Properties of real nodes are selected by which to organize the real nodes as leaf nodes in a tree graph. A number of virtual nodes are provided, each representing a value of a selected property for at least one of the real nodes. The virtual nodes and real nodes are organized into the tree graph, the...http://www.google.fr/patents/US7689570?utm_source=gb-gplus-shareBrevet US7689570 - Dynamic sorting of virtual nodes
