A group of people are on a stage in front of an audience.
A comedy group is performing on stage.
Not all groups of people on a stage are a comedy group that is performing.
exists p1 x1 x2 x3 x4.(in(p1,x3) & of(x3,x4) & n_audience(x4) & n_front(x3) & exists x5.(on(x1,x5) & n_stage(x5)) & of(x1,x2) & n_people(x2) & n_group(x1))
exists e1 x1 x2 x3.(on(e1,x3) & n_stage(x3) & Actor(e1,x1) & v_perform(e1) & n_group(x1) & of(x1,x2) & n_comedy(x2))