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Re: completion of action: 2001-07-27#2 (long) (use/mention in reification)

From: pat hayes <phayes@ai.uwf.edu>
Date: Fri, 7 Sep 2001 07:51:31 -0700
Message-Id: <v04210103b7be1c00416b@[130.107.66.237]>
To: Dan Connolly <connolly@w3.org>
Cc: w3c-rdfcore-wg@w3.org
>pat hayes wrote:
> >
> > >pat hayes wrote:
> > > >
> > > > >Brian McBride wrote:
> > > > > >
> > > > > > pat hayes wrote:
> > > > > > [...]
> > > > > > > Wait a minute. The subject is a URI, not a Resource, right?  The
> > > > > > > Resource is what the subject (a piece of syntax) denotes, not the
> > > > > > > subject itself.
> > > > >
> > > > >That's what you'd think, coming from a logic background, but
> > > > >as Brian points out, RDF says the subject of
> > > > >       Mary hit the ball.
> > > > >
> > > > >is a female person, not a word starting with 'M'.
> > > > >
> > > > >This is mother of all use/mention bugs, IMO.
> > > > >
> > > > >cf
> > > >
> > > > Indeed. If we have to take this seriously then I withdraw the model
> > > > theory, since it can't possibly work.
> > >
> > >You mean the reification part of the model theory, right?
> > >
> > >The rest is fine.
> >
> > No, I meant it all.  But I spoke hastily. I guess anything can be a
> > symbol, so maybe my mother  *could* be in a grammar.
>
>Hang on... there are two parts to this issue:
>(1) sloppiness in the way the RDF core is specified, and
>(2) sloppiness in the way RDF reification is specified.
>
>Regarding (1), I suggest we regard all these use/mention
>bugs in the RDF M&S spec as just that: use/mention bugs;
>and let's clean them up.

OK, I'd like to do that also.  Im glad we agree.

>The spec is so rife with them
>that I favor pretty much starting over... with the
>model theory draft. In this model theory, we have
>a fairly ordinary syntax for RDF (whose components are ordinary
>syntactic symbols, though the "anonymous" terms are
>a bit novel).

Anonymous *nodes*, please. They are almost exactly what Frege used 
(they are the 'links' connecting an existential quantifier to the 
term positions it quantifies, in his graphical notation) and also 
what Peirce called 'identities', so the idea is actually very old 
(though not currently fashionable.)

> And in each interpretation of
>an RDF document/formula, we have a domain of discourse
>that might contain mothers, backhoes, etc.
>This is largely consistent with the way RDF has been deployed;
>this is the way people use it and the way the code works.
>It's just an editorial fix.
>
>Regarding (2), the damage is so extensive that I'm
>not sure it's recoverable. The sloppiness in the spec
>has propogated into running code to the extent
>that there's really not much value in changing
>the specification associated with the names
>  http://www.w3.org/1999/02/22-rdf-syntax-ns#subject
>  http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate
>  http://www.w3.org/1999/02/22-rdf-syntax-ns#object
>because the code is already deployed, and we
>might as well make up new names if we're going
>to re-deploy the code.

I didn't intend, when writing the model theory, to *change* the 
meanings associated with these names. My intention was to express 
what the M&S says about their intended meanings as precisely as I 
could. Sorry if it came across as an attempt to set the record 
straight: that wasn't my goal.

What assumptions about those names are made by the deployed code, 
however? Doesn't it assume that they denote the obvious relations 
between a triple and its three components, as the M&S says? That is 
what the model theory assumes. What else could they mean?

>I'm quite happy with the way the draft model theory
>(pretty much all the drafts) deal with (1);
>with regard to (2), the drafts take a sane
>approach, but an approach that is inconsistent
>with practice.

OK, fair enough. My problem now however is that I honestly, with the 
best will in the world and trying hard to be constructive, cannot 
imagine what this other interpretation of reification (that is 
embedded in code and widely adopted, apparently) can possible BE. 
Apparently it is not what the M&S says about reification, so where is 
there any source which can explain what it is?

>Again, I think this is why you were actioned to
>produce a MT draft without reification.

I understood that there was still some feeling that reification 
needed more discussion. I wish we could start having that discussion 
some time soon, and that someone could enlighten me about what RDF 
reification is supposed to mean.

Pat

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Received on Friday, 7 September 2001 11:05:39 EDT

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