{C : Type u_1} →
  [inst : CategoryTheory.Category.{v, u_1} C] →
    [inst_1 : CategoryTheory.Preadditive C] →
      (S : CategoryTheory.ShortComplex (CochainComplex C ℤ)) →
        (σ : (n : ℤ) → (S.map (HomologicalComplex.eval C (ComplexShape.up ℤ) n)).Splitting) →
          [inst_2 : CategoryTheory.Limits.HasBinaryBiproducts C] →
            CochainComplex.mappingCone (CochainComplex.homOfDegreewiseSplit S σ) ≅
              (CategoryTheory.shiftFunctor (CochainComplex C ℤ) 1).obj S.X₂