Rationale

There are a number of features familiar to people working with databases that either work differently in OWL (inheritence), are currently restricted (keys) or missing (integrity constraints). There is a great deal of work e.g., from the description logic community for adding variants of these features. There is also quite a bit of folk knowledge of how to work around the lack (either at the ontology level or the system level).

Current Topics

The TF is working on three topics at the moment:

1. Keys (EasyKeyProposal)
2. Constraints (aka, TBox closure)
3. Closing some part of your knowledge base. We distinguish between
• formalisms that allow to make general statements in your ontology and
• query languages that allow you to query with "closing" constructs such as epistemic operators

References

• Keys
• On the effects of using keys on datatype properties
• Keys For Ontologies – You Choose
• Can OWL model football leagues?
• Constraints
• Adding Integrity Constraints to OWL
• Bridging the Gap Between OWL and Relational Databases
• Closing some aspect of your knowledge
• Closing Semantic Web Ontologies
• Implementing OWL defaults
• Embedding Defaults into Terminological Representation Systems
• Careful closure of inheritance networks
• An epistemic operator for description logics
• Query languages with epistemic operators for "closing" your assumptions
• Using epistemic operators in query languages
• EQL-Lite: Effective First-Order Query Processing in Description Logics

Dependencies

Sometimes these features are realized in or in conjunction with rules or query languages, so SafeRules and SparqlOwl are relevant.

People

• Uli Sattler (point person)
• Ian Horrocks
• Bijan Parsia
• Evan Wallace
• Michel Dumontier
• Thomas Schneider