# herbie (blogs) — RSS Amplifier Recent posts from the 3 feeds in the RSS Amplifier directory that cover herbie. Page: Feed: --- ## [What I learned as a composer from composer Pat Metheny](https://musicandourlives.substack.com/p/what-i-learned-as-a-composer-from) _2026-08-14 · Bob Gluck · Music and Our Lives_ Composers with distinct ideas about musical form offer something unique to learn ## [How the Moog synthesizer became a live performance instrument](https://musicandourlives.substack.com/p/how-the-moog-synthesizer-became-a) _2026-08-06 · Bob Gluck · Music and Our Lives_ From Herb Deutsch to The Monkeys to Keith Emerson, but where's Herbie Hancock? ## [Happy Throwback...](https://upbeatwithherbiejpilato.substack.com/p/happy-throwback) _2026-08-06 · Herbie J Pilato · The Upbeat News with Herbie J Pilato_ The Upbeat News with Herbie J Pilato is a reader-supported publication. ## [You Don't Need Expensive Facials and Creams to Have Nice Skin. Just Drink More Water, Stop Smoking, Drinking Alcohol, and Eating Crap](https://upbeatwithherbiejpilato.substack.com/p/you-dont-need-expensive-facials-and) _2026-08-02 · Herbie J Pilato · The Upbeat News with Herbie J Pilato_ The Ultimate Skincare Routine Costs $0 ## [Dr. Pat Gleeson, a Remembrance](https://musicandourlives.substack.com/p/dr-pat-gleeson-a-remembrance) _2026-07-30 · Bob Gluck · Music and Our Lives_ Always on the cutting edge and always true to himself ## [The Cold Reset: How Ice and Intention Rewire Your Stress Response](https://upbeatwithherbiejpilato.substack.com/p/the-cold-reset-how-ice-and-intention) _2026-07-27 · Herbie J Pilato · The Upbeat News with Herbie J Pilato_ A Healthy Way To Look At It ## [Herbie J Pilato: The Big Picture](https://upbeatwithherbiejpilato.substack.com/p/herbie-j-pilato-the-big-picture) _2026-07-25 · Herbie J Pilato · The Upbeat News with Herbie J Pilato_ An Update on My Life and Work ## [How a Neighbor's Complex Cat Brought Unexpected Blessings](https://upbeatwithherbiejpilato.substack.com/p/how-a-neighbors-complex-cat-brought) _2026-07-24 · Herbie J Pilato · The Upbeat News with Herbie J Pilato_ The Story of Nikita Maya ## [The saga of Herbie Hancock’s quadraphonic sound system –Pat Metheny was listening](https://musicandourlives.substack.com/p/the-saga-of-herbie-hancocks-quadraphonic) _2026-07-23 · Bob Gluck · Music and Our Lives_ More on Herbie Hancock's Mwandishi band ## [Be Vibrant...](https://upbeatwithherbiejpilato.substack.com/p/be-vibrant) _2026-07-22 · Herbie J Pilato · The Upbeat News with Herbie J Pilato_ The Upbeat News with Herbie J Pilato is a reader-supported publication. ## [Web Coding With AI, Live (Sponsored)](https://crawlproof.com/a/D3IQJYvy2X53) _2026-07-22 · **Sponsored**_ Collaborative screen sharing with simultaneous remote control, open source. ## [All Hail David Leaf: A Master Multi-Hyphenate Legend of the Entertainment Industry](https://upbeatwithherbiejpilato.substack.com/p/all-hail-david-leaf-a-master-multi) _2026-07-17 · Herbie J Pilato · The Upbeat News with Herbie J Pilato_ This Iconic Writer/Producer/Director Continues To Make His Indelible Mark on Culture and Humanity ## [Revisiting the repertoire of the Mwandishi band](https://musicandourlives.substack.com/p/revisiting-the-repertoire-of-the) _2026-07-17 · Bob Gluck · Music and Our Lives_ Learning from making a recording with two members of the original band ## [The Poisons of Sunscreen And How It Does Nothing To Help Your Skin or Health](https://upbeatwithherbiejpilato.substack.com/p/the-poisons-of-sunscreen-and-how) _2026-07-16 · Herbie J Pilato · The Upbeat News with Herbie J Pilato_ But You Can MAKE YOUR OWN Natural Sun Screen ## [The Enduring Voice of Peace](https://upbeatwithherbiejpilato.substack.com/p/the-enduring-voice-of-peace) _2026-07-12 · Herbie J Pilato · The Upbeat News with Herbie J Pilato_ The Peace Movement Through the Ages ## [Celebrating contingency and imperfection](https://musicandourlives.substack.com/p/celebrating-contingency-and-imperfection) _2026-07-10 · Bob Gluck · Music and Our Lives_ Learning from Garnett Brown and further pondering Herbie Hancock’s Mwandishi band ## ["Never strive for acceptance. Be exceptional." - Herbie J Pilato](https://upbeatwithherbiejpilato.substack.com/p/never-strive-for-acceptance-be-exceptional) _2026-07-05 · Herbie J Pilato · The Upbeat News with Herbie J Pilato_ "Never strive for acceptance. Be exceptional." - Herbie J Pilato ## [You’ll Know When You