Reconstruction conjecture says that graphs (with at least three vertices) are determined uniquely by their vertex deleted subgraphs. This conjecture is five decades old.

Searching relevant literature, I found that the following classes of graphs are known to be reconstructible :

  • trees
  • disconnected graphs, graphs whose complement is disconnected
  • regular graphs
  • Maximal Outerplanar Graphs
  • maximal planar graphs
  • outerplanar graphs
  • Critical blocks
  • Separable graphs without end vertices
  • unicyclic graphs (graphs with one cycle)
  • non-trivial cartesian product graphs
  • squares of trees
  • bidegreed graphs
  • unit interval graphs
  • threshold graphs
  • nearly acyclic graphs (i.e., G-v is acyclic)
  • cacti graphs
  • graphs for which one of the vertex deleted graph is a forest.

I recently proved that a special case of partial 2-trees are reconstructible. I am wondering if partial 2-trees (a.k.a series-parallel graphs) are known to be reconstructible. Partial 2-trees do not seem to fall into any of the above mentioned categories.

  • Am I missing any other known classes of reconstructible graphs in the above list ?
  • In particular, are partial 2-trees known to be reconstructible ?
  • 2
    $\begingroup$ I don't have access to it, but this paper: springerlink.com/content/p6r03877310411wr claims that N-free ordered sets are reconstructible. $\endgroup$
    – mhum
    Feb 27, 2011 at 23:37
  • 2
    $\begingroup$ To further elaborate on @mhum's comment: series-parallel partial orders are precisely those that are N-free, so the paper is claiming that series-parallel posets are reconstructible. The transitive reductions of series-parallel posets are the series-parallel graphs, but I'm not sure how the reconstruction conjecture interacts with the transitive edges. $\endgroup$ Feb 28, 2011 at 9:15
  • $\begingroup$ For your list: Kiyomi, Saitoh, and Uehara showed that Bipartite Permutation Graphs Are Reconstructible. $\endgroup$ Mar 2, 2011 at 3:41
  • $\begingroup$ One more for your list: some planar graphs are reconstructible. $\endgroup$
    – virgi
    Mar 13, 2011 at 21:14
  • 2
    $\begingroup$ Shiva, Did you get any new result? $\endgroup$
    – Saeed
    Feb 21, 2012 at 11:53

1 Answer 1


I believe that it has not been shown that bidegreed graphs are reconstructible. Bidegreed graphs are edge-reconstructible. Kocay did some work on reconstruction of bidegreed graphs, but did not reach a comprehensive result that I have been able to find. The notion that it has been proven that bidegreed graphs are reconstructible seems to be a bit of misinformation circulating on the web.


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