A group of children sit on stage.
children wait for play
Not all children sit on stage are waiting for a play
exists e1 x1 x2 x3.(on(e1,x3) & n_stage(x3) & Actor(e1,x1) & v_sit(e1) & of(x1,x2) & n_child(x2) & n_group(x1))
exists e1 x1 x2.(for(e1,x2) & n_play(x2) & Actor(e1,x1) & v_wait(e1) & n_child(x1))