Parallel communicating grammar systems, or PC grammar systems for short, have been invented to model a certain type of cooperation: the so-called class room model. Here a group of experts, modelled by grammars, work together in order to produce a document, that is, an output word. These experts work on their own, but synchronously, and they are able to exchange information on request.

In the literature many different types and variants of PC grammar systems have been studied, and the notion of parallel communicating systems has also been carried over to various types of automata. For example, PC systems of finite-state acceptors and PC systems of pushdown automata have been studied. Here we continue the study of these systems, and we extend the notion of PC system to restarting automata. Our aim is to develop a better understanding of the interaction of the local computations of restarting automata and the communication that takes place between the various components of a PC system.

- Otto, F.:
- Asynchronous parallel communicating systems of pushdown automata

*Int. Journal of Foundations of Computer Science 26 (2015) 643-666.* - Vollweiler, M.and Otto, F.:
- Systems of parallel communicating restarting automata.

*RAIRO Informatique Théorique et Applications 48 (2014) 3-22.* - Otto, F.:
- On centralized parallel communicating grammar systems with context-sensitive components. International Journal of Foundations of Computer Science, 24 (2013) 453-471.
- Otto, F.:
- Asynchronous PC systems of pushdown automata, In Dediu, A.-H. and Martin-Vide, C. and Truthe, B.,editors, Language and Automata Theory and Applications, LATA 2013, Proc., Lecture Notes in Computer Science 7810, Springer, Berlin, (2013), pages 456--467.
- Vollweiler, M.:
- Systems of Parallel Communicating Restarting Automata

*Dissertation, Fachbereich Elektrotechnik/Informatik, Universität Kassel, (2013)*. - Vollweiler, M. and Otto, F.:
- Systems of parallel communicating restarting automata.

In Freund, R., Holzer, M., Truthe, B. and Ultes-Nitsche, U., editors,*Fourth Workshop on Non-Classical Models for Automata and Applications (NCMA 2012), Proc.,*books@ocg.at, Band 290, pages 197-212, Österreichische Computer Gesellschaft, (2012). - Otto, F.:
- On Centralized PC grammar systems with context-sensitive components.

In Yen, H.-C. and Ibarra, O.H., editors,*DLT 2012, Proc.,*Lecture Notes in Computer Science 7410, pages 356-367, Springer, Berlin, (2012). - Otto, F.:
- Centralized PC systems of pushdown automata versus multi-head pushdown automata.

In Kutrib, M., Moreira, N. and Reis, R., editors,*DCFS 2012, Proc.,*Lecture Notes in Computer Science 7386, pages 244-251, Springer, Berlin, (2012).