One pebble does not suffice to search plane labyrinths

  • Frank Hoffmann
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 117)


In 1975 L. Budach proved in a groundbreaking paper ([7]) that there is no finite automaton which is able to search (to master) all finite (cofinite) plane labyrinths. On the other side we have a result of M. Blum, D. Kozen (1978, [4]) saying that the search can be implemented with just two pebbles. The aim of our paper is to show that one pebble does not suffice, answering a question of Blum,Kozen. Furthermore we present a new construction for universal traps (see H.Antelmann, L.Budach, H.-A.Rollik 1979, [2]).


Finite Automaton Maximal Curvature Finite Deterministic Automaton Search Plane Infinite Path 
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 1981

Authors and Affiliations

  • Frank Hoffmann
    • 1
  1. 1.Institut f. Mathematik der Akademie der Wissenschaften der DDRBerlinG.D.R.

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