Skip to content

feat(RingTheory/DedekindDomain/Ideal/Lemmas): add nontrivial_heightOneSpectrum#35533

Open
mariainesdff wants to merge 4 commits intomasterfrom
nontrivial_heightOneSpectrum
Open

feat(RingTheory/DedekindDomain/Ideal/Lemmas): add nontrivial_heightOneSpectrum#35533
mariainesdff wants to merge 4 commits intomasterfrom
nontrivial_heightOneSpectrum

Conversation

@mariainesdff
Copy link
Copy Markdown
Contributor

Co-authored by: @xgenereux.


Open in Gitpod

@mariainesdff mariainesdff added the t-ring-theory Ring theory label Feb 19, 2026
@github-actions
Copy link
Copy Markdown

github-actions bot commented Feb 19, 2026

PR summary 4e2c52aae1

Import changes for modified files

No significant changes to the import graph

Import changes for all files
Files Import difference

Declarations diff

+ Algebra.IsIntegral.nontrivial_heightOneSpectrum

You can run this locally as follows
## summary with just the declaration names:
./scripts/pr_summary/declarations_diff.sh <optional_commit>

## more verbose report:
./scripts/pr_summary/declarations_diff.sh long <optional_commit>

The doc-module for scripts/pr_summary/declarations_diff.sh contains some details about this script.


No changes to technical debt.

You can run this locally as

./scripts/reporting/technical-debt-metrics.sh pr_summary
  • The relative value is the weighted sum of the differences with weight given by the inverse of the current value of the statistic.
  • The absolute value is the relative value divided by the total sum of the inverses of the current values (i.e. the weighted average of the differences).

@tb65536 tb65536 added the awaiting-author A reviewer has asked the author a question or requested changes. label Feb 20, 2026
@mariainesdff mariainesdff removed the awaiting-author A reviewer has asked the author a question or requested changes. label Feb 23, 2026
Copy link
Copy Markdown
Member

@erdOne erdOne left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I think

open IsDedekindDomain in
lemma Algebra.IsIntegral.nontrivial_heightOneSpectrum [IsDomain A] [Algebra R A]
    [FaithfulSMul R A] [Algebra.IsIntegral R A] [Nontrivial (HeightOneSpectrum R)] :
    Nontrivial (HeightOneSpectrum A) := by
  have := (FaithfulSMul.algebraMap_injective R A).isDomain
  let f (p : HeightOneSpectrum A) : HeightOneSpectrum R :=
    ⟨p.asIdeal.under R, inferInstance, mt Ideal.eq_bot_of_comap_eq_bot p.ne_bot⟩
  have : Function.Surjective f := fun ⟨p, _, hp⟩ ↦ by
    obtain ⟨P, hP, rfl⟩ := p.exists_ideal_over_prime_of_isIntegral_of_isDomain (S := A) (by simp)
    exact ⟨⟨P, hP, by aesop⟩, rfl⟩
  exact this.nontrivial

is a better proof and I am on the fence about having the subjectivity as its own separate lemma or not.

@erdOne erdOne added the awaiting-author A reviewer has asked the author a question or requested changes. label Feb 28, 2026
@mariainesdff
Copy link
Copy Markdown
Contributor Author

I think
is a better proof and I am on the fence about having the subjectivity as its own separate lemma or not.

I have switched to this proof.

@mariainesdff mariainesdff removed the awaiting-author A reviewer has asked the author a question or requested changes. label Mar 3, 2026
Comment on lines +1068 to +1069
let f (p : HeightOneSpectrum A) : HeightOneSpectrum R :=
⟨p.asIdeal.under R, inferInstance, mt Ideal.eq_bot_of_comap_eq_bot p.ne_bot⟩
Copy link
Copy Markdown
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Should this be a separate definition? It's strange we can't express primes below in the height one spectrum language.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

t-ring-theory Ring theory

Projects

None yet

Development

Successfully merging this pull request may close these issues.

6 participants