question: Did M1 star M0 's actor and star M2 and M3
query: SELECT count(*) WHERE {
  ?x0 ns:film.actor.film/ns:film.performance.character M0 .
  M1 ns:film.film.starring/ns:film.performance.actor ?x0 .
  M1 ns:film.film.starring/ns:film.performance.actor M2 .
  M1 ns:film.film.starring/ns:film.performance.actor M3
  }