Terry --

There's another, rather radical approach you may like to consider to the formal semantics of RDF.

A practical example is at

   http://www.reengineeringllc.com/demo_agents/RDFQueryLangComparison1.agent

The general case goes like this:

1.  Regard any collection of RDF as a set of triples representing ground facts

2.  Allow stratified, range restricted datalog rules with negation-as-failure for reasoning over the ground facts, and

3.  Use the model theoretic semantics of [1,2]  to specify what *should* be derivable from a collection of triples and rules.

There's some motivation for the approach in [3,4].

What do you think about this approach?  Does it for example miss assigning a useful semantics to an important real world use-case?

                        Cheers,  -- Adrian


[1]   Towards a theory of declarative knowledge,
in J. Minker, ed., Foundations of Deductive Databases, pp 89-148, (Morgan
Kaufmann, Washington, 1988).

[2]  Backchain Iteration: Towards a Practical Inference Method that is Simple Enough to be Proved Terminating, Sound and Complete. Journal of Automated Reasoning, 11:1-22

[3]  http://www.w3.org/2004/12/rules-ws/paper/19

[4]  http://lists.w3.org/Archives/Public/public-rule-workshop-discuss/2005Jun/att-0006/00-part


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Adrian Walker
Reengineering LLC
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Bristol
CT 06011-1412 USA

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At 10:55 AM 6/16/2005 -0400, Hardgrave, Terry \(Contractor\) wrote:


RDF Team--

My suggestion is that you base the formal semantics of RDF on
the work of Chris Strachey, Dana Scott, etc.  --  i.e. on "denotational semantics" and set theory--
rather than on model-theory/graph-theory.  The primary reason is that graph theory
will not (easily) support Boolean query languages on the structures.  To support the semantics
of Boolean query languages, you need to use set-theory directly.

Chris Strachey developed something based on triples years ago, but I have not been able to
find the reference to it.  I would need to ask some of my colleagues to hunt it down.

Here is one reference.  If you are interested in pursuing this further, please let me know, and
I will provide additional references.

http://vmoc.museophile.com/pioneers/strachey.html

Thanks,
Terry Hardgrave

terry.hardgrave@ed.gov
terry.hardgrave@pearson.com