question: What Canadian writer of M0 , M1 , and M2 was M3 's employee and founder
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 ns:film.writer.film M0 .
  ?x0 ns:film.writer.film M1 .
  ?x0 ns:film.writer.film M2 .
  ?x0 ns:organization.organization_founder.organizations_founded M3 .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M3 .
  ?x0 ns:people.person.nationality ns:m.0d060g
  }