mathlib-initiative/mathlib-tactics huggingface dataset:
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
φ : R ⟶ S
h : P' (Spec.map φ)
Y : Scheme
g : Y ⟶ Spec R
hf : P (pullback.fst (Spec.map φ) g)
hY : ∃ S, Y = Spec S
⊢ P g

Tactic:
obtain ⟨S, rfl⟩ := hY

Goal state after:
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
φ : R ⟶ S✝
h : P' (Spec.map φ)
S : CommRingCat
g : Spec S ⟶ Spec R
hf : P (pullback.fst (Spec.map φ) g)
⊢ P g
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),
    P' (Spec.map φ) → P (pullback.fst (Spec.map φ) g) → P g

Tactic:
introv h hf

Goal state after:
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)
⊢ P 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 - (minpoly R s).natDegree) *
          ∑ x ∈ Finset.range (minpoly R s).natDegree, (minpoly R s).coeff x • s ^ x)) ∈
    (algebraMap R S).range

Tactic:
Finset.mul_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
⊢ -(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
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
hx : comap (algebraMap R S) (conductor R x) ⊔ I = ⊤
h_alg : Function.Injective ⇑(algebraMap (↥R[x]) S)
z : S
hz : z ∈ R[x]
hy : ⟨z, hz⟩ ∈ comap (algebraMap (↥R[x]) S) (Ideal.map (algebraMap R S) I)
p : R
hp : p ∈ comap (algebraMap R S) (conductor R x)
q : R
hq : q ∈ I
hpq : p + q = 1
temp : (algebraMap R S) p * z + (algebraMap R S) q * z = z
h : ⟨z, hz⟩ ∈ Ideal.map (algebraMap R ↥R[x]) I
⊢ ⟨z, hz⟩ ∈ ↑(Ideal.map (algebraMap R ↥R[x]) I)

Tactic:
by simp [h]

Goal state after:
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
hx : comap (algebraMap R S) (conductor R x) ⊔ I = ⊤
h_alg : Function.Injective ⇑(algebraMap (↥R[x]) S)
f : ↥R[x] ⧸ Ideal.map (algebraMap R ↥R[x]) I →+* S ⧸ Ideal.map (algebraMap R S) I :=
  Ideal.Quotient.lift (Ideal.map (algebraMap R ↥R[x]) I)
    ((Ideal.Quotient.mk (Ideal.map (algebraMap R S) I)).comp (algebraMap (↥R[x]) S)) ⋯
y : S ⧸ Ideal.map (algebraMap R S) I
z : S
hz : (Ideal.Quotient.mk (Ideal.map (algebraMap R S) I)) z = y
this : conductor R x ⊔ Ideal.map (algebraMap R S) I = ⊤
⊢ z ∈ conductor R x ⊔ Ideal.map (algebraMap R S) I

Tactic:
by simp only [this, Submodule.mem_top]

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

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
p : S[X]
hpmon : IsIntegral R p.leadingCoeff
hp : p.Splits
hpr : ∀ (x : S), p.IsRoot x → IsIntegral R x
i : ℕ
m : Multiset S
hm : p = C p.leadingCoeff * (Multiset.map (fun x ↦ X - C x) m).prod
x : S
hx : x ∈ m
⊢ eval x (C p.leadingCoeff) * eval x (Multiset.map (fun x ↦ X - C x) m).prod = 0

Tactic:
eval_multiset_prod,

Goal state after:
R : Type u_1
S : Type u_2
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
p : S[X]
hpmon : IsIntegral R p.leadingCoeff
hp : p.Splits
hpr : ∀ (x : S), p.IsRoot x → IsIntegral R x
i : ℕ
m : Multiset S
hm : p = C p.leadingCoeff * (Multiset.map (fun x ↦ X - C x) m).prod
x : S
hx : x ∈ m
⊢ eval x (C p.leadingCoeff) * (Multiset.map (eval x) (Multiset.map (fun x ↦ X - C x) m)).prod = 0
Module: Mathlib.RingTheory.Polynomial.IsIntegral

