Was M2 executive produced by M3 and produced by a Mexican person
SELECT count(*) WHERE {
?x0 a ns:people.person .
?x0 ns:people.person.nationality ns:m.0b90_r .
M2 ns:film.film.executive_produced_by M3 .
M2 ns:film.film.produced_by|ns:film.film.production_companies ?x0
}