T-213: Mixed rectangle-measure lower bound reported, on the 201-direction net
V0 C0 Lower bound recorded
A rectangle measure of wand125/square-packing, published on 16 October 2026 and reported in jlevy/squares#446, is reported to prove = 9.86.
The certificate, mixed_n92_L986, is a density of 860 uniform rectangles in D4 orbits, and no point mass, of total mass 9199999/100000, on the net its candidate declares, the standard net of 201 half-angle tangents of step 83/40000 at core side 9977/10000. Since 9977/10000 (1 + 83/40000) = 399908091/400000000 < 1, and the last tangent 83/200 is past tan(pi/8), every unit square contains a concentric core at a net angle strictly in its interior. The search that found it started from a published certificate at a smaller count, mapped to this side and re-solved by linear programming (lifted, the source's provenance/search-notes.md); the certificate is the measure alone.
The source reports every such core capturing mass at least one at all 201 directions, by sqverify-proof-net, its copy of this repository's sqverify_fast changed to read the declared net, in two complete runs, and a control with every mass scaled by 197/200 refused at 32 sampled directions.
The value is above T-082's 977/100 = 9.77, the verified and reported lower bound at , by 9/100.
Here the maintained readers accepted its exact mass, declared-net and check2 premises from the retained release asset. No complete replay has run here, so the value stands as reported.
wand125 after Tokoharu and Levy, square-packing. The source says parts of the work were produced with AI assistance under human direction.
Significance, composition and next rung
- Significance
- Scored as a claim: if a complete replay passes, it is the strongest lower bound on record at , 9/100 above the reported lane, by the certificate kind and standard net of T-082, T-090 and T-091, with no new technique, at S3 as T-176 to T-178 are.
- Composition
- One reported certificate on its reported entry. The source's check is a copy of this repository's sqverify_fast crate with one change, so a sqverify-fast replay here would be re-implemented sharing the producer's components, as T-104's is, and no second implementation stands beside it.
- Next rung
- C3 needs a complete sqverify-fast census at all 201 directions of the retained candidate, with its whole-net control receipt (the 99/100 mutant at every direction, FC-1) and a review that reads this certificate, by the checklist of the 6 October declared-net soundness review. The census runs in think-f40c, priced at about 1.16 to 1.33 CPU-hours from the source's receipt.
- Unfinished confirmations
- C3 (think-f40c): a complete sqverify-fast census at all 201 directions of the retained candidate, with its whole-net control receipt (the 99/100 mutant at every direction, FC-1) and a review that reads this certificate, by the checklist of the 6 October declared-net soundness review. About 1.16 CPU-hours, up to about 1.33 (priced 2026-10-17).
- Novelty
- previously-published Present in an identified source
The case
Results on the case
11 results in the register on , oldest first, each with what it established and how it stands now.
2005 published T-007
for
V0 C1 Lower bound incomplete on this case, superseded by T-082
2026-09-04 published T-085
Nagamochi 2005, Lemma 1 is false for every container with and
V3 C3 Correction confirmed
Karakuş; Vlasenko · Karakuş 2026 · chelokot Nagamochi counterexample 2026 · packet · register
2026-09-29 published T-058
Rectangle-certificate ceiling
α·UB(n)proved for ..100;B·UB(n)on 64 grid rowsV3 C3 Method limit confirmed
Hosono after Tokoharu, Daniel · wand125 tools 2026 · packet · register
2026-09-29 published T-083
for every nonsquare
V3 C3 Lower bound confirmed on this case, superseded by T-082
Karakuş · Karakuş 2026 · source · register
2026-10-01 published T-069
Mixed rectangle-measure lower bounds replayed at
V3 C3 Lower bound confirmed on this case, superseded by T-082
Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 mixed bounds 2026-10-01 · packet · source · review · register
2026-10-02 published T-075
Mixed rectangle-measure lower bounds replayed at nine counts in
V3 C3 Lower bound confirmed on this case, superseded by T-082
Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 mixed bounds afternoon 2026-10-02 · packet · source 1 · source 2 · review · register
2026-10-03 published T-082
Mixed rectangle-measure lower bounds verified at 22 counts in
V3 C3 Lower bound confirmed
Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 mixed bounds 2026-10-03 · packet · packet · source · review · register
2026-10-04 published T-091
Mixed rectangle-measure lower bounds verified at 17 counts in
V3 C3 Lower bound confirmed on this case, superseded by T-082
Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 mixed bounds evening 2026-10-04 · packet · source · review · register
2026-10-07 published T-124
Reported non-strict local minima for 178 source configurations
V0 C0 Restricted optimality recorded
Daniel after Couzo · Daniel exact and local reports 2026 · packet · register
2026-10-13 published T-180
Closed-form lower bound for every non-square , reported
V0 C1 Lower bound reviewed on this case, superseded by T-082
Hosono · wand125 closed form 2026-10-14 · packet · packet · register
2026-10-16 published T-213 this result
Mixed rectangle-measure lower bound reported, on the 201-direction net
V0 C0 Lower bound recorded
Hosono after Tokoharu and Levy · wand125 fine-net lower bounds 2026-10-16 · packet · register
Links
- On this site
- Case record, · Frontier row, · T-213 in the results table
On GitHub, at main
- Register
- T-213 in
results.yaml, line 29363 - Evidence
E-wand125-fine-net-n92-986-report- Proofs and certificates
- certificate
candidate.json.gz - Sources
- wand125 fine-net lower bounds 2026-10-16
- Source packet
resources/web/wand125-fine-net-lower-bounds-2026-10-16/README.md- Artifacts
7 artifacts and controls
resources/web/wand125-fine-net-lower-bounds-2026-10-16/README.mdresources/web/wand125-fine-net-lower-bounds-2026-10-16/acquisition/sources.jsonresources/web/wand125-fine-net-lower-bounds-2026-10-16/acquisition/release-assets.jsonresources/web/wand125-fine-net-lower-bounds-2026-10-16/release/certificates/mixed_n92_L986/candidate.json.gzresources/web/wand125-fine-net-lower-bounds-2026-10-16/release/certificates/mixed_n92_L986/check2/receipt.jsonresources/web/wand125-fine-net-lower-bounds-2026-10-16/receipts/premises-n92.jsondevtools/fine_net_followup.py- Case file
frontier/n-092.md(verified lower, verified upper, reported lower, reported upper)