mathlib-initiative/mathlib-tactics huggingface dataset:
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 - f₂ e * f₁ e = -(f₂ e * f₁ e - f₂ e * f₂ e)

Tactic:
mul_one,

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 - f₂ e * f₁ e = -(f₂ e * f₁ e - f₂ e * f₂ e)
Module: Mathlib.RingTheory.Smooth.Pi

Goal state before:
pp: R : Type u_1
I : Type u_2
A : I → Type u_3
inst✝³ : CommRing R
inst✝² : (i : I) → CommRing (A i)
inst✝¹ : (i : I) → Algebra R (A i)
inst✝ : Finite I
val✝ : Fintype I
H : ∀ (i : I), FormallySmooth R (A i)
B : Type (max u_1 u_2 u_3)
x✝¹ : CommRing B
x✝ : Algebra R B
J : Ideal B
hJ : J ^ 2 = ⊥
g : ((i : I) → A i) →ₐ[R] B ⧸ J
hJ' : ∀ x ∈ RingHom.ker (Ideal.Quotient.mk J), IsNilpotent x
e : I → B
he : CompleteOrthogonalIdempotents e
he' : ∀ (i : I), (Ideal.Quotient.mk J) (e i) = g (Pi.single i 1)
iso : B ≃ₐ[R] (i : I) → B ⧸ Ideal.span {1 - e i} :=
  let __spread.0 := AlgHom.pi fun i ↦ Ideal.Quotient.mkₐ R (Ideal.span {1 - e i});
  let __spread.1 := Equiv.ofBijective ⇑(RingHom.pi fun i ↦ Ideal.Quotient.mk (Ideal.span {1 - e i})) ⋯;
  { toFun := (↑↑__spread.0.toRingHom).toFun, invFun := __spread.1.invFun, left_inv := ⋯, right_inv := ⋯, map_mul' := ⋯,
    map_add' := ⋯, commutes' := ⋯ }
J' : (i : I) → Ideal (B ⧸ Ideal.span {1 - e i}) := fun i ↦ Ideal.map (Ideal.Quotient.mk (Ideal.span {1 - e i})) J
ι : (i : I) → B ⧸ J →ₐ[R] (B ⧸ Ideal.span {1 - e i}) ⧸ J' i :=
  fun i ↦ Ideal.quotientMapₐ (J' i) (IsScalarTower.toAlgHom R B (B ⧸ Ideal.span {1 - e i})) ⋯
i : I
c : B ⧸ J
hix : (ι i) ((Ideal.Quotient.mk J) (1 - e i) * c) = 0
⊢ (Ideal.Quotient.mk J) (e i * 1 - e i * e i) * c = 0

Tactic:
mul_one,

Goal state after:
R : Type u_1
I : Type u_2
A : I → Type u_3
inst✝³ : CommRing R
inst✝² : (i : I) → CommRing (A i)
inst✝¹ : (i : I) → Algebra R (A i)
inst✝ : Finite I
val✝ : Fintype I
H : ∀ (i : I), FormallySmooth R (A i)
B : Type (max u_1 u_2 u_3)
x✝¹ : CommRing B
x✝ : Algebra R B
J : Ideal B
hJ : J ^ 2 = ⊥
g : ((i : I) → A i) →ₐ[R] B ⧸ J
hJ' : ∀ x ∈ RingHom.ker (Ideal.Quotient.mk J), IsNilpotent x
e : I → B
he : CompleteOrthogonalIdempotents e
he' : ∀ (i : I), (Ideal.Quotient.mk J) (e i) = g (Pi.single i 1)
iso : B ≃ₐ[R] (i : I) → B ⧸ Ideal.span {1 - e i} :=
  let __spread.0 := AlgHom.pi fun i ↦ Ideal.Quotient.mkₐ R (Ideal.span {1 - e i});
  let __spread.1 := Equiv.ofBijective ⇑(RingHom.pi fun i ↦ Ideal.Quotient.mk (Ideal.span {1 - e i})) ⋯;
  { toFun := (↑↑__spread.0.toRingHom).toFun, invFun := __spread.1.invFun, left_inv := ⋯, right_inv := ⋯, map_mul' := ⋯,
    map_add' := ⋯, commutes' := ⋯ }
J' : (i : I) → Ideal (B ⧸ Ideal.span {1 - e i}) := fun i ↦ Ideal.map (Ideal.Quotient.mk (Ideal.span {1 - e i})) J
ι : (i : I) → B ⧸ J →ₐ[R] (B ⧸ Ideal.span {1 - e i}) ⧸ J' i :=
  fun i ↦ Ideal.quotientMapₐ (J' i) (IsScalarTower.toAlgHom R B (B ⧸ Ideal.span {1 - e i})) ⋯
i : I
c : B ⧸ J
hix : (ι i) ((Ideal.Quotient.mk J) (1 - e i) * c) = 0
⊢ (Ideal.Quotient.mk J) (e i - e i * e i) * c = 0
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
h₂ : f₂ e * (1 - f₁ e) = 0
⊢ f₂ e - f₁ e * f₂ e = f₂ e * 1 - f₂ e * f₁ e

