Artificial Intelligence and Law

, Volume 18, Issue 3, pp 247–283

Norm-system revision: theory and application


DOI: 10.1007/s10506-010-9097-5

Cite this article as:
Stolpe, A. Artif Intell Law (2010) 18: 247. doi:10.1007/s10506-010-9097-5


This paper generalises classical revision theory of the AGM brand to sets of norms. This is achieved substituting input/output logic for classical logic and tracking the changes. Operations of derogation and amendment—analogues of contraction and revision—are defined and characterised, and the precise relationship between contraction and derogation, on the one hand, and derogation and amendment on the other, is established. It is argued that the notion of derogation, in particular, is a very important analytical tool, and that even core deontic concepts such as that of permission resists a satisfactory analysis without it. By way of illustration the last section of the paper analyses the much debated concept of positive permission, of which there turns out to be more than one kind.


DerogationAmendmentRevision theoryPermission

Copyright information

© Springer Science+Business Media B.V. 2010

Authors and Affiliations

  1. 1.Institute of InformaticsUniversity of OsloOsloNorway