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