Question: What is the most populated city of the country where the Mexican Coat of Arms is the country's Coat of Arms?
Answer(s):
answer: Mexico City

SPARQL query:
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
FILTER (?x != ?c)
FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
?c ns:symbols.coat_of_arms_bearer.coat_of_arms_used ?k .
?k ns:symbols.armorial_grant.coat_of_arms ns:m.02wkvz . 
?c ns:location.location.contains ?x .
?x ns:common.topic.notable_types ns:m.01m9 .
?x ns:topic_server.population_number ?sk0 .
}
ORDER BY DESC(xsd:float(?sk0))
LIMIT 1