Did a art director write M1 and M2 and direct a prequel of M3
SELECT count(*) WHERE {
?x0 a ns:film.film_art_director .
?x0 ns:film.director.film ?x1 .
?x0 ns:film.writer.film M1 .
?x0 ns:film.writer.film M2 .
?x1 ns:film.film.sequel M3
}