question: Which film did M3 edit , M4 edit , M1 write , and M2 write
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 a ns:film.film .
  ?x0 ns:film.film.edited_by M3 .
  ?x0 ns:film.film.edited_by M4 .
  ?x0 ns:film.film.written_by M1 .
  ?x0 ns:film.film.written_by M2
  }