Skip to content

feat: add Koszul formula eval problem#299

Open
kim-em wants to merge 1 commit into
mainfrom
eval/koszul-formula
Open

feat: add Koszul formula eval problem#299
kim-em wants to merge 1 commit into
mainfrom
eval/koszul-formula

Conversation

@kim-em
Copy link
Copy Markdown
Collaborator

@kim-em kim-em commented May 23, 2026

This PR adds the Koszul formula as a new lean-eval challenge problem — §38 of Oliver Knill's Some Fundamental Theorems in Mathematics (an additional statement; the boxed main theorem is the Levi-Civita fundamental theorem, submitted as a companion PR).

For any smooth torsion-free metric-compatible covariant derivative cov on the tangent bundle of a Riemannian manifold:

2 ⟨∇_X Y, Z⟩ = X·⟨Y,Z⟩ + Y·⟨X,Z⟩ − Z·⟨X,Y⟩ − ⟨X,[Y,Z]⟩ − ⟨Y,[X,Z]⟩ + ⟨Z,[X,Y]⟩

This is the identity that forces uniqueness of the Levi-Civita connection.

mathlib has the covariant-derivative / Riemannian-bundle / Lie-bracket machinery but no metric-compatibility predicate and no Koszul formula. The Challenge ships one auxiliary definition (IsMetricCompatible).

🤖 Prepared with Claude Code

§38 of Knill's "Some Fundamental Theorems in Mathematics" (additional
statement; the boxed main theorem is Levi-Civita). For any smooth
torsion-free metric-compatible covariant derivative, 2⟨∇_X Y, Z⟩ is the
cyclic sum of directional derivatives minus the Lie-bracket cyclic sum
— the identity that forces uniqueness of Levi-Civita. Mathlib has the
covariant-derivative / Lie-bracket machinery but neither
metric-compatibility nor Koszul. The Challenge ships IsMetricCompatible.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

None yet

Projects

None yet

Development

Successfully merging this pull request may close these issues.

1 participant