mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.CategoryTheory.Sites.Sieves

Goal state before:
pp: C : Type u₁
inst✝ : Category.{v₁, u₁} C
X : C
ι : Type u_1
Y : ι → C
f : (i : ι) → Y i ⟶ X
Z : C
g : Z ⟶ X
i : ι
h : Z = Y i
hg : g = eqToHom h ≫ f i
⊢ ofArrows Y f g

Tactic:
subst h
  simp only [eqToHom_refl, id_comp] at hg
  subst hg
  constructor

Goal state after:
Module: Mathlib.CategoryTheory.Sites.Sieves

Goal state before:
pp: C : Type u₁
inst✝ : Category.{v₁, u₁} C
I : Type u_1
X : C
Y✝ : I → C
f : (i : I) → Y✝ i ⟶ X
W Y : C
i : I
h : W ⟶ Y✝ i
⊢ ∃ i_1 h_1, h ≫ f i = h_1 ≫ f i_1

Tactic:
exact ⟨i, h, rfl⟩

Goal state after:
Module: Mathlib.CategoryTheory.Sites.ConcreteSheafification

Goal state before:
pp: C : Type u
inst✝³ : Category.{v, u} C
J : GrothendieckTopology C
D : Type w
inst✝² : Category.{w', w} D
FD : D → D → Type u_1
CD : D → Type t
inst✝¹ : (X Y : D) → FunLike (FD X Y) (CD X) (CD Y)
inst✝ : ConcreteCategory D FD
X : C
P : Cᵒᵖ ⥤ D
S : J.Cover X
x : ToType (P.obj (op X))
I : S.Relation
⊢ (ConcreteCategory.hom (P.map I.r.g₁.op)) ((fun I ↦ (ConcreteCategory.hom (P.map I.f.op)) x) I.fst) =
    (ConcreteCategory.hom (P.map I.r.g₂.op)) ((fun I ↦ (ConcreteCategory.hom (P.map I.f.op)) x) I.snd)

Tactic:
simp only [← ConcreteCategory.comp_apply, ← P.map_comp, ← op_comp, I.r.w]

Goal state after:
Module: Mathlib.CategoryTheory.Sites.Subsheaf

Goal state before:
pp: case e'_3
C : Type u
inst✝ : Category.{v, u} C
J : GrothendieckTopology C
F : Cᵒᵖ ⥤ Type w
G G' : Subfunctor F
h : G ≤ G'
hF : Presieve.IsSheaf J F
hG' : Presieve.IsSheaf J G'.toFunctor
U : Cᵒᵖ
x : F.obj U
hx : x ∈ (sheafify J G).obj U
V : C
i : V ⟶ unop U
hi : (G.sieveOfSection x).arrows i
this :
  ↑((ConcreteCategory.hom ((homOfLe ⋯ ≫ G.sheafifyLift (homOfLe h) hG').app (op V)))
        ⟨(ConcreteCategory.hom (F.map i.op)) x, hi⟩) =
    ↑((ConcreteCategory.hom ((homOfLe h).app (op V))) ⟨(ConcreteCategory.hom (F.map i.op)) x, hi⟩)
⊢ (ConcreteCategory.hom (F.map i.op)) ↑((ConcreteCategory.hom ((G.sheafifyLift (homOfLe h) hG').app U)) ⟨x, hx⟩) =
    ↑((ConcreteCategory.hom ((homOfLe ⋯ ≫ G.sheafifyLift (homOfLe h) hG').app (op V)))
        ⟨(ConcreteCategory.hom (F.map i.op)) x, hi⟩)

Tactic:
rw [← Subfunctor.nat_trans_naturality]

Goal state after:
case e'_3
C : Type u
inst✝ : Category.{v, u} C
J : GrothendieckTopology C
F : Cᵒᵖ ⥤ Type w
G G' : Subfunctor F
h : G ≤ G'
hF : Presieve.IsSheaf J F
hG' : Presieve.IsSheaf J G'.toFunctor
U : Cᵒᵖ
x : F.obj U
hx : x ∈ (sheafify J G).obj U
V : C
i : V ⟶ unop U
hi : (G.sieveOfSection x).arrows i
this :
  ↑((ConcreteCategory.hom ((homOfLe ⋯ ≫ G.sheafifyLift (homOfLe h) hG').app (op V)))
        ⟨(ConcreteCategory.hom (F.map i.op)) x, hi⟩) =
    ↑((ConcreteCategory.hom ((homOfLe h).app (op V))) ⟨(ConcreteCategory.hom (F.map i.op)) x, hi⟩)
⊢ ↑((ConcreteCategory.hom ((G.sheafifyLift (homOfLe h) hG').app (op V)))
        ((ConcreteCategory.hom ((sheafify J G).toFunctor.map i.op)) ⟨x, hx⟩)) =
    ↑((ConcreteCategory.hom ((homOfLe ⋯ ≫ G.sheafifyLift (homOfLe h) hG').app (op V)))
        ⟨(ConcreteCategory.hom (F.map i.op)) x, hi⟩)
Module: Mathlib.CategoryTheory.Sites.CompatibleSheafification

Goal state before:
pp: C : Type u
inst✝⁸ : Category.{v, u} C
J : GrothendieckTopology C
D : Type u_1
inst✝⁷ : Category.{v_1, u_1} D
E : Type u_2
inst✝⁶ : Category.{v_2, u_2} E
F : D ⥤ E
inst✝⁵ : ∀ (J : MulticospanShape), HasLimitsOfShape (WalkingMulticospan J) D
inst✝⁴ : ∀ (J : MulticospanShape), HasLimitsOfShape (WalkingMulticospan J) E
inst✝³ : ∀ (X : C), HasColimitsOfShape (J.Cover X)ᵒᵖ D
inst✝² : ∀ (X : C), HasColimitsOfShape (J.Cover X)ᵒᵖ E
inst✝¹ : ∀ (X : C), PreservesColimitsOfShape (J.Cover X)ᵒᵖ F
inst✝ : ∀ (X : C) (W : J.Cover X) (P : Cᵒᵖ ⥤ D), PreservesLimit (W.index P).multicospan F
P : Cᵒᵖ ⥤ D
⊢ whiskerRight (J.toPlus P) F ≫
      (J.plusCompIso F P).hom ≫ J.plusMap (whiskerRight (J.toPlus P) F) ≫ J.plusMap (J.plusCompIso F P).hom =
    J.toPlus (P ⋙ F) ≫ J.plusMap (J.toPlus (P ⋙ F))

Tactic:
← J.plusMap_comp,

Goal state after:
C : Type u
inst✝⁸ : Category.{v, u} C
J : GrothendieckTopology C
D : Type u_1
inst✝⁷ : Category.{v_1, u_1} D
E : Type u_2
inst✝⁶ : Category.{v_2, u_2} E
F : D ⥤ E
inst✝⁵ : ∀ (J : MulticospanShape), HasLimitsOfShape (WalkingMulticospan J) D
inst✝⁴ : ∀ (J : MulticospanShape), HasLimitsOfShape (WalkingMulticospan J) E
inst✝³ : ∀ (X : C), HasColimitsOfShape (J.Cover X)ᵒᵖ D
inst✝² : ∀ (X : C), HasColimitsOfShape (J.Cover X)ᵒᵖ E
inst✝¹ : ∀ (X : C), PreservesColimitsOfShape (J.Cover X)ᵒᵖ F
inst✝ : ∀ (X : C) (W : J.Cover X) (P : Cᵒᵖ ⥤ D), PreservesLimit (W.index P).multicospan F
P : Cᵒᵖ ⥤ D
⊢ whiskerRight (J.toPlus P) F ≫
      (J.plusCompIso F P).hom ≫ J.plusMap (whiskerRight (J.toPlus P) F ≫ (J.plusCompIso F P).hom) =
    J.toPlus (P ⋙ F) ≫ J.plusMap (J.toPlus (P ⋙ F))
Module: Mathlib.CategoryTheory.Sites.Sheafification

Goal state before:
pp: C : Type u₁
inst✝² : Category.{v₁, u₁} C
J : GrothendieckTopology C
D : Type u_1
inst✝¹ : Category.{v_1, u_1} D
inst✝ : HasWeakSheafify J D
P : Cᵒᵖ ⥤ D
hP : Presheaf.IsSheaf J P
⊢ sheafifyLift J (𝟙 P) hP ≫ toSheafify J P = 𝟙 (sheafify J P)

Tactic:
by
  rw [← cancel_mono ((sheafificationAdjunction J D).counit.app ⟨P, hP⟩).hom]
  cat_disch

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

Goal state before:
pp: J : Type v'
inst✝² : Category.{u', v'} J
C : Type u
inst✝¹ : Category.{v, u} C
K : Type u_3
inst✝ : Category.{v_3, u_3} K
e : J ≌ K
F : K ⥤ C
c : Cocone F
hc : IsUniversalColimit c
⊢ IsUniversalColimit (Cocone.whisker e.functor c)

Tactic:
by
  intro F' c' α f e' hα H
  convert!
    hc (c'.whisker e.inverse) (whiskerLeft e.inverse α ≫ (e.invFunIdAssoc F).hom) f ?_
      ((hα.whiskerLeft _).comp (.of_isIso _)) ?_ using 1
  · exact (IsColimit.whiskerEquivalenceEquiv e.symm).nonempty_congr
  · convert! congr_arg (whiskerLeft e.inverse) e'
    ext
    simp
  · intro k
    rw [← Category.comp_id f]
    refine (H (e.inverse.obj k)).paste_vert ?_
    exact IsPullback.of_vert_isIso ⟨by simp⟩

Goal state after:
Module: Mathlib.CategoryTheory.Limits.Shapes.DisjointCoproduct

Goal state before:
pp: case h_2
C : Type u
inst✝² : Category.{v, u} C
X Y : C
c : BinaryCofan X Y
hc : IsColimit c
inst✝¹ : Mono c.inl
inst✝ : Mono c.inr
s : PullbackCone c.inl c.inr
hs : IsLimit s
H : IsInitial s.pt
this : ∀ (i : WalkingPair), Mono (Cofan.inj c i)
i✝ j✝ : WalkingPair
hij✝¹ : i✝ ≠ j✝
hij✝ : WalkingPair.right ≠ WalkingPair.left
⊢ IsLimit s.flip

Tactic:
exact PullbackCone.flipIsLimit hs

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

Goal state before:
pp: case e'_2.mpr
J : Type v'
inst✝² : Category.{u', v'} J
C : Type u
inst✝¹ : Category.{v, u} C
K : Type u_3
inst✝ : Category.{v_3, u_3} K
e : J ≌ K
F : K ⥤ C
c : Cocone F
hc : IsVanKampenColimit c
F' : J ⥤ C
c' : Cocone F'
α : F' ⟶ e.functor ⋙ F
f : c'.pt ⟶ (Cocone.whisker e.functor c).pt
e' : α ≫ (Cocone.whisker e.functor c).ι = c'.ι ≫ (const J).map f
hα : NatTrans.Equifibered α
H : ∀ (j : K), IsPullback (c'.ι.app (e.inverse.obj j)) (α.app (e.inverse.obj j) ≫ F.map (e.counit.app j)) f (c.ι.app j)
j : J
this : α.app j = F'.map (e.unit.app j) ≫ α.app ((e.functor ⋙ e.inverse).obj j) ≫ F.map (e.counit.app (e.functor.obj j))
⊢ IsPullback (c'.ι.app j) (α.app j) f (c.ι.app (e.functor.obj j))

Tactic:
← Category.id_comp f,

Goal state after:
case e'_2.mpr
J : Type v'
inst✝² : Category.{u', v'} J
C : Type u
inst✝¹ : Category.{v, u} C
K : Type u_3
inst✝ : Category.{v_3, u_3} K
e : J ≌ K
F : K ⥤ C
c : Cocone F
hc : IsVanKampenColimit c
F' : J ⥤ C
c' : Cocone F'
α : F' ⟶ e.functor ⋙ F
f : c'.pt ⟶ (Cocone.whisker e.functor c).pt
e' : α ≫ (Cocone.whisker e.functor c).ι = c'.ι ≫ (const J).map f
hα : NatTrans.Equifibered α
H : ∀ (j : K), IsPullback (c'.ι.app (e.inverse.obj j)) (α.app (e.inverse.obj j) ≫ F.map (e.counit.app j)) f (c.ι.app j)
j : J
this : α.app j = F'.map (e.unit.app j) ≫ α.app ((e.functor ⋙ e.inverse).obj j) ≫ F.map (e.counit.app (e.functor.obj j))
⊢ IsPullback (c'.ι.app j) (α.app j) (𝟙 c'.pt ≫ f) (c.ι.app (e.functor.obj j))
Module: Mathlib.CategoryTheory.Limits.FilteredColimitCommutesFiniteLimit

Goal state before:
pp: J : Type u₁
K : Type u₂
inst✝⁴ : SmallCategory J
inst✝³ : Category.{v₂, u₂} K
inst✝² : Small.{v, u₂} K
inst✝¹ : FinCategory J
F : J × K ⥤ Type v
inst✝ : IsFiltered K
x : limit (curry.obj F ⋙ colim)
k : J → K
y : (j : J) → F.obj (j, k j)
e :
  ∀ (j : J),
    (ConcreteCategory.hom (colimit.ι ((curry.obj F).obj j) (k j))) (y j) =
      (ConcreteCategory.hom (limit.π (curry.obj F ⋙ colim) j)) x
k' : K
g : (j : J) → k j ⟶ k'
kf : {j j' : J} → (j ⟶ j') → K
gf hf : {j j' : J} → (f : j ⟶ j') → k' ⟶ kf f
wf :
  ∀ {j j' : J} (f : j ⟶ j'),
    (ConcreteCategory.hom (F.map (𝟙 j' ×ₘ g j' ≫ gf f))) (y j') = (ConcreteCategory.hom (F.map (f ×ₘ g j ≫ hf f))) (y j)
O : Finset K := (Finset.univ.biUnion fun j ↦ Finset.univ.biUnion fun j' ↦ Finset.image kf Finset.univ) ∪ {k'}
kfO : ∀ {j j' : J} (f : j ⟶ j'), kf f ∈ O
k'O : k' ∈ O
H : Finset ((X : K) ×' (Y : K) ×' (_ : X ∈ O) ×' (_ : Y ∈ O) ×' (X ⟶ Y)) :=
  Finset.univ.biUnion fun j ↦
    Finset.univ.biUnion fun j' ↦
      Finset.univ.biUnion fun f ↦ {⟨k', ⟨kf f, ⟨k'O, ⟨⋯, gf f⟩⟩⟩⟩, ⟨k', ⟨kf f, ⟨k'O, ⟨⋯, hf f⟩⟩⟩⟩}
k'' : K
i' : {X : K} → X ∈ O → (X ⟶ k'')
s' : ∀ {X Y : K} (mX : X ∈ O) (mY : Y ∈ O) {f : X ⟶ Y}, ⟨X, ⟨Y, ⟨mX, ⟨mY, f⟩⟩⟩⟩ ∈ H → f ≫ i' mY = i' mX
i : {j j' : J} → (f : j ⟶ j') → kf f ⟶ k'' := fun {j j'} f ↦ i' ⋯
⊢ ∀ {j₁ j₂ j₃ j₄ : J} (f : j₁ ⟶ j₂) (f' : j₃ ⟶ j₄), gf f ≫ i f = hf f' ≫ i f'

Tactic:
intro j₁ j₂ j₃ j₄ f f'

Goal state after:
J : Type u₁
K : Type u₂
inst✝⁴ : SmallCategory J
inst✝³ : Category.{v₂, u₂} K
inst✝² : Small.{v, u₂} K
inst✝¹ : FinCategory J
F : J × K ⥤ Type v
inst✝ : IsFiltered K
x : limit (curry.obj F ⋙ colim)
k : J → K
y : (j : J) → F.obj (j, k j)
e :
  ∀ (j : J),
    (ConcreteCategory.hom (colimit.ι ((curry.obj F).obj j) (k j))) (y j) =
      (ConcreteCategory.hom (limit.π (curry.obj F ⋙ colim) j)) x
k' : K
g : (j : J) → k j ⟶ k'
kf : {j j' : J} → (j ⟶ j') → K
gf hf : {j j' : J} → (f : j ⟶ j') → k' ⟶ kf f
wf :
  ∀ {j j' : J} (f : j ⟶ j'),
    (ConcreteCategory.hom (F.map (𝟙 j' ×ₘ g j' ≫ gf f))) (y j') = (ConcreteCategory.hom (F.map (f ×ₘ g j ≫ hf f))) (y j)
O : Finset K := (Finset.univ.biUnion fun j ↦ Finset.univ.biUnion fun j' ↦ Finset.image kf Finset.univ) ∪ {k'}
kfO : ∀ {j j' : J} (f : j ⟶ j'), kf f ∈ O
k'O : k' ∈ O
H : Finset ((X : K) ×' (Y : K) ×' (_ : X ∈ O) ×' (_ : Y ∈ O) ×' (X ⟶ Y)) :=
  Finset.univ.biUnion fun j ↦
    Finset.univ.biUnion fun j' ↦
      Finset.univ.biUnion fun f ↦ {⟨k', ⟨kf f, ⟨k'O, ⟨⋯, gf f⟩⟩⟩⟩, ⟨k', ⟨kf f, ⟨k'O, ⟨⋯, hf f⟩⟩⟩⟩}
k'' : K
i' : {X : K} → X ∈ O → (X ⟶ k'')
s' : ∀ {X Y : K} (mX : X ∈ O) (mY : Y ∈ O) {f : X ⟶ Y}, ⟨X, ⟨Y, ⟨mX, ⟨mY, f⟩⟩⟩⟩ ∈ H → f ≫ i' mY = i' mX
i : {j j' : J} → (f : j ⟶ j') → kf f ⟶ k'' := fun {j j'} f ↦ i' ⋯
j₁ j₂ j₃ j₄ : J
f : j₁ ⟶ j₂
f' : j₃ ⟶ j₄
⊢ gf f ≫ i f = hf f' ≫ i f'
Module: Mathlib.CategoryTheory.Adhesive.Basic

Goal state before:
pp: case mp
C : Type u
inst✝ : Category.{v, u} C
W X Y Z : C
f : W ⟶ X
g : W ⟶ Y
h : X ⟶ Z
i : Y ⟶ Z
H : IsPushout f g h i
H' : H.IsVanKampen
X' Y' Z' : C
h' : X' ⟶ Z'
i' : Y' ⟶ Z'
αX : X' ⟶ X
αY : Y' ⟶ Y
αZ : Z' ⟶ Z
sq_h : CommSq h' αX αZ h
⊢ CommSq i' αY αZ i →
    ∀ [HasPullback αX f],
      IsPullback h' αX αZ h ∧ IsPullback i' αY αZ i ↔
        ∃ W' f' g' αW, IsPullback f' αW αX f ∧ IsPullback g' αW αY g ∧ IsPushout f' g' h' i'

Tactic:
sq_i

Goal state after:
case mp
C : Type u
inst✝ : Category.{v, u} C
W X Y Z : C
f : W ⟶ X
g : W ⟶ Y
h : X ⟶ Z
i : Y ⟶ Z
H : IsPushout f g h i
H' : H.IsVanKampen
X' Y' Z' : C
h' : X' ⟶ Z'
i' : Y' ⟶ Z'
αX : X' ⟶ X
αY : Y' ⟶ Y
αZ : Z' ⟶ Z
sq_h : CommSq h' αX αZ h
sq_i : CommSq i' αY αZ i
⊢ ∀ [HasPullback αX f],
    IsPullback h' αX αZ h ∧ IsPullback i' αY αZ i ↔
      ∃ W' f' g' αW, IsPullback f' αW αX f ∧ IsPullback g' αW αY g ∧ IsPushout f' g' h' i'
Module: Mathlib.CategoryTheory.Adhesive.Basic

Goal state before:
pp: case mpr
C : Type u
inst✝ : Category.{v, u} C
W X Y Z : C
f : W ⟶ X
g : W ⟶ Y
h : X ⟶ Z
i : Y ⟶ Z
H : IsPushout f g h i
H' :
  ∀ ⦃X' Y' Z' : C⦄ (h' : X' ⟶ Z') (i' : Y' ⟶ Z') (αX : X' ⟶ X) (αY : Y' ⟶ Y) (αZ : Z' ⟶ Z),
    CommSq h' αX αZ h →
      CommSq i' αY αZ i →
        ∀ [HasPullback αX f],
          IsPullback h' αX αZ h ∧ IsPullback i' αY αZ i ↔
            ∃ W' f' g' αW, IsPullback f' αW αX f ∧ IsPullback g' αW αY g ∧ IsPushout f' g' h' i'
W' X' Y' Z' : C
f' : W' ⟶ X'
g' : W' ⟶ Y'
h' : X' ⟶ Z'
i' : Y' ⟶ Z'
αW : W' ⟶ W
αX : X' ⟶ X
αY : Y' ⟶ Y
αZ : Z' ⟶ Z
hf : IsPullback f' αW αX f
hg : IsPullback g' αW αY g
sq_h : CommSq h' αX αZ h
⊢ CommSq i' αY αZ i → CommSq f' g' h' i' → (IsPushout f' g' h' i' ↔ IsPullback h' αX αZ h ∧ IsPullback i' αY αZ i)

Tactic:
sq_i

Goal state after:
case mpr
C : Type u
inst✝ : Category.{v, u} C
W X Y Z : C
f : W ⟶ X
g : W ⟶ Y
h : X ⟶ Z
i : Y ⟶ Z
H : IsPushout f g h i
H' :
  ∀ ⦃X' Y' Z' : C⦄ (h' : X' ⟶ Z') (i' : Y' ⟶ Z') (αX : X' ⟶ X) (αY : Y' ⟶ Y) (αZ : Z' ⟶ Z),
    CommSq h' αX αZ h →
      CommSq i' αY αZ i →
        ∀ [HasPullback αX f],
          IsPullback h' αX αZ h ∧ IsPullback i' αY αZ i ↔
            ∃ W' f' g' αW, IsPullback f' αW αX f ∧ IsPullback g' αW αY g ∧ IsPushout f' g' h' i'
W' X' Y' Z' : C
f' : W' ⟶ X'
g' : W' ⟶ Y'
h' : X' ⟶ Z'
i' : Y' ⟶ Z'
αW : W' ⟶ W
αX : X' ⟶ X
αY : Y' ⟶ Y
αZ : Z' ⟶ Z
hf : IsPullback f' αW αX f
hg : IsPullback g' αW αY g
sq_h : CommSq h' αX αZ h
sq_i : CommSq i' αY αZ i
⊢ CommSq f' g' h' i' → (IsPushout f' g' h' i' ↔ IsPullback h' αX αZ h ∧ IsPullback i' αY αZ i)
Module: Mathlib.CategoryTheory.Extensive

Goal state before:
pp: case neg
J : Type v'
inst✝² : Category.{u', v'} J
C : Type u
inst✝¹ : Category.{v, u} C
D : Type u''
inst✝ : Category.{v'', u''} D
X Y : C
Z : Type u
f : Z ⟶ (Types.binaryCoproductCocone PUnit.{u + 1} PUnit.{u + 1}).pt
this :
  ∀ (x : (fun X ↦ X) Z),
    (ConcreteCategory.hom f) x = Sum.inl PUnit.unit ∨ (ConcreteCategory.hom f) x = Sum.inr PUnit.unit
eX : { p // (ConcreteCategory.hom f) p.1 = Sum.inl p.2 } ≃ { x // (ConcreteCategory.hom f) x = Sum.inl PUnit.unit } :=
  { toFun := fun p ↦ ⟨(↑p).1, ⋯⟩, invFun := fun x ↦ ⟨(x.1, PUnit.unit), ⋯⟩, left_inv := ⋯, right_inv := ⋯ }
eY : { p // (ConcreteCategory.hom f) p.1 = Sum.inr p.2 } ≃ { x // (ConcreteCategory.hom f) x = Sum.inr PUnit.unit } :=
  { toFun := fun p ↦ ⟨(↑p).1, ⋯⟩, invFun := fun x ↦ ⟨(x.1, PUnit.unit), ⋯⟩, left_inv := ⋯, right_inv := ⋯ }
s : BinaryCofan (Types.PullbackObj f (↾Sum.inl)) (Types.PullbackObj f (↾Sum.inr))
m : Z ⟶ s.pt
e₁ : (↾fun p ↦ (↑p).1) ≫ m = s.inl
e₂ : (↾fun p ↦ (↑p).1) ≫ m = s.inr
x : Z
h✝ : ¬(ConcreteCategory.hom f) x = Sum.inl PUnit.unit
⊢ (ConcreteCategory.hom m) x = (ConcreteCategory.hom s.inr) (eY.symm ⟨x, ⋯⟩)

Tactic:
· rw [← e₂]
        rfl

Goal state after:
Module: Mathlib.CategoryTheory.Extensive

Goal state before:
pp: C : Type u
inst✝⁷ : Category.{v, u} C
D : Type u''
inst✝⁶ : Category.{v'', u''} D
F : C ⥤ D
inst✝⁵ : FinitaryExtensive D
inst✝⁴ : HasFiniteCoproducts C
inst✝³ : HasPullbacks C
inst✝² : PreservesLimitsOfShape WalkingCospan F
inst✝¹ : PreservesColimitsOfShape (Discrete WalkingPair) F
inst✝ : F.ReflectsIsomorphisms
⊢ FinitaryExtensive C

Tactic:
have : ReflectsLimitsOfShape WalkingCospan F := reflectsLimitsOfShape_of_reflectsIsomorphisms

Goal state after:
C : Type u
inst✝⁷ : Category.{v, u} C
D : Type u''
inst✝⁶ : Category.{v'', u''} D
F : C ⥤ D
inst✝⁵ : FinitaryExtensive D
inst✝⁴ : HasFiniteCoproducts C
inst✝³ : HasPullbacks C
inst✝² : PreservesLimitsOfShape WalkingCospan F
inst✝¹ : PreservesColimitsOfShape (Discrete WalkingPair) F
inst✝ : F.ReflectsIsomorphisms
this : ReflectsLimitsOfShape WalkingCospan F
⊢ FinitaryExtensive C
Module: Mathlib.CategoryTheory.ObjectProperty.Local

Goal state before:
pp: C : Type u
inst✝ : Category.{v, u} C
W W' : MorphismProperty C
X X' : C
e : X ≅ X'
hX : W.isColocal X
Y Z : C
g : Y ⟶ Z
hg : W g
⊢ Function.Bijective fun f ↦ f ≫ g

Tactic:
rw [← Function.Bijective.of_comp_iff _ (Iso.homFromEquiv e).bijective]
    convert! (Iso.homFromEquiv e).bijective.comp (hX g hg) using 1
    aesop

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

Goal state before:
pp: case mp.left
C : Type u
inst✝ : Category.{v, u} C
X Y : C
c : BinaryCofan X Y
cofans : (X Y : C) → BinaryCofan X Y
colimits : (X Y : C) → IsColimit (cofans X Y)
cones : {X Y Z : C} → (f : X ⟶ Z) → (g : Y ⟶ Z) → PullbackCone f g
limits : {X Y Z : C} → (f : X ⟶ Z) → (g : Y ⟶ Z) → IsLimit (cones f g)
h₁ :
  ∀ {X' Y' : C} (αX : X' ⟶ X) (αY : Y' ⟶ Y) (f : (cofans X' Y').pt ⟶ c.pt),
    αX ≫ c.inl = (cofans X' Y').inl ≫ f →
      αY ≫ c.inr = (cofans X' Y').inr ≫ f →
        IsPullback (cofans X' Y').inl αX f c.inl ∧ IsPullback (cofans X' Y').inr αY f c.inr
h₂ : {Z : C} → (f : Z ⟶ c.pt) → IsColimit (BinaryCofan.mk (cones f c.inl).fst (cones f c.inr).fst)
X' Y' : C
c' : BinaryCofan X' Y'
αX : X' ⟶ X
αY : Y' ⟶ Y
f : c'.pt ⟶ c.pt
hX : αX ≫ c.inl = c'.inl ≫ f
hY : αY ≫ c.inr = c'.inr ≫ f
h : IsColimit c'
e : c'.pt ≅ (cofans X' Y').pt := h.coconePointUniqueUpToIso (colimits X' Y')
hl : IsPullback (cofans X' Y').inl αX (e.inv ≫ f) c.inl
hr : IsPullback (cofans X' Y').inr αY (e.inv ≫ f) c.inr
this✝ : IsIso (𝟙 X')
this : c'.inl ≫ e.hom = 𝟙 X' ≫ (cofans X' Y').inl
⊢ IsPullback c'.inl (𝟙 X' ≫ αX) (e.hom ≫ e.inv ≫ f) c.inl

Tactic:
exact (IsPullback.of_vert_isIso ⟨this⟩).paste_vert hl

Goal state after:
Module: Mathlib.CategoryTheory.Abelian.Projective.Dimension

Goal state before:
pp: C : Type u
inst✝² : Category.{v, u} C
inst✝¹ : Abelian C
X : C
inst✝ : HasProjectiveDimensionLT X 0
this : HasExt C := HasExt.standard C
⊢ IsZero X

Tactic:
rw [IsZero.iff_id_eq_zero]

Goal state after:
C : Type u
inst✝² : Category.{v, u} C
inst✝¹ : Abelian C
X : C
inst✝ : HasProjectiveDimensionLT X 0
this : HasExt C := HasExt.standard C
⊢ 𝟙 X = 0
Module: Mathlib.CategoryTheory.Sites.Hypercover.Zero

Goal state before:
pp: case refine_1
C : Type u
inst✝¹ : Category.{v, u} C
S T : C
f : S ⟶ T
E : PreZeroHypercover T
inst✝ : ∀ (i : E.I₀), HasPullback (E.f i) f
⊢ (pullback₂ f E).presieve₀ ≤ Presieve.pullbackArrows f E.presieve₀

pp: case refine_2
C : Type u
inst✝¹ : Category.{v, u} C
S T : C
f : S ⟶ T
E : PreZeroHypercover T
inst✝ : ∀ (i : E.I₀), HasPullback (E.f i) f
⊢ Presieve.pullbackArrows f E.presieve₀ ≤ (pullback₂ f E).presieve₀

Tactic:
· rintro - - ⟨i⟩
    use _, _, i

Goal state after:
case refine_2
C : Type u
inst✝¹ : Category.{v, u} C
S T : C
f : S ⟶ T
E : PreZeroHypercover T
inst✝ : ∀ (i : E.I₀), HasPullback (E.f i) f
⊢ Presieve.pullbackArrows f E.presieve₀ ≤ (pullback₂ f E).presieve₀
Module: Mathlib.CategoryTheory.Sites.Hypercover.Zero

Goal state before:
pp: C : Type u
inst✝ : Category.{v, u} C
S : C
E : PreZeroHypercover S
F : PreZeroHypercover S
f : E.Hom F
i : E.I₀
⊢ F.sieve₀.arrows (E.f i)

Tactic:
← f.w₀ i

Goal state after:
C : Type u
inst✝ : Category.{v, u} C
S : C
E : PreZeroHypercover S
F : PreZeroHypercover S
f : E.Hom F
i : E.I₀
⊢ F.sieve₀.arrows (f.h₀ i ≫ F.f (f.s₀ i))
Module: Mathlib.CategoryTheory.Sites.Hypercover.IsSheaf

Goal state before:
pp: C : Type u
inst✝² : Category.{v, u} C
J : GrothendieckTopology C
A : Type u'
inst✝¹ : Category.{v', u'} A
H : J.OneHypercoverFamily
P : Cᵒᵖ ⥤ A
inst✝ : H.IsGenerating
⊢ Presheaf.IsSheaf J P ↔ ∀ ⦃X : C⦄ (E : J.OneHypercover X), H E → Nonempty (IsLimit (E.multifork P))

Tactic:
constructor
  · intro hP X E _
    exact ⟨E.isLimitMultifork ⟨_, hP⟩⟩
  · intro hP
    rw [Presheaf.isSheaf_iff_multifork]
    rintro X ⟨S, hS⟩
    obtain ⟨E, hE, le⟩ := H.exists_oneHypercover S hS
    exact ⟨IsSheafIff.isLimit hP hE le⟩

Goal state after:
Module: Mathlib.CategoryTheory.Sites.LocallyFullyFaithful

Goal state before:
pp: C : Type uC
inst✝² : Category.{vC, uC} C
D : Type uD
inst✝¹ : Category.{vD, uD} D
K : GrothendieckTopology D
G : C ⥤ D
inst✝ : G.IsLocallyFaithful K
ℱ : Sheaf K (Type u_2)
X Y : C
i₁ i₂ : X ⟶ Y
e : G.map i₁ = G.map i₂
s t : ℱ.obj.obj (op (G.obj X))
h :
  ∀ ⦃Z : C⦄ (j : Z ⟶ X),
    j ≫ i₁ = j ≫ i₂ →
      (ConcreteCategory.hom (ℱ.obj.map (G.map j).op)) s = (ConcreteCategory.hom (ℱ.obj.map (G.map j).op)) t
Z : D
W : C
iWX : W ⟶ X
iZW : Z ⟶ G.obj W
hiWX : (Sieve.equalizer i₁ i₂).arrows iWX
⊢ (ConcreteCategory.hom (ℱ.obj.map (iZW ≫ G.map iWX).op)) s = (ConcreteCategory.hom (ℱ.obj.map (iZW ≫ G.map iWX).op)) t

Tactic:
simp [h iWX hiWX]

Goal state after:
Module: Mathlib.CategoryTheory.Sites.Hypercover.One

Goal state before:
pp: case h₁.h₀
C : Type u
inst✝¹ : Category.{v, u} C
S : C
E : PreOneHypercover S
F : PreOneHypercover S
inst✝ : HasPullbacks C
i j : E.I₀ × F.I₀
W : C
p₁ : W ⟶ pullback (E.f i.1) (F.f i.2)
p₂ : W ⟶ pullback (E.f j.1) (F.f j.2)
w : p₁ ≫ pullback.fst (E.f i.1) (F.f i.2) ≫ E.f i.1 = p₂ ≫ pullback.fst (E.f j.1) (F.f j.2) ≫ E.f j.1
Y : C
f : Y ⟶ W
p : W ⟶ pullback ((E.inter F).f i) ((E.inter F).f j) := ⋯
x✝ : ((E.inter F).sieve₁ p₁ p₂).arrows f
k : (E.inter F).I₁ i j
a : Y ⟶ (E.inter F).Y k
h₁ : f ≫ p₁ = a ≫ (E.inter F).p₁ k
h₂ : f ≫ p₂ = a ≫ (E.inter F).p₂ k
⊢ ((f ≫ p) ≫ pullback.snd ((E.inter F).f i) ((E.inter F).f j)) ≫
      pullback.fst (E.f ((Equiv.sigmaEquivProd E.I₀ F.toPreZeroHypercover.1).symm j).fst)
        (F.f ((Equiv.sigmaEquivProd E.I₀ F.toPreZeroHypercover.1).symm j).snd) =
    ((a ≫ (E.inter F).toPullback k) ≫ pullback.snd ((E.inter F).f i) ((E.inter F).f j)) ≫
      pullback.fst (E.f ((Equiv.sigmaEquivProd E.I₀ F.toPreZeroHypercover.1).symm j).fst)
        (F.f ((Equiv.sigmaEquivProd E.I₀ F.toPreZeroHypercover.1).symm j).snd)

Tactic:
simp [p, h₂, toPullback]

Goal state after:
Module: Mathlib.CategoryTheory.Sites.Hypercover.One

Goal state before:
pp: case h₁
C : Type u
inst✝¹ : Category.{v, u} C
S : C
E : PreOneHypercover S
F : PreOneHypercover S
inst✝ : HasPullbacks C
i j : E.I₀ × F.I₀
W : C
p₁ : W ⟶ pullback (E.f i.1) (F.f i.2)
p₂ : W ⟶ pullback (E.f j.1) (F.f j.2)
w : p₁ ≫ pullback.fst (E.f i.1) (F.f i.2) ≫ E.f i.1 = p₂ ≫ pullback.fst (E.f j.1) (F.f j.2) ≫ E.f j.1
Y : C
f : Y ⟶ W
p : W ⟶ pullback ((E.inter F).f i) ((E.inter F).f j) := ⋯
x✝ : ((E.inter F).sieve₁ p₁ p₂).arrows f
k : (E.inter F).I₁ i j
a : Y ⟶ (E.inter F).Y k
h₁ : f ≫ p₁ = a ≫ (E.inter F).p₁ k
h₂ : f ≫ p₂ = a ≫ (E.inter F).p₂ k
⊢ ((f ≫ p) ≫ pullback.snd ((E.inter F).f i) ((E.inter F).f j)) ≫
      pullback.snd (E.f ((Equiv.sigmaEquivProd E.I₀ F.toPreZeroHypercover.1).symm j).fst)
        (F.f ((Equiv.sigmaEquivProd E.I₀ F.toPreZeroHypercover.1).symm j).snd) =
    ((a ≫ (E.inter F).toPullback k) ≫ pullback.snd ((E.inter F).f i) ((E.inter F).f j)) ≫
      pullback.snd (E.f ((Equiv.sigmaEquivProd E.I₀ F.toPreZeroHypercover.1).symm j).fst)
        (F.f ((Equiv.sigmaEquivProd E.I₀ F.toPreZeroHypercover.1).symm j).snd)

Tactic:
simp [p, h₂, toPullback]

Goal state after: