| 0 < i, 0 < i0, 0 < j, 0 < j0 ⊦ j = 0, i = 0, j0 = 0, i0 = 0, rational(i / gcd(i, j) * j0 / gcd(i0, j0), j / gcd(i, j) * i0 / gcd(i0, j0)) = rational(i * j0, j * i0) |
⊦ 0 < j ∧ 0 < j0 → (rational(i, j) = rational(i0, j0) ↔ i * j0 = i0 * j)
¬(0 < j / gcd(i, j) * i0 / gcd(i0, j0) ∧ 0 < j * i0), 0 < i, 0 < i0, 0 < j, 0 < j0 ⊦ j = 0, i = 0, j0 = 0, i0 = 0, rational(i / gcd(i, j) * j0 / gcd(i0, j0), j / gcd(i, j) * i0 / gcd(i0, j0)) = rational(i * j0, j * i0)
0 < j / gcd(i, j) * i0 / gcd(i0, j0) ∧ 0 < j * i0, 0 < i, 0 < i0, 0 < j, 0 < j0 ⊦ j = 0, i = 0, j0 = 0, i0 = 0, (i / gcd(i, j) * j0 / gcd(i0, j0)) * j * i0 = (i * j0) * j / gcd(i, j) * i0 / gcd(i0, j0)
Used terms: j * i0, i * j0, j / gcd(i, j) * i0 / gcd(i0, j0), i / gcd(i, j) * j0 / gcd(i0, j0)