英和和英

出典:『Wikipedia』 (2011/03/30 05:43 UTC 版)

英語による解説

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In graph theory, a mathematical discipline, a Halin graph is a planar graph constructed from a plane embedding of a tree with at least four vertices and with no vertices of degree 2, by connecting all the leaves of the tree (the vertices of degree 1) with a cycle that passes around the tree in the natural cyclic order defined by the embedding of the tree. Halin graphs are named after German mathematician Rudolf Halin, who defined them in 1964; they are sometimes also called roofless polyhedra.