This third mini-event, organized by One World Combinatorics on Words Seminar, is designed to take the place of a small and very informal conference in our field, since many of us miss direct communication of this kind. The page of the previous Day of short talks is here.

As usual, the event will consist of short talks in 25-minute slots, including your new results, discussions, and open questions. This time, researchers from other fields who use combinatorics on words are especially welcome.

If you want to give a talk, please write a message to Anna Frid.

Jarosław Duda Generalized Fibonacci coding problem using Maximal Entropy Random Walk and Asymmetric Numeral Systems

In Fibonacci coding we forbid '11' patterns, bringing question of generalization to more complex constraints. I will very briefly present how to practically handle such general situation, including 2D lattice (hard square problem), with motivation e.g. to increase capacity of hard disk. We will first find probability distribution of patterns in such ensemble of sequences, which can be obtained with MERW ( https://en.wikipedia.org/wiki/Maximal_entropy_random_walk ). Then we can use entropy coder - for this purpose I have introduced ANS ( https://en.wikipedia.org/wiki/Asymmetric_numeral_systems ): generalization of numeral systems to optimize for a chosen probability distribution of digits. I will also briefly present its two widely used variants: rANS with multiplication - now e.g. in JPEG XL image format, or tANS building finite state automaton for a given probability distribution - now used e.g. in Facebook Zstandard or Apple LZFSE compressors.