Which actor of M0 and M1 directed a film
SELECT DISTINCT ?x0 WHERE {
?x0 ns:film.actor.film/ns:film.performance.character M0 .
?x0 ns:film.actor.film/ns:film.performance.character M1 .
?x0 ns:film.director.film ?x1 .
?x1 a ns:film.film
}