Created on March 12, 2013, 12:57 a.m. by Hevok & updated on March 12, 2013, 12:58 a.m. by Hevok
A number Restriction can be combined with a Range Restriction which yields a Qualified Number Restriction.
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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.
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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.
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OWL enables Class Constructors with number restrictions on properties connected with a Range constraint
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E.g. Examination ⊑ ≥2 hasExaminer.Professor
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:Examination a owl:Class;
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rdfs:subClassOf [
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a owl:Restriction ;
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owl:onProperty :hasExaminer ;
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owl:minQualifiedCardinality "2"^^xsd:nonNegativeInteger;
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owl:onClass :Professor ] .
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* owl:maxQualifiedCardinality
, owl:minQualifiedCardinality
, QualifiedCardinality
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