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John Baez (Mar 05 2023 at 18:35):Along with Feynman's theory of Feynman diagrams, Penrose's theory of spin networks was one of the big motivations for taking string diagrams seriously in category theory. A lot of Penrose's first papers on this subject are hard to get, so I've made them all available here:
Just yesterday I found John Mousorris' thesis online, and added it to this page. He was a student of Penrose who wrote a nice thesis on spin networks.
Joe Moeller (Mar 06 2023 at 15:43):Reading the first one. Just curious, who texed it up?
Joe Moeller (Mar 06 2023 at 15:53):Oh, I just saw a comment signed JB in the tex.
John Baez (Mar 06 2023 at 18:18):I didn't TeX it up. Someone named Georg Beyerle. It says so on my webpage. I did however make some fixes myself... I forget what that comment was, probably a tricky issue where something is probably a typo but not for sure.
Joe Moeller (Mar 06 2023 at 22:42):I see, I just didn't read past the words "latex source code."