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

Goal state before:
pp: case e'_2
R : Type u_1
A : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
inst✝ : EssFiniteType R A
p : PrimeSpectrum A
⊢ Module.Projective (Localization.AtPrime p.asIdeal) Ω[Localization.AtPrime p.asIdeal⁄R] ↔
    Module.Free (Localization.AtPrime p.asIdeal) (LocalizedModule p.asIdeal.primeCompl Ω[A⁄R])

Tactic:
trans Module.Free (Localization.AtPrime p.asIdeal) Ω[Localization.AtPrime p.asIdeal⁄R]
    · have : EssFiniteType A (Localization.AtPrime p.asIdeal) :=
        .of_isLocalization _ p.asIdeal.primeCompl
      have : EssFiniteType R (Localization.AtPrime p.asIdeal) := .comp _ A _
      exact ⟨fun _ ↦ Module.free_of_flat_of_isLocalRing, fun _ ↦ inferInstance⟩
    · have := IsLocalizedModule.iso p.asIdeal.primeCompl
        (KaehlerDifferential.map R R A (Localization.AtPrime p.asIdeal))
      have := this.extendScalarsOfIsLocalization
        p.asIdeal.primeCompl (Localization.AtPrime p.asIdeal)
      exact ⟨fun H ↦ H.of_equiv' this.symm, fun H ↦ H.of_equiv' this⟩

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

Goal state before:
pp: R : Type u_1
I : Type u_2
inst✝⁵ : Finite I
f : I → Type u_3
inst✝⁴ : CommRing R
inst✝³ : (i : I) → CommRing (f i)
inst✝² : (i : I) → Algebra R (f i)
val✝ : Fintype I
H : ∀ (i : I), FormallyUnramified R (f i)
B : Type (max u_2 u_3)
inst✝¹ : CommRing B
inst✝ : Algebra R B
J : Ideal B
hJ : J ^ 2 = ⊥
f₁ f₂ : ((i : I) → f i) →ₐ[R] B
e✝ : (Ideal.Quotient.mkₐ R J).comp f₁ = (Ideal.Quotient.mkₐ R J).comp f₂
g : (i : I) → f i
x : I
hf : ∀ (x : (i : I) → f i), f₁ x - f₂ x ∈ J
e : (i : I) → f i := Pi.single x 1
he : IsIdempotentElem e
⊢ f₁ e * (1 - f₂ e) = 0

Tactic:
← Ideal.mem_bot,

Goal state after:
R : Type u_1
I : Type u_2
inst✝⁵ : Finite I
f : I → Type u_3
inst✝⁴ : CommRing R
inst✝³ : (i : I) → CommRing (f i)
inst✝² : (i : I) → Algebra R (f i)
val✝ : Fintype I
H : ∀ (i : I), FormallyUnramified R (f i)
B : Type (max u_2 u_3)
inst✝¹ : CommRing B
inst✝ : Algebra R B
J : Ideal B
hJ : J ^ 2 = ⊥
f₁ f₂ : ((i : I) → f i) →ₐ[R] B
e✝ : (Ideal.Quotient.mkₐ R J).comp f₁ = (Ideal.Quotient.mkₐ R J).comp f₂
g : (i : I) → f i
x : I
hf : ∀ (x : (i : I) → f i), f₁ x - f₂ x ∈ J
e : (i : I) → f i := Pi.single x 1
he : IsIdempotentElem e
⊢ f₁ e * (1 - f₂ e) ∈ ⊥
Module: Mathlib.RingTheory.Unramified.Pi

Goal state before:
pp: R : Type u_1
I : Type u_2
inst✝⁵ : Finite I
f : I → Type u_3
inst✝⁴ : CommRing R
inst✝³ : (i : I) → CommRing (f i)
inst✝² : (i : I) → Algebra R (f i)
val✝ : Fintype I
H : ∀ (i : I), FormallyUnramified R (f i)
B : Type (max u_2 u_3)
inst✝¹ : CommRing B
inst✝ : Algebra R B
J : Ideal B
hJ : J ^ 2 = ⊥
f₁ f₂ : ((i : I) → f i) →ₐ[R] B
e✝ : (Ideal.Quotient.mkₐ R J).comp f₁ = (Ideal.Quotient.mkₐ R J).comp f₂
g : (i : I) → f i
x : I
hf : ∀ (x : (i : I) → f i), f₁ x - f₂ x ∈ J
e : (i : I) → f i := Pi.single x 1
he : IsIdempotentElem e
h₁ : f₁ e * (1 - f₂ e) = 0
⊢ f₂ e * (1 - f₁ e) = 0

