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Re: datatypes and MT (#rdfms-graph)

From: Pat Hayes <phayes@ai.uwf.edu>
Date: Fri, 16 Nov 2001 11:35:11 -0600
Message-Id: <p05101078b81afd68278c@[]>
To: Graham Klyne <Graham.Klyne@MIMEsweeper.com>
Cc: w3c-rdfcore-wg@w3.org
>It's almost a victim of its own beauty ;-)

We will soon be talking about candles in the wind if we go on like this.

>I completely overlooked the section of graph merging when I 
>responded, partly because it was so short but mostly because I 
>wasn't expecting it to be in the section on entailment...   (That's 
>not much of an excuse really, it is well-enough signposted in the 
>document;  oh well.)
>Anyway, a simpler suggestion might be to simply move the definition 
>of graph merging up to section 0.2, just after the definition of 

Yes, I like that idea.  Put all the graph manipulating stuff into one 
place, then later on explain what it means. I'll try doing that; but 
not in the next-week version; since until we get the datatyping 
sorted out, its not clear what notion of 'tidiness' is appropriate, 
and I want to just slip past that issue at present.


>At 04:35 PM 11/15/01 -0600, Pat Hayes wrote:
>>>At 09:03 AM 11/15/01 -0600, Dan Connolly wrote:
>>>>No? Why not? How is it that you conclude that bnodes
>>>>in different graphs are different? I don't see it stated
>>>>in the model theory.
>>>It appears it's not stated directly, and probably should be since 
>>>that was (to me) clearly the intent of our discussions.  Also, the 
>>>final sentence of this text from section 2.0 pretty clearly 
>>>signals that intent:
>>>This effectively treats all unlabeled nodes as existentially
>>>quantified in the RDF graph in which they occur. Notice that since
>>>two nodes cannot have the same label, there is no need to specify
>>>the 'scope' of the quantifier within a graph. (However, it
>>>is local to the graph.) If we were to apply the semantics
>>>directly to N-Triples syntax, we would need to indicate the
>>>quantifier scope, since in this lexicalization syntax the same 
>>>bNode identifier may occur several times. The above rule amounts to
>>>the N-triple convention that would place the quantifiers just
>>>outside, i.e. at the outer edge of, the N-triple document
>>>corresponding to the graph.
>>The reason why this issue is treated rather elliptically in the MT 
>>is that the great merit of the graph syntax, as I see it, is that 
>>the issue simply *does not come up*.  There are no quantifiers, no 
>>bound variables and no scopes to keep track of, it all works out 
>>automatically. The merging conditions are a joy to state (merge 
>>nodes required to be tidy, ie urirefs; don't merge anything else.) 
>>It's beautiful. It seemed perverse to introduce the clunky logical 
>>notation only to be able to say that we don't have those problems.
>>If people feel that this issue should be aired more thoroughly, I 
>>would suggest that I write a slightly fuller account of how the 
>>graph syntax makes local scoping unnecessary, maybe with a couple 
>>of examples, and put it into the 'mapping into logic' section, and 
>>then refer to that from elsewhere in the document as needed. Any 
>>IHMC                                    (850)434 8903   home
>>40 South Alcaniz St.                    (850)202 4416   office
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>>phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes
>Graham Klyne                    MIMEsweeper Group
>Strategic Research              <http://www.mimesweeper.com>
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IHMC					(850)434 8903   home
40 South Alcaniz St.			(850)202 4416   office
Pensacola,  FL 32501			(850)202 4440   fax
Received on Friday, 16 November 2001 12:36:16 UTC

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