Schema Harness Achieves ~99% on Arc‑AGI‑3 Public
Summary
Schema harness from Impossible Research reports ~99% RHAE on ARC-AGI-3 Public using Claude Opus 4.8 and Fable 5, with 95.35% on GPT-5.6 Sol. The system treats the world model as an executable program, jointly grounding state and deriving transition rules, and uses a four-stage loop (observe, deliberate, execute, record) with an append-only Timeline. Results are self-reported; independent verification pending. The article includes case studies and comparisons between model variants.