People standing on a street.
The street is empty.
When people are standing on a street, the street can not be empty.
exists e1 x1 x2 x3.(a_topic(x1) & on(e1,x3) & n_street(x3) & Actor(e1,x2) & v_stand(e1) & (x1 = x2) & n_people(x1))
exists s1 x1.(n_street(x1) & Theme(s1,x1) & a_empty(s1))