Grounded in a ground-truth measurement of the 47 train_sample refusals
against GSM8K's own <<a*b=c>> calculator annotations:
- 37/47 (79%) use multiplication; 43/47 use mul-or-div; 0/47 single-step
- multiplication is the foundational general capability (breadth = the
anti-overfitting signal), but necessary-not-sufficient: no case flips
from an operation matcher alone
Solver already supports {add,subtract,transfer,multiply,divide,apply_rate,
compare_additive,compare_multiplicative}; the gap is the reader->injector->
Operation front-end (matcher extracts 0 anchors on real sentences).
Sub-phase sequence (biggest-chunk-first, measure-the-flip-gated):
- 5b.1 single-sentence multiplicative aggregate (cleanest proof, ~2-4)
- 5b.2 shallow 2-3 step composition (25/47, the real chunk)
- 5b.3 deep multi-step 4-7 (22/47) under held-hypothesis elimination
Generality guard: flipped cases must hold under ADR-0114a perturbation/OOD.
Explicitly NOT widening discrete_count injector (overfitting + wrong=0 hazard).
The recognizer/candidate-graph path is the single canonical reader.
Retires the flag-gated incremental-reader dispatch that admitted 0/50 on
train_sample and only added a dead fall-through:
- remove _try_comprehension_reader, _try_reader_for_question, _tokenize_sentence
and both dispatch blocks from generate/math_candidate_graph.py
- delete generate/comprehension/lifecycle_runtime_adapter.py (402 LOC,
used only by the question-reader dispatch)
- drop the comprehension_reader_questions config flag and the parse_and_solve
/ _score_one_candidate_graph config threading
- remove the --use-reader runner plumbing + flag-ON/OFF delta report from
the train_sample runner; refresh report.json (drops stale use_reader field
and a stale refusal-reason; verdicts unchanged at 3/47/0)
- remove the now-dead use_reader field from teaching/coverage.py
CoverageReport + the core teaching coverage CLI flag
- delete tests/test_reader_coexistence.py (flag-ON/OFF premise dissolved);
fix 3 ADR-0174 build_report calls and 2 subprocess invocations
lifecycle.py and audit.py are KEPT — they are load-bearing for the ADR-0172
math-contemplation teaching corridor (audit_problem -> teaching/math_*),
which a pre-deletion trace surfaced. The parent ADR's plan to delete
lifecycle.py was wrong; only its GSM8K scoring dispatch was inert.
Net -1,038 LOC (code + tests). Behavior-preserving:
- train_sample 3/47/0, byte-identical verdicts to pre-5a baseline
- determinism holds; smoke/packs/runtime/cognition/teaching lanes green
- contemplation corridor + lifecycle/audit tests pass
Pre-existing (NOT introduced here; reproduce on base with changes stashed):
5 out-of-curated-lane stale committed-artifact / stale-assertion failures
(test_math_evidence_e2e, test_adr_0126_runner_wiring, G3/coverage_probe
report-match, test_refusal_taxonomy_lane rebuild).
Pre-implementation investigation (lookback discipline) found the original
Phase 5 text inverted against shipped code:
- math_parser.py already out of runtime + candidate-graph scoring path
- lifecycle.py admits 0/50 (inert parallel parser, not the reader to promote)
- correct>=25 is a semantic gate structural collapse cannot meet
Decision (Invert + split): recognizer/candidate-graph path is the canonical
reader; lifecycle.py is retired. Phase 5a = structural retirement (net -LOC,
3/47/0 byte-identical, wrong=0). Phase 5b = semantic narrowness removal (the
real lift, own sub-phases, per-layer wrong=0 obligations).
All findings from the 2026-05-28 Phase 1-3a lookback review addressed
in one commit on the Phase 3a branch:
Wrong=0 hazard defense (the load-bearing fix):
- generate/math_candidate_graph.py: Phase 3a wiring now collects the
set of distinct proper-noun subjects seen in prior context. When
more than one exists, refuses with no_antecedent_ambiguous trace
event rather than guessing the most-recent (which was gender-blind
single-binding — wrong attribution in multi-actor problems).
