => x * c) ⁻¹' Ico a b = Ico (a / c) (b / c) := by simp [← Ici_inter_Iio, h]
#align set.preimage_mul_const_Ico Set.preimage_mul_const_Ico
@[simp]
theorem preimage_mul_const_Icc (a b : α) {c : α} (h : 0 < c) :
(fun x => x * c) ⁻¹' Icc a b = Icc (a / c) (b / c) := by simp [← Ici_inter_Iic, h]
#align set.preimage_mul_const_Icc Set.preimage_mul_const_Icc
@[simp]
theorem preimage_mul_const_Iio_of_neg (a : α) {c : α} (h : c < 0) :
(fun x => x * c) ⁻¹' Iio a = Ioi (a / c) :=
ext fun _x => (div_lt_iff_of_neg h).symm
#align set.preimage_mul_const_Iio_of_neg Set.preimage_mul_const_Iio_of_neg
@[simp]
theorem preimage_mul_const_Ioi_of_neg (a : α) {c : α} (h : c < 0) :
(fun x => x * c) ⁻¹' Ioi a = Iio (a / c) :=
ext fun _x => (lt_div_iff_of_neg h).symm
#align set.preimage_mul_const_Ioi_of_neg Set.preimage_mul_const_Ioi_of_neg
@[simp]
theorem preimage_mul_const_Iic_of_neg (a : α) {c : α} (h : c < 0) :
(fun x => x * c) ⁻¹' Iic a = Ici (a / c) :=
ext fun _x => (div_le_iff_of_neg h).symm
#align set.preimage_mul_const_Iic_of_neg Set.preimage_mul_const_Iic_of_neg
@[simp]
theorem preimage_mul_const_Ici_of_neg (a : α) {c : α} (h : c < 0) :
(fun x => x * c) ⁻¹' Ici a = Iic (a / c) :=
ext fun _x => (le_div_iff_of_neg h).symm
#align set.preimage_mul_const_Ici_of_neg Set.preimage_mul_const_Ici_of_neg
@[simp]
theorem preimage_mul_const_Ioo_of_neg (a b : α) {c : α} (h : c < 0) :
(fun x => x * c) ⁻¹' Ioo a b = Ioo (b / c) (a / c) := by simp [← Ioi_inter_Iio, h, inter_comm]
#align set.preimage_mul_const_Ioo_of_neg Set.preimage_mul_const_Ioo_of_neg
@[simp]
theorem preimage_mul_const_Ioc_of_neg (a b : α) {c : α} (h : c < 0) :
(fun x => x * c) ⁻¹' Ioc a b = Ico (b / c) (a / c) := by
simp [← Ioi_inter_Iic, ← Ici_inter_Iio, h, inter_comm]
#align set.preimage_mul_const_Ioc_of_neg Set.preimage_mul_const_Ioc_of_neg
@[simp]
theorem preimage_mul_const_Ico_of_neg (a b : α) {c : α} (h : c < 0) :
(fun x => x * c) ⁻¹' Ico a b = Ioc (b / c) (a / c) := by
simp [← Ici_inter_Iio, ← Ioi_inter_Iic, h, inter_comm]
#align set.preimage_mul_const_Ico_of_neg Set.preimage_mul_const_Ico_of_neg
@[simp]
theorem preimage_mul_const_Icc_of_neg (a b : α) {c : α} (h : c < 0) :
(fun x => x * c) ⁻¹' Icc a b = Icc (b / c) (a / c) := by simp [← Ici_inter_Iic, h, inter_comm]
#align set.preimage_mul_const_Icc_of_neg Set.preimage_mul_const_Icc_of_neg
@[simp]
theorem preimage_const_mul_Iio (a : α) {c : α} (h : 0 < c) : (c * ·) ⁻¹' Iio a = Iio (a / c) :=
ext fun _x => (lt_div_iff' h).symm
#align set.preimage_const_mul_Iio Set.preimage_const_mul_Iio
@[simp]
theorem preimage_const_mul_Ioi (a : α) {c : α} (h : 0 < c) : (c * ·) ⁻¹' Ioi a = Ioi (a / c) :=
ext fun _x => (div_lt_iff' h).symm
#align set.preimage_const_mul_Ioi Set.preimage_const_mul_Ioi
@[simp]
theorem preimage_const_mul_Iic (a : α) {c : α} (h : 0 < c) : (c * ·) ⁻¹' Iic a = Iic (a / c) :=
ext fun _x => (le_div_iff' h).symm
#align set.preimage_const_mul_Iic Set.preimage_const_mul_Iic
@[simp]
theorem preimage_const_mul_Ici (a : α) {c : α} (h : 0 < c) : (c * ·) ⁻¹' Ici a = Ici (a / c) :=
ext fun _x => (div_le_iff' h).symm
#align set.preimage_const_mul_Ici Set.preimage_const_mul_Ici
@[simp]
theorem preimage_const_mul_Ioo (a b : α) {c : α} (h : 0 < c) :
(c * ·) ⁻¹' Ioo a b = Ioo (a / c) (b / c) := by simp [← Ioi_inter_Iio, h]
#align set.preimage_const_mul_Ioo Set.preimage_const_mul_Ioo
@[simp]
theorem preimage_const_mul_Ioc (a b : α) {c : α} (h : 0 < c) :
(c * ·) ⁻¹' Ioc a b = Ioc (a / c) (b / c) := by simp [← Ioi_inter_Iic, h]
#align set.preimage_const_mul_Ioc Set.preimage_const_mul_Ioc
@[simp]
theorem preimage_const_mul_Ico (a b : α) {c : α} (h : 0 < c) :
(c * ·) ⁻¹' Ico a b = Ico (a / c) (b / c) := by simp [← Ici_inter_Iio, h]
#align set.preimage_const_mul_Ico Set.preimage_const_mul_Ico
@[simp]
theorem preimage_const_mul_Icc (a b : α) {c : α} (h : 0 < c) :
(c * ·) ⁻¹' Icc a b = Icc (a / c) (b / c) := by simp [← Ici_inter_Iic, h]
#align set.preimage_const_mul_Icc Set.preimage_const_mul_Icc
@[simp]
theorem preimage_const_mul_Iio_of_neg (a : α) {c : α} (h : c < 0) :
(c * ·) ⁻¹' Iio a = Ioi (a / c) := by
simpa only [mul_comm] using preimage_mul_const_Iio_of_neg a h
#align set.preimage_const_mul_Iio_of_neg Set.preimage_const_mul_Iio_of_neg
@[simp]
theorem preimage_const_mul_Ioi_of_neg (a : α) {c : α} (h : c < 0) :
(c * ·) ⁻¹' Ioi a = Iio (a / c) := by
simpa only [mul_comm] using preimage_mul_const_Ioi_of_neg a h
#align set.preimage_const_mul_Ioi_of_neg Set.preimage_const_mul_Ioi_of_neg
@[simp]
theorem preimage_const_mul_Iic_of_neg (a : α) {c : α} (h : c < 0) :
(c * ·) ⁻¹' Iic a = Ici (a / c) := by
simpa only [mul_comm] using preimage_mul_const_Iic_of_neg a h
#align set.preimage_const_mul_Iic_of_neg Set.preimage_const_mul_Iic_of_neg
@[simp]
theorem preimage_const_mul_Ici_of_neg (a : α) {c : α} (h : c < 0) :
(c * ·) ⁻¹' Ici a = Iic (a / c) := by
simpa only [mul_comm] using preimage_mul_const_Ici_of_neg a h
#align set.preimage_const_mul_Ici_of_neg Set.preimage_const_mul_Ici_of_neg
@[simp]
theorem preimage_const_mul_Ioo_of_neg (a b : α) {c : α} (h : c < 0) :
(c * ·) ⁻¹' Ioo a b = Ioo (b / c) (a / c) := by
simpa only [mul_comm] using preimage_mul_const_Ioo_of_neg a b h
#align set.preimage_const_mul_Ioo_of_neg Set.preimage_const_mul_Ioo_of_neg
@[simp]
theorem preimage_const_mul_Ioc_of_neg (a b : α) {c : α} (h : c < 0) :
(c * ·) ⁻¹' Ioc a b = Ico (b / c) (a / c) := by
simpa only [mul_comm] using preimage_mul_const_Ioc_of_neg a b h
#align set.preimage_const_mul_Ioc_of_neg Set.preimage_const_mul_Ioc_of_neg
@[simp]
theorem preimage_const_mul_Ico_of_neg (a b : α) {c : α} (h : c < 0) :
(c * ·) ⁻¹' Ico a b = Ioc (b / c) (a / c) := by
simpa only [mul_comm] using preimage_mul_const_Ico_of_neg a b h
#align set.preimage_const_mul_Ico_of_neg Set.preimage_const_mul_Ico_of_neg
@[simp]
theorem preimage_const_mul_Icc_of_neg (a b : α) {c : α} (h : c < 0) :
(c * ·) ⁻¹' Icc a b = Icc (b / c) (a / c) := by
simpa only [mul_comm] using preimage_mul_const_Icc_of_neg a b h
#align set.preimage_const_mul_Icc_of_neg Set.preimage_const_mul_Icc_of_neg
@[simp]
theorem preimage_mul_const_uIcc (ha : a ≠ 0) (b c : α) :
(· * a) ⁻¹' [[b, c]] = [[b / a, c / a]] :=
(lt_or_gt_of_ne ha).elim
(fun h => by
simp [← Icc_min_max, h, h.le, min_div_div_right_of_nonpos, max_div_div_right_of_nonpos])
fun ha : 0 < a => by simp [← Icc_min_max, ha, ha.le, min_div_div_right, max_div_div_right]
#align set.preimage_mul_const_uIcc Set.preimage_mul_const_uIcc
@[simp]
theorem preimage_const_mul_uIcc (ha : a ≠ 0) (b c : α) :
(a * ·) ⁻¹' [[b, c]] = [[b / a, c / a]] := by
simp only [← preimage_mul_const_uIcc ha, mul_comm]
#align set.preimage_const_mul_uIcc Set.preimage_const_mul_uIcc
@[simp]
theorem preimage_div_const_uIcc (ha : a ≠ 0) (b c : α) :
(fun x => x / a) ⁻¹' [[b, c]] = [[b * a, c * a]] := by
simp only [div_eq_mul_inv, preimage_mul_const_uIcc (inv_ne_zero ha), inv_inv]
#align set.preimage_div_const_uIcc Set.preimage_div_const_uIcc
@[simp]
theorem image_mul_const_uIcc (a b c : α) : (· * a) '' [[b, c]] = [[b * a, c * a]] :=
if ha : a = 0 then by simp [ha]
else calc
(fun x => x * a) '' [[b, c]] = (· * a⁻¹) ⁻¹' [[b, c]] :=
(Units.mk0 a ha).mulRight.image_eq_preimage _
_ = (fun x => x / a) ⁻¹' [[b, c]] := by simp only [div_eq_mul_inv]
_ = [[b * a, c * a]] := preimage_div_const_uIcc ha _ _
#align set.image_mul_const_uIcc Set.image_mul_const_uIcc
@[simp]
theorem image_const_mul_uIcc (a b c : α) : (a * ·) '' [[b, c]] = [[a * b, a * c]] := by
simpa only [mul_comm] using image_mul_const_uIcc a b c
#align set.image_const_mul_uIcc Set.image_const_mul_uIcc
@[simp]
theorem image_div_const_uIcc (a b c : α) : (fun x => x / a) '' [[b, c]] = [[b / a, c / a]] := by
simp only [div_eq_mul_inv, image_mul_const_uIcc]
#align set.image_div_const_uIcc Set.image_div_const_uIcc
theorem image_mul_right_Icc' (a b : α) {c : α} (h : 0 < c) :
(fun x => x * c) '' Icc a b = Icc (a * c) (b * c) :=
((Units.mk0 c h.ne').mulRight.image_eq_preimage _).trans (by simp [h, division_def])
#align set.image_mul_right_Icc' Set.image_mul_right_Icc'
| Mathlib/Data/Set/Pointwise/Interval.lean | 818 | 823 | theorem image_mul_right_Icc {a b c : α} (hab : a ≤ b) (hc : 0 ≤ c) :
(fun x => x * c) '' Icc a b = Icc (a * c) (b * c) := by |
cases eq_or_lt_of_le hc
· subst c
simp [(nonempty_Icc.2 hab).image_const]
exact image_mul_right_Icc' a b ‹0 < c›
|
import Mathlib.Analysis.Seminorm
import Mathlib.Topology.Algebra.Equicontinuity
import Mathlib.Topology.MetricSpace.Equicontinuity
import Mathlib.Topology.Algebra.FilterBasis
import Mathlib.Topology.Algebra.Module.LocallyConvex
#align_import analysis.locally_convex.with_seminorms from "leanprover-community/mathlib"@"b31173ee05c911d61ad6a05bd2196835c932e0ec"
open NormedField Set Seminorm TopologicalSpace Filter List
open NNReal Pointwise Topology Uniformity
variable {𝕜 𝕜₂ 𝕝 𝕝₂ E F G ι ι' : Type*}
section FilterBasis
variable [NormedField 𝕜] [AddCommGroup E] [Module 𝕜 E]
variable (𝕜 E ι)
abbrev SeminormFamily :=
ι → Seminorm 𝕜 E
#align seminorm_family SeminormFamily
variable {𝕜 E ι}
section Bounded
namespace Seminorm
variable [NormedField 𝕜] [AddCommGroup E] [Module 𝕜 E]
variable [NormedField 𝕜₂] [AddCommGroup F] [Module 𝕜₂ F]
variable {σ₁₂ : 𝕜 →+* 𝕜₂} [RingHomIsometric σ₁₂]
-- Todo: This should be phrased entirely in terms of the von Neumann bornology.
def IsBounded (p : ι → Seminorm 𝕜 E) (q : ι' → Seminorm 𝕜₂ F) (f : E →ₛₗ[σ₁₂] F) : Prop :=
∀ i, ∃ s : Finset ι, ∃ C : ℝ≥0, (q i).comp f ≤ C • s.sup p
#align seminorm.is_bounded Seminorm.IsBounded
theorem isBounded_const (ι' : Type*) [Nonempty ι'] {p : ι → Seminorm 𝕜 E} {q : Seminorm 𝕜₂ F}
(f : E →ₛₗ[σ₁₂] F) :
IsBounded p (fun _ : ι' => q) f ↔ ∃ (s : Finset ι) (C : ℝ≥0), q.comp f ≤ C • s.sup p := by
simp only [IsBounded, forall_const]
#align seminorm.is_bounded_const Seminorm.isBounded_const
theorem const_isBounded (ι : Type*) [Nonempty ι] {p : Seminorm 𝕜 E} {q : ι' → Seminorm 𝕜₂ F}
(f : E →ₛₗ[σ₁₂] F) : IsBounded (fun _ : ι => p) q f ↔ ∀ i, ∃ C : ℝ≥0, (q i).comp f ≤ C • p := by
constructor <;> intro h i
· rcases h i with ⟨s, C, h⟩
exact ⟨C, le_trans h (smul_le_smul (Finset.sup_le fun _ _ => le_rfl) le_rfl)⟩
use {Classical.arbitrary ι}
simp only [h, Finset.sup_singleton]
#align seminorm.const_is_bounded Seminorm.const_isBounded
| Mathlib/Analysis/LocallyConvex/WithSeminorms.lean | 241 | 256 | theorem isBounded_sup {p : ι → Seminorm 𝕜 E} {q : ι' → Seminorm 𝕜₂ F} {f : E →ₛₗ[σ₁₂] F}
(hf : IsBounded p q f) (s' : Finset ι') :
∃ (C : ℝ≥0) (s : Finset ι), (s'.sup q).comp f ≤ C • s.sup p := by |
classical
obtain rfl | _ := s'.eq_empty_or_nonempty
· exact ⟨1, ∅, by simp [Seminorm.bot_eq_zero]⟩
choose fₛ fC hf using hf
use s'.card • s'.sup fC, Finset.biUnion s' fₛ
have hs : ∀ i : ι', i ∈ s' → (q i).comp f ≤ s'.sup fC • (Finset.biUnion s' fₛ).sup p := by
intro i hi
refine (hf i).trans (smul_le_smul ?_ (Finset.le_sup hi))
exact Finset.sup_mono (Finset.subset_biUnion_of_mem fₛ hi)
refine (comp_mono f (finset_sup_le_sum q s')).trans ?_
simp_rw [← pullback_apply, map_sum, pullback_apply]
refine (Finset.sum_le_sum hs).trans ?_
rw [Finset.sum_const, smul_assoc]
|
import Mathlib.Data.Set.Prod
import Mathlib.Logic.Equiv.Fin
import Mathlib.ModelTheory.LanguageMap
#align_import model_theory.syntax from "leanprover-community/mathlib"@"d565b3df44619c1498326936be16f1a935df0728"
universe u v w u' v'
namespace FirstOrder
namespace Language
variable (L : Language.{u, v}) {L' : Language}
variable {M : Type w} {N P : Type*} [L.Structure M] [L.Structure N] [L.Structure P]
variable {α : Type u'} {β : Type v'} {γ : Type*}
open FirstOrder
open Structure Fin
inductive Term (α : Type u') : Type max u u'
| var : α → Term α
| func : ∀ {l : ℕ} (_f : L.Functions l) (_ts : Fin l → Term α), Term α
#align first_order.language.term FirstOrder.Language.Term
export Term (var func)
variable {L}
namespace Term
open Finset
@[simp]
def varFinset [DecidableEq α] : L.Term α → Finset α
| var i => {i}
| func _f ts => univ.biUnion fun i => (ts i).varFinset
#align first_order.language.term.var_finset FirstOrder.Language.Term.varFinset
-- Porting note: universes in different order
@[simp]
def varFinsetLeft [DecidableEq α] : L.Term (Sum α β) → Finset α
| var (Sum.inl i) => {i}
| var (Sum.inr _i) => ∅
| func _f ts => univ.biUnion fun i => (ts i).varFinsetLeft
#align first_order.language.term.var_finset_left FirstOrder.Language.Term.varFinsetLeft
-- Porting note: universes in different order
@[simp]
def relabel (g : α → β) : L.Term α → L.Term β
| var i => var (g i)
| func f ts => func f fun {i} => (ts i).relabel g
#align first_order.language.term.relabel FirstOrder.Language.Term.relabel
theorem relabel_id (t : L.Term α) : t.relabel id = t := by
induction' t with _ _ _ _ ih
· rfl
· simp [ih]
#align first_order.language.term.relabel_id FirstOrder.Language.Term.relabel_id
@[simp]
theorem relabel_id_eq_id : (Term.relabel id : L.Term α → L.Term α) = id :=
funext relabel_id
#align first_order.language.term.relabel_id_eq_id FirstOrder.Language.Term.relabel_id_eq_id
@[simp]
| Mathlib/ModelTheory/Syntax.lean | 119 | 123 | theorem relabel_relabel (f : α → β) (g : β → γ) (t : L.Term α) :
(t.relabel f).relabel g = t.relabel (g ∘ f) := by |
induction' t with _ _ _ _ ih
· rfl
· simp [ih]
|
import Mathlib.RingTheory.Ideal.QuotientOperations
import Mathlib.RingTheory.Localization.Basic
#align_import ring_theory.localization.ideal from "leanprover-community/mathlib"@"e7f0ddbf65bd7181a85edb74b64bdc35ba4bdc74"
namespace IsLocalization
section CommSemiring
variable {R : Type*} [CommSemiring R] (M : Submonoid R) (S : Type*) [CommSemiring S]
variable [Algebra R S] [IsLocalization M S]
private def map_ideal (I : Ideal R) : Ideal S where
carrier := { z : S | ∃ x : I × M, z * algebraMap R S x.2 = algebraMap R S x.1 }
zero_mem' := ⟨⟨0, 1⟩, by simp⟩
add_mem' := by
rintro a b ⟨a', ha⟩ ⟨b', hb⟩
let Z : { x // x ∈ I } := ⟨(a'.2 : R) * (b'.1 : R) + (b'.2 : R) * (a'.1 : R),
I.add_mem (I.mul_mem_left _ b'.1.2) (I.mul_mem_left _ a'.1.2)⟩
use ⟨Z, a'.2 * b'.2⟩
simp only [RingHom.map_add, Submodule.coe_mk, Submonoid.coe_mul, RingHom.map_mul]
rw [add_mul, ← mul_assoc a, ha, mul_comm (algebraMap R S a'.2) (algebraMap R S b'.2), ←
mul_assoc b, hb]
ring
smul_mem' := by
rintro c x ⟨x', hx⟩
obtain ⟨c', hc⟩ := IsLocalization.surj M c
let Z : { x // x ∈ I } := ⟨c'.1 * x'.1, I.mul_mem_left c'.1 x'.1.2⟩
use ⟨Z, c'.2 * x'.2⟩
simp only [← hx, ← hc, smul_eq_mul, Submodule.coe_mk, Submonoid.coe_mul, RingHom.map_mul]
ring
-- Porting note: removed #align declaration since it is a private def
| Mathlib/RingTheory/Localization/Ideal.lean | 53 | 64 | theorem mem_map_algebraMap_iff {I : Ideal R} {z} : z ∈ Ideal.map (algebraMap R S) I ↔
∃ x : I × M, z * algebraMap R S x.2 = algebraMap R S x.1 := by |
constructor
· change _ → z ∈ map_ideal M S I
refine fun h => Ideal.mem_sInf.1 h fun z hz => ?_
obtain ⟨y, hy⟩ := hz
let Z : { x // x ∈ I } := ⟨y, hy.left⟩
use ⟨Z, 1⟩
simp [hy.right]
· rintro ⟨⟨a, s⟩, h⟩
rw [← Ideal.unit_mul_mem_iff_mem _ (map_units S s), mul_comm]
exact h.symm ▸ Ideal.mem_map_of_mem _ a.2
|
import Mathlib.Analysis.BoxIntegral.Partition.SubboxInduction
import Mathlib.Analysis.BoxIntegral.Partition.Split
#align_import analysis.box_integral.partition.filter from "leanprover-community/mathlib"@"92ca63f0fb391a9ca5f22d2409a6080e786d99f7"
open Set Function Filter Metric Finset Bool
open scoped Classical
open Topology Filter NNReal
noncomputable section
namespace BoxIntegral
variable {ι : Type*} [Fintype ι] {I J : Box ι} {c c₁ c₂ : ℝ≥0} {r r₁ r₂ : (ι → ℝ) → Ioi (0 : ℝ)}
{π π₁ π₂ : TaggedPrepartition I}
open TaggedPrepartition
@[ext]
structure IntegrationParams : Type where
(bRiemann bHenstock bDistortion : Bool)
#align box_integral.integration_params BoxIntegral.IntegrationParams
variable {l l₁ l₂ : IntegrationParams}
namespace IntegrationParams
def equivProd : IntegrationParams ≃ Bool × Boolᵒᵈ × Boolᵒᵈ where
toFun l := ⟨l.1, OrderDual.toDual l.2, OrderDual.toDual l.3⟩
invFun l := ⟨l.1, OrderDual.ofDual l.2.1, OrderDual.ofDual l.2.2⟩
left_inv _ := rfl
right_inv _ := rfl
#align box_integral.integration_params.equiv_prod BoxIntegral.IntegrationParams.equivProd
instance : PartialOrder IntegrationParams :=
PartialOrder.lift equivProd equivProd.injective
def isoProd : IntegrationParams ≃o Bool × Boolᵒᵈ × Boolᵒᵈ :=
⟨equivProd, Iff.rfl⟩
#align box_integral.integration_params.iso_prod BoxIntegral.IntegrationParams.isoProd
instance : BoundedOrder IntegrationParams :=
isoProd.symm.toGaloisInsertion.liftBoundedOrder
instance : Inhabited IntegrationParams :=
⟨⊥⟩
instance : DecidableRel ((· ≤ ·) : IntegrationParams → IntegrationParams → Prop) :=
fun _ _ => And.decidable
instance : DecidableEq IntegrationParams :=
fun x y => decidable_of_iff _ (IntegrationParams.ext_iff x y).symm
def Riemann : IntegrationParams where
bRiemann := true
bHenstock := true
bDistortion := false
set_option linter.uppercaseLean3 false in
#align box_integral.integration_params.Riemann BoxIntegral.IntegrationParams.Riemann
def Henstock : IntegrationParams :=
⟨false, true, false⟩
set_option linter.uppercaseLean3 false in
#align box_integral.integration_params.Henstock BoxIntegral.IntegrationParams.Henstock
def McShane : IntegrationParams :=
⟨false, false, false⟩
set_option linter.uppercaseLean3 false in
#align box_integral.integration_params.McShane BoxIntegral.IntegrationParams.McShane
def GP : IntegrationParams := ⊥
set_option linter.uppercaseLean3 false in
#align box_integral.integration_params.GP BoxIntegral.IntegrationParams.GP
theorem henstock_le_riemann : Henstock ≤ Riemann := by trivial
set_option linter.uppercaseLean3 false in
#align box_integral.integration_params.Henstock_le_Riemann BoxIntegral.IntegrationParams.henstock_le_riemann
theorem henstock_le_mcShane : Henstock ≤ McShane := by trivial
set_option linter.uppercaseLean3 false in
#align box_integral.integration_params.Henstock_le_McShane BoxIntegral.IntegrationParams.henstock_le_mcShane
theorem gp_le : GP ≤ l :=
bot_le
set_option linter.uppercaseLean3 false in
#align box_integral.integration_params.GP_le BoxIntegral.IntegrationParams.gp_le
structure MemBaseSet (l : IntegrationParams) (I : Box ι) (c : ℝ≥0) (r : (ι → ℝ) → Ioi (0 : ℝ))
