Man working on the railroad.
The man is fixing a bent rail.
Working on the railroad does not imply fixing a bent rail.
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 e1 s1 x1 x2.(n_man(x1) & Theme(e1,x2) & Actor(e1,x1) & v_fix(e1) & n_rail(x2) & a_bent(s1) & Theme(s1,x2))