A man plays a whistle.
The man is playing the guitar.
If a man plays a whistle he is not playing the guitar.
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_whistle(x2) & n_man(x1))
exists e1 x1 x2.(n_guitar(x2) & n_man(x1) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1))