comm_alg/README.md
2023-06-10 16:09:51 -07:00

2.1 KiB
Raw Permalink Blame History

Commutative algebra in Lean

Welcome to the repository for adding definitions and theorems related to Krull dimension and Hilbert polynomials to mathlib.

We start the commutative algebra project with a list of important definitions and theorems and go from there.

Feel free to add, modify, and expand this file. Below are starting points for the project:

  • Definitions of an ideal, prime ideal, and maximal ideal:
def Mathlib.RingTheory.Ideal.Basic.Ideal (R : Type u) [Semiring R] := Submodule R R
class Mathlib.RingTheory.Ideal.Basic.IsPrime (I : Ideal α) : Prop
class IsMaximal (I : Ideal α) : Prop
  • Definition of a Spec of a ring: Mathlib.AlgebraicGeometry.PrimeSpectrum.Basic.PrimeSpectrum

  • Definition of a Noetherian and Artinian rings:

class Mathlib.RingTheory.Noetherian.IsNoetherian (R M) [Semiring R] [AddCommMonoid M] [Module R M] : Prop
class Mathlib.RingTheory.Artinian.IsArtinian (R M) [Semiring R] [AddCommMonoid M] [Module R M] : Prop
  • Definition of a polynomial ring: Mathlib.RingTheory.Polynomial.Basic

  • Definitions of a local ring and quotient ring: Mathlib.RingTheory.Ideal.Quotient.?

class Mathlib.RingTheory.Ideal.LocalRing.LocalRing (R : Type u) [Semiring R] extends Nontrivial R : Prop
  • Definition of the chain of prime ideals and the length of these chains

  • Definition of the Krull dimension (supremum of the lengh of chain of prime ideal): Mathlib.Order.KrullDimension.krullDim

  • Krull dimension of a module

  • Definition of the height of prime ideal (dimension of A_p): Mathlib.Order.KrullDimension.height

Give Examples of each of the above cases for a particular instances of ring

Theorem 0: Hilbert Basis Theorem:

theorem Mathlib.RingTheory.Polynomial.Basic.Polynomial.isNoetherianRing [inst : IsNoetherianRing R] : IsNoetherianRing R[X]

Theorem 1: If A is a nonzero ring, then dim A[t] >= dim A +1

Theorem 2: If A is a nonzero noetherian ring, then dim A[t] = dim A + 1

Theorem 3: If A is nonzero ring then dim A_p + dim A/p <= dim A

Lemma 0: A ring is artinian iff it is noetherian of dimension 0.

Definition of a graded module