question: Did M5 employ a Canadian writer of M0 , M1 , M2 , and M3 and employ M6 and M7
query: SELECT count(*) WHERE {
  ?x0 ns:film.writer.film M0 .
  ?x0 ns:film.writer.film M1 .
  ?x0 ns:film.writer.film M2 .
  ?x0 ns:film.writer.film M3 .
  ?x0 ns:people.person.nationality ns:m.0d060g .
  M5 ns:business.employer.employees/ns:business.employment_tenure.person ?x0 .
  M5 ns:business.employer.employees/ns:business.employment_tenure.person M6 .
  M5 ns:business.employer.employees/ns:business.employment_tenure.person M7
  }