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slug: elzein-mortada-saturated-packing-conjecture-refutation bibkey: elzein2026local doi: 10.48550/arXiv.2603.25113 url: https://arxiv.org/abs/2603.25113v1 triage: theorem motivation_gids:

  • D5/S3/Combinatorics/Graph/ElZeinMortadaSaturatedPackingRefutation.result

El Zein-Mortada Saturated Packing Refutation

Problem

El Zein and Mortada, arXiv:2603.25113v1, Conjecture 3, printed page 27, state: “Every 2-saturated subcubic graph is (1, 1, 2)-packing colorable.” A subcubic graph has maximum degree at most three. It is 2-saturated when each degree-three vertex has at most two degree-three neighbors. A (1,1,2)-packing coloring partitions the vertices into two independent classes and one class whose distinct vertices have distance greater than two. The printed conjecture contains no local-girth hypothesis.

Motivation

The frozen theorem D5/S3/Combinatorics/Graph/ElZeinMortadaSaturatedPackingRefutation.result settles the printed universal statement by an exact seven-vertex counterexample. It separates the statement as printed from the preceding discussion of local girth and makes no assertion about a strengthened local-girth version.

Gap

Issue 8799 records a bounded prior-resolution screen covering targeted arXiv and repository searches. It found the source at version 1 and a later paper resolving other conjectures from the same article, but no resolution of Conjecture 3 in the searched scope. The arXiv record lists only version 1. Google Scholar and exhaustive non-arXiv literature coverage are unverified.

Route

Use the connected graph with graph6 encoding FhcYG, vertices 0 through 6, and edges 01, 04, 12, 16, 23, 34, 35, 45, and 56. Its degree sequence is [2,3,2,3,3,3,2]; its four degree-three vertices have respectively 0, 2, 2, and 2 degree-three neighbors, so the graph is subcubic and 2-saturated.

The triangle on vertices 3, 4, and 5 forces one of those vertices into the radius-two class. Every graph vertex is within distance two of each triangle vertex, so no other vertex can use that class. Deleting vertex 3, 4, or 5 leaves respectively the five-cycle 0-1-6-5-4-0, 1-2-3-5-6-1, or 0-1-2-3-4-0. The remaining vertices cannot be divided between the two independent classes.

Falsifier

An omitted edge, an incorrect degree or saturation computation, a vertex more than distance two from a triangle vertex, or a two-coloring of one of the listed five-cycles would invalidate the counterexample. A source restriction on local girth would define a different claim from the printed Conjecture 3: under the paper’s prose reading of g₃ (every degree-3 vertex has local girth at least four) this graph is excluded, since its degree-3 vertices have local girths 5, 3, 3, 3; under the paper’s displayed formula g₃(G) = max{g(v) : d_G(v) = 3} it has g₃ = 5 and is not excluded.

Evidence

The formal module defines the source predicates Subcubic, Saturated, and IsPacking112, the closed proposition claim, and the sole public theorem result : Not claim. The proof checks the graph hypotheses by kernel evaluation, derives the distance bounds from explicit walks, and exhausts the remaining finite color cases. Its Scribe theorem node binds the frozen result to this dossier with OpenProblemResolutionClaim(Refuted).

Triage

theorem; Tier 1 recent named external conjecture, preregistered in issue 8799 before the proof probe. The admission basis is open-problem-resolution; the conservative classification is proof_shape: bind-only with escape_witness: none. The computational use is a certified-instance with a typed refutes edge from result to claim.

ASSUMED-UNVERIFIED

Literature completeness is ASSUMED-UNVERIFIED: the bounded screen cannot exclude every prior resolution or establish publication priority. Source-to-Lean fidelity requires independent comparison with arXiv:2603.25113v1; the Lean kernel checks the formal statement and proof, not that prose correspondence. The typed resolution binding does not itself establish repository merge or external publication.