Kemeny Rank Aggregation for Three Voters
Is computing a Kemeny-optimal aggregate ranking NP-hard when the input consists of exactly three complete rankings? Hardness was known for every even $n \ge 4$; three voters was the minimal open case, and $n = 2$ is polynomial-time solvable.
Exact FrontierDelta
Scope and record
Occurred: Jul 28, 2026
Delta type: SOURCE CLAIM
Assumptions: VibeMathed verification: lean-verified. Publication: preprint. AI contribution: ai-discovered. Imported under CC BY 4.0.
Canonical aliases: Kemeny Rank Aggregation for Three Voters · Kemeny, 3 voters
Confidence: Not scored
Registry verification: lean verified · preprint · resolved
Attribution
VibeMathed
registry · event recorded by
Dominik Peters
human · human collaborator
GPT-5.6 Sol Ultra
model · ai model contributor · OpenAI / Anthropic
Claude Fable 5
model · ai model contributor · OpenAI / Anthropic
Lineage and corrections
This event attributed to Dominik Peters
This event attributed to Claude Fable 5
This event attributed to GPT-5.6 Sol Ultra