Did a actor produce a film and write M1 's prequel
SELECT count(*) WHERE {
?x0 a ns:film.actor .
?x0 ns:film.producer.film|ns:film.production_company.films ?x1 .
?x0 ns:film.writer.film ?x2 .
?x1 a ns:film.film .
?x2 ns:film.film.sequel M1
}