On hold: outside the current catalog. Coding assistants implemented searches and drafted proofs, but no retained selection-program discovery or essential mathematical idea is individually assigned to them. Reviewed 2026-10-21. This page preserves the publication history.

Cremer reports: selecting the seventh of sixteen in 28 comparisons

Jonathan Cremer reports a comparison algorithm selecting the seventh-smallest of 16 distinct elements in at most 28 comparisons. Combined with a previously published lower bound, this determines the optimum as 28; companion certificates improve several other small selection bounds.

Sources for this record

What was already known

The reported interval for V₇(16) was 28–30. Dörrer and collaborators supplied the lower bound 28; Cremer contributes the matching upper bound. The eighth-of-sixteen case remains between 28 and 29.

AI involvement Not rated

The paper’s Use of AI section states that coding assistants implemented software and drafted proofs. Cremer chose the problem, directed the searches and revised the text; no exact model identity is inferred.

Coding assistants implemented searches and drafted proofs, but no retained selection-program discovery or essential mathematical idea is individually assigned to them.

Importance Modest

Closes one small exact-selection case by an explicit algorithm and improves other finite comparison bounds.

Limitations

The reported Lean proofs establish the new upper bounds and separate analytical lower-bound statements. The numerical lower bound 28 used for the exact optimum is prior computational work and is not recomputed in this project. The author’s independently implemented checker is not an outside researcher’s assessment. AIProofWatch has not run the search, certificate checker or Lean build.

Technical verification Formal

A completed rigorous check is documented for the scoped statement. Jonathan Cremer project: Lean kernel and leanchecker (reported): Existence of selection programs satisfying SelectsWithin for the seven new upper bounds, including V₇(16)≤28. The imported numerical lower bound V₇(16)≥28 is outside this check.

Formal checking

Author-reported Lean kernel and leanchecker checks; not rerun by AIProofWatch.

Checker
Jonathan Cremer project: Lean kernel and leanchecker (reported)
Scope
Existence of selection programs satisfying SelectsWithin for the seven new upper bounds, including V₇(16)≤28. The imported numerical lower bound V₇(16)≥28 is outside this check.
Basis
Reported by the linked checker
Evidence source

Checking a formal statement does not establish that it matches the original problem.

Human understanding Full

Named human researchers explain or reconstruct the scoped central mechanism in the cited paper/account; credit for that explanation is separate from technical checking. The paper’s Use of AI section states that coding assistants implemented software and drafted proofs. Cremer chose the problem, directed the searches and revised the text; no exact model identity is inferred.

Correction and publication history

2026-10-14 · publication

Primary-paper and pinned-artifact review, 14 October 2026. New scoped contribution; eligible for matching consented digests.

Read this published revision