question: Did M1 and M2 executive produce a prequel of M0 's prequel
query: SELECT count(*) WHERE {
  ?x0 ns:film.film.sequel ?x1 .
  ?x1 ns:film.film.sequel M0 .
  M1 ns:film.producer.films_executive_produced ?x0 .
  M2 ns:film.producer.films_executive_produced ?x0
  }