W3C

/* =oClassNames.length); i++){ /*>*/ arrRegExpClassNames.push(new RegExp("(^|\s)" + oClassNames[i].replace(/\-/g, "\-") + "(\s|$)")); } } else{ arrRegExpClassNames.push(new RegExp("(^|\s)" + oClassNames.replace(/\-/g, "\-") + "(\s|$)")); } var oElement; var bMatchesAll; for(var j=0; !(j>=arrElements.length); j++){ /*>*/ oElement = arrElements[j]; bMatchesAll = true; for(var k=0; !(k>=arrRegExpClassNames.length); k++){ /*>*/ if(!arrRegExpClassNames[k].test(oElement.className)){ bMatchesAll = false; break; } } if(bMatchesAll){ arrReturnElements.push(oElement); } } return (arrReturnElements) } function set_display_by_class(el, cls, newValue) { var e = getElementsByClassName(document, el, cls); if (e != null) { for (var i=0; !(i>=e.length); i++) { e[i].style.display = newValue; } } } function set_display_by_id(id, newValue) { var e = document.getElementById(id); if (e != null) { e.style.display = newValue; } } /*]]>*/RIF Use Cases and Requirements (Second Edition)

W3C Working Draft 18 December 2008Group Note 5 February 2013

This version:
http://www.w3.org/TR/2008/WD-rif-ucr-20081218/http://www.w3.org/TR/2013/NOTE-rif-ucr-20130205/
Latest version:
http://www.w3.org/TR/rif-ucr/
Previous version:
http://www.w3.org/TR/2008/WD-rif-ucr-20080730/http://www.w3.org/TR/2008/WD-rif-ucr-20081218/
Editors:
Adrian Paschke, Free UniversityFreie Universitaet Berlin
Leora Morgenstern, SAIC
David Hirtle, National Research Council Canada
Allen Ginsberg, Mitre
Paula-Lavinia Patranjan, REWERSE
Frank McCabe, Fujitsu

A color-coded version of this document showing changes made since the previous version is also available.

This document is also available in these non-normative formats: PDF version.


Abstract

This document, developed by the Rule Interchange Format (RIF) Working Group, specifies use cases and requirements for the W3C Rule Interchange Format, a family of rule interchange dialects that allows rules to be translated between rule languages and thus transferred between rule systems.

Status of this Document

May Be Superseded

This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at http://www.w3.org/TR/.

This document is being published as one of a set of 513 documents:

  1. RIF Overview (Second Edition)
  2. RIF Use Cases and Requirements (Second Edition) (this document)
  3. RIF Core Dialect (Second Edition)
  4. RIF Basic Logic Dialect (Second Edition)
  5. RIF Production Rule Dialect (Second Edition)
  6. RIF Framework for Logic Dialects (Second Edition)
  7. RIF Datatypes and Built-Ins 1.0 (Second Edition)
  8. RIF Production Rule DialectRDF and OWL Compatibility (Second Edition)
  9. OWL 2 RL in RIF (Second Edition)
  10. RIF Combination with XML data (Second Edition)
  11. RIF In RDF (Second Edition)
  12. RIF Test Cases (Second Edition)
  13. RIF Primer (Second Edition)

Summary of Changes

The changes are relatively localized,document was reorganized, sections were re-written, and are visible inan analysis was added of how the color-coded "diff" . Please Commentuse cases are addressed by 23 January 2009the Rule Interchange Format (RIF) Working Group seeks public feedback on these Working Drafts.current RIF specifications.

Please Send Comments

Please send yourany comments to public-rif-comments@w3.org (public archive). If possible, please offer specific changes to the text that would address your concern. You may also wish to check the Wiki Version ofAlthough work on this document for internal-reviewby the Rule Interchange Format (RIF) Working Group is complete, comments and changes being drafted whichmay address your concerns.be addressed in the errata or in future revisions. Open discussion among developers is welcome at public-rif-dev@w3.org (public archive).

No Endorsement

Publication as a Working DraftGroup Note does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.

Patents

This document was produced by a group operating under the 5 February 2004 W3C Patent Policy. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.



Table of Contents

1 Introduction

Rule-languages and rule-based systems have played seminal roles in the history of computer science and the evolution of information technology. From expert systems to deductive databases, the theory and practice of automating inference based on symbolic representations has had a rich history and continues to be a key technology driver.

Due to the innovations made possible by the Internet, the World Wide Web, and, most recently, the Semantic Web, there is now even greater opportunity for growth in this sector. While some of these opportunities may require advances in research, others can be addressed by enabling existing rule-based technologies to interoperate according to standards-based methodologies and processes. The basicprimary goal of the Rule Interchange Format (RIF) Working Group ishas been to devise such standards and make sure that they are not only useful in the current environment, but are easily extensible in order to deal with the evolution of rule technology and other enabling technologies. ThisRIF's mission of RIFis part of W3C's larger goal of enabling the sharing of information in forms suited to machine processing:

    1. Rules themselves represent a valuable form of information for which there is not yet a standard interchange format, although significant progress has been made within the RuleML Initiative and elsewhere.
    2. Rules provide a powerful business logic representation, as business rules, in many modern information systems.
    3. Rules are often the technology of choice for creating maintainable adapters between information systems.
    4. As part of the Semantic Web architecture, rules can extend or complement the OWL Web Ontology Language to more thoroughly cover a broader set of applications, with knowledge being encoded in OWL or rules or both.

The purpose of this RIF-UCR document is to provide a reference todescribe the use cases that guided the design of RIF and a guide for users and implementersto document the current technical specificationsdesign requirements that were derived from both the use cases and from the basic goals of RIF dialects.RIF. RIF-UCR also delivers a structured context for formulating future technical specifications of further RIF dialects. Each dialect targets ata cluster of similar rule languages and enables platform-independent interoperation between them (via interchange of RIF rules). The presenteduse cases presented illustrate some of the principal ways in which RIF can provide benefits. RIF can promote innovation and development by fostering collaborative work and providing new opportunities for third-party services. RIF can promote e-commerce by providing interoperability across vendor platforms. RIF can promote efficient process management through reuse, sharing, and the ability to provide unified views across disparate platforms. Last, but not least,Finally, RIF can promote the growth of knowledge by enabling reasoning with merged sets of rules originating from disparate knowledge sources.

The RIF-UCR document is structured as follows: Section 2 formulates the overall goals of RIF and several accordant critical success factors forRIF. Section 3 summarizes the released RIF dialects and the currentstructure of RIF. Section 4 discusses several important requirements for RIF dialects. Section 5 presents a set of use cases that are representative of the types of application scenarios that RIF is intended to support. Besides illustratingThe use cases illustrate the utilization of the current RIF dialects,dialects. More importantly, the functionality specified in the use cases, together with the inferred requirements, actsrequirements discussed in the previous section, serves as input for both the technical specification offor future RIF dialects and forthe implementation of various variants of these scenarios by RIF-compliant applications or systems that incorporate the existing or newly developed RIF technical specifications. In section 5 several important requirements for RIF are inferred from the goalsand use cases.systems.

Although in this document the main alldiscussion of requirements should have aprecedes the discussion of use case or derivationcases, the development of athe use case from which they are derived.cases preceded, and in exceptional circumstancesfact motivated, the development of the requirements. For the most part, requirements maywere not be derived fromestablished unless there was at least one use case, or straightforward modification of a use case, e.g. when theyfrom which that requirement could be derived. There are some exceptions to this rule: for example, some requirements were already defined as constraints in the working group charter. Theircharter and were not necessarily derived from any specific use case. The fulfillment of such requirements is discussed with respect to the existing RIF dialects.

2 GoalsNote that in fact not all use cases can be represented in a straightforward manner within all RIF dialects. In particular, several use cases cannot be represented within the primary goalRIF dialect BLD . This is due first, to the fact that BLD is strictly less expressive than first-order logic (since negation is not expressible), and second, to the fact that some use cases are most naturally represented in languages more powerful than first-order logic, such as modal logics. Some use cases that cannot be represented within BLD can be represented within the RIF dialect PRD, which includes the construct of negation as failure. Following the presentation of each use case in Section 5 is a note indicating in which of the current RIF dialects a use case can be represented naturally, sometimes accompanied by discussion.

It should be noted that even for use cases which cannot be represented in a straightforward manner within some RIF dialect, there may be other approaches that would enable representation. For example, although epistemic operators such as Know and Believe are most straightforwardly represented within a modal logic, it is generally possible to represent such operators in a first-order logic using a possible-worlds semantics. For certain use cases which cannot be naturally represented within some dialect, the extent to which this can be done will be discussed.


2 Goals

RIF is primarily intended to be an effective means of exchanging rules that has the potential to be widely adopted in industry and that is consistent with existing W3C technologies and specifications.

2.1 Exchange of Rules

The primary goal of RIF is to facilitate the exchange of rules.

2.2 Consistency with W3C specifications

RIF is intended to be a W3C specification that builds on and further develops the existing range of specifications that have been developed by the W3C. This implies that existing W3C technologies should fit well with RIF.

2.3 Widescale Adoption

It is an explicit goal of the W3C that the Rules Interchange FormatRIF will have the maximummaximal potential for widescale adoption. Rules interchange becomes more effectiveThe wider the adoption there isof the specification --specification, the more effective rule interchange becomes. This is known as the so-called"network effect".effect."

These goals, along with the use cases in the next section, these goalsSection 5, motivate the requirements in Section 5.4.

3 Structure of RIF

RIF is described by a set of documents, each fulfilling a different purpose,purpose and catering to apossibly different audience. Currently the following set of documents has been released: The RIF-FLD (Framework of Logic Dialects) document describes a framework of mechanisms for specifyingaudiences. The syntax and semantics of logic-basedthree RIF dialects through a numberthat are part of generic concepts.the RIF-RDF+OWL (RIF RDFW3C recommendation and OWL Compatibility) document specifies the interoperation betweenthat can be used to represent RIF and the data and ontology languages RDF, RDFS, and OWL. The RIF-DTB (Data Types and Builtins) document describesuse cases are:

Along with these three dialects, RIF includes related documents: RIF Framework for Logic Dialects, RIF Datatypes and Built-Ins 1.0, RIF Test Cases, RIF RDF and Requirements) document describesOWL Compatibility, RIF Use Cases and Requirements for, OWL 2 RL in RIF The RIF-Test (Test Cases) document describes the test cases developed by, rdf:PlainLiteral, RIF Combination with XML data, RIF Primer, and RIF In RDF. For an overview of RIF, see the RIF working groupOverview.

RIF is designed as a family of RIF dialects as shown in the following Venn diagram:

Venn Diagram of RIF Dialects

Each dialect is a collection of components that workswork together, forming an interlingua. New dialects are needed whenfor those cases in which no existing dialect provides the required rule-language features for interchange.

