Three people on stage singing and playing instruments.
 Three people singing and playing instruments.
people singing and playing instruments is same as people singing and playing instruments
exists x1 x2 x3 x4 x5.(a_topic(x1) & on(x1,x2) & n_instrument(x2) & of(x2,x5) & n_playing(x5) & of(x2,x4) & n_singing(x4) & of(x2,x3) & n_stage(x3) & n_people(x1) & card_eq_3(x1))
exists e2 e1 x1 x2 x3 x4.(Theme(e2,x4) & Actor(e2,x3) & v_play(e2) & n_instrument(x4) & n_people(x3) & card_eq_3(x3) & Theme(e1,x2) & Actor(e1,x1) & v_sing(e1) & n_instrument(x2) & n_people(x1) & card_eq_3(x1))