Did M3 and M4 edit a film edited by and directed by M1 and M2
SELECT count(*) WHERE {
?x0 a ns:film.film .
?x0 ns:film.film.directed_by M1 .
?x0 ns:film.film.directed_by M2 .
?x0 ns:film.film.edited_by M1 .
?x0 ns:film.film.edited_by M2 .
M3 ns:film.editor.film ?x0 .
M4 ns:film.editor.film ?x0
}