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.Algebra.MvPolynomial.PDeriv
import Mathlib.Algebra.Polynomial.AlgebraMap
import Mathlib.Algebra.Polynomial.Derivative
import Mathlib.Data.Nat.Choose.Sum
import Mathlib.LinearAlgebra.LinearIndependent
import Mathlib.RingTheory.Polynomial.Pochhammer
#align_import ring_theory.polynomial.bernstein from "leanprover-community/mathlib"@"bbeb185db4ccee8ed07dc48449414ebfa39cb821"
noncomputable section
open Nat (choose)
open Polynomial (X)
open scoped Polynomial
variable (R : Type*) [CommRing R]
def bernsteinPolynomial (n ν : ℕ) : R[X] :=
(choose n ν : R[X]) * X ^ ν * (1 - X) ^ (n - ν)
#align bernstein_polynomial bernsteinPolynomial
example : bernsteinPolynomial ℤ 3 2 = 3 * X ^ 2 - 3 * X ^ 3 := by
norm_num [bernsteinPolynomial, choose]
ring
namespace bernsteinPolynomial
theorem eq_zero_of_lt {n ν : ℕ} (h : n < ν) : bernsteinPolynomial R n ν = 0 := by
simp [bernsteinPolynomial, Nat.choose_eq_zero_of_lt h]
#align bernstein_polynomial.eq_zero_of_lt bernsteinPolynomial.eq_zero_of_lt
section
variable {R} {S : Type*} [CommRing S]
@[simp]
theorem map (f : R →+* S) (n ν : ℕ) :
(bernsteinPolynomial R n ν).map f = bernsteinPolynomial S n ν := by simp [bernsteinPolynomial]
#align bernstein_polynomial.map bernsteinPolynomial.map
end
theorem flip (n ν : ℕ) (h : ν ≤ n) :
(bernsteinPolynomial R n ν).comp (1 - X) = bernsteinPolynomial R n (n - ν) := by
simp [bernsteinPolynomial, h, tsub_tsub_assoc, mul_right_comm]
#align bernstein_polynomial.flip bernsteinPolynomial.flip
theorem flip' (n ν : ℕ) (h : ν ≤ n) :
bernsteinPolynomial R n ν = (bernsteinPolynomial R n (n - ν)).comp (1 - X) := by
simp [← flip _ _ _ h, Polynomial.comp_assoc]
#align bernstein_polynomial.flip' bernsteinPolynomial.flip'
theorem eval_at_0 (n ν : ℕ) : (bernsteinPolynomial R n ν).eval 0 = if ν = 0 then 1 else 0 := by
rw [bernsteinPolynomial]
split_ifs with h
· subst h; simp
· simp [zero_pow h]
#align bernstein_polynomial.eval_at_0 bernsteinPolynomial.eval_at_0
theorem eval_at_1 (n ν : ℕ) : (bernsteinPolynomial R n ν).eval 1 = if ν = n then 1 else 0 := by
rw [bernsteinPolynomial]
split_ifs with h
· subst h; simp
· obtain hνn | hnν := Ne.lt_or_lt h
· simp [zero_pow $ Nat.sub_ne_zero_of_lt hνn]
· simp [Nat.choose_eq_zero_of_lt hnν]
#align bernstein_polynomial.eval_at_1 bernsteinPolynomial.eval_at_1
theorem derivative_succ_aux (n ν : ℕ) :
Polynomial.derivative (bernsteinPolynomial R (n + 1) (ν + 1)) =
(n + 1) * (bernsteinPolynomial R n ν - bernsteinPolynomial R n (ν + 1)) := by
rw [bernsteinPolynomial]
suffices ((n + 1).choose (ν + 1) : R[X]) * ((↑(ν + 1 : ℕ) : R[X]) * X ^ ν) * (1 - X) ^ (n - ν) -
((n + 1).choose (ν + 1) : R[X]) * X ^ (ν + 1) * ((↑(n - ν) : R[X]) * (1 - X) ^ (n - ν - 1)) =
(↑(n + 1) : R[X]) * ((n.choose ν : R[X]) * X ^ ν * (1 - X) ^ (n - ν) -
(n.choose (ν + 1) : R[X]) * X ^ (ν + 1) * (1 - X) ^ (n - (ν + 1))) by
simpa [Polynomial.derivative_pow, ← sub_eq_add_neg, Nat.succ_sub_succ_eq_sub,
Polynomial.derivative_mul, Polynomial.derivative_natCast, zero_mul,
Nat.cast_add, algebraMap.coe_one, Polynomial.derivative_X, mul_one, zero_add,
Polynomial.derivative_sub, Polynomial.derivative_one, zero_sub, mul_neg, Nat.sub_zero,
bernsteinPolynomial, map_add, map_natCast, Nat.cast_one]
conv_rhs => rw [mul_sub]
-- We'll prove the two terms match up separately.
refine congr (congr_arg Sub.sub ?_) ?_
· simp only [← mul_assoc]
apply congr (congr_arg (· * ·) (congr (congr_arg (· * ·) _) rfl)) rfl
-- Now it's just about binomial coefficients
exact mod_cast congr_arg (fun m : ℕ => (m : R[X])) (Nat.succ_mul_choose_eq n ν).symm
· rw [← tsub_add_eq_tsub_tsub, ← mul_assoc, ← mul_assoc]; congr 1
rw [mul_comm, ← mul_assoc, ← mul_assoc]; congr 1
norm_cast
congr 1
convert (Nat.choose_mul_succ_eq n (ν + 1)).symm using 1
· -- Porting note: was
-- convert mul_comm _ _ using 2
-- simp
rw [mul_comm, Nat.succ_sub_succ_eq_sub]
· apply mul_comm
#align bernstein_polynomial.derivative_succ_aux bernsteinPolynomial.derivative_succ_aux
theorem derivative_succ (n ν : ℕ) : Polynomial.derivative (bernsteinPolynomial R n (ν + 1)) =
n * (bernsteinPolynomial R (n - 1) ν - bernsteinPolynomial R (n - 1) (ν + 1)) := by
cases n
· simp [bernsteinPolynomial]
· rw [Nat.cast_succ]; apply derivative_succ_aux
#align bernstein_polynomial.derivative_succ bernsteinPolynomial.derivative_succ
theorem derivative_zero (n : ℕ) :
Polynomial.derivative (bernsteinPolynomial R n 0) = -n * bernsteinPolynomial R (n - 1) 0 := by
simp [bernsteinPolynomial, Polynomial.derivative_pow]
#align bernstein_polynomial.derivative_zero bernsteinPolynomial.derivative_zero
theorem iterate_derivative_at_0_eq_zero_of_lt (n : ℕ) {ν k : ℕ} :
k < ν → (Polynomial.derivative^[k] (bernsteinPolynomial R n ν)).eval 0 = 0 := by
cases' ν with ν
· rintro ⟨⟩
· rw [Nat.lt_succ_iff]
induction' k with k ih generalizing n ν
· simp [eval_at_0]
· simp only [derivative_succ, Int.natCast_eq_zero, mul_eq_zero, Function.comp_apply,
Function.iterate_succ, Polynomial.iterate_derivative_sub,
Polynomial.iterate_derivative_natCast_mul, Polynomial.eval_mul, Polynomial.eval_natCast,
Polynomial.eval_sub]
intro h
apply mul_eq_zero_of_right
rw [ih _ _ (Nat.le_of_succ_le h), sub_zero]
convert ih _ _ (Nat.pred_le_pred h)
exact (Nat.succ_pred_eq_of_pos (k.succ_pos.trans_le h)).symm
#align bernstein_polynomial.iterate_derivative_at_0_eq_zero_of_lt bernsteinPolynomial.iterate_derivative_at_0_eq_zero_of_lt
@[simp]
theorem iterate_derivative_succ_at_0_eq_zero (n ν : ℕ) :
(Polynomial.derivative^[ν] (bernsteinPolynomial R n (ν + 1))).eval 0 = 0 :=
iterate_derivative_at_0_eq_zero_of_lt R n (lt_add_one ν)
#align bernstein_polynomial.iterate_derivative_succ_at_0_eq_zero bernsteinPolynomial.iterate_derivative_succ_at_0_eq_zero
open Polynomial
@[simp]
theorem iterate_derivative_at_0 (n ν : ℕ) :
(Polynomial.derivative^[ν] (bernsteinPolynomial R n ν)).eval 0 =
(ascPochhammer R ν).eval ((n - (ν - 1) : ℕ) : R) := by
by_cases h : ν ≤ n
· induction' ν with ν ih generalizing n
· simp [eval_at_0]
· have h' : ν ≤ n - 1 := le_tsub_of_add_le_right h
simp only [derivative_succ, ih (n - 1) h', iterate_derivative_succ_at_0_eq_zero,
Nat.succ_sub_succ_eq_sub, tsub_zero, sub_zero, iterate_derivative_sub,
iterate_derivative_natCast_mul, eval_one, eval_mul, eval_add, eval_sub, eval_X, eval_comp,
eval_natCast, Function.comp_apply, Function.iterate_succ, ascPochhammer_succ_left]
obtain rfl | h'' := ν.eq_zero_or_pos
· simp
· have : n - 1 - (ν - 1) = n - ν := by
rw [gt_iff_lt, ← Nat.succ_le_iff] at h''
rw [← tsub_add_eq_tsub_tsub, add_comm, tsub_add_cancel_of_le h'']
rw [this, ascPochhammer_eval_succ]
rw_mod_cast [tsub_add_cancel_of_le (h'.trans n.pred_le)]
· simp only [not_le] at h
rw [tsub_eq_zero_iff_le.mpr (Nat.le_sub_one_of_lt h), eq_zero_of_lt R h]
simp [pos_iff_ne_zero.mp (pos_of_gt h)]
#align bernstein_polynomial.iterate_derivative_at_0 bernsteinPolynomial.iterate_derivative_at_0
theorem iterate_derivative_at_0_ne_zero [CharZero R] (n ν : ℕ) (h : ν ≤ n) :
(Polynomial.derivative^[ν] (bernsteinPolynomial R n ν)).eval 0 ≠ 0 := by
simp only [Int.natCast_eq_zero, bernsteinPolynomial.iterate_derivative_at_0, Ne, Nat.cast_eq_zero]
simp only [← ascPochhammer_eval_cast]
norm_cast
apply ne_of_gt
obtain rfl | h' := Nat.eq_zero_or_pos ν
· simp
· rw [← Nat.succ_pred_eq_of_pos h'] at h
exact ascPochhammer_pos _ _ (tsub_pos_of_lt (Nat.lt_of_succ_le h))
#align bernstein_polynomial.iterate_derivative_at_0_ne_zero bernsteinPolynomial.iterate_derivative_at_0_ne_zero
theorem iterate_derivative_at_1_eq_zero_of_lt (n : ℕ) {ν k : ℕ} :
k < n - ν → (Polynomial.derivative^[k] (bernsteinPolynomial R n ν)).eval 1 = 0 := by
intro w
rw [flip' _ _ _ (tsub_pos_iff_lt.mp (pos_of_gt w)).le]
simp [Polynomial.eval_comp, iterate_derivative_at_0_eq_zero_of_lt R n w]
#align bernstein_polynomial.iterate_derivative_at_1_eq_zero_of_lt bernsteinPolynomial.iterate_derivative_at_1_eq_zero_of_lt
@[simp]
theorem iterate_derivative_at_1 (n ν : ℕ) (h : ν ≤ n) :
(Polynomial.derivative^[n - ν] (bernsteinPolynomial R n ν)).eval 1 =
(-1) ^ (n - ν) * (ascPochhammer R (n - ν)).eval (ν + 1 : R) := by
rw [flip' _ _ _ h]
simp [Polynomial.eval_comp, h]
obtain rfl | h' := h.eq_or_lt
· simp
· norm_cast
congr
omega
#align bernstein_polynomial.iterate_derivative_at_1 bernsteinPolynomial.iterate_derivative_at_1
| Mathlib/RingTheory/Polynomial/Bernstein.lean | 234 | 238 | theorem iterate_derivative_at_1_ne_zero [CharZero R] (n ν : ℕ) (h : ν ≤ n) :
(Polynomial.derivative^[n - ν] (bernsteinPolynomial R n ν)).eval 1 ≠ 0 := by |
rw [bernsteinPolynomial.iterate_derivative_at_1 _ _ _ h, Ne, neg_one_pow_mul_eq_zero_iff, ←
Nat.cast_succ, ← ascPochhammer_eval_cast, ← Nat.cast_zero, Nat.cast_inj]
exact (ascPochhammer_pos _ _ (Nat.succ_pos ν)).ne'
|
import Mathlib.Algebra.Group.Aut
import Mathlib.Algebra.Group.Subgroup.Basic
import Mathlib.Logic.Function.Basic
#align_import group_theory.semidirect_product from "leanprover-community/mathlib"@"f7fc89d5d5ff1db2d1242c7bb0e9062ce47ef47c"
variable (N : Type*) (G : Type*) {H : Type*} [Group N] [Group G] [Group H]
@[ext]
structure SemidirectProduct (φ : G →* MulAut N) where
left : N
right : G
deriving DecidableEq
#align semidirect_product SemidirectProduct
-- Porting note: these lemmas are autogenerated by the inductive definition and are not
-- in simple form due to the existence of mk_eq_inl_mul_inr
attribute [nolint simpNF] SemidirectProduct.mk.injEq
attribute [nolint simpNF] SemidirectProduct.mk.sizeOf_spec
-- Porting note: unknown attribute
-- attribute [pp_using_anonymous_constructor] SemidirectProduct
@[inherit_doc]
notation:35 N " ⋊[" φ:35 "] " G:35 => SemidirectProduct N G φ
namespace SemidirectProduct
variable {N G}
variable {φ : G →* MulAut N}
instance : Mul (SemidirectProduct N G φ) where
mul a b := ⟨a.1 * φ a.2 b.1, a.2 * b.2⟩
lemma mul_def (a b : SemidirectProduct N G φ) : a * b = ⟨a.1 * φ a.2 b.1, a.2 * b.2⟩ := rfl
@[simp]
theorem mul_left (a b : N ⋊[φ] G) : (a * b).left = a.left * φ a.right b.left := rfl
#align semidirect_product.mul_left SemidirectProduct.mul_left
@[simp]
theorem mul_right (a b : N ⋊[φ] G) : (a * b).right = a.right * b.right := rfl
#align semidirect_product.mul_right SemidirectProduct.mul_right
instance : One (SemidirectProduct N G φ) where one := ⟨1, 1⟩
@[simp]
theorem one_left : (1 : N ⋊[φ] G).left = 1 := rfl
#align semidirect_product.one_left SemidirectProduct.one_left
@[simp]
theorem one_right : (1 : N ⋊[φ] G).right = 1 := rfl
#align semidirect_product.one_right SemidirectProduct.one_right
instance : Inv (SemidirectProduct N G φ) where
inv x := ⟨φ x.2⁻¹ x.1⁻¹, x.2⁻¹⟩
@[simp]
theorem inv_left (a : N ⋊[φ] G) : a⁻¹.left = φ a.right⁻¹ a.left⁻¹ := rfl
#align semidirect_product.inv_left SemidirectProduct.inv_left
@[simp]
theorem inv_right (a : N ⋊[φ] G) : a⁻¹.right = a.right⁻¹ := rfl
#align semidirect_product.inv_right SemidirectProduct.inv_right
instance : Group (N ⋊[φ] G) where
mul_assoc a b c := SemidirectProduct.ext _ _ (by simp [mul_assoc]) (by simp [mul_assoc])
one_mul a := SemidirectProduct.ext _ _ (by simp) (one_mul a.2)
mul_one a := SemidirectProduct.ext _ _ (by simp) (mul_one _)
mul_left_inv a := SemidirectProduct.ext _ _ (by simp) (by simp)
instance : Inhabited (N ⋊[φ] G) := ⟨1⟩
def inl : N →* N ⋊[φ] G where
toFun n := ⟨n, 1⟩
map_one' := rfl
map_mul' := by intros; ext <;>
simp only [mul_left, map_one, MulAut.one_apply, mul_right, mul_one]
#align semidirect_product.inl SemidirectProduct.inl
@[simp]
theorem left_inl (n : N) : (inl n : N ⋊[φ] G).left = n := rfl
#align semidirect_product.left_inl SemidirectProduct.left_inl
@[simp]
theorem right_inl (n : N) : (inl n : N ⋊[φ] G).right = 1 := rfl
#align semidirect_product.right_inl SemidirectProduct.right_inl
theorem inl_injective : Function.Injective (inl : N → N ⋊[φ] G) :=
Function.injective_iff_hasLeftInverse.2 ⟨left, left_inl⟩
#align semidirect_product.inl_injective SemidirectProduct.inl_injective
@[simp]
theorem inl_inj {n₁ n₂ : N} : (inl n₁ : N ⋊[φ] G) = inl n₂ ↔ n₁ = n₂ :=
inl_injective.eq_iff
#align semidirect_product.inl_inj SemidirectProduct.inl_inj
def inr : G →* N ⋊[φ] G where
toFun g := ⟨1, g⟩
map_one' := rfl
map_mul' := by intros; ext <;> simp
#align semidirect_product.inr SemidirectProduct.inr
@[simp]
theorem left_inr (g : G) : (inr g : N ⋊[φ] G).left = 1 := rfl
#align semidirect_product.left_inr SemidirectProduct.left_inr
@[simp]
theorem right_inr (g : G) : (inr g : N ⋊[φ] G).right = g := rfl
#align semidirect_product.right_inr SemidirectProduct.right_inr
theorem inr_injective : Function.Injective (inr : G → N ⋊[φ] G) :=
Function.injective_iff_hasLeftInverse.2 ⟨right, right_inr⟩
#align semidirect_product.inr_injective SemidirectProduct.inr_injective
@[simp]
theorem inr_inj {g₁ g₂ : G} : (inr g₁ : N ⋊[φ] G) = inr g₂ ↔ g₁ = g₂ :=
inr_injective.eq_iff
#align semidirect_product.inr_inj SemidirectProduct.inr_inj
theorem inl_aut (g : G) (n : N) : (inl (φ g n) : N ⋊[φ] G) = inr g * inl n * inr g⁻¹ := by
ext <;> simp
#align semidirect_product.inl_aut SemidirectProduct.inl_aut
theorem inl_aut_inv (g : G) (n : N) : (inl ((φ g)⁻¹ n) : N ⋊[φ] G) = inr g⁻¹ * inl n * inr g := by
rw [← MonoidHom.map_inv, inl_aut, inv_inv]
#align semidirect_product.inl_aut_inv SemidirectProduct.inl_aut_inv
@[simp]
| Mathlib/GroupTheory/SemidirectProduct.lean | 166 | 166 | theorem mk_eq_inl_mul_inr (g : G) (n : N) : (⟨n, g⟩ : N ⋊[φ] G) = inl n * inr g := by | ext <;> simp
|
import Mathlib.Algebra.MvPolynomial.Supported
import Mathlib.RingTheory.WittVector.Truncated
#align_import ring_theory.witt_vector.mul_coeff from "leanprover-community/mathlib"@"2f5b500a507264de86d666a5f87ddb976e2d8de4"
noncomputable section
namespace WittVector
variable (p : ℕ) [hp : Fact p.Prime]
variable {k : Type*} [CommRing k]
local notation "𝕎" => WittVector p
-- Porting note: new notation
local notation "𝕄" => MvPolynomial (Fin 2 × ℕ) ℤ
open Finset MvPolynomial
def wittPolyProd (n : ℕ) : 𝕄 :=
rename (Prod.mk (0 : Fin 2)) (wittPolynomial p ℤ n) *
rename (Prod.mk (1 : Fin 2)) (wittPolynomial p ℤ n)
#align witt_vector.witt_poly_prod WittVector.wittPolyProd
theorem wittPolyProd_vars (n : ℕ) : (wittPolyProd p n).vars ⊆ univ ×ˢ range (n + 1) := by
rw [wittPolyProd]
apply Subset.trans (vars_mul _ _)
refine union_subset ?_ ?_ <;>
· refine Subset.trans (vars_rename _ _) ?_
simp [wittPolynomial_vars, image_subset_iff]
#align witt_vector.witt_poly_prod_vars WittVector.wittPolyProd_vars
def wittPolyProdRemainder (n : ℕ) : 𝕄 :=
∑ i ∈ range n, (p : 𝕄) ^ i * wittMul p i ^ p ^ (n - i)
#align witt_vector.witt_poly_prod_remainder WittVector.wittPolyProdRemainder
theorem wittPolyProdRemainder_vars (n : ℕ) :
(wittPolyProdRemainder p n).vars ⊆ univ ×ˢ range n := by
rw [wittPolyProdRemainder]
refine Subset.trans (vars_sum_subset _ _) ?_
rw [biUnion_subset]
intro x hx
apply Subset.trans (vars_mul _ _)
refine union_subset ?_ ?_
· apply Subset.trans (vars_pow _ _)
have : (p : 𝕄) = C (p : ℤ) := by simp only [Int.cast_natCast, eq_intCast]
rw [this, vars_C]
apply empty_subset
· apply Subset.trans (vars_pow _ _)
apply Subset.trans (wittMul_vars _ _)
apply product_subset_product (Subset.refl _)
simp only [mem_range, range_subset] at hx ⊢
exact hx
#align witt_vector.witt_poly_prod_remainder_vars WittVector.wittPolyProdRemainder_vars
def remainder (n : ℕ) : 𝕄 :=
(∑ x ∈ range (n + 1),
(rename (Prod.mk 0)) ((monomial (Finsupp.single x (p ^ (n + 1 - x)))) ((p : ℤ) ^ x))) *
∑ x ∈ range (n + 1),
(rename (Prod.mk 1)) ((monomial (Finsupp.single x (p ^ (n + 1 - x)))) ((p : ℤ) ^ x))
#align witt_vector.remainder WittVector.remainder
theorem remainder_vars (n : ℕ) : (remainder p n).vars ⊆ univ ×ˢ range (n + 1) := by
rw [remainder]
apply Subset.trans (vars_mul _ _)
refine union_subset ?_ ?_ <;>
· refine Subset.trans (vars_sum_subset _ _) ?_
rw [biUnion_subset]
intro x hx
rw [rename_monomial, vars_monomial, Finsupp.mapDomain_single]
· apply Subset.trans Finsupp.support_single_subset
simpa using mem_range.mp hx
· apply pow_ne_zero
exact mod_cast hp.out.ne_zero
#align witt_vector.remainder_vars WittVector.remainder_vars
def polyOfInterest (n : ℕ) : 𝕄 :=
wittMul p (n + 1) + (p : 𝕄) ^ (n + 1) * X (0, n + 1) * X (1, n + 1) -
X (0, n + 1) * rename (Prod.mk (1 : Fin 2)) (wittPolynomial p ℤ (n + 1)) -
X (1, n + 1) * rename (Prod.mk (0 : Fin 2)) (wittPolynomial p ℤ (n + 1))
#align witt_vector.poly_of_interest WittVector.polyOfInterest
theorem mul_polyOfInterest_aux1 (n : ℕ) :
∑ i ∈ range (n + 1), (p : 𝕄) ^ i * wittMul p i ^ p ^ (n - i) = wittPolyProd p n := by
simp only [wittPolyProd]
convert wittStructureInt_prop p (X (0 : Fin 2) * X 1) n using 1
· simp only [wittPolynomial, wittMul]
rw [AlgHom.map_sum]
congr 1 with i
congr 1
have hsupp : (Finsupp.single i (p ^ (n - i))).support = {i} := by
rw [Finsupp.support_eq_singleton]
simp only [and_true_iff, Finsupp.single_eq_same, eq_self_iff_true, Ne]
exact pow_ne_zero _ hp.out.ne_zero
simp only [bind₁_monomial, hsupp, Int.cast_natCast, prod_singleton, eq_intCast,
Finsupp.single_eq_same, C_pow, mul_eq_mul_left_iff, true_or_iff, eq_self_iff_true,
Int.cast_pow]
· simp only [map_mul, bind₁_X_right]
#align witt_vector.mul_poly_of_interest_aux1 WittVector.mul_polyOfInterest_aux1
theorem mul_polyOfInterest_aux2 (n : ℕ) :
(p : 𝕄) ^ n * wittMul p n + wittPolyProdRemainder p n = wittPolyProd p n := by
convert mul_polyOfInterest_aux1 p n
rw [sum_range_succ, add_comm, Nat.sub_self, pow_zero, pow_one]
rfl
#align witt_vector.mul_poly_of_interest_aux2 WittVector.mul_polyOfInterest_aux2
theorem mul_polyOfInterest_aux3 (n : ℕ) : wittPolyProd p (n + 1) =
-((p : 𝕄) ^ (n + 1) * X (0, n + 1)) * ((p : 𝕄) ^ (n + 1) * X (1, n + 1)) +
(p : 𝕄) ^ (n + 1) * X (0, n + 1) * rename (Prod.mk (1 : Fin 2)) (wittPolynomial p ℤ (n + 1)) +
(p : 𝕄) ^ (n + 1) * X (1, n + 1) * rename (Prod.mk (0 : Fin 2)) (wittPolynomial p ℤ (n + 1)) +
remainder p n := by
-- a useful auxiliary fact
have mvpz : (p : 𝕄) ^ (n + 1) = MvPolynomial.C ((p : ℤ) ^ (n + 1)) := by norm_cast
-- Porting note: the original proof applies `sum_range_succ` through a non-`conv` rewrite,
-- but this does not work in Lean 4; the whole proof also times out very badly. The proof has been
-- nearly totally rewritten here and now finishes quite fast.
rw [wittPolyProd, wittPolynomial, AlgHom.map_sum, AlgHom.map_sum]
conv_lhs =>
arg 1
rw [sum_range_succ, ← C_mul_X_pow_eq_monomial, tsub_self, pow_zero, pow_one, map_mul,
rename_C, rename_X, ← mvpz]
conv_lhs =>
arg 2
rw [sum_range_succ, ← C_mul_X_pow_eq_monomial, tsub_self, pow_zero, pow_one, map_mul,
rename_C, rename_X, ← mvpz]
conv_rhs =>
enter [1, 1, 2, 2]
rw [sum_range_succ, ← C_mul_X_pow_eq_monomial, tsub_self, pow_zero, pow_one, map_mul,
rename_C, rename_X, ← mvpz]
conv_rhs =>
enter [1, 2, 2]
rw [sum_range_succ, ← C_mul_X_pow_eq_monomial, tsub_self, pow_zero, pow_one, map_mul,
rename_C, rename_X, ← mvpz]
simp only [add_mul, mul_add]
rw [add_comm _ (remainder p n)]
simp only [add_assoc]
apply congrArg (Add.add _)
ring
#align witt_vector.mul_poly_of_interest_aux3 WittVector.mul_polyOfInterest_aux3
theorem mul_polyOfInterest_aux4 (n : ℕ) :
(p : 𝕄) ^ (n + 1) * wittMul p (n + 1) =
-((p : 𝕄) ^ (n + 1) * X (0, n + 1)) * ((p : 𝕄) ^ (n + 1) * X (1, n + 1)) +
(p : 𝕄) ^ (n + 1) * X (0, n + 1) * rename (Prod.mk (1 : Fin 2)) (wittPolynomial p ℤ (n + 1)) +
(p : 𝕄) ^ (n + 1) * X (1, n + 1) * rename (Prod.mk (0 : Fin 2)) (wittPolynomial p ℤ (n + 1)) +
(remainder p n - wittPolyProdRemainder p (n + 1)) := by
rw [← add_sub_assoc, eq_sub_iff_add_eq, mul_polyOfInterest_aux2]
exact mul_polyOfInterest_aux3 _ _
#align witt_vector.mul_poly_of_interest_aux4 WittVector.mul_polyOfInterest_aux4
| Mathlib/RingTheory/WittVector/MulCoeff.lean | 189 | 193 | theorem mul_polyOfInterest_aux5 (n : ℕ) :
(p : 𝕄) ^ (n + 1) * polyOfInterest p n = remainder p n - wittPolyProdRemainder p (n + 1) := by |
simp only [polyOfInterest, mul_sub, mul_add, sub_eq_iff_eq_add']
rw [mul_polyOfInterest_aux4 p n]
ring
|
import Mathlib.Analysis.Complex.Circle
import Mathlib.MeasureTheory.Group.Integral
import Mathlib.MeasureTheory.Integral.SetIntegral
import Mathlib.MeasureTheory.Measure.Haar.OfBasis
import Mathlib.MeasureTheory.Constructions.Prod.Integral
import Mathlib.MeasureTheory.Measure.Haar.InnerProductSpace
import Mathlib.Algebra.Group.AddChar
#align_import analysis.fourier.fourier_transform from "leanprover-community/mathlib"@"fd5edc43dc4f10b85abfe544b88f82cf13c5f844"
noncomputable section
local notation "𝕊" => circle
open MeasureTheory Filter
open scoped Topology
namespace VectorFourier
variable {𝕜 : Type*} [CommRing 𝕜] {V : Type*} [AddCommGroup V] [Module 𝕜 V] [MeasurableSpace V]
{W : Type*} [AddCommGroup W] [Module 𝕜 W]
{E F G : Type*} [NormedAddCommGroup E] [NormedSpace ℂ E] [NormedAddCommGroup F] [NormedSpace ℂ F]
[NormedAddCommGroup G] [NormedSpace ℂ G]
section Defs
def fourierIntegral (e : AddChar 𝕜 𝕊) (μ : Measure V) (L : V →ₗ[𝕜] W →ₗ[𝕜] 𝕜) (f : V → E)
(w : W) : E :=
∫ v, e (-L v w) • f v ∂μ
#align vector_fourier.fourier_integral VectorFourier.fourierIntegral
| Mathlib/Analysis/Fourier/FourierTransform.lean | 84 | 92 | theorem fourierIntegral_smul_const (e : AddChar 𝕜 𝕊) (μ : Measure V)
(L : V →ₗ[𝕜] W →ₗ[𝕜] 𝕜) (f : V → E) (r : ℂ) :
fourierIntegral e μ L (r • f) = r • fourierIntegral e μ L f := by |
ext1 w
-- Porting note: was
-- simp only [Pi.smul_apply, fourierIntegral, smul_comm _ r, integral_smul]
simp only [Pi.smul_apply, fourierIntegral, ← integral_smul]
congr 1 with v
rw [smul_comm]
|
import Mathlib.MeasureTheory.Measure.Haar.Basic
import Mathlib.Analysis.InnerProductSpace.PiL2
#align_import measure_theory.measure.haar.of_basis from "leanprover-community/mathlib"@"92bd7b1ffeb306a89f450bee126ddd8a284c259d"
open Set TopologicalSpace MeasureTheory MeasureTheory.Measure FiniteDimensional
open scoped Pointwise
noncomputable section
variable {ι ι' E F : Type*}
section Fintype
variable [Fintype ι] [Fintype ι']
section AddCommGroup
variable [AddCommGroup E] [Module ℝ E] [AddCommGroup F] [Module ℝ F]
def parallelepiped (v : ι → E) : Set E :=
(fun t : ι → ℝ => ∑ i, t i • v i) '' Icc 0 1
#align parallelepiped parallelepiped
theorem mem_parallelepiped_iff (v : ι → E) (x : E) :
x ∈ parallelepiped v ↔ ∃ t ∈ Icc (0 : ι → ℝ) 1, x = ∑ i, t i • v i := by
simp [parallelepiped, eq_comm]
#align mem_parallelepiped_iff mem_parallelepiped_iff
theorem parallelepiped_basis_eq (b : Basis ι ℝ E) :
parallelepiped b = {x | ∀ i, b.repr x i ∈ Set.Icc 0 1} := by
classical
ext x
simp_rw [mem_parallelepiped_iff, mem_setOf_eq, b.ext_elem_iff, _root_.map_sum,
_root_.map_smul, Finset.sum_apply', Basis.repr_self, Finsupp.smul_single, smul_eq_mul,
mul_one, Finsupp.single_apply, Finset.sum_ite_eq', Finset.mem_univ, ite_true, mem_Icc,
Pi.le_def, Pi.zero_apply, Pi.one_apply, ← forall_and]
aesop
theorem image_parallelepiped (f : E →ₗ[ℝ] F) (v : ι → E) :
f '' parallelepiped v = parallelepiped (f ∘ v) := by
simp only [parallelepiped, ← image_comp]
congr 1 with t
simp only [Function.comp_apply, _root_.map_sum, LinearMap.map_smulₛₗ, RingHom.id_apply]
#align image_parallelepiped image_parallelepiped
@[simp]
theorem parallelepiped_comp_equiv (v : ι → E) (e : ι' ≃ ι) :
parallelepiped (v ∘ e) = parallelepiped v := by
simp only [parallelepiped]
let K : (ι' → ℝ) ≃ (ι → ℝ) := Equiv.piCongrLeft' (fun _a : ι' => ℝ) e
have : Icc (0 : ι → ℝ) 1 = K '' Icc (0 : ι' → ℝ) 1 := by
rw [← Equiv.preimage_eq_iff_eq_image]
ext x
simp only [K, mem_preimage, mem_Icc, Pi.le_def, Pi.zero_apply, Equiv.piCongrLeft'_apply,
Pi.one_apply]
refine
⟨fun h => ⟨fun i => ?_, fun i => ?_⟩, fun h =>
⟨fun i => h.1 (e.symm i), fun i => h.2 (e.symm i)⟩⟩
· simpa only [Equiv.symm_apply_apply] using h.1 (e i)
· simpa only [Equiv.symm_apply_apply] using h.2 (e i)
rw [this, ← image_comp]
congr 1 with x
have := fun z : ι' → ℝ => e.symm.sum_comp fun i => z i • v (e i)
simp_rw [Equiv.apply_symm_apply] at this
simp_rw [Function.comp_apply, mem_image, mem_Icc, K, Equiv.piCongrLeft'_apply, this]
#align parallelepiped_comp_equiv parallelepiped_comp_equiv
-- The parallelepiped associated to an orthonormal basis of `ℝ` is either `[0, 1]` or `[-1, 0]`.
theorem parallelepiped_orthonormalBasis_one_dim (b : OrthonormalBasis ι ℝ ℝ) :
parallelepiped b = Icc 0 1 ∨ parallelepiped b = Icc (-1) 0 := by
have e : ι ≃ Fin 1 := by
apply Fintype.equivFinOfCardEq
simp only [← finrank_eq_card_basis b.toBasis, finrank_self]
have B : parallelepiped (b.reindex e) = parallelepiped b := by
convert parallelepiped_comp_equiv b e.symm
ext i
simp only [OrthonormalBasis.coe_reindex]
rw [← B]
let F : ℝ → Fin 1 → ℝ := fun t => fun _i => t
have A : Icc (0 : Fin 1 → ℝ) 1 = F '' Icc (0 : ℝ) 1 := by
apply Subset.antisymm
· intro x hx
refine ⟨x 0, ⟨hx.1 0, hx.2 0⟩, ?_⟩
ext j
simp only [Subsingleton.elim j 0]
· rintro x ⟨y, hy, rfl⟩
exact ⟨fun _j => hy.1, fun _j => hy.2⟩
rcases orthonormalBasis_one_dim (b.reindex e) with (H | H)
· left
simp_rw [parallelepiped, H, A, Algebra.id.smul_eq_mul, mul_one]
simp only [Finset.univ_unique, Fin.default_eq_zero, smul_eq_mul, mul_one, Finset.sum_singleton,
← image_comp, Function.comp_apply, image_id', ge_iff_le, zero_le_one, not_true, gt_iff_lt]
· right
simp_rw [H, parallelepiped, Algebra.id.smul_eq_mul, A]
simp only [F, Finset.univ_unique, Fin.default_eq_zero, mul_neg, mul_one, Finset.sum_neg_distrib,
Finset.sum_singleton, ← image_comp, Function.comp, image_neg, preimage_neg_Icc, neg_zero]
#align parallelepiped_orthonormal_basis_one_dim parallelepiped_orthonormalBasis_one_dim
theorem parallelepiped_eq_sum_segment (v : ι → E) : parallelepiped v = ∑ i, segment ℝ 0 (v i) := by
ext
simp only [mem_parallelepiped_iff, Set.mem_finset_sum, Finset.mem_univ, forall_true_left,
segment_eq_image, smul_zero, zero_add, ← Set.pi_univ_Icc, Set.mem_univ_pi]
constructor
· rintro ⟨t, ht, rfl⟩
exact ⟨t • v, fun {i} => ⟨t i, ht _, by simp⟩, rfl⟩
rintro ⟨g, hg, rfl⟩
choose t ht hg using @hg
refine ⟨@t, @ht, ?_⟩
simp_rw [hg]
#align parallelepiped_eq_sum_segment parallelepiped_eq_sum_segment
theorem convex_parallelepiped (v : ι → E) : Convex ℝ (parallelepiped v) := by
rw [parallelepiped_eq_sum_segment]
exact convex_sum _ fun _i _hi => convex_segment _ _
#align convex_parallelepiped convex_parallelepiped
| Mathlib/MeasureTheory/Measure/Haar/OfBasis.lean | 147 | 149 | theorem parallelepiped_eq_convexHull (v : ι → E) :
parallelepiped v = convexHull ℝ (∑ i, {(0 : E), v i}) := by |
simp_rw [convexHull_sum, convexHull_pair, parallelepiped_eq_sum_segment]
|
import Mathlib.Order.Filter.Bases
import Mathlib.Topology.Algebra.Module.Basic
#align_import topology.algebra.filter_basis from "leanprover-community/mathlib"@"f2ce6086713c78a7f880485f7917ea547a215982"
open Filter Set TopologicalSpace Function
open Topology Filter Pointwise
universe u
class GroupFilterBasis (G : Type u) [Group G] extends FilterBasis G where
one' : ∀ {U}, U ∈ sets → (1 : G) ∈ U
mul' : ∀ {U}, U ∈ sets → ∃ V ∈ sets, V * V ⊆ U
inv' : ∀ {U}, U ∈ sets → ∃ V ∈ sets, V ⊆ (fun x ↦ x⁻¹) ⁻¹' U
conj' : ∀ x₀, ∀ {U}, U ∈ sets → ∃ V ∈ sets, V ⊆ (fun x ↦ x₀ * x * x₀⁻¹) ⁻¹' U
#align group_filter_basis GroupFilterBasis
class AddGroupFilterBasis (A : Type u) [AddGroup A] extends FilterBasis A where
zero' : ∀ {U}, U ∈ sets → (0 : A) ∈ U
add' : ∀ {U}, U ∈ sets → ∃ V ∈ sets, V + V ⊆ U
neg' : ∀ {U}, U ∈ sets → ∃ V ∈ sets, V ⊆ (fun x ↦ -x) ⁻¹' U
conj' : ∀ x₀, ∀ {U}, U ∈ sets → ∃ V ∈ sets, V ⊆ (fun x ↦ x₀ + x + -x₀) ⁻¹' U
#align add_group_filter_basis AddGroupFilterBasis
attribute [to_additive existing] GroupFilterBasis GroupFilterBasis.conj'
GroupFilterBasis.toFilterBasis
@[to_additive "`AddGroupFilterBasis` constructor in the additive commutative group case."]
def groupFilterBasisOfComm {G : Type*} [CommGroup G] (sets : Set (Set G))
(nonempty : sets.Nonempty) (inter_sets : ∀ x y, x ∈ sets → y ∈ sets → ∃ z ∈ sets, z ⊆ x ∩ y)
(one : ∀ U ∈ sets, (1 : G) ∈ U) (mul : ∀ U ∈ sets, ∃ V ∈ sets, V * V ⊆ U)
(inv : ∀ U ∈ sets, ∃ V ∈ sets, V ⊆ (fun x ↦ x⁻¹) ⁻¹' U) : GroupFilterBasis G :=
{ sets := sets
nonempty := nonempty
inter_sets := inter_sets _ _
one' := one _
mul' := mul _
inv' := inv _
conj' := fun x U U_in ↦ ⟨U, U_in, by simp only [mul_inv_cancel_comm, preimage_id']; rfl⟩ }
#align group_filter_basis_of_comm groupFilterBasisOfComm
#align add_group_filter_basis_of_comm addGroupFilterBasisOfComm
namespace GroupFilterBasis
variable {G : Type u} [Group G] {B : GroupFilterBasis G}
@[to_additive]
instance : Membership (Set G) (GroupFilterBasis G) :=
⟨fun s f ↦ s ∈ f.sets⟩
@[to_additive]
theorem one {U : Set G} : U ∈ B → (1 : G) ∈ U :=
GroupFilterBasis.one'
#align group_filter_basis.one GroupFilterBasis.one
#align add_group_filter_basis.zero AddGroupFilterBasis.zero
@[to_additive]
theorem mul {U : Set G} : U ∈ B → ∃ V ∈ B, V * V ⊆ U :=
GroupFilterBasis.mul'
#align group_filter_basis.mul GroupFilterBasis.mul
#align add_group_filter_basis.add AddGroupFilterBasis.add
@[to_additive]
theorem inv {U : Set G} : U ∈ B → ∃ V ∈ B, V ⊆ (fun x ↦ x⁻¹) ⁻¹' U :=
GroupFilterBasis.inv'
#align group_filter_basis.inv GroupFilterBasis.inv
#align add_group_filter_basis.neg AddGroupFilterBasis.neg
@[to_additive]
theorem conj : ∀ x₀, ∀ {U}, U ∈ B → ∃ V ∈ B, V ⊆ (fun x ↦ x₀ * x * x₀⁻¹) ⁻¹' U :=
GroupFilterBasis.conj'
#align group_filter_basis.conj GroupFilterBasis.conj
#align add_group_filter_basis.conj AddGroupFilterBasis.conj
@[to_additive "The trivial additive group filter basis consists of `{0}` only. The associated
topology is discrete."]
instance : Inhabited (GroupFilterBasis G) where
default := {
sets := {{1}}
nonempty := singleton_nonempty _
inter_sets := by simp
one' := by simp
mul' := by simp
inv' := by simp
conj' := by simp }
@[to_additive]
theorem subset_mul_self (B : GroupFilterBasis G) {U : Set G} (h : U ∈ B) : U ⊆ U * U :=
fun x x_in ↦ ⟨1, one h, x, x_in, one_mul x⟩
#align group_filter_basis.prod_subset_self GroupFilterBasis.subset_mul_self
#align add_group_filter_basis.sum_subset_self AddGroupFilterBasis.subset_add_self
@[to_additive "The neighborhood function of an `AddGroupFilterBasis`."]
def N (B : GroupFilterBasis G) : G → Filter G :=
fun x ↦ map (fun y ↦ x * y) B.toFilterBasis.filter
set_option linter.uppercaseLean3 false in
#align group_filter_basis.N GroupFilterBasis.N
set_option linter.uppercaseLean3 false in
#align add_group_filter_basis.N AddGroupFilterBasis.N
@[to_additive (attr := simp)]
theorem N_one (B : GroupFilterBasis G) : B.N 1 = B.toFilterBasis.filter := by
simp only [N, one_mul, map_id']
set_option linter.uppercaseLean3 false in
#align group_filter_basis.N_one GroupFilterBasis.N_one
set_option linter.uppercaseLean3 false in
#align add_group_filter_basis.N_zero AddGroupFilterBasis.N_zero
@[to_additive]
protected theorem hasBasis (B : GroupFilterBasis G) (x : G) :
HasBasis (B.N x) (fun V : Set G ↦ V ∈ B) fun V ↦ (fun y ↦ x * y) '' V :=
HasBasis.map (fun y ↦ x * y) toFilterBasis.hasBasis
#align group_filter_basis.has_basis GroupFilterBasis.hasBasis
#align add_group_filter_basis.has_basis AddGroupFilterBasis.hasBasis
@[to_additive "The topological space structure coming from an additive group filter basis."]
def topology (B : GroupFilterBasis G) : TopologicalSpace G :=
TopologicalSpace.mkOfNhds B.N
#align group_filter_basis.topology GroupFilterBasis.topology
#align add_group_filter_basis.topology AddGroupFilterBasis.topology
@[to_additive]
theorem nhds_eq (B : GroupFilterBasis G) {x₀ : G} : @nhds G B.topology x₀ = B.N x₀ := by
apply TopologicalSpace.nhds_mkOfNhds_of_hasBasis (fun x ↦ (FilterBasis.hasBasis _).map _)
· intro a U U_in
exact ⟨1, B.one U_in, mul_one a⟩
· intro a U U_in
rcases GroupFilterBasis.mul U_in with ⟨V, V_in, hVU⟩
filter_upwards [image_mem_map (B.mem_filter_of_mem V_in)]
rintro _ ⟨x, hx, rfl⟩
calc
a • U ⊇ a • (V * V) := smul_set_mono hVU
_ ⊇ a • x • V := smul_set_mono <| smul_set_subset_smul hx
_ = (a * x) • V := smul_smul ..
_ ∈ (a * x) • B.filter := smul_set_mem_smul_filter <| B.mem_filter_of_mem V_in
#align group_filter_basis.nhds_eq GroupFilterBasis.nhds_eq
#align add_group_filter_basis.nhds_eq AddGroupFilterBasis.nhds_eq
@[to_additive]
| Mathlib/Topology/Algebra/FilterBasis.lean | 188 | 192 | theorem nhds_one_eq (B : GroupFilterBasis G) :
@nhds G B.topology (1 : G) = B.toFilterBasis.filter := by |
rw [B.nhds_eq]
simp only [N, one_mul]
exact map_id
|
import Mathlib.Algebra.Polynomial.RingDivision
import Mathlib.RingTheory.Localization.FractionRing
#align_import data.polynomial.ring_division from "leanprover-community/mathlib"@"8efcf8022aac8e01df8d302dcebdbc25d6a886c8"
noncomputable section
namespace Polynomial
universe u v w z
variable {R : Type u} {S : Type v} {T : Type w} {a b : R} {n : ℕ}
section CommRing
variable [CommRing R] [IsDomain R] {p q : R[X]}
section Roots
open Multiset Finset
noncomputable def roots (p : R[X]) : Multiset R :=
haveI := Classical.decEq R
haveI := Classical.dec (p = 0)
if h : p = 0 then ∅ else Classical.choose (exists_multiset_roots h)
#align polynomial.roots Polynomial.roots
theorem roots_def [DecidableEq R] (p : R[X]) [Decidable (p = 0)] :
p.roots = if h : p = 0 then ∅ else Classical.choose (exists_multiset_roots h) := by
-- porting noteL `‹_›` doesn't work for instance arguments
rename_i iR ip0
obtain rfl := Subsingleton.elim iR (Classical.decEq R)
obtain rfl := Subsingleton.elim ip0 (Classical.dec (p = 0))
rfl
#align polynomial.roots_def Polynomial.roots_def
@[simp]
theorem roots_zero : (0 : R[X]).roots = 0 :=
dif_pos rfl
#align polynomial.roots_zero Polynomial.roots_zero
theorem card_roots (hp0 : p ≠ 0) : (Multiset.card (roots p) : WithBot ℕ) ≤ degree p := by
classical
unfold roots
rw [dif_neg hp0]
exact (Classical.choose_spec (exists_multiset_roots hp0)).1
#align polynomial.card_roots Polynomial.card_roots
theorem card_roots' (p : R[X]) : Multiset.card p.roots ≤ natDegree p := by
by_cases hp0 : p = 0
· simp [hp0]
exact WithBot.coe_le_coe.1 (le_trans (card_roots hp0) (le_of_eq <| degree_eq_natDegree hp0))
#align polynomial.card_roots' Polynomial.card_roots'
theorem card_roots_sub_C {p : R[X]} {a : R} (hp0 : 0 < degree p) :
(Multiset.card (p - C a).roots : WithBot ℕ) ≤ degree p :=
calc
(Multiset.card (p - C a).roots : WithBot ℕ) ≤ degree (p - C a) :=
card_roots <| mt sub_eq_zero.1 fun h => not_le_of_gt hp0 <| h.symm ▸ degree_C_le
_ = degree p := by rw [sub_eq_add_neg, ← C_neg]; exact degree_add_C hp0
set_option linter.uppercaseLean3 false in
#align polynomial.card_roots_sub_C Polynomial.card_roots_sub_C
theorem card_roots_sub_C' {p : R[X]} {a : R} (hp0 : 0 < degree p) :
Multiset.card (p - C a).roots ≤ natDegree p :=
WithBot.coe_le_coe.1
(le_trans (card_roots_sub_C hp0)
(le_of_eq <| degree_eq_natDegree fun h => by simp_all [lt_irrefl]))
set_option linter.uppercaseLean3 false in
#align polynomial.card_roots_sub_C' Polynomial.card_roots_sub_C'
@[simp]
theorem count_roots [DecidableEq R] (p : R[X]) : p.roots.count a = rootMultiplicity a p := by
classical
by_cases hp : p = 0
· simp [hp]
rw [roots_def, dif_neg hp]
exact (Classical.choose_spec (exists_multiset_roots hp)).2 a
#align polynomial.count_roots Polynomial.count_roots
@[simp]
theorem mem_roots' : a ∈ p.roots ↔ p ≠ 0 ∧ IsRoot p a := by
classical
rw [← count_pos, count_roots p, rootMultiplicity_pos']
#align polynomial.mem_roots' Polynomial.mem_roots'
theorem mem_roots (hp : p ≠ 0) : a ∈ p.roots ↔ IsRoot p a :=
mem_roots'.trans <| and_iff_right hp
#align polynomial.mem_roots Polynomial.mem_roots
theorem ne_zero_of_mem_roots (h : a ∈ p.roots) : p ≠ 0 :=
(mem_roots'.1 h).1
#align polynomial.ne_zero_of_mem_roots Polynomial.ne_zero_of_mem_roots
theorem isRoot_of_mem_roots (h : a ∈ p.roots) : IsRoot p a :=
(mem_roots'.1 h).2
#align polynomial.is_root_of_mem_roots Polynomial.isRoot_of_mem_roots
-- Porting note: added during port.
lemma mem_roots_iff_aeval_eq_zero {x : R} (w : p ≠ 0) : x ∈ roots p ↔ aeval x p = 0 := by
rw [mem_roots w, IsRoot.def, aeval_def, eval₂_eq_eval_map]
simp
theorem card_le_degree_of_subset_roots {p : R[X]} {Z : Finset R} (h : Z.val ⊆ p.roots) :
Z.card ≤ p.natDegree :=
(Multiset.card_le_card (Finset.val_le_iff_val_subset.2 h)).trans (Polynomial.card_roots' p)
#align polynomial.card_le_degree_of_subset_roots Polynomial.card_le_degree_of_subset_roots
theorem finite_setOf_isRoot {p : R[X]} (hp : p ≠ 0) : Set.Finite { x | IsRoot p x } := by
classical
simpa only [← Finset.setOf_mem, Multiset.mem_toFinset, mem_roots hp]
using p.roots.toFinset.finite_toSet
#align polynomial.finite_set_of_is_root Polynomial.finite_setOf_isRoot
theorem eq_zero_of_infinite_isRoot (p : R[X]) (h : Set.Infinite { x | IsRoot p x }) : p = 0 :=
not_imp_comm.mp finite_setOf_isRoot h
#align polynomial.eq_zero_of_infinite_is_root Polynomial.eq_zero_of_infinite_isRoot
theorem exists_max_root [LinearOrder R] (p : R[X]) (hp : p ≠ 0) : ∃ x₀, ∀ x, p.IsRoot x → x ≤ x₀ :=
Set.exists_upper_bound_image _ _ <| finite_setOf_isRoot hp
#align polynomial.exists_max_root Polynomial.exists_max_root
theorem exists_min_root [LinearOrder R] (p : R[X]) (hp : p ≠ 0) : ∃ x₀, ∀ x, p.IsRoot x → x₀ ≤ x :=
Set.exists_lower_bound_image _ _ <| finite_setOf_isRoot hp
#align polynomial.exists_min_root Polynomial.exists_min_root
theorem eq_of_infinite_eval_eq (p q : R[X]) (h : Set.Infinite { x | eval x p = eval x q }) :
p = q := by
rw [← sub_eq_zero]
apply eq_zero_of_infinite_isRoot
simpa only [IsRoot, eval_sub, sub_eq_zero]
#align polynomial.eq_of_infinite_eval_eq Polynomial.eq_of_infinite_eval_eq
theorem roots_mul {p q : R[X]} (hpq : p * q ≠ 0) : (p * q).roots = p.roots + q.roots := by
classical
exact Multiset.ext.mpr fun r => by
rw [count_add, count_roots, count_roots, count_roots, rootMultiplicity_mul hpq]
#align polynomial.roots_mul Polynomial.roots_mul
theorem roots.le_of_dvd (h : q ≠ 0) : p ∣ q → roots p ≤ roots q := by
rintro ⟨k, rfl⟩
exact Multiset.le_iff_exists_add.mpr ⟨k.roots, roots_mul h⟩
#align polynomial.roots.le_of_dvd Polynomial.roots.le_of_dvd
theorem mem_roots_sub_C' {p : R[X]} {a x : R} : x ∈ (p - C a).roots ↔ p ≠ C a ∧ p.eval x = a := by
rw [mem_roots', IsRoot.def, sub_ne_zero, eval_sub, sub_eq_zero, eval_C]
set_option linter.uppercaseLean3 false in
#align polynomial.mem_roots_sub_C' Polynomial.mem_roots_sub_C'
theorem mem_roots_sub_C {p : R[X]} {a x : R} (hp0 : 0 < degree p) :
x ∈ (p - C a).roots ↔ p.eval x = a :=
mem_roots_sub_C'.trans <| and_iff_right fun hp => hp0.not_le <| hp.symm ▸ degree_C_le
set_option linter.uppercaseLean3 false in
#align polynomial.mem_roots_sub_C Polynomial.mem_roots_sub_C
@[simp]
theorem roots_X_sub_C (r : R) : roots (X - C r) = {r} := by
classical
ext s
rw [count_roots, rootMultiplicity_X_sub_C, count_singleton]
set_option linter.uppercaseLean3 false in
#align polynomial.roots_X_sub_C Polynomial.roots_X_sub_C
@[simp]
theorem roots_X : roots (X : R[X]) = {0} := by rw [← roots_X_sub_C, C_0, sub_zero]
set_option linter.uppercaseLean3 false in
#align polynomial.roots_X Polynomial.roots_X
@[simp]
theorem roots_C (x : R) : (C x).roots = 0 := by
classical exact
if H : x = 0 then by rw [H, C_0, roots_zero]
else
Multiset.ext.mpr fun r => (by
rw [count_roots, count_zero, rootMultiplicity_eq_zero (not_isRoot_C _ _ H)])
set_option linter.uppercaseLean3 false in
#align polynomial.roots_C Polynomial.roots_C
@[simp]
theorem roots_one : (1 : R[X]).roots = ∅ :=
roots_C 1
#align polynomial.roots_one Polynomial.roots_one
@[simp]
theorem roots_C_mul (p : R[X]) (ha : a ≠ 0) : (C a * p).roots = p.roots := by
by_cases hp : p = 0 <;>
simp only [roots_mul, *, Ne, mul_eq_zero, C_eq_zero, or_self_iff, not_false_iff, roots_C,
zero_add, mul_zero]
set_option linter.uppercaseLean3 false in
#align polynomial.roots_C_mul Polynomial.roots_C_mul
@[simp]
theorem roots_smul_nonzero (p : R[X]) (ha : a ≠ 0) : (a • p).roots = p.roots := by
rw [smul_eq_C_mul, roots_C_mul _ ha]
#align polynomial.roots_smul_nonzero Polynomial.roots_smul_nonzero
@[simp]
lemma roots_neg (p : R[X]) : (-p).roots = p.roots := by
rw [← neg_one_smul R p, roots_smul_nonzero p (neg_ne_zero.mpr one_ne_zero)]
theorem roots_list_prod (L : List R[X]) :
(0 : R[X]) ∉ L → L.prod.roots = (L : Multiset R[X]).bind roots :=
List.recOn L (fun _ => roots_one) fun hd tl ih H => by
rw [List.mem_cons, not_or] at H
rw [List.prod_cons, roots_mul (mul_ne_zero (Ne.symm H.1) <| List.prod_ne_zero H.2), ←
Multiset.cons_coe, Multiset.cons_bind, ih H.2]
#align polynomial.roots_list_prod Polynomial.roots_list_prod
theorem roots_multiset_prod (m : Multiset R[X]) : (0 : R[X]) ∉ m → m.prod.roots = m.bind roots := by
rcases m with ⟨L⟩
simpa only [Multiset.prod_coe, quot_mk_to_coe''] using roots_list_prod L
#align polynomial.roots_multiset_prod Polynomial.roots_multiset_prod
| Mathlib/Algebra/Polynomial/Roots.lean | 241 | 244 | theorem roots_prod {ι : Type*} (f : ι → R[X]) (s : Finset ι) :
s.prod f ≠ 0 → (s.prod f).roots = s.val.bind fun i => roots (f i) := by |
rcases s with ⟨m, hm⟩
simpa [Multiset.prod_eq_zero_iff, Multiset.bind_map] using roots_multiset_prod (m.map f)
|
import Mathlib.Data.Fintype.Option
import Mathlib.Data.Fintype.Prod
import Mathlib.Data.Fintype.Pi
import Mathlib.Data.Vector.Basic
import Mathlib.Data.PFun
import Mathlib.Logic.Function.Iterate
import Mathlib.Order.Basic
import Mathlib.Tactic.ApplyFun
#align_import computability.turing_machine from "leanprover-community/mathlib"@"4c19a16e4b705bf135cf9a80ac18fcc99c438514"
assert_not_exists MonoidWithZero
open Relation
open Nat (iterate)
open Function (update iterate_succ iterate_succ_apply iterate_succ' iterate_succ_apply'
iterate_zero_apply)
namespace Turing
def BlankExtends {Γ} [Inhabited Γ] (l₁ l₂ : List Γ) : Prop :=
∃ n, l₂ = l₁ ++ List.replicate n default
#align turing.blank_extends Turing.BlankExtends
@[refl]
theorem BlankExtends.refl {Γ} [Inhabited Γ] (l : List Γ) : BlankExtends l l :=
⟨0, by simp⟩
#align turing.blank_extends.refl Turing.BlankExtends.refl
@[trans]
theorem BlankExtends.trans {Γ} [Inhabited Γ] {l₁ l₂ l₃ : List Γ} :
BlankExtends l₁ l₂ → BlankExtends l₂ l₃ → BlankExtends l₁ l₃ := by
rintro ⟨i, rfl⟩ ⟨j, rfl⟩
exact ⟨i + j, by simp [List.replicate_add]⟩
#align turing.blank_extends.trans Turing.BlankExtends.trans
theorem BlankExtends.below_of_le {Γ} [Inhabited Γ] {l l₁ l₂ : List Γ} :
BlankExtends l l₁ → BlankExtends l l₂ → l₁.length ≤ l₂.length → BlankExtends l₁ l₂ := by
rintro ⟨i, rfl⟩ ⟨j, rfl⟩ h; use j - i
simp only [List.length_append, Nat.add_le_add_iff_left, List.length_replicate] at h
simp only [← List.replicate_add, Nat.add_sub_cancel' h, List.append_assoc]
#align turing.blank_extends.below_of_le Turing.BlankExtends.below_of_le
def BlankExtends.above {Γ} [Inhabited Γ] {l l₁ l₂ : List Γ} (h₁ : BlankExtends l l₁)
(h₂ : BlankExtends l l₂) : { l' // BlankExtends l₁ l' ∧ BlankExtends l₂ l' } :=
if h : l₁.length ≤ l₂.length then ⟨l₂, h₁.below_of_le h₂ h, BlankExtends.refl _⟩
else ⟨l₁, BlankExtends.refl _, h₂.below_of_le h₁ (le_of_not_ge h)⟩
#align turing.blank_extends.above Turing.BlankExtends.above
theorem BlankExtends.above_of_le {Γ} [Inhabited Γ] {l l₁ l₂ : List Γ} :
BlankExtends l₁ l → BlankExtends l₂ l → l₁.length ≤ l₂.length → BlankExtends l₁ l₂ := by
rintro ⟨i, rfl⟩ ⟨j, e⟩ h; use i - j
refine List.append_cancel_right (e.symm.trans ?_)
rw [List.append_assoc, ← List.replicate_add, Nat.sub_add_cancel]
apply_fun List.length at e
simp only [List.length_append, List.length_replicate] at e
rwa [← Nat.add_le_add_iff_left, e, Nat.add_le_add_iff_right]
#align turing.blank_extends.above_of_le Turing.BlankExtends.above_of_le
def BlankRel {Γ} [Inhabited Γ] (l₁ l₂ : List Γ) : Prop :=
BlankExtends l₁ l₂ ∨ BlankExtends l₂ l₁
#align turing.blank_rel Turing.BlankRel
@[refl]
theorem BlankRel.refl {Γ} [Inhabited Γ] (l : List Γ) : BlankRel l l :=
Or.inl (BlankExtends.refl _)
#align turing.blank_rel.refl Turing.BlankRel.refl
@[symm]
theorem BlankRel.symm {Γ} [Inhabited Γ] {l₁ l₂ : List Γ} : BlankRel l₁ l₂ → BlankRel l₂ l₁ :=
Or.symm
#align turing.blank_rel.symm Turing.BlankRel.symm
@[trans]
theorem BlankRel.trans {Γ} [Inhabited Γ] {l₁ l₂ l₃ : List Γ} :
BlankRel l₁ l₂ → BlankRel l₂ l₃ → BlankRel l₁ l₃ := by
rintro (h₁ | h₁) (h₂ | h₂)
· exact Or.inl (h₁.trans h₂)
· rcases le_total l₁.length l₃.length with h | h
· exact Or.inl (h₁.above_of_le h₂ h)
· exact Or.inr (h₂.above_of_le h₁ h)
· rcases le_total l₁.length l₃.length with h | h
· exact Or.inl (h₁.below_of_le h₂ h)
· exact Or.inr (h₂.below_of_le h₁ h)
· exact Or.inr (h₂.trans h₁)
#align turing.blank_rel.trans Turing.BlankRel.trans
def BlankRel.above {Γ} [Inhabited Γ] {l₁ l₂ : List Γ} (h : BlankRel l₁ l₂) :
{ l // BlankExtends l₁ l ∧ BlankExtends l₂ l } := by
refine
if hl : l₁.length ≤ l₂.length then ⟨l₂, Or.elim h id fun h' ↦ ?_, BlankExtends.refl _⟩
else ⟨l₁, BlankExtends.refl _, Or.elim h (fun h' ↦ ?_) id⟩
· exact (BlankExtends.refl _).above_of_le h' hl
· exact (BlankExtends.refl _).above_of_le h' (le_of_not_ge hl)
#align turing.blank_rel.above Turing.BlankRel.above
def BlankRel.below {Γ} [Inhabited Γ] {l₁ l₂ : List Γ} (h : BlankRel l₁ l₂) :
{ l // BlankExtends l l₁ ∧ BlankExtends l l₂ } := by
refine
if hl : l₁.length ≤ l₂.length then ⟨l₁, BlankExtends.refl _, Or.elim h id fun h' ↦ ?_⟩
else ⟨l₂, Or.elim h (fun h' ↦ ?_) id, BlankExtends.refl _⟩
· exact (BlankExtends.refl _).above_of_le h' hl
· exact (BlankExtends.refl _).above_of_le h' (le_of_not_ge hl)
#align turing.blank_rel.below Turing.BlankRel.below
theorem BlankRel.equivalence (Γ) [Inhabited Γ] : Equivalence (@BlankRel Γ _) :=
⟨BlankRel.refl, @BlankRel.symm _ _, @BlankRel.trans _ _⟩
#align turing.blank_rel.equivalence Turing.BlankRel.equivalence
def BlankRel.setoid (Γ) [Inhabited Γ] : Setoid (List Γ) :=
⟨_, BlankRel.equivalence _⟩
#align turing.blank_rel.setoid Turing.BlankRel.setoid
def ListBlank (Γ) [Inhabited Γ] :=
Quotient (BlankRel.setoid Γ)
#align turing.list_blank Turing.ListBlank
instance ListBlank.inhabited {Γ} [Inhabited Γ] : Inhabited (ListBlank Γ) :=
⟨Quotient.mk'' []⟩
#align turing.list_blank.inhabited Turing.ListBlank.inhabited
instance ListBlank.hasEmptyc {Γ} [Inhabited Γ] : EmptyCollection (ListBlank Γ) :=
⟨Quotient.mk'' []⟩
#align turing.list_blank.has_emptyc Turing.ListBlank.hasEmptyc
-- Porting note: Removed `@[elab_as_elim]`
protected abbrev ListBlank.liftOn {Γ} [Inhabited Γ] {α} (l : ListBlank Γ) (f : List Γ → α)
(H : ∀ a b, BlankExtends a b → f a = f b) : α :=
l.liftOn' f <| by rintro a b (h | h) <;> [exact H _ _ h; exact (H _ _ h).symm]
#align turing.list_blank.lift_on Turing.ListBlank.liftOn
def ListBlank.mk {Γ} [Inhabited Γ] : List Γ → ListBlank Γ :=
Quotient.mk''
#align turing.list_blank.mk Turing.ListBlank.mk
@[elab_as_elim]
protected theorem ListBlank.induction_on {Γ} [Inhabited Γ] {p : ListBlank Γ → Prop}
(q : ListBlank Γ) (h : ∀ a, p (ListBlank.mk a)) : p q :=
Quotient.inductionOn' q h
#align turing.list_blank.induction_on Turing.ListBlank.induction_on
def ListBlank.head {Γ} [Inhabited Γ] (l : ListBlank Γ) : Γ := by
apply l.liftOn List.headI
rintro a _ ⟨i, rfl⟩
cases a
· cases i <;> rfl
rfl
#align turing.list_blank.head Turing.ListBlank.head
@[simp]
theorem ListBlank.head_mk {Γ} [Inhabited Γ] (l : List Γ) :
ListBlank.head (ListBlank.mk l) = l.headI :=
rfl
#align turing.list_blank.head_mk Turing.ListBlank.head_mk
def ListBlank.tail {Γ} [Inhabited Γ] (l : ListBlank Γ) : ListBlank Γ := by
apply l.liftOn (fun l ↦ ListBlank.mk l.tail)
rintro a _ ⟨i, rfl⟩
refine Quotient.sound' (Or.inl ?_)
cases a
· cases' i with i <;> [exact ⟨0, rfl⟩; exact ⟨i, rfl⟩]
exact ⟨i, rfl⟩
#align turing.list_blank.tail Turing.ListBlank.tail
@[simp]
theorem ListBlank.tail_mk {Γ} [Inhabited Γ] (l : List Γ) :
ListBlank.tail (ListBlank.mk l) = ListBlank.mk l.tail :=
rfl
#align turing.list_blank.tail_mk Turing.ListBlank.tail_mk
def ListBlank.cons {Γ} [Inhabited Γ] (a : Γ) (l : ListBlank Γ) : ListBlank Γ := by
apply l.liftOn (fun l ↦ ListBlank.mk (List.cons a l))
rintro _ _ ⟨i, rfl⟩
exact Quotient.sound' (Or.inl ⟨i, rfl⟩)
#align turing.list_blank.cons Turing.ListBlank.cons
@[simp]
theorem ListBlank.cons_mk {Γ} [Inhabited Γ] (a : Γ) (l : List Γ) :
ListBlank.cons a (ListBlank.mk l) = ListBlank.mk (a :: l) :=
rfl
#align turing.list_blank.cons_mk Turing.ListBlank.cons_mk
@[simp]
theorem ListBlank.head_cons {Γ} [Inhabited Γ] (a : Γ) : ∀ l : ListBlank Γ, (l.cons a).head = a :=
Quotient.ind' fun _ ↦ rfl
#align turing.list_blank.head_cons Turing.ListBlank.head_cons
@[simp]
theorem ListBlank.tail_cons {Γ} [Inhabited Γ] (a : Γ) : ∀ l : ListBlank Γ, (l.cons a).tail = l :=
Quotient.ind' fun _ ↦ rfl
#align turing.list_blank.tail_cons Turing.ListBlank.tail_cons
@[simp]
theorem ListBlank.cons_head_tail {Γ} [Inhabited Γ] : ∀ l : ListBlank Γ, l.tail.cons l.head = l := by
apply Quotient.ind'
refine fun l ↦ Quotient.sound' (Or.inr ?_)
cases l
· exact ⟨1, rfl⟩
· rfl
#align turing.list_blank.cons_head_tail Turing.ListBlank.cons_head_tail
theorem ListBlank.exists_cons {Γ} [Inhabited Γ] (l : ListBlank Γ) :
∃ a l', l = ListBlank.cons a l' :=
⟨_, _, (ListBlank.cons_head_tail _).symm⟩
#align turing.list_blank.exists_cons Turing.ListBlank.exists_cons
def ListBlank.nth {Γ} [Inhabited Γ] (l : ListBlank Γ) (n : ℕ) : Γ := by
apply l.liftOn (fun l ↦ List.getI l n)
rintro l _ ⟨i, rfl⟩
cases' lt_or_le n _ with h h
· rw [List.getI_append _ _ _ h]
rw [List.getI_eq_default _ h]
rcases le_or_lt _ n with h₂ | h₂
· rw [List.getI_eq_default _ h₂]
rw [List.getI_eq_get _ h₂, List.get_append_right' h, List.get_replicate]
#align turing.list_blank.nth Turing.ListBlank.nth
@[simp]
theorem ListBlank.nth_mk {Γ} [Inhabited Γ] (l : List Γ) (n : ℕ) :
(ListBlank.mk l).nth n = l.getI n :=
rfl
#align turing.list_blank.nth_mk Turing.ListBlank.nth_mk
@[simp]
theorem ListBlank.nth_zero {Γ} [Inhabited Γ] (l : ListBlank Γ) : l.nth 0 = l.head := by
conv => lhs; rw [← ListBlank.cons_head_tail l]
exact Quotient.inductionOn' l.tail fun l ↦ rfl
#align turing.list_blank.nth_zero Turing.ListBlank.nth_zero
@[simp]
theorem ListBlank.nth_succ {Γ} [Inhabited Γ] (l : ListBlank Γ) (n : ℕ) :
l.nth (n + 1) = l.tail.nth n := by
conv => lhs; rw [← ListBlank.cons_head_tail l]
exact Quotient.inductionOn' l.tail fun l ↦ rfl
#align turing.list_blank.nth_succ Turing.ListBlank.nth_succ
@[ext]
theorem ListBlank.ext {Γ} [i : Inhabited Γ] {L₁ L₂ : ListBlank Γ} :
(∀ i, L₁.nth i = L₂.nth i) → L₁ = L₂ := by
refine ListBlank.induction_on L₁ fun l₁ ↦ ListBlank.induction_on L₂ fun l₂ H ↦ ?_
wlog h : l₁.length ≤ l₂.length
· cases le_total l₁.length l₂.length <;> [skip; symm] <;> apply this <;> try assumption
intro
rw [H]
refine Quotient.sound' (Or.inl ⟨l₂.length - l₁.length, ?_⟩)
refine List.ext_get ?_ fun i h h₂ ↦ Eq.symm ?_
· simp only [Nat.add_sub_cancel' h, List.length_append, List.length_replicate]
simp only [ListBlank.nth_mk] at H
cases' lt_or_le i l₁.length with h' h'
· simp only [List.get_append _ h', List.get?_eq_get h, List.get?_eq_get h',
← List.getI_eq_get _ h, ← List.getI_eq_get _ h', H]
· simp only [List.get_append_right' h', List.get_replicate, List.get?_eq_get h,
List.get?_len_le h', ← List.getI_eq_default _ h', H, List.getI_eq_get _ h]
#align turing.list_blank.ext Turing.ListBlank.ext
@[simp]
def ListBlank.modifyNth {Γ} [Inhabited Γ] (f : Γ → Γ) : ℕ → ListBlank Γ → ListBlank Γ
| 0, L => L.tail.cons (f L.head)
| n + 1, L => (L.tail.modifyNth f n).cons L.head
#align turing.list_blank.modify_nth Turing.ListBlank.modifyNth
theorem ListBlank.nth_modifyNth {Γ} [Inhabited Γ] (f : Γ → Γ) (n i) (L : ListBlank Γ) :
(L.modifyNth f n).nth i = if i = n then f (L.nth i) else L.nth i := by
induction' n with n IH generalizing i L
· cases i <;> simp only [ListBlank.nth_zero, if_true, ListBlank.head_cons, ListBlank.modifyNth,
ListBlank.nth_succ, if_false, ListBlank.tail_cons, Nat.zero_eq]
· cases i
· rw [if_neg (Nat.succ_ne_zero _).symm]
simp only [ListBlank.nth_zero, ListBlank.head_cons, ListBlank.modifyNth, Nat.zero_eq]
· simp only [IH, ListBlank.modifyNth, ListBlank.nth_succ, ListBlank.tail_cons, Nat.succ.injEq]
#align turing.list_blank.nth_modify_nth Turing.ListBlank.nth_modifyNth
structure PointedMap.{u, v} (Γ : Type u) (Γ' : Type v) [Inhabited Γ] [Inhabited Γ'] :
Type max u v where
f : Γ → Γ'
map_pt' : f default = default
#align turing.pointed_map Turing.PointedMap
instance {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] : Inhabited (PointedMap Γ Γ') :=
⟨⟨default, rfl⟩⟩
instance {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] : CoeFun (PointedMap Γ Γ') fun _ ↦ Γ → Γ' :=
⟨PointedMap.f⟩
-- @[simp] -- Porting note (#10685): dsimp can prove this
theorem PointedMap.mk_val {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] (f : Γ → Γ') (pt) :
(PointedMap.mk f pt : Γ → Γ') = f :=
rfl
#align turing.pointed_map.mk_val Turing.PointedMap.mk_val
@[simp]
theorem PointedMap.map_pt {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] (f : PointedMap Γ Γ') :
f default = default :=
PointedMap.map_pt' _
#align turing.pointed_map.map_pt Turing.PointedMap.map_pt
@[simp]
theorem PointedMap.headI_map {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] (f : PointedMap Γ Γ')
(l : List Γ) : (l.map f).headI = f l.headI := by
cases l <;> [exact (PointedMap.map_pt f).symm; rfl]
#align turing.pointed_map.head_map Turing.PointedMap.headI_map
def ListBlank.map {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] (f : PointedMap Γ Γ') (l : ListBlank Γ) :
ListBlank Γ' := by
apply l.liftOn (fun l ↦ ListBlank.mk (List.map f l))
rintro l _ ⟨i, rfl⟩; refine Quotient.sound' (Or.inl ⟨i, ?_⟩)
simp only [PointedMap.map_pt, List.map_append, List.map_replicate]
#align turing.list_blank.map Turing.ListBlank.map
@[simp]
theorem ListBlank.map_mk {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] (f : PointedMap Γ Γ') (l : List Γ) :
(ListBlank.mk l).map f = ListBlank.mk (l.map f) :=
rfl
#align turing.list_blank.map_mk Turing.ListBlank.map_mk
@[simp]
theorem ListBlank.head_map {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] (f : PointedMap Γ Γ')
(l : ListBlank Γ) : (l.map f).head = f l.head := by
conv => lhs; rw [← ListBlank.cons_head_tail l]
exact Quotient.inductionOn' l fun a ↦ rfl
#align turing.list_blank.head_map Turing.ListBlank.head_map
@[simp]
theorem ListBlank.tail_map {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] (f : PointedMap Γ Γ')
(l : ListBlank Γ) : (l.map f).tail = l.tail.map f := by
conv => lhs; rw [← ListBlank.cons_head_tail l]
exact Quotient.inductionOn' l fun a ↦ rfl
#align turing.list_blank.tail_map Turing.ListBlank.tail_map
@[simp]
theorem ListBlank.map_cons {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] (f : PointedMap Γ Γ')
(l : ListBlank Γ) (a : Γ) : (l.cons a).map f = (l.map f).cons (f a) := by
refine (ListBlank.cons_head_tail _).symm.trans ?_
simp only [ListBlank.head_map, ListBlank.head_cons, ListBlank.tail_map, ListBlank.tail_cons]
#align turing.list_blank.map_cons Turing.ListBlank.map_cons
@[simp]
theorem ListBlank.nth_map {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] (f : PointedMap Γ Γ')
(l : ListBlank Γ) (n : ℕ) : (l.map f).nth n = f (l.nth n) := by
refine l.inductionOn fun l ↦ ?_
-- Porting note: Added `suffices` to get `simp` to work.
suffices ((mk l).map f).nth n = f ((mk l).nth n) by exact this
simp only [List.get?_map, ListBlank.map_mk, ListBlank.nth_mk, List.getI_eq_iget_get?]
cases l.get? n
· exact f.2.symm
· rfl
#align turing.list_blank.nth_map Turing.ListBlank.nth_map
def proj {ι : Type*} {Γ : ι → Type*} [∀ i, Inhabited (Γ i)] (i : ι) :
PointedMap (∀ i, Γ i) (Γ i) :=
⟨fun a ↦ a i, rfl⟩
#align turing.proj Turing.proj
theorem proj_map_nth {ι : Type*} {Γ : ι → Type*} [∀ i, Inhabited (Γ i)] (i : ι) (L n) :
(ListBlank.map (@proj ι Γ _ i) L).nth n = L.nth n i := by
rw [ListBlank.nth_map]; rfl
#align turing.proj_map_nth Turing.proj_map_nth
theorem ListBlank.map_modifyNth {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] (F : PointedMap Γ Γ')
(f : Γ → Γ) (f' : Γ' → Γ') (H : ∀ x, F (f x) = f' (F x)) (n) (L : ListBlank Γ) :
(L.modifyNth f n).map F = (L.map F).modifyNth f' n := by
induction' n with n IH generalizing L <;>
simp only [*, ListBlank.head_map, ListBlank.modifyNth, ListBlank.map_cons, ListBlank.tail_map]
#align turing.list_blank.map_modify_nth Turing.ListBlank.map_modifyNth
@[simp]
def ListBlank.append {Γ} [Inhabited Γ] : List Γ → ListBlank Γ → ListBlank Γ
| [], L => L
| a :: l, L => ListBlank.cons a (ListBlank.append l L)
#align turing.list_blank.append Turing.ListBlank.append
@[simp]
theorem ListBlank.append_mk {Γ} [Inhabited Γ] (l₁ l₂ : List Γ) :
ListBlank.append l₁ (ListBlank.mk l₂) = ListBlank.mk (l₁ ++ l₂) := by
induction l₁ <;>
simp only [*, ListBlank.append, List.nil_append, List.cons_append, ListBlank.cons_mk]
#align turing.list_blank.append_mk Turing.ListBlank.append_mk
theorem ListBlank.append_assoc {Γ} [Inhabited Γ] (l₁ l₂ : List Γ) (l₃ : ListBlank Γ) :
ListBlank.append (l₁ ++ l₂) l₃ = ListBlank.append l₁ (ListBlank.append l₂ l₃) := by
refine l₃.inductionOn fun l ↦ ?_
-- Porting note: Added `suffices` to get `simp` to work.
suffices append (l₁ ++ l₂) (mk l) = append l₁ (append l₂ (mk l)) by exact this
simp only [ListBlank.append_mk, List.append_assoc]
#align turing.list_blank.append_assoc Turing.ListBlank.append_assoc
def ListBlank.bind {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] (l : ListBlank Γ) (f : Γ → List Γ')
(hf : ∃ n, f default = List.replicate n default) : ListBlank Γ' := by
apply l.liftOn (fun l ↦ ListBlank.mk (List.bind l f))
rintro l _ ⟨i, rfl⟩; cases' hf with n e; refine Quotient.sound' (Or.inl ⟨i * n, ?_⟩)
rw [List.append_bind, mul_comm]; congr
induction' i with i IH
· rfl
simp only [IH, e, List.replicate_add, Nat.mul_succ, add_comm, List.replicate_succ, List.cons_bind]
#align turing.list_blank.bind Turing.ListBlank.bind
@[simp]
theorem ListBlank.bind_mk {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] (l : List Γ) (f : Γ → List Γ') (hf) :
(ListBlank.mk l).bind f hf = ListBlank.mk (l.bind f) :=
rfl
#align turing.list_blank.bind_mk Turing.ListBlank.bind_mk
@[simp]
theorem ListBlank.cons_bind {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] (a : Γ) (l : ListBlank Γ)
(f : Γ → List Γ') (hf) : (l.cons a).bind f hf = (l.bind f hf).append (f a) := by
refine l.inductionOn fun l ↦ ?_
-- Porting note: Added `suffices` to get `simp` to work.
