Web Ontology Language: OWL - Vrije Universiteit Amsterdam

Web Ontology Language: OWL 7HeaderOWL documents are usually called OWL ontologies, and are RDF documents.So the root element of a OWL ontology is an rdf:RDF element which alsospecifies a number of namespaces. For example:An OWL ontology may start with a collection of assertions for housekeepingpurposes. These assertions are grouped under an owl:Ontology elementwhich contains comments, version control and inclusion of other ontologies.For example:An example OWL ontologyUniversity OntologyThe only of these assertions which has any consequences for the logicalmeaning of the ontology is owl:imports: this lists other ontologies whosecontent is assumed to be part of the current document. ontology. Notice thatwhile namespaces are used for disambiguation purposes, imported ontologiesprovide definitions that can be used. Usually there will be an import elementfor each used namespace, but it is possible to import additional ontologies,for example ontologies that provide definitions without introducing any newnames.Also note that owl:imports is a transitive property: if ontology A importsontology B, and ontology B imports ontology C, then ontology A also importsontology C.Class elementsClasses are defined using a owl:Class element 7 . For example, we can definea class associateProfessor as follows:7 owl:Class is a subclass of rdfs:Class.