Reasoning Language Models: A Blueprint
Authors: name: Maciej Besta, name: Julia Barth, name: Eric Schreiber, name: Ales Kubicek, name: Afonso Catarino, name: Robert Gerstenberger, name: Piotr Nyczyk, name: Patrick Iff, name: Yueling Li, name: Sam Houliston, name: Tomasz Sternal, name: Marcin Copik, name: Grzegorz Kwaśniewski, name: Jürgen Müller, name: Łukasz Flis, name: Hannes Eberhard, name: Hubert Niewiadomski, name: Torsten Hoefler

Reasoning language models (RLMs), also known as Large Reasoning Models
(LRMs), such as OpenAI's o1 and o3, DeepSeek-V3, and Alibaba's QwQ, have
redefined AI's problem-solving capabilities by extending large language models
(LLMs) with advanced reasoning mechanisms. Yet, their high costs, proprietary
nature, and complex architectures - uniquely combining Reinforcement Learning
(RL), search heuristics, and LLMs - present accessibility and scalability
challenges. To address these, we propose a comprehensive blueprint that
organizes RLM components into a modular framework, based on a survey and
analysis of all RLM works. This blueprint incorporates diverse reasoning
structures (chains, trees, graphs, and nested forms), reasoning strategies
(e.g., Monte Carlo Tree Search, Beam Search), RL concepts (policy, value models
and others), and supervision schemes (Output-Based and Process-Based
Supervision). We also provide detailed mathematical formulations and
algorithmic specifications to simplify RLM implementation. By showing how
schemes like LLaMA-Berry, QwQ, Journey Learning, and Graph of Thoughts fit as
special cases, we demonstrate the blueprint's versatility and unifying
potential. To illustrate its utility, we introduce x1, a modular implementation
for rapid RLM prototyping and experimentation. Using x1 and a literature
review, we provide key insights, such as multi-phase training for policy and
value models, and the importance of familiar training distributions. Finally,
we outline how RLMs can integrate with a broader LLM ecosystem, including tools
and databases. Our work demystifies RLM construction, democratizes advanced
reasoning capabilities, and fosters innovation, aiming to mitigate the gap
between "rich AI" and "poor AI" by lowering barriers to RLM development and
experimentation.