mathlib-initiative/mathlib-tactics huggingface dataset:
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),
    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:
αX

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),
    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'
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),
    IsPullback f' αW αX f →
      IsPullback g' αW αY g →
        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:
αX

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),
    IsPullback f' αW αX f →
      IsPullback g' αW αY g →
        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)
Module: Mathlib.CategoryTheory.Extensive

Goal state before:
pp: case h₁
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
X' Y' : TopCat
⊢ ∀ (αX : X' ⟶ TopCat.of PUnit.{u + 1}) (αY : Y' ⟶ TopCat.of PUnit.{u + 1})
    (f : (X'.binaryCofan Y').pt ⟶ ((TopCat.of PUnit.{u + 1}).binaryCofan (TopCat.of PUnit.{u + 1})).pt),
    αX ≫ ((TopCat.of PUnit.{u + 1}).binaryCofan (TopCat.of PUnit.{u + 1})).inl = (X'.binaryCofan Y').inl ≫ f →
      αY ≫ ((TopCat.of PUnit.{u + 1}).binaryCofan (TopCat.of PUnit.{u + 1})).inr = (X'.binaryCofan Y').inr ≫ f →
        IsPullback (X'.binaryCofan Y').inl αX f ((TopCat.of PUnit.{u + 1}).binaryCofan (TopCat.of PUnit.{u + 1})).inl ∧
          IsPullback (X'.binaryCofan Y').inr αY f ((TopCat.of PUnit.{u + 1}).binaryCofan (TopCat.of PUnit.{u + 1})).inr

Tactic:
αX

Goal state after:
case h₁
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
X' Y' : TopCat
αX : X' ⟶ TopCat.of PUnit.{u + 1}
⊢ ∀ (αY : Y' ⟶ TopCat.of PUnit.{u + 1})
    (f : (X'.binaryCofan Y').pt ⟶ ((TopCat.of PUnit.{u + 1}).binaryCofan (TopCat.of PUnit.{u + 1})).pt),
    αX ≫ ((TopCat.of PUnit.{u + 1}).binaryCofan (TopCat.of PUnit.{u + 1})).inl = (X'.binaryCofan Y').inl ≫ f →
      αY ≫ ((TopCat.of PUnit.{u + 1}).binaryCofan (TopCat.of PUnit.{u + 1})).inr = (X'.binaryCofan Y').inr ≫ f →
        IsPullback (X'.binaryCofan Y').inl αX f ((TopCat.of PUnit.{u + 1}).binaryCofan (TopCat.of PUnit.{u + 1})).inl ∧
          IsPullback (X'.binaryCofan Y').inr αY f ((TopCat.of PUnit.{u + 1}).binaryCofan (TopCat.of PUnit.{u + 1})).inr
Module: Mathlib.CategoryTheory.Adhesive.Basic

Goal state before:
pp: case fac_left
C : Type u
inst✝ : Category.{v, u} C
X E Y YE : C
c : BinaryCofan X E
hc : IsColimit c
f : X ⟶ Y
iY : Y ⟶ YE
fE : c.pt ⟶ YE
H✝ : CommSq f c.inl iY fE
H : IsPushout f c.inl iY fE
⊢ ∀ (s : BinaryCofan ((pair X E).obj { as := WalkingPair.right }) Y),
    (c.inr ≫ fE) ≫ H.isColimit.desc (PushoutCocone.mk s.inr (hc.desc (BinaryCofan.mk (f ≫ s.inr) s.inl)) ⋯) = s.inl

Tactic:
intro s
      rw [Category.assoc]
      erw [H.isColimit.fac _ WalkingSpan.right]
      erw [hc.fac]
      rfl

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

Goal state before:
pp: case e_a
C : Type u
inst✝¹² : Category.{v, u} C
J : GrothendieckTopology C
D : Type w
inst✝¹¹ : Category.{t, w} D
inst✝¹⁰ : ∀ (P : Cᵒᵖ ⥤ D) (X : C) (S : J.Cover X), HasMultiequalizer (S.index P)
inst✝⁹ : ∀ (X : C), HasColimitsOfShape (J.Cover X)ᵒᵖ D
FD : D → D → Type u_1
CD : D → Type t
inst✝⁸ : (X Y : D) → FunLike (FD X Y) (CD X) (CD Y)
inst✝⁷ : ConcreteCategory D FD
inst✝⁶ : ∀ (X : C), PreservesColimitsOfShape (J.Cover X)ᵒᵖ (forget D)
inst✝⁵ : ∀ (X : C), Small.{t, max u v} (J.Cover X)ᵒᵖ
K : Type s
inst✝⁴ : SmallCategory K
inst✝³ : FinCategory K
inst✝² : HasLimitsOfShape K D
inst✝¹ : PreservesLimitsOfShape K (forget D)
inst✝ : ReflectsLimitsOfShape K (forget D)
F : K ⥤ Cᵒᵖ ⥤ D
X : C
S : Cone (F ⋙ J.plusFunctor D ⋙ (evaluation Cᵒᵖ D).obj (op X))
k : K
j : (J.Cover (unop (op X)))ᵒᵖ
⊢ colimit.ι (J.diagram (limit F) X) j ≫ colimMap (J.diagramNatTrans (limit.π F k) X) =
    colimit.ι (J.diagram (limit F) X) j ≫
      (HasColimit.isoOfNatIso
            ((isLimitOfPreserves (J.diagramFunctor D X) (limit.isLimit F)).conePointUniqueUpToIso
              (limit.isLimit (F ⋙ J.diagramFunctor D X)))).hom ≫
        (colimitLimitIso (F ⋙ J.diagramFunctor D X)).hom ≫
          (HasLimit.isoOfNatIso
                (NatIso.ofComponents (fun k ↦ colimitObjIsoColimitCompEvaluation (F ⋙ J.diagramFunctor D X).flip k)
                    ⋯).symm).inv ≫
            limit.π (F ⋙ J.plusFunctor D ⋙ (evaluation Cᵒᵖ D).obj (op X)) k

Tactic:
simp only [HasColimit.isoOfNatIso_ι_hom_assoc, ι_colimMap]

Goal state after:
case e_a
C : Type u
inst✝¹² : Category.{v, u} C
J : GrothendieckTopology C
D : Type w
inst✝¹¹ : Category.{t, w} D
inst✝¹⁰ : ∀ (P : Cᵒᵖ ⥤ D) (X : C) (S : J.Cover X), HasMultiequalizer (S.index P)
inst✝⁹ : ∀ (X : C), HasColimitsOfShape (J.Cover X)ᵒᵖ D
FD : D → D → Type u_1
CD : D → Type t
inst✝⁸ : (X Y : D) → FunLike (FD X Y) (CD X) (CD Y)
inst✝⁷ : ConcreteCategory D FD
inst✝⁶ : ∀ (X : C), PreservesColimitsOfShape (J.Cover X)ᵒᵖ (forget D)
inst✝⁵ : ∀ (X : C), Small.{t, max u v} (J.Cover X)ᵒᵖ
K : Type s
inst✝⁴ : SmallCategory K
inst✝³ : FinCategory K
inst✝² : HasLimitsOfShape K D
inst✝¹ : PreservesLimitsOfShape K (forget D)
inst✝ : ReflectsLimitsOfShape K (forget D)
F : K ⥤ Cᵒᵖ ⥤ D
X : C
S : Cone (F ⋙ J.plusFunctor D ⋙ (evaluation Cᵒᵖ D).obj (op X))
k : K
j : (J.Cover (unop (op X)))ᵒᵖ
⊢ (J.diagramNatTrans (limit.π F k) X).app j ≫ colimit.ι (J.diagram (F.obj k) X) j =
    ((isLimitOfPreserves (J.diagramFunctor D X) (limit.isLimit F)).conePointUniqueUpToIso
              (limit.isLimit (F ⋙ J.diagramFunctor D X))).hom.app
        j ≫
      colimit.ι (limit (F ⋙ J.diagramFunctor D X)) j ≫
        (colimitLimitIso (F ⋙ J.diagramFunctor D X)).hom ≫
          (HasLimit.isoOfNatIso
                (NatIso.ofComponents (fun k ↦ colimitObjIsoColimitCompEvaluation (F ⋙ J.diagramFunctor D X).flip k)
                    ⋯).symm).inv ≫
            limit.π (F ⋙ J.plusFunctor D ⋙ (evaluation Cᵒᵖ D).obj (op X)) k
Module: Mathlib.CategoryTheory.Localization.Adjunction

Goal state before:
pp: C₁ : Type u_1
C₂ : Type u_2
D₁ : Type u_3
D₂ : Type u_4
inst✝⁷ : Category.{v_1, u_1} C₁
inst✝⁶ : Category.{v_2, u_2} C₂
inst✝⁵ : Category.{v_3, u_3} D₁
inst✝⁴ : Category.{v_4, u_4} D₂
G : C₁ ⥤ C₂
F : C₂ ⥤ C₁
adj : G ⊣ F
L₁ : C₁ ⥤ D₁
W₁ : MorphismProperty C₁
inst✝³ : L₁.IsLocalization W₁
L₂ : C₂ ⥤ D₂
W₂ : MorphismProperty C₂
inst✝² : L₂.IsLocalization W₂
G' : D₁ ⥤ D₂
F' : D₂ ⥤ D₁
inst✝¹ : CatCommSq G L₁ L₂ G'
inst✝ : CatCommSq F L₂ L₁ F'
⊢ F' ⋙ G' ⟶ 𝟭 D₂

Tactic:
letI : Lifting L₂ W₂ ((F ⋙ G) ⋙ L₂) (F' ⋙ G') :=
    Lifting.mk (CatCommSq.hComp F G L₂ L₁ L₂ F' G').iso.symm

Goal state after:
C₁ : Type u_1
C₂ : Type u_2
D₁ : Type u_3
D₂ : Type u_4
inst✝⁷ : Category.{v_1, u_1} C₁
inst✝⁶ : Category.{v_2, u_2} C₂
inst✝⁵ : Category.{v_3, u_3} D₁
inst✝⁴ : Category.{v_4, u_4} D₂
G : C₁ ⥤ C₂
F : C₂ ⥤ C₁
adj : G ⊣ F
L₁ : C₁ ⥤ D₁
W₁ : MorphismProperty C₁
inst✝³ : L₁.IsLocalization W₁
L₂ : C₂ ⥤ D₂
W₂ : MorphismProperty C₂
inst✝² : L₂.IsLocalization W₂
G' : D₁ ⥤ D₂
F' : D₂ ⥤ D₁
inst✝¹ : CatCommSq G L₁ L₂ G'
inst✝ : CatCommSq F L₂ L₁ F'
this : Lifting L₂ W₂ ((F ⋙ G) ⋙ L₂) (F' ⋙ G') := { iso := (CatCommSq.iso (F ⋙ G) L₂ L₂ (F' ⋙ G')).symm }
⊢ F' ⋙ G' ⟶ 𝟭 D₂
Module: Mathlib.CategoryTheory.Localization.Bousfield

Goal state before:
pp: C : Type u_1
D : Type u_2
inst✝³ : Category.{v_1, u_1} C
inst✝² : Category.{v_2, u_2} D
F : C ⥤ D
G : D ⥤ C
adj : G ⊣ F
inst✝¹ : G.Full
inst✝ : G.Faithful
X Y : C
f : X ⟶ Y
this : G.map (F.map f) ≫ adj.counit.app Y = adj.counit.app X ≫ f
⊢ isColocal (fun x ↦ x ∈ Set.range G.obj) (G.map (F.map f)) ↔ IsIso (F.map f)

Tactic:
isColocal_iff_isIso _ _ ⟨_, rfl⟩ ⟨_, rfl⟩

Goal state after:
C : Type u_1
D : Type u_2
inst✝³ : Category.{v_1, u_1} C
inst✝² : Category.{v_2, u_2} D
F : C ⥤ D
G : D ⥤ C
adj : G ⊣ F
inst✝¹ : G.Full
inst✝ : G.Faithful
X Y : C
f : X ⟶ Y
this : G.map (F.map f) ≫ adj.counit.app Y = adj.counit.app X ≫ f
⊢ IsIso (G.map (F.map f)) ↔ IsIso (F.map f)
Module: Mathlib.CategoryTheory.Sites.Localization

Goal state before:
pp: C : Type u_1
inst✝² : Category.{v_1, u_1} C
J : GrothendieckTopology C
D : Type u_3
inst✝¹ : Category.{v_3, u_3} D
K : GrothendieckTopology D
inst✝ : LocallySmall.{w, v_1, u_1} C
F : C ⥤ D
H : (Cᵒᵖ ⥤ Type w) ⥤ Dᵒᵖ ⥤ Type w
adj : H ⊣ (Functor.whiskeringLeft Cᵒᵖ Dᵒᵖ (Type w)).obj F.op
h : ∀ ⦃X : C⦄ ⦃S : Sieve X⦄, S ∈ J X → K.W (H.map (Sieve.shrinkFunctor.{w, v_1, u_1} S).ι)
G : Dᵒᵖ ⥤ Type w
hG : IsSheaf K G
X : C
S : Sieve X
hS : S ∈ J X
⊢ Function.Bijective fun g ↦ (Sieve.shrinkFunctor.{w, v_1, u_1} S).ι ≫ g

Tactic:
← adj.map_comp_bijective_iff

Goal state after:
C : Type u_1
inst✝² : Category.{v_1, u_1} C
J : GrothendieckTopology C
D : Type u_3
inst✝¹ : Category.{v_3, u_3} D
K : GrothendieckTopology D
inst✝ : LocallySmall.{w, v_1, u_1} C
F : C ⥤ D
H : (Cᵒᵖ ⥤ Type w) ⥤ Dᵒᵖ ⥤ Type w
adj : H ⊣ (Functor.whiskeringLeft Cᵒᵖ Dᵒᵖ (Type w)).obj F.op
h : ∀ ⦃X : C⦄ ⦃S : Sieve X⦄, S ∈ J X → K.W (H.map (Sieve.shrinkFunctor.{w, v_1, u_1} S).ι)
G : Dᵒᵖ ⥤ Type w
hG : IsSheaf K G
X : C
S : Sieve X
hS : S ∈ J X
⊢ Function.Bijective fun g ↦ H.map (Sieve.shrinkFunctor.{w, v_1, u_1} S).ι ≫ g
Module: Mathlib.CategoryTheory.Sites.LocallySurjective

Goal state before:
pp: case refine_2
C : Type u
inst✝⁵ : Category.{v, u} C
J : GrothendieckTopology C
A : Type u'
inst✝⁴ : Category.{v', u'} A
FA : A → A → Type u_1
CA : A → Type w'
inst✝³ : (X Y : A) → FunLike (FA X Y) (CA X) (CA Y)
inst✝² : ConcreteCategory A FA
F₁ F₂ F₃ : Cᵒᵖ ⥤ A
f₁ : F₁ ⟶ F₂
f₂ : F₂ ⟶ F₃
inst✝¹ : IsLocallySurjective J (f₁ ≫ f₂)
inst✝ : IsLocallyInjective J f₂
X : C
x : ToType (F₂.obj (op X))
S : Sieve X := imageSieve (f₁ ≫ f₂) ((ConcreteCategory.hom (f₂.app (op X))) x)
T : ⦃Y : C⦄ → (f : Y ⟶ X) → S.arrows f → Sieve Y :=
  fun Y f hf ↦
    equalizerSieve
      ((ConcreteCategory.hom (f₁.app (op Y))) (localPreimage (f₁ ≫ f₂) ((ConcreteCategory.hom (f₂.app (op X))) x) f hf))
      ((ConcreteCategory.hom (F₂.map f.op)) x)
⊢ ∀ ⦃Y : C⦄ ⦃f : Y ⟶ unop (op X)⦄,
    (imageSieve (f₁ ≫ f₂) ((ConcreteCategory.hom (f₂.app (op X))) x)).arrows f →
      Sieve.pullback f (Sieve.bind S.arrows T) ∈ J Y

Tactic:
· intro Y f hf
      apply J.superset_covering (Sieve.le_pullback_bind _ _ _ hf)
      apply equalizerSieve_mem J f₂
      rw [NatTrans.naturality_apply, ← app_localPreimage (f₁ ≫ f₂) _ _ hf,
        NatTrans.comp_app, ConcreteCategory.comp_apply]

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

Goal state before:
pp: C : Type u
inst✝ : Category.{v, u} C
J : GrothendieckTopology C
F G : Sheaf J (Type w)
f : F ⟶ G
⊢ Presheaf.IsLocallySurjective J f.hom ↔ IsIso { hom := (Subfunctor.sheafify J (Subfunctor.range f.hom)).ι }

Tactic:
Presheaf.isLocallySurjective_iff_range_sheafify_eq_top',

Goal state after:
C : Type u
inst✝ : Category.{v, u} C
J : GrothendieckTopology C
F G : Sheaf J (Type w)
f : F ⟶ G
⊢ Subfunctor.sheafify J (Subfunctor.range f.hom) = ⊤ ↔
    IsIso { hom := (Subfunctor.sheafify J (Subfunctor.range f.hom)).ι }
Module: Mathlib.CategoryTheory.Sites.Closed

Goal state before:
pp: case refine_1
C : Type u
inst✝ : Category.{v, u} C
J₁ : GrothendieckTopology C
X : C
S : Sieve X
hS : S ∈ J₁ X
x : Presieve.FamilyOfElements (Functor.closedSieves J₁).toFunctor S.arrows
M : Sieve X
hM : M ∈ (Functor.closedSieves J₁).obj (Opposite.op X)
N : Sieve X
hN : N ∈ (Functor.closedSieves J₁).obj (Opposite.op X)
hM₂ : x.IsAmalgamation ⟨M, hM⟩
hN₂ : x.IsAmalgamation ⟨N, hN⟩
Y : C
f : Y ⟶ X
⊢ J₁.Covers M f ↔ J₁.Covers N f

Tactic:
have q : ∀ ⦃Z : C⦄ (g : Z ⟶ X) (_ : S g), M.pullback g = N.pullback g :=
      fun Z g hg => congr_arg Subtype.val ((hM₂ g hg).trans (hN₂ g hg).symm)

Goal state after:
case refine_1
C : Type u
inst✝ : Category.{v, u} C
J₁ : GrothendieckTopology C
X : C
S : Sieve X
hS : S ∈ J₁ X
x : Presieve.FamilyOfElements (Functor.closedSieves J₁).toFunctor S.arrows
M : Sieve X
hM : M ∈ (Functor.closedSieves J₁).obj (Opposite.op X)
N : Sieve X
hN : N ∈ (Functor.closedSieves J₁).obj (Opposite.op X)
hM₂ : x.IsAmalgamation ⟨M, hM⟩
hN₂ : x.IsAmalgamation ⟨N, hN⟩
Y : C
f : Y ⟶ X
q : ∀ ⦃Z : C⦄ (g : Z ⟶ X), S.arrows g → Sieve.pullback g M = Sieve.pullback g N
⊢ J₁.Covers M f ↔ J₁.Covers N f
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

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

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

Goal state before:
pp: case a
C : Type u
inst✝ : Category.{v, u} C
J₁ : GrothendieckTopology C
X : C
S : Sieve X
hS : S ∈ J₁ X
x : Presieve.FamilyOfElements (Functor.closedSieves J₁).toFunctor S.arrows
hx : x.SieveCompatible
M : Sieve X := Sieve.bind S.arrows fun Y f hf ↦ ↑(x f hf)
Y : C
f : Y ⟶ X
hf : S.arrows f
Z : C
u : Z ⟶ Y
W : C
g : Z ⟶ W
f' : W ⟶ X
hf' : S.arrows f'
hg : (↑(x f' hf')).arrows g
c : g ≫ f' = u ≫ f
⊢ ↑((ConcreteCategory.hom ((Functor.closedSieves J₁).toFunctor.map g.op)) (x f' hf')) = ⊤

Tactic:
apply Sieve.pullback_eq_top_of_mem _ hg

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

Goal state before:
pp: case mp
C : Type u
inst✝ : Category.{v, u} C
J₁ J₂ : GrothendieckTopology C
⊢ J₁ = J₂ → ∀ (P : Cᵒᵖ ⥤ Type (max v u)), Presieve.IsSheaf J₁ P ↔ Presieve.IsSheaf J₂ P

pp: case mpr
C : Type u
inst✝ : Category.{v, u} C
J₁ J₂ : GrothendieckTopology C
⊢ (∀ (P : Cᵒᵖ ⥤ Type (max v u)), Presieve.IsSheaf J₁ P ↔ Presieve.IsSheaf J₂ P) → J₁ = J₂

Tactic:
· rintro rfl
    intro P
    rfl

Goal state after:
case mpr
C : Type u
inst✝ : Category.{v, u} C
J₁ J₂ : GrothendieckTopology C
⊢ (∀ (P : Cᵒᵖ ⥤ Type (max v u)), Presieve.IsSheaf J₁ P ↔ Presieve.IsSheaf J₂ P) → J₁ = J₂
Module: Mathlib.CategoryTheory.Sites.Hypercover.Zero

Goal state before:
pp: C : Type u
inst✝ : Category.{v, u} C
S : C
E F : PreZeroHypercover S
⊢ E.presieve₀ = F.presieve₀ ↔ E.shrink = F.shrink

Tactic:
by
  refine ⟨fun h ↦ shrink_eq_shrink_of_presieve₀_eq_presieve₀ h, fun h ↦ ?_⟩
  rw [← E.presieve₀_shrink, ← F.presieve₀_shrink, h]

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

Goal state before:
pp: C : Type u_1
inst✝ : Category.{v_1, u_1} C
X : C
S T : Presieve X
⊢ S.FactorsThruAlong T (𝟙 X) ↔ S.FactorsThru T

Tactic:
by
  simp [FactorsThruAlong, FactorsThru]

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

Goal state before:
pp: case refine_2
C : Type u_2
inst✝ : Category.{v_1, u_2} C
X : C
S T : Presieve X
P : Cᵒᵖ ⥤ Type u_1
h : ∀ ⦃Y : C⦄ ⦃f : Y ⟶ X⦄, T f → ∃ R, IsSeparatedFor P R ∧ R.FactorsThruAlong S f
hS : IsSeparatedFor P S ∧ ∀ (x : FamilyOfElements P S), x.Compatible → ∃ t, x.IsAmalgamation t
W : ⦃Z : C⦄ → ⦃g : Z ⟶ X⦄ → S g → C
i : ⦃Z : C⦄ → ⦃g : Z ⟶ X⦄ → (a : S g) → Z ⟶ W a
e : ⦃Z : C⦄ → ⦃g : Z ⟶ X⦄ → (a : S g) → W a ⟶ X
h1 : ∀ ⦃Z : C⦄ ⦃g : Z ⟶ X⦄ (a : S g), T (e a)
h2 : ∀ ⦃Z : C⦄ ⦃g : Z ⟶ X⦄ (a : S g), i a ≫ e a = g
x : FamilyOfElements P T
hx : x.Compatible
y : FamilyOfElements P S := fun Y g hg ↦ (ConcreteCategory.hom (P.map (i hg).op)) (x (e hg) ⋯)
hy : y.Compatible
left✝ : IsSeparatedFor P S
h2' : ∀ (x : FamilyOfElements P S), x.Compatible → ∃ t, x.IsAmalgamation t
z : P.obj (Opposite.op X)
hz : y.IsAmalgamation z
Y : C
g : Y ⟶ X
hg : T g
R : Presieve Y
hR1 : IsSeparatedFor P R
WW : ⦃Z : C⦄ → ⦃g : Z ⟶ Y⦄ → R g → C
ii : ⦃Z : C⦄ → ⦃g : Z ⟶ Y⦄ → (a : R g) → Z ⟶ WW a
ee : ⦃Z : C⦄ → ⦃g : Z ⟶ Y⦄ → (a : R g) → WW a ⟶ X
hh1 : ∀ ⦃Z : C⦄ ⦃g : Z ⟶ Y⦄ (a : R g), S (ee a)
hh2 : ∀ ⦃Z : C⦄ ⦃g_1 : Z ⟶ Y⦄ (a : R g_1), ii a ≫ ee a = g_1 ≫ g
Q : C
t : Q ⟶ Y
ht : R t
⊢ (ConcreteCategory.hom (P.map (ii ht).op)) ((ConcreteCategory.hom (P.map (ee ht).op)) z) =
    (ConcreteCategory.hom (P.map t.op)) (x g hg)

Tactic:
hz _ (hh1 _),

Goal state after:
case refine_2
C : Type u_2
inst✝ : Category.{v_1, u_2} C
X : C
S T : Presieve X
P : Cᵒᵖ ⥤ Type u_1
h : ∀ ⦃Y : C⦄ ⦃f : Y ⟶ X⦄, T f → ∃ R, IsSeparatedFor P R ∧ R.FactorsThruAlong S f
hS : IsSeparatedFor P S ∧ ∀ (x : FamilyOfElements P S), x.Compatible → ∃ t, x.IsAmalgamation t
W : ⦃Z : C⦄ → ⦃g : Z ⟶ X⦄ → S g → C
i : ⦃Z : C⦄ → ⦃g : Z ⟶ X⦄ → (a : S g) → Z ⟶ W a
e : ⦃Z : C⦄ → ⦃g : Z ⟶ X⦄ → (a : S g) → W a ⟶ X
h1 : ∀ ⦃Z : C⦄ ⦃g : Z ⟶ X⦄ (a : S g), T (e a)
h2 : ∀ ⦃Z : C⦄ ⦃g : Z ⟶ X⦄ (a : S g), i a ≫ e a = g
x : FamilyOfElements P T
hx : x.Compatible
y : FamilyOfElements P S := fun Y g hg ↦ (ConcreteCategory.hom (P.map (i hg).op)) (x (e hg) ⋯)
hy : y.Compatible
left✝ : IsSeparatedFor P S
h2' : ∀ (x : FamilyOfElements P S), x.Compatible → ∃ t, x.IsAmalgamation t
z : P.obj (Opposite.op X)
hz : y.IsAmalgamation z
Y : C
g : Y ⟶ X
hg : T g
R : Presieve Y
hR1 : IsSeparatedFor P R
WW : ⦃Z : C⦄ → ⦃g : Z ⟶ Y⦄ → R g → C
ii : ⦃Z : C⦄ → ⦃g : Z ⟶ Y⦄ → (a : R g) → Z ⟶ WW a
ee : ⦃Z : C⦄ → ⦃g : Z ⟶ Y⦄ → (a : R g) → WW a ⟶ X
hh1 : ∀ ⦃Z : C⦄ ⦃g : Z ⟶ Y⦄ (a : R g), S (ee a)
hh2 : ∀ ⦃Z : C⦄ ⦃g_1 : Z ⟶ Y⦄ (a : R g_1), ii a ≫ ee a = g_1 ≫ g
Q : C
t : Q ⟶ Y
ht : R t
⊢ (ConcreteCategory.hom (P.map (ii ht).op)) (y (ee ht) ⋯) = (ConcreteCategory.hom (P.map t.op)) (x g hg)
Module: Mathlib.CategoryTheory.Sites.Continuous

Goal state before:
pp: case refine_2.refine_2
C : Type u₁
inst✝³ : Category.{v₁, u₁} C
D : Type u₂
inst✝² : Category.{v₂, u₂} D
X : C
E : PreOneHypercover X
F : C ⥤ D
i₁ i₂ : E.I₀
inst✝¹ : HasPullback (E.f i₁) (E.f i₂)
inst✝ : PreservesLimit (cospan (E.f i₁) (E.f i₂)) F
this : HasPullback ((E.map F).f i₁) ((E.map F).f i₂)
W : D
f : W ⟶ F.obj (pullback (E.f i₁) (E.f i₂))
Y : D
k : (E.map F).I₁ i₁ i₂
u : W ⟶ (E.map F).Y k
h :
  u ≫ (E.map F).toPullback k =
    f ≫ pullback.lift (F.map (pullback.fst (E.f i₁) (E.f i₂))) (F.map (pullback.snd (E.f i₁) (E.f i₂))) ⋯
⊢ f = u ≫ F.map (pullback.lift (E.p₁ k) (E.p₂ k) ⋯)

Tactic:
simp only [pullback.hom_ext_iff, Category.assoc, limit.lift_π, PullbackCone.mk_π_app] at h

Goal state after:
case refine_2.refine_2
C : Type u₁
inst✝³ : Category.{v₁, u₁} C
D : Type u₂
inst✝² : Category.{v₂, u₂} D
X : C
E : PreOneHypercover X
F : C ⥤ D
i₁ i₂ : E.I₀
inst✝¹ : HasPullback (E.f i₁) (E.f i₂)
inst✝ : PreservesLimit (cospan (E.f i₁) (E.f i₂)) F
this : HasPullback ((E.map F).f i₁) ((E.map F).f i₂)
W : D
f : W ⟶ F.obj (pullback (E.f i₁) (E.f i₂))
Y : D
k : (E.map F).I₁ i₁ i₂
u : W ⟶ (E.map F).Y k
h :
  u ≫ (E.map F).p₁ k = f ≫ F.map (pullback.fst (E.f i₁) (E.f i₂)) ∧
    u ≫ (E.map F).p₂ k = f ≫ F.map (pullback.snd (E.f i₁) (E.f i₂))
⊢ f = u ≫ F.map (pullback.lift (E.p₁ k) (E.p₂ k) ⋯)
Module: Mathlib.CategoryTheory.Sites.DenseSubsite.Basic

Goal state before:
pp: C : Type u_1
inst✝⁵ : Category.{v_1, u_1} C
D : Type u_2
inst✝⁴ : Category.{v_2, u_2} D
E : Type u_3
inst✝³ : Category.{v_3, u_3} E
J : GrothendieckTopology C
K : GrothendieckTopology D
L : GrothendieckTopology E
A : Type u_4
inst✝² : Category.{v_4, u_4} A
G : C ⥤ D
ℱ✝ : Dᵒᵖ ⥤ Type v
ℱ'✝ : Sheaf K (Type v)
α : G.op ⋙ ℱ✝ ⟶ G.op ⋙ ℱ'✝.obj
inst✝¹ : G.IsCoverDense K
inst✝ : G.IsLocallyFull K
ℱ ℱ' : Sheaf K (Type v)
i : G.op ⋙ ℱ.obj ≅ G.op ⋙ ℱ'.obj
X : D
⊢ appHom i.hom X ≫ appHom i.inv X = 𝟙 (ℱ.obj.obj (op X))

Tactic:
ext x
    apply Functor.IsCoverDense.ext G
    intro Y f
    simp

Goal state after:
Module: Mathlib.CategoryTheory.Sites.DenseSubsite.Basic

Goal state before:
pp: C : Type u_1
inst✝⁵ : Category.{v_1, u_1} C
D : Type u_2
inst✝⁴ : Category.{v_2, u_2} D
E : Type u_3
inst✝³ : Category.{v_3, u_3} E
J : GrothendieckTopology C
K : GrothendieckTopology D
L : GrothendieckTopology E
A : Type u_4
inst✝² : Category.{v_4, u_4} A
G : C ⥤ D
ℱ✝ : Dᵒᵖ ⥤ Type v
ℱ'✝ : Sheaf K (Type v)
α : G.op ⋙ ℱ✝ ⟶ G.op ⋙ ℱ'✝.obj
inst✝¹ : G.IsCoverDense K
inst✝ : G.IsLocallyFull K
ℱ ℱ' : Sheaf K (Type v)
i : G.op ⋙ ℱ.obj ≅ G.op ⋙ ℱ'.obj
X : D
⊢ appHom i.inv X ≫ appHom i.hom X = 𝟙 (ℱ'.obj.obj (op X))

Tactic:
ext x
    apply Functor.IsCoverDense.ext G
    intro Y f
    simp

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

Goal state before:
pp: C : Type u
inst✝¹ : Category.{v, u} C
A : Type u_1
inst✝ : Category.{v_1, u_1} A
S✝ : C
E✝¹ E✝ : PreOneHypercover S✝
F✝ : PreOneHypercover S✝
G : PreOneHypercover S✝
S : C
E F : PreOneHypercover S
s₀ : E.I₀ ≃ F.I₀
h₀ : (i : E.I₀) → E.X i ≅ F.X (s₀ i)
s₁ : ⦃i j : E.I₀⦄ → E.I₁ i j ≃ F.I₁ (s₀ i) (s₀ j)
h₁ : ⦃i j : E.I₀⦄ → (k : E.I₁ i j) → E.Y k ≅ F.Y (s₁ k)
w₀ : ∀ (i : E.I₀), (h₀ i).hom ≫ F.f (s₀ i) = E.f i
w₁₁ : ∀ ⦃i j : E.I₀⦄ (k : E.I₁ i j), (h₁ k).hom ≫ F.p₁ (s₁ k) = E.p₁ k ≫ (h₀ i).hom
w₁₂ : ∀ ⦃i j : E.I₀⦄ (k : E.I₁ i j), (h₁ k).hom ≫ F.p₂ (s₁ k) = E.p₂ k ≫ (h₀ j).hom
⊢ ((let __Hom := (PreZeroHypercover.isoMk s₀ h₀ w₀).hom;
      { toHom := __Hom, s₁ := fun {i j} k ↦ s₁ k, h₁ := fun {i j} k ↦ (h₁ k).hom, w₁₁ := ⋯, w₁₂ := ⋯ }) ≫
      let __Hom := (PreZeroHypercover.isoMk s₀ h₀ w₀).inv;
      { toHom := __Hom, s₁ := fun {i j} k ↦ s₁.symm ((congrIndexOneOfEq ⋯ ⋯) k),
        h₁ := fun {i j} k ↦
          (congrIndexOneOfEqIso ⋯ ⋯ k).inv ≫ eqToHom ⋯ ≫ (h₁ (s₁.symm ((congrIndexOneOfEq ⋯ ⋯) k))).inv,
        w₁₁ := ⋯, w₁₂ := ⋯ }) =
    𝟙 E

Tactic:
refine PreOneHypercover.Hom.ext' (by ext; simp) (by intro i; simp)
      (fun i j k ↦ (E.congrIndexOneOfEq_equiv s₀ s₁ _).symm) ?_
    intro i j k
    simpa using E.isoMk_aux s₀ s₁ h₁ k

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

Goal state before:
pp: J : Type u'
inst✝³ : Category.{v', u'} J
C : Type u
inst✝² : Category.{v, u} C
D : Type u_1
inst✝¹ : Category.{v_1, u_1} D
K : C ⥤ D
X : C
inst✝ : IsConnected J
B : D
K✝ : J ⥤ CostructuredArrow K B
c✝ : Cone K✝
hc : IsLimit c✝
s : Cone (K✝ ⋙ proj K B)
m : s.pt ⟶ ((proj K B).mapCone c✝).pt
fac : ∀ (j : J), m ≫ ((proj K B).mapCone c✝).π.app j = s.π.app j
⊢ K.map m ≫ c✝.pt.hom = (CreatesConnected.raiseCone s).pt.hom

Tactic:
by simp [← fac]

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

Goal state before:
pp: case mpr
C : Type u
inst✝ : Category.{v, u} C
J : GrothendieckTopology C
X : C
S : J.Cover X
Y : C
f : Y ⟶ X
⊢ (↑S).arrows f → S.preOneHypercover.sieve₀.arrows f

Tactic:
· intro hf
    exact Sieve.ofArrows_mk _ _ ({ hf := hf, .. } : S.Arrow)

Goal state after: