bibkey: kitware2026rectangular authors: Jon Crall, Claude Fable 5, Claude Opus 4.8, GPT-5.6 Thinking, and GPT-5.6 High year: 2026 title: Formal rectangular singular-value variational bounds doi: null url: https://github.com/AIQ-Kitware/aiq-dkps-formalization/tree/64e234954217f3ca907ac980c8cbde2900109a66/ForTauCeti/Analysis/InnerProductSpace claim: Ky Fan variational bounds for finite rectangular linear maps follow from singular-value and polar-decomposition constructions. strata_touched:
- D5/S3/Quantum/Entanglement/FiniteSectorRectangularVariational license: Apache-2.0 triage: anchor
Rectangular singular-value variational bounds
The pinned source contains KyFan, PositiveSqrt,
SelfAdjointFunctionalCalculus, Polar/Decomposition,
RectangularSingularValues, ZeroExtension, and CourantFischer Lean
modules under ForTauCeti/Analysis/InnerProductSpace. The local rectangular
variational bound selects and adapts these arguments to the repository’s
pinned Lean and Mathlib interfaces. It does not attribute the finite-sector
channel optimum to this source.
The source headers identify the contributors above. The copyright, exact
revision, modifications, and full Apache-2.0 license text are retained in
docs/reports/licenses/finite-sector-channel-third-party.md. Retire the port
when this repository’s pinned Mathlib supplies equivalent declarations.
Verified locator
The pinned source is
https://github.com/AIQ-Kitware/aiq-dkps-formalization/tree/64e234954217f3ca907ac980c8cbde2900109a66/ForTauCeti/Analysis/InnerProductSpace.
The KyFan, PositiveSqrt, SelfAdjointFunctionalCalculus,
Polar/Decomposition, RectangularSingularValues, ZeroExtension, and
CourantFischer modules in that directory supply the rectangular
singular-value and variational arguments cited here.