A group of people walking in front of a subway rail.
A group of people waiting for a subway car to arrive.
People walking near the subways are not necessarily waiting for a subway car to arrive, they could just be walking.
exists e1 x1 x2 x3 x4 x5 x6.(a_topic(x1) & of(x1,x2) & in(e1,x4) & of(x4,x5) & n_rail(x5) & of(x5,x6) & n_subway(x6) & n_front(x4) & Actor(e1,x3) & v_walk(e1) & (x2 = x3) & n_people(x2) & n_group(x1))
exists e1 p1 x1 x2 x3 x4 x5.(a_topic(x1) & of(x1,x2) & for(e1,x4) & Topic(x4,p1) & exists e2.(Actor(e2,x4) & v_arrive(e2)) & n_car(x4) & of(x4,x5) & n_subway(x5) & Actor(e1,x3) & v_wait(e1) & (x2 = x3) & n_people(x2) & n_group(x1))