RESEARCH / Focused target
Refutation of the complete original Jaco addition law
RELEASED FOUNDATIONS / PROPOSED CONNECTION
Research connections
All source anchors (1)
- D5/S3/ConceptDynamics/GraphColoring/JacoMaximumDegree.resultAbsent from this graph
Problem
The question
Kok, Fisher, Wilkens, Mabula and Mukungunugwa, Characteristics of Finite Jaco Graphs, J_n(1), n in N, arXiv:1404.0484v1, printed page 7, Theorem 2.10 (Conjectured), states:
For the Jaco Graphs J_n(1), J_m(1) with n>=3, m>=3, n!=m we have Delta(J_(n+m)(1))=Delta(J_n(1))+Delta(J_m(1)), if J_n(1) or J_m(1) has a unique Jaconian vertex; Delta(J_n(1))+Delta(J_m(1))+1 otherwise.
This quotation normalizes only mathematical typography. Printed page 11 explicitly asks: “Prove Theorem (conjectured) 2.10.” Definitions 1.1--1.4 and 1.7, printed page 2, give positive vertices, the recursion i<j<=2i-d^-(v_i), finite truncation, ordinary total degree, and Jaconian vertices as all maximizing vertices.
Write Delta_n=(jaco n).maxDegree and U(n) iff exactly one v in Vertex n has degree Delta_n. The complete claim is
$$ \forall n,m\in\mathbb N,\quad 3\le n\Rightarrow3\le m\Rightarrow n\ne m\Rightarrow \left[ ((U(n)\lor U(m))\Rightarrow\Delta_{n+m}=\Delta_n+\Delta_m) \land ((\neg U(n)\land\neg U(m))\Rightarrow\Delta_{n+m}=\Delta_n+\Delta_m+1) \right]. $$
Both branches and every admissible ordered pair are one assertion. OR is inclusive. Unique means a unique vertex within that graph, not a unique degree value across orders. The source's prime Jaconian designation alone does not imply this uniqueness.
Motivation
Our foothold
This is the explicit author-posed addition question. The existing exact recursive graph and its all-order degree suppliers permit a direct test without changing its carrier or treating a positive finite prefix as a proof.
Gap
Missing bridges
The primary TeX, PDF, definitions and open prompt authenticate this exact question. Bounded screens of arXiv:1506.06538v1, arXiv:1404.1714v1, arXiv:2507.16500v1, On Deg-centric Jaco Graphs (DOI 10.17654/0974165825048), an arXiv title query returning 18 records, and a public MathDB-backup manifest did not identify a specific complete resolution in the inspected passages. Live MathDB contents were not acquired; citation enumeration returned HTTP 429; Reflections on Jaco Graphs, the named domination research note and unindexed sources remain explicit gaps. Repository issue screening identified no matching old-addition settlement in its bounded inspected scope. These readings certify neither worldwide openness nor first-publication priority.
The exact event and both source-only forecasts were registered in issue #25870. The graph suppliers are prior results. No specific earlier full resolution is claimed absent beyond the inspected sources.
Route
Proposed approach
Reuse JacoDomPathDiameterRefutation.Vertex and jaco, the positive-label finite truncation of JacoExponentialDominationRefutation's recursive adjacency. JacoEndpointBeatty.endpoint_recurrence connects that array to the source recursion. Forgetting orientation preserves ordinary total degree because every unordered edge has exactly one forward arc.
JacoMaximumDegree.degree_formula gives $d_n(i)=\min(i,n-\lfloor(i+1)/\phi\rfloor)$, and its result gives $\Delta_n=\lfloor(n+2)/\phi\rfloor-1$ for every $n\ge2$. Here $\phi=(1+\sqrt5)/2$ and natural subtraction is used. Exact bounds $8/5<\phi<13/8$ yield the required floors. For $n=3$, the degrees on the entire carrier are $1,2,1$, so $v_2$ is the unique maximizing vertex and $\Delta_3=2$. The same supplier gives $\Delta_{11}=7$ and $\Delta_{14}=8$. At $(3,11)$ the first branch would require $8=2+7=9$. Thus the literal negation of the whole claim follows. No assertion about the otherwise branch at this pair is needed.
The values are prior published data in arXiv:2507.16500v1, Table 1.
Their exact derivation here is an application of existing suppliers, not a
new numerical discovery. Conservative classification is
proof_shape: bind-only, escape_witness: none,
admission_basis: open-problem-resolution for the complete original question.
There is one public theorem, result; local arithmetic facts are used in its
proof. No supplier is reproved and no companion theorem is claimed.
Falsifier
What would falsify this route
A mismatch in the positive-label source recursion, ordinary degree, within-graph uniqueness, either branch, inclusive OR or the universal ordered-pair domain invalidates the source correspondence. A contrary exact computation of the degrees of J_3 or the three maximum degrees would invalidate the proposed contradiction. The Lean proof discharges those finite numerical obligations through the original graph suppliers.
Evidence
Evidence to collect
The settling declaration is
D5/S3/ConceptDynamics/GraphColoring/JacoAdditionLawRefutation.result,
whose literal type is Not claim; claim has literal type Prop.
The owning Scribe attaches the typed Refuted resolution only to result,
using this dossier and the resolvable
kok2014finitejaco source note.
The full formula above includes both original branches and all admissible
orders. Source statement and attribution use CC BY 3.0; no executable code is copied from the article.
Current scoped compilation and declaration reports supply exact statement, input identities and accepted axiom evidence. The typed resolution is validated against current frozen membership and exact compiled declaration identity. Local validation does not establish remote publication or complete-delivery credit.
Triage
Scope assessment
The complete universal assertion is refuted by the pair (3,11). This does not assert that every pair fails or settle a corrected addition law. The existing degree formulas survive unchanged. A classification of pairs on which either addition identity holds is a separate unresolved question.
ASSUMED-UNVERIFIED
Unverified assumptions
Source-to-formal correspondence is a reading of the published definitions, not a kernel theorem about author intent. Literature coverage and priority remain bounded by the gaps above. Existing supplier audit limitations remain those disclosed at issue #25698; this refutation neither repairs nor asserts completion of those registrations. Remote publication and required remote checks remain outside this dossier.