People are gathered at a business conference.
There are people at the business conference.
"There are people at" is a rephrasing of "People are gathered at"
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 p1 x1 x2 x3.(n_conference(x2) & of(x2,x3) & n_business(x3) & at(p1,x2) & exists x4.((x1 = x4) & n_people(x4)))