A mountain bike racer jumps his bike as spectators watch.
Nobody who is depicted is sitting on anything like a vehicle or surface.
The person cannot be not sitting on anything while he jumps his bike because he would have to be on the bike to jump it.
exists e1 e2 x1 x2 x3 x4 x5 x6.(Theme(e2,x6) & Actor(e2,x1) & v_watch(e2) & n_thing(x6) & Theme(e1,x3) & Actor(e1,x4) & v_jump(e1) & as(x3,x5) & n_spectator(x5) & n_bike(x3) & n_bike(x3) & of(x3,x1) & n_male(x1) & (x1 = x4) & n_racer(x1) & of(x1,x3) & of(x1,x2) & n_mountain(x2))
-exists e2 e1 x1 x2.(all x3.(n_thing(x3) -> exists x4.(on(e2,x3) & like(x3,x4) & (n_vehicle(x4) | n_surface(x4)))) & Actor(e2,x1) & v_sit(e2) & Theme(e1,x2) & v_depict(e1) & (x1 = x2) & n_person(x1))