| j0 < j, i1 < j, 0 < j1, 0 < j, 0 < i0 * j + j0, 0 < ((i0 * i1) * j + j0 * i1) / j, 0 ≤ j0, 0 ≤ i0, i0 * j + j0 ≤ ((i0 * i1) * j + j0 * i1) / j, 0 ≤ i0 * j + j0, 0 ≤ ((i0 * i1) * j + j0 * i1) / j ⊦ |
⊦ i + j = j + i
0 < (j0 * i1 + (i0 * i1) * j) / j, 0 < i0 * j + j0, 0 < j, 0 < j1, i1 < j, j0 < j, 0 ≤ (j0 * i1 + (i0 * i1) * j) / j, 0 ≤ i0 * j + j0, i0 * j + j0 ≤ (j0 * i1 + (i0 * i1) * j) / j, 0 ≤ i0, 0 ≤ j0 ⊦
Used terms: j0 * i1, (i0 * i1) * j