People standing and city on a train or bus.
Commuters are riding together to work.
People may use a bus for other reasons than being work commuters.
exists e1 s1 x1 x2 x3 x4.(a_topic(s1) & subset_of(x3,s1) & on(x3,x4) & (n_train(x4) | n_bus(x4)) & n_city(x3) & subset_of(x1,s1) & Actor(e1,x2) & v_stand(e1) & (x1 = x2) & n_people(x1))
exists e1 p1 x1 x2.(to(e1,x2) & n_work(x2) & exists s1.(Theme(s1,x1) & a_together(s1)) & Topic(e1,p1) & Actor(e1,x1) & v_ride(e1) & n_commuter(x1))