Merge pull request #35 from GTBarkley/grant

proved krullDim_nonneg_of_nontrivial
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GTBarkley 2023-06-12 22:12:13 -07:00 committed by GitHub
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@ -73,7 +73,7 @@ height 𝔭 > n ↔ ∃ c : List (PrimeSpectrum R), c.Chain' (· < ·) ∧ (∀
show ((↑(n + 1):ℕ∞) ≤ _) ↔ ∃c, _ ∧ _ ∧ ((_ : WithTop ) = (_:ℕ∞))
rw [{J | J < 𝔭}.le_chainHeight_iff]
show (∃ c, (List.Chain' _ c ∧ ∀𝔮, 𝔮 ∈ c → 𝔮 < 𝔭) ∧ _) ↔ _
have h := fun (c : List (PrimeSpectrum R)) => (@WithTop.coe_eq_coe _ (List.length c) n)
-- have h := fun (c : List (PrimeSpectrum R)) => (@WithTop.coe_eq_coe _ (List.length c) n)
constructor <;> rintro ⟨c, hc⟩ <;> use c --<;> tauto--<;> exact ⟨hc.1, by tauto⟩
. --rw [and_assoc]
-- show _ ∧ _ ∧ _
@ -83,6 +83,11 @@ height 𝔭 > n ↔ ∃ c : List (PrimeSpectrum R), c.Chain' (· < ·) ∧ (∀
norm_cast at hc
tauto
lemma krullDim_nonneg_of_nontrivial [Nontrivial R] : ∃ n : ℕ∞, Ideal.krullDim R = n := by
have h := dim_eq_bot_iff.not.mpr (not_subsingleton R)
lift (Ideal.krullDim R) to ℕ∞ using h with k
use k
lemma krullDim_le_iff' (R : Type _) [CommRing R] {n : WithBot ℕ∞} :
Ideal.krullDim R ≤ n ↔ (∀ c : List (PrimeSpectrum R), c.Chain' (· < ·) → c.length ≤ n + 1) := by
sorry
@ -90,6 +95,8 @@ lemma krullDim_le_iff' (R : Type _) [CommRing R] {n : WithBot ℕ∞} :
lemma krullDim_ge_iff' (R : Type _) [CommRing R] {n : WithBot ℕ∞} :
Ideal.krullDim R ≥ n ↔ ∃ c : List (PrimeSpectrum R), c.Chain' (· < ·) ∧ c.length = n + 1 := sorry
#check (sorry : False)
#check (sorryAx)
#check (4 : WithBot ℕ∞)