core/docs/handoff/ADR-0174-PHASE-3B-4-COMBINED-SCOPE.md

ADR-0174 Phase 3b + Phase 4 — Combined Scope

Status: Proposed Date: 2026-05-28 Author: Shay Parent ADR: ADR-0174 — Held-Hypothesis Comprehension Predecessor PRs: #416 (Phase 1), #420 (Phase 2), #423 (Phase 3a), #426 (initial-overwrite hazard fix) Type: Combined dispatch pack — Phase 3b is prerequisite for Phase 4 to have anything to operate on

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Why combined

Per the 2026-05-28 post-merge diagnostic, layer-by-layer extraction-narrowness fixes do not compound on train_sample/v1. Each gsm8k case has 3-5 narrowness layers refusing simultaneously; fixing any single layer admits zero cases because other layers still refuse.

The architectural breakthrough that CAN admit cases is the combination of:

1. Phase 3b — compound-clause held hypotheses, so a sentence with multiple anchors produces multiple Hypothesis entries in ProblemReadingState.open_hypotheses rather than refusing at _CLAUSE_SPLIT_TOKENS.
2. Phase 4 — in-loop contemplate, so when constraint elimination leaves |surviving| ≥ 2 hypotheses, the reader can deterministically consult vault/packs/audit-history to pick the correct interpretation rather than refusing on ambiguity.

Phase 3b without Phase 4 only converts compound-clause sentences from "refuse-at-extraction" to "refuse-at-ambiguous-survival" — no admission lift. Phase 4 without Phase 3b has no |surviving| ≥ 2 cases to operate on (today's pipeline produces at most 1 survivor per sentence).

Combined, the two phases:

• Admit compound-clause sentences when constraint elimination leaves a unique survivor
• Resolve multi-actor pronoun ambiguity (the defense from PR #423) by consulting gendered-name packs
• Provide the substrate for Phase 5 (legacy parser removal) and any future ADR-0174 evolution

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Honest lift expectations

Phase	Substrate value	Realistic train_sample lift
3b alone	Compound-clause held hypotheses	0 (multi-actor defense refuses, solver gaps prevent admission)
3b + 4	+ in-loop contemplate over name packs	2-4 cases (cases that admit via single-survivor + gendered-pronoun resolution)
3b + 4 + Phase 5 (solver multi-qty)	+ same-actor multi-qty aggregation	6-8 cases (adds Malcolm/Daniel-style "total of N units" problems)

Phase 3b + 4 combined target: +2 to +4 train_sample cases when paired with the existing solver. The architectural payoff is the substrate, not the score; the score moves come when the solver work in issue-3 from the post-merge diagnostic lands alongside.

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Architecture overview

PARSE
  ├─ sentence has clause_split tokens?
  │    └─ NEW: _try_extract_compound_discrete_count_anchors() → tuple of anchors
  │        (one per clause, shared subject+verb from head clause)
  └─ injector emits one candidate per anchor (Phase 3b)

EMIT
  └─ each candidate → Hypothesis with rank = enumeration order
       (already implemented via hypothesis_from_initial / _from_operation)

ELIMINATE
  └─ eliminate_violating() runs per-hypothesis constraint check
       (Phase 2 — unchanged; Phase 3b just produces more hypotheses for it to act on)

HOLD
  └─ NEW Phase 4: when survivors ≥ 2 (which Phase 3b makes possible),
       invoke contemplate() before declaring ambiguity

CONTEMPLATE (Phase 4 — read-only deterministic search)
  ├─ vault recall (exact CGA) — prior session resolutions
  ├─ pack consult (gendered names, semantic classes, lexicon entries)
  ├─ audit history (prior reader refusals on same token)
  └─ returns Resolution | None — never a guess

ADMIT
  └─ if survivors → 1 after contemplate, admit
  └─ if survivors → 0 (all eliminated), refuse cleanly
  └─ if survivors ≥ 2 after contemplate, refuse with ambiguous_unresolvable trace

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Phase 3b — Compound-clause held hypotheses

Files touched

• generate/recognizer_match.py
  • New function: _try_extract_compound_discrete_count_anchors(statement, padded_lower, spec) -> tuple[Mapping, ...] | None
  • The compound-aware extractor: splits on conjunctive separators (and, , followed by digit), requires each clause to match the discrete-count regex shape with shared subject+verb from the head clause
  • Refusal-preferring: if any clause doesn't match the per-clause regex, return None (refuse the whole sentence)
  • Returns a tuple of anchors, all carrying the SAME subject_role / verb_token / anchor_kind from the head clause
• generate/recognizer_anchor_inject.py
  • inject_discrete_count_statement already iterates match.parsed_anchors and builds one candidate per anchor — NO CHANGE needed. Phase 3b lights this up by populating parsed_anchors with N entries instead of 1.
• generate/math_candidate_graph.py
  • The Phase 2 hypothesis-emission wiring already handles len(injected) > 1 correctly — it builds one Hypothesis per injection, runs eliminate_violating, requires len(admitted) == len(injected) for the per_sentence_choices append.
  • No wiring change required for Phase 3b — the upstream (extractor producing N anchors) is the only new work.
• generate/comprehension/state.py
  • HYPOTHESIS_CAP raise. Today HYPOTHESIS_CAP = 4. Case 0040 has 5 anchors ("2 horses, 5 dogs, 7 cats, 3 turtles, and 1 goat"). Raise to 8 or refuse on cap-exceed with a documented marker. Recommendation: raise to 8 with a comment citing case 0040 as the empirical justification.

Constraints

• Refusal-preferring discipline: if ANY clause's extraction fails, refuse the whole sentence. Admitting partial state from a recognized-but-incomplete compound is the wrong=0 hazard (same shape as ADR-0167 case-0050 lesson).
• Shared subject + verb: every emitted anchor MUST share the same subject_role, verb_token, and anchor_kind. Compound sentences with mixed verbs/subjects (He bench presses 15 pounds and does 3 sets) refuse at the compound extractor.
• Whitelisted verb only: the head clause's verb must be in _POSSESSION_VERBS or _ACQUISITION_VERBS. Compound extension does NOT widen the verb set (that's separate VE work).
• Pronoun-subject head: when the head clause's subject is a pronoun, the same requires_pronoun_resolution marker fires on ALL anchors. The Phase 3a wiring (and its multi-actor defense) operates correctly on multi-anchor compounds.

Tests

• New tests/test_adr_0174_phase3b_compound_clause.py:
  • Pure conjunctive list with proper-noun subject: admits (Malcolm/followers)
  • 5-anchor list with pronoun subject + single-actor antecedent: admits via Phase 3a wiring (Daniel/animals)
  • 5-anchor list with pronoun subject + multi-actor antecedent: refuses via multi-actor defense
  • Mixed-verb compound: refuses at compound extractor (preserves wrong=0)
  • Multiplicative-tail compound (...and three times as long): refuses at compound extractor
  • Cap enforcement: 9-anchor compound refuses
  • All-or-nothing: if clause 3 of 5 fails to ground, all 5 dropped (no per_sentence_choices append)

Acceptance gate

• 0 lift on train_sample admitted as expected
• wrong=0 invariant preserved
• Case 0050 hazard test passes
• Multi-actor pronoun defense still fires on compound + pronoun cases
• Smoke 67/67, packs 141/141

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Phase 4 — In-loop contemplate

Files touched

• generate/comprehension/contemplate.py (NEW module — ~300 lines):
  • Resolution dataclass — kind ∈ {"eliminate", "admit_unknown"}, target_hypothesis_id, sub_question, source ∈ {"vault", "pack", "audit_history"}, evidence tuple.
  • contemplate(state: ProblemReadingState, residual: tuple[Hypothesis, ...]) -> Resolution | None
  • Three deterministic adapters, consulted in order:
    1. _consult_vault(...) — exact CGA recall over VaultStore for prior session evidence
    2. _consult_packs(...) — closed-set lookup over loaded packs (initial Phase 4 use case: gendered name pack for pronoun resolution)
    3. _consult_audit_history(...) — read-only over reader-refusal log
  • Returns None on any ambiguous result (evidence supports multiple hypotheses equally) — refusal-preferring.
• generate/math_candidate_graph.py:
  • When eliminate_violating returns len(survivors) >= 2, invoke contemplate before treating as ambiguous-refusal.
  • On successful resolution: apply the Resolution (eliminate the indicated hypothesis OR admit a previously-held unknown) and continue admission with the unique survivor.
  • Trace events: {"layer": "contemplate", "phase": 4, "outcome": "resolved" | "ambiguous_unresolvable", "source": "...", "evidence": [...]}
• generate/comprehension/state.py:
  • No change. The substrate (open_hypotheses, UnknownHeld) is already in place.

First concrete Phase 4 use case: gendered pronoun resolution

The multi-actor pronoun hazard defense (PR #423) currently refuses on ambiguity. Phase 4 turns the defense into an admission opportunity:

Today (multi-actor refusal):

"Alice has 5 marbles. Bob has 3 marbles. She buys 2 marbles."
  → no_antecedent_ambiguous (refuse, candidate_antecedents=[Alice, Bob])

With Phase 4 + gendered names pack:

"Alice has 5 marbles. Bob has 3 marbles. She buys 2 marbles."
  → contemplate("She", residual=[Alice→hypothesis_0, Bob→hypothesis_1])
  → _consult_packs: gendered_names["Alice"] = "female", gendered_names["Bob"] = "male", "She" requires female
  → Resolution(kind="eliminate", target_hypothesis_id=1, source="pack",
               sub_question="which antecedent is female-gendered?")
  → admit hypothesis_0 (Alice + buy 2)

The pack consulted is a new closed-set artifact: language_packs/data/en_core_names_v1/gender.jsonl (or similar). Building this pack is part of Phase 4 scope — small (~200 entries covering common English first names), reviewed through the standard HITL corridor (ADR-0150/0152), refusal-preferring on unknown names.

Constraints

• No LLM, no sampling, no normalization. contemplate is deterministic search over already-ratified evidence. Ambiguous results return None and the reader refuses cleanly.
• Read-only over evidence sources. No vault writes, no pack mutations, no audit-history modification. Any new evidence proposed by contemplation rides the existing offline HITL corridor.
• Trust boundary. Vault recall uses exact CGA (no approximation). Pack consults are closed-set membership checks. Audit history is read-only over an append-only log. No new code execution surfaces.
• HYPOTHESIS_CAP unchanged. If 5 hypotheses survive and contemplate eliminates 3, leaving 2 ambiguous, the reader still refuses (no second contemplate pass within the same sentence — bounded by structural assertion).

Tests

• New tests/test_adr_0174_phase4_contemplate.py:
  • Empty residual: contemplate returns None (no-op)
  • Single survivor: contemplate returns None (caller doesn't need to disambiguate)
  • Gendered pronoun + gendered name pack: resolves correctly, returns Resolution
  • Gendered pronoun + unknown name: returns None (refuse cleanly)
  • Multi-actor + same-gender antecedents: returns None (no disambiguation possible)
  • Vault has prior resolution: returns Resolution sourced from vault
  • Determinism: same input → same Resolution byte-identical
  • Trace event shape validated

Acceptance gate

• ≥ 2 train_sample case lift (the multi-actor cases that resolve via gender pack)
• wrong=0 invariant preserved
• Case 0050 hazard test passes
• New en_core_names_v1 pack passes the pack-test discipline (CLAUDE.md §Semantic Pack Discipline)
• Smoke + packs + lanes green

Open questions (resolve before Phase 4 PR)

1. Gendered names pack scope. Initial proposal: ~200 common English first names from Census Bureau / SSA public data, manually reviewed for unambiguous gender. Edge cases (Jordan, Alex, Casey, etc.) are NOT in the pack — they return None from _consult_packs and the reader refuses, preserving wrong=0.
2. Contemplate evidence precedence. ADR-0174 §Open Q#3 proposed vault > packs > audit_history. Confirm against actual evidence formats before Phase 4 wires the adapters.
3. Pronoun-pack source. Whether she/he/they/it → gender mappings live in en_core_names_v1 or a separate en_core_pronouns_v1 pack. Recommendation: separate pack, because pronouns are syntactic and names are semantic — different review pathways.

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Sequencing

Phase 3b PR
  ├─ extractor + cap raise + tests (parallel-safe)
  └─ no math_candidate_graph wiring change needed

Phase 4 PR (stacks on Phase 3b)
  ├─ contemplate.py + tests (parallel-safe)
  ├─ en_core_names_v1 pack creation + tests (parallel-safe)
  ├─ math_candidate_graph wiring at the |survivors|≥2 site
  └─ acceptance verified across all suites

Both PRs are operator-dispatchable; recommend Opus for both (wrong=0 hazard surfaces on the extractor and the resolution-vs-refusal decision).

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Truth tests

Before any merge:

1. wrong=0 invariant. train_sample/v1 report wrong=0.
2. Case 0050 canary. Explicit test passes (memory feedback-wrong-zero-hazard-case-0050).
3. Multi-actor defense preserved. When contemplate can't disambiguate, the existing no_antecedent_ambiguous refusal fires (memory project-adr-0174-multi-actor-pronoun-hazard).
4. Determinism. Two runs of parse_and_solve on the same input produce byte-identical reader_trace including contemplate events.
5. Lift evidence. At least 1 train_sample case lifts from refused→correct via the combined 3b+4 wiring with a lookback and contemplate trace event both visible.

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What this combined scope DELIBERATELY excludes

• Solver multi-quantity aggregation. Daniel has 2 horses. Daniel has 5 dogs. How many animals? would need a superordinate-noun pack and solver support — separate ADR scope.
• Verb expansion. VE-A/B/C brief covers this. Phase 3b refuses on compound sentences with non-whitelisted verbs; Phase 4 doesn't widen the verb set.
• Same-actor same-unit cumulative semantics. Resolved by the PR #426 hazard fix (refuse, not silent overwrite). Cumulative addition requires explicit operation verbs ("buys", "receives") which already work.
• Question-side pronoun resolution. Phase 4's contemplate is statement-scoped in this scope. Question-side pronoun resolution is Phase 4.1 follow-up.
• Per-token apply_word integration. Phase 5 work — retire legacy parser, move admission into the reader.

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Cross-references

• Parent ADR: docs/decisions/ADR-0174-held-hypothesis-comprehension.md (Proposed; Phase 1-3a + amendment shipped)
• Predecessor PRs: #416, #420, #423, #426
• Lookback review doctrine: CLAUDE.md §Lookback Review Discipline
• Hazards memory: project-adr-0174-multi-actor-pronoun-hazard, feedback-wrong-zero-hazard-case-0050
• Thesis anchor: [[thesis-decoding-not-generating]] — every contemplate resolution must find evidence that already exists; the engine decodes, it does not invent
• HITL corridor: ADR-0150/0152/0155/0161 — Phase 4's pack additions ride this corridor unchanged