| ⊦ #oc(a, x ++ b) = #oc(a, x), a = b |
⊦ ¬ a ∈ x → x ++ a = a + x
Used simplifier rules: oc-n: ⊦ a ≠ b → #oc(a, b ' + x) = #oc(a, x);% ⊦ a + x = a ' + x; (s)%a: ⊦ (x + y) + z = x + y + z; from specification list% ⊦ a ∈ x → x ++ a = x; (s) Used terms: b, x