I understand that the contestant gets to specify a "decompressor"; my point is that this is not information-theoretically relevant. The real decompressor in thi

I understand that the contestant gets to specify a "decompressor"; my point is that this is not information-theoretically relevant. The real decompressor in this challenge is the Linux/C runtime environment. The "decompression" program you send is really just part of the compressed payload, and whatever steps you, as a human, take to produce the compressed payload (encompassing both the code and data portions) are ultimately governed by information theoretic limitations. Another way to say this is that although you have the 'privilege' of a designing a custom decompressor for this one file, this is not really a benefit since your custom decompressor counts against the space limit. (in contrast to the typical information-theoretic setting where the channel can have an arbitrary pre-specified decoder).