The RIF Framework for Logic-based Dialects (RIF-FLD) describes mechanisms for specifying the syntax and semantics of logic-based RIF dialects through a number of generic concepts. EveryIn general, a logic-based RIF dialect should specialize these general mechanisms or justify why it does not.mechanisms; justifications should be provided for cases where this is not done. This specialization may include leaving out some elements of RIF-FLD,RIF-FLD in order to produce itsa dialect's concrete syntax and model-theoretic semantics. Currently,The first two existingRIF dialects that are part of the W3C RIF recommendation are RIF Basic Logic Dialect (RIF-BLD)(RIF-BLD), which is fully specified using RIF-FLD, and theRIF Production Rules Dialect (RIF-PRD)(RIF-PRD), which is a partial specialization of FLD.partially specified using RIF-FLD and supplemented by an operational semantics.

RIF-BLD (Basic Logic Dialect) is a specialization of RIF-FLD capable of representing definite Horn rules with equality and enhanced with a number of syntactic extensions to support expressive features such as objects and frames, internationalized resource identifiers (IRIs) as identifiers for concepts, and XML Schema data types.

RIF-PRD (Production Rules Dialect) specifies a production rules dialect to enable the interchange of production rules. The condition language of RIF PRDRIF-PRD is defined in Core as a common subset of RIF BLDRIF-BLD and RIF PRD.RIF-PRD.

RIF-Core (Core Dialect) specifies a common subset of RIF-BLD and RIF-PRD whichthat includes RIF-DTB.

The normative syntax for RIF dialects is a concrete XML syntax. A non-normative presentation syntax is additionally specified for each dialect,dialect to allow a more easily readable and compact presentation of language fragments (such as examples).

4 Requirements

The goals and use cases motivate a use case maynumber of requirements for a Rule Interchange Format. The Working Group has approved the following requirements:

4.1 Implementability

RIF must be consideredimplementable using well understood techniques, and should not require new research in, e.g., algorithms or semantics in order to be a description ofimplement translators.

4.2 Semantic precision

RIF-Core must have a problemclear and precise syntax and semantics. Each standard RIF dialect must have a solutionclear and precise syntax and semantics that utilized anextend RIF-Core.

4.3 Extensible Format

It must be possible to create new RIF dialects that extend existing dialects (thus providing backward compatibility) and are handled gracefully by systems which support existing dialects (thus providing forward compatibility).

4.4 Translators

For every standard RIF dialect or requires the specification of a new one.it is intended that the use cases presented here include the widestmust be possible number of requirements using as few use cases as possible. The included usage scenarios are meantto be representative, meaningimplement translators between rule languages covered by that dialect and RIF without changing the general concepts are commonrule language.

4.5 Standard components

RIF implementations must be able to many possibleuse cases across a broad array of rule-based application domainsstandard support technologies such as XML parsers and industrial sectors. Nearly fifty use cases documenting the need for a RIF were originally submitted by the working group members. These were grouped into general categoriesother parser generators, and then synthesized as much asshould not require special purpose implementations when reuse is possible.

The following use case descriptions, guided by this synthesis, provide scenarios that motivate the current design4.6 Rule language coverage

Because of RIF, explainthe benefitsgreat diversity of a RIF, and guide usersrule languages, no single interchange language is likely to its currently specified dialects. The use cases are also intendedbe able to provide an ongoing reference point for the working group in its goalbridge between all. Instead, RIF provides dialects each of providingwhich targets a precise setcluster of requirements for a RIF and in developing newsimilar rule languages. RIF dialects. Whenever possible, we will give concrete illustrationsmust allow intra-dialect interoperability, i.e. interoperability between semantically similar rule languages (via interchange of how the existing twoRIF dialects (Core, BLD,rules) within one dialect, and PRD) address various aspects of these use cases. The button below can be used to show or hideshould support inter-dialect interoperability, i.e. interoperability between dialects with maximum overlap.

4.7 Compliance model

The RIF examples. Editor's Note: the given examples and used presentation syntax in this version of the UCR working draft are still under development In order to enhance readabilityspecifications must provide clear conformance criteria that define what is and avoidwhat is not a conformant RIF implementation.

4.8 Default behavior

RIF must specify at the appearanceappropriate level of syntactic prejudice, wedetail the default behavior that is expected from a RIF compliant application that does not have deliberately avoidedthe usecapability to process all or part of formal notation in representingthe rules described in these use cases. Instead, we will use thea RIF presentation syntax (of thedocument, or it must provide a way to specify such default behavior.

4.9 Different semantics

RIF dialects). 4.1 Negotiating eBusiness Contracts Acrossmust cover rule Platforms This use case illustrates a fundamental uselanguages having different semantics.

4.10 Limited number of RIF: to supplydialects

RIF must have a vendor-neutral representation of rules, so that rule-system developers and stakeholders can do their work and make product investments without concern about vendor lock-in,standard core, and in particular without concern thata business partner does not have the same vendor technology. It also illustrates the factlimited number of standard dialects based upon that core.

4.11 Embedded comments

RIF canmust be usedable to foster collaborative work. Each developerpass comments.

4.12 Embedded metadata

RIF must support metadata such as author and stakeholder can make a contribution torule name.

4.13 OWL data

RIF must cover OWL knowledge bases as data where compatible with RIF semantics.

4.14 RDF data

RIF must cover RDF triples as data where compatible with RIF semantics.

4.15 Dialect Identification

The joint effort without being forced to adoptsemantics of a RIF document must be uniquely determined by the tools or platformscontent of the other contributors. John is negotiatingdocument, without out-of-band data.

4.16 XML syntax

RIF must have an electronic business contract regarding the supply of variousXML syntax as its primary normative syntax.

4.17 XML types

RIF must support an appropriate set of items that Jane's company is manufacturing. Jane and John interchange the contract-related datascalar datatypes and rules involvedassociated operations as defined in XML Schema part 2 and associated specifications. See the negotiation in electronic form so that they can run simulations. Both agreecharter on a standard Business Object Model / data model (i.e., vocabulary / ontology) forDatatype support.

4.18 Merge Rule Sets

RIF must support the goods and services involved - in this case an XML schema and appropriate test XML documents are interchanged with their rules. Since John and Jane run applications based on different vendors'ability to merge rule engines andsets.

4.19 Identify Rule languages, they interchange the rules using RIF; both vendors used can interpretSets

RIF must support the identification of rule sets.

4.20 XML schema and data, and produce the results as an amendeddata

RIF should be able to accept XML document. John's company defines its purchase orderselements as data.

4.21 Internationalized text

RIF must support internationalized text that is, text that conveys additional information in terms of an XMLa language tag.

5 Use Cases

A use case for RIF consists of a description of goods, packaging, delivery location and datea problem together with delivery and payment rules.a rule proposed by John mightdescription of a solution. Most of these solutions often can be implemented using one of the following: If an item is perishable and itexisting RIF dialects in the W3C recommendation (Core, BLD, or PRD); others require the specification of a new RIF dialect.

The set of use cases is deliveredintended to John more than 10 days afterdo the scheduled delivery date thenfollowing:

  • motivate the item will be rejected by him. Thisneed for a rule set can be adequately represented in RIF Core either using (ordered) relations as e.g. in standard Logic Programming, unordered relations using named arguments, orinterchange format in a more object-oriented encoding using frames. Ordered representation in RIF Core presentation syntax using relations: Document( Prefix(pred http://www.w3.org/2007/rif-builtin-predicate# ) Prefix(func http://www.w3.org/2007/rif-builtin-function# ) Prefix(ex http://example.org/example#) Group ( Forall ?item ?deliverydate ?scheduledate ?diffdays ( ex:reject("John" ?item) :- ex:perishable(?item) ex:delivered(?item ?deliverydate "John") ex:scheduled(?item ?scheduledate)  ?diffdays = External(func:days-from-duration( External(func:subtract-dateTimes(?deliverydate ?scheduledate)) )) External(pred:numeric-greater-than(?diffdays 10)) ) ) ) Note, the nestingbroad range of external built-in functionsapplication domains and operationsindustrial sectors;
  • provide scenarios that explain the benefits of a rule interchange format in such scenarios and motivate the assignment/bindingdesign of (intermediate) result (sets) from functionsRIF;
  • motivate the working group's set of requirements for a rule interchange format; and
  • guide users to variablesRIF's specified dialects.

The set of use cases was developed over several years. Nearly fifty use cases documenting the need for a RIF were originally submitted by equality in this example. Unordered representation inRIF Core presentation syntax using namened arguments: Document( Prefix(pred http://www.w3.org/2007/rif-builtin-predicate# ) Prefix(func http://www.w3.org/2007/rif-builtin-function# ) Prefix(ex http://example.org/example#)working group ( Forall ?item ?deliverydate ?scheduledate ?diffdays ( ex:reject(ex:ware -> ?item ex:receiver -> "John") :- ex:perishable(ex:ware -> ?item) ex:delivered(ex:ware -> ?item ex:datetime -> ?deliverydate ex:receiver -> "John") ex:scheduled(ex:datetime -> ?scheduledate ex:ware -> ?item)  ?diffdays = External(func:days-from-duration( External(func:subtract-dateTimes(?deliverydate ?scheduledate)) )) External(pred:numeric-greater-than(?diffdays 10)) ) ) ) Note,members. These were grouped into general categories and then synthesized as much as possible. The arbitrarily unordered named argument argumentsgoal was to come up with a relatively small set of the user-defined relations, in contrastuse cases that would refer to external built-in functionspopular application domains and operations, which must haveindustrial sectors, and that would cover a predefined order. Object-Oriented Representation in RIF Corebroad range of possible requirements. Following the presentation syntax using frames: Document( Prefix(pred http://www.w3.org/2007/rif-builtin-predicate# ) Prefix(func http://www.w3.org/2007/rif-builtin-function# ) Prefix(ex http://example.org/example#) Group ( Forall ?item ?deliverydate ?scheduledate ?diffdays (  ?item[ex:status -> "rejected"] :-  ?item[ex:perishable -> true]  ?item[ex:deliveredOn -> ?deliverydate ex:delivered -> "John"]  ?item[ex:scheduledOn -> ?scheduledate ex:delivered -> "John"] External(pred:numeric-greater-than( External(func:days-from-duration( External(func:subtract-dateTimes(?deliverydate ?scheduledate)) )) 10 ) ) ) ) Jane replies with some suggested rule changes: If an item is perishable and it is delivered to John more than 7 days after the scheduled delivery date but less than 14 days after the scheduled delivery date then a discountof 18.7% willeach use case, we briefly discuss whether it can be applied tocovered by the delivered item. Representation inexisting three RIF Core presentation syntax using positional relations: Document( Prefix(pred http://www.w3.org/2007/rif-builtin-predicate# ) Prefix(func http://www.w3.org/2007/rif-builtin-function# ) Prefix(ex http://example.org/example#) Group ( Forall ?item ?deliverydate ?scheduledate ?diffdays ( ex:discount("John" ?item 18.7 ) :- ex:perishable(?item) ex:delivered(?item ?deliverydate "John") ex:scheduled(?item ?scheduledate)  ?diffdays = External(func:days-from-duration( External(func:subtract-dateTimes(?deliverydate ?scheduledate)) )) External(pred:numeric-greater-than(?diffdays 7)) External(pred:numeric-less-than(?diffdays 14)) ) ) ) The bindingdialects (Core, BLD, and PRD). All use cases except for 5.2 and 5.4 can be covered at least in part by at least one of the intermeditate results todialects. The variable "?diffdays" avoids repetition, as it used twicereader will note that several cases which require negation are covered only by PRD; negation is not expressible in the subsequenteither BLD or Core.


5.1 Negotiating eBusiness Contracts Across Rule conditions. As demonstrated in the previous examples, similar representations forPlatforms

This rule can be given using slots or frames and asuse case illustrates a production rule which asserts the conclusion asfundamental use of RIF: to supply a new fact. John considersvendor-neutral representation of rules. This enables rule-system developers and agrees with Jane. Both organizations utilize these rules instakeholders to do their operational systems using disparate rule representations internallywork: for example, to compute pricesmake product investments without concern for this order and determine contract compliance. Future requests for the supply of items by John's company are defined on their purchasing web site, as the appropriate XML schemavendor lock-in, and without concern that a business partner does not have the same vendor technology. It also illustrates the fact that RIF ruleset (or rulesets). This allows Jane's companycan be used to foster collaborative work. Each developer and its competitorsstakeholder can make a contribution to respond electronically with XML cost sheets. Suppliers respond with multiple cost sheets with different variations onthe RIF rules proposed by John's company, allowing John's companyjoint effort without being forced to reviewadopt the alternative rules with their associated costs to determine whether they, as a business, would benefit by relaxingtools or adding new rules as proposed by suppliers. 4.2 Negotiating eCommerce Transactions Through Disclosureplatforms of Buyer and Seller Policies and Preferences This use case concernsthe ability of parties involved in formal transactions or procedures, e.g., credit card authorizationother contributors.

John is negotiating an electronic business contract regarding the supply of a purchase, accessvarious types of private medical records, etc., to express and protect their interests within a policy-governed framework. The goalitems that Jane's company is to formally encodemanufacturing. Jane and John interchange the preferences, priorities, responses, etc., ofcontract-related data and rules involved in the partiesnegotiation in such a wayelectronic form so that the overall policythey can work as intended while providing opportunityrun simulations. Both agree on a standard Business Object Model / data model (i.e., vocabulary / ontology) for automatic negotiation of terms when allowed bythe policy. Utilization of RIFgoods and services involved. In this usecase would extend the scope of this technology, affording a higher degree of interoperability, as well as enabling re-use and sharing of preferences, etc., through interchange. The detailed scenario below shows how this would work. Alice wants to buy a device atan online site called "eShop." Alice employs software called "Emptor" that functions as automated negotiating agent for buyers. eShop employs software called "Venditor" as automated negotiating agent for sellers. Alice's and eShop's policies describe who they trust and for what purposes. The negotiation is based on the policies, which are specified as rules, and credentials Emptor and Venditor have. These policiesXML schema and credentialsappropriate test XML documents are disclosed (interchanged) so as to automatically establish trustinterchanged with the goal of successfully completing the transaction. Policies are themselves subject to access control. Thus, rule interchange is necessarily done during negotiation and (in general) depends on the current level of trust that the systems have on each other.their rules. Since EmptorJohn and Venditor might useJane run applications based on different vendors' rule languages and/orengines for evaluating (ownand imported) rules, a (standard) rule interchange format (RIF) needs to be employed for enabling therule languages, they interchange betweenthe two systems. When Alice clicks on a "buy it" button atrules using RIF; both vendors used can interpret the eShop's Web site, Emptor takes overXML schema and sends a request to eShop's site. Venditor receives the requestdata, and sends parts of its policy (i.e. a set of rules) back to Emptor. Among other things,produce the policy states that:results as an amended XML document. John's company defines its purchase orders in order to grant access a buyer must provide valid credit card information togetherterms of an XML description of goods, packaging, delivery location, and date with delivery information (address, postal code, city,and country).payment rules. A rule proposed by John might be the following:

If an item is perishable and is delivered to John more than 10 days after the scheduled delivery date, then he will reject the item.

Jane replies with some suggested rule changes:

If an item is perishable and it  belongsis delivered to John more than 7 days after the  Better Business Bureau, Alice's most trusted source of information on online shops. eShop has such a credential and its policy containsscheduled delivery date but less than 14 days after the scheduled delivery date then a  rule stating to release itdiscount of 18.7% will be applied to  any potential purchaser. Hence, Venditor passesthe  credential to Emptor. Emptor is now ready to disclose Alice's credit card informationdelivered item.

John considers this and agrees with Jane. Both organizations utilize these rules expressing Alice's and/or eShop's policies could be expressedin different rule languages but still work with the software,their operational systems using RIF-based interchanges. Secondly, assuming Venditor and Emptor are products of different companies using different internaldisparate rule languages, it would still be possible for them to work together in real-time. When these two systems needrepresentations internally to exchange policy or preference informationcompute prices for this order and determine contract compliance.

Future requests for the supply of items by John's company are defined on their respective clients they would use RIF to enablepurchasing web site, as the interchange in real-time. When Venditor sends its initial policy information to Emptor it uses RIF. Emptor takes that policyappropriate XML schema and translates it froma RIF to its internal representation in order to determine what it needs to do. 4.3 Collaborative Policy Development for Dynamic Spectrum Accessrule set (or rule sets). This use case demonstrates how RIF leadsallows Jane's company and its competitors to increased flexibility in matching the goals of end-users of a service/device,respond electronically with XML cost sheets. Suppliers respond with multiple cost sheets with different variations on the goals of providers and regulators of such services/devices.RIF can do that because it enables deployment of third party systems that can generate various suitable interpretations and/or translations ofrules proposed by John's company, allowing John's company to review the sanctionedalternative rules governingwith their associated costs to determine whether they, as a service/device.business, would benefit by relaxing or adding new rules as proposed by suppliers.


Supported by: RIF-Core, RIF-BLD, RIF-PRD

The rules of this use case concerns Dynamic Spectrum Access for wireless communication devices . Recent technological and regulatory trends are converging toward a more flexible architecturecan be adequately represented in which reconfigurable devices may operate legallyRIF-Core (and likewise, in various regulatoryRIF-BLD and service environments.RIF-PRD) by using (ordered) relations, as e.g. in standard Logic Programming, or by using unordered relations and named arguments, or in a more object-oriented encoding using frames.


5.2 Negotiating eCommerce Transactions Through Disclosure of Buyer and Seller Policies and Preferences

This use case concerns the ability of parties involved in formal transactions or procedures, e.g., credit card authorization of a devicepurchase or access of private medical records, to absorbexpress and protect their interests within a policy-governed framework. The rules defininggoal is to formally encode the policiespreferences, priorities, and responses of a region, orthe operational protocols required to dynamically access available spectrum, is contingent upon those rules beingparties in such a formway that the deviceoverall policy can use,work as wellintended while still providing opportunity for automatic negotiation of terms as their being tailored to work with devices inlong as it is allowed by the same class having different capabilities.policy. Utilizing RIF in this use-case we suppose a region adopts a policy that allows certain wireless devices to opportunisticallyuse frequency bands that are normally reserved for certain high-priority users. ( The decision bycase would extend the European Union to allow "Dynamic Frequency Selection" (DFS) usescope of the 5 GHz frequency band by wireless systems,this technology, affording a band intermittently used by militaryhigher degree of interoperability, as well as enabling re-use and weather radar, is a recent example.) Supposesharing of preferences through interchange. The policy states:detailed scenario below shows how this would work.

Alice wants to buy a wirelessdevice can transmit on a 5 GHz band if no priority user is currently using that band. Note, since default negation (not) suchat an online site called "eShop." Alice employs software called "Emptor" that functions as negationautomated negotiating agent for buyers. eShop employs software called "Venditor" as failure is not supported by RIF BLD there is no adequate way to represent that "no priority user is currently usingautomated negotiating agent for sellers.

Alice's and eShop's policies describe whom they trust and for what purposes. The band". How does a device know that no priority usernegotiation is currently using a band it wants to use? The answer will dependbased both on their policies, which are specified as rules, and on Emptor's and Venditor's credentials. These policies and credentials are disclosed (interchanged) in order to automatically establish trust with the specific capabilities of the device. One typegoal of device may answer this question by sensingsuccessfully completing the amount of energy ittransaction.

Policies are themselves subject to access control. Thus, rule interchange is receivingnecessarily done during negotiation and in general depends on that band. That is, itthe current level of mutual trust. Since Emptor and Venditor might employuse different rule languages and/or engines for evaluating their own as well as imported rules, a standard rule interchange format needs to be employed for enabling the rule: If no energy is detectedrule interchange between the two systems.

When Alice clicks on a desired band then assume no"buy it" button at eShop's Web site, Emptor takes over and sends a request to eShop's site. Venditor receives the request and sends parts of its policy (i.e. a set of rules) back to Emptor. Among other device is usingthings, the band.policy states that:

In order to grant access a buyer must provide valid credit card information together with delivery information (address, postal code, city, and country).

Rules compactly express possible ways in which a priority user is detected then assume the bandresource can be accessed; by exchanging them negotiations are shorter and privacy protection is available. Representationimproved. In RIF BLD Presentation Syntax using relations: Document( Prefix(pred http://www.w3.org/2007/rif-builtin-predicate# ) Prefix(func http://www.w3.org/2007/rif-builtin-function# ) Prefix(ex http://example.org/example#) Group ( Forall ?device ?band ?user ( ex:used(?device ?band) :- ex:detect(ex:signal(?user ?band)) ex:priority(?user,"high"). ) ) ) So each typethis example, Venditor reveals part of device will need to employ different "interpretations" or "operational definitions" of the policy in question. Now assume that there are 10 manufacturers of these 2 different types of wireless devices. Suppose that each of these manufacturers uses a distinct rule-based platform in designingits devices. Each manufacturer needs to write 2 interpretations of thepolicy (for each ofin the two types of device). That means that 20 different versionsform of the policy must be written, testedrules to enable Emptor to choose how to answer, i.e., to decide which credentials and maintained. Enter RIF. The 10 manufacturers form a consortium. This is a third-party group that is responsible for translating regional policies into RIF. When it does so, however, it provides different versions correspondingrequired information to the possible interpretations (operational definitions) of the policy. So in this case, 2 RIF versions of the DFS policy are provideddisclose.

