question: Was a actor employed by a film distributor , employed by M1 , and employed by M2 , M3 , and M4
query: 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.film_distributor
  }