Universal codes so there's one algorithm called problem if LZ somebody's and which works like this so I'll just try to very quickly describe it you're basically trying to so here's a long string that you're trying to compress and the way it works is that when you try to compress but you're at some position in the file let let's see we're at this position of the file and we want to code the future so what you do is you basically try to find a string starting at this position eight which has already occurred in the past so we