| j * i + j0 ≤ j * i0 + j1, abs(j0) < j, abs(j1) < j, i0 < i, j * i0 + abs(j0) < j * i + abs(j1), j0 ≤ 0, j1 ≤ 0 ⊦ |
⊦ j < 0 → abs(j) = 0 - j
¬ j0 < 0, j * i + j0 ≤ j * i0 + j1, abs(j0) < j, abs(j1) < j, i0 < i, j * i0 + abs(j0) < j * i + abs(j1), j0 ≤ 0, j1 ≤ 0 ⊦
j0 < 0, j * i + j0 ≤ j * i0 + j1, 0 - j0 < j, abs(j1) < j, i0 < i, j * i0 + (0 - j0) < j * i + abs(j1), j0 ≤ 0, j1 ≤ 0 ⊦
Used terms: j0