Graph operations that are good for greedoids Original Research Article

image is a local maximum stable set of a graph image, and we write image, if the set image is a maximum stable set of the subgraph induced by image, where image is the neighborhood of image. In Levit and Mandrescu (2002) we have proved that image is a greedoid for every forest image. The cases of bipartite graphs and triangle-free graphs were analyzed in Levit and Mandrescu (2003) and Levit and Mandrescu (2007) respectively.