The process of decomposing a complex system into simpler subsystems has been
of interest to computer scientists over many decades, for instance, for the
field of distributed computing. In this paper, motivated by the desire to
distribute the process of active automata learning onto multiple subsystems, we
study the equivalence between a system and the total behaviour of its
decomposition which comprises subsystems with communication between them. We
show synchronously- and asynchronously-communicating decompositions that
maintain branching bisimilarity, and we prove that there is no decomposition
operator that maintains divergence-preserving branching bisimilarity over all
LTSs.Comment: In Proceedings EXPRESS/SOS 2019, arXiv:1908.0821