MAYBE
MAYBE
TRS:
 {
             a__zeros() -> cons(0(), zeros()),
             a__zeros() -> zeros(),
         a__U12(X1, X2) -> U12(X1, X2),
        a__U12(tt(), L) -> s(a__length(mark(L))),
         a__U11(X1, X2) -> U11(X1, X2),
        a__U11(tt(), L) -> a__U12(tt(), L),
           a__length(X) -> length(X),
  a__length(cons(N, L)) -> a__U11(tt(), L),
       a__length(nil()) -> 0(),
     mark(cons(X1, X2)) -> cons(mark(X1), X2),
              mark(0()) -> 0(),
          mark(zeros()) -> a__zeros(),
             mark(tt()) -> tt(),
             mark(s(X)) -> s(mark(X)),
            mark(nil()) -> nil(),
      mark(U11(X1, X2)) -> a__U11(mark(X1), X2),
      mark(U12(X1, X2)) -> a__U12(mark(X1), X2),
        mark(length(X)) -> a__length(mark(X))
 }
 DUP: We consider a non-duplicating system.
  Trs:
   {
               a__zeros() -> cons(0(), zeros()),
               a__zeros() -> zeros(),
           a__U12(X1, X2) -> U12(X1, X2),
          a__U12(tt(), L) -> s(a__length(mark(L))),
           a__U11(X1, X2) -> U11(X1, X2),
          a__U11(tt(), L) -> a__U12(tt(), L),
             a__length(X) -> length(X),
    a__length(cons(N, L)) -> a__U11(tt(), L),
         a__length(nil()) -> 0(),
       mark(cons(X1, X2)) -> cons(mark(X1), X2),
                mark(0()) -> 0(),
            mark(zeros()) -> a__zeros(),
               mark(tt()) -> tt(),
               mark(s(X)) -> s(mark(X)),
              mark(nil()) -> nil(),
        mark(U11(X1, X2)) -> a__U11(mark(X1), X2),
        mark(U12(X1, X2)) -> a__U12(mark(X1), X2),
          mark(length(X)) -> a__length(mark(X))
   }
  Fail