| 0 < j ∧ 0 < j1, 0 < j, 0 < j0, 0 < j1 ⊦ rational(i0, j0) = rational(i, j) + rational(~ i1, j1) ↔ rational(i, j) = rational(i0, j0) + rational(i1, j1) |
0 < j1, 0 < j0, 0 < j ⊦ rational(i0, j0) = rational(i, j) + rational(~ i1, j1) ↔ rational(i, j) = rational(i0, j0) + rational(i1, j1)