∀ {ι : Type u_1} {ι' : Type u_2} {c : ComplexShape ι} {c' : ComplexShape ι'} {C : Type u_3}
  [inst : CategoryTheory.Category.{v_1, u_3} C] [inst_1 : CategoryTheory.Limits.HasZeroMorphisms C]
  [inst_2 : CategoryTheory.Limits.HasZeroObject C] {K L : HomologicalComplex C c'} (φ : K ⟶ L) (e : c.Embedding c')
  [inst_3 : e.IsRelIff] {i : ι} {i' : ι'} (hi : e.f i = i'),
  CategoryTheory.CategoryStruct.comp ((HomologicalComplex.stupidTruncMap φ e).f i') (L.stupidTruncXIso e hi).hom =
    CategoryTheory.CategoryStruct.comp (K.stupidTruncXIso e hi).hom (φ.f i')