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Rigid Reachability

  • Harald Ganzinger
  • Florent Jacquemard
  • Margus Veanes
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1538)

Abstract

We show that rigid reachability, the non-symmetric form of rigid E-unification, is undecidable already in the case of a single constraint. From this we infer the undecidability of a new rather restricted kind of second-order unification. We also show that certain decidable subclasses of the problem which are P-complete in the equational case become EXPTIME-complete when symmetry is absent. By applying automata-theoretic methods, simultaneous monadic rigid reachability with ground rules is shown to be in EXPTIME.

Keywords

Function Symbol Ground Rule Ground Term Tree Automaton Ground Instance 
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 1998

Authors and Affiliations

  • Harald Ganzinger
    • 1
  • Florent Jacquemard
    • 1
  • Margus Veanes
    • 1
  1. 1.Max-Planck-Institut für InformatikSaarbrückenGermany

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