activity
20242026
collaborators

7 papers

cs.CL2026

AbstRAG: Learning to Abstract for Retrieval Problems

Lei Xu, Xin Quan, Daniel Pedronette +1

Retrieval-augmented generation often fails when the query, the document evidence, and the user's intent are expressed at different levels of abstraction. A query may ask about a cl…

cs.CL2026

Reasoning without Gold Standards: A Proxy-Judge Theory of Autoformalization

Lei Xu, Xin Quan, André Freitas

Complex reasoning tasks increasingly require systems to produce outputs whose correctness cannot be judged by exact match against a single reference. Autoformalization (AF) is a re…

cs.CL2026

Metacognition as Reward: Reinforcing LLM Reasoning via Knowledge and Regulation Signals

Sirui Chen, Lei Xu, Yuying Zhao +6

Recent RL methods have substantially improved the reasoning abilities of LLMs. Existing reward designs mainly follow two paradigms: (1) Reinforcement learning with verifiable rewar…

cs.CL2026

CauScientist: Teaching LLMs to Respect Data for Causal Discovery

Bo Peng, Sirui Chen, Lei Xu +1

Causal discovery is fundamental to scientific understanding and reliable decision-making. Existing approaches face critical limitations: purely data-driven methods suffer from stat…

cs.CL2025

DEPO: Dual-Efficiency Preference Optimization for LLM Agents

Sirui Chen, Mengshi Zhao, Lei Xu +5

Recent advances in large language models (LLMs) have greatly improved their reasoning and decision-making abilities when deployed as agents. Richer reasoning, however, often comes…

cs.CL2025

Synthesis by Design: Controlled Data Generation via Structural Guidance

Lei Xu, Sirui Chen, Yuxuan Huang +1

Mathematical reasoning remains challenging for LLMs due to complex logic and the need for precise computation. Existing methods enhance LLM reasoning by synthesizing datasets throu…