10 Xavier Leroy. 11 Robin Milner, Mads Tofte, and Robert Harper. The definition of Standard ML . The MIT Press, 1990. 12 John C. Mitchell and Gordon D. Plotkin.
Abstract types have existential types.
13 John Ophel, Gordon Cormack, and Dominic Duggan. 14 Didier Remy. In Proceedings of the 16th ACM Conference on Principles of Programming Languages , 1989. 15 Didier Remy. Efficient representation of extensible records.