Quasi-symbolic Semantic Geometry over Transformer-based Variational AutoEncoder

Yingji Zhang, Danilo Carvalho, Andre Freitas


Abstract
Formal/symbolic semantics can provide canonical, rigid controllability and interpretability to sentence representations due to their localisation or composition property. How can we deliver such property to the current distributional sentence representations to better control and interpret the generation of language models (LMs)? In this work, we theoretically frame the sentence semantics as the composition of semantic role - word content features and propose the formal semantic geometrical framework. To inject such geometry into Transformer-based LMs (i.e. GPT2), we deploy a supervised Transformer-based Variational AutoEncoder, where the sentence generation can be manipulated and explained over low-dimensional latent Gaussian space. In addition, we propose a new probing algorithm to guide the movement of sentence vectors over such geometry. Experimental results reveal that the formal semantic geometry can potentially deliver better control and interpretation to sentence generation.
Anthology ID:
2025.conll-1.2
Volume:
Proceedings of the 29th Conference on Computational Natural Language Learning
Month:
July
Year:
2025
Address:
Vienna, Austria
Editors:
Gemma Boleda, Michael Roth
Venues:
CoNLL | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
12–29
Language:
URL:
https://preview.aclanthology.org/acl25-workshop-ingestion/2025.conll-1.2/
DOI:
Bibkey:
Cite (ACL):
Yingji Zhang, Danilo Carvalho, and Andre Freitas. 2025. Quasi-symbolic Semantic Geometry over Transformer-based Variational AutoEncoder. In Proceedings of the 29th Conference on Computational Natural Language Learning, pages 12–29, Vienna, Austria. Association for Computational Linguistics.
Cite (Informal):
Quasi-symbolic Semantic Geometry over Transformer-based Variational AutoEncoder (Zhang et al., CoNLL 2025)
Copy Citation:
PDF:
https://preview.aclanthology.org/acl25-workshop-ingestion/2025.conll-1.2.pdf