∀ n. ii(n) ≤ ii(n + 1) ⊦ ∃ m. n ≤ ii(m), ∃ n0. ∀ m. n0 ≤ m → ii(m) = ii(n0)
Used simplifier rules: ge: ⊦ n ≥ m ↔ m ≤ n; from specification nat