⊦ 2^ m ≤ n ∧ n < 2^ m +1 → log2 n = m
2^(log2 n + 1) ≤ 2 * n + 1 ∧ 2 * n + 1 < 2^ (log2 n + 1)+1 → log2(2 * n + 1) = log2 n + 1 ⊦ log2(2 * n + 1) = log2 n + 1, n = 0
Used terms: log2 n + 1, 2 * n + 1