A window washer is cleaning the bookstore windows.
The person is spraying a cleaning solution on the window.
A window washer can get their cleaning solution on a window by means other than spraying it.  They could apply it with a sponge, for instance.
exists e1 x1 x2 x3.(Theme(e1,x2) & Actor(e1,x1) & v_clean(e1) & n_window(x2) & n_window(x2) & of(x2,x3) & n_bookstore(x3) & n_washer(x1) & of(x1,x2))
exists e1 x1 x2 x3 x4.(n_window(x4) & n_person(x1) & Theme(e1,x2) & Actor(e1,x1) & v_spray(e1) & on(x2,x4) & n_solution(x2) & of(x2,x3) & n_cleaning(x3))