dagger-4B_GRPO

DAGGER-4B-GRPO

<p align="center"> <a href="https://arxiv.org/abs/2601.06853"> <img src="https://img.shields.io/badge/%F0%9F%94%A5_Accepted_at-EMNLP_2026_(Findings)_%F0%9F%94%A5-b12a00?style=for-the-badge&labelColor=ffb300" alt="Accepted at EMNLP 2026 (Findings)"> </a> </p>

Model Description

DAGGER-4B-GRPO is trained with GRPO directly from the base Gemma-3-4B model without SFT initialization. This ablation model demonstrates the critical importance of SFT initialization for smaller models.

Model Overview

Performance

Critical Finding: SFT Initialization Effect

Key Insight: For 4B models, GRPO without SFT struggles to learn reliable graph generation. SFT provides essential scaffolding:

• +25.6 points on MGSM
• +18.3 points on MGSM (+Distractor)
• +13.6 points on MSVAMP (+Distractor)

This effect is more pronounced in smaller models than in 12B variants.

Quickstart

from transformers import AutoModelForCausalLM, AutoTokenizer

model_name = "dipta007/dagger-4B_GRPO"

tokenizer = AutoTokenizer.from_pretrained(model_name)
model = AutoModelForCausalLM.from_pretrained(
    model_name,
    torch_dtype="auto",
    device_map="auto"
)

USER_PROMPT_TEMPLATE = """You are an expert Bengali Math Reasoner. Your task is to solve mathematical problems by constructing a "Computational Graph".

### Graph Rules:
- `id`: Unique identifier (e.g., "n1", "n2").
- `val`: The raw number extracted from text (for input nodes).
- `op`: The operation (`add`, `sub`, `mul`, `div`, `round`, `sqrt`, `floor`, `sum`, `mean`). Use `const` for input numbers.
- `args`: List of input node IDs.
- `distractor`: Boolean (`true` / `false`). Set to `true` if the node is NOT used in the final calculation path.
- `label`: Label for the node.

### Available Operations:
- Input: `const` (Use this for all numbers found in text or constants).
- Arithmetic: `add`, `sub`, `mul`, `div`, `abs` (absolute difference).
- Logic/Stats: `sum`, `mean`, `min` (minimum), `max` (maximum).
- Rounding: `round` (nearest int), `floor` (round down), `ceil` (round up).
- Advanced: `sqrt`, `pow`, `mod` (remainder), `gcd`, `lcm`.
- Output: `identity` ("final_result" points to the answer node)

Only output a JSON graph representing the solution, nothing else. Nodes must be topologically sorted, and there must be exactly one "final_result" node that represents the final answer. One example is provided below.

### Example:
Question:
মিনার কাছে ১২২১৯৫ টা কলম আছে। রাজুর কাছে ২৫০৮৪ টা কলম আছে। মিনা রাজুর কাছে ১১২৬ টি কলম চাইল। রাজু ১০০০ টি কলম দিতে রাজি হল, কিন্তু পরে আর দিলেনা। প্রতিটি কলমের দাম ৪৫.৬ টাকা। মিনা যদি কলমগুলো বিক্রি করতে চায়, সে কত টাকা পাবে?

Output:
```json
{{
  "nodes": [
    {{"id": "n1", "op": "const", "val": 122195, "distractor": false, "label": "মিনার কলম"}},
    {{"id": "n2", "op": "const", "val": 25084, "distractor": true, "label": "রাজুর কলম"}},
    {{"id": "n3", "op": "const", "val": 1126, "distractor": true, "label": "মিনা রাজুর কাছে চাইল"}},
    {{"id": "n4", "op": "const", "val": 1000, "distractor": true, "label": "রাজু দিতে রাজি হল"}},
    {{"id": "n5", "op": "const", "val": 45.6, "distractor": false, "label": "প্রতিটি কলমের দাম"}},
    {{"id": "total_money", "op": "mul", "args": ["n1", "n5"], "distractor": false, "label": "মিনার মোট টাকা"}},
    {{"id": "final_result", "op": "identity", "args": ["total_money"], "distractor": false, "label": "চূড়ান্ত উত্তর"}}
  ]
}}```

### Your Task:

Question:
{question}

Output:
"""

question = "রজারের 5টি টেনিস বল আছে। সে আরও 2 ক্যান টেনিস বল কিনেছে। প্রতিটি ক্যানে 3টি করে টেনিস বল আছে। তার কাছে এখন কতগুলি টেনিস বল আছে?"
prompt = USER_PROMPT_TEMPLATE.format(question=question)

messages = [
  {"role": "user", "content": prompt}
]

text = tokenizer.apply_chat_template(messages, tokenize=False, add_generation_prompt=True)
inputs = tokenizer(text, return_tensors="pt").to(model.device)

# Generate
outputs = model.generate(**inputs, max_new_tokens=1024, temperature=0.7, top_p=0.8)
response = tokenizer.decode(outputs[0][len(inputs.input_ids[0]):], skip_special_tokens=True)

print(response)

Training Configuration

When to Use This Model

• Ablation studies: Understanding SFT contribution for smaller models
• Research: Studying capacity requirements for GRPO-only training
• NOT recommended for production: Use dagger-4B_SFT_GRPO instead

Limitations

• Low accuracy: Struggles to generate valid computational graphs
• High failure rate: Often produces malformed JSON or incorrect structures
• Poor distractor handling: Collapses to 13.1% on augmented MGSM

Recommendation

For 4B models, always use SFT initialization before GRPO:

• dagger-4B_SFT_GRPO provides +18 points improvement

Related Models

License and Data Provenance

Model weights are released under the Gemma Terms of Use.

Training data is not fully permissive. Part of the SFT data and all GRPO prompts come from numina-math-cot-bn, which is CC BY-NC-SA 4.0 (NonCommercial, ShareAlike). For commercial use, re-derive that portion from the Apache-2.0 upstream AI-MO/NuminaMath-CoT.

Citation

@inproceedings{nazi2026dagger,
  title={{\dag}DAGGER: Distractor-Aware Graph Generation for Executable Reasoning in Math Problems},
  author={Zabir Al Nazi and Shubhashis Roy Dipta and Sudipta Kar},
  booktitle={Findings of the Association for Computational Linguistics: EMNLP 2026},
  year={2026},
  eprint={2601.06853},
  archivePrefix={arXiv},
  primaryClass={cs.CL},
  url={https://arxiv.org/abs/2601.06853},
}