A Class of Edge Critical 4-Chromatic Graphs
نویسندگان
چکیده
We consider several constructions of edge critical 4-chromatic graphs which can be written as the union of a bipartite graph and a matching. In particular we construct such a graph G with each of the following properties: G can be contracted to a given critical 4-chromatic graph; for each n;,: 7, G has n vertices and three matching edges (it is also 8n ) shown that such graphs must have at least Sedges ; G has arbitrary large girth.
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ورودعنوان ژورنال:
- Graphs and Combinatorics
دوره 13 شماره
صفحات -
تاریخ انتشار 1997