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.
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
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