W3C home > Mailing lists > Public > w3c-rdfcore-wg@w3.org > November 2002

Re: Some semantics comments - more later.

From: pat hayes <phayes@ai.uwf.edu>
Date: Sat, 9 Nov 2002 21:58:24 -0600
Message-Id: <p05111b04b9f36bd9a498@[10.0.100.86]>
To: Jeremy Carroll <jjc@hpl.hp.com>
Cc: fmanola@attbi.com, w3c-rdfcore-wg@w3.org

>Some more important ones first:

Apart from where noted below, all suggested changes now done in
http://www.coginst.uwf.edu/~phayes/RDF_Semantics_latest.html.

>===
><<
>3.4 Datatyped Interpretations
>
>Suggest-delete:
>[[We will assume that ]] A datatype is defined by
>a uriref and [[suggest-delete: itself]] defines ..
>>>
>
>Next paragraph on XMLLiteral - delete it all.
>My section in concepts is better and clearer,
>(IMHO!)

I agree.

>given that, there is no need to talk about these
>at all in the Semantics.

I need to be able to refer to the things in the value space of that 
datatype, because I want to say what they denote in Lbase. What are 
they? XML documents??

>
>Next paragraph:
>... A 'datatype-aware' RDF engine should be competent
>to recognize the
><suggest-add:
><a href="http://www.w3.org/TR/rdf-concepts#section-XMLLiteral">
>rdfs:XMLLiteral
>
>(Note I am not online and have probably got the fragID wrong).

Damn right, it is http://www.w3.org/tr/rdf-concepts#xtocid103643  :-)

All above done.

Ive also tuned the MAY/MUST/SHOULD language here and there, you MAY 
wish to take another look at it in the new version.

>======
>
>Section 4, should largely be informative, in case of errors,

Good point.

>the other sections should take precedence.
>I suggest one of two fixes:
>My preference is:
>
><<suggest new heading>>
>4.1 RDF-entailment and RDF closures (informative)
><<suggest new heading>>
>4.2 RDFS-entailment and RDFS closures (informative)
><<suggest new heading>>
>4.3 Datatype entailments
>
>Linked with this edit I would
><<suggest new heading>>
>Appendix C: Translation into Lbase (informative)
>
><<suggest-delete, from introduction 0.1>>
>[[We believe that the two ... normative.]]
>
>alternatively
>In the introduction in section 0.1
>suggest-change
>[[
>We believe that both these descriptions,
>and also the closure rules of section 4,
>are all in exact correspondence, but only
>the direct model theory ...
>]]
>
>
>==========
>
>Abstract
>suggest-change
>... RDF and RDFS, with some entailment results. It ...
>
>
>=======
>
>0.1 typo
>[[reserver truth]]=>[[preserve truth]]
>
>======
>**sorry fragids missing****
>0.2 Graph Syntax
>Suggest delete 1st two paras
>[[Any semantic theory ...
>set containing that triple]]
>
>New text:
>[[[[[
>This semantic theory is attached to the abstract
>syntax of RDF [RDF_CONCEPTS].
>We use the following terminology defined there:
>+ uriref, defined as
><a href="http://www.w3.org/TR/rdf-concepts#section-??
>>
>RDF URI Reference
>+ 
><a href="http://www.w3.org/TR/rdf-concepts#section-??
>>
>literal
>+ 
><a href="http://www.w3.org/TR/rdf-concepts#section-??
>>
>plain literal
>+ 
><a href="http://www.w3.org/TR/rdf-concepts#section-??
>>
>typed literal
>+ 
><a href="http://www.w3.org/TR/rdf-concepts#section-??
>>
>blank node
>+ 
><a href="http://www.w3.org/TR/rdf-concepts#section-??
>>
>triple
>

Done, but I have to say I preferred my own definitions to the ones in 
there, particularly of node and graph.

