A gathering of many people.
The people are marching for peace.
A gathering does not imply marching.
exists x1 x2.(a_topic(x1) & of(x1,x2) & n_people(x2) & n_quantity(x2) & n_gathering(x1))
exists e1 x1 x2.(n_people(x1) & for(e1,x2) & n_peace(x2) & Actor(e1,x1) & v_march(e1))