Actors, Actions, and Initiative in Normative System Specification

摘要

The logic of norms, called deonitic logic, has been used to specify normativeconstraints for information systems. Intuitively, deonitic logic presupposes the concept of an actor who undertakes actions and is responsible for fulfilling obligations. However, the concept of an actor has not been formalized until now. The authors present a formalization in dynamic logic, which allows us to express the actor who initiates actions or choices. This is then combined with a formalization, presented earlier, of deonitic logic in dynamic logic, which allows one to specify obligations, permissions, and prohibitions to perform an action. The addition of actors allows one to express who has the responsibility to perform an action. In addition to the application of the concept of an actor in deonitic logic, they discuss two other applications of actors. Towards the end of the paper, they discuss whether the concept of an actor can be combined with that of an object to formalize the concept of active objects.