Did a Mexican person executive produce M1 , M2 , M3 , and M4
SELECT count(*) WHERE {
?x0 a ns:people.person .
?x0 ns:film.producer.films_executive_produced M1 .
?x0 ns:film.producer.films_executive_produced M2 .
?x0 ns:film.producer.films_executive_produced M3 .
?x0 ns:film.producer.films_executive_produced M4 .
?x0 ns:people.person.nationality ns:m.0b90_r
}