Was M1 a Mexican spouse of a person
SELECT count(*) WHERE {
?x0 a ns:people.person .
FILTER ( M1 != ?x0 ) .
M1 ns:people.person.nationality ns:m.0b90_r .
M1 ns:people.person.spouse_s/ns:people.marriage.spouse|ns:fictional_universe.fictional_character.married_to/ns:fictional_universe.marriage_of_fictional_characters.spouses ?x0
}