mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.RingTheory.Ideal.Norm.AbsNorm

Goal state before:
pp: S : Type u_1
inst✝¹ : CommRing S
P : Ideal S
P_prime : P.IsPrime
inst✝ : IsDedekindDomain S
hP : P ≠ ⊥
i : ℕ
a c : S
a_mem : a ∈ P ^ i
c_mem : c ∈ P ^ i
this : P ^ (i + 1) = span {a} ⊔ P ^ (i + 1)
⊢ a ∈ P ^ (i + 1)

Tactic:
rw [this]

Goal state after:
S : Type u_1
inst✝¹ : CommRing S
P : Ideal S
P_prime : P.IsPrime
inst✝ : IsDedekindDomain S
hP : P ≠ ⊥
i : ℕ
a c : S
a_mem : a ∈ P ^ i
c_mem : c ∈ P ^ i
this : P ^ (i + 1) = span {a} ⊔ P ^ (i + 1)
⊢ a ∈ span {a} ⊔ P ^ (i + 1)
Module: Mathlib.RingTheory.Spectrum.Prime.Noetherian

Goal state before:
pp: case refine_3
R : Type u_1
inst✝² : CommRing R
inst✝¹ : IsArtinianRing R
p : Ideal R
inst✝ : p.IsPrime
r : R
hr : (toPiLocalization R) r = Pi.single { asIdeal := p, isPrime := ⋯ } 1
this : (algebraMap R (Localization p.primeCompl)) r = 1
⊢ ∀ (q : Ideal R), q.IsPrime → q ≠ p → r ∈ q

Tactic:
intro q

Goal state after:
case refine_3
R : Type u_1
inst✝² : CommRing R
inst✝¹ : IsArtinianRing R
p : Ideal R
inst✝ : p.IsPrime
r : R
hr : (toPiLocalization R) r = Pi.single { asIdeal := p, isPrime := ⋯ } 1
this : (algebraMap R (Localization p.primeCompl)) r = 1
q : Ideal R
⊢ q.IsPrime → q ≠ p → r ∈ q
Module: Mathlib.RingTheory.Ideal.Norm.AbsNorm

Goal state before:
pp: S : Type u_1
inst✝² : CommRing S
inst✝¹ : IsDedekindDomain S
inst✝ : Free ℤ S
I : Ideal S
⊢ ↑(absNorm I) ∈ I

Tactic:
by
  rw [absNorm_apply, cardQuot, ← Ideal.Quotient.eq_zero_iff_mem, map_natCast,
    Quotient.index_eq_zero]

Goal state after:
Module: Mathlib.GroupTheory.Submonoid.Inverses

Goal state before:
pp: M : Type u_1
inst✝ : Monoid M
S : Submonoid M
hS : S ≤ IsUnit.submonoid M
x : M
hx : x ∈ S
this : x = ↑(IsUnit.unit ⋯)⁻¹⁻¹
⊢ x ∈ S.leftInv.leftInv

Tactic:
rw [this]

Goal state after:
M : Type u_1
inst✝ : Monoid M
S : Submonoid M
hS : S ≤ IsUnit.submonoid M
x : M
hx : x ∈ S
this : x = ↑(IsUnit.unit ⋯)⁻¹⁻¹
⊢ ↑(IsUnit.unit ⋯)⁻¹⁻¹ ∈ S.leftInv.leftInv
Module: Mathlib.RingTheory.Spectrum.Prime.Jacobson

Goal state before:
pp: R : Type u_1
inst✝¹ : CommRing R
inst✝ : IsJacobsonRing R
s : Set (PrimeSpectrum R)
hs : IsOpen s
hs' : s.Nonempty
I : Ideal R
hI' : sᶜ = zeroLocus ↑I
this : ∀ (x : PrimeSpectrum R), ¬↑I ⊆ ↑x.asIdeal → ¬x.asIdeal.IsMaximal
⊢ s = ∅

Tactic:
simp_rw [not_imp_not] at this

Goal state after:
R : Type u_1
inst✝¹ : CommRing R
inst✝ : IsJacobsonRing R
s : Set (PrimeSpectrum R)
hs : IsOpen s
hs' : s.Nonempty
I : Ideal R
hI' : sᶜ = zeroLocus ↑I
this : ∀ (x : PrimeSpectrum R), x.asIdeal.IsMaximal → ↑I ⊆ ↑x.asIdeal
⊢ s = ∅
Module: Mathlib.RingTheory.Spectrum.Prime.Jacobson

