{σ : Type u_2} →
  {τ : Type u_1} →
    (motive : ((τ →₀ ℕ) × (τ →₀ ℕ)) × (σ →₀ ℕ) × (σ →₀ ℕ) → Sort u_3) →
      (x : ((τ →₀ ℕ) × (τ →₀ ℕ)) × (σ →₀ ℕ) × (σ →₀ ℕ)) →
        ((fst : (τ →₀ ℕ) × (τ →₀ ℕ)) → (b : (σ →₀ ℕ) × (σ →₀ ℕ)) → motive (fst, b)) → motive x