Containers: Constructing strictly positive types.

Michael Abbott Thorsten Altenkirch Neil Ghani Containers: Constructing strictly positive types. 3-27 2005 342 Theor. Comput. Sci. 1 http://dx.doi.org/10.1016/j.tcs.2005.06.002 db/journals/tcs/tcs342.html#AbbottAG05