∀ {C : Type u_2} [inst : CategoryTheory.Category.{u_6, u_2} C] {D : Type u_4}
  [inst_1 : CategoryTheory.Category.{u_1, u_4} D] {E : Type u_5} [inst_2 : CategoryTheory.Category.{u_3, u_5} E]
  {X Y : CategoryTheory.Functor D (CategoryTheory.Functor C E)} (f : X ⟶ Y),
  CategoryTheory.CategoryStruct.comp
      (((CategoryTheory.flipFunctor D C E).comp (CategoryTheory.flipFunctor C D E)).map f)
      ((fun x =>
            CategoryTheory.NatIso.ofComponents
              (fun x_1 =>
                CategoryTheory.NatIso.ofComponents
                  (fun x_2 =>
                    CategoryTheory.Iso.refl
                      (((((CategoryTheory.flipFunctor D C E).comp (CategoryTheory.flipFunctor C D E)).obj x).obj
                            x_1).obj
                        x_2))
                  ⋯)
              ⋯)
          Y).hom =
    CategoryTheory.CategoryStruct.comp
      ((fun x =>
            CategoryTheory.NatIso.ofComponents
              (fun x_1 =>
                CategoryTheory.NatIso.ofComponents
                  (fun x_2 =>
                    CategoryTheory.Iso.refl
                      (((((CategoryTheory.flipFunctor D C E).comp (CategoryTheory.flipFunctor C D E)).obj x).obj
                            x_1).obj
                        x_2))
                  ⋯)
              ⋯)
          X).hom
      ((CategoryTheory.Functor.id (CategoryTheory.Functor D (CategoryTheory.Functor C E))).map f)