Suchergebnisse

Convexity numbers can be defined for graphs with the follow¬ ing definition of convexity : a subset S of the set of vertices V(G) of the graph G is said to be convex if for every vertices x and y in S, all the geodesies of G between x and y are in S. Among these numbers, we investigate especially the Radon number and after the description of some useful properties of graphs having a high Radon number as compared to their number of vertices, we classify those with n + 1, n, n — 1 and n — 2 as Radon number («is the cardinality of V(G)).