Arithmetic traces and exact interfaces

Guarded-affine seams, recovery budgets, and capped continuation

A parity word presents more than one Collatz trajectory: it determines an affine action and one modular cylinder of starts. Cutting the word exposes an exact continuation map. The results below identify what that seam must remember, how much recovery a suffix can supply, and why several natural marginal-counting strategies do not yield contraction.

What these results do—and do not—say

The accelerated Collatz map is used here as a demanding calibration for finite presentation dynamics:

T(n)={n/2,n≡0(mod2),(3n+1)/2,n≡1(mod2). T(n)=\begin{cases} n/2,&n\equiv0\pmod2,\\ (3n+1)/2,&n\equiv1\pmod2. \end{cases}

The page proves exact finite-trace statements. It does not prove the Collatz conjecture, finiteness of paradoxical traces, or any claimed improvement to the recorded exponential candidate bound.

FPRD-D38 · guarded-affine presentation

One trace has four exact readouts

For a chronological parity wordw∈{0,1}kw\in\{0,1\}^k withs=∣w∣1s=|w|_1, iteration has the affine form

Tk(n)=3sn+cw2k. T^k(n)=\frac{3^s n+c_w}{2^k}.

Since 3s3^s is a unit modulo2k2^k, the starting values realizing that word form exactly one guard cylinder

n≡rw(mod2k),rw≡−cw3−s(mod2k). n\equiv r_w\pmod{2^k}, \qquad r_w\equiv-c_w3^{-s}\pmod{2^k}.

For example,7↦11↦17↦26↦137\mapsto11\mapsto17\mapsto26\mapsto13has word 11101110 and

T4(n)=27n+1916,n≡7(mod16). T^4(n)=\frac{27n+19}{16}, \qquad n\equiv7\pmod{16}.

The orbit list, word, affine action, and guard are presentations of the same finite event, but they preserve different information. At a fixed layer (K,S)(K,S), the additional readoutD=2K−3SD=2^K-3^S andΠ(w)=cw−Drw\Pi(w)=c_w-Dr_w measures descent at the least admissible representative. This definition concerns finite traces, not complete orbits.

FPRD-T138 · exact affine sewing

A cut transports every continuation guard

Let a prefix uu of lengthkk have weightpp, guardrur_u, and endpointyu=Tk(ru)y_u=T^k(r_u). Every start in its cylinder is ru+2kμr_u+2^k\mu, and the prefix sends it toyu+3pμy_u+3^p\mu.

If a suffix of horizonℓ\ell requires guardqq, then the admissible lift at the cut is the affine permutation

Fu(ℓ)(q)=3−p(q−yu)(mod2ℓ). F_u^{(\ell)}(q)=3^{-p}(q-y_u)\pmod{2^\ell}.

The proof is one modular substitution:yu+3pμ≡q(mod2ℓ)y_u+3^p\mu\equiv q\pmod{2^\ell}. Multiplication by the odd unit3−p3^{-p} gives one lift class. The endpoint records one realized input; the seam map records the prefix's action on every hypothetical continuation guard.

FPRD-T139 · exact interface demand

The complete seam profile needs linearly many bits

For the all-odd prefixesus=1su_s=1^s, the horizon profile is

Fus(ℓ)(q)=3−s(q+1)−1(mod2ℓ). F_{u_s}^{(\ell)}(q)=3^{-s}(q+1)-1\pmod{2^\ell}.

For ℓ≥3\ell\ge3, the orderord⁡2ℓ(3)=2ℓ−2\operatorname{ord}_{2^\ell}(3)=2^{\ell-2}gives that many distinct slopes and hence distinct complete seam maps. Naming the exact map therefore needs at leastℓ−2\ell-2 bits. Its slope and intercept can be stored inO(ℓ)O(\ell) bits, so the exact profile demand is Θ(ℓ)\Theta(\ell).

This counts exact continuation functions. A recognizer may merge prefixes whose full functions differ, so this is not an automata or language-recognition lower bound. Within a total trace budgetKK, this family supplies onlyℓ≤⌊log⁡2(K+1)⌋+2\ell\le\lfloor\log_2(K+1)\rfloor+2.

FPRD-T140 · exact recovery calculus

Recovery separates into disorder and seam lift

Fix a contracting layer(K,S)(K,S), soD=2K−3S>0D=2^K-3^S>0. Split a wordw=uzw=uz afterjj symbols. If the suffix has length L=K−jL=K-j and weightqq, its unique maximal affine constant is

CL,q+=2L−q(3q−2q). C^+_{L,q}=2^{L-q}(3^q-2^q).

Writeδz=CL,q+−cz≥0\delta_z=C^+_{L,q}-c_z\ge0for loss from that scalar maximizer, and letμz\mu_z be the least nonnegative seam lift satisfyingμz≡3−p(rz−yu)(mod2L)\mu_z\equiv3^{-p}(r_z-y_u)\pmod{2^L}. WithBu=3qyu+CL,q+−2LruB_u=3^qy_u+C^+_{L,q}-2^Lr_u, direct substitution gives

Π(uz)=2j(Bu−δz−Dμz). \Pi(uz)=2^j\bigl(B_u-\delta_z-D\mu_z\bigr).

The prefix budget must pay two nonnegative costs: local loss from the best fixed-weight word and modular misalignment at the cut. The scalar maximizer does not by itself guarantee a feasible continuation of the required length and weight.

FPRD-T141 · one-bit slot conservation

One presentation step injects child slots into parent slots

The prefix budget obeys the exact one-bit recurrence

2Bub=Bu−εbD−bGL,q, 2B_{ub}=B_u-\varepsilon_bD-bG_{L,q},

whereεb=bxor(yu mod 2)\varepsilon_b=b\mathbin{\mathrm{xor}}(y_u\bmod2)and the nonnegative odd-branch toll isGL,q=3q−1(2L−q−1)G_{L,q}=3^{q-1}(2^{L-q}-1)when that branch is feasible. ForSuslot={m:0≤m<2L, Dm≤Bu}S_u^{\mathrm{slot}}=\{m:0\le m<2^L,\ Dm\le B_u\}, send child slot ν\nu toεb+2ν\varepsilon_b+2\nu.

The two children land in disjoint parity classes of the parent, henceNu0slot+Nu1slot≤Nuslot. N^{\mathrm{slot}}_{u0}+N^{\mathrm{slot}}_{u1} \le N^{\mathrm{slot}}_u.

Equality can occur. The theorem is an additive conservation law, not a universal one-step contraction factor. Its abstract lift-slot count is also different from the lowering-capped count below.

FPRD-T142 · marginal no-gain theorem

More unconditional bands cannot improve the best envelope

Let t1≥⋯≥tL≥0t_1\ge\cdots\ge t_L\ge0be nested guard thresholds and letAi≥0A_i\ge0 be unconditional bounds on increasing disorder sublevels. The refined envelope is

ML=tL+∑i=2Lmin⁡(ti−1−ti,Ai)+A1. M_L=t_L+\sum_{i=2}^L\min(t_{i-1}-t_i,A_i)+A_1.

ML≥min⁡1≤i≤L(ti+Ai). M_L\ge\min_{1\le i\le L}(t_i+A_i).

The induction has two cases. PutΔ=tL−1−tL\Delta=t_{L-1}-t_L. IfΔ≤AL\Delta\le A_L, the last correction equals Δ\Deltaand ML=ML−1M_L=M_{L-1}. IfΔ>AL\Delta>A_L, discarding the earlier nonnegative corrections givesML≥tL+ALM_L\ge t_L+A_L. Together with the base case, this proves the claim.

The theorem closes only envelope arguments built from unconditional marginals. It does not rule out a genuinely joint guard–disorder estimate. A finite exhaustive audit over small integer thresholds was rerun as a falsification check; the displayed induction, not that enumeration, proves the theorem.

FPRD-T143 · capped continuation potential

Capacity and word supply meet at a bottleneck

Let NucapN_u^{\mathrm{cap}}bound admissible guard extensions, letWu=(Lq)W_u=\binom{L}{q} count remaining fixed-weight words, and define

mu=min⁡(Nucap,Wu),Ph=∑∣u∣=hmu. m_u=\min(N_u^{\mathrm{cap}},W_u), \qquad P_h=\sum_{|u|=h}m_u.

Child capacity is subadditive, while Pascal's identity makes word supply additive. ThereforePh+1≤PhP_{h+1}\le P_h; at full depth the cap equals the exact acceptance indicator. Locally, ifσu=Nucap−Nu0cap−Nu1cap\sigma_u=N_u^{\mathrm{cap}}-N_{u0}^{\mathrm{cap}}-N_{u1}^{\mathrm{cap}}and ℓu=mu−mu0−mu1\ell_u=m_u-m_{u0}-m_{u1}, then

2ℓu=σu+∣Nu0cap−Wu0∣+∣Nu1cap−Wu1∣−∣Nucap−Wu∣. 2\ell_u=\sigma_u +|N_{u0}^{\mathrm{cap}}-W_{u0}| +|N_{u1}^{\mathrm{cap}}-W_{u1}| -|N_u^{\mathrm{cap}}-W_u|.

This identity locates exact loss where arithmetic capacity and combinatorial continuation supply fail to align. It follows from2min⁡(x,y)=x+y−∣x−y∣2\min(x,y)=x+y-|x-y|.

Monotonicity is not multiplicative contraction. Capacity-one paths can preserve their only slot, andNcapN^{\mathrm{cap}} must not be identified with NslotN^{\mathrm{slot}}. The theorem has a written all-length proof but no independent all-length executable checker.

The remaining frontier is a correlation problem

Exact seams, recovery budgets, and monotone potentials organize finite traces. They do not determine which available guard slot receives which fixed-weight suffix or how much disorder that forced suffix carries. The unresolved question is therefore joint:

rw≤R,δw≤B−Drw. r_w\le R, \qquad \delta_w\le B-Dr_w.

FPRD-C03 records the honest alternatives: prove enough loss for the actual forced continuation, or construct an exact accepted-trace counterfamily. Larger marginal tables do not answer that question.

Read the counterfamilies, reproduced finite boundary, and open joint problem →

Evidence, provenance, and review status

The uniform results come from the preserved guarded-affine proof package and its pinned repository record. The affine, seam, and recovery checker previously reran 370,252 split instances; the budget checker reran 77,022 prefix nodes. A new finite audit exhaustively checked 532,700 small nested-threshold instances. These computations are regression and falsification evidence, not replacements for the written all-parameter proofs.

Read the complete source guide, failure ledger, and executable-evidence boundaries →