Documentation

FLT.Slop.DimensionTheorem

Dimension theorem for Noetherian local rings #

Umbrella module for the FLT.Slop.DimensionTheorem library. See FLT/Slop/DimensionTheorem/README.md for an overview and sources.

The main result is DimensionTheorem.dimension_theorem (FLT/Slop/DimensionTheorem/Main.lean): for a Noetherian local ring (R, 𝔪), the Krull dimension, the growth degree d(R) of the Hilbert–Samuel function n ↦ ℓ(R ⧸ 𝔪ⁿ), and the least number of generators δ(R) of an ideal of definition all agree (Atiyah–Macdonald, Thm. 11.14; Stacks Project, tag 00KQ).

File overview:

The formalization deliberately phrases the Hilbert–Samuel side in terms of polynomial growth (GrowthLE) rather than constructing the eventual Hilbert–Samuel polynomial. Mathlib has a separate Polynomial.hilbertPoly backend for rational functions of the form p / (1 - X)^d, but the graded module theorem producing such a rational Hilbert series (Hilbert–Serre) is not used here.