question: Was a actor employed by M1 and M2 and employed by a company
query: SELECT count(*) WHERE {
  ?x0 a ns:film.actor .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company ?x1 .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M1 .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M2 .
  ?x1 a ns:business.employer
  }