| ⊦ rj = 0r, rational(rj.denom * ri.num, ~(rj.num * ri.denom)) = ~(ri / rj) |
⊦ j ≠ 0 → rational(i, ~ j) = rational(~ i, j)
¬ rj.num * ri.denom ≠ 0 ⊦ rj = 0r, rational(rj.denom * ri.num, ~(rj.num * ri.denom)) = ~(ri / rj)
rj.num * ri.denom ≠ 0 ⊦ rj = 0r, rational(~(rj.denom * ri.num), rj.num * ri.denom) = ~(ri / rj)
Used terms: rj.num * ri.denom, rj.denom * ri.num