What you will be able to see

The step below is Lesson 3’s home still. The valley is Lesson 6’s ravine. Both numbers are numpy-locked. Unit 0 teaches that language; P1–P5 are live in Learn (quizzes stay on paper). Lessons 1–22 are all live — the Optimisation track spine is complete.

Start at w = 4, height 8. Home eta 0.5 lands at w = 2, height 8 → 2. Eta 2 bounces 4 and −4.

Live step: w 4.00 → 2.00, height 8.00 → 2.00. Home step. Height 8 → 2.

Start at (1, 0.1), height 1. Slope (1, 10). Conditioning κ = 100. The 3D y-axis is stretched so the trench is visible; height is true f.

Honest η = 1/κ = 0.01 moves to (0.99, 0.00). Lesson 3’s η = 0.5 on this valley flies to (0.5, -4.9), height 1200.6. One learning rate cannot serve both axes. That is why Adam exists.

Locked still f = ½(x² + 100y²) · home 1, 0.1

The path

The language of the hill → landscape → unconstrained walking → the modern trainer → walls → prices → product constraints.

A lesson links once its video, notes, quiz, and interactive ship. Lesson 1 is linked; the rest of the titles below stay unlinked until their media ships.

Live

Unit P. The language of the hill

Lists, slopes, uphill arrows, ravine algebra, and a chord test — the words the 22-lesson walk will use without stopping to define them.

  1. Lists That Agree
  2. The Price of a Nudge
  3. The Uphill List
  4. Stiff Knobs and Ravines
  5. One Bowl, a Chain, Two Wells

Live

Unit A. The landscape

Live

Unit B. Unconstrained walking

Ravines, noisy batches, memory, and a local bowl. Same downhill, better compasses.

  1. Ravines and Conditioning
  2. Line Search Trusts the Slope
  3. A Batch Is a Noisy Compass
  4. Momentum Remembers the Slope
  5. Newton Fits a Local Bowl

Live

Unit C. The modern trainer

Per-coordinate trust, AdamW as the LLM recipe, saddles that look like arrival.

  1. Adaptive Steps Per Coordinate
  2. Adam, AdamW, and the LLM Recipe
  3. Saddles Are Critical and Flat

Live

Unit D. Walls

A feasible set is a wall. Project. Or hide the nonsmooth piece in a prox.

  1. A Feasible Set Is a Wall
  2. Projected Gradient Stays Inside
  3. Proximal Maps Hide the Nonsmooth Piece

Live

Unit E. Prices

A multiplier is a price. KKT is stationarity on the wall. The gap certifies arrival.

  1. Multipliers Are Prices
  2. KKT Says Stationary on the Wall
  3. Duality Gap Certifies Arrival

Live

Unit F. Product constraints

KL balls, LoRA subspaces, and barriers. The constraints products actually ship.

  1. Trust Regions and KL Balls
  2. LoRA Is a Subspace Constraint
  3. Barriers Turn Walls Into Bowls