A man is playing the saxophone.
The man is playing the trumpet.
A TRUMPET IS NOT A SAXOPHONE
exists e1 x1 x2.(n_saxophone(x2) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_man(x1))
exists e1 x1 x2.(n_trumpet(x2) & n_man(x1) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1))