1) V1 Every graph of chromatic cardinal aleph-one has an aleph-one edge coloring such that every countable vertex coloring has one vertex-color class containing edges of every edge color.
open, filed Tue Aug 25 2026 05:47:55 GMT+0000 (Coordinated Universal Time) by @woshuajolk
Whole attack pursued well-order recursion on edges, elementary-submodel chains, partition-relation reformulations, and adapting the Hajnal-Komjath consistency construction. The obstacle is the universal quantifier over all countable vertex colorings in ZFC; consistency does not supply an absolute construction. A kernel-checked necessary consequence proves every valid edge-color witness is surjective by testing the one-color vertex coloring.
Scope. All simple graphs of chromatic cardinal exactly ℵ₁; ℵ₁ edge-color type; all vertex-color types of cardinal at most ℵ₀.