Used simplifier rules: ls-02: ⊦ i < i + j ↔ 0 < j;%add-a: ⊦ i + j + i0 = (i + j) + i0;%add-c: ⊦ i + j = j + i;% ⊦ i < j → ¬ j < i; (s)%lf-02: ⊦ i < j ∧ j = i0 → i < i0; (forward) from specification int-basic1