Don't Let It Hallucinate: Premise Verification via Retrieval-Augmented Logical Reasoning
Yuehan Qin, Shawn Li, Yi Nian, Xinyan Velocity Yu, Yue Zhao, Xuezhe Ma
TL;DR
This work targets factual hallucinations in LLMs caused by false premises in user queries. It introduces a retrieval-augmented logical reasoning framework that converts queries into a structured logical form, verifies premises against a knowledge graph via retrieval-augmented generation, and informs the LLM with verification results to maintain factual consistency. Experiments on KG-FPQ demonstrate improved false-premise detection and reduced hallucinations without requiring model logits or extensive fine-tuning, with performance benefiting from logic-grounded retrieval, especially for multi-hop reasoning. The approach offers a practical pathway to integrate proactive factual checks into LLM pipelines, enhancing robustness and reliability in real-time applications.
Abstract
Large language models (LLMs) have shown substantial capacity for generating fluent, contextually appropriate responses. However, they can produce hallucinated outputs, especially when a user query includes one or more false premises-claims that contradict established facts. Such premises can mislead LLMs into offering fabricated or misleading details. Existing approaches include pretraining, fine-tuning, and inference-time techniques that often rely on access to logits or address hallucinations after they occur. These methods tend to be computationally expensive, require extensive training data, or lack proactive mechanisms to prevent hallucination before generation, limiting their efficiency in real-time applications. We propose a retrieval-based framework that identifies and addresses false premises before generation. Our method first transforms a user's query into a logical representation, then applies retrieval-augmented generation (RAG) to assess the validity of each premise using factual sources. Finally, we incorporate the verification results into the LLM's prompt to maintain factual consistency in the final output. Experiments show that this approach effectively reduces hallucinations, improves factual accuracy, and does not require access to model logits or large-scale fine-tuning.
