The Eternal Doorman

I just found out that POPL 2024 had some talks about program synthesis. This reminded me of the Criterion Problem. See  Ways to Do Telecommunications : Subscribe to ACM SIGPLAN .

This is great! See Hackaday Europe 2026: Half Quad, Half Blimp: Test. Fly. Survive . Subscribe to Hackaday .

See  Jean-Yves Girard - Lectures at IHP thematic trimester : Semantics of proofs and certified mathematics  for more charcuterie. It's where the sausages are all hanging up around the ceiling, ... Subscribe to Julie Nolke .  

My comment : That was a really clear explanation, thank you. Can you talk sometime about how it is that these protocols are not used for basic data protection? I mean why is age verification such a big deal? Can't a zero knowledge protocol be used to verify someone's age without divulging their full identity? I know there is probably a different motive behind the age verification thing, but why does nobody talk about alternative solutions that don't involve personal identity data? I think it has much wider application though. For example, say I want to order and pay for something and have it delivered to me without divulging my identity or the delivery address or my bank details. One would think that it would be possible for my bank to give me some proof that I have commited to pay a certain amount to some entity, a sort of single use cheque, which I could then commit to using to pay the supplier, who then commits to send the goods via a chain of carriers who each similary ...

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Just testing stuff: SVG You can click on the blue circle: MathML There is not much you can do with this. See Mathematical Markup Language 1.01 Specification   7.1.5 Mixing and Linking MathML and HTML . It's the big problem  of how you compose languages.   a x 2 + b x + c = 0 You can click on the discriminant: x = − b ± b 2 − 4 ⁢ a ⁢ c 2 ⁢ a 2D Canvas Sound  Beep! WebGPU Next level Parser expression grammar compiler:  https://peggyjs.org/online.html Devine Lu Linvega's unxtal assembler/debugger:  https://wiki.xxi...

We have all these machines, but they aren't doing the right stuff because of the hidden agenda : they were never meant to do stuff we needed them to do, they were meant to be ways for other people to use to get us to do stuff. See  FUTO FUBS and the Everything App . I was prompted to write this by Girard's question "What is a question?" and his remarks about a DVD player at 17:42 in  Jean-Yves Girard - Lectures at IHP thematic trimester : Semantics of proofs and certified mathematics .  The example question he gives is how do you know that it is a DVD player? And the answer is that you put in a DVD and it asks you a question!  It struck me the other day that the way most people think of programming is quite different to how I think of it. I think of it as composition of ideas in a bottom-up sense: I have some ideas and they're like Legos, so I have a box of all sorts of ideas and each time I learn a new one it goes in the box. Then when I am feeling creative I im...

Lectures given in April 2014. You can really tell he was at a French University in 1968 ! Qu'est-ce qu'une réponse ? (l'analytique)  47:53 On Gentzen's distinction between implication and cut and Lewis Carroll's What the Tortoise said to Achilles . Around the time he was presenting these lectures in Paris I was homeless in Caranavi, Bolivia writing to people in Cambridge about exactly this subject. He doesn't seem to have thought of the possibility that Lewis Carroll, who was a geometer, might have been talking about something more than symbolic logic. The form of the five common notions in the Elements is that of formal rules of inference, and that is how they are used implicitly in proofs: (A) Things that are equal to the same are equal to each other. (B) The two sides of this Triangle are things that are equal to the same. (Z) The two sides of this Triangle are equal to each other.   Consider whether the character of (A) is that of a statement about a geome...

On Aristotelian physics, I was wondering about the last line of this Proposition: To set out the sides of the five figures and compare them with one another . Here Euclid proves that if a dodecahedron and an icosahedron are inscribed in the same sphere, then side of the icosahedron is greater than the side of the dodecahedron. One might think (because I did) that the icosahedron , having twenty faces, would have a greater volume than the dodecahedron inscribed in the same sphere, because the dodecahedron has only twelve faces and so should be a poorer approximation to a sphere as a result, but this intuition is false. One similarly might expect the sides of the icosahedron to be shorter than those of the dodecahedron for similar reasons, but neither is that true. However, the dodecahedron and icosahedron are dual each to the other, meaning that they each have the same number of edges, and if you swap faces with vertices you get the dual polyhedron. In both figures, opposite edges are ...