question: Was M0 's prequel directed by a art director and directed by M1 and M2
query: SELECT count(*) WHERE {
  ?x0 ns:film.film.directed_by ?x1 .
  ?x0 ns:film.film.directed_by M1 .
  ?x0 ns:film.film.directed_by M2 .
  ?x0 ns:film.film.sequel M0 .
  ?x1 a ns:film.film_art_director
  }