# ADR-0164.2 — Pronoun / Entity Resolution Policy

**Status:** Proposed
**Date:** 2026-05-26
**Author:** Shay
**Anchor:** [[thesis-decoding-not-generating]]
**Parent:** [ADR-0164 — Incremental Comprehension Reader](./ADR-0164-incremental-comprehension-reader.md)
**Companion:** [ADR-0164.3 — ProblemReadingState and cross-sentence registry](./)
**Resolves:** ADR-0164 §Open question #3 ("Pronoun-entity resolution")

---

## Context

ADR-0164 replaces the regex sentence-template front-end with an incremental
compositional reader. Open question #3 of that ADR notes that the reader needs
entity resolution and that the regex parser's
`_resolve_question_entity` heuristic (`generate/math_candidate_parser.py:2457`)
is "a reasonable starting point but should be reviewed against the
compositional model." This ADR carries out that review and specifies the
replacement policy.

Pronoun and entity resolution is load-bearing for GSM8K. A large fraction of
question sentences refer to the subject of preceding statements only by
pronoun ("how much money does **she** make?", "how much will it cost **him**?",
"how much weight does **he** have to lose?"). A reader that comprehends the
whole problem but refuses on the question because it cannot resolve the
question's subject pronoun is a reader that has failed at exactly the moment
it needed to commit.

The replacement must hold to the same invariants ADR-0164 holds to:
deterministic, no hidden normalization, no stochastic fallback, refuses
cleanly on novel structure, and produces evidence the teaching loop can
chew on (typed refusal reasons with position information).

## §1 — Review of the existing heuristic

The function under review is `_resolve_pronoun_entity` (lines 2413–2454) and
its wrapper `_resolve_question_entity` (lines 2457–2477). Its behavior:

1. The pronoun surface form is lower-cased.
2. `they` and `it` are unconditionally refused.
3. `she` / `her` look up the `_FEMALE_NAMES` whitelist (62 entries, line
   2376).
4. `he` / `his` / `him` look up the `_MALE_NAMES` whitelist (76 entries, line
   2389).
5. The full problem text is scanned with a Title-cased proper-noun extractor
   (`_PROPER_NOUN_MENTION_RE`, line 2408).
6. Distinct names matching the gender whitelist are accumulated in order of
   first mention.
7. **Exactly one** match → resolve to that name. Zero or two-plus → refuse.

### §1.1 What this heuristic gets right

- **Refuse-on-ambiguity is the correct default under wrong = 0.** Returning
  the wrong entity binding produces a candidate that the binding graph will
  happily admit and the verifier may not catch (the verifier checks unit
  closure and arithmetic, not whether the question subject was the right
  person). Refusal flows to the teaching loop instead.
- **Pure and deterministic.** No global state, no normalization side effects,
  no nondeterministic name picking.
- **Closed-set vocabulary.** The name whitelists are ratified data; they are
  the seed for the operational lexicon ADR-0164 promotes them into.
- **Plural and neuter refusal.** `they` and `it` are not pretended-resolved.

### §1.2 What it gets wrong

Five concrete failure modes are observable on the GSM8K train_sample:

**F1 — Whitelist closed-set gap.** The proper-noun extractor finds names that
are not on either whitelist (Yun, Marion, Rex, Georgie, Allison in
train_sample). When the question uses a pronoun whose only entity candidate
is one of these, the heuristic refuses despite the antecedent being
unambiguous in context.

- *Example.* Case 0034 ("Georgie is a varsity player on a football team.
  **He** can run 40 yards within 5 seconds. … how many yards will **he** be
  able to run within 10 seconds?"). `Georgie` is not in `_MALE_NAMES`.
  Distinct-males-matching = 0. Refuses with no candidate. The text is
  unambiguous: Georgie is the only animate proper noun in the problem.

**F2 — Multi-entity question text where recency disambiguates.** The
heuristic counts *distinct* mentions over the whole problem and refuses on
≥2. Recency, syntactic role, and the question's own subject slot are
discarded.

