| Π ints2 = Π ints0 * Π(ints1 -1l i), perm(ints2, ints0 + (ints1 -1l i)), i ∈ ints1 ⊦ i * Π ints2 = Π ints0 * Π ints1, i ∈ ints0 |
Used simplifier rules: product-del1-02: ⊦ i ∈ ints → i * Π(ints -1l i) = Π ints;%associativity: ⊦ i * j * j0 = (i * j) * j0; from specification int-mult%commutativity: ⊦ i * j = j * i; from specification int-mult