8. The method of claim 1 , wherein the tree structure, candidate tree and each alternate candidate tree each comprises: at least one node; and at least one leaf emanating from one node wherein a subtree of the candidate tree comprises a location within the candidate tree and all nodes and leaves emanating from the location.
8. The method of claim 1 , wherein the tree structure, candidate tree and each alternate candidate tree each comprises: at least one node; and at least one leaf emanating from one node wherein a subtree of the candidate tree comprises a location within the candidate tree and all nodes and leaves emanating from the location. 9. The method of claim 8 , wherein the modifying of the candidate tree comprises: removing a subtree of the candidate tree associated with one location; inserting a new node into the candidate tree at said location; associating one of a horizontal division and a vertical division with the new node; inserting a new leaf into the candidate tree emanating from the new node; associating the new leaf with the subsequent graphic assembly; and inserting the subtree into the candidate tree, said subtree emanating from the new node.