| 0 < j1, 0 < j2 ⊦ rational (rational(i1, j1).num * rational(i2, j2).denom - rational(i1, j1).denom * rational(i2, j2).num, rational(i1, j1).denom * rational(i2, j2).denom) = rational(i1, j1) + rational(~ i2, j2) |
⊦ ri + rj = rational(ri.num * rj.denom + ri.denom * rj.num, ri.denom * rj.denom)
0 < j1, 0 < j2 ⊦ rational (rational(i1, j1).num * rational(i2, j2).denom - rational(i1, j1).denom * rational(i2, j2).num, rational(i1, j1).denom * rational(i2, j2).denom) = rational (rational(i1, j1).num * rational(~ i2, j2).denom + rational(i1, j1).denom * rational(~ i2, j2).num, rational(i1, j1).denom * rational(~ i2, j2).denom)
Used terms: rational(~ i2, j2), rational(i1, j1)