lower irredundance number

The (lower) irredundance number ir(G) of a graph G is the minimum size of a maximal irredundant set of vertices in G. The upper irredundance number is defined as the maximum size of an irredundant set of vertices in G (Burger et al. 1997, Mynhardt and Roux 2020). In other words, it is the size of a maximum irredundant set, which is the same as the maximum size of a maximal irredundant set since all maximum irredundant sets are also maximal.

irredundance polynomial | irredundant set | upper irredundance number