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Re: RDF Semantics: two issues, connected to OWL

From: <herman.ter.horst@philips.com>
Date: Thu, 18 Dec 2003 12:59:27 +0100
To: pat hayes <phayes@ihmc.us>
Cc: connolly@w3.org, sandro@w3.org, www-rdf-comments@w3.org
Message-ID: <OFF7719114.57388A66-ONC1256E00.003B2735-C1256E00.0041E940@diamond.philips.com>

Could it be that the PR version of RDF Semantics is not the
proper version?
It seems that some changes that you describe below are not
in the document.  See below.
(I could not check this with an earlier version of the
document; the editorial version was not updated when you wrote
your last mail, and there was no pointer to new document text
in your last mail.)

>>[...]
>>
>>>>
>>>>Issue 1- It seems that two changes made to RDF Semantics
>>>>during LC2 have not yet been incorporated completely
>>>>in the definition of D-interpretations.
>>>
>>>As already remarked in earlier messages: that I regard as a typo, and
>>>plan to get it changed before final publication , if the process will
>>>allow it.
>>
>>Without going into the meaning of the word typo, I would only like
>>to note for clarity that I added two changes in my previous message,
>>to the change about which you remarked in [5] that you regard it as a
>>typo.
>
>If I regard it as a typo, then I can consider the change to be editorial 
:-)
>
>I have made those changes to the final version of the document, 

Unlike the last statement suggests, I cannot find the "two changes" 
that I mentioned above, from [1], in the document dated 15 December.
These two changes were left over as part of changes from LC2 that 
were not yet complete:
1) the omission of the terminology "from V" as opposed to "in V" and 
2) the change not to require all possible literal values in LV
- these changes are not yet incorporated in the definition of 
D-interpretations.
For example, line 1 of the definition would need change as follows:
--if <aaa,x> is in D then [aaa in V and] I(aaa)=x

However, instead of making such local changes to the definition,
I suggested to implement these changes by editorially rewording 
the definition of D-interpretations so that it is more obvious 
that the XMLLiteral conditions, from Section 3 (i.e. two RDF 
semantic conditions) and Section 4 (i.e. two RDFS axiomatic triples), 
form a special case. 
As I pointed out in [1], this would enable a generalization of the 
RDFS entailment lemma to include datatypes.  Even though such a 
generalized 
lemma is not in the RDF Semantics document, it could become useful.
I included a suggestion for such a rewording in [1]:

HtH>Given a datatype map D and a vocabulary V, a D-interpretation
>of V is an rdfs-interpretation of V such that for all
><a,d> in D we have:
>- a in V and I(a) = d
>- I satisfies the triples
>    a type Datatype
>    a subClassOf Literal
>- if l=s^^a is a typed literal in V and s in L(d),
>  then IL(l)=L2V(d)(s) in LV  and  <IL(l),d> in IEXT(I(type))
>- if l=s^^a is a typed literal in V and s not in L(d),
>  then IL(l) not in LV  and  <IL(l),d> not in IEXT(I(type)




PatH>as 
>well as inserting the required 'extra' rule (christened rule gl and 
>defined immediately after rule lg in the document, with a short 
>explanation) and other small modifications as required in the rdfs 
>entailment lemma proof.
>
>

Remark: 
it seems that the editorial work is not yet entirely complete, as
the two statements of the RDFS entailment lemma differ.
The appendix version does not yet include gl in its statement.



Herman

[1] 
http://lists.w3.org/Archives/Public/www-rdf-comments/2003OctDec/0233.html
Received on Thursday, 18 December 2003 07:00:08 GMT

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