mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.RingTheory.Spectrum.Prime.Noetherian

Goal state before:
pp: case refine_2
R : Type u_1
inst✝² : CommRing R
inst✝¹ : IsArtinianRing R
p : Ideal R
inst✝ : p.IsPrime
r : R
hr : (toPiLocalization R) r = Pi.single { asIdeal := p, isPrime := ⋯ } 1
this : (algebraMap R (Localization p.primeCompl)) r = 1
⊢ IsIdempotentElem r

Tactic:
apply PrimeSpectrum.toPiLocalization_bijective.injective
    simp [map_mul, hr, ← Pi.single_mul]

Goal state after:
Module: Mathlib.RingTheory.Ideal.Norm.AbsNorm

Goal state before:
pp: case hJ
S : Type u_1
inst✝² : CommRing S
inst✝¹ : IsDedekindDomain S
inst✝ : Free ℤ S
I : Ideal S
hI : Nat.Prime (absNorm I)
this : (span {↑(absNorm I)}).IsPrime
⊢ comap (algebraMap ℤ S) I ≠ ⊤

Tactic:
exact ((isPrime_of_irreducible_absNorm
      ((Nat.irreducible_iff_nat_prime _).mpr hI)).comap (algebraMap ℤ S)).ne_top

Goal state after:
Module: Mathlib.RingTheory.Ideal.IdempotentFG

Goal state before:
pp: case mpr
R : Type u_1
inst✝¹ : CommRing R
inst✝ : IsDomain R
I : Ideal R
h : I.FG
⊢ I = ⊥ ∨ I = ⊤ → IsIdempotentElem I

Tactic:
· rintro (rfl | rfl) <;> simp [IsIdempotentElem]

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

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
inst✝ : EssFiniteType R S
this : ∀ (t : S ⊗[R] S), (TensorProduct.lmul' R) t = 1 ↔ 1 - t ∈ KaehlerDifferential.ideal R S
⊢ (∃ e, IsIdempotentElem e ∧ KaehlerDifferential.ideal R S = S ⊗[R] S ∙ e) ↔
    ∃ t, (∀ (s : S), (1 ⊗ₜ[R] s - s ⊗ₜ[R] 1) * t = 0) ∧ 1 - t ∈ KaehlerDifferential.ideal R S

Tactic:
← KaehlerDifferential.span_range_eq_ideal

Goal state after:
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
⊢ (∃ e, IsIdempotentElem e ∧ Ideal.span (Set.range fun s ↦ 1 ⊗ₜ[R] s - s ⊗ₜ[R] 1) = S ⊗[R] S ∙ e) ↔
    ∃ t, (∀ (s : S), (1 ⊗ₜ[R] s - s ⊗ₜ[R] 1) * t = 0) ∧ 1 - t ∈ Ideal.span (Set.range fun s ↦ 1 ⊗ₜ[R] s - s ⊗ₜ[R] 1)
Module: Mathlib.RingTheory.QuasiFinite.Basic

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
inst✝ : QuasiFinite R S
I : Ideal R
h : ¬I.IsPrime
⊢ I.primesOver S = ∅

Tactic:
by_contra!

Goal state after:
R : Type u_1
S : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing S
inst✝¹ : Algebra R S
inst✝ : QuasiFinite R S
I : Ideal R
h : ¬I.IsPrime
this : (I.primesOver S).Nonempty
⊢ False
Module: Mathlib.RingTheory.Etale.Basic

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
⊢ Algebra.FormallyEtale R S ↔ Algebra.FormallyEtale R S

Tactic:
toAlgebra_algebraMap

Goal state after:
R : Type u_1
S : Type u_2
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
⊢ Algebra.FormallyEtale R S ↔ Algebra.FormallyEtale R S
Module: Mathlib.RingTheory.Kaehler.JacobiZariski

Goal state before:
pp: case h2
R : Type u₁
S : Type u₂
inst✝⁶ : CommRing R
inst✝⁵ : CommRing S
inst✝⁴ : Algebra R S
T : Type u₃
inst✝³ : CommRing T
inst✝² : Algebra R T
inst✝¹ : Algebra S T
inst✝ : IsScalarTower R S T
ι : Type w₁
σ : Type w₂
Q : Generators S T ι
P : Generators R S σ
x : (Q.comp P).Ring
hx' : x ∈ (Q.comp P).toExtension.ker
y : (Q.comp P).Ring
hy : y ∈ (Q.comp P).ker * (Q.comp P).ker
e : x - y ∈ Ideal.map (Q.toComp P).toAlgHom P.ker
z : ↥(Q.comp P).ker := ⟨x - y, ⋯⟩
hz : ↑z ∈ Ideal.map (Q.toComp P).toAlgHom.toRingHom P.ker
this : Extension.Cotangent.mk ⟨x, hx'⟩ = Extension.Cotangent.mk z
w : P.Ring
hw : w ∈ P.ker
⊢ ∃ (x : (Q.toComp P).toAlgHom w ∈ (Q.comp P).toExtension.ker),
    Extension.Cotangent.mk ⟨(Q.toComp P).toAlgHom w, ⋯⟩ ∈
      Submodule.span T ↑(Extension.Cotangent.map (Q.toComp P).toExtensionHom).range

Tactic:
refine ⟨?_, Submodule.subset_span ⟨Extension.Cotangent.mk ⟨w, hw⟩, ?_⟩⟩

Goal state after:
case h2.refine_1
R : Type u₁
S : Type u₂
inst✝⁶ : CommRing R
inst✝⁵ : CommRing S
inst✝⁴ : Algebra R S
T : Type u₃
inst✝³ : CommRing T
inst✝² : Algebra R T
inst✝¹ : Algebra S T
inst✝ : IsScalarTower R S T
ι : Type w₁
σ : Type w₂
Q : Generators S T ι
P : Generators R S σ
x : (Q.comp P).Ring
hx' : x ∈ (Q.comp P).toExtension.ker
y : (Q.comp P).Ring
hy : y ∈ (Q.comp P).ker * (Q.comp P).ker
e : x - y ∈ Ideal.map (Q.toComp P).toAlgHom P.ker
z : ↥(Q.comp P).ker := ⟨x - y, ⋯⟩
hz : ↑z ∈ Ideal.map (Q.toComp P).toAlgHom.toRingHom P.ker
this : Extension.Cotangent.mk ⟨x, hx'⟩ = Extension.Cotangent.mk z
w : P.Ring
hw : w ∈ P.ker
⊢ (Q.toComp P).toAlgHom w ∈ (Q.comp P).toExtension.ker

case h2.refine_2
R : Type u₁
S : Type u₂
inst✝⁶ : CommRing R
inst✝⁵ : CommRing S
inst✝⁴ : Algebra R S
T : Type u₃
inst✝³ : CommRing T
inst✝² : Algebra R T
inst✝¹ : Algebra S T
inst✝ : IsScalarTower R S T
ι : Type w₁
σ : Type w₂
Q : Generators S T ι
P : Generators R S σ
x : (Q.comp P).Ring
hx' : x ∈ (Q.comp P).toExtension.ker
y : (Q.comp P).Ring
hy : y ∈ (Q.comp P).ker * (Q.comp P).ker
e : x - y ∈ Ideal.map (Q.toComp P).toAlgHom P.ker
z : ↥(Q.comp P).ker := ⟨x - y, ⋯⟩
hz : ↑z ∈ Ideal.map (Q.toComp P).toAlgHom.toRingHom P.ker
this : Extension.Cotangent.mk ⟨x, hx'⟩ = Extension.Cotangent.mk z
w : P.Ring
hw : w ∈ P.ker
⊢ (Extension.Cotangent.map (Q.toComp P).toExtensionHom) (Extension.Cotangent.mk ⟨w, hw⟩) =
    Extension.Cotangent.mk ⟨(Q.toComp P).toAlgHom w, ⋯⟩
Module: Mathlib.RingTheory.Smooth.Basic

Goal state before:
pp: case refine_2
R✝ : Type u
A✝ : Type v
inst✝¹⁴ : CommRing R✝
inst✝¹³ : CommRing A✝
inst✝¹² : Algebra R✝ A✝
B✝ : Type u_1
P : Type u_2
C✝ : Type u_3
inst✝¹¹ : CommRing B✝
inst✝¹⁰ : Algebra R✝ B✝
inst✝⁹ : CommRing C✝
inst✝⁸ : Algebra R✝ C✝
inst✝⁷ : CommRing P
inst✝⁶ : Algebra R✝ P
R : Type u_4
inst✝⁵ : CommRing R
A : Type u_5
inst✝⁴ : CommRing A
inst✝³ : Algebra R A
B : Type u_6
inst✝² : CommRing B
inst✝¹ : Algebra R B
inst✝ : FormallySmooth R A
C : Type (max u_5 u_6)
x✝¹ : CommRing C
x✝ : Algebra B C
I : Ideal C
hI : I ^ 2 = ⊥
f : B ⊗[R] A →ₐ[B] C ⧸ I
this✝ : Algebra R C := ((algebraMap B C).comp (algebraMap R B)).toAlgebra
this : IsScalarTower R B C
b : B
⊢ ∀ (b_1 : A),
    (AlgHom.restrictScalars R
          ((Ideal.Quotient.mkₐ B I).comp
            (TensorProduct.productLeftAlgHom (ofId B C)
              (lift I ⋯ ((AlgHom.restrictScalars R f).comp TensorProduct.includeRight)))))
        (b ⊗ₜ[R] b_1) =
      (AlgHom.restrictScalars R f) (b ⊗ₜ[R] b_1)

Tactic:
a

Goal state after:
case refine_2
R✝ : Type u
A✝ : Type v
inst✝¹⁴ : CommRing R✝
inst✝¹³ : CommRing A✝
inst✝¹² : Algebra R✝ A✝
B✝ : Type u_1
P : Type u_2
C✝ : Type u_3
inst✝¹¹ : CommRing B✝
inst✝¹⁰ : Algebra R✝ B✝
inst✝⁹ : CommRing C✝
inst✝⁸ : Algebra R✝ C✝
inst✝⁷ : CommRing P
inst✝⁶ : Algebra R✝ P
R : Type u_4
inst✝⁵ : CommRing R
A : Type u_5
inst✝⁴ : CommRing A
inst✝³ : Algebra R A
B : Type u_6
inst✝² : CommRing B
inst✝¹ : Algebra R B
inst✝ : FormallySmooth R A
C : Type (max u_5 u_6)
x✝¹ : CommRing C
x✝ : Algebra B C
I : Ideal C
hI : I ^ 2 = ⊥
f : B ⊗[R] A →ₐ[B] C ⧸ I
this✝ : Algebra R C := ((algebraMap B C).comp (algebraMap R B)).toAlgebra
this : IsScalarTower R B C
b : B
a : A
⊢ (AlgHom.restrictScalars R
        ((Ideal.Quotient.mkₐ B I).comp
          (TensorProduct.productLeftAlgHom (ofId B C)
            (lift I ⋯ ((AlgHom.restrictScalars R f).comp TensorProduct.includeRight)))))
      (b ⊗ₜ[R] a) =
    (AlgHom.restrictScalars R f) (b ⊗ₜ[R] a)
Module: Mathlib.RingTheory.Smooth.Basic

Goal state before:
pp: R : Type u_4
A : Type u_5
Rₘ : Type u_6
Sₘ : Type u_7
inst✝¹³ : CommRing R
inst✝¹² : CommRing A
inst✝¹¹ : CommRing Rₘ
inst✝¹⁰ : CommRing Sₘ
M : Submonoid R
inst✝⁹ : Algebra R A
inst✝⁸ : Algebra R Sₘ
inst✝⁷ : Algebra A Sₘ
inst✝⁶ : Algebra R Rₘ
inst✝⁵ : Algebra Rₘ Sₘ
inst✝⁴ : IsScalarTower R Rₘ Sₘ
inst✝³ : IsScalarTower R A Sₘ
inst✝² : IsLocalization M Rₘ
inst✝¹ : IsLocalization (Submonoid.map (algebraMap R A) M) Sₘ
inst✝ : FormallySmooth R A
⊢ FormallySmooth Rₘ Sₘ

Tactic:
have : FormallySmooth A Sₘ := FormallySmooth.of_isLocalization (M.map (algebraMap R A))

Goal state after:
R : Type u_4
A : Type u_5
Rₘ : Type u_6
Sₘ : Type u_7
inst✝¹³ : CommRing R
inst✝¹² : CommRing A
inst✝¹¹ : CommRing Rₘ
inst✝¹⁰ : CommRing Sₘ
M : Submonoid R
inst✝⁹ : Algebra R A
inst✝⁸ : Algebra R Sₘ
inst✝⁷ : Algebra A Sₘ
inst✝⁶ : Algebra R Rₘ
inst✝⁵ : Algebra Rₘ Sₘ
inst✝⁴ : IsScalarTower R Rₘ Sₘ
inst✝³ : IsScalarTower R A Sₘ
inst✝² : IsLocalization M Rₘ
inst✝¹ : IsLocalization (Submonoid.map (algebraMap R A) M) Sₘ
inst✝ : FormallySmooth R A
this : FormallySmooth A Sₘ
⊢ FormallySmooth Rₘ Sₘ
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
⊢ 1 - 1 = 0

Tactic:
sub_self

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
⊢ 0 = 0
Module: Mathlib.RingTheory.Unramified.Field

Goal state before:
pp: K : Type u_1
L : Type u_3
inst✝⁵ : Field K
inst✝⁴ : Field L
inst✝³ : Algebra K L
inst✝² : FormallyUnramified K L
inst✝¹ : EssFiniteType K L
inst✝ : IsPurelyInseparable K L
this✝ : Nontrivial (L ⊗[K] L)
x : L
a✝ : x ∈ ⊤
n : ℕ
this : ExpChar (L ⊗[K] L) (ringExpChar K)
r : K
hr : (algebraMap K L) r = x ^ ringExpChar K ^ n
⊢ 1 ⊗ₜ[K] (r • 1) - 1 ⊗ₜ[K] (r • 1) = 0

Tactic:
sub_self

Goal state after:
K : Type u_1
L : Type u_3
inst✝⁵ : Field K
inst✝⁴ : Field L
inst✝³ : Algebra K L
inst✝² : FormallyUnramified K L
inst✝¹ : EssFiniteType K L
inst✝ : IsPurelyInseparable K L
this✝ : Nontrivial (L ⊗[K] L)
x : L
a✝ : x ∈ ⊤
n : ℕ
this : ExpChar (L ⊗[K] L) (ringExpChar K)
r : K
hr : (algebraMap K L) r = x ^ ringExpChar K ^ n
⊢ 0 = 0
Module: Mathlib.RingTheory.Unramified.Field

Goal state before:
pp: K : Type u_1
L : Type u_3
inst✝⁵ : Field K
inst✝⁴ : Field L
inst✝³ : Algebra K L
inst✝² : FormallyUnramified K L
inst✝¹ : EssFiniteType K L
inst✝ : IsPurelyInseparable K L
this✝¹ : Nontrivial (L ⊗[K] L)
x : L
a✝ : x ∈ ⊤
n : ℕ
hn : x ^ ringExpChar K ^ n ∈ (algebraMap K L).range
this✝ : ExpChar (L ⊗[K] L) (ringExpChar K)
this : (1 ⊗ₜ[K] x - x ⊗ₜ[K] 1) ^ ringExpChar K ^ n = 0
H : 1 ⊗ₜ[K] x = x ⊗ₜ[K] 1
a b : K
e : a • 1 + b • x = 0
hab : a = 0 → ¬b = 0
⊢ IsUnit b

Tactic:
rw [isUnit_iff_ne_zero]

Goal state after:
K : Type u_1
L : Type u_3
inst✝⁵ : Field K
inst✝⁴ : Field L
inst✝³ : Algebra K L
inst✝² : FormallyUnramified K L
inst✝¹ : EssFiniteType K L
inst✝ : IsPurelyInseparable K L
this✝¹ : Nontrivial (L ⊗[K] L)
x : L
a✝ : x ∈ ⊤
n : ℕ
hn : x ^ ringExpChar K ^ n ∈ (algebraMap K L).range
this✝ : ExpChar (L ⊗[K] L) (ringExpChar K)
this : (1 ⊗ₜ[K] x - x ⊗ₜ[K] 1) ^ ringExpChar K ^ n = 0
H : 1 ⊗ₜ[K] x = x ⊗ₜ[K] 1
a b : K
e : a • 1 + b • x = 0
hab : a = 0 → ¬b = 0
⊢ b ≠ 0
Module: Mathlib.RingTheory.Etale.Kaehler

Goal state before:
pp: R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁶ : CommRing R
inst✝⁵ : CommRing S
inst✝⁴ : CommRing T
inst✝³ : Algebra R S
inst✝² : Algebra R T
inst✝¹ : Algebra S T
inst✝ : IsScalarTower R S T
P : Extension R S
Q : Extension R T
f : P.Hom Q
alg : Algebra P.Ring Q.Ring
halg : algebraMap P.Ring Q.Ring = f.toRingHom
H : Function.Bijective ⇑(LinearMap.liftBaseChange Q.Ring (f.mapKer halg))
this✝¹ : Algebra P.Ring T := ⋯
this✝ : IsScalarTower P.Ring S T
this : IsScalarTower P.Ring Q.Ring T
e : Q.Ring ⊗[P.Ring] ↥P.ker ≃ₗ[Q.Ring] ↥Q.ker := ⋯
f' : ↥Q.ker →ₗ[Q.Ring] T ⊗[S] P.Cotangent := ⋯
a : Q.Ring
b : ↥P.ker
c : Q.Ring
d : ↥P.ker
⊢ (↑b • Cotangent.mk d).val = Cotangent.val 0

Tactic:
simp [Cotangent.smul_eq_zero_of_mem _ b.2]

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

Goal state before:
pp: R : Type u_1
S : Type u_3
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
P : Extension R S
x : ↥P.ker
hx : (map P.toInfinitesimal) (mk x) = 0
⊢ ↑x ∈ P.ker ^ 2

Tactic:
apply_fun Cotangent.val at hx

Goal state after:
R : Type u_1
S : Type u_3
inst✝² : CommRing R
inst✝¹ : CommRing S
inst✝ : Algebra R S
P : Extension R S
x : ↥P.ker
hx : ((map P.toInfinitesimal) (mk x)).val = val 0
⊢ ↑x ∈ P.ker ^ 2
Module: Mathlib.RingTheory.Unramified.LocalRing

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 : EssFiniteType R S
p : Ideal R
inst✝⁴ : p.IsPrime
q : Ideal S
inst✝³ : q.IsPrime
inst✝² : q.LiesOver p
inst✝¹ : Algebra (Localization.AtPrime p) (Localization.AtPrime q)
inst✝ : Localization.AtPrime.IsLiesOverAlgebra p q
this : EssFiniteType (Localization.AtPrime p) (Localization.AtPrime q)
⊢ FormallyUnramified (Localization.AtPrime p) (Localization.AtPrime q) ↔
    Algebra.IsSeparable p.ResidueField q.ResidueField ∧
      Ideal.map (algebraMap R (Localization.AtPrime q)) p = maximalIdeal (Localization.AtPrime q)

Tactic:
FormallyUnramified.iff_map_maximalIdeal_eq

Goal state after:
R : Type u_1
S : Type u_2
inst✝⁸ : CommRing R
inst✝⁷ : CommRing S
inst✝⁶ : Algebra R S
inst✝⁵ : EssFiniteType R S
p : Ideal R
inst✝⁴ : p.IsPrime
q : Ideal S
inst✝³ : q.IsPrime
inst✝² : q.LiesOver p
inst✝¹ : Algebra (Localization.AtPrime p) (Localization.AtPrime q)
inst✝ : Localization.AtPrime.IsLiesOverAlgebra p q
this : EssFiniteType (Localization.AtPrime p) (Localization.AtPrime q)
⊢ Algebra.IsSeparable (ResidueField (Localization.AtPrime p)) (ResidueField (Localization.AtPrime q)) ∧
      Ideal.map (algebraMap (Localization.AtPrime p) (Localization.AtPrime q)) (maximalIdeal (Localization.AtPrime p)) =
        maximalIdeal (Localization.AtPrime q) ↔
    Algebra.IsSeparable p.ResidueField q.ResidueField ∧
      Ideal.map (algebraMap R (Localization.AtPrime q)) p = maximalIdeal (Localization.AtPrime q)
Module: Mathlib.RingTheory.Etale.Kaehler

Goal state before:
pp: R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : Algebra R S
inst✝¹ : Algebra R T
inst✝ : Algebra S T
P : Extension R S
Q : Extension R T
f : P.Hom Q
alg : Algebra P.Ring Q.Ring
halg : algebraMap P.Ring Q.Ring = f.toRingHom
H : Function.Bijective ⇑(LinearMap.liftBaseChange Q.Ring (f.mapKer halg))
x : Q.Ring
y : ↥P.ker
this✝¹ : Algebra P.Ring T := ((algebraMap S T).comp (algebraMap P.Ring S)).toAlgebra
this✝ : IsScalarTower P.Ring S T
this : IsScalarTower P.Ring Q.Ring T
e : Q.Ring ⊗[P.Ring] ↥P.ker ≃ₗ[Q.Ring] ↥Q.ker :=
  LinearEquiv.ofBijective (LinearMap.liftBaseChange Q.Ring (f.mapKer halg)) H
⊢ (LinearMap.liftBaseChange Q.Ring (↑P.Ring ((TensorProduct.mk S T P.Cotangent) 1) ∘ₗ Cotangent.mk))
      (e.symm (e (x ⊗ₜ[P.Ring] y))) =
    x • 1 ⊗ₜ[S] Cotangent.mk y

Tactic:
e.symm_apply_apply

Goal state after:
R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : Algebra R S
inst✝¹ : Algebra R T
inst✝ : Algebra S T
P : Extension R S
Q : Extension R T
f : P.Hom Q
alg : Algebra P.Ring Q.Ring
halg : algebraMap P.Ring Q.Ring = f.toRingHom
H : Function.Bijective ⇑(LinearMap.liftBaseChange Q.Ring (f.mapKer halg))
x : Q.Ring
y : ↥P.ker
this✝¹ : Algebra P.Ring T := ((algebraMap S T).comp (algebraMap P.Ring S)).toAlgebra
this✝ : IsScalarTower P.Ring S T
this : IsScalarTower P.Ring Q.Ring T
e : Q.Ring ⊗[P.Ring] ↥P.ker ≃ₗ[Q.Ring] ↥Q.ker :=
  LinearEquiv.ofBijective (LinearMap.liftBaseChange Q.Ring (f.mapKer halg)) H
⊢ (LinearMap.liftBaseChange Q.Ring (↑P.Ring ((TensorProduct.mk S T P.Cotangent) 1) ∘ₗ Cotangent.mk)) (x ⊗ₜ[P.Ring] y) =
    x • 1 ⊗ₜ[S] Cotangent.mk y
Module: Mathlib.RingTheory.Etale.Kaehler

Goal state before:
pp: case left
R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing T
inst✝⁴ : Algebra R S
inst✝³ : Algebra R T
inst✝² : Algebra S T
inst✝¹ : IsScalarTower R S T
P : Extension R S
Q : Extension R T
f : P.Hom Q
alg : Algebra P.Ring Q.Ring
halg : algebraMap P.Ring Q.Ring = f.toRingHom
inst✝ : Module.Flat S T
H₁ : f.toRingHom.FormallyEtale
H₂ : Function.Bijective ⇑(LinearMap.liftBaseChange Q.Ring (f.mapKer halg))
x : T ⊗[S] P.H1Cotangent
hx : (LinearMap.liftBaseChange T (H1Cotangent.map f)) x = 0
⊢ (tensorCotangent f halg H₂) ((LinearMap.lTensor T h1Cotangentι) x) =
    h1Cotangentι ((LinearMap.liftBaseChange T (H1Cotangent.map f)) x)

Tactic:
change ((Cotangent.map f).liftBaseChange T ∘ₗ h1Cotangentι.baseChange T) x =
      (h1Cotangentι ∘ₗ _) x

Goal state after:
case left
R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing T
inst✝⁴ : Algebra R S
inst✝³ : Algebra R T
inst✝² : Algebra S T
inst✝¹ : IsScalarTower R S T
P : Extension R S
Q : Extension R T
f : P.Hom Q
alg : Algebra P.Ring Q.Ring
halg : algebraMap P.Ring Q.Ring = f.toRingHom
inst✝ : Module.Flat S T
H₁ : f.toRingHom.FormallyEtale
H₂ : Function.Bijective ⇑(LinearMap.liftBaseChange Q.Ring (f.mapKer halg))
x : T ⊗[S] P.H1Cotangent
hx : (LinearMap.liftBaseChange T (H1Cotangent.map f)) x = 0
⊢ (LinearMap.liftBaseChange T (Cotangent.map f) ∘ₗ LinearMap.baseChange T h1Cotangentι) x =
    (h1Cotangentι ∘ₗ LinearMap.liftBaseChange T (H1Cotangent.map f)) x
Module: Mathlib.RingTheory.Unramified.LocalRing

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
p : Ideal R
inst✝² : p.IsPrime
q : Ideal S
inst✝¹ : q.IsPrime
inst✝ : q.LiesOver p
H : Function.Injective ⇑(localRingHom p q (algebraMap R S) ⋯)
s : Finset R
hs : Ideal.span ↑s = RingHom.ker (algebraMap R S)
this : ∀ (x : ↥s), (algebraMap R (Localization.AtPrime p)) ↑x = 0
m : ↥s → ↥p.primeCompl
hm : ∀ (x : ↥s), ↑(m x) * ↑x = 0
x : R
hxs : x ∈ ↑s
⊢ ↑(∏ i, m i) * x = 0

Tactic:
rw [Fintype.prod_eq_mul_prod_compl ⟨x, hxs⟩, Submonoid.coe_mul, mul_assoc, mul_left_comm, hm,
      mul_zero]

Goal state after:
Module: Mathlib.LinearAlgebra.Countable

Goal state before:
pp: M : Type u_1
R : Type u_2
inst✝³ : Semiring R
inst✝² : AddCommMonoid M
inst✝¹ : Module R M
hM : Uncountable M
inst✝ : Module.Finite R M
⊢ Uncountable R

Tactic:
by_contra!

Goal state after:
M : Type u_1
R : Type u_2
inst✝³ : Semiring R
inst✝² : AddCommMonoid M
inst✝¹ : Module R M
hM : Uncountable M
inst✝ : Module.Finite R M
this : Countable R
⊢ False
Module: Mathlib.Combinatorics.Enumerative.InclusionExclusion

Goal state before:
pp: case neg
ι : Type u_1
α : Type u_2
G : Type u_3
inst✝ : AddCommGroup G
s : Finset ι
S : ι → Set α
f : α → G
a : α
ha : a ∉ ⋃ i ∈ s, S i
t : Finset ι
⊢ t ⊆ s → t.Nonempty → (-1) ^ #t • (⋂ i ∈ t, S i).indicator f a = 0

Tactic:
hts

Goal state after:
case neg
ι : Type u_1
α : Type u_2
G : Type u_3
inst✝ : AddCommGroup G
s : Finset ι
S : ι → Set α
f : α → G
a : α
ha : a ∉ ⋃ i ∈ s, S i
t : Finset ι
hts : t ⊆ s
⊢ t.Nonempty → (-1) ^ #t • (⋂ i ∈ t, S i).indicator f a = 0
Module: Mathlib.Data.NNReal.Defs

Goal state before:
pp: r : ℝ
⊢ ∃ x, r = ↑x ∨ r = -↑x

Tactic:
obtain (hr | hr) : 0 ≤ r ∨ 0 ≤ -r := by simpa using le_total ..

Goal state after:
case inl
r : ℝ
hr : 0 ≤ r
⊢ ∃ x, r = ↑x ∨ r = -↑x

case inr
r : ℝ
hr : 0 ≤ -r
⊢ ∃ x, r = ↑x ∨ r = -↑x
Module: Mathlib.Analysis.Normed.Group.Seminorm

Goal state before:
pp: case h₁
R : Type u_1
R' : Type u_2
E : Type u_3
F : Type u_4
G : Type u_5
inst✝² : Group E
inst✝¹ : Group F
inst✝ : Group G
p✝ q : GroupSeminorm E
f : F →* E
s : Set (GroupSeminorm E)
h : BddAbove s
x y : E
hs : s.Nonempty
this : Nonempty ↑s
p : ↑s
⊢ ↑p x ≤ ⨆ p, ↑p x

Tactic:
apply le_ciSup (f := (DFunLike.coe · _) ∘ Subtype.val) ?_ p
              simpa [Set.range_comp] using Monotone.map_bddAbove (fun _ _ h' ↦ by exact h' _) h

Goal state after:
Module: Mathlib.Analysis.Normed.Group.Seminorm

Goal state before:
pp: case h₂
R : Type u_1
R' : Type u_2
E : Type u_3
F : Type u_4
G : Type u_5
inst✝² : Group E
inst✝¹ : Group F
inst✝ : Group G
p✝ q : GroupSeminorm E
f : F →* E
s : Set (GroupSeminorm E)
h : BddAbove s
x y : E
hs : s.Nonempty
this : Nonempty ↑s
p : ↑s
⊢ ↑p y ≤ ⨆ p, ↑p y

Tactic:
apply le_ciSup (f := (DFunLike.coe · _) ∘ Subtype.val) ?_ p
              simpa [Set.range_comp] using Monotone.map_bddAbove (fun _ _ h' ↦ by exact h' _) h

Goal state after:
Module: Mathlib.Analysis.Normed.Group.Seminorm

Goal state before:
pp: R : Type u_1
R' : Type u_2
E : Type u_3
F : Type u_4
G : Type u_5
inst✝¹ : CommGroup E
inst✝ : CommGroup F
p✝ q✝ : GroupSeminorm E
x✝ : E
p q : GroupSeminorm E
x y u v : E
⊢ p (u * v) + q (x / u * (y / v)) ≤ p u + p v + (q (x / u) + q (y / v))

Tactic:
exact add_le_add (map_mul_le_add p _ _) (map_mul_le_add q _ _)

Goal state after:
Module: Mathlib.Data.ENNReal.Real

Goal state before:
pp: a : ℝ
b : ℝ≥0
ha : 0 ≤ a
⊢ a < (↑b).toReal ↔ a < ↑b

Tactic:
by rw [coe_toReal]

Goal state after:
Module: Mathlib.Analysis.Normed.Group.Seminorm

Goal state before:
pp: case h₁
R : Type u_1
R' : Type u_2
E : Type u_3
F : Type u_4
G : Type u_5
inst✝ : AddGroup E
p✝ q : NonarchAddGroupSeminorm E
s : Set (NonarchAddGroupSeminorm E)
h : BddAbove s
x y : E
hs : s.Nonempty
this : Nonempty ↑s
p : ↑s
⊢ ↑p x ≤ ⨆ p, ↑p x

Tactic:
apply le_ciSup (f := (DFunLike.coe · _) ∘ Subtype.val) ?_ p
              simpa [Set.range_comp] using Monotone.map_bddAbove (fun _ _ h' ↦ by exact h' _) h

Goal state after:
Module: Mathlib.Analysis.Normed.Group.Seminorm

Goal state before:
pp: case h₂
R : Type u_1
R' : Type u_2
E : Type u_3
F : Type u_4
G : Type u_5
inst✝ : AddGroup E
p✝ q : NonarchAddGroupSeminorm E
s : Set (NonarchAddGroupSeminorm E)
h : BddAbove s
x y : E
hs : s.Nonempty
this : Nonempty ↑s
p : ↑s
⊢ ↑p y ≤ ⨆ p, ↑p y

Tactic:
apply le_ciSup (f := (DFunLike.coe · _) ∘ Subtype.val) ?_ p
              simpa [Set.range_comp] using Monotone.map_bddAbove (fun _ _ h' ↦ by exact h' _) h

Goal state after:
Module: Mathlib.Data.ENNReal.Operations

Goal state before:
pp: a b : ℝ≥0∞
ha₀ : a ≠ 0
ha : a ≠ ∞
⊢ a * b = a ↔ b = 1

Tactic:
simpa using ENNReal.mul_right_inj ha₀ ha (c := 1)

Goal state after:
Module: Mathlib.RingTheory.DedekindDomain.Factorization

Goal state before:
pp: R : Type u_1
inst✝⁴ : CommRing R
K : Type u_2
inst✝³ : Field K
inst✝² : Algebra R K
inst✝¹ : IsFractionRing R K
inst✝ : IsDedekindDomain R
v : HeightOneSpectrum R
h1 : 1 = spanSingleton R⁰ ((algebraMap R K) 1)⁻¹ * ↑1
⊢ ↑((Associates.mk v.asIdeal).count (Associates.mk ⊤).factors) -
      ↑((Associates.mk v.asIdeal).count (Associates.mk ⊤).factors) =
    0

Tactic:
sub_self

Goal state after:
R : Type u_1
inst✝⁴ : CommRing R
K : Type u_2
inst✝³ : Field K
inst✝² : Algebra R K
inst✝¹ : IsFractionRing R K
inst✝ : IsDedekindDomain R
v : HeightOneSpectrum R
h1 : 1 = spanSingleton R⁰ ((algebraMap R K) 1)⁻¹ * ↑1
⊢ 0 = 0
Module: Mathlib.Data.ENNReal.Inv

Goal state before:
pp: a b : ℝ≥0∞
ha₀ : a = 0 → b = 0
ha : a = ∞ → b = 0
⊢ a⁻¹ * (a * b) = b

Tactic:
obtain rfl | ha₀ := eq_or_ne a 0

Goal state after:
case inl
b : ℝ≥0∞
ha₀ : 0 = 0 → b = 0
ha : 0 = ∞ → b = 0
⊢ 0⁻¹ * (0 * b) = b

case inr
a b : ℝ≥0∞
ha₀✝ : a = 0 → b = 0
ha : a = ∞ → b = 0
ha₀ : a ≠ 0
⊢ a⁻¹ * (a * b) = b