SSR: Symbolic-Neural Soft Reasoning for Robust and Verifiable Thinking Chains

Rui Wang, Zeming Wei, Yihao Zhang, Xiaokun Luan


Abstract
Large Language Models (LLMs) have demonstrated impressive progress in complex reasoning tasks, largely driven by the Chain-of-Thought (CoT) paradigm, which decomposes difficult problems into intermediate steps. However, CoT reasoning remains fundamentally constrained by the probabilistic nature of neural generation, leading to unfaithful reasoning chains that undermine reliability. Neuro-symbolic approaches attempt to address these issues by combining LLMs with symbolic solvers, yet they face persistent challenges, including hallucinated translations, the mismatch between natural language and formal logic, and the limited enhancement of the LLM’s intrinsic reasoning ability. To overcome these limitations, we propose Symbolic-Neural Soft Reasoning (SSR), a unified framework that integrates LLMs with symbolic reasoning and improves robustness by relaxing strict logical determinism while preserving verifiability. Our approach improves reasoning performance, automatically generates verifiable and human-readable logical thinking chains for training and fine-tuning, and facilitates cross-disciplinary applications such as AI for mathematics. Experiments across multiple models and benchmarks demonstrate that SSR consistently outperforms existing reasoning frameworks, highlighting its effectiveness in enhancing both the robustness and interpretability of LLM reasoning. Our code is available at https://github.com/1240148048/SSR.
Anthology ID:
2026.emnlp-main.1241
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
28289–28308
Language:
URL:
https://aclanthology.org/2026.emnlp-main.1241/
DOI:
Bibkey:
Cite (ACL):
Rui Wang, Zeming Wei, Yihao Zhang, and Xiaokun Luan. 2026. SSR: Symbolic-Neural Soft Reasoning for Robust and Verifiable Thinking Chains. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 28289–28308, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
SSR: Symbolic-Neural Soft Reasoning for Robust and Verifiable Thinking Chains (Wang et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.1241.pdf