We give a proof of Guenin's theorem characterizing weakly bipartite graphs by not having an odd-K 5 minor. The proof curtails the technical and case-checking parts of Guenin's original proof.
A proof of McKee's eulerian-bipartite characterization
β Scribed by D.R. Woodall
- Publisher
- Elsevier Science
- Year
- 1990
- Tongue
- English
- Weight
- 248 KB
- Volume
- 84
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
β¦ Synopsis
A proof is given of the result about binary matroids that implies that a connected graph is Eulerian if and only if every edge lies in an odd number of circuits, and a graph is bipartite if and only if every edge lies in an odd number of cocircuits (minimal cutsets). A proof is also given of the result that the edge set of every graph can be expressed as a disjoint union of circuits and cocircuits. No matroid theory is assumed.
π SIMILAR VOLUMES
It was conjectured in [Wang, to appear in The Australasian Journal of Combinatorics] that, for each integer k β₯ 2, there exists . This conjecture is also verified for k = 2, 3 in [Wang, to appear; Wang, manuscript]. In this article, we prove this conjecture to be true if n β₯ 3k, i.e., M (k) β€ 3k. W
## Abstract This note gives a simple proof of a formula due to BollobΓ‘s, Frank and KaroΕski for counting acyclic bipartit tournaments. Β© 1995 John Wiley & Sons, Inc.
A signed graph is said to be weakly bipartite if the clutter of its odd circuits is ideal.
## Abstract In this paper we present a relatively simple proof of Tutt's characterization of graphic matroids. The proof uses the notion of βsigned graphβ and it is βgraphicβ in the sense that it can be presented almost entirely by drawing (signed) graphs. Β© 1995 John Wiley & Sons, Inc.