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