Were M2 , M3 , M4 , M5 , and M6 produced 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.produced_by|ns:film.film.production_companies ?x0 .
M3 ns:film.film.produced_by|ns:film.film.production_companies ?x0 .
M4 ns:film.film.produced_by|ns:film.film.production_companies ?x0 .
M5 ns:film.film.produced_by|ns:film.film.production_companies ?x0 .
M6 ns:film.film.produced_by|ns:film.film.production_companies ?x0
}