question: Did a film producer write a film , write M3 , and edit M1 and M2
query: SELECT count(*) WHERE {
  ?x0 a ns:film.producer .
  ?x0 ns:film.editor.film M1 .
  ?x0 ns:film.editor.film M2 .
  ?x0 ns:film.writer.film ?x1 .
  ?x0 ns:film.writer.film M3 .
  ?x1 a ns:film.film
  }