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RE: rdf semantics and timelessly true

From: Cory Casanave <cory-c@modeldriven.com>
Date: Wed, 14 Nov 2012 11:36:20 -0500
To: Pat Hayes <phayes@ihmc.us>, "nathan@webr3.org" <nathan@webr3.org>
CC: Sergey Larionov <s.larionov@rks.karelia.ru>, Semantic Web <semantic-web@w3.org>
Message-ID: <B23E95FEF5A8F641B5798F35419555F29FF30AC255@EXCH2K7CCR.VIRTUMEN.LOCAL>
Re: It assumes, implicitly, that URI references have the same meaning whenever they occur."

That assumption seems to have been overtaken by events, technologies and usage over time. 

> -----Original Message-----
> From: Pat Hayes [mailto:phayes@ihmc.us]
> Sent: Wednesday, November 14, 2012 11:27 AM
> To: nathan@webr3.org
> Cc: Sergey Larionov; Semantic Web
> Subject: Re: rdf semantics and timelessly true
> 
> 
> On Nov 14, 2012, at 8:03 AM, Nathan wrote:
> 
> > Hi Pat,
> >
> > Pat Hayes wrote:
> >> Its not impossible, and in a strong sense this is required by the current RDF
> semantics, which treats all RDF assertions as timelessly true.
> >
> > Can you refine / expand on this please? I'd presumed RDF to have no
> consideration of time - e.g time-less; as opposed to being true for all time
> (timeless).
> >
> > TIA,
> >
> > Nathan
> 
> Yes, time-less is a better way to put it. But it is so because URIreferences are
> assumed (and I know this is an idealization, but...) to be timeless in how they
> refer. Section 1.2 says:  "... the semantics simply assumes that ... a single URI
> reference can be taken to have the same meaning wherever it occurs. Similarly,
> the semantics has no special provision for tracking temporal changes. It
> assumes, implicitly, that URI references have the same meaning whenever they
> occur."
> 
> In other words, no counters allowed.
> 
> Pat
> 
> 
> >
> >
> 
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> 
> 
> 
> 
Received on Wednesday, 14 November 2012 16:36:55 GMT

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