question: Did a Mexican screenwriter produce M6 , produce M7 , and write M1 , M2 , M3 , and M4
query: SELECT count(*) WHERE {
  ?x0 a ns:film.writer .
  ?x0 ns:film.producer.film|ns:film.production_company.films M6 .
  ?x0 ns:film.producer.film|ns:film.production_company.films M7 .
  ?x0 ns:film.writer.film M1 .
  ?x0 ns:film.writer.film M2 .
  ?x0 ns:film.writer.film M3 .
  ?x0 ns:film.writer.film M4 .
  ?x0 ns:people.person.nationality ns:m.0b90_r
  }