Did M2 employ M3 , employ M4 , and employ a Mexican film director
SELECT count(*) WHERE {
?x0 a ns:film.director .
?x0 ns:people.person.nationality ns:m.0b90_r .
M2 ns:business.employer.employees/ns:business.employment_tenure.person ?x0 .
M2 ns:business.employer.employees/ns:business.employment_tenure.person M3 .
M2 ns:business.employer.employees/ns:business.employment_tenure.person M4
}