Was M1 's sequel edited by a film 's editor and written by M0
SELECT count(*) WHERE {
?x0 ns:film.film.edited_by ?x1 .
?x0 ns:film.film.prequel M1 .
?x0 ns:film.film.written_by M0 .
?x1 ns:film.editor.film ?x2 .
?x2 a ns:film.film
}