The Reversible Temporal Process Language

Reversible debuggers help programmers to quickly find the causes of misbehaviours in concurrent programs. These debuggers can be founded on the well-studied theory of causal-consistent reversibility, which allows one to undo any action provided that its consequences are undone beforehand. Till now, causal-consistent reversibility never considered time, a key aspect in real world applications. Here, we study the interplay between reversibility and time in concurrent systems via a process algebra. The Temporal Process Language (TPL) by Hennessy and Regan is a well-understood extension of CCS with discrete-time and a timeout operator. We define revTPL, a reversible extension of TPL, and we show that it satisfies the properties expected from a causal-consistent reversible calculus. We show that, alternatively, revTPL can be interpreted as an extension of reversible CCS with time.