Let be a simple graph, and let be a positive integer. A subset is a -\emph{dominating set} of the graph if every vertex is adjacent to at least vertices of . The -\emph{domination number} is the minimum cardinality among the -dominating sets of . Note that the -domination number is the usual \emph{domination number} .
Keywords: Domination; p-domination; Multiple domination; Cac- tus graph; Matching number