⊦ i0 < 0 → i0 / gcd(i, i0) ≤ 0
i0 < 0 → i0 / gcd(i, i0) ≤ 0, i0 < i0 / gcd(i, i0), i0 < 0, 0 < i0 / gcd(i, i0), i0 + 1 < i0 / gcd(i, i0) ⊦
Used terms: i0, i