People are gathered at a business conference.
A group of people.
Business conference always has group of people.
exists e1 x1 x2 x3.(at(e1,x2) & n_conference(x2) & of(x2,x3) & n_business(x3) & Theme(e1,x1) & v_gather(e1) & n_people(x1))
exists x1 x2.(a_topic(x1) & of(x1,x2) & n_people(x2) & n_group(x1))