An augmentation of semantic networks is presented in which the various nodes and arcs are partitioned into "net spaces." These net spaces delimit the scopes of quantified variables, distinguish hypothetical and imaginary situations from reality, encode alternative worlds considered in planning, and focus attention at particular levels of detail.
A. Popescu, O. Etzioni, and H. Kautz. IUI '03: Proceedings of the 8th international conference on Intelligent user interfaces, page 149--157. New York, NY, USA, ACM, (2003)
R. Gaizauskas, H. Harkema, M. Hepple, and A. Setzer. Temporal Representation and Reasoning, 2006. TIME 2006. Thirteenth International Symposium on, page 188-195. (June 2006)
M. Fuller, E. Mackie, R. Sacks-Davis, and R. Wilkinson. Proceedings of the 16th Annual International ACM SIGIR Conference on Research and Development in Information Retrieval, page 204-213. ACM Press, (1993)
M. Hu, and B. Liu. KDD '04: Proceedings of the tenth ACM SIGKDD international conference on Knowledge discovery and data mining, page 168--177. New York, NY, USA, ACM, (2004)