contradiction_detection: 0.50 → 1.00 contradiction_flag_rate,
1.00 → 0.00 false_flag_rate. Lane graduates overall.
TeachingStore.add now runs a coherence checker on every new proposal.
Two detection paths, both require subject token overlap:
Typed path — both new and prior parse to triples with the same
relation. Tails must differ in negation/opposition polarity AND
share ≥1 content token. Catches (truth, is, coherence) ↔
(truth, is, not coherence).
Text fallback — at least one side failed to parse a triple (e.g.
relation predicate "depends" not in the cognition pack lexicon
yet). Raw correction texts must differ in polarity AND share ≥2
non-discourse content tokens. ≥2 threshold prevents
single-shared-subject false positives on unrelated corrections.
Catches "meaning depends on use" vs "meaning is independent of use".
On detection, BOTH proposals (new and conflicting prior) transition
to EpistemicStatus.CONTESTED. ADR-0021: CONTESTED is not admissible
as evidence until a coherence judgment ratifies one direction or
falsifies the other.
Runner side: v1 versor-spike heuristic retired. The new CONTESTED
signal is the only one that drives `flagged`. versor_delta retained
in the record for telemetry.
CLAIMS.md Tier 4.5 contradiction rows CLOSED — completes the
truth-seeking schema arc. All red Tier 4.5 rows from the audit are
now green. docs/truth_seeking_schema.md §"Contradiction detection
is not implemented" closed.
Verified: smoke (67), teaching (17), cognition (121), runtime (19),
architectural invariants (40) — all green.