∀ {C : Type u_4} [inst : CategoryTheory.Category.{u_3, u_4} C] {D : Type u_2}
  [inst_1 : CategoryTheory.Category.{u_1, u_2} D] (F : CategoryTheory.Functor C D) ⦃X Y : C⦄ (f : X ⟶ Y),
  CategoryTheory.CategoryStruct.comp (F.map f) (CategoryTheory.CategoryStruct.id (F.obj Y)) =
    CategoryTheory.CategoryStruct.comp (CategoryTheory.CategoryStruct.id (F.obj X)) (F.map f)