mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.RingTheory.Smooth.Basic

Goal state before:
pp: R : Type u
A : Type v
inst✝⁸ : CommRing R
inst✝⁷ : CommRing A
inst✝⁶ : Algebra R A
B : Type u_1
P✝ : Type u_2
C : Type u_3
inst✝⁵ : CommRing B
inst✝⁴ : Algebra R B
inst✝³ : CommRing C
inst✝² : Algebra R C
inst✝¹ : CommRing P✝
inst✝ : Algebra R P✝
σ : Type u_4
P : Generators R (MvPolynomial σ R) σ := Generators.mvPolynomial R σ
this : Subsingleton ↥P.toExtension.ker
⊢ FormallySmooth R (MvPolynomial σ R)

Tactic:
have : Subsingleton P.toExtension.Cotangent := Cotangent.mk_surjective.subsingleton

Goal state after:
R : Type u
A : Type v
inst✝⁸ : CommRing R
inst✝⁷ : CommRing A
inst✝⁶ : Algebra R A
B : Type u_1
P✝ : Type u_2
C : Type u_3
inst✝⁵ : CommRing B
inst✝⁴ : Algebra R B
inst✝³ : CommRing C
inst✝² : Algebra R C
inst✝¹ : CommRing P✝
inst✝ : Algebra R P✝
σ : Type u_4
P : Generators R (MvPolynomial σ R) σ := Generators.mvPolynomial R σ
this✝ : Subsingleton ↥P.toExtension.ker
this : Subsingleton P.toExtension.Cotangent
⊢ FormallySmooth R (MvPolynomial σ R)
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
p : PrimeSpectrum S
inst✝ : FiniteType R S
H✝² : IsClopen {p}
this✝³ : IsNoetherianRing S
this✝² : IsJacobsonRing S
e : S
he : IsIdempotentElem e
H✝¹ : {p} = ↑(PrimeSpectrum.basicOpen e)
hep : e ∉ p.asIdeal
f : Localization.Away e →ₐ[S] Localization.AtPrime p.asIdeal := IsLocalization.Away.liftAlgHom e ⋯
h₁ : Set.range (PrimeSpectrum.comap (algebraMap S (Localization.Away e))) = {p}
this✝¹ : Subsingleton (PrimeSpectrum (Localization.Away e))
x : S
s : ↥p.asIdeal.primeCompl
H✝ : ¬IsUnit ((algebraMap S (Localization.Away e)) ↑s)
M : Ideal (Localization.Away e)
hM : M.IsMaximal
H : Ideal.span {(algebraMap S (Localization.Away e)) ↑s} ≤ M
this✝ :
  PrimeSpectrum.comap f.toRingHom (IsLocalRing.closedPoint (Localization.AtPrime p.asIdeal)) =
    { asIdeal := M, isPrime := ⋯ }
this :
  (algebraMap S (Localization.Away e)) ↑s ∈
    (PrimeSpectrum.comap f.toRingHom (IsLocalRing.closedPoint (Localization.AtPrime p.asIdeal))).asIdeal
⊢ False

Tactic:
simp [IsLocalRing.closedPoint, IsLocalization.AtPrime.isUnit_to_map_iff _ p.asIdeal] at this

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

Goal state before:
pp: case h2
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
x : (Q.comp P).Ring
hx' : x ∈ (Q.comp P).toExtension.ker
y : (Q.comp P).Ring
hy : y ∈ (Q.comp P).ker * (Q.comp P).ker
e : (Q.ofComp P).toAlgHom x = (Q.ofComp P).toAlgHom y
⊢ Extension.Cotangent.mk ⟨x, hx'⟩ ∈
    (LinearMap.liftBaseChange T (Extension.Cotangent.map (Q.toComp P).toExtensionHom)).range

