mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.FieldTheory.SeparablyGenerated

Goal state before:
pp: k : Type u_1
K : Type u_2
ι : Type u_3
inst✝² : Field k
inst✝¹ : Field K
inst✝ : Algebra k K
p : ℕ
hp : Nat.Prime p
a : ι → K
F : MvPolynomial ι k
HF : ∀ (F' : MvPolynomial ι k), F' ≠ 0 → (aeval a) F' = 0 → F.totalDegree ≤ F'.totalDegree
hF0 : F ≠ 0
hFa : (aeval a) F = 0
this : ∀ (i : ι), ∀ σ ∈ F.support, p ∣ σ i
σ' : (ι →₀ ℕ) → ι →₀ ℕ
hσ' : ∀ σ ∈ F.support, σ = p • σ' σ
hσ'' : ∀ (σ : ↥F.support), ↑σ = p • σ' ↑σ
H : ∀ (ι : Type u_3) (x : Fintype ι) (v : ι → K), LinearIndependent k v → LinearIndependent k fun x ↦ v x ^ p
⊢ (aeval a) (∑ x ∈ F.support.attach, (monomial ↑x) (coeff (↑x) F)) = 0

Tactic:
F.support.sum_attach (fun i ↦ monomial i (F.coeff i)),

Goal state after:
k : Type u_1
K : Type u_2
ι : Type u_3
inst✝² : Field k
inst✝¹ : Field K
inst✝ : Algebra k K
p : ℕ
hp : Nat.Prime p
a : ι → K
F : MvPolynomial ι k
HF : ∀ (F' : MvPolynomial ι k), F' ≠ 0 → (aeval a) F' = 0 → F.totalDegree ≤ F'.totalDegree
hF0 : F ≠ 0
hFa : (aeval a) F = 0
this : ∀ (i : ι), ∀ σ ∈ F.support, p ∣ σ i
σ' : (ι →₀ ℕ) → ι →₀ ℕ
hσ' : ∀ σ ∈ F.support, σ = p • σ' σ
hσ'' : ∀ (σ : ↥F.support), ↑σ = p • σ' ↑σ
H : ∀ (ι : Type u_3) (x : Fintype ι) (v : ι → K), LinearIndependent k v → LinearIndependent k fun x ↦ v x ^ p
⊢ (aeval a) (∑ x ∈ F.support, (monomial x) (coeff x F)) = 0
Module: Mathlib.FieldTheory.SeparablyGenerated

Goal state before:
pp: k : Type u_1
K : Type u_2
ι : Type u_3
inst✝² : Field k
inst✝¹ : Field K
inst✝ : Algebra k K
p : ℕ
hp : Nat.Prime p
a : ι → K
F : MvPolynomial ι k
HF : ∀ (F' : MvPolynomial ι k), F' ≠ 0 → (aeval a) F' = 0 → F.totalDegree ≤ F'.totalDegree
hF0 : F ≠ 0
hFa : (aeval a) F = 0
this : ∀ (i : ι), ∀ σ ∈ F.support, p ∣ σ i
σ' : (ι →₀ ℕ) → ι →₀ ℕ
hσ' : ∀ σ ∈ F.support, σ = p • σ' σ
hσ'' : ∀ (σ : ↥F.support), ↑σ = p • σ' ↑σ
H : ∀ (ι : Type u_3) (x : Fintype ι) (v : ι → K), LinearIndependent k v → LinearIndependent k fun x ↦ v x ^ p
F' : ↥F.support →₀ k
hF' : (Finsupp.linearCombination k fun s ↦ (aeval a) ((monomial (σ' ↑s)) 1)) F' = 0
hF'0 : ¬F' = 0
F'' : MvPolynomial ι k := AddMonoidAlgebra.ofCoeff (Finsupp.mapDomain (fun s ↦ σ' ↑s) F')
⊢ 0 = 0

Tactic:
by simp

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

Goal state before:
pp: R : Type r
inst✝¹ : CommRing R
W' : Projective R
inst✝ : NoZeroDivisors R
P Q : Fin 3 → R
hP : W'.Equation P
hPz : P z = 0
⊢ W'.negY ![W'.addX P Q, W'.negAddY P Q, W'.addZ P Q] = P y ^ 2 * Q z * Q y

Tactic:
negY_eq,

Goal state after:
R : Type r
inst✝¹ : CommRing R
W' : Projective R
inst✝ : NoZeroDivisors R
P Q : Fin 3 → R
hP : W'.Equation P
hPz : P z = 0
⊢ -W'.negAddY P Q - W'.a₁ * W'.addX P Q - W'.a₃ * W'.addZ P Q = P y ^ 2 * Q z * Q y
Module: Mathlib.AlgebraicGeometry.Morphisms.FormallyUnramified

