question: Which actor that M4 , M5 , and M6 were founded by was employed by M1 and employed by M2 and M3
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 a ns:film.actor .
  ?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 .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M2 .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M3
  }