Street performers being watched by an interested crowd.
The street is empty.
If there is an interested crowd watching, the street would not be empty
exists e1 s1 x1 x2 x3 x4.(a_topic(x1) & Actor(e1,x4) & n_crowd(x4) & a_interested(s1) & Theme(s1,x4) & Theme(e1,x3) & v_watch(e1) & (x1 = x3) & n_performer(x1) & (x1 = x2) & ne_per_street(x2))
exists s1 x1.(n_street(x1) & Theme(s1,x1) & a_empty(s1))