RRD

Editors

Adrian Paschke, Freie Universitaet Berlin

Harold Boley, National Research Council Canada

1 Overview

This document specifies the Reaction Rule Dialect of the W3C rule interchange format (RIF-RRD). Complementing RIF-PRD [RIF-PRD], which introduces rule actions, RIF-RRD adds the triggering of rules from events.

We distinguish atomic and complex events. An atomic event (also raw event or primitive event) is defined as an instantaneous (at a specific point in time), significant (relates to a context), indivisible (cannot be further decomposed and happens completely or not at all) occurrence of a happening. A complex event is composed (composite event) or derived (derived event) from occurred atomic or other complex event instances, as described, e.g., according to the operators of an event algebra or as a result of applying an algorithmic function or process to one or more other events.

In general, a reaction rule consists of parts for event/situation processing (e.g. detection, computation), condition verification, action invocation, and post-condition verification, where the condition and (especially) the post-condition parts are optional. The event/situation part can also specialize to the detection of changing conditions, as in a production rule. Therefore, RIF-RRD constitutes an extension of RIF-PRD [RIF-PRD].

A great variety of approaches have been developed for reaction rules, which have for the most part evolved separately in their respective domains, and which have led to different views and terminologies. Some detect events as they occur and directly react to them, as e.g. in active databases or implicitly in production rule systems which are fired by changing conditions in the working memory.

The current version of RIF-RRD has its focus on reaction rules that are Event-Condition-Action (ECA) rules. Native events are added to the Condition-Action (CA) rules of RIF-PRD, thus avoiding their (imperfect) management as special working-memory facts ('reified events'). This is the next step on top of RIF-PRD, both theoretically and practically.

2 References

2.1 Normative References

[RFC-3987]

RFC 3987 - Internationalized Resource Identifiers (IRIs), M. Duerst and M. Suignard, IETF, January 2005. This document is http://www.ietf.org/rfc/rfc3987.txt.

[RIF-DTB]

RIF Datatypes and Built-Ins 1.0, Polleres A., Boley H. and Kifer M. (Editors), W3C Rule Interchange Format Working Group Draft. Latest Version available at http://www.w3.org/2005/rules/wiki/DTB.

[RIF-FLD]

RIF Framework for Logic Dialects, Boley H. and Kifer M. (Editors), W3C Rule Interchange Format Working Group Draft. Latest Version available at http://www.w3.org/2005/rules/wiki/FLD.

[RIF-PRD]

RIF Production Rule Dialect, de Sainte Marie C., Paschke A., Hallmark G. (Editors), W3C Rule Interchange Format Working Group Draft. Latest Version available at http://www.w3.org/2005/rules/wiki/PRD.

[XML1.0]

Extensible Markup Language (XML) 1.0 (Fourth Edition), W3C Recommendation, World Wide Web Consortium, 16 August 2006, edited in place 29 September 2006. This version is http://www.w3.org/TR/2006/REC-xml-20060816/.

[XML-SCHEMA2]

XML Schema Part 2: Datatypes, W3C Recommendation, World Wide Web Consortium, 2 May 2001. This version is http://www.w3.org/TR/2001/REC-xmlschema-2-20010502/. The latest version is available at http://www.w3.org/TR/xmlschema-2/.

2.2 Informational References

[ANF01]

Normal Form Conventions for XML Representations of Structured Data, Henry S. Thompson. October 2001. Available at http://www.ltg.ed.ac.uk/~ht/normalForms.html.

[RIF-UCR]

RIF Use Cases and Requirements, Paschke A., Hirtle D., Ginsberg A., Patranjan P-L., McCabe F. (Editors), W3C Rule Interchange Format Working Group Draft. Latest Version available at http://www.w3.org/2005/rules/wiki/UCR.