suffices ((mk l).cons a).bind f hf = ((mk l).bind f hf).append (f a) by exact this
simp only [ListBlank.append_mk, ListBlank.bind_mk, ListBlank.cons_mk, List.cons_bind]
#align turing.list_blank.cons_bind Turing.ListBlank.cons_bind
structure Tape (Γ : Type*) [Inhabited Γ] where
head : Γ
left : ListBlank Γ
right : ListBlank Γ
#align turing.tape Turing.Tape
instance Tape.inhabited {Γ} [Inhabited Γ] : Inhabited (Tape Γ) :=
⟨by constructor <;> apply default⟩
#align turing.tape.inhabited Turing.Tape.inhabited
inductive Dir
| left
| right
deriving DecidableEq, Inhabited
#align turing.dir Turing.Dir
def Tape.left₀ {Γ} [Inhabited Γ] (T : Tape Γ) : ListBlank Γ :=
T.left.cons T.head
#align turing.tape.left₀ Turing.Tape.left₀
def Tape.right₀ {Γ} [Inhabited Γ] (T : Tape Γ) : ListBlank Γ :=
T.right.cons T.head
#align turing.tape.right₀ Turing.Tape.right₀
def Tape.move {Γ} [Inhabited Γ] : Dir → Tape Γ → Tape Γ
| Dir.left, ⟨a, L, R⟩ => ⟨L.head, L.tail, R.cons a⟩
| Dir.right, ⟨a, L, R⟩ => ⟨R.head, L.cons a, R.tail⟩
#align turing.tape.move Turing.Tape.move
@[simp]
theorem Tape.move_left_right {Γ} [Inhabited Γ] (T : Tape Γ) :
(T.move Dir.left).move Dir.right = T := by
cases T; simp [Tape.move]
#align turing.tape.move_left_right Turing.Tape.move_left_right
@[simp]
theorem Tape.move_right_left {Γ} [Inhabited Γ] (T : Tape Γ) :
(T.move Dir.right).move Dir.left = T := by
cases T; simp [Tape.move]
#align turing.tape.move_right_left Turing.Tape.move_right_left
def Tape.mk' {Γ} [Inhabited Γ] (L R : ListBlank Γ) : Tape Γ :=
⟨R.head, L, R.tail⟩
#align turing.tape.mk' Turing.Tape.mk'
@[simp]
theorem Tape.mk'_left {Γ} [Inhabited Γ] (L R : ListBlank Γ) : (Tape.mk' L R).left = L :=
rfl
#align turing.tape.mk'_left Turing.Tape.mk'_left
@[simp]
theorem Tape.mk'_head {Γ} [Inhabited Γ] (L R : ListBlank Γ) : (Tape.mk' L R).head = R.head :=
rfl
#align turing.tape.mk'_head Turing.Tape.mk'_head
@[simp]
theorem Tape.mk'_right {Γ} [Inhabited Γ] (L R : ListBlank Γ) : (Tape.mk' L R).right = R.tail :=
rfl
#align turing.tape.mk'_right Turing.Tape.mk'_right
@[simp]
theorem Tape.mk'_right₀ {Γ} [Inhabited Γ] (L R : ListBlank Γ) : (Tape.mk' L R).right₀ = R :=
ListBlank.cons_head_tail _
#align turing.tape.mk'_right₀ Turing.Tape.mk'_right₀
@[simp]
theorem Tape.mk'_left_right₀ {Γ} [Inhabited Γ] (T : Tape Γ) : Tape.mk' T.left T.right₀ = T := by
cases T
simp only [Tape.right₀, Tape.mk', ListBlank.head_cons, ListBlank.tail_cons, eq_self_iff_true,
and_self_iff]
#align turing.tape.mk'_left_right₀ Turing.Tape.mk'_left_right₀
theorem Tape.exists_mk' {Γ} [Inhabited Γ] (T : Tape Γ) : ∃ L R, T = Tape.mk' L R :=
⟨_, _, (Tape.mk'_left_right₀ _).symm⟩
#align turing.tape.exists_mk' Turing.Tape.exists_mk'
@[simp]
theorem Tape.move_left_mk' {Γ} [Inhabited Γ] (L R : ListBlank Γ) :
(Tape.mk' L R).move Dir.left = Tape.mk' L.tail (R.cons L.head) := by
simp only [Tape.move, Tape.mk', ListBlank.head_cons, eq_self_iff_true, ListBlank.cons_head_tail,
and_self_iff, ListBlank.tail_cons]
#align turing.tape.move_left_mk' Turing.Tape.move_left_mk'
@[simp]
theorem Tape.move_right_mk' {Γ} [Inhabited Γ] (L R : ListBlank Γ) :
(Tape.mk' L R).move Dir.right = Tape.mk' (L.cons R.head) R.tail := by
simp only [Tape.move, Tape.mk', ListBlank.head_cons, eq_self_iff_true, ListBlank.cons_head_tail,
and_self_iff, ListBlank.tail_cons]
#align turing.tape.move_right_mk' Turing.Tape.move_right_mk'
def Tape.mk₂ {Γ} [Inhabited Γ] (L R : List Γ) : Tape Γ :=
Tape.mk' (ListBlank.mk L) (ListBlank.mk R)
#align turing.tape.mk₂ Turing.Tape.mk₂
def Tape.mk₁ {Γ} [Inhabited Γ] (l : List Γ) : Tape Γ :=
Tape.mk₂ [] l
#align turing.tape.mk₁ Turing.Tape.mk₁
def Tape.nth {Γ} [Inhabited Γ] (T : Tape Γ) : ℤ → Γ
| 0 => T.head
| (n + 1 : ℕ) => T.right.nth n
| -(n + 1 : ℕ) => T.left.nth n
#align turing.tape.nth Turing.Tape.nth
@[simp]
theorem Tape.nth_zero {Γ} [Inhabited Γ] (T : Tape Γ) : T.nth 0 = T.1 :=
rfl
#align turing.tape.nth_zero Turing.Tape.nth_zero
theorem Tape.right₀_nth {Γ} [Inhabited Γ] (T : Tape Γ) (n : ℕ) : T.right₀.nth n = T.nth n := by
cases n <;> simp only [Tape.nth, Tape.right₀, Int.ofNat_zero, ListBlank.nth_zero,
ListBlank.nth_succ, ListBlank.head_cons, ListBlank.tail_cons, Nat.zero_eq]
#align turing.tape.right₀_nth Turing.Tape.right₀_nth
@[simp]
theorem Tape.mk'_nth_nat {Γ} [Inhabited Γ] (L R : ListBlank Γ) (n : ℕ) :
(Tape.mk' L R).nth n = R.nth n := by
rw [← Tape.right₀_nth, Tape.mk'_right₀]
#align turing.tape.mk'_nth_nat Turing.Tape.mk'_nth_nat
@[simp]
theorem Tape.move_left_nth {Γ} [Inhabited Γ] :
∀ (T : Tape Γ) (i : ℤ), (T.move Dir.left).nth i = T.nth (i - 1)
| ⟨_, L, _⟩, -(n + 1 : ℕ) => (ListBlank.nth_succ _ _).symm
| ⟨_, L, _⟩, 0 => (ListBlank.nth_zero _).symm
| ⟨a, L, R⟩, 1 => (ListBlank.nth_zero _).trans (ListBlank.head_cons _ _)
| ⟨a, L, R⟩, (n + 1 : ℕ) + 1 => by
rw [add_sub_cancel_right]
change (R.cons a).nth (n + 1) = R.nth n
rw [ListBlank.nth_succ, ListBlank.tail_cons]
#align turing.tape.move_left_nth Turing.Tape.move_left_nth
@[simp]
theorem Tape.move_right_nth {Γ} [Inhabited Γ] (T : Tape Γ) (i : ℤ) :
(T.move Dir.right).nth i = T.nth (i + 1) := by
conv => rhs; rw [← T.move_right_left]
rw [Tape.move_left_nth, add_sub_cancel_right]
#align turing.tape.move_right_nth Turing.Tape.move_right_nth
@[simp]
theorem Tape.move_right_n_head {Γ} [Inhabited Γ] (T : Tape Γ) (i : ℕ) :
((Tape.move Dir.right)^[i] T).head = T.nth i := by
induction i generalizing T
· rfl
· simp only [*, Tape.move_right_nth, Int.ofNat_succ, iterate_succ, Function.comp_apply]
#align turing.tape.move_right_n_head Turing.Tape.move_right_n_head
def Tape.write {Γ} [Inhabited Γ] (b : Γ) (T : Tape Γ) : Tape Γ :=
{ T with head := b }
#align turing.tape.write Turing.Tape.write
@[simp]
theorem Tape.write_self {Γ} [Inhabited Γ] : ∀ T : Tape Γ, T.write T.1 = T := by
rintro ⟨⟩; rfl
#align turing.tape.write_self Turing.Tape.write_self
@[simp]
theorem Tape.write_nth {Γ} [Inhabited Γ] (b : Γ) :
∀ (T : Tape Γ) {i : ℤ}, (T.write b).nth i = if i = 0 then b else T.nth i
| _, 0 => rfl
| _, (_ + 1 : ℕ) => rfl
| _, -(_ + 1 : ℕ) => rfl
#align turing.tape.write_nth Turing.Tape.write_nth
@[simp]
theorem Tape.write_mk' {Γ} [Inhabited Γ] (a b : Γ) (L R : ListBlank Γ) :
(Tape.mk' L (R.cons a)).write b = Tape.mk' L (R.cons b) := by
simp only [Tape.write, Tape.mk', ListBlank.head_cons, ListBlank.tail_cons, eq_self_iff_true,
and_self_iff]
#align turing.tape.write_mk' Turing.Tape.write_mk'
def Tape.map {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] (f : PointedMap Γ Γ') (T : Tape Γ) : Tape Γ' :=
⟨f T.1, T.2.map f, T.3.map f⟩
#align turing.tape.map Turing.Tape.map
@[simp]
| Mathlib/Computability/TuringMachine.lean | 693 | 695 | theorem Tape.map_fst {Γ Γ'} [Inhabited Γ] [Inhabited Γ'] (f : PointedMap Γ Γ') :
∀ T : Tape Γ, (T.map f).1 = f T.1 := by |
rintro ⟨⟩; rfl
|
import Mathlib.Analysis.Convex.Cone.Basic
import Mathlib.Analysis.InnerProductSpace.Projection
#align_import analysis.convex.cone.dual from "leanprover-community/mathlib"@"915591b2bb3ea303648db07284a161a7f2a9e3d4"
open Set LinearMap
open scoped Classical
open Pointwise
variable {𝕜 E F G : Type*}
section Dual
variable {H : Type*} [NormedAddCommGroup H] [InnerProductSpace ℝ H] (s t : Set H)
open RealInnerProductSpace
def Set.innerDualCone (s : Set H) : ConvexCone ℝ H where
carrier := { y | ∀ x ∈ s, 0 ≤ ⟪x, y⟫ }
smul_mem' c hc y hy x hx := by
rw [real_inner_smul_right]
exact mul_nonneg hc.le (hy x hx)
add_mem' u hu v hv x hx := by
rw [inner_add_right]
exact add_nonneg (hu x hx) (hv x hx)
#align set.inner_dual_cone Set.innerDualCone
@[simp]
theorem mem_innerDualCone (y : H) (s : Set H) : y ∈ s.innerDualCone ↔ ∀ x ∈ s, 0 ≤ ⟪x, y⟫ :=
Iff.rfl
#align mem_inner_dual_cone mem_innerDualCone
@[simp]
theorem innerDualCone_empty : (∅ : Set H).innerDualCone = ⊤ :=
eq_top_iff.mpr fun _ _ _ => False.elim
#align inner_dual_cone_empty innerDualCone_empty
@[simp]
theorem innerDualCone_zero : (0 : Set H).innerDualCone = ⊤ :=
eq_top_iff.mpr fun _ _ y (hy : y = 0) => hy.symm ▸ (inner_zero_left _).ge
#align inner_dual_cone_zero innerDualCone_zero
@[simp]
theorem innerDualCone_univ : (univ : Set H).innerDualCone = 0 := by
suffices ∀ x : H, x ∈ (univ : Set H).innerDualCone → x = 0 by
apply SetLike.coe_injective
exact eq_singleton_iff_unique_mem.mpr ⟨fun x _ => (inner_zero_right _).ge, this⟩
exact fun x hx => by simpa [← real_inner_self_nonpos] using hx (-x) (mem_univ _)
#align inner_dual_cone_univ innerDualCone_univ
theorem innerDualCone_le_innerDualCone (h : t ⊆ s) : s.innerDualCone ≤ t.innerDualCone :=
fun _ hy x hx => hy x (h hx)
#align inner_dual_cone_le_inner_dual_cone innerDualCone_le_innerDualCone
theorem pointed_innerDualCone : s.innerDualCone.Pointed := fun x _ => by rw [inner_zero_right]
#align pointed_inner_dual_cone pointed_innerDualCone
theorem innerDualCone_singleton (x : H) :
({x} : Set H).innerDualCone = (ConvexCone.positive ℝ ℝ).comap (innerₛₗ ℝ x) :=
ConvexCone.ext fun _ => forall_eq
#align inner_dual_cone_singleton innerDualCone_singleton
theorem innerDualCone_union (s t : Set H) :
(s ∪ t).innerDualCone = s.innerDualCone ⊓ t.innerDualCone :=
le_antisymm (le_inf (fun _ hx _ hy => hx _ <| Or.inl hy) fun _ hx _ hy => hx _ <| Or.inr hy)
fun _ hx _ => Or.rec (hx.1 _) (hx.2 _)
#align inner_dual_cone_union innerDualCone_union
theorem innerDualCone_insert (x : H) (s : Set H) :
(insert x s).innerDualCone = Set.innerDualCone {x} ⊓ s.innerDualCone := by
rw [insert_eq, innerDualCone_union]
#align inner_dual_cone_insert innerDualCone_insert
theorem innerDualCone_iUnion {ι : Sort*} (f : ι → Set H) :
(⋃ i, f i).innerDualCone = ⨅ i, (f i).innerDualCone := by
refine le_antisymm (le_iInf fun i x hx y hy => hx _ <| mem_iUnion_of_mem _ hy) ?_
intro x hx y hy
rw [ConvexCone.mem_iInf] at hx
obtain ⟨j, hj⟩ := mem_iUnion.mp hy
exact hx _ _ hj
#align inner_dual_cone_Union innerDualCone_iUnion
theorem innerDualCone_sUnion (S : Set (Set H)) :
(⋃₀ S).innerDualCone = sInf (Set.innerDualCone '' S) := by
simp_rw [sInf_image, sUnion_eq_biUnion, innerDualCone_iUnion]
#align inner_dual_cone_sUnion innerDualCone_sUnion
| Mathlib/Analysis/Convex/Cone/InnerDual.lean | 125 | 127 | theorem innerDualCone_eq_iInter_innerDualCone_singleton :
(s.innerDualCone : Set H) = ⋂ i : s, (({↑i} : Set H).innerDualCone : Set H) := by |
rw [← ConvexCone.coe_iInf, ← innerDualCone_iUnion, iUnion_of_singleton_coe]
|
import Mathlib.Topology.Constructions
import Mathlib.Topology.ContinuousOn
#align_import topology.bases from "leanprover-community/mathlib"@"bcfa726826abd57587355b4b5b7e78ad6527b7e4"
open Set Filter Function Topology
noncomputable section
namespace TopologicalSpace
universe u
variable {α : Type u} {β : Type*} [t : TopologicalSpace α] {B : Set (Set α)} {s : Set α}
structure IsTopologicalBasis (s : Set (Set α)) : Prop where
exists_subset_inter : ∀ t₁ ∈ s, ∀ t₂ ∈ s, ∀ x ∈ t₁ ∩ t₂, ∃ t₃ ∈ s, x ∈ t₃ ∧ t₃ ⊆ t₁ ∩ t₂
sUnion_eq : ⋃₀ s = univ
eq_generateFrom : t = generateFrom s
#align topological_space.is_topological_basis TopologicalSpace.IsTopologicalBasis
theorem IsTopologicalBasis.insert_empty {s : Set (Set α)} (h : IsTopologicalBasis s) :
IsTopologicalBasis (insert ∅ s) := by
refine ⟨?_, by rw [sUnion_insert, empty_union, h.sUnion_eq], ?_⟩
· rintro t₁ (rfl | h₁) t₂ (rfl | h₂) x ⟨hx₁, hx₂⟩
· cases hx₁
· cases hx₁
· cases hx₂
· obtain ⟨t₃, h₃, hs⟩ := h.exists_subset_inter _ h₁ _ h₂ x ⟨hx₁, hx₂⟩
exact ⟨t₃, .inr h₃, hs⟩
· rw [h.eq_generateFrom]
refine le_antisymm (le_generateFrom fun t => ?_) (generateFrom_anti <| subset_insert ∅ s)
rintro (rfl | ht)
· exact @isOpen_empty _ (generateFrom s)
· exact .basic t ht
#align topological_space.is_topological_basis.insert_empty TopologicalSpace.IsTopologicalBasis.insert_empty
theorem IsTopologicalBasis.diff_empty {s : Set (Set α)} (h : IsTopologicalBasis s) :
IsTopologicalBasis (s \ {∅}) := by
refine ⟨?_, by rw [sUnion_diff_singleton_empty, h.sUnion_eq], ?_⟩
· rintro t₁ ⟨h₁, -⟩ t₂ ⟨h₂, -⟩ x hx
obtain ⟨t₃, h₃, hs⟩ := h.exists_subset_inter _ h₁ _ h₂ x hx
exact ⟨t₃, ⟨h₃, Nonempty.ne_empty ⟨x, hs.1⟩⟩, hs⟩
· rw [h.eq_generateFrom]
refine le_antisymm (generateFrom_anti diff_subset) (le_generateFrom fun t ht => ?_)
obtain rfl | he := eq_or_ne t ∅
· exact @isOpen_empty _ (generateFrom _)
· exact .basic t ⟨ht, he⟩
#align topological_space.is_topological_basis.diff_empty TopologicalSpace.IsTopologicalBasis.diff_empty
| Mathlib/Topology/Bases.lean | 108 | 119 | theorem isTopologicalBasis_of_subbasis {s : Set (Set α)} (hs : t = generateFrom s) :
IsTopologicalBasis ((fun f => ⋂₀ f) '' { f : Set (Set α) | f.Finite ∧ f ⊆ s }) := by |
subst t; letI := generateFrom s
refine ⟨?_, ?_, le_antisymm (le_generateFrom ?_) <| generateFrom_anti fun t ht => ?_⟩
· rintro _ ⟨t₁, ⟨hft₁, ht₁b⟩, rfl⟩ _ ⟨t₂, ⟨hft₂, ht₂b⟩, rfl⟩ x h
exact ⟨_, ⟨_, ⟨hft₁.union hft₂, union_subset ht₁b ht₂b⟩, sInter_union t₁ t₂⟩, h, Subset.rfl⟩
· rw [sUnion_image, iUnion₂_eq_univ_iff]
exact fun x => ⟨∅, ⟨finite_empty, empty_subset _⟩, sInter_empty.substr <| mem_univ x⟩
· rintro _ ⟨t, ⟨hft, htb⟩, rfl⟩
exact hft.isOpen_sInter fun s hs ↦ GenerateOpen.basic _ <| htb hs
· rw [← sInter_singleton t]
exact ⟨{t}, ⟨finite_singleton t, singleton_subset_iff.2 ht⟩, rfl⟩
|
import Mathlib.Algebra.GroupPower.IterateHom
import Mathlib.Analysis.SpecificLimits.Basic
import Mathlib.Order.Iterate
import Mathlib.Order.SemiconjSup
import Mathlib.Tactic.Monotonicity
import Mathlib.Topology.Order.MonotoneContinuity
#align_import dynamics.circle.rotation_number.translation_number from "leanprover-community/mathlib"@"f2ce6086713c78a7f880485f7917ea547a215982"
open scoped Classical
open Filter Set Int Topology
open Function hiding Commute
structure CircleDeg1Lift extends ℝ →o ℝ : Type where
map_add_one' : ∀ x, toFun (x + 1) = toFun x + 1
#align circle_deg1_lift CircleDeg1Lift
namespace CircleDeg1Lift
instance : FunLike CircleDeg1Lift ℝ ℝ where
coe f := f.toFun
coe_injective' | ⟨⟨_, _⟩, _⟩, ⟨⟨_, _⟩, _⟩, rfl => rfl
instance : OrderHomClass CircleDeg1Lift ℝ ℝ where
map_rel f _ _ h := f.monotone' h
@[simp] theorem coe_mk (f h) : ⇑(mk f h) = f := rfl
#align circle_deg1_lift.coe_mk CircleDeg1Lift.coe_mk
variable (f g : CircleDeg1Lift)
@[simp] theorem coe_toOrderHom : ⇑f.toOrderHom = f := rfl
protected theorem monotone : Monotone f := f.monotone'
#align circle_deg1_lift.monotone CircleDeg1Lift.monotone
@[mono] theorem mono {x y} (h : x ≤ y) : f x ≤ f y := f.monotone h
#align circle_deg1_lift.mono CircleDeg1Lift.mono
theorem strictMono_iff_injective : StrictMono f ↔ Injective f :=
f.monotone.strictMono_iff_injective
#align circle_deg1_lift.strict_mono_iff_injective CircleDeg1Lift.strictMono_iff_injective
@[simp]
theorem map_add_one : ∀ x, f (x + 1) = f x + 1 :=
f.map_add_one'
#align circle_deg1_lift.map_add_one CircleDeg1Lift.map_add_one
@[simp]
theorem map_one_add (x : ℝ) : f (1 + x) = 1 + f x := by rw [add_comm, map_add_one, add_comm 1]
#align circle_deg1_lift.map_one_add CircleDeg1Lift.map_one_add
#noalign circle_deg1_lift.coe_inj -- Use `DFunLike.coe_inj`
@[ext]
theorem ext ⦃f g : CircleDeg1Lift⦄ (h : ∀ x, f x = g x) : f = g :=
DFunLike.ext f g h
#align circle_deg1_lift.ext CircleDeg1Lift.ext
theorem ext_iff {f g : CircleDeg1Lift} : f = g ↔ ∀ x, f x = g x :=
DFunLike.ext_iff
#align circle_deg1_lift.ext_iff CircleDeg1Lift.ext_iff
instance : Monoid CircleDeg1Lift where
mul f g :=
{ toOrderHom := f.1.comp g.1
map_add_one' := fun x => by simp [map_add_one] }
one := ⟨.id, fun _ => rfl⟩
mul_one f := rfl
one_mul f := rfl
mul_assoc f₁ f₂ f₃ := DFunLike.coe_injective rfl
instance : Inhabited CircleDeg1Lift := ⟨1⟩
@[simp]
theorem coe_mul : ⇑(f * g) = f ∘ g :=
rfl
#align circle_deg1_lift.coe_mul CircleDeg1Lift.coe_mul
theorem mul_apply (x) : (f * g) x = f (g x) :=
rfl
#align circle_deg1_lift.mul_apply CircleDeg1Lift.mul_apply
@[simp]
theorem coe_one : ⇑(1 : CircleDeg1Lift) = id :=
rfl
#align circle_deg1_lift.coe_one CircleDeg1Lift.coe_one
instance unitsHasCoeToFun : CoeFun CircleDeg1Liftˣ fun _ => ℝ → ℝ :=
⟨fun f => ⇑(f : CircleDeg1Lift)⟩
#align circle_deg1_lift.units_has_coe_to_fun CircleDeg1Lift.unitsHasCoeToFun
#noalign circle_deg1_lift.units_coe -- now LHS = RHS
@[simp]
theorem units_inv_apply_apply (f : CircleDeg1Liftˣ) (x : ℝ) :
(f⁻¹ : CircleDeg1Liftˣ) (f x) = x := by simp only [← mul_apply, f.inv_mul, coe_one, id]
#align circle_deg1_lift.units_inv_apply_apply CircleDeg1Lift.units_inv_apply_apply
@[simp]
theorem units_apply_inv_apply (f : CircleDeg1Liftˣ) (x : ℝ) :
f ((f⁻¹ : CircleDeg1Liftˣ) x) = x := by simp only [← mul_apply, f.mul_inv, coe_one, id]
#align circle_deg1_lift.units_apply_inv_apply CircleDeg1Lift.units_apply_inv_apply
def toOrderIso : CircleDeg1Liftˣ →* ℝ ≃o ℝ where
toFun f :=
{ toFun := f
invFun := ⇑f⁻¹
left_inv := units_inv_apply_apply f
right_inv := units_apply_inv_apply f
map_rel_iff' := ⟨fun h => by simpa using mono (↑f⁻¹) h, mono f⟩ }
map_one' := rfl
map_mul' f g := rfl
#align circle_deg1_lift.to_order_iso CircleDeg1Lift.toOrderIso
@[simp]
theorem coe_toOrderIso (f : CircleDeg1Liftˣ) : ⇑(toOrderIso f) = f :=
rfl
#align circle_deg1_lift.coe_to_order_iso CircleDeg1Lift.coe_toOrderIso
@[simp]
theorem coe_toOrderIso_symm (f : CircleDeg1Liftˣ) :
⇑(toOrderIso f).symm = (f⁻¹ : CircleDeg1Liftˣ) :=
rfl
#align circle_deg1_lift.coe_to_order_iso_symm CircleDeg1Lift.coe_toOrderIso_symm
@[simp]
theorem coe_toOrderIso_inv (f : CircleDeg1Liftˣ) : ⇑(toOrderIso f)⁻¹ = (f⁻¹ : CircleDeg1Liftˣ) :=
rfl
#align circle_deg1_lift.coe_to_order_iso_inv CircleDeg1Lift.coe_toOrderIso_inv
theorem isUnit_iff_bijective {f : CircleDeg1Lift} : IsUnit f ↔ Bijective f :=
⟨fun ⟨u, h⟩ => h ▸ (toOrderIso u).bijective, fun h =>
Units.isUnit
{ val := f
inv :=
{ toFun := (Equiv.ofBijective f h).symm
monotone' := fun x y hxy =>
(f.strictMono_iff_injective.2 h.1).le_iff_le.1
(by simp only [Equiv.ofBijective_apply_symm_apply f h, hxy])
map_add_one' := fun x =>
h.1 <| by simp only [Equiv.ofBijective_apply_symm_apply f, f.map_add_one] }
val_inv := ext <| Equiv.ofBijective_apply_symm_apply f h
inv_val := ext <| Equiv.ofBijective_symm_apply_apply f h }⟩
#align circle_deg1_lift.is_unit_iff_bijective CircleDeg1Lift.isUnit_iff_bijective
theorem coe_pow : ∀ n : ℕ, ⇑(f ^ n) = f^[n]
| 0 => rfl
| n + 1 => by
ext x
simp [coe_pow n, pow_succ]
#align circle_deg1_lift.coe_pow CircleDeg1Lift.coe_pow
theorem semiconjBy_iff_semiconj {f g₁ g₂ : CircleDeg1Lift} :
SemiconjBy f g₁ g₂ ↔ Semiconj f g₁ g₂ :=
ext_iff
#align circle_deg1_lift.semiconj_by_iff_semiconj CircleDeg1Lift.semiconjBy_iff_semiconj
theorem commute_iff_commute {f g : CircleDeg1Lift} : Commute f g ↔ Function.Commute f g :=
ext_iff
#align circle_deg1_lift.commute_iff_commute CircleDeg1Lift.commute_iff_commute
def translate : Multiplicative ℝ →* CircleDeg1Liftˣ := MonoidHom.toHomUnits <|
{ toFun := fun x =>
⟨⟨fun y => Multiplicative.toAdd x + y, fun _ _ h => add_le_add_left h _⟩, fun _ =>
(add_assoc _ _ _).symm⟩
map_one' := ext <| zero_add
map_mul' := fun _ _ => ext <| add_assoc _ _ }
#align circle_deg1_lift.translate CircleDeg1Lift.translate
@[simp]
theorem translate_apply (x y : ℝ) : translate (Multiplicative.ofAdd x) y = x + y :=
rfl
#align circle_deg1_lift.translate_apply CircleDeg1Lift.translate_apply
@[simp]
theorem translate_inv_apply (x y : ℝ) : (translate <| Multiplicative.ofAdd x)⁻¹ y = -x + y :=
rfl
#align circle_deg1_lift.translate_inv_apply CircleDeg1Lift.translate_inv_apply
@[simp]
theorem translate_zpow (x : ℝ) (n : ℤ) :
translate (Multiplicative.ofAdd x) ^ n = translate (Multiplicative.ofAdd <| ↑n * x) := by
simp only [← zsmul_eq_mul, ofAdd_zsmul, MonoidHom.map_zpow]
#align circle_deg1_lift.translate_zpow CircleDeg1Lift.translate_zpow
@[simp]
theorem translate_pow (x : ℝ) (n : ℕ) :
translate (Multiplicative.ofAdd x) ^ n = translate (Multiplicative.ofAdd <| ↑n * x) :=
translate_zpow x n
#align circle_deg1_lift.translate_pow CircleDeg1Lift.translate_pow
@[simp]
theorem translate_iterate (x : ℝ) (n : ℕ) :
(translate (Multiplicative.ofAdd x))^[n] = translate (Multiplicative.ofAdd <| ↑n * x) := by
rw [← coe_pow, ← Units.val_pow_eq_pow_val, translate_pow]
#align circle_deg1_lift.translate_iterate CircleDeg1Lift.translate_iterate
theorem commute_nat_add (n : ℕ) : Function.Commute f (n + ·) := by
simpa only [nsmul_one, add_left_iterate] using Function.Commute.iterate_right f.map_one_add n
#align circle_deg1_lift.commute_nat_add CircleDeg1Lift.commute_nat_add
theorem commute_add_nat (n : ℕ) : Function.Commute f (· + n) := by
simp only [add_comm _ (n : ℝ), f.commute_nat_add n]
#align circle_deg1_lift.commute_add_nat CircleDeg1Lift.commute_add_nat
theorem commute_sub_nat (n : ℕ) : Function.Commute f (· - n) := by
simpa only [sub_eq_add_neg] using
(f.commute_add_nat n).inverses_right (Equiv.addRight _).right_inv (Equiv.addRight _).left_inv
#align circle_deg1_lift.commute_sub_nat CircleDeg1Lift.commute_sub_nat
theorem commute_add_int : ∀ n : ℤ, Function.Commute f (· + n)
| (n : ℕ) => f.commute_add_nat n
| -[n+1] => by simpa [sub_eq_add_neg] using f.commute_sub_nat (n + 1)
#align circle_deg1_lift.commute_add_int CircleDeg1Lift.commute_add_int
theorem commute_int_add (n : ℤ) : Function.Commute f (n + ·) := by
simpa only [add_comm _ (n : ℝ)] using f.commute_add_int n
#align circle_deg1_lift.commute_int_add CircleDeg1Lift.commute_int_add
theorem commute_sub_int (n : ℤ) : Function.Commute f (· - n) := by
simpa only [sub_eq_add_neg] using
(f.commute_add_int n).inverses_right (Equiv.addRight _).right_inv (Equiv.addRight _).left_inv
#align circle_deg1_lift.commute_sub_int CircleDeg1Lift.commute_sub_int
@[simp]
theorem map_int_add (m : ℤ) (x : ℝ) : f (m + x) = m + f x :=
f.commute_int_add m x
#align circle_deg1_lift.map_int_add CircleDeg1Lift.map_int_add
@[simp]
theorem map_add_int (x : ℝ) (m : ℤ) : f (x + m) = f x + m :=
f.commute_add_int m x
#align circle_deg1_lift.map_add_int CircleDeg1Lift.map_add_int
@[simp]
theorem map_sub_int (x : ℝ) (n : ℤ) : f (x - n) = f x - n :=
f.commute_sub_int n x
#align circle_deg1_lift.map_sub_int CircleDeg1Lift.map_sub_int
@[simp]
theorem map_add_nat (x : ℝ) (n : ℕ) : f (x + n) = f x + n :=
f.map_add_int x n
#align circle_deg1_lift.map_add_nat CircleDeg1Lift.map_add_nat
@[simp]
theorem map_nat_add (n : ℕ) (x : ℝ) : f (n + x) = n + f x :=
f.map_int_add n x
#align circle_deg1_lift.map_nat_add CircleDeg1Lift.map_nat_add
@[simp]
theorem map_sub_nat (x : ℝ) (n : ℕ) : f (x - n) = f x - n :=
f.map_sub_int x n
#align circle_deg1_lift.map_sub_nat CircleDeg1Lift.map_sub_nat
theorem map_int_of_map_zero (n : ℤ) : f n = f 0 + n := by rw [← f.map_add_int, zero_add]
#align circle_deg1_lift.map_int_of_map_zero CircleDeg1Lift.map_int_of_map_zero
@[simp]
theorem map_fract_sub_fract_eq (x : ℝ) : f (fract x) - fract x = f x - x := by
rw [Int.fract, f.map_sub_int, sub_sub_sub_cancel_right]
#align circle_deg1_lift.map_fract_sub_fract_eq CircleDeg1Lift.map_fract_sub_fract_eq
noncomputable instance : Lattice CircleDeg1Lift where
sup f g :=
{ toFun := fun x => max (f x) (g x)
monotone' := fun x y h => max_le_max (f.mono h) (g.mono h)
-- TODO: generalize to `Monotone.max`
map_add_one' := fun x => by simp [max_add_add_right] }
le f g := ∀ x, f x ≤ g x
le_refl f x := le_refl (f x)
le_trans f₁ f₂ f₃ h₁₂ h₂₃ x := le_trans (h₁₂ x) (h₂₃ x)
le_antisymm f₁ f₂ h₁₂ h₂₁ := ext fun x => le_antisymm (h₁₂ x) (h₂₁ x)
le_sup_left f g x := le_max_left (f x) (g x)
le_sup_right f g x := le_max_right (f x) (g x)
sup_le f₁ f₂ f₃ h₁ h₂ x := max_le (h₁ x) (h₂ x)
inf f g :=
{ toFun := fun x => min (f x) (g x)
monotone' := fun x y h => min_le_min (f.mono h) (g.mono h)
map_add_one' := fun x => by simp [min_add_add_right] }
inf_le_left f g x := min_le_left (f x) (g x)
inf_le_right f g x := min_le_right (f x) (g x)
le_inf f₁ f₂ f₃ h₂ h₃ x := le_min (h₂ x) (h₃ x)
@[simp]
theorem sup_apply (x : ℝ) : (f ⊔ g) x = max (f x) (g x) :=
rfl
#align circle_deg1_lift.sup_apply CircleDeg1Lift.sup_apply
@[simp]
theorem inf_apply (x : ℝ) : (f ⊓ g) x = min (f x) (g x) :=
rfl
#align circle_deg1_lift.inf_apply CircleDeg1Lift.inf_apply
theorem iterate_monotone (n : ℕ) : Monotone fun f : CircleDeg1Lift => f^[n] := fun f _ h =>
f.monotone.iterate_le_of_le h _
#align circle_deg1_lift.iterate_monotone CircleDeg1Lift.iterate_monotone
theorem iterate_mono {f g : CircleDeg1Lift} (h : f ≤ g) (n : ℕ) : f^[n] ≤ g^[n] :=
iterate_monotone n h
#align circle_deg1_lift.iterate_mono CircleDeg1Lift.iterate_mono
theorem pow_mono {f g : CircleDeg1Lift} (h : f ≤ g) (n : ℕ) : f ^ n ≤ g ^ n := fun x => by
simp only [coe_pow, iterate_mono h n x]
#align circle_deg1_lift.pow_mono CircleDeg1Lift.pow_mono
theorem pow_monotone (n : ℕ) : Monotone fun f : CircleDeg1Lift => f ^ n := fun _ _ h => pow_mono h n
#align circle_deg1_lift.pow_monotone CircleDeg1Lift.pow_monotone
theorem map_le_of_map_zero (x : ℝ) : f x ≤ f 0 + ⌈x⌉ :=
calc
f x ≤ f ⌈x⌉ := f.monotone <| le_ceil _
_ = f 0 + ⌈x⌉ := f.map_int_of_map_zero _
#align circle_deg1_lift.map_le_of_map_zero CircleDeg1Lift.map_le_of_map_zero
theorem map_map_zero_le : f (g 0) ≤ f 0 + ⌈g 0⌉ :=
f.map_le_of_map_zero (g 0)
#align circle_deg1_lift.map_map_zero_le CircleDeg1Lift.map_map_zero_le
theorem floor_map_map_zero_le : ⌊f (g 0)⌋ ≤ ⌊f 0⌋ + ⌈g 0⌉ :=
calc
⌊f (g 0)⌋ ≤ ⌊f 0 + ⌈g 0⌉⌋ := floor_mono <| f.map_map_zero_le g
_ = ⌊f 0⌋ + ⌈g 0⌉ := floor_add_int _ _
#align circle_deg1_lift.floor_map_map_zero_le CircleDeg1Lift.floor_map_map_zero_le
theorem ceil_map_map_zero_le : ⌈f (g 0)⌉ ≤ ⌈f 0⌉ + ⌈g 0⌉ :=
calc
⌈f (g 0)⌉ ≤ ⌈f 0 + ⌈g 0⌉⌉ := ceil_mono <| f.map_map_zero_le g
_ = ⌈f 0⌉ + ⌈g 0⌉ := ceil_add_int _ _
#align circle_deg1_lift.ceil_map_map_zero_le CircleDeg1Lift.ceil_map_map_zero_le
theorem map_map_zero_lt : f (g 0) < f 0 + g 0 + 1 :=
calc
f (g 0) ≤ f 0 + ⌈g 0⌉ := f.map_map_zero_le g
_ < f 0 + (g 0 + 1) := add_lt_add_left (ceil_lt_add_one _) _
_ = f 0 + g 0 + 1 := (add_assoc _ _ _).symm
#align circle_deg1_lift.map_map_zero_lt CircleDeg1Lift.map_map_zero_lt
theorem le_map_of_map_zero (x : ℝ) : f 0 + ⌊x⌋ ≤ f x :=
calc
f 0 + ⌊x⌋ = f ⌊x⌋ := (f.map_int_of_map_zero _).symm
_ ≤ f x := f.monotone <| floor_le _
#align circle_deg1_lift.le_map_of_map_zero CircleDeg1Lift.le_map_of_map_zero
theorem le_map_map_zero : f 0 + ⌊g 0⌋ ≤ f (g 0) :=
f.le_map_of_map_zero (g 0)
#align circle_deg1_lift.le_map_map_zero CircleDeg1Lift.le_map_map_zero
theorem le_floor_map_map_zero : ⌊f 0⌋ + ⌊g 0⌋ ≤ ⌊f (g 0)⌋ :=
calc
⌊f 0⌋ + ⌊g 0⌋ = ⌊f 0 + ⌊g 0⌋⌋ := (floor_add_int _ _).symm
_ ≤ ⌊f (g 0)⌋ := floor_mono <| f.le_map_map_zero g
#align circle_deg1_lift.le_floor_map_map_zero CircleDeg1Lift.le_floor_map_map_zero
theorem le_ceil_map_map_zero : ⌈f 0⌉ + ⌊g 0⌋ ≤ ⌈(f * g) 0⌉ :=
calc
⌈f 0⌉ + ⌊g 0⌋ = ⌈f 0 + ⌊g 0⌋⌉ := (ceil_add_int _ _).symm
_ ≤ ⌈f (g 0)⌉ := ceil_mono <| f.le_map_map_zero g
#align circle_deg1_lift.le_ceil_map_map_zero CircleDeg1Lift.le_ceil_map_map_zero
theorem lt_map_map_zero : f 0 + g 0 - 1 < f (g 0) :=
calc
f 0 + g 0 - 1 = f 0 + (g 0 - 1) := add_sub_assoc _ _ _
_ < f 0 + ⌊g 0⌋ := add_lt_add_left (sub_one_lt_floor _) _
_ ≤ f (g 0) := f.le_map_map_zero g
#align circle_deg1_lift.lt_map_map_zero CircleDeg1Lift.lt_map_map_zero
theorem dist_map_map_zero_lt : dist (f 0 + g 0) (f (g 0)) < 1 := by
rw [dist_comm, Real.dist_eq, abs_lt, lt_sub_iff_add_lt', sub_lt_iff_lt_add', ← sub_eq_add_neg]
exact ⟨f.lt_map_map_zero g, f.map_map_zero_lt g⟩
#align circle_deg1_lift.dist_map_map_zero_lt CircleDeg1Lift.dist_map_map_zero_lt
theorem dist_map_zero_lt_of_semiconj {f g₁ g₂ : CircleDeg1Lift} (h : Function.Semiconj f g₁ g₂) :
dist (g₁ 0) (g₂ 0) < 2 :=
calc
dist (g₁ 0) (g₂ 0) ≤ dist (g₁ 0) (f (g₁ 0) - f 0) + dist _ (g₂ 0) := dist_triangle _ _ _
_ = dist (f 0 + g₁ 0) (f (g₁ 0)) + dist (g₂ 0 + f 0) (g₂ (f 0)) := by
simp only [h.eq, Real.dist_eq, sub_sub, add_comm (f 0), sub_sub_eq_add_sub,
abs_sub_comm (g₂ (f 0))]
_ < 1 + 1 := add_lt_add (f.dist_map_map_zero_lt g₁) (g₂.dist_map_map_zero_lt f)
_ = 2 := one_add_one_eq_two
#align circle_deg1_lift.dist_map_zero_lt_of_semiconj CircleDeg1Lift.dist_map_zero_lt_of_semiconj
theorem dist_map_zero_lt_of_semiconjBy {f g₁ g₂ : CircleDeg1Lift} (h : SemiconjBy f g₁ g₂) :
dist (g₁ 0) (g₂ 0) < 2 :=
dist_map_zero_lt_of_semiconj <| semiconjBy_iff_semiconj.1 h
#align circle_deg1_lift.dist_map_zero_lt_of_semiconj_by CircleDeg1Lift.dist_map_zero_lt_of_semiconjBy
protected theorem tendsto_atBot : Tendsto f atBot atBot :=
tendsto_atBot_mono f.map_le_of_map_zero <| tendsto_atBot_add_const_left _ _ <|
(tendsto_atBot_mono fun x => (ceil_lt_add_one x).le) <|
tendsto_atBot_add_const_right _ _ tendsto_id
#align circle_deg1_lift.tendsto_at_bot CircleDeg1Lift.tendsto_atBot
protected theorem tendsto_atTop : Tendsto f atTop atTop :=
tendsto_atTop_mono f.le_map_of_map_zero <| tendsto_atTop_add_const_left _ _ <|
(tendsto_atTop_mono fun x => (sub_one_lt_floor x).le) <| by
simpa [sub_eq_add_neg] using tendsto_atTop_add_const_right _ _ tendsto_id
#align circle_deg1_lift.tendsto_at_top CircleDeg1Lift.tendsto_atTop
theorem continuous_iff_surjective : Continuous f ↔ Function.Surjective f :=
⟨fun h => h.surjective f.tendsto_atTop f.tendsto_atBot, f.monotone.continuous_of_surjective⟩
#align circle_deg1_lift.continuous_iff_surjective CircleDeg1Lift.continuous_iff_surjective
theorem iterate_le_of_map_le_add_int {x : ℝ} {m : ℤ} (h : f x ≤ x + m) (n : ℕ) :
f^[n] x ≤ x + n * m := by
simpa only [nsmul_eq_mul, add_right_iterate] using
(f.commute_add_int m).iterate_le_of_map_le f.monotone (monotone_id.add_const (m : ℝ)) h n
#align circle_deg1_lift.iterate_le_of_map_le_add_int CircleDeg1Lift.iterate_le_of_map_le_add_int
| Mathlib/Dynamics/Circle/RotationNumber/TranslationNumber.lean | 577 | 580 | theorem le_iterate_of_add_int_le_map {x : ℝ} {m : ℤ} (h : x + m ≤ f x) (n : ℕ) :
x + n * m ≤ f^[n] x := by |
simpa only [nsmul_eq_mul, add_right_iterate] using
(f.commute_add_int m).symm.iterate_le_of_map_le (monotone_id.add_const (m : ℝ)) f.monotone h n
|
import Mathlib.Algebra.GroupPower.IterateHom
import Mathlib.Analysis.SpecificLimits.Basic
import Mathlib.Order.Iterate
import Mathlib.Order.SemiconjSup
import Mathlib.Tactic.Monotonicity
import Mathlib.Topology.Order.MonotoneContinuity
#align_import dynamics.circle.rotation_number.translation_number from "leanprover-community/mathlib"@"f2ce6086713c78a7f880485f7917ea547a215982"
open scoped Classical
open Filter Set Int Topology
open Function hiding Commute
structure CircleDeg1Lift extends ℝ →o ℝ : Type where
map_add_one' : ∀ x, toFun (x + 1) = toFun x + 1
#align circle_deg1_lift CircleDeg1Lift
namespace CircleDeg1Lift
instance : FunLike CircleDeg1Lift ℝ ℝ where
coe f := f.toFun
coe_injective' | ⟨⟨_, _⟩, _⟩, ⟨⟨_, _⟩, _⟩, rfl => rfl
instance : OrderHomClass CircleDeg1Lift ℝ ℝ where
map_rel f _ _ h := f.monotone' h
@[simp] theorem coe_mk (f h) : ⇑(mk f h) = f := rfl
#align circle_deg1_lift.coe_mk CircleDeg1Lift.coe_mk
variable (f g : CircleDeg1Lift)
@[simp] theorem coe_toOrderHom : ⇑f.toOrderHom = f := rfl
protected theorem monotone : Monotone f := f.monotone'
#align circle_deg1_lift.monotone CircleDeg1Lift.monotone
@[mono] theorem mono {x y} (h : x ≤ y) : f x ≤ f y := f.monotone h
#align circle_deg1_lift.mono CircleDeg1Lift.mono
theorem strictMono_iff_injective : StrictMono f ↔ Injective f :=
f.monotone.strictMono_iff_injective
#align circle_deg1_lift.strict_mono_iff_injective CircleDeg1Lift.strictMono_iff_injective
@[simp]
theorem map_add_one : ∀ x, f (x + 1) = f x + 1 :=
f.map_add_one'
#align circle_deg1_lift.map_add_one CircleDeg1Lift.map_add_one
@[simp]
theorem map_one_add (x : ℝ) : f (1 + x) = 1 + f x := by rw [add_comm, map_add_one, add_comm 1]
#align circle_deg1_lift.map_one_add CircleDeg1Lift.map_one_add
#noalign circle_deg1_lift.coe_inj -- Use `DFunLike.coe_inj`
@[ext]
theorem ext ⦃f g : CircleDeg1Lift⦄ (h : ∀ x, f x = g x) : f = g :=
DFunLike.ext f g h
#align circle_deg1_lift.ext CircleDeg1Lift.ext
theorem ext_iff {f g : CircleDeg1Lift} : f = g ↔ ∀ x, f x = g x :=
DFunLike.ext_iff
#align circle_deg1_lift.ext_iff CircleDeg1Lift.ext_iff
instance : Monoid CircleDeg1Lift where
mul f g :=
{ toOrderHom := f.1.comp g.1
map_add_one' := fun x => by simp [map_add_one] }
one := ⟨.id, fun _ => rfl⟩
mul_one f := rfl
one_mul f := rfl
mul_assoc f₁ f₂ f₃ := DFunLike.coe_injective rfl
instance : Inhabited CircleDeg1Lift := ⟨1⟩
@[simp]
theorem coe_mul : ⇑(f * g) = f ∘ g :=
rfl
#align circle_deg1_lift.coe_mul CircleDeg1Lift.coe_mul
theorem mul_apply (x) : (f * g) x = f (g x) :=
rfl
#align circle_deg1_lift.mul_apply CircleDeg1Lift.mul_apply
@[simp]
theorem coe_one : ⇑(1 : CircleDeg1Lift) = id :=
rfl
#align circle_deg1_lift.coe_one CircleDeg1Lift.coe_one
instance unitsHasCoeToFun : CoeFun CircleDeg1Liftˣ fun _ => ℝ → ℝ :=
⟨fun f => ⇑(f : CircleDeg1Lift)⟩
#align circle_deg1_lift.units_has_coe_to_fun CircleDeg1Lift.unitsHasCoeToFun
#noalign circle_deg1_lift.units_coe -- now LHS = RHS
@[simp]
theorem units_inv_apply_apply (f : CircleDeg1Liftˣ) (x : ℝ) :
(f⁻¹ : CircleDeg1Liftˣ) (f x) = x := by simp only [← mul_apply, f.inv_mul, coe_one, id]
#align circle_deg1_lift.units_inv_apply_apply CircleDeg1Lift.units_inv_apply_apply
@[simp]
theorem units_apply_inv_apply (f : CircleDeg1Liftˣ) (x : ℝ) :
f ((f⁻¹ : CircleDeg1Liftˣ) x) = x := by simp only [← mul_apply, f.mul_inv, coe_one, id]
#align circle_deg1_lift.units_apply_inv_apply CircleDeg1Lift.units_apply_inv_apply
def toOrderIso : CircleDeg1Liftˣ →* ℝ ≃o ℝ where
toFun f :=
{ toFun := f
invFun := ⇑f⁻¹
left_inv := units_inv_apply_apply f
right_inv := units_apply_inv_apply f
map_rel_iff' := ⟨fun h => by simpa using mono (↑f⁻¹) h, mono f⟩ }
map_one' := rfl
map_mul' f g := rfl
#align circle_deg1_lift.to_order_iso CircleDeg1Lift.toOrderIso
@[simp]
theorem coe_toOrderIso (f : CircleDeg1Liftˣ) : ⇑(toOrderIso f) = f :=
rfl
#align circle_deg1_lift.coe_to_order_iso CircleDeg1Lift.coe_toOrderIso
@[simp]
theorem coe_toOrderIso_symm (f : CircleDeg1Liftˣ) :
⇑(toOrderIso f).symm = (f⁻¹ : CircleDeg1Liftˣ) :=
rfl
#align circle_deg1_lift.coe_to_order_iso_symm CircleDeg1Lift.coe_toOrderIso_symm
@[simp]
theorem coe_toOrderIso_inv (f : CircleDeg1Liftˣ) : ⇑(toOrderIso f)⁻¹ = (f⁻¹ : CircleDeg1Liftˣ) :=
rfl
#align circle_deg1_lift.coe_to_order_iso_inv CircleDeg1Lift.coe_toOrderIso_inv
theorem isUnit_iff_bijective {f : CircleDeg1Lift} : IsUnit f ↔ Bijective f :=
⟨fun ⟨u, h⟩ => h ▸ (toOrderIso u).bijective, fun h =>
Units.isUnit
{ val := f
inv :=
{ toFun := (Equiv.ofBijective f h).symm
monotone' := fun x y hxy =>
(f.strictMono_iff_injective.2 h.1).le_iff_le.1
(by simp only [Equiv.ofBijective_apply_symm_apply f h, hxy])
map_add_one' := fun x =>
h.1 <| by simp only [Equiv.ofBijective_apply_symm_apply f, f.map_add_one] }
val_inv := ext <| Equiv.ofBijective_apply_symm_apply f h
inv_val := ext <| Equiv.ofBijective_symm_apply_apply f h }⟩
#align circle_deg1_lift.is_unit_iff_bijective CircleDeg1Lift.isUnit_iff_bijective
theorem coe_pow : ∀ n : ℕ, ⇑(f ^ n) = f^[n]
| 0 => rfl
| n + 1 => by
ext x
simp [coe_pow n, pow_succ]
#align circle_deg1_lift.coe_pow CircleDeg1Lift.coe_pow
theorem semiconjBy_iff_semiconj {f g₁ g₂ : CircleDeg1Lift} :
SemiconjBy f g₁ g₂ ↔ Semiconj f g₁ g₂ :=
ext_iff
#align circle_deg1_lift.semiconj_by_iff_semiconj CircleDeg1Lift.semiconjBy_iff_semiconj
theorem commute_iff_commute {f g : CircleDeg1Lift} : Commute f g ↔ Function.Commute f g :=
ext_iff
#align circle_deg1_lift.commute_iff_commute CircleDeg1Lift.commute_iff_commute
def translate : Multiplicative ℝ →* CircleDeg1Liftˣ := MonoidHom.toHomUnits <|
{ toFun := fun x =>
⟨⟨fun y => Multiplicative.toAdd x + y, fun _ _ h => add_le_add_left h _⟩, fun _ =>
(add_assoc _ _ _).symm⟩
map_one' := ext <| zero_add
map_mul' := fun _ _ => ext <| add_assoc _ _ }
#align circle_deg1_lift.translate CircleDeg1Lift.translate
@[simp]
theorem translate_apply (x y : ℝ) : translate (Multiplicative.ofAdd x) y = x + y :=
rfl
#align circle_deg1_lift.translate_apply CircleDeg1Lift.translate_apply
@[simp]
theorem translate_inv_apply (x y : ℝ) : (translate <| Multiplicative.ofAdd x)⁻¹ y = -x + y :=
rfl
#align circle_deg1_lift.translate_inv_apply CircleDeg1Lift.translate_inv_apply
@[simp]
theorem translate_zpow (x : ℝ) (n : ℤ) :
translate (Multiplicative.ofAdd x) ^ n = translate (Multiplicative.ofAdd <| ↑n * x) := by
simp only [← zsmul_eq_mul, ofAdd_zsmul, MonoidHom.map_zpow]
#align circle_deg1_lift.translate_zpow CircleDeg1Lift.translate_zpow
@[simp]
theorem translate_pow (x : ℝ) (n : ℕ) :
translate (Multiplicative.ofAdd x) ^ n = translate (Multiplicative.ofAdd <| ↑n * x) :=
translate_zpow x n
#align circle_deg1_lift.translate_pow CircleDeg1Lift.translate_pow
@[simp]
theorem translate_iterate (x : ℝ) (n : ℕ) :
(translate (Multiplicative.ofAdd x))^[n] = translate (Multiplicative.ofAdd <| ↑n * x) := by
rw [← coe_pow, ← Units.val_pow_eq_pow_val, translate_pow]
#align circle_deg1_lift.translate_iterate CircleDeg1Lift.translate_iterate
theorem commute_nat_add (n : ℕ) : Function.Commute f (n + ·) := by
simpa only [nsmul_one, add_left_iterate] using Function.Commute.iterate_right f.map_one_add n
#align circle_deg1_lift.commute_nat_add CircleDeg1Lift.commute_nat_add
theorem commute_add_nat (n : ℕ) : Function.Commute f (· + n) := by
simp only [add_comm _ (n : ℝ), f.commute_nat_add n]
#align circle_deg1_lift.commute_add_nat CircleDeg1Lift.commute_add_nat
theorem commute_sub_nat (n : ℕ) : Function.Commute f (· - n) := by
simpa only [sub_eq_add_neg] using
(f.commute_add_nat n).inverses_right (Equiv.addRight _).right_inv (Equiv.addRight _).left_inv
#align circle_deg1_lift.commute_sub_nat CircleDeg1Lift.commute_sub_nat
theorem commute_add_int : ∀ n : ℤ, Function.Commute f (· + n)
| (n : ℕ) => f.commute_add_nat n
| -[n+1] => by simpa [sub_eq_add_neg] using f.commute_sub_nat (n + 1)
#align circle_deg1_lift.commute_add_int CircleDeg1Lift.commute_add_int
theorem commute_int_add (n : ℤ) : Function.Commute f (n + ·) := by
simpa only [add_comm _ (n : ℝ)] using f.commute_add_int n
#align circle_deg1_lift.commute_int_add CircleDeg1Lift.commute_int_add
theorem commute_sub_int (n : ℤ) : Function.Commute f (· - n) := by
simpa only [sub_eq_add_neg] using
(f.commute_add_int n).inverses_right (Equiv.addRight _).right_inv (Equiv.addRight _).left_inv
#align circle_deg1_lift.commute_sub_int CircleDeg1Lift.commute_sub_int
@[simp]
theorem map_int_add (m : ℤ) (x : ℝ) : f (m + x) = m + f x :=
f.commute_int_add m x
#align circle_deg1_lift.map_int_add CircleDeg1Lift.map_int_add
@[simp]
theorem map_add_int (x : ℝ) (m : ℤ) : f (x + m) = f x + m :=
f.commute_add_int m x
#align circle_deg1_lift.map_add_int CircleDeg1Lift.map_add_int
@[simp]
theorem map_sub_int (x : ℝ) (n : ℤ) : f (x - n) = f x - n :=
f.commute_sub_int n x
#align circle_deg1_lift.map_sub_int CircleDeg1Lift.map_sub_int
@[simp]
theorem map_add_nat (x : ℝ) (n : ℕ) : f (x + n) = f x + n :=
f.map_add_int x n
#align circle_deg1_lift.map_add_nat CircleDeg1Lift.map_add_nat
@[simp]
theorem map_nat_add (n : ℕ) (x : ℝ) : f (n + x) = n + f x :=
f.map_int_add n x
#align circle_deg1_lift.map_nat_add CircleDeg1Lift.map_nat_add
@[simp]
theorem map_sub_nat (x : ℝ) (n : ℕ) : f (x - n) = f x - n :=
f.map_sub_int x n
#align circle_deg1_lift.map_sub_nat CircleDeg1Lift.map_sub_nat
theorem map_int_of_map_zero (n : ℤ) : f n = f 0 + n := by rw [← f.map_add_int, zero_add]
#align circle_deg1_lift.map_int_of_map_zero CircleDeg1Lift.map_int_of_map_zero
@[simp]
theorem map_fract_sub_fract_eq (x : ℝ) : f (fract x) - fract x = f x - x := by
rw [Int.fract, f.map_sub_int, sub_sub_sub_cancel_right]
#align circle_deg1_lift.map_fract_sub_fract_eq CircleDeg1Lift.map_fract_sub_fract_eq
noncomputable instance : Lattice CircleDeg1Lift where
sup f g :=
{ toFun := fun x => max (f x) (g x)
monotone' := fun x y h => max_le_max (f.mono h) (g.mono h)
-- TODO: generalize to `Monotone.max`
map_add_one' := fun x => by simp [max_add_add_right] }
le f g := ∀ x, f x ≤ g x
le_refl f x := le_refl (f x)
le_trans f₁ f₂ f₃ h₁₂ h₂₃ x := le_trans (h₁₂ x) (h₂₃ x)
le_antisymm f₁ f₂ h₁₂ h₂₁ := ext fun x => le_antisymm (h₁₂ x) (h₂₁ x)
le_sup_left f g x := le_max_left (f x) (g x)
le_sup_right f g x := le_max_right (f x) (g x)
sup_le f₁ f₂ f₃ h₁ h₂ x := max_le (h₁ x) (h₂ x)
inf f g :=
{ toFun := fun x => min (f x) (g x)
monotone' := fun x y h => min_le_min (f.mono h) (g.mono h)
map_add_one' := fun x => by simp [min_add_add_right] }
inf_le_left f g x := min_le_left (f x) (g x)
inf_le_right f g x := min_le_right (f x) (g x)
le_inf f₁ f₂ f₃ h₂ h₃ x := le_min (h₂ x) (h₃ x)
@[simp]
theorem sup_apply (x : ℝ) : (f ⊔ g) x = max (f x) (g x) :=
rfl
#align circle_deg1_lift.sup_apply CircleDeg1Lift.sup_apply
@[simp]
theorem inf_apply (x : ℝ) : (f ⊓ g) x = min (f x) (g x) :=
rfl
#align circle_deg1_lift.inf_apply CircleDeg1Lift.inf_apply
theorem iterate_monotone (n : ℕ) : Monotone fun f : CircleDeg1Lift => f^[n] := fun f _ h =>
f.monotone.iterate_le_of_le h _
#align circle_deg1_lift.iterate_monotone CircleDeg1Lift.iterate_monotone
theorem iterate_mono {f g : CircleDeg1Lift} (h : f ≤ g) (n : ℕ) : f^[n] ≤ g^[n] :=
iterate_monotone n h
#align circle_deg1_lift.iterate_mono CircleDeg1Lift.iterate_mono
theorem pow_mono {f g : CircleDeg1Lift} (h : f ≤ g) (n : ℕ) : f ^ n ≤ g ^ n := fun x => by
simp only [coe_pow, iterate_mono h n x]
#align circle_deg1_lift.pow_mono CircleDeg1Lift.pow_mono
theorem pow_monotone (n : ℕ) : Monotone fun f : CircleDeg1Lift => f ^ n := fun _ _ h => pow_mono h n
#align circle_deg1_lift.pow_monotone CircleDeg1Lift.pow_monotone
theorem map_le_of_map_zero (x : ℝ) : f x ≤ f 0 + ⌈x⌉ :=
calc
f x ≤ f ⌈x⌉ := f.monotone <| le_ceil _
_ = f 0 + ⌈x⌉ := f.map_int_of_map_zero _
#align circle_deg1_lift.map_le_of_map_zero CircleDeg1Lift.map_le_of_map_zero
theorem map_map_zero_le : f (g 0) ≤ f 0 + ⌈g 0⌉ :=
f.map_le_of_map_zero (g 0)
#align circle_deg1_lift.map_map_zero_le CircleDeg1Lift.map_map_zero_le
theorem floor_map_map_zero_le : ⌊f (g 0)⌋ ≤ ⌊f 0⌋ + ⌈g 0⌉ :=
calc
⌊f (g 0)⌋ ≤ ⌊f 0 + ⌈g 0⌉⌋ := floor_mono <| f.map_map_zero_le g
_ = ⌊f 0⌋ + ⌈g 0⌉ := floor_add_int _ _
#align circle_deg1_lift.floor_map_map_zero_le CircleDeg1Lift.floor_map_map_zero_le
theorem ceil_map_map_zero_le : ⌈f (g 0)⌉ ≤ ⌈f 0⌉ + ⌈g 0⌉ :=
calc
⌈f (g 0)⌉ ≤ ⌈f 0 + ⌈g 0⌉⌉ := ceil_mono <| f.map_map_zero_le g
_ = ⌈f 0⌉ + ⌈g 0⌉ := ceil_add_int _ _
#align circle_deg1_lift.ceil_map_map_zero_le CircleDeg1Lift.ceil_map_map_zero_le
theorem map_map_zero_lt : f (g 0) < f 0 + g 0 + 1 :=
calc
f (g 0) ≤ f 0 + ⌈g 0⌉ := f.map_map_zero_le g
_ < f 0 + (g 0 + 1) := add_lt_add_left (ceil_lt_add_one _) _
_ = f 0 + g 0 + 1 := (add_assoc _ _ _).symm
#align circle_deg1_lift.map_map_zero_lt CircleDeg1Lift.map_map_zero_lt
theorem le_map_of_map_zero (x : ℝ) : f 0 + ⌊x⌋ ≤ f x :=
calc
f 0 + ⌊x⌋ = f ⌊x⌋ := (f.map_int_of_map_zero _).symm
_ ≤ f x := f.monotone <| floor_le _
#align circle_deg1_lift.le_map_of_map_zero CircleDeg1Lift.le_map_of_map_zero
theorem le_map_map_zero : f 0 + ⌊g 0⌋ ≤ f (g 0) :=
f.le_map_of_map_zero (g 0)
#align circle_deg1_lift.le_map_map_zero CircleDeg1Lift.le_map_map_zero
theorem le_floor_map_map_zero : ⌊f 0⌋ + ⌊g 0⌋ ≤ ⌊f (g 0)⌋ :=
calc
⌊f 0⌋ + ⌊g 0⌋ = ⌊f 0 + ⌊g 0⌋⌋ := (floor_add_int _ _).symm
_ ≤ ⌊f (g 0)⌋ := floor_mono <| f.le_map_map_zero g
#align circle_deg1_lift.le_floor_map_map_zero CircleDeg1Lift.le_floor_map_map_zero
theorem le_ceil_map_map_zero : ⌈f 0⌉ + ⌊g 0⌋ ≤ ⌈(f * g) 0⌉ :=
calc
⌈f 0⌉ + ⌊g 0⌋ = ⌈f 0 + ⌊g 0⌋⌉ := (ceil_add_int _ _).symm
_ ≤ ⌈f (g 0)⌉ := ceil_mono <| f.le_map_map_zero g
#align circle_deg1_lift.le_ceil_map_map_zero CircleDeg1Lift.le_ceil_map_map_zero
theorem lt_map_map_zero : f 0 + g 0 - 1 < f (g 0) :=
calc
f 0 + g 0 - 1 = f 0 + (g 0 - 1) := add_sub_assoc _ _ _
_ < f 0 + ⌊g 0⌋ := add_lt_add_left (sub_one_lt_floor _) _
_ ≤ f (g 0) := f.le_map_map_zero g
#align circle_deg1_lift.lt_map_map_zero CircleDeg1Lift.lt_map_map_zero
theorem dist_map_map_zero_lt : dist (f 0 + g 0) (f (g 0)) < 1 := by
rw [dist_comm, Real.dist_eq, abs_lt, lt_sub_iff_add_lt', sub_lt_iff_lt_add', ← sub_eq_add_neg]
exact ⟨f.lt_map_map_zero g, f.map_map_zero_lt g⟩
#align circle_deg1_lift.dist_map_map_zero_lt CircleDeg1Lift.dist_map_map_zero_lt
theorem dist_map_zero_lt_of_semiconj {f g₁ g₂ : CircleDeg1Lift} (h : Function.Semiconj f g₁ g₂) :
dist (g₁ 0) (g₂ 0) < 2 :=
calc
dist (g₁ 0) (g₂ 0) ≤ dist (g₁ 0) (f (g₁ 0) - f 0) + dist _ (g₂ 0) := dist_triangle _ _ _
_ = dist (f 0 + g₁ 0) (f (g₁ 0)) + dist (g₂ 0 + f 0) (g₂ (f 0)) := by
simp only [h.eq, Real.dist_eq, sub_sub, add_comm (f 0), sub_sub_eq_add_sub,
abs_sub_comm (g₂ (f 0))]
_ < 1 + 1 := add_lt_add (f.dist_map_map_zero_lt g₁) (g₂.dist_map_map_zero_lt f)
_ = 2 := one_add_one_eq_two
#align circle_deg1_lift.dist_map_zero_lt_of_semiconj CircleDeg1Lift.dist_map_zero_lt_of_semiconj
theorem dist_map_zero_lt_of_semiconjBy {f g₁ g₂ : CircleDeg1Lift} (h : SemiconjBy f g₁ g₂) :
dist (g₁ 0) (g₂ 0) < 2 :=
dist_map_zero_lt_of_semiconj <| semiconjBy_iff_semiconj.1 h
#align circle_deg1_lift.dist_map_zero_lt_of_semiconj_by CircleDeg1Lift.dist_map_zero_lt_of_semiconjBy
protected theorem tendsto_atBot : Tendsto f atBot atBot :=
tendsto_atBot_mono f.map_le_of_map_zero <| tendsto_atBot_add_const_left _ _ <|
(tendsto_atBot_mono fun x => (ceil_lt_add_one x).le) <|
tendsto_atBot_add_const_right _ _ tendsto_id
#align circle_deg1_lift.tendsto_at_bot CircleDeg1Lift.tendsto_atBot
protected theorem tendsto_atTop : Tendsto f atTop atTop :=
tendsto_atTop_mono f.le_map_of_map_zero <| tendsto_atTop_add_const_left _ _ <|
(tendsto_atTop_mono fun x => (sub_one_lt_floor x).le) <| by
simpa [sub_eq_add_neg] using tendsto_atTop_add_const_right _ _ tendsto_id
#align circle_deg1_lift.tendsto_at_top CircleDeg1Lift.tendsto_atTop
theorem continuous_iff_surjective : Continuous f ↔ Function.Surjective f :=
⟨fun h => h.surjective f.tendsto_atTop f.tendsto_atBot, f.monotone.continuous_of_surjective⟩
#align circle_deg1_lift.continuous_iff_surjective CircleDeg1Lift.continuous_iff_surjective
theorem iterate_le_of_map_le_add_int {x : ℝ} {m : ℤ} (h : f x ≤ x + m) (n : ℕ) :
f^[n] x ≤ x + n * m := by
simpa only [nsmul_eq_mul, add_right_iterate] using
(f.commute_add_int m).iterate_le_of_map_le f.monotone (monotone_id.add_const (m : ℝ)) h n
#align circle_deg1_lift.iterate_le_of_map_le_add_int CircleDeg1Lift.iterate_le_of_map_le_add_int
theorem le_iterate_of_add_int_le_map {x : ℝ} {m : ℤ} (h : x + m ≤ f x) (n : ℕ) :
x + n * m ≤ f^[n] x := by
simpa only [nsmul_eq_mul, add_right_iterate] using
(f.commute_add_int m).symm.iterate_le_of_map_le (monotone_id.add_const (m : ℝ)) f.monotone h n
#align circle_deg1_lift.le_iterate_of_add_int_le_map CircleDeg1Lift.le_iterate_of_add_int_le_map
theorem iterate_eq_of_map_eq_add_int {x : ℝ} {m : ℤ} (h : f x = x + m) (n : ℕ) :
f^[n] x = x + n * m := by
simpa only [nsmul_eq_mul, add_right_iterate] using (f.commute_add_int m).iterate_eq_of_map_eq n h
#align circle_deg1_lift.iterate_eq_of_map_eq_add_int CircleDeg1Lift.iterate_eq_of_map_eq_add_int
| Mathlib/Dynamics/Circle/RotationNumber/TranslationNumber.lean | 588 | 591 | theorem iterate_pos_le_iff {x : ℝ} {m : ℤ} {n : ℕ} (hn : 0 < n) :
f^[n] x ≤ x + n * m ↔ f x ≤ x + m := by |
simpa only [nsmul_eq_mul, add_right_iterate] using
(f.commute_add_int m).iterate_pos_le_iff_map_le f.monotone (strictMono_id.add_const (m : ℝ)) hn
|
import Mathlib.Algebra.Algebra.Subalgebra.Unitization
import Mathlib.Analysis.RCLike.Basic
import Mathlib.Topology.Algebra.StarSubalgebra
import Mathlib.Topology.ContinuousFunction.ContinuousMapZero
import Mathlib.Topology.ContinuousFunction.Weierstrass
#align_import topology.continuous_function.stone_weierstrass from "leanprover-community/mathlib"@"16e59248c0ebafabd5d071b1cd41743eb8698ffb"
noncomputable section
namespace ContinuousMap
variable {X : Type*} [TopologicalSpace X] [CompactSpace X]
open scoped Polynomial
def attachBound (f : C(X, ℝ)) : C(X, Set.Icc (-‖f‖) ‖f‖) where
toFun x := ⟨f x, ⟨neg_norm_le_apply f x, apply_le_norm f x⟩⟩
#align continuous_map.attach_bound ContinuousMap.attachBound
@[simp]
theorem attachBound_apply_coe (f : C(X, ℝ)) (x : X) : ((attachBound f) x : ℝ) = f x :=
rfl
#align continuous_map.attach_bound_apply_coe ContinuousMap.attachBound_apply_coe
theorem polynomial_comp_attachBound (A : Subalgebra ℝ C(X, ℝ)) (f : A) (g : ℝ[X]) :
(g.toContinuousMapOn (Set.Icc (-‖f‖) ‖f‖)).comp (f : C(X, ℝ)).attachBound =
Polynomial.aeval f g := by
ext
simp only [ContinuousMap.coe_comp, Function.comp_apply, ContinuousMap.attachBound_apply_coe,
Polynomial.toContinuousMapOn_apply, Polynomial.aeval_subalgebra_coe,
Polynomial.aeval_continuousMap_apply, Polynomial.toContinuousMap_apply]
-- This used to be `rw`, but we need `erw` after leanprover/lean4#2644
erw [ContinuousMap.attachBound_apply_coe]
#align continuous_map.polynomial_comp_attach_bound ContinuousMap.polynomial_comp_attachBound
theorem polynomial_comp_attachBound_mem (A : Subalgebra ℝ C(X, ℝ)) (f : A) (g : ℝ[X]) :
(g.toContinuousMapOn (Set.Icc (-‖f‖) ‖f‖)).comp (f : C(X, ℝ)).attachBound ∈ A := by
rw [polynomial_comp_attachBound]
apply SetLike.coe_mem
#align continuous_map.polynomial_comp_attach_bound_mem ContinuousMap.polynomial_comp_attachBound_mem
theorem comp_attachBound_mem_closure (A : Subalgebra ℝ C(X, ℝ)) (f : A)
(p : C(Set.Icc (-‖f‖) ‖f‖, ℝ)) : p.comp (attachBound (f : C(X, ℝ))) ∈ A.topologicalClosure := by
-- `p` itself is in the closure of polynomials, by the Weierstrass theorem,
have mem_closure : p ∈ (polynomialFunctions (Set.Icc (-‖f‖) ‖f‖)).topologicalClosure :=
continuousMap_mem_polynomialFunctions_closure _ _ p
-- and so there are polynomials arbitrarily close.
have frequently_mem_polynomials := mem_closure_iff_frequently.mp mem_closure
-- To prove `p.comp (attachBound f)` is in the closure of `A`,
-- we show there are elements of `A` arbitrarily close.
apply mem_closure_iff_frequently.mpr
-- To show that, we pull back the polynomials close to `p`,
refine
((compRightContinuousMap ℝ (attachBound (f : C(X, ℝ)))).continuousAt
p).tendsto.frequently_map
_ ?_ frequently_mem_polynomials
-- but need to show that those pullbacks are actually in `A`.
rintro _ ⟨g, ⟨-, rfl⟩⟩
simp only [SetLike.mem_coe, AlgHom.coe_toRingHom, compRightContinuousMap_apply,
Polynomial.toContinuousMapOnAlgHom_apply]
apply polynomial_comp_attachBound_mem
#align continuous_map.comp_attach_bound_mem_closure ContinuousMap.comp_attachBound_mem_closure
| Mathlib/Topology/ContinuousFunction/StoneWeierstrass.lean | 116 | 121 | theorem abs_mem_subalgebra_closure (A : Subalgebra ℝ C(X, ℝ)) (f : A) :
|(f : C(X, ℝ))| ∈ A.topologicalClosure := by |
let f' := attachBound (f : C(X, ℝ))
let abs : C(Set.Icc (-‖f‖) ‖f‖, ℝ) := { toFun := fun x : Set.Icc (-‖f‖) ‖f‖ => |(x : ℝ)| }
change abs.comp f' ∈ A.topologicalClosure
apply comp_attachBound_mem_closure
|
import Mathlib.Algebra.Polynomial.Degree.Definitions
import Mathlib.Data.ENat.Basic
#align_import data.polynomial.degree.trailing_degree from "leanprover-community/mathlib"@"302eab4f46abb63de520828de78c04cb0f9b5836"
noncomputable section
open Function Polynomial Finsupp Finset
open scoped Polynomial
namespace Polynomial
universe u v
variable {R : Type u} {S : Type v} {a b : R} {n m : ℕ}
section Semiring
variable [Semiring R] {p q r : R[X]}
def trailingDegree (p : R[X]) : ℕ∞ :=
p.support.min
#align polynomial.trailing_degree Polynomial.trailingDegree
theorem trailingDegree_lt_wf : WellFounded fun p q : R[X] => trailingDegree p < trailingDegree q :=
InvImage.wf trailingDegree wellFounded_lt
#align polynomial.trailing_degree_lt_wf Polynomial.trailingDegree_lt_wf
def natTrailingDegree (p : R[X]) : ℕ :=
(trailingDegree p).getD 0
#align polynomial.nat_trailing_degree Polynomial.natTrailingDegree
def trailingCoeff (p : R[X]) : R :=
coeff p (natTrailingDegree p)
#align polynomial.trailing_coeff Polynomial.trailingCoeff
def TrailingMonic (p : R[X]) :=
trailingCoeff p = (1 : R)
#align polynomial.trailing_monic Polynomial.TrailingMonic
theorem TrailingMonic.def : TrailingMonic p ↔ trailingCoeff p = 1 :=
Iff.rfl
#align polynomial.trailing_monic.def Polynomial.TrailingMonic.def
instance TrailingMonic.decidable [DecidableEq R] : Decidable (TrailingMonic p) :=
inferInstanceAs <| Decidable (trailingCoeff p = (1 : R))
#align polynomial.trailing_monic.decidable Polynomial.TrailingMonic.decidable
@[simp]
theorem TrailingMonic.trailingCoeff {p : R[X]} (hp : p.TrailingMonic) : trailingCoeff p = 1 :=
hp
#align polynomial.trailing_monic.trailing_coeff Polynomial.TrailingMonic.trailingCoeff
@[simp]
theorem trailingDegree_zero : trailingDegree (0 : R[X]) = ⊤ :=
rfl
#align polynomial.trailing_degree_zero Polynomial.trailingDegree_zero
@[simp]
theorem trailingCoeff_zero : trailingCoeff (0 : R[X]) = 0 :=
rfl
#align polynomial.trailing_coeff_zero Polynomial.trailingCoeff_zero
@[simp]
theorem natTrailingDegree_zero : natTrailingDegree (0 : R[X]) = 0 :=
rfl
#align polynomial.nat_trailing_degree_zero Polynomial.natTrailingDegree_zero
theorem trailingDegree_eq_top : trailingDegree p = ⊤ ↔ p = 0 :=
⟨fun h => support_eq_empty.1 (Finset.min_eq_top.1 h), fun h => by simp [h]⟩
#align polynomial.trailing_degree_eq_top Polynomial.trailingDegree_eq_top
theorem trailingDegree_eq_natTrailingDegree (hp : p ≠ 0) :
trailingDegree p = (natTrailingDegree p : ℕ∞) := by
let ⟨n, hn⟩ :=
not_forall.1 (mt Option.eq_none_iff_forall_not_mem.2 (mt trailingDegree_eq_top.1 hp))
have hn : trailingDegree p = n := Classical.not_not.1 hn
rw [natTrailingDegree, hn]
rfl
#align polynomial.trailing_degree_eq_nat_trailing_degree Polynomial.trailingDegree_eq_natTrailingDegree
theorem trailingDegree_eq_iff_natTrailingDegree_eq {p : R[X]} {n : ℕ} (hp : p ≠ 0) :
p.trailingDegree = n ↔ p.natTrailingDegree = n := by
rw [trailingDegree_eq_natTrailingDegree hp]
exact WithTop.coe_eq_coe
#align polynomial.trailing_degree_eq_iff_nat_trailing_degree_eq Polynomial.trailingDegree_eq_iff_natTrailingDegree_eq
theorem trailingDegree_eq_iff_natTrailingDegree_eq_of_pos {p : R[X]} {n : ℕ} (hn : 0 < n) :
p.trailingDegree = n ↔ p.natTrailingDegree = n := by
constructor
· intro H
rwa [← trailingDegree_eq_iff_natTrailingDegree_eq]
rintro rfl
rw [trailingDegree_zero] at H
exact Option.noConfusion H
· intro H
rwa [trailingDegree_eq_iff_natTrailingDegree_eq]
rintro rfl
rw [natTrailingDegree_zero] at H
rw [H] at hn
exact lt_irrefl _ hn
#align polynomial.trailing_degree_eq_iff_nat_trailing_degree_eq_of_pos Polynomial.trailingDegree_eq_iff_natTrailingDegree_eq_of_pos
theorem natTrailingDegree_eq_of_trailingDegree_eq_some {p : R[X]} {n : ℕ}
(h : trailingDegree p = n) : natTrailingDegree p = n :=
have hp0 : p ≠ 0 := fun hp0 => by rw [hp0] at h; exact Option.noConfusion h
Option.some_inj.1 <|
show (natTrailingDegree p : ℕ∞) = n by rwa [← trailingDegree_eq_natTrailingDegree hp0]
#align polynomial.nat_trailing_degree_eq_of_trailing_degree_eq_some Polynomial.natTrailingDegree_eq_of_trailingDegree_eq_some
@[simp]
theorem natTrailingDegree_le_trailingDegree : ↑(natTrailingDegree p) ≤ trailingDegree p := by
by_cases hp : p = 0;
· rw [hp, trailingDegree_zero]
exact le_top
rw [trailingDegree_eq_natTrailingDegree hp]
#align polynomial.nat_trailing_degree_le_trailing_degree Polynomial.natTrailingDegree_le_trailingDegree
theorem natTrailingDegree_eq_of_trailingDegree_eq [Semiring S] {q : S[X]}
(h : trailingDegree p = trailingDegree q) : natTrailingDegree p = natTrailingDegree q := by
unfold natTrailingDegree
rw [h]
#align polynomial.nat_trailing_degree_eq_of_trailing_degree_eq Polynomial.natTrailingDegree_eq_of_trailingDegree_eq
theorem trailingDegree_le_of_ne_zero (h : coeff p n ≠ 0) : trailingDegree p ≤ n :=
show @LE.le ℕ∞ _ p.support.min n from min_le (mem_support_iff.2 h)
#align polynomial.le_trailing_degree_of_ne_zero Polynomial.trailingDegree_le_of_ne_zero
theorem natTrailingDegree_le_of_ne_zero (h : coeff p n ≠ 0) : natTrailingDegree p ≤ n := by
have : WithTop.some (natTrailingDegree p) = Nat.cast (natTrailingDegree p) := rfl
rw [← WithTop.coe_le_coe, this, ← trailingDegree_eq_natTrailingDegree]
· exact trailingDegree_le_of_ne_zero h
· intro h
subst h
exact h rfl
#align polynomial.nat_trailing_degree_le_of_ne_zero Polynomial.natTrailingDegree_le_of_ne_zero
@[simp] lemma coeff_natTrailingDegree_eq_zero : coeff p p.natTrailingDegree = 0 ↔ p = 0 := by
constructor
· rintro h
by_contra hp
obtain ⟨n, hpn, hn⟩ := by simpa using min_mem_image_coe $ support_nonempty.2 hp
obtain rfl := (trailingDegree_eq_iff_natTrailingDegree_eq hp).1 hn.symm
exact hpn h
· rintro rfl
simp
lemma coeff_natTrailingDegree_ne_zero : coeff p p.natTrailingDegree ≠ 0 ↔ p ≠ 0 :=
coeff_natTrailingDegree_eq_zero.not
@[simp] lemma natTrailingDegree_eq_zero : natTrailingDegree p = 0 ↔ p = 0 ∨ coeff p 0 ≠ 0 := by
constructor
· rw [or_iff_not_imp_left]
rintro h hp
rwa [← h, coeff_natTrailingDegree_ne_zero]
· rintro (rfl | h)
· simp
· exact nonpos_iff_eq_zero.1 $ natTrailingDegree_le_of_ne_zero h
lemma trailingDegree_eq_zero : trailingDegree p = 0 ↔ coeff p 0 ≠ 0 := by
obtain rfl | hp := eq_or_ne p 0
· simp [WithTop.top_ne_zero (α := ℕ)]
· exact (trailingDegree_eq_iff_natTrailingDegree_eq hp).trans $
natTrailingDegree_eq_zero.trans $ or_iff_right hp
lemma natTrailingDegree_ne_zero : natTrailingDegree p ≠ 0 ↔ p ≠ 0 ∧ coeff p 0 = 0 :=
natTrailingDegree_eq_zero.not.trans $ by rw [not_or, not_ne_iff]
lemma trailingDegree_ne_zero : trailingDegree p ≠ 0 ↔ coeff p 0 = 0 :=
trailingDegree_eq_zero.not_left
@[simp] theorem trailingDegree_le_trailingDegree (h : coeff q (natTrailingDegree p) ≠ 0) :
trailingDegree q ≤ trailingDegree p := by
by_cases hp : p = 0
· rw [hp]
exact le_top
· rw [trailingDegree_eq_natTrailingDegree hp]
exact trailingDegree_le_of_ne_zero h
#align polynomial.trailing_degree_le_trailing_degree Polynomial.trailingDegree_le_trailingDegree
| Mathlib/Algebra/Polynomial/Degree/TrailingDegree.lean | 210 | 214 | theorem trailingDegree_ne_of_natTrailingDegree_ne {n : ℕ} :
p.natTrailingDegree ≠ n → trailingDegree p ≠ n := by |
-- Porting note: Needed to account for different coercion behaviour & add the lemma below
have : Nat.cast n = WithTop.some n := rfl
exact mt fun h => by rw [natTrailingDegree, h, this, ← WithTop.some_eq_coe, Option.getD_some]
|
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]
theorem image_id_eq : image (id : α → α) = id := by ext; simp
@[simp]
theorem image_id' (s : Set α) : (fun x => x) '' s = s := by
ext
simp
#align set.image_id' Set.image_id'
theorem image_id (s : Set α) : id '' s = s := by simp
#align set.image_id Set.image_id
lemma image_iterate_eq {f : α → α} {n : ℕ} : image (f^[n]) = (image f)^[n] := by
induction n with
| zero => simp
| succ n ih => rw [iterate_succ', iterate_succ', ← ih, image_comp_eq]
| Mathlib/Data/Set/Image.lean | 384 | 386 | theorem compl_compl_image [BooleanAlgebra α] (S : Set α) :
HasCompl.compl '' (HasCompl.compl '' S) = S := by |
rw [← image_comp, compl_comp_compl, image_id]
|
import Mathlib.Algebra.Homology.ImageToKernel
import Mathlib.Algebra.Homology.HomologicalComplex
import Mathlib.CategoryTheory.GradedObject
#align_import algebra.homology.homology from "leanprover-community/mathlib"@"618ea3d5c99240cd7000d8376924906a148bf9ff"
universe v u
open CategoryTheory CategoryTheory.Limits
variable {ι : Type*}
variable {V : Type u} [Category.{v} V] [HasZeroMorphisms V]
variable {c : ComplexShape ι} (C : HomologicalComplex V c)
open scoped Classical
open ZeroObject
noncomputable section
namespace HomologicalComplex
section Boundaries
variable [HasImages V]
abbrev boundaries (C : HomologicalComplex V c) (j : ι) : Subobject (C.X j) :=
imageSubobject (C.dTo j)
#align homological_complex.boundaries HomologicalComplex.boundaries
theorem boundaries_eq_imageSubobject [HasEqualizers V] {i j : ι} (r : c.Rel i j) :
C.boundaries j = imageSubobject (C.d i j) :=
C.image_to_eq_image r
#align homological_complex.boundaries_eq_image_subobject HomologicalComplex.boundaries_eq_imageSubobject
def boundariesIsoImage [HasEqualizers V] {i j : ι} (r : c.Rel i j) :
(C.boundaries j : V) ≅ image (C.d i j) :=
Subobject.isoOfEq _ _ (C.boundaries_eq_imageSubobject r) ≪≫ imageSubobjectIso (C.d i j)
#align homological_complex.boundaries_iso_image HomologicalComplex.boundariesIsoImage
| Mathlib/Algebra/Homology/Homology.lean | 97 | 100 | theorem boundaries_eq_bot [HasZeroObject V] {j} (h : ¬c.Rel (c.prev j) j) : C.boundaries j = ⊥ := by |
rw [eq_bot_iff]
refine imageSubobject_le _ 0 ?_
rw [C.dTo_eq_zero h, zero_comp]
|
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))
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
theorem IsLindelof.elim_countable_subfamily_closed {ι : Type v} (hs : IsLindelof s)
(t : ι → Set X) (htc : ∀ i, IsClosed (t i)) (hst : (s ∩ ⋂ i, t i) = ∅) :
∃ u : Set ι, u.Countable ∧ (s ∩ ⋂ i ∈ u, t i) = ∅ := by
let U := tᶜ
have hUo : ∀ i, IsOpen (U i) := by simp only [U, Pi.compl_apply, isOpen_compl_iff]; exact htc
have hsU : s ⊆ ⋃ i, U i := by
simp only [U, Pi.compl_apply]
rw [← compl_iInter]
apply disjoint_compl_left_iff_subset.mp
simp only [compl_iInter, compl_iUnion, compl_compl]
apply Disjoint.symm
exact disjoint_iff_inter_eq_empty.mpr hst
rcases hs.elim_countable_subcover U hUo hsU with ⟨u, ⟨hucount, husub⟩⟩
use u, hucount
rw [← disjoint_compl_left_iff_subset] at husub
simp only [U, Pi.compl_apply, compl_iUnion, compl_compl] at husub
exact disjoint_iff_inter_eq_empty.mp (Disjoint.symm husub)
theorem IsLindelof.inter_iInter_nonempty {ι : Type v} (hs : IsLindelof s) (t : ι → Set X)
(htc : ∀ i, IsClosed (t i)) (hst : ∀ u : Set ι, u.Countable ∧ (s ∩ ⋂ i ∈ u, t i).Nonempty) :
(s ∩ ⋂ i, t i).Nonempty := by
contrapose! hst
rcases hs.elim_countable_subfamily_closed t htc hst with ⟨u, ⟨_, husub⟩⟩
exact ⟨u, fun _ ↦ husub⟩
theorem IsLindelof.elim_countable_subcover_image {b : Set ι} {c : ι → Set X} (hs : IsLindelof s)
(hc₁ : ∀ i ∈ b, IsOpen (c i)) (hc₂ : s ⊆ ⋃ i ∈ b, c i) :
∃ b', b' ⊆ b ∧ Set.Countable b' ∧ s ⊆ ⋃ i ∈ b', c i := by
simp only [Subtype.forall', biUnion_eq_iUnion] at hc₁ hc₂
rcases hs.elim_countable_subcover (fun i ↦ c i : b → Set X) hc₁ hc₂ with ⟨d, hd⟩
refine ⟨Subtype.val '' d, by simp, Countable.image hd.1 Subtype.val, ?_⟩
rw [biUnion_image]
exact hd.2
theorem isLindelof_of_countable_subcover
(h : ∀ {ι : Type u} (U : ι → Set X), (∀ i, IsOpen (U i)) → (s ⊆ ⋃ i, U i) →
∃ t : Set ι, t.Countable ∧ s ⊆ ⋃ i ∈ t, U i) :
IsLindelof s := fun f hf hfs ↦ by
contrapose! h
simp only [ClusterPt, not_neBot, ← disjoint_iff, SetCoe.forall',
(nhds_basis_opens _).disjoint_iff_left] at h
choose fsub U hU hUf using h
refine ⟨s, U, fun x ↦ (hU x).2, fun x hx ↦ mem_iUnion.2 ⟨⟨x, hx⟩, (hU _).1 ⟩, ?_⟩
intro t ht h
have uinf := f.sets_of_superset (le_principal_iff.1 fsub) h
have uninf : ⋂ i ∈ t, (U i)ᶜ ∈ f := (countable_bInter_mem ht).mpr (fun _ _ ↦ hUf _)
rw [← compl_iUnion₂] at uninf
have uninf := compl_not_mem uninf
simp only [compl_compl] at uninf
contradiction
theorem isLindelof_of_countable_subfamily_closed
(h :
∀ {ι : Type u} (t : ι → Set X), (∀ i, IsClosed (t i)) → (s ∩ ⋂ i, t i) = ∅ →
∃ u : Set ι, u.Countable ∧ (s ∩ ⋂ i ∈ u, t i) = ∅) :
IsLindelof s :=
isLindelof_of_countable_subcover fun U hUo hsU ↦ by
rw [← disjoint_compl_right_iff_subset, compl_iUnion, disjoint_iff] at hsU
rcases h (fun i ↦ (U i)ᶜ) (fun i ↦ (hUo _).isClosed_compl) hsU with ⟨t, ht⟩
refine ⟨t, ?_⟩
rwa [← disjoint_compl_right_iff_subset, compl_iUnion₂, disjoint_iff]
theorem isLindelof_iff_countable_subcover :
IsLindelof s ↔ ∀ {ι : Type u} (U : ι → Set X),
(∀ i, IsOpen (U i)) → (s ⊆ ⋃ i, U i) → ∃ t : Set ι, t.Countable ∧ s ⊆ ⋃ i ∈ t, U i :=
⟨fun hs ↦ hs.elim_countable_subcover, isLindelof_of_countable_subcover⟩
theorem isLindelof_iff_countable_subfamily_closed :
IsLindelof s ↔ ∀ {ι : Type u} (t : ι → Set X),
(∀ i, IsClosed (t i)) → (s ∩ ⋂ i, t i) = ∅
→ ∃ u : Set ι, u.Countable ∧ (s ∩ ⋂ i ∈ u, t i) = ∅ :=
⟨fun hs ↦ hs.elim_countable_subfamily_closed, isLindelof_of_countable_subfamily_closed⟩
@[simp]
theorem isLindelof_empty : IsLindelof (∅ : Set X) := fun _f hnf _ hsf ↦
Not.elim hnf.ne <| empty_mem_iff_bot.1 <| le_principal_iff.1 hsf
@[simp]
theorem isLindelof_singleton {x : X} : IsLindelof ({x} : Set X) := fun f hf _ hfa ↦
⟨x, rfl, ClusterPt.of_le_nhds'
(hfa.trans <| by simpa only [principal_singleton] using pure_le_nhds x) hf⟩
theorem Set.Subsingleton.isLindelof (hs : s.Subsingleton) : IsLindelof s :=
Subsingleton.induction_on hs isLindelof_empty fun _ ↦ isLindelof_singleton
theorem Set.Countable.isLindelof_biUnion {s : Set ι} {f : ι → Set X} (hs : s.Countable)
(hf : ∀ i ∈ s, IsLindelof (f i)) : IsLindelof (⋃ i ∈ s, f i) := by
apply isLindelof_of_countable_subcover
intro i U hU hUcover
have hiU : ∀ i ∈ s, f i ⊆ ⋃ i, U i :=
fun _ is ↦ _root_.subset_trans (subset_biUnion_of_mem is) hUcover
have iSets := fun i is ↦ (hf i is).elim_countable_subcover U hU (hiU i is)
choose! r hr using iSets
use ⋃ i ∈ s, r i
constructor
· refine (Countable.biUnion_iff hs).mpr ?h.left.a
exact fun s hs ↦ (hr s hs).1
· refine iUnion₂_subset ?h.right.h
intro i is
simp only [mem_iUnion, exists_prop, iUnion_exists, biUnion_and']
intro x hx
exact mem_biUnion is ((hr i is).2 hx)
theorem Set.Finite.isLindelof_biUnion {s : Set ι} {f : ι → Set X} (hs : s.Finite)
(hf : ∀ i ∈ s, IsLindelof (f i)) : IsLindelof (⋃ i ∈ s, f i) :=
Set.Countable.isLindelof_biUnion (countable hs) hf
theorem Finset.isLindelof_biUnion (s : Finset ι) {f : ι → Set X} (hf : ∀ i ∈ s, IsLindelof (f i)) :
IsLindelof (⋃ i ∈ s, f i) :=
s.finite_toSet.isLindelof_biUnion hf
theorem isLindelof_accumulate {K : ℕ → Set X} (hK : ∀ n, IsLindelof (K n)) (n : ℕ) :
IsLindelof (Accumulate K n) :=
(finite_le_nat n).isLindelof_biUnion fun k _ => hK k
theorem Set.Countable.isLindelof_sUnion {S : Set (Set X)} (hf : S.Countable)
(hc : ∀ s ∈ S, IsLindelof s) : IsLindelof (⋃₀ S) := by
rw [sUnion_eq_biUnion]; exact hf.isLindelof_biUnion hc
theorem Set.Finite.isLindelof_sUnion {S : Set (Set X)} (hf : S.Finite)
(hc : ∀ s ∈ S, IsLindelof s) : IsLindelof (⋃₀ S) := by
rw [sUnion_eq_biUnion]; exact hf.isLindelof_biUnion hc
theorem isLindelof_iUnion {ι : Sort*} {f : ι → Set X} [Countable ι] (h : ∀ i, IsLindelof (f i)) :
IsLindelof (⋃ i, f i) := (countable_range f).isLindelof_sUnion <| forall_mem_range.2 h
theorem Set.Countable.isLindelof (hs : s.Countable) : IsLindelof s :=
biUnion_of_singleton s ▸ hs.isLindelof_biUnion fun _ _ => isLindelof_singleton
theorem Set.Finite.isLindelof (hs : s.Finite) : IsLindelof s :=
biUnion_of_singleton s ▸ hs.isLindelof_biUnion fun _ _ => isLindelof_singleton
theorem IsLindelof.countable_of_discrete [DiscreteTopology X] (hs : IsLindelof s) :
s.Countable := by
have : ∀ x : X, ({x} : Set X) ∈ 𝓝 x := by simp [nhds_discrete]
rcases hs.elim_nhds_subcover (fun x => {x}) fun x _ => this x with ⟨t, ht, _, hssubt⟩
rw [biUnion_of_singleton] at hssubt
exact ht.mono hssubt
theorem isLindelof_iff_countable [DiscreteTopology X] : IsLindelof s ↔ s.Countable :=
⟨fun h => h.countable_of_discrete, fun h => h.isLindelof⟩
theorem IsLindelof.union (hs : IsLindelof s) (ht : IsLindelof t) : IsLindelof (s ∪ t) := by
rw [union_eq_iUnion]; exact isLindelof_iUnion fun b => by cases b <;> assumption
protected theorem IsLindelof.insert (hs : IsLindelof s) (a) : IsLindelof (insert a s) :=
isLindelof_singleton.union hs
theorem isLindelof_open_iff_eq_countable_iUnion_of_isTopologicalBasis (b : ι → Set X)
(hb : IsTopologicalBasis (Set.range b)) (hb' : ∀ i, IsLindelof (b i)) (U : Set X) :
IsLindelof U ∧ IsOpen U ↔ ∃ s : Set ι, s.Countable ∧ U = ⋃ i ∈ s, b i := by
constructor
· rintro ⟨h₁, h₂⟩
obtain ⟨Y, f, rfl, hf⟩ := hb.open_eq_iUnion h₂
choose f' hf' using hf
have : b ∘ f' = f := funext hf'
subst this
obtain ⟨t, ht⟩ :=
h₁.elim_countable_subcover (b ∘ f') (fun i => hb.isOpen (Set.mem_range_self _)) Subset.rfl
refine ⟨t.image f', Countable.image (ht.1) f', le_antisymm ?_ ?_⟩
· refine Set.Subset.trans ht.2 ?_
simp only [Set.iUnion_subset_iff]
intro i hi
rw [← Set.iUnion_subtype (fun x : ι => x ∈ t.image f') fun i => b i.1]
exact Set.subset_iUnion (fun i : t.image f' => b i) ⟨_, mem_image_of_mem _ hi⟩
· apply Set.iUnion₂_subset
rintro i hi
obtain ⟨j, -, rfl⟩ := (mem_image ..).mp hi
exact Set.subset_iUnion (b ∘ f') j
· rintro ⟨s, hs, rfl⟩
constructor
· exact hs.isLindelof_biUnion fun i _ => hb' i
· exact isOpen_biUnion fun i _ => hb.isOpen (Set.mem_range_self _)
def Filter.coLindelof (X : Type*) [TopologicalSpace X] : Filter X :=
--`Filter.coLindelof` is the filter generated by complements to Lindelöf sets.
⨅ (s : Set X) (_ : IsLindelof s), 𝓟 sᶜ
theorem hasBasis_coLindelof : (coLindelof X).HasBasis IsLindelof compl :=
hasBasis_biInf_principal'
(fun s hs t ht =>
⟨s ∪ t, hs.union ht, compl_subset_compl.2 subset_union_left,
compl_subset_compl.2 subset_union_right⟩)
⟨∅, isLindelof_empty⟩
theorem mem_coLindelof : s ∈ coLindelof X ↔ ∃ t, IsLindelof t ∧ tᶜ ⊆ s :=
hasBasis_coLindelof.mem_iff
theorem mem_coLindelof' : s ∈ coLindelof X ↔ ∃ t, IsLindelof t ∧ sᶜ ⊆ t :=
mem_coLindelof.trans <| exists_congr fun _ => and_congr_right fun _ => compl_subset_comm
theorem _root_.IsLindelof.compl_mem_coLindelof (hs : IsLindelof s) : sᶜ ∈ coLindelof X :=
hasBasis_coLindelof.mem_of_mem hs
theorem coLindelof_le_cofinite : coLindelof X ≤ cofinite := fun s hs =>
compl_compl s ▸ hs.isLindelof.compl_mem_coLindelof
theorem Tendsto.isLindelof_insert_range_of_coLindelof {f : X → Y} {y}
(hf : Tendsto f (coLindelof X) (𝓝 y)) (hfc : Continuous f) :
IsLindelof (insert y (range f)) := by
intro l hne _ hle
by_cases hy : ClusterPt y l
· exact ⟨y, Or.inl rfl, hy⟩
simp only [clusterPt_iff, not_forall, ← not_disjoint_iff_nonempty_inter, not_not] at hy
rcases hy with ⟨s, hsy, t, htl, hd⟩
rcases mem_coLindelof.1 (hf hsy) with ⟨K, hKc, hKs⟩
have : f '' K ∈ l := by
filter_upwards [htl, le_principal_iff.1 hle] with y hyt hyf
rcases hyf with (rfl | ⟨x, rfl⟩)
exacts [(hd.le_bot ⟨mem_of_mem_nhds hsy, hyt⟩).elim,
mem_image_of_mem _ (not_not.1 fun hxK => hd.le_bot ⟨hKs hxK, hyt⟩)]
rcases hKc.image hfc (le_principal_iff.2 this) with ⟨y, hy, hyl⟩
exact ⟨y, Or.inr <| image_subset_range _ _ hy, hyl⟩
def Filter.coclosedLindelof (X : Type*) [TopologicalSpace X] : Filter X :=
-- `Filter.coclosedLindelof` is the filter generated by complements to closed Lindelof sets.
⨅ (s : Set X) (_ : IsClosed s) (_ : IsLindelof s), 𝓟 sᶜ
theorem hasBasis_coclosedLindelof :
(Filter.coclosedLindelof X).HasBasis (fun s => IsClosed s ∧ IsLindelof s) compl := by
simp only [Filter.coclosedLindelof, iInf_and']
refine hasBasis_biInf_principal' ?_ ⟨∅, isClosed_empty, isLindelof_empty⟩
rintro s ⟨hs₁, hs₂⟩ t ⟨ht₁, ht₂⟩
exact ⟨s ∪ t, ⟨⟨hs₁.union ht₁, hs₂.union ht₂⟩, compl_subset_compl.2 subset_union_left,
compl_subset_compl.2 subset_union_right⟩⟩
theorem mem_coclosedLindelof : s ∈ coclosedLindelof X ↔
∃ t, IsClosed t ∧ IsLindelof t ∧ tᶜ ⊆ s := by
simp only [hasBasis_coclosedLindelof.mem_iff, and_assoc]
theorem mem_coclosed_Lindelof' : s ∈ coclosedLindelof X ↔
∃ t, IsClosed t ∧ IsLindelof t ∧ sᶜ ⊆ t := by
simp only [mem_coclosedLindelof, compl_subset_comm]
theorem coLindelof_le_coclosedLindelof : coLindelof X ≤ coclosedLindelof X :=
iInf_mono fun _ => le_iInf fun _ => le_rfl
theorem IsLindeof.compl_mem_coclosedLindelof_of_isClosed (hs : IsLindelof s) (hs' : IsClosed s) :
sᶜ ∈ Filter.coclosedLindelof X :=
hasBasis_coclosedLindelof.mem_of_mem ⟨hs', hs⟩
class LindelofSpace (X : Type*) [TopologicalSpace X] : Prop where
isLindelof_univ : IsLindelof (univ : Set X)
instance (priority := 10) Subsingleton.lindelofSpace [Subsingleton X] : LindelofSpace X :=
⟨subsingleton_univ.isLindelof⟩
theorem isLindelof_univ_iff : IsLindelof (univ : Set X) ↔ LindelofSpace X :=
⟨fun h => ⟨h⟩, fun h => h.1⟩
theorem isLindelof_univ [h : LindelofSpace X] : IsLindelof (univ : Set X) :=
h.isLindelof_univ
theorem cluster_point_of_Lindelof [LindelofSpace X] (f : Filter X) [NeBot f]
[CountableInterFilter f] : ∃ x, ClusterPt x f := by
simpa using isLindelof_univ (show f ≤ 𝓟 univ by simp)
theorem LindelofSpace.elim_nhds_subcover [LindelofSpace X] (U : X → Set X) (hU : ∀ x, U x ∈ 𝓝 x) :
∃ t : Set X, t.Countable ∧ ⋃ x ∈ t, U x = univ := by
obtain ⟨t, tc, -, s⟩ := IsLindelof.elim_nhds_subcover isLindelof_univ U fun x _ => hU x
use t, tc
apply top_unique s
theorem lindelofSpace_of_countable_subfamily_closed
(h : ∀ {ι : Type u} (t : ι → Set X), (∀ i, IsClosed (t i)) → ⋂ i, t i = ∅ →
∃ u : Set ι, u.Countable ∧ ⋂ i ∈ u, t i = ∅) :
LindelofSpace X where
isLindelof_univ := isLindelof_of_countable_subfamily_closed fun t => by simpa using h t
theorem IsClosed.isLindelof [LindelofSpace X] (h : IsClosed s) : IsLindelof s :=
isLindelof_univ.of_isClosed_subset h (subset_univ _)
| Mathlib/Topology/Compactness/Lindelof.lean | 497 | 498 | theorem IsCompact.isLindelof (hs : IsCompact s) :
IsLindelof s := by | tauto
|
import Mathlib.Algebra.Group.Commute.Defs
import Mathlib.Algebra.Group.Units
import Mathlib.Algebra.GroupWithZero.Defs
import Mathlib.Algebra.Order.Monoid.Unbundled.Basic
import Mathlib.Tactic.NthRewrite
#align_import algebra.regular.basic from "leanprover-community/mathlib"@"5cd3c25312f210fec96ba1edb2aebfb2ccf2010f"
variable {R : Type*}
section Mul
variable [Mul R]
@[to_additive "An add-left-regular element is an element `c` such that addition
on the left by `c` is injective."]
def IsLeftRegular (c : R) :=
(c * ·).Injective
#align is_left_regular IsLeftRegular
#align is_add_left_regular IsAddLeftRegular
@[to_additive "An add-right-regular element is an element `c` such that addition
on the right by `c` is injective."]
def IsRightRegular (c : R) :=
(· * c).Injective
#align is_right_regular IsRightRegular
#align is_add_right_regular IsAddRightRegular
structure IsAddRegular {R : Type*} [Add R] (c : R) : Prop where
left : IsAddLeftRegular c -- Porting note: It seems like to_additive is misbehaving
right : IsAddRightRegular c
#align is_add_regular IsAddRegular
structure IsRegular (c : R) : Prop where
left : IsLeftRegular c
right : IsRightRegular c
#align is_regular IsRegular
attribute [simp] IsRegular.left IsRegular.right
attribute [to_additive] IsRegular
@[to_additive]
protected theorem MulLECancellable.isLeftRegular [PartialOrder R] {a : R}
(ha : MulLECancellable a) : IsLeftRegular a :=
ha.Injective
#align mul_le_cancellable.is_left_regular MulLECancellable.isLeftRegular
#align add_le_cancellable.is_add_left_regular AddLECancellable.isAddLeftRegular
theorem IsLeftRegular.right_of_commute {a : R}
(ca : ∀ b, Commute a b) (h : IsLeftRegular a) : IsRightRegular a :=
fun x y xy => h <| (ca x).trans <| xy.trans <| (ca y).symm
#align is_left_regular.right_of_commute IsLeftRegular.right_of_commute
| Mathlib/Algebra/Regular/Basic.lean | 91 | 94 | theorem IsRightRegular.left_of_commute {a : R}
(ca : ∀ b, Commute a b) (h : IsRightRegular a) : IsLeftRegular a := by |
simp_rw [@Commute.symm_iff R _ a] at ca
exact fun x y xy => h <| (ca x).trans <| xy.trans <| (ca y).symm
|
import Mathlib.Algebra.Polynomial.Module.AEval
#align_import data.polynomial.module from "leanprover-community/mathlib"@"63417e01fbc711beaf25fa73b6edb395c0cfddd0"
universe u v
open Polynomial BigOperators
@[nolint unusedArguments]
def PolynomialModule (R M : Type*) [CommRing R] [AddCommGroup M] [Module R M] := ℕ →₀ M
#align polynomial_module PolynomialModule
variable (R M : Type*) [CommRing R] [AddCommGroup M] [Module R M] (I : Ideal R)
-- Porting note: stated instead of deriving
noncomputable instance : Inhabited (PolynomialModule R M) := Finsupp.instInhabited
noncomputable instance : AddCommGroup (PolynomialModule R M) := Finsupp.instAddCommGroup
variable {M}
variable {S : Type*} [CommSemiring S] [Algebra S R] [Module S M] [IsScalarTower S R M]
namespace PolynomialModule
@[nolint unusedArguments]
noncomputable instance : Module S (PolynomialModule R M) :=
Finsupp.module ℕ M
instance instFunLike : FunLike (PolynomialModule R M) ℕ M :=
Finsupp.instFunLike
instance : CoeFun (PolynomialModule R M) fun _ => ℕ → M :=
Finsupp.instCoeFun
theorem zero_apply (i : ℕ) : (0 : PolynomialModule R M) i = 0 :=
Finsupp.zero_apply
theorem add_apply (g₁ g₂ : PolynomialModule R M) (a : ℕ) : (g₁ + g₂) a = g₁ a + g₂ a :=
Finsupp.add_apply g₁ g₂ a
noncomputable def single (i : ℕ) : M →+ PolynomialModule R M :=
Finsupp.singleAddHom i
#align polynomial_module.single PolynomialModule.single
theorem single_apply (i : ℕ) (m : M) (n : ℕ) : single R i m n = ite (i = n) m 0 :=
Finsupp.single_apply
#align polynomial_module.single_apply PolynomialModule.single_apply
noncomputable def lsingle (i : ℕ) : M →ₗ[R] PolynomialModule R M :=
Finsupp.lsingle i
#align polynomial_module.lsingle PolynomialModule.lsingle
theorem lsingle_apply (i : ℕ) (m : M) (n : ℕ) : lsingle R i m n = ite (i = n) m 0 :=
Finsupp.single_apply
#align polynomial_module.lsingle_apply PolynomialModule.lsingle_apply
theorem single_smul (i : ℕ) (r : R) (m : M) : single R i (r • m) = r • single R i m :=
(lsingle R i).map_smul r m
#align polynomial_module.single_smul PolynomialModule.single_smul
variable {R}
theorem induction_linear {P : PolynomialModule R M → Prop} (f : PolynomialModule R M) (h0 : P 0)
(hadd : ∀ f g, P f → P g → P (f + g)) (hsingle : ∀ a b, P (single R a b)) : P f :=
Finsupp.induction_linear f h0 hadd hsingle
#align polynomial_module.induction_linear PolynomialModule.induction_linear
noncomputable instance polynomialModule : Module R[X] (PolynomialModule R M) :=
inferInstanceAs (Module R[X] (Module.AEval' (Finsupp.lmapDomain M R Nat.succ)))
#align polynomial_module.polynomial_module PolynomialModule.polynomialModule
lemma smul_def (f : R[X]) (m : PolynomialModule R M) :
f • m = aeval (Finsupp.lmapDomain M R Nat.succ) f m := by
rfl
instance (M : Type u) [AddCommGroup M] [Module R M] [Module S M] [IsScalarTower S R M] :
IsScalarTower S R (PolynomialModule R M) :=
Finsupp.isScalarTower _ _
instance isScalarTower' (M : Type u) [AddCommGroup M] [Module R M] [Module S M]
[IsScalarTower S R M] : IsScalarTower S R[X] (PolynomialModule R M) := by
haveI : IsScalarTower R R[X] (PolynomialModule R M) :=
inferInstanceAs <| IsScalarTower R R[X] <| Module.AEval' <| Finsupp.lmapDomain M R Nat.succ
constructor
intro x y z
rw [← @IsScalarTower.algebraMap_smul S R, ← @IsScalarTower.algebraMap_smul S R, smul_assoc]
#align polynomial_module.is_scalar_tower' PolynomialModule.isScalarTower'
@[simp]
theorem monomial_smul_single (i : ℕ) (r : R) (j : ℕ) (m : M) :
monomial i r • single R j m = single R (i + j) (r • m) := by
simp only [LinearMap.mul_apply, Polynomial.aeval_monomial, LinearMap.pow_apply,
Module.algebraMap_end_apply, smul_def]
induction i generalizing r j m with
| zero =>
rw [Function.iterate_zero, zero_add]
exact Finsupp.smul_single r j m
| succ n hn =>
rw [Function.iterate_succ, Function.comp_apply, add_assoc, ← hn]
congr 2
rw [Nat.one_add]
exact Finsupp.mapDomain_single
#align polynomial_module.monomial_smul_single PolynomialModule.monomial_smul_single
@[simp]
theorem monomial_smul_apply (i : ℕ) (r : R) (g : PolynomialModule R M) (n : ℕ) :
(monomial i r • g) n = ite (i ≤ n) (r • g (n - i)) 0 := by
induction' g using PolynomialModule.induction_linear with p q hp hq
· simp only [smul_zero, zero_apply, ite_self]
· simp only [smul_add, add_apply, hp, hq]
split_ifs
exacts [rfl, zero_add 0]
· rw [monomial_smul_single, single_apply, single_apply, smul_ite, smul_zero, ← ite_and]
congr
rw [eq_iff_iff]
constructor
· rintro rfl
simp
· rintro ⟨e, rfl⟩
rw [add_comm, tsub_add_cancel_of_le e]
#align polynomial_module.monomial_smul_apply PolynomialModule.monomial_smul_apply
@[simp]
theorem smul_single_apply (i : ℕ) (f : R[X]) (m : M) (n : ℕ) :
(f • single R i m) n = ite (i ≤ n) (f.coeff (n - i) • m) 0 := by
induction' f using Polynomial.induction_on' with p q hp hq
· rw [add_smul, Finsupp.add_apply, hp, hq, coeff_add, add_smul]
split_ifs
exacts [rfl, zero_add 0]
· rw [monomial_smul_single, single_apply, coeff_monomial, ite_smul, zero_smul]
by_cases h : i ≤ n
· simp_rw [eq_tsub_iff_add_eq_of_le h, if_pos h]
· rw [if_neg h, ite_eq_right_iff]
intro e
exfalso
linarith
#align polynomial_module.smul_single_apply PolynomialModule.smul_single_apply
theorem smul_apply (f : R[X]) (g : PolynomialModule R M) (n : ℕ) :
(f • g) n = ∑ x ∈ Finset.antidiagonal n, f.coeff x.1 • g x.2 := by
induction' f using Polynomial.induction_on' with p q hp hq f_n f_a
· rw [add_smul, Finsupp.add_apply, hp, hq, ← Finset.sum_add_distrib]
congr
ext
rw [coeff_add, add_smul]
· rw [Finset.Nat.sum_antidiagonal_eq_sum_range_succ fun i j => (monomial f_n f_a).coeff i • g j,
monomial_smul_apply]
simp_rw [Polynomial.coeff_monomial, ← Finset.mem_range_succ_iff]
rw [← Finset.sum_ite_eq (Finset.range (Nat.succ n)) f_n (fun x => f_a • g (n - x))]
congr
ext x
split_ifs
exacts [rfl, (zero_smul R _).symm]
#align polynomial_module.smul_apply PolynomialModule.smul_apply
noncomputable def equivPolynomialSelf : PolynomialModule R R ≃ₗ[R[X]] R[X] :=
{ (Polynomial.toFinsuppIso R).symm with
map_smul' := fun r x => by
dsimp
rw [← RingEquiv.coe_toEquiv_symm, RingEquiv.coe_toEquiv]
induction' x using induction_linear with _ _ hp hq n a
· rw [smul_zero, map_zero, mul_zero]
· rw [smul_add, map_add, map_add, mul_add, hp, hq]
· ext i
simp only [coeff_ofFinsupp, smul_single_apply, toFinsuppIso_symm_apply, coeff_ofFinsupp,
single_apply, ge_iff_le, smul_eq_mul, Polynomial.coeff_mul, mul_ite, mul_zero]
split_ifs with hn
· rw [Finset.sum_eq_single (i - n, n)]
· simp only [ite_true]
· rintro ⟨p, q⟩ hpq1 hpq2
rw [Finset.mem_antidiagonal] at hpq1
split_ifs with H
· dsimp at H
exfalso
apply hpq2
rw [← hpq1, H]
simp only [add_le_iff_nonpos_left, nonpos_iff_eq_zero, add_tsub_cancel_right]
· rfl
· intro H
exfalso
apply H
rw [Finset.mem_antidiagonal, tsub_add_cancel_of_le hn]
· symm
rw [Finset.sum_ite_of_false, Finset.sum_const_zero]
simp_rw [Finset.mem_antidiagonal]
intro x hx
contrapose! hn
rw [add_comm, ← hn] at hx
exact Nat.le.intro hx }
#align polynomial_module.equiv_polynomial_self PolynomialModule.equivPolynomialSelf
noncomputable def equivPolynomial {S : Type*} [CommRing S] [Algebra R S] :
PolynomialModule R S ≃ₗ[R] S[X] :=
{ (Polynomial.toFinsuppIso S).symm with map_smul' := fun _ _ => rfl }
#align polynomial_module.equiv_polynomial PolynomialModule.equivPolynomial
variable (R' : Type*) {M' : Type*} [CommRing R'] [AddCommGroup M'] [Module R' M']
variable [Algebra R R'] [Module R M'] [IsScalarTower R R' M']
noncomputable def map (f : M →ₗ[R] M') : PolynomialModule R M →ₗ[R] PolynomialModule R' M' :=
Finsupp.mapRange.linearMap f
#align polynomial_module.map PolynomialModule.map
@[simp]
theorem map_single (f : M →ₗ[R] M') (i : ℕ) (m : M) : map R' f (single R i m) = single R' i (f m) :=
Finsupp.mapRange_single (hf := f.map_zero)
#align polynomial_module.map_single PolynomialModule.map_single
theorem map_smul (f : M →ₗ[R] M') (p : R[X]) (q : PolynomialModule R M) :
map R' f (p • q) = p.map (algebraMap R R') • map R' f q := by
apply induction_linear q
· rw [smul_zero, map_zero, smul_zero]
· intro f g e₁ e₂
rw [smul_add, map_add, e₁, e₂, map_add, smul_add]
intro i m
induction' p using Polynomial.induction_on' with _ _ e₁ e₂
· rw [add_smul, map_add, e₁, e₂, Polynomial.map_add, add_smul]
· rw [monomial_smul_single, map_single, Polynomial.map_monomial, map_single, monomial_smul_single,
f.map_smul, algebraMap_smul]
#align polynomial_module.map_smul PolynomialModule.map_smul
@[simps! (config := .lemmasOnly)]
def eval (r : R) : PolynomialModule R M →ₗ[R] M where
toFun p := p.sum fun i m => r ^ i • m
map_add' x y := Finsupp.sum_add_index' (fun _ => smul_zero _) fun _ _ _ => smul_add _ _ _
map_smul' s m := by
refine (Finsupp.sum_smul_index' ?_).trans ?_
· exact fun i => smul_zero _
· simp_rw [RingHom.id_apply, Finsupp.smul_sum]
congr
ext i c
rw [smul_comm]
#align polynomial_module.eval PolynomialModule.eval
@[simp]
theorem eval_single (r : R) (i : ℕ) (m : M) : eval r (single R i m) = r ^ i • m :=
Finsupp.sum_single_index (smul_zero _)
#align polynomial_module.eval_single PolynomialModule.eval_single
@[simp]
theorem eval_lsingle (r : R) (i : ℕ) (m : M) : eval r (lsingle R i m) = r ^ i • m :=
eval_single r i m
#align polynomial_module.eval_lsingle PolynomialModule.eval_lsingle
theorem eval_smul (p : R[X]) (q : PolynomialModule R M) (r : R) :
eval r (p • q) = p.eval r • eval r q := by
apply induction_linear q
· rw [smul_zero, map_zero, smul_zero]
· intro f g e₁ e₂
rw [smul_add, map_add, e₁, e₂, map_add, smul_add]
intro i m
induction' p using Polynomial.induction_on' with _ _ e₁ e₂
· rw [add_smul, map_add, Polynomial.eval_add, e₁, e₂, add_smul]
· rw [monomial_smul_single, eval_single, Polynomial.eval_monomial, eval_single, smul_comm, ←
smul_smul, pow_add, mul_smul]
#align polynomial_module.eval_smul PolynomialModule.eval_smul
@[simp]
| Mathlib/Algebra/Polynomial/Module/Basic.lean | 296 | 303 | theorem eval_map (f : M →ₗ[R] M') (q : PolynomialModule R M) (r : R) :
eval (algebraMap R R' r) (map R' f q) = f (eval r q) := by |
apply induction_linear q
· simp_rw [map_zero]
· intro f g e₁ e₂
simp_rw [map_add, e₁, e₂]
· intro i m
rw [map_single, eval_single, eval_single, f.map_smul, ← map_pow, algebraMap_smul]
|
import Mathlib.MeasureTheory.Function.ConditionalExpectation.Indicator
import Mathlib.MeasureTheory.Function.UniformIntegrable
import Mathlib.MeasureTheory.Decomposition.RadonNikodym
#align_import measure_theory.function.conditional_expectation.real from "leanprover-community/mathlib"@"b2ff9a3d7a15fd5b0f060b135421d6a89a999c2f"
noncomputable section
open TopologicalSpace MeasureTheory.Lp Filter ContinuousLinearMap
open scoped NNReal ENNReal Topology MeasureTheory
namespace MeasureTheory
variable {α : Type*} {m m0 : MeasurableSpace α} {μ : Measure α}
theorem rnDeriv_ae_eq_condexp {hm : m ≤ m0} [hμm : SigmaFinite (μ.trim hm)] {f : α → ℝ}
(hf : Integrable f μ) :
SignedMeasure.rnDeriv ((μ.withDensityᵥ f).trim hm) (μ.trim hm) =ᵐ[μ] μ[f|m] := by
refine ae_eq_condexp_of_forall_setIntegral_eq hm hf ?_ ?_ ?_
· exact fun _ _ _ => (integrable_of_integrable_trim hm
(SignedMeasure.integrable_rnDeriv ((μ.withDensityᵥ f).trim hm) (μ.trim hm))).integrableOn
· intro s hs _
conv_rhs => rw [← hf.withDensityᵥ_trim_eq_integral hm hs,
← SignedMeasure.withDensityᵥ_rnDeriv_eq ((μ.withDensityᵥ f).trim hm) (μ.trim hm)
(hf.withDensityᵥ_trim_absolutelyContinuous hm)]
rw [withDensityᵥ_apply
(SignedMeasure.integrable_rnDeriv ((μ.withDensityᵥ f).trim hm) (μ.trim hm)) hs,
← setIntegral_trim hm _ hs]
exact (SignedMeasure.measurable_rnDeriv _ _).stronglyMeasurable
· exact (SignedMeasure.measurable_rnDeriv _ _).stronglyMeasurable.aeStronglyMeasurable'
#align measure_theory.rn_deriv_ae_eq_condexp MeasureTheory.rnDeriv_ae_eq_condexp
-- TODO: the following couple of lemmas should be generalized and proved using Jensen's inequality
-- for the conditional expectation (not in mathlib yet) .
theorem snorm_one_condexp_le_snorm (f : α → ℝ) : snorm (μ[f|m]) 1 μ ≤ snorm f 1 μ := by
by_cases hf : Integrable f μ
swap; · rw [condexp_undef hf, snorm_zero]; exact zero_le _
by_cases hm : m ≤ m0
swap; · rw [condexp_of_not_le hm, snorm_zero]; exact zero_le _
by_cases hsig : SigmaFinite (μ.trim hm)
swap; · rw [condexp_of_not_sigmaFinite hm hsig, snorm_zero]; exact zero_le _
calc
snorm (μ[f|m]) 1 μ ≤ snorm (μ[(|f|)|m]) 1 μ := by
refine snorm_mono_ae ?_
filter_upwards [condexp_mono hf hf.abs
(ae_of_all μ (fun x => le_abs_self (f x) : ∀ x, f x ≤ |f x|)),
EventuallyLE.trans (condexp_neg f).symm.le
(condexp_mono hf.neg hf.abs
(ae_of_all μ (fun x => neg_le_abs (f x): ∀ x, -f x ≤ |f x|)))] with x hx₁ hx₂
exact abs_le_abs hx₁ hx₂
_ = snorm f 1 μ := by
rw [snorm_one_eq_lintegral_nnnorm, snorm_one_eq_lintegral_nnnorm, ←
ENNReal.toReal_eq_toReal (ne_of_lt integrable_condexp.2) (ne_of_lt hf.2), ←
integral_norm_eq_lintegral_nnnorm
(stronglyMeasurable_condexp.mono hm).aestronglyMeasurable,
← integral_norm_eq_lintegral_nnnorm hf.1]
simp_rw [Real.norm_eq_abs]
rw [← integral_condexp hm hf.abs]
refine integral_congr_ae ?_
have : 0 ≤ᵐ[μ] μ[(|f|)|m] := by
rw [← condexp_zero]
exact condexp_mono (integrable_zero _ _ _) hf.abs
(ae_of_all μ (fun x => abs_nonneg (f x) : ∀ x, 0 ≤ |f x|))
filter_upwards [this] with x hx
exact abs_eq_self.2 hx
#align measure_theory.snorm_one_condexp_le_snorm MeasureTheory.snorm_one_condexp_le_snorm
| Mathlib/MeasureTheory/Function/ConditionalExpectation/Real.lean | 92 | 113 | theorem integral_abs_condexp_le (f : α → ℝ) : ∫ x, |(μ[f|m]) x| ∂μ ≤ ∫ x, |f x| ∂μ := by |
by_cases hm : m ≤ m0
swap
· simp_rw [condexp_of_not_le hm, Pi.zero_apply, abs_zero, integral_zero]
positivity
by_cases hfint : Integrable f μ
swap
· simp only [condexp_undef hfint, Pi.zero_apply, abs_zero, integral_const, Algebra.id.smul_eq_mul,
mul_zero]
positivity
rw [integral_eq_lintegral_of_nonneg_ae, integral_eq_lintegral_of_nonneg_ae]
· rw [ENNReal.toReal_le_toReal] <;> simp_rw [← Real.norm_eq_abs, ofReal_norm_eq_coe_nnnorm]
· rw [← snorm_one_eq_lintegral_nnnorm, ← snorm_one_eq_lintegral_nnnorm]
exact snorm_one_condexp_le_snorm _
· exact integrable_condexp.2.ne
· exact hfint.2.ne
· filter_upwards with x using abs_nonneg _
· simp_rw [← Real.norm_eq_abs]
exact hfint.1.norm
· filter_upwards with x using abs_nonneg _
· simp_rw [← Real.norm_eq_abs]
exact (stronglyMeasurable_condexp.mono hm).aestronglyMeasurable.norm
|
import Mathlib.Algebra.Polynomial.Expand
import Mathlib.Algebra.Polynomial.Splits
import Mathlib.Algebra.Squarefree.Basic
import Mathlib.FieldTheory.Minpoly.Field
import Mathlib.RingTheory.PowerBasis
#align_import field_theory.separable from "leanprover-community/mathlib"@"92ca63f0fb391a9ca5f22d2409a6080e786d99f7"
universe u v w
open scoped Classical
open Polynomial Finset
namespace Polynomial
section CommSemiring
variable {R : Type u} [CommSemiring R] {S : Type v} [CommSemiring S]
def Separable (f : R[X]) : Prop :=
IsCoprime f (derivative f)
#align polynomial.separable Polynomial.Separable
theorem separable_def (f : R[X]) : f.Separable ↔ IsCoprime f (derivative f) :=
Iff.rfl
#align polynomial.separable_def Polynomial.separable_def
theorem separable_def' (f : R[X]) : f.Separable ↔ ∃ a b : R[X], a * f + b * (derivative f) = 1 :=
Iff.rfl
#align polynomial.separable_def' Polynomial.separable_def'
| Mathlib/FieldTheory/Separable.lean | 52 | 54 | theorem not_separable_zero [Nontrivial R] : ¬Separable (0 : R[X]) := by |
rintro ⟨x, y, h⟩
simp only [derivative_zero, mul_zero, add_zero, zero_ne_one] at h
|
import Mathlib.Data.Finsupp.Multiset
import Mathlib.Data.Nat.GCD.BigOperators
import Mathlib.Data.Nat.PrimeFin
import Mathlib.NumberTheory.Padics.PadicVal
import Mathlib.Order.Interval.Finset.Nat
#align_import data.nat.factorization.basic from "leanprover-community/mathlib"@"f694c7dead66f5d4c80f446c796a5aad14707f0e"
-- Workaround for lean4#2038
attribute [-instance] instBEqNat
open Nat Finset List Finsupp
namespace Nat
variable {a b m n p : ℕ}
def factorization (n : ℕ) : ℕ →₀ ℕ where
support := n.primeFactors
toFun p := if p.Prime then padicValNat p n else 0
mem_support_toFun := by simp [not_or]; aesop
#align nat.factorization Nat.factorization
@[simp] lemma support_factorization (n : ℕ) : (factorization n).support = n.primeFactors := rfl
theorem factorization_def (n : ℕ) {p : ℕ} (pp : p.Prime) : n.factorization p = padicValNat p n := by
simpa [factorization] using absurd pp
#align nat.factorization_def Nat.factorization_def
@[simp]
theorem factors_count_eq {n p : ℕ} : n.factors.count p = n.factorization p := by
rcases n.eq_zero_or_pos with (rfl | hn0)
· simp [factorization, count]
if pp : p.Prime then ?_ else
rw [count_eq_zero_of_not_mem (mt prime_of_mem_factors pp)]
simp [factorization, pp]
simp only [factorization_def _ pp]
apply _root_.le_antisymm
· rw [le_padicValNat_iff_replicate_subperm_factors pp hn0.ne']
exact List.le_count_iff_replicate_sublist.mp le_rfl |>.subperm
· rw [← lt_add_one_iff, lt_iff_not_ge, ge_iff_le,
le_padicValNat_iff_replicate_subperm_factors pp hn0.ne']
intro h
have := h.count_le p
simp at this
#align nat.factors_count_eq Nat.factors_count_eq
theorem factorization_eq_factors_multiset (n : ℕ) :
n.factorization = Multiset.toFinsupp (n.factors : Multiset ℕ) := by
ext p
simp
#align nat.factorization_eq_factors_multiset Nat.factorization_eq_factors_multiset
theorem multiplicity_eq_factorization {n p : ℕ} (pp : p.Prime) (hn : n ≠ 0) :
multiplicity p n = n.factorization p := by
simp [factorization, pp, padicValNat_def' pp.ne_one hn.bot_lt]
#align nat.multiplicity_eq_factorization Nat.multiplicity_eq_factorization
@[simp]
theorem factorization_prod_pow_eq_self {n : ℕ} (hn : n ≠ 0) : n.factorization.prod (· ^ ·) = n := by
rw [factorization_eq_factors_multiset n]
simp only [← prod_toMultiset, factorization, Multiset.prod_coe, Multiset.toFinsupp_toMultiset]
exact prod_factors hn
#align nat.factorization_prod_pow_eq_self Nat.factorization_prod_pow_eq_self
theorem eq_of_factorization_eq {a b : ℕ} (ha : a ≠ 0) (hb : b ≠ 0)
(h : ∀ p : ℕ, a.factorization p = b.factorization p) : a = b :=
eq_of_perm_factors ha hb (by simpa only [List.perm_iff_count, factors_count_eq] using h)
#align nat.eq_of_factorization_eq Nat.eq_of_factorization_eq
theorem factorization_inj : Set.InjOn factorization { x : ℕ | x ≠ 0 } := fun a ha b hb h =>
eq_of_factorization_eq ha hb fun p => by simp [h]
#align nat.factorization_inj Nat.factorization_inj
@[simp]
theorem factorization_zero : factorization 0 = 0 := by ext; simp [factorization]
#align nat.factorization_zero Nat.factorization_zero
@[simp]
theorem factorization_one : factorization 1 = 0 := by ext; simp [factorization]
#align nat.factorization_one Nat.factorization_one
#noalign nat.support_factorization
#align nat.factor_iff_mem_factorization Nat.mem_primeFactors_iff_mem_factors
#align nat.prime_of_mem_factorization Nat.prime_of_mem_primeFactors
#align nat.pos_of_mem_factorization Nat.pos_of_mem_primeFactors
#align nat.le_of_mem_factorization Nat.le_of_mem_primeFactors
theorem factorization_eq_zero_iff (n p : ℕ) :
n.factorization p = 0 ↔ ¬p.Prime ∨ ¬p ∣ n ∨ n = 0 := by
simp_rw [← not_mem_support_iff, support_factorization, mem_primeFactors, not_and_or, not_ne_iff]
#align nat.factorization_eq_zero_iff Nat.factorization_eq_zero_iff
@[simp]
theorem factorization_eq_zero_of_non_prime (n : ℕ) {p : ℕ} (hp : ¬p.Prime) :
n.factorization p = 0 := by simp [factorization_eq_zero_iff, hp]
#align nat.factorization_eq_zero_of_non_prime Nat.factorization_eq_zero_of_non_prime
theorem factorization_eq_zero_of_not_dvd {n p : ℕ} (h : ¬p ∣ n) : n.factorization p = 0 := by
simp [factorization_eq_zero_iff, h]
#align nat.factorization_eq_zero_of_not_dvd Nat.factorization_eq_zero_of_not_dvd
theorem factorization_eq_zero_of_lt {n p : ℕ} (h : n < p) : n.factorization p = 0 :=
Finsupp.not_mem_support_iff.mp (mt le_of_mem_primeFactors (not_le_of_lt h))
#align nat.factorization_eq_zero_of_lt Nat.factorization_eq_zero_of_lt
@[simp]
theorem factorization_zero_right (n : ℕ) : n.factorization 0 = 0 :=
factorization_eq_zero_of_non_prime _ not_prime_zero
#align nat.factorization_zero_right Nat.factorization_zero_right
@[simp]
theorem factorization_one_right (n : ℕ) : n.factorization 1 = 0 :=
factorization_eq_zero_of_non_prime _ not_prime_one
#align nat.factorization_one_right Nat.factorization_one_right
theorem dvd_of_factorization_pos {n p : ℕ} (hn : n.factorization p ≠ 0) : p ∣ n :=
dvd_of_mem_factors <| mem_primeFactors_iff_mem_factors.1 <| mem_support_iff.2 hn
#align nat.dvd_of_factorization_pos Nat.dvd_of_factorization_pos
theorem Prime.factorization_pos_of_dvd {n p : ℕ} (hp : p.Prime) (hn : n ≠ 0) (h : p ∣ n) :
0 < n.factorization p := by
rwa [← factors_count_eq, count_pos_iff_mem, mem_factors_iff_dvd hn hp]
#align nat.prime.factorization_pos_of_dvd Nat.Prime.factorization_pos_of_dvd
theorem factorization_eq_zero_of_remainder {p r : ℕ} (i : ℕ) (hr : ¬p ∣ r) :
(p * i + r).factorization p = 0 := by
apply factorization_eq_zero_of_not_dvd
rwa [← Nat.dvd_add_iff_right (Dvd.intro i rfl)]
#align nat.factorization_eq_zero_of_remainder Nat.factorization_eq_zero_of_remainder
theorem factorization_eq_zero_iff_remainder {p r : ℕ} (i : ℕ) (pp : p.Prime) (hr0 : r ≠ 0) :
¬p ∣ r ↔ (p * i + r).factorization p = 0 := by
refine ⟨factorization_eq_zero_of_remainder i, fun h => ?_⟩
rw [factorization_eq_zero_iff] at h
contrapose! h
refine ⟨pp, ?_, ?_⟩
· rwa [← Nat.dvd_add_iff_right (dvd_mul_right p i)]
· contrapose! hr0
exact (add_eq_zero_iff.mp hr0).2
#align nat.factorization_eq_zero_iff_remainder Nat.factorization_eq_zero_iff_remainder
theorem factorization_eq_zero_iff' (n : ℕ) : n.factorization = 0 ↔ n = 0 ∨ n = 1 := by
rw [factorization_eq_factors_multiset n]
simp [factorization, AddEquiv.map_eq_zero_iff, Multiset.coe_eq_zero]
#align nat.factorization_eq_zero_iff' Nat.factorization_eq_zero_iff'
@[simp]
theorem factorization_mul {a b : ℕ} (ha : a ≠ 0) (hb : b ≠ 0) :
(a * b).factorization = a.factorization + b.factorization := by
ext p
simp only [add_apply, ← factors_count_eq, perm_iff_count.mp (perm_factors_mul ha hb) p,
count_append]
#align nat.factorization_mul Nat.factorization_mul
#align nat.factorization_mul_support Nat.primeFactors_mul
lemma prod_factorization_eq_prod_primeFactors {β : Type*} [CommMonoid β] (f : ℕ → ℕ → β) :
n.factorization.prod f = ∏ p ∈ n.primeFactors, f p (n.factorization p) := rfl
#align nat.prod_factorization_eq_prod_factors Nat.prod_factorization_eq_prod_primeFactors
lemma prod_primeFactors_prod_factorization {β : Type*} [CommMonoid β] (f : ℕ → β) :
∏ p ∈ n.primeFactors, f p = n.factorization.prod (fun p _ ↦ f p) := rfl
theorem factorization_prod {α : Type*} {S : Finset α} {g : α → ℕ} (hS : ∀ x ∈ S, g x ≠ 0) :
(S.prod g).factorization = S.sum fun x => (g x).factorization := by
classical
ext p
refine Finset.induction_on' S ?_ ?_
· simp
· intro x T hxS hTS hxT IH
have hT : T.prod g ≠ 0 := prod_ne_zero_iff.mpr fun x hx => hS x (hTS hx)
simp [prod_insert hxT, sum_insert hxT, ← IH, factorization_mul (hS x hxS) hT]
#align nat.factorization_prod Nat.factorization_prod
@[simp]
theorem factorization_pow (n k : ℕ) : factorization (n ^ k) = k • n.factorization := by
induction' k with k ih; · simp
rcases eq_or_ne n 0 with (rfl | hn)
· simp
rw [Nat.pow_succ, mul_comm, factorization_mul hn (pow_ne_zero _ hn), ih,
add_smul, one_smul, add_comm]
#align nat.factorization_pow Nat.factorization_pow
@[simp]
protected theorem Prime.factorization {p : ℕ} (hp : Prime p) : p.factorization = single p 1 := by
ext q
rw [← factors_count_eq, factors_prime hp, single_apply, count_singleton', if_congr eq_comm] <;>
rfl
#align nat.prime.factorization Nat.Prime.factorization
@[simp]
theorem Prime.factorization_self {p : ℕ} (hp : Prime p) : p.factorization p = 1 := by simp [hp]
#align nat.prime.factorization_self Nat.Prime.factorization_self
theorem Prime.factorization_pow {p k : ℕ} (hp : Prime p) : (p ^ k).factorization = single p k := by
simp [hp]
#align nat.prime.factorization_pow Nat.Prime.factorization_pow
theorem eq_pow_of_factorization_eq_single {n p k : ℕ} (hn : n ≠ 0)
(h : n.factorization = Finsupp.single p k) : n = p ^ k := by
-- Porting note: explicitly added `Finsupp.prod_single_index`
rw [← Nat.factorization_prod_pow_eq_self hn, h, Finsupp.prod_single_index]
simp
#align nat.eq_pow_of_factorization_eq_single Nat.eq_pow_of_factorization_eq_single
theorem Prime.eq_of_factorization_pos {p q : ℕ} (hp : Prime p) (h : p.factorization q ≠ 0) :
p = q := by simpa [hp.factorization, single_apply] using h
#align nat.prime.eq_of_factorization_pos Nat.Prime.eq_of_factorization_pos
theorem prod_pow_factorization_eq_self {f : ℕ →₀ ℕ} (hf : ∀ p : ℕ, p ∈ f.support → Prime p) :
(f.prod (· ^ ·)).factorization = f := by
have h : ∀ x : ℕ, x ∈ f.support → x ^ f x ≠ 0 := fun p hp =>
pow_ne_zero _ (Prime.ne_zero (hf p hp))
simp only [Finsupp.prod, factorization_prod h]
conv =>
rhs
rw [(sum_single f).symm]
exact sum_congr rfl fun p hp => Prime.factorization_pow (hf p hp)
#align nat.prod_pow_factorization_eq_self Nat.prod_pow_factorization_eq_self
theorem eq_factorization_iff {n : ℕ} {f : ℕ →₀ ℕ} (hn : n ≠ 0) (hf : ∀ p ∈ f.support, Prime p) :
f = n.factorization ↔ f.prod (· ^ ·) = n :=
⟨fun h => by rw [h, factorization_prod_pow_eq_self hn], fun h => by
rw [← h, prod_pow_factorization_eq_self hf]⟩
#align nat.eq_factorization_iff Nat.eq_factorization_iff
def factorizationEquiv : ℕ+ ≃ { f : ℕ →₀ ℕ | ∀ p ∈ f.support, Prime p } where
toFun := fun ⟨n, _⟩ => ⟨n.factorization, fun _ => prime_of_mem_primeFactors⟩
invFun := fun ⟨f, hf⟩ =>
⟨f.prod _, prod_pow_pos_of_zero_not_mem_support fun H => not_prime_zero (hf 0 H)⟩
left_inv := fun ⟨_, hx⟩ => Subtype.ext <| factorization_prod_pow_eq_self hx.ne.symm
right_inv := fun ⟨_, hf⟩ => Subtype.ext <| prod_pow_factorization_eq_self hf
#align nat.factorization_equiv Nat.factorizationEquiv
theorem factorizationEquiv_apply (n : ℕ+) : (factorizationEquiv n).1 = n.1.factorization := by
cases n
rfl
#align nat.factorization_equiv_apply Nat.factorizationEquiv_apply
theorem factorizationEquiv_inv_apply {f : ℕ →₀ ℕ} (hf : ∀ p ∈ f.support, Prime p) :
(factorizationEquiv.symm ⟨f, hf⟩).1 = f.prod (· ^ ·) :=
rfl
#align nat.factorization_equiv_inv_apply Nat.factorizationEquiv_inv_apply
-- Porting note: Lean 4 thinks we need `HPow` without this
set_option quotPrecheck false in
notation "ord_proj[" p "] " n:arg => p ^ Nat.factorization n p
notation "ord_compl[" p "] " n:arg => n / ord_proj[p] n
@[simp]
| Mathlib/Data/Nat/Factorization/Basic.lean | 331 | 332 | theorem ord_proj_of_not_prime (n p : ℕ) (hp : ¬p.Prime) : ord_proj[p] n = 1 := by |
simp [factorization_eq_zero_of_non_prime n hp]
|
import Mathlib.Combinatorics.SimpleGraph.Finite
import Mathlib.Data.Finset.Sym
import Mathlib.Data.Matrix.Basic
#align_import combinatorics.simple_graph.inc_matrix from "leanprover-community/mathlib"@"bb168510ef455e9280a152e7f31673cabd3d7496"
open Finset Matrix SimpleGraph Sym2
open Matrix
namespace SimpleGraph
variable (R : Type*) {α : Type*} (G : SimpleGraph α)
noncomputable def incMatrix [Zero R] [One R] : Matrix α (Sym2 α) R := fun a =>
(G.incidenceSet a).indicator 1
#align simple_graph.inc_matrix SimpleGraph.incMatrix
variable {R}
theorem incMatrix_apply [Zero R] [One R] {a : α} {e : Sym2 α} :
G.incMatrix R a e = (G.incidenceSet a).indicator 1 e :=
rfl
#align simple_graph.inc_matrix_apply SimpleGraph.incMatrix_apply
theorem incMatrix_apply' [Zero R] [One R] [DecidableEq α] [DecidableRel G.Adj] {a : α}
{e : Sym2 α} : G.incMatrix R a e = if e ∈ G.incidenceSet a then 1 else 0 := by
unfold incMatrix Set.indicator
convert rfl
#align simple_graph.inc_matrix_apply' SimpleGraph.incMatrix_apply'
section MulZeroOneClass
variable [MulZeroOneClass R] {a b : α} {e : Sym2 α}
theorem incMatrix_apply_mul_incMatrix_apply : G.incMatrix R a e * G.incMatrix R b e =
(G.incidenceSet a ∩ G.incidenceSet b).indicator 1 e := by
classical simp only [incMatrix, Set.indicator_apply, ite_zero_mul_ite_zero, Pi.one_apply, mul_one,
Set.mem_inter_iff]
#align simple_graph.inc_matrix_apply_mul_inc_matrix_apply SimpleGraph.incMatrix_apply_mul_incMatrix_apply
theorem incMatrix_apply_mul_incMatrix_apply_of_not_adj (hab : a ≠ b) (h : ¬G.Adj a b) :
G.incMatrix R a e * G.incMatrix R b e = 0 := by
rw [incMatrix_apply_mul_incMatrix_apply, Set.indicator_of_not_mem]
rw [G.incidenceSet_inter_incidenceSet_of_not_adj h hab]
exact Set.not_mem_empty e
#align simple_graph.inc_matrix_apply_mul_inc_matrix_apply_of_not_adj SimpleGraph.incMatrix_apply_mul_incMatrix_apply_of_not_adj
| Mathlib/Combinatorics/SimpleGraph/IncMatrix.lean | 92 | 93 | theorem incMatrix_of_not_mem_incidenceSet (h : e ∉ G.incidenceSet a) : G.incMatrix R a e = 0 := by |
rw [incMatrix_apply, Set.indicator_of_not_mem h]
|
import Mathlib.Analysis.Calculus.ContDiff.Basic
import Mathlib.Data.Finset.Sym
import Mathlib.Data.Nat.Choose.Cast
import Mathlib.Data.Nat.Choose.Multinomial
#align_import analysis.calculus.cont_diff from "leanprover-community/mathlib"@"3bce8d800a6f2b8f63fe1e588fd76a9ff4adcebe"
noncomputable section
open scoped Classical NNReal Nat
universe u uD uE uF uG
open Set Fin Filter Function
variable {𝕜 : Type*} [NontriviallyNormedField 𝕜] {D : Type uD} [NormedAddCommGroup D]
[NormedSpace 𝕜 D] {E : Type uE} [NormedAddCommGroup E] [NormedSpace 𝕜 E] {F : Type uF}
[NormedAddCommGroup F] [NormedSpace 𝕜 F] {G : Type uG} [NormedAddCommGroup G] [NormedSpace 𝕜 G]
{s s₁ t u : Set E}
theorem ContinuousLinearMap.norm_iteratedFDerivWithin_le_of_bilinear_aux {Du Eu Fu Gu : Type u}
[NormedAddCommGroup Du] [NormedSpace 𝕜 Du] [NormedAddCommGroup Eu] [NormedSpace 𝕜 Eu]
[NormedAddCommGroup Fu] [NormedSpace 𝕜 Fu] [NormedAddCommGroup Gu] [NormedSpace 𝕜 Gu]
(B : Eu →L[𝕜] Fu →L[𝕜] Gu) {f : Du → Eu} {g : Du → Fu} {n : ℕ} {s : Set Du} {x : Du}
(hf : ContDiffOn 𝕜 n f s) (hg : ContDiffOn 𝕜 n g s) (hs : UniqueDiffOn 𝕜 s) (hx : x ∈ s) :
‖iteratedFDerivWithin 𝕜 n (fun y => B (f y) (g y)) s x‖ ≤
‖B‖ * ∑ i ∈ Finset.range (n + 1), (n.choose i : ℝ) * ‖iteratedFDerivWithin 𝕜 i f s x‖ *
‖iteratedFDerivWithin 𝕜 (n - i) g s x‖ := by
induction' n with n IH generalizing Eu Fu Gu
· simp only [Nat.zero_eq, norm_iteratedFDerivWithin_zero, zero_add, Finset.range_one,
Finset.sum_singleton, Nat.choose_self, Nat.cast_one, one_mul, Nat.sub_zero, ← mul_assoc]
apply B.le_opNorm₂
· have In : (n : ℕ∞) + 1 ≤ n.succ := by simp only [Nat.cast_succ, le_refl]
-- Porting note: the next line is a hack allowing Lean to find the operator norm instance.
let norm := @ContinuousLinearMap.hasOpNorm _ _ Eu ((Du →L[𝕜] Fu) →L[𝕜] Du →L[𝕜] Gu) _ _ _ _ _ _
(RingHom.id 𝕜)
have I1 :
‖iteratedFDerivWithin 𝕜 n (fun y : Du => B.precompR Du (f y) (fderivWithin 𝕜 g s y)) s x‖ ≤
‖B‖ * ∑ i ∈ Finset.range (n + 1), n.choose i * ‖iteratedFDerivWithin 𝕜 i f s x‖ *
‖iteratedFDerivWithin 𝕜 (n + 1 - i) g s x‖ := by
calc
‖iteratedFDerivWithin 𝕜 n (fun y : Du => B.precompR Du (f y) (fderivWithin 𝕜 g s y)) s x‖ ≤
‖B.precompR Du‖ * ∑ i ∈ Finset.range (n + 1),
n.choose i * ‖iteratedFDerivWithin 𝕜 i f s x‖ *
‖iteratedFDerivWithin 𝕜 (n - i) (fderivWithin 𝕜 g s) s x‖ :=
IH _ (hf.of_le (Nat.cast_le.2 (Nat.le_succ n))) (hg.fderivWithin hs In)
_ ≤ ‖B‖ * ∑ i ∈ Finset.range (n + 1), n.choose i * ‖iteratedFDerivWithin 𝕜 i f s x‖ *
‖iteratedFDerivWithin 𝕜 (n - i) (fderivWithin 𝕜 g s) s x‖ :=
mul_le_mul_of_nonneg_right (B.norm_precompR_le Du) (by positivity)
_ = _ := by
congr 1
apply Finset.sum_congr rfl fun i hi => ?_
rw [Nat.succ_sub (Nat.lt_succ_iff.1 (Finset.mem_range.1 hi)),
← norm_iteratedFDerivWithin_fderivWithin hs hx]
-- Porting note: the next line is a hack allowing Lean to find the operator norm instance.
let norm := @ContinuousLinearMap.hasOpNorm _ _ (Du →L[𝕜] Eu) (Fu →L[𝕜] Du →L[𝕜] Gu) _ _ _ _ _ _
(RingHom.id 𝕜)
have I2 :
‖iteratedFDerivWithin 𝕜 n (fun y : Du => B.precompL Du (fderivWithin 𝕜 f s y) (g y)) s x‖ ≤
‖B‖ * ∑ i ∈ Finset.range (n + 1), n.choose i * ‖iteratedFDerivWithin 𝕜 (i + 1) f s x‖ *
‖iteratedFDerivWithin 𝕜 (n - i) g s x‖ :=
calc
‖iteratedFDerivWithin 𝕜 n (fun y : Du => B.precompL Du (fderivWithin 𝕜 f s y) (g y)) s x‖ ≤
‖B.precompL Du‖ * ∑ i ∈ Finset.range (n + 1),
n.choose i * ‖iteratedFDerivWithin 𝕜 i (fderivWithin 𝕜 f s) s x‖ *
‖iteratedFDerivWithin 𝕜 (n - i) g s x‖ :=
IH _ (hf.fderivWithin hs In) (hg.of_le (Nat.cast_le.2 (Nat.le_succ n)))
_ ≤ ‖B‖ * ∑ i ∈ Finset.range (n + 1),
n.choose i * ‖iteratedFDerivWithin 𝕜 i (fderivWithin 𝕜 f s) s x‖ *
‖iteratedFDerivWithin 𝕜 (n - i) g s x‖ :=
mul_le_mul_of_nonneg_right (B.norm_precompL_le Du) (by positivity)
_ = _ := by
congr 1
apply Finset.sum_congr rfl fun i _ => ?_
rw [← norm_iteratedFDerivWithin_fderivWithin hs hx]
have J : iteratedFDerivWithin 𝕜 n
(fun y : Du => fderivWithin 𝕜 (fun y : Du => B (f y) (g y)) s y) s x =
iteratedFDerivWithin 𝕜 n (fun y => B.precompR Du (f y)
(fderivWithin 𝕜 g s y) + B.precompL Du (fderivWithin 𝕜 f s y) (g y)) s x := by
apply iteratedFDerivWithin_congr (fun y hy => ?_) hx
have L : (1 : ℕ∞) ≤ n.succ := by
simpa only [ENat.coe_one, Nat.one_le_cast] using Nat.succ_pos n
exact B.fderivWithin_of_bilinear (hf.differentiableOn L y hy) (hg.differentiableOn L y hy)
(hs y hy)
rw [← norm_iteratedFDerivWithin_fderivWithin hs hx, J]
have A : ContDiffOn 𝕜 n (fun y => B.precompR Du (f y) (fderivWithin 𝕜 g s y)) s :=
(B.precompR Du).isBoundedBilinearMap.contDiff.comp_contDiff_on₂
(hf.of_le (Nat.cast_le.2 (Nat.le_succ n))) (hg.fderivWithin hs In)
have A' : ContDiffOn 𝕜 n (fun y => B.precompL Du (fderivWithin 𝕜 f s y) (g y)) s :=
(B.precompL Du).isBoundedBilinearMap.contDiff.comp_contDiff_on₂ (hf.fderivWithin hs In)
(hg.of_le (Nat.cast_le.2 (Nat.le_succ n)))
rw [iteratedFDerivWithin_add_apply' A A' hs hx]
apply (norm_add_le _ _).trans ((add_le_add I1 I2).trans (le_of_eq ?_))
simp_rw [← mul_add, mul_assoc]
congr 1
exact (Finset.sum_choose_succ_mul
(fun i j => ‖iteratedFDerivWithin 𝕜 i f s x‖ * ‖iteratedFDerivWithin 𝕜 j g s x‖) n).symm
#align continuous_linear_map.norm_iterated_fderiv_within_le_of_bilinear_aux ContinuousLinearMap.norm_iteratedFDerivWithin_le_of_bilinear_aux
theorem ContinuousLinearMap.norm_iteratedFDerivWithin_le_of_bilinear (B : E →L[𝕜] F →L[𝕜] G)
{f : D → E} {g : D → F} {N : ℕ∞} {s : Set D} {x : D} (hf : ContDiffOn 𝕜 N f s)
(hg : ContDiffOn 𝕜 N g s) (hs : UniqueDiffOn 𝕜 s) (hx : x ∈ s) {n : ℕ} (hn : (n : ℕ∞) ≤ N) :
‖iteratedFDerivWithin 𝕜 n (fun y => B (f y) (g y)) s x‖ ≤
‖B‖ * ∑ i ∈ Finset.range (n + 1), (n.choose i : ℝ) * ‖iteratedFDerivWithin 𝕜 i f s x‖ *
‖iteratedFDerivWithin 𝕜 (n - i) g s x‖ := by
let Du : Type max uD uE uF uG := ULift.{max uE uF uG, uD} D
let Eu : Type max uD uE uF uG := ULift.{max uD uF uG, uE} E
let Fu : Type max uD uE uF uG := ULift.{max uD uE uG, uF} F
let Gu : Type max uD uE uF uG := ULift.{max uD uE uF, uG} G
have isoD : Du ≃ₗᵢ[𝕜] D := LinearIsometryEquiv.ulift 𝕜 D
have isoE : Eu ≃ₗᵢ[𝕜] E := LinearIsometryEquiv.ulift 𝕜 E
have isoF : Fu ≃ₗᵢ[𝕜] F := LinearIsometryEquiv.ulift 𝕜 F
have isoG : Gu ≃ₗᵢ[𝕜] G := LinearIsometryEquiv.ulift 𝕜 G
-- lift `f` and `g` to versions `fu` and `gu` on the lifted spaces.
set fu : Du → Eu := isoE.symm ∘ f ∘ isoD with hfu
set gu : Du → Fu := isoF.symm ∘ g ∘ isoD with hgu
-- lift the bilinear map `B` to a bilinear map `Bu` on the lifted spaces.
set Bu₀ : Eu →L[𝕜] Fu →L[𝕜] G := ((B.comp (isoE : Eu →L[𝕜] E)).flip.comp (isoF : Fu →L[𝕜] F)).flip
with hBu₀
let Bu : Eu →L[𝕜] Fu →L[𝕜] Gu :=
ContinuousLinearMap.compL 𝕜 Eu (Fu →L[𝕜] G) (Fu →L[𝕜] Gu)
(ContinuousLinearMap.compL 𝕜 Fu G Gu (isoG.symm : G →L[𝕜] Gu)) Bu₀
have hBu : Bu = ContinuousLinearMap.compL 𝕜 Eu (Fu →L[𝕜] G) (Fu →L[𝕜] Gu)
(ContinuousLinearMap.compL 𝕜 Fu G Gu (isoG.symm : G →L[𝕜] Gu)) Bu₀ := rfl
have Bu_eq : (fun y => Bu (fu y) (gu y)) = isoG.symm ∘ (fun y => B (f y) (g y)) ∘ isoD := by
ext1 y
simp [hBu, hBu₀, hfu, hgu]
-- All norms are preserved by the lifting process.
have Bu_le : ‖Bu‖ ≤ ‖B‖ := by
refine' ContinuousLinearMap.opNorm_le_bound _ (norm_nonneg B) fun y => _
refine' ContinuousLinearMap.opNorm_le_bound _ (by positivity) fun x => _
simp only [hBu, hBu₀, compL_apply, coe_comp', Function.comp_apply,
ContinuousLinearEquiv.coe_coe, LinearIsometryEquiv.coe_coe, flip_apply,
LinearIsometryEquiv.norm_map]
calc
‖B (isoE y) (isoF x)‖ ≤ ‖B (isoE y)‖ * ‖isoF x‖ := ContinuousLinearMap.le_opNorm _ _
_ ≤ ‖B‖ * ‖isoE y‖ * ‖isoF x‖ := by gcongr; apply ContinuousLinearMap.le_opNorm
_ = ‖B‖ * ‖y‖ * ‖x‖ := by simp only [LinearIsometryEquiv.norm_map]
let su := isoD ⁻¹' s
have hsu : UniqueDiffOn 𝕜 su := isoD.toContinuousLinearEquiv.uniqueDiffOn_preimage_iff.2 hs
let xu := isoD.symm x
have hxu : xu ∈ su := by
simpa only [xu, su, Set.mem_preimage, LinearIsometryEquiv.apply_symm_apply] using hx
have xu_x : isoD xu = x := by simp only [xu, LinearIsometryEquiv.apply_symm_apply]
have hfu : ContDiffOn 𝕜 n fu su :=
isoE.symm.contDiff.comp_contDiffOn
((hf.of_le hn).comp_continuousLinearMap (isoD : Du →L[𝕜] D))
have hgu : ContDiffOn 𝕜 n gu su :=
isoF.symm.contDiff.comp_contDiffOn
((hg.of_le hn).comp_continuousLinearMap (isoD : Du →L[𝕜] D))
have Nfu : ∀ i, ‖iteratedFDerivWithin 𝕜 i fu su xu‖ = ‖iteratedFDerivWithin 𝕜 i f s x‖ := by
intro i
rw [LinearIsometryEquiv.norm_iteratedFDerivWithin_comp_left _ _ hsu hxu]
rw [LinearIsometryEquiv.norm_iteratedFDerivWithin_comp_right _ _ hs, xu_x]
rwa [← xu_x] at hx
have Ngu : ∀ i, ‖iteratedFDerivWithin 𝕜 i gu su xu‖ = ‖iteratedFDerivWithin 𝕜 i g s x‖ := by
intro i
rw [LinearIsometryEquiv.norm_iteratedFDerivWithin_comp_left _ _ hsu hxu]
rw [LinearIsometryEquiv.norm_iteratedFDerivWithin_comp_right _ _ hs, xu_x]
rwa [← xu_x] at hx
have NBu :
‖iteratedFDerivWithin 𝕜 n (fun y => Bu (fu y) (gu y)) su xu‖ =
‖iteratedFDerivWithin 𝕜 n (fun y => B (f y) (g y)) s x‖ := by
rw [Bu_eq]
rw [LinearIsometryEquiv.norm_iteratedFDerivWithin_comp_left _ _ hsu hxu]
rw [LinearIsometryEquiv.norm_iteratedFDerivWithin_comp_right _ _ hs, xu_x]
rwa [← xu_x] at hx
-- state the bound for the lifted objects, and deduce the original bound from it.
have : ‖iteratedFDerivWithin 𝕜 n (fun y => Bu (fu y) (gu y)) su xu‖ ≤
‖Bu‖ * ∑ i ∈ Finset.range (n + 1), (n.choose i : ℝ) * ‖iteratedFDerivWithin 𝕜 i fu su xu‖ *
‖iteratedFDerivWithin 𝕜 (n - i) gu su xu‖ :=
Bu.norm_iteratedFDerivWithin_le_of_bilinear_aux hfu hgu hsu hxu
simp only [Nfu, Ngu, NBu] at this
exact this.trans (mul_le_mul_of_nonneg_right Bu_le (by positivity))
#align continuous_linear_map.norm_iterated_fderiv_within_le_of_bilinear ContinuousLinearMap.norm_iteratedFDerivWithin_le_of_bilinear
theorem ContinuousLinearMap.norm_iteratedFDeriv_le_of_bilinear (B : E →L[𝕜] F →L[𝕜] G) {f : D → E}
{g : D → F} {N : ℕ∞} (hf : ContDiff 𝕜 N f) (hg : ContDiff 𝕜 N g) (x : D) {n : ℕ}
(hn : (n : ℕ∞) ≤ N) :
‖iteratedFDeriv 𝕜 n (fun y => B (f y) (g y)) x‖ ≤ ‖B‖ * ∑ i ∈ Finset.range (n + 1),
(n.choose i : ℝ) * ‖iteratedFDeriv 𝕜 i f x‖ * ‖iteratedFDeriv 𝕜 (n - i) g x‖ := by
simp_rw [← iteratedFDerivWithin_univ]
exact B.norm_iteratedFDerivWithin_le_of_bilinear hf.contDiffOn hg.contDiffOn uniqueDiffOn_univ
(mem_univ x) hn
#align continuous_linear_map.norm_iterated_fderiv_le_of_bilinear ContinuousLinearMap.norm_iteratedFDeriv_le_of_bilinear
theorem ContinuousLinearMap.norm_iteratedFDerivWithin_le_of_bilinear_of_le_one
(B : E →L[𝕜] F →L[𝕜] G) {f : D → E} {g : D → F} {N : ℕ∞} {s : Set D} {x : D}
(hf : ContDiffOn 𝕜 N f s) (hg : ContDiffOn 𝕜 N g s) (hs : UniqueDiffOn 𝕜 s) (hx : x ∈ s) {n : ℕ}
(hn : (n : ℕ∞) ≤ N) (hB : ‖B‖ ≤ 1) : ‖iteratedFDerivWithin 𝕜 n (fun y => B (f y) (g y)) s x‖ ≤
∑ i ∈ Finset.range (n + 1), (n.choose i : ℝ) * ‖iteratedFDerivWithin 𝕜 i f s x‖ *
‖iteratedFDerivWithin 𝕜 (n - i) g s x‖ := by
apply (B.norm_iteratedFDerivWithin_le_of_bilinear hf hg hs hx hn).trans
exact mul_le_of_le_one_left (by positivity) hB
#align continuous_linear_map.norm_iterated_fderiv_within_le_of_bilinear_of_le_one ContinuousLinearMap.norm_iteratedFDerivWithin_le_of_bilinear_of_le_one
theorem ContinuousLinearMap.norm_iteratedFDeriv_le_of_bilinear_of_le_one (B : E →L[𝕜] F →L[𝕜] G)
{f : D → E} {g : D → F} {N : ℕ∞} (hf : ContDiff 𝕜 N f) (hg : ContDiff 𝕜 N g) (x : D) {n : ℕ}
(hn : (n : ℕ∞) ≤ N) (hB : ‖B‖ ≤ 1) : ‖iteratedFDeriv 𝕜 n (fun y => B (f y) (g y)) x‖ ≤
∑ i ∈ Finset.range (n + 1),
(n.choose i : ℝ) * ‖iteratedFDeriv 𝕜 i f x‖ * ‖iteratedFDeriv 𝕜 (n - i) g x‖ := by
simp_rw [← iteratedFDerivWithin_univ]
exact B.norm_iteratedFDerivWithin_le_of_bilinear_of_le_one hf.contDiffOn hg.contDiffOn
uniqueDiffOn_univ (mem_univ x) hn hB
#align continuous_linear_map.norm_iterated_fderiv_le_of_bilinear_of_le_one ContinuousLinearMap.norm_iteratedFDeriv_le_of_bilinear_of_le_one
section
variable {𝕜' : Type*} [NormedField 𝕜'] [NormedAlgebra 𝕜 𝕜'] [NormedSpace 𝕜' F]
[IsScalarTower 𝕜 𝕜' F]
theorem norm_iteratedFDerivWithin_smul_le {f : E → 𝕜'} {g : E → F} {N : ℕ∞}
(hf : ContDiffOn 𝕜 N f s) (hg : ContDiffOn 𝕜 N g s) (hs : UniqueDiffOn 𝕜 s) {x : E} (hx : x ∈ s)
{n : ℕ} (hn : (n : ℕ∞) ≤ N) : ‖iteratedFDerivWithin 𝕜 n (fun y => f y • g y) s x‖ ≤
∑ i ∈ Finset.range (n + 1), (n.choose i : ℝ) * ‖iteratedFDerivWithin 𝕜 i f s x‖ *
‖iteratedFDerivWithin 𝕜 (n - i) g s x‖ :=
(ContinuousLinearMap.lsmul 𝕜 𝕜' :
𝕜' →L[𝕜] F →L[𝕜] F).norm_iteratedFDerivWithin_le_of_bilinear_of_le_one
hf hg hs hx hn ContinuousLinearMap.opNorm_lsmul_le
#align norm_iterated_fderiv_within_smul_le norm_iteratedFDerivWithin_smul_le
theorem norm_iteratedFDeriv_smul_le {f : E → 𝕜'} {g : E → F} {N : ℕ∞} (hf : ContDiff 𝕜 N f)
(hg : ContDiff 𝕜 N g) (x : E) {n : ℕ} (hn : (n : ℕ∞) ≤ N) :
‖iteratedFDeriv 𝕜 n (fun y => f y • g y) x‖ ≤ ∑ i ∈ Finset.range (n + 1),
(n.choose i : ℝ) * ‖iteratedFDeriv 𝕜 i f x‖ * ‖iteratedFDeriv 𝕜 (n - i) g x‖ :=
(ContinuousLinearMap.lsmul 𝕜 𝕜' : 𝕜' →L[𝕜] F →L[𝕜] F).norm_iteratedFDeriv_le_of_bilinear_of_le_one
hf hg x hn ContinuousLinearMap.opNorm_lsmul_le
#align norm_iterated_fderiv_smul_le norm_iteratedFDeriv_smul_le
end
section
variable {ι : Type*} {A : Type*} [NormedRing A] [NormedAlgebra 𝕜 A] {A' : Type*} [NormedCommRing A']
[NormedAlgebra 𝕜 A']
theorem norm_iteratedFDerivWithin_mul_le {f : E → A} {g : E → A} {N : ℕ∞} (hf : ContDiffOn 𝕜 N f s)
(hg : ContDiffOn 𝕜 N g s) (hs : UniqueDiffOn 𝕜 s) {x : E} (hx : x ∈ s) {n : ℕ}
(hn : (n : ℕ∞) ≤ N) : ‖iteratedFDerivWithin 𝕜 n (fun y => f y * g y) s x‖ ≤
∑ i ∈ Finset.range (n + 1), (n.choose i : ℝ) * ‖iteratedFDerivWithin 𝕜 i f s x‖ *
‖iteratedFDerivWithin 𝕜 (n - i) g s x‖ :=
(ContinuousLinearMap.mul 𝕜 A :
A →L[𝕜] A →L[𝕜] A).norm_iteratedFDerivWithin_le_of_bilinear_of_le_one
hf hg hs hx hn (ContinuousLinearMap.opNorm_mul_le _ _)
#align norm_iterated_fderiv_within_mul_le norm_iteratedFDerivWithin_mul_le
theorem norm_iteratedFDeriv_mul_le {f : E → A} {g : E → A} {N : ℕ∞} (hf : ContDiff 𝕜 N f)
(hg : ContDiff 𝕜 N g) (x : E) {n : ℕ} (hn : (n : ℕ∞) ≤ N) :
‖iteratedFDeriv 𝕜 n (fun y => f y * g y) x‖ ≤ ∑ i ∈ Finset.range (n + 1),
(n.choose i : ℝ) * ‖iteratedFDeriv 𝕜 i f x‖ * ‖iteratedFDeriv 𝕜 (n - i) g x‖ := by
simp_rw [← iteratedFDerivWithin_univ]
exact norm_iteratedFDerivWithin_mul_le
hf.contDiffOn hg.contDiffOn uniqueDiffOn_univ (mem_univ x) hn
#align norm_iterated_fderiv_mul_le norm_iteratedFDeriv_mul_le
-- TODO: Add `norm_iteratedFDeriv[Within]_list_prod_le` for non-commutative `NormedRing A`.
theorem norm_iteratedFDerivWithin_prod_le [DecidableEq ι] [NormOneClass A'] {u : Finset ι}
{f : ι → E → A'} {N : ℕ∞} (hf : ∀ i ∈ u, ContDiffOn 𝕜 N (f i) s) (hs : UniqueDiffOn 𝕜 s) {x : E}
(hx : x ∈ s) {n : ℕ} (hn : (n : ℕ∞) ≤ N) :
‖iteratedFDerivWithin 𝕜 n (∏ j ∈ u, f j ·) s x‖ ≤
∑ p ∈ u.sym n, (p : Multiset ι).multinomial *
∏ j ∈ u, ‖iteratedFDerivWithin 𝕜 (Multiset.count j p) (f j) s x‖ := by
induction u using Finset.induction generalizing n with
| empty =>
cases n with
| zero => simp [Sym.eq_nil_of_card_zero]
| succ n => simp [iteratedFDerivWithin_succ_const _ _ hs hx]
| @insert i u hi IH =>
conv => lhs; simp only [Finset.prod_insert hi]
simp only [Finset.mem_insert, forall_eq_or_imp] at hf
refine le_trans (norm_iteratedFDerivWithin_mul_le hf.1 (contDiffOn_prod hf.2) hs hx hn) ?_
rw [← Finset.sum_coe_sort (Finset.sym _ _)]
rw [Finset.sum_equiv (Finset.symInsertEquiv hi) (t := Finset.univ)
(g := (fun v ↦ v.multinomial *
∏ j ∈ insert i u, ‖iteratedFDerivWithin 𝕜 (v.count j) (f j) s x‖) ∘
Sym.toMultiset ∘ Subtype.val ∘ (Finset.symInsertEquiv hi).symm)
(by simp) (by simp only [← comp_apply (g := Finset.symInsertEquiv hi), comp.assoc]; simp)]
rw [← Finset.univ_sigma_univ, Finset.sum_sigma, Finset.sum_range]
simp only [comp_apply, Finset.symInsertEquiv_symm_apply_coe]
refine Finset.sum_le_sum ?_
intro m _
specialize IH hf.2 (n := n - m) (le_trans (WithTop.coe_le_coe.mpr (n.sub_le m)) hn)
refine le_trans (mul_le_mul_of_nonneg_left IH (by simp [mul_nonneg])) ?_
rw [Finset.mul_sum, ← Finset.sum_coe_sort]
refine Finset.sum_le_sum ?_
simp only [Finset.mem_univ, forall_true_left, Subtype.forall, Finset.mem_sym_iff]
intro p hp
refine le_of_eq ?_
rw [Finset.prod_insert hi]
have hip : i ∉ p := mt (hp i) hi
rw [Sym.count_coe_fill_self_of_not_mem hip, Sym.multinomial_coe_fill_of_not_mem hip]
suffices ∏ j ∈ u, ‖iteratedFDerivWithin 𝕜 (Multiset.count j p) (f j) s x‖ =
∏ j ∈ u, ‖iteratedFDerivWithin 𝕜 (Multiset.count j (Sym.fill i m p)) (f j) s x‖ by
rw [this, Nat.cast_mul]
ring
refine Finset.prod_congr rfl ?_
intro j hj
have hji : j ≠ i := mt (· ▸ hj) hi
rw [Sym.count_coe_fill_of_ne hji]
theorem norm_iteratedFDeriv_prod_le [DecidableEq ι] [NormOneClass A'] {u : Finset ι}
{f : ι → E → A'} {N : ℕ∞} (hf : ∀ i ∈ u, ContDiff 𝕜 N (f i)) {x : E} {n : ℕ}
(hn : (n : ℕ∞) ≤ N) :
‖iteratedFDeriv 𝕜 n (∏ j ∈ u, f j ·) x‖ ≤
∑ p ∈ u.sym n, (p : Multiset ι).multinomial *
∏ j ∈ u, ‖iteratedFDeriv 𝕜 ((p : Multiset ι).count j) (f j) x‖ := by
simpa [iteratedFDerivWithin_univ] using
norm_iteratedFDerivWithin_prod_le (fun i hi ↦ (hf i hi).contDiffOn) uniqueDiffOn_univ
(mem_univ x) hn
end
theorem norm_iteratedFDerivWithin_comp_le_aux {Fu Gu : Type u} [NormedAddCommGroup Fu]
[NormedSpace 𝕜 Fu] [NormedAddCommGroup Gu] [NormedSpace 𝕜 Gu] {g : Fu → Gu} {f : E → Fu} {n : ℕ}
{s : Set E} {t : Set Fu} {x : E} (hg : ContDiffOn 𝕜 n g t) (hf : ContDiffOn 𝕜 n f s)
(ht : UniqueDiffOn 𝕜 t) (hs : UniqueDiffOn 𝕜 s) (hst : MapsTo f s t) (hx : x ∈ s) {C : ℝ}
{D : ℝ} (hC : ∀ i, i ≤ n → ‖iteratedFDerivWithin 𝕜 i g t (f x)‖ ≤ C)
(hD : ∀ i, 1 ≤ i → i ≤ n → ‖iteratedFDerivWithin 𝕜 i f s x‖ ≤ D ^ i) :
‖iteratedFDerivWithin 𝕜 n (g ∘ f) s x‖ ≤ n ! * C * D ^ n := by
induction' n using Nat.case_strong_induction_on with n IH generalizing Gu
· simpa [norm_iteratedFDerivWithin_zero, Nat.factorial_zero, algebraMap.coe_one, one_mul,
pow_zero, mul_one, comp_apply] using hC 0 le_rfl
have M : (n : ℕ∞) < n.succ := Nat.cast_lt.2 n.lt_succ_self
have Cnonneg : 0 ≤ C := (norm_nonneg _).trans (hC 0 bot_le)
have Dnonneg : 0 ≤ D := by
have : 1 ≤ n + 1 := by simp only [le_add_iff_nonneg_left, zero_le']
simpa only [pow_one] using (norm_nonneg _).trans (hD 1 le_rfl this)
-- use the inductive assumption to bound the derivatives of `g' ∘ f`.
have I : ∀ i ∈ Finset.range (n + 1),
‖iteratedFDerivWithin 𝕜 i (fderivWithin 𝕜 g t ∘ f) s x‖ ≤ i ! * C * D ^ i := by
intro i hi
simp only [Finset.mem_range_succ_iff] at hi
apply IH i hi
· apply hg.fderivWithin ht
simp only [Nat.cast_succ]
exact add_le_add_right (Nat.cast_le.2 hi) _
· apply hf.of_le (Nat.cast_le.2 (hi.trans n.le_succ))
· intro j hj
have : ‖iteratedFDerivWithin 𝕜 j (fderivWithin 𝕜 g t) t (f x)‖ =
‖iteratedFDerivWithin 𝕜 (j + 1) g t (f x)‖ := by
rw [iteratedFDerivWithin_succ_eq_comp_right ht (hst hx), comp_apply,
LinearIsometryEquiv.norm_map]
rw [this]
exact hC (j + 1) (add_le_add (hj.trans hi) le_rfl)
· intro j hj h'j
exact hD j hj (h'j.trans (hi.trans n.le_succ))
-- reformulate `hD` as a bound for the derivatives of `f'`.
have J : ∀ i, ‖iteratedFDerivWithin 𝕜 (n - i) (fderivWithin 𝕜 f s) s x‖ ≤ D ^ (n - i + 1) := by
intro i
have : ‖iteratedFDerivWithin 𝕜 (n - i) (fderivWithin 𝕜 f s) s x‖ =
‖iteratedFDerivWithin 𝕜 (n - i + 1) f s x‖ := by
rw [iteratedFDerivWithin_succ_eq_comp_right hs hx, comp_apply, LinearIsometryEquiv.norm_map]
rw [this]
apply hD
· simp only [le_add_iff_nonneg_left, zero_le']
· apply Nat.succ_le_succ tsub_le_self
-- Now put these together: first, notice that we have to bound `D^n (g' ∘ f ⬝ f')`.
calc
‖iteratedFDerivWithin 𝕜 (n + 1) (g ∘ f) s x‖ =
‖iteratedFDerivWithin 𝕜 n (fun y : E => fderivWithin 𝕜 (g ∘ f) s y) s x‖ := by
rw [iteratedFDerivWithin_succ_eq_comp_right hs hx, comp_apply,
LinearIsometryEquiv.norm_map]
_ = ‖iteratedFDerivWithin 𝕜 n (fun y : E => ContinuousLinearMap.compL 𝕜 E Fu Gu
(fderivWithin 𝕜 g t (f y)) (fderivWithin 𝕜 f s y)) s x‖ := by
have L : (1 : ℕ∞) ≤ n.succ := by simpa only [ENat.coe_one, Nat.one_le_cast] using n.succ_pos
congr 1
refine iteratedFDerivWithin_congr (fun y hy => ?_) hx _
apply fderivWithin.comp _ _ _ hst (hs y hy)
· exact hg.differentiableOn L _ (hst hy)
· exact hf.differentiableOn L _ hy
-- bound it using the fact that the composition of linear maps is a bilinear operation,
-- for which we have bounds for the`n`-th derivative.
_ ≤ ∑ i ∈ Finset.range (n + 1),
(n.choose i : ℝ) * ‖iteratedFDerivWithin 𝕜 i (fderivWithin 𝕜 g t ∘ f) s x‖ *
‖iteratedFDerivWithin 𝕜 (n - i) (fderivWithin 𝕜 f s) s x‖ := by
have A : ContDiffOn 𝕜 n (fderivWithin 𝕜 g t ∘ f) s := by
apply ContDiffOn.comp _ (hf.of_le M.le) hst
apply hg.fderivWithin ht
simp only [Nat.cast_succ, le_refl]
have B : ContDiffOn 𝕜 n (fderivWithin 𝕜 f s) s := by
apply hf.fderivWithin hs
simp only [Nat.cast_succ, le_refl]
exact (ContinuousLinearMap.compL 𝕜 E Fu Gu).norm_iteratedFDerivWithin_le_of_bilinear_of_le_one
A B hs hx le_rfl (ContinuousLinearMap.norm_compL_le 𝕜 E Fu Gu)
-- bound each of the terms using the estimates on previous derivatives (that use the inductive
-- assumption for `g' ∘ f`).
_ ≤ ∑ i ∈ Finset.range (n + 1), (n.choose i : ℝ) * (i ! * C * D ^ i) * D ^ (n - i + 1) := by
gcongr with i hi
· simp only [mul_assoc (n.choose i : ℝ)]
exact I i hi
· exact J i
-- We are left with trivial algebraic manipulations to see that this is smaller than
-- the claimed bound.
_ = ∑ i ∈ Finset.range (n + 1),
-- Porting note: had to insert a few more explicit type ascriptions in this and similar
-- expressions.
(n ! : ℝ) * ((i ! : ℝ)⁻¹ * i !) * C * (D ^ i * D ^ (n - i + 1)) * ((n - i)! : ℝ)⁻¹ := by
congr! 1 with i hi
simp only [Nat.cast_choose ℝ (Finset.mem_range_succ_iff.1 hi), div_eq_inv_mul, mul_inv]
ring
_ = ∑ i ∈ Finset.range (n + 1), (n ! : ℝ) * 1 * C * D ^ (n + 1) * ((n - i)! : ℝ)⁻¹ := by
congr! with i hi
· apply inv_mul_cancel
simpa only [Ne, Nat.cast_eq_zero] using i.factorial_ne_zero
· rw [← pow_add]
congr 1
rw [Nat.add_succ, Nat.succ_inj']
exact Nat.add_sub_of_le (Finset.mem_range_succ_iff.1 hi)
_ ≤ ∑ i ∈ Finset.range (n + 1), (n ! : ℝ) * 1 * C * D ^ (n + 1) * 1 := by
gcongr with i
apply inv_le_one
simpa only [Nat.one_le_cast] using (n - i).factorial_pos
_ = (n + 1)! * C * D ^ (n + 1) := by
simp only [mul_assoc, mul_one, Finset.sum_const, Finset.card_range, nsmul_eq_mul,
Nat.factorial_succ, Nat.cast_mul]
#align norm_iterated_fderiv_within_comp_le_aux norm_iteratedFDerivWithin_comp_le_aux
theorem norm_iteratedFDerivWithin_comp_le {g : F → G} {f : E → F} {n : ℕ} {s : Set E} {t : Set F}
{x : E} {N : ℕ∞} (hg : ContDiffOn 𝕜 N g t) (hf : ContDiffOn 𝕜 N f s) (hn : (n : ℕ∞) ≤ N)
(ht : UniqueDiffOn 𝕜 t) (hs : UniqueDiffOn 𝕜 s) (hst : MapsTo f s t) (hx : x ∈ s) {C : ℝ}
{D : ℝ} (hC : ∀ i, i ≤ n → ‖iteratedFDerivWithin 𝕜 i g t (f x)‖ ≤ C)
(hD : ∀ i, 1 ≤ i → i ≤ n → ‖iteratedFDerivWithin 𝕜 i f s x‖ ≤ D ^ i) :
‖iteratedFDerivWithin 𝕜 n (g ∘ f) s x‖ ≤ n ! * C * D ^ n := by
let Fu : Type max uF uG := ULift.{uG, uF} F
let Gu : Type max uF uG := ULift.{uF, uG} G
have isoF : Fu ≃ₗᵢ[𝕜] F := LinearIsometryEquiv.ulift 𝕜 F
have isoG : Gu ≃ₗᵢ[𝕜] G := LinearIsometryEquiv.ulift 𝕜 G
-- lift `f` and `g` to versions `fu` and `gu` on the lifted spaces.
let fu : E → Fu := isoF.symm ∘ f
let gu : Fu → Gu := isoG.symm ∘ g ∘ isoF
let tu := isoF ⁻¹' t
have htu : UniqueDiffOn 𝕜 tu := isoF.toContinuousLinearEquiv.uniqueDiffOn_preimage_iff.2 ht
have hstu : MapsTo fu s tu := fun y hy ↦ by
simpa only [fu, tu, mem_preimage, comp_apply, LinearIsometryEquiv.apply_symm_apply] using hst hy
have Ffu : isoF (fu x) = f x := by
simp only [fu, comp_apply, LinearIsometryEquiv.apply_symm_apply]
-- All norms are preserved by the lifting process.
have hfu : ContDiffOn 𝕜 n fu s := isoF.symm.contDiff.comp_contDiffOn (hf.of_le hn)
have hgu : ContDiffOn 𝕜 n gu tu :=
isoG.symm.contDiff.comp_contDiffOn
((hg.of_le hn).comp_continuousLinearMap (isoF : Fu →L[𝕜] F))
have Nfu : ∀ i, ‖iteratedFDerivWithin 𝕜 i fu s x‖ = ‖iteratedFDerivWithin 𝕜 i f s x‖ := fun i ↦ by
rw [LinearIsometryEquiv.norm_iteratedFDerivWithin_comp_left _ _ hs hx]
simp_rw [← Nfu] at hD
have Ngu : ∀ i,
‖iteratedFDerivWithin 𝕜 i gu tu (fu x)‖ = ‖iteratedFDerivWithin 𝕜 i g t (f x)‖ := fun i ↦ by
rw [LinearIsometryEquiv.norm_iteratedFDerivWithin_comp_left _ _ htu (hstu hx)]
rw [LinearIsometryEquiv.norm_iteratedFDerivWithin_comp_right _ _ ht, Ffu]
rw [Ffu]
exact hst hx
simp_rw [← Ngu] at hC
have Nfgu :
‖iteratedFDerivWithin 𝕜 n (g ∘ f) s x‖ = ‖iteratedFDerivWithin 𝕜 n (gu ∘ fu) s x‖ := by
have : gu ∘ fu = isoG.symm ∘ g ∘ f := by
ext x
simp only [fu, gu, comp_apply, LinearIsometryEquiv.map_eq_iff,
LinearIsometryEquiv.apply_symm_apply]
rw [this, LinearIsometryEquiv.norm_iteratedFDerivWithin_comp_left _ _ hs hx]
-- deduce the required bound from the one for `gu ∘ fu`.
rw [Nfgu]
exact norm_iteratedFDerivWithin_comp_le_aux hgu hfu htu hs hstu hx hC hD
#align norm_iterated_fderiv_within_comp_le norm_iteratedFDerivWithin_comp_le
theorem norm_iteratedFDeriv_comp_le {g : F → G} {f : E → F} {n : ℕ} {N : ℕ∞} (hg : ContDiff 𝕜 N g)
(hf : ContDiff 𝕜 N f) (hn : (n : ℕ∞) ≤ N) (x : E) {C : ℝ} {D : ℝ}
(hC : ∀ i, i ≤ n → ‖iteratedFDeriv 𝕜 i g (f x)‖ ≤ C)
(hD : ∀ i, 1 ≤ i → i ≤ n → ‖iteratedFDeriv 𝕜 i f x‖ ≤ D ^ i) :
‖iteratedFDeriv 𝕜 n (g ∘ f) x‖ ≤ n ! * C * D ^ n := by
simp_rw [← iteratedFDerivWithin_univ] at hC hD ⊢
exact norm_iteratedFDerivWithin_comp_le hg.contDiffOn hf.contDiffOn hn uniqueDiffOn_univ
uniqueDiffOn_univ (mapsTo_univ _ _) (mem_univ x) hC hD
#align norm_iterated_fderiv_comp_le norm_iteratedFDeriv_comp_le
section Apply
theorem norm_iteratedFDerivWithin_clm_apply {f : E → F →L[𝕜] G} {g : E → F} {s : Set E} {x : E}
{N : ℕ∞} {n : ℕ} (hf : ContDiffOn 𝕜 N f s) (hg : ContDiffOn 𝕜 N g s) (hs : UniqueDiffOn 𝕜 s)
(hx : x ∈ s) (hn : ↑n ≤ N) : ‖iteratedFDerivWithin 𝕜 n (fun y => (f y) (g y)) s x‖ ≤
∑ i ∈ Finset.range (n + 1), ↑(n.choose i) * ‖iteratedFDerivWithin 𝕜 i f s x‖ *
‖iteratedFDerivWithin 𝕜 (n - i) g s x‖ := by
let B : (F →L[𝕜] G) →L[𝕜] F →L[𝕜] G := ContinuousLinearMap.flip (ContinuousLinearMap.apply 𝕜 G)
have hB : ‖B‖ ≤ 1 := by
simp only [B, ContinuousLinearMap.opNorm_flip, ContinuousLinearMap.apply]
refine ContinuousLinearMap.opNorm_le_bound _ zero_le_one fun f => ?_
simp only [ContinuousLinearMap.coe_id', id, one_mul]
rfl
exact B.norm_iteratedFDerivWithin_le_of_bilinear_of_le_one hf hg hs hx hn hB
#align norm_iterated_fderiv_within_clm_apply norm_iteratedFDerivWithin_clm_apply
theorem norm_iteratedFDeriv_clm_apply {f : E → F →L[𝕜] G} {g : E → F} {N : ℕ∞} {n : ℕ}
(hf : ContDiff 𝕜 N f) (hg : ContDiff 𝕜 N g) (x : E) (hn : ↑n ≤ N) :
‖iteratedFDeriv 𝕜 n (fun y : E => (f y) (g y)) x‖ ≤ ∑ i ∈ Finset.range (n + 1),
↑(n.choose i) * ‖iteratedFDeriv 𝕜 i f x‖ * ‖iteratedFDeriv 𝕜 (n - i) g x‖ := by
simp only [← iteratedFDerivWithin_univ]
exact norm_iteratedFDerivWithin_clm_apply hf.contDiffOn hg.contDiffOn uniqueDiffOn_univ
(Set.mem_univ x) hn
#align norm_iterated_fderiv_clm_apply norm_iteratedFDeriv_clm_apply
theorem norm_iteratedFDerivWithin_clm_apply_const {f : E → F →L[𝕜] G} {c : F} {s : Set E} {x : E}
{N : ℕ∞} {n : ℕ} (hf : ContDiffOn 𝕜 N f s) (hs : UniqueDiffOn 𝕜 s) (hx : x ∈ s) (hn : ↑n ≤ N) :
‖iteratedFDerivWithin 𝕜 n (fun y : E => (f y) c) s x‖ ≤
‖c‖ * ‖iteratedFDerivWithin 𝕜 n f s x‖ := by
let g : (F →L[𝕜] G) →L[𝕜] G := ContinuousLinearMap.apply 𝕜 G c
have h := g.norm_compContinuousMultilinearMap_le (iteratedFDerivWithin 𝕜 n f s x)
rw [← g.iteratedFDerivWithin_comp_left hf hs hx hn] at h
refine h.trans (mul_le_mul_of_nonneg_right ?_ (norm_nonneg _))
refine g.opNorm_le_bound (norm_nonneg _) fun f => ?_
rw [ContinuousLinearMap.apply_apply, mul_comm]
exact f.le_opNorm c
#align norm_iterated_fderiv_within_clm_apply_const norm_iteratedFDerivWithin_clm_apply_const
| Mathlib/Analysis/Calculus/ContDiff/Bounds.lean | 574 | 579 | theorem norm_iteratedFDeriv_clm_apply_const {f : E → F →L[𝕜] G} {c : F} {x : E} {N : ℕ∞} {n : ℕ}
(hf : ContDiff 𝕜 N f) (hn : ↑n ≤ N) :
‖iteratedFDeriv 𝕜 n (fun y : E => (f y) c) x‖ ≤ ‖c‖ * ‖iteratedFDeriv 𝕜 n f x‖ := by |
simp only [← iteratedFDerivWithin_univ]
exact norm_iteratedFDerivWithin_clm_apply_const hf.contDiffOn uniqueDiffOn_univ
(Set.mem_univ x) hn
|
import Mathlib.Control.Monad.Basic
import Mathlib.Data.Fintype.Basic
import Mathlib.Data.List.ProdSigma
#align_import data.fin_enum from "leanprover-community/mathlib"@"9003f28797c0664a49e4179487267c494477d853"
universe u v
open Finset
class FinEnum (α : Sort*) where
card : ℕ
equiv : α ≃ Fin card
[decEq : DecidableEq α]
#align fin_enum FinEnum
attribute [instance 100] FinEnum.decEq
namespace FinEnum
variable {α : Type u} {β : α → Type v}
def ofEquiv (α) {β} [FinEnum α] (h : β ≃ α) : FinEnum β where
card := card α
equiv := h.trans (equiv)
decEq := (h.trans (equiv)).decidableEq
#align fin_enum.of_equiv FinEnum.ofEquiv
def ofNodupList [DecidableEq α] (xs : List α) (h : ∀ x : α, x ∈ xs) (h' : List.Nodup xs) :
FinEnum α where
card := xs.length
equiv :=
⟨fun x => ⟨xs.indexOf x, by rw [List.indexOf_lt_length]; apply h⟩, xs.get, fun x => by simp,
fun i => by ext; simp [List.get_indexOf h']⟩
#align fin_enum.of_nodup_list FinEnum.ofNodupList
def ofList [DecidableEq α] (xs : List α) (h : ∀ x : α, x ∈ xs) : FinEnum α :=
ofNodupList xs.dedup (by simp [*]) (List.nodup_dedup _)
#align fin_enum.of_list FinEnum.ofList
def toList (α) [FinEnum α] : List α :=
(List.finRange (card α)).map (equiv).symm
#align fin_enum.to_list FinEnum.toList
open Function
@[simp]
theorem mem_toList [FinEnum α] (x : α) : x ∈ toList α := by
simp [toList]; exists equiv x; simp
#align fin_enum.mem_to_list FinEnum.mem_toList
@[simp]
theorem nodup_toList [FinEnum α] : List.Nodup (toList α) := by
simp [toList]; apply List.Nodup.map <;> [apply Equiv.injective; apply List.nodup_finRange]
#align fin_enum.nodup_to_list FinEnum.nodup_toList
def ofSurjective {β} (f : β → α) [DecidableEq α] [FinEnum β] (h : Surjective f) : FinEnum α :=
ofList ((toList β).map f) (by intro; simp; exact h _)
#align fin_enum.of_surjective FinEnum.ofSurjective
noncomputable def ofInjective {α β} (f : α → β) [DecidableEq α] [FinEnum β] (h : Injective f) :
FinEnum α :=
ofList ((toList β).filterMap (partialInv f))
(by
intro x
simp only [mem_toList, true_and_iff, List.mem_filterMap]
use f x
simp only [h, Function.partialInv_left])
#align fin_enum.of_injective FinEnum.ofInjective
instance pempty : FinEnum PEmpty :=
ofList [] fun x => PEmpty.elim x
#align fin_enum.pempty FinEnum.pempty
instance empty : FinEnum Empty :=
ofList [] fun x => Empty.elim x
#align fin_enum.empty FinEnum.empty
instance punit : FinEnum PUnit :=
ofList [PUnit.unit] fun x => by cases x; simp
#align fin_enum.punit FinEnum.punit
instance prod {β} [FinEnum α] [FinEnum β] : FinEnum (α × β) :=
ofList (toList α ×ˢ toList β) fun x => by cases x; simp
#align fin_enum.prod FinEnum.prod
instance sum {β} [FinEnum α] [FinEnum β] : FinEnum (Sum α β) :=
ofList ((toList α).map Sum.inl ++ (toList β).map Sum.inr) fun x => by cases x <;> simp
#align fin_enum.sum FinEnum.sum
instance fin {n} : FinEnum (Fin n) :=
ofList (List.finRange _) (by simp)
#align fin_enum.fin FinEnum.fin
instance Quotient.enum [FinEnum α] (s : Setoid α) [DecidableRel ((· ≈ ·) : α → α → Prop)] :
FinEnum (Quotient s) :=
FinEnum.ofSurjective Quotient.mk'' fun x => Quotient.inductionOn x fun x => ⟨x, rfl⟩
#align fin_enum.quotient.enum FinEnum.Quotient.enum
def Finset.enum [DecidableEq α] : List α → List (Finset α)
| [] => [∅]
| x :: xs => do
let r ← Finset.enum xs
[r, {x} ∪ r]
#align fin_enum.finset.enum FinEnum.Finset.enum
@[simp]
| Mathlib/Data/FinEnum.lean | 132 | 163 | theorem Finset.mem_enum [DecidableEq α] (s : Finset α) (xs : List α) :
s ∈ Finset.enum xs ↔ ∀ x ∈ s, x ∈ xs := by |
induction' xs with xs_hd generalizing s <;> simp [*, Finset.enum]
· simp [Finset.eq_empty_iff_forall_not_mem]
· constructor
· rintro ⟨a, h, h'⟩ x hx
cases' h' with _ h' a b
· right
apply h
subst a
exact hx
· simp only [h', mem_union, mem_singleton] at hx ⊢
cases' hx with hx hx'
· exact Or.inl hx
· exact Or.inr (h _ hx')
· intro h
exists s \ ({xs_hd} : Finset α)
simp only [and_imp, mem_sdiff, mem_singleton]
simp only [or_iff_not_imp_left] at h
exists h
by_cases h : xs_hd ∈ s
· have : {xs_hd} ⊆ s := by
simp only [HasSubset.Subset, *, forall_eq, mem_singleton]
simp only [union_sdiff_of_subset this, or_true_iff, Finset.union_sdiff_of_subset,
eq_self_iff_true]
· left
symm
simp only [sdiff_eq_self]
intro a
simp only [and_imp, mem_inter, mem_singleton]
rintro h₀ rfl
exact (h h₀).elim
|
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)
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
#align finrank_vector_span_image_finset_le finrank_vectorSpan_image_finset_le
theorem finrank_vectorSpan_range_le [Fintype ι] (p : ι → P) {n : ℕ} (hc : Fintype.card ι = n + 1) :
finrank k (vectorSpan k (Set.range p)) ≤ n := by
classical
rw [← Set.image_univ, ← Finset.coe_univ, ← Finset.coe_image]
rw [← Finset.card_univ] at hc
exact finrank_vectorSpan_image_finset_le _ _ _ hc
#align finrank_vector_span_range_le finrank_vectorSpan_range_le
lemma finrank_vectorSpan_range_add_one_le [Fintype ι] [Nonempty ι] (p : ι → P) :
finrank k (vectorSpan k (Set.range p)) + 1 ≤ Fintype.card ι :=
(le_tsub_iff_right $ Nat.succ_le_iff.2 Fintype.card_pos).1 $ finrank_vectorSpan_range_le _ _
(tsub_add_cancel_of_le $ Nat.succ_le_iff.2 Fintype.card_pos).symm
theorem affineIndependent_iff_finrank_vectorSpan_eq [Fintype ι] (p : ι → P) {n : ℕ}
(hc : Fintype.card ι = n + 1) :
AffineIndependent k p ↔ finrank k (vectorSpan k (Set.range p)) = n := by
classical
have hn : Nonempty ι := by simp [← Fintype.card_pos_iff, hc]
cases' hn with i₁
rw [affineIndependent_iff_linearIndependent_vsub _ _ i₁,
linearIndependent_iff_card_eq_finrank_span, eq_comm,
vectorSpan_range_eq_span_range_vsub_right_ne k p i₁, Set.finrank]
rw [← Finset.card_univ] at hc
rw [Fintype.subtype_card]
simp [Finset.filter_ne', Finset.card_erase_of_mem, hc]
#align affine_independent_iff_finrank_vector_span_eq affineIndependent_iff_finrank_vectorSpan_eq
theorem affineIndependent_iff_le_finrank_vectorSpan [Fintype ι] (p : ι → P) {n : ℕ}
(hc : Fintype.card ι = n + 1) :
AffineIndependent k p ↔ n ≤ finrank k (vectorSpan k (Set.range p)) := by
rw [affineIndependent_iff_finrank_vectorSpan_eq k p hc]
constructor
· rintro rfl
rfl
· exact fun hle => le_antisymm (finrank_vectorSpan_range_le k p hc) hle
#align affine_independent_iff_le_finrank_vector_span affineIndependent_iff_le_finrank_vectorSpan
theorem affineIndependent_iff_not_finrank_vectorSpan_le [Fintype ι] (p : ι → P) {n : ℕ}
(hc : Fintype.card ι = n + 2) :
AffineIndependent k p ↔ ¬finrank k (vectorSpan k (Set.range p)) ≤ n := by
rw [affineIndependent_iff_le_finrank_vectorSpan k p hc, ← Nat.lt_iff_add_one_le, lt_iff_not_ge]
#align affine_independent_iff_not_finrank_vector_span_le affineIndependent_iff_not_finrank_vectorSpan_le
theorem finrank_vectorSpan_le_iff_not_affineIndependent [Fintype ι] (p : ι → P) {n : ℕ}
(hc : Fintype.card ι = n + 2) :
finrank k (vectorSpan k (Set.range p)) ≤ n ↔ ¬AffineIndependent k p :=
(not_iff_comm.1 (affineIndependent_iff_not_finrank_vectorSpan_le k p hc).symm).symm
#align finrank_vector_span_le_iff_not_affine_independent finrank_vectorSpan_le_iff_not_affineIndependent
variable {k}
lemma AffineIndependent.card_le_finrank_succ [Fintype ι] {p : ι → P} (hp : AffineIndependent k p) :
Fintype.card ι ≤ FiniteDimensional.finrank k (vectorSpan k (Set.range p)) + 1 := by
cases isEmpty_or_nonempty ι
· simp [Fintype.card_eq_zero]
rw [← tsub_le_iff_right]
exact (affineIndependent_iff_le_finrank_vectorSpan _ _
(tsub_add_cancel_of_le <| Nat.one_le_iff_ne_zero.2 Fintype.card_ne_zero).symm).1 hp
open Finset in
lemma AffineIndependent.card_le_card_of_subset_affineSpan {s t : Finset V}
(hs : AffineIndependent k ((↑) : s → V)) (hst : (s : Set V) ⊆ affineSpan k (t : Set V)) :
s.card ≤ t.card := by
obtain rfl | hs' := s.eq_empty_or_nonempty
· simp
obtain rfl | ht' := t.eq_empty_or_nonempty
· simpa [Set.subset_empty_iff] using hst
have := hs'.to_subtype
have := ht'.to_set.to_subtype
have direction_le := AffineSubspace.direction_le (affineSpan_mono k hst)
rw [AffineSubspace.affineSpan_coe, direction_affineSpan, direction_affineSpan,
← @Subtype.range_coe _ (s : Set V), ← @Subtype.range_coe _ (t : Set V)] at direction_le
have finrank_le := add_le_add_right (Submodule.finrank_le_finrank_of_le direction_le) 1
-- We use `erw` to elide the difference between `↥s` and `↥(s : Set V)}`
erw [hs.finrank_vectorSpan_add_one] at finrank_le
simpa using finrank_le.trans <| finrank_vectorSpan_range_add_one_le _ _
open Finset in
lemma AffineIndependent.card_lt_card_of_affineSpan_lt_affineSpan {s t : Finset V}
(hs : AffineIndependent k ((↑) : s → V))
(hst : affineSpan k (s : Set V) < affineSpan k (t : Set V)) : s.card < t.card := by
obtain rfl | hs' := s.eq_empty_or_nonempty
· simpa [card_pos] using hst
obtain rfl | ht' := t.eq_empty_or_nonempty
· simp [Set.subset_empty_iff] at hst
have := hs'.to_subtype
have := ht'.to_set.to_subtype
have dir_lt := AffineSubspace.direction_lt_of_nonempty (k := k) hst $ hs'.to_set.affineSpan k
rw [direction_affineSpan, direction_affineSpan,
← @Subtype.range_coe _ (s : Set V), ← @Subtype.range_coe _ (t : Set V)] at dir_lt
have finrank_lt := add_lt_add_right (Submodule.finrank_lt_finrank_of_lt dir_lt) 1
-- We use `erw` to elide the difference between `↥s` and `↥(s : Set V)}`
erw [hs.finrank_vectorSpan_add_one] at finrank_lt
simpa using finrank_lt.trans_le <| finrank_vectorSpan_range_add_one_le _ _
theorem AffineIndependent.vectorSpan_image_finset_eq_of_le_of_card_eq_finrank_add_one
[DecidableEq P] {p : ι → P}
(hi : AffineIndependent k p) {s : Finset ι} {sm : Submodule k V} [FiniteDimensional k sm]
(hle : vectorSpan k (s.image p : Set P) ≤ sm) (hc : Finset.card s = finrank k sm + 1) :
vectorSpan k (s.image p : Set P) = sm :=
eq_of_le_of_finrank_eq hle <| hi.finrank_vectorSpan_image_finset hc
#align affine_independent.vector_span_image_finset_eq_of_le_of_card_eq_finrank_add_one AffineIndependent.vectorSpan_image_finset_eq_of_le_of_card_eq_finrank_add_one
theorem AffineIndependent.vectorSpan_eq_of_le_of_card_eq_finrank_add_one [Fintype ι] {p : ι → P}
(hi : AffineIndependent k p) {sm : Submodule k V} [FiniteDimensional k sm]
(hle : vectorSpan k (Set.range p) ≤ sm) (hc : Fintype.card ι = finrank k sm + 1) :
vectorSpan k (Set.range p) = sm :=
eq_of_le_of_finrank_eq hle <| hi.finrank_vectorSpan hc
#align affine_independent.vector_span_eq_of_le_of_card_eq_finrank_add_one AffineIndependent.vectorSpan_eq_of_le_of_card_eq_finrank_add_one
theorem AffineIndependent.affineSpan_image_finset_eq_of_le_of_card_eq_finrank_add_one
[DecidableEq P] {p : ι → P}
(hi : AffineIndependent k p) {s : Finset ι} {sp : AffineSubspace k P}
[FiniteDimensional k sp.direction] (hle : affineSpan k (s.image p : Set P) ≤ sp)
(hc : Finset.card s = finrank k sp.direction + 1) : affineSpan k (s.image p : Set P) = sp := by
have hn : s.Nonempty := by
rw [← Finset.card_pos, hc]
apply Nat.succ_pos
refine eq_of_direction_eq_of_nonempty_of_le ?_ ((hn.image p).to_set.affineSpan k) hle
have hd := direction_le hle
rw [direction_affineSpan] at hd ⊢
exact hi.vectorSpan_image_finset_eq_of_le_of_card_eq_finrank_add_one hd hc
#align affine_independent.affine_span_image_finset_eq_of_le_of_card_eq_finrank_add_one AffineIndependent.affineSpan_image_finset_eq_of_le_of_card_eq_finrank_add_one
theorem AffineIndependent.affineSpan_eq_of_le_of_card_eq_finrank_add_one [Fintype ι] {p : ι → P}
(hi : AffineIndependent k p) {sp : AffineSubspace k P} [FiniteDimensional k sp.direction]
(hle : affineSpan k (Set.range p) ≤ sp) (hc : Fintype.card ι = finrank k sp.direction + 1) :
affineSpan k (Set.range p) = sp := by
classical
rw [← Finset.card_univ] at hc
rw [← Set.image_univ, ← Finset.coe_univ, ← Finset.coe_image] at hle ⊢
exact hi.affineSpan_image_finset_eq_of_le_of_card_eq_finrank_add_one hle hc
#align affine_independent.affine_span_eq_of_le_of_card_eq_finrank_add_one AffineIndependent.affineSpan_eq_of_le_of_card_eq_finrank_add_one
theorem AffineIndependent.affineSpan_eq_top_iff_card_eq_finrank_add_one [FiniteDimensional k V]
[Fintype ι] {p : ι → P} (hi : AffineIndependent k p) :
affineSpan k (Set.range p) = ⊤ ↔ Fintype.card ι = finrank k V + 1 := by
constructor
· intro h_tot
let n := Fintype.card ι - 1
have hn : Fintype.card ι = n + 1 :=
(Nat.succ_pred_eq_of_pos (card_pos_of_affineSpan_eq_top k V P h_tot)).symm
rw [hn, ← finrank_top, ← (vectorSpan_eq_top_of_affineSpan_eq_top k V P) h_tot,
← hi.finrank_vectorSpan hn]
· intro hc
rw [← finrank_top, ← direction_top k V P] at hc
exact hi.affineSpan_eq_of_le_of_card_eq_finrank_add_one le_top hc
#align affine_independent.affine_span_eq_top_iff_card_eq_finrank_add_one AffineIndependent.affineSpan_eq_top_iff_card_eq_finrank_add_one
theorem Affine.Simplex.span_eq_top [FiniteDimensional k V] {n : ℕ} (T : Affine.Simplex k V n)
(hrank : finrank k V = n) : affineSpan k (Set.range T.points) = ⊤ := by
rw [AffineIndependent.affineSpan_eq_top_iff_card_eq_finrank_add_one T.independent,
Fintype.card_fin, hrank]
#align affine.simplex.span_eq_top Affine.Simplex.span_eq_top
instance finiteDimensional_vectorSpan_insert (s : AffineSubspace k P)
[FiniteDimensional k s.direction] (p : P) :
FiniteDimensional k (vectorSpan k (insert p (s : Set P))) := by
rw [← direction_affineSpan, ← affineSpan_insert_affineSpan]
rcases (s : Set P).eq_empty_or_nonempty with (hs | ⟨p₀, hp₀⟩)
· rw [coe_eq_bot_iff] at hs
rw [hs, bot_coe, span_empty, bot_coe, direction_affineSpan]
convert finiteDimensional_bot k V <;> simp
· rw [affineSpan_coe, direction_affineSpan_insert hp₀]
infer_instance
#align finite_dimensional_vector_span_insert finiteDimensional_vectorSpan_insert
instance finiteDimensional_direction_affineSpan_insert (s : AffineSubspace k P)
[FiniteDimensional k s.direction] (p : P) :
FiniteDimensional k (affineSpan k (insert p (s : Set P))).direction :=
(direction_affineSpan k (insert p (s : Set P))).symm ▸ finiteDimensional_vectorSpan_insert s p
#align finite_dimensional_direction_affine_span_insert finiteDimensional_direction_affineSpan_insert
variable (k)
instance finiteDimensional_vectorSpan_insert_set (s : Set P) [FiniteDimensional k (vectorSpan k s)]
(p : P) : FiniteDimensional k (vectorSpan k (insert p s)) := by
haveI : FiniteDimensional k (affineSpan k s).direction :=
(direction_affineSpan k s).symm ▸ inferInstance
rw [← direction_affineSpan, ← affineSpan_insert_affineSpan, direction_affineSpan]
exact finiteDimensional_vectorSpan_insert (affineSpan k s) p
#align finite_dimensional_vector_span_insert_set finiteDimensional_vectorSpan_insert_set
def Collinear (s : Set P) : Prop :=
Module.rank k (vectorSpan k s) ≤ 1
#align collinear Collinear
theorem collinear_iff_rank_le_one (s : Set P) :
Collinear k s ↔ Module.rank k (vectorSpan k s) ≤ 1 := Iff.rfl
#align collinear_iff_rank_le_one collinear_iff_rank_le_one
variable {k}
theorem collinear_iff_finrank_le_one {s : Set P} [FiniteDimensional k (vectorSpan k s)] :
Collinear k s ↔ finrank k (vectorSpan k s) ≤ 1 := by
have h := collinear_iff_rank_le_one k s
rw [← finrank_eq_rank] at h
exact mod_cast h
#align collinear_iff_finrank_le_one collinear_iff_finrank_le_one
alias ⟨Collinear.finrank_le_one, _⟩ := collinear_iff_finrank_le_one
#align collinear.finrank_le_one Collinear.finrank_le_one
theorem Collinear.subset {s₁ s₂ : Set P} (hs : s₁ ⊆ s₂) (h : Collinear k s₂) : Collinear k s₁ :=
(rank_le_of_submodule (vectorSpan k s₁) (vectorSpan k s₂) (vectorSpan_mono k hs)).trans h
#align collinear.subset Collinear.subset
theorem Collinear.finiteDimensional_vectorSpan {s : Set P} (h : Collinear k s) :
FiniteDimensional k (vectorSpan k s) :=
IsNoetherian.iff_fg.1
(IsNoetherian.iff_rank_lt_aleph0.2 (lt_of_le_of_lt h Cardinal.one_lt_aleph0))
#align collinear.finite_dimensional_vector_span Collinear.finiteDimensional_vectorSpan
theorem Collinear.finiteDimensional_direction_affineSpan {s : Set P} (h : Collinear k s) :
FiniteDimensional k (affineSpan k s).direction :=
(direction_affineSpan k s).symm ▸ h.finiteDimensional_vectorSpan
#align collinear.finite_dimensional_direction_affine_span Collinear.finiteDimensional_direction_affineSpan
variable (k P)
theorem collinear_empty : Collinear k (∅ : Set P) := by
rw [collinear_iff_rank_le_one, vectorSpan_empty]
simp
#align collinear_empty collinear_empty
variable {P}
theorem collinear_singleton (p : P) : Collinear k ({p} : Set P) := by
rw [collinear_iff_rank_le_one, vectorSpan_singleton]
simp
#align collinear_singleton collinear_singleton
variable {k}
theorem collinear_iff_of_mem {s : Set P} {p₀ : P} (h : p₀ ∈ s) :
Collinear k s ↔ ∃ v : V, ∀ p ∈ s, ∃ r : k, p = r • v +ᵥ p₀ := by
simp_rw [collinear_iff_rank_le_one, rank_submodule_le_one_iff', Submodule.le_span_singleton_iff]
constructor
· rintro ⟨v₀, hv⟩
use v₀
intro p hp
obtain ⟨r, hr⟩ := hv (p -ᵥ p₀) (vsub_mem_vectorSpan k hp h)
use r
rw [eq_vadd_iff_vsub_eq]
exact hr.symm
· rintro ⟨v, hp₀v⟩
use v
intro w hw
have hs : vectorSpan k s ≤ k ∙ v := by
rw [vectorSpan_eq_span_vsub_set_right k h, Submodule.span_le, Set.subset_def]
intro x hx
rw [SetLike.mem_coe, Submodule.mem_span_singleton]
rw [Set.mem_image] at hx
rcases hx with ⟨p, hp, rfl⟩
rcases hp₀v p hp with ⟨r, rfl⟩
use r
simp
have hw' := SetLike.le_def.1 hs hw
rwa [Submodule.mem_span_singleton] at hw'
#align collinear_iff_of_mem collinear_iff_of_mem
theorem collinear_iff_exists_forall_eq_smul_vadd (s : Set P) :
Collinear k s ↔ ∃ (p₀ : P) (v : V), ∀ p ∈ s, ∃ r : k, p = r • v +ᵥ p₀ := by
rcases Set.eq_empty_or_nonempty s with (rfl | ⟨⟨p₁, hp₁⟩⟩)
· simp [collinear_empty]
· rw [collinear_iff_of_mem hp₁]
constructor
· exact fun h => ⟨p₁, h⟩
· rintro ⟨p, v, hv⟩
use v
intro p₂ hp₂
rcases hv p₂ hp₂ with ⟨r, rfl⟩
rcases hv p₁ hp₁ with ⟨r₁, rfl⟩
use r - r₁
simp [vadd_vadd, ← add_smul]
#align collinear_iff_exists_forall_eq_smul_vadd collinear_iff_exists_forall_eq_smul_vadd
variable (k)
theorem collinear_pair (p₁ p₂ : P) : Collinear k ({p₁, p₂} : Set P) := by
rw [collinear_iff_exists_forall_eq_smul_vadd]
use p₁, p₂ -ᵥ p₁
intro p hp
rw [Set.mem_insert_iff, Set.mem_singleton_iff] at hp
cases' hp with hp hp
· use 0
simp [hp]
· use 1
simp [hp]
#align collinear_pair collinear_pair
variable {k}
theorem affineIndependent_iff_not_collinear {p : Fin 3 → P} :
AffineIndependent k p ↔ ¬Collinear k (Set.range p) := by
rw [collinear_iff_finrank_le_one,
affineIndependent_iff_not_finrank_vectorSpan_le k p (Fintype.card_fin 3)]
#align affine_independent_iff_not_collinear affineIndependent_iff_not_collinear
theorem collinear_iff_not_affineIndependent {p : Fin 3 → P} :
Collinear k (Set.range p) ↔ ¬AffineIndependent k p := by
rw [collinear_iff_finrank_le_one,
finrank_vectorSpan_le_iff_not_affineIndependent k p (Fintype.card_fin 3)]
#align collinear_iff_not_affine_independent collinear_iff_not_affineIndependent
theorem affineIndependent_iff_not_collinear_set {p₁ p₂ p₃ : P} :
AffineIndependent k ![p₁, p₂, p₃] ↔ ¬Collinear k ({p₁, p₂, p₃} : Set P) := by
rw [affineIndependent_iff_not_collinear]
simp_rw [Matrix.range_cons, Matrix.range_empty, Set.singleton_union, insert_emptyc_eq]
#align affine_independent_iff_not_collinear_set affineIndependent_iff_not_collinear_set
theorem collinear_iff_not_affineIndependent_set {p₁ p₂ p₃ : P} :
Collinear k ({p₁, p₂, p₃} : Set P) ↔ ¬AffineIndependent k ![p₁, p₂, p₃] :=
affineIndependent_iff_not_collinear_set.not_left.symm
#align collinear_iff_not_affine_independent_set collinear_iff_not_affineIndependent_set
theorem affineIndependent_iff_not_collinear_of_ne {p : Fin 3 → P} {i₁ i₂ i₃ : Fin 3} (h₁₂ : i₁ ≠ i₂)
(h₁₃ : i₁ ≠ i₃) (h₂₃ : i₂ ≠ i₃) :
AffineIndependent k p ↔ ¬Collinear k ({p i₁, p i₂, p i₃} : Set P) := by
have hu : (Finset.univ : Finset (Fin 3)) = {i₁, i₂, i₃} := by
-- Porting note: Originally `by decide!`
fin_cases i₁ <;> fin_cases i₂ <;> fin_cases i₃
<;> simp (config := {decide := true}) only at h₁₂ h₁₃ h₂₃ ⊢
rw [affineIndependent_iff_not_collinear, ← Set.image_univ, ← Finset.coe_univ, hu,
Finset.coe_insert, Finset.coe_insert, Finset.coe_singleton, Set.image_insert_eq, Set.image_pair]
#align affine_independent_iff_not_collinear_of_ne affineIndependent_iff_not_collinear_of_ne
theorem collinear_iff_not_affineIndependent_of_ne {p : Fin 3 → P} {i₁ i₂ i₃ : Fin 3} (h₁₂ : i₁ ≠ i₂)
(h₁₃ : i₁ ≠ i₃) (h₂₃ : i₂ ≠ i₃) :
Collinear k ({p i₁, p i₂, p i₃} : Set P) ↔ ¬AffineIndependent k p :=
(affineIndependent_iff_not_collinear_of_ne h₁₂ h₁₃ h₂₃).not_left.symm
#align collinear_iff_not_affine_independent_of_ne collinear_iff_not_affineIndependent_of_ne
theorem ne₁₂_of_not_collinear {p₁ p₂ p₃ : P} (h : ¬Collinear k ({p₁, p₂, p₃} : Set P)) :
p₁ ≠ p₂ := by
rintro rfl
simp [collinear_pair] at h
#align ne₁₂_of_not_collinear ne₁₂_of_not_collinear
theorem ne₁₃_of_not_collinear {p₁ p₂ p₃ : P} (h : ¬Collinear k ({p₁, p₂, p₃} : Set P)) :
p₁ ≠ p₃ := by
rintro rfl
simp [collinear_pair] at h
#align ne₁₃_of_not_collinear ne₁₃_of_not_collinear
theorem ne₂₃_of_not_collinear {p₁ p₂ p₃ : P} (h : ¬Collinear k ({p₁, p₂, p₃} : Set P)) :
p₂ ≠ p₃ := by
rintro rfl
simp [collinear_pair] at h
#align ne₂₃_of_not_collinear ne₂₃_of_not_collinear
theorem Collinear.mem_affineSpan_of_mem_of_ne {s : Set P} (h : Collinear k s) {p₁ p₂ p₃ : P}
(hp₁ : p₁ ∈ s) (hp₂ : p₂ ∈ s) (hp₃ : p₃ ∈ s) (hp₁p₂ : p₁ ≠ p₂) : p₃ ∈ line[k, p₁, p₂] := by
rw [collinear_iff_of_mem hp₁] at h
rcases h with ⟨v, h⟩
rcases h p₂ hp₂ with ⟨r₂, rfl⟩
rcases h p₃ hp₃ with ⟨r₃, rfl⟩
rw [vadd_left_mem_affineSpan_pair]
refine ⟨r₃ / r₂, ?_⟩
have h₂ : r₂ ≠ 0 := by
rintro rfl
simp at hp₁p₂
simp [smul_smul, h₂]
#align collinear.mem_affine_span_of_mem_of_ne Collinear.mem_affineSpan_of_mem_of_ne
theorem Collinear.affineSpan_eq_of_ne {s : Set P} (h : Collinear k s) {p₁ p₂ : P} (hp₁ : p₁ ∈ s)
(hp₂ : p₂ ∈ s) (hp₁p₂ : p₁ ≠ p₂) : line[k, p₁, p₂] = affineSpan k s :=
le_antisymm (affineSpan_mono _ (Set.insert_subset_iff.2 ⟨hp₁, Set.singleton_subset_iff.2 hp₂⟩))
(affineSpan_le.2 fun _ hp => h.mem_affineSpan_of_mem_of_ne hp₁ hp₂ hp hp₁p₂)
#align collinear.affine_span_eq_of_ne Collinear.affineSpan_eq_of_ne
theorem Collinear.collinear_insert_iff_of_ne {s : Set P} (h : Collinear k s) {p₁ p₂ p₃ : P}
(hp₂ : p₂ ∈ s) (hp₃ : p₃ ∈ s) (hp₂p₃ : p₂ ≠ p₃) :
Collinear k (insert p₁ s) ↔ Collinear k ({p₁, p₂, p₃} : Set P) := by
have hv : vectorSpan k (insert p₁ s) = vectorSpan k ({p₁, p₂, p₃} : Set P) := by
-- Porting note: Original proof used `conv_lhs` and `conv_rhs`, but these tactics timed out.
rw [← direction_affineSpan, ← affineSpan_insert_affineSpan]
symm
rw [← direction_affineSpan, ← affineSpan_insert_affineSpan, h.affineSpan_eq_of_ne hp₂ hp₃ hp₂p₃]
rw [Collinear, Collinear, hv]
#align collinear.collinear_insert_iff_of_ne Collinear.collinear_insert_iff_of_ne
theorem collinear_insert_iff_of_mem_affineSpan {s : Set P} {p : P} (h : p ∈ affineSpan k s) :
Collinear k (insert p s) ↔ Collinear k s := by
rw [Collinear, Collinear, vectorSpan_insert_eq_vectorSpan h]
#align collinear_insert_iff_of_mem_affine_span collinear_insert_iff_of_mem_affineSpan
theorem collinear_insert_of_mem_affineSpan_pair {p₁ p₂ p₃ : P} (h : p₁ ∈ line[k, p₂, p₃]) :
Collinear k ({p₁, p₂, p₃} : Set P) := by
rw [collinear_insert_iff_of_mem_affineSpan h]
exact collinear_pair _ _ _
#align collinear_insert_of_mem_affine_span_pair collinear_insert_of_mem_affineSpan_pair
theorem collinear_insert_insert_of_mem_affineSpan_pair {p₁ p₂ p₃ p₄ : P} (h₁ : p₁ ∈ line[k, p₃, p₄])
(h₂ : p₂ ∈ line[k, p₃, p₄]) : Collinear k ({p₁, p₂, p₃, p₄} : Set P) := by
rw [collinear_insert_iff_of_mem_affineSpan
((AffineSubspace.le_def' _ _).1 (affineSpan_mono k (Set.subset_insert _ _)) _ h₁),
collinear_insert_iff_of_mem_affineSpan h₂]
exact collinear_pair _ _ _
#align collinear_insert_insert_of_mem_affine_span_pair collinear_insert_insert_of_mem_affineSpan_pair
theorem collinear_insert_insert_insert_of_mem_affineSpan_pair {p₁ p₂ p₃ p₄ p₅ : P}
(h₁ : p₁ ∈ line[k, p₄, p₅]) (h₂ : p₂ ∈ line[k, p₄, p₅]) (h₃ : p₃ ∈ line[k, p₄, p₅]) :
Collinear k ({p₁, p₂, p₃, p₄, p₅} : Set P) := by
rw [collinear_insert_iff_of_mem_affineSpan
((AffineSubspace.le_def' _ _).1
(affineSpan_mono k ((Set.subset_insert _ _).trans (Set.subset_insert _ _))) _ h₁),
collinear_insert_iff_of_mem_affineSpan
((AffineSubspace.le_def' _ _).1 (affineSpan_mono k (Set.subset_insert _ _)) _ h₂),
collinear_insert_iff_of_mem_affineSpan h₃]
exact collinear_pair _ _ _
#align collinear_insert_insert_insert_of_mem_affine_span_pair collinear_insert_insert_insert_of_mem_affineSpan_pair
theorem collinear_insert_insert_insert_left_of_mem_affineSpan_pair {p₁ p₂ p₃ p₄ p₅ : P}
(h₁ : p₁ ∈ line[k, p₄, p₅]) (h₂ : p₂ ∈ line[k, p₄, p₅]) (h₃ : p₃ ∈ line[k, p₄, p₅]) :
Collinear k ({p₁, p₂, p₃, p₄} : Set P) := by
refine (collinear_insert_insert_insert_of_mem_affineSpan_pair h₁ h₂ h₃).subset ?_
repeat apply Set.insert_subset_insert
simp
#align collinear_insert_insert_insert_left_of_mem_affine_span_pair collinear_insert_insert_insert_left_of_mem_affineSpan_pair
theorem collinear_triple_of_mem_affineSpan_pair {p₁ p₂ p₃ p₄ p₅ : P} (h₁ : p₁ ∈ line[k, p₄, p₅])
(h₂ : p₂ ∈ line[k, p₄, p₅]) (h₃ : p₃ ∈ line[k, p₄, p₅]) :
Collinear k ({p₁, p₂, p₃} : Set P) := by
refine (collinear_insert_insert_insert_left_of_mem_affineSpan_pair h₁ h₂ h₃).subset ?_
simp [Set.insert_subset_insert]
#align collinear_triple_of_mem_affine_span_pair collinear_triple_of_mem_affineSpan_pair
variable (k)
def Coplanar (s : Set P) : Prop :=
Module.rank k (vectorSpan k s) ≤ 2
#align coplanar Coplanar
variable {k}
theorem Coplanar.finiteDimensional_vectorSpan {s : Set P} (h : Coplanar k s) :
FiniteDimensional k (vectorSpan k s) := by
refine IsNoetherian.iff_fg.1 (IsNoetherian.iff_rank_lt_aleph0.2 (lt_of_le_of_lt h ?_))
exact Cardinal.lt_aleph0.2 ⟨2, rfl⟩
#align coplanar.finite_dimensional_vector_span Coplanar.finiteDimensional_vectorSpan
theorem Coplanar.finiteDimensional_direction_affineSpan {s : Set P} (h : Coplanar k s) :
FiniteDimensional k (affineSpan k s).direction :=
(direction_affineSpan k s).symm ▸ h.finiteDimensional_vectorSpan
#align coplanar.finite_dimensional_direction_affine_span Coplanar.finiteDimensional_direction_affineSpan
| Mathlib/LinearAlgebra/AffineSpace/FiniteDimensional.lean | 689 | 693 | theorem coplanar_iff_finrank_le_two {s : Set P} [FiniteDimensional k (vectorSpan k s)] :
Coplanar k s ↔ finrank k (vectorSpan k s) ≤ 2 := by |
have h : Coplanar k s ↔ Module.rank k (vectorSpan k s) ≤ 2 := Iff.rfl
rw [← finrank_eq_rank] at h
exact mod_cast h
|
import Mathlib.Algebra.GroupWithZero.Divisibility
import Mathlib.Algebra.Order.Ring.Nat
import Mathlib.Tactic.NthRewrite
#align_import data.nat.gcd.basic from "leanprover-community/mathlib"@"e8638a0fcaf73e4500469f368ef9494e495099b3"
namespace Nat
theorem gcd_greatest {a b d : ℕ} (hda : d ∣ a) (hdb : d ∣ b) (hd : ∀ e : ℕ, e ∣ a → e ∣ b → e ∣ d) :
d = a.gcd b :=
(dvd_antisymm (hd _ (gcd_dvd_left a b) (gcd_dvd_right a b)) (dvd_gcd hda hdb)).symm
#align nat.gcd_greatest Nat.gcd_greatest
@[simp]
theorem gcd_add_mul_right_right (m n k : ℕ) : gcd m (n + k * m) = gcd m n := by
simp [gcd_rec m (n + k * m), gcd_rec m n]
#align nat.gcd_add_mul_right_right Nat.gcd_add_mul_right_right
@[simp]
theorem gcd_add_mul_left_right (m n k : ℕ) : gcd m (n + m * k) = gcd m n := by
simp [gcd_rec m (n + m * k), gcd_rec m n]
#align nat.gcd_add_mul_left_right Nat.gcd_add_mul_left_right
@[simp]
theorem gcd_mul_right_add_right (m n k : ℕ) : gcd m (k * m + n) = gcd m n := by simp [add_comm _ n]
#align nat.gcd_mul_right_add_right Nat.gcd_mul_right_add_right
@[simp]
theorem gcd_mul_left_add_right (m n k : ℕ) : gcd m (m * k + n) = gcd m n := by simp [add_comm _ n]
#align nat.gcd_mul_left_add_right Nat.gcd_mul_left_add_right
@[simp]
theorem gcd_add_mul_right_left (m n k : ℕ) : gcd (m + k * n) n = gcd m n := by
rw [gcd_comm, gcd_add_mul_right_right, gcd_comm]
#align nat.gcd_add_mul_right_left Nat.gcd_add_mul_right_left
@[simp]
theorem gcd_add_mul_left_left (m n k : ℕ) : gcd (m + n * k) n = gcd m n := by
rw [gcd_comm, gcd_add_mul_left_right, gcd_comm]
#align nat.gcd_add_mul_left_left Nat.gcd_add_mul_left_left
@[simp]
theorem gcd_mul_right_add_left (m n k : ℕ) : gcd (k * n + m) n = gcd m n := by
rw [gcd_comm, gcd_mul_right_add_right, gcd_comm]
#align nat.gcd_mul_right_add_left Nat.gcd_mul_right_add_left
@[simp]
theorem gcd_mul_left_add_left (m n k : ℕ) : gcd (n * k + m) n = gcd m n := by
rw [gcd_comm, gcd_mul_left_add_right, gcd_comm]
#align nat.gcd_mul_left_add_left Nat.gcd_mul_left_add_left
@[simp]
theorem gcd_add_self_right (m n : ℕ) : gcd m (n + m) = gcd m n :=
Eq.trans (by rw [one_mul]) (gcd_add_mul_right_right m n 1)
#align nat.gcd_add_self_right Nat.gcd_add_self_right
@[simp]
theorem gcd_add_self_left (m n : ℕ) : gcd (m + n) n = gcd m n := by
rw [gcd_comm, gcd_add_self_right, gcd_comm]
#align nat.gcd_add_self_left Nat.gcd_add_self_left
@[simp]
theorem gcd_self_add_left (m n : ℕ) : gcd (m + n) m = gcd n m := by rw [add_comm, gcd_add_self_left]
#align nat.gcd_self_add_left Nat.gcd_self_add_left
@[simp]
| Mathlib/Data/Nat/GCD/Basic.lean | 89 | 90 | theorem gcd_self_add_right (m n : ℕ) : gcd m (m + n) = gcd m n := by |
rw [add_comm, gcd_add_self_right]
|
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]
| Mathlib/Order/Interval/Finset/Fin.lean | 84 | 85 | theorem map_valEmbedding_Ico : (Ico a b).map Fin.valEmbedding = Ico ↑a ↑b := by |
simp [Ico_eq_finset_subtype, Finset.fin, Finset.map_map]
|
import Mathlib.Data.Bundle
import Mathlib.Data.Set.Image
import Mathlib.Topology.PartialHomeomorph
import Mathlib.Topology.Order.Basic
#align_import topology.fiber_bundle.trivialization from "leanprover-community/mathlib"@"e473c3198bb41f68560cab68a0529c854b618833"
open TopologicalSpace Filter Set Bundle Function
open scoped Topology Classical Bundle
variable {ι : Type*} {B : Type*} {F : Type*} {E : B → Type*}
variable (F) {Z : Type*} [TopologicalSpace B] [TopologicalSpace F] {proj : Z → B}
structure Pretrivialization (proj : Z → B) extends PartialEquiv Z (B × F) where
open_target : IsOpen target
baseSet : Set B
open_baseSet : IsOpen baseSet
source_eq : source = proj ⁻¹' baseSet
target_eq : target = baseSet ×ˢ univ
proj_toFun : ∀ p ∈ source, (toFun p).1 = proj p
#align pretrivialization Pretrivialization
namespace Pretrivialization
variable {F}
variable (e : Pretrivialization F proj) {x : Z}
@[coe] def toFun' : Z → (B × F) := e.toFun
instance : CoeFun (Pretrivialization F proj) fun _ => Z → B × F := ⟨toFun'⟩
@[ext]
lemma ext' (e e' : Pretrivialization F proj) (h₁ : e.toPartialEquiv = e'.toPartialEquiv)
(h₂ : e.baseSet = e'.baseSet) : e = e' := by
cases e; cases e'; congr
#align pretrivialization.ext Pretrivialization.ext'
-- Porting note (#11215): TODO: move `ext` here?
