A person on a bmx bike.
A person is using the BMX bike as a vehicle.
A person on a bmx bike shows that person is using the bike as a vehicle.
exists x1 x2 x3.(a_topic(x1) & on(x1,x2) & n_bike(x2) & of(x2,x3) & n_bmx(x3) & n_person(x1))
exists e1 x1 x2 x3 x4.(n_bike(x2) & (x2 = x3) & ne_org_bmx(x3) & Theme(e1,x2) & Actor(e1,x1) & v_use(e1) & as(x2,x4) & n_vehicle(x4) & n_person(x1))