Was a director and writer of M1 , M2 , and M3 a film producer
SELECT count(*) WHERE {
?x0 a ns:film.producer .
?x0 ns:film.director.film M1 .
?x0 ns:film.director.film M2 .
?x0 ns:film.director.film M3 .
?x0 ns:film.writer.film M1 .
?x0 ns:film.writer.film M2 .
?x0 ns:film.writer.film M3
}