10. The non-transitory computer-readable storage medium of claim 9 , wherein the substitution rule is determined to be generated in response to the number of times satisfying a frequency threshold.
9. The non-transitory computer-readable storage medium of claim 8 , wherein the one or more computers are further configured to perform operations comprising: determining whether to generate a substitution rule based on the number of times and the collective meaning of the phrase that includes the first term, the second term, and the third term; and generating and storing the substitution rule in response to determining that the substitution rule is to be generated.