We provide a new characterization of both belief update and belief revision in terms of a Kripke-Lewis semantics. We … (2) have A as antecedent. We show that this class of models characterizes both the Katsuno-Mendelzon (KM) belief update … that can be completed into a full KM/AGM update/revision function, and (2) for every KM/AGM update/revision function there …