Lessons

• Lesson 01 — Five numbers: the map — You have islands. This lesson gives you the map they sit in — and it fits in five numbers.
• Lesson 02 — The Atlantic ladder — Your map is European, so anything American has nowhere to sit. Here is the second row of five — plus the test that resolves the coin-flips near a hinge.
• Lesson 03 — Six engines, drawn — You applied the mechanism test and still misread three. The fix isn't more history — it's seeing each engine as a shape: where the surplus is, how it turns into force, and who ends up fighting.