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).
GB-2 first increment (ADR-0178). compose_sequential() adds the structure the blunt
MS-3 shapes couldn't reach: a same-unit quantity LIST sums (additive cue), and any
stated comparative scales the sum (sum-then-scale, 0024-family). Op-per-step from
text structure (list => add; comparative => scale); operands are text quantities
(grounded) + comparative steps (cue-grounded) on the flat left-fold — no derived-
intermediate model needed (running value is the intermediate).
Deliberately narrow: same-unit lists only. A stated comparative is ALWAYS applied
(no bare-vs-scaled self-disagreement). A product base over the same list is added
WITHOUT a comparative tail purely as a disagreement-safety candidate -> a same-unit
list that also carries a mult cue (ambiguous) REFUSES. Product-of-all/cross-unit
products stay MS-3's job (avoids the product x comparative blowups a blunt all-bases
composer produced: 0024 -> 4.3M).
Clean-case capability proven: 8 tests (list-sum, sum-then-double/triple, mixed-units
refuse, ambiguous-disagreement refuse, determinism). Honest practice result: 3/2/45
— NO new flips (extraction wall: real cases like 0024 extract non-uniform units
'36 on' so they aren't seen as same-unit lists), 2 sealed eliminations (0037/0039:
list-sum was the wrong structure -> learning signal). Coverage gated by extraction
richness + cue precision, as predicted.
Sealed; serving untouched. Full derivation surface 53/53; ruff clean; smoke 67.
Continuation: richer relational ops (per/each->multiply, more/older->add), branch/
DAG (0033), and the extraction richness (uniform-unit extraction) that unblocks this
on real cases.