Goal state before:
pp: R : Type u_1
inst✝ : CommRing R
H : JacobsonSpace (PrimeSpectrum R)
I : Ideal R
hI : I.IsRadical
⊢ I.jacobson ≤ I

Tactic:
rw [← I.isRadical_jacobson.radical]

Goal state after:
R : Type u_1
inst✝ : CommRing R
H : JacobsonSpace (PrimeSpectrum R)
I : Ideal R
hI : I.IsRadical
⊢ I.jacobson.radical ≤ I
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: case e'_2.e'_6
R : Type u
inst✝⁴ : CommRing R
S : Type v
inst✝³ : CommRing S
inst✝² : Algebra R S
inst✝¹ : IsDedekindDomain S
p : Ideal R
P : Ideal S
inst✝ : P.IsPrime
hp : P ≠ ⊥
hpP : map f p ≤ P
Sₚ : Type v := Localization.AtPrime P
H₁ : ¬map f p ≤ P * P
a : Ideal S
ha : map f p = P * a
ha' : ¬a ≤ P
⊢ ¬Disjoint ↑P.primeCompl ↑a

Tactic:
simpa [primeCompl, Set.disjoint_compl_left_iff_subset]

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

Goal state before:
pp: R : Type u_1
inst✝⁸ : CommRing R
A : Type u_2
inst✝⁷ : CommRing A
inst✝⁶ : Algebra R A
B : Type u_3
inst✝⁵ : CommRing B
inst✝⁴ : Algebra R B
inst✝³ : Algebra A B
inst✝² : IsScalarTower R A B
inst✝¹ : FormallyUnramified R A
inst✝ : FormallyUnramified A B
⊢ ∀ ⦃B_1 : Type u_3⦄ [inst : CommRing B_1] [inst_1 : Algebra R B_1] (I : Ideal B_1),
    I ^ 2 = ⊥ → Function.Injective (Ideal.Quotient.mkₐ R I).comp

Tactic:
intro C _ _ I hI f₁ f₂ e

Goal state after:
R : Type u_1
inst✝¹⁰ : CommRing R
A : Type u_2
inst✝⁹ : CommRing A
inst✝⁸ : Algebra R A
B : Type u_3
inst✝⁷ : CommRing B
inst✝⁶ : Algebra R B
inst✝⁵ : Algebra A B
inst✝⁴ : IsScalarTower R A B
inst✝³ : FormallyUnramified R A
inst✝² : FormallyUnramified A B
C : Type u_3
inst✝¹ : CommRing C
inst✝ : Algebra R C
I : Ideal C
hI : I ^ 2 = ⊥
f₁ f₂ : B →ₐ[R] C
e : (Ideal.Quotient.mkₐ R I).comp f₁ = (Ideal.Quotient.mkₐ R I).comp f₂
⊢ f₁ = f₂
Module: Mathlib.RingTheory.Unramified.Basic

Goal state before:
pp: R : Type u_1
inst✝⁵ : CommRing R
A : Type u_2
inst✝⁴ : CommRing A
inst✝³ : Algebra R A
B : Type u_3
inst✝² : CommRing B
inst✝¹ : Algebra R B
inst✝ : FormallyUnramified R A
⊢ ∀ ⦃B_1 : Type (max u_2 u_3)⦄ [inst : CommRing B_1] [inst_1 : Algebra B B_1] (I : Ideal B_1),
    I ^ 2 = ⊥ → Function.Injective (Ideal.Quotient.mkₐ B I).comp

Tactic:
intro C _ _ I hI f₁ f₂ e

Goal state after:
R : Type u_1
inst✝⁷ : CommRing R
A : Type u_2
inst✝⁶ : CommRing A
inst✝⁵ : Algebra R A
B : Type u_3
inst✝⁴ : CommRing B
inst✝³ : Algebra R B
inst✝² : FormallyUnramified R A
C : Type (max u_2 u_3)
inst✝¹ : CommRing C
inst✝ : Algebra B C
I : Ideal C
hI : I ^ 2 = ⊥
f₁ f₂ : B ⊗[R] A →ₐ[B] C
e : (Ideal.Quotient.mkₐ B I).comp f₁ = (Ideal.Quotient.mkₐ B I).comp f₂
⊢ f₁ = f₂
Module: Mathlib.RingTheory.Unramified.Finite

