Logical Representation of Legal Rules

Andrew J I Jones

King’s College London, Dept of Computer Science

The talk will focus on two related groups of questions:

  1. The early 1980’s work of the Logic Programming Group at Imperial College on the British Nationality Act (BNA) illustrated the power of elementary logic as a tool for formally representing legal rules, and led to the development of a knowledge-based system (KBS) capable of providing answers to questions of the type “Is person Y a British citizen ?” To what extent can it be said that more recent designs for rule-based KBS’s in legal/administrative domains – and in particular the approach of Haley Ltd (formerly RuleBurst, formerly SoftLaw) – have improved on the BNA work ? Moreover, do we find here an adequate treatment of open texture, and are there satisfactory means for distinguishing between routine cases and hard cases ?
  2. Since the beginning of work on legal KBS’s, there has been discussion of the potential role of deontic logic (better labelled normative logic) in legal knowledge representation. Do we now have a clearer picture of the extent to which the legal knowledge engineer needs to take account of the central problems of normative logic?