question: Did a American art director of M2 and M3 write M0
query: SELECT count(*) WHERE {
  ?x0 ns:film.film_art_director.films_art_directed M2 .
  ?x0 ns:film.film_art_director.films_art_directed M3 .
  ?x0 ns:film.writer.film M0 .
  ?x0 ns:people.person.nationality ns:m.09c7w0
  }