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝⁸ : CommRing R
inst✝⁷ : CommRing S
inst✝⁶ : Algebra R S
M : Type u_3
inst✝⁵ : AddCommGroup M
inst✝⁴ : Module R M
inst✝³ : Module S M
inst✝² : IsScalarTower R S M
inst✝¹ : FormallyUnramified R S
inst✝ : EssFiniteType R S
r : S
m : M
this : 1 ⊗ₜ[R] r * elem R S = r ⊗ₜ[R] 1 * elem R S
⊢ (TensorProduct.AlgebraTensorModule.map LinearMap.id ((lsmul R R M).toLinearMap.flip m)) (1 ⊗ₜ[R] r * elem R S) =
    r • (TensorProduct.AlgebraTensorModule.map LinearMap.id ((lsmul R R M).toLinearMap.flip m)) (elem R S)

Tactic:
rw [this]

Goal state after:
R : Type u_1
S : Type u_2
inst✝⁸ : CommRing R
inst✝⁷ : CommRing S
inst✝⁶ : Algebra R S
M : Type u_3
inst✝⁵ : AddCommGroup M
inst✝⁴ : Module R M
inst✝³ : Module S M
inst✝² : IsScalarTower R S M
inst✝¹ : FormallyUnramified R S
inst✝ : EssFiniteType R S
r : S
m : M
this : 1 ⊗ₜ[R] r * elem R S = r ⊗ₜ[R] 1 * elem R S
⊢ (TensorProduct.AlgebraTensorModule.map LinearMap.id ((lsmul R R M).toLinearMap.flip m)) (r ⊗ₜ[R] 1 * elem R S) =
    r • (TensorProduct.AlgebraTensorModule.map LinearMap.id ((lsmul R R M).toLinearMap.flip m)) (elem R S)
Module: Mathlib.RingTheory.Smooth.Basic

Goal state before:
pp: R : Type u
A : Type v
inst✝² : CommRing R
inst✝¹ : CommRing A
inst✝ : Algebra R A
H :
  ∀ ⦃B : Type (max u v)⦄ [inst : CommRing B] [inst_1 : Algebra R B] (I : Ideal B),
    I ^ 2 = ⊥ → Function.Surjective (Ideal.Quotient.mkₐ R I).comp
P : Generators R A A := Generators.self R A
f : P.Ring →ₐ[R] A := IsScalarTower.toAlgHom R P.Ring A
surj : Function.Surjective ⇑f.kerSquareLift
sqz : RingHom.ker f.kerSquareLift ^ 2 = ⊥
g : A →ₐ[R] P.Ring ⧸ RingHom.ker f ^ 2
hg : (Ideal.Quotient.mkₐ R (RingHom.ker f.kerSquareLift)).comp g = ↑(Ideal.quotientKerAlgEquivOfSurjective surj).symm
x : P.Ring ⧸ RingHom.ker f.toRingHom ^ 2
⊢ f.kerSquareLift.kerLift
      (↑(Ideal.quotientKerAlgEquivOfSurjective surj).symm
        ((Ideal.quotientKerAlgEquivOfSurjective surj) ((Ideal.Quotient.mk (RingHom.ker f.kerSquareLift)) x))) =
    (AlgHom.id R A) ((Ideal.quotientKerAlgEquivOfSurjective surj) ((Ideal.Quotient.mk (RingHom.ker f.kerSquareLift)) x))

Tactic:
simp only [AlgHom.toRingHom_eq_coe, AlgEquiv.coe_toAlgHom, AlgEquiv.symm_apply_apply,
    AlgHom.coe_id, id_eq]

Goal state after:
R : Type u
A : Type v
inst✝² : CommRing R
inst✝¹ : CommRing A
inst✝ : Algebra R A
H :
  ∀ ⦃B : Type (max u v)⦄ [inst : CommRing B] [inst_1 : Algebra R B] (I : Ideal B),
    I ^ 2 = ⊥ → Function.Surjective (Ideal.Quotient.mkₐ R I).comp
P : Generators R A A := Generators.self R A
f : P.Ring →ₐ[R] A := IsScalarTower.toAlgHom R P.Ring A
surj : Function.Surjective ⇑f.kerSquareLift
sqz : RingHom.ker f.kerSquareLift ^ 2 = ⊥
g : A →ₐ[R] P.Ring ⧸ RingHom.ker f ^ 2
hg : (Ideal.Quotient.mkₐ R (RingHom.ker f.kerSquareLift)).comp g = ↑(Ideal.quotientKerAlgEquivOfSurjective surj).symm
x : P.Ring ⧸ RingHom.ker f.toRingHom ^ 2
⊢ (↑f.kerSquareLift).kerLift ((Ideal.Quotient.mk (RingHom.ker f.kerSquareLift)) x) =
    (Ideal.quotientKerAlgEquivOfSurjective surj) ((Ideal.Quotient.mk (RingHom.ker f.kerSquareLift)) x)
Module: Mathlib.RingTheory.Smooth.Basic

