| ¬(0 < abs(i) - abs(i0) ∧ abs(i) - abs(i0) < abs(i)), i < 0 ⊦ abs(i) < i0, i0 < 0, gcd(abs(i) - abs(i0), abs(i)) = gcd(abs(i) - abs(i0), abs(i0)), 0 < i ∧ i < i0 + i |
i < 0 ⊦ 0 < abs(i) - abs(i0) ∧ abs(i) - abs(i0) < abs(i), abs(i) < i0, i0 < 0, gcd(abs(i) - abs(i0), abs(i)) = gcd(abs(i) - abs(i0), abs(i0)), 0 < i ∧ i < i0 + i