(π : TaggedPrepartition I) : Prop where
protected isSubordinate : π.IsSubordinate r
protected isHenstock : l.bHenstock → π.IsHenstock
protected distortion_le : l.bDistortion → π.distortion ≤ c
protected exists_compl : l.bDistortion → ∃ π' : Prepartition I,
π'.iUnion = ↑I \ π.iUnion ∧ π'.distortion ≤ c
#align box_integral.integration_params.mem_base_set BoxIntegral.IntegrationParams.MemBaseSet
def RCond {ι : Type*} (l : IntegrationParams) (r : (ι → ℝ) → Ioi (0 : ℝ)) : Prop :=
l.bRiemann → ∀ x, r x = r 0
#align box_integral.integration_params.r_cond BoxIntegral.IntegrationParams.RCond
def toFilterDistortion (l : IntegrationParams) (I : Box ι) (c : ℝ≥0) :
Filter (TaggedPrepartition I) :=
⨅ (r : (ι → ℝ) → Ioi (0 : ℝ)) (_ : l.RCond r), 𝓟 { π | l.MemBaseSet I c r π }
#align box_integral.integration_params.to_filter_distortion BoxIntegral.IntegrationParams.toFilterDistortion
def toFilter (l : IntegrationParams) (I : Box ι) : Filter (TaggedPrepartition I) :=
⨆ c : ℝ≥0, l.toFilterDistortion I c
#align box_integral.integration_params.to_filter BoxIntegral.IntegrationParams.toFilter
def toFilterDistortioniUnion (l : IntegrationParams) (I : Box ι) (c : ℝ≥0) (π₀ : Prepartition I) :=
l.toFilterDistortion I c ⊓ 𝓟 { π | π.iUnion = π₀.iUnion }
#align box_integral.integration_params.to_filter_distortion_Union BoxIntegral.IntegrationParams.toFilterDistortioniUnion
def toFilteriUnion (l : IntegrationParams) (I : Box ι) (π₀ : Prepartition I) :=
⨆ c : ℝ≥0, l.toFilterDistortioniUnion I c π₀
#align box_integral.integration_params.to_filter_Union BoxIntegral.IntegrationParams.toFilteriUnion
theorem rCond_of_bRiemann_eq_false {ι} (l : IntegrationParams) (hl : l.bRiemann = false)
{r : (ι → ℝ) → Ioi (0 : ℝ)} : l.RCond r := by
simp [RCond, hl]
set_option linter.uppercaseLean3 false in
#align box_integral.integration_params.r_cond_of_bRiemann_eq_ff BoxIntegral.IntegrationParams.rCond_of_bRiemann_eq_false
theorem toFilter_inf_iUnion_eq (l : IntegrationParams) (I : Box ι) (π₀ : Prepartition I) :
l.toFilter I ⊓ 𝓟 { π | π.iUnion = π₀.iUnion } = l.toFilteriUnion I π₀ :=
(iSup_inf_principal _ _).symm
#align box_integral.integration_params.to_filter_inf_Union_eq BoxIntegral.IntegrationParams.toFilter_inf_iUnion_eq
theorem MemBaseSet.mono' (I : Box ι) (h : l₁ ≤ l₂) (hc : c₁ ≤ c₂) {π : TaggedPrepartition I}
(hr : ∀ J ∈ π, r₁ (π.tag J) ≤ r₂ (π.tag J)) (hπ : l₁.MemBaseSet I c₁ r₁ π) :
l₂.MemBaseSet I c₂ r₂ π :=
⟨hπ.1.mono' hr, fun h₂ => hπ.2 (le_iff_imp.1 h.2.1 h₂),
fun hD => (hπ.3 (le_iff_imp.1 h.2.2 hD)).trans hc,
fun hD => (hπ.4 (le_iff_imp.1 h.2.2 hD)).imp fun _ hπ => ⟨hπ.1, hπ.2.trans hc⟩⟩
#align box_integral.integration_params.mem_base_set.mono' BoxIntegral.IntegrationParams.MemBaseSet.mono'
@[mono]
theorem MemBaseSet.mono (I : Box ι) (h : l₁ ≤ l₂) (hc : c₁ ≤ c₂) {π : TaggedPrepartition I}
(hr : ∀ x ∈ Box.Icc I, r₁ x ≤ r₂ x) (hπ : l₁.MemBaseSet I c₁ r₁ π) : l₂.MemBaseSet I c₂ r₂ π :=
hπ.mono' I h hc fun J _ => hr _ <| π.tag_mem_Icc J
#align box_integral.integration_params.mem_base_set.mono BoxIntegral.IntegrationParams.MemBaseSet.mono
theorem MemBaseSet.exists_common_compl (h₁ : l.MemBaseSet I c₁ r₁ π₁) (h₂ : l.MemBaseSet I c₂ r₂ π₂)
(hU : π₁.iUnion = π₂.iUnion) :
∃ π : Prepartition I, π.iUnion = ↑I \ π₁.iUnion ∧
(l.bDistortion → π.distortion ≤ c₁) ∧ (l.bDistortion → π.distortion ≤ c₂) := by
wlog hc : c₁ ≤ c₂ with H
· simpa [hU, _root_.and_comm] using
@H _ _ I J c c₂ c₁ r r₂ r₁ π π₂ π₁ _ l₂ l₁ h₂ h₁ hU.symm (le_of_not_le hc)
by_cases hD : (l.bDistortion : Prop)
· rcases h₁.4 hD with ⟨π, hπU, hπc⟩
exact ⟨π, hπU, fun _ => hπc, fun _ => hπc.trans hc⟩
· exact ⟨π₁.toPrepartition.compl, π₁.toPrepartition.iUnion_compl,
fun h => (hD h).elim, fun h => (hD h).elim⟩
#align box_integral.integration_params.mem_base_set.exists_common_compl BoxIntegral.IntegrationParams.MemBaseSet.exists_common_compl
protected theorem MemBaseSet.unionComplToSubordinate (hπ₁ : l.MemBaseSet I c r₁ π₁)
(hle : ∀ x ∈ Box.Icc I, r₂ x ≤ r₁ x) {π₂ : Prepartition I} (hU : π₂.iUnion = ↑I \ π₁.iUnion)
(hc : l.bDistortion → π₂.distortion ≤ c) :
l.MemBaseSet I c r₁ (π₁.unionComplToSubordinate π₂ hU r₂) :=
⟨hπ₁.1.disjUnion ((π₂.isSubordinate_toSubordinate r₂).mono hle) _,
fun h => (hπ₁.2 h).disjUnion (π₂.isHenstock_toSubordinate _) _,
fun h => (distortion_unionComplToSubordinate _ _ _ _).trans_le (max_le (hπ₁.3 h) (hc h)),
fun _ => ⟨⊥, by simp⟩⟩
#align box_integral.integration_params.mem_base_set.union_compl_to_subordinate BoxIntegral.IntegrationParams.MemBaseSet.unionComplToSubordinate
protected theorem MemBaseSet.filter (hπ : l.MemBaseSet I c r π) (p : Box ι → Prop) :
l.MemBaseSet I c r (π.filter p) := by
refine ⟨fun J hJ => hπ.1 J (π.mem_filter.1 hJ).1, fun hH J hJ => hπ.2 hH J (π.mem_filter.1 hJ).1,
fun hD => (distortion_filter_le _ _).trans (hπ.3 hD), fun hD => ?_⟩
rcases hπ.4 hD with ⟨π₁, hπ₁U, hc⟩
set π₂ := π.filter fun J => ¬p J
have : Disjoint π₁.iUnion π₂.iUnion := by
simpa [π₂, hπ₁U] using disjoint_sdiff_self_left.mono_right sdiff_le
refine ⟨π₁.disjUnion π₂.toPrepartition this, ?_, ?_⟩
· suffices ↑I \ π.iUnion ∪ π.iUnion \ (π.filter p).iUnion = ↑I \ (π.filter p).iUnion by
simp [π₂, *]
have h : (π.filter p).iUnion ⊆ π.iUnion :=
biUnion_subset_biUnion_left (Finset.filter_subset _ _)
ext x
fconstructor
· rintro (⟨hxI, hxπ⟩ | ⟨hxπ, hxp⟩)
exacts [⟨hxI, mt (@h x) hxπ⟩, ⟨π.iUnion_subset hxπ, hxp⟩]
· rintro ⟨hxI, hxp⟩
by_cases hxπ : x ∈ π.iUnion
exacts [Or.inr ⟨hxπ, hxp⟩, Or.inl ⟨hxI, hxπ⟩]
· have : (π.filter fun J => ¬p J).distortion ≤ c := (distortion_filter_le _ _).trans (hπ.3 hD)
simpa [hc]
#align box_integral.integration_params.mem_base_set.filter BoxIntegral.IntegrationParams.MemBaseSet.filter
theorem biUnionTagged_memBaseSet {π : Prepartition I} {πi : ∀ J, TaggedPrepartition J}
(h : ∀ J ∈ π, l.MemBaseSet J c r (πi J)) (hp : ∀ J ∈ π, (πi J).IsPartition)
(hc : l.bDistortion → π.compl.distortion ≤ c) : l.MemBaseSet I c r (π.biUnionTagged πi) := by
refine ⟨TaggedPrepartition.isSubordinate_biUnionTagged.2 fun J hJ => (h J hJ).1,
fun hH => TaggedPrepartition.isHenstock_biUnionTagged.2 fun J hJ => (h J hJ).2 hH,
fun hD => ?_, fun hD => ?_⟩
· rw [Prepartition.distortion_biUnionTagged, Finset.sup_le_iff]
exact fun J hJ => (h J hJ).3 hD
· refine ⟨_, ?_, hc hD⟩
rw [π.iUnion_compl, ← π.iUnion_biUnion_partition hp]
rfl
#align box_integral.integration_params.bUnion_tagged_mem_base_set BoxIntegral.IntegrationParams.biUnionTagged_memBaseSet
@[mono]
theorem RCond.mono {ι : Type*} {r : (ι → ℝ) → Ioi (0 : ℝ)} (h : l₁ ≤ l₂) (hr : l₂.RCond r) :
l₁.RCond r :=
fun hR => hr (le_iff_imp.1 h.1 hR)
#align box_integral.integration_params.r_cond.mono BoxIntegral.IntegrationParams.RCond.mono
nonrec theorem RCond.min {ι : Type*} {r₁ r₂ : (ι → ℝ) → Ioi (0 : ℝ)} (h₁ : l.RCond r₁)
(h₂ : l.RCond r₂) : l.RCond fun x => min (r₁ x) (r₂ x) :=
fun hR x => congr_arg₂ min (h₁ hR x) (h₂ hR x)
#align box_integral.integration_params.r_cond.min BoxIntegral.IntegrationParams.RCond.min
@[mono]
theorem toFilterDistortion_mono (I : Box ι) (h : l₁ ≤ l₂) (hc : c₁ ≤ c₂) :
l₁.toFilterDistortion I c₁ ≤ l₂.toFilterDistortion I c₂ :=
iInf_mono fun _ =>
iInf_mono' fun hr =>
⟨hr.mono h, principal_mono.2 fun _ => MemBaseSet.mono I h hc fun _ _ => le_rfl⟩
#align box_integral.integration_params.to_filter_distortion_mono BoxIntegral.IntegrationParams.toFilterDistortion_mono
@[mono]
theorem toFilter_mono (I : Box ι) {l₁ l₂ : IntegrationParams} (h : l₁ ≤ l₂) :
l₁.toFilter I ≤ l₂.toFilter I :=
iSup_mono fun _ => toFilterDistortion_mono I h le_rfl
#align box_integral.integration_params.to_filter_mono BoxIntegral.IntegrationParams.toFilter_mono
@[mono]
theorem toFilteriUnion_mono (I : Box ι) {l₁ l₂ : IntegrationParams} (h : l₁ ≤ l₂)
(π₀ : Prepartition I) : l₁.toFilteriUnion I π₀ ≤ l₂.toFilteriUnion I π₀ :=
iSup_mono fun _ => inf_le_inf_right _ <| toFilterDistortion_mono _ h le_rfl
#align box_integral.integration_params.to_filter_Union_mono BoxIntegral.IntegrationParams.toFilteriUnion_mono
theorem toFilteriUnion_congr (I : Box ι) (l : IntegrationParams) {π₁ π₂ : Prepartition I}
(h : π₁.iUnion = π₂.iUnion) : l.toFilteriUnion I π₁ = l.toFilteriUnion I π₂ := by
simp only [toFilteriUnion, toFilterDistortioniUnion, h]
#align box_integral.integration_params.to_filter_Union_congr BoxIntegral.IntegrationParams.toFilteriUnion_congr
theorem hasBasis_toFilterDistortion (l : IntegrationParams) (I : Box ι) (c : ℝ≥0) :
(l.toFilterDistortion I c).HasBasis l.RCond fun r => { π | l.MemBaseSet I c r π } :=
hasBasis_biInf_principal'
(fun _ hr₁ _ hr₂ =>
⟨_, hr₁.min hr₂, fun _ => MemBaseSet.mono _ le_rfl le_rfl fun _ _ => min_le_left _ _,
fun _ => MemBaseSet.mono _ le_rfl le_rfl fun _ _ => min_le_right _ _⟩)
⟨fun _ => ⟨1, Set.mem_Ioi.2 zero_lt_one⟩, fun _ _ => rfl⟩
#align box_integral.integration_params.has_basis_to_filter_distortion BoxIntegral.IntegrationParams.hasBasis_toFilterDistortion
theorem hasBasis_toFilterDistortioniUnion (l : IntegrationParams) (I : Box ι) (c : ℝ≥0)
(π₀ : Prepartition I) :
(l.toFilterDistortioniUnion I c π₀).HasBasis l.RCond fun r =>
{ π | l.MemBaseSet I c r π ∧ π.iUnion = π₀.iUnion } :=
(l.hasBasis_toFilterDistortion I c).inf_principal _
#align box_integral.integration_params.has_basis_to_filter_distortion_Union BoxIntegral.IntegrationParams.hasBasis_toFilterDistortioniUnion
theorem hasBasis_toFilteriUnion (l : IntegrationParams) (I : Box ι) (π₀ : Prepartition I) :
(l.toFilteriUnion I π₀).HasBasis (fun r : ℝ≥0 → (ι → ℝ) → Ioi (0 : ℝ) => ∀ c, l.RCond (r c))
fun r => { π | ∃ c, l.MemBaseSet I c (r c) π ∧ π.iUnion = π₀.iUnion } := by
have := fun c => l.hasBasis_toFilterDistortioniUnion I c π₀
simpa only [setOf_and, setOf_exists] using hasBasis_iSup this
#align box_integral.integration_params.has_basis_to_filter_Union BoxIntegral.IntegrationParams.hasBasis_toFilteriUnion
theorem hasBasis_toFilteriUnion_top (l : IntegrationParams) (I : Box ι) :
(l.toFilteriUnion I ⊤).HasBasis (fun r : ℝ≥0 → (ι → ℝ) → Ioi (0 : ℝ) => ∀ c, l.RCond (r c))
fun r => { π | ∃ c, l.MemBaseSet I c (r c) π ∧ π.IsPartition } := by
simpa only [TaggedPrepartition.isPartition_iff_iUnion_eq, Prepartition.iUnion_top] using
l.hasBasis_toFilteriUnion I ⊤
#align box_integral.integration_params.has_basis_to_filter_Union_top BoxIntegral.IntegrationParams.hasBasis_toFilteriUnion_top
theorem hasBasis_toFilter (l : IntegrationParams) (I : Box ι) :
(l.toFilter I).HasBasis (fun r : ℝ≥0 → (ι → ℝ) → Ioi (0 : ℝ) => ∀ c, l.RCond (r c))
fun r => { π | ∃ c, l.MemBaseSet I c (r c) π } := by
simpa only [setOf_exists] using hasBasis_iSup (l.hasBasis_toFilterDistortion I)
#align box_integral.integration_params.has_basis_to_filter BoxIntegral.IntegrationParams.hasBasis_toFilter
| Mathlib/Analysis/BoxIntegral/Partition/Filter.lean | 505 | 519 | theorem tendsto_embedBox_toFilteriUnion_top (l : IntegrationParams) (h : I ≤ J) :
Tendsto (TaggedPrepartition.embedBox I J h) (l.toFilteriUnion I ⊤)
(l.toFilteriUnion J (Prepartition.single J I h)) := by |
simp only [toFilteriUnion, tendsto_iSup]; intro c
set π₀ := Prepartition.single J I h
refine le_iSup_of_le (max c π₀.compl.distortion) ?_
refine ((l.hasBasis_toFilterDistortioniUnion I c ⊤).tendsto_iff
(l.hasBasis_toFilterDistortioniUnion J _ _)).2 fun r hr => ?_
refine ⟨r, hr, fun π hπ => ?_⟩
rw [mem_setOf_eq, Prepartition.iUnion_top] at hπ
refine ⟨⟨hπ.1.1, hπ.1.2, fun hD => le_trans (hπ.1.3 hD) (le_max_left _ _), fun _ => ?_⟩, ?_⟩
· refine ⟨_, π₀.iUnion_compl.trans ?_, le_max_right _ _⟩
congr 1
exact (Prepartition.iUnion_single h).trans hπ.2.symm
· exact hπ.2.trans (Prepartition.iUnion_single _).symm
|
import Mathlib.Data.ULift
import Mathlib.Data.ZMod.Defs
import Mathlib.SetTheory.Cardinal.PartENat
#align_import set_theory.cardinal.finite from "leanprover-community/mathlib"@"3ff3f2d6a3118b8711063de7111a0d77a53219a8"
set_option autoImplicit true
open Cardinal Function
noncomputable section
variable {α β : Type*}
namespace Nat
protected def card (α : Type*) : ℕ :=
toNat (mk α)
#align nat.card Nat.card
@[simp]
theorem card_eq_fintype_card [Fintype α] : Nat.card α = Fintype.card α :=
mk_toNat_eq_card
#align nat.card_eq_fintype_card Nat.card_eq_fintype_card
theorem _root_.Fintype.card_eq_nat_card {_ : Fintype α} : Fintype.card α = Nat.card α :=
mk_toNat_eq_card.symm
lemma card_eq_finsetCard (s : Finset α) : Nat.card s = s.card := by
simp only [Nat.card_eq_fintype_card, Fintype.card_coe]
lemma card_eq_card_toFinset (s : Set α) [Fintype s] : Nat.card s = s.toFinset.card := by
simp only [← Nat.card_eq_finsetCard, s.mem_toFinset]
lemma card_eq_card_finite_toFinset {s : Set α} (hs : s.Finite) : Nat.card s = hs.toFinset.card := by
simp only [← Nat.card_eq_finsetCard, hs.mem_toFinset]
@[simp] theorem card_of_isEmpty [IsEmpty α] : Nat.card α = 0 := by simp [Nat.card]
#align nat.card_of_is_empty Nat.card_of_isEmpty
@[simp] lemma card_eq_zero_of_infinite [Infinite α] : Nat.card α = 0 := mk_toNat_of_infinite
#align nat.card_eq_zero_of_infinite Nat.card_eq_zero_of_infinite
lemma _root_.Set.Infinite.card_eq_zero {s : Set α} (hs : s.Infinite) : Nat.card s = 0 :=
@card_eq_zero_of_infinite _ hs.to_subtype
lemma card_eq_zero : Nat.card α = 0 ↔ IsEmpty α ∨ Infinite α := by
simp [Nat.card, mk_eq_zero_iff, aleph0_le_mk_iff]
lemma card_ne_zero : Nat.card α ≠ 0 ↔ Nonempty α ∧ Finite α := by simp [card_eq_zero, not_or]
lemma card_pos_iff : 0 < Nat.card α ↔ Nonempty α ∧ Finite α := by
simp [Nat.card, mk_eq_zero_iff, mk_lt_aleph0_iff]
@[simp] lemma card_pos [Nonempty α] [Finite α] : 0 < Nat.card α := card_pos_iff.2 ⟨‹_›, ‹_›⟩
theorem finite_of_card_ne_zero (h : Nat.card α ≠ 0) : Finite α := (card_ne_zero.1 h).2
#align nat.finite_of_card_ne_zero Nat.finite_of_card_ne_zero
theorem card_congr (f : α ≃ β) : Nat.card α = Nat.card β :=
Cardinal.toNat_congr f
#align nat.card_congr Nat.card_congr
lemma card_le_card_of_injective {α : Type u} {β : Type v} [Finite β] (f : α → β)
(hf : Injective f) : Nat.card α ≤ Nat.card β := by
simpa using toNat_le_toNat (lift_mk_le_lift_mk_of_injective hf) (by simp [lt_aleph0_of_finite])
lemma card_le_card_of_surjective {α : Type u} {β : Type v} [Finite α] (f : α → β)
(hf : Surjective f) : Nat.card β ≤ Nat.card α := by
have : lift.{u} #β ≤ lift.{v} #α := mk_le_of_surjective (ULift.map_surjective.2 hf)
simpa using toNat_le_toNat this (by simp [lt_aleph0_of_finite])
theorem card_eq_of_bijective (f : α → β) (hf : Function.Bijective f) : Nat.card α = Nat.card β :=
card_congr (Equiv.ofBijective f hf)
#align nat.card_eq_of_bijective Nat.card_eq_of_bijective
theorem card_eq_of_equiv_fin {α : Type*} {n : ℕ} (f : α ≃ Fin n) : Nat.card α = n := by
simpa only [card_eq_fintype_card, Fintype.card_fin] using card_congr f
#align nat.card_eq_of_equiv_fin Nat.card_eq_of_equiv_fin
def equivFinOfCardPos {α : Type*} (h : Nat.card α ≠ 0) : α ≃ Fin (Nat.card α) := by
cases fintypeOrInfinite α
· simpa only [card_eq_fintype_card] using Fintype.equivFin α
· simp only [card_eq_zero_of_infinite, ne_eq, not_true_eq_false] at h
#align nat.equiv_fin_of_card_pos Nat.equivFinOfCardPos
theorem card_of_subsingleton (a : α) [Subsingleton α] : Nat.card α = 1 := by
letI := Fintype.ofSubsingleton a
rw [card_eq_fintype_card, Fintype.card_ofSubsingleton a]
#align nat.card_of_subsingleton Nat.card_of_subsingleton
-- @[simp] -- Porting note (#10618): simp can prove this
theorem card_unique [Unique α] : Nat.card α = 1 :=
card_of_subsingleton default
#align nat.card_unique Nat.card_unique
theorem card_eq_one_iff_unique : Nat.card α = 1 ↔ Subsingleton α ∧ Nonempty α :=
Cardinal.toNat_eq_one_iff_unique
#align nat.card_eq_one_iff_unique Nat.card_eq_one_iff_unique
theorem card_eq_two_iff : Nat.card α = 2 ↔ ∃ x y : α, x ≠ y ∧ {x, y} = @Set.univ α :=
toNat_eq_ofNat.trans mk_eq_two_iff
#align nat.card_eq_two_iff Nat.card_eq_two_iff
theorem card_eq_two_iff' (x : α) : Nat.card α = 2 ↔ ∃! y, y ≠ x :=
toNat_eq_ofNat.trans (mk_eq_two_iff' x)
#align nat.card_eq_two_iff' Nat.card_eq_two_iff'
@[simp]
theorem card_sum [Finite α] [Finite β] : Nat.card (α ⊕ β) = Nat.card α + Nat.card β := by
have := Fintype.ofFinite α
have := Fintype.ofFinite β
simp_rw [Nat.card_eq_fintype_card, Fintype.card_sum]
@[simp]
theorem card_prod (α β : Type*) : Nat.card (α × β) = Nat.card α * Nat.card β := by
simp only [Nat.card, mk_prod, toNat_mul, toNat_lift]
#align nat.card_prod Nat.card_prod
@[simp]
theorem card_ulift (α : Type*) : Nat.card (ULift α) = Nat.card α :=
card_congr Equiv.ulift
#align nat.card_ulift Nat.card_ulift
@[simp]
theorem card_plift (α : Type*) : Nat.card (PLift α) = Nat.card α :=
card_congr Equiv.plift
#align nat.card_plift Nat.card_plift
| Mathlib/SetTheory/Cardinal/Finite.lean | 187 | 188 | theorem card_pi {β : α → Type*} [Fintype α] : Nat.card (∀ a, β a) = ∏ a, Nat.card (β a) := by |
simp_rw [Nat.card, mk_pi, prod_eq_of_fintype, toNat_lift, map_prod]
|
import Mathlib.Data.Fin.Fin2
import Mathlib.Init.Logic
import Mathlib.Mathport.Notation
import Mathlib.Tactic.TypeStar
#align_import data.vector3 from "leanprover-community/mathlib"@"3d7987cda72abc473c7cdbbb075170e9ac620042"
open Fin2 Nat
universe u
variable {α : Type*} {m n : ℕ}
def Vector3 (α : Type u) (n : ℕ) : Type u :=
Fin2 n → α
#align vector3 Vector3
instance [Inhabited α] : Inhabited (Vector3 α n) where
default := fun _ => default
namespace Vector3
@[match_pattern]
def nil : Vector3 α 0 :=
nofun
#align vector3.nil Vector3.nil
@[match_pattern]
def cons (a : α) (v : Vector3 α n) : Vector3 α (n + 1) := fun i => by
refine i.cases' ?_ ?_
· exact a
· exact v
#align vector3.cons Vector3.cons
section
open Lean
-- Porting note: was
-- scoped notation3 "["(l", "* => foldr (h t => cons h t) nil)"]" => l
scoped macro_rules | `([$l,*]) => `(expand_foldr% (h t => cons h t) nil [$(.ofElems l),*])
-- this is copied from `src/Init/NotationExtra.lean`
@[app_unexpander Vector3.nil] def unexpandNil : Lean.PrettyPrinter.Unexpander
| `($(_)) => `([])
-- this is copied from `src/Init/NotationExtra.lean`
@[app_unexpander Vector3.cons] def unexpandCons : Lean.PrettyPrinter.Unexpander
| `($(_) $x []) => `([$x])
| `($(_) $x [$xs,*]) => `([$x, $xs,*])
| _ => throw ()
end
-- Overloading the usual `::` notation for `List.cons` with `Vector3.cons`.
@[inherit_doc]
scoped notation a " :: " b => cons a b
@[simp]
theorem cons_fz (a : α) (v : Vector3 α n) : (a :: v) fz = a :=
rfl
#align vector3.cons_fz Vector3.cons_fz
@[simp]
theorem cons_fs (a : α) (v : Vector3 α n) (i) : (a :: v) (fs i) = v i :=
rfl
#align vector3.cons_fs Vector3.cons_fs
abbrev nth (i : Fin2 n) (v : Vector3 α n) : α :=
v i
#align vector3.nth Vector3.nth
abbrev ofFn (f : Fin2 n → α) : Vector3 α n :=
f
#align vector3.of_fn Vector3.ofFn
def head (v : Vector3 α (n + 1)) : α :=
v fz
#align vector3.head Vector3.head
def tail (v : Vector3 α (n + 1)) : Vector3 α n := fun i => v (fs i)
#align vector3.tail Vector3.tail
theorem eq_nil (v : Vector3 α 0) : v = [] :=
funext fun i => nomatch i
#align vector3.eq_nil Vector3.eq_nil
theorem cons_head_tail (v : Vector3 α (n + 1)) : (head v :: tail v) = v :=
funext fun i => Fin2.cases' rfl (fun _ => rfl) i
#align vector3.cons_head_tail Vector3.cons_head_tail
@[elab_as_elim] -- Porting note: add `elab_as_elim`
def nilElim {C : Vector3 α 0 → Sort u} (H : C []) (v : Vector3 α 0) : C v := by
rw [eq_nil v]; apply H
#align vector3.nil_elim Vector3.nilElim
@[elab_as_elim] -- Porting note: add `elab_as_elim`
def consElim {C : Vector3 α (n + 1) → Sort u} (H : ∀ (a : α) (t : Vector3 α n), C (a :: t))
(v : Vector3 α (n + 1)) : C v := by rw [← cons_head_tail v]; apply H
#align vector3.cons_elim Vector3.consElim
@[simp]
theorem consElim_cons {C H a t} : @consElim α n C H (a :: t) = H a t :=
rfl
#align vector3.cons_elim_cons Vector3.consElim_cons
@[elab_as_elim]
protected def recOn {C : ∀ {n}, Vector3 α n → Sort u} {n} (v : Vector3 α n) (H0 : C [])
(Hs : ∀ {n} (a) (w : Vector3 α n), C w → C (a :: w)) : C v :=
match n with
| 0 => v.nilElim H0
| _ + 1 => v.consElim fun a t => Hs a t (Vector3.recOn t H0 Hs)
#align vector3.rec_on Vector3.recOn
@[simp]
theorem recOn_nil {C H0 Hs} : @Vector3.recOn α (@C) 0 [] H0 @Hs = H0 :=
rfl
#align vector3.rec_on_nil Vector3.recOn_nil
@[simp]
theorem recOn_cons {C H0 Hs n a v} :
@Vector3.recOn α (@C) (n + 1) (a :: v) H0 @Hs = Hs a v (@Vector3.recOn α (@C) n v H0 @Hs) :=
rfl
#align vector3.rec_on_cons Vector3.recOn_cons
def append (v : Vector3 α m) (w : Vector3 α n) : Vector3 α (n + m) :=
v.recOn w (fun a _ IH => a :: IH)
#align vector3.append Vector3.append
local infixl:65 " +-+ " => Vector3.append
@[simp]
theorem append_nil (w : Vector3 α n) : [] +-+ w = w :=
rfl
#align vector3.append_nil Vector3.append_nil
@[simp]
theorem append_cons (a : α) (v : Vector3 α m) (w : Vector3 α n) : (a :: v) +-+ w = a :: v +-+ w :=
rfl
#align vector3.append_cons Vector3.append_cons
@[simp]
theorem append_left :
∀ {m} (i : Fin2 m) (v : Vector3 α m) {n} (w : Vector3 α n), (v +-+ w) (left n i) = v i
| _, @fz m, v, n, w => v.consElim fun a _t => by simp [*, left]
| _, @fs m i, v, n, w => v.consElim fun _a t => by simp [append_left, left]
#align vector3.append_left Vector3.append_left
@[simp]
theorem append_add :
∀ {m} (v : Vector3 α m) {n} (w : Vector3 α n) (i : Fin2 n), (v +-+ w) (add i m) = w i
| 0, v, n, w, i => rfl
| m + 1, v, n, w, i => v.consElim fun _a t => by simp [append_add, add]
#align vector3.append_add Vector3.append_add
def insert (a : α) (v : Vector3 α n) (i : Fin2 (n + 1)) : Vector3 α (n + 1) := fun j =>
(a :: v) (insertPerm i j)
#align vector3.insert Vector3.insert
@[simp]
theorem insert_fz (a : α) (v : Vector3 α n) : insert a v fz = a :: v := by
refine funext fun j => j.cases' ?_ ?_ <;> intros <;> rfl
#align vector3.insert_fz Vector3.insert_fz
@[simp]
theorem insert_fs (a : α) (b : α) (v : Vector3 α n) (i : Fin2 (n + 1)) :
insert a (b :: v) (fs i) = b :: insert a v i :=
funext fun j => by
refine j.cases' ?_ fun j => ?_ <;> simp [insert, insertPerm]
refine Fin2.cases' ?_ ?_ (insertPerm i j) <;> simp [insertPerm]
#align vector3.insert_fs Vector3.insert_fs
| Mathlib/Data/Vector3.lean | 201 | 215 | theorem append_insert (a : α) (t : Vector3 α m) (v : Vector3 α n) (i : Fin2 (n + 1))
(e : (n + 1) + m = (n + m) + 1) :
insert a (t +-+ v) (Eq.recOn e (i.add m)) = Eq.recOn e (t +-+ insert a v i) := by |
refine Vector3.recOn t (fun e => ?_) (@fun k b t IH _ => ?_) e
· rfl
have e' : (n + 1) + k = (n + k) + 1 := by omega
change
insert a (b :: t +-+ v)
(Eq.recOn (congr_arg (· + 1) e' : _ + 1 = _) (fs (add i k))) =
Eq.recOn (congr_arg (· + 1) e' : _ + 1 = _) (b :: t +-+ insert a v i)
rw [←
(Eq.recOn e' rfl :
fs (Eq.recOn e' (i.add k) : Fin2 ((n + k) + 1)) =
Eq.recOn (congr_arg (· + 1) e' : _ + 1 = _) (fs (i.add k)))]
simp; rw [IH]; exact Eq.recOn e' rfl
|
import Mathlib.Algebra.CharP.Invertible
import Mathlib.Algebra.Order.Invertible
import Mathlib.Algebra.Order.Module.OrderedSMul
import Mathlib.Algebra.Order.Group.Instances
import Mathlib.LinearAlgebra.AffineSpace.Slope
import Mathlib.LinearAlgebra.AffineSpace.Midpoint
import Mathlib.Tactic.FieldSimp
#align_import linear_algebra.affine_space.ordered from "leanprover-community/mathlib"@"78261225eb5cedc61c5c74ecb44e5b385d13b733"
open AffineMap
variable {k E PE : Type*}
section OrderedRing
variable [OrderedRing k] [OrderedAddCommGroup E] [Module k E] [OrderedSMul k E]
variable {a a' b b' : E} {r r' : k}
theorem lineMap_mono_left (ha : a ≤ a') (hr : r ≤ 1) : lineMap a b r ≤ lineMap a' b r := by
simp only [lineMap_apply_module]
exact add_le_add_right (smul_le_smul_of_nonneg_left ha (sub_nonneg.2 hr)) _
#align line_map_mono_left lineMap_mono_left
theorem lineMap_strict_mono_left (ha : a < a') (hr : r < 1) : lineMap a b r < lineMap a' b r := by
simp only [lineMap_apply_module]
exact add_lt_add_right (smul_lt_smul_of_pos_left ha (sub_pos.2 hr)) _
#align line_map_strict_mono_left lineMap_strict_mono_left
theorem lineMap_mono_right (hb : b ≤ b') (hr : 0 ≤ r) : lineMap a b r ≤ lineMap a b' r := by
simp only [lineMap_apply_module]
exact add_le_add_left (smul_le_smul_of_nonneg_left hb hr) _
#align line_map_mono_right lineMap_mono_right
theorem lineMap_strict_mono_right (hb : b < b') (hr : 0 < r) : lineMap a b r < lineMap a b' r := by
simp only [lineMap_apply_module]
exact add_lt_add_left (smul_lt_smul_of_pos_left hb hr) _
#align line_map_strict_mono_right lineMap_strict_mono_right
theorem lineMap_mono_endpoints (ha : a ≤ a') (hb : b ≤ b') (h₀ : 0 ≤ r) (h₁ : r ≤ 1) :
lineMap a b r ≤ lineMap a' b' r :=
(lineMap_mono_left ha h₁).trans (lineMap_mono_right hb h₀)
#align line_map_mono_endpoints lineMap_mono_endpoints
| Mathlib/LinearAlgebra/AffineSpace/Ordered.lean | 77 | 80 | theorem lineMap_strict_mono_endpoints (ha : a < a') (hb : b < b') (h₀ : 0 ≤ r) (h₁ : r ≤ 1) :
lineMap a b r < lineMap a' b' r := by |
rcases h₀.eq_or_lt with (rfl | h₀); · simpa
exact (lineMap_mono_left ha.le h₁).trans_lt (lineMap_strict_mono_right hb h₀)
|
import Mathlib.Data.List.Nodup
#align_import data.prod.tprod from "leanprover-community/mathlib"@"c227d107bbada5d0d9d20287e3282c0a7f1651a0"
open List Function
universe u v
variable {ι : Type u} {α : ι → Type v} {i j : ι} {l : List ι} {f : ∀ i, α i}
namespace List
variable (α)
abbrev TProd (l : List ι) : Type v :=
l.foldr (fun i β => α i × β) PUnit
#align list.tprod List.TProd
variable {α}
namespace TProd
open List
protected def mk : ∀ (l : List ι) (_f : ∀ i, α i), TProd α l
| [] => fun _ => PUnit.unit
| i :: is => fun f => (f i, TProd.mk is f)
#align list.tprod.mk List.TProd.mk
instance [∀ i, Inhabited (α i)] : Inhabited (TProd α l) :=
⟨TProd.mk l default⟩
@[simp]
theorem fst_mk (i : ι) (l : List ι) (f : ∀ i, α i) : (TProd.mk (i :: l) f).1 = f i :=
rfl
#align list.tprod.fst_mk List.TProd.fst_mk
@[simp]
theorem snd_mk (i : ι) (l : List ι) (f : ∀ i, α i) :
(TProd.mk.{u,v} (i :: l) f).2 = TProd.mk.{u,v} l f :=
rfl
#align list.tprod.snd_mk List.TProd.snd_mk
variable [DecidableEq ι]
protected def elim : ∀ {l : List ι} (_ : TProd α l) {i : ι} (_ : i ∈ l), α i
| i :: is, v, j, hj =>
if hji : j = i then by
subst hji
exact v.1
else TProd.elim v.2 ((List.mem_cons.mp hj).resolve_left hji)
#align list.tprod.elim List.TProd.elim
@[simp]
theorem elim_self (v : TProd α (i :: l)) : v.elim (l.mem_cons_self i) = v.1 := by simp [TProd.elim]
#align list.tprod.elim_self List.TProd.elim_self
@[simp]
| Mathlib/Data/Prod/TProd.lean | 94 | 95 | theorem elim_of_ne (hj : j ∈ i :: l) (hji : j ≠ i) (v : TProd α (i :: l)) :
v.elim hj = TProd.elim v.2 ((List.mem_cons.mp hj).resolve_left hji) := by | simp [TProd.elim, hji]
|
import Mathlib.Algebra.CharZero.Lemmas
import Mathlib.Order.Interval.Finset.Basic
#align_import data.int.interval from "leanprover-community/mathlib"@"1d29de43a5ba4662dd33b5cfeecfc2a27a5a8a29"
open Finset Int
namespace Int
instance instLocallyFiniteOrder : LocallyFiniteOrder ℤ where
finsetIcc a b :=
(Finset.range (b + 1 - a).toNat).map <| Nat.castEmbedding.trans <| addLeftEmbedding a
finsetIco a b := (Finset.range (b - a).toNat).map <| Nat.castEmbedding.trans <| addLeftEmbedding a
finsetIoc a b :=
(Finset.range (b - a).toNat).map <| Nat.castEmbedding.trans <| addLeftEmbedding (a + 1)
finsetIoo a b :=
(Finset.range (b - a - 1).toNat).map <| Nat.castEmbedding.trans <| addLeftEmbedding (a + 1)
finset_mem_Icc a b x := by
simp_rw [mem_map, mem_range, Int.lt_toNat, Function.Embedding.trans_apply,
Nat.castEmbedding_apply, addLeftEmbedding_apply]
constructor
· rintro ⟨a, h, rfl⟩
rw [lt_sub_iff_add_lt, Int.lt_add_one_iff, add_comm] at h
exact ⟨Int.le.intro a rfl, h⟩
· rintro ⟨ha, hb⟩
use (x - a).toNat
rw [← lt_add_one_iff] at hb
rw [toNat_sub_of_le ha]
exact ⟨sub_lt_sub_right hb _, add_sub_cancel _ _⟩
finset_mem_Ico a b x := by
simp_rw [mem_map, mem_range, Int.lt_toNat, Function.Embedding.trans_apply,
Nat.castEmbedding_apply, addLeftEmbedding_apply]
constructor
· rintro ⟨a, h, rfl⟩
exact ⟨Int.le.intro a rfl, lt_sub_iff_add_lt'.mp h⟩
· rintro ⟨ha, hb⟩
use (x - a).toNat
rw [toNat_sub_of_le ha]
exact ⟨sub_lt_sub_right hb _, add_sub_cancel _ _⟩
finset_mem_Ioc a b x := by
simp_rw [mem_map, mem_range, Int.lt_toNat, Function.Embedding.trans_apply,
Nat.castEmbedding_apply, addLeftEmbedding_apply]
constructor
· rintro ⟨a, h, rfl⟩
rw [← add_one_le_iff, le_sub_iff_add_le', add_comm _ (1 : ℤ), ← add_assoc] at h
exact ⟨Int.le.intro a rfl, h⟩
· rintro ⟨ha, hb⟩
use (x - (a + 1)).toNat
rw [toNat_sub_of_le ha, ← add_one_le_iff, sub_add, add_sub_cancel_right]
exact ⟨sub_le_sub_right hb _, add_sub_cancel _ _⟩
finset_mem_Ioo a b x := by
simp_rw [mem_map, mem_range, Int.lt_toNat, Function.Embedding.trans_apply,
Nat.castEmbedding_apply, addLeftEmbedding_apply]
constructor
· rintro ⟨a, h, rfl⟩
rw [sub_sub, lt_sub_iff_add_lt'] at h
exact ⟨Int.le.intro a rfl, h⟩
· rintro ⟨ha, hb⟩
use (x - (a + 1)).toNat
rw [toNat_sub_of_le ha, sub_sub]
exact ⟨sub_lt_sub_right hb _, add_sub_cancel _ _⟩
variable (a b : ℤ)
theorem Icc_eq_finset_map :
Icc a b =
(Finset.range (b + 1 - a).toNat).map (Nat.castEmbedding.trans <| addLeftEmbedding a) :=
rfl
#align int.Icc_eq_finset_map Int.Icc_eq_finset_map
theorem Ico_eq_finset_map :
Ico a b = (Finset.range (b - a).toNat).map (Nat.castEmbedding.trans <| addLeftEmbedding a) :=
rfl
#align int.Ico_eq_finset_map Int.Ico_eq_finset_map
theorem Ioc_eq_finset_map :
Ioc a b =
(Finset.range (b - a).toNat).map (Nat.castEmbedding.trans <| addLeftEmbedding (a + 1)) :=
rfl
#align int.Ioc_eq_finset_map Int.Ioc_eq_finset_map
theorem Ioo_eq_finset_map :
Ioo a b =
(Finset.range (b - a - 1).toNat).map (Nat.castEmbedding.trans <| addLeftEmbedding (a + 1)) :=
rfl
#align int.Ioo_eq_finset_map Int.Ioo_eq_finset_map
theorem uIcc_eq_finset_map :
uIcc a b = (range (max a b + 1 - min a b).toNat).map
(Nat.castEmbedding.trans <| addLeftEmbedding <| min a b) := rfl
#align int.uIcc_eq_finset_map Int.uIcc_eq_finset_map
@[simp]
theorem card_Icc : (Icc a b).card = (b + 1 - a).toNat := (card_map _).trans <| card_range _
#align int.card_Icc Int.card_Icc
@[simp]
theorem card_Ico : (Ico a b).card = (b - a).toNat := (card_map _).trans <| card_range _
#align int.card_Ico Int.card_Ico
@[simp]
theorem card_Ioc : (Ioc a b).card = (b - a).toNat := (card_map _).trans <| card_range _
#align int.card_Ioc Int.card_Ioc
@[simp]
theorem card_Ioo : (Ioo a b).card = (b - a - 1).toNat := (card_map _).trans <| card_range _
#align int.card_Ioo Int.card_Ioo
@[simp]
theorem card_uIcc : (uIcc a b).card = (b - a).natAbs + 1 :=
(card_map _).trans <|
Int.ofNat.inj <| by
-- Porting note (#11215): TODO: Restore `int.coe_nat_inj` and remove the `change`
change ((↑) : ℕ → ℤ) _ = ((↑) : ℕ → ℤ) _
rw [card_range, sup_eq_max, inf_eq_min,
Int.toNat_of_nonneg (sub_nonneg_of_le <| le_add_one min_le_max), Int.ofNat_add,
Int.natCast_natAbs, add_comm, add_sub_assoc, max_sub_min_eq_abs, add_comm, Int.ofNat_one]
#align int.card_uIcc Int.card_uIcc
theorem card_Icc_of_le (h : a ≤ b + 1) : ((Icc a b).card : ℤ) = b + 1 - a := by
rw [card_Icc, toNat_sub_of_le h]
#align int.card_Icc_of_le Int.card_Icc_of_le
theorem card_Ico_of_le (h : a ≤ b) : ((Ico a b).card : ℤ) = b - a := by
rw [card_Ico, toNat_sub_of_le h]
#align int.card_Ico_of_le Int.card_Ico_of_le
theorem card_Ioc_of_le (h : a ≤ b) : ((Ioc a b).card : ℤ) = b - a := by
rw [card_Ioc, toNat_sub_of_le h]
#align int.card_Ioc_of_le Int.card_Ioc_of_le
theorem card_Ioo_of_lt (h : a < b) : ((Ioo a b).card : ℤ) = b - a - 1 := by
rw [card_Ioo, sub_sub, toNat_sub_of_le h]
#align int.card_Ioo_of_lt Int.card_Ioo_of_lt
-- Porting note (#11119): removed `simp` attribute because `simpNF` says it can prove it
theorem card_fintype_Icc : Fintype.card (Set.Icc a b) = (b + 1 - a).toNat := by
rw [← card_Icc, Fintype.card_ofFinset]
#align int.card_fintype_Icc Int.card_fintype_Icc
-- Porting note (#11119): removed `simp` attribute because `simpNF` says it can prove it
theorem card_fintype_Ico : Fintype.card (Set.Ico a b) = (b - a).toNat := by
rw [← card_Ico, Fintype.card_ofFinset]
#align int.card_fintype_Ico Int.card_fintype_Ico
-- Porting note (#11119): removed `simp` attribute because `simpNF` says it can prove it
| Mathlib/Data/Int/Interval.lean | 160 | 161 | theorem card_fintype_Ioc : Fintype.card (Set.Ioc a b) = (b - a).toNat := by |
rw [← card_Ioc, Fintype.card_ofFinset]
|
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}
namespace ContinuousLinearMap
variable {B : E →L[𝕜] F →L[𝕜] G} {u : 𝕜 → E} {v : 𝕜 → F} {u' : E} {v' : F}
theorem hasDerivWithinAt_of_bilinear
(hu : HasDerivWithinAt u u' s x) (hv : HasDerivWithinAt v v' s x) :
HasDerivWithinAt (fun x ↦ B (u x) (v x)) (B (u x) v' + B u' (v x)) s x := by
