# nσ = ⌜n0⌝ + ⌜1⌝ , stutf(nσ), ∀ n. ¬(n ≠ 0 → (∃ m. ¬ n0 < m ∧ nσ[m] = n - 1)) ⊦ nσ[n0] + 1 = 0, ∃ m. ¬ n0 < m ∧ nσ[m] = nσ[n0] + 1 - 1
Used terms: nσ[n0] + 1