Was a film 's prequel 's producer 's sibling M1
SELECT count(*) WHERE {
?x0 ns:film.producer.film|ns:film.production_company.films ?x1 .
?x1 ns:film.film.sequel ?x2 .
?x2 a ns:film.film .
FILTER ( M1 != ?x0 ) .
M1 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 ?x0
}