related to the current level 2 node if in step 52 there are no additional level 3 parent nodes to check with respect to the current level 2 node then control passes back to step 46 to proceed on to the next level 2 parent node if one exists if however there are remaining level 3 parent nodes to check with respect to the current level 2 node then control passes to step 54 in which the current level 3 parent node is flagged as checked this process of checking each node at each level for additional parent nodes at higher levels continues through steps 56 58 60 and 62 until all n levels of the call tree are traversed and thereby checked for related nodes at different levels of the tree structure table 32 of fig2 shows a typical node traversal path using the methodology described in fig3 the process begins at the focal node a from here the method traces a path up to node g which is a level 2 parent of node a from node g the method then continues the path up to node f which is a level 3 parent of node a node f has no level 4 parents and thus the method returns back to node g this node has no additional parents other than node f and therefore the method returns back to node a from here the method then traces another path from node a up to node c which is the second level 2 parent of node.