Aspassia Daskalopulu

The representation of legal contracts

The paper outlines ongoing research on logic-based tools for the analysis and representation of legal contracts, of the kind frequently encountered in large-scale engineering projects and complex, long-term trading agreements. We consider both contract formation and contract performance, in each case identifying the representational issues and the prospects for providing automated support tools.

Towards electronic contract performance

An increasing volume of research in e-commerce is concerned with the development of tools and environments to support various aspects of business-to-business electronic contract formation and performance. This paper is mainly concerned with the latter and takes up the suggestion that automated execution of an agreement between (at least) two parties can be effected through a central control mechanism (a so-called e-marketplace). We revisit modal action logic to model an agreement as a state-based system and specify acceptable and unacceptable states of a business transaction. Unacceptable states result from violations of contractual obligations or prohibitions and call for appropriate recovery mechanisms to be specified, so that they can be enforced by the central control mechanism. We comment on the relations between contract violations and the concepts of fault tolerance and recovery arising in the broader distributed systems context, on the one hand, and contrary-to-duty structures from the (theoretical) deontic logic perspective, on the other.

A constraint-driven system for contract assembly

We present an approach for modelling the structure and coarse content of legal documents with a view to providing automated support for the drafting of contracts and contract database retrieval. The approach is designed to be applicable where contract drafting is based on model-form contracts or on existing examples of a similar type. The main features of the approach are: (1) the representation addresses the structure and the interrelationships between the constituent parts of contracts, bu i not the [ext of the document itselfi (2) the representation of documents is separated from the mechanisms that manipulate it; and (3) the drafting process is subject to a collection of explicitly stated constraints that govern the structure of the documents. We describe the representation of document instances and of ‘generic Llocuments’, which are data structures used to drive the creation of new document instances, and we show extracts from a sample session to illustrate the features of a prototype system implemented in MacProlog,

Modelling legal contracts as processes

This paper concentrates on the representation of legal relations that occur between parties once they have entered a contractual agreement and their evolution as the agreement progresses through time. Contracts are regarded as processes and they are analysed in terms of the obligations that are active at various points during their life span. An informal notation is introduced that summarizes conveniently the states of an agreement as it evolves over time. Such a representation enables us to determine what the status of an agreement is, given an event or sequence of events that concern the performance of actions by the agents involved. This is useful both in the context of contract drafting (where parties might wish to preview how their agreement might evolve) and in the context of contract performance monitoring (where parties might with to establish what their legal positions are once their agreement is in force). The discussion is based on an example that illustrates some typical patterns of contractual obligations.

Computational aspects of the FLBC framework

Recent research has sought to develop formal languages for business communication as more expressive, flexible and powerful alternatives to current electronic data interchange (EDI) standards, with potential benefits both for business-to-business exchanges in e-commerce and for general intra-organizational communication. A prominent approach in this area has become known as the formal language for business communication (FLBC) and is grounded on speech act theory, event semantics, thematic roles, and first-order logic (FOL). In this paper, we discuss some of the specific technical choices for the representation of messages in the original FLBC framework and propose two modifications. The first eliminates a problematic modal logical component from the representations of messages; the second transforms the message representation into Skolemised clausal form. Focusing on two different computational tasks, we illustrate how existing computational methods can be employed directly on the resulting representation for messages. We also propose an alternative formulation for messages using C-logic and discuss possible extensions to the resulting modified FLBC framework, for example, in establishing whether an exchange is meaningful and in compliance with the setting in which the parties have pre-agreed to operate. Finally, we consider some open problems and identify directions for future developments.

On-line analysis and validation of partially occluded images: Implementation and practice

In this paper we describe an implementation of the on-line validation algorithm for the analysis of occluded images, which was developed by Iliopoulos and Simpson [Iliopolous, C.S. and Simpson, J. (1997)]. The algorithm operates on images represented in one dimension as strings and assumes objects within images are of the same length. We also investigate the decomposition of a given image into the set of (perhaps partially occluded) objects occurring in it. We first present the theoretical background to this work and sketch the main components of the analysis and validation method. Then we discuss implementation issues and the testing techniques used and present the test results.