| 0 < j ⊦ rational(i, j) * (rj + rj0) = rational(i, j) * rj + rational(i, j) * rj0 |
⊦ ∃ i, j. ri = rational(i, j) ∧ 0 < j
∃ i, j. rj = rational(i, j) ∧ 0 < j, 0 < j ⊦ rational(i, j) * (rj + rj0) = rational(i, j) * rj + rational(i, j) * rj0
Used terms: rj