What producer of a film executive produced M0 's prequel
SELECT DISTINCT ?x0 WHERE {
?x0 ns:film.producer.films_executive_produced ?x1 .
?x0 ns:film.producer.film|ns:film.production_company.films ?x2 .
?x1 ns:film.film.sequel M0 .
?x2 a ns:film.film
}