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.
The stack of exponents never ends, so ticking folders one by one can never finish. Instead the proof folds the map: if exponent four falls and every odd prime falls, everything else is covered by them. The drawer for three is already shut, and the big-prime folders travel with the Frey-package crew.
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 & attributionInfinitely many folders. One suspiciously small filing cabinet.
After the special exponent 3, we organize the remaining exponents. Rewriting a power as a power of a power lets a hypothetical solution lead to a smaller collection of cases.
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 → proofThe tower of folders is the infinitely many exponents. Finishing an endless checklist cannot establish the goal.
All exponentsFermatLastTheoremStory → proofFolding the map is a reduction: exponent four and odd primes suffice to cover the original claim.
Reduce to odd primesFermatLastTheorem.of_odd_primesStory → proofThe closed drawer is the resolved exponent-three case. The case split separates it from primes at least five.
Separate the small casesby_cases hp5 : 5 ≤ pStory → proofThe small satchel carries the remaining large-prime cases into the Frey-package proof. Reduction keeps every case covered.
Follow the large-prime proofFreyPackage.fermatLastTheoremFor_of_five_leThe stack of exponents never ends, so ticking folders one by one can never finish. Instead the proof folds the map: if exponent four falls and every odd prime falls, everything else is covered by them. The drawer for three is already shut, and the big-prime folders travel with the Frey-package crew.
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…
Too many suspects
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 →