[LAB_RUNG_0]
FOUNDATIONS

Autodiff stops being magic when you build it once.

Rung 0 proves the base loop: represent data as arrays, compute a loss, get gradients, update parameters, then use JAX transformations to compile and batch that same idea.

Status
Code proof added
Runtime
Local CPU JAX
Next
Publish builder explanation

// MEASURED_PROOF

What ran

01

Micro-autodiff

finite diff match

Reverse-mode chain rule implemented from scratch for tanh(a*b + c).

02

Tiny JAX training

0.429063 -> 0.192692 loss

A small MLP fits a noisy sine curve with explicit SGD over a parameter pytree.

03

jit + vmap

218.26x CPU speedup

The jitted fixed-shape training step is benchmarked after excluding compile time.

// FILE_MAP

The proof is inspectable.

labs/00-foundations/GUIDE.mdtracked
labs/00-foundations/micro_autodiff.pytracked
labs/00-foundations/tiny_train.pytracked
labs/00-foundations/tiny_train_fast.pytracked
labs/00-foundations/RESULTS.mdtracked
tests/test_rung0_foundations.pytracked