 In graph algorithms, therefore, it may sometimes be useful to construct the reversal of a graph, in order to put the graph into a form which is more suitable for the operations being performed on it.An example of this is Kosaraju's algorithm for strongly connected components, which applies depth first search twice, once to the given graph and a second time to its reversal.A skew-symmetric graph is a graph that is isomorphic to its own transpose graph, via a special kind of isomorphism that pairs up all of the vertices.