# Neuro-symbolic Syntactic Parsing: Shaping a Neural Network with the CYK Algorithm

arXiv: https://arxiv.org/abs/2605.31421 · HTML: https://mlsanity.com/paper/2605.31421/

## Key facts

- No citing papers in the map yet (data through 14 Oct 2026).
- Builds on 10 of its 28 references that are in the map.
- First posted on arXiv 29 May 2026.

## Builds on (most cited first, 10 of 10)

- [Attention Is All You Need](https://mlsanity.com/paper/1706.03762/) (2017)
- [Progress measures for grokking via mechanistic interpretability](https://mlsanity.com/paper/2301.05217/) (2023)
- [Grokking: Generalization Beyond Overfitting on Small Algorithmic Datasets](https://mlsanity.com/paper/2201.02177/) (2022)
- [GSM-Symbolic: Understanding the Limitations of Mathematical Reasoning in Large Language Models](https://mlsanity.com/paper/2410.05229/) (2024)
- [The Illusion of Thinking: Understanding the Strengths and Limitations of Reasoning Models via the Lens of Problem Complexity](https://mlsanity.com/paper/2506.06941/) (2025)
- [Unified View of Grokking, Double Descent and Emergent Abilities: A Perspective from Circuits Competition](https://mlsanity.com/paper/2402.15175/) (2024)
- [Understanding Grokking Through A Robustness Viewpoint](https://mlsanity.com/paper/2311.06597/) (2023)
- [Grokking in LLM Pretraining? Monitor Memorization-to-Generalization without Test](https://mlsanity.com/paper/2506.21551/) (2025)
- [MeMo: Towards Language Models with Associative Memory Mechanisms](https://mlsanity.com/paper/2502.12851/) (2025)
- [Parsing with CYK over Distributed Representations](https://mlsanity.com/paper/1705.08843/) (2017)

## Abstract (arXiv)

In this paper, we show the possibility of a direct injection of algorithms into neural network architecture. We focus on a complex algorithm, that is, Cocke-Youger-Kasami (CYK) for parsing context-free grammars in Chomsky Normal Form and we propose CYKNN, a simple recurrent neural network architecture for encoding the CYK algorithm in trainable matrix-vector multiplications.We experimented with a very simple grammar with 4 variations showing that our approach outperforms existing LLMs with more than 20B parameters with an in-context learning setting and smaller LLMs of the Qwen family fine-tuned with LoRA. Our attempt paves the way to a different approach to neuro-symbolic methodologies.