Was M1 executive produced by M2 and M3 and executive produced by a writer of M0 's prequel
SELECT count(*) WHERE {
?x0 ns:film.writer.film ?x1 .
?x1 ns:film.film.sequel M0 .
M1 ns:film.film.executive_produced_by ?x0 .
M1 ns:film.film.executive_produced_by M2 .
M1 ns:film.film.executive_produced_by M3
}