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In knot theory, a branch of topology, a Brunnian link is a nontrivial link that becomes a set of trivial unlinked circles if any one component is removed. In other words, cutting any loop frees all the other loops (so that no two loops can be directly linked). The name ''Brunnian'' is after Hermann Brunn. Brunn's 1892 article ''Über Verkettung'' included examples of such links. == Examples == The best-known and simplest possible Brunnian link is the Borromean rings, a link of three unknots. However for every number three or above, there are an infinite number of links with the Brunnian property containing that number of loops. Here are some relatively simple three-component Brunnian links which are not the same as the Borromean rings: Image:Brunnian-3-not-Borromean.svg|12-crossing link. Image:Three-triang-18crossings-Brunnian.svg|18-crossing link. Image:Three-interlaced-squares-Brunnian-24crossings.svg|24-crossing link. The simplest Brunnian link other than the 6-crossing Borromean rings is presumably the 10-crossing L10a140 link.〔Bar-Natan, Dror (2010-08-16). "(All Brunnians, Maybe )", ''(Pensieve )''.〕 An example of a ''n''-component Brunnian link is given by the ("Rubberband" Brunnian Links ), where each component is looped around the next as ''aba''−1''b''−1, with the last looping around the first, forming a circle. 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「Brunnian link」の詳細全文を読む スポンサード リンク
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