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Re: three kinds of dataset

From: Pat Hayes <phayes@ihmc.us>
Date: Thu, 8 Mar 2012 20:09:00 -0600
Cc: Antoine Zimmermann <antoine.zimmermann@emse.fr>, "Peter F. Patel-Schneider" <pfpschneider@gmail.com>
Message-Id: <10339B47-F9D0-4247-8F28-C53356C05608@ihmc.us>
To: RDF-WG WG <public-rdf-wg@w3.org>
Quick thought: the wiki version of AZs semantics also supports a natural sense of a set of datasets entailing another dataset, and even of a set of datasets being merged (graph-merge the default graphs and any graphs with the same label, then put all labelled graphs into the dataset-merge) and together entailing their merge. Even if we don't want to go this far, the fact that all this falls out automatically from the definition is  mark in its favor, IMO. 

Pat

On Mar 6, 2012, at 1:34 PM, Pat Hayes wrote:

> Just for clarification, all I really wanted was to have a definition of satisfaction which preserves the standard definition of entailment as perserving truth in interpretations. Both Peter's and my earlier suggested modification (now in the wiki) do this. I think mine is simpler, but whatever. The only real difference is the possibility of allowing infinite contexts. 
> 
> Pat
> 
> On Mar 6, 2012, at 12:31 PM, Peter F. Patel-Schneider wrote:
> 
>> Well, I don't see where the infinity causes problems.  RDF datasets and
>> RDF graphs are going to be finite, after all, aren't they?  Perhaps for
>> mathematical cleanliness you might want to allow interpretations to have
>> an infinite number of names, I suppositions
>> 
>> The wiki seems to be missing the notion that Con(V) is an interpretation
>> of the graph with name V.
> 
> Its an interpretation of the vocabulary, not of the graph. The vocabulary of a dataset is all the URIs that occur in the dataset.
> 
>> 
>> In any case, the two formulations appear to be quite close (modulo the
>> issue just above).
>> 
>> peter
>> 
>> 
>> 
>> From: Antoine Zimmermann <antoine.zimmermann@emse.fr>
>> Subject: Re: three kinds of dataset
>> Date: Tue, 06 Mar 2012 19:10:36 +0100
>> 
>>> Why not indeed?  This was my original idea, modulo a little improper
>>> formulation (you can see the previous version in the wiki) but 1) Pat
>>> was very much against this formulation, and 2) the current formulation
>>> allows a dataset-interpretation to assign a "local" interpretation to a
>>> potentially infinite set of terms. This is particularly useful for
>>> reasoning with annotated triples (UC 6.2 in
>>> http://www.w3.org/2011/rdf-wg/wiki/TF-Graphs-UC#.28B_priority.29_Reasoning_over_annotations).
>>> 
>>> Le 06/03/2012 18:52, Peter F. Patel-Schneider a écrit :
>>>> Why not just say that an RDF/RDFS/... dataset interpretation of
>>>> 	D = (G, {<n1,G1>, ...,<nk,Gk>})
>>>> is a structure
>>>> 	I = (I, {<m1,I1>, ...,<mh,Ih>})
>>>> where I is an RDF/RDFS/... interpretation of G
>>>> and for each 1<=i<=k there is a j, 1<=j<=h such that mj=ni
>>>> and Ij is an RDF/RDFS/... interpretation of Gi
>>>> (could also require ni distinct and h=k)
>>>> 
>>>> Then	D = (G, {<n1,G1>, ...,<nk,Gk>})
>>>> entails D' = (G', {<n'1,G'1>, ...,<n'k',G'k'>})
>>>> just when every RDF/RDFS/... datatset interpretation of D
>>>> is also an RDF/RDFS/... datatset interpretation of G'
>>>> 
>>>> peter
> 
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------------------------------------------------------------
IHMC                                     (850)434 8903 or (650)494 3973   
40 South Alcaniz St.           (850)202 4416   office
Pensacola                            (850)202 4440   fax
FL 32502                              (850)291 0667   mobile
phayesAT-SIGNihmc.us       http://www.ihmc.us/users/phayes
Received on Friday, 9 March 2012 02:09:36 GMT

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