A man is playing the saxophone.
The man is a song writer.
Just because a man plays music does not mean he is a song writer.
exists e1 x1 x2.(n_saxophone(x2) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_man(x1))
exists p1 x1.(n_man(x1) & exists x2 x3.((x1 = x2) & n_writer(x2) & of(x2,x3) & n_song(x3)))