- From: Jeremy Carroll <jjc@hplb.hpl.hp.com>
- Date: Thu, 10 Jan 2002 15:31:38 -0000
- To: "Jan Grant" <Jan.Grant@bristol.ac.uk>, "Brian McBride" <bwm@hplb.hpl.hp.com>
- Cc: "RDFCore Working Group" <w3c-rdfcore-wg@w3.org>
I found Jan's message somewhat hard to follow. I'll not labour my disagreement with some of the assumptions about the meaning of M&S. In this message I will restrict my comments to bagID in an empty property element production. Jan: > OK, here I'm going to refer you to Dave's WD: > > http://www.w3.org/TR/2001/WD-rdf-syntax-grammar-20011218/#emptyPropertyElt > > (that is, section 5.14) > [...] > > (with the proviso that all of idAddr, resourceAttr and bagIdAttr are not > present at the same time. These alternatives can be enumerated) > Dave says "bagID cannot be used when there are no propertyAttr" I don't understand either restiction on bagID here. In either case, for me on my reading of M&S,a bagID unambiguously indicates the bag formed from the reifications of the property attributes (if any) of this property element. Hence a bagID on any otherwise empty property element generates one triple, the type triple for the bag. e.g. <rdf:RDF> <rdf:Description rdf:ID="A"> <rdf:value rdf:bagID="B" /> </rdf:Description> </rdf:RDF> ==> <#A> <rdf:value> _:a . <#B> <rdf:type> <rdf:Bag> . Adding prop attrs is unproblematic: <rdf:RDF> <rdf:Description rdf:ID="A"> <rdf:value rdf:bagID="B" a:a="a" /> </rdf:Description> </rdf:RDF> ==> <#A> <rdf:value> _:a . <#B> <rdf:type> <rdf:Bag> . _:a <a:a> "a" . _:r <rdf:type> <rdf:Statement>. _:r <rdf:subject> _:a . _:r <rdf:predicate> <a:a>. _:r <rdf:object> "a". <#B> <rdf:_1> _:r. ------------------------ An rdf:ID on this triple either indicates the reification of the <#A> <rdf:value> _:a . triple, on my preferred resolution, or indicates the identity of the object bNode (_:a) on the current text of the syntax WD. Either way there is no difficulty in having both a bagID and an ID. Jeremy
Received on Thursday, 10 January 2002 10:35:19 UTC