- From: Sergey Melnik <melnik@db.stanford.edu>
- Date: Tue, 20 Feb 2001 19:16:01 -0800
- To: "McBride, Brian" <bwm@hplb.hpl.hp.com>
- CC: RDF Interest Group <www-rdf-interest@w3.org>
I did the proof almost 3 years ago with help of a theory professor back in Germany, it's not quite trivial and I don't have time to revive right now. Basically, you construct an infinite chain of sets V1, E1, V2, E2, ..., Vn, En, ... similarly to a recursive "invocation" of the definition, if viewed as a imperative program. Then, I believe, you show that something like the union of all Vi's and Ei's satisfies the requirements of the definition. Best, Sergey "McBride, Brian" wrote: > > This seems a bit counter intuitive. I'd love to see the > proof. > > Brian > > > -----Original Message----- > > From: Sergey Melnik [mailto:melnik@db.stanford.edu] > > Sent: 19 February 2001 22:51 > > To: McBride, Brian > > Cc: RDF Interest Group > > Subject: Re: Slim RDF > > > > > > "McBride, Brian" wrote: > > > > > > Hi Sergey, > > > > > > In the model you describe, it seems that ExExE is a subset of E. > > > Is E a well formed set? > > > > It is, this can be proven formally. > > > > Sergey > > > > > > > Brian > > > > > > > -----Original Message----- > > > > From: Sergey Melnik [mailto:melnik@db.stanford.edu] > > > > Sent: 12 February 2001 20:09 > > > > To: RDF Interest Group > > > > Subject: Slim RDF > > > > > > > > > > > > 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. > > > > > > > > The above data model subsumes the RDF model defined in M&S 1.0. > > > > > > > > Sergey > > > > > > > > P.S.: since Oct 2000, RDF API > > > > (http://www-db.stanford.edu/~melnik/rdf/api.html) supports > > > > namespaces as > > > > part of the model, so that both parser and serializer > > included in the > > > > API can handle resources like > > > > ("http://www.w3.org/1999/XMLSchema","date") correctly.
Received on Tuesday, 20 February 2001 22:08:06 UTC