In this paper, we introduce a notion of epistemic equivalence between hierarchies of conditional beliefs and hierarchies of lexicographic beliefs, thus extending the standard equivalence results of Halpern (2010) and Brandenburger et al. (2007) to an interactive setting, and we show that there is a Borel surjective function, mapping each conditional belief hierarchy to its epistemically equival...

Lexicography has much to contribute to the information and knowledge society. The very essence of lexicography is its capacity to provide quick and easy access to data from which information needed by different types of users in different types of social situations can be retrieved. In this respect, the article discusses the concepts of information and knowledge related to lexicographic theory....