Algorithm 2: Updating-Token

Input: A token and its readings sorted in descending order

Output: An updated token

1) for i=1 to the number of the readings in the token

2)   scan the readings in order

3)   if (the local reading > the i-th reading in the token)

4)    insert the local reading before the i-th reading

5)    break

6)   end if

7) end for

8) if the number of readings in the token beyond k

9)  delete the last reading in the token

10) end if