Improving Natural-Language Combinatorial-Optimization Accuracy in Resource-Constrained Language Models via Formal Abstractions

Shrenil Shaun Sharma, Avi Sharma


Abstract
Combinatorial scheduling poses a significant challenge for language models, requiring them to identify feasible solutions within exponentially large search spaces while satisfying complex constraints. This challenge is especially pronounced in resource-constrained settings, where larger language models are impractical and selection is limited to smaller models which often fail to preserve feasibility when scheduling directly from natural language. To address these limitations, we introduce SDDL, a neuro-symbolic framework that translates natural-language scheduling problems into compact, solver-aligned representations of tasks, resources, constraints, and objectives, while delegating low-level modeling and search to a deterministic compiler and external solver. On a 300-instance, multi-family subset of scheduling problems, SDDL improves independently verified feasibility for every resource-constrained model tested. The two strongest SDDL configurations reach 55.3% and 28.3%, up from direct-generation baselines of 23.7% and 1.3% and solver-code baselines of 21.7% and 7.0%, with a 0.0% median optimality gap among feasible schedules. By expressing problem structure rather than generating solutions or solver code, SDDL enables smaller models to approach the strongest evaluated direct- and solver-code configurations, including substantially larger frontier models.
Anthology ID:
2026.mathnlp-main.14
Volume:
The Proceedings of the 4th Workshop on Mathematical Natural Language Processing (MathNLP 2026)
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Marco Valentino, Deborah Ferreira, Mokanarangan Thayaparan, Leonardo Ranaldi, Jo-Ku Cheng, Andre Freitas
Venues:
MathNLP | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
177–193
Language:
URL:
https://aclanthology.org/2026.mathnlp-main.14/
DOI:
Bibkey:
Cite (ACL):
Shrenil Shaun Sharma and Avi Sharma. 2026. Improving Natural-Language Combinatorial-Optimization Accuracy in Resource-Constrained Language Models via Formal Abstractions. In The Proceedings of the 4th Workshop on Mathematical Natural Language Processing (MathNLP 2026), pages 177–193, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Improving Natural-Language Combinatorial-Optimization Accuracy in Resource-Constrained Language Models via Formal Abstractions (Sharma & Sharma, MathNLP 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.mathnlp-main.14.pdf