question: Did a film editor write M1 , M2 , M3 , M4 , M5 , M6 , and M7
query: SELECT count(*) WHERE {
  ?x0 a ns:film.editor .
  ?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 .
  ?x0 ns:film.writer.film M6 .
  ?x0 ns:film.writer.film M7
  }