collaborators

9 papers

cs.LG2026

Beyond Linear Attention: Softmax Transformers Implement In-Context Reinforcement Learning

Zixuan Xie, Xinyu Liu, Claire Chen +3

In-context reinforcement learning (ICRL) studies agents that, after pretraining, adapt to new tasks by conditioning on additional context without parameter updates. Existing theore…

cs.LO2026

MathlibPR: Pull Request Merge-Readiness Benchmark for Formal Mathematical Libraries

Zixuan Xie, Xinyu Liu, Shangtong Zhang

The ecosystem of Lean and Mathlib has become the de facto standard for large language model (LLM) assisted formal reasoning with remarkable successes in recent years. Those success…

cs.LG2026

Convergence and Emergence of In-Context Reinforcement Learning with Chain of Thought

Zixuan Xie, Xinyu Liu, Rohan Chandra +1

In-context reinforcement learning (ICRL) refers to the ability of RL agents to adapt to new tasks at inference time without parameter updates by conditioning on additional context.…

cs.LG2026

Almost Sure Convergence Rates of Stochastic Approximation and Reinforcement Learning via a Poisson-Moreau Drift

Xinyu Liu, Zixuan Xie, Shangtong Zhang

Establishing almost sure convergence rates for stochastic approximation and reinforcement learning under Markovian noise is a fundamental theoretical challenge. We make progress to…

cs.LG2026

On the Divergence of Differential Temporal Difference Learning without Local Clocks

David Antrobius, Shangtong Zhang

Learning rate is a critical component of reinforcement learning (RL). This work uses global and local clocks to distinguish two types of learning rates. The former is of the standa…

cs.LO2026

MathlibLemma: Folklore Lemma Generation and Benchmark for Formal Mathematics

Xinyu Liu, Zixuan Xie, Amir Moeini +5

While the ecosystem of Lean and Mathlib has enjoyed celebrated success in formal mathematical reasoning with the help of large language models (LLMs), the absence of many folklore…

cs.LG2025

Extensions of Robbins-Siegmund Theorem with Applications in Reinforcement Learning

Xinyu Liu, Zixuan Xie, Shangtong Zhang

The Robbins-Siegmund theorem establishes the convergence of stochastic processes that are almost supermartingales and is one of the most commonly used approaches for analyzing stoc…

cs.LG2025

Finite Sample Analysis of Linear Temporal Difference Learning with Arbitrary Features

Zixuan Xie, Xinyu Liu, Rohan Chandra +1

Linear TD() is one of the most fundamental reinforcement learning algorithms for policy evaluation. Previously, convergence rates are typically established under the assumption…

cs.LG2025

Linear -Learning Does Not Diverge in : Convergence Rates to a Bounded Set

Xinyu Liu, Zixuan Xie, Shangtong Zhang

-learning is one of the most fundamental reinforcement learning algorithms. It is widely believed that -learning with linear function approximation (i.e., linear -learning…