mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Analysis.Normed.Group.Ultra

Goal state before:
pp: M : Type u_1
ι : Type u_2
inst✝¹ : SeminormedCommGroup M
inst✝ : IsUltrametricDist M
s : Finset ι
f : ι → M
⊢ ‖∏ i ∈ s, f i‖₊ ≤ s.sup fun x ↦ ‖f x‖₊

Tactic:
rcases s.eq_empty_or_nonempty with rfl | hs

Goal state after:
case inl
M : Type u_1
ι : Type u_2
inst✝¹ : SeminormedCommGroup M
inst✝ : IsUltrametricDist M
f : ι → M
⊢ ‖∏ i ∈ ∅, f i‖₊ ≤ ∅.sup fun x ↦ ‖f x‖₊

case inr
M : Type u_1
ι : Type u_2
inst✝¹ : SeminormedCommGroup M
inst✝ : IsUltrametricDist M
s : Finset ι
f : ι → M
hs : s.Nonempty
⊢ ‖∏ i ∈ s, f i‖₊ ≤ s.sup fun x ↦ ‖f x‖₊
Module: Mathlib.Analysis.Normed.Group.Ultra

Goal state before:
pp: case pos
M : Type u_1
ι : Type u_2
inst✝¹ : SeminormedCommGroup M
inst✝ : IsUltrametricDist M
f : ι → M
hι : Nonempty ι
h : Multipliable f
⊢ ‖∏' (i : ι), f i‖ ≤ ⨆ i, ‖f i‖

pp: case neg
M : Type u_1
ι : Type u_2
inst✝¹ : SeminormedCommGroup M
inst✝ : IsUltrametricDist M
f : ι → M
hι : Nonempty ι
h : ¬Multipliable f
⊢ ‖∏' (i : ι), f i‖ ≤ ⨆ i, ‖f i‖

Tactic:
swap

Goal state after:
case neg
M : Type u_1
ι : Type u_2
inst✝¹ : SeminormedCommGroup M
inst✝ : IsUltrametricDist M
f : ι → M
hι : Nonempty ι
h : ¬Multipliable f
⊢ ‖∏' (i : ι), f i‖ ≤ ⨆ i, ‖f i‖

case pos
M : Type u_1
ι : Type u_2
inst✝¹ : SeminormedCommGroup M
inst✝ : IsUltrametricDist M
f : ι → M
hι : Nonempty ι
h : Multipliable f
⊢ ‖∏' (i : ι), f i‖ ≤ ⨆ i, ‖f i‖
Module: Mathlib.Analysis.Normed.Group.Ultra

Goal state before:
pp: case cons
M : Type u_1
ι : Type u_2
inst✝¹ : SeminormedCommGroup M
inst✝ : IsUltrametricDist M
f : ι → M
a : ι
s : Finset ι
ha : a ∉ s
IH : ((↑s).Pairwise fun i j ↦ ‖f i‖₊ ≠ ‖f j‖₊) → ‖∏ i ∈ s, f i‖₊ = s.sup fun i ↦ ‖f i‖₊
hs : (↑(Finset.cons a s ha)).Pairwise fun i j ↦ ‖f i‖₊ ≠ ‖f j‖₊
⊢ ‖∏ i ∈ Finset.cons a s ha, f i‖₊ = (Finset.cons a s ha).sup fun i ↦ ‖f i‖₊

Tactic:
rcases s.eq_empty_or_nonempty with rfl | hs'

Goal state after:
case cons.inl
M : Type u_1
ι : Type u_2
inst✝¹ : SeminormedCommGroup M
inst✝ : IsUltrametricDist M
f : ι → M
a : ι
ha : a ∉ ∅
IH : ((↑∅).Pairwise fun i j ↦ ‖f i‖₊ ≠ ‖f j‖₊) → ‖∏ i ∈ ∅, f i‖₊ = ∅.sup fun i ↦ ‖f i‖₊
hs : (↑(Finset.cons a ∅ ha)).Pairwise fun i j ↦ ‖f i‖₊ ≠ ‖f j‖₊
⊢ ‖∏ i ∈ Finset.cons a ∅ ha, f i‖₊ = (Finset.cons a ∅ ha).sup fun i ↦ ‖f i‖₊