Goal state before:
pp: R S : Type u
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : Algebra R S
inst✝¹ : FormallyUnramified R S
inst✝ : EssFiniteType R S
x : ↑(CommRingCat.of S)
⊢ (CommRingCat.Hom.hom (CommRingCat.ofHom (TensorProduct.lmul' R).toRingHom)) (1 ⊗ₜ[R] x) = x

Tactic:
by simp

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

Goal state before:
pp: R : Type r
inst✝¹ : CommRing R
W' : Projective R
inst✝ : NoZeroDivisors R
P Q : Fin 3 → R
hQ : W'.Equation Q
hQz : Q z = 0
⊢ W'.negY ![W'.addX P Q, W'.negAddY P Q, W'.addZ P Q] = -(Q y ^ 2 * P z) * P y

Tactic:
negY_eq,

Goal state after:
R : Type r
inst✝¹ : CommRing R
W' : Projective R
inst✝ : NoZeroDivisors R
P Q : Fin 3 → R
hQ : W'.Equation Q
hQz : Q z = 0
⊢ -W'.negAddY P Q - W'.a₁ * W'.addX P Q - W'.a₃ * W'.addZ P Q = -(Q y ^ 2 * P z) * P y
Module: Mathlib.AlgebraicGeometry.Morphisms.FormallyUnramified

Goal state before:
pp: X Y : Scheme
f✝ : X ⟶ Y
R S : CommRingCat
f : Spec S ⟶ Spec R
inst✝ : IsOpenImmersion (pullback.diagonal f)
⊢ FormallyUnramified f

Tactic:
obtain ⟨φ, rfl : Spec.map φ = f⟩ := Spec.homEquiv.symm.surjective f

Goal state after:
X Y : Scheme
f : X ⟶ Y
R S : CommRingCat
φ : R ⟶ S
inst✝ : IsOpenImmersion (pullback.diagonal (Spec.map φ))
⊢ FormallyUnramified (Spec.map φ)
Module: Mathlib.AlgebraicGeometry.EllipticCurve.Projective.Formula

Goal state before:
pp: case a
R : Type r
inst✝¹ : CommRing R
W' : Projective R
inst✝ : NoZeroDivisors R
P Q : Fin 3 → R
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'.negY ![W'.addX P Q, W'.negAddY P Q, W'.addZ P Q] * (P z * Q z) ^ 3 +
        -(P z * Q z) * ((P y * Q z - Q y * P z) ^ 3 * (P z * Q z)) -
      (-(P y * Q z - Q y * P z) ^ 3 * (P z * Q z) ^ 2 + -(P z * Q z) * (W'.negAddY P Q * (P z * Q z) ^ 2)) =
    0

Tactic:
negY_eq,

Goal state after:
case a
R : Type r
inst✝¹ : CommRing R
W' : Projective R
inst✝ : NoZeroDivisors R
P Q : Fin 3 → R
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'.a₁ * W'.addX P Q - W'.a₃ * W'.addZ P Q) * (P z * Q z) ^ 3 +
        -(P z * Q z) * ((P y * Q z - Q y * P z) ^ 3 * (P z * Q z)) -
      (-(P y * Q z - Q y * P z) ^ 3 * (P z * Q z) ^ 2 + -(P z * Q z) * (W'.negAddY P Q * (P z * Q z) ^ 2)) =
    0
Module: Mathlib.AlgebraicGeometry.EllipticCurve.Projective.Formula

Goal state before:
pp: F : Type u
inst✝ : Field F
W : Projective 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.addY P Q = W.addY P Q * (P z * Q z) ^ 3 / (P z * Q z * (P z * Q z) ^ 2)

Tactic:
← pow_succ',

Goal state after:
F : Type u
inst✝ : Field F
W : Projective 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.addY P Q = W.addY P Q * (P z * Q z) ^ 3 / (P z * Q z) ^ (2 + 1)
Module: Mathlib.FieldTheory.SeparablyGenerated

