Was M2 written by M3 and M4 and written by a Mexican art director of M1
SELECT count(*) WHERE {
?x0 ns:film.film_art_director.films_art_directed M1 .
?x0 ns:people.person.nationality ns:m.0b90_r .
M2 ns:film.film.written_by ?x0 .
M2 ns:film.film.written_by M3 .
M2 ns:film.film.written_by M4
}