FIRMA: Bidirectional Formal-Informal Mathematical Language Alignment with Proof-Theoretic Grounding

Maryam Fatima


Abstract
While large language models excel at gener- ating plausible mathematical text, they often produce subtly incorrect formal translations that violate proof-theoretic constraints. We present FIRMA (Formal-Informal Reasoning in Mathematical Alignment), a bidirectional translation system between formal and informal mathematical language that leverages proof-theoretic interpretability hierarchies and specialized architectural components for proof preservation. Unlike existing approaches that treat this as pure sequence-to-sequence translation, FIRMA introduces a hierarchical architecture with complexity-aware routing, proof-preserving attention mechanisms, and multi-objective training that balances formal correctness with natural readability. Through progressive complexity training on curated datasets from Lean 4 and formal mathematics repositories, we evaluate FIRMA on 200 translation samples across complexity levels and compare against two baseline systems. Our analysis shows statistically significant improvements of 277.8% over BFS-Prover- V1-7B and 6307.5% over REAL-Prover on overall translation quality metrics. Ablation studies on 50 samples demonstrate that each architectural component contributes substan- tially to performance, with removal of any component resulting in 83-85% performance degradation. We release our code at https://github.com/smfatima3/FIRMA
Anthology ID:
2025.mathnlp-main.5
Volume:
Proceedings of The 3rd Workshop on Mathematical Natural Language Processing (MathNLP 2025)
Month:
November
Year:
2025
Address:
Suzhou, China
Editors:
Marco Valentino, Deborah Ferreira, Mokanarangan Thayaparan, Leonardo Ranaldi, Andre Freitas
Venues:
MathNLP | WS
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Publisher:
Association for Computational Linguistics
Note:
Pages:
62–76
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URL:
https://preview.aclanthology.org/ingest-emnlp/2025.mathnlp-main.5/
DOI:
Bibkey:
Cite (ACL):
Maryam Fatima. 2025. FIRMA: Bidirectional Formal-Informal Mathematical Language Alignment with Proof-Theoretic Grounding. In Proceedings of The 3rd Workshop on Mathematical Natural Language Processing (MathNLP 2025), pages 62–76, Suzhou, China. Association for Computational Linguistics.
Cite (Informal):
FIRMA: Bidirectional Formal-Informal Mathematical Language Alignment with Proof-Theoretic Grounding (Fatima, MathNLP 2025)
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PDF:
https://preview.aclanthology.org/ingest-emnlp/2025.mathnlp-main.5.pdf