Did M2 and M3 direct a film that a art director executive produced
SELECT count(*) WHERE {
?x0 a ns:film.film .
?x0 ns:film.film.executive_produced_by ?x1 .
?x1 a ns:film.film_art_director .
M2 ns:film.director.film ?x0 .
M3 ns:film.director.film ?x0
}