Get There in Italian](https://musicandourlives.substack.com/p/youll-know-when-you-get-there-in) _2026-07-03 · Bob Gluck · Music and Our Lives_ Working on an Italian edition of my book about Herbie Hancock's Mwandishi band ## [Music I’d most like you to know about](https://musicandourlives.substack.com/p/music-id-most-like-you-to-know-about) _2026-06-25 · Bob Gluck · Music and Our Lives_ 11 pieces by Coltrane, Mitchell, Takemitsu, Feldman, Hendrix, Taylor, Coleman, Holland, Hancock, Bach by Tureck, Subotnick ## [How listening to Pat Metheny led me to The Beatles](https://musicandourlives.substack.com/p/how-listening-to-pat-metheny-led) _2026-06-14 · Bob Gluck · Music and Our Lives_ From "Here, There, and Everywhere" to "Make a New World" ## [Shocking music](https://musicandourlives.substack.com/p/shocking-music) _2026-06-07 · Bob Gluck · Music and Our Lives_ Music that has altered my sense of what is music - what about you? ## [Real SIMs for AI Agents (Sponsored)](https://crawlproof.com/a/zBKEgUHR6YhQ) _2026-06-07 · **Sponsored**_ Pass 2FA and verifications with real carrier numbers via our API. ## [Unary Functions in an E-graph](https://pavpanchekha.com/blog/unary-functions.html) _2026-04-24 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ Functions of one variable are special in numerics: thanks to equioscillation , unary functions can be approximated efficiently by polynomials. For this reason, it can be useful to rewrite functions of multiple variables so that you get large unary fragments. For example, log(exp(a) + exp(b)) can be rewritten to: a + log(1 + exp(b - a)) The fragment log(1 + exp(x)) is a unary function; if we call… ## [LLM vs Kepler](https://pavpanchekha.com/blog/llk.html) _2026-04-08 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ The LLMs have gotten impressively good at certain intellectual activities. And one of the big promises that the AI labs seem to see here is the possibility of accelerating science; Dario talks about this in Machines of Loving Grace and OpenAI has had GPT-5 propose wet lab experiments . This is very cool. I like science! But Opus and Codex are sometimes kind of doofuses. And real science is not… ## [The Token Production System](https://pavpanchekha.com/blog/tps.html) _2026-02-19 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ I guess we are building software factories now. Dunno about that, but we do know how to build factories: the Toyota Production System . Information over Materials Materials flow through a factory: metals become parts become assemblies become cars. Each station can only produce so much. You might try to make each station more efficient, producing more materials in less time; but this is not the… ## [Agent Harnesses are Just Shells](https://pavpanchekha.com/blog/agents-are-shells.html) _2025-12-05 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ I do most of my AI coding using Amp . It is an AI "agent", meaning it is composed of two pieces. There's the AI model itself—currently Claude Opus 4.5—which runs on the model provider's servers over an API, and the agent harness, which runs on my machine and allows the AI to run commands, edit files, and so on. The AI model, eh, it crunches numbers. But the agent harness is an… ## [How to Start AI Coding](https://pavpanchekha.com/blog/coding-with-ai.html) _2025-12-04 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ On the one hand this is the most hyped topic ever so you'd think I have nothing to add. I don't feel that I do. But I'm known as the "AI Coding hype man" in my department and among many friends. They keep asking me how they're supposed to do AI coding. This blog post is an attempt to save time explaining. If you are happy with your AI coding setup, please just skip this blog post. This is an… ## [Should CSS be Constraints?](https://pavpanchekha.com/blog/why-css-bad.html) _2025-12-03 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ CSS is hard. The layout rules are quite complex. Most people don't know the details. Centering a \ is famously a challenge. Remember the 2000s, when A List Apart would run all sorts of crazy ways to achieve the "Holy Grail" layout—a header, a main body and sidebar of equal heights, and a footer? Should CSS layout—given that it's such a mess—just be thrown out, to start over with a totally… ## [We'd be Better Off with 9-bit Bytes](https://pavpanchekha.com/blog/9bit.html) _2025-08-06 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ A number of 70s computing systems had nine-bit bytes, most prominently the PDP-10, but today 1 \[ 1 Apparently, it was the System/360 that really set the standard here. \] all systems use 8-bit bytes and that now seems natural. 2 \[ 2 Though you still see RFCs use "octet", and the C standard has a CHAR\_BITS macro, to handle the possibility of a different-sized byte. \] As a power of two, eight is… ## [Distinguished (for me) Papers of PLDI'25](https://pavpanchekha.com/blog/pldi25.html) _2025-06-23 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ I had a blast at PLDI'25 this year! The best part, of course, was Marisa's talk about Spineless Traversal , but I wanted to take list the other highlights of the event, both for my own memory and for others who share my research taste. My inspiration is Phil Zucker , whose PLDI post is just phenomenal. I think of the papers below as getting a "Distinguished Paper" award from me. EGRAPHS'25 This… ## [Testing My M1 Simulator](https://pavpanchekha.com/blog/more-simulator.html) _2025-05-31 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ Ok, here's the story so far. Way back when I wanted to test whether sort + FastTwoSum is faster than TwoSum. But as I started optimizing it , I kept getting frustrated with how hard it is to benchmark low-level code, and eventually I wrote a simulator for my CPU, the Apple M1 chip. At this point, I was in too deep and wanted to keep improving the simulator. Compiling to Assembly As of the last… ## [Simulating Double-Double Addition Algorithms](https://pavpanchekha.com/blog/ddadd-simulate.html) _2025-05-30 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ I just read David's paper on floating-point accumulation networks. It's fantastic work: he's developed a new abstraction of floating-point numbers that allows him to verify error bounds for sequences of TwoSum-like operations, and then used that abstraction to design new, faster double-double addition algorithms. Since I already had a Apple M1 simulator on hand , I figured I'd give his algorithms… ## [Transcript-Driven Stock Discovery (Sponsored)](https://crawlproof.com/a/48hf0RTWYwJl) _2025-05-29 · **Sponsored**_ Ranked, evidence-backed watchlists from indexed executive transcripts for 1–2 quarter horizons ## [Some Surprising Quantifier Elimination Operators](https://pavpanchekha.com/blog/quantifier-elimination.html) _2025-05-26 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ I've been thinking about quantifier elimination, and one thing I have gained a new appreciation for is how much of our ordinary mathematical syntax exists in order to get quantifier elimination for common logics. This page lists a few examples. Modular arithmetic The mod operation, as in x % 3 , is necessary to eliminate existentials like: ∃ x, y = 3 x + 2 Here the quantifier elimination results… ## [LIN-graphs, an Egraph modulo T](https://pavpanchekha.com/blog/lin-graphs.html) _2025-05-23 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ I've recently been on a tear writing about Egraphs modulo T , first writing about polynomials specifically and later about the general case . My main insight is that pattern-matching, specifically relational e-matching, is related to quantifier elimination and the related notion of cell decomposition, which in fact lots of theories have. So I wanted to try to make this explicit in one of the… ## [Deciding Equality for Trigonometric Expressions](https://pavpanchekha.com/blog/trig-decision.html) _2025-05-21 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ One thing Herbie does is simplify stuff, and one that I am personally interested in is simplifying trigonometric expressions. For example, did you know that sin(x) / (1 + cos(x)) and (1 - sin(x)) / cos(x) are the same? Or that both are equal to tan(x / 2) ? But how can we do this automatically? Before I move on, a thank you to ChatGPT, mostly o3 and 4.1, for generative discussions. The Weirstrass… ## [Egraphs Modulo T (Attempt 1)](https://pavpanchekha.com/blog/egraph-t.html) _2025-05-21 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ Phil Zucker has been writing about Egraphs modulo T for a while now; see his latest blog post and latest paper for up to date efforts. I've been thinking about this too, and this post is my attempt to summarize. I'll be referencing Phil's ideas repeatedly, since all of my thoughts trace back to his. What is an E-graph (abstractly) An e-graph is for conjunctive reasoning with equality. Conjunctive… ## [How Operator Fusion Affects Error](https://pavpanchekha.com/blog/op-fusion-error.html) _2025-05-20 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ I have recently become a big fan of the condition number formalism for floating-point error; it is a simple mental model that explains a lot about floating point. In this blog post I want to use that mental model to investigate "operator fusion": basically, why library functions like log1p , cospi , or hypot improve error. 1 \[ 1 Actually, one of the big effects of hypot is to avoid overflow, which… ## [The Promise of P-Graphs](https://pavpanchekha.com/blog/p-graphs.html) _2025-05-19 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ In Herbie we use e-graphs to do algebraic rewriting of mathematical expressions. For example, in the Rust standard library's acosh function , e-graphs rewrite log(sqrt(x^2 + 1)) … into log(1 + sqrt(x^2 + 1) - 1) into log1p(sqrt(x^2 + 1) - 1) into log1p(x^2 / (sqrt(x^2 + 1) + 1)) into log1p(x / (sqrt(1 + (1/x)^2) + (1/x))) , Still, they're bad at some things, and one that really stands out… ## [Absorption in Double-Double Arithmetic](https://pavpanchekha.com/blog/double-double-absorption.html) _2025-05-14 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ In case you can't tell, I've been following a double - double rabbit-hole recently. Those previous two posts were about performance, but this one is about semantics. Specifically, it's about using double-double arithmetic as an oracle for standard double-precision arithmetic, and a specific issue, absorption , that comes up. Double-double oracles I have a dream of "safe" numerical programming,… ## [The Fastest TwoSum on an Apple M1](https://pavpanchekha.com/blog/more-fast-two-sum.html) _2025-05-12 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ In my last post , I pointed out that FastTwoSum plus a sort is actually faster than normal TwoSum on modern hardware, and suggested that TwoSum is therefore obsolete. This post expands the analysis and tests futher optimizations on the Apple M1 chip. General approach The general FastTwoSum algorithm is the following: s = a + b bb = s - a e = b - bb This assumes that |a| \> |b| , or perhaps a… ## [FastTwoSum is Faster Than TwoSum](https://pavpanchekha.com/blog/fast-two-sum.html) _2025-05-05 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ We all know that floating-point arithmetic is imprecise. When you do s = x + y , the value of s might not exactly be the sum of the values of x and y . Curiously (and importantly, for some applications), there's a way to quantify the imprecision: there's a family of algorithms 1 \[ 1 Called "error-free transformations", because they transform x and y into s and e without any error in the sum. \]… ## [ChatGPT o3 is the Real Deal](https://pavpanchekha.com/blog/o3-is-different.html) _2025-04-24 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ ChatGPT o3 (the full version, not the mini version I tested earlier ) came out just over a week ago . I used up my rate limit that day. It is the real deal, and I am blown away. I have been an LLM skeptic for a while. But this semester of paternity leave I decided that learning to use LLMs would be a goal, and I've been trying to use them more and more. And I'll be honest: I get a lot of value out… ## [Binary Search is Very Fast](https://pavpanchekha.com/blog/fast-bsearch.html) _2025-03-13 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ I've been practicing using LLMs (mostly OpenAI o3-mini-high ) for coding. It's good at quick prototypes, and I've recently been thinking about fast set membership operations (specifically related to CSS matching ). So I've had it implement a number of different binary search algorithms. The upshot is that modern CPUs are amazingly fast. Here's the fastest version I ended up with: int sSearch ( int… ## [How Stylo Matches CSS Selectors](https://pavpanchekha.com/blog/how-stylo-matches.html) _2025-03-07 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ I have long been interested in CSS selector matching algorithms . In short: existing selector matching algorithms are \\(O(d^2)\\) at worst, where \\(d\\) is the tree depth, and there are better algorithms that are \\(O(d)\\). But of course the constants matter a lot. I previously described both algorithms, and even showed that the bad cases can occur in practice. Recently I dove into the Stylo CSS… ## [Does O3 beat a specalized numeric compiler?](https://pavpanchekha.com/blog/o3-herbie.html) _2025-01-31 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ Alright, I'm back at it : comparing Herbie against LLMs to see who is best at numerical rewriting. If you're new here, Herbie is a research compiler I've been working on for about a decade that helps compile mathematical expressions to fast and accurate floating-point code. More recently, I've been comparing new OpenAI models against Herbie to see who is the top numerical analyst. So far, Herbie's… ## [Herbie Without Iterations](https://pavpanchekha.com/blog/e-herbie.html) _2025-01-14 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ This proposal suggests a radically different way Herbie could work, making use of high-quality oracle-free methods of evaluating error. This new method would make Herbie simpler, faster, and possibly better, while (I hope) maintaining all the things we currently like about Herbie. This new Herbie would use egg/egglog much more heavily than today, and the greedy improvement loop would be gone.… ## [A Plan for Herbie Plaforms](https://pavpanchekha.com/blog/herbie-platforms.html) _2024-12-28 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ This blog post is a design document, laying out how the platforms feature should work and how it should be organized. First—what is the platforms feature? I think it’s useful to separate out two parts: Users should be able to specify a platform when invoking Herbie. Users should also be able to make new platforms. Let’s consider each in turn, but first—a background on platforms. What is a… ## [A Tricky Herbie Bug](https://pavpanchekha.com/blog/an-ffi-bug.html) _2024-12-12 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ Today I found and fixed a Herbie bug. It had been bothering me for months: even when run with the same seed, Herbie's results are not reproducible. They're almost reproducible! They're close! But a few benchmarks, something like 5 or so, would differ from run to run. The bug was so tricky, so bizarre, that I just had to write about it. The bug I'll keep things short. I first tested a number of… ## [Not all Arithmetic Operations are Created Equal](https://pavpanchekha.com/blog/arith-ops.html) _2024-10-08 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ Floating-point code uses various functions on floating-point numbers, like arithmetic and elementary functions. When I got started working on floating-point error, I thought that was the ontology: arithmetic vs elementary. However, I now realize that it's more complex than that: it's useful to distinguish between floating-point operations based on their exactness. Exact operations (Group 0) These… ## [Batches as Virtual Mu Types](https://pavpanchekha.com/blog/batch-mu.html) _2024-09-15 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ This post is the third in a series of me trying to work out batches , a new data structure I am testing for Herbie and more generally for programming with recursive data structures. In my first post I laid out a type theory for batches, and in my second post I discussed how we can check that programs that use batches are safe. But I'm still after a "holy grail": how to making programming with… ## [OpenAI o1 vs. Herbie](https://pavpanchekha.com/blog/o1-herbie.html) _2024-09-13 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ A year and a half ago, I wrote a blog post comparing Herbie to the first ChatGPT (which we now call, I think, GPT 3.5). I chose 11 floating-point repair benchmarks, and fed all of them to Herbie and ChatGPT. Herbie is a tool my students and I develop to do exactly this work, and I wanted to know if AI tools had obsoleted it. The conclusion was that Herbie was still much better, winning 6/11 and… ## [Scheduling Batch Computations](https://pavpanchekha.com/blog/batch-schedules.html) _2024-09-03 · me@pavpanchekha.com (Pavel Panchekha) · Pavel Panchekha’s Blog_ Last time , I talked about batches, my term for an arena-allocated, flattened form of an AST, which I think is going to be a key data structure in Herbie. That post covered basics and sketched out a type theory; in this post I want to dive deeper into computating with batches. Batch Refresher & Index Safety Here's just a quick review from last time. A batch stores a recursive data structure like…