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Proposal for Deferrment and Closure (was Re: Reopening tidy/untidy decision)

From: Patrick Stickler <patrick.stickler@nokia.com>
Date: Mon, 30 Sep 2002 10:58:12 +0300
Message-ID: <000201c26858$c2b137c0$c74416ac@NOE.Nokia.com>
To: "ext Eric Miller" <em@w3.org>, "w3c-rdfcore-wg" <w3c-rdfcore-wg@w3.org>



I would like for consideration of the following proposal 
to be added to the aggenda for the October 4 telecon,
preferably including a vote for or against its adoption.



----- Original Message ----- 
From: "ext Eric Miller" <em@w3.org>
To: <w3c-rdfcore-wg@w3.org>
Sent: 26 September, 2002 21:55
Subject: Reopening tidy/untidy decision



> Achieving concensus is a difficult task at best, and this particular
> issue of tidy/untidy literals has unfortunately plagued us more than any
> would have liked.
> 
> We need to finish the stablization of the core RDF
> specifications as soon as possible.
> 
> Our deadline has passed. Please look again at this decision and give
> careful consideration to the impact on the WG schedule.
> 
> -- 
> eric miller                              http://www.w3.org/people/em/
> semantic web activity lead               http://www.w3.org/2001/sw/
> w3c world wide web consortium            http://www.w3.org/



It does not appear that the present RDF Core WG will achieve any
reasonably concensus on this issue, and it is unlikely to be
productive to extend a debate which has remained deadlocked for
over a year without significant new input into the process, which
is unlikely to come, apart from further implementational experience.

I therefore propose to the RDF Core WG that the issue of string versus
value based interpretation of inlined literals be deferred to a future
working group, and that the WG complete all its specifications as 
expediently as possible reflecting the decisions made to date,
and complete its charter.

The RDF MT should assign no interpretation whatsoever to inlined literals,
and should license no entailments involving triples containing inlined
literals.

Inlined literals remain "semantic wildcards" which are fully ambiguous
to the RDF MT and have no explicit nor consistent meaning across
applications, unless such a consistent intepretation is agreed to
by applications separately from and in addition to the RDF MT. The
RDF Core WG does not suggest any particular mechanism(s) for such
extra-MT agreements.

The representation of inline literals in the abstract graph syntax
remains as decided, with each occurrence of an inlined literal represented
by a distinct node in the graph, without any special prefixation or other
modification of the node label relating to its unique occurrence.

Thus, the following entailment would NOT hold, insofar as the RDF MT
is concerned:

IF
   ?s ?p "LLL" .
THEN
   ?s ?p _:x .

and therefore NEITHER of the following datatyping entailments would hold:

IF
   ?s ?p "LLL" .
   ?s ?q "LLL" .
THEN
   ?s ?p _:x .
   ?s ?q _:x .

IF
   ?s ?p "LLL" .
   ?s ?q "LLL" .
   ?p rdfs:range ?d .
   ?q rdfs:range ?d .
   ?d rdf:type rdfs:Datatype .
THEN
   ?s ?p _:x .
   ?s ?q _:x .

The interpretation of inlined literals, and the relations between inlined
literals and rdfs:range assertions or any other assertions in the graph
remains undefined by the RDF MT and up to each individual application to 
decide if and what interpretations might be assigned to inlined literals.

The following graph does not constitute a type clash, as no interpretation
is provided for the inline literal by the RDF MT itself:

   ?s ?p "LLL" .
   ?p rdfs:range ?d .
   ?d rdf:type rdfs:Datatype .

Individual applications, however, are free to interpret the above
range assertion as affecting the interpretation of the inlined
literal in some manner, if they so choose. Or they are free to ignore
the presence of the range assertion as having no affect whatsoever on
the intepretation of the inlined literal. The RDF MT does not support,
require, presume, suggest, or prefer either choice.

Member organizations are encouraged to continue research and evaluation
of systems based on various interpretations, as well as to publish 
proposed or preferred solutions and experience as W3C Notes or by other 
means, and it is hoped that further experience gained from such work will 
prove to be valueable input to future working groups addressing this issue.

Patrick

[Patrick Stickler, Nokia/Finland, (+358 40) 801 9690, patrick.stickler@nokia.com]

 
Received on Monday, 30 September 2002 04:10:11 EDT

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