Did M2 and M4 star a film producer that edited M1 and star M3
SELECT count(*) WHERE {
?x0 a ns:film.producer .
?x0 ns:film.editor.film M1 .
M2 ns:film.film.starring/ns:film.performance.actor ?x0 .
M2 ns:film.film.starring/ns:film.performance.actor M3 .
M4 ns:film.film.starring/ns:film.performance.actor ?x0 .
M4 ns:film.film.starring/ns:film.performance.actor M3
}