Was a person that M2 was written by and M3 was directed by a film editor that directed M4
SELECT count(*) WHERE {
?x0 a ns:film.editor .
?x0 a ns:people.person .
?x0 ns:film.director.film M3 .
?x0 ns:film.director.film M4 .
?x0 ns:film.writer.film M2
}