A man in a black shirt and hat plays guitar.
The man is good at guitar.
Plays a guitar does not mean he is good.
exists e1 s1 x1 x2 x3 x4 x5.(Theme(e1,x5) & Actor(e1,x1) & v_play(e1) & n_guitar(x5) & in(x1,x2) & n_hat(x4) & n_shirt(x3) & a_black(s1) & Theme(s1,x3) & subset_of(x4,x2) & subset_of(x3,x2) & n_man(x1))
exists s1 x1 x2.(n_man(x1) & at(s1,x2) & n_guitar(x2) & Theme(s1,x1) & a_good(s1))