A Logspace Algorithm for Partial 2-Tree Canonization

  • Vikraman Arvind
  • Bireswar Das
  • Johannes Köbler
Part of the Lecture Notes in Computer Science book series (LNCS, volume 5010)


We show that partial 2-tree canonization, and hence isomorphism testing for partial 2-trees, is in deterministic logspace. Our algorithm involves two steps: (a) We exploit the “tree of cycles” property of biconnected partial 2-trees to canonize them in logspace. (b) We analyze Lindell’s tree canonization algorithm and show that canonizing general partial 2-trees is also in logspace, using the algorithm to canonize biconnected partial 2-trees.


Tree Representation Graph Isomorphism Oriented Edge Articulation Point Isomorphism Order 
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Copyright information

© Springer-Verlag Berlin Heidelberg 2008

Authors and Affiliations

  • Vikraman Arvind
    • 1
  • Bireswar Das
    • 1
  • Johannes Köbler
    • 2
  1. 1.The Institute of Mathematical SciencesChennaiIndia
  2. 2.Institut für InformatikHumboldt Universität zu BerlinGermany

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