To determine whether Venditor's request for the 2 types of device mentioned above. Each of these RIF specifications can be automatically translatedinformation is consistent with Alice's policy, Emptor takes its own rules into the appropriate rule-platform provided a RIF-Compiler for the target device architecture exists. Clearly it will be in the interestaccount. One of each device manufacturer to develop such compilers. That is because the manufacturerthese rules states:

Disclose Alice's credit card information only  needsto  develop such a compiler once for every architecture it owns. Contrast that investment with havingonline shops belonging to  produce, test, and maintain different versions of various policies over the lifetime of a product. This arrangement also allowsthe  overall process to be organizedBetter Business Bureau.

By disclosing (interchanging) the above rule, Emptor asks Venditor to provide credentials saying that it belongs to the Better Business Bureau, Alice's most trusted source of information on online shops. eShop has these credentials. Moreover, its policy contains a rule authorizing release of this credential to any potential purchaser. Hence, Venditor passes the credential to Emptor. However, before Emptor can disclose Alice's credit card information to Venditor, it must still check whether disclosing all requested information breaks Alice's denial constraints. Alice has stated the following constraint:

For purposes of anonymity, never provide both the person's birth date and postal code.

Since for this purchase, Alice birth date is not necessary, Alice's constraints are respected. Emptor therefore provides Alice's credit card information to Venditor.

Companies that provide software such as Venditor and Emptor can make use of RIF in several ways. First, the rules expressing Alice's and/or eShop's policies could be expressed in different rule languages but still work with a common software, using RIF-based interchanges. Second, RIF would enable Venditor and Emptor to work together in real time, even if these automated agents are products of different companies using different internal rule languages. When these two systems would need to exchange policy or preference information of their respective clients, they would use RIF to enable the interchange in real time. When Venditor sends its initial policy information to Emptor, it would use RIF; likewise, Emptor would take that policy and translate it from RIF to its internal representation in order to determine what it needs to do.


Not currently supported by existing RIF dialects (Core, BLD, PRD)

Current RIF dialects do not specify explicit constructs for integrity constraints; thus, this use case is not adequately supported by any of these dialects.

5.3 Collaborative Policy Development for Dynamic Spectrum Access

This use case demonstrates how RIF leads to increased flexibility in matching the goals of end-users of a service/device, with the goals of providers and regulators of such services/devices. RIF can do that because it enables deployment of third party systems that can generate various suitable interpretations and/or translations of the sanctioned rules governing a service/device.

This use case concerns Dynamic Spectrum Access for wireless communication devices. Recent technological and regulatory trends are converging toward a more flexible architecture in which reconfigurable devices may operate legally in various regulatory and service environments. The ability of a device to absorb the rules defining the policies of a region, or the operational protocols required to dynamically access available spectrum, is contingent upon those rules being in a form that the device can use, as well as their being tailored to work with devices in the same class having different capabilities.

In this use-case we suppose a region adopts a policy that allows certain wireless devices to opportunistically use frequency bands that are normally reserved for certain high-priority users. The decision by the European Union to allow "Dynamic Frequency Selection" (DFS) use of the 5 GHz frequency band by wireless systems, a band intermittently used by military and weather radar, is a recent example.)

Suppose the policy states:

A wireless device can transmit on a 5 GHz band if no priority user is currently using that band.

How does a device know that no priority user is currently using a band it wants to use? The answer will depend on the specific capabilities of the device. One type of device may answer this question by sensing the amount of energy it is receiving on that band. That is, it might employ the rule:

If no energy is detected on a desired band then assume no other device is using the band.

A second type of device may get information from a control channel that lets it know whether the desired band is being used by a priority user. That is, it might employ the rule:

If no control signal indicating use of a desired band by a priority user is detected then assume the band is available.

So each type of device will need to employ different "interpretations" or "operational definitions" of the policy in question.

Now assume that there are 10 manufacturers of these 2 different types of wireless devices. Suppose that each of these manufacturers uses a distinct rule-based platform in designing its devices. Each manufacturer needs to write 2 interpretations of the policy (for each of the two types of device). That means that 20 different versions of the policy must be written, tested, and maintained.

Enter RIF. The 10 manufacturers form a consortium. This is a third-party group that is responsible for translating regional policies into RIF. When it does so, however, it provides different versions corresponding to the possible interpretations (operational definitions) of the policy. So in this case, 2 RIF versions of the DFS policy are provided for the 2 types of device mentioned above. Each of these RIF specifications can be automatically translated into the appropriate rule-platform provided that a RIF-Compiler for the target device architecture exists. Clearly it will be in the interest of each device manufacturer to develop such compilers. That is because the manufacturer only needs to develop such a compiler once for every architecture it owns. Contrast that investment with having to produce, test, and maintain different versions of various policies over the lifetime of a product.

This arrangement also allows the overall process to be organized in a fashion that maintains the natural division of labor in the corresponding division of artifacts produced by that labor:labor. The policy and its various interpretations are written and maintained in platform-independent artifacts (RIF); knowledge about how to translate from RIF to a particular device architecture is maintained in the compilers. A change in policy is inserted at the top level in the policy artifact hierarchy where it should be; possible operational interpretations of that change are inserted at the next level down; and the implementation implications for the various device architectures is generated automatically at the lowest level.


4.4Partly supported by: RIF-PRD

The energy detection function specified in this use case would require an external call to a device that would sense the level of energy. Such procedural attachments cannot be specified in the current RIF dialects. Reaction rules support (complex) event detection capabilities on, e.g., event streams over sensor data.


This use case is not supported at all by RIF-BLD, and by extension, by RIF-Core. These dialects do not support negation, and the use case makes explicit mention of negation, e.g. for representing that "no priority user is currently using the band."

5.4 Access to Business Rules of Supply Chain Partners

A business process (BP) designer designs processes that can span multiple departments in the same business as well as other business partners. A classic example of this is the integration of supply chain business processes which typically involve multiple partners. Supply chain integration involves exposing a certain amount of business logic between partners as well as integrating processes across partners. In such activities it is therefore often necessary to access or invoke rules that originate in other ownership domains.

A key part of a business process is the logic used to make decisions within the process. Such logic is often coded in rules because rule languages are easier for BP designers to understand and manipulate than procedural code (as in Java) -- although both forms of business logic are prevalent. WhereWhen business logic is represented in different rule languages thislanguages, designing an integrated process presents a significant burden to the BP designer in designing an integrated process.designer.

Two primary integration modalities are possible: importing the different rulesetsrule sets into a single engine and processing them in a uniform manner, or accessing the rulesetsrule sets by querying remote engines and processing the results. Each modality has its uses and contra-indications. Merging rule sets of partners may not be permitted in cases where there are strong ownership boundaries involved it may not be permitted to merge rule sets of partners.boundaries.

For example, in an insurance adjustment process, the inspection of a damaged vehicle is often performed by independent inspectors. The critical decisionfactor in determining how an insurance claim will proceed is whether the damage results in a total loss or whether a repair is feasible:

If an inspector believes a vehicle is repairable then process the claim as  repaira repair; otherwise process the claim  as a total loss.

Note, belief/uncertainty cannot be specified in BLD and PRD: only true or false Belief/uncertainty cannot be specified in PRD The question ofDetermining whether a vehicle is repairable is one that is dependentdepends on the processes executed by the inspector and therefore cannot be directly integrated into the insurance companiescompany's own adjustment process. The insurance company effectively queries the inspector's logic.logic rather than incorporating the inspector's logic into its rule set. Moreover, within the adjustment process, the overall flow will be quite different for repairable claims and total loss claims.

Even in the case of a single company, which is nominally under a common ownership domain, information and business logic isare often controlled by multiple stakeholders. For example, a large company will often be organized into semi-independent profit centers (business(often known as business units). Each unit will be motivated differently, will have different ontologies and business logiclogic, and may use different rule languages to represent their logic (thislogic. This is particularly the case wherewhen one company acquires another company).company.

RIF shouldcould be used to permit the BP designer a unified view of the different partners' business rules in designing the process, while at the same time permitting the partners to continue to leverage their own business rules without changingand their own technologies.

How such aRealizing this sort of unified view of thebusiness rules can be realizedin a deployed BP will depend on both technical and non-technical factors. Even wherewhen all theparties are required to use a common rule language, there may be compelling ownership issues that mitigate against a simple merge of therule sets. In the situation whereWhen merging of rulesetsrule sets is not possible, thena query-style access to partners' business rules may be used. In this way, RIF permits a unified dynamic view of the business rule logic no matter what the original form of the rules. For this to be viable from a business perspective it is critical that the semantics of the rules and query exchange be completely predictable and preferably loss-less. 4.5 Managing Inter-Organizational Business Policies and Practices This use case concerns organizations that acquire rule sets from external sources and that have to integrate these new rule sets into their existing rule bases. Such rule sets may be acquired in the following ways: An organization may buy rule sets from expert sources An organization may use rule sets from shared interest groups such as trade associations A component of a distributed organization may acquire rules when a rule set is distributed across a distributed organization. In such case, there may be different localization requirements in different regions and locations, entailing a variety of integration challenges in these various locations and component organizations. The following scenario examines these different methods of acquisition and the various types of integration and management issues that may arise.In this scenario usesway, RIF permits a unified dynamic view of the (fictitious) car rental company, EU-Rent, used asbusiness rule logic independent of the case study inrules' original form.

For this to be viable from a business perspective the semantics of Business Vocabulary and Business Rules Specification . The EU legislation discussed is also fictitious, as arethe consulting companies CarWiserules and AutoLaw. EU-Rent's corporate HQ deals with CarWise,query exchange must be completely predictable and should be loss-less.


Not supported, in a consulting company with expertisestraightforward manner, by the current RIF dialects

The example business rule in managing fleets of vehicles. One service CarWise offersthis use case makes explicit reference to its clientsbelief, which as the discussion below indicates, is negotiating with EU regulatorsnot supported by either BLD or PRD (and thus by implication not supported by Core). The reader may note that this business rule could be changed to clarify regulations.use another term such as "determine": e.g.,

If an  EU regulator issuesinspector determines that a  directive dealing with insurance for vehicles owned by corporations. CarWise agrees withvehicle is repairable then process the  regulator on an acceptable interpretation, and provides EU-Rent (and its other car rental clients) with two sets of rules:claim as a  business policy, statingrepair; otherwise process the claim  as a total loss.

Using another term that every car rental must be insured for damages to third parties.has a supporting rule set, addressing levels of required coverage, tax calculationsimilar semantics --- i.e., indicating in different EU countries, liabilitiessome way the inspector's thought process and mental state --- does not alleviate the problem.