case cons.inr
M : Type u_1
ι : Type u_2
inst✝¹ : SeminormedCommGroup M
inst✝ : IsUltrametricDist M
f : ι → M
a : ι
s : Finset ι
ha : a ∉ s
IH : ((↑s).Pairwise fun i j ↦ ‖f i‖₊ ≠ ‖f j‖₊) → ‖∏ i ∈ s, f i‖₊ = s.sup fun i ↦ ‖f i‖₊
hs : (↑(Finset.cons a s ha)).Pairwise fun i j ↦ ‖f i‖₊ ≠ ‖f j‖₊
hs' : s.Nonempty
⊢ ‖∏ i ∈ Finset.cons a s ha, f i‖₊ = (Finset.cons a s ha).sup fun i ↦ ‖f i‖₊
Module: Mathlib.RingTheory.MvPowerSeries.Inverse

Goal state before:
pp: σ : Type u_1
R : Type u_2
inst✝ : Ring R
φ : MvPowerSeries σ R
u : Rˣ
h : constantCoeff φ = ↑u
n : σ →₀ ℕ
this : DecidableEq (σ →₀ ℕ) := Classical.decEq (σ →₀ ℕ)
H : n = 0
⊢ (coeff 0) (φ * φ.invOfUnit u) = (coeff 0) 1

Tactic:
simp [h]

Goal state after:
Module: Mathlib.AlgebraicGeometry.EllipticCurve.ModelsWithJ

Goal state before:
pp: case neg
R : Type u_1
inst✝³ : CommRing R
W : WeierstrassCurve R
j✝ : R
inst✝² : W.IsElliptic
F : Type u_2
inst✝¹ : Field F
j : F
inst✝ : DecidableEq F
h0 : ¬j = 0
h1728 : ¬j = 1728
⊢ (ofJ j).IsElliptic

Tactic:
have := Fact.mk (Ne.isUnit h0)
      have := Fact.mk (sub_ne_zero.2 h1728).isUnit
      rw [ofJ_ne_0_ne_1728 j h0 h1728]
      infer_instance

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

Goal state before:
pp: R : Type r
inst✝ : CommRing R
W' : Projective R
P Q : Fin 3 → R
u v : R
hu : IsUnit u
hv : IsUnit v
⊢ W'.add (u • P) (v • Q) ≈ W'.add P Q

Tactic:
by_cases h : P ≈ Q

Goal state after:
case pos
R : Type r
inst✝ : CommRing R
W' : Projective R
P Q : Fin 3 → R
u v : R
hu : IsUnit u
hv : IsUnit v
h : P ≈ Q
⊢ W'.add (u • P) (v • Q) ≈ W'.add P Q

case neg
R : Type r
inst✝ : CommRing R
W' : Projective R
P Q : Fin 3 → R
u v : R
hu : IsUnit u
hv : IsUnit v
h : ¬P ≈ Q
⊢ W'.add (u • P) (v • Q) ≈ W'.add P Q
Module: Mathlib.AlgebraicGeometry.EllipticCurve.Projective.Basic

Goal state before:
pp: R : Type r
inst✝ : CommRing R
W' : Projective R
P : Fin 3 → R
⊢ W'.Nonsingular P ↔
    W'.Equation P ∧
      (W'.a₁ * P y * P z - (3 * P x ^ 2 + 2 * W'.a₂ * P x * P z + W'.a₄ * P z ^ 2) ≠ 0 ∨
        2 * P y * P z + W'.a₁ * P x * P z + W'.a₃ * P z ^ 2 ≠ 0 ∨
          P y ^ 2 + W'.a₁ * P x * P y + 2 * W'.a₃ * P y * P z -
              (W'.a₂ * P x ^ 2 + 2 * W'.a₄ * P x * P z + 3 * W'.a₆ * P z ^ 2) ≠
            0)

Tactic:
Nonsingular,

Goal state after:
R : Type r
inst✝ : CommRing R
W' : Projective R
P : Fin 3 → R
⊢ W'.Equation P ∧ ((eval P) W'.polynomialX ≠ 0 ∨ (eval P) W'.polynomialY ≠ 0 ∨ (eval P) W'.polynomialZ ≠ 0) ↔
    W'.Equation P ∧
      (W'.a₁ * P y * P z - (3 * P x ^ 2 + 2 * W'.a₂ * P x * P z + W'.a₄ * P z ^ 2) ≠ 0 ∨
        2 * P y * P z + W'.a₁ * P x * P z + W'.a₃ * P z ^ 2 ≠ 0 ∨
          P y ^ 2 + W'.a₁ * P x * P y + 2 * W'.a₃ * P y * P z -
              (W'.a₂ * P x ^ 2 + 2 * W'.a₄ * P x * P z + 3 * W'.a₆ * P z ^ 2) ≠
            0)
Module: Mathlib.AlgebraicGeometry.EllipticCurve.Projective.Basic

