dirt bike racing one guy on ground
the bike is a bmx
A racer can use any bike other than bmx
exists e1 x1 x2 x3 x4 x5.(a_topic(x1) & on(e1,x5) & n_ground(x5) & Theme(e1,x4) & Actor(e1,x3) & v_race(e1) & n_guy(x4) & card_eq_1(x4) & (x1 = x3) & n_bike(x1) & of(x1,x2) & n_dirt(x2))
exists p1 x1.(n_bike(x1) & exists x2.((x1 = x2) & n_bmx(x2)))