Joshua Cox

I am a person.

Recreational maths, computing and games

The number of asterisks is a rough indicator of the page’s length, interest or usefulness.

\(\mathord{\ast}\)	Hindley–Milner	??
\(\mathord{\ast}\)	Benson’s theorem (a characterisation of unconditional life in Go)	??
	Ackermann-coding the hereditarily-finite sets \(V_\omega\)	??
	The combinatorial number system, or combinadics	??
	A function \(f : \mathbb{R} \to \mathbb{R}\) taking every value on every non-empty open interval	5th May 2025
\(\mathord{\ast}\mathord{\ast}\)	A solver for any system of congruences \(\{a_1x\equiv b_1 \pmod{m_1},\ldots,a_nx\equiv b_n\pmod{m_n}\}\) for \(n\in\mathbb{N},a_i,b_i,m_i\in\mathbb{Z},m_i\neq 0\).	3rd May 2025
	Noodle problems	22nd April 2025
\(\mathord{\ast}\)	Maximal products of numbers with a given sum; the four cases of [lists, \(k\)-tuples] × [\(\mathbb{Z}^+\) and \(\mathbb{R}^+\)]	12th April 2025
\(\mathord{\ast}\)	Tengwar keyboard ()	27th January 2025
\(\mathord{\ast}\mathord{\ast}\)	Solving Mario Poker	18th January 2025
	Counting necklaces and bracelets of a fixed multiset of beads	??
\(\mathord{\ast}\)	A symmetric statement of the inclusion–exclusion principle and a nice proof	??
\(\mathord{\ast}\mathord{\ast}\mathord{\ast}\)	An interactive solver for Kaleidoscope Classic tiling puzzles	??
\(\mathord{\ast}\mathord{\ast}\)	A sequent calculus prover for classical propositional logic	??
	IMO 2020 Problem 3	??
	Formally stating the rules of Go	??

Recital programmes

I like to design recital programmes. One day I might play them…

	Borodin, Ravel, Beethoven, for piano	~April 2025
	Consolations, for piano	~April 2025
	Hommage à Couperin, for harpsichord and piano	~April 2025

Recipes

None of these are original.

Naleśniki ze szpinakiem (Polish pancakes)

~April 2025