Yes, The formulas reduces to (2^K) - 2. If you accept the case of zero bit file, then when you send the compressor the length of the file to be decompressed send, a indeterminate value. On resend, send again the indeterminate value to confirm. Then have the compressor map this to the last remaining file. If "NOTHING" can be mapped to a file, then "SOMETHING BROKEN" is over qualified to be mapped to a file. It at least screams out its existences in a directory; a file not there is simply not there. Then, now this is serious, by mathematical induction we can then reduce all compressed files of bigger size further to smaller files and eventually all files are mapped to either zero bit or indeterminant bit size. We didn't just bash a few theorems. We've just collasped the universe to void by a series of mapping. Given "NOTHING" , and depending on which path (of mapping) taken, any files can be recovered. Algorithmic compession!!!!!! Which is something we all have at the back of our mind isn't it. Crazier everyday! Dale King wrote in message news:<38B6C9DB.70229F50@tce.com>... > And doing the math gives you (2^K)-2 for the first formula and 2 for the > second one. The only difference then between our formulas is that you > don't believe you can have a zero byte file. >