Did a production company employ a employee of M1 and M2
SELECT count(*) WHERE {
?x0 a ns:film.production_company .
?x0 ns:business.employer.employees/ns:business.employment_tenure.person ?x1 .
?x1 ns:people.person.employment_history/ns:business.employment_tenure.company M1 .
?x1 ns:people.person.employment_history/ns:business.employment_tenure.company M2
}