Results and open questions

Claims

Browse definitions, theorems, conjectures, counterexamples, and open problems from across FPRD Lab. Each record includes its exact statement, supporting evidence, dependencies, limitations, and links to related papers.

902 indexed claims and results

Starting points

A suggested reading order
  1. 01

    Automata and formal languages · proof

    A direct scaffold for even palindromes

    Conditional on the complete Draft 5 Section 11.1 sequence contract, persistent receipts and simultaneous records give a direct finite-scaffold and PEG route with symbolic resource bounds.

  2. 02

    Automata and formal languages · mechanically checked

    Strict real-time multitape machines compile to scaffolds

    A mechanically checked construction turns each fixed-tape real-time machine step into one bounded persistent scaffold update.

  3. 03

    Automata and formal languages · informal proof

    Reversed real-time multitape languages sit properly inside PEG

    The transfer theorem and classical palindrome recognition together place even palindromes in PEG.

  4. 04

    Automata and formal languages · mechanically checked

    The scaffold-to-PEG direction is mechanically checked

    The full sufficient direction of the Loff–Moreira–Reis correspondence is formalized for finite scaffolding automata.

  5. 05

    Logic, semantics, and rewriting · proof

    Local moves generate final behavioral equivalence

    In the unary distance-one setting, detours, absorptions, garbage moves, and carrier slides connect exactly the histories with the same final behavior.

  6. 06

    Logic, semantics, and rewriting · proof

    Unary scaffold histories admit a finite coherent presentation

    A finite family of cubical and bounded critical cells generates all parallel paths inside a final behavioral fibre.

  7. 07

    Algebra and discrete mathematics · proof

    Explicit metric-group products on the half-line

    A nested readout transports bitwise XOR to group laws on the nonnegative reals whose product is also a metric.

  8. 08

    Algorithms and complexity · mechanically checked

    The direct GapCVP reduction reaches 1/30-hardness

    Independently checked parameter choices preserve the direct reduction while exposing a retained-architecture frontier at 1/28.

  9. 09

    Models of computation · informal proof

    Compact finite feasibility sews into one presentation

    Under the stated compactness hypotheses, feasibility through every observation horizon yields one uniform exact presentation.

  10. 10

    Models of computation · informal proof

    Escape modulus detects failure of exact sewing

    Bounded escape identifies membership in one compact resource core; unbounded escape records finite feasibility without uniform realization.

Browse by research area

All claims and evidence

902 records

Search by statement, research area, result type, or contribution assessment. Each row links to its proof or evidence, sources, dependencies, limitations, and open work.