- Refusals from the statement loop now preserve _statement_trace via
reader_trace in CandidateGraphResult (pre-existing latent issue:
Phase 2/3 trace events were dropped on early statement refusal).
- New tests assert: ambiguous case refuses with correct trace; single-
actor case still resolves normally.
Test coverage backfills (closes the 13 untested predicate-name gaps):
- TestCheckConstraintsInitialPredicateNames — 3 tests asserting the
exact predicate name on initial.value_grounds / initial.unit_grounds
/ initial.entity_grounds failure paths.
- TestCheckConstraintsOperationPredicateNames — 3 tests asserting
operation.verb_grounds / operation.value_grounds / operation.unit_grounds
failure-predicate-name parity.
- TestCheckConstraintsComposedInitialPath — 4 tests for the RAT-1
composed_initial path which was entirely untested in Phase 2
(parity manually verified during lookback review; now automated).
ADR amendment (honest doc vs impl drift):
- docs/decisions/ADR-0174-held-hypothesis-comprehension.md: appended
'Implementation Notes' section documenting:
- reevaluate signature differs from spec text (shipped is more
composable; treat as amended)
- Phase 2 wires per-candidate, not per-token (per-token is Phase 5)
- Lookback recompute is candidate-level, not token-level
- Hypothesis.constraint_state is never populated by Phase 2
- Multi-actor pronoun hazard defense rationale
- Honest LOC accounting: Phases 1-3a net +1,500 lines (Phase 5
delivers the projected net removal)
- Test coverage backfill summary
Cosmetic:
- lookback.py:297 unreachable raise — added # type: ignore[unreachable]
with comment explaining defensive future-proofing for Phase 3b.
Acceptance verified:
- 124/124 Phase 1+2+3a + reader tests pass (was 95/95 before backfills)
- Smoke 67/67, packs 141/141
- train_sample 3/47/0 preserved (wrong=0 invariant held)
- Multi-actor hazard live-tested: parse_and_solve refuses the
Alice/Bob/She case with no_antecedent_ambiguous trace event
See CLAUDE.md §Lookback Review Discipline and memory
feedback-lookback-review-discipline for the doctrine that surfaced
all of these issues at the right time.
Extends ADR-0164's incremental comprehension reader from single-committed
state to held-hypothesis state, adding lookback re-evaluation and in-loop
contemplation. Diagnoses why the ADR-0164 reader is wired but inert
(all-or-nothing refusal at first unknown token / unexpected category).
Architecture: apply_word produces ProblemReadingState.open_hypotheses
(small ranked set, HYPOTHESIS_CAP=4 initial). Three operators per token:
EMIT (extend compatible hypotheses), ELIMINATE (constraint violations
remove hypotheses immediately), HOLD (uncommitted hypotheses survive at
lower confidence). At finalize(), |survivors|=0 refuses, |survivors|=1
admits, |survivors|>=2 invokes in-loop contemplate() over vault + packs
+ audit history. Ambiguity contemplation cannot resolve refuses cleanly,
preserving wrong=0.
Collapses three parallel parsing systems into one held-hypothesis
reader: removes regex parser runtime path (math_parser.py),
per-category injector dispatch table (recognizer_anchor_inject._INJECTORS),
and duplicate per-sentence-choices scaffolding. Net ~1,900 lines
removed; reader grows by ~600 for hypothesis state + reevaluate +
contemplate.
Preserves ADR-0164 lexicon and category set, ADR-0165 regex scope,
ADR-0150/0152/0155/0161 HITL corridor, binding graph + solver
substrate, capability-axis lanes, replay-equivalence gate. Trust
boundary for in-loop contemplation: read-only over vault/packs/audit;
ratification still rides offline HITL.
Status: Proposed. Six phases (no timelines) gated on wrong=0 and
capability-axis 100% at each transition. Five open questions resolved
before Phase 1 PR.
