What employee of M0 , M1 , M2 , and M3 produced a film
SELECT DISTINCT ?x0 WHERE {
?x0 ns:film.producer.film|ns:film.production_company.films ?x1 .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M0 .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M1 .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M2 .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M3 .
?x1 a ns:film.film
}