Tactic:
← sub_eq_zero,

Goal state after:
case h2
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
x : (Q.comp P).Ring
hx' : x ∈ (Q.comp P).toExtension.ker
y : (Q.comp P).Ring
hy : y ∈ (Q.comp P).ker * (Q.comp P).ker
e : (Q.ofComp P).toAlgHom x - (Q.ofComp P).toAlgHom y = 0
⊢ Extension.Cotangent.mk ⟨x, hx'⟩ ∈
    (LinearMap.liftBaseChange T (Extension.Cotangent.map (Q.toComp P).toExtensionHom)).range
Module: Mathlib.RingTheory.Kaehler.JacobiZariski

Goal state before:
pp: 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
Q : Generators S T ι
r : S
⊢ (δAux R Q) (C r) = 1 ⊗ₜ[S] (D R S) r

Tactic:
rw [← monomial_zero', δAux_monomial, Finsupp.prod_zero_index]

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

Goal state before:
pp: 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
ι' : Type w₃
Q : Generators S T ι
Q' : Generators S T ι'
f : Q.Hom Q'
x : Q.Ring
⊢ (δAux R Q') (f.toAlgHom x) =
    (δAux R Q) x +
      (Finsupp.linearCombination T (⇑(δAux R Q') ∘ f.val)) (Q.cotangentSpaceBasis.repr (1 ⊗ₜ[Q.Ring] (D S Q.Ring) x))

Tactic:
let : AddCommGroup (T ⊗[S] Ω[S⁄R]) := inferInstance

Goal state after:
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
ι' : Type w₃
Q : Generators S T ι
Q' : Generators S T ι'
f : Q.Hom Q'
x : Q.Ring
this : AddCommGroup (T ⊗[S] Ω[S⁄R]) := inferInstance
⊢ (δAux R Q') (f.toAlgHom x) =
    (δAux R Q) x +
      (Finsupp.linearCombination T (⇑(δAux R Q') ∘ f.val)) (Q.cotangentSpaceBasis.repr (1 ⊗ₜ[Q.Ring] (D S Q.Ring) x))
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
g✝ : S →ₐ[R] P
f : P →ₐ[R] S
hf' : RingHom.ker f ^ 2 = ⊥
g : S →ₐ[R] P
hg : f.comp g = AlgHom.id R S
a b : P
this : (a - g (f a)) * (b - g (f b)) = 0
| 0

Tactic:
← neg_zero,

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
g✝ : S →ₐ[R] P
f : P →ₐ[R] S
hf' : RingHom.ker f ^ 2 = ⊥
g : S →ₐ[R] P
hg : f.comp g = AlgHom.id R S
a b : P
this : (a - g (f a)) * (b - g (f b)) = 0
| -0
Module: Mathlib.RingTheory.Kaehler.JacobiZariski

Goal state before:
pp: 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
x : (Q.comp P).Ring
⊢ (δAux R Q) ((Q.ofComp P).toAlgHom x) =
    (LinearMap.baseChange T P.toExtension.toKaehler)
      ((CotangentSpace.compEquiv Q P) (1 ⊗ₜ[(Q.comp P).Ring] (D R (Q.comp P).Ring) x)).2

Tactic:
let : AddCommGroup (T ⊗[S] Ω[S⁄R]) := inferInstance

Goal state after:
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
x : (Q.comp P).Ring
this : AddCommGroup (T ⊗[S] Ω[S⁄R]) := inferInstance
⊢ (δAux R Q) ((Q.ofComp P).toAlgHom x) =
    (LinearMap.baseChange T P.toExtension.toKaehler)
      ((CotangentSpace.compEquiv Q P) (1 ⊗ₜ[(Q.comp P).Ring] (D R (Q.comp P).Ring) x)).2
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) * ↑m = p * ↑m

Tactic:
← sub_eq_zero,

Goal state after:
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) * ↑m - p * ↑m = 0
Module: Mathlib.RingTheory.Unramified.Field

Goal state before:
pp: case e_f
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)
f : A ⧸ IsLocalRing.maximalIdeal A →ₗ[A] A := e'.toLinearMap ∘ₗ sec K A (A ⧸ IsLocalRing.maximalIdeal A)
r : A
s : A ⧸ IsLocalRing.maximalIdeal A
⊢ (↑K ((ofId A (A ⧸ IsLocalRing.maximalIdeal A)).toLinearMap ∘ₗ e'.toLinearMap)) (r ⊗ₜ[K] s) =
    (↑K
        (TensorProduct.AlgebraTensorModule.lift
          (↑K (lsmul A A (A ⧸ IsLocalRing.maximalIdeal A)).toLinearMap.flip).flip))
      (r ⊗ₜ[K] s)

