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ISSN 1088-6850(e) ISSN 0002-9947(p)

Growth and ergodicity of context-free languages II: The linear case

Author(s): Tullio Ceccherini-Silberstein
Journal: Trans. Amer. Math. Soc. 359 (2007), 605-618.
MSC (2000): Primary 68Q45; Secondary 05A16, 05C20, 68Q42
Posted: June 13, 2006
MathSciNet review: 2255188
Retrieve article in: PDF

Abstract | References | Similar articles | Additional information

Abstract: A language over a finite alphabet $\bf\Sigma$ is called growth-sensitive if forbidding any non-empty set of subwords yields a sub-language whose exponential growth rate is smaller than that of . Say that a context-free grammar (and associated language) is ergodic if its dependency di-graph is strongly connected. It is known that regular and unambiguous non-linear context-free languages which are ergodic are growth-sensitive. In this note it is shown that ergodic unambiguous linear languags are growth-sensitive, closing the gap that remained open.

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