A group of firemen standing.
A fireman puts his helmet on.
A groupof firemen indicates that there is more than just a fireman.
exists e1 x1 x2 x3.(a_topic(x1) & Actor(e1,x3) & v_stand(e1) & (x1 = x3) & of(x1,x2) & n_fireman(x2) & n_group(x1))
exists e1 s1 x1 x2.(a_on(s1) & Manner(e1,s1) & Theme(e1,x2) & Actor(e1,x1) & v_put(e1) & n_helmet(x2) & of(x2,x1) & n_male(x1) & n_fireman(x1))