Was a cinematographer employed by M2 's producer , employed by M3 's employer , and employed by M1
SELECT count(*) WHERE {
?x0 a ns:film.cinematographer .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company ?x1 .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company ?x2 .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M1 .
?x1 ns:film.producer.film|ns:film.production_company.films M2 .
?x2 ns:business.employer.employees/ns:business.employment_tenure.person M3
}