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import Mathlib.Data.Nat.Multiplicity import Mathlib.Data.ZMod.Algebra import Mathlib.RingTheory.WittVector.Basic import Mathlib.RingTheory.WittVector.IsPoly import Mathlib.FieldTheory.Perfect #align_import ring_theory.witt_vector.frobenius from "leanprover-community/mathlib"@"0723536a0522d24fc2f159a096fb3304bef77472"...
Mathlib/RingTheory/WittVector/Frobenius.lean
71
74
theorem bind₁_frobeniusPolyRat_wittPolynomial (n : ℕ) : bind₁ (frobeniusPolyRat p) (wittPolynomial p ℚ n) = wittPolynomial p ℚ (n + 1) := by
delta frobeniusPolyRat rw [← bind₁_bind₁, bind₁_xInTermsOfW_wittPolynomial, bind₁_X_right, Function.comp_apply]
2,002
import Mathlib.Data.Nat.Multiplicity import Mathlib.Data.ZMod.Algebra import Mathlib.RingTheory.WittVector.Basic import Mathlib.RingTheory.WittVector.IsPoly import Mathlib.FieldTheory.Perfect #align_import ring_theory.witt_vector.frobenius from "leanprover-community/mathlib"@"0723536a0522d24fc2f159a096fb3304bef77472"...
Mathlib/RingTheory/WittVector/Frobenius.lean
97
104
theorem frobeniusPolyAux_eq (n : ℕ) : frobeniusPolyAux p n = X (n + 1) - ∑ i ∈ range n, ∑ j ∈ range (p ^ (n - i)), (X i ^ p) ^ (p ^ (n - i) - (j + 1)) * frobeniusPolyAux p i ^ (j + 1) * C ↑((p ^ (n - i)).choose (j + 1) / p ^ (n - i - v p ⟨j + 1, Nat.succ_pos j⟩) * ...
rw [frobeniusPolyAux, ← Fin.sum_univ_eq_sum_range]
2,002
import Mathlib.Data.Nat.Multiplicity import Mathlib.Data.ZMod.Algebra import Mathlib.RingTheory.WittVector.Basic import Mathlib.RingTheory.WittVector.IsPoly import Mathlib.FieldTheory.Perfect #align_import ring_theory.witt_vector.frobenius from "leanprover-community/mathlib"@"0723536a0522d24fc2f159a096fb3304bef77472"...
Mathlib/RingTheory/WittVector/Frobenius.lean
123
127
theorem map_frobeniusPoly.key₁ (n j : ℕ) (hj : j < p ^ n) : p ^ (n - v p ⟨j + 1, j.succ_pos⟩) ∣ (p ^ n).choose (j + 1) := by
apply multiplicity.pow_dvd_of_le_multiplicity rw [hp.out.multiplicity_choose_prime_pow hj j.succ_ne_zero] rfl
2,002
import Mathlib.Data.Nat.Multiplicity import Mathlib.Data.ZMod.Algebra import Mathlib.RingTheory.WittVector.Basic import Mathlib.RingTheory.WittVector.IsPoly import Mathlib.FieldTheory.Perfect #align_import ring_theory.witt_vector.frobenius from "leanprover-community/mathlib"@"0723536a0522d24fc2f159a096fb3304bef77472"...
Mathlib/RingTheory/WittVector/Frobenius.lean
131
140
theorem map_frobeniusPoly.key₂ {n i j : ℕ} (hi : i ≤ n) (hj : j < p ^ (n - i)) : j - v p ⟨j + 1, j.succ_pos⟩ + n = i + j + (n - i - v p ⟨j + 1, j.succ_pos⟩) := by
generalize h : v p ⟨j + 1, j.succ_pos⟩ = m rsuffices ⟨h₁, h₂⟩ : m ≤ n - i ∧ m ≤ j · rw [tsub_add_eq_add_tsub h₂, add_comm i j, add_tsub_assoc_of_le (h₁.trans (Nat.sub_le n i)), add_assoc, tsub_right_comm, add_comm i, tsub_add_cancel_of_le (le_tsub_of_add_le_right ((le_tsub_iff_left hi).mp h₁))] hav...
2,002
import Mathlib.Data.Nat.Multiplicity import Mathlib.Data.ZMod.Algebra import Mathlib.RingTheory.WittVector.Basic import Mathlib.RingTheory.WittVector.IsPoly import Mathlib.FieldTheory.Perfect #align_import ring_theory.witt_vector.frobenius from "leanprover-community/mathlib"@"0723536a0522d24fc2f159a096fb3304bef77472"...
Mathlib/RingTheory/WittVector/Frobenius.lean
143
193
theorem map_frobeniusPoly (n : ℕ) : MvPolynomial.map (Int.castRingHom ℚ) (frobeniusPoly p n) = frobeniusPolyRat p n := by
rw [frobeniusPoly, RingHom.map_add, RingHom.map_mul, RingHom.map_pow, map_C, map_X, eq_intCast, Int.cast_natCast, frobeniusPolyRat] refine Nat.strong_induction_on n ?_; clear n intro n IH rw [xInTermsOfW_eq] simp only [AlgHom.map_sum, AlgHom.map_sub, AlgHom.map_mul, AlgHom.map_pow, bind₁_C_right] have ...
2,002
import Mathlib.RingTheory.WittVector.Frobenius import Mathlib.RingTheory.WittVector.Verschiebung import Mathlib.RingTheory.WittVector.MulP #align_import ring_theory.witt_vector.identities from "leanprover-community/mathlib"@"0798037604b2d91748f9b43925fb7570a5f3256c" namespace WittVector variable {p : ℕ} {R : Typ...
Mathlib/RingTheory/WittVector/Identities.lean
42
47
theorem frobenius_verschiebung (x : 𝕎 R) : frobenius (verschiebung x) = x * p := by
have : IsPoly p fun {R} [CommRing R] x ↦ frobenius (verschiebung x) := IsPoly.comp (hg := frobenius_isPoly p) (hf := verschiebung_isPoly) have : IsPoly p fun {R} [CommRing R] x ↦ x * p := mulN_isPoly p p ghost_calc x ghost_simp [mul_comm]
2,003
import Mathlib.RingTheory.WittVector.Frobenius import Mathlib.RingTheory.WittVector.Verschiebung import Mathlib.RingTheory.WittVector.MulP #align_import ring_theory.witt_vector.identities from "leanprover-community/mathlib"@"0798037604b2d91748f9b43925fb7570a5f3256c" namespace WittVector variable {p : ℕ} {R : Typ...
Mathlib/RingTheory/WittVector/Identities.lean
51
52
theorem verschiebung_zmod (x : 𝕎 (ZMod p)) : verschiebung x = x * p := by
rw [← frobenius_verschiebung, frobenius_zmodp]
2,003
import Mathlib.RingTheory.WittVector.Frobenius import Mathlib.RingTheory.WittVector.Verschiebung import Mathlib.RingTheory.WittVector.MulP #align_import ring_theory.witt_vector.identities from "leanprover-community/mathlib"@"0798037604b2d91748f9b43925fb7570a5f3256c" namespace WittVector variable {p : ℕ} {R : Typ...
Mathlib/RingTheory/WittVector/Identities.lean
57
61
theorem coeff_p_pow [CharP R p] (i : ℕ) : ((p : 𝕎 R) ^ i).coeff i = 1 := by
induction' i with i h · simp only [Nat.zero_eq, one_coeff_zero, Ne, pow_zero] · rw [pow_succ, ← frobenius_verschiebung, coeff_frobenius_charP, verschiebung_coeff_succ, h, one_pow]
2,003
import Mathlib.RingTheory.WittVector.Frobenius import Mathlib.RingTheory.WittVector.Verschiebung import Mathlib.RingTheory.WittVector.MulP #align_import ring_theory.witt_vector.identities from "leanprover-community/mathlib"@"0798037604b2d91748f9b43925fb7570a5f3256c" namespace WittVector variable {p : ℕ} {R : Typ...
Mathlib/RingTheory/WittVector/Identities.lean
64
71
theorem coeff_p_pow_eq_zero [CharP R p] {i j : ℕ} (hj : j ≠ i) : ((p : 𝕎 R) ^ i).coeff j = 0 := by
induction' i with i hi generalizing j · rw [pow_zero, one_coeff_eq_of_pos] exact Nat.pos_of_ne_zero hj · rw [pow_succ, ← frobenius_verschiebung, coeff_frobenius_charP] cases j · rw [verschiebung_coeff_zero, zero_pow hp.out.ne_zero] · rw [verschiebung_coeff_succ, hi (ne_of_apply_ne _ hj), zero_pow...
2,003
import Mathlib.RingTheory.WittVector.Frobenius import Mathlib.RingTheory.WittVector.Verschiebung import Mathlib.RingTheory.WittVector.MulP #align_import ring_theory.witt_vector.identities from "leanprover-community/mathlib"@"0798037604b2d91748f9b43925fb7570a5f3256c" namespace WittVector variable {p : ℕ} {R : Typ...
Mathlib/RingTheory/WittVector/Identities.lean
74
77
theorem coeff_p [CharP R p] (i : ℕ) : (p : 𝕎 R).coeff i = if i = 1 then 1 else 0 := by
split_ifs with hi · simpa only [hi, pow_one] using coeff_p_pow p R 1 · simpa only [pow_one] using coeff_p_pow_eq_zero p R hi
2,003
import Mathlib.RingTheory.WittVector.Frobenius import Mathlib.RingTheory.WittVector.Verschiebung import Mathlib.RingTheory.WittVector.MulP #align_import ring_theory.witt_vector.identities from "leanprover-community/mathlib"@"0798037604b2d91748f9b43925fb7570a5f3256c" namespace WittVector variable {p : ℕ} {R : Typ...
Mathlib/RingTheory/WittVector/Identities.lean
81
83
theorem coeff_p_zero [CharP R p] : (p : 𝕎 R).coeff 0 = 0 := by
rw [coeff_p, if_neg] exact zero_ne_one
2,003
import Mathlib.RingTheory.WittVector.Frobenius import Mathlib.RingTheory.WittVector.Verschiebung import Mathlib.RingTheory.WittVector.MulP #align_import ring_theory.witt_vector.identities from "leanprover-community/mathlib"@"0798037604b2d91748f9b43925fb7570a5f3256c" namespace WittVector variable {p : ℕ} {R : Typ...
Mathlib/RingTheory/WittVector/Identities.lean
87
87
theorem coeff_p_one [CharP R p] : (p : 𝕎 R).coeff 1 = 1 := by
rw [coeff_p, if_pos rfl]
2,003
import Mathlib.RingTheory.WittVector.Frobenius import Mathlib.RingTheory.WittVector.Verschiebung import Mathlib.RingTheory.WittVector.MulP #align_import ring_theory.witt_vector.identities from "leanprover-community/mathlib"@"0798037604b2d91748f9b43925fb7570a5f3256c" namespace WittVector variable {p : ℕ} {R : Typ...
Mathlib/RingTheory/WittVector/Identities.lean
90
92
theorem p_nonzero [Nontrivial R] [CharP R p] : (p : 𝕎 R) ≠ 0 := by
intro h simpa only [h, zero_coeff, zero_ne_one] using coeff_p_one p R
2,003
import Mathlib.RingTheory.WittVector.Frobenius import Mathlib.RingTheory.WittVector.Verschiebung import Mathlib.RingTheory.WittVector.MulP #align_import ring_theory.witt_vector.identities from "leanprover-community/mathlib"@"0798037604b2d91748f9b43925fb7570a5f3256c" namespace WittVector variable {p : ℕ} {R : Typ...
