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