Were M1 and M2 edited by and written by a art director
SELECT count(*) WHERE {
?x0 a ns:film.film_art_director .
M1 ns:film.film.edited_by ?x0 .
M1 ns:film.film.written_by ?x0 .
M2 ns:film.film.edited_by ?x0 .
M2 ns:film.film.written_by ?x0
}