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