Goal state before:
pp: R : Type u_4
inst✝⁸ : CommRing R
A : Type u_5
inst✝⁷ : CommRing A
inst✝⁶ : Algebra R A
B : Type u_6
inst✝⁵ : CommRing B
inst✝⁴ : Algebra R B
inst✝³ : Algebra A B
inst✝² : IsScalarTower R A B
inst✝¹ : FormallySmooth R A
inst✝ : FormallySmooth A B
C : Type (max u_4 u_6)
x✝¹ : CommRing C
x✝ : Algebra R C
I : Ideal C
hI : I ^ 2 = ⊥
f : B →ₐ[R] C ⧸ I
f' : A →ₐ[R] C
e : (Ideal.Quotient.mkₐ R I).comp f' = f.comp (IsScalarTower.toAlgHom R A B)
⊢ ∃ a, (Ideal.Quotient.mkₐ R I).comp a = f

Tactic:
let := f'.toRingHom.toAlgebra

Goal state after:
R : Type u_4
inst✝⁸ : CommRing R
A : Type u_5
inst✝⁷ : CommRing A
inst✝⁶ : Algebra R A
B : Type u_6
inst✝⁵ : CommRing B
inst✝⁴ : Algebra R B
inst✝³ : Algebra A B
inst✝² : IsScalarTower R A B
inst✝¹ : FormallySmooth R A
inst✝ : FormallySmooth A B
C : Type (max u_4 u_6)
x✝¹ : CommRing C
x✝ : Algebra R C
I : Ideal C
hI : I ^ 2 = ⊥
f : B →ₐ[R] C ⧸ I
f' : A →ₐ[R] C
e : (Ideal.Quotient.mkₐ R I).comp f' = f.comp (IsScalarTower.toAlgHom R A B)
this : Algebra A C := f'.toAlgebra
⊢ ∃ a, (Ideal.Quotient.mkₐ R I).comp a = f
Module: Mathlib.RingTheory.Smooth.Basic

Goal state before:
pp: R✝ : Type u
A✝ : Type v
inst✝¹⁴ : CommRing R✝
inst✝¹³ : CommRing A✝
inst✝¹² : Algebra R✝ A✝
B✝ : Type u_1
P : Type u_2
C✝ : Type u_3
inst✝¹¹ : CommRing B✝
inst✝¹⁰ : Algebra R✝ B✝
inst✝⁹ : CommRing C✝
inst✝⁸ : Algebra R✝ C✝
inst✝⁷ : CommRing P
inst✝⁶ : Algebra R✝ P
R : Type u_4
inst✝⁵ : CommRing R
A : Type u_5
inst✝⁴ : CommRing A
inst✝³ : Algebra R A
B : Type u_6
inst✝² : CommRing B
inst✝¹ : Algebra R B
inst✝ : FormallySmooth R A
C : Type (max u_5 u_6)
x✝¹ : CommRing C
x✝ : Algebra B C
I : Ideal C
hI : I ^ 2 = ⊥
f : B ⊗[R] A →ₐ[B] C ⧸ I
this✝ : Algebra R C := ((algebraMap B C).comp (algebraMap R B)).toAlgebra
this : IsScalarTower R B C
⊢ ∃ a, (Ideal.Quotient.mkₐ B I).comp a = f

Tactic:
refine ⟨TensorProduct.productLeftAlgHom (Algebra.ofId B C) ?_, ?_⟩

Goal state after:
case refine_1
R✝ : Type u
A✝ : Type v
inst✝¹⁴ : CommRing R✝
inst✝¹³ : CommRing A✝
inst✝¹² : Algebra R✝ A✝
B✝ : Type u_1
P : Type u_2
C✝ : Type u_3
inst✝¹¹ : CommRing B✝
inst✝¹⁰ : Algebra R✝ B✝
inst✝⁹ : CommRing C✝
inst✝⁸ : Algebra R✝ C✝
inst✝⁷ : CommRing P
inst✝⁶ : Algebra R✝ P
R : Type u_4
inst✝⁵ : CommRing R
A : Type u_5
inst✝⁴ : CommRing A
inst✝³ : Algebra R A
B : Type u_6
inst✝² : CommRing B
inst✝¹ : Algebra R B
inst✝ : FormallySmooth R A
C : Type (max u_5 u_6)
x✝¹ : CommRing C
x✝ : Algebra B C
I : Ideal C
hI : I ^ 2 = ⊥
f : B ⊗[R] A →ₐ[B] C ⧸ I
this✝ : Algebra R C := ((algebraMap B C).comp (algebraMap R B)).toAlgebra
this : IsScalarTower R B C
⊢ A →ₐ[R] C

case refine_2
R✝ : Type u
A✝ : Type v
inst✝¹⁴ : CommRing R✝
inst✝¹³ : CommRing A✝
inst✝¹² : Algebra R✝ A✝
B✝ : Type u_1
P : Type u_2
C✝ : Type u_3
inst✝¹¹ : CommRing B✝
inst✝¹⁰ : Algebra R✝ B✝
inst✝⁹ : CommRing C✝
inst✝⁸ : Algebra R✝ C✝
inst✝⁷ : CommRing P
inst✝⁶ : Algebra R✝ P
R : Type u_4
inst✝⁵ : CommRing R
A : Type u_5
inst✝⁴ : CommRing A
inst✝³ : Algebra R A
B : Type u_6
inst✝² : CommRing B
inst✝¹ : Algebra R B
inst✝ : FormallySmooth R A
C : Type (max u_5 u_6)
x✝¹ : CommRing C
x✝ : Algebra B C
I : Ideal C
hI : I ^ 2 = ⊥
f : B ⊗[R] A →ₐ[B] C ⧸ I
this✝ : Algebra R C := ((algebraMap B C).comp (algebraMap R B)).toAlgebra
this : IsScalarTower R B C
⊢ (Ideal.Quotient.mkₐ B I).comp (TensorProduct.productLeftAlgHom (ofId B C) ?refine_1) = f
Module: Mathlib.RingTheory.Smooth.Basic

Goal state before:
pp: R : Type u_4
Rₘ : Type u_6
Sₘ : Type u_7
inst✝⁸ : CommRing R
inst✝⁷ : CommRing Rₘ
inst✝⁶ : CommRing Sₘ
M : Submonoid R
inst✝⁵ : Algebra R Sₘ
inst✝⁴ : Algebra R Rₘ
inst✝³ : Algebra Rₘ Sₘ
inst✝² : IsScalarTower R Rₘ Sₘ
inst✝¹ : IsLocalization M Rₘ
inst✝ : FormallySmooth R Sₘ
Q : Type (max u_6 u_7)
x✝¹ : CommRing Q
x✝ : Algebra Rₘ Q
I : Ideal Q
e : I ^ 2 = ⊥
f : Sₘ →ₐ[Rₘ] Q ⧸ I
this✝ : Algebra R Q := ((algebraMap Rₘ Q).comp (algebraMap R Rₘ)).toAlgebra
this : IsScalarTower R Rₘ Q := IsScalarTower.of_algebraMap_eq' rfl
⊢ Sₘ →ₐ[Rₘ] Q

Tactic:
refine { FormallySmooth.lift I ⟨2, e⟩ (f.restrictScalars R) with commutes' := ?_ }
    intro r
    change
      (RingHom.comp (FormallySmooth.lift I ⟨2, e⟩ (f.restrictScalars R) : Sₘ →+* Q)
            (algebraMap _ _))
          r =
        algebraMap _ _ r
    congr 1
    refine IsLocalization.ringHom_ext M ?_
    rw [RingHom.comp_assoc, ← IsScalarTower.algebraMap_eq, ← IsScalarTower.algebraMap_eq,
      AlgHom.comp_algebraMap]

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 = ⊥
⊢ { l // l ∘ₗ kerCotangentToTensor R P S = LinearMap.id } ≃
    { g // (IsScalarTower.toAlgHom R P S).kerSquareLift.comp g = AlgHom.id R S }

