Hajime Yoshino

In order to represent legal knowledge adequately, it is vital to create a formal device that can freely construct an individual concept directly from a predicate expression. For this purpose, a Compound Predicate Formula (CPF) is formulated for use in legal expert systems. In this paper, we willattempt to explain the nature of CPFs by rigorous logical foundation, i.e., establishing their syntax and semantics precisely through the use of appropriate examples. We note the advantages of our system over other such systems and discuss the significance of CPFs with regard to the formalization of legal reasonings using examples from the United Nations Convention for the International Sale of Goods.

In a legal expert system based on CBR (Case-Based Reasoning), legal statute rules are interpreted on the basis of precedents. This interpretation, because of its vagueness and uncertainty of the interpretation cannot be handled with the means used for crisp cases. In our legal expert system, on the basis of the facts of precedents, the statute rule is interpreted as a form of case rule, the application of which involves the concepts of membership and vagueness. The case rule is stored in a data base by means of fuzzy frames. The inference based on a case rule is made by fuzzy YES and fuzzy NO, and the degree of similarity of cases. The system proposed here will be used for legal education; its main area of application is contract, especially in relation to the United Nations Convention on Contracts for the International Sale of Goods (CISG).

This volume contains a selection of papers presented at the special workshop "Truth and Objectivity in Law and Morals," held at the 26th World Congress of the IVR. The papers deal with diverse but correlated issues such as the search for truth in and through legal argumentation; the intelligible character of rules inside theories of interpretation which guarantee the coherence and the integrity of law; the role of hermeneutic analysis in the construction of the objectivity of law; the procedural and contextual aspects of objectivity in legal reasoning; the role of objectivity in the distinction between the context of justification and the context of discovery; the problem about truth of normative propositions and legal statements; the incompatibility of non factualism with the traditional account of validity and legality; as well as the possibility of objectivity in morals.