Two boys fight for the ball.
Two boys are fighting.
Two boys who fight for the ball are fighting.
exists x1 x2 x3.(n_ball(x3) & a_topic(x1) & for(x1,x3) & n_fight(x1) & of(x1,x2) & n_boy(x2) & card_eq_2(x1))
exists e1 x1.(Actor(e1,x1) & v_fight(e1) & n_boy(x1) & card_eq_2(x1))