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
σ : Type w
hσ : Finite σ
α β : Type w
e : α ≃ β
IH :
  ∀ {f : MvPolynomial α S},
    (algebraMap (MvPolynomial α R) (MvPolynomial α S)).IsIntegralElem f → ∀ (n : α →₀ ℕ), IsIntegral R (coeff n f)
f : MvPolynomial β S
H : (algebraMap (MvPolynomial β R) (MvPolynomial β S)).IsIntegralElem f
⊢ ∀ (n : β →₀ ℕ), IsIntegral R (coeff n f)

Tactic:
n

Goal state after:
R : Type u_1
S : Type u_2
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
σ : Type w
hσ : Finite σ
α β : Type w
e : α ≃ β
IH :
  ∀ {f : MvPolynomial α S},
    (algebraMap (MvPolynomial α R) (MvPolynomial α S)).IsIntegralElem f → ∀ (n : α →₀ ℕ), IsIntegral R (coeff n f)
f : MvPolynomial β S
H : (algebraMap (MvPolynomial β R) (MvPolynomial β S)).IsIntegralElem f
n : β →₀ ℕ
⊢ IsIntegral R (coeff n f)
Module: Mathlib.RingTheory.LocalRing.ResidueField.Polynomial

Goal state before:
pp: case refine_1
R : Type u_1
S : Type u_2
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : Algebra R S
I : Ideal R
inst✝⁴ : I.IsPrime
J : Ideal R[X]
inst✝³ : J.IsPrime
inst✝² : J.LiesOver I
inst✝¹ : Algebra (Localization.AtPrime I) (Localization.AtPrime J)
inst✝ : Localization.AtPrime.IsLiesOverAlgebra I J
hJ : J = Ideal.map C I
f : J.ResidueField →+* RatFunc I.ResidueField :=
  Ideal.ResidueField.lift J
    ((algebraMap I.ResidueField[X] (RatFunc I.ResidueField)).comp (mapRingHom (algebraMap R I.ResidueField))) ⋯ ⋯
hf : f.comp (algebraMap I.ResidueField J.ResidueField) = algebraMap I.ResidueField (RatFunc I.ResidueField)
x✝ : I.ResidueField[X]
x : I.ResidueField[X]
hx : (aeval ((algebraMap R[X] J.ResidueField) X)) x = 0
r : R[X]
hr : map (Ideal.Quotient.mk I) r = IsLocalization.integerNormalization (R ⧸ I)⁰ x
⊢ x = 0

Tactic:
obtain ⟨s, hs, hr⟩ : ∃ s ∉ I, r.map (algebraMap _ _) = s • x := by
      obtain ⟨b, hb0, hb⟩ := IsLocalization.integerNormalization_spec (R ⧸ I)⁰ x
      obtain ⟨s, rfl⟩ := Ideal.Quotient.mk_surjective b
      refine ⟨s, by simpa [Ideal.Quotient.eq_zero_iff_mem] using! hb0, ?_⟩
      simpa [← hr, map_map, ← Ideal.Quotient.algebraMap_eq] using! hb

Goal state after:
case refine_1
R : Type u_1
S : Type u_2
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : Algebra R S
I : Ideal R
inst✝⁴ : I.IsPrime
J : Ideal R[X]
inst✝³ : J.IsPrime
inst✝² : J.LiesOver I
inst✝¹ : Algebra (Localization.AtPrime I) (Localization.AtPrime J)
inst✝ : Localization.AtPrime.IsLiesOverAlgebra I J
hJ : J = Ideal.map C I
f : J.ResidueField →+* RatFunc I.ResidueField :=
  Ideal.ResidueField.lift J
    ((algebraMap I.ResidueField[X] (RatFunc I.ResidueField)).comp (mapRingHom (algebraMap R I.ResidueField))) ⋯ ⋯
hf : f.comp (algebraMap I.ResidueField J.ResidueField) = algebraMap I.ResidueField (RatFunc I.ResidueField)
x✝ : I.ResidueField[X]
x : I.ResidueField[X]
hx : (aeval ((algebraMap R[X] J.ResidueField) X)) x = 0
r : R[X]
hr✝ : map (Ideal.Quotient.mk I) r = IsLocalization.integerNormalization (R ⧸ I)⁰ x
s : R
hs : s ∉ I
hr : map (algebraMap R I.ResidueField) r = s • x
⊢ x = 0
Module: Mathlib.RingTheory.Polynomial.IsIntegral

