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Co-authored-by: Lysandre Debut <lysandre.debut@reseau.eseo.fr>

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Co-authored-by: Lysandre Debut <lysandre.debut@reseau.eseo.fr>

docs/source/en/model_doc/bartpho.md

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+⚠️ Note that this file is in Markdown but contain specific syntax for our doc-builder (similar to MDX) that may not be
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+
+-->
+
+# BARTpho
+
+## Overview
+
+The BARTpho model was proposed in [BARTpho: Pre-trained Sequence-to-Sequence Models for Vietnamese](https://arxiv.org/abs/2109.09701) by Nguyen Luong Tran, Duong Minh Le and Dat Quoc Nguyen.
+
+The abstract from the paper is the following:
+
+*We present BARTpho with two versions -- BARTpho_word and BARTpho_syllable -- the first public large-scale monolingual
+sequence-to-sequence models pre-trained for Vietnamese. Our BARTpho uses the "large" architecture and pre-training
+scheme of the sequence-to-sequence denoising model BART, thus especially suitable for generative NLP tasks. Experiments
+on a downstream task of Vietnamese text summarization show that in both automatic and human evaluations, our BARTpho
+outperforms the strong baseline mBART and improves the state-of-the-art. We release BARTpho to facilitate future
+research and applications of generative Vietnamese NLP tasks.*
+
+Example of use:
+
+```python
+>>> import torch
+>>> from transformers import AutoModel, AutoTokenizer
+
+>>> bartpho = AutoModel.from_pretrained("vinai/bartpho-syllable")
+
+>>> tokenizer = AutoTokenizer.from_pretrained("vinai/bartpho-syllable")
+
+>>> line = "Chúng tôi là những nghiên cứu viên."
+
+>>> input_ids = tokenizer(line, return_tensors="pt")
+
+>>> with torch.no_grad():
+...     features = bartpho(**input_ids)  # Models outputs are now tuples
+
+>>> # With TensorFlow 2.0+:
+>>> from transformers import TFAutoModel
+
+>>> bartpho = TFAutoModel.from_pretrained("vinai/bartpho-syllable")
+>>> input_ids = tokenizer(line, return_tensors="tf")
+>>> features = bartpho(**input_ids)
+```
+
+Tips:
+
+- Following mBART, BARTpho uses the "large" architecture of BART with an additional layer-normalization layer on top of
+  both the encoder and decoder. Thus, usage examples in the [documentation of BART](bart), when adapting to use
+  with BARTpho, should be adjusted by replacing the BART-specialized classes with the mBART-specialized counterparts.
+  For example:
+
+```python
+>>> from transformers import MBartForConditionalGeneration
+
+>>> bartpho = MBartForConditionalGeneration.from_pretrained("vinai/bartpho-syllable")
+>>> TXT = "Chúng tôi là <mask> nghiên cứu viên."
+>>> input_ids = tokenizer([TXT], return_tensors="pt")["input_ids"]
+>>> logits = bartpho(input_ids).logits
+>>> masked_index = (input_ids[0] == tokenizer.mask_token_id).nonzero().item()
+>>> probs = logits[0, masked_index].softmax(dim=0)
+>>> values, predictions = probs.topk(5)
+>>> print(tokenizer.decode(predictions).split())
+```
+
+- This implementation is only for tokenization: "monolingual_vocab_file" consists of Vietnamese-specialized types
+  extracted from the pre-trained SentencePiece model "vocab_file" that is available from the multilingual XLM-RoBERTa.
+  Other languages, if employing this pre-trained multilingual SentencePiece model "vocab_file" for subword
+  segmentation, can reuse BartphoTokenizer with their own language-specialized "monolingual_vocab_file".
+
+This model was contributed by [dqnguyen](https://huggingface.co/dqnguyen). The original code can be found [here](https://github.com/VinAIResearch/BARTpho).
+
+## BartphoTokenizer
+
+[[autodoc]] BartphoTokenizer