This repository is a working research package for settling the smooth-domain Reed--Solomon mutual correlated agreement (MCA) and proximity-list questions that arise in the Proximity Prize program.
See the related IACR ePrint paper.
MDS Paving Bounds for Reed--Solomon MCA is now IACR ePrint 2026/1463; the root-level RS_MCA_Paving_v9.2.tex and .pdf are the fixed basis for those unconditional results going forward.
experimental/proximity_prize_results_v4.tex and .pdf are the current top-level synthesis of the repository's unconditional Proximity Prize results. Use that paper as the compact map of proved affine-line staircases, complete smooth and exact rows, strong corridor safe edges, universal caps, deployed unsafe floors, high-agreement line/curve/list ledgers, theorem-ready local packets, and status-preserving nonclaims; it does not claim the unresolved deployed adjacent safe rows.
Visit the project's website.
The central theme is simple:
Smooth multiplicative Reed--Solomon domains do not appear to have a clean “up to capacity with negligible error” theorem. They have a corrected reserve theory. Any near-capacity theorem must clear explicit entropy, quotient, field-accounting, list-size, and MCA/line-decoding floors.
Pay-per-bit framing. If the Proximity Prize is allocated pro-rata by
soundness-gap bits, our current results are naturally scored by certified bits
above the 2^-128 target at an audited radius and denominator. Paper D v13.2 gives
the cleanest broad record: in its cap range it proves epsilon_mca > 2^-86,
which is at least 42 bits above the target throughout the full prize field
envelope. The strongest finite numerator record on the site is the
Cycle116/119 F_17^32 row, about 32.82 bits above target, while the exact
tangent-staircase gate gives a narrow but fully structural 6/7 transition. A
pay-per-bit rule would therefore reward both kinds of progress: larger certified
bit margins and, more importantly, certificates that push the unsafe radius
lower or close the interval for delta*_C(2^-128).
The repo is meant for people and AI agents who want to help turn that corrected theory into proofs, counterexamples, parameter certificates, and eventually protocol-grade statements.
The core repo consists of four main papers, one prize-facing theorem note, active
experimental threshold/final-resolution drafts, and two guide files. .tex versions
of the main papers are in tex/, experimental manuscripts are in
experimental/, and Python scripts for heuristics and certificates are in
scripts/ or experimental/scripts/.
| File | Short name | Role |
|---|---|---|
RS_disproof_v3.tex |
Paper A: no-slack obstruction | Refutes the unslacked, support-wise line-MCA reading of “up to capacity” for smooth multiplicative RS domains. Provides explicit lower-bound mechanisms and deployed-field obstructions. |
slackMCA_v4.tex |
Paper B: slack / quotient / entropy theory | Main theory paper. Builds the corrected reserve framework and now promotes the solved high-agreement line/list/curve boundary layer into the main theory. |
cs25_cap_v13_2.tex |
Paper D: two-sided cap, safe-side pincer, and certificate grammar | This is the main Proximity Prize submission reference. It keeps the self-contained cap route, promotes the v13.2 unsafe-frontier repairs, adds the safe-side pincer, deployed-row two-sided intervals, map/rational smooth extensions, circle/genus-one transports, explicit witness machinery, optimized failure profile, and certificate grammar. |
snarks_v5.tex |
Paper C: SNARK ledger | Turns the corrected theory into a protocol-facing certificate and adds a theorem-backed high-agreement ledger compiler for line/list/curve coding numerators. |
towards-prize.tex |
Towards Prize: sparse threshold note | Compact prize-facing note. It packages the delta^* staircase viewpoint, deployed KoalaBear pincer, and the new sparse residual reduction emca = max(eca, sigma_C/q) into the current execution target. |
experimental/proximity_prize_results_v4.tex / .pdf |
Proximity Prize Results v4 | Current top unconditional-results synthesis. It assembles proved affine-line MCA staircases, complete target compilers, explicit smooth/additive/separating/saturated rows, strong corridor safe-side bounds, post-Johnson certificates, universal unsafe caps, deployed unsafe floors, exact high-agreement line/curve/list ledgers, and theorem-ready collaborative packets while keeping conditional adjacent-row claims out of theorem statements. |
experimental/rs_mca_thresholds.tex |
Reed--Solomon MCA Thresholds | Current coherent exact-threshold draft. It packages exact deep/quadratic MCA staircases, CA/sparse decomposition, certified Proth prime rows at all four official rates, smooth/circle transports, and target-aware certificate formulas. |
experimental/grande_finale.tex |
Grande Finale v4 | Active experimental final-resolution spine. It keeps the profile/Q/Sidon/Fourier compiler material and adds the order-32 rank route, rational-atom extraction/coherence, owner localization, spread-core incidence bounds, and the current row-sharp completion problems. |
RS_MCA_Paving_v9.2.tex / RS_MCA_Paving_v9.2.pdf |
MDS Paving Bounds for Reed--Solomon MCA | Root-level fixed basis for unconditional paving results; this is IACR ePrint 2026/1463. Use it as a stable source for shortening, MDS-circuit, exact finite, exponential-budget, and conditional Sidon-to-flatness results. |
archived/asymptotic_rs_mca*.tex |
Archived asymptotic predecessors | Historical provenance for the compact/frontiers asymptotic drafts. Use for comparison only; new proof work should cite Grande Finale v4 or the exact-threshold draft. |
README.md |
Repo overview | Explains what the papers do, how they depend on each other, and what the project is trying to prove. |
AGENTS.md |
Research-agent guide | Gives AI agents and new contributors a prioritized list of proof targets, toy cases, scripts, and “do not confuse these” rules. |
The paper-letter order follows the internal blueprint: A = no-slack, B = slack theory, C = SNARK ledger, D = universal cap. The logical reading order is usually A → B → D → C.
Let C = RS[F, D, k], where D is a smooth multiplicative domain, usually a subgroup or multiplicative coset of power-of-two order n, and rho = k/n is one of
rho in {1/2, 1/4, 1/8, 1/16}.
The Proximity Prize regime asks for sharp thresholds near capacity, especially for target error
epsilon* = 2^-128,
k <= 2^40,
|F| < 2^256.
There are two linked threshold problems.
- MCA / correlated-agreement threshold. Determine how close the radius
deltacan get to1 - rhowhile the MCA error remains negligible. - Interleaved-list threshold. Determine how close
deltacan get to1 - rhowhile the relevant interleaved list size is at most a negligible fraction of the challenge field.
The prize-facing metric is the radius threshold, not the largest displayed
error margin. For target epsilon* = 2^-128, the object to determine is
delta*_C(epsilon*) = sup { delta : epsilon_mca(C, delta) <= epsilon* }.
Large error at a large radius is useful only as an auditable crossing
certificate. A barely-supercritical certificate at a smaller radius is more
important. Equivalently, on the integer agreement grid a = (1-delta)n, if
B_mca(a) denotes the number of MCA-bad line parameters at agreement at least
a, and B* = floor(epsilon* q_line) is the exact integer budget, the ideal
certificate is an adjacent staircase:
B_mca(a0) > B*,
B_mca(a0+1) <= B*.
Such a pair pins delta*_C(epsilon*) to one integer agreement step. The
leaderboard and submission notes should therefore rank results primarily by the
smallest certified unsafe radius, or by the tightest proven interval for
delta*_C(2^-128), with error size used as supporting evidence.
For the deployed KoalaBear sextic MCA row, the best current deployed unsafe edge is
delta = 981105/2097152 ~= 0.4678273,
unsafe agreement a0 = 1116047.
The remaining task is to close the adjacent band below that edge, ideally by
proving the first safe agreement 1116048 with an exact upper ledger.
The active experimental program now splits this into two proof problems:
-
Finite deployed one-step resolution. For each deployed row, prove an adjacent certificate
U(a0+1) <= B* < L(a0), whereLis the exact unsafe staircase,Uis the complete safe upper ledger, andB*is the integer challenge budget. The unsafe side is supplied by exact certificate claims in Paper D v13.2 and Grande Finale v4; the adjacent safe side still needs exact constants for the complete upper ledger. -
Asymptotic frontier resolution. Prove or refute the entropy-subfield envelope
delta*_C(epsilon*) = 1 - rho - g*(rho, log2 |B|) + o(1).The current coherent exact-threshold draft is
experimental/rs_mca_thresholds.tex; the active final-resolution spine isexperimental/grande_finale.tex. The archived asymptotic drafts are provenance only. The remaining hard inputs are: row-sharp finite Q / prefix max-fiber certificates; exhaustive first-match atlas and residual chart coverage; Sidon/Fourier payment or equivalent effective-imageMI+MA; residual ray compiler for higher-dimensional balanced cores; exact extension and quotient payments; and one summed integer certificate for each adjacent deployed row.
