a group of people on stage
There are people performing on the stage.
They could just be standing there, not performing.
exists x1 x2 x3.(a_topic(x1) & on(x1,x3) & n_stage(x3) & of(x1,x2) & n_people(x2) & n_group(x1))
exists p1 x1 x4.(n_stage(x4) & exists e1 x2 x3.((x1 = x2) & on(e1,x4) & Actor(e1,x3) & v_perform(e1) & (x2 = x3) & n_people(x2)))