MLP — the grokking vehicle
5,51828→128→14 MLP trained on all 182 off-diagonal (a+b) mod 14 pairs with AdamW lr=1e-3. It memorizes by epoch ~1000; held-out accuracy on the 14 diagonal pairs (a == b, never trained) snaps to 1.0 at epoch 9000 with wd=1.0 and epoch 25000 with wd=0.3 — the classic grokking transition, reproduced honestly at full 30k epochs.
SimpleCNN — 2D structure
114Conv2D(im2col forward, col2im backward) → ReLU → MaxPool → Flatten → Linear on flattened-NCHW input. Fit gate: stripes-task train accuracy 0.978 > 0.9, held-out 0.80.
MiniGPT — attention that pays rent
26,182Embedding + learned positional table + 2 TransformerBlocks (post-LN, causal MHA) + vocab head via seq_linear. Fits a deterministic period-8 char grammar over vocab 6: train 97.7%, held-out 94.5% — through real attention, not a lookup shortcut.