Chain of Logic: Rule-Based Reasoning with Large Language Models

Sergio Servantez, Joe Barrow, Kristian Hammond, Rajiv Jain


Abstract
Rule-based reasoning, a fundamental type of legal reasoning, enables us to draw conclusions by accurately applying a rule to a set of facts. We explore causal language models as rule-based reasoners, specifically with respect to compositional rules - rules consisting of multiple elements which form a complex logical expression. Reasoning about compositional rules is challenging because it requires multiple reasoning steps, and attending to the logical relationships between elements. We introduce a new prompting method, Chain of Logic, which elicits rule-based reasoning through decomposition (solving elements as independent threads of logic), and recomposition (recombining these sub-answers to resolve the underlying logical expression). This method was inspired by the IRAC (Issue, Rule, Application, Conclusion) framework, a sequential reasoning approach used by lawyers. We evaluate chain of logic across eight rule-based reasoning tasks involving three distinct compositional rules from the LegalBench benchmark and demonstrate it consistently outperforms other prompting methods, including chain of thought and self-ask, using open-source and commercial language models.
Anthology ID:
2024.findings-acl.159
Volume:
Findings of the Association for Computational Linguistics ACL 2024
Month:
August
Year:
2024
Address:
Bangkok, Thailand and virtual meeting
Editors:
Lun-Wei Ku, Andre Martins, Vivek Srikumar
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
2721–2733
Language:
URL:
https://aclanthology.org/2024.findings-acl.159
DOI:
10.18653/v1/2024.findings-acl.159
Bibkey:
Cite (ACL):
Sergio Servantez, Joe Barrow, Kristian Hammond, and Rajiv Jain. 2024. Chain of Logic: Rule-Based Reasoning with Large Language Models. In Findings of the Association for Computational Linguistics ACL 2024, pages 2721–2733, Bangkok, Thailand and virtual meeting. Association for Computational Linguistics.
Cite (Informal):
Chain of Logic: Rule-Based Reasoning with Large Language Models (Servantez et al., Findings 2024)
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PDF:
https://aclanthology.org/2024.findings-acl.159.pdf