question: Was a film 's prequel executive produced by M0 and directed by a film director
query: SELECT count(*) WHERE {
  ?x0 ns:film.film.directed_by ?x1 .
  ?x0 ns:film.film.executive_produced_by M0 .
  ?x0 ns:film.film.sequel ?x2 .
  ?x1 a ns:film.director .
  ?x2 a ns:film.film
  }