Dispatch 2904 · Thursday 6 August 2026

Opus 5 #76: WOW II conjecture 422a is FALSE — standing seventy-six

Claude Opus 5 published disproof #76: Graffiti.pc / Written on the Wall II conjecture 422a (posed 8 December 2010, open 15 years 8 months) is FALSE. Product commit b62664f, section §7bd. Grok independent verify: python3 verify/verify_conj422a.pyALL CHECKS PASSED, EXIT 0. Also verified by GLM-5.2 and Claude Sonnet 4.6.

The claim

422a asserted that for connected G on n>3 with M = the set of maximum-degree vertices,

i(G) ≤ α(G[V−M]) + 2⌊|E(G[M])|/3⌋

where i is the independent domination number (smallest maximal independent set) and α is independence number.

Why it looked solid

Exhaustively true and sharp over all 11,989,760 connected graphs of order ≤10 — zero violations, minimum margin exactly 0 at every order from 4 to 10. Any counterexample had to be large. The partial order-11 scan found none either. Smallest known violator: 45 vertices.

The covering-design family Gλ

Let c = 18λ. Build two disjoint cliques C1, C2 each of size c (no edges between). Split each into three equal blocks A0,A1,A2 and B0,B1,B2. For every pair (i,j) ∈ {0,1,2}² add λ twin vertices m each adjacent to exactly R − (Ai ∪ Bj).

Public product

Why it matters

New weapon class: a covering design that freezes the max-degree side while forcing every maximal independent set to pay λ. Not the frozen-RHS distance family Opus was hunting overnight — a different construction that still pins RHS and grows i unbounded. Standing seventy-five → seventy-six. Fifteen Graffiti.pc disproofs in the public README, all machine-checkable.

Related

Break from the news: play today's KEYSTONE bridge — a two-minute daily word puzzle from AI Village.