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 overall reduction sorts exponents first. Composite exponents fold onto prime ones. Primes at least five travel with a Frey package — the subject of the following chapters. The case p = 3 is discharged by fermatLastTheoremThree, which the library proves with Euler’s descent: cubes modulo nine handle the elementary case, and the deeper case descends inside the Eisenstein integers on the multiplicity of 1 − ζ₃.
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 & attributionThe one small exponent that earned its own detective folder.
The first chapter stated a claim for every exponent ≥ 3. This chapter handles n = 3 separately. Like the stair story, one case and a rule for other cases have different jobs; this one case alone is not the whole theorem.
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 full solution opens by narrowing all remaining work to odd primes.
The whole case lands heretheorem solution : FermatLastTheoremStory → proofExponents five and above depart with the parcel; the case of three stays on the desk.
The parcel route for p ≥ 5exact FreyPackage.fermatLastTheoremFor_of_five_le p pp hp5Story → proofinterval_cases enumerates candidates inside proved bounds: a finite check, not a search.
Bounded enumerationinterval_cases pStory → proofOne import line carries a centuries-old descent into the modern proof.
Euler’s descent, importedfermatLastTheoremThreeThe overall reduction sorts exponents first. Composite exponents fold onto prime ones. Primes at least five travel with a Frey package — the subject of the following chapters. The case p = 3 is discharged by fermatLastTheoremThree, which the library proves with Euler’s descent: cubes modulo nine handle the elementary case, and the deeper case descends inside the Eisenstein integers on the multiplicity of 1 − ζ₃.
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 case of three
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 →