Two people are turning a corner while riding dirt bikes on a dirt course.
The two dirt bike riders are racing to see who is faster.
Just because people are riding dirt bikes it does not mean they are dirt bike riders.  Just because people are ridding dirt bikes it does not mean they are racing.
exists e1 e2 x1 x2 x3 x4 x5 x6.(while(e1,e2) & on(e2,x5) & n_course(x5) & of(x5,x6) & n_dirt(x6) & Theme(e2,x3) & Actor(e2,x1) & v_ride(e2) & n_bike(x3) & of(x3,x4) & n_dirt(x4) & Theme(e1,x2) & Actor(e1,x1) & v_turn(e1) & n_corner(x2) & n_people(x1) & card_eq_2(x1))
exists e1 p1 x1 x2 x3.(n_rider(x1) & of(x1,x3) & n_bike(x3) & of(x1,x2) & n_dirt(x2) & card_eq_2(x1) & Topic(e1,p1) & Actor(e1,x1) & v_race(e1) & exists e2 s1 x4.(Topic(e2,s1) & Theme(s1,x4) & a_faster(s1) & n_person(x4) & Actor(e2,x1) & v_see(e2)))