question: Was M2 edited by a Canadian director of M1 and executive produced by M3 and M4
query: SELECT count(*) WHERE {
  ?x0 ns:film.director.film M1 .
  ?x0 ns:people.person.nationality ns:m.0d060g .
  M2 ns:film.film.edited_by ?x0 .
  M2 ns:film.film.executive_produced_by M3 .
  M2 ns:film.film.executive_produced_by M4
  }