Did M1 employ M2 and M3 and employ a producer of a film 's sequel
SELECT count(*) WHERE {
?x0 ns:film.producer.film|ns:film.production_company.films ?x1 .
?x1 ns:film.film.prequel ?x2 .
?x2 a ns:film.film .
M1 ns:business.employer.employees/ns:business.employment_tenure.person ?x0 .
M1 ns:business.employer.employees/ns:business.employment_tenure.person M2 .
M1 ns:business.employer.employees/ns:business.employment_tenure.person M3
}