Were M2 and M3 founded by a writer and editor of M1 and founded by a actor
SELECT count(*) WHERE {
?x0 a ns:film.actor .
?x1 ns:film.editor.film M1 .
?x1 ns:film.writer.film M1 .
M2 ns:organization.organization.founders ?x0 .
M2 ns:organization.organization.founders ?x1 .
M3 ns:organization.organization.founders ?x0 .
M3 ns:organization.organization.founders ?x1
}