{C : Type u} →
  [inst : CategoryTheory.Category.{v, u} C] →
    [inst_1 : CategoryTheory.Preadditive C] →
      {F G : CochainComplex C ℤ} → {φ₁ φ₂ : F ⟶ G} → Homotopy φ₁ φ₂ → CochainComplex.HomComplex.Cochain F G (-1)