Two motocross riders sit on the shoulder of the racetrack.
The motocross riders are wearing their helmets.
The motocross riders are not necessarily wearing their helmets.
exists e1 x1 x2 x3 x4.(n_racetrack(x4) & n_shoulder(x3) & on(e1,x3) & of(x3,x4) & Actor(e1,x1) & v_sit(e1) & n_rider(x1) & of(x1,x2) & n_motocross(x2) & card_eq_2(x1))
exists e1 x1 x2 x3.(n_helmet(x3) & of(x3,x1) & n_thing(x1) & n_rider(x1) & of(x1,x2) & n_motocross(x2) & Theme(e1,x3) & Actor(e1,x1) & v_wear(e1))