Were M3 and M6 produced by a film editor that directed M1 and M2 and directed by M4 and M5
SELECT count(*) WHERE {
?x0 a ns:film.editor .
?x0 ns:film.director.film M1 .
?x0 ns:film.director.film M2 .
M3 ns:film.film.directed_by M4 .
M3 ns:film.film.directed_by M5 .
M3 ns:film.film.produced_by|ns:film.film.production_companies ?x0 .
M6 ns:film.film.directed_by M4 .
M6 ns:film.film.directed_by M5 .
M6 ns:film.film.produced_by|ns:film.film.production_companies ?x0
}