MAYBE
MAYBE
TRS:
 {
                cons(mark(X1), X2) -> mark(cons(X1, X2)),
              cons(ok(X1), ok(X2)) -> ok(cons(X1, X2)),
                     from(mark(X)) -> mark(from(X)),
                       from(ok(X)) -> ok(from(X)),
                        s(mark(X)) -> mark(s(X)),
                          s(ok(X)) -> ok(s(X)),
              active(cons(X1, X2)) -> cons(active(X1), X2),
                   active(from(X)) -> mark(cons(X, from(s(X)))),
                   active(from(X)) -> from(active(X)),
                      active(s(X)) -> s(active(X)),
             active(after(X1, X2)) -> after(X1, active(X2)),
             active(after(X1, X2)) -> after(active(X1), X2),
  active(after(s(N), cons(X, XS))) -> mark(after(N, XS)),
            active(after(0(), XS)) -> mark(XS),
               after(X1, mark(X2)) -> mark(after(X1, X2)),
               after(mark(X1), X2) -> mark(after(X1, X2)),
             after(ok(X1), ok(X2)) -> ok(after(X1, X2)),
              proper(cons(X1, X2)) -> cons(proper(X1), proper(X2)),
                   proper(from(X)) -> from(proper(X)),
                      proper(s(X)) -> s(proper(X)),
             proper(after(X1, X2)) -> after(proper(X1), proper(X2)),
                       proper(0()) -> ok(0()),
                      top(mark(X)) -> top(proper(X)),
                        top(ok(X)) -> top(active(X))
 }
 DUP: We consider a duplicating system.
  Trs:
   {
                  cons(mark(X1), X2) -> mark(cons(X1, X2)),
                cons(ok(X1), ok(X2)) -> ok(cons(X1, X2)),
                       from(mark(X)) -> mark(from(X)),
                         from(ok(X)) -> ok(from(X)),
                          s(mark(X)) -> mark(s(X)),
                            s(ok(X)) -> ok(s(X)),
                active(cons(X1, X2)) -> cons(active(X1), X2),
                     active(from(X)) -> mark(cons(X, from(s(X)))),
                     active(from(X)) -> from(active(X)),
                        active(s(X)) -> s(active(X)),
               active(after(X1, X2)) -> after(X1, active(X2)),
               active(after(X1, X2)) -> after(active(X1), X2),
    active(after(s(N), cons(X, XS))) -> mark(after(N, XS)),
              active(after(0(), XS)) -> mark(XS),
                 after(X1, mark(X2)) -> mark(after(X1, X2)),
                 after(mark(X1), X2) -> mark(after(X1, X2)),
               after(ok(X1), ok(X2)) -> ok(after(X1, X2)),
                proper(cons(X1, X2)) -> cons(proper(X1), proper(X2)),
                     proper(from(X)) -> from(proper(X)),
                        proper(s(X)) -> s(proper(X)),
               proper(after(X1, X2)) -> after(proper(X1), proper(X2)),
                         proper(0()) -> ok(0()),
                        top(mark(X)) -> top(proper(X)),
                          top(ok(X)) -> top(active(X))
   }
  Fail