MAYBE
MAYBE
TRS:
 {
   app(app(app(app(filter2(), true()), f), x), xs) ->
  app(app(cons(), x), app(app(filter(), f), xs)),
  app(app(app(app(filter2(), false()), f), x), xs) ->
  app(app(filter(), f), xs),
       app(app(rev1(), x), app(app(cons(), y), l)) -> app(app(rev1(), y), l),
              app(app(rev1(), app(s(), x)), nil()) -> app(s(), x),
                      app(app(rev1(), 0()), nil()) -> 0(),
                        app(app(rev2(), x), nil()) -> nil(),
       app(app(rev2(), x), app(app(cons(), y), l)) ->
  app(rev(), app(app(cons(), x), app(app(rev2(), y), l))),
                         app(app(map(), f), nil()) -> nil(),
       app(app(map(), f), app(app(cons(), x), xs)) ->
  app(app(cons(), app(f, x)), app(app(map(), f), xs)),
                      app(app(filter(), f), nil()) -> nil(),
    app(app(filter(), f), app(app(cons(), x), xs)) ->
  app(app(app(app(filter2(), app(f, x)), f), x), xs),
                                 app(rev(), nil()) -> nil(),
                app(rev(), app(app(cons(), x), l)) ->
  app(app(cons(), app(app(rev1(), x), l)), app(app(rev2(), x), l))
 }
 DUP: We consider a duplicating system.
  Trs:
   {
     app(app(app(app(filter2(), true()), f), x), xs) ->
    app(app(cons(), x), app(app(filter(), f), xs)),
    app(app(app(app(filter2(), false()), f), x), xs) ->
    app(app(filter(), f), xs),
         app(app(rev1(), x), app(app(cons(), y), l)) ->
    app(app(rev1(), y), l),
                app(app(rev1(), app(s(), x)), nil()) -> app(s(), x),
                        app(app(rev1(), 0()), nil()) -> 0(),
                          app(app(rev2(), x), nil()) -> nil(),
         app(app(rev2(), x), app(app(cons(), y), l)) ->
    app(rev(), app(app(cons(), x), app(app(rev2(), y), l))),
                           app(app(map(), f), nil()) -> nil(),
         app(app(map(), f), app(app(cons(), x), xs)) ->
    app(app(cons(), app(f, x)), app(app(map(), f), xs)),
                        app(app(filter(), f), nil()) -> nil(),
      app(app(filter(), f), app(app(cons(), x), xs)) ->
    app(app(app(app(filter2(), app(f, x)), f), x), xs),
                                   app(rev(), nil()) -> nil(),
                  app(rev(), app(app(cons(), x), l)) ->
    app(app(cons(), app(app(rev1(), x), l)), app(app(rev2(), x), l))
   }
  Fail