20. The computer-readable medium of claim 12 , wherein the regular expression matching determines that a particular token of the input text corresponds to a plurality of attributes, further comprising: generating a second plurality of attribute determination sequences, wherein each attribute sequence determination of the second plurality of attribute determination sequences has a different attribute of the plurality of attributes for the particular token of the input text; identifying a subset of attribute determinations in each attribute determination sequence of the second plurality of attribute determination sequences that are likely to be a false positive.
12. The computer-readable medium of claim 11 , wherein identifying at least one attribute determination corresponding to an attribute token of the set of attribute tokens as a false positive comprises generating a skeleton token in which: each token within the input text is represented by a corresponding character; and the character that corresponds to a given token of the input text indicates which attribute, if any, the given token was determined to be.