Diagram chasing | visualizing five lemma as a game

Diagram chasing | visualizing five lemma as a game

The glass disk game is played on a grid. You have translucent colored glass disks you can either place on an edge or a vertex. There are two kinds of disks that can be placed on an edge: blue or yellow. A vertex with a blue and yellow disk looks green. There are two kinds of disks that can be placed on a vertex: red or white. A vertex with a red and white disk looks pink. For this post we only need red disks. We may use white and pink in a futur…