question: Did M3 star a editor of M0 , M1 , and M2
query: SELECT count(*) WHERE {
  ?x0 ns:film.editor.film M0 .
  ?x0 ns:film.editor.film M1 .
  ?x0 ns:film.editor.film M2 .
  M3 ns:film.film.starring/ns:film.performance.actor ?x0
  }