 Both Abe and Bob receive and accept the information that \(p\) is wrong, and they both revise their belief states to include the new belief that \(\neg p\). After that, Abe has the basic beliefs \(\neg p\) and \(q\), whereas Bob has the basic beliefs \(\neg p\) and \(p \leftrightarrow q\). Now, their belief sets are no longer the same. Abe believes that \(q\) whereas Bob believes that \(\neg q\).