∀ {C : Type u_1} [inst : CategoryTheory.Category.{v_1, u_1} C] [inst_1 : CategoryTheory.Preadditive C]
  {S : CategoryTheory.ShortComplex C} [CategoryTheory.Balanced C],
  S.Exact → ∀ [CategoryTheory.Mono S.f] [inst_4 : S.HasLeftHomology], CategoryTheory.IsIso S.toCycles