翻訳と辞書 |
Paving matroid : ウィキペディア英語版 | Paving matroid
In the mathematical theory of matroids, a paving matroid is a matroid in which every circuit has size at least as large as the matroid's rank. In a matroid of rank every circuit has size at most , so it is equivalent to define paving matroids as the matroids in which the size of every circuit belongs to the set .〔.〕 It has been conjectured that almost all matroids are paving matroids. ==Examples== Every simple matroid of rank three is a paving matroid; for instance this is true of the Fano matroid. The Vámos matroid provides another example, of rank four. Uniform matroids of rank have the property that every circuit is of length exactly and hence are all paving matroids; the converse does not hold, for example, the cycle matroid of the complete graph is paving but not uniform. A Steiner system is a pair where is a finite set of size and is a family of -element subsets of with the property that every -element subset of is also a subset of exactly one set in . The elements of form a -partition of and hence are the hyperplanes of a paving matroid on .
抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Paving matroid」の詳細全文を読む
スポンサード リンク
翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|