a boy screams.
A boy is playing the trumpet.
A boy either screams or is playing the trumpet.
exists e1 x1.(Actor(e1,x1) & v_scream(e1) & n_boy(x1))
exists e1 x1 x2.(n_trumpet(x2) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_boy(x1))