Section 8. Built-Ins


8. Built-Ins

The set of built-ins for SWRL is motivated by a modular approach that will allow further extensions in future releases within a (hierarchical) taxonomy. At the same time, it will provide the flexibility for various implementations to select the modules to be supported with each version of SWRL.

SWRL's built-ins approach is also based on the reuse of existing built-ins in XQuery and XPath, which are themselves based on XML Schema Part 2: Datatypes.

This system of built-ins should also help in the interoperation of SWRL with other Web formalisms by providing an extensible, modular built-ins infrastructure for Semantic Web Languages, Web Services, and Web applications.

SWRL built-ins are used in builtin atoms. For example, swrlx:builtinAtom identifies a built-in using the swrlx:builtin attribute and lists its arguments as subelements.

Swrl built-ins are identified using the http://www.w3.org/2003/11/swrlb namespace.

8.1. Built-Ins for Comparisons

8.2. Math Built-Ins

The following built-ins are defined for various numeric types. For the relation to be satisfied the arguments all have to belong to some numeric type for which the relation is defined.

8.3. Built-Ins for Boolean Values

8.4. Built-Ins for Strings

The following built-ins are defined for strings (only), i.e., not untyped literals with language tags.

8.5. Built-Ins for Date, Time and Duration

The following built-ins are defined for the XML Schema date, time, and duration datatypes, only, as appropriate.

8.6. Built-Ins for URIs

The following built-ins are defined for the XML Schema datatypes related to URIs.

8.7. Built-Ins for Lists

The following built-ins are defined for RDF-style lists. (Note that these built-ins are not usable in OWL DL or OWL Lite as RDF-style lists can only be used as OWL data in OWL Full.)