Goal state before:
pp: case refine_1
F : Type u
inst✝¹ : Field F
W : Projective F
K : Type v
inst✝ : Field K
f : F →+* K
P Q : Fin 3 → F
hP : W.Nonsingular P
hQ : W.Nonsingular Q
h : ⇑f ∘ P ≈ ⇑f ∘ Q
⊢ P ≈ Q

Tactic:
by_cases hz : f (P z) = 0

Goal state after:
case pos
F : Type u
inst✝¹ : Field F
W : Projective F
K : Type v
inst✝ : Field K
f : F →+* K
P Q : Fin 3 → F
hP : W.Nonsingular P
hQ : W.Nonsingular Q
h : ⇑f ∘ P ≈ ⇑f ∘ Q
hz : f (P z) = 0
⊢ P ≈ Q

case neg
F : Type u
inst✝¹ : Field F
W : Projective F
K : Type v
inst✝ : Field K
f : F →+* K
P Q : Fin 3 → F
hP : W.Nonsingular P
hQ : W.Nonsingular Q
h : ⇑f ∘ P ≈ ⇑f ∘ Q
hz : ¬f (P z) = 0
⊢ P ≈ Q
Module: Mathlib.AlgebraicGeometry.EllipticCurve.Projective.Point

Goal state before:
pp: F : Type u
K : Type v
inst✝¹ : Field F
inst✝ : Field K
W : Projective F
f : F →+* K
P Q : Fin 3 → F
hP : W.Nonsingular P
hQ : W.Nonsingular Q
⊢ (W.map f).add (⇑f ∘ P) (⇑f ∘ Q) = ⇑f ∘ W.add P Q

Tactic:
by_cases h : P ≈ Q

Goal state after:
case pos
F : Type u
K : Type v
inst✝¹ : Field F
inst✝ : Field K
W : Projective F
f : F →+* K
P Q : Fin 3 → F
hP : W.Nonsingular P
hQ : W.Nonsingular Q
h : P ≈ Q
⊢ (W.map f).add (⇑f ∘ P) (⇑f ∘ Q) = ⇑f ∘ W.add P Q

case neg
F : Type u
K : Type v
inst✝¹ : Field F
inst✝ : Field K
W : Projective F
f : F →+* K
P Q : Fin 3 → F
hP : W.Nonsingular P
hQ : W.Nonsingular Q
h : ¬P ≈ Q
⊢ (W.map f).add (⇑f ∘ P) (⇑f ∘ Q) = ⇑f ∘ W.add P Q
Module: Mathlib.RingTheory.Smooth.Pi

Goal state before:
pp: case g.map_one
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✝ : FormallySmooth R ((i : I) → A i)
i : I
⊢ ((Ideal.Quotient.mkₐ R (RingHom.ker (Pi.evalAlgHom R A i).toRingHom ^ 2)).toLinearMap ∘ₗ LinearMap.single R A i) 1 = 1

pp: case g.map_mul
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✝ : FormallySmooth R ((i : I) → A i)
i : I
⊢ ∀ (x y : A i),
    ((Ideal.Quotient.mkₐ R (RingHom.ker (Pi.evalAlgHom R A i).toRingHom ^ 2)).toLinearMap ∘ₗ LinearMap.single R A i)
        (x * y) =
      ((Ideal.Quotient.mkₐ R (RingHom.ker (Pi.evalAlgHom R A i).toRingHom ^ 2)).toLinearMap ∘ₗ LinearMap.single R A i)
          x *
        ((Ideal.Quotient.mkₐ R (RingHom.ker (Pi.evalAlgHom R A i).toRingHom ^ 2)).toLinearMap ∘ₗ LinearMap.single R A i)
          y

Tactic:
· change Ideal.Quotient.mk _ (Pi.single i 1) = 1
      rw [← (Ideal.Quotient.mk _).map_one, ← sub_eq_zero, ← map_sub,
        Ideal.Quotient.eq_zero_iff_mem]
      have : Pi.single i 1 - 1 ∈ RingHom.ker (Pi.evalAlgHom R A i).toRingHom := by
        simp [RingHom.mem_ker]
      convert! neg_mem (Ideal.pow_mem_pow this 2) using 1
      simp [pow_two, sub_mul, mul_sub, ← Pi.single_mul]

