{C : Type u} →
  [inst : CategoryTheory.Category.{v, u} C] →
    [inst_1 : CategoryTheory.Preadditive C] →
      {K L : CochainComplex C ℤ} →
        {n : ℤ} → CochainComplex.HomComplex.Cochain K L n → CochainComplex.HomComplex.Cochain K L n → ℤ → Prop