Tactic:
← Ideal.mem_bot,

Goal state after:
R : Type u_1
I : Type u_2
inst✝⁵ : Finite I
f : I → Type u_3
inst✝⁴ : CommRing R
inst✝³ : (i : I) → CommRing (f i)
inst✝² : (i : I) → Algebra R (f i)
val✝ : Fintype I
H : ∀ (i : I), FormallyUnramified R (f i)
B : Type (max u_2 u_3)
inst✝¹ : CommRing B
inst✝ : Algebra R B
J : Ideal B
hJ : J ^ 2 = ⊥
f₁ f₂ : ((i : I) → f i) →ₐ[R] B
e✝ : (Ideal.Quotient.mkₐ R J).comp f₁ = (Ideal.Quotient.mkₐ R J).comp f₂
g : (i : I) → f i
x : I
hf : ∀ (x : (i : I) → f i), f₁ x - f₂ x ∈ J
e : (i : I) → f i := Pi.single x 1
he : IsIdempotentElem e
h₁ : f₁ e * (1 - f₂ e) = 0
⊢ f₂ e * (1 - f₁ e) ∈ ⊥
Module: Mathlib.RingTheory.Etale.Field

Goal state before:
pp: case w
K : Type u_1
L : Type u_2
inst✝⁴ : Field K
inst✝³ : Field L
inst✝² : Algebra K L
inst✝¹ : Algebra.IsSeparable K L
inst✝ : EssFiniteType K L
this✝ : FormallyUnramified K L
this : Module.Finite K L
B : Type (max u_1 u_2)
x✝¹ : CommRing B
x✝ : Algebra K B
I : Ideal B
h : I ^ 2 = ⊥
f : L →ₐ[K] B ⧸ I
pb : PowerBasis K L := Field.powerBasisOfFiniteOfSeparable K L
x : B
hx : (Ideal.Quotient.mk I) x = f pb.gen
helper : ∀ (x : B), (IsScalarTower.toAlgHom K B (B ⧸ I)) x = (Ideal.Quotient.mk I) x
hx' : (Ideal.Quotient.mk I) ((aeval x) (minpoly K pb.gen)) = 0
u : B
hu : (aeval x) (derivative (minpoly K pb.gen)) * u + 1 ∈ I
⊢ (1 + (aeval x) (derivative (minpoly K pb.gen)) * u) * (aeval x) (minpoly K pb.gen) = 0

pp: case w.hy
K : Type u_1
L : Type u_2
inst✝⁴ : Field K
inst✝³ : Field L
inst✝² : Algebra K L
inst✝¹ : Algebra.IsSeparable K L
inst✝ : EssFiniteType K L
this✝ : FormallyUnramified K L
this : Module.Finite K L
B : Type (max u_1 u_2)
x✝¹ : CommRing B
x✝ : Algebra K B
I : Ideal B
h : I ^ 2 = ⊥
f : L →ₐ[K] B ⧸ I
pb : PowerBasis K L := Field.powerBasisOfFiniteOfSeparable K L
x : B
hx : (Ideal.Quotient.mk I) x = f pb.gen
helper : ∀ (x : B), (IsScalarTower.toAlgHom K B (B ⧸ I)) x = (Ideal.Quotient.mk I) x
hx' : (Ideal.Quotient.mk I) ((aeval x) (minpoly K pb.gen)) = 0
u : B
hu : (aeval x) (derivative (minpoly K pb.gen)) * u + 1 ∈ I
⊢ (u * (aeval x) (minpoly K pb.gen)) ^ 2 = 0

Tactic:
← Ideal.mem_bot,

Goal state after:
case w
K : Type u_1
L : Type u_2
inst✝⁴ : Field K
inst✝³ : Field L
inst✝² : Algebra K L
inst✝¹ : Algebra.IsSeparable K L
inst✝ : EssFiniteType K L
this✝ : FormallyUnramified K L
this : Module.Finite K L
B : Type (max u_1 u_2)
x✝¹ : CommRing B
x✝ : Algebra K B
I : Ideal B
h : I ^ 2 = ⊥
f : L →ₐ[K] B ⧸ I
pb : PowerBasis K L := Field.powerBasisOfFiniteOfSeparable K L
x : B
hx : (Ideal.Quotient.mk I) x = f pb.gen
helper : ∀ (x : B), (IsScalarTower.toAlgHom K B (B ⧸ I)) x = (Ideal.Quotient.mk I) x
hx' : (Ideal.Quotient.mk I) ((aeval x) (minpoly K pb.gen)) = 0
u : B
hu : (aeval x) (derivative (minpoly K pb.gen)) * u + 1 ∈ I
⊢ (1 + (aeval x) (derivative (minpoly K pb.gen)) * u) * (aeval x) (minpoly K pb.gen) ∈ ⊥

case w.hy
K : Type u_1
L : Type u_2
inst✝⁴ : Field K
inst✝³ : Field L
inst✝² : Algebra K L
inst✝¹ : Algebra.IsSeparable K L
inst✝ : EssFiniteType K L
this✝ : FormallyUnramified K L
this : Module.Finite K L
B : Type (max u_1 u_2)
x✝¹ : CommRing B
x✝ : Algebra K B
I : Ideal B
h : I ^ 2 = ⊥
f : L →ₐ[K] B ⧸ I
pb : PowerBasis K L := Field.powerBasisOfFiniteOfSeparable K L
x : B
hx : (Ideal.Quotient.mk I) x = f pb.gen
helper : ∀ (x : B), (IsScalarTower.toAlgHom K B (B ⧸ I)) x = (Ideal.Quotient.mk I) x
hx' : (Ideal.Quotient.mk I) ((aeval x) (minpoly K pb.gen)) = 0
u : B
hu : (aeval x) (derivative (minpoly K pb.gen)) * u + 1 ∈ I
⊢ (u * (aeval x) (minpoly K pb.gen)) ^ 2 = 0
Module: Mathlib.RingTheory.Etale.Field

Goal state before:
pp: case w.hy
K : Type u_1
L : Type u_2
inst✝⁴ : Field K
inst✝³ : Field L
inst✝² : Algebra K L
inst✝¹ : Algebra.IsSeparable K L
inst✝ : EssFiniteType K L
this✝ : FormallyUnramified K L
this : Module.Finite K L
B : Type (max u_1 u_2)
x✝¹ : CommRing B
x✝ : Algebra K B
I : Ideal B
h : I ^ 2 = ⊥
f : L →ₐ[K] B ⧸ I
pb : PowerBasis K L := Field.powerBasisOfFiniteOfSeparable K L
x : B
hx : (Ideal.Quotient.mk I) x = f pb.gen
helper : ∀ (x : B), (IsScalarTower.toAlgHom K B (B ⧸ I)) x = (Ideal.Quotient.mk I) x
hx' : (Ideal.Quotient.mk I) ((aeval x) (minpoly K pb.gen)) = 0
u : B
hu : (aeval x) (derivative (minpoly K pb.gen)) * u + 1 ∈ I
⊢ (u * (aeval x) (minpoly K pb.gen)) ^ 2 = 0

Tactic:
← Ideal.mem_bot,

Goal state after:
case w.hy
K : Type u_1
L : Type u_2
inst✝⁴ : Field K
inst✝³ : Field L
inst✝² : Algebra K L
inst✝¹ : Algebra.IsSeparable K L
inst✝ : EssFiniteType K L
this✝ : FormallyUnramified K L
this : Module.Finite K L
B : Type (max u_1 u_2)
x✝¹ : CommRing B
x✝ : Algebra K B
I : Ideal B
h : I ^ 2 = ⊥
f : L →ₐ[K] B ⧸ I
pb : PowerBasis K L := Field.powerBasisOfFiniteOfSeparable K L
x : B
hx : (Ideal.Quotient.mk I) x = f pb.gen
helper : ∀ (x : B), (IsScalarTower.toAlgHom K B (B ⧸ I)) x = (Ideal.Quotient.mk I) x
hx' : (Ideal.Quotient.mk I) ((aeval x) (minpoly K pb.gen)) = 0
u : B
hu : (aeval x) (derivative (minpoly K pb.gen)) * u + 1 ∈ I
⊢ (u * (aeval x) (minpoly K pb.gen)) ^ 2 ∈ ⊥
Module: Mathlib.RingTheory.Kaehler.TensorProduct

Goal state before:
pp: R : Type u_1
S : Type u_2
A : Type u_3
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : Algebra R S
inst✝¹ : CommRing A
inst✝ : Algebra R A
a : A
x y : S ⊗[R] Ω[A⁄R]
⊢ a • (x + y) = a • x + a • y

Tactic:
change (TensorProduct.comm R S Ω[A⁄R]).symm (a • (TensorProduct.comm R S Ω[A⁄R]) (x + y)) = _
  rw [map_add, smul_add, map_add]
  rfl

Goal state after:
Module: Mathlib.RingTheory.Etale.Locus

Goal state before:
pp: R : Type u_1
A : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
inst✝ : FinitePresentation R A
⊢ IsOpen (etaleLocus R A)

