i = i0 + 1, j % 2 = 0, abs(i) ≤ j, i ≤ 0 ⊦ (i + j) / 2 = i0 / 2 + j / 2
Used simplifier rules: ⊦ i0 = i - j ↔ i = i0 + j; (elim) Used terms: i, 1, i0