RESEARCH / Focused target
The original Jaco directed path-count equivalence
RELEASED FOUNDATIONS / PROPOSED CONNECTION
Research connections
All source anchors (1)
- D5/S3/ConceptDynamics/GraphColoring/JacoDirectedPathCount.resultAbsent from this graph
Problem
The question
Johan Kok, Paul Fisher, Bettina Wilkens, Mokhwetha Mabula and Vivian Mukungunugwa pose Proposition 4.4 in Section 4 of https://arxiv.org/abs/1404.1714v1. Its proof placeholder is “(Conjectured)”; the final list explicitly asks “[Open problem: Prove Proposition 4.4]”.
For every natural $k\geq7$ and every Fibonacci bracket index $i$ with $F_i<k\leq F_{i+1}$, the complete question is
$$ \bigl(d^+(v_{k-1})\ne d^+(v_k)\ \land\ d^+(v_k)\ne d^+(v_{k+1})\bigr) \quad\Longleftrightarrow\quad \bigl(\psi(v_{k-1})\ne\psi(v_k)\ \land\ \psi(v_k)\ne\psi(v_{k+1})\bigr). $$
The vertices have positive labels. An original directed arc goes from $v_h$ to $v_j$ exactly when $h<j$ and $j\leq2h-d^-(v_h)$. The degree is the infinite outdegree. Each $\psi(v_n)$ counts distinct shortest directed edge sequences from $v_1$ to $v_n$ in that endpoint's own induced finite truncation $J_n(1)$. Length counts edges. Both adjacent comparisons, the iff, the lower bound and all bracket indices are part of the claim.
Motivation
Our foothold
The source asks whether adjacent repetition of the infinite outdegrees exactly matches adjacent repetition of actual shortest-directed-path cardinalities. Resolving the full equivalence requires connecting the endpoint arithmetic to actual directed paths, including transitions between Fibonacci distance layers.
Gap
Missing bridges
The original source explicitly poses the question as open. The bounded
literature scope and access gaps are recorded in the source note
Library/Certificates/kok2014jaco.md. No whole-equivalent earlier answer
was authenticated in that scope. Matching MathDB bodies and some journal
or follow-up full texts remain unread; worldwide openness, absence of
earlier solutions, novelty and priority are unverified.
Route
Proposed approach
Every forward path stays between its endpoints. Decomposition by its last predecessor gives finiteness of the actual path sets; consecutive forward arcs give connectivity and hence positive shortest-path counts. The same endpoint bounds identify paths across larger truncations without changing their directed edge sequences or their lengths.
For each edge budget $l$, the reachable positive labels are exactly those at most $F_{l+2}$. The endpoint identities prove this by induction, yielding the exact shortest-distance threshold. Removing the final edge of a shortest path to a label $n$ in the layer $F_j<n\leq F_{j+1}$ gives a bijection with pairs consisting of a predecessor in $[\operatorname{beattyOut}(n),F_j]$ and an actual shortest path to it. Appending the unique final arc is the inverse. Thus the cardinality is a suffix sum of positive actual path counts.
Within one layer the next lower endpoint stays fixed or increases by one, so the sums agree exactly when that endpoint stays fixed. A separate Fibonacci-boundary argument handles the change of distance layer. Together these facts prove both adjacent comparisons in the original iff. The proof uses no converse of Proposition 4.3.
Falsifier
What would falsify this route
A source mismatch in direction, endpoint truncation, infinite outdegree, path distinctness, or a missing original quantifier would invalidate the source interpretation. A label $k\geq7$ with a valid Fibonacci bracket and unequal truth values for the two conjunctions would refute the stated mathematical event. A counterexample to the last-edge bijection, positivity or boundary argument would identify the corresponding proof obligation; finite computations alone cannot establish the universal iff.
Evidence
Evidence to collect
The complete result is
D5/S3/ConceptDynamics/GraphColoring/JacoDirectedPathCount.result : claim;
claim has type Prop and retains the full source event.
The typed Proved resolution is attached only to that result.
The public path_count_foundations and fibonacci_distance theorems
supply actual finite positive counts, truncation invariance and the
all-budget Fibonacci threshold. The existing Blueprint contains the
full source formulas and the mechanism of the count proof.
The admission basis is open-problem-resolution; the live
reachable_prefix proof also supplies substantive path-existence
content. Utility remains none. Supporting lemmas and the claim
definition are not separate external-problem resolutions.
Triage
Scope assessment
theorem. The complete original Proposition 4.4 is established by the
single result above.
What the settlement shows
The decisive structure is the actual final-edge bijection and its suffix sum of positive shortest-path cardinalities. Within each Fibonacci layer, moving the lower summation endpoint removes a positive term precisely when the count changes. At Fibonacci boundaries the proof separately establishes endpoint counts equal to one and the following counts at least two, so the layer transition is covered.
The internal adjacent-equality argument holds for every label $n\geq5$; the external result retains the published $k\geq7$ and every original Fibonacci-bracket index. This proof makes the source equivalence independent of the Proposition 4.3 converse. It establishes no correction of that converse and no additional consequence asserted elsewhere in the source. Analogous count laws for other Jaco functions or further source questions remain open.
ASSUMED-UNVERIFIED
Unverified assumptions
The identification with the author's terminology rests on the independently checked versioned source reading. It is not itself a Lean theorem about the paper. The bounded literature checks do not certify worldwide absence, novelty or publication priority.
The foundations registration has its validated certificate and current
binding. The distance registration remains unfinished with
IE-C050/source.roles, and the result registration remains unfinished
with IE-C050/source.selection_missing; neither has a current certificate.
These audit gaps are disclosed in
https://github.com/the-omega-institute/trureturing/issues/25912 under the
current linked-issue exception. Final independent reviews and remote
required CI are separate pending checks.