Contextual Permission: A Solution to the Free Choice Paradox

In this paper, we give a solution to the Free Choice Paradox. This is done in two stages. First, we have a close look at the logical interpretation of the natural language statements that lead to the paradox. This leads to making the important distinction of permitting an action in isolation or permitting it in combination with some or any other action, i.e. in a certain context. This distinction is made formal by the introduction of a new operator on actions, which forces them to be performed in isolation. With this distinction made clear it is possible to give a "new", stronger definition for the permission operator, which solves the Free Choice Paradox and which does not lead to any new inconsistencies or paradoxes

Open agent systems???

E-institutions are envisioned as facilities on the Internet for heterogeneous software agents to perform their interactions and thus forming truly open agent systems. We investigate how these heterogeneous agents can determine whether an institution is one in which they can participate. We propose a layered approach which is supported through a (traditional) middle agent that is part of the environment. Starting with a basic compatibility of message types, each extra layer ensures a higher degree of compatibility, but requires also extra sophistication in both the information required and the matching algorithms. In this paper, we describe reasoning about how an agent should take on a specific role, message matching, and protocol compatibility. We explore the issues in the context of an actual accommodation agent built in JACK, and a travel agency institution built in ISLANDER

Characterising Deadlines in Temporal Modal Defeasible Logic

We provide a conceptual analysis of several kinds of deadlines, represented in Temporal Modal Defeasible Logic. The paper presents a typology of deadlines, based on the following parameters: deontic operator, maintenance or achievement, presence or absence of sanctions, and persistence after the deadline. The deadline types are illustrated by a set of examples