MAYBE
MAYBE
TRS:
 {
      U12(tt()) -> s(plus(N, M)),
      U11(tt()) -> U12(tt()),
  plus(N, s(M)) -> U11(tt()),
   plus(N, 0()) -> N
 }
 DUP: We consider a duplicating system.
  Trs:
   {
        U12(tt()) -> s(plus(N, M)),
        U11(tt()) -> U12(tt()),
    plus(N, s(M)) -> U11(tt()),
     plus(N, 0()) -> N
   }
  Fail