LightThinker++: From Reasoning Compression to Memory Management

While LLMs excel at complex reasoning, long thought traces create surging cognitive overhead. LightThinker++ moves beyond static compression by introducing three explicit memory primitives: Commit (archive a step as a compact summary), Expand (retrieve past steps for verification), and Fold (collapse context to maintain a clean signal). The framework reduces peak token usage by 70% while gaining +2.42% accuracy on standard reasoning tasks, and maintains stability beyond 80 rounds on long-horizon agentic tasks with a 14.8% average performance improvement.