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

Goal state before:
pp: J : Type u₁
inst✝ : Category.{v₁, u₁} J
j₁ j₂ : J
hj₁ : ConnectedComponents.objectProperty (Quotient.mk'' j₂) j₁
h₁₂ : Zigzag j₁ j₂
l : List J
hl₁ : List.IsChain Zag (j₁ :: l)
hl₂ : (j₁ :: l).getLast ⋯ = j₂
f : (x : J) → Zigzag x j₂ → (ConnectedComponents.mk j₂).Component := fun x h ↦ { obj := x, property := ⋯ }
i : J
hi : i ∈ l
j k : J
⊢ Zag j k → Zigzag k j₂ → Zigzag j j₂

Tactic:
apply Relation.ReflTransGen.head

Goal state after:
Module: Mathlib.CategoryTheory.Category.Cat.Adjunction

Goal state before:
pp: X✝ : Type u
C✝ : Cat
C : Cat
X : Type u
G : C ⟶ typeToCat.obj X
cc : connectedComponents.obj C
⊢ (ConcreteCategory.hom
          ((TypeCat.homEquiv.trans
                ((ConnectedComponents.typeToCatHomEquiv (↑C) X).trans (Functor.equivCatHom (↑C) (Discrete X)))).symm
            G)).toFun
      cc =
    (ConcreteCategory.hom
          (connectedComponents.map G ≫
            { app := fun X ↦ ↾ConnectedComponents.liftFunctor (↑(typeToCat.obj X)) (𝟙 typeToCat.obj X).toFunctor,
                  naturality := ⋯ }.app
              X)).toFun
      cc

Tactic:
obtain ⟨_, _⟩ := Quotient.exists_rep cc

Goal state after:
X✝ : Type u
C✝ : Cat
C : Cat
X : Type u
G : C ⟶ typeToCat.obj X
cc : connectedComponents.obj C
w✝ : ↑C
h✝ : ⟦w✝⟧ = cc
⊢ (ConcreteCategory.hom
          ((TypeCat.homEquiv.trans
                ((ConnectedComponents.typeToCatHomEquiv (↑C) X).trans (Functor.equivCatHom (↑C) (Discrete X)))).symm
            G)).toFun
      cc =
    (ConcreteCategory.hom
          (connectedComponents.map G ≫
            { app := fun X ↦ ↾ConnectedComponents.liftFunctor (↑(typeToCat.obj X)) (𝟙 typeToCat.obj X).toFunctor,
                  naturality := ⋯ }.app
              X)).toFun
      cc
Module: Mathlib.CategoryTheory.Category.PartialFun

Goal state before:
pp: α β : PartialFun
e : α ≃ β
⊢ ↑(⇑e ∘ ⇑e.symm) = 𝟙 β

Tactic:
by
    simp only [Equiv.self_comp_symm, PFun.coe_id]
    rfl

Goal state after:
Module: Mathlib.Data.PFun

Goal state before:
pp: α : Type u_1
β : Type u_2
f : α → β
s : Set β
⊢ (↑f).core s = f ⁻¹' s

Tactic:
by
  ext x; simp [core_def]

Goal state after:
Module: Mathlib.CategoryTheory.Localization.Prod

Goal state before:
pp: C₁ : Type u₁
C₂ : Type u₂
D₁ : Type u₃
D₂ : Type u₄
inst✝⁶ : Category.{v₁, u₁} C₁
inst✝⁵ : Category.{v₂, u₂} C₂
inst✝⁴ : Category.{v₃, u₃} D₁
inst✝³ : Category.{v₄, u₄} D₂
L₁ : C₁ ⥤ D₁
W₁ : MorphismProperty C₁
L₂ : C₂ ⥤ D₂
W₂ : MorphismProperty C₂
E : Type u₅
inst✝² : Category.{v₅, u₅} E
F : C₁ × C₂ ⥤ E
hF : (W₁.prod W₂).IsInvertedBy F
inst✝¹ : W₁.ContainsIdentities
inst✝ : W₂.ContainsIdentities
⊢ W₁.Localization × W₂.Localization ⥤ E

Tactic:
refine uncurry.obj (Construction.lift (prodLift₁ F hF).flip ?_).flip
  intro _ _ f₂ hf₂
  have : ∀ (X₁ : W₁.Localization),
      IsIso (((Functor.flip (prodLift₁ F hF)).map f₂).app X₁) := fun X₁ => by
    obtain ⟨X₁, rfl⟩ := (Construction.objEquiv W₁).surjective X₁
    exact ((MorphismProperty.isomorphisms E).arrow_mk_iso_iff
      (((Functor.mapArrowFunctor _ _).mapIso
        (eqToIso (Functor.congr_obj (prod_fac₁ F hF) X₁))).app (Arrow.mk f₂))).2
          (hF _ ⟨MorphismProperty.id_mem _ _, hf₂⟩)
  apply NatIso.isIso_of_isIso_app

Goal state after:
Module: Mathlib.CategoryTheory.Enriched.FunctorCategory

Goal state before:
pp: V : Type u₁
inst✝⁸ : Category.{v₁, u₁} V
inst✝⁷ : MonoidalCategory V
C : Type u₂
inst✝⁶ : Category.{v₂, u₂} C
J : Type u₃
inst✝⁵ : Category.{v₃, u₃} J
K : Type u₄
inst✝⁴ : Category.{v₄, u₄} K
inst✝³ : EnrichedOrdinaryCategory V C
F₁ F₂ F₃ F₄ : J ⥤ C
inst✝² : HasEnrichedHom V F₁ F₂
inst✝¹ : HasEnrichedHom V F₂ F₃
inst✝ : HasEnrichedHom V F₁ F₃
i j : J
f : i ⟶ j
this :
  end_.π (diagram V F₂ F₃) i ≫
      (ρ_ (F₂.obj i ⟶[V] F₃.obj i)).inv ≫
        (F₂.obj i ⟶[V] F₃.obj i) ◁ (eHomEquiv V) (F₃.map f) ≫ eComp V (F₂.obj i) (F₃.obj i) (F₃.obj j) =
    end_.π (diagram V F₂ F₃) j ≫
      (λ_ (F₂.obj j ⟶[V] F₃.obj j)).inv ≫
        ((eHomEquiv V) (F₂.map f) ▷ F₂.obj j ⟶[V] F₃.obj j) ≫ eComp V (F₂.obj i) (F₂.obj j) (F₃.obj j)
| end_.π (diagram V F₁ F₂) i ▷ enrichedHom V F₂ F₃ ≫
    (F₁.obj i ⟶[V] F₂.obj i) ◁ end_.π (diagram V F₂ F₃) i ≫
      (F₁.obj i ⟶[V] F₂.obj i) ◁ (ρ_ (F₂.obj i ⟶[V] F₃.obj i)).inv ≫
        (F₁.obj i ⟶[V] F₂.obj i) ◁ (F₂.obj i ⟶[V] F₃.obj i) ◁ (eHomEquiv V) (F₃.map f) ≫
          (F₁.obj i ⟶[V] F₂.obj i) ◁ eComp V (F₂.obj i) (F₃.obj i) (F₃.obj j) ≫ eComp V (F₁.obj i) (F₂.obj i) (F₃.obj j)

Tactic:
← e_assoc,

Goal state after:
V : Type u₁
inst✝⁸ : Category.{v₁, u₁} V
inst✝⁷ : MonoidalCategory V
C : Type u₂
inst✝⁶ : Category.{v₂, u₂} C
J : Type u₃
inst✝⁵ : Category.{v₃, u₃} J
K : Type u₄
inst✝⁴ : Category.{v₄, u₄} K
inst✝³ : EnrichedOrdinaryCategory V C
F₁ F₂ F₃ F₄ : J ⥤ C
inst✝² : HasEnrichedHom V F₁ F₂
inst✝¹ : HasEnrichedHom V F₂ F₃
inst✝ : HasEnrichedHom V F₁ F₃
i j : J
f : i ⟶ j
this :
  end_.π (diagram V F₂ F₃) i ≫
      (ρ_ (F₂.obj i ⟶[V] F₃.obj i)).inv ≫
        (F₂.obj i ⟶[V] F₃.obj i) ◁ (eHomEquiv V) (F₃.map f) ≫ eComp V (F₂.obj i) (F₃.obj i) (F₃.obj j) =
    end_.π (diagram V F₂ F₃) j ≫
      (λ_ (F₂.obj j ⟶[V] F₃.obj j)).inv ≫
        ((eHomEquiv V) (F₂.map f) ▷ F₂.obj j ⟶[V] F₃.obj j) ≫ eComp V (F₂.obj i) (F₂.obj j) (F₃.obj j)
| end_.π (diagram V F₁ F₂) i ▷ enrichedHom V F₂ F₃ ≫
    (F₁.obj i ⟶[V] F₂.obj i) ◁ end_.π (diagram V F₂ F₃) i ≫
      (F₁.obj i ⟶[V] F₂.obj i) ◁ (ρ_ (F₂.obj i ⟶[V] F₃.obj i)).inv ≫
        (F₁.obj i ⟶[V] F₂.obj i) ◁ (F₂.obj i ⟶[V] F₃.obj i) ◁ (eHomEquiv V) (F₃.map f) ≫
          (α_ (F₁.obj i ⟶[V] F₂.obj i) (F₂.obj i ⟶[V] F₃.obj i) (F₃.obj i ⟶[V] F₃.obj j)).inv ≫
            (eComp V (F₁.obj i) (F₂.obj i) (F₃.obj i) ▷ F₃.obj i ⟶[V] F₃.obj j) ≫
              eComp V (F₁.obj i) (F₃.obj i) (F₃.obj j)
Module: Mathlib.CategoryTheory.EquivalenceRelation

Goal state before:
pp: X✝ : Type w
φ✝ : X✝ → X✝ → Prop
X : Type w
φ : X → X → Prop
hφ : IsTrans X φ
x✝ : (Types.pullbackCone (p₂OfRel φ) (p₁OfRel φ)).pt
x₁ snd✝ : X
h : Function.uncurry φ (x₁, snd✝)
fst✝ x₂' : X
h' : Function.uncurry φ (fst✝, x₂')
h₁₂ : snd✝ = fst✝
⊢ ROfRel φ

Tactic:
rw [← h₁₂] at h'

Goal state after:
X✝ : Type w
φ✝ : X✝ → X✝ → Prop
X : Type w
φ : X → X → Prop
hφ : IsTrans X φ
x✝ : (Types.pullbackCone (p₂OfRel φ) (p₁OfRel φ)).pt
x₁ snd✝ : X
h : Function.uncurry φ (x₁, snd✝)
fst✝ x₂' : X
h' : Function.uncurry φ (snd✝, x₂')
h₁₂ : snd✝ = fst✝
⊢ ROfRel φ
Module: Mathlib.CategoryTheory.FiberedCategory.Cocartesian

Goal state before:
pp: 𝒮 : Type u₁
𝒳 : Type u₂
inst✝⁴ : Category.{v₁, u₁} 𝒮
inst✝³ : Category.{v₂, u₂} 𝒳
p : 𝒳 ⥤ 𝒮
R S T : 𝒮
a b c : 𝒳
f : R ⟶ S
g : S ⟶ T
φ : a ⟶ b
ψ : b ⟶ c
inst✝² : p.IsStronglyCocartesian f φ
inst✝¹ : p.IsStronglyCocartesian (f ≫ g) (φ ≫ ψ)
inst✝ : p.IsHomLift g ψ
⊢ ∀ {b' : 𝒳} (g_1 : T ⟶ p.obj b') (φ' : b ⟶ b') [p.IsHomLift (g ≫ g_1) φ'], ∃! χ, p.IsHomLift g_1 χ ∧ ψ ≫ χ = φ'

Tactic:
intro c' h τ hτ
    /- We get a morphism `π : c ⟶ c'` such that `(φ ≫ ψ) ≫ π = φ ≫ τ` from the universal property
    of `φ ≫ ψ`. This will be the morphism induced by `φ`. -/
    use map p (f ≫ g) (φ ≫ ψ) (f' := f ≫ g ≫ h) (assoc f g h).symm (φ ≫ τ)
    refine ⟨⟨inferInstance, ?_⟩, ?_⟩
    /- The fact that `ψ ≫ π = τ` follows from `φ ≫ ψ ≫ π = φ ≫ τ` and the universal property of
    `φ`. -/
    · apply IsStronglyCocartesian.ext p f φ (g ≫ h) <| by simp only [← assoc, fac]
    -- Finally, uniqueness of `π` comes from the universal property of `φ ≫ ψ`.
    · intro π' ⟨hπ'₁, hπ'₂⟩
      apply map_uniq
      simp [hπ'₂.symm]

Goal state after:
Module: Mathlib.CategoryTheory.Functor.Derived.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
L₂ : C₂ ⥤ D₂
W₁ : MorphismProperty C₁
W₂ : MorphismProperty C₂
inst✝³ : L₁.IsLocalization W₁
inst✝² : L₂.IsLocalization W₂
G' : D₁ ⥤ D₂
F' : D₂ ⥤ D₁
α : L₁ ⋙ G' ⟶ G ⋙ L₂
β : F ⋙ L₁ ⟶ L₂ ⋙ F'
inst✝¹ : G'.IsLeftDerivedFunctor α W₁
inst✝ : F'.IsRightDerivedFunctor β W₂
η : 𝟭 D₁ ⟶ G' ⋙ F'
ε : F' ⋙ G' ⟶ 𝟭 D₂
hη : ∀ (X₁ : C₁), η.app (L₁.obj X₁) ≫ F'.map (α.app X₁) = L₁.map (adj.unit.app X₁) ≫ β.app (G.obj X₁)
hε : ∀ (X₂ : C₂), G'.map (β.app X₂) ≫ ε.app (L₂.obj X₂) = α.app (F.obj X₂) ≫ L₂.map (adj.counit.app X₂)
X₁ : C₁
eq₁ : G'.map (F'.map (α.app X₁)) ≫ ε.app (L₂.obj (G.obj X₁)) = ε.app (G'.obj (L₁.obj X₁)) ≫ α.app X₁
eq₃ : G'.map (L₁.map (adj.unit.app X₁)) ≫ α.app (F.obj (G.obj X₁)) = α.app X₁ ≫ L₂.map (G.map (adj.unit.app X₁))
eq₂ :
  G'.map (η.app (L₁.obj X₁)) ≫ G'.map (F'.map (α.app X₁)) =
    G'.map (L₁.map (adj.unit.app X₁)) ≫ G'.map (β.app (G.obj X₁))
⊢ (𝟙 (G'.obj (L₁.obj X₁)) ≫
        G'.map (η.app (L₁.obj X₁)) ≫
          𝟙 (G'.obj (F'.obj (G'.obj (L₁.obj X₁)))) ≫ ε.app (G'.obj (L₁.obj X₁)) ≫ 𝟙 (G'.obj (L₁.obj X₁))) ≫
      α.app X₁ =
    𝟙 (G'.obj (L₁.obj X₁)) ≫ α.app X₁

Tactic:
rw [Category.assoc, Category.assoc, Category.assoc, Category.comp_id,
      Category.id_comp, Category.id_comp, Category.id_comp, ← eq₁, reassoc_of% eq₂,
      hε (G.obj X₁), reassoc_of% eq₃, ← L₂.map_comp, adj.left_triangle_components,
      Functor.map_id, Category.comp_id]

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

Goal state before:
pp: J : Type
inst✝ : SmallCategory J
K : J ⥤ FintypeCat
j : J
⊢ Finite ((K ⋙ FintypeCat.incl).obj j)

Tactic:
simp only [comp_obj, FintypeCat.incl_obj]
  infer_instance

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

Goal state before:
pp: C : Type u₁
inst✝² : Category.{u₂, u₁} C
F : C ⥤ FintypeCat
inst✝¹ : PreGaloisCategory C
inst✝ : FiberFunctor F
X Y : C
f g : X ⟶ Y
h : F.map f = F.map g
this✝ : IsIso (equalizer.ι (F.map f) (F.map g))
this : IsIso (F.map (equalizer.ι f g))
⊢ f = g

Tactic:
have : IsIso (equalizer.ι f g) := isIso_of_reflects_iso _ F

Goal state after:
C : Type u₁
inst✝² : Category.{u₂, u₁} C
F : C ⥤ FintypeCat
inst✝¹ : PreGaloisCategory C
inst✝ : FiberFunctor F
X Y : C
f g : X ⟶ Y
h : F.map f = F.map g
this✝¹ : IsIso (equalizer.ι (F.map f) (F.map g))
this✝ : IsIso (F.map (equalizer.ι f g))
this : IsIso (equalizer.ι f g)
⊢ f = g
Module: Mathlib.CategoryTheory.Galois.Basic

Goal state before:
pp: C : Type u₁
inst✝³ : Category.{u₂, u₁} C
F : C ⥤ FintypeCat
inst✝² : PreGaloisCategory C
inst✝¹ : FiberFunctor F
X Y : C
f : X ⟶ Y
inst✝ : Mono f
h : Nat.card (F.obj X).obj = Nat.card (F.obj Y).obj
⊢ Function.Bijective ⇑(ConcreteCategory.hom (F.map f))

Tactic:
apply (Fintype.bijective_iff_injective_and_card (F.map f)).mpr

Goal state after:
C : Type u₁
inst✝³ : Category.{u₂, u₁} C
F : C ⥤ FintypeCat
inst✝² : PreGaloisCategory C
inst✝¹ : FiberFunctor F
X Y : C
f : X ⟶ Y
inst✝ : Mono f
h : Nat.card (F.obj X).obj = Nat.card (F.obj Y).obj
⊢ Function.Injective ⇑(ConcreteCategory.hom (F.map f)) ∧
    Fintype.card ((fun X ↦ X.obj) (F.obj X)) = Fintype.card ((fun X ↦ X.obj) (F.obj Y))
Module: Mathlib.CategoryTheory.Galois.Basic

Goal state before:
pp: C : Type u₁
inst✝³ : Category.{u₂, u₁} C
F : C ⥤ FintypeCat
inst✝² : PreGaloisCategory C
inst✝¹ : FiberFunctor F
X Y : C
f : X ⟶ Y
inst✝ : Mono f
h : Nat.card (F.obj X).obj = Nat.card (F.obj Y).obj
this : IsIso (F.map f)
⊢ IsIso f

Tactic:
exact isIso_of_reflects_iso f F

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

Goal state before:
pp: C : Type u₁
inst✝³ : Category.{u₂, u₁} C
F : C ⥤ FintypeCat
inst✝² : PreGaloisCategory C
inst✝¹ : FiberFunctor F
X Y : C
f : X ⟶ Y
inst✝ : Mono f
h : ¬IsIso f
hlt : ¬Nat.card (F.obj X).obj < Nat.card (F.obj Y).obj
⊢ IsIso f

Tactic:
apply isIso_of_mono_of_eq_card_fiber F f

Goal state after:
C : Type u₁
inst✝³ : Category.{u₂, u₁} C
F : C ⥤ FintypeCat
inst✝² : PreGaloisCategory C
inst✝¹ : FiberFunctor F
X Y : C
f : X ⟶ Y
inst✝ : Mono f
h : ¬IsIso f
hlt : ¬Nat.card (F.obj X).obj < Nat.card (F.obj Y).obj
⊢ Nat.card (F.obj X).obj = Nat.card (F.obj Y).obj
Module: Mathlib.CategoryTheory.Galois.GaloisObjects

Goal state before:
pp: case e₁
C : Type u₁
inst✝³ : Category.{u₂, u₁} C
inst✝² : GaloisCategory C
F : C ⥤ FintypeCat
inst✝¹ : FiberFunctor F
X : C
inst✝ : IsConnected X
J : SingleObj (Aut X) ⥤ C := ⋯
e : (F ⋙ FintypeCat.incl).obj (colimit J) ≅
  MulAction.orbitRel.Quotient (Aut X) ((J ⋙ F ⋙ FintypeCat.incl).obj (SingleObj.star (Aut X))) := ⋯
⊢ IsTerminal (colimit (SingleObj.functor (Aut.toEnd X))) ≃ ?β

Tactic:
apply (IsTerminal.isTerminalIffObj (F ⋙ FintypeCat.incl) _).trans
      (isLimitEmptyConeEquiv _ (asEmptyCone _) (asEmptyCone _) e)

Goal state after:
Module: Mathlib.CategoryTheory.Galois.GaloisObjects

Goal state before:
pp: C : Type u₁
inst✝³ : Category.{u₂, u₁} C
inst✝² : GaloisCategory C
F : C ⥤ FintypeCat
inst✝¹ : FiberFunctor F
X : C
inst✝ : IsConnected X
⊢ IsGalois X ↔ MulAction.IsPretransitive (Aut X) (F.obj X).obj

Tactic:
isGalois_iff_aux,

Goal state after:
C : Type u₁
inst✝³ : Category.{u₂, u₁} C
inst✝² : GaloisCategory C
F : C ⥤ FintypeCat
inst✝¹ : FiberFunctor F
X : C
inst✝ : IsConnected X
⊢ Nonempty (IsTerminal (colimit (SingleObj.functor (Aut.toEnd X)))) ↔ MulAction.IsPretransitive (Aut X) (F.obj X).obj
Module: Mathlib.CategoryTheory.Galois.Prorepresentability

Goal state before:
pp: C : Type u₁
inst✝² : Category.{u₂, u₁} C
inst✝¹ : GaloisCategory C
F : C ⥤ FintypeCat
inst✝ : FiberFunctor F
t : Aut F
⊢ asIso ((Aut.toEnd F) t) = t

Tactic:
exact Aut.ext rfl

Goal state after:
Module: Mathlib.CategoryTheory.Galois.Prorepresentability

Goal state before:
pp: C : Type u₁
inst✝³ : Category.{u₂, u₁} C
inst✝² : GaloisCategory C
F : C ⥤ FintypeCat
inst✝¹ : FiberFunctor F
f : Aut F
A : C
inst✝ : IsGalois A
a : (F.obj A).obj
⊢ (ConcreteCategory.hom
        (F.map
          ((AutGalois.π F { obj := A, pt := a, isGalois := ⋯ }) (MulOpposite.unop ((autMulEquivAutGalois F) f))).hom))
      a =
    (ConcreteCategory.hom (f.hom.app A)) a

Tactic:
dsimp [autMulEquivAutGalois, endMulEquivAutGalois]

Goal state after:
C : Type u₁
inst✝³ : Category.{u₂, u₁} C
inst✝² : GaloisCategory C
F : C ⥤ FintypeCat
inst✝¹ : FiberFunctor F
f : Aut F
A : C
inst✝ : IsGalois A
a : (F.obj A).obj
⊢ (ConcreteCategory.hom
        (F.map
          ((AutGalois.π F { obj := A, pt := a, isGalois := ⋯ })
              ((endEquivAutGalois F) ↑((Aut.unitsEndEquivAut F).symm f))).hom))
      a =
    (ConcreteCategory.hom (f.hom.app A)) a
Module: Mathlib.CategoryTheory.Galois.EssSurj

Goal state before:
pp: C : Type u₁
inst✝⁶ : Category.{u₂, u₁} C
F : C ⥤ FintypeCat
inst✝⁵ : GaloisCategory C
inst✝⁴ : FiberFunctor F
G : Type u_1
inst✝³ : Group G
inst✝² : TopologicalSpace G
inst✝¹ : IsTopologicalGroup G
inst✝ : CompactSpace G
V U : OpenSubgroup (Aut F)
h : (↑U).Normal
A : C
u : (functorToAction F).obj A ≅ ofMulAction (Aut F) (FintypeCat.of (Aut F ⧸ ↑U))
hUinV : U ≤ V
s : Cocone (quotientDiag V h u ⋙ functorToAction F)
f : (coconeQuotientDiag h u hUinV).pt ⟶ s.pt
hf : ∀ (j : SingleObj (↥↑V ⧸ (↑U).subgroupOf ↑V)), (coconeQuotientDiag h u hUinV).ι.app j ≫ f = s.ι.app j
⊢ f = coconeQuotientDiagDesc h u hUinV s

Tactic:
apply Action.hom_ext
    ext (x : Aut F ⧸ V.toSubgroup)
    induction x using Quotient.inductionOn with | _ σ
    simp [← hf (SingleObj.star _), ← ConcreteCategory.comp_apply]

Goal state after:
Module: Mathlib.CategoryTheory.Groupoid.Subgroupoid

Goal state before:
pp: C : Type u
inst✝¹ : Groupoid C
S : Subgroupoid C
D : Type u_1
inst✝ : Groupoid D
φ : C ⥤ D
hφ : Function.Injective φ.obj
hφ' : im φ hφ = ⊤
Sn : S.IsNormal
d : D
⊢ 𝟙 d ∈ (map φ hφ S).arrows d d

Tactic:
obtain ⟨c, rfl⟩ := obj_surjective_of_im_eq_top φ hφ hφ' d
      change Map.Arrows φ hφ S _ _ (𝟙 _); rw [← Functor.map_id]
      constructor; exact Sn.wide c

Goal state after:
Module: Mathlib.CategoryTheory.Groupoid.Subgroupoid

Goal state before:
pp: C : Type u
inst✝ : Groupoid C
S : Subgroupoid C
⊢ ∀ {c d : C} {p : c ⟶ d}, p ∈ {f | c = d ∧ f ∈ S.arrows c d} → Groupoid.inv p ∈ {f | d = c ∧ f ∈ S.arrows d c}

Tactic:
rintro _ _ _ ⟨rfl, h⟩

Goal state after:
C : Type u
inst✝ : Groupoid C
S : Subgroupoid C
c✝ : C
p✝ : c✝ ⟶ c✝
h : p✝ ∈ S.arrows c✝ c✝
⊢ Groupoid.inv p✝ ∈ {f | c✝ = c✝ ∧ f ∈ S.arrows c✝ c✝}
Module: Mathlib.CategoryTheory.Limits.FormalCoproducts.ExtraDegeneracy

Goal state before:
pp: C : Type u
inst✝¹ : Category.{v, u} C
inst✝ : HasFiniteProducts C
U : FormalCoproduct C
T : C
hT : IsTerminal T
n : SimplexCategoryᵒᵖ
i : ToType (Opposite.unop n)
⊢ (U.cechIsoCechNerveApp hT n).inv ≫ U.powerπ i = WidePullback.π (fun x ↦ (isTerminalIncl T hT).from U) i

Tactic:
rw [← U.cechIsoCechNerveApp_hom_π hT, Iso.inv_hom_id_assoc]

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

Goal state before:
pp: C : Type u₁
inst✝³ : Category.{v₁, u₁} C
D : Type u₂
inst✝² : Category.{v₂, u₂} D
E : Type u₃
inst✝¹ : Category.{v₃, u₃} E
E' : Type u₄
inst✝ : Category.{v₄, u₄} E'
F : C ⥤ E
G : D ⥤ E
α : Prod.fst C D ⋙ F ⟶ Prod.snd C D ⋙ G
x✝ y✝ : C
f : x✝ ⟶ y✝
d : D
⊢ homInduction (fun x x_1 f ↦ F.map f) (fun x x_1 g ↦ G.map g) (fun c d ↦ α.app (c, d))
      ((inclLeft C D).map f ≫ edge y✝ d) =
    homInduction (fun x x_1 f ↦ F.map f) (fun x x_1 g ↦ G.map g) (fun c d ↦ α.app (c, d)) ((inclLeft C D).map f) ≫
      homInduction (fun x x_1 f ↦ F.map f) (fun x x_1 g ↦ G.map g) (fun c d ↦ α.app (c, d)) (edge y✝ d)

Tactic:
simpa using! (α.naturality <| (Prod.sectL _ d).map f).symm

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

Goal state before:
pp: C : Type u
inst✝ : Category.{v, u} C
X₁ X₂ X₃ S : C
f₁ : X₁ ⟶ S
f₂ : X₂ ⟶ S
f₃ : X₃ ⟶ S
h₁₂ : ChosenPullback f₁ f₂
h₂₃ : ChosenPullback f₂ f₃
h₁₃ : ChosenPullback f₁ f₃
h : ChosenPullback₃ h₁₂ h₂₃ h₁₃
⊢ h.p₁₃ ≫ h₁₃.p = h.p

Tactic:
← h₁₃.hp₁,

Goal state after:
C : Type u
inst✝ : Category.{v, u} C
X₁ X₂ X₃ S : C
f₁ : X₁ ⟶ S
f₂ : X₂ ⟶ S
f₃ : X₃ ⟶ S
h₁₂ : ChosenPullback f₁ f₂
h₂₃ : ChosenPullback f₂ f₃
h₁₃ : ChosenPullback f₁ f₃
h : ChosenPullback₃ h₁₂ h₂₃ h₁₃
⊢ h.p₁₃ ≫ h₁₃.p₁ ≫ f₁ = h.p
Module: Mathlib.CategoryTheory.Limits.Types.End

Goal state before:
pp: J : Type u
inst✝ : Category.{v, u} J
F : Jᵒᵖ ⥤ J ⥤ Type (max w u)
s : Cocone (multispanIndexCoend F).multispan
x✝¹ x✝ : (j : J) × (F.obj (op j)).obj j
h : coendRel F x✝¹ x✝
⊢ (hom (Multicofork.π s x✝¹.fst)) x✝¹.snd = (hom (Multicofork.π s x✝.fst)) x✝.snd

Tactic:
cases h with | mk f x => exact ConcreteCategory.congr_hom (Cowedge.condition s f) _

Goal state after:
Module: Mathlib.CategoryTheory.Limits.Types.End

Goal state before:
pp: J : Type u
inst✝ : Category.{v, u} J
F G : Jᵒᵖ ⥤ J ⥤ Type (max w u)
f : F ⟶ G
x : chosenCoend F
j✝ j'✝ : J
g : j✝ ⟶ j'✝
y : (F.obj (op j'✝)).obj j✝
⊢ ∃ f_1 y_1,
    (hom ((G.map f_1.op).app j✝)) y_1 = (hom ((f.app (op j✝)).app j✝)) ((Hom.hom ((F.map g.op).app j✝)) y) ∧
      (hom ((G.obj (op j'✝)).map f_1)) y_1 = (hom ((f.app (op j'✝)).app j'✝)) ((Hom.hom ((F.obj (op j'✝)).map g)) y)

