question: Was a Mexican film editor that M2 and M3 were directed by a film director
query: SELECT count(*) WHERE {
  ?x0 a ns:film.editor .
  ?x0 ns:film.director.film M2 .
  ?x0 ns:film.director.film M3 .
  ?x0 ns:people.person.nationality ns:m.0b90_r
  }