Two BMX riders are racing around a bumpy track.
They are riding bikes.
BMX is a brand of bikes
exists e1 s1 x1 x2 x3.(around(e1,x3) & n_track(x3) & a_bumpy(s1) & Theme(s1,x3) & Actor(e1,x1) & v_race(e1) & n_rider(x1) & (x1 = x2) & ne_org_bmx(x2) & card_eq_2(x1))
exists e1 x1 x2.(n_thing(x1) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_bike(x2))