∀ {C : Type u_2} [inst : CategoryTheory.Category.{u_1, u_2} C] [inst_1 : CategoryTheory.Abelian C] (X : C)
  (I : CategoryTheory.InjectiveResolution X),
  CategoryTheory.CategoryStruct.comp I.ι (CategoryTheory.CategoryStruct.id I.cocomplex) =
    CategoryTheory.CategoryStruct.comp ((CochainComplex.single₀ C).map (CategoryTheory.CategoryStruct.id X)) I.ι