Joseph M. Morris. Augmenting Types with Unbounded Demonic and Angelic Nondeterminacy. In Dexter Kozen, Carron Shankland, editors, Mathematics of Program Construction, 7th International Conference, MPC 2004, Stirling, Scotland, UK, July 12-14, 2004, Proceedings. Volume 3125 of Lecture Notes in Computer Science, pages 274-288, Springer, 2004. [doi]