OWL

1. OWL Simple Properties

2. Need of Properties
• This world of classes and individuals would be pretty
uninteresting if we could only define taxonomies.
• Properties let us assert general facts about the members
of classes and specific facts about individuals.

3. Defining the Properties
ObjectProperty,
DatatypeProperty,
rdfs:subPropertyOf,
rdfs:domain,
rdfs:range

4. Relation
• A property is a binary relation. Two types of properties
are distinguished:
• Datatype properties, relations between instances of classes and
RDF literals and XML Schema datatypes
• object properties, relations between instances of two classes.

5. Object properties
• When we define a property there are a number of ways to
restrict the relation. The domain and range can be
specified.
• The property can be defined to be a specialization
(subproperty) of an existing property.
<owl:ObjectProperty rdf:ID="madeFromGrape">
<rdfs:domain rdf:resource="#Wine"/>
<rdfs:range rdf:resource="#WineGrape"/>
</owl:ObjectProperty>
<owl:ObjectProperty rdf:ID="course">
<rdfs:domain rdf:resource="#Meal" />
<rdfs:range rdf:resource="#MealCourse" />
</owl:ObjectProperty>

7. Example
<owl:Class rdf:ID="WineDescriptor" />
<owl:Class rdf:ID="WineColor">
<rdfs:subClassOf rdf:resource="#WineDescriptor" />
</owl:Class>
<owl:ObjectProperty rdf:ID="hasWineDescriptor">
<rdfs:domain rdf:resource="#Wine" />
<rdfs:range rdf:resource="#WineDescriptor" />
</owl:ObjectProperty>
<owl:ObjectProperty rdf:ID="hasColor">
<rdfs:subPropertyOf rdf:resource="#hasWineDescriptor" />
<rdfs:range rdf:resource="#WineColor" />
</owl:ObjectProperty>

8. locatedInproperty
<owl:ObjectProperty rdf:ID="locatedIn">
<rdfs:domain rdf:resource="http://www.w3.org/2002/07/owl#Thing" />
<rdfs:range rdf:resource="#Region" />
</owl:ObjectProperty>

9. Datatype Properties
<owl:Class rdf:ID=“AcademicYear" />
<owl:DatatypeProperty rdf:ID="yearValue">
<rdfs:domain rdf:resource="# AcademicYear" />
<rdfs:range rdf:resource="&xsd;positiveInteger"/>
</owl:DatatypeProperty>

10. Properties with Datatype

11. Example: