Was a actor employed by M1 , M2 , and M3 , employed by M4 , and employed by a film producer
SELECT count(*) WHERE {
?x0 a ns:film.actor .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company ?x1 .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M1 .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M2 .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M3 .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M4 .
?x1 a ns:film.producer
}