mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.RingTheory.Unramified.Pi

Goal state before:
pp: case intro.mpr.hI
R : Type u_1
I : Type u_2
inst✝⁵ : Finite I
f : I → Type u_3
inst✝⁴ : CommRing R
inst✝³ : (i : I) → CommRing (f i)
inst✝² : (i : I) → Algebra R (f i)
val✝ : Fintype I
H✝ : ∀ (i : I), FormallyUnramified R (f i)
B : Type (max u_2 u_3)
inst✝¹ : CommRing B
inst✝ : Algebra R B
J : Ideal B
hJ : J ^ 2 = ⊥
f₁ f₂ : ((i : I) → f i) →ₐ[R] B
e✝ : (Ideal.Quotient.mkₐ R J).comp f₁ = (Ideal.Quotient.mkₐ R J).comp f₂
g : (i : I) → f i
x : I
hf : ∀ (x : (i : I) → f i), f₁ x - f₂ x ∈ J
e : (i : I) → f i := ⋯
he : IsIdempotentElem e
h₁ : f₁ e * (1 - f₂ e) = 0
h₂ : f₂ e * (1 - f₁ e) = 0
H : f₁ e = f₂ e
J' : Ideal B := ⋯
f₁' : f x →ₐ[R] B ⧸ J' := ⋯
f₂' : f x →ₐ[R] B ⧸ J' := ⋯
⊢ Ideal.map (algebraMap B (B ⧸ J')) J ^ 2 = ⊥

pp: case intro.mpr.a
R : Type u_1
I : Type u_2
inst✝⁵ : Finite I
f : I → Type u_3
inst✝⁴ : CommRing R
inst✝³ : (i : I) → CommRing (f i)
inst✝² : (i : I) → Algebra R (f i)
val✝ : Fintype I
H✝ : ∀ (i : I), FormallyUnramified R (f i)
B : Type (max u_2 u_3)
inst✝¹ : CommRing B
inst✝ : Algebra R B
J : Ideal B
hJ : J ^ 2 = ⊥
f₁ f₂ : ((i : I) → f i) →ₐ[R] B
e✝ : (Ideal.Quotient.mkₐ R J).comp f₁ = (Ideal.Quotient.mkₐ R J).comp f₂
g : (i : I) → f i
x : I
hf : ∀ (x : (i : I) → f i), f₁ x - f₂ x ∈ J
e : (i : I) → f i := ⋯
he : IsIdempotentElem e
h₁ : f₁ e * (1 - f₂ e) = 0
h₂ : f₂ e * (1 - f₁ e) = 0
H : f₁ e = f₂ e
J' : Ideal B := ⋯
f₁' : f x →ₐ[R] B ⧸ J' := ⋯
f₂' : f x →ₐ[R] B ⧸ J' := ⋯
⊢ (Ideal.Quotient.mkₐ R (Ideal.map (algebraMap B (B ⧸ J')) J)).comp f₁' =
    (Ideal.Quotient.mkₐ R (Ideal.map (algebraMap B (B ⧸ J')) J)).comp f₂'

Tactic:
· rw [← Ideal.map_pow, hJ, Ideal.map_bot]

Goal state after:
case intro.mpr.a
R : Type u_1
I : Type u_2
inst✝⁵ : Finite I
f : I → Type u_3
inst✝⁴ : CommRing R
inst✝³ : (i : I) → CommRing (f i)
inst✝² : (i : I) → Algebra R (f i)
val✝ : Fintype I
H✝ : ∀ (i : I), FormallyUnramified R (f i)
B : Type (max u_2 u_3)
inst✝¹ : CommRing B
inst✝ : Algebra R B
J : Ideal B
hJ : J ^ 2 = ⊥
f₁ f₂ : ((i : I) → f i) →ₐ[R] B
e✝ : (Ideal.Quotient.mkₐ R J).comp f₁ = (Ideal.Quotient.mkₐ R J).comp f₂
g : (i : I) → f i
x : I
hf : ∀ (x : (i : I) → f i), f₁ x - f₂ x ∈ J
e : (i : I) → f i := ⋯
he : IsIdempotentElem e
h₁ : f₁ e * (1 - f₂ e) = 0
h₂ : f₂ e * (1 - f₁ e) = 0
H : f₁ e = f₂ e
J' : Ideal B := ⋯
f₁' : f x →ₐ[R] B ⧸ J' := ⋯
f₂' : f x →ₐ[R] B ⧸ J' := ⋯
⊢ (Ideal.Quotient.mkₐ R (Ideal.map (algebraMap B (B ⧸ J')) J)).comp f₁' =
    (Ideal.Quotient.mkₐ R (Ideal.map (algebraMap B (B ⧸ J')) J)).comp f₂'
Module: Mathlib.AlgebraicGeometry.EllipticCurve.Projective.Formula

Goal state before:
pp: R : Type r
inst✝ : CommRing R
W' : Projective R
P : Fin 3 → R
hPz : P z = 0
⊢ W'.dblZ P = 0

Tactic:
rw [dblZ, hPz, zero_mul]

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

Goal state before:
pp: case mpr
K : Type u_1
A : Type u
inst✝³ : Field K
inst✝² : CommRing A
inst✝¹ : Algebra K A
inst✝ : EssFiniteType K A
⊢ (∃ I, ∃ (_ : Finite I), ∃ Ai x x_1 x_2, ∀ (i : I), Algebra.IsSeparable K (Ai i)) → FormallyEtale K A

Tactic:
· intro ⟨I, _, Ai, _, _, e, _⟩
    rw [FormallyEtale.iff_of_equiv e, FormallyEtale.pi_iff]
    exact fun I ↦ of_isSeparable K (Ai I)

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

Goal state before:
pp: R : Type u_1
S : Type u_2
P : Type u_3
inst✝¹³ : CommRing R
inst✝¹² : CommRing S
inst✝¹¹ : Algebra R S
inst✝¹⁰ : Module.Flat R S
inst✝⁹ : CommRing P
inst✝⁸ : Algebra R P
inst✝⁷ : Algebra P S
inst✝⁶ : IsScalarTower R P S
inst✝⁵ : IsLocalRing R
inst✝⁴ : IsLocalRing S
inst✝³ : IsLocalHom (algebraMap R S)
inst✝² : FormallySmooth 𝓀[R] (𝓀[R] ⊗[R] S)
M : Submonoid P
inst✝¹ : IsLocalization M S
inst✝ : FinitePresentation R P
n : ℕ
f₀ : MvPolynomial (Fin n) R →ₐ[R] P
hf₀ : Function.Surjective ⇑f₀
M' : Submonoid (MvPolynomial (Fin n) R) := Submonoid.comap f₀ M
P' : Type u_1 := Localization M'
x : ↥M'
⊢ IsUnit (((IsScalarTower.toAlgHom R P S).comp f₀) ↑x)

Tactic:
simpa using IsLocalization.map_units (M := M) _ ⟨f₀ x.1, x.2⟩

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

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 : Module.Flat R S
inst✝⁴ : FinitePresentation R S
p : Ideal R
q : Ideal S
inst✝³ : p.IsPrime
inst✝² : q.IsPrime
inst✝¹ : q.LiesOver p
inst✝ : FormallySmooth p.ResidueField (p.Fiber S)
Rp : Type u_1 := Localization.AtPrime p
Sp : Type u_2 := Localization (algebraMapSubmonoid S p.primeCompl)
Sq : Type u_2 := Localization.AtPrime q
this : Algebra (Localization.AtPrime p) (Localization.AtPrime q) := Localization.AtPrime.algebraOfLiesOver p q
x : R
hx : x ∈ ↑p.primeCompl
⊢ (algebraMap R S) x ∈ q.primeCompl

Tactic:
simp_all [q.over_def p]

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

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 : Module.Flat R S
inst✝⁴ : FinitePresentation R S
p : Ideal R
q : Ideal S
inst✝³ : p.IsPrime
inst✝² : q.IsPrime
inst✝¹ : q.LiesOver p
inst✝ : FormallySmooth p.ResidueField (p.Fiber S)
Rp : Type u_1 := Localization.AtPrime p
Sp : Type u_2 := Localization (algebraMapSubmonoid S p.primeCompl)
Sq : Type u_2 := Localization.AtPrime q
this✝¹ : Algebra (Localization.AtPrime p) (Localization.AtPrime q) := Localization.AtPrime.algebraOfLiesOver p q
f : Sp →ₐ[S] Sq := IsLocalization.liftAlgHom ⋯
algInst✝ : Algebra Sp Sq := f.toAlgebra
this✝ : IsScalarTower R Sp Sq
this : IsScalarTower Rp Sp Sq
x : R
hx : x ∈ ↑p.primeCompl
⊢ (algebraMap R S) x ∈ q.primeCompl

Tactic:
simp_all [q.over_def p]

Goal state after:
Module: Mathlib.RingTheory.AdicCompletion.Functoriality

Goal state before:
pp: R : Type u_1
inst✝⁴ : CommRing R
I : Ideal R
ι : Type u_6
M : ι → Type u_7
inst✝³ : (i : ι) → AddCommGroup (M i)
inst✝² : (i : ι) → Module R (M i)
inst✝¹ : Fintype ι
inst✝ : DecidableEq ι
f : AdicCauchySequence I (⨁ (j : ι), M j)
n : ℕ
⊢ ↑((sum I M) ((sumInv I M) ((mk I (⨁ (j : ι), M j)) f))) n = Submodule.Quotient.mk (↑f n)

Tactic:
rw [← DirectSum.sum_univ_of (((sumInv I M) ((AdicCompletion.mk I (⨁ (j : ι), M j)) f)))]

Goal state after:
R : Type u_1
inst✝⁴ : CommRing R
I : Ideal R
ι : Type u_6
M : ι → Type u_7
inst✝³ : (i : ι) → AddCommGroup (M i)
inst✝² : (i : ι) → Module R (M i)
inst✝¹ : Fintype ι
inst✝ : DecidableEq ι
f : AdicCauchySequence I (⨁ (j : ι), M j)
n : ℕ
⊢ ↑((sum I M) (∑ i, (DirectSum.of (fun i ↦ AdicCompletion I (M i)) i) (((sumInv I M) ((mk I (⨁ (j : ι), M j)) f)) i)))
      n =
    Submodule.Quotient.mk (↑f n)
Module: Mathlib.RingTheory.AdicCompletion.Algebra

Goal state before:
pp: R✝ : Type u_1
S✝ : Type u_2
inst✝⁵ : CommRing R✝
inst✝⁴ : CommRing S✝
I✝ : Ideal R✝
M : Type u_3
inst✝³ : AddCommGroup M
inst✝² : Module R✝ M
R : Type u_4
S : Type u_5
inst✝¹ : NonAssocSemiring R
inst✝ : CommRing S
I : Ideal S
f : (n : ℕ) → R →+* S ⧸ I ^ n
hf : ∀ {m n : ℕ} (hle : m ≤ n), (Ideal.Quotient.factorPow I hle).comp (f n) = f m
x y : R
⊢ ⟨fun n ↦ (factor ⋯) ((f n) (x * y)), ⋯⟩ = ⟨fun n ↦ (factor ⋯) ((f n) x), ⋯⟩ * ⟨fun n ↦ (factor ⋯) ((f n) y), ⋯⟩

Tactic:
by
    simp only [mapQ_eq_factor, factor_eq_factor, map_mul]
    ext; simp

Goal state after:
Module: Mathlib.LinearAlgebra.Basis.Exact

Goal state before:
pp: R : Type u_1
M : Type u_2
K : Type u_3
P : Type u_4
inst✝⁶ : Ring R
inst✝⁵ : AddCommGroup M
inst✝⁴ : AddCommGroup K
inst✝³ : AddCommGroup P
inst✝² : Module R M
inst✝¹ : Module R K
inst✝ : Module R P
f : K →ₗ[R] M
g : M →ₗ[R] P
s : M →ₗ[R] K
hfg : Function.Exact ⇑f ⇑g
ι : Type u_5
κ : Type u_6
v : ι → M
a : κ → ι
hainj : Function.Injective a
hsa : ∀ (i : κ), s (v (a i)) = 0
hli : LinearIndependent R v
y : K
hy : f y ∈ Submodule.span R (Set.range (v ∘ a))
hz : s (f y) = 0
hs : (s ∘ₗ f) y = LinearMap.id y
⊢ f y = 0

Tactic:
simp only [LinearMap.coe_comp, Function.comp_apply, LinearMap.id_coe, id_eq] at hs

Goal state after:
R : Type u_1
M : Type u_2
K : Type u_3
P : Type u_4
inst✝⁶ : Ring R
inst✝⁵ : AddCommGroup M
inst✝⁴ : AddCommGroup K
inst✝³ : AddCommGroup P
inst✝² : Module R M
inst✝¹ : Module R K
inst✝ : Module R P
f : K →ₗ[R] M
g : M →ₗ[R] P
s : M →ₗ[R] K
hfg : Function.Exact ⇑f ⇑g
ι : Type u_5
κ : Type u_6
v : ι → M
a : κ → ι
hainj : Function.Injective a
hsa : ∀ (i : κ), s (v (a i)) = 0
hli : LinearIndependent R v
y : K
hy : f y ∈ Submodule.span R (Set.range (v ∘ a))
hz : s (f y) = 0
hs : s (f y) = y
⊢ f y = 0
Module: Mathlib.LinearAlgebra.Basis.Exact

Goal state before:
pp: case inr
R : Type u_1
M : Type u_2
K : Type u_3
P : Type u_4
inst✝⁶ : Ring R
inst✝⁵ : AddCommGroup M
inst✝⁴ : AddCommGroup K
inst✝³ : AddCommGroup P
inst✝² : Module R M
inst✝¹ : Module R K
inst✝ : Module R P
f : K →ₗ[R] M
g : M →ₗ[R] P
s : M →ₗ[R] K
hfg : Function.Exact ⇑f ⇑g
κ : Type u_6
σ : Type u_7
v : κ ⊕ σ → M
hg : Function.Surjective ⇑g
hslzero : ∀ (i : κ), s (v (Sum.inl i)) = 0
hli : LinearIndependent R (⇑s ∘ v ∘ Sum.inr)
hsp : ⊤ ≤ Submodule.span R (Set.range v)
m : M
this :
  ∀ {R : Type u_1} {M : Type u_2} {K : Type u_3} {P : Type u_4} [inst : Ring R] [inst_1 : AddCommGroup M]
    [inst_2 : AddCommGroup K] [inst_3 : AddCommGroup P] [inst_4 : Module R M] [inst_5 : Module R K]
    [inst_6 : Module R P] {f : K →ₗ[R] M} {g : M →ₗ[R] P} {s : M →ₗ[R] K},
    s ∘ₗ f = LinearMap.id →
      Function.Exact ⇑f ⇑g →
        ∀ {κ : Type u_6} {σ : Type u_7} (v : κ ⊕ σ → M),
          Function.Surjective ⇑g →
            (∀ (i : κ), s (v (Sum.inl i)) = 0) →
              LinearIndependent R (⇑s ∘ v ∘ Sum.inr) →
                ⊤ ≤ Submodule.span R (Set.range v) → ∀ m ∈ s.ker, g m ∈ Submodule.span R (Set.range (⇑g ∘ v ∘ Sum.inl))
h : m ∉ s.ker
x : M := f (s m)
hs : (s ∘ₗ f) (s m) = LinearMap.id (s m)
⊢ m - f (s m) ∈ s.ker

Tactic:
simp only [LinearMap.coe_comp, Function.comp_apply, LinearMap.id_coe, id_eq] at hs

Goal state after:
case inr
R : Type u_1
M : Type u_2
K : Type u_3
P : Type u_4
inst✝⁶ : Ring R
inst✝⁵ : AddCommGroup M
inst✝⁴ : AddCommGroup K
inst✝³ : AddCommGroup P
inst✝² : Module R M
inst✝¹ : Module R K
inst✝ : Module R P
f : K →ₗ[R] M
g : M →ₗ[R] P
s : M →ₗ[R] K
hfg : Function.Exact ⇑f ⇑g
κ : Type u_6
σ : Type u_7
v : κ ⊕ σ → M
hg : Function.Surjective ⇑g
hslzero : ∀ (i : κ), s (v (Sum.inl i)) = 0
hli : LinearIndependent R (⇑s ∘ v ∘ Sum.inr)
hsp : ⊤ ≤ Submodule.span R (Set.range v)
m : M
this :
  ∀ {R : Type u_1} {M : Type u_2} {K : Type u_3} {P : Type u_4} [inst : Ring R] [inst_1 : AddCommGroup M]
    [inst_2 : AddCommGroup K] [inst_3 : AddCommGroup P] [inst_4 : Module R M] [inst_5 : Module R K]
    [inst_6 : Module R P] {f : K →ₗ[R] M} {g : M →ₗ[R] P} {s : M →ₗ[R] K},
    s ∘ₗ f = LinearMap.id →
      Function.Exact ⇑f ⇑g →
        ∀ {κ : Type u_6} {σ : Type u_7} (v : κ ⊕ σ → M),
          Function.Surjective ⇑g →
            (∀ (i : κ), s (v (Sum.inl i)) = 0) →
              LinearIndependent R (⇑s ∘ v ∘ Sum.inr) →
                ⊤ ≤ Submodule.span R (Set.range v) → ∀ m ∈ s.ker, g m ∈ Submodule.span R (Set.range (⇑g ∘ v ∘ Sum.inl))
h : m ∉ s.ker
x : M := f (s m)
hs : s (f (s m)) = s m
⊢ m - f (s m) ∈ s.ker
Module: Mathlib.RingTheory.Smooth.StandardSmoothCotangent

Goal state before:
pp: R : Type u_1
S : Type u_2
ι : Type u_3
σ : Type u_4
inst✝³ : CommRing R
inst✝² : CommRing S
inst✝¹ : Algebra R S
inst✝ : Finite σ
P : SubmersivePresentation R S ι σ
x : ↥P.ker
hx : ∀ (i : σ), (aeval P.val) ((pderiv (P.map i)) ↑x) = 0
this✝ : ↑x ∈ Ideal.span (Set.range P.relation)
c : σ →₀ P.Ring
hc : (c.sum fun i a ↦ a * P.relation i) = ↑x
heq : ∀ (i : σ), ∑ x ∈ c.support, (aeval P.val) (c x) * (aeval P.val) ((pderiv (P.map i)) (P.relation x)) = 0
heq2 : (∑ i ∈ c.support, (aeval P.val) (c i) • fun j ↦ (aeval P.val) ((pderiv (P.map j)) (P.relation i))) = 0
i : σ
this : LinearIndependent S fun i j ↦ (aeval P.val) ((pderiv (P.map j)) (P.relation i))
⊢ (aeval P.val) (c i) = 0

Tactic:
rw [linearIndependent_iff''] at this

Goal state after:
R : Type u_1
S : Type u_2
ι : Type u_3
σ : Type u_4
inst✝³ : CommRing R
inst✝² : CommRing S
inst✝¹ : Algebra R S
inst✝ : Finite σ
P : SubmersivePresentation R S ι σ
x : ↥P.ker
hx : ∀ (i : σ), (aeval P.val) ((pderiv (P.map i)) ↑x) = 0
this✝ : ↑x ∈ Ideal.span (Set.range P.relation)
c : σ →₀ P.Ring
hc : (c.sum fun i a ↦ a * P.relation i) = ↑x
heq : ∀ (i : σ), ∑ x ∈ c.support, (aeval P.val) (c x) * (aeval P.val) ((pderiv (P.map i)) (P.relation x)) = 0
heq2 : (∑ i ∈ c.support, (aeval P.val) (c i) • fun j ↦ (aeval P.val) ((pderiv (P.map j)) (P.relation i))) = 0
i : σ
this :
  ∀ (s : Finset σ) (g : σ → S),
    (∀ i ∉ s, g i = 0) →
      (∑ i ∈ s, g i • fun j ↦ (aeval P.val) ((pderiv (P.map j)) (P.relation i))) = 0 → ∀ (i : σ), g i = 0
⊢ (aeval P.val) (c i) = 0
Module: Mathlib.AlgebraicGeometry.EllipticCurve.Projective.Formula

Goal state before:
pp: R : Type r
inst✝ : CommRing R
W' : Projective R
P : Fin 3 → R
u : R
⊢ W'.dblY (u • P) = u ^ 4 * W'.dblY P

Tactic:
by
  simp only [dblY, negY_eq, negDblY_smul, dblX_smul, dblZ_smul]
  ring1

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

Goal state before:
pp: R S T : Type u_2
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : CommRing T
inst✝¹ : Algebra R S
inst✝ : Algebra R T
h : Algebra.IsStandardSmooth R T
r✝ : R
x✝ : T
⊢ (have I := inst✝;
    r✝ • x✝) =
    r✝ • x✝

Tactic:
simp_rw [Algebra.smul_def]

Goal state after:
R S T : Type u_2
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : CommRing T
inst✝¹ : Algebra R S
inst✝ : Algebra R T
h : Algebra.IsStandardSmooth R T
r✝ : R
x✝ : T
⊢ (algebraMap R T) r✝ * x✝ = r✝ • x✝
Module: Mathlib.RingTheory.RingHom.StandardSmooth

Goal state before:
pp: R S T : Type u_2
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : CommRing T
inst✝¹ : Algebra R S
inst✝ : Algebra R T
h : Algebra.IsStandardSmooth R T
this : Algebra.IsStandardSmooth S (S ⊗[R] T)
r✝ : S
x✝ : S ⊗[R] T
⊢ (have I := (algebraMap S (S ⊗[R] T)).toAlgebra;
    r✝ • x✝) =
    r✝ • x✝

Tactic:
simp_rw [Algebra.smul_def]

Goal state after:
R S T : Type u_2
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : CommRing T
inst✝¹ : Algebra R S
inst✝ : Algebra R T
h : Algebra.IsStandardSmooth R T
this : Algebra.IsStandardSmooth S (S ⊗[R] T)
r✝ : S
x✝ : S ⊗[R] T
⊢ r✝ • x✝ = (algebraMap S (S ⊗[R] T)) r✝ * x✝
Module: Mathlib.RingTheory.RingHom.StandardSmooth

Goal state before:
pp: n : ℕ
R S T : Type u_2
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : CommRing T
inst✝¹ : Algebra R S
inst✝ : Algebra R T
h : Algebra.IsStandardSmoothOfRelativeDimension n R T
r✝ : R
x✝ : T
⊢ (have I := inst✝;
    r✝ • x✝) =
    r✝ • x✝

Tactic:
simp_rw [Algebra.smul_def]

Goal state after:
n : ℕ
R S T : Type u_2
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : CommRing T
inst✝¹ : Algebra R S
inst✝ : Algebra R T
h : Algebra.IsStandardSmoothOfRelativeDimension n R T
r✝ : R
x✝ : T
⊢ (algebraMap R T) r✝ * x✝ = r✝ • x✝
Module: Mathlib.RingTheory.RingHom.StandardSmooth

Goal state before:
pp: n : ℕ
R S T : Type u_2
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : CommRing T
inst✝¹ : Algebra R S
inst✝ : Algebra R T
h : Algebra.IsStandardSmoothOfRelativeDimension n R T
this : Algebra.IsStandardSmoothOfRelativeDimension n S (S ⊗[R] T)
r✝ : S
x✝ : S ⊗[R] T
⊢ (have I := (algebraMap S (S ⊗[R] T)).toAlgebra;
    r✝ • x✝) =
    r✝ • x✝

Tactic:
simp_rw [Algebra.smul_def]

Goal state after:
n : ℕ
R S T : Type u_2
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : CommRing T
inst✝¹ : Algebra R S
inst✝ : Algebra R T
h : Algebra.IsStandardSmoothOfRelativeDimension n R T
this : Algebra.IsStandardSmoothOfRelativeDimension n S (S ⊗[R] T)
r✝ : S
x✝ : S ⊗[R] T
⊢ r✝ • x✝ = (algebraMap S (S ⊗[R] T)) r✝ * x✝
Module: Mathlib.RingTheory.RingHom.StandardSmooth

Goal state before:
pp: n : ℕ
R : Type u
S : Type v
inst✝³ : CommRing R
inst✝² : CommRing S
inst✝¹ : Algebra R S
inst✝ : Algebra.IsStandardSmoothOfRelativeDimension n R S
this✝¹ : (α : Type) → [_root_.Finite α] → Fintype α := Fintype.ofFinite
ι σ : Type
w✝¹ : _root_.Finite σ
w✝ : _root_.Finite ι
P : Algebra.SubmersivePresentation R S ι σ
e✝ : P.dimension = n
e₀ : σ ⊕ Fin n ≃ ι :=
  ((Equiv.ofInjective P.map ⋯).sumCongr (Finite.equivFinOfCardEq ⋯).symm).trans (Equiv.Set.sumCompl (Set.range P.map))
e : MvPolynomial σ (MvPolynomial (Fin n) R) ≃ₐ[R] P.Ring :=
  (MvPolynomial.sumAlgEquiv R σ (Fin n)).symm.trans (MvPolynomial.renameEquiv R e₀)
φ : MvPolynomial (Fin n) R →ₐ[R] P.Ring :=
  (↑e).comp (IsScalarTower.toAlgHom R (MvPolynomial (Fin n) R) (MvPolynomial σ (MvPolynomial (Fin n) R)))
algInst✝¹ : Algebra (MvPolynomial (Fin n) R) P.Ring := φ.toAlgebra
algInst✝ : Algebra (MvPolynomial (Fin n) R) S := ((algebraMap P.Ring S).comp φ.toRingHom).toAlgebra
scalarTowerInst✝ : IsScalarTower (MvPolynomial (Fin n) R) P.Ring S :=
  IsScalarTower.of_algebraMap_eq' (Eq.refl (algebraMap (MvPolynomial (Fin n) R) S))
this✝ : IsScalarTower R (MvPolynomial (Fin n) R) P.Ring
this : IsScalarTower R (MvPolynomial (Fin n) R) S
H :
  (MvPolynomial.aeval fun x ↦ (algebraMap P.Ring S) (e (MvPolynomial.X x))).toRingHom =
    (algebraMap P.Ring S).comp e.toRingEquiv.toRingHom
⊢ Ideal.span (Set.range (⇑e.symm ∘ P.relation)) =
    (Algebra.Generators.ofSurjective (fun x ↦ (algebraMap P.Ring S) (e (MvPolynomial.X x))) ⋯).ker

Tactic:
rw [Set.range_comp, ← AlgEquiv.coe_ringEquiv e.symm, AlgEquiv.symm_toRingEquiv,
        ← Ideal.map_span, P.span_range_relation_eq_ker, Ideal.map_symm]
      exact congr(RingHom.ker $H).symm

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

Goal state before:
pp: case refine_1
⊢ @Surjective ⊓ @IsLocalIso ≤ @Surjective ⊓ @Flat

Tactic:
exact inf_le_inf le_rfl (IsLocalIso.le_of_isZariskiLocalAtSource _)

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

Goal state before:
pp: case H₁
⊢ @Surjective ⊓ @IsLocalIso ≤ @Surjective ⊓ @Flat

Tactic:
exact inf_le_inf le_rfl (IsLocalIso.le_of_isZariskiLocalAtSource _)

Goal state after:
Module: Mathlib.RingTheory.Conductor

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : Algebra R S
L : Type u_3
inst✝⁴ : CommRing L
inst✝³ : Algebra S L
inst✝² : Algebra R L
inst✝¹ : IsScalarTower R S L
inst✝ : FaithfulSMul S L
x : S
y : L
⊢ y ∈ coeSubmodule L (conductor R x) ↔
    ∀ (z : S), y * (algebraMap S L) z ∈ Subalgebra.map (IsScalarTower.toAlgHom R S L) R[x]

Tactic:
simp only [coeSubmodule, Submodule.mem_map, linearMap_apply, Subalgebra.mem_map,
      IsScalarTower.coe_toAlgHom']
    constructor
    · rintro ⟨y, hy, rfl⟩ z
      exact ⟨_, hy z, map_mul _ _ _⟩
    · intro H
      obtain ⟨y, _, e⟩ := H 1
      rw [map_one, mul_one] at e
      subst e
      simp only [← map_mul, (FaithfulSMul.algebraMap_injective S L).eq_iff,
        exists_eq_right] at H
      exact ⟨_, H, rfl⟩

Goal state after:
Module: Mathlib.RingTheory.Conductor

Goal state before:
pp: case h
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
this : z ∈ ⇑(algebraMap (↥R[x]) S) '' ↑(Ideal.map (algebraMap R ↥R[x]) I) ↔ ⟨z, hz⟩ ∈ Ideal.map (algebraMap R ↥R[x]) I
a : ↥R[x]
ha : a ∈ ↑(Ideal.map (algebraMap R ↥R[x]) I) ∧ (algebraMap (↥R[x]) S) a = (algebraMap R S) p * z
⊢ a + (algebraMap R ↥R[x]) q * ⟨z, hz⟩ ∈ ↑(Ideal.map (algebraMap R ↥R[x]) I) ∧
    (algebraMap (↥R[x]) S) (a + (algebraMap R ↥R[x]) q * ⟨z, hz⟩) = (algebraMap R S) p * z + (algebraMap R S) q * z

Tactic:
refine ⟨Ideal.add_mem (I.map (algebraMap R R<x>)) ha.left ?_, by
          simp only [ha.right, map_add, map_mul, add_right_inj]; rfl⟩

Goal state after:
case h
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
this : z ∈ ⇑(algebraMap (↥R[x]) S) '' ↑(Ideal.map (algebraMap R ↥R[x]) I) ↔ ⟨z, hz⟩ ∈ Ideal.map (algebraMap R ↥R[x]) I
a : ↥R[x]
ha : a ∈ ↑(Ideal.map (algebraMap R ↥R[x]) I) ∧ (algebraMap (↥R[x]) S) a = (algebraMap R S) p * z
⊢ (algebraMap R ↥R[x]) q * ⟨z, hz⟩ ∈ Ideal.map (algebraMap R ↥R[x]) I
Module: Mathlib.FieldTheory.RatFunc.AsPolynomial

Goal state before:
pp: K : Type u
inst✝ : Field K
f : K⟮X⟯
a : K
ha : Polynomial.C a = f.num
b : K
hb : Polynomial.C b = f.denom
⊢ ∃ c, f = C c

Tactic:
use a / b

Goal state after:
case h
K : Type u
inst✝ : Field K
f : K⟮X⟯
a : K
ha : Polynomial.C a = f.num
b : K
hb : Polynomial.C b = f.denom
⊢ f = C (a / b)
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
⊢ IsAlmostIntegral R[X] (p - (monomial p.natDegree) p.leadingCoeff)

Tactic:
← mem_completeIntegralClosure,

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 - (monomial p.natDegree) p.leadingCoeff ∈ completeIntegralClosure R[X] S[X]
Module: Mathlib.RingTheory.QuasiFinite.Weakly

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 Q : Ideal S
inst✝² : P.IsPrime
inst✝¹ : Q.IsPrime
h₁ : P ≤ Q
h₂ : Ideal.under R P = Ideal.under R Q
inst✝ : WeaklyQuasiFiniteAt R Q
this : (Ideal.map (Ideal.Quotient.mk (Ideal.map (algebraMap R S) (Ideal.under R Q))) P).IsPrime
⊢ Ideal.under R (Ideal.under S (Ideal.map (Ideal.Quotient.mk (Ideal.map (algebraMap R S) (Ideal.under R Q))) P)) =
    Ideal.under R (Ideal.map (Ideal.Quotient.mk (Ideal.map (algebraMap R S) (Ideal.under R Q))) Q)

Tactic:
← Ideal.under_under (A := R) (B := S) (C := S ⧸ _)

Goal state after:
R : Type u_1
S : Type u_2
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : Algebra R S
P Q : Ideal S
inst✝² : P.IsPrime
inst✝¹ : Q.IsPrime
h₁ : P ≤ Q
h₂ : Ideal.under R P = Ideal.under R Q
inst✝ : WeaklyQuasiFiniteAt R Q
this : (Ideal.map (Ideal.Quotient.mk (Ideal.map (algebraMap R S) (Ideal.under R Q))) P).IsPrime
⊢ Ideal.under R (Ideal.under S (Ideal.map (Ideal.Quotient.mk (Ideal.map (algebraMap R S) (Ideal.under R Q))) P)) =
    Ideal.under R (Ideal.under S (Ideal.map (Ideal.Quotient.mk (Ideal.map (algebraMap R S) (Ideal.under R Q))) Q))
Module: Mathlib.RingTheory.QuasiFinite.Weakly

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : Algebra R S
p : Ideal S
inst✝⁴ : p.IsPrime
inst✝³ : QuasiFiniteAt R (Ideal.map (Ideal.Quotient.mk (Ideal.map (algebraMap R S) (Ideal.under R p))) p)
A : Type u_4
inst✝² : CommRing A
inst✝¹ : Algebra R A
q : Ideal (A ⊗[R] S)
inst✝ : q.IsPrime
hq : p = Ideal.comap TensorProduct.includeRight.toRingHom q
φ : A ⊗[R] S →ₐ[A] (A ⧸ Ideal.under A q) ⊗[R] (S ⧸ Ideal.map (algebraMap R S) (Ideal.under R p)) :=
  TensorProduct.map (Ideal.Quotient.mkₐ A (Ideal.under A q))
    (Ideal.Quotient.mkₐ R (Ideal.map (algebraMap R S) (Ideal.under R p)))
hφ₁ : Function.Surjective ⇑φ
hφ₂ : RingHom.ker φ.toRingHom = Ideal.map (algebraMap A (A ⊗[R] S)) (Ideal.under A q)
hφ₃ :
  φ.comp TensorProduct.includeRight.toRingHom =
    TensorProduct.includeRight.comp (Ideal.Quotient.mk (Ideal.map (algebraMap R S) (Ideal.under R p)))
this : (Ideal.map φ.toRingHom q).IsPrime
⊢ Function.Surjective ⇑φ.toRingHom

Tactic:
by exact hφ₁

Goal state after: