A group of people are riding in the back of a truck.
They people are on a train.
The people are on the back of a truck, they are not on a train.
exists e1 x1 x2 x3 x4.(n_back(x3) & in(e1,x3) & of(x3,x4) & n_truck(x4) & Actor(e1,x1) & v_ride(e1) & of(x1,x2) & n_people(x2) & n_group(x1))
exists p1 s1 x1.(exists x2.(on(x1,x2) & n_train(x2)) & n_people(x1) & a_they(s1) & Theme(s1,x1))