Hierarchical Bracketing Encodings Work for Dependency Graphs

Ana Ezquerro, Carlos Gómez-Rodríguez, David Vilares


Abstract
We revisit hierarchical bracketing encodings from a practical perspective in the context of dependency graph parsing. The approach encodes graphs as sequences, enabling linear-time parsing with n tagging actions, and still representing reentrancies, cycles, and empty nodes. Compared to existing graph linearizations, this representation substantially reduces the label space while preserving structural information. We evaluate it on a multilingual and multi-formalism benchmark, showing competitive results and consistent improvements over other methods in exact match accuracy.
Anthology ID:
2025.emnlp-main.447
Volume:
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Month:
November
Year:
2025
Address:
Suzhou, China
Editors:
Christos Christodoulopoulos, Tanmoy Chakraborty, Carolyn Rose, Violet Peng
Venue:
EMNLP
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Publisher:
Association for Computational Linguistics
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Pages:
8849–8862
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URL:
https://preview.aclanthology.org/ingest-emnlp/2025.emnlp-main.447/
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Bibkey:
Cite (ACL):
Ana Ezquerro, Carlos Gómez-Rodríguez, and David Vilares. 2025. Hierarchical Bracketing Encodings Work for Dependency Graphs. In Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing, pages 8849–8862, Suzhou, China. Association for Computational Linguistics.
Cite (Informal):
Hierarchical Bracketing Encodings Work for Dependency Graphs (Ezquerro et al., EMNLP 2025)
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