question: Which film producer did a film distributor employ and M1 , M2 , M3 , M4 , M5 , and M6 employ
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 a ns:film.producer .
  ?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 .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M5 .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M6 .
  ?x1 a ns:film.film_distributor
  }