owl:Restriction                                       

Definition

The class owl:Restriction is defined as a subclass of owl:Class. A restriction class should have exactly one triple linking the restriction to a particular property, using the owl:onProperty property.

The restriction class should also have exactly one triple that represents the value constraint c.q. cardinality constraint on the property under consideration, e.g., that the cardinality of the property is exactly 1.

Schema

    <rdfs:Class rdf:ID="Restriction">

        <rdfs:label>Restriction</rdfs:label>

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

    </rdfs:Class>

Example listing

Triple

 

RDF/XML

Property restrictions have the following general form:

    <owl:Restriction>

        <owl:onProperty rdf:resource="(some property)" />

        (precisely one value or cardinality constraint, see below)

    </owl:Restriction>

 

With owl:allValuesFrom:

    <owl:Restriction>

        <owl:onProperty rdf:resource="#hasParent" />

        <owl:allValuesFrom rdf:resource="#Human" />

    </owl:Restriction>

 

With owl:someValuesFrom:

    <owl:Restriction>

        <owl:onProperty rdf:resource="#hasParent" />

        <owl:someValuesFrom rdf:resource="#Physician" />

    </owl:Restriction>

 

With owl:hasValue:

    <owl:Restriction>

        <owl:onProperty rdf:resource="#hasParent" />

        <owl:hasValue rdf:resource="#Clinton" />

    </owl:Restriction>

 

With owl:maxCardinality:

    <owl:Restriction>

        <owl:onProperty rdf:resource="#hasParent" />

        <owl:maxCardinality rdf:datatype="&xsd;nonNegativeInteger">2</owl:maxCardinality>

    </owl:Restriction>

 

With owl:minCardinality:

    <owl:Restriction>

        <owl:onProperty rdf:resource="#hasParent" />

        <owl:minCardinality rdf:datatype="&xsd;nonNegativeInteger">2</owl:minCardinality>

    </owl:Restriction>

 

With owl:cardinality:

    <owl:Restriction>

        <owl:onProperty rdf:resource="#hasParent" />

        <owl:cardinality rdf:datatype="&xsd;nonNegativeInteger">2</owl:cardinality>

    </owl:Restriction>

Other information

A property restriction is a special kind of class description. It describes an anonymous class, namely a class of all individuals that satisfy the restriction. OWL distinguishes two kinds of property restrictions: value constraints and cardinality constraints.

A value constraint puts constraints on the range of the property when applied to this particular class description. For example, we might want to refer to those individuals whose value of the property adjacentTo should be some Region, and then use this within a class axiom, perhaps even a class axiom for Region itself. Note that this is different from rdfs:range, which is applied to all situations in which the property is used.

A cardinality constraint puts constraints on the number of values a property can take, in the context of this particular class description. For example, we might want to say that for a soccer team the hasPlayer property has 11 values. For a basketball team the same property would have only 5 values.

OWL also supports a limited set of constructs for defining global property cardinality, namely owl:FunctionalProperty and owl:InverseFunctionalProperty (see the section on properties).

The class owl:Restriction is defined as a subclass of owl:Class. A restriction class should have exactly one triple linking the restriction to a particular property, using the owl:onProperty property. The restriction class should also have exactly one triple that represents the value constraint c.q. cardinality constraint on the property under consideration, e.g., that the cardinality of the property is exactly 1.

Property restrictions can be applied both to datatype properties (properties for which the value is a data literal) and object properties (properties for which the value is an individual).

Use in ISO 15926