. This paper provides an overview of the OCML modelling language: it illustrates the underlying philosophy, describes the main modelling constructs provided, and compares it to other modelling languages. 1. INTRODUCTION OCML 1 was originally developed in the context of the VITAL project (Shadbolt et al., 1993) to provide operational modelling capabilities for the VITAL workbench (Domingue et al., 1993). Over the years the language has undergone a number of changes and improvements and in what follows we will provide an overview of the current version of the language (v5.1), illustrate its underlying philosophy and compare it to other knowledge modelling languages. 2. LANGUAGE TENETS A number of ideas/principles have shaped the development of the OCML language. These are discussed in the following sections. 2.1. Knowledge-level modelling support. The main goal of OCML is to support knowledge-level modelling (Newell, 1982; Fensel and Van Harmelen, 1994). In practice this role impl...

. In this paper we present an approach to document enrichment, which consists of associating formal knowledge models to archives of documents, to provide intelligent knowledge retrieval and (possibly) additional knowledge services, beyond what is available using 'standard' information retrieval and search facilities. The approach is ontology-driven, in the sense that the construction of the knowledge model is carried out in a top-down fashion, by populating a given ontology, rather than in a bottom-up fashion, by annotating a particular document. In the paper we give an overview of the approach and discuss its application to the domains of electronic news publishing, scholarly discourse and medical guidelines. 1. INTRODUCTION An important activity in knowledge management is "to convert text to knowledge" (O'Leary, 1998). This activity is central to knowledge management for two reasons: i) work practices and information flow in organisations tend to be document-centred and ii)...

Abstract. We formally define an abstract executable semantics for the Business Process Execution Language for Web Services in terms of a distributed ASM. The goal of this work is to support the design and standardization of the language. “There is a need for formalism. It will allow us to not only reason about the current specification and related issues, but also uncover issues that would otherwise go unnoticed. Empirical deduction is not sufficient. ” – Issue #42, OASIS WSBPEL TC. The language definition assumes an infrastructure for running Web services on some asynchronous communication architecture. A business process is built on top of a collection of Web services performing continuous interactions with the outside world by sending and receiving messages over a communication network. The underlying execution model is characterized by its concurrent and reactive behavior making it particularly difficult to predict dynamic system properties with a sufficient degree of detail and precision under all circumstances. 1

We review the various arguments which have been advanced for and against the use of executable specifications. Examples are given of the problems which may arise in applying this technique and of the benefits which may accrue. A case study is reported in which execution is used to validate the published specification of a commercially available package. We conclude that there are circumstances when executable specifications can be of high value but that execution must be used together with, and as a supplement to, other methods of validating specifications such as inspection and proof. 1 Introduction Formal specifications have been accepted as having value in a number of areas, including critical systems. A specification that does not correctly capture requirements, however, is of dubious benefit. Validating a specification, whether formal or informal, is known to be difficult. With a formal specification there are a number of techniques available for validation, including r...

Abstract. Electronic institutions are a formalism to define and analyse protocols among agents with a view to achieving global and individual goals. In this paper we propose a definition of norms for electronic institutions and investigate how these norms can be employed for verification and analysis. We offer automatic means to perform the extraction of subparts of an electronic institution in which norms hold true or can safely be avoided. These sub-parts can be used to synthesise norm-aware agents that will pursue or avoid commitments to norms. 1

Abstract. Prototyping is a valuable technique to help software engineers explore the design space while gaining insight on the dynamics of the system. In this paper, we describe a method for rapidly building prototypes of large multi-agent systems using logic programming. Our method advocates the use of a description of all permitted interactions among the components of the system, that is, the protocol, as the starting specification. The protocol is represented in a way that allows us to automatically check for desirable properties of the system to be built. We then employ the same specification to synthesise agents that will correctly follow the protocol. These synthesised agents are simple logic programs that engineers can further customise into more sophisticated software. Our choice of agents as logic programs allows us to provide semi-automatic support for the customisation activity. In our method, a prototype is a protocol with a set of synthesised and customised agents. Executing the prototype amounts to having these agents enact the protocol. We have implemented and described a distributed platform to simulate prototypes. 1.

In this position paper, we give a critical analysis of the deductive and inductive approaches to program synthesis, and of the current research in these fields. From the shortcomings of these approaches and works, we identify future research directions for these fields, as well as a need for cooperation and cross-fertilization between them.

Attempto Controlled English (ACE) is a controlled natural language specifically constructed to write software specifications. ACE specifications are computer-processable and can be unambiguously translated into a first-order logic language. The current version of ACE deals only with singular phenomena. We discuss how ACE can be extended with plurality. The extension proves to be difficult in that plurals are a frequent source of semantic ambiguities. ACE uses a constructive, i.e. completely controlled approach to deal with syntactic and semantic ambiguities. We outline how this strategy can be applied to reduce and eliminate plural ambiguities in ACE.

This paper explores the possibility of using formal ontologies to support detection of conceptual errors in specifications. We define a conceptual error as a misunderstanding of the application domain knowledge which results in undesirable behaviour of the software system. We explain how to use formal ontologies, and in particular ontological constraints, to tackle this problem. We present a flexible architecture based on meta interpretation in logic programming in which the specification is viewed as a multilayer design. We illustrate the significance of this approach for the software and ontology engineering community via example cases in two domains: ecological modelling and process modelling.

This paper presents the ZANS approach to animating a large subset of Z specifications. Unlike most other animation approaches that are based on uncriohal or logical programming paradigms, the approach presented here attempts to transform the specifications into an imperative intermediate language, which can also serve as the basis of code synthesis from Z specifications. ZANS is showing promise of being an effective tool for requirements validation and assisting students learning Z specification languages.