Many people on a train hold onto handles.
People riding a train.
The people are holding onto handles so they must be riding a train.
exists x1 x2 x3 x4.(a_topic(x1) & on(x1,x2) & onto(x2,x4) & n_handle(x4) & n_hold(x2) & of(x2,x3) & n_train(x3) & n_people(x1) & n_quantity(x1))
exists e1 x1 x2 x3.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_ride(e1) & n_train(x3) & (x1 = x2) & n_people(x1))