- From: Dan Connolly <connolly@w3.org>
- Date: Thu, 27 Sep 2001 18:05:30 -0500
- To: Pat Hayes <phayes@ai.uwf.edu>
- CC: w3c-rdfcore-wg@w3.org
Pat Hayes wrote: > > >Consider this nice, clean graph model for RDF > >(borrowing liberally from Peter F. Patel-Schneider's > >message to www-rdf-logic of Thu, 27 Sep 2001 10:37:29 -0400): > > > >An RDF graph is a four-tuple (that can be considered to be a > >partially labeled, directed graph; the unlabelled nodes > >are bNodes) > > < N, E, LN, LE > > > where N is the set of nodes in the graph > > LN :(partial) N -> URI u L gives labels for nodes > > LE :(partial) E -> URI gives labels for edges > > E <= N x N is the set of edges in the graph > > Why is LE partial? Is that deliberate? It was deliberate, yes. It evidently wasn't sufficiently careful, though. [...] > >(not in the issues list?) > > can I use a bNode in the predicate part of an RDF statement? > > > > yes. > > > > In N-triples, yes. But its not like the node case in the graph; here, > that bNode label has to really be in the graph; and then it had > better be there for 'unlabelled' nodes as well, since otherwise there > is no way to know that a bNode used as an arc label is the same as a > bNode labelling a node. Basically, the whole 'tidyness' notion goes > out the window when we have bArcs., and much of the simplicity of the > graph syntax is lost. > > Still, we could live with N-triples as a canonical syntax, if we want > to go that way. Hmm... I see. I'll have to think about that. -- Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Thursday, 27 September 2001 19:05:31 UTC