Was M2 directed by a art director , directed by a person , and edited by M3
SELECT count(*) WHERE {
?x0 a ns:people.person .
?x1 a ns:film.film_art_director .
M2 ns:film.film.directed_by ?x0 .
M2 ns:film.film.directed_by ?x1 .
M2 ns:film.film.edited_by M3
}