Parallel Communicating Grammar Systems:

 Recent Results, Open Problems

  Gheorghe PAUN

Abstract:

  First, we recall several recent results concerning the generative power of parallel communicating (PC) grammar systems, including characterizations of recursively enumerable (RE) languages starting from PC grammar systems and their languages. Then, we prove that the simple matrix languages can be generated by PC grammar systems and finally we introduce a new class of PC grammar systems: when a component has to communicate, it may transmit any non-empty prefix of its current sentential form. Each RE language is the morphic image of the intersection with a regular language of a language generated by such a system. A series of open problems are pointed out in this context.

 Gyenizse Pal 1997. Május 21. Szerda 13:01:59 MET DST