13. The method of 11 , wherein selecting the second hashes according to an increasing order of the third ordinal positions and the sub-phrase scores comprises selecting proper subsets of the set of second hashes according to the third ordinal positions of the content terms, each of the selected proper subsets having a common sub-phrase score.
13. The method of 11 , wherein selecting the second hashes according to an increasing order of the third ordinal positions and the sub-phrase scores comprises selecting proper subsets of the set of second hashes according to the third ordinal positions of the content terms, each of the selected proper subsets having a common sub-phrase score. 14. The method of claim 13 , wherein the proper subsets of the second hashes include only proper subsets having a cardinality of two or less.