Git, mercurial, and synchronized repositories

The first version control system I used was CSV, then I moved to Subversion as everyone else does. Later, people start to look for server-less solutions and I used Mercurial. I even made a cheatsheet about it that is now the top result on Google for searching “mercurial cheatsheet”. But... [more]

Twelvefold of combinatorics

Recently I come across the term “Twelvefold way” of combinatorics. I wish I knew the term earlier as I studied quite many of those in the graduate schools and collected “recipes” for them. I always thought of them as some cases of urn models of George Pólya but they indeed... [more]