{M : Type u_1} →
  {N : Type u_2} →
    {P : Type u_3} →
      {φ : M → N} →
        {ψ : N → P} →
          {χ : M → P} →
            {motive : CompTriple φ ψ χ → Sort u} →
              ((comp_eq : ψ ∘ φ = χ) → motive ⋯) → (t : CompTriple φ ψ χ) → motive t