owl:Nothing                                           

Definition

Two OWL class identifiers are predefined, namely the classes owl:Thing and owl:Nothing.

The class extension of owl:Thing is the set of all individuals. The class extension of owl:Nothing is the empty set. Consequently, every OWL class is a subclass of owl:Thing and owl:Nothing is a subclass of every class.

Schema

    <Class rdf:ID="Nothing">

        <rdfs:label>Nothing</rdfs:label>

        <complementOf rdf:resource="#Thing"/>

    </Class>

Example listing

Triple

    _:a   rdf:type   owl:Nothing .

    _:a   rdf:type   owl:Class .

    _:a   owl:oneOf   rdf:nil .

    _:a   owl:equivalentClass   owl:Nothing .

RDF/XML

    <rdf:RDF

        xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"     

        xmlns:owl="http://www.w3.org/2002/07/owl#"

        xml:base="http://www.w3.org/2002/03owlt/Nothing/inconsistent001" >

        <owl:Nothing/>

    </rdf:RDF>

Other information

The class with identifier owl:Nothing is the empty class. It is part of OWL Lite.

Use in ISO 15926