From cdf8cc5e99c3c7f844f6fd874223622d9ecf545e Mon Sep 17 00:00:00 2001 From: GTBarkley Date: Mon, 12 Jun 2023 18:02:03 +0000 Subject: [PATCH] stated some equivalences for bounding krull dim --- CommAlg/grant.lean | 21 +++++++-------------- 1 file changed, 7 insertions(+), 14 deletions(-) diff --git a/CommAlg/grant.lean b/CommAlg/grant.lean index 8586fa3..2f3c634 100644 --- a/CommAlg/grant.lean +++ b/CommAlg/grant.lean @@ -2,6 +2,7 @@ import Mathlib.Order.KrullDimension import Mathlib.Order.JordanHolder import Mathlib.AlgebraicGeometry.PrimeSpectrum.Basic import Mathlib.Order.Height +import CommAlg.krull #check (p q : PrimeSpectrum _) → (p ≤ q) @@ -39,22 +40,14 @@ lemma twoHeights : s ≠ ∅ → (some (Set.chainHeight s) : WithBot (WithTop -- norm_cast sorry -namespace Ideal -noncomputable def krullDim (R : Type _) [CommRing R] := - Set.chainHeight (Set.univ : Set (PrimeSpectrum R)) - -def krullDimGE (R : Type _) [CommRing R] (n : ℕ) := - ∃ c : List (PrimeSpectrum R), c.Chain' (· < ·) ∧ c.length = n + 1 - -def krullDimLE (R : Type _) [CommRing R] (n : ℕ) := - ∀ c : List (PrimeSpectrum R), c.Chain' (· < ·) → c.length ≤ n + 1 - -end Ideal - open Ideal -lemma krullDim_le (R : Type _) [CommRing R] : krullDimLE R n ↔ Ideal.krullDim R ≤ n := sorry -lemma krullDim_ge (R : Type _) [CommRing R] : krullDimGE R n ↔ Ideal.krullDim R ≥ n := sorry +lemma krullDim_le_iff' (R : Type _) [CommRing R] : + Ideal.krullDim R ≤ n ↔ (∀ c : List (PrimeSpectrum R), c.Chain' (· < ·) → c.length ≤ n + 1) := by + sorry + +lemma krullDim_ge_iff' (R : Type _) [CommRing R] : + Ideal.krullDim R ≥ n ↔ ∃ c : List (PrimeSpectrum R), c.Chain' (· < ·) ∧ c.length = n + 1 := sorry -- #check ((4 : ℕ∞) : WithBot (WithTop ℕ))