simpa using (B.hasFDerivWithinAt_of_bilinear
hu.hasFDerivWithinAt hv.hasFDerivWithinAt).hasDerivWithinAt
| Mathlib/Analysis/Calculus/Deriv/Mul.lean | 58 | 60 | theorem hasDerivAt_of_bilinear (hu : HasDerivAt u u' x) (hv : HasDerivAt v v' x) :
HasDerivAt (fun x ↦ B (u x) (v x)) (B (u x) v' + B u' (v x)) x := by |
simpa using (B.hasFDerivAt_of_bilinear hu.hasFDerivAt hv.hasFDerivAt).hasDerivAt
|
import Mathlib.Order.Interval.Set.Image
import Mathlib.Order.CompleteLatticeIntervals
import Mathlib.Topology.Order.DenselyOrdered
import Mathlib.Topology.Order.Monotone
#align_import topology.algebra.order.intermediate_value from "leanprover-community/mathlib"@"4c19a16e4b705bf135cf9a80ac18fcc99c438514"
open Filter OrderDual TopologicalSpace Function Set
open Topology Filter
universe u v w
section
variable {X : Type u} {α : Type v} [TopologicalSpace X] [LinearOrder α] [TopologicalSpace α]
[OrderClosedTopology α]
theorem intermediate_value_univ₂ [PreconnectedSpace X] {a b : X} {f g : X → α} (hf : Continuous f)
(hg : Continuous g) (ha : f a ≤ g a) (hb : g b ≤ f b) : ∃ x, f x = g x := by
obtain ⟨x, _, hfg, hgf⟩ : (univ ∩ { x | f x ≤ g x ∧ g x ≤ f x }).Nonempty :=
isPreconnected_closed_iff.1 PreconnectedSpace.isPreconnected_univ _ _ (isClosed_le hf hg)
(isClosed_le hg hf) (fun _ _ => le_total _ _) ⟨a, trivial, ha⟩ ⟨b, trivial, hb⟩
exact ⟨x, le_antisymm hfg hgf⟩
#align intermediate_value_univ₂ intermediate_value_univ₂
theorem intermediate_value_univ₂_eventually₁ [PreconnectedSpace X] {a : X} {l : Filter X} [NeBot l]
{f g : X → α} (hf : Continuous f) (hg : Continuous g) (ha : f a ≤ g a) (he : g ≤ᶠ[l] f) :
∃ x, f x = g x :=
let ⟨_, h⟩ := he.exists; intermediate_value_univ₂ hf hg ha h
#align intermediate_value_univ₂_eventually₁ intermediate_value_univ₂_eventually₁
theorem intermediate_value_univ₂_eventually₂ [PreconnectedSpace X] {l₁ l₂ : Filter X} [NeBot l₁]
[NeBot l₂] {f g : X → α} (hf : Continuous f) (hg : Continuous g) (he₁ : f ≤ᶠ[l₁] g)
(he₂ : g ≤ᶠ[l₂] f) : ∃ x, f x = g x :=
let ⟨_, h₁⟩ := he₁.exists
let ⟨_, h₂⟩ := he₂.exists
intermediate_value_univ₂ hf hg h₁ h₂
#align intermediate_value_univ₂_eventually₂ intermediate_value_univ₂_eventually₂
theorem IsPreconnected.intermediate_value₂ {s : Set X} (hs : IsPreconnected s) {a b : X}
(ha : a ∈ s) (hb : b ∈ s) {f g : X → α} (hf : ContinuousOn f s) (hg : ContinuousOn g s)
(ha' : f a ≤ g a) (hb' : g b ≤ f b) : ∃ x ∈ s, f x = g x :=
let ⟨x, hx⟩ :=
@intermediate_value_univ₂ s α _ _ _ _ (Subtype.preconnectedSpace hs) ⟨a, ha⟩ ⟨b, hb⟩ _ _
(continuousOn_iff_continuous_restrict.1 hf) (continuousOn_iff_continuous_restrict.1 hg) ha'
hb'
⟨x, x.2, hx⟩
#align is_preconnected.intermediate_value₂ IsPreconnected.intermediate_value₂
theorem IsPreconnected.intermediate_value₂_eventually₁ {s : Set X} (hs : IsPreconnected s) {a : X}
{l : Filter X} (ha : a ∈ s) [NeBot l] (hl : l ≤ 𝓟 s) {f g : X → α} (hf : ContinuousOn f s)
(hg : ContinuousOn g s) (ha' : f a ≤ g a) (he : g ≤ᶠ[l] f) : ∃ x ∈ s, f x = g x := by
rw [continuousOn_iff_continuous_restrict] at hf hg
obtain ⟨b, h⟩ :=
@intermediate_value_univ₂_eventually₁ _ _ _ _ _ _ (Subtype.preconnectedSpace hs) ⟨a, ha⟩ _
(comap_coe_neBot_of_le_principal hl) _ _ hf hg ha' (he.comap _)
exact ⟨b, b.prop, h⟩
#align is_preconnected.intermediate_value₂_eventually₁ IsPreconnected.intermediate_value₂_eventually₁
| Mathlib/Topology/Order/IntermediateValue.lean | 115 | 124 | theorem IsPreconnected.intermediate_value₂_eventually₂ {s : Set X} (hs : IsPreconnected s)
{l₁ l₂ : Filter X} [NeBot l₁] [NeBot l₂] (hl₁ : l₁ ≤ 𝓟 s) (hl₂ : l₂ ≤ 𝓟 s) {f g : X → α}
(hf : ContinuousOn f s) (hg : ContinuousOn g s) (he₁ : f ≤ᶠ[l₁] g) (he₂ : g ≤ᶠ[l₂] f) :
∃ x ∈ s, f x = g x := by |
rw [continuousOn_iff_continuous_restrict] at hf hg
obtain ⟨b, h⟩ :=
@intermediate_value_univ₂_eventually₂ _ _ _ _ _ _ (Subtype.preconnectedSpace hs) _ _
(comap_coe_neBot_of_le_principal hl₁) (comap_coe_neBot_of_le_principal hl₂) _ _ hf hg
(he₁.comap _) (he₂.comap _)
exact ⟨b, b.prop, h⟩
|
import Mathlib.Algebra.Group.Subgroup.Basic
import Mathlib.Algebra.Group.Submonoid.Membership
import Mathlib.Data.Finite.Card
#align_import group_theory.subgroup.finite from "leanprover-community/mathlib"@"f93c11933efbc3c2f0299e47b8ff83e9b539cbf6"
variable {G : Type*} [Group G]
variable {A : Type*} [AddGroup A]
namespace Subgroup
section Pi
open Set
variable {η : Type*} {f : η → Type*} [∀ i, Group (f i)]
@[to_additive]
| Mathlib/Algebra/Group/Subgroup/Finite.lean | 195 | 226 | theorem pi_mem_of_mulSingle_mem_aux [DecidableEq η] (I : Finset η) {H : Subgroup (∀ i, f i)}
(x : ∀ i, f i) (h1 : ∀ i, i ∉ I → x i = 1) (h2 : ∀ i, i ∈ I → Pi.mulSingle i (x i) ∈ H) :
x ∈ H := by |
induction' I using Finset.induction_on with i I hnmem ih generalizing x
· convert one_mem H
ext i
exact h1 i (Finset.not_mem_empty i)
· have : x = Function.update x i 1 * Pi.mulSingle i (x i) := by
ext j
by_cases heq : j = i
· subst heq
simp
· simp [heq]
rw [this]
clear this
apply mul_mem
· apply ih <;> clear ih
· intro j hj
by_cases heq : j = i
· subst heq
simp
· simp [heq]
apply h1 j
simpa [heq] using hj
· intro j hj
have : j ≠ i := by
rintro rfl
contradiction
simp only [ne_eq, this, not_false_eq_true, Function.update_noteq]
exact h2 _ (Finset.mem_insert_of_mem hj)
· apply h2
simp
|
import Mathlib.SetTheory.Ordinal.Arithmetic
import Mathlib.SetTheory.Ordinal.Exponential
#align_import set_theory.ordinal.cantor_normal_form from "leanprover-community/mathlib"@"991ff3b5269848f6dd942ae8e9dd3c946035dc8b"
noncomputable section
universe u
open List
namespace Ordinal
@[elab_as_elim]
noncomputable def CNFRec (b : Ordinal) {C : Ordinal → Sort*} (H0 : C 0)
(H : ∀ o, o ≠ 0 → C (o % b ^ log b o) → C o) : ∀ o, C o := fun o ↦ by
by_cases h : o = 0
· rw [h]; exact H0
· exact H o h (CNFRec _ H0 H (o % b ^ log b o))
termination_by o => o
decreasing_by exact mod_opow_log_lt_self b h
set_option linter.uppercaseLean3 false in
#align ordinal.CNF_rec Ordinal.CNFRec
@[simp]
theorem CNFRec_zero {C : Ordinal → Sort*} (b : Ordinal) (H0 : C 0)
(H : ∀ o, o ≠ 0 → C (o % b ^ log b o) → C o) : @CNFRec b C H0 H 0 = H0 := by
rw [CNFRec, dif_pos rfl]
rfl
set_option linter.uppercaseLean3 false in
#align ordinal.CNF_rec_zero Ordinal.CNFRec_zero
theorem CNFRec_pos (b : Ordinal) {o : Ordinal} {C : Ordinal → Sort*} (ho : o ≠ 0) (H0 : C 0)
(H : ∀ o, o ≠ 0 → C (o % b ^ log b o) → C o) :
@CNFRec b C H0 H o = H o ho (@CNFRec b C H0 H _) := by rw [CNFRec, dif_neg ho]
set_option linter.uppercaseLean3 false in
#align ordinal.CNF_rec_pos Ordinal.CNFRec_pos
-- Porting note: unknown attribute @[pp_nodot]
def CNF (b o : Ordinal) : List (Ordinal × Ordinal) :=
CNFRec b [] (fun o _ho IH ↦ (log b o, o / b ^ log b o)::IH) o
set_option linter.uppercaseLean3 false in
#align ordinal.CNF Ordinal.CNF
@[simp]
theorem CNF_zero (b : Ordinal) : CNF b 0 = [] :=
CNFRec_zero b _ _
set_option linter.uppercaseLean3 false in
#align ordinal.CNF_zero Ordinal.CNF_zero
theorem CNF_ne_zero {b o : Ordinal} (ho : o ≠ 0) :
CNF b o = (log b o, o / b ^ log b o)::CNF b (o % b ^ log b o) :=
CNFRec_pos b ho _ _
set_option linter.uppercaseLean3 false in
#align ordinal.CNF_ne_zero Ordinal.CNF_ne_zero
| Mathlib/SetTheory/Ordinal/CantorNormalForm.lean | 93 | 93 | theorem zero_CNF {o : Ordinal} (ho : o ≠ 0) : CNF 0 o = [⟨0, o⟩] := by | simp [CNF_ne_zero ho]
|
import Mathlib.LinearAlgebra.AffineSpace.AffineMap
import Mathlib.Tactic.FieldSimp
#align_import linear_algebra.affine_space.slope from "leanprover-community/mathlib"@"70fd9563a21e7b963887c9360bd29b2393e6225a"
open AffineMap
variable {k E PE : Type*} [Field k] [AddCommGroup E] [Module k E] [AddTorsor E PE]
def slope (f : k → PE) (a b : k) : E :=
(b - a)⁻¹ • (f b -ᵥ f a)
#align slope slope
theorem slope_fun_def (f : k → PE) : slope f = fun a b => (b - a)⁻¹ • (f b -ᵥ f a) :=
rfl
#align slope_fun_def slope_fun_def
theorem slope_def_field (f : k → k) (a b : k) : slope f a b = (f b - f a) / (b - a) :=
(div_eq_inv_mul _ _).symm
#align slope_def_field slope_def_field
theorem slope_fun_def_field (f : k → k) (a : k) : slope f a = fun b => (f b - f a) / (b - a) :=
(div_eq_inv_mul _ _).symm
#align slope_fun_def_field slope_fun_def_field
@[simp]
theorem slope_same (f : k → PE) (a : k) : (slope f a a : E) = 0 := by
rw [slope, sub_self, inv_zero, zero_smul]
#align slope_same slope_same
theorem slope_def_module (f : k → E) (a b : k) : slope f a b = (b - a)⁻¹ • (f b - f a) :=
rfl
#align slope_def_module slope_def_module
@[simp]
theorem sub_smul_slope (f : k → PE) (a b : k) : (b - a) • slope f a b = f b -ᵥ f a := by
rcases eq_or_ne a b with (rfl | hne)
· rw [sub_self, zero_smul, vsub_self]
· rw [slope, smul_inv_smul₀ (sub_ne_zero.2 hne.symm)]
#align sub_smul_slope sub_smul_slope
theorem sub_smul_slope_vadd (f : k → PE) (a b : k) : (b - a) • slope f a b +ᵥ f a = f b := by
rw [sub_smul_slope, vsub_vadd]
#align sub_smul_slope_vadd sub_smul_slope_vadd
@[simp]
| Mathlib/LinearAlgebra/AffineSpace/Slope.lean | 67 | 69 | theorem slope_vadd_const (f : k → E) (c : PE) : (slope fun x => f x +ᵥ c) = slope f := by |
ext a b
simp only [slope, vadd_vsub_vadd_cancel_right, vsub_eq_sub]
|
import Mathlib.Algebra.Group.ConjFinite
import Mathlib.GroupTheory.Abelianization
import Mathlib.GroupTheory.GroupAction.ConjAct
import Mathlib.GroupTheory.GroupAction.Quotient
import Mathlib.GroupTheory.Index
import Mathlib.GroupTheory.SpecificGroups.Dihedral
import Mathlib.Tactic.FieldSimp
import Mathlib.Tactic.LinearCombination
import Mathlib.Tactic.Qify
#align_import group_theory.commuting_probability from "leanprover-community/mathlib"@"dc6c365e751e34d100e80fe6e314c3c3e0fd2988"
noncomputable section
open scoped Classical
open Fintype
variable (M : Type*) [Mul M]
def commProb : ℚ :=
Nat.card { p : M × M // Commute p.1 p.2 } / (Nat.card M : ℚ) ^ 2
#align comm_prob commProb
theorem commProb_def :
commProb M = Nat.card { p : M × M // Commute p.1 p.2 } / (Nat.card M : ℚ) ^ 2 :=
rfl
#align comm_prob_def commProb_def
theorem commProb_prod (M' : Type*) [Mul M'] : commProb (M × M') = commProb M * commProb M' := by
simp_rw [commProb_def, div_mul_div_comm, Nat.card_prod, Nat.cast_mul, mul_pow, ← Nat.cast_mul,
← Nat.card_prod, Commute, SemiconjBy, Prod.ext_iff]
congr 2
exact Nat.card_congr ⟨fun x => ⟨⟨⟨x.1.1.1, x.1.2.1⟩, x.2.1⟩, ⟨⟨x.1.1.2, x.1.2.2⟩, x.2.2⟩⟩,
fun x => ⟨⟨⟨x.1.1.1, x.2.1.1⟩, ⟨x.1.1.2, x.2.1.2⟩⟩, ⟨x.1.2, x.2.2⟩⟩, fun x => rfl, fun x => rfl⟩
theorem commProb_pi {α : Type*} (i : α → Type*) [Fintype α] [∀ a, Mul (i a)] :
commProb (∀ a, i a) = ∏ a, commProb (i a) := by
simp_rw [commProb_def, Finset.prod_div_distrib, Finset.prod_pow, ← Nat.cast_prod,
← Nat.card_pi, Commute, SemiconjBy, Function.funext_iff]
congr 2
exact Nat.card_congr ⟨fun x a => ⟨⟨x.1.1 a, x.1.2 a⟩, x.2 a⟩, fun x => ⟨⟨fun a => (x a).1.1,
fun a => (x a).1.2⟩, fun a => (x a).2⟩, fun x => rfl, fun x => rfl⟩
theorem commProb_function {α β : Type*} [Fintype α] [Mul β] :
commProb (α → β) = (commProb β) ^ Fintype.card α := by
rw [commProb_pi, Finset.prod_const, Finset.card_univ]
@[simp]
theorem commProb_eq_zero_of_infinite [Infinite M] : commProb M = 0 :=
div_eq_zero_iff.2 (Or.inl (Nat.cast_eq_zero.2 Nat.card_eq_zero_of_infinite))
variable [Finite M]
theorem commProb_pos [h : Nonempty M] : 0 < commProb M :=
h.elim fun x ↦
div_pos (Nat.cast_pos.mpr (Finite.card_pos_iff.mpr ⟨⟨(x, x), rfl⟩⟩))
(pow_pos (Nat.cast_pos.mpr Finite.card_pos) 2)
#align comm_prob_pos commProb_pos
theorem commProb_le_one : commProb M ≤ 1 := by
refine div_le_one_of_le ?_ (sq_nonneg (Nat.card M : ℚ))
rw [← Nat.cast_pow, Nat.cast_le, sq, ← Nat.card_prod]
apply Finite.card_subtype_le
#align comm_prob_le_one commProb_le_one
variable {M}
theorem commProb_eq_one_iff [h : Nonempty M] :
commProb M = 1 ↔ Commutative ((· * ·) : M → M → M) := by
haveI := Fintype.ofFinite M
rw [commProb, ← Set.coe_setOf, Nat.card_eq_fintype_card, Nat.card_eq_fintype_card]
rw [div_eq_one_iff_eq, ← Nat.cast_pow, Nat.cast_inj, sq, ← card_prod,
set_fintype_card_eq_univ_iff, Set.eq_univ_iff_forall]
· exact ⟨fun h x y ↦ h (x, y), fun h x ↦ h x.1 x.2⟩
· exact pow_ne_zero 2 (Nat.cast_ne_zero.mpr card_ne_zero)
#align comm_prob_eq_one_iff commProb_eq_one_iff
variable (G : Type*) [Group G]
theorem commProb_def' : commProb G = Nat.card (ConjClasses G) / Nat.card G := by
rw [commProb, card_comm_eq_card_conjClasses_mul_card, Nat.cast_mul, sq]
by_cases h : (Nat.card G : ℚ) = 0
· rw [h, zero_mul, div_zero, div_zero]
· exact mul_div_mul_right _ _ h
#align comm_prob_def' commProb_def'
variable {G}
variable [Finite G] (H : Subgroup G)
theorem Subgroup.commProb_subgroup_le : commProb H ≤ commProb G * (H.index : ℚ) ^ 2 := by
rw [commProb_def, commProb_def, div_le_iff, mul_assoc, ← mul_pow, ← Nat.cast_mul,
mul_comm H.index, H.card_mul_index, div_mul_cancel₀, Nat.cast_le]
· refine Finite.card_le_of_injective (fun p ↦ ⟨⟨p.1.1, p.1.2⟩, Subtype.ext_iff.mp p.2⟩) ?_
exact fun p q h ↦ by simpa only [Subtype.ext_iff, Prod.ext_iff] using h
· exact pow_ne_zero 2 (Nat.cast_ne_zero.mpr Finite.card_pos.ne')
· exact pow_pos (Nat.cast_pos.mpr Finite.card_pos) 2
#align subgroup.comm_prob_subgroup_le Subgroup.commProb_subgroup_le
| Mathlib/GroupTheory/CommutingProbability.lean | 119 | 128 | theorem Subgroup.commProb_quotient_le [H.Normal] : commProb (G ⧸ H) ≤ commProb G * Nat.card H := by |
/- After rewriting with `commProb_def'`, we reduce to showing that `G` has at least as many
conjugacy classes as `G ⧸ H`. -/
rw [commProb_def', commProb_def', div_le_iff, mul_assoc, ← Nat.cast_mul, ← Subgroup.index,
H.card_mul_index, div_mul_cancel₀, Nat.cast_le]
· apply Finite.card_le_of_surjective
show Function.Surjective (ConjClasses.map (QuotientGroup.mk' H))
exact ConjClasses.map_surjective Quotient.surjective_Quotient_mk''
· exact Nat.cast_ne_zero.mpr Finite.card_pos.ne'
· exact Nat.cast_pos.mpr Finite.card_pos
|
import Mathlib.Data.Finset.Prod
import Mathlib.Data.Set.Finite
#align_import data.finset.n_ary from "leanprover-community/mathlib"@"eba7871095e834365616b5e43c8c7bb0b37058d0"
open Function Set
variable {α α' β β' γ γ' δ δ' ε ε' ζ ζ' ν : Type*}
namespace Finset
variable [DecidableEq α'] [DecidableEq β'] [DecidableEq γ] [DecidableEq γ'] [DecidableEq δ]
[DecidableEq δ'] [DecidableEq ε] [DecidableEq ε'] {f f' : α → β → γ} {g g' : α → β → γ → δ}
{s s' : Finset α} {t t' : Finset β} {u u' : Finset γ} {a a' : α} {b b' : β} {c : γ}
