question: Was M1 executive produced by M2 , executive produced by M3 and M4 , and executive produced by a film editor
query: SELECT count(*) WHERE {
  ?x0 a ns:film.editor .
  M1 ns:film.film.executive_produced_by ?x0 .
  M1 ns:film.film.executive_produced_by M2 .
  M1 ns:film.film.executive_produced_by M3 .
  M1 ns:film.film.executive_produced_by M4
  }