A group of people dancing on stage.
A group watching a movie.
If a group is dancing on stage they are not watching a movie.
exists e1 x1 x2 x3 x4.(a_topic(x1) & of(x1,x2) & on(e1,x4) & n_stage(x4) & Actor(e1,x3) & v_dance(e1) & (x2 = x3) & n_people(x2) & n_group(x1))
exists e1 x1 x2 x3.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_watch(e1) & n_movie(x3) & (x1 = x2) & n_group(x1))