mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.FieldTheory.Finite.Basic

Goal state before:
pp: case succ.zero
p a d k : ℕ
hk : k ∈ range p
hd : (1 + p * a) ^ p ^ 0 = p ^ 0 * d + 1
⊢ p ∣ (p ^ 0 * d) ^ k * ↑(p.choose (k + 1))

Tactic:
pow_zero,

Goal state after:
case succ.zero
p a d k : ℕ
hk : k ∈ range p
hd : (1 + p * a) ^ 1 = 1 * d + 1
⊢ p ∣ (p ^ 0 * d) ^ k * ↑(p.choose (k + 1))
Module: Mathlib.RingTheory.Invariant.Basic

Goal state before:
pp: A : Type u_1
B : Type u_2
k : Type u_3
inst✝¹³ : CommRing A
inst✝¹² : CommRing B
inst✝¹¹ : Algebra A B
G : Type u_4
inst✝¹⁰ : Finite G
inst✝⁹ : Group G
inst✝⁸ : MulSemiringAction G B
inst✝⁷ : Algebra.IsInvariant A B G
P✝ : Ideal A
Q : Ideal B
inst✝⁶ : Q.LiesOver P✝
inst✝⁵ : CommRing k
inst✝⁴ : Algebra (A ⧸ P✝) k
inst✝³ : Algebra (B ⧸ Q) k
inst✝² : IsScalarTower (A ⧸ P✝) (B ⧸ Q) k
inst✝¹ : IsDomain k
inst✝ : FaithfulSMul (B ⧸ Q) k
σ : k →ₐ[A ⧸ P✝] k
f : B ⧸ Q →ₐ[A ⧸ P✝] k := IsScalarTower.toAlgHom (A ⧸ P✝) (B ⧸ Q) k
hf : Function.Injective ⇑f
x : B
val✝ : Fintype G
algInst✝¹ : Algebra A k := ((algebraMap (A ⧸ P✝) k).comp (algebraMap A (A ⧸ P✝))).toAlgebra
algInst✝ : Algebra B k := ((algebraMap (B ⧸ Q) k).comp (algebraMap B (B ⧸ Q))).toAlgebra
scalarTowerInst✝¹ : IsScalarTower A (A ⧸ P✝) k := IsScalarTower.of_algebraMap_eq' (Eq.refl (algebraMap A k))
scalarTowerInst✝ : IsScalarTower B (B ⧸ Q) k := IsScalarTower.of_algebraMap_eq' (Eq.refl (algebraMap B k))
this✝ : IsScalarTower A (B ⧸ Q) k
this : IsScalarTower A B k
P : Polynomial A
hp : (Polynomial.mapRingHom (algebraMap A B)) P = MulSemiringAction.charpoly G x
⊢ (Polynomial.aeval x) P = 0

Tactic:
Polynomial.aeval_def,

Goal state after:
A : Type u_1
B : Type u_2
k : Type u_3
inst✝¹³ : CommRing A
inst✝¹² : CommRing B
inst✝¹¹ : Algebra A B
G : Type u_4
inst✝¹⁰ : Finite G
inst✝⁹ : Group G
inst✝⁸ : MulSemiringAction G B
inst✝⁷ : Algebra.IsInvariant A B G
P✝ : Ideal A
Q : Ideal B
inst✝⁶ : Q.LiesOver P✝
inst✝⁵ : CommRing k
inst✝⁴ : Algebra (A ⧸ P✝) k
inst✝³ : Algebra (B ⧸ Q) k
inst✝² : IsScalarTower (A ⧸ P✝) (B ⧸ Q) k
inst✝¹ : IsDomain k
inst✝ : FaithfulSMul (B ⧸ Q) k
σ : k →ₐ[A ⧸ P✝] k
f : B ⧸ Q →ₐ[A ⧸ P✝] k := IsScalarTower.toAlgHom (A ⧸ P✝) (B ⧸ Q) k
hf : Function.Injective ⇑f
x : B
val✝ : Fintype G
algInst✝¹ : Algebra A k := ((algebraMap (A ⧸ P✝) k).comp (algebraMap A (A ⧸ P✝))).toAlgebra
algInst✝ : Algebra B k := ((algebraMap (B ⧸ Q) k).comp (algebraMap B (B ⧸ Q))).toAlgebra
scalarTowerInst✝¹ : IsScalarTower A (A ⧸ P✝) k := IsScalarTower.of_algebraMap_eq' (Eq.refl (algebraMap A k))
scalarTowerInst✝ : IsScalarTower B (B ⧸ Q) k := IsScalarTower.of_algebraMap_eq' (Eq.refl (algebraMap B k))
this✝ : IsScalarTower A (B ⧸ Q) k
this : IsScalarTower A B k
P : Polynomial A
hp : (Polynomial.mapRingHom (algebraMap A B)) P = MulSemiringAction.charpoly G x
⊢ Polynomial.eval₂ (algebraMap A B) x P = 0
Module: Mathlib.RingTheory.UniqueFactorizationDomain.Multiplicative

