question: Did M2 and M4 star a character 's sibling , star M3 , and star M0 's writer
query: SELECT count(*) WHERE {
  ?x0 ns:film.writer.film M0 .
  ?x1 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 ?x2 .
  ?x2 a ns:fictional_universe.fictional_character .
  FILTER ( ?x1 != ?x2 ) .
  M2 ns:film.film.starring/ns:film.performance.actor ?x0 .
  M2 ns:film.film.starring/ns:film.performance.actor ?x1 .
  M2 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 ?x1 .
  M4 ns:film.film.starring/ns:film.performance.actor M3
  }