BLD and PRD do not support modal operators or predicates on quoted sentences; therefore standard representations of knowledge, belief, and/or uncertainty cannot be specified in rentals that span multiple countries,BLD and reporting of compliance with this business policy. EU-Rent decides that it will maintain its compliance documentation electronically. CarWise then provides EU-Rent with an additional rule set for electronic compliance documentation, includingPRD. Even without such rules as: Each tax schedule must have electronic signatures from two EU-Rent employees who are at least at the level of manager. Beforeconstructs, it can use the two general rule sets, EU-Rent needs to connect thembe possible to represent knowledge or belief using the relevant data sets in its IT systems, e.g. relate the EU country-specific taxation rules tosemantics of possible worlds [Moore1980]. That is, one can get the relevant record typeseffect of saying that an agent A believes proposition P by saying that P holds in its databases. EU-Rent corporate HQ subsequently decidesall worlds that are belief-accessible to P. For example, to get the costeffect of third-party insurance will be built intosaying

Believe(john,overCreditLimit(bill,t))

one says instead

holds(overCreditLimit(bill),t1) :- beliefAccessible(john,t,t1)

The basic cost of each rental, and not showntranslation between sentences involve operators such as a separate itemKnow and Believe and sentences that make direct use of possible worlds relies on the rental contract, to ensure that it can never be omitted from rentalspossible-worlds semantics, which posits properties on the knowledge-accessibility or disputed by renters. It then sends three rule setsbelief-accessibility relation. These relations correspond to its operating companiesaxioms on the Know and Believe operators.


Such a strategy could work, to a certain extent, in RIF-PRD, but would not work in RIF-BLD. This is because expressing the EU:standard axioms on belief or knowledge would require the rule setuse of negation, which is not supported by BLD.

For car rental insurance (from CarWise), including the basic policyboth PRD and BLD there is an additional consideration, which is that the supporting rule set.notion of reification is in general not supported by the dialects of RIF.

</p>

5.5 Managing Inter-Organizational Business Policies and Practices

This use case concerns organizations that acquire rule set for electronic compliance documentation (alsosets from CarWise). Its own rule set for building insurance into the basic rental cost. The operating companies thenexternal sources and have to localize theintegrate these new rule sets forinto their countries of operation. For example,existing rule bases. Such rule sets may be acquired in the UK, another consulting company, AutoLaw, advises EU-Rentfollowing ways:

  • An organization may buy rule sets from expert sources
  • An organization may use rule sets from shared interest groups such as trade associations
  • A component of a distributed organization may acquire rules for placing aggregate insurance for large fleets with more than one insurerwhen a rule set is distributed across a distributed organization. In order to spread the risk, for example: For fleets of more than 200 vehicles, fleet insurance policies mustsuch case, there may be placed with at least 3 insurers, eachdifferent localization requirements in different regions and locations, entailing a variety of whom covers at least 25%integration challenges in these various locations and component organizations.

The following scenario examines these different methods of acquisition and the risk. A timing issue makes it difficult for EU-Rent UK to strictly comply withvarious types of integration and management issues that may arise.

This directive. EU-Rent UK has some existing insurance policiesscenario uses the (fictitious) car rental company, EU-Rent, used as the case study in place, which provide third-party insurancethe Semantics of Business Vocabulary and Business Rules Specification. The EU legislation discussed is also fictitious, as an explicit item,are the consulting companies CarWise and it cannot get refunds on early termination. It therefore asksAutoLaw.

EU-Rent's corporate HQ fordeals with CarWise, a temporary dispensation: that it can continueconsulting company with expertise in managing fleets of vehicles. One service CarWise offers to its existing insurance until it expires, and then switchclients is negotiating with EU regulators to the new rules. EU-Rent HQ permits this, not justclarify regulations.

An EU regulator issues a directive dealing with insurance for vehicles owned by corporations. CarWise agrees with the UK, but for any ofregulator on an acceptable interpretation, and provides EU-Rent (and its operating companies that have similar insurance arrangements. To ensure that this dispensation is temporary, it addsother car rental clients) with two sets of rules:

  • A new rule: Insurance policiesbusiness policy, stating that provide separate third-party coverageevery car rental must notbe renewed. EU-Rent HQ is also concerned about meeting deadlinesinsured for electronic filing. It introducesdamages to third parties.
  • A newsupporting rule set, addressing levels of required coverage, tax calculation in different EU countries, liabilities in rentals that it distributes to operating companies: Each electronicspan multiple countries, and reporting of compliance document must have its required electronic signatures 48 hours before its filing deadline.with this business policy.

EU-Rent decides that it will maintain its compliance documentation electronically. CarWise then provides EU-Rent with an additional rule is meant to be implemented as follows: If '48 hours before filing deadline' passes, and theset for electronic compliance documentation, including such rules as:

Each tax schedule must have electronic signatures from two EU-Rent employees who are  not present, then the operating company's rules system must reportat least at the  out-of-compliance situation, and subsequently wait forlevel of manager.

Before it can use the responsible managerstwo general rule sets, EU-Rent needs to connect them to providethe signatures. 4.6 Ruleset Integration for Medical Decision Support Decision support systems aidrelevant data sets in its IT systems, e.g. relate the process of human decision making, especially decision making that relies on expertise. Reasoning withEU country-specific taxation rules is an important part of this expert decision making. For complex decision support systems, it is expectedto the relevant record types in its databases.

EU-Rent corporate HQ subsequently decides that rulesthe cost of third-party insurance will be furnished by a varietybuilt into the basic cost of different sources, including ontologies, knowledge bases,each rental and other expert systems.not shown as a separate item on the rental contract; this use case illustrates how RIF makeswill ensure that it possible to merge rulesetscan never be omitted from diverse sourcesrentals or disputed by renters. It then sends three rule sets to its operating companies in diverse formats into one rule-based system, thereby enabling inferences that might otherwise have remained implicit. Medical decision support systems, such asthe ones discussed below, might use rules from pharmaceutical knowledge bases, laboratory knowledge bases, patient databases,EU:

  • The rule set for car rental insurance (from CarWise), including the basic policy and medical ontologies.the supporting rule set.
  • The rule set for electronic compliance documentation (also from CarWise).
  • Its own rule set for building insurance into the basic rental cost.

The operating companies then have to localize the rule sets for example, a large amounttheir countries of information on therapeutic medications (drug taxonomies, indications, contraindications, and clearance times) and diseases (disease taxonomies, etiologies, and symptoms) is containedoperation. For example, in existing ontologies such as SNOMED Clinical Terms®.the UK, another consulting company, AutoLaw, advises EU-Rent of rules can be used to express therapeutic recommendations, to formulate queries about relevant prescriptionsfor a patient, andplacing aggregate insurance for large fleets with more than one insurer in order to assessspread the effectivenessrisk:

For fleets of  a treatment. The following scenario illustrates how rule-interchange wouldmore than 200 vehicles, fleet insurance policies must be  used in various medical decision support systems to supportplaced with at least 3 insurers, each of whom covers at least 25% of the  following functionalities: Improving situation assessment, e.g., determining whenrisk.

A patient needstiming issue makes it difficult for EU-Rent UK to be put on medication, or have his medication switched. Prescribing a course of action, e.g., determiningstrictly comply with this directive. EU-Rent UK has some existing insurance policies in place, which drug is bestprovide third-party insurance as an explicit item, and it cannot get refunds on early termination. It therefore asks corporate HQ for a patient in a particular circumstance. Improving event planning, e.g., determining whethertemporary dispensation: that it can continue its existing insurance until it expires, and then switch to the new rules.

EU-Rent HQ permits this, not just for the UK but for any of its operating companies that have similar insurance arrangements. To ensure that this dispensation is temporary, it adds a patient cannew rule:

Insurance policies that provide separate third-party coverage must not be  scheduledrenewed.

EU-Rent HQ is also concerned about meeting deadlines for electronic filing. It introduces a procedure given the medicationnew rule that heit distributes to operating companies:

Each electronic compliance document must have its required electronic signatures 48 hours before its filing deadline.

This rule is currently taking. Bob, 62 years old and reasonably healthy, has been goingmeant to his internist, Dr. Rosen, for several years for control of his Type II diabetes. Dr. Rosen has been usingbe implemented as follows: If '48 hours before its filing deadline' passes, and the AutoDocelectronic signatures are not present, then the operating company's rules system to help him decide when to switch to medicationsmust report the out-of-compliance situation, and which drugssubsequently wait for the responsible managers to prescribe.provide the AutoDoc system uses two sources when making its recommendations: a laboratory knowledge base giving particular resultssignatures.


Partially supported by RIF-PRD

The business rules in this use case express norms which requires the representation of deontic operators for patientsobligations and specifying when these resultspermissions. Deontic operators are out of normal range,generally represented by modal operators, as in [Horty2001]. As was discussed above for knowledge and belief, it is not possible to express modal operators directly within RIF dialects. However, one can use the technique discussed above, of reasoning directly within possible worlds. This is possible within PRD though not within BLD or Core.

Moreover, in a pharmaceutical knowledge base giving guidelinesmeta programming approach it is possible to express deontic reasoning rules with RIF-PRD. Using this approach, too, one would not be able to use BLD or Core, since some business rules express negated deontic norms.

5.6 Rule set Integration for Medical Decision Support

Decision support systems aid in the useprocess of medications. Automatedhuman decision making, especially decision making that relies on expertise. Reasoning with rules from these combined sourcesis possible if the rules are first mapped to RIF. Here are two specific examplesan important part of such synergistic effects.this scenario discusses the fictitiousexpert systems AutoDoc and MEDIC. In the interest of readability and brevity, the information anddecision making. For complex decision support systems, it is expected that rules presented in the following scenario may not precisely capture the current state of medical knowledge and best practices in this field, but maywill be somewhat simplified. Originally Bob's diabetes was controlled through diet and moderate exercise. In time, however, Bob's blood glucose level began to rise, even under this regimen. Due to Bob's elevated HbA1c level (which indicates one's average blood sugar level over the last several months), Dr. Rosen prescribed oral medication for Bob. He was forced to change Bob's medicationfurnished by a number of times over the coursevariety of a year. He first prescribed Precose, an oral alpha-glucosidase inhibitor, but had to discontinue this medication due to undesired side effects. He then prescribed several sulfonylurea drugs, Micronasedifferent sources, including ontologies, knowledge bases, and Glucotrol,other expert systems. This use case illustrates how RIF makes it possible to no avail. Bob's lab results still indicated an elevated HbA1c level.merge rule sets from diverse sources in diverse formats into one rule-based system, thereby enabling inferences that might otherwise have remained implicit.

Medical decision support systems, such as the following ruleones discussed below, might use rules from thepharmaceutical knowledge bases, laboratory knowledge base suggests that Bob's treatment at that time was not effective: Ifbases, patient databases, and medical ontologies. For example, a Type II diabetes patient's current levellarge amount of HbA1c is high, then the patient's current treatmentinformation on therapeutic medications (drug taxonomies, indications, contraindications, and clearance times) and diseases (disease taxonomies, etiologies, and symptoms) is considered to be ineffective. Representationcontained in RIF BLD Presentation Syntax using relations and an event calculus axiomatization: Document( Prefix(pred http://www.w3.org/2007/rif-builtin-predicate# ) Prefix(func http://www.w3.org/2007/rif-builtin-function# ) Prefix(ex http://example.org/example#) Group ( Forall ?Patient ?Treatment ?Level ?T ( ex:holdsAt(ex:ineffective(?Patient ?Treatment) ?T) :- ex:holdsAt(ex:hasDisease(?Patient "diabetesTypeII") ?T) ex:holdsAt(ex:elevated(levelOf(?Patient "hbA1c" ?Level)) ?T) ex:holdsAt(ex:treatmentPlan(?Treatment ?Patient) ?T) ) ) ) Note, the example requires the formalization of changeable states which can be represented by an event calculus axiomatization. KS86 ] The EC axiomsexisting ontologies such as SNOMED Clinical Terms®. Rules can thenbe represented using RIF BLD.used to deal with this problem, Dr. Rosen wasexpress therapeutic recommendations, to formulate queries about relevant prescriptions for a patient, and to prescribe Glucophage (metformin, one ofassess the biguanides) 850 mg, 3 timeseffectiveness of a day, when as usual, he double checked his prescription with the AutoDoc system. The system, based ontreatment.

The following guidelines from the pharmaceutical knowledge base , informed Dr. Rosen that he should have prescribed an oral bitherapy (two medications, each of which controls blood sugar levels) instead of a monotherapy. If an oral monotherapy at recommended doses of a sulfonylurea or biguanide, combined with lifestyle changes, is ineffective, thenscenario illustrates how rule-interchange would be used in various medical decision support systems to support the monotherapy shouldfollowing functionalities:

  • Improving situation assessment, e.g., determining when a patient needs to be replaced by an oral bitherapy. Basedput on the recommendation from AutoDoc , Dr. Rosen switched Bob's prescription to Glucophage and Avandia (rosiglitazone, onemedication, or have his medication switched.
  • Prescribing a course of the thiazolidinediones). Bob recently sufferedaction, e.g., determining which drug is best for a concussion and has become increasingly forgetful. He went to seepatient in a neurologist, Dr. Cervello, who prescribedparticular circumstance.
  • Improving event planning, e.g., determining whether a contrast MRI (Magnetic Resonance Imaging). When asked about current medication, Bob told Dr. Cervellopatient can be scheduled for a procedure given the medication that he was taking Glucotrolis currently taking.

Bob, 62 years old and reasonably healthy, has been going to his internist, Dr. Rosen, for several years for control of his diabetes, forgetting that he hadType II diabetes. Dr. Rosen has been switched to Glucophage. This was potentially problematic, since Glucophage should not be taken close tousing the administration of a contrast injection. Fortunately,AutoDoc system to help him decide when Bob wentto the labswitch to schedule his MRI, the medical receptionist pulled up MEDIC (Medical Eventmedications and Drug Interaction Consultant), the hospital's new automated system,which checks for incompatible medical events and/ordrugs (e.g., liposuction scheduled during pregnancy, blood thinners prescribed before surgery, etc.). MEDICto prescribe. The AutoDoc system uses a variety oftwo sources in its reasoning, including: the pharmaceutical knowledge base, described above the patient databases, which gives the patient record, including the medications a patient is currently taking the hospital medical event protocolwhen making its recommendations: a laboratory knowledge base, which details the protocol usedbase giving particular results for different medical procedures In this case, MEDIC uses all three sources,patients and pulls up the following information: Metformin is contraindicated with contrast dye. Metformin is the generic formspecifying when these results are out of Glucophage. Bob is taking Glucophage.normal range, and a pharmaceutical knowledge base giving guidelines for the contrast MRI requires as oneuse of its steps injecting the patientmedications. Automated reasoning with contrast dye. MEDIC therefore determines that Bob should not be taking the contrast MRI at this time. For MEDIC to work, therules from these differentcombined sources must beis possible if the rules are first mapped to a unified interchange format. 4.7 Interchanging Rule Extensions to OWL RulesRIF. Here are often used in conjunction with other declarative knowledge representation formalisms,two specific examples of such as ontology languages (e.g. RDFsynergistic effects.

This scenario discusses the fictitious expert systems AutoDoc and OWL),MEDIC. In order to provide greater expressive power than is provided by either formalism alone. Ontology languages, for example, typically provide a richer language for describing classes (unary predicates). Rules, onthe other hand, typically provide a richer language for describing dependencies between properties (binary predicates),interest of readability and brevity, the information and may also support higher-arity predicates. Rich domain models combining bothrules presented in the following scenario may not precisely capture the current state of medical knowledge and ontologies are often neededbest practices in domains such as medicine, biology, e-Sciencethis field, but may be somewhat simplified.

Originally Bob's diabetes was controlled through diet and Web services.moderate exercise. In such domains,time, however, Bob's blood glucose level began to rise, even under this regimen. Due to Bob's elevated HbA1c level (which indicates one's average blood sugar level over the last several actors and/or agents are involved that havemonths), Dr. Rosen prescribed oral medication for Bob. He was forced to interchangechange Bob's medication a number of times over the data, ontologies,course of a year. He first prescribed Precose, an oral alpha-glucosidase inhibitor, but had to discontinue this medication due to undesired side effects. He then prescribed several sulfonylurea drugs, Micronase and rules that they work with.Glucotrol, to no avail. Bob's lab results still indicated an example iselevated HbA1c level. The use of suchfollowing rule from the laboratory knowledge base suggests that Bob's treatment at that time was not effective:

If a  domain modelType II diabetes patient's current level of HbA1c is high, then the patient's current treatment is considered to be ineffective.

To capture knowledgedeal with this problem, Dr. Rosen was about mereological and spatial dependencies between properties. For example, a rule is usedto expressprescribe Glucophage (metformin, one of the dependency betweenbiguanides) 850 mg, 3 times a day, when as usual, he double checked his prescription with the ontology properties isMAEConnectedTo and isMAEBoundedBy, in particular (a simplified form of)AutoDoc system. The system, based on the following guidelines from the pharmaceutical knowledge base, informed Dr. Rosen that two Material Anatomical Entities havinghe should have prescribed an oral bitherapy (two medications, each of which controls blood sugar levels) instead of a shared boundary are connected:monotherapy.

If  MAE X is bounded by Z and MAE Yan oral monotherapy at recommended doses of a sulfonylurea or biguanide, combined with lifestyle changes, is  also bounded by Zineffective, then  X is connected to Y. Benefits of interchange via RIF includethe  ability to collaboratively develop and share valuable knowledge,monotherapy should be replaced by an oral bitherapy.

Based on the ability to integrate anatomical images, possiblyrecommendation from distributed image sources, and the abilityAutoDoc, Dr. Rosen switched Bob's prescription to use large-scale federated systems for statistical analysis of brain images of major brain pathologies. 4.8 Vocabulary Mapping for Data Integration This use case concerns the integrationGlucophage and Avandia (rosiglitazone, one of information from multiple data sources.the Semantic Web providesthiazolidinediones).

Bob recently suffered a common data representationconcussion and query language, which greatly simplifies accesshas become increasingly forgetful. He went to see a neurologist, Dr. Cervello, who prescribed a contrast MRI (Magnetic Resonance Imaging). When asked about current medication, Bob told Dr. Cervello that he was taking Glucotrol to diverse sources but does not directly address the problemcontrol his diabetes, forgetting that independent data sources may have rather divergent information models. Rules are an effective wayhe had been switched to express mappings between such information models. However, rules locked within local proprietary systems cannotGlucophage. This was potentially problematic, since Glucophage should not be reused. Withtaken close to the administration of a common rule representation, such mappings can be published acrosscontrast injection.

Fortunately, when Bob went to the Semantic Web, enabling an enterprise or communitylab to progressively buildschedule his MRI, the medical receptionist pulled up MEDIC (Medical Event and Drug Interaction Consultant), the hospital's new automated system, which checks for incompatible medical events and/or drugs (e.g., liposuction scheduled during pregnancy, blood thinners prescribed before surgery, etc.).

MEDIC uses a rich networkvariety of mappings unifying the information models. Information mapping and integration problems like this arisesources in many diverse domainsits reasoning, including:

  • the pharmaceutical knowledge base, described above
  • the patient databases, which gives the patient record, including health care, travel planning, IT managementthe medications a patient is currently taking
  • the hospital medical event protocol knowledge base, which details the protocol used for different medical procedures

In this case, MEDIC uses all three sources and customer information management.pulls up the following scenario comes frominformation:

  • Metformin is contraindicated with contrast dye.
  • Metformin is the worldgeneric form of IT systems management. Vlad has been givenGlucophage.
  • Bob is taking Glucophage.
  • The contrast MRI requires as one of its steps injecting the patient with contrast dye.

MEDIC therefore determines that Bob should not be taking the job of analyzing how exposed his division's business processes arecontrast MRI at this time.

For MEDIC to changes in their IT maintenance contracts. He has threework, the rules from these different sources of informationmust be mapped to combine: a report on application services and associated servers, databases and networks (from the IT department)a maintenance contracts database (fromunified interchange format.


Supported by RIF-PRD

The finance department) a registry indicating which business processesuse which IT services (fromcase requires the business planning group) Eachformalization of these sources is in a different form butchangeable states (fluents) which can be mapped into RDF to simplify access.represented by e.g. an event calculus axiomatization [KS86]. However, they all have different information models.to formulate the classical event calculus as a set of Horn clause rules so that it reportcould be run as a Prolog program, negation as failure is too fine-grained: it talks about routersneeded, which is not supported by RIF-BLD or Core. The use case can be represented in RIF-PRD which supports changeable states (modifications) and interface cards whereas Vlad only needsassertions and retractions of knowledge.

5.7 Interchanging Rule Extensions to identify serversOWL

Rules are often used in conjunction with other declarative knowledge representation formalisms, such as ontology languages (e.g. RDF and pick out some generic dependency relations.OWL), in order to provide greater expressive power than is provided by either formalism alone. Ontology languages, for example, typically provide a richer language for describing classes (unary predicates). Rules, on the other hand, the finance database models the worldtypically provide a richer language for describing dependencies between properties (binary predicates), and may also support higher-arity predicates.

Rich domain models combining both rules and ontologies are often needed in terms of physical assetsdomains such as racks, which is too coarse-grained. First, Vlad creates simple mapping rulesmedicine, biology, e-Science, and Web services. In such domains, several actors and/or agents may need to create a uniform, simplified view ofinterchange the data in terms of a small number of concepts -- Server, Business Processdata, ontologies, and Dependency. This involvesrules such as: If xthat they work with. An example is the use of such a ComputeNodedomain model in Rack r and Rack r isan application that aims at assisting the labeling of brain cortex structures in Cage c and mc is a MaintenanceContract for Cage c then xMRI images. In this case, an OWL ontology is used to capture knowledge about the most important brain cortex anatomical structures, and a Server with MaintenanceContract mc If xrule base is a ComputeNode with a NetworkInterface with Port pused to capture knowledge about mereological and app is an Application running on Port p then x isspatial dependencies between properties.

