RE: Expressing Ruleset differences as Meta-information for RIF

Hi Mala,

Thanks for your input.

In response to this message, I have added the following possible design
goal to the list of design goals in the category named "Design Goals
Concerning RIF Supported Metadata Features:"

"The RIF should support meta-level or metadata features which make it
possible to create rule "templates" that capture patterns of semantic
and/or syntactic structures common across two or more rules."

I hope this captures the intent of the use-case you describe.

Allen


  


________________________________

	From: Mala Mehrotra [mailto:mm@pragati-inc.com] 
	Sent: Monday, February 20, 2006 2:42 PM
	To: Ginsberg, Allen; public-rif-wg@w3.org
	Subject: Expressing Ruleset differences as Meta-information for
RIF
	
	
	Hi Allen and RIF members,
	
	         In going through the Design Goals document, I believe
that an important observation regarding capture of meta-information on
rule-sets, (which we had addressed as "Supporting the Reuse of Rules"
use case) has not been included. The last para in section 1 of the
Design Goals document states the following:
	
	
	"Besides representing an order of magnitude less effort for the
implementation of translation algorithms, the use of a RIF has the
potential for additional benefits. For example, in cases where
rule-interchange mappings cannot be reliably automated, the information
provided by the RIF representation should, at the very least, be useful
in automatically constructing explanations of the translation impasse.
	
	It is important to understand, however, that the RIF itself
provides neither a translation algorithm nor an explicit mapping
between rule languages. Rather the RIF includes a framework of
concepts, represented as tags in a markup language, that can be used to
provide information about the meaning of wffs in a rule language. For
rule authors who wish to make their rules accessible across languages
and platforms, the more completely, precisely, and accurately they tag
their creations using the RIF, the more likely it is that their rules
will be capable of being automatically translated correctly."
	
	Our use case focuses on the issue of utilizing RIF tags to
provide meta- information about sets of rules rather than just single
rules. In my experience while analyzing rules, we have repeatedly
encountered common patterns across rule sets in various forms,
regardless of representation and domain that the rules are embedded in.
In the use case cited in the RIF Use Cases and Requirements, we have
shown how that different classes such as, MaritimeEquipmentType,
ElectronicEquipmentType and MiscellaneousEquipmentType have been
similarly defined in OWL. The last block, in the use case,  abstracts
the similarities while providing <slots> which indicate the parts which
are different across the rules. I believe that this type of
meta-information about sets of rules, such as similarity across the
rules, can be usefully exploited by systems that utilize RIF for both
exchange and interoperability of rules. 
	
	Below I provide a similar (but shorter) example from Cyc rules
from the spatial microtheory, that I had analyzed for the DARPA RKF
project:
	
	(#$implies
	(#$and
	(#$termOfUnit ?CONVEXHULLFN (#$ConvexHullFn ?OBJECT))
	(#$termOfUnit ?CONVEXHULLFN-1 (#$ConvexHullFn ?CONVEXHULLFN)))
	(#$equals ?CONVEXHULLFN ?CONVEXHULLFN-1))
	
	(#$implies
	(#$and
	(#$termOfUnit ?INTERIORFN (#$InteriorFn ?OBJECT))
	(#$termOfUnit ?INTERIORFN-1 (#$InteriorFn ?INTERIORFN)))
	(#$equals ?INTERIORFN ?INTERIORFN-1))
	
	
	This is a case of discovering the characteristic of idempotency
across various rules where the functions return the same value
regardless of how many times you invoke it. (termOfUnit in Cyc is like
a macropredicate to store the value returned by a function call.)
	
	It is important to capture such similarity in invocations, at a
meta-level in the RIF language, so that these types of rules can be
invoked in any other language easily and translation process can
proceed en masse. In other words, we need a way to separate out the
commonality in formulation of the rules, from the specific invocations
of these rules, so that these rules can be made more amenable to
transfer across different rule representations.
	
	So far my attempt to abstracting the commonality has been in
the form of templates, by recognizing the idempotent rules found above,
as a UniqueFn, which can invoke the set of rules above by being defined
in the following manner: 
	
	(#$implies
	(#$and
	  (#$<UniqueFn> ?<UNIQUEFN>)
	  (#$termOfUnit ?<UNIQUEFN-TERM-1> (?<UNIQUEFN> ?OBJECT))
	  (#$termOfUnit ?<UNIQUEFN-TERM-2> (?<UNIQUEFN>
?<UNIQUEFN-TERM-1>)))
	  (#$equals ?<UNIQUEFN-TERM-1> ?<UNIQUEFN-TERM-2>))
	 
	Now the exchange across other rule representation languages can
be carried out both at the syntactic level and at a meta-level  and any
number of such rules can be invoked, with different names, in either
one of the languages to be interoperated with.
	
	Thus RIF needs to capture the meta-level formulation of these
rules - and I see a strong role for advocating first order
representation for such cases, so that one can invoke rules on sets of
classes. 
	
	Please note that I am not advocating a first order reasoner (as
that can be a hard problem to tackle in Phase I) - as I am not
executing the meta-rules. However it is important to represent them in
RIF so as to generate other rules. 
	
	I would be happy to discuss this further in tomorrow's telecon
and/or at the F2F in Cannes,
	
	                 Thanks for listening!
	                          Mala
	
	
	
	At 01:20 PM 2/16/2006, Ginsberg, Allen wrote:
	
	


		Dear RIF-WGers,
		
		At the last telecon I was assigned the action item of
starting to
		compile a list of Design Goal issues on the WIKI.  
		
		To view what I have done so far please visit
		http://www.w3.org/2005/rules/wg/wiki/UCR/Design_Goals.
		
		Here is a synopsis: 
		
		I list 3 design goal categories.  Each category has
some explanation of
		what it is, and one or more of the following
		
		        1) a list of possible design goals
		       2) a list of NOT-A-Design-Goals 
		        3) commentary
		        4) questions
		
		My next step is to go back over the messages in the
email list and
		build up these lists and add new categories as
required. I hope to get
		that done before the next telecon.  
		
		Any feedback and suggestions are most welcome.
		
		Allen
		
		
		
		
		
		
	
_______________________________________________________________
		
		Dr. Allen Ginsberg        The MITRE Corporation,
Information Semantics 
		aginsberg@mitre.org       Center for Innovative
Computing & Informatics
		
		Voice: 703-983-1604       7515 Colshire Drive, M/S H305

		Fax:   703-983-1379       McLean, VA 22102-7508, USA 
		  


	Mala Mehrotra
	Pragati Synergetic Research Inc.  MS 19-46Q, NASA Research
Park, Moffett Field, CA 94035
	Voice:
	(650)-625-0274(Office)
	(408)-861-0939 (Home Office) 
	(408)-910-4115 (Cell)
	Fax: (408)-516-9599 
	URL: http://www.pragati-inc.com                   
	Email: mm@pragati-inc.com

Received on Monday, 20 February 2006 20:02:13 UTC