(i + j) / 2 < i, (i + j) / 2 < j, i + j < 0, i ≤ j ⊦
Used simplifier rules: forward-le-02: ⊦ j < i ∧ i ≤ 0 → j < 0; (forward) from specification int-abs% ⊦ i ≤ j ↔ ¬ j < i; (ss)