A man in an orange vest works on fixing a train.
A man is working on an engine.
Works on a train does not imply working on an engine.
exists e1 e2 x1 x2 x3 x4 x5.(on(e1,e2) & Theme(e2,x5) & Actor(e2,x4) & v_fix(e2) & n_train(x5) & 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.(on(e1,x2) & n_engine(x2) & Actor(e1,x1) & v_work(e1) & n_man(x1))