mauls@warwick.ac.uk (The Chief Slime Monster) (04/12/91)
With all this talk of finding strings in infinite expansions I thought I would mention something a colleague and I thought of. I don't spose it is original, in fact, you've probably all read it before in this newsgroup, but here goes. A chain function is just a function that generates a finite number of unique values and then cycles: i.e. f(n) = f(1), for some n, otherwise all f(i) != f(j) 1<=i<j<n. The postulation was this: Consider file as binary string length L. There exists a chain function which will step uniquely through every possible binary string of length L before repeating. Then, if the file string is equal to f(N), where f is the chain function, and N is a number, replace the string with the binary representation of N. To decompress, just calculate f(N). Not surprisingly, the representation of N is not, on average, smaller than the file string. Slime