question: Did M2 , M4 , and M5 employ M3 and employ a Canadian person
query: SELECT count(*) WHERE {
  ?x0 a ns:people.person .
  ?x0 ns:people.person.nationality ns:m.0d060g .
  M2 ns:business.employer.employees/ns:business.employment_tenure.person ?x0 .
  M2 ns:business.employer.employees/ns:business.employment_tenure.person M3 .
  M4 ns:business.employer.employees/ns:business.employment_tenure.person ?x0 .
  M4 ns:business.employer.employees/ns:business.employment_tenure.person M3 .
  M5 ns:business.employer.employees/ns:business.employment_tenure.person ?x0 .
  M5 ns:business.employer.employees/ns:business.employment_tenure.person M3
  }