Susumu Hayashi. Singleton, Union and Intersection Types for Program Extraction. In Takayasu Ito, Albert R. Meyer, editors, Theoretical Aspects of Computer Software, International Conference TACS 91, Sendai, Japan, September 24-27, 1991, Proceedings. Volume 526 of Lecture Notes in Computer Science, pages 701-730, Springer, 1991.
Abstract is missing.