For example, the BWT of the string } } " abracadabra " is " ard $ rcaaaabb ", and here it is represented by the matrix where each row is a rotation of the text, and the rows have been sorted lexicographically.
32.
The arithmetic coder maintains two high precision binary numbers, " p " low and " p " high, representing the possible range for the total probability that the model would assign to all strings lexicographically less than " x ", given the bits of " x " seen so far.
33.
In order to make the decision, you compare P to the string at M . If P is identical to M, you are done, but if not, you will have compared the first k characters of P and then decided whether P is lexicographically smaller or larger than M . Let's assume the outcome is that P is larger than M . So, in the next step, you consider ( M, . . ., R ) and a new central point M'in the middle:
