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feat: add von Neumann double commutant theorem eval problem - #11

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eval/vonneumann-double-commutant
Apr 18, 2026
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feat: add von Neumann double commutant theorem eval problem#11
kim-em merged 3 commits into
mainfrom
eval/vonneumann-double-commutant

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@kim-em kim-em commented Apr 16, 2026

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Summary

Adds an eval problem for von Neumann's double commutant theorem.

For a unital *-subalgebra S of H →L[ℂ] H on a complex Hilbert space H, the statement asserts the TFAE of:

  1. S equals its double commutant (Set.centralizer (Set.centralizer S) = S)
  2. S is closed in the weak operator topology
  3. S is closed in the strong operator topology (in Mathlib: the topology of pointwise convergence on continuous linear maps)

Mathlib already has VonNeumannAlgebra, StarSubalgebra, Set.centralizer, the WOT type copy (ContinuousLinearMapWOT / H →WOT[ℂ] H), and the SOT type copy (PointwiseConvergenceCLM / H →Lₚₜ[ℂ] H, documented as "sometimes also called the strong operator topology"). The statement pushes the carrier through each canonical inclusion and asserts closedness in the type copy — the ergonomic cost of WOT/SOT being irreducible type copies rather than topologies on H →L[ℂ] H itself.

Test plan

  • lake build FormalMathEval.Analysis.VonNeumannDoubleCommutant
  • lake exe lean-eval validate-manifest
  • lake exe lean-eval check-problem-build
  • lake exe lean-eval generate --problem vonNeumann_doubleCommutant_tfae
  • lake exe lean-eval check-generated-builds --problem vonNeumann_doubleCommutant_tfae

🤖 Generated with Claude Code

States the classical DCT for a unital *-subalgebra of B(H): equality
with the double commutant is equivalent to WOT-closedness and to
SOT-closedness (the latter appearing in Mathlib as the topology of
pointwise convergence on continuous linear maps).

WOT and SOT live on irreducible type copies of `H →L[ℂ] H`, so each
closure condition is stated on the image of the carrier under the
canonical inclusion into the corresponding type copy.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
@kim-em
kim-em force-pushed the eval/vonneumann-double-commutant branch from 8526d29 to 2588e03 Compare April 17, 2026 11:01
kim-em and others added 2 commits April 17, 2026 21:22
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
@kim-em
kim-em merged commit 97fbfe2 into main Apr 18, 2026
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@kim-em
kim-em deleted the eval/vonneumann-double-commutant branch April 18, 2026 00:23
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