question: Did M1 and M4 star M0 's art director 's sibling and star M2 and M3
query: SELECT count(*) WHERE {
  ?x0 ns:people.person.sibling_s/ns:people.sibling_relationship.sibling|ns:fictional_universe.fictional_character.siblings/ns:fictional_universe.sibling_relationship_of_fictional_characters.siblings ?x1 .
  ?x1 ns:film.film_art_director.films_art_directed M0 .
  FILTER ( ?x0 != ?x1 ) .
  M1 ns:film.film.starring/ns:film.performance.actor ?x0 .
  M1 ns:film.film.starring/ns:film.performance.actor M2 .
  M1 ns:film.film.starring/ns:film.performance.actor M3 .
  M4 ns:film.film.starring/ns:film.performance.actor ?x0 .
  M4 ns:film.film.starring/ns:film.performance.actor M2 .
  M4 ns:film.film.starring/ns:film.performance.actor M3
  }