def image₂ (f : α → β → γ) (s : Finset α) (t : Finset β) : Finset γ :=
(s ×ˢ t).image <| uncurry f
#align finset.image₂ Finset.image₂
@[simp]
theorem mem_image₂ : c ∈ image₂ f s t ↔ ∃ a ∈ s, ∃ b ∈ t, f a b = c := by
simp [image₂, and_assoc]
#align finset.mem_image₂ Finset.mem_image₂
@[simp, norm_cast]
theorem coe_image₂ (f : α → β → γ) (s : Finset α) (t : Finset β) :
(image₂ f s t : Set γ) = Set.image2 f s t :=
Set.ext fun _ => mem_image₂
#align finset.coe_image₂ Finset.coe_image₂
theorem card_image₂_le (f : α → β → γ) (s : Finset α) (t : Finset β) :
(image₂ f s t).card ≤ s.card * t.card :=
card_image_le.trans_eq <| card_product _ _
#align finset.card_image₂_le Finset.card_image₂_le
| Mathlib/Data/Finset/NAry.lean | 58 | 61 | theorem card_image₂_iff :
(image₂ f s t).card = s.card * t.card ↔ (s ×ˢ t : Set (α × β)).InjOn fun x => f x.1 x.2 := by |
rw [← card_product, ← coe_product]
exact card_image_iff
|
import Mathlib.Algebra.BigOperators.Ring
import Mathlib.Algebra.Field.Rat
import Mathlib.Algebra.Order.Field.Basic
import Mathlib.Algebra.Order.Field.Rat
import Mathlib.Combinatorics.Enumerative.DoubleCounting
import Mathlib.Combinatorics.SetFamily.Shadow
#align_import combinatorics.set_family.lym from "leanprover-community/mathlib"@"861a26926586cd46ff80264d121cdb6fa0e35cc1"
open Finset Nat
open FinsetFamily
variable {𝕜 α : Type*} [LinearOrderedField 𝕜]
namespace Finset
section LYM
section Falling
variable [DecidableEq α] (k : ℕ) (𝒜 : Finset (Finset α))
def falling : Finset (Finset α) :=
𝒜.sup <| powersetCard k
#align finset.falling Finset.falling
variable {𝒜 k} {s : Finset α}
theorem mem_falling : s ∈ falling k 𝒜 ↔ (∃ t ∈ 𝒜, s ⊆ t) ∧ s.card = k := by
simp_rw [falling, mem_sup, mem_powersetCard]
aesop
#align finset.mem_falling Finset.mem_falling
variable (𝒜 k)
theorem sized_falling : (falling k 𝒜 : Set (Finset α)).Sized k := fun _ hs => (mem_falling.1 hs).2
#align finset.sized_falling Finset.sized_falling
theorem slice_subset_falling : 𝒜 # k ⊆ falling k 𝒜 := fun s hs =>
mem_falling.2 <| (mem_slice.1 hs).imp_left fun h => ⟨s, h, Subset.refl _⟩
#align finset.slice_subset_falling Finset.slice_subset_falling
theorem falling_zero_subset : falling 0 𝒜 ⊆ {∅} :=
subset_singleton_iff'.2 fun _ ht => card_eq_zero.1 <| sized_falling _ _ ht
#align finset.falling_zero_subset Finset.falling_zero_subset
| Mathlib/Combinatorics/SetFamily/LYM.lean | 149 | 163 | theorem slice_union_shadow_falling_succ : 𝒜 # k ∪ ∂ (falling (k + 1) 𝒜) = falling k 𝒜 := by |
ext s
simp_rw [mem_union, mem_slice, mem_shadow_iff, mem_falling]
constructor
· rintro (h | ⟨s, ⟨⟨t, ht, hst⟩, hs⟩, a, ha, rfl⟩)
· exact ⟨⟨s, h.1, Subset.refl _⟩, h.2⟩
refine ⟨⟨t, ht, (erase_subset _ _).trans hst⟩, ?_⟩
rw [card_erase_of_mem ha, hs]
rfl
· rintro ⟨⟨t, ht, hst⟩, hs⟩
by_cases h : s ∈ 𝒜
· exact Or.inl ⟨h, hs⟩
obtain ⟨a, ha, hst⟩ := ssubset_iff.1 (ssubset_of_subset_of_ne hst (ht.ne_of_not_mem h).symm)
refine Or.inr ⟨insert a s, ⟨⟨t, ht, hst⟩, ?_⟩, a, mem_insert_self _ _, erase_insert ha⟩
rw [card_insert_of_not_mem ha, hs]
|
import Mathlib.Analysis.SpecialFunctions.Trigonometric.Basic
import Mathlib.Analysis.Normed.Group.AddCircle
import Mathlib.Algebra.CharZero.Quotient
import Mathlib.Topology.Instances.Sign
#align_import analysis.special_functions.trigonometric.angle from "leanprover-community/mathlib"@"213b0cff7bc5ab6696ee07cceec80829ce42efec"
open Real
noncomputable section
namespace Real
-- Porting note: can't derive `NormedAddCommGroup, Inhabited`
def Angle : Type :=
AddCircle (2 * π)
#align real.angle Real.Angle
namespace Angle
-- Porting note (#10754): added due to missing instances due to no deriving
instance : NormedAddCommGroup Angle :=
inferInstanceAs (NormedAddCommGroup (AddCircle (2 * π)))
-- Porting note (#10754): added due to missing instances due to no deriving
instance : Inhabited Angle :=
inferInstanceAs (Inhabited (AddCircle (2 * π)))
-- Porting note (#10754): added due to missing instances due to no deriving
-- also, without this, a plain `QuotientAddGroup.mk`
-- causes coerced terms to be of type `ℝ ⧸ AddSubgroup.zmultiples (2 * π)`
@[coe]
protected def coe (r : ℝ) : Angle := QuotientAddGroup.mk r
instance : Coe ℝ Angle := ⟨Angle.coe⟩
instance : CircularOrder Real.Angle :=
QuotientAddGroup.circularOrder (hp' := ⟨by norm_num [pi_pos]⟩)
@[continuity]
theorem continuous_coe : Continuous ((↑) : ℝ → Angle) :=
continuous_quotient_mk'
#align real.angle.continuous_coe Real.Angle.continuous_coe
def coeHom : ℝ →+ Angle :=
QuotientAddGroup.mk' _
#align real.angle.coe_hom Real.Angle.coeHom
@[simp]
theorem coe_coeHom : (coeHom : ℝ → Angle) = ((↑) : ℝ → Angle) :=
rfl
#align real.angle.coe_coe_hom Real.Angle.coe_coeHom
@[elab_as_elim]
protected theorem induction_on {p : Angle → Prop} (θ : Angle) (h : ∀ x : ℝ, p x) : p θ :=
Quotient.inductionOn' θ h
#align real.angle.induction_on Real.Angle.induction_on
@[simp]
theorem coe_zero : ↑(0 : ℝ) = (0 : Angle) :=
rfl
#align real.angle.coe_zero Real.Angle.coe_zero
@[simp]
theorem coe_add (x y : ℝ) : ↑(x + y : ℝ) = (↑x + ↑y : Angle) :=
rfl
#align real.angle.coe_add Real.Angle.coe_add
@[simp]
theorem coe_neg (x : ℝ) : ↑(-x : ℝ) = -(↑x : Angle) :=
rfl
#align real.angle.coe_neg Real.Angle.coe_neg
@[simp]
theorem coe_sub (x y : ℝ) : ↑(x - y : ℝ) = (↑x - ↑y : Angle) :=
rfl
#align real.angle.coe_sub Real.Angle.coe_sub
theorem coe_nsmul (n : ℕ) (x : ℝ) : ↑(n • x : ℝ) = n • (↑x : Angle) :=
rfl
#align real.angle.coe_nsmul Real.Angle.coe_nsmul
theorem coe_zsmul (z : ℤ) (x : ℝ) : ↑(z • x : ℝ) = z • (↑x : Angle) :=
rfl
#align real.angle.coe_zsmul Real.Angle.coe_zsmul
@[simp, norm_cast]
theorem natCast_mul_eq_nsmul (x : ℝ) (n : ℕ) : ↑((n : ℝ) * x) = n • (↑x : Angle) := by
simpa only [nsmul_eq_mul] using coeHom.map_nsmul x n
#align real.angle.coe_nat_mul_eq_nsmul Real.Angle.natCast_mul_eq_nsmul
@[simp, norm_cast]
theorem intCast_mul_eq_zsmul (x : ℝ) (n : ℤ) : ↑((n : ℝ) * x : ℝ) = n • (↑x : Angle) := by
simpa only [zsmul_eq_mul] using coeHom.map_zsmul x n
#align real.angle.coe_int_mul_eq_zsmul Real.Angle.intCast_mul_eq_zsmul
@[deprecated (since := "2024-05-25")] alias coe_nat_mul_eq_nsmul := natCast_mul_eq_nsmul
@[deprecated (since := "2024-05-25")] alias coe_int_mul_eq_zsmul := intCast_mul_eq_zsmul
theorem angle_eq_iff_two_pi_dvd_sub {ψ θ : ℝ} : (θ : Angle) = ψ ↔ ∃ k : ℤ, θ - ψ = 2 * π * k := by
simp only [QuotientAddGroup.eq, AddSubgroup.zmultiples_eq_closure,
AddSubgroup.mem_closure_singleton, zsmul_eq_mul', (sub_eq_neg_add _ _).symm, eq_comm]
-- Porting note: added `rw`, `simp [Angle.coe, QuotientAddGroup.eq]` doesn't fire otherwise
rw [Angle.coe, Angle.coe, QuotientAddGroup.eq]
simp only [AddSubgroup.zmultiples_eq_closure,
AddSubgroup.mem_closure_singleton, zsmul_eq_mul', (sub_eq_neg_add _ _).symm, eq_comm]
#align real.angle.angle_eq_iff_two_pi_dvd_sub Real.Angle.angle_eq_iff_two_pi_dvd_sub
@[simp]
theorem coe_two_pi : ↑(2 * π : ℝ) = (0 : Angle) :=
angle_eq_iff_two_pi_dvd_sub.2 ⟨1, by rw [sub_zero, Int.cast_one, mul_one]⟩
#align real.angle.coe_two_pi Real.Angle.coe_two_pi
@[simp]
theorem neg_coe_pi : -(π : Angle) = π := by
rw [← coe_neg, angle_eq_iff_two_pi_dvd_sub]
use -1
simp [two_mul, sub_eq_add_neg]
#align real.angle.neg_coe_pi Real.Angle.neg_coe_pi
@[simp]
theorem two_nsmul_coe_div_two (θ : ℝ) : (2 : ℕ) • (↑(θ / 2) : Angle) = θ := by
rw [← coe_nsmul, two_nsmul, add_halves]
#align real.angle.two_nsmul_coe_div_two Real.Angle.two_nsmul_coe_div_two
@[simp]
theorem two_zsmul_coe_div_two (θ : ℝ) : (2 : ℤ) • (↑(θ / 2) : Angle) = θ := by
rw [← coe_zsmul, two_zsmul, add_halves]
#align real.angle.two_zsmul_coe_div_two Real.Angle.two_zsmul_coe_div_two
-- Porting note (#10618): @[simp] can prove it
theorem two_nsmul_neg_pi_div_two : (2 : ℕ) • (↑(-π / 2) : Angle) = π := by
rw [two_nsmul_coe_div_two, coe_neg, neg_coe_pi]
#align real.angle.two_nsmul_neg_pi_div_two Real.Angle.two_nsmul_neg_pi_div_two
-- Porting note (#10618): @[simp] can prove it
theorem two_zsmul_neg_pi_div_two : (2 : ℤ) • (↑(-π / 2) : Angle) = π := by
rw [two_zsmul, ← two_nsmul, two_nsmul_neg_pi_div_two]
#align real.angle.two_zsmul_neg_pi_div_two Real.Angle.two_zsmul_neg_pi_div_two
theorem sub_coe_pi_eq_add_coe_pi (θ : Angle) : θ - π = θ + π := by
rw [sub_eq_add_neg, neg_coe_pi]
#align real.angle.sub_coe_pi_eq_add_coe_pi Real.Angle.sub_coe_pi_eq_add_coe_pi
@[simp]
theorem two_nsmul_coe_pi : (2 : ℕ) • (π : Angle) = 0 := by simp [← natCast_mul_eq_nsmul]
#align real.angle.two_nsmul_coe_pi Real.Angle.two_nsmul_coe_pi
@[simp]
theorem two_zsmul_coe_pi : (2 : ℤ) • (π : Angle) = 0 := by simp [← intCast_mul_eq_zsmul]
#align real.angle.two_zsmul_coe_pi Real.Angle.two_zsmul_coe_pi
@[simp]
theorem coe_pi_add_coe_pi : (π : Real.Angle) + π = 0 := by rw [← two_nsmul, two_nsmul_coe_pi]
#align real.angle.coe_pi_add_coe_pi Real.Angle.coe_pi_add_coe_pi
theorem zsmul_eq_iff {ψ θ : Angle} {z : ℤ} (hz : z ≠ 0) :
z • ψ = z • θ ↔ ∃ k : Fin z.natAbs, ψ = θ + (k : ℕ) • (2 * π / z : ℝ) :=
QuotientAddGroup.zmultiples_zsmul_eq_zsmul_iff hz
#align real.angle.zsmul_eq_iff Real.Angle.zsmul_eq_iff
theorem nsmul_eq_iff {ψ θ : Angle} {n : ℕ} (hz : n ≠ 0) :
n • ψ = n • θ ↔ ∃ k : Fin n, ψ = θ + (k : ℕ) • (2 * π / n : ℝ) :=
QuotientAddGroup.zmultiples_nsmul_eq_nsmul_iff hz
#align real.angle.nsmul_eq_iff Real.Angle.nsmul_eq_iff
theorem two_zsmul_eq_iff {ψ θ : Angle} : (2 : ℤ) • ψ = (2 : ℤ) • θ ↔ ψ = θ ∨ ψ = θ + ↑π := by
-- Porting note: no `Int.natAbs_bit0` anymore
have : Int.natAbs 2 = 2 := rfl
rw [zsmul_eq_iff two_ne_zero, this, Fin.exists_fin_two, Fin.val_zero,
Fin.val_one, zero_smul, add_zero, one_smul, Int.cast_two,
mul_div_cancel_left₀ (_ : ℝ) two_ne_zero]
#align real.angle.two_zsmul_eq_iff Real.Angle.two_zsmul_eq_iff
theorem two_nsmul_eq_iff {ψ θ : Angle} : (2 : ℕ) • ψ = (2 : ℕ) • θ ↔ ψ = θ ∨ ψ = θ + ↑π := by
simp_rw [← natCast_zsmul, Nat.cast_ofNat, two_zsmul_eq_iff]
#align real.angle.two_nsmul_eq_iff Real.Angle.two_nsmul_eq_iff
theorem two_nsmul_eq_zero_iff {θ : Angle} : (2 : ℕ) • θ = 0 ↔ θ = 0 ∨ θ = π := by
convert two_nsmul_eq_iff <;> simp
#align real.angle.two_nsmul_eq_zero_iff Real.Angle.two_nsmul_eq_zero_iff
theorem two_nsmul_ne_zero_iff {θ : Angle} : (2 : ℕ) • θ ≠ 0 ↔ θ ≠ 0 ∧ θ ≠ π := by
rw [← not_or, ← two_nsmul_eq_zero_iff]
#align real.angle.two_nsmul_ne_zero_iff Real.Angle.two_nsmul_ne_zero_iff
theorem two_zsmul_eq_zero_iff {θ : Angle} : (2 : ℤ) • θ = 0 ↔ θ = 0 ∨ θ = π := by
simp_rw [two_zsmul, ← two_nsmul, two_nsmul_eq_zero_iff]
#align real.angle.two_zsmul_eq_zero_iff Real.Angle.two_zsmul_eq_zero_iff
theorem two_zsmul_ne_zero_iff {θ : Angle} : (2 : ℤ) • θ ≠ 0 ↔ θ ≠ 0 ∧ θ ≠ π := by
rw [← not_or, ← two_zsmul_eq_zero_iff]
#align real.angle.two_zsmul_ne_zero_iff Real.Angle.two_zsmul_ne_zero_iff
theorem eq_neg_self_iff {θ : Angle} : θ = -θ ↔ θ = 0 ∨ θ = π := by
rw [← add_eq_zero_iff_eq_neg, ← two_nsmul, two_nsmul_eq_zero_iff]
#align real.angle.eq_neg_self_iff Real.Angle.eq_neg_self_iff
theorem ne_neg_self_iff {θ : Angle} : θ ≠ -θ ↔ θ ≠ 0 ∧ θ ≠ π := by
rw [← not_or, ← eq_neg_self_iff.not]
#align real.angle.ne_neg_self_iff Real.Angle.ne_neg_self_iff
theorem neg_eq_self_iff {θ : Angle} : -θ = θ ↔ θ = 0 ∨ θ = π := by rw [eq_comm, eq_neg_self_iff]
#align real.angle.neg_eq_self_iff Real.Angle.neg_eq_self_iff
theorem neg_ne_self_iff {θ : Angle} : -θ ≠ θ ↔ θ ≠ 0 ∧ θ ≠ π := by
rw [← not_or, ← neg_eq_self_iff.not]
#align real.angle.neg_ne_self_iff Real.Angle.neg_ne_self_iff
theorem two_nsmul_eq_pi_iff {θ : Angle} : (2 : ℕ) • θ = π ↔ θ = (π / 2 : ℝ) ∨ θ = (-π / 2 : ℝ) := by
have h : (π : Angle) = ((2 : ℕ) • (π / 2 : ℝ) :) := by rw [two_nsmul, add_halves]
nth_rw 1 [h]
rw [coe_nsmul, two_nsmul_eq_iff]
-- Porting note: `congr` didn't simplify the goal of iff of `Or`s
convert Iff.rfl
rw [add_comm, ← coe_add, ← sub_eq_zero, ← coe_sub, neg_div, ← neg_sub, sub_neg_eq_add, add_assoc,
add_halves, ← two_mul, coe_neg, coe_two_pi, neg_zero]
#align real.angle.two_nsmul_eq_pi_iff Real.Angle.two_nsmul_eq_pi_iff
theorem two_zsmul_eq_pi_iff {θ : Angle} : (2 : ℤ) • θ = π ↔ θ = (π / 2 : ℝ) ∨ θ = (-π / 2 : ℝ) := by
rw [two_zsmul, ← two_nsmul, two_nsmul_eq_pi_iff]
#align real.angle.two_zsmul_eq_pi_iff Real.Angle.two_zsmul_eq_pi_iff
theorem cos_eq_iff_coe_eq_or_eq_neg {θ ψ : ℝ} :
cos θ = cos ψ ↔ (θ : Angle) = ψ ∨ (θ : Angle) = -ψ := by
constructor
· intro Hcos
rw [← sub_eq_zero, cos_sub_cos, mul_eq_zero, mul_eq_zero, neg_eq_zero,
eq_false (two_ne_zero' ℝ), false_or_iff, sin_eq_zero_iff, sin_eq_zero_iff] at Hcos
rcases Hcos with (⟨n, hn⟩ | ⟨n, hn⟩)
· right
rw [eq_div_iff_mul_eq (two_ne_zero' ℝ), ← sub_eq_iff_eq_add] at hn
rw [← hn, coe_sub, eq_neg_iff_add_eq_zero, sub_add_cancel, mul_assoc, intCast_mul_eq_zsmul,
mul_comm, coe_two_pi, zsmul_zero]
· left
rw [eq_div_iff_mul_eq (two_ne_zero' ℝ), eq_sub_iff_add_eq] at hn
rw [← hn, coe_add, mul_assoc, intCast_mul_eq_zsmul, mul_comm, coe_two_pi, zsmul_zero,
zero_add]
· rw [angle_eq_iff_two_pi_dvd_sub, ← coe_neg, angle_eq_iff_two_pi_dvd_sub]
rintro (⟨k, H⟩ | ⟨k, H⟩)
· rw [← sub_eq_zero, cos_sub_cos, H, mul_assoc 2 π k, mul_div_cancel_left₀ _ (two_ne_zero' ℝ),
mul_comm π _, sin_int_mul_pi, mul_zero]
rw [← sub_eq_zero, cos_sub_cos, ← sub_neg_eq_add, H, mul_assoc 2 π k,
mul_div_cancel_left₀ _ (two_ne_zero' ℝ), mul_comm π _, sin_int_mul_pi, mul_zero,
zero_mul]
#align real.angle.cos_eq_iff_coe_eq_or_eq_neg Real.Angle.cos_eq_iff_coe_eq_or_eq_neg
theorem sin_eq_iff_coe_eq_or_add_eq_pi {θ ψ : ℝ} :
sin θ = sin ψ ↔ (θ : Angle) = ψ ∨ (θ : Angle) + ψ = π := by
constructor
· intro Hsin
rw [← cos_pi_div_two_sub, ← cos_pi_div_two_sub] at Hsin
cases' cos_eq_iff_coe_eq_or_eq_neg.mp Hsin with h h
· left
rw [coe_sub, coe_sub] at h
exact sub_right_inj.1 h
right
rw [coe_sub, coe_sub, eq_neg_iff_add_eq_zero, add_sub, sub_add_eq_add_sub, ← coe_add,
add_halves, sub_sub, sub_eq_zero] at h
exact h.symm
· rw [angle_eq_iff_two_pi_dvd_sub, ← eq_sub_iff_add_eq, ← coe_sub, angle_eq_iff_two_pi_dvd_sub]
rintro (⟨k, H⟩ | ⟨k, H⟩)
· rw [← sub_eq_zero, sin_sub_sin, H, mul_assoc 2 π k, mul_div_cancel_left₀ _ (two_ne_zero' ℝ),
mul_comm π _, sin_int_mul_pi, mul_zero, zero_mul]
have H' : θ + ψ = 2 * k * π + π := by
rwa [← sub_add, sub_add_eq_add_sub, sub_eq_iff_eq_add, mul_assoc, mul_comm π _, ←
mul_assoc] at H
rw [← sub_eq_zero, sin_sub_sin, H', add_div, mul_assoc 2 _ π,
mul_div_cancel_left₀ _ (two_ne_zero' ℝ), cos_add_pi_div_two, sin_int_mul_pi, neg_zero,
