Construction of natural cycletrees

In this article, the following question is answered: Given a cycle C, of size N, how can one compute, in O(N) time, a minimal set of edges E such that adjoining E to the cycle yields a graph with a binary spanning tree having minimal total path length? The answer is given through an algorithm for top-down construction of natural cycletrees, where the structure of each subtree is restricted by a split relation between certain properties of the subtree.     

Bounded quantifications for iteration and concurrency in logic programming

The only means for repetition in most logic programming languages, including Prolog, is recursion. Definite iteration is introduced in logic programming languages through the bounded quantification construct. Firstly, it is claimed that this construct is often, though not always, more natural than recursion for expressing relations that involve repetition. In particular, programs involving arrays and similar data structures are significantly simplified. Secondly, it is argued that bounded quantifications should be efficiently implementable on sequential computers and have a high potential for running in parallel, particularly on computers supporting the SPMD model of computation. Bounded quantifications are compared with related constructs from other languages, including the definite loops of imperative languages and the array comprehensions of recent functional languages.     

Building modular legal knowledge systems

A practical legal knowledge system must be versatile and capable of supporting many fundamentally different aspects of the lawyer's work. In this paper a general framework for building knowledge systems from distinct but communicating modules is proposed. There are currently three different kinds of modules: computation, data storage, and environmental interaction. These modules include inference engines, database managers, and hypertext. Several strategies for coupling these modules are discussed. This framework is used to construct expert systems for two distinct domains: a legal expert system for labour law and a real-time expert system for process control in a pulp plant. The legal application shows that this system can be used to construct an “intelligent library”, guiding the user to relevant documents, rather than merely retrieving documents on request.