Tactic:
let e₁ : (RingHom.ker (algebraMap P S)).Cotangent ≃ₗ[P] (RingHom.ker (algebraMap P' S)) :=
    (Ideal.cotangentEquivIdeal _).trans ((LinearEquiv.ofEq _ _
      (IsScalarTower.toAlgHom R P S).ker_kerSquareLift.symm).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) ⋯)
⊢ { l // l ∘ₗ kerCotangentToTensor R P S = LinearMap.id } ≃
    { g // (IsScalarTower.toAlgHom R P S).kerSquareLift.comp g = AlgHom.id R S }
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✝¹ : 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)
f : A ⧸ IsLocalRing.maximalIdeal A →ₗ[A] A := e'.toLinearMap ∘ₗ sec K A (A ⧸ IsLocalRing.maximalIdeal A)
hf : (ofId A (A ⧸ IsLocalRing.maximalIdeal A)).toLinearMap ∘ₗ f = LinearMap.id
hf₁ : f 1 • 1 = 1
hf₂ : 1 - f 1 ∈ IsLocalRing.maximalIdeal A
hf₃ : IsIdempotentElem (1 - f 1)
hf₄ : f 1 = 1
x : A
this : ⇑(algebraMap K A) = ⇑f ∘ ⇑e
⊢ (algebraMap K A) ((⇑e.symm ∘ ⇑(algebraMap A (A ⧸ IsLocalRing.maximalIdeal A))) x) = x

Tactic:
rw [this]

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✝¹ : 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)
f : A ⧸ IsLocalRing.maximalIdeal A →ₗ[A] A := e'.toLinearMap ∘ₗ sec K A (A ⧸ IsLocalRing.maximalIdeal A)
hf : (ofId A (A ⧸ IsLocalRing.maximalIdeal A)).toLinearMap ∘ₗ f = LinearMap.id
hf₁ : f 1 • 1 = 1
hf₂ : 1 - f 1 ∈ IsLocalRing.maximalIdeal A
hf₃ : IsIdempotentElem (1 - f 1)
hf₄ : f 1 = 1
x : A
this : ⇑(algebraMap K A) = ⇑f ∘ ⇑e
⊢ (⇑f ∘ ⇑e) ((⇑e.symm ∘ ⇑(algebraMap A (A ⧸ IsLocalRing.maximalIdeal A))) x) = x
Module: Mathlib.RingTheory.Unramified.Field

Goal state before:
pp: K : Type u_1
A : Type u_2
inst✝⁴ : Field K
inst✝³ : CommRing A
inst✝² : Algebra K A
inst✝¹ : FormallyUnramified K A
inst✝ : EssFiniteType K A
x : A
hx : IsNilpotent x
f : A →ₐ[K] AlgebraicClosure K ⊗[K] A := TensorProduct.includeRight
this : ⇑f = ⇑(LinearMap.rTensor A (ofId K (AlgebraicClosure K)).toLinearMap ∘ₗ (TensorProduct.lid K A).symm.toLinearMap)
⊢ Function.Injective ⇑f

Tactic:
rw [this]

Goal state after:
K : Type u_1
A : Type u_2
inst✝⁴ : Field K
inst✝³ : CommRing A
inst✝² : Algebra K A
inst✝¹ : FormallyUnramified K A
inst✝ : EssFiniteType K A
x : A
hx : IsNilpotent x
f : A →ₐ[K] AlgebraicClosure K ⊗[K] A := TensorProduct.includeRight
this : ⇑f = ⇑(LinearMap.rTensor A (ofId K (AlgebraicClosure K)).toLinearMap ∘ₗ (TensorProduct.lid K A).symm.toLinearMap)
⊢ Function.Injective
    ⇑(LinearMap.rTensor A (ofId K (AlgebraicClosure K)).toLinearMap ∘ₗ (TensorProduct.lid K A).symm.toLinearMap)
Module: Mathlib.RingTheory.Unramified.Field

Goal state before:
pp: K : Type u_1
A : Type u_2
inst✝⁴ : Field K
inst✝³ : CommRing A
inst✝² : Algebra K A
inst✝¹ : FormallyUnramified K A
inst✝ : EssFiniteType K A
x : A
hx : IsNilpotent x
f : A →ₐ[K] AlgebraicClosure K ⊗[K] A := TensorProduct.includeRight
this : Function.Injective ⇑f
⊢ f x = 0

