Re: Proposed Errata 16 (RIF-PRD)

On 11/13/2012 02:49 PM, Jesse Weaver wrote:
> Hi Christian.
>
> Please accept my apology for overlooking your email.  I would have 
> replied much sooner.
>
> There still seems to be a problem with the use of equality atoms.  I 
> sent an email about this problem to the public-rif-comments list on 
> September 6, 2012 (see 
> http://lists.w3.org/Archives/Public/public-rif-comments/2012Sep/0000.html 
> ), but I have not received a response to it.  Please see that email 
> since, having looked at the errata (specifically 
> http://www.w3.org/2005/rules/wiki/Errata ) just recently, it seems to 
> have gone unaddressed.
>
> By the way, I am at ISWC this week if anyone from the working group 
> (who is also at ISWC) would like to discuss this face-to-face.
>

Hi Jesse.   I know Mike Dean and I are here at ISWC, but for myself at 
least, this is outside my expertise (since it's about PRD). Hopefully 
Christian will have an answer for you shortly.

      -- Sandro

> Jesse Weaver
> Ph.D. Candidate, Patroon Fellow
> Tetherless World Constellation
> Rensselaer Polytechnic Institute
> http://www.cs.rpi.edu/~weavej3/index.xhtml 
> <http://www.cs.rpi.edu/%7Eweavej3/index.xhtml>
>
> On Oct 23, 2012, at 10:53 AM, Christian De Sainte Marie wrote:
>
>> Hi Jesse,
>>
>> Yes, I had noticed the inconsistency myself, and I corrected it in a 
>> subsequent version of the errata (see erratum 16.2 [1]).
>>
>> [1] http://www.w3.org/2005/rules/wiki/Errata#Erratum_16.2
>>
>> I think that all the reported errors have been corrected, now, and 
>> the are ready to publish the second edition.
>>
>> Would you be so kind and check all the errata again, and tell me if 
>> you find something?
>>
>> Thanx for your help,
>>
>> Christian
>>
>> IBM
>> 9 rue de Verdun
>> 94253 - Gentilly cedex - FRANCE
>> Tel./Fax: +33 1 49 08 29 81
>>
>>
>>
>>
>> From: Jesse Weaver <weavej3@rpi.edu <mailto:weavej3@rpi.edu>>
>> To: Christian De Sainte Marie/France/IBM@IBMFR
>> Cc: public-rif-comments@w3.org <mailto:public-rif-comments@w3.org>
>> Date: 14/08/2012 20:17
>> Subject: Proposed Errata 16 (RIF-PRD)
>> ------------------------------------------------------------------------
>>
>>
>>
>> Hi Christian.
>>
>> I was looking over the proposed errata for RIF ( 
>> _http://www.w3.org/2005/rules/wiki/Errata_), and I am quite happy 
>> with the proposed solution to errata 16.  I think, though, that there 
>> is a problem.  The proposed operational semantics for equality is 
>> stricter than the model-theoretic semantics of equality.  For 
>> example, as I understand it, _a=_b cannot be matched under the 
>> operational semantics, but it could be true under the model-theoretic 
>> semantics as long at I(_a)=I(_b), unless of course there is a unique 
>> name assumption.  I'm not sure of a good way to reconcile the two 
>> semantics, but perhaps at least a note should be made about the 
>> inconsistency if the proposed change to the operational semantics is 
>> made.
>>
>> Another possible solution would be to allow matching equality 
>> formulas to sets of facts, but then there is the problem of 
>> redefining State of the Fact Base to ensure symmetry and transitivity 
>> of equality facts.  It is more complicated, but it is consistent with 
>> the model-theoretic semantics.
>>
>> Personally, I like the simplicity of the proposed solution in the 
>> errata, but I just wanted to point out this potential inconsistency. 
>>  Thanks for addressing previously reported issues in the errata.
>>
>> Jesse Weaver
>> Ph.D. Student, Patroon Fellow
>> Tetherless World Constellation
>> Rensselaer Polytechnic Institute
>> _http://www.cs.rpi.edu/~weavej3/index.xhtml_ 
>> <http://www.cs.rpi.edu/%7Eweavej3/index.xhtml>
>>
>>
>>
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