A bunch of people at a train station.
A group of people are waiting for the train to arrive.
People can be doing things other than waiting for the train to arrive while at a train station.
exists x1 x2 x3 x4.(a_topic(x1) & at(x1,x3) & n_station(x3) & of(x3,x4) & n_train(x4) & of(x1,x2) & n_people(x2) & n_bunch(x1))
exists e1 p1 x1 x2 x3.(n_train(x3) & Topic(e1,p1) & Actor(e1,x1) & v_wait(e1) & exists e2.(Actor(e2,x3) & v_arrive(e2)) & of(x1,x2) & n_people(x2) & n_group(x1))