Mathlib/RingTheory/WittVector/Identities.lean
95
96
theorem FractionRing.p_nonzero [Nontrivial R] [CharP R p] : (p : FractionRing (𝕎 R)) ≠ 0 := by
simpa using (IsFractionRing.injective (𝕎 R) (FractionRing (𝕎 R))).ne (WittVector.p_nonzero _ _)
2,003
import Mathlib.RingTheory.WittVector.Frobenius import Mathlib.RingTheory.WittVector.Verschiebung import Mathlib.RingTheory.WittVector.MulP #align_import ring_theory.witt_vector.identities from "leanprover-community/mathlib"@"0798037604b2d91748f9b43925fb7570a5f3256c" namespace WittVector variable {p : ℕ} {R : Typ...
Mathlib/RingTheory/WittVector/Identities.lean
103
111
theorem verschiebung_mul_frobenius (x y : 𝕎 R) : verschiebung (x * frobenius y) = verschiebung x * y := by
have : IsPoly₂ p fun {R} [Rcr : CommRing R] x y ↦ verschiebung (x * frobenius y) := IsPoly.comp₂ (hg := verschiebung_isPoly) (hf := IsPoly₂.comp (hh := mulIsPoly₂) (hf := idIsPolyI' p) (hg := frobenius_isPoly p)) have : IsPoly₂ p fun {R} [CommRing R] x y ↦ verschiebung x * y := IsPoly₂.comp (hh := mu...
2,003
import Mathlib.RingTheory.WittVector.Frobenius import Mathlib.RingTheory.WittVector.Verschiebung import Mathlib.RingTheory.WittVector.MulP #align_import ring_theory.witt_vector.identities from "leanprover-community/mathlib"@"0798037604b2d91748f9b43925fb7570a5f3256c" namespace WittVector variable {p : ℕ} {R : Typ...
Mathlib/RingTheory/WittVector/Identities.lean
114
116
theorem mul_charP_coeff_zero [CharP R p] (x : 𝕎 R) : (x * p).coeff 0 = 0 := by
rw [← frobenius_verschiebung, coeff_frobenius_charP, verschiebung_coeff_zero, zero_pow hp.out.ne_zero]
2,003
import Mathlib.RingTheory.WittVector.Frobenius import Mathlib.RingTheory.WittVector.Verschiebung import Mathlib.RingTheory.WittVector.MulP #align_import ring_theory.witt_vector.identities from "leanprover-community/mathlib"@"0798037604b2d91748f9b43925fb7570a5f3256c" namespace WittVector variable {p : ℕ} {R : Typ...
Mathlib/RingTheory/WittVector/Identities.lean
119
121
theorem mul_charP_coeff_succ [CharP R p] (x : 𝕎 R) (i : ℕ) : (x * p).coeff (i + 1) = x.coeff i ^ p := by
rw [← frobenius_verschiebung, coeff_frobenius_charP, verschiebung_coeff_succ]
2,003
import Mathlib.RingTheory.WittVector.Frobenius import Mathlib.RingTheory.WittVector.Verschiebung import Mathlib.RingTheory.WittVector.MulP #align_import ring_theory.witt_vector.identities from "leanprover-community/mathlib"@"0798037604b2d91748f9b43925fb7570a5f3256c" namespace WittVector variable {p : ℕ} {R : Typ...
Mathlib/RingTheory/WittVector/Identities.lean
124
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theorem verschiebung_frobenius [CharP R p] (x : 𝕎 R) : verschiebung (frobenius x) = x * p := by
ext ⟨i⟩ · rw [mul_charP_coeff_zero, verschiebung_coeff_zero] · rw [mul_charP_coeff_succ, verschiebung_coeff_succ, coeff_frobenius_charP]
2,003
import Mathlib.RingTheory.WittVector.Identities #align_import ring_theory.witt_vector.domain from "leanprover-community/mathlib"@"b1d911acd60ab198808e853292106ee352b648ea" noncomputable section open scoped Classical namespace WittVector open Function variable {p : ℕ} {R : Type*} local notation "𝕎" => WittVe...
Mathlib/RingTheory/WittVector/Domain.lean
69
76
theorem verschiebung_shift (x : 𝕎 R) (k : ℕ) (h : ∀ i < k + 1, x.coeff i = 0) : verschiebung (x.shift k.succ) = x.shift k := by
ext ⟨j⟩ · rw [verschiebung_coeff_zero, shift_coeff, h] apply Nat.lt_succ_self · simp only [verschiebung_coeff_succ, shift] congr 1 rw [Nat.add_succ, add_comm, Nat.add_succ, add_comm]
2,004
import Mathlib.RingTheory.WittVector.Identities #align_import ring_theory.witt_vector.domain from "leanprover-community/mathlib"@"b1d911acd60ab198808e853292106ee352b648ea" noncomputable section open scoped Classical namespace WittVector open Function variable {p : ℕ} {R : Type*} local notation "𝕎" => WittVe...
Mathlib/RingTheory/WittVector/Domain.lean
79
85
theorem eq_iterate_verschiebung {x : 𝕎 R} {n : ℕ} (h : ∀ i < n, x.coeff i = 0) : x = verschiebung^[n] (x.shift n) := by
induction' n with k ih · cases x; simp [shift] · dsimp; rw [verschiebung_shift] · exact ih fun i hi => h _ (hi.trans (Nat.lt_succ_self _)) · exact h
2,004
import Mathlib.RingTheory.WittVector.Identities #align_import ring_theory.witt_vector.domain from "leanprover-community/mathlib"@"b1d911acd60ab198808e853292106ee352b648ea" noncomputable section open scoped Classical namespace WittVector open Function variable {p : ℕ} {R : Type*} local notation "𝕎" => WittVe...
Mathlib/RingTheory/WittVector/Domain.lean
88
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theorem verschiebung_nonzero {x : 𝕎 R} (hx : x ≠ 0) : ∃ n : ℕ, ∃ x' : 𝕎 R, x'.coeff 0 ≠ 0 ∧ x = verschiebung^[n] x' := by
have hex : ∃ k : ℕ, x.coeff k ≠ 0 := by by_contra! hall apply hx ext i simp only [hall, zero_coeff] let n := Nat.find hex use n, x.shift n refine ⟨Nat.find_spec hex, eq_iterate_verschiebung fun i hi => not_not.mp ?_⟩ exact Nat.find_min hex hi
2,004
import Mathlib.RingTheory.WittVector.Domain import Mathlib.RingTheory.WittVector.MulCoeff import Mathlib.RingTheory.DiscreteValuationRing.Basic import Mathlib.Tactic.LinearCombination #align_import ring_theory.witt_vector.discrete_valuation_ring from "leanprover-community/mathlib"@"c163ec99dfc664628ca15d215fce0a5b9c2...
Mathlib/RingTheory/WittVector/DiscreteValuationRing.lean
121
135
theorem exists_eq_pow_p_mul (a : 𝕎 k) (ha : a ≠ 0) : ∃ (m : ℕ) (b : 𝕎 k), b.coeff 0 ≠ 0 ∧ a = (p : 𝕎 k) ^ m * b := by
obtain ⟨m, c, hc, hcm⟩ := WittVector.verschiebung_nonzero ha obtain ⟨b, rfl⟩ := (frobenius_bijective p k).surjective.iterate m c rw [WittVector.iterate_frobenius_coeff] at hc have := congr_fun (WittVector.verschiebung_frobenius_comm.comp_iterate m) b simp only [Function.comp_apply] at this rw [← this] at h...
2,005
import Mathlib.RingTheory.WittVector.Truncated import Mathlib.RingTheory.WittVector.Identities import Mathlib.NumberTheory.Padics.RingHoms #align_import ring_theory.witt_vector.compare from "leanprover-community/mathlib"@"168ad7fc5d8173ad38be9767a22d50b8ecf1cd00" noncomputable section variable {p : ℕ} [hp : Fact...
Mathlib/RingTheory/WittVector/Compare.lean
43
53
theorem eq_of_le_of_cast_pow_eq_zero [CharP R p] (i : ℕ) (hin : i ≤ n) (hpi : (p : TruncatedWittVector p n R) ^ i = 0) : i = n := by
contrapose! hpi replace hin := lt_of_le_of_ne hin hpi; clear hpi have : (p : TruncatedWittVector p n R) ^ i = WittVector.truncate n ((p : 𝕎 R) ^ i) := by rw [RingHom.map_pow, map_natCast] rw [this, ne_eq, ext_iff, not_forall]; clear this use ⟨i, hin⟩ rw [WittVector.coeff_truncate, coeff_zero, Fin.val_...
2,006
import Mathlib.RingTheory.WittVector.Truncated import Mathlib.RingTheory.WittVector.Identities import Mathlib.NumberTheory.Padics.RingHoms #align_import ring_theory.witt_vector.compare from "leanprover-community/mathlib"@"168ad7fc5d8173ad38be9767a22d50b8ecf1cd00" noncomputable section variable {p : ℕ} [hp : Fact...
Mathlib/RingTheory/WittVector/Compare.lean
60
61
theorem card_zmod : Fintype.card (TruncatedWittVector p n (ZMod p)) = p ^ n := by
rw [card, ZMod.card]
2,006
import Mathlib.RingTheory.WittVector.Truncated import Mathlib.RingTheory.WittVector.Identities import Mathlib.NumberTheory.Padics.RingHoms #align_import ring_theory.witt_vector.compare from "leanprover-community/mathlib"@"168ad7fc5d8173ad38be9767a22d50b8ecf1cd00" noncomputable section variable {p : ℕ} [hp : Fact...
Mathlib/RingTheory/WittVector/Compare.lean
107
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theorem commutes_symm' {m : ℕ} (hm : n ≤ m) (x : TruncatedWittVector p m (ZMod p)) : (zmodEquivTrunc p n).symm (truncate hm x) = ZMod.castHom (pow_dvd_pow p hm) _ ((zmodEquivTrunc p m).symm x) := by
apply (zmodEquivTrunc p n).injective rw [← commutes' _ _ hm] simp
2,006
import Mathlib.RingTheory.WittVector.Truncated import Mathlib.RingTheory.WittVector.Identities import Mathlib.NumberTheory.Padics.RingHoms #align_import ring_theory.witt_vector.compare from "leanprover-community/mathlib"@"168ad7fc5d8173ad38be9767a22d50b8ecf1cd00" noncomputable section variable {p : ℕ} [hp : Fact...
Mathlib/RingTheory/WittVector/Compare.lean
127
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theorem commutes_symm {m : ℕ} (hm : n ≤ m) : (zmodEquivTrunc p n).symm.toRingHom.comp (truncate hm) = (ZMod.castHom (pow_dvd_pow p hm) _).comp (zmodEquivTrunc p m).symm.toRingHom := by
ext; apply commutes_symm'
2,006
import Mathlib.Algebra.CharP.Pi import Mathlib.Algebra.CharP.Quotient import Mathlib.Algebra.CharP.Subring import Mathlib.Algebra.Ring.Pi import Mathlib.Analysis.SpecialFunctions.Pow.NNReal import Mathlib.FieldTheory.Perfect import Mathlib.RingTheory.Localization.FractionRing import Mathlib.Algebra.Ring.Subring.Basic ...
