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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
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
set_option linter.uppercaseLean3 false in
#align le_dimH_of_hausdorff_measure_eq_top le_dimH_of_hausdorffMeasure_eq_top
| Mathlib/Topology/MetricSpace/HausdorffDimension.lean | 139 | 144 | theorem hausdorffMeasure_of_dimH_lt {s : Set X} {d : ℝ≥0} (h : dimH s < d) : μH[d] s = 0 := by |
rw [dimH_def] at h
rcases ENNReal.lt_iff_exists_nnreal_btwn.1 h with ⟨d', hsd', hd'd⟩
rw [ENNReal.coe_lt_coe, ← NNReal.coe_lt_coe] at hd'd
exact (hausdorffMeasure_zero_or_top hd'd s).resolve_right fun h₂ => hsd'.not_le <|
le_iSup₂ (α := ℝ≥0∞) d' h₂
|
import Mathlib.Algebra.Polynomial.DenomsClearable
import Mathlib.Analysis.Calculus.MeanValue
import Mathlib.Analysis.Calculus.Deriv.Polynomial
import Mathlib.Data.Real.Irrational
import Mathlib.Topology.Algebra.Polynomial
#align_import number_theory.liouville.basic from "leanprover-community/mathlib"@"04e80bb7e8510958cd9aacd32fe2dc147af0b9f1"
def Liouville (x : ℝ) :=
∀ n : ℕ, ∃ a b : ℤ, 1 < b ∧ x ≠ a / b ∧ |x - a / b| < 1 / (b : ℝ) ^ n
#align liouville Liouville
namespace Liouville
protected theorem irrational {x : ℝ} (h : Liouville x) : Irrational x := by
-- By contradiction, `x = a / b`, with `a ∈ ℤ`, `0 < b ∈ ℕ` is a Liouville number,
rintro ⟨⟨a, b, bN0, cop⟩, rfl⟩
-- clear up the mess of constructions of rationals
rw [Rat.cast_mk'] at h
-- Since `a / b` is a Liouville number, there are `p, q ∈ ℤ`, with `q1 : 1 < q`,∈
-- `a0 : a / b ≠ p / q` and `a1 : |a / b - p / q| < 1 / q ^ (b + 1)`
rcases h (b + 1) with ⟨p, q, q1, a0, a1⟩
-- A few useful inequalities
have qR0 : (0 : ℝ) < q := Int.cast_pos.mpr (zero_lt_one.trans q1)
have b0 : (b : ℝ) ≠ 0 := Nat.cast_ne_zero.mpr bN0
have bq0 : (0 : ℝ) < b * q := mul_pos (Nat.cast_pos.mpr bN0.bot_lt) qR0
-- At a1, clear denominators...
replace a1 : |a * q - b * p| * q ^ (b + 1) < b * q := by
rw [div_sub_div _ _ b0 qR0.ne', abs_div, div_lt_div_iff (abs_pos.mpr bq0.ne') (pow_pos qR0 _),
abs_of_pos bq0, one_mul] at a1
exact mod_cast a1
-- At a0, clear denominators...
replace a0 : a * q - ↑b * p ≠ 0 := by
rw [Ne, div_eq_div_iff b0 qR0.ne', mul_comm (p : ℝ), ← sub_eq_zero] at a0
exact mod_cast a0
-- Actually, `q` is a natural number
lift q to ℕ using (zero_lt_one.trans q1).le
-- Looks innocuous, but we now have an integer with non-zero absolute value: this is at
-- least one away from zero. The gain here is what gets the proof going.
have ap : 0 < |a * ↑q - ↑b * p| := abs_pos.mpr a0
-- Actually, the absolute value of an integer is a natural number
-- FIXME: This `lift` call duplicates the hypotheses `a1` and `ap`
lift |a * ↑q - ↑b * p| to ℕ using abs_nonneg (a * ↑q - ↑b * p) with e he
norm_cast at a1 ap q1
-- Recall this is by contradiction: we obtained the inequality `b * q ≤ x * q ^ (b + 1)`, so
-- we are done.
exact not_le.mpr a1 (Nat.mul_lt_mul_pow_succ ap q1).le
#align liouville.irrational Liouville.irrational
open Polynomial Metric Set Real RingHom
open scoped Polynomial
theorem exists_one_le_pow_mul_dist {Z N R : Type*} [PseudoMetricSpace R] {d : N → ℝ}
{j : Z → N → R} {f : R → R} {α : R} {ε M : ℝ}
-- denominators are positive
(d0 : ∀ a : N, 1 ≤ d a)
(e0 : 0 < ε)
-- function is Lipschitz at α
(B : ∀ ⦃y : R⦄, y ∈ closedBall α ε → dist (f α) (f y) ≤ dist α y * M)
-- clear denominators
(L : ∀ ⦃z : Z⦄, ∀ ⦃a : N⦄, j z a ∈ closedBall α ε → 1 ≤ d a * dist (f α) (f (j z a))) :
∃ A : ℝ, 0 < A ∧ ∀ z : Z, ∀ a : N, 1 ≤ d a * (dist α (j z a) * A) := by
-- A useful inequality to keep at hand
have me0 : 0 < max (1 / ε) M := lt_max_iff.mpr (Or.inl (one_div_pos.mpr e0))
-- The maximum between `1 / ε` and `M` works
refine ⟨max (1 / ε) M, me0, fun z a => ?_⟩
-- First, let's deal with the easy case in which we are far away from `α`
by_cases dm1 : 1 ≤ dist α (j z a) * max (1 / ε) M
· exact one_le_mul_of_one_le_of_one_le (d0 a) dm1
· -- `j z a = z / (a + 1)`: we prove that this ratio is close to `α`
have : j z a ∈ closedBall α ε := by
refine mem_closedBall'.mp (le_trans ?_ ((one_div_le me0 e0).mpr (le_max_left _ _)))
exact (le_div_iff me0).mpr (not_le.mp dm1).le
-- use the "separation from `1`" (assumption `L`) for numerators,
refine (L this).trans ?_
-- remove a common factor and use the Lipschitz assumption `B`
refine mul_le_mul_of_nonneg_left ((B this).trans ?_) (zero_le_one.trans (d0 a))
exact mul_le_mul_of_nonneg_left (le_max_right _ M) dist_nonneg
#align liouville.exists_one_le_pow_mul_dist Liouville.exists_one_le_pow_mul_dist
| Mathlib/NumberTheory/Liouville/Basic.lean | 123 | 173 | theorem exists_pos_real_of_irrational_root {α : ℝ} (ha : Irrational α) {f : ℤ[X]} (f0 : f ≠ 0)
(fa : eval α (map (algebraMap ℤ ℝ) f) = 0) :
∃ A : ℝ, 0 < A ∧ ∀ a : ℤ, ∀ b : ℕ,
(1 : ℝ) ≤ ((b : ℝ) + 1) ^ f.natDegree * (|α - a / (b + 1)| * A) := by |
-- `fR` is `f` viewed as a polynomial with `ℝ` coefficients.
set fR : ℝ[X] := map (algebraMap ℤ ℝ) f
-- `fR` is non-zero, since `f` is non-zero.
obtain fR0 : fR ≠ 0 := fun fR0 =>
(map_injective (algebraMap ℤ ℝ) fun _ _ A => Int.cast_inj.mp A).ne f0
(fR0.trans (Polynomial.map_zero _).symm)
-- reformulating assumption `fa`: `α` is a root of `fR`.
have ar : α ∈ (fR.roots.toFinset : Set ℝ) :=
Finset.mem_coe.mpr (Multiset.mem_toFinset.mpr ((mem_roots fR0).mpr (IsRoot.def.mpr fa)))
-- Since the polynomial `fR` has finitely many roots, there is a closed interval centered at `α`
-- such that `α` is the only root of `fR` in the interval.
obtain ⟨ζ, z0, U⟩ : ∃ ζ > 0, closedBall α ζ ∩ fR.roots.toFinset = {α} :=
@exists_closedBall_inter_eq_singleton_of_discrete _ _ _ discrete_of_t1_of_finite _ ar
-- Since `fR` is continuous, it is bounded on the interval above.
obtain ⟨xm, -, hM⟩ : ∃ xm : ℝ, xm ∈ Icc (α - ζ) (α + ζ) ∧
IsMaxOn (|fR.derivative.eval ·|) (Icc (α - ζ) (α + ζ)) xm :=
IsCompact.exists_isMaxOn isCompact_Icc
⟨α, (sub_lt_self α z0).le, (lt_add_of_pos_right α z0).le⟩
(continuous_abs.comp fR.derivative.continuous_aeval).continuousOn
-- Use the key lemma `exists_one_le_pow_mul_dist`: we are left to show that ...
refine
@exists_one_le_pow_mul_dist ℤ ℕ ℝ _ _ _ (fun y => fR.eval y) α ζ |fR.derivative.eval xm| ?_ z0
(fun y hy => ?_) fun z a hq => ?_
-- 1: the denominators are positive -- essentially by definition;
· exact fun a => one_le_pow_of_one_le ((le_add_iff_nonneg_left 1).mpr a.cast_nonneg) _
-- 2: the polynomial `fR` is Lipschitz at `α` -- as its derivative continuous;
· rw [mul_comm]
rw [Real.closedBall_eq_Icc] at hy
-- apply the Mean Value Theorem: the bound on the derivative comes from differentiability.
refine
Convex.norm_image_sub_le_of_norm_deriv_le (fun _ _ => fR.differentiableAt)
(fun y h => by rw [fR.deriv]; exact hM h) (convex_Icc _ _) hy (mem_Icc_iff_abs_le.mp ?_)
exact @mem_closedBall_self ℝ _ α ζ (le_of_lt z0)
-- 3: the weird inequality of Liouville type with powers of the denominators.
· show 1 ≤ (a + 1 : ℝ) ^ f.natDegree * |eval α fR - eval ((z : ℝ) / (a + 1)) fR|
rw [fa, zero_sub, abs_neg]
rw [show (a + 1 : ℝ) = ((a + 1 : ℕ) : ℤ) by norm_cast] at hq ⊢
-- key observation: the right-hand side of the inequality is an *integer*. Therefore,
-- if its absolute value is not at least one, then it vanishes. Proceed by contradiction
refine one_le_pow_mul_abs_eval_div (Int.natCast_succ_pos a) fun hy => ?_
-- As the evaluation of the polynomial vanishes, we found a root of `fR` that is rational.
-- We know that `α` is the only root of `fR` in our interval, and `α` is irrational:
-- follow your nose.
refine (irrational_iff_ne_rational α).mp ha z (a + 1) (mem_singleton_iff.mp ?_).symm
refine U.subset ?_
refine ⟨hq, Finset.mem_coe.mp (Multiset.mem_toFinset.mpr ?_)⟩
exact (mem_roots fR0).mpr (IsRoot.def.mpr hy)
|
import Mathlib.Algebra.Order.Ring.Abs
#align_import data.int.order.units from "leanprover-community/mathlib"@"d012cd09a9b256d870751284dd6a29882b0be105"
namespace Int
theorem isUnit_iff_abs_eq {x : ℤ} : IsUnit x ↔ abs x = 1 := by
rw [isUnit_iff_natAbs_eq, abs_eq_natAbs, ← Int.ofNat_one, natCast_inj]
#align int.is_unit_iff_abs_eq Int.isUnit_iff_abs_eq
theorem isUnit_sq {a : ℤ} (ha : IsUnit a) : a ^ 2 = 1 := by rw [sq, isUnit_mul_self ha]
#align int.is_unit_sq Int.isUnit_sq
@[simp]
theorem units_sq (u : ℤˣ) : u ^ 2 = 1 := by
rw [Units.ext_iff, Units.val_pow_eq_pow_val, Units.val_one, isUnit_sq u.isUnit]
#align int.units_sq Int.units_sq
alias units_pow_two := units_sq
#align int.units_pow_two Int.units_pow_two
@[simp]
theorem units_mul_self (u : ℤˣ) : u * u = 1 := by rw [← sq, units_sq]
#align int.units_mul_self Int.units_mul_self
@[simp]
theorem units_inv_eq_self (u : ℤˣ) : u⁻¹ = u := by rw [inv_eq_iff_mul_eq_one, units_mul_self]
#align int.units_inv_eq_self Int.units_inv_eq_self
theorem units_div_eq_mul (u₁ u₂ : ℤˣ) : u₁ / u₂ = u₁ * u₂ := by
rw [div_eq_mul_inv, units_inv_eq_self]
-- `Units.val_mul` is a "wrong turn" for the simplifier, this undoes it and simplifies further
@[simp]
theorem units_coe_mul_self (u : ℤˣ) : (u * u : ℤ) = 1 := by
rw [← Units.val_mul, units_mul_self, Units.val_one]
#align int.units_coe_mul_self Int.units_coe_mul_self
| Mathlib/Data/Int/Order/Units.lean | 49 | 49 | theorem neg_one_pow_ne_zero {n : ℕ} : (-1 : ℤ) ^ n ≠ 0 := by | simp
|
import Mathlib.Analysis.Analytic.Basic
import Mathlib.Analysis.Complex.Basic
import Mathlib.Analysis.Normed.Field.InfiniteSum
import Mathlib.Data.Nat.Choose.Cast
import Mathlib.Data.Finset.NoncommProd
import Mathlib.Topology.Algebra.Algebra
#align_import analysis.normed_space.exponential from "leanprover-community/mathlib"@"62748956a1ece9b26b33243e2e3a2852176666f5"
namespace NormedSpace
open Filter RCLike ContinuousMultilinearMap NormedField Asymptotics
open scoped Nat Topology ENNReal
section TopologicalAlgebra
variable (𝕂 𝔸 : Type*) [Field 𝕂] [Ring 𝔸] [Algebra 𝕂 𝔸] [TopologicalSpace 𝔸] [TopologicalRing 𝔸]
def expSeries : FormalMultilinearSeries 𝕂 𝔸 𝔸 := fun n =>
(n !⁻¹ : 𝕂) • ContinuousMultilinearMap.mkPiAlgebraFin 𝕂 n 𝔸
#align exp_series NormedSpace.expSeries
variable {𝔸}
noncomputable def exp (x : 𝔸) : 𝔸 :=
(expSeries 𝕂 𝔸).sum x
#align exp NormedSpace.exp
variable {𝕂}
theorem expSeries_apply_eq (x : 𝔸) (n : ℕ) :
(expSeries 𝕂 𝔸 n fun _ => x) = (n !⁻¹ : 𝕂) • x ^ n := by simp [expSeries]
#align exp_series_apply_eq NormedSpace.expSeries_apply_eq
theorem expSeries_apply_eq' (x : 𝔸) :
(fun n => expSeries 𝕂 𝔸 n fun _ => x) = fun n => (n !⁻¹ : 𝕂) • x ^ n :=
funext (expSeries_apply_eq x)
#align exp_series_apply_eq' NormedSpace.expSeries_apply_eq'
theorem expSeries_sum_eq (x : 𝔸) : (expSeries 𝕂 𝔸).sum x = ∑' n : ℕ, (n !⁻¹ : 𝕂) • x ^ n :=
tsum_congr fun n => expSeries_apply_eq x n
#align exp_series_sum_eq NormedSpace.expSeries_sum_eq
theorem exp_eq_tsum : exp 𝕂 = fun x : 𝔸 => ∑' n : ℕ, (n !⁻¹ : 𝕂) • x ^ n :=
funext expSeries_sum_eq
#align exp_eq_tsum NormedSpace.exp_eq_tsum
theorem expSeries_apply_zero (n : ℕ) :
(expSeries 𝕂 𝔸 n fun _ => (0 : 𝔸)) = Pi.single (f := fun _ => 𝔸) 0 1 n := by
rw [expSeries_apply_eq]
cases' n with n
· rw [pow_zero, Nat.factorial_zero, Nat.cast_one, inv_one, one_smul, Pi.single_eq_same]
· rw [zero_pow (Nat.succ_ne_zero _), smul_zero, Pi.single_eq_of_ne n.succ_ne_zero]
#align exp_series_apply_zero NormedSpace.expSeries_apply_zero
@[simp]
theorem exp_zero : exp 𝕂 (0 : 𝔸) = 1 := by
simp_rw [exp_eq_tsum, ← expSeries_apply_eq, expSeries_apply_zero, tsum_pi_single]
#align exp_zero NormedSpace.exp_zero
@[simp]
theorem exp_op [T2Space 𝔸] (x : 𝔸) : exp 𝕂 (MulOpposite.op x) = MulOpposite.op (exp 𝕂 x) := by
simp_rw [exp, expSeries_sum_eq, ← MulOpposite.op_pow, ← MulOpposite.op_smul, tsum_op]
#align exp_op NormedSpace.exp_op
@[simp]
theorem exp_unop [T2Space 𝔸] (x : 𝔸ᵐᵒᵖ) :
exp 𝕂 (MulOpposite.unop x) = MulOpposite.unop (exp 𝕂 x) := by
simp_rw [exp, expSeries_sum_eq, ← MulOpposite.unop_pow, ← MulOpposite.unop_smul, tsum_unop]
#align exp_unop NormedSpace.exp_unop
theorem star_exp [T2Space 𝔸] [StarRing 𝔸] [ContinuousStar 𝔸] (x : 𝔸) :
star (exp 𝕂 x) = exp 𝕂 (star x) := by
simp_rw [exp_eq_tsum, ← star_pow, ← star_inv_natCast_smul, ← tsum_star]
#align star_exp NormedSpace.star_exp
variable (𝕂)
theorem _root_.IsSelfAdjoint.exp [T2Space 𝔸] [StarRing 𝔸] [ContinuousStar 𝔸] {x : 𝔸}
(h : IsSelfAdjoint x) : IsSelfAdjoint (exp 𝕂 x) :=
(star_exp x).trans <| h.symm ▸ rfl
#align is_self_adjoint.exp IsSelfAdjoint.exp
| Mathlib/Analysis/NormedSpace/Exponential.lean | 172 | 175 | theorem _root_.Commute.exp_right [T2Space 𝔸] {x y : 𝔸} (h : Commute x y) :
Commute x (exp 𝕂 y) := by |
rw [exp_eq_tsum]
exact Commute.tsum_right x fun n => (h.pow_right n).smul_right _
|
import Mathlib.Algebra.CharP.ExpChar
import Mathlib.GroupTheory.OrderOfElement
#align_import algebra.char_p.two from "leanprover-community/mathlib"@"7f1ba1a333d66eed531ecb4092493cd1b6715450"
variable {R ι : Type*}
namespace CharTwo
section Semiring
variable [Semiring R] [CharP R 2]
theorem two_eq_zero : (2 : R) = 0 := by rw [← Nat.cast_two, CharP.cast_eq_zero]
#align char_two.two_eq_zero CharTwo.two_eq_zero
@[simp]
| Mathlib/Algebra/CharP/Two.lean | 33 | 33 | theorem add_self_eq_zero (x : R) : x + x = 0 := by | rw [← two_smul R x, two_eq_zero, zero_smul]
|
import Mathlib.LinearAlgebra.Dual
open Function Module
variable (R M N : Type*) [CommRing R] [AddCommGroup M] [Module R M] [AddCommGroup N] [Module R N]
structure PerfectPairing :=
toLin : M →ₗ[R] N →ₗ[R] R
bijectiveLeft : Bijective toLin
bijectiveRight : Bijective toLin.flip
attribute [nolint docBlame] PerfectPairing.toLin
variable {R M N}
namespace PerfectPairing
instance instFunLike : FunLike (PerfectPairing R M N) M (N →ₗ[R] R) where
coe f := f.toLin
coe_injective' x y h := by cases x; cases y; simpa using h
variable (p : PerfectPairing R M N)
protected def flip : PerfectPairing R N M where
toLin := p.toLin.flip
bijectiveLeft := p.bijectiveRight
bijectiveRight := p.bijectiveLeft
@[simp] lemma flip_flip : p.flip.flip = p := rfl
noncomputable def toDualLeft : M ≃ₗ[R] Dual R N :=
LinearEquiv.ofBijective p.toLin p.bijectiveLeft
@[simp]
theorem toDualLeft_apply (a : M) : p.toDualLeft a = p a :=
rfl
@[simp]
| Mathlib/LinearAlgebra/PerfectPairing.lean | 71 | 74 | theorem apply_toDualLeft_symm_apply (f : Dual R N) (x : N) : p (p.toDualLeft.symm f) x = f x := by |
have h := LinearEquiv.apply_symm_apply p.toDualLeft f
rw [toDualLeft_apply] at h
exact congrFun (congrArg DFunLike.coe h) x
|
import Mathlib.Topology.UniformSpace.CompactConvergence
import Mathlib.Topology.UniformSpace.Equicontinuity
import Mathlib.Topology.UniformSpace.Equiv
open Set Filter Uniformity Topology Function UniformConvergence
variable {ι X Y α β : Type*} [TopologicalSpace X] [UniformSpace α] [UniformSpace β]
variable {F : ι → X → α} {G : ι → β → α}
| Mathlib/Topology/UniformSpace/Ascoli.lean | 85 | 125 | theorem Equicontinuous.comap_uniformFun_eq [CompactSpace X] (F_eqcont : Equicontinuous F) :
(UniformFun.uniformSpace X α).comap F =
(Pi.uniformSpace _).comap F := by |
-- The `≤` inequality is trivial
refine le_antisymm (UniformSpace.comap_mono UniformFun.uniformContinuous_toFun) ?_
-- A bit of rewriting to get a nice intermediate statement.
change comap _ _ ≤ comap _ _
simp_rw [Pi.uniformity, Filter.comap_iInf, comap_comap, Function.comp]
refine ((UniformFun.hasBasis_uniformity X α).comap (Prod.map F F)).ge_iff.mpr ?_
-- Core of the proof: we need to show that, for any entourage `U` in `α`,
-- the set `𝐓(U) := {(i,j) : ι × ι | ∀ x : X, (F i x, F j x) ∈ U}` belongs to the filter
-- `⨅ x, comap ((i,j) ↦ (F i x, F j x)) (𝓤 α)`.
-- In other words, we have to show that it contains a finite intersection of
-- sets of the form `𝐒(V, x) := {(i,j) : ι × ι | (F i x, F j x) ∈ V}` for some
-- `x : X` and `V ∈ 𝓤 α`.
intro U hU
-- We will do an `ε/3` argument, so we start by choosing a symmetric entourage `V ∈ 𝓤 α`
-- such that `V ○ V ○ V ⊆ U`.
rcases comp_comp_symm_mem_uniformity_sets hU with ⟨V, hV, Vsymm, hVU⟩
-- Set `Ω x := {y | ∀ i, (F i x, F i y) ∈ V}`. The equicontinuity of `F` guarantees that
-- each `Ω x` is a neighborhood of `x`.
let Ω x : Set X := {y | ∀ i, (F i x, F i y) ∈ V}
-- Hence, by compactness of `X`, we can find some `A ⊆ X` finite such that the `Ω a`s for `a ∈ A`
-- still cover `X`.
rcases CompactSpace.elim_nhds_subcover Ω (fun x ↦ F_eqcont x V hV) with ⟨A, Acover⟩
-- We now claim that `⋂ a ∈ A, 𝐒(V, a) ⊆ 𝐓(U)`.
have : (⋂ a ∈ A, {ij : ι × ι | (F ij.1 a, F ij.2 a) ∈ V}) ⊆
(Prod.map F F) ⁻¹' UniformFun.gen X α U := by
-- Given `(i, j) ∈ ⋂ a ∈ A, 𝐒(V, a)` and `x : X`, we have to prove that `(F i x, F j x) ∈ U`.
rintro ⟨i, j⟩ hij x
rw [mem_iInter₂] at hij
-- We know that `x ∈ Ω a` for some `a ∈ A`, so that both `(F i x, F i a)` and `(F j a, F j x)`
-- are in `V`.
rcases mem_iUnion₂.mp (Acover.symm.subset <| mem_univ x) with ⟨a, ha, hax⟩
-- Since `(i, j) ∈ 𝐒(V, a)` we also have `(F i a, F j a) ∈ V`, and finally we get
-- `(F i x, F j x) ∈ V ○ V ○ V ⊆ U`.
exact hVU (prod_mk_mem_compRel (prod_mk_mem_compRel
(Vsymm.mk_mem_comm.mp (hax i)) (hij a ha)) (hax j))
-- This completes the proof.
exact mem_of_superset
(A.iInter_mem_sets.mpr fun x _ ↦ mem_iInf_of_mem x <| preimage_mem_comap hV) this
|
import Mathlib.Algebra.Polynomial.Mirror
import Mathlib.Analysis.Complex.Polynomial
#align_import data.polynomial.unit_trinomial from "leanprover-community/mathlib"@"302eab4f46abb63de520828de78c04cb0f9b5836"
namespace Polynomial
open scoped Polynomial
open Finset
section Semiring
variable {R : Type*} [Semiring R] (k m n : ℕ) (u v w : R)
noncomputable def trinomial :=
C u * X ^ k + C v * X ^ m + C w * X ^ n
#align polynomial.trinomial Polynomial.trinomial
theorem trinomial_def : trinomial k m n u v w = C u * X ^ k + C v * X ^ m + C w * X ^ n :=
rfl
#align polynomial.trinomial_def Polynomial.trinomial_def
variable {k m n u v w}
theorem trinomial_leading_coeff' (hkm : k < m) (hmn : m < n) :
(trinomial k m n u v w).coeff n = w := by
rw [trinomial_def, coeff_add, coeff_add, coeff_C_mul_X_pow, coeff_C_mul_X_pow, coeff_C_mul_X_pow,
if_neg (hkm.trans hmn).ne', if_neg hmn.ne', if_pos rfl, zero_add, zero_add]
#align polynomial.trinomial_leading_coeff' Polynomial.trinomial_leading_coeff'
theorem trinomial_middle_coeff (hkm : k < m) (hmn : m < n) :
(trinomial k m n u v w).coeff m = v := by
rw [trinomial_def, coeff_add, coeff_add, coeff_C_mul_X_pow, coeff_C_mul_X_pow, coeff_C_mul_X_pow,
if_neg hkm.ne', if_pos rfl, if_neg hmn.ne, zero_add, add_zero]
#align polynomial.trinomial_middle_coeff Polynomial.trinomial_middle_coeff
theorem trinomial_trailing_coeff' (hkm : k < m) (hmn : m < n) :
(trinomial k m n u v w).coeff k = u := by
rw [trinomial_def, coeff_add, coeff_add, coeff_C_mul_X_pow, coeff_C_mul_X_pow, coeff_C_mul_X_pow,
if_pos rfl, if_neg hkm.ne, if_neg (hkm.trans hmn).ne, add_zero, add_zero]
#align polynomial.trinomial_trailing_coeff' Polynomial.trinomial_trailing_coeff'
| Mathlib/Algebra/Polynomial/UnitTrinomial.lean | 67 | 78 | theorem trinomial_natDegree (hkm : k < m) (hmn : m < n) (hw : w ≠ 0) :
(trinomial k m n u v w).natDegree = n := by |
refine
natDegree_eq_of_degree_eq_some
((Finset.sup_le fun i h => ?_).antisymm <|
le_degree_of_ne_zero <| by rwa [trinomial_leading_coeff' hkm hmn])
replace h := support_trinomial' k m n u v w h
rw [mem_insert, mem_insert, mem_singleton] at h
rcases h with (rfl | rfl | rfl)
· exact WithBot.coe_le_coe.mpr (hkm.trans hmn).le
· exact WithBot.coe_le_coe.mpr hmn.le
· exact le_rfl
|
import Mathlib.Order.BooleanAlgebra
import Mathlib.Logic.Equiv.Basic
#align_import order.symm_diff from "leanprover-community/mathlib"@"6eb334bd8f3433d5b08ba156b8ec3e6af47e1904"
open Function OrderDual
variable {ι α β : Type*} {π : ι → Type*}
def symmDiff [Sup α] [SDiff α] (a b : α) : α :=
a \ b ⊔ b \ a
#align symm_diff symmDiff
def bihimp [Inf α] [HImp α] (a b : α) : α :=
(b ⇨ a) ⊓ (a ⇨ b)
#align bihimp bihimp
scoped[symmDiff] infixl:100 " ∆ " => symmDiff
scoped[symmDiff] infixl:100 " ⇔ " => bihimp
open scoped symmDiff
theorem symmDiff_def [Sup α] [SDiff α] (a b : α) : a ∆ b = a \ b ⊔ b \ a :=
rfl
#align symm_diff_def symmDiff_def
theorem bihimp_def [Inf α] [HImp α] (a b : α) : a ⇔ b = (b ⇨ a) ⊓ (a ⇨ b) :=
rfl
#align bihimp_def bihimp_def
theorem symmDiff_eq_Xor' (p q : Prop) : p ∆ q = Xor' p q :=
rfl
#align symm_diff_eq_xor symmDiff_eq_Xor'
@[simp]
theorem bihimp_iff_iff {p q : Prop} : p ⇔ q ↔ (p ↔ q) :=
(iff_iff_implies_and_implies _ _).symm.trans Iff.comm
#align bihimp_iff_iff bihimp_iff_iff
@[simp]
| Mathlib/Order/SymmDiff.lean | 96 | 96 | theorem Bool.symmDiff_eq_xor : ∀ p q : Bool, p ∆ q = xor p q := by | decide
|
import Mathlib.Topology.Homeomorph
import Mathlib.Topology.Order.LeftRightNhds
#align_import topology.algebra.order.monotone_continuity from "leanprover-community/mathlib"@"4c19a16e4b705bf135cf9a80ac18fcc99c438514"
open Set Filter
open Topology
section LinearOrder
variable {α β : Type*} [LinearOrder α] [TopologicalSpace α] [OrderTopology α]
variable [LinearOrder β] [TopologicalSpace β] [OrderTopology β]
theorem StrictMonoOn.continuousWithinAt_right_of_exists_between {f : α → β} {s : Set α} {a : α}
(h_mono : StrictMonoOn f s) (hs : s ∈ 𝓝[≥] a) (hfs : ∀ b > f a, ∃ c ∈ s, f c ∈ Ioc (f a) b) :
ContinuousWithinAt f (Ici a) a := by
have ha : a ∈ Ici a := left_mem_Ici
have has : a ∈ s := mem_of_mem_nhdsWithin ha hs
refine tendsto_order.2 ⟨fun b hb => ?_, fun b hb => ?_⟩
· filter_upwards [hs, @self_mem_nhdsWithin _ _ a (Ici a)] with _ hxs hxa using hb.trans_le
((h_mono.le_iff_le has hxs).2 hxa)
· rcases hfs b hb with ⟨c, hcs, hac, hcb⟩
rw [h_mono.lt_iff_lt has hcs] at hac
filter_upwards [hs, Ico_mem_nhdsWithin_Ici (left_mem_Ico.2 hac)]
rintro x hx ⟨_, hxc⟩
exact ((h_mono.lt_iff_lt hx hcs).2 hxc).trans_le hcb
#align strict_mono_on.continuous_at_right_of_exists_between StrictMonoOn.continuousWithinAt_right_of_exists_between
| Mathlib/Topology/Order/MonotoneContinuity.lean | 63 | 75 | theorem continuousWithinAt_right_of_monotoneOn_of_exists_between {f : α → β} {s : Set α} {a : α}
(h_mono : MonotoneOn f s) (hs : s ∈ 𝓝[≥] a) (hfs : ∀ b > f a, ∃ c ∈ s, f c ∈ Ioo (f a) b) :
ContinuousWithinAt f (Ici a) a := by |
have ha : a ∈ Ici a := left_mem_Ici
have has : a ∈ s := mem_of_mem_nhdsWithin ha hs
refine tendsto_order.2 ⟨fun b hb => ?_, fun b hb => ?_⟩
· filter_upwards [hs, @self_mem_nhdsWithin _ _ a (Ici a)] with _ hxs hxa using hb.trans_le
(h_mono has hxs hxa)
· rcases hfs b hb with ⟨c, hcs, hac, hcb⟩
have : a < c := not_le.1 fun h => hac.not_le <| h_mono hcs has h
filter_upwards [hs, Ico_mem_nhdsWithin_Ici (left_mem_Ico.2 this)]
rintro x hx ⟨_, hxc⟩
exact (h_mono hx hcs hxc.le).trans_lt hcb
|
import Batteries.Data.List.Basic
import Batteries.Data.List.Lemmas
open Nat
namespace List
section countP
variable (p q : α → Bool)
@[simp] theorem countP_nil : countP p [] = 0 := rfl
protected theorem countP_go_eq_add (l) : countP.go p l n = n + countP.go p l 0 := by
induction l generalizing n with
| nil => rfl
| cons head tail ih =>
unfold countP.go
rw [ih (n := n + 1), ih (n := n), ih (n := 1)]
if h : p head then simp [h, Nat.add_assoc] else simp [h]
@[simp] theorem countP_cons_of_pos (l) (pa : p a) : countP p (a :: l) = countP p l + 1 := by
have : countP.go p (a :: l) 0 = countP.go p l 1 := show cond .. = _ by rw [pa]; rfl
unfold countP
rw [this, Nat.add_comm, List.countP_go_eq_add]
@[simp] theorem countP_cons_of_neg (l) (pa : ¬p a) : countP p (a :: l) = countP p l := by
simp [countP, countP.go, pa]
theorem countP_cons (a : α) (l) : countP p (a :: l) = countP p l + if p a then 1 else 0 := by
by_cases h : p a <;> simp [h]
theorem length_eq_countP_add_countP (l) : length l = countP p l + countP (fun a => ¬p a) l := by
induction l with
| nil => rfl
| cons x h ih =>
if h : p x then
rw [countP_cons_of_pos _ _ h, countP_cons_of_neg _ _ _, length, ih]
· rw [Nat.add_assoc, Nat.add_comm _ 1, Nat.add_assoc]
· simp only [h, not_true_eq_false, decide_False, not_false_eq_true]
else
rw [countP_cons_of_pos (fun a => ¬p a) _ _, countP_cons_of_neg _ _ h, length, ih]
· rfl
· simp only [h, not_false_eq_true, decide_True]
theorem countP_eq_length_filter (l) : countP p l = length (filter p l) := by
induction l with
| nil => rfl
| cons x l ih =>
if h : p x
then rw [countP_cons_of_pos p l h, ih, filter_cons_of_pos l h, length]
else rw [countP_cons_of_neg p l h, ih, filter_cons_of_neg l h]
theorem countP_le_length : countP p l ≤ l.length := by
simp only [countP_eq_length_filter]
apply length_filter_le
@[simp] theorem countP_append (l₁ l₂) : countP p (l₁ ++ l₂) = countP p l₁ + countP p l₂ := by
simp only [countP_eq_length_filter, filter_append, length_append]
theorem countP_pos : 0 < countP p l ↔ ∃ a ∈ l, p a := by
simp only [countP_eq_length_filter, length_pos_iff_exists_mem, mem_filter, exists_prop]
theorem countP_eq_zero : countP p l = 0 ↔ ∀ a ∈ l, ¬p a := by
simp only [countP_eq_length_filter, length_eq_zero, filter_eq_nil]
| .lake/packages/batteries/Batteries/Data/List/Count.lean | 81 | 82 | theorem countP_eq_length : countP p l = l.length ↔ ∀ a ∈ l, p a := by |
rw [countP_eq_length_filter, filter_length_eq_length]
|
import Mathlib.Algebra.Polynomial.AlgebraMap
import Mathlib.Algebra.Polynomial.Degree.Lemmas
import Mathlib.Algebra.Polynomial.HasseDeriv
#align_import data.polynomial.taylor from "leanprover-community/mathlib"@"70fd9563a21e7b963887c9360bd29b2393e6225a"
noncomputable section
namespace Polynomial
open Polynomial
variable {R : Type*} [Semiring R] (r : R) (f : R[X])
def taylor (r : R) : R[X] →ₗ[R] R[X] where
toFun f := f.comp (X + C r)
map_add' f g := add_comp
map_smul' c f := by simp only [smul_eq_C_mul, C_mul_comp, RingHom.id_apply]
#align polynomial.taylor Polynomial.taylor
theorem taylor_apply : taylor r f = f.comp (X + C r) :=
rfl
#align polynomial.taylor_apply Polynomial.taylor_apply
@[simp]
theorem taylor_X : taylor r X = X + C r := by simp only [taylor_apply, X_comp]
set_option linter.uppercaseLean3 false in
#align polynomial.taylor_X Polynomial.taylor_X
@[simp]
theorem taylor_C (x : R) : taylor r (C x) = C x := by simp only [taylor_apply, C_comp]
set_option linter.uppercaseLean3 false in
#align polynomial.taylor_C Polynomial.taylor_C
@[simp]
theorem taylor_zero' : taylor (0 : R) = LinearMap.id := by
ext
simp only [taylor_apply, add_zero, comp_X, _root_.map_zero, LinearMap.id_comp,
Function.comp_apply, LinearMap.coe_comp]
#align polynomial.taylor_zero' Polynomial.taylor_zero'
theorem taylor_zero (f : R[X]) : taylor 0 f = f := by rw [taylor_zero', LinearMap.id_apply]
#align polynomial.taylor_zero Polynomial.taylor_zero
@[simp]
theorem taylor_one : taylor r (1 : R[X]) = C 1 := by rw [← C_1, taylor_C]
#align polynomial.taylor_one Polynomial.taylor_one
@[simp]
theorem taylor_monomial (i : ℕ) (k : R) : taylor r (monomial i k) = C k * (X + C r) ^ i := by
simp [taylor_apply]
#align polynomial.taylor_monomial Polynomial.taylor_monomial
theorem taylor_coeff (n : ℕ) : (taylor r f).coeff n = (hasseDeriv n f).eval r :=
show (lcoeff R n).comp (taylor r) f = (leval r).comp (hasseDeriv n) f by
congr 1; clear! f; ext i
simp only [leval_apply, mul_one, one_mul, eval_monomial, LinearMap.comp_apply, coeff_C_mul,
hasseDeriv_monomial, taylor_apply, monomial_comp, C_1, (commute_X (C r)).add_pow i,
map_sum]
simp only [lcoeff_apply, ← C_eq_natCast, mul_assoc, ← C_pow, ← C_mul, coeff_mul_C,
(Nat.cast_commute _ _).eq, coeff_X_pow, boole_mul, Finset.sum_ite_eq, Finset.mem_range]
split_ifs with h; · rfl
push_neg at h; rw [Nat.choose_eq_zero_of_lt h, Nat.cast_zero, mul_zero]
#align polynomial.taylor_coeff Polynomial.taylor_coeff
@[simp]
theorem taylor_coeff_zero : (taylor r f).coeff 0 = f.eval r := by
rw [taylor_coeff, hasseDeriv_zero, LinearMap.id_apply]
#align polynomial.taylor_coeff_zero Polynomial.taylor_coeff_zero
@[simp]
| Mathlib/Algebra/Polynomial/Taylor.lean | 93 | 94 | theorem taylor_coeff_one : (taylor r f).coeff 1 = f.derivative.eval r := by |
rw [taylor_coeff, hasseDeriv_one]
|
import Mathlib.Data.Finset.Fold
import Mathlib.Algebra.GCDMonoid.Multiset
#align_import algebra.gcd_monoid.finset from "leanprover-community/mathlib"@"9003f28797c0664a49e4179487267c494477d853"
#align_import algebra.gcd_monoid.div from "leanprover-community/mathlib"@"b537794f8409bc9598febb79cd510b1df5f4539d"
variable {ι α β γ : Type*}
namespace Finset
open Multiset
variable [CancelCommMonoidWithZero α] [NormalizedGCDMonoid α]
section gcd
def gcd (s : Finset β) (f : β → α) : α :=
s.fold GCDMonoid.gcd 0 f
#align finset.gcd Finset.gcd
variable {s s₁ s₂ : Finset β} {f : β → α}
theorem gcd_def : s.gcd f = (s.1.map f).gcd :=
rfl
#align finset.gcd_def Finset.gcd_def
@[simp]
theorem gcd_empty : (∅ : Finset β).gcd f = 0 :=
fold_empty
#align finset.gcd_empty Finset.gcd_empty
theorem dvd_gcd_iff {a : α} : a ∣ s.gcd f ↔ ∀ b ∈ s, a ∣ f b := by
apply Iff.trans Multiset.dvd_gcd
simp only [Multiset.mem_map, and_imp, exists_imp]
exact ⟨fun k b hb ↦ k _ _ hb rfl, fun k a' b hb h ↦ h ▸ k _ hb⟩
#align finset.dvd_gcd_iff Finset.dvd_gcd_iff
theorem gcd_dvd {b : β} (hb : b ∈ s) : s.gcd f ∣ f b :=
dvd_gcd_iff.1 dvd_rfl _ hb
#align finset.gcd_dvd Finset.gcd_dvd
theorem dvd_gcd {a : α} : (∀ b ∈ s, a ∣ f b) → a ∣ s.gcd f :=
dvd_gcd_iff.2
#align finset.dvd_gcd Finset.dvd_gcd
@[simp]
theorem gcd_insert [DecidableEq β] {b : β} :
(insert b s : Finset β).gcd f = GCDMonoid.gcd (f b) (s.gcd f) := by
by_cases h : b ∈ s
· rw [insert_eq_of_mem h,
(gcd_eq_right_iff (f b) (s.gcd f) (Multiset.normalize_gcd (s.1.map f))).2 (gcd_dvd h)]
apply fold_insert h
#align finset.gcd_insert Finset.gcd_insert
@[simp]
theorem gcd_singleton {b : β} : ({b} : Finset β).gcd f = normalize (f b) :=
Multiset.gcd_singleton
#align finset.gcd_singleton Finset.gcd_singleton
-- Porting note: Priority changed for `simpNF`
@[simp 1100]
theorem normalize_gcd : normalize (s.gcd f) = s.gcd f := by simp [gcd_def]
#align finset.normalize_gcd Finset.normalize_gcd
theorem gcd_union [DecidableEq β] : (s₁ ∪ s₂).gcd f = GCDMonoid.gcd (s₁.gcd f) (s₂.gcd f) :=
Finset.induction_on s₁ (by rw [empty_union, gcd_empty, gcd_zero_left, normalize_gcd])
fun a s _ ih ↦ by rw [insert_union, gcd_insert, gcd_insert, ih, gcd_assoc]
#align finset.gcd_union Finset.gcd_union
theorem gcd_congr {f g : β → α} (hs : s₁ = s₂) (hfg : ∀ a ∈ s₂, f a = g a) :
s₁.gcd f = s₂.gcd g := by
subst hs
exact Finset.fold_congr hfg
#align finset.gcd_congr Finset.gcd_congr
theorem gcd_mono_fun {g : β → α} (h : ∀ b ∈ s, f b ∣ g b) : s.gcd f ∣ s.gcd g :=
dvd_gcd fun b hb ↦ (gcd_dvd hb).trans (h b hb)
#align finset.gcd_mono_fun Finset.gcd_mono_fun
theorem gcd_mono (h : s₁ ⊆ s₂) : s₂.gcd f ∣ s₁.gcd f :=
dvd_gcd fun _ hb ↦ gcd_dvd (h hb)
#align finset.gcd_mono Finset.gcd_mono
| Mathlib/Algebra/GCDMonoid/Finset.lean | 203 | 205 | theorem gcd_image [DecidableEq β] {g : γ → β} (s : Finset γ) :
(s.image g).gcd f = s.gcd (f ∘ g) := by |
classical induction' s using Finset.induction with c s _ ih <;> simp [*]
|
import Mathlib.Analysis.Calculus.MeanValue
import Mathlib.Analysis.NormedSpace.RCLike
import Mathlib.Order.Filter.Curry
#align_import analysis.calculus.uniform_limits_deriv from "leanprover-community/mathlib"@"3f655f5297b030a87d641ad4e825af8d9679eb0b"
open Filter
open scoped uniformity Filter Topology
section LimitsOfDerivatives
variable {ι : Type*} {l : Filter ι} {E : Type*} [NormedAddCommGroup E] {𝕜 : Type*} [RCLike 𝕜]
[NormedSpace 𝕜 E] {G : Type*} [NormedAddCommGroup G] [NormedSpace 𝕜 G] {f : ι → E → G}
{g : E → G} {f' : ι → E → E →L[𝕜] G} {g' : E → E →L[𝕜] G} {x : E}
| Mathlib/Analysis/Calculus/UniformLimitsDeriv.lean | 112 | 163 | theorem uniformCauchySeqOnFilter_of_fderiv (hf' : UniformCauchySeqOnFilter f' l (𝓝 x))
(hf : ∀ᶠ n : ι × E in l ×ˢ 𝓝 x, HasFDerivAt (f n.1) (f' n.1 n.2) n.2)
(hfg : Cauchy (map (fun n => f n x) l)) : UniformCauchySeqOnFilter f l (𝓝 x) := by |
letI : NormedSpace ℝ E := NormedSpace.restrictScalars ℝ 𝕜 _
rw [SeminormedAddGroup.uniformCauchySeqOnFilter_iff_tendstoUniformlyOnFilter_zero] at hf' ⊢
suffices
TendstoUniformlyOnFilter (fun (n : ι × ι) (z : E) => f n.1 z - f n.2 z - (f n.1 x - f n.2 x)) 0
(l ×ˢ l) (𝓝 x) ∧
TendstoUniformlyOnFilter (fun (n : ι × ι) (_ : E) => f n.1 x - f n.2 x) 0 (l ×ˢ l) (𝓝 x) by
have := this.1.add this.2
rw [add_zero] at this
exact this.congr (by simp)
constructor
· -- This inequality follows from the mean value theorem. To apply it, we will need to shrink our
-- neighborhood to small enough ball
rw [Metric.tendstoUniformlyOnFilter_iff] at hf' ⊢
intro ε hε
have := (tendsto_swap4_prod.eventually (hf.prod_mk hf)).diag_of_prod_right
obtain ⟨a, b, c, d, e⟩ := eventually_prod_iff.1 ((hf' ε hε).and this)
obtain ⟨R, hR, hR'⟩ := Metric.nhds_basis_ball.eventually_iff.mp d
let r := min 1 R
have hr : 0 < r := by simp [r, hR]
have hr' : ∀ ⦃y : E⦄, y ∈ Metric.ball x r → c y := fun y hy =>
hR' (lt_of_lt_of_le (Metric.mem_ball.mp hy) (min_le_right _ _))
have hxy : ∀ y : E, y ∈ Metric.ball x r → ‖y - x‖ < 1 := by
intro y hy
rw [Metric.mem_ball, dist_eq_norm] at hy
exact lt_of_lt_of_le hy (min_le_left _ _)
have hxyε : ∀ y : E, y ∈ Metric.ball x r → ε * ‖y - x‖ < ε := by
intro y hy
exact (mul_lt_iff_lt_one_right hε.lt).mpr (hxy y hy)
-- With a small ball in hand, apply the mean value theorem
refine
eventually_prod_iff.mpr
⟨_, b, fun e : E => Metric.ball x r e,
eventually_mem_set.mpr (Metric.nhds_basis_ball.mem_of_mem hr), fun {n} hn {y} hy => ?_⟩
simp only [Pi.zero_apply, dist_zero_left] at e ⊢
refine lt_of_le_of_lt ?_ (hxyε y hy)
exact
Convex.norm_image_sub_le_of_norm_hasFDerivWithin_le
(fun y hy => ((e hn (hr' hy)).2.1.sub (e hn (hr' hy)).2.2).hasFDerivWithinAt)
(fun y hy => (e hn (hr' hy)).1.le) (convex_ball x r) (Metric.mem_ball_self hr) hy
· -- This is just `hfg` run through `eventually_prod_iff`
refine Metric.tendstoUniformlyOnFilter_iff.mpr fun ε hε => ?_
obtain ⟨t, ht, ht'⟩ := (Metric.cauchy_iff.mp hfg).2 ε hε
exact
eventually_prod_iff.mpr
⟨fun n : ι × ι => f n.1 x ∈ t ∧ f n.2 x ∈ t,
eventually_prod_iff.mpr ⟨_, ht, _, ht, fun {n} hn {n'} hn' => ⟨hn, hn'⟩⟩,
fun _ => True,
by simp,
fun {n} hn {y} _ => by simpa [norm_sub_rev, dist_eq_norm] using ht' _ hn.1 _ hn.2⟩
|
import Mathlib.SetTheory.Cardinal.Basic
import Mathlib.Tactic.Ring
#align_import data.nat.count from "leanprover-community/mathlib"@"dc6c365e751e34d100e80fe6e314c3c3e0fd2988"
open Finset
namespace Nat
variable (p : ℕ → Prop)
section Count
variable [DecidablePred p]
def count (n : ℕ) : ℕ :=
(List.range n).countP p
#align nat.count Nat.count
@[simp]
theorem count_zero : count p 0 = 0 := by
rw [count, List.range_zero, List.countP, List.countP.go]
#align nat.count_zero Nat.count_zero
def CountSet.fintype (n : ℕ) : Fintype { i // i < n ∧ p i } := by
apply Fintype.ofFinset ((Finset.range n).filter p)
intro x
rw [mem_filter, mem_range]
rfl
#align nat.count_set.fintype Nat.CountSet.fintype
scoped[Count] attribute [instance] Nat.CountSet.fintype
open Count
theorem count_eq_card_filter_range (n : ℕ) : count p n = ((range n).filter p).card := by
rw [count, List.countP_eq_length_filter]
rfl
#align nat.count_eq_card_filter_range Nat.count_eq_card_filter_range
theorem count_eq_card_fintype (n : ℕ) : count p n = Fintype.card { k : ℕ // k < n ∧ p k } := by
rw [count_eq_card_filter_range, ← Fintype.card_ofFinset, ← CountSet.fintype]
rfl
#align nat.count_eq_card_fintype Nat.count_eq_card_fintype
theorem count_succ (n : ℕ) : count p (n + 1) = count p n + if p n then 1 else 0 := by
split_ifs with h <;> simp [count, List.range_succ, h]
#align nat.count_succ Nat.count_succ
@[mono]
theorem count_monotone : Monotone (count p) :=
monotone_nat_of_le_succ fun n ↦ by by_cases h : p n <;> simp [count_succ, h]
#align nat.count_monotone Nat.count_monotone
theorem count_add (a b : ℕ) : count p (a + b) = count p a + count (fun k ↦ p (a + k)) b := by
have : Disjoint ((range a).filter p) (((range b).map <| addLeftEmbedding a).filter p) := by
apply disjoint_filter_filter
rw [Finset.disjoint_left]
simp_rw [mem_map, mem_range, addLeftEmbedding_apply]
rintro x hx ⟨c, _, rfl⟩
exact (self_le_add_right _ _).not_lt hx
simp_rw [count_eq_card_filter_range, range_add, filter_union, card_union_of_disjoint this,
filter_map, addLeftEmbedding, card_map]
rfl
#align nat.count_add Nat.count_add
theorem count_add' (a b : ℕ) : count p (a + b) = count (fun k ↦ p (k + b)) a + count p b := by
rw [add_comm, count_add, add_comm]
simp_rw [add_comm b]
#align nat.count_add' Nat.count_add'
theorem count_one : count p 1 = if p 0 then 1 else 0 := by simp [count_succ]
#align nat.count_one Nat.count_one
theorem count_succ' (n : ℕ) :
count p (n + 1) = count (fun k ↦ p (k + 1)) n + if p 0 then 1 else 0 := by
rw [count_add', count_one]
#align nat.count_succ' Nat.count_succ'
variable {p}
@[simp]
theorem count_lt_count_succ_iff {n : ℕ} : count p n < count p (n + 1) ↔ p n := by
by_cases h : p n <;> simp [count_succ, h]
#align nat.count_lt_count_succ_iff Nat.count_lt_count_succ_iff
theorem count_succ_eq_succ_count_iff {n : ℕ} : count p (n + 1) = count p n + 1 ↔ p n := by
by_cases h : p n <;> simp [h, count_succ]
#align nat.count_succ_eq_succ_count_iff Nat.count_succ_eq_succ_count_iff
theorem count_succ_eq_count_iff {n : ℕ} : count p (n + 1) = count p n ↔ ¬p n := by
by_cases h : p n <;> simp [h, count_succ]
#align nat.count_succ_eq_count_iff Nat.count_succ_eq_count_iff
alias ⟨_, count_succ_eq_succ_count⟩ := count_succ_eq_succ_count_iff
#align nat.count_succ_eq_succ_count Nat.count_succ_eq_succ_count
alias ⟨_, count_succ_eq_count⟩ := count_succ_eq_count_iff
#align nat.count_succ_eq_count Nat.count_succ_eq_count
| Mathlib/Data/Nat/Count.lean | 120 | 122 | theorem count_le_cardinal (n : ℕ) : (count p n : Cardinal) ≤ Cardinal.mk { k | p k } := by |
rw [count_eq_card_fintype, ← Cardinal.mk_fintype]
exact Cardinal.mk_subtype_mono fun x hx ↦ hx.2
|
import Mathlib.Data.Int.Order.Units
import Mathlib.Data.ZMod.IntUnitsPower
import Mathlib.RingTheory.TensorProduct.Basic
import Mathlib.LinearAlgebra.DirectSum.TensorProduct
import Mathlib.Algebra.DirectSum.Algebra
suppress_compilation
open scoped TensorProduct DirectSum
variable {R ι A B : Type*}
namespace TensorProduct
variable [CommSemiring ι] [Module ι (Additive ℤˣ)] [DecidableEq ι]
variable (𝒜 : ι → Type*) (ℬ : ι → Type*)
variable [CommRing R]
variable [∀ i, AddCommGroup (𝒜 i)] [∀ i, AddCommGroup (ℬ i)]
variable [∀ i, Module R (𝒜 i)] [∀ i, Module R (ℬ i)]
variable [DirectSum.GRing 𝒜] [DirectSum.GRing ℬ]
variable [DirectSum.GAlgebra R 𝒜] [DirectSum.GAlgebra R ℬ]
-- this helps with performance
instance (i : ι × ι) : Module R (𝒜 (Prod.fst i) ⊗[R] ℬ (Prod.snd i)) :=
TensorProduct.leftModule
open DirectSum (lof)
variable (R)
section gradedComm
local notation "𝒜ℬ" => (fun i : ι × ι => 𝒜 (Prod.fst i) ⊗[R] ℬ (Prod.snd i))
local notation "ℬ𝒜" => (fun i : ι × ι => ℬ (Prod.fst i) ⊗[R] 𝒜 (Prod.snd i))
def gradedCommAux : DirectSum _ 𝒜ℬ →ₗ[R] DirectSum _ ℬ𝒜 := by
refine DirectSum.toModule R _ _ fun i => ?_
have o := DirectSum.lof R _ ℬ𝒜 i.swap
have s : ℤˣ := ((-1 : ℤˣ)^(i.1* i.2 : ι) : ℤˣ)
exact (s • o) ∘ₗ (TensorProduct.comm R _ _).toLinearMap
@[simp]
theorem gradedCommAux_lof_tmul (i j : ι) (a : 𝒜 i) (b : ℬ j) :
gradedCommAux R 𝒜 ℬ (lof R _ 𝒜ℬ (i, j) (a ⊗ₜ b)) =
(-1 : ℤˣ)^(j * i) • lof R _ ℬ𝒜 (j, i) (b ⊗ₜ a) := by
rw [gradedCommAux]
dsimp
simp [mul_comm i j]
@[simp]
| Mathlib/LinearAlgebra/TensorProduct/Graded/External.lean | 93 | 98 | theorem gradedCommAux_comp_gradedCommAux :
gradedCommAux R 𝒜 ℬ ∘ₗ gradedCommAux R ℬ 𝒜 = LinearMap.id := by |
ext i a b
dsimp
rw [gradedCommAux_lof_tmul, LinearMap.map_smul_of_tower, gradedCommAux_lof_tmul, smul_smul,
mul_comm i.2 i.1, Int.units_mul_self, one_smul]
|
import Mathlib.Algebra.Group.Aut
import Mathlib.Algebra.Group.Invertible.Basic
import Mathlib.Algebra.GroupWithZero.Units.Basic
import Mathlib.GroupTheory.GroupAction.Units
#align_import group_theory.group_action.group from "leanprover-community/mathlib"@"3b52265189f3fb43aa631edffce5d060fafaf82f"
universe u v w
variable {α : Type u} {β : Type v} {γ : Type w}
section MulAction
section Group
variable [Group α] [MulAction α β]
@[to_additive (attr := simp)]
| Mathlib/GroupTheory/GroupAction/Group.lean | 30 | 30 | theorem inv_smul_smul (c : α) (x : β) : c⁻¹ • c • x = x := by | rw [smul_smul, mul_left_inv, one_smul]
|
import Mathlib.Dynamics.FixedPoints.Basic
import Mathlib.GroupTheory.Perm.Option
import Mathlib.Logic.Equiv.Defs
import Mathlib.Logic.Equiv.Option
#align_import combinatorics.derangements.basic from "leanprover-community/mathlib"@"9407b03373c8cd201df99d6bc5514fc2db44054f"
open Equiv Function
def derangements (α : Type*) : Set (Perm α) :=
{ f : Perm α | ∀ x : α, f x ≠ x }
#align derangements derangements
variable {α β : Type*}
theorem mem_derangements_iff_fixedPoints_eq_empty {f : Perm α} :
f ∈ derangements α ↔ fixedPoints f = ∅ :=
Set.eq_empty_iff_forall_not_mem.symm
#align mem_derangements_iff_fixed_points_eq_empty mem_derangements_iff_fixedPoints_eq_empty
def Equiv.derangementsCongr (e : α ≃ β) : derangements α ≃ derangements β :=
e.permCongr.subtypeEquiv fun {f} => e.forall_congr <| by
intro b; simp only [ne_eq, permCongr_apply, symm_apply_apply, EmbeddingLike.apply_eq_iff_eq]
#align equiv.derangements_congr Equiv.derangementsCongr
namespace derangements
protected def subtypeEquiv (p : α → Prop) [DecidablePred p] :
derangements (Subtype p) ≃ { f : Perm α // ∀ a, ¬p a ↔ a ∈ fixedPoints f } :=
calc
derangements (Subtype p) ≃ { f : { f : Perm α // ∀ a, ¬p a → a ∈ fixedPoints f } //
∀ a, a ∈ fixedPoints f → ¬p a } := by
refine (Perm.subtypeEquivSubtypePerm p).subtypeEquiv fun f => ⟨fun hf a hfa ha => ?_, ?_⟩
· refine hf ⟨a, ha⟩ (Subtype.ext ?_)
simp_rw [mem_fixedPoints, IsFixedPt, Perm.subtypeEquivSubtypePerm,
Equiv.coe_fn_mk, Perm.ofSubtype_apply_of_mem _ ha] at hfa
assumption
rintro hf ⟨a, ha⟩ hfa
refine hf _ ?_ ha
simp only [Perm.subtypeEquivSubtypePerm_apply_coe, mem_fixedPoints]
dsimp [IsFixedPt]
simp_rw [Perm.ofSubtype_apply_of_mem _ ha, hfa]
_ ≃ { f : Perm α // ∃ _h : ∀ a, ¬p a → a ∈ fixedPoints f, ∀ a, a ∈ fixedPoints f → ¬p a } :=
subtypeSubtypeEquivSubtypeExists _ _
_ ≃ { f : Perm α // ∀ a, ¬p a ↔ a ∈ fixedPoints f } :=
subtypeEquivRight fun f => by
simp_rw [exists_prop, ← forall_and, ← iff_iff_implies_and_implies]
#align derangements.subtype_equiv derangements.subtypeEquiv
universe u
def atMostOneFixedPointEquivSum_derangements [DecidableEq α] (a : α) :
{ f : Perm α // fixedPoints f ⊆ {a} } ≃ Sum (derangements ({a}ᶜ : Set α)) (derangements α) :=
calc
{ f : Perm α // fixedPoints f ⊆ {a} } ≃
Sum { f : { f : Perm α // fixedPoints f ⊆ {a} } // a ∈ fixedPoints f }
{ f : { f : Perm α // fixedPoints f ⊆ {a} } // a ∉ fixedPoints f } :=
(Equiv.sumCompl _).symm
_ ≃ Sum { f : Perm α // fixedPoints f ⊆ {a} ∧ a ∈ fixedPoints f }
{ f : Perm α // fixedPoints f ⊆ {a} ∧ a ∉ fixedPoints f } := by
-- Porting note: `subtypeSubtypeEquivSubtypeInter` no longer works with placeholder `_`s.
refine Equiv.sumCongr ?_ ?_
· exact subtypeSubtypeEquivSubtypeInter
(fun x : Perm α => fixedPoints x ⊆ {a})
(a ∈ fixedPoints ·)
· exact subtypeSubtypeEquivSubtypeInter
(fun x : Perm α => fixedPoints x ⊆ {a})
(¬a ∈ fixedPoints ·)
_ ≃ Sum { f : Perm α // fixedPoints f = {a} } { f : Perm α // fixedPoints f = ∅ } := by
refine Equiv.sumCongr (subtypeEquivRight fun f => ?_) (subtypeEquivRight fun f => ?_)
· rw [Set.eq_singleton_iff_unique_mem, and_comm]
rfl
· rw [Set.eq_empty_iff_forall_not_mem]
exact ⟨fun h x hx => h.2 (h.1 hx ▸ hx), fun h => ⟨fun x hx => (h _ hx).elim, h _⟩⟩
_ ≃ Sum (derangements ({a}ᶜ : Set α)) (derangements α) := by
-- Porting note: was `subtypeEquiv _` but now needs the placeholder to be provided explicitly
refine
Equiv.sumCongr ((derangements.subtypeEquiv (· ∈ ({a}ᶜ : Set α))).trans <|
subtypeEquivRight fun x => ?_).symm
(subtypeEquivRight fun f => mem_derangements_iff_fixedPoints_eq_empty.symm)
rw [eq_comm, Set.ext_iff]
simp_rw [Set.mem_compl_iff, Classical.not_not]
#align derangements.at_most_one_fixed_point_equiv_sum_derangements derangements.atMostOneFixedPointEquivSum_derangements
namespace Equiv
variable [DecidableEq α]
def RemoveNone.fiber (a : Option α) : Set (Perm α) :=
{ f : Perm α | (a, f) ∈ Equiv.Perm.decomposeOption '' derangements (Option α) }
#align derangements.equiv.remove_none.fiber derangements.Equiv.RemoveNone.fiber
theorem RemoveNone.mem_fiber (a : Option α) (f : Perm α) :
f ∈ RemoveNone.fiber a ↔
∃ F : Perm (Option α), F ∈ derangements (Option α) ∧ F none = a ∧ removeNone F = f := by
simp [RemoveNone.fiber, derangements]
#align derangements.equiv.remove_none.mem_fiber derangements.Equiv.RemoveNone.mem_fiber
| Mathlib/Combinatorics/Derangements/Basic.lean | 129 | 134 | theorem RemoveNone.fiber_none : RemoveNone.fiber (@none α) = ∅ := by |
rw [Set.eq_empty_iff_forall_not_mem]
intro f hyp
rw [RemoveNone.mem_fiber] at hyp
rcases hyp with ⟨F, F_derangement, F_none, _⟩
exact F_derangement none F_none
|
import Mathlib.Geometry.Euclidean.Inversion.Basic
import Mathlib.Geometry.Euclidean.PerpBisector
open Metric Function AffineMap Set AffineSubspace
open scoped Topology
variable {V P : Type*} [NormedAddCommGroup V] [InnerProductSpace ℝ V] [MetricSpace P]
[NormedAddTorsor V P] {c x y : P} {R : ℝ}
namespace EuclideanGeometry
theorem inversion_mem_perpBisector_inversion_iff (hR : R ≠ 0) (hx : x ≠ c) (hy : y ≠ c) :
inversion c R x ∈ perpBisector c (inversion c R y) ↔ dist x y = dist y c := by
rw [mem_perpBisector_iff_dist_eq, dist_inversion_inversion hx hy, dist_inversion_center]
have hx' := dist_ne_zero.2 hx
have hy' := dist_ne_zero.2 hy
field_simp [mul_assoc, mul_comm, hx, hx.symm, eq_comm]
theorem inversion_mem_perpBisector_inversion_iff' (hR : R ≠ 0) (hy : y ≠ c) :
inversion c R x ∈ perpBisector c (inversion c R y) ↔ dist x y = dist y c ∧ x ≠ c := by
rcases eq_or_ne x c with rfl | hx
· simp [*]
· simp [inversion_mem_perpBisector_inversion_iff hR hx hy, hx]
theorem preimage_inversion_perpBisector_inversion (hR : R ≠ 0) (hy : y ≠ c) :
inversion c R ⁻¹' perpBisector c (inversion c R y) = sphere y (dist y c) \ {c} :=
Set.ext fun _ ↦ inversion_mem_perpBisector_inversion_iff' hR hy
theorem preimage_inversion_perpBisector (hR : R ≠ 0) (hy : y ≠ c) :
inversion c R ⁻¹' perpBisector c y = sphere (inversion c R y) (R ^ 2 / dist y c) \ {c} := by
rw [← dist_inversion_center, ← preimage_inversion_perpBisector_inversion hR,
inversion_inversion] <;> simp [*]
| Mathlib/Geometry/Euclidean/Inversion/ImageHyperplane.lean | 61 | 64 | theorem image_inversion_perpBisector (hR : R ≠ 0) (hy : y ≠ c) :
inversion c R '' perpBisector c y = sphere (inversion c R y) (R ^ 2 / dist y c) \ {c} := by |
rw [image_eq_preimage_of_inverse (inversion_involutive _ hR) (inversion_involutive _ hR),
preimage_inversion_perpBisector hR hy]
|
import Mathlib.Order.Filter.Prod
#align_import order.filter.n_ary from "leanprover-community/mathlib"@"78f647f8517f021d839a7553d5dc97e79b508dea"
open Function Set
open Filter
namespace Filter
variable {α α' β β' γ γ' δ δ' ε ε' : Type*} {m : α → β → γ} {f f₁ f₂ : Filter α}
{g g₁ g₂ : Filter β} {h h₁ h₂ : Filter γ} {s s₁ s₂ : Set α} {t t₁ t₂ : Set β} {u : Set γ}
{v : Set δ} {a : α} {b : β} {c : γ}
def map₂ (m : α → β → γ) (f : Filter α) (g : Filter β) : Filter γ :=
((f ×ˢ g).map (uncurry m)).copy { s | ∃ u ∈ f, ∃ v ∈ g, image2 m u v ⊆ s } fun _ ↦ by
simp only [mem_map, mem_prod_iff, image2_subset_iff, prod_subset_iff]; rfl
#align filter.map₂ Filter.map₂
@[simp 900]
theorem mem_map₂_iff : u ∈ map₂ m f g ↔ ∃ s ∈ f, ∃ t ∈ g, image2 m s t ⊆ u :=
Iff.rfl
#align filter.mem_map₂_iff Filter.mem_map₂_iff
theorem image2_mem_map₂ (hs : s ∈ f) (ht : t ∈ g) : image2 m s t ∈ map₂ m f g :=
⟨_, hs, _, ht, Subset.rfl⟩
#align filter.image2_mem_map₂ Filter.image2_mem_map₂
theorem map_prod_eq_map₂ (m : α → β → γ) (f : Filter α) (g : Filter β) :
Filter.map (fun p : α × β => m p.1 p.2) (f ×ˢ g) = map₂ m f g := by
rw [map₂, copy_eq, uncurry_def]
#align filter.map_prod_eq_map₂ Filter.map_prod_eq_map₂
theorem map_prod_eq_map₂' (m : α × β → γ) (f : Filter α) (g : Filter β) :
Filter.map m (f ×ˢ g) = map₂ (fun a b => m (a, b)) f g :=
map_prod_eq_map₂ (curry m) f g
#align filter.map_prod_eq_map₂' Filter.map_prod_eq_map₂'
@[simp]
theorem map₂_mk_eq_prod (f : Filter α) (g : Filter β) : map₂ Prod.mk f g = f ×ˢ g := by
simp only [← map_prod_eq_map₂, map_id']
#align filter.map₂_mk_eq_prod Filter.map₂_mk_eq_prod
-- lemma image2_mem_map₂_iff (hm : injective2 m) : image2 m s t ∈ map₂ m f g ↔ s ∈ f ∧ t ∈ g :=
-- ⟨by { rintro ⟨u, v, hu, hv, h⟩, rw image2_subset_image2_iff hm at h,
-- exact ⟨mem_of_superset hu h.1, mem_of_superset hv h.2⟩ }, λ h, image2_mem_map₂ h.1 h.2⟩
theorem map₂_mono (hf : f₁ ≤ f₂) (hg : g₁ ≤ g₂) : map₂ m f₁ g₁ ≤ map₂ m f₂ g₂ :=
fun _ ⟨s, hs, t, ht, hst⟩ => ⟨s, hf hs, t, hg ht, hst⟩
#align filter.map₂_mono Filter.map₂_mono
theorem map₂_mono_left (h : g₁ ≤ g₂) : map₂ m f g₁ ≤ map₂ m f g₂ :=
map₂_mono Subset.rfl h
#align filter.map₂_mono_left Filter.map₂_mono_left
theorem map₂_mono_right (h : f₁ ≤ f₂) : map₂ m f₁ g ≤ map₂ m f₂ g :=
map₂_mono h Subset.rfl
#align filter.map₂_mono_right Filter.map₂_mono_right
@[simp]
theorem le_map₂_iff {h : Filter γ} :
h ≤ map₂ m f g ↔ ∀ ⦃s⦄, s ∈ f → ∀ ⦃t⦄, t ∈ g → image2 m s t ∈ h :=
⟨fun H _ hs _ ht => H <| image2_mem_map₂ hs ht, fun H _ ⟨_, hs, _, ht, hu⟩ =>
mem_of_superset (H hs ht) hu⟩
#align filter.le_map₂_iff Filter.le_map₂_iff
@[simp]
theorem map₂_eq_bot_iff : map₂ m f g = ⊥ ↔ f = ⊥ ∨ g = ⊥ := by simp [← map_prod_eq_map₂]
#align filter.map₂_eq_bot_iff Filter.map₂_eq_bot_iff
@[simp]
theorem map₂_bot_left : map₂ m ⊥ g = ⊥ := map₂_eq_bot_iff.2 <| .inl rfl
#align filter.map₂_bot_left Filter.map₂_bot_left
@[simp]
theorem map₂_bot_right : map₂ m f ⊥ = ⊥ := map₂_eq_bot_iff.2 <| .inr rfl
#align filter.map₂_bot_right Filter.map₂_bot_right
@[simp]
| Mathlib/Order/Filter/NAry.lean | 103 | 103 | theorem map₂_neBot_iff : (map₂ m f g).NeBot ↔ f.NeBot ∧ g.NeBot := by | simp [neBot_iff, not_or]
|
import Mathlib.Data.ZMod.Quotient
import Mathlib.GroupTheory.NoncommPiCoprod
import Mathlib.GroupTheory.OrderOfElement
import Mathlib.Algebra.GCDMonoid.Finset
import Mathlib.Algebra.GCDMonoid.Nat
import Mathlib.Data.Nat.Factorization.Basic
import Mathlib.Tactic.ByContra
import Mathlib.Tactic.Peel
#align_import group_theory.exponent from "leanprover-community/mathlib"@"52fa514ec337dd970d71d8de8d0fd68b455a1e54"
universe u
variable {G : Type u}
open scoped Classical
namespace Monoid
section Monoid
variable (G) [Monoid G]
@[to_additive
"A predicate on an additive monoid saying that there is a positive integer `n` such\n
that `n • g = 0` for all `g`."]
def ExponentExists :=
∃ n, 0 < n ∧ ∀ g : G, g ^ n = 1
#align monoid.exponent_exists Monoid.ExponentExists
#align add_monoid.exponent_exists AddMonoid.ExponentExists
@[to_additive
"The exponent of an additive group is the smallest positive integer `n` such that\n
`n • g = 0` for all `g ∈ G` if it exists, otherwise it is zero by convention."]
noncomputable def exponent :=
if h : ExponentExists G then Nat.find h else 0
#align monoid.exponent Monoid.exponent
#align add_monoid.exponent AddMonoid.exponent
variable {G}
@[simp]
theorem _root_.AddMonoid.exponent_additive :
AddMonoid.exponent (Additive G) = exponent G := rfl
@[simp]
theorem exponent_multiplicative {G : Type*} [AddMonoid G] :
exponent (Multiplicative G) = AddMonoid.exponent G := rfl
open MulOpposite in
@[to_additive (attr := simp)]
theorem _root_.MulOpposite.exponent : exponent (MulOpposite G) = exponent G := by
simp only [Monoid.exponent, ExponentExists]
congr!
all_goals exact ⟨(op_injective <| · <| op ·), (unop_injective <| · <| unop ·)⟩
@[to_additive]
theorem ExponentExists.isOfFinOrder (h : ExponentExists G) {g : G} : IsOfFinOrder g :=
isOfFinOrder_iff_pow_eq_one.mpr <| by peel 2 h; exact this g
@[to_additive]
theorem ExponentExists.orderOf_pos (h : ExponentExists G) (g : G) : 0 < orderOf g :=
h.isOfFinOrder.orderOf_pos
@[to_additive]
theorem exponent_ne_zero : exponent G ≠ 0 ↔ ExponentExists G := by
rw [exponent]
split_ifs with h
· simp [h, @not_lt_zero' ℕ]
--if this isn't done this way, `to_additive` freaks
· tauto
#align monoid.exponent_exists_iff_ne_zero Monoid.exponent_ne_zero
#align add_monoid.exponent_exists_iff_ne_zero AddMonoid.exponent_ne_zero
@[to_additive]
protected alias ⟨_, ExponentExists.exponent_ne_zero⟩ := exponent_ne_zero
@[to_additive (attr := deprecated (since := "2024-01-27"))]
theorem exponentExists_iff_ne_zero : ExponentExists G ↔ exponent G ≠ 0 := exponent_ne_zero.symm
@[to_additive]
theorem exponent_pos : 0 < exponent G ↔ ExponentExists G :=
pos_iff_ne_zero.trans exponent_ne_zero
@[to_additive]
protected alias ⟨_, ExponentExists.exponent_pos⟩ := exponent_pos
@[to_additive]
theorem exponent_eq_zero_iff : exponent G = 0 ↔ ¬ExponentExists G :=
exponent_ne_zero.not_right
#align monoid.exponent_eq_zero_iff Monoid.exponent_eq_zero_iff
#align add_monoid.exponent_eq_zero_iff AddMonoid.exponent_eq_zero_iff
@[to_additive exponent_eq_zero_addOrder_zero]
theorem exponent_eq_zero_of_order_zero {g : G} (hg : orderOf g = 0) : exponent G = 0 :=
exponent_eq_zero_iff.mpr fun h ↦ h.orderOf_pos g |>.ne' hg
#align monoid.exponent_eq_zero_of_order_zero Monoid.exponent_eq_zero_of_order_zero
#align add_monoid.exponent_eq_zero_of_order_zero AddMonoid.exponent_eq_zero_addOrder_zero
@[to_additive "The exponent is zero iff for all nonzero `n`, one can find a `g` such that
`n • g ≠ 0`."]
