Promotes the title-relevance sidecar (diagnose_title_relevance,
qa/inspect.py) to a hard check inside both verify_claim_lattice
and verify_claim_lattice_json. New violation kind TITLE_MISMATCH;
demote-to-HYBRID semantics matching the existing WARRANT_MISSING
pattern.
Catches the 2026-05-02 fox-surfaced retrieval-driven hallucination
class:
Q: "explain spin glass modeling & tensors?"
Pre-Rule-8: EVIDENCE-WARRANTED 1/1, claim cited to Quantum
chromodynamics chunk (single-line "See Also: spin
glass" reference). Token-coverage check passed
accidentally on shared physics vocabulary.
Post-Rule-8: POINTER-LINKED-PARTIAL · title mismatch 1/1.
Cited source title 'Quantum chromodynamics' shares
zero stemmed tokens with claim's {spin, glass,
modeling, tensor, ...} → demote.
Implementation:
_claim_title_overlap(claim_text, source_title) returns True iff
the source title shares ≥1 stemmed content token with the claim.
Uses qa.evidence._content_tokens (≥4-char, post-stopword) and
inline minimal stem (s-strip on tokens >4 chars, skip ss-enders)
to avoid an import cycle.
Per-claim loop in both verifiers checks every cited source's
title; ANY-match suffices (only TITLE_MISMATCH when ALL cited
titles miss). Vacuous-pass when claim or title has no
extractable tokens.
Renderer (_ladder_rung_for_lattice) treats TITLE_MISMATCH
alongside WARRANT_MISSING as the POINTER-LINKED-triggering
signal — both indicate citation/claim structural misalignment.
_render_warrant_tail surfaces "· title mismatch" alongside
"· warrant missing" so an operator sees the specific failure
mode at the audit-line.
Test fixtures updated where the synthetic claims were too minimal
(e.g. "Velociraptors are shown attacking workers" cited to
"Jurassic Park (film)" — claim had no topic anchor). Real model
output naturally references the topic (the model sees the title
in the evidence map and uses it); the fixture revisions reflect
that. 4 new tests in test_verify_json.py covering the helper +
end-to-end TITLE_MISMATCH demote.
Live verification:
Spin-glass query: POINTER-LINKED-PARTIAL · title mismatch ✓
Homer/Mr. Burns: EVIDENCE-WARRANTED ✓ (no regression)
CLAUDE.md updated with the Rule 8 convention; existing
diagnose_title_relevance sidecar marked legacy / dict-form for
per-cache-key inspect use.
Full suite: 738 passed (was 734, +4).
russell@unturf.com
0d8eed0df8