For example, a Server that hosts app If bprule is a BusinessProcess that uses Application app then bp has aused to express the dependency on app Representation in RIF BLD Presentation Syntax using relations: Forall ?X ?MC ?R ?C(  ?X[rdf:type->ex:Server ex:maintenanceContract->?MC] :- And(  ?X[rdf:type->ex:ComputeNode ex:location->?R] ?R#ex:Rack  ?R[ex:location->?C] ?C#ex:Cage  ?C[ex:maintenanceContract->?MC] ?MC#ex:MaintenanceContract )) Forall ?X ?Ni ?P ?App (  ?X[rdf:type->ex:Server ex:hosts->?App] :- And(  ?X[rdf:type->ex:ComputeNode ex:networkInterface->?Ni]  ?Ni[ex:port->?P]  ?P#ex:Port  ?App[rdf:type->ex:Application ex:onPort->?P])) Forall ?App ?BP (  ?BP[ex:dependsOn->?App] :-  ?BP[rdf:type->ex:BusinessProcess ex:processUses->?App] )) He then creates rules that combinebetween the data across his now simplified data sources, e.g. If bp is a BusinessProcessontology properties isMAEConnectedTo and isMAEBoundedBy, in particular (a simplified form of) the knowledge that hastwo Material Anatomical Entities having a Dependency on Application app andshared boundary are connected:

If MAE X is  a Server with MaintenanceContract mc that hosts Application appbounded by Z and MAE Y is also bounded by Z then  bp has a Dependency on mc Representation in RIF BLD Presentation Syntax using relations: Forall ?App ?BP ?App ?MC(  ?BP[ex:dependsOn->?MC] :- <  ?BP[rdf:type->ex:BusinessProcess ex:dependsOn->?App] ?App#ex:Application  ?X[rdf:type->ex:Server ex:hosts->?App ex:maintenanceContract->?MC] )) This gives him a uniform view that links from business processes throughX is connected to Y.

Benefits of interchange via RIF include the ITability to collaboratively develop and finance data. Vlad publishes these rules so that other people acrossshare valuable knowledge, the company can reuse themability to construct similar views. 4.9 BPEL Orchestration of Rule-Based Web Services Rule-based Web services depend on the use of XML data for their requestintegrate anatomical images, possibly from distributed image sources, and response format.the involved rules must be ableability to access and compare XML data in their conditions and modify and generate XML data in their actions. An existing commercial credit approval service deployed as a Web service takes an applicant credit request document as input and returns an approval or denial (with reason). It is implemented as a BPEL orchestrationuse large-scale federated systems for statistical analysis of two Web services -- a credit history providing servicebrain images of major brain pathologies.


Supported by RIF-Core, RIF-BLD and a decision service containing a rules engine. BPEL first passesRIF-PRD

The credit request documentuse case uses RIF-SWC to combine RIF Rules with OWL ontologies.

5.8 Vocabulary Mapping for Data Integration

This use case concerns the decision service to determine, using rules, whether enoughintegration of information (SSN, mother's maiden name, etc.) is available to request a credit history. If so, BPEL then requests a credit historyfrom multiple data sources. The history providing serviceSemantic Web provides a common data representation and passes the credit history documentquery language, which greatly simplifies access to diverse sources but does not directly address the decision serviceproblem that independent data sources may have rather divergent information models.

Rules are an effective way to express mappings between such information models. However, rules locked within local proprietary systems cannot be evaluated. Based on the evaluation, credit is approved or denied. Because the rule engine is part ofreused. With a Web service, existing BPEL diagramming and execution facilitiescommon rule representation, such mappings can be usedpublished across the Semantic Web, enabling an enterprise or community to integrate rules intoprogressively build up a rich network of mappings unifying the information models.

Information mapping and integration problems like this credit approval service.arise in many diverse domains including health care, travel planning, IT management, and customer information management. The credit evaluation model can be changed easily using GUI toolsfollowing scenario comes from the world of IT systems management.

Vlad has been given the job of analyzing how exposed his division's business processes are to customize rules.changes in their IT maintenance contracts. He has three sources of information to combine:

  • a report on application services and associated servers, databases, and networks (from the IT department)
  • a maintenance contracts database (from the finance department)
  • a registry indicating which business processes use of RIF would improve the situation further. First,which IT services (from the credit history vendor could supply a default setbusiness planning group)

Each of rules for evaluating its histories. Second, there would be several rule editing and customization tools fromthese sources is in a different RIF compatible vendorsform but can be mapped into RDF to tailorsimplify access. However, they all have different information models. The rulesIT report is too fine-grained: it talks about routers and interface cards while Vlad only needs to meet specific business objectives.identify servers and pick out some generic dependency relations. On the credit evaluation rules are themselves grouped into three rulesets that are executed sequentially. Rules inother hand, the first ruleset apply thresholds to several "red flag" quantities infinance database models the credit report, such as: numberworld in terms of timesphysical assets such as racks, which is too coarse-grained.

First, Vlad creates simple mapping rules to create a payment was 60 days late debt-to-income ratio numberuniform, simplified view of foreclosures or repossessions numberthe data in terms of garnishmentsa small number of liens bankruptcyconcepts -- Server, BusinessProcess, and Dependency. This involves rules such as:

 If x is a  red flag above the threshold resultsComputeNode in  denial of credit. RulesRack r
    and Rack r is in  the second ruleset incrementCage c
    and mc is a  credit score variable.MaintenanceContract for  example: If applicant owns residence then add 40. If applicant rents then add 30. If applicant has lived at current address 2 to 4 yearsCage c
       then  add 20.x is a Server with MaintenanceContract mc
 
 If  applicant's incomex is  under 20000a ComputeNode with a NetworkInterface with Port p
    and app is an Application running on Port p
       then  add 10.x is a Server that hosts app
 
 If  applicant's incomebp is  between 40000 and 50000a BusinessProcess that uses Application app
       then  add 40.bp has a Dependency on app

He then creates rules that combine the data across his now simplified data sources, e.g.

 If bp is a  goal-driven solution with makes use of assert and retract (not supported by BLD) to updateBusinessProcess that has a  global score value, whichDependency on Application app
   and x is  storeda Server with MaintenanceContract mc that hosts Application app
      then bp has a Dependency on mc

This gives him a fact.uniform view that links from business processes through to the thirdIT and final ruleset comparesfinance data. Vlad publishes these rules so that other people across the applicant's credit score and incomecompany can reuse them to threshold values,construct similar views.


Supported by RIF-BLD, RID-PRD, and makes the final decision to approve or deny credit to the applicant.RIF-Core

5.9 BPEL Orchestration of Rule-Based Web Services

Rule-based Web services depend on the decisionuse of XML data for their request and supporting rationale is returned fromresponse format. The decisioninvolved rules must be able to access and compare XML data in their conditions and modify and generate XML data in their actions.

An existing commercial credit approval service deployed as a Web service takes an XML document. This decision document is then used to construct the reply to the originalapplicant credit request document as input and returns an approval request. 4.10 Publishing Rules for Interlinked Metadata The Semantic Web includes technologies (e.g., RDF) that allow metadata to be published in machine-readable form. Currently, this informationor denial (with reason). It is mostly enumeratedimplemented as a set of facts. It is often desirable, however, to supplement such facts with rules that capture implicit knowledge . To maximize the usefulnessBPEL orchestration of such published rules,two Web services -- a standard rule format such as RIF is necessary. One case involves extending current standards for metadata publication with rules in order to express implicit knowledge. Suppose that the International Movie Database (IMD) publishes its metadatacredit history providing service and a decision service containing a rules in a machine readable format at http://imd.example.org. Besides the ground facts, which can be expressed in RDF, the metadata might also have general rules likeengine. BPEL first passes the following: Every science fiction moviecredit request document to the decision service to determine, using rules, whether enough information (Social Security number, mother's maiden name, etc.) is available to request a movie. Every movie produced before 1930 is blackcredit history. If so, BPEL then requests a credit history from the history providing service and white. Representation in RIF BLD (Abridged) Presentation Syntax using relations:  ?Movie#ex:Movie :-  ?Movie#ex:ScienceFictionMovie. ?Movie#ex:BlackWhiteMovie :-  ?Movie#ex:Movie[ex:date -> ?Date]  ?Date < "1930"^^xs:dateTime. Such rules allow datapasses the credit history document to the decision service to be published more concisely by expressing knowledge that, without these rules,evaluated. Based on the evaluation, credit is implicit. This can greatly simplifyapproved or denied.

Because the maintenancerule engine is part of data, guard against inadvertently introduced inconsistencies,a Web service, existing BPEL diagramming and reduce storage requirements. Published rules also allow combining data from different sourcesexecution facilities can be used to exploitintegrate rules into this knowledge. Consider an alternative database of movies published at http://altmd.example.org. In addition to metadata, it again publishes its own rules: All movies listed at http://altmd.example.org but not listed at http://imd.example.org are independent movies. All movies with budgets below 5 million USD are low-budget movies. Representation in RIF BLD (Abridged) Presentation Syntaxcredit approval service. The credit evaluation model can be changed easily using relations:  ?Movie#ex:IndependentMovie :- listed(?Movie#ex:Movie,<http://altmd.example.org>) not(listed(?Movie#ex:Movie,<http://imd.example.org>)). ?Movie#ex:LowBudgetMovie :-  ?Movie#ex:Movie [date -> ?Date, budget -> ?Budget]  ?Budget < 5000000^^xs:long. Publication of rules with explicit referencesGUI tools to other rulesets allows the definition of knowledge dependent on explicitly specified remote sources. Such explicitly specified scope is important incustomize rules. Using RIF would further improve the Web environment, since it can reducesituation. First, the dangercredit history vendor could supply a default set of unintended interference fromrules published at other remote sources, which mayfor evaluating its histories. Second, there would be exporting their own predicates. Another example of such explicit referencing, which also illustrates implicit person-centric metadata, involves publishedseveral rule editing and customization tools from different RIF-compatible vendors to tailor the rules being usedto specify howmeet specific business objectives.

The credit evaluation rules are themselves grouped into three rule sets that are executed sequentially. Rules in the first rule set apply thresholds to use other metadata, e.g.several "red flag" quantities in the formcredit report, such as:

  • number of times a widespread vocabulary such as FOAFpayment was 60 days late
  • debt-to-income ratio
  • number of foreclosures or repossessions
  • number of garnishments
  • number of liens
  • bankruptcy

A standard exchange format like iCalendar. For example, FOAF user Charlie might choose to complement his normal FOAF profile with his preferences about whichred flag above the threshold results in denial of his phone numbers should be used depending on his iCalendar schedule: If Charlie is currently attendingcredit.

Rules in the second rule set increment a public talk according to http://charlie.example.org/calender.icalcredit score variable. For example:

 If applicant owns residence then  leave him a voicemail messageadd 40.
 If  Charlie is currently in a meeting accordingapplicant rents then add 30.
 If applicant has lived at current address 2 to  http://charlie.example.org/calender.ical and the importance4 years then add 20.
 If applicant's income is  highunder 20000 then  call his cell numberadd 10.
 If  Charlie currently has no appointments according to http://charlie.example.org/calender.icalapplicant's income is between 40000 and 50000 then  call his office numberadd 40.

