∀ {V : Type u_2} [inst : CategoryTheory.Category.{u_1, u_2} V] [inst_1 : CategoryTheory.Limits.HasZeroMorphisms V]
  (C : CochainComplex V ℕ) (i j k : ℕ),
  (ComplexShape.up ℕ).Rel i j →
    (ComplexShape.up ℕ).Rel j k → CategoryTheory.CategoryStruct.comp (C.d (i + 1) (j + 1)) (C.d (j + 1) (k + 1)) = 0