Was a costume designer 's employer a employer of a writer of M1
SELECT count(*) WHERE {
?x0 ns:business.employer.employees/ns:business.employment_tenure.person ?x1 .
?x0 ns:business.employer.employees/ns:business.employment_tenure.person ?x2 .
?x1 a ns:film.film_costumer_designer .
?x2 ns:film.writer.film M1
}