Sets and negation in a logic database language (LDL1 (1987)

by C Beeri, S A Naqvi, R Ramakrishnan, O Shmueli, S Tsur
Venue:In Vardi, M. Y. (Ed.), Proceedings of the Sixth Zhou, Cuenca Grau, Nenov, Kaminski, & Horrocks ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems