1 < i, 0 < i, 4 ^ i ≤ (i + 1) * (i + 1), ∀ i0. i→n(i0) < i→n(i) → 0 < i0 ∧ 1 < i0 ∧ 4 ^ i0 ≤ (i0 + 1) * (i0 + 1) → false ⊦