| perm(a ' + x, ins≤(a, x)), perm(ins≤(a, x), a ' + x) ⊦ perm(ins≤(a, x), y) ↔ perm(a ' + x, y) |
Used simplifier rules: trans: ⊦ perm(x, y) ∧ perm(y, z) → perm(x, z); (forward) from specification list-perm%sym-01: ⊦ perm(x, y) → perm(y, x); (forward) from specification list-perm%sym-02: ⊦ ¬ perm(x, y) → ¬ perm(y, x); (forward) from specification list-perm