Sujit R NairNovember 30,2009

IntroductionNeed / Requirement.Characteristics of current rule markup

Languages.A sample Scenario of Rule InterchangeFuture Work.Conclusion.

Need / RequirementExpressiveness.Machine-interpretation.Automated Processing.Translation and Interchange.Publication and Serialization.

Current Rule LanguagesRuleML.SWRL.R2ML.W3C RIF.Triple.N3.Jena Rules.Prova.

RuleMLBased on XML.Rules consists of derivation, integrity

constraints, production, reaction, tools and transformation.

Datalog RuleML and Hornlog RuleML.

SWRLCombining Sublanguages of OWL and

RuleML.Union of DLP and Horn Logic.Adds rules at the cost of undecidability and

lack of complete implementation.Protégé.Rules = Antecedent + Consequent.

R2MLBased on concept of RuleML and SWRL.Rules consists of derivation, integrity

constraints, production, reaction.MOF/UML support.

W3C RIFFacilitate rule exchange.Dialects.Basic Logic Dialect(RIF-BLD) ↔ Horn Rule

Language.Datatypes and Built-Ins(RIF-DTB).Core.Production Rule Dialect.

Jena RulesJava Rule object.Jena2 is much simpler, allows rules to be

specified in compact form in text source files.

ProvaWeb rule language + Highly expressive

distributed Web rule engine.Supports complex reaction rule-based

workflow, rule-based event processing, distributed inference services, rule interchange, rule-based decision logic, dynamic access to external data , Web Services and JAVA APIs.

Rule Interchange Sample Using RIF to interchange F-Logic Rules and Drools. Scenario :

To supply a vendor-neutral representation of rules, so that rule-system developers can do their work without concern about a vendor-specific format and in particular without concern about the compatibility with the technology of its business partners.

Jane's e-commerce system uses Drools therefore the rules vocabulary is represented using Java beans

John uses an OWL vocabulary and its rules are represented in F-Logic.

Rule Interchange (contd)The Two rules that are to be implemented :

a. Rule R1: If an item is perishable and it is delivered more than 10 days after the scheduled delivery date then the item will be rejected.

b. Rule R2: If an item is perishable and it is delivered more than 7 days after the scheduled delivery date but less than 14 days after the scheduled delivery date then a discount of 18.7% will be applied to this delivery.

Rule Interchange (contd)Points to be kept in mind:

RIF needs to deal with different vocabularies.

RIF needs an uniform mechanism to address vocabulary elements. The usage of URI's may be such a mechanism.

Vocabulary and rules are separate layers

Rule Interchange (contd)John's OWL vocabulary: <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-

syntax-ns#" xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#" xmlns:owl="http://www.w3.org/2002/07/owl#" xmlns="http://www.example.org/JohnSystem/vocabulary">

<owl:Class rdf:ID="Item"/> <owl:DatatypeProperty rdf:ID="perishable"> <rdfs:domain rdf:resource="#Item"/> <rdfs:range rdf:resource="xs:boolean"/></owl:DatatypeProperty>

Rule Interchange (contd)<owl:DatatypeProperty rdf:ID="actualDeliveryDate">

<rdfs:domain rdf:resource="#Item"/> <rdfs:range rdf:resource="xs:date"/> </owl:DatatypeProperty> <owl:DatatypeProperty rdf:ID="scheduledDeliveryDate">

<rdfs:domain rdf:resource="#Item"/> <rdfs:range rdf:resource="xs:date"/> </owl:DatatypeProperty> <owl:DatatypeProperty rdf:ID="status"> <rdfs:domain rdf:resource="#Item"/> <rdfs:range rdf:resource="Status"/>

</owl:DatatypeProperty>

Rule Interchange (contd) <owl:DatatypeProperty rdf:ID="discount">

<rdfs:domain rdf:resource="#Item"/>

<rdfs:range rdf:resource="xs:double"/>

</owl:DatatypeProperty>

<owl:Class rdf:ID="Delivery"/>

<owl:Class rdf:ID="Status">

<owl:oneOf rdf:parseType="Collection"> <rdf:List>

<rdf:first rdf:datatype="xs:string">rejected</rdf:first> <rdf:rest>

<rdf:first rdf:datatype="xs:string">accepted</rdf:first> </rdf:rest> </rdf:List>

</owl:oneOf>

</owl:Class>

</rdf:RDF>

Rule Interchange (contd)John Rules (F-Logic)

//If an item is perishable and it is delivered more than 10 days after the scheduled delivery date then the item will be rejected RULE R1 I:item[status -> "rejected"] <-

I:item[isPerishable -> true] AND I[actualDeliveryDate -> A] AND

I[scheduledDeliveryDate -> S] AND R is (A - S) AND R > 10.

