@article {659, title = {Relational Modeling and Reasoning with Multisets and Multirelations in Alloy}, number = {GSDLAB-TR 2016-01-22}, year = {2016}, abstract = {Multisets and multirelations arise naturally in modeling. In contrast, while ordinary sets and relations are first-class citizens in the Alloy environment, Alloy does not provide a direct way to work with multisets and multirelations. In this report, we present a sound and practical mathematical framework which encodes multisets and multirelations using only ordinary sets and total functions. We implement the encoding as a mutliconcepts library in Alloy which is declarative, compatible with ordinary sets and relations, and can be incorporated into existing models seamlessly.}, attachments = {http://gsd.uwaterloo.ca/sites/default/files/TR.pdf , http://gsd.uwaterloo.ca/sites/default/files/multi.als , http://gsd.uwaterloo.ca/sites/default/files/mset.als , http://gsd.uwaterloo.ca/sites/default/files/mrel.als , http://gsd.uwaterloo.ca/sites/default/files/Bundling model and visulization.zip , http://gsd.uwaterloo.ca/sites/default/files/test-suite.zip}, author = {Sun, Peiyuan and Diskin, Zinovy and Micha{\l} Antkiewicz and Krzysztof Czarnecki} }