The a = 3 slice of two permutational Ramsey conjectures: R_dih(P3alt, K_b) = R_cyc(P3alt, K_b) = 2b − 1 for all b

For every integer b≥1, the dihedral and cyclic Ramsey numbers of the alternating 3-path versus K_b both equal 2b−1.

Sources for this record

What was already known

Damnjanović–Đorđević and Bašić and coauthors conjectured the relevant formulas; the cited Chvátal path–clique theorem supplies a general upper bound.

AI involvement AI-autonomous

The project reports that Claude autonomously produced the proof, scripts and Lean formalization after human initiation and operational supervision.

The repository explicitly reports autonomous Claude production; no evidence of substantive human mathematical direction was found.

Importance Notable

Resolves the conjectured a=3 slice for both symmetry classes if the upper-bound transfer holds.

Limitations

Lean checks the universal lower bound, and exact certificates cover selected finite cases. A complete check of the upper-bound transfer to these dihedral and cyclic statements is not documented.

Technical verification Partial

The lower bound is Lean checked and several finite instances have exact certificates. The universal upper bound is a cited theorem, with no documented complete check of its transfer to this dihedral/cyclic claim.

Independent checking

formal proof

Checker
Lean 4 kernel via project TheoremB.lean
Scope
lower bound for all b and Dih(3)=Sym(3)
Basis
Reported by the linked checker
Evidence source

Independent checking

exact SAT refutations and checked witnesses

Checker
kissat and drat-trim via project SAT package
Scope
dihedral cases b=2..7; Python covers b=3 upper bound
Basis
Reported by the linked checker
Evidence source

Human understanding Few

Default: no named human account explaining the proof is documented.

Correction and publication history

2026-10-18 · publication

Resolves the conjectured a=3 slice for both symmetry classes if the upper-bound transfer holds.

Read this published revision