question: What film producer wrote M2 's prequel , executive produced a film , and directed M1
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 a ns:film.producer .
  ?x0 ns:film.director.film M1 .
  ?x0 ns:film.producer.films_executive_produced ?x1 .
  ?x0 ns:film.writer.film ?x2 .
  ?x1 a ns:film.film .
  ?x2 ns:film.film.sequel M2
  }