Setting Up an OWL DL Ontology
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Setting Up an OWL DL Ontology |
Setting up an OWL DL ontology in SemanticWorks involves the same steps as with an OWL Lite ontology. These are:
| 1. | Creating a new ontology document. |
| 2. | Setting the language level (OWL DL in this case). |
| 3. | Declaring namespaces. |
| 4. | Saving the file with a .rdf or .owl extension. |
In this section, you will go through these steps in sequence.
Creating a new ontology document
To create a new ontology document, click the New toolbar icon 
or select the command File | New.
Setting the ontology language level
In the RDF/OWL Level combo box in the toolbar, select OWL DL. Alternatively, in the RDF/OWL menu, select RDF/OWL Level, and then OWL DL.
Declaring namespaces
For the OWL DL ontology you are creating you need to declare three namespaces:
| • | XML Schema namespace: http://www.w3.org/2001/XMLSchema#, to be declared with a prefix of xsd. |
| • | A namespace for the Altova document vocabulary: http://www.altova.com/ontologies/document#, with a prefix of doc. |
| • | The Dublin Core namespace for defining document metadata: http://purl.org/dc/elements/1.1/, with a prefix of dc. |
Namespaces are declared in the URIref Prefixes dialog (menu item Tools | URIref Prefixes) shown below. Add a line for each required namespace using the Add button. Then enter the namespace and its prefix.
Note:
| • | It is important to declare namespaces at the very outset. This ensures that URIref prefixes used in the names of ontology items are correctly expanded to the relevant namespaces when a new ontology item is created. If a namespace has not been declared, then the URIref prefix associated with that namespace, when used in the name of an item, will not be expanded to that namespace. |
| • | The expansion of a URIref prefix to a namespace will not take place if: (i) the namespace is declared subsequent to the creation of an item using that URIref prefix; or (ii) if the ontology item is renamed after the namespace is declared but was created before the namespace was declared. |
| • | Ontology items with unexpanded prefixes might not be correctly recognized. |
Saving the file
You can save the file with a .rdf or .owl extension using the File | Save (Ctrl+S) command. Save the file with the name AltovaDocuments.rdf.
In the next section you will create the classes and define the class hierarchy.
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