TIMEOUT
MAYBE
Trs:
 {               U12(tt()) -> tt(),
              __(nil(), X) -> X,
           __(__(X, Y), Z) -> __(X, __(Y, Z)),
              __(X, nil()) -> X,
  isNePal(__(I, __(P, I))) -> U11(tt()),
                 U11(tt()) -> U12(tt()),
               activate(X) -> X}
 Open