Saved in:
Bibliographic Details
Main Authors: Gao, Xinyu, Wang, Shaonan, Ding, Nai
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2602.15846
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917438220664832
author Gao, Xinyu
Wang, Shaonan
Ding, Nai
author_facet Gao, Xinyu
Wang, Shaonan
Ding, Nai
contents Decoder-only large language models achieve strong broad performance but are brittle to minor grammatical perturbations, undermining reliability for downstream reasoning. However, directly injecting explicit syntactic structure into an existing checkpoint can interfere with its pretrained competence. We introduce a checkpoint-compatible gated tree cross-attention (GTCA) branch that reads precomputed constituency chunk memory while leaving backbone architecture unchanged. Our design uses a token update mask and staged training to control the scope and timing of structural updates. Across benchmarks and Transformer backbones, GTCA strengthens syntactic robustness beyond continued-training baselines without compromising Multiple-Choice QA performance or commonsense reasoning, providing a practical checkpoint-compatible route to more syntax-robust decoder-only LLMs.
format Preprint
id arxiv_https___arxiv_org_abs_2602_15846
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Gated Tree Cross-Attention for Checkpoint-Compatible Syntax Injection in Decoder-Only LLMs
Gao, Xinyu
Wang, Shaonan
Ding, Nai
Computation and Language
Decoder-only large language models achieve strong broad performance but are brittle to minor grammatical perturbations, undermining reliability for downstream reasoning. However, directly injecting explicit syntactic structure into an existing checkpoint can interfere with its pretrained competence. We introduce a checkpoint-compatible gated tree cross-attention (GTCA) branch that reads precomputed constituency chunk memory while leaving backbone architecture unchanged. Our design uses a token update mask and staged training to control the scope and timing of structural updates. Across benchmarks and Transformer backbones, GTCA strengthens syntactic robustness beyond continued-training baselines without compromising Multiple-Choice QA performance or commonsense reasoning, providing a practical checkpoint-compatible route to more syntax-robust decoder-only LLMs.
title Gated Tree Cross-Attention for Checkpoint-Compatible Syntax Injection in Decoder-Only LLMs
topic Computation and Language
url https://arxiv.org/abs/2602.15846