Tactic:
rw [etaleLocus_eq_unramfiedLocus_inter_smoothLocus]

Goal state after:
R : Type u_1
A : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
inst✝ : FinitePresentation R A
⊢ IsOpen (unramifiedLocus R A ∩ smoothLocus R A)
Module: Mathlib.RingTheory.AdicCompletion.Algebra

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing S
I : Ideal R
M : Type u_3
inst✝¹ : AddCommGroup M
inst✝ : Module R M
r : AdicCompletion I R
x : AdicCompletion I M
m n : ℕ
hmn : m ≤ n
⊢ (transitionMap I M hmn) ((fun n ↦ (eval I R n) r • (eval I M n) x) n) = (fun n ↦ (eval I R n) r • (eval I M n) x) m

Tactic:
apply induction_on I R r (fun r ↦ ?_)
      apply induction_on I M x (fun x ↦ ?_)
      simp only [coe_eval, mapQ_eq_factor, mk_apply_coe, mkQ_apply, Ideal.Quotient.mk_eq_mk,
        mk_smul_mk, map_smul, mapQ_apply, LinearMap.id_coe, id_eq]
      rw [smul_mk I hmn]

Goal state after:
Module: Mathlib.RingTheory.AdicCompletion.AsTensorProduct

Goal state before:
pp: R : Type u_1
inst✝³ : CommRing R
I : Ideal R
M : Type u_2
inst✝² : AddCommGroup M
inst✝¹ : Module R M
inst✝ : Module.Finite R M
n : ℕ
p : (Fin n → R) →ₗ[R] M
hp : Function.Surjective ⇑p
f : AdicCompletion I R ⊗[R] (Fin n → R) →ₗ[AdicCompletion I R] AdicCompletion I M :=
  ofTensorProduct I M ∘ₗ LinearMap.baseChange (AdicCompletion I R) p
g : AdicCompletion I R ⊗[R] (Fin n → R) →ₗ[AdicCompletion I R] AdicCompletion I M :=
  map I p ∘ₗ ofTensorProduct I (Fin n → R)
hfg : f = g
⊢ Function.Surjective ⇑f

Tactic:
simp only [hfg, LinearMap.coe_comp, g]

Goal state after:
R : Type u_1
inst✝³ : CommRing R
I : Ideal R
M : Type u_2
inst✝² : AddCommGroup M
inst✝¹ : Module R M
inst✝ : Module.Finite R M
n : ℕ
p : (Fin n → R) →ₗ[R] M
hp : Function.Surjective ⇑p
f : AdicCompletion I R ⊗[R] (Fin n → R) →ₗ[AdicCompletion I R] AdicCompletion I M :=
  ofTensorProduct I M ∘ₗ LinearMap.baseChange (AdicCompletion I R) p
g : AdicCompletion I R ⊗[R] (Fin n → R) →ₗ[AdicCompletion I R] AdicCompletion I M :=
  map I p ∘ₗ ofTensorProduct I (Fin n → R)
hfg : f = g
⊢ Function.Surjective (⇑(map I p) ∘ ⇑(ofTensorProduct I (Fin n → R)))
Module: Mathlib.RingTheory.AdicCompletion.Exactness

Goal state before:
pp: R : Type u
inst✝⁸ : CommRing R
I : Ideal R
M : Type u
inst✝⁷ : AddCommGroup M
inst✝⁶ : Module R M
N : Type u
inst✝⁵ : AddCommGroup N
inst✝⁴ : Module R N
P : Type u
inst✝³ : AddCommGroup P
inst✝² : Module R P
inst✝¹ : IsNoetherianRing R
inst✝ : Module.Finite R N
f : M →ₗ[R] N
g : N →ₗ[R] P
hf : Function.Injective ⇑f
hfg : Function.Exact ⇑f ⇑g
hg : Function.Surjective ⇑g
y : AdicCompletion I N
b : AdicCauchySequence I N
hz : (mk I N) b ∈ (map I g).ker
⊢ (mk I N) b ∈ (map I f).range

Tactic:
obtain ⟨k, hk⟩ := Ideal.exists_pow_inf_eq_pow_smul I (LinearMap.range f)

Goal state after:
R : Type u
inst✝⁸ : CommRing R
I : Ideal R
M : Type u
inst✝⁷ : AddCommGroup M
inst✝⁶ : Module R M
N : Type u
inst✝⁵ : AddCommGroup N
inst✝⁴ : Module R N
P : Type u
inst✝³ : AddCommGroup P
inst✝² : Module R P
inst✝¹ : IsNoetherianRing R
inst✝ : Module.Finite R N
f : M →ₗ[R] N
g : N →ₗ[R] P
hf : Function.Injective ⇑f
hfg : Function.Exact ⇑f ⇑g
hg : Function.Surjective ⇑g
y : AdicCompletion I N
b : AdicCauchySequence I N
hz : (mk I N) b ∈ (map I g).ker
k : ℕ
hk : ∀ n ≥ k, I ^ n • ⊤ ⊓ f.range = I ^ (n - k) • (I ^ k • ⊤ ⊓ f.range)
⊢ (mk I N) b ∈ (map I f).range
Module: Mathlib.RingTheory.AdicCompletion.AsTensorProduct

Goal state before:
pp: R : Type u
inst✝⁷ : CommRing R
I : Ideal R
inst✝⁶ : IsNoetherianRing R
M : Type u
inst✝⁵ : AddCommGroup M
inst✝⁴ : Module R M
N : Type u
inst✝³ : AddCommGroup N
inst✝² : Module R N
f : M →ₗ[R] N
inst✝¹ : Module.Finite R M
inst✝ : Module.Finite R N
⊢ AlgebraTensorModule.map LinearMap.id f =
    ↑(ofTensorProductEquivOfFiniteNoetherian I N).symm ∘ₗ map I f ∘ₗ ↑(ofTensorProductEquivOfFiniteNoetherian I M)

Tactic:
by
  rw [coe_ofTensorProductEquivOfFiniteNoetherian, ofTensorProduct_naturality I f]
  ext x
  simp

Goal state after:
Module: Mathlib.RingTheory.Extension.Presentation.Submersive

Goal state before:
pp: R : Type u
S : Type v
ι : Type w
σ : Type t
inst✝⁸ : CommRing R
inst✝⁷ : CommRing S
inst✝⁶ : Algebra R S
ι' : Type u_1
σ' : Type u_2
T : Type u_3
inst✝⁵ : CommRing T
inst✝⁴ : Algebra R T
inst✝³ : Algebra S T
inst✝² : IsScalarTower R S T
Q : PreSubmersivePresentation S T ι' σ'
P : PreSubmersivePresentation R S ι σ
inst✝¹ : Fintype σ
inst✝ : Fintype σ'
⊢ (Q.comp P).jacobiMatrix.toBlocks₁₂ = 0

Tactic:
ext i j : 1
  simp [Matrix.toBlocks₁₂, jacobiMatrix_comp_inl_inr]

Goal state after:
Module: Mathlib.RingTheory.Extension.Presentation.Submersive

Goal state before:
pp: case mul_X
R : Type u
S : Type v
ι : Type w
σ : Type t
inst✝⁸ : CommRing R
inst✝⁷ : CommRing S
inst✝⁶ : Algebra R S
ι' : Type u_1
σ' : Type u_2
T : Type u_3
inst✝⁵ : CommRing T
inst✝⁴ : Algebra R T
inst✝³ : Algebra S T
inst✝² : IsScalarTower R S T
Q : PreSubmersivePresentation S T ι' σ'
P : PreSubmersivePresentation R S ι σ
inst✝¹ : Fintype σ
inst✝ : Fintype σ'
i✝ j : σ
p : MvPolynomial ι R
i : ι
hp :
  { toRingHom := eval₂Hom (algebraMap R T) (Q.comp P).val, commutes' := ⋯ } ((rename Sum.inr) p) =
    eval₂ (algebraMap R T) (fun i ↦ (algebraMap S T) (P.val i)) p
⊢ { toRingHom := eval₂Hom (algebraMap R T) (Q.comp P).val, commutes' := ⋯ } ((rename Sum.inr) (p * X i)) =
    eval₂ (algebraMap R T) (fun i ↦ (algebraMap S T) (P.val i)) (p * X i)

Tactic:
simp only [map_mul, eval₂_mul, hp]
    simp [Presentation.toGenerators_comp, toPresentation_comp]

Goal state after:
Module: Mathlib.RingTheory.Extension.Cotangent.LocalizationAway

Goal state before:
pp: R : Type u_1
S : Type u_2
T : Type u_3
ι : Type u_4
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : Algebra R S
inst✝⁴ : CommRing T
inst✝³ : Algebra R T
inst✝² : Algebra S T
inst✝¹ : IsScalarTower R S T
g : S
inst✝ : IsLocalization.Away g T
P : Generators R S ι
Q : Generators S T Unit := localizationAway T g
algInst✝ : Algebra P.Ring ((localizationAway T g).comp P).Ring := ((localizationAway T g).toComp P).toAlgHom.toAlgebra
f : P.Ring ⧸ P.ker ^ 2 := (Ideal.Quotient.mk (P.ker ^ 2)) (P.σ g)
π : ((localizationAway T g).comp P).Ring →ₐ[R] Localization.Away ((Ideal.Quotient.mk (P.ker ^ 2)) (P.σ g)) :=
  compLocalizationAwayAlgHom T g P
x : ↥P.toExtension.ker
hx :
  (lift
        (↑S
          (↑(LinearMap.ringLmapEquivSelf T T (P.toExtension.Cotangent →ₗ[S] (Q.comp P).toExtension.Cotangent)).symm
            (Extension.Cotangent.map (Q.toComp P).toExtensionHom))))
      (((TensorProduct.mk S T P.toExtension.Cotangent) 1) (Extension.Cotangent.mk x)) =
    0
⊢ (algebraMap P.Ring (Localization.Away f)) ↑x = 0

Tactic:
← compLocalizationAwayAlgHom_toAlgHom_toComp (T := T)

Goal state after:
R : Type u_1
S : Type u_2
T : Type u_3
ι : Type u_4
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : Algebra R S
inst✝⁴ : CommRing T
inst✝³ : Algebra R T
inst✝² : Algebra S T
inst✝¹ : IsScalarTower R S T
g : S
inst✝ : IsLocalization.Away g T
P : Generators R S ι
Q : Generators S T Unit := localizationAway T g
algInst✝ : Algebra P.Ring ((localizationAway T g).comp P).Ring := ((localizationAway T g).toComp P).toAlgHom.toAlgebra
f : P.Ring ⧸ P.ker ^ 2 := (Ideal.Quotient.mk (P.ker ^ 2)) (P.σ g)
π : ((localizationAway T g).comp P).Ring →ₐ[R] Localization.Away ((Ideal.Quotient.mk (P.ker ^ 2)) (P.σ g)) :=
  compLocalizationAwayAlgHom T g P
x : ↥P.toExtension.ker
hx :
  (lift
        (↑S
          (↑(LinearMap.ringLmapEquivSelf T T (P.toExtension.Cotangent →ₗ[S] (Q.comp P).toExtension.Cotangent)).symm
            (Extension.Cotangent.map (Q.toComp P).toExtensionHom))))
      (((TensorProduct.mk S T P.toExtension.Cotangent) 1) (Extension.Cotangent.mk x)) =
    0
⊢ (compLocalizationAwayAlgHom T g P) (((localizationAway T g).toComp P).toAlgHom ↑x) = 0
Module: Mathlib.RingTheory.Extension.Cotangent.Basis

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 : FinitePresentation R S
α : Type u_4
P : Generators R S α
inst✝ : Finite α
σ : Type u_5
b₀ : Module.Basis σ S P.toExtension.Cotangent
h✝ : Nontrivial S
f : P.toExtension.Cotangent → ↥P.toExtension.ker
hf : ∀ (b : P.toExtension.Cotangent), Extension.Cotangent.mk (f b) = b
v : σ → ↥P.ker := fun i ↦ f (b₀ i)
J : Ideal P.Ring := Ideal.span (Set.range (Subtype.val ∘ v))
hJfg : P.ker.FG
hJ✝ : J ≤ P.ker
hJ : P.ker ≤ J ⊔ P.ker • P.ker
g : P.Ring
hgmem : g - 1 ∈ P.ker
hg : g • P.ker ≤ J
⊢ ∃ P' b, P'.val ∘ Sum.inr = P.val ∧ ∀ (r : Unit ⊕ σ), b r = Extension.Cotangent.mk ⟨P'.relation r, ⋯⟩

Tactic:
let D : Aux P b₀ := { f := f, hf := hf, g := g, hgmem := hgmem, hg := hg }

Goal state after:
R : Type u_1
S : Type u_2
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : Algebra R S
inst✝¹ : FinitePresentation R S
α : Type u_4
P : Generators R S α
inst✝ : Finite α
σ : Type u_5
b₀ : Module.Basis σ S P.toExtension.Cotangent
h✝ : Nontrivial S
f : P.toExtension.Cotangent → ↥P.toExtension.ker
hf : ∀ (b : P.toExtension.Cotangent), Extension.Cotangent.mk (f b) = b
v : σ → ↥P.ker := fun i ↦ f (b₀ i)
J : Ideal P.Ring := Ideal.span (Set.range (Subtype.val ∘ v))
hJfg : P.ker.FG
hJ✝ : J ≤ P.ker
hJ : P.ker ≤ J ⊔ P.ker • P.ker
g : P.Ring
hgmem : g - 1 ∈ P.ker
hg : g • P.ker ≤ J
D : Aux P b₀ := { f := f, hf := hf, g := g, hgmem := hgmem, hg := hg }
⊢ ∃ P' b, P'.val ∘ Sum.inr = P.val ∧ ∀ (r : Unit ⊕ σ), b r = Extension.Cotangent.mk ⟨P'.relation r, ⋯⟩
Module: Mathlib.RingTheory.Extension.Cotangent.Basis

Goal state before:
pp: case inr
R : Type u_1
S : Type u_2
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : Algebra R S
inst✝¹ : FinitePresentation R S
α : Type u_4
P : Generators R S α
inst✝ : Finite α
σ : Type u_5
b₀ : Module.Basis σ S P.toExtension.Cotangent
h✝ : Nontrivial S
f : P.toExtension.Cotangent → ↥P.toExtension.ker
hf : ∀ (b : P.toExtension.Cotangent), Extension.Cotangent.mk (f b) = b
v : σ → ↥P.ker := fun i ↦ f (b₀ i)
J : Ideal P.Ring := Ideal.span (Set.range (Subtype.val ∘ v))
hJfg : P.ker.FG
hJ : J ≤ P.ker
⊢ ⊤ ≤ Submodule.comap (Submodule.subtype P.ker) (Ideal.span (Set.range (⇑(Submodule.subtype P.ker) ∘ v))) ⊔ P.ker • ⊤

Tactic:
Ideal.span,

Goal state after:
case inr
R : Type u_1
S : Type u_2
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : Algebra R S
inst✝¹ : FinitePresentation R S
α : Type u_4
P : Generators R S α
inst✝ : Finite α
σ : Type u_5
b₀ : Module.Basis σ S P.toExtension.Cotangent
h✝ : Nontrivial S
f : P.toExtension.Cotangent → ↥P.toExtension.ker
hf : ∀ (b : P.toExtension.Cotangent), Extension.Cotangent.mk (f b) = b
v : σ → ↥P.ker := fun i ↦ f (b₀ i)
J : Ideal P.Ring := Ideal.span (Set.range (Subtype.val ∘ v))
hJfg : P.ker.FG
hJ : J ≤ P.ker
⊢ ⊤ ≤
    Submodule.comap (Submodule.subtype P.ker) (Submodule.span P.Ring (Set.range (⇑(Submodule.subtype P.ker) ∘ v))) ⊔
      P.ker • ⊤
Module: Mathlib.RingTheory.Smooth.NoetherianDescent

Goal state before:
pp: R : Type u_1
inst✝⁵ : CommRing R
A : Type u
B : Type u_2
inst✝⁴ : CommRing A
inst✝³ : Algebra R A
inst✝² : CommRing B
inst✝¹ : Algebra A B
inst✝ : Etale A B
⊢ ∃ A₀ B₀ x x_1, A₀.FG ∧ Etale (↥A₀) B₀ ∧ Nonempty (B ≃ₐ[A] A ⊗[↥A₀] B₀)

Tactic:
by
  simp only [Etale.iff_isStandardSmoothOfRelativeDimension_zero] at *
  exact IsStandardSmoothOfRelativeDimension.exists_subalgebra_fg ..

Goal state after:
Module: Mathlib.AlgebraicGeometry.Morphisms.Smooth

Goal state before:
pp: X Y : Scheme
f : X ⟶ Y
inst✝ : LocallyOfFinitePresentation f
x : ↥X
H : (CommRingCat.Hom.hom (Scheme.Hom.stalkMap f x)).FormallySmooth
⊢ ∃ U,
    ∃ (_ : IsAffineOpen U),
      ∃ V, ∃ (_ : IsAffineOpen V) (hVU : V ≤ f ⁻¹ᵁ U), x ∈ V ∧ (CommRingCat.Hom.hom (Scheme.Hom.appLE f U V hVU)).Smooth

Tactic:
obtain ⟨_, ⟨U, hU, rfl⟩, hxU, -⟩ :=
    Y.isBasis_affineOpens.exists_subset_of_mem_open (Set.mem_univ (f x)) isOpen_univ

