Semantic Web Rules with Ontologies, and their E-Services Applications
Presented by B. Grosof, M. Kifer, and M. Dean
Detailed Description of ISWC-2005 Conference Tutorial (half-day)
Preliminary version of Sept. 15 2005
Goals: Rules are a main emerging area of the Semantic Web. There has been significant progress in recent years in several aspects of Semantic Web rules. This includes exciting developments in the underlying knowledge representation formalisms as well as advances in integration of rules with ontologies; translations between heterogeneous commercial rule engines; development of open-source tools for inferencing and interoperability; standards proposals (including RuleML and SWRL); proposals for rule-based semantic Web services; and pilot applications in the emerging area of e-services. This tutorial will provide an introduction to these developments and will explore techniques, requirements, applications, and challenges, as well as the current commercial scene in rules and semantic web overall. We will also touch upon the issues of business value, adoption, investment, and strategy considerations.
Potential Audience: Most of the ISWC audience, especially those interested in rules and their applications in Semantic Web and semantic Web services in particular. This includes researchers interested in core technologies and developers interested in applications. No background knowledge is required. Helpful but not required are: the basics of XML, RDF, and OWL; and the basics of logical knowledge representation (relational DBMS, logic programs, and/or first order logic).
A. Core – KR Languages & Standards (with examples throughout)
a. Overview and get acquainted
b. Uses of rules in current commercial systems and current semantic web
c. Current commercial rule systems:
Prolog, SQL databases, production rules (including Jess),
event-condition-action rules, others
d. Current semantic web rule languages, systems, tools, and applications
e. Desired/envisioned uses of rules in semantic web, including services
f. High-level requirements for semantic web rules
g. Advantages and value of rules in IT systems/applications specification,
development, maintenance, integration
2. Overview of Logical Knowledge Representations and Standards
a. First Order Logic (FOL), Logic Programs (LP), Description Logic (DL),
Higher Order Logic (HOL)
b. Rule Markup/Modeling Language (RuleML), Semantic Web Rules Language (SWRL),
Common Logic (formerly KIF), OWL, RDF
3. Horn Logic / Horn LP
KR theory, algorithms, computational complexity
4. Nonmonotonic LP
a. Negation As Failure: Ordinary LP (& pure Prolog)
- ubiquity in commercial rule systems
- Well founded semantics, other semantics, stratification, algorithms,
computational complexity, closed vs. open world
b. Priorities: Courteous LP; Defeasible Logic; Inheritance
- ubiquity of priorities in commercial rule systems
- KR theory, algorithms, computational complexity, IBM CommonRules and
- bases for priority: recency, authority, specificity, reliability
- merging and updating
5. Procedural Attachments:
- ubiquity in commercial rule systems
- built-ins, web queries, sensing in Situated LP
- actions, effecting in Situated LP; combination with Courteous
- hookup to web services, cwm
6. Production Rules
- commercial dominance; OO embedding
- agenda, salience, stratification, NAF
- OMG effort
- relationship to RuleML; SweetRules
7. Frame Logic (F-Logic, F-Logic Programs)
- Object oriented features: frame syntax, slots
8. Hilog and quasi higher-order expressiveness
- RDF-Full and OWL-Full
9. Lloyd-Topor enriched connectives and quantifiers
- nonmonotonic (relying on NAF)
a. Sorted Logic: classical, LP
b. XML-Schema datatypes, incl. hierarchy
c. Datatypes in RDF, OWL, SWRL, RuleML
11. RuleML and SWSL, part 2
- presentation syntax
- KB merging; query answering
12. Combining Rules with Ontologies
a. Overview of relationships:
Rules on top of ontologies, rules to represent ontologies,
rules to map between ontologies.
b. Description Logic Programs and DLP-Fusion: overlap of LP and DL
- represent ontologies via rules, translate DL to LP
- KR, expressive features, algorithms, computational complexity
- tools: SweetOnto, others
- use cases, advantages of working in LP vs. DL
c. SWRL Approach: OWL plus Horn expressiveness
- syntax and semantics
- KR, expressive features, algorithms, computational complexity
- tools: Hoolet, FOL reasoners
d. Default Inheritance
- ubiquity in object-oriented programming languages
- requirements of semantic web service process ontologies
- Represent ontologies using nonmonotonic LP rules
- Courteous Inheritance approach; process ontologies, Process Handbook
- FLORA-2 approach
e. Integrity Constraints
- cut model vs. notify
- alternatives to Description Logic
f. Hypermonotonic Reasoning
- view Courteous LP as weakened FOL
- case study: SWSO PSL treatment
- motivations, relationships to other efforts
14. Other approaches and issues in current rule languages and systems
a. Existentials, skolemization, RDF blank-nodes,
b. Equality and equivalence reasoning
d. Relationship of rules to RDF query/access languages and tools
B. Tools -- SweetRules, Jena, cwm, and More
(organized as historical progression of tools:)
1. commercially important pre-SW rule systems -- reminder from core: focus here on
- open source -- XSB, SWI, Jess, CLIPS, DBMS
- rule management; JSR 94 Java API’s
2. Overview of SW Rule Generations:
3. 1st generation: Rudimentary Interoperability and XML/RDF Support (brief)
- CommonRules, SweetRules V1, OWLJessKB
4. 2nd Generation: Rule Systems within RDF/OWL Toolkits
a. cwm and N3; builtins, incl. WS calls
b. Jena-2 (in detail)
c. list of other SW rules tools:
- OO JDrew, Flora, hoolet, Triple, ...
5. 3rd Generation: SW Rule Integration and Life Cycle
a. SweetRules V2 (in detail)
- integration capabilities and architecture,
standard rule+ontology repn's, more rule lifecycle support
C. Applications in Services, including Policies, Contracts, Mediation & Integration
1. Applications in Semantic Web Services
- high level concept, business motivations
- framework to view the applications generally
- service descriptions, SWSL requirements analysis
- SWSI’s SWS Framework (SWSF)
- policies cluster of tasks in contracting, discovery, monitoring, etc. etc.
- process model cluster of tasks in composition etc.
- SWSI Application Scenarios (in detail)
- WSMO, WSML, WSMX
- challenge: reasoning about action
2. Applications in Service Mediation: Ontology/Context Translation and Info Integration
a. matching; expansion, enhanced expressiveness in ontology specification; SWRL
b. Financial services, XBRL business reporting standard, accounting,
ECOIN system, equational ontologies, context integration
3. Applications in End-to-End E-Contracting Services and Business Process Automation
a. pricing, ordering: in B2B/supply chain, B2C
b. SweetDeal Approach: rule-based contract modules; exception handling,
negotiation, supply chains, auctions
c. Workflow, customer relationship management, more about monitoring
d. process ontologies/descriptions, Process Handbook
4. Applications in Authorization and Trust Services using Policies
a. Authorization, Security, Trust, Access Control, Privacy
- examples: credit, health records
- delegation in distributed trust management
- XACML access control standard, P3P (APPEL) privacy standard,
Role Based Access Control
b. Justifications and Proofs on semantic web; InferenceWeb
5. Prospective early adopter areas for semantic web rules in e-business,
strategic considerations, market evolution, entrepreneurial opportunities
6. Windup and Discussion
Other Comments including Recent History in Rules and
Motivations for the Tutorial:
After ontologies and RDF query/access, rules is the most important frontier area today for the Semantic Web core technology and standards. There are a number of exciting research issues, most semantic web researchers (and developers) are not yet up to speed in this area, and this half-day tutorial will help them get there.
During the last half year, interest and activities in Semantic Web rules have been exploding – on several fronts. In the last year, there has been great progress on: the Semantic Web Services Framework from SWSI (which includes a huge role for Rules and their combination with ontologies); the SweetRules open source toolset platform, including expanded services support and a deeper set of prototyped application scenarios; the FLORA-2 open-source knowledge representation system; the WSMO effort; the OMG standardization front (e.g., Production Rules & RuleML); and the W3C standardization front (e.g., Workshop on Rule Languages for Interoperability). The Workshop on Rules and Rule Markup Languages (RuleML-2004 last year), that was held the last three years colocated with ISWC, is becoming a full Conference this year. (Grosof is General Co-Chair for it, by the way.) As another example indicator, there were 71 accepted position papers at the hastily-arranged W3C Workshop on Rules Languages for Interoperability in April 2005; with about half being from research-y types (more than half of papers/participants were from companies/government).
This Tutorial will respond to those developments. As compared to the rules tutorial at ISWC-2004, the focus will include even more emphasis specifically on: Services, including Semantic Web Services, drawing on design and application work done by SWSI and WSMO; how to combine rules with ontologies, since that has been a major focus of work during the last year in the whole field including in SWSI; and tools and standardization.
