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The Divisible Rank-Three Case of the Kajitani–Ueno–Miyano Conjecture

Proves the divisible rank-three case: rank exactly three and ground-set size a multiple of three, with no restriction to simple, paving, representable or graphic matroids. The part not previously in the literature is the non-simple sub-case, since McGuinness had settled all paving matroids and a rank-three matroid is paving exactly when it has no parallel pairs. Combined with the coprime-case theorem of van den Heuvel and Thomasse, this covers every finite uniformly dense rank-three matroid. The conjecture remains open in higher rank.

Exact FrontierDelta

proved→proved

Scope and record

Occurred: Oct 29, 2026

Delta type: REGISTRY REVISION

Assumptions: VibeMathed verification: lean-verified. Publication: preprint. AI contribution: ai-discovered. VibeMathed editorial classifications, scores, notes, relations, and dataset structure are CC BY 4.0. Source statements and linked content retain their own rights.

Canonical aliases: The Divisible Rank-Three Case of the Kajitani–Ueno–Miyano Conjecture · Divisible rank-three KUM

Confidence: Not scored

Registry verification: lean verified · preprint · partial

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Attribution

VibeMathed
registry · event recorded by

GPT-5.6 Sol
model · ai model contributor · OpenAI

Claude Opus 5 (for some Lean formalization and paper write-up)
model · ai model contributor · Anthropic

Artifacts and verifiers

Compute record

No linked compute attempts recorded.

Lineage and corrections

Corrects The Divisible Rank-Three Case of the Kajitani–Ueno–Miyano Conjecture →

Supersedes The Divisible Rank-Three Case of the Kajitani–Ueno–Miyano Conjecture →

Lean repo evidence for this event

VibeMathed record: The Divisible Rank-Three Case of the Kajitani–Ueno–Miyano Conjecture evidence for this event

Archived repo evidence for this event

This event attributed to Claude Opus 5 (for some Lean formalization and paper write-up)

The Divisible Rank-Three Case of the Kajitani–Ueno–Miyano Conjecture parent of this event

The Divisible Rank-Three Case of the Kajitani–Ueno–Miyano Conjecture evidence for this event

This event attributed to GPT-5.6 Sol

Proves the divisible rank-three case: rank exactly three and ground-set size a multiple of three, with no restriction to simple, paving, representable or graphic matroids. The part not previously in the literature is the non-simple sub-case, since McGuinness had settled all paving matroids and a rank-three matroid is paving exactly when it has no parallel pairs. Combined with the coprime-case theorem of van den Heuvel and Thomasse, this covers every finite uniformly dense rank-three matroid. The conjecture remains open in higher rank. parent of this event

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