owl2.0 primer part02

2010.07.22OWL 2.0 Primer

OWL2.0 primer 2

Protege4.1_beta

OWL2.0 primer 3

Contents

Advanced Class Relationships Advanced Use of Properties Advanced Use of Datatypes

OWL2.0 primer 4

Complex Classes

Woman

EquivalentClasses(

:Mother

ObjectIntersectionOf( :Woman :Parent )

)

ParentMother

OWL2.0 primer 5

Complex Classes

EquivalentClasses(

:Parent

ObjectUnionOf( :Mother :Father )

)

Mother FatherParent

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Complex Classes

EquivalentClasses(

:ChildlessPerson

ObjectIntersectionOf(

:Person

ObjectComplementOf( :Parent )

)

Parent

OWL2.0 primer 7

Property Restrictions

Existential quantification

Every instance of Parent has at least one children

EquivalentClasses(

:Parent

ObjectSomeValuesFrom ( :hasChild :Person )

)

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Property Restrictions

Universal quantification

A Happy person exactly if all their children are Happy person.

EquivalentClasses(

:HappyPerson

ObjectAllValuesFrom ( :hasChild :HappyPerson )

)

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Property Restrictions

Property restrictions can also be used to describe classes of individuals that are related to one par-ticular individual.

EquivalentClasses(

:JohnsChildren

ObjectHasValue ( :hasParent :John )

)

OWL2.0 primer 10

Property Restrictions

As a special case of individuals being interlinked by properties, an individual might be linked to it-self.

EquivalentClasses(

:NarcisticPerson

ObjectHasSelf ( :loves )

)

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John has at most four children who are them-selves parents

Property Restrictions

ClassAssertion(

ObjectMaxCardinality( 4 :hasChild :Parent )

:John)

OWL2.0 primer 12

John has at least two children who are parents

Property Restrictions

ClassAssertion(

ObjectMinCardinality( 2 :hasChild :Parent )

:John)

John has three children who are parents

ClassAssertion(

ObjectExactCardinality( 3 :hasChild :Parent )

:John)

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Enumeration of Individuals

Bill, John and Mary are the only members of MyBirthdayGuests.

EquivalentClasses(:MyBirthdayGuestsObjectOneOf( :Bill :John :Mary )

)

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Contents

Advanced Class Relationships Advanced Use of Properties Advanced Use of Datatypes

OWL2.0 primer 15

Property Characteristics

A is linked to B by hasChild property, B and A also interlinked by the hasParent property.

InverseObjectProperties( :hasParent :hasChild )

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Property Characteristics

In some cases, a property and its inverse coincide, or in other words, the direction of a property doesn’t matter.

SymmetricObjectProperty( :hasSpouse )

A property can also be asymmetric meaning that if it connects A with B it never connects B with A.

AsymmetricObjectProperty( :hasChild )

OWL2.0 primer 17

Property Characteristics

Two properties are disjoint if there are no two indi-viduals that are interlinked by both properties.

DisjointObjectProperties( :hasParent :hasSpouse )

OWL2.0 primer 18

Property Characteristics

Properties can be reflexive: such a property re-lates everything to itself.

ReflexiveObjectProperty( :hasRelative )

Properties can also be irreflexive, meaning that no individual can be related to itself by such a role.

IrreflexiveObjectProperty( :parentOf )

OWL2.0 primer 19

Property Characteristics

Every individual can be linked by the hasHusband property to at most one other individual.

FunctionalObjectProperty( :hasHusband)

A transitive property interlinks two individuals A and C whenever it interlinks A with B and B with C for some individual B.

TransitiveObjectProperty( :hasAncestor )

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Property Chains

A hasGrandparent C if A hasParent B, B hasPar-ent C

SubObjectPropertyOf(

ObjectPropertyChain( :hasParent :hasParent)

:hasGrandparent

)

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Keys

Each named instance of the class expression is uniquely identified by the set of values which these properties attain in relation to the instance.

HasKey( :Person () ( :hasSSN ) )

OWL2.0 primer 22

Contents

Advanced Class Relationships Advanced Use of Properties Advanced Use of Datatypes

OWL2.0 primer 23

Advanced Use of Datatypes

It is possible to express and define new datatypes by constraining or combining to.

Define a new datatype for a person’s age by con-straining the datatype integer to values between 0 and 150.

DatatypeDefinition(

:personAge

DatatypeRestriction( xsd:integer

xsd:minInclusive “0”^^xsd:integer

xsd:maxInclusive “150”^^xsd:integer

)

)

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Advanced Use of Datatypes

Datatypes can be combined just like classes by complement, intersection and union.

Define the datatype majorAge by excluding all data values of minorAge from personAge.

DatatypeDefinition(

:majorAge

DatatypeIntersectionOf(

:personAge

DateComplementOf( :minorAge )

)

)

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Advanced Use of Datatypes

A new datatype can be generated by just enumer-ating the data values it contains.

DatatypeDefinition(

:toddlerAge

DataOneOf( “1”^^xsd:integer “2”^^xsd:integer )

)

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Advanced Use of Datatypes

We can express person has only one age by char-acterizing the hasAge datatype property as func-tional.

FunctionalDataProperty( :hasAge )

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Advanced Use of Datatypes

New Classes can be defined by restrictions on datatype properties.

SubClassOf(

:Teenager

DataSomeValuesFrom( :hasAge

DatatypeRestriction( :xsd:integer

xsd:minExclusive “12”^^xsd:integer

xsd:maxInclusive “19”^^xsd:integer

)

)

)

OWL2.0 primer 28

Q & A