question: Was M1 a actor that M0 's prequel was written by and M3 starred
query: SELECT count(*) WHERE {
  ?x0 ns:film.film.sequel M0 .
  M1 a ns:film.actor .
  M1 ns:film.actor.film/ns:film.performance.film M3 .
  M1 ns:film.writer.film ?x0
  }