| i < 0, 0 < ~ i → (~ i * j0 < ~ i * j ↔ j0 < j) ⊦ i * j < i * j0 ↔ j0 < j |
Used simplifier rules: minus-left: ⊦ ~ i * j = ~(i * j);%associativity: ⊦ i * j * j0 = (i * j) * j0;%commutativity: ⊦ i * j = j * i;% ⊦ ~ j < ~ i ↔ i < j; (s)% ⊦ 0 < ~ i ↔ i < 0; (s)