>]]]]
>
>Continue with [[The convention that ...]]
>
>========
>
>1.3 Assertions, meanings and inference
>
>suggest-add
>[[Editor's note: further work on the overlap with
>RDF_CONCEPTS is needed here.]]
>
>(sorry I am not sufficiently on top of the
>assertion issue to help)

Graham has already asked for much of this section to be deleted. I 
plan to just keep the first paragraph and remove the rest for now 
(some of the disclaimer pieces have been incorporated into the list 
of what-we-arent-doing-here in the very first intro in 0.1),
then that para is just a technical intro for the next section. Ive 
rewritten it as follows:
------
The basic intuition of model-theoretic semantics is that asserting a 
sentence makes a claim about the world: it is another way of saying 
that the world is, in fact, so arranged as to be an interpretation 
which makes the sentence true. In other words, an assertion amounts 
to stating a constraint on the possible ways the world might be. 
Notice that there is no presumption here that any assertion contains 
enough information to specify a single unique interpretation. It is 
usually impossible to assert enough in any language to completely 
constrain the interpretations to a single possible world, so there is 
no such thing as 'the' unique RDF interpretation. In general, the 
larger an RDF graph is - the more it says about the world - then the 
smaller the set of interpretations that an assertion of the graph 
allows to be true - there are fewer ways the world could be, while 
making the asserted graph true of it.
-------



>
>===
>
>Section 0.1
>suggest-replace
>[[See @@Jeremy ...discussion.]]
>with
>[[NOTE: This may duplicate material in RDF Concepts,
>more editorial work is needed]]

I have just put a straight reference to your doc here. We can 
rewrite.remove this altogether before final call.

>
>===
>
>Section 0.1
>
>Suggest insert one word:
>[[..same semantic theory: directly, and also (in an
>**informative** appendix) an 'axiomatic semantics'..]]
>
>Suggested Lbase ref:
>
>Lbase, Hayes and Guha, in preparation.

Got one, S'OK. NOt in yet, the @@ is a warning to me.

>
>===
>
>Global replace untyped with plain
>
>===
>Global search for the word labelled - it is always an error.

Moving from UK English to US English fried my spelling circuitry, I'm 
afraid. My software (Eudora and Wurd) accepts both versions for 
labelling labeled nodes. But done.

>
>===
>
>0.2 Graph Syntax
>
>[[We refer to urirefs and literals]]
>suggest:
>[[We refer to urirefs and typed literals]]

That whole paragraph is gone, it was left over by mistake from an 
older version. Defs are now in next section.

>
>[[
>In the interests of brevity, we use
>the imaginary URI prefix 'ex:'
>]]
>=>
>
>[[
>In the interests of brevity, we use
>the imaginary URI scheme 'ex:'
>]]
>
>Suggest-delete-para:
>[[However, the reader is cautioned that this Qname convention..
>orthographic convenience.]]
>
>===
>
>1.2  Urirefs, resources and literals.
>
>1st para:
>[[The meaning of a literal is <<suggest-add: principally>> determined ]]]
>
>****

Apart from as noted, all above is now done.

>
>out of time, I have more, but you will have to wait.

OK, I'm all awaiting.

Can I suggest you also scan through

http://www.coginst.uwf.edu/~phayes/RDF_Semantics_latest.html

to see how its shaping up? That way you save emailing me about things 
Ive already fixed. I think I have most all of the details in the RDFS 
tables right in that version, for example, and there are a few little 
cleanups in the closure rules, things like that. Ive rewritten the 
definition of 'merge' to be slightly more careful about 
'isomorphism'. The Lbase axioms need bringing into line with the 
rest, that's not done yet but is routine.  Also I need to mention 
rdf:value if only to say its meaningless, so that still needs to go 
in.  Also I need to re-draw the second figure, that will have to wait 
until tomorrow.

There is 1 nasty problem I currently know about and am wrestling 
with.  The proof of the RDFS closure lemma is now not correct (since 
we changed the subClass/Property conditions to IFF) and I need to 
find a way to write out the proof better. SO that is hanging in the 
current version. If I can't this done over the weekend I will just 
weaken the statement of the lemma and put in a small note about it 
for now, as I need to use Monday for all the copy-editing detail and 
linking and refs and so on that needs doing.

Pat

-- 
---------------------------------------------------------------------
IHMC					(850)434 8903   home
40 South Alcaniz St.			(850)202 4416   office
Pensacola              			(850)202 4440   fax
FL 32501           				(850)291 0667    cell
phayes@ai.uwf.edu	          http://www.coginst.uwf.edu/~phayes
s.pam@ai.uwf.edu   for spam
Received on Saturday, 9 November 2002 22:58:11 EST

This archive was generated by hypermail pre-2.1.9 : Wednesday, 3 September 2003 09:54:03 EDT