| i / max_prime_divisor(i) < 2, 0 < i, i / max_prime_divisor(i) < i, 2 ≤ i, 0 ≤ i, ¬ prime(i) ∧ 2 ≤ i → (∃ i0. max_prime_divisor(i) * i0 = i) ⊦ prime(i) |
max_prime_divisor(i) * i0 = i, i / max_prime_divisor(i) < i, 0 < i, i / max_prime_divisor(i) < 2, 0 ≤ i, 2 ≤ i ⊦ prime(i)