| ⊦ i = 0, j = 0, rational(i, j).num + rational(~ i, j).num = 0 |
⊦ i ≠ 0 ∧ 0 < j → rational(i, j).num = i / gcd(i, j)
¬(i ≠ 0 ∧ 0 < j) ⊦ i = 0, j = 0, rational(i, j).num + rational(~ i, j).num = 0
i ≠ 0 ∧ 0 < j ⊦ i = 0, j = 0, i / gcd(i, j) + rational(~ i, j).num = 0
Used terms: j, i