Keyboard shortcuts

Press ← or → to navigate between chapters

Press ? to show this help

Press Esc to hide this help


slug: nilforoushan-parvaresh-conjecture-8-1 bibkey: nilforoushanparvaresh2026kdecks doi: 10.48550/arXiv.2609.23106 url: https://arxiv.org/html/2609.23106v1 triage: theorem motivation_gids:

  • D5/S1/Words/Complexity/ExactDecks/Asymptotics/PositivePairExactDeckAsymptotics.actual_exactKDeckImage_weightedLyndon_isTheta

Nilforoushan-Parvaresh Conjecture 8.1

Problem

Conjecture 8.1 of Arman Nilforoushan and Farzad Parvaresh, Improved upper bound on the number of distinct k-decks for any k and alphabet size by counting the independent parameters, arXiv:2609.23106v1, states:

D_{q,k}(n) = Theta(n^{E_q(k)}) for every fixed q >= 2, k >= 1.

The paper defines D_{q,k}(n) as the number of distinct exact k-decks of length-n words over a q-letter alphabet and defines E_q(k) = sum_{j=1}^k j L_q(j) - 1, where L_q(j) is the number of actual length-j Lyndon words over that alphabet. Preregistration issue #9512 records this complete target, not one of the cases already proved in the source.

The formal target quantifies over an arbitrary finite linearly ordered type A, assumes exactly 2 <= Fintype.card A, takes every natural k with 1 <= k, and proves Real.IsTheta at Filter.atTop for the real-valued cardinality of exactKDeckImage A k n. Its exponent is weightedLyndonExponent A k - 1, with weightedLyndonExponent A k = sum_{i=0}^k i * actualLyndonCount A i and actualLyndonCount A i the cardinality of the subtype of actual Lyndon words of length i. The zero term vanishes, so this is the source exponent. There is no free proxy parameter and no extra hypothesis on n or on k.

Motivation

The source proves the general upper bound but leaves the matching lower bound open outside k=2 and the binary k=3 case. A complete resolution must therefore build many decks realized by actual positive words, preserve exact source length, and prove that the actual Lyndon coordinates determine the complete deck. Dimension counting or a free family of abstract parameters is not sufficient.

Gap

The paper’s affine-dimension calculation concerns relations generated by the subsequence-count product rule and explicitly distinguishes that calculation from realizability by actual decks. The formal gap is the general lower bound with the source exponent, together with an unconditional passage from Lyndon coordinates to all scattered counts. The existing frozen Vivion theorem is a different binomial-complexity refutation and supplies only reusable definitions and basic count identities.

The exact arXiv HTML, OpenAlex, and Crossref were checked on September 24, 2026. The arXiv source still labels the statement Conjecture 8.1, OpenAlex reported zero citing works, and Crossref’s first three exact-title results did not match a later proof. Semantic Scholar was rate-limited with HTTP 429 and is ASSUMED-UNVERIFIED. This bounded search does not support a universal absence or worldwide-priority claim.

Route

The route has 32 connected owners in nine natural subdomains. Recursive standard bracketing gives each actual Lyndon word an integral homogeneous polynomial with that word as leading monomial. Binary and indexed fixed-source schedule theorems retain occurrence identity, including duplicate factor occurrences, and show that an interleaving of nonincreasing Lyndon factors cannot exceed their concatenation.

The actual Magnus polynomial has scattered-count coefficients. Recursively generated positive pairs agree below their level, and their first possible difference is the corresponding standard-bracket direction. The full indexed family spans every standard bracket. Literal power substitution then scales the first unequal degree while preserving all lower degrees.

One selects as many independent actual positive-pair directions as there are actual Lyndon words. Direction-major, scale-minor digit blocks give equal-length positive words whose lower coefficients are fixed and whose degree-r coefficients encode a complete base-2^r digit array injectively. Combining these blocks over all degrees yields the weighted-Lyndon lower growth of the actual positive-word cutoff-Magnus ball.

Padding a ball representative to a fixed length loses only the one source-length degree of freedom and injects the construction into actual exact k-decks. Conversely, the overlap-infiltration identity and the indexed shuffle leading order prove unconditionally that agreement on actual Lyndon coordinates through k implies agreement on every scattered count through k. For a fixed deck length, erase one singleton Lyndon coordinate and recover it from total length; the remaining coordinates inject exact decks into the expected box. The lower and upper bounds are then the two directions of Real.IsTheta at atTop.

Falsifier

The resolution would fail if any formal object counted proxy directions rather than the actual Lyndon-word subtype, if duplicate indexed shuffles were identified and changed product multiplicities, if the positive-pair words did not share the asserted lengths and lower coefficients, if the multi-scale map were not injective, if padding changed the cutoff data, if exact-deck equality did not imply all shorter counts at a common source length, if Lyndon recovery required the conclusion as a guard, or if the erased singleton coordinate could not be recovered from the common total length. A proof only for a fixed alphabet, fixed k, sufficiently large k, or an abstract free parameter would not settle the registered statement.

Evidence

The formal settlement is D5/S1/Words/Complexity/ExactDecks/Asymptotics/PositivePairExactDeckAsymptotics.actual_exactKDeckImage_weightedLyndon_isTheta. It has exactly the finite-alphabet, linear-order, q >= 2, and k >= 1 hypotheses described above and no source-length hypothesis. Its conclusion is Real.IsTheta at Filter.atTop for the cardinality of the actual exactKDeckImage and the power with exponent weightedLyndonExponent k - 1.

The 31 preceding owners expose the standard bracket, occurrence-indexed shuffle order, actual Magnus coefficients, full-family span, central digits, positive-word-ball lower bound, exact-deck lower bound, and unconditional Lyndon-coordinate recovery used by the final proof. They are prerequisites of the single full-target settlement, not separate open-problem resolutions.

Triage

theorem. The result is a symbolic theorem for arbitrary finite linearly ordered alphabets and all positive deck lengths. It is not bounded enumeration, a numeric reduction, a certified finite instance, or a checker result.

ASSUMED-UNVERIFIED

Semantic Scholar was unavailable because of HTTP 429. The completed literature checks were bounded, and no claim is made that every later publication or private manuscript was searched. The typed resolution records this repository’s exact formal settlement of the cited statement; it does not by itself certify historical novelty or first-publication priority.