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Re: RIF Working Group in a Nutshell

From: Anne Cregan <annec@cse.unsw.edu.au>
Date: Mon, 10 Sep 2007 13:39:39 +1000
To: Giorgos Stoilos <gstoil@image.ece.ntua.gr>
Message-Id: <97200120-20C3-41E9-9AC9-53F5D5F2C07B@cse.unsw.edu.au>
Cc: <public-xg-urw3@w3.org>


Thanks for that - I learnt something very important that I didn't  
realise before.
Are others as surprised as I am that RIF is ONLY going to be an  
format and is NOT attempting to build a language for writing Rules  
for the Semantic Web?

I think that for URW3 purposes, the ability to write rules will be  
critical, so we
  should keep a close eye on this.  Do we know of any working group  
taking this on?

Ken and Kathy - when you attend the W3C SemWeb Coordination Group
conference call, could you perhaps ask them what work is afoot to  
rule writing for the (semantic) Web?

I would assume whatever we deliver would need this as a vehicle.
Would others agree?


On 08/09/2007, at 4:23 PM, Giorgos Stoilos wrote:

> Dear All,
> During the August 1st telecon I promised to provide some feedback  
> to the
> group regarding the RIF Wroking Group (WG). Since it seems that I  
> will also
> miss some of the next telecons (both on the 19th and the 3rd it  
> seems that I
> will be travelling) I am sending a mail with some feedback.
> ==ID==
> - RIF stands for Rule Interchange Format.
> - It is a Working Group (unlike our Interest Group), i.e. it will  
> provide a
> standard (W3C Recommendation).
> - RIF is chartered for 2 years.
> - RIF home page: http://www.w3.org/2005/rules/
> - RIF Charter: http://www.w3.org/2005/rules/wg/charter.html
> - RIF wiki page: http://www.w3.org/2005/rules/wg/wiki/FrontPage
> == Objectives ==
> RIF is the current action of W3C for the rules layer of Semantic  
> Web. The
> primary purpose is to propose a format for interchanging rules  
> between rule
> systems on the (Semantic) Web and *NOT* to create a W3C Rule  
> Language for
> the Semantic Web. Thus, one should not expect to use RIF to  
> represent its
> rules, i.e. creating a RIF Rule Base.
> RIF is also expected to provide compatibility with current W3C  
> Semantic Web
> standards like RDF and OWL.
> == Architecture ==
> The work is split in to 2 phases:
> In phase 1 we will defined a RIF Core language which is lets say "a  
> minimum
> *interesting* fragment that is common over most logic programming  
> languages
> and systems". Then in phase 2 several RIF Dialects will extend or  
> restrict
> the semantics and functionality of RIF Core elements to create a rule
> interchange format for an LP language not supported by RIF Core.  
> Examples of
> RIF Dialects could be an F-Logic Dialect, a DisjunctiveDatalog  
> Dialect, a
> Horn+Negation, a Production Rule dialect, etc.
> So if you wanted to exchange rules between your Disjunctive Datalog  
> system
> and some other one (also a Disjunctive Datalog system) you would  
> have to
> implement a mapping from your rule base to the appropriate RIF  
> Dialect and
> of course the other part should also be able to translate the RIF  
> Rules to
> its own format.
> Maybe the group will examine some cases of exchanging rules between  
> diverse
> systems, i.e. a RIF StableNegationToWellFoundedNegation Dialect but  
> is only
> expected to do it for cases that such mapping has been studied in the
> literature and not do research on its own.
> Checkout: http://www.w3.org/2005/rules/wg/wiki/Arch/Extensibility
> == So Far ==
> The group started with UseCases & Requirements and until then it has
> produced 3 versions of them. The working version is here
> http://www.w3.org/2005/rules/wg/wiki/UCR.
> Currently the work is focused on RIF Core http://www.w3.org/TR/rif- 
> core/,
> its XML syntax, RDF Compatibility and build-ins. Originally RIF  
> Core was
> proposed to be Horn Logic + Sorts, but we have backtracked to Horn
> http://www.w3.org/2005/rules/wg/wiki/Core.
> Regarding dialects there was some work on a NegationDialect and some
> Prodcution Rule System dialect but I think little has been done on  
> this
> issue.
> == RIF and Uncertainty ==
> Since the beginning we (the NTUA-IVML group) have tried to bring up  
> the
> issue of uncertainty extensions of Semantic Web standards whenever  
> possible.
> Initially, we succeeded in having "uncertainty" mentioned in the  
> RIF Charter
> under the RIF Extensibility section
> http://www.w3.org/2005/rules/wg/charter#extensibility.
> Then during the UseCases work we added a UC for Fuzzy
> http://www.w3.org/2005/rules/wg/wiki/ 
> Fuzzy_Reasoning_with_Brain_Anatomical_S
> tructures but it didn't made it into the UCs document.  
> Nevertheless, we
> tried to add it implicitly through the Medical Decision support Use  
> Case
> http://www.w3.org/2005/rules/wg/wiki/UCR/ 
> Ruleset_Integration_for_Medical_Dec
> ision_Support that exists in it.
> As with the UseCases it seems that we could propose an Uncertainty  
> Dialect
> to the RIF group. Actually together with Carlos Damasio, Jeff Pan and
> Umberto Straccia we have already done some work for an Uncertainty RIF
> dialect in a paper to appear in Fundamenta Informaticae.
> But on the other hand from my experience in related W3C activities  
> I would
> say that it is unlike that such an extension will survive as a  
> dialect in
> the final standard. Uncertainty always looks kind of exotic to most  
> people,
> while several ones in RIF would definitely eagerly object having  
> them as a
> RIF Dialect. On the other hand even neutral people would prefer to  
> see a
> dialect covering their favourite or some popular system rather than
> uncertainty if it gets to choosing among "n" for standardization.  
> Moreover,
> as far as I know, the issue of uncertainty LP is not such mature in  
> the
> sense that there are not so many uncertainty rule bases and systems  
> out
> there that one would like to interchange between them. So our case is
> generally weak.
> Currently, it is not decided how many and which dialects would the  
> group
> create as well as the requirements for Phase 2
> http://www.w3.org/2005/rules/wg/wiki/Design_Constraints, where  
> uncertainty
> is included, have not been discussed yet.
> Hope I was concise enough. I also welcome any related questions.
> Greetings,
> -gstoil
Received on Monday, 10 September 2007 03:40:15 UTC

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