∀ {ι : Type u_3} {c : ComplexShape ι} {C : Type u_2} [inst : CategoryTheory.Category.{u_1, u_2} C]
  [inst_1 : CategoryTheory.Limits.HasZeroObject C] [inst_2 : CategoryTheory.Limits.HasZeroMorphisms C]
  (K : HomologicalComplex C c), CategoryTheory.Limits.IsZero (Opposite.op (HomologicalComplex.extend.X K none))