Goal state after:
case g.map_mul
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✝ : FormallySmooth R ((i : I) → A i)
i : I
⊢ ∀ (x y : A i),
    ((Ideal.Quotient.mkₐ R (RingHom.ker (Pi.evalAlgHom R A i).toRingHom ^ 2)).toLinearMap ∘ₗ LinearMap.single R A i)
        (x * y) =
      ((Ideal.Quotient.mkₐ R (RingHom.ker (Pi.evalAlgHom R A i).toRingHom ^ 2)).toLinearMap ∘ₗ LinearMap.single R A i)
          x *
        ((Ideal.Quotient.mkₐ R (RingHom.ker (Pi.evalAlgHom R A i).toRingHom ^ 2)).toLinearMap ∘ₗ LinearMap.single R A i)
          y
Module: Mathlib.RingTheory.Unramified.Pi

Goal state before:
pp: case intro.mpr
R : Type u_1
I : Type u_2
inst✝³ : Finite I
f : I → Type u_3
inst✝² : CommRing R
inst✝¹ : (i : I) → CommRing (f i)
inst✝ : (i : I) → Algebra R (f i)
val✝ : Fintype I
H : ∀ (i : I), FormallyUnramified R (f i)
⊢ ∀ ⦃B : Type (max u_2 u_3)⦄ [inst : CommRing B] [inst_1 : Algebra R B] (I_1 : Ideal B),
    I_1 ^ 2 = ⊥ → Function.Injective (Ideal.Quotient.mkₐ R I_1).comp

Tactic:
intro B

Goal state after:
case intro.mpr
R : Type u_1
I : Type u_2
inst✝³ : Finite I
f : I → Type u_3
inst✝² : CommRing R
inst✝¹ : (i : I) → CommRing (f i)
inst✝ : (i : I) → Algebra R (f i)
val✝ : Fintype I
H : ∀ (i : I), FormallyUnramified R (f i)
B : Type (max u_2 u_3)
⊢ ∀ [inst : CommRing B] [inst_1 : Algebra R B] (I_1 : Ideal B),
    I_1 ^ 2 = ⊥ → Function.Injective (Ideal.Quotient.mkₐ R I_1).comp
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
x : B ⧸ J
hix : (ι i) x = 0
⊢ x ∈ Ideal.map (Ideal.Quotient.mk J) (Ideal.span {1 - e i})

Tactic:
rw [← Ideal.ker_quotientMap_mk]

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
x : B ⧸ J
hix : (ι i) x = 0
⊢ x ∈
    RingHom.ker
      (Ideal.quotientMap (Ideal.map (Ideal.Quotient.mk (Ideal.span {1 - e i})) J)
        (Ideal.Quotient.mk (Ideal.span {1 - e i})) ⋯)
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}
⊢ f x →ₐ[R] B ⧸ J'

Tactic:
apply AlgHom.ofLinearMap
        (((Ideal.Quotient.mkₐ R J').comp f₁).toLinearMap.comp (LinearMap.single _ _ x))

Goal state after:
case map_one
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 := ⋯
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.Quotient.mkₐ R J').comp f₁).toLinearMap ∘ₗ LinearMap.single R f x) 1 = 1

case map_mul
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 := ⋯
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 := ⋯
⊢ ∀ (x_1 y : f x),
    (((Ideal.Quotient.mkₐ R J').comp f₁).toLinearMap ∘ₗ LinearMap.single R f x) (x_1 * y) =
      (((Ideal.Quotient.mkₐ R J').comp f₁).toLinearMap ∘ₗ LinearMap.single R f x) x_1 *
        (((Ideal.Quotient.mkₐ R J').comp f₁).toLinearMap ∘ₗ LinearMap.single R f x) y
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 (Pi.single x (g x)) - f₂ (Pi.single x (g x)) = (1 - f₁ e) * c
⊢ f₁ (Pi.single x (g x)) = f₂ (Pi.single x (g x))

Tactic:
apply_fun (f₁ e * ·) at hc

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)) - f₂ (Pi.single x (g x))) = f₁ e * ((1 - 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 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
⊢ (aeval (x + u * (aeval x) (minpoly K pb.gen))) (minpoly K pb.gen) = 0

Tactic:
rw [← eval_map_algebraMap, Polynomial.eval_add_of_sq_eq_zero, derivative_map,
      ← one_mul (eval x _), eval_map_algebraMap, eval_map_algebraMap, ← mul_assoc, ← add_mul,
      ← Ideal.mem_bot, ← h, pow_two, add_comm]

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
⊢ ((aeval x) (derivative (minpoly K pb.gen)) * u + 1) * (aeval x) (minpoly K pb.gen) ∈ I * I

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: K : Type u_1
A : Type u
inst✝⁹ : Field K
inst✝⁸ : CommRing A
inst✝⁷ : Algebra K A
B : Type u_3
inst✝⁶ : CommRing B
inst✝⁵ : EssFiniteType K A
inst✝⁴ : FormallyEtale K A
inst✝³ : Algebra K B
inst✝² : EssFiniteType K B
inst✝¹ : FormallyEtale K B
inst✝ : IsSepClosed K
f : A →ₐ[K] B
x : A
p : PrimeSpectrum B
heq : ofId K (B ⧸ p.asIdeal) = (Ideal.quotientMapₐ p.asIdeal f ⋯).comp (ofId K (A ⧸ Ideal.comap f p.asIdeal))
h :
  (Ideal.quotientMapₐ p.asIdeal f ⋯) ((Ideal.Quotient.mk (Ideal.comap f p.asIdeal)) x) =
    (Ideal.Quotient.mk p.asIdeal) (f x)
⊢ ((Ideal.quotientMapₐ p.asIdeal f ⋯).comp (ofId K (A ⧸ Ideal.comap f p.asIdeal)))
      ((AlgEquiv.ofBijective (ofId K (A ⧸ Ideal.comap (↑f) p.asIdeal)) ⋯).symm
        ((Ideal.Quotient.mk (Ideal.comap (↑f) p.asIdeal)) x)) =
    (ofId K (B ⧸ p.asIdeal))
      ((AlgEquiv.ofBijective (ofId K (B ⧸ p.asIdeal)) ⋯).symm ((Ideal.Quotient.mk p.asIdeal) (f x)))

Tactic:
simp only [AlgHom.coe_comp, Function.comp_apply, AlgEquiv.ofBijective_apply_symm_apply]

Goal state after:
K : Type u_1
A : Type u
inst✝⁹ : Field K
inst✝⁸ : CommRing A
inst✝⁷ : Algebra K A
B : Type u_3
inst✝⁶ : CommRing B
inst✝⁵ : EssFiniteType K A
inst✝⁴ : FormallyEtale K A
inst✝³ : Algebra K B
inst✝² : EssFiniteType K B
inst✝¹ : FormallyEtale K B
inst✝ : IsSepClosed K
f : A →ₐ[K] B
x : A
p : PrimeSpectrum B
heq : ofId K (B ⧸ p.asIdeal) = (Ideal.quotientMapₐ p.asIdeal f ⋯).comp (ofId K (A ⧸ Ideal.comap f p.asIdeal))
h :
  (Ideal.quotientMapₐ p.asIdeal f ⋯) ((Ideal.Quotient.mk (Ideal.comap f p.asIdeal)) x) =
    (Ideal.Quotient.mk p.asIdeal) (f x)
⊢ (Ideal.quotientMapₐ p.asIdeal f ⋯)
      ((ofId K (A ⧸ Ideal.comap f p.asIdeal))
        ((AlgEquiv.ofBijective (ofId K (A ⧸ Ideal.comap (↑f) p.asIdeal)) ⋯).symm
          ((Ideal.Quotient.mk (Ideal.comap (↑f) p.asIdeal)) x))) =
    (Ideal.Quotient.mk p.asIdeal) (f x)
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
z m✝ : A
⊢ (⋯.lift ((mk R S Ω[A⁄R]) 1 ∘ₗ ↑(D R A))) ((algebraMap A B) z * (IsScalarTower.toAlgHom R A B).toLinearMap m✝) =
    (algebraMap A B) z • (⋯.lift ((mk R S Ω[A⁄R]) 1 ∘ₗ ↑(D R A))) ((IsScalarTower.toAlgHom R A B).toLinearMap m✝) +
      (IsScalarTower.toAlgHom R A B).toLinearMap m✝ • (⋯.lift ((mk R S Ω[A⁄R]) 1 ∘ₗ ↑(D R A))) ((algebraMap A B) z)

Tactic:
| tmul =>

Goal state after: