Re: [RIFWG] [Requirements?] A vision for the RIF

Michael Kifer wrote:
>> Michael Kifer wrote:
>>     
>>> I said that normative rules imply that we must use some sort of a closed
>>> world assumption. Under the open-world assumption there is no useful way to
>>> distinguish between normative rules and deductive rules, but under the CWA
>>> there is.
>>>   
>>>       
>> I am not sure I can agree with this. I can very well imaginbe normative
>> rules not governed by a Closed World Assumption.
>>     
>
> Francois,
>
> The above must be taken in the context of my earlier message
> http://lists.w3.org/Archives/Public/public-rif-wg/2006Mar/0161.html
> where I *proved* that the rule set for which those normative rules act as
> constraints must have some sort of closed world assumption (more precisely,
> cannot use the normal first-order semantics).
>   

I must say that "proved" is a bit strong here.  You have used in your 
argument a particular definition of constraint that infallibly leads to 
your conclusion.  For those indoctrinated in the logical school (to 
paraphrase your term), a constraint can just be an axiom and 
satisfiability the test.  This is not to say one is right or wrong, just 
that your argument constitutes no proof.

> I did not say that normative rules must be "governed" by CWA, because I
> don't know what this might mean.
>
> If you think that my very short proof has a bug then please point this out.
>
>
>
> 	--michael  
>
>
>
>
>   


-- 
Dr. Christopher A. Welty                    IBM Watson Research Center
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