[Sun, 14 Jun 2026 20:08:00 +0200] 1.2.0

I've written a wrapper around Donald Knuth's dlx1.c implementation of an exact-cover solver to use it from Python and started collecting some patterns for expressing more flexible constraints as equivalent exact-cover problems.

Equality by Exact Cover explores how integer equality can be expressed as an exact-cover problem, and Tiling Grids with (Directed) Loops uses the solver to fill a 2D grid with directed loops.

[Tue, 09 Jun 2026 20:59:00 +0200] 1.1.0

Regular Languages in Neo4j and Cypher explores how nondeterministic finite automata can be represented as graphs, and how path patterns can be used to find words in the regular languages accepted by these automata.

[Sat, 06 Jun 2026 23:34:00 +0200] 1.0.0

There's now a Changelog keeping track of how the content of this website changes over time.

I've rewritten the Index page to longer paragraphs and removed some unfinished or very short pages. If something went missing along the way, please let me know!

Simulating Slime Mold has some pretty images that don't look like slime mold at all.