Did M1 , M2 , and M3 employ a cinematographer of M0
SELECT count(*) WHERE {
?x0 ns:film.cinematographer.film M0 .
M1 ns:business.employer.employees/ns:business.employment_tenure.person ?x0 .
M2 ns:business.employer.employees/ns:business.employment_tenure.person ?x0 .
M3 ns:business.employer.employees/ns:business.employment_tenure.person ?x0
}