| i1 / gcd(i1, j1) + rational(i2, j2).num = 0, j1 / gcd(i1, j1) + abs(j2) / gcd(i2, j2) = 0, i1 < 0, j1 < 0 ⊦ i1 = 0, i2 = 0, j1 = 0, j2 = 0, ¬ 0 < i2 ∧ ¬ 0 < j2, i2 / gcd(i2, j2) + i1 / gcd(i1, j1) = 0 ∧ ¬ i2 < 0 ∧ ¬ j2 < 0 |
⊦ 0 < i ∧ j < 0 → rational(i, j).num = ~(i / gcd(i, j))
¬(0 < i2 ∧ j2 < 0), i1 / gcd(i1, j1) + rational(i2, j2).num = 0, j1 / gcd(i1, j1) + abs(j2) / gcd(i2, j2) = 0, i1 < 0, j1 < 0 ⊦ i1 = 0, i2 = 0, j1 = 0, j2 = 0, ¬ 0 < i2 ∧ ¬ 0 < j2, i2 / gcd(i2, j2) + i1 / gcd(i1, j1) = 0 ∧ ¬ i2 < 0 ∧ ¬ j2 < 0
0 < i2 ∧ j2 < 0, i1 / gcd(i1, j1) + ~(i2 / gcd(i2, j2)) = 0, j1 / gcd(i1, j1) + abs(j2) / gcd(i2, j2) = 0, i1 < 0, j1 < 0 ⊦ i1 = 0, i2 = 0, j1 = 0, j2 = 0, ¬ 0 < i2 ∧ ¬ 0 < j2, i2 / gcd(i2, j2) + i1 / gcd(i1, j1) = 0 ∧ ¬ i2 < 0 ∧ ¬ j2 < 0
Used terms: j2, i2