question: Was a employer of M0 and M1 acquired by M2 and M3 , acquired by M4 and M5 , and acquired by M6
query: SELECT count(*) WHERE {
  ?x0 ns:business.employer.employees/ns:business.employment_tenure.person M0 .
  ?x0 ns:business.employer.employees/ns:business.employment_tenure.person M1 .
  ?x0 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M2 .
  ?x0 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M3 .
  ?x0 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M4 .
  ?x0 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M5 .
  ?x0 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M6
  }