{C : Type u_1} →
  [inst : CategoryTheory.Category.{v_1, u_1} C] →
    [inst_1 : CategoryTheory.Abelian C] →
      {S₁ S₂ S₃ : CategoryTheory.ShortComplex.SnakeInput C} → S₁.Hom S₂ → S₂.Hom S₃ → S₁.Hom S₃