Who wrote M1 , wrote M2 and M3 , and executive produced a film
SELECT DISTINCT ?x0 WHERE {
?x0 a ns:people.person .
?x0 ns:film.producer.films_executive_produced ?x1 .
?x0 ns:film.writer.film M1 .
?x0 ns:film.writer.film M2 .
?x0 ns:film.writer.film M3 .
?x1 a ns:film.film
}