question: Was M1 directed by M4 , edited by M3 , written by M2 , and edited by a person
query: SELECT count(*) WHERE {
  ?x0 a ns:people.person .
  M1 ns:film.film.directed_by M4 .
  M1 ns:film.film.edited_by ?x0 .
  M1 ns:film.film.edited_by M3 .
  M1 ns:film.film.written_by M2
  }