23. The method of claim 22 , wherein the relative arrangements of the set of subtokens are represented by a tree of nodes, wherein the parent nodes in the tree of nodes represent general patterns of anchor subtokens separated by one or more other subtokens of the set of subtokens, and child nodes of these the parent nodes represent increasingly specific patterns of anchor subtokens.
23. The method of claim 22 , wherein the relative arrangements of the set of subtokens are represented by a tree of nodes, wherein the parent nodes in the tree of nodes represent general patterns of anchor subtokens separated by one or more other subtokens of the set of subtokens, and child nodes of these the parent nodes represent increasingly specific patterns of anchor subtokens. 25. The method of claim 23 , wherein anchor subtokens are selected based on heuristics including a relative location within the one or more subtokens at a given node and a frequency with which an anchor subtoken appears among one or more sibling nodes of the tree.