Did M1 and M2 edit a prequel and sequel of a film
SELECT count(*) WHERE {
?x0 ns:film.film.prequel ?x1 .
?x0 ns:film.film.sequel ?x1 .
?x1 a ns:film.film .
M1 ns:film.editor.film ?x0 .
M2 ns:film.editor.film ?x0
}