Identifying unrecognizable regular languages by queries

  • Claudio Ferretti
  • Giancarlo Mauri
Extended Abstracts
Part of the Lecture Notes in Computer Science book series (LNCS, volume 784)


We describe a new technique useful in identifying a subclass of regular trace languages (defined on a free partially commutative monoid). We extend an algorithm defined by Dana Angluin in 1987 for DFA's and using equivalence and membership queries. In trace languages the words are equivalence classes of strings, and we show how to extract, from a given class, a string that can drive the original learning algorithm. In this way we can identify a class of regular trace languages which includes languages which are not recognizable by any automaton.


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Copyright information

© Springer-Verlag Berlin Heidelberg 1994

Authors and Affiliations

  • Claudio Ferretti
    • 1
  • Giancarlo Mauri
    • 1
  1. 1.Dipartimento di Scienze del' InformazioneUniversità di MilanoMilanoItaly

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