Lassak's Area Bound for Reduced Planar Bodies
Lassak conjectured that a reduced planar convex body of thickness $\Delta$ has area at most $(\pi/4)\Delta^2$, the value for the disc. False: an explicit reduced body of thickness $1$ has area $0.786215\ldots > \pi/4 = 0.785398\ldots$, given by a closed-form support function.
Exact FrontierDelta
Scope and record
Occurred: Jun 26, 2026
Delta type: SOURCE CLAIM
Assumptions: VibeMathed verification: site-confirmed. Publication: preprint. AI contribution: ai-assisted. Imported under CC BY 4.0.
Canonical aliases: Lassak's Area Bound for Reduced Planar Bodies · Lassak's conjecture
Confidence: Not scored
Registry verification: site confirmed · preprint · resolved
Attribution
VibeMathed
registry · event recorded by
Scott Duke Kominers
human · human collaborator
GPT-5.5 Pro
model · ai model contributor · OpenAI / Anthropic
Claude Opus 4.8
model · ai model contributor · OpenAI / Anthropic
Lineage and corrections
This event attributed to Scott Duke Kominers
This event attributed to Claude Opus 4.8
This event attributed to GPT-5.5 Pro