owl:disjointWith is a built-in OWL property with a class description as domain and range.

Each owl:disjointWith statement asserts that the class extensions of the two class descriptions involved have no individuals in common. Like axioms with rdfs:subClassOf, declaring two classes to be disjoint is a partial definition: it imposes a necessary but not sufficient condition on the class.

In order to assert that a set of classes is mutually disjoint, there must be an owl:disjointWith assertion for every pair.


    <rdf:Property rdf:ID="disjointWith">


        <rdfs:domain rdf:resource="#Class"/>

        <rdfs:range rdf:resource="#Class"/>


Example listing




This is a popular example of class disjointness:


    <owl:Class rdf:about="#Man">

        <owl:disjointWith rdf:resource="#Woman"/>



Whether this is actually true is a matter for biologists to decide.

Other information

AXIOM SCHEMA: class description owl:disjointWith  class description


A class axiom may also contain (multiple) owl:disjointWith statements.


The following example shows a common use of class disjointness in subclass hierarchies:


    <owl:Class rdf:about="#MusicDrama">



                <owl:unionOf rdf:parseType="Collection">

                    <owl:Class rdf:about="#Opera"/>

                    <owl:Class rdf:about="#Operetta"/>

                    <owl:Class rdf:about="#Musical"/>






    <owl:Class rdf:about="#Opera">

        <rdfs:subClassOf rdf:resource="#MusicDrama"/>



    <owl:Class rdf:about="#Operetta">

        <rdfs:subClassOf rdf:resource="#MusicDrama"/>

        <owl:disjointWith rdf:resource="#Opera"/>



    <owl:Class rdf:about="#Musical">

        <rdfs:subClassOf rdf:resource="#MusicDrama"/>

            <owl:disjointWith rdf:resource="#Opera"/>

            <owl:disjointWith rdf:resource="#Operetta"/>



Here, owl:disjointWith statements are used together with owl:unionOf in order to define a set of mutually disjoint and complete subclasses of a superclass. In natural language: every MusicDrama is either an opera, an Operetta, or a Musical (the subclass partitioning is complete) and individuals belonging to one subclass, e.g., Opera, cannot belong to another subclass, e.g., Musical (disjoint or non-overlapping subclasses). This is a common modelling notion used in many data-modelling notations.

NOTE: OWL Lite does not allow the use of owl:disjointWith.

Use in ISO 15926