1. Issue 134 Metamodel for OWL 2 Peter Haase, Elisa Kendall, Boris Motik, Evan Wallace

2. Current Structural Specification Comes with set of UML diagrams Intended to be compatible with MOF

3. MOF Metamodel for More Preciseness Precise definition of structural specification Example: Declaration rules Formal definition of structural consistency possible Lack of such a specification lead to a lot of confusion in OWL 1

4. Advantages of a MOF Metamodel for OWL 2 More preciseness in the structural specification (via OCL constraints) Machine-processable serialization of the specification Reuse of existing MOF tooling –E.g. automated generation of APIs, editors, etc. Possibility of specifying UML Profiles (visual syntax for ontologies)

5. UML Diagram of MOF Metamodel Integrity constraint: self.versionURI != 0 implies self.ontologyURI != 0

6. Metamodel Tooling

7. Concrete Proposal Make the use of MOF for the structural specification explicit by: 1)stating that the UML diagrams in the Structural Syntax document are consistent with a MOF compliant specification of the structural syntax 2)potentially adding a machine-readable serialization and high-level documentation of a MOF metamodel for OWL 2 as an additional document

8. Possible Future Work within ODM WG of the OMG Normative definition of OWL 2 metamodel, including –Extended descriptions of the metamodel –Provision of UML profiles –Alignment with other (existing) metamodels Alignment will be easier if structural specification of OWL 2 already provided as metamodel The OMG ODM WG therefore supports the definition of a first metamodel within the W3C OWL WG