People stand and talk.
People talking
People are talking together
exists e1 e2 x1 x2.(Actor(e2,x2) & v_talk(e2) & n_people(x2) & Actor(e1,x1) & v_stand(e1) & n_people(x1))
exists e1 x1 x2.(a_topic(x1) & Actor(e1,x2) & v_talk(e1) & (x1 = x2) & n_people(x1))