∀ {C : Type u₁} [inst : CategoryTheory.Category.{v₁, u₁} C] {D : Type u₂} [inst_1 : CategoryTheory.Category.{v₂, u₂} D]
  (e : C ≌ D) (X Y : C) (f : X ⟶ Y) {Z : C} (h : e.inverse.obj (e.functor.obj Y) ⟶ Z),
  CategoryTheory.CategoryStruct.comp (e.inverse.map (e.functor.map f)) h =
    CategoryTheory.CategoryStruct.comp (e.unitInv.app X)
      (CategoryTheory.CategoryStruct.comp f (CategoryTheory.CategoryStruct.comp (e.unit.app Y) h))