55 of 902 entries

Stable ID and statementType and current statusContribution assessmentResearch area and topicProof or evidenceDependenciesSource and reviewNext action
FPRD-D38Fix the accelerated map T(n)=n/2T(n)=n/2 for even nn and T(n)=(3n+1)/2T(n)=(3n+1)/2 for odd nn. A guarded-affine trace records a chronological word w∈{0,1}kw\in\{0,1\}^k, its affine action Tk(n)=(3sn+cw)/2kT^k(n)=(3^s n+c_w)/2^k, its guard rw≡−cw3−s(mod2k)r_w\equiv-c_w3^{-s}\pmod{2^k}, and—at a fixed layer (K,S)(K,S)—D=2K−3SD=2^K-3^S and Π(w)=cw−Drw\Pi(w)=c_w-Dr_w.DefinitionFixed and self-contained; no Collatz-conjecture implicationEvidence and limits →Number theory and discrete dynamicsGuarded-affine trace dynamicsGuarded-affine presentation and worked traceNo recorded dependenciesGuarded-affine trace dynamics proof packageReviewed 2026-08-27No documented external or specialist review of this FPRD result is recorded.Compare the presentation vocabulary with the closest parity-vector and 2-adic literature before any novelty language.
FPRD-T138If a prefix uu has weight pp, endpoint yuy_u, multiplier a=3pa=3^p, and guard rur_u, then its exact horizon-ℓ\ell action on a suffix guard is the affine permutation Fu(ℓ)(q)=a−1(q−yu)(mod2ℓ)F_u^{(\ell)}(q)=a^{-1}(q-y_u)\pmod{2^\ell}.TheoremProved by direct modular substitution; internally auditedEvidence and limits →Number theory and discrete dynamicsGuarded-affine trace dynamicsExact affine sewing proofFPRD-D38Guarded-affine trace dynamics proof packageReviewed 2026-08-27No documented external or specialist review of this FPRD result is recorded.Compare the formulation with the closest parity-vector and 2-adic conjugacy literature before any novelty language.
FPRD-T139For every ℓ≥3\ell\ge3, the prefixes us=1su_s=1^s induce 2ℓ−22^{\ell-2} distinct exact horizon-ℓ\ell seam maps. Thus an interface naming the complete map on every suffix guard needs at least ℓ−2\ell-2 bits, while slope and intercept use O(ℓ)O(\ell) bits; exact seam-profile demand is Θ(ℓ)\Theta(\ell).Theorem · exact resource boundProved for the explicitly defined exact-profile interface; internally auditedEvidence and limits →Number theory and discrete dynamicsGuarded-affine trace dynamicsExact seam-profile demand proofFPRD-D38; FPRD-T138Guarded-affine trace dynamics proof packageReviewed 2026-08-27No documented external or specialist review of this FPRD result is recorded.Keep this exact-interface bound separate from recognition lower bounds; seek a closer comparator for the profile-count formulation.
FPRD-T140For a contracting layer (K,S)(K,S) and split w=uzw=uz after jj symbols, Π(uz)=2j(Bu−δz−Dμz)\Pi(uz)=2^j(B_u-\delta_z-D\mu_z), where δz≥0\delta_z\ge0 is loss from the best fixed-weight suffix and μz≥0\mu_z\ge0 is the modular seam lift.Theorem · exact decompositionProved algebraically and finitely corroborated; internally auditedEvidence and limits →Number theory and discrete dynamicsGuarded-affine trace dynamicsPrefix recovery calculus and proofFPRD-D38; FPRD-T138Guarded-affine trace dynamics proof packageReviewed 2026-08-27No documented external or specialist review of this FPRD result is recorded.Use the exact decomposition only with joint guard–disorder information; marginal counts have already failed to give contraction.
FPRD-T141Prefix budgets satisfy 2Bub=Bu−εbD−bGL,q2B_{ub}=B_u-\varepsilon_bD-bG_{L,q}. Sending a child slot ν\nu to the parent slot εb+2ν\varepsilon_b+2\nu gives disjoint parity images, so Nu0slot+Nu1slot≤NuslotN^{\mathrm{slot}}_{u0}+N^{\mathrm{slot}}_{u1}\le N^{\mathrm{slot}}_u and the level potential is nonincreasing.Theorem · conservation lawProved; equality cases refute uniform one-step contraction; internally auditedEvidence and limits →Number theory and discrete dynamicsGuarded-affine trace dynamicsOne-bit recurrence and slot proofFPRD-D38; FPRD-T140Guarded-affine trace dynamics proof packageReviewed 2026-08-27No documented external or specialist review of this FPRD result is recorded.Do not seek a universal one-step factor loss; any improvement must use block structure or a stronger joint statistic.
FPRD-T142If t1≥⋯≥tL≥0t_1\ge\cdots\ge t_L\ge0 are decreasing guard thresholds and Ai≥0A_i\ge0 are unconditional bounds for increasing disorder sublevels, then ML=tL+∑i=2Lmin⁡(ti−1−ti,Ai)+A1≥min⁡i(ti+Ai). M_L=t_L+\sum_{i=2}^L\min(t_{i-1}-t_i,A_i)+A_1 \ge\min_i(t_i+A_i). Theorem · no-gain obstructionProved by an elementary induction and internally audited; no external reviewEvidence and limits →Number theory and discrete dynamicsGuarded-affine trace dynamicsNested-threshold theorem and proofNonincreasing thresholds; Nonnegative unconditional sublevel boundsGuarded-affine trace dynamics proof packageReviewed 2026-08-27No documented external or specialist review of this FPRD result is recorded.Do not add more unconditional Ferrers bands; seek a statistic that retains the joint guard–disorder correlation.
FPRD-T143Let NucapN_u^{\mathrm{cap}} bound admissible guard extensions, Wu=(Lq)W_u=\binom{L}{q} count fixed-weight suffixes, mu=min⁡(Nucap,Wu)m_u=\min(N_u^{\mathrm{cap}},W_u), and Ph=∑∣u∣=hmuP_h=\sum_{|u|=h}m_u. Then the accepted count is at most Ph+1≤PhP_{h+1}\le P_h, with equality at full depth, and the local loss obeys the exact bottleneck identity recorded below.Theorem · capped potentialWritten all-length proof; internally audited; no independent checker for this theoremEvidence and limits →Number theory and discrete dynamicsGuarded-affine trace dynamicsLowering-capped potential proofFPRD-D38; FPRD-T140Guarded-affine trace dynamics proof packageReviewed 2026-08-27No documented external or specialist review of this FPRD result is recorded.Seek joint guard–disorder loss; the capped potential alone gives no uniform factor contraction.
FPRD-C03Determine whether the forced continuation admits an all-length joint estimate for rw≤R,δw≤B−Drw, r_w\le R,\qquad \delta_w\le B-Dr_w, strong enough to improve the leading candidate exponent, or instead construct an exact accepted-trace counterfamily showing that actual forced-suffix disorder can preserve exponential mass.Open problemOpen; marginal routes are closed and no exponent improvement is claimedEvidence and limits →Number theory and discrete dynamicsGuarded-affine trace dynamicsSurviving frontier and exact alternativesFPRD-T140; FPRD-T142; FPRD-T143; FPRD-FAIL-COLLATZ-LF5Guarded-affine trace dynamics proof packageReviewed 2026-08-27No documented external or specialist review of this FPRD result is recorded.Analyze the actual uniquely forced suffix, not another marginal capacity envelope or a larger finite enumeration.
