∀ {C : Type u_2} [inst : CategoryTheory.Category.{u_1, u_2} C] [inst_1 : CategoryTheory.Preadditive C]
  {S₁ S₂ S₃ : CategoryTheory.ShortComplex C} {φ₁ φ₂ : S₁ ⟶ S₂} (h : CategoryTheory.ShortComplex.Homotopy φ₁ φ₂)
  (ψ : S₃ ⟶ S₁), CategoryTheory.CategoryStruct.comp (CategoryTheory.CategoryStruct.comp ψ.τ₁ h.h₀) S₂.f = 0