- *Example.* Case 0017 ("Jason has a carriage house … Eric wants to rent the
  house for 20 days. How much will it cost **him**?"). Two males (Jason,
  Eric). Distinct count = 2 → refuses. But "Eric wants to rent" is the only
  agent-of-renting clause; "cost him" attaches to the renter. A recency- or
  role-aware policy resolves this. The current heuristic cannot.

**F3 — Plural antecedent of a group introduced by conjunction.** `they` is
unconditionally refused. When a problem opens with a conjoined subject
("Aaron and his brother Carson each saved up $40 … how many scoops did
**they** each buy?"), the group is well-defined and the question is
well-posed. Refusing collapses a solvable case.

- *Example.* Case 0026. Distinct males = 2 (Aaron, Carson). On a per-name
  question this is ambiguous; on `they` it is exactly the group. The
  heuristic refuses both ways.

**F4 — Kinship and relational entities are invisible.** "her grandfather",
"her father", "her mother", "his brother", "his friend" introduce entities
that participate in arithmetic but never enter the registry. The Title-cased
extractor sees only proper nouns.

- *Example.* Case 0033 ("Rachel is 12 years old, and **her grandfather** is
  7 times her age. **Her mother** is half grandfather's age, and **her
  father** is 5 years older than her mother. How old will Rachel's father be
  when **she** is 25 years old?"). The statement-layer "her" inside "her
  grandfather" has no referent to bind to *as a self-standing entity*; it is
  a relational modifier. The question-layer "she" has Rachel as the unique
  female proper noun — both policies resolve here — but the underlying
  reading is wrong: the heuristic treats "her grandfather" as a
  document-internal mention rather than as a relational entity rooted at
  Rachel.

**F5 — Inferred-gender names are not learned in context.** If the same
unknown name appears with `he` ten times across a problem, the heuristic
still cannot resolve any of them, because gender is only inferred from the
whitelist. There is no co-reference feedback.

- *Example.* Case 0034 again — every "he" in the text is structurally
  unambiguous given the single proper noun. The heuristic learns nothing
  from this.

### §1.3 Summary verdict

The heuristic is correct in policy (refuse on ambiguity, deterministic,
whitelist-based, closed-set) and inadequate in representation. Its evidence
about pronouns lives in a flat scan of the entire problem text; the
compositional reader has, by Phase 1, an ordered stream of comprehended
entities with positions. The heuristic should be replaced by a policy that
consumes that stream — same conservatism, more information.

## §2 — Replacement: EntityRegistry as a field on ProblemReadingState

The reader maintains a `ProblemReadingState` across sentences (ADR-0164.3
specifies this carrier in full). One field of that state is an
`EntityRegistry`:

```text
EntityRegistry:
  entries: tuple[EntityEntry, ...]   # frozen tuple, append-only per sentence
  resolution_log: tuple[Resolution, ...]   # per-pronoun decision evidence

EntityEntry:
  canonical_name:        str            # the surface lemma as comprehended
  gender_inferred:       Gender         # FEMALE | MALE | NEUTER | GROUP | UNKNOWN
  gender_source:         GenderSource   # LEXICON_NAME | KINSHIP | PRONOUN_BACKFILL | DECLARED
  first_mention_pos:     SourcePosition # (sentence_idx, token_idx)
  last_mention_pos:      SourcePosition # updated on each subsequent mention
  relational_anchor:     EntityRef | None  # for kinship/relation entities ("her grandfather" → anchor=Rachel)
  syntactic_roles:       tuple[Role, ...]  # SUBJECT, OBJECT, POSSESSOR, …

Resolution:
  pronoun_surface:       str            # "she", "him", …
  pronoun_pos:           SourcePosition
  decision:              ResolvedEntity | RefusalReason
```

The registry is part of the reader's immutable state per ADR-0164 §Decision.
Every entity entrance and every pronoun resolution appears in the log; the
log is part of the canonical-bytes serialization that drives `trace_hash`.

### §2.1 How entities enter the registry

The reader's lexicon (ADR-0164 §Decision §Operational lexicon) already
distinguishes `proper_noun_entity`, `entity_pronoun`, and the kinship /
relational category set. Entry into the registry happens at three points:

1. **Proper-noun entity.** When a token's category is `proper_noun_entity`,
   a fresh entry is appended. Gender is inferred from
   `lexicon[token].gender_marker` if present; otherwise `UNKNOWN`. Source =
   `LEXICON_NAME`.

