MAYBE
MAYBE
TRS:
 {
             mark(cons(X1, X2)) -> active(cons(mark(X1), X2)),
                  mark(from(X)) -> active(from(mark(X))),
                     mark(s(X)) -> active(s(mark(X))),
              mark(sel(X1, X2)) -> active(sel(mark(X1), mark(X2))),
                      mark(0()) -> active(0()),
             cons(X1, mark(X2)) -> cons(X1, X2),
           cons(X1, active(X2)) -> cons(X1, X2),
             cons(mark(X1), X2) -> cons(X1, X2),
           cons(active(X1), X2) -> cons(X1, X2),
                  from(mark(X)) -> from(X),
                from(active(X)) -> from(X),
                     s(mark(X)) -> s(X),
                   s(active(X)) -> s(X),
                active(from(X)) -> mark(cons(X, from(s(X)))),
  active(sel(s(X), cons(Y, Z))) -> mark(sel(X, Z)),
   active(sel(0(), cons(X, Y))) -> mark(X),
              sel(X1, mark(X2)) -> sel(X1, X2),
            sel(X1, active(X2)) -> sel(X1, X2),
              sel(mark(X1), X2) -> sel(X1, X2),
            sel(active(X1), X2) -> sel(X1, X2)
 }
 DUP: We consider a duplicating system.
  Trs:
   {
               mark(cons(X1, X2)) -> active(cons(mark(X1), X2)),
                    mark(from(X)) -> active(from(mark(X))),
                       mark(s(X)) -> active(s(mark(X))),
                mark(sel(X1, X2)) -> active(sel(mark(X1), mark(X2))),
                        mark(0()) -> active(0()),
               cons(X1, mark(X2)) -> cons(X1, X2),
             cons(X1, active(X2)) -> cons(X1, X2),
               cons(mark(X1), X2) -> cons(X1, X2),
             cons(active(X1), X2) -> cons(X1, X2),
                    from(mark(X)) -> from(X),
                  from(active(X)) -> from(X),
                       s(mark(X)) -> s(X),
                     s(active(X)) -> s(X),
                  active(from(X)) -> mark(cons(X, from(s(X)))),
    active(sel(s(X), cons(Y, Z))) -> mark(sel(X, Z)),
     active(sel(0(), cons(X, Y))) -> mark(X),
                sel(X1, mark(X2)) -> sel(X1, X2),
              sel(X1, active(X2)) -> sel(X1, X2),
                sel(mark(X1), X2) -> sel(X1, X2),
              sel(active(X1), X2) -> sel(X1, X2)
   }
  Fail