What did M0 write , M1 write , M2 direct , and M3 direct
SELECT DISTINCT ?x0 WHERE {
?x0 ns:film.film.directed_by M2 .
?x0 ns:film.film.directed_by M3 .
?x0 ns:film.film.written_by M0 .
?x0 ns:film.film.written_by M1
}