"ABSTRACT: The Walrus coder does the same job as a binary arithmetic coder-- "binary" meaning having an input alphabet of just two symbols. The Walrus has the same API as arithmetic coders, and similar coding efficiency and latency, but the Walrus maps symbols to bits differently: at each step it designates one of the two symbols "walrus" and the other "eggman." The walrus is assigned an available bit string, which is then either output (if walrus is sent) or made unavailable (if eggman is sent). ... This file is "literate executable pseudocode" in Python... An appendix contains test code... A separate Jupyter notebook [N] does some analysis [and graphs] of the Walrus's efficiency both empirically and theoretically." http://www.mac-guyver.com/switham/2020/11/Walrus  --Steve