We describe a new operator for reversible process calculi that allows us to model locally controlled reversibility. In our setting, actions can be undone spontaneously or as a part of pairs of so-called concerted actions, where performing forwards a weak action forces undo- ing of another action, without the need of a global control or a mem- ory. We model an example from chemistry, the simple interaction of two water molecules, and give an informal explanation of the role of the new operator.
['Stefan Kuhn', 'Irek Ulidowski']
Towards Modelling of Local Reversibility