README.md

0-layer transformer described in [A Mathematical Framework for Transformer Circuits](https://transformer-circuits.pub/2021/framework/index.html).
Load with
```python
class ZeroLayerTransformer(PreTrainedModel):
    config_class = LlamaConfig
    
    def __init__(self, config: LlamaConfig):
        super().__init__(config)
        self.embed_tokens = nn.Embedding(config.vocab_size, config.hidden_size)
        self.lm_head = nn.Linear(config.hidden_size, config.vocab_size, bias=False)

    def forward(self, input_ids=None, attention_mask=None, labels=None, **kwargs):
        hidden_states = self.embed_tokens(input_ids)
        logits = self.lm_head(hidden_states)

        loss = None
        if labels is not None:
            shift_logits = logits[..., :-1, :].contiguous()
            shift_labels = labels[..., 1:].contiguous()
            loss_fct = nn.CrossEntropyLoss()
            loss = loss_fct(
                shift_logits.view(-1, shift_logits.size(-1)), shift_labels.view(-1)
            )

        return {"loss": loss, "logits": logits}



model = ZeroLayerTransformer.from_pretrained('Butanium/simple-stories-zero-layer-simple-transformer')
```
The model is trained on the SimpleStories dataset.