Graphs with equal secure total domination and inverse secure total domination numbers

A secure total dominating set of a graph G = (V, E) is a total dominating set D O V(G) with the property that for each u OE V(G) -D, there exists v OE D adjacent to u such that (D -{v}) is an element of {u} is a total dominating set. If V(G) -D contains a secure total dominating set D is an element of of G, then D is an element of is called an inverse secure total dominating set with respect to D. The secure and inverse secure total domination number of G is the minimum cardinality among all secure and inverse secure total dominating sets of G and is denoted by gst(G) and 1(), stG.respectively. In this paper, we find some graphs for which 1(G)(G). ststGG..-= Also we obtain some graphs for which gamma(st)(G) = gamma(-1)(st) (G) = p/2.