There are buildings in the background.
The buildings are in the city.
Just because there are buildings does not mean they are part of a city.
exists p1 x1 x3.(n_background(x3) & exists x2.((x1 = x2) & in(x2,x3) & n_building(x2)))
exists p1 x1 x2.(n_city(x2) & n_building(x1) & in(x1,x2))