question: Who wrote M1 and M2 , wrote M3 , M4 , and M5 , and directed M6 and M7
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 a ns:people.person .
  ?x0 ns:film.director.film M6 .
  ?x0 ns:film.director.film M7 .
  ?x0 ns:film.writer.film M1 .
  ?x0 ns:film.writer.film M2 .
  ?x0 ns:film.writer.film M3 .
  ?x0 ns:film.writer.film M4 .
  ?x0 ns:film.writer.film M5
  }