SnurfyAI/is-even

Is Even

Is Even is a tiny decoder-only transformer trained on chat-formatted synthetic data from SnurfyAI that predicts whether a decimal input is even.

This repository contains the published model weights and metadata for the released checkpoint.

What The Model Does

• Input: a decimal numeral rendered inside a fixed ChatML prompt
• Output: true for even numbers and false for odd numbers
• Tokenization: strict digit-level tokenization with a tiny fixed vocabulary

The task is mathematically determined by the final decimal digit, but the model was trained as a small transformer classifier on synthetic examples.

Prompt Format

<|im_start|>user
123456<|im_end|>
<|im_start|>assistant

The expected completion label is true or false.

Training Code

You can train the model yourself using the official SnurfyAI training codebase:

• SnurfyAI Is Even Core

The repository contains the code needed to generate the dataset, train the model, and benchmark saved checkpoints.

Research Paper

• A Microscopic Study of Decimal Parity in a Tiny Causal Transformer

The accompanying paper analyzes the model’s generalization behavior, attention structure, and causal dependence on the final digit.