The streets of a big city.
The town is small.
Small and big are different.
exists s1 x1 x2.(n_street(x1) & a_topic(x1) & of(x1,x2) & n_city(x2) & a_big(s1) & Theme(s1,x2))
exists s1 x1.(n_town(x1) & Theme(s1,x1) & a_small(s1))