∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] [inst_1 : CategoryTheory.Limits.HasZeroMorphisms C]
  {K : ChainComplex C ℕ} {L : CochainComplex C ℕ} (self : CochainComplex.ConnectData K L) {Z : C} (h : L.X 0 ⟶ Z),
  CategoryTheory.CategoryStruct.comp (K.d 1 0) (CategoryTheory.CategoryStruct.comp self.d₀ h) =
    CategoryTheory.CategoryStruct.comp 0 h