Did M2 direct M4 , direct a film written by M1 , and write M3
SELECT count(*) WHERE {
?x0 a ns:film.film .
?x0 ns:film.film.written_by M1 .
M2 ns:film.director.film ?x0 .
M2 ns:film.director.film M4 .
M2 ns:film.writer.film M3
}