@article {107,
	title = {PC grammar systems with five context-free components generate all recursively enumerable languages},
	journal = {Theoretical Computer Science},
	volume = {299},
	year = {2003},
	pages = {785 - 794   },
	publisher = {Elsevier},
	address = {Amsterdam (The Netherlands)},
	abstract = {Parallel communicating grammar systems (PC grammar systems, in short) are language generating devices consisting of several context-free grammars which work synchronously on their own sentential forms and communicate the generated strings to each other by request. These systems with eleven components are known to have the power of the Turing machines. We considerably improve this result, proving that five components suffice in order to generate any recursively enumerable language. 


},
	keywords = {descriptional complexity, parallel communicating grammar systems, recursively enumerable languages},
	issn = {0304-3975 },
	doi = {10.1016/S0304-3975(02)00852-6 },
	author = {Erzsebet Csuhaj-Varj{\'u} and Gheorghe Paun and Gy{\"o}rgy Vaszil}
}
