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(head(X)) -> active(head(mark(X))),
                     mark(2nd(X)) -> active(2nd(mark(X))),
                      mark(nil()) -> active(nil()),
               mark(take(X1, X2)) -> active(take(mark(X1), mark(X2))),
                        mark(0()) -> active(0()),
                mark(sel(X1, X2)) -> active(sel(mark(X1), mark(X2))),
               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(head(cons(X, XS))) -> mark(X),
         active(2nd(cons(X, XS))) -> mark(head(XS)),
  active(take(s(N), cons(X, XS))) -> mark(cons(X, take(N, XS))),
            active(take(0(), XS)) -> mark(nil()),
   active(sel(s(N), cons(X, XS))) -> mark(sel(N, XS)),
    active(sel(0(), cons(X, XS))) -> mark(X),
                    head(mark(X)) -> head(X),
                  head(active(X)) -> head(X),
                     2nd(mark(X)) -> 2nd(X),
                   2nd(active(X)) -> 2nd(X),
               take(X1, mark(X2)) -> take(X1, X2),
             take(X1, active(X2)) -> take(X1, X2),
               take(mark(X1), X2) -> take(X1, X2),
             take(active(X1), X2) -> take(X1, X2),
                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(head(X)) -> active(head(mark(X))),
                       mark(2nd(X)) -> active(2nd(mark(X))),
                        mark(nil()) -> active(nil()),
                 mark(take(X1, X2)) -> active(take(mark(X1), mark(X2))),
                          mark(0()) -> active(0()),
                  mark(sel(X1, X2)) -> active(sel(mark(X1), mark(X2))),
                 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(head(cons(X, XS))) -> mark(X),
           active(2nd(cons(X, XS))) -> mark(head(XS)),
    active(take(s(N), cons(X, XS))) -> mark(cons(X, take(N, XS))),
              active(take(0(), XS)) -> mark(nil()),
     active(sel(s(N), cons(X, XS))) -> mark(sel(N, XS)),
      active(sel(0(), cons(X, XS))) -> mark(X),
                      head(mark(X)) -> head(X),
                    head(active(X)) -> head(X),
                       2nd(mark(X)) -> 2nd(X),
                     2nd(active(X)) -> 2nd(X),
                 take(X1, mark(X2)) -> take(X1, X2),
               take(X1, active(X2)) -> take(X1, X2),
                 take(mark(X1), X2) -> take(X1, X2),
               take(active(X1), X2) -> take(X1, X2),
                  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