20 July 2014

IMO 2014 problem 1

This is an exercise proposed by Timothy Gowers: Write down all you think of while trying to solve a math problem.

18 July 2014

Predictive Causality

We know correlation does not imply causality. What does?

12 July 2014

Minimizing Weighted Automata via Linear Algebra

In this post I present the minimization problem for weighted automata, closely following a paper by Stefan Kiefer and Björn Wachter. I do add lots of steps that aren't necessary. To me, they make the result look less like magic. I really like the mixture of automata and linear algebra.

05 July 2014

Minimal Sets over Monotone Predicates

This post describes a very nice use of binary search. I learned about it from a paper by Joao Marques-Silva, Mikolas Janota, and Anton Belov.

04 July 2014

The Education Funnel

About the difficulty of national tests, and pass rates.

30 June 2014

Datalog and MaxSat: an Unexpected Match

In which I tell you how I got a bottle of Scotch.

23 June 2014

Nontransitive Dice

A probability puzzle, from TAoCP.