theorem exponent_eq_zero_iff_forall : exponent G = 0 ↔ ∀ n > 0, ∃ g : G, g ^ n ≠ 1 := by
rw [exponent_eq_zero_iff, ExponentExists]
push_neg
rfl
@[to_additive exponent_nsmul_eq_zero]
theorem pow_exponent_eq_one (g : G) : g ^ exponent G = 1 := by
by_cases h : ExponentExists G
· simp_rw [exponent, dif_pos h]
exact (Nat.find_spec h).2 g
· simp_rw [exponent, dif_neg h, pow_zero]
#align monoid.pow_exponent_eq_one Monoid.pow_exponent_eq_one
#align add_monoid.exponent_nsmul_eq_zero AddMonoid.exponent_nsmul_eq_zero
@[to_additive]
| Mathlib/GroupTheory/Exponent.lean | 160 | 163 | theorem pow_eq_mod_exponent {n : ℕ} (g : G) : g ^ n = g ^ (n % exponent G) :=
calc
g ^ n = g ^ (n % exponent G + exponent G * (n / exponent G)) := by | rw [Nat.mod_add_div]
_ = g ^ (n % exponent G) := by simp [pow_add, pow_mul, pow_exponent_eq_one]
|
import Mathlib.RingTheory.RootsOfUnity.Basic
universe u
variable {L : Type u} [CommRing L] [IsDomain L]
variable (n : ℕ+)
theorem rootsOfUnity.integer_power_of_ringEquiv (g : L ≃+* L) :
∃ m : ℤ, ∀ t : rootsOfUnity n L, g (t : Lˣ) = (t ^ m : Lˣ) := by
obtain ⟨m, hm⟩ := MonoidHom.map_cyclic ((g : L ≃* L).restrictRootsOfUnity n).toMonoidHom
exact ⟨m, fun t ↦ Units.ext_iff.1 <| SetCoe.ext_iff.2 <| hm t⟩
| Mathlib/NumberTheory/Cyclotomic/CyclotomicCharacter.lean | 77 | 79 | theorem rootsOfUnity.integer_power_of_ringEquiv' (g : L ≃+* L) :
∃ m : ℤ, ∀ t ∈ rootsOfUnity n L, g (t : Lˣ) = (t ^ m : Lˣ) := by |
simpa using rootsOfUnity.integer_power_of_ringEquiv n g
|
import Mathlib.Order.Interval.Set.UnorderedInterval
import Mathlib.Algebra.Order.Interval.Set.Monoid
import Mathlib.Data.Set.Pointwise.Basic
import Mathlib.Algebra.Order.Field.Basic
import Mathlib.Algebra.Order.Group.MinMax
#align_import data.set.pointwise.interval from "leanprover-community/mathlib"@"2196ab363eb097c008d4497125e0dde23fb36db2"
open Interval Pointwise
variable {α : Type*}
namespace Set
section ContravariantLT
variable [Mul α] [PartialOrder α]
variable [CovariantClass α α (· * ·) (· < ·)] [CovariantClass α α (Function.swap HMul.hMul) LT.lt]
@[to_additive Icc_add_Ico_subset]
theorem Icc_mul_Ico_subset' (a b c d : α) : Icc a b * Ico c d ⊆ Ico (a * c) (b * d) := by
haveI := covariantClass_le_of_lt
rintro x ⟨y, ⟨hya, hyb⟩, z, ⟨hzc, hzd⟩, rfl⟩
exact ⟨mul_le_mul' hya hzc, mul_lt_mul_of_le_of_lt hyb hzd⟩
@[to_additive Ico_add_Icc_subset]
theorem Ico_mul_Icc_subset' (a b c d : α) : Ico a b * Icc c d ⊆ Ico (a * c) (b * d) := by
haveI := covariantClass_le_of_lt
rintro x ⟨y, ⟨hya, hyb⟩, z, ⟨hzc, hzd⟩, rfl⟩
exact ⟨mul_le_mul' hya hzc, mul_lt_mul_of_lt_of_le hyb hzd⟩
@[to_additive Ioc_add_Ico_subset]
theorem Ioc_mul_Ico_subset' (a b c d : α) : Ioc a b * Ico c d ⊆ Ioo (a * c) (b * d) := by
haveI := covariantClass_le_of_lt
rintro x ⟨y, ⟨hya, hyb⟩, z, ⟨hzc, hzd⟩, rfl⟩
exact ⟨mul_lt_mul_of_lt_of_le hya hzc, mul_lt_mul_of_le_of_lt hyb hzd⟩
@[to_additive Ico_add_Ioc_subset]
theorem Ico_mul_Ioc_subset' (a b c d : α) : Ico a b * Ioc c d ⊆ Ioo (a * c) (b * d) := by
haveI := covariantClass_le_of_lt
rintro x ⟨y, ⟨hya, hyb⟩, z, ⟨hzc, hzd⟩, rfl⟩
exact ⟨mul_lt_mul_of_le_of_lt hya hzc, mul_lt_mul_of_lt_of_le hyb hzd⟩
@[to_additive Iic_add_Iio_subset]
theorem Iic_mul_Iio_subset' (a b : α) : Iic a * Iio b ⊆ Iio (a * b) := by
haveI := covariantClass_le_of_lt
rintro x ⟨y, hya, z, hzb, rfl⟩
exact mul_lt_mul_of_le_of_lt hya hzb
@[to_additive Iio_add_Iic_subset]
| Mathlib/Data/Set/Pointwise/Interval.lean | 98 | 101 | theorem Iio_mul_Iic_subset' (a b : α) : Iio a * Iic b ⊆ Iio (a * b) := by |
haveI := covariantClass_le_of_lt
rintro x ⟨y, hya, z, hzb, rfl⟩
exact mul_lt_mul_of_lt_of_le hya hzb
|
import Mathlib.Analysis.Calculus.BumpFunction.FiniteDimension
import Mathlib.Geometry.Manifold.ContMDiff.Atlas
import Mathlib.Geometry.Manifold.ContMDiff.NormedSpace
#align_import geometry.manifold.bump_function from "leanprover-community/mathlib"@"b018406ad2f2a73223a3a9e198ccae61e6f05318"
universe uE uF uH uM
variable {E : Type uE} [NormedAddCommGroup E] [NormedSpace ℝ E] [FiniteDimensional ℝ E]
{H : Type uH} [TopologicalSpace H] (I : ModelWithCorners ℝ E H) {M : Type uM} [TopologicalSpace M]
[ChartedSpace H M] [SmoothManifoldWithCorners I M]
open Function Filter FiniteDimensional Set Metric
open scoped Topology Manifold Classical Filter
noncomputable section
structure SmoothBumpFunction (c : M) extends ContDiffBump (extChartAt I c c) where
closedBall_subset : closedBall (extChartAt I c c) rOut ∩ range I ⊆ (extChartAt I c).target
#align smooth_bump_function SmoothBumpFunction
namespace SmoothBumpFunction
variable {c : M} (f : SmoothBumpFunction I c) {x : M} {I}
@[coe] def toFun : M → ℝ :=
indicator (chartAt H c).source (f.toContDiffBump ∘ extChartAt I c)
#align smooth_bump_function.to_fun SmoothBumpFunction.toFun
instance : CoeFun (SmoothBumpFunction I c) fun _ => M → ℝ :=
⟨toFun⟩
theorem coe_def : ⇑f = indicator (chartAt H c).source (f.toContDiffBump ∘ extChartAt I c) :=
rfl
#align smooth_bump_function.coe_def SmoothBumpFunction.coe_def
theorem rOut_pos : 0 < f.rOut :=
f.toContDiffBump.rOut_pos
set_option linter.uppercaseLean3 false in
#align smooth_bump_function.R_pos SmoothBumpFunction.rOut_pos
theorem ball_subset : ball (extChartAt I c c) f.rOut ∩ range I ⊆ (extChartAt I c).target :=
Subset.trans (inter_subset_inter_left _ ball_subset_closedBall) f.closedBall_subset
#align smooth_bump_function.ball_subset SmoothBumpFunction.ball_subset
theorem ball_inter_range_eq_ball_inter_target :
ball (extChartAt I c c) f.rOut ∩ range I =
ball (extChartAt I c c) f.rOut ∩ (extChartAt I c).target :=
(subset_inter inter_subset_left f.ball_subset).antisymm <| inter_subset_inter_right _ <|
extChartAt_target_subset_range _ _
theorem eqOn_source : EqOn f (f.toContDiffBump ∘ extChartAt I c) (chartAt H c).source :=
eqOn_indicator
#align smooth_bump_function.eq_on_source SmoothBumpFunction.eqOn_source
theorem eventuallyEq_of_mem_source (hx : x ∈ (chartAt H c).source) :
f =ᶠ[𝓝 x] f.toContDiffBump ∘ extChartAt I c :=
f.eqOn_source.eventuallyEq_of_mem <| (chartAt H c).open_source.mem_nhds hx
#align smooth_bump_function.eventually_eq_of_mem_source SmoothBumpFunction.eventuallyEq_of_mem_source
theorem one_of_dist_le (hs : x ∈ (chartAt H c).source)
(hd : dist (extChartAt I c x) (extChartAt I c c) ≤ f.rIn) : f x = 1 := by
simp only [f.eqOn_source hs, (· ∘ ·), f.one_of_mem_closedBall hd]
#align smooth_bump_function.one_of_dist_le SmoothBumpFunction.one_of_dist_le
| Mathlib/Geometry/Manifold/BumpFunction.lean | 112 | 116 | theorem support_eq_inter_preimage :
support f = (chartAt H c).source ∩ extChartAt I c ⁻¹' ball (extChartAt I c c) f.rOut := by |
rw [coe_def, support_indicator, support_comp_eq_preimage, ← extChartAt_source I,
← (extChartAt I c).symm_image_target_inter_eq', ← (extChartAt I c).symm_image_target_inter_eq',
f.support_eq]
|
import Mathlib.Data.Fintype.Card
import Mathlib.Computability.Language
import Mathlib.Tactic.NormNum
#align_import computability.DFA from "leanprover-community/mathlib"@"32253a1a1071173b33dc7d6a218cf722c6feb514"
open Computability
universe u v
-- Porting note: Required as `DFA` is used in mathlib3
set_option linter.uppercaseLean3 false
structure DFA (α : Type u) (σ : Type v) where
step : σ → α → σ
start : σ
accept : Set σ
#align DFA DFA
namespace DFA
variable {α : Type u} {σ : Type v} (M : DFA α σ)
instance [Inhabited σ] : Inhabited (DFA α σ) :=
⟨DFA.mk (fun _ _ => default) default ∅⟩
def evalFrom (start : σ) : List α → σ :=
List.foldl M.step start
#align DFA.eval_from DFA.evalFrom
@[simp]
theorem evalFrom_nil (s : σ) : M.evalFrom s [] = s :=
rfl
#align DFA.eval_from_nil DFA.evalFrom_nil
@[simp]
theorem evalFrom_singleton (s : σ) (a : α) : M.evalFrom s [a] = M.step s a :=
rfl
#align DFA.eval_from_singleton DFA.evalFrom_singleton
@[simp]
theorem evalFrom_append_singleton (s : σ) (x : List α) (a : α) :
M.evalFrom s (x ++ [a]) = M.step (M.evalFrom s x) a := by
simp only [evalFrom, List.foldl_append, List.foldl_cons, List.foldl_nil]
#align DFA.eval_from_append_singleton DFA.evalFrom_append_singleton
def eval : List α → σ :=
M.evalFrom M.start
#align DFA.eval DFA.eval
@[simp]
theorem eval_nil : M.eval [] = M.start :=
rfl
#align DFA.eval_nil DFA.eval_nil
@[simp]
theorem eval_singleton (a : α) : M.eval [a] = M.step M.start a :=
rfl
#align DFA.eval_singleton DFA.eval_singleton
@[simp]
theorem eval_append_singleton (x : List α) (a : α) : M.eval (x ++ [a]) = M.step (M.eval x) a :=
evalFrom_append_singleton _ _ _ _
#align DFA.eval_append_singleton DFA.eval_append_singleton
theorem evalFrom_of_append (start : σ) (x y : List α) :
M.evalFrom start (x ++ y) = M.evalFrom (M.evalFrom start x) y :=
x.foldl_append _ _ y
#align DFA.eval_from_of_append DFA.evalFrom_of_append
def accepts : Language α := {x | M.eval x ∈ M.accept}
#align DFA.accepts DFA.accepts
theorem mem_accepts (x : List α) : x ∈ M.accepts ↔ M.evalFrom M.start x ∈ M.accept := by rfl
#align DFA.mem_accepts DFA.mem_accepts
| Mathlib/Computability/DFA.lean | 101 | 134 | theorem evalFrom_split [Fintype σ] {x : List α} {s t : σ} (hlen : Fintype.card σ ≤ x.length)
(hx : M.evalFrom s x = t) :
∃ q a b c,
x = a ++ b ++ c ∧
a.length + b.length ≤ Fintype.card σ ∧
b ≠ [] ∧ M.evalFrom s a = q ∧ M.evalFrom q b = q ∧ M.evalFrom q c = t := by |
obtain ⟨n, m, hneq, heq⟩ :=
Fintype.exists_ne_map_eq_of_card_lt
(fun n : Fin (Fintype.card σ + 1) => M.evalFrom s (x.take n)) (by norm_num)
wlog hle : (n : ℕ) ≤ m
· exact this _ hlen hx _ _ hneq.symm heq.symm (le_of_not_le hle)
have hm : (m : ℕ) ≤ Fintype.card σ := Fin.is_le m
refine
⟨M.evalFrom s ((x.take m).take n), (x.take m).take n, (x.take m).drop n,
x.drop m, ?_, ?_, ?_, by rfl, ?_⟩
· rw [List.take_append_drop, List.take_append_drop]
· simp only [List.length_drop, List.length_take]
rw [min_eq_left (hm.trans hlen), min_eq_left hle, add_tsub_cancel_of_le hle]
exact hm
· intro h
have hlen' := congr_arg List.length h
simp only [List.length_drop, List.length, List.length_take] at hlen'
rw [min_eq_left, tsub_eq_zero_iff_le] at hlen'
· apply hneq
apply le_antisymm
assumption'
exact hm.trans hlen
have hq : M.evalFrom (M.evalFrom s ((x.take m).take n)) ((x.take m).drop n) =
M.evalFrom s ((x.take m).take n) := by
rw [List.take_take, min_eq_left hle, ← evalFrom_of_append, heq, ← min_eq_left hle, ←
List.take_take, min_eq_left hle, List.take_append_drop]
use hq
rwa [← hq, ← evalFrom_of_append, ← evalFrom_of_append, ← List.append_assoc,
List.take_append_drop, List.take_append_drop]
|
import Mathlib.CategoryTheory.Sites.Sheaf
#align_import category_theory.sites.canonical from "leanprover-community/mathlib"@"9e7c80f638149bfb3504ba8ff48dfdbfc949fb1a"
universe v u
namespace CategoryTheory
open scoped Classical
open CategoryTheory Category Limits Sieve
variable {C : Type u} [Category.{v} C]
namespace Sheaf
variable {P : Cᵒᵖ ⥤ Type v}
variable {X Y : C} {S : Sieve X} {R : Presieve X}
variable (J J₂ : GrothendieckTopology C)
| Mathlib/CategoryTheory/Sites/Canonical.lean | 61 | 113 | theorem isSheafFor_bind (P : Cᵒᵖ ⥤ Type v) (U : Sieve X) (B : ∀ ⦃Y⦄ ⦃f : Y ⟶ X⦄, U f → Sieve Y)
(hU : Presieve.IsSheafFor P (U : Presieve X))
(hB : ∀ ⦃Y⦄ ⦃f : Y ⟶ X⦄ (hf : U f), Presieve.IsSheafFor P (B hf : Presieve Y))
(hB' : ∀ ⦃Y⦄ ⦃f : Y ⟶ X⦄ (h : U f) ⦃Z⦄ (g : Z ⟶ Y),
Presieve.IsSeparatedFor P (((B h).pullback g) : Presieve Z)) :
Presieve.IsSheafFor P (Sieve.bind (U : Presieve X) B : Presieve X) := by |
intro s hs
let y : ∀ ⦃Y⦄ ⦃f : Y ⟶ X⦄ (hf : U f), Presieve.FamilyOfElements P (B hf : Presieve Y) :=
fun Y f hf Z g hg => s _ (Presieve.bind_comp _ _ hg)
have hy : ∀ ⦃Y⦄ ⦃f : Y ⟶ X⦄ (hf : U f), (y hf).Compatible := by
intro Y f H Y₁ Y₂ Z g₁ g₂ f₁ f₂ hf₁ hf₂ comm
apply hs
apply reassoc_of% comm
let t : Presieve.FamilyOfElements P (U : Presieve X) :=
fun Y f hf => (hB hf).amalgamate (y hf) (hy hf)
have ht : ∀ ⦃Y⦄ ⦃f : Y ⟶ X⦄ (hf : U f), (y hf).IsAmalgamation (t f hf) := fun Y f hf =>
(hB hf).isAmalgamation _
have hT : t.Compatible := by
rw [Presieve.compatible_iff_sieveCompatible]
intro Z W f h hf
apply (hB (U.downward_closed hf h)).isSeparatedFor.ext
intro Y l hl
apply (hB' hf (l ≫ h)).ext
intro M m hm
have : bind U B (m ≫ l ≫ h ≫ f) := by
-- Porting note: had to make explicit the parameter `((m ≫ l ≫ h) ≫ f)` and
-- using `by exact`
have : bind U B ((m ≫ l ≫ h) ≫ f) := by exact Presieve.bind_comp f hf hm
simpa using this
trans s (m ≫ l ≫ h ≫ f) this
· have := ht (U.downward_closed hf h) _ ((B _).downward_closed hl m)
rw [op_comp, FunctorToTypes.map_comp_apply] at this
rw [this]
change s _ _ = s _ _
-- Porting note: the proof was `by simp`
congr 1
simp only [assoc]
· have h : s _ _ = _ := (ht hf _ hm).symm
-- Porting note: this was done by `simp only [assoc] at`
conv_lhs at h => congr; rw [assoc, assoc]
rw [h]
simp only [op_comp, assoc, FunctorToTypes.map_comp_apply]
refine ⟨hU.amalgamate t hT, ?_, ?_⟩
· rintro Z _ ⟨Y, f, g, hg, hf, rfl⟩
rw [op_comp, FunctorToTypes.map_comp_apply, Presieve.IsSheafFor.valid_glue _ _ _ hg]
apply ht hg _ hf
· intro y hy
apply hU.isSeparatedFor.ext
intro Y f hf
apply (hB hf).isSeparatedFor.ext
intro Z g hg
rw [← FunctorToTypes.map_comp_apply, ← op_comp, hy _ (Presieve.bind_comp _ _ hg),
hU.valid_glue _ _ hf, ht hf _ hg]
|
import Mathlib.Analysis.BoxIntegral.Partition.Filter
import Mathlib.Analysis.BoxIntegral.Partition.Measure
import Mathlib.Topology.UniformSpace.Compact
import Mathlib.Init.Data.Bool.Lemmas
#align_import analysis.box_integral.basic from "leanprover-community/mathlib"@"f2ce6086713c78a7f880485f7917ea547a215982"
open scoped Classical Topology NNReal Filter Uniformity BoxIntegral
open Set Finset Function Filter Metric BoxIntegral.IntegrationParams
noncomputable section
namespace BoxIntegral
universe u v w
variable {ι : Type u} {E : Type v} {F : Type w} [NormedAddCommGroup E] [NormedSpace ℝ E]
[NormedAddCommGroup F] [NormedSpace ℝ F] {I J : Box ι} {π : TaggedPrepartition I}
open TaggedPrepartition
local notation "ℝⁿ" => ι → ℝ
def integralSum (f : ℝⁿ → E) (vol : ι →ᵇᵃ E →L[ℝ] F) (π : TaggedPrepartition I) : F :=
∑ J ∈ π.boxes, vol J (f (π.tag J))
#align box_integral.integral_sum BoxIntegral.integralSum
| Mathlib/Analysis/BoxIntegral/Basic.lean | 83 | 87 | theorem integralSum_biUnionTagged (f : ℝⁿ → E) (vol : ι →ᵇᵃ E →L[ℝ] F) (π : Prepartition I)
(πi : ∀ J, TaggedPrepartition J) :
integralSum f vol (π.biUnionTagged πi) = ∑ J ∈ π.boxes, integralSum f vol (πi J) := by |
refine (π.sum_biUnion_boxes _ _).trans <| sum_congr rfl fun J hJ => sum_congr rfl fun J' hJ' => ?_
rw [π.tag_biUnionTagged hJ hJ']
|
import Mathlib.Algebra.Associated
import Mathlib.Algebra.BigOperators.Finsupp
#align_import algebra.big_operators.associated from "leanprover-community/mathlib"@"f7fc89d5d5ff1db2d1242c7bb0e9062ce47ef47c"
variable {α β γ δ : Type*}
-- the same local notation used in `Algebra.Associated`
local infixl:50 " ~ᵤ " => Associated
theorem Prod.associated_iff {M N : Type*} [Monoid M] [Monoid N] {x z : M × N} :
x ~ᵤ z ↔ x.1 ~ᵤ z.1 ∧ x.2 ~ᵤ z.2 :=
⟨fun ⟨u, hu⟩ => ⟨⟨(MulEquiv.prodUnits.toFun u).1, (Prod.eq_iff_fst_eq_snd_eq.1 hu).1⟩,
⟨(MulEquiv.prodUnits.toFun u).2, (Prod.eq_iff_fst_eq_snd_eq.1 hu).2⟩⟩,
fun ⟨⟨u₁, h₁⟩, ⟨u₂, h₂⟩⟩ =>
⟨MulEquiv.prodUnits.invFun (u₁, u₂), Prod.eq_iff_fst_eq_snd_eq.2 ⟨h₁, h₂⟩⟩⟩
| Mathlib/Algebra/BigOperators/Associated.lean | 58 | 69 | theorem Associated.prod {M : Type*} [CommMonoid M] {ι : Type*} (s : Finset ι) (f : ι → M)
(g : ι → M) (h : ∀ i, i ∈ s → (f i) ~ᵤ (g i)) : (∏ i ∈ s, f i) ~ᵤ (∏ i ∈ s, g i) := by |
induction s using Finset.induction with
| empty =>
simp only [Finset.prod_empty]
rfl
| @insert j s hjs IH =>
classical
convert_to (∏ i ∈ insert j s, f i) ~ᵤ (∏ i ∈ insert j s, g i)
rw [Finset.prod_insert hjs, Finset.prod_insert hjs]
exact Associated.mul_mul (h j (Finset.mem_insert_self j s))
(IH (fun i hi ↦ h i (Finset.mem_insert_of_mem hi)))
|
import Mathlib.CategoryTheory.Abelian.Opposite
import Mathlib.CategoryTheory.Abelian.Homology
import Mathlib.Algebra.Homology.Additive
import Mathlib.Algebra.Homology.ShortComplex.HomologicalComplex
#align_import algebra.homology.opposite from "leanprover-community/mathlib"@"8c75ef3517d4106e89fe524e6281d0b0545f47fc"
noncomputable section
open Opposite CategoryTheory CategoryTheory.Limits
section
variable {V : Type*} [Category V] [Abelian V]
| Mathlib/Algebra/Homology/Opposite.lean | 40 | 50 | theorem imageToKernel_op {X Y Z : V} (f : X ⟶ Y) (g : Y ⟶ Z) (w : f ≫ g = 0) :
imageToKernel g.op f.op (by rw [← op_comp, w, op_zero]) =
(imageSubobjectIso _ ≪≫ (imageOpOp _).symm).hom ≫
(cokernel.desc f (factorThruImage g)
(by rw [← cancel_mono (image.ι g), Category.assoc, image.fac, w, zero_comp])).op ≫
(kernelSubobjectIso _ ≪≫ kernelOpOp _).inv := by |
ext
simp only [Iso.trans_hom, Iso.symm_hom, Iso.trans_inv, kernelOpOp_inv, Category.assoc,
imageToKernel_arrow, kernelSubobject_arrow', kernel.lift_ι, ← op_comp, cokernel.π_desc,
← imageSubobject_arrow, ← imageUnopOp_inv_comp_op_factorThruImage g.op]
rfl
|
import Mathlib.Analysis.SpecialFunctions.Gaussian.FourierTransform
import Mathlib.Analysis.Fourier.PoissonSummation
open Real Set MeasureTheory Filter Asymptotics intervalIntegral
open scoped Real Topology FourierTransform RealInnerProductSpace
open Complex hiding exp continuous_exp abs_of_nonneg sq_abs
noncomputable section
section GaussianPoisson
variable {E : Type*} [NormedAddCommGroup E]
lemma rexp_neg_quadratic_isLittleO_rpow_atTop {a : ℝ} (ha : a < 0) (b s : ℝ) :
(fun x ↦ rexp (a * x ^ 2 + b * x)) =o[atTop] (· ^ s) := by
suffices (fun x ↦ rexp (a * x ^ 2 + b * x)) =o[atTop] (fun x ↦ rexp (-x)) by
refine this.trans ?_
simpa only [neg_one_mul] using isLittleO_exp_neg_mul_rpow_atTop zero_lt_one s
rw [isLittleO_exp_comp_exp_comp]
have : (fun x ↦ -x - (a * x ^ 2 + b * x)) = fun x ↦ x * (-a * x - (b + 1)) := by
ext1 x; ring_nf
rw [this]
exact tendsto_id.atTop_mul_atTop <|
Filter.tendsto_atTop_add_const_right _ _ <| tendsto_id.const_mul_atTop (neg_pos.mpr ha)
lemma cexp_neg_quadratic_isLittleO_rpow_atTop {a : ℂ} (ha : a.re < 0) (b : ℂ) (s : ℝ) :
(fun x : ℝ ↦ cexp (a * x ^ 2 + b * x)) =o[atTop] (· ^ s) := by
apply Asymptotics.IsLittleO.of_norm_left
convert rexp_neg_quadratic_isLittleO_rpow_atTop ha b.re s with x
simp_rw [Complex.norm_eq_abs, Complex.abs_exp, add_re, ← ofReal_pow, mul_comm (_ : ℂ) ↑(_ : ℝ),
re_ofReal_mul, mul_comm _ (re _)]
lemma cexp_neg_quadratic_isLittleO_abs_rpow_cocompact {a : ℂ} (ha : a.re < 0) (b : ℂ) (s : ℝ) :
(fun x : ℝ ↦ cexp (a * x ^ 2 + b * x)) =o[cocompact ℝ] (|·| ^ s) := by
rw [cocompact_eq_atBot_atTop, isLittleO_sup]
constructor
· refine ((cexp_neg_quadratic_isLittleO_rpow_atTop ha (-b) s).comp_tendsto
Filter.tendsto_neg_atBot_atTop).congr' (eventually_of_forall fun x ↦ ?_) ?_
· simp only [neg_mul, Function.comp_apply, ofReal_neg, neg_sq, mul_neg, neg_neg]
· refine (eventually_lt_atBot 0).mp (eventually_of_forall fun x hx ↦ ?_)
simp only [Function.comp_apply, abs_of_neg hx]
· refine (cexp_neg_quadratic_isLittleO_rpow_atTop ha b s).congr' EventuallyEq.rfl ?_
refine (eventually_gt_atTop 0).mp (eventually_of_forall fun x hx ↦ ?_)
simp_rw [abs_of_pos hx]
| Mathlib/Analysis/SpecialFunctions/Gaussian/PoissonSummation.lean | 68 | 76 | theorem tendsto_rpow_abs_mul_exp_neg_mul_sq_cocompact {a : ℝ} (ha : 0 < a) (s : ℝ) :
Tendsto (fun x : ℝ => |x| ^ s * rexp (-a * x ^ 2)) (cocompact ℝ) (𝓝 0) := by |
conv in rexp _ => rw [← sq_abs]
erw [cocompact_eq_atBot_atTop, ← comap_abs_atTop,
@tendsto_comap'_iff _ _ _ (fun y => y ^ s * rexp (-a * y ^ 2)) _ _ _
(mem_atTop_sets.mpr ⟨0, fun b hb => ⟨b, abs_of_nonneg hb⟩⟩)]
exact
(rpow_mul_exp_neg_mul_sq_isLittleO_exp_neg ha s).tendsto_zero_of_tendsto
(tendsto_exp_atBot.comp <| tendsto_id.const_mul_atTop_of_neg (neg_lt_zero.mpr one_half_pos))
|
import Mathlib.Topology.UniformSpace.CompleteSeparated
import Mathlib.Topology.EMetricSpace.Lipschitz
import Mathlib.Topology.MetricSpace.Basic
import Mathlib.Topology.MetricSpace.Bounded
#align_import topology.metric_space.antilipschitz from "leanprover-community/mathlib"@"c8f305514e0d47dfaa710f5a52f0d21b588e6328"
variable {α β γ : Type*}
open scoped NNReal ENNReal Uniformity Topology
open Set Filter Bornology
def AntilipschitzWith [PseudoEMetricSpace α] [PseudoEMetricSpace β] (K : ℝ≥0) (f : α → β) :=
∀ x y, edist x y ≤ K * edist (f x) (f y)
#align antilipschitz_with AntilipschitzWith
theorem AntilipschitzWith.edist_lt_top [PseudoEMetricSpace α] [PseudoMetricSpace β] {K : ℝ≥0}
{f : α → β} (h : AntilipschitzWith K f) (x y : α) : edist x y < ⊤ :=
(h x y).trans_lt <| ENNReal.mul_lt_top ENNReal.coe_ne_top (edist_ne_top _ _)
#align antilipschitz_with.edist_lt_top AntilipschitzWith.edist_lt_top
theorem AntilipschitzWith.edist_ne_top [PseudoEMetricSpace α] [PseudoMetricSpace β] {K : ℝ≥0}
{f : α → β} (h : AntilipschitzWith K f) (x y : α) : edist x y ≠ ⊤ :=
(h.edist_lt_top x y).ne
#align antilipschitz_with.edist_ne_top AntilipschitzWith.edist_ne_top
section Metric
variable [PseudoMetricSpace α] [PseudoMetricSpace β] {K : ℝ≥0} {f : α → β}
theorem antilipschitzWith_iff_le_mul_nndist :
AntilipschitzWith K f ↔ ∀ x y, nndist x y ≤ K * nndist (f x) (f y) := by
simp only [AntilipschitzWith, edist_nndist]
norm_cast
#align antilipschitz_with_iff_le_mul_nndist antilipschitzWith_iff_le_mul_nndist
alias ⟨AntilipschitzWith.le_mul_nndist, AntilipschitzWith.of_le_mul_nndist⟩ :=
antilipschitzWith_iff_le_mul_nndist
#align antilipschitz_with.le_mul_nndist AntilipschitzWith.le_mul_nndist
#align antilipschitz_with.of_le_mul_nndist AntilipschitzWith.of_le_mul_nndist
theorem antilipschitzWith_iff_le_mul_dist :
AntilipschitzWith K f ↔ ∀ x y, dist x y ≤ K * dist (f x) (f y) := by
simp only [antilipschitzWith_iff_le_mul_nndist, dist_nndist]
norm_cast
#align antilipschitz_with_iff_le_mul_dist antilipschitzWith_iff_le_mul_dist
alias ⟨AntilipschitzWith.le_mul_dist, AntilipschitzWith.of_le_mul_dist⟩ :=
antilipschitzWith_iff_le_mul_dist
#align antilipschitz_with.le_mul_dist AntilipschitzWith.le_mul_dist
#align antilipschitz_with.of_le_mul_dist AntilipschitzWith.of_le_mul_dist
namespace AntilipschitzWith
variable [PseudoEMetricSpace α] [PseudoEMetricSpace β] [PseudoEMetricSpace γ]
variable {K : ℝ≥0} {f : α → β}
open EMetric
-- uses neither `f` nor `hf`
@[nolint unusedArguments]
protected def k (_hf : AntilipschitzWith K f) : ℝ≥0 := K
set_option linter.uppercaseLean3 false in
#align antilipschitz_with.K AntilipschitzWith.k
protected theorem injective {α : Type*} {β : Type*} [EMetricSpace α] [PseudoEMetricSpace β]
{K : ℝ≥0} {f : α → β} (hf : AntilipschitzWith K f) : Function.Injective f := fun x y h => by
simpa only [h, edist_self, mul_zero, edist_le_zero] using hf x y
#align antilipschitz_with.injective AntilipschitzWith.injective
theorem mul_le_edist (hf : AntilipschitzWith K f) (x y : α) :
(K : ℝ≥0∞)⁻¹ * edist x y ≤ edist (f x) (f y) := by
rw [mul_comm, ← div_eq_mul_inv]
exact ENNReal.div_le_of_le_mul' (hf x y)
#align antilipschitz_with.mul_le_edist AntilipschitzWith.mul_le_edist
theorem ediam_preimage_le (hf : AntilipschitzWith K f) (s : Set β) : diam (f ⁻¹' s) ≤ K * diam s :=
diam_le fun x hx y hy => (hf x y).trans <|
mul_le_mul_left' (edist_le_diam_of_mem (mem_preimage.1 hx) hy) K
#align antilipschitz_with.ediam_preimage_le AntilipschitzWith.ediam_preimage_le
theorem le_mul_ediam_image (hf : AntilipschitzWith K f) (s : Set α) : diam s ≤ K * diam (f '' s) :=
(diam_mono (subset_preimage_image _ _)).trans (hf.ediam_preimage_le (f '' s))
#align antilipschitz_with.le_mul_ediam_image AntilipschitzWith.le_mul_ediam_image
protected theorem id : AntilipschitzWith 1 (id : α → α) := fun x y => by
simp only [ENNReal.coe_one, one_mul, id, le_refl]
#align antilipschitz_with.id AntilipschitzWith.id
| Mathlib/Topology/MetricSpace/Antilipschitz.lean | 129 | 134 | theorem comp {Kg : ℝ≥0} {g : β → γ} (hg : AntilipschitzWith Kg g) {Kf : ℝ≥0} {f : α → β}
(hf : AntilipschitzWith Kf f) : AntilipschitzWith (Kf * Kg) (g ∘ f) := fun x y =>
calc
edist x y ≤ Kf * edist (f x) (f y) := hf x y
_ ≤ Kf * (Kg * edist (g (f x)) (g (f y))) := ENNReal.mul_left_mono (hg _ _)
_ = _ := by | rw [ENNReal.coe_mul, mul_assoc]; rfl
|
import Mathlib.Topology.Separation
#align_import topology.sober from "leanprover-community/mathlib"@"0a0ec35061ed9960bf0e7ffb0335f44447b58977"
open Set
variable {α β : Type*} [TopologicalSpace α] [TopologicalSpace β]
section genericPoint
def IsGenericPoint (x : α) (S : Set α) : Prop :=
closure ({x} : Set α) = S
#align is_generic_point IsGenericPoint
theorem isGenericPoint_def {x : α} {S : Set α} : IsGenericPoint x S ↔ closure ({x} : Set α) = S :=
Iff.rfl
#align is_generic_point_def isGenericPoint_def
theorem IsGenericPoint.def {x : α} {S : Set α} (h : IsGenericPoint x S) :
closure ({x} : Set α) = S :=
h
#align is_generic_point.def IsGenericPoint.def
theorem isGenericPoint_closure {x : α} : IsGenericPoint x (closure ({x} : Set α)) :=
refl _
#align is_generic_point_closure isGenericPoint_closure
variable {x y : α} {S U Z : Set α}
theorem isGenericPoint_iff_specializes : IsGenericPoint x S ↔ ∀ y, x ⤳ y ↔ y ∈ S := by
simp only [specializes_iff_mem_closure, IsGenericPoint, Set.ext_iff]
#align is_generic_point_iff_specializes isGenericPoint_iff_specializes
section Sober
@[mk_iff]
class QuasiSober (α : Type*) [TopologicalSpace α] : Prop where
sober : ∀ {S : Set α}, IsIrreducible S → IsClosed S → ∃ x, IsGenericPoint x S
#align quasi_sober QuasiSober
noncomputable def IsIrreducible.genericPoint [QuasiSober α] {S : Set α} (hS : IsIrreducible S) :
α :=
(QuasiSober.sober hS.closure isClosed_closure).choose
#align is_irreducible.generic_point IsIrreducible.genericPoint
theorem IsIrreducible.genericPoint_spec [QuasiSober α] {S : Set α} (hS : IsIrreducible S) :
IsGenericPoint hS.genericPoint (closure S) :=
(QuasiSober.sober hS.closure isClosed_closure).choose_spec
#align is_irreducible.generic_point_spec IsIrreducible.genericPoint_spec
@[simp]
theorem IsIrreducible.genericPoint_closure_eq [QuasiSober α] {S : Set α} (hS : IsIrreducible S) :
closure ({hS.genericPoint} : Set α) = closure S :=
hS.genericPoint_spec
#align is_irreducible.generic_point_closure_eq IsIrreducible.genericPoint_closure_eq
variable (α)
noncomputable def genericPoint [QuasiSober α] [IrreducibleSpace α] : α :=
(IrreducibleSpace.isIrreducible_univ α).genericPoint
#align generic_point genericPoint
| Mathlib/Topology/Sober.lean | 148 | 150 | theorem genericPoint_spec [QuasiSober α] [IrreducibleSpace α] :
IsGenericPoint (genericPoint α) ⊤ := by |
simpa using (IrreducibleSpace.isIrreducible_univ α).genericPoint_spec
|
import Mathlib.Algebra.Polynomial.FieldDivision
import Mathlib.FieldTheory.Minpoly.Basic
import Mathlib.RingTheory.Algebraic
#align_import field_theory.minpoly.field from "leanprover-community/mathlib"@"cbdf7b565832144d024caa5a550117c6df0204a5"
open scoped Classical
open Polynomial Set Function minpoly
namespace minpoly
variable {A B : Type*}
variable (A) [Field A]
section Ring
variable [Ring B] [Algebra A B] (x : B)
theorem degree_le_of_ne_zero {p : A[X]} (pnz : p ≠ 0) (hp : Polynomial.aeval x p = 0) :
degree (minpoly A x) ≤ degree p :=
calc
degree (minpoly A x) ≤ degree (p * C (leadingCoeff p)⁻¹) :=
min A x (monic_mul_leadingCoeff_inv pnz) (by simp [hp])
_ = degree p := degree_mul_leadingCoeff_inv p pnz
#align minpoly.degree_le_of_ne_zero minpoly.degree_le_of_ne_zero
theorem ne_zero_of_finite (e : B) [FiniteDimensional A B] : minpoly A e ≠ 0 :=
minpoly.ne_zero <| .of_finite A _
#align minpoly.ne_zero_of_finite_field_extension minpoly.ne_zero_of_finite
theorem unique {p : A[X]} (pmonic : p.Monic) (hp : Polynomial.aeval x p = 0)
(pmin : ∀ q : A[X], q.Monic → Polynomial.aeval x q = 0 → degree p ≤ degree q) :
p = minpoly A x := by
have hx : IsIntegral A x := ⟨p, pmonic, hp⟩
symm; apply eq_of_sub_eq_zero
by_contra hnz
apply degree_le_of_ne_zero A x hnz (by simp [hp]) |>.not_lt
apply degree_sub_lt _ (minpoly.ne_zero hx)
· rw [(monic hx).leadingCoeff, pmonic.leadingCoeff]
· exact le_antisymm (min A x pmonic hp) (pmin (minpoly A x) (monic hx) (aeval A x))
#align minpoly.unique minpoly.unique
theorem dvd {p : A[X]} (hp : Polynomial.aeval x p = 0) : minpoly A x ∣ p := by
by_cases hp0 : p = 0
· simp only [hp0, dvd_zero]
have hx : IsIntegral A x := IsAlgebraic.isIntegral ⟨p, hp0, hp⟩
rw [← modByMonic_eq_zero_iff_dvd (monic hx)]
by_contra hnz
apply degree_le_of_ne_zero A x hnz
((aeval_modByMonic_eq_self_of_root (monic hx) (aeval _ _)).trans hp) |>.not_lt
exact degree_modByMonic_lt _ (monic hx)
#align minpoly.dvd minpoly.dvd
variable {A x} in
lemma dvd_iff {p : A[X]} : minpoly A x ∣ p ↔ Polynomial.aeval x p = 0 :=
⟨fun ⟨q, hq⟩ ↦ by rw [hq, map_mul, aeval, zero_mul], minpoly.dvd A x⟩
theorem isRadical [IsReduced B] : IsRadical (minpoly A x) := fun n p dvd ↦ by
rw [dvd_iff] at dvd ⊢; rw [map_pow] at dvd; exact IsReduced.eq_zero _ ⟨n, dvd⟩
theorem dvd_map_of_isScalarTower (A K : Type*) {R : Type*} [CommRing A] [Field K] [CommRing R]
[Algebra A K] [Algebra A R] [Algebra K R] [IsScalarTower A K R] (x : R) :
minpoly K x ∣ (minpoly A x).map (algebraMap A K) := by
refine minpoly.dvd K x ?_
rw [aeval_map_algebraMap, minpoly.aeval]
#align minpoly.dvd_map_of_is_scalar_tower minpoly.dvd_map_of_isScalarTower
| Mathlib/FieldTheory/Minpoly/Field.lean | 93 | 99 | theorem dvd_map_of_isScalarTower' (R : Type*) {S : Type*} (K L : Type*) [CommRing R]
[CommRing S] [Field K] [CommRing L] [Algebra R S] [Algebra R K] [Algebra S L] [Algebra K L]
[Algebra R L] [IsScalarTower R K L] [IsScalarTower R S L] (s : S) :
minpoly K (algebraMap S L s) ∣ map (algebraMap R K) (minpoly R s) := by |
apply minpoly.dvd K (algebraMap S L s)
rw [← map_aeval_eq_aeval_map, minpoly.aeval, map_zero]
rw [← IsScalarTower.algebraMap_eq, ← IsScalarTower.algebraMap_eq]
|
import Mathlib.Dynamics.PeriodicPts
import Mathlib.GroupTheory.Exponent
import Mathlib.GroupTheory.GroupAction.Basic
namespace MulAction
universe u v
variable {α : Type v}
variable {G : Type u} [Group G] [MulAction G α]
variable {M : Type u} [Monoid M] [MulAction M α]
@[to_additive "If the action is periodic, then a lower bound for its period can be computed."]
theorem le_period {m : M} {a : α} {n : ℕ} (period_pos : 0 < period m a)
(moved : ∀ k, 0 < k → k < n → m ^ k • a ≠ a) : n ≤ period m a :=
le_of_not_gt fun period_lt_n =>
moved _ period_pos period_lt_n <| pow_period_smul m a
@[to_additive "If for some `n`, `(n • m) +ᵥ a = a`, then `period m a ≤ n`."]
theorem period_le_of_fixed {m : M} {a : α} {n : ℕ} (n_pos : 0 < n) (fixed : m ^ n • a = a) :
period m a ≤ n :=
(isPeriodicPt_smul_iff.mpr fixed).minimalPeriod_le n_pos
@[to_additive "If for some `n`, `(n • m) +ᵥ a = a`, then `0 < period m a`."]
theorem period_pos_of_fixed {m : M} {a : α} {n : ℕ} (n_pos : 0 < n) (fixed : m ^ n • a = a) :
0 < period m a :=
(isPeriodicPt_smul_iff.mpr fixed).minimalPeriod_pos n_pos
@[to_additive]
theorem period_eq_one_iff {m : M} {a : α} : period m a = 1 ↔ m • a = a :=
⟨fun eq_one => pow_one m ▸ eq_one ▸ pow_period_smul m a,
fun fixed => le_antisymm
(period_le_of_fixed one_pos (by simpa))
(period_pos_of_fixed one_pos (by simpa))⟩
@[to_additive "For any non-zero `n` less than the period of `m` on `a`, `a` is moved by `n • m`."]
theorem pow_smul_ne_of_lt_period {m : M} {a : α} {n : ℕ} (n_pos : 0 < n)
(n_lt_period : n < period m a) : m ^ n • a ≠ a := fun a_fixed =>
not_le_of_gt n_lt_period <| period_le_of_fixed n_pos a_fixed
section Identities
variable (M) in
@[to_additive (attr := simp)]
theorem period_one (a : α) : period (1 : M) a = 1 := period_eq_one_iff.mpr (one_smul M a)
@[to_additive (attr := simp)]
| Mathlib/GroupTheory/GroupAction/Period.lean | 71 | 75 | theorem period_inv (g : G) (a : α) : period g⁻¹ a = period g a := by |
simp only [period_eq_minimalPeriod, Function.minimalPeriod_eq_minimalPeriod_iff,
isPeriodicPt_smul_iff]
intro n
rw [smul_eq_iff_eq_inv_smul, eq_comm, ← zpow_natCast, inv_zpow, inv_inv, zpow_natCast]
|
import Mathlib.Data.Matrix.Invertible
import Mathlib.LinearAlgebra.Matrix.NonsingularInverse
import Mathlib.LinearAlgebra.Matrix.PosDef
#align_import linear_algebra.matrix.schur_complement from "leanprover-community/mathlib"@"a176cb1219e300e85793d44583dede42377b51af"
variable {l m n α : Type*}
namespace Matrix
open scoped Matrix
section CommRing
variable [Fintype l] [Fintype m] [Fintype n]
variable [DecidableEq l] [DecidableEq m] [DecidableEq n]
variable [CommRing α]
theorem fromBlocks_eq_of_invertible₁₁ (A : Matrix m m α) (B : Matrix m n α) (C : Matrix l m α)
(D : Matrix l n α) [Invertible A] :
fromBlocks A B C D =
fromBlocks 1 0 (C * ⅟ A) 1 * fromBlocks A 0 0 (D - C * ⅟ A * B) *
fromBlocks 1 (⅟ A * B) 0 1 := by
simp only [fromBlocks_multiply, Matrix.mul_zero, Matrix.zero_mul, add_zero, zero_add,
Matrix.one_mul, Matrix.mul_one, invOf_mul_self, Matrix.mul_invOf_self_assoc,
Matrix.mul_invOf_mul_self_cancel, Matrix.mul_assoc, add_sub_cancel]
#align matrix.from_blocks_eq_of_invertible₁₁ Matrix.fromBlocks_eq_of_invertible₁₁
theorem fromBlocks_eq_of_invertible₂₂ (A : Matrix l m α) (B : Matrix l n α) (C : Matrix n m α)
(D : Matrix n n α) [Invertible D] :
fromBlocks A B C D =
fromBlocks 1 (B * ⅟ D) 0 1 * fromBlocks (A - B * ⅟ D * C) 0 0 D *
fromBlocks 1 0 (⅟ D * C) 1 :=
(Matrix.reindex (Equiv.sumComm _ _) (Equiv.sumComm _ _)).injective <| by
simpa [reindex_apply, Equiv.sumComm_symm, ← submatrix_mul_equiv _ _ _ (Equiv.sumComm n m), ←
submatrix_mul_equiv _ _ _ (Equiv.sumComm n l), Equiv.sumComm_apply,
fromBlocks_submatrix_sum_swap_sum_swap] using fromBlocks_eq_of_invertible₁₁ D C B A
#align matrix.from_blocks_eq_of_invertible₂₂ Matrix.fromBlocks_eq_of_invertible₂₂
section Det
theorem det_fromBlocks₁₁ (A : Matrix m m α) (B : Matrix m n α) (C : Matrix n m α)
(D : Matrix n n α) [Invertible A] :
(Matrix.fromBlocks A B C D).det = det A * det (D - C * ⅟ A * B) := by
rw [fromBlocks_eq_of_invertible₁₁ (A := A), det_mul, det_mul, det_fromBlocks_zero₂₁,
det_fromBlocks_zero₂₁, det_fromBlocks_zero₁₂, det_one, det_one, one_mul, one_mul, mul_one]
#align matrix.det_from_blocks₁₁ Matrix.det_fromBlocks₁₁
@[simp]
theorem det_fromBlocks_one₁₁ (B : Matrix m n α) (C : Matrix n m α) (D : Matrix n n α) :
(Matrix.fromBlocks 1 B C D).det = det (D - C * B) := by
haveI : Invertible (1 : Matrix m m α) := invertibleOne
rw [det_fromBlocks₁₁, invOf_one, Matrix.mul_one, det_one, one_mul]
#align matrix.det_from_blocks_one₁₁ Matrix.det_fromBlocks_one₁₁
theorem det_fromBlocks₂₂ (A : Matrix m m α) (B : Matrix m n α) (C : Matrix n m α)
(D : Matrix n n α) [Invertible D] :
(Matrix.fromBlocks A B C D).det = det D * det (A - B * ⅟ D * C) := by
have : fromBlocks A B C D =
(fromBlocks D C B A).submatrix (Equiv.sumComm _ _) (Equiv.sumComm _ _) := by
ext (i j)
cases i <;> cases j <;> rfl
rw [this, det_submatrix_equiv_self, det_fromBlocks₁₁]
#align matrix.det_from_blocks₂₂ Matrix.det_fromBlocks₂₂
@[simp]
theorem det_fromBlocks_one₂₂ (A : Matrix m m α) (B : Matrix m n α) (C : Matrix n m α) :
(Matrix.fromBlocks A B C 1).det = det (A - B * C) := by
haveI : Invertible (1 : Matrix n n α) := invertibleOne
rw [det_fromBlocks₂₂, invOf_one, Matrix.mul_one, det_one, one_mul]
#align matrix.det_from_blocks_one₂₂ Matrix.det_fromBlocks_one₂₂
theorem det_one_add_mul_comm (A : Matrix m n α) (B : Matrix n m α) :
det (1 + A * B) = det (1 + B * A) :=
calc
det (1 + A * B) = det (fromBlocks 1 (-A) B 1) := by
rw [det_fromBlocks_one₂₂, Matrix.neg_mul, sub_neg_eq_add]
_ = det (1 + B * A) := by rw [det_fromBlocks_one₁₁, Matrix.mul_neg, sub_neg_eq_add]
#align matrix.det_one_add_mul_comm Matrix.det_one_add_mul_comm
theorem det_mul_add_one_comm (A : Matrix m n α) (B : Matrix n m α) :
det (A * B + 1) = det (B * A + 1) := by rw [add_comm, det_one_add_mul_comm, add_comm]
#align matrix.det_mul_add_one_comm Matrix.det_mul_add_one_comm
theorem det_one_sub_mul_comm (A : Matrix m n α) (B : Matrix n m α) :
det (1 - A * B) = det (1 - B * A) := by
rw [sub_eq_add_neg, ← Matrix.neg_mul, det_one_add_mul_comm, Matrix.mul_neg, ← sub_eq_add_neg]
#align matrix.det_one_sub_mul_comm Matrix.det_one_sub_mul_comm
theorem det_one_add_col_mul_row (u v : m → α) : det (1 + col u * row v) = 1 + v ⬝ᵥ u := by
rw [det_one_add_mul_comm, det_unique, Pi.add_apply, Pi.add_apply, Matrix.one_apply_eq,
Matrix.row_mul_col_apply]
#align matrix.det_one_add_col_mul_row Matrix.det_one_add_col_mul_row
| Mathlib/LinearAlgebra/Matrix/SchurComplement.lean | 454 | 459 | theorem det_add_col_mul_row {A : Matrix m m α} (hA : IsUnit A.det) (u v : m → α) :
(A + col u * row v).det = A.det * (1 + row v * A⁻¹ * col u).det := by |
nth_rewrite 1 [← Matrix.mul_one A]
rwa [← Matrix.mul_nonsing_inv_cancel_left A (col u * row v),
← Matrix.mul_add, det_mul, ← Matrix.mul_assoc, det_one_add_mul_comm,
← Matrix.mul_assoc]
|
import Mathlib.MeasureTheory.Measure.Sub
import Mathlib.MeasureTheory.Decomposition.SignedHahn
import Mathlib.MeasureTheory.Function.AEEqOfIntegral
#align_import measure_theory.decomposition.lebesgue from "leanprover-community/mathlib"@"b2ff9a3d7a15fd5b0f060b135421d6a89a999c2f"
open scoped MeasureTheory NNReal ENNReal
open Set
namespace MeasureTheory
namespace Measure
variable {α β : Type*} {m : MeasurableSpace α} {μ ν : Measure α}
class HaveLebesgueDecomposition (μ ν : Measure α) : Prop where
lebesgue_decomposition :
∃ p : Measure α × (α → ℝ≥0∞), Measurable p.2 ∧ p.1 ⟂ₘ ν ∧ μ = p.1 + ν.withDensity p.2
#align measure_theory.measure.have_lebesgue_decomposition MeasureTheory.Measure.HaveLebesgueDecomposition
#align measure_theory.measure.have_lebesgue_decomposition.lebesgue_decomposition MeasureTheory.Measure.HaveLebesgueDecomposition.lebesgue_decomposition
open Classical in
noncomputable irreducible_def singularPart (μ ν : Measure α) : Measure α :=
if h : HaveLebesgueDecomposition μ ν then (Classical.choose h.lebesgue_decomposition).1 else 0
#align measure_theory.measure.singular_part MeasureTheory.Measure.singularPart
open Classical in
noncomputable irreducible_def rnDeriv (μ ν : Measure α) : α → ℝ≥0∞ :=
if h : HaveLebesgueDecomposition μ ν then (Classical.choose h.lebesgue_decomposition).2 else 0
#align measure_theory.measure.rn_deriv MeasureTheory.Measure.rnDeriv
section ByDefinition
| Mathlib/MeasureTheory/Decomposition/Lebesgue.lean | 86 | 90 | theorem haveLebesgueDecomposition_spec (μ ν : Measure α) [h : HaveLebesgueDecomposition μ ν] :
Measurable (μ.rnDeriv ν) ∧
μ.singularPart ν ⟂ₘ ν ∧ μ = μ.singularPart ν + ν.withDensity (μ.rnDeriv ν) := by |
rw [singularPart, rnDeriv, dif_pos h, dif_pos h]
exact Classical.choose_spec h.lebesgue_decomposition
|
import Mathlib.Order.BooleanAlgebra
import Mathlib.Tactic.Common
#align_import order.heyting.boundary from "leanprover-community/mathlib"@"70d50ecfd4900dd6d328da39ab7ebd516abe4025"
variable {α : Type*}
namespace Coheyting
variable [CoheytingAlgebra α] {a b : α}
def boundary (a : α) : α :=
a ⊓ ￢a
#align coheyting.boundary Coheyting.boundary
scoped[Heyting] prefix:120 "∂ " => Coheyting.boundary
-- Porting note: Should the notation be automatically included in the current scope?
open Heyting
-- Porting note: Should hnot be named hNot?
theorem inf_hnot_self (a : α) : a ⊓ ￢a = ∂ a :=
rfl
#align coheyting.inf_hnot_self Coheyting.inf_hnot_self
theorem boundary_le : ∂ a ≤ a :=
inf_le_left
#align coheyting.boundary_le Coheyting.boundary_le
theorem boundary_le_hnot : ∂ a ≤ ￢a :=
inf_le_right
#align coheyting.boundary_le_hnot Coheyting.boundary_le_hnot
@[simp]
theorem boundary_bot : ∂ (⊥ : α) = ⊥ := bot_inf_eq _
#align coheyting.boundary_bot Coheyting.boundary_bot
@[simp]
theorem boundary_top : ∂ (⊤ : α) = ⊥ := by rw [boundary, hnot_top, inf_bot_eq]
#align coheyting.boundary_top Coheyting.boundary_top
theorem boundary_hnot_le (a : α) : ∂ (￢a) ≤ ∂ a :=
(inf_comm _ _).trans_le <| inf_le_inf_right _ hnot_hnot_le
#align coheyting.boundary_hnot_le Coheyting.boundary_hnot_le
@[simp]
| Mathlib/Order/Heyting/Boundary.lean | 71 | 72 | theorem boundary_hnot_hnot (a : α) : ∂ (￢￢a) = ∂ (￢a) := by |
simp_rw [boundary, hnot_hnot_hnot, inf_comm]
|
import Mathlib.Init.Logic
import Mathlib.Init.Function
import Mathlib.Init.Algebra.Classes
import Batteries.Util.LibraryNote
import Batteries.Tactic.Lint.Basic
#align_import logic.basic from "leanprover-community/mathlib"@"3365b20c2ffa7c35e47e5209b89ba9abdddf3ffe"
#align_import init.ite_simp from "leanprover-community/lean"@"4a03bdeb31b3688c31d02d7ff8e0ff2e5d6174db"
open Function
attribute [local instance 10] Classical.propDecidable
open Function
alias Membership.mem.ne_of_not_mem := ne_of_mem_of_not_mem
alias Membership.mem.ne_of_not_mem' := ne_of_mem_of_not_mem'
#align has_mem.mem.ne_of_not_mem Membership.mem.ne_of_not_mem
#align has_mem.mem.ne_of_not_mem' Membership.mem.ne_of_not_mem'
section Quantifiers
set_option autoImplicit true in
-- @[elab_as_elim] -- FIXME
noncomputable def Exists.classicalRecOn {p : α → Prop} (h : ∃ a, p a) {C} (H : ∀ a, p a → C) : C :=
H (Classical.choose h) (Classical.choose_spec h)
#align exists.classical_rec_on Exists.classicalRecOn
section BoundedQuantifiers
variable {α : Sort*} {r p q : α → Prop} {P Q : ∀ x, p x → Prop} {b : Prop}
theorem bex_def : (∃ (x : _) (_ : p x), q x) ↔ ∃ x, p x ∧ q x :=
⟨fun ⟨x, px, qx⟩ ↦ ⟨x, px, qx⟩, fun ⟨x, px, qx⟩ ↦ ⟨x, px, qx⟩⟩
#align bex_def bex_def
theorem BEx.elim {b : Prop} : (∃ x h, P x h) → (∀ a h, P a h → b) → b
| ⟨a, h₁, h₂⟩, h' => h' a h₁ h₂
#align bex.elim BEx.elim
theorem BEx.intro (a : α) (h₁ : p a) (h₂ : P a h₁) : ∃ (x : _) (h : p x), P x h :=
⟨a, h₁, h₂⟩
#align bex.intro BEx.intro
#align ball_congr forall₂_congr
#align bex_congr exists₂_congr
@[deprecated exists_eq_left (since := "2024-04-06")]
| Mathlib/Logic/Basic.lean | 1,092 | 1,093 | theorem bex_eq_left {a : α} : (∃ (x : _) (_ : x = a), p x) ↔ p a := by |
simp only [exists_prop, exists_eq_left]
|
import Mathlib.LinearAlgebra.Dimension.Free
import Mathlib.Algebra.Homology.ShortComplex.ModuleCat
open CategoryTheory
namespace ModuleCat
variable {ι ι' R : Type*} [Ring R] {S : ShortComplex (ModuleCat R)}
(hS : S.Exact) (hS' : S.ShortExact) {v : ι → S.X₁}
open CategoryTheory Submodule Set
section LinearIndependent
variable (hv : LinearIndependent R v) {u : ι ⊕ ι' → S.X₂}
(hw : LinearIndependent R (S.g ∘ u ∘ Sum.inr))
(hm : Mono S.f) (huv : u ∘ Sum.inl = S.f ∘ v)
theorem disjoint_span_sum : Disjoint (span R (range (u ∘ Sum.inl)))
(span R (range (u ∘ Sum.inr))) := by
rw [huv, disjoint_comm]
refine Disjoint.mono_right (span_mono (range_comp_subset_range _ _)) ?_
rw [← LinearMap.range_coe, span_eq (LinearMap.range S.f), hS.moduleCat_range_eq_ker]
exact range_ker_disjoint hw
theorem linearIndependent_leftExact : LinearIndependent R u := by
rw [linearIndependent_sum]
refine ⟨?_, LinearIndependent.of_comp S.g hw, disjoint_span_sum hS hw huv⟩
rw [huv, LinearMap.linearIndependent_iff S.f]; swap
· rw [LinearMap.ker_eq_bot, ← mono_iff_injective]
infer_instance
exact hv
| Mathlib/Algebra/Category/ModuleCat/Free.lean | 72 | 78 | theorem linearIndependent_shortExact {w : ι' → S.X₃} (hw : LinearIndependent R w) :
LinearIndependent R (Sum.elim (S.f ∘ v) (S.g.toFun.invFun ∘ w)) := by |
apply linearIndependent_leftExact hS'.exact hv _ hS'.mono_f rfl
dsimp
convert hw
ext
apply Function.rightInverse_invFun ((epi_iff_surjective _).mp hS'.epi_g)
|
import Mathlib.Algebra.Order.Ring.Defs
import Mathlib.Combinatorics.SimpleGraph.Basic
import Mathlib.Data.Sym.Card
open Finset Function
namespace SimpleGraph
variable {V : Type*} (G : SimpleGraph V) {e : Sym2 V}
section EdgeFinset
variable {G₁ G₂ : SimpleGraph V} [Fintype G.edgeSet] [Fintype G₁.edgeSet] [Fintype G₂.edgeSet]
abbrev edgeFinset : Finset (Sym2 V) :=
Set.toFinset G.edgeSet
#align simple_graph.edge_finset SimpleGraph.edgeFinset
@[norm_cast]
theorem coe_edgeFinset : (G.edgeFinset : Set (Sym2 V)) = G.edgeSet :=
Set.coe_toFinset _
#align simple_graph.coe_edge_finset SimpleGraph.coe_edgeFinset
variable {G}
theorem mem_edgeFinset : e ∈ G.edgeFinset ↔ e ∈ G.edgeSet :=
Set.mem_toFinset
#align simple_graph.mem_edge_finset SimpleGraph.mem_edgeFinset
theorem not_isDiag_of_mem_edgeFinset : e ∈ G.edgeFinset → ¬e.IsDiag :=
not_isDiag_of_mem_edgeSet _ ∘ mem_edgeFinset.1
#align simple_graph.not_is_diag_of_mem_edge_finset SimpleGraph.not_isDiag_of_mem_edgeFinset
| Mathlib/Combinatorics/SimpleGraph/Finite.lean | 72 | 72 | theorem edgeFinset_inj : G₁.edgeFinset = G₂.edgeFinset ↔ G₁ = G₂ := by | simp
|
import Mathlib.Algebra.Field.Defs
import Mathlib.Algebra.GroupWithZero.Units.Lemmas
import Mathlib.Algebra.Ring.Commute
import Mathlib.Algebra.Ring.Invertible
import Mathlib.Order.Synonym
#align_import algebra.field.basic from "leanprover-community/mathlib"@"05101c3df9d9cfe9430edc205860c79b6d660102"
open Function OrderDual Set
universe u
variable {α β K : Type*}
section DivisionSemiring
variable [DivisionSemiring α] {a b c d : α}
| Mathlib/Algebra/Field/Basic.lean | 29 | 29 | theorem add_div (a b c : α) : (a + b) / c = a / c + b / c := by | simp_rw [div_eq_mul_inv, add_mul]
|
import Mathlib.MeasureTheory.Measure.MeasureSpace
import Mathlib.MeasureTheory.Constructions.BorelSpace.Basic
#align_import measure_theory.measure.open_pos from "leanprover-community/mathlib"@"f2ce6086713c78a7f880485f7917ea547a215982"
open Topology ENNReal MeasureTheory
open Set Function Filter
namespace MeasureTheory
namespace Measure
section Basic
variable {X Y : Type*} [TopologicalSpace X] {m : MeasurableSpace X} [TopologicalSpace Y]
[T2Space Y] (μ ν : Measure X)
class IsOpenPosMeasure : Prop where
open_pos : ∀ U : Set X, IsOpen U → U.Nonempty → μ U ≠ 0
#align measure_theory.measure.is_open_pos_measure MeasureTheory.Measure.IsOpenPosMeasure
variable [IsOpenPosMeasure μ] {s U F : Set X} {x : X}
theorem _root_.IsOpen.measure_ne_zero (hU : IsOpen U) (hne : U.Nonempty) : μ U ≠ 0 :=
IsOpenPosMeasure.open_pos U hU hne
#align is_open.measure_ne_zero IsOpen.measure_ne_zero
theorem _root_.IsOpen.measure_pos (hU : IsOpen U) (hne : U.Nonempty) : 0 < μ U :=
(hU.measure_ne_zero μ hne).bot_lt
#align is_open.measure_pos IsOpen.measure_pos
instance (priority := 100) [Nonempty X] : NeZero μ :=
⟨measure_univ_pos.mp <| isOpen_univ.measure_pos μ univ_nonempty⟩
theorem _root_.IsOpen.measure_pos_iff (hU : IsOpen U) : 0 < μ U ↔ U.Nonempty :=
⟨fun h => nonempty_iff_ne_empty.2 fun he => h.ne' <| he.symm ▸ measure_empty, hU.measure_pos μ⟩
#align is_open.measure_pos_iff IsOpen.measure_pos_iff
theorem _root_.IsOpen.measure_eq_zero_iff (hU : IsOpen U) : μ U = 0 ↔ U = ∅ := by
simpa only [not_lt, nonpos_iff_eq_zero, not_nonempty_iff_eq_empty] using
not_congr (hU.measure_pos_iff μ)
#align is_open.measure_eq_zero_iff IsOpen.measure_eq_zero_iff
theorem measure_pos_of_nonempty_interior (h : (interior s).Nonempty) : 0 < μ s :=
(isOpen_interior.measure_pos μ h).trans_le (measure_mono interior_subset)
#align measure_theory.measure.measure_pos_of_nonempty_interior MeasureTheory.Measure.measure_pos_of_nonempty_interior
theorem measure_pos_of_mem_nhds (h : s ∈ 𝓝 x) : 0 < μ s :=
measure_pos_of_nonempty_interior _ ⟨x, mem_interior_iff_mem_nhds.2 h⟩
#align measure_theory.measure.measure_pos_of_mem_nhds MeasureTheory.Measure.measure_pos_of_mem_nhds
theorem isOpenPosMeasure_smul {c : ℝ≥0∞} (h : c ≠ 0) : IsOpenPosMeasure (c • μ) :=
⟨fun _U Uo Une => mul_ne_zero h (Uo.measure_ne_zero μ Une)⟩
#align measure_theory.measure.is_open_pos_measure_smul MeasureTheory.Measure.isOpenPosMeasure_smul
variable {μ ν}
protected theorem AbsolutelyContinuous.isOpenPosMeasure (h : μ ≪ ν) : IsOpenPosMeasure ν :=
⟨fun _U ho hne h₀ => ho.measure_ne_zero μ hne (h h₀)⟩
#align measure_theory.measure.absolutely_continuous.is_open_pos_measure MeasureTheory.Measure.AbsolutelyContinuous.isOpenPosMeasure
theorem _root_.LE.le.isOpenPosMeasure (h : μ ≤ ν) : IsOpenPosMeasure ν :=
h.absolutelyContinuous.isOpenPosMeasure
#align has_le.le.is_open_pos_measure LE.le.isOpenPosMeasure
theorem _root_.IsOpen.measure_zero_iff_eq_empty (hU : IsOpen U) :
μ U = 0 ↔ U = ∅ :=
⟨fun h ↦ (hU.measure_eq_zero_iff μ).mp h, fun h ↦ by simp [h]⟩
theorem _root_.IsOpen.ae_eq_empty_iff_eq (hU : IsOpen U) :
U =ᵐ[μ] (∅ : Set X) ↔ U = ∅ := by
rw [ae_eq_empty, hU.measure_zero_iff_eq_empty]
theorem _root_.IsOpen.eq_empty_of_measure_zero (hU : IsOpen U) (h₀ : μ U = 0) : U = ∅ :=
(hU.measure_eq_zero_iff μ).mp h₀
#align is_open.eq_empty_of_measure_zero IsOpen.eq_empty_of_measure_zero
theorem _root_.IsClosed.ae_eq_univ_iff_eq (hF : IsClosed F) :
F =ᵐ[μ] univ ↔ F = univ := by
refine ⟨fun h ↦ ?_, fun h ↦ by rw [h]⟩
rwa [ae_eq_univ, hF.isOpen_compl.measure_eq_zero_iff μ, compl_empty_iff] at h
theorem _root_.IsClosed.measure_eq_univ_iff_eq [OpensMeasurableSpace X] [IsFiniteMeasure μ]
(hF : IsClosed F) :
μ F = μ univ ↔ F = univ := by
rw [← ae_eq_univ_iff_measure_eq hF.measurableSet.nullMeasurableSet, hF.ae_eq_univ_iff_eq]
| Mathlib/MeasureTheory/Measure/OpenPos.lean | 107 | 110 | theorem _root_.IsClosed.measure_eq_one_iff_eq_univ [OpensMeasurableSpace X] [IsProbabilityMeasure μ]
(hF : IsClosed F) :
μ F = 1 ↔ F = univ := by |
rw [← measure_univ (μ := μ), hF.measure_eq_univ_iff_eq]
|
import Mathlib.Analysis.InnerProductSpace.PiL2
import Mathlib.LinearAlgebra.Matrix.Block
#align_import analysis.inner_product_space.gram_schmidt_ortho from "leanprover-community/mathlib"@"1a4df69ca1a9a0e5e26bfe12e2b92814216016d0"
open Finset Submodule FiniteDimensional
variable (𝕜 : Type*) {E : Type*} [RCLike 𝕜] [NormedAddCommGroup E] [InnerProductSpace 𝕜 E]
variable {ι : Type*} [LinearOrder ι] [LocallyFiniteOrderBot ι] [IsWellOrder ι (· < ·)]
attribute [local instance] IsWellOrder.toHasWellFounded
local notation "⟪" x ", " y "⟫" => @inner 𝕜 _ _ x y
noncomputable def gramSchmidt [IsWellOrder ι (· < ·)] (f : ι → E) (n : ι) : E :=
f n - ∑ i : Iio n, orthogonalProjection (𝕜 ∙ gramSchmidt f i) (f n)
termination_by n
decreasing_by exact mem_Iio.1 i.2
#align gram_schmidt gramSchmidt
theorem gramSchmidt_def (f : ι → E) (n : ι) :
gramSchmidt 𝕜 f n = f n - ∑ i ∈ Iio n, orthogonalProjection (𝕜 ∙ gramSchmidt 𝕜 f i) (f n) := by
rw [← sum_attach, attach_eq_univ, gramSchmidt]
#align gram_schmidt_def gramSchmidt_def
theorem gramSchmidt_def' (f : ι → E) (n : ι) :
f n = gramSchmidt 𝕜 f n + ∑ i ∈ Iio n, orthogonalProjection (𝕜 ∙ gramSchmidt 𝕜 f i) (f n) := by
rw [gramSchmidt_def, sub_add_cancel]
#align gram_schmidt_def' gramSchmidt_def'
theorem gramSchmidt_def'' (f : ι → E) (n : ι) :
f n = gramSchmidt 𝕜 f n + ∑ i ∈ Iio n,
(⟪gramSchmidt 𝕜 f i, f n⟫ / (‖gramSchmidt 𝕜 f i‖ : 𝕜) ^ 2) • gramSchmidt 𝕜 f i := by
convert gramSchmidt_def' 𝕜 f n
rw [orthogonalProjection_singleton, RCLike.ofReal_pow]
#align gram_schmidt_def'' gramSchmidt_def''
@[simp]
theorem gramSchmidt_zero {ι : Type*} [LinearOrder ι] [LocallyFiniteOrder ι] [OrderBot ι]
[IsWellOrder ι (· < ·)] (f : ι → E) : gramSchmidt 𝕜 f ⊥ = f ⊥ := by
rw [gramSchmidt_def, Iio_eq_Ico, Finset.Ico_self, Finset.sum_empty, sub_zero]
#align gram_schmidt_zero gramSchmidt_zero
theorem gramSchmidt_orthogonal (f : ι → E) {a b : ι} (h₀ : a ≠ b) :
⟪gramSchmidt 𝕜 f a, gramSchmidt 𝕜 f b⟫ = 0 := by
suffices ∀ a b : ι, a < b → ⟪gramSchmidt 𝕜 f a, gramSchmidt 𝕜 f b⟫ = 0 by
cases' h₀.lt_or_lt with ha hb
· exact this _ _ ha
· rw [inner_eq_zero_symm]
exact this _ _ hb
clear h₀ a b
intro a b h₀
revert a
apply wellFounded_lt.induction b
intro b ih a h₀
simp only [gramSchmidt_def 𝕜 f b, inner_sub_right, inner_sum, orthogonalProjection_singleton,
inner_smul_right]
rw [Finset.sum_eq_single_of_mem a (Finset.mem_Iio.mpr h₀)]
· by_cases h : gramSchmidt 𝕜 f a = 0
· simp only [h, inner_zero_left, zero_div, zero_mul, sub_zero]
· rw [RCLike.ofReal_pow, ← inner_self_eq_norm_sq_to_K, div_mul_cancel₀, sub_self]
rwa [inner_self_ne_zero]
intro i hi hia
simp only [mul_eq_zero, div_eq_zero_iff, inner_self_eq_zero]
right
cases' hia.lt_or_lt with hia₁ hia₂
· rw [inner_eq_zero_symm]
exact ih a h₀ i hia₁
· exact ih i (mem_Iio.1 hi) a hia₂
#align gram_schmidt_orthogonal gramSchmidt_orthogonal
theorem gramSchmidt_pairwise_orthogonal (f : ι → E) :
Pairwise fun a b => ⟪gramSchmidt 𝕜 f a, gramSchmidt 𝕜 f b⟫ = 0 := fun _ _ =>
gramSchmidt_orthogonal 𝕜 f
#align gram_schmidt_pairwise_orthogonal gramSchmidt_pairwise_orthogonal
theorem gramSchmidt_inv_triangular (v : ι → E) {i j : ι} (hij : i < j) :
⟪gramSchmidt 𝕜 v j, v i⟫ = 0 := by
rw [gramSchmidt_def'' 𝕜 v]
simp only [inner_add_right, inner_sum, inner_smul_right]
set b : ι → E := gramSchmidt 𝕜 v
convert zero_add (0 : 𝕜)
· exact gramSchmidt_orthogonal 𝕜 v hij.ne'
apply Finset.sum_eq_zero
rintro k hki'
have hki : k < i := by simpa using hki'
have : ⟪b j, b k⟫ = 0 := gramSchmidt_orthogonal 𝕜 v (hki.trans hij).ne'
simp [this]
#align gram_schmidt_inv_triangular gramSchmidt_inv_triangular
open Submodule Set Order
theorem mem_span_gramSchmidt (f : ι → E) {i j : ι} (hij : i ≤ j) :
f i ∈ span 𝕜 (gramSchmidt 𝕜 f '' Set.Iic j) := by
rw [gramSchmidt_def' 𝕜 f i]
simp_rw [orthogonalProjection_singleton]
exact Submodule.add_mem _ (subset_span <| mem_image_of_mem _ hij)
(Submodule.sum_mem _ fun k hk => smul_mem (span 𝕜 (gramSchmidt 𝕜 f '' Set.Iic j)) _ <|
subset_span <| mem_image_of_mem (gramSchmidt 𝕜 f) <| (Finset.mem_Iio.1 hk).le.trans hij)
#align mem_span_gram_schmidt mem_span_gramSchmidt
| Mathlib/Analysis/InnerProductSpace/GramSchmidtOrtho.lean | 142 | 152 | theorem gramSchmidt_mem_span (f : ι → E) :
∀ {j i}, i ≤ j → gramSchmidt 𝕜 f i ∈ span 𝕜 (f '' Set.Iic j) := by |
intro j i hij
rw [gramSchmidt_def 𝕜 f i]
simp_rw [orthogonalProjection_singleton]
refine Submodule.sub_mem _ (subset_span (mem_image_of_mem _ hij))
(Submodule.sum_mem _ fun k hk => ?_)
let hkj : k < j := (Finset.mem_Iio.1 hk).trans_le hij
exact smul_mem _ _
(span_mono (image_subset f <| Iic_subset_Iic.2 hkj.le) <| gramSchmidt_mem_span _ le_rfl)
termination_by j => j
|
import Mathlib.Algebra.BigOperators.Group.Finset
import Mathlib.Data.Finsupp.Defs
import Mathlib.Data.Finset.Pairwise
#align_import data.finsupp.big_operators from "leanprover-community/mathlib"@"59694bd07f0a39c5beccba34bd9f413a160782bf"
variable {ι M : Type*} [DecidableEq ι]
theorem List.support_sum_subset [AddMonoid M] (l : List (ι →₀ M)) :
l.sum.support ⊆ l.foldr (Finsupp.support · ⊔ ·) ∅ := by
induction' l with hd tl IH
· simp
· simp only [List.sum_cons, Finset.union_comm]
refine Finsupp.support_add.trans (Finset.union_subset_union ?_ IH)
rfl
#align list.support_sum_subset List.support_sum_subset
theorem Multiset.support_sum_subset [AddCommMonoid M] (s : Multiset (ι →₀ M)) :
s.sum.support ⊆ (s.map Finsupp.support).sup := by
induction s using Quot.inductionOn
simpa only [Multiset.quot_mk_to_coe'', Multiset.sum_coe, Multiset.map_coe, Multiset.sup_coe,
List.foldr_map] using List.support_sum_subset _
#align multiset.support_sum_subset Multiset.support_sum_subset
theorem Finset.support_sum_subset [AddCommMonoid M] (s : Finset (ι →₀ M)) :
(s.sum id).support ⊆ Finset.sup s Finsupp.support := by
classical convert Multiset.support_sum_subset s.1; simp
#align finset.support_sum_subset Finset.support_sum_subset
theorem List.mem_foldr_sup_support_iff [Zero M] {l : List (ι →₀ M)} {x : ι} :
x ∈ l.foldr (Finsupp.support · ⊔ ·) ∅ ↔ ∃ f ∈ l, x ∈ f.support := by
simp only [Finset.sup_eq_union, List.foldr_map, Finsupp.mem_support_iff, exists_prop]
induction' l with hd tl IH
· simp
· simp only [foldr, Function.comp_apply, Finset.mem_union, Finsupp.mem_support_iff, ne_eq, IH,
find?, mem_cons, exists_eq_or_imp]
#align list.mem_foldr_sup_support_iff List.mem_foldr_sup_support_iff
theorem Multiset.mem_sup_map_support_iff [Zero M] {s : Multiset (ι →₀ M)} {x : ι} :
x ∈ (s.map Finsupp.support).sup ↔ ∃ f ∈ s, x ∈ f.support :=
Quot.inductionOn s fun _ ↦ by
simpa only [Multiset.quot_mk_to_coe'', Multiset.map_coe, Multiset.sup_coe, List.foldr_map]
using List.mem_foldr_sup_support_iff
#align multiset.mem_sup_map_support_iff Multiset.mem_sup_map_support_iff
theorem Finset.mem_sup_support_iff [Zero M] {s : Finset (ι →₀ M)} {x : ι} :
x ∈ s.sup Finsupp.support ↔ ∃ f ∈ s, x ∈ f.support :=
Multiset.mem_sup_map_support_iff
#align finset.mem_sup_support_iff Finset.mem_sup_support_iff
theorem List.support_sum_eq [AddMonoid M] (l : List (ι →₀ M))
(hl : l.Pairwise (_root_.Disjoint on Finsupp.support)) :
l.sum.support = l.foldr (Finsupp.support · ⊔ ·) ∅ := by
induction' l with hd tl IH
· simp
· simp only [List.pairwise_cons] at hl
simp only [List.sum_cons, List.foldr_cons, Function.comp_apply]
rw [Finsupp.support_add_eq, IH hl.right, Finset.sup_eq_union]
suffices _root_.Disjoint hd.support (tl.foldr (fun x y ↦ (Finsupp.support x ⊔ y)) ∅) by
exact Finset.disjoint_of_subset_right (List.support_sum_subset _) this
rw [← List.foldr_map, ← Finset.bot_eq_empty, List.foldr_sup_eq_sup_toFinset,
Finset.disjoint_sup_right]
intro f hf
simp only [List.mem_toFinset, List.mem_map] at hf
obtain ⟨f, hf, rfl⟩ := hf
exact hl.left _ hf
#align list.support_sum_eq List.support_sum_eq
theorem Multiset.support_sum_eq [AddCommMonoid M] (s : Multiset (ι →₀ M))
(hs : s.Pairwise (_root_.Disjoint on Finsupp.support)) :
s.sum.support = (s.map Finsupp.support).sup := by
induction' s using Quot.inductionOn with a
obtain ⟨l, hl, hd⟩ := hs
suffices a.Pairwise (_root_.Disjoint on Finsupp.support) by
convert List.support_sum_eq a this
· simp only [Multiset.quot_mk_to_coe'', Multiset.sum_coe]
· dsimp only [Function.comp_def]
simp only [quot_mk_to_coe'', map_coe, sup_coe, ge_iff_le, Finset.le_eq_subset,
Finset.sup_eq_union, Finset.bot_eq_empty, List.foldr_map]
simp only [Multiset.quot_mk_to_coe'', Multiset.map_coe, Multiset.coe_eq_coe] at hl
exact hl.symm.pairwise hd fun h ↦ _root_.Disjoint.symm h
#align multiset.support_sum_eq Multiset.support_sum_eq
| Mathlib/Data/Finsupp/BigOperators.lean | 114 | 128 | theorem Finset.support_sum_eq [AddCommMonoid M] (s : Finset (ι →₀ M))
(hs : (s : Set (ι →₀ M)).PairwiseDisjoint Finsupp.support) :
(s.sum id).support = Finset.sup s Finsupp.support := by |
classical
suffices s.1.Pairwise (_root_.Disjoint on Finsupp.support) by
convert Multiset.support_sum_eq s.1 this
exact (Finset.sum_val _).symm
obtain ⟨l, hl, hn⟩ : ∃ l : List (ι →₀ M), l.toFinset = s ∧ l.Nodup := by
refine ⟨s.toList, ?_, Finset.nodup_toList _⟩
simp
subst hl
rwa [List.toFinset_val, List.dedup_eq_self.mpr hn, Multiset.pairwise_coe_iff_pairwise, ←
List.pairwiseDisjoint_iff_coe_toFinset_pairwise_disjoint hn]
intro x y hxy
exact symmetric_disjoint hxy
|
import Mathlib.Analysis.LocallyConvex.BalancedCoreHull
import Mathlib.Analysis.LocallyConvex.WithSeminorms
import Mathlib.Analysis.Convex.Gauge
#align_import analysis.locally_convex.abs_convex from "leanprover-community/mathlib"@"f2ce6086713c78a7f880485f7917ea547a215982"
open NormedField Set
open NNReal Pointwise Topology
variable {𝕜 E F G ι : Type*}
section NontriviallyNormedField
variable (𝕜 E) {s : Set E}
variable [NontriviallyNormedField 𝕜] [AddCommGroup E] [Module 𝕜 E]
variable [Module ℝ E] [SMulCommClass ℝ 𝕜 E]
variable [TopologicalSpace E] [LocallyConvexSpace ℝ E] [ContinuousSMul 𝕜 E]
| Mathlib/Analysis/LocallyConvex/AbsConvex.lean | 52 | 60 | theorem nhds_basis_abs_convex :
(𝓝 (0 : E)).HasBasis (fun s : Set E => s ∈ 𝓝 (0 : E) ∧ Balanced 𝕜 s ∧ Convex ℝ s) id := by |
refine
(LocallyConvexSpace.convex_basis_zero ℝ E).to_hasBasis (fun s hs => ?_) fun s hs =>
⟨s, ⟨hs.1, hs.2.2⟩, rfl.subset⟩
refine ⟨convexHull ℝ (balancedCore 𝕜 s), ?_, convexHull_min (balancedCore_subset s) hs.2⟩
refine ⟨Filter.mem_of_superset (balancedCore_mem_nhds_zero hs.1) (subset_convexHull ℝ _), ?_⟩
refine ⟨(balancedCore_balanced s).convexHull, ?_⟩
exact convex_convexHull ℝ (balancedCore 𝕜 s)
|
import Mathlib.RingTheory.Nilpotent.Basic
import Mathlib.RingTheory.UniqueFactorizationDomain
#align_import algebra.squarefree from "leanprover-community/mathlib"@"00d163e35035c3577c1c79fa53b68de17781ffc1"
variable {R : Type*}
def Squarefree [Monoid R] (r : R) : Prop :=
∀ x : R, x * x ∣ r → IsUnit x
#align squarefree Squarefree
theorem IsRelPrime.of_squarefree_mul [CommMonoid R] {m n : R} (h : Squarefree (m * n)) :
IsRelPrime m n := fun c hca hcb ↦ h c (mul_dvd_mul hca hcb)
@[simp]
theorem IsUnit.squarefree [CommMonoid R] {x : R} (h : IsUnit x) : Squarefree x := fun _ hdvd =>
isUnit_of_mul_isUnit_left (isUnit_of_dvd_unit hdvd h)
#align is_unit.squarefree IsUnit.squarefree
-- @[simp] -- Porting note (#10618): simp can prove this
theorem squarefree_one [CommMonoid R] : Squarefree (1 : R) :=
isUnit_one.squarefree
#align squarefree_one squarefree_one
@[simp]
theorem not_squarefree_zero [MonoidWithZero R] [Nontrivial R] : ¬Squarefree (0 : R) := by
erw [not_forall]
exact ⟨0, by simp⟩
#align not_squarefree_zero not_squarefree_zero
theorem Squarefree.ne_zero [MonoidWithZero R] [Nontrivial R] {m : R} (hm : Squarefree (m : R)) :
m ≠ 0 := by
rintro rfl
exact not_squarefree_zero hm
#align squarefree.ne_zero Squarefree.ne_zero
@[simp]
theorem Irreducible.squarefree [CommMonoid R] {x : R} (h : Irreducible x) : Squarefree x := by
rintro y ⟨z, hz⟩
rw [mul_assoc] at hz
rcases h.isUnit_or_isUnit hz with (hu | hu)
· exact hu
· apply isUnit_of_mul_isUnit_left hu
#align irreducible.squarefree Irreducible.squarefree
@[simp]
theorem Prime.squarefree [CancelCommMonoidWithZero R] {x : R} (h : Prime x) : Squarefree x :=
h.irreducible.squarefree
#align prime.squarefree Prime.squarefree
theorem Squarefree.of_mul_left [CommMonoid R] {m n : R} (hmn : Squarefree (m * n)) : Squarefree m :=
fun p hp => hmn p (dvd_mul_of_dvd_left hp n)
#align squarefree.of_mul_left Squarefree.of_mul_left
theorem Squarefree.of_mul_right [CommMonoid R] {m n : R} (hmn : Squarefree (m * n)) :
Squarefree n := fun p hp => hmn p (dvd_mul_of_dvd_right hp m)
#align squarefree.of_mul_right Squarefree.of_mul_right
theorem Squarefree.squarefree_of_dvd [CommMonoid R] {x y : R} (hdvd : x ∣ y) (hsq : Squarefree y) :
Squarefree x := fun _ h => hsq _ (h.trans hdvd)
#align squarefree.squarefree_of_dvd Squarefree.squarefree_of_dvd
theorem Squarefree.eq_zero_or_one_of_pow_of_not_isUnit [CommMonoid R] {x : R} {n : ℕ}
(h : Squarefree (x ^ n)) (h' : ¬ IsUnit x) :
n = 0 ∨ n = 1 := by
contrapose! h'
replace h' : 2 ≤ n := by omega
have : x * x ∣ x ^ n := by rw [← sq]; exact pow_dvd_pow x h'
exact h.squarefree_of_dvd this x (refl _)
namespace multiplicity
section Irreducible
variable [CommMonoidWithZero R] [WfDvdMonoid R]
| Mathlib/Algebra/Squarefree/Basic.lean | 147 | 152 | theorem squarefree_iff_no_irreducibles {x : R} (hx₀ : x ≠ 0) :
Squarefree x ↔ ∀ p, Irreducible p → ¬ (p * p ∣ x) := by |
refine ⟨fun h p hp hp' ↦ hp.not_unit (h p hp'), fun h d hd ↦ by_contra fun hdu ↦ ?_⟩
have hd₀ : d ≠ 0 := ne_zero_of_dvd_ne_zero (ne_zero_of_dvd_ne_zero hx₀ hd) (dvd_mul_left d d)
obtain ⟨p, irr, dvd⟩ := WfDvdMonoid.exists_irreducible_factor hdu hd₀
exact h p irr ((mul_dvd_mul dvd dvd).trans hd)
|
import Mathlib.CategoryTheory.ConcreteCategory.Basic
import Mathlib.CategoryTheory.FullSubcategory
import Mathlib.CategoryTheory.Skeletal
import Mathlib.Data.Fintype.Card
#align_import category_theory.Fintype from "leanprover-community/mathlib"@"c3019c79074b0619edb4b27553a91b2e82242395"
open scoped Classical
open CategoryTheory
def FintypeCat :=
Bundled Fintype
set_option linter.uppercaseLean3 false in
#align Fintype FintypeCat
namespace FintypeCat
instance : CoeSort FintypeCat Type* :=
Bundled.coeSort
def of (X : Type*) [Fintype X] : FintypeCat :=
Bundled.of X
set_option linter.uppercaseLean3 false in
#align Fintype.of FintypeCat.of
instance : Inhabited FintypeCat :=
⟨of PEmpty⟩
instance {X : FintypeCat} : Fintype X :=
X.2
instance : Category FintypeCat :=
InducedCategory.category Bundled.α
@[simps!]
def incl : FintypeCat ⥤ Type* :=
inducedFunctor _
set_option linter.uppercaseLean3 false in
#align Fintype.incl FintypeCat.incl
instance : incl.Full := InducedCategory.full _
instance : incl.Faithful := InducedCategory.faithful _
instance concreteCategoryFintype : ConcreteCategory FintypeCat :=
⟨incl⟩
set_option linter.uppercaseLean3 false in
#align Fintype.concrete_category_Fintype FintypeCat.concreteCategoryFintype
instance : (forget FintypeCat).Full := inferInstanceAs <| FintypeCat.incl.Full
@[simp]
theorem id_apply (X : FintypeCat) (x : X) : (𝟙 X : X → X) x = x :=
rfl
set_option linter.uppercaseLean3 false in
#align Fintype.id_apply FintypeCat.id_apply
@[simp]
theorem comp_apply {X Y Z : FintypeCat} (f : X ⟶ Y) (g : Y ⟶ Z) (x : X) : (f ≫ g) x = g (f x) :=
rfl
set_option linter.uppercaseLean3 false in
#align Fintype.comp_apply FintypeCat.comp_apply
@[simp]
lemma hom_inv_id_apply {X Y : FintypeCat} (f : X ≅ Y) (x : X) : f.inv (f.hom x) = x :=
congr_fun f.hom_inv_id x
@[simp]
lemma inv_hom_id_apply {X Y : FintypeCat} (f : X ≅ Y) (y : Y) : f.hom (f.inv y) = y :=
congr_fun f.inv_hom_id y
-- Porting note (#10688): added to ease automation
@[ext]
lemma hom_ext {X Y : FintypeCat} (f g : X ⟶ Y) (h : ∀ x, f x = g x) : f = g := by
funext
apply h
-- See `equivEquivIso` in the root namespace for the analogue in `Type`.
@[simps]
def equivEquivIso {A B : FintypeCat} : A ≃ B ≃ (A ≅ B) where
toFun e :=
{ hom := e
inv := e.symm }
invFun i :=
{ toFun := i.hom
invFun := i.inv
left_inv := congr_fun i.hom_inv_id
right_inv := congr_fun i.inv_hom_id }
left_inv := by aesop_cat
right_inv := by aesop_cat
set_option linter.uppercaseLean3 false in
#align Fintype.equiv_equiv_iso FintypeCat.equivEquivIso
universe u
def Skeleton : Type u :=
ULift ℕ
set_option linter.uppercaseLean3 false in
#align Fintype.skeleton FintypeCat.Skeleton
namespace Skeleton
def mk : ℕ → Skeleton :=
ULift.up
set_option linter.uppercaseLean3 false in
#align Fintype.skeleton.mk FintypeCat.Skeleton.mk
instance : Inhabited Skeleton :=
⟨mk 0⟩
def len : Skeleton → ℕ :=
ULift.down
set_option linter.uppercaseLean3 false in
#align Fintype.skeleton.len FintypeCat.Skeleton.len
@[ext]
theorem ext (X Y : Skeleton) : X.len = Y.len → X = Y :=
ULift.ext _ _
set_option linter.uppercaseLean3 false in
#align Fintype.skeleton.ext FintypeCat.Skeleton.ext
instance : SmallCategory Skeleton.{u} where
Hom X Y := ULift.{u} (Fin X.len) → ULift.{u} (Fin Y.len)
id _ := id
comp f g := g ∘ f
theorem is_skeletal : Skeletal Skeleton.{u} := fun X Y ⟨h⟩ =>
ext _ _ <|
Fin.equiv_iff_eq.mp <|
Nonempty.intro <|
{ toFun := fun x => (h.hom ⟨x⟩).down
invFun := fun x => (h.inv ⟨x⟩).down
left_inv := by
intro a
change ULift.down _ = _
rw [ULift.up_down]
change ((h.hom ≫ h.inv) _).down = _
simp
rfl
right_inv := by
intro a
change ULift.down _ = _
rw [ULift.up_down]
change ((h.inv ≫ h.hom) _).down = _
simp
rfl }
set_option linter.uppercaseLean3 false in
#align Fintype.skeleton.is_skeletal FintypeCat.Skeleton.is_skeletal
def incl : Skeleton.{u} ⥤ FintypeCat.{u} where
obj X := FintypeCat.of (ULift (Fin X.len))
map f := f
set_option linter.uppercaseLean3 false in
#align Fintype.skeleton.incl FintypeCat.Skeleton.incl
instance : incl.Full where map_surjective f := ⟨f, rfl⟩
instance : incl.Faithful where
instance : incl.EssSurj :=
Functor.EssSurj.mk fun X =>
let F := Fintype.equivFin X
⟨mk (Fintype.card X),
Nonempty.intro
{ hom := F.symm ∘ ULift.down
inv := ULift.up ∘ F }⟩
noncomputable instance : incl.IsEquivalence where
noncomputable def equivalence : Skeleton ≌ FintypeCat :=
incl.asEquivalence
set_option linter.uppercaseLean3 false in
#align Fintype.skeleton.equivalence FintypeCat.Skeleton.equivalence
@[simp]
| Mathlib/CategoryTheory/FintypeCat.lean | 211 | 213 | theorem incl_mk_nat_card (n : ℕ) : Fintype.card (incl.obj (mk n)) = n := by |
convert Finset.card_fin n
apply Fintype.ofEquiv_card
|
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 Preimage
variable {f : α → β} {g : β → γ}
@[simp]
theorem preimage_empty : f ⁻¹' ∅ = ∅ :=
rfl
#align set.preimage_empty Set.preimage_empty
theorem preimage_congr {f g : α → β} {s : Set β} (h : ∀ x : α, f x = g x) : f ⁻¹' s = g ⁻¹' s := by
congr with x
simp [h]
#align set.preimage_congr Set.preimage_congr
@[gcongr]
theorem preimage_mono {s t : Set β} (h : s ⊆ t) : f ⁻¹' s ⊆ f ⁻¹' t := fun _ hx => h hx
#align set.preimage_mono Set.preimage_mono
@[simp, mfld_simps]
theorem preimage_univ : f ⁻¹' univ = univ :=
rfl
#align set.preimage_univ Set.preimage_univ
theorem subset_preimage_univ {s : Set α} : s ⊆ f ⁻¹' univ :=
subset_univ _
#align set.subset_preimage_univ Set.subset_preimage_univ
@[simp, mfld_simps]
theorem preimage_inter {s t : Set β} : f ⁻¹' (s ∩ t) = f ⁻¹' s ∩ f ⁻¹' t :=
rfl
#align set.preimage_inter Set.preimage_inter
@[simp]
theorem preimage_union {s t : Set β} : f ⁻¹' (s ∪ t) = f ⁻¹' s ∪ f ⁻¹' t :=
rfl
#align set.preimage_union Set.preimage_union
@[simp]
theorem preimage_compl {s : Set β} : f ⁻¹' sᶜ = (f ⁻¹' s)ᶜ :=
rfl
#align set.preimage_compl Set.preimage_compl
@[simp]
theorem preimage_diff (f : α → β) (s t : Set β) : f ⁻¹' (s \ t) = f ⁻¹' s \ f ⁻¹' t :=
rfl
#align set.preimage_diff Set.preimage_diff
open scoped symmDiff in
@[simp]
lemma preimage_symmDiff {f : α → β} (s t : Set β) : f ⁻¹' (s ∆ t) = (f ⁻¹' s) ∆ (f ⁻¹' t) :=
rfl
#align set.preimage_symm_diff Set.preimage_symmDiff
@[simp]
theorem preimage_ite (f : α → β) (s t₁ t₂ : Set β) :
f ⁻¹' s.ite t₁ t₂ = (f ⁻¹' s).ite (f ⁻¹' t₁) (f ⁻¹' t₂) :=
rfl
#align set.preimage_ite Set.preimage_ite
@[simp]
theorem preimage_setOf_eq {p : α → Prop} {f : β → α} : f ⁻¹' { a | p a } = { a | p (f a) } :=
rfl
#align set.preimage_set_of_eq Set.preimage_setOf_eq
@[simp]
theorem preimage_id_eq : preimage (id : α → α) = id :=
rfl
#align set.preimage_id_eq Set.preimage_id_eq
@[mfld_simps]
theorem preimage_id {s : Set α} : id ⁻¹' s = s :=
rfl
#align set.preimage_id Set.preimage_id
@[simp, mfld_simps]
theorem preimage_id' {s : Set α} : (fun x => x) ⁻¹' s = s :=
rfl
#align set.preimage_id' Set.preimage_id'
@[simp]
theorem preimage_const_of_mem {b : β} {s : Set β} (h : b ∈ s) : (fun _ : α => b) ⁻¹' s = univ :=
eq_univ_of_forall fun _ => h
#align set.preimage_const_of_mem Set.preimage_const_of_mem
@[simp]
theorem preimage_const_of_not_mem {b : β} {s : Set β} (h : b ∉ s) : (fun _ : α => b) ⁻¹' s = ∅ :=
eq_empty_of_subset_empty fun _ hx => h hx
#align set.preimage_const_of_not_mem Set.preimage_const_of_not_mem
theorem preimage_const (b : β) (s : Set β) [Decidable (b ∈ s)] :
(fun _ : α => b) ⁻¹' s = if b ∈ s then univ else ∅ := by
split_ifs with hb
exacts [preimage_const_of_mem hb, preimage_const_of_not_mem hb]
#align set.preimage_const Set.preimage_const
lemma exists_eq_const_of_preimage_singleton [Nonempty β] {f : α → β}
(hf : ∀ b : β, f ⁻¹' {b} = ∅ ∨ f ⁻¹' {b} = univ) : ∃ b, f = const α b := by
rcases em (∃ b, f ⁻¹' {b} = univ) with ⟨b, hb⟩ | hf'
· exact ⟨b, funext fun x ↦ eq_univ_iff_forall.1 hb x⟩
· have : ∀ x b, f x ≠ b := fun x b ↦
eq_empty_iff_forall_not_mem.1 ((hf b).resolve_right fun h ↦ hf' ⟨b, h⟩) x
exact ⟨Classical.arbitrary β, funext fun x ↦ absurd rfl (this x _)⟩
theorem preimage_comp {s : Set γ} : g ∘ f ⁻¹' s = f ⁻¹' (g ⁻¹' s) :=
rfl
#align set.preimage_comp Set.preimage_comp
theorem preimage_comp_eq : preimage (g ∘ f) = preimage f ∘ preimage g :=
rfl
#align set.preimage_comp_eq Set.preimage_comp_eq
| Mathlib/Data/Set/Image.lean | 157 | 159 | theorem preimage_iterate_eq {f : α → α} {n : ℕ} : Set.preimage f^[n] = (Set.preimage f)^[n] := by |
induction' n with n ih; · simp
rw [iterate_succ, iterate_succ', preimage_comp_eq, ih]
|
import Mathlib.Algebra.Associated
import Mathlib.Algebra.BigOperators.Group.Finset
import Mathlib.Algebra.Order.Group.Abs
import Mathlib.Algebra.Ring.Divisibility.Basic
#align_import ring_theory.prime from "leanprover-community/mathlib"@"008205aa645b3f194c1da47025c5f110c8406eab"
section CommRing
variable {α : Type*} [CommRing α]
| Mathlib/RingTheory/Prime.lean | 65 | 67 | theorem Prime.neg {p : α} (hp : Prime p) : Prime (-p) := by |
obtain ⟨h1, h2, h3⟩ := hp
exact ⟨neg_ne_zero.mpr h1, by rwa [IsUnit.neg_iff], by simpa [neg_dvd] using h3⟩
|
import Mathlib.LinearAlgebra.Matrix.Charpoly.Coeff
import Mathlib.LinearAlgebra.Matrix.ToLin
#align_import linear_algebra.matrix.charpoly.linear_map from "leanprover-community/mathlib"@"62c0a4ef1441edb463095ea02a06e87f3dfe135c"
variable {ι : Type*} [Fintype ι]
variable {M : Type*} [AddCommGroup M] (R : Type*) [CommRing R] [Module R M] (I : Ideal R)
variable (b : ι → M) (hb : Submodule.span R (Set.range b) = ⊤)
open Polynomial Matrix
def PiToModule.fromMatrix [DecidableEq ι] : Matrix ι ι R →ₗ[R] (ι → R) →ₗ[R] M :=
(LinearMap.llcomp R _ _ _ (Fintype.total R R b)).comp algEquivMatrix'.symm.toLinearMap
#align pi_to_module.from_matrix PiToModule.fromMatrix
theorem PiToModule.fromMatrix_apply [DecidableEq ι] (A : Matrix ι ι R) (w : ι → R) :
PiToModule.fromMatrix R b A w = Fintype.total R R b (A *ᵥ w) :=
rfl
#align pi_to_module.from_matrix_apply PiToModule.fromMatrix_apply
theorem PiToModule.fromMatrix_apply_single_one [DecidableEq ι] (A : Matrix ι ι R) (j : ι) :
PiToModule.fromMatrix R b A (Pi.single j 1) = ∑ i : ι, A i j • b i := by
rw [PiToModule.fromMatrix_apply, Fintype.total_apply, Matrix.mulVec_single]
simp_rw [mul_one]
#align pi_to_module.from_matrix_apply_single_one PiToModule.fromMatrix_apply_single_one
def PiToModule.fromEnd : Module.End R M →ₗ[R] (ι → R) →ₗ[R] M :=
LinearMap.lcomp _ _ (Fintype.total R R b)
#align pi_to_module.from_End PiToModule.fromEnd
theorem PiToModule.fromEnd_apply (f : Module.End R M) (w : ι → R) :
PiToModule.fromEnd R b f w = f (Fintype.total R R b w) :=
rfl
#align pi_to_module.from_End_apply PiToModule.fromEnd_apply
| Mathlib/LinearAlgebra/Matrix/Charpoly/LinearMap.lean | 60 | 65 | theorem PiToModule.fromEnd_apply_single_one [DecidableEq ι] (f : Module.End R M) (i : ι) :
PiToModule.fromEnd R b f (Pi.single i 1) = f (b i) := by |
rw [PiToModule.fromEnd_apply]
congr
convert Fintype.total_apply_single (S := R) R b i (1 : R)
rw [one_smul]
|
import Mathlib.Algebra.Order.Ring.Abs
import Mathlib.Data.Nat.ModEq
import Mathlib.Order.Filter.AtTopBot
#align_import order.filter.modeq from "leanprover-community/mathlib"@"f7fc89d5d5ff1db2d1242c7bb0e9062ce47ef47c"
open Filter
namespace Nat
theorem frequently_modEq {n : ℕ} (h : n ≠ 0) (d : ℕ) : ∃ᶠ m in atTop, m ≡ d [MOD n] :=
((tendsto_add_atTop_nat d).comp (tendsto_id.nsmul_atTop h.bot_lt)).frequently <|
frequently_of_forall fun m => by simp [Nat.modEq_iff_dvd, ← sub_sub]
#align nat.frequently_modeq Nat.frequently_modEq
| Mathlib/Order/Filter/ModEq.lean | 29 | 30 | theorem frequently_mod_eq {d n : ℕ} (h : d < n) : ∃ᶠ m in atTop, m % n = d := by |
simpa only [Nat.ModEq, mod_eq_of_lt h] using frequently_modEq h.ne_bot d
|
import Mathlib.Combinatorics.Quiver.Cast
import Mathlib.Combinatorics.Quiver.Symmetric
import Mathlib.Data.Sigma.Basic
import Mathlib.Logic.Equiv.Basic
import Mathlib.Tactic.Common
#align_import combinatorics.quiver.covering from "leanprover-community/mathlib"@"188a411e916e1119e502dbe35b8b475716362401"
open Function Quiver
universe u v w
variable {U : Type _} [Quiver.{u + 1} U] {V : Type _} [Quiver.{v + 1} V] (φ : U ⥤q V) {W : Type _}
[Quiver.{w + 1} W] (ψ : V ⥤q W)
abbrev Quiver.Star (u : U) :=
Σ v : U, u ⟶ v
#align quiver.star Quiver.Star
protected abbrev Quiver.Star.mk {u v : U} (f : u ⟶ v) : Quiver.Star u :=
⟨_, f⟩
#align quiver.star.mk Quiver.Star.mk
abbrev Quiver.Costar (v : U) :=
Σ u : U, u ⟶ v
#align quiver.costar Quiver.Costar
protected abbrev Quiver.Costar.mk {u v : U} (f : u ⟶ v) : Quiver.Costar v :=
⟨_, f⟩
#align quiver.costar.mk Quiver.Costar.mk
@[simps]
def Prefunctor.star (u : U) : Quiver.Star u → Quiver.Star (φ.obj u) := fun F =>
Quiver.Star.mk (φ.map F.2)
#align prefunctor.star Prefunctor.star
@[simps]
def Prefunctor.costar (u : U) : Quiver.Costar u → Quiver.Costar (φ.obj u) := fun F =>
Quiver.Costar.mk (φ.map F.2)
#align prefunctor.costar Prefunctor.costar
@[simp]
theorem Prefunctor.star_apply {u v : U} (e : u ⟶ v) :
φ.star u (Quiver.Star.mk e) = Quiver.Star.mk (φ.map e) :=
rfl
#align prefunctor.star_apply Prefunctor.star_apply
@[simp]
theorem Prefunctor.costar_apply {u v : U} (e : u ⟶ v) :
φ.costar v (Quiver.Costar.mk e) = Quiver.Costar.mk (φ.map e) :=
rfl
#align prefunctor.costar_apply Prefunctor.costar_apply
theorem Prefunctor.star_comp (u : U) : (φ ⋙q ψ).star u = ψ.star (φ.obj u) ∘ φ.star u :=
rfl
#align prefunctor.star_comp Prefunctor.star_comp
theorem Prefunctor.costar_comp (u : U) : (φ ⋙q ψ).costar u = ψ.costar (φ.obj u) ∘ φ.costar u :=
rfl
#align prefunctor.costar_comp Prefunctor.costar_comp
protected structure Prefunctor.IsCovering : Prop where
star_bijective : ∀ u, Bijective (φ.star u)
costar_bijective : ∀ u, Bijective (φ.costar u)
#align prefunctor.is_covering Prefunctor.IsCovering
@[simp]
theorem Prefunctor.IsCovering.map_injective (hφ : φ.IsCovering) {u v : U} :
Injective fun f : u ⟶ v => φ.map f := by
rintro f g he
have : φ.star u (Quiver.Star.mk f) = φ.star u (Quiver.Star.mk g) := by simpa using he
simpa using (hφ.star_bijective u).left this
#align prefunctor.is_covering.map_injective Prefunctor.IsCovering.map_injective
theorem Prefunctor.IsCovering.comp (hφ : φ.IsCovering) (hψ : ψ.IsCovering) : (φ ⋙q ψ).IsCovering :=
⟨fun _ => (hψ.star_bijective _).comp (hφ.star_bijective _),
fun _ => (hψ.costar_bijective _).comp (hφ.costar_bijective _)⟩
#align prefunctor.is_covering.comp Prefunctor.IsCovering.comp
theorem Prefunctor.IsCovering.of_comp_right (hψ : ψ.IsCovering) (hφψ : (φ ⋙q ψ).IsCovering) :
φ.IsCovering :=
⟨fun _ => (Bijective.of_comp_iff' (hψ.star_bijective _) _).mp (hφψ.star_bijective _),
fun _ => (Bijective.of_comp_iff' (hψ.costar_bijective _) _).mp (hφψ.costar_bijective _)⟩
#align prefunctor.is_covering.of_comp_right Prefunctor.IsCovering.of_comp_right
theorem Prefunctor.IsCovering.of_comp_left (hφ : φ.IsCovering) (hφψ : (φ ⋙q ψ).IsCovering)
(φsur : Surjective φ.obj) : ψ.IsCovering := by
refine ⟨fun v => ?_, fun v => ?_⟩ <;> obtain ⟨u, rfl⟩ := φsur v
exacts [(Bijective.of_comp_iff _ (hφ.star_bijective u)).mp (hφψ.star_bijective u),
(Bijective.of_comp_iff _ (hφ.costar_bijective u)).mp (hφψ.costar_bijective u)]
#align prefunctor.is_covering.of_comp_left Prefunctor.IsCovering.of_comp_left
def Quiver.symmetrifyStar (u : U) :
Quiver.Star (Symmetrify.of.obj u) ≃ Sum (Quiver.Star u) (Quiver.Costar u) :=
Equiv.sigmaSumDistrib _ _
#align quiver.symmetrify_star Quiver.symmetrifyStar
def Quiver.symmetrifyCostar (u : U) :
Quiver.Costar (Symmetrify.of.obj u) ≃ Sum (Quiver.Costar u) (Quiver.Star u) :=
Equiv.sigmaSumDistrib _ _
#align quiver.symmetrify_costar Quiver.symmetrifyCostar
| Mathlib/Combinatorics/Quiver/Covering.lean | 153 | 163 | theorem Prefunctor.symmetrifyStar (u : U) :
φ.symmetrify.star u =
(Quiver.symmetrifyStar _).symm ∘ Sum.map (φ.star u) (φ.costar u) ∘
Quiver.symmetrifyStar u := by |
-- This used to be `rw`, but we need `erw` after leanprover/lean4#2644
erw [Equiv.eq_symm_comp]
ext ⟨v, f | g⟩ <;>
-- porting note (#10745): was `simp [Quiver.symmetrifyStar]`
simp only [Quiver.symmetrifyStar, Function.comp_apply] <;>
erw [Equiv.sigmaSumDistrib_apply, Equiv.sigmaSumDistrib_apply] <;>
simp
|
import Mathlib.Order.Interval.Set.UnorderedInterval
import Mathlib.Algebra.Order.Interval.Set.Monoid
import Mathlib.Data.Set.Pointwise.Basic
import Mathlib.Algebra.Order.Field.Basic
import Mathlib.Algebra.Order.Group.MinMax
#align_import data.set.pointwise.interval from "leanprover-community/mathlib"@"2196ab363eb097c008d4497125e0dde23fb36db2"
open Interval Pointwise
variable {α : Type*}
namespace Set
section ContravariantLT
variable [Mul α] [PartialOrder α]
variable [CovariantClass α α (· * ·) (· < ·)] [CovariantClass α α (Function.swap HMul.hMul) LT.lt]
@[to_additive Icc_add_Ico_subset]
theorem Icc_mul_Ico_subset' (a b c d : α) : Icc a b * Ico c d ⊆ Ico (a * c) (b * d) := by
haveI := covariantClass_le_of_lt
rintro x ⟨y, ⟨hya, hyb⟩, z, ⟨hzc, hzd⟩, rfl⟩
exact ⟨mul_le_mul' hya hzc, mul_lt_mul_of_le_of_lt hyb hzd⟩
@[to_additive Ico_add_Icc_subset]
theorem Ico_mul_Icc_subset' (a b c d : α) : Ico a b * Icc c d ⊆ Ico (a * c) (b * d) := by
haveI := covariantClass_le_of_lt
rintro x ⟨y, ⟨hya, hyb⟩, z, ⟨hzc, hzd⟩, rfl⟩
exact ⟨mul_le_mul' hya hzc, mul_lt_mul_of_lt_of_le hyb hzd⟩
@[to_additive Ioc_add_Ico_subset]
| Mathlib/Data/Set/Pointwise/Interval.lean | 80 | 83 | theorem Ioc_mul_Ico_subset' (a b c d : α) : Ioc a b * Ico c d ⊆ Ioo (a * c) (b * d) := by |
haveI := covariantClass_le_of_lt
rintro x ⟨y, ⟨hya, hyb⟩, z, ⟨hzc, hzd⟩, rfl⟩
exact ⟨mul_lt_mul_of_lt_of_le hya hzc, mul_lt_mul_of_le_of_lt hyb hzd⟩
|
import Mathlib.Geometry.Euclidean.Inversion.Basic
import Mathlib.Geometry.Euclidean.PerpBisector
open Metric Function AffineMap Set AffineSubspace
open scoped Topology
variable {V P : Type*} [NormedAddCommGroup V] [InnerProductSpace ℝ V] [MetricSpace P]
[NormedAddTorsor V P] {c x y : P} {R : ℝ}
namespace EuclideanGeometry
theorem inversion_mem_perpBisector_inversion_iff (hR : R ≠ 0) (hx : x ≠ c) (hy : y ≠ c) :
inversion c R x ∈ perpBisector c (inversion c R y) ↔ dist x y = dist y c := by
rw [mem_perpBisector_iff_dist_eq, dist_inversion_inversion hx hy, dist_inversion_center]
have hx' := dist_ne_zero.2 hx
have hy' := dist_ne_zero.2 hy
field_simp [mul_assoc, mul_comm, hx, hx.symm, eq_comm]
| Mathlib/Geometry/Euclidean/Inversion/ImageHyperplane.lean | 46 | 50 | theorem inversion_mem_perpBisector_inversion_iff' (hR : R ≠ 0) (hy : y ≠ c) :
inversion c R x ∈ perpBisector c (inversion c R y) ↔ dist x y = dist y c ∧ x ≠ c := by |
rcases eq_or_ne x c with rfl | hx
· simp [*]
· simp [inversion_mem_perpBisector_inversion_iff hR hx hy, hx]
|
import Mathlib.Control.Applicative
import Mathlib.Control.Traversable.Basic
import Mathlib.Data.List.Forall2
import Mathlib.Data.Set.Functor
#align_import control.traversable.instances from "leanprover-community/mathlib"@"18a5306c091183ac90884daa9373fa3b178e8607"
universe u v
section Option
open Functor
variable {F G : Type u → Type u}
variable [Applicative F] [Applicative G]
variable [LawfulApplicative F] [LawfulApplicative G]
theorem Option.id_traverse {α} (x : Option α) : Option.traverse (pure : α → Id α) x = x := by
cases x <;> rfl
#align option.id_traverse Option.id_traverse
theorem Option.comp_traverse {α β γ} (f : β → F γ) (g : α → G β) (x : Option α) :
Option.traverse (Comp.mk ∘ (f <$> ·) ∘ g) x =
Comp.mk (Option.traverse f <$> Option.traverse g x) := by
cases x <;> simp! [functor_norm] <;> rfl
#align option.comp_traverse Option.comp_traverse
| Mathlib/Control/Traversable/Instances.lean | 41 | 42 | theorem Option.traverse_eq_map_id {α β} (f : α → β) (x : Option α) :
Option.traverse ((pure : _ → Id _) ∘ f) x = (pure : _ → Id _) (f <$> x) := by | cases x <;> rfl
|
import Mathlib.NumberTheory.FLT.Basic
import Mathlib.NumberTheory.PythagoreanTriples
import Mathlib.RingTheory.Coprime.Lemmas
import Mathlib.Tactic.LinearCombination
#align_import number_theory.fermat4 from "leanprover-community/mathlib"@"10b4e499f43088dd3bb7b5796184ad5216648ab1"
noncomputable section
open scoped Classical
def Fermat42 (a b c : ℤ) : Prop :=
a ≠ 0 ∧ b ≠ 0 ∧ a ^ 4 + b ^ 4 = c ^ 2
#align fermat_42 Fermat42
namespace Fermat42
| Mathlib/NumberTheory/FLT/Four.lean | 32 | 35 | theorem comm {a b c : ℤ} : Fermat42 a b c ↔ Fermat42 b a c := by |
delta Fermat42
rw [add_comm]
tauto
|
import Mathlib.Algebra.Polynomial.Eval
import Mathlib.RingTheory.Ideal.Quotient
#align_import linear_algebra.smodeq from "leanprover-community/mathlib"@"146d3d1fa59c091fedaad8a4afa09d6802886d24"
open Submodule
open Polynomial
variable {R : Type*} [Ring R]
variable {A : Type*} [CommRing A]
variable {M : Type*} [AddCommGroup M] [Module R M] (U U₁ U₂ : Submodule R M)
variable {x x₁ x₂ y y₁ y₂ z z₁ z₂ : M}
variable {N : Type*} [AddCommGroup N] [Module R N] (V V₁ V₂ : Submodule R N)
set_option backward.isDefEq.lazyWhnfCore false in -- See https://github.com/leanprover-community/mathlib4/issues/12534
def SModEq (x y : M) : Prop :=
(Submodule.Quotient.mk x : M ⧸ U) = Submodule.Quotient.mk y
#align smodeq SModEq
notation:50 x " ≡ " y " [SMOD " N "]" => SModEq N x y
variable {U U₁ U₂}
set_option backward.isDefEq.lazyWhnfCore false in -- See https://github.com/leanprover-community/mathlib4/issues/12534
protected theorem SModEq.def :
x ≡ y [SMOD U] ↔ (Submodule.Quotient.mk x : M ⧸ U) = Submodule.Quotient.mk y :=
Iff.rfl
#align smodeq.def SModEq.def
namespace SModEq
theorem sub_mem : x ≡ y [SMOD U] ↔ x - y ∈ U := by rw [SModEq.def, Submodule.Quotient.eq]
#align smodeq.sub_mem SModEq.sub_mem
@[simp]
theorem top : x ≡ y [SMOD (⊤ : Submodule R M)] :=
(Submodule.Quotient.eq ⊤).2 mem_top
#align smodeq.top SModEq.top
@[simp]
theorem bot : x ≡ y [SMOD (⊥ : Submodule R M)] ↔ x = y := by
rw [SModEq.def, Submodule.Quotient.eq, mem_bot, sub_eq_zero]
#align smodeq.bot SModEq.bot
@[mono]
theorem mono (HU : U₁ ≤ U₂) (hxy : x ≡ y [SMOD U₁]) : x ≡ y [SMOD U₂] :=
(Submodule.Quotient.eq U₂).2 <| HU <| (Submodule.Quotient.eq U₁).1 hxy
#align smodeq.mono SModEq.mono
@[refl]
protected theorem refl (x : M) : x ≡ x [SMOD U] :=
@rfl _ _
#align smodeq.refl SModEq.refl
protected theorem rfl : x ≡ x [SMOD U] :=
SModEq.refl _
#align smodeq.rfl SModEq.rfl
instance : IsRefl _ (SModEq U) :=
⟨SModEq.refl⟩
@[symm]
nonrec theorem symm (hxy : x ≡ y [SMOD U]) : y ≡ x [SMOD U] :=
hxy.symm
#align smodeq.symm SModEq.symm
@[trans]
nonrec theorem trans (hxy : x ≡ y [SMOD U]) (hyz : y ≡ z [SMOD U]) : x ≡ z [SMOD U] :=
hxy.trans hyz
#align smodeq.trans SModEq.trans
instance instTrans : Trans (SModEq U) (SModEq U) (SModEq U) where
trans := trans
theorem add (hxy₁ : x₁ ≡ y₁ [SMOD U]) (hxy₂ : x₂ ≡ y₂ [SMOD U]) : x₁ + x₂ ≡ y₁ + y₂ [SMOD U] := by
rw [SModEq.def] at hxy₁ hxy₂ ⊢
simp_rw [Quotient.mk_add, hxy₁, hxy₂]
#align smodeq.add SModEq.add
| Mathlib/LinearAlgebra/SModEq.lean | 92 | 94 | theorem smul (hxy : x ≡ y [SMOD U]) (c : R) : c • x ≡ c • y [SMOD U] := by |
rw [SModEq.def] at hxy ⊢
simp_rw [Quotient.mk_smul, hxy]
|
import Mathlib.Computability.Halting
import Mathlib.Computability.TuringMachine
import Mathlib.Data.Num.Lemmas
import Mathlib.Tactic.DeriveFintype
#align_import computability.tm_to_partrec from "leanprover-community/mathlib"@"6155d4351090a6fad236e3d2e4e0e4e7342668e8"
open Function (update)
open Relation
namespace Turing
namespace ToPartrec
inductive Code
| zero'
| succ
| tail
| cons : Code → Code → Code
| comp : Code → Code → Code
| case : Code → Code → Code
| fix : Code → Code
deriving DecidableEq, Inhabited
#align turing.to_partrec.code Turing.ToPartrec.Code
#align turing.to_partrec.code.zero' Turing.ToPartrec.Code.zero'
#align turing.to_partrec.code.succ Turing.ToPartrec.Code.succ
#align turing.to_partrec.code.tail Turing.ToPartrec.Code.tail
#align turing.to_partrec.code.cons Turing.ToPartrec.Code.cons
#align turing.to_partrec.code.comp Turing.ToPartrec.Code.comp
#align turing.to_partrec.code.case Turing.ToPartrec.Code.case
#align turing.to_partrec.code.fix Turing.ToPartrec.Code.fix
def Code.eval : Code → List ℕ →. List ℕ
| Code.zero' => fun v => pure (0 :: v)
| Code.succ => fun v => pure [v.headI.succ]
| Code.tail => fun v => pure v.tail
| Code.cons f fs => fun v => do
let n ← Code.eval f v
let ns ← Code.eval fs v
pure (n.headI :: ns)
| Code.comp f g => fun v => g.eval v >>= f.eval
| Code.case f g => fun v => v.headI.rec (f.eval v.tail) fun y _ => g.eval (y::v.tail)
| Code.fix f =>
PFun.fix fun v => (f.eval v).map fun v => if v.headI = 0 then Sum.inl v.tail else Sum.inr v.tail
#align turing.to_partrec.code.eval Turing.ToPartrec.Code.eval
namespace Code
@[simp]
theorem zero'_eval : zero'.eval = fun v => pure (0 :: v) := by simp [eval]
@[simp]
theorem succ_eval : succ.eval = fun v => pure [v.headI.succ] := by simp [eval]
@[simp]
theorem tail_eval : tail.eval = fun v => pure v.tail := by simp [eval]
@[simp]
theorem cons_eval (f fs) : (cons f fs).eval = fun v => do {
let n ← Code.eval f v
let ns ← Code.eval fs v
pure (n.headI :: ns) } := by simp [eval]
@[simp]
theorem comp_eval (f g) : (comp f g).eval = fun v => g.eval v >>= f.eval := by simp [eval]
@[simp]
| Mathlib/Computability/TMToPartrec.lean | 158 | 160 | theorem case_eval (f g) :
(case f g).eval = fun v => v.headI.rec (f.eval v.tail) fun y _ => g.eval (y::v.tail) := by |
simp [eval]
|
import Mathlib.Algebra.Group.Defs
variable {α β δ : Type*} [AddZeroClass δ] [Min δ]
namespace Levenshtein
structure Cost (α β δ : Type*) where
delete : α → δ
insert : β → δ
substitute : α → β → δ
@[simps]
def defaultCost [DecidableEq α] : Cost α α ℕ where
delete _ := 1
insert _ := 1
substitute a b := if a = b then 0 else 1
instance [DecidableEq α] : Inhabited (Cost α α ℕ) := ⟨defaultCost⟩
@[simps]
def weightCost (f : α → ℕ) : Cost α α ℕ where
delete a := f a
insert b := f b
substitute a b := max (f a) (f b)
@[simps!]
def stringLengthCost : Cost String String ℕ := weightCost String.length
@[simps!]
def stringLogLengthCost : Cost String String ℕ := weightCost fun s => Nat.log2 (s.length + 1)
variable (C : Cost α β δ)
def impl
(xs : List α) (y : β) (d : {r : List δ // 0 < r.length}) : {r : List δ // 0 < r.length} :=
let ⟨ds, w⟩ := d
xs.zip (ds.zip ds.tail) |>.foldr
(init := ⟨[C.insert y + ds.getLast (List.length_pos.mp w)], by simp⟩)
(fun ⟨x, d₀, d₁⟩ ⟨r, w⟩ =>
⟨min (C.delete x + r[0]) (min (C.insert y + d₀) (C.substitute x y + d₁)) :: r, by simp⟩)
variable {C}
variable (x : α) (xs : List α) (y : β) (d : δ) (ds : List δ) (w : 0 < (d :: ds).length)
-- Note this lemma has an unspecified proof `w'` on the right-hand-side,
-- which will become an extra goal when rewriting.
theorem impl_cons (w' : 0 < List.length ds) :
impl C (x :: xs) y ⟨d :: ds, w⟩ =
let ⟨r, w⟩ := impl C xs y ⟨ds, w'⟩
⟨min (C.delete x + r[0]) (min (C.insert y + d) (C.substitute x y + ds[0])) :: r, by simp⟩ :=
match ds, w' with | _ :: _, _ => rfl
-- Note this lemma has two unspecified proofs: `h` appears on the left-hand-side
-- and should be found by matching, but `w'` will become an extra goal when rewriting.
theorem impl_cons_fst_zero (h) (w' : 0 < List.length ds) :
(impl C (x :: xs) y ⟨d :: ds, w⟩).1[0] =
let ⟨r, w⟩ := impl C xs y ⟨ds, w'⟩
min (C.delete x + r[0]) (min (C.insert y + d) (C.substitute x y + ds[0])) :=
match ds, w' with | _ :: _, _ => rfl
| Mathlib/Data/List/EditDistance/Defs.lean | 125 | 135 | theorem impl_length (d : {r : List δ // 0 < r.length}) (w : d.1.length = xs.length + 1) :
(impl C xs y d).1.length = xs.length + 1 := by |
induction xs generalizing d with
| nil => rfl
| cons x xs ih =>
dsimp [impl]
match d, w with
| ⟨d₁ :: d₂ :: ds, _⟩, w =>
dsimp
congr 1
exact ih ⟨d₂ :: ds, (by simp)⟩ (by simpa using w)
|
import Mathlib.Algebra.GroupWithZero.Hom
import Mathlib.Algebra.Order.Group.Instances
import Mathlib.Algebra.Order.GroupWithZero.Canonical
import Mathlib.Order.Hom.Basic
#align_import algebra.order.hom.monoid from "leanprover-community/mathlib"@"3342d1b2178381196f818146ff79bc0e7ccd9e2d"
open Function
variable {F α β γ δ : Type*}
section OrderedZero
variable [FunLike F α β]
variable [Preorder α] [Zero α] [Preorder β] [Zero β] [OrderHomClass F α β]
[ZeroHomClass F α β] (f : F) {a : α}
| Mathlib/Algebra/Order/Hom/Monoid.lean | 177 | 179 | theorem map_nonneg (ha : 0 ≤ a) : 0 ≤ f a := by |
rw [← map_zero f]
exact OrderHomClass.mono _ ha
|
import Mathlib.Analysis.SpecialFunctions.Pow.NNReal
import Mathlib.Analysis.SpecialFunctions.Pow.Continuity
import Mathlib.Analysis.SumOverResidueClass
#align_import analysis.p_series from "leanprover-community/mathlib"@"0b9eaaa7686280fad8cce467f5c3c57ee6ce77f8"
def SuccDiffBounded (C : ℕ) (u : ℕ → ℕ) : Prop :=
∀ n : ℕ, u (n + 2) - u (n + 1) ≤ C • (u (n + 1) - u n)
namespace Finset
variable {M : Type*} [OrderedAddCommMonoid M] {f : ℕ → M} {u : ℕ → ℕ}
theorem le_sum_schlomilch' (hf : ∀ ⦃m n⦄, 0 < m → m ≤ n → f n ≤ f m) (h_pos : ∀ n, 0 < u n)
(hu : Monotone u) (n : ℕ) :
(∑ k ∈ Ico (u 0) (u n), f k) ≤ ∑ k ∈ range n, (u (k + 1) - u k) • f (u k) := by
induction' n with n ihn
· simp
suffices (∑ k ∈ Ico (u n) (u (n + 1)), f k) ≤ (u (n + 1) - u n) • f (u n) by
rw [sum_range_succ, ← sum_Ico_consecutive]
· exact add_le_add ihn this
exacts [hu n.zero_le, hu n.le_succ]
have : ∀ k ∈ Ico (u n) (u (n + 1)), f k ≤ f (u n) := fun k hk =>
hf (Nat.succ_le_of_lt (h_pos n)) (mem_Ico.mp hk).1
convert sum_le_sum this
simp [pow_succ, mul_two]
theorem le_sum_condensed' (hf : ∀ ⦃m n⦄, 0 < m → m ≤ n → f n ≤ f m) (n : ℕ) :
(∑ k ∈ Ico 1 (2 ^ n), f k) ≤ ∑ k ∈ range n, 2 ^ k • f (2 ^ k) := by
convert le_sum_schlomilch' hf (fun n => pow_pos zero_lt_two n)
(fun m n hm => pow_le_pow_right one_le_two hm) n using 2
simp [pow_succ, mul_two, two_mul]
#align finset.le_sum_condensed' Finset.le_sum_condensed'
theorem le_sum_schlomilch (hf : ∀ ⦃m n⦄, 0 < m → m ≤ n → f n ≤ f m) (h_pos : ∀ n, 0 < u n)
(hu : Monotone u) (n : ℕ) :
(∑ k ∈ range (u n), f k) ≤
∑ k ∈ range (u 0), f k + ∑ k ∈ range n, (u (k + 1) - u k) • f (u k) := by
convert add_le_add_left (le_sum_schlomilch' hf h_pos hu n) (∑ k ∈ range (u 0), f k)
rw [← sum_range_add_sum_Ico _ (hu n.zero_le)]
| Mathlib/Analysis/PSeries.lean | 78 | 81 | theorem le_sum_condensed (hf : ∀ ⦃m n⦄, 0 < m → m ≤ n → f n ≤ f m) (n : ℕ) :
(∑ k ∈ range (2 ^ n), f k) ≤ f 0 + ∑ k ∈ range n, 2 ^ k • f (2 ^ k) := by |
convert add_le_add_left (le_sum_condensed' hf n) (f 0)
rw [← sum_range_add_sum_Ico _ n.one_le_two_pow, sum_range_succ, sum_range_zero, zero_add]
|
import Mathlib.Analysis.MeanInequalities
import Mathlib.Analysis.NormedSpace.WithLp
open Real Set Filter RCLike Bornology Uniformity Topology NNReal ENNReal
noncomputable section
variable (p : ℝ≥0∞) (𝕜 α β : Type*)
namespace WithLp
section DistNorm
section EDist
variable [EDist α] [EDist β]
open scoped Classical in
instance instProdEDist : EDist (WithLp p (α × β)) where
edist f g :=
if _hp : p = 0 then
(if edist f.fst g.fst = 0 then 0 else 1) + (if edist f.snd g.snd = 0 then 0 else 1)
else if p = ∞ then
edist f.fst g.fst ⊔ edist f.snd g.snd
else
(edist f.fst g.fst ^ p.toReal + edist f.snd g.snd ^ p.toReal) ^ (1 / p.toReal)
variable {p α β}
variable (x y : WithLp p (α × β)) (x' : α × β)
@[simp]
theorem prod_edist_eq_card (f g : WithLp 0 (α × β)) :
edist f g =
(if edist f.fst g.fst = 0 then 0 else 1) + (if edist f.snd g.snd = 0 then 0 else 1) := by
convert if_pos rfl
theorem prod_edist_eq_add (hp : 0 < p.toReal) (f g : WithLp p (α × β)) :
edist f g = (edist f.fst g.fst ^ p.toReal + edist f.snd g.snd ^ p.toReal) ^ (1 / p.toReal) :=
let hp' := ENNReal.toReal_pos_iff.mp hp
(if_neg hp'.1.ne').trans (if_neg hp'.2.ne)
| Mathlib/Analysis/NormedSpace/ProdLp.lean | 171 | 174 | theorem prod_edist_eq_sup (f g : WithLp ∞ (α × β)) :
edist f g = edist f.fst g.fst ⊔ edist f.snd g.snd := by |
dsimp [edist]
exact if_neg ENNReal.top_ne_zero
|
import Mathlib.LinearAlgebra.FiniteDimensional
import Mathlib.LinearAlgebra.GeneralLinearGroup
import Mathlib.LinearAlgebra.Matrix.Reindex
import Mathlib.Tactic.FieldSimp
import Mathlib.LinearAlgebra.Matrix.NonsingularInverse
import Mathlib.LinearAlgebra.Matrix.Basis
#align_import linear_algebra.determinant from "leanprover-community/mathlib"@"0c1d80f5a86b36c1db32e021e8d19ae7809d5b79"
noncomputable section
open Matrix LinearMap Submodule Set Function
universe u v w
variable {R : Type*} [CommRing R]
variable {M : Type*} [AddCommGroup M] [Module R M]
variable {M' : Type*} [AddCommGroup M'] [Module R M']
variable {ι : Type*} [DecidableEq ι] [Fintype ι]
variable (e : Basis ι R M)
section Conjugate
variable {A : Type*} [CommRing A]
variable {m n : Type*}
def equivOfPiLEquivPi {R : Type*} [Finite m] [Finite n] [CommRing R] [Nontrivial R]
(e : (m → R) ≃ₗ[R] n → R) : m ≃ n :=
Basis.indexEquiv (Basis.ofEquivFun e.symm) (Pi.basisFun _ _)
#align equiv_of_pi_lequiv_pi equivOfPiLEquivPi
namespace Matrix
variable [Fintype m] [Fintype n]
def indexEquivOfInv [Nontrivial A] [DecidableEq m] [DecidableEq n] {M : Matrix m n A}
{M' : Matrix n m A} (hMM' : M * M' = 1) (hM'M : M' * M = 1) : m ≃ n :=
equivOfPiLEquivPi (toLin'OfInv hMM' hM'M)
#align matrix.index_equiv_of_inv Matrix.indexEquivOfInv
| Mathlib/LinearAlgebra/Determinant.lean | 77 | 78 | theorem det_comm [DecidableEq n] (M N : Matrix n n A) : det (M * N) = det (N * M) := by |
rw [det_mul, det_mul, mul_comm]
|
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."]
| Mathlib/Combinatorics/Additive/PluenneckeRuzsa.lean | 83 | 86 | 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 _ _ _
|
import Mathlib.LinearAlgebra.Basis.VectorSpace
import Mathlib.LinearAlgebra.Dimension.Constructions
import Mathlib.LinearAlgebra.Dimension.Finite
#align_import field_theory.finiteness from "leanprover-community/mathlib"@"039a089d2a4b93c761b234f3e5f5aeb752bac60f"
universe u v
open scoped Classical
open Cardinal
open Cardinal Submodule Module Function
namespace IsNoetherian
variable {K : Type u} {V : Type v} [DivisionRing K] [AddCommGroup V] [Module K V]
theorem iff_rank_lt_aleph0 : IsNoetherian K V ↔ Module.rank K V < ℵ₀ := by
let b := Basis.ofVectorSpace K V
rw [← b.mk_eq_rank'', lt_aleph0_iff_set_finite]
constructor
· intro
exact (Basis.ofVectorSpaceIndex.linearIndependent K V).set_finite_of_isNoetherian
· intro hbfinite
refine
@isNoetherian_of_linearEquiv K (⊤ : Submodule K V) V _ _ _ _ _ (LinearEquiv.ofTop _ rfl)
(id ?_)
refine isNoetherian_of_fg_of_noetherian _ ⟨Set.Finite.toFinset hbfinite, ?_⟩
rw [Set.Finite.coe_toFinset, ← b.span_eq, Basis.coe_ofVectorSpace, Subtype.range_coe]
#align is_noetherian.iff_rank_lt_aleph_0 IsNoetherian.iff_rank_lt_aleph0
#align is_noetherian.rank_lt_aleph_0 rank_lt_aleph0
noncomputable def fintypeBasisIndex {ι : Type*} [IsNoetherian K V] (b : Basis ι K V) : Fintype ι :=
b.fintypeIndexOfRankLtAleph0 (rank_lt_aleph0 K V)
#align is_noetherian.fintype_basis_index IsNoetherian.fintypeBasisIndex
noncomputable instance [IsNoetherian K V] : Fintype (Basis.ofVectorSpaceIndex K V) :=
fintypeBasisIndex (Basis.ofVectorSpace K V)
theorem finite_basis_index {ι : Type*} {s : Set ι} [IsNoetherian K V] (b : Basis s K V) :
s.Finite :=
b.finite_index_of_rank_lt_aleph0 (rank_lt_aleph0 K V)
#align is_noetherian.finite_basis_index IsNoetherian.finite_basis_index
variable (K V)
noncomputable def finsetBasisIndex [IsNoetherian K V] : Finset V :=
(finite_basis_index (Basis.ofVectorSpace K V)).toFinset
#align is_noetherian.finset_basis_index IsNoetherian.finsetBasisIndex
@[simp]
theorem coe_finsetBasisIndex [IsNoetherian K V] :
(↑(finsetBasisIndex K V) : Set V) = Basis.ofVectorSpaceIndex K V :=
Set.Finite.coe_toFinset _
#align is_noetherian.coe_finset_basis_index IsNoetherian.coe_finsetBasisIndex
@[simp]
theorem coeSort_finsetBasisIndex [IsNoetherian K V] :
(finsetBasisIndex K V : Type _) = Basis.ofVectorSpaceIndex K V :=
Set.Finite.coeSort_toFinset _
#align is_noetherian.coe_sort_finset_basis_index IsNoetherian.coeSort_finsetBasisIndex
noncomputable def finsetBasis [IsNoetherian K V] : Basis (finsetBasisIndex K V) K V :=
(Basis.ofVectorSpace K V).reindex (by rw [coeSort_finsetBasisIndex])
#align is_noetherian.finset_basis IsNoetherian.finsetBasis
@[simp]
| Mathlib/FieldTheory/Finiteness.lean | 95 | 97 | theorem range_finsetBasis [IsNoetherian K V] :
Set.range (finsetBasis K V) = Basis.ofVectorSpaceIndex K V := by |
rw [finsetBasis, Basis.range_reindex, Basis.range_ofVectorSpace]
|
import Mathlib.Algebra.Polynomial.AlgebraMap
import Mathlib.Algebra.Polynomial.Degree.Lemmas
import Mathlib.Algebra.Polynomial.HasseDeriv
#align_import data.polynomial.taylor from "leanprover-community/mathlib"@"70fd9563a21e7b963887c9360bd29b2393e6225a"
noncomputable section
namespace Polynomial
open Polynomial
variable {R : Type*} [Semiring R] (r : R) (f : R[X])
def taylor (r : R) : R[X] →ₗ[R] R[X] where
toFun f := f.comp (X + C r)
map_add' f g := add_comp
map_smul' c f := by simp only [smul_eq_C_mul, C_mul_comp, RingHom.id_apply]
#align polynomial.taylor Polynomial.taylor
theorem taylor_apply : taylor r f = f.comp (X + C r) :=
rfl
#align polynomial.taylor_apply Polynomial.taylor_apply
@[simp]
theorem taylor_X : taylor r X = X + C r := by simp only [taylor_apply, X_comp]
set_option linter.uppercaseLean3 false in
#align polynomial.taylor_X Polynomial.taylor_X
@[simp]
theorem taylor_C (x : R) : taylor r (C x) = C x := by simp only [taylor_apply, C_comp]
set_option linter.uppercaseLean3 false in
#align polynomial.taylor_C Polynomial.taylor_C
@[simp]
theorem taylor_zero' : taylor (0 : R) = LinearMap.id := by
ext
simp only [taylor_apply, add_zero, comp_X, _root_.map_zero, LinearMap.id_comp,
Function.comp_apply, LinearMap.coe_comp]
#align polynomial.taylor_zero' Polynomial.taylor_zero'
theorem taylor_zero (f : R[X]) : taylor 0 f = f := by rw [taylor_zero', LinearMap.id_apply]
#align polynomial.taylor_zero Polynomial.taylor_zero
@[simp]
theorem taylor_one : taylor r (1 : R[X]) = C 1 := by rw [← C_1, taylor_C]
#align polynomial.taylor_one Polynomial.taylor_one
@[simp]
theorem taylor_monomial (i : ℕ) (k : R) : taylor r (monomial i k) = C k * (X + C r) ^ i := by
simp [taylor_apply]
#align polynomial.taylor_monomial Polynomial.taylor_monomial
theorem taylor_coeff (n : ℕ) : (taylor r f).coeff n = (hasseDeriv n f).eval r :=
show (lcoeff R n).comp (taylor r) f = (leval r).comp (hasseDeriv n) f by
congr 1; clear! f; ext i
simp only [leval_apply, mul_one, one_mul, eval_monomial, LinearMap.comp_apply, coeff_C_mul,
hasseDeriv_monomial, taylor_apply, monomial_comp, C_1, (commute_X (C r)).add_pow i,
map_sum]
simp only [lcoeff_apply, ← C_eq_natCast, mul_assoc, ← C_pow, ← C_mul, coeff_mul_C,
(Nat.cast_commute _ _).eq, coeff_X_pow, boole_mul, Finset.sum_ite_eq, Finset.mem_range]
split_ifs with h; · rfl
push_neg at h; rw [Nat.choose_eq_zero_of_lt h, Nat.cast_zero, mul_zero]
#align polynomial.taylor_coeff Polynomial.taylor_coeff
@[simp]
theorem taylor_coeff_zero : (taylor r f).coeff 0 = f.eval r := by
rw [taylor_coeff, hasseDeriv_zero, LinearMap.id_apply]
#align polynomial.taylor_coeff_zero Polynomial.taylor_coeff_zero
@[simp]
theorem taylor_coeff_one : (taylor r f).coeff 1 = f.derivative.eval r := by
rw [taylor_coeff, hasseDeriv_one]
#align polynomial.taylor_coeff_one Polynomial.taylor_coeff_one
@[simp]
theorem natDegree_taylor (p : R[X]) (r : R) : natDegree (taylor r p) = natDegree p := by
refine map_natDegree_eq_natDegree _ ?_
nontriviality R
intro n c c0
simp [taylor_monomial, natDegree_C_mul_eq_of_mul_ne_zero, natDegree_pow_X_add_C, c0]
#align polynomial.nat_degree_taylor Polynomial.natDegree_taylor
@[simp]
theorem taylor_mul {R} [CommSemiring R] (r : R) (p q : R[X]) :
taylor r (p * q) = taylor r p * taylor r q := by simp only [taylor_apply, mul_comp]
#align polynomial.taylor_mul Polynomial.taylor_mul
@[simps!]
def taylorAlgHom {R} [CommSemiring R] (r : R) : R[X] →ₐ[R] R[X] :=
AlgHom.ofLinearMap (taylor r) (taylor_one r) (taylor_mul r)
#align polynomial.taylor_alg_hom Polynomial.taylorAlgHom
theorem taylor_taylor {R} [CommSemiring R] (f : R[X]) (r s : R) :
taylor r (taylor s f) = taylor (r + s) f := by
simp only [taylor_apply, comp_assoc, map_add, add_comp, X_comp, C_comp, C_add, add_assoc]
#align polynomial.taylor_taylor Polynomial.taylor_taylor
theorem taylor_eval {R} [CommSemiring R] (r : R) (f : R[X]) (s : R) :
(taylor r f).eval s = f.eval (s + r) := by
simp only [taylor_apply, eval_comp, eval_C, eval_X, eval_add]
#align polynomial.taylor_eval Polynomial.taylor_eval
| Mathlib/Algebra/Polynomial/Taylor.lean | 126 | 127 | theorem taylor_eval_sub {R} [CommRing R] (r : R) (f : R[X]) (s : R) :
(taylor r f).eval (s - r) = f.eval s := by | rw [taylor_eval, sub_add_cancel]
|
import Mathlib.Analysis.LocallyConvex.BalancedCoreHull
import Mathlib.LinearAlgebra.FreeModule.Finite.Matrix
import Mathlib.Topology.Algebra.Module.Simple
import Mathlib.Topology.Algebra.Module.Determinant
import Mathlib.RingTheory.Ideal.LocalRing
#align_import topology.algebra.module.finite_dimension from "leanprover-community/mathlib"@"9425b6f8220e53b059f5a4904786c3c4b50fc057"
universe u v w x
noncomputable section
open Set FiniteDimensional TopologicalSpace Filter
section NormedField
variable {𝕜 : Type u} [hnorm : NontriviallyNormedField 𝕜] {E : Type v} [AddCommGroup E] [Module 𝕜 E]
[TopologicalSpace E] [TopologicalAddGroup E] [ContinuousSMul 𝕜 E] {F : Type w} [AddCommGroup F]
[Module 𝕜 F] [TopologicalSpace F] [TopologicalAddGroup F] [ContinuousSMul 𝕜 F] {F' : Type x}
[AddCommGroup F'] [Module 𝕜 F'] [TopologicalSpace F'] [TopologicalAddGroup F']
[ContinuousSMul 𝕜 F']
| Mathlib/Topology/Algebra/Module/FiniteDimension.lean | 77 | 127 | theorem unique_topology_of_t2 {t : TopologicalSpace 𝕜} (h₁ : @TopologicalAddGroup 𝕜 t _)
(h₂ : @ContinuousSMul 𝕜 𝕜 _ hnorm.toUniformSpace.toTopologicalSpace t) (h₃ : @T2Space 𝕜 t) :
t = hnorm.toUniformSpace.toTopologicalSpace := by |
-- Let `𝓣₀` denote the topology on `𝕜` induced by the norm, and `𝓣` be any T2 vector
-- topology on `𝕜`. To show that `𝓣₀ = 𝓣`, it suffices to show that they have the same
-- neighborhoods of 0.
refine TopologicalAddGroup.ext h₁ inferInstance (le_antisymm ?_ ?_)
· -- To show `𝓣 ≤ 𝓣₀`, we have to show that closed balls are `𝓣`-neighborhoods of 0.
rw [Metric.nhds_basis_closedBall.ge_iff]
-- Let `ε > 0`. Since `𝕜` is nontrivially normed, we have `0 < ‖ξ₀‖ < ε` for some `ξ₀ : 𝕜`.
intro ε hε
rcases NormedField.exists_norm_lt 𝕜 hε with ⟨ξ₀, hξ₀, hξ₀ε⟩
-- Since `ξ₀ ≠ 0` and `𝓣` is T2, we know that `{ξ₀}ᶜ` is a `𝓣`-neighborhood of 0.
-- Porting note: added `mem_compl_singleton_iff.mpr`
have : {ξ₀}ᶜ ∈ @nhds 𝕜 t 0 := IsOpen.mem_nhds isOpen_compl_singleton <|
mem_compl_singleton_iff.mpr <| Ne.symm <| norm_ne_zero_iff.mp hξ₀.ne.symm
-- Thus, its balanced core `𝓑` is too. Let's show that the closed ball of radius `ε` contains
-- `𝓑`, which will imply that the closed ball is indeed a `𝓣`-neighborhood of 0.
have : balancedCore 𝕜 {ξ₀}ᶜ ∈ @nhds 𝕜 t 0 := balancedCore_mem_nhds_zero this
refine mem_of_superset this fun ξ hξ => ?_
-- Let `ξ ∈ 𝓑`. We want to show `‖ξ‖ < ε`. If `ξ = 0`, this is trivial.
by_cases hξ0 : ξ = 0
· rw [hξ0]
exact Metric.mem_closedBall_self hε.le
· rw [mem_closedBall_zero_iff]
-- Now suppose `ξ ≠ 0`. By contradiction, let's assume `ε < ‖ξ‖`, and show that
-- `ξ₀ ∈ 𝓑 ⊆ {ξ₀}ᶜ`, which is a contradiction.
by_contra! h
suffices (ξ₀ * ξ⁻¹) • ξ ∈ balancedCore 𝕜 {ξ₀}ᶜ by
rw [smul_eq_mul 𝕜, mul_assoc, inv_mul_cancel hξ0, mul_one] at this
exact not_mem_compl_iff.mpr (mem_singleton ξ₀) ((balancedCore_subset _) this)
-- For that, we use that `𝓑` is balanced : since `‖ξ₀‖ < ε < ‖ξ‖`, we have `‖ξ₀ / ξ‖ ≤ 1`,
-- hence `ξ₀ = (ξ₀ / ξ) • ξ ∈ 𝓑` because `ξ ∈ 𝓑`.
refine (balancedCore_balanced _).smul_mem ?_ hξ
rw [norm_mul, norm_inv, mul_inv_le_iff (norm_pos_iff.mpr hξ0), mul_one]
exact (hξ₀ε.trans h).le
· -- Finally, to show `𝓣₀ ≤ 𝓣`, we simply argue that `id = (fun x ↦ x • 1)` is continuous from
-- `(𝕜, 𝓣₀)` to `(𝕜, 𝓣)` because `(•) : (𝕜, 𝓣₀) × (𝕜, 𝓣) → (𝕜, 𝓣)` is continuous.
calc
@nhds 𝕜 hnorm.toUniformSpace.toTopologicalSpace 0 =
map id (@nhds 𝕜 hnorm.toUniformSpace.toTopologicalSpace 0) :=
map_id.symm
_ = map (fun x => id x • (1 : 𝕜)) (@nhds 𝕜 hnorm.toUniformSpace.toTopologicalSpace 0) := by
conv_rhs =>
congr
ext
rw [smul_eq_mul, mul_one]
_ ≤ @nhds 𝕜 t ((0 : 𝕜) • (1 : 𝕜)) :=
(@Tendsto.smul_const _ _ _ hnorm.toUniformSpace.toTopologicalSpace t _ _ _ _ _
tendsto_id (1 : 𝕜))
_ = @nhds 𝕜 t 0 := by rw [zero_smul]
|
import Mathlib.Data.PFunctor.Univariate.Basic
#align_import data.pfunctor.univariate.M from "leanprover-community/mathlib"@"8631e2d5ea77f6c13054d9151d82b83069680cb1"
universe u v w
open Nat Function
open List
variable (F : PFunctor.{u})
-- Porting note: the ♯ tactic is never used
-- local prefix:0 "♯" => cast (by first |simp [*]|cc|solve_by_elim)
namespace PFunctor
namespace Approx
inductive CofixA : ℕ → Type u
| continue : CofixA 0
| intro {n} : ∀ a, (F.B a → CofixA n) → CofixA (succ n)
#align pfunctor.approx.cofix_a PFunctor.Approx.CofixA
protected def CofixA.default [Inhabited F.A] : ∀ n, CofixA F n
| 0 => CofixA.continue
| succ n => CofixA.intro default fun _ => CofixA.default n
#align pfunctor.approx.cofix_a.default PFunctor.Approx.CofixA.default
instance [Inhabited F.A] {n} : Inhabited (CofixA F n) :=
⟨CofixA.default F n⟩
theorem cofixA_eq_zero : ∀ x y : CofixA F 0, x = y
| CofixA.continue, CofixA.continue => rfl
#align pfunctor.approx.cofix_a_eq_zero PFunctor.Approx.cofixA_eq_zero
variable {F}
def head' : ∀ {n}, CofixA F (succ n) → F.A
| _, CofixA.intro i _ => i
#align pfunctor.approx.head' PFunctor.Approx.head'
def children' : ∀ {n} (x : CofixA F (succ n)), F.B (head' x) → CofixA F n
| _, CofixA.intro _ f => f
#align pfunctor.approx.children' PFunctor.Approx.children'
theorem approx_eta {n : ℕ} (x : CofixA F (n + 1)) : x = CofixA.intro (head' x) (children' x) := by
cases x; rfl
#align pfunctor.approx.approx_eta PFunctor.Approx.approx_eta
inductive Agree : ∀ {n : ℕ}, CofixA F n → CofixA F (n + 1) → Prop
| continu (x : CofixA F 0) (y : CofixA F 1) : Agree x y
| intro {n} {a} (x : F.B a → CofixA F n) (x' : F.B a → CofixA F (n + 1)) :
(∀ i : F.B a, Agree (x i) (x' i)) → Agree (CofixA.intro a x) (CofixA.intro a x')
#align pfunctor.approx.agree PFunctor.Approx.Agree
def AllAgree (x : ∀ n, CofixA F n) :=
∀ n, Agree (x n) (x (succ n))
#align pfunctor.approx.all_agree PFunctor.Approx.AllAgree
@[simp]
theorem agree_trival {x : CofixA F 0} {y : CofixA F 1} : Agree x y := by constructor
#align pfunctor.approx.agree_trival PFunctor.Approx.agree_trival
| Mathlib/Data/PFunctor/Univariate/M.lean | 89 | 92 | theorem agree_children {n : ℕ} (x : CofixA F (succ n)) (y : CofixA F (succ n + 1)) {i j}
(h₀ : HEq i j) (h₁ : Agree x y) : Agree (children' x i) (children' y j) := by |
cases' h₁ with _ _ _ _ _ _ hagree; cases h₀
apply hagree
|
import Mathlib.Algebra.Regular.Basic
import Mathlib.GroupTheory.GroupAction.Hom
#align_import algebra.regular.smul from "leanprover-community/mathlib"@"550b58538991c8977703fdeb7c9d51a5aa27df11"
variable {R S : Type*} (M : Type*) {a b : R} {s : S}
def IsSMulRegular [SMul R M] (c : R) :=
Function.Injective ((c • ·) : M → M)
#align is_smul_regular IsSMulRegular
theorem IsLeftRegular.isSMulRegular [Mul R] {c : R} (h : IsLeftRegular c) : IsSMulRegular R c :=
h
#align is_left_regular.is_smul_regular IsLeftRegular.isSMulRegular
theorem isLeftRegular_iff [Mul R] {a : R} : IsLeftRegular a ↔ IsSMulRegular R a :=
Iff.rfl
#align is_left_regular_iff isLeftRegular_iff
theorem IsRightRegular.isSMulRegular [Mul R] {c : R} (h : IsRightRegular c) :
IsSMulRegular R (MulOpposite.op c) :=
h
#align is_right_regular.is_smul_regular IsRightRegular.isSMulRegular
theorem isRightRegular_iff [Mul R] {a : R} :
IsRightRegular a ↔ IsSMulRegular R (MulOpposite.op a) :=
Iff.rfl
#align is_right_regular_iff isRightRegular_iff
namespace IsSMulRegular
variable {M}
section SMul
variable [SMul R M] [SMul R S] [SMul S M] [IsScalarTower R S M]
theorem smul (ra : IsSMulRegular M a) (rs : IsSMulRegular M s) : IsSMulRegular M (a • s) :=
fun _ _ ab => rs (ra ((smul_assoc _ _ _).symm.trans (ab.trans (smul_assoc _ _ _))))
#align is_smul_regular.smul IsSMulRegular.smul
theorem of_smul (a : R) (ab : IsSMulRegular M (a • s)) : IsSMulRegular M s :=
@Function.Injective.of_comp _ _ _ (fun m : M => a • m) _ fun c d cd => by
dsimp only [Function.comp_def] at cd
rw [← smul_assoc, ← smul_assoc] at cd
exact ab cd
#align is_smul_regular.of_smul IsSMulRegular.of_smul
@[simp]
theorem smul_iff (b : S) (ha : IsSMulRegular M a) : IsSMulRegular M (a • b) ↔ IsSMulRegular M b :=
⟨of_smul _, ha.smul⟩
#align is_smul_regular.smul_iff IsSMulRegular.smul_iff
theorem isLeftRegular [Mul R] {a : R} (h : IsSMulRegular R a) : IsLeftRegular a :=
h
#align is_smul_regular.is_left_regular IsSMulRegular.isLeftRegular
theorem isRightRegular [Mul R] {a : R} (h : IsSMulRegular R (MulOpposite.op a)) :
IsRightRegular a :=
h
#align is_smul_regular.is_right_regular IsSMulRegular.isRightRegular
theorem mul [Mul R] [IsScalarTower R R M] (ra : IsSMulRegular M a) (rb : IsSMulRegular M b) :
IsSMulRegular M (a * b) :=
ra.smul rb
#align is_smul_regular.mul IsSMulRegular.mul
| Mathlib/Algebra/Regular/SMul.lean | 102 | 105 | theorem of_mul [Mul R] [IsScalarTower R R M] (ab : IsSMulRegular M (a * b)) :
IsSMulRegular M b := by |
rw [← smul_eq_mul] at ab
exact ab.of_smul _
|
import Mathlib.RingTheory.Coprime.Lemmas
import Mathlib.Tactic.NormNum.GCD
namespace Tactic
namespace NormNum
open Qq Lean Elab.Tactic Mathlib.Meta.NormNum
| Mathlib/Tactic/NormNum/IsCoprime.lean | 23 | 26 | theorem int_not_isCoprime_helper (x y : ℤ) (d : ℕ) (hd : Int.gcd x y = d)
(h : Nat.beq d 1 = false) : ¬ IsCoprime x y := by |
rw [Int.isCoprime_iff_gcd_eq_one, hd]
exact Nat.ne_of_beq_eq_false h
|
import Mathlib.Topology.Instances.ENNReal
#align_import order.filter.ennreal from "leanprover-community/mathlib"@"52932b3a083d4142e78a15dc928084a22fea9ba0"
open Filter ENNReal
namespace ENNReal
variable {α : Type*} {f : Filter α}
theorem eventually_le_limsup [CountableInterFilter f] (u : α → ℝ≥0∞) :
∀ᶠ y in f, u y ≤ f.limsup u :=
_root_.eventually_le_limsup
#align ennreal.eventually_le_limsup ENNReal.eventually_le_limsup
theorem limsup_eq_zero_iff [CountableInterFilter f] {u : α → ℝ≥0∞} :
f.limsup u = 0 ↔ u =ᶠ[f] 0 :=
limsup_eq_bot
#align ennreal.limsup_eq_zero_iff ENNReal.limsup_eq_zero_iff
theorem limsup_const_mul_of_ne_top {u : α → ℝ≥0∞} {a : ℝ≥0∞} (ha_top : a ≠ ⊤) :
(f.limsup fun x : α => a * u x) = a * f.limsup u := by
by_cases ha_zero : a = 0
· simp_rw [ha_zero, zero_mul, ← ENNReal.bot_eq_zero]
exact limsup_const_bot
let g := fun x : ℝ≥0∞ => a * x
have hg_bij : Function.Bijective g :=
Function.bijective_iff_has_inverse.mpr
⟨fun x => a⁻¹ * x,
⟨fun x => by simp [g, ← mul_assoc, ENNReal.inv_mul_cancel ha_zero ha_top], fun x => by
simp [g, ← mul_assoc, ENNReal.mul_inv_cancel ha_zero ha_top]⟩⟩
have hg_mono : StrictMono g :=
Monotone.strictMono_of_injective (fun _ _ _ => by rwa [mul_le_mul_left ha_zero ha_top]) hg_bij.1
let g_iso := StrictMono.orderIsoOfSurjective g hg_mono hg_bij.2
exact (OrderIso.limsup_apply g_iso).symm
#align ennreal.limsup_const_mul_of_ne_top ENNReal.limsup_const_mul_of_ne_top
theorem limsup_const_mul [CountableInterFilter f] {u : α → ℝ≥0∞} {a : ℝ≥0∞} :
f.limsup (a * u ·) = a * f.limsup u := by
by_cases ha_top : a ≠ ⊤
· exact limsup_const_mul_of_ne_top ha_top
push_neg at ha_top
by_cases hu : u =ᶠ[f] 0
· have hau : (a * u ·) =ᶠ[f] 0 := hu.mono fun x hx => by simp [hx]
simp only [limsup_congr hu, limsup_congr hau, Pi.zero_apply, ← ENNReal.bot_eq_zero,
limsup_const_bot]
simp
· have hu_mul : ∃ᶠ x : α in f, ⊤ ≤ ite (u x = 0) (0 : ℝ≥0∞) ⊤ := by
rw [EventuallyEq, not_eventually] at hu
refine hu.mono fun x hx => ?_
rw [Pi.zero_apply] at hx
simp [hx]
have h_top_le : (f.limsup fun x : α => ite (u x = 0) (0 : ℝ≥0∞) ⊤) = ⊤ :=
eq_top_iff.mpr (le_limsup_of_frequently_le hu_mul)
have hfu : f.limsup u ≠ 0 := mt limsup_eq_zero_iff.1 hu
simp only [ha_top, top_mul', h_top_le, hfu, ite_false]
#align ennreal.limsup_const_mul ENNReal.limsup_const_mul
| Mathlib/Order/Filter/ENNReal.lean | 71 | 77 | theorem limsup_mul_le [CountableInterFilter f] (u v : α → ℝ≥0∞) :
f.limsup (u * v) ≤ f.limsup u * f.limsup v :=
calc
f.limsup (u * v) ≤ f.limsup fun x => f.limsup u * v x := by |
refine limsup_le_limsup ?_
filter_upwards [@eventually_le_limsup _ f _ u] with x hx using mul_le_mul' hx le_rfl
_ = f.limsup u * f.limsup v := limsup_const_mul
|
import Mathlib.Data.Vector.Basic
#align_import data.vector.mem from "leanprover-community/mathlib"@"509de852e1de55e1efa8eacfa11df0823f26f226"
namespace Vector
variable {α β : Type*} {n : ℕ} (a a' : α)
@[simp]
| Mathlib/Data/Vector/Mem.lean | 26 | 28 | theorem get_mem (i : Fin n) (v : Vector α n) : v.get i ∈ v.toList := by |
rw [get_eq_get]
exact List.get_mem _ _ _
|
import Mathlib.Data.Vector.Basic
import Mathlib.Data.Vector.Snoc
set_option autoImplicit true
namespace Vector
section Fold
section Unary
variable (xs : Vector α n) (f₁ : β → σ₁ → σ₁ × γ) (f₂ : α → σ₂ → σ₂ × β)
@[simp]
theorem mapAccumr_mapAccumr :
mapAccumr f₁ (mapAccumr f₂ xs s₂).snd s₁
= let m := (mapAccumr (fun x s =>
let r₂ := f₂ x s.snd
let r₁ := f₁ r₂.snd s.fst
((r₁.fst, r₂.fst), r₁.snd)
) xs (s₁, s₂))
(m.fst.fst, m.snd) := by
induction xs using Vector.revInductionOn generalizing s₁ s₂ <;> simp_all
@[simp]
theorem mapAccumr_map (f₂ : α → β) :
(mapAccumr f₁ (map f₂ xs) s) = (mapAccumr (fun x s => f₁ (f₂ x) s) xs s) := by
induction xs using Vector.revInductionOn generalizing s <;> simp_all
@[simp]
theorem map_mapAccumr (f₁ : β → γ) :
(map f₁ (mapAccumr f₂ xs s).snd) = (mapAccumr (fun x s =>
let r := (f₂ x s); (r.fst, f₁ r.snd)
) xs s).snd := by
induction xs using Vector.revInductionOn generalizing s <;> simp_all
@[simp]
| Mathlib/Data/Vector/MapLemmas.lean | 50 | 52 | theorem map_map (f₁ : β → γ) (f₂ : α → β) :
map f₁ (map f₂ xs) = map (fun x => f₁ <| f₂ x) xs := by |
induction xs <;> simp_all
|
import Mathlib.Data.Finsupp.Basic
import Mathlib.Data.List.AList
#align_import data.finsupp.alist from "leanprover-community/mathlib"@"59694bd07f0a39c5beccba34bd9f413a160782bf"
namespace AList
variable {α M : Type*} [Zero M]
open List
noncomputable def lookupFinsupp (l : AList fun _x : α => M) : α →₀ M where
support := by
haveI := Classical.decEq α; haveI := Classical.decEq M
exact (l.1.filter fun x => Sigma.snd x ≠ 0).keys.toFinset
toFun a :=
haveI := Classical.decEq α
(l.lookup a).getD 0
mem_support_toFun a := by
classical
simp_rw [@mem_toFinset _ _, List.mem_keys, List.mem_filter, ← mem_lookup_iff]
cases lookup a l <;> simp
#align alist.lookup_finsupp AList.lookupFinsupp
@[simp]
theorem lookupFinsupp_apply [DecidableEq α] (l : AList fun _x : α => M) (a : α) :
l.lookupFinsupp a = (l.lookup a).getD 0 := by
convert rfl; congr
#align alist.lookup_finsupp_apply AList.lookupFinsupp_apply
@[simp]
theorem lookupFinsupp_support [DecidableEq α] [DecidableEq M] (l : AList fun _x : α => M) :
l.lookupFinsupp.support = (l.1.filter fun x => Sigma.snd x ≠ 0).keys.toFinset := by
convert rfl; congr
· apply Subsingleton.elim
· funext; congr
#align alist.lookup_finsupp_support AList.lookupFinsupp_support
theorem lookupFinsupp_eq_iff_of_ne_zero [DecidableEq α] {l : AList fun _x : α => M} {a : α} {x : M}
(hx : x ≠ 0) : l.lookupFinsupp a = x ↔ x ∈ l.lookup a := by
rw [lookupFinsupp_apply]
cases' lookup a l with m <;> simp [hx.symm]
#align alist.lookup_finsupp_eq_iff_of_ne_zero AList.lookupFinsupp_eq_iff_of_ne_zero
theorem lookupFinsupp_eq_zero_iff [DecidableEq α] {l : AList fun _x : α => M} {a : α} :
l.lookupFinsupp a = 0 ↔ a ∉ l ∨ (0 : M) ∈ l.lookup a := by
rw [lookupFinsupp_apply, ← lookup_eq_none]
cases' lookup a l with m <;> simp
#align alist.lookup_finsupp_eq_zero_iff AList.lookupFinsupp_eq_zero_iff
@[simp]
| Mathlib/Data/Finsupp/AList.lean | 102 | 105 | theorem empty_lookupFinsupp : lookupFinsupp (∅ : AList fun _x : α => M) = 0 := by |
classical
ext
simp
|
import Mathlib.Analysis.Convex.Basic
import Mathlib.Analysis.Convex.Hull
import Mathlib.Analysis.NormedSpace.Basic
import Mathlib.Topology.Bornology.Absorbs
#align_import analysis.locally_convex.basic from "leanprover-community/mathlib"@"f2ce6086713c78a7f880485f7917ea547a215982"
open Set
open Pointwise Topology
variable {𝕜 𝕝 E : Type*} {ι : Sort*} {κ : ι → Sort*}
section SeminormedRing
variable [SeminormedRing 𝕜]
section SMul
variable [SMul 𝕜 E] {s t u v A B : Set E}
variable (𝕜)
def Balanced (A : Set E) :=
∀ a : 𝕜, ‖a‖ ≤ 1 → a • A ⊆ A
#align balanced Balanced
variable {𝕜}
lemma absorbs_iff_norm : Absorbs 𝕜 A B ↔ ∃ r, ∀ c : 𝕜, r ≤ ‖c‖ → B ⊆ c • A :=
Filter.atTop_basis.cobounded_of_norm.eventually_iff.trans <| by simp only [true_and]; rfl
alias ⟨_, Absorbs.of_norm⟩ := absorbs_iff_norm
lemma Absorbs.exists_pos (h : Absorbs 𝕜 A B) : ∃ r > 0, ∀ c : 𝕜, r ≤ ‖c‖ → B ⊆ c • A :=
let ⟨r, hr₁, hr⟩ := (Filter.atTop_basis' 1).cobounded_of_norm.eventually_iff.1 h
⟨r, one_pos.trans_le hr₁, hr⟩
theorem balanced_iff_smul_mem : Balanced 𝕜 s ↔ ∀ ⦃a : 𝕜⦄, ‖a‖ ≤ 1 → ∀ ⦃x : E⦄, x ∈ s → a • x ∈ s :=
forall₂_congr fun _a _ha => smul_set_subset_iff
#align balanced_iff_smul_mem balanced_iff_smul_mem
alias ⟨Balanced.smul_mem, _⟩ := balanced_iff_smul_mem
#align balanced.smul_mem Balanced.smul_mem
| Mathlib/Analysis/LocallyConvex/Basic.lean | 81 | 82 | theorem balanced_iff_closedBall_smul : Balanced 𝕜 s ↔ Metric.closedBall (0 : 𝕜) 1 • s ⊆ s := by |
simp [balanced_iff_smul_mem, smul_subset_iff]
|
import Mathlib.Logic.Encodable.Lattice
import Mathlib.MeasureTheory.MeasurableSpace.Defs
#align_import measure_theory.pi_system from "leanprover-community/mathlib"@"98e83c3d541c77cdb7da20d79611a780ff8e7d90"
open MeasurableSpace Set
open scoped Classical
open MeasureTheory
def IsPiSystem {α} (C : Set (Set α)) : Prop :=
∀ᵉ (s ∈ C) (t ∈ C), (s ∩ t : Set α).Nonempty → s ∩ t ∈ C
#align is_pi_system IsPiSystem
theorem IsPiSystem.singleton {α} (S : Set α) : IsPiSystem ({S} : Set (Set α)) := by
intro s h_s t h_t _
rw [Set.mem_singleton_iff.1 h_s, Set.mem_singleton_iff.1 h_t, Set.inter_self,
Set.mem_singleton_iff]
#align is_pi_system.singleton IsPiSystem.singleton
theorem IsPiSystem.insert_empty {α} {S : Set (Set α)} (h_pi : IsPiSystem S) :
IsPiSystem (insert ∅ S) := by
intro s hs t ht hst
cases' hs with hs hs
· simp [hs]
· cases' ht with ht ht
· simp [ht]
· exact Set.mem_insert_of_mem _ (h_pi s hs t ht hst)
#align is_pi_system.insert_empty IsPiSystem.insert_empty
theorem IsPiSystem.insert_univ {α} {S : Set (Set α)} (h_pi : IsPiSystem S) :
IsPiSystem (insert Set.univ S) := by
intro s hs t ht hst
cases' hs with hs hs
· cases' ht with ht ht <;> simp [hs, ht]
· cases' ht with ht ht
· simp [hs, ht]
· exact Set.mem_insert_of_mem _ (h_pi s hs t ht hst)
#align is_pi_system.insert_univ IsPiSystem.insert_univ
theorem IsPiSystem.comap {α β} {S : Set (Set β)} (h_pi : IsPiSystem S) (f : α → β) :
IsPiSystem { s : Set α | ∃ t ∈ S, f ⁻¹' t = s } := by
rintro _ ⟨s, hs_mem, rfl⟩ _ ⟨t, ht_mem, rfl⟩ hst
rw [← Set.preimage_inter] at hst ⊢
exact ⟨s ∩ t, h_pi s hs_mem t ht_mem (nonempty_of_nonempty_preimage hst), rfl⟩
#align is_pi_system.comap IsPiSystem.comap
theorem isPiSystem_iUnion_of_directed_le {α ι} (p : ι → Set (Set α))
(hp_pi : ∀ n, IsPiSystem (p n)) (hp_directed : Directed (· ≤ ·) p) :
IsPiSystem (⋃ n, p n) := by
intro t1 ht1 t2 ht2 h
rw [Set.mem_iUnion] at ht1 ht2 ⊢
cases' ht1 with n ht1
cases' ht2 with m ht2
obtain ⟨k, hpnk, hpmk⟩ : ∃ k, p n ≤ p k ∧ p m ≤ p k := hp_directed n m
exact ⟨k, hp_pi k t1 (hpnk ht1) t2 (hpmk ht2) h⟩
#align is_pi_system_Union_of_directed_le isPiSystem_iUnion_of_directed_le
theorem isPiSystem_iUnion_of_monotone {α ι} [SemilatticeSup ι] (p : ι → Set (Set α))
(hp_pi : ∀ n, IsPiSystem (p n)) (hp_mono : Monotone p) : IsPiSystem (⋃ n, p n) :=
isPiSystem_iUnion_of_directed_le p hp_pi (Monotone.directed_le hp_mono)
#align is_pi_system_Union_of_monotone isPiSystem_iUnion_of_monotone
section Order
variable {α : Type*} {ι ι' : Sort*} [LinearOrder α]
| Mathlib/MeasureTheory/PiSystem.lean | 132 | 134 | theorem isPiSystem_image_Iio (s : Set α) : IsPiSystem (Iio '' s) := by |
rintro _ ⟨a, ha, rfl⟩ _ ⟨b, hb, rfl⟩ -
exact ⟨a ⊓ b, inf_ind a b ha hb, Iio_inter_Iio.symm⟩
|
import Mathlib.RingTheory.Localization.AtPrime
import Mathlib.RingTheory.Localization.Basic
import Mathlib.RingTheory.Localization.FractionRing
#align_import ring_theory.localization.localization_localization from "leanprover-community/mathlib"@"831c494092374cfe9f50591ed0ac81a25efc5b86"
open Function
namespace IsLocalization
section LocalizationLocalization
variable {R : Type*} [CommSemiring R] (M : Submonoid R) {S : Type*} [CommSemiring S]
variable [Algebra R S] {P : Type*} [CommSemiring P]
variable (N : Submonoid S) (T : Type*) [CommSemiring T] [Algebra R T]
section
variable [Algebra S T] [IsScalarTower R S T]
-- This should only be defined when `S` is the localization `M⁻¹R`, hence the nolint.
@[nolint unusedArguments]
def localizationLocalizationSubmodule : Submonoid R :=
(N ⊔ M.map (algebraMap R S)).comap (algebraMap R S)
#align is_localization.localization_localization_submodule IsLocalization.localizationLocalizationSubmodule
variable {M N}
@[simp]
theorem mem_localizationLocalizationSubmodule {x : R} :
x ∈ localizationLocalizationSubmodule M N ↔
∃ (y : N) (z : M), algebraMap R S x = y * algebraMap R S z := by
rw [localizationLocalizationSubmodule, Submonoid.mem_comap, Submonoid.mem_sup]
constructor
· rintro ⟨y, hy, _, ⟨z, hz, rfl⟩, e⟩
exact ⟨⟨y, hy⟩, ⟨z, hz⟩, e.symm⟩
· rintro ⟨y, z, e⟩
exact ⟨y, y.prop, _, ⟨z, z.prop, rfl⟩, e.symm⟩
#align is_localization.mem_localization_localization_submodule IsLocalization.mem_localizationLocalizationSubmodule
variable (M N) [IsLocalization M S]
theorem localization_localization_map_units [IsLocalization N T]
(y : localizationLocalizationSubmodule M N) : IsUnit (algebraMap R T y) := by
obtain ⟨y', z, eq⟩ := mem_localizationLocalizationSubmodule.mp y.prop
rw [IsScalarTower.algebraMap_apply R S T, eq, RingHom.map_mul, IsUnit.mul_iff]
exact ⟨IsLocalization.map_units T y', (IsLocalization.map_units _ z).map (algebraMap S T)⟩
#align is_localization.localization_localization_map_units IsLocalization.localization_localization_map_units
theorem localization_localization_surj [IsLocalization N T] (x : T) :
∃ y : R × localizationLocalizationSubmodule M N,
x * algebraMap R T y.2 = algebraMap R T y.1 := by
rcases IsLocalization.surj N x with ⟨⟨y, s⟩, eq₁⟩
-- x = y / s
rcases IsLocalization.surj M y with ⟨⟨z, t⟩, eq₂⟩
-- y = z / t
rcases IsLocalization.surj M (s : S) with ⟨⟨z', t'⟩, eq₃⟩
-- s = z' / t'
dsimp only at eq₁ eq₂ eq₃
refine ⟨⟨z * t', z' * t, ?_⟩, ?_⟩ -- x = y / s = (z * t') / (z' * t)
· rw [mem_localizationLocalizationSubmodule]
refine ⟨s, t * t', ?_⟩
rw [RingHom.map_mul, ← eq₃, mul_assoc, ← RingHom.map_mul, mul_comm t, Submonoid.coe_mul]
· simp only [Subtype.coe_mk, RingHom.map_mul, IsScalarTower.algebraMap_apply R S T, ← eq₃, ← eq₂,
← eq₁]
ring
#align is_localization.localization_localization_surj IsLocalization.localization_localization_surj
| Mathlib/RingTheory/Localization/LocalizationLocalization.lean | 92 | 108 | theorem localization_localization_exists_of_eq [IsLocalization N T] (x y : R) :
algebraMap R T x = algebraMap R T y →
∃ c : localizationLocalizationSubmodule M N, ↑c * x = ↑c * y := by |
rw [IsScalarTower.algebraMap_apply R S T, IsScalarTower.algebraMap_apply R S T,
IsLocalization.eq_iff_exists N T]
rintro ⟨z, eq₁⟩
rcases IsLocalization.surj M (z : S) with ⟨⟨z', s⟩, eq₂⟩
dsimp only at eq₂
suffices (algebraMap R S) (x * z' : R) = (algebraMap R S) (y * z') by
obtain ⟨c, eq₃ : ↑c * (x * z') = ↑c * (y * z')⟩ := (IsLocalization.eq_iff_exists M S).mp this
refine ⟨⟨c * z', ?_⟩, ?_⟩
· rw [mem_localizationLocalizationSubmodule]
refine ⟨z, c * s, ?_⟩
rw [map_mul, ← eq₂, Submonoid.coe_mul, map_mul, mul_left_comm]
· rwa [mul_comm _ z', mul_comm _ z', ← mul_assoc, ← mul_assoc] at eq₃
rw [map_mul, map_mul, ← eq₂, ← mul_assoc, ← mul_assoc, mul_comm _ (z : S), eq₁,
mul_comm _ (z : S)]
|
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]
| Mathlib/Data/Matrix/RowCol.lean | 61 | 63 | theorem col_add [Add α] (v w : m → α) : col (v + w) = col v + col w := by |
ext
rfl
|
import Mathlib.CategoryTheory.Limits.Shapes.Pullbacks
import Mathlib.CategoryTheory.Limits.Shapes.BinaryProducts
import Mathlib.CategoryTheory.Limits.Preserves.Shapes.Pullbacks
#align_import category_theory.limits.constructions.epi_mono from "leanprover-community/mathlib"@"f7baecbb54bd0f24f228576f97b1752fc3c9b318"
universe v₁ v₂ u₁ u₂
namespace CategoryTheory
open Category Limits
variable {C : Type u₁} {D : Type u₂} [Category.{v₁} C] [Category.{v₂} D]
variable (F : C ⥤ D)
theorem preserves_mono_of_preservesLimit {X Y : C} (f : X ⟶ Y) [PreservesLimit (cospan f f) F]
[Mono f] : Mono (F.map f) := by
have := isLimitPullbackConeMapOfIsLimit F _ (PullbackCone.isLimitMkIdId f)
simp_rw [F.map_id] at this
apply PullbackCone.mono_of_isLimitMkIdId _ this
#align category_theory.preserves_mono_of_preserves_limit CategoryTheory.preserves_mono_of_preservesLimit
instance (priority := 100) preservesMonomorphisms_of_preservesLimitsOfShape
[PreservesLimitsOfShape WalkingCospan F] : F.PreservesMonomorphisms where
preserves f _ := preserves_mono_of_preservesLimit F f
#align category_theory.preserves_monomorphisms_of_preserves_limits_of_shape CategoryTheory.preservesMonomorphisms_of_preservesLimitsOfShape
theorem reflects_mono_of_reflectsLimit {X Y : C} (f : X ⟶ Y) [ReflectsLimit (cospan f f) F]
[Mono (F.map f)] : Mono f := by
have := PullbackCone.isLimitMkIdId (F.map f)
simp_rw [← F.map_id] at this
apply PullbackCone.mono_of_isLimitMkIdId _ (isLimitOfIsLimitPullbackConeMap F _ this)
#align category_theory.reflects_mono_of_reflects_limit CategoryTheory.reflects_mono_of_reflectsLimit
instance (priority := 100) reflectsMonomorphisms_of_reflectsLimitsOfShape
[ReflectsLimitsOfShape WalkingCospan F] : F.ReflectsMonomorphisms where
reflects f _ := reflects_mono_of_reflectsLimit F f
#align category_theory.reflects_monomorphisms_of_reflects_limits_of_shape CategoryTheory.reflectsMonomorphisms_of_reflectsLimitsOfShape
theorem preserves_epi_of_preservesColimit {X Y : C} (f : X ⟶ Y) [PreservesColimit (span f f) F]
[Epi f] : Epi (F.map f) := by
have := isColimitPushoutCoconeMapOfIsColimit F _ (PushoutCocone.isColimitMkIdId f)
simp_rw [F.map_id] at this
apply PushoutCocone.epi_of_isColimitMkIdId _ this
#align category_theory.preserves_epi_of_preserves_colimit CategoryTheory.preserves_epi_of_preservesColimit
instance (priority := 100) preservesEpimorphisms_of_preservesColimitsOfShape
[PreservesColimitsOfShape WalkingSpan F] : F.PreservesEpimorphisms where
preserves f _ := preserves_epi_of_preservesColimit F f
#align category_theory.preserves_epimorphisms_of_preserves_colimits_of_shape CategoryTheory.preservesEpimorphisms_of_preservesColimitsOfShape
| Mathlib/CategoryTheory/Limits/Constructions/EpiMono.lean | 71 | 77 | theorem reflects_epi_of_reflectsColimit {X Y : C} (f : X ⟶ Y) [ReflectsColimit (span f f) F]
[Epi (F.map f)] : Epi f := by |
have := PushoutCocone.isColimitMkIdId (F.map f)
simp_rw [← F.map_id] at this
apply
PushoutCocone.epi_of_isColimitMkIdId _
(isColimitOfIsColimitPushoutCoconeMap F _ this)
|
import Mathlib.Data.Set.Image
import Mathlib.Data.SProd
#align_import data.set.prod from "leanprover-community/mathlib"@"48fb5b5280e7c81672afc9524185ae994553ebf4"
open Function
namespace Set
section Prod
variable {α β γ δ : Type*} {s s₁ s₂ : Set α} {t t₁ t₂ : Set β} {a : α} {b : β}
theorem Subsingleton.prod (hs : s.Subsingleton) (ht : t.Subsingleton) :
(s ×ˢ t).Subsingleton := fun _x hx _y hy ↦
Prod.ext (hs hx.1 hy.1) (ht hx.2 hy.2)
noncomputable instance decidableMemProd [DecidablePred (· ∈ s)] [DecidablePred (· ∈ t)] :
DecidablePred (· ∈ s ×ˢ t) := fun _ => And.decidable
#align set.decidable_mem_prod Set.decidableMemProd
@[gcongr]
theorem prod_mono (hs : s₁ ⊆ s₂) (ht : t₁ ⊆ t₂) : s₁ ×ˢ t₁ ⊆ s₂ ×ˢ t₂ :=
fun _ ⟨h₁, h₂⟩ => ⟨hs h₁, ht h₂⟩
#align set.prod_mono Set.prod_mono
@[gcongr]
theorem prod_mono_left (hs : s₁ ⊆ s₂) : s₁ ×ˢ t ⊆ s₂ ×ˢ t :=
prod_mono hs Subset.rfl
#align set.prod_mono_left Set.prod_mono_left
@[gcongr]
theorem prod_mono_right (ht : t₁ ⊆ t₂) : s ×ˢ t₁ ⊆ s ×ˢ t₂ :=
prod_mono Subset.rfl ht
#align set.prod_mono_right Set.prod_mono_right
@[simp]
theorem prod_self_subset_prod_self : s₁ ×ˢ s₁ ⊆ s₂ ×ˢ s₂ ↔ s₁ ⊆ s₂ :=
⟨fun h _ hx => (h (mk_mem_prod hx hx)).1, fun h _ hx => ⟨h hx.1, h hx.2⟩⟩
#align set.prod_self_subset_prod_self Set.prod_self_subset_prod_self
@[simp]
theorem prod_self_ssubset_prod_self : s₁ ×ˢ s₁ ⊂ s₂ ×ˢ s₂ ↔ s₁ ⊂ s₂ :=
and_congr prod_self_subset_prod_self <| not_congr prod_self_subset_prod_self
#align set.prod_self_ssubset_prod_self Set.prod_self_ssubset_prod_self
theorem prod_subset_iff {P : Set (α × β)} : s ×ˢ t ⊆ P ↔ ∀ x ∈ s, ∀ y ∈ t, (x, y) ∈ P :=
⟨fun h _ hx _ hy => h (mk_mem_prod hx hy), fun h ⟨_, _⟩ hp => h _ hp.1 _ hp.2⟩
#align set.prod_subset_iff Set.prod_subset_iff
theorem forall_prod_set {p : α × β → Prop} : (∀ x ∈ s ×ˢ t, p x) ↔ ∀ x ∈ s, ∀ y ∈ t, p (x, y) :=
prod_subset_iff
#align set.forall_prod_set Set.forall_prod_set
theorem exists_prod_set {p : α × β → Prop} : (∃ x ∈ s ×ˢ t, p x) ↔ ∃ x ∈ s, ∃ y ∈ t, p (x, y) := by
simp [and_assoc]
#align set.exists_prod_set Set.exists_prod_set
@[simp]
theorem prod_empty : s ×ˢ (∅ : Set β) = ∅ := by
ext
exact and_false_iff _
#align set.prod_empty Set.prod_empty
@[simp]
theorem empty_prod : (∅ : Set α) ×ˢ t = ∅ := by
ext
exact false_and_iff _
#align set.empty_prod Set.empty_prod
@[simp, mfld_simps]
theorem univ_prod_univ : @univ α ×ˢ @univ β = univ := by
ext
exact true_and_iff _
#align set.univ_prod_univ Set.univ_prod_univ
theorem univ_prod {t : Set β} : (univ : Set α) ×ˢ t = Prod.snd ⁻¹' t := by simp [prod_eq]
#align set.univ_prod Set.univ_prod
theorem prod_univ {s : Set α} : s ×ˢ (univ : Set β) = Prod.fst ⁻¹' s := by simp [prod_eq]
#align set.prod_univ Set.prod_univ
@[simp] lemma prod_eq_univ [Nonempty α] [Nonempty β] : s ×ˢ t = univ ↔ s = univ ∧ t = univ := by
simp [eq_univ_iff_forall, forall_and]
@[simp]
theorem singleton_prod : ({a} : Set α) ×ˢ t = Prod.mk a '' t := by
ext ⟨x, y⟩
simp [and_left_comm, eq_comm]
#align set.singleton_prod Set.singleton_prod
@[simp]
theorem prod_singleton : s ×ˢ ({b} : Set β) = (fun a => (a, b)) '' s := by
ext ⟨x, y⟩
simp [and_left_comm, eq_comm]
#align set.prod_singleton Set.prod_singleton
theorem singleton_prod_singleton : ({a} : Set α) ×ˢ ({b} : Set β) = {(a, b)} := by simp
#align set.singleton_prod_singleton Set.singleton_prod_singleton
@[simp]
theorem union_prod : (s₁ ∪ s₂) ×ˢ t = s₁ ×ˢ t ∪ s₂ ×ˢ t := by
ext ⟨x, y⟩
simp [or_and_right]
#align set.union_prod Set.union_prod
@[simp]
theorem prod_union : s ×ˢ (t₁ ∪ t₂) = s ×ˢ t₁ ∪ s ×ˢ t₂ := by
ext ⟨x, y⟩
simp [and_or_left]
#align set.prod_union Set.prod_union
theorem inter_prod : (s₁ ∩ s₂) ×ˢ t = s₁ ×ˢ t ∩ s₂ ×ˢ t := by
ext ⟨x, y⟩
simp only [← and_and_right, mem_inter_iff, mem_prod]
#align set.inter_prod Set.inter_prod
| Mathlib/Data/Set/Prod.lean | 142 | 144 | theorem prod_inter : s ×ˢ (t₁ ∩ t₂) = s ×ˢ t₁ ∩ s ×ˢ t₂ := by |
ext ⟨x, y⟩
simp only [← and_and_left, mem_inter_iff, mem_prod]
|
import Mathlib.Analysis.SpecialFunctions.Bernstein
import Mathlib.Topology.Algebra.Algebra
#align_import topology.continuous_function.weierstrass from "leanprover-community/mathlib"@"17ef379e997badd73e5eabb4d38f11919ab3c4b3"
open ContinuousMap Filter
open scoped unitInterval
theorem polynomialFunctions_closure_eq_top' : (polynomialFunctions I).topologicalClosure = ⊤ := by
rw [eq_top_iff]
rintro f -
refine Filter.Frequently.mem_closure ?_
refine Filter.Tendsto.frequently (bernsteinApproximation_uniform f) ?_
apply frequently_of_forall
intro n
simp only [SetLike.mem_coe]
apply Subalgebra.sum_mem
rintro n -
apply Subalgebra.smul_mem
dsimp [bernstein, polynomialFunctions]
simp
#align polynomial_functions_closure_eq_top' polynomialFunctions_closure_eq_top'
theorem polynomialFunctions_closure_eq_top (a b : ℝ) :
(polynomialFunctions (Set.Icc a b)).topologicalClosure = ⊤ := by
cases' lt_or_le a b with h h
-- (Otherwise it's easy; we'll deal with that later.)
· -- We can pullback continuous functions on `[a,b]` to continuous functions on `[0,1]`,
-- by precomposing with an affine map.
let W : C(Set.Icc a b, ℝ) →ₐ[ℝ] C(I, ℝ) :=
compRightAlgHom ℝ ℝ (iccHomeoI a b h).symm.toContinuousMap
-- This operation is itself a homeomorphism
-- (with respect to the norm topologies on continuous functions).
let W' : C(Set.Icc a b, ℝ) ≃ₜ C(I, ℝ) := compRightHomeomorph ℝ (iccHomeoI a b h).symm
have w : (W : C(Set.Icc a b, ℝ) → C(I, ℝ)) = W' := rfl
-- Thus we take the statement of the Weierstrass approximation theorem for `[0,1]`,
have p := polynomialFunctions_closure_eq_top'
-- and pullback both sides, obtaining an equation between subalgebras of `C([a,b], ℝ)`.
apply_fun fun s => s.comap W at p
simp only [Algebra.comap_top] at p
-- Since the pullback operation is continuous, it commutes with taking `topologicalClosure`,
rw [Subalgebra.topologicalClosure_comap_homeomorph _ W W' w] at p
-- and precomposing with an affine map takes polynomial functions to polynomial functions.
rw [polynomialFunctions.comap_compRightAlgHom_iccHomeoI] at p
-- 🎉
exact p
· -- Otherwise, `b ≤ a`, and the interval is a subsingleton,
have : Subsingleton (Set.Icc a b) := (Set.subsingleton_Icc_of_ge h).coe_sort
apply Subsingleton.elim
#align polynomial_functions_closure_eq_top polynomialFunctions_closure_eq_top
| Mathlib/Topology/ContinuousFunction/Weierstrass.lean | 86 | 89 | theorem continuousMap_mem_polynomialFunctions_closure (a b : ℝ) (f : C(Set.Icc a b, ℝ)) :
f ∈ (polynomialFunctions (Set.Icc a b)).topologicalClosure := by |
rw [polynomialFunctions_closure_eq_top _ _]
simp
|
import Mathlib.Algebra.ContinuedFractions.Computation.Translations
import Mathlib.Algebra.ContinuedFractions.TerminatedStable
import Mathlib.Algebra.ContinuedFractions.ContinuantsRecurrence
import Mathlib.Order.Filter.AtTopBot
import Mathlib.Tactic.FieldSimp
import Mathlib.Tactic.Ring
#align_import algebra.continued_fractions.computation.correctness_terminating from "leanprover-community/mathlib"@"d6814c584384ddf2825ff038e868451a7c956f31"
namespace GeneralizedContinuedFraction
open GeneralizedContinuedFraction (of)
variable {K : Type*} [LinearOrderedField K] {v : K} {n : ℕ}
protected def compExactValue (pconts conts : Pair K) (fr : K) : K :=
-- if the fractional part is zero, we exactly approximated the value by the last continuants
if fr = 0 then
conts.a / conts.b
else -- otherwise, we have to include the fractional part in a final continuants step.
let exact_conts := nextContinuants 1 fr⁻¹ pconts conts
exact_conts.a / exact_conts.b
#align generalized_continued_fraction.comp_exact_value GeneralizedContinuedFraction.compExactValue
variable [FloorRing K]
protected theorem compExactValue_correctness_of_stream_eq_some_aux_comp {a : K} (b c : K)
(fract_a_ne_zero : Int.fract a ≠ 0) :
((⌊a⌋ : K) * b + c) / Int.fract a + b = (b * a + c) / Int.fract a := by
field_simp [fract_a_ne_zero]
rw [Int.fract]
ring
#align generalized_continued_fraction.comp_exact_value_correctness_of_stream_eq_some_aux_comp GeneralizedContinuedFraction.compExactValue_correctness_of_stream_eq_some_aux_comp
open GeneralizedContinuedFraction
(compExactValue compExactValue_correctness_of_stream_eq_some_aux_comp)
| Mathlib/Algebra/ContinuedFractions/Computation/CorrectnessTerminating.lean | 104 | 212 | theorem compExactValue_correctness_of_stream_eq_some :
∀ {ifp_n : IntFractPair K}, IntFractPair.stream v n = some ifp_n →
v = compExactValue ((of v).continuantsAux n) ((of v).continuantsAux <| n + 1) ifp_n.fr := by |
let g := of v
induction' n with n IH
· intro ifp_zero stream_zero_eq
-- Nat.zero
have : IntFractPair.of v = ifp_zero := by
have : IntFractPair.stream v 0 = some (IntFractPair.of v) := rfl
simpa only [Nat.zero_eq, this, Option.some.injEq] using stream_zero_eq
cases this
cases' Decidable.em (Int.fract v = 0) with fract_eq_zero fract_ne_zero
-- Int.fract v = 0; we must then have `v = ⌊v⌋`
· suffices v = ⌊v⌋ by
-- Porting note: was `simpa [continuantsAux, fract_eq_zero, compExactValue]`
field_simp [nextContinuants, nextNumerator, nextDenominator, compExactValue]
have : (IntFractPair.of v).fr = Int.fract v := rfl
rwa [this, if_pos fract_eq_zero]
calc
v = Int.fract v + ⌊v⌋ := by rw [Int.fract_add_floor]
_ = ⌊v⌋ := by simp [fract_eq_zero]
-- Int.fract v ≠ 0; the claim then easily follows by unfolding a single computation step
· field_simp [continuantsAux, nextContinuants, nextNumerator, nextDenominator,
of_h_eq_floor, compExactValue]
-- Porting note: this and the if_neg rewrite are needed
have : (IntFractPair.of v).fr = Int.fract v := rfl
rw [this, if_neg fract_ne_zero, Int.floor_add_fract]
· intro ifp_succ_n succ_nth_stream_eq
-- Nat.succ
obtain ⟨ifp_n, nth_stream_eq, nth_fract_ne_zero, -⟩ :
∃ ifp_n, IntFractPair.stream v n = some ifp_n ∧
ifp_n.fr ≠ 0 ∧ IntFractPair.of ifp_n.fr⁻¹ = ifp_succ_n :=
IntFractPair.succ_nth_stream_eq_some_iff.1 succ_nth_stream_eq
-- introduce some notation
let conts := g.continuantsAux (n + 2)
set pconts := g.continuantsAux (n + 1) with pconts_eq
set ppconts := g.continuantsAux n with ppconts_eq
cases' Decidable.em (ifp_succ_n.fr = 0) with ifp_succ_n_fr_eq_zero ifp_succ_n_fr_ne_zero
-- ifp_succ_n.fr = 0
· suffices v = conts.a / conts.b by simpa [compExactValue, ifp_succ_n_fr_eq_zero]
-- use the IH and the fact that ifp_n.fr⁻¹ = ⌊ifp_n.fr⁻¹⌋ to prove this case
obtain ⟨ifp_n', nth_stream_eq', ifp_n_fract_inv_eq_floor⟩ :
∃ ifp_n, IntFractPair.stream v n = some ifp_n ∧ ifp_n.fr⁻¹ = ⌊ifp_n.fr⁻¹⌋ :=
IntFractPair.exists_succ_nth_stream_of_fr_zero succ_nth_stream_eq ifp_succ_n_fr_eq_zero
have : ifp_n' = ifp_n := by injection Eq.trans nth_stream_eq'.symm nth_stream_eq
cases this
have s_nth_eq : g.s.get? n = some ⟨1, ⌊ifp_n.fr⁻¹⌋⟩ :=
get?_of_eq_some_of_get?_intFractPair_stream_fr_ne_zero nth_stream_eq nth_fract_ne_zero
rw [← ifp_n_fract_inv_eq_floor] at s_nth_eq
suffices v = compExactValue ppconts pconts ifp_n.fr by
simpa [conts, continuantsAux, s_nth_eq, compExactValue, nth_fract_ne_zero] using this
exact IH nth_stream_eq
-- ifp_succ_n.fr ≠ 0
· -- use the IH to show that the following equality suffices
suffices
compExactValue ppconts pconts ifp_n.fr = compExactValue pconts conts ifp_succ_n.fr by
have : v = compExactValue ppconts pconts ifp_n.fr := IH nth_stream_eq
conv_lhs => rw [this]
assumption
-- get the correspondence between ifp_n and ifp_succ_n
obtain ⟨ifp_n', nth_stream_eq', ifp_n_fract_ne_zero, ⟨refl⟩⟩ :
∃ ifp_n, IntFractPair.stream v n = some ifp_n ∧
ifp_n.fr ≠ 0 ∧ IntFractPair.of ifp_n.fr⁻¹ = ifp_succ_n :=
IntFractPair.succ_nth_stream_eq_some_iff.1 succ_nth_stream_eq
have : ifp_n' = ifp_n := by injection Eq.trans nth_stream_eq'.symm nth_stream_eq
cases this
-- get the correspondence between ifp_n and g.s.nth n
have s_nth_eq : g.s.get? n = some ⟨1, (⌊ifp_n.fr⁻¹⌋ : K)⟩ :=
get?_of_eq_some_of_get?_intFractPair_stream_fr_ne_zero nth_stream_eq ifp_n_fract_ne_zero
-- the claim now follows by unfolding the definitions and tedious calculations
-- some shorthand notation
let ppA := ppconts.a
let ppB := ppconts.b
let pA := pconts.a
let pB := pconts.b
have : compExactValue ppconts pconts ifp_n.fr =
(ppA + ifp_n.fr⁻¹ * pA) / (ppB + ifp_n.fr⁻¹ * pB) := by
-- unfold compExactValue and the convergent computation once
field_simp [ifp_n_fract_ne_zero, compExactValue, nextContinuants, nextNumerator,
nextDenominator, ppA, ppB]
ac_rfl
rw [this]
-- two calculations needed to show the claim
have tmp_calc :=
compExactValue_correctness_of_stream_eq_some_aux_comp pA ppA ifp_succ_n_fr_ne_zero
have tmp_calc' :=
compExactValue_correctness_of_stream_eq_some_aux_comp pB ppB ifp_succ_n_fr_ne_zero
let f := Int.fract (1 / ifp_n.fr)
have f_ne_zero : f ≠ 0 := by simpa [f] using ifp_succ_n_fr_ne_zero
rw [inv_eq_one_div] at tmp_calc tmp_calc'
-- Porting note: the `tmp_calc`s need to be massaged, and some processing after `ac_rfl` done,
-- because `field_simp` is not as powerful
have hA : (↑⌊1 / ifp_n.fr⌋ * pA + ppA) + pA * f = pA * (1 / ifp_n.fr) + ppA := by
have := congrFun (congrArg HMul.hMul tmp_calc) f
rwa [right_distrib, div_mul_cancel₀ (h := f_ne_zero),
div_mul_cancel₀ (h := f_ne_zero)] at this
have hB : (↑⌊1 / ifp_n.fr⌋ * pB + ppB) + pB * f = pB * (1 / ifp_n.fr) + ppB := by
have := congrFun (congrArg HMul.hMul tmp_calc') f
rwa [right_distrib, div_mul_cancel₀ (h := f_ne_zero),
div_mul_cancel₀ (h := f_ne_zero)] at this
-- now unfold the recurrence one step and simplify both sides to arrive at the conclusion
dsimp only [conts, pconts, ppconts]
field_simp [compExactValue, continuantsAux_recurrence s_nth_eq ppconts_eq pconts_eq,
nextContinuants, nextNumerator, nextDenominator]
have hfr : (IntFractPair.of (1 / ifp_n.fr)).fr = f := rfl
rw [one_div, if_neg _, ← one_div, hfr]
· field_simp [hA, hB]
ac_rfl
· rwa [inv_eq_one_div, hfr]
|
import Mathlib.Algebra.Polynomial.Degree.CardPowDegree
import Mathlib.Analysis.SpecialFunctions.Pow.Real
import Mathlib.NumberTheory.ClassNumber.AdmissibleAbsoluteValue
import Mathlib.RingTheory.Ideal.LocalRing
#align_import number_theory.class_number.admissible_card_pow_degree from "leanprover-community/mathlib"@"0b9eaaa7686280fad8cce467f5c3c57ee6ce77f8"
namespace Polynomial
open Polynomial
open AbsoluteValue Real
variable {Fq : Type*} [Fintype Fq]
| Mathlib/NumberTheory/ClassNumber/AdmissibleCardPowDegree.lean | 36 | 57 | theorem exists_eq_polynomial [Semiring Fq] {d : ℕ} {m : ℕ} (hm : Fintype.card Fq ^ d ≤ m)
(b : Fq[X]) (hb : natDegree b ≤ d) (A : Fin m.succ → Fq[X])
(hA : ∀ i, degree (A i) < degree b) : ∃ i₀ i₁, i₀ ≠ i₁ ∧ A i₁ = A i₀ := by |
-- Since there are > q^d elements of A, and only q^d choices for the highest `d` coefficients,
-- there must be two elements of A with the same coefficients at
-- `0`, ... `degree b - 1` ≤ `d - 1`.
-- In other words, the following map is not injective:
set f : Fin m.succ → Fin d → Fq := fun i j => (A i).coeff j
have : Fintype.card (Fin d → Fq) < Fintype.card (Fin m.succ) := by
simpa using lt_of_le_of_lt hm (Nat.lt_succ_self m)
-- Therefore, the differences have all coefficients higher than `deg b - d` equal.
obtain ⟨i₀, i₁, i_ne, i_eq⟩ := Fintype.exists_ne_map_eq_of_card_lt f this
use i₀, i₁, i_ne
ext j
-- The coefficients higher than `deg b` are the same because they are equal to 0.
by_cases hbj : degree b ≤ j
· rw [coeff_eq_zero_of_degree_lt (lt_of_lt_of_le (hA _) hbj),
coeff_eq_zero_of_degree_lt (lt_of_lt_of_le (hA _) hbj)]
-- So we only need to look for the coefficients between `0` and `deg b`.
rw [not_le] at hbj
apply congr_fun i_eq.symm ⟨j, _⟩
exact lt_of_lt_of_le (coe_lt_degree.mp hbj) hb
|
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
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]
#align measure_theory.upper_crossing_time_le_lower_crossing_time MeasureTheory.upperCrossingTime_le_lowerCrossingTime
theorem lowerCrossingTime_le_upperCrossingTime_succ :
lowerCrossingTime a b f N n ω ≤ upperCrossingTime a b f N (n + 1) ω := by
rw [upperCrossingTime_succ]
exact le_hitting lowerCrossingTime_le ω
#align measure_theory.lower_crossing_time_le_upper_crossing_time_succ MeasureTheory.lowerCrossingTime_le_upperCrossingTime_succ
| Mathlib/Probability/Martingale/Upcrossing.lean | 212 | 216 | theorem lowerCrossingTime_mono (hnm : n ≤ m) :
lowerCrossingTime a b f N n ω ≤ lowerCrossingTime a b f N m ω := by |
suffices Monotone fun n => lowerCrossingTime a b f N n ω by exact this hnm
exact monotone_nat_of_le_succ fun n =>
le_trans lowerCrossingTime_le_upperCrossingTime_succ upperCrossingTime_le_lowerCrossingTime
|
import Mathlib.Data.ZMod.Quotient
import Mathlib.GroupTheory.NoncommPiCoprod
import Mathlib.GroupTheory.OrderOfElement
import Mathlib.Algebra.GCDMonoid.Finset
import Mathlib.Algebra.GCDMonoid.Nat
import Mathlib.Data.Nat.Factorization.Basic
import Mathlib.Tactic.ByContra
import Mathlib.Tactic.Peel
#align_import group_theory.exponent from "leanprover-community/mathlib"@"52fa514ec337dd970d71d8de8d0fd68b455a1e54"
universe u
variable {G : Type u}
open scoped Classical
namespace Monoid
section Monoid
variable (G) [Monoid G]
@[to_additive
"A predicate on an additive monoid saying that there is a positive integer `n` such\n
that `n • g = 0` for all `g`."]
def ExponentExists :=
∃ n, 0 < n ∧ ∀ g : G, g ^ n = 1
#align monoid.exponent_exists Monoid.ExponentExists
#align add_monoid.exponent_exists AddMonoid.ExponentExists
@[to_additive
"The exponent of an additive group is the smallest positive integer `n` such that\n
`n • g = 0` for all `g ∈ G` if it exists, otherwise it is zero by convention."]
noncomputable def exponent :=
if h : ExponentExists G then Nat.find h else 0
#align monoid.exponent Monoid.exponent
#align add_monoid.exponent AddMonoid.exponent
variable {G}
@[simp]
theorem _root_.AddMonoid.exponent_additive :
AddMonoid.exponent (Additive G) = exponent G := rfl
@[simp]
theorem exponent_multiplicative {G : Type*} [AddMonoid G] :
exponent (Multiplicative G) = AddMonoid.exponent G := rfl
open MulOpposite in
@[to_additive (attr := simp)]
theorem _root_.MulOpposite.exponent : exponent (MulOpposite G) = exponent G := by
simp only [Monoid.exponent, ExponentExists]
congr!
all_goals exact ⟨(op_injective <| · <| op ·), (unop_injective <| · <| unop ·)⟩
@[to_additive]
theorem ExponentExists.isOfFinOrder (h : ExponentExists G) {g : G} : IsOfFinOrder g :=
isOfFinOrder_iff_pow_eq_one.mpr <| by peel 2 h; exact this g
@[to_additive]
theorem ExponentExists.orderOf_pos (h : ExponentExists G) (g : G) : 0 < orderOf g :=
h.isOfFinOrder.orderOf_pos
@[to_additive]
| Mathlib/GroupTheory/Exponent.lean | 108 | 113 | theorem exponent_ne_zero : exponent G ≠ 0 ↔ ExponentExists G := by |
rw [exponent]
split_ifs with h
· simp [h, @not_lt_zero' ℕ]
--if this isn't done this way, `to_additive` freaks
· tauto
|
import Mathlib.MeasureTheory.Measure.MeasureSpace
import Mathlib.MeasureTheory.Measure.Regular
import Mathlib.Topology.Sets.Compacts
#align_import measure_theory.measure.content from "leanprover-community/mathlib"@"d39590fc8728fbf6743249802486f8c91ffe07bc"
universe u v w
noncomputable section
open Set TopologicalSpace
open NNReal ENNReal MeasureTheory
namespace MeasureTheory
variable {G : Type w} [TopologicalSpace G]
structure Content (G : Type w) [TopologicalSpace G] where
toFun : Compacts G → ℝ≥0
mono' : ∀ K₁ K₂ : Compacts G, (K₁ : Set G) ⊆ K₂ → toFun K₁ ≤ toFun K₂
sup_disjoint' :
∀ K₁ K₂ : Compacts G, Disjoint (K₁ : Set G) K₂ → IsClosed (K₁ : Set G) → IsClosed (K₂ : Set G)
→ toFun (K₁ ⊔ K₂) = toFun K₁ + toFun K₂
sup_le' : ∀ K₁ K₂ : Compacts G, toFun (K₁ ⊔ K₂) ≤ toFun K₁ + toFun K₂
#align measure_theory.content MeasureTheory.Content
instance : Inhabited (Content G) :=
⟨{ toFun := fun _ => 0
mono' := by simp
sup_disjoint' := by simp
sup_le' := by simp }⟩
instance : CoeFun (Content G) fun _ => Compacts G → ℝ≥0∞ :=
⟨fun μ s => μ.toFun s⟩
namespace Content
variable (μ : Content G)
theorem apply_eq_coe_toFun (K : Compacts G) : μ K = μ.toFun K :=
rfl
#align measure_theory.content.apply_eq_coe_to_fun MeasureTheory.Content.apply_eq_coe_toFun
| Mathlib/MeasureTheory/Measure/Content.lean | 98 | 99 | theorem mono (K₁ K₂ : Compacts G) (h : (K₁ : Set G) ⊆ K₂) : μ K₁ ≤ μ K₂ := by |
simp [apply_eq_coe_toFun, μ.mono' _ _ h]
|
import Mathlib.FieldTheory.SplittingField.IsSplittingField
import Mathlib.Algebra.CharP.Algebra
#align_import field_theory.splitting_field.construction from "leanprover-community/mathlib"@"e3f4be1fcb5376c4948d7f095bec45350bfb9d1a"
noncomputable section
open scoped Classical Polynomial
universe u v w
variable {F : Type u} {K : Type v} {L : Type w}
namespace Polynomial
variable [Field K] [Field L] [Field F]
open Polynomial
section SplittingField
def factor (f : K[X]) : K[X] :=
if H : ∃ g, Irreducible g ∧ g ∣ f then Classical.choose H else X
#align polynomial.factor Polynomial.factor
theorem irreducible_factor (f : K[X]) : Irreducible (factor f) := by
rw [factor]
split_ifs with H
· exact (Classical.choose_spec H).1
· exact irreducible_X
#align polynomial.irreducible_factor Polynomial.irreducible_factor
theorem fact_irreducible_factor (f : K[X]) : Fact (Irreducible (factor f)) :=
⟨irreducible_factor f⟩
#align polynomial.fact_irreducible_factor Polynomial.fact_irreducible_factor
attribute [local instance] fact_irreducible_factor
theorem factor_dvd_of_not_isUnit {f : K[X]} (hf1 : ¬IsUnit f) : factor f ∣ f := by
by_cases hf2 : f = 0; · rw [hf2]; exact dvd_zero _
rw [factor, dif_pos (WfDvdMonoid.exists_irreducible_factor hf1 hf2)]
exact (Classical.choose_spec <| WfDvdMonoid.exists_irreducible_factor hf1 hf2).2
#align polynomial.factor_dvd_of_not_is_unit Polynomial.factor_dvd_of_not_isUnit
theorem factor_dvd_of_degree_ne_zero {f : K[X]} (hf : f.degree ≠ 0) : factor f ∣ f :=
factor_dvd_of_not_isUnit (mt degree_eq_zero_of_isUnit hf)
#align polynomial.factor_dvd_of_degree_ne_zero Polynomial.factor_dvd_of_degree_ne_zero
theorem factor_dvd_of_natDegree_ne_zero {f : K[X]} (hf : f.natDegree ≠ 0) : factor f ∣ f :=
factor_dvd_of_degree_ne_zero (mt natDegree_eq_of_degree_eq_some hf)
#align polynomial.factor_dvd_of_nat_degree_ne_zero Polynomial.factor_dvd_of_natDegree_ne_zero
def removeFactor (f : K[X]) : Polynomial (AdjoinRoot <| factor f) :=
map (AdjoinRoot.of f.factor) f /ₘ (X - C (AdjoinRoot.root f.factor))
#align polynomial.remove_factor Polynomial.removeFactor
| Mathlib/FieldTheory/SplittingField/Construction.lean | 88 | 93 | theorem X_sub_C_mul_removeFactor (f : K[X]) (hf : f.natDegree ≠ 0) :
(X - C (AdjoinRoot.root f.factor)) * f.removeFactor = map (AdjoinRoot.of f.factor) f := by |
let ⟨g, hg⟩ := factor_dvd_of_natDegree_ne_zero hf
apply (mul_divByMonic_eq_iff_isRoot
(R := AdjoinRoot f.factor) (a := AdjoinRoot.root f.factor)).mpr
rw [IsRoot.def, eval_map, hg, eval₂_mul, ← hg, AdjoinRoot.eval₂_root, zero_mul]
|
namespace Nat
@[reducible] def Coprime (m n : Nat) : Prop := gcd m n = 1
instance (m n : Nat) : Decidable (Coprime m n) := inferInstanceAs (Decidable (_ = 1))
theorem coprime_iff_gcd_eq_one : Coprime m n ↔ gcd m n = 1 := .rfl
theorem Coprime.gcd_eq_one : Coprime m n → gcd m n = 1 := id
theorem Coprime.symm : Coprime n m → Coprime m n := (gcd_comm m n).trans
theorem coprime_comm : Coprime n m ↔ Coprime m n := ⟨Coprime.symm, Coprime.symm⟩
theorem Coprime.dvd_of_dvd_mul_right (H1 : Coprime k n) (H2 : k ∣ m * n) : k ∣ m := by
let t := dvd_gcd (Nat.dvd_mul_left k m) H2
rwa [gcd_mul_left, H1.gcd_eq_one, Nat.mul_one] at t
theorem Coprime.dvd_of_dvd_mul_left (H1 : Coprime k m) (H2 : k ∣ m * n) : k ∣ n :=
H1.dvd_of_dvd_mul_right (by rwa [Nat.mul_comm])
theorem Coprime.gcd_mul_left_cancel (m : Nat) (H : Coprime k n) : gcd (k * m) n = gcd m n :=
have H1 : Coprime (gcd (k * m) n) k := by
rw [Coprime, Nat.gcd_assoc, H.symm.gcd_eq_one, gcd_one_right]
Nat.dvd_antisymm
(dvd_gcd (H1.dvd_of_dvd_mul_left (gcd_dvd_left _ _)) (gcd_dvd_right _ _))
(gcd_dvd_gcd_mul_left _ _ _)
theorem Coprime.gcd_mul_right_cancel (m : Nat) (H : Coprime k n) : gcd (m * k) n = gcd m n := by
rw [Nat.mul_comm m k, H.gcd_mul_left_cancel m]
theorem Coprime.gcd_mul_left_cancel_right (n : Nat)
(H : Coprime k m) : gcd m (k * n) = gcd m n := by
rw [gcd_comm m n, gcd_comm m (k * n), H.gcd_mul_left_cancel n]
| .lake/packages/batteries/Batteries/Data/Nat/Gcd.lean | 53 | 55 | theorem Coprime.gcd_mul_right_cancel_right (n : Nat)
(H : Coprime k m) : gcd m (n * k) = gcd m n := by |
rw [Nat.mul_comm n k, H.gcd_mul_left_cancel_right n]
|
import Mathlib.RingTheory.Polynomial.Cyclotomic.Basic
import Mathlib.RingTheory.RootsOfUnity.Minpoly
#align_import ring_theory.polynomial.cyclotomic.roots from "leanprover-community/mathlib"@"7fdeecc0d03cd40f7a165e6cf00a4d2286db599f"
namespace Polynomial
variable {R : Type*} [CommRing R] {n : ℕ}
theorem isRoot_of_unity_of_root_cyclotomic {ζ : R} {i : ℕ} (hi : i ∈ n.divisors)
(h : (cyclotomic i R).IsRoot ζ) : ζ ^ n = 1 := by
rcases n.eq_zero_or_pos with (rfl | hn)
· exact pow_zero _
have := congr_arg (eval ζ) (prod_cyclotomic_eq_X_pow_sub_one hn R).symm
rw [eval_sub, eval_pow, eval_X, eval_one] at this
convert eq_add_of_sub_eq' this
convert (add_zero (M := R) _).symm
apply eval_eq_zero_of_dvd_of_eval_eq_zero _ h
exact Finset.dvd_prod_of_mem _ hi
#align polynomial.is_root_of_unity_of_root_cyclotomic Polynomial.isRoot_of_unity_of_root_cyclotomic
section IsDomain
variable [IsDomain R]
theorem _root_.isRoot_of_unity_iff (h : 0 < n) (R : Type*) [CommRing R] [IsDomain R] {ζ : R} :
ζ ^ n = 1 ↔ ∃ i ∈ n.divisors, (cyclotomic i R).IsRoot ζ := by
rw [← mem_nthRoots h, nthRoots, mem_roots <| X_pow_sub_C_ne_zero h _, C_1, ←
prod_cyclotomic_eq_X_pow_sub_one h, isRoot_prod]
#align is_root_of_unity_iff isRoot_of_unity_iff
theorem _root_.IsPrimitiveRoot.isRoot_cyclotomic (hpos : 0 < n) {μ : R} (h : IsPrimitiveRoot μ n) :
IsRoot (cyclotomic n R) μ := by
rw [← mem_roots (cyclotomic_ne_zero n R), cyclotomic_eq_prod_X_sub_primitiveRoots h,
roots_prod_X_sub_C, ← Finset.mem_def]
rwa [← mem_primitiveRoots hpos] at h
#align is_primitive_root.is_root_cyclotomic IsPrimitiveRoot.isRoot_cyclotomic
private theorem isRoot_cyclotomic_iff' {n : ℕ} {K : Type*} [Field K] {μ : K} [NeZero (n : K)] :
IsRoot (cyclotomic n K) μ ↔ IsPrimitiveRoot μ n := by
-- in this proof, `o` stands for `orderOf μ`
have hnpos : 0 < n := (NeZero.of_neZero_natCast K).out.bot_lt
refine ⟨fun hμ => ?_, IsPrimitiveRoot.isRoot_cyclotomic hnpos⟩
have hμn : μ ^ n = 1 := by
rw [isRoot_of_unity_iff hnpos _]
exact ⟨n, n.mem_divisors_self hnpos.ne', hμ⟩
by_contra hnμ
have ho : 0 < orderOf μ := (isOfFinOrder_iff_pow_eq_one.2 <| ⟨n, hnpos, hμn⟩).orderOf_pos
have := pow_orderOf_eq_one μ
rw [isRoot_of_unity_iff ho] at this
obtain ⟨i, hio, hiμ⟩ := this
replace hio := Nat.dvd_of_mem_divisors hio
rw [IsPrimitiveRoot.not_iff] at hnμ
rw [← orderOf_dvd_iff_pow_eq_one] at hμn
have key : i < n := (Nat.le_of_dvd ho hio).trans_lt ((Nat.le_of_dvd hnpos hμn).lt_of_ne hnμ)
have key' : i ∣ n := hio.trans hμn
rw [← Polynomial.dvd_iff_isRoot] at hμ hiμ
have hni : {i, n} ⊆ n.divisors := by simpa [Finset.insert_subset_iff, key'] using hnpos.ne'
obtain ⟨k, hk⟩ := hiμ
obtain ⟨j, hj⟩ := hμ
have := prod_cyclotomic_eq_X_pow_sub_one hnpos K
rw [← Finset.prod_sdiff hni, Finset.prod_pair key.ne, hk, hj] at this
have hn := (X_pow_sub_one_separable_iff.mpr <| NeZero.natCast_ne n K).squarefree
rw [← this, Squarefree] at hn
specialize hn (X - C μ) ⟨(∏ x ∈ n.divisors \ {i, n}, cyclotomic x K) * k * j, by ring⟩
simp [Polynomial.isUnit_iff_degree_eq_zero] at hn
theorem isRoot_cyclotomic_iff [NeZero (n : R)] {μ : R} :
IsRoot (cyclotomic n R) μ ↔ IsPrimitiveRoot μ n := by
have hf : Function.Injective _ := IsFractionRing.injective R (FractionRing R)
haveI : NeZero (n : FractionRing R) := NeZero.nat_of_injective hf
rw [← isRoot_map_iff hf, ← IsPrimitiveRoot.map_iff_of_injective hf, map_cyclotomic, ←
isRoot_cyclotomic_iff']
#align polynomial.is_root_cyclotomic_iff Polynomial.isRoot_cyclotomic_iff
theorem roots_cyclotomic_nodup [NeZero (n : R)] : (cyclotomic n R).roots.Nodup := by
obtain h | ⟨ζ, hζ⟩ := (cyclotomic n R).roots.empty_or_exists_mem
· exact h.symm ▸ Multiset.nodup_zero
rw [mem_roots <| cyclotomic_ne_zero n R, isRoot_cyclotomic_iff] at hζ
refine Multiset.nodup_of_le
(roots.le_of_dvd (X_pow_sub_C_ne_zero (NeZero.pos_of_neZero_natCast R) 1) <|
cyclotomic.dvd_X_pow_sub_one n R) hζ.nthRoots_one_nodup
#align polynomial.roots_cyclotomic_nodup Polynomial.roots_cyclotomic_nodup
| Mathlib/RingTheory/Polynomial/Cyclotomic/Roots.lean | 116 | 124 | theorem cyclotomic.roots_to_finset_eq_primitiveRoots [NeZero (n : R)] :
(⟨(cyclotomic n R).roots, roots_cyclotomic_nodup⟩ : Finset _) = primitiveRoots n R := by |
ext a
-- Porting note: was
-- `simp [cyclotomic_ne_zero n R, isRoot_cyclotomic_iff, mem_primitiveRoots,`
-- ` NeZero.pos_of_neZero_natCast R]`
simp only [mem_primitiveRoots, NeZero.pos_of_neZero_natCast R]
convert isRoot_cyclotomic_iff (n := n) (μ := a)
simp [cyclotomic_ne_zero n R]
|
import Mathlib.FieldTheory.IsAlgClosed.AlgebraicClosure
import Mathlib.RingTheory.IntegralDomain
#align_import field_theory.primitive_element from "leanprover-community/mathlib"@"df76f43357840485b9d04ed5dee5ab115d420e87"
noncomputable section
open scoped Classical Polynomial
open FiniteDimensional Polynomial IntermediateField
namespace Field
section PrimitiveElementInf
variable {F : Type*} [Field F] [Infinite F] {E : Type*} [Field E] (ϕ : F →+* E) (α β : E)
theorem primitive_element_inf_aux_exists_c (f g : F[X]) :
∃ c : F, ∀ α' ∈ (f.map ϕ).roots, ∀ β' ∈ (g.map ϕ).roots, -(α' - α) / (β' - β) ≠ ϕ c := by
let sf := (f.map ϕ).roots
let sg := (g.map ϕ).roots
let s := (sf.bind fun α' => sg.map fun β' => -(α' - α) / (β' - β)).toFinset
let s' := s.preimage ϕ fun x _ y _ h => ϕ.injective h
obtain ⟨c, hc⟩ := Infinite.exists_not_mem_finset s'
simp_rw [s', s, Finset.mem_preimage, Multiset.mem_toFinset, Multiset.mem_bind, Multiset.mem_map]
at hc
push_neg at hc
exact ⟨c, hc⟩
#align field.primitive_element_inf_aux_exists_c Field.primitive_element_inf_aux_exists_c
variable (F)
variable [Algebra F E]
| Mathlib/FieldTheory/PrimitiveElement.lean | 104 | 173 | theorem primitive_element_inf_aux [IsSeparable F E] : ∃ γ : E, F⟮α, β⟯ = F⟮γ⟯ := by |
have hα := IsSeparable.isIntegral F α
have hβ := IsSeparable.isIntegral F β
let f := minpoly F α
let g := minpoly F β
let ιFE := algebraMap F E
let ιEE' := algebraMap E (SplittingField (g.map ιFE))
obtain ⟨c, hc⟩ := primitive_element_inf_aux_exists_c (ιEE'.comp ιFE) (ιEE' α) (ιEE' β) f g
let γ := α + c • β
suffices β_in_Fγ : β ∈ F⟮γ⟯ by
use γ
apply le_antisymm
· rw [adjoin_le_iff]
have α_in_Fγ : α ∈ F⟮γ⟯ := by
rw [← add_sub_cancel_right α (c • β)]
exact F⟮γ⟯.sub_mem (mem_adjoin_simple_self F γ) (F⟮γ⟯.toSubalgebra.smul_mem β_in_Fγ c)
rintro x (rfl | rfl) <;> assumption
· rw [adjoin_simple_le_iff]
have α_in_Fαβ : α ∈ F⟮α, β⟯ := subset_adjoin F {α, β} (Set.mem_insert α {β})
have β_in_Fαβ : β ∈ F⟮α, β⟯ := subset_adjoin F {α, β} (Set.mem_insert_of_mem α rfl)
exact F⟮α, β⟯.add_mem α_in_Fαβ (F⟮α, β⟯.smul_mem β_in_Fαβ)
let p := EuclideanDomain.gcd ((f.map (algebraMap F F⟮γ⟯)).comp
(C (AdjoinSimple.gen F γ) - (C ↑c : F⟮γ⟯[X]) * X)) (g.map (algebraMap F F⟮γ⟯))
let h := EuclideanDomain.gcd ((f.map ιFE).comp (C γ - C (ιFE c) * X)) (g.map ιFE)
have map_g_ne_zero : g.map ιFE ≠ 0 := map_ne_zero (minpoly.ne_zero hβ)
have h_ne_zero : h ≠ 0 :=
mt EuclideanDomain.gcd_eq_zero_iff.mp (not_and.mpr fun _ => map_g_ne_zero)
suffices p_linear : p.map (algebraMap F⟮γ⟯ E) = C h.leadingCoeff * (X - C β) by
have finale : β = algebraMap F⟮γ⟯ E (-p.coeff 0 / p.coeff 1) := by
rw [map_div₀, RingHom.map_neg, ← coeff_map, ← coeff_map, p_linear]
-- Porting note: had to add `-map_add` to avoid going in the wrong direction.
simp [mul_sub, coeff_C, mul_div_cancel_left₀ β (mt leadingCoeff_eq_zero.mp h_ne_zero),
-map_add]
-- Porting note: an alternative solution is:
-- simp_rw [Polynomial.coeff_C_mul, Polynomial.coeff_sub, mul_sub,
-- Polynomial.coeff_X_zero, Polynomial.coeff_X_one, mul_zero, mul_one, zero_sub, neg_neg,
-- Polynomial.coeff_C, eq_self_iff_true, Nat.one_ne_zero, if_true, if_false, mul_zero,
-- sub_zero, mul_div_cancel_left β (mt leadingCoeff_eq_zero.mp h_ne_zero)]
rw [finale]
exact Subtype.mem (-p.coeff 0 / p.coeff 1)
have h_sep : h.Separable := separable_gcd_right _ (IsSeparable.separable F β).map
have h_root : h.eval β = 0 := by
apply eval_gcd_eq_zero
· rw [eval_comp, eval_sub, eval_mul, eval_C, eval_C, eval_X, eval_map, ← aeval_def, ←
Algebra.smul_def, add_sub_cancel_right, minpoly.aeval]
· rw [eval_map, ← aeval_def, minpoly.aeval]
have h_splits : Splits ιEE' h :=
splits_of_splits_gcd_right ιEE' map_g_ne_zero (SplittingField.splits _)
have h_roots : ∀ x ∈ (h.map ιEE').roots, x = ιEE' β := by
intro x hx
rw [mem_roots_map h_ne_zero] at hx
specialize hc (ιEE' γ - ιEE' (ιFE c) * x) (by
have f_root := root_left_of_root_gcd hx
rw [eval₂_comp, eval₂_sub, eval₂_mul, eval₂_C, eval₂_C, eval₂_X, eval₂_map] at f_root
exact (mem_roots_map (minpoly.ne_zero hα)).mpr f_root)
specialize hc x (by
rw [mem_roots_map (minpoly.ne_zero hβ), ← eval₂_map]
exact root_right_of_root_gcd hx)
by_contra a
apply hc
apply (div_eq_iff (sub_ne_zero.mpr a)).mpr
simp only [γ, Algebra.smul_def, RingHom.map_add, RingHom.map_mul, RingHom.comp_apply]
ring
rw [← eq_X_sub_C_of_separable_of_root_eq h_sep h_root h_splits h_roots]
trans EuclideanDomain.gcd (?_ : E[X]) (?_ : E[X])
· dsimp only [γ]
convert (gcd_map (algebraMap F⟮γ⟯ E)).symm
· simp only [map_comp, Polynomial.map_map, ← IsScalarTower.algebraMap_eq, Polynomial.map_sub,
map_C, AdjoinSimple.algebraMap_gen, map_add, Polynomial.map_mul, map_X]
congr
|
import Mathlib.Data.Set.Image
import Mathlib.Order.Interval.Set.Basic
#align_import data.set.intervals.with_bot_top from "leanprover-community/mathlib"@"d012cd09a9b256d870751284dd6a29882b0be105"
open Set
variable {α : Type*}
namespace WithTop
@[simp]
theorem preimage_coe_top : (some : α → WithTop α) ⁻¹' {⊤} = (∅ : Set α) :=
eq_empty_of_subset_empty fun _ => coe_ne_top
#align with_top.preimage_coe_top WithTop.preimage_coe_top
variable [Preorder α] {a b : α}
theorem range_coe : range (some : α → WithTop α) = Iio ⊤ := by
ext x
rw [mem_Iio, WithTop.lt_top_iff_ne_top, mem_range, ne_top_iff_exists]
#align with_top.range_coe WithTop.range_coe
@[simp]
theorem preimage_coe_Ioi : (some : α → WithTop α) ⁻¹' Ioi a = Ioi a :=
ext fun _ => coe_lt_coe
#align with_top.preimage_coe_Ioi WithTop.preimage_coe_Ioi
@[simp]
theorem preimage_coe_Ici : (some : α → WithTop α) ⁻¹' Ici a = Ici a :=
ext fun _ => coe_le_coe
#align with_top.preimage_coe_Ici WithTop.preimage_coe_Ici
@[simp]
theorem preimage_coe_Iio : (some : α → WithTop α) ⁻¹' Iio a = Iio a :=
ext fun _ => coe_lt_coe
#align with_top.preimage_coe_Iio WithTop.preimage_coe_Iio
@[simp]
theorem preimage_coe_Iic : (some : α → WithTop α) ⁻¹' Iic a = Iic a :=
ext fun _ => coe_le_coe
#align with_top.preimage_coe_Iic WithTop.preimage_coe_Iic
@[simp]
theorem preimage_coe_Icc : (some : α → WithTop α) ⁻¹' Icc a b = Icc a b := by simp [← Ici_inter_Iic]
#align with_top.preimage_coe_Icc WithTop.preimage_coe_Icc
@[simp]
theorem preimage_coe_Ico : (some : α → WithTop α) ⁻¹' Ico a b = Ico a b := by simp [← Ici_inter_Iio]
#align with_top.preimage_coe_Ico WithTop.preimage_coe_Ico
@[simp]
theorem preimage_coe_Ioc : (some : α → WithTop α) ⁻¹' Ioc a b = Ioc a b := by simp [← Ioi_inter_Iic]
#align with_top.preimage_coe_Ioc WithTop.preimage_coe_Ioc
@[simp]
| Mathlib/Order/Interval/Set/WithBotTop.lean | 71 | 71 | theorem preimage_coe_Ioo : (some : α → WithTop α) ⁻¹' Ioo a b = Ioo a b := by | simp [← Ioi_inter_Iio]
|
import Mathlib.Tactic.Qify
import Mathlib.Data.ZMod.Basic
import Mathlib.NumberTheory.DiophantineApproximation
import Mathlib.NumberTheory.Zsqrtd.Basic
#align_import number_theory.pell from "leanprover-community/mathlib"@"7ad820c4997738e2f542f8a20f32911f52020e26"
namespace Pell
open Zsqrtd
theorem is_pell_solution_iff_mem_unitary {d : ℤ} {a : ℤ√d} :
a.re ^ 2 - d * a.im ^ 2 = 1 ↔ a ∈ unitary (ℤ√d) := by
rw [← norm_eq_one_iff_mem_unitary, norm_def, sq, sq, ← mul_assoc]
#align pell.is_pell_solution_iff_mem_unitary Pell.is_pell_solution_iff_mem_unitary
-- We use `solution₁ d` to allow for a more general structure `solution d m` that
-- encodes solutions to `x^2 - d*y^2 = m` to be added later.
def Solution₁ (d : ℤ) : Type :=
↥(unitary (ℤ√d))
#align pell.solution₁ Pell.Solution₁
section Existence
variable {d : ℤ}
open Set Real
| Mathlib/NumberTheory/Pell.lean | 367 | 434 | theorem exists_of_not_isSquare (h₀ : 0 < d) (hd : ¬IsSquare d) :
∃ x y : ℤ, x ^ 2 - d * y ^ 2 = 1 ∧ y ≠ 0 := by |
let ξ : ℝ := √d
have hξ : Irrational ξ := by
refine irrational_nrt_of_notint_nrt 2 d (sq_sqrt <| Int.cast_nonneg.mpr h₀.le) ?_ two_pos
rintro ⟨x, hx⟩
refine hd ⟨x, @Int.cast_injective ℝ _ _ d (x * x) ?_⟩
rw [← sq_sqrt <| Int.cast_nonneg.mpr h₀.le, Int.cast_mul, ← hx, sq]
obtain ⟨M, hM₁⟩ := exists_int_gt (2 * |ξ| + 1)
have hM : {q : ℚ | |q.1 ^ 2 - d * (q.2 : ℤ) ^ 2| < M}.Infinite := by
refine Infinite.mono (fun q h => ?_) (infinite_rat_abs_sub_lt_one_div_den_sq_of_irrational hξ)
have h0 : 0 < (q.2 : ℝ) ^ 2 := pow_pos (Nat.cast_pos.mpr q.pos) 2
have h1 : (q.num : ℝ) / (q.den : ℝ) = q := mod_cast q.num_div_den
rw [mem_setOf, abs_sub_comm, ← @Int.cast_lt ℝ, ← div_lt_div_right (abs_pos_of_pos h0)]
push_cast
rw [← abs_div, abs_sq, sub_div, mul_div_cancel_right₀ _ h0.ne', ← div_pow, h1, ←
sq_sqrt (Int.cast_pos.mpr h₀).le, sq_sub_sq, abs_mul, ← mul_one_div]
refine mul_lt_mul'' (((abs_add ξ q).trans ?_).trans_lt hM₁) h (abs_nonneg _) (abs_nonneg _)
rw [two_mul, add_assoc, add_le_add_iff_left, ← sub_le_iff_le_add']
rw [mem_setOf, abs_sub_comm] at h
refine (abs_sub_abs_le_abs_sub (q : ℝ) ξ).trans (h.le.trans ?_)
rw [div_le_one h0, one_le_sq_iff_one_le_abs, Nat.abs_cast, Nat.one_le_cast]
exact q.pos
obtain ⟨m, hm⟩ : ∃ m : ℤ, {q : ℚ | q.1 ^ 2 - d * (q.den : ℤ) ^ 2 = m}.Infinite := by
contrapose! hM
simp only [not_infinite] at hM ⊢
refine (congr_arg _ (ext fun x => ?_)).mp (Finite.biUnion (finite_Ioo (-M) M) fun m _ => hM m)
simp only [abs_lt, mem_setOf, mem_Ioo, mem_iUnion, exists_prop, exists_eq_right']
have hm₀ : m ≠ 0 := by
rintro rfl
obtain ⟨q, hq⟩ := hm.nonempty
rw [mem_setOf, sub_eq_zero, mul_comm] at hq
obtain ⟨a, ha⟩ := (Int.pow_dvd_pow_iff two_ne_zero).mp ⟨d, hq⟩
rw [ha, mul_pow, mul_right_inj' (pow_pos (Int.natCast_pos.mpr q.pos) 2).ne'] at hq
exact hd ⟨a, sq a ▸ hq.symm⟩
haveI := neZero_iff.mpr (Int.natAbs_ne_zero.mpr hm₀)
let f : ℚ → ZMod m.natAbs × ZMod m.natAbs := fun q => (q.num, q.den)
obtain ⟨q₁, h₁ : q₁.num ^ 2 - d * (q₁.den : ℤ) ^ 2 = m,
q₂, h₂ : q₂.num ^ 2 - d * (q₂.den : ℤ) ^ 2 = m, hne, hqf⟩ :=
hm.exists_ne_map_eq_of_mapsTo (mapsTo_univ f _) finite_univ
obtain ⟨hq1 : (q₁.num : ZMod m.natAbs) = q₂.num, hq2 : (q₁.den : ZMod m.natAbs) = q₂.den⟩ :=
Prod.ext_iff.mp hqf
have hd₁ : m ∣ q₁.num * q₂.num - d * (q₁.den * q₂.den) := by
rw [← Int.natAbs_dvd, ← ZMod.intCast_zmod_eq_zero_iff_dvd]
push_cast
rw [hq1, hq2, ← sq, ← sq]
norm_cast
rw [ZMod.intCast_zmod_eq_zero_iff_dvd, Int.natAbs_dvd, Nat.cast_pow, ← h₂]
have hd₂ : m ∣ q₁.num * q₂.den - q₂.num * q₁.den := by
rw [← Int.natAbs_dvd, ← ZMod.intCast_eq_intCast_iff_dvd_sub]
push_cast
rw [hq1, hq2]
replace hm₀ : (m : ℚ) ≠ 0 := Int.cast_ne_zero.mpr hm₀
refine ⟨(q₁.num * q₂.num - d * (q₁.den * q₂.den)) / m, (q₁.num * q₂.den - q₂.num * q₁.den) / m,
?_, ?_⟩
· qify [hd₁, hd₂]
field_simp [hm₀]
norm_cast
conv_rhs =>
rw [sq]
congr
· rw [← h₁]
· rw [← h₂]
push_cast
ring
· qify [hd₂]
refine div_ne_zero_iff.mpr ⟨?_, hm₀⟩
exact mod_cast mt sub_eq_zero.mp (mt Rat.eq_iff_mul_eq_mul.mpr hne)
|
import Mathlib.LinearAlgebra.LinearIndependent
#align_import linear_algebra.dimension from "leanprover-community/mathlib"@"47a5f8186becdbc826190ced4312f8199f9db6a5"
noncomputable section
universe w w' u u' v v'
variable {R : Type u} {R' : Type u'} {M M₁ : Type v} {M' : Type v'}
open Cardinal Submodule Function Set
section Module
section
variable [Semiring R] [AddCommMonoid M] [Module R M]
variable (R M)
protected irreducible_def Module.rank : Cardinal :=
⨆ ι : { s : Set M // LinearIndependent R ((↑) : s → M) }, (#ι.1)
#align module.rank Module.rank
theorem rank_le_card : Module.rank R M ≤ #M :=
(Module.rank_def _ _).trans_le (ciSup_le' fun _ ↦ mk_set_le _)
lemma nonempty_linearIndependent_set : Nonempty {s : Set M // LinearIndependent R ((↑) : s → M)} :=
⟨⟨∅, linearIndependent_empty _ _⟩⟩
end
variable [Ring R] [Ring R'] [AddCommGroup M] [AddCommGroup M'] [AddCommGroup M₁]
variable [Module R M] [Module R M'] [Module R M₁] [Module R' M'] [Module R' M₁]
namespace LinearIndependent
variable [Nontrivial R]
| Mathlib/LinearAlgebra/Dimension/Basic.lean | 79 | 84 | theorem cardinal_lift_le_rank {ι : Type w} {v : ι → M}
(hv : LinearIndependent R v) :
Cardinal.lift.{v} #ι ≤ Cardinal.lift.{w} (Module.rank R M) := by |
rw [Module.rank]
refine le_trans ?_ (lift_le.mpr <| le_ciSup (bddAbove_range.{v, v} _) ⟨_, hv.coe_range⟩)
exact lift_mk_le'.mpr ⟨(Equiv.ofInjective _ hv.injective).toEmbedding⟩
|
import Batteries.Data.List.Lemmas
import Batteries.Data.Array.Basic
import Batteries.Tactic.SeqFocus
import Batteries.Util.ProofWanted
namespace Array
theorem forIn_eq_data_forIn [Monad m]
(as : Array α) (b : β) (f : α → β → m (ForInStep β)) :
forIn as b f = forIn as.data b f := by
let rec loop : ∀ {i h b j}, j + i = as.size →
Array.forIn.loop as f i h b = forIn (as.data.drop j) b f
| 0, _, _, _, rfl => by rw [List.drop_length]; rfl
| i+1, _, _, j, ij => by
simp only [forIn.loop, Nat.add]
have j_eq : j = size as - 1 - i := by simp [← ij, ← Nat.add_assoc]
have : as.size - 1 - i < as.size := j_eq ▸ ij ▸ Nat.lt_succ_of_le (Nat.le_add_right ..)
have : as[size as - 1 - i] :: as.data.drop (j + 1) = as.data.drop j := by
rw [j_eq]; exact List.get_cons_drop _ ⟨_, this⟩
simp only [← this, List.forIn_cons]; congr; funext x; congr; funext b
rw [loop (i := i)]; rw [← ij, Nat.succ_add]; rfl
conv => lhs; simp only [forIn, Array.forIn]
rw [loop (Nat.zero_add _)]; rfl
theorem zipWith_eq_zipWith_data (f : α → β → γ) (as : Array α) (bs : Array β) :
(as.zipWith bs f).data = as.data.zipWith f bs.data := by
let rec loop : ∀ (i : Nat) cs, i ≤ as.size → i ≤ bs.size →
(zipWithAux f as bs i cs).data = cs.data ++ (as.data.drop i).zipWith f (bs.data.drop i) := by
intro i cs hia hib
unfold zipWithAux
by_cases h : i = as.size ∨ i = bs.size
case pos =>
have : ¬(i < as.size) ∨ ¬(i < bs.size) := by
cases h <;> simp_all only [Nat.not_lt, Nat.le_refl, true_or, or_true]
-- Cleaned up aesop output below
simp_all only [Nat.not_lt]
cases h <;> [(cases this); (cases this)]
· simp_all only [Nat.le_refl, Nat.lt_irrefl, dite_false, List.drop_length,
List.zipWith_nil_left, List.append_nil]
· simp_all only [Nat.le_refl, Nat.lt_irrefl, dite_false, List.drop_length,
List.zipWith_nil_left, List.append_nil]
· simp_all only [Nat.le_refl, Nat.lt_irrefl, dite_false, List.drop_length,
List.zipWith_nil_right, List.append_nil]
split <;> simp_all only [Nat.not_lt]
· simp_all only [Nat.le_refl, Nat.lt_irrefl, dite_false, List.drop_length,
List.zipWith_nil_right, List.append_nil]
split <;> simp_all only [Nat.not_lt]
case neg =>
rw [not_or] at h
have has : i < as.size := Nat.lt_of_le_of_ne hia h.1
have hbs : i < bs.size := Nat.lt_of_le_of_ne hib h.2
simp only [has, hbs, dite_true]
rw [loop (i+1) _ has hbs, Array.push_data]
have h₁ : [f as[i] bs[i]] = List.zipWith f [as[i]] [bs[i]] := rfl
let i_as : Fin as.data.length := ⟨i, has⟩
let i_bs : Fin bs.data.length := ⟨i, hbs⟩
rw [h₁, List.append_assoc]
congr
rw [← List.zipWith_append (h := by simp), getElem_eq_data_get, getElem_eq_data_get]
show List.zipWith f ((List.get as.data i_as) :: List.drop (i_as + 1) as.data)
((List.get bs.data i_bs) :: List.drop (i_bs + 1) bs.data) =
List.zipWith f (List.drop i as.data) (List.drop i bs.data)
simp only [List.get_cons_drop]
termination_by as.size - i
simp [zipWith, loop 0 #[] (by simp) (by simp)]
theorem size_zipWith (as : Array α) (bs : Array β) (f : α → β → γ) :
(as.zipWith bs f).size = min as.size bs.size := by
rw [size_eq_length_data, zipWith_eq_zipWith_data, List.length_zipWith]
theorem zip_eq_zip_data (as : Array α) (bs : Array β) :
(as.zip bs).data = as.data.zip bs.data :=
zipWith_eq_zipWith_data Prod.mk as bs
theorem size_zip (as : Array α) (bs : Array β) :
(as.zip bs).size = min as.size bs.size :=
as.size_zipWith bs Prod.mk
| .lake/packages/batteries/Batteries/Data/Array/Lemmas.lean | 89 | 92 | theorem size_filter_le (p : α → Bool) (l : Array α) :
(l.filter p).size ≤ l.size := by |
simp only [← data_length, filter_data]
apply List.length_filter_le
|
import Mathlib.Algebra.BigOperators.Group.Multiset
import Mathlib.Data.PNat.Prime
import Mathlib.Data.Nat.Factors
import Mathlib.Data.Multiset.Sort
#align_import data.pnat.factors from "leanprover-community/mathlib"@"e3d9ab8faa9dea8f78155c6c27d62a621f4c152d"
-- Porting note: `deriving` contained Inhabited, CanonicallyOrderedAddCommMonoid, DistribLattice,
-- SemilatticeSup, OrderBot, Sub, OrderedSub
def PrimeMultiset :=
Multiset Nat.Primes deriving Inhabited, CanonicallyOrderedAddCommMonoid, DistribLattice,
SemilatticeSup, Sub
#align prime_multiset PrimeMultiset
instance : OrderBot PrimeMultiset where
bot_le := by simp only [bot_le, forall_const]
instance : OrderedSub PrimeMultiset where
tsub_le_iff_right _ _ _ := Multiset.sub_le_iff_le_add
namespace PrimeMultiset
-- `@[derive]` doesn't work for `meta` instances
unsafe instance : Repr PrimeMultiset := by delta PrimeMultiset; infer_instance
def ofPrime (p : Nat.Primes) : PrimeMultiset :=
({p} : Multiset Nat.Primes)
#align prime_multiset.of_prime PrimeMultiset.ofPrime
theorem card_ofPrime (p : Nat.Primes) : Multiset.card (ofPrime p) = 1 :=
rfl
#align prime_multiset.card_of_prime PrimeMultiset.card_ofPrime
def toNatMultiset : PrimeMultiset → Multiset ℕ := fun v => v.map Coe.coe
#align prime_multiset.to_nat_multiset PrimeMultiset.toNatMultiset
instance coeNat : Coe PrimeMultiset (Multiset ℕ) :=
⟨toNatMultiset⟩
#align prime_multiset.coe_nat PrimeMultiset.coeNat
def coeNatMonoidHom : PrimeMultiset →+ Multiset ℕ :=
{ Multiset.mapAddMonoidHom Coe.coe with toFun := Coe.coe }
#align prime_multiset.coe_nat_monoid_hom PrimeMultiset.coeNatMonoidHom
@[simp]
theorem coe_coeNatMonoidHom : (coeNatMonoidHom : PrimeMultiset → Multiset ℕ) = Coe.coe :=
rfl
#align prime_multiset.coe_coe_nat_monoid_hom PrimeMultiset.coe_coeNatMonoidHom
theorem coeNat_injective : Function.Injective (Coe.coe : PrimeMultiset → Multiset ℕ) :=
Multiset.map_injective Nat.Primes.coe_nat_injective
#align prime_multiset.coe_nat_injective PrimeMultiset.coeNat_injective
theorem coeNat_ofPrime (p : Nat.Primes) : (ofPrime p : Multiset ℕ) = {(p : ℕ)} :=
rfl
#align prime_multiset.coe_nat_of_prime PrimeMultiset.coeNat_ofPrime
theorem coeNat_prime (v : PrimeMultiset) (p : ℕ) (h : p ∈ (v : Multiset ℕ)) : p.Prime := by
rcases Multiset.mem_map.mp h with ⟨⟨_, hp'⟩, ⟨_, h_eq⟩⟩
exact h_eq ▸ hp'
#align prime_multiset.coe_nat_prime PrimeMultiset.coeNat_prime
def toPNatMultiset : PrimeMultiset → Multiset ℕ+ := fun v => v.map Coe.coe
#align prime_multiset.to_pnat_multiset PrimeMultiset.toPNatMultiset
instance coePNat : Coe PrimeMultiset (Multiset ℕ+) :=
⟨toPNatMultiset⟩
#align prime_multiset.coe_pnat PrimeMultiset.coePNat
def coePNatMonoidHom : PrimeMultiset →+ Multiset ℕ+ :=
{ Multiset.mapAddMonoidHom Coe.coe with toFun := Coe.coe }
#align prime_multiset.coe_pnat_monoid_hom PrimeMultiset.coePNatMonoidHom
@[simp]
theorem coe_coePNatMonoidHom : (coePNatMonoidHom : PrimeMultiset → Multiset ℕ+) = Coe.coe :=
rfl
#align prime_multiset.coe_coe_pnat_monoid_hom PrimeMultiset.coe_coePNatMonoidHom
theorem coePNat_injective : Function.Injective (Coe.coe : PrimeMultiset → Multiset ℕ+) :=
Multiset.map_injective Nat.Primes.coe_pnat_injective
#align prime_multiset.coe_pnat_injective PrimeMultiset.coePNat_injective
theorem coePNat_ofPrime (p : Nat.Primes) : (ofPrime p : Multiset ℕ+) = {(p : ℕ+)} :=
rfl
#align prime_multiset.coe_pnat_of_prime PrimeMultiset.coePNat_ofPrime
theorem coePNat_prime (v : PrimeMultiset) (p : ℕ+) (h : p ∈ (v : Multiset ℕ+)) : p.Prime := by
rcases Multiset.mem_map.mp h with ⟨⟨_, hp'⟩, ⟨_, h_eq⟩⟩
exact h_eq ▸ hp'
#align prime_multiset.coe_pnat_prime PrimeMultiset.coePNat_prime
instance coeMultisetPNatNat : Coe (Multiset ℕ+) (Multiset ℕ) :=
⟨fun v => v.map Coe.coe⟩
#align prime_multiset.coe_multiset_pnat_nat PrimeMultiset.coeMultisetPNatNat
| Mathlib/Data/PNat/Factors.lean | 130 | 133 | theorem coePNat_nat (v : PrimeMultiset) : ((v : Multiset ℕ+) : Multiset ℕ) = (v : Multiset ℕ) := by |
change (v.map (Coe.coe : Nat.Primes → ℕ+)).map Subtype.val = v.map Subtype.val
rw [Multiset.map_map]
congr
|
import Mathlib.Data.Set.Image
import Mathlib.Data.SProd
#align_import data.set.prod from "leanprover-community/mathlib"@"48fb5b5280e7c81672afc9524185ae994553ebf4"
open Function
namespace Set
section Prod
variable {α β γ δ : Type*} {s s₁ s₂ : Set α} {t t₁ t₂ : Set β} {a : α} {b : β}
theorem Subsingleton.prod (hs : s.Subsingleton) (ht : t.Subsingleton) :
(s ×ˢ t).Subsingleton := fun _x hx _y hy ↦
Prod.ext (hs hx.1 hy.1) (ht hx.2 hy.2)
noncomputable instance decidableMemProd [DecidablePred (· ∈ s)] [DecidablePred (· ∈ t)] :
DecidablePred (· ∈ s ×ˢ t) := fun _ => And.decidable
#align set.decidable_mem_prod Set.decidableMemProd
@[gcongr]
theorem prod_mono (hs : s₁ ⊆ s₂) (ht : t₁ ⊆ t₂) : s₁ ×ˢ t₁ ⊆ s₂ ×ˢ t₂ :=
fun _ ⟨h₁, h₂⟩ => ⟨hs h₁, ht h₂⟩
#align set.prod_mono Set.prod_mono
@[gcongr]
theorem prod_mono_left (hs : s₁ ⊆ s₂) : s₁ ×ˢ t ⊆ s₂ ×ˢ t :=
prod_mono hs Subset.rfl
#align set.prod_mono_left Set.prod_mono_left
@[gcongr]
theorem prod_mono_right (ht : t₁ ⊆ t₂) : s ×ˢ t₁ ⊆ s ×ˢ t₂ :=
prod_mono Subset.rfl ht
#align set.prod_mono_right Set.prod_mono_right
@[simp]
theorem prod_self_subset_prod_self : s₁ ×ˢ s₁ ⊆ s₂ ×ˢ s₂ ↔ s₁ ⊆ s₂ :=
⟨fun h _ hx => (h (mk_mem_prod hx hx)).1, fun h _ hx => ⟨h hx.1, h hx.2⟩⟩
#align set.prod_self_subset_prod_self Set.prod_self_subset_prod_self
@[simp]
theorem prod_self_ssubset_prod_self : s₁ ×ˢ s₁ ⊂ s₂ ×ˢ s₂ ↔ s₁ ⊂ s₂ :=
and_congr prod_self_subset_prod_self <| not_congr prod_self_subset_prod_self
#align set.prod_self_ssubset_prod_self Set.prod_self_ssubset_prod_self
theorem prod_subset_iff {P : Set (α × β)} : s ×ˢ t ⊆ P ↔ ∀ x ∈ s, ∀ y ∈ t, (x, y) ∈ P :=
⟨fun h _ hx _ hy => h (mk_mem_prod hx hy), fun h ⟨_, _⟩ hp => h _ hp.1 _ hp.2⟩
#align set.prod_subset_iff Set.prod_subset_iff
theorem forall_prod_set {p : α × β → Prop} : (∀ x ∈ s ×ˢ t, p x) ↔ ∀ x ∈ s, ∀ y ∈ t, p (x, y) :=
prod_subset_iff
#align set.forall_prod_set Set.forall_prod_set
| Mathlib/Data/Set/Prod.lean | 79 | 80 | theorem exists_prod_set {p : α × β → Prop} : (∃ x ∈ s ×ˢ t, p x) ↔ ∃ x ∈ s, ∃ y ∈ t, p (x, y) := by |
simp [and_assoc]
|
import Mathlib.Analysis.NormedSpace.PiLp
import Mathlib.Analysis.InnerProductSpace.PiL2
#align_import analysis.matrix from "leanprover-community/mathlib"@"46b633fd842bef9469441c0209906f6dddd2b4f5"
noncomputable section
open scoped NNReal Matrix
namespace Matrix
variable {R l m n α β : Type*} [Fintype l] [Fintype m] [Fintype n]
section LinfLinf
protected def normedAddCommGroup [NormedAddCommGroup α] : NormedAddCommGroup (Matrix m n α) :=
Pi.normedAddCommGroup
#align matrix.normed_add_comm_group Matrix.normedAddCommGroup
section LinftyOp
@[local instance]
protected def linftyOpSeminormedAddCommGroup [SeminormedAddCommGroup α] :
SeminormedAddCommGroup (Matrix m n α) :=
(by infer_instance : SeminormedAddCommGroup (m → PiLp 1 fun j : n => α))
#align matrix.linfty_op_seminormed_add_comm_group Matrix.linftyOpSeminormedAddCommGroup
@[local instance]
protected def linftyOpNormedAddCommGroup [NormedAddCommGroup α] :
NormedAddCommGroup (Matrix m n α) :=
(by infer_instance : NormedAddCommGroup (m → PiLp 1 fun j : n => α))
#align matrix.linfty_op_normed_add_comm_group Matrix.linftyOpNormedAddCommGroup
@[local instance]
protected theorem linftyOpBoundedSMul
[SeminormedRing R] [SeminormedAddCommGroup α] [Module R α] [BoundedSMul R α] :
BoundedSMul R (Matrix m n α) :=
(by infer_instance : BoundedSMul R (m → PiLp 1 fun j : n => α))
@[local instance]
protected def linftyOpNormedSpace [NormedField R] [SeminormedAddCommGroup α] [NormedSpace R α] :
NormedSpace R (Matrix m n α) :=
(by infer_instance : NormedSpace R (m → PiLp 1 fun j : n => α))
#align matrix.linfty_op_normed_space Matrix.linftyOpNormedSpace
section SeminormedAddCommGroup
variable [SeminormedAddCommGroup α]
| Mathlib/Analysis/Matrix.lean | 273 | 277 | theorem linfty_opNorm_def (A : Matrix m n α) :
‖A‖ = ((Finset.univ : Finset m).sup fun i : m => ∑ j : n, ‖A i j‖₊ : ℝ≥0) := by |
-- Porting note: added
change ‖fun i => (WithLp.equiv 1 _).symm (A i)‖ = _
simp [Pi.norm_def, PiLp.nnnorm_eq_sum ENNReal.one_ne_top]
|
import Mathlib.CategoryTheory.Monoidal.Braided.Basic
import Mathlib.CategoryTheory.Monoidal.OfChosenFiniteProducts.Basic
#align_import category_theory.monoidal.of_chosen_finite_products.symmetric from "leanprover-community/mathlib"@"95a87616d63b3cb49d3fe678d416fbe9c4217bf4"
universe v u
namespace CategoryTheory
variable {C : Type u} [Category.{v} C] {X Y : C}
open CategoryTheory.Limits
variable (𝒯 : LimitCone (Functor.empty.{0} C))
variable (ℬ : ∀ X Y : C, LimitCone (pair X Y))
open MonoidalOfChosenFiniteProducts
namespace MonoidalOfChosenFiniteProducts
open MonoidalCategory
theorem braiding_naturality {X X' Y Y' : C} (f : X ⟶ Y) (g : X' ⟶ Y') :
tensorHom ℬ f g ≫ (Limits.BinaryFan.braiding (ℬ Y Y').isLimit (ℬ Y' Y).isLimit).hom =
(Limits.BinaryFan.braiding (ℬ X X').isLimit (ℬ X' X).isLimit).hom ≫ tensorHom ℬ g f := by
dsimp [tensorHom, Limits.BinaryFan.braiding]
apply (ℬ _ _).isLimit.hom_ext
rintro ⟨⟨⟩⟩ <;> · dsimp [Limits.IsLimit.conePointUniqueUpToIso]; simp
#align category_theory.monoidal_of_chosen_finite_products.braiding_naturality CategoryTheory.MonoidalOfChosenFiniteProducts.braiding_naturality
theorem hexagon_forward (X Y Z : C) :
(BinaryFan.associatorOfLimitCone ℬ X Y Z).hom ≫
(Limits.BinaryFan.braiding (ℬ X (tensorObj ℬ Y Z)).isLimit
(ℬ (tensorObj ℬ Y Z) X).isLimit).hom ≫
(BinaryFan.associatorOfLimitCone ℬ Y Z X).hom =
tensorHom ℬ (Limits.BinaryFan.braiding (ℬ X Y).isLimit (ℬ Y X).isLimit).hom (𝟙 Z) ≫
(BinaryFan.associatorOfLimitCone ℬ Y X Z).hom ≫
tensorHom ℬ (𝟙 Y) (Limits.BinaryFan.braiding (ℬ X Z).isLimit (ℬ Z X).isLimit).hom := by
dsimp [tensorHom, Limits.BinaryFan.braiding]
apply (ℬ _ _).isLimit.hom_ext; rintro ⟨⟨⟩⟩
· dsimp [Limits.IsLimit.conePointUniqueUpToIso]; simp
· apply (ℬ _ _).isLimit.hom_ext
rintro ⟨⟨⟩⟩ <;> · dsimp [Limits.IsLimit.conePointUniqueUpToIso]; simp
#align category_theory.monoidal_of_chosen_finite_products.hexagon_forward CategoryTheory.MonoidalOfChosenFiniteProducts.hexagon_forward
theorem hexagon_reverse (X Y Z : C) :
(BinaryFan.associatorOfLimitCone ℬ X Y Z).inv ≫
(Limits.BinaryFan.braiding (ℬ (tensorObj ℬ X Y) Z).isLimit
(ℬ Z (tensorObj ℬ X Y)).isLimit).hom ≫
(BinaryFan.associatorOfLimitCone ℬ Z X Y).inv =
tensorHom ℬ (𝟙 X) (Limits.BinaryFan.braiding (ℬ Y Z).isLimit (ℬ Z Y).isLimit).hom ≫
(BinaryFan.associatorOfLimitCone ℬ X Z Y).inv ≫
tensorHom ℬ (Limits.BinaryFan.braiding (ℬ X Z).isLimit (ℬ Z X).isLimit).hom (𝟙 Y) := by
dsimp [tensorHom, Limits.BinaryFan.braiding]
apply (ℬ _ _).isLimit.hom_ext; rintro ⟨⟨⟩⟩
· apply (ℬ _ _).isLimit.hom_ext
rintro ⟨⟨⟩⟩ <;>
· dsimp [BinaryFan.associatorOfLimitCone, BinaryFan.associator,
Limits.IsLimit.conePointUniqueUpToIso]
simp
· dsimp [BinaryFan.associatorOfLimitCone, BinaryFan.associator,
Limits.IsLimit.conePointUniqueUpToIso]
simp
#align category_theory.monoidal_of_chosen_finite_products.hexagon_reverse CategoryTheory.MonoidalOfChosenFiniteProducts.hexagon_reverse
| Mathlib/CategoryTheory/Monoidal/OfChosenFiniteProducts/Symmetric.lean | 77 | 83 | theorem symmetry (X Y : C) :
(Limits.BinaryFan.braiding (ℬ X Y).isLimit (ℬ Y X).isLimit).hom ≫
(Limits.BinaryFan.braiding (ℬ Y X).isLimit (ℬ X Y).isLimit).hom =
𝟙 (tensorObj ℬ X Y) := by |
dsimp [tensorHom, Limits.BinaryFan.braiding]
apply (ℬ _ _).isLimit.hom_ext;
rintro ⟨⟨⟩⟩ <;> · dsimp [Limits.IsLimit.conePointUniqueUpToIso]; simp
|
import Mathlib.LinearAlgebra.AffineSpace.AffineEquiv
#align_import linear_algebra.affine_space.affine_subspace from "leanprover-community/mathlib"@"e96bdfbd1e8c98a09ff75f7ac6204d142debc840"
noncomputable section
open Affine
open Set
section
variable (k : Type*) {V : Type*} {P : Type*} [Ring k] [AddCommGroup V] [Module k V]
variable [AffineSpace V P]
def vectorSpan (s : Set P) : Submodule k V :=
Submodule.span k (s -ᵥ s)
#align vector_span vectorSpan
theorem vectorSpan_def (s : Set P) : vectorSpan k s = Submodule.span k (s -ᵥ s) :=
rfl
#align vector_span_def vectorSpan_def
theorem vectorSpan_mono {s₁ s₂ : Set P} (h : s₁ ⊆ s₂) : vectorSpan k s₁ ≤ vectorSpan k s₂ :=
Submodule.span_mono (vsub_self_mono h)
#align vector_span_mono vectorSpan_mono
variable (P)
@[simp]
| Mathlib/LinearAlgebra/AffineSpace/AffineSubspace.lean | 78 | 79 | theorem vectorSpan_empty : vectorSpan k (∅ : Set P) = (⊥ : Submodule k V) := by |
rw [vectorSpan_def, vsub_empty, Submodule.span_empty]
|
import Mathlib.CategoryTheory.Adjunction.Opposites
import Mathlib.CategoryTheory.Comma.Presheaf
import Mathlib.CategoryTheory.Elements
import Mathlib.CategoryTheory.Limits.ConeCategory
import Mathlib.CategoryTheory.Limits.Final
import Mathlib.CategoryTheory.Limits.KanExtension
import Mathlib.CategoryTheory.Limits.Over
#align_import category_theory.limits.presheaf from "leanprover-community/mathlib"@"70fd9563a21e7b963887c9360bd29b2393e6225a"
namespace CategoryTheory
open Category Limits
universe v₁ v₂ u₁ u₂
section SmallCategory
variable {C : Type u₁} [SmallCategory C]
variable {ℰ : Type u₂} [Category.{u₁} ℰ]
variable (A : C ⥤ ℰ)
namespace ColimitAdj
@[simps!]
def restrictedYoneda : ℰ ⥤ Cᵒᵖ ⥤ Type u₁ :=
yoneda ⋙ (whiskeringLeft _ _ (Type u₁)).obj (Functor.op A)
#align category_theory.colimit_adj.restricted_yoneda CategoryTheory.ColimitAdj.restrictedYoneda
def restrictedYonedaYoneda : restrictedYoneda (yoneda : C ⥤ Cᵒᵖ ⥤ Type u₁) ≅ 𝟭 _ :=
NatIso.ofComponents fun P =>
NatIso.ofComponents (fun X => Equiv.toIso yonedaEquiv) @ fun X Y f =>
funext fun x => by
dsimp [yonedaEquiv]
have : x.app X (CategoryStruct.id (Opposite.unop X)) =
(x.app X (𝟙 (Opposite.unop X))) := rfl
rw [this]
rw [← FunctorToTypes.naturality _ _ x f (𝟙 _)]
simp only [id_comp, Functor.op_obj, Opposite.unop_op, yoneda_obj_map, comp_id]
#align category_theory.colimit_adj.restricted_yoneda_yoneda CategoryTheory.ColimitAdj.restrictedYonedaYoneda
def restrictYonedaHomEquiv (P : Cᵒᵖ ⥤ Type u₁) (E : ℰ)
{c : Cocone ((CategoryOfElements.π P).leftOp ⋙ A)} (t : IsColimit c) :
(c.pt ⟶ E) ≃ (P ⟶ (restrictedYoneda A).obj E) :=
((uliftTrivial _).symm ≪≫ t.homIso' E).toEquiv.trans
{ toFun := fun k =>
{ app := fun c p => k.1 (Opposite.op ⟨_, p⟩)
naturality := fun c c' f =>
funext fun p =>
(k.2
(Quiver.Hom.op ⟨f, rfl⟩ :
(Opposite.op ⟨c', P.map f p⟩ : P.Elementsᵒᵖ) ⟶ Opposite.op ⟨c, p⟩)).symm }
invFun := fun τ =>
{ val := fun p => τ.app p.unop.1 p.unop.2
property := @fun p p' f => by
simp_rw [← f.unop.2]
apply (congr_fun (τ.naturality f.unop.1) p'.unop.2).symm }
left_inv := by
rintro ⟨k₁, k₂⟩
ext
dsimp
congr 1
right_inv := by
rintro ⟨_, _⟩
rfl }
#align category_theory.colimit_adj.restrict_yoneda_hom_equiv CategoryTheory.ColimitAdj.restrictYonedaHomEquiv
theorem restrictYonedaHomEquiv_natural (P : Cᵒᵖ ⥤ Type u₁) (E₁ E₂ : ℰ) (g : E₁ ⟶ E₂) {c : Cocone _}
(t : IsColimit c) (k : c.pt ⟶ E₁) :
restrictYonedaHomEquiv A P E₂ t (k ≫ g) =
restrictYonedaHomEquiv A P E₁ t k ≫ (restrictedYoneda A).map g := by
ext x X
apply (assoc _ _ _).symm
#align category_theory.colimit_adj.restrict_yoneda_hom_equiv_natural CategoryTheory.ColimitAdj.restrictYonedaHomEquiv_natural
variable [HasColimits ℰ]
noncomputable def extendAlongYoneda : (Cᵒᵖ ⥤ Type u₁) ⥤ ℰ :=
Adjunction.leftAdjointOfEquiv (fun P E => restrictYonedaHomEquiv A P E (colimit.isColimit _))
fun P E E' g => restrictYonedaHomEquiv_natural A P E E' g _
#align category_theory.colimit_adj.extend_along_yoneda CategoryTheory.ColimitAdj.extendAlongYoneda
@[simp]
theorem extendAlongYoneda_obj (P : Cᵒᵖ ⥤ Type u₁) :
(extendAlongYoneda A).obj P = colimit ((CategoryOfElements.π P).leftOp ⋙ A) :=
rfl
#align category_theory.colimit_adj.extend_along_yoneda_obj CategoryTheory.ColimitAdj.extendAlongYoneda_obj
-- Porting note: adding this lemma because lean 4 ext no longer applies all ext lemmas when
-- stuck (and hence can see through definitional equalities). The previous lemma shows that
-- `(extendAlongYoneda A).obj P` is definitionally a colimit, and the ext lemma is just
-- a special case of `CategoryTheory.Limits.colimit.hom_ext`.
-- See https://github.com/leanprover-community/mathlib4/issues/5229
@[ext] lemma extendAlongYoneda_obj.hom_ext {X : ℰ} {P : Cᵒᵖ ⥤ Type u₁}
{f f' : (extendAlongYoneda A).obj P ⟶ X}
(w : ∀ j, colimit.ι ((CategoryOfElements.π P).leftOp ⋙ A) j ≫ f =
colimit.ι ((CategoryOfElements.π P).leftOp ⋙ A) j ≫ f') : f = f' :=
CategoryTheory.Limits.colimit.hom_ext w
| Mathlib/CategoryTheory/Limits/Presheaf.lean | 158 | 175 | theorem extendAlongYoneda_map {X Y : Cᵒᵖ ⥤ Type u₁} (f : X ⟶ Y) :
(extendAlongYoneda A).map f =
colimit.pre ((CategoryOfElements.π Y).leftOp ⋙ A) (CategoryOfElements.map f).op := by |
ext J
erw [colimit.ι_pre ((CategoryOfElements.π Y).leftOp ⋙ A) (CategoryOfElements.map f).op]
dsimp only [extendAlongYoneda, restrictYonedaHomEquiv, IsColimit.homIso', IsColimit.homIso,
uliftTrivial]
-- Porting note: in mathlib3 the rest of the proof was `simp, refl`; this is squeezed
-- and appropriately reordered, presumably because of a non-confluence issue.
simp only [Adjunction.leftAdjointOfEquiv_map, Iso.symm_mk, Iso.toEquiv_comp, Equiv.coe_trans,
Equiv.coe_fn_mk, Iso.toEquiv_fun, Equiv.symm_trans_apply, Equiv.coe_fn_symm_mk,
Iso.toEquiv_symm_fun, id, colimit.isColimit_desc, colimit.ι_desc, FunctorToTypes.comp,
Cocone.extend_ι, Cocone.extensions_app, Functor.map_id, Category.comp_id, colimit.cocone_ι]
simp only [Functor.comp_obj, Functor.leftOp_obj, CategoryOfElements.π_obj, colimit.cocone_x,
Functor.comp_map, Functor.leftOp_map, CategoryOfElements.π_map, Opposite.unop_op,
Adjunction.leftAdjointOfEquiv_obj, Function.comp_apply, Functor.map_id, comp_id,
colimit.cocone_ι, Functor.op_obj]
rfl
|
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