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 interval5th 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 problems22nd 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 Poker18th 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