Hi Pat,
On 03/25/2013 01:28 AM, Pat Hayes wrote:
On Mar 24, 2013, at 10:41 PM, David Booth wrote:
[ . . . ]
>> Given n interpretations and n graphs, it is perfectly valid to use
the RDF Semantics to determine the truth-values of each of those n
graphs relative to those n interpretations, without in any way
violating the spec.
Well, yes, the spec does not actually say anything about what anyone
*does*. So there is no law against doing this, so to speak.
Thank you!
But
calling it "valid" is a stretch. The RDF semantic specification is
intended to define a model theory, to be used to specify a semantics
in the way conventionally used throughout formal logic, and as
described in many textbooks. What you are suggesting here is not
using the specification in this way, as a model theory, so it is a
mis-use of the specification. For example, using your ideas, none of
the inference rules provided in the 2004 specification would be
valid.
Clearly, however, you are immune to explanations,
Well, there's the pot calling the kettle black! :)
so I think I will
give up at this point. If you wish to misuse the specifications in
pursuit (a vain pursuit, I will add) of some half-baked fantasy of
your own, I guess there is nothing I or anyone else can do to stop
you.
Fantasy? [Musing: "There exists a fantasy world in which each URI
denotes the same resource in *every* RDF graph, and although multiple
interpretations are permitted, which would map the same URI to different
resources, discussing more than one interpretation at a time is strictly
forbidden . . . ."]
It would be absurd to claim that determining the truth-values of both
I1(G1) and I2(G2), where I1 and I2 are different interpretations and G1
and G2 are different graphs, somehow constitutes a "misuse" of the RDF
Semantics spec.
Look, *you* may not like using the RDF Semantics spec this way. But I
think you are selling your work short by discouraging others from doing
so. The spec is an excellent piece of work and there is significant
value in taking a birds-eye view of it and recognizing that it can be
used in more real-life ways than you initially expected.
The fact that the RDF Semantics spec was written in the style of model
theory is all fine and dandy. I think it works pretty well. But it is
**completely irrelevant** to the spec's purpose. The spec could just as
well have been written in any other sufficiently precise style --
denotational semantics, operational semantics, whatever -- and still
serve the exact same purpose: to define a standard way of determining
the truth-value of any RDF graph, given any interpretation.
To claim that the model theoretic style in which the RDF Semantics spec
was written has any bearing whatsoever on the spec's purpose or its
"appropriate use" would be a serious misrepresentation of its role as a
W3C standard.
David Booth