- From: Andy Seaborne <andy.seaborne@epimorphics.com>
- Date: Tue, 21 Feb 2012 11:44:56 +0000
- 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 UTC