owl:minCardinality                               

Definition

The cardinality constraint owl:minCardinality is a built-in OWL property that links a restriction class to a data value belonging to the value space of the XML Schema datatype nonNegativeInteger.

A restriction containing an owl:minCardinality constraint describes a class of all individuals that have at least N semantically distinct values (individuals or data values) for the property concerned, where N is the value of the cardinality constraint.

Syntactically, the cardinality constraint is represented as an RDF property element with the corresponding rdf:datatype attribute.

Schema

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

        <rdfs:label>minCardinality</rdfs:label>

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

        <rdfs:range rdf:resource="&xsd;nonNegativeInteger"/>

    </rdf:Property>

Example listing

Triple

 

RDF/XML

The following example describes a class of individuals that have at least two parents:

    <owl:Restriction>

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

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

    </owl:Restriction>

Other information

In OWL, like in RDF, it is assumed that any instance of a class may have an arbitrary number (zero or more) of values for a particular property. To make a property required (at least one), to allow only a specific number of values for that property, or to insist that a property must not occur, cardinality constraints can be used. OWL provides three constructs for restricting the cardinality of properties locally within a class context.

NOTE: OWL Lite includes the use of all three types of cardinality constraints, but only when used with the values "0" or "1".

Note that an owl:minCardinality of one or more means that all instances of the class must have a value for the property

Use in ISO 15926