A guy is playing a bass guitar in a room with posters on the wall.
The rock guitarist practices his new song.
The fact that a guy is playing a guitar doesn't imply he is a rock guitarist and doesn't imply he practices his new song.
exists e1 x1 x2 x3 x4 x5 x6.(n_wall(x6) & on(e1,x6) & in(e1,x4) & with(x4,x5) & n_poster(x5) & n_room(x4) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_guitar(x2) & of(x2,x3) & n_bass(x3) & n_guy(x1))
exists e1 s1 x1 x2 x3.(n_song(x3) & a_new(s1) & Theme(s1,x3) & of(x3,x1) & n_male(x1) & n_guitarist(x1) & of(x1,x2) & n_rock(x2) & Theme(e1,x3) & Actor(e1,x1) & v_practice(e1))