Was a screenwriter employed by a film distributor and employed by M1 , M2 , M3 , and M4
SELECT count(*) WHERE {
?x0 a ns:film.writer .
?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.film_distributor
}