A man, sitting by his computer, playing guitar to his cat.
the guy is playing rock music on his guitar.
The fact that a man is playing guitar doesn't imply that he is playing rock music.
exists e2 e1 x1 x2 x3 x4 x5 x6.(a_topic(x1) & to(e2,x6) & n_cat(x6) & of(x6,x1) & n_male(x1) & n_male(x1) & Theme(e2,x5) & Actor(e2,x4) & v_play(e2) & n_guitar(x5) & (x1 = x4) & by(e1,x3) & n_computer(x3) & of(x3,x1) & Actor(e1,x2) & v_sit(e1) & (x1 = x2) & n_man(x1))
exists e1 x1 x2 x3 x4.(n_guitar(x4) & of(x4,x1) & n_male(x1) & n_guy(x1) & on(e1,x4) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_music(x2) & of(x2,x3) & n_rock(x3))