 Jeffrey Conditionalization  Suppose that \(\Pr(\cdot)\) is your subjective probability at time \(t\) and that between \(t\) and \(t^\prime\) your subjective probabilities in the partition \(\{A_i : 1\leq i \leq n \}\subseteq \mathbf{A}^{\Pr}\) (and no finer partition) change to \(p_{i} \in [0,1]\) with \(\sum_{i} p_{i} = 1\). Then, your subjective probability at time \(t^\prime\) should be \(\Pr^\prime(\cdot) = \sum_{i} \Pr(\cdot \mid A_{i}) p_{i}\). 