Given a connected eulerian graph, we consider the question-related to the factorisation of regular graphs of even degree-under what conditions the distance of two edges e, e in an eulerian walk (i.e., the number of edges intervening between e and e ) always is of the same parity. A characterisation
On ?-equivalence and ?-equivalence of graphs
β Scribed by Du, Qingyan
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 336 KB
- Volume
- 21
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
β¦ Synopsis
W e define a partial ordering on the set of a-polynomials as well as a vertex splitting operation on the set of graphs, and introduce the notions of (r-equivalence and (r- uniqueness of graphs. Let a ( G ) be the a-polynomial of a graph G and a ( G ) = (r(GC).
Let H = (G, u , A, 5) be a vertex splitting graph of G. We prove that a ( G ) 5 F(H) and the equality holds if and only if every vertex of A is adjacent to every vertex of 5. This gives us an effective means to find v-equivalent and ,y-equivalent graphs. A necessary and sufficient condition for a graph to be X-unique but not (r-unique is also obtained.
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