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Re: Slim RDF

From: Sergey Melnik <melnik@db.stanford.edu>
Date: Tue, 20 Feb 2001 19:16:01 -0800
Message-ID: <3A9332F1.951DEFE5@db.stanford.edu>
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 GMT

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