Yu Sato

[tfrs.tasks.Retrieval](https://www.tensorflow.org/recommenders/api_docs/python/tfrs/tasks/Retrieval) uses the [tf.keras.losses.CategoricalCrossentropy](https://www.tensorflow.org/api_docs/python/tf/keras/losses/CategoricalCrossentropy) loss function by default. I think that the number of classes in [tf.keras.losses.CategoricalCrossentropy](https://www.tensorflow.org/api_docs/python/tf/keras/losses/CategoricalCrossentropy) equals the batch size when we don't set the num_hard_negatives. Usually, the batch...