Were M1 and M3 employed by M2 and employed by a distributor of M0 's prequel
SELECT count(*) WHERE {
?x0 ns:film.film_distributor.films_distributed/ns:film.film_film_distributor_relationship.film ?x1 .
?x1 ns:film.film.sequel M0 .
M1 ns:people.person.employment_history/ns:business.employment_tenure.company ?x0 .
M1 ns:people.person.employment_history/ns:business.employment_tenure.company M2 .
M3 ns:people.person.employment_history/ns:business.employment_tenure.company ?x0 .
M3 ns:people.person.employment_history/ns:business.employment_tenure.company M2
}