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
σ : Type w
hσ : Finite σ
f : MvPolynomial PEmpty.{w + 1} S
H : (algebraMap (MvPolynomial PEmpty.{w + 1} R) (MvPolynomial PEmpty.{w + 1} S)).IsIntegralElem f
⊢ ∀ (n : PEmpty.{w + 1} →₀ ℕ), IsIntegral R (coeff n f)

Tactic:
n

Goal state after:
R : Type u_1
S : Type u_2
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
σ : Type w
hσ : Finite σ
f : MvPolynomial PEmpty.{w + 1} S
H : (algebraMap (MvPolynomial PEmpty.{w + 1} R) (MvPolynomial PEmpty.{w + 1} S)).IsIntegralElem f
n : PEmpty.{w + 1} →₀ ℕ
⊢ IsIntegral R (coeff n f)
Module: Mathlib.RingTheory.Polynomial.IsIntegral

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
σ : Type w
hσ : Finite σ
α : Type w
inst✝ : Fintype α
IH :
  ∀ {f : MvPolynomial α S},
    (algebraMap (MvPolynomial α R) (MvPolynomial α S)).IsIntegralElem f → ∀ (n : α →₀ ℕ), IsIntegral R (coeff n f)
f : MvPolynomial (Option α) S
H : (algebraMap (MvPolynomial (Option α) R) (MvPolynomial (Option α) S)).IsIntegralElem f
⊢ ∀ (n : Option α →₀ ℕ), IsIntegral R (coeff n f)

Tactic:
n

Goal state after:
R : Type u_1
S : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing S
inst✝¹ : Algebra R S
σ : Type w
hσ : Finite σ
α : Type w
inst✝ : Fintype α
IH :
  ∀ {f : MvPolynomial α S},
    (algebraMap (MvPolynomial α R) (MvPolynomial α S)).IsIntegralElem f → ∀ (n : α →₀ ℕ), IsIntegral R (coeff n f)
f : MvPolynomial (Option α) S
H : (algebraMap (MvPolynomial (Option α) R) (MvPolynomial (Option α) S)).IsIntegralElem f
n : Option α →₀ ℕ
⊢ IsIntegral R (coeff n f)
Module: Mathlib.FieldTheory.RatFunc.Basic

Goal state before:
pp: case neg
K : Type u
inst✝⁴ : CommRing K
R : Type u_1
inst✝³ : IsDomain K
inst✝² : Monoid R
inst✝¹ : DistribMulAction R K[X]
inst✝ : IsScalarTower R K[X] K[X]
c : R
p q : K[X]
this : SMulZeroClass R (FractionRing K[X]) := inferInstance
hq : ¬q = 0
⊢ RatFunc.mk (c • p) q = c • RatFunc.mk p q

Tactic:
mk_eq_localization_mk _ hq,

Goal state after:
case neg
K : Type u
inst✝⁴ : CommRing K
R : Type u_1
inst✝³ : IsDomain K
inst✝² : Monoid R
inst✝¹ : DistribMulAction R K[X]
inst✝ : IsScalarTower R K[X] K[X]
c : R
p q : K[X]
this : SMulZeroClass R (FractionRing K[X]) := inferInstance
hq : ¬q = 0
⊢ { toFractionRing := Localization.mk (c • p) ⟨q, ⋯⟩ } = c • RatFunc.mk p q
Module: Mathlib.FieldTheory.RatFunc.Basic

Goal state before:
pp: case neg
K : Type u
inst✝⁴ : CommRing K
R : Type u_1
inst✝³ : IsDomain K
inst✝² : Monoid R
inst✝¹ : DistribMulAction R K[X]
inst✝ : IsScalarTower R K[X] K[X]
c : R
p q : K[X]
this : SMulZeroClass R (FractionRing K[X]) := inferInstance
hq : ¬q = 0
⊢ { toFractionRing := Localization.mk (c • p) ⟨q, ⋯⟩ } = c • RatFunc.mk p q

Tactic:
mk_eq_localization_mk _ hq,

Goal state after:
case neg
K : Type u
inst✝⁴ : CommRing K
R : Type u_1
inst✝³ : IsDomain K
inst✝² : Monoid R
inst✝¹ : DistribMulAction R K[X]
inst✝ : IsScalarTower R K[X] K[X]
c : R
p q : K[X]
this : SMulZeroClass R (FractionRing K[X]) := inferInstance
hq : ¬q = 0
⊢ { toFractionRing := Localization.mk (c • p) ⟨q, ⋯⟩ } = c • { toFractionRing := Localization.mk p ⟨q, ⋯⟩ }
Module: Mathlib.AlgebraicGeometry.Sites.SmallAffineZariski

Goal state before:
pp: X : Scheme
F : X.AffineZariskiSiteᵒᵖ ⥤ CommRingCat
α : (toOpensFunctor X).op ⋙ X.presheaf ⟶ F
H : NatTrans.Coequifibered α
⊢ ∀ ⦃U V : X.AffineZariskiSite⦄ (f : U ⟶ V), IsOpenImmersion ((F.rightOp ⋙ Scheme.Spec).map f)

Tactic:
exact fun U V ↦ (relativeGluingData H).instIsOpenImmersionMapI₀Functor

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

Goal state before:
pp: case pos
k : Type u_3
K : Type u_4
inst✝³ : Field k
inst✝² : Field K
inst✝¹ : Algebra k K
inst✝ : Algebra.IsAlgebraic k K
hf : Module.Finite k⟮X⟯ K⟮X⟯
⊢ Module.finrank k⟮X⟯ K⟮X⟯ = Module.finrank k K

Tactic:
have hrank := rank_ratFunc_ratFunc k K

Goal state after:
case pos
k : Type u_3
K : Type u_4
inst✝³ : Field k
inst✝² : Field K
inst✝¹ : Algebra k K
inst✝ : Algebra.IsAlgebraic k K
hf : Module.Finite k⟮X⟯ K⟮X⟯
hrank : Module.rank k⟮X⟯ K⟮X⟯ = Module.rank k K
⊢ Module.finrank k⟮X⟯ K⟮X⟯ = Module.finrank k K
Module: Mathlib.FieldTheory.RatFunc.Basic

Goal state before:
pp: K : Type u
inst✝ : Field K
p q : K[X]
hq : q ≠ 0
⊢ ((algebraMap K[X] K⟮X⟯) p / (algebraMap K[X] K⟮X⟯) q).numDenom.1 = C (q / gcd p q).leadingCoeff⁻¹ * (p / gcd p q)

Tactic:
numDenom_div _ hq

Goal state after:
K : Type u
inst✝ : Field K
p q : K[X]
hq : q ≠ 0
⊢ (C (q / gcd p q).leadingCoeff⁻¹ * (p / gcd p q), C (q / gcd p q).leadingCoeff⁻¹ * (q / gcd p q)).1 =
    C (q / gcd p q).leadingCoeff⁻¹ * (p / gcd p q)
Module: Mathlib.FieldTheory.RatFunc.Basic

Goal state before:
pp: K : Type u
inst✝ : Field K
p q : K[X]
hq : q ≠ 0
⊢ ((algebraMap K[X] K⟮X⟯) p / (algebraMap K[X] K⟮X⟯) q).numDenom.2 = C (q / gcd p q).leadingCoeff⁻¹ * (q / gcd p q)

Tactic:
numDenom_div _ hq

Goal state after:
K : Type u
inst✝ : Field K
p q : K[X]
hq : q ≠ 0
⊢ (C (q / gcd p q).leadingCoeff⁻¹ * (p / gcd p q), C (q / gcd p q).leadingCoeff⁻¹ * (q / gcd p q)).2 =
    C (q / gcd p q).leadingCoeff⁻¹ * (q / gcd p q)
Module: Mathlib.FieldTheory.RatFunc.Basic

Goal state before:
pp: K : Type u
inst✝ : Field K
x : K⟮X⟯
p q : K[X]
hq : q ≠ 0
⊢ (algebraMap K[X] K⟮X⟯) (x.num * q) = (algebraMap K[X] K⟮X⟯) (p * x.denom) ↔
    x * (algebraMap K[X] K⟮X⟯) q = (algebraMap K[X] K⟮X⟯) p

Tactic:
conv_rhs => rw [← num_div_denom x]

Goal state after:
K : Type u
inst✝ : Field K
x : K⟮X⟯
p q : K[X]
hq : q ≠ 0
⊢ (algebraMap K[X] K⟮X⟯) (x.num * q) = (algebraMap K[X] K⟮X⟯) (p * x.denom) ↔
    (algebraMap K[X] K⟮X⟯) x.num / (algebraMap K[X] K⟮X⟯) x.denom * (algebraMap K[X] K⟮X⟯) q = (algebraMap K[X] K⟮X⟯) p
Module: Mathlib.FieldTheory.RatFunc.Basic

Goal state before:
pp: K : Type u
inst✝ : Field K
x : K⟮X⟯
⊢ -x = -((algebraMap K[X] K⟮X⟯) x.num / (algebraMap K[X] K⟮X⟯) x.denom)

Tactic:
num_div_denom

Goal state after:
K : Type u
inst✝ : Field K
x : K⟮X⟯
⊢ -x = -x
Module: Mathlib.FieldTheory.RatFunc.Basic

Goal state before:
pp: case h
K : Type u
inst✝ : Field K
x : K⟮X⟯
q : K[X]
hp : x.num * q ≠ 0
_hx : x.num ≠ 0
hq : q ≠ 0
⊢ x.denom * q ≠ 0 ∧ x = (algebraMap K[X] K⟮X⟯) x.num / (algebraMap K[X] K⟮X⟯) x.denom

pp: case h
K : Type u
inst✝ : Field K
x : K⟮X⟯
q : K[X]
hp : x.num * q ≠ 0
_hx : x.num ≠ 0
hq : q ≠ 0
⊢ (algebraMap K[X] K⟮X⟯) q ≠ 0

Tactic:
num_div_denom

Goal state after:
case h
K : Type u
inst✝ : Field K
x : K⟮X⟯
q : K[X]
hp : x.num * q ≠ 0
_hx : x.num ≠ 0
hq : q ≠ 0
⊢ x.denom * q ≠ 0 ∧ x = x

case h
K : Type u
inst✝ : Field K
x : K⟮X⟯
q : K[X]
hp : x.num * q ≠ 0
_hx : x.num ≠ 0
hq : q ≠ 0
⊢ (algebraMap K[X] K⟮X⟯) q ≠ 0
Module: Mathlib.FieldTheory.RatFunc.Basic

Goal state before:
pp: case h
K : Type u
inst✝ : Field K
x : K⟮X⟯
p : K[X]
hq : x.denom * p ≠ 0
_hx : x.denom ≠ 0
hp : p ≠ 0
⊢ x = (algebraMap K[X] K⟮X⟯) x.num / (algebraMap K[X] K⟮X⟯) x.denom

pp: case h
K : Type u
inst✝ : Field K
x : K⟮X⟯
p : K[X]
hq : x.denom * p ≠ 0
_hx : x.denom ≠ 0
hp : p ≠ 0
⊢ (algebraMap K[X] K⟮X⟯) p ≠ 0

Tactic:
num_div_denom

Goal state after:
case h
K : Type u
inst✝ : Field K
x : K⟮X⟯
p : K[X]
hq : x.denom * p ≠ 0
_hx : x.denom ≠ 0
hp : p ≠ 0
⊢ x = x

case h
K : Type u
inst✝ : Field K
x : K⟮X⟯
p : K[X]
hq : x.denom * p ≠ 0
_hx : x.denom ≠ 0
hp : p ≠ 0
⊢ (algebraMap K[X] K⟮X⟯) p ≠ 0
Module: Mathlib.FieldTheory.RatFunc.Basic

Goal state before:
pp: case neg
K : Type u
inst✝ : Field K
x y : K⟮X⟯
hx : ¬x = 0
hy : ¬y = 0
⊢ x * y = x * ((algebraMap K[X] K⟮X⟯) y.num / (algebraMap K[X] K⟮X⟯) y.denom)

Tactic:
num_div_denom

Goal state after:
case neg
K : Type u
inst✝ : Field K
x y : K⟮X⟯
hx : ¬x = 0
hy : ¬y = 0
⊢ x * y = x * y
Module: Mathlib.FieldTheory.RatFunc.Basic

Goal state before:
pp: K : Type u
inst✝ : Field K
x y : K⟮X⟯
⊢ x * y = x * ((algebraMap K[X] K⟮X⟯) y.num / (algebraMap K[X] K⟮X⟯) y.denom)

Tactic:
num_div_denom

Goal state after:
K : Type u
inst✝ : Field K
x y : K⟮X⟯
⊢ x * y = x * y
Module: Mathlib.FieldTheory.RatFunc.Basic

Goal state before:
pp: K : Type u
inst✝ : Field K
x y : K⟮X⟯
⊢ x + y = x + (algebraMap K[X] K⟮X⟯) y.num / (algebraMap K[X] K⟮X⟯) y.denom

pp: case hb
K : Type u
inst✝ : Field K
x y : K⟮X⟯
⊢ (algebraMap K[X] K⟮X⟯) x.denom ≠ 0

pp: case hd
K : Type u
inst✝ : Field K
x y : K⟮X⟯
⊢ (algebraMap K[X] K⟮X⟯) y.denom ≠ 0

Tactic:
num_div_denom

Goal state after:
K : Type u
inst✝ : Field K
x y : K⟮X⟯
⊢ x + y = x + y

case hb
K : Type u
inst✝ : Field K
x y : K⟮X⟯
⊢ (algebraMap K[X] K⟮X⟯) x.denom ≠ 0

case hd
K : Type u
inst✝ : Field K
x y : K⟮X⟯
⊢ (algebraMap K[X] K⟮X⟯) y.denom ≠ 0
Module: Mathlib.FieldTheory.RatFunc.Basic

Goal state before:
pp: K : Type u
inst✝¹ : Field K
L : Type u_1
inst✝ : CommGroupWithZero L
φ : K[X] →*₀ L
hφ : K[X]⁰ ≤ Submonoid.comap φ L⁰
f : K⟮X⟯
⊢ φ f.num / φ f.denom =
    φ ((algebraMap K[X] K⟮X⟯) f.num / (algebraMap K[X] K⟮X⟯) f.denom).num /
      φ ((algebraMap K[X] K⟮X⟯) f.num / (algebraMap K[X] K⟮X⟯) f.denom).denom

Tactic:
num_div_denom

Goal state after:
K : Type u
inst✝¹ : Field K
L : Type u_1
inst✝ : CommGroupWithZero L
φ : K[X] →*₀ L
hφ : K[X]⁰ ≤ Submonoid.comap φ L⁰
f : K⟮X⟯
⊢ φ f.num / φ f.denom = φ f.num / φ f.denom
Module: Mathlib.RingTheory.Unramified.LocalStructure

Goal state before:
pp: case e'_3.e'_8
R : Type u_1
S : Type u_3
inst✝³ : CommRing R
inst✝² : CommRing S
inst✝¹ : Algebra R S
P : Ideal R
inst✝ : P.IsPrime
x : S
hx : R[x] = ⊤
hx' : Function.Surjective ⇑(aeval x)
I : Ideal R[X] := RingHom.ker (aeval x).toRingHom
e : P.Fiber S ≃ₐ[P.ResidueField] P.ResidueField[X] ⧸ Ideal.map (mapRingHom (algebraMap R P.ResidueField)) I :=
  fiberEquivQuotient (aeval x) hx' P
⊢ e.toRingEquiv.toRingHom.comp (aeval (1 ⊗ₜ[R] x)).toRingHom =
    Ideal.Quotient.mk (Ideal.map (mapRingHom (algebraMap R P.ResidueField)) (RingHom.ker (aeval x).toRingHom))

Tactic:
ext a

Goal state after:
case e'_3.e'_8.h₁
R : Type u_1
S : Type u_3
inst✝³ : CommRing R
inst✝² : CommRing S
inst✝¹ : Algebra R S
P : Ideal R
inst✝ : P.IsPrime
x : S
hx : R[x] = ⊤
hx' : Function.Surjective ⇑(aeval x)
I : Ideal R[X] := RingHom.ker (aeval x).toRingHom
e : P.Fiber S ≃ₐ[P.ResidueField] P.ResidueField[X] ⧸ Ideal.map (mapRingHom (algebraMap R P.ResidueField)) I :=
  fiberEquivQuotient (aeval x) hx' P
a : R
⊢ (((e.toRingEquiv.toRingHom.comp (aeval (1 ⊗ₜ[R] x)).toRingHom).comp C).comp (algebraMap R P.ResidueField)) a =
    (((Ideal.Quotient.mk (Ideal.map (mapRingHom (algebraMap R P.ResidueField)) (RingHom.ker (aeval x).toRingHom))).comp
            C).comp
        (algebraMap R P.ResidueField))
      a

case h₂
R : Type u_1
S : Type u_3
inst✝³ : CommRing R
inst✝² : CommRing S
inst✝¹ : Algebra R S
P : Ideal R
inst✝ : P.IsPrime
x : S
hx : R[x] = ⊤
hx' : Function.Surjective ⇑(aeval x)
I : Ideal R[X] := ⋯
e : P.Fiber S ≃ₐ[P.ResidueField] P.ResidueField[X] ⧸ Ideal.map (mapRingHom (algebraMap R P.ResidueField)) I := ⋯
⊢ (e.toRingEquiv.toRingHom.comp (aeval (1 ⊗ₜ[R] x)).toRingHom) X =
    (Ideal.Quotient.mk (Ideal.map (mapRingHom (algebraMap R P.ResidueField)) (RingHom.ker (aeval x).toRingHom))) X
Module: Mathlib.RingTheory.Smooth.IntegralClosure

Goal state before:
pp: R : Type u_1
S : Type u_2
B : Type u_3
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : Algebra R S
inst✝² : CommRing B
inst✝¹ : Algebra R B
inst✝ : Module.Flat R S
⊢ Function.Injective ⇑(Algebra.TensorProduct.map (AlgHom.id S S) (integralClosure R B).val)

Tactic:
exact Module.Flat.lTensor_preserves_injective_linearMap (M := S)
    (integralClosure R B).val.toLinearMap Subtype.val_injective

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

Goal state before:
pp: R : Type u_1
S : Type u_2
B : Type u_3
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : Algebra R S
inst✝² : CommRing B
inst✝¹ : Algebra R B
inst✝ : Module.Flat R S
⊢ Function.Injective ⇑(toIntegralClosure R S B)

Tactic:
by
  refine Function.Injective.of_comp (f := (integralClosure _ _).val) ?_
  rw [← AlgHom.coe_comp, toIntegralClosure, AlgHom.val_comp_codRestrict]
  exact Module.Flat.lTensor_preserves_injective_linearMap (M := S)
    (integralClosure R B).val.toLinearMap Subtype.val_injective

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

Goal state before:
pp: R : Type u_1
S : Type u_3
inst✝⁸ : CommRing R
inst✝⁷ : CommRing S
inst✝⁶ : Algebra R S
P : Ideal R
inst✝⁵ : P.IsPrime
Q : Ideal S
inst✝⁴ : Q.IsPrime
inst✝³ : Q.LiesOver P
inst✝² : IsUnramifiedAt R Q
x : S
p : R[X]
inst✝¹ : Algebra (Localization.AtPrime P) (Localization.AtPrime Q)
inst✝ : Localization.AtPrime.IsLiesOverAlgebra P Q
hp₁ : Ideal.span {Polynomial.map (algebraMap R P.ResidueField) p} = RingHom.ker (aeval (1 ⊗ₜ[R] x)).toRingHom
hp₂ : R[x] = ⊤
Q' : Ideal (P.Fiber S) := ((PrimeSpectrum.primesOverOrderIsoFiber R S P) ⟨Q, ⋯⟩).asIdeal
this✝² : Q'.LiesOver Q
this✝¹ : Q'.LiesOver P
this✝ : Algebra (Localization.AtPrime Q) (Localization.AtPrime Q') := Localization.AtPrime.algebraOfLiesOver Q Q'
this : Algebra (Localization.AtPrime P) (Localization.AtPrime Q') := Localization.AtPrime.algebraOfLiesOver P Q'
⊢ ¬minpoly P.ResidueField ((algebraMap S Q.ResidueField) x) ^ 2 ∣ Polynomial.map (algebraMap R P.ResidueField) p

Tactic:
have : IsUnramifiedAt P.ResidueField Q' := .residueField P Q _ (Q'.over_def Q)

Goal state after:
R : Type u_1
S : Type u_3
inst✝⁸ : CommRing R
inst✝⁷ : CommRing S
inst✝⁶ : Algebra R S
P : Ideal R
inst✝⁵ : P.IsPrime
Q : Ideal S
inst✝⁴ : Q.IsPrime
inst✝³ : Q.LiesOver P
inst✝² : IsUnramifiedAt R Q
x : S
p : R[X]
inst✝¹ : Algebra (Localization.AtPrime P) (Localization.AtPrime Q)
inst✝ : Localization.AtPrime.IsLiesOverAlgebra P Q
hp₁ : Ideal.span {Polynomial.map (algebraMap R P.ResidueField) p} = RingHom.ker (aeval (1 ⊗ₜ[R] x)).toRingHom
hp₂ : R[x] = ⊤
Q' : Ideal (P.Fiber S) := ((PrimeSpectrum.primesOverOrderIsoFiber R S P) ⟨Q, ⋯⟩).asIdeal
this✝³ : Q'.LiesOver Q
this✝² : Q'.LiesOver P
this✝¹ : Algebra (Localization.AtPrime Q) (Localization.AtPrime Q') := Localization.AtPrime.algebraOfLiesOver Q Q'
this✝ : Algebra (Localization.AtPrime P) (Localization.AtPrime Q') := Localization.AtPrime.algebraOfLiesOver P Q'
this : IsUnramifiedAt P.ResidueField Q'
⊢ ¬minpoly P.ResidueField ((algebraMap S Q.ResidueField) x) ^ 2 ∣ Polynomial.map (algebraMap R P.ResidueField) p