| ⊦ perm(x, rev(x)) |
Used simplifier rules: perm-e: ⊦ perm([], []);%app-02: ⊦ perm(x + y, z + x) ↔ perm(y, z);%neq: ⊦ perm(x, y) ∧ ¬ perm(x0, y) → x ≠ x0;%sym-01: ⊦ perm(x, y) → perm(y, x);%sym-02: ⊦ ¬ perm(x, y) → ¬ perm(y, x);%list freely generated by [], +;;%c: ⊦ a + x = a ' + x; from specification list%rev-r: ⊦ rev(a ' + x) = rev(x) + a; from specification list-last%Last: ⊦ x + a = x + a '; from specification list%a: ⊦ (x + y) + z = x + y + z; from specification list%rev-e: ⊦ rev([]) = []; from specification list-last