Unique Metro Domination of a Ladder

A dominating set D of a graph G which is also a resolving set of G is called a metro dominating set. A metro dominating set D of a graph G(V,E) is a unique metro dominating set (in short an UMD-set) if |N(v) \cap D| = 1 for each vertex v in V-D and the minimum cardinality of an UMD-set of G is the unique metro domination number of G. In this paper, we determine unique metro domination number of P_n\times P_2