-- Mathlib/CategoryTheory/GradedObject/Trifunctor.lean
@[reassoc (attr := simp)]
lemma ι_mapBifunctorComp₁₂MapObjIso_hom (i₁ : I₁) (i₂ : I₂) (i₃ : I₃) (j : J)
    (h : r (i₁, i₂, i₃) = j) :
    ιMapTrifunctorMapObj (bifunctorComp₁₂ F₁₂ G) r X₁ X₂ X₃ i₁ i₂ i₃ j h ≫
      (mapBifunctorComp₁₂MapObjIso F₁₂ G ρ₁₂ X₁ X₂ X₃).hom j =
      ιMapBifunctor₁₂BifunctorMapObj F₁₂ G ρ₁₂ X₁ X₂ X₃ i₁ i₂ i₃ j h

Proof state:
C₁ : Type u_1
C₂ : Type u_2
C₃ : Type u_3
C₄ : Type u_4
C₁₂ : Type u_5
inst✝⁷ : Category.{u_14, u_1} C₁
inst✝⁶ : Category.{u_13, u_2} C₂
inst✝⁵ : Category.{u_12, u_3} C₃
inst✝⁴ : Category.{u_11, u_4} C₄
inst✝³ : Category.{u_15, u_5} C₁₂
F₁₂ : C₁ ⥤ C₂ ⥤ C₁₂
G : C₁₂ ⥤ C₃ ⥤ C₄
I₁ : Type u_7
I₂ : Type u_8
I₃ : Type u_9
J : Type u_10
r : I₁ × I₂ × I₃ → J
ρ₁₂ : BifunctorComp₁₂IndexData r
X₁ : GradedObject I₁ C₁
X₂ : GradedObject I₂ C₂
X₃ : GradedObject I₃ C₃
inst✝² : (((mapBifunctor F₁₂ I₁ I₂).obj X₁).obj X₂).HasMap ρ₁₂.p
inst✝¹ : (((mapBifunctor G ρ₁₂.I₁₂ I₃).obj (mapBifunctorMapObj F₁₂ ρ₁₂.p X₁ X₂)).obj X₃).HasMap ρ₁₂.q
H : HasGoodTrifunctor₁₂Obj F₁₂ G ρ₁₂ X₁ X₂ X₃
inst✝ : ((((mapTrifunctor (bifunctorComp₁₂ F₁₂ G) I₁ I₂ I₃).obj X₁).obj X₂).obj X₃).HasMap r
i₁ : I₁
i₂ : I₂
i₃ : I₃
j : J
h : r (i₁, i₂, i₃) = j
⊢ ιMapTrifunctorMapObj (bifunctorComp₁₂ F₁₂ G) r X₁ X₂ X₃ i₁ i₂ i₃ j h ≫
      (CofanMapObjFun.iso (isColimitCofan₃MapBifunctor₁₂BifunctorMapObj F₁₂ G ρ₁₂ X₁ X₂ X₃ j)).inv =
    ιMapBifunctor₁₂BifunctorMapObj F₁₂ G ρ₁₂ X₁ X₂ X₃ i₁ i₂ i₃ j h

Tactic:
apply CofanMapObjFun.ιMapObj_iso_inv

Result:
no goals

Proof state:
C₁ : Type u_1
C₂ : Type u_2
C₃ : Type u_3
C₄ : Type u_4
C₁₂ : Type u_5
inst✝⁷ : Category.{u_14, u_1} C₁
inst✝⁶ : Category.{u_13, u_2} C₂
inst✝⁵ : Category.{u_12, u_3} C₃
inst✝⁴ : Category.{u_11, u_4} C₄
inst✝³ : Category.{u_15, u_5} C₁₂
F₁₂ : C₁ ⥤ C₂ ⥤ C₁₂
G : C₁₂ ⥤ C₃ ⥤ C₄
I₁ : Type u_7
I₂ : Type u_8
I₃ : Type u_9
J : Type u_10
r : I₁ × I₂ × I₃ → J
ρ₁₂ : BifunctorComp₁₂IndexData r
X₁ : GradedObject I₁ C₁
X₂ : GradedObject I₂ C₂
X₃ : GradedObject I₃ C₃
inst✝² : (((mapBifunctor F₁₂ I₁ I₂).obj X₁).obj X₂).HasMap ρ₁₂.p
inst✝¹ : (((mapBifunctor G ρ₁₂.I₁₂ I₃).obj (mapBifunctorMapObj F₁₂ ρ₁₂.p X₁ X₂)).obj X₃).HasMap ρ₁₂.q
H : HasGoodTrifunctor₁₂Obj F₁₂ G ρ₁₂ X₁ X₂ X₃
inst✝ : ((((mapTrifunctor (bifunctorComp₁₂ F₁₂ G) I₁ I₂ I₃).obj X₁).obj X₂).obj X₃).HasMap r
i₁ : I₁
i₂ : I₂
i₃ : I₃
j : J
h : r (i₁, i₂, i₃) = j
⊢ ιMapTrifunctorMapObj (bifunctorComp₁₂ F₁₂ G) r X₁ X₂ X₃ i₁ i₂ i₃ j h ≫
      (mapBifunctorComp₁₂MapObjIso F₁₂ G ρ₁₂ X₁ X₂ X₃).hom j =
    ιMapBifunctor₁₂BifunctorMapObj F₁₂ G ρ₁₂ X₁ X₂ X₃ i₁ i₂ i₃ j h

Tactic:
dsimp [mapBifunctorComp₁₂MapObjIso]

Result:
C₁ : Type u_1
C₂ : Type u_2
C₃ : Type u_3
C₄ : Type u_4
C₁₂ : Type u_5
inst✝⁷ : Category.{u_14, u_1} C₁
inst✝⁶ : Category.{u_13, u_2} C₂
inst✝⁵ : Category.{u_12, u_3} C₃
inst✝⁴ : Category.{u_11, u_4} C₄
inst✝³ : Category.{u_15, u_5} C₁₂
F₁₂ : C₁ ⥤ C₂ ⥤ C₁₂
G : C₁₂ ⥤ C₃ ⥤ C₄
I₁ : Type u_7
I₂ : Type u_8
I₃ : Type u_9
J : Type u_10
r : I₁ × I₂ × I₃ → J
ρ₁₂ : BifunctorComp₁₂IndexData r
X₁ : GradedObject I₁ C₁
X₂ : GradedObject I₂ C₂
X₃ : GradedObject I₃ C₃
inst✝² : (((mapBifunctor F₁₂ I₁ I₂).obj X₁).obj X₂).HasMap ρ₁₂.p
inst✝¹ : (((mapBifunctor G ρ₁₂.I₁₂ I₃).obj (mapBifunctorMapObj F₁₂ ρ₁₂.p X₁ X₂)).obj X₃).HasMap ρ₁₂.q
H : HasGoodTrifunctor₁₂Obj F₁₂ G ρ₁₂ X₁ X₂ X₃
inst✝ : ((((mapTrifunctor (bifunctorComp₁₂ F₁₂ G) I₁ I₂ I₃).obj X₁).obj X₂).obj X₃).HasMap r
i₁ : I₁
i₂ : I₂
i₃ : I₃
j : J
h : r (i₁, i₂, i₃) = j
⊢ ιMapTrifunctorMapObj (bifunctorComp₁₂ F₁₂ G) r X₁ X₂ X₃ i₁ i₂ i₃ j h ≫
      (CofanMapObjFun.iso (isColimitCofan₃MapBifunctor₁₂BifunctorMapObj F₁₂ G ρ₁₂ X₁ X₂ X₃ j)).inv =
    ιMapBifunctor₁₂BifunctorMapObj F₁₂ G ρ₁₂ X₁ X₂ X₃ i₁ i₂ i₃ j h