A man is sitting in a chair playing a guitar.
The man is playing a classical piece.
You can not infer he is playing a classical piece.
exists e1 e2 x1 x2 x3.(for(e1,e2) & Theme(e2,x3) & Actor(e2,x1) & v_play(e2) & n_guitar(x3) & in(e1,x2) & n_chair(x2) & Actor(e1,x1) & v_sit(e1) & n_man(x1))
exists e1 s1 x1 x2.(n_man(x1) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_piece(x2) & a_classical(s1) & Theme(s1,x2))