Prior Work Deep-Dive · self-reported numbers · 2026‑07

schema (Impossible Research) — the certify-then-BFS loop, dissected

A system published 2026‑07 by Impossible Research + UC Berkeley + CMU. Every number on this page is a self-reported value they wrote on their own public page, and the loop signatures are verbatim copies of the schema-level descriptions they published — nothing here was reproduced by us or checked against their code.

01

Honesty notice — how to read these numbers

self‑reported Public set only (25 games) not verified by ARC Prize code not released

Both RHAE(%) figures below are their own self-reports on the Public set (25 games only), not independently verified by ARC Prize. The code itself is unreleased; the only artifact is the HF dataset schema-harness/arc-agi-3-schema-traces — so even the function signatures this page describes come verbatim from the schema-level explanations on their public page, not from source code.

98.98%RHAE · Opus 4.8 + Fable5 fallback
95.35%RHAE · GPT‑5.6 Sol xhigh&max
42.83%same model · stock Claude Code harness
+56.15ppcontrolled contrast (98.98−42.83)

The Fable 5 fallback rule: only games scoring under 80 were re-run with Fable 5 — so 98.98% is not a single-model single-shot score but the output of an ensemble pipeline that “retries weak games with a different model” (honesty notice).

The five-layer contrast — read the table first

layerours (TTSO)schema
① verificationpartial-credit credence (F1 scoring)exact full-history replay certification (run_backtest)
② body of knowledgerecord shards (mechanic/wincond/strategy/metathinking)one program revised in place (step)
③ state representationraw grid coordinates, fixedinvented representations · a counterexample can indict the representation itself
④ actingLLM eyeballing every round (THINK→HYPOTHESIS)certified BFS queue (run_bfs→commit_actions)
⑤ continuitybriefing reassembly (wake.py render() every round)notes.md + persistent plan (durable files)

Click any node in the §02 pipeline below and the matching row of this table unfolds next to its code schema.

02

The loop — click a node to pin the right panel

The outer four stages are observe → deliberate → execute → record. Inside deliberate, three steps split out — theorize → certify → plan — and those three are the heart of “certify-then-BFS.”

record ↻ observe Persistent memory = “the agent’s weights” = world_model.py + notes.md — it never carries to the next game; it lives only inside this one.
hover = preview · click = pin the panel · #anchor deep links.
03

LS20 measured — a mini case

One case, LS20, from their published per-game measurements. They state the discriminating-experiment principle — “commit the action for which the candidate rules predict different outcomes” — applied here too.

c0000 LS20 — world_model_v5

642actions (schema)
780actions (human)
100RHAE
36/36transitions exactly replayed (world_model_v5)

36/36 is a measured instance of “certify passed” — their stated figure meaning world_model_v5 exactly replayed all 36 recorded transitions under run_backtest.

GO

Direction of synthesis

if a certify gate sat in front of our fold

Their certify (run_backtest — a binary certification that passes only if every recorded transition replays exactly from scratch) is stricter than our code-fold’s (α,β) updates, but unforgiving. Our credence, conversely, is partial-credit — forgiving, but with no totality guarantee. The synthesis is to insert one certify-style gate right before promotion: before a skill crosses from park into the store, re-check in full that its predict_next replays every round recorded so far, and only then confirm the credence update. On top of that, what is distinctly ours stays — the cross-game transfer library, Bayesian credence, the leak-free audited constitution — because their memory dies with the game (world_model.py + notes.md live only inside it), while ours carrying over to the next game is the point of departure in the first place.