Mathlib/RingTheory/Perfection.lean
129
130
theorem coeff_pow_p (f : Ring.Perfection R p) (n : ℕ) : coeff R p (n + 1) (f ^ p) = coeff R p n f := by
rw [RingHom.map_pow]; exact f.2 n
2,007
import Mathlib.Algebra.CharP.Pi import Mathlib.Algebra.CharP.Quotient import Mathlib.Algebra.CharP.Subring import Mathlib.Algebra.Ring.Pi import Mathlib.Analysis.SpecialFunctions.Pow.NNReal import Mathlib.FieldTheory.Perfect import Mathlib.RingTheory.Localization.FractionRing import Mathlib.Algebra.Ring.Subring.Basic ...
Mathlib/RingTheory/Perfection.lean
137
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theorem coeff_frobenius (f : Ring.Perfection R p) (n : ℕ) : coeff R p (n + 1) (frobenius _ p f) = coeff R p n f := by
apply coeff_pow_p f n
2,007
import Mathlib.Algebra.CharP.Pi import Mathlib.Algebra.CharP.Quotient import Mathlib.Algebra.CharP.Subring import Mathlib.Algebra.Ring.Pi import Mathlib.Analysis.SpecialFunctions.Pow.NNReal import Mathlib.FieldTheory.Perfect import Mathlib.RingTheory.Localization.FractionRing import Mathlib.Algebra.Ring.Subring.Basic ...
Mathlib/RingTheory/Perfection.lean
406
413
theorem preVal_mk {x : O} (hx : (Ideal.Quotient.mk _ x : ModP K v O hv p) ≠ 0) : preVal K v O hv p (Ideal.Quotient.mk _ x) = v (algebraMap O K x) := by
obtain ⟨r, hr⟩ : ∃ (a : O), a * (p : O) = (Quotient.mk'' x).out' - x := Ideal.mem_span_singleton'.1 <| Ideal.Quotient.eq.1 <| Quotient.sound' <| Quotient.mk_out' _ refine (if_neg hx).trans (v.map_eq_of_sub_lt <| lt_of_not_le ?_) erw [← RingHom.map_sub, ← hr, hv.le_iff_dvd] exact fun hprx => hx (Ideal.Q...
2,007
import Mathlib.Algebra.CharP.Pi import Mathlib.Algebra.CharP.Quotient import Mathlib.Algebra.CharP.Subring import Mathlib.Algebra.Ring.Pi import Mathlib.Analysis.SpecialFunctions.Pow.NNReal import Mathlib.FieldTheory.Perfect import Mathlib.RingTheory.Localization.FractionRing import Mathlib.Algebra.Ring.Subring.Basic ...
Mathlib/RingTheory/Perfection.lean
420
427
theorem preVal_mul {x y : ModP K v O hv p} (hxy0 : x * y ≠ 0) : preVal K v O hv p (x * y) = preVal K v O hv p x * preVal K v O hv p y := by
have hx0 : x ≠ 0 := mt (by rintro rfl; rw [zero_mul]) hxy0 have hy0 : y ≠ 0 := mt (by rintro rfl; rw [mul_zero]) hxy0 obtain ⟨r, rfl⟩ := Ideal.Quotient.mk_surjective x obtain ⟨s, rfl⟩ := Ideal.Quotient.mk_surjective y rw [← map_mul (Ideal.Quotient.mk (Ideal.span {↑p})) r s] at hxy0 ⊢ rw [preVal_mk hx0, pre...
2,007
import Mathlib.Algebra.Algebra.Defs import Mathlib.Algebra.CharP.ExpChar import Mathlib.FieldTheory.Separable #align_import field_theory.separable_degree from "leanprover-community/mathlib"@"d11893b411025250c8e61ff2f12ccbd7ee35ab15" noncomputable section namespace Polynomial open scoped Classical open Polynomial...
Mathlib/RingTheory/Polynomial/SeparableDegree.lean
78
82
theorem IsSeparableContraction.dvd_degree' {g} (hf : IsSeparableContraction q f g) : ∃ m : ℕ, g.natDegree * q ^ m = f.natDegree := by
obtain ⟨m, rfl⟩ := hf.2 use m rw [natDegree_expand]
2,008
import Mathlib.Algebra.Algebra.Defs import Mathlib.Algebra.CharP.ExpChar import Mathlib.FieldTheory.Separable #align_import field_theory.separable_degree from "leanprover-community/mathlib"@"d11893b411025250c8e61ff2f12ccbd7ee35ab15" noncomputable section namespace Polynomial open scoped Classical open Polynomial...
Mathlib/RingTheory/Polynomial/SeparableDegree.lean
96
99
theorem HasSeparableContraction.eq_degree {f : F[X]} (hf : HasSeparableContraction 1 f) : hf.degree = f.natDegree := by
let ⟨a, ha⟩ := hf.dvd_degree' rw [← ha, one_pow a, mul_one]
2,008
import Mathlib.Algebra.Polynomial.Splits #align_import algebra.cubic_discriminant from "leanprover-community/mathlib"@"930133160e24036d5242039fe4972407cd4f1222" noncomputable section @[ext] structure Cubic (R : Type*) where (a b c d : R) #align cubic Cubic namespace Cubic open Cubic Polynomial open Polynom...
Mathlib/Algebra/CubicDiscriminant.lean
67
71
theorem C_mul_prod_X_sub_C_eq [CommRing S] {w x y z : S} : C w * (X - C x) * (X - C y) * (X - C z) = toPoly ⟨w, w * -(x + y + z), w * (x * y + x * z + y * z), w * -(x * y * z)⟩ := by
simp only [toPoly, C_neg, C_add, C_mul] ring1
2,009
import Mathlib.Algebra.Polynomial.Splits #align_import algebra.cubic_discriminant from "leanprover-community/mathlib"@"930133160e24036d5242039fe4972407cd4f1222" noncomputable section @[ext] structure Cubic (R : Type*) where (a b c d : R) #align cubic Cubic namespace Cubic open Cubic Polynomial open Polynom...
Mathlib/Algebra/CubicDiscriminant.lean
75
78
theorem prod_X_sub_C_eq [CommRing S] {x y z : S} : (X - C x) * (X - C y) * (X - C z) = toPoly ⟨1, -(x + y + z), x * y + x * z + y * z, -(x * y * z)⟩ := by
rw [← one_mul <| X - C x, ← C_1, C_mul_prod_X_sub_C_eq, one_mul, one_mul, one_mul]
2,009
import Mathlib.Algebra.Polynomial.Splits #align_import algebra.cubic_discriminant from "leanprover-community/mathlib"@"930133160e24036d5242039fe4972407cd4f1222" noncomputable section @[ext] structure Cubic (R : Type*) where (a b c d : R) #align cubic Cubic namespace Cubic open Cubic Polynomial open Polynom...
Mathlib/Algebra/CubicDiscriminant.lean
121
121
theorem a_of_eq (h : P.toPoly = Q.toPoly) : P.a = Q.a := by
rw [← coeff_eq_a, h, coeff_eq_a]
2,009
import Mathlib.Algebra.Polynomial.Splits #align_import algebra.cubic_discriminant from "leanprover-community/mathlib"@"930133160e24036d5242039fe4972407cd4f1222" noncomputable section @[ext] structure Cubic (R : Type*) where (a b c d : R) #align cubic Cubic namespace Cubic open Cubic Polynomial open Polynom...
Mathlib/Algebra/CubicDiscriminant.lean
124
124
theorem b_of_eq (h : P.toPoly = Q.toPoly) : P.b = Q.b := by
rw [← coeff_eq_b, h, coeff_eq_b]
2,009
import Mathlib.Algebra.Polynomial.Splits #align_import algebra.cubic_discriminant from "leanprover-community/mathlib"@"930133160e24036d5242039fe4972407cd4f1222" noncomputable section @[ext] structure Cubic (R : Type*) where (a b c d : R) #align cubic Cubic namespace Cubic open Cubic Polynomial open Polynom...
Mathlib/Algebra/CubicDiscriminant.lean
127
127
theorem c_of_eq (h : P.toPoly = Q.toPoly) : P.c = Q.c := by
rw [← coeff_eq_c, h, coeff_eq_c]
2,009
import Mathlib.Algebra.Polynomial.Splits #align_import algebra.cubic_discriminant from "leanprover-community/mathlib"@"930133160e24036d5242039fe4972407cd4f1222" noncomputable section @[ext] structure Cubic (R : Type*) where (a b c d : R) #align cubic Cubic namespace Cubic open Cubic Polynomial open Polynom...
Mathlib/Algebra/CubicDiscriminant.lean
130
130
theorem d_of_eq (h : P.toPoly = Q.toPoly) : P.d = Q.d := by
rw [← coeff_eq_d, h, coeff_eq_d]
2,009
import Mathlib.Algebra.Polynomial.Splits #align_import algebra.cubic_discriminant from "leanprover-community/mathlib"@"930133160e24036d5242039fe4972407cd4f1222" noncomputable section @[ext] structure Cubic (R : Type*) where (a b c d : R) #align cubic Cubic namespace Cubic open Cubic Polynomial open Polynom...
Mathlib/Algebra/CubicDiscriminant.lean
137
138
theorem of_a_eq_zero (ha : P.a = 0) : P.toPoly = C P.b * X ^ 2 + C P.c * X + C P.d := by
rw [toPoly, ha, C_0, zero_mul, zero_add]
2,009
import Mathlib.Algebra.Polynomial.Splits #align_import algebra.cubic_discriminant from "leanprover-community/mathlib"@"930133160e24036d5242039fe4972407cd4f1222" noncomputable section @[ext] structure Cubic (R : Type*) where (a b c d : R) #align cubic Cubic namespace Cubic open Cubic Polynomial open Polynom...
Mathlib/Algebra/CubicDiscriminant.lean
145
146
theorem of_b_eq_zero (ha : P.a = 0) (hb : P.b = 0) : P.toPoly = C P.c * X + C P.d := by
rw [of_a_eq_zero ha, hb, C_0, zero_mul, zero_add]
2,009
import Mathlib.Algebra.Polynomial.Splits #align_import algebra.cubic_discriminant from "leanprover-community/mathlib"@"930133160e24036d5242039fe4972407cd4f1222" noncomputable section @[ext] structure Cubic (R : Type*) where (a b c d : R) #align cubic Cubic namespace Cubic open Cubic Polynomial open Polynom...
Mathlib/Algebra/CubicDiscriminant.lean
153
154
theorem of_c_eq_zero (ha : P.a = 0) (hb : P.b = 0) (hc : P.c = 0) : P.toPoly = C P.d := by
rw [of_b_eq_zero ha hb, hc, C_0, zero_mul, zero_add]
2,009
import Mathlib.Algebra.Polynomial.Splits #align_import algebra.cubic_discriminant from "leanprover-community/mathlib"@"930133160e24036d5242039fe4972407cd4f1222" noncomputable section @[ext] structure Cubic (R : Type*) where (a b c d : R) #align cubic Cubic namespace Cubic open Cubic Polynomial open Polynom...
