Characterizing languages by normalization and termination in string rewriting

Jeroen Ketema, Jakob Grue Simonsen

Abstract

We characterize sets of strings using two central properties from rewriting: normalization and termination. We recall the well-known result that any recursively enumerable set of strings can occur as the set of normalizing strings over a "small" alphabet if the rewriting system is allowed access to a "larger" alphabet (and extend the result to termination). We then show that these results do not hold when alphabet extension is disallowed. Finally, we prove that for every reasonably well-behaved deterministic time complexity class, there is a set of strings complete for the class that also occurs as the set of normalizing or terminating strings, without alphabet extension.

Original languageEnglish
Title of host publicationDevelopments in Language Theory : 16th International Conference, DLT 2012, Taipei, Taiwan, August 14-17, 2012. Proceedings
EditorsHsu-Chun Yen, Oscar H. Ibarra
Number of pages6
PublisherSpringer
Publication date2012
Pages459-464
ISBN (Print)978-3-642-31652-4
ISBN (Electronic)978-3-642-31653-1
DOIs
Publication statusPublished - 2012
Event16th International Conference on Developments in Language Theory - Taipei, Taiwan, Province of China
Duration: 14 Aug 201217 Aug 2012
Conference number: 16

Conference

Conference16th International Conference on Developments in Language Theory
Number16
Country/TerritoryTaiwan, Province of China
CityTaipei
Period14/08/201217/08/2012
SeriesLecture notes in computer science
Volume7410
ISSN0302-9743

Cite this