Goal state before:
pp: k : Type u_1
K : Type u_2
ι : Type u_3
inst✝³ : Field k
inst✝² : Field K
inst✝¹ : Algebra k K
p : ℕ
hp : Nat.Prime p
H : ∀ (s : Finset K), LinearIndepOn k id ↑s → LinearIndepOn k (fun x ↦ x ^ p) ↑s
a : ι → K
n : ι
inst✝ : ExpChar k p
ha' : IsTranscendenceBasis k fun i ↦ a ↑i
S : Set (MvPolynomial ι k) := {F | F ≠ 0 ∧ (aeval a) F = 0}
h : AlgebraicIndependent k a
⊢ n ∉ {n}ᶜ

Tactic:
by simp

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

Goal state before:
pp: X Y : Scheme
f✝ : X ⟶ Y
S R : CommRingCat
f : R ⟶ S
inst✝¹ : (CommRingCat.Hom.hom f).FormallyUnramified
inst✝ : (CommRingCat.Hom.hom f).FiniteType
algInst✝ : Algebra ↑R ↑S := (CommRingCat.Hom.hom f).toAlgebra
algebraizeInst✝¹ : Algebra.FormallyUnramified ↑R ↑S
algebraizeInst✝ : Algebra.FiniteType ↑R ↑S
⊢ IsOpenImmersion (pullback.diagonal (Spec.map (CommRingCat.ofHom (algebraMap ↑R ↑S))))

Tactic:
diagonal_SpecMap R S,

Goal state after:
X Y : Scheme
f✝ : X ⟶ Y
S R : CommRingCat
f : R ⟶ S
inst✝¹ : (CommRingCat.Hom.hom f).FormallyUnramified
inst✝ : (CommRingCat.Hom.hom f).FiniteType
algInst✝ : Algebra ↑R ↑S := (CommRingCat.Hom.hom f).toAlgebra
algebraizeInst✝¹ : Algebra.FormallyUnramified ↑R ↑S
algebraizeInst✝ : Algebra.FiniteType ↑R ↑S
⊢ IsOpenImmersion
    (Spec.map (CommRingCat.ofHom (Algebra.TensorProduct.lmul' ↑R).toRingHom) ≫ (pullbackSpecIso ↑R ↑S ↑S).inv)
Module: Mathlib.AlgebraicGeometry.Morphisms.FormallyUnramified

Goal state before:
pp: X Y Z' Z : Scheme
i : Z' ⟶ Z
inst✝¹ : IsClosedImmersion i
f : X ⟶ Y
inst✝ : FormallyUnramified f
g₁ g₂ : Z ⟶ X
hig : i ≫ g₁ = i ≫ g₂
hgf : g₁ ≫ f = g₂ ≫ f
n : ℕ
hn : Scheme.Hom.ker i ^ n = 0
⊢ n + 1 ≠ 0

Tactic:
by simp

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

Goal state before:
pp: C : Type u_1
inst✝⁵ : Category.{v_1, u_1} C
P✝ Q✝ W : MorphismProperty C
A X✝ Y✝ Z✝ : C
fst : A ⟶ X✝
snd : A ⟶ Y✝
f✝ : X✝ ⟶ Z✝
g✝ : Y✝ ⟶ Z✝
inst✝⁴ : HasPullbacks C
P Q : MorphismProperty C
inst✝³ : P.DescendsAlong Q
inst✝² : P.RespectsIso
inst✝¹ : Q.IsStableUnderBaseChange
X Y Z : C
f : X ⟶ Z
g : Y ⟶ Z
inst✝ : HasPullback f g
hf : Q f
hfst : P.diagonal (pullback.fst f g)
⊢ pullback.diagonal g ≫ pullback.snd g g ≫ g = g

Tactic:
by simp

Goal state after:
Module: Mathlib.FieldTheory.SeparablyGenerated

Goal state before:
pp: k : Type u_1
K : Type u_2
ι : Type u_3
inst✝³ : Field k
inst✝² : Field K
inst✝¹ : Algebra k K
p : ℕ
hp : Nat.Prime p
H : ∀ (s : Finset K), LinearIndepOn k id ↑s → LinearIndepOn k (fun x ↦ x ^ p) ↑s
a : ι → K
inst✝ : ExpChar k p
s : Set ι
n : ι
ha : IsTranscendenceBasis k fun i ↦ a ↑i
hn : n ∉ s
j : ↑(insert n s)
⊢ n ∈ insert n s

