As noted above, a crucial feature of these informational attitudes is that they may be defeated by appropriate evidence. In fact, we can characterize these attitudes in terms of the type of evidence which can prompt the agent to adjust her beliefs. To make this precise, we introduce the notion of a conditional belief: suppose \(\M=\plausmodel\) is an epistemic-plausibility model and \(E\) and \(F\) are events, then the conditional belief operator is defined as follows: