Question: Is Lake Baikal bigger than the Great Bear Lake?
SPARQL query:
PREFIX res: <http://dbpedia.org/resource/>
PREFIX onto: <http://dbpedia.org/ontology/> 
ASK
WHERE {  
        res:Lake_Baikal onto:areaTotal ?a1 . 
        res:Great_Bear_Lake onto:areaTotal ?a2 .
        FILTER (?a1 > ?a2)
}