Foci cracks ARC puzzle 42 with delta-based cell features
Filed from the iterative solver · 2026-04-13
The iterative ARC solver has, for the first time, resolved puzzle 42 end-to-end — a long-standing thorn — after the introduction of delta-based cell-level features and a seq-to-seq hint stream riding atop the latest checkpoint. It is not yet general intelligence. It is, however, the sound of a lock turning.
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