Sallerk 2026 convex nonagon relations

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evidence/: Exact fixed-witness evidence for one convex E3 nonagon, with rational sign certificates and no tolerance-based acceptance.

nonagon_from_relations: One strictly convex nine-point witness with maximum distance multiplicity three at every vertex, with independently reviewed exact finite evidence.

sallerk_2026_convex_nonagon_relations: Source transcription of the coordinate, mirror and minimality claims, with version provenance and an explicit separation from local verification.

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sallerk, Erdős Problem 97 forum post 8669, 31 August 2026, 19:37 (timezone unspecified in the preserved record). Source post. The preserved post transcription identifies its version and retains its AI-assistance disclosure.

The post gives six coordinates for two rotation orbits and asserts an exact convex nonagon with maximum distance multiplicity three at every vertex. The source-owned selected finite witness supplies a positive-radical third orbit, an authored derivation and deterministic exact checks. The frozen finite result survived independent whole-claim review and distinct completed-record grading, retained in the review record. The finite result supplies no solution of the four-neighbor question.

The coordinates realize the three relations in Er87b, printed pp. 175–176, Fig. 5. That source prints no coordinates. The supplied coordinates are not identified as Danzer's original choice, and the local derivation does not reconstruct every part of the printed Reuleaux-triangle construction. This folder holds no copy of Er87b.

The post's degree-four, mirror-symmetry and minimum-size claims are separate qualified reports; completion uniqueness and alternate-root nonconvexity are review-side reports. None is certified by this finite witness check. In particular, the six-point exclusion needed for the asserted lower bound $n_3\geq7$ has not been inspected.

Bears on. Problem 97: an exact three-neighbor example, not a four-neighbor counterexample.