This working paper contains the slides of two invited lectures on the Epistemic Foundations of Game Theory, delivered at the Royal Netherlands Academy of Arts and Sciences (KNAW) on February 8, 2007.

In [G. Bonanno, Rational choice and AGM belief revision, Artificial Intelligence, 2009] a semantics for one-stage AGM belief revision was proposed based on choice frames, borrowed from the rational choice literature. In this paper we extend the semantics of choice frames to deal with iterated...

Aumann (1976) put forward a formal definition of common knowledge and used it to prove that two ""like minded"" individuals cannot ""agree to disagree"" in the following sense. If they start from a common prior and update the probability of an event E (using Bayes'' rule) on the basis of private...

We propose a modal logic based on three operators, representing intial beliefs, information and revised beliefs. Three simple axioms are used to provide a sound and complete axiomatization of the qualitative part of Bayes’ rule. Some theorems of this logic are derived concerning the...

Within an incomplete information framework (where the primitives are the individuals'' belief hierarchies) we investigate the intersubjective implications of the assumption that it is common belief that no individual has any false beliefs (a key component of the Truth Axiom). We consider two...

We study belief change branching-time structures. First, we identify a property of branching-time frames that is equivalent to AGM-consistency, which is defined as follows. A frame is AGM-consistent if the partial belief revision function associated with an arbitrary state-instant pair and an...

The interaction bietween knowledge and belief in a temporal context is analyzed. An axiomatic formulation and semantic characterization of the principle of belief persistency implied by the standard conditionalization rule are provided. This principle says that an individual does not change her...

We consider interactive epistemic models where individuals are described by both their ""knowledge"" and their ""beliefs."" Three intersubjective consistency conditions are examined: Intersubjective Caution (if an individual believes something to be common belief then he knows it to be common...

We provide an introduction to interactive belief systems from a qualitative and semantic point of view. Properties of belief hierarchies are formulated locally. Among the properties considered are ""Common belief in no error"" (which has been shown to have important game theoretic applications),...

The temporal updating of an agent’s beliefs in response to a flow of information is modeled in a simple modal logic that, for every date t , contains a normal belief operator B_t and a non-normal information operator I_t which is analogous to the ‘only knowing’ operator discussed in the...