Police officers holding back a group of people on the other side.
Police try to stop a stampede.
Holding back a group does not necessarily mean stop a stampede.
exists e1 s1 x1 x2 x3 x4 x5 x6.(-(x6 = x6) & n_side(x6) & a_topic(x1) & on(e1,x6) & a_back(s1) & Manner(e1,s1) & Theme(e1,x4) & Actor(e1,x3) & v_hold(e1) & of(x4,x5) & n_people(x5) & n_group(x4) & (x1 = x3) & n_officer(x1) & of(x1,x2) & n_police(x2))
exists e1 p1 x1.(Topic(e1,p1) & Actor(e1,x1) & v_try(e1) & exists e2 x2.(Theme(e2,x2) & Actor(e2,x1) & v_stop(e2) & n_stampede(x2)) & n_police(x1))