Fermat's Last Theorem

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In number theory, Fermat's Last Theorem (sometimes called Fermat's conjecture, especially in older texts) states that there are no positive integers a,b,c,na,b,c,n with n>2n>2 such that an+bn=cna^{n}+b^{n}=c^{n}. The cases n=1n=1 and n=2n=2 have been known since antiquity to have infinitely many solutions. The proposition was first stated as a theorem by Pierre de Fermat around 1637 in the margin of a copy of Arithmetica. Fermat added that he had a proof that was too large to fit in the margin. Although other statements claimed by Fermat without proof were subsequently proven by others and credited as theorems of Fermat (for example, Fermat's theorem on sums of two squares), Fermat's Last Theorem resisted proof, leading to doubt that Fermat ever had a correct proof. Consequently, the proposition became known as a conjecture rather than a theorem. After 358 years of effort by mathematicians, the first successful proof was released in 1994 by Andrew Wiles and formally published in 1995. It was described as a "stunning advance" in the citation for Wiles's Abel Prize award in 2016.

References

Progress summary

Refreshed
Open · solution reported

Fermat’s Last Theorem was rigorously proved in the 1990s, and no credible challenge to that proof has appeared.

Fermat proposed the assertion around 1637, claiming that no positive integers satisfy the equation for any exponent greater than two. Andrew Wiles announced a proof in 1993; after a flaw was found, Wiles and Richard Taylor repaired it, and the proof was published in 1995.

Known results

  • Fermat proved the fourth-power case by infinite descent, implying the case n=4n=4 (seventeenth century).
  • Wiles proved the semistable modularity theorem, which implied Fermat’s Last Theorem; Taylor–Wiles completed the repair in 1994, with publication in 1995.

August 2026 assessment

Cheng and McLarty’s new paper evaluates the depth and explanatory structure of Wiles’s proof; it presents no new proof, counterexample, or unresolved gap, and treats the theorem as established.

Current status (as of August 2026): The theorem is settled by the corrected Wiles–Taylor proof, published in 1995; no part of the original assertion remains open.

Sources

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