Tactic:
mul_one,

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
h₂ : f₂ e * (1 - f₁ e) = 0
⊢ f₂ e - f₁ e * f₂ e = f₂ e - f₂ e * f₁ 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
h₂ : f₂ e * (1 - f₁ e) = 0
H : f₁ e = f₂ e
J' : Ideal B := Ideal.span {1 - f₁ e}
f₁' : f x →ₐ[R] B ⧸ J' :=
  AlgHom.ofLinearMap (((Ideal.Quotient.mkₐ R J').comp f₁).toLinearMap ∘ₗ LinearMap.single R f x) ⋯ ⋯
f₂' : f x →ₐ[R] B ⧸ J' :=
  AlgHom.ofLinearMap (((Ideal.Quotient.mkₐ R J').comp f₂).toLinearMap ∘ₗ LinearMap.single R f x) ⋯ ⋯
this : f₁' = f₂'
c : B
hc : f₁ e * f₁ (Pi.single x (g x)) - f₁ e * f₂ (Pi.single x (g x)) = (f₁ e * 1 - f₁ e * f₁ e) * c
⊢ f₁ (Pi.single x (g x)) = f₂ (Pi.single x (g x))

Tactic:
mul_one,

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
h₂ : f₂ e * (1 - f₁ e) = 0
H : f₁ e = f₂ e
J' : Ideal B := Ideal.span {1 - f₁ e}
f₁' : f x →ₐ[R] B ⧸ J' :=
  AlgHom.ofLinearMap (((Ideal.Quotient.mkₐ R J').comp f₁).toLinearMap ∘ₗ LinearMap.single R f x) ⋯ ⋯
f₂' : f x →ₐ[R] B ⧸ J' :=
  AlgHom.ofLinearMap (((Ideal.Quotient.mkₐ R J').comp f₂).toLinearMap ∘ₗ LinearMap.single R f x) ⋯ ⋯
this : f₁' = f₂'
c : B
hc : f₁ e * f₁ (Pi.single x (g x)) - f₁ e * f₂ (Pi.single x (g x)) = (f₁ e - f₁ e * f₁ e) * c
⊢ f₁ (Pi.single x (g x)) = f₂ (Pi.single x (g x))
Module: Mathlib.RingTheory.Etale.Field

Goal state before:
pp: case h
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✝¹ : 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
this : IsUnit ((Ideal.Quotient.mk I) ((aeval x) (derivative (minpoly K pb.gen))))
u : B
hu : (Ideal.Quotient.mk I) u = -↑this.unit⁻¹
⊢ (Ideal.Quotient.mk I) ((aeval x) (derivative (minpoly K pb.gen))) * -↑this.unit⁻¹ + 1 = 0

Tactic:
mul_neg,

Goal state after:
case h
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✝¹ : 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
this : IsUnit ((Ideal.Quotient.mk I) ((aeval x) (derivative (minpoly K pb.gen))))
u : B
hu : (Ideal.Quotient.mk I) u = -↑this.unit⁻¹
⊢ -((Ideal.Quotient.mk I) ((aeval x) (derivative (minpoly K pb.gen))) * ↑this.unit⁻¹) + 1 = 0
Module: Mathlib.RingTheory.Kaehler.TensorProduct

Goal state before:
pp: R : Type u_1
S : Type u_2
A : Type u_3
B : Type u_4
inst✝¹⁰ : CommRing R
inst✝⁹ : CommRing S
inst✝⁸ : Algebra R S
inst✝⁷ : CommRing A
inst✝⁶ : CommRing B
inst✝⁵ : Algebra R A
inst✝⁴ : Algebra R B
inst✝³ : Algebra A B
inst✝² : Algebra S B
inst✝¹ : IsScalarTower R A B
inst✝ : IsScalarTower R S B
h : Algebra.IsPushout R S A B
b : B
x : S ⊗[R] Ω[A⁄R]
⊢ (LinearMap.liftBaseChange S (↑R (map R S A B))) (b • x) = b • (LinearMap.liftBaseChange S (↑R (map R S A B))) x

Tactic:
induction b using h.1.inductionOn with

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

Goal state before:
pp: case tmul.tmul
R : Type u_1
S : Type u_2
A : Type u_3
B : Type u_4
inst✝¹⁰ : CommRing R
inst✝⁹ : CommRing S
inst✝⁸ : Algebra R S
inst✝⁷ : CommRing A
inst✝⁶ : CommRing B
inst✝⁵ : Algebra R A
inst✝⁴ : Algebra R B
inst✝³ : Algebra A B
inst✝² : Algebra S B
inst✝¹ : IsScalarTower R A B
inst✝ : IsScalarTower R S B
h : Algebra.IsPushout R S A B
this : Algebra.IsPushout R A S B
e₁ : B ⊗[A] Ω[A⁄R] ≃ₗ[A] Ω[A⁄R] ⊗[R] S :=
  AlgebraTensorModule.congr (↑(Algebra.IsPushout.equiv R A S B).symm) (LinearEquiv.refl A Ω[A⁄R]) ≪≫ₗ
      TensorProduct.comm A (A ⊗[R] S) Ω[A⁄R] ≪≫ₗ
    AlgebraTensorModule.cancelBaseChange R A A Ω[A⁄R] S
e₂ : B ⊗[A] Ω[A⁄R] ≃ₗ[R] Ω[B⁄S] :=
  LinearEquiv.restrictScalars R e₁ ≪≫ₗ TensorProduct.comm R Ω[A⁄R] S ≪≫ₗ
    LinearEquiv.restrictScalars R (tensorKaehlerEquivBase R S A B)
a : A
b : S
x : B
y : Ω[A⁄R]
⊢ e₂ ((Algebra.IsPushout.equiv R A S B) (a ⊗ₜ[R] b) • x ⊗ₜ[A] y) =
    (Algebra.IsPushout.equiv R A S B) (a ⊗ₜ[R] b) • e₂ (x ⊗ₜ[A] y)

