23. The computer-readable medium of claim 22 , wherein the token similarity score for each matched token pair is zero for a matched token pair if a first token and a second token of the token pair are of different types.
23. The computer-readable medium of claim 22 , wherein the token similarity score for each matched token pair is zero for a matched token pair if a first token and a second token of the token pair are of different types. 26. The computer-readable medium of claim 23 , wherein the token similarity score for each matched token pair is determined by determining whether the length of a token of the matched token pair is less than a threshold length and, if so, setting the similarity score for the matched token pair to zero if the tokens are not an exact match.