Mark Wildon's Website: Miscellany


Bristol maths. Swansea maths. Oxford maths. Cambridge maths. MathSciNet.

Seminars in London: Pure Mathematics Seminar (at RHUL), London Algebra Colloquium (at Imperial or QMUL), Information Security Group Seminar (at RHUL).

Seminars in Bristol: Algebra and Geometry Seminar, Heilbronn Seminar.

Seminars in Oxford: Representation Theory Seminar, Algebra Seminar.

People: John Baez, Dave Benson, Christine Bessenrodt, Simon Blackburn, John Britnell, Roger Bryant, Peter Cameron, David Craven, Anton Cox, Steve Doty, Charles Eaton, Karin Erdmann, Anton Evseev, Matt Fayers, Nick Gill, Jan Grabowski, Zen Harper, David Hemmer, Anne Henke, Gordon James, Sinead Lyle, John MacQuarrie, Paul Martin, Andrew Mathas, John Murray, Nikolay Nikolov, Alison Parker, Sarah Rees, Jeremy Rickard, Sibylle Schroll, Peter Symonds, Matt Towers.

Oxford algebra group. BLOC homepage. Representation theory on the Arxiv. Rail timetable. Trinity College. Part III courses. Unix help. LaTeX tips. Kew Gardens. Improbable Science.


A program to help one visualise complex functions. It was written in Objective C for Mac OS X (an amazingly nice way to program, even if the basic language is C). Here is a screenshot. Here is a link to version 0.22 which should work on Mac OS X 10.6 and later. (For changes see here.)

I wrote this program after Matt Towers implemented the idea in Java: he has kindly given me permission to mirror his applet version here.

Monads and Haskell

While category theory is ubiquitious in modern algebra, it seems at least as well suited to describing what's going on in functional programming languages. Some links: Real world Haskell (I suspect this may become a classic),, Monads for the working Haskell programmer, Monad tranformers, Glasgow Haskell Compiler, some nice exercises.

I plan, one day, to write some sort of introductory account (for mathematicians) of how monads arise in functional programming, and their use in unifying the programming required to solve problems which appear to require some sort of back-tracking: sudoku, finding a matching in a bipartite graph, chess, poker, etc.

The picture on the left comes from my attempt at a Oxford Comlab practical on L-Systems.


Mostly rather old now, but sometimes surprisingly relevant.


Index of spoilers. Probably too easy to exploit, but I can recommend Sporkhack for more of a challenge.

How to teach quotient groups

When young and brash, I had strong views (1999) on this subject.

Last modified: 04/09/12. Email: