Used simplifier rules: mone-06: ⊦ ~1 < i ↔ 0 ≤ i;%lels-03: ⊦ i < j → (j ≤ i ↔ false);%numlsf: ⊦ i < (* j) ∧ j < 0 → i < 0; (forward) from specification int-basic1% ⊦ ¬ i < j → (i = j ↔ ¬ j < i); (ss)