This has probably been posted before but since Category Theory has been popping up every once in a while I thought I'd share this. I'm just starting this and th

This has probably been posted before but since Category Theory has been popping up every once in a while I thought I'd share this. I'm just starting this and the instructors' [book](https://arxiv.org/abs/1803.05316 https://arxiv.org/abs/1803.05316) here, and the subject is very approachable even for biologists like myself.