∀ {C : Type u_1} [inst : CategoryTheory.Category.{v_1, u_1} C] [inst_1 : CategoryTheory.Abelian C]
  {S : CategoryTheory.ShortComplex (CochainComplex C ℤ)},
  S.ShortExact → QuasiIso (CochainComplex.mappingCone.descShortComplex S)