Two cars race down a track.
Two competitors are racing.
Just because two people are racing does not mean that they are competitors.  They could be teammates practicing.
exists x1 x2 x3.(a_topic(x1) & down(x1,x3) & n_track(x3) & n_race(x1) & of(x1,x2) & n_car(x2) & card_eq_2(x1))
exists e1 x1.(Actor(e1,x1) & v_race(e1) & n_competitor(x1) & card_eq_2(x1))