Dirt bikers on a trail.
men racing dirt bikes
It cannot be assumed the men are racing.
exists x1 x2 x3.(a_topic(x1) & on(x1,x3) & n_trail(x3) & n_biker(x1) & (x1 = x2) & ne_nam_dirt(x2))
exists e1 x1 x2 x3.(n_bike(x1) & of(x1,x3) & n_dirt(x3) & Actor(e1,x1) & v_race(e1) & of(x1,x2) & n_man(x2) & a_topic(x1))