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Re: Another try.

From: Andy Seaborne <andy.seaborne@epimorphics.com>
Date: Tue, 21 Feb 2012 11:44:56 +0000
Message-ID: <4F4383B8.2060505@epimorphics.com>
To: public-rdf-wg@w3.org


On 21/02/12 07:56, Pat Hayes wrote:
> For conservatives among us, the opposite re-interpretation is always
> available. Any quad-graph can be thought of as a SPARQL dataset, by
> 'slicing' the quads according to their last argument, and
> re-declaring this parameter to be a graph label. However, to retain
> the semantic flexibility (ie to have the triples in each graph able
> to be re-interpreted differently in each labeled graph), we would
> have to modify the RDF semantics to allow for this graph-local
> context being involved in the truth recursions. And as already noted,
> it is simpler, and much less of a change ot the basic RDF model,  to
> do this by thinking of this construction in the quad-graph way as
> being a set of property-with-three-argument quads rather than as a
> collection of labelled sets of two-argument triples. And as so many
> of the 'natural' uses of datasets seem to want to take advantage of
> the apparent contextual' possibility of the graph label, and this
> option is only available in a quad-store format in any case, it seems
> comparatively harmless to attach the needed semantics directly to
> this quad store format, rather than tinker with the semantics of
> triples or try to make sense of graph 'names' which do not denote
> graphs.

I was wondering about existing vocabularies.

If I understand the quad proposal, then all existing vocabularies are 
technically undefined because they never define P(S,O,G), only P(S,O).

The graph-local context view seems to preserve the vocabulary by 
reinterpreting P(S,O).  It's less neat to have sets of triples + graph 
labels, but it does seem to carry-over existing data.

Have I missed something?

	Andy
Received on Tuesday, 21 February 2012 11:45:21 GMT

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