A man in an orange vest is working on a train.
A man is working to repair a train.
Working on does not imply working to repair necessarily.
exists e1 x1 x2 x3 x4.(on(e1,x4) & n_train(x4) & Actor(e1,x1) & v_work(e1) & in(x1,x2) & n_vest(x2) & of(x2,x3) & n_orange(x3) & n_man(x1))
exists e1 p1 x1.(Topic(e1,p1) & Actor(e1,x1) & v_work(e1) & exists e2 x2.(Theme(e2,x2) & Actor(e2,x1) & v_repair(e2) & n_train(x2)) & n_man(x1))