| abs(i0) = abs(i), i < 0, j | abs(i) ⊦ j | i ∧ j | i0 |
i + abs(i0) = 0, i < 0, j | i ⊦ j | i0
Used simplifier rules: div-neg: ⊦ i | ~ j ↔ i | j;%forward-le-02: ⊦ j < i ∧ i ≤ 0 → j < 0; (forward) from specification int-abs% ⊦ ~ i = j ↔ i + j = 0; (s)% ⊦ i < 0 → abs(i) = ~ i; (s)