The Lessons

Short interactive lessons in machine learning and the mathematics under it. One idea each, worked out on a dead-simple example before it is given its name, with room to breathe between steps.

• A bit is one good question

  Entropy, cross-entropy, and KL divergence, worked out at a café counter with yes-or-no questions.

  October 2026
• A matrix is a mix of its columns

  Six honest ways to read a matrix multiplication, worked out at a fruit stand.

  September 2026

Each lesson opens as its own page, with its own typography. Written with an AI co-author while working through the ARENA curriculum; the first reader is always me, a week earlier.