Remark 2.3 It is often convenient to work with equivalence relations rather than partitions. In this case, an epistemic model based on \(S\) and \(\Agt\) can also be defined as a triple \(\langle W,\{\sim_i\}_{i\in\Agt},\sigma \rangle\) where \(W\) and \(\sigma\) are as above and for each \(i\in\Agt\), \(\sim_i\subseteq W\times W\) is reflexive, transitive and symmetric. Given such a model \(\langle W, \{\sim_i\}_{i\in\Agt},\sigma\rangle\), we write 