Tactic:
obtain ⟨s, rfl⟩ := e.surjective s

Goal state after:
case e_f
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)
f : A ⧸ IsLocalRing.maximalIdeal A →ₗ[A] A := e'.toLinearMap ∘ₗ sec K A (A ⧸ IsLocalRing.maximalIdeal A)
r : A
s : K
⊢ (↑K ((ofId A (A ⧸ IsLocalRing.maximalIdeal A)).toLinearMap ∘ₗ e'.toLinearMap)) (r ⊗ₜ[K] e s) =
    (↑K
        (TensorProduct.AlgebraTensorModule.lift
          (↑K (lsmul A A (A ⧸ IsLocalRing.maximalIdeal A)).toLinearMap.flip).flip))
      (r ⊗ₜ[K] e 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
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)
n : ℕ
hn : IsLocalRing.maximalIdeal A ^ n = 0
this : (1 - f 1) ^ n = 0
⊢ 1 = f 1

Tactic:
← sub_eq_zero,

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
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)
n : ℕ
hn : IsLocalRing.maximalIdeal A ^ n = 0
this : (1 - f 1) ^ n = 0
⊢ 1 - f 1 = 0
Module: Mathlib.RingTheory.Kaehler.JacobiZariski

Goal state before:
pp: 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
ι' : Type w₃
σ : Type w₂
σ' : Type w₄
Q : Generators S T ι
P : Generators R S σ
Q' : Generators S T ι'
P' : Generators R S σ'
f : Q'.Hom Q
x : Q'.toExtension.H1Cotangent
⊢ (δ Q P) ((Extension.H1Cotangent.map f.toExtensionHom) x) = (δ Q' P') x

Tactic:
let : AddCommGroup (T ⊗[S] Ω[S⁄R]) := inferInstance

Goal state after:
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
ι' : Type w₃
σ : Type w₂
σ' : Type w₄
Q : Generators S T ι
P : Generators R S σ
Q' : Generators S T ι'
P' : Generators R S σ'
f : Q'.Hom Q
x : Q'.toExtension.H1Cotangent
this : AddCommGroup (T ⊗[S] Ω[S⁄R]) := inferInstance
⊢ (δ Q P) ((Extension.H1Cotangent.map f.toExtensionHom) x) = (δ Q' P') x
Module: Mathlib.RingTheory.RamificationInertia.Ramification

Goal state before:
pp: case hn0
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
⊢ map (algebraMap S (Localization.AtPrime q)) q < ⊤

Tactic:
Localization.AtPrime.map_eq_maximalIdeal

Goal state after:
case hn0
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
⊢ IsLocalRing.maximalIdeal (Localization q.primeCompl) < ⊤
Module: Mathlib.RingTheory.Etale.Kaehler

Goal state before:
pp: 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✝ : Algebra S T
P : Extension R S
Q : Extension R T
f : P.Hom Q
alg : Algebra P.Ring Q.Ring
halg : algebraMap P.Ring Q.Ring = f.toRingHom
H : Function.Bijective ⇑(LinearMap.liftBaseChange Q.Ring (f.mapKer halg))
x : Q.Ring
y : ↥P.ker
⊢ (tensorCotangentInvFun f halg H) (x • Cotangent.mk ⟨f.toRingHom ↑y, ⋯⟩) = x • 1 ⊗ₜ[S] Cotangent.mk y

