5 explicit-negation queries ("Need Forklift Operators in Aurora IL,
NOT in Detroit", "excluding Cornerstone Fabrication roster", etc.)
through the standard playbook_lift harness. Goal: characterize
whether the substrate has negation handling or silently treats
"NOT X" as "X".
Headline: substrate has zero negation handling. Cosine on dense
embeddings tokenizes "NOT in Detroit" identical to "in Detroit"
plus noise — there is no logical-quantifier representation in the
embedding space. This is a structural property of dense embeddings,
not a substrate bug.
Per-query observations:
- Q1 (Aurora IL, NOT Detroit): all top-10 rated 1-2/5 by judge
- Q2 (NOT Beacon Freight): top-1 rated 4/5 — accidentally OK
because role+city signal pulled non-Beacon worker naturally
- Q3 (excluding Cornerstone): unanimous 1/5 across top-10
- Q4 (NOT Detroit-area): all top-10 rated 1-2/5
- Q5 (exclude Heritage Foods): top-1 rated 4/5 — accidentally OK
The judge IS the safety net: when retrieval can't honor the
constraint, the judge refuses to approve any result. That's the
honesty signal — `discovery=0` for the run aggregates it.
No code change. The architectural answer for production is:
- UI surfaces an "exclude" affordance that populates ExcludeIDs
(already supported, added in multi-coord stress 200-worker swap)
- Coordinators don't type natural-language negation — they click
- Substrate's role: surface honesty signal (judge ratings) + don't
pretend to honor unparseable constraints
Adding NL-negation handling at the substrate level would be product
debt — it would let coordinators type sloppier queries that
silently fail when the LLM extractor misses a phrasing. Don't ship
until production traffic demonstrates demand for it.
Findings: reports/reality-tests/real_005_findings.md.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>