People sitting and standing talking.
People are talking at a party.
People are not always at a party if they are gathered together and talking.
exists e2 e3 e1 x1 x2.(for(e2,e3) & Actor(e3,x2) & v_talking(e3) & Actor(e2,x2) & v_stand(e2) & n_people(x2) & Actor(e1,x1) & v_sit(e1) & n_people(x1))
exists e1 x1 x2.(at(e1,x2) & n_party(x2) & Actor(e1,x1) & v_talk(e1) & n_people(x1))