What did a writer and director of M0 and M1 executive produce
SELECT DISTINCT ?x0 WHERE {
?x0 ns:film.film.executive_produced_by ?x1 .
?x1 ns:film.director.film M0 .
?x1 ns:film.director.film M1 .
?x1 ns:film.writer.film M0 .
?x1 ns:film.writer.film M1
}