The Ctrl-G framework is designed to enforce logical constraints on Large Language Model (LLM) outputs. It integrates any LLM with a Hidden Markov Model (HMM) and uses deterministic finite automata (DFA) to represent logical constraints. Ctrl-G distills an HMM to approximate the LLM's distribution and guide it during inference, ensuring adherence to constraints without requiring further training of the LLM or HMM. This makes Ctrl-G a scalable and flexible solution for applications requiring controlled text generation.
Current methods to impose constraints on LLMs include search-based decoding algorithms and auxiliary neural classifiers4. These approaches either need to scale better with sequence length or require extensive training for each new constraint4. The GeLaTo framework introduced tractable generative models to guide LLMs but was limited to specific types of constraints4.
Large language models (LLMs) face challenges in consistently adhering to logical constraints during text generation, such as avoiding certain words, maintaining coherence, or following specific logical sequences. The difficulty lies in conditioning LLMs to reliably incorporate these constraints without additional training or complex algorithms.