Addresses the central review finding: the generative wrong=0 tests compared oracle
VERDICTS, so a misread graph that coincidentally yields the same verdict passed
silently (coincidental correctness in cleaner clothes). This adds the conjugate
check — the reader must recover the EXACT structure the prose encodes, not merely a
verdict-equivalent one.
tests/test_comprehension_structure_preserving.py:
- Structure preservation (all 4 domains): over randomly generated structures
rendered to prose that FULLY determines them, assert projected structure AND
query == ground truth exactly (order-insensitive canonicalization), or refuse.
Empirically this is strictly stronger: under a subject<->predicate premise swap,
361/400 reads are structurally wrong and 307 of those (85%) coincide in verdict
— the answer test misses all 307; the structure test catches all 361.
- Perturbation invariance: meaning-preserving surface changes (premise/clause
reordering, capitalization, extra whitespace) yield the SAME structure.
The existing answer-preservation property tests stay (verdict agreement is still a
valid, separate check — exactly the "assert structure, then separately assert
oracle agreement" the review recommends). Tests-only; no source change; capability
index unchanged. 7 new + 86 comprehension/capability targeted green.
