clopen.solutions

SP-04: generic failure of the smallest-absolute-multiplier rule

Recorded by the registry's curators from GitHub; the authors did not submit it here.

George Stepaniants

Complete original generic selection rule refuted: a nonempty open family of real 3×3 data matrices has invertibility, distinct squared singular values, a finite full stationary set, a unique least-absolute-multiplier pair and a strictly closer feasible matrix in the actual Frobenius norm.

Claims

LEAN VERIFIED OP-00119 — The smallest-multiplier rule for nearest unit-absolute-determinant matrices
Disproof · statement matched the canonical formalisation

Files and sources

Paper
OpenProblemsInNLA @ e375a6f, SP-04/lean/ ↗
Lean bundle
submissions/bundles/openproblemsinnla-sp-04-lean.tar.gz
Toolchain
leanprover/lean4:v4.33.1
Posted on GitHub
15 September 2026

Verification PASSED

Attempt
1
Toolchain
leanprover/lean4:v4.33.1
Auditor
v1 · modal
lake build
succeeded
Kernel replay
succeeded
Duration
0:03:09.616317

Declarations audited

DeclarationKindAxiomsUnused hypothesesCanonical
NLA.SP04.canonical_counterexample theorem · Prop propext, Classical.choice, Quot.sound none matched
RegistryProblems.Problem_OP_00119 definition propext, Classical.choice, Quot.sound none no canonical statement

NLA.SP04.canonical_counterexample

Not NLA.SP04.AllGenericSelectionRules

RegistryProblems.Problem_OP_00119

Prop

Build log

RegistryProblems: built against the registry's copy at 38ca23a44fc2b159a0c944d5c9af39a80eb601c2 rather than the pinned 545a5d18ad3917d52192c41ce172ec4b41945751. Statements are checked by content, not revision.
✔ [3680/3697] Built NLA.SP04.Definitions (7.3s)
✔ [3681/3697] Built NLA.SP04.Generic (6.8s)
✔ [3682/3697] Built NLA.SP04.SpectralIntervals (8.8s)
✔ [3683/3697] Built NLA.SP04.Orthogonal (6.1s)
✔ [3684/3697] Built NLA.SP04.MatrixStationary (7.2s)
✔ [3685/3697] Built NLA.SP04.SVD (6.9s)
⚠ [3686/3697] Built NLA.SP04.Certificates (11s)
warning: NLA/SP04/Certificates.lean:19:4: `Set.mem_setOf` has been deprecated: Use `Set.mem_ofPred` instead
info: NLA/SP04/Certificates.lean:25:0: 'NLA.SP04.scalar_numerical_bounds' depends on axioms: [propext, Classical.choice, Quot.sound]
✔ [3687/3697] Built NLA.SP04.Spectrum (6.0s)
✔ [3688/3697] Built NLA.SP04.ScalarRoots (8.0s)
⚠ [3689/3697] Built NLA.SP04.ScalarPositive (11s)
warning: NLA/SP04/ScalarPositive.lean:66:5: Variable name `hc` is not explicitly referenced.

Hint: The binding can be removed (if unused) or named `_` (if used implicitly). Alternatively, prefix the name with `_` to silence this warning:
  [apply] _hc

Note: This linter can be disabled with `set_option linter.unusedVariables false`
⚠ [3690/3697] Built NLA.SP04.Scalar (6.2s)
warning: NLA/SP04/Scalar.lean:154:27: try 'simp' instead of 'simpa'

Note: This linter can be disabled with `set_option linter.unnecessarySimpa false`
info: NLA/SP04/Scalar.lean:201:0: 'NLA.SP04.scalar_least_unique' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/SP04/Scalar.lean:202:0: 'NLA.SP04.selected_parameter_exists' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/SP04/Scalar.lean:203:0: 'NLA.SP04.scalar_distance_improves' depends on axioms: [propext, Classical.choice, Quot.sound]
ℹ [3691/3697] Built NLA.SP04.Diagonal (4.4s)
info: NLA/SP04/Diagonal.lean:50:0: 'NLA.SP04.selected_unique_least' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/SP04/Diagonal.lean:51:0: 'NLA.SP04.diagonal_counterexample_full' depends on axioms: [propext, Classical.choice, Quot.sound]
⚠ [3692/3697] Built NLA.SP04.Finiteness (28s)
warning: NLA/SP04/Finiteness.lean:109:22: Used `tac1 <;> tac2` where `(tac1; tac2)` would suffice

Note: This linter can be disabled with `set_option linter.unnecessarySeqFocus false`
info: NLA/SP04/Finiteness.lean:188:0: 'NLA.SP04.stationaryEliminant_at_zero' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/SP04/Finiteness.lean:189:0: 'NLA.SP04.scalar_stationary_eliminant' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/SP04/Finiteness.lean:190:0: 'NLA.SP04.diagonal_stationary_finite' depends on axioms: [propext, Classical.choice, Quot.sound]
ℹ [3693/3697] Built NLA.SP04.Witness (4.7s)
info: NLA/SP04/Witness.lean:97:0: 'NLA.SP04.uniqueLeastStationary_orthogonal_iff' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/SP04/Witness.lean:98:0: 'NLA.SP04.stationaryPairs_orthogonal_eq' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/SP04/Witness.lean:99:0: 'NLA.SP04.stationaryPairs_finite_orthogonal_iff' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/SP04/Witness.lean:100:0: 'NLA.SP04.selectionFails_of_admissible_svd' depends on axioms: [propext, Classical.choice, Quot.sound]
ℹ [3694/3697] Built NLA.SP04.Proof (4.4s)
info: NLA/SP04/Proof.lean:92:0: 'NLA.SP04.numerical_bounds' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/SP04/Proof.lean:94:0: 'NLA.SP04.diagonal_stationary_iff' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/SP04/Proof.lean:96:0: 'NLA.SP04.diagonal_counterexample' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/SP04/Proof.lean:98:0: 'NLA.SP04.diagonal_finite' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/SP04/Proof.lean:100:0: 'NLA.SP04.orthogonal_transport' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/SP04/Proof.lean:102:0: 'NLA.SP04.spectral_family' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/SP04/Proof.lean:104:0: 'NLA.SP04.regular_svd' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/SP04/Proof.lean:106:0: 'NLA.SP04.open_family_counterexamples' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/SP04/Proof.lean:108:0: 'NLA.SP04.algebraic_avoidance' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/SP04/Proof.lean:110:0: 'NLA.SP04.generic_counterexamples' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/SP04/Proof.lean:112:0: 'NLA.SP04.canonical_counterexample' depends on axioms: [propext, Classical.choice, Quot.sound]
✔ [3695/3697] Built Solution (4.4s)
✔ [3696/3697] Built RegistryRecord (4.2s)
Build completed successfully (3697 jobs).