Tactic:
let := ((algebraMap S T).comp (algebraMap P.Ring S)).toAlgebra
  have : IsScalarTower P.Ring S T := .of_algebraMap_eq' rfl
  have : IsScalarTower P.Ring Q.Ring T :=
    .of_algebraMap_eq fun r ↦ halg ▸ (f.algebraMap_toRingHom r).symm
  let e := LinearEquiv.ofBijective _ H
  trans tensorCotangentInvFun f halg H (.mk ((f.mapKer halg).liftBaseChange Q.Ring (x ⊗ₜ y)))
  · simp; rfl
  change ((TensorProduct.mk _ _ _ 1).restrictScalars _ ∘ₗ Cotangent.mk).liftBaseChange _
    (e.symm (e (x ⊗ₜ y))) = _
  rw [e.symm_apply_apply]
  simp

Goal state after:
Module: Mathlib.RingTheory.RamificationInertia.Ramification

Goal state before:
pp: S : Type u_1
inst✝⁵ : CommRing S
q : Ideal S
R : Type u_2
inst✝⁴ : CommRing R
inst✝³ : Algebra R S
inst✝² : q.IsPrime
inst✝¹ : Algebra.EssFiniteType R S
inst✝ : Algebra.IsUnramifiedAt R q
p : Ideal R := under R q
Rp : Type u_2 := Localization.AtPrime p
Sq : Type u_1 := Localization.AtPrime q
this✝ : Algebra Rp Sq := Localization.AtPrime.algebraOfLiesOver p q
this : Algebra.EssFiniteType Rp Sq
⊢ map (algebraMap Rp Sq) (map (algebraMap R Rp) (under R q)) = IsLocalRing.maximalIdeal (Localization.AtPrime q)

Tactic:
Localization.AtPrime.map_eq_maximalIdeal

Goal state after:
S : Type u_1
inst✝⁵ : CommRing S
q : Ideal S
R : Type u_2
inst✝⁴ : CommRing R
inst✝³ : Algebra R S
inst✝² : q.IsPrime
inst✝¹ : Algebra.EssFiniteType R S
inst✝ : Algebra.IsUnramifiedAt R q
p : Ideal R := under R q
Rp : Type u_2 := Localization.AtPrime p
Sq : Type u_1 := Localization.AtPrime q
this✝ : Algebra Rp Sq := Localization.AtPrime.algebraOfLiesOver p q
this : Algebra.EssFiniteType Rp Sq
⊢ map (algebraMap Rp Sq) (IsLocalRing.maximalIdeal (Localization p.primeCompl)) =
    IsLocalRing.maximalIdeal (Localization.AtPrime q)
Module: Mathlib.RingTheory.Unramified.LocalRing

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
p : Ideal R
inst✝⁶ : p.IsPrime
q : Ideal S
inst✝⁵ : q.IsPrime
hq : p.primesOver S = {q}
inst✝⁴ : Module.Finite R S
inst✝³ : q.LiesOver p
inst✝² : Algebra.IsUnramifiedAt R q
inst✝¹ : Algebra (Localization.AtPrime p) (Localization.AtPrime q)
inst✝ : AtPrime.IsLiesOverAlgebra p q
H : Function.Surjective ⇑(algebraMap p.ResidueField q.ResidueField)
this : Module.Finite (Localization.AtPrime p) (Localization.AtPrime q)
x : Localization.AtPrime q
a : Localization.AtPrime p
ha :
  (residue (Localization.AtPrime q)) ((algebraMap (Localization.AtPrime p) (Localization.AtPrime q)) a) =
    (residue (Localization.AtPrime q)) x
⊢ x ∈
    (Algebra.linearMap (Localization.AtPrime p) (Localization.AtPrime q)).range ⊔
      Submodule.restrictScalars (Localization.AtPrime p) (maximalIdeal (Localization.AtPrime q))

Tactic:
← sub_eq_zero,

Goal state after:
R : Type u_1
S : Type u_2
inst✝⁹ : CommRing R
inst✝⁸ : CommRing S
inst✝⁷ : Algebra R S
p : Ideal R
inst✝⁶ : p.IsPrime
q : Ideal S
inst✝⁵ : q.IsPrime
hq : p.primesOver S = {q}
inst✝⁴ : Module.Finite R S
inst✝³ : q.LiesOver p
inst✝² : Algebra.IsUnramifiedAt R q
inst✝¹ : Algebra (Localization.AtPrime p) (Localization.AtPrime q)
inst✝ : AtPrime.IsLiesOverAlgebra p q
H : Function.Surjective ⇑(algebraMap p.ResidueField q.ResidueField)
this : Module.Finite (Localization.AtPrime p) (Localization.AtPrime q)
x : Localization.AtPrime q
a : Localization.AtPrime p
ha :
  (residue (Localization.AtPrime q)) ((algebraMap (Localization.AtPrime p) (Localization.AtPrime q)) a) -
      (residue (Localization.AtPrime q)) x =
    0
⊢ x ∈
    (Algebra.linearMap (Localization.AtPrime p) (Localization.AtPrime q)).range ⊔
      Submodule.restrictScalars (Localization.AtPrime p) (maximalIdeal (Localization.AtPrime q))
Module: Mathlib.RingTheory.RamificationInertia.Ramification

Goal state before:
pp: case neg
R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁸ : CommRing R
inst✝⁷ : CommRing S
inst✝⁶ : CommRing T
inst✝⁵ : Algebra R S
inst✝⁴ : Algebra R T
inst✝³ : Algebra S T
inst✝² : IsScalarTower R S T
q : Ideal S
r : Ideal T
inst✝¹ : r.LiesOver q
inst✝ : Module.Flat S T
hr : ¬r.IsPrime
⊢ r.ramificationIdx R = q.ramificationIdx R * r.ramificationIdx S

Tactic:
rw [ramificationIdx_of_not_isPrime r R hr, ramificationIdx_of_not_isPrime r S hr, mul_zero]

Goal state after:
Module: Mathlib.RingTheory.RamificationInertia.Ramification

Goal state before:
pp: case pos
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
p : Ideal R := under R q
f₀ : S ≃ₐ[R] S := (MulSemiringAction.toAlgAut G R S) g
hg : g • q = map f₀ q
Sq : Type u_2 := Localization.AtPrime q
Sq' : Type u_2 := Localization.AtPrime (map f₀ q)
f : Sq ≃ₐ[R] Sq' := Localization.localAlgEquiv q (map f₀ q) f₀ ⋯
⊢ (g • q).ramificationIdx R = q.ramificationIdx R

Tactic:
let : Algebra Sq Sq' := f.toRingHom.toAlgebra

Goal state after:
case pos
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
p : Ideal R := under R q
f₀ : S ≃ₐ[R] S := (MulSemiringAction.toAlgAut G R S) g
hg : g • q = map f₀ q
Sq : Type u_2 := Localization.AtPrime q
Sq' : Type u_2 := Localization.AtPrime (map f₀ q)
f : Sq ≃ₐ[R] Sq' := Localization.localAlgEquiv q (map f₀ q) f₀ ⋯
this : Algebra Sq Sq' := f.toRingEquiv.toRingHom.toAlgebra
⊢ (g • q).ramificationIdx R = q.ramificationIdx R
Module: Mathlib.LinearAlgebra.Countable

Goal state before:
pp: M : Type u_1
R : Type u_2
inst✝⁴ : Semiring R
inst✝³ : AddCommMonoid M
inst✝² : Module R M
inst✝¹ : Countable R
inst✝ : Module.Finite R M
n : ℕ
s : Fin n → M
h : Submodule.span R (Set.range s) = ⊤
⊢ Countable M

Tactic:
← Set.countable_univ_iff

Goal state after:
M : Type u_1
R : Type u_2
inst✝⁴ : Semiring R
inst✝³ : AddCommMonoid M
inst✝² : Module R M
inst✝¹ : Countable R
inst✝ : Module.Finite R M
n : ℕ
s : Fin n → M
h : Submodule.span R (Set.range s) = ⊤
⊢ Set.univ.Countable
Module: Mathlib.Algebra.Module.Torsion.PrimaryComponent

Goal state before:
pp: A : Type u_1
M : Type u_2
inst✝² : CommRing A
inst✝¹ : AddCommMonoid M
inst✝ : Module A M
I : Ideal A
x : M
⊢ x ∈ Submodule.map (torsionBySet A M ↑I).subtype (primaryComponent (↥(torsionBySet A M ↑I)) I) ↔
    x ∈ primaryComponent M I ⊓ torsionBySet A M ↑I

