We ran our previous <xtree> example, giving it the Gettysburg address, and we find:
that occured 13 times the occured 11 times we occured 10 times here occured 8 times to occured 8 times a occured 7 times and occured 6 times for occured 5 times have occured 5 times it occured 5 times
The advantage to <xtree> , besides maintaining a searchable list of strings, is that it is extremely fast at lookup, which we need in a situation like this where many words are being inserted.
For more details, see the Vortex manual on <xtree> .