  We provide a fine classification of bisimilarities between states of possibly
different labelled Markov processes (LMP). We show that a bisimilarity relation
proposed by Panangaden that uses direct sums coincides with "event
bisimilarity" from his joint work with Danos, Desharnais, and Laviolette. We
also extend Giorgio Bacci's notions of bisimilarity between two different
processes to the case of nondeterministic LMP and generalize the game
characterization of state bisimilarity by Clerc et al. for the latter.
