Two motocross riders sit on the shoulder of the racetrack.
The two riders are standing with their bikes.
They either sit or are standing.
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.(n_bike(x2) & of(x2,x1) & n_thing(x1) & n_rider(x1) & card_eq_2(x1) & with(e1,x2) & Actor(e1,x1) & v_stand(e1))