Joost Winter

Welcome to my academic homepage! I am a postdocoral researcher in the Faculty of Mathematics, Informatics and Mechanics at the University of Warsaw.

Previously I have obtained my PhD degree in Computer Science at the Radboud Universiteit Nijmegen, with a thesis titled Coalgebraic Characterizations of Automata-Theoretic Classes, under supervision of Jan Rutten and Marcello Bonsangue, and a MSc degree in Logic at the ILLC at the University of Amsterdam, with a thesis on transfinite computation, under supervision of Benedikt Löwe.

If you find any mistakes, errors, or unjustly omitted references in any of my papers, please mail me so I can add them to the list of errata!

Research interests

Coalgebra, bialgebra, formal languages and automata theory, formal power series, streams, automatic sequences, category theory, functional programming.


I am a teaching assistent for the lab of the course Języki i paradygmaty programowania (Programming languages and paradigms) in the Spring semester 2015-2016. See this page for more information.



Here you can find an erratum to the proofs of Christol's theorem found in various books.

PhD Thesis

You can view the defended version as well as the accompanying stellingen. Furthermore, I have prepared a list of errata as well as a revised version in which all of these errata have been incorporated.



For comments, e-mail to <>.

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