Qualified Number Restriction

Created on March 12, 2013, 12:57 a.m. by Hevok & updated by Hevok on May 2, 2013, 5:34 p.m.

A number Restriction can be combined with a Range Restriction which yields a Qualified Number Restriction.

For example one can define a Class Examination which is a Subclass of something which has at least two Professors as examiners. In OWL it is stated by saying that Examination is a Class which is a Subclass of a, owl:Restriction. The Restriction is on the Property hasExaminer. Then one does the number restriction but as Qualified number restriction, which is here are lower bound, i.e. at least two Examiners. So one says owl:minQualifiedCardinality should be at least 2 as a `nonNegativeInteger from the XML Schema Definition. Because it is a Qualified Number Restriction one has to specify the class on which it applies as a Range for that Property, which is here owl:onClass Professor.

So one can define a Qualified Number Restriction to an exact number or an lower/upper bound and on a specific Range. This allows to define a lower, upper or exact value that has to be fulfilled.

  • OWL enables Class Constructors with number restrictions on properties connected with a Range constraint
  • E.g. Examination ⊑ ≥2 hasExaminer.Professor

    :Examination a owl:Class;
        rdfs:subClassOf [
            a owl:Restriction ;
            owl:onProperty :hasExaminer ;
            owl:minQualifiedCardinality "2"^^xsd:nonNegativeInteger;
            owl:onClass :Professor ] .
  • owl:maxQualifiedCardinality, owl:minQualifiedCardinality, QualifiedCardinality


Tags: relationships, ontology, property, number, quantification
Categories: Concept
Parent: Property Restriction

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