All posts
Three tracks. The Antivision experiment, which changes with every run; the GPT-2 course, which is the foundation; and the Column, the personal part. Start with what is new, or with what matters most.
What's new
The most recent chapters of the experiment. Some still wait for the run that closes them.
What changed on 17/09: two new chapters and two corrections
In one day the experiment gained two chapters and corrected two claims I had already published.
read the post →chapter 19 · recentThe inversion that did not repeat: the world model's cost appears once the ruler stops swinging
I wrote in a chapter that my world model made the generator 3.38% better. With more seeds and a fixed ruler, it costs.
read the post →chapter 18 · recentSearching better does not fix the energy: three searches, the same text
I fixed my model's search so it finds the true lowest energy, among 16,392 options. The text did not get better.
read the post →Highlights
If you read only one from each track, read these.
Token does not measure delivered work. And between two people, it does not measure the same thing
"Token" does not measure delivered work. And between two people, it does not measure the same thing either.
Experiment · 00Antivision: an ELLM, a language model that rehearses in latent space before speaking
An LLM picks the next token and finds out afterwards where it ended up. We built one that imagines first: an ELLM.
Experiment · 05The rudder and the world model: three versions of the same question, each measured against the last
The question is a single one: does the model know where it is going before it goes?
Experiment · 12Learned costs and inference modes: the three searches and the two sources of energy, measured
On the first reading, no inference mode governed. Free generation had more heading than any planner.
Experiment · 13The corrections from LeCun's talks: failure, passage, flag, measurement
A queue of 22 runs left four measured failures. We took each back to LeCun's text with a single question.
Experiment · 16The minimum was off the list: the day I measured my own search by energy
For weeks I said my system picked the next word by "searching for the lowest energy". I went and measured it. In 96 tests, it never found the lowest energy once.
Experiment · 17ELLM: the right name for a language model that predicts in latent space and decides by energy
I called my model an LLM for months. The name was wrong — and not because of its size.
Experiment · 18Searching better does not fix the energy: three searches, the same text
I fixed my model's search so it finds the true lowest energy, among 16,392 options. The text did not get better.
Experiment · 19The inversion that did not repeat: the world model's cost appears once the ruler stops swinging
I wrote in a chapter that my world model made the generator 3.38% better. With more seeds and a fixed ruler, it costs.
Course · GlossaryCourse glossary: what token, layer and model mean in AI, and in the rest of IT
"Token" already had other owners before AI: the compiler, the login and the blockchain.
Course · 09GPT-1 to GPT-2: same size, half the perplexity. Four decisions explain it
Do you know how GPT-1 became GPT-2? And why it happens?
Course · 11Encoder vs decoder: one line of code and every consequence that descends from it
A minus-infinity sign decides whether the model writes or understands. There is no free lunch.
Course · 15The lab guide: every command, every script, and everything that was measured
GPT-2 opened the path behind every LLM you use today. How far does that path go?
Antivision · Latent Rehearsal
Not a course. An experiment of proof and continuous improvement: every piece is measured against a control, what fails is recorded with the same prominence as what works, and the next run starts from what the previous one measured. The chapters are the diary of that experiment, in the order it happened.
- 00Antivision: an ELLM, a language model that rehearses in latent space before speakingAn LLM picks the next token and finds out afterwards where it ended up. We built one that imagines first: an ELLM.highlightclosedupdated 12 Sept
- 01The custom tokenizer: why 16 thousand tokens suit this corpus better than 50 thousand, and what the whole table showsA 7-million-parameter model used fewer bits than the 124-million GPT-2 in Portuguese. Not because it is better.closedupdated 12 Sept
- 02Two architectures, one file: the fair duel between 2019 and what came afterA new piece is presented under the conditions of whoever built it. We redid the comparison under ours: same data, same seed, same budget.closedupdated 12 Sept
- 03The geometry of the embedding: training starts with a perfect space and ruins itWe tried semantic search with RoBERTa. Every similarity came out above 0.99. Sentences on opposite subjects looked identical.closedupdated 12 Sept
- 04The lineage of collapse: five answers from computer vision, each measured on textA system trained to predict in latent space has a trivial solution: ignore the input and always return the same vector. Perfect and useless prediction.closedupdated 12 Sept
- 05The rudder and the world model: three versions of the same question, each measured against the lastThe question is a single one: does the model know where it is going before it goes?highlightclosedupdated 12 Sept
- 06Method and mistakes: the rules of a legitimate comparison and the catalogue of our own errorsHalf of the best decisions in this project came from finding out we were wrong.closedupdated 12 Sept
- 07Scale and budget: what it costs to reach GPT-3, and why VRAM is almost never the limitReaching the scale of GPT-3 Small costs less than eight hours of a single GPU. What is missing is not the card. It is text.closedupdated 12 Sept
- 08The workbench: serve, x-ray and train from the browserWe measured where the time of a request goes. 93.3% is serial generation, token by token.closedupdated 12 Sept
- 09The hierarchical architecture: the whole project aligned to the four patterns of the world modelLeCun has a slide with four lines: abandon X in favour of Y. We audited our code against each one.closedupdated 12 Sept
- 10What JEPA is, according to LeCun: two talks read concept by concept, and where each one appliesThe video that started it all: Yann LeCun explaining what LLMs still lack to understand the world. We read it concept by concept and applied it to text.closedupdated 12 Sept
- 11Memory and horizon: two claims from LeCun that became experiments, and both hold for textLeCun says: each level of abstraction predicts further than the one below. We measured. It holds for text.closedupdated 12 Sept
- 12Learned costs and inference modes: the three searches and the two sources of energy, measuredOn the first reading, no inference mode governed. Free generation had more heading than any planner.highlightclosedupdated 12 Sept
- 13The corrections from LeCun's talks: failure, passage, flag, measurementA queue of 22 runs left four measured failures. We took each back to LeCun's text with a single question.highlightclosedupdated 12 Sept
- 14Consulted memory: a bank of abstract states read by attentionSummed memory persists, but dilutes: the whole past is worth less than each half alone.closedupdated 12 Sept
- 15What it costs and what it delivers: us, GPT-1 and GPT-2 on the only ruler valid across tokenizers"Our model has perplexity 31, GPT-2 has 29, so GPT-2 is better." That means nothing.closedupdated 12 Sept
- 16The minimum was off the list: the day I measured my own search by energyFor weeks I said my system picked the next word by "searching for the lowest energy". I went and measured it. In 96 tests, it never found the lowest energy once.highlightclosedupdated 12 Sept
- 17ELLM: the right name for a language model that predicts in latent space and decides by energyI called my model an LLM for months. The name was wrong — and not because of its size.highlightclosed
- 18Searching better does not fix the energy: three searches, the same textI fixed my model's search so it finds the true lowest energy, among 16,392 options. The text did not get better.recenthighlightclosed
- 19The inversion that did not repeat: the world model's cost appears once the ruler stops swingingI wrote in a chapter that my world model made the generator 3.38% better. With more seeds and a fixed ruler, it costs.recenthighlightclosed
- 20What changed on 17/09: two new chapters and two correctionsIn one day the experiment gained two chapters and corrected two claims I had already published.recentclosed
Column
Not a course, not an experiment. The personal part: an idea going around, read with the course's vocabulary and checked on the bench when it can be checked.
- ·Token does not measure delivered work. And between two people, it does not measure the same thing"Token" does not measure delivered work. And between two people, it does not measure the same thing either.highlight 16 Sept
GPT-1 and GPT-2, taken apart
A course: each chapter teaches one piece of the model and proves it in a lab that runs on your machine.
- 00The seven fossils: why GPT-1, GPT-2 and RoBERTa are a historical cross-section, not a listSeven files on Hugging Face record the exact moment language AI split in two.
- GlossaryCourse glossary: what token, layer and model mean in AI, and in the rest of IT"Token" already had other owners before AI: the compiler, the login and the blockchain.highlight
- 01Why GPT-2 sees neither letters nor words, and what that costs in PortugueseGPT-2 has never read a word of yours. Not even a letter. It reads pieces.
- 02Embeddings: from a meaningless integer to a vector that knows king and queen are relatedTo the model, cat is 4899 and dog is 5257. Feeding that into a neural network is a serious conceptual error.
- 03Attention: the single operation that replaced twenty years of recurrent networks"The trophy didn't fit in the suitcase because it was too big." What is 'it'?
- 04Twelve heads instead of one, and the single line of code that separates GPT from RoBERTaAttention is a fixed budget: every row sums to 1. If 70% goes to one word, 30% is left for everything else.
- 05Why GPT-2 needs 48 floors to answer, and what happens inside each oneWhen you send ChatGPT a question, it climbs 96 floors before it becomes an answer. In GPT-2 it was 48. Every floor does the same thing. So why so many?
- 06What scale really buys: from 124 million to 1.5 billion, measuredGPT-2 large, with 774 million parameters, got the capital of France wrong. Medium, with 355 million, got it right.
- 07Temperature, top-k and top-p: the decision that changes the text more than switching modelsThe model does not choose the next word. You do.
- 08Perplexity: the one number that says what the model learned, without anecdotesGPT-2 was never taught to answer questions. It was trained on a single task, billions of times.
- 09GPT-1 to GPT-2: same size, half the perplexity. Four decisions explain itDo you know how GPT-1 became GPT-2? And why it happens?highlight
- 10RoBERTa: when the advance is training better what already existedFour months after GPT-1, Google took the same block and made the opposite decision.
- 11Encoder vs decoder: one line of code and every consequence that descends from itA minus-infinity sign decides whether the model writes or understands. There is no free lunch.highlight
- 12The detector: how a language model becomes a classifier, and why this one should decide nothingOpenAI built the hunter with the architecture opposite to the prey's. And since 2023 it is worse than useless.
- 13Reading GPT-2's original code: 174 lines against everything you learnedThe whole of GPT-2 fits in 174 lines of TensorFlow. And you can read every one of them.
- 14Serving models: from function call to HTTP server, and what production does on topLoading GPT-2 XL costs 7 seconds and 5.8 GB of RAM. Every single time.
- 15The lab guide: every command, every script, and everything that was measuredGPT-2 opened the path behind every LLM you use today. How far does that path go?highlight
- 16The ceiling of this path: LeCun's argument, read from inside GPT-2Every text humanity has written fits inside what a four-year-old has already seen.