Sperner’s lemma

I found a proof of Sperner’s lemma that I am quite satisfied with a few months ago. I’ll repeat the proof here, but more importantly I’d like to share my thought process that lead to the proof. What is Sperner’s lemma? Look at the triangle below. It’s divided into smaller triangles, and each vertex is colored either red, green, or blue. The edges of the large triangle are each missing each of the three Read more…