W3C home > Mailing lists > Public > public-rif-wg@w3.org > November 2007

Re: extensibility -> pxfim

From: Gary Hallmark <gary.hallmark@oracle.com>
Date: Wed, 07 Nov 2007 12:58:43 -0800
Message-ID: <47322703.7050102@oracle.com>
CC: public-rif-wg@w3.org

Speaking pragmatically, I'd say the following:

A RIF Document contains metadata tags and language tags that describe 
and define rules.  Metadata tags occur only within the <metadata> 
element of a RIF Document.
For forward compatibility, a RIF System may ignore unknown tags using a 
trim-to-fit strategy.   Trimming metadata tags never impacts the 
entailment (meaning) of the rules.  Trimming language tags almost always 
does change the entailment of the rules. 

In some cases, e.g. monotonic rule sets, it is possible to work out 
whether the entailment is larger or smaller than it should be.  Removing 
a rule or a disjunct from a monotonic rule set may reduce the 
entailment.  Removing a conjunct may increase the entailment.

A RIF System should warn the user when ignoring tags, and further warn 
about possible entailment changes when ignoring language tags.

And that's pretty much all I think we need to do for extensibility at 
present.

Paul Vincent wrote:
> While I agree with Michael that from a pragmatic point of view, and
> especially for an operational rule system, the only usual fallback will
> be a rejection, the idea of a generic extensibility mechanism for XML
> seems to make a lot of sense.
>
> So +1 to Michael (its probably not really a RIF version 1 issue)
> And +1 to Sandro (its probably solving a wider content mgmt related
> problem in a standard way).
>
> Paul Vincent
> TIBCO | ETG/Business Rules 
>  
>
>   
>> -----Original Message-----
>> From: public-rif-wg-request@w3.org
>>     
> [mailto:public-rif-wg-request@w3.org]
>   
>> On Behalf Of Michael Kifer
>> Sent: 07 November 2007 18:28
>> To: Sandro Hawke
>> Cc: public-rif-wg@w3.org
>> Subject: Re: extensibility -> pxfim
>>
>>
>>
>>
>> I doubt that such a general theory alone would be more useful for RIF
>>     
> than
>   
>> a
>> simple policy of rejecting documents that have new tags. It could be
>> useful as an XML framework for fallback mechanisms, but then the hard
>>     
> part
>   
>> would be to figure out how to specialize it for RIF and make it do
>> something non-trivial.
>>
>> Of course, this is just my general feeling. It is based only on the
>> understanding that the problem is very hard.
>>
>> But divesting RIF from the responsibility of doing something in this
>> respect is a very tempting proposition :-)
>>
>> 	--michael
>>
>>
>>     
>>> I'm trying to understand whether it makes sense to factor the
>>> extensibility mechanism out of RIF entirely.
>>>
>>> As sort of a trial balloon, I've given it a name and thrown together
>>>       
> a
>   
>>> skeletal editor's draft, so we can point non-RIF folks at it.
>>>
>>>    http://www.w3.org/2007/11/pxfim/
>>>
>>> I have no idea at this point where this document will go.  It might
>>>       
> well
>   
>>> be discarded as silly, if no one outside of RIF is
>>>       
> motivated/interested.
>   
>>> But if there is enough interest from outside of RIF, it might
>>>       
> continue
>   
>>> and RIF might be able to divest itself of this technical work.
>>>
>>>       - Sandro
>>>
>>>
>>>       
>>     
>
>
>   

-- 


Oracle <http://www.oracle.com>
Gary Hallmark | Architect | +1.503.525.8043
Oracle Server Technologies
1211 SW 5th Avenue, Suite 800
Portland, OR 97204
Received on Wednesday, 7 November 2007 20:59:09 GMT

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