Polynomial-Time Identification of an Extension of Very Simple Grammars from Positive Data

  • Ryo Yoshinaka
Part of the Lecture Notes in Computer Science book series (LNCS, volume 4201)


The class of very simple grammars is known to be polynomial-time identifiable in the limit from positive data. This paper introduces an extension of very simple grammars called right-unique simple grammars, and presents an algorithm that identifies right-unique simple grammars in the limit from positive data. The learning algorithm possesses the following three properties. It computes a conjecture in polynomial time in the size of the input data if we regard the cardinality of the alphabet as a constant. It always outputs a grammar which is consistent with the input data. It never changes the conjecture unless the newly provided example contradicts the previous conjecture. The algorithm has a sub-algorithm that solves the inclusion problem for a superclass of right-unique simple grammars, which is also presented in this paper.


Polynomial Time Regular Language Positive Data Inclusion Problem Simple Language 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2006

Authors and Affiliations

  • Ryo Yoshinaka
    • 1
  1. 1.National Institute of InformaticsUniversity of Tokyo 

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