bit string B 0 you can compress it to get a smaller bit string B 1 if it strictly last bits otherwise it's not a universal compressor now B you want you can feed into it again it'll turn that into B 2 which is yet smaller you keep doing this you do this especially many times at some point you'll have a big string of size 0 at that point it's obvious you cannot recover what the earth will lost kiss you it could have been anything and everything gets turned into 0 you can get back out will int it so what this shows them assuming