A police officer is standing in a doorway.
A policeman is guarding an entrance.
JUST BECAUSE THE POLICEMAN IS STANDING IN A DOORWAY DOES NOT MEAN HE IS GUARDING THE ENTRANCE.
exists e1 x1 x2 x3.(in(e1,x3) & n_doorway(x3) & Actor(e1,x1) & v_stand(e1) & n_officer(x1) & of(x1,x2) & n_police(x2))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_guard(e1) & n_entrance(x2) & n_policeman(x1))