question: What was a film that M4 , M5 , and M6 wrote and M1 , M2 , and M3 executive produced
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 a ns:film.film .
  ?x0 ns:film.film.executive_produced_by M1 .
  ?x0 ns:film.film.executive_produced_by M2 .
  ?x0 ns:film.film.executive_produced_by M3 .
  ?x0 ns:film.film.written_by M4 .
  ?x0 ns:film.film.written_by M5 .
  ?x0 ns:film.film.written_by M6
  }