T-235: Hosono reports a Lean kernel proof that , on Daniel's mixed-measure checker
V0 C0 Formalization recorded
Hosono (wand125) reports a Lean 4 kernel proof that , a formalization of T-066, whose lower half this record holds on a replay of Daniel's zmx2 over the same cover. Its theorem, SquarePacking.s59_eq_8 : minSide 59 = 8, says that the least side of a square holding 59 closed unit squares, each translated and rotated, with pairwise disjoint interiors, is 8; the grid attains it.
The lower half, s59_ge_8, applies Daniel's le_minSide_mixed to T-066's mixed cover, 26,308 points and 5,240 segments of [0,8]^2 with masses w/10^8 and total below 59, whose D4 invariance and total are checked by decide +kernel, through a box tree over 80 x 80 root cells of the D4 region: 43,154 generated Part files and 290 Roots files in 290 batches, every chunk one decide +kernel of ZMTreeM.checkM, proved sound once, on Daniel's library used unchanged from evand/square-packing. The source reports the axioms propext, Classical.choice and Quot.sound, no sorry and no native_decide, and a run of about 862 CPU-hours, of which it publishes a per-task receipt; the generated files and the axiom output are not published. Nothing here has built it.
Hosono after Daniel, square-packing, 11 October 2026. The commit names Claude as co-author.
Significance, composition and next rung
- Significance
- A proof-assistant route to a value T-066 holds on a complete replay, by the same cover and the same author's checker family checked in Lean's kernel instead: a citable detail that changes no theorem.
- Composition
- One cited entry, the source's report (E-n059-wand125-lean-kernel-report), which claims the exact value in Lean, the grid inside the proof. T-066's zmx2 replay is not cited: it is T-066's evidence, and a kernel check of the same cover is what this entry adds. No build is retained here, so V0; no review has read it, so C0.
- Next rung
- C1 needs the stage 4 mathematical review of the proof, which starts from the packet. V3 and C3 need a complete build here or by a third party retained here, from the retained scripts and Daniel's library staged from the 7 October evand packet, with its axiom receipt (think-cs9x): about 862 CPU-hours by the source's receipt, with 9.8 GB per Part process and 35 GB for the last two modules, so it is held above the owner's 40 CPU-hour item cap and this host. A build of Pts.lean alone decides the cover's data facts in Lean and moves no rung.
- Unfinished confirmations
- C1 (think-xk3f): the stage 4 mathematical review of s59_eq_8, its statement, the batch structure and the generator, read from the retained packet. Not priced.
C3 (think-cs9x): a complete build of the 43,444 generated modules, Cov.lean and S59Lower.lean from the retained scripts on the library at 1718a580, compared with SOURCES.sha256, with its axiom receipt, here or by a third party whose build is retained here. About 862 CPU-hours (priced 2026-10-23). - 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-066
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
2026-09-27 published T-046
Rectangle-density lower bounds verified at 48 counts in
V3 C3 Lower bound confirmed superseded by T-066
Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 rectangle bounds 2026 · wand125 rectangle bounds 2026-09-28 · packet · packet · source · review · register
2026-09-28 published T-070
Rectangle-density lower bounds replayed at 25 counts in
V3 C3 Lower bound confirmed superseded by T-066
Hosono after Tokoharu, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 rectangle bounds 2026-09-28 · packet · packet · source · review · 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-066
Karakuş · Karakuş 2026 · source · register
2026-10-01 published T-066
, by a mixed cover of points and grid-line segments
V3 C3 Optimality confirmed
Hosono after Daniel, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 exact covers 2026-10-01 · 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
2026-10-11 published T-235 this result
Hosono reports a Lean kernel proof that , on Daniel's mixed-measure checker
V0 C0 Formalization recorded
Hosono after Daniel, Levy, Stromquist, Nagamochi, Burns, Massaccesi · wand125 n59 Lean kernel 2026-10-11 · packet · source · register
2026-10-12 published T-261
Reported grade-C local minima for 233 source configurations of field degree at most 4
V3 C1 Restricted optimality incomplete
Daniel after Schadt, Ellsworth, Levy · Daniel exact and local reports 2026-10-12 · packet · 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-066
Hosono · wand125 closed form 2026-10-14 · packet · packet · register
Links
- On this site
- Case record, · Frontier row, · T-235 in the results table
- Issues
- Issue #783
On GitHub, at main
- Register
- T-235 in
results.yaml, line 33434 - Evidence
E-n059-wand125-lean-kernel-report- Proofs and certificates
- certificate
S59Lower.lean· proofS59Lower.lean - Sources
- wand125 n59 Lean kernel 2026-10-11
- Source packet
resources/web/wand125-n59-lean-kernel-2026-10-11/README.md- Artifacts
7 artifacts and controls
resources/web/wand125-n59-lean-kernel-2026-10-11/README.mdresources/web/wand125-n59-lean-kernel-2026-10-11/square-packing/problems/square-lower-bounds/certificates/k2m5_n59_L8/lean/Sqpack/S59Lower.leanresources/web/wand125-n59-lean-kernel-2026-10-11/square-packing/problems/square-lower-bounds/certificates/k2m5_n59_L8/lean/Sqpack/S59T/Pts.leanresources/web/wand125-n59-lean-kernel-2026-10-11/square-packing/problems/square-lower-bounds/certificates/k2m5_n59_L8/lean/README.mdresources/web/wand125-n59-lean-kernel-2026-10-11/square-packing/problems/square-lower-bounds/certificates/k2m5_n59_L8/lean/receipts/kernel_tasks.jsonl.gzresources/web/wand125-n59-lean-kernel-2026-10-11/receipts/evand-library-closure-1718a580.jsondevtools/lean_closure.py- Case file
frontier/n-059.md(verified lower, verified upper, reported lower, reported upper)