mul_zero]
#align real.angle.sin_eq_iff_coe_eq_or_add_eq_pi Real.Angle.sin_eq_iff_coe_eq_or_add_eq_pi
theorem cos_sin_inj {θ ψ : ℝ} (Hcos : cos θ = cos ψ) (Hsin : sin θ = sin ψ) : (θ : Angle) = ψ := by
cases' cos_eq_iff_coe_eq_or_eq_neg.mp Hcos with hc hc; · exact hc
cases' sin_eq_iff_coe_eq_or_add_eq_pi.mp Hsin with hs hs; · exact hs
rw [eq_neg_iff_add_eq_zero, hs] at hc
obtain ⟨n, hn⟩ : ∃ n, n • _ = _ := QuotientAddGroup.leftRel_apply.mp (Quotient.exact' hc)
rw [← neg_one_mul, add_zero, ← sub_eq_zero, zsmul_eq_mul, ← mul_assoc, ← sub_mul, mul_eq_zero,
eq_false (ne_of_gt pi_pos), or_false_iff, sub_neg_eq_add, ← Int.cast_zero, ← Int.cast_one,
← Int.cast_ofNat, ← Int.cast_mul, ← Int.cast_add, Int.cast_inj] at hn
have : (n * 2 + 1) % (2 : ℤ) = 0 % (2 : ℤ) := congr_arg (· % (2 : ℤ)) hn
rw [add_comm, Int.add_mul_emod_self] at this
exact absurd this one_ne_zero
#align real.angle.cos_sin_inj Real.Angle.cos_sin_inj
def sin (θ : Angle) : ℝ :=
sin_periodic.lift θ
#align real.angle.sin Real.Angle.sin
@[simp]
theorem sin_coe (x : ℝ) : sin (x : Angle) = Real.sin x :=
rfl
#align real.angle.sin_coe Real.Angle.sin_coe
@[continuity]
theorem continuous_sin : Continuous sin :=
Real.continuous_sin.quotient_liftOn' _
#align real.angle.continuous_sin Real.Angle.continuous_sin
def cos (θ : Angle) : ℝ :=
cos_periodic.lift θ
#align real.angle.cos Real.Angle.cos
@[simp]
theorem cos_coe (x : ℝ) : cos (x : Angle) = Real.cos x :=
rfl
#align real.angle.cos_coe Real.Angle.cos_coe
@[continuity]
theorem continuous_cos : Continuous cos :=
Real.continuous_cos.quotient_liftOn' _
#align real.angle.continuous_cos Real.Angle.continuous_cos
theorem cos_eq_real_cos_iff_eq_or_eq_neg {θ : Angle} {ψ : ℝ} :
cos θ = Real.cos ψ ↔ θ = ψ ∨ θ = -ψ := by
induction θ using Real.Angle.induction_on
exact cos_eq_iff_coe_eq_or_eq_neg
#align real.angle.cos_eq_real_cos_iff_eq_or_eq_neg Real.Angle.cos_eq_real_cos_iff_eq_or_eq_neg
theorem cos_eq_iff_eq_or_eq_neg {θ ψ : Angle} : cos θ = cos ψ ↔ θ = ψ ∨ θ = -ψ := by
induction ψ using Real.Angle.induction_on
exact cos_eq_real_cos_iff_eq_or_eq_neg
#align real.angle.cos_eq_iff_eq_or_eq_neg Real.Angle.cos_eq_iff_eq_or_eq_neg
theorem sin_eq_real_sin_iff_eq_or_add_eq_pi {θ : Angle} {ψ : ℝ} :
sin θ = Real.sin ψ ↔ θ = ψ ∨ θ + ψ = π := by
induction θ using Real.Angle.induction_on
exact sin_eq_iff_coe_eq_or_add_eq_pi
#align real.angle.sin_eq_real_sin_iff_eq_or_add_eq_pi Real.Angle.sin_eq_real_sin_iff_eq_or_add_eq_pi
theorem sin_eq_iff_eq_or_add_eq_pi {θ ψ : Angle} : sin θ = sin ψ ↔ θ = ψ ∨ θ + ψ = π := by
induction ψ using Real.Angle.induction_on
exact sin_eq_real_sin_iff_eq_or_add_eq_pi
#align real.angle.sin_eq_iff_eq_or_add_eq_pi Real.Angle.sin_eq_iff_eq_or_add_eq_pi
@[simp]
theorem sin_zero : sin (0 : Angle) = 0 := by rw [← coe_zero, sin_coe, Real.sin_zero]
#align real.angle.sin_zero Real.Angle.sin_zero
-- Porting note (#10618): @[simp] can prove it
theorem sin_coe_pi : sin (π : Angle) = 0 := by rw [sin_coe, Real.sin_pi]
#align real.angle.sin_coe_pi Real.Angle.sin_coe_pi
theorem sin_eq_zero_iff {θ : Angle} : sin θ = 0 ↔ θ = 0 ∨ θ = π := by
nth_rw 1 [← sin_zero]
rw [sin_eq_iff_eq_or_add_eq_pi]
simp
#align real.angle.sin_eq_zero_iff Real.Angle.sin_eq_zero_iff
theorem sin_ne_zero_iff {θ : Angle} : sin θ ≠ 0 ↔ θ ≠ 0 ∧ θ ≠ π := by
rw [← not_or, ← sin_eq_zero_iff]
#align real.angle.sin_ne_zero_iff Real.Angle.sin_ne_zero_iff
@[simp]
theorem sin_neg (θ : Angle) : sin (-θ) = -sin θ := by
induction θ using Real.Angle.induction_on
exact Real.sin_neg _
#align real.angle.sin_neg Real.Angle.sin_neg
theorem sin_antiperiodic : Function.Antiperiodic sin (π : Angle) := by
intro θ
induction θ using Real.Angle.induction_on
exact Real.sin_antiperiodic _
#align real.angle.sin_antiperiodic Real.Angle.sin_antiperiodic
@[simp]
theorem sin_add_pi (θ : Angle) : sin (θ + π) = -sin θ :=
sin_antiperiodic θ
#align real.angle.sin_add_pi Real.Angle.sin_add_pi
@[simp]
theorem sin_sub_pi (θ : Angle) : sin (θ - π) = -sin θ :=
sin_antiperiodic.sub_eq θ
#align real.angle.sin_sub_pi Real.Angle.sin_sub_pi
@[simp]
theorem cos_zero : cos (0 : Angle) = 1 := by rw [← coe_zero, cos_coe, Real.cos_zero]
#align real.angle.cos_zero Real.Angle.cos_zero
-- Porting note (#10618): @[simp] can prove it
theorem cos_coe_pi : cos (π : Angle) = -1 := by rw [cos_coe, Real.cos_pi]
#align real.angle.cos_coe_pi Real.Angle.cos_coe_pi
@[simp]
theorem cos_neg (θ : Angle) : cos (-θ) = cos θ := by
induction θ using Real.Angle.induction_on
exact Real.cos_neg _
#align real.angle.cos_neg Real.Angle.cos_neg
theorem cos_antiperiodic : Function.Antiperiodic cos (π : Angle) := by
intro θ
induction θ using Real.Angle.induction_on
exact Real.cos_antiperiodic _
#align real.angle.cos_antiperiodic Real.Angle.cos_antiperiodic
@[simp]
theorem cos_add_pi (θ : Angle) : cos (θ + π) = -cos θ :=
cos_antiperiodic θ
#align real.angle.cos_add_pi Real.Angle.cos_add_pi
@[simp]
theorem cos_sub_pi (θ : Angle) : cos (θ - π) = -cos θ :=
cos_antiperiodic.sub_eq θ
#align real.angle.cos_sub_pi Real.Angle.cos_sub_pi
theorem cos_eq_zero_iff {θ : Angle} : cos θ = 0 ↔ θ = (π / 2 : ℝ) ∨ θ = (-π / 2 : ℝ) := by
rw [← cos_pi_div_two, ← cos_coe, cos_eq_iff_eq_or_eq_neg, ← coe_neg, ← neg_div]
#align real.angle.cos_eq_zero_iff Real.Angle.cos_eq_zero_iff
theorem sin_add (θ₁ θ₂ : Real.Angle) : sin (θ₁ + θ₂) = sin θ₁ * cos θ₂ + cos θ₁ * sin θ₂ := by
induction θ₁ using Real.Angle.induction_on
induction θ₂ using Real.Angle.induction_on
exact Real.sin_add _ _
#align real.angle.sin_add Real.Angle.sin_add
theorem cos_add (θ₁ θ₂ : Real.Angle) : cos (θ₁ + θ₂) = cos θ₁ * cos θ₂ - sin θ₁ * sin θ₂ := by
induction θ₂ using Real.Angle.induction_on
induction θ₁ using Real.Angle.induction_on
exact Real.cos_add _ _
#align real.angle.cos_add Real.Angle.cos_add
@[simp]
theorem cos_sq_add_sin_sq (θ : Real.Angle) : cos θ ^ 2 + sin θ ^ 2 = 1 := by
induction θ using Real.Angle.induction_on
exact Real.cos_sq_add_sin_sq _
#align real.angle.cos_sq_add_sin_sq Real.Angle.cos_sq_add_sin_sq
theorem sin_add_pi_div_two (θ : Angle) : sin (θ + ↑(π / 2)) = cos θ := by
induction θ using Real.Angle.induction_on
exact Real.sin_add_pi_div_two _
#align real.angle.sin_add_pi_div_two Real.Angle.sin_add_pi_div_two
theorem sin_sub_pi_div_two (θ : Angle) : sin (θ - ↑(π / 2)) = -cos θ := by
induction θ using Real.Angle.induction_on
exact Real.sin_sub_pi_div_two _
#align real.angle.sin_sub_pi_div_two Real.Angle.sin_sub_pi_div_two
theorem sin_pi_div_two_sub (θ : Angle) : sin (↑(π / 2) - θ) = cos θ := by
induction θ using Real.Angle.induction_on
exact Real.sin_pi_div_two_sub _
#align real.angle.sin_pi_div_two_sub Real.Angle.sin_pi_div_two_sub
theorem cos_add_pi_div_two (θ : Angle) : cos (θ + ↑(π / 2)) = -sin θ := by
induction θ using Real.Angle.induction_on
exact Real.cos_add_pi_div_two _
#align real.angle.cos_add_pi_div_two Real.Angle.cos_add_pi_div_two
theorem cos_sub_pi_div_two (θ : Angle) : cos (θ - ↑(π / 2)) = sin θ := by
induction θ using Real.Angle.induction_on
exact Real.cos_sub_pi_div_two _
#align real.angle.cos_sub_pi_div_two Real.Angle.cos_sub_pi_div_two
theorem cos_pi_div_two_sub (θ : Angle) : cos (↑(π / 2) - θ) = sin θ := by
induction θ using Real.Angle.induction_on
exact Real.cos_pi_div_two_sub _
#align real.angle.cos_pi_div_two_sub Real.Angle.cos_pi_div_two_sub
theorem abs_sin_eq_of_two_nsmul_eq {θ ψ : Angle} (h : (2 : ℕ) • θ = (2 : ℕ) • ψ) :
|sin θ| = |sin ψ| := by
rw [two_nsmul_eq_iff] at h
rcases h with (rfl | rfl)
· rfl
· rw [sin_add_pi, abs_neg]
#align real.angle.abs_sin_eq_of_two_nsmul_eq Real.Angle.abs_sin_eq_of_two_nsmul_eq
theorem abs_sin_eq_of_two_zsmul_eq {θ ψ : Angle} (h : (2 : ℤ) • θ = (2 : ℤ) • ψ) :
|sin θ| = |sin ψ| := by
simp_rw [two_zsmul, ← two_nsmul] at h
exact abs_sin_eq_of_two_nsmul_eq h
#align real.angle.abs_sin_eq_of_two_zsmul_eq Real.Angle.abs_sin_eq_of_two_zsmul_eq
theorem abs_cos_eq_of_two_nsmul_eq {θ ψ : Angle} (h : (2 : ℕ) • θ = (2 : ℕ) • ψ) :
|cos θ| = |cos ψ| := by
rw [two_nsmul_eq_iff] at h
rcases h with (rfl | rfl)
· rfl
· rw [cos_add_pi, abs_neg]
#align real.angle.abs_cos_eq_of_two_nsmul_eq Real.Angle.abs_cos_eq_of_two_nsmul_eq
theorem abs_cos_eq_of_two_zsmul_eq {θ ψ : Angle} (h : (2 : ℤ) • θ = (2 : ℤ) • ψ) :
|cos θ| = |cos ψ| := by
simp_rw [two_zsmul, ← two_nsmul] at h
exact abs_cos_eq_of_two_nsmul_eq h
#align real.angle.abs_cos_eq_of_two_zsmul_eq Real.Angle.abs_cos_eq_of_two_zsmul_eq
@[simp]
theorem coe_toIcoMod (θ ψ : ℝ) : ↑(toIcoMod two_pi_pos ψ θ) = (θ : Angle) := by
rw [angle_eq_iff_two_pi_dvd_sub]
refine ⟨-toIcoDiv two_pi_pos ψ θ, ?_⟩
rw [toIcoMod_sub_self, zsmul_eq_mul, mul_comm]
#align real.angle.coe_to_Ico_mod Real.Angle.coe_toIcoMod
@[simp]
theorem coe_toIocMod (θ ψ : ℝ) : ↑(toIocMod two_pi_pos ψ θ) = (θ : Angle) := by
rw [angle_eq_iff_two_pi_dvd_sub]
refine ⟨-toIocDiv two_pi_pos ψ θ, ?_⟩
rw [toIocMod_sub_self, zsmul_eq_mul, mul_comm]
#align real.angle.coe_to_Ioc_mod Real.Angle.coe_toIocMod
def toReal (θ : Angle) : ℝ :=
(toIocMod_periodic two_pi_pos (-π)).lift θ
#align real.angle.to_real Real.Angle.toReal
theorem toReal_coe (θ : ℝ) : (θ : Angle).toReal = toIocMod two_pi_pos (-π) θ :=
rfl
#align real.angle.to_real_coe Real.Angle.toReal_coe
theorem toReal_coe_eq_self_iff {θ : ℝ} : (θ : Angle).toReal = θ ↔ -π < θ ∧ θ ≤ π := by
rw [toReal_coe, toIocMod_eq_self two_pi_pos]
ring_nf
rfl
#align real.angle.to_real_coe_eq_self_iff Real.Angle.toReal_coe_eq_self_iff
theorem toReal_coe_eq_self_iff_mem_Ioc {θ : ℝ} : (θ : Angle).toReal = θ ↔ θ ∈ Set.Ioc (-π) π := by
rw [toReal_coe_eq_self_iff, ← Set.mem_Ioc]
#align real.angle.to_real_coe_eq_self_iff_mem_Ioc Real.Angle.toReal_coe_eq_self_iff_mem_Ioc
theorem toReal_injective : Function.Injective toReal := by
intro θ ψ h
induction θ using Real.Angle.induction_on
induction ψ using Real.Angle.induction_on
simpa [toReal_coe, toIocMod_eq_toIocMod, zsmul_eq_mul, mul_comm _ (2 * π), ←
angle_eq_iff_two_pi_dvd_sub, eq_comm] using h
#align real.angle.to_real_injective Real.Angle.toReal_injective
@[simp]
theorem toReal_inj {θ ψ : Angle} : θ.toReal = ψ.toReal ↔ θ = ψ :=
toReal_injective.eq_iff
#align real.angle.to_real_inj Real.Angle.toReal_inj
@[simp]
theorem coe_toReal (θ : Angle) : (θ.toReal : Angle) = θ := by
induction θ using Real.Angle.induction_on
exact coe_toIocMod _ _
#align real.angle.coe_to_real Real.Angle.coe_toReal
theorem neg_pi_lt_toReal (θ : Angle) : -π < θ.toReal := by
induction θ using Real.Angle.induction_on
exact left_lt_toIocMod _ _ _
#align real.angle.neg_pi_lt_to_real Real.Angle.neg_pi_lt_toReal
theorem toReal_le_pi (θ : Angle) : θ.toReal ≤ π := by
induction θ using Real.Angle.induction_on
convert toIocMod_le_right two_pi_pos _ _
ring
#align real.angle.to_real_le_pi Real.Angle.toReal_le_pi
theorem abs_toReal_le_pi (θ : Angle) : |θ.toReal| ≤ π :=
abs_le.2 ⟨(neg_pi_lt_toReal _).le, toReal_le_pi _⟩
#align real.angle.abs_to_real_le_pi Real.Angle.abs_toReal_le_pi
theorem toReal_mem_Ioc (θ : Angle) : θ.toReal ∈ Set.Ioc (-π) π :=
⟨neg_pi_lt_toReal _, toReal_le_pi _⟩
#align real.angle.to_real_mem_Ioc Real.Angle.toReal_mem_Ioc
@[simp]
theorem toIocMod_toReal (θ : Angle) : toIocMod two_pi_pos (-π) θ.toReal = θ.toReal := by
induction θ using Real.Angle.induction_on
rw [toReal_coe]
exact toIocMod_toIocMod _ _ _ _
#align real.angle.to_Ioc_mod_to_real Real.Angle.toIocMod_toReal
@[simp]
theorem toReal_zero : (0 : Angle).toReal = 0 := by
rw [← coe_zero, toReal_coe_eq_self_iff]
exact ⟨Left.neg_neg_iff.2 Real.pi_pos, Real.pi_pos.le⟩
#align real.angle.to_real_zero Real.Angle.toReal_zero
@[simp]
theorem toReal_eq_zero_iff {θ : Angle} : θ.toReal = 0 ↔ θ = 0 := by
nth_rw 1 [← toReal_zero]
exact toReal_inj
#align real.angle.to_real_eq_zero_iff Real.Angle.toReal_eq_zero_iff
@[simp]
theorem toReal_pi : (π : Angle).toReal = π := by
rw [toReal_coe_eq_self_iff]
exact ⟨Left.neg_lt_self Real.pi_pos, le_refl _⟩
#align real.angle.to_real_pi Real.Angle.toReal_pi
@[simp]
theorem toReal_eq_pi_iff {θ : Angle} : θ.toReal = π ↔ θ = π := by rw [← toReal_inj, toReal_pi]
#align real.angle.to_real_eq_pi_iff Real.Angle.toReal_eq_pi_iff
theorem pi_ne_zero : (π : Angle) ≠ 0 := by
rw [← toReal_injective.ne_iff, toReal_pi, toReal_zero]
exact Real.pi_ne_zero
#align real.angle.pi_ne_zero Real.Angle.pi_ne_zero
@[simp]
theorem toReal_pi_div_two : ((π / 2 : ℝ) : Angle).toReal = π / 2 :=
toReal_coe_eq_self_iff.2 <| by constructor <;> linarith [pi_pos]
#align real.angle.to_real_pi_div_two Real.Angle.toReal_pi_div_two
@[simp]
theorem toReal_eq_pi_div_two_iff {θ : Angle} : θ.toReal = π / 2 ↔ θ = (π / 2 : ℝ) := by
rw [← toReal_inj, toReal_pi_div_two]
#align real.angle.to_real_eq_pi_div_two_iff Real.Angle.toReal_eq_pi_div_two_iff
@[simp]
theorem toReal_neg_pi_div_two : ((-π / 2 : ℝ) : Angle).toReal = -π / 2 :=
toReal_coe_eq_self_iff.2 <| by constructor <;> linarith [pi_pos]
#align real.angle.to_real_neg_pi_div_two Real.Angle.toReal_neg_pi_div_two
@[simp]
theorem toReal_eq_neg_pi_div_two_iff {θ : Angle} : θ.toReal = -π / 2 ↔ θ = (-π / 2 : ℝ) := by
rw [← toReal_inj, toReal_neg_pi_div_two]
#align real.angle.to_real_eq_neg_pi_div_two_iff Real.Angle.toReal_eq_neg_pi_div_two_iff
theorem pi_div_two_ne_zero : ((π / 2 : ℝ) : Angle) ≠ 0 := by
rw [← toReal_injective.ne_iff, toReal_pi_div_two, toReal_zero]
exact div_ne_zero Real.pi_ne_zero two_ne_zero
#align real.angle.pi_div_two_ne_zero Real.Angle.pi_div_two_ne_zero
theorem neg_pi_div_two_ne_zero : ((-π / 2 : ℝ) : Angle) ≠ 0 := by
rw [← toReal_injective.ne_iff, toReal_neg_pi_div_two, toReal_zero]
exact div_ne_zero (neg_ne_zero.2 Real.pi_ne_zero) two_ne_zero
#align real.angle.neg_pi_div_two_ne_zero Real.Angle.neg_pi_div_two_ne_zero
theorem abs_toReal_coe_eq_self_iff {θ : ℝ} : |(θ : Angle).toReal| = θ ↔ 0 ≤ θ ∧ θ ≤ π :=
⟨fun h => h ▸ ⟨abs_nonneg _, abs_toReal_le_pi _⟩, fun h =>
(toReal_coe_eq_self_iff.2 ⟨(Left.neg_neg_iff.2 Real.pi_pos).trans_le h.1, h.2⟩).symm ▸
abs_eq_self.2 h.1⟩
#align real.angle.abs_to_real_coe_eq_self_iff Real.Angle.abs_toReal_coe_eq_self_iff
theorem abs_toReal_neg_coe_eq_self_iff {θ : ℝ} : |(-θ : Angle).toReal| = θ ↔ 0 ≤ θ ∧ θ ≤ π := by
refine ⟨fun h => h ▸ ⟨abs_nonneg _, abs_toReal_le_pi _⟩, fun h => ?_⟩
by_cases hnegpi : θ = π; · simp [hnegpi, Real.pi_pos.le]
rw [← coe_neg,
toReal_coe_eq_self_iff.2
⟨neg_lt_neg (lt_of_le_of_ne h.2 hnegpi), (neg_nonpos.2 h.1).trans Real.pi_pos.le⟩,
