Did a person executive produce M1 , M2 , and M3 and executive produce M4 's prequel
SELECT count(*) 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 ns:film.film.sequel M4
}