Tactic:
simp [primaryComponent_mem]

Goal state after:
Module: Mathlib.Algebra.Module.Torsion.PrimaryComponent

Goal state before:
pp: A : Type u_1
M : Type u_2
inst✝² : CommRing A
I : Ideal A
inst✝¹ : AddCommMonoid M
inst✝ : Module A M
J : Ideal A
hD : IsCoprime I J
⊢ primaryComponent (↥(torsionBySet A M ↑J)) I = ⊥

Tactic:
have (n : ℕ) : Disjoint (torsionBySet A M ↑(I ^ n)) (torsionBySet A M ↑J) :=
    Submodule.disjoint_torsionBySet_ideal (M := M) (Ideal.pow_sup_eq_top hD.sup_eq)
  apply Submodule.map_injective_of_injective (Submodule.subtype_injective (torsionBySet A M ↑J))
  ext x
  simp only [mem_map, primaryComponent_mem, mem_torsionBySet_iff, SetLike.coe_sort_coe,
    Subtype.forall, subtype_apply, Subtype.exists, SetLike.mk_smul_mk, mk_eq_zero, exists_and_left,
    exists_prop, exists_eq_right_right, Submodule.map_bot, Submodule.mem_bot]
  refine ⟨fun ⟨⟨n, _⟩, _⟩ ↦ ?_, by simp_all⟩
  specialize this n
  simp_all [disjoint_def]

Goal state after:
Module: Mathlib.Algebra.Module.Torsion.PrimaryComponent

Goal state before:
pp: case mp
A : Type u_1
M : Type u_2
inst✝³ : CommRing A
inst✝² : AddCommGroup M
inst✝¹ : Module A M
inst✝ : IsDedekindDomain A
h : IsTorsion A M
x✝ : M
a : A
ha : a ∈ A⁰
hmem : x✝ ∈ torsionBySet A M ↑(⨅ i, i.maxPowDividing (span {a}))
ha0 : span {a} ≠ ⊥
this : Fintype ↑(mulSupport fun v ↦ v.maxPowDividing (span {a})) := ⋯
S : Finset (HeightOneSpectrum A) := ⋯
x : A
⊢ x ∈ ⨅ i, i.maxPowDividing (span {a}) → x ∈ ⨅ i ∈ S, i.maxPowDividing (span {a})

pp: case mpr
A : Type u_1
M : Type u_2
inst✝³ : CommRing A
inst✝² : AddCommGroup M
inst✝¹ : Module A M
inst✝ : IsDedekindDomain A
h : IsTorsion A M
x✝ : M
a : A
ha : a ∈ A⁰
hmem : x✝ ∈ torsionBySet A M ↑(⨅ i, i.maxPowDividing (span {a}))
ha0 : span {a} ≠ ⊥
this : Fintype ↑(mulSupport fun v ↦ v.maxPowDividing (span {a})) := ⋯
S : Finset (HeightOneSpectrum A) := ⋯
x : A
⊢ x ∈ ⨅ i ∈ S, i.maxPowDividing (span {a}) → x ∈ ⨅ i, i.maxPowDividing (span {a})

Tactic:
· aesop

Goal state after:
case mpr
A : Type u_1
M : Type u_2
inst✝³ : CommRing A
inst✝² : AddCommGroup M
inst✝¹ : Module A M
inst✝ : IsDedekindDomain A
h : IsTorsion A M
x✝ : M
a : A
ha : a ∈ A⁰
hmem : x✝ ∈ torsionBySet A M ↑(⨅ i, i.maxPowDividing (span {a}))
ha0 : span {a} ≠ ⊥
this : Fintype ↑(mulSupport fun v ↦ v.maxPowDividing (span {a})) := ⋯
S : Finset (HeightOneSpectrum A) := ⋯
x : A
⊢ x ∈ ⨅ i ∈ S, i.maxPowDividing (span {a}) → x ∈ ⨅ i, i.maxPowDividing (span {a})