A crowd of people are in a street.
people on a street
A crowd of people can be commonly referred to as people.
exists p1 x1 x2.(exists x3.(in(x1,x3) & n_street(x3)) & of(x1,x2) & n_people(x2) & n_crowd(x1))
exists x1 x2.(a_topic(x1) & on(x1,x2) & n_street(x2) & n_people(x1))