Four dirt bike riders are riding on a dirt road.
Dirt bike riders are doing repairs to their bikes.
Dirt bike riders cannot be riding while they do repairs.
exists e1 x1 x2 x3 x4 x5.(on(e1,x4) & n_road(x4) & of(x4,x5) & n_dirt(x5) & Actor(e1,x1) & v_ride(e1) & n_rider(x1) & of(x1,x3) & n_bike(x3) & of(x1,x2) & n_dirt(x2) & card_eq_4(x1))
exists e1 x1 x2 x3 x4.(to(e1,x3) & n_bike(x3) & n_bike(x3) & of(x3,x1) & n_thing(x1) & Theme(e1,x4) & Actor(e1,x1) & v_do(e1) & n_repair(x4) & n_rider(x1) & of(x1,x3) & (x1 = x2) & ne_nam_dirt(x2))