Were M1 and M3 employed by M2 , employed by a film distributor , and employed by a film distributor
SELECT count(*) WHERE {
?x0 a ns:film.film_distributor .
?x1 a ns:film.film_distributor .
M1 ns:people.person.employment_history/ns:business.employment_tenure.company ?x0 .
M1 ns:people.person.employment_history/ns:business.employment_tenure.company ?x1 .
M1 ns:people.person.employment_history/ns:business.employment_tenure.company M2 .
M3 ns:people.person.employment_history/ns:business.employment_tenure.company ?x0 .
M3 ns:people.person.employment_history/ns:business.employment_tenure.company ?x1 .
M3 ns:people.person.employment_history/ns:business.employment_tenure.company M2
}