| 0 < i1, i * j < i, i * j < j, 0 < i, 0 < j, i * j < i1, i * j ≤ 0, i ≤ i1, ∀ j0, i0. 0 < j0 ∧ i0 ≠ 0 ∧ abs(i0) < i1 → 0 < abs(i0) * j0 ⊦ |
i * j < i1, 0 < j, 0 < i, i * j < j, i * j < i, 0 < i1, i ≤ i1, i * j ≤ 0, 0 < j ∧ i - 1 ≠ 0 ∧ abs(i - 1) < i1 → 0 < abs(i - 1) * j, ∀ j0, i0. 0 < j0 ∧ i0 ≠ 0 ∧ abs(i0) < i1 → 0 < abs(i0) * j0 ⊦
Used terms: j, i - 1