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Counterexamples to two conjectures about distance sequences

✍ Scribed by Mark E. Watkins; James B. Shearer


Publisher
Elsevier Science
Year
1987
Tongue
English
Weight
558 KB
Volume
66
Category
Article
ISSN
0012-365X

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📜 SIMILAR VOLUMES


Counterexamples to two conjectures of Hi
✍ S. Fiorini 📂 Article 📅 1978 🏛 John Wiley and Sons 🌐 English ⚖ 122 KB

## Abstract Counterexamples are presented to the following two conjectures of Hilton: A graph which does not contain a spanning __K__~1t~ is Vl‐critical if and only if it is VC‐critical. If __G__ is a class‐two graph which contains a spanning Pl‐critical subgraph __H__ of the same chromatic index

Counterexamples to a conjecture about bo
✍ Eckhard Steffen 📂 Article 📅 1996 🏛 Elsevier Science 🌐 English ⚖ 47 KB

We follow the terminology and notion of . By a well known theorem of Vizing it follows that the chromatic index z'(G) of a cubic graph G is 3 or 4. If z'(G) = 4 we say that G is non-Tait-colourable. Holroyd and Loupekine [1] defined a bottleneck in a non-Tait-colourable cubic graph G =