Were M1 and M2 written by M0 's sibling 's actor
SELECT count(*) WHERE {
?x0 ns:film.actor.film/ns:film.performance.character ?x1 .
?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 M0 .
FILTER ( ?x1 != M0 ) .
M1 ns:film.film.written_by ?x0 .
M2 ns:film.film.written_by ?x0
}