Follow the story. Try a proof. Let curiosity choose how deep you go.
Walk in through the manga: seventeen chapters, sixty-four pocket pebbles, zero required formulas. The Lean source stays behind glass until you ask for it.
Straight to the mathematicsBegin at the proof map — thousands of named theorems — then climb the full ladder from clock inverses to R = T. The story keeps telling itself beside you; it will keep you honest.
Made for company: one reader who loves math and one who does not — one sofa. Whatever each of you finds carries over to the tea salon.
Seventeen chapters, one extraordinary argument. One small discovery is enough for today.
Pip’s rule: mistakes are clues. Every chapter is open, and every question allows another try.
Powers, smaller problems, and a suspicious parcel.
Search the local catalogue in English or Japanese. Major landmarks have Japanese titles. Open the full original proof on GitHub for the complete context.
A cake order stands for the equation: three towers of heights a ^ n, b ^ n and c ^ n must come out exactly equal. One square-cake order does succeed, because exponent two is outside the theorem range. The job is to show that no order succeeds once the exponent is three or more, with no empty trays and positive heights throughout.
Annotated original · not a live Lean statePoint to a story clue or a highlighted term to connect the two.
Try this logical move →Source: anthropics/fermats-last-theorem @ aa2d8b3. Upstream reports verification; this reader has not independently rebuilt the project. Manga explanations are not formal proofs.
Source license & attributionPip orders three whole-number cakes. The bakery has questions.
The square story explained a². Here powers become a question: could three positive whole numbers satisfy aⁿ + bⁿ = cⁿ when n ≥ 3? First understand the claim; the contradiction comes later.
These links explain the reading route. A story analogy is not a proof of this theorem.
Already familiar? Keep reading. Otherwise, open a word or follow the prerequisites from the beginning.
Story → proofA cake order stands for numbers satisfying the equation. The successful square order is outside the theorem’s exponent range.
The impossible equationa ^ n + b ^ n ≠ c ^ nStory → proofChanging the cakes to cubes introduces the exponent condition: the same n must be at least three in all three powers.
Exponent at least threehn : 3 ≤ nStory → proofPip’s empty tray is zero. Mika’s refusal is the positivity condition; b and c have matching conditions too.
No empty trayha : 0 < aStory → proofThe case envelope is a promise about every permitted order. The final line invokes the theorem that supports that promise.
The theorem behind the promiseFLT.fermatLastTheoremA cake order stands for the equation: three towers of heights a ^ n, b ^ n and c ^ n must come out exactly equal. One square-cake order does succeed, because exponent two is outside the theorem range. The job is to show that no order succeeds once the exponent is three or more, with no empty trays and positive heights throughout.
The story and source are readable here. Enable JavaScript to edit proofs, try quizzes, and explore the interactive map.
Short scenes. Real logical goals. A pigeon who is very invested in your success.
Opening the casebook…
The impossible order
Start with the cake-scale story. You only need to read one small piece at a time. If you are in the Fermat story, start with Story depth, then the words listed before the chapter.
You do not need to know Lean, symbols or university mathematics to begin. Definitions come first in the small stories.
Look at the small example before the general formula. Ask what changed and what stayed the same.
Close this panel to return to the exact place you were reading. These are prepared hints for this page.
Start with the first small story →