i * j = i * j0 + j1, abs(j1) < i, 0 ≤ i ⊦ j1 = 0
Used simplifier rules: forward-le-01: ⊦ i ≤ j ∧ 0 ≤ i → 0 ≤ j; (forward) from specification int-abs% ⊦ i < j ↔ ¬ j ≤ i; (ss)