mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.RingTheory.UniqueFactorizationDomain.Multiplicative

Goal state before:
pp: α : Type u_1
inst✝² : CommMonoidWithZero α
inst✝¹ : UniqueFactorizationMonoid α
inst✝ : DecidableEq α
s : Finset α
i : α → ℕ
p : α
hps : p ∉ s
is_prime : ∀ q ∈ insert p s, Prime q
is_coprime : ∀ q ∈ insert p s, ∀ q' ∈ insert p s, q ∣ q' → q = q'
hp : Prime p
⊢ ∀ ⦃d : α⦄, d ∣ p ^ i p → d ∣ ∏ p' ∈ s, p' ^ i p' → ¬Prime d

Tactic:
intro d hdp hdprod hd

Goal state after:
α : Type u_1
inst✝² : CommMonoidWithZero α
inst✝¹ : UniqueFactorizationMonoid α
inst✝ : DecidableEq α
s : Finset α
i : α → ℕ
p : α
hps : p ∉ s
is_prime : ∀ q ∈ insert p s, Prime q
is_coprime : ∀ q ∈ insert p s, ∀ q' ∈ insert p s, q ∣ q' → q = q'
hp : Prime p
d : α
hdp : d ∣ p ^ i p
hdprod : d ∣ ∏ p' ∈ s, p' ^ i p'
hd : Prime d
⊢ False
Module: Mathlib.RingTheory.Norm.Basic

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝⁴ : CommRing R
inst✝³ : Ring S
inst✝² : Algebra R S
F : Type u_6
inst✝¹ : Field F
inst✝ : Algebra R F
pb : PowerBasis R S
hE : (Polynomial.map (algebraMap R F) (minpoly R pb.gen)).Splits
hfx : IsSeparable R pb.gen
this : DecidableEq F := Classical.decEq F
⊢ ∀ (x : S →ₐ[R] F), x pb.gen = ↑(pb.liftEquiv' x)

Tactic:
intro σ

Goal state after:
R : Type u_1
S : Type u_2
inst✝⁴ : CommRing R
inst✝³ : Ring S
inst✝² : Algebra R S
F : Type u_6
inst✝¹ : Field F
inst✝ : Algebra R F
pb : PowerBasis R S
hE : (Polynomial.map (algebraMap R F) (minpoly R pb.gen)).Splits
hfx : IsSeparable R pb.gen
this : DecidableEq F := Classical.decEq F
σ : S →ₐ[R] F
⊢ σ pb.gen = ↑(pb.liftEquiv' σ)
Module: Mathlib.RingTheory.Norm.Basic

Goal state before:
pp: K : Type u_4
L : Type u_5
F : Type u_6
inst✝¹¹ : Field K
inst✝¹⁰ : Field L
inst✝⁹ : Field F
inst✝⁸ : Algebra K L
inst✝⁷ : Algebra K F
E : Type u_7
inst✝⁶ : Field E
inst✝⁵ : Algebra K E
inst✝⁴ : Algebra L F
inst✝³ : IsScalarTower K L F
inst✝² : IsAlgClosed E
inst✝¹ : Algebra.IsSeparable K F
inst✝ : FiniteDimensional K F
pb : PowerBasis K L
this✝¹ : FiniteDimensional L F
this✝ : Algebra.IsSeparable L F
this : Fintype (L →ₐ[K] E) := PowerBasis.AlgHom.fintype pb
⊢ ∀ (x : F →ₐ[K] E), x ((algebraMap L F) pb.gen) = (algHomEquivSigma x).fst pb.gen

Tactic:
intro σ

Goal state after:
K : Type u_4
L : Type u_5
F : Type u_6
inst✝¹¹ : Field K
inst✝¹⁰ : Field L
inst✝⁹ : Field F
inst✝⁸ : Algebra K L
inst✝⁷ : Algebra K F
E : Type u_7
inst✝⁶ : Field E
inst✝⁵ : Algebra K E
inst✝⁴ : Algebra L F
inst✝³ : IsScalarTower K L F
inst✝² : IsAlgClosed E
inst✝¹ : Algebra.IsSeparable K F
inst✝ : FiniteDimensional K F
pb : PowerBasis K L
this✝¹ : FiniteDimensional L F
this✝ : Algebra.IsSeparable L F
this : Fintype (L →ₐ[K] E) := PowerBasis.AlgHom.fintype pb
σ : F →ₐ[K] E
⊢ σ ((algebraMap L F) pb.gen) = (algHomEquivSigma σ).fst pb.gen
Module: Mathlib.RingTheory.Ideal.Norm.AbsNorm

Goal state before:
pp: S : Type u_1
inst✝³ : CommRing S
inst✝² : IsDedekindDomain S
inst✝¹ : Free ℤ S
inst✝ : Module.Finite ℤ S
I : Ideal S
⊢ absNorm I ≠ 0 ↔ I ∈ (Ideal S)⁰

Tactic:
ne_eq,

Goal state after:
S : Type u_1
inst✝³ : CommRing S
inst✝² : IsDedekindDomain S
inst✝¹ : Free ℤ S
inst✝ : Module.Finite ℤ S
I : Ideal S
⊢ ¬absNorm I = 0 ↔ I ∈ (Ideal S)⁰
Module: Mathlib.RingTheory.HopkinsLevitzki

Goal state before:
pp: R₀ : Type u_1
R : Type u_2
M✝ : Type u
inst✝¹¹ : Ring R₀
inst✝¹⁰ : Ring R
inst✝⁹ : Module R₀ R
inst✝⁸ : AddCommGroup M✝
inst✝⁷ : Module R₀ M✝
inst✝⁶ : Module R M✝
inst✝⁵ : IsScalarTower R₀ R M✝
inst✝⁴ : IsSemiprimaryRing R
P : (M : Type u) → [inst : AddCommGroup M] → [Module R₀ M] → [Module R M] → Prop
ss : IsSemisimpleRing (R ⧸ Ring.jacobson R)
n : ℕ
Jac : Ideal R := Ring.jacobson R
h0 :
  ∀ (M : Type u) [inst : AddCommGroup M] [inst_1 : Module R₀ M] [inst_2 : Module R M] [IsScalarTower R₀ R M]
    [IsSemisimpleModule R M], Module.IsTorsionBySet R M ↑Jac → P M
h1 :
  ∀ (M : Type u) [inst : AddCommGroup M] [inst_1 : Module R₀ M] [inst_2 : Module R M] [inst_3 : IsScalarTower R₀ R M],
    let N := Jac • ⊤;
    P ↥N → P (M ⧸ N) → P M
hn : Jac ^ n ≤ Module.annihilator R M✝
M : Type u
inst✝³ : AddCommGroup M
inst✝² : Module R₀ M
inst✝¹ : Module R M
inst✝ : IsScalarTower R₀ R M
⊢ ↑Jac ⊆ ↑(Module.annihilator R M) → P M

Tactic:
← Module.isTorsionBySet_iff_subset_annihilator

Goal state after:
R₀ : Type u_1
R : Type u_2
M✝ : Type u
inst✝¹¹ : Ring R₀
inst✝¹⁰ : Ring R
inst✝⁹ : Module R₀ R
inst✝⁸ : AddCommGroup M✝
inst✝⁷ : Module R₀ M✝
inst✝⁶ : Module R M✝
inst✝⁵ : IsScalarTower R₀ R M✝
inst✝⁴ : IsSemiprimaryRing R
P : (M : Type u) → [inst : AddCommGroup M] → [Module R₀ M] → [Module R M] → Prop
ss : IsSemisimpleRing (R ⧸ Ring.jacobson R)
n : ℕ
Jac : Ideal R := Ring.jacobson R
h0 :
  ∀ (M : Type u) [inst : AddCommGroup M] [inst_1 : Module R₀ M] [inst_2 : Module R M] [IsScalarTower R₀ R M]
    [IsSemisimpleModule R M], Module.IsTorsionBySet R M ↑Jac → P M
h1 :
  ∀ (M : Type u) [inst : AddCommGroup M] [inst_1 : Module R₀ M] [inst_2 : Module R M] [inst_3 : IsScalarTower R₀ R M],
    let N := Jac • ⊤;
    P ↥N → P (M ⧸ N) → P M
hn : Jac ^ n ≤ Module.annihilator R M✝
M : Type u
inst✝³ : AddCommGroup M
inst✝² : Module R₀ M
inst✝¹ : Module R M
inst✝ : IsScalarTower R₀ R M
⊢ Module.IsTorsionBySet R M ↑Jac → P M
Module: Mathlib.RingTheory.Spectrum.Prime.Jacobson

Goal state before:
pp: R : Type u_1
inst✝ : CommRing R
H : JacobsonSpace (PrimeSpectrum R)
I : Ideal R
hI : I.IsRadical
⊢ I.jacobson.radical ≤ I.radical

Tactic:
← vanishingIdeal_zeroLocus_eq_radical

Goal state after:
R : Type u_1
inst✝ : CommRing R
H : JacobsonSpace (PrimeSpectrum R)
I : Ideal R
hI : I.IsRadical
⊢ vanishingIdeal (zeroLocus ↑I.jacobson) ≤ vanishingIdeal (zeroLocus ↑I)
Module: Mathlib.Topology.JacobsonSpace

Goal state before:
pp: case mpr
X : Type u_1
inst✝ : TopologicalSpace X
H : ∀ (Z : Set X), Z.Nonempty → IsLocallyClosed Z → (Z ∩ closedPoints X).Nonempty
Z : Set X
hZ : IsClosed[inst✝] Z
H' : ((closure[inst✝] (Z ∩ closedPoints X))ᶜ ∩ Z).Nonempty
this : (closure[inst✝] (Z ∩ closedPoints X))ᶜ ∩ (Z ∩ closedPoints X) ≠ ∅
⊢ False

Tactic:
ne_eq,

Goal state after:
case mpr
X : Type u_1
inst✝ : TopologicalSpace X
H : ∀ (Z : Set X), Z.Nonempty → IsLocallyClosed Z → (Z ∩ closedPoints X).Nonempty
Z : Set X
hZ : IsClosed[inst✝] Z
H' : ((closure[inst✝] (Z ∩ closedPoints X))ᶜ ∩ Z).Nonempty
this : ¬(closure[inst✝] (Z ∩ closedPoints X))ᶜ ∩ (Z ∩ closedPoints X) = ∅
⊢ False
Module: Mathlib.RingTheory.Ideal.Norm.AbsNorm

Goal state before:
pp: S : Type u_1
inst✝⁴ : CommRing S
inst✝³ : IsDedekindDomain S
inst✝² : Free ℤ S
inst✝¹ : Module.Finite ℤ S
n : ℕ
inst✝ : CharZero S
this✝ : Finite { I // I ∈ (Ideal S)⁰ ∧ absNorm I ≤ n }
this : Finite { I // I ∉ (Ideal S)⁰ ∧ absNorm I ≤ n }
e : { I // absNorm I ≤ n } ≃ { I // I ∈ (Ideal S)⁰ ∧ absNorm I ≤ n } ⊕ { I // I ∉ (Ideal S)⁰ ∧ absNorm I ≤ n } :=
  (Equiv.subtypeEquivRight ⋯).trans
    (subtypeOrEquiv (fun I ↦ I ∈ (Ideal S)⁰ ∧ absNorm I ≤ n) (fun I ↦ I ∉ (Ideal S)⁰ ∧ absNorm I ≤ n) ⋯)
I : Ideal S
| ¬absNorm I ≠ 0 ∧ absNorm I ≤ n

Tactic:
ne_eq,

Goal state after:
S : Type u_1
inst✝⁴ : CommRing S
inst✝³ : IsDedekindDomain S
inst✝² : Free ℤ S
inst✝¹ : Module.Finite ℤ S
n : ℕ
inst✝ : CharZero S
this✝ : Finite { I // I ∈ (Ideal S)⁰ ∧ absNorm I ≤ n }
this : Finite { I // I ∉ (Ideal S)⁰ ∧ absNorm I ≤ n }
e : { I // absNorm I ≤ n } ≃ { I // I ∈ (Ideal S)⁰ ∧ absNorm I ≤ n } ⊕ { I // I ∉ (Ideal S)⁰ ∧ absNorm I ≤ n } :=
  (Equiv.subtypeEquivRight ⋯).trans
    (subtypeOrEquiv (fun I ↦ I ∈ (Ideal S)⁰ ∧ absNorm I ≤ n) (fun I ↦ I ∉ (Ideal S)⁰ ∧ absNorm I ≤ n) ⋯)
I : Ideal S
| ¬¬absNorm I = 0 ∧ absNorm I ≤ n
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝³ : CommRing R
S : Type v
inst✝² : CommRing S
inst✝¹ : Algebra R S
p : Ideal R
P : Ideal S
inst✝ : DecidablePred fun n ↦ ∀ (k : ℕ), map f p ≤ P ^ k → k ≤ n
h : ∃ n, ∀ (k : ℕ), map f p ≤ P ^ k → k ≤ n
⊢ p.ramificationIdx' P = Nat.find h

Tactic:
by
  convert! Nat.sSup_def h

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: case neg.mp
R : Type u
inst✝² : CommRing R
S : Type v
inst✝¹ : CommRing S
inst✝ : Algebra R S
p : Ideal R
P : Ideal S
hp : map f p ≤ P
H : ∃ n, ∀ (k : ℕ), map f p ≤ P ^ k → k ≤ n
he : Nat.find H ≠ 1
this✝ : 1 ≤ Nat.find H
this : ∃ k, map f p ≤ P ^ k ∧ 1 < k
⊢ map f p ≤ P ^ 2

Tactic:
obtain ⟨k, hk, h1k⟩ := this

Goal state after:
case neg.mp
R : Type u
inst✝² : CommRing R
S : Type v
inst✝¹ : CommRing S
inst✝ : Algebra R S
p : Ideal R
P : Ideal S
hp : map f p ≤ P
H : ∃ n, ∀ (k : ℕ), map f p ≤ P ^ k → k ≤ n
he : Nat.find H ≠ 1
this : 1 ≤ Nat.find H
k : ℕ
hk : map f p ≤ P ^ k
h1k : 1 < k
⊢ map f p ≤ P ^ 2
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝³ : CommRing R
S : Type v
inst✝² : CommRing S
inst✝¹ : Algebra R S
p : Ideal R
P : Ideal S
inst✝ : IsDedekindDomain S
hp0 : map f p ≠ ⊥
hP : P.IsPrime
hP0 : P ≠ ⊥
⊢ p.ramificationIdx' P = Multiset.count P (normalizedFactors (map f p))

Tactic:
have hPirr := (Ideal.prime_of_isPrime hP0 hP).irreducible

Goal state after:
R : Type u
inst✝³ : CommRing R
S : Type v
inst✝² : CommRing S
inst✝¹ : Algebra R S
p : Ideal R
P : Ideal S
inst✝ : IsDedekindDomain S
hp0 : map f p ≠ ⊥
hP : P.IsPrime
hP0 : P ≠ ⊥
hPirr : Irreducible P
⊢ p.ramificationIdx' P = Multiset.count P (normalizedFactors (map f p))
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝³ : CommRing R
S : Type v
inst✝² : CommRing S
inst✝¹ : Algebra R S
p : Ideal R
P : Ideal S
inst✝ : IsDedekindDomain S
hp0 : map f p ≠ ⊥
hP : P.IsPrime
le : map f p ≤ P
hP0 : P ≠ ⊥
⊢ p.ramificationIdx' P ≠ 0

Tactic:
have hPirr := (Ideal.prime_of_isPrime hP0 hP).irreducible

Goal state after:
R : Type u
inst✝³ : CommRing R
S : Type v
inst✝² : CommRing S
inst✝¹ : Algebra R S
p : Ideal R
P : Ideal S
inst✝ : IsDedekindDomain S
hp0 : map f p ≠ ⊥
hP : P.IsPrime
le : map f p ≤ P
hP0 : P ≠ ⊥
hPirr : Irreducible P
⊢ p.ramificationIdx' P ≠ 0
Module: Mathlib.RingTheory.Unramified.Finite

Goal state before:
pp: case mpr
R : Type u_1
S : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing S
inst✝¹ : Algebra R S
inst✝ : EssFiniteType R S
this : ∀ (t : S ⊗[R] S), (TensorProduct.lmul' R) t = 1 ↔ 1 - t ∈ KaehlerDifferential.ideal R S
t : S ⊗[R] S
ht₁ : ∀ (s : S), (1 ⊗ₜ[R] s - s ⊗ₜ[R] 1) * t = 0
ht₂ : 1 - t ∈ Ideal.span (Set.range fun s ↦ 1 ⊗ₜ[R] s - s ⊗ₜ[R] 1)
⊢ ∃ e, IsIdempotentElem e ∧ Ideal.span (Set.range fun s ↦ 1 ⊗ₜ[R] s - s ⊗ₜ[R] 1) = S ⊗[R] S ∙ e

Tactic:
use 1 - t

Goal state after:
case h
R : Type u_1
S : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing S
inst✝¹ : Algebra R S
inst✝ : EssFiniteType R S
this : ∀ (t : S ⊗[R] S), (TensorProduct.lmul' R) t = 1 ↔ 1 - t ∈ KaehlerDifferential.ideal R S
t : S ⊗[R] S
ht₁ : ∀ (s : S), (1 ⊗ₜ[R] s - s ⊗ₜ[R] 1) * t = 0
ht₂ : 1 - t ∈ Ideal.span (Set.range fun s ↦ 1 ⊗ₜ[R] s - s ⊗ₜ[R] 1)
⊢ IsIdempotentElem (1 - t) ∧ Ideal.span (Set.range fun s ↦ 1 ⊗ₜ[R] s - s ⊗ₜ[R] 1) = S ⊗[R] S ∙ (1 - t)
Module: Mathlib.RingTheory.QuasiFinite.Basic

Goal state before:
pp: R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁸ : CommRing R
inst✝⁷ : CommRing S
inst✝⁶ : CommRing T
inst✝⁵ : Algebra R S
inst✝⁴ : Algebra R T
inst✝³ : Algebra S T
inst✝² : IsScalarTower R S T
inst✝¹ : QuasiFinite R S
inst✝ : QuasiFinite S T
⊢ QuasiFinite R T

Tactic:
refine ⟨fun P hP ↦ ?_⟩
  have : Module.Finite (P.Fiber S) ((P.Fiber S) ⊗[S] T) :=
    iff_of_isArtinianRing.mp inferInstance
  have : Module.Finite P.ResidueField ((P.Fiber S) ⊗[S] T) :=
    .trans (P.Fiber S) _
  let e : P.Fiber S ≃ₐ[S] S ⊗[R] P.ResidueField :=
    { __ := Algebra.TensorProduct.comm _ _ _, commutes' _ := rfl }
  let e' : (P.Fiber S) ⊗[S] T ≃ₐ[R] P.Fiber T :=
    ((Algebra.TensorProduct.congr e .refl).restrictScalars R).trans <|
    ((Algebra.TensorProduct.comm _ _ _).restrictScalars R).trans <|
    ((Algebra.TensorProduct.cancelBaseChange _ _ T _ _).restrictScalars R).trans
    (Algebra.TensorProduct.comm _ _ _)
  let e'' : (P.Fiber S) ⊗[S] T ≃ₐ[P.ResidueField] P.Fiber T :=
    { __ := e', commutes' _ := by simp [e', e] }
  exact .of_surjective e''.toLinearMap e''.surjective

Goal state after:
Module: Mathlib.RingTheory.QuasiFinite.Basic

Goal state before:
pp: R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁹ : CommRing R
inst✝⁸ : CommRing S
inst✝⁷ : CommRing T
inst✝⁶ : Algebra R S
inst✝⁵ : Algebra R T
inst✝⁴ : Algebra S T
inst✝³ : IsScalarTower R S T
inst✝² : Algebra.IsIntegral R S
inst✝¹ : FiniteType R T
s : S
inst✝ : IsLocalization.Away s T
A : Subalgebra R S := R[s]
sA : ↥A := ⟨s, ⋯⟩
f : Localization.Away sA →+* T := IsLocalization.Away.lift sA ⋯
this✝⁶ : Algebra (Localization.Away sA) T := f.toAlgebra
this✝⁵ : Algebra (↥A) (Localization.Away sA) := OreLocalization.instAlgebra
this✝⁴ : SMul (↥A) (Localization.Away sA) := this✝⁵.toSMul
this✝³ : MulAction (↥A) (Localization.Away sA) := toModule.toMulAction
this✝² : IsScalarTower R (↥A) (Localization.Away sA)
this✝¹ : IsScalarTower (↥A) (Localization.Away sA) T
this✝ : IsScalarTower R (Localization.Away sA) T
x : S
n : ℕ
this : IsIntegral (Localization.Away sA) ((algebraMap S T) x)
⊢ (algebraMap S T) x = Localization.Away.invSelf sA ^ n • ((algebraMap S T) x * (algebraMap S T) s ^ n)

Tactic:
trans (sA • Localization.Away.invSelf sA) ^ n • (algebraMap S T x)

Goal state after:
R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁹ : CommRing R
inst✝⁸ : CommRing S
inst✝⁷ : CommRing T
inst✝⁶ : Algebra R S
inst✝⁵ : Algebra R T
inst✝⁴ : Algebra S T
inst✝³ : IsScalarTower R S T
inst✝² : Algebra.IsIntegral R S
inst✝¹ : FiniteType R T
s : S
inst✝ : IsLocalization.Away s T
A : Subalgebra R S := ⋯
sA : ↥A := ⋯
f : Localization.Away sA →+* T := ⋯
this✝⁶ : Algebra (Localization.Away sA) T := ⋯
this✝⁵ : Algebra (↥A) (Localization.Away sA) := ⋯
this✝⁴ : SMul (↥A) (Localization.Away sA) := ⋯
this✝³ : MulAction (↥A) (Localization.Away sA) := ⋯
this✝² : IsScalarTower R (↥A) (Localization.Away sA)
this✝¹ : IsScalarTower (↥A) (Localization.Away sA) T
this✝ : IsScalarTower R (Localization.Away sA) T
x : S
n : ℕ
this : IsIntegral (Localization.Away sA) ((algebraMap S T) x)
⊢ (algebraMap S T) x = (sA • Localization.Away.invSelf sA) ^ n • (algebraMap S T) x

R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁹ : CommRing R
inst✝⁸ : CommRing S
inst✝⁷ : CommRing T
inst✝⁶ : Algebra R S
inst✝⁵ : Algebra R T
inst✝⁴ : Algebra S T
inst✝³ : IsScalarTower R S T
inst✝² : Algebra.IsIntegral R S
inst✝¹ : FiniteType R T
s : S
inst✝ : IsLocalization.Away s T
A : Subalgebra R S := ⋯
sA : ↥A := ⋯
f : Localization.Away sA →+* T := ⋯
this✝⁶ : Algebra (Localization.Away sA) T := ⋯
this✝⁵ : Algebra (↥A) (Localization.Away sA) := ⋯
this✝⁴ : SMul (↥A) (Localization.Away sA) := ⋯
this✝³ : MulAction (↥A) (Localization.Away sA) := ⋯
this✝² : IsScalarTower R (↥A) (Localization.Away sA)
this✝¹ : IsScalarTower (↥A) (Localization.Away sA) T
this✝ : IsScalarTower R (Localization.Away sA) T
x : S
n : ℕ
this : IsIntegral (Localization.Away sA) ((algebraMap S T) x)
⊢ (sA • Localization.Away.invSelf sA) ^ n • (algebraMap S T) x =
    Localization.Away.invSelf sA ^ n • ((algebraMap S T) x * (algebraMap S T) s ^ n)
Module: Mathlib.RingTheory.Smooth.Basic

Goal state before:
pp: R : Type u
A : Type v
inst✝⁵ : CommRing R
inst✝⁴ : CommRing A
inst✝³ : Algebra R A
B : Type u_1
inst✝² : CommRing B
inst✝¹ : Algebra R B
inst✝ : FormallySmooth R A
I : Ideal B
hI : I ^ 2 = ⊥
f : A →ₐ[R] B ⧸ I
P : Generators R A A := Generators.self R A
hP : Function.Injective ⇑P.toExtension.cotangentComplex
l : P.toExtension.CotangentSpace →ₗ[A] P.toExtension.Cotangent
hl : l ∘ₗ P.toExtension.cotangentComplex = LinearMap.id
g : A →ₐ[R] P.Ring ⧸ RingHom.ker (IsScalarTower.toAlgHom R P.Ring A).toRingHom ^ 2
hg : (IsScalarTower.toAlgHom R P.Ring A).kerSquareLift.comp g = AlgHom.id R A
σ : B ⧸ I → B := Function.surjInv ⋯
H : ∀ (x : P.Ring), (Ideal.Quotient.mk I) ((aeval (σ ∘ ⇑f)) x) = f ((algebraMap P.Ring A) x)
x : P.Ring
hx : x ∈ RingHom.ker (algebraMap P.Ring A)
⊢ x ∈ Ideal.comap (aeval (σ ∘ ⇑f)).toRingHom I

Tactic:
by
        simp_all [← Ideal.Quotient.eq_zero_iff_mem (I := I), -map_aeval]

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

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
M : Type u_3
inst✝⁵ : AddCommGroup M
inst✝⁴ : Module R M
inst✝³ : Module S M
inst✝² : IsScalarTower R S M
inst✝¹ : FormallyUnramified R S
inst✝ : EssFiniteType R S
r : S
m : M
⊢ (TensorProduct.AlgebraTensorModule.map LinearMap.id ((lsmul R R M).toLinearMap.flip m)) (1 ⊗ₜ[R] r * elem R S) =
    r • (TensorProduct.AlgebraTensorModule.map LinearMap.id ((lsmul R R M).toLinearMap.flip m)) (elem R S)

Tactic:
have := one_tmul_sub_tmul_one_mul_elem (R := R) r

Goal state after:
R : Type u_1
S : Type u_2
inst✝⁸ : CommRing R
inst✝⁷ : CommRing S
inst✝⁶ : Algebra R S
M : Type u_3
inst✝⁵ : AddCommGroup M
inst✝⁴ : Module R M
inst✝³ : Module S M
inst✝² : IsScalarTower R S M
inst✝¹ : FormallyUnramified R S
inst✝ : EssFiniteType R S
r : S
m : M
this : (1 ⊗ₜ[R] r - r ⊗ₜ[R] 1) * elem R S = 0
⊢ (TensorProduct.AlgebraTensorModule.map LinearMap.id ((lsmul R R M).toLinearMap.flip m)) (1 ⊗ₜ[R] r * elem R S) =
    r • (TensorProduct.AlgebraTensorModule.map LinearMap.id ((lsmul R R M).toLinearMap.flip m)) (elem R S)
Module: Mathlib.RingTheory.Smooth.Basic

Goal state before:
pp: R : Type u
A : Type v
inst✝⁵ : CommRing R
inst✝⁴ : CommRing A
inst✝³ : Algebra R A
P : Type u_2
inst✝² : CommRing P
inst✝¹ : Algebra R P
inst✝ : FormallySmooth R P
f : P →ₐ[R] A
g : A →ₐ[R] P ⧸ RingHom.ker f.toRingHom ^ 2
h : f.kerSquareLift.comp g = AlgHom.id R A
x : A
⊢ ∃ a, f a = x

Tactic:
obtain ⟨y, hy⟩ := Ideal.Quotient.mk_surjective (g x)

Goal state after:
R : Type u
A : Type v
inst✝⁵ : CommRing R
inst✝⁴ : CommRing A
inst✝³ : Algebra R A
P : Type u_2
inst✝² : CommRing P
inst✝¹ : Algebra R P
inst✝ : FormallySmooth R P
f : P →ₐ[R] A
g : A →ₐ[R] P ⧸ RingHom.ker f.toRingHom ^ 2
h : f.kerSquareLift.comp g = AlgHom.id R A
x : A
y : P
hy : (Ideal.Quotient.mk (RingHom.ker f.toRingHom ^ 2)) y = g x
⊢ ∃ a, f a = x
Module: Mathlib.RingTheory.Unramified.Locus

Goal state before:
pp: R : Type u_1
A : Type u_2
inst✝² : CommRing R
inst✝¹ : CommRing A
inst✝ : Algebra R A
f : A
⊢ ↑(PrimeSpectrum.basicOpen f) ⊆ unramifiedLocus R A ↔ FormallyUnramified R (Localization.Away f)

Tactic:
by
  rw [unramifiedLocus_eq_compl_support, Set.subset_compl_comm,
    PrimeSpectrum.basicOpen_eq_zeroLocus_compl, compl_compl,
    ← LocalizedModule.subsingleton_iff_support_subset, Algebra.formallyUnramified_iff]
  exact (IsLocalizedModule.iso (.powers f)
    (KaehlerDifferential.map R R A (Localization.Away f))).subsingleton_congr

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

Goal state before:
pp: R : Type u_1
P : Type u_2
S : Type u_3
inst✝⁶ : CommRing R
inst✝⁵ : CommRing P
inst✝⁴ : CommRing S
inst✝³ : Algebra R P
inst✝² : Algebra P S
l : S ⊗[P] Ω[P⁄R] →ₗ[P] ↥(RingHom.ker (algebraMap P S))
hl : l ∘ₗ kerToTensor R P S = LinearMap.id
σ : S → P
hσ : ∀ (x : S), (algebraMap P S) (σ x) = x
inst✝¹ : Algebra R S
inst✝ : IsScalarTower R P S
hf' : RingHom.ker (algebraMap P S) ^ 2 = ⊥
a b : S
⊢ σ (a * b) - ↑(l (1 ⊗ₜ[P] (D R P) (σ (a * b)))) =
    (σ a - ↑(l (1 ⊗ₜ[P] (D R P) (σ a)))) * (σ b - ↑(l (1 ⊗ₜ[P] (D R P) (σ b))))

Tactic:
by
    have (x y : _) : (l x).1 * (l y).1 = 0 := by
      rw [← Ideal.mem_bot, ← hf', pow_two]; exact Ideal.mul_mem_mul (l x).2 (l y).2
    simp only [sectionOfRetractionKerToTensorAux_prop l hl (σ (a * b)) (σ a * σ b) (by simp [hσ]),
      Derivation.leibniz, tmul_add, tmul_smul, map_add, map_smul, Submodule.coe_add,
      SetLike.val_smul, smul_eq_mul, mul_sub, sub_mul, this, sub_zero]
    ring

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

Goal state before:
pp: case e_f
K : Type u_1
A : Type u_2
inst✝⁶ : Field K
inst✝⁵ : CommRing A
inst✝⁴ : Algebra K A
inst✝³ : FormallyUnramified K A
inst✝² : EssFiniteType K A
inst✝¹ : IsAlgClosed K
inst✝ : IsLocalRing A
this✝ : Module.Finite K A
this : IsArtinianRing A
hA : IsNilpotent (IsLocalRing.maximalIdeal A)
e : K ≃ₐ[K] A ⧸ IsLocalRing.maximalIdeal A := ⋯
e' : A ⊗[K] (A ⧸ IsLocalRing.maximalIdeal A) ≃ₐ[A] A := ⋯
f : A ⧸ IsLocalRing.maximalIdeal A →ₗ[A] A := ⋯
⊢ ↑K ((ofId A (A ⧸ IsLocalRing.maximalIdeal A)).toLinearMap ∘ₗ e'.toLinearMap) =
    ↑K (TensorProduct.AlgebraTensorModule.lift (↑K (lsmul A A (A ⧸ IsLocalRing.maximalIdeal A)).toLinearMap.flip).flip)

Tactic:
apply _root_.TensorProduct.ext'

Goal state after:
case e_f
K : Type u_1
A : Type u_2
inst✝⁶ : Field K
inst✝⁵ : CommRing A
inst✝⁴ : Algebra K A
inst✝³ : FormallyUnramified K A
inst✝² : EssFiniteType K A
inst✝¹ : IsAlgClosed K
inst✝ : IsLocalRing A
this✝ : Module.Finite K A
this : IsArtinianRing A
hA : IsNilpotent (IsLocalRing.maximalIdeal A)
e : K ≃ₐ[K] A ⧸ IsLocalRing.maximalIdeal A := ⋯
e' : A ⊗[K] (A ⧸ IsLocalRing.maximalIdeal A) ≃ₐ[A] A := ⋯
f : A ⧸ IsLocalRing.maximalIdeal A →ₗ[A] A := ⋯
⊢ ∀ (x : A) (y : A ⧸ IsLocalRing.maximalIdeal A),
    (↑K ((ofId A (A ⧸ IsLocalRing.maximalIdeal A)).toLinearMap ∘ₗ e'.toLinearMap)) (x ⊗ₜ[K] y) =
      (↑K
          (TensorProduct.AlgebraTensorModule.lift
            (↑K (lsmul A A (A ⧸ IsLocalRing.maximalIdeal A)).toLinearMap.flip).flip))
        (x ⊗ₜ[K] y)
Module: Mathlib.RingTheory.Smooth.Kaehler

Goal state before:
pp: R : Type u_1
P : Type u_2
S : Type u_3
inst✝⁶ : CommRing R
inst✝⁵ : CommRing P
inst✝⁴ : CommRing S
inst✝³ : Algebra R P
inst✝² : Algebra P S
inst✝¹ : Algebra R S
inst✝ : IsScalarTower R P S
hf' : RingHom.ker (algebraMap P S) ^ 2 = ⊥
hf : Surjective ⇑(algebraMap P S)
l : { l // l ∘ₗ kerToTensor R P S = LinearMap.id }
p s : P
x y : S ⊗[P] Ω[P⁄R]
⊢ ↑(↑l x) * ↑(↑l y) ∈ RingHom.ker (algebraMap P S) * RingHom.ker (algebraMap P S)

Tactic:
exact Ideal.mul_mem_mul (l.1 x).2 (l.1 y).2

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

Goal state before:
pp: K : Type u_1
A : Type u_2
inst✝⁶ : Field K
inst✝⁵ : CommRing A
inst✝⁴ : Algebra K A
inst✝³ : FormallyUnramified K A
inst✝² : EssFiniteType K A
inst✝¹ : IsAlgClosed K
inst✝ : IsLocalRing A
this✝ : Module.Finite K A
this : IsArtinianRing A
hA : IsNilpotent (IsLocalRing.maximalIdeal A)
e : K ≃ₐ[K] A ⧸ IsLocalRing.maximalIdeal A :=
  let __spread.0 := ofId K (A ⧸ IsLocalRing.maximalIdeal A);
  let __spread.1 := Equiv.ofBijective ⇑(algebraMap K (A ⧸ IsLocalRing.maximalIdeal A)) ⋯;
  { toFun := (↑↑__spread.0.toRingHom).toFun, invFun := __spread.1.invFun, left_inv := ⋯, right_inv := ⋯, map_mul' := ⋯,
    map_add' := ⋯, commutes' := ⋯ }
e' : A ⊗[K] (A ⧸ IsLocalRing.maximalIdeal A) ≃ₐ[A] A :=
  (TensorProduct.congr AlgEquiv.refl e.symm).trans (TensorProduct.rid K A A)
f : A ⧸ IsLocalRing.maximalIdeal A →ₗ[A] A := e'.toLinearMap ∘ₗ sec K A (A ⧸ IsLocalRing.maximalIdeal A)
hf : (ofId A (A ⧸ IsLocalRing.maximalIdeal A)).toLinearMap ∘ₗ f = LinearMap.id
hf₁ : f 1 • 1 = 1
hf₂ : 1 - f 1 ∈ IsLocalRing.maximalIdeal A
⊢ f (f 1 • 1) = f 1

Tactic:
hf₁

Goal state after:
K : Type u_1
A : Type u_2
inst✝⁶ : Field K
inst✝⁵ : CommRing A
inst✝⁴ : Algebra K A
inst✝³ : FormallyUnramified K A
inst✝² : EssFiniteType K A
inst✝¹ : IsAlgClosed K
inst✝ : IsLocalRing A
this✝ : Module.Finite K A
this : IsArtinianRing A
hA : IsNilpotent (IsLocalRing.maximalIdeal A)
e : K ≃ₐ[K] A ⧸ IsLocalRing.maximalIdeal A :=
  let __spread.0 := ofId K (A ⧸ IsLocalRing.maximalIdeal A);
  let __spread.1 := Equiv.ofBijective ⇑(algebraMap K (A ⧸ IsLocalRing.maximalIdeal A)) ⋯;
  { toFun := (↑↑__spread.0.toRingHom).toFun, invFun := __spread.1.invFun, left_inv := ⋯, right_inv := ⋯, map_mul' := ⋯,
    map_add' := ⋯, commutes' := ⋯ }
e' : A ⊗[K] (A ⧸ IsLocalRing.maximalIdeal A) ≃ₐ[A] A :=
  (TensorProduct.congr AlgEquiv.refl e.symm).trans (TensorProduct.rid K A A)
f : A ⧸ IsLocalRing.maximalIdeal A →ₗ[A] A := e'.toLinearMap ∘ₗ sec K A (A ⧸ IsLocalRing.maximalIdeal A)
hf : (ofId A (A ⧸ IsLocalRing.maximalIdeal A)).toLinearMap ∘ₗ f = LinearMap.id
hf₁ : f 1 • 1 = 1
hf₂ : 1 - f 1 ∈ IsLocalRing.maximalIdeal A
⊢ f 1 = f 1