question: What actor was a sibling of M1 's writer , director , and producer
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 a ns:film.actor .
  ?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.director.film M1 .
  ?x1 ns:film.producer.film|ns:film.production_company.films M1 .
  ?x1 ns:film.writer.film M1 .
  FILTER ( ?x0 != ?x1 )
  }