Other Structures
It has been shown that the following are not in general reconstructible:
- Digraphs: Infinite families of non-reconstructible digraphs are known, including tournaments (Stockmeyer) and non-tournaments (Stockmeyer). A tournament is reconstructible if it is not strongly connected. A weaker version of the reconstruction conjecture has been conjectured for digraphs, see New digraph reconstruction conjecture.
- Hypergraphs (Kocay).
- Infinite graphs. Let T be a tree on an infinite number of vertices such that every vertex has infinite degree. The counterexample is T and 2T. The question of reconstructibility for locally finite infinite graphs is still open.
Read more about this topic: Reconstruction Conjecture
Famous quotes containing the word structures:
“If there are people who feel that God wants them to change the structures of society, that is something between them and their God. We must serve him in whatever way we are called. I am called to help the individual; to love each poor person. Not to deal with institutions. I am in no position to judge.”
—Mother Teresa (b. 1910)
“The philosopher believes that the value of his philosophy lies in its totality, in its structure: posterity discovers it in the stones with which he built and with which other structures are subsequently built that are frequently better—and so, in the fact that that structure can be demolished and yet still possess value as material.”
—Friedrich Nietzsche (1844–1900)