Lambda Diagrams

I had a picnic this weekend and at it I gave Phil a pen plot that I had been meaning to for a while: I want to explain it here because I think it's cool! This was drawn with a pen plotter, which is a kind of robotic arm that you can place a pen in, and program to draw very precisely. The result is that you can get crisper lines, that were drawn with a pen instead of inkjet (which also means you…