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Re: thoughts on metadata

From: Chris Welty <cawelty@gmail.com>
Date: Thu, 27 Mar 2008 07:38:06 -0400
Message-ID: <47EB871E.3000902@gmail.com>
To: Michael Kifer <kifer@cs.sunysb.edu>
CC: Jos de Bruijn <debruijn@inf.unibz.it>, RIF WG <public-rif-wg@w3.org>



Michael Kifer wrote:
> 
> OK. But the more general syntax should then be added to FLD -- to keep us
> honest.
> 
> Also, this still does not address the issue that the meta syntax is not
> accessible to processing by rules.
> 

Let's wait for the next WD for that.

-Chris





>>
>> [1] http://www.w3.org/2005/rules/wiki/Annotations
>>
>>> Here are some concrete problems.
>>>
>>> 1. Meta data can be attached to various parts of the rules, not just rules
>>>    themselves, and this metadata can affect the semantics.
>>>    A simple example is specifying that the output to a query must be sorted.
>>>    This changes the semantics, since the answer is not a set any more
>>>    but a list.
>>>
>>> 2. Some important types of rule systems are based on prioritized defaults
>>>    (defeasible, courteous, preference LP).
>>>
>>>       - Here metadata is part of the syntax and of semantics.
>>>       - Typically metadata consists of rule labels and priority or
>>>         preference information.
>>>       - Metadata items are often *terms with variables* and not just strings.
>>>
>>> 3. The current proposal does not offer any obvious or natural way for the
>>>    metadata to be processable by a (possibly different) rule set.
>>>
>>>    
>>>
>>>
>>> 	--michael  
>>>
>> -- 
>>                           debruijn@inf.unibz.it
>>
>> Jos de Bruijn,        http://www.debruijn.net/
> 
> 

-- 
Dr. Christopher A. Welty                    IBM Watson Research Center
+1.914.784.7055                             19 Skyline Dr.
cawelty@gmail.com                           Hawthorne, NY 10532
http://www.research.ibm.com/people/w/welty
Received on Thursday, 27 March 2008 11:38:44 GMT

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