abs_neg, abs_eq_self.2 h.1]
#align real.angle.abs_to_real_neg_coe_eq_self_iff Real.Angle.abs_toReal_neg_coe_eq_self_iff
theorem abs_toReal_eq_pi_div_two_iff {θ : Angle} :
|θ.toReal| = π / 2 ↔ θ = (π / 2 : ℝ) ∨ θ = (-π / 2 : ℝ) := by
rw [abs_eq (div_nonneg Real.pi_pos.le two_pos.le), ← neg_div, toReal_eq_pi_div_two_iff,
toReal_eq_neg_pi_div_two_iff]
#align real.angle.abs_to_real_eq_pi_div_two_iff Real.Angle.abs_toReal_eq_pi_div_two_iff
theorem nsmul_toReal_eq_mul {n : ℕ} (h : n ≠ 0) {θ : Angle} :
(n • θ).toReal = n * θ.toReal ↔ θ.toReal ∈ Set.Ioc (-π / n) (π / n) := by
nth_rw 1 [← coe_toReal θ]
have h' : 0 < (n : ℝ) := mod_cast Nat.pos_of_ne_zero h
rw [← coe_nsmul, nsmul_eq_mul, toReal_coe_eq_self_iff, Set.mem_Ioc, div_lt_iff' h',
le_div_iff' h']
#align real.angle.nsmul_to_real_eq_mul Real.Angle.nsmul_toReal_eq_mul
theorem two_nsmul_toReal_eq_two_mul {θ : Angle} :
((2 : ℕ) • θ).toReal = 2 * θ.toReal ↔ θ.toReal ∈ Set.Ioc (-π / 2) (π / 2) :=
mod_cast nsmul_toReal_eq_mul two_ne_zero
#align real.angle.two_nsmul_to_real_eq_two_mul Real.Angle.two_nsmul_toReal_eq_two_mul
theorem two_zsmul_toReal_eq_two_mul {θ : Angle} :
((2 : ℤ) • θ).toReal = 2 * θ.toReal ↔ θ.toReal ∈ Set.Ioc (-π / 2) (π / 2) := by
rw [two_zsmul, ← two_nsmul, two_nsmul_toReal_eq_two_mul]
#align real.angle.two_zsmul_to_real_eq_two_mul Real.Angle.two_zsmul_toReal_eq_two_mul
theorem toReal_coe_eq_self_sub_two_mul_int_mul_pi_iff {θ : ℝ} {k : ℤ} :
(θ : Angle).toReal = θ - 2 * k * π ↔ θ ∈ Set.Ioc ((2 * k - 1 : ℝ) * π) ((2 * k + 1) * π) := by
rw [← sub_zero (θ : Angle), ← zsmul_zero k, ← coe_two_pi, ← coe_zsmul, ← coe_sub, zsmul_eq_mul, ←
mul_assoc, mul_comm (k : ℝ), toReal_coe_eq_self_iff, Set.mem_Ioc]
exact ⟨fun h => ⟨by linarith, by linarith⟩, fun h => ⟨by linarith, by linarith⟩⟩
#align real.angle.to_real_coe_eq_self_sub_two_mul_int_mul_pi_iff Real.Angle.toReal_coe_eq_self_sub_two_mul_int_mul_pi_iff
theorem toReal_coe_eq_self_sub_two_pi_iff {θ : ℝ} :
(θ : Angle).toReal = θ - 2 * π ↔ θ ∈ Set.Ioc π (3 * π) := by
convert @toReal_coe_eq_self_sub_two_mul_int_mul_pi_iff θ 1 <;> norm_num
#align real.angle.to_real_coe_eq_self_sub_two_pi_iff Real.Angle.toReal_coe_eq_self_sub_two_pi_iff
theorem toReal_coe_eq_self_add_two_pi_iff {θ : ℝ} :
(θ : Angle).toReal = θ + 2 * π ↔ θ ∈ Set.Ioc (-3 * π) (-π) := by
convert @toReal_coe_eq_self_sub_two_mul_int_mul_pi_iff θ (-1) using 2 <;>
set_option tactic.skipAssignedInstances false in norm_num
#align real.angle.to_real_coe_eq_self_add_two_pi_iff Real.Angle.toReal_coe_eq_self_add_two_pi_iff
theorem two_nsmul_toReal_eq_two_mul_sub_two_pi {θ : Angle} :
((2 : ℕ) • θ).toReal = 2 * θ.toReal - 2 * π ↔ π / 2 < θ.toReal := by
nth_rw 1 [← coe_toReal θ]
rw [← coe_nsmul, two_nsmul, ← two_mul, toReal_coe_eq_self_sub_two_pi_iff, Set.mem_Ioc]
exact
⟨fun h => by linarith, fun h =>
⟨(div_lt_iff' (zero_lt_two' ℝ)).1 h, by linarith [pi_pos, toReal_le_pi θ]⟩⟩
#align real.angle.two_nsmul_to_real_eq_two_mul_sub_two_pi Real.Angle.two_nsmul_toReal_eq_two_mul_sub_two_pi
theorem two_zsmul_toReal_eq_two_mul_sub_two_pi {θ : Angle} :
((2 : ℤ) • θ).toReal = 2 * θ.toReal - 2 * π ↔ π / 2 < θ.toReal := by
rw [two_zsmul, ← two_nsmul, two_nsmul_toReal_eq_two_mul_sub_two_pi]
#align real.angle.two_zsmul_to_real_eq_two_mul_sub_two_pi Real.Angle.two_zsmul_toReal_eq_two_mul_sub_two_pi
theorem two_nsmul_toReal_eq_two_mul_add_two_pi {θ : Angle} :
((2 : ℕ) • θ).toReal = 2 * θ.toReal + 2 * π ↔ θ.toReal ≤ -π / 2 := by
nth_rw 1 [← coe_toReal θ]
rw [← coe_nsmul, two_nsmul, ← two_mul, toReal_coe_eq_self_add_two_pi_iff, Set.mem_Ioc]
refine
⟨fun h => by linarith, fun h =>
⟨by linarith [pi_pos, neg_pi_lt_toReal θ], (le_div_iff' (zero_lt_two' ℝ)).1 h⟩⟩
#align real.angle.two_nsmul_to_real_eq_two_mul_add_two_pi Real.Angle.two_nsmul_toReal_eq_two_mul_add_two_pi
theorem two_zsmul_toReal_eq_two_mul_add_two_pi {θ : Angle} :
((2 : ℤ) • θ).toReal = 2 * θ.toReal + 2 * π ↔ θ.toReal ≤ -π / 2 := by
rw [two_zsmul, ← two_nsmul, two_nsmul_toReal_eq_two_mul_add_two_pi]
#align real.angle.two_zsmul_to_real_eq_two_mul_add_two_pi Real.Angle.two_zsmul_toReal_eq_two_mul_add_two_pi
@[simp]
theorem sin_toReal (θ : Angle) : Real.sin θ.toReal = sin θ := by
conv_rhs => rw [← coe_toReal θ, sin_coe]
#align real.angle.sin_to_real Real.Angle.sin_toReal
@[simp]
theorem cos_toReal (θ : Angle) : Real.cos θ.toReal = cos θ := by
conv_rhs => rw [← coe_toReal θ, cos_coe]
#align real.angle.cos_to_real Real.Angle.cos_toReal
theorem cos_nonneg_iff_abs_toReal_le_pi_div_two {θ : Angle} : 0 ≤ cos θ ↔ |θ.toReal| ≤ π / 2 := by
nth_rw 1 [← coe_toReal θ]
rw [abs_le, cos_coe]
refine ⟨fun h => ?_, cos_nonneg_of_mem_Icc⟩
by_contra hn
rw [not_and_or, not_le, not_le] at hn
refine (not_lt.2 h) ?_
rcases hn with (hn | hn)
· rw [← Real.cos_neg]
refine cos_neg_of_pi_div_two_lt_of_lt (by linarith) ?_
linarith [neg_pi_lt_toReal θ]
· refine cos_neg_of_pi_div_two_lt_of_lt hn ?_
linarith [toReal_le_pi θ]
#align real.angle.cos_nonneg_iff_abs_to_real_le_pi_div_two Real.Angle.cos_nonneg_iff_abs_toReal_le_pi_div_two
theorem cos_pos_iff_abs_toReal_lt_pi_div_two {θ : Angle} : 0 < cos θ ↔ |θ.toReal| < π / 2 := by
rw [lt_iff_le_and_ne, lt_iff_le_and_ne, cos_nonneg_iff_abs_toReal_le_pi_div_two, ←
and_congr_right]
rintro -
rw [Ne, Ne, not_iff_not, @eq_comm ℝ 0, abs_toReal_eq_pi_div_two_iff, cos_eq_zero_iff]
#align real.angle.cos_pos_iff_abs_to_real_lt_pi_div_two Real.Angle.cos_pos_iff_abs_toReal_lt_pi_div_two
theorem cos_neg_iff_pi_div_two_lt_abs_toReal {θ : Angle} : cos θ < 0 ↔ π / 2 < |θ.toReal| := by
rw [← not_le, ← not_le, not_iff_not, cos_nonneg_iff_abs_toReal_le_pi_div_two]
#align real.angle.cos_neg_iff_pi_div_two_lt_abs_to_real Real.Angle.cos_neg_iff_pi_div_two_lt_abs_toReal
theorem abs_cos_eq_abs_sin_of_two_nsmul_add_two_nsmul_eq_pi {θ ψ : Angle}
(h : (2 : ℕ) • θ + (2 : ℕ) • ψ = π) : |cos θ| = |sin ψ| := by
rw [← eq_sub_iff_add_eq, ← two_nsmul_coe_div_two, ← nsmul_sub, two_nsmul_eq_iff] at h
rcases h with (rfl | rfl) <;> simp [cos_pi_div_two_sub]
#align real.angle.abs_cos_eq_abs_sin_of_two_nsmul_add_two_nsmul_eq_pi Real.Angle.abs_cos_eq_abs_sin_of_two_nsmul_add_two_nsmul_eq_pi
theorem abs_cos_eq_abs_sin_of_two_zsmul_add_two_zsmul_eq_pi {θ ψ : Angle}
(h : (2 : ℤ) • θ + (2 : ℤ) • ψ = π) : |cos θ| = |sin ψ| := by
simp_rw [two_zsmul, ← two_nsmul] at h
exact abs_cos_eq_abs_sin_of_two_nsmul_add_two_nsmul_eq_pi h
#align real.angle.abs_cos_eq_abs_sin_of_two_zsmul_add_two_zsmul_eq_pi Real.Angle.abs_cos_eq_abs_sin_of_two_zsmul_add_two_zsmul_eq_pi
def tan (θ : Angle) : ℝ :=
sin θ / cos θ
#align real.angle.tan Real.Angle.tan
theorem tan_eq_sin_div_cos (θ : Angle) : tan θ = sin θ / cos θ :=
rfl
#align real.angle.tan_eq_sin_div_cos Real.Angle.tan_eq_sin_div_cos
@[simp]
theorem tan_coe (x : ℝ) : tan (x : Angle) = Real.tan x := by
rw [tan, sin_coe, cos_coe, Real.tan_eq_sin_div_cos]
#align real.angle.tan_coe Real.Angle.tan_coe
@[simp]
theorem tan_zero : tan (0 : Angle) = 0 := by rw [← coe_zero, tan_coe, Real.tan_zero]
#align real.angle.tan_zero Real.Angle.tan_zero
-- Porting note (#10618): @[simp] can now prove it
theorem tan_coe_pi : tan (π : Angle) = 0 := by rw [tan_coe, Real.tan_pi]
#align real.angle.tan_coe_pi Real.Angle.tan_coe_pi
theorem tan_periodic : Function.Periodic tan (π : Angle) := by
intro θ
induction θ using Real.Angle.induction_on
rw [← coe_add, tan_coe, tan_coe]
exact Real.tan_periodic _
#align real.angle.tan_periodic Real.Angle.tan_periodic
@[simp]
theorem tan_add_pi (θ : Angle) : tan (θ + π) = tan θ :=
tan_periodic θ
#align real.angle.tan_add_pi Real.Angle.tan_add_pi
@[simp]
theorem tan_sub_pi (θ : Angle) : tan (θ - π) = tan θ :=
tan_periodic.sub_eq θ
#align real.angle.tan_sub_pi Real.Angle.tan_sub_pi
@[simp]
theorem tan_toReal (θ : Angle) : Real.tan θ.toReal = tan θ := by
conv_rhs => rw [← coe_toReal θ, tan_coe]
#align real.angle.tan_to_real Real.Angle.tan_toReal
theorem tan_eq_of_two_nsmul_eq {θ ψ : Angle} (h : (2 : ℕ) • θ = (2 : ℕ) • ψ) : tan θ = tan ψ := by
rw [two_nsmul_eq_iff] at h
rcases h with (rfl | rfl)
· rfl
· exact tan_add_pi _
#align real.angle.tan_eq_of_two_nsmul_eq Real.Angle.tan_eq_of_two_nsmul_eq
theorem tan_eq_of_two_zsmul_eq {θ ψ : Angle} (h : (2 : ℤ) • θ = (2 : ℤ) • ψ) : tan θ = tan ψ := by
simp_rw [two_zsmul, ← two_nsmul] at h
exact tan_eq_of_two_nsmul_eq h
#align real.angle.tan_eq_of_two_zsmul_eq Real.Angle.tan_eq_of_two_zsmul_eq
theorem tan_eq_inv_of_two_nsmul_add_two_nsmul_eq_pi {θ ψ : Angle}
(h : (2 : ℕ) • θ + (2 : ℕ) • ψ = π) : tan ψ = (tan θ)⁻¹ := by
induction θ using Real.Angle.induction_on
induction ψ using Real.Angle.induction_on
rw [← smul_add, ← coe_add, ← coe_nsmul, two_nsmul, ← two_mul, angle_eq_iff_two_pi_dvd_sub] at h
rcases h with ⟨k, h⟩
rw [sub_eq_iff_eq_add, ← mul_inv_cancel_left₀ two_ne_zero π, mul_assoc, ← mul_add,
mul_right_inj' (two_ne_zero' ℝ), ← eq_sub_iff_add_eq', mul_inv_cancel_left₀ two_ne_zero π,
inv_mul_eq_div, mul_comm] at h
rw [tan_coe, tan_coe, ← tan_pi_div_two_sub, h, add_sub_assoc, add_comm]
exact Real.tan_periodic.int_mul _ _
#align real.angle.tan_eq_inv_of_two_nsmul_add_two_nsmul_eq_pi Real.Angle.tan_eq_inv_of_two_nsmul_add_two_nsmul_eq_pi
theorem tan_eq_inv_of_two_zsmul_add_two_zsmul_eq_pi {θ ψ : Angle}
(h : (2 : ℤ) • θ + (2 : ℤ) • ψ = π) : tan ψ = (tan θ)⁻¹ := by
simp_rw [two_zsmul, ← two_nsmul] at h
exact tan_eq_inv_of_two_nsmul_add_two_nsmul_eq_pi h
#align real.angle.tan_eq_inv_of_two_zsmul_add_two_zsmul_eq_pi Real.Angle.tan_eq_inv_of_two_zsmul_add_two_zsmul_eq_pi
def sign (θ : Angle) : SignType :=
SignType.sign (sin θ)
#align real.angle.sign Real.Angle.sign
@[simp]
theorem sign_zero : (0 : Angle).sign = 0 := by
rw [sign, sin_zero, _root_.sign_zero]
#align real.angle.sign_zero Real.Angle.sign_zero
@[simp]
theorem sign_coe_pi : (π : Angle).sign = 0 := by rw [sign, sin_coe_pi, _root_.sign_zero]
#align real.angle.sign_coe_pi Real.Angle.sign_coe_pi
@[simp]
| Mathlib/Analysis/SpecialFunctions/Trigonometric/Angle.lean | 867 | 868 | theorem sign_neg (θ : Angle) : (-θ).sign = -θ.sign := by |
simp_rw [sign, sin_neg, Left.sign_neg]
|
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
| Mathlib/MeasureTheory/Function/L1Space.lean | 66 | 67 | 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]
|
import Mathlib.Data.List.OfFn
import Mathlib.Data.List.Range
#align_import data.list.indexes from "leanprover-community/mathlib"@"8631e2d5ea77f6c13054d9151d82b83069680cb1"
assert_not_exists MonoidWithZero
universe u v
open Function
namespace List
variable {α : Type u} {β : Type v}
section MapIdx
-- Porting note: Add back old definition because it's easier for writing proofs.
protected def oldMapIdxCore (f : ℕ → α → β) : ℕ → List α → List β
| _, [] => []
| k, a :: as => f k a :: List.oldMapIdxCore f (k + 1) as
protected def oldMapIdx (f : ℕ → α → β) (as : List α) : List β :=
List.oldMapIdxCore f 0 as
@[simp]
theorem mapIdx_nil {α β} (f : ℕ → α → β) : mapIdx f [] = [] :=
rfl
#align list.map_with_index_nil List.mapIdx_nil
-- Porting note (#10756): new theorem.
protected theorem oldMapIdxCore_eq (l : List α) (f : ℕ → α → β) (n : ℕ) :
l.oldMapIdxCore f n = l.oldMapIdx fun i a ↦ f (i + n) a := by
induction' l with hd tl hl generalizing f n
· rfl
· rw [List.oldMapIdx]
simp only [List.oldMapIdxCore, hl, Nat.add_left_comm, Nat.add_comm, Nat.add_zero]
#noalign list.map_with_index_core_eq
-- Porting note: convert new definition to old definition.
-- A few new theorems are added to achieve this
-- 1. Prove that `oldMapIdxCore f (l ++ [e]) = oldMapIdxCore f l ++ [f l.length e]`
-- 2. Prove that `oldMapIdx f (l ++ [e]) = oldMapIdx f l ++ [f l.length e]`
-- 3. Prove list induction using `∀ l e, p [] → (p l → p (l ++ [e])) → p l`
-- Porting note (#10756): new theorem.
theorem list_reverse_induction (p : List α → Prop) (base : p [])
(ind : ∀ (l : List α) (e : α), p l → p (l ++ [e])) : (∀ (l : List α), p l) := by
let q := fun l ↦ p (reverse l)
have pq : ∀ l, p (reverse l) → q l := by simp only [q, reverse_reverse]; intro; exact id
have qp : ∀ l, q (reverse l) → p l := by simp only [q, reverse_reverse]; intro; exact id
intro l
apply qp
generalize (reverse l) = l
induction' l with head tail ih
· apply pq; simp only [reverse_nil, base]
· apply pq; simp only [reverse_cons]; apply ind; apply qp; rw [reverse_reverse]; exact ih
-- Porting note (#10756): new theorem.
protected theorem oldMapIdxCore_append : ∀ (f : ℕ → α → β) (n : ℕ) (l₁ l₂ : List α),
List.oldMapIdxCore f n (l₁ ++ l₂) =
List.oldMapIdxCore f n l₁ ++ List.oldMapIdxCore f (n + l₁.length) l₂ := by
intros f n l₁ l₂
generalize e : (l₁ ++ l₂).length = len
revert n l₁ l₂
induction' len with len ih <;> intros n l₁ l₂ h
· have l₁_nil : l₁ = [] := by
cases l₁
· rfl
· contradiction
have l₂_nil : l₂ = [] := by
cases l₂
· rfl
· rw [List.length_append] at h; contradiction
simp only [l₁_nil, l₂_nil]; rfl
· cases' l₁ with head tail
· rfl
· simp only [List.oldMapIdxCore, List.append_eq, length_cons, cons_append,cons.injEq, true_and]
suffices n + Nat.succ (length tail) = n + 1 + tail.length by
rw [this]
apply ih (n + 1) _ _ _
simp only [cons_append, length_cons, length_append, Nat.succ.injEq] at h
simp only [length_append, h]
rw [Nat.add_assoc]; simp only [Nat.add_comm]
-- Porting note (#10756): new theorem.
protected theorem oldMapIdx_append : ∀ (f : ℕ → α → β) (l : List α) (e : α),
List.oldMapIdx f (l ++ [e]) = List.oldMapIdx f l ++ [f l.length e] := by
intros f l e
unfold List.oldMapIdx
rw [List.oldMapIdxCore_append f 0 l [e]]
simp only [Nat.zero_add]; rfl
-- Porting note (#10756): new theorem.
theorem mapIdxGo_append : ∀ (f : ℕ → α → β) (l₁ l₂ : List α) (arr : Array β),
mapIdx.go f (l₁ ++ l₂) arr = mapIdx.go f l₂ (List.toArray (mapIdx.go f l₁ arr)) := by
intros f l₁ l₂ arr
generalize e : (l₁ ++ l₂).length = len
revert l₁ l₂ arr
induction' len with len ih <;> intros l₁ l₂ arr h
· have l₁_nil : l₁ = [] := by
cases l₁
· rfl
· contradiction
have l₂_nil : l₂ = [] := by
cases l₂
· rfl
· rw [List.length_append] at h; contradiction
rw [l₁_nil, l₂_nil]; simp only [mapIdx.go, Array.toList_eq, Array.toArray_data]
· cases' l₁ with head tail <;> simp only [mapIdx.go]
· simp only [nil_append, Array.toList_eq, Array.toArray_data]
· simp only [List.append_eq]
rw [ih]
· simp only [cons_append, length_cons, length_append, Nat.succ.injEq] at h
simp only [length_append, h]
-- Porting note (#10756): new theorem.
theorem mapIdxGo_length : ∀ (f : ℕ → α → β) (l : List α) (arr : Array β),
length (mapIdx.go f l arr) = length l + arr.size := by
intro f l
induction' l with head tail ih
· intro; simp only [mapIdx.go, Array.toList_eq, length_nil, Nat.zero_add]
· intro; simp only [mapIdx.go]; rw [ih]; simp only [Array.size_push, length_cons];
simp only [Nat.add_succ, add_zero, Nat.add_comm]
-- Porting note (#10756): new theorem.
theorem mapIdx_append_one : ∀ (f : ℕ → α → β) (l : List α) (e : α),
mapIdx f (l ++ [e]) = mapIdx f l ++ [f l.length e] := by
intros f l e
unfold mapIdx
rw [mapIdxGo_append f l [e]]
simp only [mapIdx.go, Array.size_toArray, mapIdxGo_length, length_nil, Nat.add_zero,
Array.toList_eq, Array.push_data, Array.data_toArray]
-- Porting note (#10756): new theorem.
protected theorem new_def_eq_old_def :
∀ (f : ℕ → α → β) (l : List α), l.mapIdx f = List.oldMapIdx f l := by
intro f
apply list_reverse_induction
· rfl
· intro l e h
rw [List.oldMapIdx_append, mapIdx_append_one, h]
@[local simp]
theorem map_enumFrom_eq_zipWith : ∀ (l : List α) (n : ℕ) (f : ℕ → α → β),
map (uncurry f) (enumFrom n l) = zipWith (fun i ↦ f (i + n)) (range (length l)) l := by
intro l
generalize e : l.length = len
revert l
induction' len with len ih <;> intros l e n f
· have : l = [] := by
cases l
· rfl
· contradiction
rw [this]; rfl
· cases' l with head tail
· contradiction
· simp only [map, uncurry_apply_pair, range_succ_eq_map, zipWith, Nat.zero_add,
zipWith_map_left]
rw [ih]
· suffices (fun i ↦ f (i + (n + 1))) = ((fun i ↦ f (i + n)) ∘ Nat.succ) by
rw [this]
rfl
funext n' a
simp only [comp, Nat.add_assoc, Nat.add_comm, Nat.add_succ]
simp only [length_cons, Nat.succ.injEq] at e; exact e
theorem mapIdx_eq_enum_map (l : List α) (f : ℕ → α → β) :
l.mapIdx f = l.enum.map (Function.uncurry f) := by
rw [List.new_def_eq_old_def]
induction' l with hd tl hl generalizing f
· rfl
· rw [List.oldMapIdx, List.oldMapIdxCore, List.oldMapIdxCore_eq, hl]
simp [map, enum_eq_zip_range, map_uncurry_zip_eq_zipWith]
#align list.map_with_index_eq_enum_map List.mapIdx_eq_enum_map
@[simp]
theorem mapIdx_cons (l : List α) (f : ℕ → α → β) (a : α) :
mapIdx f (a :: l) = f 0 a :: mapIdx (fun i ↦ f (i + 1)) l := by
simp [mapIdx_eq_enum_map, enum_eq_zip_range, map_uncurry_zip_eq_zipWith,
range_succ_eq_map, zipWith_map_left]
#align list.map_with_index_cons List.mapIdx_cons
theorem mapIdx_append (K L : List α) (f : ℕ → α → β) :
(K ++ L).mapIdx f = K.mapIdx f ++ L.mapIdx fun i a ↦ f (i + K.length) a := by
induction' K with a J IH generalizing f
· rfl
· simp [IH fun i ↦ f (i + 1), Nat.add_assoc, Nat.succ_eq_add_one]
#align list.map_with_index_append List.mapIdx_append
@[simp]
theorem length_mapIdx (l : List α) (f : ℕ → α → β) : (l.mapIdx f).length = l.length := by
induction' l with hd tl IH generalizing f
· rfl
· simp [IH]
#align list.length_map_with_index List.length_mapIdx
@[simp]
theorem mapIdx_eq_nil {f : ℕ → α → β} {l : List α} : List.mapIdx f l = [] ↔ l = [] := by
rw [List.mapIdx_eq_enum_map, List.map_eq_nil, List.enum_eq_nil]
set_option linter.deprecated false in
@[simp, deprecated (since := "2023-02-11")]
theorem nthLe_mapIdx (l : List α) (f : ℕ → α → β) (i : ℕ) (h : i < l.length)
(h' : i < (l.mapIdx f).length := h.trans_le (l.length_mapIdx f).ge) :
(l.mapIdx f).nthLe i h' = f i (l.nthLe i h) := by
simp [mapIdx_eq_enum_map, enum_eq_zip_range]
#align list.nth_le_map_with_index List.nthLe_mapIdx
| Mathlib/Data/List/Indexes.lean | 224 | 228 | theorem mapIdx_eq_ofFn (l : List α) (f : ℕ → α → β) :
l.mapIdx f = ofFn fun i : Fin l.length ↦ f (i : ℕ) (l.get i) := by |
induction l generalizing f with
| nil => simp
| cons _ _ IH => simp [IH]
|
import Mathlib.Algebra.Order.Monoid.Unbundled.MinMax
import Mathlib.Algebra.Order.Monoid.WithTop
import Mathlib.Data.Finset.Image
import Mathlib.Data.Multiset.Fold
#align_import data.finset.fold from "leanprover-community/mathlib"@"9003f28797c0664a49e4179487267c494477d853"
-- TODO:
-- assert_not_exists OrderedCommMonoid
assert_not_exists MonoidWithZero
namespace Finset
open Multiset
variable {α β γ : Type*}
section Fold
variable (op : β → β → β) [hc : Std.Commutative op] [ha : Std.Associative op]
local notation a " * " b => op a b
def fold (b : β) (f : α → β) (s : Finset α) : β :=
(s.1.map f).fold op b
#align finset.fold Finset.fold
variable {op} {f : α → β} {b : β} {s : Finset α} {a : α}
@[simp]
theorem fold_empty : (∅ : Finset α).fold op b f = b :=
rfl
#align finset.fold_empty Finset.fold_empty
@[simp]
theorem fold_cons (h : a ∉ s) : (cons a s h).fold op b f = f a * s.fold op b f := by
dsimp only [fold]
rw [cons_val, Multiset.map_cons, fold_cons_left]
#align finset.fold_cons Finset.fold_cons
@[simp]
theorem fold_insert [DecidableEq α] (h : a ∉ s) :
(insert a s).fold op b f = f a * s.fold op b f := by
unfold fold
rw [insert_val, ndinsert_of_not_mem h, Multiset.map_cons, fold_cons_left]
#align finset.fold_insert Finset.fold_insert
@[simp]
theorem fold_singleton : ({a} : Finset α).fold op b f = f a * b :=
rfl
#align finset.fold_singleton Finset.fold_singleton
@[simp]
theorem fold_map {g : γ ↪ α} {s : Finset γ} : (s.map g).fold op b f = s.fold op b (f ∘ g) := by
simp only [fold, map, Multiset.map_map]
#align finset.fold_map Finset.fold_map
@[simp]
theorem fold_image [DecidableEq α] {g : γ → α} {s : Finset γ}
(H : ∀ x ∈ s, ∀ y ∈ s, g x = g y → x = y) : (s.image g).fold op b f = s.fold op b (f ∘ g) := by
simp only [fold, image_val_of_injOn H, Multiset.map_map]
#align finset.fold_image Finset.fold_image
@[congr]
theorem fold_congr {g : α → β} (H : ∀ x ∈ s, f x = g x) : s.fold op b f = s.fold op b g := by
rw [fold, fold, map_congr rfl H]
#align finset.fold_congr Finset.fold_congr
theorem fold_op_distrib {f g : α → β} {b₁ b₂ : β} :
(s.fold op (b₁ * b₂) fun x => f x * g x) = s.fold op b₁ f * s.fold op b₂ g := by
simp only [fold, fold_distrib]
#align finset.fold_op_distrib Finset.fold_op_distrib
theorem fold_const [hd : Decidable (s = ∅)] (c : β) (h : op c (op b c) = op b c) :
Finset.fold op b (fun _ => c) s = if s = ∅ then b else op b c := by
classical
induction' s using Finset.induction_on with x s hx IH generalizing hd
· simp
· simp only [Finset.fold_insert hx, IH, if_false, Finset.insert_ne_empty]
split_ifs
· rw [hc.comm]
· exact h
#align finset.fold_const Finset.fold_const
theorem fold_hom {op' : γ → γ → γ} [Std.Commutative op'] [Std.Associative op'] {m : β → γ}
(hm : ∀ x y, m (op x y) = op' (m x) (m y)) :
(s.fold op' (m b) fun x => m (f x)) = m (s.fold op b f) := by
rw [fold, fold, ← Multiset.fold_hom op hm, Multiset.map_map]
simp only [Function.comp_apply]
#align finset.fold_hom Finset.fold_hom
theorem fold_disjUnion {s₁ s₂ : Finset α} {b₁ b₂ : β} (h) :
(s₁.disjUnion s₂ h).fold op (b₁ * b₂) f = s₁.fold op b₁ f * s₂.fold op b₂ f :=
(congr_arg _ <| Multiset.map_add _ _ _).trans (Multiset.fold_add _ _ _ _ _)
#align finset.fold_disj_union Finset.fold_disjUnion
theorem fold_disjiUnion {ι : Type*} {s : Finset ι} {t : ι → Finset α} {b : ι → β} {b₀ : β} (h) :
(s.disjiUnion t h).fold op (s.fold op b₀ b) f = s.fold op b₀ fun i => (t i).fold op (b i) f :=
(congr_arg _ <| Multiset.map_bind _ _ _).trans (Multiset.fold_bind _ _ _ _ _)
#align finset.fold_disj_Union Finset.fold_disjiUnion
theorem fold_union_inter [DecidableEq α] {s₁ s₂ : Finset α} {b₁ b₂ : β} :
((s₁ ∪ s₂).fold op b₁ f * (s₁ ∩ s₂).fold op b₂ f) = s₁.fold op b₂ f * s₂.fold op b₁ f := by
unfold fold
rw [← fold_add op, ← Multiset.map_add, union_val, inter_val, union_add_inter, Multiset.map_add,
hc.comm, fold_add]
#align finset.fold_union_inter Finset.fold_union_inter
@[simp]
theorem fold_insert_idem [DecidableEq α] [hi : Std.IdempotentOp op] :
(insert a s).fold op b f = f a * s.fold op b f := by
by_cases h : a ∈ s
· rw [← insert_erase h]
simp [← ha.assoc, hi.idempotent]
· apply fold_insert h
#align finset.fold_insert_idem Finset.fold_insert_idem
theorem fold_image_idem [DecidableEq α] {g : γ → α} {s : Finset γ} [hi : Std.IdempotentOp op] :
(image g s).fold op b f = s.fold op b (f ∘ g) := by
induction' s using Finset.cons_induction with x xs hx ih
· rw [fold_empty, image_empty, fold_empty]
· haveI := Classical.decEq γ
rw [fold_cons, cons_eq_insert, image_insert, fold_insert_idem, ih]
simp only [Function.comp_apply]
#align finset.fold_image_idem Finset.fold_image_idem
theorem fold_ite' {g : α → β} (hb : op b b = b) (p : α → Prop) [DecidablePred p] :
Finset.fold op b (fun i => ite (p i) (f i) (g i)) s =
op (Finset.fold op b f (s.filter p)) (Finset.fold op b g (s.filter fun i => ¬p i)) := by
classical
induction' s using Finset.induction_on with x s hx IH
· simp [hb]
· simp only [Finset.fold_insert hx]
split_ifs with h
· have : x ∉ Finset.filter p s := by simp [hx]
simp [Finset.filter_insert, h, Finset.fold_insert this, ha.assoc, IH]
· have : x ∉ Finset.filter (fun i => ¬ p i) s := by simp [hx]
simp [Finset.filter_insert, h, Finset.fold_insert this, IH, ← ha.assoc, hc.comm]
#align finset.fold_ite' Finset.fold_ite'
theorem fold_ite [Std.IdempotentOp op] {g : α → β} (p : α → Prop) [DecidablePred p] :
Finset.fold op b (fun i => ite (p i) (f i) (g i)) s =
op (Finset.fold op b f (s.filter p)) (Finset.fold op b g (s.filter fun i => ¬p i)) :=
fold_ite' (Std.IdempotentOp.idempotent _) _
#align finset.fold_ite Finset.fold_ite
theorem fold_op_rel_iff_and {r : β → β → Prop} (hr : ∀ {x y z}, r x (op y z) ↔ r x y ∧ r x z)
{c : β} : r c (s.fold op b f) ↔ r c b ∧ ∀ x ∈ s, r c (f x) := by
classical
induction' s using Finset.induction_on with a s ha IH
· simp
rw [Finset.fold_insert ha, hr, IH, ← and_assoc, @and_comm (r c (f a)), and_assoc]
apply and_congr Iff.rfl
constructor
· rintro ⟨h₁, h₂⟩
intro b hb
rw [Finset.mem_insert] at hb
rcases hb with (rfl | hb) <;> solve_by_elim
· intro h
constructor
· exact h a (Finset.mem_insert_self _ _)
· exact fun b hb => h b <| Finset.mem_insert_of_mem hb
#align finset.fold_op_rel_iff_and Finset.fold_op_rel_iff_and
theorem fold_op_rel_iff_or {r : β → β → Prop} (hr : ∀ {x y z}, r x (op y z) ↔ r x y ∨ r x z)
{c : β} : r c (s.fold op b f) ↔ r c b ∨ ∃ x ∈ s, r c (f x) := by
classical
induction' s using Finset.induction_on with a s ha IH
· simp
rw [Finset.fold_insert ha, hr, IH, ← or_assoc, @or_comm (r c (f a)), or_assoc]
apply or_congr Iff.rfl
constructor
· rintro (h₁ | ⟨x, hx, h₂⟩)
· use a
simp [h₁]
· refine ⟨x, by simp [hx], h₂⟩
· rintro ⟨x, hx, h⟩
exact (mem_insert.mp hx).imp (fun hx => by rwa [hx] at h) (fun hx => ⟨x, hx, h⟩)
#align finset.fold_op_rel_iff_or Finset.fold_op_rel_iff_or
@[simp]
theorem fold_union_empty_singleton [DecidableEq α] (s : Finset α) :
Finset.fold (· ∪ ·) ∅ singleton s = s := by
induction' s using Finset.induction_on with a s has ih
· simp only [fold_empty]
· rw [fold_insert has, ih, insert_eq]
#align finset.fold_union_empty_singleton Finset.fold_union_empty_singleton
theorem fold_sup_bot_singleton [DecidableEq α] (s : Finset α) :
Finset.fold (· ⊔ ·) ⊥ singleton s = s :=
fold_union_empty_singleton s
#align finset.fold_sup_bot_singleton Finset.fold_sup_bot_singleton
section Order
variable [LinearOrder β] (c : β)
theorem le_fold_min : c ≤ s.fold min b f ↔ c ≤ b ∧ ∀ x ∈ s, c ≤ f x :=
fold_op_rel_iff_and le_min_iff
#align finset.le_fold_min Finset.le_fold_min
theorem fold_min_le : s.fold min b f ≤ c ↔ b ≤ c ∨ ∃ x ∈ s, f x ≤ c := by
show _ ≥ _ ↔ _
apply fold_op_rel_iff_or
intro x y z
show _ ≤ _ ↔ _
exact min_le_iff
#align finset.fold_min_le Finset.fold_min_le
theorem lt_fold_min : c < s.fold min b f ↔ c < b ∧ ∀ x ∈ s, c < f x :=
fold_op_rel_iff_and lt_min_iff
#align finset.lt_fold_min Finset.lt_fold_min
theorem fold_min_lt : s.fold min b f < c ↔ b < c ∨ ∃ x ∈ s, f x < c := by
show _ > _ ↔ _
apply fold_op_rel_iff_or
intro x y z
show _ < _ ↔ _
exact min_lt_iff
#align finset.fold_min_lt Finset.fold_min_lt
theorem fold_max_le : s.fold max b f ≤ c ↔ b ≤ c ∧ ∀ x ∈ s, f x ≤ c := by
show _ ≥ _ ↔ _
apply fold_op_rel_iff_and
intro x y z
show _ ≤ _ ↔ _
exact max_le_iff
#align finset.fold_max_le Finset.fold_max_le
theorem le_fold_max : c ≤ s.fold max b f ↔ c ≤ b ∨ ∃ x ∈ s, c ≤ f x :=
fold_op_rel_iff_or le_max_iff
#align finset.le_fold_max Finset.le_fold_max
| Mathlib/Data/Finset/Fold.lean | 255 | 260 | theorem fold_max_lt : s.fold max b f < c ↔ b < c ∧ ∀ x ∈ s, f x < c := by |
show _ > _ ↔ _
apply fold_op_rel_iff_and
intro x y z
show _ < _ ↔ _
exact max_lt_iff
|
import Mathlib.Analysis.SpecialFunctions.Pow.Continuity
import Mathlib.Analysis.SpecialFunctions.Complex.LogDeriv
import Mathlib.Analysis.Calculus.FDeriv.Extend
import Mathlib.Analysis.Calculus.Deriv.Prod
import Mathlib.Analysis.SpecialFunctions.Log.Deriv
import Mathlib.Analysis.SpecialFunctions.Trigonometric.Deriv
#align_import analysis.special_functions.pow.deriv from "leanprover-community/mathlib"@"3bce8d800a6f2b8f63fe1e588fd76a9ff4adcebe"
noncomputable section
open scoped Classical Real Topology NNReal ENNReal Filter
open Filter
namespace Real
variable {x y z : ℝ}
theorem hasStrictFDerivAt_rpow_of_pos (p : ℝ × ℝ) (hp : 0 < p.1) :
HasStrictFDerivAt (fun x : ℝ × ℝ => x.1 ^ x.2)
((p.2 * p.1 ^ (p.2 - 1)) • ContinuousLinearMap.fst ℝ ℝ ℝ +
(p.1 ^ p.2 * log p.1) • ContinuousLinearMap.snd ℝ ℝ ℝ) p := by
have : (fun x : ℝ × ℝ => x.1 ^ x.2) =ᶠ[𝓝 p] fun x => exp (log x.1 * x.2) :=
(continuousAt_fst.eventually (lt_mem_nhds hp)).mono fun p hp => rpow_def_of_pos hp _
refine HasStrictFDerivAt.congr_of_eventuallyEq ?_ this.symm
convert ((hasStrictFDerivAt_fst.log hp.ne').mul hasStrictFDerivAt_snd).exp using 1
rw [rpow_sub_one hp.ne', ← rpow_def_of_pos hp, smul_add, smul_smul, mul_div_left_comm,
div_eq_mul_inv, smul_smul, smul_smul, mul_assoc, add_comm]
#align real.has_strict_fderiv_at_rpow_of_pos Real.hasStrictFDerivAt_rpow_of_pos
theorem hasStrictFDerivAt_rpow_of_neg (p : ℝ × ℝ) (hp : p.1 < 0) :
HasStrictFDerivAt (fun x : ℝ × ℝ => x.1 ^ x.2)
((p.2 * p.1 ^ (p.2 - 1)) • ContinuousLinearMap.fst ℝ ℝ ℝ +
(p.1 ^ p.2 * log p.1 - exp (log p.1 * p.2) * sin (p.2 * π) * π) •
ContinuousLinearMap.snd ℝ ℝ ℝ) p := by
have : (fun x : ℝ × ℝ => x.1 ^ x.2) =ᶠ[𝓝 p] fun x => exp (log x.1 * x.2) * cos (x.2 * π) :=
(continuousAt_fst.eventually (gt_mem_nhds hp)).mono fun p hp => rpow_def_of_neg hp _
refine HasStrictFDerivAt.congr_of_eventuallyEq ?_ this.symm
convert ((hasStrictFDerivAt_fst.log hp.ne).mul hasStrictFDerivAt_snd).exp.mul
(hasStrictFDerivAt_snd.mul_const π).cos using 1
simp_rw [rpow_sub_one hp.ne, smul_add, ← add_assoc, smul_smul, ← add_smul, ← mul_assoc,
mul_comm (cos _), ← rpow_def_of_neg hp]
rw [div_eq_mul_inv, add_comm]; congr 2 <;> ring
#align real.has_strict_fderiv_at_rpow_of_neg Real.hasStrictFDerivAt_rpow_of_neg
theorem contDiffAt_rpow_of_ne (p : ℝ × ℝ) (hp : p.1 ≠ 0) {n : ℕ∞} :
ContDiffAt ℝ n (fun p : ℝ × ℝ => p.1 ^ p.2) p := by
cases' hp.lt_or_lt with hneg hpos
exacts
[(((contDiffAt_fst.log hneg.ne).mul contDiffAt_snd).exp.mul
(contDiffAt_snd.mul contDiffAt_const).cos).congr_of_eventuallyEq
((continuousAt_fst.eventually (gt_mem_nhds hneg)).mono fun p hp => rpow_def_of_neg hp _),
((contDiffAt_fst.log hpos.ne').mul contDiffAt_snd).exp.congr_of_eventuallyEq
((continuousAt_fst.eventually (lt_mem_nhds hpos)).mono fun p hp => rpow_def_of_pos hp _)]
#align real.cont_diff_at_rpow_of_ne Real.contDiffAt_rpow_of_ne
theorem differentiableAt_rpow_of_ne (p : ℝ × ℝ) (hp : p.1 ≠ 0) :
DifferentiableAt ℝ (fun p : ℝ × ℝ => p.1 ^ p.2) p :=
(contDiffAt_rpow_of_ne p hp).differentiableAt le_rfl
#align real.differentiable_at_rpow_of_ne Real.differentiableAt_rpow_of_ne
| Mathlib/Analysis/SpecialFunctions/Pow/Deriv.lean | 321 | 326 | theorem _root_.HasStrictDerivAt.rpow {f g : ℝ → ℝ} {f' g' : ℝ} (hf : HasStrictDerivAt f f' x)
(hg : HasStrictDerivAt g g' x) (h : 0 < f x) : HasStrictDerivAt (fun x => f x ^ g x)
(f' * g x * f x ^ (g x - 1) + g' * f x ^ g x * Real.log (f x)) x := by |
convert (hasStrictFDerivAt_rpow_of_pos ((fun x => (f x, g x)) x) h).comp_hasStrictDerivAt x
(hf.prod hg) using 1
simp [mul_assoc, mul_comm, mul_left_comm]
|
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