Two motorcycles race on a track.
Professional racers ride motrocycles.
Not all racers are professional.
exists x1 x2 x3.(a_topic(x1) & on(x1,x3) & n_track(x3) & n_race(x1) & of(x1,x2) & n_motorcycle(x2) & card_eq_2(x1))
exists e1 x1 x2 x3.(Theme(e1,x3) & Actor(e1,x1) & v_ride(e1) & n_motrocycle(x3) & n_racer(x1) & (x1 = x2) & ne_nam_professional(x2))