G. Bergman. (2016)cite arxiv:1602.00034Comment: Comments: 50 pages. Main change from version 2: Lemma 26 strengthened to include contractibility statement which in previous version was noted as "likely" in paragraph following that result. Several small typoes also corrected.
B. Ganter, and S. Kuznetsov. Conceptual Structures: Theory, Tools and Applications, volume 1453 of Lecture Notes in Computer Science, Springer, Berlin/Heidelberg, (1998)
S. Kuznetsov, S. Obiedkov, and C. Roth. Proceedings of the 15th International Conference on Conceptual Structures (ICCS 2007), volume 4604 of Lecture Notes in Artificial Intelligence, page 241-254. Berlin, Heidelberg, Springer-Verlag, (July 2007)
B. Ganter, and S. Rudolph. Proceedings of the 9th International Conference on Conceptual Structures (ICCS 2001), volume 2120 of Lecture Notes in Computer Science, page 143-156. Springer, (2001)