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Re: bnodes as answer bindings

From: Bijan Parsia <bparsia@cs.man.ac.uk>
Date: Fri, 4 Aug 2006 23:33:54 +0100
Message-Id: <D515E507-578B-4DEF-ABA1-2DC927C251F1@cs.man.ac.uk>
Cc: Pat Hayes <phayes@ihmc.us>, RDF Data Access Working Group <public-rdf-dawg@w3.org>
To: Enrico Franconi <franconi@inf.unibz.it>

On Aug 4, 2006, at 11:11 PM, Enrico Franconi wrote:

>
>> Can you give references for all this terminology that you cite?  
>> What exactly is the "active" domain? There is nothing in any  
>> semantic theory that I know of that distinguishes *things in the  
>> domain* on the basis of the kind of name that is used to refer to  
>> them with. The idea does not make sense, in any case: if bnodes  
>> were obliged to refer to a non-active domain while names refer to  
>> something else, then the troublesome redundancies would be  
>> eliminated.
>
> The first entry in <http://scholar.google.com/scholar?q=%22active 
> +domain%22+database> is a survey in DBs written 20 years ago.
>
>> I have never previously heard of this terminology of  
>> "distinguished" vs. "nondistinguished". (You have everyone's  
>> permission at this point to roll your eyes in amusement at my  
>> profound ignorance, of course.) I would be interested to see where  
>> this terminology was first used, and what its history is. In a  
>> database context where there are no bnodes, the distinction would  
>> be vacuous.
>
> Ah. Second and third entries in <http://scholar.google.com/scholar? 
> q=distinguished%20variables> are DB references from almost 30 years  
> ago.

And Pat's own acquaintance with some variants of the latter terminology:
	http://daml.semanticweb.org/listarchive/joint-committee/1024.html
	http://pride.daml.org/listarchive/joint-committee/1125.html

and
	http://daml.semanticweb.org/listarchive/joint-committee/1027.html

I believe the most deeply nested quote is Richard Fikes, the next  
level Pat, and the final line richard (in spite of the quote mark):

"""> >answer will include a binding for each distinguished variable.   
I am
 > >referring to the variables in the query pattern that are not
 > >distinguished variables as "non-distinguished variables".
 >
 > undistinguished variables?

 >From a quick check on the Web, I find them being called
"nondistinguished variables"."""

I don't expect Pat to have remembered this. It was, after all, 5  
years ago. It seems there is precedent for semi-distinguished  
variables in DQL. Richard Fikes seems (without having examined all  
the email) to have been the driver.

DQL reference is the third hit:
	http://www.google.com/search? 
hl=en&lr=&client=safari&rls=en&q=distinguished+variable&btnG=Search

Cheers,
Bijan.
Received on Friday, 4 August 2006 22:33:24 GMT

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