A man in an orange vest is working on a train.
A maintenance man making repairs.
A man in an orange vest does not imply the man is a maintenance man.
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 x1 x2 x3 x4.(a_topic(x1) & Theme(e1,x4) & Actor(e1,x3) & v_make(e1) & n_repair(x4) & (x1 = x3) & n_man(x1) & of(x1,x2) & n_maintenance(x2))