Marco Console, Paolo Guagliardo, Leonid Libkin. Fragments of Bag Relational Algebra: Expressiveness and Certain Answers. In Pablo Barceló, Marco Calautti, editors, 22nd International Conference on Database Theory, ICDT 2019, March 26-28, 2019, Lisbon, Portugal. Volume 127 of LIPIcs, Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2019. [doi]
Abstract is missing.