A person on a blue scooter waits at a crosswalk.
Person riding a blue scooter
A person must be on a scooter to be riding a scooter.
exists s1 x1 x2 x3 x4.(a_topic(x1) & at(x1,x4) & n_crosswalk(x4) & on(x1,x2) & n_wait(x2) & of(x2,x3) & n_scooter(x3) & a_blue(s1) & Theme(s1,x2) & n_person(x1))
exists e1 s1 x1 x2.(ne_nam_person(x1) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_scooter(x2) & a_blue(s1) & Theme(s1,x2))