Was M3 a prequel of a film whose Canadian writer edited M1
SELECT count(*) WHERE {
?x0 a ns:film.film .
?x0 ns:film.film.written_by ?x1 .
?x1 ns:film.editor.film M1 .
?x1 ns:people.person.nationality ns:m.0d060g .
M3 ns:film.film.sequel ?x0
}