2. **Kinship / relation noun with possessor.** When a possessive determiner
   ("her", "his", "their", "Rachel's") attaches to a kinship noun in the
   lexicon's `kinship_relation` category, a fresh entry is appended with
   `relational_anchor` = the resolved possessor and `gender_inferred` =
   `lexicon[kinship_noun].gender_marker` (mother → FEMALE, father → MALE,
   sibling → UNKNOWN, friend → UNKNOWN, etc.). Source = `KINSHIP`.

3. **Conjoined subject.** When the reader closes a noun-phrase frame opened
   by `<entity> and <entity>`, a `GROUP` entry is appended whose membership
   tuple holds the two component entries. The component entries remain
   separately registered; the group entry is what `they` resolves against.
   Source = `LEXICON_NAME` (for the conjunction frame closure).

The registry is **append-only per sentence**. Re-mentions update
`last_mention_pos` and may add a syntactic role, but do not create a new
entry.

### §2.2 How pronouns resolve

When the reader's category for the current token is `entity_pronoun`, the
policy is:

1. Compute `compat_gender`: FEMALE for `she/her/hers/herself`; MALE for
   `he/him/his/himself`; GROUP for `they/them/their/themselves`; NEUTER for
   `it/its/itself`.
2. Filter registry entries: keep entries `E` where
   `compatible(E.gender_inferred, compat_gender)`. The compatibility table
   is:
   - FEMALE ↔ FEMALE
   - MALE ↔ MALE
   - GROUP ↔ GROUP
   - GROUP ↔ {FEMALE, MALE} only if the group's components include at least
     one member of the requested gender (used for "she" picking out the
     female member of a mixed group; not currently used at Phase 1).
   - NEUTER ↔ NEUTER (excludes animates; used for cost/object/process
     antecedents)
   - UNKNOWN ↔ {FEMALE, MALE}: tentatively compatible, see step 5.
3. If the filtered list is empty: **refuse** with reason
   `unresolved_pronoun`. Position evidence = pronoun_pos and the registry
   snapshot.
4. If the filtered list has more than one **certain-gender** entry: apply
   the recency tiebreaker (§2.3). If the tiebreaker leaves two entries
   within the ambiguity window: **refuse** with reason
   `ambiguous_pronoun_referent`.
5. If the only candidate is `UNKNOWN`-gendered and exactly one such entity
   exists in the entire registry (the "single salient entity" case): bind
   the pronoun to it AND back-fill the entity's `gender_inferred` =
   `compat_gender`, `gender_source = PRONOUN_BACKFILL`. This addresses F1
   and F5 without weakening conservatism: the back-fill triggers only when
   the entity is *uniquely available*.
6. Otherwise (multiple UNKNOWN entries, no certain-gender candidate): refuse
   with `ambiguous_pronoun_referent`.

Every branch appends a `Resolution` to the log with full position and
candidate set so the teaching loop sees exactly why a binding succeeded or
refused.

### §2.3 Recency tiebreaker

When ≥2 certain-gender entries match:

- Compute `last_mention_distance(E) = pronoun_pos − E.last_mention_pos` in
  token units (across sentences, sentence boundaries count as a fixed token
  penalty `SENTENCE_PENALTY = 1` to make cross-sentence reach explicit and
  bounded).
- The candidate with the **smallest** distance wins, **provided** the next
  candidate is at least `RECENCY_GAP_MIN = 2` further. Otherwise the two
  candidates are within the ambiguity window and the policy refuses.
- Subject-role mentions count once; object/possessor mentions are not
  preferred or demoted (no syntactic bias at Phase 1 — adding one is a
  separate sub-ADR with measurement).

The constants `SENTENCE_PENALTY` and `RECENCY_GAP_MIN` are part of the
ratified policy. Changing either requires a sub-ADR and re-running the
capability lanes.

## §3 — Refusal-first ambiguity rules

Two rules are exhaustive at Phase 1:

### Rule R1 — `ambiguous_pronoun_referent`

**Trigger.** ≥2 certain-gender registry entries are compatible with the
pronoun and the recency tiebreaker does not separate them by at least
`RECENCY_GAP_MIN` tokens.

