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Covering contractible edges in 3-connected graphs. I: Covers of size three are cutsets

✍ Scribed by Akira Saito


Publisher
John Wiley and Sons
Year
1990
Tongue
English
Weight
397 KB
Volume
14
Category
Article
ISSN
0364-9024

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✦ Synopsis


Abstract

An edge of a 3‐connected graph is said to be contractible if its contraction results in a 3‐connected graph. In this paper, a covering of contractible edges is studied. We give an alternative proof to the result of Ota and Saito (Scientia (A) 2 (1988) 101–105) that the set of contractible edges in a 3‐connected graph cannot be covered by two vertices, and extended this result to a three‐vertex covering. We also study the existence of a contractible edge whose contraction preserves a specified cycle, and show that a non‐hamiltonian 3‐connected graph has a contractible edge whose contraction preserves the circumference.


📜 SIMILAR VOLUMES


Covering contractible edges in 3-connect
✍ Robert L. Hemminger; Xingxing Yu 📂 Article 📅 1993 🏛 John Wiley and Sons 🌐 English ⚖ 272 KB 👁 1 views

## Abstract It is shown that if __G__ is a 3‐connected graph with |__V(G)__| ≥ 10, then, with the exception of one infinite class based on __K__~3,__p__~, it takes at least four vertices to cover the set of contractible edges of __G__. © 1993 John Wiley & Sons, Inc.

3-connected graphs with non-cut contract
✍ Xingxing Yu 📂 Article 📅 1994 🏛 John Wiley and Sons 🌐 English ⚖ 493 KB 👁 1 views

## Abstract In this paper, we show that if a 3‐connected graph __G__ other than __K__~4~ has a vertex subset __K__ that covers the set of contractible edges of __G__ and if |__K__| 3 and |__V(G)__| 3|__K__| − 1, then __K__ is a cutset of __G__. We also give examples to show that this result is best