question: Were M3 and M7 edited by a British editor of M1 and M2 and written by M4 , M5 , and M6
query: SELECT count(*) WHERE {
  ?x0 ns:film.editor.film M1 .
  ?x0 ns:film.editor.film M2 .
  ?x0 ns:people.person.nationality ns:m.07ssc .
  M3 ns:film.film.edited_by ?x0 .
  M3 ns:film.film.written_by M4 .
  M3 ns:film.film.written_by M5 .
  M3 ns:film.film.written_by M6 .
  M7 ns:film.film.edited_by ?x0 .
  M7 ns:film.film.written_by M4 .
  M7 ns:film.film.written_by M5 .
  M7 ns:film.film.written_by M6
  }