PR-6d adds the partition frame: combine all parts into a total, then split that
total equally into N containers. r1-06-subtotal-reused moves refused → correct —
the FIRST case where the divisor applies to a DERIVED symbol (the total), not a
directly given fact. That is real progress toward GSM8K setup comprehension,
where intermediate quantities are the norm.
Scope (kept narrow on purpose):
No new relation kind.
No new arithmetic operation.
No rational support.
No rounding/flooring.
No serving path touched.
The frame reuses the already-ratified pieces — SumOf(parts) + Div(Symbol(total),
Literal(N)) → divide_by — so this PR is reader-only (no IR / admissibility /
oracle / signature change).
Frame grammar:
"They combine their <unit> and split them equally into N <containers>."
+ "How many <unit> are in each <container>?"
-> total = sum(all facts); per_<container> = total / N; ask per_<container>.
wrong=0 boundaries:
- Exact-divisibility still gates the ANSWER, now over a derived total: 5+6=11,
11/3 is non-exact -> the setup reads correctly but the answer REFUSES (never
floors). Setup comprehension and answer exactness are cleanly separated.
- Partition/query coherence: a partition is read ONLY together with its
"in each <container>" query (and vice versa); container mismatch (box vs jar)
refuses. Prevents over-reading a story detail into an unused derived value.
Meaningful-fail verified: disabling the guard makes a dangling partition
wrongly comprehend.
Gates:
R1 setup: 4 correct / 0 wrong / 6 refused
R1 answers: 4 correct / 0 wrong / 6 refused / setup_wrong 0 / gold_error 0
15-case setup: 15 / 0 / 0
97 PR-6d tests + 99 relational/invariant tests green. Reader is off-serving
(no generate.derivation / core.reliability_gate import).
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