question: Was M1 employed by M2 and M3 , employed by M0 's employer , and employed by M4 , M5 , and M6
query: SELECT count(*) WHERE {
  ?x0 ns:business.employer.employees/ns:business.employment_tenure.person M0 .
  M1 ns:people.person.employment_history/ns:business.employment_tenure.company ?x0 .
  M1 ns:people.person.employment_history/ns:business.employment_tenure.company M2 .
  M1 ns:people.person.employment_history/ns:business.employment_tenure.company M3 .
  M1 ns:people.person.employment_history/ns:business.employment_tenure.company M4 .
  M1 ns:people.person.employment_history/ns:business.employment_tenure.company M5 .
  M1 ns:people.person.employment_history/ns:business.employment_tenure.company M6
  }