Goal state after:
X Y : Scheme
f : X ⟶ Y
inst✝ : LocallyOfFinitePresentation f
x : ↥X
H : (CommRingCat.Hom.hom (Scheme.Hom.stalkMap f x)).FormallySmooth
U : TopologicalSpace.Opens ↥Y
hU : U ∈ Y.affineOpens
hxU : f x ∈ ↑U
⊢ ∃ U,
    ∃ (_ : IsAffineOpen U),
      ∃ V, ∃ (_ : IsAffineOpen V) (hVU : V ≤ f ⁻¹ᵁ U), x ∈ V ∧ (CommRingCat.Hom.hom (Scheme.Hom.appLE f U V hVU)).Smooth
Module: Mathlib.AlgebraicGeometry.Morphisms.Smooth

Goal state before:
pp: X Y : Scheme
f : X ⟶ Y
inst✝ : Smooth f
x : ↥X
⊢ x ∈ smoothLocus f

Tactic:
obtain ⟨_, ⟨U, hU, rfl⟩, hxU, -⟩ :=
    Y.isBasis_affineOpens.exists_subset_of_mem_open (Set.mem_univ (f x)) isOpen_univ

Goal state after:
X Y : Scheme
f : X ⟶ Y
inst✝ : Smooth f
x : ↥X
U : TopologicalSpace.Opens ↥Y
hU : U ∈ Y.affineOpens
hxU : f x ∈ ↑U
⊢ x ∈ smoothLocus f
Module: Mathlib.AlgebraicGeometry.Morphisms.Etale

Goal state before:
pp: R S : Type u_1
inst✝¹ : CommRing R
inst✝ : CommRing S
f : R →+* S
this : @RingHom.Etale = @RingHom.IsStandardSmoothOfRelativeDimension 0
⊢ f.Etale ↔ RingHom.Locally (fun {R S} [CommRing R] [CommRing S] ↦ RingHom.Etale) f

Tactic:
RingHom.locally_iff_of_localizationSpanTarget

Goal state after:
R S : Type u_1
inst✝¹ : CommRing R
inst✝ : CommRing S
f : R →+* S
this : @RingHom.Etale = @RingHom.IsStandardSmoothOfRelativeDimension 0
⊢ f.Etale ↔ f.Etale

case hPi
R S : Type u_1
inst✝¹ : CommRing R
inst✝ : CommRing S
f : R →+* S
this : @RingHom.Etale = @RingHom.IsStandardSmoothOfRelativeDimension 0
⊢ RingHom.RespectsIso fun {R S} [CommRing R] [CommRing S] ↦ RingHom.Etale

case hPs
R S : Type u_1
inst✝¹ : CommRing R
inst✝ : CommRing S
f : R →+* S
this : @RingHom.Etale = @RingHom.IsStandardSmoothOfRelativeDimension 0
⊢ RingHom.OfLocalizationSpanTarget fun {R S} [CommRing R] [CommRing S] ↦ RingHom.Etale
Module: Mathlib.RingTheory.Conductor

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
x : S
I : Ideal R
p : R
z : S
hp : p ∈ comap (algebraMap R S) (conductor R x)
hz' : z ∈ span (⇑(algebraMap R S) '' ↑I)
⊢ (algebraMap R S) p * z ∈ ⇑(algebraMap (↥R[x]) S) '' ↑(Ideal.map (algebraMap R ↥R[x]) I)

Tactic:
Ideal.span,

Goal state after:
R : Type u_1
S : Type u_2
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
x : S
I : Ideal R
p : R
z : S
hp : p ∈ comap (algebraMap R S) (conductor R x)
hz' : z ∈ Submodule.span S (⇑(algebraMap R S) '' ↑I)
⊢ (algebraMap R S) p * z ∈ ⇑(algebraMap (↥R[x]) S) '' ↑(Ideal.map (algebraMap R ↥R[x]) I)
Module: Mathlib.RingTheory.Conductor

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
x : S
I : Ideal R
p : R
z : S
hp : p ∈ comap (algebraMap R S) (conductor R x)
l : R →₀ S
H : l ∈ Finsupp.supported S S ↑I
H' : (Finsupp.linearCombination S ⇑(algebraMap R S)) l = z
⊢ (algebraMap R S) p * z ∈ ⇑(algebraMap (↥R[x]) S) '' ↑(Ideal.map (algebraMap R ↥R[x]) I)

Tactic:
Finsupp.linearCombination_apply

Goal state after:
R : Type u_1
S : Type u_2
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
x : S
I : Ideal R
p : R
z : S
hp : p ∈ comap (algebraMap R S) (conductor R x)
l : R →₀ S
H : l ∈ Finsupp.supported S S ↑I
H' : (l.sum fun i a ↦ a • (algebraMap R S) i) = z
⊢ (algebraMap R S) p * z ∈ ⇑(algebraMap (↥R[x]) S) '' ↑(Ideal.map (algebraMap R ↥R[x]) I)