---
base_model: Qwen/Qwen2.5-1.5B-Instruct
library_name: transformers
pipeline_tag: text-generation
tags:
- paper-model
- recursive-reasoning
- sat
- qwen2.5
- transformers
datasets:
- LLM4Code/SATBench
license: mit
---

# recursive-sat-qwen2.5-1.5b

This is a paper model: the `REC-3` release artifact from a paper-aligned replication of recursive SAT reasoning at 1.5B scale.

It is a supervised fine-tune of `Qwen/Qwen2.5-1.5B-Instruct` trained on recursive SAT traces derived from SATBench with explicit `<call>` / `<return>` structure. The goal is research replication and analysis, not general-purpose production use.

## What This Model Is

- Base model: `Qwen/Qwen2.5-1.5B-Instruct`
- Release artifact: `results/runs/REC-3/published_model`
- Training run: `REC-3`
- Seed: `303`
- Config: `configs/rec_seed303.yaml`
- Dataset source: `LLM4Code/SATBench`
- Task: SAT / UNSAT classification via recursive trace supervision

## Why REC-3

`REC-1` and `REC-3` tie on mean accuracy, but `REC-3` is the cleaner release candidate on end-to-end behavior:

- Mean accuracy: `45.33%`
- Easy: `39.0%`
- Medium: `54.0%`
- Hard: `43.0%`
- Parse failure rate: `7.0%`
- Valid trace rate: `99.0%`

Compared with `REC-1`, `REC-3` keeps the same mean accuracy while reducing parse failure (`7.0%` vs `8.33%`), improving hard accuracy (`43.0%` vs `42.0%`), and slightly improving valid trace rate (`99.0%` vs `98.33%`).

## Important Caveat

This is a paper model, not a claim of robust general recursive reasoning.

The underlying paper draft treats the result as a qualified replication:

- recursive SFT improves end-to-end SATBench accuracy over raw direct prompting
- the strongest gain is on medium-difficulty SAT instances
- absolute performance remains far below the 3B source-paper result
- recursion behavior is still shallow overall

Use this release as a research artifact tied to the experiment, metrics, and discussion in the paper repo.

## Training Summary

- Objective: `recursive_sft`
- Train examples: `74,827`
- Validation examples: `619`
- Global step: `46,770`
- Best checkpoint: `checkpoint-9354`
- Accelerator used for the main run: `cuda`

## Evaluation Summary

Main held-out evaluation uses `100` examples each from SATBench easy, medium, and hard buckets.

Baseline vs released model:

- Base direct prompt mean accuracy: `37.33%`
- `REC-3` mean accuracy: `45.33%`
- Absolute gain: `+8.0 points`
- Base parse failure rate: `28.67%`
- `REC-3` parse failure rate: `7.0%`

## Prompt Format

The model was trained on recursive traces using:

- `<call> ... </call>` for subproblem decomposition
- `<return> ... </return>` for compact returned answers

It is best treated as a specialized research model for this protocolized SAT setting.

## Files In This Release

- `model.safetensors`
- `config.json`
- `generation_config.json`
- `tokenizer.json`
- `tokenizer_config.json`
- `chat_template.jinja`
- `export_metadata.json`

## Intended Use

- paper artifact release
- replication reference
- SAT recursive-trace evaluation
- qualitative inspection of recursive protocol behavior

## Out Of Scope

- production reasoning system
- general mathematical reasoning benchmark model
- safety-critical use
- claims beyond the SATBench replication setting