Using Programming Concepts in Deontic Reasoning

摘要

The paper examines variants of logics based on the concepts of weakest preconditions and strongest postconditions as bases for deontic reasoning. First, a basic system, called PD(e)L, is given, based on (propositional) dynamic logic. Next, a system enriched with an extra DONE predicate, expressing that an action has just been performed, is discussed, which is complete for deontic propositions involving uninterpreted actions of a certain restricted class. Furthermore, it discusses a system for the case of interpreted (unrestricted) actions where it is possible to express the DONE predicate in terms of strongest postconditions, provided certain conditions are satisfied concerning the behavior of actions.