Policemen ride motorcycles through a crowd.
Police ride motorcycles.
Policemen and police are the same thing.
exists s1 x1 x2 x3.(a_topic(x1) & through(x1,x3) & n_crowd(x3) & n_motorcycle(x1) & of(x1,x2) & n_ride(x2) & a_policemen(s1) & Theme(s1,x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_motorcycle(x2) & n_police(x1))