clopen.solutions

MI-26: a counterexample to concave unitary-orbit subadditivity

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

George Stepaniants

Proves the original function-class equivalence, genuine finite-spectrum CFC and half-line extension bridges, exact polynomial identities for two rational projections, their positive quadratic-form obstruction, and the full negation of the universal complex PSD unitary-orbit assertion.

Claims

LEAN VERIFIED OP-00107 — Concave unitary-orbit subadditivity without monotonicity
Disproof · statement matched the canonical formalisation

Files and sources

Paper
OpenProblemsInNLA @ e375a6f, MI-26/lean/ ↗
Lean bundle
submissions/bundles/openproblemsinnla-mi-26-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
0:01:29.463687

Declarations audited

DeclarationKindAxiomsUnused hypothesesCanonical
NLA.MI26.not_subadditivityConjecture theorem · Prop propext, Classical.choice, Quot.sound none matched
RegistryProblems.Problem_OP_00107 definition propext, Classical.choice, Quot.sound none no canonical statement

NLA.MI26.not_subadditivityConjecture

Not NLA.MI26.SubadditivityConjecture

RegistryProblems.Problem_OP_00107

Prop

Build log

RegistryProblems: built against the registry's copy at 38ca23a44fc2b159a0c944d5c9af39a80eb601c2 rather than the pinned 545a5d18ad3917d52192c41ce172ec4b41945751. Statements are checked by content, not revision.
✔ [3147/3151] Built NLA.MI26.Definitions (6.2s)
ℹ [3148/3151] Built NLA.MI26.Proof (6.4s)
info: NLA/MI26/Proof.lean:187:0: 'NLA.MI26.admissibleFunction_iff_proved' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/MI26/Proof.lean:188:0: 'NLA.MI26.functionalCalculus_eq_spectral_proved' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/MI26/Proof.lean:189:0: 'NLA.MI26.functionalCalculus_congr_nonneg_proved' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/MI26/Proof.lean:190:0: 'NLA.MI26.quadratic_cfc_proved' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/MI26/Proof.lean:191:0: 'NLA.MI26.witness_positive' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/MI26/Proof.lean:192:0: 'NLA.MI26.witness_data_proved' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/MI26/Proof.lean:193:0: 'NLA.MI26.counterexample_proved' depends on axioms: [propext, Classical.choice, Quot.sound]
info: NLA/MI26/Proof.lean:194:0: 'NLA.MI26.not_subadditivityConjecture_proved' depends on axioms: [propext, Classical.choice, Quot.sound]
ℹ [3149/3151] Built Solution (3.0s)
info: Solution.lean:86:0: 'NLA.MI26.admissibleFunction_iff' depends on axioms: [propext, Classical.choice, Quot.sound]
info: Solution.lean:87:0: 'NLA.MI26.functionalCalculus_eq_spectral' depends on axioms: [propext, Classical.choice, Quot.sound]
info: Solution.lean:88:0: 'NLA.MI26.functionalCalculus_congr_nonneg' depends on axioms: [propext, Classical.choice, Quot.sound]
info: Solution.lean:89:0: 'NLA.MI26.quadratic_cfc' depends on axioms: [propext, Classical.choice, Quot.sound]
info: Solution.lean:90:0: 'NLA.MI26.witness_data' depends on axioms: [propext, Classical.choice, Quot.sound]
info: Solution.lean:91:0: 'NLA.MI26.counterexample' depends on axioms: [propext, Classical.choice, Quot.sound]
info: Solution.lean:92:0: 'NLA.MI26.not_subadditivityConjecture' depends on axioms: [propext, Classical.choice, Quot.sound]
✔ [3150/3151] Built RegistryRecord (3.9s)
Build completed successfully (3151 jobs).