question: Who distributed M1 , M2 , and M3 , distributed M4 , and distributed a film
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 a ns:people.person .
  ?x0 ns:film.film_distributor.films_distributed/ns:film.film_film_distributor_relationship.film ?x1 .
  ?x0 ns:film.film_distributor.films_distributed/ns:film.film_film_distributor_relationship.film M1 .
  ?x0 ns:film.film_distributor.films_distributed/ns:film.film_film_distributor_relationship.film M2 .
  ?x0 ns:film.film_distributor.films_distributed/ns:film.film_film_distributor_relationship.film M3 .
  ?x0 ns:film.film_distributor.films_distributed/ns:film.film_film_distributor_relationship.film M4 .
  ?x1 a ns:film.film
  }