“…In mathematics, the rank of a smooth function measures the volume of independent information captured by the function [21]. Deep neural networks are highly smooth functions, thus the rank of a network has long been an essential concept in machine learning that underlies many tasks such as information compression [48,56,36,54,49], network pruning [32,55,5,25,9], data mining [6,24,10,57,18,29], computer vision [59,58,31,27,29,60], and natural language processing [8,28,7,11]. Numerous methods are either designed to utilize the mathematical property of network ranks, or are derived from an assumption that low-rank structures are to be preferred.…”