Tactic:
by simp

Goal state after:
Module: Mathlib.FieldTheory.SeparablyGenerated

Goal state before:
pp: k : Type u_1
K : Type u_2
ι : Type u_3
inst✝³ : Field k
inst✝² : Field K
inst✝¹ : Algebra k K
p : ℕ
hp : Nat.Prime p
H : ∀ (s : Finset K), LinearIndepOn k id ↑s → LinearIndepOn k (fun x ↦ x ^ p) ↑s
a : ι → K
inst✝ : ExpChar k p
s : Set ι
n : ι
ha : IsTranscendenceBasis k fun i ↦ a ↑i
hn : n ∉ s
e₁ : { j // j ≠ ⟨n, ⋯⟩ } ≃ ↑s :=
  { toFun := fun x ↦ ⟨↑↑x, ⋯⟩, invFun := fun x ↦ ⟨⟨↑x, ⋯⟩, ⋯⟩, left_inv := ⋯, right_inv := ⋯ }
⊢ n ∈ insert n s

Tactic:
by simp

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

Goal state before:
pp: R : Type r
S : Type s
inst✝¹ : CommRing R
inst✝ : CommRing S
W' : Projective R
f : R →+* S
P Q : Fin 3 → R
⊢ (W'.map f).addX (⇑f ∘ P) (⇑f ∘ Q) = f (W'.addX P Q)

Tactic:
simp only [addX]
  map_simp

Goal state after:
Module: Mathlib.FieldTheory.SeparablyGenerated

Goal state before:
pp: k : Type u_1
K : Type u_2
ι : Type u_3
inst✝³ : Field k
inst✝² : Field K
inst✝¹ : Algebra k K
p : ℕ
hp : Nat.Prime p
H : ∀ (s : Finset K), LinearIndepOn k id ↑s → LinearIndepOn k (fun x ↦ x ^ p) ↑s
a : ι → K
n : ι
inst✝ : ExpChar k p
ha : adjoin k (Set.range a) = ⊤
ha' : IsTranscendenceBasis k fun i ↦ a ↑i
⊢ ∃ i, (IsTranscendenceBasis k fun j ↦ a ↑j) ∧ Algebra.IsSeparable (↥(adjoin k (a '' {i}ᶜ))) K

Tactic:
have ⟨i, hi⟩ := exists_isTranscendenceBasis_and_isSeparable_of_linearIndepOn_pow p hp H n ha'
  refine ⟨i, hi.1, ?_⟩
  rw [← separableClosure.eq_top_iff, ← (restrictScalars_injective k).eq_iff,
    restrictScalars_top, eq_top_iff, ← ha, adjoin_le_iff]
  rintro _ ⟨x, rfl⟩
  obtain rfl | ne := eq_or_ne x i
  · exact hi.2
  · exact isSeparable_algebraMap (F := adjoin k (a '' {i}ᶜ)) ⟨_, subset_adjoin _ _ ⟨x, ne, rfl⟩⟩

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

Goal state before:
pp: C : Type u_1
inst✝⁴ : Category.{v_1, u_1} C
P Q W : MorphismProperty C
A X✝ Y✝ Z : C
fst : A ⟶ X✝
snd : A ⟶ Y✝
f✝ : X✝ ⟶ Z
g✝ : Y✝ ⟶ Z
inst✝³ : (isomorphisms C).DescendsAlong P
inst✝² : P.IsStableUnderBaseChange
inst✝¹ : HasEqualizers C
inst✝ : HasPullbacks C
X Y S T : C
f g : X ⟶ Y
s : X ⟶ S
t : Y ⟶ S
hf : f ≫ t = s
hg : g ≫ t = s
v : T ⟶ S
hv : P v
⊢ v ≫ 𝟙 S = 𝟙 T ≫ v

Tactic:
by simp

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

Goal state before:
pp: R S : CommRingCat
Y : Scheme
φ : R ⟶ S
g : Y ⟶ Spec R
h : (@Surjective ⊓ @Flat) (Spec.map φ)
hfst : IsIso (pullback.fst (Spec.map φ) g)
this✝ : IsAffine Y
this :
  ∀ {Y : Scheme} (g : Y ⟶ Spec R),
    IsIso (pullback.fst (Spec.map φ) g) → IsAffine Y → (∃ T, Y = Spec T) → isomorphisms Scheme g
hY : ¬∃ T, Y = Spec T
⊢ Spec.map φ ≫ 𝟙 (Spec R) = 𝟙 (Spec S) ≫ Spec.map φ

