Man working on the railroad.
The man is on a train.
THE RAILROAD IS NOT THE SAME AS THE TRAIN
exists e1 x1 x2 x3.(n_railroad(x3) & a_topic(x1) & on(e1,x3) & Actor(e1,x2) & v_work(e1) & (x1 = x2) & n_man(x1))
exists p1 x1.(n_man(x1) & exists x2.(on(x1,x2) & n_train(x2)))