{ "items" : [
    { "id" : "http://dbpedia.org/resource/Empty_set"
      "properties" : {
        "http://www.w3.org/2000/01/rdf-schema#comment" : [ "In mathematics, and more specifically set theory, the empty set is the unique set having no elements; its size or cardinality (count of elements in a set) is zero. Some axiomatic set theories ensure that the empty set exists by including an axiom of empty set; in other theories, its existence can be deduced. Many possible properties of sets are trivially true for the empty set.Null set was once a common synonym for \"empty set\", but is now a technical term in measure theory." ] ,
        "http://xmlns.com/foaf/0.1/depiction" : [ "http://commons.wikimedia.org/wiki/Special:FilePath/Nullset.svg" ] ,
        "http://dbpedia.org/ontology/thumbnail" : [ "http://commons.wikimedia.org/wiki/Special:FilePath/Nullset.svg?width=300"] } } }
