Concrete Branching Bisimilarity for Processes with Time-outs

Abstract

This paper provides an adaptation of branching bisimilarity to reactive systems with time-outs that does not enable eliding of time-out transitions. Multiple equivalent definitions are procured, along with a modal characterisation and a proof of its congruence property for a standard process algebra with recursion. The last section presents a complete axiomatisation for guarded processes without infinite sequences of unobservable actions.

Whereas the bisimilarity of arXiv:2408.10117 elides timeouts, just like branching bisimilarity elides $\ddot{I}„$-transitions, the one of this paper instead treats time-outs more like visible actions. We obtained this paper from arXiv:2408.10117 by systemically suppressing this eliding feature, thereby obtaining simpler definitions and proofs. arXiv admin note: substantial text overlap with arXiv:2408.10117