Goal state before:
pp: α : Type u_1
inst✝² : CommMonoidWithZero α
inst✝¹ : UniqueFactorizationMonoid α
β : Type u_3
inst✝ : CommMonoidWithZero β
f : α → β
s : Finset α
i j : α → ℕ
is_prime : ∀ p ∈ s, Prime p
is_coprime : ∀ p ∈ s, ∀ q ∈ s, p ∣ q → p = q
h1 : ∀ {x y : α}, IsUnit y → f (x * y) = f x * f y
hpr : ∀ {p : α} (i : ℕ), Prime p → f (p ^ i) = f p ^ i
hcp : ∀ {x y : α}, IsRelPrime x y → f (x * y) = f x * f y
⊢ f (∏ p ∈ s, p ^ (i p + j p)) = f (∏ p ∈ s, p ^ i p) * f (∏ p ∈ s, p ^ j p)

Tactic:
let := Classical.decEq α
  induction s using Finset.induction_on with
  | empty => simpa using h1 isUnit_one
  | insert p s hps ih =>
    have hpr_p := is_prime _ (Finset.mem_insert_self _ _)
    have hpr_s : ∀ p ∈ s, Prime p := fun p hp => is_prime _ (Finset.mem_insert_of_mem hp)
    have hcp_p := fun i => prime_pow_coprime_prod_of_coprime_insert i p hps is_prime is_coprime
    have hcp_s : ∀ᵉ (p ∈ s) (q ∈ s), p ∣ q → p = q := fun p hp q hq =>
      is_coprime p (Finset.mem_insert_of_mem hp) q (Finset.mem_insert_of_mem hq)
    rw [Finset.prod_insert hps, Finset.prod_insert hps, Finset.prod_insert hps, hcp (hcp_p _),
      hpr _ hpr_p, hcp (hcp_p _), hpr _ hpr_p, hcp (hcp_p (fun p => i p + j p)), hpr _ hpr_p,
      ih hpr_s hcp_s, pow_add, mul_assoc, mul_left_comm (f p ^ j p), mul_assoc]

Goal state after:
Module: Mathlib.RingTheory.Norm.Basic

Goal state before:
pp: K : Type u_4
L : Type u_5
F : Type u_6
inst✝¹¹ : Field K
inst✝¹⁰ : Field L
inst✝⁹ : Field F
inst✝⁸ : Algebra K L
inst✝⁷ : Algebra K F
E : Type u_7
inst✝⁶ : Field E
inst✝⁵ : Algebra K E
inst✝⁴ : Algebra L F
inst✝³ : IsScalarTower K L F
inst✝² : IsAlgClosed E
inst✝¹ : Algebra.IsSeparable K F
inst✝ : FiniteDimensional K F
pb : PowerBasis K L
this✝¹ : FiniteDimensional L F
this✝ : Algebra.IsSeparable L F
this : Fintype (L →ₐ[K] E) := PowerBasis.AlgHom.fintype pb
⊢ ∀ (x : F →ₐ[K] E), x ((algebraMap L F) pb.gen) = (algHomEquivSigma x).fst pb.gen

Tactic:
· intro σ
    simp only [algHomEquivSigma, Equiv.coe_fn_mk, AlgHom.domRestrict, AlgHom.comp_apply,
      IsScalarTower.coe_toAlgHom']

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Inertia

Goal state before:
pp: R : Type u
inst✝⁴ : CommRing R
inst✝³ : IsDedekindDomain R
inst✝² : Free ℤ R
inst✝¹ : Module.Finite ℤ R
p : ℤ
P : Ideal R
inst✝ : P.LiesOver (span {p})
hp : Prime p
⊢ (span {p}).IsPrime

Tactic:
rwa [span_singleton_prime hp.ne_zero]

Goal state after:
Module: Mathlib.RingTheory.Noetherian.Nilpotent

Goal state before:
pp: R : Type u_1
inst✝¹ : CommSemiring R
inst✝ : IsNoetherianRing R
⊢ IsNilpotent (nilradical R)

Tactic:
by
  obtain ⟨n, hn⟩ := Ideal.exists_radical_pow_le_of_fg (⊥ : Ideal R) (IsNoetherian.noetherian _)
  exact ⟨n, eq_bot_iff.mpr hn⟩

