Hypothesis Test — Logical Inconclusiveness ≈ NLI Neutral

Formal verification of structural analogy between two reasoning frameworks  ·  agent_hypothesis_verifier

Sushma Anand Akoju

Hypothesis

H₁ — Research Hypothesis
Logical inconclusiveness is structurally analogous to NLI Neutral when the same toy KB facts are served as premises to both a formal logic agent and an NLI agent.

The hypothesis decomposes into three testable sub-claims:

H₁(a) — Inconclusive → Neutral: Every item where logic_verdict = Inconclusive should have nli_label = Neutral and neutral_classification = Neutral.
H₁(b) — Conclusive → Not Neutral: Every item where logic_verdict ∈ {True, False} should have nli_label ∈ {Entailment, Contradiction} and neutral_classification = Not Neutral.
H₁(c) — Structural (not coincidental): The correspondence arises from the same root cause — a KB that sustains two mutually exclusive world models simultaneously — not from surface-level string matching or model bias.

Theoretical basis

The NLI label Neutral is defined as: the hypothesis is possible but not guaranteed under the premise set — neither entailed nor contradicted. The logical verdict Inconclusive is defined as: the KB is satisfiable under two interpretations that yield opposite truth values for the query, so no single truth value can be assigned.

Both conditions are triggered by the same KB structural pattern used in this dataset: a polysemous noun (bat, bank, wave…) with two senses defined in the KB, mutual-exclusion axioms that would disambiguate if the individual were typed, and a contextual observation predicate that is compatible with both senses. The prediction is that both formalisms will register this ambiguity as their respective "undecided" label.

Experimental Setup

Same input, two reasoning frameworks

agent_logic
Possible-worlds analysis
Closed-World Assumption
claude-haiku
← same KB + query →
agent_NLI
MacCartney Natural Logic
Monotonicity calculus
claude-haiku
→
agent_hypothesis_verifier
Precision · Recall · F1
Exception classification
Verdict

Dataset

PropertyValue
Sourceresults/eval_output.jsonl
KB entries8 polysemous nouns (bat, head, nail, paper, bank, mouse, pitcher, wave)
Query types per KB4 (inconclusive · conclusive · neutral_query · not_neutral)
Total items32
Logic backboneclaude-haiku (agent_logic)
NLI backboneclaude-haiku (agent_NLI)
Synthesizerclaude-sonnet (agent_eval)

Expected correspondence table

Logic verdict Expected NLI label Expected Neutral class Query types that target this
InconclusiveNeutralNeutralinconclusive · neutral_query
TrueEntailmentNot Neutralconclusive · not_neutral
FalseContradictionNot Neutralconclusive · not_neutral
Paradoxflag for manual review — not expected in this dataset

Verification Agent — agent_hypothesis_verifier

The agent reads the pre-computed results/eval_output.jsonl (no re-running logic or NLI agents) and runs a 6-step analysis:

0
Load research context

Reads papers, concepts, experiments, and reflection files to ground fallacy and failure-mode analysis in the documented KB design rationale.

1
Parse all 32 records

Builds an internal table from eval_output.jsonl with logic_verdict, nli_label, neutral_classification, query_type, and dataset_quality_flag.

2
Compute correspondence metrics

Precision, Recall, F1 for H₁(a) and H₁(b) in aggregate; then stratified by query type (4 groups × 8 items) and by KB key (8 keys × 4 items).

3
Exception classification

Every item where the expected mapping fails is classified into a documented failure mode:

FM1 Query-predicate disambiguation blindspot (logic agent)   FM2 Universal KB scoping (logic returns True via undiscriminating universal)   FM3 NLI exclusion-chain composition failure   FM4 Dataset annotation error   FM5 Novel failure mode

4
Structural analogy test (qualitative)

For the clearest GOLD matches: do both agents cite the same KB sentences as the ambiguity root cause? For the clearest exceptions: does the failure disprove the structural analogy or merely reveal an agent implementation gap?

5
Verdict

Assigns SUPPORTED / PARTIALLY_SUPPORTED / REFUTED based on metric thresholds (see below), with a one-paragraph justification citing specific values.

6
Implications and recommendations

What the result means for using NLI Neutral as a proxy for logical inconclusiveness, limitations of the test, and recommended next steps (larger dataset, cross-domain KBs, multi-model replication).

Verdict thresholds

SUPPORTED
Overall rate ≥ 80%
precision_inc ≥ 0.90
recall_inc ≥ 0.80
All exceptions = FM1–FM3
PARTIALLY SUPPORTED
Overall rate 60–79%
OR precision ≥ 0.80 but
recall < 0.80
OR some FM4 exceptions
REFUTED
Overall rate < 60%
OR structural mismatch
on GOLD items
OR systematic FM5

How to Run

From the claude-code-agentic-simulation/ directory:

@agent_hypothesis_verifier

The agent reads results/eval_output.jsonl (already generated) and writes its full report to results/hypothesis_test_report.md. No additional inputs required — all pre-computed eval results are used as-is.

Output

The agent writes results/hypothesis_test_report.md containing:

Prior Evidence from Evaluation

From the Evaluation Report, the pipeline achieved 71.9% MCQ accuracy (23/32). The correspondence between Inconclusive and Neutral is already visible in the per-key results:

Query typeTotal Expected: Inc↔Neutral Observed GOLD rate Notes
inconclusive8 H₁(a) test 8/8 GOLD All agents agree Inconclusive/Neutral across all 8 keys
neutral_query8 H₁(a) meta-NLI 7/8 GOLD paper/neu both agents return Not Neutral — KB scoping flaw
conclusive8 H₁(b) test 2/8 GOLD bat/con (NLI applies chain), paper/con (both agree); others fail FM1/FM2
not_neutral8 H₁(b) test 3/8 GOLD pitcher/not, paper/not, wave/not succeed; others FM1/FM2

The inconclusive/neutral_query rows show near-perfect H₁(a) support. The conclusive/not_neutral rows show partial H₁(b) support — failures are systematic (FM1/FM2), not random. The agent_hypothesis_verifier will compute the precise metrics and issue the formal verdict.