Two men are playing their guitars and singing on stage.
An orchestra playing in an opera hall.
The men can't play guitars and sing while the orchestra is playing.
exists e2 e1 x1 x2 x3 x4.(on(e2,x4) & n_stage(x4) & Actor(e2,x3) & v_sing(e2) & n_man(x3) & card_eq_2(x3) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_guitar(x2) & of(x2,x1) & n_thing(x1) & n_man(x1) & card_eq_2(x1))
exists x1 x2 x3 x4.(a_topic(x1) & in(x1,x3) & n_hall(x3) & of(x3,x4) & n_opera(x4) & n_playing(x1) & of(x1,x2) & n_orchestra(x2))