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Daniel Tubbenhauer: Three colors suffice

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[Originally posted 27 January, 2024] A late 20th birthday-present for Lewis Carroll. This is a talk he gave a few days ago at USC. The Temperley-Lieb algebra gives an amazing constructive proof which actually counts 3-colorings. It's an evaluation/reduction process. They were doing this the same year John Reynolds gave his tutorial “the application of the lambda calculus to programming languages”. See  Definitional Interpreters Revisted . [Update: See also  Temperley-Lieb Algebra: From Knot Theory to Logic and Computation via Quantum Mechanics  (2009) by Samson Abramsky]. Subscribe to Daniel Tubbenhauer .

David Corfield on Sweedler Theory for Systems

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So there was this guy called Moss Sweedler who, in the late sixties, was overthinking the whole algebra thing and invented half a dozen new verbs and adjectives to say what he thought, ...  See the talk description with a link to the slides  and Sweedler Theory of Monads by  Dylan McDermott, Exequiel Rivas and Tarmo Uustalu (2022) Sweedler theory for double categories by Vasileios Aravantinos-Sotiropoulos and Christina Vasilakopoulou (2023) It looks great. Now make it something the average free software programmer can understand and use to make the next version of the Gnome desktop and Firefox, because this stuff is rapidly becoming unmaintainable and unusable. See  The Story of Unix - Chapter Ω: The Captains All Jumped Ship and  Nir Lichtman's 12-minute Linux Distribution Video : This guy Corfield has had twenty years of funding in a top university and this is how far we've advanced since he wrote this in 2007 . See these papers by Samson Abramsky: What...

Ally Berry on a Monster in Cayuga Lake

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See  Ally Berry on Atmospheric Rivers . Cayuga Lake is the longest of western New York's glacial Finger Lakes, and is the second largest in surface area (marginally smaller than Seneca Lake) and volume. It is just under 40 miles long. Its average width is 1.7 miles, and it is 3.5 miles wide at its widest point near Aurora. It is approximately 435 feet deep at its deepest point.  My  comment : Wow, that was great! I loved that potted history of fringe festivals. When she said "It's great that there's this thing out there and nobody knows how big it is" I thought she's was talking about fringe festivals. I was thinking that if human behaviour can destroy ecosystems then it can also create them. So, people behaving as if this creature exists, even though it may not, and this conservation messaging persisting could eventually create an ecological niche, and who knows what will show up! 🦕  See Symbiosys TX and Brad Lancaster and Brandon on Land Restoration .  Sub...

Symbiosys TX and Brad Lancaster and Brandon on Land Restoration

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Here's the previous one on the solar panel farm and  Why Are People With Money So Fucking Stupid? Subscribe to Symbiosis TX .   Subscribe to Brad Lancaster . Subscribe to GrowTree Organics .  

Moby and Hana and Jazz on Addiction and Recovery

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I thought this was going to be a bit cringe, but it's not. It's really good. Subscribe to Moby . See her Patreon:  https://patreon.com/HanaClio . Subscribe to Hana Clio . Subscribe to Innerverse with Jazz Maia . There's no shortage of good advice on YouTube! See Symbiosys TX and Brad Lancaster and Brandon on Land Restoration .

Today's Adventures into Neurology

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  See  Assessing correspondence between subjective reports and visual targets during attempted out-of-body experiences by Marina Weiler, Damon Abraham, David J. P. Acunzo and Niffe Hermansson. My comment : That was really interesting, thank you. I had an out-of-body experience once. I was travelling in a taxi on a long dirt road and it was as if "I" had jumped out of my body into the body of the guy sitting in the front seat who was looking back at "me" and shouting at "me" except it was I who was desperately trying to say something but I couldn't and the "me" in the back seat was wearing a green t-shirt, whereas I was wearing a red one. It was a pretty complicated situation but it all sorted itself out and I apologised to everyone else in the taxi. They didn't seem too phased. But testing people with random images displayed on a laptop screen sounds incredibly unlikely to work because the whole setup is just meaningless representation. ...

Dana Scott on Lambda Calculus

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Talks in 2016. One at UCL in London The audio is rubbish on this, but it's mostly intelligible. Except at crucial points like 27:24 . What's the matter with people? Why doesn't anyone ever talk about how eta was described in Church's 1936 "Unsolvable problem" paper? It was basically reverse beta reduction.   See  An Unsolvable Problem of Elementary Number Theory by Alonzo Church; American Journal of Mathematics , Vol. 58, No. 2. (Apr., 1936), pp. 345-363. Subscribe to UCL Computer Science . One at the Simons Institute in California a few months later: See https://simons.berkeley.edu/talks/stochastic-lambda-calculus . In this talk he just brushes off extensionality and eta conversion 10:02  he says basically that it means "everything is a function" but he says he needs partial functions, so he rejects that rule. Subscribe to Simons Institute . I think students in Ljubljana are probably doing better at arithmetic than the ones in London and Berkeley. S...

Maggie Moved by a Movie

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You Can See Everything, ... Subscribe to Deepfocus Lens .

Jeffrey Sachs on NATO and The UN Security Council

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4:34 The UK's typical Contribution to security in the Middle East. See  Sylvie and Bruno Vol 1 - Page 51  and  John Searle on Human Civilization .  Subscribe to  NDTV World .  Larry Johnson addressed a UN Arria-formula meeting called by Russia: Subscribe to Daniel Davis . Glenn Diesen's interview with Martin Armstrong see  https://www.armstrongeconomics.com/ Subscribe to  Glenn Diesen .  Rachel Blevins on the latest Trump/Zelenski farce. Who's gonna rip-off who? Support her on Patreon to get the full rundown:  https://www.patreon.com/cw/rachelblevins . Subscribe to Rachel Blevins .

Sylvie and Bruno Vol 1 - Page 51

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... And I’ll take the title of Emperor, as soon as we can safely hold an Election. But they’ll hardly stand our using the Jewels , as long as they know the Warden’s alive. We must spread a report of his death. A little Conspiracy—”  “A Conspiracy!” cried the delighted lady, clapping her hands. “Of all things, I do like a Conspiracy! It’s so interesting!” The Vice-Warden and the Chancellor interchanged a wink or two. “Let her conspire to her heart’s content!” the cunning Chancellor whispered. “It’ll do no harm!”  “And when will the Conspiracy—” “Hist!”, her husband hastily interrupted her, as the door opened, ...  Get your free copy of Lewis Carroll's Sylvie & Bruno, Volumes I & II here .  See Jeffrey Sachs on NATO and The UN Security Council .  I think it's about time somebody formalised a proof that 1=2 in a few different theorem provers. See  Brady Haran interview with Terence Tao  and  Martyna Marciniak . Subscribe to Teddy Lambec .