## Abstract A graph __G__ = (__V__, __E__) is called weakly four‐connected if __G__ is 4‐edge‐connected and __G__ − __x__ is 2‐edge‐connected for all __x__ ∈ __V__. We give sufficient conditions for the existence of ‘splittable’ vertices of degree four in weakly four‐connected graphs. By using thes
Generating Internally Four-Connected Graphs
✍ Scribed by Thor Johnson; Robin Thomas
- Publisher
- Elsevier Science
- Year
- 2002
- Tongue
- English
- Weight
- 257 KB
- Volume
- 85
- Category
- Article
- ISSN
- 0095-8956
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✦ Synopsis
A graph is a minor of another if the first can be obtained from a subgraph of the second by contracting edges. A graph G is internally 4-connected if it is simple, 3-connected, has at least five vertices, and if for every partition (A, B) of the edgeset of G, either |A| [ 3 or |B| [ 3 or at least four vertices of G are incident with an edge in A and an edge in B. We prove that if H and G are internally 4-connected graphs such that they are not isomorphic, H is a minor of G, and they do not belong to a family of exceptional graphs, then there exists a graph HOE such that HOE is isomorphic to a minor of G and either HOE is obtained from H by splitting a vertex or HOE is an internally 4-connected graph obtained from H by means of one of four possible constructions. This is a first step toward a more comprehensive theorem along the same lines.
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