core/docs/adr/ADR-0251-reader-arc-recalibration-geometric-normalization-spike-proposal.md

ADR-0251: Reader-Arc Recalibration — Halt Bespoke-Per-Case Regex Work; Clean-Base Reset; Proposed Geometric Surface→Canonical Normalization Spike

Status: §§1–4 (the recalibration decision — halt, reset, debt eradication, knowledge preservation) are executed, verified by command, 2026-07-19. §5 (the geometric-normalization spike) is Proposed — awaiting ruling. This ADR does not authorize any build; §5 is a direction proposal only. Date: 2026-07-19 Deciders: Joshua Shay (ruling authority) + Claude (recalibration executor, this pass) Depends on: #77/#78/#79 (compare-multiplicative compiler tier + NEUTRAL_COUNT_VERBS positive-polarity allowlist — the foundations this recalibration preserves), ADR-0136 family (statement-layer corridor), ADR-0175 (calibrated attempt-and-eliminate learning — serving wrong=0 vs. sealed practice), ADR-0191 (candidate-graph completeness guard), ADR-0249 (reader→Hamiltonian compiler composition frontier), ADR-0250 (tier-2 multi-entity arithmetic) Related (for §5's building blocks): ADR-0239 (Conformal Procrustes / analogical versor search — the general primitive this spike would apply), ADR-0245 (CGA unification, mechanical sympathy and semantic rigor), ADR-0246 (§6 explicitly disclaims Smith-chart algebra — honored here, not re-litigated) Supersedes: feat/reader-inc2-caseband (PR #80) — abandoned, not merged Companion docs: docs/research/reader-arc-recalibration-preserved-knowledge-2026-07-19.md, docs/research/0148-first-conversion-proof.md, docs/research/reader-arc-overfit-inventory-2026-07-19.md

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1. Context — why bespoke-per-case regex work is being halted

The GSM8K math reader (generate/math_candidate_parser.py, generate/recognizer_match.py, generate/recognizer_anchor_inject.py, generate/math_roundtrip.py, generate/math_candidate_graph.py) has advanced case-by-case: each new held-out case that needed a new surface form got a new, narrow regex tailored to that case's exact wording. This has produced real, wrong=0-safe progress (the #77/#78/ #79 compiler tier and positive-polarity substrate are sound and stay on main), but the shape of the growth is overfitting-shaped: one bespoke pattern per case does not generalize, and the inventory in §4 shows the pattern accumulating.

feat/reader-inc2-caseband (PR #80) is the branch that surfaced this concretely. It pursued case 0148 (the first real held-out conversion of this arc) and, per the PR's own review thread, succeeded at the narrow goal — report.json shows exactly one case flipped (0148: refused → correct), correct 5→6, wrong=0 held — but introduced debt in the process:

1. A shared grounding primitive was loosened fail-open. _token_in() in generate/math_roundtrip.py — used by every candidate's roundtrip-admissibility check, not just mass-noun ones — was widened to accept a multi-word phrase whenever all of its component words appear anywhere in the source's token set (order- and position-independent), rather than requiring the phrase to be a contiguous substring. That weakens a shared safety gate to admit one family. This is the same "don't loosen a shared gate to admit one case" failure the #77 split was already built to avoid.
2. A committed "proof" artifact was left empty. docs/research/0148-first-conversion-proof.md was committed at 0 bytes while the branch's own session-break summary claimed a graph dump had been recorded there. It had not been. See the preserved-knowledge doc §3 for the verified discrepancy.
3. Commits bundled provenance — prior uncommitted WIP and report.json landed under one message, muddying the record of what was reviewed.

None of this reached main — the branch was never merged (verified in §2). But the pattern it exhibits (one more bespoke regex, one more case) is the thing being halted, independent of this specific branch's debt. Per the ruling recorded here: no further bespoke-per-case regex work proceeds on this reader. The existing regex reader is not being torn out — it keeps serving as-is (§2) — but it is not being extended case-by-case going forward. The forward direction is proposed in §5, gated on a human ruling.

