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