^Antoniadis, Tony; Triantafyllou, Konstantinos; Smaragdakis, Yannis (2017-06-18). "Porting doop to Soufflé". Proceedings of the 6th ACM SIGPLAN International Workshop on State of the Art in Program Analysis. SOAP 2017. New York, NY, USA: Association for Computing Machinery. pp. 25–30. doi:10.1145/3088515.3088522. ISBN978-1-4503-5072-3. S2CID3074689.
^"6.4. Negation - LogicBlox 3.10 Reference Manual". developer.logicblox.com. Retrieved 2023-03-04.
"Additionally, negation is only allowed when the platform can determine a way to stratify all rules and constraints that use negation."
^Zook, David; Pasalic, Emir; Sarna-Starosta, Beata (2009). Gill, Andy; Swift, Terrance (eds.). Typed Datalog. Practical Aspects of Declarative Languages. Lecture Notes in Computer Science. Vol. 5418. Berlin, Heidelberg: Springer. pp. 168–182. doi:10.1007/978-3-540-92995-6_12. ISBN978-3-540-92995-6.
"Our type system has been implemented as a part of the LogicBlox development environment."