Theorem: CategoryTheory.GrothendieckTopology.diagramCompIso_hom_ι
File: Mathlib/CategoryTheory/Sites/CompatiblePlus.lean

Proof steps:
state_before: C : Type u
inst✝⁵ : Category.{v, u} C
J : GrothendieckTopology C
D : Type w₁
inst✝⁴ : Category.{max v u, w₁} D
E : Type w₂
inst✝³ : Category.{max v u, w₂} E
F : D ⥤ E
inst✝² : ∀ (α β : Type (max v u)) (fst snd : β → α), HasLimitsOfShape (WalkingMulticospan fst snd) D
inst✝¹ : ∀ (α β : Type (max v u)) (fst snd : β → α), HasLimitsOfShape (WalkingMulticospan fst snd) E
inst✝ : (X : C) → (W : J.Cover X) → (P : Cᵒᵖ ⥤ D) → PreservesLimit (W.index P).multicospan F
P : Cᵒᵖ ⥤ D
X : C
W : (J.Cover X)ᵒᵖ
i : (unop W).Arrow
⊢ (J.diagramCompIso F P X).hom.app W ≫ Multiequalizer.ι ((unop W).index (P ⋙ F)) i =
    F.map (Multiequalizer.ι ((unop W).index P) i)
state_after: C : Type u
inst✝⁵ : Category.{v, u} C
J : GrothendieckTopology C
D : Type w₁
inst✝⁴ : Category.{max v u, w₁} D
E : Type w₂
inst✝³ : Category.{max v u, w₂} E
F : D ⥤ E
inst✝² : ∀ (α β : Type (max v u)) (fst snd : β → α), HasLimitsOfShape (WalkingMulticospan fst snd) D
inst✝¹ : ∀ (α β : Type (max v u)) (fst snd : β → α), HasLimitsOfShape (WalkingMulticospan fst snd) E
inst✝ : (X : C) → (W : J.Cover X) → (P : Cᵒᵖ ⥤ D) → PreservesLimit (W.index P).multicospan F
P : Cᵒᵖ ⥤ D
X : C
W : (J.Cover X)ᵒᵖ
i : (unop W).Arrow
⊢ (NatIso.ofComponents
              (fun W =>
                (isLimitOfPreserves F (limit.isLimit ((unop W).index P).multicospan)).conePointUniqueUpToIso
                    (limit.isLimit (((unop W).index P).multicospan ⋙ F)) ≪≫
                  HasLimit.isoOfNatIso (Cover.multicospanComp F P (unop W)).symm)
              ⋯).hom.app
        W ≫
      Multiequalizer.ι ((unop W).index (P ⋙ F)) i =
    F.map (Multiequalizer.ι ((unop W).index P) i)
tactic: delta diagramCompIso
state_before: C : Type u
inst✝⁵ : Category.{v, u} C
J : GrothendieckTopology C
D : Type w₁
inst✝⁴ : Category.{max v u, w₁} D
E : Type w₂
inst✝³ : Category.{max v u, w₂} E
F : D ⥤ E
inst✝² : ∀ (α β : Type (max v u)) (fst snd : β → α), HasLimitsOfShape (WalkingMulticospan fst snd) D
inst✝¹ : ∀ (α β : Type (max v u)) (fst snd : β → α), HasLimitsOfShape (WalkingMulticospan fst snd) E
inst✝ : (X : C) → (W : J.Cover X) → (P : Cᵒᵖ ⥤ D) → PreservesLimit (W.index P).multicospan F
P : Cᵒᵖ ⥤ D
X : C
W : (J.Cover X)ᵒᵖ
i : (unop W).Arrow
⊢ (NatIso.ofComponents
              (fun W =>
                (isLimitOfPreserves F (limit.isLimit ((unop W).index P).multicospan)).conePointUniqueUpToIso
                    (limit.isLimit (((unop W).index P).multicospan ⋙ F)) ≪≫
                  HasLimit.isoOfNatIso (Cover.multicospanComp F P (unop W)).symm)
              ⋯).hom.app
        W ≫
      Multiequalizer.ι ((unop W).index (P ⋙ F)) i =
    F.map (Multiequalizer.ι ((unop W).index P) i)
state_after: C : Type u
inst✝⁵ : Category.{v, u} C
J : GrothendieckTopology C
D : Type w₁
inst✝⁴ : Category.{max v u, w₁} D
E : Type w₂
inst✝³ : Category.{max v u, w₂} E
F : D ⥤ E
inst✝² : ∀ (α β : Type (max v u)) (fst snd : β → α), HasLimitsOfShape (WalkingMulticospan fst snd) D
inst✝¹ : ∀ (α β : Type (max v u)) (fst snd : β → α), HasLimitsOfShape (WalkingMulticospan fst snd) E
inst✝ : (X : C) → (W : J.Cover X) → (P : Cᵒᵖ ⥤ D) → PreservesLimit (W.index P).multicospan F
P : Cᵒᵖ ⥤ D
X : C
W : (J.Cover X)ᵒᵖ
i : (unop W).Arrow
⊢ (((isLimitOfPreserves F (limit.isLimit ((unop W).index P).multicospan)).conePointUniqueUpToIso
            (limit.isLimit (((unop W).index P).multicospan ⋙ F))).hom ≫
        (HasLimit.isoOfNatIso (Cover.multicospanComp F P (unop W)).symm).hom) ≫
      Multiequalizer.ι ((unop W).index (P ⋙ F)) i =
    F.map (Multiequalizer.ι ((unop W).index P) i)
tactic: dsimp
state_before: C : Type u
inst✝⁵ : Category.{v, u} C
J : GrothendieckTopology C
D : Type w₁
inst✝⁴ : Category.{max v u, w₁} D
E : Type w₂
inst✝³ : Category.{max v u, w₂} E
F : D ⥤ E
inst✝² : ∀ (α β : Type (max v u)) (fst snd : β → α), HasLimitsOfShape (WalkingMulticospan fst snd) D
inst✝¹ : ∀ (α β : Type (max v u)) (fst snd : β → α), HasLimitsOfShape (WalkingMulticospan fst snd) E
inst✝ : (X : C) → (W : J.Cover X) → (P : Cᵒᵖ ⥤ D) → PreservesLimit (W.index P).multicospan F
P : Cᵒᵖ ⥤ D
X : C
W : (J.Cover X)ᵒᵖ
i : (unop W).Arrow
⊢ (((isLimitOfPreserves F (limit.isLimit ((unop W).index P).multicospan)).conePointUniqueUpToIso
            (limit.isLimit (((unop W).index P).multicospan ⋙ F))).hom ≫
        (HasLimit.isoOfNatIso (Cover.multicospanComp F P (unop W)).symm).hom) ≫
      Multiequalizer.ι ((unop W).index (P ⋙ F)) i =
    F.map (Multiequalizer.ι ((unop W).index P) i)
state_after: no goals
tactic: simp