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Re: Agenda request: characterize the diffs between subgraph-matching and E-entailment

From: Bijan Parsia <bparsia@cs.man.ac.uk>
Date: Tue, 10 Oct 2006 17:29:46 +0100
Message-Id: <B3DFE3DA-952E-4F5F-AE07-EA927E293305@cs.man.ac.uk>
Cc: andy.seaborne@hp.com, RDF Data Access Working Group <public-rdf-dawg@w3.org>
To: Bijan Parsia <bparsia@isr.umd.edu>

On Oct 10, 2006, at 12:42 PM, Bijan Parsia wrote:

> On Oct 10, 2006, at 12:29 PM, Seaborne, Andy wrote:
>> Bijan Parsia wrote:
>>>> Test cases are:
>>>> 1/ A deliverable we are chartered to provide
>>>> 2/ A good way of making sure we are talking about the same thing.
>>> Sure, but I think progress on the semantics of the algebra are  
>>> achievable even without test cases, or with tests cases that  
>>> might have to be updated (just as they were with distinct).
>> No tests changed or were updated for DISTINCT.
> [snip]
> I didn't say there were. If we had adopted REALLYREALLYDISTINCT, we  
> *would have had* to update the test cases. Thus, with the DISTINCT,  
> there were test case that *might have had* to have been updated.
> I.e., the mere risk of having to change test cases shouldn't block  
> progress, IMHO, or affect how we discuss things. Just as it hasn't  
> in the past.
> In any case, I believe that the examples of problems with the  
> algebra can be stated against ground data, wherein LC1 and LC2  
> coincide. So, why should this be a blocker?
> Is this meta-debate useful? How about some commentary on the  
> problems with the semantics of conjunction in the algebra? After  
> all, it's not like this point is *new*, and it clearly must be  
> addressed.

Andy interpreted, in the telecon, this as my demanding he have read a  
lengthy email I posted this morning. To be clear, that would be a  
very unfair demand. I presumed that Andy had already thought about it  
(given his exchanges with Jorge), and thus could comment without  
having read it. Perhaps that's unfair too, but it's a different  
unfairness. I prefer being hanged for my actual sins!

I also, in this context, thought that the *only* problem with LC2  
semantics was the Jorge bug, which is fixable. This other thing is  
not nearly so obviously, and it affects ground graphs. (You can still  
write robust tests, I think; but it's more work; you have to ensure  
that there is only one way to derive an answer).

Received on Tuesday, 10 October 2006 16:31:21 UTC

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