∀ {C : Type u_2} [inst : CategoryTheory.Category.{u_1, u_2} C] [inst_1 : CategoryTheory.Limits.HasZeroObject C]
  [inst_2 : CategoryTheory.Limits.HasZeroMorphisms C] {X Y : C},
  CategoryTheory.CategoryStruct.comp 0 (CategoryTheory.CategoryStruct.comp 0 0) =
    CategoryTheory.CategoryStruct.comp 0 (CategoryTheory.CategoryStruct.id Y)