On rigid circuit graphs
On rigid circuit graphs
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DOI：
10.1007/bf02992776
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发表时间：
1961-04
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影响因子：
--
通讯作者：
G. Dirac
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文献类型：
--
作者：
G. Dirac
本文考虑的图可能有圈（德语：Schlinge）和多重边，它们可能是无限的，除非有相反的说明。选择的公理是假定贯穿始终。定义1.如果/2是一个回路，x和y是/2的两个不同的顶点，它们没有属于/2的任何边连接，那么连接x和y的边称为/2的弦。如果一个图中的每一个顶点数超过三个的回路至少有一个弦，则称之为刚性回路图，或ri。Cir.简称graph。
The graphs considered in this paper may have loops (German: Schlinge) and multiple edges and they may be infinite, except where the contrary is stated. The axiom of choice is assumed throughout.Definitions 1. If/2 is a circuit and x and y are two distinct vertices of/2 which are not joined by any edge belonging to/2, then an edge which joins x and y is called a chord of/2. A graph in which every circuit with more than three vertices has at least one chord, is called a rigid circuit graph, or ri. cir. graph for short.