question: Which film was written by M1 and M2 and starred a screenwriter 's child
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 a ns:film.film .
  ?x0 ns:film.film.starring/ns:film.performance.actor ?x1 .
  ?x0 ns:film.film.written_by M1 .
  ?x0 ns:film.film.written_by M2 .
  ?x1 ns:people.person.parents|ns:fictional_universe.fictional_character.parents|ns:organization.organization.parent/ns:organization.organization_relationship.parent ?x2 .
  ?x2 a ns:film.writer
  }