The Logic of Time in Law and Legal Expert Systems*

Abstract. Research on an expert system regarding unemployment insurance law has pointed to the difficulties of explicitly representing temporal relations. The question has been addressed in the artificial intelligence literature with respect to planning systems and linguistic analysis. The approaches adopted do not appear to be directly transposable to legal discourse. The problem seems so far to have escaped notice amongst researchers attempting to develop legal expert systems. The paper explores in a preliminary way how lawyers use temporal concepts. It is submitted that “legal time” only partly overlaps with real time. A sketch of a formalization of temporal relations in law, following J. F. Allen's approach, is presented.