Were M2 and M3 directed , written , and edited by a British film editor
SELECT count(*) WHERE {
?x0 a ns:film.editor .
?x0 ns:people.person.nationality ns:m.07ssc .
M2 ns:film.film.directed_by ?x0 .
M2 ns:film.film.edited_by ?x0 .
M2 ns:film.film.written_by ?x0 .
M3 ns:film.film.directed_by ?x0 .
M3 ns:film.film.edited_by ?x0 .
M3 ns:film.film.written_by ?x0
}