Did a actor edit M1 and M2 and write a prequel of M3
SELECT count(*) WHERE {
?x0 a ns:film.actor .
?x0 ns:film.editor.film M1 .
?x0 ns:film.editor.film M2 .
?x0 ns:film.writer.film ?x1 .
?x1 ns:film.film.sequel M3
}