Mathlib/Algebra/CubicDiscriminant.lean
458
459
theorem map_toPoly : (map φ P).toPoly = Polynomial.map φ P.toPoly := by
simp only [map, toPoly, map_C, map_X, Polynomial.map_add, Polynomial.map_mul, Polynomial.map_pow]
2,009
import Mathlib.Algebra.Polynomial.Splits import Mathlib.RingTheory.MvPolynomial.Symmetric #align_import ring_theory.polynomial.vieta from "leanprover-community/mathlib"@"f694c7dead66f5d4c80f446c796a5aad14707f0e" open Polynomial namespace Multiset open Polynomial section Semiring variable {R : Type*} [CommSemi...
Mathlib/RingTheory/Polynomial/Vieta.lean
41
53
theorem prod_X_add_C_eq_sum_esymm (s : Multiset R) : (s.map fun r => X + C r).prod = ∑ j ∈ Finset.range (Multiset.card s + 1), (C (s.esymm j) * X ^ (Multiset.card s - j)) := by
classical rw [prod_map_add, antidiagonal_eq_map_powerset, map_map, ← bind_powerset_len, map_bind, sum_bind, Finset.sum_eq_multiset_sum, Finset.range_val, map_congr (Eq.refl _)] intro _ _ rw [esymm, ← sum_hom', ← sum_map_mul_right, map_congr (Eq.refl _)] intro s ht rw [mem_powersetCard] at h...
2,010
import Mathlib.Algebra.Polynomial.Splits import Mathlib.RingTheory.MvPolynomial.Symmetric #align_import ring_theory.polynomial.vieta from "leanprover-community/mathlib"@"f694c7dead66f5d4c80f446c796a5aad14707f0e" open Polynomial namespace Multiset open Polynomial section Semiring variable {R : Type*} [CommSemi...
Mathlib/RingTheory/Polynomial/Vieta.lean
59
71
theorem prod_X_add_C_coeff (s : Multiset R) {k : ℕ} (h : k ≤ Multiset.card s) : (s.map fun r => X + C r).prod.coeff k = s.esymm (Multiset.card s - k) := by
convert Polynomial.ext_iff.mp (prod_X_add_C_eq_sum_esymm s) k using 1 simp_rw [finset_sum_coeff, coeff_C_mul_X_pow] rw [Finset.sum_eq_single_of_mem (Multiset.card s - k) _] · rw [if_pos (Nat.sub_sub_self h).symm] · intro j hj1 hj2 suffices k ≠ card s - j by rw [if_neg this] intro hn rw [hn, Nat.s...
2,010
import Mathlib.Algebra.Polynomial.Splits import Mathlib.RingTheory.MvPolynomial.Symmetric #align_import ring_theory.polynomial.vieta from "leanprover-community/mathlib"@"f694c7dead66f5d4c80f446c796a5aad14707f0e" open Polynomial namespace Multiset open Polynomial section Semiring variable {R : Type*} [CommSemi...
Mathlib/RingTheory/Polynomial/Vieta.lean
75
77
theorem prod_X_add_C_coeff' {σ} (s : Multiset σ) (r : σ → R) {k : ℕ} (h : k ≤ Multiset.card s) : (s.map fun i => X + C (r i)).prod.coeff k = (s.map r).esymm (Multiset.card s - k) := by
erw [← map_map (fun r => X + C r) r, prod_X_add_C_coeff] <;> rw [s.card_map r]; assumption
2,010
import Mathlib.Algebra.Polynomial.Splits import Mathlib.RingTheory.MvPolynomial.Symmetric #align_import ring_theory.polynomial.vieta from "leanprover-community/mathlib"@"f694c7dead66f5d4c80f446c796a5aad14707f0e" open Polynomial namespace Multiset open Polynomial section Semiring variable {R : Type*} [CommSemi...
Mathlib/RingTheory/Polynomial/Vieta.lean
81
84
theorem _root_.Finset.prod_X_add_C_coeff {σ} (s : Finset σ) (r : σ → R) {k : ℕ} (h : k ≤ s.card) : (∏ i ∈ s, (X + C (r i))).coeff k = ∑ t ∈ s.powersetCard (s.card - k), ∏ i ∈ t, r i := by
rw [Finset.prod, prod_X_add_C_coeff' _ r h, Finset.esymm_map_val] rfl
2,010
import Mathlib.Algebra.Polynomial.Splits import Mathlib.RingTheory.MvPolynomial.Symmetric #align_import ring_theory.polynomial.vieta from "leanprover-community/mathlib"@"f694c7dead66f5d4c80f446c796a5aad14707f0e" open Polynomial namespace Multiset open Polynomial section Ring variable {R : Type*} [CommRing R] ...
Mathlib/RingTheory/Polynomial/Vieta.lean
94
101
theorem esymm_neg (s : Multiset R) (k : ℕ) : (map Neg.neg s).esymm k = (-1) ^ k * esymm s k := by
rw [esymm, esymm, ← Multiset.sum_map_mul_left, Multiset.powersetCard_map, Multiset.map_map, map_congr rfl] intro x hx rw [(mem_powersetCard.mp hx).right.symm, ← prod_replicate, ← Multiset.map_const] nth_rw 3 [← map_id' x] rw [← prod_map_mul, map_congr rfl, Function.comp_apply] exact fun z _ => neg_one_...
2,010
import Mathlib.Algebra.Polynomial.AlgebraMap import Mathlib.Algebra.Polynomial.Inductions import Mathlib.Algebra.Polynomial.Splits import Mathlib.Analysis.Normed.Field.Basic import Mathlib.RingTheory.Polynomial.Vieta #align_import topology.algebra.polynomial from "leanprover-community/mathlib"@"565eb991e264d0db702722...
Mathlib/Topology/Algebra/Polynomial.lean
105
120
theorem tendsto_abv_eval₂_atTop {R S k α : Type*} [Semiring R] [Ring S] [LinearOrderedField k] (f : R →+* S) (abv : S → k) [IsAbsoluteValue abv] (p : R[X]) (hd : 0 < degree p) (hf : f p.leadingCoeff ≠ 0) {l : Filter α} {z : α → S} (hz : Tendsto (abv ∘ z) l atTop) : Tendsto (fun x => abv (p.eval₂ f (z x))) l...
revert hf; refine degree_pos_induction_on p hd ?_ ?_ ?_ <;> clear hd p · rintro _ - hc rw [leadingCoeff_mul_X, leadingCoeff_C] at hc simpa [abv_mul abv] using hz.const_mul_atTop ((abv_pos abv).2 hc) · intro _ _ ihp hf rw [leadingCoeff_mul_X] at hf simpa [abv_mul abv] using (ihp hf).atTop_mul_atTo...
2,011
import Mathlib.Algebra.Polynomial.AlgebraMap import Mathlib.Algebra.Polynomial.Inductions import Mathlib.Algebra.Polynomial.Splits import Mathlib.Analysis.Normed.Field.Basic import Mathlib.RingTheory.Polynomial.Vieta #align_import topology.algebra.polynomial from "leanprover-community/mathlib"@"565eb991e264d0db702722...
Mathlib/Topology/Algebra/Polynomial.lean
123
127
theorem tendsto_abv_atTop {R k α : Type*} [Ring R] [LinearOrderedField k] (abv : R → k) [IsAbsoluteValue abv] (p : R[X]) (h : 0 < degree p) {l : Filter α} {z : α → R} (hz : Tendsto (abv ∘ z) l atTop) : Tendsto (fun x => abv (p.eval (z x))) l atTop := by
apply tendsto_abv_eval₂_atTop _ _ _ h _ hz exact mt leadingCoeff_eq_zero.1 (ne_zero_of_degree_gt h)
2,011
import Mathlib.Topology.Algebra.Polynomial import Mathlib.Topology.ContinuousFunction.Algebra import Mathlib.Topology.UnitInterval import Mathlib.Algebra.Star.Subalgebra #align_import topology.continuous_function.polynomial from "leanprover-community/mathlib"@"a148d797a1094ab554ad4183a4ad6f130358ef64" variable {R...
Mathlib/Topology/ContinuousFunction/Polynomial.lean
76
82
theorem aeval_continuousMap_apply (g : R[X]) (f : C(α, R)) (x : α) : ((Polynomial.aeval f) g) x = g.eval (f x) := by
refine Polynomial.induction_on' g ?_ ?_ · intro p q hp hq simp [hp, hq] · intro n a simp [Pi.pow_apply]
2,012
import Mathlib.Analysis.SpecificLimits.Basic import Mathlib.RingTheory.Polynomial.Bernstein import Mathlib.Topology.ContinuousFunction.Polynomial import Mathlib.Topology.ContinuousFunction.Compact #align_import analysis.special_functions.bernstein from "leanprover-community/mathlib"@"2c1d8ca2812b64f88992a5294ea3dba14...
Mathlib/Analysis/SpecialFunctions/Bernstein.lean
61
64
theorem bernstein_apply (n ν : ℕ) (x : I) : bernstein n ν x = (n.choose ν : ℝ) * (x : ℝ) ^ ν * (1 - (x : ℝ)) ^ (n - ν) := by
dsimp [bernstein, Polynomial.toContinuousMapOn, Polynomial.toContinuousMap, bernsteinPolynomial] simp
2,013
import Mathlib.Analysis.SpecificLimits.Basic import Mathlib.RingTheory.Polynomial.Bernstein import Mathlib.Topology.ContinuousFunction.Polynomial import Mathlib.Topology.ContinuousFunction.Compact #align_import analysis.special_functions.bernstein from "leanprover-community/mathlib"@"2c1d8ca2812b64f88992a5294ea3dba14...
Mathlib/Analysis/SpecialFunctions/Bernstein.lean
67
71
theorem bernstein_nonneg {n ν : ℕ} {x : I} : 0 ≤ bernstein n ν x := by
simp only [bernstein_apply] have h₁ : (0:ℝ) ≤ x := by unit_interval have h₂ : (0:ℝ) ≤ 1 - x := by unit_interval positivity
2,013
import Mathlib.Analysis.SpecificLimits.Basic import Mathlib.RingTheory.Polynomial.Bernstein import Mathlib.Topology.ContinuousFunction.Polynomial import Mathlib.Topology.ContinuousFunction.Compact #align_import analysis.special_functions.bernstein from "leanprover-community/mathlib"@"2c1d8ca2812b64f88992a5294ea3dba14...
Mathlib/Analysis/SpecialFunctions/Bernstein.lean
109
114
theorem probability (n : ℕ) (x : I) : (∑ k : Fin (n + 1), bernstein n k x) = 1 := by
have := bernsteinPolynomial.sum ℝ n apply_fun fun p => Polynomial.aeval (x : ℝ) p at this simp? [AlgHom.map_sum, Finset.sum_range] at this says simp only [Finset.sum_range, map_sum, Polynomial.coe_aeval_eq_eval, map_one] at this exact this
2,013
import Mathlib.Analysis.SpecificLimits.Basic import Mathlib.RingTheory.Polynomial.Bernstein import Mathlib.Topology.ContinuousFunction.Polynomial import Mathlib.Topology.ContinuousFunction.Compact #align_import analysis.special_functions.bernstein from "leanprover-community/mathlib"@"2c1d8ca2812b64f88992a5294ea3dba14...