These are protocol-relevant because many proximity/SNARK reductions have a soundness term schematically like
MCA_error(C, delta) + |interleaved_list(C, delta)| / |challenge field| + query_error.
A list theorem alone is not enough unless it is connected to the exact MCA, CA, line-decoding, or curve-MCA quantity used by the protocol.
The old hoped-for statement was roughly:
Smooth-domain Reed--Solomon codes should behave well all the way up to capacity, provided the field is large enough.
The corrected picture is:
Smooth-domain Reed--Solomon codes have explicit near-capacity obstruction floors. A positive theorem must work at radius
1 - rho - eta, whereetaclears every known floor and every protocol ledger.
The ledgers that must be separated are:
- Generated-field entropy. The list/locator entropy denominator is the field generated by the domain and the received word, not automatically the large extension challenge field.
- Quotient-core obstructions. Smooth domains have quotient fibers. If
kandnalign with large quotient scales, large lists or bad slopes can appear. - Locator-fiber list size. Base-code locator fibers must be bounded before they can be used in a protocol list budget.
- Interleaved list size. The protocol often consumes
|Lambda(Int(C, mu), delta)|, not merely the base-code list size. - Challenge-field division. The list term is divided by the field in which the verifier samples the relevant challenge. Do not silently replace this by a larger or smaller field.
- MCA / CA / line-decoding / curve-MCA. These are related but not interchangeable without a theorem.
- Known failure ladders and universal caps. Some gaps are ruled out by explicit lower bounds or by the universal cap.
The current public paper set is A v3, B v4, D v13.2, C v5, plus the compact towards-prize threshold note. The version changes matter for the website and scanner as follows:
- Paper B v4 promotes the high-agreement tangent/list/curve boundary layer
from experimental notes into the main theory. Public tangent and
interleaved-list high-agreement rows should now cite
slackMCA_v4.texwhen they use this theorem package. - Paper D v13.2 is the main Proximity Prize submission reference. It keeps the headline universal MCA cap self-contained, promotes the corrected identity-prefix unsafe frontier, adds a two-sided threshold sandwich, proves the deep-regime safe theorem and MCA-from-CA pincer, extends the cap machinery to map/rational smooth domains, and packages deployed-row claims in certificate grammar. Auditing this paper is currently the main project focus.
- Paper C v5 adds the theorem-backed high-agreement ledger compiler for protocol-facing line/list/curve numerator accounting. It changes certificate packaging and denominator checks, not the mathematical value of the MCA cap rows.
towards-prize.texis a compact companion to Paper D, not the final submission authority. It does not add a new leaderboard row by itself. Its role is to state thedelta^*staircase problem compactly, record the deployed KoalaBear pincer, and reduce the remaining MCA task to the sparse residual layer plus CA/list certificates.experimental/rs_mca_thresholds.texis the current coherent exact-threshold draft. It should be read first for exact staircases, certified Proth rows, and certificate formulas.experimental/proximity_prize_results_v4.texis the current compact reference for the top unconditional Proximity Prize results. It is the best entry point for proved partial results before diving into the longer cap, threshold, paving, and Grande Finale sources, and now includes the corridor safe edges plus the high-agreement line/curve/list ledger.experimental/grande_finale.texis the active experimental final-resolution spine. It should now be read before the archived asymptotic drafts for profile-envelope, Sidon/Fourier, primitive-Q, Q-to-SP, quotient/remainder, and finite adjacent-row obligations.archived/asymptotic_rs_mca.texandarchived/asymptotic_rs_mca_frontiers.texare historical asymptotic predecessors. They remain useful for provenance and comparison, but they are no longer active proof targets.experimental/rs_mca_proximity_prize_status.mdis an experimental committee-facing status memo for the v13.2 frontier picture. It summarizes the entropy-subfield-envelope thesis, the current exact unsafe certificates, and the remaining(Q)/split-pencil conjectural safe side. Do not cite it as paper authority until the relevant claims are promoted into Paper D ortowards-prize.tex/cs25_cap_v13_2.texandexperimental/grande_finale.texare the current final-resolution sources. Paper D v13.2 is the active promoted cap ledger; Grande Finale v4 is the experimental sequel collecting the residual safe-side compiler, Sidon/Fourier payment, Q-to-SP, moving-root BC, and exact completion ledger. The former raw-v13 compact companion, v12 cap paper, and older asymptotic drafts are archived underarchived/.experimental/lean/towards_prize/is the Mathlib-based Lean track for the compact threshold note. Its entry point isTowardsPrize.lean; it should be reviewed and mapped theorem-by-theorem before any towards-prize claim is advertised as Lean-certified.
Paper A: no-slack obstruction
|
v
Paper B: slack / entropy / quotient-core theory
|\
| \__ Paper D: self-contained MCA universal cap
|
v
Paper C: SNARK/protocol ledger consuming B and D
RS_disproof_v3.tex is the base lower-bound paper.
It shows that the no-slack, support-wise line-MCA version of the up-to-capacity conjecture is false for smooth multiplicative RS domains. The organizing mechanism is the quotient locator identity: restricted sums in a smooth quotient subgroup produce many bad slopes for lines of the form
x^(k+a) + z x^k.
The paper gives explicit consequences over common smooth prime fields such as BabyBear, KoalaBear, 3*2^30+1, and Fermat-prime examples. Its role in the repo is to be the lower-bound oracle: if a proposed theorem contradicts Paper A’s obstruction intervals, the theorem is false or missing a reserve hypothesis.
slackMCA_v4.tex is the main theory paper.
It generalizes the obstruction into a corrected positive/negative theory. It separates:
- generated-field entropy floors,
- quotient-core list obstructions,
- characteristic-zero rigidity and finite-field collision sieves,
- exact slack bad-slope calculus,
- dyadic descent and failure ladders,
- tangent and quotient-periodic MCA floors,
- residue-line normal forms,
- local-limit conjectures for list decoding and MCA.
Version v4 additionally closes the theorem-backed high-agreement boundary layer:
affine/projective line and no-loss CA numerators are exact in the tangent range,
interleaved lists are unique in their high-agreement range, and degree-d
finite power-curve ledgers have a proved upper envelope with split moving-root
exactness.
Paper B is where most new mathematics should land. It contains the theorem/conjecture shape for a corrected reserve theorem: not “up to capacity,” but “up to capacity minus every explicit floor.”
cs25_cap_v13_2.tex is the main Proximity Prize submission reference.
It keeps the self-contained universal MCA cap:
delta*_C(2^-128) <= 1 - rho - 2^-9 for rho in {1/2, 1/4, 1/8},
delta*_C(2^-128) <= 1 - rho - 2^-10 for rho = 1/16,
throughout the challenge range |F| < 2^256, with the stated smoothness/divisibility hypotheses. It gives error > 2^-86 uniformly and improves to > 2^-42 when |F| >= 2n.
Version v10 also contains the large-row first-grid cap. For the official
rates, once k is at least 127, 78, 58, 47 respectively and q>n, the first
closed grid point below capacity is already CA/MCA unsafe:
delta*_C(2^-128) <= 1 - rho - 1/n.
It also adds the current safe-side and certificate package: a deep-regime MCA safe theorem for all linear codes, a reduction from MCA to CA up to half the minimum distance, a self-contained half-Johnson CA bound, map-smooth and rational-smooth cap extensions, circle/genus-one transports, explicit witness machinery, an optimized failure profile, and finite certificate grammar v2.
Paper D supersedes the older internal cap in Paper B for final constants. Paper B keeps its native quotient-core cap because it explains the mechanism; Paper D v13.2 owns the current field-size-universal and two-sided cap package, and is the canonical source for final submission hypotheses, denominators, endpoint conventions, and proof status.
Version v13.2 supersedes v12 as the active draft. The main remaining work is audit: check the direct conversion/radius conventions, the optional BCIKS half-distance import, exact-integer certificate replay paths, the corrected identity-prefix unsafe-frontier rows, and the precise scope of the circle/genus-one model transfers.
snarks_v5.tex turns the corrected theory into a protocol-facing reserve certificate.
Its purpose is not to prove all missing MCA/list theorems. Its purpose is to prevent protocol analyses from mixing ledgers. In particular, it insists on distinguishing:
- base field vs generated field vs extension challenge field,
- implementation interleaving vs protocol list arity,
- base-code lists vs interleaved lists,
- CA vs MCA vs line-decoding vs curve-MCA,
- theorem-backed mode vs conjectural aggressive mode vs obstruction-audit mode.
Version v5 also adds the high-agreement ledger compiler: before invoking near-capacity conjectures, a protocol certificate can first check the exact line/list/curve numerator formulas in the small-radius theorem-backed range.
Paper C is the bridge from theory to systems. Once the missing local-limit and line/MCA statements are proved, Paper C should become a compiler from a code/domain tuple to a soundness certificate.
A rough status map:
| Topic | Current status |
|---|---|
| No-slack smooth-domain MCA obstruction | Proved in Paper A. |
| Explicit deployed-field lower-bound floors | Proved in Paper A/B for the stated regimes. |
| Quotient-core list obstructions | Proved in Paper B. |
| Exact slack calculus and many failure ladders | Proved in Paper B. |
| Universal field-size MCA cap | Proved in Paper D v13.2 under its printed divisor/binomial/subfield hypotheses. |
| First-grid, identity-prefix, and widened deployed-row MCA caps | Proved in Paper D v13.2 under its printed k, q>n, subfield, and certificate hypotheses; adjacent safe rows remain conditional. |
| Safe-side pincer and two-sided threshold sandwich | Proved self-contained up to the deep/half-Johnson edges; half-distance edge depends on the isolated BCIKS import. |
| Map/rational smooth, circle, and genus-one extensions | Proved in Paper D v13.2 under its stated model hypotheses; these are high-priority audit targets. |
| Certificate grammar and printed deployed certificates | Stated in Paper D v13.2; every "verified exactly" inequality should have a reproducible script or printed integer certificate. |
| Finite deployed adjacent threshold resolution | Open/conditional. Paper D v13.2 gives exact unsafe-side certificate claims; the adjacent safe side needs row-sharp Q, finite BC chart decomposition, and quotient/rung audits with constants. |
| Asymptotic entropy-subfield envelope | Active work is now split between experimental/rs_mca_thresholds.tex for the clean exact-threshold narrative and experimental/grande_finale.tex for the final-resolution spine. The archived asymptotic drafts are provenance only. Remaining hard inputs are row-sharp finite Q / prefix max-fiber certificates, exhaustive first-match and residual chart coverage, Sidon/Fourier or effective-image MI + MA, residual ray compiler, exact extension/quotient payments, and summed adjacent-row certificates. |
| Generated-field locator local limit above all floors | Open. Main list-side positive theorem target. |
| Corrected MCA / residue-line local limit above all floors | Open. Main MCA-side positive theorem target. |
| Line-decoding formulation of corrected MCA | Open. Important for protocols. |
| Extension-line MCA transfer | Open: prove a clean lift or find counterexamples. |
| Sharp interleaved-list constants near capacity | Open. Important for protocol soundness budgets. |
| Protocol-level FRI/WHIR ledger rewrites | Open engineering/proof task. |
| Certificate scanner | Prototype in experimental/notes/certificate_scanner/; emits JSON/Markdown A/B/C/D ledger reports. |
Good first contributions include:
- Proof audits. Verify individual lemmas and theorem dependencies in the four papers. Flag any hidden field-size, divisibility, monotonicity, or support-wise assumptions.
- Scripted certificates. Implement scanners for entropy reserve, quotient profiles, restricted sums, interleaved-list budgets, and challenge-field accounting.
- Toy-case exploration. Exhaust small fields/domains to discover or refute local-limit behavior.
- Paper D v13.2 audit. Check direct conversion/radius conventions, ABF normalization, the optional BCIKS import, exact-integer certificates, and circle/genus-one model transfers.
- Hankel certificates. Use
scripts/aperiodic_eliminant_schema.jsonto package exact-agreement eliminants, empty chart certificates, or named residual obstructions for the Paper D v13.2 certificate grammar. - Finite/asymptotic threshold work. Attack the five current hard inputs:
witness-exhaustive first-match atlas; image-scale
MI+MAor direct Sidon payment; residual ray compiler for higher-dimensional balanced cores; complete profile-envelope comparison with the target; and lower reserve/unsafe-side comparison. - New bounds. Attack the local-limit conjectures, interleaved-list constants, extension-line MCA, or domain-shattering alternatives.
- Protocol rewrites. Rewrite FRI, WHIR, or other proximity reductions in the exact ledger format of Paper C.
See AGENTS.md for a prioritized task list and suggested toy cases.
The first heuristic script is scripts/run_frontier.py, an EXPERIMENTAL Paper B frontier scanner. For each prime p passed on the command line, intended with 32 | p-1, it builds the order-32 multiplicative subgroup of F_p, uses a meet-in-the-middle subset enumeration at fixed l = 18, and records which elementary-symmetric fingerprints (e1, e2) are realized by l subgroup elements. Its coverage line measures how much of F_p^2 this restricted quotient-locator map hits and appends the result to frontier_results.txt; full coverage is evidence about quotient/restricted-sum frontier behavior, not a proof by itself. The script currently requires numpy and sympy.
The certificate scanner prototype lives in
experimental/notes/certificate_scanner/. It reads a row/config JSON and emits
both a machine-readable report and a Markdown audit for generated-field entropy,
exact-divisibility quotient profile, Paper D cap hypotheses, high-agreement
line/list/curve ledgers, and the combined protocol-ledger verdict. It is a
ledger-audit tool, not a proof of extension-line MCA, arbitrary-word locator
local limits, aperiodic Hankel-pencil packing, or deployed protocol soundness.
The aperiodic Hankel certificate schema lives at
scripts/aperiodic_eliminant_schema.json. It is for Paper D v13.2 certificate
packets: row and domain hash, exact agreement levels, removed tangent/quotient
ledgers, regular minors, pivot charts, eliminants, empty-chart proofs,
dimension-degree fallbacks, and named residual obstructions.
The broader intended script layer is:
scripts/
run_frontier.py # EXPERIMENTAL psi_2 restricted-subset frontier scan
entropy_margin.py # generated-field entropy reserve
quotient_profile.py # active quotient scales at actual (n, k, a)
restricted_sum_dp.py # restricted-sum / DSH verification certificates
locator_fiber_scan.py # small-field locator-fiber experiments
mca_slope_scan.py # small-field bad-slope / residue-line experiments
interleaved_budget.py # base/interleaved list-to-field soundness budget
certificate_emit.py # JSON + TeX certificate tables for Paper C
aperiodic_eliminant_schema.json
# Paper D v13.2 Hankel eliminant certificate schema
experimental/notes/certificate_scanner/
certificate_scanner.py # EXPERIMENTAL A/B/C/D + high-agreement ledger scanner
examples/*.json # reproducible row configs
outputs/*.report.{json,md} # replayable scanner outputs
A useful script should emit both human-readable output and a machine-checkable certificate. Hand-computed tables should eventually be replaced by script output.
Use these conventions when adding results:
rho = k/nis the rate.delta = 1 - rho - etais the proximity radius.etais the reserve/gap from capacity.q_genis the field generated by the domain/received-word data.q_lineis the field from which line or CA/MCA challenges are sampled.q_chalis the verifier challenge field; it may or may not equalq_line.muis protocol list arity.nuis implementation interleaving.Qprofis the quotient-profile obstruction ledger.
When in doubt, keep the fields separate. Most false near-capacity claims come from giving the same field-size credit to two different ledgers.
When editing the papers:
- Cite companion results with theorem/proposition numbers, not just “the companion proves.”
- Mark every result as proved, conditional, conjectural, experimental, or audit-only.
- Cite the main Paper D v13.2 MCA cap, safe-side pincer, and certificate grammar as the active Paper D package, under their printed hypotheses and audit caveats.
- Do not state an error-one result from Paper D’s cap; Paper D caps the threshold and gives a small certified failure probability, but the error-one-in-the-band problem remains open.
- Keep Paper D as the canonical reference for the final universal-cap constants.
- Keep Paper C as the canonical reference for protocol ledgers and field-accounting rules.
The goal is to settle the Proximity Prize MCA/list questions for smooth-domain Reed--Solomon codes in a way that is useful for proof systems.
A positive outcome would be a theorem-backed reserve certificate: given a domain, rate, field, interleaving, and protocol reduction, the repo can certify a near-capacity radius and soundness budget.
A negative outcome is also valuable: every obstruction becomes a new floor, a warning for protocol designers, or a reason to switch to folded/subspace-design codes, random/punctured domains, or domain-shattered constructions.
Either way, the aim is to replace folklore “near-capacity RS should work” claims with exact, checkable mathematics.
The current work was done with GPT-5.5 Pro and Claude Fable 5 and still needs proper revision. Human input is welcome.