UFAL-CUNI at SemEval-2026 Task 11: An Efficient Modular Neuro-symbolic Method for Syllogistic Reasoning

Ivan Kartac, Kristyna Onderkova, Jan Bronec, Zdeněk Kasner, Mateusz Lango, Ondrej Dusek


Abstract
This paper describes our system submitted to SemEval-2026 Task 11: Disentangling Content and Formal Reasoning in Large Language Models. We present an efficient modular neuro-symbolic approach, combining a symbolic prover with small reasoning LLMs (4B parameters). The system consists of an LLM-based parser that translates natural language syllogisms to a first-order logic (FOL) representation, an automated theorem prover, and two optional modules: machine translation for multilingual inputs and a symbolic retrieval component for the identification of relevant premises. The system achieves competitive accuracy and relatively low content effect on most subtasks. Our ablations show that this approach outperforms LLM-based zero-shot baselines in this parameter size range, but also reveal limited multilingual capabilities of small LLMs. Finally, we include a discussion of the task’s main ranking metric and analyze its limitations.
Anthology ID:
2026.semeval-1.418
Volume:
Proceedings of the 20th International Workshop on Semantic Evaluation (2026)
Month:
July
Year:
2026
Address:
San Diego, California, USA
Editors:
Ekaterina Kochmar, Debanjan Ghosh, Kai North, Mamoru Komachi
Venues:
SemEval | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
3363–3376
Language:
URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.418/
DOI:
Bibkey:
Cite (ACL):
Ivan Kartac, Kristyna Onderkova, Jan Bronec, Zdeněk Kasner, Mateusz Lango, and Ondrej Dusek. 2026. UFAL-CUNI at SemEval-2026 Task 11: An Efficient Modular Neuro-symbolic Method for Syllogistic Reasoning. In Proceedings of the 20th International Workshop on Semantic Evaluation (2026), pages 3363–3376, San Diego, California, USA. Association for Computational Linguistics.
Cite (Informal):
UFAL-CUNI at SemEval-2026 Task 11: An Efficient Modular Neuro-symbolic Method for Syllogistic Reasoning (Kartac et al., SemEval 2026)
Copy Citation:
PDF:
https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.418.pdf