A group of people are listening to a presentation.
A group at a presentation
They are always near the presentation.
exists e1 x1 x2 x3.(to(e1,x3) & n_presentation(x3) & Actor(e1,x1) & v_listen(e1) & of(x1,x2) & n_people(x2) & n_group(x1))
exists x1 x2.(a_topic(x1) & at(x1,x2) & n_presentation(x2) & n_group(x1))