Tactic:
obtain ⟨x, rfl⟩ := (Algebra.IsPushout.equiv R A S B).surjective x

Goal state after:
case tmul.tmul
R : Type u_1
S : Type u_2
A : Type u_3
B : Type u_4
inst✝¹⁰ : CommRing R
inst✝⁹ : CommRing S
inst✝⁸ : Algebra R S
inst✝⁷ : CommRing A
inst✝⁶ : CommRing B
inst✝⁵ : Algebra R A
inst✝⁴ : Algebra R B
inst✝³ : Algebra A B
inst✝² : Algebra S B
inst✝¹ : IsScalarTower R A B
inst✝ : IsScalarTower R S B
h : Algebra.IsPushout R S A B
this : Algebra.IsPushout R A S B
e₁ : B ⊗[A] Ω[A⁄R] ≃ₗ[A] Ω[A⁄R] ⊗[R] S :=
  AlgebraTensorModule.congr (↑(Algebra.IsPushout.equiv R A S B).symm) (LinearEquiv.refl A Ω[A⁄R]) ≪≫ₗ
      TensorProduct.comm A (A ⊗[R] S) Ω[A⁄R] ≪≫ₗ
    AlgebraTensorModule.cancelBaseChange R A A Ω[A⁄R] S
e₂ : B ⊗[A] Ω[A⁄R] ≃ₗ[R] Ω[B⁄S] :=
  LinearEquiv.restrictScalars R e₁ ≪≫ₗ TensorProduct.comm R Ω[A⁄R] S ≪≫ₗ
    LinearEquiv.restrictScalars R (tensorKaehlerEquivBase R S A B)
a : A
b : S
y : Ω[A⁄R]
x : A ⊗[R] S
⊢ e₂ ((Algebra.IsPushout.equiv R A S B) (a ⊗ₜ[R] b) • (Algebra.IsPushout.equiv R A S B) x ⊗ₜ[A] y) =
    (Algebra.IsPushout.equiv R A S B) (a ⊗ₜ[R] b) • e₂ ((Algebra.IsPushout.equiv R A S B) x ⊗ₜ[A] y)
Module: Mathlib.RingTheory.AdicCompletion.Functoriality

Goal state before:
pp: case right
R : Type u_1
inst✝⁴ : CommRing R
I : Ideal R
M : Type u_2
inst✝³ : AddCommGroup M
inst✝² : Module R M
N : Type u_3
inst✝¹ : AddCommGroup N
inst✝ : Module R N
f : M →ₗ[R] N
h : Function.Surjective ⇑((I • ⊤).mkQ ∘ₗ f)
y✝ : N
n : ℕ
r : R
hr : r ∈ I ^ n
y : N
hn✝ : y ∈ ⊤
x : M
hx : f x ≡ y [SMOD I • ⊤]
⊢ r • f x ≡ r • y [SMOD I ^ n • I • ⊤]

Tactic:
exact SModEq.smul' hx hr

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

Goal state before:
pp: case property
R : Type u_1
inst✝⁴ : CommRing R
I : Ideal R
M : Type u_2
inst✝³ : AddCommGroup M
inst✝² : Module R M
N : Type u_3
inst✝¹ : AddCommGroup N
inst✝ : Module R N
f : M →ₗ[R] N
h : Function.Surjective ⇑((I • ⊤).mkQ ∘ₗ f)
y : AdicCompletion I N
⊢ Submodule.Quotient.mk (f 0) = (eval I N 0) y

Tactic:
apply_fun (Submodule.Quotient.equiv (I ^ 0 • ⊤) ⊤ (.refl R N) (by simp)).toEquiv

Goal state after:
case property
R : Type u_1
inst✝⁴ : CommRing R
I : Ideal R
M : Type u_2
inst✝³ : AddCommGroup M
inst✝² : Module R M
N : Type u_3
inst✝¹ : AddCommGroup N
inst✝ : Module R N
f : M →ₗ[R] N
h : Function.Surjective ⇑((I • ⊤).mkQ ∘ₗ f)
y : AdicCompletion I N
⊢ (Quotient.equiv (I ^ 0 • ⊤) ⊤ (LinearEquiv.refl R N) ⋯).toEquiv (Submodule.Quotient.mk (f 0)) =
    (Quotient.equiv (I ^ 0 • ⊤) ⊤ (LinearEquiv.refl R N) ⋯).toEquiv ((eval I N 0) y)
Module: Mathlib.RingTheory.Extension.Presentation.Submersive

Goal state before:
pp: case intro
R : Type u
S : Type v
ι : Type w
σ : Type t
inst✝³ : CommRing R
inst✝² : CommRing S
inst✝¹ : Algebra R S
P : PreSubmersivePresentation R S ι σ
inst✝ : Finite σ
val✝ : Fintype σ
⊢ P.jacobian = LinearMap.det P.aevalDifferential

Tactic:
simp [← LinearMap.det_toMatrix', P.aevalDifferential_toMatrix'_eq_mapMatrix_jacobiMatrix,
    jacobian_eq_jacobiMatrix_det, RingHom.map_det, P.algebraMap_eq]

