By Antonia Wüst
Review Details
Reviewer has chosen not to be Anonymous
Overall Impression: Good
Content:
Technical Quality of the paper: Good
Originality of the paper: Yes, but limited
Adequacy of the bibliography: Yes, but see detailed comments
Presentation:
Adequacy of the abstract: Yes
Introduction: background and motivation: Good
Organization of the paper: Satisfactory
Level of English: Satisfactory
Overall presentation: Excellent
Detailed Comments:
- Summary -
The paper proposes a trust-centric neuro-symbolic architecture for verifying LLM-generated claims. The pipeline translates natural language into FOL, verifies claims against a provenance-rich knowledge graph using trust scores, and produces explanations linked to the supporting evidence. The main contribution is the incorporation of provenance signals such as signatures, reputation, freshness, completeness, and corroboration into the verification process.
I find the problem important and the overall architecture interesting, particularly the explicit treatment of conflicting or insufficient evidence through an Indeterminate verdict. However, several central claims are stronger than what is currently implemented and evaluated.
- Reasons to accept -
The paper addresses an important problem for trustworthy LLM systems and fits the scope of the journal well.
The integration of provenance and source credibility into neuro-symbolic verification is promising. The five-component trust score is interpretable, and the conflict-aware verdict mechanism provides a useful way of avoiding forced decisions under weak or contradictory evidence.
The architecture is clearly structured, and the illustrative walkthrough in Section 3.5 is particularly helpful for understanding the intended behavior of the system.
- Reasons for major revision -
1. The role and contribution of differentiability are unclear
Equation 6 introduces a trust-weighted differentiable satisfiability objective and states that gradient updates to θ prioritise high-trust evidence. However, it is not clear what f_θ is trained to represent, how it is trained, or how its learned satisfaction values influence the final verdict.
The verdict in Equations 7 and 8 appears to depend directly on provenance-derived trust weights through max aggregation and fixed thresholds, without an obvious role for the differentiable component. The authors should clarify the connection between the differentiable objective, the learned neural predicates, and the final verification decision, and explain what differentiability contributes beyond a symbolic verifier with provenance-weighted evidence.
2. The differentiable verifier does not appear to be part of the evaluated system
Relatedly, the conclusion states that a future version will implement the trust-weighted LTN objective in LTNtorch, replacing the current rule-based retrieval and verdict mechanism with a learned differentiable verification function.
This makes the status of the central technical contribution unclear and Table 1 is not really transparent on this. Ideally, the differentiable verifier should be implemented and evaluated in this paper rather than deferred to follow-up work.
3. The reported "end-to-end" experiment bypasses Stage A
Section 5.2 states that all three stages are executed in sequence, but the pipeline configuration subsequently states that Stage A is bypassed and gold-standard FOL representations are used in order to isolate Stage B and Stage C.
I therefore do not think the resulting experiment should be described as a full end-to-end evaluation of the proposed architecture. One of the central challenges motivating the paper is precisely the possibility that natural-language claims are grounded incorrectly. These errors cannot propagate into the reported system-level results because gold FOL is supplied directly.
The authors should either run the complete pipeline using predicted Stage A outputs or consistently describe the current experiment as an evaluation of Stages B and C conditioned on gold-standard logical forms.
4. No end-to-end accuracy result is currently reported
Section 4 identifies end-to-end verdict accuracy and E3 macro-F1 as important evaluation criteria. However, the current experiment only reports the distribution of outputs: 30 Verified, 1 Falsified, and 19 Indeterminate.
The authors explicitly acknowledge that the current dataset does not contain independently expert-validated ground-truth verdicts sufficient to compute E3.
A verdict distribution does not establish verification accuracy. For example, producing Indeterminate frequently may reflect desirable conservatism, but without an independent ground truth it is not possible to determine whether these abstentions are appropriate.
This substantially limits claims about factual verification performance, "behavioural correctness," or reduction in hallucination. At minimum, these claims should be narrowed. Preferably, the authors should provide independently validated verdict labels and report accuracy, macro-F1, and error analysis.
5. The proposed ablations and relevant baselines are not evaluated
Section 4.3 defines Neural-Only, Standard RAG, Unweighted Verifier, Verdict-Only, and Citations-Only baselines. However, these comparisons are not reported in Section 5 and are explicitly deferred to future work.
