∀ {C : Type u_2} [inst : CategoryTheory.Category.{u_1, u_2} C] {X Y : C} (e : X ≅ Y),
  CategoryTheory.CategoryStruct.comp (CategoryTheory.CategoryStruct.id X) e.hom =
    CategoryTheory.CategoryStruct.comp (CategoryTheory.CategoryStruct.id X) e.hom