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RE: Datatypes

From: Smith, Michael K <michael.smith@eds.com>
Date: Thu, 15 May 2003 10:58:07 -0500
Message-ID: <B8E84F4D9F65D411803500508BE322141605050E@USPLM207>
To: Jeremy Carroll <jjc@hpl.hp.com>, www-webont-wg@w3.org

Added to issues list

-----Original Message-----
From: Jeremy Carroll [mailto:jjc@hpl.hp.com] 
Sent: Tuesday, May 13, 2003 1:57 PM
To: www-webont-wg@w3.org
Subject: Re: Datatypes 




So I just tried to work out what the right answer is ...
(Contrast the stuff on datatypes and consistency checkers in
http://lists.w3.org/Archives/Public/www-webont-wg/2003May/0168.html
and
http://lists.w3.org/Archives/Public/www-webont-wg/2003May/0185.html
)

Following observations
1) The issue list should have a link from issue 5.8 datatypes to
http://lists.w3.org/Archives/Public/www-webont-wg/2003Mar/0087.html

since it is highly relevant to the issue 
and to the minute
http://lists.w3.org/Archives/Public/www-webont-wg/2003Mar/0132.html

2) S&AS section 3 does not seem to agree with
http://lists.w3.org/Archives/Public/www-webont-wg/2003Mar/0087.html

[[LATER
Ahh but
http://lists.w3.org/Archives/Public/www-webont-wg/2003May/0121.html
is really quite helpful in bridging the gaps.
]]

resolution text
[[
These datatypes would be interpreted by an OWL reasoner
   in the same manner as unrecognized datatypes, i.e., lexically identical
   literals would be equal and lexically different literals would not be
   known to be either equal or unequal.

   This is essentially Part G of the OWL DL Syntax that was approved today.
   I have expanded the explanation of the proposal slightly and allowed
   unrecognized datatypes into OWL Full as well.
]]

WD text
[[
VD, the datatype names of a vocabulary, contains the URI references for the 
built-in OWL datatypes and rdfs:Literal.
...
An Abstract OWL interpretation with respect to T with vocabulary VC, VD, VI,

VDP, VIP, VAP, VO is a tuple of the form: I = <R, EC, ER, L, S> where (with
P 
being the power set operator) 
...
EC : VD -> P(LVT) 
]]

i.e. an abstract OWL interpretation gives the class extension as a set of 
literal values for every built in datatype.

The whole of this section gives no interpretation in which datatypes are not

recognised or not supported, and does not follow the intent, as I read it,
of 
the resolution.

Maybe I have misunderstood - I am open to being spoonfed the reading which 
fits with the resolution.

I guess I retract the proposed text in:
http://lists.w3.org/Archives/Public/www-webont-wg/2003May/0168.html
in which I was trying to follow S&AS section 3.

I would suggest that the notion of unsupported datatypes should be made 
explicit.

(Trying to unpack the datatype theory in section 5 is worse - I hit:
[[
 (The specifics of datatype theories used here differ slightly from those in

the RDF semantics currently under review. It is expected that these 
discrepancies will be resolved during last call, following which this 
document will be revised to correspond directly to RDF datatyping.)
]]
and then wonder if need to go and look at the latest editors draft of the
RDF 
Semantics to get a feel for what's going on)


(Note it seems disingenious of Peter, while logically correct, to say that 
S&AS does not say that rdfs:Literal is a datatype URI - S&AS does call it a 
"datatype name of a vocabulary")

Jeremy
Received on Thursday, 15 May 2003 11:58:42 GMT

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