Was a film 's prequel 's editor and executive producer employed by M0 and employed by M1 , M2 , and M3
SELECT count(*) WHERE {
?x0 ns:film.editor.film ?x1 .
?x0 ns:film.producer.films_executive_produced ?x1 .
?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.employment_history/ns:business.employment_tenure.company M3 .
?x1 ns:film.film.sequel ?x2 .
?x2 a ns:film.film
}