Was M2 executive produced by M3 and M4 and executive produced by a Canadian screenwriter
SELECT count(*) WHERE {
?x0 a ns:film.writer .
?x0 ns:people.person.nationality ns:m.0d060g .
M2 ns:film.film.executive_produced_by ?x0 .
M2 ns:film.film.executive_produced_by M3 .
M2 ns:film.film.executive_produced_by M4
}