Logics of Agency and Multi-Agent systems

Lecturers: Jan Broersen, Andreas Herzig and Nicolas Troquard
Type: Introductory Course
Section: Logic and Computation
Week: 2
Time: 9:00-10:30
Webpage: http://people.cs.uu.nl/broersen/ESSLLI07 (the present page is essentially a copy)



This course presents two families of logics that are closely related and that have been introduced and studied independently in different fields in order to reason about agency and time. Belnap's logic of `seeing to it that' (STIT) and Kanger and Pörn's `bringing it about' logic have been intensely studied and debated in philosophy of action. These logics provide an explanation of the causal relation between an agent and a state of affairs that the agent makes true. They have been extended by Horty with deontic concepts such as obligation and permission. Temporal logics of agency such as Pauly's Coalition Logic (CL) and Alur et al.'s Alternating-time Temporal Logic (ATL) have been proposed more recently in computer science for the specification and verification of multi-agent systems. These logics enable reasoning about what agents and groups of agents can achieve by means of actions from their repertoire. They have been extended by van der Hoek and Wooldridge with the notion of knowledge. The course aims at introducing these two families, and explicating the connections between them. We discuss the choices of the linguistic primitives, semantics, translations and computational properties. In addition, we consider a unifying framework incorporating the general aspects of STIT and ATL. We discuss extensions of the unifying framework that deal with interactions of agency with epistemic notions and deontic notions.


We assume basic background knowledge of normal modal logics, and some knowledge of semantics for weak modal logics, such as neighborhood semantics.


Lecture 1: Modal logic for multi-agent systems

Lecture 2: Logical frameworks for multi-agent systems: Cohen and Levesque

Lecture 3: The power of cooperation: coalition logic

Lecture 4: STIT theory of agency and applications

Lecture 5: Going fully strategic

Course reader