Was a film producer a person that M2 , M3 , and M4 starred
SELECT count(*) WHERE {
?x0 a ns:film.producer .
?x0 a ns:people.person .
?x0 ns:film.actor.film/ns:film.performance.film M2 .
?x0 ns:film.actor.film/ns:film.performance.film M3 .
?x0 ns:film.actor.film/ns:film.performance.film M4
}