These people are demonstrating for their leader.
Some people, for their leader, are doing something.
People are doing demonstrating so they are in fact doing something.
exists e1 x1 x2.(n_leader(x2) & of(x2,x1) & n_thing(x1) & n_people(x1) & for(e1,x2) & Actor(e1,x1) & v_demonstrate(e1))
exists e1 x1 x2 x3.(for(e1,x3) & n_leader(x3) & of(x3,x1) & n_thing(x1) & Theme(e1,x2) & Actor(e1,x1) & v_do(e1) & n_thing(x2) & n_people(x1))