question: Was a prequel of M0 executive produced by a screenwriter , directed by M2 , and written by M1
query: SELECT count(*) WHERE {
  ?x0 ns:film.film.directed_by M2 .
  ?x0 ns:film.film.executive_produced_by ?x1 .
  ?x0 ns:film.film.sequel M0 .
  ?x0 ns:film.film.written_by M1 .
  ?x1 a ns:film.writer
  }