A rainbow over buildings.
A rainbow is over buildings
A rainbow over buildings implies that the rainbow is over buildings.
exists x1 x2.(a_topic(x1) & over(x1,x2) & n_building(x2) & n_rainbow(x1))
exists p1 x1.(exists x2.(over(x1,x2) & n_building(x2)) & n_rainbow(x1))