
The book begins with an overview of the complete proof, followed by several introductory chapters surveying the basic theory of elliptic curves, modular functions, modular curves, Galois cohomology, and finite group schemes. Representation theory, which lies at the core of Wiles' proof, is dealt with in a chapter on automorphic representations and the Langlands-Tunnell theorem, and this is followed by in-depth discussions of Serre's conjectures, Galois deformations, universal deformation rings, Hecke algebras, complete intersections, and more, as the reader is led step-by-step through Wiles' proof. In recognition of the historical significance of Fermat's Last Theorem, the volume concludes by looking both forward and backward in time, reflecting on the history of the problem, while placing Wiles' theorem into a more general Diophantine context suggesting future applications. Students and professional mathematicians alike will find this volume to be an indispensable resource for mastering the epoch-making proof of Fermat's Last Theorem.
When I was in grad school, I remember reading a comment from someone talking about looking at her roommate's materials for her PhD in English and realizing that while what she had was comprehensible to her even if she didn't necessarily understand any of it, her own materials for her math PhD were completely unintelligible to outsiders.
His proof was exceptionally understated when it was presented. In 1993, he gave lectures on his proof of the Taniyama-Shimura-Weil conjecture (the modularity theorem), which was the bulk of the machinery of the proof (the modularity theorem for semistable elliptic curves implies Fermat’s Last Theorem). He simply stated at the end of the lecture that his proof also happened to imply Fermat’s Last Theorem.
Up until Wiles did it, much of the mathematical community at the time didn’t think Fermat’s Last Theorem was “accessible” to prove with contemporary techniques. Incidentally, Fermat himself wrote that he had a “truly marvelous proof” of the theorem in the margin next to it in one of his books, but which he couldn’t write down becuase the margin was apparently too small to contain it. There’s pretty broad skepticism Fermat actually had a proof however, considering that most of Wiles’ (very long, and very complex) proof borrowed results from large swaths of mathematics not developed until the 20th century.
If anyone is interested in trying to learn how the proof works at the formal level, the book Modular Forms and Fermat’s Last Theorem by Cornell, Silverman and Stevens provides a rigorous presentation that builds up the necessary mathematics to understand the entire thing. It’s easily a graduate-level textbook, but it’s probably accessible (with effort) to anyone who has worked through undergraduate abstract algebra (up to finite fields and Galois theory) and number theory (up to elliptic curves).