Five people are sitting inside a building.
There are five people inside that building.
people are sitting inside a building can also be said as  people inside that building.
exists e1 x1 x2.(inside(e1,x2) & n_building(x2) & Actor(e1,x1) & v_sit(e1) & n_people(x1) & card_eq_5(x1))
exists p1 x1 x3.(n_building(x3) & exists x2.((x1 = x2) & inside(x2,x3) & n_people(x2) & card_eq_5(x2)))