Was a screenwriter a person that M2 , M3 , and M4 were written by
SELECT count(*) WHERE {
?x0 a ns:film.writer .
?x0 a ns:people.person .
?x0 ns:film.writer.film M2 .
?x0 ns:film.writer.film M3 .
?x0 ns:film.writer.film M4
}