Goal state after:
Module: Mathlib.AlgebraicGeometry.EllipticCurve.Projective.Formula

Goal state before:
pp: R : Type r
inst✝ : CommRing R
W' : Projective R
P Q : Fin 3 → R
u v : R
⊢ W'.addZ (u • P) (v • Q) = (u * v) ^ 2 * W'.addZ P Q

Tactic:
by
  simp only [addZ, smul_fin3_ext]
  ring1

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
x : ((localizationAway T g).comp P).toExtension.Cotangent
hx : (Extension.Cotangent.map ((localizationAway T g).ofComp P).toExtensionHom) x = cMulXSubOneCotangent T g
⊢ Extension.Cotangent.map ((localizationAway T g).ofComp P).toExtensionHom ∘ₗ cotangentCompAwaySec g P x = LinearMap.id

Tactic:
refine (basisCotangentAway T g).ext fun r ↦ ?_
  simpa only [LinearMap.coe_comp, Function.comp_apply, basisCotangentAway_apply,
    cotangentCompAwaySec_apply]

Goal state after:
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
⊢ J ≤ P.ker

Tactic:
simp [J, Ideal.span_le, Set.range_subset_iff]

Goal state after:
Module: Mathlib.AlgebraicGeometry.EllipticCurve.Projective.Formula

Goal state before:
pp: F : Type u
inst✝¹ : Field F
W : Projective F
inst✝ : DecidableEq F
P Q : Fin 3 → F
hP : W.Equation P
hQ : W.Equation Q
hPz : P z ≠ 0
hQz : Q z ≠ 0
hx : P x * Q z ≠ Q x * P z
⊢ W.negAddY P Q / W.addZ P Q =
    W.toAffine.negAddY (P x / P z) (Q x / Q z) (P y / P z)
      (W.toAffine.slope (P x / P z) (Q x / Q z) (P y / P z) (Q y / Q z))

Tactic:
by
  rw [negAddY_eq hP hQ hPz hQz, addZ_eq hP hQ hPz hQz, toAffine_slope_of_ne hPz hQz hx,
    toAffine_negAddY_of_ne hPz hQz <| sub_ne_zero.mpr hx]

Goal state after:
Module: Mathlib.AlgebraicGeometry.EllipticCurve.Projective.Formula

Goal state before:
pp: R : Type r
inst✝ : CommRing R
W' : Projective R
P : Fin 3 → R
⊢ ![0, W'.addY P P, W'.addZ P P] = ![0, 0, 0]

Tactic:
addY_self,

Goal state after:
R : Type r
inst✝ : CommRing R
W' : Projective R
P : Fin 3 → R
⊢ ![0, 0, W'.addZ P P] = ![0, 0, 0]
Module: Mathlib.AlgebraicGeometry.Morphisms.FormallyUnramified

Goal state before:
pp: X Y : Scheme
f : X ⟶ Y
inst✝¹ : FormallyUnramified f
inst✝ : LocallyOfFiniteType f
x : ↥X
algInst✝ : Algebra ↑(Y.presheaf.stalk (f x)) ↑(X.presheaf.stalk x) :=
  (CommRingCat.Hom.hom (Scheme.Hom.stalkMap f x)).toAlgebra
this✝ : IsLocalHom (algebraMap ↑(Y.presheaf.stalk (f x)) ↑(X.presheaf.stalk x))
this : Algebra.EssFiniteType ↑(Y.presheaf.stalk (f x)) ↑(X.presheaf.stalk x)
⊢ (CommRingCat.Hom.hom (Scheme.Hom.stalkMap f x)).FormallyUnramified

Tactic:
exact stalkMap f x

Goal state after:
Module: Mathlib.CategoryTheory.MorphismProperty.Descent

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
P Q : MorphismProperty C
inst✝ : P.RespectsIso
H : ∀ {X Y Z : C} {f : X ⟶ Z} {g : Y ⟶ Z} [inst : HasPullback f g], Q f → P (pullback.fst f g) → P g
A X Y Z : C
fst : A ⟶ X
snd : A ⟶ Y
f : X ⟶ Z
g : Y ⟶ Z
h : IsPullback fst snd f g
hf : Q f
hfst : P fst
this : HasPullback f g
⊢ P (pullback.fst f g)

Tactic:
← P.cancel_left_of_respectsIso h.isoPullback.hom,

Goal state after:
C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
P Q : MorphismProperty C
inst✝ : P.RespectsIso
H : ∀ {X Y Z : C} {f : X ⟶ Z} {g : Y ⟶ Z} [inst : HasPullback f g], Q f → P (pullback.fst f g) → P g
A X Y Z : C
fst : A ⟶ X
snd : A ⟶ Y
f : X ⟶ Z
g : Y ⟶ Z
h : IsPullback fst snd f g
hf : Q f
hfst : P fst
this : HasPullback f g
⊢ P (h.isoPullback.hom ≫ pullback.fst f g)
Module: Mathlib.RingTheory.IntegralClosure.IsIntegral.AlmostIntegral

Goal state before:
pp: case h.inr
R : Type u_1
S : Type u_2
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
s : S
H : IsIntegral R s
h : ∃ t ∈ R⁰, t • s ∈ (algebraMap R S).range
b : R
hb' : b ∈ R⁰
hb : ∀ i < (minpoly R s).natDegree, b • s ^ i ∈ (algebraMap R S).range
n : ℕ
IH : ∀ m < n, b • s ^ m ∈ (algebraMap R S).range
hn : (minpoly R s).natDegree ≤ n
this : s ^ (minpoly R s).natDegree = -∑ x ∈ Finset.range (minpoly R s).natDegree, (minpoly R s).coeff x • s ^ x
⊢ b • s ^ n ∈ (algebraMap R S).range

Tactic:
← Nat.sub_add_cancel hn,

Goal state after:
case h.inr
R : Type u_1
S : Type u_2
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
s : S
H : IsIntegral R s
h : ∃ t ∈ R⁰, t • s ∈ (algebraMap R S).range
b : R
hb' : b ∈ R⁰
hb : ∀ i < (minpoly R s).natDegree, b • s ^ i ∈ (algebraMap R S).range
n : ℕ
IH : ∀ m < n, b • s ^ m ∈ (algebraMap R S).range
hn : (minpoly R s).natDegree ≤ n
this : s ^ (minpoly R s).natDegree = -∑ x ∈ Finset.range (minpoly R s).natDegree, (minpoly R s).coeff x • s ^ x
⊢ b • s ^ (n - (minpoly R s).natDegree + (minpoly R s).natDegree) ∈ (algebraMap R S).range
Module: Mathlib.RingTheory.IntegralClosure.IsIntegral.AlmostIntegral

Goal state before:
pp: case h.inr
R : Type u_1
S : Type u_2
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
s : S
H : IsIntegral R s
h : ∃ t ∈ R⁰, t • s ∈ (algebraMap R S).range
b : R
hb' : b ∈ R⁰
hb : ∀ i < (minpoly R s).natDegree, b • s ^ i ∈ (algebraMap R S).range
n : ℕ
IH : ∀ m < n, b • s ^ m ∈ (algebraMap R S).range
hn : (minpoly R s).natDegree ≤ n
this : s ^ (minpoly R s).natDegree = -∑ x ∈ Finset.range (minpoly R s).natDegree, (minpoly R s).coeff x • s ^ x
⊢ b • (s ^ (n - (minpoly R s).natDegree) * -∑ x ∈ Finset.range (minpoly R s).natDegree, (minpoly R s).coeff x • s ^ x) ∈
    (algebraMap R S).range

