Synchronization Languages and Rewriting Systems
Résumé
We extend the rewriting system defined by L. Guo, K. Salomaa and S. Yu in order to characterize closure properties of synchronization languages. The extension is shown to have well-known properties of commutation systems and to be the rewriting system which suits the synchronization languages best. We give a characterization of finite synchronization languages in terms of languages closed under the extension.