Rui Zhang 0121 Rui Xin 0002 Margo I. Seltzer Cynthia Rudin Optimal Sparse Regression Trees. 2022 abs/2211.14980 CoRR https://doi.org/10.48550/arXiv.2211.14980 db/journals/corr/corr2211.html#abs-2211-14980