T-090: Mixed rectangle-measure lower bounds verified at 17 counts in
V3 C3 lower bound confirmed
Sixteen rectangle densities of wand125/square-packing-bounds, checked at coverage one and published on 3 and 4 October 2026, prove = 6.8475, = 6.9075, = 6.9725, = 7.47, = 7.8025, = 7.8725, = 8.475, = 8.62, = 8.76, = 8.94, = 9.4075, = 9.503, = 9.6125, = 9.88, = 9.94 and = 9.965. A packing of n + 1 squares contains one of n, so the value also bounds , where it is above the verified bound the record held: 17 counts in all.
Each is a density of 358 to 630 uniform rectangles in D4 orbits and no point mass, of total mass n - 1/100000, at core side 9977/10000 on 201 net half-angles of step 83/40000, of the kind and checker of T-082. The source reports each accepted at all 200 oblique net angles by code/mixed_rotated_verify.cpp, its research copy of Tokoharu's verify.cpp at coverage threshold one, and at the axis by exact integer tables. Nine supersede the source's certificates at the same count: eight of T-082's, and at T-071's. At the other seven they are the source's first mixed certificates.
All 16 values were above what the record reported at their counts, by 0.003 to 0.0375: over T-082 at eight counts, T-071 at , and the source's rectangle certificates (T-046, T-068, T-077) at seven. At and 94 the source's certificates of later that day (T-091) are higher, and at and 84 those of 5 October (T-094), each verified here, so the verified lower bound there is theirs. Over the verified lower bounds they replace, at the other twelve counts and at , the rise is 0.005 to 0.1175.
Each certificate was decided here on 6 October 2026 by sqverify-fast, this repository's clean-room measure verifier, at all 201 net directions of the retained candidate, and two mutants of each scaled below coverage one were refused: confirmed, independently re-implemented. The verifier shares no code with the source's checker and runs the same net-and-shrink method, so it is a second implementation and not a second method. The source's own checker was not run here.
wand125 after Tokoharu and Levy, square-packing-bounds. Registration was requested in 16 comments of 3 and 4 October 2026 on jlevy/squares#282. The source says parts of the work were produced with AI assistance under human direction.
Significance, composition and next rung
- Significance
- The strongest verified lower bounds on record at 13 counts from to 96, and the strongest reported at 12 of its own. Further sizes from the generator and checker of T-069, T-071, T-072, T-075 and T-082, with no new technique, at S3 as those are; the 5 October review of these certificates confirmed S3.
- Composition
- 16 primary certificates, each on its own reported entry and its own replay entry. takes the certificate directly, its mass being below that count, so no step is added. Each replay is sqverify-fast at all 201 net directions of the retained candidate: one interval-certified method, replayed here by an independent implementation, C3. The source's checker and axis tables were not run here, so no second method and no reproduction with the producer's code stands beside it.
- Next rung
- V4 and C4 need a human oversight record and two adversarial AI reviews of the claim by distinct reviewers: the 5 October review of these certificates is one, and the review of the census route of the same day decided the route, not these certificates' mathematics. Replays of the source's own checker (about 146 CPU-hours planned, devtools.audit_wand125_point_and_mixed mixed-shard wand125-mixed-bounds-2026-10-04 --runners 8) would add a reproduction with the producer's code beside the rung; a second machine method would be a method-distinct decision of rotated coverage.
- Novelty
- previously-published Present in an identified source
The cases
This result concerns 17 cases, too many to draw one by one. Each is listed with the film’s bounds, the proved lower bound and the best known side, and links to its case record, where its packing and number line are drawn.
| n | Proved lower | Best known | Gap | Status | Records |
|---|---|---|---|---|---|
| 42 | 6.847500 | 7 | 0.1525 | open= | frontier n-042.md |
| 43 | 6.907500 | 0.0925 | frontier n-043.md | ||
| 44 | 6.972500 | 0.0275 | frontier n-044.md | ||
| 51 | 7.470000 | 7.690356 | 0.22035593… | frontier n-051.md | |
| 56 | 7.802500 | 8 | 0.1975 | frontier n-056.md | |
| 57 | 7.872500 | 0.1275 | frontier n-057.md | ||
| 67 | 8.480000 | 8.707107 | 0.22710678… | frontier n-067.md | |
| 69 | 8.620000 | 8.827195 | 0.20719465… | frontier n-069.md | |
| 72 | 8.760000 | 9 | 0.24 | frontier n-072.md | |
| 75 | 8.940000 | 0.06 | frontier n-075.md | ||
| 84 | 9.411000 | 9.698053 | 0.28705206… | frontier n-084.md | |
| 86 | 9.503000 | 9.820566 | 0.31756573… | frontier n-086.md | |
| 88 | 9.620000 | 9.882452 | 0.26245103… | frontier n-088.md | |
| 93 | 9.880000 | 10 | 0.12 | frontier n-093.md | |
| 94 | 9.950000 | 0.05 | frontier n-094.md | ||
| 95 | 9.965000 | 0.035 | frontier n-095.md | ||
| 96 | 9.970000 | 0.03 | frontier n-096.md |
Results on these cases
28 results in the register on these cases, oldest first
2005 published T-007 · 17 of these cases
for
lower bound incomplete on these cases, superseded by T-081 (reported), T-082, T-090, T-091 and T-094
Nagamochi · Nagamochi 2005 · source · register
2026-09-04 published T-085 · 17 of these cases
Nagamochi 2005, Lemma 1 is false for every container with and
correction confirmed
Karakuş; chelokot · Karakuş 2026 · chelokot Nagamochi counterexample 2026 · packet · register
2026-09-22 published T-044 · cases 56, 57, 69, 72
Weighted point lower bounds for ten counts in , plus seven from the same files
lower bound confirmed superseded by T-090
wand125 after Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 point bounds 2026 · packet · source · review · register
2026-09-24 published T-088 · case 69
, Ellsworth's degree-38 packing, certified exactly from its picture
upper bound confirmed superseded by T-101
Ellsworth after hmbelvedere, Cantrell, Schadt, Morandi · Ellsworth n69 2026-09-24 · packet · packet · register
2026-09-27 published T-045 · case 75
Rectangle-density lower bounds replayed at 15 counts in
lower bound confirmed superseded by T-090
wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 rectangle bounds 2026 · packet · packet · source · review · register
2026-09-27 published T-046 · 14 of these cases
Rectangle-density lower bounds reported for 48 counts in
lower bound recorded superseded by T-090, T-091 and T-094
wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 rectangle bounds 2026 · wand125 rectangle bounds 2026-09-28 · packet · packet · register
2026-09-28 published T-048 · case 51
lower bound confirmed on these cases, superseded by T-090
wand125 after Daniel, Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 point and mixed bounds 2026-09-28 · packet · source · review · register
2026-09-28 published T-070 · 10 of these cases
Rectangle-density lower bounds replayed at 25 counts in
lower bound confirmed superseded by T-090 and T-094
wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 rectangle bounds 2026-09-28 · packet · packet · source · review · register
2026-09-29 published T-058 · 17 of these cases
Rectangle-certificate ceiling
α·UB(n)proved for ..100;B·UB(n)on 64 grid rowsmethod limit confirmed
wand125 after Tokoharu, Daniel · wand125 tools 2026 · packet · register
2026-09-29 published T-083 · 17 of these cases
for every nonsquare
lower bound confirmed on these cases, superseded by T-081 (reported), T-082, T-090, T-091 and T-094
Karakuş · Karakuş 2026 · source · register
2026-10-01 published T-068 · 11 of these cases
Rectangle-density lower bounds verified at 34 counts in
lower bound confirmed on these cases, superseded by T-090 and T-091
wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 rectangle bounds 2026-10-01 · packet · source · review · register
2026-10-01 published T-074 · 11 of these cases
Rectangle-density lower bounds replayed at 31 counts in
lower bound confirmed on these cases, superseded by T-090 and T-091
wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 rectangle bounds 2026-10-01 · packet · packet · source · review · register
2026-10-02 published T-071 · cases 84, 86
Mixed rectangle-measure lower bounds replayed at
lower bound confirmed superseded by T-090 and T-094
wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 mixed bounds 2026-10-02 · packet · source · review · register
2026-10-02 published T-075 · cases 86, 88, 93, 96
Mixed rectangle-measure lower bounds replayed at nine counts in
lower bound confirmed on these cases, superseded by T-081 (reported), T-082, T-090 and T-091
wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 mixed bounds afternoon 2026-10-02 · packet · source 1 · source 2 · review · register
2026-10-02 published T-077 · case 42
Rectangle-density lower bounds replayed at , 42 and 70
lower bound confirmed superseded by T-090
wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 rectangle bounds 2026-10-02 · packet · packet · source 1 · source 2 · review 1 · review 2 · register
2026-10-03 published T-081 · case 96
for every integer from 5 up; are the cases held here
optimality reviewed
Daniel after Burns, Massaccesi · evand square-packing 2026-10-03 · packet · packet · source · review · register
2026-10-03 published T-082 · 9 of these cases
Mixed rectangle-measure lower bounds verified at 22 counts in
lower bound confirmed
wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 mixed bounds 2026-10-03 · packet · packet · source · review · register
2026-10-04 published T-090 this result · 17 of these cases
Mixed rectangle-measure lower bounds verified at 17 counts in
lower bound confirmed
wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 mixed bounds 2026-10-04 · packet · source · review · register
2026-10-04 published T-091 · 5 of these cases
Mixed rectangle-measure lower bounds verified at 17 counts in
lower bound confirmed
wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 mixed bounds evening 2026-10-04 · packet · source · review · register
2026-10-05 published T-094 · cases 67, 84
Mixed rectangle-measure lower bounds verified at and
lower bound confirmed
wand125 after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 mixed bounds 2026-10-05 · packet · source · review · register
2026-10-05 published T-101 · cases 51, 69, 88
Exact certificates of 77 catalogue packings:
s(n) ≤ S',1.2e-16to9.8e-15above each sideupper bound confirmed
Daniel after Couzo, de Winter, Ellsworth, Levy · evand exact optima 2026-10-05 · packet · register
2026-10-07 published T-116 · case 88
at nine counts, from the second SQUISH update’s new rational packings
upper bound confirmed on these cases, superseded by T-127
Chaoweeraprasit after Ellsworth, Couzo and SQUISH · SQUISH second update 2026-10-07 · packet · register
2026-10-07 published T-124 · 11 of these cases
Reported non-strict local minima for 178 source configurations
restricted optimality recorded
Daniel after Couzo · Daniel exact and local reports 2026 · packet · register
2026-10-08 published T-125 · cases 51, 84, 86, 88
Complete rational construction reports at 25 counts
upper bound confirmed
ry-xu · ry-xu square packing 2026 · packet · register
2026-10-08 published T-126 · case 51
Undilated n51 construction over Q(sqrt2)
upper bound confirmed
ry-xu · ry-xu square packing 2026 · packet · register
2026-10-08 published T-127 · case 88
Fourteen rational refinements, seventeen complete source cases
upper bound confirmed
Gupta after Chaoweeraprasit, Daniel · Gupta rational refinements 2026-10-08 · packet · register
2026-10-08 published T-130 · cases 84, 86
Five follow-up rational refinements from Francisco Couzo
upper bound confirmed
Couzo after Xu, Daniel, Ellsworth, Levy · Couzo follow-up refinements 2026-10-08 · packet · register
2026-10-09 published T-138 · cases 84, 86
Exact witnesses at Mishapolk's printed ceilings, the smallest known at 103 and 258 when registered
upper bound confirmed
Mishapolk after Stenlund, Friedman, Ellsworth, Chaoweeraprasit, Couzo, Xu, Levy · Mishapolk decimal poses 2026-10-09 · packet · register
Links
- On this site
- The frontier survey · T-090 in the results table
On GitHub, at main
- Register
- T-090 in
results.yaml, line 8733 - Evidence
E-n042-wand125-mixed-68475-report·E-n042-wand125-mixed-68475-sqverify-fast-replay·E-n043-wand125-mixed-69075-report·E-n043-wand125-mixed-69075-sqverify-fast-replay·E-n044-wand125-mixed-69725-report·E-n044-wand125-mixed-69725-sqverify-fast-replay·E-n051-wand125-mixed-747-report·E-n051-wand125-mixed-747-sqverify-fast-replay·E-n056-wand125-mixed-78025-report·E-n056-wand125-mixed-78025-sqverify-fast-replay·E-n057-wand125-mixed-78725-report·E-n057-wand125-mixed-78725-sqverify-fast-replay·E-n067-wand125-mixed-8475-report·E-n067-wand125-mixed-8475-sqverify-fast-replay·E-n069-wand125-mixed-862-report·E-n069-wand125-mixed-862-sqverify-fast-replay·E-n072-wand125-mixed-876-report·E-n072-wand125-mixed-876-sqverify-fast-replay·E-n075-wand125-mixed-894-report·E-n075-wand125-mixed-894-sqverify-fast-replay·E-n084-wand125-mixed-94075-report·E-n084-wand125-mixed-94075-sqverify-fast-replay·E-n086-wand125-mixed-9503-report·E-n086-wand125-mixed-9503-sqverify-fast-replay·E-n088-wand125-mixed-96125-report·E-n088-wand125-mixed-96125-sqverify-fast-replay·E-n093-wand125-mixed-988-report·E-n093-wand125-mixed-988-sqverify-fast-replay·E-n094-wand125-mixed-994-report·E-n094-wand125-mixed-994-sqverify-fast-replay·E-n095-wand125-mixed-9965-report·E-n095-wand125-mixed-9965-sqverify-fast-replay- Proofs and certificates
- certificate
candidate.json.gz· proofSOUNDNESS.md· auditreview-2026-10-05-wand125-october-4-certificates.md· certificatecandidate.json.gz· certificatecandidate.json.gz· certificatecandidate.json.gz· certificatecandidate.json.gz· certificatecandidate.json.gz· certificatecandidate.json.gz· certificatecandidate.json.gz· certificatecandidate.json.gz· certificatecandidate.json.gz· certificatecandidate.json.gz· certificatecandidate.json.gz· certificatecandidate.json.gz· certificatecandidate.json.gz· certificatecandidate.json.gz· certificatecandidate.json.gz - Sources
- wand125 mixed bounds 2026-10-04 (its own site, retained copy)
- Source packet
resources/web/wand125-mixed-bounds-2026-10-04/README.md- Artifacts
41 artifacts and controls in 7 directories. Complete artifact list in the result entry. docs/project/reviews packing/benchmarks/measure-verifier/census-mixed packing/benchmarks/measure-verifier/census-mixed/wand125-mixed-bounds-2026-10-04 packing/devtools packing/resources/web/wand125-mixed-bounds-2026-10-04 packing/resources/web/wand125-mixed-bounds-2026-10-04/receipts packing/tests
- Case file
- each case’s file is linked from its row above