First PR plumbing recognizer parsed_anchors into the candidate-graph as
typed CandidateInitial primitives. Scope limited to discrete_count_statement;
other five round-2 categories route to the round-2 skip-only fallback until
follow-up D.2.x PRs.
Five-layer wrong=0 safety net:
1. Matcher narrowness — _try_extract_discrete_count_anchor refuses on any
ambiguity (multi-subject, pronoun subject, non-possession verb,
multi-count, clause-split, unobserved counted_noun, unobserved
count_kind).
2. Extraction correctness — refusal-preferring; populated parsed_anchors
only when ALL narrowness rules hold.
3. Injection correctness — _initial_admissible gates every constructed
CandidateInitial; failure to ground returns () (under-admit).
4. Replay gate — propose-time admissibility_replay_gate auto-rejects any
matcher change that would lift GSM8K wrong count.
5. Multi-branch decision rule — injected candidate disagreeing with
another branch triggers refuse path.
Re-baseline (GSM8K train_sample v1):
- Old (#309 alone): correct=3 refused=47 wrong=0
- New (#309 + D.2 v1): correct=3 refused=47 wrong=0
- Empirical lift in v1 = 0 cases; framework operational. No GSM8K
train_sample case has a discrete_count statement that simultaneously
meets all narrowness rules AND is missed by the existing parser.
Bottleneck moves to other recognizer categories (D.2.2+).
Validation:
- tests/test_adr_0163_d2_discrete_count_injection.py: 34 passed
- tests/test_recognizer_match.py + test_candidate_graph_recognizer_wiring
+ test_admissibility_replay_gate: 27 passed
- adr_0131_* (G1..G5 + S1 wrong=0 invariant): 222 passed / 2 pre-existing
report-comparison failures / 3 skipped — byte-identical to pre-D.2
- Solver code: unchanged
Operator caveat: round-1's ratified discrete_count_statement spec is
unchanged. Matcher behavior on the spec's canonical_pattern has been
extended from detection-only to populated parsed_anchors. Re-ratification
is not required; if policy requires it on matcher-behavior changes, the
registry digest provides byte-stable provenance.