Tactic:
apply eq_zero_of_localization

Goal state after:
K : Type u_1
A : Type u_2
inst✝⁴ : Field K
inst✝³ : CommRing A
inst✝² : Algebra K A
inst✝¹ : FormallyUnramified K A
inst✝ : EssFiniteType K A
x : A
hx : IsNilpotent x
f : A →ₐ[K] AlgebraicClosure K ⊗[K] A := ⋯
this : Function.Injective ⇑f
⊢ ∀ (J : Ideal (AlgebraicClosure K ⊗[K] A)) (x_1 : J.IsMaximal),
    (algebraMap (AlgebraicClosure K ⊗[K] A) (Localization.AtPrime J)) (f x) = 0
Module: Mathlib.RingTheory.Smooth.Kaehler

Goal state before:
pp: R : Type u_1
S : Type u_3
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
P : Extension R S
this : CotangentSpace.map P.toInfinitesimal = ↑(tensorKaehlerQuotKerSqEquiv R P.Ring S).symm
⊢ Function.Bijective ⇑(CotangentSpace.map P.toInfinitesimal)

Tactic:
rw [this]

Goal state after:
R : Type u_1
S : Type u_3
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
P : Extension R S
this : CotangentSpace.map P.toInfinitesimal = ↑(tensorKaehlerQuotKerSqEquiv R P.Ring S).symm
⊢ Function.Bijective ⇑↑(tensorKaehlerQuotKerSqEquiv R P.Ring S).symm
Module: Mathlib.RingTheory.RamificationInertia.Ramification

Goal state before:
pp: case hxt
S : Type u_1
inst✝⁴ : CommRing S
q : Ideal S
R : Type u_2
inst✝³ : CommRing R
inst✝² : Algebra R S
inst✝¹ : q.IsPrime
inst✝ : Module.Finite R S
p : Ideal R := under R q
Sq : Type u_1 := Localization.AtPrime q
r : PrimeSpectrum (p.Fiber S) := (PrimeSpectrum.primesOverOrderIsoFiber R S p) (primesOver.mk p q)
this : q = comap Algebra.TensorProduct.includeRight r.asIdeal
⊢ Module.length (Localization.AtPrime q)
      (Localization.AtPrime q ⧸ map (algebraMap R (Localization.AtPrime q)) (under R q)) ≠
    ⊤

Tactic:
let := Localization.AtPrime.algebraOfLiesOver p (r.1.comap Algebra.TensorProduct.includeRight)

Goal state after:
case hxt
S : Type u_1
inst✝⁴ : CommRing S
q : Ideal S
R : Type u_2
inst✝³ : CommRing R
inst✝² : Algebra R S
inst✝¹ : q.IsPrime
inst✝ : Module.Finite R S
p : Ideal R := under R q
Sq : Type u_1 := Localization.AtPrime q
r : PrimeSpectrum (p.Fiber S) := (PrimeSpectrum.primesOverOrderIsoFiber R S p) (primesOver.mk p q)
this✝ : q = comap Algebra.TensorProduct.includeRight r.asIdeal
this : Algebra (Localization.AtPrime p) (Localization.AtPrime (comap Algebra.TensorProduct.includeRight r.asIdeal)) :=
  Localization.AtPrime.algebraOfLiesOver p (comap Algebra.TensorProduct.includeRight r.asIdeal)
⊢ Module.length (Localization.AtPrime q)
      (Localization.AtPrime q ⧸ map (algebraMap R (Localization.AtPrime q)) (under R q)) ≠
    ⊤
Module: Mathlib.RingTheory.RamificationInertia.Basic

Goal state before:
pp: R : Type u_1
inst✝⁵ : CommRing R
p : Ideal R
inst✝⁴ : p.IsPrime
S : Type u_2
inst✝³ : CommRing S
inst✝² : Algebra R S
inst✝¹ : Algebra.QuasiFinite R S
inst✝ : Fintype ↑(p.primesOver S)
this : Fintype (PrimeSpectrum (p.Fiber S)) := ⋯
⊢ ∀ x ∈ Finset.univ,
    (↑((primesOverOrderIsoFiber R S p).symm.toEquiv x)).ramificationIdx R *
        (↑((primesOverOrderIsoFiber R S p).symm.toEquiv x)).inertiaDeg R =
      finrank p.ResidueField (Localization.AtPrime x.asIdeal)

Tactic:
intro q

Goal state after:
R : Type u_1
inst✝⁵ : CommRing R
p : Ideal R
inst✝⁴ : p.IsPrime
S : Type u_2
inst✝³ : CommRing S
inst✝² : Algebra R S
inst✝¹ : Algebra.QuasiFinite R S
inst✝ : Fintype ↑(p.primesOver S)
this : Fintype (PrimeSpectrum (p.Fiber S)) := Fintype.ofFinite (PrimeSpectrum (p.Fiber S))
q : PrimeSpectrum (p.Fiber S)
⊢ q ∈ Finset.univ →
    (↑((primesOverOrderIsoFiber R S p).symm.toEquiv q)).ramificationIdx R *
        (↑((primesOverOrderIsoFiber R S p).symm.toEquiv q)).inertiaDeg R =
      finrank p.ResidueField (Localization.AtPrime q.asIdeal)
Module: Mathlib.RingTheory.RamificationInertia.Ramification

Goal state before:
pp: case neg
R : Type u_1
S : Type u_2
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : Algebra R S
q : Ideal S
G : Type u_4
inst✝² : Group G
inst✝¹ : MulSemiringAction G S
inst✝ : SMulCommClass G R S
g : G
hq : ¬q.IsPrime
⊢ (g • q).ramificationIdx R = q.ramificationIdx R

Tactic:
rw [ramificationIdx_of_not_isPrime, ramificationIdx_of_not_isPrime]

Goal state after:
case neg.hq
R : Type u_1
S : Type u_2
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : Algebra R S
q : Ideal S
G : Type u_4
inst✝² : Group G
inst✝¹ : MulSemiringAction G S
inst✝ : SMulCommClass G R S
g : G
hq : ¬q.IsPrime
⊢ ¬q.IsPrime

case neg.hq
R : Type u_1
S : Type u_2
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : Algebra R S
q : Ideal S
G : Type u_4
inst✝² : Group G
inst✝¹ : MulSemiringAction G S
inst✝ : SMulCommClass G R S
g : G
hq : ¬q.IsPrime
⊢ ¬(g • q).IsPrime
Module: Mathlib.RingTheory.Unramified.LocalRing

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 : Ideal R
inst✝² : p.IsPrime
q : Ideal S
inst✝¹ : q.IsPrime
inst✝ : q.LiesOver p
H✝ : Function.Injective ⇑(localRingHom p q (algebraMap R S) ⋯)
s✝ : Finset R
hs : Ideal.span ↑s✝ = RingHom.ker (algebraMap R S)
this : ∀ (x : ↥s✝), (algebraMap R (Localization.AtPrime p)) ↑x = 0
m : ↥s✝ → ↥p.primeCompl
hm : ∀ (x : ↥s✝), ↑(m x) * ↑x = 0
H : RingHom.ker (algebraMap R S) ≤ RingHom.ker (algebraMap R (Away ↑(∏ i, m i)))
r' s : R
e : r' = ↑(∏ i, m i) * s
x : R
w✝ : ↥(Submonoid.powers r')
n : ℕ
hn : (algebraMap R S) (r' ^ n * x) = 0
k : ℕ
hk : ↑(∏ i, m i) ^ k * (r' ^ n * x) = 0
⊢ r' ^ (k + n) * x = 0

Tactic:
pow_add,

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 : Ideal R
inst✝² : p.IsPrime
q : Ideal S
inst✝¹ : q.IsPrime
inst✝ : q.LiesOver p
H✝ : Function.Injective ⇑(localRingHom p q (algebraMap R S) ⋯)
s✝ : Finset R
hs : Ideal.span ↑s✝ = RingHom.ker (algebraMap R S)
this : ∀ (x : ↥s✝), (algebraMap R (Localization.AtPrime p)) ↑x = 0
m : ↥s✝ → ↥p.primeCompl
hm : ∀ (x : ↥s✝), ↑(m x) * ↑x = 0
H : RingHom.ker (algebraMap R S) ≤ RingHom.ker (algebraMap R (Away ↑(∏ i, m i)))
r' s : R
e : r' = ↑(∏ i, m i) * s
x : R
w✝ : ↥(Submonoid.powers r')
n : ℕ
hn : (algebraMap R S) (r' ^ n * x) = 0
k : ℕ
hk : ↑(∏ i, m i) ^ k * (r' ^ n * x) = 0
⊢ r' ^ k * r' ^ n * x = 0