Tactic:
by simp

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

Goal state before:
pp: R S : CommRingCat
Y : Scheme
φ : R ⟶ S
g : Y ⟶ Spec R
h : (@Surjective ⊓ @Flat) (Spec.map φ)
hfst : IsIso (pullback.fst (Spec.map φ) g)
this✝ : IsAffine Y
this :
  ∀ {Y : Scheme} (g : Y ⟶ Spec R),
    IsIso (pullback.fst (Spec.map φ) g) → IsAffine Y → (∃ T, Y = Spec T) → isomorphisms Scheme g
hY : ¬∃ T, Y = Spec T
⊢ (Y.isoSpec.inv ≫ g) ≫ 𝟙 (Spec R) = Y.isoSpec.inv ≫ g

Tactic:
by simp

Goal state after:
Module: Mathlib.RingTheory.RingHom.OpenImmersion

Goal state before:
pp: R S : Type u
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
r : R
h : IsLocalization.Away r S
⊢ (algebraMap R S).IsStandardOpenImmersion

Tactic:
exact .algebraMap r

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

Goal state before:
pp: P P' : MorphismProperty Scheme
Q Q' : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
inst✝³ : P'.IsStableUnderBaseChange
inst✝² : P'.IsStableUnderComposition
inst✝¹ : P.IsStableUnderBaseChange
H₁ : @IsLocalIso ⊓ @Surjective ≤ P'
H₂ : ∀ {R S : CommRingCat} {f : R ⟶ S}, P' (Spec.map f) → Q' (CommRingCat.Hom.hom f)
inst✝ : HasRingHomProperty P fun {R S} [CommRing R] [CommRing S] ↦ Q
hQQ' : RingHom.CodescendsAlong (fun {R S} [CommRing R] [CommRing S] ↦ Q) fun {R S} [CommRing R] [CommRing S] ↦ Q'
R S : CommRingCat
Y : Scheme
φ : R ⟶ S
g : Y ⟶ Spec R
h : P' (Spec.map φ)
hf : P (pullback.fst (Spec.map φ) g)
this : ∀ {Y : Scheme} (g : Y ⟶ Spec R), P (pullback.fst (Spec.map φ) g) → (∃ S, Y = Spec S) → P g
hY : ¬∃ S, Y = Spec S
i : Y.affineCover.I₀
⊢ Spec.map φ ≫ 𝟙 (Spec R) = 𝟙 (Spec S) ≫ Spec.map φ

Tactic:
by simp

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

Goal state before:
pp: P P' : MorphismProperty Scheme
Q Q' : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
inst✝³ : P'.IsStableUnderBaseChange
inst✝² : P'.IsStableUnderComposition
inst✝¹ : P.IsStableUnderBaseChange
H₁ : @IsLocalIso ⊓ @Surjective ≤ P'
H₂ : ∀ {R S : CommRingCat} {f : R ⟶ S}, P' (Spec.map f) → Q' (CommRingCat.Hom.hom f)
inst✝ : HasRingHomProperty P fun {R S} [CommRing R] [CommRing S] ↦ Q
hQQ' : RingHom.CodescendsAlong (fun {R S} [CommRing R] [CommRing S] ↦ Q) fun {R S} [CommRing R] [CommRing S] ↦ Q'
R S : CommRingCat
Y : Scheme
φ : R ⟶ S
g : Y ⟶ Spec R
h : P' (Spec.map φ)
hf : P (pullback.fst (Spec.map φ) g)
this : ∀ {Y : Scheme} (g : Y ⟶ Spec R), P (pullback.fst (Spec.map φ) g) → (∃ S, Y = Spec S) → P g
hY : ¬∃ S, Y = Spec S
i : Y.affineCover.I₀
⊢ (Y.affineCover.f i ≫ g) ≫ 𝟙 (Spec R) = Y.affineCover.f i ≫ g

Tactic:
by simp

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

Goal state before:
pp: P : MorphismProperty Scheme
inst✝¹ : P.DescendsAlong (@Surjective ⊓ @Flat ⊓ @QuasiCompact)
inst✝ : IsZariskiLocalAtTarget P
R : CommRingCat
X Y : Scheme
f : X ⟶ Spec R
g : Y ⟶ Spec R
h₃ : LocallyOfFinitePresentation f
h₁ : Surjective f
h₂ : Flat f
H : P (pullback.fst f g)
⊢ Set.univ ⊆ Set.range ⇑f

Tactic:
by simp

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

Goal state before:
pp: P P' : MorphismProperty Scheme
Q Q' : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
inst✝³ : P'.IsStableUnderBaseChange
inst✝² : P'.IsStableUnderComposition
inst✝¹ : P.IsStableUnderBaseChange
H₁ : @IsLocalIso ⊓ @Surjective ≤ P'
H₂ : ∀ {R S : CommRingCat} {f : R ⟶ S}, P' (Spec.map f) → Q' (CommRingCat.Hom.hom f)
hP : HasAffineProperty P (affineAnd fun {R S} [CommRing R] [CommRing S] ↦ Q)
inst✝ : MorphismProperty.DescendsAlong (@IsAffineHom) P'
hQ : RingHom.RespectsIso fun {R S} [CommRing R] [CommRing S] ↦ Q
hQQ' : RingHom.CodescendsAlong (fun {R S} [CommRing R] [CommRing S] ↦ Q) fun {R S} [CommRing R] [CommRing S] ↦ Q'
R S : CommRingCat
Y : Scheme
φ : R ⟶ S
g : Y ⟶ Spec R
h : P' (Spec.map φ)
hf : P (pullback.fst (Spec.map φ) g)
this✝ : IsAffine Y
this : ∀ {Y : Scheme} (g : Y ⟶ Spec R), P (pullback.fst (Spec.map φ) g) → IsAffine Y → (∃ S, Y = Spec S) → P g
hY : ¬∃ S, Y = Spec S
⊢ Spec.map φ ≫ 𝟙 (Spec R) = 𝟙 (Spec S) ≫ Spec.map φ

Tactic:
by simp

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

Goal state before:
pp: P P' : MorphismProperty Scheme
Q Q' : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
inst✝³ : P'.IsStableUnderBaseChange
inst✝² : P'.IsStableUnderComposition
inst✝¹ : P.IsStableUnderBaseChange
H₁ : @IsLocalIso ⊓ @Surjective ≤ P'
H₂ : ∀ {R S : CommRingCat} {f : R ⟶ S}, P' (Spec.map f) → Q' (CommRingCat.Hom.hom f)
hP : HasAffineProperty P (affineAnd fun {R S} [CommRing R] [CommRing S] ↦ Q)
inst✝ : MorphismProperty.DescendsAlong (@IsAffineHom) P'
hQ : RingHom.RespectsIso fun {R S} [CommRing R] [CommRing S] ↦ Q
hQQ' : RingHom.CodescendsAlong (fun {R S} [CommRing R] [CommRing S] ↦ Q) fun {R S} [CommRing R] [CommRing S] ↦ Q'
R S : CommRingCat
Y : Scheme
φ : R ⟶ S
g : Y ⟶ Spec R
h : P' (Spec.map φ)
hf : P (pullback.fst (Spec.map φ) g)
this✝ : IsAffine Y
this : ∀ {Y : Scheme} (g : Y ⟶ Spec R), P (pullback.fst (Spec.map φ) g) → IsAffine Y → (∃ S, Y = Spec S) → P g
hY : ¬∃ S, Y = Spec S
⊢ (Y.isoSpec.inv ≫ g) ≫ 𝟙 (Spec R) = Y.isoSpec.inv ≫ g

Tactic:
by simp

Goal state after:
Module: Mathlib.RingTheory.IntegralClosure.IsIntegral.AlmostIntegral

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
a b : S
r : R
hr : r ∈ R⁰
hr' : ∀ (n : ℕ), r • a ^ n ∈ (algebraMap R S).range
s : R
hs : s ∈ R⁰
hs' : ∀ (n : ℕ), s • b ^ n ∈ (algebraMap R S).range
n i : ℕ
x✝ : i ∈ Finset.range (n + 1)
⊢ ↑(n.choose i) ∈ (algebraMap R S).range

Tactic:
by simp

Goal state after:
Module: Mathlib.RingTheory.IntegralClosure.GoingDown

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝⁸ : CommRing R
inst✝⁷ : CommRing S
inst✝⁶ : Algebra R S
inst✝⁵ : IsDomain S
inst✝⁴ : FaithfulSMul R S
inst✝³ : Algebra.IsIntegral R S
inst✝² : IsIntegrallyClosed R
this✝¹ : IsDomain R
p : Ideal R
inst✝¹ : p.IsPrime
Q : Ideal S
inst✝ : Q.IsPrime
hpQ : p < Ideal.under R Q
SQ : Type u_2 := Localization.AtPrime Q
x : R
hx : x ∈ Ideal.comap (algebraMap R SQ) (Ideal.map (algebraMap R SQ) p)
a : S
ha : x • a ∈ Ideal.map (algebraMap R S) p
haQ : a ∉ Q
f : R[X]
hfm : f.Monic
hfa : (aeval (x • a)) f = 0
hf : ∀ (i : ℕ), i ≠ f.natDegree → f.coeff i ∈ p
g : R[X] := minpoly R a
H : ∀ (i : ℕ), i ≠ g.natDegree → g.coeff i ∈ p
this✝ : map (Ideal.Quotient.mk p) g = X ^ g.natDegree
this : (Ideal.Quotient.mk (Ideal.map (algebraMap R S) p)) (a ^ (minpoly R a).natDegree) = 0
⊢ False

