@article {2010.10503, archivePrefix = {arXiv}, eprint = {2010.10503}, primaryClass = {cs.PL}, author = {Matthew Francis-Landau and Tim Vieira and Jason Eisner}, title = {Evaluation of Logic Programs with Built-Ins and Aggregation: A Calculus for Bag Relations}, year = {2020}, url = {http://arxiv.org/abs/2010.10503} }