The Long Mathematical Path to Transformers
October 25, 2023

Transformers condense an enormous mathematical lineage into one executable architecture. Understanding them deeply connects probability, optimization, dynamical systems, tensor algebra, information theory, sequence models, sampling, tokenization, and chip arithmetic.

Brian Greenforest maps that lineage as a complete curriculum for people who want to build the model rather than operate only its interface.

Start With Probability, Dynamics, and Optimization

Joint and conditional probability, Bayes rules, maximum entropy, mutual information, experimental design, Gaussian mixtures, PCA, ICA, hidden Markov models, autoregression, Q-learning, Pontryagin, Euler-Lagrange, dynamic programming, and Hamilton-Jacobi-Bellman equations establish the modeling foundation.

Kernels, convolution, central-limit behavior, nonlinear embeddings, Hilbert problems, topological spaces, and tensor contraction explain how representations carry complex relationships.

Follow the Architecture Into Training and Hardware

RNNs, LSTMs, attention, cross-attention, causal masking, KV caches, RoPE, normalization, GLU-family activations, dropout, initialization, momentum, minibatches, adaptive spans, sparse attention, grouped-query attention, tokenizers, temperature, top-k sampling, and logits define the modern model path.

FMA, GEMM, Hadamard products, bfloat16, quantization, binarized weights, memory movement, and fused kernels determine how that mathematics runs. Students can use this map as a multi-year path from first principles to original Transformer and AI-chip work.

Run The Long Mathematical Path to Transformers in a Four-Layer Transformer

The complete training run connects this mathematical argument to executable code, data flow, and a working small model.

Four-Layer Tiny Transformer Training Run

Originally posted on LinkedIn

Brian Greenforest · (2023-10-25 17:02:20 UTC)

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To learn math of Transformers you just have to study Calculus and mathematical analysis for five years at uni, for 10 years out of curiosity, then four years of self-guided intensive crash course. From EM, HMM, Q-learning, Pontryagin, Euler-Lagrange, mean, joint and conditional probability, Bayes rule, chances, odds, observations, events, controls, factor analysis, design of experiments, Chi-square, k-NN, k-means, maximum entropy, mutual information, sliding Gaussians, central limit theorem, law of large numbers, kernels as measures, convolution, scaled windows, tensor analysis, topological spaces, set theory, LayerNorm, RMSNorm, penalized sampling, temperature-controlled stochastic sampling, top-k alternatives, sparse Transformers, attention sinks, Dropout and DropConnect, Xavier, MSRA, all-attention persistent memory, KV cache, cross-attention, momentum, minibatch, Kronecker delta, adaptive attention span, weights binarization, grouped query attention and multiquery attention, fused MLP, inner cross-attention and inner self-attention, RoPE, sine, and learned position embedding, GLU, GELU, Swish, LSTM, RNN, SoftMax, sigmoid, Boltzmann, logits, BPE, dynamic weights, probability density, tokenizer, bytepair, causal masking, autoregression, autoassociation, PCA, ICA, GMM, tensor contraction, Hadamard product, logit, FMA, GEMM fast matrix multiplication, Hilbert's 13th and 10th problem, DP, LP, HJB, quantum mechanics, and general relativity just to do the work mentioned.

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