mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.CategoryTheory.Functor.KanExtension.Basic

Goal state before:
pp: C : Type u_1
C' : Type u_2
H : Type u_3
D : Type u_4
inst✝⁴ : Category.{v_1, u_1} C
inst✝³ : Category.{v_2, u_2} C'
inst✝² : Category.{v_3, u_3} H
inst✝¹ : Category.{v_4, u_4} D
L : C ⥤ D
F : C ⥤ H
F' : D ⥤ H
G : C' ⥤ C
inst✝ : G.IsEquivalence
α : F ⟶ L ⋙ F'
eq : StructuredArrow.IsUniversal (LeftExtension.mk F' α) ≃
  StructuredArrow.IsUniversal (LeftExtension.mk F' (G.whiskerLeft α ≫ (G.associator L F').inv)) :=
  (LeftExtension.isUniversalPrecompEquiv L F G (LeftExtension.mk F' α)).trans
    (IsInitial.equivOfIso
      (StructuredArrow.isoMk
        (Iso.refl (StructuredArrow.right ((LeftExtension.precomp L F G).obj (LeftExtension.mk F' α)))) ⋯))
⊢ F'.IsLeftKanExtension α ↔ F'.IsLeftKanExtension (G.whiskerLeft α ≫ (G.associator L F').inv)

Tactic:
constructor

Goal state after:
case mp
C : Type u_1
C' : Type u_2
H : Type u_3
D : Type u_4
inst✝⁴ : Category.{v_1, u_1} C
inst✝³ : Category.{v_2, u_2} C'
inst✝² : Category.{v_3, u_3} H
inst✝¹ : Category.{v_4, u_4} D
L : C ⥤ D
F : C ⥤ H
F' : D ⥤ H
G : C' ⥤ C
inst✝ : G.IsEquivalence
α : F ⟶ L ⋙ F'
eq : StructuredArrow.IsUniversal (LeftExtension.mk F' α) ≃
  StructuredArrow.IsUniversal (LeftExtension.mk F' (G.whiskerLeft α ≫ (G.associator L F').inv)) := ⋯
⊢ F'.IsLeftKanExtension α → F'.IsLeftKanExtension (G.whiskerLeft α ≫ (G.associator L F').inv)

case mpr
C : Type u_1
C' : Type u_2
H : Type u_3
D : Type u_4
inst✝⁴ : Category.{v_1, u_1} C
inst✝³ : Category.{v_2, u_2} C'
inst✝² : Category.{v_3, u_3} H
inst✝¹ : Category.{v_4, u_4} D
L : C ⥤ D
F : C ⥤ H
F' : D ⥤ H
G : C' ⥤ C
inst✝ : G.IsEquivalence
α : F ⟶ L ⋙ F'
eq : StructuredArrow.IsUniversal (LeftExtension.mk F' α) ≃
  StructuredArrow.IsUniversal (LeftExtension.mk F' (G.whiskerLeft α ≫ (G.associator L F').inv)) := ⋯
⊢ F'.IsLeftKanExtension (G.whiskerLeft α ≫ (G.associator L F').inv) → F'.IsLeftKanExtension α
Module: Mathlib.CategoryTheory.Functor.KanExtension.Pointwise

Goal state before:
pp: C : Type u_1
D : Type u_2
H : Type u_4
inst✝³ : Category.{v_1, u_1} C
inst✝² : Category.{v_2, u_2} D
inst✝¹ : Category.{v_4, u_4} H
L : C ⥤ D
F : C ⥤ H
inst✝ : L.HasPointwiseRightKanExtension F
G : D ⥤ H
α : L ⋙ G ⟶ F
Y : D
⊢ ((L.pointwiseRightKanExtension F).liftOfIsRightKanExtension (L.pointwiseRightKanExtensionCounit F) G α).app Y =
    limit.lift (StructuredArrow.proj Y L ⋙ F) (L.structuredArrowMapCone F G α Y)

Tactic:
by
  let β : G ⟶ L.pointwiseRightKanExtension F :=
    { app := fun Y ↦ limit.lift _ (structuredArrowMapCone L F G α Y) }
  have h : (pointwiseRightKanExtension L F).liftOfIsRightKanExtension
      (pointwiseRightKanExtensionCounit L F) G α = β := by
    apply hom_ext_of_isRightKanExtension (α := pointwiseRightKanExtensionCounit L F)
    aesop
  exact NatTrans.congr_app h Y

Goal state after:
Module: Mathlib.CategoryTheory.Functor.KanExtension.Basic

Goal state before:
pp: C : Type u_1
C' : Type u_2
H : Type u_3
D : Type u_4
inst✝⁴ : Category.{v_1, u_1} C
inst✝³ : Category.{v_2, u_2} C'
inst✝² : Category.{v_3, u_3} H
inst✝¹ : Category.{v_4, u_4} D
L : C ⥤ D
F : C ⥤ H
F' : D ⥤ H
G : C' ⥤ C
inst✝ : G.IsEquivalence
α : L ⋙ F' ⟶ F
eq : CostructuredArrow.IsUniversal (RightExtension.mk F' α) ≃
  CostructuredArrow.IsUniversal (RightExtension.mk F' ((G.associator L F').hom ≫ G.whiskerLeft α)) :=
  (RightExtension.isUniversalPrecompEquiv L F G (RightExtension.mk F' α)).trans
    (IsTerminal.equivOfIso
      (CostructuredArrow.isoMk
        (Iso.refl (CostructuredArrow.left ((RightExtension.precomp L F G).obj (RightExtension.mk F' α)))) ⋯))
⊢ F'.IsRightKanExtension α ↔ F'.IsRightKanExtension ((G.associator L F').hom ≫ G.whiskerLeft α)

Tactic:
constructor

Goal state after:
case mp
C : Type u_1
C' : Type u_2
H : Type u_3
D : Type u_4
inst✝⁴ : Category.{v_1, u_1} C
inst✝³ : Category.{v_2, u_2} C'
inst✝² : Category.{v_3, u_3} H
inst✝¹ : Category.{v_4, u_4} D
L : C ⥤ D
F : C ⥤ H
F' : D ⥤ H
G : C' ⥤ C
inst✝ : G.IsEquivalence
α : L ⋙ F' ⟶ F
eq : CostructuredArrow.IsUniversal (RightExtension.mk F' α) ≃
  CostructuredArrow.IsUniversal (RightExtension.mk F' ((G.associator L F').hom ≫ G.whiskerLeft α)) := ⋯
⊢ F'.IsRightKanExtension α → F'.IsRightKanExtension ((G.associator L F').hom ≫ G.whiskerLeft α)

case mpr
C : Type u_1
C' : Type u_2
H : Type u_3
D : Type u_4
inst✝⁴ : Category.{v_1, u_1} C
inst✝³ : Category.{v_2, u_2} C'
inst✝² : Category.{v_3, u_3} H
inst✝¹ : Category.{v_4, u_4} D
L : C ⥤ D
F : C ⥤ H
F' : D ⥤ H
G : C' ⥤ C
inst✝ : G.IsEquivalence
α : L ⋙ F' ⟶ F
eq : CostructuredArrow.IsUniversal (RightExtension.mk F' α) ≃
  CostructuredArrow.IsUniversal (RightExtension.mk F' ((G.associator L F').hom ≫ G.whiskerLeft α)) := ⋯
⊢ F'.IsRightKanExtension ((G.associator L F').hom ≫ G.whiskerLeft α) → F'.IsRightKanExtension α
Module: Mathlib.CategoryTheory.Limits.Preserves.FunctorCategory

Goal state before:
pp: C : Type u
inst✝⁵ : Category.{v₁, u} C
D : Type u₂
inst✝⁴ : Category.{u, u₂} D
inst✝³ : HasBinaryProducts D
inst✝² : HasColimits D
inst✝¹ : ∀ (X : D), PreservesColimits (prod.functor.obj X)
F : C ⥤ D
J : Type u
inst✝ : Category.{u, u} J
K : J ⥤ C ⥤ D
c : Cocone K
t : IsColimit c
⊢ IsColimit ((prod.functor.obj F).mapCocone c)

Tactic:
by
            apply evaluationJointlyReflectsColimits _ fun {k} => ?_
            change IsColimit ((prod.functor.obj F ⋙ (evaluation _ _).obj k).mapCocone c)
            let :=
              isColimitOfPreserves ((evaluation C D).obj k ⋙ prod.functor.obj (F.obj k)) t
            apply IsColimit.mapCoconeEquiv _ this
            apply (NatIso.ofComponents _ _).symm
            · intro G
              apply asIso (prodComparison ((evaluation C D).obj k) F G)
            · intro G G'
              apply prodComparison_natural ((evaluation C D).obj k) (𝟙 F)

Goal state after:
Module: Mathlib.CategoryTheory.Functor.KanExtension.Basic

Goal state before:
pp: C : Type u_1
H : Type u_3
D : Type u_4
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Category.{v_3, u_3} H
inst✝ : Category.{v_4, u_4} D
L : C ⥤ D
F₁ F₂ : C ⥤ H
F₁' F₂' : D ⥤ H
α₁ : F₁ ⟶ L ⋙ F₁'
α₂ : F₂ ⟶ L ⋙ F₂'
e : F₁ ≅ F₂
e' : F₁' ≅ F₂'
h : α₁ ≫ L.whiskerLeft e'.hom = e.hom ≫ α₂
eq : StructuredArrow.IsUniversal (LeftExtension.mk F₁' α₁) ≃ StructuredArrow.IsUniversal (LeftExtension.mk F₂' α₂) :=
  (LeftExtension.mk F₁' α₁).isUniversalEquivOfIso₂ (LeftExtension.mk F₂' α₂) e e' h
⊢ F₁'.IsLeftKanExtension α₁ ↔ F₂'.IsLeftKanExtension α₂

Tactic:
constructor

Goal state after:
case mp
C : Type u_1
H : Type u_3
D : Type u_4
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Category.{v_3, u_3} H
inst✝ : Category.{v_4, u_4} D
L : C ⥤ D
F₁ F₂ : C ⥤ H
F₁' F₂' : D ⥤ H
α₁ : F₁ ⟶ L ⋙ F₁'
α₂ : F₂ ⟶ L ⋙ F₂'
e : F₁ ≅ F₂
e' : F₁' ≅ F₂'
h : α₁ ≫ L.whiskerLeft e'.hom = e.hom ≫ α₂
eq : StructuredArrow.IsUniversal (LeftExtension.mk F₁' α₁) ≃ StructuredArrow.IsUniversal (LeftExtension.mk F₂' α₂) := ⋯
⊢ F₁'.IsLeftKanExtension α₁ → F₂'.IsLeftKanExtension α₂

case mpr
C : Type u_1
H : Type u_3
D : Type u_4
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Category.{v_3, u_3} H
inst✝ : Category.{v_4, u_4} D
L : C ⥤ D
F₁ F₂ : C ⥤ H
F₁' F₂' : D ⥤ H
α₁ : F₁ ⟶ L ⋙ F₁'
α₂ : F₂ ⟶ L ⋙ F₂'
e : F₁ ≅ F₂
e' : F₁' ≅ F₂'
h : α₁ ≫ L.whiskerLeft e'.hom = e.hom ≫ α₂
eq : StructuredArrow.IsUniversal (LeftExtension.mk F₁' α₁) ≃ StructuredArrow.IsUniversal (LeftExtension.mk F₂' α₂) := ⋯
⊢ F₂'.IsLeftKanExtension α₂ → F₁'.IsLeftKanExtension α₁
Module: Mathlib.CategoryTheory.Functor.KanExtension.Basic

Goal state before:
pp: C : Type u_1
H : Type u_3
D : Type u_4
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Category.{v_3, u_3} H
inst✝ : Category.{v_4, u_4} D
L : C ⥤ D
F₁ F₂ : C ⥤ H
F₁' F₂' : D ⥤ H
α₁ : L ⋙ F₁' ⟶ F₁
α₂ : L ⋙ F₂' ⟶ F₂
e : F₁ ≅ F₂
e' : F₁' ≅ F₂'
h : L.whiskerLeft e'.hom ≫ α₂ = α₁ ≫ e.hom
eq : CostructuredArrow.IsUniversal (RightExtension.mk F₁' α₁) ≃
  CostructuredArrow.IsUniversal (RightExtension.mk F₂' α₂) :=
  (RightExtension.mk F₁' α₁).isUniversalEquivOfIso₂ (RightExtension.mk F₂' α₂) e e' h
⊢ F₁'.IsRightKanExtension α₁ ↔ F₂'.IsRightKanExtension α₂

Tactic:
constructor

Goal state after:
case mp
C : Type u_1
H : Type u_3
D : Type u_4
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Category.{v_3, u_3} H
inst✝ : Category.{v_4, u_4} D
L : C ⥤ D
F₁ F₂ : C ⥤ H
F₁' F₂' : D ⥤ H
α₁ : L ⋙ F₁' ⟶ F₁
α₂ : L ⋙ F₂' ⟶ F₂
e : F₁ ≅ F₂
e' : F₁' ≅ F₂'
h : L.whiskerLeft e'.hom ≫ α₂ = α₁ ≫ e.hom
eq : CostructuredArrow.IsUniversal (RightExtension.mk F₁' α₁) ≃
  CostructuredArrow.IsUniversal (RightExtension.mk F₂' α₂) := ⋯
⊢ F₁'.IsRightKanExtension α₁ → F₂'.IsRightKanExtension α₂

case mpr
C : Type u_1
H : Type u_3
D : Type u_4
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Category.{v_3, u_3} H
inst✝ : Category.{v_4, u_4} D
L : C ⥤ D
F₁ F₂ : C ⥤ H
F₁' F₂' : D ⥤ H
α₁ : L ⋙ F₁' ⟶ F₁
α₂ : L ⋙ F₂' ⟶ F₂
e : F₁ ≅ F₂
e' : F₁' ≅ F₂'
h : L.whiskerLeft e'.hom ≫ α₂ = α₁ ≫ e.hom
eq : CostructuredArrow.IsUniversal (RightExtension.mk F₁' α₁) ≃
  CostructuredArrow.IsUniversal (RightExtension.mk F₂' α₂) := ⋯
⊢ F₂'.IsRightKanExtension α₂ → F₁'.IsRightKanExtension α₁
Module: Mathlib.CategoryTheory.Functor.KanExtension.Basic

Goal state before:
pp: case refine_1
C : Type u_1
H : Type u_3
D : Type u_4
D' : Type u_5
inst✝⁴ : Category.{v_1, u_1} C
inst✝³ : Category.{v_3, u_3} H
inst✝² : Category.{v_4, u_4} D
inst✝¹ : Category.{v_5, u_5} D'
L : C ⥤ D
L' : D ⥤ D'
F₀ : C ⥤ H
F₁ : D ⥤ H
α : F₀ ⟶ L ⋙ F₁
inst✝ : F₁.IsLeftKanExtension α
F₂ : D' ⥤ H
L'' : C ⥤ D'
e : L ⋙ L' ≅ L''
β : F₁ ⟶ L' ⋙ F₂
γ : F₀ ⟶ L'' ⋙ F₂
hγ : α ≫ L.whiskerLeft β ≫ (L.associator L' F₂).inv ≫ whiskerRight e.hom F₂ = γ
Ψ : (L ⋙ L').LeftExtension F₀ ≌ L''.LeftExtension F₀ := leftExtensionEquivalenceOfIso₁ e F₀
hα : StructuredArrow.IsUniversal (LeftExtension.mk F₁ α)
x✝ : F₂.IsLeftKanExtension β
h : StructuredArrow.IsUniversal (LeftExtension.mk F₂ β)
this : StructuredArrow.IsUniversal ((LeftExtension.precomp₂ L' α).obj (LeftExtension.mk F₂ β))
i : (LeftExtension.precomp₂ L' α).obj (LeftExtension.mk F₂ β) ≅ Ψ.inverse.obj (LeftExtension.mk F₂ γ) :=
  StructuredArrow.isoMk
    (NatIso.ofComponents
      (fun x ↦ Iso.refl ((StructuredArrow.right ((LeftExtension.precomp₂ L' α).obj (LeftExtension.mk F₂ β))).obj x)) ⋯)
    ⋯
⊢ IsInitial (Ψ.inverse.obj (LeftExtension.mk F₂ γ))

Tactic:
exact IsInitial.ofIso this i

Goal state after:
Module: Mathlib.CategoryTheory.Abelian.GrothendieckAxioms.Basic

Goal state before:
pp: C : Type u
inst✝¹¹ : Category.{v, u} C
D : Type u_1
J : Type u_2
inst✝¹⁰ : Category.{v_1, u_2} J
inst✝⁹ : Category.{v_2, u_1} D
inst✝⁸ : HasColimitsOfShape J C
inst✝⁷ : HasColimitsOfShape J D
inst✝⁶ : HasExactColimitsOfShape J D
F : C ⥤ D
inst✝⁵ : PreservesFiniteLimits F
inst✝⁴ : ReflectsFiniteLimits F
inst✝³ : HasFiniteLimits C
inst✝² : PreservesColimitsOfShape J F
I : Type
inst✝¹ : SmallCategory I
inst✝ : FinCategory I
G : I ⥤ J ⥤ C
c : Cone G
hc : IsLimit c
⊢ Nonempty (IsLimit (colim.mapCone c))

Tactic:
constructor

Goal state after:
C : Type u
inst✝¹¹ : Category.{v, u} C
D : Type u_1
J : Type u_2
inst✝¹⁰ : Category.{v_1, u_2} J
inst✝⁹ : Category.{v_2, u_1} D
inst✝⁸ : HasColimitsOfShape J C
inst✝⁷ : HasColimitsOfShape J D
inst✝⁶ : HasExactColimitsOfShape J D
F : C ⥤ D
inst✝⁵ : PreservesFiniteLimits F
inst✝⁴ : ReflectsFiniteLimits F
inst✝³ : HasFiniteLimits C
inst✝² : PreservesColimitsOfShape J F
I : Type
inst✝¹ : SmallCategory I
inst✝ : FinCategory I
G : I ⥤ J ⥤ C
c : Cone G
hc : IsLimit c
⊢ IsLimit (colim.mapCone c)
Module: Mathlib.CategoryTheory.Abelian.GrothendieckAxioms.Basic

Goal state before:
pp: C : Type u
inst✝¹¹ : Category.{v, u} C
D : Type u_1
J : Type u_2
inst✝¹⁰ : Category.{v_1, u_1} D
inst✝⁹ : Category.{v_2, u_2} J
inst✝⁸ : HasLimitsOfShape J C
inst✝⁷ : HasLimitsOfShape J D
inst✝⁶ : HasExactLimitsOfShape J D
F : C ⥤ D
inst✝⁵ : PreservesFiniteColimits F
inst✝⁴ : ReflectsFiniteColimits F
inst✝³ : HasFiniteColimits C
inst✝² : PreservesLimitsOfShape J F
I : Type
inst✝¹ : SmallCategory I
inst✝ : FinCategory I
G : I ⥤ J ⥤ C
c : Cocone G
hc : IsColimit c
⊢ Nonempty (IsColimit (lim.mapCocone c))

Tactic:
constructor

Goal state after:
C : Type u
inst✝¹¹ : Category.{v, u} C
D : Type u_1
J : Type u_2
inst✝¹⁰ : Category.{v_1, u_1} D
inst✝⁹ : Category.{v_2, u_2} J
inst✝⁸ : HasLimitsOfShape J C
inst✝⁷ : HasLimitsOfShape J D
inst✝⁶ : HasExactLimitsOfShape J D
F : C ⥤ D
inst✝⁵ : PreservesFiniteColimits F
inst✝⁴ : ReflectsFiniteColimits F
inst✝³ : HasFiniteColimits C
inst✝² : PreservesLimitsOfShape J F
I : Type
inst✝¹ : SmallCategory I
inst✝ : FinCategory I
G : I ⥤ J ⥤ C
c : Cocone G
hc : IsColimit c
⊢ IsColimit (lim.mapCocone c)
Module: Mathlib.CategoryTheory.Limits.Presheaf

Goal state before:
pp: C : Type u₁
inst✝¹ : Category.{v₁, u₁} C
ℰ : Type u₂
inst✝ : Category.{v₂, u₂} ℰ
A : C ⥤ ℰ
P : Cᵒᵖ ⥤ Type (max w v₁ v₂)
E : ℰ
f :
  CostructuredArrow.proj uliftYoneda.{max w v₂, v₁, u₁} P ⋙ A ⟶
    (Functor.const (CostructuredArrow uliftYoneda.{max w v₂, v₁, u₁} P)).obj E
x✝¹ x✝ : Cᵒᵖ
g : x✝¹ ⟶ x✝
x : P.obj x✝¹
⊢ uliftYoneda.{max w v₂, v₁, u₁}.map g.unop ≫ uliftYonedaEquiv.symm x = uliftYonedaEquiv.symm ((hom (P.map g)) x)

Tactic:
rw [uliftYonedaEquiv_symm_map]

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

Goal state before:
pp: C : Type u₁
inst✝¹ : Category.{v₁, u₁} C
ℰ : Type u₂
inst✝ : Category.{v₂, u₂} ℰ
A : C ⥤ ℰ
P : Cᵒᵖ ⥤ Type (max w v₁ v₂)
E : ℰ
f :
  CostructuredArrow.proj uliftYoneda.{max w v₂, v₁, u₁} P ⋙ A ⟶
    (Functor.const (CostructuredArrow uliftYoneda.{max w v₂, v₁, u₁} P)).obj E
x✝¹ x✝ : Cᵒᵖ
g : x✝¹ ⟶ x✝
x : P.obj x✝¹
⊢ uliftYoneda.{max w v₂, v₁, u₁}.map g.unop ≫ (CostructuredArrow.mk (uliftYonedaEquiv.symm x)).hom =
    (CostructuredArrow.mk (uliftYonedaEquiv.symm ((hom (P.map g)) x))).hom

Tactic:
dsimp
              rw [uliftYonedaEquiv_symm_map]

Goal state after:
Module: Mathlib.CategoryTheory.Abelian.GrothendieckAxioms.Basic

Goal state before:
pp: C : Type u
inst✝⁴ : Category.{v, u} C
inst✝³ : HasFilteredColimitsOfSize.{w₂, w₂', v, u} C
inst✝² : UnivLE.{w, w₂}
inst✝¹ : UnivLE.{w', w₂'}
inst✝ : AB5OfSize.{w₂, w₂', v, u} C
this : HasFilteredColimitsOfSize.{w, w', v, u} C
⊢ AB5OfSize.{w, w', v, u} C

Tactic:
constructor

Goal state after:
C : Type u
inst✝⁴ : Category.{v, u} C
inst✝³ : HasFilteredColimitsOfSize.{w₂, w₂', v, u} C
inst✝² : UnivLE.{w, w₂}
inst✝¹ : UnivLE.{w', w₂'}
inst✝ : AB5OfSize.{w₂, w₂', v, u} C
this : HasFilteredColimitsOfSize.{w, w', v, u} C
⊢ ∀ (J : Type w') [inst : Category.{w, w'} J] [inst_1 : IsFiltered J], HasExactColimitsOfShape J C
Module: Mathlib.CategoryTheory.Abelian.GrothendieckAxioms.Basic

Goal state before:
pp: C : Type u
inst✝⁴ : Category.{v, u} C
inst✝³ : HasCofilteredLimitsOfSize.{w₂, w₂', v, u} C
inst✝² : UnivLE.{w, w₂}
inst✝¹ : UnivLE.{w', w₂'}
inst✝ : AB5StarOfSize.{w₂, w₂', v, u} C
this : HasCofilteredLimitsOfSize.{w, w', v, u} C
⊢ AB5StarOfSize.{w, w', v, u} C

Tactic:
constructor

Goal state after:
C : Type u
inst✝⁴ : Category.{v, u} C
inst✝³ : HasCofilteredLimitsOfSize.{w₂, w₂', v, u} C
inst✝² : UnivLE.{w, w₂}
inst✝¹ : UnivLE.{w', w₂'}
inst✝ : AB5StarOfSize.{w₂, w₂', v, u} C
this : HasCofilteredLimitsOfSize.{w, w', v, u} C
⊢ ∀ (J : Type w') [inst : Category.{w, w'} J] [inst_1 : IsCofiltered J], HasExactLimitsOfShape J C
Module: Mathlib.CategoryTheory.Comma.StructuredArrow.Small

Goal state before:
pp: C : Type u₁
inst✝³ : Category.{v₁, u₁} C
D : Type u₂
inst✝² : Category.{v₂, u₂} D
S : D
T : C ⥤ D
inst✝¹ : Small.{w, u₁} C
inst✝ : LocallySmall.{w, v₂, u₂} D
f : StructuredArrow S T
⊢ ∃ a, (fun f ↦ mk f.snd) a = f

Tactic:
obtain ⟨X, f, rfl⟩ := f.mk_surjective
      exact ⟨⟨X, f⟩, rfl⟩

Goal state after:
Module: Mathlib.CategoryTheory.Comma.StructuredArrow.Small

Goal state before:
pp: C : Type u₁
inst✝³ : Category.{v₁, u₁} C
D : Type u₂
inst✝² : Category.{v₂, u₂} D
S : C ⥤ D
T : D
inst✝¹ : Small.{w, u₁} C
inst✝ : LocallySmall.{w, v₂, u₂} D
f : CostructuredArrow S T
⊢ ∃ a, (fun f ↦ mk f.snd) a = f

Tactic:
obtain ⟨X, f, rfl⟩ := f.mk_surjective
      exact ⟨⟨X, f⟩, rfl⟩

Goal state after:
Module: Mathlib.CategoryTheory.Functor.KanExtension.Basic

Goal state before:
pp: C : Type u_1
C' : Type u_2
H : Type u_3
D : Type u_4
D' : Type u_5
inst✝⁴ : Category.{v_1, u_1} C
inst✝³ : Category.{v_2, u_2} C'
inst✝² : Category.{v_3, u_3} H
inst✝¹ : Category.{v_4, u_4} D
inst✝ : Category.{v_5, u_5} D'
L : C ≌ D
F₀ : C ⥤ H
F₁ : D ⥤ H
α : F₀ ≅ L.functor ⋙ F₁
⊢ StructuredArrow.IsUniversal
    ((LeftExtension.postcomp₁ L.functor L.functor.leftUnitor.inv F₀).obj (LeftExtension.mk F₁ α.hom))

Tactic:
refine IsInitial.ofUniqueHom
    (fun y ↦ StructuredArrow.homMk <| α.inv ≫ y.hom ≫ y.right.leftUnitor.hom) ?_

Goal state after:
C : Type u_1
C' : Type u_2
H : Type u_3
D : Type u_4
D' : Type u_5
inst✝⁴ : Category.{v_1, u_1} C
inst✝³ : Category.{v_2, u_2} C'
inst✝² : Category.{v_3, u_3} H
inst✝¹ : Category.{v_4, u_4} D
inst✝ : Category.{v_5, u_5} D'
L : C ≌ D
F₀ : C ⥤ H
F₁ : D ⥤ H
α : F₀ ≅ L.functor ⋙ F₁
⊢ ∀ (Y : StructuredArrow F₀ ((whiskeringLeft C C H).obj (𝟭 C)))
    (m : (LeftExtension.postcomp₁ L.functor L.functor.leftUnitor.inv F₀).obj (LeftExtension.mk F₁ α.hom) ⟶ Y),
    m = StructuredArrow.homMk (α.inv ≫ Y.hom ≫ Y.right.leftUnitor.hom) ⋯
Module: Mathlib.CategoryTheory.Abelian.Transfer

Goal state before:
pp: C : Type u₁
inst✝⁶ : Category.{v₁, u₁} C
inst✝⁵ : Preadditive C
inst✝⁴ : HasFiniteProducts C
D : Type u₂
inst✝³ : Category.{v₂, u₂} D
inst✝² : Abelian D
F : C ⥤ D
G : D ⥤ C
inst✝¹ : G.PreservesZeroMorphisms
inst✝ : PreservesFiniteLimits G
i : F ⋙ G ≅ 𝟭 C
adj : G ⊣ F
⊢ Abelian C

Tactic:
by
  haveI := hasKernels F G i
  haveI := hasCokernels F G i adj
  have : ∀ {X Y : C} (f : X ⟶ Y), IsIso (Abelian.coimageImageComparison f) := by
    intro X Y f
    let arrowIso : Arrow.mk (G.map (F.map f)) ≅ Arrow.mk f :=
      ((Functor.mapArrowFunctor _ _).mapIso i).app (Arrow.mk f)
    have : PreservesColimits G := adj.leftAdjoint_preservesColimits
    let iso : Arrow.mk (G.map (Abelian.coimageImageComparison (F.map f))) ≅
        Arrow.mk (Abelian.coimageImageComparison f) :=
      Abelian.PreservesCoimageImageComparison.iso G (F.map f) ≪≫
        Abelian.coimageImageComparisonFunctor.mapIso arrowIso
    rw [Arrow.isIso_iff_isIso_of_isIso iso.inv]
    infer_instance
  apply Abelian.ofCoimageImageComparisonIsIso

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

Goal state before:
pp: C : Type u₁
inst✝² : Category.{v₁, u₁} C
ℰ : Type u₂
inst✝¹ : Category.{v₂, u₂} ℰ
A : C ⥤ ℰ
inst✝ : uliftYoneda.{max w v₂, v₁, u₁}.HasPointwiseLeftKanExtension A
L : (Cᵒᵖ ⥤ Type (max w v₁ v₂)) ⥤ ℰ
α : A ⟶ uliftYoneda.{max w v₂, v₁, u₁} ⋙ L
⊢ L.IsLeftKanExtension α ↔
    IsIso α ∧
      PreservesColimitsOfSize.{v₁, max w u₁ v₁ v₂, max (max (max u₁ v₁) v₂) w, v₂,
          max (max (max u₁ (v₁ + 1)) (v₂ + 1)) (w + 1), u₂}
        L

Tactic:
constructor

Goal state after:
case mp
C : Type u₁
inst✝² : Category.{v₁, u₁} C
ℰ : Type u₂
inst✝¹ : Category.{v₂, u₂} ℰ
A : C ⥤ ℰ
inst✝ : uliftYoneda.{max w v₂, v₁, u₁}.HasPointwiseLeftKanExtension A
L : (Cᵒᵖ ⥤ Type (max w v₁ v₂)) ⥤ ℰ
α : A ⟶ uliftYoneda.{max w v₂, v₁, u₁} ⋙ L
⊢ L.IsLeftKanExtension α →
    IsIso α ∧
      PreservesColimitsOfSize.{v₁, max w u₁ v₁ v₂, max (max (max u₁ v₁) v₂) w, v₂,
          max (max (max u₁ (v₁ + 1)) (v₂ + 1)) (w + 1), u₂}
        L

case mpr
C : Type u₁
inst✝² : Category.{v₁, u₁} C
ℰ : Type u₂
inst✝¹ : Category.{v₂, u₂} ℰ
A : C ⥤ ℰ
inst✝ : uliftYoneda.{max w v₂, v₁, u₁}.HasPointwiseLeftKanExtension A
L : (Cᵒᵖ ⥤ Type (max w v₁ v₂)) ⥤ ℰ
α : A ⟶ uliftYoneda.{max w v₂, v₁, u₁} ⋙ L
⊢ IsIso α ∧
      PreservesColimitsOfSize.{v₁, max w u₁ v₁ v₂, max (max (max u₁ v₁) v₂) w, v₂,
          max (max (max u₁ (v₁ + 1)) (v₂ + 1)) (w + 1), u₂}
        L →
    L.IsLeftKanExtension α
Module: Mathlib.CategoryTheory.Generator.Basic

Goal state before:
pp: C : Type u₁
inst✝¹ : Category.{v₁, u₁} C
P : ObjectProperty C
hP : P.IsDetecting
X Y : C
f : X ⟶ Y
inst✝ : Mono f
⊢ IsIso f ↔ ∀ (G : C), P G → Function.Surjective ⇑(ConcreteCategory.hom ((coyoneda.obj (op G)).map f))

Tactic:
constructor

Goal state after:
case mp
C : Type u₁
inst✝¹ : Category.{v₁, u₁} C
P : ObjectProperty C
hP : P.IsDetecting
X Y : C
f : X ⟶ Y
inst✝ : Mono f
⊢ IsIso f → ∀ (G : C), P G → Function.Surjective ⇑(ConcreteCategory.hom ((coyoneda.obj (op G)).map f))

case mpr
C : Type u₁
inst✝¹ : Category.{v₁, u₁} C
P : ObjectProperty C
hP : P.IsDetecting
X Y : C
f : X ⟶ Y
inst✝ : Mono f
⊢ (∀ (G : C), P G → Function.Surjective ⇑(ConcreteCategory.hom ((coyoneda.obj (op G)).map f))) → IsIso f
Module: Mathlib.CategoryTheory.Generator.Basic

Goal state before:
pp: C : Type u₁
inst✝¹ : Category.{v₁, u₁} C
P : ObjectProperty C
hP : P.IsCodetecting
X Y : C
f : X ⟶ Y
inst✝ : Epi f
⊢ IsIso f ↔ ∀ (G : C), P G → Function.Surjective ⇑(ConcreteCategory.hom ((yoneda.obj G).map f.op))

Tactic:
constructor

Goal state after:
case mp
C : Type u₁
inst✝¹ : Category.{v₁, u₁} C
P : ObjectProperty C
hP : P.IsCodetecting
X Y : C
f : X ⟶ Y
inst✝ : Epi f
⊢ IsIso f → ∀ (G : C), P G → Function.Surjective ⇑(ConcreteCategory.hom ((yoneda.obj G).map f.op))

case mpr
C : Type u₁
inst✝¹ : Category.{v₁, u₁} C
P : ObjectProperty C
hP : P.IsCodetecting
X Y : C
f : X ⟶ Y
inst✝ : Epi f
⊢ (∀ (G : C), P G → Function.Surjective ⇑(ConcreteCategory.hom ((yoneda.obj G).map f.op))) → IsIso f
Module: Mathlib.CategoryTheory.Subobject.Comma

Goal state before:
pp: case refine_2
C : Type u₁
inst✝³ : Category.{v₁, u₁} C
D : Type u₂
inst✝² : Category.{v₂, u₂} D
S : C ⥤ D
T : D
inst✝¹ : HasFiniteColimits C
inst✝ : PreservesFiniteColimits S
A : CostructuredArrow S T
P Q : (CostructuredArrow S T)ᵒᵖ
f : P ⟶ op A
g : Q ⟶ op A
hf : Mono f
hg : Mono g
h :
  { toFun := fun P ↦ ⟨projectQuotient P, ⋯⟩, invFun := fun P ↦ liftQuotient ↑P ⋯, left_inv := ⋯, right_inv := ⋯ }
      (Subobject.mk f) ≤
    { toFun := fun P ↦ ⟨projectQuotient P, ⋯⟩, invFun := fun P ↦ liftQuotient ↑P ⋯, left_inv := ⋯, right_inv := ⋯ }
      (Subobject.mk g)
⊢ ((homMk (Subobject.ofMkLEMk (MonoOver.mk f).arrow.unop.left.op (MonoOver.mk g).arrow.unop.left.op h).unop ⋯).op ≫
        g).unop =
    f.unop

Tactic:
ext

Goal state after:
case refine_2
C : Type u₁
inst✝³ : Category.{v₁, u₁} C
D : Type u₂
inst✝² : Category.{v₂, u₂} D
S : C ⥤ D
T : D
inst✝¹ : HasFiniteColimits C
inst✝ : PreservesFiniteColimits S
A : CostructuredArrow S T
P Q : (CostructuredArrow S T)ᵒᵖ
f : P ⟶ op A
g : Q ⟶ op A
hf : Mono f
hg : Mono g
h :
  { toFun := fun P ↦ ⟨projectQuotient P, ⋯⟩, invFun := fun P ↦ liftQuotient ↑P ⋯, left_inv := ⋯, right_inv := ⋯ }
      (Subobject.mk f) ≤
    { toFun := fun P ↦ ⟨projectQuotient P, ⋯⟩, invFun := fun P ↦ liftQuotient ↑P ⋯, left_inv := ⋯, right_inv := ⋯ }
      (Subobject.mk g)
⊢ ((homMk (Subobject.ofMkLEMk (MonoOver.mk f).arrow.unop.left.op (MonoOver.mk g).arrow.unop.left.op h).unop ⋯).op ≫
          g).unop.left =
    f.unop.left
Module: Mathlib.CategoryTheory.Generator.Basic

Goal state before:
pp: C : Type u₁
inst✝⁴ : Category.{v₁, u₁} C
inst✝³ : LocallySmall.{w, v₁, u₁} C
inst✝² : WellPowered.{w, v₁, u₁} C
inst✝¹ : HasLimitsOfSize.{w, w, v₁, u₁} C
P : ObjectProperty C
inst✝ : ObjectProperty.Small.{w, v₁, u₁} P
hP : P.IsCoseparating
this✝³ : HasFiniteLimits C
this✝² : HasProductsOfShape (Subtype P) C
this✝¹ : ∀ (A : C), HasProductsOfShape (StructuredArrow A P.ι) C
this✝ : CompleteLattice (Subobject (∏ᶜ Subtype.val)) :=
  completeLatticeOfCompleteSemilatticeInf (Subobject (∏ᶜ Subtype.val))
this : ∀ (X : C) [inst : HasProduct (P.productToFamily X)], Mono (P.productTo X)
A : C
f g : Subobject.underlying.obj ⊥ ⟶ A
⊢ ⊥.ofLEMk (equalizer.ι f g ≫ ⊥.arrow) ⋯ ≫ equalizer.ι f g = 𝟙 (Subobject.underlying.obj ⊥)

Tactic:
ext

Goal state after:
C : Type u₁
inst✝⁴ : Category.{v₁, u₁} C
inst✝³ : LocallySmall.{w, v₁, u₁} C
inst✝² : WellPowered.{w, v₁, u₁} C
inst✝¹ : HasLimitsOfSize.{w, w, v₁, u₁} C
P : ObjectProperty C
inst✝ : ObjectProperty.Small.{w, v₁, u₁} P
hP : P.IsCoseparating
this✝³ : HasFiniteLimits C
this✝² : HasProductsOfShape (Subtype P) C
this✝¹ : ∀ (A : C), HasProductsOfShape (StructuredArrow A P.ι) C
this✝ : CompleteLattice (Subobject (∏ᶜ Subtype.val)) :=
  completeLatticeOfCompleteSemilatticeInf (Subobject (∏ᶜ Subtype.val))
this : ∀ (X : C) [inst : HasProduct (P.productToFamily X)], Mono (P.productTo X)
A : C
f g : Subobject.underlying.obj ⊥ ⟶ A
b✝ : Subtype P
⊢ ((⊥.ofLEMk (equalizer.ι f g ≫ ⊥.arrow) ⋯ ≫ equalizer.ι f g) ≫ ⊥.arrow) ≫ Pi.π Subtype.val b✝ =
    (𝟙 (Subobject.underlying.obj ⊥) ≫ ⊥.arrow) ≫ Pi.π Subtype.val b✝