Tactic:
refine ⟨g, (f.app _).app _ y, ?_, ?_⟩

Goal state after:
case refine_1
J : Type u
inst✝ : Category.{v, u} J
F G : Jᵒᵖ ⥤ J ⥤ Type (max w u)
f : F ⟶ G
x : chosenCoend F
j✝ j'✝ : J
g : j✝ ⟶ j'✝
y : (F.obj (op j'✝)).obj j✝
⊢ (hom ((G.map g.op).app j✝)) ((hom ((f.app (op j'✝)).app j✝)) y) =
    (hom ((f.app (op j✝)).app j✝)) ((Hom.hom ((F.map g.op).app j✝)) y)

case refine_2
J : Type u
inst✝ : Category.{v, u} J
F G : Jᵒᵖ ⥤ J ⥤ Type (max w u)
f : F ⟶ G
x : chosenCoend F
j✝ j'✝ : J
g : j✝ ⟶ j'✝
y : (F.obj (op j'✝)).obj j✝
⊢ (hom ((G.obj (op j'✝)).map g)) ((hom ((f.app (op j'✝)).app j✝)) y) =
    (hom ((f.app (op j'✝)).app j'✝)) ((Hom.hom ((F.obj (op j'✝)).map g)) y)
Module: Mathlib.CategoryTheory.Localization.DerivabilityStructure.OfFunctorialResolutions

Goal state before:
pp: C₁ : Type u_1
C₂ : Type u_2
inst✝² : Category.{v_1, u_1} C₁
inst✝¹ : Category.{v_2, u_2} C₂
W₁ : MorphismProperty C₁
W₂ : MorphismProperty C₂
Φ : LocalizerMorphism W₁ W₂
ρ : C₂ ⥤ C₁
i : 𝟭 C₂ ⟶ ρ ⋙ Φ.functor
hi : ∀ (X₂ : C₂), W₂ (i.app X₂)
hW₁ : W₁ = W₂.inverseImage Φ.functor
inst✝ : W₂.HasTwoOutOfThreeProperty
⊢ W₂ ≤ W₁.inverseImage ρ

Tactic:
hW₁

Goal state after:
C₁ : Type u_1
C₂ : Type u_2
inst✝² : Category.{v_1, u_1} C₁
inst✝¹ : Category.{v_2, u_2} C₂
W₁ : MorphismProperty C₁
W₂ : MorphismProperty C₂
Φ : LocalizerMorphism W₁ W₂
ρ : C₂ ⥤ C₁
i : 𝟭 C₂ ⟶ ρ ⋙ Φ.functor
hi : ∀ (X₂ : C₂), W₂ (i.app X₂)
hW₁ : W₁ = W₂.inverseImage Φ.functor
inst✝ : W₂.HasTwoOutOfThreeProperty
⊢ W₂ ≤ (W₂.inverseImage Φ.functor).inverseImage ρ
Module: Mathlib.CategoryTheory.Localization.DerivabilityStructure.OfFunctorialResolutions

Goal state before:
pp: C₁ : Type u_1
C₂ : Type u_2
inst✝⁵ : Category.{v_1, u_1} C₁
inst✝⁴ : Category.{v_2, u_2} C₂
W₁ : MorphismProperty C₁
W₂ : MorphismProperty C₂
Φ : LocalizerMorphism W₁ W₂
ρ : C₂ ⥤ C₁
i : 𝟭 C₂ ⟶ ρ ⋙ Φ.functor
hi : ∀ (X₂ : C₂), W₂ (i.app X₂)
hW₁ : W₁ = W₂.inverseImage Φ.functor
inst✝³ : Φ.functor.Full
inst✝² : Φ.functor.Faithful
inst✝¹ : W₂.HasTwoOutOfThreeProperty
inst✝ : W₂.IsMultiplicative
X₂ : C₂
⊢ W₁.IsMultiplicative

Tactic:
hW₁

Goal state after:
C₁ : Type u_1
C₂ : Type u_2
inst✝⁵ : Category.{v_1, u_1} C₁
inst✝⁴ : Category.{v_2, u_2} C₂
W₁ : MorphismProperty C₁
W₂ : MorphismProperty C₂
Φ : LocalizerMorphism W₁ W₂
ρ : C₂ ⥤ C₁
i : 𝟭 C₂ ⟶ ρ ⋙ Φ.functor
hi : ∀ (X₂ : C₂), W₂ (i.app X₂)
hW₁ : W₁ = W₂.inverseImage Φ.functor
inst✝³ : Φ.functor.Full
inst✝² : Φ.functor.Faithful
inst✝¹ : W₂.HasTwoOutOfThreeProperty
inst✝ : W₂.IsMultiplicative
X₂ : C₂
⊢ (W₂.inverseImage Φ.functor).IsMultiplicative
Module: Mathlib.CategoryTheory.Localization.DerivabilityStructure.OfFunctorialResolutions

Goal state before:
pp: C₁ : Type u_1
C₂ : Type u_2
inst✝⁵ : Category.{v_1, u_1} C₁
inst✝⁴ : Category.{v_2, u_2} C₂
W₁ : MorphismProperty C₁
W₂ : MorphismProperty C₂
Φ : LocalizerMorphism W₁ W₂
ρ : C₂ ⥤ C₁
i : 𝟭 C₂ ⟶ ρ ⋙ Φ.functor
hi : ∀ (X₂ : C₂), W₂ (i.app X₂)
hW₁ : W₁ = W₂.inverseImage Φ.functor
inst✝³ : Φ.functor.Full
inst✝² : Φ.functor.Faithful
inst✝¹ : W₂.HasTwoOutOfThreeProperty
inst✝ : W₂.IsMultiplicative
⊢ W₁.IsMultiplicative

Tactic:
hW₁

Goal state after:
C₁ : Type u_1
C₂ : Type u_2
inst✝⁵ : Category.{v_1, u_1} C₁
inst✝⁴ : Category.{v_2, u_2} C₂
W₁ : MorphismProperty C₁
W₂ : MorphismProperty C₂
Φ : LocalizerMorphism W₁ W₂
ρ : C₂ ⥤ C₁
i : 𝟭 C₂ ⟶ ρ ⋙ Φ.functor
hi : ∀ (X₂ : C₂), W₂ (i.app X₂)
hW₁ : W₁ = W₂.inverseImage Φ.functor
inst✝³ : Φ.functor.Full
inst✝² : Φ.functor.Faithful
inst✝¹ : W₂.HasTwoOutOfThreeProperty
inst✝ : W₂.IsMultiplicative
⊢ (W₂.inverseImage Φ.functor).IsMultiplicative
Module: Mathlib.CategoryTheory.Localization.LocallySmall

Goal state before:
pp: C : Type u₁
inst✝³ : Category.{v₁, u₁} C
W : MorphismProperty C
D : Type u₂
inst✝² : Category.{v₂, u₂} D
inst✝¹ : LocallySmall.{w, v₂, u₂} D
L : C ⥤ D
inst✝ : L.IsLocalization W
this✝² : LocallySmall.{w, v₂, u₁} (InducedCategory D L.obj)
L' : C ⥤ InducedCategory D L.obj :=
  { obj := fun X ↦ X, map := fun {X Y} f ↦ InducedCategory.homMk (L.map f), map_id := ⋯, map_comp := ⋯ }
this✝¹ : L.EssSurj
this✝ : (inducedFunctor L.obj).EssSurj
this : (inducedFunctor L.obj).IsEquivalence
e : InducedCategory D L.obj ≌ D := (inducedFunctor L.obj).asEquivalence
⊢ W.HasLocalization

Tactic:
let e' : (L' ⋙ e.functor) ⋙ e.inverse ≅ L' :=
    associator _ _ _ ≪≫ isoWhiskerLeft L' e.unitIso.symm ≪≫ L'.rightUnitor

Goal state after:
C : Type u₁
inst✝³ : Category.{v₁, u₁} C
W : MorphismProperty C
D : Type u₂
inst✝² : Category.{v₂, u₂} D
inst✝¹ : LocallySmall.{w, v₂, u₂} D
L : C ⥤ D
inst✝ : L.IsLocalization W
this✝² : LocallySmall.{w, v₂, u₁} (InducedCategory D L.obj)
L' : C ⥤ InducedCategory D L.obj :=
  { obj := fun X ↦ X, map := fun {X Y} f ↦ InducedCategory.homMk (L.map f), map_id := ⋯, map_comp := ⋯ }
this✝¹ : L.EssSurj
this✝ : (inducedFunctor L.obj).EssSurj
this : (inducedFunctor L.obj).IsEquivalence
e : InducedCategory D L.obj ≌ D := (inducedFunctor L.obj).asEquivalence
e' : (L' ⋙ e.functor) ⋙ e.inverse ≅ L' :=
  L'.associator e.functor e.inverse ≪≫ L'.isoWhiskerLeft e.unitIso.symm ≪≫ L'.rightUnitor
⊢ W.HasLocalization
Module: Mathlib.CategoryTheory.Limits.Shapes.Pullback.Categorical.Basic

Goal state before:
pp: A : Type u₁
B : Type u₂
C : Type u₃
inst✝³ : Category.{v₁, u₁} A
inst✝² : Category.{v₂, u₂} B
inst✝¹ : Category.{v₃, u₃} C
F : A ⥤ B
G : C ⥤ B
X : Type u₄
inst✝ : Category.{v₄, u₄} X
J K : X ⥤ F ⊡ G
α β : J ⟶ K
e₁ : whiskerRight α (π₁ F G) = whiskerRight β (π₁ F G)
e₂ : whiskerRight α (π₂ F G) = whiskerRight β (π₂ F G)
⊢ α = β

Tactic:
by
  ext x
  · exact congrArg (fun t ↦ t.app x) e₁
  · exact congrArg (fun t ↦ t.app x) e₂

Goal state after: