seanhunter
Joined 11 years ago
Joined 11 years ago
The computer in the back with the magnetic tape drive and thermal printer is an HP85a. We had one of those in about 1982-ish, which my dad bought for home use since they used HP equipment in his lab at work. My friend who had a Sinclair ZX-81 would marvel at the fact that (since we had an expansion cartridge) it had a mighty 32K of ram! Absolutely vast in comparison to the 1k of a ZX-81. The HP85a came with really great manuals which taught you how to program in basic, and had a wonderful keyboard. I have a ton of mechanical keyboards and I only once managed to get keycaps that feel as nice as the ones on the HP85a.
That calculator (which I think is an HP-67) also has some history for me. I can’t be exactly sure of the model number, but that looks like the one which was the first RPN calculator I ever programmed. My dad gave me some pocket money to translate a FORTRAN program he had written (which estimated something or other to do with some chemical process) to run on that calculator. He was really excited by the fact that a program he had written to run on an enormous university mainframe that took a whole floor now could run on a thing he could carry well, if not in his pocket (it’s a pretty chunky calculator) at least in his briefcase. That calculator has a really cool red segment display. Really an incredibly capable device due to wonderful design, it (like all HP RPN calculators) allows you to program literally any repeatable algorithm you can execute by hand on the calculator because it’s just a stack machine and you have everything you need (eg conditional branches etc). So that first program I wrote on it was using Newton-Raphson for something or other for example.
HP calculators used to be wonderfully robust so even a clumsy 10-ish year old like I must have been at the time was able to mess around with it in complete confidence that I wasn’t going to break my dad’s work device. There is a legend that a zookeeper was using an HP-12c calculator once to calculate ratios of ingredients and dropped it into the feed. The story goes that the calculator passed through the digestive tract of a hippo and was still able to calculate the yield to maturity on a bond (after cleaning). Source for the story (search for “tough construction): https://www.hpmuseum.org/hp12c.htm
The calculator survived the hippo's digestive process as well as the washing that followed.Kepler’s original theory was that the orbits in the solar system were defined by polygons and their inscribed/circumscribed spheres. This seemed very attractive because at that time they knew of 6 planetary bodies and this fitted in somehow (I don’t remember exactly) into this model with nested platonic solids and the spheres around them. Then Kepler realised that the predictions of this very elegant model were worse than the heliocentric model.
So when Brahe’s observations became available he basically threw all that out and started again, to develop his wonderfully elegant laws of planetary motion based around elliptical orbits which also have the significant benefits of predicting planetary motion beautifully and were later found to be entirely derivable from Newton’s laws of motion using calculus (there is a wonderful presentation of this derivation in Spivak for anyone who is interested).
Perl 5 was released in 1994. Palo Alto Networks was founded in 2005, so Perl 5 was certainly available when they built their first products and would have been a superior choice to either PHP or Perl 4.
What they’re not that great at is the type of improvements that really make a big difference: big simplifications etc. This is not super suprising when you understand how this works.
Firstly proofs in lean (and I think many other assistants) are essentially functions which take hypotheses and instantiate a particular type. That type being equivalent (due to the Curry-Howard correspondence) to a proof of some proposition. The assistant uses dependent type theory to make sure all the types match up at each step, which is what makes it rigorous. So the task of simplifying a proof is basically finding a route through an infinite-dimensional space where you know your starting location and the desired end point, but at any step you can go in basically any direction you like so long as you can justify your step. You justify a step by either choosing from a (vast at this point) library of lemmas and theorems that are in your standard library, or by recursively building the proof/function you need to justify the step you want to take using this same process you’re trying to use for simplification. This is incredibly flexible, but means you’re actually spoiled for choice and planning is hard.
Secondly, in “pen and paper” proofs, LLMs don’t know the difference between steps which are important/easy/hard/intuitive/non-intuitive for human mathematicians, so lots of the proofs they produce are extremely clunky and pedantic in places and dwell for ages over details that are obvious and would usually be skipped over and then will move very fast through things that justify more attention. This unevenness is part of what makes their proofs hard for humans to work through, but also means they are generally poor judges of what would actually constitute a decent simplification.
As an example, I've been using winnow running locally as a decision model in openchamber to select between llms for doing various tasks. I don't have an eval set of different coding and other tasks that I could use to train a proper classifier. This I just download off huggingface and it works out of the box and has cut my token spend to a fraction of what it was. So it's good enough to be beneficial.
https://en.wikipedia.org/wiki/Monstrous_moonshine
He has a youtube channel with lectures in number theory, category theory and other things.
To understand the regulatory framework for banks, the best place to start is the BIS and Basel III. https://www.bis.org/committees/bcbs/standards Generally speaking, international banks follow Basel III in addition to their domestic regulators’ capital requirements (which are probably also derived from Basel III, but have differences just to make things tedious).