Tactic:
mul_neg,

Goal state after:
case h.inr
R : Type u_1
S : Type u_2
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
s : S
H : IsIntegral R s
h : ∃ t ∈ R⁰, t • s ∈ (algebraMap R S).range
b : R
hb' : b ∈ R⁰
hb : ∀ i < (minpoly R s).natDegree, b • s ^ i ∈ (algebraMap R S).range
n : ℕ
IH : ∀ m < n, b • s ^ m ∈ (algebraMap R S).range
hn : (minpoly R s).natDegree ≤ n
this : s ^ (minpoly R s).natDegree = -∑ x ∈ Finset.range (minpoly R s).natDegree, (minpoly R s).coeff x • s ^ x
⊢ b • -(s ^ (n - (minpoly R s).natDegree) * ∑ x ∈ Finset.range (minpoly R s).natDegree, (minpoly R s).coeff x • s ^ x) ∈
    (algebraMap R S).range
Module: Mathlib.RingTheory.IntegralClosure.IsIntegral.AlmostIntegral

Goal state before:
pp: case h.inr
R : Type u_1
S : Type u_2
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
s : S
H : IsIntegral R s
h : ∃ t ∈ R⁰, t • s ∈ (algebraMap R S).range
b : R
hb' : b ∈ R⁰
hb : ∀ i < (minpoly R s).natDegree, b • s ^ i ∈ (algebraMap R S).range
n : ℕ
IH : ∀ m < n, b • s ^ m ∈ (algebraMap R S).range
hn : (minpoly R s).natDegree ≤ n
this : s ^ (minpoly R s).natDegree = -∑ x ∈ Finset.range (minpoly R s).natDegree, (minpoly R s).coeff x • s ^ x
⊢ -(b • ∑ i ∈ Finset.range (minpoly R s).natDegree, s ^ (n - (minpoly R s).natDegree) * (minpoly R s).coeff i • s ^ i) ∈
    (algebraMap R S).range

Tactic:
Finset.smul_sum

Goal state after:
case h.inr
R : Type u_1
S : Type u_2
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
s : S
H : IsIntegral R s
h : ∃ t ∈ R⁰, t • s ∈ (algebraMap R S).range
b : R
hb' : b ∈ R⁰
hb : ∀ i < (minpoly R s).natDegree, b • s ^ i ∈ (algebraMap R S).range
n : ℕ
IH : ∀ m < n, b • s ^ m ∈ (algebraMap R S).range
hn : (minpoly R s).natDegree ≤ n
this : s ^ (minpoly R s).natDegree = -∑ x ∈ Finset.range (minpoly R s).natDegree, (minpoly R s).coeff x • s ^ x
⊢ -∑ x ∈ Finset.range (minpoly R s).natDegree, b • (s ^ (n - (minpoly R s).natDegree) * (minpoly R s).coeff x • s ^ x) ∈
    (algebraMap R S).range
Module: Mathlib.RingTheory.Valuation.IsTrivialOn

Goal state before:
pp: Γ : Type u_1
inst✝³ : LinearOrderedCommGroupWithZero Γ
A : Type u_2
inst✝² : CommSemiring A
B : Type u_3
inst✝¹ : Ring B
inst✝ : Algebra A B
v : Valuation B Γ
hv : Valuation.IsTrivialOn A v
w : B
n : ℕ
a : A
ha : a ≠ 0
⊢ v ((aeval w) ((monomial n) a)) = v w ^ n

Tactic:
simp [← C_mul_X_pow_eq_monomial, map_mul, map_pow, one_mul, hv.eq_one a ha]

Goal state after:
Module: Mathlib.RingTheory.Polynomial.IsIntegral

Goal state before:
pp: R : Type u_4
A : Type u_5
inst✝² : CommRing R
inst✝¹ : CommRing A
inst✝ : Algebra R A
x : A
p : A[X]
monic : p.Monic
deg : p.natDegree ≠ 0
hx : IsIntegral R (eval x p)
hp : ∀ (i : ℕ), IsIntegral R (p.coeff i)
⊢ IsIntegral R x

Tactic:
obtain ⟨q, hqp, hdeg, hq⟩ :=
    lifts_and_natDegree_eq_and_monic (p := p) (f := algebraMap (integralClosure R A) _)
    (p.lifts_iff_coeff_lifts.mpr (by simpa)) monic
  exact isIntegral_trans _ (.of_aeval_monic hq (hdeg ▸ deg)
    (by simpa [← eval_map_algebraMap, hqp] using hx.tower_top))

Goal state after: