Tag Archives: toroidal


Most of you have probably hear the sad news: Florian Kirch passed away last week. I can’t claim to have known him well; a little better after preparing for and competing at the WPC this year with him. That was a great experience, I’m glad I had the opportunity. The whole thing is quite a shock, more so since he seemed full of plans: He’s behind the first German youth sudoku championship that is being held this year, and was actively working towards a WPC hosted in Germany, besides a variety of activities in other fields.

If you’d like to solve some of the puzzles he constructed, I’ve collected what I was able to find. I’d be happy to extend the list. The 2015 Logic Masters certainly stands out, my favourite of his rounds there being “Vorsicht klebrig”, a set of Tapa, Fillomino and Slitherlink puzzles that had to be matched to normal, cylindrical and Klein bottle topologies.

I’ll close by reposting a puzzle dedicated to Florian’s memory that I first published here on the portal.


Rules Glue the grid to form a Klein bottle, by identifying one pair of opposing edges directly, the other pair after flipping. Then solve as an ordinary Tapa.