Compressed Word Problems in HNN-Extensions and Amalgamated Products

  • Niko Haubold
  • Markus Lohrey
Part of the Lecture Notes in Computer Science book series (LNCS, volume 5675)


It is shown that the compressed word problem for an HNN-extension 〈H, t |t − 1 a t = ϕ(a) (a ∈ A) 〉 with A finite is polynomial time Turing-reducible to the compressed word problem for the base group H. An analogous result for amalgamated free products is shown as well.


Polynomial Time Word Problem Free Product Combinatorial Group Theory Oracle Access 
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Copyright information

© Springer-Verlag Berlin Heidelberg 2009

Authors and Affiliations

  • Niko Haubold
    • 1
  • Markus Lohrey
    • 1
  1. 1.Institut für InformatikUniversität LeipzigGermany

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