Goal state after:
Module: Mathlib.RingTheory.Finiteness.NilpotentKer

Goal state before:
pp: case zero
R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : Algebra R S
inst✝¹ : Algebra R T
inst✝ : Module.Finite R T
f : S →ₐ[R] T
hf₁ : Function.Surjective ⇑f
I : Ideal S
hI : RingHom.ker f = I
hf₂ : I ≤ nilradical S
hf₃ : I.FG
this : Module.Finite R (S ⧸ I)
⊢ Module.Finite R (S ⧸ I ^ 0)

Tactic:
pow_zero,

Goal state after:
case zero
R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : Algebra R S
inst✝¹ : Algebra R T
inst✝ : Module.Finite R T
f : S →ₐ[R] T
hf₁ : Function.Surjective ⇑f
I : Ideal S
hI : RingHom.ker f = I
hf₂ : I ≤ nilradical S
hf₃ : I.FG
this : Module.Finite R (S ⧸ I)
⊢ Module.Finite R (S ⧸ 1)
Module: Mathlib.RingTheory.Ideal.Norm.AbsNorm

Goal state before:
pp: case succ.refine_2
S : Type u_1
inst✝¹ : CommRing S
P : Ideal S
P_prime : P.IsPrime
inst✝ : IsDedekindDomain S
hP : P ≠ ⊥
i : ℕ
ih : cardQuot (P ^ i) = cardQuot P ^ i
this : P ^ (i + 1) < P ^ i
a : S
a_mem : a ∈ P ^ i
a_notMem : a ∉ P ^ (i + 1)
f g : (c : S) → c ∈ P ^ i → S
hg : ∀ (c : S) (hc : c ∈ P ^ i), g c hc ∈ P ^ (i + 1)
hf : ∀ (c : S) (hc : c ∈ P ^ i), a * f c hc + g c hc = c
k : (c' : S ⧸ P ^ i.succ) → c' ∈ map (mkQ (P ^ i.succ)) (P ^ i) → S
hk_mem : ∀ (c' : S ⧸ P ^ i.succ) (hc' : c' ∈ map (mkQ (P ^ i.succ)) (P ^ i)), k c' hc' ∈ P ^ i
hk_eq : ∀ (c' : S ⧸ P ^ i.succ) (hc' : c' ∈ map (mkQ (P ^ i.succ)) (P ^ i)), (mkQ (P ^ i.succ)) (k c' hc') = c'
⊢ Function.Surjective fun c' ↦ Quotient.mk'' (f (k ↑c' ⋯) ⋯)

Tactic:
· intro d'
    induction d' using Quotient.inductionOn with | _ d
    have hd' := (mem_map (f := mkQ (P ^ i.succ))).mpr ⟨a * d, Ideal.mul_mem_right d _ a_mem, rfl⟩
    refine ⟨⟨_, hd'⟩, ?_⟩
    simp only [Submodule.Quotient.mk''_eq_mk, Ideal.Quotient.mk_eq_mk, Ideal.Quotient.eq]
    refine
      Ideal.mul_add_mem_pow_succ_unique hP a _ _ _ _ a_notMem (hg _ (hk_mem _ hd')) (zero_mem _) ?_
    rw [hf, add_zero]
    exact (Submodule.Quotient.eq _).mp (hk_eq _ hd')

Goal state after:
Module: Mathlib.RingTheory.Ideal.Norm.AbsNorm

Goal state before:
pp: case hJ
S : Type u_1
inst✝² : CommRing S
inst✝¹ : IsDedekindDomain S
inst✝ : Free ℤ S
I : Ideal S
hI : Nat.Prime (absNorm I)
this : (span {↑(absNorm I)}).IsPrime
⊢ comap (algebraMap ℤ S) I ≠ ⊤

pp: case IJ
S : Type u_1
inst✝² : CommRing S
inst✝¹ : IsDedekindDomain S
inst✝ : Free ℤ S
I : Ideal S
hI : Nat.Prime (absNorm I)
this : (span {↑(absNorm I)}).IsPrime
⊢ span {↑(absNorm I)} ≤ comap (algebraMap ℤ S) I

pp: S : Type u_1
inst✝² : CommRing S
inst✝¹ : IsDedekindDomain S
inst✝ : Free ℤ S
I : Ideal S
hI : Nat.Prime (absNorm I)
this : (span {↑(absNorm I)}).IsPrime
⊢ span {↑(absNorm I)} ≠ ⊥

Tactic:
· exact ((isPrime_of_irreducible_absNorm
      ((Nat.irreducible_iff_nat_prime _).mpr hI)).comap (algebraMap ℤ S)).ne_top

