yep. I’m goin to bed

But now imagine the same proof in plain text, rather than with a diagram! :sweat_smile:

I am getting flash backs. Only thing I remember is to use the “snake lemma” :slightly_smiling_face:

Actually, I’m reminded of what somebody said at a PLMW (https://icfp20.sigplan.org/home/PLMW-icfp-2020?) talk last year. It was roughly along the lines of “even those of us who are experienced in the Programming Languages field can have a lot of difficulty figuring out what a paper is saying - not necessarily because the material is too advanced, but because the paper is written very obtusely”.