⊦ i * i ≤ j * j ↔ abs(i) ≤ abs(j)
i * i ≤ 1 * 1 ↔ abs(i) ≤ abs(1), i * i ≤ 1 ⊦ i + 1 = 0, i = 0, i = 1
Used terms: i, 1