Did M2 employ a art director that executive produced M1 and employ M3 and M4
SELECT count(*) WHERE {
?x0 a ns:film.film_art_director .
?x0 ns:film.producer.films_executive_produced M1 .
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
}