Abstract :
This paper presents a formulation within the framework of data types as initial algebras, of parameterizations of data types. We will observe that Scott´s data type constructors like +, ×, and circular definitions are parameterizations in our sense. Thence we will provide a uniform ground to compare ADJ-like data types with Lehmann-Smyth´s data types, and will justify recent ADJ´s claim that polynomial data types of Lehmann-Smyth could be simulated within ADJery.
