Generalized one-unambiguity

Pascal Caron, Yo Sub Han, Ludovic Mignot

Research output: Chapter in Book/Report/Conference proceedingConference contribution

10 Citations (Scopus)


Brüggemann-Klein and Wood have introduced a new family of regular languages, the one-unambiguous regular languages, a very important notion in XML DTDs. A regular language L is one-unambiguous if and only if there exists a regular expression E over the operators of sum, catenation and Kleene star such that L(E)∈=∈L and the position automaton of E is deterministic. It implies that for a one-unambiguous expression, there exists an equivalent linear-size deterministic recognizer. In this paper, we extend the notion of one-unambiguity to weak one-unambiguity over regular expressions using the complement operator ¬. We show that a DFA with at most (n∈+∈2) states can be computed from a weakly one-unambiguous expression and that it is decidable whether or not a given DFA recognizes a weakly one-unambiguous language.

Original languageEnglish
Title of host publicationDevelopments in Language Theory - 15th International Conference, DLT 2011, Proceedings
Number of pages12
Publication statusPublished - 2011
Event15th International Conference on Developments in Language Theory, DLT 2011 - Milan, Italy
Duration: 2011 Jul 192011 Jul 22

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume6795 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Other15th International Conference on Developments in Language Theory, DLT 2011

All Science Journal Classification (ASJC) codes

  • Theoretical Computer Science
  • Computer Science(all)

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