question: Which film producer that founded M2 and M3 and founded M4 , M5 , and M6 was M1 's employee
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 a ns:film.producer .
  ?x0 ns:organization.organization_founder.organizations_founded M2 .
  ?x0 ns:organization.organization_founder.organizations_founded M3 .
  ?x0 ns:organization.organization_founder.organizations_founded M4 .
  ?x0 ns:organization.organization_founder.organizations_founded M5 .
  ?x0 ns:organization.organization_founder.organizations_founded M6 .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M1
  }