Dancers perform on stage.
People performing for a crowd.
Not all dance performances on stage happen in front of a crowd.
exists e1 x1 x2.(on(e1,x2) & n_stage(x2) & Actor(e1,x1) & v_perform(e1) & n_dancer(x1))
exists e1 x1 x2 x3.(a_topic(x1) & for(e1,x3) & n_crowd(x3) & Actor(e1,x2) & v_perform(e1) & (x1 = x2) & n_people(x1))