Improving the previously known best bound, we show that any recursively enumerable language can be generated with a non-returning parallel communicating (PC) grammar system having six context-free components. We also present a non-returning universal PC grammar system generating unary languages, that is, a system where not only the number of components, but also the number of productions and the number of nonterminals are limited by certain constants, and these size parameters do not depend on the generated language.
|Number of pages||10|
|Journal||Electronic Proceedings in Theoretical Computer Science, EPTCS|
|Publication status||Published - Jul 30 2009|
|Event||11th International Workshop on Descriptional Complexity of Formal Systems, DCFS 2009 - Magdeburg, Germany|
Duration: Jul 6 2009 → Jul 9 2009
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