Two guys on guitar and one guy on the drums are performing in a band.
Two guys are are performing.
Two guys on guitar and one on drums mean there are three guys performing not two guys
exists e1 x1 x2 x3 x4 x5 x6.(n_drum(x5) & in(e1,x6) & n_band(x6) & Actor(e1,x1) & v_perform(e1) & subset_of(x4,x1) & on(x4,x5) & n_guy(x4) & card_eq_1(x4) & subset_of(x2,x1) & on(x2,x3) & n_guitar(x3) & n_guy(x2) & card_eq_2(x2))
exists e2 e1 x1 x2.(Actor(e2,x1) & v_perform(e2) & Actor(e1,x2) & v_be(e1) & (x1 = x2) & n_guy(x1) & card_eq_2(x1))