Two guys rocking out on guitars.
Two guys are playing rock music on guitars.
Just because two guys are rocking out on guitars it does not mean they are playing rock music.
exists e1 s1 x1 x2 x3.(a_topic(x1) & a_out(s1) & Manner(e1,s1) & on(e1,x3) & n_guitar(x3) & Actor(e1,x2) & v_rock(e1) & (x1 = x2) & n_guy(x1) & card_eq_2(x1))
exists e1 x1 x2 x3 x4.(on(e1,x4) & n_guitar(x4) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_music(x2) & of(x2,x3) & n_rock(x3) & n_guy(x1) & card_eq_2(x1))