Tactic:
exact haQ (‹Q.IsPrime›.mem_of_pow_mem _
      (Ideal.map_le_iff_le_comap.mpr hpQ.le (Ideal.Quotient.eq_zero_iff_mem.mp this)))

Goal state after:
Module: Mathlib.RingTheory.IntegralClosure.IsIntegral.AlmostIntegral

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing S
inst✝¹ : Algebra R S
M : Submonoid R
hM : M ≤ R⁰
inst✝ : IsLocalization M S
s : R
t : ↥M
H : IsIntegral R (IsLocalization.mk' S s t)
⊢ ↑t • IsLocalization.mk' S s t ∈ (algebraMap R S).range

Tactic:
by simp

Goal state after:
Module: Mathlib.RingTheory.IntegralClosure.IsIntegral.AlmostIntegral

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : Algebra R S
inst✝² : IsNoetherianRing R
inst✝¹ : IsDomain S
inst✝ : FaithfulSMul R S
s : S
H : IsAlmostIntegral R s
this : IsDomain R
x✝ : R
⊢ x✝ ∈ R⁰ → x✝ ∈ Submonoid.comap (algebraMap R S) S⁰

Tactic:
by simp

Goal state after:
Module: Mathlib.FieldTheory.RatFunc.Defs

Goal state before:
pp: case neg
K : Type u
inst✝¹ : CommRing K
inst✝ : IsDomain K
P : Sort v
p q : K[X]
f : K[X] → K[X] → P
f0 : ∀ (p : K[X]), f p 0 = f 0 1
H' : ∀ {p q p' q' : K[X]}, q ≠ 0 → q' ≠ 0 → q' * p = q * p' → f p q = f p' q'
H : ∀ {p q p' q' : K[X]}, q ∈ K[X]⁰ → q' ∈ K[X]⁰ → q' * p = q * p' → f p q = f p' q'
hq : ¬q = 0
⊢ (RatFunc.mk p q).liftOn f H = f p q

Tactic:
simp only [mk_eq_localization_mk _ hq, liftOn_ofFractionRing_mk]

Goal state after:
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
hpos : 1 < v w
p : A[X]
hp : p ≠ 0
⊢ p.natDegree ∈ Finset.range (p.natDegree + 1)

Tactic:
by simp

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

Goal state before:
pp: R : Type u_1
S : Type u_2
ι : Type u_3
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
p : ι → S[X]
a : ι
s : Finset ι
has : a ∉ s
IH : (∀ i ∈ s, ∀ (j : ℕ), IsIntegral R ((p i).coeff j)) → ∀ (j : ℕ), IsIntegral R ((s.prod p).coeff j)
H : ∀ i ∈ insert a s, ∀ (j : ℕ), IsIntegral R ((p i).coeff j)
j : ℕ
i : ℕ × ℕ
hi : i ∈ Finset.antidiagonal j
⊢ a ∈ insert a s

Tactic:
by simp

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

Goal state before:
pp: case h
R : Type u_1
S : Type u_2
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : Algebra R S
inst✝¹ : IsDomain R
inst✝ : FaithfulSMul R S
p✝ : S[X]
hp✝ : IsAlmostIntegral R[X] p✝
i : ℕ
q : S[X]
p : R[X]
hp : p ∈ R[X]⁰
hp' : ∀ (n : ℕ), p • q ^ n ∈ (algebraMap R[X] S[X]).range
n : ℕ
r : R[X]
hr : map (algebraMap R S) r = map (algebraMap R S) p * q ^ n
h' : q.leadingCoeff ^ n ≠ 0
h : ¬(map (algebraMap R S) p).leadingCoeff * (q ^ n).leadingCoeff = 0
⊢ (map (algebraMap R S) p * q ^ n).leadingCoeff = (map (algebraMap R S) p).leadingCoeff * (q ^ n).leadingCoeff

Tactic:
leadingCoeff_mul' h

Goal state after:
case h
R : Type u_1
S : Type u_2
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : Algebra R S
inst✝¹ : IsDomain R
inst✝ : FaithfulSMul R S
p✝ : S[X]
hp✝ : IsAlmostIntegral R[X] p✝
i : ℕ
q : S[X]
p : R[X]
hp : p ∈ R[X]⁰
hp' : ∀ (n : ℕ), p • q ^ n ∈ (algebraMap R[X] S[X]).range
n : ℕ
r : R[X]
hr : map (algebraMap R S) r = map (algebraMap R S) p * q ^ n
h' : q.leadingCoeff ^ n ≠ 0
h : ¬(map (algebraMap R S) p).leadingCoeff * (q ^ n).leadingCoeff = 0
⊢ (map (algebraMap R S) p).leadingCoeff * (q ^ n).leadingCoeff =
    (map (algebraMap R S) p).leadingCoeff * (q ^ n).leadingCoeff
Module: Mathlib.RingTheory.Polynomial.IsIntegral

Goal state before:
pp: case pos
R : Type u_1
S : Type u_2
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : Algebra R S
inst✝¹ : IsDomain R
inst✝ : FaithfulSMul R S
i : ℕ
H : ∀ {q : S[X]}, IsAlmostIntegral R[X] q → IsAlmostIntegral R q.leadingCoeff
n : ℕ
IH : ∀ m < n, ∀ {p : S[X]}, IsAlmostIntegral R[X] p → p.natDegree = m → IsAlmostIntegral R (p.coeff i)
p : S
hp : IsAlmostIntegral R[X] (C p)
hn : (C p).natDegree = n
hp' : (C p).natDegree = 0
h : i = 0
⊢ IsAlmostIntegral R p

pp: case neg
R : Type u_1
S : Type u_2
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : Algebra R S
inst✝¹ : IsDomain R
inst✝ : FaithfulSMul R S
i : ℕ
H : ∀ {q : S[X]}, IsAlmostIntegral R[X] q → IsAlmostIntegral R q.leadingCoeff
n : ℕ
IH : ∀ m < n, ∀ {p : S[X]}, IsAlmostIntegral R[X] p → p.natDegree = m → IsAlmostIntegral R (p.coeff i)
p : S
hp : IsAlmostIntegral R[X] (C p)
hn : (C p).natDegree = n
hp' : (C p).natDegree = 0
h : ¬i = 0
⊢ IsAlmostIntegral R 0

Tactic:
· simpa using H hp

Goal state after:
case neg
R : Type u_1
S : Type u_2
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : Algebra R S
inst✝¹ : IsDomain R
inst✝ : FaithfulSMul R S
i : ℕ
H : ∀ {q : S[X]}, IsAlmostIntegral R[X] q → IsAlmostIntegral R q.leadingCoeff
n : ℕ
IH : ∀ m < n, ∀ {p : S[X]}, IsAlmostIntegral R[X] p → p.natDegree = m → IsAlmostIntegral R (p.coeff i)
p : S
hp : IsAlmostIntegral R[X] (C p)
hn : (C p).natDegree = n
hp' : (C p).natDegree = 0
h : ¬i = 0
⊢ IsAlmostIntegral R 0
Module: Mathlib.RingTheory.Polynomial.IsIntegral

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 : IsDomain R
inst✝ : FaithfulSMul R S
i : ℕ
H : ∀ {q : S[X]}, IsAlmostIntegral R[X] q → IsAlmostIntegral R q.leadingCoeff
n : ℕ
IH : ∀ m < n, ∀ {p : S[X]}, IsAlmostIntegral R[X] p → p.natDegree = m → IsAlmostIntegral R (p.coeff i)
p : S[X]
hp : IsAlmostIntegral R[X] p
hn : p.natDegree = n
hp' : ¬p.natDegree = 0
hi : ¬i = p.natDegree
⊢ p - C p.leadingCoeff * map (algebraMap R S) X ^ p.natDegree ∈ completeIntegralClosure R[X] S[X]

Tactic:
← Polynomial.map_pow

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 : IsDomain R
inst✝ : FaithfulSMul R S
i : ℕ
H : ∀ {q : S[X]}, IsAlmostIntegral R[X] q → IsAlmostIntegral R q.leadingCoeff
n : ℕ
IH : ∀ m < n, ∀ {p : S[X]}, IsAlmostIntegral R[X] p → p.natDegree = m → IsAlmostIntegral R (p.coeff i)
p : S[X]
hp : IsAlmostIntegral R[X] p
hn : p.natDegree = n
hp' : ¬p.natDegree = 0
hi : ¬i = p.natDegree
⊢ p - C p.leadingCoeff * map (algebraMap R S) (X ^ p.natDegree) ∈ completeIntegralClosure R[X] S[X]