lemma ext {e e' : Pretrivialization F proj} (h₁ : ∀ x, e x = e' x)
(h₂ : ∀ x, e.toPartialEquiv.symm x = e'.toPartialEquiv.symm x) (h₃ : e.baseSet = e'.baseSet) :
e = e' := by
ext1 <;> [ext1; exact h₃]
· apply h₁
· apply h₂
· rw [e.source_eq, e'.source_eq, h₃]
lemma toPartialEquiv_injective [Nonempty F] :
Injective (toPartialEquiv : Pretrivialization F proj → PartialEquiv Z (B × F)) := by
refine fun e e' h ↦ ext' _ _ h ?_
simpa only [fst_image_prod, univ_nonempty, target_eq]
using congr_arg (Prod.fst '' PartialEquiv.target ·) h
@[simp, mfld_simps]
theorem coe_coe : ⇑e.toPartialEquiv = e :=
rfl
#align pretrivialization.coe_coe Pretrivialization.coe_coe
@[simp, mfld_simps]
theorem coe_fst (ex : x ∈ e.source) : (e x).1 = proj x :=
e.proj_toFun x ex
#align pretrivialization.coe_fst Pretrivialization.coe_fst
theorem mem_source : x ∈ e.source ↔ proj x ∈ e.baseSet := by rw [e.source_eq, mem_preimage]
#align pretrivialization.mem_source Pretrivialization.mem_source
theorem coe_fst' (ex : proj x ∈ e.baseSet) : (e x).1 = proj x :=
e.coe_fst (e.mem_source.2 ex)
#align pretrivialization.coe_fst' Pretrivialization.coe_fst'
protected theorem eqOn : EqOn (Prod.fst ∘ e) proj e.source := fun _ hx => e.coe_fst hx
#align pretrivialization.eq_on Pretrivialization.eqOn
theorem mk_proj_snd (ex : x ∈ e.source) : (proj x, (e x).2) = e x :=
Prod.ext (e.coe_fst ex).symm rfl
#align pretrivialization.mk_proj_snd Pretrivialization.mk_proj_snd
theorem mk_proj_snd' (ex : proj x ∈ e.baseSet) : (proj x, (e x).2) = e x :=
Prod.ext (e.coe_fst' ex).symm rfl
#align pretrivialization.mk_proj_snd' Pretrivialization.mk_proj_snd'
def setSymm : e.target → Z :=
e.target.restrict e.toPartialEquiv.symm
#align pretrivialization.set_symm Pretrivialization.setSymm
theorem mem_target {x : B × F} : x ∈ e.target ↔ x.1 ∈ e.baseSet := by
rw [e.target_eq, prod_univ, mem_preimage]
#align pretrivialization.mem_target Pretrivialization.mem_target
theorem proj_symm_apply {x : B × F} (hx : x ∈ e.target) : proj (e.toPartialEquiv.symm x) = x.1 := by
have := (e.coe_fst (e.map_target hx)).symm
rwa [← e.coe_coe, e.right_inv hx] at this
#align pretrivialization.proj_symm_apply Pretrivialization.proj_symm_apply
theorem proj_symm_apply' {b : B} {x : F} (hx : b ∈ e.baseSet) :
proj (e.toPartialEquiv.symm (b, x)) = b :=
e.proj_symm_apply (e.mem_target.2 hx)
#align pretrivialization.proj_symm_apply' Pretrivialization.proj_symm_apply'
theorem proj_surjOn_baseSet [Nonempty F] : Set.SurjOn proj e.source e.baseSet := fun b hb =>
let ⟨y⟩ := ‹Nonempty F›
⟨e.toPartialEquiv.symm (b, y), e.toPartialEquiv.map_target <| e.mem_target.2 hb,
e.proj_symm_apply' hb⟩
#align pretrivialization.proj_surj_on_base_set Pretrivialization.proj_surjOn_baseSet
theorem apply_symm_apply {x : B × F} (hx : x ∈ e.target) : e (e.toPartialEquiv.symm x) = x :=
e.toPartialEquiv.right_inv hx
#align pretrivialization.apply_symm_apply Pretrivialization.apply_symm_apply
theorem apply_symm_apply' {b : B} {x : F} (hx : b ∈ e.baseSet) :
e (e.toPartialEquiv.symm (b, x)) = (b, x) :=
e.apply_symm_apply (e.mem_target.2 hx)
#align pretrivialization.apply_symm_apply' Pretrivialization.apply_symm_apply'
theorem symm_apply_apply {x : Z} (hx : x ∈ e.source) : e.toPartialEquiv.symm (e x) = x :=
e.toPartialEquiv.left_inv hx
#align pretrivialization.symm_apply_apply Pretrivialization.symm_apply_apply
@[simp, mfld_simps]
theorem symm_apply_mk_proj {x : Z} (ex : x ∈ e.source) :
e.toPartialEquiv.symm (proj x, (e x).2) = x := by
rw [← e.coe_fst ex, ← e.coe_coe, e.left_inv ex]
#align pretrivialization.symm_apply_mk_proj Pretrivialization.symm_apply_mk_proj
@[simp, mfld_simps]
theorem preimage_symm_proj_baseSet :
e.toPartialEquiv.symm ⁻¹' (proj ⁻¹' e.baseSet) ∩ e.target = e.target := by
refine inter_eq_right.mpr fun x hx => ?_
simp only [mem_preimage, PartialEquiv.invFun_as_coe, e.proj_symm_apply hx]
exact e.mem_target.mp hx
#align pretrivialization.preimage_symm_proj_base_set Pretrivialization.preimage_symm_proj_baseSet
@[simp, mfld_simps]
theorem preimage_symm_proj_inter (s : Set B) :
e.toPartialEquiv.symm ⁻¹' (proj ⁻¹' s) ∩ e.baseSet ×ˢ univ = (s ∩ e.baseSet) ×ˢ univ := by
ext ⟨x, y⟩
suffices x ∈ e.baseSet → (proj (e.toPartialEquiv.symm (x, y)) ∈ s ↔ x ∈ s) by
simpa only [prod_mk_mem_set_prod_eq, mem_inter_iff, and_true_iff, mem_univ, and_congr_left_iff]
intro h
rw [e.proj_symm_apply' h]
#align pretrivialization.preimage_symm_proj_inter Pretrivialization.preimage_symm_proj_inter
| Mathlib/Topology/FiberBundle/Trivialization.lean | 198 | 200 | theorem target_inter_preimage_symm_source_eq (e f : Pretrivialization F proj) :
f.target ∩ f.toPartialEquiv.symm ⁻¹' e.source = (e.baseSet ∩ f.baseSet) ×ˢ univ := by |
rw [inter_comm, f.target_eq, e.source_eq, f.preimage_symm_proj_inter]
|
import Mathlib.Probability.ProbabilityMassFunction.Basic
#align_import probability.probability_mass_function.monad from "leanprover-community/mathlib"@"4ac69b290818724c159de091daa3acd31da0ee6d"
noncomputable section
variable {α β γ : Type*}
open scoped Classical
open NNReal ENNReal
open MeasureTheory
namespace PMF
section Pure
def pure (a : α) : PMF α :=
⟨fun a' => if a' = a then 1 else 0, hasSum_ite_eq _ _⟩
#align pmf.pure PMF.pure
variable (a a' : α)
@[simp]
theorem pure_apply : pure a a' = if a' = a then 1 else 0 := rfl
#align pmf.pure_apply PMF.pure_apply
@[simp]
theorem support_pure : (pure a).support = {a} :=
Set.ext fun a' => by simp [mem_support_iff]
#align pmf.support_pure PMF.support_pure
theorem mem_support_pure_iff : a' ∈ (pure a).support ↔ a' = a := by simp
#align pmf.mem_support_pure_iff PMF.mem_support_pure_iff
-- @[simp] -- Porting note (#10618): simp can prove this
theorem pure_apply_self : pure a a = 1 :=
if_pos rfl
#align pmf.pure_apply_self PMF.pure_apply_self
theorem pure_apply_of_ne (h : a' ≠ a) : pure a a' = 0 :=
if_neg h
#align pmf.pure_apply_of_ne PMF.pure_apply_of_ne
instance [Inhabited α] : Inhabited (PMF α) :=
⟨pure default⟩
section Bind
def bind (p : PMF α) (f : α → PMF β) : PMF β :=
⟨fun b => ∑' a, p a * f a b,
ENNReal.summable.hasSum_iff.2
(ENNReal.tsum_comm.trans <| by simp only [ENNReal.tsum_mul_left, tsum_coe, mul_one])⟩
#align pmf.bind PMF.bind
variable (p : PMF α) (f : α → PMF β) (g : β → PMF γ)
@[simp]
theorem bind_apply (b : β) : p.bind f b = ∑' a, p a * f a b := rfl
#align pmf.bind_apply PMF.bind_apply
@[simp]
theorem support_bind : (p.bind f).support = ⋃ a ∈ p.support, (f a).support :=
Set.ext fun b => by simp [mem_support_iff, ENNReal.tsum_eq_zero, not_or]
#align pmf.support_bind PMF.support_bind
theorem mem_support_bind_iff (b : β) :
b ∈ (p.bind f).support ↔ ∃ a ∈ p.support, b ∈ (f a).support := by
simp only [support_bind, Set.mem_iUnion, Set.mem_setOf_eq, exists_prop]
#align pmf.mem_support_bind_iff PMF.mem_support_bind_iff
@[simp]
theorem pure_bind (a : α) (f : α → PMF β) : (pure a).bind f = f a := by
have : ∀ b a', ite (a' = a) (f a' b) 0 = ite (a' = a) (f a b) 0 := fun b a' => by
split_ifs with h <;> simp [h]
ext b
simp [this]
#align pmf.pure_bind PMF.pure_bind
@[simp]
theorem bind_pure : p.bind pure = p :=
PMF.ext fun x => (bind_apply _ _ _).trans (_root_.trans
(tsum_eq_single x fun y hy => by rw [pure_apply_of_ne _ _ hy.symm, mul_zero]) <|
by rw [pure_apply_self, mul_one])
#align pmf.bind_pure PMF.bind_pure
@[simp]
theorem bind_const (p : PMF α) (q : PMF β) : (p.bind fun _ => q) = q :=
PMF.ext fun x => by rw [bind_apply, ENNReal.tsum_mul_right, tsum_coe, one_mul]
#align pmf.bind_const PMF.bind_const
@[simp]
theorem bind_bind : (p.bind f).bind g = p.bind fun a => (f a).bind g :=
PMF.ext fun b => by
simpa only [ENNReal.coe_inj.symm, bind_apply, ENNReal.tsum_mul_left.symm,
ENNReal.tsum_mul_right.symm, mul_assoc, mul_left_comm, mul_comm] using ENNReal.tsum_comm
#align pmf.bind_bind PMF.bind_bind
theorem bind_comm (p : PMF α) (q : PMF β) (f : α → β → PMF γ) :
(p.bind fun a => q.bind (f a)) = q.bind fun b => p.bind fun a => f a b :=
PMF.ext fun b => by
simpa only [ENNReal.coe_inj.symm, bind_apply, ENNReal.tsum_mul_left.symm,
ENNReal.tsum_mul_right.symm, mul_assoc, mul_left_comm, mul_comm] using ENNReal.tsum_comm
#align pmf.bind_comm PMF.bind_comm
section Measure
variable (s : Set β)
@[simp]
| Mathlib/Probability/ProbabilityMassFunction/Monad.lean | 170 | 182 | theorem toOuterMeasure_bind_apply :
(p.bind f).toOuterMeasure s = ∑' a, p a * (f a).toOuterMeasure s :=
calc
(p.bind f).toOuterMeasure s = ∑' b, if b ∈ s then ∑' a, p a * f a b else 0 := by |
simp [toOuterMeasure_apply, Set.indicator_apply]
_ = ∑' (b) (a), p a * if b ∈ s then f a b else 0 := tsum_congr fun b => by split_ifs <;> simp
_ = ∑' (a) (b), p a * if b ∈ s then f a b else 0 :=
(tsum_comm' ENNReal.summable (fun _ => ENNReal.summable) fun _ => ENNReal.summable)
_ = ∑' a, p a * ∑' b, if b ∈ s then f a b else 0 := tsum_congr fun a => ENNReal.tsum_mul_left
_ = ∑' a, p a * ∑' b, if b ∈ s then f a b else 0 :=
(tsum_congr fun a => (congr_arg fun x => p a * x) <| tsum_congr fun b => by split_ifs <;> rfl)
_ = ∑' a, p a * (f a).toOuterMeasure s :=
tsum_congr fun a => by simp only [toOuterMeasure_apply, Set.indicator_apply]
|
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
| Mathlib/Analysis/SpecialFunctions/Trigonometric/Angle.lean | 437 | 440 | 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 _ _
|
import Mathlib.Data.List.Cycle
import Mathlib.GroupTheory.Perm.Cycle.Type
import Mathlib.GroupTheory.Perm.List
#align_import group_theory.perm.cycle.concrete from "leanprover-community/mathlib"@"00638177efd1b2534fc5269363ebf42a7871df9a"
open Equiv Equiv.Perm List
variable {α : Type*}
namespace Equiv.Perm
section Fintype
variable [Fintype α] [DecidableEq α] (p : Equiv.Perm α) (x : α)
def toList : List α :=
(List.range (cycleOf p x).support.card).map fun k => (p ^ k) x
#align equiv.perm.to_list Equiv.Perm.toList
@[simp]
theorem toList_one : toList (1 : Perm α) x = [] := by simp [toList, cycleOf_one]
#align equiv.perm.to_list_one Equiv.Perm.toList_one
@[simp]
theorem toList_eq_nil_iff {p : Perm α} {x} : toList p x = [] ↔ x ∉ p.support := by simp [toList]
#align equiv.perm.to_list_eq_nil_iff Equiv.Perm.toList_eq_nil_iff
@[simp]
theorem length_toList : length (toList p x) = (cycleOf p x).support.card := by simp [toList]
#align equiv.perm.length_to_list Equiv.Perm.length_toList
theorem toList_ne_singleton (y : α) : toList p x ≠ [y] := by
intro H
simpa [card_support_ne_one] using congr_arg length H
#align equiv.perm.to_list_ne_singleton Equiv.Perm.toList_ne_singleton
theorem two_le_length_toList_iff_mem_support {p : Perm α} {x : α} :
2 ≤ length (toList p x) ↔ x ∈ p.support := by simp
#align equiv.perm.two_le_length_to_list_iff_mem_support Equiv.Perm.two_le_length_toList_iff_mem_support
theorem length_toList_pos_of_mem_support (h : x ∈ p.support) : 0 < length (toList p x) :=
zero_lt_two.trans_le (two_le_length_toList_iff_mem_support.mpr h)
#align equiv.perm.length_to_list_pos_of_mem_support Equiv.Perm.length_toList_pos_of_mem_support
theorem get_toList (n : ℕ) (hn : n < length (toList p x)) :
(toList p x).get ⟨n, hn⟩ = (p ^ n) x := by simp [toList]
theorem toList_get_zero (h : x ∈ p.support) :
(toList p x).get ⟨0, (length_toList_pos_of_mem_support _ _ h)⟩ = x := by simp [toList]
set_option linter.deprecated false in
@[deprecated get_toList (since := "2024-05-08")]
theorem nthLe_toList (n : ℕ) (hn : n < length (toList p x)) :
(toList p x).nthLe n hn = (p ^ n) x := by simp [toList]
#align equiv.perm.nth_le_to_list Equiv.Perm.nthLe_toList
set_option linter.deprecated false in
@[deprecated toList_get_zero (since := "2024-05-08")]
theorem toList_nthLe_zero (h : x ∈ p.support) :
(toList p x).nthLe 0 (length_toList_pos_of_mem_support _ _ h) = x := by simp [toList]
#align equiv.perm.to_list_nth_le_zero Equiv.Perm.toList_nthLe_zero
variable {p} {x}
theorem mem_toList_iff {y : α} : y ∈ toList p x ↔ SameCycle p x y ∧ x ∈ p.support := by
simp only [toList, mem_range, mem_map]
constructor
· rintro ⟨n, hx, rfl⟩
refine ⟨⟨n, rfl⟩, ?_⟩
contrapose! hx
rw [← support_cycleOf_eq_nil_iff] at hx
simp [hx]
· rintro ⟨h, hx⟩
simpa using h.exists_pow_eq_of_mem_support hx
#align equiv.perm.mem_to_list_iff Equiv.Perm.mem_toList_iff
set_option linter.deprecated false in
theorem nodup_toList (p : Perm α) (x : α) : Nodup (toList p x) := by
by_cases hx : p x = x
· rw [← not_mem_support, ← toList_eq_nil_iff] at hx
simp [hx]
have hc : IsCycle (cycleOf p x) := isCycle_cycleOf p hx
rw [nodup_iff_nthLe_inj]
rintro n m hn hm
rw [length_toList, ← hc.orderOf] at hm hn
rw [← cycleOf_apply_self, ← Ne, ← mem_support] at hx
rw [nthLe_toList, nthLe_toList, ← cycleOf_pow_apply_self p x n, ←
cycleOf_pow_apply_self p x m]
cases' n with n <;> cases' m with m
· simp
· rw [← hc.support_pow_of_pos_of_lt_orderOf m.zero_lt_succ hm, mem_support,
cycleOf_pow_apply_self] at hx
simp [hx.symm]
· rw [← hc.support_pow_of_pos_of_lt_orderOf n.zero_lt_succ hn, mem_support,
cycleOf_pow_apply_self] at hx
simp [hx]
intro h
have hn' : ¬orderOf (p.cycleOf x) ∣ n.succ := Nat.not_dvd_of_pos_of_lt n.zero_lt_succ hn
have hm' : ¬orderOf (p.cycleOf x) ∣ m.succ := Nat.not_dvd_of_pos_of_lt m.zero_lt_succ hm
rw [← hc.support_pow_eq_iff] at hn' hm'
rw [← Nat.mod_eq_of_lt hn, ← Nat.mod_eq_of_lt hm, ← pow_inj_mod]
refine support_congr ?_ ?_
· rw [hm', hn']
· rw [hm']
intro y hy
obtain ⟨k, rfl⟩ := hc.exists_pow_eq (mem_support.mp hx) (mem_support.mp hy)
rw [← mul_apply, (Commute.pow_pow_self _ _ _).eq, mul_apply, h, ← mul_apply, ← mul_apply,
(Commute.pow_pow_self _ _ _).eq]
#align equiv.perm.nodup_to_list Equiv.Perm.nodup_toList
set_option linter.deprecated false in
theorem next_toList_eq_apply (p : Perm α) (x y : α) (hy : y ∈ toList p x) :
next (toList p x) y hy = p y := by
rw [mem_toList_iff] at hy
obtain ⟨k, hk, hk'⟩ := hy.left.exists_pow_eq_of_mem_support hy.right
rw [← nthLe_toList p x k (by simpa using hk)] at hk'
simp_rw [← hk']
rw [next_nthLe _ (nodup_toList _ _), nthLe_toList, nthLe_toList, ← mul_apply, ← pow_succ',
length_toList, ← pow_mod_orderOf_cycleOf_apply p (k + 1), IsCycle.orderOf]
exact isCycle_cycleOf _ (mem_support.mp hy.right)
#align equiv.perm.next_to_list_eq_apply Equiv.Perm.next_toList_eq_apply
set_option linter.deprecated false in
theorem toList_pow_apply_eq_rotate (p : Perm α) (x : α) (k : ℕ) :
p.toList ((p ^ k) x) = (p.toList x).rotate k := by
apply ext_nthLe
· simp only [length_toList, cycleOf_self_apply_pow, length_rotate]
· intro n hn hn'
rw [nthLe_toList, nthLe_rotate, nthLe_toList, length_toList,
pow_mod_card_support_cycleOf_self_apply, pow_add, mul_apply]
#align equiv.perm.to_list_pow_apply_eq_rotate Equiv.Perm.toList_pow_apply_eq_rotate
theorem SameCycle.toList_isRotated {f : Perm α} {x y : α} (h : SameCycle f x y) :
toList f x ~r toList f y := by
by_cases hx : x ∈ f.support
· obtain ⟨_ | k, _, hy⟩ := h.exists_pow_eq_of_mem_support hx
· simp only [coe_one, id, pow_zero, Nat.zero_eq] at hy
-- Porting note: added `IsRotated.refl`
simp [hy, IsRotated.refl]
use k.succ
rw [← toList_pow_apply_eq_rotate, hy]
· rw [toList_eq_nil_iff.mpr hx, isRotated_nil_iff', eq_comm, toList_eq_nil_iff]
rwa [← h.mem_support_iff]
#align equiv.perm.same_cycle.to_list_is_rotated Equiv.Perm.SameCycle.toList_isRotated
| Mathlib/GroupTheory/Perm/Cycle/Concrete.lean | 346 | 349 | theorem pow_apply_mem_toList_iff_mem_support {n : ℕ} : (p ^ n) x ∈ p.toList x ↔ x ∈ p.support := by |
rw [mem_toList_iff, and_iff_right_iff_imp]
refine fun _ => SameCycle.symm ?_
rw [sameCycle_pow_left]
|
import Mathlib.RingTheory.WittVector.Frobenius
import Mathlib.RingTheory.WittVector.Verschiebung
import Mathlib.RingTheory.WittVector.MulP
#align_import ring_theory.witt_vector.identities from "leanprover-community/mathlib"@"0798037604b2d91748f9b43925fb7570a5f3256c"
namespace WittVector
variable {p : ℕ} {R : Type*} [hp : Fact p.Prime] [CommRing R]
-- type as `\bbW`
local notation "𝕎" => WittVector p
noncomputable section
-- Porting note: `ghost_calc` failure: `simp only []` and the manual instances had to be added.
theorem frobenius_verschiebung (x : 𝕎 R) : frobenius (verschiebung x) = x * p := by
have : IsPoly p fun {R} [CommRing R] x ↦ frobenius (verschiebung x) :=
IsPoly.comp (hg := frobenius_isPoly p) (hf := verschiebung_isPoly)
have : IsPoly p fun {R} [CommRing R] x ↦ x * p := mulN_isPoly p p
ghost_calc x
ghost_simp [mul_comm]
#align witt_vector.frobenius_verschiebung WittVector.frobenius_verschiebung
theorem verschiebung_zmod (x : 𝕎 (ZMod p)) : verschiebung x = x * p := by
rw [← frobenius_verschiebung, frobenius_zmodp]
#align witt_vector.verschiebung_zmod WittVector.verschiebung_zmod
variable (p R)
theorem coeff_p_pow [CharP R p] (i : ℕ) : ((p : 𝕎 R) ^ i).coeff i = 1 := by
induction' i with i h
· simp only [Nat.zero_eq, one_coeff_zero, Ne, pow_zero]
· rw [pow_succ, ← frobenius_verschiebung, coeff_frobenius_charP,
verschiebung_coeff_succ, h, one_pow]
#align witt_vector.coeff_p_pow WittVector.coeff_p_pow
theorem coeff_p_pow_eq_zero [CharP R p] {i j : ℕ} (hj : j ≠ i) : ((p : 𝕎 R) ^ i).coeff j = 0 := by
induction' i with i hi generalizing j
· rw [pow_zero, one_coeff_eq_of_pos]
exact Nat.pos_of_ne_zero hj
· rw [pow_succ, ← frobenius_verschiebung, coeff_frobenius_charP]
cases j
· rw [verschiebung_coeff_zero, zero_pow hp.out.ne_zero]
· rw [verschiebung_coeff_succ, hi (ne_of_apply_ne _ hj), zero_pow hp.out.ne_zero]
#align witt_vector.coeff_p_pow_eq_zero WittVector.coeff_p_pow_eq_zero
theorem coeff_p [CharP R p] (i : ℕ) : (p : 𝕎 R).coeff i = if i = 1 then 1 else 0 := by
split_ifs with hi
· simpa only [hi, pow_one] using coeff_p_pow p R 1
· simpa only [pow_one] using coeff_p_pow_eq_zero p R hi
#align witt_vector.coeff_p WittVector.coeff_p
@[simp]
theorem coeff_p_zero [CharP R p] : (p : 𝕎 R).coeff 0 = 0 := by
rw [coeff_p, if_neg]
exact zero_ne_one
#align witt_vector.coeff_p_zero WittVector.coeff_p_zero
@[simp]
theorem coeff_p_one [CharP R p] : (p : 𝕎 R).coeff 1 = 1 := by rw [coeff_p, if_pos rfl]
#align witt_vector.coeff_p_one WittVector.coeff_p_one
theorem p_nonzero [Nontrivial R] [CharP R p] : (p : 𝕎 R) ≠ 0 := by
intro h
simpa only [h, zero_coeff, zero_ne_one] using coeff_p_one p R
#align witt_vector.p_nonzero WittVector.p_nonzero
theorem FractionRing.p_nonzero [Nontrivial R] [CharP R p] : (p : FractionRing (𝕎 R)) ≠ 0 := by
simpa using (IsFractionRing.injective (𝕎 R) (FractionRing (𝕎 R))).ne (WittVector.p_nonzero _ _)
#align witt_vector.fraction_ring.p_nonzero WittVector.FractionRing.p_nonzero
variable {p R}
-- Porting note: `ghost_calc` failure: `simp only []` and the manual instances had to be added.
theorem verschiebung_mul_frobenius (x y : 𝕎 R) :
verschiebung (x * frobenius y) = verschiebung x * y := by
have : IsPoly₂ p fun {R} [Rcr : CommRing R] x y ↦ verschiebung (x * frobenius y) :=
IsPoly.comp₂ (hg := verschiebung_isPoly)
(hf := IsPoly₂.comp (hh := mulIsPoly₂) (hf := idIsPolyI' p) (hg := frobenius_isPoly p))
have : IsPoly₂ p fun {R} [CommRing R] x y ↦ verschiebung x * y :=
IsPoly₂.comp (hh := mulIsPoly₂) (hf := verschiebung_isPoly) (hg := idIsPolyI' p)
ghost_calc x y
rintro ⟨⟩ <;> ghost_simp [mul_assoc]
#align witt_vector.verschiebung_mul_frobenius WittVector.verschiebung_mul_frobenius
theorem mul_charP_coeff_zero [CharP R p] (x : 𝕎 R) : (x * p).coeff 0 = 0 := by
rw [← frobenius_verschiebung, coeff_frobenius_charP, verschiebung_coeff_zero,
zero_pow hp.out.ne_zero]
#align witt_vector.mul_char_p_coeff_zero WittVector.mul_charP_coeff_zero
theorem mul_charP_coeff_succ [CharP R p] (x : 𝕎 R) (i : ℕ) :
(x * p).coeff (i + 1) = x.coeff i ^ p := by
rw [← frobenius_verschiebung, coeff_frobenius_charP, verschiebung_coeff_succ]
#align witt_vector.mul_char_p_coeff_succ WittVector.mul_charP_coeff_succ
theorem verschiebung_frobenius [CharP R p] (x : 𝕎 R) : verschiebung (frobenius x) = x * p := by
ext ⟨i⟩
· rw [mul_charP_coeff_zero, verschiebung_coeff_zero]
· rw [mul_charP_coeff_succ, verschiebung_coeff_succ, coeff_frobenius_charP]
#align witt_vector.verschiebung_frobenius WittVector.verschiebung_frobenius
theorem verschiebung_frobenius_comm [CharP R p] :
Function.Commute (verschiebung : 𝕎 R → 𝕎 R) frobenius := fun x => by
rw [verschiebung_frobenius, frobenius_verschiebung]
#align witt_vector.verschiebung_frobenius_comm WittVector.verschiebung_frobenius_comm
open Function
theorem iterate_verschiebung_coeff (x : 𝕎 R) (n k : ℕ) :
(verschiebung^[n] x).coeff (k + n) = x.coeff k := by
induction' n with k ih
· simp
· rw [iterate_succ_apply', Nat.add_succ, verschiebung_coeff_succ]
exact ih
#align witt_vector.iterate_verschiebung_coeff WittVector.iterate_verschiebung_coeff
| Mathlib/RingTheory/WittVector/Identities.lean | 150 | 154 | theorem iterate_verschiebung_mul_left (x y : 𝕎 R) (i : ℕ) :
verschiebung^[i] x * y = verschiebung^[i] (x * frobenius^[i] y) := by |
induction' i with i ih generalizing y
· simp
· rw [iterate_succ_apply', ← verschiebung_mul_frobenius, ih, iterate_succ_apply']; rfl
|
import Mathlib.Data.Set.Image
import Mathlib.Order.SuccPred.Relation
import Mathlib.Topology.Clopen
import Mathlib.Topology.Irreducible
#align_import topology.connected from "leanprover-community/mathlib"@"d101e93197bb5f6ea89bd7ba386b7f7dff1f3903"
open Set Function Topology TopologicalSpace Relation
open scoped Classical
universe u v
variable {α : Type u} {β : Type v} {ι : Type*} {π : ι → Type*} [TopologicalSpace α]
{s t u v : Set α}
section Preconnected
def IsPreconnected (s : Set α) : Prop :=
∀ u v : Set α, IsOpen u → IsOpen v → s ⊆ u ∪ v → (s ∩ u).Nonempty → (s ∩ v).Nonempty →
(s ∩ (u ∩ v)).Nonempty
#align is_preconnected IsPreconnected
def IsConnected (s : Set α) : Prop :=
s.Nonempty ∧ IsPreconnected s
#align is_connected IsConnected
theorem IsConnected.nonempty {s : Set α} (h : IsConnected s) : s.Nonempty :=
h.1
#align is_connected.nonempty IsConnected.nonempty
theorem IsConnected.isPreconnected {s : Set α} (h : IsConnected s) : IsPreconnected s :=
h.2
#align is_connected.is_preconnected IsConnected.isPreconnected
theorem IsPreirreducible.isPreconnected {s : Set α} (H : IsPreirreducible s) : IsPreconnected s :=
fun _ _ hu hv _ => H _ _ hu hv
#align is_preirreducible.is_preconnected IsPreirreducible.isPreconnected
theorem IsIrreducible.isConnected {s : Set α} (H : IsIrreducible s) : IsConnected s :=
⟨H.nonempty, H.isPreirreducible.isPreconnected⟩
#align is_irreducible.is_connected IsIrreducible.isConnected
theorem isPreconnected_empty : IsPreconnected (∅ : Set α) :=
isPreirreducible_empty.isPreconnected
#align is_preconnected_empty isPreconnected_empty
theorem isConnected_singleton {x} : IsConnected ({x} : Set α) :=
isIrreducible_singleton.isConnected
#align is_connected_singleton isConnected_singleton
theorem isPreconnected_singleton {x} : IsPreconnected ({x} : Set α) :=
isConnected_singleton.isPreconnected
#align is_preconnected_singleton isPreconnected_singleton
theorem Set.Subsingleton.isPreconnected {s : Set α} (hs : s.Subsingleton) : IsPreconnected s :=
hs.induction_on isPreconnected_empty fun _ => isPreconnected_singleton
#align set.subsingleton.is_preconnected Set.Subsingleton.isPreconnected
theorem isPreconnected_of_forall {s : Set α} (x : α)
(H : ∀ y ∈ s, ∃ t, t ⊆ s ∧ x ∈ t ∧ y ∈ t ∧ IsPreconnected t) : IsPreconnected s := by
rintro u v hu hv hs ⟨z, zs, zu⟩ ⟨y, ys, yv⟩
have xs : x ∈ s := by
rcases H y ys with ⟨t, ts, xt, -, -⟩
exact ts xt
-- Porting note (#11215): TODO: use `wlog xu : x ∈ u := hs xs using u v y z, v u z y`
cases hs xs with
| inl xu =>
rcases H y ys with ⟨t, ts, xt, yt, ht⟩
have := ht u v hu hv (ts.trans hs) ⟨x, xt, xu⟩ ⟨y, yt, yv⟩
exact this.imp fun z hz => ⟨ts hz.1, hz.2⟩
| inr xv =>
rcases H z zs with ⟨t, ts, xt, zt, ht⟩
have := ht v u hv hu (ts.trans <| by rwa [union_comm]) ⟨x, xt, xv⟩ ⟨z, zt, zu⟩
exact this.imp fun _ h => ⟨ts h.1, h.2.2, h.2.1⟩
#align is_preconnected_of_forall isPreconnected_of_forall
| Mathlib/Topology/Connected/Basic.lean | 116 | 120 | theorem isPreconnected_of_forall_pair {s : Set α}
(H : ∀ x ∈ s, ∀ y ∈ s, ∃ t, t ⊆ s ∧ x ∈ t ∧ y ∈ t ∧ IsPreconnected t) :
IsPreconnected s := by |
rcases eq_empty_or_nonempty s with (rfl | ⟨x, hx⟩)
exacts [isPreconnected_empty, isPreconnected_of_forall x fun y => H x hx y]
|
import Mathlib.Data.List.Nodup
#align_import data.list.duplicate from "leanprover-community/mathlib"@"f694c7dead66f5d4c80f446c796a5aad14707f0e"
variable {α : Type*}
namespace List
inductive Duplicate (x : α) : List α → Prop
| cons_mem {l : List α} : x ∈ l → Duplicate x (x :: l)
| cons_duplicate {y : α} {l : List α} : Duplicate x l → Duplicate x (y :: l)
#align list.duplicate List.Duplicate
local infixl:50 " ∈+ " => List.Duplicate
variable {l : List α} {x : α}
theorem Mem.duplicate_cons_self (h : x ∈ l) : x ∈+ x :: l :=
Duplicate.cons_mem h
#align list.mem.duplicate_cons_self List.Mem.duplicate_cons_self
theorem Duplicate.duplicate_cons (h : x ∈+ l) (y : α) : x ∈+ y :: l :=
Duplicate.cons_duplicate h
#align list.duplicate.duplicate_cons List.Duplicate.duplicate_cons
theorem Duplicate.mem (h : x ∈+ l) : x ∈ l := by
induction' h with l' _ y l' _ hm
· exact mem_cons_self _ _
· exact mem_cons_of_mem _ hm
#align list.duplicate.mem List.Duplicate.mem
| Mathlib/Data/List/Duplicate.lean | 52 | 55 | theorem Duplicate.mem_cons_self (h : x ∈+ x :: l) : x ∈ l := by |
cases' h with _ h _ _ h
· exact h
· exact h.mem
|
import Mathlib.Algebra.Group.Subgroup.Finite
import Mathlib.Data.Finset.Fin
import Mathlib.Data.Finset.Sort
import Mathlib.Data.Int.Order.Units
import Mathlib.GroupTheory.Perm.Support
import Mathlib.Logic.Equiv.Fin
import Mathlib.Tactic.NormNum.Ineq
#align_import group_theory.perm.sign from "leanprover-community/mathlib"@"f694c7dead66f5d4c80f446c796a5aad14707f0e"
universe u v
open Equiv Function Fintype Finset
variable {α : Type u} [DecidableEq α] {β : Type v}
namespace Equiv.Perm
def modSwap (i j : α) : Setoid (Perm α) :=
⟨fun σ τ => σ = τ ∨ σ = swap i j * τ, fun σ => Or.inl (refl σ), fun {σ τ} h =>
Or.casesOn h (fun h => Or.inl h.symm) fun h => Or.inr (by rw [h, swap_mul_self_mul]),
fun {σ τ υ} hστ hτυ => by
cases' hστ with hστ hστ <;> cases' hτυ with hτυ hτυ <;> try rw [hστ, hτυ, swap_mul_self_mul] <;>
simp [hστ, hτυ] -- Porting note: should close goals, but doesn't
· simp [hστ, hτυ]
· simp [hστ, hτυ]
· simp [hστ, hτυ]⟩
#align equiv.perm.mod_swap Equiv.Perm.modSwap
noncomputable instance {α : Type*} [Fintype α] [DecidableEq α] (i j : α) :
DecidableRel (modSwap i j).r :=
fun _ _ => Or.decidable
def swapFactorsAux :
∀ (l : List α) (f : Perm α),
(∀ {x}, f x ≠ x → x ∈ l) → { l : List (Perm α) // l.prod = f ∧ ∀ g ∈ l, IsSwap g }
| [] => fun f h =>
⟨[],
Equiv.ext fun x => by
rw [List.prod_nil]
exact (Classical.not_not.1 (mt h (List.not_mem_nil _))).symm,
by simp⟩
| x::l => fun f h =>
if hfx : x = f x then
swapFactorsAux l f fun {y} hy =>
List.mem_of_ne_of_mem (fun h : y = x => by simp [h, hfx.symm] at hy) (h hy)
else
let m :=
swapFactorsAux l (swap x (f x) * f) fun {y} hy =>
have : f y ≠ y ∧ y ≠ x := ne_and_ne_of_swap_mul_apply_ne_self hy
List.mem_of_ne_of_mem this.2 (h this.1)
⟨swap x (f x)::m.1, by
rw [List.prod_cons, m.2.1, ← mul_assoc, mul_def (swap x (f x)), swap_swap, ← one_def,
one_mul],
fun {g} hg => ((List.mem_cons).1 hg).elim (fun h => ⟨x, f x, hfx, h⟩) (m.2.2 _)⟩
#align equiv.perm.swap_factors_aux Equiv.Perm.swapFactorsAux
def swapFactors [Fintype α] [LinearOrder α] (f : Perm α) :
{ l : List (Perm α) // l.prod = f ∧ ∀ g ∈ l, IsSwap g } :=
swapFactorsAux ((@univ α _).sort (· ≤ ·)) f fun {_ _} => (mem_sort _).2 (mem_univ _)
#align equiv.perm.swap_factors Equiv.Perm.swapFactors
def truncSwapFactors [Fintype α] (f : Perm α) :
Trunc { l : List (Perm α) // l.prod = f ∧ ∀ g ∈ l, IsSwap g } :=
Quotient.recOnSubsingleton (@univ α _).1 (fun l h => Trunc.mk (swapFactorsAux l f (h _)))
(show ∀ x, f x ≠ x → x ∈ (@univ α _).1 from fun _ _ => mem_univ _)
#align equiv.perm.trunc_swap_factors Equiv.Perm.truncSwapFactors
@[elab_as_elim]
theorem swap_induction_on [Finite α] {P : Perm α → Prop} (f : Perm α) :
P 1 → (∀ f x y, x ≠ y → P f → P (swap x y * f)) → P f := by
cases nonempty_fintype α
cases' (truncSwapFactors f).out with l hl
induction' l with g l ih generalizing f
· simp (config := { contextual := true }) only [hl.left.symm, List.prod_nil, forall_true_iff]
· intro h1 hmul_swap
rcases hl.2 g (by simp) with ⟨x, y, hxy⟩
rw [← hl.1, List.prod_cons, hxy.2]
exact
hmul_swap _ _ _ hxy.1
(ih _ ⟨rfl, fun v hv => hl.2 _ (List.mem_cons_of_mem _ hv)⟩ h1 hmul_swap)
#align equiv.perm.swap_induction_on Equiv.Perm.swap_induction_on
theorem closure_isSwap [Finite α] : Subgroup.closure { σ : Perm α | IsSwap σ } = ⊤ := by
cases nonempty_fintype α
refine eq_top_iff.mpr fun x _ => ?_
obtain ⟨h1, h2⟩ := Subtype.mem (truncSwapFactors x).out
rw [← h1]
exact Subgroup.list_prod_mem _ fun y hy => Subgroup.subset_closure (h2 y hy)
#align equiv.perm.closure_is_swap Equiv.Perm.closure_isSwap
@[elab_as_elim]
theorem swap_induction_on' [Finite α] {P : Perm α → Prop} (f : Perm α) :
P 1 → (∀ f x y, x ≠ y → P f → P (f * swap x y)) → P f := fun h1 IH =>
inv_inv f ▸ swap_induction_on f⁻¹ h1 fun f => IH f⁻¹
#align equiv.perm.swap_induction_on' Equiv.Perm.swap_induction_on'
theorem isConj_swap {w x y z : α} (hwx : w ≠ x) (hyz : y ≠ z) : IsConj (swap w x) (swap y z) :=
isConj_iff.2
(have h :
∀ {y z : α},
y ≠ z → w ≠ z → swap w y * swap x z * swap w x * (swap w y * swap x z)⁻¹ = swap y z :=
fun {y z} hyz hwz => by
rw [mul_inv_rev, swap_inv, swap_inv, mul_assoc (swap w y), mul_assoc (swap w y), ←
mul_assoc _ (swap x z), swap_mul_swap_mul_swap hwx hwz, ← mul_assoc,
swap_mul_swap_mul_swap hwz.symm hyz.symm]
if hwz : w = z then
have hwy : w ≠ y := by rw [hwz]; exact hyz.symm
⟨swap w z * swap x y, by rw [swap_comm y z, h hyz.symm hwy]⟩
else ⟨swap w y * swap x z, h hyz hwz⟩)
#align equiv.perm.is_conj_swap Equiv.Perm.isConj_swap
def finPairsLT (n : ℕ) : Finset (Σ_ : Fin n, Fin n) :=
(univ : Finset (Fin n)).sigma fun a => (range a).attachFin fun _ hm => (mem_range.1 hm).trans a.2
#align equiv.perm.fin_pairs_lt Equiv.Perm.finPairsLT
theorem mem_finPairsLT {n : ℕ} {a : Σ_ : Fin n, Fin n} : a ∈ finPairsLT n ↔ a.2 < a.1 := by
simp only [finPairsLT, Fin.lt_iff_val_lt_val, true_and_iff, mem_attachFin, mem_range, mem_univ,
mem_sigma]
#align equiv.perm.mem_fin_pairs_lt Equiv.Perm.mem_finPairsLT
def signAux {n : ℕ} (a : Perm (Fin n)) : ℤˣ :=
∏ x ∈ finPairsLT n, if a x.1 ≤ a x.2 then -1 else 1
#align equiv.perm.sign_aux Equiv.Perm.signAux
@[simp]
theorem signAux_one (n : ℕ) : signAux (1 : Perm (Fin n)) = 1 := by
unfold signAux
conv => rhs; rw [← @Finset.prod_const_one _ _ (finPairsLT n)]
exact Finset.prod_congr rfl fun a ha => if_neg (mem_finPairsLT.1 ha).not_le
#align equiv.perm.sign_aux_one Equiv.Perm.signAux_one
def signBijAux {n : ℕ} (f : Perm (Fin n)) (a : Σ_ : Fin n, Fin n) : Σ_ : Fin n, Fin n :=
if _ : f a.2 < f a.1 then ⟨f a.1, f a.2⟩ else ⟨f a.2, f a.1⟩
#align equiv.perm.sign_bij_aux Equiv.Perm.signBijAux
theorem signBijAux_injOn {n : ℕ} {f : Perm (Fin n)} :
(finPairsLT n : Set (Σ _, Fin n)).InjOn (signBijAux f) := by
rintro ⟨a₁, a₂⟩ ha ⟨b₁, b₂⟩ hb h
dsimp [signBijAux] at h
rw [Finset.mem_coe, mem_finPairsLT] at *
have : ¬b₁ < b₂ := hb.le.not_lt
split_ifs at h <;>
simp_all [(Equiv.injective f).eq_iff, eq_self_iff_true, and_self_iff, heq_iff_eq]
· exact absurd this (not_le.mpr ha)
· exact absurd this (not_le.mpr ha)
#align equiv.perm.sign_bij_aux_inj Equiv.Perm.signBijAux_injOn
theorem signBijAux_surj {n : ℕ} {f : Perm (Fin n)} :
∀ a ∈ finPairsLT n, ∃ b ∈ finPairsLT n, signBijAux f b = a :=
fun ⟨a₁, a₂⟩ ha =>
if hxa : f⁻¹ a₂ < f⁻¹ a₁ then
⟨⟨f⁻¹ a₁, f⁻¹ a₂⟩, mem_finPairsLT.2 hxa, by
dsimp [signBijAux]
rw [apply_inv_self, apply_inv_self, if_pos (mem_finPairsLT.1 ha)]⟩
else
⟨⟨f⁻¹ a₂, f⁻¹ a₁⟩,
mem_finPairsLT.2 <|
(le_of_not_gt hxa).lt_of_ne fun h => by
simp [mem_finPairsLT, f⁻¹.injective h, lt_irrefl] at ha, by
dsimp [signBijAux]
rw [apply_inv_self, apply_inv_self, if_neg (mem_finPairsLT.1 ha).le.not_lt]⟩
#align equiv.perm.sign_bij_aux_surj Equiv.Perm.signBijAux_surj
theorem signBijAux_mem {n : ℕ} {f : Perm (Fin n)} :
∀ a : Σ_ : Fin n, Fin n, a ∈ finPairsLT n → signBijAux f a ∈ finPairsLT n :=
fun ⟨a₁, a₂⟩ ha => by
unfold signBijAux
split_ifs with h
· exact mem_finPairsLT.2 h
· exact mem_finPairsLT.2
((le_of_not_gt h).lt_of_ne fun h => (mem_finPairsLT.1 ha).ne (f.injective h.symm))
#align equiv.perm.sign_bij_aux_mem Equiv.Perm.signBijAux_mem
@[simp]
theorem signAux_inv {n : ℕ} (f : Perm (Fin n)) : signAux f⁻¹ = signAux f :=
prod_nbij (signBijAux f⁻¹) signBijAux_mem signBijAux_injOn signBijAux_surj fun ⟨a, b⟩ hab ↦
if h : f⁻¹ b < f⁻¹ a then by
simp_all [signBijAux, dif_pos h, if_neg h.not_le, apply_inv_self, apply_inv_self,
if_neg (mem_finPairsLT.1 hab).not_le]
else by
simp_all [signBijAux, if_pos (le_of_not_gt h), dif_neg h, apply_inv_self, apply_inv_self,
if_pos (mem_finPairsLT.1 hab).le]
#align equiv.perm.sign_aux_inv Equiv.Perm.signAux_inv
theorem signAux_mul {n : ℕ} (f g : Perm (Fin n)) : signAux (f * g) = signAux f * signAux g := by
rw [← signAux_inv g]
unfold signAux
rw [← prod_mul_distrib]
refine prod_nbij (signBijAux g) signBijAux_mem signBijAux_injOn signBijAux_surj ?_
rintro ⟨a, b⟩ hab
dsimp only [signBijAux]
rw [mul_apply, mul_apply]
rw [mem_finPairsLT] at hab
by_cases h : g b < g a
· rw [dif_pos h]
simp only [not_le_of_gt hab, mul_one, mul_ite, mul_neg, Perm.inv_apply_self, if_false]
· rw [dif_neg h, inv_apply_self, inv_apply_self, if_pos hab.le]
by_cases h₁ : f (g b) ≤ f (g a)
· have : f (g b) ≠ f (g a) := by
rw [Ne, f.injective.eq_iff, g.injective.eq_iff]
exact ne_of_lt hab
rw [if_pos h₁, if_neg (h₁.lt_of_ne this).not_le]
rfl
· rw [if_neg h₁, if_pos (lt_of_not_ge h₁).le]
rfl
#align equiv.perm.sign_aux_mul Equiv.Perm.signAux_mul
private theorem signAux_swap_zero_one' (n : ℕ) : signAux (swap (0 : Fin (n + 2)) 1) = -1 :=
show _ = ∏ x ∈ {(⟨1, 0⟩ : Σ a : Fin (n + 2), Fin (n + 2))},
if (Equiv.swap 0 1) x.1 ≤ swap 0 1 x.2 then (-1 : ℤˣ) else 1 by
refine Eq.symm (prod_subset (fun ⟨x₁, x₂⟩ => by
simp (config := { contextual := true }) [mem_finPairsLT, Fin.one_pos]) fun a ha₁ ha₂ => ?_)
rcases a with ⟨a₁, a₂⟩
replace ha₁ : a₂ < a₁ := mem_finPairsLT.1 ha₁
dsimp only
rcases a₁.zero_le.eq_or_lt with (rfl | H)
· exact absurd a₂.zero_le ha₁.not_le
rcases a₂.zero_le.eq_or_lt with (rfl | H')
· simp only [and_true_iff, eq_self_iff_true, heq_iff_eq, mem_singleton, Sigma.mk.inj_iff] at ha₂
have : 1 < a₁ := lt_of_le_of_ne (Nat.succ_le_of_lt ha₁)
(Ne.symm (by intro h; apply ha₂; simp [h]))
have h01 : Equiv.swap (0 : Fin (n + 2)) 1 0 = 1 := by simp
rw [swap_apply_of_ne_of_ne (ne_of_gt H) ha₂, h01, if_neg this.not_le]
· have le : 1 ≤ a₂ := Nat.succ_le_of_lt H'
have lt : 1 < a₁ := le.trans_lt ha₁
have h01 : Equiv.swap (0 : Fin (n + 2)) 1 1 = 0 := by simp only [swap_apply_right]
rcases le.eq_or_lt with (rfl | lt')
· rw [swap_apply_of_ne_of_ne H.ne' lt.ne', h01, if_neg H.not_le]
· rw [swap_apply_of_ne_of_ne (ne_of_gt H) (ne_of_gt lt),
swap_apply_of_ne_of_ne (ne_of_gt H') (ne_of_gt lt'), if_neg ha₁.not_le]
private theorem signAux_swap_zero_one {n : ℕ} (hn : 2 ≤ n) :
signAux (swap (⟨0, lt_of_lt_of_le (by decide) hn⟩ : Fin n) ⟨1, lt_of_lt_of_le (by decide) hn⟩) =
-1 := by
rcases n with (_ | _ | n)
· norm_num at hn
· norm_num at hn
· exact signAux_swap_zero_one' n
theorem signAux_swap : ∀ {n : ℕ} {x y : Fin n} (_hxy : x ≠ y), signAux (swap x y) = -1
| 0, x, y => by intro; exact Fin.elim0 x
| 1, x, y => by
dsimp [signAux, swap, swapCore]
simp only [eq_iff_true_of_subsingleton, not_true, ite_true, le_refl, prod_const,
IsEmpty.forall_iff]
| n + 2, x, y => fun hxy => by
have h2n : 2 ≤ n + 2 := by exact le_add_self
rw [← isConj_iff_eq, ← signAux_swap_zero_one h2n]
exact (MonoidHom.mk' signAux signAux_mul).map_isConj
(isConj_swap hxy (by exact of_decide_eq_true rfl))
#align equiv.perm.sign_aux_swap Equiv.Perm.signAux_swap
def signAux2 : List α → Perm α → ℤˣ
| [], _ => 1
| x::l, f => if x = f x then signAux2 l f else -signAux2 l (swap x (f x) * f)
#align equiv.perm.sign_aux2 Equiv.Perm.signAux2
theorem signAux_eq_signAux2 {n : ℕ} :
∀ (l : List α) (f : Perm α) (e : α ≃ Fin n) (_h : ∀ x, f x ≠ x → x ∈ l),
signAux ((e.symm.trans f).trans e) = signAux2 l f
| [], f, e, h => by
have : f = 1 := Equiv.ext fun y => Classical.not_not.1 (mt (h y) (List.not_mem_nil _))
rw [this, one_def, Equiv.trans_refl, Equiv.symm_trans_self, ← one_def, signAux_one, signAux2]
| x::l, f, e, h => by
rw [signAux2]
by_cases hfx : x = f x
· rw [if_pos hfx]
exact
signAux_eq_signAux2 l f _ fun y (hy : f y ≠ y) =>
List.mem_of_ne_of_mem (fun h : y = x => by simp [h, hfx.symm] at hy) (h y hy)
· have hy : ∀ y : α, (swap x (f x) * f) y ≠ y → y ∈ l := fun y hy =>
have : f y ≠ y ∧ y ≠ x := ne_and_ne_of_swap_mul_apply_ne_self hy
List.mem_of_ne_of_mem this.2 (h _ this.1)
have : (e.symm.trans (swap x (f x) * f)).trans e =
swap (e x) (e (f x)) * (e.symm.trans f).trans e := by
ext
rw [← Equiv.symm_trans_swap_trans, mul_def, Equiv.symm_trans_swap_trans, mul_def]
repeat (rw [trans_apply])
simp [swap, swapCore]
split_ifs <;> rfl
have hefx : e x ≠ e (f x) := mt e.injective.eq_iff.1 hfx
rw [if_neg hfx, ← signAux_eq_signAux2 _ _ e hy, this, signAux_mul, signAux_swap hefx]
simp only [neg_neg, one_mul, neg_mul]
#align equiv.perm.sign_aux_eq_sign_aux2 Equiv.Perm.signAux_eq_signAux2
def signAux3 [Finite α] (f : Perm α) {s : Multiset α} : (∀ x, x ∈ s) → ℤˣ :=
Quotient.hrecOn s (fun l _ => signAux2 l f) fun l₁ l₂ h ↦ by
rcases Finite.exists_equiv_fin α with ⟨n, ⟨e⟩⟩
refine Function.hfunext (forall_congr fun _ ↦ propext h.mem_iff) fun h₁ h₂ _ ↦ ?_
rw [← signAux_eq_signAux2 _ _ e fun _ _ => h₁ _, ← signAux_eq_signAux2 _ _ e fun _ _ => h₂ _]
#align equiv.perm.sign_aux3 Equiv.Perm.signAux3
theorem signAux3_mul_and_swap [Finite α] (f g : Perm α) (s : Multiset α) (hs : ∀ x, x ∈ s) :
signAux3 (f * g) hs = signAux3 f hs * signAux3 g hs ∧
Pairwise fun x y => signAux3 (swap x y) hs = -1 := by
obtain ⟨n, ⟨e⟩⟩ := Finite.exists_equiv_fin α
induction s using Quotient.inductionOn with | _ l => ?_
show
signAux2 l (f * g) = signAux2 l f * signAux2 l g ∧
Pairwise fun x y => signAux2 l (swap x y) = -1
have hfg : (e.symm.trans (f * g)).trans e = (e.symm.trans f).trans e * (e.symm.trans g).trans e :=
Equiv.ext fun h => by simp [mul_apply]
constructor
· rw [← signAux_eq_signAux2 _ _ e fun _ _ => hs _, ←
signAux_eq_signAux2 _ _ e fun _ _ => hs _, ← signAux_eq_signAux2 _ _ e fun _ _ => hs _,
hfg, signAux_mul]
· intro x y hxy
rw [← e.injective.ne_iff] at hxy
rw [← signAux_eq_signAux2 _ _ e fun _ _ => hs _, symm_trans_swap_trans, signAux_swap hxy]
#align equiv.perm.sign_aux3_mul_and_swap Equiv.Perm.signAux3_mul_and_swap
theorem signAux3_symm_trans_trans [Finite α] [DecidableEq β] [Finite β] (f : Perm α) (e : α ≃ β)
{s : Multiset α} {t : Multiset β} (hs : ∀ x, x ∈ s) (ht : ∀ x, x ∈ t) :
signAux3 ((e.symm.trans f).trans e) ht = signAux3 f hs := by
-- Porting note: switched from term mode to tactic mode
induction' t, s using Quotient.inductionOn₂ with t s ht hs
show signAux2 _ _ = signAux2 _ _
rcases Finite.exists_equiv_fin β with ⟨n, ⟨e'⟩⟩
rw [← signAux_eq_signAux2 _ _ e' fun _ _ => ht _,
← signAux_eq_signAux2 _ _ (e.trans e') fun _ _ => hs _]
exact congr_arg signAux
(Equiv.ext fun x => by simp [Equiv.coe_trans, apply_eq_iff_eq, symm_trans_apply])
#align equiv.perm.sign_aux3_symm_trans_trans Equiv.Perm.signAux3_symm_trans_trans
def sign [Fintype α] : Perm α →* ℤˣ :=
MonoidHom.mk' (fun f => signAux3 f mem_univ) fun f g => (signAux3_mul_and_swap f g _ mem_univ).1
#align equiv.perm.sign Equiv.Perm.sign
section SignType.sign
variable [Fintype α]
--@[simp] Porting note (#10618): simp can prove
theorem sign_mul (f g : Perm α) : sign (f * g) = sign f * sign g :=
MonoidHom.map_mul sign f g
#align equiv.perm.sign_mul Equiv.Perm.sign_mul
@[simp]
theorem sign_trans (f g : Perm α) : sign (f.trans g) = sign g * sign f := by
rw [← mul_def, sign_mul]
#align equiv.perm.sign_trans Equiv.Perm.sign_trans
--@[simp] Porting note (#10618): simp can prove
theorem sign_one : sign (1 : Perm α) = 1 :=
MonoidHom.map_one sign
#align equiv.perm.sign_one Equiv.Perm.sign_one
@[simp]
theorem sign_refl : sign (Equiv.refl α) = 1 :=
MonoidHom.map_one sign
#align equiv.perm.sign_refl Equiv.Perm.sign_refl
--@[simp] Porting note (#10618): simp can prove
theorem sign_inv (f : Perm α) : sign f⁻¹ = sign f := by
rw [MonoidHom.map_inv sign f, Int.units_inv_eq_self]
#align equiv.perm.sign_inv Equiv.Perm.sign_inv
@[simp]
theorem sign_symm (e : Perm α) : sign e.symm = sign e :=
sign_inv e
#align equiv.perm.sign_symm Equiv.Perm.sign_symm
theorem sign_swap {x y : α} (h : x ≠ y) : sign (swap x y) = -1 :=
(signAux3_mul_and_swap 1 1 _ mem_univ).2 h
#align equiv.perm.sign_swap Equiv.Perm.sign_swap
@[simp]
theorem sign_swap' {x y : α} : sign (swap x y) = if x = y then 1 else -1 :=
if H : x = y then by simp [H, swap_self] else by simp [sign_swap H, H]
#align equiv.perm.sign_swap' Equiv.Perm.sign_swap'
theorem IsSwap.sign_eq {f : Perm α} (h : f.IsSwap) : sign f = -1 :=
let ⟨_, _, hxy⟩ := h
hxy.2.symm ▸ sign_swap hxy.1
#align equiv.perm.is_swap.sign_eq Equiv.Perm.IsSwap.sign_eq
@[simp]
theorem sign_symm_trans_trans [DecidableEq β] [Fintype β] (f : Perm α) (e : α ≃ β) :
sign ((e.symm.trans f).trans e) = sign f :=
signAux3_symm_trans_trans f e mem_univ mem_univ
#align equiv.perm.sign_symm_trans_trans Equiv.Perm.sign_symm_trans_trans
@[simp]
theorem sign_trans_trans_symm [DecidableEq β] [Fintype β] (f : Perm β) (e : α ≃ β) :
sign ((e.trans f).trans e.symm) = sign f :=
sign_symm_trans_trans f e.symm
#align equiv.perm.sign_trans_trans_symm Equiv.Perm.sign_trans_trans_symm
theorem sign_prod_list_swap {l : List (Perm α)} (hl : ∀ g ∈ l, IsSwap g) :
sign l.prod = (-1) ^ l.length := by
have h₁ : l.map sign = List.replicate l.length (-1) :=
List.eq_replicate.2
⟨by simp, fun u hu =>
let ⟨g, hg⟩ := List.mem_map.1 hu
hg.2 ▸ (hl _ hg.1).sign_eq⟩
rw [← List.prod_replicate, ← h₁, List.prod_hom _ (@sign α _ _)]
#align equiv.perm.sign_prod_list_swap Equiv.Perm.sign_prod_list_swap
variable (α)
theorem sign_surjective [Nontrivial α] : Function.Surjective (sign : Perm α → ℤˣ) := fun a =>
(Int.units_eq_one_or a).elim (fun h => ⟨1, by simp [h]⟩) fun h =>
let ⟨x, y, hxy⟩ := exists_pair_ne α
⟨swap x y, by rw [sign_swap hxy, h]⟩
#align equiv.perm.sign_surjective Equiv.Perm.sign_surjective
variable {α}
theorem eq_sign_of_surjective_hom {s : Perm α →* ℤˣ} (hs : Surjective s) : s = sign :=
have : ∀ {f}, IsSwap f → s f = -1 := fun {f} ⟨x, y, hxy, hxy'⟩ =>
hxy'.symm ▸
by_contradiction fun h => by
have : ∀ f, IsSwap f → s f = 1 := fun f ⟨a, b, hab, hab'⟩ => by
rw [← isConj_iff_eq, ← Or.resolve_right (Int.units_eq_one_or _) h, hab']
exact s.map_isConj (isConj_swap hab hxy)
let ⟨g, hg⟩ := hs (-1)
let ⟨l, hl⟩ := (truncSwapFactors g).out
have : ∀ a ∈ l.map s, a = (1 : ℤˣ) := fun a ha =>
let ⟨g, hg⟩ := List.mem_map.1 ha
hg.2 ▸ this _ (hl.2 _ hg.1)
have : s l.prod = 1 := by
rw [← l.prod_hom s, List.eq_replicate_length.2 this, List.prod_replicate, one_pow]
rw [hl.1, hg] at this
exact absurd this (by simp_all)
MonoidHom.ext fun f => by
let ⟨l, hl₁, hl₂⟩ := (truncSwapFactors f).out
have hsl : ∀ a ∈ l.map s, a = (-1 : ℤˣ) := fun a ha =>
let ⟨g, hg⟩ := List.mem_map.1 ha
hg.2 ▸ this (hl₂ _ hg.1)
rw [← hl₁, ← l.prod_hom s, List.eq_replicate_length.2 hsl, List.length_map, List.prod_replicate,
sign_prod_list_swap hl₂]
#align equiv.perm.eq_sign_of_surjective_hom Equiv.Perm.eq_sign_of_surjective_hom
theorem sign_subtypePerm (f : Perm α) {p : α → Prop} [DecidablePred p] (h₁ : ∀ x, p x ↔ p (f x))
(h₂ : ∀ x, f x ≠ x → p x) : sign (subtypePerm f h₁) = sign f := by
let l := (truncSwapFactors (subtypePerm f h₁)).out
have hl' : ∀ g' ∈ l.1.map ofSubtype, IsSwap g' := fun g' hg' =>
let ⟨g, hg⟩ := List.mem_map.1 hg'
hg.2 ▸ (l.2.2 _ hg.1).of_subtype_isSwap
have hl'₂ : (l.1.map ofSubtype).prod = f := by
rw [l.1.prod_hom ofSubtype, l.2.1, ofSubtype_subtypePerm _ h₂]
conv =>
congr
rw [← l.2.1]
simp_rw [← hl'₂]
rw [sign_prod_list_swap l.2.2, sign_prod_list_swap hl', List.length_map]
#align equiv.perm.sign_subtype_perm Equiv.Perm.sign_subtypePerm
theorem sign_eq_sign_of_equiv [DecidableEq β] [Fintype β] (f : Perm α) (g : Perm β) (e : α ≃ β)
(h : ∀ x, e (f x) = g (e x)) : sign f = sign g := by
have hg : g = (e.symm.trans f).trans e := Equiv.ext <| by simp [h]
rw [hg, sign_symm_trans_trans]
#align equiv.perm.sign_eq_sign_of_equiv Equiv.Perm.sign_eq_sign_of_equiv
theorem sign_bij [DecidableEq β] [Fintype β] {f : Perm α} {g : Perm β} (i : ∀ x : α, f x ≠ x → β)
(h : ∀ x hx hx', i (f x) hx' = g (i x hx)) (hi : ∀ x₁ x₂ hx₁ hx₂, i x₁ hx₁ = i x₂ hx₂ → x₁ = x₂)
(hg : ∀ y, g y ≠ y → ∃ x hx, i x hx = y) : sign f = sign g :=
calc
sign f = sign (subtypePerm f <| by simp : Perm { x // f x ≠ x }) :=
(sign_subtypePerm _ _ fun _ => id).symm
_ = sign (subtypePerm g <| by simp : Perm { x // g x ≠ x }) :=
sign_eq_sign_of_equiv _ _
(Equiv.ofBijective
(fun x : { x // f x ≠ x } =>
(⟨i x.1 x.2, by
have : f (f x) ≠ f x := mt (fun h => f.injective h) x.2
rw [← h _ x.2 this]
exact mt (hi _ _ this x.2) x.2⟩ :
{ y // g y ≠ y }))
⟨fun ⟨x, hx⟩ ⟨y, hy⟩ h => Subtype.eq (hi _ _ _ _ (Subtype.mk.inj h)), fun ⟨y, hy⟩ =>
let ⟨x, hfx, hx⟩ := hg y hy
⟨⟨x, hfx⟩, Subtype.eq hx⟩⟩)
fun ⟨x, _⟩ => Subtype.eq (h x _ _)
_ = sign g := sign_subtypePerm _ _ fun _ => id
#align equiv.perm.sign_bij Equiv.Perm.sign_bij
theorem prod_prodExtendRight {α : Type*} [DecidableEq α] (σ : α → Perm β) {l : List α}
(hl : l.Nodup) (mem_l : ∀ a, a ∈ l) :
(l.map fun a => prodExtendRight a (σ a)).prod = prodCongrRight σ := by
ext ⟨a, b⟩ : 1
-- We'll use induction on the list of elements,
-- but we have to keep track of whether we already passed `a` in the list.
suffices a ∈ l ∧ (l.map fun a => prodExtendRight a (σ a)).prod (a, b) = (a, σ a b) ∨
a ∉ l ∧ (l.map fun a => prodExtendRight a (σ a)).prod (a, b) = (a, b) by
obtain ⟨_, prod_eq⟩ := Or.resolve_right this (not_and.mpr fun h _ => h (mem_l a))
rw [prod_eq, prodCongrRight_apply]
clear mem_l
induction' l with a' l ih
· refine Or.inr ⟨List.not_mem_nil _, ?_⟩
rw [List.map_nil, List.prod_nil, one_apply]
rw [List.map_cons, List.prod_cons, mul_apply]
rcases ih (List.nodup_cons.mp hl).2 with (⟨mem_l, prod_eq⟩ | ⟨not_mem_l, prod_eq⟩) <;>
rw [prod_eq]
· refine Or.inl ⟨List.mem_cons_of_mem _ mem_l, ?_⟩
rw [prodExtendRight_apply_ne _ fun h : a = a' => (List.nodup_cons.mp hl).1 (h ▸ mem_l)]
by_cases ha' : a = a'
· rw [← ha'] at *
refine Or.inl ⟨l.mem_cons_self a, ?_⟩
rw [prodExtendRight_apply_eq]
· refine Or.inr ⟨fun h => not_or_of_not ha' not_mem_l ((List.mem_cons).mp h), ?_⟩
rw [prodExtendRight_apply_ne _ ha']
#align equiv.perm.prod_prod_extend_right Equiv.Perm.prod_prodExtendRight
section congr
variable [DecidableEq β] [Fintype β]
@[simp]
theorem sign_prodExtendRight (a : α) (σ : Perm β) : sign (prodExtendRight a σ) = sign σ :=
sign_bij (fun (ab : α × β) _ => ab.snd)
(fun ⟨a', b⟩ hab _ => by simp [eq_of_prodExtendRight_ne hab])
(fun ⟨a₁, b₁⟩ ⟨a₂, b₂⟩ hab₁ hab₂ h => by
simpa [eq_of_prodExtendRight_ne hab₁, eq_of_prodExtendRight_ne hab₂] using h)
fun y hy => ⟨(a, y), by simpa, by simp⟩
#align equiv.perm.sign_prod_extend_right Equiv.Perm.sign_prodExtendRight
theorem sign_prodCongrRight (σ : α → Perm β) : sign (prodCongrRight σ) = ∏ k, sign (σ k) := by
obtain ⟨l, hl, mem_l⟩ := Finite.exists_univ_list α
have l_to_finset : l.toFinset = Finset.univ := by
apply eq_top_iff.mpr
intro b _
exact List.mem_toFinset.mpr (mem_l b)
rw [← prod_prodExtendRight σ hl mem_l, map_list_prod sign, List.map_map, ← l_to_finset,
List.prod_toFinset _ hl]
simp_rw [← fun a => sign_prodExtendRight a (σ a), Function.comp]
#align equiv.perm.sign_prod_congr_right Equiv.Perm.sign_prodCongrRight
theorem sign_prodCongrLeft (σ : α → Perm β) : sign (prodCongrLeft σ) = ∏ k, sign (σ k) := by
refine (sign_eq_sign_of_equiv _ _ (prodComm β α) ?_).trans (sign_prodCongrRight σ)
rintro ⟨b, α⟩
rfl
#align equiv.perm.sign_prod_congr_left Equiv.Perm.sign_prodCongrLeft
@[simp]
theorem sign_permCongr (e : α ≃ β) (p : Perm α) : sign (e.permCongr p) = sign p :=
sign_eq_sign_of_equiv _ _ e.symm (by simp)
#align equiv.perm.sign_perm_congr Equiv.Perm.sign_permCongr
@[simp]
| Mathlib/GroupTheory/Perm/Sign.lean | 587 | 598 | theorem sign_sumCongr (σa : Perm α) (σb : Perm β) : sign (sumCongr σa σb) = sign σa * sign σb := by |
suffices sign (sumCongr σa (1 : Perm β)) = sign σa ∧ sign (sumCongr (1 : Perm α) σb) = sign σb
by rw [← this.1, ← this.2, ← sign_mul, sumCongr_mul, one_mul, mul_one]
constructor
· refine σa.swap_induction_on ?_ fun σa' a₁ a₂ ha ih => ?_
· simp
· rw [← one_mul (1 : Perm β), ← sumCongr_mul, sign_mul, sign_mul, ih, sumCongr_swap_one,
sign_swap ha, sign_swap (Sum.inl_injective.ne_iff.mpr ha)]
· refine σb.swap_induction_on ?_ fun σb' b₁ b₂ hb ih => ?_
· simp
· rw [← one_mul (1 : Perm α), ← sumCongr_mul, sign_mul, sign_mul, ih, sumCongr_one_swap,
sign_swap hb, sign_swap (Sum.inr_injective.ne_iff.mpr hb)]
|
import Mathlib.CategoryTheory.Limits.Shapes.Equalizers
import Mathlib.CategoryTheory.Limits.Shapes.Products
import Mathlib.Topology.Sheaves.SheafCondition.PairwiseIntersections
#align_import topology.sheaves.sheaf_condition.equalizer_products from "leanprover-community/mathlib"@"85d6221d32c37e68f05b2e42cde6cee658dae5e9"
universe v' v u
noncomputable section
open CategoryTheory CategoryTheory.Limits TopologicalSpace Opposite TopologicalSpace.Opens
namespace TopCat
variable {C : Type u} [Category.{v} C] [HasProducts.{v'} C]
variable {X : TopCat.{v'}} (F : Presheaf C X) {ι : Type v'} (U : ι → Opens X)
namespace Presheaf
namespace SheafConditionEqualizerProducts
def piOpens : C :=
∏ᶜ fun i : ι => F.obj (op (U i))
set_option linter.uppercaseLean3 false in
#align Top.presheaf.sheaf_condition_equalizer_products.pi_opens TopCat.Presheaf.SheafConditionEqualizerProducts.piOpens
def piInters : C :=
∏ᶜ fun p : ι × ι => F.obj (op (U p.1 ⊓ U p.2))
set_option linter.uppercaseLean3 false in
#align Top.presheaf.sheaf_condition_equalizer_products.pi_inters TopCat.Presheaf.SheafConditionEqualizerProducts.piInters
def leftRes : piOpens F U ⟶ piInters.{v'} F U :=
Pi.lift fun p : ι × ι => Pi.π _ p.1 ≫ F.map (infLELeft (U p.1) (U p.2)).op
set_option linter.uppercaseLean3 false in
#align Top.presheaf.sheaf_condition_equalizer_products.left_res TopCat.Presheaf.SheafConditionEqualizerProducts.leftRes
def rightRes : piOpens F U ⟶ piInters.{v'} F U :=
Pi.lift fun p : ι × ι => Pi.π _ p.2 ≫ F.map (infLERight (U p.1) (U p.2)).op
set_option linter.uppercaseLean3 false in
#align Top.presheaf.sheaf_condition_equalizer_products.right_res TopCat.Presheaf.SheafConditionEqualizerProducts.rightRes
def res : F.obj (op (iSup U)) ⟶ piOpens.{v'} F U :=
Pi.lift fun i : ι => F.map (TopologicalSpace.Opens.leSupr U i).op
set_option linter.uppercaseLean3 false in
#align Top.presheaf.sheaf_condition_equalizer_products.res TopCat.Presheaf.SheafConditionEqualizerProducts.res
@[simp, elementwise]
theorem res_π (i : ι) : res F U ≫ limit.π _ ⟨i⟩ = F.map (Opens.leSupr U i).op := by
rw [res, limit.lift_π, Fan.mk_π_app]
set_option linter.uppercaseLean3 false in
#align Top.presheaf.sheaf_condition_equalizer_products.res_π TopCat.Presheaf.SheafConditionEqualizerProducts.res_π
@[elementwise]
| Mathlib/Topology/Sheaves/SheafCondition/EqualizerProducts.lean | 86 | 94 | theorem w : res F U ≫ leftRes F U = res F U ≫ rightRes F U := by |
dsimp [res, leftRes, rightRes]
-- Porting note: `ext` can't see `limit.hom_ext` applies here:
-- See https://github.com/leanprover-community/mathlib4/issues/5229
refine limit.hom_ext (fun _ => ?_)
simp only [limit.lift_π, limit.lift_π_assoc, Fan.mk_π_app, Category.assoc]
rw [← F.map_comp]
rw [← F.map_comp]
congr 1
|
import Mathlib.Algebra.Group.Equiv.TypeTags
import Mathlib.GroupTheory.FreeAbelianGroup
import Mathlib.GroupTheory.FreeGroup.IsFreeGroup
import Mathlib.LinearAlgebra.Dimension.StrongRankCondition
#align_import group_theory.free_abelian_group_finsupp from "leanprover-community/mathlib"@"47b51515e69f59bca5cf34ef456e6000fe205a69"
noncomputable section
variable {X : Type*}
def FreeAbelianGroup.toFinsupp : FreeAbelianGroup X →+ X →₀ ℤ :=
FreeAbelianGroup.lift fun x => Finsupp.single x (1 : ℤ)
#align free_abelian_group.to_finsupp FreeAbelianGroup.toFinsupp
def Finsupp.toFreeAbelianGroup : (X →₀ ℤ) →+ FreeAbelianGroup X :=
Finsupp.liftAddHom fun x => (smulAddHom ℤ (FreeAbelianGroup X)).flip (FreeAbelianGroup.of x)
#align finsupp.to_free_abelian_group Finsupp.toFreeAbelianGroup
open Finsupp FreeAbelianGroup
@[simp]
theorem Finsupp.toFreeAbelianGroup_comp_singleAddHom (x : X) :
Finsupp.toFreeAbelianGroup.comp (Finsupp.singleAddHom x) =
(smulAddHom ℤ (FreeAbelianGroup X)).flip (of x) := by
ext
simp only [AddMonoidHom.coe_comp, Finsupp.singleAddHom_apply, Function.comp_apply, one_smul,
toFreeAbelianGroup, Finsupp.liftAddHom_apply_single]
#align finsupp.to_free_abelian_group_comp_single_add_hom Finsupp.toFreeAbelianGroup_comp_singleAddHom
@[simp]
theorem FreeAbelianGroup.toFinsupp_comp_toFreeAbelianGroup :
toFinsupp.comp toFreeAbelianGroup = AddMonoidHom.id (X →₀ ℤ) := by
ext x y; simp only [AddMonoidHom.id_comp]
rw [AddMonoidHom.comp_assoc, Finsupp.toFreeAbelianGroup_comp_singleAddHom]
simp only [toFinsupp, AddMonoidHom.coe_comp, Finsupp.singleAddHom_apply, Function.comp_apply,
one_smul, lift.of, AddMonoidHom.flip_apply, smulAddHom_apply, AddMonoidHom.id_apply]
#align free_abelian_group.to_finsupp_comp_to_free_abelian_group FreeAbelianGroup.toFinsupp_comp_toFreeAbelianGroup
@[simp]
| Mathlib/GroupTheory/FreeAbelianGroupFinsupp.lean | 63 | 68 | theorem Finsupp.toFreeAbelianGroup_comp_toFinsupp :
toFreeAbelianGroup.comp toFinsupp = AddMonoidHom.id (FreeAbelianGroup X) := by |
ext
rw [toFreeAbelianGroup, toFinsupp, AddMonoidHom.comp_apply, lift.of,
liftAddHom_apply_single, AddMonoidHom.flip_apply, smulAddHom_apply, one_smul,
AddMonoidHom.id_apply]
|
import Mathlib.Analysis.NormedSpace.OperatorNorm.Basic
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]
[NormedSpace 𝕜 Gₗ] {σ₁₂ : 𝕜 →+* 𝕜₂} {σ₂₃ : 𝕜₂ →+* 𝕜₃} {σ₁₃ : 𝕜 →+* 𝕜₃}
[RingHomCompTriple σ₁₂ σ₂₃ σ₁₃]
variable [FunLike 𝓕 E F]
namespace ContinuousLinearMap
section OpNorm
open Set Real
section
variable [RingHomIsometric σ₁₂] [RingHomIsometric σ₂₃] (f g : E →SL[σ₁₂] F) (h : F →SL[σ₂₃] G)
(x : E)
theorem nnnorm_def (f : E →SL[σ₁₂] F) : ‖f‖₊ = sInf { c | ∀ x, ‖f x‖₊ ≤ c * ‖x‖₊ } := by
ext
rw [NNReal.coe_sInf, coe_nnnorm, norm_def, NNReal.coe_image]
simp_rw [← NNReal.coe_le_coe, NNReal.coe_mul, coe_nnnorm, mem_setOf_eq, NNReal.coe_mk,
exists_prop]
#align continuous_linear_map.nnnorm_def ContinuousLinearMap.nnnorm_def
theorem opNNNorm_le_bound (f : E →SL[σ₁₂] F) (M : ℝ≥0) (hM : ∀ x, ‖f x‖₊ ≤ M * ‖x‖₊) : ‖f‖₊ ≤ M :=
opNorm_le_bound f (zero_le M) hM
#align continuous_linear_map.op_nnnorm_le_bound ContinuousLinearMap.opNNNorm_le_bound
@[deprecated (since := "2024-02-02")] alias op_nnnorm_le_bound := opNNNorm_le_bound
theorem opNNNorm_le_bound' (f : E →SL[σ₁₂] F) (M : ℝ≥0) (hM : ∀ x, ‖x‖₊ ≠ 0 → ‖f x‖₊ ≤ M * ‖x‖₊) :
‖f‖₊ ≤ M :=
opNorm_le_bound' f (zero_le M) fun x hx => hM x <| by rwa [← NNReal.coe_ne_zero]
#align continuous_linear_map.op_nnnorm_le_bound' ContinuousLinearMap.opNNNorm_le_bound'
@[deprecated (since := "2024-02-02")] alias op_nnnorm_le_bound' := opNNNorm_le_bound'
theorem opNNNorm_le_of_unit_nnnorm [NormedSpace ℝ E] [NormedSpace ℝ F] {f : E →L[ℝ] F} {C : ℝ≥0}
(hf : ∀ x, ‖x‖₊ = 1 → ‖f x‖₊ ≤ C) : ‖f‖₊ ≤ C :=
opNorm_le_of_unit_norm C.coe_nonneg fun x hx => hf x <| by rwa [← NNReal.coe_eq_one]
#align continuous_linear_map.op_nnnorm_le_of_unit_nnnorm ContinuousLinearMap.opNNNorm_le_of_unit_nnnorm
@[deprecated (since := "2024-02-02")]
alias op_nnnorm_le_of_unit_nnnorm := opNNNorm_le_of_unit_nnnorm
theorem opNNNorm_le_of_lipschitz {f : E →SL[σ₁₂] F} {K : ℝ≥0} (hf : LipschitzWith K f) :
‖f‖₊ ≤ K :=
opNorm_le_of_lipschitz hf
#align continuous_linear_map.op_nnnorm_le_of_lipschitz ContinuousLinearMap.opNNNorm_le_of_lipschitz
@[deprecated (since := "2024-02-02")] alias op_nnnorm_le_of_lipschitz := opNNNorm_le_of_lipschitz
theorem opNNNorm_eq_of_bounds {φ : E →SL[σ₁₂] F} (M : ℝ≥0) (h_above : ∀ x, ‖φ x‖₊ ≤ M * ‖x‖₊)
(h_below : ∀ N, (∀ x, ‖φ x‖₊ ≤ N * ‖x‖₊) → M ≤ N) : ‖φ‖₊ = M :=
Subtype.ext <| opNorm_eq_of_bounds (zero_le M) h_above <| Subtype.forall'.mpr h_below
#align continuous_linear_map.op_nnnorm_eq_of_bounds ContinuousLinearMap.opNNNorm_eq_of_bounds
@[deprecated (since := "2024-02-02")] alias op_nnnorm_eq_of_bounds := opNNNorm_eq_of_bounds
theorem opNNNorm_le_iff {f : E →SL[σ₁₂] F} {C : ℝ≥0} : ‖f‖₊ ≤ C ↔ ∀ x, ‖f x‖₊ ≤ C * ‖x‖₊ :=
opNorm_le_iff C.2
@[deprecated (since := "2024-02-02")] alias op_nnnorm_le_iff := opNNNorm_le_iff
theorem isLeast_opNNNorm : IsLeast {C : ℝ≥0 | ∀ x, ‖f x‖₊ ≤ C * ‖x‖₊} ‖f‖₊ := by
simpa only [← opNNNorm_le_iff] using isLeast_Ici
@[deprecated (since := "2024-02-02")] alias isLeast_op_nnnorm := isLeast_opNNNorm
theorem opNNNorm_comp_le [RingHomIsometric σ₁₃] (f : E →SL[σ₁₂] F) : ‖h.comp f‖₊ ≤ ‖h‖₊ * ‖f‖₊ :=
opNorm_comp_le h f
#align continuous_linear_map.op_nnnorm_comp_le ContinuousLinearMap.opNNNorm_comp_le
@[deprecated (since := "2024-02-02")] alias op_nnnorm_comp_le := opNNNorm_comp_le
theorem le_opNNNorm : ‖f x‖₊ ≤ ‖f‖₊ * ‖x‖₊ :=
f.le_opNorm x
#align continuous_linear_map.le_op_nnnorm ContinuousLinearMap.le_opNNNorm
@[deprecated (since := "2024-02-02")] alias le_op_nnnorm := le_opNNNorm
theorem nndist_le_opNNNorm (x y : E) : nndist (f x) (f y) ≤ ‖f‖₊ * nndist x y :=
dist_le_opNorm f x y
#align continuous_linear_map.nndist_le_op_nnnorm ContinuousLinearMap.nndist_le_opNNNorm
@[deprecated (since := "2024-02-02")] alias nndist_le_op_nnnorm := nndist_le_opNNNorm
theorem lipschitz : LipschitzWith ‖f‖₊ f :=
AddMonoidHomClass.lipschitz_of_bound_nnnorm f _ f.le_opNNNorm
#align continuous_linear_map.lipschitz ContinuousLinearMap.lipschitz
theorem lipschitz_apply (x : E) : LipschitzWith ‖x‖₊ fun f : E →SL[σ₁₂] F => f x :=
lipschitzWith_iff_norm_sub_le.2 fun f g => ((f - g).le_opNorm x).trans_eq (mul_comm _ _)
#align continuous_linear_map.lipschitz_apply ContinuousLinearMap.lipschitz_apply
end
section Sup
variable [RingHomIsometric σ₁₂]
theorem exists_mul_lt_apply_of_lt_opNNNorm (f : E →SL[σ₁₂] F) {r : ℝ≥0} (hr : r < ‖f‖₊) :
∃ x, r * ‖x‖₊ < ‖f x‖₊ := by
simpa only [not_forall, not_le, Set.mem_setOf] using
not_mem_of_lt_csInf (nnnorm_def f ▸ hr : r < sInf { c : ℝ≥0 | ∀ x, ‖f x‖₊ ≤ c * ‖x‖₊ })
(OrderBot.bddBelow _)
#align continuous_linear_map.exists_mul_lt_apply_of_lt_op_nnnorm ContinuousLinearMap.exists_mul_lt_apply_of_lt_opNNNorm
@[deprecated (since := "2024-02-02")]
alias exists_mul_lt_apply_of_lt_op_nnnorm := exists_mul_lt_apply_of_lt_opNNNorm
theorem exists_mul_lt_of_lt_opNorm (f : E →SL[σ₁₂] F) {r : ℝ} (hr₀ : 0 ≤ r) (hr : r < ‖f‖) :
∃ x, r * ‖x‖ < ‖f x‖ := by
lift r to ℝ≥0 using hr₀
exact f.exists_mul_lt_apply_of_lt_opNNNorm hr
#align continuous_linear_map.exists_mul_lt_of_lt_op_norm ContinuousLinearMap.exists_mul_lt_of_lt_opNorm
@[deprecated (since := "2024-02-02")]
alias exists_mul_lt_of_lt_op_norm := exists_mul_lt_of_lt_opNorm
theorem exists_lt_apply_of_lt_opNNNorm {𝕜 𝕜₂ E F : Type*} [NormedAddCommGroup E]
[SeminormedAddCommGroup F] [DenselyNormedField 𝕜] [NontriviallyNormedField 𝕜₂] {σ₁₂ : 𝕜 →+* 𝕜₂}
[NormedSpace 𝕜 E] [NormedSpace 𝕜₂ F] [RingHomIsometric σ₁₂] (f : E →SL[σ₁₂] F) {r : ℝ≥0}
(hr : r < ‖f‖₊) : ∃ x : E, ‖x‖₊ < 1 ∧ r < ‖f x‖₊ := by
obtain ⟨y, hy⟩ := f.exists_mul_lt_apply_of_lt_opNNNorm hr
have hy' : ‖y‖₊ ≠ 0 :=
nnnorm_ne_zero_iff.2 fun heq => by
simp [heq, nnnorm_zero, map_zero, not_lt_zero'] at hy
have hfy : ‖f y‖₊ ≠ 0 := (zero_le'.trans_lt hy).ne'
rw [← inv_inv ‖f y‖₊, NNReal.lt_inv_iff_mul_lt (inv_ne_zero hfy), mul_assoc, mul_comm ‖y‖₊, ←
mul_assoc, ← NNReal.lt_inv_iff_mul_lt hy'] at hy
obtain ⟨k, hk₁, hk₂⟩ := NormedField.exists_lt_nnnorm_lt 𝕜 hy
refine ⟨k • y, (nnnorm_smul k y).symm ▸ (NNReal.lt_inv_iff_mul_lt hy').1 hk₂, ?_⟩
have : ‖σ₁₂ k‖₊ = ‖k‖₊ := Subtype.ext RingHomIsometric.is_iso
rwa [map_smulₛₗ f, nnnorm_smul, ← NNReal.div_lt_iff hfy, div_eq_mul_inv, this]
#align continuous_linear_map.exists_lt_apply_of_lt_op_nnnorm ContinuousLinearMap.exists_lt_apply_of_lt_opNNNorm
@[deprecated (since := "2024-02-02")]
alias exists_lt_apply_of_lt_op_nnnorm := exists_lt_apply_of_lt_opNNNorm
theorem exists_lt_apply_of_lt_opNorm {𝕜 𝕜₂ E F : Type*} [NormedAddCommGroup E]
[SeminormedAddCommGroup F] [DenselyNormedField 𝕜] [NontriviallyNormedField 𝕜₂] {σ₁₂ : 𝕜 →+* 𝕜₂}
[NormedSpace 𝕜 E] [NormedSpace 𝕜₂ F] [RingHomIsometric σ₁₂] (f : E →SL[σ₁₂] F) {r : ℝ}
(hr : r < ‖f‖) : ∃ x : E, ‖x‖ < 1 ∧ r < ‖f x‖ := by
by_cases hr₀ : r < 0
· exact ⟨0, by simpa using hr₀⟩
· lift r to ℝ≥0 using not_lt.1 hr₀
exact f.exists_lt_apply_of_lt_opNNNorm hr
#align continuous_linear_map.exists_lt_apply_of_lt_op_norm ContinuousLinearMap.exists_lt_apply_of_lt_opNorm
@[deprecated (since := "2024-02-02")]
alias exists_lt_apply_of_lt_op_norm := exists_lt_apply_of_lt_opNorm
| Mathlib/Analysis/NormedSpace/OperatorNorm/NNNorm.lean | 191 | 200 | theorem sSup_unit_ball_eq_nnnorm {𝕜 𝕜₂ E F : Type*} [NormedAddCommGroup E]
[SeminormedAddCommGroup F] [DenselyNormedField 𝕜] [NontriviallyNormedField 𝕜₂] {σ₁₂ : 𝕜 →+* 𝕜₂}
[NormedSpace 𝕜 E] [NormedSpace 𝕜₂ F] [RingHomIsometric σ₁₂] (f : E →SL[σ₁₂] F) :
sSup ((fun x => ‖f x‖₊) '' ball 0 1) = ‖f‖₊ := by |
refine csSup_eq_of_forall_le_of_forall_lt_exists_gt ((nonempty_ball.mpr zero_lt_one).image _) ?_
fun ub hub => ?_
· rintro - ⟨x, hx, rfl⟩
simpa only [mul_one] using f.le_opNorm_of_le (mem_ball_zero_iff.1 hx).le
· obtain ⟨x, hx, hxf⟩ := f.exists_lt_apply_of_lt_opNNNorm hub
exact ⟨_, ⟨x, mem_ball_zero_iff.2 hx, rfl⟩, hxf⟩
|
import Mathlib.LinearAlgebra.Dimension.Free
import Mathlib.Algebra.Module.Torsion
#align_import linear_algebra.dimension from "leanprover-community/mathlib"@"47a5f8186becdbc826190ced4312f8199f9db6a5"
noncomputable section
universe u v v' u₁' w w'
variable {R S : Type u} {M : Type v} {M' : Type v'} {M₁ : Type v}
variable {ι : Type w} {ι' : Type w'} {η : Type u₁'} {φ : η → Type*}
open Cardinal Basis Submodule Function Set FiniteDimensional DirectSum
variable [Ring R] [CommRing S] [AddCommGroup M] [AddCommGroup M'] [AddCommGroup M₁]
variable [Module R M] [Module R M'] [Module R M₁]
section Finsupp
variable (R M M')
variable [StrongRankCondition R] [Module.Free R M] [Module.Free R M']
open Module.Free
@[simp]
theorem rank_finsupp (ι : Type w) :
Module.rank R (ι →₀ M) = Cardinal.lift.{v} #ι * Cardinal.lift.{w} (Module.rank R M) := by
obtain ⟨⟨_, bs⟩⟩ := Module.Free.exists_basis (R := R) (M := M)
rw [← bs.mk_eq_rank'', ← (Finsupp.basis fun _ : ι => bs).mk_eq_rank'', Cardinal.mk_sigma,
Cardinal.sum_const]
#align rank_finsupp rank_finsupp
theorem rank_finsupp' (ι : Type v) : Module.rank R (ι →₀ M) = #ι * Module.rank R M := by
simp [rank_finsupp]
#align rank_finsupp' rank_finsupp'
-- Porting note, this should not be `@[simp]`, as simp can prove it.
-- @[simp]
theorem rank_finsupp_self (ι : Type w) : Module.rank R (ι →₀ R) = Cardinal.lift.{u} #ι := by
simp [rank_finsupp]
#align rank_finsupp_self rank_finsupp_self
theorem rank_finsupp_self' {ι : Type u} : Module.rank R (ι →₀ R) = #ι := by simp
#align rank_finsupp_self' rank_finsupp_self'
@[simp]
theorem rank_directSum {ι : Type v} (M : ι → Type w) [∀ i : ι, AddCommGroup (M i)]
[∀ i : ι, Module R (M i)] [∀ i : ι, Module.Free R (M i)] :
Module.rank R (⨁ i, M i) = Cardinal.sum fun i => Module.rank R (M i) := by
let B i := chooseBasis R (M i)
let b : Basis _ R (⨁ i, M i) := DFinsupp.basis fun i => B i
simp [← b.mk_eq_rank'', fun i => (B i).mk_eq_rank'']
#align rank_direct_sum rank_directSum
@[simp]
| Mathlib/LinearAlgebra/Dimension/Constructions.lean | 198 | 205 | theorem rank_matrix (m : Type v) (n : Type w) [Finite m] [Finite n] :
Module.rank R (Matrix m n R) =
Cardinal.lift.{max v w u, v} #m * Cardinal.lift.{max v w u, w} #n := by |
cases nonempty_fintype m
cases nonempty_fintype n
have h := (Matrix.stdBasis R m n).mk_eq_rank
rw [← lift_lift.{max v w u, max v w}, lift_inj] at h
simpa using h.symm
|
import Mathlib.Order.Cover
import Mathlib.Order.Interval.Finset.Defs
#align_import data.finset.locally_finite from "leanprover-community/mathlib"@"442a83d738cb208d3600056c489be16900ba701d"
assert_not_exists MonoidWithZero
assert_not_exists Finset.sum
open Function OrderDual
open FinsetInterval
variable {ι α : Type*}
namespace Finset
section Preorder
variable [Preorder α]
section LocallyFiniteOrder
variable [LocallyFiniteOrder α] {a a₁ a₂ b b₁ b₂ c x : α}
@[simp, aesop safe apply (rule_sets := [finsetNonempty])]
theorem nonempty_Icc : (Icc a b).Nonempty ↔ a ≤ b := by
rw [← coe_nonempty, coe_Icc, Set.nonempty_Icc]
#align finset.nonempty_Icc Finset.nonempty_Icc
@[simp, aesop safe apply (rule_sets := [finsetNonempty])]
theorem nonempty_Ico : (Ico a b).Nonempty ↔ a < b := by
rw [← coe_nonempty, coe_Ico, Set.nonempty_Ico]
#align finset.nonempty_Ico Finset.nonempty_Ico
@[simp, aesop safe apply (rule_sets := [finsetNonempty])]
theorem nonempty_Ioc : (Ioc a b).Nonempty ↔ a < b := by
rw [← coe_nonempty, coe_Ioc, Set.nonempty_Ioc]
#align finset.nonempty_Ioc Finset.nonempty_Ioc
-- TODO: This is nonsense. A locally finite order is never densely ordered
@[simp]
theorem nonempty_Ioo [DenselyOrdered α] : (Ioo a b).Nonempty ↔ a < b := by
rw [← coe_nonempty, coe_Ioo, Set.nonempty_Ioo]
#align finset.nonempty_Ioo Finset.nonempty_Ioo
@[simp]
theorem Icc_eq_empty_iff : Icc a b = ∅ ↔ ¬a ≤ b := by
rw [← coe_eq_empty, coe_Icc, Set.Icc_eq_empty_iff]
#align finset.Icc_eq_empty_iff Finset.Icc_eq_empty_iff
@[simp]
theorem Ico_eq_empty_iff : Ico a b = ∅ ↔ ¬a < b := by
rw [← coe_eq_empty, coe_Ico, Set.Ico_eq_empty_iff]
#align finset.Ico_eq_empty_iff Finset.Ico_eq_empty_iff
@[simp]
theorem Ioc_eq_empty_iff : Ioc a b = ∅ ↔ ¬a < b := by
rw [← coe_eq_empty, coe_Ioc, Set.Ioc_eq_empty_iff]
#align finset.Ioc_eq_empty_iff Finset.Ioc_eq_empty_iff
-- TODO: This is nonsense. A locally finite order is never densely ordered
@[simp]
theorem Ioo_eq_empty_iff [DenselyOrdered α] : Ioo a b = ∅ ↔ ¬a < b := by
rw [← coe_eq_empty, coe_Ioo, Set.Ioo_eq_empty_iff]
#align finset.Ioo_eq_empty_iff Finset.Ioo_eq_empty_iff
alias ⟨_, Icc_eq_empty⟩ := Icc_eq_empty_iff
#align finset.Icc_eq_empty Finset.Icc_eq_empty
alias ⟨_, Ico_eq_empty⟩ := Ico_eq_empty_iff
#align finset.Ico_eq_empty Finset.Ico_eq_empty
alias ⟨_, Ioc_eq_empty⟩ := Ioc_eq_empty_iff
#align finset.Ioc_eq_empty Finset.Ioc_eq_empty
@[simp]
theorem Ioo_eq_empty (h : ¬a < b) : Ioo a b = ∅ :=
eq_empty_iff_forall_not_mem.2 fun _ hx => h ((mem_Ioo.1 hx).1.trans (mem_Ioo.1 hx).2)
#align finset.Ioo_eq_empty Finset.Ioo_eq_empty
@[simp]
theorem Icc_eq_empty_of_lt (h : b < a) : Icc a b = ∅ :=
Icc_eq_empty h.not_le
#align finset.Icc_eq_empty_of_lt Finset.Icc_eq_empty_of_lt
@[simp]
theorem Ico_eq_empty_of_le (h : b ≤ a) : Ico a b = ∅ :=
Ico_eq_empty h.not_lt
#align finset.Ico_eq_empty_of_le Finset.Ico_eq_empty_of_le
@[simp]
theorem Ioc_eq_empty_of_le (h : b ≤ a) : Ioc a b = ∅ :=
Ioc_eq_empty h.not_lt
#align finset.Ioc_eq_empty_of_le Finset.Ioc_eq_empty_of_le
@[simp]
theorem Ioo_eq_empty_of_le (h : b ≤ a) : Ioo a b = ∅ :=
Ioo_eq_empty h.not_lt
#align finset.Ioo_eq_empty_of_le Finset.Ioo_eq_empty_of_le
-- porting note (#10618): simp can prove this
-- @[simp]
theorem left_mem_Icc : a ∈ Icc a b ↔ a ≤ b := by simp only [mem_Icc, true_and_iff, le_rfl]
#align finset.left_mem_Icc Finset.left_mem_Icc
-- porting note (#10618): simp can prove this
-- @[simp]
theorem left_mem_Ico : a ∈ Ico a b ↔ a < b := by simp only [mem_Ico, true_and_iff, le_refl]
#align finset.left_mem_Ico Finset.left_mem_Ico
-- porting note (#10618): simp can prove this
-- @[simp]
theorem right_mem_Icc : b ∈ Icc a b ↔ a ≤ b := by simp only [mem_Icc, and_true_iff, le_rfl]
#align finset.right_mem_Icc Finset.right_mem_Icc
-- porting note (#10618): simp can prove this
-- @[simp]
theorem right_mem_Ioc : b ∈ Ioc a b ↔ a < b := by simp only [mem_Ioc, and_true_iff, le_rfl]
#align finset.right_mem_Ioc Finset.right_mem_Ioc
-- porting note (#10618): simp can prove this
-- @[simp]
theorem left_not_mem_Ioc : a ∉ Ioc a b := fun h => lt_irrefl _ (mem_Ioc.1 h).1
#align finset.left_not_mem_Ioc Finset.left_not_mem_Ioc
-- porting note (#10618): simp can prove this
-- @[simp]
theorem left_not_mem_Ioo : a ∉ Ioo a b := fun h => lt_irrefl _ (mem_Ioo.1 h).1
#align finset.left_not_mem_Ioo Finset.left_not_mem_Ioo
-- porting note (#10618): simp can prove this
-- @[simp]
theorem right_not_mem_Ico : b ∉ Ico a b := fun h => lt_irrefl _ (mem_Ico.1 h).2
#align finset.right_not_mem_Ico Finset.right_not_mem_Ico
-- porting note (#10618): simp can prove this
-- @[simp]
theorem right_not_mem_Ioo : b ∉ Ioo a b := fun h => lt_irrefl _ (mem_Ioo.1 h).2
#align finset.right_not_mem_Ioo Finset.right_not_mem_Ioo
theorem Icc_subset_Icc (ha : a₂ ≤ a₁) (hb : b₁ ≤ b₂) : Icc a₁ b₁ ⊆ Icc a₂ b₂ := by
simpa [← coe_subset] using Set.Icc_subset_Icc ha hb
#align finset.Icc_subset_Icc Finset.Icc_subset_Icc
theorem Ico_subset_Ico (ha : a₂ ≤ a₁) (hb : b₁ ≤ b₂) : Ico a₁ b₁ ⊆ Ico a₂ b₂ := by
simpa [← coe_subset] using Set.Ico_subset_Ico ha hb
#align finset.Ico_subset_Ico Finset.Ico_subset_Ico
theorem Ioc_subset_Ioc (ha : a₂ ≤ a₁) (hb : b₁ ≤ b₂) : Ioc a₁ b₁ ⊆ Ioc a₂ b₂ := by
simpa [← coe_subset] using Set.Ioc_subset_Ioc ha hb
#align finset.Ioc_subset_Ioc Finset.Ioc_subset_Ioc
theorem Ioo_subset_Ioo (ha : a₂ ≤ a₁) (hb : b₁ ≤ b₂) : Ioo a₁ b₁ ⊆ Ioo a₂ b₂ := by
simpa [← coe_subset] using Set.Ioo_subset_Ioo ha hb
#align finset.Ioo_subset_Ioo Finset.Ioo_subset_Ioo
theorem Icc_subset_Icc_left (h : a₁ ≤ a₂) : Icc a₂ b ⊆ Icc a₁ b :=
Icc_subset_Icc h le_rfl
#align finset.Icc_subset_Icc_left Finset.Icc_subset_Icc_left
theorem Ico_subset_Ico_left (h : a₁ ≤ a₂) : Ico a₂ b ⊆ Ico a₁ b :=
Ico_subset_Ico h le_rfl
#align finset.Ico_subset_Ico_left Finset.Ico_subset_Ico_left
theorem Ioc_subset_Ioc_left (h : a₁ ≤ a₂) : Ioc a₂ b ⊆ Ioc a₁ b :=
Ioc_subset_Ioc h le_rfl
#align finset.Ioc_subset_Ioc_left Finset.Ioc_subset_Ioc_left
theorem Ioo_subset_Ioo_left (h : a₁ ≤ a₂) : Ioo a₂ b ⊆ Ioo a₁ b :=
Ioo_subset_Ioo h le_rfl
#align finset.Ioo_subset_Ioo_left Finset.Ioo_subset_Ioo_left
theorem Icc_subset_Icc_right (h : b₁ ≤ b₂) : Icc a b₁ ⊆ Icc a b₂ :=
Icc_subset_Icc le_rfl h
#align finset.Icc_subset_Icc_right Finset.Icc_subset_Icc_right
theorem Ico_subset_Ico_right (h : b₁ ≤ b₂) : Ico a b₁ ⊆ Ico a b₂ :=
Ico_subset_Ico le_rfl h
#align finset.Ico_subset_Ico_right Finset.Ico_subset_Ico_right
theorem Ioc_subset_Ioc_right (h : b₁ ≤ b₂) : Ioc a b₁ ⊆ Ioc a b₂ :=
Ioc_subset_Ioc le_rfl h
#align finset.Ioc_subset_Ioc_right Finset.Ioc_subset_Ioc_right
theorem Ioo_subset_Ioo_right (h : b₁ ≤ b₂) : Ioo a b₁ ⊆ Ioo a b₂ :=
Ioo_subset_Ioo le_rfl h
#align finset.Ioo_subset_Ioo_right Finset.Ioo_subset_Ioo_right
theorem Ico_subset_Ioo_left (h : a₁ < a₂) : Ico a₂ b ⊆ Ioo a₁ b := by
rw [← coe_subset, coe_Ico, coe_Ioo]
exact Set.Ico_subset_Ioo_left h
#align finset.Ico_subset_Ioo_left Finset.Ico_subset_Ioo_left
theorem Ioc_subset_Ioo_right (h : b₁ < b₂) : Ioc a b₁ ⊆ Ioo a b₂ := by
rw [← coe_subset, coe_Ioc, coe_Ioo]
exact Set.Ioc_subset_Ioo_right h
#align finset.Ioc_subset_Ioo_right Finset.Ioc_subset_Ioo_right
theorem Icc_subset_Ico_right (h : b₁ < b₂) : Icc a b₁ ⊆ Ico a b₂ := by
rw [← coe_subset, coe_Icc, coe_Ico]
exact Set.Icc_subset_Ico_right h
#align finset.Icc_subset_Ico_right Finset.Icc_subset_Ico_right
theorem Ioo_subset_Ico_self : Ioo a b ⊆ Ico a b := by
rw [← coe_subset, coe_Ioo, coe_Ico]
exact Set.Ioo_subset_Ico_self
#align finset.Ioo_subset_Ico_self Finset.Ioo_subset_Ico_self
theorem Ioo_subset_Ioc_self : Ioo a b ⊆ Ioc a b := by
rw [← coe_subset, coe_Ioo, coe_Ioc]
exact Set.Ioo_subset_Ioc_self
#align finset.Ioo_subset_Ioc_self Finset.Ioo_subset_Ioc_self
theorem Ico_subset_Icc_self : Ico a b ⊆ Icc a b := by
rw [← coe_subset, coe_Ico, coe_Icc]
exact Set.Ico_subset_Icc_self
#align finset.Ico_subset_Icc_self Finset.Ico_subset_Icc_self
theorem Ioc_subset_Icc_self : Ioc a b ⊆ Icc a b := by
rw [← coe_subset, coe_Ioc, coe_Icc]
exact Set.Ioc_subset_Icc_self
#align finset.Ioc_subset_Icc_self Finset.Ioc_subset_Icc_self
theorem Ioo_subset_Icc_self : Ioo a b ⊆ Icc a b :=
Ioo_subset_Ico_self.trans Ico_subset_Icc_self
#align finset.Ioo_subset_Icc_self Finset.Ioo_subset_Icc_self
theorem Icc_subset_Icc_iff (h₁ : a₁ ≤ b₁) : Icc a₁ b₁ ⊆ Icc a₂ b₂ ↔ a₂ ≤ a₁ ∧ b₁ ≤ b₂ := by
rw [← coe_subset, coe_Icc, coe_Icc, Set.Icc_subset_Icc_iff h₁]
#align finset.Icc_subset_Icc_iff Finset.Icc_subset_Icc_iff
theorem Icc_subset_Ioo_iff (h₁ : a₁ ≤ b₁) : Icc a₁ b₁ ⊆ Ioo a₂ b₂ ↔ a₂ < a₁ ∧ b₁ < b₂ := by
rw [← coe_subset, coe_Icc, coe_Ioo, Set.Icc_subset_Ioo_iff h₁]
#align finset.Icc_subset_Ioo_iff Finset.Icc_subset_Ioo_iff
theorem Icc_subset_Ico_iff (h₁ : a₁ ≤ b₁) : Icc a₁ b₁ ⊆ Ico a₂ b₂ ↔ a₂ ≤ a₁ ∧ b₁ < b₂ := by
rw [← coe_subset, coe_Icc, coe_Ico, Set.Icc_subset_Ico_iff h₁]
#align finset.Icc_subset_Ico_iff Finset.Icc_subset_Ico_iff
theorem Icc_subset_Ioc_iff (h₁ : a₁ ≤ b₁) : Icc a₁ b₁ ⊆ Ioc a₂ b₂ ↔ a₂ < a₁ ∧ b₁ ≤ b₂ :=
(Icc_subset_Ico_iff h₁.dual).trans and_comm
#align finset.Icc_subset_Ioc_iff Finset.Icc_subset_Ioc_iff
--TODO: `Ico_subset_Ioo_iff`, `Ioc_subset_Ioo_iff`
| Mathlib/Order/Interval/Finset/Basic.lean | 276 | 279 | theorem Icc_ssubset_Icc_left (hI : a₂ ≤ b₂) (ha : a₂ < a₁) (hb : b₁ ≤ b₂) :
Icc a₁ b₁ ⊂ Icc a₂ b₂ := by |
rw [← coe_ssubset, coe_Icc, coe_Icc]
exact Set.Icc_ssubset_Icc_left hI ha hb
|
import Mathlib.Probability.Martingale.Convergence
import Mathlib.Probability.Martingale.OptionalStopping
import Mathlib.Probability.Martingale.Centering
#align_import probability.martingale.borel_cantelli from "leanprover-community/mathlib"@"2196ab363eb097c008d4497125e0dde23fb36db2"
open Filter
open scoped NNReal ENNReal MeasureTheory ProbabilityTheory BigOperators Topology
namespace MeasureTheory
variable {Ω : Type*} {m0 : MeasurableSpace Ω} {μ : Measure Ω} {ℱ : Filtration ℕ m0} {f : ℕ → Ω → ℝ}
{ω : Ω}
-- TODO: `leastGE` should be defined taking values in `WithTop ℕ` once the `stoppedProcess`
-- refactor is complete
noncomputable def leastGE (f : ℕ → Ω → ℝ) (r : ℝ) (n : ℕ) :=
hitting f (Set.Ici r) 0 n
#align measure_theory.least_ge MeasureTheory.leastGE
theorem Adapted.isStoppingTime_leastGE (r : ℝ) (n : ℕ) (hf : Adapted ℱ f) :
IsStoppingTime ℱ (leastGE f r n) :=
hitting_isStoppingTime hf measurableSet_Ici
#align measure_theory.adapted.is_stopping_time_least_ge MeasureTheory.Adapted.isStoppingTime_leastGE
theorem leastGE_le {i : ℕ} {r : ℝ} (ω : Ω) : leastGE f r i ω ≤ i :=
hitting_le ω
#align measure_theory.least_ge_le MeasureTheory.leastGE_le
-- The following four lemmas shows `leastGE` behaves like a stopped process. Ideally we should
-- define `leastGE` as a stopping time and take its stopped process. However, we can't do that
-- with our current definition since a stopping time takes only finite indicies. An upcomming
-- refactor should hopefully make it possible to have stopping times taking infinity as a value
theorem leastGE_mono {n m : ℕ} (hnm : n ≤ m) (r : ℝ) (ω : Ω) : leastGE f r n ω ≤ leastGE f r m ω :=
hitting_mono hnm
#align measure_theory.least_ge_mono MeasureTheory.leastGE_mono
theorem leastGE_eq_min (π : Ω → ℕ) (r : ℝ) (ω : Ω) {n : ℕ} (hπn : ∀ ω, π ω ≤ n) :
leastGE f r (π ω) ω = min (π ω) (leastGE f r n ω) := by
classical
refine le_antisymm (le_min (leastGE_le _) (leastGE_mono (hπn ω) r ω)) ?_
by_cases hle : π ω ≤ leastGE f r n ω
· rw [min_eq_left hle, leastGE]
by_cases h : ∃ j ∈ Set.Icc 0 (π ω), f j ω ∈ Set.Ici r
· refine hle.trans (Eq.le ?_)
rw [leastGE, ← hitting_eq_hitting_of_exists (hπn ω) h]
· simp only [hitting, if_neg h, le_rfl]
· rw [min_eq_right (not_le.1 hle).le, leastGE, leastGE, ←
hitting_eq_hitting_of_exists (hπn ω) _]
rw [not_le, leastGE, hitting_lt_iff _ (hπn ω)] at hle
exact
let ⟨j, hj₁, hj₂⟩ := hle
⟨j, ⟨hj₁.1, hj₁.2.le⟩, hj₂⟩
#align measure_theory.least_ge_eq_min MeasureTheory.leastGE_eq_min
theorem stoppedValue_stoppedValue_leastGE (f : ℕ → Ω → ℝ) (π : Ω → ℕ) (r : ℝ) {n : ℕ}
(hπn : ∀ ω, π ω ≤ n) : stoppedValue (fun i => stoppedValue f (leastGE f r i)) π =
stoppedValue (stoppedProcess f (leastGE f r n)) π := by
ext1 ω
simp (config := { unfoldPartialApp := true }) only [stoppedProcess, stoppedValue]
rw [leastGE_eq_min _ _ _ hπn]
#align measure_theory.stopped_value_stopped_value_least_ge MeasureTheory.stoppedValue_stoppedValue_leastGE
theorem Submartingale.stoppedValue_leastGE [IsFiniteMeasure μ] (hf : Submartingale f ℱ μ) (r : ℝ) :
Submartingale (fun i => stoppedValue f (leastGE f r i)) ℱ μ := by
rw [submartingale_iff_expected_stoppedValue_mono]
· intro σ π hσ hπ hσ_le_π hπ_bdd
obtain ⟨n, hπ_le_n⟩ := hπ_bdd
simp_rw [stoppedValue_stoppedValue_leastGE f σ r fun i => (hσ_le_π i).trans (hπ_le_n i)]
simp_rw [stoppedValue_stoppedValue_leastGE f π r hπ_le_n]
refine hf.expected_stoppedValue_mono ?_ ?_ ?_ fun ω => (min_le_left _ _).trans (hπ_le_n ω)
· exact hσ.min (hf.adapted.isStoppingTime_leastGE _ _)
· exact hπ.min (hf.adapted.isStoppingTime_leastGE _ _)
· exact fun ω => min_le_min (hσ_le_π ω) le_rfl
· exact fun i => stronglyMeasurable_stoppedValue_of_le hf.adapted.progMeasurable_of_discrete
(hf.adapted.isStoppingTime_leastGE _ _) leastGE_le
· exact fun i => integrable_stoppedValue _ (hf.adapted.isStoppingTime_leastGE _ _) hf.integrable
leastGE_le
#align measure_theory.submartingale.stopped_value_least_ge MeasureTheory.Submartingale.stoppedValue_leastGE
variable {r : ℝ} {R : ℝ≥0}
theorem norm_stoppedValue_leastGE_le (hr : 0 ≤ r) (hf0 : f 0 = 0)
(hbdd : ∀ᵐ ω ∂μ, ∀ i, |f (i + 1) ω - f i ω| ≤ R) (i : ℕ) :
∀ᵐ ω ∂μ, stoppedValue f (leastGE f r i) ω ≤ r + R := by
filter_upwards [hbdd] with ω hbddω
change f (leastGE f r i ω) ω ≤ r + R
by_cases heq : leastGE f r i ω = 0
· rw [heq, hf0, Pi.zero_apply]
exact add_nonneg hr R.coe_nonneg
· obtain ⟨k, hk⟩ := Nat.exists_eq_succ_of_ne_zero heq
rw [hk, add_comm, ← sub_le_iff_le_add]
have := not_mem_of_lt_hitting (hk.symm ▸ k.lt_succ_self : k < leastGE f r i ω) (zero_le _)
simp only [Set.mem_union, Set.mem_Iic, Set.mem_Ici, not_or, not_le] at this
exact (sub_lt_sub_left this _).le.trans ((le_abs_self _).trans (hbddω _))
#align measure_theory.norm_stopped_value_least_ge_le MeasureTheory.norm_stoppedValue_leastGE_le
theorem Submartingale.stoppedValue_leastGE_snorm_le [IsFiniteMeasure μ] (hf : Submartingale f ℱ μ)
(hr : 0 ≤ r) (hf0 : f 0 = 0) (hbdd : ∀ᵐ ω ∂μ, ∀ i, |f (i + 1) ω - f i ω| ≤ R) (i : ℕ) :
snorm (stoppedValue f (leastGE f r i)) 1 μ ≤ 2 * μ Set.univ * ENNReal.ofReal (r + R) := by
refine snorm_one_le_of_le' ((hf.stoppedValue_leastGE r).integrable _) ?_
(norm_stoppedValue_leastGE_le hr hf0 hbdd i)
rw [← integral_univ]
refine le_trans ?_ ((hf.stoppedValue_leastGE r).setIntegral_le (zero_le _) MeasurableSet.univ)
simp_rw [stoppedValue, leastGE, hitting_of_le le_rfl, hf0, integral_zero', le_rfl]
#align measure_theory.submartingale.stopped_value_least_ge_snorm_le MeasureTheory.Submartingale.stoppedValue_leastGE_snorm_le
theorem Submartingale.stoppedValue_leastGE_snorm_le' [IsFiniteMeasure μ] (hf : Submartingale f ℱ μ)
(hr : 0 ≤ r) (hf0 : f 0 = 0) (hbdd : ∀ᵐ ω ∂μ, ∀ i, |f (i + 1) ω - f i ω| ≤ R) (i : ℕ) :
snorm (stoppedValue f (leastGE f r i)) 1 μ ≤
ENNReal.toNNReal (2 * μ Set.univ * ENNReal.ofReal (r + R)) := by
refine (hf.stoppedValue_leastGE_snorm_le hr hf0 hbdd i).trans ?_
simp [ENNReal.coe_toNNReal (measure_ne_top μ _), ENNReal.coe_toNNReal]
#align measure_theory.submartingale.stopped_value_least_ge_snorm_le' MeasureTheory.Submartingale.stoppedValue_leastGE_snorm_le'
| Mathlib/Probability/Martingale/BorelCantelli.lean | 154 | 175 | theorem Submartingale.exists_tendsto_of_abs_bddAbove_aux [IsFiniteMeasure μ]
(hf : Submartingale f ℱ μ) (hf0 : f 0 = 0) (hbdd : ∀ᵐ ω ∂μ, ∀ i, |f (i + 1) ω - f i ω| ≤ R) :
∀ᵐ ω ∂μ, BddAbove (Set.range fun n => f n ω) → ∃ c, Tendsto (fun n => f n ω) atTop (𝓝 c) := by |
have ht :
∀ᵐ ω ∂μ, ∀ i : ℕ, ∃ c, Tendsto (fun n => stoppedValue f (leastGE f i n) ω) atTop (𝓝 c) := by
rw [ae_all_iff]
exact fun i => Submartingale.exists_ae_tendsto_of_bdd (hf.stoppedValue_leastGE i)
(hf.stoppedValue_leastGE_snorm_le' i.cast_nonneg hf0 hbdd)
filter_upwards [ht] with ω hω hωb
rw [BddAbove] at hωb
obtain ⟨i, hi⟩ := exists_nat_gt hωb.some
have hib : ∀ n, f n ω < i := by
intro n
exact lt_of_le_of_lt ((mem_upperBounds.1 hωb.some_mem) _ ⟨n, rfl⟩) hi
have heq : ∀ n, stoppedValue f (leastGE f i n) ω = f n ω := by
intro n
rw [leastGE]; unfold hitting; rw [stoppedValue]
rw [if_neg]
simp only [Set.mem_Icc, Set.mem_union, Set.mem_Ici]
push_neg
exact fun j _ => hib j
simp only [← heq, hω i]
|
import Mathlib.Algebra.Group.Prod
import Mathlib.Order.Cover
#align_import algebra.support from "leanprover-community/mathlib"@"29cb56a7b35f72758b05a30490e1f10bd62c35c1"
assert_not_exists MonoidWithZero
open Set
namespace Function
variable {α β A B M N P G : Type*}
section One
variable [One M] [One N] [One P]
@[to_additive "`support` of a function is the set of points `x` such that `f x ≠ 0`."]
def mulSupport (f : α → M) : Set α := {x | f x ≠ 1}
#align function.mul_support Function.mulSupport
#align function.support Function.support
@[to_additive]
theorem mulSupport_eq_preimage (f : α → M) : mulSupport f = f ⁻¹' {1}ᶜ :=
rfl
#align function.mul_support_eq_preimage Function.mulSupport_eq_preimage
#align function.support_eq_preimage Function.support_eq_preimage
@[to_additive]
theorem nmem_mulSupport {f : α → M} {x : α} : x ∉ mulSupport f ↔ f x = 1 :=
not_not
#align function.nmem_mul_support Function.nmem_mulSupport
#align function.nmem_support Function.nmem_support
@[to_additive]
theorem compl_mulSupport {f : α → M} : (mulSupport f)ᶜ = { x | f x = 1 } :=
ext fun _ => nmem_mulSupport
#align function.compl_mul_support Function.compl_mulSupport
#align function.compl_support Function.compl_support
@[to_additive (attr := simp)]
theorem mem_mulSupport {f : α → M} {x : α} : x ∈ mulSupport f ↔ f x ≠ 1 :=
Iff.rfl
#align function.mem_mul_support Function.mem_mulSupport
#align function.mem_support Function.mem_support
@[to_additive (attr := simp)]
theorem mulSupport_subset_iff {f : α → M} {s : Set α} : mulSupport f ⊆ s ↔ ∀ x, f x ≠ 1 → x ∈ s :=
Iff.rfl
#align function.mul_support_subset_iff Function.mulSupport_subset_iff
#align function.support_subset_iff Function.support_subset_iff
@[to_additive]
theorem mulSupport_subset_iff' {f : α → M} {s : Set α} :
mulSupport f ⊆ s ↔ ∀ x ∉ s, f x = 1 :=
forall_congr' fun _ => not_imp_comm
#align function.mul_support_subset_iff' Function.mulSupport_subset_iff'
#align function.support_subset_iff' Function.support_subset_iff'
@[to_additive]
theorem mulSupport_eq_iff {f : α → M} {s : Set α} :
mulSupport f = s ↔ (∀ x, x ∈ s → f x ≠ 1) ∧ ∀ x, x ∉ s → f x = 1 := by
simp (config := { contextual := true }) only [ext_iff, mem_mulSupport, ne_eq, iff_def,
not_imp_comm, and_comm, forall_and]
#align function.mul_support_eq_iff Function.mulSupport_eq_iff
#align function.support_eq_iff Function.support_eq_iff
@[to_additive]
theorem ext_iff_mulSupport {f g : α → M} :
f = g ↔ f.mulSupport = g.mulSupport ∧ ∀ x ∈ f.mulSupport, f x = g x :=
⟨fun h ↦ h ▸ ⟨rfl, fun _ _ ↦ rfl⟩, fun ⟨h₁, h₂⟩ ↦ funext fun x ↦ by
if hx : x ∈ f.mulSupport then exact h₂ x hx
else rw [nmem_mulSupport.1 hx, nmem_mulSupport.1 (mt (Set.ext_iff.1 h₁ x).2 hx)]⟩
@[to_additive]
| Mathlib/Algebra/Group/Support.lean | 88 | 90 | theorem mulSupport_update_of_ne_one [DecidableEq α] (f : α → M) (x : α) {y : M} (hy : y ≠ 1) :
mulSupport (update f x y) = insert x (mulSupport f) := by |
ext a; rcases eq_or_ne a x with rfl | hne <;> simp [*]
|
import Mathlib.AlgebraicGeometry.Pullbacks
import Mathlib.AlgebraicGeometry.AffineScheme
#align_import algebraic_geometry.limits from "leanprover-community/mathlib"@"70fd9563a21e7b963887c9360bd29b2393e6225a"
suppress_compilation
set_option linter.uppercaseLean3 false
universe u
open CategoryTheory CategoryTheory.Limits Opposite TopologicalSpace
namespace AlgebraicGeometry
noncomputable def specZIsTerminal : IsTerminal (Scheme.Spec.obj (op <| CommRingCat.of ℤ)) :=
@IsTerminal.isTerminalObj _ _ _ _ Scheme.Spec _ inferInstance
(terminalOpOfInitial CommRingCat.zIsInitial)
#align algebraic_geometry.Spec_Z_is_terminal AlgebraicGeometry.specZIsTerminal
instance : HasTerminal Scheme :=
hasTerminal_of_hasTerminal_of_preservesLimit Scheme.Spec
instance : IsAffine (⊤_ Scheme.{u}) :=
isAffineOfIso (PreservesTerminal.iso Scheme.Spec).inv
instance : HasFiniteLimits Scheme :=
hasFiniteLimits_of_hasTerminal_and_pullbacks
section Initial
@[simps]
def Scheme.emptyTo (X : Scheme.{u}) : ∅ ⟶ X :=
⟨{ base := ⟨fun x => PEmpty.elim x, by continuity⟩
c := { app := fun U => CommRingCat.punitIsTerminal.from _ } }, fun x => PEmpty.elim x⟩
#align algebraic_geometry.Scheme.empty_to AlgebraicGeometry.Scheme.emptyTo
@[ext]
theorem Scheme.empty_ext {X : Scheme.{u}} (f g : ∅ ⟶ X) : f = g :=
-- Porting note: `ext` regression
-- see https://github.com/leanprover-community/mathlib4/issues/5229
LocallyRingedSpace.Hom.ext _ _ <| PresheafedSpace.ext _ _ (by ext a; exact PEmpty.elim a) <|
NatTrans.ext _ _ <| funext fun a => by aesop_cat
#align algebraic_geometry.Scheme.empty_ext AlgebraicGeometry.Scheme.empty_ext
theorem Scheme.eq_emptyTo {X : Scheme.{u}} (f : ∅ ⟶ X) : f = Scheme.emptyTo X :=
Scheme.empty_ext f (Scheme.emptyTo X)
#align algebraic_geometry.Scheme.eq_empty_to AlgebraicGeometry.Scheme.eq_emptyTo
instance Scheme.hom_unique_of_empty_source (X : Scheme.{u}) : Unique (∅ ⟶ X) :=
⟨⟨Scheme.emptyTo _⟩, fun _ => Scheme.empty_ext _ _⟩
def emptyIsInitial : IsInitial (∅ : Scheme.{u}) :=
IsInitial.ofUnique _
#align algebraic_geometry.empty_is_initial AlgebraicGeometry.emptyIsInitial
@[simp]
theorem emptyIsInitial_to : emptyIsInitial.to = Scheme.emptyTo :=
rfl
#align algebraic_geometry.empty_is_initial_to AlgebraicGeometry.emptyIsInitial_to
instance : IsEmpty Scheme.empty.carrier :=
show IsEmpty PEmpty by infer_instance
instance spec_punit_isEmpty : IsEmpty (Scheme.Spec.obj (op <| CommRingCat.of PUnit)).carrier :=
inferInstanceAs <| IsEmpty (PrimeSpectrum PUnit)
#align algebraic_geometry.Spec_punit_is_empty AlgebraicGeometry.spec_punit_isEmpty
instance (priority := 100) isOpenImmersion_of_isEmpty {X Y : Scheme} (f : X ⟶ Y)
[IsEmpty X.carrier] : IsOpenImmersion f := by
apply (config := { allowSynthFailures := true }) IsOpenImmersion.of_stalk_iso
· exact .of_isEmpty (X := X.carrier) _
· intro (i : X.carrier); exact isEmptyElim i
#align algebraic_geometry.is_open_immersion_of_is_empty AlgebraicGeometry.isOpenImmersion_of_isEmpty
instance (priority := 100) isIso_of_isEmpty {X Y : Scheme} (f : X ⟶ Y) [IsEmpty Y.carrier] :
IsIso f := by
haveI : IsEmpty X.carrier := f.1.base.1.isEmpty
have : Epi f.1.base := by
rw [TopCat.epi_iff_surjective]; rintro (x : Y.carrier)
exact isEmptyElim x
apply IsOpenImmersion.to_iso
#align algebraic_geometry.is_iso_of_is_empty AlgebraicGeometry.isIso_of_isEmpty
noncomputable def isInitialOfIsEmpty {X : Scheme} [IsEmpty X.carrier] : IsInitial X :=
emptyIsInitial.ofIso (asIso <| emptyIsInitial.to _)
#align algebraic_geometry.is_initial_of_is_empty AlgebraicGeometry.isInitialOfIsEmpty
noncomputable def specPunitIsInitial : IsInitial (Scheme.Spec.obj (op <| CommRingCat.of PUnit)) :=
emptyIsInitial.ofIso (asIso <| emptyIsInitial.to _)
#align algebraic_geometry.Spec_punit_is_initial AlgebraicGeometry.specPunitIsInitial
instance (priority := 100) isAffine_of_isEmpty {X : Scheme} [IsEmpty X.carrier] : IsAffine X :=
isAffineOfIso
(inv (emptyIsInitial.to X) ≫ emptyIsInitial.to (Scheme.Spec.obj (op <| CommRingCat.of PUnit)))
#align algebraic_geometry.is_affine_of_is_empty AlgebraicGeometry.isAffine_of_isEmpty
instance : HasInitial Scheme :=
-- Porting note: this instance was not needed
haveI : (Y : Scheme) → Unique (Scheme.empty ⟶ Y) := Scheme.hom_unique_of_empty_source
hasInitial_of_unique Scheme.empty
instance initial_isEmpty : IsEmpty (⊥_ Scheme).carrier :=
⟨fun x => ((initial.to Scheme.empty : _).1.base x).elim⟩
#align algebraic_geometry.initial_is_empty AlgebraicGeometry.initial_isEmpty
| Mathlib/AlgebraicGeometry/Limits.lean | 133 | 139 | theorem bot_isAffineOpen (X : Scheme) : IsAffineOpen (⊥ : Opens X.carrier) := by |
convert rangeIsAffineOpenOfOpenImmersion (initial.to X)
ext
-- Porting note: added this `erw` to turn LHS to `False`
erw [Set.mem_empty_iff_false]
rw [false_iff_iff]
exact fun x => isEmptyElim (show (⊥_ Scheme).carrier from x.choose)
|
import Mathlib.Algebra.Order.Group.Basic
import Mathlib.Algebra.Order.Ring.Basic
import Mathlib.Combinatorics.Enumerative.DoubleCounting
import Mathlib.Data.Finset.Pointwise
import Mathlib.Tactic.GCongr
#align_import combinatorics.additive.pluennecke_ruzsa from "leanprover-community/mathlib"@"4aab2abced69a9e579b1e6dc2856ed3db48e2cbd"
open Nat
open NNRat Pointwise
namespace Finset
variable {α : Type*} [CommGroup α] [DecidableEq α] {A B C : Finset α}
@[to_additive card_sub_mul_le_card_sub_mul_card_sub
"**Ruzsa's triangle inequality**. Subtraction version."]
theorem card_div_mul_le_card_div_mul_card_div (A B C : Finset α) :
(A / C).card * B.card ≤ (A / B).card * (B / C).card := by
rw [← card_product (A / B), ← mul_one ((A / B) ×ˢ (B / C)).card]
refine card_mul_le_card_mul (fun b ac ↦ ac.1 * ac.2 = b) (fun x hx ↦ ?_)
fun x _ ↦ card_le_one_iff.2 fun hu hv ↦
((mem_bipartiteBelow _).1 hu).2.symm.trans ?_
obtain ⟨a, ha, c, hc, rfl⟩ := mem_div.1 hx
refine card_le_card_of_inj_on (fun b ↦ (a / b, b / c)) (fun b hb ↦ ?_) fun b₁ _ b₂ _ h ↦ ?_
· rw [mem_bipartiteAbove]
exact ⟨mk_mem_product (div_mem_div ha hb) (div_mem_div hb hc), div_mul_div_cancel' _ _ _⟩
· exact div_right_injective (Prod.ext_iff.1 h).1
· exact ((mem_bipartiteBelow _).1 hv).2
#align finset.card_div_mul_le_card_div_mul_card_div Finset.card_div_mul_le_card_div_mul_card_div
#align finset.card_sub_mul_le_card_sub_mul_card_sub Finset.card_sub_mul_le_card_sub_mul_card_sub
@[to_additive card_sub_mul_le_card_add_mul_card_add
"**Ruzsa's triangle inequality**. Sub-add-add version."]
theorem card_div_mul_le_card_mul_mul_card_mul (A B C : Finset α) :
(A / C).card * B.card ≤ (A * B).card * (B * C).card := by
rw [← div_inv_eq_mul, ← card_inv B, ← card_inv (B * C), mul_inv, ← div_eq_mul_inv]
exact card_div_mul_le_card_div_mul_card_div _ _ _
#align finset.card_div_mul_le_card_mul_mul_card_mul Finset.card_div_mul_le_card_mul_mul_card_mul
#align finset.card_sub_mul_le_card_add_mul_card_add Finset.card_sub_mul_le_card_add_mul_card_add
@[to_additive card_add_mul_le_card_sub_mul_card_add
"**Ruzsa's triangle inequality**. Add-sub-sub version."]
theorem card_mul_mul_le_card_div_mul_card_mul (A B C : Finset α) :
(A * C).card * B.card ≤ (A / B).card * (B * C).card := by
rw [← div_inv_eq_mul, ← div_inv_eq_mul B]
exact card_div_mul_le_card_div_mul_card_div _ _ _
#align finset.card_mul_mul_le_card_div_mul_card_mul Finset.card_mul_mul_le_card_div_mul_card_mul
#align finset.card_add_mul_le_card_sub_mul_card_add Finset.card_add_mul_le_card_sub_mul_card_add
@[to_additive card_add_mul_le_card_add_mul_card_sub
"**Ruzsa's triangle inequality**. Add-add-sub version."]
theorem card_mul_mul_le_card_mul_mul_card_div (A B C : Finset α) :
(A * C).card * B.card ≤ (A * B).card * (B / C).card := by
rw [← div_inv_eq_mul, div_eq_mul_inv B]
exact card_div_mul_le_card_mul_mul_card_mul _ _ _
#align finset.card_mul_mul_le_card_mul_mul_card_div Finset.card_mul_mul_le_card_mul_mul_card_div
#align finset.card_add_mul_le_card_add_mul_card_sub Finset.card_add_mul_le_card_add_mul_card_sub
set_option backward.isDefEq.lazyWhnfCore false in -- See https://github.com/leanprover-community/mathlib4/issues/12534
@[to_additive]
theorem mul_pluennecke_petridis (C : Finset α)
(hA : ∀ A' ⊆ A, (A * B).card * A'.card ≤ (A' * B).card * A.card) :
(A * B * C).card * A.card ≤ (A * B).card * (A * C).card := by
induction' C using Finset.induction_on with x C _ ih
· simp
set A' := A ∩ (A * C / {x}) with hA'
set C' := insert x C with hC'
have h₀ : A' * {x} = A * {x} ∩ (A * C) := by
rw [hA', inter_mul_singleton, (isUnit_singleton x).div_mul_cancel]
have h₁ : A * B * C' = A * B * C ∪ (A * B * {x}) \ (A' * B * {x}) := by
rw [hC', insert_eq, union_comm, mul_union]
refine (sup_sdiff_eq_sup ?_).symm
rw [mul_right_comm, mul_right_comm A, h₀]
exact mul_subset_mul_right inter_subset_right
have h₂ : A' * B * {x} ⊆ A * B * {x} :=
mul_subset_mul_right (mul_subset_mul_right inter_subset_left)
have h₃ : (A * B * C').card ≤ (A * B * C).card + (A * B).card - (A' * B).card := by
rw [h₁]
refine (card_union_le _ _).trans_eq ?_
rw [card_sdiff h₂, ← add_tsub_assoc_of_le (card_le_card h₂), card_mul_singleton,
card_mul_singleton]
refine (mul_le_mul_right' h₃ _).trans ?_
rw [tsub_mul, add_mul]
refine (tsub_le_tsub (add_le_add_right ih _) <| hA _ inter_subset_left).trans_eq ?_
rw [← mul_add, ← mul_tsub, ← hA', hC', insert_eq, mul_union, ← card_mul_singleton A x, ←
card_mul_singleton A' x, add_comm (card _), h₀,
eq_tsub_of_add_eq (card_union_add_card_inter _ _)]
#align finset.mul_pluennecke_petridis Finset.mul_pluennecke_petridis
#align finset.add_pluennecke_petridis Finset.add_pluennecke_petridis
-- Auxiliary lemma for Ruzsa's triangle sum inequality, and the Plünnecke-Ruzsa inequality.
@[to_additive]
private theorem mul_aux (hA : A.Nonempty) (hAB : A ⊆ B)
(h : ∀ A' ∈ B.powerset.erase ∅, ((A * C).card : ℚ≥0) / ↑A.card ≤ (A' * C).card / ↑A'.card) :
∀ A' ⊆ A, (A * C).card * A'.card ≤ (A' * C).card * A.card := by
rintro A' hAA'
obtain rfl | hA' := A'.eq_empty_or_nonempty
· simp
have hA₀ : (0 : ℚ≥0) < A.card := cast_pos.2 hA.card_pos
have hA₀' : (0 : ℚ≥0) < A'.card := cast_pos.2 hA'.card_pos
exact mod_cast
(div_le_div_iff hA₀ hA₀').1
(h _ <| mem_erase_of_ne_of_mem hA'.ne_empty <| mem_powerset.2 <| hAA'.trans hAB)
@[to_additive card_add_mul_card_le_card_add_mul_card_add
"**Ruzsa's triangle inequality**. Addition version."]
theorem card_mul_mul_card_le_card_mul_mul_card_mul (A B C : Finset α) :
(A * C).card * B.card ≤ (A * B).card * (B * C).card := by
obtain rfl | hB := B.eq_empty_or_nonempty
· simp
have hB' : B ∈ B.powerset.erase ∅ := mem_erase_of_ne_of_mem hB.ne_empty (mem_powerset_self _)
obtain ⟨U, hU, hUA⟩ :=
exists_min_image (B.powerset.erase ∅) (fun U ↦ (U * A).card / U.card : _ → ℚ≥0) ⟨B, hB'⟩
rw [mem_erase, mem_powerset, ← nonempty_iff_ne_empty] at hU
refine cast_le.1 (?_ : (_ : ℚ≥0) ≤ _)
push_cast
refine (le_div_iff <| cast_pos.2 hB.card_pos).1 ?_
rw [mul_div_right_comm, mul_comm _ B]
refine (Nat.cast_le.2 <| card_le_card_mul_left _ hU.1).trans ?_
refine le_trans ?_
(mul_le_mul (hUA _ hB') (cast_le.2 <| card_le_card <| mul_subset_mul_right hU.2)
(zero_le _) (zero_le _))
rw [← mul_div_right_comm, ← mul_assoc]
refine (le_div_iff <| cast_pos.2 hU.1.card_pos).2 ?_
exact mod_cast mul_pluennecke_petridis C (mul_aux hU.1 hU.2 hUA)
#align finset.card_mul_mul_card_le_card_mul_mul_card_mul Finset.card_mul_mul_card_le_card_mul_mul_card_mul
#align finset.card_add_mul_card_le_card_add_mul_card_add Finset.card_add_mul_card_le_card_add_mul_card_add
@[to_additive card_add_mul_le_card_sub_mul_card_sub
"**Ruzsa's triangle inequality**. Add-sub-sub version."]
theorem card_mul_mul_le_card_div_mul_card_div (A B C : Finset α) :
(A * C).card * B.card ≤ (A / B).card * (B / C).card := by
rw [div_eq_mul_inv, ← card_inv B, ← card_inv (B / C), inv_div', div_inv_eq_mul]
exact card_mul_mul_card_le_card_mul_mul_card_mul _ _ _
#align finset.card_mul_mul_le_card_div_mul_card_div Finset.card_mul_mul_le_card_div_mul_card_div
@[to_additive card_sub_mul_le_card_add_mul_card_sub
"**Ruzsa's triangle inequality**. Sub-add-sub version."]
theorem card_div_mul_le_card_mul_mul_card_div (A B C : Finset α) :
(A / C).card * B.card ≤ (A * B).card * (B / C).card := by
rw [div_eq_mul_inv, div_eq_mul_inv]
exact card_mul_mul_card_le_card_mul_mul_card_mul _ _ _
#align finset.card_div_mul_le_card_mul_mul_card_div Finset.card_div_mul_le_card_mul_mul_card_div
@[to_additive card_sub_mul_le_card_sub_mul_card_add
"**Ruzsa's triangle inequality**. Sub-sub-add version."]
| Mathlib/Combinatorics/Additive/PluenneckeRuzsa.lean | 185 | 188 | theorem card_div_mul_le_card_div_mul_card_mul (A B C : Finset α) :
(A / C).card * B.card ≤ (A / B).card * (B * C).card := by |
rw [← div_inv_eq_mul, div_eq_mul_inv]
exact card_mul_mul_le_card_div_mul_card_div _ _ _
|
import Mathlib.LinearAlgebra.AffineSpace.AffineEquiv
#align_import linear_algebra.affine_space.midpoint from "leanprover-community/mathlib"@"2196ab363eb097c008d4497125e0dde23fb36db2"
open AffineMap AffineEquiv
section
variable (R : Type*) {V V' P P' : Type*} [Ring R] [Invertible (2 : R)] [AddCommGroup V]
[Module R V] [AddTorsor V P] [AddCommGroup V'] [Module R V'] [AddTorsor V' P']
def midpoint (x y : P) : P :=
lineMap x y (⅟ 2 : R)
#align midpoint midpoint
variable {R} {x y z : P}
@[simp]
theorem AffineMap.map_midpoint (f : P →ᵃ[R] P') (a b : P) :
f (midpoint R a b) = midpoint R (f a) (f b) :=
f.apply_lineMap a b _
#align affine_map.map_midpoint AffineMap.map_midpoint
@[simp]
theorem AffineEquiv.map_midpoint (f : P ≃ᵃ[R] P') (a b : P) :
f (midpoint R a b) = midpoint R (f a) (f b) :=
f.apply_lineMap a b _
#align affine_equiv.map_midpoint AffineEquiv.map_midpoint
theorem AffineEquiv.pointReflection_midpoint_left (x y : P) :
pointReflection R (midpoint R x y) x = y := by
rw [midpoint, pointReflection_apply, lineMap_apply, vadd_vsub, vadd_vadd, ← add_smul, ← two_mul,
mul_invOf_self, one_smul, vsub_vadd]
#align affine_equiv.point_reflection_midpoint_left AffineEquiv.pointReflection_midpoint_left
@[simp] -- Porting note: added variant with `Equiv.pointReflection` for `simp`
theorem Equiv.pointReflection_midpoint_left (x y : P) :
(Equiv.pointReflection (midpoint R x y)) x = y := by
rw [midpoint, pointReflection_apply, lineMap_apply, vadd_vsub, vadd_vadd, ← add_smul, ← two_mul,
mul_invOf_self, one_smul, vsub_vadd]
theorem midpoint_comm (x y : P) : midpoint R x y = midpoint R y x := by
rw [midpoint, ← lineMap_apply_one_sub, one_sub_invOf_two, midpoint]
#align midpoint_comm midpoint_comm
theorem AffineEquiv.pointReflection_midpoint_right (x y : P) :
pointReflection R (midpoint R x y) y = x := by
rw [midpoint_comm, AffineEquiv.pointReflection_midpoint_left]
#align affine_equiv.point_reflection_midpoint_right AffineEquiv.pointReflection_midpoint_right
@[simp] -- Porting note: added variant with `Equiv.pointReflection` for `simp`
theorem Equiv.pointReflection_midpoint_right (x y : P) :
(Equiv.pointReflection (midpoint R x y)) y = x := by
rw [midpoint_comm, Equiv.pointReflection_midpoint_left]
theorem midpoint_vsub_midpoint (p₁ p₂ p₃ p₄ : P) :
midpoint R p₁ p₂ -ᵥ midpoint R p₃ p₄ = midpoint R (p₁ -ᵥ p₃) (p₂ -ᵥ p₄) :=
lineMap_vsub_lineMap _ _ _ _ _
#align midpoint_vsub_midpoint midpoint_vsub_midpoint
theorem midpoint_vadd_midpoint (v v' : V) (p p' : P) :
midpoint R v v' +ᵥ midpoint R p p' = midpoint R (v +ᵥ p) (v' +ᵥ p') :=
lineMap_vadd_lineMap _ _ _ _ _
#align midpoint_vadd_midpoint midpoint_vadd_midpoint
theorem midpoint_eq_iff {x y z : P} : midpoint R x y = z ↔ pointReflection R z x = y :=
eq_comm.trans
((injective_pointReflection_left_of_module R x).eq_iff'
(AffineEquiv.pointReflection_midpoint_left x y)).symm
#align midpoint_eq_iff midpoint_eq_iff
@[simp]
theorem midpoint_pointReflection_left (x y : P) :
midpoint R (Equiv.pointReflection x y) y = x :=
midpoint_eq_iff.2 <| Equiv.pointReflection_involutive _ _
@[simp]
theorem midpoint_pointReflection_right (x y : P) :
midpoint R y (Equiv.pointReflection x y) = x :=
midpoint_eq_iff.2 rfl
@[simp]
theorem midpoint_vsub_left (p₁ p₂ : P) : midpoint R p₁ p₂ -ᵥ p₁ = (⅟ 2 : R) • (p₂ -ᵥ p₁) :=
lineMap_vsub_left _ _ _
#align midpoint_vsub_left midpoint_vsub_left
@[simp]
| Mathlib/LinearAlgebra/AffineSpace/Midpoint.lean | 119 | 120 | theorem midpoint_vsub_right (p₁ p₂ : P) : midpoint R p₁ p₂ -ᵥ p₂ = (⅟ 2 : R) • (p₁ -ᵥ p₂) := by |
rw [midpoint_comm, midpoint_vsub_left]
|
import Mathlib.CategoryTheory.Sites.Sheaf
#align_import category_theory.sites.plus from "leanprover-community/mathlib"@"70fd9563a21e7b963887c9360bd29b2393e6225a"
namespace CategoryTheory.GrothendieckTopology
open CategoryTheory
open CategoryTheory.Limits
open Opposite
universe w v u
variable {C : Type u} [Category.{v} C] (J : GrothendieckTopology C)
variable {D : Type w} [Category.{max v u} D]
noncomputable section
variable [∀ (P : Cᵒᵖ ⥤ D) (X : C) (S : J.Cover X), HasMultiequalizer (S.index P)]
variable (P : Cᵒᵖ ⥤ D)
@[simps]
def diagram (X : C) : (J.Cover X)ᵒᵖ ⥤ D where
obj S := multiequalizer (S.unop.index P)
map {S _} f :=
Multiequalizer.lift _ _ (fun I => Multiequalizer.ι (S.unop.index P) (I.map f.unop)) fun I =>
Multiequalizer.condition (S.unop.index P) (I.map f.unop)
#align category_theory.grothendieck_topology.diagram CategoryTheory.GrothendieckTopology.diagram
@[simps]
def diagramPullback {X Y : C} (f : X ⟶ Y) : J.diagram P Y ⟶ (J.pullback f).op ⋙ J.diagram P X where
app S :=
Multiequalizer.lift _ _ (fun I => Multiequalizer.ι (S.unop.index P) I.base) fun I =>
Multiequalizer.condition (S.unop.index P) I.base
naturality S T f := Multiequalizer.hom_ext _ _ _ (fun I => by dsimp; simp; rfl)
#align category_theory.grothendieck_topology.diagram_pullback CategoryTheory.GrothendieckTopology.diagramPullback
@[simps]
def diagramNatTrans {P Q : Cᵒᵖ ⥤ D} (η : P ⟶ Q) (X : C) : J.diagram P X ⟶ J.diagram Q X where
app W :=
Multiequalizer.lift _ _ (fun i => Multiequalizer.ι _ _ ≫ η.app _) (fun i => by
dsimp only
erw [Category.assoc, Category.assoc, ← η.naturality, ← η.naturality,
Multiequalizer.condition_assoc]
rfl)
#align category_theory.grothendieck_topology.diagram_nat_trans CategoryTheory.GrothendieckTopology.diagramNatTrans
@[simp]
theorem diagramNatTrans_id (X : C) (P : Cᵒᵖ ⥤ D) :
J.diagramNatTrans (𝟙 P) X = 𝟙 (J.diagram P X) := by
ext : 2
refine Multiequalizer.hom_ext _ _ _ (fun i => ?_)
dsimp
simp only [limit.lift_π, Multifork.ofι_pt, Multifork.ofι_π_app, Category.id_comp]
erw [Category.comp_id]
#align category_theory.grothendieck_topology.diagram_nat_trans_id CategoryTheory.GrothendieckTopology.diagramNatTrans_id
@[simp]
| Mathlib/CategoryTheory/Sites/Plus.lean | 81 | 86 | theorem diagramNatTrans_zero [Preadditive D] (X : C) (P Q : Cᵒᵖ ⥤ D) :
J.diagramNatTrans (0 : P ⟶ Q) X = 0 := by |
ext : 2
refine Multiequalizer.hom_ext _ _ _ (fun i => ?_)
dsimp
rw [zero_comp, Multiequalizer.lift_ι, comp_zero]
|
import Mathlib.Data.Matrix.Basis
import Mathlib.RingTheory.TensorProduct.Basic
#align_import ring_theory.matrix_algebra from "leanprover-community/mathlib"@"6c351a8fb9b06e5a542fdf427bfb9f46724f9453"
suppress_compilation
universe u v w
open TensorProduct
open TensorProduct
open Algebra.TensorProduct
open Matrix
variable {R : Type u} [CommSemiring R]
variable {A : Type v} [Semiring A] [Algebra R A]
variable {n : Type w}
variable (R A n)
namespace MatrixEquivTensor
def toFunBilinear : A →ₗ[R] Matrix n n R →ₗ[R] Matrix n n A :=
(Algebra.lsmul R R (Matrix n n A)).toLinearMap.compl₂ (Algebra.linearMap R A).mapMatrix
#align matrix_equiv_tensor.to_fun_bilinear MatrixEquivTensor.toFunBilinear
@[simp]
theorem toFunBilinear_apply (a : A) (m : Matrix n n R) :
toFunBilinear R A n a m = a • m.map (algebraMap R A) :=
rfl
#align matrix_equiv_tensor.to_fun_bilinear_apply MatrixEquivTensor.toFunBilinear_apply
def toFunLinear : A ⊗[R] Matrix n n R →ₗ[R] Matrix n n A :=
TensorProduct.lift (toFunBilinear R A n)
#align matrix_equiv_tensor.to_fun_linear MatrixEquivTensor.toFunLinear
variable [DecidableEq n] [Fintype n]
def toFunAlgHom : A ⊗[R] Matrix n n R →ₐ[R] Matrix n n A :=
algHomOfLinearMapTensorProduct (toFunLinear R A n)
(by
intros
simp_rw [toFunLinear, lift.tmul, toFunBilinear_apply, Matrix.map_mul]
ext
dsimp
simp_rw [Matrix.mul_apply, Matrix.smul_apply, Matrix.map_apply, smul_eq_mul, Finset.mul_sum,
_root_.mul_assoc, Algebra.left_comm])
(by
simp_rw [toFunLinear, lift.tmul, toFunBilinear_apply,
Matrix.map_one (algebraMap R A) (map_zero _) (map_one _), one_smul])
#align matrix_equiv_tensor.to_fun_alg_hom MatrixEquivTensor.toFunAlgHom
@[simp]
theorem toFunAlgHom_apply (a : A) (m : Matrix n n R) :
toFunAlgHom R A n (a ⊗ₜ m) = a • m.map (algebraMap R A) := rfl
#align matrix_equiv_tensor.to_fun_alg_hom_apply MatrixEquivTensor.toFunAlgHom_apply
def invFun (M : Matrix n n A) : A ⊗[R] Matrix n n R :=
∑ p : n × n, M p.1 p.2 ⊗ₜ stdBasisMatrix p.1 p.2 1
#align matrix_equiv_tensor.inv_fun MatrixEquivTensor.invFun
@[simp]
| Mathlib/RingTheory/MatrixAlgebra.lean | 89 | 89 | theorem invFun_zero : invFun R A n 0 = 0 := by | simp [invFun]
|
import Mathlib.Algebra.Polynomial.Div
import Mathlib.Logic.Function.Basic
import Mathlib.RingTheory.Localization.FractionRing
import Mathlib.Tactic.FieldSimp
import Mathlib.Tactic.LinearCombination
#align_import data.polynomial.partial_fractions from "leanprover-community/mathlib"@"6e70e0d419bf686784937d64ed4bfde866ff229e"
variable (R : Type) [CommRing R] [IsDomain R]
open Polynomial
variable (K : Type) [Field K] [Algebra R[X] K] [IsFractionRing R[X] K]
section TwoDenominators
-- Porting note: added for scoped `Algebra.cast` instance
open algebraMap
| Mathlib/Algebra/Polynomial/PartialFractions.lean | 60 | 79 | theorem div_eq_quo_add_rem_div_add_rem_div (f : R[X]) {g₁ g₂ : R[X]} (hg₁ : g₁.Monic)
(hg₂ : g₂.Monic) (hcoprime : IsCoprime g₁ g₂) :
∃ q r₁ r₂ : R[X],
r₁.degree < g₁.degree ∧
r₂.degree < g₂.degree ∧ (f : K) / (↑g₁ * ↑g₂) = ↑q + ↑r₁ / ↑g₁ + ↑r₂ / ↑g₂ := by |
rcases hcoprime with ⟨c, d, hcd⟩
refine
⟨f * d /ₘ g₁ + f * c /ₘ g₂, f * d %ₘ g₁, f * c %ₘ g₂, degree_modByMonic_lt _ hg₁,
degree_modByMonic_lt _ hg₂, ?_⟩
have hg₁' : (↑g₁ : K) ≠ 0 := by
norm_cast
exact hg₁.ne_zero
have hg₂' : (↑g₂ : K) ≠ 0 := by
norm_cast
exact hg₂.ne_zero
have hfc := modByMonic_add_div (f * c) hg₂
have hfd := modByMonic_add_div (f * d) hg₁
field_simp
norm_cast
linear_combination -1 * f * hcd + -1 * g₁ * hfc + -1 * g₂ * hfd
|
import Mathlib.LinearAlgebra.ExteriorAlgebra.Basic
import Mathlib.LinearAlgebra.CliffordAlgebra.Fold
import Mathlib.LinearAlgebra.CliffordAlgebra.Conjugation
import Mathlib.LinearAlgebra.Dual
#align_import linear_algebra.clifford_algebra.contraction from "leanprover-community/mathlib"@"70fd9563a21e7b963887c9360bd29b2393e6225a"
open LinearMap (BilinForm)
universe u1 u2 u3
variable {R : Type u1} [CommRing R]
variable {M : Type u2} [AddCommGroup M] [Module R M]
variable (Q : QuadraticForm R M)
namespace CliffordAlgebra
section contractLeft
variable (d d' : Module.Dual R M)
@[simps!]
def contractLeftAux (d : Module.Dual R M) :
M →ₗ[R] CliffordAlgebra Q × CliffordAlgebra Q →ₗ[R] CliffordAlgebra Q :=
haveI v_mul := (Algebra.lmul R (CliffordAlgebra Q)).toLinearMap ∘ₗ ι Q
d.smulRight (LinearMap.fst _ (CliffordAlgebra Q) (CliffordAlgebra Q)) -
v_mul.compl₂ (LinearMap.snd _ (CliffordAlgebra Q) _)
#align clifford_algebra.contract_left_aux CliffordAlgebra.contractLeftAux
theorem contractLeftAux_contractLeftAux (v : M) (x : CliffordAlgebra Q) (fx : CliffordAlgebra Q) :
contractLeftAux Q d v (ι Q v * x, contractLeftAux Q d v (x, fx)) = Q v • fx := by
simp only [contractLeftAux_apply_apply]
rw [mul_sub, ← mul_assoc, ι_sq_scalar, ← Algebra.smul_def, ← sub_add, mul_smul_comm, sub_self,
zero_add]
#align clifford_algebra.contract_left_aux_contract_left_aux CliffordAlgebra.contractLeftAux_contractLeftAux
variable {Q}
def contractLeft : Module.Dual R M →ₗ[R] CliffordAlgebra Q →ₗ[R] CliffordAlgebra Q where
toFun d := foldr' Q (contractLeftAux Q d) (contractLeftAux_contractLeftAux Q d) 0
map_add' d₁ d₂ :=
LinearMap.ext fun x => by
dsimp only
rw [LinearMap.add_apply]
induction' x using CliffordAlgebra.left_induction with r x y hx hy m x hx
· simp_rw [foldr'_algebraMap, smul_zero, zero_add]
· rw [map_add, map_add, map_add, add_add_add_comm, hx, hy]
· rw [foldr'_ι_mul, foldr'_ι_mul, foldr'_ι_mul, hx]
dsimp only [contractLeftAux_apply_apply]
rw [sub_add_sub_comm, mul_add, LinearMap.add_apply, add_smul]
map_smul' c d :=
LinearMap.ext fun x => by
dsimp only
rw [LinearMap.smul_apply, RingHom.id_apply]
induction' x using CliffordAlgebra.left_induction with r x y hx hy m x hx
· simp_rw [foldr'_algebraMap, smul_zero]
· rw [map_add, map_add, smul_add, hx, hy]
· rw [foldr'_ι_mul, foldr'_ι_mul, hx]
dsimp only [contractLeftAux_apply_apply]
rw [LinearMap.smul_apply, smul_assoc, mul_smul_comm, smul_sub]
#align clifford_algebra.contract_left CliffordAlgebra.contractLeft
def contractRight : CliffordAlgebra Q →ₗ[R] Module.Dual R M →ₗ[R] CliffordAlgebra Q :=
LinearMap.flip (LinearMap.compl₂ (LinearMap.compr₂ contractLeft reverse) reverse)
#align clifford_algebra.contract_right CliffordAlgebra.contractRight
theorem contractRight_eq (x : CliffordAlgebra Q) :
contractRight (Q := Q) x d = reverse (contractLeft (R := R) (M := M) d <| reverse x) :=
rfl
#align clifford_algebra.contract_right_eq CliffordAlgebra.contractRight_eq
local infixl:70 "⌋" => contractLeft (R := R) (M := M)
local infixl:70 "⌊" => contractRight (R := R) (M := M) (Q := Q)
-- Porting note: Lean needs to be reminded of this instance otherwise the statement of the
-- next result times out
instance : SMul R (CliffordAlgebra Q) := inferInstance
| Mathlib/LinearAlgebra/CliffordAlgebra/Contraction.lean | 130 | 134 | theorem contractLeft_ι_mul (a : M) (b : CliffordAlgebra Q) :
d⌋(ι Q a * b) = d a • b - ι Q a * (d⌋b) := by |
-- Porting note: Lean cannot figure out anymore the third argument
refine foldr'_ι_mul _ _ ?_ _ _ _
exact fun m x fx ↦ contractLeftAux_contractLeftAux Q d m x fx
|
import Mathlib.Data.Matrix.Basic
variable {l m n o : Type*}
universe u v w
variable {R : Type*} {α : Type v} {β : Type w}
namespace Matrix
def col (w : m → α) : Matrix m Unit α :=
of fun x _ => w x
#align matrix.col Matrix.col
-- TODO: set as an equation lemma for `col`, see mathlib4#3024
@[simp]
theorem col_apply (w : m → α) (i j) : col w i j = w i :=
rfl
#align matrix.col_apply Matrix.col_apply
def row (v : n → α) : Matrix Unit n α :=
of fun _ y => v y
#align matrix.row Matrix.row
-- TODO: set as an equation lemma for `row`, see mathlib4#3024
@[simp]
theorem row_apply (v : n → α) (i j) : row v i j = v j :=
rfl
#align matrix.row_apply Matrix.row_apply
theorem col_injective : Function.Injective (col : (m → α) → _) :=
fun _x _y h => funext fun i => congr_fun₂ h i ()
@[simp] theorem col_inj {v w : m → α} : col v = col w ↔ v = w := col_injective.eq_iff
@[simp] theorem col_zero [Zero α] : col (0 : m → α) = 0 := rfl
@[simp] theorem col_eq_zero [Zero α] (v : m → α) : col v = 0 ↔ v = 0 := col_inj
@[simp]
theorem col_add [Add α] (v w : m → α) : col (v + w) = col v + col w := by
ext
rfl
#align matrix.col_add Matrix.col_add
@[simp]
theorem col_smul [SMul R α] (x : R) (v : m → α) : col (x • v) = x • col v := by
ext
rfl
#align matrix.col_smul Matrix.col_smul
theorem row_injective : Function.Injective (row : (n → α) → _) :=
fun _x _y h => funext fun j => congr_fun₂ h () j
@[simp] theorem row_inj {v w : n → α} : row v = row w ↔ v = w := row_injective.eq_iff
@[simp] theorem row_zero [Zero α] : row (0 : n → α) = 0 := rfl
@[simp] theorem row_eq_zero [Zero α] (v : n → α) : row v = 0 ↔ v = 0 := row_inj
@[simp]
theorem row_add [Add α] (v w : m → α) : row (v + w) = row v + row w := by
ext
rfl
#align matrix.row_add Matrix.row_add
@[simp]
theorem row_smul [SMul R α] (x : R) (v : m → α) : row (x • v) = x • row v := by
ext
rfl
#align matrix.row_smul Matrix.row_smul
@[simp]
theorem transpose_col (v : m → α) : (Matrix.col v)ᵀ = Matrix.row v := by
ext
rfl
#align matrix.transpose_col Matrix.transpose_col
@[simp]
theorem transpose_row (v : m → α) : (Matrix.row v)ᵀ = Matrix.col v := by
ext
rfl
#align matrix.transpose_row Matrix.transpose_row
@[simp]
theorem conjTranspose_col [Star α] (v : m → α) : (col v)ᴴ = row (star v) := by
ext
rfl
#align matrix.conj_transpose_col Matrix.conjTranspose_col
@[simp]
theorem conjTranspose_row [Star α] (v : m → α) : (row v)ᴴ = col (star v) := by
ext
rfl
#align matrix.conj_transpose_row Matrix.conjTranspose_row
| Mathlib/Data/Matrix/RowCol.lean | 117 | 120 | theorem row_vecMul [Fintype m] [NonUnitalNonAssocSemiring α] (M : Matrix m n α) (v : m → α) :
Matrix.row (v ᵥ* M) = Matrix.row v * M := by |
ext
rfl
|
import Mathlib.Order.ConditionallyCompleteLattice.Basic
import Mathlib.Data.Int.LeastGreatest
#align_import data.int.conditionally_complete_order from "leanprover-community/mathlib"@"1e05171a5e8cf18d98d9cf7b207540acb044acae"
open Int
noncomputable section
open scoped Classical
instance instConditionallyCompleteLinearOrder : ConditionallyCompleteLinearOrder ℤ where
__ := instLinearOrder
__ := LinearOrder.toLattice
sSup s :=
if h : s.Nonempty ∧ BddAbove s then
greatestOfBdd (Classical.choose h.2) (Classical.choose_spec h.2) h.1
else 0
sInf s :=
if h : s.Nonempty ∧ BddBelow s then
leastOfBdd (Classical.choose h.2) (Classical.choose_spec h.2) h.1
else 0
le_csSup s n hs hns := by
have : s.Nonempty ∧ BddAbove s := ⟨⟨n, hns⟩, hs⟩
-- Porting note: this was `rw [dif_pos this]`
simp only [this, and_self, dite_true, ge_iff_le]
exact (greatestOfBdd _ _ _).2.2 n hns
csSup_le s n hs hns := by
have : s.Nonempty ∧ BddAbove s := ⟨hs, ⟨n, hns⟩⟩
-- Porting note: this was `rw [dif_pos this]`
simp only [this, and_self, dite_true, ge_iff_le]
exact hns (greatestOfBdd _ (Classical.choose_spec this.2) _).2.1
csInf_le s n hs hns := by
have : s.Nonempty ∧ BddBelow s := ⟨⟨n, hns⟩, hs⟩
-- Porting note: this was `rw [dif_pos this]`
simp only [this, and_self, dite_true, ge_iff_le]
exact (leastOfBdd _ _ _).2.2 n hns
le_csInf s n hs hns := by
have : s.Nonempty ∧ BddBelow s := ⟨hs, ⟨n, hns⟩⟩
-- Porting note: this was `rw [dif_pos this]`
simp only [this, and_self, dite_true, ge_iff_le]
exact hns (leastOfBdd _ (Classical.choose_spec this.2) _).2.1
csSup_of_not_bddAbove := fun s hs ↦ by simp [hs]
csInf_of_not_bddBelow := fun s hs ↦ by simp [hs]
namespace Int
-- Porting note: mathlib3 proof uses `convert dif_pos _ using 1`
theorem csSup_eq_greatest_of_bdd {s : Set ℤ} [DecidablePred (· ∈ s)] (b : ℤ) (Hb : ∀ z ∈ s, z ≤ b)
(Hinh : ∃ z : ℤ, z ∈ s) : sSup s = greatestOfBdd b Hb Hinh := by
have : s.Nonempty ∧ BddAbove s := ⟨Hinh, b, Hb⟩
simp only [sSup, this, and_self, dite_true]
convert (coe_greatestOfBdd_eq Hb (Classical.choose_spec (⟨b, Hb⟩ : BddAbove s)) Hinh).symm
#align int.cSup_eq_greatest_of_bdd Int.csSup_eq_greatest_of_bdd
@[simp]
theorem csSup_empty : sSup (∅ : Set ℤ) = 0 :=
dif_neg (by simp)
#align int.cSup_empty Int.csSup_empty
theorem csSup_of_not_bdd_above {s : Set ℤ} (h : ¬BddAbove s) : sSup s = 0 :=
dif_neg (by simp [h])
#align int.cSup_of_not_bdd_above Int.csSup_of_not_bdd_above
-- Porting note: mathlib3 proof uses `convert dif_pos _ using 1`
theorem csInf_eq_least_of_bdd {s : Set ℤ} [DecidablePred (· ∈ s)] (b : ℤ) (Hb : ∀ z ∈ s, b ≤ z)
(Hinh : ∃ z : ℤ, z ∈ s) : sInf s = leastOfBdd b Hb Hinh := by
have : s.Nonempty ∧ BddBelow s := ⟨Hinh, b, Hb⟩
simp only [sInf, this, and_self, dite_true]
convert (coe_leastOfBdd_eq Hb (Classical.choose_spec (⟨b, Hb⟩ : BddBelow s)) Hinh).symm
#align int.cInf_eq_least_of_bdd Int.csInf_eq_least_of_bdd
@[simp]
theorem csInf_empty : sInf (∅ : Set ℤ) = 0 :=
dif_neg (by simp)
#align int.cInf_empty Int.csInf_empty
theorem csInf_of_not_bdd_below {s : Set ℤ} (h : ¬BddBelow s) : sInf s = 0 :=
dif_neg (by simp [h])
#align int.cInf_of_not_bdd_below Int.csInf_of_not_bdd_below
theorem csSup_mem {s : Set ℤ} (h1 : s.Nonempty) (h2 : BddAbove s) : sSup s ∈ s := by
convert (greatestOfBdd _ (Classical.choose_spec h2) h1).2.1
exact dif_pos ⟨h1, h2⟩
#align int.cSup_mem Int.csSup_mem
| Mathlib/Data/Int/ConditionallyCompleteOrder.lean | 99 | 101 | theorem csInf_mem {s : Set ℤ} (h1 : s.Nonempty) (h2 : BddBelow s) : sInf s ∈ s := by |
convert (leastOfBdd _ (Classical.choose_spec h2) h1).2.1
exact dif_pos ⟨h1, h2⟩
|
import Mathlib.Topology.Separation
import Mathlib.Topology.UniformSpace.Basic
import Mathlib.Topology.UniformSpace.Cauchy
#align_import topology.uniform_space.uniform_convergence from "leanprover-community/mathlib"@"2705404e701abc6b3127da906f40bae062a169c9"
noncomputable section
open Topology Uniformity Filter Set
universe u v w x
variable {α : Type u} {β : Type v} {γ : Type w} {ι : Type x} [UniformSpace β]
variable {F : ι → α → β} {f : α → β} {s s' : Set α} {x : α} {p : Filter ι} {p' : Filter α}
{g : ι → α}
def TendstoUniformlyOnFilter (F : ι → α → β) (f : α → β) (p : Filter ι) (p' : Filter α) :=
∀ u ∈ 𝓤 β, ∀ᶠ n : ι × α in p ×ˢ p', (f n.snd, F n.fst n.snd) ∈ u
#align tendsto_uniformly_on_filter TendstoUniformlyOnFilter
theorem tendstoUniformlyOnFilter_iff_tendsto :
TendstoUniformlyOnFilter F f p p' ↔
Tendsto (fun q : ι × α => (f q.2, F q.1 q.2)) (p ×ˢ p') (𝓤 β) :=
Iff.rfl
#align tendsto_uniformly_on_filter_iff_tendsto tendstoUniformlyOnFilter_iff_tendsto
def TendstoUniformlyOn (F : ι → α → β) (f : α → β) (p : Filter ι) (s : Set α) :=
∀ u ∈ 𝓤 β, ∀ᶠ n in p, ∀ x : α, x ∈ s → (f x, F n x) ∈ u
#align tendsto_uniformly_on TendstoUniformlyOn
theorem tendstoUniformlyOn_iff_tendstoUniformlyOnFilter :
TendstoUniformlyOn F f p s ↔ TendstoUniformlyOnFilter F f p (𝓟 s) := by
simp only [TendstoUniformlyOn, TendstoUniformlyOnFilter]
apply forall₂_congr
simp_rw [eventually_prod_principal_iff]
simp
#align tendsto_uniformly_on_iff_tendsto_uniformly_on_filter tendstoUniformlyOn_iff_tendstoUniformlyOnFilter
alias ⟨TendstoUniformlyOn.tendstoUniformlyOnFilter, TendstoUniformlyOnFilter.tendstoUniformlyOn⟩ :=
tendstoUniformlyOn_iff_tendstoUniformlyOnFilter
#align tendsto_uniformly_on.tendsto_uniformly_on_filter TendstoUniformlyOn.tendstoUniformlyOnFilter
#align tendsto_uniformly_on_filter.tendsto_uniformly_on TendstoUniformlyOnFilter.tendstoUniformlyOn
theorem tendstoUniformlyOn_iff_tendsto {F : ι → α → β} {f : α → β} {p : Filter ι} {s : Set α} :
TendstoUniformlyOn F f p s ↔
Tendsto (fun q : ι × α => (f q.2, F q.1 q.2)) (p ×ˢ 𝓟 s) (𝓤 β) := by
simp [tendstoUniformlyOn_iff_tendstoUniformlyOnFilter, tendstoUniformlyOnFilter_iff_tendsto]
#align tendsto_uniformly_on_iff_tendsto tendstoUniformlyOn_iff_tendsto
def TendstoUniformly (F : ι → α → β) (f : α → β) (p : Filter ι) :=
∀ u ∈ 𝓤 β, ∀ᶠ n in p, ∀ x : α, (f x, F n x) ∈ u
#align tendsto_uniformly TendstoUniformly
-- Porting note: moved from below
theorem tendstoUniformlyOn_univ : TendstoUniformlyOn F f p univ ↔ TendstoUniformly F f p := by
simp [TendstoUniformlyOn, TendstoUniformly]
#align tendsto_uniformly_on_univ tendstoUniformlyOn_univ
theorem tendstoUniformly_iff_tendstoUniformlyOnFilter :
TendstoUniformly F f p ↔ TendstoUniformlyOnFilter F f p ⊤ := by
rw [← tendstoUniformlyOn_univ, tendstoUniformlyOn_iff_tendstoUniformlyOnFilter, principal_univ]
#align tendsto_uniformly_iff_tendsto_uniformly_on_filter tendstoUniformly_iff_tendstoUniformlyOnFilter
theorem TendstoUniformly.tendstoUniformlyOnFilter (h : TendstoUniformly F f p) :
TendstoUniformlyOnFilter F f p ⊤ := by rwa [← tendstoUniformly_iff_tendstoUniformlyOnFilter]
#align tendsto_uniformly.tendsto_uniformly_on_filter TendstoUniformly.tendstoUniformlyOnFilter
theorem tendstoUniformlyOn_iff_tendstoUniformly_comp_coe :
TendstoUniformlyOn F f p s ↔ TendstoUniformly (fun i (x : s) => F i x) (f ∘ (↑)) p :=
forall₂_congr fun u _ => by simp
#align tendsto_uniformly_on_iff_tendsto_uniformly_comp_coe tendstoUniformlyOn_iff_tendstoUniformly_comp_coe
theorem tendstoUniformly_iff_tendsto {F : ι → α → β} {f : α → β} {p : Filter ι} :
TendstoUniformly F f p ↔ Tendsto (fun q : ι × α => (f q.2, F q.1 q.2)) (p ×ˢ ⊤) (𝓤 β) := by
simp [tendstoUniformly_iff_tendstoUniformlyOnFilter, tendstoUniformlyOnFilter_iff_tendsto]
#align tendsto_uniformly_iff_tendsto tendstoUniformly_iff_tendsto
theorem TendstoUniformlyOnFilter.tendsto_at (h : TendstoUniformlyOnFilter F f p p')
(hx : 𝓟 {x} ≤ p') : Tendsto (fun n => F n x) p <| 𝓝 (f x) := by
refine Uniform.tendsto_nhds_right.mpr fun u hu => mem_map.mpr ?_
filter_upwards [(h u hu).curry]
intro i h
simpa using h.filter_mono hx
#align tendsto_uniformly_on_filter.tendsto_at TendstoUniformlyOnFilter.tendsto_at
theorem TendstoUniformlyOn.tendsto_at (h : TendstoUniformlyOn F f p s) {x : α} (hx : x ∈ s) :
Tendsto (fun n => F n x) p <| 𝓝 (f x) :=
h.tendstoUniformlyOnFilter.tendsto_at
(le_principal_iff.mpr <| mem_principal.mpr <| singleton_subset_iff.mpr <| hx)
#align tendsto_uniformly_on.tendsto_at TendstoUniformlyOn.tendsto_at
theorem TendstoUniformly.tendsto_at (h : TendstoUniformly F f p) (x : α) :
Tendsto (fun n => F n x) p <| 𝓝 (f x) :=
h.tendstoUniformlyOnFilter.tendsto_at le_top
#align tendsto_uniformly.tendsto_at TendstoUniformly.tendsto_at
-- Porting note: tendstoUniformlyOn_univ moved up
theorem TendstoUniformlyOnFilter.mono_left {p'' : Filter ι} (h : TendstoUniformlyOnFilter F f p p')
(hp : p'' ≤ p) : TendstoUniformlyOnFilter F f p'' p' := fun u hu =>
(h u hu).filter_mono (p'.prod_mono_left hp)
#align tendsto_uniformly_on_filter.mono_left TendstoUniformlyOnFilter.mono_left
theorem TendstoUniformlyOnFilter.mono_right {p'' : Filter α} (h : TendstoUniformlyOnFilter F f p p')
(hp : p'' ≤ p') : TendstoUniformlyOnFilter F f p p'' := fun u hu =>
(h u hu).filter_mono (p.prod_mono_right hp)
#align tendsto_uniformly_on_filter.mono_right TendstoUniformlyOnFilter.mono_right
theorem TendstoUniformlyOn.mono {s' : Set α} (h : TendstoUniformlyOn F f p s) (h' : s' ⊆ s) :
TendstoUniformlyOn F f p s' :=
tendstoUniformlyOn_iff_tendstoUniformlyOnFilter.mpr
(h.tendstoUniformlyOnFilter.mono_right (le_principal_iff.mpr <| mem_principal.mpr h'))
#align tendsto_uniformly_on.mono TendstoUniformlyOn.mono
theorem TendstoUniformlyOnFilter.congr {F' : ι → α → β} (hf : TendstoUniformlyOnFilter F f p p')
(hff' : ∀ᶠ n : ι × α in p ×ˢ p', F n.fst n.snd = F' n.fst n.snd) :
TendstoUniformlyOnFilter F' f p p' := by
refine fun u hu => ((hf u hu).and hff').mono fun n h => ?_
rw [← h.right]
exact h.left
#align tendsto_uniformly_on_filter.congr TendstoUniformlyOnFilter.congr
theorem TendstoUniformlyOn.congr {F' : ι → α → β} (hf : TendstoUniformlyOn F f p s)
(hff' : ∀ᶠ n in p, Set.EqOn (F n) (F' n) s) : TendstoUniformlyOn F' f p s := by
rw [tendstoUniformlyOn_iff_tendstoUniformlyOnFilter] at hf ⊢
refine hf.congr ?_
rw [eventually_iff] at hff' ⊢
simp only [Set.EqOn] at hff'
simp only [mem_prod_principal, hff', mem_setOf_eq]
#align tendsto_uniformly_on.congr TendstoUniformlyOn.congr
theorem TendstoUniformlyOn.congr_right {g : α → β} (hf : TendstoUniformlyOn F f p s)
(hfg : EqOn f g s) : TendstoUniformlyOn F g p s := fun u hu => by
filter_upwards [hf u hu] with i hi a ha using hfg ha ▸ hi a ha
#align tendsto_uniformly_on.congr_right TendstoUniformlyOn.congr_right
protected theorem TendstoUniformly.tendstoUniformlyOn (h : TendstoUniformly F f p) :
TendstoUniformlyOn F f p s :=
(tendstoUniformlyOn_univ.2 h).mono (subset_univ s)
#align tendsto_uniformly.tendsto_uniformly_on TendstoUniformly.tendstoUniformlyOn
theorem TendstoUniformlyOnFilter.comp (h : TendstoUniformlyOnFilter F f p p') (g : γ → α) :
TendstoUniformlyOnFilter (fun n => F n ∘ g) (f ∘ g) p (p'.comap g) := by
rw [tendstoUniformlyOnFilter_iff_tendsto] at h ⊢
exact h.comp (tendsto_id.prod_map tendsto_comap)
#align tendsto_uniformly_on_filter.comp TendstoUniformlyOnFilter.comp
theorem TendstoUniformlyOn.comp (h : TendstoUniformlyOn F f p s) (g : γ → α) :
TendstoUniformlyOn (fun n => F n ∘ g) (f ∘ g) p (g ⁻¹' s) := by
rw [tendstoUniformlyOn_iff_tendstoUniformlyOnFilter] at h ⊢
simpa [TendstoUniformlyOn, comap_principal] using TendstoUniformlyOnFilter.comp h g
#align tendsto_uniformly_on.comp TendstoUniformlyOn.comp
theorem TendstoUniformly.comp (h : TendstoUniformly F f p) (g : γ → α) :
TendstoUniformly (fun n => F n ∘ g) (f ∘ g) p := by
rw [tendstoUniformly_iff_tendstoUniformlyOnFilter] at h ⊢
simpa [principal_univ, comap_principal] using h.comp g
#align tendsto_uniformly.comp TendstoUniformly.comp
theorem UniformContinuous.comp_tendstoUniformlyOnFilter [UniformSpace γ] {g : β → γ}
(hg : UniformContinuous g) (h : TendstoUniformlyOnFilter F f p p') :
TendstoUniformlyOnFilter (fun i => g ∘ F i) (g ∘ f) p p' := fun _u hu => h _ (hg hu)
#align uniform_continuous.comp_tendsto_uniformly_on_filter UniformContinuous.comp_tendstoUniformlyOnFilter
theorem UniformContinuous.comp_tendstoUniformlyOn [UniformSpace γ] {g : β → γ}
(hg : UniformContinuous g) (h : TendstoUniformlyOn F f p s) :
TendstoUniformlyOn (fun i => g ∘ F i) (g ∘ f) p s := fun _u hu => h _ (hg hu)
#align uniform_continuous.comp_tendsto_uniformly_on UniformContinuous.comp_tendstoUniformlyOn
theorem UniformContinuous.comp_tendstoUniformly [UniformSpace γ] {g : β → γ}
(hg : UniformContinuous g) (h : TendstoUniformly F f p) :
TendstoUniformly (fun i => g ∘ F i) (g ∘ f) p := fun _u hu => h _ (hg hu)
#align uniform_continuous.comp_tendsto_uniformly UniformContinuous.comp_tendstoUniformly
theorem TendstoUniformlyOnFilter.prod_map {ι' α' β' : Type*} [UniformSpace β'] {F' : ι' → α' → β'}
{f' : α' → β'} {q : Filter ι'} {q' : Filter α'} (h : TendstoUniformlyOnFilter F f p p')
(h' : TendstoUniformlyOnFilter F' f' q q') :
TendstoUniformlyOnFilter (fun i : ι × ι' => Prod.map (F i.1) (F' i.2)) (Prod.map f f')
(p ×ˢ q) (p' ×ˢ q') := by
rw [tendstoUniformlyOnFilter_iff_tendsto] at h h' ⊢
rw [uniformity_prod_eq_comap_prod, tendsto_comap_iff, ← map_swap4_prod, tendsto_map'_iff]
convert h.prod_map h' -- seems to be faster than `exact` here
#align tendsto_uniformly_on_filter.prod_map TendstoUniformlyOnFilter.prod_map
| Mathlib/Topology/UniformSpace/UniformConvergence.lean | 283 | 289 | theorem TendstoUniformlyOn.prod_map {ι' α' β' : Type*} [UniformSpace β'] {F' : ι' → α' → β'}
{f' : α' → β'} {p' : Filter ι'} {s' : Set α'} (h : TendstoUniformlyOn F f p s)
(h' : TendstoUniformlyOn F' f' p' s') :
TendstoUniformlyOn (fun i : ι × ι' => Prod.map (F i.1) (F' i.2)) (Prod.map f f') (p ×ˢ p')
(s ×ˢ s') := by |
rw [tendstoUniformlyOn_iff_tendstoUniformlyOnFilter] at h h' ⊢
simpa only [prod_principal_principal] using h.prod_map h'
|
import Mathlib.Analysis.SpecificLimits.Basic
import Mathlib.Data.Setoid.Basic
import Mathlib.Dynamics.FixedPoints.Topology
import Mathlib.Topology.MetricSpace.Lipschitz
#align_import topology.metric_space.contracting from "leanprover-community/mathlib"@"f2ce6086713c78a7f880485f7917ea547a215982"
open scoped Classical
open NNReal Topology ENNReal Filter Function
variable {α : Type*}
def ContractingWith [EMetricSpace α] (K : ℝ≥0) (f : α → α) :=
K < 1 ∧ LipschitzWith K f
#align contracting_with ContractingWith
namespace ContractingWith
variable [EMetricSpace α] [cs : CompleteSpace α] {K : ℝ≥0} {f : α → α}
open EMetric Set
theorem toLipschitzWith (hf : ContractingWith K f) : LipschitzWith K f := hf.2
#align contracting_with.to_lipschitz_with ContractingWith.toLipschitzWith
theorem one_sub_K_pos' (hf : ContractingWith K f) : (0 : ℝ≥0∞) < 1 - K := by simp [hf.1]
set_option linter.uppercaseLean3 false in
#align contracting_with.one_sub_K_pos' ContractingWith.one_sub_K_pos'
theorem one_sub_K_ne_zero (hf : ContractingWith K f) : (1 : ℝ≥0∞) - K ≠ 0 :=
ne_of_gt hf.one_sub_K_pos'
set_option linter.uppercaseLean3 false in
#align contracting_with.one_sub_K_ne_zero ContractingWith.one_sub_K_ne_zero
theorem one_sub_K_ne_top : (1 : ℝ≥0∞) - K ≠ ∞ := by
norm_cast
exact ENNReal.coe_ne_top
set_option linter.uppercaseLean3 false in
#align contracting_with.one_sub_K_ne_top ContractingWith.one_sub_K_ne_top
| Mathlib/Topology/MetricSpace/Contracting.lean | 68 | 76 | theorem edist_inequality (hf : ContractingWith K f) {x y} (h : edist x y ≠ ∞) :
edist x y ≤ (edist x (f x) + edist y (f y)) / (1 - K) :=
suffices edist x y ≤ edist x (f x) + edist y (f y) + K * edist x y by
rwa [ENNReal.le_div_iff_mul_le (Or.inl hf.one_sub_K_ne_zero) (Or.inl one_sub_K_ne_top),
mul_comm, ENNReal.sub_mul fun _ _ ↦ h, one_mul, tsub_le_iff_right]
calc
edist x y ≤ edist x (f x) + edist (f x) (f y) + edist (f y) y := edist_triangle4 _ _ _ _
_ = edist x (f x) + edist y (f y) + edist (f x) (f y) := by | rw [edist_comm y, add_right_comm]
_ ≤ edist x (f x) + edist y (f y) + K * edist x y := add_le_add le_rfl (hf.2 _ _)
|
import Mathlib.Data.Nat.Defs
import Mathlib.Data.Option.Basic
import Mathlib.Data.List.Defs
import Mathlib.Init.Data.List.Basic
import Mathlib.Init.Data.List.Instances
import Mathlib.Init.Data.List.Lemmas
import Mathlib.Logic.Unique
import Mathlib.Order.Basic
import Mathlib.Tactic.Common
#align_import data.list.basic from "leanprover-community/mathlib"@"65a1391a0106c9204fe45bc73a039f056558cb83"
assert_not_exists Set.range
assert_not_exists GroupWithZero
assert_not_exists Ring
open Function
open Nat hiding one_pos
namespace List
universe u v w
variable {ι : Type*} {α : Type u} {β : Type v} {γ : Type w} {l₁ l₂ : List α}
-- Porting note: Delete this attribute
-- attribute [inline] List.head!
instance uniqueOfIsEmpty [IsEmpty α] : Unique (List α) :=
{ instInhabitedList with
uniq := fun l =>
match l with
| [] => rfl
| a :: _ => isEmptyElim a }
#align list.unique_of_is_empty List.uniqueOfIsEmpty
instance : Std.LawfulIdentity (α := List α) Append.append [] where
left_id := nil_append
right_id := append_nil
instance : Std.Associative (α := List α) Append.append where
assoc := append_assoc
#align list.cons_ne_nil List.cons_ne_nil
#align list.cons_ne_self List.cons_ne_self
#align list.head_eq_of_cons_eq List.head_eq_of_cons_eqₓ -- implicits order
#align list.tail_eq_of_cons_eq List.tail_eq_of_cons_eqₓ -- implicits order
@[simp] theorem cons_injective {a : α} : Injective (cons a) := fun _ _ => tail_eq_of_cons_eq
#align list.cons_injective List.cons_injective
#align list.cons_inj List.cons_inj
#align list.cons_eq_cons List.cons_eq_cons
theorem singleton_injective : Injective fun a : α => [a] := fun _ _ h => (cons_eq_cons.1 h).1
#align list.singleton_injective List.singleton_injective
theorem singleton_inj {a b : α} : [a] = [b] ↔ a = b :=
singleton_injective.eq_iff
#align list.singleton_inj List.singleton_inj
#align list.exists_cons_of_ne_nil List.exists_cons_of_ne_nil
theorem set_of_mem_cons (l : List α) (a : α) : { x | x ∈ a :: l } = insert a { x | x ∈ l } :=
Set.ext fun _ => mem_cons
#align list.set_of_mem_cons List.set_of_mem_cons
#align list.mem_singleton_self List.mem_singleton_self
#align list.eq_of_mem_singleton List.eq_of_mem_singleton
#align list.mem_singleton List.mem_singleton
#align list.mem_of_mem_cons_of_mem List.mem_of_mem_cons_of_mem
theorem _root_.Decidable.List.eq_or_ne_mem_of_mem [DecidableEq α]
{a b : α} {l : List α} (h : a ∈ b :: l) : a = b ∨ a ≠ b ∧ a ∈ l := by
by_cases hab : a = b
· exact Or.inl hab
· exact ((List.mem_cons.1 h).elim Or.inl (fun h => Or.inr ⟨hab, h⟩))
#align decidable.list.eq_or_ne_mem_of_mem Decidable.List.eq_or_ne_mem_of_mem
#align list.eq_or_ne_mem_of_mem List.eq_or_ne_mem_of_mem
#align list.not_mem_append List.not_mem_append
#align list.ne_nil_of_mem List.ne_nil_of_mem
lemma mem_pair {a b c : α} : a ∈ [b, c] ↔ a = b ∨ a = c := by
rw [mem_cons, mem_singleton]
@[deprecated (since := "2024-03-23")] alias mem_split := append_of_mem
#align list.mem_split List.append_of_mem
#align list.mem_of_ne_of_mem List.mem_of_ne_of_mem
#align list.ne_of_not_mem_cons List.ne_of_not_mem_cons
#align list.not_mem_of_not_mem_cons List.not_mem_of_not_mem_cons
#align list.not_mem_cons_of_ne_of_not_mem List.not_mem_cons_of_ne_of_not_mem
#align list.ne_and_not_mem_of_not_mem_cons List.ne_and_not_mem_of_not_mem_cons
#align list.mem_map List.mem_map
#align list.exists_of_mem_map List.exists_of_mem_map
#align list.mem_map_of_mem List.mem_map_of_memₓ -- implicits order
-- The simpNF linter says that the LHS can be simplified via `List.mem_map`.
-- However this is a higher priority lemma.
-- https://github.com/leanprover/std4/issues/207
@[simp 1100, nolint simpNF]
theorem mem_map_of_injective {f : α → β} (H : Injective f) {a : α} {l : List α} :
f a ∈ map f l ↔ a ∈ l :=
⟨fun m => let ⟨_, m', e⟩ := exists_of_mem_map m; H e ▸ m', mem_map_of_mem _⟩
#align list.mem_map_of_injective List.mem_map_of_injective
@[simp]
theorem _root_.Function.Involutive.exists_mem_and_apply_eq_iff {f : α → α}
(hf : Function.Involutive f) (x : α) (l : List α) : (∃ y : α, y ∈ l ∧ f y = x) ↔ f x ∈ l :=
⟨by rintro ⟨y, h, rfl⟩; rwa [hf y], fun h => ⟨f x, h, hf _⟩⟩
#align function.involutive.exists_mem_and_apply_eq_iff Function.Involutive.exists_mem_and_apply_eq_iff
theorem mem_map_of_involutive {f : α → α} (hf : Involutive f) {a : α} {l : List α} :
a ∈ map f l ↔ f a ∈ l := by rw [mem_map, hf.exists_mem_and_apply_eq_iff]
#align list.mem_map_of_involutive List.mem_map_of_involutive
#align list.forall_mem_map_iff List.forall_mem_map_iffₓ -- universe order
#align list.map_eq_nil List.map_eq_nilₓ -- universe order
attribute [simp] List.mem_join
#align list.mem_join List.mem_join
#align list.exists_of_mem_join List.exists_of_mem_join
#align list.mem_join_of_mem List.mem_join_of_memₓ -- implicits order
attribute [simp] List.mem_bind
#align list.mem_bind List.mem_bindₓ -- implicits order
-- Porting note: bExists in Lean3, And in Lean4
#align list.exists_of_mem_bind List.exists_of_mem_bindₓ -- implicits order
#align list.mem_bind_of_mem List.mem_bind_of_memₓ -- implicits order
#align list.bind_map List.bind_mapₓ -- implicits order
theorem map_bind (g : β → List γ) (f : α → β) :
∀ l : List α, (List.map f l).bind g = l.bind fun a => g (f a)
| [] => rfl
| a :: l => by simp only [cons_bind, map_cons, map_bind _ _ l]
#align list.map_bind List.map_bind
#align list.length_eq_zero List.length_eq_zero
#align list.length_singleton List.length_singleton
#align list.length_pos_of_mem List.length_pos_of_mem
#align list.exists_mem_of_length_pos List.exists_mem_of_length_pos
#align list.length_pos_iff_exists_mem List.length_pos_iff_exists_mem
alias ⟨ne_nil_of_length_pos, length_pos_of_ne_nil⟩ := length_pos
#align list.ne_nil_of_length_pos List.ne_nil_of_length_pos
#align list.length_pos_of_ne_nil List.length_pos_of_ne_nil
theorem length_pos_iff_ne_nil {l : List α} : 0 < length l ↔ l ≠ [] :=
⟨ne_nil_of_length_pos, length_pos_of_ne_nil⟩
#align list.length_pos_iff_ne_nil List.length_pos_iff_ne_nil
#align list.exists_mem_of_ne_nil List.exists_mem_of_ne_nil
#align list.length_eq_one List.length_eq_one
theorem exists_of_length_succ {n} : ∀ l : List α, l.length = n + 1 → ∃ h t, l = h :: t
| [], H => absurd H.symm <| succ_ne_zero n
| h :: t, _ => ⟨h, t, rfl⟩
#align list.exists_of_length_succ List.exists_of_length_succ
@[simp] lemma length_injective_iff : Injective (List.length : List α → ℕ) ↔ Subsingleton α := by
constructor
· intro h; refine ⟨fun x y => ?_⟩; (suffices [x] = [y] by simpa using this); apply h; rfl
· intros hα l1 l2 hl
induction l1 generalizing l2 <;> cases l2
· rfl
· cases hl
· cases hl
· next ih _ _ =>
congr
· exact Subsingleton.elim _ _
· apply ih; simpa using hl
#align list.length_injective_iff List.length_injective_iff
@[simp default+1] -- Porting note: this used to be just @[simp]
lemma length_injective [Subsingleton α] : Injective (length : List α → ℕ) :=
length_injective_iff.mpr inferInstance
#align list.length_injective List.length_injective
theorem length_eq_two {l : List α} : l.length = 2 ↔ ∃ a b, l = [a, b] :=
⟨fun _ => let [a, b] := l; ⟨a, b, rfl⟩, fun ⟨_, _, e⟩ => e ▸ rfl⟩
#align list.length_eq_two List.length_eq_two
theorem length_eq_three {l : List α} : l.length = 3 ↔ ∃ a b c, l = [a, b, c] :=
⟨fun _ => let [a, b, c] := l; ⟨a, b, c, rfl⟩, fun ⟨_, _, _, e⟩ => e ▸ rfl⟩
#align list.length_eq_three List.length_eq_three
#align list.sublist.length_le List.Sublist.length_le
-- ADHOC Porting note: instance from Lean3 core
instance instSingletonList : Singleton α (List α) := ⟨fun x => [x]⟩
#align list.has_singleton List.instSingletonList
-- ADHOC Porting note: instance from Lean3 core
instance [DecidableEq α] : Insert α (List α) := ⟨List.insert⟩
-- ADHOC Porting note: instance from Lean3 core
instance [DecidableEq α] : LawfulSingleton α (List α) :=
{ insert_emptyc_eq := fun x =>
show (if x ∈ ([] : List α) then [] else [x]) = [x] from if_neg (not_mem_nil _) }
#align list.empty_eq List.empty_eq
theorem singleton_eq (x : α) : ({x} : List α) = [x] :=
rfl
#align list.singleton_eq List.singleton_eq
theorem insert_neg [DecidableEq α] {x : α} {l : List α} (h : x ∉ l) :
Insert.insert x l = x :: l :=
insert_of_not_mem h
#align list.insert_neg List.insert_neg
theorem insert_pos [DecidableEq α] {x : α} {l : List α} (h : x ∈ l) : Insert.insert x l = l :=
insert_of_mem h
#align list.insert_pos List.insert_pos
theorem doubleton_eq [DecidableEq α] {x y : α} (h : x ≠ y) : ({x, y} : List α) = [x, y] := by
rw [insert_neg, singleton_eq]
rwa [singleton_eq, mem_singleton]
#align list.doubleton_eq List.doubleton_eq
#align list.forall_mem_nil List.forall_mem_nil
#align list.forall_mem_cons List.forall_mem_cons
theorem forall_mem_of_forall_mem_cons {p : α → Prop} {a : α} {l : List α} (h : ∀ x ∈ a :: l, p x) :
∀ x ∈ l, p x := (forall_mem_cons.1 h).2
#align list.forall_mem_of_forall_mem_cons List.forall_mem_of_forall_mem_cons
#align list.forall_mem_singleton List.forall_mem_singleton
#align list.forall_mem_append List.forall_mem_append
#align list.not_exists_mem_nil List.not_exists_mem_nilₓ -- bExists change
-- Porting note: bExists in Lean3 and And in Lean4
theorem exists_mem_cons_of {p : α → Prop} {a : α} (l : List α) (h : p a) : ∃ x ∈ a :: l, p x :=
⟨a, mem_cons_self _ _, h⟩
#align list.exists_mem_cons_of List.exists_mem_cons_ofₓ -- bExists change
-- Porting note: bExists in Lean3 and And in Lean4
theorem exists_mem_cons_of_exists {p : α → Prop} {a : α} {l : List α} : (∃ x ∈ l, p x) →
∃ x ∈ a :: l, p x :=
fun ⟨x, xl, px⟩ => ⟨x, mem_cons_of_mem _ xl, px⟩
#align list.exists_mem_cons_of_exists List.exists_mem_cons_of_existsₓ -- bExists change
-- Porting note: bExists in Lean3 and And in Lean4
theorem or_exists_of_exists_mem_cons {p : α → Prop} {a : α} {l : List α} : (∃ x ∈ a :: l, p x) →
p a ∨ ∃ x ∈ l, p x :=
fun ⟨x, xal, px⟩ =>
Or.elim (eq_or_mem_of_mem_cons xal) (fun h : x = a => by rw [← h]; left; exact px)
fun h : x ∈ l => Or.inr ⟨x, h, px⟩
#align list.or_exists_of_exists_mem_cons List.or_exists_of_exists_mem_consₓ -- bExists change
theorem exists_mem_cons_iff (p : α → Prop) (a : α) (l : List α) :
(∃ x ∈ a :: l, p x) ↔ p a ∨ ∃ x ∈ l, p x :=
Iff.intro or_exists_of_exists_mem_cons fun h =>
Or.elim h (exists_mem_cons_of l) exists_mem_cons_of_exists
#align list.exists_mem_cons_iff List.exists_mem_cons_iff
instance : IsTrans (List α) Subset where
trans := fun _ _ _ => List.Subset.trans
#align list.subset_def List.subset_def
#align list.subset_append_of_subset_left List.subset_append_of_subset_left
#align list.subset_append_of_subset_right List.subset_append_of_subset_right
#align list.cons_subset List.cons_subset
theorem cons_subset_of_subset_of_mem {a : α} {l m : List α}
(ainm : a ∈ m) (lsubm : l ⊆ m) : a::l ⊆ m :=
cons_subset.2 ⟨ainm, lsubm⟩
#align list.cons_subset_of_subset_of_mem List.cons_subset_of_subset_of_mem
theorem append_subset_of_subset_of_subset {l₁ l₂ l : List α} (l₁subl : l₁ ⊆ l) (l₂subl : l₂ ⊆ l) :
l₁ ++ l₂ ⊆ l :=
fun _ h ↦ (mem_append.1 h).elim (@l₁subl _) (@l₂subl _)
#align list.append_subset_of_subset_of_subset List.append_subset_of_subset_of_subset
-- Porting note: in Batteries
#align list.append_subset_iff List.append_subset
alias ⟨eq_nil_of_subset_nil, _⟩ := subset_nil
#align list.eq_nil_of_subset_nil List.eq_nil_of_subset_nil
#align list.eq_nil_iff_forall_not_mem List.eq_nil_iff_forall_not_mem
#align list.map_subset List.map_subset
theorem map_subset_iff {l₁ l₂ : List α} (f : α → β) (h : Injective f) :
map f l₁ ⊆ map f l₂ ↔ l₁ ⊆ l₂ := by
refine ⟨?_, map_subset f⟩; intro h2 x hx
rcases mem_map.1 (h2 (mem_map_of_mem f hx)) with ⟨x', hx', hxx'⟩
cases h hxx'; exact hx'
#align list.map_subset_iff List.map_subset_iff
theorem append_eq_has_append {L₁ L₂ : List α} : List.append L₁ L₂ = L₁ ++ L₂ :=
rfl
#align list.append_eq_has_append List.append_eq_has_append
#align list.singleton_append List.singleton_append
#align list.append_ne_nil_of_ne_nil_left List.append_ne_nil_of_ne_nil_left
#align list.append_ne_nil_of_ne_nil_right List.append_ne_nil_of_ne_nil_right
#align list.append_eq_nil List.append_eq_nil
-- Porting note: in Batteries
#align list.nil_eq_append_iff List.nil_eq_append
@[deprecated (since := "2024-03-24")] alias append_eq_cons_iff := append_eq_cons
#align list.append_eq_cons_iff List.append_eq_cons
@[deprecated (since := "2024-03-24")] alias cons_eq_append_iff := cons_eq_append
#align list.cons_eq_append_iff List.cons_eq_append
#align list.append_eq_append_iff List.append_eq_append_iff
#align list.take_append_drop List.take_append_drop
#align list.append_inj List.append_inj
#align list.append_inj_right List.append_inj_rightₓ -- implicits order
#align list.append_inj_left List.append_inj_leftₓ -- implicits order
#align list.append_inj' List.append_inj'ₓ -- implicits order
#align list.append_inj_right' List.append_inj_right'ₓ -- implicits order
#align list.append_inj_left' List.append_inj_left'ₓ -- implicits order
@[deprecated (since := "2024-01-18")] alias append_left_cancel := append_cancel_left
#align list.append_left_cancel List.append_cancel_left
@[deprecated (since := "2024-01-18")] alias append_right_cancel := append_cancel_right
#align list.append_right_cancel List.append_cancel_right
@[simp] theorem append_left_eq_self {x y : List α} : x ++ y = y ↔ x = [] := by
rw [← append_left_inj (s₁ := x), nil_append]
@[simp] theorem self_eq_append_left {x y : List α} : y = x ++ y ↔ x = [] := by
rw [eq_comm, append_left_eq_self]
@[simp] theorem append_right_eq_self {x y : List α} : x ++ y = x ↔ y = [] := by
rw [← append_right_inj (t₁ := y), append_nil]
@[simp] theorem self_eq_append_right {x y : List α} : x = x ++ y ↔ y = [] := by
rw [eq_comm, append_right_eq_self]
theorem append_right_injective (s : List α) : Injective fun t ↦ s ++ t :=
fun _ _ ↦ append_cancel_left
#align list.append_right_injective List.append_right_injective
#align list.append_right_inj List.append_right_inj
theorem append_left_injective (t : List α) : Injective fun s ↦ s ++ t :=
fun _ _ ↦ append_cancel_right
#align list.append_left_injective List.append_left_injective
#align list.append_left_inj List.append_left_inj
#align list.map_eq_append_split List.map_eq_append_split
@[simp] lemma replicate_zero (a : α) : replicate 0 a = [] := rfl
#align list.replicate_zero List.replicate_zero
attribute [simp] replicate_succ
#align list.replicate_succ List.replicate_succ
lemma replicate_one (a : α) : replicate 1 a = [a] := rfl
#align list.replicate_one List.replicate_one
#align list.length_replicate List.length_replicate
#align list.mem_replicate List.mem_replicate
#align list.eq_of_mem_replicate List.eq_of_mem_replicate
theorem eq_replicate_length {a : α} : ∀ {l : List α}, l = replicate l.length a ↔ ∀ b ∈ l, b = a
| [] => by simp
| (b :: l) => by simp [eq_replicate_length]
#align list.eq_replicate_length List.eq_replicate_length
#align list.eq_replicate_of_mem List.eq_replicate_of_mem
#align list.eq_replicate List.eq_replicate
theorem replicate_add (m n) (a : α) : replicate (m + n) a = replicate m a ++ replicate n a := by
induction m <;> simp [*, succ_add, replicate]
#align list.replicate_add List.replicate_add
theorem replicate_succ' (n) (a : α) : replicate (n + 1) a = replicate n a ++ [a] :=
replicate_add n 1 a
#align list.replicate_succ' List.replicate_succ'
theorem replicate_subset_singleton (n) (a : α) : replicate n a ⊆ [a] := fun _ h =>
mem_singleton.2 (eq_of_mem_replicate h)
#align list.replicate_subset_singleton List.replicate_subset_singleton
theorem subset_singleton_iff {a : α} {L : List α} : L ⊆ [a] ↔ ∃ n, L = replicate n a := by
simp only [eq_replicate, subset_def, mem_singleton, exists_eq_left']
#align list.subset_singleton_iff List.subset_singleton_iff
@[simp] theorem map_replicate (f : α → β) (n) (a : α) :
map f (replicate n a) = replicate n (f a) := by
induction n <;> [rfl; simp only [*, replicate, map]]
#align list.map_replicate List.map_replicate
@[simp] theorem tail_replicate (a : α) (n) :
tail (replicate n a) = replicate (n - 1) a := by cases n <;> rfl
#align list.tail_replicate List.tail_replicate
@[simp] theorem join_replicate_nil (n : ℕ) : join (replicate n []) = @nil α := by
induction n <;> [rfl; simp only [*, replicate, join, append_nil]]
#align list.join_replicate_nil List.join_replicate_nil
theorem replicate_right_injective {n : ℕ} (hn : n ≠ 0) : Injective (@replicate α n) :=
fun _ _ h => (eq_replicate.1 h).2 _ <| mem_replicate.2 ⟨hn, rfl⟩
#align list.replicate_right_injective List.replicate_right_injective
theorem replicate_right_inj {a b : α} {n : ℕ} (hn : n ≠ 0) :
replicate n a = replicate n b ↔ a = b :=
(replicate_right_injective hn).eq_iff
#align list.replicate_right_inj List.replicate_right_inj
@[simp] theorem replicate_right_inj' {a b : α} : ∀ {n},
replicate n a = replicate n b ↔ n = 0 ∨ a = b
| 0 => by simp
| n + 1 => (replicate_right_inj n.succ_ne_zero).trans <| by simp only [n.succ_ne_zero, false_or]
#align list.replicate_right_inj' List.replicate_right_inj'
theorem replicate_left_injective (a : α) : Injective (replicate · a) :=
LeftInverse.injective (length_replicate · a)
#align list.replicate_left_injective List.replicate_left_injective
@[simp] theorem replicate_left_inj {a : α} {n m : ℕ} : replicate n a = replicate m a ↔ n = m :=
(replicate_left_injective a).eq_iff
#align list.replicate_left_inj List.replicate_left_inj
@[simp] theorem head_replicate (n : ℕ) (a : α) (h) : head (replicate n a) h = a := by
cases n <;> simp at h ⊢
theorem mem_pure (x y : α) : x ∈ (pure y : List α) ↔ x = y := by simp
#align list.mem_pure List.mem_pure
@[simp]
theorem bind_eq_bind {α β} (f : α → List β) (l : List α) : l >>= f = l.bind f :=
rfl
#align list.bind_eq_bind List.bind_eq_bind
#align list.bind_append List.append_bind
#align list.concat_nil List.concat_nil
#align list.concat_cons List.concat_cons
#align list.concat_eq_append List.concat_eq_append
#align list.init_eq_of_concat_eq List.init_eq_of_concat_eq
#align list.last_eq_of_concat_eq List.last_eq_of_concat_eq
#align list.concat_ne_nil List.concat_ne_nil
#align list.concat_append List.concat_append
#align list.length_concat List.length_concat
#align list.append_concat List.append_concat
#align list.reverse_nil List.reverse_nil
#align list.reverse_core List.reverseAux
-- Porting note: Do we need this?
attribute [local simp] reverseAux
#align list.reverse_cons List.reverse_cons
#align list.reverse_core_eq List.reverseAux_eq
theorem reverse_cons' (a : α) (l : List α) : reverse (a :: l) = concat (reverse l) a := by
simp only [reverse_cons, concat_eq_append]
#align list.reverse_cons' List.reverse_cons'
theorem reverse_concat' (l : List α) (a : α) : (l ++ [a]).reverse = a :: l.reverse := by
rw [reverse_append]; rfl
-- Porting note (#10618): simp can prove this
-- @[simp]
theorem reverse_singleton (a : α) : reverse [a] = [a] :=
rfl
#align list.reverse_singleton List.reverse_singleton
#align list.reverse_append List.reverse_append
#align list.reverse_concat List.reverse_concat
#align list.reverse_reverse List.reverse_reverse
@[simp]
theorem reverse_involutive : Involutive (@reverse α) :=
reverse_reverse
#align list.reverse_involutive List.reverse_involutive
@[simp]
theorem reverse_injective : Injective (@reverse α) :=
reverse_involutive.injective
#align list.reverse_injective List.reverse_injective
theorem reverse_surjective : Surjective (@reverse α) :=
reverse_involutive.surjective
#align list.reverse_surjective List.reverse_surjective
theorem reverse_bijective : Bijective (@reverse α) :=
reverse_involutive.bijective
#align list.reverse_bijective List.reverse_bijective
@[simp]
theorem reverse_inj {l₁ l₂ : List α} : reverse l₁ = reverse l₂ ↔ l₁ = l₂ :=
reverse_injective.eq_iff
#align list.reverse_inj List.reverse_inj
theorem reverse_eq_iff {l l' : List α} : l.reverse = l' ↔ l = l'.reverse :=
reverse_involutive.eq_iff
#align list.reverse_eq_iff List.reverse_eq_iff
#align list.reverse_eq_nil List.reverse_eq_nil_iff
theorem concat_eq_reverse_cons (a : α) (l : List α) : concat l a = reverse (a :: reverse l) := by
simp only [concat_eq_append, reverse_cons, reverse_reverse]
#align list.concat_eq_reverse_cons List.concat_eq_reverse_cons
#align list.length_reverse List.length_reverse
-- Porting note: This one was @[simp] in mathlib 3,
-- but Lean contains a competing simp lemma reverse_map.
-- For now we remove @[simp] to avoid simplification loops.
-- TODO: Change Lean lemma to match mathlib 3?
theorem map_reverse (f : α → β) (l : List α) : map f (reverse l) = reverse (map f l) :=
(reverse_map f l).symm
#align list.map_reverse List.map_reverse
theorem map_reverseAux (f : α → β) (l₁ l₂ : List α) :
map f (reverseAux l₁ l₂) = reverseAux (map f l₁) (map f l₂) := by
simp only [reverseAux_eq, map_append, map_reverse]
#align list.map_reverse_core List.map_reverseAux
#align list.mem_reverse List.mem_reverse
@[simp] theorem reverse_replicate (n) (a : α) : reverse (replicate n a) = replicate n a :=
eq_replicate.2
⟨by rw [length_reverse, length_replicate],
fun b h => eq_of_mem_replicate (mem_reverse.1 h)⟩
#align list.reverse_replicate List.reverse_replicate
-- Porting note: this does not work as desired
-- attribute [simp] List.isEmpty
theorem isEmpty_iff_eq_nil {l : List α} : l.isEmpty ↔ l = [] := by cases l <;> simp [isEmpty]
#align list.empty_iff_eq_nil List.isEmpty_iff_eq_nil
#align list.length_init List.length_dropLast
@[simp]
theorem getLast_cons {a : α} {l : List α} :
∀ h : l ≠ nil, getLast (a :: l) (cons_ne_nil a l) = getLast l h := by
induction l <;> intros
· contradiction
· rfl
#align list.last_cons List.getLast_cons
theorem getLast_append_singleton {a : α} (l : List α) :
getLast (l ++ [a]) (append_ne_nil_of_ne_nil_right l _ (cons_ne_nil a _)) = a := by
simp only [getLast_append]
#align list.last_append_singleton List.getLast_append_singleton
-- Porting note: name should be fixed upstream
theorem getLast_append' (l₁ l₂ : List α) (h : l₂ ≠ []) :
getLast (l₁ ++ l₂) (append_ne_nil_of_ne_nil_right l₁ l₂ h) = getLast l₂ h := by
induction' l₁ with _ _ ih
· simp
· simp only [cons_append]
rw [List.getLast_cons]
exact ih
#align list.last_append List.getLast_append'
theorem getLast_concat' {a : α} (l : List α) : getLast (concat l a) (concat_ne_nil a l) = a :=
getLast_concat ..
#align list.last_concat List.getLast_concat'
@[simp]
theorem getLast_singleton' (a : α) : getLast [a] (cons_ne_nil a []) = a := rfl
#align list.last_singleton List.getLast_singleton'
-- Porting note (#10618): simp can prove this
-- @[simp]
theorem getLast_cons_cons (a₁ a₂ : α) (l : List α) :
getLast (a₁ :: a₂ :: l) (cons_ne_nil _ _) = getLast (a₂ :: l) (cons_ne_nil a₂ l) :=
rfl
#align list.last_cons_cons List.getLast_cons_cons
theorem dropLast_append_getLast : ∀ {l : List α} (h : l ≠ []), dropLast l ++ [getLast l h] = l
| [], h => absurd rfl h
| [a], h => rfl
| a :: b :: l, h => by
rw [dropLast_cons₂, cons_append, getLast_cons (cons_ne_nil _ _)]
congr
exact dropLast_append_getLast (cons_ne_nil b l)
#align list.init_append_last List.dropLast_append_getLast
theorem getLast_congr {l₁ l₂ : List α} (h₁ : l₁ ≠ []) (h₂ : l₂ ≠ []) (h₃ : l₁ = l₂) :
getLast l₁ h₁ = getLast l₂ h₂ := by subst l₁; rfl
#align list.last_congr List.getLast_congr
#align list.last_mem List.getLast_mem
theorem getLast_replicate_succ (m : ℕ) (a : α) :
(replicate (m + 1) a).getLast (ne_nil_of_length_eq_succ (length_replicate _ _)) = a := by
simp only [replicate_succ']
exact getLast_append_singleton _
#align list.last_replicate_succ List.getLast_replicate_succ
-- Porting note: Moved earlier in file, for use in subsequent lemmas.
@[simp]
theorem getLast?_cons_cons (a b : α) (l : List α) :
getLast? (a :: b :: l) = getLast? (b :: l) := rfl
@[simp]
theorem getLast?_isNone : ∀ {l : List α}, (getLast? l).isNone ↔ l = []
| [] => by simp
| [a] => by simp
| a :: b :: l => by simp [@getLast?_isNone (b :: l)]
#align list.last'_is_none List.getLast?_isNone
@[simp]
theorem getLast?_isSome : ∀ {l : List α}, l.getLast?.isSome ↔ l ≠ []
| [] => by simp
| [a] => by simp
| a :: b :: l => by simp [@getLast?_isSome (b :: l)]
#align list.last'_is_some List.getLast?_isSome
theorem mem_getLast?_eq_getLast : ∀ {l : List α} {x : α}, x ∈ l.getLast? → ∃ h, x = getLast l h
| [], x, hx => False.elim <| by simp at hx
| [a], x, hx =>
have : a = x := by simpa using hx
this ▸ ⟨cons_ne_nil a [], rfl⟩
| a :: b :: l, x, hx => by
rw [getLast?_cons_cons] at hx
rcases mem_getLast?_eq_getLast hx with ⟨_, h₂⟩
use cons_ne_nil _ _
assumption
#align list.mem_last'_eq_last List.mem_getLast?_eq_getLast
theorem getLast?_eq_getLast_of_ne_nil : ∀ {l : List α} (h : l ≠ []), l.getLast? = some (l.getLast h)
| [], h => (h rfl).elim
| [_], _ => rfl
| _ :: b :: l, _ => @getLast?_eq_getLast_of_ne_nil (b :: l) (cons_ne_nil _ _)
#align list.last'_eq_last_of_ne_nil List.getLast?_eq_getLast_of_ne_nil
theorem mem_getLast?_cons {x y : α} : ∀ {l : List α}, x ∈ l.getLast? → x ∈ (y :: l).getLast?
| [], _ => by contradiction
| _ :: _, h => h
#align list.mem_last'_cons List.mem_getLast?_cons
theorem mem_of_mem_getLast? {l : List α} {a : α} (ha : a ∈ l.getLast?) : a ∈ l :=
let ⟨_, h₂⟩ := mem_getLast?_eq_getLast ha
h₂.symm ▸ getLast_mem _
#align list.mem_of_mem_last' List.mem_of_mem_getLast?
theorem dropLast_append_getLast? : ∀ {l : List α}, ∀ a ∈ l.getLast?, dropLast l ++ [a] = l
| [], a, ha => (Option.not_mem_none a ha).elim
| [a], _, rfl => rfl
| a :: b :: l, c, hc => by
rw [getLast?_cons_cons] at hc
rw [dropLast_cons₂, cons_append, dropLast_append_getLast? _ hc]
#align list.init_append_last' List.dropLast_append_getLast?
theorem getLastI_eq_getLast? [Inhabited α] : ∀ l : List α, l.getLastI = l.getLast?.iget
| [] => by simp [getLastI, Inhabited.default]
| [a] => rfl
| [a, b] => rfl
| [a, b, c] => rfl
| _ :: _ :: c :: l => by simp [getLastI, getLastI_eq_getLast? (c :: l)]
#align list.ilast_eq_last' List.getLastI_eq_getLast?
@[simp]
theorem getLast?_append_cons :
∀ (l₁ : List α) (a : α) (l₂ : List α), getLast? (l₁ ++ a :: l₂) = getLast? (a :: l₂)
| [], a, l₂ => rfl
| [b], a, l₂ => rfl
| b :: c :: l₁, a, l₂ => by rw [cons_append, cons_append, getLast?_cons_cons,
← cons_append, getLast?_append_cons (c :: l₁)]
#align list.last'_append_cons List.getLast?_append_cons
#align list.last'_cons_cons List.getLast?_cons_cons
theorem getLast?_append_of_ne_nil (l₁ : List α) :
∀ {l₂ : List α} (_ : l₂ ≠ []), getLast? (l₁ ++ l₂) = getLast? l₂
| [], hl₂ => by contradiction
| b :: l₂, _ => getLast?_append_cons l₁ b l₂
#align list.last'_append_of_ne_nil List.getLast?_append_of_ne_nil
theorem getLast?_append {l₁ l₂ : List α} {x : α} (h : x ∈ l₂.getLast?) :
x ∈ (l₁ ++ l₂).getLast? := by
cases l₂
· contradiction
· rw [List.getLast?_append_cons]
exact h
#align list.last'_append List.getLast?_append
@[simp]
theorem head!_nil [Inhabited α] : ([] : List α).head! = default := rfl
@[simp] theorem head_cons_tail (x : List α) (h : x ≠ []) : x.head h :: x.tail = x := by
cases x <;> simp at h ⊢
theorem head!_eq_head? [Inhabited α] (l : List α) : head! l = (head? l).iget := by cases l <;> rfl
#align list.head_eq_head' List.head!_eq_head?
theorem surjective_head! [Inhabited α] : Surjective (@head! α _) := fun x => ⟨[x], rfl⟩
#align list.surjective_head List.surjective_head!
theorem surjective_head? : Surjective (@head? α) :=
Option.forall.2 ⟨⟨[], rfl⟩, fun x => ⟨[x], rfl⟩⟩
#align list.surjective_head' List.surjective_head?
theorem surjective_tail : Surjective (@tail α)
| [] => ⟨[], rfl⟩
| a :: l => ⟨a :: a :: l, rfl⟩
#align list.surjective_tail List.surjective_tail
theorem eq_cons_of_mem_head? {x : α} : ∀ {l : List α}, x ∈ l.head? → l = x :: tail l
| [], h => (Option.not_mem_none _ h).elim
| a :: l, h => by
simp only [head?, Option.mem_def, Option.some_inj] at h
exact h ▸ rfl
#align list.eq_cons_of_mem_head' List.eq_cons_of_mem_head?
theorem mem_of_mem_head? {x : α} {l : List α} (h : x ∈ l.head?) : x ∈ l :=
(eq_cons_of_mem_head? h).symm ▸ mem_cons_self _ _
#align list.mem_of_mem_head' List.mem_of_mem_head?
@[simp] theorem head!_cons [Inhabited α] (a : α) (l : List α) : head! (a :: l) = a := rfl
#align list.head_cons List.head!_cons
#align list.tail_nil List.tail_nil
#align list.tail_cons List.tail_cons
@[simp]
theorem head!_append [Inhabited α] (t : List α) {s : List α} (h : s ≠ []) :
head! (s ++ t) = head! s := by
induction s
· contradiction
· rfl
#align list.head_append List.head!_append
theorem head?_append {s t : List α} {x : α} (h : x ∈ s.head?) : x ∈ (s ++ t).head? := by
cases s
· contradiction
· exact h
#align list.head'_append List.head?_append
theorem head?_append_of_ne_nil :
∀ (l₁ : List α) {l₂ : List α} (_ : l₁ ≠ []), head? (l₁ ++ l₂) = head? l₁
| _ :: _, _, _ => rfl
#align list.head'_append_of_ne_nil List.head?_append_of_ne_nil
theorem tail_append_singleton_of_ne_nil {a : α} {l : List α} (h : l ≠ nil) :
tail (l ++ [a]) = tail l ++ [a] := by
induction l
· contradiction
· rw [tail, cons_append, tail]
#align list.tail_append_singleton_of_ne_nil List.tail_append_singleton_of_ne_nil
theorem cons_head?_tail : ∀ {l : List α} {a : α}, a ∈ head? l → a :: tail l = l
| [], a, h => by contradiction
| b :: l, a, h => by
simp? at h says simp only [head?_cons, Option.mem_def, Option.some.injEq] at h
simp [h]
#align list.cons_head'_tail List.cons_head?_tail
theorem head!_mem_head? [Inhabited α] : ∀ {l : List α}, l ≠ [] → head! l ∈ head? l
| [], h => by contradiction
| a :: l, _ => rfl
#align list.head_mem_head' List.head!_mem_head?
theorem cons_head!_tail [Inhabited α] {l : List α} (h : l ≠ []) : head! l :: tail l = l :=
cons_head?_tail (head!_mem_head? h)
#align list.cons_head_tail List.cons_head!_tail
theorem head!_mem_self [Inhabited α] {l : List α} (h : l ≠ nil) : l.head! ∈ l := by
have h' := mem_cons_self l.head! l.tail
rwa [cons_head!_tail h] at h'
#align list.head_mem_self List.head!_mem_self
theorem head_mem {l : List α} : ∀ (h : l ≠ nil), l.head h ∈ l := by
cases l <;> simp
@[simp]
theorem head?_map (f : α → β) (l) : head? (map f l) = (head? l).map f := by cases l <;> rfl
#align list.head'_map List.head?_map
theorem tail_append_of_ne_nil (l l' : List α) (h : l ≠ []) : (l ++ l').tail = l.tail ++ l' := by
cases l
· contradiction
· simp
#align list.tail_append_of_ne_nil List.tail_append_of_ne_nil
#align list.nth_le_eq_iff List.get_eq_iff
theorem get_eq_get? (l : List α) (i : Fin l.length) :
l.get i = (l.get? i).get (by simp [get?_eq_get]) := by
simp [get_eq_iff]
#align list.some_nth_le_eq List.get?_eq_get
-- Porting note: List.modifyHead has @[simp], and Lean 4 treats this as
-- an invitation to unfold modifyHead in any context,
-- not just use the equational lemmas.
-- @[simp]
@[simp 1100, nolint simpNF]
theorem modifyHead_modifyHead (l : List α) (f g : α → α) :
(l.modifyHead f).modifyHead g = l.modifyHead (g ∘ f) := by cases l <;> simp
#align list.modify_head_modify_head List.modifyHead_modifyHead
@[elab_as_elim]
def reverseRecOn {motive : List α → Sort*} (l : List α) (nil : motive [])
(append_singleton : ∀ (l : List α) (a : α), motive l → motive (l ++ [a])) : motive l :=
match h : reverse l with
| [] => cast (congr_arg motive <| by simpa using congr(reverse $h.symm)) <|
nil
| head :: tail =>
cast (congr_arg motive <| by simpa using congr(reverse $h.symm)) <|
append_singleton _ head <| reverseRecOn (reverse tail) nil append_singleton
termination_by l.length
decreasing_by
simp_wf
rw [← length_reverse l, h, length_cons]
simp [Nat.lt_succ]
#align list.reverse_rec_on List.reverseRecOn
@[simp]
theorem reverseRecOn_nil {motive : List α → Sort*} (nil : motive [])
(append_singleton : ∀ (l : List α) (a : α), motive l → motive (l ++ [a])) :
reverseRecOn [] nil append_singleton = nil := reverseRecOn.eq_1 ..
-- `unusedHavesSuffices` is getting confused by the unfolding of `reverseRecOn`
@[simp, nolint unusedHavesSuffices]
| Mathlib/Data/List/Basic.lean | 944 | 962 | theorem reverseRecOn_concat {motive : List α → Sort*} (x : α) (xs : List α) (nil : motive [])
(append_singleton : ∀ (l : List α) (a : α), motive l → motive (l ++ [a])) :
reverseRecOn (motive := motive) (xs ++ [x]) nil append_singleton =
append_singleton _ _ (reverseRecOn (motive := motive) xs nil append_singleton) := by |
suffices ∀ ys (h : reverse (reverse xs) = ys),
reverseRecOn (motive := motive) (xs ++ [x]) nil append_singleton =
cast (by simp [(reverse_reverse _).symm.trans h])
(append_singleton _ x (reverseRecOn (motive := motive) ys nil append_singleton)) by
exact this _ (reverse_reverse xs)
intros ys hy
conv_lhs => unfold reverseRecOn
split
next h => simp at h
next heq =>
revert heq
simp only [reverse_append, reverse_cons, reverse_nil, nil_append, singleton_append, cons.injEq]
rintro ⟨rfl, rfl⟩
subst ys
rfl
|
import Mathlib.Order.Filter.Lift
import Mathlib.Topology.Separation
import Mathlib.Order.Interval.Set.Monotone
#align_import topology.filter from "leanprover-community/mathlib"@"4c19a16e4b705bf135cf9a80ac18fcc99c438514"
open Set Filter TopologicalSpace
open Filter Topology
variable {ι : Sort*} {α β X Y : Type*}
namespace Filter
instance : TopologicalSpace (Filter α) :=
generateFrom <| range <| Iic ∘ 𝓟
theorem isOpen_Iic_principal {s : Set α} : IsOpen (Iic (𝓟 s)) :=
GenerateOpen.basic _ (mem_range_self _)
#align filter.is_open_Iic_principal Filter.isOpen_Iic_principal
| Mathlib/Topology/Filter.lean | 55 | 56 | theorem isOpen_setOf_mem {s : Set α} : IsOpen { l : Filter α | s ∈ l } := by |
simpa only [Iic_principal] using isOpen_Iic_principal
|
import Mathlib.Analysis.Calculus.ContDiff.RCLike
import Mathlib.MeasureTheory.Measure.Hausdorff
#align_import topology.metric_space.hausdorff_dimension from "leanprover-community/mathlib"@"8f9fea08977f7e450770933ee6abb20733b47c92"
open scoped MeasureTheory ENNReal NNReal Topology
open MeasureTheory MeasureTheory.Measure Set TopologicalSpace FiniteDimensional Filter
variable {ι X Y : Type*} [EMetricSpace X] [EMetricSpace Y]
@[irreducible] noncomputable def dimH (s : Set X) : ℝ≥0∞ := by
borelize X; exact ⨆ (d : ℝ≥0) (_ : @hausdorffMeasure X _ _ ⟨rfl⟩ d s = ∞), d
set_option linter.uppercaseLean3 false in
#align dimH dimH
section Measurable
variable [MeasurableSpace X] [BorelSpace X]
theorem dimH_def (s : Set X) : dimH s = ⨆ (d : ℝ≥0) (_ : μH[d] s = ∞), (d : ℝ≥0∞) := by
borelize X; rw [dimH]
set_option linter.uppercaseLean3 false in
#align dimH_def dimH_def
theorem hausdorffMeasure_of_lt_dimH {s : Set X} {d : ℝ≥0} (h : ↑d < dimH s) : μH[d] s = ∞ := by
simp only [dimH_def, lt_iSup_iff] at h
rcases h with ⟨d', hsd', hdd'⟩
rw [ENNReal.coe_lt_coe, ← NNReal.coe_lt_coe] at hdd'
exact top_unique (hsd' ▸ hausdorffMeasure_mono hdd'.le _)
set_option linter.uppercaseLean3 false in
#align hausdorff_measure_of_lt_dimH hausdorffMeasure_of_lt_dimH
theorem dimH_le {s : Set X} {d : ℝ≥0∞} (H : ∀ d' : ℝ≥0, μH[d'] s = ∞ → ↑d' ≤ d) : dimH s ≤ d :=
(dimH_def s).trans_le <| iSup₂_le H
set_option linter.uppercaseLean3 false in
#align dimH_le dimH_le
theorem dimH_le_of_hausdorffMeasure_ne_top {s : Set X} {d : ℝ≥0} (h : μH[d] s ≠ ∞) : dimH s ≤ d :=
le_of_not_lt <| mt hausdorffMeasure_of_lt_dimH h
set_option linter.uppercaseLean3 false in
#align dimH_le_of_hausdorff_measure_ne_top dimH_le_of_hausdorffMeasure_ne_top
| Mathlib/Topology/MetricSpace/HausdorffDimension.lean | 133 | 135 | theorem le_dimH_of_hausdorffMeasure_eq_top {s : Set X} {d : ℝ≥0} (h : μH[d] s = ∞) :
↑d ≤ dimH s := by |
rw [dimH_def]; exact le_iSup₂ (α := ℝ≥0∞) d h
|
import Mathlib.CategoryTheory.Category.Grpd
import Mathlib.CategoryTheory.Groupoid
import Mathlib.Topology.Category.TopCat.Basic
import Mathlib.Topology.Homotopy.Path
import Mathlib.Data.Set.Subsingleton
#align_import algebraic_topology.fundamental_groupoid.basic from "leanprover-community/mathlib"@"3d7987cda72abc473c7cdbbb075170e9ac620042"
open CategoryTheory
universe u v
variable {X : Type u} {Y : Type v} [TopologicalSpace X] [TopologicalSpace Y]
variable {x₀ x₁ : X}
noncomputable section
open unitInterval
namespace Path
namespace Homotopy
section
def reflTransSymmAux (x : I × I) : ℝ :=
if (x.2 : ℝ) ≤ 1 / 2 then x.1 * 2 * x.2 else x.1 * (2 - 2 * x.2)
#align path.homotopy.refl_trans_symm_aux Path.Homotopy.reflTransSymmAux
@[continuity]
theorem continuous_reflTransSymmAux : Continuous reflTransSymmAux := by
refine continuous_if_le ?_ ?_ (Continuous.continuousOn ?_) (Continuous.continuousOn ?_) ?_
· continuity
· continuity
· continuity
· continuity
intro x hx
norm_num [hx, mul_assoc]
#align path.homotopy.continuous_refl_trans_symm_aux Path.Homotopy.continuous_reflTransSymmAux
theorem reflTransSymmAux_mem_I (x : I × I) : reflTransSymmAux x ∈ I := by
dsimp only [reflTransSymmAux]
split_ifs
· constructor
· apply mul_nonneg
· apply mul_nonneg
· unit_interval
· norm_num
· unit_interval
· rw [mul_assoc]
apply mul_le_one
· unit_interval
· apply mul_nonneg
· norm_num
· unit_interval
· linarith
· constructor
· apply mul_nonneg
· unit_interval
linarith [unitInterval.nonneg x.2, unitInterval.le_one x.2]
· apply mul_le_one
· unit_interval
· linarith [unitInterval.nonneg x.2, unitInterval.le_one x.2]
· linarith [unitInterval.nonneg x.2, unitInterval.le_one x.2]
set_option linter.uppercaseLean3 false in
#align path.homotopy.refl_trans_symm_aux_mem_I Path.Homotopy.reflTransSymmAux_mem_I
def reflTransSymm (p : Path x₀ x₁) : Homotopy (Path.refl x₀) (p.trans p.symm) where
toFun x := p ⟨reflTransSymmAux x, reflTransSymmAux_mem_I x⟩
continuous_toFun := by continuity
map_zero_left := by simp [reflTransSymmAux]
map_one_left x := by
dsimp only [reflTransSymmAux, Path.coe_toContinuousMap, Path.trans]
change _ = ite _ _ _
split_ifs with h
· rw [Path.extend, Set.IccExtend_of_mem]
· norm_num
· rw [unitInterval.mul_pos_mem_iff zero_lt_two]
exact ⟨unitInterval.nonneg x, h⟩
· rw [Path.symm, Path.extend, Set.IccExtend_of_mem]
· simp only [Set.Icc.coe_one, one_mul, coe_mk_mk, Function.comp_apply]
congr 1
ext
norm_num [sub_sub_eq_add_sub]
· rw [unitInterval.two_mul_sub_one_mem_iff]
exact ⟨(not_le.1 h).le, unitInterval.le_one x⟩
prop' t x hx := by
simp only [Set.mem_singleton_iff, Set.mem_insert_iff] at hx
simp only [ContinuousMap.coe_mk, coe_toContinuousMap, Path.refl_apply]
cases hx with
| inl hx
| inr hx =>
set_option tactic.skipAssignedInstances false in
rw [hx]
norm_num [reflTransSymmAux]
#align path.homotopy.refl_trans_symm Path.Homotopy.reflTransSymm
def reflSymmTrans (p : Path x₀ x₁) : Homotopy (Path.refl x₁) (p.symm.trans p) :=
(reflTransSymm p.symm).cast rfl <| congr_arg _ (Path.symm_symm _)
#align path.homotopy.refl_symm_trans Path.Homotopy.reflSymmTrans
end
section Assoc
def transAssocReparamAux (t : I) : ℝ :=
if (t : ℝ) ≤ 1 / 4 then 2 * t else if (t : ℝ) ≤ 1 / 2 then t + 1 / 4 else 1 / 2 * (t + 1)
#align path.homotopy.trans_assoc_reparam_aux Path.Homotopy.transAssocReparamAux
@[continuity]
theorem continuous_transAssocReparamAux : Continuous transAssocReparamAux := by
refine continuous_if_le ?_ ?_ (Continuous.continuousOn ?_)
(continuous_if_le ?_ ?_
(Continuous.continuousOn ?_) (Continuous.continuousOn ?_) ?_).continuousOn
?_ <;>
[continuity; continuity; continuity; continuity; continuity; continuity; continuity; skip;
skip] <;>
· intro x hx
set_option tactic.skipAssignedInstances false in norm_num [hx]
#align path.homotopy.continuous_trans_assoc_reparam_aux Path.Homotopy.continuous_transAssocReparamAux
theorem transAssocReparamAux_mem_I (t : I) : transAssocReparamAux t ∈ I := by
unfold transAssocReparamAux
split_ifs <;> constructor <;> linarith [unitInterval.le_one t, unitInterval.nonneg t]
set_option linter.uppercaseLean3 false in
#align path.homotopy.trans_assoc_reparam_aux_mem_I Path.Homotopy.transAssocReparamAux_mem_I
theorem transAssocReparamAux_zero : transAssocReparamAux 0 = 0 := by
set_option tactic.skipAssignedInstances false in norm_num [transAssocReparamAux]
#align path.homotopy.trans_assoc_reparam_aux_zero Path.Homotopy.transAssocReparamAux_zero
| Mathlib/AlgebraicTopology/FundamentalGroupoid/Basic.lean | 210 | 211 | theorem transAssocReparamAux_one : transAssocReparamAux 1 = 1 := by |
set_option tactic.skipAssignedInstances false in norm_num [transAssocReparamAux]
|
import Mathlib.CategoryTheory.EqToHom
import Mathlib.CategoryTheory.Quotient
import Mathlib.Combinatorics.Quiver.Path
#align_import category_theory.path_category from "leanprover-community/mathlib"@"c6dd521ebdce53bb372c527569dd7c25de53a08b"
universe v₁ v₂ u₁ u₂
namespace CategoryTheory
section
def Paths (V : Type u₁) : Type u₁ := V
#align category_theory.paths CategoryTheory.Paths
instance (V : Type u₁) [Inhabited V] : Inhabited (Paths V) := ⟨(default : V)⟩
variable (V : Type u₁) [Quiver.{v₁ + 1} V]
namespace Paths
instance categoryPaths : Category.{max u₁ v₁} (Paths V) where
Hom := fun X Y : V => Quiver.Path X Y
id X := Quiver.Path.nil
comp f g := Quiver.Path.comp f g
#align category_theory.paths.category_paths CategoryTheory.Paths.categoryPaths
variable {V}
@[simps]
def of : V ⥤q Paths V where
obj X := X
map f := f.toPath
#align category_theory.paths.of CategoryTheory.Paths.of
attribute [local ext] Functor.ext
def lift {C} [Category C] (φ : V ⥤q C) : Paths V ⥤ C where
obj := φ.obj
map {X} {Y} f :=
@Quiver.Path.rec V _ X (fun Y _ => φ.obj X ⟶ φ.obj Y) (𝟙 <| φ.obj X)
(fun _ f ihp => ihp ≫ φ.map f) Y f
map_id X := rfl
map_comp f g := by
induction' g with _ _ g' p ih _ _ _
· rw [Category.comp_id]
rfl
· have : f ≫ Quiver.Path.cons g' p = (f ≫ g').cons p := by apply Quiver.Path.comp_cons
rw [this]
simp only at ih ⊢
rw [ih, Category.assoc]
#align category_theory.paths.lift CategoryTheory.Paths.lift
@[simp]
theorem lift_nil {C} [Category C] (φ : V ⥤q C) (X : V) :
(lift φ).map Quiver.Path.nil = 𝟙 (φ.obj X) := rfl
#align category_theory.paths.lift_nil CategoryTheory.Paths.lift_nil
@[simp]
theorem lift_cons {C} [Category C] (φ : V ⥤q C) {X Y Z : V} (p : Quiver.Path X Y) (f : Y ⟶ Z) :
(lift φ).map (p.cons f) = (lift φ).map p ≫ φ.map f := rfl
#align category_theory.paths.lift_cons CategoryTheory.Paths.lift_cons
@[simp]
theorem lift_toPath {C} [Category C] (φ : V ⥤q C) {X Y : V} (f : X ⟶ Y) :
(lift φ).map f.toPath = φ.map f := by
dsimp [Quiver.Hom.toPath, lift]
simp
#align category_theory.paths.lift_to_path CategoryTheory.Paths.lift_toPath
theorem lift_spec {C} [Category C] (φ : V ⥤q C) : of ⋙q (lift φ).toPrefunctor = φ := by
fapply Prefunctor.ext
· rintro X
rfl
· rintro X Y f
rcases φ with ⟨φo, φm⟩
dsimp [lift, Quiver.Hom.toPath]
simp only [Category.id_comp]
#align category_theory.paths.lift_spec CategoryTheory.Paths.lift_spec
| Mathlib/CategoryTheory/PathCategory.lean | 103 | 119 | theorem lift_unique {C} [Category C] (φ : V ⥤q C) (Φ : Paths V ⥤ C)
(hΦ : of ⋙q Φ.toPrefunctor = φ) : Φ = lift φ := by |
subst_vars
fapply Functor.ext
· rintro X
rfl
· rintro X Y f
dsimp [lift]
induction' f with _ _ p f' ih
· simp only [Category.comp_id]
apply Functor.map_id
· simp only [Category.comp_id, Category.id_comp] at ih ⊢
-- Porting note: Had to do substitute `p.cons f'` and `f'.toPath` by their fully qualified
-- versions in this `have` clause (elsewhere too).
have : Φ.map (Quiver.Path.cons p f') = Φ.map p ≫ Φ.map (Quiver.Hom.toPath f') := by
convert Functor.map_comp Φ p (Quiver.Hom.toPath f')
rw [this, ih]
|
import Mathlib.Algebra.Polynomial.AlgebraMap
import Mathlib.Algebra.Polynomial.Basic
import Mathlib.RingTheory.Ideal.Maps
import Mathlib.RingTheory.MvPowerSeries.Basic
#align_import ring_theory.power_series.basic from "leanprover-community/mathlib"@"2d5739b61641ee4e7e53eca5688a08f66f2e6a60"
noncomputable section
open Finset (antidiagonal mem_antidiagonal)
def PowerSeries (R : Type*) :=
MvPowerSeries Unit R
#align power_series PowerSeries
namespace PowerSeries
open Finsupp (single)
variable {R : Type*}
section
-- Porting note: not available in Lean 4
-- local reducible PowerSeries
scoped notation:9000 R "⟦X⟧" => PowerSeries R
instance [Inhabited R] : Inhabited R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [Zero R] : Zero R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [AddMonoid R] : AddMonoid R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [AddGroup R] : AddGroup R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [AddCommMonoid R] : AddCommMonoid R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [AddCommGroup R] : AddCommGroup R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [Semiring R] : Semiring R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [CommSemiring R] : CommSemiring R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [Ring R] : Ring R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [CommRing R] : CommRing R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance [Nontrivial R] : Nontrivial R⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance {A} [Semiring R] [AddCommMonoid A] [Module R A] : Module R A⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
instance {A S} [Semiring R] [Semiring S] [AddCommMonoid A] [Module R A] [Module S A] [SMul R S]
[IsScalarTower R S A] : IsScalarTower R S A⟦X⟧ :=
Pi.isScalarTower
instance {A} [Semiring A] [CommSemiring R] [Algebra R A] : Algebra R A⟦X⟧ := by
dsimp only [PowerSeries]
infer_instance
end
section Semiring
variable (R) [Semiring R]
def coeff (n : ℕ) : R⟦X⟧ →ₗ[R] R :=
MvPowerSeries.coeff R (single () n)
#align power_series.coeff PowerSeries.coeff
def monomial (n : ℕ) : R →ₗ[R] R⟦X⟧ :=
MvPowerSeries.monomial R (single () n)
#align power_series.monomial PowerSeries.monomial
variable {R}
theorem coeff_def {s : Unit →₀ ℕ} {n : ℕ} (h : s () = n) : coeff R n = MvPowerSeries.coeff R s := by
erw [coeff, ← h, ← Finsupp.unique_single s]
#align power_series.coeff_def PowerSeries.coeff_def
@[ext]
theorem ext {φ ψ : R⟦X⟧} (h : ∀ n, coeff R n φ = coeff R n ψ) : φ = ψ :=
MvPowerSeries.ext fun n => by
rw [← coeff_def]
· apply h
rfl
#align power_series.ext PowerSeries.ext
theorem ext_iff {φ ψ : R⟦X⟧} : φ = ψ ↔ ∀ n, coeff R n φ = coeff R n ψ :=
⟨fun h n => congr_arg (coeff R n) h, ext⟩
#align power_series.ext_iff PowerSeries.ext_iff
instance [Subsingleton R] : Subsingleton R⟦X⟧ := by
simp only [subsingleton_iff, ext_iff]
exact fun _ _ _ ↦ (subsingleton_iff).mp (by infer_instance) _ _
def mk {R} (f : ℕ → R) : R⟦X⟧ := fun s => f (s ())
#align power_series.mk PowerSeries.mk
@[simp]
theorem coeff_mk (n : ℕ) (f : ℕ → R) : coeff R n (mk f) = f n :=
congr_arg f Finsupp.single_eq_same
#align power_series.coeff_mk PowerSeries.coeff_mk
theorem coeff_monomial (m n : ℕ) (a : R) : coeff R m (monomial R n a) = if m = n then a else 0 :=
calc
coeff R m (monomial R n a) = _ := MvPowerSeries.coeff_monomial _ _ _
_ = if m = n then a else 0 := by simp only [Finsupp.unique_single_eq_iff]
#align power_series.coeff_monomial PowerSeries.coeff_monomial
theorem monomial_eq_mk (n : ℕ) (a : R) : monomial R n a = mk fun m => if m = n then a else 0 :=
ext fun m => by rw [coeff_monomial, coeff_mk]
#align power_series.monomial_eq_mk PowerSeries.monomial_eq_mk
@[simp]
theorem coeff_monomial_same (n : ℕ) (a : R) : coeff R n (monomial R n a) = a :=
MvPowerSeries.coeff_monomial_same _ _
#align power_series.coeff_monomial_same PowerSeries.coeff_monomial_same
@[simp]
theorem coeff_comp_monomial (n : ℕ) : (coeff R n).comp (monomial R n) = LinearMap.id :=
LinearMap.ext <| coeff_monomial_same n
#align power_series.coeff_comp_monomial PowerSeries.coeff_comp_monomial
variable (R)
def constantCoeff : R⟦X⟧ →+* R :=
MvPowerSeries.constantCoeff Unit R
#align power_series.constant_coeff PowerSeries.constantCoeff
def C : R →+* R⟦X⟧ :=
MvPowerSeries.C Unit R
set_option linter.uppercaseLean3 false in
#align power_series.C PowerSeries.C
variable {R}
def X : R⟦X⟧ :=
MvPowerSeries.X ()
set_option linter.uppercaseLean3 false in
#align power_series.X PowerSeries.X
theorem commute_X (φ : R⟦X⟧) : Commute φ X :=
MvPowerSeries.commute_X _ _
set_option linter.uppercaseLean3 false in
#align power_series.commute_X PowerSeries.commute_X
@[simp]
theorem coeff_zero_eq_constantCoeff : ⇑(coeff R 0) = constantCoeff R := by
rw [coeff, Finsupp.single_zero]
rfl
#align power_series.coeff_zero_eq_constant_coeff PowerSeries.coeff_zero_eq_constantCoeff
theorem coeff_zero_eq_constantCoeff_apply (φ : R⟦X⟧) : coeff R 0 φ = constantCoeff R φ := by
rw [coeff_zero_eq_constantCoeff]
#align power_series.coeff_zero_eq_constant_coeff_apply PowerSeries.coeff_zero_eq_constantCoeff_apply
@[simp]
theorem monomial_zero_eq_C : ⇑(monomial R 0) = C R := by
-- This used to be `rw`, but we need `erw` after leanprover/lean4#2644
erw [monomial, Finsupp.single_zero, MvPowerSeries.monomial_zero_eq_C]
set_option linter.uppercaseLean3 false in
#align power_series.monomial_zero_eq_C PowerSeries.monomial_zero_eq_C
theorem monomial_zero_eq_C_apply (a : R) : monomial R 0 a = C R a := by simp
set_option linter.uppercaseLean3 false in
#align power_series.monomial_zero_eq_C_apply PowerSeries.monomial_zero_eq_C_apply
theorem coeff_C (n : ℕ) (a : R) : coeff R n (C R a : R⟦X⟧) = if n = 0 then a else 0 := by
rw [← monomial_zero_eq_C_apply, coeff_monomial]
set_option linter.uppercaseLean3 false in
#align power_series.coeff_C PowerSeries.coeff_C
@[simp]
theorem coeff_zero_C (a : R) : coeff R 0 (C R a) = a := by
rw [coeff_C, if_pos rfl]
set_option linter.uppercaseLean3 false in
#align power_series.coeff_zero_C PowerSeries.coeff_zero_C
theorem coeff_ne_zero_C {a : R} {n : ℕ} (h : n ≠ 0) : coeff R n (C R a) = 0 := by
rw [coeff_C, if_neg h]
@[simp]
theorem coeff_succ_C {a : R} {n : ℕ} : coeff R (n + 1) (C R a) = 0 :=
coeff_ne_zero_C n.succ_ne_zero
theorem C_injective : Function.Injective (C R) := by
intro a b H
have := (ext_iff (φ := C R a) (ψ := C R b)).mp H 0
rwa [coeff_zero_C, coeff_zero_C] at this
protected theorem subsingleton_iff : Subsingleton R⟦X⟧ ↔ Subsingleton R := by
refine ⟨fun h ↦ ?_, fun _ ↦ inferInstance⟩
rw [subsingleton_iff] at h ⊢
exact fun a b ↦ C_injective (h (C R a) (C R b))
theorem X_eq : (X : R⟦X⟧) = monomial R 1 1 :=
rfl
set_option linter.uppercaseLean3 false in
#align power_series.X_eq PowerSeries.X_eq
theorem coeff_X (n : ℕ) : coeff R n (X : R⟦X⟧) = if n = 1 then 1 else 0 := by
rw [X_eq, coeff_monomial]
set_option linter.uppercaseLean3 false in
#align power_series.coeff_X PowerSeries.coeff_X
@[simp]
theorem coeff_zero_X : coeff R 0 (X : R⟦X⟧) = 0 := by
-- This used to be `rw`, but we need `erw` after leanprover/lean4#2644
erw [coeff, Finsupp.single_zero, X, MvPowerSeries.coeff_zero_X]
set_option linter.uppercaseLean3 false in
#align power_series.coeff_zero_X PowerSeries.coeff_zero_X
@[simp]
| Mathlib/RingTheory/PowerSeries/Basic.lean | 295 | 295 | theorem coeff_one_X : coeff R 1 (X : R⟦X⟧) = 1 := by | rw [coeff_X, if_pos rfl]
|
import Mathlib.Order.Filter.Basic
#align_import order.filter.prod from "leanprover-community/mathlib"@"d6fad0e5bf2d6f48da9175d25c3dc5706b3834ce"
open Set
open Filter
namespace Filter
variable {α β γ δ : Type*} {ι : Sort*}
section Prod
variable {s : Set α} {t : Set β} {f : Filter α} {g : Filter β}
protected def prod (f : Filter α) (g : Filter β) : Filter (α × β) :=
f.comap Prod.fst ⊓ g.comap Prod.snd
#align filter.prod Filter.prod
instance instSProd : SProd (Filter α) (Filter β) (Filter (α × β)) where
sprod := Filter.prod
theorem prod_mem_prod (hs : s ∈ f) (ht : t ∈ g) : s ×ˢ t ∈ f ×ˢ g :=
inter_mem_inf (preimage_mem_comap hs) (preimage_mem_comap ht)
#align filter.prod_mem_prod Filter.prod_mem_prod
theorem mem_prod_iff {s : Set (α × β)} {f : Filter α} {g : Filter β} :
s ∈ f ×ˢ g ↔ ∃ t₁ ∈ f, ∃ t₂ ∈ g, t₁ ×ˢ t₂ ⊆ s := by
simp only [SProd.sprod, Filter.prod]
constructor
· rintro ⟨t₁, ⟨s₁, hs₁, hts₁⟩, t₂, ⟨s₂, hs₂, hts₂⟩, rfl⟩
exact ⟨s₁, hs₁, s₂, hs₂, fun p ⟨h, h'⟩ => ⟨hts₁ h, hts₂ h'⟩⟩
· rintro ⟨t₁, ht₁, t₂, ht₂, h⟩
exact mem_inf_of_inter (preimage_mem_comap ht₁) (preimage_mem_comap ht₂) h
#align filter.mem_prod_iff Filter.mem_prod_iff
@[simp]
theorem prod_mem_prod_iff [f.NeBot] [g.NeBot] : s ×ˢ t ∈ f ×ˢ g ↔ s ∈ f ∧ t ∈ g :=
⟨fun h =>
let ⟨_s', hs', _t', ht', H⟩ := mem_prod_iff.1 h
(prod_subset_prod_iff.1 H).elim
(fun ⟨hs's, ht't⟩ => ⟨mem_of_superset hs' hs's, mem_of_superset ht' ht't⟩) fun h =>
h.elim (fun hs'e => absurd hs'e (nonempty_of_mem hs').ne_empty) fun ht'e =>
absurd ht'e (nonempty_of_mem ht').ne_empty,
fun h => prod_mem_prod h.1 h.2⟩
#align filter.prod_mem_prod_iff Filter.prod_mem_prod_iff
theorem mem_prod_principal {s : Set (α × β)} :
s ∈ f ×ˢ 𝓟 t ↔ { a | ∀ b ∈ t, (a, b) ∈ s } ∈ f := by
rw [← @exists_mem_subset_iff _ f, mem_prod_iff]
refine exists_congr fun u => Iff.rfl.and ⟨?_, fun h => ⟨t, mem_principal_self t, ?_⟩⟩
· rintro ⟨v, v_in, hv⟩ a a_in b b_in
exact hv (mk_mem_prod a_in <| v_in b_in)
· rintro ⟨x, y⟩ ⟨hx, hy⟩
exact h hx y hy
#align filter.mem_prod_principal Filter.mem_prod_principal
theorem mem_prod_top {s : Set (α × β)} :
s ∈ f ×ˢ (⊤ : Filter β) ↔ { a | ∀ b, (a, b) ∈ s } ∈ f := by
rw [← principal_univ, mem_prod_principal]
simp only [mem_univ, forall_true_left]
#align filter.mem_prod_top Filter.mem_prod_top
theorem eventually_prod_principal_iff {p : α × β → Prop} {s : Set β} :
(∀ᶠ x : α × β in f ×ˢ 𝓟 s, p x) ↔ ∀ᶠ x : α in f, ∀ y : β, y ∈ s → p (x, y) := by
rw [eventually_iff, eventually_iff, mem_prod_principal]
simp only [mem_setOf_eq]
#align filter.eventually_prod_principal_iff Filter.eventually_prod_principal_iff
theorem comap_prod (f : α → β × γ) (b : Filter β) (c : Filter γ) :
comap f (b ×ˢ c) = comap (Prod.fst ∘ f) b ⊓ comap (Prod.snd ∘ f) c := by
erw [comap_inf, Filter.comap_comap, Filter.comap_comap]
#align filter.comap_prod Filter.comap_prod
theorem prod_top : f ×ˢ (⊤ : Filter β) = f.comap Prod.fst := by
dsimp only [SProd.sprod]
rw [Filter.prod, comap_top, inf_top_eq]
#align filter.prod_top Filter.prod_top
theorem top_prod : (⊤ : Filter α) ×ˢ g = g.comap Prod.snd := by
dsimp only [SProd.sprod]
rw [Filter.prod, comap_top, top_inf_eq]
theorem sup_prod (f₁ f₂ : Filter α) (g : Filter β) : (f₁ ⊔ f₂) ×ˢ g = (f₁ ×ˢ g) ⊔ (f₂ ×ˢ g) := by
dsimp only [SProd.sprod]
rw [Filter.prod, comap_sup, inf_sup_right, ← Filter.prod, ← Filter.prod]
#align filter.sup_prod Filter.sup_prod
theorem prod_sup (f : Filter α) (g₁ g₂ : Filter β) : f ×ˢ (g₁ ⊔ g₂) = (f ×ˢ g₁) ⊔ (f ×ˢ g₂) := by
dsimp only [SProd.sprod]
rw [Filter.prod, comap_sup, inf_sup_left, ← Filter.prod, ← Filter.prod]
#align filter.prod_sup Filter.prod_sup
theorem eventually_prod_iff {p : α × β → Prop} :
(∀ᶠ x in f ×ˢ g, p x) ↔
∃ pa : α → Prop, (∀ᶠ x in f, pa x) ∧ ∃ pb : β → Prop, (∀ᶠ y in g, pb y) ∧
∀ {x}, pa x → ∀ {y}, pb y → p (x, y) := by
simpa only [Set.prod_subset_iff] using @mem_prod_iff α β p f g
#align filter.eventually_prod_iff Filter.eventually_prod_iff
theorem tendsto_fst : Tendsto Prod.fst (f ×ˢ g) f :=
tendsto_inf_left tendsto_comap
#align filter.tendsto_fst Filter.tendsto_fst
theorem tendsto_snd : Tendsto Prod.snd (f ×ˢ g) g :=
tendsto_inf_right tendsto_comap
#align filter.tendsto_snd Filter.tendsto_snd
theorem Tendsto.fst {h : Filter γ} {m : α → β × γ} (H : Tendsto m f (g ×ˢ h)) :
Tendsto (fun a ↦ (m a).1) f g :=
tendsto_fst.comp H
theorem Tendsto.snd {h : Filter γ} {m : α → β × γ} (H : Tendsto m f (g ×ˢ h)) :
Tendsto (fun a ↦ (m a).2) f h :=
tendsto_snd.comp H
theorem Tendsto.prod_mk {h : Filter γ} {m₁ : α → β} {m₂ : α → γ}
(h₁ : Tendsto m₁ f g) (h₂ : Tendsto m₂ f h) : Tendsto (fun x => (m₁ x, m₂ x)) f (g ×ˢ h) :=
tendsto_inf.2 ⟨tendsto_comap_iff.2 h₁, tendsto_comap_iff.2 h₂⟩
#align filter.tendsto.prod_mk Filter.Tendsto.prod_mk
theorem tendsto_prod_swap : Tendsto (Prod.swap : α × β → β × α) (f ×ˢ g) (g ×ˢ f) :=
tendsto_snd.prod_mk tendsto_fst
#align filter.tendsto_prod_swap Filter.tendsto_prod_swap
theorem Eventually.prod_inl {la : Filter α} {p : α → Prop} (h : ∀ᶠ x in la, p x) (lb : Filter β) :
∀ᶠ x in la ×ˢ lb, p (x : α × β).1 :=
tendsto_fst.eventually h
#align filter.eventually.prod_inl Filter.Eventually.prod_inl
theorem Eventually.prod_inr {lb : Filter β} {p : β → Prop} (h : ∀ᶠ x in lb, p x) (la : Filter α) :
∀ᶠ x in la ×ˢ lb, p (x : α × β).2 :=
tendsto_snd.eventually h
#align filter.eventually.prod_inr Filter.Eventually.prod_inr
theorem Eventually.prod_mk {la : Filter α} {pa : α → Prop} (ha : ∀ᶠ x in la, pa x) {lb : Filter β}
{pb : β → Prop} (hb : ∀ᶠ y in lb, pb y) : ∀ᶠ p in la ×ˢ lb, pa (p : α × β).1 ∧ pb p.2 :=
(ha.prod_inl lb).and (hb.prod_inr la)
#align filter.eventually.prod_mk Filter.Eventually.prod_mk
theorem EventuallyEq.prod_map {δ} {la : Filter α} {fa ga : α → γ} (ha : fa =ᶠ[la] ga)
{lb : Filter β} {fb gb : β → δ} (hb : fb =ᶠ[lb] gb) :
Prod.map fa fb =ᶠ[la ×ˢ lb] Prod.map ga gb :=
(Eventually.prod_mk ha hb).mono fun _ h => Prod.ext h.1 h.2
#align filter.eventually_eq.prod_map Filter.EventuallyEq.prod_map
theorem EventuallyLE.prod_map {δ} [LE γ] [LE δ] {la : Filter α} {fa ga : α → γ} (ha : fa ≤ᶠ[la] ga)
{lb : Filter β} {fb gb : β → δ} (hb : fb ≤ᶠ[lb] gb) :
Prod.map fa fb ≤ᶠ[la ×ˢ lb] Prod.map ga gb :=
Eventually.prod_mk ha hb
#align filter.eventually_le.prod_map Filter.EventuallyLE.prod_map
theorem Eventually.curry {la : Filter α} {lb : Filter β} {p : α × β → Prop}
(h : ∀ᶠ x in la ×ˢ lb, p x) : ∀ᶠ x in la, ∀ᶠ y in lb, p (x, y) := by
rcases eventually_prod_iff.1 h with ⟨pa, ha, pb, hb, h⟩
exact ha.mono fun a ha => hb.mono fun b hb => h ha hb
#align filter.eventually.curry Filter.Eventually.curry
protected lemma Frequently.uncurry {la : Filter α} {lb : Filter β} {p : α → β → Prop}
(h : ∃ᶠ x in la, ∃ᶠ y in lb, p x y) : ∃ᶠ xy in la ×ˢ lb, p xy.1 xy.2 :=
mt (fun h ↦ by simpa only [not_frequently] using h.curry) h
theorem Eventually.diag_of_prod {p : α × α → Prop} (h : ∀ᶠ i in f ×ˢ f, p i) :
∀ᶠ i in f, p (i, i) := by
obtain ⟨t, ht, s, hs, hst⟩ := eventually_prod_iff.1 h
apply (ht.and hs).mono fun x hx => hst hx.1 hx.2
#align filter.eventually.diag_of_prod Filter.Eventually.diag_of_prod
theorem Eventually.diag_of_prod_left {f : Filter α} {g : Filter γ} {p : (α × α) × γ → Prop} :
(∀ᶠ x in (f ×ˢ f) ×ˢ g, p x) → ∀ᶠ x : α × γ in f ×ˢ g, p ((x.1, x.1), x.2) := by
intro h
obtain ⟨t, ht, s, hs, hst⟩ := eventually_prod_iff.1 h
exact (ht.diag_of_prod.prod_mk hs).mono fun x hx => by simp only [hst hx.1 hx.2]
#align filter.eventually.diag_of_prod_left Filter.Eventually.diag_of_prod_left
| Mathlib/Order/Filter/Prod.lean | 221 | 225 | theorem Eventually.diag_of_prod_right {f : Filter α} {g : Filter γ} {p : α × γ × γ → Prop} :
(∀ᶠ x in f ×ˢ (g ×ˢ g), p x) → ∀ᶠ x : α × γ in f ×ˢ g, p (x.1, x.2, x.2) := by |
intro h
obtain ⟨t, ht, s, hs, hst⟩ := eventually_prod_iff.1 h
exact (ht.prod_mk hs.diag_of_prod).mono fun x hx => by simp only [hst hx.1 hx.2]
|
import Mathlib.LinearAlgebra.Basis
import Mathlib.Algebra.FreeAlgebra
import Mathlib.LinearAlgebra.FinsuppVectorSpace
import Mathlib.LinearAlgebra.FreeModule.StrongRankCondition
import Mathlib.LinearAlgebra.Dimension.StrongRankCondition
#align_import linear_algebra.free_algebra from "leanprover-community/mathlib"@"039a089d2a4b93c761b234f3e5f5aeb752bac60f"
universe u v
namespace FreeAlgebra
variable (R : Type u) (X : Type v)
section
variable [CommSemiring R]
-- @[simps]
noncomputable def basisFreeMonoid : Basis (FreeMonoid X) R (FreeAlgebra R X) :=
Finsupp.basisSingleOne.map (equivMonoidAlgebraFreeMonoid (R := R) (X := X)).symm.toLinearEquiv
#align free_algebra.basis_free_monoid FreeAlgebra.basisFreeMonoid
instance : Module.Free R (FreeAlgebra R X) :=
have : Module.Free R (MonoidAlgebra R (FreeMonoid X)) := Module.Free.finsupp _ _ _
Module.Free.of_equiv (equivMonoidAlgebraFreeMonoid (R := R) (X := X)).symm.toLinearEquiv
end
| Mathlib/LinearAlgebra/FreeAlgebra.lean | 44 | 47 | theorem rank_eq [CommRing R] [Nontrivial R] :
Module.rank R (FreeAlgebra R X) = Cardinal.lift.{u} (Cardinal.mk (List X)) := by |
rw [← (Basis.mk_eq_rank'.{_,_,_,u} (basisFreeMonoid R X)).trans (Cardinal.lift_id _),
Cardinal.lift_umax'.{v,u}, FreeMonoid]
|
import Mathlib.Topology.MetricSpace.HausdorffDistance
#align_import topology.metric_space.pi_nat from "leanprover-community/mathlib"@"49b7f94aab3a3bdca1f9f34c5d818afb253b3993"
noncomputable section
open scoped Classical
open Topology Filter
open TopologicalSpace Set Metric Filter Function
attribute [local simp] pow_le_pow_iff_right one_lt_two inv_le_inv zero_le_two zero_lt_two
variable {E : ℕ → Type*}
namespace PiNat
irreducible_def firstDiff (x y : ∀ n, E n) : ℕ :=
if h : x ≠ y then Nat.find (ne_iff.1 h) else 0
#align pi_nat.first_diff PiNat.firstDiff
theorem apply_firstDiff_ne {x y : ∀ n, E n} (h : x ≠ y) :
x (firstDiff x y) ≠ y (firstDiff x y) := by
rw [firstDiff_def, dif_pos h]
exact Nat.find_spec (ne_iff.1 h)
#align pi_nat.apply_first_diff_ne PiNat.apply_firstDiff_ne
| Mathlib/Topology/MetricSpace/PiNat.lean | 80 | 85 | theorem apply_eq_of_lt_firstDiff {x y : ∀ n, E n} {n : ℕ} (hn : n < firstDiff x y) : x n = y n := by |
rw [firstDiff_def] at hn
split_ifs at hn with h
· convert Nat.find_min (ne_iff.1 h) hn
simp
· exact (not_lt_zero' hn).elim
|
import Mathlib.Algebra.BigOperators.NatAntidiagonal
import Mathlib.Algebra.Order.Ring.Abs
import Mathlib.Data.Nat.Choose.Sum
import Mathlib.RingTheory.PowerSeries.Basic
#align_import ring_theory.power_series.well_known from "leanprover-community/mathlib"@"8199f6717c150a7fe91c4534175f4cf99725978f"
namespace PowerSeries
section Field
variable (A A' : Type*) [Ring A] [Ring A'] [Algebra ℚ A] [Algebra ℚ A']
open Nat
def exp : PowerSeries A :=
mk fun n => algebraMap ℚ A (1 / n !)
#align power_series.exp PowerSeries.exp
def sin : PowerSeries A :=
mk fun n => if Even n then 0 else algebraMap ℚ A ((-1) ^ (n / 2) / n !)
#align power_series.sin PowerSeries.sin
def cos : PowerSeries A :=
mk fun n => if Even n then algebraMap ℚ A ((-1) ^ (n / 2) / n !) else 0
#align power_series.cos PowerSeries.cos
variable {A A'} [Ring A] [Ring A'] [Algebra ℚ A] [Algebra ℚ A'] (n : ℕ) (f : A →+* A')
@[simp]
theorem coeff_exp : coeff A n (exp A) = algebraMap ℚ A (1 / n !) :=
coeff_mk _ _
#align power_series.coeff_exp PowerSeries.coeff_exp
@[simp]
theorem constantCoeff_exp : constantCoeff A (exp A) = 1 := by
rw [← coeff_zero_eq_constantCoeff_apply, coeff_exp]
simp
#align power_series.constant_coeff_exp PowerSeries.constantCoeff_exp
set_option linter.deprecated false in
@[simp]
theorem coeff_sin_bit0 : coeff A (bit0 n) (sin A) = 0 := by
rw [sin, coeff_mk, if_pos (even_bit0 n)]
#align power_series.coeff_sin_bit0 PowerSeries.coeff_sin_bit0
set_option linter.deprecated false in
@[simp]
theorem coeff_sin_bit1 : coeff A (bit1 n) (sin A) = (-1) ^ n * coeff A (bit1 n) (exp A) := by
rw [sin, coeff_mk, if_neg n.not_even_bit1, Nat.bit1_div_two, ← mul_one_div, map_mul, map_pow,
map_neg, map_one, coeff_exp]
#align power_series.coeff_sin_bit1 PowerSeries.coeff_sin_bit1
set_option linter.deprecated false in
@[simp]
theorem coeff_cos_bit0 : coeff A (bit0 n) (cos A) = (-1) ^ n * coeff A (bit0 n) (exp A) := by
rw [cos, coeff_mk, if_pos (even_bit0 n), Nat.bit0_div_two, ← mul_one_div, map_mul, map_pow,
map_neg, map_one, coeff_exp]
#align power_series.coeff_cos_bit0 PowerSeries.coeff_cos_bit0
set_option linter.deprecated false in
@[simp]
theorem coeff_cos_bit1 : coeff A (bit1 n) (cos A) = 0 := by
rw [cos, coeff_mk, if_neg n.not_even_bit1]
#align power_series.coeff_cos_bit1 PowerSeries.coeff_cos_bit1
@[simp]
theorem map_exp : map (f : A →+* A') (exp A) = exp A' := by
ext
simp
#align power_series.map_exp PowerSeries.map_exp
@[simp]
| Mathlib/RingTheory/PowerSeries/WellKnown.lean | 212 | 214 | theorem map_sin : map f (sin A) = sin A' := by |
ext
simp [sin, apply_ite f]
|
import Mathlib.Analysis.Calculus.Deriv.Basic
import Mathlib.Analysis.Calculus.FDeriv.Mul
import Mathlib.Analysis.Calculus.FDeriv.Add
#align_import analysis.calculus.deriv.mul from "leanprover-community/mathlib"@"3bce8d800a6f2b8f63fe1e588fd76a9ff4adcebe"
universe u v w
noncomputable section
open scoped Classical Topology Filter ENNReal
open Filter Asymptotics Set
open ContinuousLinearMap (smulRight smulRight_one_eq_iff)
variable {𝕜 : Type u} [NontriviallyNormedField 𝕜]
variable {F : Type v} [NormedAddCommGroup F] [NormedSpace 𝕜 F]
variable {E : Type w} [NormedAddCommGroup E] [NormedSpace 𝕜 E]
variable {G : Type*} [NormedAddCommGroup G] [NormedSpace 𝕜 G]
variable {f f₀ f₁ g : 𝕜 → F}
variable {f' f₀' f₁' g' : F}
variable {x : 𝕜}
variable {s t : Set 𝕜}
variable {L L₁ L₂ : Filter 𝕜}
section SMul
variable {𝕜' : Type*} [NontriviallyNormedField 𝕜'] [NormedAlgebra 𝕜 𝕜'] [NormedSpace 𝕜' F]
[IsScalarTower 𝕜 𝕜' F] {c : 𝕜 → 𝕜'} {c' : 𝕜'}
theorem HasDerivWithinAt.smul (hc : HasDerivWithinAt c c' s x) (hf : HasDerivWithinAt f f' s x) :
HasDerivWithinAt (fun y => c y • f y) (c x • f' + c' • f x) s x := by
simpa using (HasFDerivWithinAt.smul hc hf).hasDerivWithinAt
#align has_deriv_within_at.smul HasDerivWithinAt.smul
theorem HasDerivAt.smul (hc : HasDerivAt c c' x) (hf : HasDerivAt f f' x) :
HasDerivAt (fun y => c y • f y) (c x • f' + c' • f x) x := by
rw [← hasDerivWithinAt_univ] at *
exact hc.smul hf
#align has_deriv_at.smul HasDerivAt.smul
nonrec theorem HasStrictDerivAt.smul (hc : HasStrictDerivAt c c' x) (hf : HasStrictDerivAt f f' x) :
HasStrictDerivAt (fun y => c y • f y) (c x • f' + c' • f x) x := by
simpa using (hc.smul hf).hasStrictDerivAt
#align has_strict_deriv_at.smul HasStrictDerivAt.smul
theorem derivWithin_smul (hxs : UniqueDiffWithinAt 𝕜 s x) (hc : DifferentiableWithinAt 𝕜 c s x)
(hf : DifferentiableWithinAt 𝕜 f s x) :
derivWithin (fun y => c y • f y) s x = c x • derivWithin f s x + derivWithin c s x • f x :=
(hc.hasDerivWithinAt.smul hf.hasDerivWithinAt).derivWithin hxs
#align deriv_within_smul derivWithin_smul
theorem deriv_smul (hc : DifferentiableAt 𝕜 c x) (hf : DifferentiableAt 𝕜 f x) :
deriv (fun y => c y • f y) x = c x • deriv f x + deriv c x • f x :=
(hc.hasDerivAt.smul hf.hasDerivAt).deriv
#align deriv_smul deriv_smul
theorem HasStrictDerivAt.smul_const (hc : HasStrictDerivAt c c' x) (f : F) :
HasStrictDerivAt (fun y => c y • f) (c' • f) x := by
have := hc.smul (hasStrictDerivAt_const x f)
rwa [smul_zero, zero_add] at this
#align has_strict_deriv_at.smul_const HasStrictDerivAt.smul_const
theorem HasDerivWithinAt.smul_const (hc : HasDerivWithinAt c c' s x) (f : F) :
HasDerivWithinAt (fun y => c y • f) (c' • f) s x := by
have := hc.smul (hasDerivWithinAt_const x s f)
rwa [smul_zero, zero_add] at this
#align has_deriv_within_at.smul_const HasDerivWithinAt.smul_const
| Mathlib/Analysis/Calculus/Deriv/Mul.lean | 126 | 129 | theorem HasDerivAt.smul_const (hc : HasDerivAt c c' x) (f : F) :
HasDerivAt (fun y => c y • f) (c' • f) x := by |
rw [← hasDerivWithinAt_univ] at *
exact hc.smul_const f
|
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]
| Mathlib/Analysis/SpecialFunctions/Trigonometric/Angle.lean | 785 | 786 | theorem tan_coe (x : ℝ) : tan (x : Angle) = Real.tan x := by |
rw [tan, sin_coe, cos_coe, Real.tan_eq_sin_div_cos]
|
import Mathlib.Analysis.Calculus.FDeriv.Bilinear
#align_import analysis.calculus.fderiv.mul from "leanprover-community/mathlib"@"d608fc5d4e69d4cc21885913fb573a88b0deb521"
open scoped Classical
open Filter Asymptotics ContinuousLinearMap Set Metric Topology NNReal ENNReal
noncomputable section
section
variable {𝕜 : Type*} [NontriviallyNormedField 𝕜]
variable {E : Type*} [NormedAddCommGroup E] [NormedSpace 𝕜 E]
variable {F : Type*} [NormedAddCommGroup F] [NormedSpace 𝕜 F]
variable {G : Type*} [NormedAddCommGroup G] [NormedSpace 𝕜 G]
variable {G' : Type*} [NormedAddCommGroup G'] [NormedSpace 𝕜 G']
variable {f f₀ f₁ g : E → F}
variable {f' f₀' f₁' g' : E →L[𝕜] F}
variable (e : E →L[𝕜] F)
variable {x : E}
variable {s t : Set E}
variable {L L₁ L₂ : Filter E}
section Mul
variable {𝔸 𝔸' : Type*} [NormedRing 𝔸] [NormedCommRing 𝔸'] [NormedAlgebra 𝕜 𝔸] [NormedAlgebra 𝕜 𝔸']
{a b : E → 𝔸} {a' b' : E →L[𝕜] 𝔸} {c d : E → 𝔸'} {c' d' : E →L[𝕜] 𝔸'}
@[fun_prop]
theorem HasStrictFDerivAt.mul' {x : E} (ha : HasStrictFDerivAt a a' x)
(hb : HasStrictFDerivAt b b' x) :
HasStrictFDerivAt (fun y => a y * b y) (a x • b' + a'.smulRight (b x)) x :=
((ContinuousLinearMap.mul 𝕜 𝔸).isBoundedBilinearMap.hasStrictFDerivAt (a x, b x)).comp x
(ha.prod hb)
#align has_strict_fderiv_at.mul' HasStrictFDerivAt.mul'
@[fun_prop]
theorem HasStrictFDerivAt.mul (hc : HasStrictFDerivAt c c' x) (hd : HasStrictFDerivAt d d' x) :
HasStrictFDerivAt (fun y => c y * d y) (c x • d' + d x • c') x := by
convert hc.mul' hd
ext z
apply mul_comm
#align has_strict_fderiv_at.mul HasStrictFDerivAt.mul
@[fun_prop]
theorem HasFDerivWithinAt.mul' (ha : HasFDerivWithinAt a a' s x) (hb : HasFDerivWithinAt b b' s x) :
HasFDerivWithinAt (fun y => a y * b y) (a x • b' + a'.smulRight (b x)) s x :=
((ContinuousLinearMap.mul 𝕜 𝔸).isBoundedBilinearMap.hasFDerivAt (a x, b x)).comp_hasFDerivWithinAt
x (ha.prod hb)
#align has_fderiv_within_at.mul' HasFDerivWithinAt.mul'
@[fun_prop]
theorem HasFDerivWithinAt.mul (hc : HasFDerivWithinAt c c' s x) (hd : HasFDerivWithinAt d d' s x) :
HasFDerivWithinAt (fun y => c y * d y) (c x • d' + d x • c') s x := by
convert hc.mul' hd
ext z
apply mul_comm
#align has_fderiv_within_at.mul HasFDerivWithinAt.mul
@[fun_prop]
theorem HasFDerivAt.mul' (ha : HasFDerivAt a a' x) (hb : HasFDerivAt b b' x) :
HasFDerivAt (fun y => a y * b y) (a x • b' + a'.smulRight (b x)) x :=
((ContinuousLinearMap.mul 𝕜 𝔸).isBoundedBilinearMap.hasFDerivAt (a x, b x)).comp x (ha.prod hb)
#align has_fderiv_at.mul' HasFDerivAt.mul'
@[fun_prop]
| Mathlib/Analysis/Calculus/FDeriv/Mul.lean | 405 | 409 | theorem HasFDerivAt.mul (hc : HasFDerivAt c c' x) (hd : HasFDerivAt d d' x) :
HasFDerivAt (fun y => c y * d y) (c x • d' + d x • c') x := by |
convert hc.mul' hd
ext z
apply mul_comm
|
import Mathlib.Analysis.Calculus.Deriv.Basic
import Mathlib.Analysis.Calculus.FDeriv.Comp
import Mathlib.Analysis.Calculus.FDeriv.RestrictScalars
#align_import analysis.calculus.deriv.comp from "leanprover-community/mathlib"@"3bce8d800a6f2b8f63fe1e588fd76a9ff4adcebe"
universe u v w
open scoped Classical
open Topology Filter ENNReal
open Filter Asymptotics Set
open ContinuousLinearMap (smulRight smulRight_one_eq_iff)
variable {𝕜 : Type u} [NontriviallyNormedField 𝕜]
variable {F : Type v} [NormedAddCommGroup F] [NormedSpace 𝕜 F]
variable {E : Type w} [NormedAddCommGroup E] [NormedSpace 𝕜 E]
variable {f f₀ f₁ g : 𝕜 → F}
variable {f' f₀' f₁' g' : F}
variable {x : 𝕜}
variable {s t : Set 𝕜}
variable {L L₁ L₂ : Filter 𝕜}
section Composition
variable {𝕜' : Type*} [NontriviallyNormedField 𝕜'] [NormedAlgebra 𝕜 𝕜'] [NormedSpace 𝕜' F]
[IsScalarTower 𝕜 𝕜' F] {s' t' : Set 𝕜'} {h : 𝕜 → 𝕜'} {h₁ : 𝕜 → 𝕜} {h₂ : 𝕜' → 𝕜'} {h' h₂' : 𝕜'}
{h₁' : 𝕜} {g₁ : 𝕜' → F} {g₁' : F} {L' : Filter 𝕜'} {y : 𝕜'} (x)
theorem HasDerivAtFilter.scomp (hg : HasDerivAtFilter g₁ g₁' (h x) L')
(hh : HasDerivAtFilter h h' x L) (hL : Tendsto h L L') :
HasDerivAtFilter (g₁ ∘ h) (h' • g₁') x L := by
simpa using ((hg.restrictScalars 𝕜).comp x hh hL).hasDerivAtFilter
#align has_deriv_at_filter.scomp HasDerivAtFilter.scomp
theorem HasDerivAtFilter.scomp_of_eq (hg : HasDerivAtFilter g₁ g₁' y L')
(hh : HasDerivAtFilter h h' x L) (hy : y = h x) (hL : Tendsto h L L') :
HasDerivAtFilter (g₁ ∘ h) (h' • g₁') x L := by
rw [hy] at hg; exact hg.scomp x hh hL
theorem HasDerivWithinAt.scomp_hasDerivAt (hg : HasDerivWithinAt g₁ g₁' s' (h x))
(hh : HasDerivAt h h' x) (hs : ∀ x, h x ∈ s') : HasDerivAt (g₁ ∘ h) (h' • g₁') x :=
hg.scomp x hh <| tendsto_inf.2 ⟨hh.continuousAt, tendsto_principal.2 <| eventually_of_forall hs⟩
#align has_deriv_within_at.scomp_has_deriv_at HasDerivWithinAt.scomp_hasDerivAt
theorem HasDerivWithinAt.scomp_hasDerivAt_of_eq (hg : HasDerivWithinAt g₁ g₁' s' y)
(hh : HasDerivAt h h' x) (hs : ∀ x, h x ∈ s') (hy : y = h x) :
HasDerivAt (g₁ ∘ h) (h' • g₁') x := by
rw [hy] at hg; exact hg.scomp_hasDerivAt x hh hs
nonrec theorem HasDerivWithinAt.scomp (hg : HasDerivWithinAt g₁ g₁' t' (h x))
(hh : HasDerivWithinAt h h' s x) (hst : MapsTo h s t') :
HasDerivWithinAt (g₁ ∘ h) (h' • g₁') s x :=
hg.scomp x hh <| hh.continuousWithinAt.tendsto_nhdsWithin hst
#align has_deriv_within_at.scomp HasDerivWithinAt.scomp
theorem HasDerivWithinAt.scomp_of_eq (hg : HasDerivWithinAt g₁ g₁' t' y)
(hh : HasDerivWithinAt h h' s x) (hst : MapsTo h s t') (hy : y = h x) :
HasDerivWithinAt (g₁ ∘ h) (h' • g₁') s x := by
rw [hy] at hg; exact hg.scomp x hh hst
nonrec theorem HasDerivAt.scomp (hg : HasDerivAt g₁ g₁' (h x)) (hh : HasDerivAt h h' x) :
HasDerivAt (g₁ ∘ h) (h' • g₁') x :=
hg.scomp x hh hh.continuousAt
#align has_deriv_at.scomp HasDerivAt.scomp
theorem HasDerivAt.scomp_of_eq
(hg : HasDerivAt g₁ g₁' y) (hh : HasDerivAt h h' x) (hy : y = h x) :
HasDerivAt (g₁ ∘ h) (h' • g₁') x := by
rw [hy] at hg; exact hg.scomp x hh
theorem HasStrictDerivAt.scomp (hg : HasStrictDerivAt g₁ g₁' (h x)) (hh : HasStrictDerivAt h h' x) :
HasStrictDerivAt (g₁ ∘ h) (h' • g₁') x := by
simpa using ((hg.restrictScalars 𝕜).comp x hh).hasStrictDerivAt
#align has_strict_deriv_at.scomp HasStrictDerivAt.scomp
theorem HasStrictDerivAt.scomp_of_eq
(hg : HasStrictDerivAt g₁ g₁' y) (hh : HasStrictDerivAt h h' x) (hy : y = h x) :
HasStrictDerivAt (g₁ ∘ h) (h' • g₁') x := by
rw [hy] at hg; exact hg.scomp x hh
theorem HasDerivAt.scomp_hasDerivWithinAt (hg : HasDerivAt g₁ g₁' (h x))
(hh : HasDerivWithinAt h h' s x) : HasDerivWithinAt (g₁ ∘ h) (h' • g₁') s x :=
HasDerivWithinAt.scomp x hg.hasDerivWithinAt hh (mapsTo_univ _ _)
#align has_deriv_at.scomp_has_deriv_within_at HasDerivAt.scomp_hasDerivWithinAt
theorem HasDerivAt.scomp_hasDerivWithinAt_of_eq (hg : HasDerivAt g₁ g₁' y)
(hh : HasDerivWithinAt h h' s x) (hy : y = h x) :
HasDerivWithinAt (g₁ ∘ h) (h' • g₁') s x := by
rw [hy] at hg; exact hg.scomp_hasDerivWithinAt x hh
theorem derivWithin.scomp (hg : DifferentiableWithinAt 𝕜' g₁ t' (h x))
(hh : DifferentiableWithinAt 𝕜 h s x) (hs : MapsTo h s t') (hxs : UniqueDiffWithinAt 𝕜 s x) :
derivWithin (g₁ ∘ h) s x = derivWithin h s x • derivWithin g₁ t' (h x) :=
(HasDerivWithinAt.scomp x hg.hasDerivWithinAt hh.hasDerivWithinAt hs).derivWithin hxs
#align deriv_within.scomp derivWithin.scomp
theorem derivWithin.scomp_of_eq (hg : DifferentiableWithinAt 𝕜' g₁ t' y)
(hh : DifferentiableWithinAt 𝕜 h s x) (hs : MapsTo h s t') (hxs : UniqueDiffWithinAt 𝕜 s x)
(hy : y = h x) :
derivWithin (g₁ ∘ h) s x = derivWithin h s x • derivWithin g₁ t' (h x) := by
rw [hy] at hg; exact derivWithin.scomp x hg hh hs hxs
theorem deriv.scomp (hg : DifferentiableAt 𝕜' g₁ (h x)) (hh : DifferentiableAt 𝕜 h x) :
deriv (g₁ ∘ h) x = deriv h x • deriv g₁ (h x) :=
(HasDerivAt.scomp x hg.hasDerivAt hh.hasDerivAt).deriv
#align deriv.scomp deriv.scomp
theorem deriv.scomp_of_eq
(hg : DifferentiableAt 𝕜' g₁ y) (hh : DifferentiableAt 𝕜 h x) (hy : y = h x) :
deriv (g₁ ∘ h) x = deriv h x • deriv g₁ (h x) := by
rw [hy] at hg; exact deriv.scomp x hg hh
theorem HasDerivAtFilter.comp_hasFDerivAtFilter {f : E → 𝕜'} {f' : E →L[𝕜] 𝕜'} (x) {L'' : Filter E}
(hh₂ : HasDerivAtFilter h₂ h₂' (f x) L') (hf : HasFDerivAtFilter f f' x L'')
(hL : Tendsto f L'' L') : HasFDerivAtFilter (h₂ ∘ f) (h₂' • f') x L'' := by
convert (hh₂.restrictScalars 𝕜).comp x hf hL
ext x
simp [mul_comm]
#align has_deriv_at_filter.comp_has_fderiv_at_filter HasDerivAtFilter.comp_hasFDerivAtFilter
| Mathlib/Analysis/Calculus/Deriv/Comp.lean | 170 | 174 | theorem HasDerivAtFilter.comp_hasFDerivAtFilter_of_eq
{f : E → 𝕜'} {f' : E →L[𝕜] 𝕜'} (x) {L'' : Filter E}
(hh₂ : HasDerivAtFilter h₂ h₂' y L') (hf : HasFDerivAtFilter f f' x L'')
(hL : Tendsto f L'' L') (hy : y = f x) : HasFDerivAtFilter (h₂ ∘ f) (h₂' • f') x L'' := by |
rw [hy] at hh₂; exact hh₂.comp_hasFDerivAtFilter x hf hL
|
import Mathlib.Data.Setoid.Partition
import Mathlib.GroupTheory.GroupAction.Basic
import Mathlib.GroupTheory.GroupAction.Pointwise
import Mathlib.GroupTheory.GroupAction.SubMulAction
open scoped BigOperators Pointwise
namespace MulAction
section SMul
variable (G : Type*) {X : Type*} [SMul G X]
-- Change terminology : is_fully_invariant ?
def IsFixedBlock (B : Set X) := ∀ g : G, g • B = B
def IsInvariantBlock (B : Set X) := ∀ g : G, g • B ⊆ B
def IsTrivialBlock (B : Set X) := B.Subsingleton ∨ B = ⊤
def IsBlock (B : Set X) := (Set.range fun g : G => g • B).PairwiseDisjoint id
variable {G}
| Mathlib/GroupTheory/GroupAction/Blocks.lean | 85 | 87 | theorem IsBlock.def {B : Set X} :
IsBlock G B ↔ ∀ g g' : G, g • B = g' • B ∨ Disjoint (g • B) (g' • B) := by |
apply Set.pairwiseDisjoint_range_iff
|
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
theorem nthLe_range'_1 {n m} (i) (H : i < (range' n m).length) :
nthLe (range' n m) i H = n + i := by simp
#align list.nth_le_range' List.nthLe_range'_1
#align list.range'_concat List.range'_concat
#align list.range_core List.range.loop
#align list.range_core_range' List.range_loop_range'
#align list.range_eq_range' List.range_eq_range'
#align list.range_succ_eq_map List.range_succ_eq_map
#align list.range'_eq_map_range List.range'_eq_map_range
#align list.length_range List.length_range
#align list.range_eq_nil List.range_eq_nil
theorem pairwise_lt_range (n : ℕ) : Pairwise (· < ·) (range n) := by
simp (config := {decide := true}) only [range_eq_range', pairwise_lt_range']
#align list.pairwise_lt_range List.pairwise_lt_range
theorem pairwise_le_range (n : ℕ) : Pairwise (· ≤ ·) (range n) :=
Pairwise.imp (@le_of_lt ℕ _) (pairwise_lt_range _)
#align list.pairwise_le_range List.pairwise_le_range
theorem take_range (m n : ℕ) : take m (range n) = range (min m n) := by
apply List.ext_get
· simp
· simp (config := { contextual := true }) [← get_take, Nat.lt_min]
theorem nodup_range (n : ℕ) : Nodup (range n) := by
simp (config := {decide := true}) only [range_eq_range', nodup_range']
#align list.nodup_range List.nodup_range
#align list.range_sublist List.range_sublist
#align list.range_subset List.range_subset
#align list.mem_range List.mem_range
#align list.not_mem_range_self List.not_mem_range_self
#align list.self_mem_range_succ List.self_mem_range_succ
#align list.nth_range List.get?_range
#align list.range_succ List.range_succ
#align list.range_zero List.range_zero
theorem chain'_range_succ (r : ℕ → ℕ → Prop) (n : ℕ) :
Chain' r (range n.succ) ↔ ∀ m < n, r m m.succ := by
rw [range_succ]
induction' n with n hn
· simp
· rw [range_succ]
simp only [append_assoc, singleton_append, chain'_append_cons_cons, chain'_singleton,
and_true_iff]
rw [hn, forall_lt_succ]
#align list.chain'_range_succ List.chain'_range_succ
theorem chain_range_succ (r : ℕ → ℕ → Prop) (n a : ℕ) :
Chain r a (range n.succ) ↔ r a 0 ∧ ∀ m < n, r m m.succ := by
rw [range_succ_eq_map, chain_cons, and_congr_right_iff, ← chain'_range_succ, range_succ_eq_map]
exact fun _ => Iff.rfl
#align list.chain_range_succ List.chain_range_succ
#align list.range_add List.range_add
#align list.iota_eq_reverse_range' List.iota_eq_reverse_range'
#align list.length_iota List.length_iota
theorem pairwise_gt_iota (n : ℕ) : Pairwise (· > ·) (iota n) := by
simpa only [iota_eq_reverse_range', pairwise_reverse] using pairwise_lt_range' 1 n
#align list.pairwise_gt_iota List.pairwise_gt_iota
theorem nodup_iota (n : ℕ) : Nodup (iota n) :=
(pairwise_gt_iota n).imp _root_.ne_of_gt
#align list.nodup_iota List.nodup_iota
#align list.mem_iota List.mem_iota
#align list.reverse_range' List.reverse_range'
def finRange (n : ℕ) : List (Fin n) :=
(range n).pmap Fin.mk fun _ => List.mem_range.1
#align list.fin_range List.finRange
@[simp]
theorem finRange_zero : finRange 0 = [] :=
rfl
#align list.fin_range_zero List.finRange_zero
@[simp]
theorem mem_finRange {n : ℕ} (a : Fin n) : a ∈ finRange n :=
mem_pmap.2
⟨a.1, mem_range.2 a.2, by
cases a
rfl⟩
#align list.mem_fin_range List.mem_finRange
theorem nodup_finRange (n : ℕ) : (finRange n).Nodup :=
(Pairwise.pmap (nodup_range n) _) fun _ _ _ _ => @Fin.ne_of_vne _ ⟨_, _⟩ ⟨_, _⟩
#align list.nodup_fin_range List.nodup_finRange
@[simp]
theorem length_finRange (n : ℕ) : (finRange n).length = n := by
rw [finRange, length_pmap, length_range]
#align list.length_fin_range List.length_finRange
@[simp]
| Mathlib/Data/List/Range.lean | 164 | 165 | theorem finRange_eq_nil {n : ℕ} : finRange n = [] ↔ n = 0 := by |
rw [← length_eq_zero, length_finRange]
|
import Mathlib.CategoryTheory.Monoidal.Mon_
import Mathlib.CategoryTheory.Monoidal.Braided.Opposite
import Mathlib.CategoryTheory.Monoidal.Transport
import Mathlib.CategoryTheory.Monoidal.CoherenceLemmas
import Mathlib.CategoryTheory.Limits.Shapes.Terminal
universe v₁ v₂ u₁ u₂ u
open CategoryTheory MonoidalCategory
variable (C : Type u₁) [Category.{v₁} C] [MonoidalCategory.{v₁} C]
structure Comon_ where
X : C
counit : X ⟶ 𝟙_ C
comul : X ⟶ X ⊗ X
counit_comul : comul ≫ (counit ▷ X) = (λ_ X).inv := by aesop_cat
comul_counit : comul ≫ (X ◁ counit) = (ρ_ X).inv := by aesop_cat
comul_assoc : comul ≫ (X ◁ comul) ≫ (α_ X X X).inv = comul ≫ (comul ▷ X) := by aesop_cat
attribute [reassoc (attr := simp)] Comon_.counit_comul Comon_.comul_counit
attribute [reassoc (attr := simp)] Comon_.comul_assoc
namespace Comon_
@[simps]
def trivial : Comon_ C where
X := 𝟙_ C
counit := 𝟙 _
comul := (λ_ _).inv
comul_assoc := by coherence
counit_comul := by coherence
comul_counit := by coherence
instance : Inhabited (Comon_ C) :=
⟨trivial C⟩
variable {C}
variable {M : Comon_ C}
@[reassoc (attr := simp)]
theorem counit_comul_hom {Z : C} (f : M.X ⟶ Z) : M.comul ≫ (M.counit ⊗ f) = f ≫ (λ_ Z).inv := by
rw [leftUnitor_inv_naturality, tensorHom_def, counit_comul_assoc]
@[reassoc (attr := simp)]
theorem comul_counit_hom {Z : C} (f : M.X ⟶ Z) : M.comul ≫ (f ⊗ M.counit) = f ≫ (ρ_ Z).inv := by
rw [rightUnitor_inv_naturality, tensorHom_def', comul_counit_assoc]
@[reassoc (attr := simp)] theorem comul_assoc_flip :
M.comul ≫ (M.comul ▷ M.X) ≫ (α_ M.X M.X M.X).hom = M.comul ≫ (M.X ◁ M.comul) := by
simp [← comul_assoc_assoc]
@[ext]
structure Hom (M N : Comon_ C) where
hom : M.X ⟶ N.X
hom_counit : hom ≫ N.counit = M.counit := by aesop_cat
hom_comul : hom ≫ N.comul = M.comul ≫ (hom ⊗ hom) := by aesop_cat
attribute [reassoc (attr := simp)] Hom.hom_counit Hom.hom_comul
@[simps]
def id (M : Comon_ C) : Hom M M where
hom := 𝟙 M.X
instance homInhabited (M : Comon_ C) : Inhabited (Hom M M) :=
⟨id M⟩
@[simps]
def comp {M N O : Comon_ C} (f : Hom M N) (g : Hom N O) : Hom M O where
hom := f.hom ≫ g.hom
instance : Category (Comon_ C) where
Hom M N := Hom M N
id := id
comp f g := comp f g
@[ext] lemma ext {X Y : Comon_ C} {f g : X ⟶ Y} (w : f.hom = g.hom) : f = g := Hom.ext _ _ w
@[simp] theorem id_hom' (M : Comon_ C) : (𝟙 M : Hom M M).hom = 𝟙 M.X := rfl
@[simp]
theorem comp_hom' {M N K : Comon_ C} (f : M ⟶ N) (g : N ⟶ K) : (f ≫ g).hom = f.hom ≫ g.hom :=
rfl
section
variable (C)
@[simps]
def forget : Comon_ C ⥤ C where
obj A := A.X
map f := f.hom
end
instance forget_faithful : (@forget C _ _).Faithful where
instance {A B : Comon_ C} (f : A ⟶ B) [e : IsIso ((forget C).map f)] : IsIso f.hom := e
instance : (forget C).ReflectsIsomorphisms where
reflects f e :=
⟨⟨{ hom := inv f.hom }, by aesop_cat⟩⟩
@[simps]
def mkIso {M N : Comon_ C} (f : M.X ≅ N.X) (f_counit : f.hom ≫ N.counit = M.counit := by aesop_cat)
(f_comul : f.hom ≫ N.comul = M.comul ≫ (f.hom ⊗ f.hom) := by aesop_cat) : M ≅ N where
hom :=
{ hom := f.hom
hom_counit := f_counit
hom_comul := f_comul }
inv :=
{ hom := f.inv
hom_counit := by rw [← f_counit]; simp
hom_comul := by
rw [← cancel_epi f.hom]
slice_rhs 1 2 => rw [f_comul]
simp }
instance uniqueHomToTrivial (A : Comon_ C) : Unique (A ⟶ trivial C) where
default :=
{ hom := A.counit
hom_counit := by dsimp; simp
hom_comul := by dsimp; simp [A.comul_counit, unitors_inv_equal] }
uniq f := by
ext; simp
rw [← Category.comp_id f.hom]
erw [f.hom_counit]
open CategoryTheory.Limits
instance : HasTerminal (Comon_ C) :=
hasTerminal_of_unique (trivial C)
open Opposite
variable (C)
@[simps] def Comon_ToMon_OpOp_obj' (A : Comon_ C) : Mon_ (Cᵒᵖ) where
X := op A.X
one := A.counit.op
mul := A.comul.op
one_mul := by
rw [← op_whiskerRight, ← op_comp, counit_comul]
rfl
mul_one := by
rw [← op_whiskerLeft, ← op_comp, comul_counit]
rfl
mul_assoc := by
rw [← op_inv_associator, ← op_whiskerRight, ← op_comp, ← op_whiskerLeft, ← op_comp,
← comul_assoc, op_comp, op_comp_assoc]
rfl
@[simps] def Comon_ToMon_OpOp : Comon_ C ⥤ (Mon_ (Cᵒᵖ))ᵒᵖ where
obj A := op (Comon_ToMon_OpOp_obj' C A)
map := fun f => op <|
{ hom := f.hom.op
one_hom := by apply Quiver.Hom.unop_inj; simp
mul_hom := by apply Quiver.Hom.unop_inj; simp [op_tensorHom] }
@[simps] def Mon_OpOpToComon_obj' (A : (Mon_ (Cᵒᵖ))) : Comon_ C where
X := unop A.X
counit := A.one.unop
comul := A.mul.unop
counit_comul := by rw [← unop_whiskerRight, ← unop_comp, Mon_.one_mul]; rfl
comul_counit := by rw [← unop_whiskerLeft, ← unop_comp, Mon_.mul_one]; rfl
comul_assoc := by
rw [← unop_whiskerRight, ← unop_comp, ← unop_whiskerLeft, ← unop_comp_assoc, Mon_.mul_assoc]
rfl
@[simps]
def Mon_OpOpToComon_ : (Mon_ (Cᵒᵖ))ᵒᵖ ⥤ Comon_ C where
obj A := Mon_OpOpToComon_obj' C (unop A)
map := fun f =>
{ hom := f.unop.hom.unop
hom_counit := by apply Quiver.Hom.op_inj; simp
hom_comul := by apply Quiver.Hom.op_inj; simp [op_tensorHom] }
@[simps]
def Comon_EquivMon_OpOp : Comon_ C ≌ (Mon_ (Cᵒᵖ))ᵒᵖ :=
{ functor := Comon_ToMon_OpOp C
inverse := Mon_OpOpToComon_ C
unitIso := NatIso.ofComponents (fun _ => Iso.refl _)
counitIso := NatIso.ofComponents (fun _ => Iso.refl _) }
instance [BraidedCategory C] : MonoidalCategory (Comon_ C) :=
Monoidal.transport (Comon_EquivMon_OpOp C).symm
variable [BraidedCategory C]
theorem tensorObj_X (A B : Comon_ C) : (A ⊗ B).X = A.X ⊗ B.X := rfl
theorem tensorObj_counit (A B : Comon_ C) : (A ⊗ B).counit = (A.counit ⊗ B.counit) ≫ (λ_ _).hom :=
rfl
theorem tensorObj_comul' (A B : Comon_ C) :
(A ⊗ B).comul =
(A.comul ⊗ B.comul) ≫ (tensor_μ Cᵒᵖ (op A.X, op B.X) (op A.X, op B.X)).unop := by
rfl
| Mathlib/CategoryTheory/Monoidal/Comon_.lean | 270 | 277 | theorem tensorObj_comul (A B : Comon_ C) :
(A ⊗ B).comul = (A.comul ⊗ B.comul) ≫ tensor_μ C (A.X, A.X) (B.X, B.X) := by |
rw [tensorObj_comul']
congr
simp only [tensor_μ, unop_tensorObj, unop_op]
apply Quiver.Hom.unop_inj
dsimp [op_tensorObj, op_associator]
rw [Category.assoc, Category.assoc, Category.assoc]
|
import Mathlib.Algebra.Star.Basic
import Mathlib.Algebra.Order.CauSeq.Completion
#align_import data.real.basic from "leanprover-community/mathlib"@"cb42593171ba005beaaf4549fcfe0dece9ada4c9"
assert_not_exists Finset
assert_not_exists Module
assert_not_exists Submonoid
assert_not_exists FloorRing
structure Real where ofCauchy ::
cauchy : CauSeq.Completion.Cauchy (abs : ℚ → ℚ)
#align real Real
@[inherit_doc]
notation "ℝ" => Real
-- Porting note: unknown attribute
-- attribute [pp_using_anonymous_constructor] Real
namespace Real
open CauSeq CauSeq.Completion
variable {x y : ℝ}
theorem ext_cauchy_iff : ∀ {x y : Real}, x = y ↔ x.cauchy = y.cauchy
| ⟨a⟩, ⟨b⟩ => by rw [ofCauchy.injEq]
#align real.ext_cauchy_iff Real.ext_cauchy_iff
theorem ext_cauchy {x y : Real} : x.cauchy = y.cauchy → x = y :=
ext_cauchy_iff.2
#align real.ext_cauchy Real.ext_cauchy
def equivCauchy : ℝ ≃ CauSeq.Completion.Cauchy (abs : ℚ → ℚ) :=
⟨Real.cauchy, Real.ofCauchy, fun ⟨_⟩ => rfl, fun _ => rfl⟩
set_option linter.uppercaseLean3 false in
#align real.equiv_Cauchy Real.equivCauchy
-- irreducible doesn't work for instances: https://github.com/leanprover-community/lean/issues/511
private irreducible_def zero : ℝ :=
⟨0⟩
private irreducible_def one : ℝ :=
⟨1⟩
private irreducible_def add : ℝ → ℝ → ℝ
| ⟨a⟩, ⟨b⟩ => ⟨a + b⟩
private irreducible_def neg : ℝ → ℝ
| ⟨a⟩ => ⟨-a⟩
private irreducible_def mul : ℝ → ℝ → ℝ
| ⟨a⟩, ⟨b⟩ => ⟨a * b⟩
private noncomputable irreducible_def inv' : ℝ → ℝ
| ⟨a⟩ => ⟨a⁻¹⟩
instance : Zero ℝ :=
⟨zero⟩
instance : One ℝ :=
⟨one⟩
instance : Add ℝ :=
⟨add⟩
instance : Neg ℝ :=
⟨neg⟩
instance : Mul ℝ :=
⟨mul⟩
instance : Sub ℝ :=
⟨fun a b => a + -b⟩
noncomputable instance : Inv ℝ :=
⟨inv'⟩
theorem ofCauchy_zero : (⟨0⟩ : ℝ) = 0 :=
zero_def.symm
#align real.of_cauchy_zero Real.ofCauchy_zero
theorem ofCauchy_one : (⟨1⟩ : ℝ) = 1 :=
one_def.symm
#align real.of_cauchy_one Real.ofCauchy_one
theorem ofCauchy_add (a b) : (⟨a + b⟩ : ℝ) = ⟨a⟩ + ⟨b⟩ :=
(add_def _ _).symm
#align real.of_cauchy_add Real.ofCauchy_add
theorem ofCauchy_neg (a) : (⟨-a⟩ : ℝ) = -⟨a⟩ :=
(neg_def _).symm
#align real.of_cauchy_neg Real.ofCauchy_neg
theorem ofCauchy_sub (a b) : (⟨a - b⟩ : ℝ) = ⟨a⟩ - ⟨b⟩ := by
rw [sub_eq_add_neg, ofCauchy_add, ofCauchy_neg]
rfl
#align real.of_cauchy_sub Real.ofCauchy_sub
theorem ofCauchy_mul (a b) : (⟨a * b⟩ : ℝ) = ⟨a⟩ * ⟨b⟩ :=
(mul_def _ _).symm
#align real.of_cauchy_mul Real.ofCauchy_mul
theorem ofCauchy_inv {f} : (⟨f⁻¹⟩ : ℝ) = ⟨f⟩⁻¹ :=
show _ = inv' _ by rw [inv']
#align real.of_cauchy_inv Real.ofCauchy_inv
theorem cauchy_zero : (0 : ℝ).cauchy = 0 :=
show zero.cauchy = 0 by rw [zero_def]
#align real.cauchy_zero Real.cauchy_zero
theorem cauchy_one : (1 : ℝ).cauchy = 1 :=
show one.cauchy = 1 by rw [one_def]
#align real.cauchy_one Real.cauchy_one
theorem cauchy_add : ∀ a b, (a + b : ℝ).cauchy = a.cauchy + b.cauchy
| ⟨a⟩, ⟨b⟩ => show (add _ _).cauchy = _ by rw [add_def]
#align real.cauchy_add Real.cauchy_add
theorem cauchy_neg : ∀ a, (-a : ℝ).cauchy = -a.cauchy
| ⟨a⟩ => show (neg _).cauchy = _ by rw [neg_def]
#align real.cauchy_neg Real.cauchy_neg
theorem cauchy_mul : ∀ a b, (a * b : ℝ).cauchy = a.cauchy * b.cauchy
| ⟨a⟩, ⟨b⟩ => show (mul _ _).cauchy = _ by rw [mul_def]
#align real.cauchy_mul Real.cauchy_mul
theorem cauchy_sub : ∀ a b, (a - b : ℝ).cauchy = a.cauchy - b.cauchy
| ⟨a⟩, ⟨b⟩ => by
rw [sub_eq_add_neg, ← cauchy_neg, ← cauchy_add]
rfl
#align real.cauchy_sub Real.cauchy_sub
theorem cauchy_inv : ∀ f, (f⁻¹ : ℝ).cauchy = f.cauchy⁻¹
| ⟨f⟩ => show (inv' _).cauchy = _ by rw [inv']
#align real.cauchy_inv Real.cauchy_inv
instance instNatCast : NatCast ℝ where natCast n := ⟨n⟩
instance instIntCast : IntCast ℝ where intCast z := ⟨z⟩
instance instNNRatCast : NNRatCast ℝ where nnratCast q := ⟨q⟩
instance instRatCast : RatCast ℝ where ratCast q := ⟨q⟩
lemma ofCauchy_natCast (n : ℕ) : (⟨n⟩ : ℝ) = n := rfl
lemma ofCauchy_intCast (z : ℤ) : (⟨z⟩ : ℝ) = z := rfl
lemma ofCauchy_nnratCast (q : ℚ≥0) : (⟨q⟩ : ℝ) = q := rfl
lemma ofCauchy_ratCast (q : ℚ) : (⟨q⟩ : ℝ) = q := rfl
#align real.of_cauchy_nat_cast Real.ofCauchy_natCast
#align real.of_cauchy_int_cast Real.ofCauchy_intCast
#align real.of_cauchy_rat_cast Real.ofCauchy_ratCast
lemma cauchy_natCast (n : ℕ) : (n : ℝ).cauchy = n := rfl
lemma cauchy_intCast (z : ℤ) : (z : ℝ).cauchy = z := rfl
lemma cauchy_nnratCast (q : ℚ≥0) : (q : ℝ).cauchy = q := rfl
lemma cauchy_ratCast (q : ℚ) : (q : ℝ).cauchy = q := rfl
#align real.cauchy_nat_cast Real.cauchy_natCast
#align real.cauchy_int_cast Real.cauchy_intCast
#align real.cauchy_rat_cast Real.cauchy_ratCast
instance commRing : CommRing ℝ where
natCast n := ⟨n⟩
intCast z := ⟨z⟩
zero := (0 : ℝ)
one := (1 : ℝ)
mul := (· * ·)
add := (· + ·)
neg := @Neg.neg ℝ _
sub := @Sub.sub ℝ _
npow := @npowRec ℝ ⟨1⟩ ⟨(· * ·)⟩
nsmul := @nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩
zsmul := @zsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩ ⟨@Neg.neg ℝ _⟩ (@nsmulRec ℝ ⟨0⟩ ⟨(· + ·)⟩)
add_zero a := by apply ext_cauchy; simp [cauchy_add, cauchy_zero]
zero_add a := by apply ext_cauchy; simp [cauchy_add, cauchy_zero]
add_comm a b := by apply ext_cauchy; simp only [cauchy_add, add_comm]
add_assoc a b c := by apply ext_cauchy; simp only [cauchy_add, add_assoc]
mul_zero a := by apply ext_cauchy; simp [cauchy_mul, cauchy_zero]
zero_mul a := by apply ext_cauchy; simp [cauchy_mul, cauchy_zero]
mul_one a := by apply ext_cauchy; simp [cauchy_mul, cauchy_one]
one_mul a := by apply ext_cauchy; simp [cauchy_mul, cauchy_one]
mul_comm a b := by apply ext_cauchy; simp only [cauchy_mul, mul_comm]
mul_assoc a b c := by apply ext_cauchy; simp only [cauchy_mul, mul_assoc]
left_distrib a b c := by apply ext_cauchy; simp only [cauchy_add, cauchy_mul, mul_add]
right_distrib a b c := by apply ext_cauchy; simp only [cauchy_add, cauchy_mul, add_mul]
add_left_neg a := by apply ext_cauchy; simp [cauchy_add, cauchy_neg, cauchy_zero]
natCast_zero := by apply ext_cauchy; simp [cauchy_zero]
natCast_succ n := by apply ext_cauchy; simp [cauchy_one, cauchy_add]
intCast_negSucc z := by apply ext_cauchy; simp [cauchy_neg, cauchy_natCast]
@[simps]
def ringEquivCauchy : ℝ ≃+* CauSeq.Completion.Cauchy (abs : ℚ → ℚ) :=
{ equivCauchy with
toFun := cauchy
invFun := ofCauchy
map_add' := cauchy_add
map_mul' := cauchy_mul }
set_option linter.uppercaseLean3 false in
#align real.ring_equiv_Cauchy Real.ringEquivCauchy
set_option linter.uppercaseLean3 false in
#align real.ring_equiv_Cauchy_apply Real.ringEquivCauchy_apply
set_option linter.uppercaseLean3 false in
#align real.ring_equiv_Cauchy_symm_apply_cauchy Real.ringEquivCauchy_symm_apply_cauchy
instance instRing : Ring ℝ := by infer_instance
instance : CommSemiring ℝ := by infer_instance
instance semiring : Semiring ℝ := by infer_instance
instance : CommMonoidWithZero ℝ := by infer_instance
instance : MonoidWithZero ℝ := by infer_instance
instance : AddCommGroup ℝ := by infer_instance
instance : AddGroup ℝ := by infer_instance
instance : AddCommMonoid ℝ := by infer_instance
instance : AddMonoid ℝ := by infer_instance
instance : AddLeftCancelSemigroup ℝ := by infer_instance
instance : AddRightCancelSemigroup ℝ := by infer_instance
instance : AddCommSemigroup ℝ := by infer_instance
instance : AddSemigroup ℝ := by infer_instance
instance : CommMonoid ℝ := by infer_instance
instance : Monoid ℝ := by infer_instance
instance : CommSemigroup ℝ := by infer_instance
instance : Semigroup ℝ := by infer_instance
instance : Inhabited ℝ :=
⟨0⟩
instance : StarRing ℝ :=
starRingOfComm
instance : TrivialStar ℝ :=
⟨fun _ => rfl⟩
def mk (x : CauSeq ℚ abs) : ℝ :=
⟨CauSeq.Completion.mk x⟩
#align real.mk Real.mk
theorem mk_eq {f g : CauSeq ℚ abs} : mk f = mk g ↔ f ≈ g :=
ext_cauchy_iff.trans CauSeq.Completion.mk_eq
#align real.mk_eq Real.mk_eq
private irreducible_def lt : ℝ → ℝ → Prop
| ⟨x⟩, ⟨y⟩ =>
(Quotient.liftOn₂ x y (· < ·)) fun _ _ _ _ hf hg =>
propext <|
⟨fun h => lt_of_eq_of_lt (Setoid.symm hf) (lt_of_lt_of_eq h hg), fun h =>
lt_of_eq_of_lt hf (lt_of_lt_of_eq h (Setoid.symm hg))⟩
instance : LT ℝ :=
⟨lt⟩
theorem lt_cauchy {f g} : (⟨⟦f⟧⟩ : ℝ) < ⟨⟦g⟧⟩ ↔ f < g :=
show lt _ _ ↔ _ by rw [lt_def]; rfl
#align real.lt_cauchy Real.lt_cauchy
@[simp]
theorem mk_lt {f g : CauSeq ℚ abs} : mk f < mk g ↔ f < g :=
lt_cauchy
#align real.mk_lt Real.mk_lt
theorem mk_zero : mk 0 = 0 := by rw [← ofCauchy_zero]; rfl
#align real.mk_zero Real.mk_zero
| Mathlib/Data/Real/Basic.lean | 319 | 319 | theorem mk_one : mk 1 = 1 := by | rw [← ofCauchy_one]; rfl
|
import Mathlib.Analysis.InnerProductSpace.Projection
import Mathlib.Geometry.Euclidean.PerpBisector
import Mathlib.Algebra.QuadraticDiscriminant
#align_import geometry.euclidean.basic from "leanprover-community/mathlib"@"2de9c37fa71dde2f1c6feff19876dd6a7b1519f0"
noncomputable section
open scoped Classical
open RealInnerProductSpace
namespace EuclideanGeometry
variable {V : Type*} {P : Type*}
variable [NormedAddCommGroup V] [InnerProductSpace ℝ V] [MetricSpace P]
variable [NormedAddTorsor V P]
theorem dist_left_midpoint_eq_dist_right_midpoint (p1 p2 : P) :
dist p1 (midpoint ℝ p1 p2) = dist p2 (midpoint ℝ p1 p2) := by
rw [dist_left_midpoint (𝕜 := ℝ) p1 p2, dist_right_midpoint (𝕜 := ℝ) p1 p2]
#align euclidean_geometry.dist_left_midpoint_eq_dist_right_midpoint EuclideanGeometry.dist_left_midpoint_eq_dist_right_midpoint
theorem inner_weightedVSub {ι₁ : Type*} {s₁ : Finset ι₁} {w₁ : ι₁ → ℝ} (p₁ : ι₁ → P)
(h₁ : ∑ i ∈ s₁, w₁ i = 0) {ι₂ : Type*} {s₂ : Finset ι₂} {w₂ : ι₂ → ℝ} (p₂ : ι₂ → P)
(h₂ : ∑ i ∈ s₂, w₂ i = 0) :
⟪s₁.weightedVSub p₁ w₁, s₂.weightedVSub p₂ w₂⟫ =
(-∑ i₁ ∈ s₁, ∑ i₂ ∈ s₂, w₁ i₁ * w₂ i₂ * (dist (p₁ i₁) (p₂ i₂) * dist (p₁ i₁) (p₂ i₂))) /
2 := by
rw [Finset.weightedVSub_apply, Finset.weightedVSub_apply,
inner_sum_smul_sum_smul_of_sum_eq_zero _ h₁ _ h₂]
simp_rw [vsub_sub_vsub_cancel_right]
rcongr (i₁ i₂) <;> rw [dist_eq_norm_vsub V (p₁ i₁) (p₂ i₂)]
#align euclidean_geometry.inner_weighted_vsub EuclideanGeometry.inner_weightedVSub
| Mathlib/Geometry/Euclidean/Basic.lean | 93 | 104 | theorem dist_affineCombination {ι : Type*} {s : Finset ι} {w₁ w₂ : ι → ℝ} (p : ι → P)
(h₁ : ∑ i ∈ s, w₁ i = 1) (h₂ : ∑ i ∈ s, w₂ i = 1) : by
have a₁ := s.affineCombination ℝ p w₁
have a₂ := s.affineCombination ℝ p w₂
exact dist a₁ a₂ * dist a₁ a₂ = (-∑ i₁ ∈ s, ∑ i₂ ∈ s,
(w₁ - w₂) i₁ * (w₁ - w₂) i₂ * (dist (p i₁) (p i₂) * dist (p i₁) (p i₂))) / 2 := by |
dsimp only
rw [dist_eq_norm_vsub V (s.affineCombination ℝ p w₁) (s.affineCombination ℝ p w₂), ←
@inner_self_eq_norm_mul_norm ℝ, Finset.affineCombination_vsub]
have h : (∑ i ∈ s, (w₁ - w₂) i) = 0 := by
simp_rw [Pi.sub_apply, Finset.sum_sub_distrib, h₁, h₂, sub_self]
exact inner_weightedVSub p h p h
|
import Mathlib.Init.Data.List.Basic
import Mathlib.Algebra.Group.Basic
import Mathlib.Algebra.Group.Nat
import Mathlib.Data.Nat.Defs
import Mathlib.Tactic.Convert
import Mathlib.Tactic.GeneralizeProofs
import Mathlib.Tactic.Says
#align_import data.nat.bits from "leanprover-community/mathlib"@"d012cd09a9b256d870751284dd6a29882b0be105"
-- Once we're in the `Nat` namespace, `xor` will inconveniently resolve to `Nat.xor`.
local notation "bxor" => _root_.xor
-- As this file is all about `bit0` and `bit1`,
-- we turn off the deprecated linter for the whole file.
set_option linter.deprecated false
namespace Nat
universe u
variable {m n : ℕ}
def boddDiv2 : ℕ → Bool × ℕ
| 0 => (false, 0)
| succ n =>
match boddDiv2 n with
| (false, m) => (true, m)
| (true, m) => (false, succ m)
#align nat.bodd_div2 Nat.boddDiv2
def div2 (n : ℕ) : ℕ := (boddDiv2 n).2
#align nat.div2 Nat.div2
def bodd (n : ℕ) : Bool := (boddDiv2 n).1
#align nat.bodd Nat.bodd
@[simp] lemma bodd_zero : bodd 0 = false := rfl
#align nat.bodd_zero Nat.bodd_zero
lemma bodd_one : bodd 1 = true := rfl
#align nat.bodd_one Nat.bodd_one
lemma bodd_two : bodd 2 = false := rfl
#align nat.bodd_two Nat.bodd_two
@[simp]
lemma bodd_succ (n : ℕ) : bodd (succ n) = not (bodd n) := by
simp only [bodd, boddDiv2]
let ⟨b,m⟩ := boddDiv2 n
cases b <;> rfl
#align nat.bodd_succ Nat.bodd_succ
@[simp]
lemma bodd_add (m n : ℕ) : bodd (m + n) = bxor (bodd m) (bodd n) := by
induction n
case zero => simp
case succ n ih => simp [← Nat.add_assoc, Bool.xor_not, ih]
#align nat.bodd_add Nat.bodd_add
@[simp]
lemma bodd_mul (m n : ℕ) : bodd (m * n) = (bodd m && bodd n) := by
induction' n with n IH
· simp
· simp only [mul_succ, bodd_add, IH, bodd_succ]
cases bodd m <;> cases bodd n <;> rfl
#align nat.bodd_mul Nat.bodd_mul
lemma mod_two_of_bodd (n : ℕ) : n % 2 = cond (bodd n) 1 0 := by
have := congr_arg bodd (mod_add_div n 2)
simp? [not] at this says
simp only [bodd_add, bodd_mul, bodd_succ, not, bodd_zero, Bool.false_and, Bool.bne_false]
at this
have _ : ∀ b, and false b = false := by
intro b
cases b <;> rfl
have _ : ∀ b, bxor b false = b := by
intro b
cases b <;> rfl
rw [← this]
cases' mod_two_eq_zero_or_one n with h h <;> rw [h] <;> rfl
#align nat.mod_two_of_bodd Nat.mod_two_of_bodd
@[simp] lemma div2_zero : div2 0 = 0 := rfl
#align nat.div2_zero Nat.div2_zero
lemma div2_one : div2 1 = 0 := rfl
#align nat.div2_one Nat.div2_one
lemma div2_two : div2 2 = 1 := rfl
#align nat.div2_two Nat.div2_two
@[simp]
lemma div2_succ (n : ℕ) : div2 (succ n) = cond (bodd n) (succ (div2 n)) (div2 n) := by
simp only [bodd, boddDiv2, div2]
rcases boddDiv2 n with ⟨_|_, _⟩ <;> simp
#align nat.div2_succ Nat.div2_succ
attribute [local simp] Nat.add_comm Nat.add_assoc Nat.add_left_comm Nat.mul_comm Nat.mul_assoc
lemma bodd_add_div2 : ∀ n, cond (bodd n) 1 0 + 2 * div2 n = n
| 0 => rfl
| succ n => by
simp only [bodd_succ, Bool.cond_not, div2_succ, Nat.mul_comm]
refine Eq.trans ?_ (congr_arg succ (bodd_add_div2 n))
cases bodd n
· simp
· simp; omega
#align nat.bodd_add_div2 Nat.bodd_add_div2
lemma div2_val (n) : div2 n = n / 2 := by
refine Nat.eq_of_mul_eq_mul_left (by decide)
(Nat.add_left_cancel (Eq.trans ?_ (Nat.mod_add_div n 2).symm))
rw [mod_two_of_bodd, bodd_add_div2]
#align nat.div2_val Nat.div2_val
def bit (b : Bool) : ℕ → ℕ := cond b bit1 bit0
#align nat.bit Nat.bit
lemma bit0_val (n : Nat) : bit0 n = 2 * n :=
calc
n + n = 0 + n + n := by rw [Nat.zero_add]
_ = n * 2 := rfl
_ = 2 * n := Nat.mul_comm _ _
#align nat.bit0_val Nat.bit0_val
lemma bit1_val (n : Nat) : bit1 n = 2 * n + 1 := congr_arg succ (bit0_val _)
#align nat.bit1_val Nat.bit1_val
lemma bit_val (b n) : bit b n = 2 * n + cond b 1 0 := by
cases b
· apply bit0_val
· apply bit1_val
#align nat.bit_val Nat.bit_val
lemma bit_decomp (n : Nat) : bit (bodd n) (div2 n) = n :=
(bit_val _ _).trans <| (Nat.add_comm _ _).trans <| bodd_add_div2 _
#align nat.bit_decomp Nat.bit_decomp
def bitCasesOn {C : Nat → Sort u} (n) (h : ∀ b n, C (bit b n)) : C n := bit_decomp n ▸ h _ _
#align nat.bit_cases_on Nat.bitCasesOn
lemma bit_zero : bit false 0 = 0 :=
rfl
#align nat.bit_zero Nat.bit_zero
def shiftLeft' (b : Bool) (m : ℕ) : ℕ → ℕ
| 0 => m
| n + 1 => bit b (shiftLeft' b m n)
#align nat.shiftl' Nat.shiftLeft'
@[simp]
lemma shiftLeft'_false : ∀ n, shiftLeft' false m n = m <<< n
| 0 => rfl
| n + 1 => by
have : 2 * (m * 2^n) = 2^(n+1)*m := by
rw [Nat.mul_comm, Nat.mul_assoc, ← Nat.pow_succ]; simp
simp [shiftLeft_eq, shiftLeft', bit_val, shiftLeft'_false, this]
@[simp] lemma shiftLeft_eq' (m n : Nat) : shiftLeft m n = m <<< n := rfl
@[simp] lemma shiftRight_eq (m n : Nat) : shiftRight m n = m >>> n := rfl
#align nat.test_bit Nat.testBit
lemma binaryRec_decreasing (h : n ≠ 0) : div2 n < n := by
rw [div2_val]
apply (div_lt_iff_lt_mul <| succ_pos 1).2
have := Nat.mul_lt_mul_of_pos_left (lt_succ_self 1)
(lt_of_le_of_ne n.zero_le h.symm)
rwa [Nat.mul_one] at this
def binaryRec {C : Nat → Sort u} (z : C 0) (f : ∀ b n, C n → C (bit b n)) : ∀ n, C n :=
fun n =>
if n0 : n = 0 then by
simp only [n0]
exact z
else by
let n' := div2 n
have _x : bit (bodd n) n' = n := by
apply bit_decomp n
rw [← _x]
exact f (bodd n) n' (binaryRec z f n')
decreasing_by exact binaryRec_decreasing n0
#align nat.binary_rec Nat.binaryRec
def size : ℕ → ℕ :=
binaryRec 0 fun _ _ => succ
#align nat.size Nat.size
def bits : ℕ → List Bool :=
binaryRec [] fun b _ IH => b :: IH
#align nat.bits Nat.bits
#align nat.bitwise Nat.bitwise
#align nat.lor Nat.lor
#align nat.land Nat.land
#align nat.lxor Nat.xor
def ldiff : ℕ → ℕ → ℕ :=
bitwise fun a b => a && not b
#align nat.ldiff Nat.ldiff
@[simp]
lemma binaryRec_zero {C : Nat → Sort u} (z : C 0) (f : ∀ b n, C n → C (bit b n)) :
binaryRec z f 0 = z := by
rw [binaryRec]
rfl
#align nat.binary_rec_zero Nat.binaryRec_zero
lemma bodd_bit (b n) : bodd (bit b n) = b := by
rw [bit_val]
simp only [Nat.mul_comm, Nat.add_comm, bodd_add, bodd_mul, bodd_succ, bodd_zero, Bool.not_false,
Bool.not_true, Bool.and_false, Bool.xor_false]
cases b <;> cases bodd n <;> rfl
#align nat.bodd_bit Nat.bodd_bit
lemma div2_bit (b n) : div2 (bit b n) = n := by
rw [bit_val, div2_val, Nat.add_comm, add_mul_div_left, div_eq_of_lt, Nat.zero_add]
<;> cases b
<;> decide
#align nat.div2_bit Nat.div2_bit
lemma shiftLeft'_add (b m n) : ∀ k, shiftLeft' b m (n + k) = shiftLeft' b (shiftLeft' b m n) k
| 0 => rfl
| k + 1 => congr_arg (bit b) (shiftLeft'_add b m n k)
#align nat.shiftl'_add Nat.shiftLeft'_add
lemma shiftLeft'_sub (b m) : ∀ {n k}, k ≤ n → shiftLeft' b m (n - k) = (shiftLeft' b m n) >>> k
| n, 0, _ => rfl
| n + 1, k + 1, h => by
rw [succ_sub_succ_eq_sub, shiftLeft', Nat.add_comm, shiftRight_add]
simp only [shiftLeft'_sub, Nat.le_of_succ_le_succ h, shiftRight_succ, shiftRight_zero]
simp [← div2_val, div2_bit]
#align nat.shiftl'_sub Nat.shiftLeft'_sub
lemma shiftLeft_sub : ∀ (m : Nat) {n k}, k ≤ n → m <<< (n - k) = (m <<< n) >>> k :=
fun _ _ _ hk => by simp only [← shiftLeft'_false, shiftLeft'_sub false _ hk]
-- Not a `simp` lemma, as later `simp` will be able to prove this.
lemma testBit_bit_zero (b n) : testBit (bit b n) 0 = b := by
rw [testBit, bit]
cases b
· simp [bit0, ← Nat.mul_two]
· simp [bit0, bit1, ← Nat.mul_two]
#align nat.test_bit_zero Nat.testBit_zero
lemma bodd_eq_one_and_ne_zero : ∀ n, bodd n = (1 &&& n != 0)
| 0 => rfl
| 1 => rfl
| n + 2 => by simpa using bodd_eq_one_and_ne_zero n
lemma testBit_bit_succ (m b n) : testBit (bit b n) (succ m) = testBit n m := by
have : bodd (((bit b n) >>> 1) >>> m) = bodd (n >>> m) := by
simp only [shiftRight_eq_div_pow]
simp [← div2_val, div2_bit]
rw [← shiftRight_add, Nat.add_comm] at this
simp only [bodd_eq_one_and_ne_zero] at this
exact this
#align nat.test_bit_succ Nat.testBit_succ
lemma binaryRec_eq {C : Nat → Sort u} {z : C 0} {f : ∀ b n, C n → C (bit b n)}
(h : f false 0 z = z) (b n) : binaryRec z f (bit b n) = f b n (binaryRec z f n) := by
rw [binaryRec]
split_ifs with h'
· generalize binaryRec z f (bit b n) = e
revert e
have bf := bodd_bit b n
have n0 := div2_bit b n
rw [h'] at bf n0
simp only [bodd_zero, div2_zero] at bf n0
subst bf n0
rw [binaryRec_zero]
intros
rw [h, eq_mpr_eq_cast, cast_eq]
· simp only; generalize_proofs h
revert h
rw [bodd_bit, div2_bit]
intros; simp only [eq_mpr_eq_cast, cast_eq]
#align nat.binary_rec_eq Nat.binaryRec_eq
#noalign nat.bitwise_bit_aux
@[simp]
theorem boddDiv2_eq (n : ℕ) : boddDiv2 n = (bodd n, div2 n) := rfl
#align nat.bodd_div2_eq Nat.boddDiv2_eq
@[simp]
theorem bodd_bit0 (n) : bodd (bit0 n) = false :=
bodd_bit false n
#align nat.bodd_bit0 Nat.bodd_bit0
@[simp]
theorem bodd_bit1 (n) : bodd (bit1 n) = true :=
bodd_bit true n
#align nat.bodd_bit1 Nat.bodd_bit1
@[simp]
theorem div2_bit0 (n) : div2 (bit0 n) = n :=
div2_bit false n
#align nat.div2_bit0 Nat.div2_bit0
@[simp]
theorem div2_bit1 (n) : div2 (bit1 n) = n :=
div2_bit true n
#align nat.div2_bit1 Nat.div2_bit1
-- There is no need to prove `bit0_eq_zero : bit0 n = 0 ↔ n = 0`
-- as this is true for any `[Semiring R] [NoZeroDivisors R] [CharZero R]`
-- However the lemmas `bit0_eq_bit0`, `bit1_eq_bit1`, `bit1_eq_one`, `one_eq_bit1`
-- need `[Ring R] [NoZeroDivisors R] [CharZero R]` in general,
-- so we prove `ℕ` specialized versions here.
@[simp]
theorem bit0_eq_bit0 {m n : ℕ} : bit0 m = bit0 n ↔ m = n :=
⟨Nat.bit0_inj, fun h => by subst h; rfl⟩
#align nat.bit0_eq_bit0 Nat.bit0_eq_bit0
@[simp]
theorem bit1_eq_bit1 {m n : ℕ} : bit1 m = bit1 n ↔ m = n :=
⟨Nat.bit1_inj, fun h => by subst h; rfl⟩
#align nat.bit1_eq_bit1 Nat.bit1_eq_bit1
@[simp]
theorem bit1_eq_one {n : ℕ} : bit1 n = 1 ↔ n = 0 :=
⟨@Nat.bit1_inj n 0, fun h => by subst h; rfl⟩
#align nat.bit1_eq_one Nat.bit1_eq_one
@[simp]
theorem one_eq_bit1 {n : ℕ} : 1 = bit1 n ↔ n = 0 :=
⟨fun h => (@Nat.bit1_inj 0 n h).symm, fun h => by subst h; rfl⟩
#align nat.one_eq_bit1 Nat.one_eq_bit1
theorem bit_add : ∀ (b : Bool) (n m : ℕ), bit b (n + m) = bit false n + bit b m
| true, _, _ => (congr_arg (· + 1) <| add_add_add_comm _ _ _ _ : _).trans (add_assoc _ _ _)
| false, _, _ => add_add_add_comm _ _ _ _
#align nat.bit_add Nat.bit_add
theorem bit_add' : ∀ (b : Bool) (n m : ℕ), bit b (n + m) = bit b n + bit false m
| true, _, _ => (congr_arg (· + 1) <| add_add_add_comm _ _ _ _ : _).trans (add_right_comm _ _ _)
| false, _, _ => add_add_add_comm _ _ _ _
#align nat.bit_add' Nat.bit_add'
theorem bit_ne_zero (b) {n} (h : n ≠ 0) : bit b n ≠ 0 := by
cases b <;> [exact Nat.bit0_ne_zero h; exact Nat.bit1_ne_zero _]
#align nat.bit_ne_zero Nat.bit_ne_zero
theorem bit0_mod_two : bit0 n % 2 = 0 := by
rw [Nat.mod_two_of_bodd]
simp
#align nat.bit0_mod_two Nat.bit0_mod_two
theorem bit1_mod_two : bit1 n % 2 = 1 := by
rw [Nat.mod_two_of_bodd]
simp
#align nat.bit1_mod_two Nat.bit1_mod_two
theorem pos_of_bit0_pos {n : ℕ} (h : 0 < bit0 n) : 0 < n := by
cases n
· cases h
· apply succ_pos
#align nat.pos_of_bit0_pos Nat.pos_of_bit0_pos
@[simp]
theorem bitCasesOn_bit {C : ℕ → Sort u} (H : ∀ b n, C (bit b n)) (b : Bool) (n : ℕ) :
bitCasesOn (bit b n) H = H b n :=
eq_of_heq <| (eq_rec_heq _ _).trans <| by rw [bodd_bit, div2_bit]
#align nat.bit_cases_on_bit Nat.bitCasesOn_bit
@[simp]
theorem bitCasesOn_bit0 {C : ℕ → Sort u} (H : ∀ b n, C (bit b n)) (n : ℕ) :
bitCasesOn (bit0 n) H = H false n :=
bitCasesOn_bit H false n
#align nat.bit_cases_on_bit0 Nat.bitCasesOn_bit0
@[simp]
theorem bitCasesOn_bit1 {C : ℕ → Sort u} (H : ∀ b n, C (bit b n)) (n : ℕ) :
bitCasesOn (bit1 n) H = H true n :=
bitCasesOn_bit H true n
#align nat.bit_cases_on_bit1 Nat.bitCasesOn_bit1
theorem bit_cases_on_injective {C : ℕ → Sort u} :
Function.Injective fun H : ∀ b n, C (bit b n) => fun n => bitCasesOn n H := by
intro H₁ H₂ h
ext b n
simpa only [bitCasesOn_bit] using congr_fun h (bit b n)
#align nat.bit_cases_on_injective Nat.bit_cases_on_injective
@[simp]
theorem bit_cases_on_inj {C : ℕ → Sort u} (H₁ H₂ : ∀ b n, C (bit b n)) :
((fun n => bitCasesOn n H₁) = fun n => bitCasesOn n H₂) ↔ H₁ = H₂ :=
bit_cases_on_injective.eq_iff
#align nat.bit_cases_on_inj Nat.bit_cases_on_inj
protected theorem bit0_eq_zero {n : ℕ} : bit0 n = 0 ↔ n = 0 :=
⟨Nat.eq_zero_of_add_eq_zero_left, fun h => by simp [h]⟩
#align nat.bit0_eq_zero Nat.bit0_eq_zero
theorem bit_eq_zero_iff {n : ℕ} {b : Bool} : bit b n = 0 ↔ n = 0 ∧ b = false := by
constructor
· cases b <;> simp [Nat.bit, Nat.bit0_eq_zero, Nat.bit1_ne_zero]
· rintro ⟨rfl, rfl⟩
rfl
#align nat.bit_eq_zero_iff Nat.bit_eq_zero_iff
protected lemma bit0_le (h : n ≤ m) : bit0 n ≤ bit0 m :=
add_le_add h h
#align nat.bit0_le Nat.bit0_le
protected lemma bit1_le {n m : ℕ} (h : n ≤ m) : bit1 n ≤ bit1 m :=
succ_le_succ (add_le_add h h)
#align nat.bit1_le Nat.bit1_le
lemma bit_le : ∀ (b : Bool) {m n : ℕ}, m ≤ n → bit b m ≤ bit b n
| true, _, _, h => Nat.bit1_le h
| false, _, _, h => Nat.bit0_le h
#align nat.bit_le Nat.bit_le
lemma bit0_le_bit : ∀ (b) {m n : ℕ}, m ≤ n → bit0 m ≤ bit b n
| true, _, _, h => le_of_lt <| Nat.bit0_lt_bit1 h
| false, _, _, h => Nat.bit0_le h
#align nat.bit0_le_bit Nat.bit0_le_bit
lemma bit_le_bit1 : ∀ (b) {m n : ℕ}, m ≤ n → bit b m ≤ bit1 n
| false, _, _, h => le_of_lt <| Nat.bit0_lt_bit1 h
| true, _, _, h => Nat.bit1_le h
#align nat.bit_le_bit1 Nat.bit_le_bit1
lemma bit_lt_bit0 : ∀ (b) {m n : ℕ}, m < n → bit b m < bit0 n
| true, _, _, h => Nat.bit1_lt_bit0 h
| false, _, _, h => Nat.bit0_lt h
#align nat.bit_lt_bit0 Nat.bit_lt_bit0
protected lemma bit0_lt_bit0 : bit0 m < bit0 n ↔ m < n := by unfold bit0; omega
lemma bit_lt_bit (a b) (h : m < n) : bit a m < bit b n :=
lt_of_lt_of_le (bit_lt_bit0 _ h) (bit0_le_bit _ (le_refl _))
#align nat.bit_lt_bit Nat.bit_lt_bit
@[simp]
lemma bit0_le_bit1_iff : bit0 m ≤ bit1 n ↔ m ≤ n := by
refine ⟨fun h ↦ ?_, fun h ↦ le_of_lt (Nat.bit0_lt_bit1 h)⟩
rwa [← Nat.lt_succ_iff, n.bit1_eq_succ_bit0, ← n.bit0_succ_eq, Nat.bit0_lt_bit0, Nat.lt_succ_iff]
at h
#align nat.bit0_le_bit1_iff Nat.bit0_le_bit1_iff
@[simp]
lemma bit0_lt_bit1_iff : bit0 m < bit1 n ↔ m ≤ n :=
⟨fun h => bit0_le_bit1_iff.1 (le_of_lt h), Nat.bit0_lt_bit1⟩
#align nat.bit0_lt_bit1_iff Nat.bit0_lt_bit1_iff
@[simp]
lemma bit1_le_bit0_iff : bit1 m ≤ bit0 n ↔ m < n :=
⟨fun h ↦ by rwa [m.bit1_eq_succ_bit0, Nat.succ_le_iff, Nat.bit0_lt_bit0] at h,
fun h ↦ le_of_lt (Nat.bit1_lt_bit0 h)⟩
#align nat.bit1_le_bit0_iff Nat.bit1_le_bit0_iff
@[simp]
lemma bit1_lt_bit0_iff : bit1 m < bit0 n ↔ m < n :=
⟨fun h ↦ bit1_le_bit0_iff.1 (le_of_lt h), Nat.bit1_lt_bit0⟩
#align nat.bit1_lt_bit0_iff Nat.bit1_lt_bit0_iff
-- Porting note: temporarily porting only needed portions
theorem binaryRec_eq' {C : ℕ → Sort*} {z : C 0} {f : ∀ b n, C n → C (bit b n)} (b n)
(h : f false 0 z = z ∨ (n = 0 → b = true)) :
binaryRec z f (bit b n) = f b n (binaryRec z f n) := by
rw [binaryRec]
split_ifs with h'
· rcases bit_eq_zero_iff.mp h' with ⟨rfl, rfl⟩
rw [binaryRec_zero]
simp only [imp_false, or_false_iff, eq_self_iff_true, not_true] at h
exact h.symm
· dsimp only []
generalize_proofs e
revert e
rw [bodd_bit, div2_bit]
intros
rfl
#align nat.binary_rec_eq' Nat.binaryRec_eq'
@[elab_as_elim]
def binaryRec' {C : ℕ → Sort*} (z : C 0) (f : ∀ b n, (n = 0 → b = true) → C n → C (bit b n)) :
∀ n, C n :=
binaryRec z fun b n ih =>
if h : n = 0 → b = true then f b n h ih
else by
convert z
rw [bit_eq_zero_iff]
simpa using h
#align nat.binary_rec' Nat.binaryRec'
@[elab_as_elim]
def binaryRecFromOne {C : ℕ → Sort*} (z₀ : C 0) (z₁ : C 1) (f : ∀ b n, n ≠ 0 → C n → C (bit b n)) :
∀ n, C n :=
binaryRec' z₀ fun b n h ih =>
if h' : n = 0 then by
rw [h', h h']
exact z₁
else f b n h' ih
#align nat.binary_rec_from_one Nat.binaryRecFromOne
@[simp]
| Mathlib/Data/Nat/Bits.lean | 588 | 588 | theorem zero_bits : bits 0 = [] := by | simp [Nat.bits]
|
import Mathlib.MeasureTheory.OuterMeasure.Basic
open Filter Set
open scoped ENNReal
namespace MeasureTheory
variable {α β F : Type*} [FunLike F (Set α) ℝ≥0∞] [OuterMeasureClass F α] {μ : F} {s t : Set α}
def ae (μ : F) : Filter α :=
.ofCountableUnion (μ · = 0) (fun _S hSc ↦ (measure_sUnion_null_iff hSc).2) fun _t ht _s hs ↦
measure_mono_null hs ht
#align measure_theory.measure.ae MeasureTheory.ae
notation3 "∀ᵐ "(...)" ∂"μ", "r:(scoped p => Filter.Eventually p <| MeasureTheory.ae μ) => r
notation3 "∃ᵐ "(...)" ∂"μ", "r:(scoped P => Filter.Frequently P <| MeasureTheory.ae μ) => r
notation:50 f " =ᵐ[" μ:50 "] " g:50 => Filter.EventuallyEq (MeasureTheory.ae μ) f g
notation:50 f " ≤ᵐ[" μ:50 "] " g:50 => Filter.EventuallyLE (MeasureTheory.ae μ) f g
theorem mem_ae_iff {s : Set α} : s ∈ ae μ ↔ μ sᶜ = 0 :=
Iff.rfl
#align measure_theory.mem_ae_iff MeasureTheory.mem_ae_iff
theorem ae_iff {p : α → Prop} : (∀ᵐ a ∂μ, p a) ↔ μ { a | ¬p a } = 0 :=
Iff.rfl
#align measure_theory.ae_iff MeasureTheory.ae_iff
theorem compl_mem_ae_iff {s : Set α} : sᶜ ∈ ae μ ↔ μ s = 0 := by simp only [mem_ae_iff, compl_compl]
#align measure_theory.compl_mem_ae_iff MeasureTheory.compl_mem_ae_iff
theorem frequently_ae_iff {p : α → Prop} : (∃ᵐ a ∂μ, p a) ↔ μ { a | p a } ≠ 0 :=
not_congr compl_mem_ae_iff
#align measure_theory.frequently_ae_iff MeasureTheory.frequently_ae_iff
theorem frequently_ae_mem_iff {s : Set α} : (∃ᵐ a ∂μ, a ∈ s) ↔ μ s ≠ 0 :=
not_congr compl_mem_ae_iff
#align measure_theory.frequently_ae_mem_iff MeasureTheory.frequently_ae_mem_iff
theorem measure_zero_iff_ae_nmem {s : Set α} : μ s = 0 ↔ ∀ᵐ a ∂μ, a ∉ s :=
compl_mem_ae_iff.symm
#align measure_theory.measure_zero_iff_ae_nmem MeasureTheory.measure_zero_iff_ae_nmem
theorem ae_of_all {p : α → Prop} (μ : F) : (∀ a, p a) → ∀ᵐ a ∂μ, p a :=
eventually_of_forall
#align measure_theory.ae_of_all MeasureTheory.ae_of_all
instance instCountableInterFilter : CountableInterFilter (ae μ) := by
unfold ae; infer_instance
#align measure_theory.measure.ae.countable_Inter_filter MeasureTheory.instCountableInterFilter
theorem ae_all_iff {ι : Sort*} [Countable ι] {p : α → ι → Prop} :
(∀ᵐ a ∂μ, ∀ i, p a i) ↔ ∀ i, ∀ᵐ a ∂μ, p a i :=
eventually_countable_forall
#align measure_theory.ae_all_iff MeasureTheory.ae_all_iff
theorem all_ae_of {ι : Sort*} {p : α → ι → Prop} (hp : ∀ᵐ a ∂μ, ∀ i, p a i) (i : ι) :
∀ᵐ a ∂μ, p a i := by
filter_upwards [hp] with a ha using ha i
lemma ae_iff_of_countable [Countable α] {p : α → Prop} : (∀ᵐ x ∂μ, p x) ↔ ∀ x, μ {x} ≠ 0 → p x := by
rw [ae_iff, measure_null_iff_singleton]
exacts [forall_congr' fun _ ↦ not_imp_comm, Set.to_countable _]
theorem ae_ball_iff {ι : Type*} {S : Set ι} (hS : S.Countable) {p : α → ∀ i ∈ S, Prop} :
(∀ᵐ x ∂μ, ∀ i (hi : i ∈ S), p x i hi) ↔ ∀ i (hi : i ∈ S), ∀ᵐ x ∂μ, p x i hi :=
eventually_countable_ball hS
#align measure_theory.ae_ball_iff MeasureTheory.ae_ball_iff
theorem ae_eq_refl (f : α → β) : f =ᵐ[μ] f :=
EventuallyEq.rfl
#align measure_theory.ae_eq_refl MeasureTheory.ae_eq_refl
theorem ae_eq_symm {f g : α → β} (h : f =ᵐ[μ] g) : g =ᵐ[μ] f :=
h.symm
#align measure_theory.ae_eq_symm MeasureTheory.ae_eq_symm
theorem ae_eq_trans {f g h : α → β} (h₁ : f =ᵐ[μ] g) (h₂ : g =ᵐ[μ] h) : f =ᵐ[μ] h :=
h₁.trans h₂
#align measure_theory.ae_eq_trans MeasureTheory.ae_eq_trans
theorem ae_le_of_ae_lt {β : Type*} [Preorder β] {f g : α → β} (h : ∀ᵐ x ∂μ, f x < g x) :
f ≤ᵐ[μ] g :=
h.mono fun _ ↦ le_of_lt
#align measure_theory.ae_le_of_ae_lt MeasureTheory.ae_le_of_ae_lt
@[simp]
theorem ae_eq_empty : s =ᵐ[μ] (∅ : Set α) ↔ μ s = 0 :=
eventuallyEq_empty.trans <| by simp only [ae_iff, Classical.not_not, setOf_mem_eq]
#align measure_theory.ae_eq_empty MeasureTheory.ae_eq_empty
-- Porting note: The priority should be higher than `eventuallyEq_univ`.
@[simp high]
theorem ae_eq_univ : s =ᵐ[μ] (univ : Set α) ↔ μ sᶜ = 0 :=
eventuallyEq_univ
#align measure_theory.ae_eq_univ MeasureTheory.ae_eq_univ
theorem ae_le_set : s ≤ᵐ[μ] t ↔ μ (s \ t) = 0 :=
calc
s ≤ᵐ[μ] t ↔ ∀ᵐ x ∂μ, x ∈ s → x ∈ t := Iff.rfl
_ ↔ μ (s \ t) = 0 := by simp [ae_iff]; rfl
#align measure_theory.ae_le_set MeasureTheory.ae_le_set
theorem ae_le_set_inter {s' t' : Set α} (h : s ≤ᵐ[μ] t) (h' : s' ≤ᵐ[μ] t') :
(s ∩ s' : Set α) ≤ᵐ[μ] (t ∩ t' : Set α) :=
h.inter h'
#align measure_theory.ae_le_set_inter MeasureTheory.ae_le_set_inter
theorem ae_le_set_union {s' t' : Set α} (h : s ≤ᵐ[μ] t) (h' : s' ≤ᵐ[μ] t') :
(s ∪ s' : Set α) ≤ᵐ[μ] (t ∪ t' : Set α) :=
h.union h'
#align measure_theory.ae_le_set_union MeasureTheory.ae_le_set_union
theorem union_ae_eq_right : (s ∪ t : Set α) =ᵐ[μ] t ↔ μ (s \ t) = 0 := by
simp [eventuallyLE_antisymm_iff, ae_le_set, union_diff_right,
diff_eq_empty.2 Set.subset_union_right]
#align measure_theory.union_ae_eq_right MeasureTheory.union_ae_eq_right
theorem diff_ae_eq_self : (s \ t : Set α) =ᵐ[μ] s ↔ μ (s ∩ t) = 0 := by
simp [eventuallyLE_antisymm_iff, ae_le_set, diff_diff_right, diff_diff,
diff_eq_empty.2 Set.subset_union_right]
#align measure_theory.diff_ae_eq_self MeasureTheory.diff_ae_eq_self
theorem diff_null_ae_eq_self (ht : μ t = 0) : (s \ t : Set α) =ᵐ[μ] s :=
diff_ae_eq_self.mpr (measure_mono_null inter_subset_right ht)
#align measure_theory.diff_null_ae_eq_self MeasureTheory.diff_null_ae_eq_self
theorem ae_eq_set {s t : Set α} : s =ᵐ[μ] t ↔ μ (s \ t) = 0 ∧ μ (t \ s) = 0 := by
simp [eventuallyLE_antisymm_iff, ae_le_set]
#align measure_theory.ae_eq_set MeasureTheory.ae_eq_set
open scoped symmDiff in
@[simp]
theorem measure_symmDiff_eq_zero_iff {s t : Set α} : μ (s ∆ t) = 0 ↔ s =ᵐ[μ] t := by
simp [ae_eq_set, symmDiff_def]
#align measure_theory.measure_symm_diff_eq_zero_iff MeasureTheory.measure_symmDiff_eq_zero_iff
@[simp]
theorem ae_eq_set_compl_compl {s t : Set α} : sᶜ =ᵐ[μ] tᶜ ↔ s =ᵐ[μ] t := by
simp only [← measure_symmDiff_eq_zero_iff, compl_symmDiff_compl]
#align measure_theory.ae_eq_set_compl_compl MeasureTheory.ae_eq_set_compl_compl
theorem ae_eq_set_compl {s t : Set α} : sᶜ =ᵐ[μ] t ↔ s =ᵐ[μ] tᶜ := by
rw [← ae_eq_set_compl_compl, compl_compl]
#align measure_theory.ae_eq_set_compl MeasureTheory.ae_eq_set_compl
theorem ae_eq_set_inter {s' t' : Set α} (h : s =ᵐ[μ] t) (h' : s' =ᵐ[μ] t') :
(s ∩ s' : Set α) =ᵐ[μ] (t ∩ t' : Set α) :=
h.inter h'
#align measure_theory.ae_eq_set_inter MeasureTheory.ae_eq_set_inter
theorem ae_eq_set_union {s' t' : Set α} (h : s =ᵐ[μ] t) (h' : s' =ᵐ[μ] t') :
(s ∪ s' : Set α) =ᵐ[μ] (t ∪ t' : Set α) :=
h.union h'
#align measure_theory.ae_eq_set_union MeasureTheory.ae_eq_set_union
theorem union_ae_eq_univ_of_ae_eq_univ_left (h : s =ᵐ[μ] univ) : (s ∪ t : Set α) =ᵐ[μ] univ :=
(ae_eq_set_union h (ae_eq_refl t)).trans <| by rw [univ_union]
#align measure_theory.union_ae_eq_univ_of_ae_eq_univ_left MeasureTheory.union_ae_eq_univ_of_ae_eq_univ_left
theorem union_ae_eq_univ_of_ae_eq_univ_right (h : t =ᵐ[μ] univ) : (s ∪ t : Set α) =ᵐ[μ] univ := by
convert ae_eq_set_union (ae_eq_refl s) h
rw [union_univ]
#align measure_theory.union_ae_eq_univ_of_ae_eq_univ_right MeasureTheory.union_ae_eq_univ_of_ae_eq_univ_right
theorem union_ae_eq_right_of_ae_eq_empty (h : s =ᵐ[μ] (∅ : Set α)) : (s ∪ t : Set α) =ᵐ[μ] t := by
convert ae_eq_set_union h (ae_eq_refl t)
rw [empty_union]
#align measure_theory.union_ae_eq_right_of_ae_eq_empty MeasureTheory.union_ae_eq_right_of_ae_eq_empty
theorem union_ae_eq_left_of_ae_eq_empty (h : t =ᵐ[μ] (∅ : Set α)) : (s ∪ t : Set α) =ᵐ[μ] s := by
convert ae_eq_set_union (ae_eq_refl s) h
rw [union_empty]
#align measure_theory.union_ae_eq_left_of_ae_eq_empty MeasureTheory.union_ae_eq_left_of_ae_eq_empty
| Mathlib/MeasureTheory/OuterMeasure/AE.lean | 226 | 228 | theorem inter_ae_eq_right_of_ae_eq_univ (h : s =ᵐ[μ] univ) : (s ∩ t : Set α) =ᵐ[μ] t := by |
convert ae_eq_set_inter h (ae_eq_refl t)
rw [univ_inter]
|
import Mathlib.Combinatorics.SimpleGraph.Regularity.Bound
import Mathlib.Combinatorics.SimpleGraph.Regularity.Equitabilise
import Mathlib.Combinatorics.SimpleGraph.Regularity.Uniform
#align_import combinatorics.simple_graph.regularity.chunk from "leanprover-community/mathlib"@"bf7ef0e83e5b7e6c1169e97f055e58a2e4e9d52d"
open Finpartition Finset Fintype Rel Nat
open scoped SzemerediRegularity.Positivity
namespace SzemerediRegularity
variable {α : Type*} [Fintype α] [DecidableEq α] {P : Finpartition (univ : Finset α)}
(hP : P.IsEquipartition) (G : SimpleGraph α) [DecidableRel G.Adj] (ε : ℝ) {U : Finset α}
(hU : U ∈ P.parts) (V : Finset α)
local notation3 "m" => (card α / stepBound P.parts.card : ℕ)
noncomputable def chunk : Finpartition U :=
if hUcard : U.card = m * 4 ^ P.parts.card + (card α / P.parts.card - m * 4 ^ P.parts.card) then
(atomise U <| P.nonuniformWitnesses G ε U).equitabilise <| card_aux₁ hUcard
else (atomise U <| P.nonuniformWitnesses G ε U).equitabilise <| card_aux₂ hP hU hUcard
#align szemeredi_regularity.chunk SzemerediRegularity.chunk
-- `hP` and `hU` are used to get that `U` has size
-- `m * 4 ^ P.parts.card + a or m * 4 ^ P.parts.card + a + 1`
noncomputable def star (V : Finset α) : Finset (Finset α) :=
(chunk hP G ε hU).parts.filter (· ⊆ G.nonuniformWitness ε U V)
#align szemeredi_regularity.star SzemerediRegularity.star
theorem biUnion_star_subset_nonuniformWitness :
(star hP G ε hU V).biUnion id ⊆ G.nonuniformWitness ε U V :=
biUnion_subset_iff_forall_subset.2 fun _ hA => (mem_filter.1 hA).2
#align szemeredi_regularity.bUnion_star_subset_nonuniform_witness SzemerediRegularity.biUnion_star_subset_nonuniformWitness
variable {hP G ε hU V} {𝒜 : Finset (Finset α)} {s : Finset α}
theorem star_subset_chunk : star hP G ε hU V ⊆ (chunk hP G ε hU).parts :=
filter_subset _ _
#align szemeredi_regularity.star_subset_chunk SzemerediRegularity.star_subset_chunk
private theorem card_nonuniformWitness_sdiff_biUnion_star (hV : V ∈ P.parts) (hUV : U ≠ V)
(h₂ : ¬G.IsUniform ε U V) :
(G.nonuniformWitness ε U V \ (star hP G ε hU V).biUnion id).card ≤
2 ^ (P.parts.card - 1) * m := by
have hX : G.nonuniformWitness ε U V ∈ P.nonuniformWitnesses G ε U :=
nonuniformWitness_mem_nonuniformWitnesses h₂ hV hUV
have q : G.nonuniformWitness ε U V \ (star hP G ε hU V).biUnion id ⊆
((atomise U <| P.nonuniformWitnesses G ε U).parts.filter fun B =>
B ⊆ G.nonuniformWitness ε U V ∧ B.Nonempty).biUnion
fun B => B \ ((chunk hP G ε hU).parts.filter (· ⊆ B)).biUnion id := by
intro x hx
rw [← biUnion_filter_atomise hX (G.nonuniformWitness_subset h₂), star, mem_sdiff,
mem_biUnion] at hx
simp only [not_exists, mem_biUnion, and_imp, exists_prop, mem_filter,
not_and, mem_sdiff, id, mem_sdiff] at hx ⊢
obtain ⟨⟨B, hB₁, hB₂⟩, hx⟩ := hx
exact ⟨B, hB₁, hB₂, fun A hA AB => hx A hA <| AB.trans hB₁.2.1⟩
apply (card_le_card q).trans (card_biUnion_le.trans _)
trans ∑ _i in (atomise U <| P.nonuniformWitnesses G ε U).parts.filter fun B =>
B ⊆ G.nonuniformWitness ε U V ∧ B.Nonempty, m
· suffices ∀ B ∈ (atomise U <| P.nonuniformWitnesses G ε U).parts,
(B \ ((chunk hP G ε hU).parts.filter (· ⊆ B)).biUnion id).card ≤ m by
exact sum_le_sum fun B hB => this B <| filter_subset _ _ hB
intro B hB
unfold chunk
split_ifs with h₁
· convert card_parts_equitabilise_subset_le _ (card_aux₁ h₁) hB
· convert card_parts_equitabilise_subset_le _ (card_aux₂ hP hU h₁) hB
rw [sum_const]
refine mul_le_mul_right' ?_ _
have t := card_filter_atomise_le_two_pow (s := U) hX
refine t.trans (pow_le_pow_right (by norm_num) <| tsub_le_tsub_right ?_ _)
exact card_image_le.trans (card_le_card <| filter_subset _ _)
private theorem one_sub_eps_mul_card_nonuniformWitness_le_card_star (hV : V ∈ P.parts)
(hUV : U ≠ V) (hunif : ¬G.IsUniform ε U V) (hPε : ↑100 ≤ ↑4 ^ P.parts.card * ε ^ 5)
(hε₁ : ε ≤ 1) :
(1 - ε / 10) * (G.nonuniformWitness ε U V).card ≤ ((star hP G ε hU V).biUnion id).card := by
have hP₁ : 0 < P.parts.card := Finset.card_pos.2 ⟨_, hU⟩
have : (↑2 ^ P.parts.card : ℝ) * m / (U.card * ε) ≤ ε / 10 := by
rw [← div_div, div_le_iff']
swap
· sz_positivity
refine le_of_mul_le_mul_left ?_ (pow_pos zero_lt_two P.parts.card)
calc
↑2 ^ P.parts.card * ((↑2 ^ P.parts.card * m : ℝ) / U.card) =
((2 : ℝ) * 2) ^ P.parts.card * m / U.card := by
rw [mul_pow, ← mul_div_assoc, mul_assoc]
_ = ↑4 ^ P.parts.card * m / U.card := by norm_num
_ ≤ 1 := div_le_one_of_le (pow_mul_m_le_card_part hP hU) (cast_nonneg _)
_ ≤ ↑2 ^ P.parts.card * ε ^ 2 / 10 := by
refine (one_le_sq_iff <| by positivity).1 ?_
rw [div_pow, mul_pow, pow_right_comm, ← pow_mul ε,
one_le_div (sq_pos_of_ne_zero <| by norm_num)]
calc
(↑10 ^ 2) = 100 := by norm_num
_ ≤ ↑4 ^ P.parts.card * ε ^ 5 := hPε
_ ≤ ↑4 ^ P.parts.card * ε ^ 4 :=
(mul_le_mul_of_nonneg_left (pow_le_pow_of_le_one (by sz_positivity) hε₁ <| le_succ _)
(by positivity))
_ = (↑2 ^ 2) ^ P.parts.card * ε ^ (2 * 2) := by norm_num
_ = ↑2 ^ P.parts.card * (ε * (ε / 10)) := by rw [mul_div_assoc, sq, mul_div_assoc]
calc
(↑1 - ε / 10) * (G.nonuniformWitness ε U V).card ≤
(↑1 - ↑2 ^ P.parts.card * m / (U.card * ε)) * (G.nonuniformWitness ε U V).card :=
mul_le_mul_of_nonneg_right (sub_le_sub_left this _) (cast_nonneg _)
_ = (G.nonuniformWitness ε U V).card -
↑2 ^ P.parts.card * m / (U.card * ε) * (G.nonuniformWitness ε U V).card := by
rw [sub_mul, one_mul]
_ ≤ (G.nonuniformWitness ε U V).card - ↑2 ^ (P.parts.card - 1) * m := by
refine sub_le_sub_left ?_ _
have : (2 : ℝ) ^ P.parts.card = ↑2 ^ (P.parts.card - 1) * 2 := by
rw [← _root_.pow_succ, tsub_add_cancel_of_le (succ_le_iff.2 hP₁)]
rw [← mul_div_right_comm, this, mul_right_comm _ (2 : ℝ), mul_assoc, le_div_iff]
· refine mul_le_mul_of_nonneg_left ?_ (by positivity)
exact (G.le_card_nonuniformWitness hunif).trans
(le_mul_of_one_le_left (cast_nonneg _) one_le_two)
have := Finset.card_pos.mpr (P.nonempty_of_mem_parts hU)
sz_positivity
_ ≤ ((star hP G ε hU V).biUnion id).card := by
rw [sub_le_comm, ←
cast_sub (card_le_card <| biUnion_star_subset_nonuniformWitness hP G ε hU V), ←
card_sdiff (biUnion_star_subset_nonuniformWitness hP G ε hU V)]
exact mod_cast card_nonuniformWitness_sdiff_biUnion_star hV hUV hunif
| Mathlib/Combinatorics/SimpleGraph/Regularity/Chunk.lean | 180 | 185 | theorem card_chunk (hm : m ≠ 0) : (chunk hP G ε hU).parts.card = 4 ^ P.parts.card := by |
unfold chunk
split_ifs
· rw [card_parts_equitabilise _ _ hm, tsub_add_cancel_of_le]
exact le_of_lt a_add_one_le_four_pow_parts_card
· rw [card_parts_equitabilise _ _ hm, tsub_add_cancel_of_le a_add_one_le_four_pow_parts_card]
|
import Mathlib.Algebra.CharP.Invertible
import Mathlib.Data.Real.Sqrt
import Mathlib.Tactic.Polyrith
#align_import algebra.star.chsh from "leanprover-community/mathlib"@"31c24aa72e7b3e5ed97a8412470e904f82b81004"
universe u
--@[nolint has_nonempty_instance] Porting note(#5171): linter not ported yet
structure IsCHSHTuple {R} [Monoid R] [StarMul R] (A₀ A₁ B₀ B₁ : R) : Prop where
A₀_inv : A₀ ^ 2 = 1
A₁_inv : A₁ ^ 2 = 1
B₀_inv : B₀ ^ 2 = 1
B₁_inv : B₁ ^ 2 = 1
A₀_sa : star A₀ = A₀
A₁_sa : star A₁ = A₁
B₀_sa : star B₀ = B₀
B₁_sa : star B₁ = B₁
A₀B₀_commutes : A₀ * B₀ = B₀ * A₀
A₀B₁_commutes : A₀ * B₁ = B₁ * A₀
A₁B₀_commutes : A₁ * B₀ = B₀ * A₁
A₁B₁_commutes : A₁ * B₁ = B₁ * A₁
set_option linter.uppercaseLean3 false in
#align is_CHSH_tuple IsCHSHTuple
variable {R : Type u}
theorem CHSH_id [CommRing R] {A₀ A₁ B₀ B₁ : R} (A₀_inv : A₀ ^ 2 = 1) (A₁_inv : A₁ ^ 2 = 1)
(B₀_inv : B₀ ^ 2 = 1) (B₁_inv : B₁ ^ 2 = 1) :
(2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁) * (2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁) =
4 * (2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁) := by
-- polyrith suggests:
linear_combination
(2 * B₀ * B₁ + 2) * A₀_inv + (B₀ ^ 2 - 2 * B₀ * B₁ + B₁ ^ 2) * A₁_inv +
(A₀ ^ 2 + 2 * A₀ * A₁ + 1) * B₀_inv +
(A₀ ^ 2 - 2 * A₀ * A₁ + 1) * B₁_inv
set_option linter.uppercaseLean3 false in
#align CHSH_id CHSH_id
| Mathlib/Algebra/Star/CHSH.lean | 121 | 138 | theorem CHSH_inequality_of_comm [OrderedCommRing R] [StarRing R] [StarOrderedRing R] [Algebra ℝ R]
[OrderedSMul ℝ R] (A₀ A₁ B₀ B₁ : R) (T : IsCHSHTuple A₀ A₁ B₀ B₁) :
A₀ * B₀ + A₀ * B₁ + A₁ * B₀ - A₁ * B₁ ≤ 2 := by |
let P := 2 - A₀ * B₀ - A₀ * B₁ - A₁ * B₀ + A₁ * B₁
have i₁ : 0 ≤ P := by
have idem : P * P = 4 * P := CHSH_id T.A₀_inv T.A₁_inv T.B₀_inv T.B₁_inv
have idem' : P = (1 / 4 : ℝ) • (P * P) := by
have h : 4 * P = (4 : ℝ) • P := by simp [Algebra.smul_def]
rw [idem, h, ← mul_smul]
norm_num
have sa : star P = P := by
dsimp [P]
simp only [star_add, star_sub, star_mul, star_ofNat, star_one, T.A₀_sa, T.A₁_sa, T.B₀_sa,
T.B₁_sa, mul_comm B₀, mul_comm B₁]
simpa only [← idem', sa]
using smul_nonneg (by norm_num : (0 : ℝ) ≤ 1 / 4) (star_mul_self_nonneg P)
apply le_of_sub_nonneg
simpa only [sub_add_eq_sub_sub, ← sub_add] using i₁
|
import Mathlib.Analysis.NormedSpace.Multilinear.Basic
import Mathlib.Analysis.NormedSpace.Units
import Mathlib.Analysis.NormedSpace.OperatorNorm.Completeness
import Mathlib.Analysis.NormedSpace.OperatorNorm.Mul
#align_import analysis.normed_space.bounded_linear_maps from "leanprover-community/mathlib"@"ce11c3c2a285bbe6937e26d9792fda4e51f3fe1a"
noncomputable section
open Topology
open Filter (Tendsto)
open Metric ContinuousLinearMap
variable {𝕜 : Type*} [NontriviallyNormedField 𝕜] {E : Type*} [NormedAddCommGroup E]
[NormedSpace 𝕜 E] {F : Type*} [NormedAddCommGroup F] [NormedSpace 𝕜 F] {G : Type*}
[NormedAddCommGroup G] [NormedSpace 𝕜 G]
structure IsBoundedLinearMap (𝕜 : Type*) [NormedField 𝕜] {E : Type*} [NormedAddCommGroup E]
[NormedSpace 𝕜 E] {F : Type*} [NormedAddCommGroup F] [NormedSpace 𝕜 F] (f : E → F) extends
IsLinearMap 𝕜 f : Prop where
bound : ∃ M, 0 < M ∧ ∀ x : E, ‖f x‖ ≤ M * ‖x‖
#align is_bounded_linear_map IsBoundedLinearMap
theorem IsLinearMap.with_bound {f : E → F} (hf : IsLinearMap 𝕜 f) (M : ℝ)
(h : ∀ x : E, ‖f x‖ ≤ M * ‖x‖) : IsBoundedLinearMap 𝕜 f :=
⟨hf,
by_cases
(fun (this : M ≤ 0) =>
⟨1, zero_lt_one, fun x =>
(h x).trans <| mul_le_mul_of_nonneg_right (this.trans zero_le_one) (norm_nonneg x)⟩)
fun (this : ¬M ≤ 0) => ⟨M, lt_of_not_ge this, h⟩⟩
#align is_linear_map.with_bound IsLinearMap.with_bound
theorem ContinuousLinearMap.isBoundedLinearMap (f : E →L[𝕜] F) : IsBoundedLinearMap 𝕜 f :=
{ f.toLinearMap.isLinear with bound := f.bound }
#align continuous_linear_map.is_bounded_linear_map ContinuousLinearMap.isBoundedLinearMap
section
variable {ι : Type*} [Fintype ι]
theorem isBoundedLinearMap_prod_multilinear {E : ι → Type*} [∀ i, NormedAddCommGroup (E i)]
[∀ i, NormedSpace 𝕜 (E i)] :
IsBoundedLinearMap 𝕜 fun p : ContinuousMultilinearMap 𝕜 E F × ContinuousMultilinearMap 𝕜 E G =>
p.1.prod p.2 where
map_add p₁ p₂ := by ext : 1; rfl
map_smul c p := by ext : 1; rfl
bound := by
refine ⟨1, zero_lt_one, fun p ↦ ?_⟩
rw [one_mul]
apply ContinuousMultilinearMap.opNorm_le_bound _ (norm_nonneg _) _
intro m
rw [ContinuousMultilinearMap.prod_apply, norm_prod_le_iff]
constructor
· exact (p.1.le_opNorm m).trans (mul_le_mul_of_nonneg_right (norm_fst_le p) <| by positivity)
· exact (p.2.le_opNorm m).trans (mul_le_mul_of_nonneg_right (norm_snd_le p) <| by positivity)
#align is_bounded_linear_map_prod_multilinear isBoundedLinearMap_prod_multilinear
| Mathlib/Analysis/NormedSpace/BoundedLinearMaps.lean | 236 | 254 | theorem isBoundedLinearMap_continuousMultilinearMap_comp_linear (g : G →L[𝕜] E) :
IsBoundedLinearMap 𝕜 fun f : ContinuousMultilinearMap 𝕜 (fun _ : ι => E) F =>
f.compContinuousLinearMap fun _ => g := by |
refine
IsLinearMap.with_bound
⟨fun f₁ f₂ => by ext; rfl,
fun c f => by ext; rfl⟩
(‖g‖ ^ Fintype.card ι) fun f => ?_
apply ContinuousMultilinearMap.opNorm_le_bound _ _ _
· apply_rules [mul_nonneg, pow_nonneg, norm_nonneg]
intro m
calc
‖f (g ∘ m)‖ ≤ ‖f‖ * ∏ i, ‖g (m i)‖ := f.le_opNorm _
_ ≤ ‖f‖ * ∏ i, ‖g‖ * ‖m i‖ := by
apply mul_le_mul_of_nonneg_left _ (norm_nonneg _)
exact Finset.prod_le_prod (fun i _ => norm_nonneg _) fun i _ => g.le_opNorm _
_ = ‖g‖ ^ Fintype.card ι * ‖f‖ * ∏ i, ‖m i‖ := by
simp only [Finset.prod_mul_distrib, Finset.prod_const, Finset.card_univ]
ring
|
import Mathlib.CategoryTheory.Monoidal.Category
import Mathlib.CategoryTheory.Adjunction.FullyFaithful
import Mathlib.CategoryTheory.Products.Basic
#align_import category_theory.monoidal.functor from "leanprover-community/mathlib"@"3d7987cda72abc473c7cdbbb075170e9ac620042"
open CategoryTheory
universe v₁ v₂ v₃ u₁ u₂ u₃
open CategoryTheory.Category
open CategoryTheory.Functor
namespace CategoryTheory
section
open MonoidalCategory
variable (C : Type u₁) [Category.{v₁} C] [MonoidalCategory.{v₁} C] (D : Type u₂) [Category.{v₂} D]
[MonoidalCategory.{v₂} D]
-- The direction of `left_unitality` and `right_unitality` as simp lemmas may look strange:
-- remember the rule of thumb that component indices of natural transformations
-- "weigh more" than structural maps.
-- (However by this argument `associativity` is currently stated backwards!)
structure LaxMonoidalFunctor extends C ⥤ D where
ε : 𝟙_ D ⟶ obj (𝟙_ C)
μ : ∀ X Y : C, obj X ⊗ obj Y ⟶ obj (X ⊗ Y)
μ_natural_left :
∀ {X Y : C} (f : X ⟶ Y) (X' : C),
map f ▷ obj X' ≫ μ Y X' = μ X X' ≫ map (f ▷ X') := by
aesop_cat
μ_natural_right :
∀ {X Y : C} (X' : C) (f : X ⟶ Y) ,
obj X' ◁ map f ≫ μ X' Y = μ X' X ≫ map (X' ◁ f) := by
aesop_cat
associativity :
∀ X Y Z : C,
μ X Y ▷ obj Z ≫ μ (X ⊗ Y) Z ≫ map (α_ X Y Z).hom =
(α_ (obj X) (obj Y) (obj Z)).hom ≫ obj X ◁ μ Y Z ≫ μ X (Y ⊗ Z) := by
aesop_cat
-- unitality
left_unitality : ∀ X : C, (λ_ (obj X)).hom = ε ▷ obj X ≫ μ (𝟙_ C) X ≫ map (λ_ X).hom := by
aesop_cat
right_unitality : ∀ X : C, (ρ_ (obj X)).hom = obj X ◁ ε ≫ μ X (𝟙_ C) ≫ map (ρ_ X).hom := by
aesop_cat
#align category_theory.lax_monoidal_functor CategoryTheory.LaxMonoidalFunctor
-- Porting note (#11215): TODO: remove this configuration and use the default configuration.
-- We keep this to be consistent with Lean 3.
-- See also `initialize_simps_projections MonoidalFunctor` below.
-- This may require waiting on https://github.com/leanprover-community/mathlib4/pull/2936
initialize_simps_projections LaxMonoidalFunctor (+toFunctor, -obj, -map)
attribute [reassoc (attr := simp)] LaxMonoidalFunctor.μ_natural_left
attribute [reassoc (attr := simp)] LaxMonoidalFunctor.μ_natural_right
attribute [simp] LaxMonoidalFunctor.left_unitality
attribute [simp] LaxMonoidalFunctor.right_unitality
attribute [reassoc (attr := simp)] LaxMonoidalFunctor.associativity
-- When `rewrite_search` lands, add @[search] attributes to
-- LaxMonoidalFunctor.μ_natural LaxMonoidalFunctor.left_unitality
-- LaxMonoidalFunctor.right_unitality LaxMonoidalFunctor.associativity
section
variable {C D}
@[reassoc (attr := simp)]
theorem LaxMonoidalFunctor.μ_natural (F : LaxMonoidalFunctor C D) {X Y X' Y' : C}
(f : X ⟶ Y) (g : X' ⟶ Y') :
(F.map f ⊗ F.map g) ≫ F.μ Y Y' = F.μ X X' ≫ F.map (f ⊗ g) := by
simp [tensorHom_def]
@[simps]
def LaxMonoidalFunctor.ofTensorHom (F : C ⥤ D)
(ε : 𝟙_ D ⟶ F.obj (𝟙_ C))
(μ : ∀ X Y : C, F.obj X ⊗ F.obj Y ⟶ F.obj (X ⊗ Y))
(μ_natural :
∀ {X Y X' Y' : C} (f : X ⟶ Y) (g : X' ⟶ Y'),
(F.map f ⊗ F.map g) ≫ μ Y Y' = μ X X' ≫ F.map (f ⊗ g) := by
aesop_cat)
(associativity :
∀ X Y Z : C,
(μ X Y ⊗ 𝟙 (F.obj Z)) ≫ μ (X ⊗ Y) Z ≫ F.map (α_ X Y Z).hom =
(α_ (F.obj X) (F.obj Y) (F.obj Z)).hom ≫ (𝟙 (F.obj X) ⊗ μ Y Z) ≫ μ X (Y ⊗ Z) := by
aesop_cat)
(left_unitality :
∀ X : C, (λ_ (F.obj X)).hom = (ε ⊗ 𝟙 (F.obj X)) ≫ μ (𝟙_ C) X ≫ F.map (λ_ X).hom := by
aesop_cat)
(right_unitality :
∀ X : C, (ρ_ (F.obj X)).hom = (𝟙 (F.obj X) ⊗ ε) ≫ μ X (𝟙_ C) ≫ F.map (ρ_ X).hom := by
aesop_cat) :
LaxMonoidalFunctor C D where
obj := F.obj
map := F.map
map_id := F.map_id
map_comp := F.map_comp
ε := ε
μ := μ
μ_natural_left := fun f X' => by
simp_rw [← tensorHom_id, ← F.map_id, μ_natural]
μ_natural_right := fun X' f => by
simp_rw [← id_tensorHom, ← F.map_id, μ_natural]
associativity := fun X Y Z => by
simp_rw [← tensorHom_id, ← id_tensorHom, associativity]
left_unitality := fun X => by
simp_rw [← tensorHom_id, left_unitality]
right_unitality := fun X => by
simp_rw [← id_tensorHom, right_unitality]
@[reassoc (attr := simp)]
theorem LaxMonoidalFunctor.left_unitality_inv (F : LaxMonoidalFunctor C D) (X : C) :
(λ_ (F.obj X)).inv ≫ F.ε ▷ F.obj X ≫ F.μ (𝟙_ C) X = F.map (λ_ X).inv := by
rw [Iso.inv_comp_eq, F.left_unitality, Category.assoc, Category.assoc, ← F.toFunctor.map_comp,
Iso.hom_inv_id, F.toFunctor.map_id, comp_id]
#align category_theory.lax_monoidal_functor.left_unitality_inv CategoryTheory.LaxMonoidalFunctor.left_unitality_inv
@[reassoc (attr := simp)]
theorem LaxMonoidalFunctor.right_unitality_inv (F : LaxMonoidalFunctor C D) (X : C) :
(ρ_ (F.obj X)).inv ≫ F.obj X ◁ F.ε ≫ F.μ X (𝟙_ C) = F.map (ρ_ X).inv := by
rw [Iso.inv_comp_eq, F.right_unitality, Category.assoc, Category.assoc, ← F.toFunctor.map_comp,
Iso.hom_inv_id, F.toFunctor.map_id, comp_id]
#align category_theory.lax_monoidal_functor.right_unitality_inv CategoryTheory.LaxMonoidalFunctor.right_unitality_inv
@[reassoc (attr := simp)]
theorem LaxMonoidalFunctor.associativity_inv (F : LaxMonoidalFunctor C D) (X Y Z : C) :
F.obj X ◁ F.μ Y Z ≫ F.μ X (Y ⊗ Z) ≫ F.map (α_ X Y Z).inv =
(α_ (F.obj X) (F.obj Y) (F.obj Z)).inv ≫ F.μ X Y ▷ F.obj Z ≫ F.μ (X ⊗ Y) Z := by
rw [Iso.eq_inv_comp, ← F.associativity_assoc, ← F.toFunctor.map_comp, Iso.hom_inv_id,
F.toFunctor.map_id, comp_id]
#align category_theory.lax_monoidal_functor.associativity_inv CategoryTheory.LaxMonoidalFunctor.associativity_inv
end
structure OplaxMonoidalFunctor extends C ⥤ D where
η : obj (𝟙_ C) ⟶ 𝟙_ D
δ : ∀ X Y : C, obj (X ⊗ Y) ⟶ obj X ⊗ obj Y
δ_natural_left :
∀ {X Y : C} (f : X ⟶ Y) (X' : C),
δ X X' ≫ map f ▷ obj X' = map (f ▷ X') ≫ δ Y X' := by
aesop_cat
δ_natural_right :
∀ {X Y : C} (X' : C) (f : X ⟶ Y) ,
δ X' X ≫ obj X' ◁ map f = map (X' ◁ f) ≫ δ X' Y := by
aesop_cat
associativity :
∀ X Y Z : C,
δ (X ⊗ Y) Z ≫ δ X Y ▷ obj Z ≫ (α_ (obj X) (obj Y) (obj Z)).hom =
map (α_ X Y Z).hom ≫ δ X (Y ⊗ Z) ≫ obj X ◁ δ Y Z := by
aesop_cat
-- unitality
left_unitality : ∀ X : C, (λ_ (obj X)).inv = map (λ_ X).inv ≫ δ (𝟙_ C) X ≫ η ▷ obj X := by
aesop_cat
right_unitality : ∀ X : C, (ρ_ (obj X)).inv = map (ρ_ X).inv ≫ δ X (𝟙_ C) ≫ obj X ◁ η := by
aesop_cat
initialize_simps_projections OplaxMonoidalFunctor (+toFunctor, -obj, -map)
attribute [reassoc (attr := simp)] OplaxMonoidalFunctor.δ_natural_left
attribute [reassoc (attr := simp)] OplaxMonoidalFunctor.δ_natural_right
attribute [simp] OplaxMonoidalFunctor.left_unitality
attribute [simp] OplaxMonoidalFunctor.right_unitality
attribute [reassoc (attr := simp)] OplaxMonoidalFunctor.associativity
section
variable {C D}
@[reassoc (attr := simp)]
theorem OplaxMonoidalFunctor.δ_natural (F : OplaxMonoidalFunctor C D) {X Y X' Y' : C}
(f : X ⟶ Y) (g : X' ⟶ Y') :
F.δ X X' ≫ (F.map f ⊗ F.map g) = F.map (f ⊗ g) ≫ F.δ Y Y' := by
simp [tensorHom_def]
@[reassoc (attr := simp)]
theorem OplaxMonoidalFunctor.left_unitality_hom (F : OplaxMonoidalFunctor C D) (X : C) :
F.δ (𝟙_ C) X ≫ F.η ▷ F.obj X ≫ (λ_ (F.obj X)).hom = F.map (λ_ X).hom := by
rw [← Category.assoc, ← Iso.eq_comp_inv, F.left_unitality, ← Category.assoc,
← F.toFunctor.map_comp, Iso.hom_inv_id, F.toFunctor.map_id, id_comp]
@[reassoc (attr := simp)]
theorem OplaxMonoidalFunctor.right_unitality_hom (F : OplaxMonoidalFunctor C D) (X : C) :
F.δ X (𝟙_ C) ≫ F.obj X ◁ F.η ≫ (ρ_ (F.obj X)).hom = F.map (ρ_ X).hom := by
rw [← Category.assoc, ← Iso.eq_comp_inv, F.right_unitality, ← Category.assoc,
← F.toFunctor.map_comp, Iso.hom_inv_id, F.toFunctor.map_id, id_comp]
@[reassoc (attr := simp)]
| Mathlib/CategoryTheory/Monoidal/Functor.lean | 249 | 253 | theorem OplaxMonoidalFunctor.associativity_inv (F : OplaxMonoidalFunctor C D) (X Y Z : C) :
F.δ X (Y ⊗ Z) ≫ F.obj X ◁ F.δ Y Z ≫ (α_ (F.obj X) (F.obj Y) (F.obj Z)).inv =
F.map (α_ X Y Z).inv ≫ F.δ (X ⊗ Y) Z ≫ F.δ X Y ▷ F.obj Z := by |
rw [← Category.assoc, Iso.comp_inv_eq, Category.assoc, Category.assoc, F.associativity,
← Category.assoc, ← F.toFunctor.map_comp, Iso.inv_hom_id, F.toFunctor.map_id, id_comp]
|
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
| Mathlib/MeasureTheory/Integral/Lebesgue.lean | 647 | 650 | 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'
|
import Mathlib.Algebra.BigOperators.Intervals
import Mathlib.Algebra.BigOperators.Ring.List
import Mathlib.Data.Int.ModEq
import Mathlib.Data.Nat.Bits
import Mathlib.Data.Nat.Log
import Mathlib.Data.List.Indexes
import Mathlib.Data.List.Palindrome
import Mathlib.Tactic.IntervalCases
import Mathlib.Tactic.Linarith
import Mathlib.Tactic.Ring
#align_import data.nat.digits from "leanprover-community/mathlib"@"369525b73f229ccd76a6ec0e0e0bf2be57599768"
namespace Nat
variable {n : ℕ}
def digitsAux0 : ℕ → List ℕ
| 0 => []
| n + 1 => [n + 1]
#align nat.digits_aux_0 Nat.digitsAux0
def digitsAux1 (n : ℕ) : List ℕ :=
List.replicate n 1
#align nat.digits_aux_1 Nat.digitsAux1
def digitsAux (b : ℕ) (h : 2 ≤ b) : ℕ → List ℕ
| 0 => []
| n + 1 =>
((n + 1) % b) :: digitsAux b h ((n + 1) / b)
decreasing_by exact Nat.div_lt_self (Nat.succ_pos _) h
#align nat.digits_aux Nat.digitsAux
@[simp]
theorem digitsAux_zero (b : ℕ) (h : 2 ≤ b) : digitsAux b h 0 = [] := by rw [digitsAux]
#align nat.digits_aux_zero Nat.digitsAux_zero
theorem digitsAux_def (b : ℕ) (h : 2 ≤ b) (n : ℕ) (w : 0 < n) :
digitsAux b h n = (n % b) :: digitsAux b h (n / b) := by
cases n
· cases w
· rw [digitsAux]
#align nat.digits_aux_def Nat.digitsAux_def
def digits : ℕ → ℕ → List ℕ
| 0 => digitsAux0
| 1 => digitsAux1
| b + 2 => digitsAux (b + 2) (by norm_num)
#align nat.digits Nat.digits
@[simp]
theorem digits_zero (b : ℕ) : digits b 0 = [] := by
rcases b with (_ | ⟨_ | ⟨_⟩⟩) <;> simp [digits, digitsAux0, digitsAux1]
#align nat.digits_zero Nat.digits_zero
-- @[simp] -- Porting note (#10618): simp can prove this
theorem digits_zero_zero : digits 0 0 = [] :=
rfl
#align nat.digits_zero_zero Nat.digits_zero_zero
@[simp]
theorem digits_zero_succ (n : ℕ) : digits 0 n.succ = [n + 1] :=
rfl
#align nat.digits_zero_succ Nat.digits_zero_succ
theorem digits_zero_succ' : ∀ {n : ℕ}, n ≠ 0 → digits 0 n = [n]
| 0, h => (h rfl).elim
| _ + 1, _ => rfl
#align nat.digits_zero_succ' Nat.digits_zero_succ'
@[simp]
theorem digits_one (n : ℕ) : digits 1 n = List.replicate n 1 :=
rfl
#align nat.digits_one Nat.digits_one
-- @[simp] -- Porting note (#10685): dsimp can prove this
theorem digits_one_succ (n : ℕ) : digits 1 (n + 1) = 1 :: digits 1 n :=
rfl
#align nat.digits_one_succ Nat.digits_one_succ
theorem digits_add_two_add_one (b n : ℕ) :
digits (b + 2) (n + 1) = ((n + 1) % (b + 2)) :: digits (b + 2) ((n + 1) / (b + 2)) := by
simp [digits, digitsAux_def]
#align nat.digits_add_two_add_one Nat.digits_add_two_add_one
@[simp]
lemma digits_of_two_le_of_pos {b : ℕ} (hb : 2 ≤ b) (hn : 0 < n) :
Nat.digits b n = n % b :: Nat.digits b (n / b) := by
rw [Nat.eq_add_of_sub_eq hb rfl, Nat.eq_add_of_sub_eq hn rfl, Nat.digits_add_two_add_one]
theorem digits_def' :
∀ {b : ℕ} (_ : 1 < b) {n : ℕ} (_ : 0 < n), digits b n = (n % b) :: digits b (n / b)
| 0, h => absurd h (by decide)
| 1, h => absurd h (by decide)
| b + 2, _ => digitsAux_def _ (by simp) _
#align nat.digits_def' Nat.digits_def'
@[simp]
theorem digits_of_lt (b x : ℕ) (hx : x ≠ 0) (hxb : x < b) : digits b x = [x] := by
rcases exists_eq_succ_of_ne_zero hx with ⟨x, rfl⟩
rcases Nat.exists_eq_add_of_le' ((Nat.le_add_left 1 x).trans_lt hxb) with ⟨b, rfl⟩
rw [digits_add_two_add_one, div_eq_of_lt hxb, digits_zero, mod_eq_of_lt hxb]
#align nat.digits_of_lt Nat.digits_of_lt
theorem digits_add (b : ℕ) (h : 1 < b) (x y : ℕ) (hxb : x < b) (hxy : x ≠ 0 ∨ y ≠ 0) :
digits b (x + b * y) = x :: digits b y := by
rcases Nat.exists_eq_add_of_le' h with ⟨b, rfl : _ = _ + 2⟩
cases y
· simp [hxb, hxy.resolve_right (absurd rfl)]
dsimp [digits]
rw [digitsAux_def]
· congr
· simp [Nat.add_mod, mod_eq_of_lt hxb]
· simp [add_mul_div_left, div_eq_of_lt hxb]
· apply Nat.succ_pos
#align nat.digits_add Nat.digits_add
-- If we had a function converting a list into a polynomial,
-- and appropriate lemmas about that function,
-- we could rewrite this in terms of that.
def ofDigits {α : Type*} [Semiring α] (b : α) : List ℕ → α
| [] => 0
| h :: t => h + b * ofDigits b t
#align nat.of_digits Nat.ofDigits
theorem ofDigits_eq_foldr {α : Type*} [Semiring α] (b : α) (L : List ℕ) :
ofDigits b L = List.foldr (fun x y => ↑x + b * y) 0 L := by
induction' L with d L ih
· rfl
· dsimp [ofDigits]
rw [ih]
#align nat.of_digits_eq_foldr Nat.ofDigits_eq_foldr
theorem ofDigits_eq_sum_map_with_index_aux (b : ℕ) (l : List ℕ) :
((List.range l.length).zipWith ((fun i a : ℕ => a * b ^ (i + 1))) l).sum =
b * ((List.range l.length).zipWith (fun i a => a * b ^ i) l).sum := by
suffices
(List.range l.length).zipWith (fun i a : ℕ => a * b ^ (i + 1)) l =
(List.range l.length).zipWith (fun i a => b * (a * b ^ i)) l
by simp [this]
congr; ext; simp [pow_succ]; ring
#align nat.of_digits_eq_sum_map_with_index_aux Nat.ofDigits_eq_sum_map_with_index_aux
theorem ofDigits_eq_sum_mapIdx (b : ℕ) (L : List ℕ) :
ofDigits b L = (L.mapIdx fun i a => a * b ^ i).sum := by
rw [List.mapIdx_eq_enum_map, List.enum_eq_zip_range, List.map_uncurry_zip_eq_zipWith,
ofDigits_eq_foldr]
induction' L with hd tl hl
· simp
· simpa [List.range_succ_eq_map, List.zipWith_map_left, ofDigits_eq_sum_map_with_index_aux] using
Or.inl hl
#align nat.of_digits_eq_sum_map_with_index Nat.ofDigits_eq_sum_mapIdx
@[simp]
theorem ofDigits_nil {b : ℕ} : ofDigits b [] = 0 := rfl
@[simp]
theorem ofDigits_singleton {b n : ℕ} : ofDigits b [n] = n := by simp [ofDigits]
#align nat.of_digits_singleton Nat.ofDigits_singleton
@[simp]
theorem ofDigits_one_cons {α : Type*} [Semiring α] (h : ℕ) (L : List ℕ) :
ofDigits (1 : α) (h :: L) = h + ofDigits 1 L := by simp [ofDigits]
#align nat.of_digits_one_cons Nat.ofDigits_one_cons
theorem ofDigits_cons {b hd} {tl : List ℕ} :
ofDigits b (hd :: tl) = hd + b * ofDigits b tl := rfl
theorem ofDigits_append {b : ℕ} {l1 l2 : List ℕ} :
ofDigits b (l1 ++ l2) = ofDigits b l1 + b ^ l1.length * ofDigits b l2 := by
induction' l1 with hd tl IH
· simp [ofDigits]
· rw [ofDigits, List.cons_append, ofDigits, IH, List.length_cons, pow_succ']
ring
#align nat.of_digits_append Nat.ofDigits_append
@[norm_cast]
theorem coe_ofDigits (α : Type*) [Semiring α] (b : ℕ) (L : List ℕ) :
((ofDigits b L : ℕ) : α) = ofDigits (b : α) L := by
induction' L with d L ih
· simp [ofDigits]
· dsimp [ofDigits]; push_cast; rw [ih]
#align nat.coe_of_digits Nat.coe_ofDigits
@[norm_cast]
theorem coe_int_ofDigits (b : ℕ) (L : List ℕ) : ((ofDigits b L : ℕ) : ℤ) = ofDigits (b : ℤ) L := by
induction' L with d L _
· rfl
· dsimp [ofDigits]; push_cast; simp only
#align nat.coe_int_of_digits Nat.coe_int_ofDigits
theorem digits_zero_of_eq_zero {b : ℕ} (h : b ≠ 0) :
∀ {L : List ℕ} (_ : ofDigits b L = 0), ∀ l ∈ L, l = 0
| _ :: _, h0, _, List.Mem.head .. => Nat.eq_zero_of_add_eq_zero_right h0
| _ :: _, h0, _, List.Mem.tail _ hL =>
digits_zero_of_eq_zero h (mul_right_injective₀ h (Nat.eq_zero_of_add_eq_zero_left h0)) _ hL
#align nat.digits_zero_of_eq_zero Nat.digits_zero_of_eq_zero
theorem digits_ofDigits (b : ℕ) (h : 1 < b) (L : List ℕ) (w₁ : ∀ l ∈ L, l < b)
(w₂ : ∀ h : L ≠ [], L.getLast h ≠ 0) : digits b (ofDigits b L) = L := by
induction' L with d L ih
· dsimp [ofDigits]
simp
· dsimp [ofDigits]
replace w₂ := w₂ (by simp)
rw [digits_add b h]
· rw [ih]
· intro l m
apply w₁
exact List.mem_cons_of_mem _ m
· intro h
rw [List.getLast_cons h] at w₂
convert w₂
· exact w₁ d (List.mem_cons_self _ _)
· by_cases h' : L = []
· rcases h' with rfl
left
simpa using w₂
· right
contrapose! w₂
refine digits_zero_of_eq_zero h.ne_bot w₂ _ ?_
rw [List.getLast_cons h']
exact List.getLast_mem h'
#align nat.digits_of_digits Nat.digits_ofDigits
theorem ofDigits_digits (b n : ℕ) : ofDigits b (digits b n) = n := by
cases' b with b
· cases' n with n
· rfl
· change ofDigits 0 [n + 1] = n + 1
dsimp [ofDigits]
· cases' b with b
· induction' n with n ih
· rfl
· rw [Nat.zero_add] at ih ⊢
simp only [ih, add_comm 1, ofDigits_one_cons, Nat.cast_id, digits_one_succ]
· apply Nat.strongInductionOn n _
clear n
intro n h
cases n
· rw [digits_zero]
rfl
· simp only [Nat.succ_eq_add_one, digits_add_two_add_one]
dsimp [ofDigits]
rw [h _ (Nat.div_lt_self' _ b)]
rw [Nat.mod_add_div]
#align nat.of_digits_digits Nat.ofDigits_digits
theorem ofDigits_one (L : List ℕ) : ofDigits 1 L = L.sum := by
induction' L with _ _ ih
· rfl
· simp [ofDigits, List.sum_cons, ih]
#align nat.of_digits_one Nat.ofDigits_one
theorem digits_eq_nil_iff_eq_zero {b n : ℕ} : digits b n = [] ↔ n = 0 := by
constructor
· intro h
have : ofDigits b (digits b n) = ofDigits b [] := by rw [h]
convert this
rw [ofDigits_digits]
· rintro rfl
simp
#align nat.digits_eq_nil_iff_eq_zero Nat.digits_eq_nil_iff_eq_zero
theorem digits_ne_nil_iff_ne_zero {b n : ℕ} : digits b n ≠ [] ↔ n ≠ 0 :=
not_congr digits_eq_nil_iff_eq_zero
#align nat.digits_ne_nil_iff_ne_zero Nat.digits_ne_nil_iff_ne_zero
theorem digits_eq_cons_digits_div {b n : ℕ} (h : 1 < b) (w : n ≠ 0) :
digits b n = (n % b) :: digits b (n / b) := by
rcases b with (_ | _ | b)
· rw [digits_zero_succ' w, Nat.mod_zero, Nat.div_zero, Nat.digits_zero_zero]
· norm_num at h
rcases n with (_ | n)
· norm_num at w
· simp only [digits_add_two_add_one, ne_eq]
#align nat.digits_eq_cons_digits_div Nat.digits_eq_cons_digits_div
theorem digits_getLast {b : ℕ} (m : ℕ) (h : 1 < b) (p q) :
(digits b m).getLast p = (digits b (m / b)).getLast q := by
by_cases hm : m = 0
· simp [hm]
simp only [digits_eq_cons_digits_div h hm]
rw [List.getLast_cons]
#align nat.digits_last Nat.digits_getLast
theorem digits.injective (b : ℕ) : Function.Injective b.digits :=
Function.LeftInverse.injective (ofDigits_digits b)
#align nat.digits.injective Nat.digits.injective
@[simp]
theorem digits_inj_iff {b n m : ℕ} : b.digits n = b.digits m ↔ n = m :=
(digits.injective b).eq_iff
#align nat.digits_inj_iff Nat.digits_inj_iff
theorem digits_len (b n : ℕ) (hb : 1 < b) (hn : n ≠ 0) : (b.digits n).length = b.log n + 1 := by
induction' n using Nat.strong_induction_on with n IH
rw [digits_eq_cons_digits_div hb hn, List.length]
by_cases h : n / b = 0
· have hb0 : b ≠ 0 := (Nat.succ_le_iff.1 hb).ne_bot
simp [h, log_eq_zero_iff, ← Nat.div_eq_zero_iff hb0.bot_lt]
· have : n / b < n := div_lt_self (Nat.pos_of_ne_zero hn) hb
rw [IH _ this h, log_div_base, tsub_add_cancel_of_le]
refine Nat.succ_le_of_lt (log_pos hb ?_)
contrapose! h
exact div_eq_of_lt h
#align nat.digits_len Nat.digits_len
theorem getLast_digit_ne_zero (b : ℕ) {m : ℕ} (hm : m ≠ 0) :
(digits b m).getLast (digits_ne_nil_iff_ne_zero.mpr hm) ≠ 0 := by
rcases b with (_ | _ | b)
· cases m
· cases hm rfl
· simp
· cases m
· cases hm rfl
rename ℕ => m
simp only [zero_add, digits_one, List.getLast_replicate_succ m 1]
exact Nat.one_ne_zero
revert hm
apply Nat.strongInductionOn m
intro n IH hn
by_cases hnb : n < b + 2
· simpa only [digits_of_lt (b + 2) n hn hnb]
· rw [digits_getLast n (le_add_left 2 b)]
refine IH _ (Nat.div_lt_self hn.bot_lt (one_lt_succ_succ b)) ?_
rw [← pos_iff_ne_zero]
exact Nat.div_pos (le_of_not_lt hnb) (zero_lt_succ (succ b))
#align nat.last_digit_ne_zero Nat.getLast_digit_ne_zero
theorem mul_ofDigits (n : ℕ) {b : ℕ} {l : List ℕ} :
n * ofDigits b l = ofDigits b (l.map (n * ·)) := by
induction l with
| nil => rfl
| cons hd tl ih =>
rw [List.map_cons, ofDigits_cons, ofDigits_cons, ← ih]
ring
theorem ofDigits_add_ofDigits_eq_ofDigits_zipWith_of_length_eq {b : ℕ} {l1 l2 : List ℕ}
(h : l1.length = l2.length) :
ofDigits b l1 + ofDigits b l2 = ofDigits b (l1.zipWith (· + ·) l2) := by
induction l1 generalizing l2 with
| nil => simp_all [eq_comm, List.length_eq_zero, ofDigits]
| cons hd₁ tl₁ ih₁ =>
induction l2 generalizing tl₁ with
| nil => simp_all
| cons hd₂ tl₂ ih₂ =>
simp_all only [List.length_cons, succ_eq_add_one, ofDigits_cons, add_left_inj,
eq_comm, List.zipWith_cons_cons, add_eq]
rw [← ih₁ h.symm, mul_add]
ac_rfl
theorem digits_lt_base' {b m : ℕ} : ∀ {d}, d ∈ digits (b + 2) m → d < b + 2 := by
apply Nat.strongInductionOn m
intro n IH d hd
cases' n with n
· rw [digits_zero] at hd
cases hd
-- base b+2 expansion of 0 has no digits
rw [digits_add_two_add_one] at hd
cases hd
· exact n.succ.mod_lt (by simp)
-- Porting note: Previous code (single line) contained linarith.
-- . exact IH _ (Nat.div_lt_self (Nat.succ_pos _) (by linarith)) hd
· apply IH ((n + 1) / (b + 2))
· apply Nat.div_lt_self <;> omega
· assumption
#align nat.digits_lt_base' Nat.digits_lt_base'
theorem digits_lt_base {b m d : ℕ} (hb : 1 < b) (hd : d ∈ digits b m) : d < b := by
rcases b with (_ | _ | b) <;> try simp_all
exact digits_lt_base' hd
#align nat.digits_lt_base Nat.digits_lt_base
theorem ofDigits_lt_base_pow_length' {b : ℕ} {l : List ℕ} (hl : ∀ x ∈ l, x < b + 2) :
ofDigits (b + 2) l < (b + 2) ^ l.length := by
induction' l with hd tl IH
· simp [ofDigits]
· rw [ofDigits, List.length_cons, pow_succ]
have : (ofDigits (b + 2) tl + 1) * (b + 2) ≤ (b + 2) ^ tl.length * (b + 2) :=
mul_le_mul (IH fun x hx => hl _ (List.mem_cons_of_mem _ hx)) (by rfl) (by simp only [zero_le])
(Nat.zero_le _)
suffices ↑hd < b + 2 by linarith
exact hl hd (List.mem_cons_self _ _)
#align nat.of_digits_lt_base_pow_length' Nat.ofDigits_lt_base_pow_length'
theorem ofDigits_lt_base_pow_length {b : ℕ} {l : List ℕ} (hb : 1 < b) (hl : ∀ x ∈ l, x < b) :
ofDigits b l < b ^ l.length := by
rcases b with (_ | _ | b) <;> try simp_all
exact ofDigits_lt_base_pow_length' hl
#align nat.of_digits_lt_base_pow_length Nat.ofDigits_lt_base_pow_length
theorem lt_base_pow_length_digits' {b m : ℕ} : m < (b + 2) ^ (digits (b + 2) m).length := by
convert @ofDigits_lt_base_pow_length' b (digits (b + 2) m) fun _ => digits_lt_base'
rw [ofDigits_digits (b + 2) m]
#align nat.lt_base_pow_length_digits' Nat.lt_base_pow_length_digits'
theorem lt_base_pow_length_digits {b m : ℕ} (hb : 1 < b) : m < b ^ (digits b m).length := by
rcases b with (_ | _ | b) <;> try simp_all
exact lt_base_pow_length_digits'
#align nat.lt_base_pow_length_digits Nat.lt_base_pow_length_digits
theorem ofDigits_digits_append_digits {b m n : ℕ} :
ofDigits b (digits b n ++ digits b m) = n + b ^ (digits b n).length * m := by
rw [ofDigits_append, ofDigits_digits, ofDigits_digits]
#align nat.of_digits_digits_append_digits Nat.ofDigits_digits_append_digits
theorem digits_append_digits {b m n : ℕ} (hb : 0 < b) :
digits b n ++ digits b m = digits b (n + b ^ (digits b n).length * m) := by
rcases eq_or_lt_of_le (Nat.succ_le_of_lt hb) with (rfl | hb)
· simp [List.replicate_add]
rw [← ofDigits_digits_append_digits]
refine (digits_ofDigits b hb _ (fun l hl => ?_) (fun h_append => ?_)).symm
· rcases (List.mem_append.mp hl) with (h | h) <;> exact digits_lt_base hb h
· by_cases h : digits b m = []
· simp only [h, List.append_nil] at h_append ⊢
exact getLast_digit_ne_zero b <| digits_ne_nil_iff_ne_zero.mp h_append
· exact (List.getLast_append' _ _ h) ▸
(getLast_digit_ne_zero _ <| digits_ne_nil_iff_ne_zero.mp h)
theorem digits_len_le_digits_len_succ (b n : ℕ) :
(digits b n).length ≤ (digits b (n + 1)).length := by
rcases Decidable.eq_or_ne n 0 with (rfl | hn)
· simp
rcases le_or_lt b 1 with hb | hb
· interval_cases b <;> simp_arith [digits_zero_succ', hn]
simpa [digits_len, hb, hn] using log_mono_right (le_succ _)
#align nat.digits_len_le_digits_len_succ Nat.digits_len_le_digits_len_succ
theorem le_digits_len_le (b n m : ℕ) (h : n ≤ m) : (digits b n).length ≤ (digits b m).length :=
monotone_nat_of_le_succ (digits_len_le_digits_len_succ b) h
#align nat.le_digits_len_le Nat.le_digits_len_le
@[mono]
theorem ofDigits_monotone {p q : ℕ} (L : List ℕ) (h : p ≤ q) : ofDigits p L ≤ ofDigits q L := by
induction' L with _ _ hi
· rfl
· simp only [ofDigits, cast_id, add_le_add_iff_left]
exact Nat.mul_le_mul h hi
theorem sum_le_ofDigits {p : ℕ} (L : List ℕ) (h : 1 ≤ p) : L.sum ≤ ofDigits p L :=
(ofDigits_one L).symm ▸ ofDigits_monotone L h
theorem digit_sum_le (p n : ℕ) : List.sum (digits p n) ≤ n := by
induction' n with n
· exact digits_zero _ ▸ Nat.le_refl (List.sum [])
· induction' p with p
· rw [digits_zero_succ, List.sum_cons, List.sum_nil, add_zero]
· nth_rw 2 [← ofDigits_digits p.succ (n + 1)]
rw [← ofDigits_one <| digits p.succ n.succ]
exact ofDigits_monotone (digits p.succ n.succ) <| Nat.succ_pos p
theorem pow_length_le_mul_ofDigits {b : ℕ} {l : List ℕ} (hl : l ≠ []) (hl2 : l.getLast hl ≠ 0) :
(b + 2) ^ l.length ≤ (b + 2) * ofDigits (b + 2) l := by
rw [← List.dropLast_append_getLast hl]
simp only [List.length_append, List.length, zero_add, List.length_dropLast, ofDigits_append,
List.length_dropLast, ofDigits_singleton, add_comm (l.length - 1), pow_add, pow_one]
apply Nat.mul_le_mul_left
refine le_trans ?_ (Nat.le_add_left _ _)
have : 0 < l.getLast hl := by rwa [pos_iff_ne_zero]
convert Nat.mul_le_mul_left ((b + 2) ^ (l.length - 1)) this using 1
rw [Nat.mul_one]
#align nat.pow_length_le_mul_of_digits Nat.pow_length_le_mul_ofDigits
theorem base_pow_length_digits_le' (b m : ℕ) (hm : m ≠ 0) :
(b + 2) ^ (digits (b + 2) m).length ≤ (b + 2) * m := by
have : digits (b + 2) m ≠ [] := digits_ne_nil_iff_ne_zero.mpr hm
convert @pow_length_le_mul_ofDigits b (digits (b+2) m)
this (getLast_digit_ne_zero _ hm)
rw [ofDigits_digits]
#align nat.base_pow_length_digits_le' Nat.base_pow_length_digits_le'
theorem base_pow_length_digits_le (b m : ℕ) (hb : 1 < b) :
m ≠ 0 → b ^ (digits b m).length ≤ b * m := by
rcases b with (_ | _ | b) <;> try simp_all
exact base_pow_length_digits_le' b m
#align nat.base_pow_length_digits_le Nat.base_pow_length_digits_le
lemma ofDigits_div_eq_ofDigits_tail {p : ℕ} (hpos : 0 < p) (digits : List ℕ)
(w₁ : ∀ l ∈ digits, l < p) : ofDigits p digits / p = ofDigits p digits.tail := by
induction' digits with hd tl
· simp [ofDigits]
· refine Eq.trans (add_mul_div_left hd _ hpos) ?_
rw [Nat.div_eq_of_lt <| w₁ _ <| List.mem_cons_self _ _, zero_add]
rfl
lemma ofDigits_div_pow_eq_ofDigits_drop
{p : ℕ} (i : ℕ) (hpos : 0 < p) (digits : List ℕ) (w₁ : ∀ l ∈ digits, l < p) :
ofDigits p digits / p ^ i = ofDigits p (digits.drop i) := by
induction' i with i hi
· simp
· rw [Nat.pow_succ, ← Nat.div_div_eq_div_mul, hi, ofDigits_div_eq_ofDigits_tail hpos
(List.drop i digits) fun x hx ↦ w₁ x <| List.mem_of_mem_drop hx, ← List.drop_one,
List.drop_drop, add_comm]
lemma self_div_pow_eq_ofDigits_drop {p : ℕ} (i n : ℕ) (h : 2 ≤ p):
n / p ^ i = ofDigits p ((p.digits n).drop i) := by
convert ofDigits_div_pow_eq_ofDigits_drop i (zero_lt_of_lt h) (p.digits n)
(fun l hl ↦ digits_lt_base h hl)
exact (ofDigits_digits p n).symm
open Finset
theorem sub_one_mul_sum_div_pow_eq_sub_sum_digits {p : ℕ}
(L : List ℕ) {h_nonempty} (h_ne_zero : L.getLast h_nonempty ≠ 0) (h_lt : ∀ l ∈ L, l < p) :
(p - 1) * ∑ i ∈ range L.length, (ofDigits p L) / p ^ i.succ = (ofDigits p L) - L.sum := by
obtain h | rfl | h : 1 < p ∨ 1 = p ∨ p < 1 := trichotomous 1 p
· induction' L with hd tl ih
· simp [ofDigits]
· simp only [List.length_cons, List.sum_cons, self_div_pow_eq_ofDigits_drop _ _ h,
digits_ofDigits p h (hd :: tl) h_lt (fun _ => h_ne_zero)]
simp only [ofDigits]
rw [sum_range_succ, Nat.cast_id]
simp only [List.drop, List.drop_length]
obtain rfl | h' := em <| tl = []
· simp [ofDigits]
· have w₁' := fun l hl ↦ h_lt l <| List.mem_cons_of_mem hd hl
have w₂' := fun (h : tl ≠ []) ↦ (List.getLast_cons h) ▸ h_ne_zero
have ih := ih (w₂' h') w₁'
simp only [self_div_pow_eq_ofDigits_drop _ _ h, digits_ofDigits p h tl w₁' w₂',
← Nat.one_add] at ih
have := sum_singleton (fun x ↦ ofDigits p <| tl.drop x) tl.length
rw [← Ico_succ_singleton, List.drop_length, ofDigits] at this
have h₁ : 1 ≤ tl.length := List.length_pos.mpr h'
rw [← sum_range_add_sum_Ico _ <| h₁, ← add_zero (∑ x ∈ Ico _ _, ofDigits p (tl.drop x)),
← this, sum_Ico_consecutive _ h₁ <| (le_add_right tl.length 1),
← sum_Ico_add _ 0 tl.length 1,
Ico_zero_eq_range, mul_add, mul_add, ih, range_one, sum_singleton, List.drop, ofDigits,
mul_zero, add_zero, ← Nat.add_sub_assoc <| sum_le_ofDigits _ <| Nat.le_of_lt h]
nth_rw 2 [← one_mul <| ofDigits p tl]
rw [← add_mul, one_eq_succ_zero, Nat.sub_add_cancel <| zero_lt_of_lt h,
Nat.add_sub_add_left]
· simp [ofDigits_one]
· simp [lt_one_iff.mp h]
cases L
· rfl
· simp [ofDigits]
theorem sub_one_mul_sum_log_div_pow_eq_sub_sum_digits {p : ℕ} (n : ℕ) :
(p - 1) * ∑ i ∈ range (log p n).succ, n / p ^ i.succ = n - (p.digits n).sum := by
obtain h | rfl | h : 1 < p ∨ 1 = p ∨ p < 1 := trichotomous 1 p
· rcases eq_or_ne n 0 with rfl | hn
· simp
· convert sub_one_mul_sum_div_pow_eq_sub_sum_digits (p.digits n) (getLast_digit_ne_zero p hn) <|
(fun l a ↦ digits_lt_base h a)
· refine (digits_len p n h hn).symm
all_goals exact (ofDigits_digits p n).symm
· simp
· simp [lt_one_iff.mp h]
cases n
all_goals simp
theorem digits_two_eq_bits (n : ℕ) : digits 2 n = n.bits.map fun b => cond b 1 0 := by
induction' n using Nat.binaryRecFromOne with b n h ih
· simp
· rfl
rw [bits_append_bit _ _ fun hn => absurd hn h]
cases b
· rw [digits_def' one_lt_two]
· simpa [Nat.bit, Nat.bit0_val n]
· simpa [pos_iff_ne_zero, Nat.bit0_eq_zero]
· simpa [Nat.bit, Nat.bit1_val n, add_comm, digits_add 2 one_lt_two 1 n, Nat.add_mul_div_left]
#align nat.digits_two_eq_bits Nat.digits_two_eq_bits
-- This is really a theorem about polynomials.
theorem dvd_ofDigits_sub_ofDigits {α : Type*} [CommRing α] {a b k : α} (h : k ∣ a - b)
(L : List ℕ) : k ∣ ofDigits a L - ofDigits b L := by
induction' L with d L ih
· change k ∣ 0 - 0
simp
· simp only [ofDigits, add_sub_add_left_eq_sub]
exact dvd_mul_sub_mul h ih
#align nat.dvd_of_digits_sub_of_digits Nat.dvd_ofDigits_sub_ofDigits
theorem ofDigits_modEq' (b b' : ℕ) (k : ℕ) (h : b ≡ b' [MOD k]) (L : List ℕ) :
ofDigits b L ≡ ofDigits b' L [MOD k] := by
induction' L with d L ih
· rfl
· dsimp [ofDigits]
dsimp [Nat.ModEq] at *
conv_lhs => rw [Nat.add_mod, Nat.mul_mod, h, ih]
conv_rhs => rw [Nat.add_mod, Nat.mul_mod]
#align nat.of_digits_modeq' Nat.ofDigits_modEq'
theorem ofDigits_modEq (b k : ℕ) (L : List ℕ) : ofDigits b L ≡ ofDigits (b % k) L [MOD k] :=
ofDigits_modEq' b (b % k) k (b.mod_modEq k).symm L
#align nat.of_digits_modeq Nat.ofDigits_modEq
theorem ofDigits_mod (b k : ℕ) (L : List ℕ) : ofDigits b L % k = ofDigits (b % k) L % k :=
ofDigits_modEq b k L
#align nat.of_digits_mod Nat.ofDigits_mod
theorem ofDigits_mod_eq_head! (b : ℕ) (l : List ℕ) : ofDigits b l % b = l.head! % b := by
induction l <;> simp [Nat.ofDigits, Int.ModEq]
| Mathlib/Data/Nat/Digits.lean | 669 | 677 | theorem head!_digits {b n : ℕ} (h : b ≠ 1) : (Nat.digits b n).head! = n % b := by |
by_cases hb : 1 < b
· rcases n with _ | n
· simp
· nth_rw 2 [← Nat.ofDigits_digits b (n + 1)]
rw [Nat.ofDigits_mod_eq_head! _ _]
exact (Nat.mod_eq_of_lt (Nat.digits_lt_base hb <| List.head!_mem_self <|
Nat.digits_ne_nil_iff_ne_zero.mpr <| Nat.succ_ne_zero n)).symm
· rcases n with _ | _ <;> simp_all [show b = 0 by omega]
|
import Mathlib.Algebra.Algebra.Equiv
import Mathlib.LinearAlgebra.Dimension.StrongRankCondition
import Mathlib.LinearAlgebra.FreeModule.Basic
import Mathlib.LinearAlgebra.FreeModule.Finite.Basic
import Mathlib.SetTheory.Cardinal.Ordinal
#align_import algebra.quaternion from "leanprover-community/mathlib"@"cf7a7252c1989efe5800e0b3cdfeb4228ac6b40e"
@[ext]
structure QuaternionAlgebra (R : Type*) (a b : R) where
re : R
imI : R
imJ : R
imK : R
#align quaternion_algebra QuaternionAlgebra
#align quaternion_algebra.re QuaternionAlgebra.re
#align quaternion_algebra.im_i QuaternionAlgebra.imI
#align quaternion_algebra.im_j QuaternionAlgebra.imJ
#align quaternion_algebra.im_k QuaternionAlgebra.imK
@[inherit_doc]
scoped[Quaternion] notation "ℍ[" R "," a "," b "]" => QuaternionAlgebra R a b
open Quaternion
namespace QuaternionAlgebra
@[simps]
def equivProd {R : Type*} (c₁ c₂ : R) : ℍ[R,c₁,c₂] ≃ R × R × R × R where
toFun a := ⟨a.1, a.2, a.3, a.4⟩
invFun a := ⟨a.1, a.2.1, a.2.2.1, a.2.2.2⟩
left_inv _ := rfl
right_inv _ := rfl
#align quaternion_algebra.equiv_prod QuaternionAlgebra.equivProd
@[simps symm_apply]
def equivTuple {R : Type*} (c₁ c₂ : R) : ℍ[R,c₁,c₂] ≃ (Fin 4 → R) where
toFun a := ![a.1, a.2, a.3, a.4]
invFun a := ⟨a 0, a 1, a 2, a 3⟩
left_inv _ := rfl
right_inv f := by ext ⟨_, _ | _ | _ | _ | _ | ⟨⟩⟩ <;> rfl
#align quaternion_algebra.equiv_tuple QuaternionAlgebra.equivTuple
@[simp]
theorem equivTuple_apply {R : Type*} (c₁ c₂ : R) (x : ℍ[R,c₁,c₂]) :
equivTuple c₁ c₂ x = ![x.re, x.imI, x.imJ, x.imK] :=
rfl
#align quaternion_algebra.equiv_tuple_apply QuaternionAlgebra.equivTuple_apply
@[simp]
theorem mk.eta {R : Type*} {c₁ c₂} (a : ℍ[R,c₁,c₂]) : mk a.1 a.2 a.3 a.4 = a := rfl
#align quaternion_algebra.mk.eta QuaternionAlgebra.mk.eta
variable {S T R : Type*} [CommRing R] {c₁ c₂ : R} (r x y z : R) (a b c : ℍ[R,c₁,c₂])
instance [Subsingleton R] : Subsingleton ℍ[R, c₁, c₂] := (equivTuple c₁ c₂).subsingleton
instance [Nontrivial R] : Nontrivial ℍ[R, c₁, c₂] := (equivTuple c₁ c₂).surjective.nontrivial
def im (x : ℍ[R,c₁,c₂]) : ℍ[R,c₁,c₂] :=
⟨0, x.imI, x.imJ, x.imK⟩
#align quaternion_algebra.im QuaternionAlgebra.im
@[simp]
theorem im_re : a.im.re = 0 :=
rfl
#align quaternion_algebra.im_re QuaternionAlgebra.im_re
@[simp]
theorem im_imI : a.im.imI = a.imI :=
rfl
#align quaternion_algebra.im_im_i QuaternionAlgebra.im_imI
@[simp]
theorem im_imJ : a.im.imJ = a.imJ :=
rfl
#align quaternion_algebra.im_im_j QuaternionAlgebra.im_imJ
@[simp]
theorem im_imK : a.im.imK = a.imK :=
rfl
#align quaternion_algebra.im_im_k QuaternionAlgebra.im_imK
@[simp]
theorem im_idem : a.im.im = a.im :=
rfl
#align quaternion_algebra.im_idem QuaternionAlgebra.im_idem
@[coe] def coe (x : R) : ℍ[R,c₁,c₂] := ⟨x, 0, 0, 0⟩
instance : CoeTC R ℍ[R,c₁,c₂] := ⟨coe⟩
@[simp, norm_cast]
theorem coe_re : (x : ℍ[R,c₁,c₂]).re = x := rfl
#align quaternion_algebra.coe_re QuaternionAlgebra.coe_re
@[simp, norm_cast]
theorem coe_imI : (x : ℍ[R,c₁,c₂]).imI = 0 := rfl
#align quaternion_algebra.coe_im_i QuaternionAlgebra.coe_imI
@[simp, norm_cast]
theorem coe_imJ : (x : ℍ[R,c₁,c₂]).imJ = 0 := rfl
#align quaternion_algebra.coe_im_j QuaternionAlgebra.coe_imJ
@[simp, norm_cast]
theorem coe_imK : (x : ℍ[R,c₁,c₂]).imK = 0 := rfl
#align quaternion_algebra.coe_im_k QuaternionAlgebra.coe_imK
theorem coe_injective : Function.Injective (coe : R → ℍ[R,c₁,c₂]) := fun _ _ h => congr_arg re h
#align quaternion_algebra.coe_injective QuaternionAlgebra.coe_injective
@[simp]
theorem coe_inj {x y : R} : (x : ℍ[R,c₁,c₂]) = y ↔ x = y :=
coe_injective.eq_iff
#align quaternion_algebra.coe_inj QuaternionAlgebra.coe_inj
-- Porting note: removed `simps`, added simp lemmas manually
instance : Zero ℍ[R,c₁,c₂] := ⟨⟨0, 0, 0, 0⟩⟩
@[simp] theorem zero_re : (0 : ℍ[R,c₁,c₂]).re = 0 := rfl
#align quaternion_algebra.has_zero_zero_re QuaternionAlgebra.zero_re
@[simp] theorem zero_imI : (0 : ℍ[R,c₁,c₂]).imI = 0 := rfl
#align quaternion_algebra.has_zero_zero_im_i QuaternionAlgebra.zero_imI
@[simp] theorem zero_imJ : (0 : ℍ[R,c₁,c₂]).imJ = 0 := rfl
#align quaternion_algebra.zero_zero_im_j QuaternionAlgebra.zero_imJ
@[simp] theorem zero_imK : (0 : ℍ[R,c₁,c₂]).imK = 0 := rfl
#align quaternion_algebra.zero_zero_im_k QuaternionAlgebra.zero_imK
@[simp] theorem zero_im : (0 : ℍ[R,c₁,c₂]).im = 0 := rfl
@[simp, norm_cast]
theorem coe_zero : ((0 : R) : ℍ[R,c₁,c₂]) = 0 := rfl
#align quaternion_algebra.coe_zero QuaternionAlgebra.coe_zero
instance : Inhabited ℍ[R,c₁,c₂] := ⟨0⟩
-- Porting note: removed `simps`, added simp lemmas manually
instance : One ℍ[R,c₁,c₂] := ⟨⟨1, 0, 0, 0⟩⟩
@[simp] theorem one_re : (1 : ℍ[R,c₁,c₂]).re = 1 := rfl
#align quaternion_algebra.has_one_one_re QuaternionAlgebra.one_re
@[simp] theorem one_imI : (1 : ℍ[R,c₁,c₂]).imI = 0 := rfl
#align quaternion_algebra.has_one_one_im_i QuaternionAlgebra.one_imI
@[simp] theorem one_imJ : (1 : ℍ[R,c₁,c₂]).imJ = 0 := rfl
#align quaternion_algebra.one_one_im_j QuaternionAlgebra.one_imJ
@[simp] theorem one_imK : (1 : ℍ[R,c₁,c₂]).imK = 0 := rfl
#align quaternion_algebra.one_one_im_k QuaternionAlgebra.one_imK
@[simp] theorem one_im : (1 : ℍ[R,c₁,c₂]).im = 0 := rfl
@[simp, norm_cast]
theorem coe_one : ((1 : R) : ℍ[R,c₁,c₂]) = 1 := rfl
#align quaternion_algebra.coe_one QuaternionAlgebra.coe_one
-- Porting note: removed `simps`, added simp lemmas manually
instance : Add ℍ[R,c₁,c₂] :=
⟨fun a b => ⟨a.1 + b.1, a.2 + b.2, a.3 + b.3, a.4 + b.4⟩⟩
@[simp] theorem add_re : (a + b).re = a.re + b.re := rfl
#align quaternion_algebra.has_add_add_re QuaternionAlgebra.add_re
@[simp] theorem add_imI : (a + b).imI = a.imI + b.imI := rfl
#align quaternion_algebra.has_add_add_im_i QuaternionAlgebra.add_imI
@[simp] theorem add_imJ : (a + b).imJ = a.imJ + b.imJ := rfl
#align quaternion_algebra.has_add_add_im_j QuaternionAlgebra.add_imJ
@[simp] theorem add_imK : (a + b).imK = a.imK + b.imK := rfl
#align quaternion_algebra.has_add_add_im_k QuaternionAlgebra.add_imK
@[simp] theorem add_im : (a + b).im = a.im + b.im :=
QuaternionAlgebra.ext _ _ (zero_add _).symm rfl rfl rfl
@[simp]
theorem mk_add_mk (a₁ a₂ a₃ a₄ b₁ b₂ b₃ b₄ : R) :
(mk a₁ a₂ a₃ a₄ : ℍ[R,c₁,c₂]) + mk b₁ b₂ b₃ b₄ = mk (a₁ + b₁) (a₂ + b₂) (a₃ + b₃) (a₄ + b₄) :=
rfl
#align quaternion_algebra.mk_add_mk QuaternionAlgebra.mk_add_mk
@[simp, norm_cast]
| Mathlib/Algebra/Quaternion.lean | 237 | 237 | theorem coe_add : ((x + y : R) : ℍ[R,c₁,c₂]) = x + y := by | ext <;> simp
|
import Mathlib.RingTheory.WittVector.Truncated
import Mathlib.RingTheory.WittVector.Identities
import Mathlib.NumberTheory.Padics.RingHoms
#align_import ring_theory.witt_vector.compare from "leanprover-community/mathlib"@"168ad7fc5d8173ad38be9767a22d50b8ecf1cd00"
noncomputable section
variable {p : ℕ} [hp : Fact p.Prime]
local notation "𝕎" => WittVector p
namespace TruncatedWittVector
variable (p) (n : ℕ) (R : Type*) [CommRing R]
theorem eq_of_le_of_cast_pow_eq_zero [CharP R p] (i : ℕ) (hin : i ≤ n)
(hpi : (p : TruncatedWittVector p n R) ^ i = 0) : i = n := by
contrapose! hpi
replace hin := lt_of_le_of_ne hin hpi; clear hpi
have : (p : TruncatedWittVector p n R) ^ i = WittVector.truncate n ((p : 𝕎 R) ^ i) := by
rw [RingHom.map_pow, map_natCast]
rw [this, ne_eq, ext_iff, not_forall]; clear this
use ⟨i, hin⟩
rw [WittVector.coeff_truncate, coeff_zero, Fin.val_mk, WittVector.coeff_p_pow]
haveI : Nontrivial R := CharP.nontrivial_of_char_ne_one hp.1.ne_one
exact one_ne_zero
#align truncated_witt_vector.eq_of_le_of_cast_pow_eq_zero TruncatedWittVector.eq_of_le_of_cast_pow_eq_zero
section Iso
variable {R}
theorem card_zmod : Fintype.card (TruncatedWittVector p n (ZMod p)) = p ^ n := by
rw [card, ZMod.card]
#align truncated_witt_vector.card_zmod TruncatedWittVector.card_zmod
theorem charP_zmod : CharP (TruncatedWittVector p n (ZMod p)) (p ^ n) :=
charP_of_prime_pow_injective _ _ _ (card_zmod _ _) (eq_of_le_of_cast_pow_eq_zero p n (ZMod p))
#align truncated_witt_vector.char_p_zmod TruncatedWittVector.charP_zmod
attribute [local instance] charP_zmod
def zmodEquivTrunc : ZMod (p ^ n) ≃+* TruncatedWittVector p n (ZMod p) :=
ZMod.ringEquiv (TruncatedWittVector p n (ZMod p)) (card_zmod _ _)
#align truncated_witt_vector.zmod_equiv_trunc TruncatedWittVector.zmodEquivTrunc
theorem zmodEquivTrunc_apply {x : ZMod (p ^ n)} :
zmodEquivTrunc p n x = ZMod.castHom (by rfl) (TruncatedWittVector p n (ZMod p)) x :=
rfl
#align truncated_witt_vector.zmod_equiv_trunc_apply TruncatedWittVector.zmodEquivTrunc_apply
theorem commutes {m : ℕ} (hm : n ≤ m) :
(truncate hm).comp (zmodEquivTrunc p m).toRingHom =
(zmodEquivTrunc p n).toRingHom.comp (ZMod.castHom (pow_dvd_pow p hm) _) :=
RingHom.ext_zmod _ _
#align truncated_witt_vector.commutes TruncatedWittVector.commutes
theorem commutes' {m : ℕ} (hm : n ≤ m) (x : ZMod (p ^ m)) :
truncate hm (zmodEquivTrunc p m x) = zmodEquivTrunc p n (ZMod.castHom (pow_dvd_pow p hm) _ x) :=
show (truncate hm).comp (zmodEquivTrunc p m).toRingHom x = _ by rw [commutes _ _ hm]; rfl
#align truncated_witt_vector.commutes' TruncatedWittVector.commutes'
| Mathlib/RingTheory/WittVector/Compare.lean | 107 | 112 | theorem commutes_symm' {m : ℕ} (hm : n ≤ m) (x : TruncatedWittVector p m (ZMod p)) :
(zmodEquivTrunc p n).symm (truncate hm x) =
ZMod.castHom (pow_dvd_pow p hm) _ ((zmodEquivTrunc p m).symm x) := by |
apply (zmodEquivTrunc p n).injective
rw [← commutes' _ _ hm]
simp
|
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)
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
#align finrank_vector_span_image_finset_le finrank_vectorSpan_image_finset_le
theorem finrank_vectorSpan_range_le [Fintype ι] (p : ι → P) {n : ℕ} (hc : Fintype.card ι = n + 1) :
finrank k (vectorSpan k (Set.range p)) ≤ n := by
classical
rw [← Set.image_univ, ← Finset.coe_univ, ← Finset.coe_image]
rw [← Finset.card_univ] at hc
exact finrank_vectorSpan_image_finset_le _ _ _ hc
#align finrank_vector_span_range_le finrank_vectorSpan_range_le
lemma finrank_vectorSpan_range_add_one_le [Fintype ι] [Nonempty ι] (p : ι → P) :
finrank k (vectorSpan k (Set.range p)) + 1 ≤ Fintype.card ι :=
(le_tsub_iff_right $ Nat.succ_le_iff.2 Fintype.card_pos).1 $ finrank_vectorSpan_range_le _ _
(tsub_add_cancel_of_le $ Nat.succ_le_iff.2 Fintype.card_pos).symm
theorem affineIndependent_iff_finrank_vectorSpan_eq [Fintype ι] (p : ι → P) {n : ℕ}
(hc : Fintype.card ι = n + 1) :
AffineIndependent k p ↔ finrank k (vectorSpan k (Set.range p)) = n := by
classical
have hn : Nonempty ι := by simp [← Fintype.card_pos_iff, hc]
cases' hn with i₁
rw [affineIndependent_iff_linearIndependent_vsub _ _ i₁,
linearIndependent_iff_card_eq_finrank_span, eq_comm,
vectorSpan_range_eq_span_range_vsub_right_ne k p i₁, Set.finrank]
rw [← Finset.card_univ] at hc
rw [Fintype.subtype_card]
simp [Finset.filter_ne', Finset.card_erase_of_mem, hc]
#align affine_independent_iff_finrank_vector_span_eq affineIndependent_iff_finrank_vectorSpan_eq
theorem affineIndependent_iff_le_finrank_vectorSpan [Fintype ι] (p : ι → P) {n : ℕ}
(hc : Fintype.card ι = n + 1) :
AffineIndependent k p ↔ n ≤ finrank k (vectorSpan k (Set.range p)) := by
rw [affineIndependent_iff_finrank_vectorSpan_eq k p hc]
constructor
· rintro rfl
rfl
· exact fun hle => le_antisymm (finrank_vectorSpan_range_le k p hc) hle
#align affine_independent_iff_le_finrank_vector_span affineIndependent_iff_le_finrank_vectorSpan
theorem affineIndependent_iff_not_finrank_vectorSpan_le [Fintype ι] (p : ι → P) {n : ℕ}
(hc : Fintype.card ι = n + 2) :
AffineIndependent k p ↔ ¬finrank k (vectorSpan k (Set.range p)) ≤ n := by
rw [affineIndependent_iff_le_finrank_vectorSpan k p hc, ← Nat.lt_iff_add_one_le, lt_iff_not_ge]
#align affine_independent_iff_not_finrank_vector_span_le affineIndependent_iff_not_finrank_vectorSpan_le
theorem finrank_vectorSpan_le_iff_not_affineIndependent [Fintype ι] (p : ι → P) {n : ℕ}
(hc : Fintype.card ι = n + 2) :
finrank k (vectorSpan k (Set.range p)) ≤ n ↔ ¬AffineIndependent k p :=
(not_iff_comm.1 (affineIndependent_iff_not_finrank_vectorSpan_le k p hc).symm).symm
#align finrank_vector_span_le_iff_not_affine_independent finrank_vectorSpan_le_iff_not_affineIndependent
variable {k}
lemma AffineIndependent.card_le_finrank_succ [Fintype ι] {p : ι → P} (hp : AffineIndependent k p) :
Fintype.card ι ≤ FiniteDimensional.finrank k (vectorSpan k (Set.range p)) + 1 := by
cases isEmpty_or_nonempty ι
· simp [Fintype.card_eq_zero]
rw [← tsub_le_iff_right]
exact (affineIndependent_iff_le_finrank_vectorSpan _ _
(tsub_add_cancel_of_le <| Nat.one_le_iff_ne_zero.2 Fintype.card_ne_zero).symm).1 hp
open Finset in
lemma AffineIndependent.card_le_card_of_subset_affineSpan {s t : Finset V}
(hs : AffineIndependent k ((↑) : s → V)) (hst : (s : Set V) ⊆ affineSpan k (t : Set V)) :
s.card ≤ t.card := by
obtain rfl | hs' := s.eq_empty_or_nonempty
· simp
obtain rfl | ht' := t.eq_empty_or_nonempty
· simpa [Set.subset_empty_iff] using hst
have := hs'.to_subtype
have := ht'.to_set.to_subtype
have direction_le := AffineSubspace.direction_le (affineSpan_mono k hst)
rw [AffineSubspace.affineSpan_coe, direction_affineSpan, direction_affineSpan,
← @Subtype.range_coe _ (s : Set V), ← @Subtype.range_coe _ (t : Set V)] at direction_le
have finrank_le := add_le_add_right (Submodule.finrank_le_finrank_of_le direction_le) 1
-- We use `erw` to elide the difference between `↥s` and `↥(s : Set V)}`
erw [hs.finrank_vectorSpan_add_one] at finrank_le
simpa using finrank_le.trans <| finrank_vectorSpan_range_add_one_le _ _
open Finset in
lemma AffineIndependent.card_lt_card_of_affineSpan_lt_affineSpan {s t : Finset V}
(hs : AffineIndependent k ((↑) : s → V))
(hst : affineSpan k (s : Set V) < affineSpan k (t : Set V)) : s.card < t.card := by
obtain rfl | hs' := s.eq_empty_or_nonempty
· simpa [card_pos] using hst
obtain rfl | ht' := t.eq_empty_or_nonempty
· simp [Set.subset_empty_iff] at hst
have := hs'.to_subtype
have := ht'.to_set.to_subtype
have dir_lt := AffineSubspace.direction_lt_of_nonempty (k := k) hst $ hs'.to_set.affineSpan k
rw [direction_affineSpan, direction_affineSpan,
← @Subtype.range_coe _ (s : Set V), ← @Subtype.range_coe _ (t : Set V)] at dir_lt
have finrank_lt := add_lt_add_right (Submodule.finrank_lt_finrank_of_lt dir_lt) 1
-- We use `erw` to elide the difference between `↥s` and `↥(s : Set V)}`
erw [hs.finrank_vectorSpan_add_one] at finrank_lt
simpa using finrank_lt.trans_le <| finrank_vectorSpan_range_add_one_le _ _
theorem AffineIndependent.vectorSpan_image_finset_eq_of_le_of_card_eq_finrank_add_one
[DecidableEq P] {p : ι → P}
(hi : AffineIndependent k p) {s : Finset ι} {sm : Submodule k V} [FiniteDimensional k sm]
(hle : vectorSpan k (s.image p : Set P) ≤ sm) (hc : Finset.card s = finrank k sm + 1) :
vectorSpan k (s.image p : Set P) = sm :=
eq_of_le_of_finrank_eq hle <| hi.finrank_vectorSpan_image_finset hc
#align affine_independent.vector_span_image_finset_eq_of_le_of_card_eq_finrank_add_one AffineIndependent.vectorSpan_image_finset_eq_of_le_of_card_eq_finrank_add_one
theorem AffineIndependent.vectorSpan_eq_of_le_of_card_eq_finrank_add_one [Fintype ι] {p : ι → P}
(hi : AffineIndependent k p) {sm : Submodule k V} [FiniteDimensional k sm]
(hle : vectorSpan k (Set.range p) ≤ sm) (hc : Fintype.card ι = finrank k sm + 1) :
vectorSpan k (Set.range p) = sm :=
eq_of_le_of_finrank_eq hle <| hi.finrank_vectorSpan hc
#align affine_independent.vector_span_eq_of_le_of_card_eq_finrank_add_one AffineIndependent.vectorSpan_eq_of_le_of_card_eq_finrank_add_one
| Mathlib/LinearAlgebra/AffineSpace/FiniteDimensional.lean | 296 | 307 | theorem AffineIndependent.affineSpan_image_finset_eq_of_le_of_card_eq_finrank_add_one
[DecidableEq P] {p : ι → P}
(hi : AffineIndependent k p) {s : Finset ι} {sp : AffineSubspace k P}
[FiniteDimensional k sp.direction] (hle : affineSpan k (s.image p : Set P) ≤ sp)
(hc : Finset.card s = finrank k sp.direction + 1) : affineSpan k (s.image p : Set P) = sp := by |
have hn : s.Nonempty := by
rw [← Finset.card_pos, hc]
apply Nat.succ_pos
refine eq_of_direction_eq_of_nonempty_of_le ?_ ((hn.image p).to_set.affineSpan k) hle
have hd := direction_le hle
rw [direction_affineSpan] at hd ⊢
exact hi.vectorSpan_image_finset_eq_of_le_of_card_eq_finrank_add_one hd hc
|
import Mathlib.Topology.Separation
import Mathlib.Topology.UniformSpace.Basic
import Mathlib.Topology.UniformSpace.Cauchy
#align_import topology.uniform_space.uniform_convergence from "leanprover-community/mathlib"@"2705404e701abc6b3127da906f40bae062a169c9"
noncomputable section
open Topology Uniformity Filter Set
universe u v w x
variable {α : Type u} {β : Type v} {γ : Type w} {ι : Type x} [UniformSpace β]
variable {F : ι → α → β} {f : α → β} {s s' : Set α} {x : α} {p : Filter ι} {p' : Filter α}
{g : ι → α}
def TendstoUniformlyOnFilter (F : ι → α → β) (f : α → β) (p : Filter ι) (p' : Filter α) :=
∀ u ∈ 𝓤 β, ∀ᶠ n : ι × α in p ×ˢ p', (f n.snd, F n.fst n.snd) ∈ u
#align tendsto_uniformly_on_filter TendstoUniformlyOnFilter
theorem tendstoUniformlyOnFilter_iff_tendsto :
TendstoUniformlyOnFilter F f p p' ↔
Tendsto (fun q : ι × α => (f q.2, F q.1 q.2)) (p ×ˢ p') (𝓤 β) :=
Iff.rfl
#align tendsto_uniformly_on_filter_iff_tendsto tendstoUniformlyOnFilter_iff_tendsto
def TendstoUniformlyOn (F : ι → α → β) (f : α → β) (p : Filter ι) (s : Set α) :=
∀ u ∈ 𝓤 β, ∀ᶠ n in p, ∀ x : α, x ∈ s → (f x, F n x) ∈ u
#align tendsto_uniformly_on TendstoUniformlyOn
theorem tendstoUniformlyOn_iff_tendstoUniformlyOnFilter :
TendstoUniformlyOn F f p s ↔ TendstoUniformlyOnFilter F f p (𝓟 s) := by
simp only [TendstoUniformlyOn, TendstoUniformlyOnFilter]
apply forall₂_congr
simp_rw [eventually_prod_principal_iff]
simp
#align tendsto_uniformly_on_iff_tendsto_uniformly_on_filter tendstoUniformlyOn_iff_tendstoUniformlyOnFilter
alias ⟨TendstoUniformlyOn.tendstoUniformlyOnFilter, TendstoUniformlyOnFilter.tendstoUniformlyOn⟩ :=
tendstoUniformlyOn_iff_tendstoUniformlyOnFilter
#align tendsto_uniformly_on.tendsto_uniformly_on_filter TendstoUniformlyOn.tendstoUniformlyOnFilter
#align tendsto_uniformly_on_filter.tendsto_uniformly_on TendstoUniformlyOnFilter.tendstoUniformlyOn
theorem tendstoUniformlyOn_iff_tendsto {F : ι → α → β} {f : α → β} {p : Filter ι} {s : Set α} :
TendstoUniformlyOn F f p s ↔
Tendsto (fun q : ι × α => (f q.2, F q.1 q.2)) (p ×ˢ 𝓟 s) (𝓤 β) := by
simp [tendstoUniformlyOn_iff_tendstoUniformlyOnFilter, tendstoUniformlyOnFilter_iff_tendsto]
#align tendsto_uniformly_on_iff_tendsto tendstoUniformlyOn_iff_tendsto
def TendstoUniformly (F : ι → α → β) (f : α → β) (p : Filter ι) :=
∀ u ∈ 𝓤 β, ∀ᶠ n in p, ∀ x : α, (f x, F n x) ∈ u
#align tendsto_uniformly TendstoUniformly
-- Porting note: moved from below
theorem tendstoUniformlyOn_univ : TendstoUniformlyOn F f p univ ↔ TendstoUniformly F f p := by
simp [TendstoUniformlyOn, TendstoUniformly]
#align tendsto_uniformly_on_univ tendstoUniformlyOn_univ
theorem tendstoUniformly_iff_tendstoUniformlyOnFilter :
TendstoUniformly F f p ↔ TendstoUniformlyOnFilter F f p ⊤ := by
rw [← tendstoUniformlyOn_univ, tendstoUniformlyOn_iff_tendstoUniformlyOnFilter, principal_univ]
#align tendsto_uniformly_iff_tendsto_uniformly_on_filter tendstoUniformly_iff_tendstoUniformlyOnFilter
theorem TendstoUniformly.tendstoUniformlyOnFilter (h : TendstoUniformly F f p) :
TendstoUniformlyOnFilter F f p ⊤ := by rwa [← tendstoUniformly_iff_tendstoUniformlyOnFilter]
#align tendsto_uniformly.tendsto_uniformly_on_filter TendstoUniformly.tendstoUniformlyOnFilter
theorem tendstoUniformlyOn_iff_tendstoUniformly_comp_coe :
TendstoUniformlyOn F f p s ↔ TendstoUniformly (fun i (x : s) => F i x) (f ∘ (↑)) p :=
forall₂_congr fun u _ => by simp
#align tendsto_uniformly_on_iff_tendsto_uniformly_comp_coe tendstoUniformlyOn_iff_tendstoUniformly_comp_coe
theorem tendstoUniformly_iff_tendsto {F : ι → α → β} {f : α → β} {p : Filter ι} :
TendstoUniformly F f p ↔ Tendsto (fun q : ι × α => (f q.2, F q.1 q.2)) (p ×ˢ ⊤) (𝓤 β) := by
simp [tendstoUniformly_iff_tendstoUniformlyOnFilter, tendstoUniformlyOnFilter_iff_tendsto]
#align tendsto_uniformly_iff_tendsto tendstoUniformly_iff_tendsto
theorem TendstoUniformlyOnFilter.tendsto_at (h : TendstoUniformlyOnFilter F f p p')
(hx : 𝓟 {x} ≤ p') : Tendsto (fun n => F n x) p <| 𝓝 (f x) := by
refine Uniform.tendsto_nhds_right.mpr fun u hu => mem_map.mpr ?_
filter_upwards [(h u hu).curry]
intro i h
simpa using h.filter_mono hx
#align tendsto_uniformly_on_filter.tendsto_at TendstoUniformlyOnFilter.tendsto_at
theorem TendstoUniformlyOn.tendsto_at (h : TendstoUniformlyOn F f p s) {x : α} (hx : x ∈ s) :
Tendsto (fun n => F n x) p <| 𝓝 (f x) :=
h.tendstoUniformlyOnFilter.tendsto_at
(le_principal_iff.mpr <| mem_principal.mpr <| singleton_subset_iff.mpr <| hx)
#align tendsto_uniformly_on.tendsto_at TendstoUniformlyOn.tendsto_at
theorem TendstoUniformly.tendsto_at (h : TendstoUniformly F f p) (x : α) :
Tendsto (fun n => F n x) p <| 𝓝 (f x) :=
h.tendstoUniformlyOnFilter.tendsto_at le_top
#align tendsto_uniformly.tendsto_at TendstoUniformly.tendsto_at
-- Porting note: tendstoUniformlyOn_univ moved up
theorem TendstoUniformlyOnFilter.mono_left {p'' : Filter ι} (h : TendstoUniformlyOnFilter F f p p')
(hp : p'' ≤ p) : TendstoUniformlyOnFilter F f p'' p' := fun u hu =>
(h u hu).filter_mono (p'.prod_mono_left hp)
#align tendsto_uniformly_on_filter.mono_left TendstoUniformlyOnFilter.mono_left
theorem TendstoUniformlyOnFilter.mono_right {p'' : Filter α} (h : TendstoUniformlyOnFilter F f p p')
(hp : p'' ≤ p') : TendstoUniformlyOnFilter F f p p'' := fun u hu =>
(h u hu).filter_mono (p.prod_mono_right hp)
#align tendsto_uniformly_on_filter.mono_right TendstoUniformlyOnFilter.mono_right
theorem TendstoUniformlyOn.mono {s' : Set α} (h : TendstoUniformlyOn F f p s) (h' : s' ⊆ s) :
TendstoUniformlyOn F f p s' :=
tendstoUniformlyOn_iff_tendstoUniformlyOnFilter.mpr
(h.tendstoUniformlyOnFilter.mono_right (le_principal_iff.mpr <| mem_principal.mpr h'))
#align tendsto_uniformly_on.mono TendstoUniformlyOn.mono
theorem TendstoUniformlyOnFilter.congr {F' : ι → α → β} (hf : TendstoUniformlyOnFilter F f p p')
(hff' : ∀ᶠ n : ι × α in p ×ˢ p', F n.fst n.snd = F' n.fst n.snd) :
TendstoUniformlyOnFilter F' f p p' := by
refine fun u hu => ((hf u hu).and hff').mono fun n h => ?_
rw [← h.right]
exact h.left
#align tendsto_uniformly_on_filter.congr TendstoUniformlyOnFilter.congr
theorem TendstoUniformlyOn.congr {F' : ι → α → β} (hf : TendstoUniformlyOn F f p s)
(hff' : ∀ᶠ n in p, Set.EqOn (F n) (F' n) s) : TendstoUniformlyOn F' f p s := by
rw [tendstoUniformlyOn_iff_tendstoUniformlyOnFilter] at hf ⊢
refine hf.congr ?_
rw [eventually_iff] at hff' ⊢
simp only [Set.EqOn] at hff'
simp only [mem_prod_principal, hff', mem_setOf_eq]
#align tendsto_uniformly_on.congr TendstoUniformlyOn.congr
theorem TendstoUniformlyOn.congr_right {g : α → β} (hf : TendstoUniformlyOn F f p s)
(hfg : EqOn f g s) : TendstoUniformlyOn F g p s := fun u hu => by
filter_upwards [hf u hu] with i hi a ha using hfg ha ▸ hi a ha
#align tendsto_uniformly_on.congr_right TendstoUniformlyOn.congr_right
protected theorem TendstoUniformly.tendstoUniformlyOn (h : TendstoUniformly F f p) :
TendstoUniformlyOn F f p s :=
(tendstoUniformlyOn_univ.2 h).mono (subset_univ s)
#align tendsto_uniformly.tendsto_uniformly_on TendstoUniformly.tendstoUniformlyOn
theorem TendstoUniformlyOnFilter.comp (h : TendstoUniformlyOnFilter F f p p') (g : γ → α) :
TendstoUniformlyOnFilter (fun n => F n ∘ g) (f ∘ g) p (p'.comap g) := by
rw [tendstoUniformlyOnFilter_iff_tendsto] at h ⊢
exact h.comp (tendsto_id.prod_map tendsto_comap)
#align tendsto_uniformly_on_filter.comp TendstoUniformlyOnFilter.comp
theorem TendstoUniformlyOn.comp (h : TendstoUniformlyOn F f p s) (g : γ → α) :
TendstoUniformlyOn (fun n => F n ∘ g) (f ∘ g) p (g ⁻¹' s) := by
rw [tendstoUniformlyOn_iff_tendstoUniformlyOnFilter] at h ⊢
simpa [TendstoUniformlyOn, comap_principal] using TendstoUniformlyOnFilter.comp h g
#align tendsto_uniformly_on.comp TendstoUniformlyOn.comp
theorem TendstoUniformly.comp (h : TendstoUniformly F f p) (g : γ → α) :
TendstoUniformly (fun n => F n ∘ g) (f ∘ g) p := by
rw [tendstoUniformly_iff_tendstoUniformlyOnFilter] at h ⊢
simpa [principal_univ, comap_principal] using h.comp g
#align tendsto_uniformly.comp TendstoUniformly.comp
theorem UniformContinuous.comp_tendstoUniformlyOnFilter [UniformSpace γ] {g : β → γ}
(hg : UniformContinuous g) (h : TendstoUniformlyOnFilter F f p p') :
TendstoUniformlyOnFilter (fun i => g ∘ F i) (g ∘ f) p p' := fun _u hu => h _ (hg hu)
#align uniform_continuous.comp_tendsto_uniformly_on_filter UniformContinuous.comp_tendstoUniformlyOnFilter
theorem UniformContinuous.comp_tendstoUniformlyOn [UniformSpace γ] {g : β → γ}
(hg : UniformContinuous g) (h : TendstoUniformlyOn F f p s) :
TendstoUniformlyOn (fun i => g ∘ F i) (g ∘ f) p s := fun _u hu => h _ (hg hu)
#align uniform_continuous.comp_tendsto_uniformly_on UniformContinuous.comp_tendstoUniformlyOn
theorem UniformContinuous.comp_tendstoUniformly [UniformSpace γ] {g : β → γ}
(hg : UniformContinuous g) (h : TendstoUniformly F f p) :
TendstoUniformly (fun i => g ∘ F i) (g ∘ f) p := fun _u hu => h _ (hg hu)
#align uniform_continuous.comp_tendsto_uniformly UniformContinuous.comp_tendstoUniformly
theorem TendstoUniformlyOnFilter.prod_map {ι' α' β' : Type*} [UniformSpace β'] {F' : ι' → α' → β'}
{f' : α' → β'} {q : Filter ι'} {q' : Filter α'} (h : TendstoUniformlyOnFilter F f p p')
(h' : TendstoUniformlyOnFilter F' f' q q') :
TendstoUniformlyOnFilter (fun i : ι × ι' => Prod.map (F i.1) (F' i.2)) (Prod.map f f')
(p ×ˢ q) (p' ×ˢ q') := by
rw [tendstoUniformlyOnFilter_iff_tendsto] at h h' ⊢
rw [uniformity_prod_eq_comap_prod, tendsto_comap_iff, ← map_swap4_prod, tendsto_map'_iff]
convert h.prod_map h' -- seems to be faster than `exact` here
#align tendsto_uniformly_on_filter.prod_map TendstoUniformlyOnFilter.prod_map
theorem TendstoUniformlyOn.prod_map {ι' α' β' : Type*} [UniformSpace β'] {F' : ι' → α' → β'}
{f' : α' → β'} {p' : Filter ι'} {s' : Set α'} (h : TendstoUniformlyOn F f p s)
(h' : TendstoUniformlyOn F' f' p' s') :
TendstoUniformlyOn (fun i : ι × ι' => Prod.map (F i.1) (F' i.2)) (Prod.map f f') (p ×ˢ p')
(s ×ˢ s') := by
rw [tendstoUniformlyOn_iff_tendstoUniformlyOnFilter] at h h' ⊢
simpa only [prod_principal_principal] using h.prod_map h'
#align tendsto_uniformly_on.prod_map TendstoUniformlyOn.prod_map
theorem TendstoUniformly.prod_map {ι' α' β' : Type*} [UniformSpace β'] {F' : ι' → α' → β'}
{f' : α' → β'} {p' : Filter ι'} (h : TendstoUniformly F f p) (h' : TendstoUniformly F' f' p') :
TendstoUniformly (fun i : ι × ι' => Prod.map (F i.1) (F' i.2)) (Prod.map f f') (p ×ˢ p') := by
rw [← tendstoUniformlyOn_univ, ← univ_prod_univ] at *
exact h.prod_map h'
#align tendsto_uniformly.prod_map TendstoUniformly.prod_map
theorem TendstoUniformlyOnFilter.prod {ι' β' : Type*} [UniformSpace β'] {F' : ι' → α → β'}
{f' : α → β'} {q : Filter ι'} (h : TendstoUniformlyOnFilter F f p p')
(h' : TendstoUniformlyOnFilter F' f' q p') :
TendstoUniformlyOnFilter (fun (i : ι × ι') a => (F i.1 a, F' i.2 a)) (fun a => (f a, f' a))
(p ×ˢ q) p' :=
fun u hu => ((h.prod_map h') u hu).diag_of_prod_right
#align tendsto_uniformly_on_filter.prod TendstoUniformlyOnFilter.prod
theorem TendstoUniformlyOn.prod {ι' β' : Type*} [UniformSpace β'] {F' : ι' → α → β'} {f' : α → β'}
{p' : Filter ι'} (h : TendstoUniformlyOn F f p s) (h' : TendstoUniformlyOn F' f' p' s) :
TendstoUniformlyOn (fun (i : ι × ι') a => (F i.1 a, F' i.2 a)) (fun a => (f a, f' a))
(p.prod p') s :=
(congr_arg _ s.inter_self).mp ((h.prod_map h').comp fun a => (a, a))
#align tendsto_uniformly_on.prod TendstoUniformlyOn.prod
theorem TendstoUniformly.prod {ι' β' : Type*} [UniformSpace β'] {F' : ι' → α → β'} {f' : α → β'}
{p' : Filter ι'} (h : TendstoUniformly F f p) (h' : TendstoUniformly F' f' p') :
TendstoUniformly (fun (i : ι × ι') a => (F i.1 a, F' i.2 a)) (fun a => (f a, f' a))
(p ×ˢ p') :=
(h.prod_map h').comp fun a => (a, a)
#align tendsto_uniformly.prod TendstoUniformly.prod
theorem tendsto_prod_filter_iff {c : β} :
Tendsto (↿F) (p ×ˢ p') (𝓝 c) ↔ TendstoUniformlyOnFilter F (fun _ => c) p p' := by
simp_rw [nhds_eq_comap_uniformity, tendsto_comap_iff]
rfl
#align tendsto_prod_filter_iff tendsto_prod_filter_iff
theorem tendsto_prod_principal_iff {c : β} :
Tendsto (↿F) (p ×ˢ 𝓟 s) (𝓝 c) ↔ TendstoUniformlyOn F (fun _ => c) p s := by
rw [tendstoUniformlyOn_iff_tendstoUniformlyOnFilter]
exact tendsto_prod_filter_iff
#align tendsto_prod_principal_iff tendsto_prod_principal_iff
| Mathlib/Topology/UniformSpace/UniformConvergence.lean | 338 | 341 | theorem tendsto_prod_top_iff {c : β} :
Tendsto (↿F) (p ×ˢ ⊤) (𝓝 c) ↔ TendstoUniformly F (fun _ => c) p := by |
rw [tendstoUniformly_iff_tendstoUniformlyOnFilter]
exact tendsto_prod_filter_iff
|
import Mathlib.Order.SuccPred.Basic
import Mathlib.Topology.Order.Basic
import Mathlib.Topology.Metrizable.Uniformity
#align_import topology.instances.discrete from "leanprover-community/mathlib"@"bcfa726826abd57587355b4b5b7e78ad6527b7e4"
open Order Set TopologicalSpace Filter
variable {α : Type*} [TopologicalSpace α]
instance (priority := 100) DiscreteTopology.firstCountableTopology [DiscreteTopology α] :
FirstCountableTopology α where
nhds_generated_countable := by rw [nhds_discrete]; exact isCountablyGenerated_pure
#align discrete_topology.first_countable_topology DiscreteTopology.firstCountableTopology
instance (priority := 100) DiscreteTopology.secondCountableTopology_of_countable
[hd : DiscreteTopology α] [Countable α] : SecondCountableTopology α :=
haveI : ∀ i : α, SecondCountableTopology (↥({i} : Set α)) := fun i =>
{ is_open_generated_countable :=
⟨{univ}, countable_singleton _, by simp only [eq_iff_true_of_subsingleton]⟩ }
secondCountableTopology_of_countable_cover (singletons_open_iff_discrete.mpr hd)
(iUnion_of_singleton α)
#align discrete_topology.second_countable_topology_of_encodable DiscreteTopology.secondCountableTopology_of_countable
@[deprecated DiscreteTopology.secondCountableTopology_of_countable (since := "2024-03-11")]
theorem DiscreteTopology.secondCountableTopology_of_encodable {α : Type*}
[TopologicalSpace α] [DiscreteTopology α] [Countable α] : SecondCountableTopology α :=
DiscreteTopology.secondCountableTopology_of_countable
#align discrete_topology.second_countable_topology_of_countable DiscreteTopology.secondCountableTopology_of_countable
theorem bot_topologicalSpace_eq_generateFrom_of_pred_succOrder [PartialOrder α] [PredOrder α]
[SuccOrder α] [NoMinOrder α] [NoMaxOrder α] :
(⊥ : TopologicalSpace α) = generateFrom { s | ∃ a, s = Ioi a ∨ s = Iio a } := by
refine (eq_bot_of_singletons_open fun a => ?_).symm
have h_singleton_eq_inter : {a} = Iio (succ a) ∩ Ioi (pred a) := by
suffices h_singleton_eq_inter' : {a} = Iic a ∩ Ici a by
rw [h_singleton_eq_inter', ← Ioi_pred, ← Iio_succ]
rw [inter_comm, Ici_inter_Iic, Icc_self a]
rw [h_singleton_eq_inter]
letI := Preorder.topology α
apply IsOpen.inter
· exact isOpen_generateFrom_of_mem ⟨succ a, Or.inr rfl⟩
· exact isOpen_generateFrom_of_mem ⟨pred a, Or.inl rfl⟩
#align bot_topological_space_eq_generate_from_of_pred_succ_order bot_topologicalSpace_eq_generateFrom_of_pred_succOrder
theorem discreteTopology_iff_orderTopology_of_pred_succ' [PartialOrder α] [PredOrder α]
[SuccOrder α] [NoMinOrder α] [NoMaxOrder α] : DiscreteTopology α ↔ OrderTopology α := by
refine ⟨fun h => ⟨?_⟩, fun h => ⟨?_⟩⟩
· rw [h.eq_bot]
exact bot_topologicalSpace_eq_generateFrom_of_pred_succOrder
· rw [h.topology_eq_generate_intervals]
exact bot_topologicalSpace_eq_generateFrom_of_pred_succOrder.symm
#align discrete_topology_iff_order_topology_of_pred_succ' discreteTopology_iff_orderTopology_of_pred_succ'
instance (priority := 100) DiscreteTopology.orderTopology_of_pred_succ' [h : DiscreteTopology α]
[PartialOrder α] [PredOrder α] [SuccOrder α] [NoMinOrder α] [NoMaxOrder α] : OrderTopology α :=
discreteTopology_iff_orderTopology_of_pred_succ'.1 h
#align discrete_topology.order_topology_of_pred_succ' DiscreteTopology.orderTopology_of_pred_succ'
theorem LinearOrder.bot_topologicalSpace_eq_generateFrom [LinearOrder α] [PredOrder α]
[SuccOrder α] : (⊥ : TopologicalSpace α) = generateFrom { s | ∃ a, s = Ioi a ∨ s = Iio a } := by
refine (eq_bot_of_singletons_open fun a => ?_).symm
have h_singleton_eq_inter : {a} = Iic a ∩ Ici a := by rw [inter_comm, Ici_inter_Iic, Icc_self a]
by_cases ha_top : IsTop a
· rw [ha_top.Iic_eq, inter_comm, inter_univ] at h_singleton_eq_inter
by_cases ha_bot : IsBot a
· rw [ha_bot.Ici_eq] at h_singleton_eq_inter
rw [h_singleton_eq_inter]
-- Porting note: Specified instance for `isOpen_univ` explicitly to fix an error.