Without the Unweighted Verifier baseline in particular, the current experiments do not establish that provenance weighting improves verification outcomes relative to the same symbolic verifier with uniform evidence weights.
The related-work section also discusses strong existing approaches such as CoVe and KG-CRAFT. KG-CRAFT is described as achieving state-of-the-art results on two real-world fact-checking datasets, yet there is no empirical comparison to it or another competitive KG-based verification approach.
I do not necessarily expect all of these systems to be directly comparable on the authors' medical dataset, but the paper should contain at least one meaningful empirical baseline that isolates the contribution of the proposed trust mechanism.
6. The novelty claim should be narrowed and the related-work discussion expanded.
The statement that "no existing differentiable logic framework incorporates source credibility into the reasoning objective" appears too broad. In particular, ClaimEval (Samadi et al., AAAI 2016) jointly estimates source credibility and claim correctness using Probabilistic Soft Logic, representing credibility relations as first-order rules with continuous truth values and Łukasiewicz soft logic. This appears closely related to the proposed use of trust within a soft logical reasoning objective and should be discussed explicitly. The authors should position their contribution more precisely, perhaps around the particular combination of provenance signals, cryptographic signatures, and LTN-style reasoning rather than source credibility in soft reasoning more generally.
7. The trust scores require more methodological detail
The reputation values used in the experiment are manually assigned by the authors using a "public registry." The paper should explain how these values are derived and how the other trust signals would be obtained in practice.
It should also clarify whether the RSA signatures attributed to sources such as WHO and EMA are genuine source-issued signatures or simulated signatures created for the experiment. This distinction seems important for assessing the practical applicability of the method.
8. Stage A's consistency check appears to conflate incorrect grounding with factual contradiction
After translation, the paper checks whether Φ ∪ KB entails a contradiction. If so, it triggers reparsing or manual review. Algorithm 1 instead returns an Indeterminate verdict before Stage B.
This raises a conceptual concern. If a claim is correctly parsed but is contradicted by the knowledge base, this seems like precisely the type of evidence that should be handled by Stage B as negative evidence and potentially produce a Falsified verdict.
For example, if the claim is P(a) and the KB contains ¬P(a), the contradiction does not necessarily imply a parsing error. Did the authors consider this case, or did I misunderstand something there?
9. The claim-level aggregation rule requires additional justification
Equation 9 states that an overall claim is Falsified only if at least one constituent formula is Falsified and none is Indeterminate.
If one constituent is Falsified and all others are Verified, the resulting Falsified verdict is straightforward. However, if one constituent is clearly Falsified while another is Indeterminate, the overall claim becomes Indeterminate.
For a conjunctive claim, this differs from classical logic, where one false conjunct is sufficient to falsify the conjunction regardless of whether another conjunct is unknown. I understand that this may be an intentional safety-oriented or epistemic policy, but the rationale for allowing Indeterminate to dominate Falsified should be explained more clearly.
- Further comments -
The selection procedure for the 254 FOLIO examples should be reported, including whether they overlap with LogicLLaMA's fine-tuning data. The paper also states that tree-edit distance is reported as a soft grounding metric, but I could not find this result in Section 5.
Finally, there is some inconsistency between the abstract's description of the medical claims as "expert-annotated" and the later statement that they were author-annotated and not independently clinically validated.
- Overall assessment -
I see merit in the central idea of incorporating provenance and source quality into neuro-symbolic claim verification, and I believe the architecture could make a useful contribution. However, the current manuscript presents a stronger empirical and technical contribution than the reported experiments presently support.
In particular, the role of differentiability is not sufficiently clear, the differentiable trust-weighted verifier does not appear to be part of the evaluated proof of concept, the reported system-level experiment bypasses semantic grounding, ground-truth verdict accuracy is not yet available, the proposed ablations are not executed, and important trust metadata is manually constructed.
I therefore recommend major revisions. A revised paper should either implement and evaluate the complete proposed architecture, including the differentiable trust-weighted reasoning objective and meaningful baselines, or reposition the manuscript more clearly as an architectural framework and preliminary proof of concept, with corresponding claims of novelty, implementation maturity, and empirical validation narrowed accordingly.