⊦ i ≤ j ↔ ¬ j < i
1 = i * i0 + j0 * j, gcd(i, j) = 1, 0 < i, i0 < 0 ⊦ i = 0, j < 0, ∃ i0. 0 ≤ i0 ∧ j | i * i0 - 1
Used terms: j, 0