Rule Interchange (contd) //If an item is perishable and it is delivered more than 7 days after the scheduled delivery date but less than 14 days after the scheduled delivery date then a discount of 18.7% will be applied to this delivery. RULE R2 I:item[discount -> 18.7] <-

D:delivery[hasItems->>Items] AND I:item[isPerishable -> true] AND I[actualDeliveryDate -> A] AND I[scheduledDeliveryDate-> S] AND member(I, Items) AND R is (A - S) AND R > 7.

Rule Interchange (contd)Jane's Rules (Drools)

package com.sample

import com.sample.Item; rule "R1" when i :

Item( isPerishable==true, actualDeliveryDate : actualDeliveryDate, scheduledDeliveryDate :

scheduledDeliveryDate ) eval( actualDeliveryDate.getDay() – scheduledDeliveryDate.getDay() > 10 ) then i.isRejected(true); modify(i); end

Rule Interchange (contd)rule "R2" when d:Delivery(hasItems: hasItems) i : Item(actualDeliveryDate : actualDeliveryDate, scheduledDeliveryDate :

scheduledDeliveryDate ) eval( (actualDeliveryDate.getDay() – scheduledDeliveryDate.getDay() > 7) && hasItems.contains(i)) then i.setDiscount(18.7); modify(i); end

Rule Interchange (contd)Importing Jane's Rules in the John's rule

systemTranslating from Drools into RIF Presentation Syntax proposed by RIF-BLD is

used to perform the vocabulary interchange.

Rule Interchange (contd)Translation of Jane's Drools Rules rules into

RIFrule "R1" when i :

Item(isPerishable==true, actualDeliveryDate :actualDeliveryDate, scheduledDeliveryDate :

scheduledDeliveryDate ) eval( actualDeliveryDate.getDay() – scheduledDeliveryDate.getDay() > 10) then i.isRejected(true); modify(i); end

Rule Interchange (contd)// Translation to RIF Rule ("http://jane.com/R1"  ?i#Item[(isRejected->"true"^^xs:boolean) :- And(?i#Item[(isPerishable->"true"^^xs:boolean) (actualDeliveryDate->?actualDeliveryDate ) (scheduledDeliveryDate ->?scheduledDeliveryDate)] op:numeric-greater-than( op:numeric-subtract( user-defined:getDay(?actualDeliveryDate), user-defined:getDay(?scheduledDeliveryDate) ), "10"^^xs:int ) ) )

Future WorkOn going research to develop a general rule

mark up language.Most of the research is concentrating on

RuleML and RIF.To cover the shortcomings such as –

procedural call to external objects, operating systems , terminological descriptions for dealing with real world distributed Web Applications.

ConclusionWhy is rule markup needed ?Current rule markup languages.RuleML and RIF.W3C RIF BLD provides a robust core for the

interchange of business rules among commercial and academic rule systems.

Embodies both production rules and derivation rules.

References1. Adrian Paschke , Harold Boley – Rule Markup

Languages and SWRL.2. W3C Rule Interchange Format,

http://www.w3.org/2005/rules/wiki/RIF_Working_Group

3. RIF Basic Logic Dialect, http://www.w3.org/TR/rif-bld/

4. W3C RIF Use Cases and Requirements, http://www.w3.org/TR/rif-ucr/

Gary Hallmark , Christian de Sainte Marie, Marcos Didonet Del Fabro, Patrick Albert , and Adrian Paschke - Please Pass the Rules: A Rule Interchange Demonstration

Contact InformationSujit Raveendran Nair.Email: srn071000@utdallas.edu.Phone: 972-983-4886.