Did M1 star M0 's prequel 's star and star M2
SELECT count(*) WHERE {
?x0 ns:film.actor.film/ns:film.performance.film ?x1 .
?x1 ns:film.film.sequel M0 .
M1 ns:film.film.starring/ns:film.performance.actor ?x0 .
M1 ns:film.film.starring/ns:film.performance.actor M2
}