question: Was a British cinematographer of M2 and M3 a film editor
query: SELECT count(*) WHERE {
  ?x0 a ns:film.editor .
  ?x0 ns:film.cinematographer.film M2 .
  ?x0 ns:film.cinematographer.film M3 .
  ?x0 ns:people.person.nationality ns:m.07ssc
  }