The Webthird and final rule set compares the applicant's credit score and income to support new kinds of "intelligent" crawlingthreshold values, and search. 5 Requirementsmakes the goalsfinal decision to approve or deny credit to the applicant.

The decision and supporting rationale is returned from the decision service as an XML document. This decision document is then used to construct the reply to the original credit approval request.


Supported by RIF-PRD

This use cases motivatecase requires a numbergoal-driven solution which makes use of requirements forassert and retract to update a Rule Interchange Format. The Working Group has currently approved the following requirements. Requirements listed as "General"global score value. Assert and retract are deemednot supported by BLD or Core; indeed, there is no such similar notion within BLD or Core.

5.10 Publishing Rules for Interlinked Metadata

The Semantic Web includes technologies (e.g., RDF) that allow metadata to be fundamental properties which needpublished in machine-readable form. Currently, this information is mostly enumerated as a set of facts. It is often desirable, however, to be fully covered bysupplement such facts with rules that capture implicit knowledge. To maximize the currently specifiedusefulness of such published rules, a standard rule format such as RIF dialects. Basic requirementsis necessary.

One case involves extending current standards for metadata publication with rules in order to express implicit knowledge. Suppose that the International Movie Database (IMD) publishes its metadata and rules in a Rule Interchangemachine readable format are motivated by specific use cases. 5.1 General 5.1.1 Implementability RIF mustat http://imd.example.org. Besides the ground facts, which can be implementable using well understood techniques, and should not require new research in e.g. algorithms or semanticsexpressed in order to implement translators. 5.1.2 Semantic precision RIF core mustRDF, the metadata might also have general rules like the following:

 Every science fiction movie is a  clear and precise syntaxmovie.
 Every movie produced before 1930 is black and  semantics. Each standardwhite.

Such rules allow data to create new RIF dialects which extend existing dialects (thus providing backward compatibility) and are handled gracefully by systems which support existing dialects (thus providing forward compatibility). 5.1.4 Translators For every standard RIF dialect it mustbe possible to implement translators between rule languages coveredpublished more concisely by that dialect and RIFexpressing knowledge that, without changingthese rules, is implicit. This can greatly simplify the rule language. 5.1.5 Standard componentsmaintenance of data, guard against inadvertently introduced inconsistencies, and reduce storage requirements.

Published rules also allow combining data from different sources to exploit this knowledge. Consider an alternative database of movies published at http://altmd.example.org. In addition to metadata, it again publishes its own rules:

 All movies listed at http://altmd.example.org but not listed at http://imd.example.org are independent movies.
 All movies with budgets below 5 million USD are low-budget movies.

Publication of rules with explicit references to use standard support technologies such as XML parsers andother parser generators, and should not require special purpose implementations when reuse is possible. 5.1.6rule language coverage Because ofsets allows the great diversitydefinition of rule languages, no one interchange languageknowledge dependent on explicitly specified remote sources. Such explicitly specified scope is likely to be able to bridge between all. Instead, RIF provides dialects which are each targeted at a cluster of similar rule languages. RIF must allow intra-dialect interoperation, i.e. interoperability between semantically similar rule languages (via interchange of RIF rules) within one dialect, and it should support inter-dialect interoperation, i.e. interoperation between dialects with maximum overlap. 5.2 Basic Requirements 5.2.1 Compliance modelimportant in the RIF specifications must provide clear conformance criteria, defining what is or is not a conformant RIF implementation. 5.2.2 Default behavior RIF must specify atWeb environment, since it can reduce the appropriate leveldanger of detail the default behavior that is expectedunintended interference from a RIF compliant application that does not have the capability to process all or partrules published at other remote sources, which may be exporting their own predicates.

Another example of thesuch explicit referencing, which also illustrates implicit person-centric metadata, involves published rules described in a RIF document, or it must provide a waybeing used to specify such default behavior. 5.2.3 Different semantics RIF must cover rule languages having different semantics. 5.2.4 Limited numberhow to use other metadata, e.g. in the form of dialects RIF must havea standard core andwidespread vocabulary such as FOAF or a limited number ofstandard dialects based upon that core. 5.2.5 Embedded comments RIF must be ableexchange format like iCalendar. For example, FOAF user Charlie might choose to pass comments. 5.2.6 Embedded metadata RIF must support metadata such as author and rule name. 5.2.7 OWL data RIF must cover OWL knowledge bases as data where compatible with RIF semantics. 5.2.8 RDF data RIF must cover RDF triples as data where compatiblecomplement his normal FOAF profile with RIF semantics. 5.2.9 Dialect Identification The semanticshis preferences about which of a RIF document musthis phone numbers should be uniquely determined by the content of the document, without out-of-band data. 5.2.10 XML syntax RIF must have an XML syntax as its primary normative syntax. 5.2.11 XML types RIF must support an appropriate set of scalar datatypes and associated operations as definedused depending on his iCalendar schedule:

 If Charlie is currently attending a public talk according to http://charlie.example.org/calender.ical
     then leave him a voicemail message
 
 If Charlie is currently in  XML Schema part 2a meeting according to http://charlie.example.org/calender.ical
   and  associated specifications. Seethe  charter on Datatype support . 5.2.12 Merge Rule Setsimportance is high
     then call his cell number
 
 If Charlie currently has no appointments according to http://charlie.example.org/calender.ical
     then call his office number


RIF should allow extending current standards for metadata publication by enabling such implicit knowledge to be ablecaptured via rules and allowing metadata and rules distributed over different sources to accept XML elements as data. 5.2.15 Internationalized textbe interlinked. In a manner similar to how HTML links human-readable Web pages, RIF mustshould permit linking metadata on the Web to support internationalized text that is, text that additionally conveys information in termsnew kinds of a language tag."intelligent" crawling and search.


Supported by RIF-PRD

Since negation is not supported by RIF-BLD or RIF-Core it is not possible to express ... but not listed at ....


6 Conclusion

The goal of the RIF working group is to provide representational interchange formats for processes based on the use of rules and rule-based systems. These formats act as "interlingua"interlingua to interchange rules and integrate with other languages, in particular (Semantic) Web mark-up languages.

As can be seen by studying the use-cases presented in this document, rules are used to perform a wide variety of tasks, and, therefore,and therefore rule-based systems are not monolithic. Rules have been usedused, for example, to perform orand validate inference, perform calculations, direct the flow of information, enforce integrity constraints on databases, represent and enforce policies, control devices and processes in real-time,real time, and determine the need for human intervention, and so on.intervention.

In light of this diversity the working group expects that RIF,diversity, rather than being a single all-encompassing format, will consistRIF consists of several dialects, each dialect serving a particular set of related rule languages. The key idea is to attain the goal of interoperability (via interchange of RIF rules) within each dialect. This should allow the main benefits of RIF to be realized. For example, the invariant meaning of a set of integrity-constraint-enforcing rules would be represented within the appropriate RIF dialect and could then be translated into the native format of any of the formalisms capablemain benefits of representing such rules.RIF mustto be realized.

RIF has been designed in such a way that it is possible to create new dialects (extensibility) according to the overall goals and the general requirements of RIF, as well as to update existing dialects (upwardly compatible). This is in keeping with the working group charter's call for an extensible format.



Other requirements on the framework, and RIF as a whole, are included in this document. Achieving inter -dialect interoperability is, by its very nature, an ill-constrained problem since, by definition, 100% meaning-preserving translations between dialects with different semantics are not likely to exist in most cases. That is not to say that useful inter-dialect "translation" is impossible, only that additional criteria are required in order to formulate precise notions of what satisfactory translation (via interchange of RIF rules) amounts to in such cases. Developing criteria for understanding and managing RIF inter-dialect translations is not within the current phase of RIF working group activity.7 References

[Horty2001]
Agency and Deontic Logic, John F. Horty, Oxford University Press, 2001.

[KS86]
Kowalski, R.A. and M.J. Sergot, A logic-based calculus of events. New Generation Computing, 1986. 4: p. 67-95.

[RIF-DTB] RIF Datatypes[Moore80]
Moore, R.C., Reasoning about Knowledge and Built-Ins 1.0 Axel Polleres,Action, SRI TR-191, 1980.

[OWL-Reference]
OWL Web Ontology Language Reference, M. Dean, G. Schreiber, Editors, W3C Recommendation, 10 February 2004. Latest version available at http://www.w3.org/TR/owl-ref/.

[RIF-BLD]
RIF Basic Logic Dialect (Second Edition) Harold Boley, Michael Kifer, eds. W3C Working Draft, 18 December 2008, http://www.w3.org/TR/2008/WD-rif-dtb-20081218/Recommendation, 5 February 2013, http://www.w3.org/TR/2013/REC-rif-bld-20130205/. Latest version available at http://www.w3.org/TR/rif-dtb/http://www.w3.org/TR/rif-bld/.

[RIF-BLD][RIF-Core]
RIF Basic LogicCore Dialect (Second Edition) Harold Boley, Gary Hallmark, Michael Kifer, Adrian Paschke, Axel Polleres, Dave Reynolds, eds. W3C Working Draft, 30 July 2008, http://www.w3.org/TR/2008/WD-rif-bld-20080730/Recommendation, 5 February 2013, http://www.w3.org/TR/2013/REC-rif-core-20130205/. Latest version available at http://www.w3.org/TR/rif-bld/http://www.w3.org/TR/rif-core/.

[RIF-PRD]
RIF Production Rule Dialect (Second Edition) Christian de Sainte Marie, Adrian Paschke,Gary Hallmark, Adrian Paschke, eds. W3C Working Draft, 18 December 2008, http://www.w3.org/TR/2008/WD-rif-prd-20081218/Recommendation, 5 February 2013, http://www.w3.org/TR/2013/REC-rif-prd-20130205/. Latest version available at http://www.w3.org/TR/rif-prd/.

[RIF-RDF+OWL]8 Appendix: Change Log (Informative)

This appendix summarizes the main changes to this document since its publication as a Working Draft.

Changes since the draft of December 18th, 2008:

  • the section describing the structure of RIF RDFhas been updated with newer RIF documents;
  • all code examples have been removed from the document;
  • each use case concludes by indicating the support of the use case by the current RIF dialects Core, BLD, and OWL Compatibility Jos de Bruijn, editor. W3C Working Draft, 30 July 2008, http://www.w3.org/TR/2008/WD-rif-rdf-owl-20080730/ . Latest version available at http://www.w3.org/TR/rif-rdf-owl/ .PRD. In addition, a brief discussion of the features of the use case that may affect a dialect's support for that use case is sometimes included;
  • an informative change log section has been added;
  • the distinction between general and basic requirements has been removed, thereby flattening the list of requirements.