2. Symbol: 'b'

Current code tree:

                Successor
No. Pred. Cont. "0"  "1"  Weight
 9.  11   NYA    -    -      0
10.  11   "a"    -    -      1
11.  Root        9   10      1

No leaf node is available for the symbol 'b'; new nodes are required for 'b' and NYA:

                Successor
No. Pred. Cont. "0"  "1"  Weight
 7.   9   NYA    -    -      0
 8.   9   "b"    -    -      1
 9.  11    -     7    8      0
10.  11   "a"    -    -      1
11.  Root        9   10      1

The weight of the current node has to be incremented:

                Successor
No. Pred. Cont. "0"  "1"  Weight
 7.   9   NYA    -    -      0
 8.   9   "b"    -    -      1
 9.  11    -     7    8      1
10.  11   "a"    -    -      1
11.  Root        9   10      1

Continue with the predecessor of the current node:

                Successor
No. Pred. Cont. "0"  "1"  Weight
 7.   9   NYA    -    -      0
 8.   9   "b"    -    -      1
 9.  11    -     7    8      1
10.  11   "a"    -    -      1
11.  Root        9   10      1

The current node is already the most significant node of the block. Therefore its weight may be incremented without exchange:

                Successor
No. Pred. Cont. "0"  "1"  Weight
 7.   9   NYA    -    -      0
 8.   9   "b"    -    -      1
 9.  11    -     7    8      1
10.  11   "a"    -    -      1
11.  Root        9   10      2

The root node is reached, the update procedure will be terminated.

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