Random Stuff I Made

• Debirdify, a tool that uses the Twitter API to help you find people you follow on Twitter in Mastodon and elsewhere in the Fediverse. Also works for lists, followers, blocked accounts, muted accounts, etc.
• Cleaned-up versions of my team's winning solutions for the Proof Ground competition at ITP 2019.
• A small Haskell-based text snippet pasting service with Isabelle highlighting (I had to add password protection due to spam and being to lazy to implement a data-protection-conforming CAPTCHA – sorry!)
• A very small (∼250 LOC not counting GUI), ray tracing demo in Java (with commented source code) that illustrates the process of ray tracing. I made this when I was a BSc student and it fills me with nostalgia, so I leave it on here.

Personal Interests

• Learning languages, linguistics, and phonetics
• In particular: learning and speaking Esperanto (bonvolu kontakti min se vi volas paroli Esperanton kun mi!)
• Bouldering and climbing
• Playing the accordion and the low whistle

Recommended links

• The website of Isabelle, the Interactive Theorem Prover with which I work
• The free Concrete Semantics book by Nipkow and Klein, which serves as a good introduction to both Isabelle and the subject of programming language semantics
• Another free Isabelle-related textbook, Functional Data Structures and Algorithms. A Proof Assistant Approach by Nipkow et al. This one includes a chapter on median-of-medians selection by me.
• A web cartoon every student should know. And probably everyone who works at a university as well.