Well-quasi-ordered classes of groups
β Scribed by Roger M Bryant
- Publisher
- Elsevier Science
- Year
- 1976
- Tongue
- English
- Weight
- 883 KB
- Volume
- 43
- Category
- Article
- ISSN
- 0021-8693
No coin nor oath required. For personal study only.
π SIMILAR VOLUMES
A lattice-ordered abelian group is called ultrasimplicial iff every finite set of positive elements belongs to the monoid generated by some finite set of positive Z-independent elements. This property originates from Elliott's classification of AF C U -algebras. Using fans and their desingularizatio
## Abstract Let π΄ be a class of graphs and let βͺ― be the subgraph or the induced subgraph relation. We call βͺ― an __ideal__ (with respect to βͺ―) if βͺ― implies that βͺ―. In this paper, we study the ideals that are wellβquasiordered by βͺ―. The following are our main results. If βͺ― is the subgraph relation, w
## Abstract We study classes of finite, simple, undirected graphs that are (1) lower ideals (or hereditary) in the partial order of graphs by the induced subgraph relation β€~i~, and (2) wellβquasiβordered (WQO) by this relation. The main result shows that the class of cographs (__P~4~__βfree graphs
We study bipartite graphs partially ordered by the induced subgraph relation. Our goal is to distinguish classes of bipartite graphs that are or are not well-quasi-ordered (wqo) by this relation. Answering an open question from [J Graph Theory 16 (1992), 489-502], we prove that P 7 -free bipartite g