Goal state after:
case IJ
S : Type u_1
inst✝² : CommRing S
inst✝¹ : IsDedekindDomain S
inst✝ : Free ℤ S
I : Ideal S
hI : Nat.Prime (absNorm I)
this : (span {↑(absNorm I)}).IsPrime
⊢ span {↑(absNorm I)} ≤ comap (algebraMap ℤ S) I

S : Type u_1
inst✝² : CommRing S
inst✝¹ : IsDedekindDomain S
inst✝ : Free ℤ S
I : Ideal S
hI : Nat.Prime (absNorm I)
this : (span {↑(absNorm I)}).IsPrime
⊢ span {↑(absNorm I)} ≠ ⊥
Module: Mathlib.RingTheory.Ideal.Norm.AbsNorm

Goal state before:
pp: case h₁
S : Type u_1
inst✝³ : CommRing S
inst✝² : IsDedekindDomain S
inst✝¹ : Free ℤ S
inst✝ : Module.Finite ℤ S
p : ℤ
hp : Prime p
this✝ : IsAddTorsionFree S
this : CharZero S
hpMax : (span {p}).IsMaximal
hI : p ∣ ↑(absNorm 0)
⊢ ∃ P, P.IsMaximal ∧ under ℤ P = span {p} ∧ P ∣ 0

Tactic:
obtain ⟨Q, hQ, e⟩ := Ideal.exists_ideal_over_maximal_of_isIntegral (S := S) (Ideal.span {p})
      (fun x ↦ by simp +contextual)
    exact ⟨Q, hQ, e, dvd_zero _⟩

Goal state after:
Module: Mathlib.RingTheory.Localization.InvSubmonoid

Goal state before:
pp: R : Type u_1
inst✝³ : CommRing R
M : Submonoid R
S : Type u_2
inst✝² : CommRing S
inst✝¹ : Algebra R S
inst✝ : IsLocalization M S
x : S
⊢ x ∈ invSubmonoid M S ↔ ∃ m, ↑((toInvSubmonoid M S) m) = x

Tactic:
exact ⟨fun h => ⟨_, congr_arg Subtype.val (toInvSubmonoid_surjective M S ⟨x, h⟩).choose_spec⟩,
    fun h => h.choose_spec ▸ (toInvSubmonoid M S h.choose).prop⟩

Goal state after:
Module: Mathlib.RingTheory.Localization.InvSubmonoid

Goal state before:
pp: R : Type u_1
inst✝³ : CommRing R
M : Submonoid R
S : Type u_2
inst✝² : CommRing S
inst✝¹ : Algebra R S
inst✝ : IsLocalization M S
⊢ Submodule.span R ↑(invSubmonoid M S) = ⊤

Tactic:
by
  rw [eq_top_iff]
  rintro x -
  rcases IsLocalization.surj'' M x with ⟨r, m, rfl⟩
  exact Submodule.smul_mem _ _ (Submodule.subset_span (toInvSubmonoid M S m).prop)

Goal state after:
Module: Mathlib.RingTheory.HopkinsLevitzki

Goal state before:
pp: M : Type u
inst✝⁴ : AddCommGroup M
R : Type u_3
inst✝³ : CommRing R
inst✝² : Module R M
inst✝¹ : Module.Finite R M
inst✝ : IsArtinian R M
s : Set M
fin : Finite ↑s
span : ⨆ i, R ∙ ↑i = ⊤
i : M
⊢ IsNoetherian R ↥(R ∙ i)

Tactic:
LinearMap.span_singleton_eq_range,

Goal state after:
M : Type u
inst✝⁴ : AddCommGroup M
R : Type u_3
inst✝³ : CommRing R
inst✝² : Module R M
inst✝¹ : Module.Finite R M
inst✝ : IsArtinian R M
s : Set M
fin : Finite ↑s
span : ⨆ i, R ∙ ↑i = ⊤
i : M
⊢ IsNoetherian R ↥(LinearMap.toSpanSingleton R M i).range
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝² : CommRing R
S : Type v
inst✝¹ : CommRing S
inst✝ : Algebra R S
p : Ideal R
P : Ideal S
h : ∀ (n : ℕ), ∃ k, map f p ≤ P ^ k ∧ n < k
⊢ ¬∃ n, ∀ a ∈ {n | map f p ≤ P ^ n}, a ≤ n

Tactic:
push Not

Goal state after:
R : Type u
inst✝² : CommRing R
S : Type v
inst✝¹ : CommRing S
inst✝ : Algebra R S
p : Ideal R
P : Ideal S
h : ∀ (n : ℕ), ∃ k, map f p ≤ P ^ k ∧ n < k
⊢ ∀ (n : ℕ), ∃ a ∈ {n | map f p ≤ P ^ n}, n < a
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: case succ
R : Type u
inst✝² : CommRing R
S : Type v
inst✝¹ : CommRing S
inst✝ : Algebra R S
p : Ideal R
P : Ideal S
n : ℕ
hgt : ¬map f p ≤ P ^ (n + 1)
⊢ p.ramificationIdx' P < n + 1

Tactic:
rw [Nat.lt_succ_iff]
    have : ∀ k, map f p ≤ P ^ k → k ≤ n := by
      refine fun k hk => le_of_not_gt fun hnk => ?_
      exact hgt (hk.trans (Ideal.pow_le_pow_right hnk))
    rw [ramificationIdx'_eq_find ⟨n, this⟩]
    exact Nat.find_min' ⟨n, this⟩ this

Goal state after:
Module: Mathlib.RingTheory.Unramified.Basic

Goal state before:
pp: R : Type v
inst✝⁵ : CommRing R
A : Type u
inst✝⁴ : CommRing A
inst✝³ : Algebra R A
B : Type w
inst✝² : CommRing B
inst✝¹ : Algebra R B
I : Ideal B
inst✝ : FormallyUnramified R A
hI : ⨅ i, I ^ i = ⊥
g₁ g₂ : A →ₐ[R] B
H : ∀ (x : A), (Ideal.Quotient.mk I) (g₁ x) = (Ideal.Quotient.mk I) (g₂ x)
i : ℕ
hi : i = 0
x : A
⊢ Subsingleton (B ⧸ I ^ 0)

Tactic:
pow_zero,

Goal state after:
R : Type v
inst✝⁵ : CommRing R
A : Type u
inst✝⁴ : CommRing A
inst✝³ : Algebra R A
B : Type w
inst✝² : CommRing B
inst✝¹ : Algebra R B
I : Ideal B
inst✝ : FormallyUnramified R A
hI : ⨅ i, I ^ i = ⊥
g₁ g₂ : A →ₐ[R] B
H : ∀ (x : A), (Ideal.Quotient.mk I) (g₁ x) = (Ideal.Quotient.mk I) (g₂ x)
i : ℕ
hi : i = 0
x : A
⊢ Subsingleton (B ⧸ 1)
Module: Mathlib.RingTheory.Unramified.Basic

Goal state before:
pp: R : Type u_1
inst✝⁷ : CommRing R
A : Type u_2
B : Type u_3
inst✝⁶ : CommRing A
inst✝⁵ : Algebra R A
inst✝⁴ : CommRing B
inst✝³ : Algebra R B
inst✝² : FormallyUnramified R A
f : A →ₐ[R] B
H : Function.Surjective ⇑f
Q : Type u_3
inst✝¹ : CommRing Q
inst✝ : Algebra R Q
I : Ideal Q
hI : I ^ 2 = ⊥
f₁ f₂ : B →ₐ[R] Q
e : (Ideal.Quotient.mkₐ R I).comp f₁ = (Ideal.Quotient.mkₐ R I).comp f₂
x✝ x : A
⊢ ((Ideal.Quotient.mkₐ R I).comp (f₁.comp f)) x = ((Ideal.Quotient.mkₐ R I).comp (f₂.comp f)) x

Tactic:
exact DFunLike.congr_fun e (f x)

Goal state after:
Module: Mathlib.RingTheory.QuasiFinite.Basic

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : Algebra R S
inst✝¹ : IsArtinianRing R
inst✝ : QuasiFinite R S
e : R ≃ₐ[R] PrimeSpectrum.PiLocalization R :=
  AlgEquiv.ofBijective (IsScalarTower.toAlgHom R R (PrimeSpectrum.PiLocalization R)) ⋯
this✝ : Fintype (PrimeSpectrum R)
e' : S ≃ₐ[R] (p : PrimeSpectrum R) → Localization p.asIdeal.primeCompl ⊗[R] S :=
  (TensorProduct.rid R R S).symm.trans
    ((TensorProduct.congr AlgEquiv.refl e).trans
      ((TensorProduct.piRight R R S fun p ↦ Localization p.asIdeal.primeCompl).trans
        (AlgEquiv.piCongrRight fun x ↦ TensorProduct.comm R S (Localization x.asIdeal.primeCompl))))
this : ∀ (p : PrimeSpectrum R), Module.Finite R (Localization p.asIdeal.primeCompl ⊗[R] S)
⊢ Module.Finite R S

Tactic:
exact .of_surjective e'.symm.toLinearMap e'.symm.surjective

Goal state after:
Module: Mathlib.RingTheory.QuasiFinite.Basic

Goal state before:
pp: case e'_2
R : Type u_1
S : Type u_2
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : Algebra R S
P Q : Ideal S
inst✝² : P.IsPrime
inst✝¹ : Q.IsPrime
h₁ : P ≤ Q
h₂ : Ideal.under R P = Ideal.under R Q
inst✝ : QuasiFiniteAt R Q
this : (Ideal.map (algebraMap S (Localization.AtPrime Q)) P).IsPrime
⊢ Ideal.under R (Ideal.under S (Ideal.map (algebraMap S (Localization.AtPrime Q)) P)) = Ideal.under R P

Tactic:
Q.under_map_of_isLocalizationAtPrime h₁

Goal state after:
case e'_2
R : Type u_1
S : Type u_2
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : Algebra R S
P Q : Ideal S
inst✝² : P.IsPrime
inst✝¹ : Q.IsPrime
h₁ : P ≤ Q
h₂ : Ideal.under R P = Ideal.under R Q
inst✝ : QuasiFiniteAt R Q
this : (Ideal.map (algebraMap S (Localization.AtPrime Q)) P).IsPrime
⊢ Ideal.under R P = Ideal.under R P
Module: Mathlib.RingTheory.QuasiFinite.Basic

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : Algebra R S
P Q : Ideal S
inst✝² : P.IsPrime
inst✝¹ : Q.IsPrime
h₁ : P ≤ Q
h₂ : Ideal.under R P = Ideal.under R Q
inst✝ : QuasiFiniteAt R Q
this : (Ideal.map (algebraMap S (Localization.AtPrime Q)) P).IsPrime
H : Ideal.map (algebraMap S (Localization.AtPrime Q)) P = IsLocalRing.maximalIdeal (Localization.AtPrime Q)
⊢ P = Ideal.under S (Ideal.map (algebraMap S (Localization.AtPrime Q)) P)

Tactic:
Q.under_map_of_isLocalizationAtPrime h₁

Goal state after:
R : Type u_1
S : Type u_2
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : Algebra R S
P Q : Ideal S
inst✝² : P.IsPrime
inst✝¹ : Q.IsPrime
h₁ : P ≤ Q
h₂ : Ideal.under R P = Ideal.under R Q
inst✝ : QuasiFiniteAt R Q
this : (Ideal.map (algebraMap S (Localization.AtPrime Q)) P).IsPrime
H : Ideal.map (algebraMap S (Localization.AtPrime Q)) P = IsLocalRing.maximalIdeal (Localization.AtPrime Q)
⊢ P = P
Module: Mathlib.RingTheory.QuasiFinite.Basic

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝⁹ : CommRing R
inst✝⁸ : CommRing S
inst✝⁷ : Algebra R S
inst✝⁶ : FiniteType R S
p : Ideal R
inst✝⁵ : p.IsPrime
q : Ideal S
inst✝⁴ : q.IsPrime
inst✝³ : q.LiesOver p
inst✝² : QuasiFiniteAt R q
inst✝¹ : Algebra (Localization.AtPrime p) (Localization.AtPrime q)
inst✝ : Localization.AtPrime.IsLiesOverAlgebra p q
q' : Ideal (p.Fiber S) := ((PrimeSpectrum.primesOverOrderIsoFiber R S p) ⟨q, ⋯⟩).asIdeal
⊢ Function.Surjective
    ⇑(TensorProduct.lift (ofId p.ResidueField q.ResidueField) (IsScalarTower.toAlgHom R S q.ResidueField) ⋯)

Tactic:
have hq' : q = q'.comap Algebra.TensorProduct.includeRight.toRingHom :=
    congr($((PrimeSpectrum.primesOverOrderIsoFiber R S p).symm_apply_apply ⟨q, ‹_›, ‹_›⟩).1).symm

Goal state after:
R : Type u_1
S : Type u_2
inst✝⁹ : CommRing R
inst✝⁸ : CommRing S
inst✝⁷ : Algebra R S
inst✝⁶ : FiniteType R S
p : Ideal R
inst✝⁵ : p.IsPrime
q : Ideal S
inst✝⁴ : q.IsPrime
inst✝³ : q.LiesOver p
inst✝² : QuasiFiniteAt R q
inst✝¹ : Algebra (Localization.AtPrime p) (Localization.AtPrime q)
inst✝ : Localization.AtPrime.IsLiesOverAlgebra p q
q' : Ideal (p.Fiber S) := ((PrimeSpectrum.primesOverOrderIsoFiber R S p) ⟨q, ⋯⟩).asIdeal
hq' : q = Ideal.comap TensorProduct.includeRight.toRingHom q'
⊢ Function.Surjective
    ⇑(TensorProduct.lift (ofId p.ResidueField q.ResidueField) (IsScalarTower.toAlgHom R S q.ResidueField) ⋯)
Module: Mathlib.RingTheory.Unramified.Locus

Goal state before:
pp: R : Type u_1
A : Type u_2
inst✝⁵ : CommRing R
inst✝⁴ : CommRing A
inst✝³ : Algebra R A
inst✝² : EssFiniteType R A
p : Ideal A
inst✝¹ : p.IsPrime
inst✝ : IsUnramifiedAt R p
⊢ ∃ f ∉ p, FormallyUnramified R (Localization.Away f)

Tactic:
obtain ⟨_, ⟨_, ⟨r, rfl⟩, rfl⟩, hpr, hr⟩ :=
    PrimeSpectrum.isBasis_basic_opens.exists_subset_of_mem_open
      (show ⟨p, ‹_›⟩ ∈ unramifiedLocus R A from ‹_›) isOpen_unramifiedLocus
  exact ⟨r, hpr, basicOpen_subset_unramifiedLocus_iff.mp hr⟩

Goal state after:
Module: Mathlib.RingTheory.Smooth.Kaehler

Goal state before:
pp: case e_a
R : Type u_1
P : Type u_2
S : Type u_3
inst✝⁶ : CommRing R
inst✝⁵ : CommRing P
inst✝⁴ : CommRing S
inst✝³ : Algebra R P
inst✝² : Algebra P S
inst✝¹ : Algebra R S
inst✝ : IsScalarTower R P S
g : S →ₐ[R] P
hf' : RingHom.ker (algebraMap P S) ^ 2 = ⊥
hg : (IsScalarTower.toAlgHom R P S).comp g = AlgHom.id R S
this : Algebra S P := g.toAlgebra
p : P
s : S
m : ↥(RingHom.ker (algebraMap P S))
⊢ g ((algebraMap P S) p) - p ∈ RingHom.ker (algebraMap P S)

Tactic:
simpa [RingHom.mem_ker, sub_eq_zero] using AlgHom.congr_fun hg (algebraMap P S p)

Goal state after:
Module: Mathlib.RingTheory.Unramified.Field

Goal state before:
pp: K : Type u_1
A : Type u_2
inst✝⁶ : Field K
inst✝⁵ : CommRing A
inst✝⁴ : Algebra K A
inst✝³ : FormallyUnramified K A
inst✝² : EssFiniteType K A
inst✝¹ : IsAlgClosed K
inst✝ : IsLocalRing A
this✝ : Module.Finite K A
this : IsArtinianRing A
hA : IsNilpotent (IsLocalRing.maximalIdeal A)
e : K ≃ₐ[K] A ⧸ IsLocalRing.maximalIdeal A :=
  let __spread.0 := ofId K (A ⧸ IsLocalRing.maximalIdeal A);
  let __spread.1 := Equiv.ofBijective ⇑(algebraMap K (A ⧸ IsLocalRing.maximalIdeal A)) ⋯;
  { toFun := (↑↑__spread.0.toRingHom).toFun, invFun := __spread.1.invFun, left_inv := ⋯, right_inv := ⋯, map_mul' := ⋯,
    map_add' := ⋯, commutes' := ⋯ }
⊢ Function.Bijective ⇑(algebraMap K A)

Tactic:
let e' : A ⊗[K] (A ⧸ IsLocalRing.maximalIdeal A) ≃ₐ[A] A :=
    (Algebra.TensorProduct.congr AlgEquiv.refl e.symm).trans (Algebra.TensorProduct.rid K A A)

Goal state after:
K : Type u_1
A : Type u_2
inst✝⁶ : Field K
inst✝⁵ : CommRing A
inst✝⁴ : Algebra K A
inst✝³ : FormallyUnramified K A
inst✝² : EssFiniteType K A
inst✝¹ : IsAlgClosed K
inst✝ : IsLocalRing A
this✝ : Module.Finite K A
this : IsArtinianRing A
hA : IsNilpotent (IsLocalRing.maximalIdeal A)
e : K ≃ₐ[K] A ⧸ IsLocalRing.maximalIdeal A :=
  let __spread.0 := ofId K (A ⧸ IsLocalRing.maximalIdeal A);
  let __spread.1 := Equiv.ofBijective ⇑(algebraMap K (A ⧸ IsLocalRing.maximalIdeal A)) ⋯;
  { toFun := (↑↑__spread.0.toRingHom).toFun, invFun := __spread.1.invFun, left_inv := ⋯, right_inv := ⋯, map_mul' := ⋯,
    map_add' := ⋯, commutes' := ⋯ }
e' : A ⊗[K] (A ⧸ IsLocalRing.maximalIdeal A) ≃ₐ[A] A :=
  (TensorProduct.congr AlgEquiv.refl e.symm).trans (TensorProduct.rid K A A)
⊢ Function.Bijective ⇑(algebraMap K A)
Module: Mathlib.RingTheory.Kaehler.JacobiZariski

