SOVER: Formal Certification of Optimization Reformulations via LLM-Assisted SMT Verification

Swapnil Bhattacharyya, Mayank Baranwal


Abstract
Large Language Models (LLMs) have shown remarkable promise in translating and reformulating complex mathematical optimization problems across modeling languages. However, validating such transformations through empirical solver executions alone is unreliable, as solver outcomes may be affected by local minima, structural timeouts, numerical artifacts, and subtle semantic divergence between formulations. We introduce SOVER, an LLM-assisted SMT framework that separates semantic mapping from formal certification: Z3 checks domain cross-feasibility and global objective order preservation for mixed-integer linear formulations, while dReal provides tolerance aware feasibility/range and ε-argmin checks for continuous nonlinear formulations. We also introduce NLEQUIV-150, a public benchmark of 100 equivalent and 50 deliberately hard non-equivalent nonlinear reformulation pairs. With LLM-extracted mappings, SOVER classifies 149/150 pairs (99.33%) correctly, including all 50 hard negatives; the sole error is an incomplete mapping extraction.
Anthology ID:
2026.findings-emnlp.1886
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
40213–40230
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.1886/
DOI:
10.18653/2026.findings-emnlp.1886
Bibkey:
Cite (ACL):
Swapnil Bhattacharyya and Mayank Baranwal. 2026. SOVER: Formal Certification of Optimization Reformulations via LLM-Assisted SMT Verification. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 40213–40230, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
SOVER: Formal Certification of Optimization Reformulations via LLM-Assisted SMT Verification (Bhattacharyya & Baranwal, Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.1886.pdf