People sitting in a vehicle.
Some people are on the way to work on the train.
People sitting in a vehicle are not necessarily on the way to work and not necessarily on the train.
exists e1 x1 x2 x3.(a_topic(x1) & in(e1,x3) & n_vehicle(x3) & Actor(e1,x2) & v_sit(e1) & (x1 = x2) & n_people(x1))
exists p1 x1 x2 x3.(n_train(x3) & n_way(x2) & exists p2.(on(x1,x2) & Topic(x2,p2) & exists e1.(on(e1,x3) & Actor(e1,x2) & v_work(e1))) & n_people(x1))