Strategies for Belief Revision

This paper is a contribution to dynamic doxastic logic (DDL), that is, doxastic logic supplemented with operators for belief change due to new information. Thus in addition to operators for belief (B) and doxastic commitment (K) we also have, for each pure Boolean formula φ, a propositional operator [∗φ] with the informal reading “after the agent has come to believe that φ and revised his beliefs accordingly it is the case that”. The resulting new logical landscape turns out to be overwhelmingly rich. An important question—and the topic of this paper—is how to deal with this richness. Krister Segerberg Uppsala Universitet, Box 627, 751 26 Uppsala, Sweden e-mail: [email protected]