People are working in the kitchen.
the people are at a ballet
One group of people is actively working in the kitchen and the other is attending a ballet.
exists e1 x1 x2.(n_kitchen(x2) & in(e1,x2) & Actor(e1,x1) & v_work(e1) & n_people(x1))
exists p1 x1.(n_people(x1) & exists x2.(at(x1,x2) & n_ballet(x2)))