We show how to interoperate, semantically and inferentially, between the leading Semantic Web approaches to rules (RuleML Logic Programs) and ontologies (OWL/DAML+OIL Description Logic) via analyzing their expressive intersection. To do so, we define a new intermediate knowledge representation (KR) contained within this intersection: Description Logic Programs (DLP), and the closely related Description Horn Logic (DHL) which is an expressive fragment of first-order logic (FOL). DLP provides a significant degree of expressiveness, substantially greater than the RDFSchema fragment of Description Logic.

We address the problem of authorization in large-scale, open...

This paper investigates transformations and normal forms in the context of Defeasible Logic, a simple but efficient formalism for nonmonotonic reasoning based on rules and priorities. The transformations described in this paper have two main benefits: on one hand they can be used as a theoretical tool that leads to a deeper understanding of the formalism, and on the other hand they have been used in the development of an efficient implementation of defeasible logic

We give a new, implemented approach for automating the negotiation of business contracts. We use our previous work on developing a declarative language for expressing and reasoning about contracts and negotiations. Here we newly extend it to include a knowledge base of rules about negotiation structures and auctions. This work addresses three important research questions. First, how can we represent information to allow automatic inference of negotiation structures? Second, how can we automate negotiations in a way that will closely drive a realistic automated platform (the Michigan Internet AuctionBot)? Third, how can we use auction results to form a final contract? We use our work on Courteous Logic Programs, a form of logic-based knowledge representation, as a way to express fully-specified, executable

The simple event-condition-action (ECA) rule paradigm of active databases has proved very useful in many AI and database applications. However, its applicability goes beyond data management. ECA rules can be used in network management and monitoring, electronic commerce, security and access management, and other application areas to express policies-- collections of general principles specifying the desired behavior of a system. In this paper we use a declarative policy description language PDL, in which policies are formulated as sets of ECA rules. The main contribution of the paper is a framework for detecting action conflicts and finding resolutions to these conflicts. Conflicts are captured as violations of action constraints. The semantics of rules, and conflict detection and resolution are defined axiomatically using logic programs. Given a policy and a set of action constraints the framework defines a monitor that filters the output of the policy to satisfy the constraints. We briefly describe the architecture of a PDL-based policy server being used to provide centralized administration of a soft switch in a communication network and show how it can be augmented to handle conflict resolution.

Abstract. Business rules are statements that express (certain parts of) a business policy, defining business terms and defining or constraining the operations of an enterprise, in a declarative manner. Since these rules define and constrain the interaction among business agents in the course of business processes, they have to refer to the components of their mental state, such as the knowledge/information and the commitments of an organization. We propose an agent-oriented approach to business rules and show how to represent and visualize business rules and business processes in Agent-Object-Relationship modeling. 1

In this work, we have been principally concerned with the representation of contracts so that their normative state may be tracked in an automated fashion over their deployment lifetime. The normative state of a contract, at a particular time, is the aggregation of instances of normative relations that hold between contract parties at that time, plus the current values of contract variables. The effects of contract events on the normative state of a contract are specified using an XML formalisation of the Event Calculus, called ecXML. We use an example mail service agreement from the domain of web services to ground the discussion of our work. We give a characterisation of the agreement according to the normative concepts of: obligation, power and permission, and show how the ecXML representation may be used to track the state of the agreement, according to a narrative of contract events. We also give a description of a state tracking architecture, and a contract deployment tool, both of which have been implemented in the course of our work. 1

Abstract. Commitments are a powerful representation for modeling multiagent interactions. Previous approaches have considered the semantics of commitments and how to check compliance with them. However, these approaches do not capture some of the subtleties that arise in real-life applications, e.g., e-commerce, where contracts and institutions have implicit temporal references. The present paper develops a rich representation for the temporal content of commitments. This enables us to capture realistic contracts and institutions rigorously, and avoid subtle ambiguities. Consequently, this approach enables us to reason about whether and when exactly a commitment is satisfied or breached and whether it is or ever becomes unenforceable. 1

We give an overview of current eorts to standardize e-business rules knowledge representation (KR) in XML as part of the Semantic Web.

Abstract — Outsourcing of complex IT infrastructure to IT service providers has increased substantially during the past years. IT service providers must be able to fulfil their service-quality commitments based upon pre-defined Service Level Agreements (SLAs) with the service customer. They need to manage, execute and maintain thousands of SLAs for different customers and different types of services, which needs new levels of flexibility and automation not available with the current technology. The complexity of contractual logic in SLAs requires new forms of knowledge representation to automatically draw inferences and execute contractual agreements. A logic-based approach provides several advantages including automated rule chaining allowing for compact knowledge representation as well as flexibility to adapt to rapidly changing business requirements. We suggest logical formalisms for the representation and enforcement of SLA rules and describe a proof-of-concept implementation. The article describes selected formalisms of the ContractLog KR and their adequacy for automated SLA management and presents results of experiments and examples from common industry use cases to demonstrate the expressiveness of the language and the scalability of the approach.