{C : Type u} →
  [inst : CategoryTheory.Category.{v, u} C] →
    [inst_1 : CategoryTheory.Limits.HasZeroObject C] →
      [inst_2 : CategoryTheory.Preadditive C] →
        {X : C} →
          (R : CategoryTheory.ProjectiveResolution X) → R.cochainComplex ⟶ (CochainComplex.singleFunctor C 0).obj X