MAYBE
MAYBE
TRS:
 {
  app(app(app(fold(), f), x), app(app(cons(), y), z)) ->
  app(app(f, y), app(app(app(fold(), f), x), z)),
                   app(app(app(fold(), f), x), nil()) -> x,
                     app(app(plus(), app(s(), x)), y) ->
  app(s(), app(app(plus(), x), y)),
                             app(app(plus(), 0()), y) -> y,
                    app(app(times(), app(s(), x)), y) ->
  app(app(plus(), app(app(times(), x), y)), y),
                            app(app(times(), 0()), y) -> 0(),
                                                sum() ->
  app(app(fold(), add()), 0()),
                                               prod() ->
  app(app(fold(), mul()), app(s(), 0()))
 }
 DUP: We consider a duplicating system.
  Trs:
   {
    app(app(app(fold(), f), x), app(app(cons(), y), z)) ->
    app(app(f, y), app(app(app(fold(), f), x), z)),
                     app(app(app(fold(), f), x), nil()) -> x,
                       app(app(plus(), app(s(), x)), y) ->
    app(s(), app(app(plus(), x), y)),
                               app(app(plus(), 0()), y) -> y,
                      app(app(times(), app(s(), x)), y) ->
    app(app(plus(), app(app(times(), x), y)), y),
                              app(app(times(), 0()), y) -> 0(),
                                                  sum() ->
    app(app(fold(), add()), 0()),
                                                 prod() ->
    app(app(fold(), mul()), app(s(), 0()))
   }
  Fail