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Metadata
slug: separable-occupied-diagonal-lower-bound
bibkey: doughertyblissgalvanpolleyshuster2026enumerating
doi: null
url: https://arxiv.org/abs/2608.27583v1
triage: theorem
motivation_gids:
  - D5/S1/Words/Patterns/Separable/OccupiedComparison.actual_occupation_subsolution_comparison

Actual separable occupied-diagonal lower bound

Problem

For each positive length n, let M_n(e) count actual permutations avoiding 2413 and 3142, with no proper direct cut, and having at least one position j with j-sigma(j)=e. Count each permutation once. Put b=sqrt(2)-1, rho=b squared, a=1-b and O(e)=(2/a)sum_(n>=1)rho^n M_n(e). The target is a uniform positive constant c_* such that, for every integer e,

The empty permutation is excluded and the singleton is retained. The raw mass C=(a/2)O is distinct from the normalized occupation. This is an occupation obligation motivated by Dougherty-Bliss, Galvan, Polley and Shuster, Enumerating separable derangements, arXiv:2608.27583v1, Definitions 2, 5, 6 and equations (2)-(4), rather than a settlement of the paper’s full Conjecture 15. Issue 15063 registers the exact target.

Motivation

The actual comparison theorem proves summability of the literal shape weights, their total b, and critical kernel mass one half without extra premises. It also proves convergence of every actual occupied-count series and the box 0<=C(e)<=a/2. It proves reflection and the literal actual fixed-point equation, then bounds every vanishing nonnegative subsolution in that box by the actual occupied mass. The strict maximum argument uses the singleton loss weight. No recurrence-defined replacement class is used.

The critical convergence proof applies the native Schroder recurrence to the actual cardinalities. Nonnegative partial sums are bounded by b using a triangular convolution contained in the corresponding square. The Cauchy product then gives T=rho+rhoT+T squared. At rho=1-2b this is (T-b) squared=0, so T=b; retaining the singleton correction gives kernel mass b+rho/2=1/2.

Gap

The literal actual occupation equation and its finite minimum-cut event bridge are proved for both orientations, all natural lengths and every integer displacement. Write A(n,e) for the full occupied count, J(s,n,e) for the orientation-s indecomposable occupied count, and D(s,n,e) for the count with a proper orientation-s cut. Write U(n) and I(s,n) for whole-class cardinalities. For 0<i<n, the direct recurrence summand is

while the skew recurrence summand is

The sum of these respective summands over proper cuts is D(s,n,e). The actual minimum-cut equivalence transports the literal position/value hit predicate. Direct occupation is partitioned into left-hit/right-no-hit and right-hit, retaining the intersection correction. Skew occupation is a union of disjoint shifted events; the Fin bounds give a gap of two between their possible displacement ranges. Every actual shape is counted once.

The actual hit fibers also satisfy A(n,e)=J(s,n,e)+D(s,n,e) for every orientation, length and displacement. For n>=2 the native opposite-sign law gives D(s,n,e)=J(1-s,n,e). At length one J(s,1,e) is one at e=0 and zero elsewhere, with the genuine singleton retained in both orientations.

Inversion preserves avoidance and both proper-cut classes: a direct cut keeps its size, while a skew cut of size i becomes a skew cut of size n-i. It sends each hit displacement e to -e, so the actual indecomposable occupied counts and C are even. Every weighted finite-recurrence summand is nonnegative and bounded by twice the product of the corresponding shape weights. Their convergent joint sum permits the positive-length antidiagonal transport and interchange of the factor sums.

Let T be full occupied mass, P direct-decomposable occupied mass and V(x)=x squared/(h+x). The transported direct recurrence and partition give P=C(b-T)+(a/2)T and T=C+P. Hence T=2C-2V(C) and P=C-2V(C). The skew indecomposable occupied mass is delta+P, where delta is rho at zero and zero elsewhere. Substituting these identities into the transported skew recurrence, reflecting e to -e and averaging yields the literal occupation map. The delta terms select exactly length abs(e) for nonzero e and vanish at zero; the retained singleton gives forcing(0)=rho. Thus forall e, C(e)=occupationMap(C,e), with no extra equation premise.

The uniform power-kernel residual, integrated negative logarithmic residual, quadratic convolution bound and symbolic finite-region forcing bound remain needed to construct the positive global subsolution. Their Lean proofs and the uniform lower bound remain open.

The actual convergence, finite events, reflection and fixed-point equation are closed clauses of the comparison theorem. A closed production registration still needs faithful reconstruction and audit of its complete statement, including the unrestricted subsolution function and every conclusion clause. No production Reg source or validated registration is supplied. This unfinished audit is linked to issue 15063.

The singleton gives C(0)>=rho>0. The finite-support function w(0)=rho/2 and w(e)=0 for nonzero e lies in the comparison box, has finite positive superlevel sets and satisfies w<=occupationMap(w). The closed comparison therefore gives w<=C without an actual-equation premise. This positive finite-support application supplies no uniform all-integer lower bound.

Route

Construct a positive global subsolution for the literal occupation map in the same mass box, with finite positive superlevel sets. Uniform exterior residual estimates must dominate the quadratic loss; positive forcing on a finite core then permits a single positive scale. The closed actual fixed-point and comparison theorem supplies the final comparison. The required global logarithmic subsolution remains open.

Falsifier

Refuting the original bound requires showing that every positive proposed constant has an integer displacement violating that bound. Failure of a particular subsolution or residual estimate rejects that route alone. A finite positive-support example does not establish the uniform target. No refutation of the original target is supplied.

Evidence

The mathematical source is D5/S1/Words/Patterns/Separable/OccupiedComparison.lean, whose theorem actual_occupation_subsolution_comparison has the twelve closed clauses described above. Its axiom closure is propext, Classical.choice and Quot.sound. The finite recurrence clauses use the actual minimum-cut equivalence and preserve the singleton, intersection correction and skew displacement shifts. The actual equation is proved before the arbitrary subsolution comparison, with no equation antecedent.

Triage

The retained theorem supplies unconditional actual critical-series facts, the literal occupation fixed point and comparison for all subsolutions satisfying the stated box and vanishing conditions. It establishes neither the requested uniform lower bound nor Conjecture 15.

ASSUMED-UNVERIFIED

The bounded source search does not establish worldwide originality or first-publication priority. Ordinary analytic estimates using the paper’s cardinality asymptotic are not additional compiled suppliers in this unit. The complete source-selection and dependent-family escape audit remains unfinished, with its concrete missing evidence linked to issue 15063.