question: Were M1 and M6 executive produced by M2 , M3 , M4 , and M5 and executive produced by a star of M0
query: SELECT count(*) WHERE {
  ?x0 ns:film.actor.film/ns:film.performance.film 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 .
  M1 ns:film.film.executive_produced_by M4 .
  M1 ns:film.film.executive_produced_by M5 .
  M6 ns:film.film.executive_produced_by ?x0 .
  M6 ns:film.film.executive_produced_by M2 .
  M6 ns:film.film.executive_produced_by M3 .
  M6 ns:film.film.executive_produced_by M4 .
  M6 ns:film.film.executive_produced_by M5
  }