6. The method as recited by claim 3 , wherein the determining of the subsets of the documents further comprises: creating a reverse-in-time graph based on the forward-in-time graph.
6. The method as recited by claim 3 , wherein the determining of the subsets of the documents further comprises: creating a reverse-in-time graph based on the forward-in-time graph. 7. The method as recited by claim 6 , wherein the determining of the subsets of the documents further comprises: creating an initial matrix of probabilities based on the reverse-in-time graph; multiplying the initial matrix of probabilities by itself, to create a plurality of matrixes wherein each matrix is considered a generation, until a matrix of probabilities is achieved, wherein the values from the matrix of probabilities is similar to the values from the previous generation matrix; and determining the subset from the matrix of probabilities.