**Concrete example.** Hypothetical mini-text (from real GSM8K phrasing):

> "John gave Tom $5. **He** had $20 left."

Registry after sentence 1: `[John:MALE@(0,0), Tom:MALE@(0,2)]`. The
question-level pronoun "He" has `last_mention_distance(John) = 4`,
`last_mention_distance(Tom) = 2` (assuming a 4-token sentence). Tom is
nearer by 2. With `RECENCY_GAP_MIN = 2`, the gap is exactly the threshold;
the *strict* form (`gap > MIN`) refuses. The *permissive* form (`gap >= MIN`)
resolves to Tom. ADR-0164.2 adopts the **strict** form: refuse, surface
both candidates, let the teaching loop or a future role-aware sub-ADR
disambiguate. This preserves wrong = 0 in exchange for one refused case.

### Rule R2 — `unresolved_pronoun`

**Trigger.** No registry entry is compatible with the pronoun.

Two sub-cases:

- **R2a — no entity of the right gender.** E.g. `she` with only male
  entries. Refuses immediately.
- **R2b — empty registry.** E.g. a question that opens with a pronoun
  whose antecedent is in a prior sentence the reader has not yet
  comprehended (reader-order bug, or genuinely orphaned pronoun). Refuses
  immediately.

R2 refusals carry the registry snapshot in the log so the teaching loop can
see whether the gap was a missing entity, a missing kinship inference, or a
missing gender lexicon entry.

### What is **not** a separate rule

- "Plural pronoun with no group entity" → R2 (`they` with only singletons
  and no conjunction-closed group).
- "Neuter pronoun with only animate entries" → R2.
- "Possessive pronoun in a kinship phrase" (e.g. "her grandfather") is not
  a resolution event; it is an entity-creation event (§2.1 case 2). No rule
  applies.

## §4 — Worked walk-through on five GSM8K train_sample cases

Notation: positions written `(sent, tok)`. Lexicon assumed: female-name
markers for Tina, Marion, Erica, Martha, Jane; male-name markers for
Malcolm, Aaron, Carson, Jason, Eric, James, John; UNKNOWN for Georgie.
Kinship lexicon: brother → MALE.

### 4.1 — Case 0001 (Tina, multi-pronoun)

Text (question only, for brevity):

> "Tina makes $18.00 an hour. If **she** works more than 8 hours per shift,
> **she** is eligible … If **she** works 10 hours every day for 5 days,
> how much money does **she** make?"

Registry trajectory:

| Step | Event | Registry |
|---|---|---|
| 1 | Token "Tina" at (0,0) | `[Tina:FEMALE@(0,0)/LEXICON_NAME]` |
| 2 | Pronoun "she" at (1,2) | Filter FEMALE → {Tina}. Single candidate. **Resolve → Tina.** `last_mention(Tina) ← (1,2)`. |
| 3 | "she" at (1,7) | Same → Tina. |
| 4 | "she" at (2,2) | Same → Tina. |
| 5 | "she" at (2,11) | Same → Tina. |

All four pronouns resolve. Final binding for the question slot: Tina. Old
heuristic: identical outcome. **Agreement.**

### 4.2 — Case 0010 (Yun, Marion — no question pronoun)

Text:

> "Yun had 20 paperclips initially, but then lost 12. Marion has 1/4 more
> than what Yun currently has, plus 7. How many paperclips does **Marion**
> have?"

The question is a direct proper-noun binding (no pronoun). Registry:

| Step | Event | Registry |
|---|---|---|
| 1 | "Yun" at (0,0) | `[Yun:UNKNOWN@(0,0)/LEXICON_NAME]` (Yun absent from name lexicon → UNKNOWN) |
| 2 | "Marion" at (1,0) | `[Yun:UNKNOWN, Marion:UNKNOWN@(1,0)]` |
| 3 | Question "Marion" at (2,5) | Proper-noun direct binding (no pronoun → no Rule). `last_mention(Marion) ← (2,5)`. |

No pronoun resolution required. Question slot binds to Marion directly. Old
heuristic: same. **Agreement.** This case demonstrates that the policy does
not perturb proper-noun-only questions.

### 4.3 — Case 0027 (Malcolm, "he")

Text (compressed):

> "Malcolm has 240 followers on Instagram and 500 followers on Facebook.
> The number of followers **he** has on Twitter is half … and **he** has
> 510 more followers on Youtube than **he** has on TikTok. How many
> followers does Malcolm have on all his social media?"

Registry:

| Step | Event | Registry |
|---|---|---|
| 1 | "Malcolm" at (0,0) | `[Malcolm:MALE@(0,0)/LEXICON_NAME]` |
| 2 | "he" at (1,7) | Filter MALE → {Malcolm}. Resolve. |
| 3 | "he" at (1,18) | Same. |
| 4 | "he" at (1,22) | Same. |
| 5 | "Malcolm" at (2,4) | Proper-noun direct binding (question). |

All pronouns resolve to Malcolm. Old heuristic: same. **Agreement.**

### 4.4 — Case 0017 (Jason and Eric, "him")

Text:

> "Jason has a carriage house that he rents out. He's charging $50.00 per
> day or $500.00 for 14 days. Eric wants to rent the house for 20 days. How
> much will it cost **him**?"

Registry trajectory (showing only entries/updates relevant to "him"):

| Step | Event | Registry |
|---|---|---|
| 1 | "Jason" at (0,0) | `[Jason:MALE@(0,0)]` |
| 2 | "he" at (0,6) | Filter MALE → {Jason}. Resolve. `last_mention(Jason) ← (0,6)` |
| 3 | "He" at (1,0) | Same → Jason. `last_mention(Jason) ← (1,0)` |
| 4 | "Eric" at (2,0) | `[Jason:MALE, Eric:MALE@(2,0)]` |
| 5 | "him" at (3,7) | Filter MALE → {Jason, Eric}. `dist(Jason, him) = (3,7) − (1,0)` = ~12 tokens + 2*SENTENCE_PENALTY = 14. `dist(Eric, him) = (3,7) − (2,0)` = ~7 + SENTENCE_PENALTY = 8. Gap = 6 ≥ RECENCY_GAP_MIN. **Resolve → Eric.** |

Old heuristic: distinct males = 2 → refuses (F2). New policy: resolves to
Eric via recency, with the gap comfortably above the ambiguity window. The
ground-truth solver path requires the cost to be billed to Eric (the
renter), so the binding is correct. **Disagreement; new policy correct.**

### 4.5 — Case 0033 (Rachel + kinship)

Text:

> "Rachel is 12 years old, and **her grandfather** is 7 times her age.
> **Her mother** is half grandfather's age, and **her father** is 5 years
> older than her mother. How old will Rachel's father be when **she** is 25
> years old?"

Registry trajectory:

| Step | Event | Registry |
|---|---|---|
| 1 | "Rachel" at (0,0) | `[Rachel:FEMALE@(0,0)]` |
| 2 | Possessive "her" + kinship "grandfather" at (0,4–5) | Possessor resolves (FEMALE filter → Rachel). Kinship entry created. `[Rachel:FEMALE, Rachel.grandfather:MALE@(0,5)/KINSHIP, anchor=Rachel]` |
| 3 | Possessive "Her" + "mother" at (1,0–1) | Anchor=Rachel. `[…, Rachel.mother:FEMALE@(1,1)/KINSHIP]` |
| 4 | Possessive "her" + "father" at (1,7–8) | Anchor=Rachel. `[…, Rachel.father:MALE@(1,8)/KINSHIP]` |
| 5 | Possessive "Rachel's" + "father" at (2,2–3) | Re-mention; `last_mention(Rachel.father) ← (2,3)`. |
| 6 | "she" at (2,8) | Filter FEMALE → {Rachel, Rachel.mother}. dist(Rachel) measured from last_mention (0,0)+penalties; dist(Rachel.mother) measured from (1,1)+penalties. Rachel.mother is closer. Gap above RECENCY_GAP_MIN? **No — Rachel.mother's last mention is far back, Rachel has not been re-mentioned by name since (0,0).** Compute: Rachel.mother at (1,1), Rachel at (0,0). Pronoun at (2,8). dist(Rachel) ≈ 8 + 2 = 10. dist(Rachel.mother) ≈ 7 + 1 = 8. Gap = 2 == RECENCY_GAP_MIN. Strict form: **refuse with `ambiguous_pronoun_referent`**, candidates {Rachel, Rachel.mother}. |