FPRD-FAIL-COLLATZ-LF3The exact monotonicity Ph+1≤PhP_{h+1}\le P_h and its additive bottleneck-loss identity do not imply a uniform bound Ph+1≤ρPhP_{h+1}\le\rho P_h with ρ<1\rho<1; capacity-one paths can preserve their only slot.Failed approach · negative boundaryClosed as a universal contraction routeEvidence and limits →Number theory and discrete dynamicsGuarded-affine trace dynamicsWhy monotonicity supplies no universal rateFPRD-T143; FPRD-FAIL-COLLATZ-LF5Collatz post-freeze failure ledger · LF3Reviewed 2026-08-27No documented external or specialist review of this FPRD result is recorded.Use the monotone potential for pruning and exact accounting only; require a stronger joint statistic for rate loss.
FPRD-FAIL-COLLATZ-LF4At layer (K,S)=(27,17)(K,S)=(27,17) and depth h=14h=14, exact reconstruction gives 2,3212{,}321 live prefixes, all with capped multiplicity one, so P14=2,321P_{14}=2{,}321 and F14=0F_{14}=0; forced continuation therefore does not by itself mean that few traces survive.Computational finding · failed scarcity proxyIndependently reproduced with an exact-integer checkerEvidence and limits →Number theory and discrete dynamicsGuarded-affine trace dynamicsExact LF4 reconstruction and evidence boundaryFPRD-T143Collatz post-freeze failure ledger · LF4Reviewed 2026-08-27No documented external or specialist review of this FPRD result is recorded.Preserve the executable regression and avoid treating this finite row as an asymptotic contraction result.
FPRD-FAIL-COLLATZ-LF5For every fixed C>0C>0, there are 2γK−O(log⁡K)2^{\gamma K-O(\log K)} genuine fixed-weight-feasible capacity-one prefixes, with γ=(1−log⁡32)(1−log⁡2(3/2))=0.1531779921…, \gamma=(1-\log_3 2)(1-\log_2(3/2))=0.1531779921\ldots, that cross a Clog⁡2KC\log_2K block with zero attrition under maximal-completion capacity.Theorem · counterfamilyWritten all-length proof; critical-layer estimate has an external dependencyEvidence and limits →Number theory and discrete dynamicsGuarded-affine trace dynamicsForced-family obstruction and proof boundaryCritical-layer estimate h=Z+O(log K); FPRD-T143Collatz lowering-and-contraction supplement · Section 6Reviewed 2026-08-27No documented external or specialist review of this FPRD result is recorded.Move to actual forced-suffix disorder; do not seek a universal capacity-only contraction over logarithmic blocks.
FPRD-FAIL-COLLATZ-LF7The marginal cap mu=min⁡(Nucap,Wu)m_u=\min(N_u^{\mathrm{cap}},W_u) records how many guard slots and fixed-weight tails exist, but not which tail occupies which slot or its actual disorder; it is therefore insufficient by itself to resolve the forced-continuation frontier.Failed abstraction · limitationSubstantiated as a limitation; the replacement joint statistic remains openEvidence and limits →Number theory and discrete dynamicsGuarded-affine trace dynamicsWhy the marginal cap loses the matchingFPRD-T143; FPRD-FAIL-COLLATZ-LF5; FPRD-C03Collatz post-freeze failure ledger · LF7Reviewed 2026-08-27No documented external or specialist review of this FPRD result is recorded.Track the joint assignment of exact guards to actual forced suffix deficits.
FPRD-FAIL-COLLATZ-LF8The strongest preserved candidate estimate remains exponential, 20.34416K+o(K)2^{0.34416K+o(K)}; none of the guarded-affine, marginal-capacity, or forced-family results proves finiteness of paradoxical sequences, Terras's conjecture, or the Collatz conjecture.Nonclaim · scope boundaryExplicitly established as the program boundaryEvidence and limits →Number theory and discrete dynamicsGuarded-affine trace dynamicsExplicit no-Collatz boundaryFPRD-T142; FPRD-T143; FPRD-FAIL-COLLATZ-LF5; FPRD-C03Collatz post-freeze failure ledger · LF8Reviewed 2026-08-27No documented external or specialist review of this FPRD result is recorded.Preserve dormancy unless a concrete joint guard–disorder lemma, exact counterfamily, or external audit reopens the route.
FPRD-IC-O01Selfridge asked whether ∥2n∥=2n\lVert 2^n\rVert=2n for every nn, where ∥m∥\lVert m\rVert is the least number of ones needed to build mm using addition, multiplication, and parentheses.Recognized open problemOpen; the FPRD track proves only restricted expression-family resultsEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityProblem, scope, and current frontierNo recorded dependenciesSelfridge's integer-complexity question; current context in Konyagin--Oganesyan (2026)Reviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Keep the restricted track paused pending a new normal-form or effective-height theorem; more residue tables are not the current frontier, and unrestricted Selfridge remains open.
FPRD-IC-D01The active restricted grammar has value M[A(B+C)(D+E)+F]M[A(B+C)(D+E)+F], where displayed operands are positive (2,3)(2,3)-smooth constructions and all three displayed additions are paid. After cost-preserving normalization, gcd⁡(B,C)=gcd⁡(D,E)=1\gcd(B,C)=\gcd(D,E)=1, the inner equation is primitive, and a fork is proper when both inner sums are nonsmooth.Definition and cost-preserving normal formPrecisely stated and proved within the restricted grammarEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityGrammar and normalizationNo recorded dependenciesFPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Preserve the exact paid-atom cost and unit charges in every subsequent reduction.
FPRD-IC-T01Every normalized primitive proper fork 3a(B+C)(D+E)+2f3g=2N3^a(B+C)(D+E)+2^f3^g=2^N satisfies f≤2f\le2. Moreover the odd parts of the two nonsmooth inner sums have opposite values of the quadratic character χ(x)=+1\chi(x)=+1 for x≡1,3(mod8)x\equiv1,3\pmod8 and −1-1 for x≡5,7(mod8)x\equiv5,7\pmod8.Computer-assisted restricted theoremProved and independently reconstructed within FPRD LabEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityThin-branch theoremFPRD-IC-D01FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Use the restriction to keep all later attacks inside the surviving f=0,1,2 branches.
FPRD-IC-T02In the normalized g=0g=0, positive-type-I branch, the ladder 3aP=(22rx−1)/(2x+1)3^aP=(2^{2rx}-1)/(2^x+1) has no surviving canonical negative-character solution with r≥2r\ge2. The remaining r=1r=1 controls cost at least 2N+22N+2.Exact computer-assisted restricted theoremProved with complete periodic certificates and an independent evaluatorEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityCyclotomic ladder closureFPRD-IC-D01; Michael Bennett, Theorem 1.6, for inherited boundary equationsFPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Keep this branch closed unless a defect is found in a displayed periodic certificate.
FPRD-IC-T03The complete odd-NN, g=0g=0, positive-type-I branch of the normalized proper fork has no displayed expression of cost at most 2N−12N-1. Its only solution in the two nonsmooth canonical shapes is 7⋅73+1=297\cdot73+1=2^9, whose two presentations cost 2N+22N+2 and 2N+32N+3.Exact restricted branch theoremProved with congruence and primitive-divisor arguments; independently auditedEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityOdd-exponent branchFPRD-IC-D01; FPRD-IC-T02; Zsigmondy's theorem on one boundaryFPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Do not reopen the odd-N branch; concentrate on the surviving even-N families.
FPRD-IC-T04At the first even layer a=1a=1, all but two large-x residue families and one x=4 control lift are excluded. In the x=4 family, every positive solution of 3(4+3v)(1+16⋅3y)+1=2N3(4+3^v)(1+16\cdot3^y)+1=2^N must satisfy (v,y,N)≡(0,0,8)(mod(576,144,360))(v,y,N)\equiv(0,0,8)\pmod{(576,144,360)}, v3(2N−13)=min⁡(v,y)+1v_3(2^N-13)=\min(v,y)+1, and v+y>1070v+y>10^{70}.Exact restricted reduction and lower boundProved and independently audited as an intermediate reduction; the lift is closed by FPRD-IC-T05Evidence and limits →Number theory and discrete dynamicsSelfridge integer complexityEven-layer reductionFPRD-IC-D01; FPRD-IC-T01FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Retain the Hensel class as the input to FPRD-IC-T05; do not treat the x=4 lift as an active survivor.
FPRD-IC-T05The inherited a=1a=1, II2, x=4x=4 equation 3(4+3v)(1+16⋅3y)+1=2N3(4+3^v)(1+16\cdot3^y)+1=2^N has no positive solution. Its first 3-adic Hensel digit forces N≡3248(mod9720)N\equiv3248\pmod{9720}; modulo 1944119441, the right side is then 1581215812, while the nine possible left-side residues omit 1581215812.Exact computer-assisted restricted theoremProved by a finite nine-residue certificate and independently reconstructedEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityExceptional-lift closureFPRD-IC-T04FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Use FPRD-IC-T07 for the type-II2 continuation and concentrate on the remaining large-x type-II1 family.
FPRD-IC-T06Every remaining a=1a=1 large-x solution would already have displayed cost at most 2N−12N-1. The 2-adic gates force v≥55313581v\ge55313581 in II1 and v≥60254788v\ge60254788 in II2. In the II2 subbranch y<vy<v, y≥5y\ge5, an exact modulus-1944119441 quotient eliminates 17 of the 28 inherited classes for x(mod540)x\pmod{540}, leaving 11 necessary classes.Exact restricted reduction and partial branch theoremProved and independently audited as an intermediate reduction; II2 is closed by FPRD-IC-T07Evidence and limits →Number theory and discrete dynamicsSelfridge integer complexityLarge-x frontierFPRD-IC-D01; FPRD-IC-T05FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Retain the 17/11 split as the input to FPRD-IC-T07; do not treat the eleven classes as active survivors.
FPRD-IC-T07The large-x equation 3(4+3v)(1+2x3y)+1=2N3(4+3^v)(1+2^x3^y)+1=2^N has no solution under the inherited a=1a=1, type-II2 conditions. Modulo 7 forces 3∣y3\mid y; the cases y=2,4y=2,4 fall immediately and y=3y=3 falls modulo 73. For y≥5y\ge5, exact quotients modulo 1944119441, 64816481, and 1313 eliminate all 28 inherited classes for x(mod540)x\pmod{540}.Exact computer-assisted restricted branch theoremProved with displayed finite certificates and independently reconstructedEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityComplete type-II2 closureFPRD-IC-D01; FPRD-IC-T05; FPRD-IC-T06FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Use FPRD-IC-T08 for the type-II1 continuation; do not treat this family as an active survivor.
FPRD-IC-T08The last a=1a=1 type-II1 family 3(2+3v)(1+2x3y)+1=2N3(2+3^v)(1+2^x3^y)+1=2^N, with vv odd, N≡16(mod18)N\equiv16\pmod{18}, and xx in the sixteen inherited classes modulo 270270, has no solution. Modulo 77 forces (v,y)≡(3,0)(mod6)(v,y)\equiv(3,0)\pmod6; modulo 1313, the left residues are then {0,7}\{0,7\} and the right residues are {3,10}\{3,10\}. Together with the preceding canonical closures, this completes the full a=1a=1 layer of the active normalized branch.Exact elementary restricted layer theoremProved by two displayed residue quotients and independently reconstructedEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityComplete first-layer closureFPRD-IC-D01; FPRD-IC-T05; FPRD-IC-T07FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Use FPRD-IC-B01 and FPRD-IC-T09 for the first a=2 family; do not reopen a=1.
FPRD-IC-B01For the a=2a=2 type-I2 equation 9(1+4⋅3v)(1+2⋅3y)+1=2N9(1+4\cdot3^v)(1+2\cdot3^y)+1=2^N, the coarse necessary classes v≡5(mod6)v\equiv5\pmod6, y≡0(mod6)y\equiv0\pmod6, and N≡6(mod36)N\equiv6\pmod{36} cannot be excluded by any finite collection of moduli coprime to 66: the formal boundary (v,y,N)=(−1,0,6)(v,y,N)=(-1,0,6) supplies compatible residues. The sharper 3-adic condition N≡42N\equiv42 or 78(mod108)78\pmod{108} breaks this obstruction and enables FPRD-IC-T09.Exact coarse-sieve method-boundary lemmaProved algebraically and checked on independent finite quotientsEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityNext-layer boundaryFPRD-IC-D01; FPRD-IC-T08FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Apply the 3-adic refinement before coprime order moduli; FPRD-IC-T09 shows that this closes the family.
FPRD-IC-T09The equation 9(1+4⋅3v)(1+2⋅3y)+1=2N9(1+4\cdot3^v)(1+2\cdot3^y)+1=2^N has no positive solution in the inherited a=2a=2 type-I2 branch. Modulo 77 and 1313 force v≡5(mod6)v\equiv5\pmod6, y≡0(mod6)y\equiv0\pmod6, and N≡6(mod36)N\equiv6\pmod{36}. An exact 3-adic comparison at 262^6 sharpens this to N≡42N\equiv42 or 78(mod108)78\pmod{108}. Modulo 271271, the resulting 25 left residues and 10 right residues are disjoint.Exact computer-assisted restricted branch theoremProved by displayed valuation and finite residue certificates; independently reconstructedEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityFirst a=2 family closureFPRD-IC-D01; FPRD-IC-T08; FPRD-IC-B01FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Use FPRD-IC-T10 for the final a=2 family; do not treat a=2 as an active survivor.
FPRD-IC-T10The remaining odd-exponent type-II2 equation 9(4+3v)(1+2x3y)+1=2N9(4+3^v)(1+2^x3^y)+1=2^N, with v,y≥1v,y\ge1 and x=v2(37+3v+2)x=v_2(37+3^{v+2}), has no solution. Modulo 7373 and the primary 2-adic gate force v≡5(mod12)v\equiv5\pmod{12} and (x,y)≡(1,3),(4,11),(7,7)(mod(9,12))(x,y)\equiv(1,3),(4,11),(7,7)\pmod{(9,12)}. Modulo 577577, where 3=21053=2^{105} and ord⁡577(2)=144\operatorname{ord}_{577}(2)=144, the required logarithm classes {1,4,7}(mod9)\{1,4,7\}\pmod9 are disjoint from the available classes {2,3,5,6}(mod9)\{2,3,5,6\}\pmod9. Together with the preceding canonical closures, this completes the a=2a=2 layer of the active normalized branch.Exact computer-assisted restricted layer theoremProved by displayed finite quotients and independently reconstructedEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityComplete second-layer closureFPRD-IC-D01; FPRD-IC-T09FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Use FPRD-IC-T11 for the a=3 entry table; do not reopen any entry with x at most 20.
FPRD-IC-T11In the active normalized branch 27P(1+2x3y)+1=2N27P(1+2^x3^y)+1=2^N, where PP is one of the four negative-character canonical factors, the two x=1x=1 families and every entry with 3≤x≤203\le x\le20 have no solution. Modulo 8181 gives N≡18N\equiv18 or 36(mod54)36\pmod{54}. The exact gate 27P+1≡2x3y(mod22x)27P+1\equiv2^x3^y\pmod{2^{2x}}, followed by a complete quotient modulo 7373, forces (x,y)≡(0,6),(3,2),(6,10)(mod(9,12))(x,y)\equiv(0,6),(3,2),(6,10)\pmod{(9,12)}. Exact finite covers eliminate x=3,6,9,12,15,18x=3,6,9,12,15,18. Hence every survivor has x≥21x\ge21 and 3∣x3\mid x; FPRD-IC-T12 closes this remote tail.Exact computer-assisted entry theorem and finite range closureProved by exact residue quotients and independently reconstructedEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityThird-layer entry theoremFPRD-IC-D01; FPRD-IC-T10FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Use FPRD-IC-T12 for the remote tail; do not reopen the a=3 positive-type-I entry table.
FPRD-IC-T12The remote branch 27P(1+2x3y)+1=2N27P(1+2^x3^y)+1=2^N, with x≥21x\ge21, 3∣x3\mid x, and PP one of the three surviving negative-character shapes, has no solution. Modulo 262657262657, where ord⁡(2)=27\operatorname{ord}(2)=27 and ord⁡(3)=14592\operatorname{ord}(3)=14592, the complete quotient leaves eight residue rows. Six fail modulo 77 and two fail modulo 1313. Together with FPRD-IC-T11, the complete a=3a=3 positive-type-I layer is empty.Exact computer-assisted restricted layer theoremProved by complete residue quotients and independently reconstructedEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityRemote third-layer closureFPRD-IC-D01; FPRD-IC-T11FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Treat positive type I as closed and move to the three low positive-type-II layers.
FPRD-IC-T13For every normalized primitive proper equation 3aPQ+1=2N3^aPQ+1=2^N with f=g=0f=g=0 and a≥4a\ge4, both canonical odd types Q=1+2x3yQ=1+2^x3^y and Q=2x+3yQ=2^x+3^y are impossible. The valuation identity gives 27∣N27\mid N, so modulo 7373 and 262657262657 both equations force Q=0Q=0. Every canonical negative factor PP is nonzero at both primes, while the complete exponent classes making Q=0Q=0 at the two primes have no simultaneous lift.Uniform exact computer-assisted restricted theoremProved by displayed subgroup and incompatible-lift certificatesEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityUniform high-layer obstructionFPRD-IC-D01; FPRD-IC-T01FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Do not resume exterior-layer induction above a=3; only the low positive-type-II layers remain in the g=0 branch.
FPRD-IC-T14Every normalized primitive proper f=g=0f=g=0 fork whose positive-character factor is 1+2x3y1+2^x3^y has displayed cost at least 2N2N. The cyclotomic and odd-NN theorems close a=0a=0; FPRD-IC-T08 and T10 close a=1,2a=1,2; FPRD-IC-T11 and T12 close a=3a=3; and FPRD-IC-T13 excludes every a≥4a\ge4.Restricted branch-closure corollaryProved by the cited exhaustive branch decompositionEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityComplete positive-type-I branchFPRD-IC-T02; FPRD-IC-T03; FPRD-IC-T08; FPRD-IC-T10; FPRD-IC-T12; FPRD-IC-T13FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Classify positive type II at a=1,2,3; the uniform theorem already supplies its high-layer boundary.
FPRD-IC-T15The normalized complementary family 27P(v)(2x+3y)+1=2N27P(v)(2^x+3^y)+1=2^N, with PP any canonical negative-character factor, has no solution. Its exact gate quotient contains 524288 states; relaxed but solution-preserving filters modulo 6481,257,73,7,1936481,257,73,7,193 leave respectively 16512,1268,390,124,016512,1268,390,124,0 states.Exact computer-assisted restricted layer theoremProved by a complete finite quotient and independently reconstructedEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityComplementary third-layer closureFPRD-IC-D01; FPRD-IC-T13FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Keep a=3 closed and concentrate on the exact residual quotient at a=1,2.
FPRD-IC-T16Every canonical solution of 3aP(v)(2x+3y)+1=2N3^aP(v)(2^x+3^y)+1=2^N with a∈{1,2,3}a\in\{1,2,3\} satisfies x≤10x\le10. A coupled quotient at the aligned primes 17,193,257,1228917,193,257,12289 leaves two high-gate rows modulo (512,512,6144,6144)(512,512,6144,6144); all 162 simultaneous lifts to periods (1536,1536,18432,18432)(1536,1536,18432,18432) fail modulo 7,13,73,97,5777,13,73,97,577.Uniform exact computer-assisted restricted theoremProved by coupled exponent quotients and independently reconstructedEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityUniform high-x obstructionFPRD-IC-D01; FPRD-IC-T13FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Do not resume a high-x search; the low-x quotient is now classified by FPRD-IC-T21.
FPRD-IC-T17Every remaining canonical solution of 3aP(v)(2x+3y)+1=2N3^aP(v)(2^x+3^y)+1=2^N, a∈{1,2,3}a\in\{1,2,3\}, lies in one of 21 displayed periodic rows modulo (v,y,N)=(1536,1536,18432)(v,y,N)=(1536,1536,18432), all at a=1,2a=1,2, with x∈{1,3,4,5,6,8}x\in\{1,3,4,5,6,8\}. These are necessary lift classes, not a classification.Exact residual-quotient theoremProved as a complete necessary quotient; every row is now classified by FPRD-IC-T21Evidence and limits →Number theory and discrete dynamicsSelfridge integer complexityTwenty-one residual lift classesFPRD-IC-T15; FPRD-IC-T16FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Use this finite quotient only as the input to the completed second-gate classification FPRD-IC-T21.
FPRD-IC-T18For the five residual rows of 9P(v)(64+3y)+1=2N9P(v)(64+3^y)+1=2^N inherited from FPRD-IC-T17, every solution satisfies v≡v0(mod36288000)v\equiv v_0\pmod{36288000}, y≡y0(mod36288000)y\equiv y_0\pmod{36288000}, and N≡12(mod48384000)N\equiv12\pmod{48384000}, where (v0,y0)(v_0,y_0) is its displayed boundary residue. Twelve simultaneous multiplicative-order quotients preserve exactly one lift of each row.Exact computer-assisted lift theoremProved and independently reconstructed; superseded as a frontier by FPRD-IC-T21Evidence and limits →Number theory and discrete dynamicsSelfridge integer complexityShared five-row boundary lockFPRD-IC-T17FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Retain as an exact intermediate theorem; do not extend this lock after FPRD-IC-T21 closes every nonboundary lift.
FPRD-IC-T19Every non-boundary solution in the five-row cluster of FPRD-IC-T18 satisfies v+y>26774635116096000v+y>26774635116096000 and N≥42436792629504012N\ge42436792629504012. Equivalently, after writing v=v0+36288000rv=v_0+36288000r, y=y0+36288000sy=y_0+36288000s, every solution has r+s>737837167r+s>737837167.Certified computer-assisted height theoremProved, but superseded by the complete nonboundary exclusion FPRD-IC-T21Evidence and limits →Number theory and discrete dynamicsSelfridge integer complexityOne-sided approximation barrierFPRD-IC-T18FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Do not extend the height sweep; the full second gate now excludes every lift to which this conditional bound applied.
FPRD-IC-T20Let F(v,y)=3aP(v)(2x+3y)+1F(v,y)=3^aP(v)(2^x+3^y)+1. Eleven rows of FPRD-IC-T17 have fixed valuation v2(F)=N0v_2(F)=N_0. In each of the other ten rows, the solutions of F(v,y)≡0(mod2e)F(v,y)\equiv0\pmod{2^e} form a one-dimensional Hensel graph: modulo Le=3⋅2e−2L_e=3\cdot2^{e-2}, there are exactly 2e−112^{e-11} states and projection to the vv-coordinate is bijective.Exact 2-adic lifting theoremProved by LTE and complete finite base checks; independently reconstructedEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityFull valuation gate and Hensel graphFPRD-IC-T17FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Reuse the full-side valuation gate before applying odd-prime quotients in the remaining fork orientations.
FPRD-IC-T21The normalized positive-type-II family 3aP(v)(2x+3y)+1=2N3^aP(v)(2^x+3^y)+1=2^N with a≥1a\ge1 has exactly ten canonical proper solutions, representing 3⋅5⋅17+1=283\cdot5\cdot17+1=2^8, 3⋅31⋅11+1=2103\cdot31\cdot11+1=2^{10}, 9⋅5⋅91+1=2129\cdot5\cdot91+1=2^{12}, and 9⋅13⋅35+1=2129\cdot13\cdot35+1=2^{12}. Every presentation costs at least 2N+42N+4.Exact computer-assisted restricted branch classificationProved from the complete residual quotient, full 2-adic gate, and one aligned prime; independently reconstructedEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityPositive-type-II classificationFPRD-IC-T13; FPRD-IC-T15; FPRD-IC-T16; FPRD-IC-T17; FPRD-IC-T20FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Move to the complementary a=0<g orientation and final 2-adic exponents f=1,2; do not reopen the classified tower.
FPRD-IC-T22Let RS+3g=2KRS+3^g=2^K be the reduced a=0<ga=0<g equation, with RR the negative-character canonical odd factor and SS the positive-character factor. Of the twelve possible canonical pairs modulo 24, the equation and the two Jacobi identities leave exactly (R,S;K,g)≡(5,1;1,1),(5,11;0,0),(7,1;0,0),(7,17;1,0),(13,1;0,1),(13,19;0,0)(mod(24,24;2,2))(R,S;K,g)\equiv(5,1;1,1),(5,11;0,0),(7,1;0,0),(7,17;1,0),(13,1;0,1),(13,19;0,0)\pmod{(24,24;2,2)}.Exact quadratic-residue restrictionProved elementarily and independently reconstructedEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityComplementary quadratic gateFPRD-IC-D01; FPRD-IC-T01FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Use the six-row gate before any 3-adic lifting or odd-prime quotient in the complementary orientation.
FPRD-IC-T23No normalized primitive proper solution with a=0<ga=0<g and f=2f=2 has v2(B+C)=v2(D+E)=1v_2(B+C)=v_2(D+E)=1. Indeed, the two odd parts must have opposite character and hence residues 55 and 17(mod24)17\pmod{24}, a pair excluded by FPRD-IC-T22.Exact restricted branch exclusionProved without exponent bounds; independently reconstructedEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityDouble-even branch exclusionFPRD-IC-T01; FPRD-IC-T22FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Classify the three surviving f=1 residue rows, beginning with their unique-minimum and tied 3-adic strata.
FPRD-IC-T24In every normalized primitive proper solution in the three complementary f=1f=1 residue rows, let (1+3b)/2(1+3^b)/2 be the odd part of the even factor and write the other factor as W=2h+2q3yW=2^h+2^q3^y. Then min⁡(b,y,g)=1+v3(K+1−h)\min(b,y,g)=1+v_3(K+1-h). All six tied-minimum strata whose leading 3-adic digit could cancel are impossible modulo 7 and 73.Exact valuation theorem and tied-stratum exclusionProved without exponent bounds; independently reconstructedEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityComplementary f=1 valuation lawFPRD-IC-T01; FPRD-IC-T22FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Combine this law with the f=2 valuation theorem and classify the first two minimum layers m=1,2.
FPRD-IC-T25In every normalized primitive proper solution in the complementary f=2f=2, split-(2,0)(2,0) branch, let Vb=(1+3b)/4V_b=(1+3^b)/4, where b≥3b\ge3 is odd, and write the other odd factor as W=2h+2q3yW=2^h+2^q3^y. Then min⁡(b,y,g)=1+v3(K+2−h)\min(b,y,g)=1+v_3(K+2-h). All ten tied-minimum strata whose leading 3-adic digit could cancel are impossible: nine by complete periods modulo 7 and 73, and the sole residual class by incompatible complete periods modulo 487 and 2593.Exact valuation theorem and tied-stratum exclusionProved without exponent bounds; independently reconstructedEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityComplementary f=2 valuation lawFPRD-IC-T01; FPRD-IC-T22FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Combine the f=1 and f=2 laws at minimum layers m=1,2, seeking a finite order-modulus cover before opening the f=0 rows.
FPRD-IC-T26In the normalized complementary f=1f=1 and split-(2,0)(2,0) f=2f=2 branches, impose m=min⁡(b,y,g)∈{1,2}m=\min(b,y,g)\in\{1,2\}. Of the 32 canonical minimum strata, nine are empty. Every state in the other 23 lies on one of 40 exact periodic lift graphs with common coordinate period P=20,652,025,680P=20{,}652{,}025{,}680. Twenty-nine graphs are rooted at seventeen proper harmless presentations and eleven at nine improper rational boundary identities. Every noncontrol proper solution therefore has output exponent N≥PN\ge P.Exact modular lift classification and height barrierProved without exponent bounds; independently reconstructedEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityComplementary minimum-layer lift lockFPRD-IC-T22; FPRD-IC-T24; FPRD-IC-T25FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Use the next 3-adic digit and an archimedean descent on the eleven boundary-rooted lift graphs; do not merely enlarge the order-modulus period.
FPRD-IC-T27In the normalized complementary f=1f=1 and split-(2,0)(2,0) f=2f=2 branches, every solution with m=min⁡(b,y,g)∈{1,2}m=\min(b,y,g)\in\{1,2\} is one of exactly seventeen explicit proper presentations. All seventeen cost at least 2N+62N+6. The eleven lift graphs rooted at improper rational identities are empty modulo 363^6; 26 control-rooted graphs freeze completely; and the remaining three reduce to 2K+1=11⋅3b+1732^{K+1}=11\cdot3^b+173 or 2K=3g+2952^K=3^g+295, whose nonzero lifts are excluded by Matveev's explicit lower bound and exact finite modular descent.Exact computer-assisted classificationProved with one classical linear-forms dependency; independently reconstructedEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityComplementary minimum-layer classificationFPRD-IC-T26; FPRD-IC-T24; FPRD-IC-T25FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Test whether the valuation period and an explicit linear-forms cutoff cross uniformly in m; otherwise open the complementary f=0 quotient.
FPRD-IC-T28The normalized complementary f=0,1,2f=0,1,2 family has only finitely many presentations. More precisely, its eight fixed factor-shape patterns contain at most 8exp⁡(7⋅3015)8\exp(7\cdot30^{15}) presentations in total. This is a direct corollary of the Evertse--Schlickewei--Schmidt bound for nondegenerate S-unit equations: after expansion and division by 2K+f2^{K+f}, five positive {2,3}\{2,3\}-units sum to one in a multiplicative group of rank at most six.Classical S-unit corollaryProved from an established theorem; not an effective height boundEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityUniform complementary finitenessFPRD-IC-D01FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Do not treat the solution-count bound as a height cutoff; obtain finite congruence quotients inside the remaining f=0 strata.
FPRD-IC-T29In the normalized complementary f=0f=0 branch RS+3g=2KRS+3^g=2^K, the quadratic gate leaves forty canonical factor placements and exactly twenty possible tied-minimum 3-adic cancellations. Only two can have v=y=gv=y=g. One has no solutions; the other has the unique solution (2+3)(1+8⋅3)+3=27(2+3)(1+8\cdot3)+3=2^7, whose displayed construction costs 18=2K+418=2K+4 ones.Exact elementary classification with finite residue certificateProved; independently reconstructedEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityComplementary f=0 triple-minimum classificationFPRD-IC-T22FPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Use FPRD-IC-T30 for the pair-minimum continuation; do not treat the eighteen strata as active survivors.
FPRD-IC-T30In the normalized complementary f=0f=0 branch RS+3g=2KRS+3^g=2^K, the eighteen pair-minimum strata whose first nonzero 3-adic digit can cancel contain exactly one solution, (4+3)(1+8⋅3)+34=28(4+3)(1+8\cdot3)+3^4=2^8, of displayed cost 29=2K+1329=2K+13. Together with FPRD-IC-T29, the entire exceptional cancellation locus consists of this control and (2+3)(1+8⋅3)+3=27(2+3)(1+8\cdot3)+3=2^7. Every other solution satisfies min⁡(v,y,g)=1+v3(K−r−u)\min(v,y,g)=1+v_3(K-r-u).Exact computer-assisted restricted theoremProved with complete finite quotients and independent reconstructionEvidence and limits →Number theory and discrete dynamicsSelfridge integer complexityComplementary f=0 cancellation closureFPRD-IC-T22; FPRD-IC-T29; LTEFPRD Selfridge integer-complexity research trackReviewed 2026-09-06No documented external or specialist review of these FPRD results is recorded.Pause layer-by-layer enumeration; reopen this branch only with an effective six-term reduction, a uniform freezing theorem, or another structural bridge.
FPRD-D39Fix b≥2b\ge2, Ab={0,…,b−1}A_b=\{0,\ldots,b-1\}, and n∈N0n\in\mathbb N_0. Write the canonical expansion n=∑i=0L−1aibin=\sum_{i=0}^{L-1}a_i b^i least-significant first, with L=1,a0=0L=1,a_0=0 for zero and aL−1≠0a_{L-1}\ne0 otherwise. Define rev⁡b(n)=∑iaibL−1−i\operatorname{rev}_b(n)=\sum_i a_i b^{L-1-i}, Tb(n)=n+rev⁡b(n)T_b(n)=n+\operatorname{rev}_b(n), ci=ai+aL−1−ic_i=a_i+a_{L-1-i}, γ0=0\gamma_0=0, si=(ci+γi) mod b∈Abs_i=(c_i+\gamma_i)\bmod b\in A_b, and γi+1=⌊(ci+γi)/b⌋\gamma_{i+1}=\lfloor(c_i+\gamma_i)/b\rfloor, retaining γL\gamma_L. Reversal-created leading zeroes do not change the integer. For canonical digits did_i of mm, Db(m)=#{i:di≠dM−1−i}D_b(m)=\#\{i:d_i\ne d_{M-1-i}\} counts ordered positions.DefinitionExact conventions reviewed; no theorem is embedded in this recordEvidence and limits →Number theory and discrete dynamicsNumber theory and discrete dynamicsDefinitions and conventionsNo recorded dependenciesFPRD Lab, Folded reverse-and-add and carry analysis (6 June 2026)Reviewed 2026-09-01No documented external or specialist review of this FPRD result is recorded.Find the smallest update-closed receipt that carries this one-step presentation across iteration.
FPRD-T144For each fixed b≥2b\ge2 and n∈N0n\in\mathbb N_0, the quantities in FPRD-D39 satisfy γi∈{0,1}\gamma_i\in\{0,1\} and Tb(n)=∑i=0L−1sibi+γLbLT_b(n)=\sum_{i=0}^{L-1}s_i b^i+\gamma_L b^L. After the symmetric fold supplies c0,…,cL−1c_0,\ldots,c_{L-1} in increasing digit index, the carry stage is a deterministic subsequential transducer over Cb={0,…,2b−2}C_b=\{0,\ldots,2b-2\}, with states {0,1}\{0,1\}, initial state 0, transition ⌊(c+γ)/b⌋\lfloor(c+\gamma)/b\rfloor, output (c+γ) mod b(c+\gamma)\bmod b, and terminal output 1 exactly when the final carry is 1. Within this folded one-step presentation, carry is the only orientation-dependent sequential state.Written theorem · fixed-base transducer familyProved on the public page; finite replay is corroboration, not proofEvidence and limits →Number theory and discrete dynamicsNumber theory and discrete dynamicsFolded carry theorem and proofFPRD-D39FPRD Lab, Folded reverse-and-add and carry analysis (6 June 2026)Reviewed 2026-09-01No documented external or specialist review of this FPRD result is recorded.Compare this elementary decomposition with prior reverse-and-add and finite-transducer literature before making any novelty claim.
FPRD-T145Under FPRD-T144, if γL=0\gamma_L=0 (equivalently, the step does not increase digit length), then for j=L−1−ij=L-1-i, si−sj≡γi−γj(modb)s_i-s_j\equiv\gamma_i-\gamma_j\pmod b and the integer γi−γj\gamma_i-\gamma_j lies in {−1,0,1}\{-1,0,1\}. This is a residue statement, not an absolute-distance bound; its residue-set corollary is nonrestrictive in bases 2 and 3.Written corollary · modular digit structureProved on the public page; finite replay is corroboration, not proofEvidence and limits →Number theory and discrete dynamicsNumber theory and discrete dynamicsMirrored carry law and proofFPRD-D39; FPRD-T144FPRD Lab, Folded reverse-and-add and carry analysis (6 June 2026)Reviewed 2026-09-01No documented external or specialist review of this FPRD result is recorded.Audit prior art, especially the documented observation that a palindromic output requires a palindromic carry pattern.
FPRD-T146A positive decimal input has a palindromic one-step reverse-and-add output exactly in one of two cases: every symmetric column sum is at most 99, or every sum lies in {0,11}\{0,11\} and the outer sum is 1111. On 1≤n≤1,000,0001\le n\le1{,}000{,}000, the two classes contain 151,250151{,}250 and 808808 inputs.Digit-structure theorem · reproduced finite censusGeneral classification proved; complete bounded census independently reproducedEvidence and limits →Number theory and discrete dynamicsNumber theory and discrete dynamicsClassification proof and bounded censusFPRD-D39; FPRD-T144Vaughn Suite, reverse-and-add carry note (16 September 2003); FPRD independent proof and censusReviewed 2026-09-01No documented external or specialist review of this FPRD result is recorded.Translate the decimal carry proof to general bases, treating the exceptional base-two growth pattern separately.
FPRD-T147For the outputs Tk(196)T^k(196), 1≤k≤4,0001\le k\le4{,}000, the reflection distance has minimum 22, its minimum normalized value is 4/334/33 at step 6868, and its mean normalized value over the 3,7713{,}771 outputs longer than 100100 digits is 0.6598039855420.659803985542.Reproduced bounded computational findingExact finite window independently replayed by two implementationsEvidence and limits →Number theory and discrete dynamicsNumber theory and discrete dynamicsReflection-distance observationFPRD-D39FPRD Lab, Folded reverse-and-add and carry analysis (6 June 2026)Reviewed 2026-09-01No documented external or specialist review of this FPRD result is recorded.Compare the same pinned statistic with convergent controls; do not extrapolate the finite lower bound to the infinite orbit.
FPRD-T148For the first 3,0003{,}000 transitions from 196196, the mean normalized shifted reflection distance is 0.4965587972440.496558797244 at shift 00 on the 1,7351{,}735 non-growing outputs and 0.4970666418240.497066641824 at shift +1+1 on the 1,2651{,}265 growing outputs; the mismatched shifts tested from −2-2 through +2+2 lie between 0.8840.884 and 0.8970.897.Reproduced bounded computational findingExact finite table independently replayed; universal shifted-axis identity unprovedEvidence and limits →Number theory and discrete dynamicsNumber theory and discrete dynamicsAxis-shift correctionFPRD-D39; FPRD-T145FPRD Lab, Folded reverse-and-add and carry analysis (6 June 2026)Reviewed 2026-09-01No documented external or specialist review of this FPRD result is recorded.Derive or refute an exact shifted-index identity; retain the present result as a finite table until then.
FPRD-T149Across the states Tk(196)T^k(196), 0≤k<4,0000\le k<4{,}000, every within-state decimal digit block through length 44 and every incoming-carry block through length 1212 occurs. The pinned replay gives carry-in density 0.4993661031130.499366103113, mirrored-digit mutual information 0.5635914756330.563591475633 bits, and mirrored carry-in mutual information 0.0000137957140.000013795714 bits.Reproduced bounded computational findingExact finite window and estimators independently replayedEvidence and limits →Number theory and discrete dynamicsNumber theory and discrete dynamicsRaw-complexity observationFPRD-D39; FPRD-T144FPRD Lab, Folded reverse-and-add and carry analysis (6 June 2026)Reviewed 2026-09-01No documented external or specialist review of this FPRD result is recorded.Add explicit control sequences under the same estimators before making comparative complexity claims.
FPRD-FAIL-LYCHREL-01The aperiodic-monotile substitution analogy was stopped because the sampled raw digit and carry streams showed none of the low-complexity hierarchy that route intended to exploit. This failure does not rule out conditional, finite-state, backward-preimage, or anti-concentration approaches.Important failed approachScope-corrected negative research recordEvidence and limits →Number theory and discrete dynamicsNumber theory and discrete dynamicsFailed-route boundaryFPRD-T149FPRD Lab, Folded reverse-and-add and carry analysis (6 June 2026)Reviewed 2026-09-01No documented external or specialist review of this FPRD result is recorded.Preserve the fold-and-carry representation while avoiding claims that raw block complexity excludes richer invariants.
FPRD-C04Does there exist a positive decimal integer whose reverse-and-add orbit never reaches a palindrome? In particular, does the orbit of 196196 avoid palindromes forever?Open problemOpen; no FPRD resolutionEvidence and limits →Number theory and discrete dynamicsNumber theory and discrete dynamicsOpen boundaryFPRD-D39FPRD Lab, Folded reverse-and-add and carry analysis (6 June 2026)Reviewed 2026-09-01No documented external or specialist review of this FPRD result is recorded.Pursue finite structural results and exact interfaces without treating bounded orbit searches or random-like statistics as an infinite proof.