question: Was M4 's British editor employed by M0 and employed by M1 and M2
query: SELECT count(*) WHERE {
  ?x0 ns:film.editor.film M4 .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M0 .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M1 .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M2 .
  ?x0 ns:people.person.nationality ns:m.07ssc
  }