apply @isOpen_univ _ (generateFrom { s | ∃ a, s = Ioi a ∨ s = Iio a })
· rw [isBot_iff_isMin] at ha_bot
rw [← Ioi_pred_of_not_isMin ha_bot] at h_singleton_eq_inter
rw [h_singleton_eq_inter]
exact isOpen_generateFrom_of_mem ⟨pred a, Or.inl rfl⟩
· rw [isTop_iff_isMax] at ha_top
rw [← Iio_succ_of_not_isMax ha_top] at h_singleton_eq_inter
by_cases ha_bot : IsBot a
· rw [ha_bot.Ici_eq, inter_univ] at h_singleton_eq_inter
rw [h_singleton_eq_inter]
exact isOpen_generateFrom_of_mem ⟨succ a, Or.inr rfl⟩
· rw [isBot_iff_isMin] at ha_bot
rw [← Ioi_pred_of_not_isMin ha_bot] at h_singleton_eq_inter
rw [h_singleton_eq_inter]
-- Porting note: Specified instance for `IsOpen.inter` explicitly to fix an error.
letI := Preorder.topology α
apply IsOpen.inter
· exact isOpen_generateFrom_of_mem ⟨succ a, Or.inr rfl⟩
· exact isOpen_generateFrom_of_mem ⟨pred a, Or.inl rfl⟩
#align linear_order.bot_topological_space_eq_generate_from LinearOrder.bot_topologicalSpace_eq_generateFrom
| Mathlib/Topology/Instances/Discrete.lean | 111 | 117 | theorem discreteTopology_iff_orderTopology_of_pred_succ [LinearOrder α] [PredOrder α]
[SuccOrder α] : DiscreteTopology α ↔ OrderTopology α := by |
refine ⟨fun h => ⟨?_⟩, fun h => ⟨?_⟩⟩
· rw [h.eq_bot]
exact LinearOrder.bot_topologicalSpace_eq_generateFrom
· rw [h.topology_eq_generate_intervals]
exact LinearOrder.bot_topologicalSpace_eq_generateFrom.symm
|
import Mathlib.AlgebraicTopology.FundamentalGroupoid.FundamentalGroup
import Mathlib.GroupTheory.EckmannHilton
import Mathlib.Logic.Equiv.TransferInstance
import Mathlib.Algebra.Group.Ext
#align_import topology.homotopy.homotopy_group from "leanprover-community/mathlib"@"4c3e1721c58ef9087bbc2c8c38b540f70eda2e53"
open scoped unitInterval Topology
open Homeomorph
noncomputable section
scoped[Topology] notation "I^" N => N → I
namespace Cube
def boundary (N : Type*) : Set (I^N) :=
{y | ∃ i, y i = 0 ∨ y i = 1}
#align cube.boundary Cube.boundary
variable {N : Type*} [DecidableEq N]
abbrev splitAt (i : N) : (I^N) ≃ₜ I × I^{ j // j ≠ i } :=
funSplitAt I i
#align cube.split_at Cube.splitAt
abbrev insertAt (i : N) : (I × I^{ j // j ≠ i }) ≃ₜ I^N :=
(funSplitAt I i).symm
#align cube.insert_at Cube.insertAt
| Mathlib/Topology/Homotopy/HomotopyGroup.lean | 74 | 78 | theorem insertAt_boundary (i : N) {t₀ : I} {t}
(H : (t₀ = 0 ∨ t₀ = 1) ∨ t ∈ boundary { j // j ≠ i }) : insertAt i ⟨t₀, t⟩ ∈ boundary N := by |
obtain H | ⟨j, H⟩ := H
· use i; rwa [funSplitAt_symm_apply, dif_pos rfl]
· use j; rwa [funSplitAt_symm_apply, dif_neg j.prop, Subtype.coe_eta]
|
import Mathlib.Data.List.Infix
#align_import data.list.rdrop from "leanprover-community/mathlib"@"26f081a2fb920140ed5bc5cc5344e84bcc7cb2b2"
-- Make sure we don't import algebra
assert_not_exists Monoid
variable {α : Type*} (p : α → Bool) (l : List α) (n : ℕ)
namespace List
def rdrop : List α :=
l.take (l.length - n)
#align list.rdrop List.rdrop
@[simp]
theorem rdrop_nil : rdrop ([] : List α) n = [] := by simp [rdrop]
#align list.rdrop_nil List.rdrop_nil
@[simp]
theorem rdrop_zero : rdrop l 0 = l := by simp [rdrop]
#align list.rdrop_zero List.rdrop_zero
theorem rdrop_eq_reverse_drop_reverse : l.rdrop n = reverse (l.reverse.drop n) := by
rw [rdrop]
induction' l using List.reverseRecOn with xs x IH generalizing n
· simp
· cases n
· simp [take_append]
· simp [take_append_eq_append_take, IH]
#align list.rdrop_eq_reverse_drop_reverse List.rdrop_eq_reverse_drop_reverse
@[simp]
theorem rdrop_concat_succ (x : α) : rdrop (l ++ [x]) (n + 1) = rdrop l n := by
simp [rdrop_eq_reverse_drop_reverse]
#align list.rdrop_concat_succ List.rdrop_concat_succ
def rtake : List α :=
l.drop (l.length - n)
#align list.rtake List.rtake
@[simp]
theorem rtake_nil : rtake ([] : List α) n = [] := by simp [rtake]
#align list.rtake_nil List.rtake_nil
@[simp]
theorem rtake_zero : rtake l 0 = [] := by simp [rtake]
#align list.rtake_zero List.rtake_zero
theorem rtake_eq_reverse_take_reverse : l.rtake n = reverse (l.reverse.take n) := by
rw [rtake]
induction' l using List.reverseRecOn with xs x IH generalizing n
· simp
· cases n
· exact drop_length _
· simp [drop_append_eq_append_drop, IH]
#align list.rtake_eq_reverse_take_reverse List.rtake_eq_reverse_take_reverse
@[simp]
theorem rtake_concat_succ (x : α) : rtake (l ++ [x]) (n + 1) = rtake l n ++ [x] := by
simp [rtake_eq_reverse_take_reverse]
#align list.rtake_concat_succ List.rtake_concat_succ
def rdropWhile : List α :=
reverse (l.reverse.dropWhile p)
#align list.rdrop_while List.rdropWhile
@[simp]
theorem rdropWhile_nil : rdropWhile p ([] : List α) = [] := by simp [rdropWhile, dropWhile]
#align list.rdrop_while_nil List.rdropWhile_nil
theorem rdropWhile_concat (x : α) :
rdropWhile p (l ++ [x]) = if p x then rdropWhile p l else l ++ [x] := by
simp only [rdropWhile, dropWhile, reverse_append, reverse_singleton, singleton_append]
split_ifs with h <;> simp [h]
#align list.rdrop_while_concat List.rdropWhile_concat
@[simp]
theorem rdropWhile_concat_pos (x : α) (h : p x) : rdropWhile p (l ++ [x]) = rdropWhile p l := by
rw [rdropWhile_concat, if_pos h]
#align list.rdrop_while_concat_pos List.rdropWhile_concat_pos
@[simp]
theorem rdropWhile_concat_neg (x : α) (h : ¬p x) : rdropWhile p (l ++ [x]) = l ++ [x] := by
rw [rdropWhile_concat, if_neg h]
#align list.rdrop_while_concat_neg List.rdropWhile_concat_neg
theorem rdropWhile_singleton (x : α) : rdropWhile p [x] = if p x then [] else [x] := by
rw [← nil_append [x], rdropWhile_concat, rdropWhile_nil]
#align list.rdrop_while_singleton List.rdropWhile_singleton
theorem rdropWhile_last_not (hl : l.rdropWhile p ≠ []) : ¬p ((rdropWhile p l).getLast hl) := by
simp_rw [rdropWhile]
rw [getLast_reverse]
exact dropWhile_nthLe_zero_not _ _ _
#align list.rdrop_while_last_not List.rdropWhile_last_not
theorem rdropWhile_prefix : l.rdropWhile p <+: l := by
rw [← reverse_suffix, rdropWhile, reverse_reverse]
exact dropWhile_suffix _
#align list.rdrop_while_prefix List.rdropWhile_prefix
variable {p} {l}
@[simp]
theorem rdropWhile_eq_nil_iff : rdropWhile p l = [] ↔ ∀ x ∈ l, p x := by simp [rdropWhile]
#align list.rdrop_while_eq_nil_iff List.rdropWhile_eq_nil_iff
-- it is in this file because it requires `List.Infix`
@[simp]
theorem dropWhile_eq_self_iff : dropWhile p l = l ↔ ∀ hl : 0 < l.length, ¬p (l.get ⟨0, hl⟩) := by
cases' l with hd tl
· simp only [dropWhile, true_iff]
intro h
by_contra
rwa [length_nil, lt_self_iff_false] at h
· rw [dropWhile]
refine ⟨fun h => ?_, fun h => ?_⟩
· intro _ H
rw [get] at H
refine (cons_ne_self hd tl) (Sublist.antisymm ?_ (sublist_cons _ _))
rw [← h]
simp only [H]
exact List.IsSuffix.sublist (dropWhile_suffix p)
· have := h (by simp only [length, Nat.succ_pos])
rw [get] at this
simp_rw [this]
#align list.drop_while_eq_self_iff List.dropWhile_eq_self_iff
@[simp]
theorem rdropWhile_eq_self_iff : rdropWhile p l = l ↔ ∀ hl : l ≠ [], ¬p (l.getLast hl) := by
simp only [rdropWhile, reverse_eq_iff, dropWhile_eq_self_iff, getLast_eq_get]
refine ⟨fun h hl => ?_, fun h hl => ?_⟩
· rw [← length_pos, ← length_reverse] at hl
have := h hl
rwa [get_reverse'] at this
· rw [length_reverse, length_pos] at hl
have := h hl
rwa [get_reverse']
#align list.rdrop_while_eq_self_iff List.rdropWhile_eq_self_iff
variable (p) (l)
theorem dropWhile_idempotent : dropWhile p (dropWhile p l) = dropWhile p l := by
simp only [dropWhile_eq_self_iff]
exact fun h => dropWhile_nthLe_zero_not p l h
#align list.drop_while_idempotent List.dropWhile_idempotent
theorem rdropWhile_idempotent : rdropWhile p (rdropWhile p l) = rdropWhile p l :=
rdropWhile_eq_self_iff.mpr (rdropWhile_last_not _ _)
#align list.rdrop_while_idempotent List.rdropWhile_idempotent
def rtakeWhile : List α :=
reverse (l.reverse.takeWhile p)
#align list.rtake_while List.rtakeWhile
@[simp]
theorem rtakeWhile_nil : rtakeWhile p ([] : List α) = [] := by simp [rtakeWhile, takeWhile]
#align list.rtake_while_nil List.rtakeWhile_nil
| Mathlib/Data/List/DropRight.lean | 198 | 201 | theorem rtakeWhile_concat (x : α) :
rtakeWhile p (l ++ [x]) = if p x then rtakeWhile p l ++ [x] else [] := by |
simp only [rtakeWhile, takeWhile, reverse_append, reverse_singleton, singleton_append]
split_ifs with h <;> simp [h]
|
import Mathlib.Algebra.Algebra.RestrictScalars
import Mathlib.Algebra.Algebra.Subalgebra.Basic
import Mathlib.LinearAlgebra.Quotient
import Mathlib.LinearAlgebra.StdBasis
import Mathlib.GroupTheory.Finiteness
import Mathlib.RingTheory.Ideal.Maps
import Mathlib.RingTheory.Nilpotent.Defs
#align_import ring_theory.finiteness from "leanprover-community/mathlib"@"c813ed7de0f5115f956239124e9b30f3a621966f"
open Function (Surjective)
namespace Submodule
variable {R : Type*} {M : Type*} [Semiring R] [AddCommMonoid M] [Module R M]
open Set
def FG (N : Submodule R M) : Prop :=
∃ S : Finset M, Submodule.span R ↑S = N
#align submodule.fg Submodule.FG
theorem fg_def {N : Submodule R M} : N.FG ↔ ∃ S : Set M, S.Finite ∧ span R S = N :=
⟨fun ⟨t, h⟩ => ⟨_, Finset.finite_toSet t, h⟩, by
rintro ⟨t', h, rfl⟩
rcases Finite.exists_finset_coe h with ⟨t, rfl⟩
exact ⟨t, rfl⟩⟩
#align submodule.fg_def Submodule.fg_def
theorem fg_iff_addSubmonoid_fg (P : Submodule ℕ M) : P.FG ↔ P.toAddSubmonoid.FG :=
⟨fun ⟨S, hS⟩ => ⟨S, by simpa [← span_nat_eq_addSubmonoid_closure] using hS⟩, fun ⟨S, hS⟩ =>
⟨S, by simpa [← span_nat_eq_addSubmonoid_closure] using hS⟩⟩
#align submodule.fg_iff_add_submonoid_fg Submodule.fg_iff_addSubmonoid_fg
theorem fg_iff_add_subgroup_fg {G : Type*} [AddCommGroup G] (P : Submodule ℤ G) :
P.FG ↔ P.toAddSubgroup.FG :=
⟨fun ⟨S, hS⟩ => ⟨S, by simpa [← span_int_eq_addSubgroup_closure] using hS⟩, fun ⟨S, hS⟩ =>
⟨S, by simpa [← span_int_eq_addSubgroup_closure] using hS⟩⟩
#align submodule.fg_iff_add_subgroup_fg Submodule.fg_iff_add_subgroup_fg
theorem fg_iff_exists_fin_generating_family {N : Submodule R M} :
N.FG ↔ ∃ (n : ℕ) (s : Fin n → M), span R (range s) = N := by
rw [fg_def]
constructor
· rintro ⟨S, Sfin, hS⟩
obtain ⟨n, f, rfl⟩ := Sfin.fin_embedding
exact ⟨n, f, hS⟩
· rintro ⟨n, s, hs⟩
exact ⟨range s, finite_range s, hs⟩
#align submodule.fg_iff_exists_fin_generating_family Submodule.fg_iff_exists_fin_generating_family
| Mathlib/RingTheory/Finiteness.lean | 82 | 134 | theorem exists_sub_one_mem_and_smul_eq_zero_of_fg_of_le_smul {R : Type*} [CommRing R] {M : Type*}
[AddCommGroup M] [Module R M] (I : Ideal R) (N : Submodule R M) (hn : N.FG) (hin : N ≤ I • N) :
∃ r : R, r - 1 ∈ I ∧ ∀ n ∈ N, r • n = (0 : M) := by |
rw [fg_def] at hn
rcases hn with ⟨s, hfs, hs⟩
have : ∃ r : R, r - 1 ∈ I ∧ N ≤ (I • span R s).comap (LinearMap.lsmul R M r) ∧ s ⊆ N := by
refine ⟨1, ?_, ?_, ?_⟩
· rw [sub_self]
exact I.zero_mem
· rw [hs]
intro n hn
rw [mem_comap]
change (1 : R) • n ∈ I • N
rw [one_smul]
exact hin hn
· rw [← span_le, hs]
clear hin hs
revert this
refine Set.Finite.dinduction_on _ hfs (fun H => ?_) @fun i s _ _ ih H => ?_
· rcases H with ⟨r, hr1, hrn, _⟩
refine ⟨r, hr1, fun n hn => ?_⟩
specialize hrn hn
rwa [mem_comap, span_empty, smul_bot, mem_bot] at hrn
apply ih
rcases H with ⟨r, hr1, hrn, hs⟩
rw [← Set.singleton_union, span_union, smul_sup] at hrn
rw [Set.insert_subset_iff] at hs
have : ∃ c : R, c - 1 ∈ I ∧ c • i ∈ I • span R s := by
specialize hrn hs.1
rw [mem_comap, mem_sup] at hrn
rcases hrn with ⟨y, hy, z, hz, hyz⟩
dsimp at hyz
rw [mem_smul_span_singleton] at hy
rcases hy with ⟨c, hci, rfl⟩
use r - c
constructor
· rw [sub_right_comm]
exact I.sub_mem hr1 hci
· rw [sub_smul, ← hyz, add_sub_cancel_left]
exact hz
rcases this with ⟨c, hc1, hci⟩
refine ⟨c * r, ?_, ?_, hs.2⟩
· simpa only [mul_sub, mul_one, sub_add_sub_cancel] using I.add_mem (I.mul_mem_left c hr1) hc1
· intro n hn
specialize hrn hn
rw [mem_comap, mem_sup] at hrn
rcases hrn with ⟨y, hy, z, hz, hyz⟩
dsimp at hyz
rw [mem_smul_span_singleton] at hy
rcases hy with ⟨d, _, rfl⟩
simp only [mem_comap, LinearMap.lsmul_apply]
rw [mul_smul, ← hyz, smul_add, smul_smul, mul_comm, mul_smul]
exact add_mem (smul_mem _ _ hci) (smul_mem _ _ hz)
|
import Mathlib.MeasureTheory.Measure.ProbabilityMeasure
import Mathlib.MeasureTheory.Measure.Lebesgue.Basic
import Mathlib.MeasureTheory.Integral.Layercake
import Mathlib.MeasureTheory.Integral.BoundedContinuousFunction
#align_import measure_theory.measure.portmanteau from "leanprover-community/mathlib"@"fd5edc43dc4f10b85abfe544b88f82cf13c5f844"
noncomputable section
open MeasureTheory Set Filter BoundedContinuousFunction
open scoped Topology ENNReal NNReal BoundedContinuousFunction
namespace MeasureTheory
section LimsupClosedLEAndLELiminfOpen
variable {Ω : Type*} [MeasurableSpace Ω]
| Mathlib/MeasureTheory/Measure/Portmanteau.lean | 105 | 123 | theorem le_measure_compl_liminf_of_limsup_measure_le {ι : Type*} {L : Filter ι} {μ : Measure Ω}
{μs : ι → Measure Ω} [IsProbabilityMeasure μ] [∀ i, IsProbabilityMeasure (μs i)] {E : Set Ω}
(E_mble : MeasurableSet E) (h : (L.limsup fun i => μs i E) ≤ μ E) :
μ Eᶜ ≤ L.liminf fun i => μs i Eᶜ := by |
rcases L.eq_or_neBot with rfl | hne
· simp only [liminf_bot, le_top]
have meas_Ec : μ Eᶜ = 1 - μ E := by
simpa only [measure_univ] using measure_compl E_mble (measure_lt_top μ E).ne
have meas_i_Ec : ∀ i, μs i Eᶜ = 1 - μs i E := by
intro i
simpa only [measure_univ] using measure_compl E_mble (measure_lt_top (μs i) E).ne
simp_rw [meas_Ec, meas_i_Ec]
have obs :
(L.liminf fun i : ι => 1 - μs i E) = L.liminf ((fun x => 1 - x) ∘ fun i : ι => μs i E) := rfl
rw [obs]
have := antitone_const_tsub.map_limsup_of_continuousAt (F := L)
(fun i => μs i E) (ENNReal.continuous_sub_left ENNReal.one_ne_top).continuousAt
simp_rw [← this]
exact antitone_const_tsub h
|
import Batteries.Data.Rat.Basic
import Batteries.Tactic.SeqFocus
namespace Rat
theorem ext : {p q : Rat} → p.num = q.num → p.den = q.den → p = q
| ⟨_,_,_,_⟩, ⟨_,_,_,_⟩, rfl, rfl => rfl
@[simp] theorem mk_den_one {r : Int} :
⟨r, 1, Nat.one_ne_zero, (Nat.coprime_one_right _)⟩ = (r : Rat) := rfl
@[simp] theorem zero_num : (0 : Rat).num = 0 := rfl
@[simp] theorem zero_den : (0 : Rat).den = 1 := rfl
@[simp] theorem one_num : (1 : Rat).num = 1 := rfl
@[simp] theorem one_den : (1 : Rat).den = 1 := rfl
@[simp] theorem maybeNormalize_eq {num den g} (den_nz reduced) :
maybeNormalize num den g den_nz reduced =
{ num := num.div g, den := den / g, den_nz, reduced } := by
unfold maybeNormalize; split
· subst g; simp
· rfl
theorem normalize.reduced' {num : Int} {den g : Nat} (den_nz : den ≠ 0)
(e : g = num.natAbs.gcd den) : (num / g).natAbs.Coprime (den / g) := by
rw [← Int.div_eq_ediv_of_dvd (e ▸ Int.ofNat_dvd_left.2 (Nat.gcd_dvd_left ..))]
exact normalize.reduced den_nz e
theorem normalize_eq {num den} (den_nz) : normalize num den den_nz =
{ num := num / num.natAbs.gcd den
den := den / num.natAbs.gcd den
den_nz := normalize.den_nz den_nz rfl
reduced := normalize.reduced' den_nz rfl } := by
simp only [normalize, maybeNormalize_eq,
Int.div_eq_ediv_of_dvd (Int.ofNat_dvd_left.2 (Nat.gcd_dvd_left ..))]
@[simp] theorem normalize_zero (nz) : normalize 0 d nz = 0 := by
simp [normalize, Int.zero_div, Int.natAbs_zero, Nat.div_self (Nat.pos_of_ne_zero nz)]; rfl
theorem mk_eq_normalize (num den nz c) : ⟨num, den, nz, c⟩ = normalize num den nz := by
simp [normalize_eq, c.gcd_eq_one]
theorem normalize_self (r : Rat) : normalize r.num r.den r.den_nz = r := (mk_eq_normalize ..).symm
theorem normalize_mul_left {a : Nat} (d0 : d ≠ 0) (a0 : a ≠ 0) :
normalize (↑a * n) (a * d) (Nat.mul_ne_zero a0 d0) = normalize n d d0 := by
simp [normalize_eq, mk'.injEq, Int.natAbs_mul, Nat.gcd_mul_left,
Nat.mul_div_mul_left _ _ (Nat.pos_of_ne_zero a0), Int.ofNat_mul,
Int.mul_ediv_mul_of_pos _ _ (Int.ofNat_pos.2 <| Nat.pos_of_ne_zero a0)]
theorem normalize_mul_right {a : Nat} (d0 : d ≠ 0) (a0 : a ≠ 0) :
normalize (n * a) (d * a) (Nat.mul_ne_zero d0 a0) = normalize n d d0 := by
rw [← normalize_mul_left (d0 := d0) a0]; congr 1 <;> [apply Int.mul_comm; apply Nat.mul_comm]
theorem normalize_eq_iff (z₁ : d₁ ≠ 0) (z₂ : d₂ ≠ 0) :
normalize n₁ d₁ z₁ = normalize n₂ d₂ z₂ ↔ n₁ * d₂ = n₂ * d₁ := by
constructor <;> intro h
· simp only [normalize_eq, mk'.injEq] at h
have' hn₁ := Int.ofNat_dvd_left.2 <| Nat.gcd_dvd_left n₁.natAbs d₁
have' hn₂ := Int.ofNat_dvd_left.2 <| Nat.gcd_dvd_left n₂.natAbs d₂
have' hd₁ := Int.ofNat_dvd.2 <| Nat.gcd_dvd_right n₁.natAbs d₁
have' hd₂ := Int.ofNat_dvd.2 <| Nat.gcd_dvd_right n₂.natAbs d₂
rw [← Int.ediv_mul_cancel (Int.dvd_trans hd₂ (Int.dvd_mul_left ..)),
Int.mul_ediv_assoc _ hd₂, ← Int.ofNat_ediv, ← h.2, Int.ofNat_ediv,
← Int.mul_ediv_assoc _ hd₁, Int.mul_ediv_assoc' _ hn₁,
Int.mul_right_comm, h.1, Int.ediv_mul_cancel hn₂]
· rw [← normalize_mul_right _ z₂, ← normalize_mul_left z₂ z₁, Int.mul_comm d₁, h]
| .lake/packages/batteries/Batteries/Data/Rat/Lemmas.lean | 76 | 82 | theorem maybeNormalize_eq_normalize {num : Int} {den g : Nat} (den_nz reduced)
(hn : ↑g ∣ num) (hd : g ∣ den) :
maybeNormalize num den g den_nz reduced = normalize num den (mt (by simp [·]) den_nz) := by |
simp only [maybeNormalize_eq, mk_eq_normalize, Int.div_eq_ediv_of_dvd hn]
have : g ≠ 0 := mt (by simp [·]) den_nz
rw [← normalize_mul_right _ this, Int.ediv_mul_cancel hn]
congr 1; exact Nat.div_mul_cancel hd
|
import Mathlib.Analysis.BoxIntegral.Partition.Basic
#align_import analysis.box_integral.partition.split from "leanprover-community/mathlib"@"6ca1a09bc9aa75824bf97388c9e3b441fc4ccf3f"
noncomputable section
open scoped Classical
open Filter
open Function Set Filter
namespace BoxIntegral
variable {ι M : Type*} {n : ℕ}
namespace Box
variable {I : Box ι} {i : ι} {x : ℝ} {y : ι → ℝ}
def splitLower (I : Box ι) (i : ι) (x : ℝ) : WithBot (Box ι) :=
mk' I.lower (update I.upper i (min x (I.upper i)))
#align box_integral.box.split_lower BoxIntegral.Box.splitLower
@[simp]
| Mathlib/Analysis/BoxIntegral/Partition/Split.lean | 65 | 70 | theorem coe_splitLower : (splitLower I i x : Set (ι → ℝ)) = ↑I ∩ { y | y i ≤ x } := by |
rw [splitLower, coe_mk']
ext y
simp only [mem_univ_pi, mem_Ioc, mem_inter_iff, mem_coe, mem_setOf_eq, forall_and, ← Pi.le_def,
le_update_iff, le_min_iff, and_assoc, and_forall_ne (p := fun j => y j ≤ upper I j) i, mem_def]
rw [and_comm (a := y i ≤ x)]
|
import Mathlib.Data.Set.Image
import Mathlib.Data.Set.Lattice
#align_import data.set.sigma from "leanprover-community/mathlib"@"2258b40dacd2942571c8ce136215350c702dc78f"
namespace Set
variable {ι ι' : Type*} {α β : ι → Type*} {s s₁ s₂ : Set ι} {t t₁ t₂ : ∀ i, Set (α i)}
{u : Set (Σ i, α i)} {x : Σ i, α i} {i j : ι} {a : α i}
@[simp]
theorem range_sigmaMk (i : ι) : range (Sigma.mk i : α i → Sigma α) = Sigma.fst ⁻¹' {i} := by
apply Subset.antisymm
· rintro _ ⟨b, rfl⟩
simp
· rintro ⟨x, y⟩ (rfl | _)
exact mem_range_self y
#align set.range_sigma_mk Set.range_sigmaMk
theorem preimage_image_sigmaMk_of_ne (h : i ≠ j) (s : Set (α j)) :
Sigma.mk i ⁻¹' (Sigma.mk j '' s) = ∅ := by
ext x
simp [h.symm]
#align set.preimage_image_sigma_mk_of_ne Set.preimage_image_sigmaMk_of_ne
theorem image_sigmaMk_preimage_sigmaMap_subset {β : ι' → Type*} (f : ι → ι')
(g : ∀ i, α i → β (f i)) (i : ι) (s : Set (β (f i))) :
Sigma.mk i '' (g i ⁻¹' s) ⊆ Sigma.map f g ⁻¹' (Sigma.mk (f i) '' s) :=
image_subset_iff.2 fun x hx ↦ ⟨g i x, hx, rfl⟩
#align set.image_sigma_mk_preimage_sigma_map_subset Set.image_sigmaMk_preimage_sigmaMap_subset
theorem image_sigmaMk_preimage_sigmaMap {β : ι' → Type*} {f : ι → ι'} (hf : Function.Injective f)
(g : ∀ i, α i → β (f i)) (i : ι) (s : Set (β (f i))) :
Sigma.mk i '' (g i ⁻¹' s) = Sigma.map f g ⁻¹' (Sigma.mk (f i) '' s) := by
refine (image_sigmaMk_preimage_sigmaMap_subset f g i s).antisymm ?_
rintro ⟨j, x⟩ ⟨y, hys, hxy⟩
simp only [hf.eq_iff, Sigma.map, Sigma.ext_iff] at hxy
rcases hxy with ⟨rfl, hxy⟩; rw [heq_iff_eq] at hxy; subst y
exact ⟨x, hys, rfl⟩
#align set.image_sigma_mk_preimage_sigma_map Set.image_sigmaMk_preimage_sigmaMap
protected def sigma (s : Set ι) (t : ∀ i, Set (α i)) : Set (Σ i, α i) := {x | x.1 ∈ s ∧ x.2 ∈ t x.1}
#align set.sigma Set.sigma
@[simp] theorem mem_sigma_iff : x ∈ s.sigma t ↔ x.1 ∈ s ∧ x.2 ∈ t x.1 := Iff.rfl
#align set.mem_sigma_iff Set.mem_sigma_iff
theorem mk_sigma_iff : (⟨i, a⟩ : Σ i, α i) ∈ s.sigma t ↔ i ∈ s ∧ a ∈ t i := Iff.rfl
#align set.mk_sigma_iff Set.mk_sigma_iff
theorem mk_mem_sigma (hi : i ∈ s) (ha : a ∈ t i) : (⟨i, a⟩ : Σ i, α i) ∈ s.sigma t := ⟨hi, ha⟩
#align set.mk_mem_sigma Set.mk_mem_sigma
theorem sigma_mono (hs : s₁ ⊆ s₂) (ht : ∀ i, t₁ i ⊆ t₂ i) : s₁.sigma t₁ ⊆ s₂.sigma t₂ := fun _ hx ↦
⟨hs hx.1, ht _ hx.2⟩
#align set.sigma_mono Set.sigma_mono
theorem sigma_subset_iff :
s.sigma t ⊆ u ↔ ∀ ⦃i⦄, i ∈ s → ∀ ⦃a⦄, a ∈ t i → (⟨i, a⟩ : Σ i, α i) ∈ u :=
⟨fun h _ hi _ ha ↦ h <| mk_mem_sigma hi ha, fun h _ ha ↦ h ha.1 ha.2⟩
#align set.sigma_subset_iff Set.sigma_subset_iff
theorem forall_sigma_iff {p : (Σ i, α i) → Prop} :
(∀ x ∈ s.sigma t, p x) ↔ ∀ ⦃i⦄, i ∈ s → ∀ ⦃a⦄, a ∈ t i → p ⟨i, a⟩ := sigma_subset_iff
#align set.forall_sigma_iff Set.forall_sigma_iff
theorem exists_sigma_iff {p : (Σi, α i) → Prop} :
(∃ x ∈ s.sigma t, p x) ↔ ∃ i ∈ s, ∃ a ∈ t i, p ⟨i, a⟩ :=
⟨fun ⟨⟨i, a⟩, ha, h⟩ ↦ ⟨i, ha.1, a, ha.2, h⟩, fun ⟨i, hi, a, ha, h⟩ ↦ ⟨⟨i, a⟩, ⟨hi, ha⟩, h⟩⟩
#align set.exists_sigma_iff Set.exists_sigma_iff
@[simp] theorem sigma_empty : s.sigma (fun i ↦ (∅ : Set (α i))) = ∅ := ext fun _ ↦ and_false_iff _
#align set.sigma_empty Set.sigma_empty
@[simp] theorem empty_sigma : (∅ : Set ι).sigma t = ∅ := ext fun _ ↦ false_and_iff _
#align set.empty_sigma Set.empty_sigma
theorem univ_sigma_univ : (@univ ι).sigma (fun _ ↦ @univ (α i)) = univ := ext fun _ ↦ true_and_iff _
#align set.univ_sigma_univ Set.univ_sigma_univ
@[simp]
theorem sigma_univ : s.sigma (fun _ ↦ univ : ∀ i, Set (α i)) = Sigma.fst ⁻¹' s :=
ext fun _ ↦ and_true_iff _
#align set.sigma_univ Set.sigma_univ
@[simp]
theorem singleton_sigma : ({i} : Set ι).sigma t = Sigma.mk i '' t i :=
ext fun x ↦ by
constructor
· obtain ⟨j, a⟩ := x
rintro ⟨rfl : j = i, ha⟩
exact mem_image_of_mem _ ha
· rintro ⟨b, hb, rfl⟩
exact ⟨rfl, hb⟩
#align set.singleton_sigma Set.singleton_sigma
@[simp]
theorem sigma_singleton {a : ∀ i, α i} :
s.sigma (fun i ↦ ({a i} : Set (α i))) = (fun i ↦ Sigma.mk i <| a i) '' s := by
ext ⟨x, y⟩
simp [and_left_comm, eq_comm]
#align set.sigma_singleton Set.sigma_singleton
theorem singleton_sigma_singleton {a : ∀ i, α i} :
(({i} : Set ι).sigma fun i ↦ ({a i} : Set (α i))) = {⟨i, a i⟩} := by
rw [sigma_singleton, image_singleton]
#align set.singleton_sigma_singleton Set.singleton_sigma_singleton
@[simp]
theorem union_sigma : (s₁ ∪ s₂).sigma t = s₁.sigma t ∪ s₂.sigma t := ext fun _ ↦ or_and_right
#align set.union_sigma Set.union_sigma
@[simp]
theorem sigma_union : s.sigma (fun i ↦ t₁ i ∪ t₂ i) = s.sigma t₁ ∪ s.sigma t₂ :=
ext fun _ ↦ and_or_left
#align set.sigma_union Set.sigma_union
theorem sigma_inter_sigma : s₁.sigma t₁ ∩ s₂.sigma t₂ = (s₁ ∩ s₂).sigma fun i ↦ t₁ i ∩ t₂ i := by
ext ⟨x, y⟩
simp [and_assoc, and_left_comm]
#align set.sigma_inter_sigma Set.sigma_inter_sigma
variable {β : Type*} [CompleteLattice β]
theorem _root_.biSup_sigma (s : Set ι) (t : ∀ i, Set (α i)) (f : Sigma α → β) :
⨆ ij ∈ s.sigma t, f ij = ⨆ (i ∈ s) (j ∈ t i), f ⟨i, j⟩ :=
eq_of_forall_ge_iff fun _ ↦ ⟨by simp_all, by simp_all⟩
theorem _root_.biSup_sigma' (s : Set ι) (t : ∀ i, Set (α i)) (f : ∀ i, α i → β) :
⨆ (i ∈ s) (j ∈ t i), f i j = ⨆ ij ∈ s.sigma t, f ij.fst ij.snd :=
Eq.symm (biSup_sigma _ _ _)
theorem _root_.biInf_sigma (s : Set ι) (t : ∀ i, Set (α i)) (f : Sigma α → β) :
⨅ ij ∈ s.sigma t, f ij = ⨅ (i ∈ s) (j ∈ t i), f ⟨i, j⟩ :=
biSup_sigma (β := βᵒᵈ) _ _ _
theorem _root_.biInf_sigma' (s : Set ι) (t : ∀ i, Set (α i)) (f : ∀ i, α i → β) :
⨅ (i ∈ s) (j ∈ t i), f i j = ⨅ ij ∈ s.sigma t, f ij.fst ij.snd :=
Eq.symm (biInf_sigma _ _ _)
variable {β : Type*}
theorem biUnion_sigma (s : Set ι) (t : ∀ i, Set (α i)) (f : Sigma α → Set β) :
⋃ ij ∈ s.sigma t, f ij = ⋃ i ∈ s, ⋃ j ∈ t i, f ⟨i, j⟩ :=
biSup_sigma _ _ _
theorem biUnion_sigma' (s : Set ι) (t : ∀ i, Set (α i)) (f : ∀ i, α i → Set β) :
⋃ i ∈ s, ⋃ j ∈ t i, f i j = ⋃ ij ∈ s.sigma t, f ij.fst ij.snd :=
biSup_sigma' _ _ _
theorem biInter_sigma (s : Set ι) (t : ∀ i, Set (α i)) (f : Sigma α → Set β) :
⋂ ij ∈ s.sigma t, f ij = ⋂ i ∈ s, ⋂ j ∈ t i, f ⟨i, j⟩ :=
biInf_sigma _ _ _
theorem biInter_sigma' (s : Set ι) (t : ∀ i, Set (α i)) (f : ∀ i, α i → Set β) :
⋂ i ∈ s, ⋂ j ∈ t i, f i j = ⋂ ij ∈ s.sigma t, f ij.fst ij.snd :=
biInf_sigma' _ _ _
variable {β : ι → Type*}
theorem insert_sigma : (insert i s).sigma t = Sigma.mk i '' t i ∪ s.sigma t := by
rw [insert_eq, union_sigma, singleton_sigma]
exact a
#align set.insert_sigma Set.insert_sigma
| Mathlib/Data/Set/Sigma.lean | 179 | 181 | theorem sigma_insert {a : ∀ i, α i} :
s.sigma (fun i ↦ insert (a i) (t i)) = (fun i ↦ ⟨i, a i⟩) '' s ∪ s.sigma t := by |
simp_rw [insert_eq, sigma_union, sigma_singleton]
|
import Mathlib.RingTheory.Localization.FractionRing
import Mathlib.RingTheory.Localization.Ideal
import Mathlib.RingTheory.Noetherian
#align_import ring_theory.localization.submodule from "leanprover-community/mathlib"@"1ebb20602a8caef435ce47f6373e1aa40851a177"
variable {R : Type*} [CommRing R] (M : Submonoid R) (S : Type*) [CommRing S]
variable [Algebra R S] {P : Type*} [CommRing P]
namespace IsLocalization
-- This was previously a `hasCoe` instance, but if `S = R` then this will loop.
-- It could be a `hasCoeT` instance, but we keep it explicit here to avoid slowing down
-- the rest of the library.
def coeSubmodule (I : Ideal R) : Submodule R S :=
Submodule.map (Algebra.linearMap R S) I
#align is_localization.coe_submodule IsLocalization.coeSubmodule
theorem mem_coeSubmodule (I : Ideal R) {x : S} :
x ∈ coeSubmodule S I ↔ ∃ y : R, y ∈ I ∧ algebraMap R S y = x :=
Iff.rfl
#align is_localization.mem_coe_submodule IsLocalization.mem_coeSubmodule
theorem coeSubmodule_mono {I J : Ideal R} (h : I ≤ J) : coeSubmodule S I ≤ coeSubmodule S J :=
Submodule.map_mono h
#align is_localization.coe_submodule_mono IsLocalization.coeSubmodule_mono
@[simp]
| Mathlib/RingTheory/Localization/Submodule.lean | 48 | 49 | theorem coeSubmodule_bot : coeSubmodule S (⊥ : Ideal R) = ⊥ := by |
rw [coeSubmodule, Submodule.map_bot]
|
import Mathlib.Init.Data.Prod
import Mathlib.Data.Seq.WSeq
#align_import data.seq.parallel from "leanprover-community/mathlib"@"a7e36e48519ab281320c4d192da6a7b348ce40ad"
universe u v
namespace Computation
open Stream'
variable {α : Type u} {β : Type v}
def parallel.aux2 : List (Computation α) → Sum α (List (Computation α)) :=
List.foldr
(fun c o =>
match o with
| Sum.inl a => Sum.inl a
| Sum.inr ls => rmap (fun c' => c' :: ls) (destruct c))
(Sum.inr [])
#align computation.parallel.aux2 Computation.parallel.aux2
def parallel.aux1 :
List (Computation α) × WSeq (Computation α) →
Sum α (List (Computation α) × WSeq (Computation α))
| (l, S) =>
rmap
(fun l' =>
match Seq.destruct S with
| none => (l', Seq.nil)
| some (none, S') => (l', S')
| some (some c, S') => (c :: l', S'))
(parallel.aux2 l)
#align computation.parallel.aux1 Computation.parallel.aux1
def parallel (S : WSeq (Computation α)) : Computation α :=
corec parallel.aux1 ([], S)
#align computation.parallel Computation.parallel
theorem terminates_parallel.aux :
∀ {l : List (Computation α)} {S c},
c ∈ l → Terminates c → Terminates (corec parallel.aux1 (l, S)) := by
have lem1 :
∀ l S, (∃ a : α, parallel.aux2 l = Sum.inl a) → Terminates (corec parallel.aux1 (l, S)) := by
intro l S e
cases' e with a e
have : corec parallel.aux1 (l, S) = return a := by
apply destruct_eq_pure
simp only [parallel.aux1, rmap, corec_eq]
rw [e]
rw [this]
-- Porting note: This line is required.
exact ret_terminates a
intro l S c m T
revert l S
apply @terminatesRecOn _ _ c T _ _
· intro a l S m
apply lem1
induction' l with c l IH <;> simp at m
cases' m with e m
· rw [← e]
simp only [parallel.aux2, rmap, List.foldr_cons, destruct_pure]
split <;> simp
· cases' IH m with a' e
simp only [parallel.aux2, rmap, List.foldr_cons]
simp? [parallel.aux2] at e says simp only [parallel.aux2, rmap] at e
rw [e]
exact ⟨a', rfl⟩
· intro s IH l S m
have H1 : ∀ l', parallel.aux2 l = Sum.inr l' → s ∈ l' := by
induction' l with c l IH' <;> intro l' e' <;> simp at m
cases' m with e m <;> simp [parallel.aux2] at e'
· rw [← e] at e'
-- Porting note: `revert e'` & `intro e'` are required.
revert e'
split
· simp
· simp only [destruct_think, Sum.inr.injEq]
rintro rfl
simp
· induction' e : List.foldr (fun c o =>
match o with
| Sum.inl a => Sum.inl a
| Sum.inr ls => rmap (fun c' => c' :: ls) (destruct c))
(Sum.inr List.nil) l with a' ls <;> erw [e] at e'
· contradiction
have := IH' m _ e
-- Porting note: `revert e'` & `intro e'` are required.
revert e'
cases destruct c <;> intro e' <;> [injection e'; injection e' with h']
rw [← h']
simp [this]
induction' h : parallel.aux2 l with a l'
· exact lem1 _ _ ⟨a, h⟩
· have H2 : corec parallel.aux1 (l, S) = think _ := destruct_eq_think (by
simp only [parallel.aux1, rmap, corec_eq]
rw [h])
rw [H2]
refine @Computation.think_terminates _ _ ?_
have := H1 _ h
rcases Seq.destruct S with (_ | ⟨_ | c, S'⟩) <;> simp [parallel.aux1] <;> apply IH <;>
simp [this]
#align computation.terminates_parallel.aux Computation.terminates_parallel.aux
| Mathlib/Data/Seq/Parallel.lean | 122 | 186 | theorem terminates_parallel {S : WSeq (Computation α)} {c} (h : c ∈ S) [T : Terminates c] :
Terminates (parallel S) := by |
suffices
∀ (n) (l : List (Computation α)) (S c),
c ∈ l ∨ some (some c) = Seq.get? S n → Terminates c → Terminates (corec parallel.aux1 (l, S))
from
let ⟨n, h⟩ := h
this n [] S c (Or.inr h) T
intro n; induction' n with n IH <;> intro l S c o T
· cases' o with a a
· exact terminates_parallel.aux a T
have H : Seq.destruct S = some (some c, Seq.tail S) := by simp [Seq.destruct, (· <$> ·), ← a]
induction' h : parallel.aux2 l with a l'
· have C : corec parallel.aux1 (l, S) = pure a := by
apply destruct_eq_pure
rw [corec_eq, parallel.aux1]
dsimp only []
rw [h]
simp only [rmap]
rw [C]
infer_instance
· have C : corec parallel.aux1 (l, S) = _ := destruct_eq_think (by
simp only [corec_eq, rmap, parallel.aux1.eq_1]
rw [h, H])
rw [C]
refine @Computation.think_terminates _ _ ?_
apply terminates_parallel.aux _ T
simp
· cases' o with a a
· exact terminates_parallel.aux a T
induction' h : parallel.aux2 l with a l'
· have C : corec parallel.aux1 (l, S) = pure a := by
apply destruct_eq_pure
rw [corec_eq, parallel.aux1]
dsimp only []
rw [h]
simp only [rmap]
rw [C]
infer_instance
· have C : corec parallel.aux1 (l, S) = _ := destruct_eq_think (by
simp only [corec_eq, rmap, parallel.aux1.eq_1]
rw [h])
rw [C]
refine @Computation.think_terminates _ _ ?_
have TT : ∀ l', Terminates (corec parallel.aux1 (l', S.tail)) := by
intro
apply IH _ _ _ (Or.inr _) T
rw [a]
cases' S with f al
rfl
induction' e : Seq.get? S 0 with o
· have D : Seq.destruct S = none := by
dsimp [Seq.destruct]
rw [e]
rfl
rw [D]
simp only
have TT := TT l'
rwa [Seq.destruct_eq_nil D, Seq.tail_nil] at TT
· have D : Seq.destruct S = some (o, S.tail) := by
dsimp [Seq.destruct]
rw [e]
rfl
rw [D]
cases' o with c <;> simp [parallel.aux1, TT]
|
import Mathlib.Algebra.BigOperators.NatAntidiagonal
import Mathlib.Algebra.GeomSum
import Mathlib.Data.Fintype.BigOperators
import Mathlib.RingTheory.PowerSeries.Inverse
import Mathlib.RingTheory.PowerSeries.WellKnown
import Mathlib.Tactic.FieldSimp
#align_import number_theory.bernoulli from "leanprover-community/mathlib"@"2196ab363eb097c008d4497125e0dde23fb36db2"
open Nat Finset Finset.Nat PowerSeries
variable (A : Type*) [CommRing A] [Algebra ℚ A]
def bernoulli' : ℕ → ℚ :=
WellFounded.fix Nat.lt_wfRel.wf fun n bernoulli' =>
1 - ∑ k : Fin n, n.choose k / (n - k + 1) * bernoulli' k k.2
#align bernoulli' bernoulli'
theorem bernoulli'_def' (n : ℕ) :
bernoulli' n = 1 - ∑ k : Fin n, n.choose k / (n - k + 1) * bernoulli' k :=
WellFounded.fix_eq _ _ _
#align bernoulli'_def' bernoulli'_def'
theorem bernoulli'_def (n : ℕ) :
bernoulli' n = 1 - ∑ k ∈ range n, n.choose k / (n - k + 1) * bernoulli' k := by
rw [bernoulli'_def', ← Fin.sum_univ_eq_sum_range]
#align bernoulli'_def bernoulli'_def
theorem bernoulli'_spec (n : ℕ) :
(∑ k ∈ range n.succ, (n.choose (n - k) : ℚ) / (n - k + 1) * bernoulli' k) = 1 := by
rw [sum_range_succ_comm, bernoulli'_def n, tsub_self, choose_zero_right, sub_self, zero_add,
div_one, cast_one, one_mul, sub_add, ← sum_sub_distrib, ← sub_eq_zero, sub_sub_cancel_left,
neg_eq_zero]
exact Finset.sum_eq_zero (fun x hx => by rw [choose_symm (le_of_lt (mem_range.1 hx)), sub_self])
#align bernoulli'_spec bernoulli'_spec
theorem bernoulli'_spec' (n : ℕ) :
(∑ k ∈ antidiagonal n, ((k.1 + k.2).choose k.2 : ℚ) / (k.2 + 1) * bernoulli' k.1) = 1 := by
refine ((sum_antidiagonal_eq_sum_range_succ_mk _ n).trans ?_).trans (bernoulli'_spec n)
refine sum_congr rfl fun x hx => ?_
simp only [add_tsub_cancel_of_le, mem_range_succ_iff.mp hx, cast_sub]
#align bernoulli'_spec' bernoulli'_spec'
section Examples
@[simp]
| Mathlib/NumberTheory/Bernoulli.lean | 104 | 106 | theorem bernoulli'_zero : bernoulli' 0 = 1 := by |
rw [bernoulli'_def]
norm_num
|
import Mathlib.Algebra.Group.Hom.Defs
import Mathlib.Data.Set.Lattice
import Mathlib.Data.SetLike.Basic
#align_import group_theory.subsemigroup.basic from "leanprover-community/mathlib"@"feb99064803fd3108e37c18b0f77d0a8344677a3"
assert_not_exists MonoidWithZero
-- Only needed for notation
variable {M : Type*} {N : Type*} {A : Type*}
section NonAssoc
variable [Mul M] {s : Set M}
variable [Add A] {t : Set A}
class MulMemClass (S : Type*) (M : Type*) [Mul M] [SetLike S M] : Prop where
mul_mem : ∀ {s : S} {a b : M}, a ∈ s → b ∈ s → a * b ∈ s
#align mul_mem_class MulMemClass
export MulMemClass (mul_mem)
class AddMemClass (S : Type*) (M : Type*) [Add M] [SetLike S M] : Prop where
add_mem : ∀ {s : S} {a b : M}, a ∈ s → b ∈ s → a + b ∈ s
#align add_mem_class AddMemClass
export AddMemClass (add_mem)
attribute [to_additive] MulMemClass
attribute [aesop safe apply (rule_sets := [SetLike])] mul_mem add_mem
structure Subsemigroup (M : Type*) [Mul M] where
carrier : Set M
mul_mem' {a b} : a ∈ carrier → b ∈ carrier → a * b ∈ carrier
#align subsemigroup Subsemigroup
structure AddSubsemigroup (M : Type*) [Add M] where
carrier : Set M
add_mem' {a b} : a ∈ carrier → b ∈ carrier → a + b ∈ carrier
#align add_subsemigroup AddSubsemigroup
attribute [to_additive AddSubsemigroup] Subsemigroup
namespace Subsemigroup
@[to_additive]
instance : SetLike (Subsemigroup M) M :=
⟨Subsemigroup.carrier, fun p q h => by cases p; cases q; congr⟩
@[to_additive]
instance : MulMemClass (Subsemigroup M) M where mul_mem := fun {_ _ _} => Subsemigroup.mul_mem' _
initialize_simps_projections Subsemigroup (carrier → coe)
initialize_simps_projections AddSubsemigroup (carrier → coe)
@[to_additive (attr := simp)]
theorem mem_carrier {s : Subsemigroup M} {x : M} : x ∈ s.carrier ↔ x ∈ s :=
Iff.rfl
#align subsemigroup.mem_carrier Subsemigroup.mem_carrier
#align add_subsemigroup.mem_carrier AddSubsemigroup.mem_carrier
@[to_additive (attr := simp)]
theorem mem_mk {s : Set M} {x : M} (h_mul) : x ∈ mk s h_mul ↔ x ∈ s :=
Iff.rfl
#align subsemigroup.mem_mk Subsemigroup.mem_mk
#align add_subsemigroup.mem_mk AddSubsemigroup.mem_mk
@[to_additive (attr := simp, norm_cast)]
theorem coe_set_mk {s : Set M} (h_mul) : (mk s h_mul : Set M) = s :=
rfl
#align subsemigroup.coe_set_mk Subsemigroup.coe_set_mk
#align add_subsemigroup.coe_set_mk AddSubsemigroup.coe_set_mk
@[to_additive (attr := simp)]
theorem mk_le_mk {s t : Set M} (h_mul) (h_mul') : mk s h_mul ≤ mk t h_mul' ↔ s ⊆ t :=
Iff.rfl
#align subsemigroup.mk_le_mk Subsemigroup.mk_le_mk
#align add_subsemigroup.mk_le_mk AddSubsemigroup.mk_le_mk
@[to_additive (attr := ext) "Two `AddSubsemigroup`s are equal if they have the same elements."]
theorem ext {S T : Subsemigroup M} (h : ∀ x, x ∈ S ↔ x ∈ T) : S = T :=
SetLike.ext h
#align subsemigroup.ext Subsemigroup.ext
#align add_subsemigroup.ext AddSubsemigroup.ext
@[to_additive "Copy an additive subsemigroup replacing `carrier` with a set that is equal to it."]
protected def copy (S : Subsemigroup M) (s : Set M) (hs : s = S) :
Subsemigroup M where
carrier := s
mul_mem' := hs.symm ▸ S.mul_mem'
#align subsemigroup.copy Subsemigroup.copy
#align add_subsemigroup.copy AddSubsemigroup.copy
variable {S : Subsemigroup M}
@[to_additive (attr := simp)]
theorem coe_copy {s : Set M} (hs : s = S) : (S.copy s hs : Set M) = s :=
rfl
#align subsemigroup.coe_copy Subsemigroup.coe_copy
#align add_subsemigroup.coe_copy AddSubsemigroup.coe_copy
@[to_additive]
theorem copy_eq {s : Set M} (hs : s = S) : S.copy s hs = S :=
SetLike.coe_injective hs
#align subsemigroup.copy_eq Subsemigroup.copy_eq
#align add_subsemigroup.copy_eq AddSubsemigroup.copy_eq
variable (S)
@[to_additive "An `AddSubsemigroup` is closed under addition."]
protected theorem mul_mem {x y : M} : x ∈ S → y ∈ S → x * y ∈ S :=
Subsemigroup.mul_mem' S
#align subsemigroup.mul_mem Subsemigroup.mul_mem
#align add_subsemigroup.add_mem AddSubsemigroup.add_mem
@[to_additive "The additive subsemigroup `M` of the magma `M`."]
instance : Top (Subsemigroup M) :=
⟨{ carrier := Set.univ
mul_mem' := fun _ _ => Set.mem_univ _ }⟩
@[to_additive "The trivial `AddSubsemigroup` `∅` of an additive magma `M`."]
instance : Bot (Subsemigroup M) :=
⟨{ carrier := ∅
mul_mem' := False.elim }⟩
@[to_additive]
instance : Inhabited (Subsemigroup M) :=
⟨⊥⟩
@[to_additive]
theorem not_mem_bot {x : M} : x ∉ (⊥ : Subsemigroup M) :=
Set.not_mem_empty x
#align subsemigroup.not_mem_bot Subsemigroup.not_mem_bot
#align add_subsemigroup.not_mem_bot AddSubsemigroup.not_mem_bot
@[to_additive (attr := simp)]
theorem mem_top (x : M) : x ∈ (⊤ : Subsemigroup M) :=
Set.mem_univ x
#align subsemigroup.mem_top Subsemigroup.mem_top
#align add_subsemigroup.mem_top AddSubsemigroup.mem_top
@[to_additive (attr := simp)]
theorem coe_top : ((⊤ : Subsemigroup M) : Set M) = Set.univ :=
rfl
#align subsemigroup.coe_top Subsemigroup.coe_top
#align add_subsemigroup.coe_top AddSubsemigroup.coe_top
@[to_additive (attr := simp)]
theorem coe_bot : ((⊥ : Subsemigroup M) : Set M) = ∅ :=
rfl
#align subsemigroup.coe_bot Subsemigroup.coe_bot
#align add_subsemigroup.coe_bot AddSubsemigroup.coe_bot
@[to_additive "The inf of two `AddSubsemigroup`s is their intersection."]
instance : Inf (Subsemigroup M) :=
⟨fun S₁ S₂ =>
{ carrier := S₁ ∩ S₂
mul_mem' := fun ⟨hx, hx'⟩ ⟨hy, hy'⟩ => ⟨S₁.mul_mem hx hy, S₂.mul_mem hx' hy'⟩ }⟩
@[to_additive (attr := simp)]
theorem coe_inf (p p' : Subsemigroup M) : ((p ⊓ p' : Subsemigroup M) : Set M) = (p : Set M) ∩ p' :=
rfl
#align subsemigroup.coe_inf Subsemigroup.coe_inf
#align add_subsemigroup.coe_inf AddSubsemigroup.coe_inf
@[to_additive (attr := simp)]
theorem mem_inf {p p' : Subsemigroup M} {x : M} : x ∈ p ⊓ p' ↔ x ∈ p ∧ x ∈ p' :=
Iff.rfl
#align subsemigroup.mem_inf Subsemigroup.mem_inf
#align add_subsemigroup.mem_inf AddSubsemigroup.mem_inf
@[to_additive]
instance : InfSet (Subsemigroup M) :=
⟨fun s =>
{ carrier := ⋂ t ∈ s, ↑t
mul_mem' := fun hx hy =>
Set.mem_biInter fun i h =>
i.mul_mem (by apply Set.mem_iInter₂.1 hx i h) (by apply Set.mem_iInter₂.1 hy i h) }⟩
@[to_additive (attr := simp, norm_cast)]
theorem coe_sInf (S : Set (Subsemigroup M)) : ((sInf S : Subsemigroup M) : Set M) = ⋂ s ∈ S, ↑s :=
rfl
#align subsemigroup.coe_Inf Subsemigroup.coe_sInf
#align add_subsemigroup.coe_Inf AddSubsemigroup.coe_sInf
@[to_additive]
theorem mem_sInf {S : Set (Subsemigroup M)} {x : M} : x ∈ sInf S ↔ ∀ p ∈ S, x ∈ p :=
Set.mem_iInter₂
#align subsemigroup.mem_Inf Subsemigroup.mem_sInf
#align add_subsemigroup.mem_Inf AddSubsemigroup.mem_sInf
@[to_additive]
theorem mem_iInf {ι : Sort*} {S : ι → Subsemigroup M} {x : M} : (x ∈ ⨅ i, S i) ↔ ∀ i, x ∈ S i := by
simp only [iInf, mem_sInf, Set.forall_mem_range]
#align subsemigroup.mem_infi Subsemigroup.mem_iInf
#align add_subsemigroup.mem_infi AddSubsemigroup.mem_iInf
@[to_additive (attr := simp, norm_cast)]
theorem coe_iInf {ι : Sort*} {S : ι → Subsemigroup M} : (↑(⨅ i, S i) : Set M) = ⋂ i, S i := by
simp only [iInf, coe_sInf, Set.biInter_range]
#align subsemigroup.coe_infi Subsemigroup.coe_iInf
#align add_subsemigroup.coe_infi AddSubsemigroup.coe_iInf
@[to_additive "The `AddSubsemigroup`s of an `AddMonoid` form a complete lattice."]
instance : CompleteLattice (Subsemigroup M) :=
{ completeLatticeOfInf (Subsemigroup M) fun _ =>
IsGLB.of_image SetLike.coe_subset_coe isGLB_biInf with
le := (· ≤ ·)
lt := (· < ·)
bot := ⊥
bot_le := fun _ _ hx => (not_mem_bot hx).elim
top := ⊤
le_top := fun _ x _ => mem_top x
inf := (· ⊓ ·)
sInf := InfSet.sInf
le_inf := fun _ _ _ ha hb _ hx => ⟨ha hx, hb hx⟩
inf_le_left := fun _ _ _ => And.left
inf_le_right := fun _ _ _ => And.right }
@[to_additive]
theorem subsingleton_of_subsingleton [Subsingleton (Subsemigroup M)] : Subsingleton M := by
constructor; intro x y
have : ∀ a : M, a ∈ (⊥ : Subsemigroup M) := by simp [Subsingleton.elim (⊥ : Subsemigroup M) ⊤]
exact absurd (this x) not_mem_bot
#align subsemigroup.subsingleton_of_subsingleton Subsemigroup.subsingleton_of_subsingleton
#align add_subsemigroup.subsingleton_of_subsingleton AddSubsemigroup.subsingleton_of_subsingleton
@[to_additive]
instance [hn : Nonempty M] : Nontrivial (Subsemigroup M) :=
⟨⟨⊥, ⊤, fun h => by
obtain ⟨x⟩ := id hn
refine absurd (?_ : x ∈ ⊥) not_mem_bot
simp [h]⟩⟩
@[to_additive "The `AddSubsemigroup` generated by a set"]
def closure (s : Set M) : Subsemigroup M :=
sInf { S | s ⊆ S }
#align subsemigroup.closure Subsemigroup.closure
#align add_subsemigroup.closure AddSubsemigroup.closure
@[to_additive]
theorem mem_closure {x : M} : x ∈ closure s ↔ ∀ S : Subsemigroup M, s ⊆ S → x ∈ S :=
mem_sInf
#align subsemigroup.mem_closure Subsemigroup.mem_closure
#align add_subsemigroup.mem_closure AddSubsemigroup.mem_closure
@[to_additive (attr := simp, aesop safe 20 apply (rule_sets := [SetLike]))
"The `AddSubsemigroup` generated by a set includes the set."]
theorem subset_closure : s ⊆ closure s := fun _ hx => mem_closure.2 fun _ hS => hS hx
#align subsemigroup.subset_closure Subsemigroup.subset_closure
#align add_subsemigroup.subset_closure AddSubsemigroup.subset_closure
@[to_additive]
theorem not_mem_of_not_mem_closure {P : M} (hP : P ∉ closure s) : P ∉ s := fun h =>
hP (subset_closure h)
#align subsemigroup.not_mem_of_not_mem_closure Subsemigroup.not_mem_of_not_mem_closure
#align add_subsemigroup.not_mem_of_not_mem_closure AddSubsemigroup.not_mem_of_not_mem_closure
variable {S}
open Set
@[to_additive (attr := simp)
"An additive subsemigroup `S` includes `closure s` if and only if it includes `s`"]
theorem closure_le : closure s ≤ S ↔ s ⊆ S :=
⟨Subset.trans subset_closure, fun h => sInf_le h⟩
#align subsemigroup.closure_le Subsemigroup.closure_le
#align add_subsemigroup.closure_le AddSubsemigroup.closure_le
@[to_additive "Additive subsemigroup closure of a set is monotone in its argument: if `s ⊆ t`,
then `closure s ≤ closure t`"]
theorem closure_mono ⦃s t : Set M⦄ (h : s ⊆ t) : closure s ≤ closure t :=
closure_le.2 <| Subset.trans h subset_closure
#align subsemigroup.closure_mono Subsemigroup.closure_mono
#align add_subsemigroup.closure_mono AddSubsemigroup.closure_mono
@[to_additive]
theorem closure_eq_of_le (h₁ : s ⊆ S) (h₂ : S ≤ closure s) : closure s = S :=
le_antisymm (closure_le.2 h₁) h₂
#align subsemigroup.closure_eq_of_le Subsemigroup.closure_eq_of_le
#align add_subsemigroup.closure_eq_of_le AddSubsemigroup.closure_eq_of_le
variable (S)
@[to_additive (attr := elab_as_elim) "An induction principle for additive closure membership. If `p`
holds for all elements of `s`, and is preserved under addition, then `p` holds for all
elements of the additive closure of `s`."]
theorem closure_induction {p : M → Prop} {x} (h : x ∈ closure s) (mem : ∀ x ∈ s, p x)
(mul : ∀ x y, p x → p y → p (x * y)) : p x :=
(@closure_le _ _ _ ⟨p, mul _ _⟩).2 mem h
#align subsemigroup.closure_induction Subsemigroup.closure_induction
#align add_subsemigroup.closure_induction AddSubsemigroup.closure_induction
@[to_additive (attr := elab_as_elim) "A dependent version of `AddSubsemigroup.closure_induction`. "]
theorem closure_induction' (s : Set M) {p : ∀ x, x ∈ closure s → Prop}
(mem : ∀ (x) (h : x ∈ s), p x (subset_closure h))
(mul : ∀ x hx y hy, p x hx → p y hy → p (x * y) (mul_mem hx hy)) {x} (hx : x ∈ closure s) :
p x hx := by
refine Exists.elim ?_ fun (hx : x ∈ closure s) (hc : p x hx) => hc
exact
closure_induction hx (fun x hx => ⟨_, mem x hx⟩) fun x y ⟨hx', hx⟩ ⟨hy', hy⟩ =>
⟨_, mul _ _ _ _ hx hy⟩
#align subsemigroup.closure_induction' Subsemigroup.closure_induction'
#align add_subsemigroup.closure_induction' AddSubsemigroup.closure_induction'
@[to_additive (attr := elab_as_elim) "An induction principle for additive closure membership for
predicates with two arguments."]
theorem closure_induction₂ {p : M → M → Prop} {x} {y : M} (hx : x ∈ closure s) (hy : y ∈ closure s)
(Hs : ∀ x ∈ s, ∀ y ∈ s, p x y) (Hmul_left : ∀ x y z, p x z → p y z → p (x * y) z)
(Hmul_right : ∀ x y z, p z x → p z y → p z (x * y)) : p x y :=
closure_induction hx
(fun x xs => closure_induction hy (Hs x xs) fun z _ h₁ h₂ => Hmul_right z _ _ h₁ h₂)
fun _ _ h₁ h₂ => Hmul_left _ _ _ h₁ h₂
#align subsemigroup.closure_induction₂ Subsemigroup.closure_induction₂
#align add_subsemigroup.closure_induction₂ AddSubsemigroup.closure_induction₂
@[to_additive (attr := elab_as_elim) "If `s` is a dense set in an additive monoid `M`,
`AddSubsemigroup.closure s = ⊤`, then in order to prove that some predicate `p` holds
for all `x : M` it suffices to verify `p x` for `x ∈ s`, and verify that `p x` and `p y` imply
`p (x + y)`."]
| Mathlib/Algebra/Group/Subsemigroup/Basic.lean | 395 | 399 | theorem dense_induction {p : M → Prop} (x : M) {s : Set M} (hs : closure s = ⊤)
(mem : ∀ x ∈ s, p x)
(mul : ∀ x y, p x → p y → p (x * y)) : p x := by |
have : ∀ x ∈ closure s, p x := fun x hx => closure_induction hx mem mul
simpa [hs] using this x
|
import Mathlib.Order.Interval.Set.Monotone
import Mathlib.Probability.Process.HittingTime
import Mathlib.Probability.Martingale.Basic
import Mathlib.Tactic.AdaptationNote
#align_import probability.martingale.upcrossing from "leanprover-community/mathlib"@"2c1d8ca2812b64f88992a5294ea3dba144755cd1"
open TopologicalSpace Filter
open scoped NNReal ENNReal MeasureTheory ProbabilityTheory Topology
namespace MeasureTheory
variable {Ω ι : Type*} {m0 : MeasurableSpace Ω} {μ : Measure Ω}
noncomputable def lowerCrossingTimeAux [Preorder ι] [InfSet ι] (a : ℝ) (f : ι → Ω → ℝ) (c N : ι) :
Ω → ι :=
hitting f (Set.Iic a) c N
#align measure_theory.lower_crossing_time_aux MeasureTheory.lowerCrossingTimeAux
noncomputable def upperCrossingTime [Preorder ι] [OrderBot ι] [InfSet ι] (a b : ℝ) (f : ι → Ω → ℝ)
(N : ι) : ℕ → Ω → ι
| 0 => ⊥
| n + 1 => fun ω =>
hitting f (Set.Ici b) (lowerCrossingTimeAux a f (upperCrossingTime a b f N n ω) N ω) N ω
#align measure_theory.upper_crossing_time MeasureTheory.upperCrossingTime
noncomputable def lowerCrossingTime [Preorder ι] [OrderBot ι] [InfSet ι] (a b : ℝ) (f : ι → Ω → ℝ)
(N : ι) (n : ℕ) : Ω → ι := fun ω => hitting f (Set.Iic a) (upperCrossingTime a b f N n ω) N ω
#align measure_theory.lower_crossing_time MeasureTheory.lowerCrossingTime
section
variable [Preorder ι] [OrderBot ι] [InfSet ι]
variable {a b : ℝ} {f : ι → Ω → ℝ} {N : ι} {n m : ℕ} {ω : Ω}
@[simp]
theorem upperCrossingTime_zero : upperCrossingTime a b f N 0 = ⊥ :=
rfl
#align measure_theory.upper_crossing_time_zero MeasureTheory.upperCrossingTime_zero
@[simp]
theorem lowerCrossingTime_zero : lowerCrossingTime a b f N 0 = hitting f (Set.Iic a) ⊥ N :=
rfl
#align measure_theory.lower_crossing_time_zero MeasureTheory.lowerCrossingTime_zero
theorem upperCrossingTime_succ : upperCrossingTime a b f N (n + 1) ω =
hitting f (Set.Ici b) (lowerCrossingTimeAux a f (upperCrossingTime a b f N n ω) N ω) N ω := by
rw [upperCrossingTime]
#align measure_theory.upper_crossing_time_succ MeasureTheory.upperCrossingTime_succ
theorem upperCrossingTime_succ_eq (ω : Ω) : upperCrossingTime a b f N (n + 1) ω =
hitting f (Set.Ici b) (lowerCrossingTime a b f N n ω) N ω := by
simp only [upperCrossingTime_succ]
rfl
#align measure_theory.upper_crossing_time_succ_eq MeasureTheory.upperCrossingTime_succ_eq
end
section ConditionallyCompleteLinearOrderBot
variable [ConditionallyCompleteLinearOrderBot ι]
variable {a b : ℝ} {f : ι → Ω → ℝ} {N : ι} {n m : ℕ} {ω : Ω}
theorem upperCrossingTime_le : upperCrossingTime a b f N n ω ≤ N := by
cases n
· simp only [upperCrossingTime_zero, Pi.bot_apply, bot_le, Nat.zero_eq]
· simp only [upperCrossingTime_succ, hitting_le]
#align measure_theory.upper_crossing_time_le MeasureTheory.upperCrossingTime_le
@[simp]
theorem upperCrossingTime_zero' : upperCrossingTime a b f ⊥ n ω = ⊥ :=
eq_bot_iff.2 upperCrossingTime_le
#align measure_theory.upper_crossing_time_zero' MeasureTheory.upperCrossingTime_zero'
theorem lowerCrossingTime_le : lowerCrossingTime a b f N n ω ≤ N := by
simp only [lowerCrossingTime, hitting_le ω]
#align measure_theory.lower_crossing_time_le MeasureTheory.lowerCrossingTime_le
| Mathlib/Probability/Martingale/Upcrossing.lean | 201 | 203 | theorem upperCrossingTime_le_lowerCrossingTime :
upperCrossingTime a b f N n ω ≤ lowerCrossingTime a b f N n ω := by |
simp only [lowerCrossingTime, le_hitting upperCrossingTime_le ω]
|
import Mathlib.Algebra.DirectSum.Internal
import Mathlib.Algebra.GradedMonoid
import Mathlib.Algebra.MvPolynomial.CommRing
import Mathlib.Algebra.MvPolynomial.Equiv
import Mathlib.Algebra.MvPolynomial.Variables
import Mathlib.RingTheory.MvPolynomial.WeightedHomogeneous
import Mathlib.Algebra.Polynomial.Roots
#align_import ring_theory.mv_polynomial.homogeneous from "leanprover-community/mathlib"@"2f5b500a507264de86d666a5f87ddb976e2d8de4"
namespace MvPolynomial
variable {σ : Type*} {τ : Type*} {R : Type*} {S : Type*}
def degree (d : σ →₀ ℕ) := ∑ i ∈ d.support, d i
theorem weightedDegree_one (d : σ →₀ ℕ) :
weightedDegree 1 d = degree d := by
simp [weightedDegree, degree, Finsupp.total, Finsupp.sum]
def IsHomogeneous [CommSemiring R] (φ : MvPolynomial σ R) (n : ℕ) :=
IsWeightedHomogeneous 1 φ n
#align mv_polynomial.is_homogeneous MvPolynomial.IsHomogeneous
variable [CommSemiring R]
theorem weightedTotalDegree_one (φ : MvPolynomial σ R) :
weightedTotalDegree (1 : σ → ℕ) φ = φ.totalDegree := by
simp only [totalDegree, weightedTotalDegree, weightedDegree, LinearMap.toAddMonoidHom_coe,
Finsupp.total, Pi.one_apply, Finsupp.coe_lsum, LinearMap.coe_smulRight, LinearMap.id_coe,
id, Algebra.id.smul_eq_mul, mul_one]
variable (σ R)
def homogeneousSubmodule (n : ℕ) : Submodule R (MvPolynomial σ R) where
carrier := { x | x.IsHomogeneous n }
smul_mem' r a ha c hc := by
rw [coeff_smul] at hc
apply ha
intro h
apply hc
rw [h]
exact smul_zero r
zero_mem' d hd := False.elim (hd <| coeff_zero _)
add_mem' {a b} ha hb c hc := by
rw [coeff_add] at hc
obtain h | h : coeff c a ≠ 0 ∨ coeff c b ≠ 0 := by
contrapose! hc
simp only [hc, add_zero]
· exact ha h
· exact hb h
#align mv_polynomial.homogeneous_submodule MvPolynomial.homogeneousSubmodule
@[simp]
lemma weightedHomogeneousSubmodule_one (n : ℕ) :
weightedHomogeneousSubmodule R 1 n = homogeneousSubmodule σ R n := rfl
variable {σ R}
@[simp]
theorem mem_homogeneousSubmodule [CommSemiring R] (n : ℕ) (p : MvPolynomial σ R) :
p ∈ homogeneousSubmodule σ R n ↔ p.IsHomogeneous n := Iff.rfl
#align mv_polynomial.mem_homogeneous_submodule MvPolynomial.mem_homogeneousSubmodule
variable (σ R)
theorem homogeneousSubmodule_eq_finsupp_supported [CommSemiring R] (n : ℕ) :
homogeneousSubmodule σ R n = Finsupp.supported _ R { d | degree d = n } := by
simp_rw [← weightedDegree_one]
exact weightedHomogeneousSubmodule_eq_finsupp_supported R 1 n
#align mv_polynomial.homogeneous_submodule_eq_finsupp_supported MvPolynomial.homogeneousSubmodule_eq_finsupp_supported
variable {σ R}
theorem homogeneousSubmodule_mul [CommSemiring R] (m n : ℕ) :
homogeneousSubmodule σ R m * homogeneousSubmodule σ R n ≤ homogeneousSubmodule σ R (m + n) :=
weightedHomogeneousSubmodule_mul 1 m n
#align mv_polynomial.homogeneous_submodule_mul MvPolynomial.homogeneousSubmodule_mul
section
variable [CommSemiring R]
theorem isHomogeneous_monomial {d : σ →₀ ℕ} (r : R) {n : ℕ} (hn : degree d = n) :
IsHomogeneous (monomial d r) n := by
simp_rw [← weightedDegree_one] at hn
exact isWeightedHomogeneous_monomial 1 d r hn
#align mv_polynomial.is_homogeneous_monomial MvPolynomial.isHomogeneous_monomial
variable (σ)
theorem totalDegree_zero_iff_isHomogeneous {p : MvPolynomial σ R} :
p.totalDegree = 0 ↔ IsHomogeneous p 0 := by
rw [← weightedTotalDegree_one,
← isWeightedHomogeneous_zero_iff_weightedTotalDegree_eq_zero, IsHomogeneous]
alias ⟨isHomogeneous_of_totalDegree_zero, _⟩ := totalDegree_zero_iff_isHomogeneous
#align mv_polynomial.is_homogeneous_of_total_degree_zero MvPolynomial.isHomogeneous_of_totalDegree_zero
theorem isHomogeneous_C (r : R) : IsHomogeneous (C r : MvPolynomial σ R) 0 := by
apply isHomogeneous_monomial
simp only [degree, Finsupp.zero_apply, Finset.sum_const_zero]
set_option linter.uppercaseLean3 false in
#align mv_polynomial.is_homogeneous_C MvPolynomial.isHomogeneous_C
variable (R)
theorem isHomogeneous_zero (n : ℕ) : IsHomogeneous (0 : MvPolynomial σ R) n :=
(homogeneousSubmodule σ R n).zero_mem
#align mv_polynomial.is_homogeneous_zero MvPolynomial.isHomogeneous_zero
theorem isHomogeneous_one : IsHomogeneous (1 : MvPolynomial σ R) 0 :=
isHomogeneous_C _ _
#align mv_polynomial.is_homogeneous_one MvPolynomial.isHomogeneous_one
variable {σ}
theorem isHomogeneous_X (i : σ) : IsHomogeneous (X i : MvPolynomial σ R) 1 := by
apply isHomogeneous_monomial
rw [degree, Finsupp.support_single_ne_zero _ one_ne_zero, Finset.sum_singleton]
exact Finsupp.single_eq_same
set_option linter.uppercaseLean3 false in
#align mv_polynomial.is_homogeneous_X MvPolynomial.isHomogeneous_X
end
namespace IsHomogeneous
variable [CommSemiring R] [CommSemiring S] {φ ψ : MvPolynomial σ R} {m n : ℕ}
theorem coeff_eq_zero (hφ : IsHomogeneous φ n) {d : σ →₀ ℕ} (hd : degree d ≠ n) :
coeff d φ = 0 := by
simp_rw [← weightedDegree_one] at hd
exact IsWeightedHomogeneous.coeff_eq_zero hφ d hd
#align mv_polynomial.is_homogeneous.coeff_eq_zero MvPolynomial.IsHomogeneous.coeff_eq_zero
theorem inj_right (hm : IsHomogeneous φ m) (hn : IsHomogeneous φ n) (hφ : φ ≠ 0) : m = n := by
obtain ⟨d, hd⟩ : ∃ d, coeff d φ ≠ 0 := exists_coeff_ne_zero hφ
rw [← hm hd, ← hn hd]
#align mv_polynomial.is_homogeneous.inj_right MvPolynomial.IsHomogeneous.inj_right
theorem add (hφ : IsHomogeneous φ n) (hψ : IsHomogeneous ψ n) : IsHomogeneous (φ + ψ) n :=
(homogeneousSubmodule σ R n).add_mem hφ hψ
#align mv_polynomial.is_homogeneous.add MvPolynomial.IsHomogeneous.add
theorem sum {ι : Type*} (s : Finset ι) (φ : ι → MvPolynomial σ R) (n : ℕ)
(h : ∀ i ∈ s, IsHomogeneous (φ i) n) : IsHomogeneous (∑ i ∈ s, φ i) n :=
(homogeneousSubmodule σ R n).sum_mem h
#align mv_polynomial.is_homogeneous.sum MvPolynomial.IsHomogeneous.sum
theorem mul (hφ : IsHomogeneous φ m) (hψ : IsHomogeneous ψ n) : IsHomogeneous (φ * ψ) (m + n) :=
homogeneousSubmodule_mul m n <| Submodule.mul_mem_mul hφ hψ
#align mv_polynomial.is_homogeneous.mul MvPolynomial.IsHomogeneous.mul
theorem prod {ι : Type*} (s : Finset ι) (φ : ι → MvPolynomial σ R) (n : ι → ℕ)
(h : ∀ i ∈ s, IsHomogeneous (φ i) (n i)) : IsHomogeneous (∏ i ∈ s, φ i) (∑ i ∈ s, n i) := by
classical
revert h
refine Finset.induction_on s ?_ ?_
· intro
simp only [isHomogeneous_one, Finset.sum_empty, Finset.prod_empty]
· intro i s his IH h
simp only [his, Finset.prod_insert, Finset.sum_insert, not_false_iff]
apply (h i (Finset.mem_insert_self _ _)).mul (IH _)
intro j hjs
exact h j (Finset.mem_insert_of_mem hjs)
#align mv_polynomial.is_homogeneous.prod MvPolynomial.IsHomogeneous.prod
lemma C_mul (hφ : φ.IsHomogeneous m) (r : R) :
(C r * φ).IsHomogeneous m := by
simpa only [zero_add] using (isHomogeneous_C _ _).mul hφ
lemma _root_.MvPolynomial.isHomogeneous_C_mul_X (r : R) (i : σ) :
(C r * X i).IsHomogeneous 1 :=
(isHomogeneous_X _ _).C_mul _
@[deprecated (since := "2024-03-21")]
alias _root_.MvPolynomial.C_mul_X := _root_.MvPolynomial.isHomogeneous_C_mul_X
lemma pow (hφ : φ.IsHomogeneous m) (n : ℕ) : (φ ^ n).IsHomogeneous (m * n) := by
rw [show φ ^ n = ∏ _i ∈ Finset.range n, φ by simp]
rw [show m * n = ∑ _i ∈ Finset.range n, m by simp [mul_comm]]
apply IsHomogeneous.prod _ _ _ (fun _ _ ↦ hφ)
lemma _root_.MvPolynomial.isHomogeneous_X_pow (i : σ) (n : ℕ) :
(X (R := R) i ^ n).IsHomogeneous n := by
simpa only [one_mul] using (isHomogeneous_X _ _).pow n
lemma _root_.MvPolynomial.isHomogeneous_C_mul_X_pow (r : R) (i : σ) (n : ℕ) :
(C r * X i ^ n).IsHomogeneous n :=
(isHomogeneous_X_pow _ _).C_mul _
lemma eval₂ (hφ : φ.IsHomogeneous m) (f : R →+* MvPolynomial τ S) (g : σ → MvPolynomial τ S)
(hf : ∀ r, (f r).IsHomogeneous 0) (hg : ∀ i, (g i).IsHomogeneous n) :
(eval₂ f g φ).IsHomogeneous (n * m) := by
apply IsHomogeneous.sum
intro i hi
rw [← zero_add (n * m)]
apply IsHomogeneous.mul (hf _) _
convert IsHomogeneous.prod _ _ (fun k ↦ n * i k) _
· rw [Finsupp.mem_support_iff] at hi
rw [← Finset.mul_sum, ← hφ hi, weightedDegree_apply]
simp_rw [smul_eq_mul, Finsupp.sum, Pi.one_apply, mul_one]
· rintro k -
apply (hg k).pow
lemma map (hφ : φ.IsHomogeneous n) (f : R →+* S) : (map f φ).IsHomogeneous n := by
simpa only [one_mul] using hφ.eval₂ _ _ (fun r ↦ isHomogeneous_C _ (f r)) (isHomogeneous_X _)
lemma aeval [Algebra R S] (hφ : φ.IsHomogeneous m)
(g : σ → MvPolynomial τ S) (hg : ∀ i, (g i).IsHomogeneous n) :
(aeval g φ).IsHomogeneous (n * m) :=
hφ.eval₂ _ _ (fun _ ↦ isHomogeneous_C _ _) hg
lemma totalDegree_le (hφ : IsHomogeneous φ n) : φ.totalDegree ≤ n := by
apply Finset.sup_le
intro d hd
rw [mem_support_iff] at hd
rw [Finsupp.sum, ← hφ hd, weightedDegree_apply]
simp only [Pi.one_apply, smul_eq_mul, mul_one]
exact Nat.le.refl
| Mathlib/RingTheory/MvPolynomial/Homogeneous.lean | 271 | 278 | theorem totalDegree (hφ : IsHomogeneous φ n) (h : φ ≠ 0) : totalDegree φ = n := by |
apply le_antisymm hφ.totalDegree_le
obtain ⟨d, hd⟩ : ∃ d, coeff d φ ≠ 0 := exists_coeff_ne_zero h
simp only [← hφ hd, MvPolynomial.totalDegree, Finsupp.sum]
replace hd := Finsupp.mem_support_iff.mpr hd
simp only [weightedDegree_apply,Pi.one_apply, smul_eq_mul, mul_one, ge_iff_le]
-- Porting note: Original proof did not define `f`
exact Finset.le_sup (f := fun s ↦ ∑ x ∈ s.support, s x) hd
|
import Mathlib.MeasureTheory.MeasurableSpace.Basic
import Mathlib.MeasureTheory.Measure.MeasureSpaceDef
#align_import measure_theory.function.ae_measurable_sequence from "leanprover-community/mathlib"@"d003c55042c3cd08aefd1ae9a42ef89441cdaaf3"
open MeasureTheory
open scoped Classical
variable {ι : Sort*} {α β γ : Type*} [MeasurableSpace α] [MeasurableSpace β] {f : ι → α → β}
{μ : Measure α} {p : α → (ι → β) → Prop}
def aeSeqSet (hf : ∀ i, AEMeasurable (f i) μ) (p : α → (ι → β) → Prop) : Set α :=
(toMeasurable μ { x | (∀ i, f i x = (hf i).mk (f i) x) ∧ p x fun n => f n x }ᶜ)ᶜ
#align ae_seq_set aeSeqSet
noncomputable def aeSeq (hf : ∀ i, AEMeasurable (f i) μ) (p : α → (ι → β) → Prop) : ι → α → β :=
fun i x => ite (x ∈ aeSeqSet hf p) ((hf i).mk (f i) x) (⟨f i x⟩ : Nonempty β).some
#align ae_seq aeSeq
namespace aeSeq
section MemAESeqSet
theorem mk_eq_fun_of_mem_aeSeqSet (hf : ∀ i, AEMeasurable (f i) μ) {x : α} (hx : x ∈ aeSeqSet hf p)
(i : ι) : (hf i).mk (f i) x = f i x :=
haveI h_ss : aeSeqSet hf p ⊆ { x | ∀ i, f i x = (hf i).mk (f i) x } := by
rw [aeSeqSet, ← compl_compl { x | ∀ i, f i x = (hf i).mk (f i) x }, Set.compl_subset_compl]
refine Set.Subset.trans (Set.compl_subset_compl.mpr fun x h => ?_) (subset_toMeasurable _ _)
exact h.1
(h_ss hx i).symm
#align ae_seq.mk_eq_fun_of_mem_ae_seq_set aeSeq.mk_eq_fun_of_mem_aeSeqSet
theorem aeSeq_eq_mk_of_mem_aeSeqSet (hf : ∀ i, AEMeasurable (f i) μ) {x : α}
(hx : x ∈ aeSeqSet hf p) (i : ι) : aeSeq hf p i x = (hf i).mk (f i) x := by
simp only [aeSeq, hx, if_true]
#align ae_seq.ae_seq_eq_mk_of_mem_ae_seq_set aeSeq.aeSeq_eq_mk_of_mem_aeSeqSet
theorem aeSeq_eq_fun_of_mem_aeSeqSet (hf : ∀ i, AEMeasurable (f i) μ) {x : α}
(hx : x ∈ aeSeqSet hf p) (i : ι) : aeSeq hf p i x = f i x := by
simp only [aeSeq_eq_mk_of_mem_aeSeqSet hf hx i, mk_eq_fun_of_mem_aeSeqSet hf hx i]
#align ae_seq.ae_seq_eq_fun_of_mem_ae_seq_set aeSeq.aeSeq_eq_fun_of_mem_aeSeqSet
theorem prop_of_mem_aeSeqSet (hf : ∀ i, AEMeasurable (f i) μ) {x : α} (hx : x ∈ aeSeqSet hf p) :
p x fun n => aeSeq hf p n x := by
simp only [aeSeq, hx, if_true]
rw [funext fun n => mk_eq_fun_of_mem_aeSeqSet hf hx n]
have h_ss : aeSeqSet hf p ⊆ { x | p x fun n => f n x } := by
rw [← compl_compl { x | p x fun n => f n x }, aeSeqSet, Set.compl_subset_compl]
refine Set.Subset.trans (Set.compl_subset_compl.mpr ?_) (subset_toMeasurable _ _)
exact fun x hx => hx.2
have hx' := Set.mem_of_subset_of_mem h_ss hx
exact hx'
#align ae_seq.prop_of_mem_ae_seq_set aeSeq.prop_of_mem_aeSeqSet
| Mathlib/MeasureTheory/Function/AEMeasurableSequence.lean | 81 | 86 | theorem fun_prop_of_mem_aeSeqSet (hf : ∀ i, AEMeasurable (f i) μ) {x : α} (hx : x ∈ aeSeqSet hf p) :
p x fun n => f n x := by |
have h_eq : (fun n => f n x) = fun n => aeSeq hf p n x :=
funext fun n => (aeSeq_eq_fun_of_mem_aeSeqSet hf hx n).symm
rw [h_eq]
exact prop_of_mem_aeSeqSet hf hx
|
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