question: Was a screenwriter a actor employed by M2 and employed by M3
query: SELECT count(*) WHERE {
  ?x0 a ns:film.actor .
  ?x0 a ns:film.writer .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M2 .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M3
  }