To formalize notions like "centrality" (how central is a node in the hyperdocument), we wish to take the sum of the distances from a node to all other nodes. However, in the matrix of the example the sum would always be infinite. To get meaningful sums we replace infinity by a reasonably large number K, which we call the conversion constant. The result is a converted distance matrix. The higher K the more important the fact becomes that a node is not reachable from another node. For identifying hierarchies a large K improves the choice of a "good" root node, while for calculating metrics the influence of K should be reduced, so a smaller K is better. A generally usable choice of K is the number of nodes. Any finite distance is always smaller than the number of nodes in a hyperdocument.