arXiv AI
1d ago

Implicit Reasoning in Transformers: Bridging the Compositionality Gap in GPT-2-like Models

The paper examines the compositionality gap in GPT‑2‑like transformers, where models can combine known facts in‑distribution but fail to generalize to out‑of‑distribution knowledge. By aligning the training distribution so that both ID and OOD atomic facts appear in the same positional format as the second‑hop retrieval step of a known compositional circuit, the authors show that the model can transfer its learned compositional behavior to unseen OOD facts. This demonstrates that the gap is not an inherent architectural limitation but can be addressed through targeted training distribution design.

By Davide Venuto, Leonardo Venuto
arXiv Computation and Language
Aug 28

Why Knowing Both Hops Is Not Enough: Understanding Two-Hop Generalization in Language Models

Large language models can solve complex multi‑hop tasks but often fail on simple two‑hop queries, even when each hop is individually correct. In a controlled symbolic setting, the authors find that models generalize reliably when the second hop follows the training distribution, but always fail when it deviates. Mechanistic analysis shows that successful generalization relies on consistent intermediate representations across contexts, whereas failures arise from a mismatch between lower‑layer representation construction and upper‑layer mapping to outputs. The study proposes a recurrent‑style training strategy that improves out‑of‑distribution two‑hop generalization.

By Zili Zhang, Yilin Wang, Heng Wang, Herun Wan, Minnan Luo
arXiv AI
Sep 1

Learning Composable Chains-of-Thought

arXiv:2505.22635v2 Announce Type: replace-cross Abstract: A common approach for teaching large language models (LLMs) to reason is to train on chain-of-thought (CoT) traces of in-distribution reasoni...

By Fangcong Yin, Zeyu Leo Liu, Liu Leqi, Xi Ye, Greg Durrett