- From: Pierre-Antoine CHAMPIN <champin@bat710.univ-lyon1.fr>
- Date: Wed, 21 Feb 2001 13:39:19 +0100
- To: Sergey Melnik <melnik@db.stanford.edu>
- CC: RDF Interest Group <www-rdf-interest@w3.org>
Sergey Melnik wrote: > > Following the recent discussion on wrt syntax and namespaces I'd like to > mention the internal data model based on RDF that I'm using in my > research: > > Let U be the Unicode alphabet and U* the set of strings defined over U. > The set of entities E and the set of statements V are defined using the > following recursive definition: > > 1. U*xU* is subset of E (any tuple consisting of two strings is an > entity; the first string of the tuple is called namespace of the entity, > the second string is referred to as name of the entity) > > 2. ExExE is subset of V (every tuple of three entities constitutes a > statement) > > 3. V is subset of E (every statement is an entity) > > A subset of V is called "model". Without reification, E=U*xU* and V=E^3. > > The set of literals L is defined as L = {"urn:rdf:literal"} x U* (i.e. > literals are resources and can be used as subjects of statements). Other > primitive data types are handled similarly, e.g. ("urn:rdf:literal","5") > != ("urn:rdf:integer","5"). > > Notice that namespaces are first-class citizens. Resource ("xyz","") > 'reifies' namespace "xyz", so that statements about primitive classes > like the class of literals are possible. I agree it does. But why do you bother with { namespace, name } pairs, when the RDF model is about URIs ? Well I know it is also about literals, but it seems that you boldly pushed literals in the resource pool, which is all right to me, I must say. I know too that the RDF syntax in recomended in M&S is about namespaces and names, but this is a syntactical issue only. In the end, triples are only made of URIs, namespaces do not count. Or do they ? Pierre-Antoine Champin -- Sometimes I think the surest sign that intelligent life exists elsewhere in the universe is that none of it has tried to contact us. (Bill Watterson -- Calvin & Hobbes)
Received on Wednesday, 21 February 2001 07:39:28 UTC