W3C W3C Member Submission

OWLlink Extension:

W3C Member Submission 1 July 2010

This version:
Latest version:
Olaf Noppens, derivo GmbH (formerly Ulm University)
Thorsten Liebig, derivo GmbH (formerly Ulm University)
Marko Luther, DOCOMO Euro-Labs, Munich

This document is available under the W3C Document License. See the W3C Intellectual Rights Notice and Legal Disclaimers for additional information.


OWLlink provides a declarative interface for – among other things – asserting OWL axioms to a Knowledge Base (KB) of an OWL reasoner. This OWLlink extension adds the ability to retract previously asserted axioms from KBs.

Status of this Document

This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications can be found in the W3C technical reports index at http://www.w3.org/TR/.

This document is a part of the OWLllink Submission which comprises eight documents:

  1. OWLlink: Structural Specification
  2. OWLlink: HTTP/XML Binding
  3. OWLlink: HTTP/Functional Binding
  4. OWLlink: HTTP/S-Expression Binding
  5. OWLlink Extension: Retraction (this document)
  6. OWLlink Extension: Retraction HTTP/XML Binding
  7. OWLlink Extension: Retraction HTTP/Functional Binding
  8. OWLlink Extension: Retraction HTTP/S-Expression Binding

Earlier drafts of the OWLlink specification have been published by the informal OWLlink working group at http://www.owllink.org.

By publishing this document, W3C acknowledges that the Submitting Members have made a formal Submission request to W3C for discussion. Publication of this document by W3C indicates no endorsement of its content by W3C, nor that W3C has, is, or will be allocating any resources to the issues addressed by it. This document is not the product of a chartered W3C group, but is published as potential input to the W3C Process. A W3C Team Comment has been published in conjunction with this Member Submission. Publication of acknowledged Member Submissions at the W3C site is one of the benefits of W3C Membership. Please consult the requirements associated with Member Submissions of section 3.3 of the W3C Patent Policy. Please consult the complete list of acknowledged W3C Member Submissions.

Table of Contents

1 Introduction

The OWLlink core interface [OWLlink Structural Specification] relies on a certain kind of incremental batch-oriented reasoning procedure. After submission of a set of axioms a client can pose some queries, add further axioms, query again, and so on. Deletion of axioms is ony possible by releasing a KB and re-submission of axioms. This document describes the retraction extension of OWLlink which allows to retract previously told KB fragments on axiom level.

This extension is based on the same preliminaries than the OWLlink core.

2 Retraction

The Retract request is the inverse command to Tell (cf. Section ‘4 Tells’ [OWLlink Structural Specification]) and takes a set of OWL 2 axioms (cf. Section ‘9 Axioms’ [OWL 2 Structural Specification]) and removes them from the respective KB as shown in Figure 1. The removal must be sensitive to the rules of structural equivalence of OWL 2. That is, an axiom can only be removed from a KB if and only if the KB contains an axiom which is structural equivalent to the one given in the retraction request. A server must not respond with an error if a KB does not contain a structurally equivalent axiom but is free to provide a warning. If all axioms of a retraction request are successfully removed from the KB, the server has to respond with an OK response.

Retraction Request
Figure 1. Retraction Request (the Tell request is rendered semi-transparently to show the symmetry)

3 References

[OWLlink Structural Specification]
OWLlink: Structural Specification Document included in the present W3C Member Submission.
[OWL 2 Specification]
OWL 2 Web Ontology Language: Structural Specification and Functional-Style Syntax Boris Motik, Peter F. Patel-Schneider, Bijan Parsia, eds. W3C Recommendation, 27 October 2009, http://www.w3.org/TR/2009/REC-owl2-syntax-20091027/. Latest version available at http://www.w3.org/TR/owl2-syntax/.