A man sitting on the ground, playing guitar.
The guitar is black.
There is no indication that the guitar  s black.
exists e1 e2 x1 x2 x3 x4 x5.(n_ground(x3) & a_topic(x1) & Theme(e2,x5) & Actor(e2,x4) & v_play(e2) & n_guitar(x5) & (x1 = x4) & on(e1,x3) & Actor(e1,x2) & v_sit(e1) & (x1 = x2) & n_man(x1))
exists s1 x1.(n_guitar(x1) & Theme(s1,x1) & a_black(s1))