Used simplifier rules: eq: ⊦ m0 ≠ 0 → (m * m0 = n * m0 ↔ m = n);%mult-a: ⊦ m0 * m * n = (m0 * m) * n;%mult-c: ⊦ m * n = n * m;%zero: ⊦ 0 * n = 0;