Grounded scope for GB-3b, the next Gap B move. Measured opportunity: 46/150
additive practice cases are sum-of-all==gold, all currently refusing, all the
single-referent accumulation shape ('X has N. He buys M more.' -> N+M). They
refuse correctly (GB-3a's multi-clause guard / the Alice+Bob hazard); the safe
ones differ by referent identity + a change-verb cue, which GB-3b reads.
Scope covers: the reading (anchor + change steps), the wrong=0-critical referent
model (minimal no-new-actor guard; cross-references ADR-0164.2/.3 + ADR-0174's
multi-actor hazard; deliberately does NOT resurrect the retired gender-blind
resolver), the proof-carrying wrong=0 obligations, the cue-precision coupling
(change cues should finally be reliable, closing CP-2a), the increments, and
honest flip expectations (big chunk in practice-additive; modest train_sample;
serving stays 3/47/0 until ratification).
The mandated lookback review before GB-3 (CLAUDE.md §Lookback Review Discipline)
confirmed the audit's hazards H1/H2/H3 were LIVE: compose_sequential summed
same-unit quantities from the whole problem, merging unrelated referents/scopes
and admitting wrong structures whose value happened to ground:
H1 (second actor's apples) -> 6+4+2 = 12
H2 (comparative on other actor) -> (6+4)*2 = 20
H3 (later depletion event) -> 6+4+3 = 13
Root cause is the audit's G1/D2 drift: GB-2a re-extracts from the whole text and
ignores GB-1's clause structure. The fix is the GB-3 increment — make the composer
clause-scoped (consume segment_clauses), refusing when the licensed structure spans
clauses, because this slice cannot model referents:
- quantities must live in exactly ONE clause (0 or >1 -> refuse);
- a comparative outside that clause -> refuse (unmodelled referent binding).
All three hazards now refuse; all 7 GB-2 single-clause structures preserved
(list-sum, three-item, sum-then-scale, and the mixed-unit/disagreement/too-few
refusals). tests/test_adr_0178_gb3_referent_guard.py would fail against the
pre-guard code (12/20/13), so the obligation is proven, not decorative.
Scope/safety:
- compose_sequential is sealed substrate, not wired to a scorer -> serving
byte-identical 3/47/0 (lane-SHA 8/8, generate_claims --check OK); practice
unchanged 4/1/45. No new test failures (2 pre-existing on main).
- ADR-0178 amended: GB-2 relabelled GB-2a (list slice, drift G1 recorded);
GB-3 split into GB-3a (this referent guard, landed) and GB-3b (constructive
cross-clause chaining, next).
The actual coverage lever (ADR-0177 established cue-precision is its gate+prune,
not the unlock). Gap B = which quantities group via which ops in what order.
The reframe that resolves the rich-search-vs-uniqueness tension: structure-from-
READING, not enumeration. The text encodes its own structure — every gold case
fits a sequential clause-by-clause read (0021 one clause 15x10x3; 0003 48 ->x24
->x0.75; 0024 sum ->x3; 0033 seq chain + branch). So Gap B is comprehension: read
the problem, build the derivation structure as you read, hold alternatives on
ambiguity, reevaluate on lookback. This IS the project's original 'word-to-word
with lookback + problem-solving throughout' articulation, and the synthesis of
reader (0174) + solver/gate (0176) + learning (0177) + packs.
Decision: a comprehension-guided sequential composer — clause-local bounded
sub-derivations combined across clauses via relational cues (per/each/of->multiply,
and-list->sum, comparative->scale, more/older->add, fewer/less->subtract), held-
hypothesis on ambiguity + eliminate/reevaluate (REPOINT ADR-0174's inert reader
substrate from parse to STRUCTURE — where it finally becomes load-bearing), scored
by the 0176 self-verification gate + uniqueness, guided by 0177 cue-precision.
Locality bounds the search; relational cues constrain the cross-clause op so
uniqueness can RESOLVE (not just refuse). Coverage rises only as far as the reading
constrains structure; irreducible ambiguity refuses (wrong=0).
wrong=0 obligations: per-step self-verification, irreducible-ambiguity-refuses,
completeness+uniqueness over the whole structure, no-spurious-structure, determinism,
sealed. Honest hard parts: relational-cue precision (co-dependent with 0177 +
data-starved), clause segmentation, referent binding, branch/DAG (0033 quantity
reuse, GB-5), scale. This is the comprehension core — largest remaining capability;
serving lift materialises here, incrementally. Sub-phases GB-1..GB-6.
