Descriptions at: * ''Data Compression'' [http://www.ics.uci.edu/~dan/pubs/DataCompression.html] * ''Dr. Dobb's'' article [http://dogma.net/markn/articles/arith/part1.htm], with sample C code Closely related is the ''Range Encoder'', see [http://www.compressconsult.com/rangecoder/]