T-227: Couzo's refinements of de Winter's 227 and 229, below T-196 at both
V0 C0 Upper bound recorded superseded by T-225
Two complete rational source certificates report finite upper-bound improvements at the exact sides they state: and . Complete native feasibility outcomes are retained separately; the entry awaits independent review. At 227 it is below de Winter's T-196, the house best packing when it was reported; Daniel's solved view of this packing (T-225), smaller still, has been the house since 22 October 2026. At 229 Daniel's #674 opening and update (T-198, T-199), reported after it, are smaller.
The issue states that each bound is strictly smaller than the source's previous published index and a reviewed comparison envelope including deletion and repeated L borders, and the manifest records the author's checker receipts with the source's exact checker verify_bound_certificate.py (Daniel's MIT verifier, modified by Couzo with Codex), pinned here by digest and not run. Those statements are the author's; no source program ran here.
Credit Couzo (https://github.com/franciscouzo/square-packing) with refinements of de Winter's #668 packings (T-196), as the author's comment of 17 October says: at 227 a CT105 web submission (method fq) seeded from de Winter's #668 certificate by way of Daniel's exact form of it, which the source does not say who made, and at 229 an slp refinement (search job 106640) of de Winter's #668 certificate.
Significance, composition and next rung
- Significance
- Refinements of de Winter's 227 and 229 packings (T-196), the same arrangement solved lower by 1.71e-4 at 227 and 1.67e-8 at 229: a citable step that moves no theorem, S2 as T-199 (a same-arrangement step of 1.32e-5) and T-225, whose rationale already gives the 1.71e-4 at 227 to this report. No lower bound or optimum.
- Next rung
- Independently review the retained replay (think-0nse). At 227 the entry is 1.71e-4 below T-196, the house when it was reported, and Daniel's solved view of this packing (T-225), 1.76e-11 below it, has been the house since 22 October 2026; at 229 it is superseded on entry by #674's opening and update (T-198, T-199), reported after it, T-199 1.32e-5 below it. The 44 rows beyond the corpus are the source's dated beyond-horizon rows since 22 October 2026, recorded in report order by the backlog ledger (upper-bounds-backlog-20261022).
- Unfinished confirmations
- C3 (think-0nse): Review the retained two-route replay of #672's 227 and 229 certificates and enter it as confirming evidence, with sharp controls at 1e-30. Not priced.
- Regularizations
- n = 227: a regularization of T-196’s packing by Couzo (fq refinement, a CT105 web submission (f0ca7a65) seeded from de Winter's #668 certificate by way of Daniel's exact form; solved to its side; identity: the source’s claim; nearest centres one to one; 59 squares moved, at most 0.0796; turns up to 5.842°).
n = 229: a regularization of T-196’s packing by Couzo (slp refinement (search job 106640) of de Winter's #668 certificate; solved to its side; identity: the source’s claim; nearest centres one to one; 57 squares moved, at most 0.00941; turns up to 0.0308°). - Novelty
- previously-published Present in an identified source
The cases
As published
Proven
- exact
Citation record n-227
lowerKarakuş 2026, arXiv corrects Nagamochi 2005 (confirmed T-083)
upperde Winter et al., GitHub (confirmed T-225)
Open
- optimality
The case record
As published
Proven
- exact
Citation record n-229
lowerKarakuş 2026, arXiv corrects Nagamochi 2005 (confirmed T-083)
upperDaniel 2026, GitHub (confirmed T-225)
Open
- optimality
The case record
Results on these cases
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 these cases, superseded by T-083
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-083 ·
for every nonsquare
V3 C3 Lower bound confirmed
Karakuş · Karakuş 2026 · source · register
2026-10-05 published T-101 ·
Exact certificates of 77 catalogue packings:
s(n) ≤ S',1.2e-16to9.8e-15above each sideV3 C3 Upper bound confirmed on these cases, superseded by T-225
Daniel after Couzo, de Winter, Ellsworth, Levy · evand exact optima 2026-10-05 · packet · register
2026-10-12 established T-155 ·
Exact regularized sides at 59 counts,
5.4e-20to9.9e-15below the ceilings they replaceV3 C3 Upper bound confirmed on these cases, superseded by T-225
2026-10-13 published T-180 ·
Closed-form lower bound for every non-square , reported
V0 C1 Lower bound reviewed on these cases, superseded by T-083
Hosono · wand125 closed form 2026-10-14 · packet · packet · register
2026-10-17 published T-196 ·
de Winter reports three smaller rational upper bounds at 227, 229 and 260
V3 C3 Upper bound confirmed superseded by T-225
de Winter after Levy · de Winter upper bounds 2026-10-17 · packet · register
2026-10-17 published T-198 ·
Daniel's opening n229 dilation certificate, after Couzo and de Winter
V3 C3 Upper bound confirmed superseded by T-225
Daniel after Couzo, de Winter, Levy · Daniel n229 dilation 2026-10-17 · packet · register
2026-10-17 published T-227 this result ·
Couzo's refinements of de Winter's 227 and 229, below T-196 at both
V0 C0 Upper bound recorded superseded by T-225
Couzo after de Winter, Daniel, Levy · Couzo issue 672 2026-10-17 · packet · packet · register
2026-10-18 published T-199 ·
Daniel's smaller n229 update, replacing the opening certificate
V3 C3 Upper bound confirmed superseded by T-225
Daniel after Couzo, de Winter, Levy · Daniel n229 dilation update 2026-10-18 · packet · register
2026-10-20 published T-225 ·
Daniel's solved, regularized views at 204, 227, 229 and 260, each the smallest side reported there
V3 C3 Upper bound confirmed
Daniel after Couzo, de Winter, Polkovskyi, Levy · Daniel regularized lists 2026-10-20 · packet · register
Links
- On this site
- Case record, · Frontier row, · Case record, · Frontier row, · T-227 in the results table
On GitHub, at main
- Register
- T-227 in
results.yaml, line 31149 - Evidence
E-couzo-672-certificate-report- Proofs and certificates
- certificate
certificates - Sources
- Couzo issue 672 2026-10-17
- Source packet
resources/web/couzo-issue672-2026-10-17/README.md·resources/web/evand-regularized-2026-10-20/README.md- Artifacts
11 artifacts and controls
resources/web/couzo-issue672-2026-10-17/README.mdresources/web/couzo-issue672-2026-10-17/acquisition/claims.jsonresources/web/couzo-issue672-2026-10-17/source/certificates/n227.certresources/web/couzo-issue672-2026-10-17/source/certificates/n229.certresources/web/couzo-issue672-2026-10-17/receipts/exact-certification.json.xzresources/web/couzo-issue672-2026-10-17/measure/identity.jsonresources/web/evand-regularized-2026-10-20/measure/identity.jsoncampaign/issue-intake/upper-bounds-20261018/README.mddevtools/upper_bound_reports.pytests/test_upper_bound_reports.pytests/test_upper_bound_reports_couzo_670_672_675.py- Case file
frontier/n-227.md(verified lower, verified upper, reported lower, reported upper) ·frontier/n-229.md(verified lower, verified upper, reported lower, reported upper)