Were M3 and M4 edited by and written by a film editor that wrote M1 and M2
SELECT count(*) WHERE {
?x0 a ns:film.editor .
?x0 ns:film.writer.film M1 .
?x0 ns:film.writer.film M2 .
M3 ns:film.film.edited_by ?x0 .
M3 ns:film.film.written_by ?x0 .
M4 ns:film.film.edited_by ?x0 .
M4 ns:film.film.written_by ?x0
}