Accurate Legal Reasoning at Scale: Neuro-Symbolic Offloading and Structural Auditability for Robust Legal Adjudication
Paper · 2026 · Stanisław Sójka and Witold Kowalczyk
Summary
Large reasoning models (LRMs) can explain contract or statutory provisions that involve formulas, thresholds and dates. Using them to decide every individual transaction, however, is expensive and unreliable. Arithmetic slips, dropped conditions and different answers to identical inputs are unacceptable in billing or legal decisions. The authors (Delos AI) propose Amortized Intelligence. An LLM runs once, as a compiler, to convert a contract into DACL (Deterministic Autonomous Contract Language), a typed graph representation built from a small set of clause primitives. Each later event is resolved by executing this graph deterministically. A lightweight orchestrator (gpt-5-mini) only selects the relevant clauses and phrases the answer, and every decision comes with an inspectable execution trace. The authors tested the system on four proprietary industrial agreements against GPT-5.2, Claude 4.5 Sonnet and Gemini 3 Pro with reasoning enabled. The DACL Agent reaches about 99.5% accuracy, avoids the accuracy collapse LRMs show on complex clauses, and runs far cheaper and faster. This matters for high-volume, audit-sensitive automation where a human cannot review every output.
Key points
- DACL represents contract logic as a DAG with four recursive primitives: Procedure, Logical Clause, Range Clause and Pricing Formula. Clause-level validity dates let amendments be recompiled locally.
- The runtime agent is built on the OpenAI Agents SDK and has a single tool (
evaluate_clauses_tool) that calls the deterministic engine. - On efficiency, the DACL Agent used 1.35M tokens versus 13.44M for GPT-5.2 Medium (9.9x fewer). On Logistics-MSA it took about 26.8 s per event versus roughly 164 s for the reasoning baselines. The paper reports cost savings of over 90% in the abstract and over 95% for high-volume tasks in its contributions list. GPT-5.2 without reasoning reached only 58% accuracy.
- The system has been in production for more than 12 months, handling billing and accounts payable for 150+ agreements and about 1,000 billing events per month.
- The authors note several limitations:
- The primitives do not cover defeasible reasoning or open-textured standards.
- The evaluation uses synthetic traffic and English contracts only.
- Any compile-time misreading of a clause is repeated deterministically until it is fixed.
Fields, topics and concepts
📚 Shelves 4The field of science this work belongs to (OpenAlex fields).Computer Science · 16,667 worksArtificial Intelligence · 16,194 worksSocial Sciences · 1,772 worksPolitical Science and International Relations · 182 works
🧭 Topics 2Research subjects and languages the work is about.Reasoning · 1,426 worksLegal AI · 134 works
Cite
Cite as Stanisław Sójka and Witold Kowalczyk. 2026. Accurate Legal Reasoning at Scale: Neuro-Symbolic Offloading and Structural Auditability for Robust Legal Adjudication. Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 6: Industry Track).
@inproceedings{sojka2026accurate,
title = {{Accurate Legal Reasoning at Scale: Neuro-Symbolic Offloading and Structural Auditability for Robust Legal Adjudication}},
author = {Stanisław Sójka and Witold Kowalczyk},
booktitle = {Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 6: Industry Track)},
year = {2026},
doi = {10.18653/v1/2026.acl-industry.102},
url = {https://doi.org/10.18653/v1/2026.acl-industry.102}
}References
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