question: Was M2 produced by a person that M1 was executive produced by and starred
query: SELECT count(*) WHERE {
  ?x0 a ns:people.person .
  ?x0 ns:film.actor.film/ns:film.performance.film M1 .
  ?x0 ns:film.producer.films_executive_produced M1 .
  M2 ns:film.film.produced_by|ns:film.film.production_companies ?x0
  }