---
title: MR-9B Scaffold — 0/7 Trajectories
emoji: 🔬
colorFrom: red
colorTo: indigo
sdk: static
app_file: index.html
pinned: false
license: mit
short_description: How MR-9B explores SODA-2026 problems 0-step FA can't solve
---

# MR-9B RL scaffold on the FA-0-zero SODA-2026 problems

A static trace viewer for the **44 SODA-2026 `standalone_hard` (proof_writing)**
problems that the RL policy `meta-learning-llms/MR_9B_rl_215_step45` scored **0/7 on
all 8 samples** with a **0-step final answer** — after excluding 9 rows with broken
(`Total: 0`) rubrics that score 0 by construction.

Each trajectory is the **full 8-layer MR/E/FA scaffold** (MR/FA = the RL policy,
E = frozen `MR_midtrain_9B_v3`). It shows, in order:

1. the **problem** + its **ground-truth rubric + reference solution**,
2. the **final answer**, its **judge score** (gpt-oss-120b), and the **judge's
   reasoning** for that score,
3. then the **MR/E exploration** — per-layer directions, planner CoT, assembled
   frontier, and each executed direction's finding + summary.

With one attempt the scaffold rescues **13/44** of these (vs 0/8 for FA-0).