This person is cleaning the building using a green bucket.
The person cleaning is the janitor.
Not all people who clean are a janitor.
exists e1 e2 s1 x1 x2 x3.(n_building(x2) & n_person(x1) & for(e1,e2) & Theme(e2,x3) & Actor(e2,x1) & v_use(e2) & n_bucket(x3) & a_green(s1) & Theme(s1,x3) & Theme(e1,x2) & Actor(e1,x1) & v_clean(e1))
exists p1 x1 x2 x3.(n_janitor(x3) & n_person(x1) & (x1 = x3) & Time(x1,x2) & n_cleaning(x2))