question: Were M1 and M2 written and edited by a film 's sequel 's director
query: SELECT count(*) WHERE {
  ?x0 ns:film.director.film ?x1 .
  ?x1 ns:film.film.prequel ?x2 .
  ?x2 a ns:film.film .
  M1 ns:film.film.edited_by ?x0 .
  M1 ns:film.film.written_by ?x0 .
  M2 ns:film.film.edited_by ?x0 .
  M2 ns:film.film.written_by ?x0
  }