On obligations and normative ability: Towards a logical analysis of the social contract

✍ Scribed by Michael Wooldridge; Wiebe van der Hoek

• Publisher: Elsevier Science
• Year: 2005
• Tongue: English
• Weight: 385 KB
• Volume: 3
• Category: Article
• ISSN: 1570-8683
• DOI: 10.1016/j.jal.2005.04.006

✦ Synopsis

We develop a logic of normative ability, as an extension to the Alternating-time Temporal Logic (ATL) of Alur, Henzinger, and Kupferman. While conventional ATL contains cooperation modalities of the form C ϕ, intended to express the fact that coalition C have the capability to bring about ϕ, in Normative ATL* (NATL*), these expressions are replaced with constructs of the form η : C ϕ, with the intended interpretation that C have the ability to achieve ϕ within the context of the normative system η. A normative system is a set of constraints on the actions that may be performed in any give state. We show how these normative ability constructs can be used to define obligations and permissions: ϕ is said to be obligatory within the context of the normative system η if ϕ is a necessary consequence of every agent in the system behaving according to the conventions of η. After introducing NATL*, we investigate some of its axiomatic properties. To demonstrate its value as a logic for reasoning about multi-agent systems, we show how NATL* can be used to formalise a version of the social contract.