Two men are holding and playing guitars.
Men perform songs while playing guitar.
Men playing guitars does not mean they perform songs.
exists e2 e1 x1 x2 x3 x4.(Theme(e2,x4) & Actor(e2,x3) & v_play(e2) & n_guitar(x4) & n_man(x3) & card_eq_2(x3) & Theme(e1,x2) & Actor(e1,x1) & v_hold(e1) & n_guitar(x2) & n_man(x1) & card_eq_2(x1))
exists e2 e1 x1 x2 x3.(while(e1,e2) & Theme(e2,x3) & Actor(e2,x1) & v_play(e2) & n_guitar(x3) & Theme(e1,x2) & Actor(e1,x1) & v_perform(e1) & n_song(x2) & n_man(x1))