People riding bicycles at night on a track.
People riding their bikes at night
People riding bicycles at night is another way of saying People riding bikes at night.
exists e1 x1 x2 x3 x4 x5.(a_topic(x1) & on(e1,x5) & n_track(x5) & at(e1,x4) & n_night(x4) & Theme(e1,x3) & Actor(e1,x2) & v_ride(e1) & n_bicycle(x3) & (x1 = x2) & n_people(x1))
exists e1 x1 x2 x3 x4.(a_topic(x1) & at(e1,x4) & n_night(x4) & Theme(e1,x3) & Actor(e1,x2) & v_ride(e1) & n_bike(x3) & of(x3,x1) & n_thing(x1) & (x1 = x2) & n_people(x1))