question: Who founded a company , founded M4 's employer , and was employed by M1 , M2 , and M3
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 a ns:people.person .
  ?x0 ns:organization.organization_founder.organizations_founded ?x1 .
  ?x0 ns:organization.organization_founder.organizations_founded ?x2 .
  ?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 .
  ?x1 ns:business.employer.employees/ns:business.employment_tenure.person M4 .
  ?x2 a ns:business.employer
  }