Action abstraction in timed process algebra - The case for an untimed silent step

This paper discusses action abstraction in timed process algebras. It is observed that the leading approaches to action abstraction in timed process algebra all maintain the timing of actions, even if these actions are abstracted from. This paper presents a novel approach to action abstraction in timed process algebras. Characteristic for this approach is that in abstracting from an action, also its timing is abstracted from. We define an abstraction operator and a timed variant of rooted branching bisimilarity and establish that this notion is an equivalence relation and a congruence.