TSG = [東京大学理論科学グループ](http://tsg.ne.jp/) * [TSG Advent Calendar 2015](https://adventar.org/calendars/1015) * [TSG Advent Calendar 2016](https://adventar.org/calendars/1615) * [TSG Advent Calendar 2017](https://adventar.org/calendars/2708) * [TSG Advent Calendar 2018](https://adventar.or…