- From: Boley, Harold <Harold.Boley@nrc-cnrc.gc.ca>
- Date: Tue, 7 Mar 2006 06:02:50 -0500
- To: <public-rif-wg@w3.org>
- Message-ID: <E4D07AB09F5F044299333C8D0FEB45E92DD64D@nrccenexb1.nrc.ca>
> - Roadmap > > ACTION: Frank to make his point about semantics of production rules on > the mailing list > > ACTION: Harold to explain technically the basis > for interoperation between PR and Horn rules Basic interoperation could be permitted on top of scopes (modules) of sets of facts used 'read-only' by Horn rules and 'read-write' by production rules. Production rules were formally explored in Active Database Systems, e.g. by Jennifer Widom and colleagues: http://infolab.stanford.edu/~widom/pubs.html J. Widom and S.J. Finkelstein. Set-Oriented Production Rules in Relational Database Systems <http://infolab.stanford.edu/pub/papers/rule-language.ps> . Proceedings of the ACM SIGMOD International Conference on Management of Data, pages 259-270, Atlantic City, New Jersey, May 1990. http://citeseer.ist.psu.edu/cache/papers/cs/558/http:zSzzSzwww-db.stanford.eduzSzpubzSzpaperszSzrule-language.pdf/widom90setoriented.pdf J. Widom. A Denotational Semantics for the Starburst Production Rule Language <http://infolab.stanford.edu/pub/papers/denotational.ps> . ACM SIGMOD Record, 21(3):4-9, September 1992. http://citeseer.ist.psu.edu/cache/papers/cs/558/http:zSzzSzwww-db.stanford.eduzSzpubzSzpaperszSzdenotational.pdf/widom92denotational.pdf The interoperation of Horn rules and production rules themselves could start with an expressive intersection of these two classes of rules. This may consist of an appropriate subset of -- syntactically sugared -- Horn rules (e.g., slotted Datalog) that also is a -- small -- subset of production rules (e.g., just having 'look-up' conditions and 'assert' actions). It is called 'pure production rules' in the Preliminary Design Roadmap, and moved to Phase 1, #4 for early studies: http://lists.w3.org/Archives/Public/public-rif-wg/2006Feb/0255.html (In the Charter, production rules were only in Phase 2, 3.2.5. Actions.) A benefit is that any extension we consider for the Phase 1 Horn conditions (e.g., NAF queries or built-in calls) could already be assessed for its merits in conditions of 'full production rules' in Phase 2. A cross-fertilization may take place between (Web) extensions of the two kinds of rules. Frank's concern that the intersection is too small etc. should be carefully considered, first, by working on a taxonomy of desirable RIF actions. -- Harold
Received on Tuesday, 7 March 2006 11:02:57 UTC