∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] [inst_1 : CategoryTheory.Preadditive C]
  (K : CochainComplex C ℤ) (n i m : ℤ) (hm : m = i + n), K.shiftFunctorObjXIso n i m hm = K.shiftFunctorObjXIso n i m hm