2 research outputs found
A formal proof of Hensel's lemma over the p-adic integers
The field of -adic numbers and the ring of -adic
integers are essential constructions of modern number theory.
Hensel's lemma, described by Gouv\^ea as the "most important algebraic property
of the -adic numbers," shows the existence of roots of polynomials over
provided an initial seed point. The theorem can be proved for
the -adics with significantly weaker hypotheses than for general rings. We
construct and in the Lean proof assistant, with
various associated algebraic properties, and formally prove a strong form of
Hensel's lemma. The proof lies at the intersection of algebraic and analytic
reasoning and demonstrates how the Lean mathematical library handles such a
heterogeneous topic.Comment: CPP 201
A formal proof of Hensel's lemma over the p-adic integers
The field of p-adic numbers p and the ring of p-adic integers p are essential constructions of modern number theory. Hensels lemma, described by Gouva as the most important algebraic property of the p-adic numbers, shows the existence of roots of polynomials over p provided an initial seed point. The theorem can be proved for the p-adics with significantly weaker hypotheses than for general rings. We construct p and p in the Lean proof assistant, with various associated algebraic properties, and formally prove a strong form of Hensels lemma. The proof lies at the intersection of algebraic and analytic reasoning and demonstrates how the Lean mathematical library handles such a heterogeneous topic