1, INTRODUCTION Intensional contexts, typical examples of which are complements of attitude report verbs such as believe and know have long received a special attention and almost been benchmark phenomena for natural language(NL) semantic theories since their peculiarities pose problems for any existing semantic theory (especially serious problems for those based upon logical systems such as Mo...

We consider the common-knowledge paradox raised by Halpem and Moses: common knowledge is necessary for agreement and coordination, but common knowledge is unattainable in the real world because of temporal imprecision. We discuss two solutions to this paradox: ( 1) modeling the world with a coarser granularity, and (2) relaxing the requirements for coordination. @ 1999 Elsevier Science B.V. All...

Conditions of information independence are important in information economics and game theory. We present notions of partial independence in Bayesian environments, and study their relationships to notions of common knowledge.

Only knowing captures the intuitive notion that the beliefs of an agent are precisely those that follow from its knowledge base. While only knowing has a simple possible-world semantics in a single agent setting, the many agent case has turned out to be much more challenging. In a recent paper, we proposed an account which arguably extends only knowing to multiple agents in a natural way. Howev...

When individual statistics are aggregated through a strictly monotone function to an aggregate statistic, common knowledge of the value of the aggregate statistic does not imply, in general, constancy of the individual statistics. This paper discusses two circumstances where it does occur. The rst case arises when partitions are independently drawn: in this case common knowledge of the value of...

We sometimes choose to do things only because other people are doing them. David Hume referred to the behavior chosen in such situations as conventions. A leading example of a convention for Hume and philosophers following him was language. Since everyone else uses the word "cat" to refer a cat and the word "dog" to refer to a dog, I also do so, but if everyone was using "cat" to refer to a dog...

Current dynamic epistemic logics often become cumbersome and opaque when common knowledge is added for groups of agents. Still, postconditions regarding common knowledge express the essence of what communication achieves. We present some methods that yield so-called reduction axioms for common knowledge. We investigate the expressive power of public announcement logic with relativized common kn...

This paper investigates the relationships between three different views of common knowledge: the iterate approach, the fixed point approach, and the shared environment approach. We show that no two of these approaches are equivalent, contrary to accepted wisdom. We argue that the fixed point is the best conceptual analysis of the pretheoretic notion, but that the shared environment approach has...