Two workers stand at an entrance.
The workers are janitors.
Janitors can stand anywhere, and non-janitors can stand in entrances as well.
exists e1 x1 x2.(at(e1,x2) & n_entrance(x2) & Actor(e1,x1) & v_stand(e1) & n_worker(x1) & card_eq_2(x1))
exists p1 x1.(n_worker(x1) & exists x2.((x1 = x2) & n_janitor(x2)))