Case record
The best packing known for 46 squares, side 7, Bentz 2009

n=46

O=proved

s(46)=7

7
678
6.7827.782
nn+1

Proven

s(46)=7

  • optimal
  • exact

Citation record n-046

lowerBentz 2010 (confirmed T-004, T-008, T-064)

Bounds

Best known packing

7

Found by
Bentz 2009
Construction
hand
Source
[Kingbird]
Evidence
E-kingbird-upper-register
Verified upper bound

7

The reported value, verified here.

Evidence
E-basic-grid-upper
Reported lower bound

7

Proved by
Bentz 2010
Kind
unavoidable points
Source
[Bentz 2010]
Evidence
E-bentz-2010-proof
Verified lower bound

7

The reported value, verified here.

Evidence
E-bentz-2010-proof, E-bentz46-theorem8-audit, E-k2m3-evand-valid7-qx2-replay, E-k2m3-evand-bentz-lean-build
Gap

0

Solved: the verified bounds meet.

Results in the register

  • T-004 V3 C3 Bentz · 2026-08-31 · n = 46

    Bentz 2010, Theorem 8 (s(46)≥7) is correct as printed, machine-audited in full

    Claim and records
    Claim
    Bentz 2010, Theorem 8: the printed 45-point unavoidable-set argument for s(46)≥7 is correct as printed, machine-audited in full.
    Significance
    As far as the archived corpus shows, the first machine verification of a published unavoidable-set proof in this literature; the theorem is Bentz's, the audit is the contribution.
    Novelty
    previously-published Present in an identified source
    Records

    n = 46registerevidence 1evidence 2source

  • T-007 V0 C1 Nagamochi · 2026-08-31 · 321 cases

    s(n)≥min(⌈n⌉,n−2⌊n⌋+1+1) for 4≤n≤324

  • T-008 V3 C3 Bentz · 2026-08-31 · n = 46

    s(46)=7

    Claim and records
    Claim
    s(46)=7: the lower half by T-004's audited unavoidable set, the upper half by the exact 7×7 grid packing of 46 squares.
    Significance
    The first equality from the literature whose both halves are machine-confirmed here end-to-end.
    Novelty
    previously-published Present in an identified source
    Records

    n = 46registerevidence 1evidence 2evidence 3source

  • T-058 V3 C3 Hosono after Tokoharu, Daniel · 2026-09-29 · 100 cases

    Rectangle-certificate ceiling α·UB(n) proved for n=1..100; B·UB(n) on 64 grid rows

  • T-064 V3 C3 Daniel after Burns, Massaccesi · 2026-10-01 · 13 cases

    s(k2−3)=k for every integer k from 6 up; k=6…18 are the cases held here

  • T-083 V3 C3 Karakuş · 2026-10-02 · 301 cases

    s(n)≥1/2+n−⌊n⌋+1/4 for every nonsquare 8≤n≤324

  • T-085 V3 C3 Karakuş; Vlasenko · 2026-10-02 · 315 cases

    Nagamochi 2005, Lemma 1 is false for every container with a>3 and b>2

  • T-124 V0 C0 Daniel after Couzo · 2026-10-07 · 178 cases

    Reported non-strict local minima for 178 source configurations

Verification

upper: replayed here; lower: external proof (read here, defect recorded), audited here, replayed here

—

Rigidity

not rigid, numerically checked, numerical multiprecision

Evidence: E-translation-escape-not-rigid

Scope

Square 39 of the retained witness (witness id 40) translates 1 along (0, 1) with the packing still valid, so the configuration admits a non-trivial feasible motion; 4 of its 46 squares do. Every constraint is exactly affine in the slide parameter, so the arithmetic carries no linearization error, but the coordinates are the witness's own finite-precision transcription: this settles the retained configuration, not the true optimum. Rigidity and optimality are independent, and this bears only on the former.

s(46) — solved

s(46)=7, proved by Bentz (2010) in the same paper as s(13)=4.

The m2−3 family

46=72−3. Until September 2026 the family s(m2−3)=m was known exactly only at m=3,4,5,6,7: s(6)=3, s(13)=4, s(22)=5, s(33)=6, and this case, which was then the largest n known exactly other than through the two general families (perfect squares, and Nagamochi’s m2−1, m2−2). Corrected 2 October 2026: Nagamochi’s proof of both families is incomplete, his Lemma 1 being false; m2−1 is proved again by Karakuş (T-084) and m2−2 by chelokot’s Lean proof, replayed here (T-086; review). This register had recorded that proof as verified, its own error, logged as defect D-516.

The family is no longer a conjecture. Daniel proved s(k2−3)=k for every integer k≥6 (T-064), which with the five cases above gives s(m2−3)=m for every m≥3.

A second proof, replayed here

s(46)=7 is the case k=7 of Daniel’s theorem, and its finite statement, Valid7, is a statement about this case’s own container: every closed unit square in [0,7]2 has mass at least one under a measure of total mass below 46. Daniel’s exact checker of Valid7 was replayed here in full on the retained cover on 2 and 3 October 2026, every root’s leaves equal to the published run’s (E-k2m3-evand-valid7-qx2-replay), and his Lean reduction from it to every k≥6 was built here with the pinned toolchain and depends only on the standard axioms (E-k2m3-evand-bentz-lean-build). The verified lower bound cites both beside Bentz’s proof since 11 October 2026; until then it cited the proof and this repository’s audit of its Theorem 8 alone. The source’s CREDITS.md says the work was produced by Claude (Anthropic) in a single session under human direction.

Verification Code

The programs behind this case’s verified bounds, by their evidence. The code column says how the code that ran stands to the code its producer used. VERIFIERS.md says what each program is and whose it is.

bound evidence run code programs
verified lower E-bentz-2010-proof a published proof no code no verification code
verified lower E-bentz46-theorem8-audit audited here independent V-sqpack-cover (first-party)
verified lower E-k2m3-evand-valid7-qx2-replay replayed here producer’s code V-evand-qx2-zm-py (external)
verified lower E-k2m3-evand-bentz-lean-build replayed here producer’s code V-evand-lean (external)
verified upper E-basic-grid-upper replayed here independent V-check-basic-bounds (first-party)