clopen.solutions

IE-19: negative resolution of the sharp inverse norm conjecture

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

George Stepaniants

Proves an admissible real symmetric order-three counterexample using actual matrix inverses and the maximum absolute row-sum norm, then refutes the complete original universal conjecture including its equality clause.

Claims

LEAN VERIFIED OP-00083 — Sharp inverse norm bound from upper bounds on matrix entries
Disproof · statement matched the canonical formalisation

Files and sources

Paper
OpenProblemsInNLA @ e375a6f, IE-19/lean/ ↗
Lean bundle
submissions/bundles/openproblemsinnla-ie-19-lean.tar.gz
Toolchain
leanprover/lean4:v4.33.1
Posted on GitHub
12 September 2026

Verification PASSED

Attempt
1
Toolchain
leanprover/lean4:v4.33.1
Auditor
v1 · modal
lake build
succeeded
Kernel replay
succeeded
Duration
0:02:39.818523

Declarations audited

DeclarationKindAxiomsUnused hypothesesCanonical
NLA.IE19.not_sharpConjecture theorem · Prop propext, Classical.choice, Quot.sound none matched
RegistryProblems.Problem_OP_00083 definition propext, Classical.choice, Quot.sound none no canonical statement

NLA.IE19.not_sharpConjecture

Not NLA.IE19.SharpConjecture

RegistryProblems.Problem_OP_00083

Prop

Build log

RegistryProblems: built against the registry's copy at 38ca23a44fc2b159a0c944d5c9af39a80eb601c2 rather than the pinned 545a5d18ad3917d52192c41ce172ec4b41945751. Statements are checked by content, not revision.
✔ [3632/3636] Built NLA.IE19.Definitions (10s)
ℹ [3633/3636] Built NLA.IE19.Proof (11s)
info: NLA/IE19/Proof.lean:128:0: 'NLA.IE19.strict_scalar_gap' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/IE19/Proof.lean:130:0: 'NLA.IE19.counterexample_proved' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/IE19/Proof.lean:132:0: 'NLA.IE19.not_lowerBoundConjecture_proved' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/IE19/Proof.lean:134:0: 'NLA.IE19.not_sharpConjecture_proved' depends on axioms: [propext, Classical.choice, Quot.sound]
ℹ [3634/3636] Built Solution (7.0s)
info: Solution.lean:29:0: 'NLA.IE19.counterexample' depends on axioms: [propext, Classical.choice, Quot.sound]
info: Solution.lean:31:0: 'NLA.IE19.not_lowerBoundConjecture' depends on axioms: [propext, Classical.choice, Quot.sound]
info: Solution.lean:33:0: 'NLA.IE19.not_sharpConjecture' depends on axioms: [propext, Classical.choice, Quot.sound]
✔ [3635/3636] Built RegistryRecord (7.7s)
Build completed successfully (3636 jobs).