One man sings while another plays guitar during a stage show.
Two men play brass instruments on a stage.
The two men cannot play brass instruments while one sings and the other plays the guitar
(x)
exists e1 x1 x2 x3 x4.(on(e1,x4) & n_stage(x4) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_instrument(x2) & of(x2,x3) & n_brass(x3) & n_man(x1) & card_eq_2(x1))