[RIF]: Expressing Ruleset differences as Meta-information for RIF

Allen - I must admit my interpretation of Mala's comment was somewhat
different: that there is information regarding intent / use of rules
associated with rulesets that may be of value to be defined in RIF for
traceability / assistance with transformations. This "metadata" may be:

- there may be several rules leading to the same conclusion

- these rules are effective for a certain context

- these rules are designed for a particular semantics (/processing
engine class)

 

I would guess that until such metadata is proven to be required for
interchange, it is out of scope. However, it is intriguing enough for
possible addition to the use cases: requirements for rule metadata.

 

PS: I would have thought that templates (of anything including rules)
were an orthogonal concept. I've no idea if any existing W3C technology
eg RDF already has explicit support for templates. You could of course
argue that XSL is ako "template" for XML, etc.

 

Cheers,

 

Paul Vincent

Fair Isaac Blaze Advisor --- Business Rule Management

OMG Standards for Business Rules, PRR & BPMI

mobile: +44 (0)781 493 7229 ... office: +44 (0)20 7871 7229 

 

 

-----Original Message-----
From: public-rif-wg-request@w3.org [mailto:public-rif-wg-request@w3.org]
On Behalf Of Ginsberg, Allen
Sent: Monday, February 20, 2006 8:02 PM
To: Mala Mehrotra; public-rif-wg@w3.org
Subject: 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