question: Did M3 employ M4 and employ a screenwriter employed by M1 and M2
query: SELECT count(*) WHERE {
  ?x0 a ns:film.writer .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M1 .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M2 .
  M3 ns:business.employer.employees/ns:business.employment_tenure.person ?x0 .
  M3 ns:business.employer.employees/ns:business.employment_tenure.person M4
  }