2. Decision — halt + clean-base reset (executed and verified)

All of the following were verified by direct command against the repository, not asserted:

• Local main == canonical tip. git rev-parse on refs/heads/main, origin/main (GitHub mirror), and forgejo/main (source of truth per this project's routing doctrine) all resolve to 854ce023d9cd58663ce9c9af0d62f92684ffb277 — the merge commit for PR #79 (increment-1 BAND plan: seed + comparison #78 + question-arithmetic). Local main had drifted to this tip via an earlier git reset: moving to forgejo/main (from a stale 920695bd); git merge-base --is-ancestor 920695bd 854ce023 confirms that reset was fast-forward-equivalent — 854ce023 is a strict descendant, no history was rewritten or lost.
• feat/reader-inc2-caseband / PR #80 is abandoned, not merged. merged: false, merge_commit_sha: null on the PR; the branch's tip (e3da148d) is not an ancestor of main. The PR is closed (not merged) with a comment referencing this ADR (see the PR thread). The branch ref itself is left intact on the remote as an archived reference — no force-delete, no history rewrite.
• Main is free of the branch's specific debt. grep -rn "_COMPARE_MASSNOUN_RE" and a grep for the loosened multi-word _token_in signature (source_span: str | None = None) both return zero matches under generate/. No empty *proof*.md exists anywhere in docs/ (0148-first-conversion-proof.md is the one populated fresh in this recalibration, §3 below — 4.6 KB, not empty).
• The legitimate foundations are intact and unmodified. compare_multiplicative (the #77 compiler tier) and NEUTRAL_COUNT_VERBS / the positive-polarity allowlist (#78) are both present across generate/math_candidate_parser.py, generate/math_roundtrip.py, generate/recognizer_match.py, and related modules — these are sound, reviewed, and load-bearing, and this recalibration does not touch them.
• Smoke and the holdout baseline are green on this exact state. uv run core test --suite smoke -q → 176 passed, 0 failed. uv run python -m evals.gsm8k_math.holdout_dev.v1.runner → correct=5 wrong=0 refused=495 (n=500) — matching the committed evals/gsm8k_math/holdout_dev/v1/ report.json baseline exactly (the pre-branch state, before 0148's one-case flip). wrong=0 holds.

No scope beyond the abandoned branch's own additions was removed. This recalibration is a reset to the already-correct main, not a rollback of anything reviewed and merged.

3. Preserved knowledge (not lost)

Two facts of genuine, general value were extracted from the abandoned branch before it was set aside, and are now captured — independently re-verified, not copied from the branch's own claims — in docs/research/reader-arc-recalibration-preserved-knowledge-2026-07-19.md:

1. The has_numeric_token multiplier-blindness bug (generate/math_candidate_parser.py:2374) — the closed word-number set the reader uses to decide whether a statement sentence carries parseable numeric state does not include multiplicative comparatives (twice, thrice, double, triple). This is real and reproducible (verified against 23 real cases in holdout_dev/v1 where it matters), but — also verified — it has not been a wrong=0 hazard, because the independent ADR-0191 completeness guard (generate/math_completeness.py) already resolves multipliers correctly via the en_numerics_v1 pack and refuses rather than confabulates. Net effect: missed conversions, not wrong answers. A minimal, general fix idea is documented (extend has_numeric_token to recognize the closed _ANCHOR_TO_FACTOR multiplier set) but is explicitly not landed — per this project's floor, a shared-primitive change lands only with full-500 wrong=0 proof and paired with whatever downstream op consumes it, never in isolation.
2. Case 0148 solves correct-for-the-right-reason. The real (non-empty) graph dump — docs/research/0148-first-conversion-proof.md — shows the conditional-seed binding the named reference (second day = 500), the compare op reading forward (first day = 2×second day, not an inverted guess), and the summation covering exactly both registers to reach 1500. This is a validation target for a future increment, not code being landed now.

4. Overfit inventory (a list, not a deletion)

A read-only survey of generate/*.py and evals/refusal_taxonomy/*.py on main identified bespoke, single-case-shaped surface patterns — regexes and extractors that encode one sentence's exact wording rather than a general grammatical class. The full, file:line-cited list lives in docs/research/reader-arc-overfit-inventory-2026-07-19.md. This is inventory, not a removal list — every pattern on it keeps serving unmodified; the reader must keep working until a proven replacement exists (§7 of the task guardrails). Its purpose is to give the geometric-normalization spike (§5), if ruled to proceed, a concrete target list of what "one general operator replacing N bespoke regexes" would need to subsume before it could claim a positive generalization ratio.

5. Proposed forward direction — geometric surface→canonical normalization spike (AWAITING RULING)

This section is a proposal. Nothing in it is authorized to be built by this ADR. It is recorded so the design-first gate has a concrete direction to rule on, per the task that produced this recalibration.

5.1 Thesis

Instead of hand-writing one new regex per newly-encountered surface shape, normalize a statement's surface text into a canonical geometric representation and let a single general operator align novel surface forms to already-known canonical forms — replacing N bespoke regex families with one normalization step plus a small, closed set of canonical forms the solver already understands.

5.2 Building blocks — already implemented, off-serving; to be wired, not invented

Verified present in the repo, all currently off-serving/telemetry-only for this purpose:

• conformal_procrustes (core/physics/dynamic_manifold.py:634) — Kabsch-conformal Procrustes / field conjugacy: finds the best versor (or grade-1 sandwich adjoint) mapping a source point-set onto a target point-set. Docstring is explicit: "Off-serving geometry; not wired into chat/runtime." This is the general primitive ADR-0239 (Proposed) already scopes for analogical transfer; this spike would be one concrete application of it, not a new mechanism.
• VocabManifold (vocab/manifold.py:68) — the geometric vocabulary: every word is a unit versor in Cl(4,1); nearest(F) finds the closest word by CGA inner product (no cosine similarity, no ANN index, per the module's own normalization doctrine).
• The cognition pipeline's "conformal anti-unifier" intent (core/cognition/pipeline.py:472-478, "Phase C — Geometric Anti-Unification") — currently read-only telemetry that captures graph-structural context around OOV/pending holes "so that a future exact-CGA sub-graph anti-unifier can operate on conformal neighbors rather than lexical token match." Explicitly observational only today ("never affects surface, hash (yet), or any durable mutation").

The spike, if ruled to proceed, would be the work of assembling these three already-accepted-or-proposed primitives into a reader-normalization path — not inventing new geometric machinery.

5.3 Proposed measurement — generalization ratio, wrong=0-gated

Define generalization ratio = (real holdout_dev/v1 cases newly converted refused→correct) ÷ (new concepts/parameters added to the normalizer to achieve that). Contrast baseline: the bespoke-regex era's own ratio is ~1 case per bespoke regex family (0148's mass-noun frame converted exactly one case for one new regex + one actor-binding relaxation + one Gate-A1 widening). The spike's burden of proof is a ratio durably greater than 1 — one normalization concept lifting more than one case — before it is allowed to replace any existing regex path. Every measurement runs on holdout_dev/v1 (open, 500 cases, no key needed) via uv run python -m evals.gsm8k_math.holdout_dev.v1.runner; the sealed 1,319-case test is never touched by this spike's iteration loop, per this project's train/dev/test discipline (ADR-0175 and the holdout_dev/v1 README's own doctrine). wrong=0 is non-negotiable at every measurement — any correct→wrong regression kills the spike's claim regardless of lift elsewhere.

5.4 Explicit disclaimers

• Smith-chart algebra is NOT proposed and stays disclaimed. ADR-0246 §6 already rules this out by name ("no Smith-chart algebra") alongside a list of other non-goals (no analytic cast reactance, no VSWR/atlas work). This spike does not revisit that ruling. Where an "impedance-matching" intuition might be reached for, the equivalent capability is conformal_procrustes (§5.2) — an already-accepted primitive — not a new Smith-chart library.
• No "Fibonacci dimensional cascade" is proposed. The only Accepted Fibonacci work in this repo (ADR-0242, deterministic evidence-gated operators for optimization/scheduling/multi-scale allocation) is unrelated to reader surface normalization, and nothing here proposes extending it into a new cascade mechanism for this purpose.
• This spike does not touch the sealed test, does not modify the existing regex reader, and does not start with this ADR. It requires a separate, explicit ruling before any code is written.

5.5 Scope boundary if ruled to proceed

Off-serving spike only, measured against holdout_dev/v1, wrong=0-gated at every step, with the existing regex reader continuing to serve unmodified for the duration. Promotion of any spike output to serving code would itself require its own review and ruling — this ADR does not pre-authorize that step even conditionally.

6. What's ready to build next

Nothing is authorized to start building yet. What exists, verified, at the close of this recalibration: a clean main at the canonical tip with the #77/#78/#79 foundations intact and unmodified; the abandoned branch's debt provably absent; two preserved, re-verified validation targets (the has_numeric_token bug and the 0148 decomposition) waiting for whichever future increment picks them up; a descriptive (non-deletion) overfit inventory scoping what a normalizer would need to subsume; and a proposed — not started — geometric surface→canonical normalization spike with its building blocks verified present, its measurement contract (wrong=0-gated generalization ratio on holdout_dev/v1) defined, and its non-goals (Smith-chart algebra, any Fibonacci "dimensional cascade") explicitly disclaimed. The next action is a human ruling on §5 — whether to authorize the spike, in what scope, and against what acceptance bar — not further implementation.