Some people sitting inside a running train.
There are people in a moving train.
The people who are in the moving train are sitting down.
exists e1 e2 x1 x2 x3.(a_topic(x1) & inside(e1,x3) & n_train(x3) & Actor(e2,x3) & v_run(e2) & Actor(e1,x2) & v_sit(e1) & (x1 = x2) & n_people(x1))
exists e1 p1 x1 x2.(in(p1,x2) & n_train(x2) & Actor(e1,x2) & v_move(e1) & exists x3.((x1 = x3) & n_people(x3)))