This tutorial will also respond to the Call For Tutorials, including the Call's list of desiderata:
(1) between two major areas of the semantic web -- rules and ontologies; and
(2) between multiple existing disciplines of computer science: knowledge representation, agents, software engineering, and database-y information integration.
SHORT CV OF THE PRESENTERS, including background in the tutorial area, previous tutorials presented, and evidence of teaching experience:
Benjamin Grosof is Assistant Professor in Information Technology (IT) at MIT Sloan School of Management. His research is to create and study knowledge-based IT for e-commerce applications. He focuses especially on the technologies, business applications, and strategies for Semantic Web Services (SWS), the convergence of Web Services and Semantic Web. SWS is the next major generation of the Web, in which e-services and business communication become more knowledge-based and agent-based. The pioneer of inter-operable XML business rules, he co-leads the RuleML emerging industry standards effort. He has led several fundamental contributions to knowledge representation theory and technologies in semantic web rules, including the development of Situated Courteous Logic Programs, their interoperability with production rules, and the SweetRules open source tool platform. His research also includes several application areas for rule-based SWS in business process automation: e-contracting, which he has pioneered; financial information and reporting; and business policies, e.g, for trust and security. He is Principal Investigator and Rules co-lead in the DARPA Agent Markup Language (DAML) program, and a core participant in the Semantic Web Services Initiative that is creating emerging SWS standards (area chair in of Contracts & Negotiation, co-chair of Industrial Partners, and co-designer of the Language). He interacts extensively with industry, including to do consulting in areas related to his research and standards activities.
He joined MIT Sloan in July 2000. Previously, he was a senior research scientist, in software, at IBM T.J. Watson Research Center (12 years there), where most recently he conceived and led IBM CommonRules and co-led its application piloting for rule-based XML agent contracting in EECOMS, a $29Million NIST industry consortium project on manufacturing supply chain management. His notable technical contributions also include fundamental advances in rule-based intelligent agents, conflict handling for rules, rule-based security authorization, and integration of rules with machine learning. He is author of over 50 refereed publications, two major industry software releases, and a patent. He holds a PhD in Computer Science from Stanford University, and a BA in Applied Mathematics from Harvard University.
Prof. Grosof has given numerous talks on the Semantic Web. As a regular teaching professor at MIT for the last 4 academic years, he has developed and taught a range of MIT courses that include substantial focus on semantic web for half-semester, or that have total focus on semantic web at lengths of 3-day, 8-hour, 3-hour, and 1.5-hour. He presented (with Y. Labrou) the half-day International Joint Conference on Artificial Intelligence (IJCAI-01) tutorial "Agent Communication in Knowledge Based Electronic Markets" (50+ attendees, reported in nationally syndicated Toronto Star news article). He gave a half-day ACM Conference on Electronic Commerce (EC '04) tutorial "E-Commerce Applications of Semantic Web Services" on May 17, 2004. He gave, with Mike Dean, a half-day ISWC-2004 Tutorial on “Semantic Web Rules with Ontologies, and their E-Business Applications” (~50 attendees). He co-chaired the EC '03 conference tutorial program, and chaired the WWW-2003 panel "Semantic Web Services". He was a Senior Program Committee member for ISWC-2004. He was WWW-2001 program area co-chair for the Security and E-Commerce area. He is general co-chair for RuleML-2005 (International Conference on Rules and Rule Markup Languages for the Semantic Web).
Michael Kifer is a Professor of Computer Science at State University of New York, Stony Brook. He is co-chair of SWSL, the Semantic Web Services Initiative’s Language Committee, and a member of the RuleML Steering Committee. He serves on the editorial boards of Journal of Intelligent Information Systems, Theory and Practice of Logic Programming, and Web Semantics; he was also a Chair and a committee member of a number of conferences. He has made several fundamental contributions to rules and knowledge representation theory and technologies, including the development of F-Logic, HiLog, Transaction Logic, and the FLORA-2 open source rule system. For this work he received the prestigious1999 and 2002 Test of Time Awards from ACM SIGMOD.
Professor Kifer has two decades of teaching experience in computer science. He is a co-author of three textbooks, including the recent Database Systems: An Application-Oriented Approach. He holds an M.S. in Mathematics from Moscow University, Russia, and a PhD in Computer Science from Hebrew University of Jerusalem, Israel.
Mike Dean is a Principal Engineer at BBN Technologies and Principal Investigator for the DAML Integration and Transition effort within the DARPA Agent Markup Language (DAML) program. He chairs the Joint US/EU ad hoc Markup Language Committee responsible for the DAML+OIL and SWRL languages, edited the OWL Web Ontology Language Reference, was a member of the W3C RDF Core and Web Ontology Working Groups, and is a member of the RuleML Steering Committee and the Architecture Committee of the Semantic Web Services Initiative. Dean is the developer of a number of Semantic Web tools and reference data sets and has been actively using SWRL in a variety of Semantic Web applications. He holds a B.S. in Computer Engineering from Stanford University.
Mr. Dean has given numerous talks on the Semantic Web, including an early tutorial "DAML+OIL for Application Developers". He gave, with Benjamin Grosof, a half-day ISWC-2004 Tutorial on “Semantic Web Rules with Ontologies, and their E-Business Applications” (~50 attendees).
For a list of some references to the presenters' published work in the area, see (E.) below, esp. just do keyword search within-page on the SWSF report’s references (http://www.daml.org/services/swsl/report/applications/#sec-references ). See also the authors’ webpages. (for Grosof: http://ebusiness.mit.edu/bgrosof/#RecentPapersByTopic ) . Also Grosof & Dean have led the development of SweetRules http://sweetrules.semwebcentral.org and Kifer has led the development of FLORA-2 http://flora.sourceforge.net , the two leading open source software packages for semantic web rules.
RESOURCES -- SUPPORT MATERIAL to be given to the attendees
A list of papers and resources available on the web will be provided to the attendees, in addition to the usual tutorial slideset of course.
The following papers, available on the web, cover major portions of the tutorial's content (altogether roughly half):
- "Representing E-Commerce Rules Via Situated Courteous Logic Programs in RuleML", by B. Grosof, Electronic Commerce Research and Applications (ECRA) 3(1):2-20, Spring 2004.
- “Semantic Web Services Framework” (SWSF), V1.0+, by Battle, S., Bernstein, A., Boley, H., Grosof, B., Gruninger, M., Hull, R., Kifer, M., Martin, D., McIlraith, S., McGuinness, D., Su, J., and Tabet, S. (alphabetic), May 2005. Technical Report (~200 pages).
- “Logical Foundations of Object-Oriented and Frame-Based Languages”, by M. Kifer, G. Lausen, and J. Wu, .J. ACM 42:741-843, 1995.
- "SweetDeal: Representing Agent Contracts with Exceptions using Semantic Web Rules, Ontologies, and Process Descriptions", by B. Grosof and T. Poon, International Journal of Electronic Commerce (IJEC) 8(4):61-98, Summer 2004.
- “HiLog: A Foundation for Higher-Order Logic Programming”, by W. Chen, M. Kifer, and D.S. Warren, J. Logic Programming 15(3):187-230, Feb. 1993.
- "Description Logic Programs: Combining Logic Programs with Description Logic", by B. Grosof, I. Horrocks, R. Volz, and S. Decker, Proc. 12th Intl. Conf. on the World Wide Web (WWW-2003), 2003.
- "SWRL: A Semantic Web Rules Language Combining OWL and RuleML", V0.7+, by I. Horrocks, P. Patel-Schneider, H. Boley, S. Tabet, B. Grosof, and M. Dean, Nov. 2004. Technical Report.
- RuleML website, especially design documents and list of tools. Ed. by H. Boley, B. Grosof, and S. Tabet, 2001-present.
Content for the tutorial will also be drawn, to a lesser degree, from about a dozen other papers/resources available on the web, e.g.,:
- “Web Service Modeling Ontology (WSMO)” by J. de Bruijn et al., 2005. Technical Report.
- "A Declarative Approach to Business Rules in Contracts: Courteous Logic Programs in XML", by B. Grosof et al., Proc. EC-99.
- “A Policy Based Approach to Security for the Semantic Web”, by Kagal et al., Proc. ISWC-2003.
- "Financial Information Integration in the Presence of Equational Ontological Conflicts", by A. Firat et al., WITS 2002 conf.
- "DAML+OIL for Application Developers", http://www.daml.org/2002/03/tutorial/Overview.html
- "Delegation Logic: A Logic-based Approach to Distributed Authorization", ACM Trans. on Info. Systems Security (TISSEC), by N. Li et al., 2003