question: Was a art director that M2 , M3 , and M4 starred a film director
query: SELECT count(*) WHERE {
  ?x0 a ns:film.director .
  ?x0 a ns:film.film_art_director .
  ?x0 ns:film.actor.film/ns:film.performance.film M2 .
  ?x0 ns:film.actor.film/ns:film.performance.film M3 .
  ?x0 ns:film.actor.film/ns:film.performance.film M4
  }