E-unification by means of tree tuple synchronized grammars

  • Sébastien Limet
  • Pierre Réty
II CAAP CAAP-7: Unification and Matching
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1214)


The goal of this paper is both to give a E-unification procedure that always terminates, and to decide unifiability. For this, we assume that the equational theory is specified by a confluent and constructor-based rewrite system, and that four additional restrictions are satisfied. We give a procedure that represents the (possibly infinite) set of solutions thanks to a new kind of grammar, called tree tuple synchronized grammar, and that can decide unifiability thanks to an emptiness test. Moreover we show that if only three of the four additional restrictions are satisfied then unifiability is undecidable.


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Copyright information

© Springer-Verlag Berlin Heidelberg 1997

Authors and Affiliations

  • Sébastien Limet
    • 1
  • Pierre Réty
    • 1
  1. 1.LIFOUniversité d'OrléansOrléans cedex 2France

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