question: Which child of M6 was employed by M0 and M1 , employed by M2 and M3 , and employed by M4 and M5
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M0 .
  ?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.parents|ns:fictional_universe.fictional_character.parents|ns:organization.organization.parent/ns:organization.organization_relationship.parent M6
  }