1. The RuleML Initiative, July/August 2001 International Semantic Web Working Symposium SWWS-01 30 July - 1 August 2001, Stanford, California, USA Harold Boley, Said Tabet and Gerd Wagner Design Rationale of RuleML: A Markup Language for Semantic Web Rules

2. The RuleML Initiative, July/August 20012 Introduction and Background The RuleML Initiative as a Web Ontology Effort Modular Syntax & Semantics of RuleML RuleML DTDs: release 0.8 Negation Handling in RuleML Priorities/Evidences in RuleML RuleML Implementations via XSLT & Rule Engines Example: A Semantic Web Scenario in Insurance Conclusions Agenda

3. The RuleML Initiative, July/August 20013 Introduction and Background Semantic Web rules less studied than corresponding ontology (taxonomy) markup Rule Markup Initiative fills this gap by exploring rule systems (e.g., extended Horn logics) suitable for the Web: Syntax (XML and RDF), semantics, tractability/efficiency, transformation, and compilation Derivation rules: may be evaluated bottom-up as in deductive databases, top-down as in logic programming, or by tabled resolution as in XSB Reaction rules: also called "ECA" -- “Event-Condition-Action" -- or “Trigger" rules Possible combinations  RuleML 

4. The RuleML Initiative, July/August 20014 The RuleML Initiative as a Web Ontology Effort RuleML Initiative: started in August 2000 during the Pacific Rim International Conference on Artificial Intelligence (PRICAI 2000) February/March 2001: First RuleML BOF at W3C Plenary and WG Meeting event Ontology ‘equation’: Ontology = Taxonomies + Axioms (with Axioms having the form of Rules) gives big picture System of sublanguages: from RDF-like triples to a labeled Horn logic with equations plus URI individuals and relations

5. The RuleML Initiative, July/August 20015 Modular Syntax & Semantics of RuleML RuleML hierarchy top-level: 1.Integrity constraints: reaction rules that signal inconsistency when certain conditions are fulfilled 2.Derivation rules: reaction rules whose action happens to only 'assert' a conclusion when certain conditions (premises) are fulfilled 3.Facts: derivation rules with empty conjunction of premises

6. The RuleML Initiative, July/August 20016 Modular Syntax & Semantics of RuleML (Cont’d) urc-bin-data-ground-fact urc-bin-data-ground-log urc-bin-datalog bin-datalogurc-datalog ur-datalog ur-hornlog ur-equalog hornlog equalog datalog ur Rooted DAG will be extended with branches for further sublanguages URL/URI-like ‘ur’-objects derivation rules RDF- like triples ur-datalog = join(ur,datalog) Sublanguage hierarchy: RDF Rules

7. The RuleML Initiative, July/August 20017 Modular Syntax & Semantics of RuleML (Cont’d) Separation of concerns: Sublanguage hierarchy: 12 sublanguages together constitute modularized basic RuleML definition. Except 'UR' (URL/URI) group correspond to well-known rule systems, each with semantic (model- and proof-theoretic) characterization Concrete markup: In recent months, RuleML 0.7 DTDs have been developed into RuleML 0.8 DTDs without affecting the above semantics. The new markup uses XML in RDF's 'explicit role- markup' style, relativizing XML's positionality to places where RDF's Seq containers or DAML+OIL lists are used

8. The RuleML Initiative, July/August 20018 RuleML DTDs: release 0.8 full RDF-like triple: Advantage of roles is object-centered modeling: If some item is to be added to a fact or atom, then this is easy to attach, RDF-like Item insertion, XML-like, into child sequence would cause all subsequent children to assume a new position (problem for XSLT) roles Concrete markup:

9. The RuleML Initiative, July/August 20019 Negation Handling in RuleML IFisPresent(?someCar) ANDNOT isAssignedToRentalOrder(?someCar) ANDNOT requiresService(?someCar) AND… THEN isAvailable(?someCar) The Closed-World Negation NOT UML Diagram:

10. The RuleML Initiative, July/August 200110 Negation Handling in RuleML (Cont’d) isPresent Car isAssignedToRentalOrder Car... NOT in RuleML: an example

11. The RuleML Initiative, July/August 200111 Negation Handling in RuleML (Cont’d) NOT = non-truth (or failure) NEG = falsity Default rules: IFNOT hasApproval(?URL) THENNEG isOfficialDocument(?URL) Open-World Reasoning with NOT and NEG

12. The RuleML Initiative, July/August 200112 Priorities/Evidences in RuleML Quantitative Priorities: Static numerical salience Dynamically calculated priorities Qualitative Priorities Using the Overrides Fact over rule labels

13. The RuleML Initiative, July/August 200113 Priorities/Evidences in RuleML (Cont’d) beginners 0.75....... customerUnder25 customer Static Salience Example:

14. The RuleML Initiative, July/August 200114 Priorities/Evidences in RuleML (Cont’d) Dynamic Salience Example: beginners calculateSalience....... customerUnder25 customer

15. The RuleML Initiative, July/August 200115 RuleML Implementations via XSLT & Rule Engines XSLT: is a Rule Based Language is a Transformation Tool for RuleML Knowledge Bases (KB): Using Style sheets to exchange RuleML KBs Implementations: With GEDCOM, Mike Dean created the first operational RuleML (0.7) rulebase, where rules on family relationships (child, spouse, etc.) are run via XSLT translators to the XSB, JESS, and N3/cwm engines With Mandarax RuleML, Jens Dietrich has implemented the first complete input-processing-output environment for RuleML (0.8)

16. The RuleML Initiative, July/August 200116 A Semantic Web Scenario in Insurance A teenager after her first car accident: how much will my premiums increase and how does this accident affect my insurance policy? Principle: Uniform RuleML representation of derivation rules and underlying document metadata

17. The RuleML Initiative, July/August 200117 A Semantic Web Scenario in Insurance (Cont’d) beginners 0.75 calculatePremium customer 40 InsurancePolicy customer insurance lifeEvent customer accident report customerUnder25 customer

18. The RuleML Initiative, July/August 200118 A Semantic Web Scenario in Insurance (Cont’d) family 0.9 calculatePremium customer 0 InsurancePolicy customer insurance lifeEvent customer accident report FamilyAutoPlan customer familyauto

19. The RuleML Initiative, July/August 200119 A Semantic Web Scenario in Insurance (Cont’d) Formalizing the relevant facts Olivia is under 25 Olivia has an insurance policy and this document has link.../IMA-0835: Olivia is in a family auto plan and this document has link.../FMA-0142: Olivia's accident report is available at TrafficReport.biz : FamilyAutoPlan Olivia LifeEvent Olivia accident InsurancePolicy Olivia customerUnder25 Olivia

20. The RuleML Initiative, July/August 200120 A Semantic Web Scenario in Insurance (Cont’d) Conflict Resolution: using Meta facts (a la BRML) beginners... family... Overrides family beginners

21. The RuleML Initiative, July/August 200121 A Semantic Web Scenario in Insurance (Cont’d) Conflict Resolution: using Meta facts (a la BRML) beginners... family... Overrides family beginners

22. The RuleML Initiative, July/August 200122 Conclusions RuleML rulebases embedded in, or referring to, XML and RDF documents. Using RuleML in other XML namespaces (like for, say, MathML), incl. RDF(S) namespaces (ruleml: namespace prefix) RuleML rule premises could be DAML+OIL concept descriptions or UML object descriptions RuleML derivation rules integrated with reaction rules, e.g. Situated LP or ECA Framework (see SpiritSoft Demo) RuleML and RDF Query talking about a joint Rule and Query effort as part of W3C Ontology Working Group Ontologies: The big Picture and future RuleML Versions

23. The RuleML Initiative, July/August 200123 Conclusions (Cont’d) IJCAI 01: two tutorials, a workshop and an invited talk, August 2001, Seattle, USA ICEC 01 (International Conference on Ecommerce) panel, November 2001, Vienna, Austria Dagstuhl seminar on Rule Markup Techniques: February 2002, Schloss Dagstuhl, Germany Some RuleML events