mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Algebra.Module.LocalizedModule.Basic

Goal state before:
pp: R : Type u_1
inst✝¹¹ : CommSemiring R
S : Submonoid R
M : Type u_2
M' : Type u_3
M'' : Type u_4
inst✝¹⁰ : AddCommMonoid M
inst✝⁹ : AddCommMonoid M'
inst✝⁸ : AddCommMonoid M''
A : Type u_5
inst✝⁷ : CommSemiring A
inst✝⁶ : Algebra R A
inst✝⁵ : Module A M'
inst✝⁴ : IsLocalization S A
inst✝³ : Module R M
inst✝² : Module R M'
inst✝¹ : Module R M''
inst✝ : IsScalarTower R A M'
f : M →ₗ[R] M'
g : M →ₗ[R] M''
e : M'' ≃ₗ[R] M
hf : IsLocalizedModule S f
x₁✝ x₂✝ : M''
h : f (e x₁✝) = f (e x₂✝)
c : ↥S
hc : c • e x₁✝ = c • e x₂✝
⊢ c • x₁✝ = c • x₂✝

Tactic:
by simpa only [Submonoid.smul_def, map_smul, e.symm_apply_apply]
      using congr(e.symm $hc)

Goal state after:
Module: Mathlib.Algebra.Module.LocalizedModule.Basic

Goal state before:
pp: case e_a
R : Type u_1
inst✝⁵ : CommSemiring R
S : Submonoid R
M : Type u_2
M' : Type u_3
inst✝⁴ : AddCommMonoid M
inst✝³ : AddCommMonoid M'
inst✝² : Module R M
inst✝¹ : Module R M'
f : M →ₗ[R] M'
inst✝ : IsLocalizedModule S f
x y : LocalizedModule S M
a a' : M
b b' : ↥S
⊢ f (↑(b * b') • a) = ↑b • f (b' • a)

Tactic:
simp [mul_smul, Submonoid.smul_def]

Goal state after:
Module: Mathlib.Algebra.Category.Ring.Under.Basic

Goal state before:
pp: R S : CommRingCat
inst✝ : Algebra ↑R ↑S
⊢ ∀ {X Y : Under R} (f : X ⟶ Y),
    (R.tensorProd S).map f ≫ (tensorProdObjIsoPushoutObj S Y).hom =
      (tensorProdObjIsoPushoutObj S X).hom ≫ (Under.pushout (ofHom (algebraMap ↑R ↑S))).map f

Tactic:
intro A B f

Goal state after:
R S : CommRingCat
inst✝ : Algebra ↑R ↑S
A B : Under R
f : A ⟶ B
⊢ (R.tensorProd S).map f ≫ (tensorProdObjIsoPushoutObj S B).hom =
    (tensorProdObjIsoPushoutObj S A).hom ≫ (Under.pushout (ofHom (algebraMap ↑R ↑S))).map f
Module: Mathlib.CategoryTheory.Comma.Over.Pullback

Goal state before:
pp: C : Type u
inst✝² : Category.{v, u} C
X✝ Y✝ : C
D : Type u₂
inst✝¹ : Category.{v₂, u₂} D
X Y : C
f : X ⟶ Y
inst✝ : HasPushoutsAlong f
x : Under X
y : Under Y
u : (pushout f).obj x ⟶ y
⊢ x.hom ≫ pushout.inl x.hom f ≫ Hom.right u = f ≫ ((pushout f).obj x).hom ≫ Hom.right u

Tactic:
simp only [map_obj_right, pushout_obj, mk_right, mk_hom]

Goal state after:
C : Type u
inst✝² : Category.{v, u} C
X✝ Y✝ : C
D : Type u₂
inst✝¹ : Category.{v₂, u₂} D
X Y : C
f : X ⟶ Y
inst✝ : HasPushoutsAlong f
x : Under X
y : Under Y
u : (pushout f).obj x ⟶ y
⊢ x.hom ≫ pushout.inl x.hom f ≫ Hom.right u = f ≫ pushout.inr x.hom f ≫ Hom.right u
Module: Mathlib.Algebra.Module.LocalizedModule.Basic

Goal state before:
pp: R : Type u_1
inst✝⁵ : CommSemiring R
S : Submonoid R
M : Type u_6
M' : Type u_7
inst✝⁴ : NonUnitalNonAssocSemiring M
inst✝³ : Semiring M'
inst✝² : Module R M
inst✝¹ : Algebra R M'
f : M →ₗ[R] M'
hf : ∀ (m₁ m₂ : M), f (m₁ * m₂) = f m₁ * f m₂
inst✝ : IsLocalizedModule S f
m₁ m₂ : M
s₁ s₂ : ↥S
⊢ f (m₁ • m₂) = f m₁ • f m₂

Tactic:
smul_eq_mul,

Goal state after:
R : Type u_1
inst✝⁵ : CommSemiring R
S : Submonoid R
M : Type u_6
M' : Type u_7
inst✝⁴ : NonUnitalNonAssocSemiring M
inst✝³ : Semiring M'
inst✝² : Module R M
inst✝¹ : Algebra R M'
f : M →ₗ[R] M'
hf : ∀ (m₁ m₂ : M), f (m₁ * m₂) = f m₁ * f m₂
inst✝ : IsLocalizedModule S f
m₁ m₂ : M
s₁ s₂ : ↥S
⊢ f (m₁ * m₂) = f m₁ * f m₂
Module: Mathlib.Algebra.Category.Ring.Constructions

Goal state before:
pp: A B : CommRingCat
f g : A ⟶ B
F : WalkingParallelPair ⥤ CommRingCat
⊢ IsLocalHom (Hom.hom (limit.π F zero))

Tactic:
by
  refine Limits.π_isLocalHom _ (limit.isLimit _) zero fun x hx i ↦ ?_
  rcases i with _ | _
  · exact ⟨zero, 𝟙 _, 𝟙 _, inferInstance, by simp⟩
  · refine ⟨one, 𝟙 _, left, inferInstance, ?_⟩
    simp only [CategoryTheory.Functor.map_id, hom_id, limit.cone_x, limit.cone_π, RingHom.id_apply]
    exact (limit.w_apply F left x).symm

Goal state after:
Module: Mathlib.Algebra.Category.Ring.Constructions

Goal state before:
pp: case uniq
A B C : CommRingCat
f : A ⟶ C
g : B ⟶ C
s : PullbackCone f g
m : s.pt ⟶ of ↥(((Hom.hom f).comp (RingHom.fst ↑A ↑B)).eqLocus ((Hom.hom g).comp (RingHom.snd ↑A ↑B)))
e₁ :
  m ≫
      ofHom
        ((RingHom.fst ↑A ↑B).comp
          (((Hom.hom f).comp (RingHom.fst ↑A ↑B)).eqLocus ((Hom.hom g).comp (RingHom.snd ↑A ↑B))).subtype) =
    s.fst
⊢ m ≫
        ofHom
          ((RingHom.snd ↑A ↑B).comp
            (((Hom.hom f).comp (RingHom.fst ↑A ↑B)).eqLocus ((Hom.hom g).comp (RingHom.snd ↑A ↑B))).subtype) =
      s.snd →
    m =
      ofHom
        (((Hom.hom s.fst).prod (Hom.hom s.snd)).codRestrict
          (((Hom.hom f).comp (RingHom.fst ↑A ↑B)).eqLocus ((Hom.hom g).comp (RingHom.snd ↑A ↑B))) ⋯)

Tactic:
e₂

Goal state after:
case uniq
A B C : CommRingCat
f : A ⟶ C
g : B ⟶ C
s : PullbackCone f g
m : s.pt ⟶ of ↥(((Hom.hom f).comp (RingHom.fst ↑A ↑B)).eqLocus ((Hom.hom g).comp (RingHom.snd ↑A ↑B)))
e₁ :
  m ≫
      ofHom
        ((RingHom.fst ↑A ↑B).comp
          (((Hom.hom f).comp (RingHom.fst ↑A ↑B)).eqLocus ((Hom.hom g).comp (RingHom.snd ↑A ↑B))).subtype) =
    s.fst
e₂ :
  m ≫
      ofHom
        ((RingHom.snd ↑A ↑B).comp
          (((Hom.hom f).comp (RingHom.fst ↑A ↑B)).eqLocus ((Hom.hom g).comp (RingHom.snd ↑A ↑B))).subtype) =
    s.snd
⊢ m =
    ofHom
      (((Hom.hom s.fst).prod (Hom.hom s.snd)).codRestrict
        (((Hom.hom f).comp (RingHom.fst ↑A ↑B)).eqLocus ((Hom.hom g).comp (RingHom.snd ↑A ↑B))) ⋯)
Module: Mathlib.Algebra.Module.LocalizedModule.Basic

Goal state before:
pp: R : Type u_6
S : Type u_7
S' : Type u_8
inst✝⁴ : CommSemiring R
inst✝³ : Ring S
inst✝² : Ring S'
inst✝¹ : Algebra R S
inst✝ : Algebra R S'
M : Submonoid R
f : S →ₐ[R] S'
h₁ : ∀ x ∈ M, IsUnit ((algebraMap R S') x)
h₂ : ∀ (y : S'), ∃ x, x.2 • y = f x.1
h₃ : ∀ (x : S), f x = 0 → ∃ m, m • x = 0
⊢ IsLocalizedModule M f.toLinearMap

Tactic:
by
  replace h₃ := fun x =>
    Iff.intro (h₃ x) fun ⟨⟨m, hm⟩, e⟩ =>
      (h₁ m hm).mul_left_cancel <| by
        rw [← Algebra.smul_def]
        simpa [Submonoid.smul_def] using f.congr_arg e
  constructor
  · intro x
    rw [Module.End.isUnit_iff]
    constructor
    · rintro a b (e : x • a = x • b)
      simp_rw [Submonoid.smul_def, Algebra.smul_def] at e
      exact (h₁ x x.2).mul_left_cancel e
    · intro a
      refine ⟨((h₁ x x.2).unit⁻¹ :) * a, ?_⟩
      rw [Module.algebraMap_end_apply, Algebra.smul_def, ← mul_assoc, IsUnit.mul_val_inv, one_mul]
  · exact h₂
  · intro x y
    dsimp only [AlgHom.toLinearMap_apply]
    rw [← sub_eq_zero, ← map_sub, h₃]
    simp_rw [smul_sub, sub_eq_zero]
    exact id

Goal state after:
Module: Mathlib.CategoryTheory.IsConnected

Goal state before:
pp: J : Type u₁
inst✝¹ : Category.{v₁, u₁} J
K : Type u₂
inst✝ : Category.{v₂, u₂} K
hc : IsConnected J
p : Set (ULiftHom (ULift.{u₂, u₁} J))
hj₀ : ?j₀ ∈ p
h : ∀ {j₁ j₂ : ULiftHom (ULift.{u₂, u₁} J)} (x : j₁ ⟶ j₂), j₁ ∈ p ↔ j₂ ∈ p
j : J
p' : Set J := {j | { down := j } ∈ p}
⊢ Classical.choice ⋯ ∈ {j | { down := j } ∈ p}

Tactic:
exact hj₀

Goal state after:
Module: Mathlib.CategoryTheory.IsConnected

Goal state before:
pp: case tail
J : Type u₁
inst✝ : Category.{v₁, u₁} J
α : Type u₁
F : J → α
hF : ∀ {j₁ j₂ : J} (x : j₁ ⟶ j₂), F j₁ = F j₂
j j' b✝ c✝ : J
a✝ : Relation.ReflTransGen Zag j b✝
hj : Zag b✝ c✝
ih : F j = F b✝
⊢ F j = F c✝

Tactic:
rw [ih]
    rcases hj with (⟨⟨hj⟩⟩ | ⟨⟨hj⟩⟩)
    exacts [hF hj, (hF hj).symm]

Goal state after:
Module: Mathlib.CategoryTheory.ObjectProperty.Small

Goal state before:
pp: C : Type u
inst✝² : Category.{v, u} C
D : Type u'
inst✝¹ : Category.{v', u'} D
P : ObjectProperty C
inst✝ : ObjectProperty.Small.{w, v, u} P
F : C ⥤ D
⊢ Function.Surjective fun X ↦ ⟨F.obj ↑X, ⋯⟩

Tactic:
by
    rintro ⟨_, ⟨X, hX⟩⟩
    exact ⟨⟨X, hX⟩, rfl⟩

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

Goal state before:
pp: C : Type u_1
D : Type u_2
inst✝³ : Category.{u_3, u_1} C
inst✝² : Category.{u_4, u_2} D
P : MorphismProperty D
Q : MorphismProperty C
inst✝¹ : Q.IsMultiplicative
F : C ⥤ D
X : D
inst✝ : F.Full
⊢ ∀ {X_1 Y : P.CostructuredArrow ⊤ F X}, Function.Surjective (CostructuredArrow.toOver P F X).map

Tactic:
intro A B f

Goal state after:
C : Type u_1
D : Type u_2
inst✝³ : Category.{u_3, u_1} C
inst✝² : Category.{u_4, u_2} D
P : MorphismProperty D
Q : MorphismProperty C
inst✝¹ : Q.IsMultiplicative
F : C ⥤ D
X : D
inst✝ : F.Full
A B : P.CostructuredArrow ⊤ F X
f : (CostructuredArrow.toOver P F X).obj A ⟶ (CostructuredArrow.toOver P F X).obj B
⊢ ∃ a, (CostructuredArrow.toOver P F X).map a = f
Module: Mathlib.CategoryTheory.Elements

Goal state before:
pp: C : Type u
inst✝ : Category.{v, u} C
F : C ⥤ Type w
X✝ Y✝ : StructuredArrow PUnit.{w + 1} F
f : X✝ ⟶ Y✝
⊢ (ConcreteCategory.hom (F.map (StructuredArrow.Hom.right f)))
      (F.elementsMk X✝.right ((ConcreteCategory.hom X✝.hom) PUnit.unit)).snd =
    (F.elementsMk Y✝.right ((ConcreteCategory.hom Y✝.hom) PUnit.unit)).snd

Tactic:
by simp [ConcreteCategory.congr_hom f.w.symm .unit]; rfl

Goal state after:
Module: Mathlib.CategoryTheory.Elements

Goal state before:
pp: case h_obj
C : Type u
inst✝ : Category.{v, u} C
F₁ F₂ : Cᵒᵖ ⥤ Type v
α : F₁ ⟶ F₂
⊢ ∀ (X : F₁.Elementsᵒᵖ),
    ((map α).op ⋙ toCostructuredArrow F₂).obj X = (toCostructuredArrow F₁ ⋙ CostructuredArrow.map α).obj X

pp: case h_map
C : Type u
inst✝ : Category.{v, u} C
F₁ F₂ : Cᵒᵖ ⥤ Type v
α : F₁ ⟶ F₂
⊢ autoParam
    (∀ (X Y : F₁.Elementsᵒᵖ) (f : X ⟶ Y),
      ((map α).op ⋙ toCostructuredArrow F₂).map f =
        eqToHom ⋯ ≫ (toCostructuredArrow F₁ ⋙ CostructuredArrow.map α).map f ≫ eqToHom ⋯)
    Functor.ext._auto_1

Tactic:
· intro X
    simp only [CostructuredArrow.map_mk, toCostructuredArrow_obj, Functor.op_obj,
      Functor.comp_obj]
    congr
    ext _ f
    exact (α.naturality_apply f.op (unop X).snd).symm

Goal state after:
case h_map
C : Type u
inst✝ : Category.{v, u} C
F₁ F₂ : Cᵒᵖ ⥤ Type v
α : F₁ ⟶ F₂
⊢ autoParam
    (∀ (X Y : F₁.Elementsᵒᵖ) (f : X ⟶ Y),
      ((map α).op ⋙ toCostructuredArrow F₂).map f =
        eqToHom ⋯ ≫ (toCostructuredArrow F₁ ⋙ CostructuredArrow.map α).map f ≫ eqToHom ⋯)
    Functor.ext._auto_1
Module: Mathlib.CategoryTheory.Grothendieck

Goal state before:
pp: case h_map
C : Type u
inst✝ : Category.{v, u} C
F : C ⥤ Cat
⊢ autoParam
    (∀ (X Y : Grothendieck F) (f : X ⟶ Y), (map (𝟙 F)).map f = eqToHom ⋯ ≫ (𝟭 (Grothendieck F)).map f ≫ eqToHom ⋯)
    ext._auto_1

Tactic:
· intro X Y f
    simp [map_map]
    rfl

Goal state after:
Module: Mathlib.CategoryTheory.Limits.Connected

Goal state before:
pp: case e_a
J : Type u₁
inst✝³ : Category.{v₁, u₁} J
C : Type u₂
inst✝² : Category.{v₂, u₂} C
inst✝¹ : IsConnected J
F : J ⥤ C
inst✝ : HasColimit F
c : Cocone F
hc : IsColimit c
j : J
⊢ colimit.ι ((Functor.const J).obj c.pt) j =
    ((isColimitConstCocone J c.pt).coconePointUniqueUpToIso (colimit.isColimit ((Functor.const J).obj c.pt))).hom

Tactic:
simp [← Iso.comp_inv_eq_id]

Goal state after:
Module: Mathlib.CategoryTheory.WithTerminal.Basic

Goal state before:
pp: C : Type u
inst✝ : Category.{v, u} C
J : Type u_1
x y : WidePullbackShape J
f : x ⟶ y
⊢ (fun f ↦
        match x, y, f with
        | some x, some y, f => cast ⋯ (Hom.id (some y))
        | none, some y, f => PEmpty.casesOn (fun t ↦ f = t → (none ⟶ some y)) f ⋯
        | some x, none, f => Hom.term x
        | none, none, f => Hom.id none)
      ((fun x_1 ↦
          match y, x, x_1 with
          | .(none), .(some j), Hom.term j => PUnit.unit
          | y, .(y), Hom.id .(y) => 𝟙 (widePullbackShapeEquivObj y))
        f) =
    f

Tactic:
by apply Subsingleton.allEq

Goal state after:
Module: Mathlib.CategoryTheory.EffectiveEpi.Basic

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
X Y : C
f : Y ⟶ X
inst✝ : EffectiveEpi f
Z✝ : C
m₁ m₂ : X ⟶ Z✝
h : f ≫ m₁ = f ≫ m₂
⊢ m₁ = m₂

Tactic:
show m₂ = desc f (f ≫ m₂) (fun _ _ h => by simp [← assoc, h]) from uniq _ _ _ _ rfl

Goal state after:
C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
X Y : C
f : Y ⟶ X
inst✝ : EffectiveEpi f
Z✝ : C
m₁ m₂ : X ⟶ Z✝
h : f ≫ m₁ = f ≫ m₂
⊢ m₁ = desc f (f ≫ m₂) ⋯
Module: Mathlib.RingTheory.FinitePresentation

Goal state before:
pp: R : Type w₁
A : Type w₂
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
n : ℕ
f : MvPolynomial (Fin n) R →ₐ[R] A
hf : Surjective ⇑f
inst✝ : FinitePresentation R A
m : ℕ
f' : MvPolynomial (Fin m) R →ₐ[R] A
hf' : Surjective ⇑f'
s : Finset (MvPolynomial (Fin m) R)
hs : Ideal.span ↑s = RingHom.ker f'.toRingHom
RXn : Type (max w₁ 0) := MvPolynomial (Fin n) R
RXm : Type (max w₁ 0) := MvPolynomial (Fin m) R
g : Fin n → MvPolynomial (Fin m) R
hg : ∀ (i : Fin n), f' (g i) = f (MvPolynomial.X i)
h : Fin m → MvPolynomial (Fin n) R
hh : ∀ (i : Fin m), f (h i) = f' (MvPolynomial.X i)
aeval_h : RXm →ₐ[R] RXn := MvPolynomial.aeval h
g' : Fin n → RXn := fun i ↦ MvPolynomial.X i - aeval_h (g i)
hh' : ∀ (x : RXm), f (aeval_h x) = f' x
s' : Set RXn := Set.range g' ∪ ⇑aeval_h '' ↑s
leI : Ideal.span s' ≤ RingHom.ker f.toRingHom
x : RXn
hx : x ∈ RingHom.ker f.toRingHom
⊢ x ∈ Ideal.span s'

Tactic:
have : x ∈ aeval_h.range.toAddSubmonoid ⊔ (Ideal.span s').toAddSubmonoid := by
      have : x ∈ adjoin R (Set.range X : Set RXn) := by
        rw [adjoin_range_X]
        trivial
      refine adjoin_induction ?_ ?_ ?_ ?_ this
      · rintro _ ⟨i, rfl⟩
        rw [← sub_add_cancel (X i) (aeval h (g i)), add_comm]
        apply AddSubmonoid.add_mem_sup
        · exact Set.mem_range_self _
        · apply Submodule.subset_span
          apply Set.mem_union_left
          exact Set.mem_range_self _
      · intro r
        apply AddSubmonoid.mem_sup_left
        exact ⟨C r, aeval_C _ _⟩
      · intro _ _ _ _ h₁ h₂
        exact add_mem h₁ h₂
      · intro p₁ p₂ _ _ h₁ h₂
        obtain ⟨_, ⟨x₁, rfl⟩, y₁, hy₁, rfl⟩ := AddSubmonoid.mem_sup.mp h₁
        obtain ⟨_, ⟨x₂, rfl⟩, y₂, hy₂, rfl⟩ := AddSubmonoid.mem_sup.mp h₂
        rw [mul_add, add_mul, add_assoc, ← map_mul]
        apply AddSubmonoid.add_mem_sup
        · exact Set.mem_range_self _
        · exact add_mem (Ideal.mul_mem_right _ _ hy₁) (Ideal.mul_mem_left _ _ hy₂)

Goal state after:
R : Type w₁
A : Type w₂
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
n : ℕ
f : MvPolynomial (Fin n) R →ₐ[R] A
hf : Surjective ⇑f
inst✝ : FinitePresentation R A
m : ℕ
f' : MvPolynomial (Fin m) R →ₐ[R] A
hf' : Surjective ⇑f'
s : Finset (MvPolynomial (Fin m) R)
hs : Ideal.span ↑s = RingHom.ker f'.toRingHom
RXn : Type (max w₁ 0) := MvPolynomial (Fin n) R
RXm : Type (max w₁ 0) := MvPolynomial (Fin m) R
g : Fin n → MvPolynomial (Fin m) R
hg : ∀ (i : Fin n), f' (g i) = f (MvPolynomial.X i)
h : Fin m → MvPolynomial (Fin n) R
hh : ∀ (i : Fin m), f (h i) = f' (MvPolynomial.X i)
aeval_h : RXm →ₐ[R] RXn := MvPolynomial.aeval h
g' : Fin n → RXn := fun i ↦ MvPolynomial.X i - aeval_h (g i)
hh' : ∀ (x : RXm), f (aeval_h x) = f' x
s' : Set RXn := Set.range g' ∪ ⇑aeval_h '' ↑s
leI : Ideal.span s' ≤ RingHom.ker f.toRingHom
x : RXn
hx : x ∈ RingHom.ker f.toRingHom
this : x ∈ aeval_h.range.toAddSubmonoid ⊔ (Ideal.span s').toAddSubmonoid
⊢ x ∈ Ideal.span s'
Module: Mathlib.RingTheory.FinitePresentation

Goal state before:
pp: R : Type w₁
A : Type w₂
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
n : ℕ
f : MvPolynomial (Fin n) R →ₐ[R] A
hf : Surjective ⇑f
inst✝ : FinitePresentation R A
m : ℕ
f' : MvPolynomial (Fin m) R →ₐ[R] A
hf' : Surjective ⇑f'
s : Finset (MvPolynomial (Fin m) R)
hs : Ideal.span ↑s = RingHom.ker f'.toRingHom
RXn : Type (max w₁ 0) := MvPolynomial (Fin n) R
RXm : Type (max w₁ 0) := MvPolynomial (Fin m) R
g : Fin n → MvPolynomial (Fin m) R
hg : ∀ (i : Fin n), f' (g i) = f (MvPolynomial.X i)
h : Fin m → MvPolynomial (Fin n) R
hh : ∀ (i : Fin m), f (h i) = f' (MvPolynomial.X i)
aeval_h : RXm →ₐ[R] RXn := MvPolynomial.aeval h
g' : Fin n → RXn := fun i ↦ MvPolynomial.X i - aeval_h (g i)
hh' : ∀ (x : RXm), f (aeval_h x) = f' x
s' : Set RXn := Set.range g' ∪ ⇑aeval_h '' ↑s
leI : Ideal.span s' ≤ RingHom.ker f.toRingHom
x : RXn
hx : x ∈ RingHom.ker f.toRingHom
this : x ∈ aeval_h.range.toAddSubmonoid ⊔ (Ideal.span s').toAddSubmonoid
⊢ x ∈ Ideal.span s'

Tactic:
obtain ⟨_, ⟨x, rfl⟩, y, hy, rfl⟩ := AddSubmonoid.mem_sup.mp this

Goal state after:
R : Type w₁
A : Type w₂
inst✝³ : CommRing R
inst✝² : CommRing A
inst✝¹ : Algebra R A
n : ℕ
f : MvPolynomial (Fin n) R →ₐ[R] A
hf : Surjective ⇑f
inst✝ : FinitePresentation R A
m : ℕ
f' : MvPolynomial (Fin m) R →ₐ[R] A
hf' : Surjective ⇑f'
s : Finset (MvPolynomial (Fin m) R)
hs : Ideal.span ↑s = RingHom.ker f'.toRingHom
RXn : Type (max w₁ 0) := MvPolynomial (Fin n) R
RXm : Type (max w₁ 0) := MvPolynomial (Fin m) R
g : Fin n → MvPolynomial (Fin m) R
hg : ∀ (i : Fin n), f' (g i) = f (MvPolynomial.X i)
h : Fin m → MvPolynomial (Fin n) R
hh : ∀ (i : Fin m), f (h i) = f' (MvPolynomial.X i)
aeval_h : RXm →ₐ[R] RXn := MvPolynomial.aeval h
g' : Fin n → RXn := fun i ↦ MvPolynomial.X i - aeval_h (g i)
hh' : ∀ (x : RXm), f (aeval_h x) = f' x
s' : Set RXn := Set.range g' ∪ ⇑aeval_h '' ↑s
leI : Ideal.span s' ≤ RingHom.ker f.toRingHom
x : RXm
y : RXn
hy : y ∈ (Ideal.span s').toAddSubmonoid
hx : aeval_h.toRingHom x + y ∈ RingHom.ker f.toRingHom
this : aeval_h.toRingHom x + y ∈ aeval_h.range.toAddSubmonoid ⊔ (Ideal.span s').toAddSubmonoid
⊢ aeval_h.toRingHom x + y ∈ Ideal.span s'
Module: Mathlib.RingTheory.FinitePresentation

Goal state before:
pp: case zero
P : (R : Type u) → [inst : CommRing R] → (S : Type u) → [inst_1 : CommRing S] → (R →+* S) → Prop
Q : (R : Type u) → [inst : CommRing R] → (S : Type v) → [inst_1 : CommRing S] → (R →+* S) → Prop
polynomial : ∀ (R : Type u) [inst : CommRing R], P R R[X] C
fg_ker :
  ∀ (R : Type u) [inst : CommRing R] (S : Type v) [inst_1 : CommRing S] (f : R →+* S),
    Surjective ⇑f → (ker f).FG → Q R S f
comp :
  ∀ (R : Type u) [inst : CommRing R] (S : Type u) [inst_1 : CommRing S] (T : Type v) [inst_2 : CommRing T] (f : R →+* S)
    (g : S →+* T), P R S f → Q S T g → Q R T (g.comp f)
R : Type u
S : Type v
inst✝¹ : CommRing R
inst✝ : CommRing S
g' : MvPolynomial (Fin 0) R →+* S
hg : Surjective ⇑g'
hg' : (ker g').FG
this : Algebra R S := (g'.comp MvPolynomial.C).toAlgebra
⊢ Q R S (g'.comp MvPolynomial.C)

Tactic:
refine fg_ker _ _ _ (hg.comp (MvPolynomial.C_surjective (Fin 0))) ?_
    rw [← comap_ker]
    convert! hg'.map (MvPolynomial.isEmptyRingEquiv R (Fin 0)).toRingHom using 1
    simp only [RingEquiv.toRingHom_eq_coe, ← MvPolynomial.isEmptyRingEquiv_symm_toRingHom]
    exact Ideal.comap_symm (MvPolynomial.isEmptyRingEquiv R (Fin 0))

Goal state after:
Module: Mathlib.CategoryTheory.Limits.Shapes.Pullback.Assoc

Goal state before:
pp: C : Type u
inst✝⁴ : Category.{v, u} C
X₁ X₂ X₃ Y₁ Y₂ : C
f₁ : X₁ ⟶ Y₁
f₂ : X₂ ⟶ Y₁
f₃ : X₂ ⟶ Y₂
f₄ : X₃ ⟶ Y₂
inst✝³ : HasPullback f₁ f₂
inst✝² : HasPullback f₃ f₄
inst✝¹ : HasPullback (pullback.snd f₁ f₂ ≫ f₃) f₄
inst✝ : HasPullback f₁ (pullback.fst f₃ f₄ ≫ f₂)
⊢ (pullbackAssoc f₁ f₂ f₃ f₄).inv ≫ pullback.fst (pullback.snd f₁ f₂ ≫ f₃) f₄ ≫ pullback.fst f₁ f₂ =
    pullback.lift (pullback.fst f₁ (pullback.fst f₃ f₄ ≫ f₂))
        (pullback.snd f₁ (pullback.fst f₃ f₄ ≫ f₂) ≫ pullback.fst f₃ f₄) ⋯ ≫
      pullback.fst f₁ f₂

pp: C : Type u
inst✝⁴ : Category.{v, u} C
X₁ X₂ X₃ Y₁ Y₂ : C
f₁ : X₁ ⟶ Y₁
f₂ : X₂ ⟶ Y₁
f₃ : X₂ ⟶ Y₂
f₄ : X₃ ⟶ Y₂
inst✝³ : HasPullback f₁ f₂
inst✝² : HasPullback f₃ f₄
inst✝¹ : HasPullback (pullback.snd f₁ f₂ ≫ f₃) f₄
inst✝ : HasPullback f₁ (pullback.fst f₃ f₄ ≫ f₂)
⊢ pullback.lift (pullback.fst f₁ (pullback.fst f₃ f₄ ≫ f₂))
        (pullback.snd f₁ (pullback.fst f₃ f₄ ≫ f₂) ≫ pullback.fst f₃ f₄) ⋯ ≫
      pullback.fst f₁ f₂ =
    pullback.fst f₁ (pullback.fst f₃ f₄ ≫ f₂)

Tactic:
· rw [← Category.assoc]
    congr 1
    exact IsLimit.conePointUniqueUpToIso_inv_comp _ _ WalkingCospan.left

Goal state after:
C : Type u
inst✝⁴ : Category.{v, u} C
X₁ X₂ X₃ Y₁ Y₂ : C
f₁ : X₁ ⟶ Y₁
f₂ : X₂ ⟶ Y₁
f₃ : X₂ ⟶ Y₂
f₄ : X₃ ⟶ Y₂
inst✝³ : HasPullback f₁ f₂
inst✝² : HasPullback f₃ f₄
inst✝¹ : HasPullback (pullback.snd f₁ f₂ ≫ f₃) f₄
inst✝ : HasPullback f₁ (pullback.fst f₃ f₄ ≫ f₂)
⊢ pullback.lift (pullback.fst f₁ (pullback.fst f₃ f₄ ≫ f₂))
        (pullback.snd f₁ (pullback.fst f₃ f₄ ≫ f₂) ≫ pullback.fst f₃ f₄) ⋯ ≫
      pullback.fst f₁ f₂ =
    pullback.fst f₁ (pullback.fst f₃ f₄ ≫ f₂)
Module: Mathlib.RingTheory.RingHomProperties

Goal state before:
pp: P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : RespectsIso P
R S T : CommRingCat
f : R ⟶ S
g : S ⟶ T
inst✝ : IsIso g
H : P ((CommRingCat.Hom.hom g).comp (CommRingCat.Hom.hom f))
⊢ P (CommRingCat.Hom.hom f)

Tactic:
convert! hP.1 (f ≫ g).hom (asIso g).symm.commRingCatIsoToRingEquiv H

Goal state after:
P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hP : RespectsIso P
R S T : CommRingCat
f : R ⟶ S
g : S ⟶ T
inst✝ : IsIso g
H : P ((CommRingCat.Hom.hom g).comp (CommRingCat.Hom.hom f))
⊢ CommRingCat.Hom.hom f = (asIso g).symm.commRingCatIsoToRingEquiv.toRingHom.comp (CommRingCat.Hom.hom (f ≫ g))
Module: Mathlib.RingTheory.RingHomProperties

Goal state before:
pp: P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
h₁ : RespectsIso P
h₂ :
  ∀ ⦃R S T : Type u⦄ [inst : CommRing R] [inst_1 : CommRing S] [inst_2 : CommRing T] [inst_3 : Algebra R S]
    [inst_4 : Algebra R T], P (algebraMap R T) → P (algebraMap S (S ⊗[R] T))
R S R' S' : Type u
inst✝¹⁰ : CommRing R
inst✝⁹ : CommRing S
inst✝⁸ : CommRing R'
inst✝⁷ : CommRing S'
inst✝⁶ : Algebra R S
inst✝⁵ : Algebra R R'
inst✝⁴ : Algebra R S'
inst✝³ : Algebra S S'
inst✝² : Algebra R' S'
inst✝¹ : IsScalarTower R S S'
inst✝ : IsScalarTower R R' S'
h : Algebra.IsPushout R S R' S'
H : P (algebraMap R S)
e : R' ⊗[R] S ≃ₛₗ[id R'] S' := ⋯.equiv
⊢ P (algebraMap R' S')

Tactic:
let f' := Algebra.TensorProduct.productMap (IsScalarTower.toAlgHom R R' S')
    (IsScalarTower.toAlgHom R S S')

Goal state after:
P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
h₁ : RespectsIso P
h₂ :
  ∀ ⦃R S T : Type u⦄ [inst : CommRing R] [inst_1 : CommRing S] [inst_2 : CommRing T] [inst_3 : Algebra R S]
    [inst_4 : Algebra R T], P (algebraMap R T) → P (algebraMap S (S ⊗[R] T))
R S R' S' : Type u
inst✝¹⁰ : CommRing R
inst✝⁹ : CommRing S
inst✝⁸ : CommRing R'
inst✝⁷ : CommRing S'
inst✝⁶ : Algebra R S
inst✝⁵ : Algebra R R'
inst✝⁴ : Algebra R S'
inst✝³ : Algebra S S'
inst✝² : Algebra R' S'
inst✝¹ : IsScalarTower R S S'
inst✝ : IsScalarTower R R' S'
h : Algebra.IsPushout R S R' S'
H : P (algebraMap R S)
e : R' ⊗[R] S ≃ₛₗ[id R'] S' := ⋯.equiv
f' : R' ⊗[R] S →ₐ[R] S' :=
  Algebra.TensorProduct.productMap (IsScalarTower.toAlgHom R R' S') (IsScalarTower.toAlgHom R S S')
⊢ P (algebraMap R' S')
Module: Mathlib.RingTheory.RingHomProperties

Goal state before:
pp: P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
h₁ : RespectsIso P
h₂ :
  ∀ ⦃R S T : Type u⦄ [inst : CommRing R] [inst_1 : CommRing S] [inst_2 : CommRing T] [inst_3 : Algebra R S]
    [inst_4 : Algebra R T], P (algebraMap R T) → P (algebraMap S (S ⊗[R] T))
R S R' S' : Type u
inst✝¹⁰ : CommRing R
inst✝⁹ : CommRing S
inst✝⁸ : CommRing R'
inst✝⁷ : CommRing S'
inst✝⁶ : Algebra R S
inst✝⁵ : Algebra R R'
inst✝⁴ : Algebra R S'
inst✝³ : Algebra S S'
inst✝² : Algebra R' S'
inst✝¹ : IsScalarTower R S S'
inst✝ : IsScalarTower R R' S'
h : Algebra.IsPushout R S R' S'
H : P (algebraMap R S)
e : R' ⊗[R] S ≃ₛₗ[id R'] S' := ⋯.equiv
f' : R' ⊗[R] S →ₐ[R] S' :=
  Algebra.TensorProduct.productMap (IsScalarTower.toAlgHom R R' S') (IsScalarTower.toAlgHom R S S')
hef : ∀ (x : R' ⊗[R] S), e x = f' x
x y : R' ⊗[R] S
⊢ e (x * y) = e x * e y

Tactic:
simp_rw [hef, map_mul]

Goal state after:
Module: Mathlib.RingTheory.RingHomProperties

Goal state before:
pp: P : {R S : Type u} → [inst : CommRing R] → [inst_1 : CommRing S] → (R →+* S) → Prop
hQ : RespectsIso fun {R S} [CommRing R] [CommRing S] ↦ P
A B A' B' : CommRingCat
f : A ⟶ B
g : A' ⟶ B'
e : Arrow.mk f ≅ Arrow.mk g
⊢ P (CommRingCat.Hom.hom f) ↔ P (CommRingCat.Hom.hom g)

Tactic:
by
  have : (toMorphismProperty P).RespectsIso := by
    rwa [← toMorphismProperty_respectsIso_iff]
  change toMorphismProperty P _ ↔ toMorphismProperty P _
  rw [MorphismProperty.arrow_mk_iso_iff (toMorphismProperty P) e]

Goal state after: