Review for NeurIPS paper: Posterior Re-calibration for Imbalanced Datasets

Clarity: I found some parts are a bit difficult to follow and I have the following questions: 1. How to get P_t(y) in this paper? I think it is clearer to clarify the problem setting in Sec. Also how to get P_s(y)? I guess it is from counting the training data with its associated labels.