Mathlib/Analysis/SpecialFunctions/Bernstein.lean
117
136
theorem variance {n : ℕ} (h : 0 < (n : ℝ)) (x : I) : (∑ k : Fin (n + 1), (x - k/ₙ : ℝ) ^ 2 * bernstein n k x) = (x : ℝ) * (1 - x) / n := by
have h' : (n : ℝ) ≠ 0 := ne_of_gt h apply_fun fun x : ℝ => x * n using GroupWithZero.mul_right_injective h' apply_fun fun x : ℝ => x * n using GroupWithZero.mul_right_injective h' dsimp conv_lhs => simp only [Finset.sum_mul, z] conv_rhs => rw [div_mul_cancel₀ _ h'] have := bernsteinPolynomial.variance ℝ ...
2,013
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
Mathlib/Topology/ContinuousFunction/Weierstrass.lean
32
44
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, polynomialFuncti...
2,014
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...
Mathlib/Topology/ContinuousFunction/Weierstrass.lean
54
79
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.to...
2,014
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...
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
2,014
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...
Mathlib/Topology/ContinuousFunction/Weierstrass.lean
99
105
theorem exists_polynomial_near_continuousMap (a b : ℝ) (f : C(Set.Icc a b, ℝ)) (ε : ℝ) (pos : 0 < ε) : ∃ p : ℝ[X], ‖p.toContinuousMapOn _ - f‖ < ε := by
have w := mem_closure_iff_frequently.mp (continuousMap_mem_polynomialFunctions_closure _ _ f) rw [Metric.nhds_basis_ball.frequently_iff] at w obtain ⟨-, H, ⟨m, ⟨-, rfl⟩⟩⟩ := w ε pos rw [Metric.mem_ball, dist_eq_norm] at H exact ⟨m, H⟩
2,014
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...
Mathlib/Topology/ContinuousFunction/Weierstrass.lean
114
122
theorem exists_polynomial_near_of_continuousOn (a b : ℝ) (f : ℝ → ℝ) (c : ContinuousOn f (Set.Icc a b)) (ε : ℝ) (pos : 0 < ε) : ∃ p : ℝ[X], ∀ x ∈ Set.Icc a b, |p.eval x - f x| < ε := by
let f' : C(Set.Icc a b, ℝ) := ⟨fun x => f x, continuousOn_iff_continuous_restrict.mp c⟩ obtain ⟨p, b⟩ := exists_polynomial_near_continuousMap a b f' ε pos use p rw [norm_lt_iff _ pos] at b intro x m exact b ⟨x, m⟩
2,014
import Mathlib.Algebra.Algebra.Subalgebra.Unitization import Mathlib.Analysis.RCLike.Basic import Mathlib.Topology.Algebra.StarSubalgebra import Mathlib.Topology.ContinuousFunction.ContinuousMapZero import Mathlib.Topology.ContinuousFunction.Weierstrass #align_import topology.continuous_function.stone_weierstrass fro...
Mathlib/Topology/ContinuousFunction/StoneWeierstrass.lean
69
77
theorem polynomial_comp_attachBound (A : Subalgebra ℝ C(X, ℝ)) (f : A) (g : ℝ[X]) : (g.toContinuousMapOn (Set.Icc (-‖f‖) ‖f‖)).comp (f : C(X, ℝ)).attachBound = Polynomial.aeval f g := by
ext simp only [ContinuousMap.coe_comp, Function.comp_apply, ContinuousMap.attachBound_apply_coe, Polynomial.toContinuousMapOn_apply, Polynomial.aeval_subalgebra_coe, Polynomial.aeval_continuousMap_apply, Polynomial.toContinuousMap_apply] -- This used to be `rw`, but we need `erw` after leanprover/lean4#2...
2,015
import Mathlib.Algebra.Algebra.Subalgebra.Unitization import Mathlib.Analysis.RCLike.Basic import Mathlib.Topology.Algebra.StarSubalgebra import Mathlib.Topology.ContinuousFunction.ContinuousMapZero import Mathlib.Topology.ContinuousFunction.Weierstrass #align_import topology.continuous_function.stone_weierstrass fro...
Mathlib/Topology/ContinuousFunction/StoneWeierstrass.lean
88
91
theorem polynomial_comp_attachBound_mem (A : Subalgebra ℝ C(X, ℝ)) (f : A) (g : ℝ[X]) : (g.toContinuousMapOn (Set.Icc (-‖f‖) ‖f‖)).comp (f : C(X, ℝ)).attachBound ∈ A := by
rw [polynomial_comp_attachBound] apply SetLike.coe_mem
2,015
import Mathlib.Algebra.Algebra.Subalgebra.Unitization import Mathlib.Analysis.RCLike.Basic import Mathlib.Topology.Algebra.StarSubalgebra import Mathlib.Topology.ContinuousFunction.ContinuousMapZero import Mathlib.Topology.ContinuousFunction.Weierstrass #align_import topology.continuous_function.stone_weierstrass fro...
Mathlib/Topology/ContinuousFunction/StoneWeierstrass.lean
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theorem comp_attachBound_mem_closure (A : Subalgebra ℝ C(X, ℝ)) (f : A) (p : C(Set.Icc (-‖f‖) ‖f‖, ℝ)) : p.comp (attachBound (f : C(X, ℝ))) ∈ A.topologicalClosure := by
-- `p` itself is in the closure of polynomials, by the Weierstrass theorem, have mem_closure : p ∈ (polynomialFunctions (Set.Icc (-‖f‖) ‖f‖)).topologicalClosure := continuousMap_mem_polynomialFunctions_closure _ _ p -- and so there are polynomials arbitrarily close. have frequently_mem_polynomials := mem_c...
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import Mathlib.Algebra.Algebra.Subalgebra.Unitization import Mathlib.Analysis.RCLike.Basic import Mathlib.Topology.Algebra.StarSubalgebra import Mathlib.Topology.ContinuousFunction.ContinuousMapZero import Mathlib.Topology.ContinuousFunction.Weierstrass #align_import topology.continuous_function.stone_weierstrass fro...
Mathlib/Topology/ContinuousFunction/StoneWeierstrass.lean
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theorem abs_mem_subalgebra_closure (A : Subalgebra ℝ C(X, ℝ)) (f : A) : |(f : C(X, ℝ))| ∈ A.topologicalClosure := by
let f' := attachBound (f : C(X, ℝ)) let abs : C(Set.Icc (-‖f‖) ‖f‖, ℝ) := { toFun := fun x : Set.Icc (-‖f‖) ‖f‖ => |(x : ℝ)| } change abs.comp f' ∈ A.topologicalClosure apply comp_attachBound_mem_closure
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import Mathlib.Algebra.Algebra.Subalgebra.Unitization import Mathlib.Analysis.RCLike.Basic import Mathlib.Topology.Algebra.StarSubalgebra import Mathlib.Topology.ContinuousFunction.ContinuousMapZero import Mathlib.Topology.ContinuousFunction.Weierstrass #align_import topology.continuous_function.stone_weierstrass fro...
Mathlib/Topology/ContinuousFunction/StoneWeierstrass.lean
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theorem inf_mem_subalgebra_closure (A : Subalgebra ℝ C(X, ℝ)) (f g : A) : (f : C(X, ℝ)) ⊓ (g : C(X, ℝ)) ∈ A.topologicalClosure := by
rw [inf_eq_half_smul_add_sub_abs_sub' ℝ] refine A.topologicalClosure.smul_mem (A.topologicalClosure.sub_mem (A.topologicalClosure.add_mem (A.le_topologicalClosure f.property) (A.le_topologicalClosure g.property)) ?_) _ exact mod_cast abs_mem_subalgebra_closure A _
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import Mathlib.Algebra.Algebra.Subalgebra.Unitization import Mathlib.Analysis.RCLike.Basic import Mathlib.Topology.Algebra.StarSubalgebra import Mathlib.Topology.ContinuousFunction.ContinuousMapZero import Mathlib.Topology.ContinuousFunction.Weierstrass #align_import topology.continuous_function.stone_weierstrass fro...
Mathlib/Topology/ContinuousFunction/StoneWeierstrass.lean
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theorem inf_mem_closed_subalgebra (A : Subalgebra ℝ C(X, ℝ)) (h : IsClosed (A : Set C(X, ℝ))) (f g : A) : (f : C(X, ℝ)) ⊓ (g : C(X, ℝ)) ∈ A := by
convert inf_mem_subalgebra_closure A f g apply SetLike.ext' symm erw [closure_eq_iff_isClosed] exact h
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import Mathlib.Algebra.Algebra.Subalgebra.Unitization import Mathlib.Analysis.RCLike.Basic import Mathlib.Topology.Algebra.StarSubalgebra import Mathlib.Topology.ContinuousFunction.ContinuousMapZero import Mathlib.Topology.ContinuousFunction.Weierstrass #align_import topology.continuous_function.stone_weierstrass fro...
Mathlib/Topology/ContinuousFunction/StoneWeierstrass.lean
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theorem sup_mem_subalgebra_closure (A : Subalgebra ℝ C(X, ℝ)) (f g : A) : (f : C(X, ℝ)) ⊔ (g : C(X, ℝ)) ∈ A.topologicalClosure := by
rw [sup_eq_half_smul_add_add_abs_sub' ℝ] refine A.topologicalClosure.smul_mem (A.topologicalClosure.add_mem (A.topologicalClosure.add_mem (A.le_topologicalClosure f.property) (A.le_topologicalClosure g.property)) ?_) _ exact mod_cast abs_mem_subalgebra_closure A _
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import Mathlib.Algebra.Algebra.Subalgebra.Unitization import Mathlib.Analysis.RCLike.Basic import Mathlib.Topology.Algebra.StarSubalgebra import Mathlib.Topology.ContinuousFunction.ContinuousMapZero import Mathlib.Topology.ContinuousFunction.Weierstrass #align_import topology.continuous_function.stone_weierstrass fro...
Mathlib/Topology/ContinuousFunction/StoneWeierstrass.lean
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theorem sup_mem_closed_subalgebra (A : Subalgebra ℝ C(X, ℝ)) (h : IsClosed (A : Set C(X, ℝ))) (f g : A) : (f : C(X, ℝ)) ⊔ (g : C(X, ℝ)) ∈ A := by
convert sup_mem_subalgebra_closure A f g apply SetLike.ext' symm erw [closure_eq_iff_isClosed] exact h
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import Mathlib.Algebra.Algebra.Subalgebra.Unitization import Mathlib.Analysis.RCLike.Basic import Mathlib.Topology.Algebra.StarSubalgebra import Mathlib.Topology.ContinuousFunction.ContinuousMapZero import Mathlib.Topology.ContinuousFunction.Weierstrass #align_import topology.continuous_function.stone_weierstrass fro...
Mathlib/Topology/ContinuousFunction/StoneWeierstrass.lean
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theorem Subalgebra.SeparatesPoints.rclike_to_real {A : StarSubalgebra 𝕜 C(X, 𝕜)} (hA : A.SeparatesPoints) : ((A.restrictScalars ℝ).comap (ofRealAm.compLeftContinuous ℝ continuous_ofReal)).SeparatesPoints := by
intro x₁ x₂ hx -- Let `f` in the subalgebra `A` separate the points `x₁`, `x₂` obtain ⟨_, ⟨f, hfA, rfl⟩, hf⟩ := hA hx let F : C(X, 𝕜) := f - const _ (f x₂) -- Subtract the constant `f x₂` from `f`; this is still an element of the subalgebra have hFA : F ∈ A := by refine A.sub_mem hfA (@Eq.subst _ (· ∈...
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import Mathlib.Algebra.Polynomial.Identities import Mathlib.Analysis.SpecificLimits.Basic import Mathlib.NumberTheory.Padics.PadicIntegers import Mathlib.Topology.Algebra.Polynomial import Mathlib.Topology.MetricSpace.CauSeqFilter #align_import number_theory.padics.hensel from "leanprover-community/mathlib"@"f2ce6086...
Mathlib/NumberTheory/Padics/Hensel.lean
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theorem padic_polynomial_dist {p : ℕ} [Fact p.Prime] (F : Polynomial ℤ_[p]) (x y : ℤ_[p]) : ‖F.eval x - F.eval y‖ ≤ ‖x - y‖ := let ⟨z, hz⟩ := F.evalSubFactor x y calc ‖F.eval x - F.eval y‖ = ‖z‖ * ‖x - y‖ := by
simp [hz] _ ≤ 1 * ‖x - y‖ := by gcongr; apply PadicInt.norm_le_one _ = ‖x - y‖ := by simp
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import Mathlib.Algebra.Algebra.Quasispectrum import Mathlib.Algebra.Algebra.Spectrum import Mathlib.Algebra.Star.Order import Mathlib.Topology.Algebra.Polynomial import Mathlib.Topology.ContinuousFunction.Algebra section Basic class ContinuousFunctionalCalculus (R : Type*) {A : Type*} (p : outParam (A → Prop)) ...
Mathlib/Topology/ContinuousFunction/FunctionalCalculus.lean
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theorem cfcHom_comp [UniqueContinuousFunctionalCalculus R A] (f : C(spectrum R a, R)) (f' : C(spectrum R a, spectrum R (cfcHom ha f))) (hff' : ∀ x, f x = f' x) (g : C(spectrum R (cfcHom ha f), R)) : cfcHom ha (g.comp f') = cfcHom (cfcHom_predicate ha f) g := by
let φ : C(spectrum R (cfcHom ha f), R) →⋆ₐ[R] A := (cfcHom ha).comp <| ContinuousMap.compStarAlgHom' R R f' suffices cfcHom (cfcHom_predicate ha f) = φ from DFunLike.congr_fun this.symm g refine cfcHom_eq_of_continuous_of_map_id (cfcHom_predicate ha f) φ ?_ ?_ · exact (cfcHom_closedEmbedding ha).continuous...
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import Mathlib.Algebra.Algebra.Quasispectrum import Mathlib.Topology.ContinuousFunction.Compact import Mathlib.Topology.ContinuousFunction.ContinuousMapZero import Mathlib.Topology.ContinuousFunction.FunctionalCalculus import Mathlib.Topology.UniformSpace.CompactConvergence local notation "σₙ" => quasispectrum open...
Mathlib/Topology/ContinuousFunction/NonUnitalFunctionalCalculus.lean
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theorem cfcₙHom_comp [UniqueNonUnitalContinuousFunctionalCalculus R A] (f : C(σₙ R a, R)₀) (f' : C(σₙ R a, σₙ R (cfcₙHom ha f))₀) (hff' : ∀ x, f x = f' x) (g : C(σₙ R (cfcₙHom ha f), R)₀) : cfcₙHom ha (g.comp f') = cfcₙHom (cfcₙHom_predicate ha f) g := by
let ψ : C(σₙ R (cfcₙHom ha f), R)₀ →⋆ₙₐ[R] C(σₙ R a, R)₀ := { toFun := (ContinuousMapZero.comp · f') map_smul' := fun _ _ ↦ rfl map_add' := fun _ _ ↦ rfl map_mul' := fun _ _ ↦ rfl map_zero' := rfl map_star' := fun _ ↦ rfl } let φ : C(σₙ R (cfcₙHom ha f), R)₀ →⋆ₙₐ[R] A := (cfcₙHom ...
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import Mathlib.Analysis.Calculus.LocalExtr.Rolle import Mathlib.Analysis.Calculus.Deriv.Polynomial import Mathlib.Topology.Algebra.Polynomial #align_import analysis.calculus.local_extr from "leanprover-community/mathlib"@"3bce8d800a6f2b8f63fe1e588fd76a9ff4adcebe" namespace Polynomial
Mathlib/Analysis/Calculus/LocalExtr/Polynomial.lean
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theorem card_roots_toFinset_le_card_roots_derivative_diff_roots_succ (p : ℝ[X]) : p.roots.toFinset.card ≤ (p.derivative.roots.toFinset \ p.roots.toFinset).card + 1 := by
rcases eq_or_ne (derivative p) 0 with hp' | hp' · rw [eq_C_of_derivative_eq_zero hp', roots_C, Multiset.toFinset_zero, Finset.card_empty] exact zero_le _ have hp : p ≠ 0 := ne_of_apply_ne derivative (by rwa [derivative_zero]) refine Finset.card_le_diff_of_interleaved fun x hx y hy hxy hxy' => ?_ rw [Mult...
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import Mathlib.Analysis.Calculus.LocalExtr.Rolle import Mathlib.Analysis.Calculus.Deriv.Polynomial import Mathlib.Topology.Algebra.Polynomial #align_import analysis.calculus.local_extr from "leanprover-community/mathlib"@"3bce8d800a6f2b8f63fe1e588fd76a9ff4adcebe" namespace Polynomial theorem card_roots_toFinset_...
Mathlib/Analysis/Calculus/LocalExtr/Polynomial.lean
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theorem card_roots_le_derivative (p : ℝ[X]) : Multiset.card p.roots ≤ Multiset.card (derivative p).roots + 1 := calc Multiset.card p.roots = ∑ x ∈ p.roots.toFinset, p.roots.count x := (Multiset.toFinset_sum_count_eq _).symm _ = ∑ x ∈ p.roots.toFinset, (p.roots.count x - 1 + 1) := (Eq.symm <| F...
simp only [Finset.sum_add_distrib, Finset.card_eq_sum_ones, count_roots] _ ≤ (∑ x ∈ p.roots.toFinset, p.derivative.rootMultiplicity x) + ((p.derivative.roots.toFinset \ p.roots.toFinset).card + 1) := (add_le_add (Finset.sum_le_sum fun x _ => rootMultiplicity_sub_one_le_derivative_root...
2,019
import Mathlib.Analysis.Calculus.LocalExtr.Rolle import Mathlib.Analysis.Calculus.Deriv.Polynomial import Mathlib.Topology.Algebra.Polynomial #align_import analysis.calculus.local_extr from "leanprover-community/mathlib"@"3bce8d800a6f2b8f63fe1e588fd76a9ff4adcebe" namespace Polynomial theorem card_roots_toFinset_...
Mathlib/Analysis/Calculus/LocalExtr/Polynomial.lean
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theorem card_rootSet_le_derivative {F : Type*} [CommRing F] [Algebra F ℝ] (p : F[X]) : Fintype.card (p.rootSet ℝ) ≤ Fintype.card (p.derivative.rootSet ℝ) + 1 := by
simpa only [rootSet_def, Finset.coe_sort_coe, Fintype.card_coe, derivative_map] using card_roots_toFinset_le_derivative (p.map (algebraMap F ℝ))
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import Mathlib.Algebra.GroupWithZero.NonZeroDivisors import Mathlib.Algebra.Polynomial.Lifts import Mathlib.GroupTheory.MonoidLocalization import Mathlib.RingTheory.Algebraic import Mathlib.RingTheory.Ideal.LocalRing import Mathlib.RingTheory.IntegralClosure import Mathlib.RingTheory.Localization.FractionRing import M...
Mathlib/RingTheory/Localization/Integral.lean
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theorem coeffIntegerNormalization_of_not_mem_support (p : S[X]) (i : ℕ) (h : coeff p i = 0) : coeffIntegerNormalization M p i = 0 := by
simp only [coeffIntegerNormalization, h, mem_support_iff, eq_self_iff_true, not_true, Ne, dif_neg, not_false_iff]
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import Mathlib.Algebra.GroupWithZero.NonZeroDivisors import Mathlib.Algebra.Polynomial.Lifts import Mathlib.GroupTheory.MonoidLocalization import Mathlib.RingTheory.Algebraic import Mathlib.RingTheory.Ideal.LocalRing import Mathlib.RingTheory.IntegralClosure import Mathlib.RingTheory.Localization.FractionRing import M...
Mathlib/RingTheory/Localization/Integral.lean
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theorem coeffIntegerNormalization_mem_support (p : S[X]) (i : ℕ) (h : coeffIntegerNormalization M p i ≠ 0) : i ∈ p.support := by
contrapose h rw [Ne, Classical.not_not, coeffIntegerNormalization, dif_neg h]
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import Mathlib.Algebra.GroupWithZero.NonZeroDivisors import Mathlib.Algebra.Polynomial.Lifts import Mathlib.GroupTheory.MonoidLocalization import Mathlib.RingTheory.Algebraic import Mathlib.RingTheory.Ideal.LocalRing import Mathlib.RingTheory.IntegralClosure import Mathlib.RingTheory.Localization.FractionRing import M...
Mathlib/RingTheory/Localization/Integral.lean
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theorem integerNormalization_coeff (p : S[X]) (i : ℕ) : (integerNormalization M p).coeff i = coeffIntegerNormalization M p i := by
simp (config := { contextual := true }) [integerNormalization, coeff_monomial, coeffIntegerNormalization_of_not_mem_support]
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import Mathlib.Algebra.GroupWithZero.NonZeroDivisors import Mathlib.Algebra.Polynomial.Lifts import Mathlib.GroupTheory.MonoidLocalization import Mathlib.RingTheory.Algebraic import Mathlib.RingTheory.Ideal.LocalRing import Mathlib.RingTheory.IntegralClosure import Mathlib.RingTheory.Localization.FractionRing import M...
Mathlib/RingTheory/Localization/Integral.lean
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theorem integerNormalization_spec (p : S[X]) : ∃ b : M, ∀ i, algebraMap R S ((integerNormalization M p).coeff i) = (b : R) • p.coeff i := by
use Classical.choose (exist_integer_multiples_of_finset M (p.support.image p.coeff)) intro i rw [integerNormalization_coeff, coeffIntegerNormalization] split_ifs with hi · exact Classical.choose_spec (Classical.choose_spec (exist_integer_multiples_of_finset M (p.support.image p.coeff)) ...
2,020
import Mathlib.Algebra.GroupWithZero.NonZeroDivisors import Mathlib.Algebra.Polynomial.Lifts import Mathlib.GroupTheory.MonoidLocalization import Mathlib.RingTheory.Algebraic import Mathlib.RingTheory.Ideal.LocalRing import Mathlib.RingTheory.IntegralClosure import Mathlib.RingTheory.Localization.FractionRing import M...