Old heuristic: distinct female proper names = 1 (Rachel) → resolves to
Rachel. New policy: refuses on ambiguity because kinship-introduced female
entities are in scope. The ground truth is Rachel ("when she is 25"). The
new policy is **more conservative** here: it refuses a case the heuristic
would have resolved correctly, but does so by surfacing a genuine
ambiguity (the surface form does not exclude "when her mother is 25" as a
reading). The refusal flows to the teaching loop and motivates the
role-aware extension (subject-bias for the original named entity) as a
later sub-ADR. **Disagreement; new policy refuses, old policy resolves
correctly by luck — see §5 for the wrong = 0 reasoning.**

## §5 — Disagreement enumeration

Three disagreements between the old heuristic and the new policy are
enumerated below. Verdict is given under the wrong = 0 discipline (correct,
refuse, or wrong).

### D1 — Case 0017 (Jason + Eric, "him")

| Policy | Output | Verdict |
|---|---|---|
| Old heuristic | refuse (2 distinct males) | refuse |
| New policy | resolve → Eric (recency) | **correct** |

**Reasoning.** The new policy uses information the old does not (mention
order), preserves refuse-on-ambiguity for the close-call window, and
resolves where the gap is wide. wrong = 0 is preserved because the gap
threshold (`RECENCY_GAP_MIN`) is set strictly enough that close cases still
refuse.

### D2 — Case 0034 (Georgie, "he")

| Policy | Output | Verdict |
|---|---|---|
| Old heuristic | refuse (Georgie ∉ `_MALE_NAMES`) | refuse |
| New policy | resolve → Georgie via single-salient-entity back-fill (§2.2 step 5) | **correct** |

**Reasoning.** Georgie is the only animate entity in the problem; "he" has
exactly one possible antecedent. The back-fill is conservative because it
only fires when there is *exactly one* UNKNOWN-gendered entity in the
entire registry. The old heuristic refused because the closed-set name
whitelist did not contain Georgie. wrong = 0 is preserved because the
single-salient rule cannot bind a pronoun to a wrong entity — there is no
other entity to be wrong about.

### D3 — Case 0026 (Aaron and Carson, "they")

| Policy | Output | Verdict |
|---|---|---|
| Old heuristic | refuse (`they` unconditionally refused) | refuse |
| New policy | resolve → group {Aaron, Carson} via conjunction-closed GROUP entry (§2.1 case 3) | **correct** |

**Reasoning.** "Aaron and his brother Carson each saved up $40" closes a
conjunction frame that registers a GROUP entry. The question "how many
scoops did they each buy?" filters to GROUP entries and finds the unique
match. The downstream binding produces the per-member result via the
distributive modifier `each`. The old heuristic refused on every `they`
regardless of registry state. wrong = 0 is preserved because GROUP
resolution is enabled only when a conjunction frame has closed; absent that
frame, `they` falls through to R2.

### D4 — Case 0033 (Rachel + kin, "she") — **counter-direction**

For completeness, the one case where new is *more conservative* than old:

| Policy | Output | Verdict |
|---|---|---|
| Old heuristic | resolve → Rachel (only female proper noun) | correct |
| New policy | refuse with ambiguous_pronoun_referent ({Rachel, Rachel.mother}) | refuse |

**Reasoning.** The new policy has more information (kinship entities in
registry) and uses it to flag a genuine surface ambiguity. The old
heuristic resolves correctly only because it cannot see Rachel.mother. The
wrong = 0 discipline preserves correctness either way (refusal is not
wrong); the cost is one extra refused case at Phase 1, which the teaching
loop turns into evidence for a role-bias sub-ADR.

D1 + D2 + D3 each improve a refusal into a correct resolution; D4
exchanges a lucky correct for a principled refusal. The net effect on the
GSM8K train_sample is monotonically positive on `correct` and zero on
`wrong`, which is exactly the operating regime ADR-0164 requires.

## §6 — Constraints

This ADR inherits ADR-0164 §Constraints in full. Additionally:

1. **Strict-gap recency.** `RECENCY_GAP_MIN` is ratified at 2 tokens.
   Adjustments require a sub-ADR and capability-lane re-run.
2. **Single-salient back-fill is exact.** The UNKNOWN → certain-gender
   back-fill (§2.2 step 5) fires **only** when the registry has exactly one
   UNKNOWN-gendered entity *globally*. Two UNKNOWN entries kill the rule;
   neither is back-filled.
3. **No probabilistic gender inference.** The lexicon is the only source of
   certain gender at entity creation. Back-fill is co-reference, not
   statistical inference.
4. **No syntactic-role bias at Phase 1.** Subject preference, possessor
   demotion, and similar heuristics are out of scope for this ADR. They
   require independent measurement and a separate sub-ADR.
5. **Append-only registry.** Re-mentions update positions; entries do not
   merge, split, or get deleted within a problem. Gender back-fill
   *updates* an entry but does not change its identity.
6. **Resolution log is part of trace.** Every Resolution event is part of
   the canonical-bytes serialization that feeds `trace_hash` per CLAUDE.md
   §Runtime Surface Contract.

## §7 — Acceptance criteria (Proposed → Accepted)

This ADR moves to **Accepted** when, alongside ADR-0164 Phase 1 acceptance:

1. `EntityRegistry`, `EntityEntry`, and `Resolution` types exist as
   frozen-dataclasses under `generate/comprehension/registry.py` with
   canonical-bytes serialization tests.
2. The policy in §2 is implemented behind the reader's
   `entity_pronoun` category dispatch, with unit tests covering:
   - All five worked walk-throughs (§4) byte-equal to the ADR.
   - All three disagreement cases (§5 D1–D3) producing the documented
     outputs.
   - The counter-direction case (§5 D4) producing the documented refusal.
   - Single-salient back-fill firing once and only once per problem in
     the F1-style cases.
   - R1 and R2 refusal reasons emitted with full position and candidate
     evidence.
3. Capability lanes G1–G5, S1 remain at 100% `wrong = 0`.
4. `core eval cognition` and the GSM8K train_sample runner show monotonic
   non-decrease in `correct` and zero `wrong` against the post-D.2
   baseline.

## §8 — Open follow-ups (out of scope for this ADR)

- **Syntactic-role bias** (subject-preference): a sub-ADR after Phase 1
  evidence shows where R1 refusals cluster on subject-vs-object
  ambiguity.
- **Cross-sentence anaphora window beyond two sentences**: currently
  bounded by `SENTENCE_PENALTY = 1` per boundary; longer chains may need
  a saturation curve. Empirical question.
- **Pronoun chains** ("she … her … hers"): currently each pronoun resolves
  independently against the registry. Chain coherence (require all three
  to bind to the same entity) is a candidate strengthening.
- **Mixed-gender group membership**: §2.2 step 2 allows GROUP ↔ single
  gender via membership, but Phase 1 does not exercise this. Defer until
  a real GSM8K case demands it.

## Cross-references

- **Parent:** [ADR-0164 — Incremental Comprehension Reader](./ADR-0164-incremental-comprehension-reader.md)
- **Companion:** ADR-0164.3 — `ProblemReadingState` and cross-sentence
  registry (carries this `EntityRegistry` as one of its fields).
- **Resolves:** ADR-0164 §Open question #3.
- **Substrate that survives:** the binding graph still consumes
  `BoundUnknown(entity, unit, …)` tuples whose `entity` field is now
  sourced from the registry rather than the regex name whitelist.
- **HITL corridor:** R1/R2 refusals carry the registry snapshot into the
  contemplation queue (ADR-0150/0152/0155/0161) for review.
- **Anti-overfitting:** ADR-0114a — the policy is closed-set in its
  vocabulary (lexicon-driven), conservative in its dispatch
  (refuse-on-ambiguity), and falsifiable on the capability lanes.
- **Thesis:** `[[thesis-decoding-not-generating]]` — the registry is what
  "found" looks like for an entity. Each pronoun narrows the candidate
  set; the resolution is the accumulation, not a guess.