Was M1 executive produced by M2 , executive produced by M3 , and written by a film editor
SELECT count(*) WHERE {
?x0 a ns:film.editor .
M1 ns:film.film.executive_produced_by M2 .
M1 ns:film.film.executive_produced_by M3 .
M1 ns:film.film.written_by ?x0
}