Mathlib/RingTheory/Localization/Integral.lean
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theorem integerNormalization_aeval_eq_zero [Algebra R R'] [Algebra S R'] [IsScalarTower R S R'] (p : S[X]) {x : R'} (hx : aeval x p = 0) : aeval x (integerNormalization M p) = 0 := by
rw [aeval_def, IsScalarTower.algebraMap_eq R S R', integerNormalization_eval₂_eq_zero _ (algebraMap _ _) _ hx]
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import Mathlib.Algebra.GroupWithZero.NonZeroDivisors import Mathlib.Algebra.Polynomial.Lifts import Mathlib.GroupTheory.MonoidLocalization import Mathlib.RingTheory.Algebraic import Mathlib.RingTheory.Ideal.LocalRing import Mathlib.RingTheory.IntegralClosure import Mathlib.RingTheory.Localization.FractionRing import M...
Mathlib/RingTheory/Localization/Integral.lean
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theorem RingHom.isIntegralElem_localization_at_leadingCoeff {R S : Type*} [CommRing R] [CommRing S] (f : R →+* S) (x : S) (p : R[X]) (hf : p.eval₂ f x = 0) (M : Submonoid R) (hM : p.leadingCoeff ∈ M) {Rₘ Sₘ : Type*} [CommRing Rₘ] [CommRing Sₘ] [Algebra R Rₘ] [IsLocalization M Rₘ] [Algebra S Sₘ] [IsLocalizat...
by_cases triv : (1 : Rₘ) = 0 · exact ⟨0, ⟨_root_.trans leadingCoeff_zero triv.symm, eval₂_zero _ _⟩⟩ haveI : Nontrivial Rₘ := nontrivial_of_ne 1 0 triv obtain ⟨b, hb⟩ := isUnit_iff_exists_inv.mp (map_units Rₘ ⟨p.leadingCoeff, hM⟩) refine ⟨p.map (algebraMap R Rₘ) * C b, ⟨?_, ?_⟩⟩ · refine monic_mul_C_of_lea...
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import Mathlib.RingTheory.IntegralClosure import Mathlib.RingTheory.Localization.Integral #align_import ring_theory.integrally_closed from "leanprover-community/mathlib"@"d35b4ff446f1421bd551fafa4b8efd98ac3ac408" open scoped nonZeroDivisors Polynomial open Polynomial abbrev IsIntegrallyClosedIn (R A : Type*) [...
Mathlib/RingTheory/IntegrallyClosed.lean
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theorem AlgHom.isIntegrallyClosedIn (f : A →ₐ[R] B) (hf : Function.Injective f) : IsIntegrallyClosedIn R B → IsIntegrallyClosedIn R A := by
rintro ⟨inj, cl⟩ refine ⟨Function.Injective.of_comp (f := f) ?_, fun hx => ?_, ?_⟩ · convert inj aesop · obtain ⟨y, fx_eq⟩ := cl.mp ((isIntegral_algHom_iff f hf).mpr hx) aesop · rintro ⟨y, rfl⟩ apply (isIntegral_algHom_iff f hf).mp aesop
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import Mathlib.RingTheory.IntegralClosure import Mathlib.RingTheory.Localization.Integral #align_import ring_theory.integrally_closed from "leanprover-community/mathlib"@"d35b4ff446f1421bd551fafa4b8efd98ac3ac408" open scoped nonZeroDivisors Polynomial open Polynomial abbrev IsIntegrallyClosedIn (R A : Type*) [...
Mathlib/RingTheory/IntegrallyClosed.lean
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theorem isIntegrallyClosedIn_iff {R A : Type*} [CommRing R] [CommRing A] [Algebra R A] : IsIntegrallyClosedIn R A ↔ Function.Injective (algebraMap R A) ∧ ∀ {x : A}, IsIntegral R x → ∃ y, algebraMap R A y = x := by
constructor · rintro ⟨_, cl⟩ aesop · rintro ⟨inj, cl⟩ refine ⟨inj, by aesop, ?_⟩ rintro ⟨y, rfl⟩ apply isIntegral_algebraMap
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import Mathlib.RingTheory.IntegralClosure import Mathlib.RingTheory.Localization.Integral #align_import ring_theory.integrally_closed from "leanprover-community/mathlib"@"d35b4ff446f1421bd551fafa4b8efd98ac3ac408" open scoped nonZeroDivisors Polynomial open Polynomial abbrev IsIntegrallyClosedIn (R A : Type*) [...
Mathlib/RingTheory/IntegrallyClosed.lean
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theorem isIntegrallyClosed_iff : IsIntegrallyClosed R ↔ ∀ {x : K}, IsIntegral R x → ∃ y, algebraMap R K y = x := by
simp [isIntegrallyClosed_iff_isIntegrallyClosedIn K, isIntegrallyClosedIn_iff, IsFractionRing.injective R K]
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import Mathlib.RingTheory.IntegralClosure import Mathlib.RingTheory.Localization.Integral #align_import ring_theory.integrally_closed from "leanprover-community/mathlib"@"d35b4ff446f1421bd551fafa4b8efd98ac3ac408" open scoped nonZeroDivisors Polynomial open Polynomial abbrev IsIntegrallyClosedIn (R A : Type*) [...
Mathlib/RingTheory/IntegrallyClosed.lean
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theorem integralClosure_eq_bot_iff (hRA : Function.Injective (algebraMap R A)) : integralClosure R A = ⊥ ↔ IsIntegrallyClosedIn R A := by
refine eq_bot_iff.trans ?_ constructor · intro h refine ⟨ hRA, fun hx => Set.mem_range.mp (Algebra.mem_bot.mp (h hx)), ?_⟩ rintro ⟨y, rfl⟩ apply isIntegral_algebraMap · intro h x hx rw [Algebra.mem_bot, Set.mem_range] exact isIntegral_iff.mp hx
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import Mathlib.Algebra.GCDMonoid.Basic import Mathlib.RingTheory.IntegrallyClosed import Mathlib.RingTheory.Polynomial.Eisenstein.Basic #align_import algebra.gcd_monoid.integrally_closed from "leanprover-community/mathlib"@"2032a878972d5672e7c27c957e7a6e297b044973" open scoped Polynomial variable {R A : Type*} [...
Mathlib/Algebra/GCDMonoid/IntegrallyClosed.lean
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theorem IsLocalization.surj_of_gcd_domain [GCDMonoid R] (M : Submonoid R) [IsLocalization M A] (z : A) : ∃ a b : R, IsUnit (gcd a b) ∧ z * algebraMap R A b = algebraMap R A a := by
obtain ⟨x, ⟨y, hy⟩, rfl⟩ := IsLocalization.mk'_surjective M z obtain ⟨x', y', hx', hy', hu⟩ := extract_gcd x y use x', y', hu rw [mul_comm, IsLocalization.mul_mk'_eq_mk'_of_mul] convert IsLocalization.mk'_mul_cancel_left (M := M) (S := A) _ _ using 2 rw [Subtype.coe_mk, hy', ← mul_comm y', mul_assoc]; conv...
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import Mathlib.FieldTheory.SplittingField.Construction import Mathlib.RingTheory.Int.Basic import Mathlib.RingTheory.Localization.Integral import Mathlib.RingTheory.IntegrallyClosed #align_import ring_theory.polynomial.gauss_lemma from "leanprover-community/mathlib"@"e3f4be1fcb5376c4948d7f095bec45350bfb9d1a" open...
Mathlib/RingTheory/Polynomial/GaussLemma.lean
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theorem integralClosure.mem_lifts_of_monic_of_dvd_map {f : R[X]} (hf : f.Monic) {g : K[X]} (hg : g.Monic) (hd : g ∣ f.map (algebraMap R K)) : g ∈ lifts (algebraMap (integralClosure R K) K) := by
have := mem_lift_of_splits_of_roots_mem_range (integralClosure R g.SplittingField) ((splits_id_iff_splits _).2 <| SplittingField.splits g) (hg.map _) fun a ha => (SetLike.ext_iff.mp (integralClosure R g.SplittingField).range_algebraMap _).mpr <| roots_mem_integralClosure hf ?_ · rw [lifts_iff_coe...
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import Mathlib.FieldTheory.SplittingField.Construction import Mathlib.RingTheory.Int.Basic import Mathlib.RingTheory.Localization.Integral import Mathlib.RingTheory.IntegrallyClosed #align_import ring_theory.polynomial.gauss_lemma from "leanprover-community/mathlib"@"e3f4be1fcb5376c4948d7f095bec45350bfb9d1a" open...
Mathlib/RingTheory/Polynomial/GaussLemma.lean
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theorem IsIntegrallyClosed.eq_map_mul_C_of_dvd [IsIntegrallyClosed R] {f : R[X]} (hf : f.Monic) {g : K[X]} (hg : g ∣ f.map (algebraMap R K)) : ∃ g' : R[X], g'.map (algebraMap R K) * (C <| leadingCoeff g) = g := by
have g_ne_0 : g ≠ 0 := ne_zero_of_dvd_ne_zero (Monic.ne_zero <| hf.map (algebraMap R K)) hg suffices lem : ∃ g' : R[X], g'.map (algebraMap R K) = g * C g.leadingCoeff⁻¹ by obtain ⟨g', hg'⟩ := lem use g' rw [hg', mul_assoc, ← C_mul, inv_mul_cancel (leadingCoeff_ne_zero.mpr g_ne_0), C_1, mul_one] have ...
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import Mathlib.FieldTheory.SplittingField.Construction import Mathlib.RingTheory.Int.Basic import Mathlib.RingTheory.Localization.Integral import Mathlib.RingTheory.IntegrallyClosed #align_import ring_theory.polynomial.gauss_lemma from "leanprover-community/mathlib"@"e3f4be1fcb5376c4948d7f095bec45350bfb9d1a" open...
Mathlib/RingTheory/Polynomial/GaussLemma.lean
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theorem IsPrimitive.isUnit_iff_isUnit_map_of_injective : IsUnit f ↔ IsUnit (map φ f) := by
refine ⟨(mapRingHom φ).isUnit_map, fun h => ?_⟩ rcases isUnit_iff.1 h with ⟨_, ⟨u, rfl⟩, hu⟩ have hdeg := degree_C u.ne_zero rw [hu, degree_map_eq_of_injective hinj] at hdeg rw [eq_C_of_degree_eq_zero hdeg] at hf ⊢ exact isUnit_C.mpr (isPrimitive_iff_isUnit_of_C_dvd.mp hf (f.coeff 0) dvd_rfl)
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import Mathlib.FieldTheory.SplittingField.Construction import Mathlib.RingTheory.Int.Basic import Mathlib.RingTheory.Localization.Integral import Mathlib.RingTheory.IntegrallyClosed #align_import ring_theory.polynomial.gauss_lemma from "leanprover-community/mathlib"@"e3f4be1fcb5376c4948d7f095bec45350bfb9d1a" open...
Mathlib/RingTheory/Polynomial/GaussLemma.lean
124
130
theorem IsPrimitive.irreducible_of_irreducible_map_of_injective (h_irr : Irreducible (map φ f)) : Irreducible f := by
refine ⟨fun h => h_irr.not_unit (IsUnit.map (mapRingHom φ) h), fun a b h => (h_irr.isUnit_or_isUnit <| by rw [h, Polynomial.map_mul]).imp ?_ ?_⟩ all_goals apply ((isPrimitive_of_dvd hf _).isUnit_iff_isUnit_map_of_injective hinj).mpr exacts [Dvd.intro _ h.symm, Dvd.intro_left _ h.symm]
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import Mathlib.RingTheory.AdjoinRoot import Mathlib.FieldTheory.Minpoly.Field import Mathlib.RingTheory.Polynomial.GaussLemma #align_import field_theory.minpoly.is_integrally_closed from "leanprover-community/mathlib"@"f0c8bf9245297a541f468be517f1bde6195105e9" open scoped Classical Polynomial open Polynomial Set...