Goal state before:
pp: case h
R : Type u₁
S : Type u₂
inst✝⁶ : CommRing R
inst✝⁵ : CommRing S
inst✝⁴ : Algebra R S
T : Type u₃
inst✝³ : CommRing T
inst✝² : Algebra R T
inst✝¹ : Algebra S T
inst✝ : IsScalarTower R S T
ι : Type w₁
σ : Type w₂
Q : Generators S T ι
P : Generators R S σ
⊢ Function.Surjective ⇑(LinearMap.baseChange T P.toExtension.toKaehler)

Tactic:
exact LinearMap.lTensor_surjective T P.toExtension.toKaehler_surjective

Goal state after:
Module: Mathlib.RingTheory.Smooth.Kaehler

Goal state before:
pp: R : Type u_1
P : Type u_2
S : Type u_3
inst✝⁶ : CommRing R
inst✝⁵ : CommRing P
inst✝⁴ : CommRing S
inst✝³ : Algebra R P
inst✝² : Algebra P S
inst✝¹ : Algebra R S
inst✝ : IsScalarTower R P S
hf' : RingHom.ker (algebraMap P S) ^ 2 = ⊥
hf : Surjective ⇑(algebraMap P S)
P' : Type u_2 := P ⧸ RingHom.ker (algebraMap P S) ^ 2
h₁ : Surjective ⇑(algebraMap P' S)
h₂ : RingHom.ker (algebraMap P' S) ^ 2 = ⊥
e₁ : (RingHom.ker (algebraMap P S)).Cotangent ≃ₗ[P] ↥(RingHom.ker (algebraMap P' S)) :=
  (RingHom.ker (algebraMap P S)).cotangentEquivIdeal ≪≫ₗ
    LinearEquiv.restrictScalars P
      (LinearEquiv.ofEq (RingHom.ker (IsScalarTower.toAlgHom R P S).toRingHom).cotangentIdeal
        (RingHom.ker (IsScalarTower.toAlgHom R P S).kerSquareLift.toRingHom) ⋯)
⊢ { l // l ∘ₗ kerCotangentToTensor R P S = LinearMap.id } ≃
    { g // (IsScalarTower.toAlgHom R P S).kerSquareLift.comp g = AlgHom.id R S }

Tactic:
let e₂ : S ⊗[P'] Ω[P'⁄R] ≃ₗ[P] S ⊗[P] Ω[P⁄R] :=
    (tensorKaehlerQuotKerSqEquiv R P S).restrictScalars P

Goal state after:
R : Type u_1
P : Type u_2
S : Type u_3
inst✝⁶ : CommRing R
inst✝⁵ : CommRing P
inst✝⁴ : CommRing S
inst✝³ : Algebra R P
inst✝² : Algebra P S
inst✝¹ : Algebra R S
inst✝ : IsScalarTower R P S
hf' : RingHom.ker (algebraMap P S) ^ 2 = ⊥
hf : Surjective ⇑(algebraMap P S)
P' : Type u_2 := P ⧸ RingHom.ker (algebraMap P S) ^ 2
h₁ : Surjective ⇑(algebraMap P' S)
h₂ : RingHom.ker (algebraMap P' S) ^ 2 = ⊥
e₁ : (RingHom.ker (algebraMap P S)).Cotangent ≃ₗ[P] ↥(RingHom.ker (algebraMap P' S)) :=
  (RingHom.ker (algebraMap P S)).cotangentEquivIdeal ≪≫ₗ
    LinearEquiv.restrictScalars P
      (LinearEquiv.ofEq (RingHom.ker (IsScalarTower.toAlgHom R P S).toRingHom).cotangentIdeal
        (RingHom.ker (IsScalarTower.toAlgHom R P S).kerSquareLift.toRingHom) ⋯)
e₂ : S ⊗[P'] Ω[P'⁄R] ≃ₗ[P] S ⊗[P] Ω[P⁄R] := LinearEquiv.restrictScalars P (tensorKaehlerQuotKerSqEquiv R P S)
⊢ { l // l ∘ₗ kerCotangentToTensor R P S = LinearMap.id } ≃
    { g // (IsScalarTower.toAlgHom R P S).kerSquareLift.comp g = AlgHom.id R S }