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Re: RIF Working Group in a Nutshell

From: Jeff Z. Pan <jpan@csd.abdn.ac.uk>
Date: Mon, 10 Sep 2007 11:42:35 +0100
Message-ID: <46E51F9B.50209@csd.abdn.ac.uk>
To: Ken Laskey <klaskey@mitre.org>
CC: Anne Cregan <annec@cse.unsw.edu.au>, Giorgos Stoilos <gstoil@image.ece.ntua.gr>, public-xg-urw3@w3.org

Hi Ken and all,

Ken Laskey wrote:
> Anne,
> The intent of RIF is to avoid choosing the winner among possible rules 
> formats and to theoretically come up with a way of exchanging 
> information across formats.  There was always the question of whether 
> one could write the interchange format without effectively writing a 
> new rules language.


> URW3 is modeled with the idea behind RIF in mind to see if we can 
> "interchange" uncertainty information without (or at least minimizing) 
> making things specific to an uncertainty methodology.  The answer is 
> far from obvious.
> As for whether there can be an uncertainty dialect for RIF, our 
> challenge is to identify what would be in such a dialect.  I hope RIF 
> provides a Dialect Framework to which others could develop specific 
> dialects.  In that case, there would be less pressure on the scarce 
> resources of a single WG.

Currently only two dialects are being developed in phase one of RIF, 
some others will be in the second phase of RIF (which hasn't been 
formally approved yet, I think). If our XG becomes a WG (or merges into 
a Task Force in RIF) at some point, we could formally propose an 
uncertainty dialect there.

> Still, the current XG will not develop a Dialect because 
> (1) we have yet to establish what would go into such a dialect
> (2) RIF hasn't sufficiently defined a dialect framework
> (3) we aren't chartered to develop a dialect (but a future group might)
> Other thoughts?

Some Fuzzy RuleML folks and I  have a paper about Uncertainty in RuleML 
[1]. In this paper, we also discuss an uncertainty dialect for RIF 
(Section 6). Comments are welcome.


[1] Carlos Viegas Damasio, Jeff Z. Pan, Giorgos Stoilos and Umberto 
Straccia. *Representing Uncertainty in RuleML*. In /Fundamenta 
Informaticae/. To appear. 2007. Available at 

> Ken
> On Sep 9, 2007, at 11:39 PM, Anne Cregan wrote:
>> Giorgos,
>> 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 
>> interchange
>> 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 support
>> rule writing for the (semantic) Web?
>> I would assume whatever we deliver would need this as a vehicle.
>> Would others agree?
>> Anne
>> 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
> -----------------------------------------------------------------------------
> Ken Laskey
> MITRE Corporation, M/S H305      phone: 703-983-7934
> 7151 Colshire Drive                         fax:       703-983-1379
> McLean VA 22102-7508
Received on Monday, 10 September 2007 10:44:07 UTC

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