Mathlib/FieldTheory/Minpoly/IsIntegrallyClosed.lean
50
55
theorem isIntegrallyClosed_eq_field_fractions [IsDomain S] {s : S} (hs : IsIntegral R s) : minpoly K (algebraMap S L s) = (minpoly R s).map (algebraMap R K) := by
refine (eq_of_irreducible_of_monic ?_ ?_ ?_).symm · exact ((monic hs).irreducible_iff_irreducible_map_fraction_map).1 (irreducible hs) · rw [aeval_map_algebraMap, aeval_algebraMap_apply, aeval, map_zero] · exact (monic hs).map _
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import Mathlib.RingTheory.AdjoinRoot import Mathlib.FieldTheory.Minpoly.Field import Mathlib.RingTheory.Polynomial.GaussLemma #align_import field_theory.minpoly.is_integrally_closed from "leanprover-community/mathlib"@"f0c8bf9245297a541f468be517f1bde6195105e9" open scoped Classical Polynomial open Polynomial Set...
Mathlib/FieldTheory/Minpoly/IsIntegrallyClosed.lean
61
64
theorem isIntegrallyClosed_eq_field_fractions' [IsDomain S] [Algebra K S] [IsScalarTower R K S] {s : S} (hs : IsIntegral R s) : minpoly K s = (minpoly R s).map (algebraMap R K) := by
let L := FractionRing S rw [← isIntegrallyClosed_eq_field_fractions K L hs, algebraMap_eq (IsFractionRing.injective S L)]
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import Mathlib.RingTheory.AdjoinRoot import Mathlib.FieldTheory.Minpoly.Field import Mathlib.RingTheory.Polynomial.GaussLemma #align_import field_theory.minpoly.is_integrally_closed from "leanprover-community/mathlib"@"f0c8bf9245297a541f468be517f1bde6195105e9" open scoped Classical Polynomial open Polynomial Set...
Mathlib/FieldTheory/Minpoly/IsIntegrallyClosed.lean
75
92
theorem isIntegrallyClosed_dvd {s : S} (hs : IsIntegral R s) {p : R[X]} (hp : Polynomial.aeval s p = 0) : minpoly R s ∣ p := by
let K := FractionRing R let L := FractionRing S let _ : Algebra K L := FractionRing.liftAlgebra R L have := FractionRing.isScalarTower_liftAlgebra R L have : minpoly K (algebraMap S L s) ∣ map (algebraMap R K) (p %ₘ minpoly R s) := by rw [map_modByMonic _ (minpoly.monic hs), modByMonic_eq_sub_mul_div] ...
2,024
import Mathlib.RingTheory.AdjoinRoot import Mathlib.FieldTheory.Minpoly.Field import Mathlib.RingTheory.Polynomial.GaussLemma #align_import field_theory.minpoly.is_integrally_closed from "leanprover-community/mathlib"@"f0c8bf9245297a541f468be517f1bde6195105e9" open scoped Classical Polynomial open Polynomial Set...
Mathlib/FieldTheory/Minpoly/IsIntegrallyClosed.lean
103
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theorem ker_eval {s : S} (hs : IsIntegral R s) : RingHom.ker ((Polynomial.aeval s).toRingHom : R[X] →+* S) = Ideal.span ({minpoly R s} : Set R[X]) := by
ext p simp_rw [RingHom.mem_ker, AlgHom.toRingHom_eq_coe, AlgHom.coe_toRingHom, isIntegrallyClosed_dvd_iff hs, ← Ideal.mem_span_singleton]
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import Mathlib.RingTheory.AdjoinRoot import Mathlib.FieldTheory.Minpoly.Field import Mathlib.RingTheory.Polynomial.GaussLemma #align_import field_theory.minpoly.is_integrally_closed from "leanprover-community/mathlib"@"f0c8bf9245297a541f468be517f1bde6195105e9" open scoped Classical Polynomial open Polynomial Set...
Mathlib/FieldTheory/Minpoly/IsIntegrallyClosed.lean
114
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theorem IsIntegrallyClosed.degree_le_of_ne_zero {s : S} (hs : IsIntegral R s) {p : R[X]} (hp0 : p ≠ 0) (hp : Polynomial.aeval s p = 0) : degree (minpoly R s) ≤ degree p := by
rw [degree_eq_natDegree (minpoly.ne_zero hs), degree_eq_natDegree hp0] norm_cast exact natDegree_le_of_dvd ((isIntegrallyClosed_dvd_iff hs _).mp hp) hp0
2,024
import Mathlib.RingTheory.AdjoinRoot import Mathlib.FieldTheory.Minpoly.Field import Mathlib.RingTheory.Polynomial.GaussLemma #align_import field_theory.minpoly.is_integrally_closed from "leanprover-community/mathlib"@"f0c8bf9245297a541f468be517f1bde6195105e9" open scoped Classical Polynomial open Polynomial Set...
Mathlib/FieldTheory/Minpoly/IsIntegrallyClosed.lean
125
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theorem _root_.IsIntegrallyClosed.minpoly.unique {s : S} {P : R[X]} (hmo : P.Monic) (hP : Polynomial.aeval s P = 0) (Pmin : ∀ Q : R[X], Q.Monic → Polynomial.aeval s Q = 0 → degree P ≤ degree Q) : P = minpoly R s := by
have hs : IsIntegral R s := ⟨P, hmo, hP⟩ symm; apply eq_of_sub_eq_zero by_contra hnz refine IsIntegrallyClosed.degree_le_of_ne_zero hs hnz (by simp [hP]) |>.not_lt ?_ refine degree_sub_lt ?_ (ne_zero hs) ?_ · exact le_antisymm (min R s hmo hP) (Pmin (minpoly R s) (monic hs) (aeval R s)) · rw [(monic hs)....
2,024
import Mathlib.RingTheory.AdjoinRoot import Mathlib.FieldTheory.Minpoly.Field import Mathlib.RingTheory.Polynomial.GaussLemma #align_import field_theory.minpoly.is_integrally_closed from "leanprover-community/mathlib"@"f0c8bf9245297a541f468be517f1bde6195105e9" open scoped Classical Polynomial open Polynomial Set...
Mathlib/FieldTheory/Minpoly/IsIntegrallyClosed.lean
138
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theorem prime_of_isIntegrallyClosed {x : S} (hx : IsIntegral R x) : Prime (minpoly R x) := by
refine ⟨(minpoly.monic hx).ne_zero, ⟨fun h_contra => (ne_of_lt (minpoly.degree_pos hx)) (degree_eq_zero_of_isUnit h_contra).symm, fun a b h => or_iff_not_imp_left.mpr fun h' => ?_⟩⟩ rw [← minpoly.isIntegrallyClosed_dvd_iff hx] at h' h ⊢ rw [aeval_mul] at h exact eq_zero_of_ne_zero_of_mul_left...
2,024
import Mathlib.RingTheory.RootsOfUnity.Basic import Mathlib.FieldTheory.Minpoly.IsIntegrallyClosed import Mathlib.Algebra.GCDMonoid.IntegrallyClosed import Mathlib.FieldTheory.Finite.Basic #align_import ring_theory.roots_of_unity.minpoly from "leanprover-community/mathlib"@"7fdeecc0d03cd40f7a165e6cf00a4d2286db599f" ...
Mathlib/RingTheory/RootsOfUnity/Minpoly.lean
40
45
theorem isIntegral (hpos : 0 < n) : IsIntegral ℤ μ := by
use X ^ n - 1 constructor · exact monic_X_pow_sub_C 1 (ne_of_lt hpos).symm · simp only [((IsPrimitiveRoot.iff_def μ n).mp h).left, eval₂_one, eval₂_X_pow, eval₂_sub, sub_self]
2,025
import Mathlib.RingTheory.RootsOfUnity.Basic import Mathlib.FieldTheory.Minpoly.IsIntegrallyClosed import Mathlib.Algebra.GCDMonoid.IntegrallyClosed import Mathlib.FieldTheory.Finite.Basic #align_import ring_theory.roots_of_unity.minpoly from "leanprover-community/mathlib"@"7fdeecc0d03cd40f7a165e6cf00a4d2286db599f" ...
Mathlib/RingTheory/RootsOfUnity/Minpoly.lean
53
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theorem minpoly_dvd_x_pow_sub_one : minpoly ℤ μ ∣ X ^ n - 1 := by
rcases n.eq_zero_or_pos with (rfl | h0) · simp apply minpoly.isIntegrallyClosed_dvd (isIntegral h h0) simp only [((IsPrimitiveRoot.iff_def μ n).mp h).left, aeval_X_pow, eq_intCast, Int.cast_one, aeval_one, AlgHom.map_sub, sub_self]
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import Mathlib.RingTheory.RootsOfUnity.Basic import Mathlib.FieldTheory.Minpoly.IsIntegrallyClosed import Mathlib.Algebra.GCDMonoid.IntegrallyClosed import Mathlib.FieldTheory.Finite.Basic #align_import ring_theory.roots_of_unity.minpoly from "leanprover-community/mathlib"@"7fdeecc0d03cd40f7a165e6cf00a4d2286db599f" ...
Mathlib/RingTheory/RootsOfUnity/Minpoly.lean
63
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theorem separable_minpoly_mod {p : ℕ} [Fact p.Prime] (hdiv : ¬p ∣ n) : Separable (map (Int.castRingHom (ZMod p)) (minpoly ℤ μ)) := by
have hdvd : map (Int.castRingHom (ZMod p)) (minpoly ℤ μ) ∣ X ^ n - 1 := by convert RingHom.map_dvd (mapRingHom (Int.castRingHom (ZMod p))) (minpoly_dvd_x_pow_sub_one h) simp only [map_sub, map_pow, coe_mapRingHom, map_X, map_one] refine Separable.of_dvd (separable_X_pow_sub_C 1 ?_ one_ne_zero) hdvd...
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import Mathlib.RingTheory.RootsOfUnity.Basic import Mathlib.FieldTheory.Minpoly.IsIntegrallyClosed import Mathlib.Algebra.GCDMonoid.IntegrallyClosed import Mathlib.FieldTheory.Finite.Basic #align_import ring_theory.roots_of_unity.minpoly from "leanprover-community/mathlib"@"7fdeecc0d03cd40f7a165e6cf00a4d2286db599f" ...
Mathlib/RingTheory/RootsOfUnity/Minpoly.lean
82
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theorem minpoly_dvd_expand {p : ℕ} (hdiv : ¬p ∣ n) : minpoly ℤ μ ∣ expand ℤ p (minpoly ℤ (μ ^ p)) := by
rcases n.eq_zero_or_pos with (rfl | hpos) · simp_all letI : IsIntegrallyClosed ℤ := GCDMonoid.toIsIntegrallyClosed refine minpoly.isIntegrallyClosed_dvd (h.isIntegral hpos) ?_ rw [aeval_def, coe_expand, ← comp, eval₂_eq_eval_map, map_comp, Polynomial.map_pow, map_X, eval_comp, eval_pow, eval_X, ← eval₂_e...
2,025