TRS:
 {          a__nats() -> a__adx(a__zeros()),
           a__zeros() -> cons(0(), zeros()),
  a__incr(cons(X, Y)) -> cons(s(X), incr(Y)),
   a__adx(cons(X, Y)) -> a__incr(cons(X, adx(Y))),
    a__hd(cons(X, Y)) -> mark(X),
    a__tl(cons(X, Y)) -> mark(Y),
         mark(nats()) -> a__nats(),
         mark(adx(X)) -> a__adx(mark(X)),
        mark(zeros()) -> a__zeros(),
        mark(incr(X)) -> a__incr(mark(X)),
          mark(hd(X)) -> a__hd(mark(X)),
          mark(tl(X)) -> a__tl(mark(X)),
   mark(cons(X1, X2)) -> cons(X1, X2),
            mark(0()) -> 0(),
           mark(s(X)) -> s(X),
            a__nats() -> nats(),
            a__adx(X) -> adx(X),
           a__zeros() -> zeros(),
           a__incr(X) -> incr(X),
             a__hd(X) -> hd(X),
             a__tl(X) -> tl(X)}
 Fail